32 results on '"Yako, Y."'
Search Results
2. Genetic association studies of obesity in Africa: a systematic review
- Author
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Yako, Y. Y., Echouffo-Tcheugui, J. B., Balti, E. V., Matsha, T. E., Sobngwi, E., Erasmus, R. T., and Kengne, A. P.
- Published
- 2015
- Full Text
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3. Cytokines as biomarkers of pancreatic ductal adenocarcinoma: A systematic review
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Yako, Y., primary, Kruger, D., additional, Smith, M., additional, and Brand, M., additional
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- 2016
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4. Levels of circulating cytokines in South African pancreatic ductal adenocarcinoma patients: A preliminary report
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Yako, Y., primary, Brand, M., additional, Devar, J., additional, Lahoud, N., additional, Smith, M., additional, and Kruger, D., additional
- Published
- 2016
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5. Association of the ENPP1 rs997509 polymorphism with obesity in South African mixed ancestry learners
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Matsha, T., Fanampe, Yako, Y., Hassan, S., Hoffmann, M., Lize van der Merwe, and Erasmus, R. T.
- Abstract
Background: The Ectonucleotide Pyrophosphatase Phosphodiesterase1 (ENPP1) polymorphisms have been associated with metabolic traits. There is no data on the effect of ENPP1 in South African children or adults. Objective: To investigate the role of K121Q (rs1044498), rs997509 and rs9402349 in obesity and other components of the metabolic syndrome. Design: A case-control study. Subjects: Sixty four obese and 64 lean mixed ancestry learners. Setting: Western Cape, South Africa. Main outcome measure: The EN PP1 rs997509T allele is independently associated with obesity in children of mixed ancestry from South Africa. Results: The T allele frequency of the rs997509 differed significantly between obese and controls, p=0.0100 and increased the risk of being obese, p = 0.0238. Furthermore, the estimated effect of the T allele was an increase of 8.6 cm in waist circumference, 10.2 kg in weight and a corresponding 4.9 kg/m2 in BMI. Individuals carrying both the 121Q and the T allele of rs997509 were more associated with obesity (odds ratio = 3.85, 95% CI: 1.13 to 13.09) whilst those carrying the C allele of rs997509 in the presence of 121Q were likely to be lean with odds ratio of obesity 0.41 (95% CI: 0.19 to 0.87). Conclusion: Our findings suggest that ENPP1 polymorphisms may contribute to different metabolic characteristics, all of which are associated with insulin resistance in mixed ancestry children of South Africa. However, a larger study is required to confirm findings of this study.East African Medical Journal Vol. 87 No. 8 August 2010
- Published
- 2012
6. Knowledge, Attitudes and Beliefs about Dementia in an Urban Xhosa-Speaking Community in South Africa
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Khonje, V., primary, Milligan, C., additional, Yako, Y., additional, Mabelane, M., additional, Borochowitz, K. E., additional, and de Jager, C. A., additional
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- 2015
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7. Metabolic syndrome in 10–16-year-old learners from the Western Cape, South Africa: Comparison of the NCEP ATP III and IDF criteria
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Matsha, T., Hassan, S., Bhata, A., Yako, Y., Fanampe, B., Somers, A., Hoffmann, M., Mohammed, Z., and Erasmus, R.T.
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- 2009
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8. Rare Mutations of Peroxisome Proliferator-Activated Receptor Gamma: Frequencies and Relationship with Insulin Resistance and Diabetes Risk in the Mixed Ancestry Population from South Africa
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Vergotine, Z., primary, Kengne, A. P., additional, Erasmus, R. T., additional, Yako, Y. Y., additional, and Matsha, T. E., additional
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- 2014
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9. Negative association of MC3R variants with weight and blood pressure in Cape Town pupils aged 11 - 16 years
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Yako, Y. Y., Fanampe, B. L., Hassan, S. M., Erasmus, R. T., Lize van der Merwe, and Matsha, T. E.
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genetic structures - Abstract
BACKGROUND: Human and animal studies support the role of MC4R and MC3R in human obesity, but limited data are available on the genetic contribution to obesity in South African populations. OBJECTIVE: To screen obese-overweight South African pupils for MC3R and MC4R polymorphisms that may play a role in the development of obesity. DESIGN: A cross-sectional study screened 227 obese-overweight (115 black and 112 coloured) and 204 normal weight (94 black, 110 coloured) school pupils for the presence of MC4R and MC3R polymorphisms using a single strand conformation polymorphism, subsequent sequencing, and allele specific restriction enzyme analysis. RESULTS: Two polymorphisms were detected in the MC3R (T6K and V81I) but none in MC4R . After adjusting for age, gender and case-control status, the frequency distributions of T6K and V81I genotype and allele varied significantly between the ethnic groups. The frequency of the V81I A allele was significantly lower in coloured overweight-obesity than normal pupils. In coloured pupils, both polymorphisms were associated with obesity indices and total cholesterol. The T6K A allele was also associated with lower blood pressure. Likewise, different T6K-V81I haplotypes demonstrated negative associations with obesity indices and blood pressure. CONCLUSIONS: We demonstrated that the MC3R polymorphisms have a protective effect on metabolic traits; however, further analysis is required to confirm whether this translates to a lower incidence of metabolic syndrome in coloured populations.
10. Earthquake Preparedness for Operating Room Staff: Lessons Learned From Experiences and the Literature.
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Matsumoto Y, Kinoshita M, Tomiyama Y, and Tanaka K
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Earthquakes pose hazards to health care workers and patients in operating rooms. Proactive planning based on insights gained from past experiences is crucial for enhancing safety. Through a comprehensive literature review, we summarize challenges and lessons learned from real earthquake events to inform the development of effective safety measures in operating rooms. Additionally, we discuss the anesthesiologist's role in crisis management., Competing Interests: Conflicts of Interest, Funding: Please see DISCLOSURES at the end of this article., (Copyright © 2024 International Anesthesia Research Society.)
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- 2024
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11. Quantitative and calculated estimated blood loss in cesarean deliveries for twin and singleton pregnancies: a retrospective analysis.
