Publications by authors named "Shaheena Bashir"

16 Publications

  • Page 1 of 1

A noninvasive urine-based methylation biomarker panel to detect bladder cancer and discriminate cancer grade.

Urol Oncol 2020 06 18;38(6):603.e1-603.e7. Epub 2020 Feb 18.

Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Canada; Department of Surgical Oncology, Division of Urology, Princess Margaret Cancer Centre, University Health Network, Toronto, Canada; Department of Surgery, Division of Urology, Mount Sinai Hospital, Toronto, Canada. Electronic address:

Background: Highly sensitive and specific urinary biomarkers for the early detection of bladder cancer (BC) to improve the performance of urinary cytology are needed.

Objective: To investigate the usefulness of methylation markers in voided urine to identify BC presence and grade.

Design, Settings, And Participants: Using genome-wide methylation strategies in Toronto, Canada and Liège, Belgium, we have identified differentially methylated genes (TWIST1, RUNX3, GATA4, NID2, and FOXE1) in low-grade vs. high-grade BC tissue and urine. We accrued urine samples from 313 patients using a 2:1 ratio in a case-control setting from Toronto, Canada, Halifax, Canada, and Zurich, Switzerland. We studied the usefulness of these 5 methylated genes to identify BC and discriminate cancer grade in voided urine specimens. Urinary cell sediment DNA was evaluated using qPCR-based MethyLight assay. Multivariable logistic regression prediction models were created.

Results And Limitations: We included 211 BC patients (180 nonmuscle invasive) and 102 controls. In univariate analyses, all methylated genes significantly predicted BC vs. no BC, and high grade vs. low grade (all P < 0.05). In multivariable analysis, NID2, TWIST1, and age were independent predictors of BC (all P < 0.05). Sensitivity of NID2 and TWIST1 to predict BC and BC grade was 76.2% and 77.6%, respectively, whereas specificity was 83.3% and 61.1%, respectively. Multivariable models predicting BC overall and discriminating between high-grade and low-grade BC reached area under the receiver operating characteristics curves of 0.89 and 0.78, respectively.

Conclusions: This multi-centric study in a real life scenario (different countries, techniques, and pathologists) supports the promise of epigenetic urinary markers in noninvasively detecting BC. With sensitivities and specificities in the range of 80%, the overall performance characteristics of this panel of methylated genes probably does not allow such signature to significantly alter clinical care at this stage but is worth further studying for instance in BC surveillance or screening in high-risk populations.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.urolonc.2020.01.007DOI Listing
June 2020

Reply by Authors.

J Urol 2019 08 8;202(2):325. Epub 2019 Jul 8.

Division of Urology, Departments of Surgery and Surgical Oncology, Princess Margaret Cancer Centre, University Health Network and University of Toronto , Toronto , Ontario , Canada.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1097/01.JU.0000558494.56102.dbDOI Listing
August 2019

Decreasing Postoperative Blood Loss by Topical vs. Intravenous Tranexamic Acid in Open Cardiac Surgery (DEPOSITION) study: Results of a pilot study.

J Card Surg 2019 May 25;34(5):305-311. Epub 2019 Mar 25.

Division of Cardiac Surgery, David Braley Cardiac, Vascular and Stroke Research Institute, Hamilton General Hospital, McMaster University, Hamilton, Ontario, Canada.

Background: Cardiac surgery patients are at high risk for postoperative bleeding. Intravenous (IV) tranexamic acid (TxA) is a commonly used antifibrinolytic drug, but is associated with postoperative seizures. We conducted this pilot randomized controlled trial (RCT) to determine the feasibility of a larger trial that will be designed to investigate the impact of TxA administration route, intrapericardial (IP) vs IV, on postoperative bleeding and seizures.

Methods: In this single-center, double-blinded, pilot RCT we enrolled adult patients undergoing nonemergent on-pump cardiac operations through a median sternotomy. Participants were randomized to IP or IV TxA groups. The primary outcomes were cumulative chest tube drainage, transfusion requirements, and incidence of postoperative seizures.

