97 results on '"Lubbe, S"'
Search Results
2. Extraction and Separation of Zirconium Using 1-Octanol
- Author
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Kabangu, M. J., Lubbe, S. J., and Crouse, P. L.
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- 2020
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3. A Combined Study of Headspace Volatiles using Human Sensory, Mass Spectrometry and Chemometrics
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McAdam, K. G., Tetteh, J., Bishop, L., Digard, H., Cote, J., Lubbe, S., and Liu, C.
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- 2020
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4. GPAbin: unifying visualizations of multiple imputations for missing values.
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Nienkemper-Swanepoel, J., le Roux, N. J., and Gardner-Lubbe, S.
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MULTIPLE imputation (Statistics) ,MISSING data (Statistics) ,VISUALIZATION ,INFERENTIAL statistics ,SCATTER diagrams - Abstract
Multiple imputation is a well-established technique for analyzing missing data. Multiple imputed data sets are obtained and analyzed separately using standard complete data techniques. The estimates from the separate analyses are then combined for the purpose of statistical inference. However, the exploratory analysis options of multiple imputed data sets are limited. Biplots are regarded as generalized scatterplots which provide a simultaneous configuration of both samples and variables. A visualization for each of the multiple imputed data sets can be constructed and interpreted individually, but this can become cumbersome and several plots make a unified interpretation challenging. Analogous to multiple imputation, the coordinates of the visualizations can now be regarded as the estimates which are to be pooled in an unbiased manner to construct a final visualization. We propose a GPAbin biplot for a final single visualization after multiple imputation. In a first step, generalized orthogonal Procrustes analysis is used to align the individual biplots before combining their separate coordinate sets into an average coordinate matrix. Finally, this average coordinate matrix is then utilized to construct a single biplot called a GPAbin biplot. A simulation study is used to establish the properties of the final combined GPAbin biplot for varying data characteristics. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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5. Multivariate data analysis identifies natural clusters of tuberous sclerosis complex associated neuropsychiatric disorders (TAND)
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Leclezio, L., Gardner-Lubbe, S., Krueger, D., Jansen, A., Sahin, M., Sparagana, S., De Waele, L., and De Vries, P.
- Published
- 2017
6. Sirkoon as voerstof vir sirkoniumgebaseerde chemikalieë, keramieke, die metaal en sy legerings: 'n Oorsigartikel.
- Author
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Lubbe, S. J. and Crouse, P. L.
- Abstract
South Africa is the second largest producer of zircon internationally. Local beneficiation of the mineral is minimal at present, despite the very attractive market opportunity zirconium-based products present. Several well-developed processes for the production of a range of zirconium chemicals exist. These chemicals can in their turn be used to prepare monoclinic and stabilised zirconium oxides. In the majority of cases zirconium oxychloride octahydrate - generally referred to as ZOC - is used as precursor. Zirconium-based products are generally inert and non-toxic, and may be used in several applications. These include medical implants, anti-perspirants, and even as ammonia absorbents during blood dialysis. Zirconium oxide ceramics also have many applications in medical and industrial applications due to their hardness, chemical inertness and corrosion resistance. This review provides an overview of the processing and synthesis routes between the mineral and these final products, as well as the gateway products. The local context is emphasised. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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7. The 14q22.2 colorectal cancer variant rs4444235 shows cis-acting regulation of BMP4
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Lubbe, S J, Pittman, A M, Olver, B, Lloyd, A, Vijayakrishnan, J, Naranjo, S, Dobbins, S, Broderick, P, Gómez-Skarmeta, J L, and Houlston, R S
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- 2012
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8. Parkinsonʼs disease in GTP cyclohydrolase-1 mutation carriers: 156
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Mencacci, N. E., Isaias, I. U., Reich, M. M., Ganos, C., Plagnol, V., Polke, J. M., Bras, J., Stamelou, M., Noyce, A. J., Opladen, T., Münchau, A., Hodecker, S., Volkmann, J., Lees, A., Alegria, P., Lesage, S., Cormier, F., Brice, A., Heutink, P., Gasser, T., Pittman, A., Lubbe, S., Morris, H. R., Singleton, A., Hardy, J., Klebe, S., Bhatia, K. P., and Wood, N. W.
- Published
- 2014
9. STUDENT LEADERSHIP TRAINING AS A STRESS REDUCTION STRATEGY AT A SOUTH AFRICAN UNIVERSITY.
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Mulenga, C. N., Brouze, K., and Gardner-Lubbe, S.
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STUDENT leadership ,STRESS management ,UNIVERSITIES & colleges ,STUDENT engagement ,ACADEMIC achievement - Abstract
Student leadership at universities are an integral part of both leadership and skills development for the students. The appointment of student leaders in different roles such as tutors, residence assistants and other research assistant roles have become a standard feature of student engagement with universities. The objective of this study was to examine the relationship between role overload, role stress and role satisfaction and investigates whether training has an effect on role satisfaction for residence student leaders at a South African university. The appointment of residence assistance has generated a lot of interest due to the emotional and physical demands of this role. A descriptive design using a cross-sectional survey was administered to the total population of student leaders at a local university, 101 males and 82 females responded to the survey. The gender composition was 30.4 per cent males, 22.8 per cent female and 46.7 were mixed gender residences. Findings showed that role overload and role stress were negatively correlated to role satisfaction; whereas training was perceived positively in relation to role satisfaction. These results emphasize the importance of maintaining acceptable levels of role stress and role satisfaction and reinforced previous findings that reported training as a means to achieving role satisfaction for student leaders. This study showed that providing satisfactory training was effective in increasing skills and reducing role overload and role stress and increasing role satisfaction for the student leaders. [ABSTRACT FROM AUTHOR]
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- 2016
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10. Detection and Quantification of Grapevine Bunch Rot Using Functional Data Analysis and Canonical Variate Analysis Biplots of Infrared Spectral Data.
- Author
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Cornelissen, R. J., Le Roux, N.J., Gardner-Lubbe, S., Aleixandre Tudo, J. L., and Nieuwoudt, H. H.
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FUNCTIONAL analysis , *ATTENUATED total reflectance , *DATA analysis , *GRAPES , *DATA mining , *VINEYARDS , *INDUSTRIAL clusters - Abstract
Grapevine bunch rot assessment has economic significance to wineries. Industrial working conditions require rapid assessment methods to meet the time constraints typically associated with grape intake at large wineries. Naturally rot-affected and healthy white wine grape bunches were collected over five vintages (2013 to 2016, 2020). Spectral data of 382 grape must samples were acquired using three different, but same-type attenuated total reflection mid-infrared (ATR-MIR) ALPHA spectrometers. The practical industrial problem of wavenumber shifts collected with different spectrometers was overcome by applying functional data analysis (FDA). FDA improved the data quality and boosted data mining efforts in the sample set. Canonical variate analysis (CVA) biplots were employed to visualise the detection and quantification of rot. When adding 90 % alpha-bags to CVA biplots minimal overlap between rot-affected (Yes) and healthy (No) samples was observed. Several bands were observed in the region 1734 cm-1 to 1722 cm-1 which correlated with the separation between rot-affected and healthy grape musts. These bands connect to the C=O stretching of the functional groups of carboxylic acids. In addition, wavenumber 1041 cm-1, presenting the functional group of ethanol, contributed to the separation between categories (severity % range). ATR-MIR could provide a sustainable alternative for rapid and automated rot assessment. However, qualitative severity quantification of rot was limited to only discriminating between healthy and severe rot (> 40 %). This study is novel in applying FDA to correct wavenumber shifts in ATR-MIR spectral data. Furthermore, visualisation of the viticultural data set using CVA biplots is a novel application of this technique. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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11. Clinical educators' self-reported personal and professional development after completing a short course in undergraduate clinical supervision at Stellenbosch University.
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Schmutz, A. M. S., Gardner-Lubbe, S., and Archer, E.
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CLINICAL supervision , *UNDERGRADUATES , *CLINICAL competence , *CAREER development , *MEDICAL teaching personnel , *MEDICAL education - Abstract
Background. In 2007, a Supervision Course in Undergraduate Clinical Supervision was developed at the Faculty of Medicine and Health Sciences at Stellenbosch University in South Africa. The target group was inter-professional clinical educators that are involved in student education on the clinical platform. Although the course participants were professionals and specialists in their own fields, the majority of clinical educators have very little or no knowledge of adult education. The Supervision Course aims to develop clinical supervision skills of clinical educators by exposing these supervisors to basic principles of education and specifically clinical teaching, resulting in quality education for undergraduate students. The aim of this study was to determine the impact of this short course on the personal and professional growth of the clinical educator. Methods. A qualitative study was performed, including an open-ended questionnaire that provided opportunity for the clinical educators to elaborate freely on their strengths, weaknesses and areas of desired improvement before and after the Supervision Course, and a semi-structured individual interview after the Supervision Course. The questionnaire data were categorised according to strengths, weaknesses and areas of desired improvement. An inductive approach was used to analyse the qualitative data. Key themes that emerged from the interviews were identified and grouped together in categories. Results. The results are summarised in table format to identify themes with supporting quotes. Conclusion. Although a small sample, this study demonstrates the personal and professional growth reported by attendees of a clinical supervision short course. [ABSTRACT FROM AUTHOR]
- Published
- 2013
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12. A large-scale meta-analysis to refine colorectal cancer risk estimates associated with MUTYH variants.
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Theodoratou, E., Campbell, H., Tenesa, A., Houlston, R., Webb, E., Lubbe, S., Broderick, P., Gallinger, S., Croitoru, E. M., Jenkins, M. A., Win, A. K., Cleary, S. P., Koessler, T., Pharoah, P. D., Küry, S., Bézieau, S., Buecher, B., Ellis, N. A., Peterlongo, P., and Offit, K.
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COLON cancer ,META-analysis ,DNA repair ,OXIDIZING agents ,ADENOMA ,CHI-squared test ,COLON tumors ,DISEASE susceptibility ,HEALTH ,MEDLINE ,GENETIC mutation ,ONLINE information services ,PROBABILITY theory ,RECTUM tumors ,RESEARCH funding ,SYSTEMATIC reviews ,LOGISTIC regression analysis ,BIBLIOGRAPHIC databases ,DATA analysis software - Abstract
Background: defective DNA repair has a causal role in hereditary colorectal cancer (CRC). Defects in the base excision repair gene MUTYH are responsible for MUTYH-associated polyposis and CRC predisposition as an autosomal recessive trait. Numerous reports have suggested MUTYH mono-allelic variants to be low penetrance risk alleles. We report a large collaborative meta-analysis to assess and refine CRC risk estimates associated with bi-allelic and mono-allelic MUTYH variants and investigate age and sex influence on risk.Methods: MUTYH genotype data were included from 20 565 cases and 15 524 controls. Three logistic regression models were tested: a crude model; adjusted for age and sex; adjusted for age, sex and study.Results: all three models produced very similar results. MUTYH bi-allelic carriers demonstrated a 28-fold increase in risk (95% confidence interval (CI): 6.95-115). Significant bi-allelic effects were also observed for G396D and Y179C/G396D compound heterozygotes and a marginal mono-allelic effect for variant Y179C (odds ratio (OR)=1.34; 95% CI: 1.00-1.80). A pooled meta-analysis of all published and unpublished datasets submitted showed bi-allelic effects for MUTYH, G396D and Y179C (OR=10.8, 95% CI: 5.02-23.2; OR=6.47, 95% CI: 2.33-18.0; OR=3.35, 95% CI: 1.14-9.89) and marginal mono-allelic effect for variants MUTYH (OR=1.16, 95% CI: 1.00-1.34) and Y179C alone (OR=1.34, 95% CI: 1.01-1.77).Conclusions: overall, this large study refines estimates of disease risk associated with mono-allelic and bi-allelic MUTYH carriers. [ABSTRACT FROM AUTHOR]- Published
- 2010
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13. The pulp and paper properties of Sirex noctilio infested and fire-damagedthermomechanically pulped, South African grown Pinus patula.
