43 results on '"Donfack J"'
Search Results
2. In vitro leishmanicidal activity of some Cameroonian medicinal plants
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Hubert, Donfack J., Céline, Nkenfou, Michel, Noubom, Gogulamudi, V. Reddy, Florence, Ngueguim T., Johnson, Boampong N., Bonaventure, Ngadjui T., Singh, Inder P., and Sehgal, Rakesh
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- 2013
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3. In vitro hepatoprotective and antioxidant activities of crude extract and isolated compounds from Ficus gnaphalocarpa
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Hubert, Donfack J., Dawe, Amadou, Florence, Ngueguim T., Gilbert, Kapche D. W. F., Angele, Tchana N., Buonocore, D., Finzi, P. Vita, Vidari, G., Bonaventure, Ngadjui T., Marzatico, Fulvio, and Paul, Moundipa F.
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- 2011
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4. Etude histologique des effets de l'extrait aqueux des feuilles de Laportea aestuans sur la régénération osseuse chez le rat
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Ngueguim T., Florence, Cannet, Catherine, Nguindjel, Daniel, Dzeufiet Djomeni, Paul Désiré, Donfack, J. Hubert, Théophile, DIMO, and kamtchouing, pierre
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fracture ,Laportea aestuans ,osteoblastic activity ,histology ,Laporte aestuans ,activité ostéoblastique ,histologie - Abstract
Laportea. aestuans (Urticacea) est une plante utilisée dans la région du Centre Cameroun pour le traitement des fractures. La présente étude a pour but d’évaluer par analyse histologique les effets ostéo-inducteurs de l’extrait aqueux des feuilles de L. aestuans chez la rate (Wistar). Une cavité a été créée dans la portion antérieure de la diaphyse du fémur. L’extrait aqueux de L. aestuans a été administré quotidienne par voie orale (100-400 mg/kg) pendant deux semaines. Au terme de la période expérimentale, les animaux ont été sacrifiés et les fémurs fixés dans du formol 10% tamponné puis transférés dans de l’éthanol à 70%. Ils ont ensuite été déshydratés et inclus en paraffine. Des coupes de 5µm ont été réalisées et les colorations suivantes faites : - H&E - Picrosirius et observation en lumière polarisée. Les animaux fracturés ne recevant aucun traitement ont présenté une structure 150 Revue Française d’Histotechnologie 2018 - Vol. 30 - n°1 osseuse désorganisée avec la présence d’ostéoblastes et d’ostéocytes dans leurs lacunes. En lumière polarisée ces animaux ont présenté un aspect d’«os tissé» se traduisant par une trame collagénique peu organisée et une faible minéralisation. Les animaux traités à l’extrait de plante ont présenté une structure du cal osseux de plus en plus dense avec plus ostéoblastes et de plus en plus d’ostéocytes dans les lacunes à toutes les doses. En lumière polarisée et à la dose de 400 mg/kg d’extrait de plante, les animaux ont montré un début d’organisation lamellaire parallèle au sein de l’os tissé. L’extrait induirait une activation ostéoblastique, conduisant à une réparation osseuse plus rapide, ce qui justifierait son utilisation empirique dans le traitement des fractures., Laportea aestuans (Urticaceae) is a plant used in the Cameroon centre region for fracture healing. The purpose of this study is to evaluate by histological analysis, the osteoinductive effect of the aqueous leaves plant extract of L. aestuans in female Wistar rats. A drill hole injury was created in the diaphysis of the femur. The aqueous extract of L. aestuans was administered orally (100-400 mg/kg) for two weeks. At the end of the experimental period, the animals were sacrificed and the femurs fixed in 10% buffered formalin and then transferred into 70% ethanol. They were then dehydrated and embedded in paraffin. Sections of 5µm were made and the following colorations realized : H & E, Picrosirius staining and observation in polarized light. Fractured animals receiving no treatment exhibited a disorganized bone structure with the presence of osteoblasts and osteocytes in their lacuna. In polarized light, these animals presented an appearance of «woven bone» resulting in a poorly organized collagen structure and low mineralization. Animals treated with plant extract exhibited an increasingly dense callus structure with more osteoblasts and more and more osteocytes in the lacuna at all doses. In polarized light and at the dose of 400 mg/kg, the animals showed a parallel lamellar organization within the woven bone. Thus, the extract would induce osteoblastic activation, leading to faster bone repair, justifying its empirical use in the treatment of bone fractures.
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- 2018
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5. Novel, sensitive and low-cost diagnostic tests for 'river blindness' - detection of specific antigens in tears, urine and dermal fluid
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Ngu, J. L., Nkenfou, Céline, Capuli, Efigenia, McMoli, Theodosia E., Perler, Francine, Mbwagbor, Josephine, Tume, Christopher, Nlatte, Odjame B., Donfack, J., and Asonganyi, T.
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- 1998
6. Gene Conversion and Different Population Histories May Explain the Contrast between Polymorphism and Linkage Disequilibrium Levels
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Frisse, L., Hudson, R.R., Bartoszewicz, A., Wall, J.D., Donfack, J., and Di Rienzo, A.
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- 2001
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7. Hepato-protective, antioxidant activities and acute toxicity of a stem bark extract of Erythrina senegalensis DC
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Njayou, F, Moundipa, P, Donfack, J, Chuisseu, D, Tchana, A, Ngadjui, B, and Tchouanguep, F
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This study aimed at evaluating the in vitro antioxidant and hepatoprotective activities of different stem bark extracts of Erythrina senegalensis prepared with ethanol, and the in vivo hepatoprotective activity and acute toxicity of the best extract. The 2, 4-diphenyl-1-picryl-hydrazil (DPPH) and microsomal lipid peroxidation (MLP) models, and the rat liver slices system were respectively used for the in vitro study. The Methylene chloride/methanol (1:1 v/v) (Emc) and 40% ethanolic (E40) extracts were more efficient in inhibiting MLP and in scavenging DPPH radical. However, E40 was most effective with regards to lactate dehydrogenase (LDH) leakage inhibition from rat liver slices intoxicated with carbon tetrachloride (CCl4). The in vivo hepatoprotective activity was evaluated against CCl4-induced hepatotoxicity in rats. The E40 extract (100 mg/Kg) significantly reduced the increase in ALT, AST and lipid peroxidation in liver homogenate, showing that the extract is as protective as silymarin at the same dose. Acute toxicity was evaluated in mice and E40 did not produce any behavioural changes or mortality even at an oral dose of 16 g/kg. The extract was found to contain antioxidant classes of compounds (flavonoids and polyphenols). In conclusion, the E40 extract of E. senegalensis could be an important source of hepatoprotective compounds.Key words: Erythrina senegalensis, stem bark extract, antioxidant, hepatoprotective, carbon tetrachloride.
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- 2010
8. Age of child, more than HPV type, is associated with clinical course in recurrent respiratory papillomatosis
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Buchinsky, FJ, Donfack, J, Derkay, CS, Choi, SS, Conley, SF, Myer, CM, McClay, JE, Campisi, P, Wiatrak, BJ, Sobol, SE, Schweinfurth, JM, Tsuji, DH, Hu, FZ, Rockette, HE, Ehrlich, GD, Post, JC, Buchinsky, FJ, Donfack, J, Derkay, CS, Choi, SS, Conley, SF, Myer, CM, McClay, JE, Campisi, P, Wiatrak, BJ, Sobol, SE, Schweinfurth, JM, Tsuji, DH, Hu, FZ, Rockette, HE, Ehrlich, GD, and Post, JC
- Abstract
Background: RRP is a devastating disease in which papillomas in the airway cause hoarseness and breathing difficulty. The disease is caused by human papillomavirus (HPV), 6 or 11 and is very variable. Patients undergo multiple surgeries to maintain a patent airway and in order to communicate vocally. Several small studies have been published in which most have noted that HPV 11 is associated with a more aggressive course. Methodology/Principal Findings: Papilloma biopsies were taken from patients undergoing surgical treatment of RRP and were subjected to HPV typing. 118 patients with juvenile-onset RRP with a least 1 year of clinical data and infected with a single HPV type were analyzed. HPV 11 was encountered in 40% of the patients. By our definition, most of the patients in the sample (81%) had run an aggressive course. The odds of a patient with HPV 11 running an aggressive course were 3.9 times higher that that of patients with HPV 6 (Fisher's exact p=0.017). However, clinical course was more closely associated with age of the patient (at diagnosis and at the time of the current surgery) than with HPV type. Patients with HPV 11 were diagnosed at a younger age (2.4y) than were those with HPV 6 (3.4y) (p=0.014). Both by multiple linear regression and by multiple logistics regression HPV type was only weakly associated with metrics of disease course when simultaneously accounting for age. Conclusions/Significance Abstract: The course of RRP is variable and a quarter of the variability can be accounted for by the age of the patient. HPV 11 is more closely associated with a younger age at diagnosis than it is associated with an aggressive clinical course. These data suggest that there are factors other than HPV type and age of the patient that determine disease course. © 2008 Buchinsky et al.