Results: A total of 97 participants were randomized to the intervention and control groups. Baseline characteristics were similar in both groups. Most participants underwent a CABG and/or aortic valve replacement. There was no statistical difference. The IP TxA group was found to have a tendency for less chest tube drainage in comparison to the IV TxA group, 500.5 (370.0-700.0) and 540.0 (420.0-700.0) mL, respectively, which was not statistically significant (P = 0.2854). Fewer participants in the IP TxA group with cardiac tamponade and/or required a reoperation for bleeding and fewer packed red blood cell transfusions. None of the IP TxA group developed seizure vs one from the IV TxA group.

Conclusion: This is the first known pilot RCT to investigate the role of TxA route of administration in open cardiac surgery. Intrapericardial TxA shows promising results with decreased bleeding, transfusion requirements, reoperations, and postoperative seizures. A larger RCT is needed to confirm these results and lead to a change in practice.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/jocs.14027DOI Listing
May 2019

Association of rs10490924 in ARMS2/HTRA1 with age-related macular degeneration in the Pakistani population.

Ann Hum Genet 2019 07 20;83(4):285-290. Epub 2019 Mar 20.

Transalational Genomics Laboratory, Department of Biosciences, COMSATS University Islamabad, Pakistan.

Age-related macular degeneration (AMD) is a disease of the elderly in which central vision is lost because of degenerative changes of the macula. The current study investigated the association of single-nucleotide polymorphisms (SNPs) with AMD in the Pakistani population. Four SNPs were analyzed in this study: rs1061170 in the CFH, rs429608 near CFB, rs2230199 in the C3, and rs10490924 in ARMS2/HTRA1. This case-control association study was conducted on 300 AMD patients (125 wet AMD and 175 dry AMD) and 200 unaffected age- and gender-matched control individuals. The association of the SNP genotypes and allele frequency distributions were compared between patients and healthy controls, keeping age, gender, and smoking status as covariates. A significant genotype and variant allele association was found of rs10490924 in ARMS2/HTRA1 with wet AMD, while the SNPs in CFH, CFB, and C3 were not associated with AMD in the current Pakistani cohort. The lack of association of CFH, CFB, and C3 may be attributed to limited sample size. This study demonstrates that genetic causative factors of AMD differ among populations and supports the need for genetic association studies among cohorts from various populations to increase our global understanding of the disease pathogenesis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/ahg.12311DOI Listing
July 2019

Risk of Bone Fractures Following Urinary Intestinal Diversion: A Population Based Study.

J Urol 2019 08 8;202(2):319-325. Epub 2019 Jul 8.

Division of Urology, Departments of Surgery and Surgical Oncology, Princess Margaret Cancer Centre, University Health Network and University of Toronto , Toronto , Ontario , Canada.

Purpose: Patients with bladder cancer who undergo intestinal urinary diversion may be at increased risk for bone fractures thought to be secondary to chronic metabolic acidosis and ensuing bone loss. Our main objective was to assess whether patients who undergo intestinal urinary diversion are at increased risk for fracture.

Materials And Methods: Patients who underwent intestinal urinary diversion between 1994 and 2014 in Ontario, Canada were identified using linked administrative databases. Patients were categorized as undergoing diversion for bladder cancer or nonbladder cancer causes and matched 4:1 to a healthy cohort. We determined incidence rates of the incidence of fractures per 100 person-years. Multivariable Cox proportional hazards models were used to evaluate the impact of intestinal urinary diversion on the risk of fracture.

Results: Overall 4,301 patients with and 907 without bladder cancer underwent intestinal urinary diversion. The fracture incidence rate was significantly greater in the bladder cancer and nonbladder cancer cohorts compared to respective matched controls. In the bladder cancer cohort vs matched controls there were 4.41 vs 2.63 fractures per 100 person-years and in the nonbladder cancer cohort vs matched controls there were 5.67 vs 3.51 fractures per 100 person-years (each p <0.001). On multivariable analysis patients who underwent intestinal urinary diversion for bladder cancer or nonbladder cancer reasons had significantly shorter fracture-free survival compared to the respective matched cohorts (HR 1.48, IQR 1.35-1.63, and HR 1.48, IQR 1.31-1.69, respectively).