- Author
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du Plessis, M., le Roux, N. J., Gardner-Lubbe, S., Swart, J. P. J., and Rypstra, T.
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SIREX noctilio ,SIREX ,PULPING ,PINUS patula ,PINE - Abstract
Pinus patula is the softwood species most extensively planted in South Africa. However, large portions of these plantings are under threat from Sirex noctilio infestation and occasional forest fires. In this exploratory investigation, the effects of tree age, Sirex noctilio infestation and fire damage to wood from Pinus patula trees on their pulp and paper properties were evaluated. Pulp was produced using the thermomechanical pulping (TMP) process. The energy consumption required to pulp the different pulpwood materials was determined. Pulps were beaten for five different time periods to investigate the development of the fibre properties in response to increasing energy input. Paper properties such as burst, tear strength and breaking length were determined on handsheets manufactured from unbeaten and beaten pulps. Box and line plots and canonical variate analysis biplots were used to statistically analyse the data. It was found that the burst strength of paper produced from healthy trees was significantly higher than that from sirex-infested or fire damaged (burnt) trees. Similarly, the tear strength of paper from healthy and burnt trees was significantly better than from sirex-infested or young trees. No significant differences in breaking length were evident between the pulpwood materials and an increase in beating time did not lead to any improvements. From this study it can be concluded that wood from dead or dying, sirex-infested and young trees produced paper with consistently lower strength properties compared to wood obtained from healthy 12-year-old trees. [ABSTRACT FROM AUTHOR]
- Published
- 2010
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14. Biplot methodology in exploratory analysis of microarray data.
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Gardner-Lubbe, S., le Roux, N. J., Maunders, H., Shah, V., and Patwardhan, S.
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- 2009
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15. Comprehensive analysis of common mitochondrial DNA variants and colorectal cancer risk.
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Webb, E., Broderick, P., Chandler, I., Lubbe, S., Penegar, S., Tomlinson, I. P. M., and Houlston, R. S.
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MITOCHONDRIAL DNA ,COLON cancer risk factors ,TUMOR growth ,ENERGY metabolism ,ETIOLOGY of diseases ,COLON tumors ,COMPARATIVE studies ,DNA ,RESEARCH methodology ,MEDICAL cooperation ,GENETIC mutation ,RECTUM tumors ,RESEARCH ,EVALUATION research ,HAPLOTYPES - Abstract
Several lines of evidence implicate mitochondrial dysfunction in the development of cancer. To test the hypothesis that common mtDNA variation influences the risk of colorectal cancer (CRC), we genotyped 132 tagging mtDNA variants in a sample of 2854 CRC cases and 2822 controls. The variants examined capture approximately 80% of mtDNA common variation (excluding the hypervariable D-loop). We first tested for single marker associations; the strongest association detected was with A5657G (P=0.06). Overall the distribution of association P-values was consistent with a null distribution. Next, we classified individuals into the nine common European haplogroups and compared their distribution in cases and controls. This analysis also provided no evidence of an association between mitochondrial variation and CRC risk. In conclusion, our results provide little evidence that mitochondrial genetic background plays a role in modifying an individual's risk of developing CRC. [ABSTRACT FROM AUTHOR]
- Published
- 2008
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16. The effect of Sirex noctilio infestation and fire damage on the chemical composition of South African-grown Pinus patula pulpwood.
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du Plessis, M., le Roux, N. J., Gardner-Lubbe, S., Swart, J. P. J., and Rypstra, T.
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SIREX noctilio ,XIPHYDRIIDAE ,AMYLOSTEREUM ,TREE mortality ,AGRICULTURAL education - Abstract
The infection and association between the wood wasp Sirex noctilio and the fungus Amylostereum areolatum is responsible for large-scale tree mortality in the Midlands of the KwaZulu-Natal province in South Africa. An exploratory investigation on the effect of the infestation of trees by the wood wasp and its associated fungus on the chemical composition of Pinus patula pulpwood was undertaken. Various tree classes representing different levels of physiological growth stress from this infestation were compared. Together with the above stress agents, fire damage to P. patula trees was also considered as a possible cause of changes in pulpwood chemical composition. Chemical analyses to determine the Seifert cellulose and Klason lignin contents as well as the levels of water- and solvent-soluble extractives were conducted using published Tappi standard methods. The results indicated only negligible differences between infestation levels (tree classes) with respect to Seifert cellulose and Klason lignin contents. In contrast, highly significant differences were observed for solvent- and water-borne extractives. It is evident from the results that P. patula trees engage a defence strategy to counter the effects of the infestation and the resulting physiological stress. The results of the chemical analyses suggest that trees should not be harvested any younger than the intended rotation age of 12 years and at the time of harvesting all the biomass, including the infected wood, should be sent to the pulp mill. Fire-damaged trees can be utilised in the same way as healthy trees when applying the TMP process provided the charcoal on the outer bark is removed. The usefulness of a biplot to simultaneously display the various tree classes and their chemical composition is illustrated. [ABSTRACT FROM AUTHOR]
- Published
- 2008
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17. National study of colorectal cancer genetics.
- Author
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Penegar, S., Wood, W., Lubbe, S., Chandler, I., Broderick, P., Papaemmanuil, E., Sellick, G., Gray, R., Peto, J., and Houlston, R.
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COLON cancer ,CANCER genetics ,CANCER risk factors ,DNA data banks ,TISSUE banks ,DIAGNOSIS of hereditary nonpolyposis colorectal cancer ,ADENOCARCINOMA ,RESEARCH ,RESEARCH methodology ,GENETIC polymorphisms ,MEDICAL cooperation ,HEREDITARY nonpolyposis colorectal cancer ,EVALUATION research ,COLORECTAL cancer ,SPOUSES ,COMPARATIVE studies ,PHENOTYPES - Abstract
Approximately, a third of all colorectal cancer (CRC) is due to inherited susceptibility. However, high-risk mutations in APC, the mismatch repair (MMR) genes, MUTYH/MYH, SMAD4, ALK3 and STK11/LKB1 are rare and account for <5% of cases. Much of the remaining variation in genetic risk is likely to be explained by combinations of more common gene variants that modestly increase risk. Reliable identification of such 'low penetrance' alleles would provide insight into the aetiology of CRC and might highlight potential therapeutic and preventative interventions. In 2003, the National Study of Colorectal Cancer Genetics (NSCCG) was established with the aim of collecting DNA and clinicopathological data from 20,000 CRC cases and a series of spouse/partner controls, thereby creating a unique resource for identifying low-penetrance CRC susceptibility alleles. The National Cancer Research Network (NCRN) adopted NSCCG onto its portfolio of trials and 148 centres in the United Kingdom (UK) are now actively participating. Over 8,700 cases and 2,185 controls have so far been entered into NSCCG. Our experience in developing NSCCG serves to illustrate how world-class DNA databases for genetic analyses can be rapidly developed in the United Kingdom. [ABSTRACT FROM AUTHOR]
- Published
- 2007
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18. On subset multiple correspondence analysis for incomplete multivariate categorical data.
- Author
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Nienkemper-Swanepoel, J., le Roux, N. J., and Gardner-Lubbe, S.
- Abstract
Abstract Multiple imputation is considered as a superior data analysis practice to deal with missing values. This is, in particular, also true in the important case of categorical variables. However, imputation techniques could be a daunting task for the less technical data practitioner. In the case of categorical variables, imputation can be avoided by recoding the indicator matrix of the data set before analysis. New category levels are created for each variable to which missing values are assigned. The recoded indicator matrix enables the separation of missing and observed responses. Subset multiple correspondence analysis (sMCA) allows a focused analysis on either of the missing or non-missing subsets of the recoded indicator matrix while preserving the original variation of the data. The main purpose of this article is to evaluate the sMCA approach using simulated data which incorporate various parameters. In addition, the visualization of multivariate categorical data containing missing values that follows from the sMCA approach is presented. This article could aid as a guide when deciding whether the sMCA approach is suitable for the analysis of incomplete multivariate categorical data. To ensure effortless application of the presented methodology, a complete
R script with commented functions is available as supplementary material. [ABSTRACT FROM AUTHOR]- Published
- 2023
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19. Microsatellite instability indicative of defects in the major mismatch repair genes is rare in patients with B-cell chronic lymphocytic leukemia: Evaluation with disease stage and family history.
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Sellick, G. S., Lubbe, S. J., Matutes, E., Catovsky, D., and Houlston, R. S.
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CHRONIC lymphocytic leukemia , *LYMPHATIC diseases , *LYMPHOPROLIFERATIVE disorders , *CELL proliferation , *DNA - Abstract
A possible role for DNA mismatch repair defects and microsatellite instability (MSI) in the pathogenesis of a number of B-cell lymphoproliferative disorders has recently been debated. To gain further insight into the impact of MSI on B-CLL, we evaluated samples from a series of 982 patients using the mono-satellite markers BAT25 and BAT26, which are highly sensitive in demonstrating classical mismatch repair (MMR) deficiency. Only 1% of cases displayed MSI and this was not correlated with stage of disease or family history of B-CLL. A sub-polymorphic germline variant of BAT25 was identified in one familial case, which was also detected in the patient's affected brother. In conclusion, our study demonstrates that MSI does not have a prominent role in the pathogenesis of B-CLL. [ABSTRACT FROM AUTHOR]
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- 2007
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20. Preliminaries into problems to access information -- the digital divide and rural communities.
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Sikhakhane, B. and Lubbe, S.
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DIGITAL divide , *INFORMATION resources , *INFORMATION technology , *VILLAGES , *INFORMATION society , *ECONOMIC development - Abstract
The article focuses on issues related to the digital divide. The digital divide is the gap that exists between individuals who have reasonable opportunities for accessing technology tools and those who lack such opportunities. The digital divide breaks along many fault lines such as education, income, ethnicity, geography, infrastructure and disability. In urban communities, people have easier access to information resources. However, people living in rural areas have no access due to a scarcity of resources. Houses are scattered and it is not easy to have a center where people can access information. People living in rural areas also lack the skills as well as trainers to assist them in the use of these resources. It is understood that, for a nation to develop, the literacy level must be raised to bridge the digital divide. People in developing countries have less literate as compared to those in developed countries. People in developing countries are not concerned about information as they cannot use it and, as a result, they fall behind.
- Published
- 2005
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21. SeqVerify: An accessible analysis tool for cell line genomic integrity, contamination, and gene editing outcomes.
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Pierson Smela M, Pepe V, Lubbe S, Kiskinis E, and Church GM
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- Humans, Cell Line, Genomics methods, Whole Genome Sequencing methods, High-Throughput Nucleotide Sequencing methods, Animals, Pluripotent Stem Cells metabolism, Pluripotent Stem Cells cytology, Computational Biology methods, CRISPR-Cas Systems, Gene Editing methods, Software
- Abstract
Over the last decade, advances in genome editing and pluripotent stem cell (PSC) culture have let researchers generate edited PSC lines to study a wide variety of biological questions. However, abnormalities in cell lines such as aneuploidy, mutations, on-target and off-target editing errors, and microbial contamination can arise during PSC culture or due to undesired editing outcomes. The ongoing decline of next-generation sequencing prices has made whole-genome sequencing (WGS) a promising option for detecting these abnormalities. However, this approach has been held back by a lack of easily usable data analysis software. Here, we present SeqVerify, a computational pipeline designed to take raw WGS data and a list of intended genome edits, and verify that the edits are present and that there are no abnormalities. We anticipate that SeqVerify will be a useful tool for researchers generating edited PSCs, and more broadly, for cell line quality control in general., Competing Interests: Declaration of interests G.M.C.’s competing interests are listed at: https://arep.med.harvard.edu/gmc/tech.html., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)
- Published
- 2024
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22. The Pathways to Community Living Initiative (PCLI) for older adults: implementation and outcomes.