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- 2008
9. The Curative and Prophylactic Effects of Xylopic Acid onPlasmodium bergheiInfection in Mice
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Boampong, J. N., primary, Ameyaw, E. O., additional, Aboagye, B., additional, Asare, K., additional, Kyei, S., additional, Donfack, J. H., additional, and Woode, E., additional
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- 2013
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10. Ethnopharmacological Investigation and In vitro Anti-giardial Activity of Some Cameroonian Medicinal Plants
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Hubert, Donfack J., additional, Celine, Nkenfou, additional, Johnson, Boampong N., additional, Florence, Ngueguim T., additional, Bonaventur, Ngadjui T., additional, Gupta, Isha, additional, Reddy, G. Van., additional, Singh, Inder P., additional, and Sehgal, Rakesh, additional
- Published
- 2012
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11. In vitro hepatoprotective and antioxidant activities of crude extract and isolated compounds from Ficus gnaphalocarpa
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Hubert, Donfack J., primary, Dawe, Amadou, additional, Florence, Ngueguim T., additional, Gilbert, Kapche D. W. F., additional, Angele, Tchana N., additional, Buonocore, D., additional, Finzi, P. Vita, additional, Vidari, G., additional, Bonaventure, Ngadjui T., additional, Marzatico, Fulvio, additional, and Paul, Moundipa F., additional
- Published
- 2010
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12. The Curative and Prophylactic Effects of Xylopic Acid on Plasmodium berghei Infection in Mice.
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Boampong, J. N., Ameyaw, E. O., Aboagye, B., Asare, K., Kyei, S., Donfack, J. H., and Woode, E.
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PLASMODIUM berghei ,MALARIA treatment ,PROTOZOAN diseases ,ANTIMALARIALS ,ARTEMISININ ,ANTIPYRETICS ,XYLOPIA - Abstract
Efforts have been intensified to search for more effective antimalarial agents because of the observed failure of some artemisinin-based combination therapy (ACT) treatments of malaria in Ghana. Xylopic acid, a pure compound isolated from the fruits of the Xylopia aethiopica, was investigated to establish its attributable prophylactic, curative antimalarial, and antipyretic properties. The antimalarial properties were determined by employing xylopic acid (10-100mg/kg) in ICR mice infected with Plasmodium berghei. Xylopic acid exerted significant (P < 0.05) effects on P. berghei infection similar to artemether/lumefantrine, the standard drug. Furthermore, it significantly (P < 0.05) reduced the lipopolysaccharide- (LPS-) induced fever in Sprague-Dawley rats similar to prednisolone. Xylopic acid therefore possesses prophylactic and curative antimalarial as well as antipyretic properties which makes it an ideal antimalarial agent. [ABSTRACT FROM AUTHOR]
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- 2013
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13. Aqueous extract of Peperomia pellucida (L.) HBK accelerates fracture healing in Wistar rats
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Ngueguim Tsofack Florence, Sakouong Talle Suewellyne Huguette, Donfack Jean Hubert, Gounoue Kamkumo Raceline, Dzeufiet Djomeni Paul Desire, Kamtchouing Pierre, and Dimo Theophile
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Drill-hole ,Peperomia pellucida ,Alkaline phosphate ,Fracture healing ,Haematological parameters ,Other systems of medicine ,RZ201-999 - Abstract
Abstract Background Peperomia pellucida (L.) HBK is consumed as vegetable and used in Cameroonian traditional medicine for the management of diseases and for fracture healing. Therefore the aim of this study was to evaluate the effects of the aqueous whole plant extract of Peperomia pellucida on fracture healing in female Wistar rats. Methods A drill hole injury was created by inserting a drill bit inthe diaphysis of the femur. The aqueous extract of the whole plant of Peperomia pellucida was administered orally at the doses of 100, 200 and 400 mg/kg to adult female Wistar rats. The vehicle (distilled water) was given to the control. Besides these rats, one group of rats without fracture received the extract (400 mg/kg). After 14 days of treatment, the rats were sacrificed under anesthesia and the effects of the extract were evaluated on body weight, the relative weights of organs (femurs, uteri and ovaries) and on hematology. Bone (calcium, phosphorus, alkaline phosphatase) and serum biochemical parameters (calcium, phosphorus, alkaline phosphatase) were also evaluated. Radiological and histological tests were carried out on the femurs. The mineral content of the plant extract was also investigated. Results The extract induced an increase in body weight at high dose and in WBCs count at low doses. Aqueous extract from Peperomia pellucida increased bone calcium at lowest dose but maintained this parameter at normal range at high dose in fractured rat. Alkaline phophatase and phosphorus concentrations reduced significantly (p
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- 2017
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14. VIH, VHB et les facteurs favorisant en milieu universitarie au Cameroun: cas de l’Université de Dschang dans la Region de l’Ouest
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Sanou Sobze, M., Onohiol, J. F., Fokam, J., Donfack, J. H., Nkamedjie Pete, P. M., GHYSLAINE BRUNA DJEUNANG DONGHO, Selle Massong, F. M., Colizzi, V., Watcho, P., and Gianluca Russo
15. Variation in conserved non-coding sequences on chromosome 5q and susceptibility to asthma and atopy
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Dubchak Inna, Kurz Thorsten, Tan Zheng, Schneider Daniel H, Donfack Joseph, Frazer Kelly A, and Ober Carole
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Diseases of the respiratory system ,RC705-779 - Abstract
Abstract Background Evolutionarily conserved sequences likely have biological function. Methods To determine whether variation in conserved sequences in non-coding DNA contributes to risk for human disease, we studied six conserved non-coding elements in the Th2 cytokine cluster on human chromosome 5q31 in a large Hutterite pedigree and in samples of outbred European American and African American asthma cases and controls. Results Among six conserved non-coding elements (>100 bp, >70% identity; human-mouse comparison), we identified one single nucleotide polymorphism (SNP) in each of two conserved elements and six SNPs in the flanking regions of three conserved elements. We genotyped our samples for four of these SNPs and an additional three SNPs each in the IL13 and IL4 genes. While there was only modest evidence for association with single SNPs in the Hutterite and European American samples (P < 0.05), there were highly significant associations in European Americans between asthma and haplotypes comprised of SNPs in the IL4 gene (P < 0.001), including a SNP in a conserved non-coding element. Furthermore, variation in the IL13 gene was strongly associated with total IgE (P = 0.00022) and allergic sensitization to mold allergens (P = 0.00076) in the Hutterites, and more modestly associated with sensitization to molds in the European Americans and African Americans (P < 0.01). Conclusion These results indicate that there is overall little variation in the conserved non-coding elements on 5q31, but variation in IL4 and IL13, including possibly one SNP in a conserved element, influence asthma and atopic phenotypes in diverse populations.
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- 2005
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16. Chromolaena odorata (L.) R. M. King and H. Robinson Leaves Aqueous Extract Improves the Femoral Head in Ethanol-Induced Osteonecrosis in Rats.
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Tsofack Ngueguim F, Kamkumo Gounoue R, Hubert Donfack J, Manefen Simo S, Jouonzo J, Ngapout Fifen R, Djomeni Dzeufiet PD, and Dimo T
- Abstract
Chronic alcohol consumption damages bone formation and causes bone pathology, including osteonecrosis of the femoral head. The aim of this work was to evaluate the effects of the leaf aqueous extract of Chromolaena odorata ( C. odorata ) on the femoral head in ethanol-induced osteonecrosis in rats. Animals received alcohol (40°) at 3 g/kg for 12 weeks. A group of animals were sacrificed to attest to the instalment of osteonecrosis by using histopathological analysis. The remaining animals received alcohol concomitantly with the plant extract (150, 300, or 600 mg/kg) or diclofenac (1 mg/kg) for 28 additional days. At the end of the experimental period, biochemical parameters including total cholesterol, triglycerides, calcium, alkaline phosphatase (ALP), reduced glutathione (GSH), malondialdehyde (MDA), nitrite, superoxide dismutase (SOD), and catalase activities were measured. Histopathological and histomorphometry analyses of femurs were also assessed. The administration of alcohol, irrespective of the experimental period, induced a significant increase in total cholesterol ( p < 0.05) and triglyceride ( p < 0.01) and a decrease in ALP ( p < 0.05) and calcium ( p < 0.05- p < 0.001) levels. Intoxicated animals showed an alteration in oxidative stress parameters accompanied by a significant drop in bone cortical thickness and density with necrosis and marked bone resorption. The concomitant administration of the plant with ethanol reversed the alcohol-induced bone defect, characterized by the improvement of the lipid profile ( p < 0.001), bone calcium concentration ( p < 0.05), bone ALP activity ( p < 0.001), oxidative stress parameters, improved cortical bone thickness ( p < 0.01), and bone density ( p < 0.05). These results are supported by the absence of bone resorption with an obvious effect at a dose of 300 mg/kg. The pharmacological effect of the extract on ethanol-induced osteonecrosis of the femoral head is probably due to its osteogenic, hypolipidemic, and antioxidant properties, justifying its use in Cameroonian folk medicine for articulation and bone pain management., Competing Interests: The authors declare that they have no conflicts of interest., (Copyright © 2023 Florence Tsofack Ngueguim et al.)