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Takahashi R, Sakai Y, Kinoshita M, Matsumoto Y, Nakaji Y, and Tanaka K
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- Humans, Female, Pregnancy, Retrospective Studies, Adult, Hematocrit methods, Cesarean Section methods, Pregnancy, Twin, Blood Loss, Surgical statistics & numerical data
- Abstract
Purpose: This study retrospectively assessed blood loss during cesarean deliveries for twin and singleton pregnancies using two distinct methods, quantitative estimation measured during cesarean sections and hematocrit-based calculated estimation., Methods: We included scheduled cesarean deliveries for twin or singleton pregnancies at ≥ 34 weeks of gestation. Quantitative blood loss was recorded based on the blood volume in the graduated collector bottle and by weighing the blood-soaked textiles during cesarean sections. The blood loss was calculated using the change in hematocrit levels before and after the cesarean delivery., Results: We evaluated 403 cases including 44 twins and 359 singletons. Quantitative blood loss during cesarean section was significantly higher in twin pregnancies than that in singleton pregnancies (1117 [440] vs 698 [378] mL; p < 0.001). However, no significant differences were observed in the calculated blood loss between the two groups on the day after delivery (487 mL [692 mL] vs 507 mL [522 mL]; p = 0.861). On post-delivery days 4-5, twin pregnancies were associated with a significantly higher calculated blood loss than singleton pregnancies (725 [868] mL vs 444 [565] mL, p = 0.041). Although a significant moderate correlation between quantitative and calculated blood loss was observed in singleton pregnancies (r = 0.473, p < 0.001), no significant correlation was observed between twin pregnancies (r = 0.053, p = 0.735)., Conclusion: Quantitative blood loss measurements during cesarean section may be clinically insufficient in twin pregnancies. Incorporating blood tests and continuous assessments are warranted for enhanced blood loss evaluation, especially in twin pregnancies, owing to the risk of persistent bleeding., (© 2024. The Author(s) under exclusive licence to Japanese Society of Anesthesiologists.)
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- 2024
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12. Impact of anesthesiologist experience on neuraxial anesthesia outcomes in cesarean sections.
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Matsumoto Y, Sakai Y, Kinoshita M, Nakaji Y, Takahashi R, and Tanaka K
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- Humans, Female, Pregnancy, Retrospective Studies, Adult, Clinical Competence, Treatment Outcome, Body Mass Index, Infant, Newborn, Anesthesia, Epidural, Cesarean Section, Anesthesia, Obstetrical, Anesthesiologists
- Abstract
Background: Despite the requirement for meticulous management of cesarean anesthesia, no study has explored the impact of novice trainee anesthesiologists in this field. This study assessed challenges in neuraxial anesthesia for cesarean sections and compared outcomes between novice and senior anesthesiologists., Methods: We retrospectively analyzed 446 cesarean sections with neuraxial anesthesia. The primary objective was to evaluate the impact of anesthesiologists' experience on the time required to administer neuraxial anesthesia and whether maternal body mass index (BMI) influenced this relationship. Secondary objectives included examining maternal hemodynamic variability, operative details, and newborn outcomes relative to the anesthesiologist's experience., Results: Novice anesthesiologists required a significantly longer time to perform neuraxial anesthesia (24.9 [7.1] min vs. 18.2 [7.0] min, P<0.001) than their senior counterparts. A significant interaction was observed between anesthesiologist experience and maternal BMI on the time to administer neuraxial anesthesia (P=0.017), with a moderate correlation between BMI and administration time for novices (r=0.50, P<0.001) and only a slight correlation for seniors (r=0.17, P=0.001). Experience level did not significantly affect intraoperative hemodynamics, Apgar scores, or umbilical cord blood gas analyses., Conclusions: The effect of maternal BMI on the difficulty of performing neuraxial anesthesia in parturients can be more pronounced for novice anesthesiologists than for experienced ones. Despite requiring more time to perform neuraxial anesthesia, novice anesthesiologists do not significantly affect maternal hemodynamics or newborn distress during obstetric anesthesia, provided that they are under the supervision of experienced anesthesiologists.
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- 2024
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13. Adsorption and dissociation of hydrogen molecules over S-vacancies in a Nb-doped MoS 2 monolayer.
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Irusta Y, Morón-Navarrete G, and González C
- Abstract
Motivated by the recent interest in the hydrogen energy, we have carried out a complete study of the catalytic activity of a defective molybdenum disulfide monolayer (MoS
2 ) by means of density functional theory (DFT) calculations. The MoS2 monolayer is characterized by a nonreactive basal plane. In principle, its catalytic activity is concentrated at the edges, but an alternative way to increase such activity is obtained by creating active sites where the molecules can dissociate. These defects can be easily produced experimentally by different techniques. In our study, we have performed an atomic, energetic and electronic analysis of a hydrogen molecule adsorbed on a MoS2 monolayer. In a first step, we have found that the H2 molecule remains physisorbed over both doped-free and Nb-doped MoS2 monolayers, showing that the Nb atom does not increase the poor reactivity of the clean MoS2 layer. Interestingly, our energetic results suggest that the vacancies will prefer to be formed close to the Nb atoms in the doped monolayer, but the small energy difference would allow the formation in non-doped like sites. Theoretically, we found out the conditions for the molecular dissociation on a S vacancy. In both cases, with and without Nb, the molecule should rotate from the original perpendicular position to an almost parallel orientation jumping an energetic barrier. After that, the atoms are separated binding to the Mo atoms around the missing S atom. Our ab initio molecular dynamics simulations show that for low pressure conditions (using one single molecule in the system) the H2 prefers to desorb from the vacancy, while for larger pressures (when additional H2 molecules are added to the system) the molecule is finally dissociated on the vacancy. Our long simulations confirm the great stability of the structure with the two H atoms binding to the Mo atoms close to the vacancy. Finally, the inclusion of a third (or a fourth) H atom in the vacancy leads to the formation and desorption of a H2 molecule, leaving one (or two) atoms in the vacancy., (© 2024 IOP Publishing Ltd.)- Published
- 2024
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14. A study protocol for a cluster randomized controlled trial to test the applicability of the South African diabetes prevention program in the Eastern Cape Province of South Africa.