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Kellett R, Findlay L, Lubbe S, and Wand AP
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- Humans, Aged, Retrospective Studies, Female, Male, Aged, 80 and over, Mental Health Services organization & administration, Mental Disorders therapy, Homes for the Aged organization & administration, Independent Living
- Abstract
Objective: To describe implementation of the Pathways to Community Living Initiative (PCLI) within an Older People's Mental Health (OPMH) service., Method: A retrospective observational study was conducted. Implementation comprised partnership with a specialist Residential Aged Care Facility (RACF). Data were obtained from Clinical Advisory Committee (CAC) discussion and minutes, the PCLI database, and consumer medical records., Results: Eighteen consumers were accepted onto the program between April 2019 and March 2023. Their PCLI and rating scale outcomes alongside interventions facilitating placements are described. Interventions included OPMH case management, wide-reaching liaison, and inservices. Challenges included communication, confusion regarding roles, and differing views on capacity to accommodate complex consumers. Solutions included streamlining communication, including clinical updates in the CAC, facility appointment of a lead PCLI-nurse, and targeted RACF education., Conclusions: Considered interventions strengthened the OPMH and specialist RACF partnership over time. Clarification of professional roles and intersection with other services was crucial. Successful placement for PCLI consumers required consideration of personalised needs and existing resident mix, liaison with stakeholders, and targeted staff training. These strategies may apply to other health services implementing similar initiatives supporting community placements for OPMH consumers with complex needs., Competing Interests: DisclosureThe author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: The four authors receive a part- or full-time salary for their PCLI roles, remitted by the Sydney Local Health District. There are no limitations on their clinical research or reporting. The authors received no financial or non-financial benefits from the research.
- Published
- 2024
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23. The nasopharyngeal microbiome in South African children with lower respiratory tract infection: a nested case-control study of the Drakenstein Child Health Study.
- Author
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Claassen-Weitz S, Xia Y, Workman L, Hannan L, Gardner-Lubbe S, Mwaikono KS, Mounaud SH, Nierman WC, Africa S, Patel F, Dube FS, Allen V, Edries LAT, Zar HJ, and Nicol MP
- Abstract
Background: Lower respiratory tract infection (LRTI) is a leading cause of infant morbidity and mortality globally. LRTI may be caused by viral or bacterial infections, individually or in combination. We investigated associations between LRTI and infant nasopharyngeal (NP) viruses and bacteria in a South African birth cohort., Methods: In a case-control study of infants enrolled in the Drakenstein Child Health Study (DCHS), LRTI cases were identified prospectively and age-matched with controls from the cohort. NP swabs were tested using quantitative real-time polymerase chain reaction (qPCR) and 16S rRNA gene amplicon sequencing. We calculated adjusted Conditional Odds Ratios (aORs) for qPCR targets and used mixed effects models to identify differentially abundant taxa between LRTI cases and controls and explore viral-bacterial interactions., Results: Respiratory Syncytial Virus (RSV) [aOR: 5.69, 95% CI: 3.03-10.69], human rhinovirus (HRV) [1.47, 1.03-2.09], parainfluenza virus [3.46, 1.64-7.26], adenovirus [1.99, 1.08-3.68], enterovirus [2.32, 1.20-4.46], Haemophilus influenzae [1.72, 1.25-2.37], Klebsiella pneumoniae [2.66, 1.59-4.46], or high-density (> 6.9 log
10 copies/mL) Streptococcus pneumoniae [1.53, 1.01-2.32] were associated with LRTI. Using 16S sequencing, LRTI was associated with increased relative abundance of Haemophilus (q = 0.0003) and decreased relative abundance of Dolosigranulum (q = 0.001), Corynebacterium (q = 0.091) and Neisseria (q = 0.004). In samples positive for RSV, Staphylococcus and Alloprevotella were present at lower relative abundance in cases than controls. In samples positive for parainfluenza virus or HRV, Haemophilus was present at higher relative abundance in cases., Conclusions: The associations between bacterial taxa and LRTI are strikingly similar to those identified in high-income countries, suggesting a conserved phenotype. RSV was the major virus associated with LRTI. H. influenzae appears to be the major bacterial driver of LRTI, acting synergistically with viruses. The Gram-positive bacteria Dolosigranulum and Corynebacteria may protect against LRTI, while Staphylococcus was associated with reduced risk of RSV-related LRTI., Funding: National Institutes of Health of the USA, Bill and Melinda Gates Foundation, National Research Foundation South Africa, South African Medical Research Council, L'Oréal-UNESCO For Women in Science South Africa, Australian National Health and Medical Research Council., Competing Interests: Competing interests The authors declare that they have no competing interests.- Published
- 2024
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24. Alterations in Blood Methylome as Potential Epigenetic Biomarker in Sporadic Parkinson's Disease.
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Gonzalez-Latapi P, Bustos B, Dong S, Lubbe S, Simuni T, and Krainc D
- Subjects
- Humans, Male, Female, Aged, Middle Aged, Epigenome genetics, CpG Islands genetics, Parkinson Disease genetics, Parkinson Disease blood, DNA Methylation genetics, Biomarkers blood, Epigenesis, Genetic genetics
- Abstract
Objective: To characterize DNA methylation (DNAm) differences between sporadic Parkinson's disease (PD) and healthy control (HC) individuals enrolled in the Parkinson's Progression Markers Initiative (PPMI)., Methods: Using whole blood, we characterized longitudinal differences in DNAm between sporadic PD patients (n = 196) and HCs (n = 86) enrolled in PPMI. RNA sequencing (RNAseq) was used to conduct gene expression analyses for genes mapped to differentially methylated cytosine-guanine sites (CpGs)., Results: At the time of patient enrollment, 5,178 CpGs were differentially methylated (2,683 hypermethylated and 2,495 hypomethylated) in PD compared to HC. Of these, 579 CpGs underwent significant methylation changes over 3 years. Several differentially methylated CpGs were found near the cytochrome P450 family 2 subfamily E member 1 (CYP2E1) gene. Additionally, multiple hypermethylated CpGs were associated with the N-myc downregulated gene family member 4 (NDRG4) gene. RNA-Seq analyses showed 75 differentially expressed genes in PD patients compared to controls. An integrative analysis of both differentially methylated sites and differentially expressed genes revealed 20 genes that exhibited hypomethylation concomitant with overexpression. Additionally, 1 gene, cathepsin H (CTSH), displayed hypermethylation that was associated with its decreased expression., Interpretation: We provide initial evidence of alterations in DNAm in blood of PD patients that may serve as potential epigenetic biomarker of disease. To evaluate the significance of these changes throughout the progression of PD, additional profiling at longer intervals and during the prodromal stages of disease will be necessary. ANN NEUROL 2024;95:1162-1172., (© 2024 The Authors. Annals of Neurology published by Wiley Periodicals LLC on behalf of American Neurological Association.)
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- 2024
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25. Pathways to community living in practice: Local development and adaptation within an older peoples mental health service.
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Findlay L, Kellett R, Lubbe S, and Wand AP
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- Aged, Humans, Homes for the Aged, Retrospective Studies, Mental Health Services
- Abstract
Objective: To describe the local adaptation of the Pathways to Community Living (PCLI) program in an Older Peoples Mental Health (OPMH) service to guide other services., Method: A retrospective observational study was conducted. Data were obtained from service planning meetings and newly developed documents, Clinical Advisory Committee meetings, and OPMH PCLI database., Results: The PCLI program was adapted for the local OPMH service through development of an assessment template, creating a Memorandum of Understanding with a partner Residential Aged Care Facility (RACF) and establishing processes for collaboration and regular review. Between 2019 and March 2023, 20 mental health consumers were referred to the OPMH PCLI program. Their demographic and clinical characteristics are described., Conclusions: Adaptation of the PCLI program for OPMH consumers required consideration of specific older adult needs to develop a bespoke plan for assessment and partnership with the PCLI-funded RACF. The development phase and ongoing processes for review facilitated engagement of key stakeholders across health and RACF sectors, highlighting issues with consumer engagement. Similar models could be used by other health services to implement the PCLI in their local context., Competing Interests: DisclosureThe author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: The four authors receive a part- or full-time salary for their PCLI roles, remitted by Sydney Local Health District. There are no limitations on their clinical research or reporting.
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- 2023
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26. Development and Feasibility of the Self-Report Quantified Tuberous Sclerosis Complex-Associated Neuropsychiatric Disorders Checklist (TAND-SQ).
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Heunis TM, Chambers N, Vanclooster S, Bissell S, Byars AW, Capal JK, Cukier S, Davis PE, de Vries MC, De Waele L, Flinn J, Gardner-Lubbe S, Gipson T, Kingswood JC, Krueger DA, Kumm AJ, Sahin M, Schoeters E, Smith C, Srivastava S, Takei M, van Eeghen AM, Waltereit R, Jansen AC, and de Vries PJ
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- Humans, Self Report, Feasibility Studies, Consensus, Checklist, Tuberous Sclerosis complications
- Abstract
Background: Tuberous sclerosis complex-associated neuropsychiatric disorders (TAND) are often present but underidentified and undertreated in individuals with tuberous sclerosis complex (TSC). The clinician-completed TAND-Lifetime Checklist (TAND-L) was developed to address this identification and treatment gap. Stakeholder engagement identified the need for a TAND Checklist that can (1) be completed by caregivers or individuals with TSC and (2) quantify TAND difficulties. The aim of this study was to develop a self-report quantified TAND Checklist (TAND-SQ) and conduct feasibility and acceptability testing., Methods: This aim was addressed in three phases: (1) development of the TAND-SQ Checklist, (2) feasibility and acceptability testing of the "near-final" TAND-SQ Checklist, and (3) preparation of the final TAND-SQ Checklist. Participants included 23 technical experts from the TAND consortium in all phases and 58 lived experts (caregivers and individuals with TSC) in phase 2. All participants completed a TAND-SQ Checklist and a checklist feedback form., Results: Phase 1 additions to the TAND-SQ, when compared with the TAND-L, included four new items and a quantification rating. Phase 2 showed high ratings for the "near-final" TAND-SQ Checklist on comprehensiveness, clarity, ease of use, and overall acceptability. In phase 3, questions on strengths, strategies, and a TAND Cluster Profile were added., Conclusion: The TAND-SQ Checklist is presented here for use by individuals with TSC and their caregivers. The next steps as part of the TANDem project include internal and external validation of the checklist and linking of TAND Cluster Profiles generated from the checklist to evidence-informed consensus recommendations within a smartphone application., (Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.)
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- 2023
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27. International consensus recommendations for the identification and treatment of tuberous sclerosis complex-associated neuropsychiatric disorders (TAND).