- Published
- 2023
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17. Assessing agreement among crime scene measurement methods.
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Lawas M, Williams SY, Jameson S, Gonzalez AR, Ernst P, and Donfack J
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- Documentation, Crime, Forensic Sciences methods
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A critical concern with crime scene documentation is the accuracy with which a crime scene can be reconstructed. Here, we discuss the accuracy of eight documentation methods as a function of measurement distance between reference ground targets in an outdoor scene. The relative accuracy of each documentation method was assessed with respect to a widely accepted and well-established standard method for land surveying, Total Station, from which measurements served as "ground truth" or reference data. For the majority of methods, the actual relative difference between measurements when compared to Total Station was small (less than a quarter of an inch). Measurements from FARO LiDAR agreed the most with to those of Total Station, while drone without the use of ground control points (GCPs) agreed the least. GCPs or a reference scale were also found to be important in mitigating increasing imprecision with increasing distance when measuring between two targets ~9-85 ft apart via drone and orthomosaic methods. Additionally, there were no statistical differences in the use of 2D (horizontal) or 3D (slope) measurement configurations for the Total Station. Overall, linear regression of difference plots did not reveal meaningful correlation between increasing distance measured and the error of a method when compared to Total Station. As more measurement methods become available, and the need for training and validating new tools become a necessity, these results point to the importance of establishing a ground truth or known distance range on which crime scene measurement methods can be validated., (Published 2022. This article is a U.S. Government work and is in the public domain in the USA.)
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- 2022
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18. Assessing Single-Source Reproducibility of Human Head Hair Peptide Profiling from Different Regions of the Scalp.
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Lawas M, Jones KF, Mason KE, Anex DS, Carlson TL, Forger LV, Eckenrode BA, Hart B, and Donfack J
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- Adult, Chromatography, Liquid, Female, Forensic Genetics methods, Humans, Keratins metabolism, Male, Middle Aged, Pilot Projects, Polymorphism, Single Nucleotide, Reproducibility of Results, Tandem Mass Spectrometry, Young Adult, Hair metabolism, Peptides metabolism, Scalp metabolism
- Abstract
Neither microscopical hair comparisons nor mitochondrial DNA sequencing alone, or together, constitutes a basis for personal identification. Due to these limitations, a complementary technique to compare questioned and known hair shafts was investigated. Recently, scientists from Lawrence Livermore National Laboratory's Forensic Science Center and other collaborators developed a peptide profiling technique, which can infer non-synonymous single nucleotide polymorphisms (SNPs) preserved in hair shaft proteins as single amino acid polymorphisms (SAPs). In this study, peptide profiling was evaluated to determine if it can meet forensic expectations when samples are in limited quantities with the possibility that hair samples collected from different areas of a single donor's scalp (i.e., single source) might not exhibit the same SAP profile. The average dissimilarity, percent differences in SAP profiles within each source, ranged from 0% difference to 29%. This pilot study suggests that more work is needed before peptide profiling of hair can be considered for forensic comparisons., (Published by Elsevier B.V.)
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- 2021
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19. A quantitative method for selecting a hair for nulear DNA analysis.
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Lawas M, Otterstatter LM, Forger LV, Gray JE, and Donfack J
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- Fluorescent Dyes, Hair ultrastructure, Humans, Indoles, Microsatellite Repeats, Microscopy, Fluorescence, Polymerase Chain Reaction, Staining and Labeling, Cell Nucleus metabolism, DNA metabolism, DNA Fingerprinting, Hair metabolism
- Abstract
This study evaluated a quantitative method to predict the success of nuclear DNA (nuDNA) typing for head hair roots, using the minor-groove DNA binding dye, 4', 6-diamidino-2-phenylindole (DAPI). The procedure was successful in staining nuclear material in hair roots, regardless of soft tissue presence or growth phase. We found that the dye can even reveal an abundance of visible nuclei in hairs that were previously assumed to be unsuitable for nuDNA analysis (e.g., telogen hairs). The value of DAPI staining is particularly evident when considering the STR typing results for telogen hairs. Here, telogen hairs with greater than 100 visible nuclei frequently produced full or high-partial STR profiles, while telogen hairs with fewer than 100 visible nuclei rarely resulted in >20 % STR allele recovery. In addition, our findings indicated no interference by DAPI in the forensic examination of hair evidence, including preparation of hairs on microscopic slides, microscopic examination, DNA extraction, quantitative PCR, and short tandem repeat (STR) typing. Furthermore, the method remained steadfast for hairs washed by sonication as well as hairs retrieved from Permount™ mounting medium. When validated, this simple, quick, and quantitative screening method can be used in casework to select a hair for nuDNA analysis, especially for hairs that were previously sent directly for mitochondrial (mt) DNA analysis based on the lack of adhering soft tissue, regardless of growth phase. Conversely, nuDNA degradation may exist in hairs which exhibit microscopic characteristics typically associated with a potential to generate successful nuclear DNA profile including stretched roots with attached root sheath. DAPI staining of hairs gives forensic examiners the ability to have more information, other than growth phase, when selecting a hair or hairs for possible nuDNA analysis., (Copyright © 2020 Elsevier B.V. All rights reserved.)
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- 2020
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20. Effect of different extracts and fractions of Senecio biafrae (Oliv. &Hiern) J. Moore on in vivo and in vitro parameters of folliculogenesis in experimental animals.
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Lienou LL, Telefo PB, Rodrigues GQ, Donfack JN, Araújo RA, Bruno JB, Njimou JR, Mbemya TG, Santos RR, Souza JF, Figueiredo JR, and Rodrigues APR
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- Animals, Cholesterol metabolism, Estradiol blood, Female, Follicle Stimulating Hormone blood, Luteinizing Hormone blood, Ovary metabolism, Progesterone blood, Rats, Wistar, Swine, Ovary drug effects, Plant Extracts pharmacology, Senecio
- Abstract
Background: Senecio biafrae is a medicinal plant widely used in traditional medicine to cure female infertility. Some effects have been pharmacologically demonstrated on immature female rats but in vivo and in vitro investigations are still necessary for determining its mechanism of action. The aim of the present study was to evaluate the estrogenic and FSH-like effects of the plant extracts and fractions on some fertility parameters in immature female rats and on in vitro survival and growth of swine preantral follicles., Methods: 21-23 days old female Wistar rats orally received extracts and fractions of S. biafrae at 0, 8 and 64 mg/kg doses over 20 days. The LH, FSH, estradiol and progesterone serum levels were evaluated as well as the ovarian cholesterol, uterus and ovaries masses and proteins. The numbers of follicles at different developmental stages were recorded in ovarian cortexes after histology. Slices of swine ovarian cortexes were cultured along 1 or 7 days in alpha-minimum essential medium (α-MEM) and fixed for morphological analysis of preantral follicles. The fresh control, cultured control (CIV control) and different Senecio biafrae-treated ovarian fragments were analyzed for preantral follicles development. Treatments that showed the best follicle growth in culture were submitted to AgNOR test. The aqueous and MeOH/CH
2 Cl2 extracts as well as the ethyl acetate and hexane fractions of S. biafrae were submitted to the HPLC for analysis of polyphenolic secondary metabolites., Results: Ovarian and uterine proteins were significantly high (p < 0.01) in animals treated with the two dosages of ethyl acetate and n-butanol fractions. The same result was recorded with uterine proteins in animals treated with the hexane fraction. The FSH level significantly dropped with all ethanolic extract doses and with the 64 mg/kg dosage of the methanol/methylene chloride (MeOH/CH2 Cl2 ) extract while LH was reduced (p < 0.01) in almost all the treated groups. Estradiol level was significantly increased (p < 0.001) in the three groups receiving the extracts, but reduced (p < 0.001) in the three groups receiving the fractions of the plant. The progesterone level increased with almost all the treated groups. Primary and secondary follicles augmented (p < 0.01) in MeOH/CH2 Cl2 extract and n-butanol fraction while tertiary follicles increased with the same extract and the ethyl acetate fraction (p < 0.05). Treatments with aqueous and ethanolic extracts as well as ethyl acetate fraction led to a significant increase (p < 0.05) in the number of morphologically normal follicles after 7 days of culture as compared to the CIV control. The number of AgNOR dots per follicle was significantly low (p < 0.05) in all cultured groups as compared to the fresh control, except the ethyl acetate 2.8 ng/ml dosage. The same observation was done with AgNOR dots per cell in the 2.8 ng/ml dosage aqueous extract-treated fragments. The phenolic compounds mainly encountered in the plant, independently of the extract or fraction are apigenin, eugenol and rutin., Conclusion: Extracts and fractions of S. biafrae have an important FSH-like effect which induces follicular survival and growth., Competing Interests: Declaration of competing interest The authors declare that there are no conflicts of interest., (Copyright © 2020 Elsevier B.V. All rights reserved.)- Published
- 2020
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21. Assessing protein sequencing in human single hair shafts of decreasing lengths.