Conclusions: Our results demonstrated that regardless of age patients with intestinal urinary diversion are at increased risk for bone fractures compared to the general population. Our findings are in line with previous reports and support the need for bone health monitoring.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1097/JU.0000000000000213DOI Listing
August 2019

Impact of oral hypoglycemic agents on mortality among diabetic patients with non-muscle-invasive bladder cancer: A populationbased analysis.

Can Urol Assoc J 2018 Jun 23;12(6):203-210. Epub 2018 Feb 23.

Division of Urology, Departments of Surgery and Surgical Oncology, Princess Margaret Cancer Centre, University Health Network and the University of Toronto, Toronto, ON; Canada.

Introduction: Non-muscle-invasive bladder cancer (NMIBC) accounts for 75-85% of all urothelial bladder cancers (UBC). Many UBC patients are also afflicted by diabetes mellitus (DM). It has been postulated that several oral hypoglycemic agents could impact disease-specific survival (DSS), but the data are sparse among NMIBC patients. Our primary objective was to evaluate the impact of metformin on DSS and overall survival (OS) in NMIBC patients.

Methods: This is a retrospective, population-based study that used linked administrative databases to identify diabetic patients ≥66 years who were subsequently diagnosed with NMIBC in Ontario between 1992 and 2012. Cumulative use of metformin and other hypoglycemic agent were calculated before and after NMIBC diagnosis. DSS and OS were estimated using multivariable competing risk and Cox proportional hazards models, respectively.

Results: A total of 1742 subjects were included in the study. After a median followup of 5.2 years, 1122 (64%) had died, including 247 (15%) deaths as a result of UBC. On multivariable analysis, cumulative duration of metformin use after NMIBC diagnosis did not appear to impact DSS (hazard ratio [HR] 1.1; 95% confidence interval [CI] 0.92-1.2), whereas glyburide use appeared to have a detrimental effect (HR 1.17; 95% CI 1.02-1.3). None of the other hypoglycemic agents had an impact on OS.

Conclusions: In this large, population-based study, we have provided further evidence that metformin use does not significantly impact DSS among diabetic patients diagnosed with NMIBC. However, our findings demonstrate that glyburide use inversely affects DSS. The detrimental effect of glyburide on DSS will require further validation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.5489/cuaj.4870DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5994977PMC
June 2018

Effectiveness and tolerability of first-line autologous stem cell transplant and maintenance rituximab for mantle cell lymphoma.

Bone Marrow Transplant 2018 03 21;53(3):347-351. Epub 2017 Dec 21.

Department of Medical Oncology and Hematology, Princess Margaret Cancer Centre, and Department of Medicine, University of Toronto, Toronto, ON, Canada.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41409-017-0054-8DOI Listing
March 2018

Late Cardiac Toxicity After Mediastinal Radiation Therapy for Hodgkin Lymphoma: Contributions of Coronary Artery and Whole Heart Dose-Volume Variables to Risk Prediction.

Int J Radiat Oncol Biol Phys 2017 08 27;98(5):1116-1123. Epub 2017 Mar 27.

Radiation Medicine Program, Princess Margaret Cancer Centre, University of Toronto, Toronto, Ontario, Canada; Pediatric Oncology Group of Ontario, Toronto, Ontario, Canada. Electronic address:

Purpose: Mediastinal radiation therapy (RT) for Hodgkin lymphoma (HL) is associated with late cardiotoxicity, but there are limited data to indicate which dosimetric parameters are most valuable for predicting this risk. This study investigated which whole heart dosimetric measurements provide the most information regarding late cardiotoxicity, and whether coronary artery dosimetry was more predictive of this outcome than whole heart dosimetry.

Methods And Materials: A random sample of 125 HL patients treated with mediastinal RT was selected, and 3-dimensional cardiac dose-volume data were generated from historical plans using validated methods. Cardiac events were determined by linking patients to population-based datasets of inpatient and same-day hospitalizations and same-day procedures. Variables collected for the whole heart and 3 coronary arteries included the following: Dmean, Dmax, Dmin, dose homogeneity, V5, V10, V20, and V30. Multivariable competing risk regression models were generated for the whole heart and coronary arteries.