- Author
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Hill J, Yako Y, George C, Musarurwa H, Jordaan E, and Kengne AP
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- Adult, Humans, Ambulatory Care Facilities, Randomized Controlled Trials as Topic, Risk Factors, South Africa epidemiology, Middle Aged, Aged, Diabetes Mellitus, Type 2 epidemiology, Diabetes Mellitus, Type 2 prevention & control
- Abstract
Background: Convincing evidence supports the effectiveness of lifestyle interventions in preventing the occurrence of diabetes in high-income countries, however little is known about appropriate interventions for use in African countries, where there are higher relative increases in diabetes prevalence. The South African Diabetes Prevention Programme (SA-DPP) was initiated with the aim of preventing or delaying the occurrence of diabetes among South Africans (SAs), through interventions, targeting lifestyle changes related to diet and physical activity. The purpose of the current project is to implement and evaluate the suitability and applicability of the SA-DPP developed and tailored in urban populations in the Western Cape Province, in peri-urban populations in the Eastern Cape Province of SA., Methods: The SA-DPP, which is an cluster randomized control trial, will be implemented in adults aged 30-65 years residing in the OR Tambo district, Eastern Cape, SA. Participants will be recruited using self-selected sampling techniques and 24 clusters across peri-urban communities will be randomly allocated to participate in the lifestyle intervention, facilitated by non-professional health workers (NPHW). The diabetes risk screening will follow a two-staged approach, including the community-based screening, using the African diabetes risk score (ADRS), followed by a clinic-based risk status assessment by an oral glucose tolerance test (OGTT) to exclude unknown diabetes. The lifestyle-change objectives of the current programme relate to, 1) < 30% of total energy intake from fat; 2) < 10% of total energy intake from saturated fat; 3) > 15 g of fibre/1000 kcal; 4) > 4 h/week moderate level of physical activity; and 5) > 2% body mass index (BMI) reduction., Discussion: The SA-DPP could represent a successful model for the prevention of diabetes and potentially other lifestyle-related diseases in SA and other countries in the region that are confronted with similar challenges., Trial Registration: PACTR202205591282906., (© 2023. The Author(s).)
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- 2023
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15. Assessment of button-type jejunostomy for nutritional management after esophagectomy in 201 cases.
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Ishikawa Y, Nishikawa K, Fukushima N, Takahashi K, Hasegawa Y, Yuda M, Tanishima Y, and Ikegami T
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- Enteral Nutrition, Humans, Intubation, Gastrointestinal, Retrospective Studies, Esophagectomy adverse effects, Jejunostomy adverse effects
- Abstract
Background: Many surgeons preferably place a trans-nasal feeding tube or a feeding enterostomy for post-operative nutritional management after esophagectomy. Various types of tubes (such as nasogastric, transgastric, transduodenal, or transjejunal tubes) have been used for enteral feeding; however, the appropriate enteral feeding routes have not yet been proposed. Therefore, this study aimed to evaluate the feasibility and safety of button-type jejunostomy., Methods: We reviewed 201 patients who underwent esophagectomy with placement of a button-type jejunostomy at the Jikei University Hospital (Tokyo, Japan) between 2008 and 2019. The analyzed variables included clinicopathological characteristics, operative data, jejunostomy-related characteristics, and postoperative complications. Postoperative bodyweight loss was examined 6 months and 1 year after the operation., Results: Refractory enterocutaneous fistula and bowel obstruction occurred in 13 (6.5%) and 14 (7.0%) patients, respectively. The body mass index at button-type jejunostomy removal was significantly lower and the duration of button-type jejunostomy placement was significantly longer in patients with a refractory enterocutaneous fistula (p = 0.023 and p < 0.001, respectively). Bowel obstruction was significantly more likely to develop in patients with a non-squamous cell carcinoma (p = 0.021) and in patients who underwent open abdominal procedures (p < 0.001). After 1 year, the median bodyweight losses were 12.1% and 15.6% in patients with short and long jejunostomy placement durations (p = 0.642), respectively., Conclusion: A button-type jejunostomy is durable and allows easy self-management for maintaining the bodyweight without any adverse events. However, it is strongly recommended that the button be removed within a year to prevent refractory enterocutaneous fistula formation., (© 2021. Japan Society of Clinical Oncology.)
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- 2021
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16. Three millimeter needlescopic splenectomy using three-port technique: report of three cases.
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Matsushita K, Tagaya N, Nakajima R, Yagi M, Obana Y, Nakano Y, Suzuki J, Mizoguchi M, Yoshimura Y, Arai T, Hasegawa Y, Suzuki J, Haku K, Arai T, Kurosaki T, and Saito K
- Abstract
We report our experience with needlescopic splenectomy (NS) for the surgical treatment of idiopathic thrombocytopenic purpura using a 3-mm needlescope with three ports. One patient was male and two were females, and their mean age was 58 years. The patient was placed in the right lateral decubitus position. The first 12-mm port was introduced through the lateral margin of the left rectus abdominis muscle, and the other two 3-mm ports were inserted in the left upper quadrant. NS was performed by a standard technique under the observation of 3.3-mm needlescope. The surgical procedure was successfully completed in all the patients. The mean duration of surgery, intra-operative bleeding volume and post-operative hospital stay were 176 min, 70 ml and 4.7 days, respectively. There were no particular peri-operative complications in spite of dense adhesions or simultaneous laparoscopic procedures. Our method is safe and feasible with low morbidity and without impairing cosmetic benefits., (Published by Oxford University Press and JSCR Publishing Ltd. All rights reserved. © The Author(s) 2021.)
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- 2021
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17. The COX-2/PGE 2 pathway suppresses apical elimination of RasV12-transformed cells from epithelia.
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Sato N, Yako Y, Maruyama T, Ishikawa S, Kuromiya K, Tokuoka SM, Kita Y, and Fujita Y
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- Animals, Anticarcinogenic Agents pharmacology, Cell Line, Transformed, Cell Transformation, Neoplastic drug effects, Cell Transformation, Neoplastic genetics, Cell Transformation, Neoplastic pathology, Ceruletide, Cyclooxygenase 2 genetics, Cyclooxygenase Inhibitors pharmacology, Disease Models, Animal, Dogs, Epithelial Cells drug effects, Epithelial Cells pathology, Female, Ibuprofen pharmacology, Madin Darby Canine Kidney Cells, Male, Mice, Inbred C57BL, Mice, Transgenic, Pancreatitis chemically induced, Pancreatitis genetics, Pancreatitis pathology, Signal Transduction, Cell Transformation, Neoplastic metabolism, Cyclooxygenase 2 metabolism, Dinoprostone metabolism, Epithelial Cells enzymology, Genes, ras, Pancreatitis enzymology
- Abstract
At the initial stage of carcinogenesis, when RasV12-transformed cells are surrounded by normal epithelial cells, RasV12 cells are apically extruded from epithelia through cell competition with the surrounding normal cells. In this study, we demonstrate that expression of cyclooxygenase (COX)-2 is upregulated in normal cells surrounding RasV12-transformed cells. Addition of COX inhibitor or COX-2-knockout promotes apical extrusion of RasV12 cells. Furthermore, production of Prostaglandin (PG) E
2 , a downstream prostanoid of COX-2, is elevated in normal cells surrounding RasV12 cells, and addition of PGE2 suppresses apical extrusion of RasV12 cells. In a cell competition mouse model, expression of COX-2 is elevated in pancreatic epithelia harbouring RasV12-exressing cells, and the COX inhibitor ibuprofen promotes apical extrusion of RasV12 cells. Moreover, caerulein-induced chronic inflammation substantially suppresses apical elimination of RasV12 cells. These results indicate that intrinsically or extrinsically mediated inflammation can promote tumour initiation by diminishing cell competition between normal and transformed cells.- Published
- 2020
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18. Prognostic Factors Influencing Outcome in Unruptured Anterior Communicating Artery Aneurysm after Microsurgical Clipping.