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Jones KF, Carlson TL, Eckenrode BA, and Donfack J
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- Chromatography, Liquid, Female, Humans, Keratins chemistry, Mass Spectrometry, Polymorphism, Genetic, Proteins analysis, Proteomics, Specimen Handling methods, Trypsin, Young Adult, Forensic Genetics methods, Hair anatomy & histology, Hair chemistry, Sequence Analysis, Protein methods
- Abstract
Hair evidence is commonly found at crime scenes and is first analyzed using microscopy techniques. Hair can be processed for DNA analysis, but nuclear DNA analysis may result in a partial or no profile, and mitochondrial DNA analysis is less discriminatory. Single amino acid polymorphisms (SAPs) in hair shaft keratin proteins that result from non-synonymous single nucleotide polymorphisms (nsSNPs) in the genome are being studied as a method of supplementing microscopic comparison of questioned and known hair evidence. Most studies, however, use large amounts of hair (on the order of hundreds of centimeters of hair shaft length), not representative of operational practice in typical forensic casework analyses. Using a recently developed method of hair shaft protein extraction, this study determines how decreasing hair shaft sample length (i.e., 2 cm to 0.12 cm) affects the identification of hair proteins. For example, in 2 cm hair shaft samples, 16 hair shaft keratin proteins, KRT31-40 and KRT80-86, were high-abundant proteins identified with ˜65% average sequence coverage and 44 peptides on average per protein. When the hair shaft samples were decreased to 0.12 cm, this method still identified 15 hair shaft keratin proteins (i.e., except for KRT40) with ˜47% average sequence coverage and 26 peptides on average per protein. This study demonstrates that even with samples as small as 0.12 cm, hair shaft keratin proteins can still be reliably identified and potentially used forensically. Additionally, using the protein extraction technique described in this study, the adequate hair shaft length required for analysis should be in the range of 0.5 cm to 2 cm. Thus, peptide sequencing for SAP identification can be compatible with forensic casework sample sizes., (Published by Elsevier B.V.)
- Published
- 2020
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22. A study of the intrinsic variability and the effect of environmental conditions on the formation of a postmortem root band.
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Damaso N, Jones KF, Carlson TL, Fleming J, Steadman DW, Jantz LM, Hauther K, Otterstatter LM, and Donfack J
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- Acetates, Aged, Aged, 80 and over, Female, Forensic Pathology, Humans, Immersion, Logistic Models, Male, Microscopy, Sodium Azide, Water, Hair pathology, Postmortem Changes
- Abstract
A postmortem root band (PMRB) is defined as "an opaque ellipsoidal band composed of a collection of parallel elongated air/gas spaces and is approximately 0.5mm above the root bulb and about 2mm below the skin surface" [1]. It is generally accepted that it can appear in the root of hairs attached to remains during decomposition [1]. This study aimed to investigate the underlying cause and mechanism of PMRB formation. This was done (i) by observing the overall frequency and the intrinsic variability in anagen hairs containing a PMRB collected across five regions of a human decedent's scalp at three time points, and (ii) by determining if PMRB-like features can be induced via immersion in in-vitro controlled environments of anagen hairs plucked from the scalp of a human decedent (ex-situ postmortem hairs) not containing a PMRB. The results of the first objective illustrated that as time since death increased, the frequency of hairs containing a PMRB across the scalp sampling regions increased and the intrinsic variability decreased. The results of the second objective demonstrated that both an aqueous environment and microbial activity are essential for the formation of PMRB-like features. This study was the first to statistically analyze the intrinsic variability of PMRB formation, as well as the first to induce PMRB-like features in roots of ex-situ postmortem hairs., (Published by Elsevier B.V.)
- Published
- 2018
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23. A Review and Conceptual Model of Factors Correlated with Postmortem Root Band Formation.
- Author
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Donfack J and Castillo HS
- Subjects
- Bacterial Physiological Phenomena, Environment, Forensic Pathology, Humans, Temperature, Hair pathology, Postmortem Changes
- Abstract
It is generally accepted within the forensic trace evidence community that a postmortem root band (PMRB) can appear in the root of hairs attached to remains during decomposition. Presently, the specific sequences of events and/or exact molecular signals that lead to the formation of a PMRB are not well understood. The published literature addressing the abiotic and biotic factors that correlate with the formation of PMRBs is reviewed and a conceptual model for the formation of PMRBs is proposed., (© 2018 American Academy of Forensic Sciences.)
- Published
- 2018
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- View/download PDF
24. Protein extraction from human anagen head hairs 1-millimeter or less in total length.
- Author
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Carlson TL, Moini M, Eckenrode BA, Allred BM, and Donfack J
- Subjects
- Adult, Chromatography, Liquid methods, Humans, Male, Proteolysis, Trypsin chemistry, Hair chemistry, Keratins, Hair-Specific analysis, Proteins analysis, Proteomics methods, Tandem Mass Spectrometry methods
- Abstract
A simple method for extracting protein from human anagen (i.e., actively growing hair stage) head hairs was developed in this study for cases of limited sample availability and/or studies of specific micro-features within a hair. The distinct feature segments of the hair from one donor were divided lengthwise (i.e., each of ∼200-400 μm) and then pooled for three individual hairs to form a total of eight composite hair samples (i.e., each of ∼1 mm or less in total length). The proteins were extracted, digested using trypsin, and characterized via nano-flow liquid chromatography tandem-mass spectrometry (nLC-MS/MS). A total of 63 proteins were identified from all eight protein samples analyzed of which 60% were keratin and keratin-associated proteins. The major hair keratins identified are consistent with previous studies using fluorescence in situ hybridization and nLC-MS/MS while requiring over 400-8000-fold less sample. The protein extraction method from micro-sized human head hairs described in this study will enable proteomic analysis of biological evidence for cases of limited sample availability and will complement hair research. For example, research seeking to develop alternative non-DNA based techniques for comparing questioned to known hairs, and understanding the biochemistry of hair decomposition.
- Published
- 2018
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- View/download PDF
25. Microscopical characterization of known postmortem root bands using light and scanning electron microscopy.
- Author
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Hietpas J, Buscaglia J, Richard AH, Shaw S, Castillo HS, and Donfack J
- Subjects
- Forensic Pathology, Hair anatomy & histology, Humans, Hair Follicle ultrastructure, Microscopy, Microscopy, Electron, Scanning, Postmortem Changes
- Abstract
A postmortem root band (PMRB) is a distinct microscopic feature that is postulated to occur in hair remaining in the follicle during the postmortem interval [1] (Petraco et al., 1998). The scientific validity of this premise has been highlighted in two recent high-profile criminal cases involving PMRBs [2,3] (State of Florida v. Casey Marie Anthony, 2008; People v. Kogut, 2005). To better understand the fundamental aspects of postmortem root banding, the microscopical properties of known PMRBs
1 were characterized by light microscopy, and scanning electron microscope (SEM) imaging of microtomed sections of hairs showing root banding. The results from this study show that the appearance of the PMRB may be due to the degradation of the chemically labile, non-keratin intermacrofibrillar matrix (IMM) in the pre-keratin/keratogenous region of anagen hairs. In addition, this degradation is confined to the cortex of the hair, with no apparent damage to the layers of the cuticle. These results could provide valuable information for determining the mechanism of band formation, as well as identify a set of microscopic features that could be used to distinguish hairs with known PMRBs from similarly looking environmentally degraded hairs., (Published by Elsevier Ireland Ltd.)- Published
- 2016
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26. Mass spectrometry-based cDNA profiling as a potential tool for human body fluid identification.