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de Vries PJ, Heunis TM, Vanclooster S, Chambers N, Bissell S, Byars AW, Flinn J, Gipson TT, van Eeghen AM, Waltereit R, Capal JK, Cukier S, Davis PE, Smith C, Kingswood JC, Schoeters E, Srivastava S, Takei M, Gardner-Lubbe S, Kumm AJ, Krueger DA, Sahin M, De Waele L, and Jansen AC
- Subjects
- Humans, Affect, Anxiety, Consensus, Autistic Disorder, Tuberous Sclerosis complications, Tuberous Sclerosis diagnosis, Tuberous Sclerosis therapy
- Abstract
Background: Tuberous sclerosis complex (TSC) is associated with a wide range of physical manifestations for which international clinical recommendations for diagnosis and management have been established. TSC is, however, also associated with a wide range of TSC-Associated Neuropsychiatric Disorders (TAND) that are typically under-identified and under-treated yet associated with a profound burden of disease. The contemporary evidence base for the identification and treatment of TAND is much more limited and, to date, consensus recommendations for the diagnosis and management of TAND have also been limited and non-specific., Methods: The TANDem project was launched with an international, interdisciplinary, and participatory consortium of 24 individuals, including TSC family representatives, from all World Health Organization (WHO) regions but one. One of the aims of the TANDem project was to generate consensus recommendations for the identification and treatment of TAND. At the time of this project, no internationally adopted standard methodology and methodological checklists existed for the generation of clinical practice recommendations. We therefore developed our own systematic procedure for evidence review and consensus-building to generate evidence-informed consensus recommendations of relevance to the global TSC community., Results: At the heart of the consensus recommendations are ten core principles surrounded by cluster-specific recommendations for each of the seven natural TAND clusters identified in the literature (autism-like, dysregulated behavior, eat/sleep, mood/anxiety, neuropsychological, overactive/impulsive, and scholastic) and a set of wraparound psychosocial cluster recommendations. The overarching recommendation is to "screen" for TAND at least annually, to "act" using appropriate next steps for evaluation and treatment, and to "repeat" the process to ensure early identification and early intervention with the most appropriate biological, psychological, and social evidence-informed approaches to support individuals with TSC and their families., Conclusions: The consensus recommendations should provide a systematic framework to approach the identification and treatment of TAND for health, educational, social care teams and families who live with TSC. To ensure global dissemination and implementation of these recommendations, partnerships with the international TSC community will be important. One of these steps will include the generation of a "TAND toolkit" of "what to seek" and "what to do" when difficulties are identified in TAND clusters., (© 2023. BioMed Central Ltd., part of Springer Nature.)
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- 2023
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28. Succession and determinants of the early life nasopharyngeal microbiota in a South African birth cohort.
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Claassen-Weitz S, Gardner-Lubbe S, Xia Y, Mwaikono KS, Mounaud SH, Nierman WC, Workman L, Zar HJ, and Nicol MP
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- Infant, Child, Humans, Infant, Newborn, South Africa, Birth Cohort, RNA, Ribosomal, 16S genetics, Nasopharynx microbiology, Bacteria genetics, Moraxella genetics, Corynebacterium genetics, Anti-Bacterial Agents therapeutic use, Microbiota genetics, HIV Infections drug therapy
- Abstract
Background: Bacteria colonizing the nasopharynx play a key role as gatekeepers of respiratory health. Yet, dynamics of early life nasopharyngeal (NP) bacterial profiles remain understudied in low- and middle-income countries (LMICs), where children have a high prevalence of risk factors for lower respiratory tract infection. We investigated longitudinal changes in NP bacterial profiles, and associated exposures, among healthy infants from low-income households in South Africa., Methods: We used short fragment (V4 region) 16S rRNA gene amplicon sequencing to characterize NP bacterial profiles from 103 infants in a South African birth cohort, at monthly intervals from birth through the first 12 months of life and six monthly thereafter until 30 months., Results: Corynebacterium and Staphylococcus were dominant colonizers at 1 month of life; however, these were rapidly replaced by Moraxella- or Haemophilus-dominated profiles by 4 months. This succession was almost universal and largely independent of a broad range of exposures. Warm weather (summer), lower gestational age, maternal smoking, no day-care attendance, antibiotic exposure, or low height-for-age z score at 12 months were associated with higher alpha and beta diversity. Summer was also associated with higher relative abundances of Staphylococcus, Streptococcus, Neisseria, or anaerobic gram-negative bacteria, whilst spring and winter were associated with higher relative abundances of Haemophilus or Corynebacterium, respectively. Maternal smoking was associated with higher relative abundances of Porphyromonas. Antibiotic therapy (or isoniazid prophylaxis for tuberculosis) was associated with higher relative abundance of anerobic taxa (Porphyromonas, Fusobacterium, and Prevotella) and with lower relative abundances of health associated-taxa Corynebacterium and Dolosigranulum. HIV-exposure was associated with higher relative abundances of Klebsiella or Veillonella and lower relative abundances of an unclassified genus within the family Lachnospiraceae., Conclusions: In this intensively sampled cohort, there was rapid and predictable replacement of early profiles dominated by health-associated Corynebacterium and Dolosigranulum with those dominated by Moraxella and Haemophilus, independent of exposures. Season and antibiotic exposure were key determinants of NP bacterial profiles. Understudied but highly prevalent exposures prevalent in LMICs, including maternal smoking and HIV-exposure, were associated with NP bacterial profiles. Video Abstract., (© 2023. The Author(s).)
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- 2023
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29. Sputum bacterial load and bacterial composition correlate with lung function and are altered by long-term azithromycin treatment in children with HIV-associated chronic lung disease.
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Abotsi RE, Dube FS, Rehman AM, Claassen-Weitz S, Xia Y, Simms V, Mwaikono KS, Gardner-Lubbe S, McHugh G, Ngwira LG, Kwambana-Adams B, Heyderman RS, Odland JØ, Ferrand RA, and Nicol MP
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- Adolescent, Humans, Child, Azithromycin therapeutic use, Anti-Bacterial Agents therapeutic use, Sputum microbiology, Bacterial Load, RNA, Ribosomal, 16S genetics, Bacteria genetics, Haemophilus, Moraxella, Lung microbiology, Lung Diseases drug therapy, HIV Infections complications, HIV Infections drug therapy
- Abstract
Background: Long-term azithromycin (AZM) treatment reduces the frequency of acute respiratory exacerbation in children and adolescents with HIV-associated chronic lung disease (HCLD). However, the impact of this treatment on the respiratory bacteriome is unknown., Method: African children with HCLD (defined as forced expiratory volume in 1 s z-score (FEV1z) less than - 1.0 with no reversibility) were enrolled in a placebo-controlled trial of once-weekly AZM given for 48-weeks (BREATHE trial). Sputum samples were collected at baseline, 48 weeks (end of treatment) and 72 weeks (6 months post-intervention in participants who reached this timepoint before trial conclusion). Sputum bacterial load and bacteriome profiles were determined using 16S rRNA gene qPCR and V4 region amplicon sequencing, respectively. The primary outcomes were within-participant and within-arm (AZM vs placebo) changes in the sputum bacteriome measured across baseline, 48 weeks and 72 weeks. Associations between clinical or socio-demographic factors and bacteriome profiles were also assessed using linear regression., Results: In total, 347 participants (median age: 15.3 years, interquartile range [12.7-17.7]) were enrolled and randomised to AZM (173) or placebo (174). After 48 weeks, participants in the AZM arm had reduced sputum bacterial load vs placebo arm (16S rRNA copies/µl in log
10 , mean difference and 95% confidence interval [CI] of AZM vs placebo - 0.54 [- 0.71; - 0.36]). Shannon alpha diversity remained stable in the AZM arm but declined in the placebo arm between baseline and 48 weeks (3.03 vs. 2.80, p = 0.04, Wilcoxon paired test). Bacterial community structure changed in the AZM arm at 48 weeks compared with baseline (PERMANOVA test p = 0.003) but resolved at 72 weeks. The relative abundances of genera previously associated with HCLD decreased in the AZM arm at 48 weeks compared with baseline, including Haemophilus (17.9% vs. 25.8%, p < 0.05, ANCOM ω = 32) and Moraxella (1% vs. 1.9%, p < 0.05, ANCOM ω = 47). This reduction was sustained at 72 weeks relative to baseline. Lung function (FEV1z) was negatively associated with bacterial load (coefficient, [CI]: - 0.09 [- 0.16; - 0.02]) and positively associated with Shannon diversity (0.19 [0.12; 0.27]). The relative abundance of Neisseria (coefficient, [standard error]: (2.85, [0.7], q = 0.01), and Haemophilus (- 6.1, [1.2], q < 0.001) were positively and negatively associated with FEV1z, respectively. An increase in the relative abundance of Streptococcus from baseline to 48 weeks was associated with improvement in FEV1z (3.2 [1.11], q = 0.01) whilst an increase in Moraxella was associated with decline in FEV1z (-2.74 [0.74], q = 0.002)., Conclusions: AZM treatment preserved sputum bacterial diversity and reduced the relative abundances of the HCLD-associated genera Haemophilus and Moraxella. These bacteriological effects were associated with improvement in lung function and may account for reduced respiratory exacerbations associated with AZM treatment of children with HCLD. Video Abstract., (© 2023. The Author(s).)- Published
- 2023
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30. Empowering Families Through Technology: A Mobile-Health Project to Reduce the TAND Identification and Treatment Gap (TANDem).
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Heunis TM, Bissell S, Byars AW, Capal JK, Chambers N, Cukier S, Davis PE, De Waele L, Flinn J, Gardner-Lubbe S, Gipson T, Kingswood JC, Krueger DA, Kumm AJ, Sahin M, Schoeters E, Smith C, Srivastava S, Takei M, Vanclooster S, van Eeghen AM, Waltereit R, Jansen AC, and de Vries PJ
- Abstract
Introduction: Tuberous Sclerosis Complex (TSC) is a multi-system genetic disorder with various TSC-Associated Neuropsychiatric Disorders (TAND) that significantly impact the mental health and wellbeing of individuals with TSC and their caregivers. TAND represents the number one concern to families worldwide, yet is highly under-identified and under-treated. The clinician-administered TAND-Checklist (Lifetime version, TAND-L) has improved identification of TAND in clinical settings. However, many individuals with TSC and their caregivers still have difficulty accessing suitable support for diagnosis and evidence-informed interventions. The TANDem study is a community-based participatory research project with a broad range of TSC stakeholders aimed at reducing the TAND identification and treatment gap., Objectives: Participatory research identified three priority next steps: 1) development and validation of a self-report, quantified version of the TAND Checklist (TAND-SQ) and building the TAND-SQ into a smartphone application, 2) generation of consensus clinical recommendations for the identification and treatment of TAND, to be incorporated as a TAND toolkit on the app, and 3) establishment of a global TAND consortium through networking, capacity-building and public engagement activities., Methods: TANDem is a four-year project, and includes 24 consortium members from 10 countries representing all World Health Organization regions. Collaborators represent five stakeholder groups (family representatives, technology experts, clinical experts, non-profit organisations and researchers). Here we outline the project study protocol in detail, describing the scientific rationale, the project aims and objectives, the methods involved in participant recruitment, multi-site and multi-phase data collection, data analysis, ethical considerations including informed consent, data protection, privacy and confidentiality considerations related to the European Union General Data Protection Regulation and the USA Health Insurance Portability and Accountability Act. The expected outcomes and potential impact on the TSC community, implementation and dissemination of results, as well as future scale-up and scale-out plans are also discussed., Conclusions: The TANDem project has the potential to transform the global TSC community by empowering families living with TSC through an easily accessible digital solution to allow them to document their own TAND needs linked to an evidence-informed toolkit to enhance personalised healthcare, and by providing healthcare professionals with consensus clinical recommendations to prevent, identify and manage TAND manifestations., Competing Interests: SB is funded by Cerebra to investigate sleep and behaviour in rare genetic syndromes, including TSC. PD receives partial salary support from Aucta Pharmaceuticals for a study of topical sirolimus for facial angiofibromas in TSC and Marinus Pharmaceuticals for a study of ganaxolone for TSC-related epilepsy. ACJ was on the scientific advisory group of the TOSCA international disease registry sponsored by Novartis. DK reports personal fees from Novartis Pharmaceuticals, personal fees from Greenwich Bioscience, grants from Marinus Pharmaceuticals, personal fees from Nobelpharma America, and personal fees from REGENXBIO outside the submitted work. MS reports grant support from Novartis, Biogen, Astellas, Aeovian, Bridgebio, and Aucta; and has served on Scientific Advisory Boards for Novartis, Roche, Regenxbio, SpringWorks Therapeutics, Jaguar Therapeutics, and Alkermes. CS receives salary support from GW Pharma, Mallinckrodt, Nobelpharma, Novartis, Ovid, UCB, and Upsher-Smith. PJdV was a study steering committee member of three phase III trials sponsored by Novartis and on the scientific advisory group of the TOSCA international disease registry sponsored by Novartis. AMvE reports a grant from GW Pharmaceuticals for TAND-related research during the conduct of the study. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The handling editor declared a shared affiliation, though no other collaboration, with one of the authors SB at the time of review., (Copyright © 2022 Heunis, Bissell, Byars, Capal, Chambers, Cukier, Davis, De Waele, Flinn, Gardner-Lubbe, Gipson, Kingswood, Krueger, Kumm, Sahin, Schoeters, Smith, Srivastava, Takei, Vanclooster, van Eeghen, Waltereit, Jansen and de Vries.)