- Author
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Kasinathan S, Yamada Y, Cheikh A, Teranishi T, Kawase T, and Kato Y
- Abstract
Anterior communicating artery (A.com. A) aneurysm projection is an important factor in determining the outcome of aneurysm clipping. The objective of this study was to analyze the outcome of A.com.A aneurysm projection and prognostic factors influencing it and comparing them with Glasgow outcome scale. A retrospective analysis of 47 patients from hospital records who have got admitted in the Banbuntanke Hotokokai Hospital, Nagoya, Japan, from 2014 to 2017, with unruptured A.com.A aneurysm and subsequently operated in the hospital. Demographic factors such as age, sex, and associated with other aneurysms and the morphological characteristics such as aneurysm size, projection, and height were analyzed with postoperative complications and Glasgow outcome scale. Totally 47 cases have been operated in which 26 (55.3%) are female and 21 (44.6%) are male, and the median age is 68 years, 7 (14.89%) patients had middle cerebral artery aneurysm along with A.com.A aneurysm and 1 had internal carotid artery-posterior communicating artery junction aneurysm. Four (8.5%) had chronic subdural hematoma and 1 (2.12%) had epilepsy, 1 (2.12%) case got reoperated, and 1 (2.12%) had hydrocephalus. Moreover, the overall complication rate is 14.89%. For six patients, motor-evoked potential monitoring was used. Forty-six patients had Glasgow outcome scale of 5 and 1 patient had Glasgow outcome scale of 4. There was no mortality in this study. Mean size of the aneurysm was 6.68 mm and the range was 2-25 mm. Mean height was 4.14 mm, 26 (56.52%) A.com.A aneurysm were anteriorly projecting, 9 (19.56%) were superiorly projecting, 8 (17.32%) were inferiorly projecting, and 3 (6.38%) were posteriorly projecting. Morphological parameters such as size, height, and projection were not only highly associated with A.com.A aneurysm rupture and also complications due to clipping of aneurysm., Competing Interests: There are no conflicts of interest.
- Published
- 2019
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19. Association of level of anastomosis and anastomotic leak after esophagectomy in anterior mediastinal reconstruction.
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Nishikawa K, Fujita T, Hasegawa Y, Tanaka Y, Matsumoto A, Mitsumori N, and Yanaga K
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- Adult, Aged, Aged, 80 and over, Anastomosis, Surgical adverse effects, Anastomotic Leak diagnostic imaging, Endoscopy methods, Esophageal Neoplasms complications, Female, Humans, Japan epidemiology, Male, Mediastinum anatomy & histology, Mediastinum diagnostic imaging, Mediastinum surgery, Middle Aged, Postoperative Complications epidemiology, Plastic Surgery Procedures adverse effects, Retrospective Studies, Risk Factors, Stomach blood supply, Stomach diagnostic imaging, Tomography, X-Ray Computed methods, Anastomotic Leak etiology, Esophageal Neoplasms surgery, Esophagectomy adverse effects, Stomach surgery
- Abstract
Aim: The purpose of this study was to investigate modifiable predisposing factors associated with anastomotic leak in the anterior mediastinal (AM) reconstruction route., Methods: We reviewed the data on 154 patients who underwent esophagectomy and gastric tube reconstruction using the AM route between 2008 and 2016. The data included computed tomography (CT) scans with sagittal reconstruction of the thoracic section. The level of the esophagogastric anastomosis (LEA) and pretracheal distance (PTD) was measured from sagittal reconstructed CT images. Vascularization of the gastric tube was evaluated by postoperative endoscopy. Variables associated with anastomotic leak were determined using univariate and multivariate analyses., Results: Anastomotic leak developed in 13 patients (8%). The cut-off level at which the anastomosis was less likely to develop a leak, as determined by Chi-square tests, was 1.5 cm for LEA and 1.3 cm for PTD. On univariate analysis, the factors that were significantly associated with the risk of anastomotic leak included diabetes, hand-sewn anastomosis, the LEA ≥ 1.5 cm, and severe mucosal degeneration. On multivariate analysis, diabetes (OR 4.7, 95% CI 1.29-17.2), LEA ≥ 1.5 cm (OR 20.1, 95% CI 3.15-128), and severe mucosal degeneration (OR 7.2, 95% CI 1.42-36.8) were found to be statistically significant independent risk factors., Conclusion: Use of the AM route to place the cervical anastomosis within 1.5 cm above the suprasternal notch might avoid excessive pressure on the gastric tube from the surrounding structures, resulting in a reduction in the risk of an anastomotic leak.
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- 2018
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20. ADAM-like Decysin-1 (ADAMDEC1) is a positive regulator of Epithelial Defense Against Cancer (EDAC) that promotes apical extrusion of RasV12-transformed cells.
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Yako Y, Hayashi T, Takeuchi Y, Ishibashi K, Kasai N, Sato N, Kuromiya K, Ishikawa S, and Fujita Y
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- ADAM Proteins deficiency, ADAM Proteins genetics, Animals, Coculture Techniques, Dogs, Filamins metabolism, Gene Expression Regulation, Gene Knockdown Techniques, Humans, Madin Darby Canine Kidney Cells, NF-kappa B metabolism, ADAM Proteins metabolism, Cell Transformation, Neoplastic, Epithelial Cells pathology
- Abstract
Recent studies have revealed that newly emerging transformed cells are often eliminated from epithelia via cell competition with the surrounding normal epithelial cells. However, it remains unknown whether and how soluble factors are involved in this cancer preventive phenomenon. By performing stable isotope labeling with amino acids in cell culture (SILAC)-based quantitative mass spectrometric analyses, we have identified ADAM-like Decysin-1 (ADAMDEC1) as a soluble protein whose expression is upregulated in the mix culture of normal and RasV12-transformed epithelial cells. Expression of ADAMDEC1 is elevated in normal epithelial cells co-cultured with RasV12 cells. Knockdown of ADAMDEC1 in the surrounding normal cells substantially suppresses apical extrusion of RasV12 cells, suggesting that ADAMDEC1 secreted by normal cells positively regulate the elimination of the neighboring transformed cells. In addition, we show that the metalloproteinase activity of ADAMDEC1 is dispensable for the regulation of apical extrusion. Furthermore, ADAMDEC1 facilitates the accumulation of filamin, a crucial regulator of Epithelial Defense Against Cancer (EDAC), in normal cells at the interface with RasV12 cells. This is the first report demonstrating that an epithelial intrinsic soluble factor is involved in cell competition in mammals.
