Search Results Heading

MBRLSearchResults

mbrl.module.common.modules.added.book.to.shelf
Title added to your shelf!
View what I already have on My Shelf.
Oops! Something went wrong.
Oops! Something went wrong.
While trying to add the title to your shelf something went wrong :( Kindly try again later!
Are you sure you want to remove the book from the shelf?
Oops! Something went wrong.
Oops! Something went wrong.
While trying to remove the title from your shelf something went wrong :( Kindly try again later!
    Done
    Filters
    Reset
  • Discipline
      Discipline
      Clear All
      Discipline
  • Is Peer Reviewed
      Is Peer Reviewed
      Clear All
      Is Peer Reviewed
  • Item Type
      Item Type
      Clear All
      Item Type
  • Subject
      Subject
      Clear All
      Subject
  • Year
      Year
      Clear All
      From:
      -
      To:
  • More Filters
75 result(s) for "Subramanian, Venkataraman"
Sort by:
Inflammatory Bowel Disease-Associated Colorectal Cancer Epidemiology and Outcomes: An English Population-Based Study
Patients with inflammatory bowel diseases (IBDs) of the colon are at an increased risk of colorectal cancer (CRC). This study investigates the epidemiology of IBD-CRC and its outcomes. Using population data from the English National Health Service held in the CRC data repository, all CRCs with and without prior diagnosis of IBD (Crohn's, ulcerative colitis, IBD unclassified, and IBD with cholangitis) between 2005 and 2018 were identified. Descriptive analyses and logistic regression models were used to compare the characteristics of the 2 groups and their outcomes up to 2 years. Three hundred ninety thousand six hundred fourteen patients diagnosed with CRC were included, of whom 5,141 (1.3%) also had a previous diagnosis of IBD. IBD-CRC cases were younger (median age at CRC diagnosis [interquartile range] 66 [54-76] vs 72 [63-79] years [ P < 0.01]), more likely to be diagnosed with CRC as an emergency (25.1% vs 16.7% [ P < 0.01]), and more likely to have a right-sided colonic tumor (37.4% vs 31.5% [ P < 0.01]). Total colectomy was performed in 36.3% of those with IBD (15.4% of Crohn's, 44.1% of ulcerative colitis, 44.5% of IBD unclassified, and 67.7% of IBD with cholangitis). Synchronous (3.2% vs 1.6% P < 0.01) and metachronous tumors (1.7% vs 0.9% P < 0.01) occurred twice as frequently in patients with IBD compared with those without IBD. Stage-specific survival up to 2 years was worse for IBD-associated cancers. IBD-associated CRCs occur in younger patients and have worse outcomes than sporadic CRCs. There is an urgent need to find reasons for these differences to inform screening, surveillance, and treatment strategies for CRC and its precursors in this high-risk group.
1883 A Surprising Biopsy Result: Primary GI Amyloidosis
INTRODUCTION:Amyloidosis is the deposition of insoluble extracellular protein fragments. Gastrointestinal (GI) amyloidosis often presents with abdominal pain, weight loss, diarrhea and GI tract bleeding. Diagnosis is confirmed with congo red stain showing green birefringence under polarized light. Treatment differs for each type of amyloidosis; thus, accurate diagnosis is crucial for successful treatment. We present a case of primary GI amyloidosis presenting with new onset microcytic anemia.CASE DESCRIPTION/METHODS:A 73-year-old African American male with past medical history of hypertension, hyperlipidemia and erythrocytosis secondary to obstructive sleep apnea was being seen for a routine follow up by his hematologist. The erythrocytosis was previously evaluated with JAK2 and EPO testing; both negative. He was being treated with periodic phlebotomies, remaining asymptomatic. However, on this particular office visit he was found to have a new microcytic anemia, for which gastrointestinal workup was recommended. Upon evaluation by the gastroenterologist, esophagogastroduodenoscopy (EGD) and colonoscopy were performed. The EGD showed a non-obstructing Schatzki ring, erosive gastritis, a gastric ulcer at the pre-pyloric region, duodenitis and multiple superficial duodenal erosions. The colonoscopy showed a polyp in the cecum and descending colon and diverticulosis. Biopsies were taken during the procedures and returned with amyloid depositions, consistent with GI amyloidosis in the duodenum, stomach and descending colon. A few weeks later, the patient developed rectal bleeding and passage of clots. Repeat colonoscopy was done which showed diffuse large ulcerations in the sigmoid and descending colon. Again, pathology confirmed amyloid depositions in the GI mucosa. Given these surprising findings, his hematologist performed a bone marrow biopsy which showed normocellular marrow with trilineage hematopoiesis, negative for malignancy. Myeloma FISH panel was positive for 11.14 translocation. The patient was diagnosed with light chain myeloma with amyloidosis (AL subtype) involving the GI tract for which steroids and chemotherapy were initiated.DISCUSSION:Our case discusses a rare diagnosis of primary GI amyloidosis. This patient is unique because GI amyloidosis was his primary presentation without any cardiovascular or renal manifestation. Although amyloidosis is rare, it is important to have a high index of suspicion when evaluating new onset anemia of unknown origin.