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- 2022
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31. The research landscape of tuberous sclerosis complex-associated neuropsychiatric disorders (TAND)-a comprehensive scoping review.
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Vanclooster S, Bissell S, van Eeghen AM, Chambers N, De Waele L, Byars AW, Capal JK, Cukier S, Davis P, Flinn J, Gardner-Lubbe S, Gipson T, Heunis TM, Hook D, Kingswood JC, Krueger DA, Kumm AJ, Sahin M, Schoeters E, Smith C, Srivastava S, Takei M, Waltereit R, Jansen AC, and de Vries PJ
- Subjects
- Adolescent, Aged, Cohort Studies, Humans, Autism Spectrum Disorder, Tuberous Sclerosis complications, Tuberous Sclerosis psychology
- Abstract
Background: Tuberous sclerosis complex (TSC)-associated neuropsychiatric disorders (TAND) is an umbrella term for the behavioural, psychiatric, intellectual, academic, neuropsychological and psychosocial manifestations of TSC. Although TAND affects 90% of individuals with TSC during their lifetime, these manifestations are relatively under-assessed, under-treated and under-researched. We performed a comprehensive scoping review of all TAND research to date (a) to describe the existing TAND research landscape and (b) to identify knowledge gaps to guide future TAND research., Methods: The study was conducted in accordance with stages outlined within the Arksey and O'Malley scoping review framework. Ten research questions relating to study characteristics, research design and research content of TAND levels and clusters were examined., Results: Of the 2841 returned searches, 230 articles published between 1987 and 2020 were included (animal studies = 30, case studies = 47, cohort studies = 153), with more than half published since the term TAND was coined in 2012 (118/230; 51%). Cohort studies largely involved children and/or adolescents (63%) as opposed to older adults (16%). Studies were represented across 341 individual research sites from 45 countries, the majority from the USA (89/341; 26%) and the UK (50/341; 15%). Only 48 research sites (14%) were within low-middle income countries (LMICs). Animal studies and case studies were of relatively high/high quality, but cohort studies showed significant variability. Of the 153 cohort studies, only 16 (10%) included interventions. None of these were non-pharmacological, and only 13 employed remote methodologies (e.g. telephone interviews, online surveys). Of all TAND clusters, the autism spectrum disorder-like cluster was the most widely researched (138/230; 60%) and the scholastic cluster the least (53/200; 27%)., Conclusions: Despite the recent increase in TAND research, studies that represent participants across the lifespan, LMIC research sites and non-pharmacological interventions were identified as future priorities. The quality of cohort studies requires improvement, to which the use of standardised direct behavioural assessments may contribute. In human studies, the academic level in particular warrants further investigation. Remote technologies could help to address many of the TAND knowledge gaps identified., (© 2022. The Author(s).)
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- 2022
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32. Homicide and Dementia: A Systematic Review.
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Sundakov-Krumins TE, Lubbe S, and Wand APF
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- Aged, Homicide psychology, Humans, Retrospective Studies, Risk Factors, Dementia, Psychotic Disorders
- Abstract
Background: Homicide by older offenders is rare and devastating. It likely occurs due to a complex interaction of personal, social, and environmental factors. Dementia is a progressive neurological condition which may amplify behavioural disturbances such as aggression. This systematic review aims to evaluate the factors associated with homicide committed by people with dementia in order to inform clinical practice., Summary: MEDLINE, PsychINFO, Embase, and PubMed databases were searched in accordance with PRISMA guidelines for empirical studies examining the characteristics and circumstances of people with dementia who committed homicides. Data on factors associated with the homicide were extracted and the quality of each study rated using standardized criteria. A total of 499 papers were screened and thirteen studies met the inclusion criteria. Study design included case reports (seven studies), case series (four studies), and two retrospective cohort studies, indicative of low levels of evidence. Sample sizes were 1-70. Study findings were predominantly descriptive. Quality ratings ranged from 50 to 100%. Factors associated with disinhibition such as dysexecutive syndrome, alcohol use, and delirium may predispose to severe impulsive aggression. Psychosis and personality pathology appeared to influence targeted assaults resulting in homicide by people with dementia. Victim vulnerability was also a key element., Key Messages: The current evidence examining risk factors for homicide committed by people with dementia is limited. However, there are common characteristics reported in these descriptive studies including psychiatric factors and cognitive states causing disinhibition. Recommendations for clinical practice include early assessment of older people with dementia and changed behaviours to allow management of comorbidities and reversible risk factors, alongside education, and advice to carers (who may be targets of aggression). Specialized geriatric forensic psychiatry services and care settings should be developed., (© 2022 S. Karger AG, Basel.)
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- 2022
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33. Multivariate data analysis identifies natural clusters of Tuberous Sclerosis Complex Associated Neuropsychiatric Disorders (TAND).
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de Vries PJ, Leclezio L, Gardner-Lubbe S, Krueger D, Sahin M, Sparagana S, De Waele L, and Jansen A
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- Checklist, Cross-Sectional Studies, Data Analysis, Humans, Multivariate Analysis, Tuberous Sclerosis
- Abstract
Background: Tuberous Sclerosis Complex (TSC), a multi-system genetic disorder, is associated with a wide range of TSC-Associated Neuropsychiatric Disorders (TAND). Individuals have apparently unique TAND profiles, challenging diagnosis, psycho-education, and intervention planning. We proposed that identification of natural TAND clusters could lead to personalized identification and treatment of TAND. Two small-scale studies showed cluster and factor analysis could identify clinically meaningful natural TAND clusters. Here we set out to identify definitive natural TAND clusters in a large, international dataset., Method: Cross-sectional, anonymized TAND Checklist data of 453 individuals with TSC were collected from six international sites. Data-driven methods were used to identify natural TAND clusters. Mean squared contingency coefficients were calculated to produce a correlation matrix, and various cluster analyses and exploratory factor analysis were examined. Statistical robustness of clusters was evaluated with 1000-fold bootstrapping, and internal consistency calculated with Cronbach's alpha., Results: Ward's method rendered seven natural TAND clusters with good robustness on bootstrapping. Cluster analysis showed significant convergence with an exploratory factor analysis solution, and, with the exception of one cluster, internal consistency of the emerging clusters was good to excellent. Clusters showed good clinical face validity., Conclusions: Our findings identified a data-driven set of natural TAND clusters from within highly variable TAND Checklist data. The seven natural TAND clusters could be used to train families and professionals and to develop tailored approaches to identification and treatment of TAND. Natural TAND clusters may also have differential aetiological underpinnings and responses to molecular and other treatments., (© 2021. The Author(s).)
- Published
- 2021
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34. Linear discriminant analysis for multiple functional data analysis.
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Gardner-Lubbe S
- Abstract
In multivariate data analysis, Fisher linear discriminant analysis is useful to optimally separate two classes of observations by finding a linear combination of p variables. Functional data analysis deals with the analysis of continuous functions and thus can be seen as a generalisation of multivariate analysis where the dimension of the analysis space p strives to infinity. Several authors propose methods to perform discriminant analysis in this infinite dimensional space. Here, the methodology is introduced to perform discriminant analysis, not on single infinite dimensional functions, but to find a linear combination of p infinite dimensional continuous functions, providing a set of continuous canonical functions which are optimally separated in the canonical space., Competing Interests: No potential conflict of interest was reported by the author(s)., (© 2020 Informa UK Limited, trading as Taylor & Francis Group.)
- Published
- 2020
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35. The Influence of DNA Extraction and Lipid Removal on Human Milk Bacterial Profiles.
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Ojo-Okunola A, Claassen-Weitz S, Mwaikono KS, Gardner-Lubbe S, Zar HJ, Nicol MP, and du Toit E
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Culture-independent molecular techniques have advanced the characterization of environmental and human samples including the human milk (HM) bacteriome. However, extraction of high-quality genomic DNA that is representative of the bacterial population in samples is crucial. Lipids removal from HM prior to DNA extraction is common practice, but this may influence the bacterial population detected. The objective of this study was to compare four commercial DNA extraction kits and lipid removal in relation to HM bacterial profiles. Four commercial DNA extraction kits, QIAamp
® DNA Microbiome Kit, ZR Fungal/Bacterial DNA MiniPrep™, QIAsymphony DSP DNA Kit and ZymoBIOMICS™ DNA Miniprep Kit, were assessed using milk collected from ten healthy lactating women. The kits were evaluated based on their ability to extract high quantities of pure DNA from HM and how well they extracted DNA from bacterial communities present in a commercial mock microbial community standard spiked into HM. Finally, the kits were evaluated by assessing their extraction repeatability. Bacterial profiles were assessed using Illumina MiSeq sequencing targeting the V4 region of the 16S rRNA gene. The ZR Fungal/Bacterial DNA MiniPrep™ and ZymoBIOMICS™ DNA Miniprep (Zymo Research Corp., Irvine, CA, USA) kits extracted the highest DNA yields with the best purity. DNA extracted using ZR Fungal/Bacterial DNA MiniPrep™ best represented the bacteria in the mock community spiked into HM. In un-spiked HM samples, DNA extracted using the QIAsymphony DSP DNA kit showed statistically significant differences in taxa prevalence from DNA extracted using ZR Fungal/Bacterial DNA MiniPrep™ and ZymoBIOMICS™ DNA Miniprep kits. The only difference between skim and whole milk is observed in bacterial profiles with differing relative abundances of Enhydrobacter and Acinetobacter . DNA extraction, but not lipids removal, substantially influences bacterial profiles detected in HM samples, emphasizing the need for careful selection of a DNA extraction kit to improve DNA recovery from a range of bacterial taxa.- Published
- 2020
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36. Optimizing 16S rRNA gene profile analysis from low biomass nasopharyngeal and induced sputum specimens.
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Claassen-Weitz S, Gardner-Lubbe S, Mwaikono KS, du Toit E, Zar HJ, and Nicol MP
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- Bacteria genetics, Bacteria isolation & purification, Biomass, Computer Simulation, DNA, Bacterial genetics, DNA, Ribosomal genetics, Gene Dosage, High-Throughput Nucleotide Sequencing, Humans, Infant, Newborn, Specimen Handling, Bacteria classification, Nasopharynx microbiology, RNA, Ribosomal, 16S genetics, Sequence Analysis, DNA methods, Sputum microbiology
- Abstract
Background: Careful consideration of experimental artefacts is required in order to successfully apply high-throughput 16S ribosomal ribonucleic acid (rRNA) gene sequencing technology. Here we introduce experimental design, quality control and "denoising" approaches for sequencing low biomass specimens., Results: We found that bacterial biomass is a key driver of 16S rRNA gene sequencing profiles generated from bacterial mock communities and that the use of different deoxyribonucleic acid (DNA) extraction methods [DSP Virus/Pathogen Mini Kit® (Kit-QS) and ZymoBIOMICS DNA Miniprep Kit (Kit-ZB)] and storage buffers [PrimeStore® Molecular Transport medium (Primestore) and Skim-milk, Tryptone, Glucose and Glycerol (STGG)] further influence these profiles. Kit-QS better represented hard-to-lyse bacteria from bacterial mock communities compared to Kit-ZB. Primestore storage buffer yielded lower levels of background operational taxonomic units (OTUs) from low biomass bacterial mock community controls compared to STGG. In addition to bacterial mock community controls, we used technical repeats (nasopharyngeal and induced sputum processed in duplicate, triplicate or quadruplicate) to further evaluate the effect of specimen biomass and participant age at specimen collection on resultant sequencing profiles. We observed a positive correlation (r = 0.16) between specimen biomass and participant age at specimen collection: low biomass technical repeats (represented by < 500 16S rRNA gene copies/μl) were primarily collected at < 14 days of age. We found that low biomass technical repeats also produced higher alpha diversities (r = - 0.28); 16S rRNA gene profiles similar to no template controls (Primestore); and reduced sequencing reproducibility. Finally, we show that the use of statistical tools for in silico contaminant identification, as implemented through the decontam package in R, provides better representations of indigenous bacteria following decontamination., Conclusions: We provide insight into experimental design, quality control steps and "denoising" approaches for 16S rRNA gene high-throughput sequencing of low biomass specimens. We highlight the need for careful assessment of DNA extraction methods and storage buffers; sequence quality and reproducibility; and in silico identification of contaminant profiles in order to avoid spurious results.