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- 2018
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21. Cell competition with normal epithelial cells promotes apical extrusion of transformed cells through metabolic changes.
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Kon S, Ishibashi K, Katoh H, Kitamoto S, Shirai T, Tanaka S, Kajita M, Ishikawa S, Yamauchi H, Yako Y, Kamasaki T, Matsumoto T, Watanabe H, Egami R, Sasaki A, Nishikawa A, Kameda I, Maruyama T, Narumi R, Morita T, Sasaki Y, Enoki R, Honma S, Imamura H, Oshima M, Soga T, Miyazaki JI, Duchen MR, Nam JM, Onodera Y, Yoshioka S, Kikuta J, Ishii M, Imajo M, Nishida E, Fujioka Y, Ohba Y, Sato T, and Fujita Y
- Subjects
- Animals, Cell Line, Transformed, Cell Transformation, Neoplastic genetics, Cell Transformation, Neoplastic pathology, Coculture Techniques, Cytoskeletal Proteins genetics, Cytoskeletal Proteins metabolism, Dogs, Female, Genes, ras, Glucose metabolism, Glycolysis, Lactic Acid metabolism, Madin Darby Canine Kidney Cells, Male, Membrane Potential, Mitochondrial, Mice, Inbred C57BL, Mice, Transgenic, Mitochondria metabolism, Protein Kinases genetics, Protein Kinases metabolism, RNA Interference, Signal Transduction, Tissue Culture Techniques, Transfection, Cell Communication, Cell Transformation, Neoplastic metabolism, Energy Metabolism, Epithelial Cells metabolism
- Abstract
Recent studies have revealed that newly emerging transformed cells are often apically extruded from epithelial tissues. During this process, normal epithelial cells can recognize and actively eliminate transformed cells, a process called epithelial defence against cancer (EDAC). Here, we show that mitochondrial membrane potential is diminished in RasV12-transformed cells when they are surrounded by normal cells. In addition, glucose uptake is elevated, leading to higher lactate production. The mitochondrial dysfunction is driven by upregulation of pyruvate dehydrogenase kinase 4 (PDK4), which positively regulates elimination of RasV12-transformed cells. Furthermore, EDAC from the surrounding normal cells, involving filamin, drives the Warburg-effect-like metabolic alteration. Moreover, using a cell-competition mouse model, we demonstrate that PDK-mediated metabolic changes promote the elimination of RasV12-transformed cells from intestinal epithelia. These data indicate that non-cell-autonomous metabolic modulation is a crucial regulator for cell competition, shedding light on the unexplored events at the initial stage of carcinogenesis.
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- 2017
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22. Rab5-regulated endocytosis plays a crucial role in apical extrusion of transformed cells.
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Saitoh S, Maruyama T, Yako Y, Kajita M, Fujioka Y, Ohba Y, Kasai N, Sugama N, Kon S, Ishikawa S, Hayashi T, Yamazaki T, Tada M, and Fujita Y
- Subjects
- Animals, Cadherins genetics, Cadherins metabolism, Cell Adhesion, Epithelium embryology, Epithelium metabolism, Signal Transduction, Transformation, Genetic, Zebrafish embryology, Zebrafish genetics, Zebrafish Proteins genetics, rab5 GTP-Binding Proteins genetics, Endocytosis, Zebrafish metabolism, Zebrafish Proteins metabolism, rab5 GTP-Binding Proteins metabolism
- Abstract
Newly emerging transformed cells are often eliminated from epithelial tissues. Recent studies have revealed that this cancer-preventive process involves the interaction with the surrounding normal epithelial cells; however, the molecular mechanisms underlying this phenomenon remain largely unknown. In this study, using mammalian cell culture and zebrafish embryo systems, we have elucidated the functional involvement of endocytosis in the elimination of RasV12-transformed cells. First, we show that Rab5, a crucial regulator of endocytosis, is accumulated in RasV12-transformed cells that are surrounded by normal epithelial cells, which is accompanied by up-regulation of clathrin-dependent endocytosis. Addition of chlorpromazine or coexpression of a dominant-negative mutant of Rab5 suppresses apical extrusion of RasV12 cells from the epithelium. We also show in zebrafish embryos that Rab5 plays an important role in the elimination of transformed cells from the enveloping layer epithelium. In addition, Rab5-mediated endocytosis of E-cadherin is enhanced at the boundary between normal and RasV12 cells. Rab5 functions upstream of epithelial protein lost in neoplasm (EPLIN), which plays a positive role in apical extrusion of RasV12 cells by regulating protein kinase A. Furthermore, we have revealed that epithelial defense against cancer (EDAC) from normal epithelial cells substantially impacts on Rab5 accumulation in the neighboring transformed cells. This report demonstrates that Rab5-mediated endocytosis is a crucial regulator for the competitive interaction between normal and transformed epithelial cells in mammals.
- Published
- 2017
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23. EphA2 Drives the Segregation of Ras-Transformed Epithelial Cells from Normal Neighbors.