Peptidylarginine deiminase inhibition is immunomodulatory and vasculoprotective in murine lupus
Recent evidence suggests that enhanced neutrophil extracellular trap (NET) formation activates plasmacytoid dendritic cells and serves as a source of autoantigens in SLE. We propose that aberrant NET formation is also linked to organ damage and to the premature vascular disease characteristic of human SLE. Here, we demonstrate enhanced NET formation in the New Zealand mixed 2328 (NZM) model of murine lupus. NZM mice also developed autoantibodies to NETs as well as the ortholog of human cathelicidin/LL37 (CRAMP), a molecule externalized in the NETs. NZM mice were treated with Cl-amidine, an inhibitor of peptidylarginine deiminases (PAD), to block NET formation and were evaluated for lupus-like disease activity, endothelial function, and prothrombotic phenotype. Cl-amidine treatment inhibited NZM NET formation in vivo and significantly altered circulating autoantibody profiles and complement levels while reducing glomerular IgG deposition. Further, Cl-amidine increased the differentiation capacity of bone marrow endothelial progenitor cells, improved endothelium-dependent vasorelaxation, and markedly delayed time to arterial thrombosis induced by photochemical injury. Overall, these findings suggest that PAD inhibition can modulate phenotypes crucial for lupus pathogenesis and disease activity and may represent an important strategy for mitigating cardiovascular risk in lupus patients.
The Role of Thiopurines in Reducing the Need for Surgical Resection in Crohn's Disease: A Systematic Review and Meta-Analysis
The thiopurine (TP) analogs azathioprine and mercaptopurine have proven efficacy in inducing and maintaining clinical remission in Crohn's disease (CD). Their impact on the long-term need for surgery is uncertain since studies have reported conflicting results. The aim of this systematic review was to summarize and evaluate evidence of the published literature regarding those studies assessing the impact of TPs on the risk of first surgical resection in CD. We searched Medline, EMBASE, CINAHL, and hand searched reference lists of identified articles, without language restrictions in August 2013. Seventeen retrospective observational studies (eight population based, three multicenter, and six referral center) representing 21,632 participants met our inclusion criteria. Of these 10 studies involving 12,586 participants provided data on the hazard ratio (HR) and 95% confidence intervals (CIs) evaluating use of TPs and surgical risk. The combined pooled HR of first intestinal resection with TP use was 0.59 (95% CI 0.48-0.73). TP use is associated with a 40% lowered risk of surgical resection in patients with CD. Despite significant reductions in rates of surgical resection in patients with CD over the last 5 decades and increasing use of TPs, a large proportion of patients with CD still require resectional surgery.
Peptidylarginine deiminase 2-catalyzed histone H3 arginine 26 citrullination facilitates estrogen receptor α target gene activation
Cofactors for estrogen receptor α (ERα) can modulate gene activity by posttranslationally modifying histone tails at target promoters. Here, we found that stimulation of ERα-positive cells with 17β-estradiol (E2) promotes global citrullination of histone H3 arginine 26 (H3R26) on chromatin. Additionally, we found that the H3 citrulline 26 (H3Cit26) modification colocalizes with ERα at decondensed chromatin loci surrounding the estrogen-response elements of target promoters. Surprisingly, we also found that citrullination of H3R26 is catalyzed by peptidylarginine deiminase (PAD) 2 and not by PAD4 (which citrullinates H4R3). Further, we showed that PAD2 interacts with ERα after E2 stimulation and that inhibition of either PAD2 or ERα strongly suppresses E2-induced H3R26 citrullination and ERα recruitment at target gene promoters. Collectively, our data suggest that E2 stimulation induces the recruitment of PAD2 to target promoters by ERα, whereby PAD2 then citrullinates H3R26, which leads to local chromatin decondensation and transcriptional activation.