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- 2020
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37. Association of maternal prenatal psychological stressors and distress with maternal and early infant faecal bacterial profile.
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Naudé PJW, Claassen-Weitz S, Gardner-Lubbe S, Botha G, Kaba M, Zar HJ, Nicol MP, and Stein DJ
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- Adult, Female, Humans, Infant, Infant, Newborn, Male, Pregnancy, Feces microbiology, Mothers psychology, Prenatal Exposure Delayed Effects microbiology, Stress, Psychological microbiology
- Abstract
Objective: Findings from animal studies indicate that the early gut bacteriome is a potential mechanism linking maternal prenatal stress with health trajectories in offspring. However, clinical studies are scarce and the associations of maternal psychological profiles with the early infant faecal bacteriome are unknown. This study aimed to investigate the associations of prenatal stressors and distress with early infant faecal bacterial profiles in a South African birth cohort study., Methods: Associations between prenatal symptoms of depression, distress, intimate partner violence (IPV) and posttraumatic stress disorder (PTSD) and faecal bacterial profiles were evaluated in meconium and subsequent stool specimens from 84 mothers and 101 infants at birth, and longitudinally from a subset of 69 and 36 infants at 4-12 and 20-28 weeks of age, respectively, in a South African birth cohort study., Results: Infants born to mothers that were exposed to high levels of IPV had significantly higher proportions of Citrobacter and three unclassified genera, all of which belonging to the family Enterobacteriaceae detected at birth. Proportions of these Enterobacteriaceae remained significantly increased over time (birth to 20-28 weeks of life) in infants born to mothers with high levels of IPV exposure compared to infants from mothers with no/low IPV exposure. Infants born to mothers exposed to IPV also had higher proportions of the genus Weissella at 4-12 weeks compared to infants from mothers with no/low IPV exposure. Faecal specimens from mothers exposed to IPV had higher proportions of the family Lactobacillaceae and lower proportions of Peptostreptococcaceae at birth. Maternal psychological distress was associated with decreased proportions of the family Veillonellaceae in infants at 20-28 weeks and a slower decline in Gammaproteobacteria over time. No changes in beta diversity were apparent for maternal or infant faecal bacterial profiles in relation to any of the prenatal measures for psychological adversities., Conclusion: Maternal lifetime IPV and antenatal psychological distress are associated with altered bacterial profiles in infant and maternal faecal bacteria. These findings may provide insights in the involvement of the gut bacteria linking maternal psychological adversity and the maturing infant brain.
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- 2020
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38. Influence of Socio-Economic and Psychosocial Profiles on the Human Breast Milk Bacteriome of South African Women.
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Ojo-Okunola A, Claassen-Weitz S, Mwaikono KS, Gardner-Lubbe S, Stein DJ, Zar HJ, Nicol MP, and du Toit E
- Subjects
- Adult, Age Factors, Bacteriological Techniques, Female, Humans, Lactation, RNA, Ribosomal, 16S, South Africa, Bacteria growth & development, Microbiota, Milk, Human microbiology, Mothers statistics & numerical data, Socioeconomic Factors
- Abstract
The human breast milk (HBM) bacteriome is an important, continuous source of microbes to the neonate in early life, playing an important role in shaping the infant's intestinal bacteriome. Study of the composition of the HBM bacteriome is an emerging area of research, with little information available, particularly from low- and middle-income countries. The aim of this study was to characterize the diversity of bacterial communities in HBM samples collected between 6-10 weeks postpartum from lactating South African women and to study potential influencing factors of the bacteriome. Using 16S rRNA gene sequencing of samples from 554 women, we demonstrated that the HBM bacteriome was largely dominated by the phyla Firmicutes (mean relative abundance: 71.1%) and Actinobacteria (mean relative abundance: 16.4%). The most abundant genera identified from the HBM bacteriome were Streptococcus (mean relative abundance: 48.6%), Staphylococcus (mean relative abundance: 17.8%), Rothia (mean relative abundance: 5.8%), and Corynebacterium (mean relative abundance: 4.3%). "Core" bacterial genera including Corynebacterium , Streptococcus, Staphylococcus, Rothia, Veillonella, Gemella, Acinetobacter, Micrococcus and a genus belonging to the Enterobacteriaceae family were present in 80% of samples. HBM samples were classified, according to their bacteriome, into three major clusters, dominated by the genera Staphylococcus (cluster 1), a combination of Staphylococcus and Streptococcus (cluster 2), and Streptococcus (cluster 3). The cluster groups differed significantly for Shannon and chao1 richness indices. Bacterial interactions were studied using co-occurrence networks with positive associations observed between the abundances of Staphylococcus and Corynebacteria (members of the skin microflora) and between Streptococcus, Rothia, Veillonella, and Gemella (members of the oral microflora). HBM from older mothers had a higher Shannon diversity index. The study site was associated with differences in HBM bacteriome composition (permutational multivariate analysis of variance using distance matrices (PERMANOVA), p < 0.05). No other tested socio-demographic or psychosocial factors were associated with HBM bacterial composition., Competing Interests: The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.
- Published
- 2019
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39. Longitudinal Population Dynamics of Staphylococcus aureus in the Nasopharynx During the First Year of Life.
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Abdulgader SM, Robberts L, Ramjith J, Nduru PM, Dube F, Gardner-Lubbe S, Zar HJ, and Nicol MP
- Abstract
Background: Staphylococcus aureus colonization is a risk factor for invasive disease. Few studies have used strain genotype data to study S. aureus acquisition and carriage patterns. We investigated S. aureus nasopharyngeal carriage in infants in an intensively sampled South African birth cohort. Methods: Nasopharyngeal swabs were collected at birth and fortnightly from 137 infants through their first year of life. S. aureus was characterized by spa -typing. The incidence of S. aureus acquisition, and median carriage duration for each genotype was determined. S. aureus carriage patterns were defined by combining the carrier index (proportion of samples testing positive for S. aureus ) with genotype diversity measures. Persistent or prolonged carriage were defined by a carrier index ≥0.8 or ≥0.5, respectively. Risk factors for time to acquisition of S. aureus were determined. Results: Eighty eight percent (121/137) of infants acquired S. aureus at least once. The incidence of acquisition at the species and genotype level was 1.83 and 2.8 episodes per child-year, respectively. No children had persistent carriage (defined as carrier index of >0.8). At the species level 6% had prolonged carriage, while only 2% had prolonged carriage with the same genotype. Carrier index correlated with the absolute number of spa -CCs carried by each infant ( r = 0.5; 95% CI 0.35-0.62). Time to first acquisition of S. aureus was shorter in children from households with ≥5 individuals (HR 1.06, 95% CI 1.07-1.43), with S. aureus carrier mothers (HR; 1.5, 95% CI 1.2-2.47), or with a positive tuberculin skin test during the first year of life (HR; 1.81, 95% CI 0.97-3.3). Conclusion: Using measures of genotype diversity, we showed that S. aureus NP carriage is highly dynamic in infants. Prolonged carriage with a single strain occurred rarely; persistent carriage was not observed. A correlation was observed between carrier index and genotype diversity.
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- 2019
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40. Longitudinal characterization of nasopharyngeal colonization with Streptococcus pneumoniae in a South African birth cohort post 13-valent pneumococcal conjugate vaccine implementation.
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Dube FS, Ramjith J, Gardner-Lubbe S, Nduru P, Robberts FJL, Wolter N, Zar HJ, and Nicol MP
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- Carrier State diagnosis, Carrier State microbiology, Female, Humans, Infant, Longitudinal Studies, Male, Pneumococcal Vaccines immunology, Serogroup, Vaccines, Conjugate immunology, Nasopharynx microbiology, Pneumococcal Vaccines administration & dosage, Streptococcus pneumoniae immunology, Vaccines, Conjugate administration & dosage
- Abstract
Monitoring changes in pneumococcal carriage is key to understanding vaccination-induced shifts in the ecology of carriage and impact on health. We longitudinally investigated pneumococcal carriage dynamics in infants. Pneumococcal isolates were obtained from nasopharyngeal (NP) swabs collected 2-weekly from 137 infants enrolled from birth through their first year of life. Pneumococci were serotyped by sequetyping, confirmed by Quellung. Pneumococci were isolated from 54% (1809/3331) of infants. Median time to first acquisition was 63 days. Serotype-specific acquisition rates ranged from 0.01 to 0.88 events/child-year and did not differ between PCV13 and non-PCV13 serotypes (0.11 events/child-year [95% CI 0.07-0.18] vs. 0.11 events/child-year [95% CI 0.06-0.18]). There was no difference in carriage duration between individual PCV13 and non-PCV13 serotypes (40.6 days [95% CI 31.9-49.4] vs. 38.6 days [95% CI 35.1-42.1]), however cumulatively the duration of carriage of non-PCV13 serotypes was greater than PCV13 serotypes (141.2 days (95% CI 126.6-155.8) vs. 30.7 days (95% CI 22.3-39.0). Frequently carried PCV13 serotypes included 19F, 9V, 19A and 6A, while non-PCV13 serotypes included 15B/15C, 21, 10A, 16F, 35B, 9N and 15A. Despite high immunization coverage in our setting, PCV13 serotypes remain in circulation in this cohort, comprising 22% of isolates. Individual PCV13 serotypes were acquired, on average, at equivalent rate to non-PCV13 serotypes, and carried for a similar duration, although the most common non-PCV13 serotypes were more frequently acquired than PCV13 serotypes.
- Published
- 2018
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41. Coach-directed education is associated with injury-prevention behaviour in players: an ecological cross-sectional study.
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Brown JC, Gardner-Lubbe S, Lambert MI, van Mechelen W, and Verhagen E
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- Adolescent, Adult, Cross-Sectional Studies, Humans, South Africa, Young Adult, Athletes education, Athletic Injuries prevention & control, Football injuries, Mentors
- Abstract
Background/aim: Rugby union ('rugby') presents an above-average risk of injury to participants. BokSmart is a South African nationwide intervention that aims to reduce rugby-related injuries in players. This is achieved by educating coaches and referees to improve injury behaviour of players. Thus, the aim of this study was to assess if the receipt of injury-prevention education was associated with player behaviour., Methods: Junior (n=2279) and senior (n=1642) players, who attended merit-based South African Rugby tournaments (2008-2012), completed an anonymous questionnaire. Logistic regressions investigated if player injury-prevention behaviours were associated with the receipt of education on the same topic. Additionally, players' preferred sources of education were explored through frequency and χ
2 analyses., Results: Of the 16 injury-prevention behaviours, 12 (75%) were associated with receiving education on that topic. The four behaviours not associated with education were: warming-up (before training and matches), and avoiding heat and massage post injury. Of the seven possible sources of this education, the majority of players chose either coaches or physiotherapists as their preferred media. In comparison with junior players, more senior players chose physiotherapists instead of coaches for warming-up and cooling-down education., Conclusions: The results of this study support, to a large degree, the strategy of BokSmart -influence of player behaviour through coach education. However, these findings also suggest that BokSmart could target team physiotherapists in addition to coaches and referees with their safety education. Also, players might have different preferences for this education depending on their age., Competing Interests: Competing interests: None declared., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.)- Published
- 2018
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42. Is It Feasible to Identify Natural Clusters of TSC-Associated Neuropsychiatric Disorders (TAND)?