Results: There were 44 cardiac events documented, of which 70% were ischemic. The best multivariable model included the following covariates: whole heart Dmean (hazard ratio [HR] 1.09, P=.0083), dose homogeneity (HR 0.94, P=.0034), male sex (HR 2.31, P=.014), and age (HR 1.03, P=.0049). When any adverse cardiac event was the outcome, models using coronary artery variables did not perform better than models using whole heart variables. However, in a subanalysis of ischemic cardiac events only, the model using coronary artery variables was superior to the whole heart model and included the following covariates: age (HR 1.05, P<.001), volume of left anterior descending artery receiving 5 Gy (HR 0.98, P=.003), and volume of left circumflex artery receiving 20 Gy (HR 1.03, P<.001).

Conclusion: In addition to higher mean heart dose, increasing inhomogeneity in cardiac dose was associated with a greater risk of late cardiac effects. When all types of cardiotoxicity were evaluated, the whole heart variable model outperformed the coronary artery models. However, when events were limited to ischemic cardiotoxicity, the coronary artery-based model was superior.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ijrobp.2017.03.026DOI Listing
August 2017

Propensity Score Analysis of Radical Cystectomy Versus Bladder-Sparing Trimodal Therapy in the Setting of a Multidisciplinary Bladder Cancer Clinic.

J Clin Oncol 2017 Jul 14;35(20):2299-2305. Epub 2017 Apr 14.

Girish S. Kulkarni, Thomas Hermanns, Yanliang Wei, Bimal Bhindi, Raj Satkunasivam, Paul Athanasopoulos, Peter J. Bostrom, Kathy Li, Arnoud J. Templeton, Srikala S. Sridhar, Peter Chung, Robert G. Bristow, Michael Milosevic, Padraig Warde, Neil E. Fleshner, Michael A.S. Jewett, Shaheena Bashir, and Alexandre R. Zlotta, Princess Margaret Cancer Center, University Health Network, University of Toronto; Cynthia Kuk and Alexandre R. Zlotta, Mount Sinai Hospital, University of Toronto; Theodorus H. Van Der Kwast, University Health Network, University of Toronto, Toronto, ON, Canada.

Purpose Multidisciplinary management improves complex treatment decision making in cancer care, but its impact for bladder cancer (BC) has not been documented. Although radical cystectomy (RC) currently is viewed as the standard of care for muscle-invasive bladder cancer (MIBC), radiotherapy-based, bladder-sparing trimodal therapy (TMT) that combines transurethral resection of bladder tumor, chemotherapy for radiation sensitization, and external beam radiotherapy has emerged as a valid treatment option. In the absence of randomized studies, this study compared the oncologic outcomes between patients treated with RC or TMT by using a propensity score matched-cohort analysis. Methods Data from patients treated in a multidisciplinary bladder cancer clinic (MDBCC) from 2008 to 2013 were reviewed retrospectively. Those who received TMT for MIBC were identified and matched (for sex, cT and cN stage, Eastern Cooperative Oncology Group status, Charlson comorbidity score, treatment date, age, carcinoma in situ status, and hydronephrosis) with propensity scores to patients who underwent RC. Overall survival and disease-specific survival (DSS) were assessed with Cox proportional hazards modeling and a competing risk analysis, respectively. Results A total of 112 patients with MIBC were included after matching (56 who had been treated with TMT, and 56 who underwent RC). The median age was 68.0 years, and 29.5% had stage cT3/cT4 disease. At a median follow-up of 4.51 years, there were 20 deaths (35.7%) in the RC group (13 as a result of BC) and 22 deaths (39.3%) in the TMT group (13 as a result of BC). The 5-year DSS rate was 73.2% and 76.6% in the RC and TMT groups, respectively ( P = .49). Salvage cystectomy was performed in 6 (10.7%) of 56 patients who received TMT. Conclusion In the setting of a MDBCC, TMT yielded survival outcomes similar to those of matched patients who underwent RC. Appropriately selected patients with MIBC should be offered the opportunity to discuss various treatment options, including organ-sparing TMT.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1200/JCO.2016.69.2327DOI Listing
July 2017

Effect of statins as a secondary chemopreventive agent among individuals with non-muscle-invasive bladder cancer: A population-based analysis.

Urol Oncol 2017 06 9;35(6):342-348. Epub 2017 Feb 9.