- Author
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Donfack J and Wiley A
- Subjects
- DNA Primers, Humans, Body Fluids, DNA, Complementary genetics, Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization methods
- Abstract
Several mRNA markers have been exhaustively evaluated for the identification of human venous blood, saliva, and semen in forensic genetics. As new candidate human body fluid specific markers are discovered, evaluated, and reported in the scientific literature, there is an increasing trend toward determining the ideal markers for cDNA profiling of body fluids of forensic interest. However, it has not been determined which molecular genetics-based technique(s) should be utilized to assess the performance of these markers. In recent years, only a few confirmatory, mRNA/cDNA-based methods have been evaluated for applications in body fluid identification. The most frequently described methods tested to date include quantitative polymerase chain reaction (qPCR) and capillary electrophoresis (CE). However these methods, in particular qPCR, often favor narrow multiplex PCR due to the availability of a limited number of fluorescent dyes/tags. In an attempt to address this technological constraint, this study explored matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) for human body fluid identification via cDNA profiling of venous blood, saliva, and semen. Using cDNA samples at 20pg input phosphoglycerate kinase 1 (PGK1) amounts, body fluid specific markers for the candidate genes were amplified in their corresponding body fluid (i.e., venous blood, saliva, or semen) and absent in the remaining two (100% specificity). The results of this study provide an initial indication that MALDI-TOF MS is a potential fluorescent dye-free alternative method for body fluid identification in forensic casework. However, the inherent issues of low amounts of mRNA, and the damage caused to mRNA by environmental exposures, extraction processes, and storage conditions are important factors that significantly hinder the implementation of cDNA profiling into forensic casework., (Published by Elsevier Ireland Ltd.)
- Published
- 2015
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27. Evaluation of DNAstable for DNA storage at ambient temperature.
- Author
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Howlett SE, Castillo HS, Gioeni LJ, Robertson JM, and Donfack J
- Subjects
- Base Sequence, DNA genetics, DNA Primers, Real-Time Polymerase Chain Reaction, DNA chemistry, Temperature
- Abstract
Preserving DNA is important for validation of prospective and retrospective analyses, requiring many expensive types of equipment (e.g., freezers and back-up generators) and energy. While freezing is the most common method for storing extracted DNA evidence or well-characterized DNA samples for validation studies, DNAstable (Biomatrica), a commercially available medium for room temperature storage of DNA extracts was evaluated in this study. Two groups of samples consisting of different DNA quantities were investigated, one ranging from 20 to 400 ng (group 1) and the other one ranging from 1.4 to 20 ng (group 2). The DNA samples with and without DNAstable were stored at four different temperatures [∼25 °C (room temperature), -20 °C, 37 °C or 50 °C]. DNA degradation over several months was monitored by SYBR Green-based qPCR assays and by PCR amplification of the core CODIS STR markers for group 1 and 2 DNA samples, respectively. For the time points tested in this study (up to 365 days), the findings indicate that the -20 °C controls and the DNAstable protected samples at room temperature provided similar DNA recoveries that were higher compared to the unprotected controls kept at RT, 37 °C or 50 °C. These results suggest that DNAstable can protect DNA samples with effectiveness similar to that of the traditional -20 °C freezing method. In addition, extrapolations from accelerated aging experiments conducted at high temperatures support that DNAstable is an effective technology for preserving purified DNA at room temperature with a larger protective impact on DNA samples of low quantity (<20 ng)., (Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.)
- Published
- 2014
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28. First all-in-one diagnostic tool for DNA intelligence: genome-wide inference of biogeographic ancestry, appearance, relatedness, and sex with the Identitas v1 Forensic Chip.
- Author
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Keating B, Bansal AT, Walsh S, Millman J, Newman J, Kidd K, Budowle B, Eisenberg A, Donfack J, Gasparini P, Budimlija Z, Henders AK, Chandrupatla H, Duffy DL, Gordon SD, Hysi P, Liu F, Medland SE, Rubin L, Martin NG, Spector TD, and Kayser M
- Subjects
- Eye Color, Feasibility Studies, Female, Hair Color, Humans, Logistic Models, Male, Multivariate Analysis, Phenotype, Polymorphism, Single Nucleotide, Racial Groups, Sensitivity and Specificity, Sex, Single-Blind Method, DNA Fingerprinting methods, Forensic Genetics methods, Genome-Wide Association Study
- Abstract
When a forensic DNA sample cannot be associated directly with a previously genotyped reference sample by standard short tandem repeat profiling, the investigation required for identifying perpetrators, victims, or missing persons can be both costly and time consuming. Here, we describe the outcome of a collaborative study using the Identitas Version 1 (v1) Forensic Chip, the first commercially available all-in-one tool dedicated to the concept of developing intelligence leads based on DNA. The chip allows parallel interrogation of 201,173 genome-wide autosomal, X-chromosomal, Y-chromosomal, and mitochondrial single nucleotide polymorphisms for inference of biogeographic ancestry, appearance, relatedness, and sex. The first assessment of the chip's performance was carried out on 3,196 blinded DNA samples of varying quantities and qualities, covering a wide range of biogeographic origin and eye/hair coloration as well as variation in relatedness and sex. Overall, 95 % of the samples (N = 3,034) passed quality checks with an overall genotype call rate >90 % on variable numbers of available recorded trait information. Predictions of sex, direct match, and first to third degree relatedness were highly accurate. Chip-based predictions of biparental continental ancestry were on average ~94 % correct (further support provided by separately inferred patrilineal and matrilineal ancestry). Predictions of eye color were 85 % correct for brown and 70 % correct for blue eyes, and predictions of hair color were 72 % for brown, 63 % for blond, 58 % for black, and 48 % for red hair. From the 5 % of samples (N = 162) with <90 % call rate, 56 % yielded correct continental ancestry predictions while 7 % yielded sufficient genotypes to allow hair and eye color prediction. Our results demonstrate that the Identitas v1 Forensic Chip holds great promise for a wide range of applications including criminal investigations, missing person investigations, and for national security purposes.
- Published
- 2013
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29. Evaluation of mRNA marker specificity for the identification of five human body fluids by capillary electrophoresis.
- Author
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Richard ML, Harper KA, Craig RL, Onorato AJ, Robertson JM, and Donfack J
- Subjects
- 5-Aminolevulinate Synthetase genetics, DNA Primers, Electrophoresis, Capillary, Female, Gene Expression Profiling, Genetic Markers, Histatins genetics, Humans, Male, Matrix Metalloproteinase 7 genetics, Mucin-4 genetics, Polymerase Chain Reaction, Protamines genetics, Salivary Proteins and Peptides genetics, Transglutaminases genetics, Cervix Mucus metabolism, Menstruation blood, RNA, Messenger metabolism, Saliva metabolism, Semen metabolism
- Abstract
The identification of forensically relevant human body fluids through messenger RNA (mRNA) profiling is of interest to the forensic community. Previous studies have proposed several tissue-specific mRNA markers to achieve this goal. Seven markers for the following genes were selected for evaluation in this study: histatin 3 (HTN3) and statherin (STATH) for saliva, mucin 4 (MUC4) for vaginal secretions, matrix metalloproteinase 7 (MMP7) for menstrual blood, delta-aminolevulinate synthase 2 (ALAS2) for peripheral blood, and protamine 2 (PRM2) and transglutaminase 4 (TGM4) for semen. The expression of these markers was examined in each body fluid. All mRNA markers were present in their target body fluids. Peripheral blood and saliva showed little cross-reactivity with the selected markers. However, a high level of cross-reactivity was observed between the vaginal secretion marker MUC4 and saliva stains. Semen showed a high level of cross-reactivity with the selected markers. Co-expression of the predicted body fluid markers was detected in menstrual blood and vaginal secretion stains. The expression pattern of these mRNA markers varied through the menstrual cycle time points tested. Differences in gene expression levels and marker cross-reactivity were observed in the donors tested. Despite the presence of cross-reactivity and co-expression, each of the body fluids examined have distinct gene expression profiles, allowing for body fluid identification based on mRNA profiling., (Published by Elsevier Ireland Ltd.)
- Published
- 2012
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30. Salicylic acid-releasing polyurethane acrylate polymers as anti-biofilm urological catheter coatings.
- Author
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Nowatzki PJ, Koepsel RR, Stoodley P, Min K, Harper A, Murata H, Donfack J, Hortelano ER, Ehrlich GD, and Russell AJ
- Subjects
- Anti-Infective Agents administration & dosage, Anti-Infective Agents chemistry, Biofilms growth & development, Coated Materials, Biocompatible chemistry, Coated Materials, Biocompatible pharmacology, Equipment Failure Analysis, Materials Testing, Acrylates chemistry, Biofilms drug effects, Coated Materials, Biocompatible administration & dosage, Polyurethanes chemistry, Salicylic Acid administration & dosage, Salicylic Acid chemistry, Urinary Catheterization instrumentation
- Abstract
Biofilm-associated infections are a major complication of implanted and indwelling medical devices like urological and venous catheters. They commonly persist even in the presence of an oral or intravenous antibiotic regimen, often resulting in chronic illness. We have developed a new approach to inhibiting biofilm growth on synthetic materials through controlled release of salicylic acid from a polymeric coating. Herein we report the synthesis and testing of a ultraviolet-cured polyurethane acrylate polymer composed, in part, of salicyl acrylate, which hydrolyzes upon exposure to aqueous conditions, releasing salicylic acid while leaving the polymer backbone intact. The salicylic acid release rate was tuned by adjusting the polymer composition. Anti-biofilm performance of the coatings was assessed under several biofilm forming conditions using a novel combination of the MBEC Assay™ biofilm multi-peg growth system and bioluminescence monitoring for live cell quantification. Films of the salicylic acid-releasing polymers were found to inhibit biofilm formation, as shown by bioluminescent and GFP reporter strains of Pseudomonas aeruginosa and Escherichia coli. Urinary catheters coated on their inner lumens with the salicylic acid-releasing polymer significantly reduced biofilm formation by E. coli for up to 5 days under conditions that simulated physiological urine flow., (Copyright © 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.)