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Leclezio L, Gardner-Lubbe S, and de Vries PJ
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- Adolescent, Adult, Anxiety Disorders physiopathology, Attention Deficit Disorder with Hyperactivity etiology, Attention Deficit Disorder with Hyperactivity physiopathology, Autism Spectrum Disorder etiology, Autism Spectrum Disorder physiopathology, Behavioral Symptoms physiopathology, Child, Child, Preschool, Cluster Analysis, Cognitive Dysfunction physiopathology, Depressive Disorder physiopathology, Factor Analysis, Statistical, Feasibility Studies, Female, Humans, Intellectual Disability etiology, Intellectual Disability physiopathology, Male, Neurodevelopmental Disorders physiopathology, Pilot Projects, Tuberous Sclerosis physiopathology, Young Adult, Anxiety Disorders etiology, Behavioral Symptoms etiology, Cognitive Dysfunction etiology, Depressive Disorder etiology, Neurodevelopmental Disorders etiology, Tuberous Sclerosis classification, Tuberous Sclerosis complications
- Abstract
Background: Tuberous sclerosis complex (TSC) is a genetic disorder with multisystem involvement. The lifetime prevalence of TSC-Associated Neuropsychiatric Disorders (TAND) is in the region of 90% in an apparently unique, individual pattern. This "uniqueness" poses significant challenges for diagnosis, psycho-education, and intervention planning. To date, no studies have explored whether there may be natural clusters of TAND. The purpose of this feasibility study was (1) to investigate the practicability of identifying natural TAND clusters, and (2) to identify appropriate multivariate data analysis techniques for larger-scale studies., Methods: TAND Checklist data were collected from 56 individuals with a clinical diagnosis of TSC (n = 20 from South Africa; n = 36 from Australia). Using R, the open-source statistical platform, mean squared contingency coefficients were calculated to produce a correlation matrix, and various cluster analyses and exploratory factor analysis were examined., Results: Ward's method rendered six TAND clusters with good face validity and significant convergence with a six-factor exploratory factor analysis solution. The "bottom-up" data-driven strategies identified a "scholastic" cluster of TAND manifestations, an "autism spectrum disorder-like" cluster, a "dysregulated behavior" cluster, a "neuropsychological" cluster, a "hyperactive/impulsive" cluster, and a "mixed/mood" cluster., Conclusions: These feasibility results suggest that a combination of cluster analysis and exploratory factor analysis methods may be able to identify clinically meaningful natural TAND clusters. Findings require replication and expansion in larger dataset, and could include quantification of cluster or factor scores at an individual level., (Copyright © 2018 Elsevier Inc. All rights reserved.)
- Published
- 2018
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43. HIV-exposure, early life feeding practices and delivery mode impacts on faecal bacterial profiles in a South African birth cohort.
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Claassen-Weitz S, Gardner-Lubbe S, Nicol P, Botha G, Mounaud S, Shankar J, Nierman WC, Mulder N, Budree S, Zar HJ, Nicol MP, and Kaba M
- Subjects
- Adult, Bifidobacterium genetics, Bifidobacterium isolation & purification, Breast Feeding, Feces virology, Feeding Behavior, Female, Firmicutes genetics, Firmicutes isolation & purification, HIV genetics, HIV pathogenicity, HIV Infections genetics, HIV Infections virology, Humans, Infant, Infant Formula microbiology, Infant, Newborn, Meconium virology, Mothers, Proteobacteria genetics, Proteobacteria isolation & purification, RNA, Ribosomal, 16S genetics, South Africa epidemiology, Feces microbiology, Gastrointestinal Microbiome genetics, HIV Infections microbiology, Meconium microbiology
- Abstract
There are limited data on meconium and faecal bacterial profiles from African infants and their mothers. We characterized faecal bacterial communities of infants and mothers participating in a South African birth cohort. Stool and meconium specimens were collected from 90 mothers and 107 infants at birth, and from a subset of 72 and 36 infants at 4-12 and 20-28 weeks of age, respectively. HIV-unexposed infants were primarily exclusively breastfed at 4-12 (49%, 26/53) and 20-28 weeks (62%, 16/26). In contrast, HIV-exposed infants were primarily exclusively formula fed at 4-12 (53%; 10/19) and 20-28 weeks (70%, 7/10). Analysis (of the bacterial 16S rRNA gene sequences of the V4 hypervariable region) of the 90 mother-infant pairs showed that meconium bacterial profiles [dominated by Proteobacteria (89%)] were distinct from those of maternal faeces [dominated by Firmicutes (66%) and Actinobacteria (15%)]. Actinobacteria predominated at 4-12 (65%) and 20-28 (50%) weeks. HIV-exposed infants had significantly higher faecal bacterial diversities at both 4-12 (p = 0.026) and 20-28 weeks (p = 0.002). HIV-exposed infants had lower proportions of Bifidobacterium (p = 0.010) at 4-12 weeks. Maternal faecal bacterial profiles were influenced by HIV status, feeding practices and mode of delivery. Further longitudinal studies are required to better understand how these variables influence infant and maternal faecal bacterial composition.
- Published
- 2018
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44. Establishing the role of rare coding variants in known Parkinson's disease risk loci.
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Jansen IE, Gibbs JR, Nalls MA, Price TR, Lubbe S, van Rooij J, Uitterlinden AG, Kraaij R, Williams NM, Brice A, Hardy J, Wood NW, Morris HR, Gasser T, Singleton AB, Heutink P, and Sharma M
- Subjects
- Datasets as Topic, Humans, Leucine-Rich Repeat Serine-Threonine Protein Kinase-2 genetics, Membrane Proteins genetics, Mitochondrial Proteins genetics, Muscle Proteins genetics, Risk, Seminal Plasma Proteins genetics, Genetic Loci genetics, Genetic Predisposition to Disease genetics, Genetic Variation genetics, Genome-Wide Association Study, Parkinson Disease genetics
- Abstract
Many common genetic factors have been identified to contribute to Parkinson's disease (PD) susceptibility, improving our understanding of the related underlying biological mechanisms. The involvement of rarer variants in these loci has been poorly studied. Using International Parkinson's Disease Genomics Consortium data sets, we performed a comprehensive study to determine the impact of rare variants in 23 previously published genome-wide association studies (GWAS) loci in PD. We applied Prix fixe to select the putative causal genes underneath the GWAS peaks, which was based on underlying functional similarities. The Sequence Kernel Association Test was used to analyze the joint effect of rare, common, or both types of variants on PD susceptibility. All genes were tested simultaneously as a gene set and each gene individually. We observed a moderate association of common variants, confirming the involvement of the known PD risk loci within our genetic data sets. Focusing on rare variants, we identified additional association signals for LRRK2, STBD1, and SPATA19. Our study suggests an involvement of rare variants within several putatively causal genes underneath previously identified PD GWAS peaks., (Copyright © 2017 Elsevier Inc. All rights reserved.)
- Published
- 2017
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45. NeuroChip, an updated version of the NeuroX genotyping platform to rapidly screen for variants associated with neurological diseases.
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Blauwendraat C, Faghri F, Pihlstrom L, Geiger JT, Elbaz A, Lesage S, Corvol JC, May P, Nicolas A, Abramzon Y, Murphy NA, Gibbs JR, Ryten M, Ferrari R, Bras J, Guerreiro R, Williams J, Sims R, Lubbe S, Hernandez DG, Mok KY, Robak L, Campbell RH, Rogaeva E, Traynor BJ, Chia R, Chung SJ, Hardy JA, Brice A, Wood NW, Houlden H, Shulman JM, Morris HR, Gasser T, Krüger R, Heutink P, Sharma M, Simón-Sánchez J, Nalls MA, Singleton AB, and Scholz SW
- Subjects
- Alleles, Apolipoproteins E genetics, Humans, Risk, Genetic Variation genetics, Genome-Wide Association Study methods, Genotyping Techniques methods, High-Throughput Screening Assays methods, Neurodegenerative Diseases genetics
- Abstract
Genetics has proven to be a powerful approach in neurodegenerative diseases research, resulting in the identification of numerous causal and risk variants. Previously, we introduced the NeuroX Illumina genotyping array, a fast and efficient genotyping platform designed for the investigation of genetic variation in neurodegenerative diseases. Here, we present its updated version, named NeuroChip. The NeuroChip is a low-cost, custom-designed array containing a tagging variant backbone of about 306,670 variants complemented with a manually curated custom content comprised of 179,467 variants implicated in diverse neurological diseases, including Alzheimer's disease, Parkinson's disease, Lewy body dementia, amyotrophic lateral sclerosis, frontotemporal dementia, progressive supranuclear palsy, corticobasal degeneration, and multiple system atrophy. The tagging backbone was chosen because of the low cost and good genome-wide resolution; the custom content can be combined with other backbones, like population or drug development arrays. Using the NeuroChip, we can accurately identify rare variants and impute over 5.3 million common SNPs from the latest release of the Haplotype Reference Consortium. In summary, we describe the design and usage of the NeuroChip array and show its capability for detecting rare pathogenic variants in numerous neurodegenerative diseases. The NeuroChip has a more comprehensive and improved content, which makes it a reliable, high-throughput, cost-effective screening tool for genetic research and molecular diagnostics in neurodegenerative diseases., (Published by Elsevier Inc.)
- Published
- 2017
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46. A combination of baseline plasma immune markers can predict therapeutic response in multidrug resistant tuberculosis.
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Ferrian S, Manca C, Lubbe S, Conradie F, Ismail N, Kaplan G, Gray CM, and Fallows D
- Subjects
- Adult, Biomarkers blood, C-Reactive Protein analysis, Chemokine CXCL10 blood, Female, Humans, Male, Microbial Sensitivity Tests, Middle Aged, Predictive Value of Tests, Serum Amyloid A Protein analysis, Tuberculosis, Multidrug-Resistant blood, Tuberculosis, Multidrug-Resistant immunology, Vascular Endothelial Growth Factor A blood, Antitubercular Agents therapeutic use, Tuberculosis, Multidrug-Resistant drug therapy
- Abstract
Objective: To identify plasma markers predictive of therapeutic response in patients with multidrug resistant tuberculosis (MDR-TB)., Methods: Fifty HIV-negative patients with active pulmonary MDR-TB were analysed for six soluble analytes in plasma at the time of initiating treatment (baseline) and over six months thereafter. Patients were identified as sputum culture positive or negative at baseline. Culture positive patients were further stratified by the median time to sputum culture conversion (SCC) as fast responders (< 76 days) or slow responders (≥ 76 days). Chest X-ray scores, body mass index, and sputum smear microscopy results were obtained at baseline., Results: Unsupervised hierarchical clustering revealed that baseline plasma levels of IP-10/CXCL10, VEGF-A, SAA and CRP could distinguish sputum culture and cavitation status of patients. Among patients who were culture positive at baseline, there were significant positive correlations between plasma levels of CRP, SAA, VEGF-A, sIL-2Rα/CD40, and IP-10 and delayed SCC. Using linear discriminant analysis (LDA) and Receiver Operating Curves (ROC), we showed that a combination of MCP-1/CCL2, IP-10, sIL-2Rα, SAA, CRP and AFB smear could distinguish fast from slow responders and were predictive of delayed SCC with high sensitivity and specificity., Conclusion: Plasma levels of specific chemokines and inflammatory markers measured before MDR-TB treatment are candidate predictive markers of delayed SCC. These findings require validation in a larger study.