Division of Urology, Departments of Surgery and Surgical Oncology, Princess Margaret Cancer Centre, University Health Network, University of Toronto, Toronto, ON, Canada. Electronic address:

Background: Non-muscle-invasive bladder cancer (NMIBC) is especially prevalent among the elderly. Many patients with NMIBC also have significant concomitant comorbidities, including cardiovascular diseases and hypercholesterolemia. Statins are the most commonly used cholesterol-depleting agents, and they may possess anticancer properties. The objective of this population-based study was to evaluate the effect of statins on the survival of individuals diagnosed with NMIBC.

Methods: This is a retrospective population-based cohort study that used administrative databases to identify individuals 66 years of age and older who were diagnosed with NMIBC between 1992 and 2012. Subjects with documented use of statins before they were 66 years of age were excluded from the analysis. Cumulative daily use of statins was calculated before and after the diagnosis of NMIBC. Their effect on cancer-specific survival and overall survival was estimated using a multivariable competing risk and Cox proportional hazards model, respectively.

Results: The final cohort was composed of 13,811 individuals≥66 years diagnosed with NMIBC. Of these, 4,748 individuals (34%) were exposed to statins during follow-up. The median statin exposure after NMIBC diagnosis was 21.4 months (interquartile range: 7.8-45.4). After a median follow-up of 7.1 years (interquartile range: 4.0-11.3) from NMIBC diagnosis, 8,900 (64%) individuals had died. The cumulative use of statins after NMIBC diagnosis did not significantly affect cancer-specific survival (P = 0.10). However, its cumulative use after NMIBC diagnosis was associated with a better overall survival ([0.93; 95% CI: 0.91-0.96], per year of use).

Conclusions: This large population-based study has provided evidence that cumulative statin use was not associated with an improved cancer-specific survival among individuals with NMIBC. However, our findings did demonstrate that statin users had a better overall survival than nonusers.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.urolonc.2016.12.009DOI Listing
June 2017

Comparison of robotic and laparoscopic colorectal resections with respect to 30-day perioperative morbidity.

Can J Surg 2016 Aug;59(4):262-7

From the Department of Surgery, University of Toronto, Toronto, Ont. (Feinberg, Quereshy); the Division of General Surgery, University Health Network, Toronto, Ont. (Elnahas, Cleghorn, Quereshy); the Department of Biostatistics, Princess Margaret Cancer Centre, Toronto, Ont. (Bashir); and the Department of Surgical Oncology, Princess Margaret Cancer Centre, University of Toronto, Toronto, Ont. (Quereshy).

Background: Robotic surgery has emerged as a minimally invasive alternative to traditional laparoscopy. Robotic surgery addresses many of the technical and ergonomic limitations of laparoscopic surgery, but the literature regarding clinical outcomes in colorectal surgery is limited. We sought to compare robotic and laparoscopic colorectal resections with respect to 30-day perioperative outcomes.

Methods: The American College of Surgeons National Surgical Quality Improvement Program database was used to identify all patients who underwent robotic or laparoscopic colorectal surgery in 2013. We performed a logistic regression analysis to compare intraoperative variables and 30-day outcomes.

Results: There were 8392 patients who underwent laparoscopic colorectal surgery and 472 patients who underwent robotic colorectal surgery. The robotic cohort had a lower incidence of unplanned intraoperative conversion (9.5% v. 13.7%, p = 0.008). There were no significant differences between robotic and laparoscopic surgery with respect to other intraoperative and postoperative outcomes, such as operative duration, length of stay, postoperative ileus, anastomotic leak, venous thromboembolism, wound infection, cardiac complications and pulmonary complications. On multivariable analysis, robotic surgery was protective for unplanned conversion, while male sex, malignancy, Crohn disease and diverticular disease were all associated with open conversion.

Conclusion: Robotic colorectal surgery has comparable 30-day perioperative morbidity to laparoscopic surgery and may decrease the rate of intraoperative conversion in select patients.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1503/cjs.016615DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4961489PMC
August 2016

Role of ACE and PAI-1 Polymorphisms in the Development and Progression of Diabetic Retinopathy.

PLoS One 2015 14;10(12):e0144557. Epub 2015 Dec 14.