- Published
- 2012
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- View/download PDF
31. Age of child, more than HPV type, is associated with clinical course in recurrent respiratory papillomatosis.
- Author
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Buchinsky FJ, Donfack J, Derkay CS, Choi SS, Conley SF, Myer CM 3rd, McClay JE, Campisi P, Wiatrak BJ, Sobol SE, Schweinfurth JM, Tsuji DH, Hu FZ, Rockette HE, Ehrlich GD, and Post JC
- Subjects
- Base Sequence, Biopsy, Child, DNA Primers, Human papillomavirus 11 isolation & purification, Human papillomavirus 6 isolation & purification, Humans, Papillomavirus Infections virology, Polymerase Chain Reaction, Respiratory Tract Infections virology, Age Factors, Papillomavirus Infections pathology, Respiratory Tract Infections pathology
- Abstract
Background: RRP is a devastating disease in which papillomas in the airway cause hoarseness and breathing difficulty. The disease is caused by human papillomavirus (HPV) 6 or 11 and is very variable. Patients undergo multiple surgeries to maintain a patent airway and in order to communicate vocally. Several small studies have been published in which most have noted that HPV 11 is associated with a more aggressive course., Methodology/principal Findings: Papilloma biopsies were taken from patients undergoing surgical treatment of RRP and were subjected to HPV typing. 118 patients with juvenile-onset RRP with at least 1 year of clinical data and infected with a single HPV type were analyzed. HPV 11 was encountered in 40% of the patients. By our definition, most of the patients in the sample (81%) had run an aggressive course. The odds of a patient with HPV 11 running an aggressive course were 3.9 times higher than that of patients with HPV 6 (Fisher's exact p = 0.017). However, clinical course was more closely associated with age of the patient (at diagnosis and at the time of the current surgery) than with HPV type. Patients with HPV 11 were diagnosed at a younger age (2.4y) than were those with HPV 6 (3.4y) (p = 0.014). Both by multiple linear regression and by multiple logistic regression HPV type was only weakly associated with metrics of disease course when simultaneously accounting for age. CONCLUSIONS/SIGNIFICANCE ABSTRACT: The course of RRP is variable and a quarter of the variability can be accounted for by the age of the patient. HPV 11 is more closely associated with a younger age at diagnosis than it is associated with an aggressive clinical course. These data suggest that there are factors other than HPV type and age of the patient that determine disease course.
- Published
- 2008
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32. Human susceptibility to viral infection: the search for HIV-protective alleles among Africans by means of genome-wide studies.
- Author
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Donfack J, Buchinsky FJ, Post JC, and Ehrlich GD
- Subjects
- Chemokines genetics, Humans, Immunity, Cellular genetics, Quantitative Trait Loci, Receptors, Chemokine genetics, Black People genetics, Genes, MHC Class II genetics, Genetic Predisposition to Disease, HIV Infections genetics, HIV-1, Immunity, Innate genetics
- Abstract
Human immunodeficiency virus (HIV) infection represents a major global health problem, with HIV now recognized as the fourth leading cause of death on a worldwide basis. One approach to developing effective anti- HIV interventions is to identify and understand the molecular mechanisms by which natural genetic variations provide protection from infection or disease progression. This approach can be used to identify human gene alleles that confer resistance or increased susceptibility to HIV infection. To date, however, this approach has been underutilized in the African population and all HIV-resistance alleles that have been described have been identified by evaluating candidate genes. This limited approach is based upon a researcher's assumption that those genes that will provide the host with a benefit can be predicted, a priori, but it does not provide for a large scale systematic screen of all possible candidate genes. Nonetheless, this method has met with some success in identifying HIV-resistance genes, mostly among the white population. The lack of a comprehensive genetic approach, both in terms of the populations studied and the percentage of the genome investigated, likely explains why all of the HIV-restriction alleles identified to date fall within two gene families, and why no resistance genes have been identified among black Africans. It is likely, as with any complex trait, that most protective alleles will provide only partial HIV resistance. Thus, HIV resistance in most persons likely arises through a QTL (quantitative trait loci) mechanism meaning that protection is a polygenic trait. This feature coupled with interpopulation genetic heterogeneity makes the candidate gene mapping approach a daunting task. A comprehensive genome-wide case-control allelic association study in the African population will maximize our chances of identifying new targets for the development of new therapeutics that have the promise of benefiting all persons infected with HIV.
- Published
- 2006
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- View/download PDF
33. Unique challenges of obtaining regulatory approval for a multicenter protocol to study the genetics of RRP and suggested remedies.
- Author
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Sherwood ML, Buchinsky FJ, Quigley MR, Donfack J, Choi SS, Conley SF, Derkay CS, Myer CM 3rd, Ehrlich GD, and Post JC
- Subjects
- Documentation, Hospitals, Pediatric, Humans, Neoplasm Recurrence, Local, Papilloma, Respiratory Tract Neoplasms genetics, United States, Clinical Protocols standards, Ethics Committees, Research legislation & jurisprudence, Ethics Committees, Research organization & administration, Multicenter Studies as Topic legislation & jurisprudence, Multicenter Studies as Topic standards
- Abstract
Objective: Investigations that seek to generalize findings or to understand uncommon diseases must be conducted at multiple centers. This study describes the process of obtaining regulatory approval for a minimal risk genetic study in a multi-center setting as undertaken by the Recurrent Respiratory Papillomatosis (RRP) Task Force., Study Design and Setting: Sequential cohort of American children's hospitals. A single protocol was submitted to each Institutional Review Board (IRB)., Results: Documentation was prepared for 14 IRBs over 2.5 years. The median time between enlistment and approval at the first 8 sites was 15 months. Institutions varied considerably in their requirements and in the issues that were raised. Protocols were submitted sequentially and accumulated experience was used in the preparation of applications to subsequent IRBs. Nevertheless, there was no correlation between the accumulated experience and the number of issues that were raised., Conclusion: Despite uniform federal standards, all local IRBs required unique and individualized submissions. For multicenter studies, investigators should seriously consider the establishment of cooperative authorization agreements. On a simpler level, a standardized format for applications needs to be adopted nationwide., Ebm Rating: B-3b.
- Published
- 2006
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34. Four mutations in Epidermodysplasia verruciformis 1 (EVER1) gene are not contributors to susceptibility in RRP.
- Author
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Donfack J, Buchinsky FJ, Derkay CS, Steinberg BM, Choi SS, Conley SF, Meyer CM 3rd, McClay JE, Campisi P, Hu FZ, Preston RA, Abramson AL, Ehrlich GD, and Post JC
- Subjects
- Female, Genetic Predisposition to Disease, Genotype, Humans, Male, Neoplasm Recurrence, Local genetics, Neoplasm Recurrence, Local virology, Papilloma virology, Papillomavirus Infections complications, Phenotype, Point Mutation, Respiratory Tract Neoplasms virology, Severity of Illness Index, Membrane Proteins genetics, Papilloma genetics, Papillomaviridae, Papillomavirus Infections genetics, Respiratory Tract Neoplasms genetics
- Abstract
Objective: Epidermodysplasia verruciformis is a skin disease characterized by abnormal susceptibility to human papilloma viruses. Recently four mutations in the Epidermodysplasia verruciformis 1 gene (EVER1, also known as TMC6) have been associated with the disease. Because of the phenotypic similarity between Epidermodysplasia verruciformis and recurrent respiratory papillomatosis, we decided to investigate whether any of these mutations accounts for the susceptibility to human papilloma viruses in subjects with recurrent respiratory papillomatosis (RRP)., Methods: Allele-specific PCR and restriction fragment length polymorphisms (RFLPs) were employed for genotyping a cohort of 101 patients with recurrent respiratory papillomatosis., Results: None of these four mutations were found in the studied subjects., Conclusion: The absence of these mutations in RRP patients might indicate that EVER 1 alleles are not associated with susceptibility to RRP, or that other, as yet unidentified, mutations in the Epidermodysplasia verruciformis 1 gene, might account for the susceptibility to RRP.