- Published
- 2017
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47. Rare variants analysis of cutaneous malignant melanoma genes in Parkinson's disease.
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Lubbe SJ, Escott-Price V, Brice A, Gasser T, Pittman AM, Bras J, Hardy J, Heutink P, Wood NM, Singleton AB, Grosset DG, Carroll CB, Law MH, Demenais F, Iles MM, Bishop DT, Newton-Bishop J, Williams NM, and Morris HR
- Subjects
- Cohort Studies, DCC Receptor, Dopamine biosynthesis, Genotype, Humans, Melanins biosynthesis, Membrane Glycoproteins genetics, Monophenol Monooxygenase, Oxidoreductases genetics, Pigmentation genetics, Receptor, ErbB-4 genetics, Receptors, Cell Surface genetics, Risk, Tumor Suppressor Proteins genetics, Ubiquitin Thiolesterase genetics, Genetic Association Studies, Genetic Predisposition to Disease genetics, Genetic Variation genetics, Melanoma genetics, Parkinson Disease genetics, Skin Neoplasms genetics
- Abstract
A shared genetic susceptibility between cutaneous malignant melanoma (CMM) and Parkinson's disease (PD) has been suggested. We investigated this by assessing the contribution of rare variants in genes involved in CMM to PD risk. We studied rare variation across 29 CMM risk genes using high-quality genotype data in 6875 PD cases and 6065 controls and sought to replicate findings using whole-exome sequencing data from a second independent cohort totaling 1255 PD cases and 473 controls. No statistically significant enrichment of rare variants across all genes, per gene, or for any individual variant was detected in either cohort. There were nonsignificant trends toward different carrier frequencies between PD cases and controls, under different inheritance models, in the following CMM risk genes: BAP1, DCC, ERBB4, KIT, MAPK2, MITF, PTEN, and TP53. The very rare TYR p.V275F variant, which is a pathogenic allele for recessive albinism, was more common in PD cases than controls in 3 independent cohorts. Tyrosinase, encoded by TYR, is the rate-limiting enzyme for the production of neuromelanin, and has a role in the production of dopamine. These results suggest a possible role for another gene in the dopamine-biosynthetic pathway in susceptibility to neurodegenerative Parkinsonism, but further studies in larger PD cohorts are needed to accurately determine the role of these genes/variants in disease pathogenesis., (Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.)
- Published
- 2016
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48. Respiratory microbes present in the nasopharynx of children hospitalised with suspected pulmonary tuberculosis in Cape Town, South Africa.
- Author
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Dube FS, Kaba M, Robberts FJ, Ah Tow L, Lubbe S, Zar HJ, and Nicol MP
- Subjects
- Child, Child, Preschool, Coinfection, Female, Hospitalization, Humans, Infant, Male, Multiplex Polymerase Chain Reaction, Nasopharynx virology, Respiratory Tract Infections virology, South Africa, Sputum microbiology, Tuberculosis, Pulmonary microbiology, Nasopharynx microbiology, Respiratory Tract Infections microbiology, Tuberculosis, Pulmonary diagnosis
- Abstract
Background: Lower respiratory tract infection in children is increasingly thought to be polymicrobial in origin. Children with symptoms suggestive of pulmonary tuberculosis (PTB) may have tuberculosis, other respiratory tract infections or co-infection with Mycobacterium tuberculosis and other pathogens. We aimed to identify the presence of potential respiratory pathogens in nasopharyngeal (NP) samples from children with suspected PTB., Method: NP samples collected from consecutive children presenting with suspected PTB at Red Cross Children's Hospital (Cape Town, South Africa) were tested by multiplex real-time RT-PCR. Mycobacterial liquid culture and Xpert MTB/RIF was performed on 2 induced sputa obtained from each participant. Children were categorised as definite-TB (culture or qPCR [Xpert MTB/RIF] confirmed), unlikely-TB (improvement of symptoms without TB treatment on follow-up) and unconfirmed-TB (all other children)., Results: Amongst 214 children with a median age of 36 months (interquartile range, [IQR] 19-66 months), 34 (16 %) had definite-TB, 86 (40 %) had unconfirmed-TB and 94 (44 %) were classified as unlikely-TB. Moraxella catarrhalis (64 %), Streptococcus pneumoniae (42 %), Haemophilus influenzae spp (29 %) and Staphylococcus aureus (22 %) were the most common bacteria detected in NP samples. Other bacteria detected included Mycoplasma pneumoniae (9 %), Bordetella pertussis (7 %) and Chlamydophila pneumoniae (4 %). The most common viruses detected included metapneumovirus (19 %), rhinovirus (15 %), influenza virus C (9 %), adenovirus (7 %), cytomegalovirus (7 %) and coronavirus O43 (5.6 %). Both bacteria and viruses were detected in 73, 55 and 56 % of the definite, unconfirmed and unlikely-TB groups, respectively. There were no significant differences in the distribution of respiratory microbes between children with and without TB. Using quadratic discriminant analysis, human metapneumovirus, C. pneumoniae, coronavirus 043, influenza virus C virus, rhinovirus and cytomegalovirus best discriminated children with definite-TB from the other groups of children., Conclusions: A broad range of potential respiratory pathogens was detected in children with suspected TB. There was no clear association between TB categorisation and detection of a specific pathogen. Further work is needed to explore potential pathogen interactions and their role in the pathogenesis of PTB.
- Published
- 2016
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49. Aetiology of childhood pneumonia in a well vaccinated South African birth cohort: a nested case-control study of the Drakenstein Child Health Study.
- Author
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Zar HJ, Barnett W, Stadler A, Gardner-Lubbe S, Myer L, and Nicol MP
- Subjects
- Bordetella pertussis isolation & purification, Case-Control Studies, Child, Preschool, Cross-Sectional Studies, Female, Hospitalization statistics & numerical data, Humans, Incidence, Infant, Longitudinal Studies, Male, Orthomyxoviridae isolation & purification, Pneumonia epidemiology, Pneumonia prevention & control, Respiratory Syncytial Viruses, South Africa epidemiology, Sputum virology, Pneumococcal Vaccines therapeutic use, Pneumonia virology
- Abstract
Background: Pneumonia is a leading cause of mortality and morbidity in children globally. The cause of pneumonia after introduction of the 13-valent pneumococcal conjugate vaccine (PCV13) has not been well studied in low-income and middle-income countries, and most data are from cross-sectional studies of children admitted to hospital. We aimed to longitudinally investigate the incidence and causes of childhood pneumonia in a South African birth cohort., Methods: We did a nested case-control study of children in the Drakenstein Child Health Study who developed pneumonia from May 29, 2012, to Dec 1, 2014. Children received immunisations including acellular pertussis vaccine and PCV13. A nested subgroup had nasopharyngeal swabs collected every 2 weeks throughout infancy. We identified pneumonia episodes and collected blood, nasopharyngeal swabs, and induced sputum specimens. We used multiplex real-time PCR to detect pathogens in nasopharyngeal swabs and induced sputum of pneumonia cases and in nasopharyngeal swabs of age-matched and site-matched controls. To show associations between organisms and pneumonia we used conditional logistic regression; results are presented as odds ratios (ORs) with 95% CIs., Findings: 314 pneumonia cases occurred (incidence of 0·27 episodes per child-year, 95% CI 0·24-0·31; median age 5 months [IQR 3-9]) in 967 children during 1145 child-years of follow-up. 60 (21%) cases of pneumonia were severe (incidence 0·05 episodes per child-year [95% CI 0·04-0·07]) with a case fatality ratio of 1% (three deaths). A median of five organisms (IQR 4-6) were detected in cases and controls with nasopharyngeal swabs, and a median of six organisms (4-7) recorded in induced sputum (p=0·48 compared with nasopharyngeal swabs). Bordetella pertussis (OR 11·08, 95% CI 1·33-92·54), respiratory syncytial virus (8·05, 4·21-15·38), or influenza virus (4·13, 2·06-8·26) were most strongly associated with pneumonia; bocavirus, adenovirus, parainfluenza virus, Haemophilus influenzae, and cytomegalovirus were also associated with pneumonia. In cases, testing of induced sputum in addition to nasopharyngeal swabs provided incremental yield for detection of B pertussis and several viruses., Interpretation: Pneumonia remains common in this highly vaccinated population. Respiratory syncytial virus was the most frequently detected pathogen associated with pneumonia; influenza virus and B pertussis were also strongly associated with pneumonia. Testing of induced sputum increases the yield for detection of several organisms. New vaccines and strategies are needed to address the burden of childhood pneumonia., Funding: Bill & Melinda Gates Foundation, Medical Research Council South Africa, National Research Foundation South Africa, National Institute of Health, and H3Africa., (Copyright © 2016 Elsevier Ltd. All rights reserved.)
- Published
- 2016
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50. Distinct clinical and neuropathological features of G51D SNCA mutation cases compared with SNCA duplication and H50Q mutation.
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Kiely AP, Ling H, Asi YT, Kara E, Proukakis C, Schapira AH, Morris HR, Roberts HC, Lubbe S, Limousin P, Lewis PA, Lees AJ, Quinn N, Hardy J, Love S, Revesz T, Houlden H, and Holton JL
- Subjects
- Age of Onset, Aged, Antiparkinson Agents therapeutic use, Codon genetics, Dementia genetics, Dementia pathology, Disease Progression, Female, Gene Duplication, Humans, Inclusion Bodies ultrastructure, Male, Middle Aged, Multiple System Atrophy pathology, Parkinson Disease drug therapy, Parkinson Disease pathology, Parkinson Disease psychology, Pedigree, Protein Conformation, Protein Processing, Post-Translational, Symptom Assessment, Young Adult, alpha-Synuclein chemistry, Amino Acid Substitution, Brain pathology, Multiple System Atrophy genetics, Mutation, Missense, Parkinson Disease genetics, Point Mutation, alpha-Synuclein genetics
- Abstract
Background: We and others have described the neurodegenerative disorder caused by G51D SNCA mutation which shares characteristics of Parkinson's disease (PD) and multiple system atrophy (MSA). The objective of this investigation was to extend the description of the clinical and neuropathological hallmarks of G51D mutant SNCA-associated disease by the study of two additional cases from a further G51D SNCA kindred and to compare the features of this group with a SNCA duplication case and a H50Q SNCA mutation case., Results: All three G51D patients were clinically characterised by parkinsonism, dementia, visual hallucinations, autonomic dysfunction and pyramidal signs with variable age at disease onset and levodopa response. The H50Q SNCA mutation case had a clinical picture that mimicked late-onset idiopathic PD with a good and sustained levodopa response. The SNCA duplication case presented with a clinical phenotype of frontotemporal dementia with marked behavioural changes, pyramidal signs, postural hypotension and transiently levodopa responsive parkinsonism. Detailed post-mortem neuropathological analysis was performed in all cases. All three G51D cases had abundant α-synuclein pathology with characteristics of both PD and MSA. These included widespread cortical and subcortical neuronal α-synuclein inclusions together with small numbers of inclusions resembling glial cytoplasmic inclusions (GCIs) in oligodendrocytes. In contrast the H50Q and SNCA duplication cases, had α-synuclein pathology resembling idiopathic PD without GCIs. Phosphorylated α-synuclein was present in all inclusions types in G51D cases but was more restricted in SNCA duplication and H50Q mutation. Inclusions were also immunoreactive for the 5G4 antibody indicating their highly aggregated and likely fibrillar state., Conclusions: Our characterisation of the clinical and neuropathological features of the present small series of G51D SNCA mutation cases should aid the recognition of this clinico-pathological entity. The neuropathological features of these cases consistently share characteristics of PD and MSA and are distinct from PD patients carrying the H50Q or SNCA duplication.
- Published
- 2015
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