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Porazinski S, de Navascués J, Yako Y, Hill W, Jones MR, Maddison R, Fujita Y, and Hogan C
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- Animals, Cell Communication physiology, Cells, Cultured, Gene Expression Regulation, Receptor, EphA2 genetics, ras Proteins genetics, Epithelial Cells physiology, Receptor, EphA2 metabolism, ras Proteins metabolism
- Abstract
In epithelial tissues, cells expressing oncogenic Ras (hereafter RasV12 cells) are detected by normal neighbors and as a result are often extruded from the tissue [1-6]. RasV12 cells are eliminated apically, suggesting that extrusion may be a tumor-suppressive process. Extrusion depends on E-cadherin-based cell-cell adhesions and signaling to the actin-myosin cytoskeleton [2, 6]. However, the signals underlying detection of the RasV12 cell and triggering extrusion are poorly understood. Here we identify differential EphA2 signaling as the mechanism by which RasV12 cells are detected in epithelial cell sheets. Cell-cell interactions between normal cells and RasV12 cells trigger ephrin-A-EphA2 signaling, which induces a cell repulsion response in RasV12 cells. Concomitantly, RasV12 cell contractility increases in an EphA2-dependent manner. Together, these responses drive the separation of RasV12 cells from normal cells. In the absence of ephrin-A-EphA2 signals, RasV12 cells integrate with normal cells and adopt a pro-invasive morphology. We also show that Drosophila Eph (DEph) is detected in segregating clones of RasV12 cells and is functionally required to drive segregation of RasV12 cells in vivo, suggesting that our in vitro findings are conserved in evolution. We propose that expression of RasV12 in single or small clusters of cells within a healthy epithelium creates ectopic EphA2 boundaries, which drive the segregation and elimination of the transformed cell from the tissue. Thus, deregulation of Eph/ephrin would allow RasV12 cells to go undetected and expand within an epithelium., (Copyright © 2016 Elsevier Ltd. All rights reserved.)
- Published
- 2016
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24. A role of the sphingosine-1-phosphate (S1P)-S1P receptor 2 pathway in epithelial defense against cancer (EDAC).
- Author
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Yamamoto S, Yako Y, Fujioka Y, Kajita M, Kameyama T, Kon S, Ishikawa S, Ohba Y, Ohno Y, Kihara A, and Fujita Y
- Subjects
- Animals, Carcinogenesis genetics, Cell Movement, Dogs, Enzyme Activation, Epithelial Cells metabolism, Filamins metabolism, Humans, Lysophospholipids physiology, Madin Darby Canine Kidney Cells, Mutation, Missense, Neoplasms genetics, Neoplasms metabolism, Proto-Oncogene Proteins p21(ras) genetics, Pyrazoles pharmacology, Pyridines pharmacology, Receptors, Lysosphingolipid antagonists & inhibitors, Signal Transduction, Sphingosine analogs & derivatives, Sphingosine physiology, Sphingosine-1-Phosphate Receptors, rho-Associated Kinases metabolism, Carcinogenesis metabolism, Receptors, Lysosphingolipid metabolism
- Abstract
At the initial step of carcinogenesis, transformation occurs in single cells within epithelia, where the newly emerging transformed cells are surrounded by normal epithelial cells. A recent study revealed that normal epithelial cells have an ability to sense and actively eliminate the neighboring transformed cells, a process named epithelial defense against cancer (EDAC). However, the molecular mechanism of this tumor-suppressive activity is largely unknown. In this study, we investigated a role for the sphingosine-1-phosphate (S1P)-S1P receptor 2 (S1PR2) pathway in EDAC. First, we show that addition of the S1PR2 inhibitor significantly suppresses apical extrusion of RasV12-transformed cells that are surrounded by normal cells. In addition, knockdown of S1PR2 in normal cells induces the same effect, indicating that S1PR2 in the surrounding normal cells plays a positive role in the apical elimination of the transformed cells. Of importance, not endogenous S1P but exogenous S1P is involved in this process. By using FRET analyses, we demonstrate that S1PR2 mediates Rho activation in normal cells neighboring RasV12-transformed cells, thereby promoting accumulation of filamin, a crucial regulator of EDAC. Collectively these data indicate that S1P is a key extrinsic factor that affects the outcome of cell competition between normal and transformed epithelial cells., (© 2016 Yamamoto, Yako, et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).)
- Published
- 2016
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25. EPLIN is a crucial regulator for extrusion of RasV12-transformed cells.
- Author
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Ohoka A, Kajita M, Ikenouchi J, Yako Y, Kitamoto S, Kon S, Ikegawa M, Shimada T, Ishikawa S, and Fujita Y
- Subjects
- Animals, Butadienes pharmacology, Caveolae metabolism, Caveolin 1 metabolism, Cell Line, Chromones pharmacology, Contactin 1 metabolism, Cyclic AMP-Dependent Protein Kinases metabolism, Dogs, Enzyme Inhibitors pharmacology, Epithelial Cells metabolism, Extracellular Signal-Regulated MAP Kinases antagonists & inhibitors, Filamins metabolism, MAP Kinase Signaling System, Madin Darby Canine Kidney Cells, Microfilament Proteins metabolism, Morpholines pharmacology, Myosin Type II metabolism, Nitriles pharmacology, Phosphoinositide-3 Kinase Inhibitors, RNA Interference, RNA, Small Interfering, Caveolin 1 genetics, Cell Transformation, Neoplastic pathology, Epithelial Cells pathology, Microfilament Proteins genetics, Neoplasms pathology, Proto-Oncogene Proteins p21(ras) genetics
- Abstract
At the initial stage of carcinogenesis, a mutation occurs in a single cell within a normal epithelial layer. We have previously shown that RasV12-transformed cells are apically extruded from the epithelium when surrounded by normal cells. However, the molecular mechanisms underlying this phenomenon remain elusive. Here, we demonstrate that Cav-1-containing microdomains and EPLIN (also known as LIMA1) are accumulated in RasV12-transformed cells that are surrounded by normal cells. We also show that knockdown of Cav-1 or EPLIN suppresses apical extrusion of RasV12-transformed cells, suggesting their positive role in the elimination of transformed cells from epithelia. EPLIN functions upstream of Cav-1 and affects its enrichment in RasV12-transformed cells that are surrounded by normal cells. Furthermore, EPLIN regulates non-cell-autonomous activation of myosin-II and protein kinase A (PKA) in RasV12-transformed cells. In addition, EPLIN substantially affects the accumulation of filamin A, a vital player in epithelial defense against cancer (EDAC), in the neighboring normal cells, and vice versa. These results indicate that EPLIN is a crucial regulator of the interaction between normal and transformed epithelial cells., (© 2015. Published by The Company of Biologists Ltd.)
- Published
- 2015
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26. Filamin acts as a key regulator in epithelial defence against transformed cells.