- Published
- 2006
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35. Variation in conserved non-coding sequences on chromosome 5q and susceptibility to asthma and atopy.
- Author
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Donfack J, Schneider DH, Tan Z, Kurz T, Dubchak I, Frazer KA, and Ober C
- Subjects
- Conserved Sequence genetics, Genetic Predisposition to Disease genetics, Genetic Testing methods, Genetic Variation genetics, Heterozygote, Humans, Pedigree, Polymorphism, Single Nucleotide genetics, Sequence Analysis, DNA, Asthma genetics, Chromosomes, Human, Pair 5 genetics, Interleukin-13 genetics, Interleukin-4 genetics, Respiratory Hypersensitivity genetics
- Abstract
Background: Evolutionarily conserved sequences likely have biological function., Methods: To determine whether variation in conserved sequences in non-coding DNA contributes to risk for human disease, we studied six conserved non-coding elements in the Th2 cytokine cluster on human chromosome 5q31 in a large Hutterite pedigree and in samples of outbred European American and African American asthma cases and controls., Results: Among six conserved non-coding elements (> 100 bp, > 70% identity; human-mouse comparison), we identified one single nucleotide polymorphism (SNP) in each of two conserved elements and six SNPs in the flanking regions of three conserved elements. We genotyped our samples for four of these SNPs and an additional three SNPs each in the IL13 and IL4 genes. While there was only modest evidence for association with single SNPs in the Hutterite and European American samples (P < 0.05), there were highly significant associations in European Americans between asthma and haplotypes comprised of SNPs in the IL4 gene (P < 0.001), including a SNP in a conserved non-coding element. Furthermore, variation in the IL13 gene was strongly associated with total IgE (P = 0.00022) and allergic sensitization to mold allergens (P = 0.00076) in the Hutterites, and more modestly associated with sensitization to molds in the European Americans and African Americans (P < 0.01)., Conclusion: These results indicate that there is overall little variation in the conserved non-coding elements on 5q31, but variation in IL4 and IL13, including possibly one SNP in a conserved element, influence asthma and atopic phenotypes in diverse populations.
- Published
- 2005
- Full Text
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36. Fine mapping and positional candidate studies identify HLA-G as an asthma susceptibility gene on chromosome 6p21.
- Author
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Nicolae D, Cox NJ, Lester LA, Schneider D, Tan Z, Billstrand C, Kuldanek S, Donfack J, Kogut P, Patel NM, Goodenbour J, Howard T, Wolf R, Koppelman GH, White SR, Parry R, Postma DS, Meyers D, Bleecker ER, Hunt JS, Solway J, and Ober C
- Subjects
- Adult, Bronchial Hyperreactivity genetics, Child, Female, Genetic Testing, HLA-G Antigens, Humans, Male, Phenotype, Asthma genetics, Chromosome Mapping, Chromosomes, Human, Pair 6 genetics, Genetic Predisposition to Disease, HLA Antigens genetics, Histocompatibility Antigens Class I genetics
- Abstract
Asthma affects nearly 14 million people worldwide and has been steadily increasing in frequency for the past 50 years. Although environmental factors clearly influence the onset, progression, and severity of this disease, family and twin studies indicate that genetic variation also influences susceptibility. Linkage of asthma and related phenotypes to chromosome 6p21 has been reported in seven genome screens, making it the most replicated region of the genome. However, because many genes with individually small effects are likely to contribute to risk, identification of asthma susceptibility loci has been challenging. In this study, we present evidence from four independent samples in support of HLA-G as a novel asthma and bronchial hyperresponsiveness susceptibility gene in the human leukocyte antigen region on chromosome 6p21, and we speculate that this gene might contribute to risk for other inflammatory diseases that show linkage to this region.
- Published
- 2005
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37. Fine mapping a gene for pediatric gastroesophageal reflux on human chromosome 13q14.
- Author
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Hu FZ, Donfack J, Ahmed A, Dopico R, Johnson S, Post JC, Ehrlich GD, and Preston RA
- Subjects
- Adult, Base Sequence, Case-Control Studies, Child, DNA Primers, Databases, Nucleic Acid, Expressed Sequence Tags, Female, Gene Frequency, Humans, Male, Molecular Sequence Data, Mutation genetics, Sequence Analysis, DNA, Chromosome Mapping, Chromosomes, Human, Pair 13 genetics, Gastroesophageal Reflux genetics, Polymorphism, Single Nucleotide genetics
- Abstract
We previously mapped a gene for severe pediatric gastroesophageal reflux disease ( GERD1) to a 9-cM interval on chromosome 13q14. In this report, we present the results of DNA sequencing and allelic association analyses that were done in an attempt to clone the GERD1 gene. Using a candidate transcript approach, we screened affected individuals for mutations in all transcribed regions of all genes, putative genes, and ESTs identified within the 6.2-Mb GERD1 locus based on alignments with the GenBank cDNA databases. From a total of 50 identifiable genes and 99 EST clusters in the GERD1 locus, we identified 163 polymorphisms (143 SNPs and 20 INDELs) in 21 genes and 37 ESTs. The patterns of inheritance and/or the high population frequencies of all polymorphic alleles identified in this study argued against causative relationships between any of the alleles and the GERD phenotype. Using a subset of 51 SNPs distributed throughout the GERD1 locus, we performed case-control and family (TDT) allelic association analyses on two sets of samples. The case-control study was performed with 73 GERD cases and 93 controls, and the family study was performed using 22 small families. SNP 160 (position 38,925,329 Mb, UCSChg15 map) gave a significant P value prior to multiple test correction in both the case control and family studies, while SNP168 (at 40,442,903 Mb) showed significant association after multiple test correction in the case-control sample, but was uninformative in the family sample. The results suggest that the GERD1 gene might be located near SNP160 or SNP168.
- Published
- 2004
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38. Familial juvenile autoimmune hypothyroidism, pituitary enlargement, obesity, and insulin resistance.
- Author
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Reutrakul S, Hathout EH, Janner D, Hara M, Donfack J, Bass J, and Refetoff S
- Subjects
- Autoimmune Diseases genetics, Autoimmune Diseases immunology, Child, Female, Hormones blood, Humans, Hypothyroidism immunology, Leptin blood, Magnetic Resonance Imaging, Male, Pedigree, Pituitary Diseases genetics, Pituitary Diseases immunology, Hypothyroidism genetics, Insulin Resistance genetics, Obesity genetics
- Abstract
The proband, a 9-year-old Hispanic female, presented with hair loss, strabismus, and weight gain. On magnetic resonance imaging (MRI) she was found to have severe primary hypothyroidism and a large pituitary mass. In addition, acanthosis nigricans, obesity, and hyperinsulinism were observed. Findings were similar in three of four siblings. Thyroid peroxidase antibodies were detected in the father and three of four siblings. Although all family members were obese, and hyperinsulinemia with high proinsulin and C-peptide was found in all except one sibling, only the mother and one child had overt type 2 diabetes mellitus. Because of the unusual association of autoimmune thyroid disease, insulin resistance and obesity rather than insulin deficiency, we searched for possible genetic abnormalities. The HLA haplotypes did not cosegregate with autoimmune thyroid disease or insulin resistance. Mutational analysis of known obesity genes was done. Leptin was not deficient, and sequencing of the proband's DNA showed no mutations in the perixisome proliferator activated receptor (PPAR)-gamma, PPAR-gamma(2), PPAR-alpha or melanocortin 4 receptor genes. Maternally inherited diabetes and deafness was ruled out since no mutations were found in mitochondria DNA. Insulin receptor antibodies were not detected. In conclusion, the remarkably high incidence of childhood autoimmune hypothyroidism, pituitary enlargement, insulin resistance and obesity in this family is not linked to known HLA types or known gene defects.
- Published
- 2004
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39. Multicenter initiative seeking critical genes in respiratory papillomatosis.