Identification of PADI2 as a potential breast cancer biomarker and therapeutic target
Background We have recently reported that the expression of peptidylarginine deiminase 2 (PADI2) is regulated by EGF in mammary cancer cells and appears to play a role in the proliferation of normal mammary epithelium; however, the role of PADI2 in the pathogenesis of human breast cancer has yet to be investigated. Thus, the goals of this study were to examine whether PADI2 plays a role in mammary tumor progression, and whether the inhibition of PADI activity has anti-tumor effects. Methods RNA-seq data from a collection of 57 breast cancer cell lines was queried for PADI2 levels, and correlations with known subtype and HER2/ERBB2 status were evaluated. To examine PADI2 expression levels during breast cancer progression, the cell lines from the MCF10AT model were used. The efficacy of the PADI inhibitor, Cl-amidine, was tested in vitro using MCF10DCIS cells grown in 2D-monolayers and 3D-spheroids, and in vivo using MCF10DCIS tumor xenografts. Treated MCF10DCIS cells were examined by flow-cytometry to determine the extent of apoptosis and by RT 2 Profiler PCR Cell Cycle Array to detect alterations in cell cycle associated genes. Results We show by RNA-seq that PADI2 mRNA expression is highly correlated with HER2/ERBB2 (p = 2.2 × 10 6 ) in luminal breast cancer cell lines. Using the MCF10AT model of breast cancer progression, we then demonstrate that PADI2 expression increases during the transition of normal mammary epithelium to fully malignant breast carcinomas, with a strong peak of PADI2 expression and activity being observed in the MCF10DCIS cell line, which models human comedo-DCIS lesions. Next, we show that a PADI inhibitor, Cl-amidine, strongly suppresses the growth of MCF10DCIS monolayers and tumor spheroids in culture. We then carried out preclinical studies in nude (nu/nu) mice and found that Cl-amidine also suppressed the growth of xenografted MCF10DCIS tumors by more than 3-fold. Lastly, we performed cell cycle array analysis of Cl-amidine treated and control MCF10DCIS cells, and found that the PADI inhibitor strongly affects the expression of several cell cycle genes implicated in tumor progression, including p21 , GADD45α , and Ki67 . Conclusion Together, these results suggest that PADI2 may function as an important new biomarker for HER2/ERBB2+ tumors and that Cl-amidine represents a new candidate for breast cancer therapy.
Association Between Thiopurine Use and Nonmelanoma Skin Cancers in Patients With Inflammatory Bowel Disease: A Meta-Analysis
Thiopurines are the mainstay of treatment for patients with inflammatory bowel disease (IBD). Thiopurine therapy increases the risk of nonmelanoma skin cancers (NMSCs) in organ transplant patients. The data on NMSC in patients with IBD on thiopurines is conflicting. We searched electronic databases for full journal articles reporting on the risk of developing NMSC in patients with IBD on thiopurine and hand searched the reference lists of all retrieved articles. Pooled adjusted hazard ratios and 95% confidence intervals (CIs) were determined using a random-effects model. Publication bias was assessed using Funnel plots and Egger's test. Heterogeneity was assessed using Cochran's Q and the I(2) statistic. Eight studies involving 60,351 patients provided data on the risk of developing NMSC in patients with IBD on thiopurines. The pooled adjusted hazards ratio of developing NMSC after exposure to thiopurines in patients with IBD was 2.28 (95% CI: 1.50 to 3.45). There was significant heterogeneity (I(2)=76%) between the studies but no evidence of publication bias. Meta regression analysis suggested that the population studied (hospital-based vs. population-based) and duration of follow-up contributed significantly to heterogeneity. Grouping studies based on population studied and duration showed higher hazard rations in hospital-based and shorter duration studies. The risk of developing NMSC in patients with IBD on thiopurines is only modestly elevated. The difference in pooled risk between population-based and hospital-based studies suggests the possibility that ascertainment bias could have contributed to this increased risk.