Department of Biosciences, COMSATS Institute of Information Technology, Islamabad, Pakistan.

In the present study we determined the association of angiotensin converting enzyme (ACE) and plasminogen activator inhibitor-1 (PAI-1) gene polymorphisms with diabetic retinopathy (DR) and its sub-clinical classes in Pakistani type 2 diabetic patients. A total of 353 diabetic subjects including 160 DR and 193 diabetic non retinopathy (DNR) as well as 198 healthy controls were genotyped by allele specific polymerase chain reaction (PCR) for ACE Insertion/Deletion (ID) polymorphism, rs4646994 in intron 16 and PAI-1 4G/5G (deletion/insertion) polymorphism, rs1799768 in promoter region of the gene. To statistically assess the genotype-phenotype association, multivariate logistic regression analysis was applied to the genotype data of DR, DNR and control individuals as well as the subtypes of DR. The ACE genotype ID was found to be significantly associated with DR (p = 0.009, odds ratio (OR) 1.870 [95% confidence interval (CI) = 1.04-3.36]) and its sub-clinical class non-proliferative DR (NPDR) (p = 0.006, OR 2.250 [95% CI = 1.098-4.620]), while PAI polymorphism did not show any association with DR in the current cohort. In conclusion in Pakistani population the ACE ID polymorphism was observed to be significantly associated with DR and NPDR, but not with the severe form of the disease i.e. proliferative DR (PDR).
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0144557PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4679138PMC
June 2016

Inhibition of the Mitochondrial Protease ClpP as a Therapeutic Strategy for Human Acute Myeloid Leukemia.

Cancer Cell 2015 Jun;27(6):864-76

Princess Margaret Cancer Centre, Toronto, ON M5G 2M9, Canada; Department of Medicine, University of Toronto, Toronto, ON M5G 2C4, Canada. Electronic address:

From an shRNA screen, we identified ClpP as a member of the mitochondrial proteome whose knockdown reduced the viability of K562 leukemic cells. Expression of this mitochondrial protease that has structural similarity to the cytoplasmic proteosome is increased in leukemic cells from approximately half of all patients with AML. Genetic or chemical inhibition of ClpP killed cells from both human AML cell lines and primary samples in which the cells showed elevated ClpP expression but did not affect their normal counterparts. Importantly, Clpp knockout mice were viable with normal hematopoiesis. Mechanistically, we found that ClpP interacts with mitochondrial respiratory chain proteins and metabolic enzymes, and knockdown of ClpP in leukemic cells inhibited oxidative phosphorylation and mitochondrial metabolism.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ccell.2015.05.004DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4461837PMC
June 2015

IL-7 coordinates proliferation, differentiation and Tcra recombination during thymocyte β-selection.

Nat Immunol 2015 Apr 2;16(4):397-405. Epub 2015 Mar 2.

1] Program in Developmental and Stem Cell Biology, Hospital for Sick Children Research Institute, Toronto, Canada. [2] Department of Immunology, University of Toronto, Toronto, Canada.

Signaling via the pre-T cell antigen receptor (pre-TCR) and the receptor Notch1 induces transient self-renewal (β-selection) of TCRβ(+) CD4(-)CD8(-) double-negative stage 3 (DN3) and DN4 progenitor cells that differentiate into CD4(+)CD8(+) double-positive (DP) thymocytes, which then rearrange the locus encoding the TCR α-chain (Tcra). Interleukin 7 (IL-7) promotes the survival of TCRβ(-) DN thymocytes by inducing expression of the pro-survival molecule Bcl-2, but the functions of IL-7 during β-selection have remained unclear. Here we found that IL-7 signaled TCRβ(+) DN3 and DN4 thymocytes to upregulate genes encoding molecules involved in cell growth and repressed the gene encoding the transcriptional repressor Bcl-6. Accordingly, IL-7-deficient DN4 cells lacked trophic receptors and did not proliferate but rearranged Tcra prematurely and differentiated rapidly. Deletion of Bcl6 partially restored the self-renewal of DN4 cells in the absence of IL-7, but overexpression of BCL2 did not. Thus, IL-7 critically acts cooperatively with signaling via the pre-TCR and Notch1 to coordinate proliferation, differentiation and Tcra recombination during β-selection.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/ni.3122DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4368453PMC
April 2015

Association of a polymorphism in the BIRC6 gene with pseudoexfoliative glaucoma.