- Author
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Buchinsky FJ, Derkay CS, Leal SM, Donfack J, Ehrlich GD, and Post JC
- Subjects
- Child, Female, Genetic Markers, Government Programs, Humans, Infectious Disease Transmission, Vertical, Male, Polymorphism, Single Nucleotide, United States, Genetic Predisposition to Disease, Papilloma genetics, Respiratory Tract Infections genetics
- Abstract
Objectives: To determine the host genes that govern susceptibility to recurrent respiratory papillomatosis (RRP). RRP is caused by human papillomavirus (HPV) 6 and 11. Millions of babies are exposed during the birthing process, but relatively few develop the disease and the aggressiveness of the course is highly variable. Genetically encoded host susceptibility is postulated. Determining the host genes that govern susceptibility will enhance our understanding not only of RRP but also of host-viral interaction in general., Study Design: A genome-wide association study on familial triads consisting of an RRP-affected child and his or her parents. Using the HapMap data from the human genome project, we will identify those alleles that are over-transmitted by the parents to their affected offspring as compared to those alleles that are under-transmitted., Methods: Approximately 400 patients and their parents will be recruited through a collaboration between the Center for Genomic Sciences and the RRP Task Force. DNA will be extracted from blood specimens and viral typing will be performed on biopsy specimens. Patients will be genotyped using single nucleotide polymorphism (SNP) markers and compared to their respective parents' genotype using the transmission disequilibrium test. Both a genome scan and a candidate gene approach will be utilized. RESULTS Institutional Review Board authorization has been obtained at three hospitals and the process is underway at 18 more. Patient and parent recruitment has begun. Specimens have been forwarded to Pittsburgh, Pennsylvania, where the DNA has been extracted and is being stored., Conclusions: A novel approach combining a nationwide patient resource and the mapping power of the sub-centimorgan human haplotype map has been developed to elucidate the biological mechanisms of RRP by determining the genetically encoded susceptibilities of host-virus interaction.
- Published
- 2004
- Full Text
- View/download PDF
40. Sequence variation in the promoter region of the cholinergic receptor muscarinic 3 gene and asthma and atopy.
- Author
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Donfack J, Kogut P, Forsythe S, Solway J, and Ober C
- Subjects
- Allergens immunology, Animals, Base Sequence genetics, Cockroaches immunology, Gene Frequency, Haplotypes, Humans, Hypersensitivity diagnosis, Hypersensitivity immunology, Pedigree, Polymorphism, Genetic, Polymorphism, Single Nucleotide, Receptor, Muscarinic M3, Reference Values, Skin Tests, Tandem Repeat Sequences, Asthma genetics, Genetic Variation, Hypersensitivity genetics, Promoter Regions, Genetic genetics, Receptors, Muscarinic genetics
- Abstract
Background: Muscarinic acetylcholine receptors are members of the superfamily of G protein-coupled, 7 transmembrane- spanning proteins. They are important in the development of airway hyperresponsiveness. In the lung the M3 receptor, encoded by the cholinergic receptor muscarinic 3 gene, is present in airway smooth muscle and mediates smooth muscle contraction., Objective: We considered the cholinergic receptor muscarinic 3 gene as a possible candidate gene for bronchial asthma and initiated studies to identify polymorphisms in the promoter region., Method: We identified 4 single-nucleotide polymorphisms (-708A/G, -627G/C, -513C/A, and -492C/T) and 2 short tandem repeat polymorphisms, a tetranucleotide (CTTT)12-20 and a dinucleotide (GT)6-19 repeat., Results: None of the identified single nucleotide polymorphisms were significantly more frequent in asthmatic patients (n = 76) compared with in healthy control subjects (n = 81). Furthermore, there was no evidence for nonrandom transmission of short tandem repeat polymorphism haplotypes to individuals with asthma or bronchial hyperresponsiveness (P >.50) in a large Hutterite pedigree. However, there was significant nonrandom transmission of haplotypes to individuals with skin test reactivity to cockroach allergens (global transmission disequilibrium test: chi2 = 38.55, P =.013)., Conclusions: These results suggest a possible role for this gene in atopic disorders.
- Published
- 2003
- Full Text
- View/download PDF
41. HLA-DRB1*01 alleles are associated with sensitization to cockroach allergens.
- Author
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Donfack J, Tsalenko A, Hoki DM, Parry R, Solway J, Lester LA, and Ober C
- Subjects
- Adolescent, Adult, Alleles, Allergens immunology, Animals, Black People genetics, Child, Child, Preschool, HLA-DRB1 Chains, Haplotypes, Humans, Immunization, White People genetics, Black or African American, Cockroaches immunology, HLA-DR Antigens genetics, Insect Proteins immunology
- Abstract
Background: Sensitization to cockroach allergens is an important epidemiologic risk factor for asthma, particularly among African Americans living in urban environments. A recent genome screen in the Hutterites, a white founder population, identified a linkage between an HLA-linked marker and sensitization to cockroach allergens., Objective: Our purpose was to determine whether alleles at one or more HLA loci are associated with sensitization to cockroach allergens in ethnically diverse populations., Methods: Alleles at 14 HLA region loci were studied in the Hutterites. On the basis of these results, selected loci were examined in 54 African Americans with cockroach sensitization (cases) and 65 African Americans without cockroach sensitization (controls). Sensitivity to cockroach allergens was assessed in both samples by skin prick test to purified cockroach allergens (Periplaneta americana and Blatella germanica)., Results: Significant associations between cockroach allergies and DRB1*0101 (P(corrected) =.0066), DQA1*0101 (P(corrected) =.0012), and DQB1*0501 (P(corrected) =.00096) were detected in the Hutterites. In the African American sample, the most significant association was with the DRB1*0102 allele (P(corrected) =.0088, odds ratio 16.4, 95% confidence interval 2.0, 131). The DRB1*0101 allele was infrequent in the African American sample (frequency 0.06) and the DRB1*0102 allele was absent in the Hutterites. DRB1*0101 and DRB1*0102 are closely related alleles that differ from nearly all other DRB1 alleles at 3 amino acids in the 1 peptide binding domain of the HLA-DR molecule., Conclusions: The DRB1*0101 allele in the Hutterites and the DRB1*0102 allele in African Americans confer risk for cockroach sensitization. Elucidating this interaction at the molecular level may allow for more targeted treatment and prevention of atopic asthma in inner-city populations.
- Published
- 2000
- Full Text
- View/download PDF
42. [Variations under genetic control of onchocerca infection as a function of clinical profile in the endemic center of Cameroon].
- Author
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Donfack J, Ngu JL, Lando G, Zimmerman PA, Nutman J, and Same-Ekobo A
- Subjects
- Alleles, Cameroon epidemiology, DNA analysis, Endemic Diseases, HLA-DQ Antigens genetics, HLA-DQ alpha-Chains, HLA-DQ beta-Chains, Humans, Onchocerciasis epidemiology, Histocompatibility Antigens Class II genetics, Onchocerciasis genetics, Onchocerciasis immunology
- Abstract
Onchocerciasis, also known as "river blindness", presents a plenum of clinical manifestations which vary from one individual to another, and from one area to another. This large spectrum of clinical manifestations of the disease is an indication of the complexity of the pathogenesis of onchocerciasis and suggests that many interacting factors might influence the clinical features of the disease. The present study has focused on the heterogenicity of the host immune response as a plausible explanation for differences in clinical manifestations of the infection. Host genetic factors, namely HLA genes, might play an important role in determining the nature of the immune response mounted against the parasite Onchocerca volvulus, and thus the development of different manifestations of the infection. Genetic diversity of onchocerciasis was assessed in different endemic foci in Cameroon. In order to investigate the possibility that the Major Histocompatibility Complex (MHC) genes might be associated with the different clinical types of onchocerciasis, 146 subjects living in three endemic areas of Cameroon were studied. They were classified in four groups: A (asymptomatic subjects), P (putatively immune subjects) L (patients with localised disease) and G (patients with generalised disease). The four groups differed in the distribution of HLA class II alleles as determined by Direct Heteroduplex Analysis. On the one hand, allele HLA-DQA1*0501 appeared to be associated with protection against severe onchocerciasis; on the other, allele HLA-DQB1*0201 might play an important role in the severe form of the disease.
- Published
- 1999
43. [Proteolytic activity of adult worm extracts of Onchocerca volvulus].
- Author
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Lando G, Simo G, Tatchum G, Donfack J, Djoha S, and Tume C
- Subjects
- Albumins metabolism, Animals, Collagen metabolism, Elastin metabolism, Endopeptidases analysis, Humans, Hydrogen-Ion Concentration, Molecular Weight, Protease Inhibitors pharmacology, Substrate Specificity, Endopeptidases metabolism, Onchocerca volvulus enzymology
- Abstract
Studying proteolytic activity of Onchocerca volvulus (nematode causing "river blindness") shows that it is able to digest a variety of substrates such as: azoalbumine, azocoll and elastin-orcein with specific activity of 0.28, 0.57 and 1.48 mg/hour/mg of extract respectively. These enzymes are active at various pH such as pH 5.0, 8.0 and 10.0 with highest activity at pH 8.0. The effect of specific inhibitors and activators indicates that the extract might contain serine, metallo and thyoproteases. The electrophoresis of the extract on a polyacrylamide gel copolymerized with gelatin shows many proteins with enzymatic activities with molecular weight of 16.6, 43.6, 45.7, 56.2, 60.2, 61.6 and 63.1 KD respectively. The Onchocerca volvulus worm contains proteases of various enzymatic activities: a non specific activity on protein such as on azoalbumin and specific activities on collagen and elastin. These enzymes could play an important role in the survival of parasites in human hosts.
- Published
- 1999
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