Transparency ethics in practice: Revisiting financial conflicts of interest disclosure forms in clinical practice guidelines
Authors of clinical practice guidelines (CPGs) disclose financial conflicts of interest (FCOIs) to promote transparency ethics. Typically, they do so on standard declaration forms containing generic open-ended questions on FCOIs. Yet, the literature is scant on the format and effect of alternative disclosure forms. Does supplementing a standard form with subsequent detailed disclosure forms tailored to the context of the CPG improve the yield or accuracy of FCOIs declarations? For an international CPG in gastroenterology on the endoscopic surveillance for colorectal neoplasia in inflammatory bowel disease, we compared the use of a standard FCOIs disclosure form with a contextual FCOIs disclosure form that detailed commercial relations related to the CPG topic. This included manufacturers of endoscopes, endoscopy equipment and accessories. Participants completed the generic form early, and the supplementary contextual form six months later. We then compared the FCOI disclosures obtained. 26 participants provided FCOIs disclosures using both disclosure forms. We found discrepancies regarding (1) the disclosure of FCOIs (presence/absence), and (2) the listing of financial entities. While the number of participants who disclosed a FCOI remained the same (30.8%) using the two forms, disclosures were not from the same individuals: two additional participants disclosed a FCOI, whereas two participants withdrew previous disclosures. Among those who reported a FCOI in either form, we noted inconsistencies in disclosures for 70% of the participants. This included changes in FCOIs disclosure status or modifications of \"their commercial relations\". Accurate reporting of FCOIs advances the transparency and ethical integrity of CPGs. Our experience suggests that a contextual FCOIs disclosure form tailored to content of the CPG with narrow, detailed questions provides supplementary, more complete FCOIs declarations than generic forms alone. The finding raises challenges on how forms are best written and formatted, optimally timed, and more effectively processed with sensitivity to professional behaviour, so as to heighten transparency.
Update from 2010 (standard operating procedure): protocol for the 2024 British Society of Gastroenterology Guidelines on colorectal surveillance in inflammatory bowel disease
IntroductionThe evolving landscape of inflammatory bowel disease (IBD) necessitates refining colonoscopic surveillance guidelines. This study outlines methodology adopted by the British Society of Gastroenterology (BSG) Guideline Development Group (GDG) for updating IBD colorectal surveillance guidelines.Methods and analysisThe ‘Grading of Recommendations, Assessment, Development and Evaluation’ (GRADE) approach, as outlined in the GRADE handbook, was employed. Thematic questions were formulated using either the ‘patient, intervention, comparison and outcome’ format or the ‘current state of knowledge, area of interest, potential impact and suggestions from experts in the field’ format. The evidence review process included systematic reviews assessed using appropriate appraisal tools. An extensive list of potential outcomes was compiled from literature and expert consultations and then ranked by GDG members. The top outcomes were identified for evidence synthesis in three key areas: utility of surveillance in IBD, quality of bowel preparation and use of advanced imaging techniques in colonoscopy for IBD. Risk thresholding exercises determined specific risk levels for different surveillance strategies and intervals. This approach enabled the GDG to establish precise thresholds for interventions based on relative and absolute risk assessments, directly informing the stratification of surveillance recommendations. Significance of effect sizes (small, moderate, large) will guide the final GRADE assessment of the evidence.Ethics and disseminationEthics approval is not applicable. By integrating clinical expertise, patient experiences and innovative methodologies like risk thresholding, we aim to deliver actionable recommendations for IBD colorectal surveillance. This protocol, complementing the main guidelines, offers GDGs, clinical trialists and practitioners a framework to inform future research and enhance patient care and outcomes.
Potential role for PADI-mediated histone citrullination in preimplantation development
Background The peptidylarginine deiminases (PADIs) convert positively charged arginine residues to neutrally charged citrulline on protein substrates in a process that is known as citrullination or deimination. Previous reports have documented roles for histone citrullination in chromatin remodeling and gene regulation in several tissue types, however, a potential role for histone citrullination in chromatin-based activities during early embryogenesis has not been investigated. Results In the present study, we tested by laser scanning confocal indirect immunofluorescence microscopy whether specific arginine residues on the histone H3 and H4 N-terminal tails (H4R3, H3R2 + 8 + 17, and H3R26) were citrullinated in mouse oocytes and preimplantation embryos. Results showed that all of the tested residues were deiminated with each site showing a unique localization pattern during early development. Given these findings, we next tested whether inhibition of PADI activity using the PADI-specific inhibitor, Cl-amidine, may affect embryonic development. We found that treatment of pronuclear stage zygotes with Cl-amidine reduces both histone H3 and H4 tail citrullination and also potently blocks early cleavage divisions in vitro . Additionally, we found that the Cl-amidine treatment reduces acetylation at histone H3K9, H3K18, and H4K5 while having no apparent effect on the repressive histone H3K9 dimethylation modification. Lastly, we found that treatment of zygotes with trichostatin A (TSA) to induce hyperacetylation also resulted in an increase in histone citrullination at H3R2 + 8 + 17. Conclusions Given the observed effects of Cl-amidine on embryonic development and the well documented correlation between histone acetylation and transcriptional activation, our findings suggest that histone citrullination may play an important role in facilitating gene expression in early embryos by creating a chromatin environment that is permissive for histone acetylation.