- Author
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Kajita M, Sugimura K, Ohoka A, Burden J, Suganuma H, Ikegawa M, Shimada T, Kitamura T, Shindoh M, Ishikawa S, Yamamoto S, Saitoh S, Yako Y, Takahashi R, Okajima T, Kikuta J, Maijima Y, Ishii M, Tada M, and Fujita Y
- Subjects
- Animals, Cell Death, Cell Line, Transformed, Cell Transformation, Neoplastic genetics, Cell Transformation, Neoplastic metabolism, Cell Transformation, Neoplastic pathology, Dogs, Embryo, Nonmammalian, Filamins antagonists & inhibitors, Filamins metabolism, Madin Darby Canine Kidney Cells, Proto-Oncogene Proteins p21(ras) genetics, Proto-Oncogene Proteins p21(ras) metabolism, Proto-Oncogene Proteins pp60(c-src) genetics, Proto-Oncogene Proteins pp60(c-src) metabolism, RNA, Small Interfering genetics, RNA, Small Interfering metabolism, Signal Transduction, Transformation, Genetic, Vimentin antagonists & inhibitors, Vimentin metabolism, Zebrafish metabolism, rho-Associated Kinases genetics, rho-Associated Kinases metabolism, Filamins genetics, Gene Expression Regulation, Vimentin genetics, Zebrafish genetics
- Abstract
Recent studies have shown that certain types of transformed cells are extruded from an epithelial monolayer. However, it is not known whether and how neighbouring normal cells play an active role in this process. In this study, we demonstrate that filamin A and vimentin accumulate in normal cells specifically at the interface with Src- or RasV12-transformed cells. Knockdown of filamin A or vimentin in normal cells profoundly suppresses apical extrusion of the neighbouring transformed cells. In addition, we show in zebrafish embryos that filamin plays a positive role in the elimination of the transformed cells. Furthermore, the Rho/Rho kinase pathway regulates filamin accumulation and filamin acts upstream of vimentin in the apical extrusion. This is the first report demonstrating that normal epithelial cells recognize and actively eliminate neighbouring transformed cells and that filamin is a key mediator in the interaction between normal and transformed epithelial cells.
- Published
- 2014
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27. [A case of Stage IV sigmoid colon cancer that achieved long-term survival with oral anticancer drugs].
- Author
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Hasegawa Y, Iwata H, and Hatanaka M
- Subjects
- Administration, Oral, Aged, Capecitabine, Combined Modality Therapy, Deoxycytidine therapeutic use, Drug Combinations, Fluorouracil therapeutic use, Humans, Liver Neoplasms secondary, Lung Neoplasms secondary, Male, Neoplasm Staging, Oxonic Acid administration & dosage, Sigmoid Neoplasms pathology, Sigmoid Neoplasms surgery, Tegafur administration & dosage, Time Factors, Antimetabolites, Antineoplastic therapeutic use, Antineoplastic Combined Chemotherapy Protocols therapeutic use, Deoxycytidine analogs & derivatives, Fluorouracil analogs & derivatives, Liver Neoplasms drug therapy, Lung Neoplasms drug therapy, Sigmoid Neoplasms drug therapy
- Abstract
An 80-year-old man presenting with abdominal distension was admitted to our hospital. He was diagnosed with sigmoid cancer with multiple liver and lung metastases. We first performed a sigmoidectomy to avoid obstruction, and then initiated chemotherapy with S-1(120mg/day). The tumor showed a complete clinical response after 10 courses, but we had to change the regimen after 18 courses because of growth of the lung metastases. After 10 courses of capecitabine(4,200mg/ day)treatment, we again observed growth of the lung metastases; a new nodule, which was also considered to be a metastasis, appeared on the abdominal wall. We then decided to administer mFOLFOX6(5-fluorouracil+Leucovorin+oxaliplatin) after the patient had received oral anticancer drugs for 3 years 4 month. In conclusion, oral chemotherapy drugs may prevent tumor growth over a long period and improve quality of life(QOL)in elderly patients with Stage IV colon cancer.
- Published
- 2014
28. Three-year's changes in glucose tolerance status in the Bellville South cohort: rates and phenotypes associated with progression.
- Author
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Matsha TE, Soita DJ, Hassan MS, Hon GM, Yako YY, Kengne AP, and Erasmus RT
- Subjects
- Female, Glucose Intolerance epidemiology, Humans, Metabolic Syndrome epidemiology, Middle Aged, Risk Factors, South Africa epidemiology, Diabetes Mellitus epidemiology
- Abstract
Aims: To determine the phenotypes associated with progression to type 2 diabetes or worsening in glucose tolerance during a 3-year follow-up of a community-based cohort in Cape Town, South Africa., Methods: A total of 198 eligible subjects (72.3% women) aged 55.2 years, from the Bellville-South community were followed-up between 2008 and 2011. Baseline and follow-up data collections included glucose tolerance status, anthropometric, blood pressure, lipids, insulin, γ-glutamyltransferase, cotinine, creatinine and HbA1c. Progression in glucose tolerance status at 3-year was the composite of new-onset diabetes and any worsening in glucose tolerance status., Results: The cumulative incidence of progression in glucose tolerance status was: 16.2% (32 participants including 11 with new-onset diabetes), and increased in a stepwise fashion with the number of components of metabolic syndrome (MetS). In age and sex-adjusted logistic regression analyses, MetS [odd ratio: 3.08 (95% CI: 1.34-7.10)], HbA1c [5.26 (1.94-14.24)], HDL-cholesterol [0.05 (0.01-0.33)], γ-glutamyltransferase [1.99 (1.07-3.67)], triglycerides [1.71 (1.13-2.58)] and total/HDL-cholesterol [1.45 (1.08-1.93)] were significant predictors of progression, while borderline effects were observed for baseline glucose and diastolic blood pressure. Markers of adiposity were mostly stable or improved among non-progressors during follow-up, but deteriorated significantly among progressors, resulting in significant statistical interactions., Conclusions: High rates of deterioration of glucose status over time were found in our population, with nearly one-fifth of them acquiring a glucose tolerance worse status within a very short follow-up. Our study extends to this setting the well-known utility of phenotypes of MetS single or in combination, in predicting worsening in glucose tolerance status., (Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.)
- Published
- 2013
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29. Association of cocaine- and amphetamine-related transcript, leptin and leptin receptor gene polymorphisms with anthropometric obesity phenotype indicators in South African learners.