PLoS One 2014 13;9(8):e105023. Epub 2014 Aug 13.

Department of Ophthalmology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands; Department of Human Genetics, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands.

Recently an association was observed between alleles in genes of the unfolded protein response pathway and primary open angle glaucoma (POAG). The goal of the current study is to investigate the role of these two genes, protein disulphide isomerase A member 5 (PDIA5) and baculoviral IAP repeat containing 6 (BIRC6), in different forms of glaucoma. 278 patients with POAG, 132 patients with primary angle closure glaucoma (PACG) and 135 patients with pseudoexfoliative glaucoma (PEXG) were genotyped for single nucleotide polymorphisms (SNPs) rs11720822 in PDIA5 and 471 POAG, 184 PACG and 218 PEXG patients were genotyped for rs2754511 in BIRC6. Genotyping was done by allelic discrimination PCR, and genotype and allele frequencies were calculated. Logistic regression analyses were performed using R software to determine the association of these SNPs with glaucoma. The allele and genotype frequencies of rs11720822 in PDIA5 were not associated with POAG, PACG or PEXG. The TT genotype of rs2754511 in BIRC6 was found to be protective for PEXG (p = 0.05, OR 0.42 [0.22-0.81]) in the Pakistani population, but not for POAG or PACG. This study did not confirm a previously reported association of risk alleles in PDIA5 and BIRC6 with POAG, but did demonstrate a protective role of the T allele of rs2754511 in the BIRC6 gene in PEXG. This supports a role for the unfolded protein response pathway and regulation of apoptotic cell death in the pathogenesis of PEXG.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0105023PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4132048PMC
December 2015

Extent of liver inflammation in predicting response to interferon α & Ribavirin in chronic hepatitis C patients: a cohort study.

BMC Gastroenterol 2012 Jun 14;12:71. Epub 2012 Jun 14.

Department of Community Health Sciences, Aga Khan University, Karachi, Pakistan.

Background: Liver inflammation due to HCV infection leads to fibrosis, which is an independent predictor of treatment response to interferon therapy in Chronic Hepatitis C (CHC) patients. This relationship has not been studied for liver inflammation on pretreatment liver biopsy and End of Treatment Response (ETR). ALT is a less invasive test than liver biopsy for measuring liver inflammation. Aim of this study was to compare ETR to Interferon α (recombinant Interferon) & Ribavirin in CHC patients having higher and lower grades of liver inflammation and to determine the diagnostic accuracy of pretreatment ALT for grades of liver inflammation.

Methods: A retrospective cohort of 876 naïve CHC patients, who completed Interferon α & Ribavirin for 24 weeks, was studied for ETR. Pretreatment grade of inflammation on liver biopsy was taken as the exposure variable. It was classified as high if there was moderate or severe and low if there was minimal or mild. Multivariable logistic regression modeling was performed. Diagnostic accuracy of pretreatment ALT for liver inflammation grades was determined by computing Area Under the Receiver Operator Curve (AUROC).

Results: Of all patients, 672 having diagnostic liver biopsy and ETR available were analyzed. Among them, 103 had high and 569 had low grades of liver inflammation. Mean age was 36.9 (SD 9.1) years, with patients with high grades being older than those with low grades inflammation (p = 0.03). High grades of liver inflammation was associated with ETR (RR 1.17, 95% CI 1.12-1.18) adjusting for age, Total Leukocyte count (TLC) and pretreatment levels of ALT, irrespective of liver fibrosis. This relation remained significant for 'bridging fibrosis and cirrhosis' and not for 'no' or 'portal fibrosis'. AUROC of pretreatment ALT for males and females was moderately accurate for severe inflammation compared to minimal inflammation and less accurate for high grades compared to low grades.

Conclusions: ETR in patients with higher grades of liver inflammation was 17% higher than those with lower grades irrespective of fibrosis and 9% higher for bridging fibrosis and cirrhosis. Pretreatment ALT was moderately accurate for severe inflammation only on liver biopsy in both males and females.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/1471-230X-12-71DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3502580PMC
June 2012