- Author
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Yako YY, Fanampe BL, Hassan MS, Erasmus RT, van der Merwe L, van Rensburg SJ, and Matsha TE
- Subjects
- Adolescent, Anthropometry, Body Weights and Measures, Child, Female, Genetic Predisposition to Disease, Humans, Learning, Male, Obesity diagnosis, Obesity epidemiology, Obesity ethnology, Phenotype, Polymorphism, Genetic physiology, Population genetics, Schools, South Africa epidemiology, Cocaine- and Amphetamine-Regulated Transcript Protein, Leptin genetics, Nerve Tissue Proteins genetics, Obesity genetics, Receptors, Leptin genetics
- Abstract
Background/aims: Obesity has increased rapidly in South African children and adolescents. Genes involved in appetite regulation have been extensively studied worldwide, but their role in the obesity phenotype in South African Black and mixed-ancestry school adolescents is unknown., Methods: Seven common polymorphisms in LEP, GHRL, CART and LEPR were analysed for genotype and haplotype association with anthropometric obesity phenotype indicators in South African Black and mixed-ancestry adolescent school learners., Results: The CART c.517A→G polymorphism was significantly associated with obesity susceptibility. The LEPR Lys(109)Arg G allele was associated with an average reduction of 2.36 kg/m(2) in body mass index (BMI), 5.66 cm in waist circumference (WC) and 1.61 cm in mid-upper-arm circumference (MUAC). This was confirmed by haplotype analysis. Additionally, a haplotype of the LEP polymorphisms significantly increased BMI, MUAC and hip circumference, while LEPR haplotypes were associated with differences in MUAC., Conclusion: Our findings suggest that c.517A→G and Lys(109)Arg contribute to the variation in anthropometric obesity phenotype indicators observed among Black African and mixed-ancestry South African learners. Furthermore, haplotypes of LEP, LEPR and GHRL polymorphisms were associated with varying measurements of weight, BMI and WC. Further studies are required to confirm our results in a larger and homogeneous study population group., (Copyright © 2011 S. Karger AG, Basel.)
- Published
- 2011
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30. Association of the ENPP1 rs997509 polymorphism with obesity in South African mixed ancestry learners.
- Author
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Matsha T, Fanampe, Yako Y, Hassan S, Hoffmann M, Van Der Merwe L, and Erasmus RT
- Subjects
- Adolescent, Case-Control Studies, Child, Female, Humans, Male, South Africa, Obesity genetics, Phosphoric Diester Hydrolases genetics, Polymorphism, Single Nucleotide, Pyrophosphatases genetics
- Abstract
Background: The Ectonucleotide Pyrophosphatase Phosphodiesterasel (ENPP1) polymorphisms have been associated with metabolic traits. There is no data on the effect of ENPP1 in South African children or adults., Objective: To investigate the role of K121Q (rs1044498), rs997509 and rs9402349 in obesity and other components of the metabolic syndrome., Design: A case-control study., Subjects: Sixty four obese and 64 lean mixed ancestry learners., Setting: Western Cape, South Africa., Main Outcome Measure: The ENPP1 rs997509T allele is independently associated with obesity in children of mixed ancestry from South Africa., Results: The T allele frequency of the rs997509 differed significantly between obese and controls, p=0.0100 and increased the risk of being obese, p = 0.0238. Furthermore, the estimated effect of the T allele was an increase of 8.6 cm in waist circumference, 10.2 kg in weight and a corresponding 4.9 kg/m2 in BMI. Individuals carrying both the 121Q and the T allele of rs997509 were more associated with obesity (odds ratio = 3.85, 95% CI: 1.13 to 13.09) whilst those carrying the C allele of rs997509 in the presence of 121Q were likely to be lean with odds ratio of obesity 0.41 (95% CI: 0.19 to 0.87)., Conclusion: Our findings suggest that ENPP1 polymorphisms may contribute to different metabolic characteristics, all of which are associated with insulin resistance in mixed ancestry children of South Africa. However, a larger study is required to confirm findings of this study.
- Published
- 2010
31. Molecular analysis of the parkin gene in South African patients diagnosed with Parkinson's disease.
- Author
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Bardien S, Keyser R, Yako Y, Lombard D, and Carr J
- Subjects
- Adolescent, Adult, Aged, Arginine genetics, Asparagine genetics, Aspartic Acid genetics, Cysteine genetics, DNA Mutational Analysis methods, Exons genetics, Female, Gene Frequency, Heterozygote, Humans, Male, Middle Aged, South Africa ethnology, Young Adult, Parkinson Disease genetics, Point Mutation genetics, Sequence Deletion genetics, Ubiquitin-Protein Ligases genetics
- Abstract
Parkinson's disease (PD) is a common movement disorder which may arise from mutations in the parkin gene. To date, more than 100 different parkin mutations have been reported. The aim of the present study was to determine the frequency of point mutations and homozygous exon deletions in the parkin gene in a group of 91 South African patients diagnosed with PD. Mutation screening of the 12 exons of parkin was performed using single strand conformation polymorphism analysis and the high-resolution melt technique. Six different mutations were identified: four putative disease-causing missense heterozygous changes (H200Q, D280N, E310D and R402C) and two homozygous exon deletions (exons 3 and 4, and exon 4). The D280N and R402C variants have both previously been described but their pathogenic status has been equivocal. In the present study, the D280N variant was observed in three early onset PD-affected siblings and was not present in a 63-year-old unaffected sibling. This data provide further support for the pathogenicity of this variant which is situated within the first RING finger of the RING-box. None of the four missense variants were detected in over 100 ethnic-matched control chromosomes. We conclude that point mutations and homozygous exon deletions in the parkin gene are not a major cause of PD in the South African population. Further studies on this group of patients are needed to determine the contribution of heterozygous exon deletions and insertions in parkin. The present study is the first report on the molecular etiology of PD in South African patients.
- Published
- 2009
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32. Determination of manganese in herbal medicine samples by slurry-sampling electrothermal atomic absorption spectrometry with a metal tube atomizer.
- Author
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Amin MN, Kaneco S, Suzuki T, Taniguchi Y, and Ohta K
- Subjects
- Hot Temperature, Reproducibility of Results, Sensitivity and Specificity, Herbal Medicine, Manganese analysis, Pharmaceutical Preparations chemistry, Spectrophotometry, Atomic methods
- Abstract
An ultrasonic slurry-sampling electrothermal atomic absorption spectrometry with a molybdenum tube atomizer has been developed for the determination of manganese in herbal medicine samples. Ten percent glycerol solution was used as the slurry medium. The optimum pyrolysis temperature was 400 degrees C. The detection limit was 69 fg (3xS/N). Matrix element interference was checked and it was found that glycerol as a chemical modifier eliminated the interference. The amounts of manganese in herbal medicines determined by the proposed method are in good accordance with those measured in dissolved acid-digested samples. The method enables rapid calibration, and simple and rapid analysis of manganese in herbal medicine samples at low cost.
- Published
- 2002
- Full Text
- View/download PDF
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