Publications by authors named "Sameena Nawaz"

Inducible pluripotent stem cell-derived human β-like cells (BLCs) hold promise for both therapy and disease modeling, but their generation remains challenging and their functional analyses beyond transcriptomic and morphological assessments remain limited. Here, we validate an approach using multicellular and single-cell electrophysiological tools to evaluate function of BLCs from pioneer protocols that can be easily adapted to more differentiated BLCs. The multi-electrode arrays (MEAs) measuring the extracellular electrical activity revealed that BLCs, like primary β-cells, are electrically coupled and produce slow potential (SP) signals that are closely linked to insulin secretion.

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iPSC-derived human β-like cells (BLC) hold promise for both therapy and disease modelling, but their generation remains challenging and their functional analyses beyond transcriptomic and morphological assessments remain limited. Here, we validate an approach using multicellular and single cell electrophysiological tools to evaluate BLCs functions. The Multi-Electrode Arrays (MEAs) measuring the extracellular electrical activity revealed that BLCs are electrically coupled, produce slow potential (SP) signals like primary β-cells that are closely linked to insulin secretion.

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Hyperreactive platelets are commonly observed in diabetic patients indicating a potential link between glucose homeostasis and platelet reactivity. This raises the possibility that platelets may play a role in the regulation of metabolism. Pancreatic β cells are the central regulators of systemic glucose homeostasis.

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Patients with type 2 diabetes vary in their response to currently available therapeutic agents (including GLP-1 receptor agonists) leading to suboptimal glycemic control and increased risk of complications. We show that human carriers of hypomorphic T2D-risk alleles in the gene encoding peptidyl-glycine alpha-amidating monooxygenase as well as -knockout mice, display increased resistance to GLP-1 . inactivation in mice leads to reduced gastric GLP-1R expression and faster gastric emptying: this persists during GLP-1R agonist treatment and is rescued when GLP-1R activity is antagonized, indicating resistance to GLP-1's gastric slowing properties.

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Identification of the genes and processes mediating genetic association signals for complex diseases represents a major challenge. As many of the genetic signals for type 2 diabetes (T2D) exert their effects through pancreatic islet-cell dysfunction, we performed a genome-wide pooled CRISPR loss-of-function screen in a human pancreatic beta cell line. We assessed the regulation of insulin content as a disease-relevant readout of beta cell function and identified 580 genes influencing this phenotype.

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Background: Tetraspanin-7 (Tspan7) is an islet autoantigen involved in autoimmune type 1 diabetes and known to regulate β-cell L-type Ca channel activity. However, the role of Tspan7 in pancreatic β-cell function is not yet fully understood.

Methods: Histological analyses were conducted using immunostaining.

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Using chromatin conformation capture, we show that an enhancer cluster in the STARD10 type 2 diabetes (T2D) locus forms a defined 3-dimensional (3D) chromatin domain. A 4.1-kb region within this locus, carrying 5 T2D-associated variants, physically interacts with CTCF-binding regions and with an enhancer possessing strong transcriptional activity.

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Exome sequencing in diabetes presents a diagnostic challenge because depending on frequency, functional impact, and genomic and environmental contexts, HNF1A variants can cause maturity-onset diabetes of the young (MODY), increase type 2 diabetes risk, or be benign. A correct diagnosis matters as it informs on treatment, progression, and family risk. We describe a multi-dimensional functional dataset of 73 HNF1A missense variants identified in exomes of 12,940 individuals.

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Objective: To describe infants with acute gastroenteritis symptoms in primary and secondary care who have the Rotarix vaccine-derived G1P[8] rotavirus strain identified in their stools.

Design: This is a prospective national surveillance conducted by Public Health England (PHE). Rotavirus-positive samples from vaccine-eligible children are routinely submitted to PHE for confirmation, and general practitioners are requested to complete a surveillance questionnaire for all cases.

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Healthcare-associated infections represent a major threat to patient, staff and visitor safety. Identification of episodes that are likely to have resulted from nosocomial transmission has important implications for infection control. Routinely collected data on ward admissions and sample dates, combined with pathogen genomic information could provide useful insights.

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IntroductionRotavirus vaccination with the live-attenuated monovalent (a G1P[8] human rotavirus strain) two-dose Rotarix vaccine was introduced in England in July 2013. Since then, there have been significant reductions in rotavirus gastroenteritis incidence.AimWe assessed the vaccine's impact on rotavirus genotype distribution and diversity 3 years post-vaccine introduction.

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Background: The oral infant rotavirus vaccine, Rotarix, was introduced in England and Wales in July 2013. We estimated the impact on laboratory-confirmed rotavirus infections and hospitalizations for all-cause acute gastroenteritis (AGE) during the first year after introduction.

Methods: We extracted data on laboratory-confirmed rotavirus infections (July 2000 through June 2015) and all-cause AGE-associated hospitalizations (July 2007 through June 2014) for all age groups using national databases (LabBase2 and HES).

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Rotavirus severe disease in children is now vaccine-preventable and the roll-out of vaccination programs globally is expected to make a significant impact in the reduction of morbidity and mortality in children <5 years of age. Rotavirus is also a pathogen of other mammals and birds, and its segmented RNA genome can lead to the emergence of new or unusual strains in human population via interspecies transmission and reassortment events. Despite the efficacy and impact of rotavirus vaccine in preventing severe diarrhea, the correlates of protection remain largely unknown.

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Rotavirus is endemic in pig farms where it causes a loss in production. This study is the first to characterise porcine rotavirus circulating in UK pigs. Samples from diarrheic pigs with rotavirus enteritis obtained between 2010 and 2012 were genotyped in order to determine the diversity of group A rotavirus (GARV) in UK pigs.

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Noroviruses are a common cause of gastroenteritis worldwide, but outbreaks appear to be more common in industrialized countries than in developing countries, possibly reflecting differences in exposure and immunity. In this study, age-stratified sera from India and UK populations were analysed for the presence of norovirus-genogroup II specific IgG by a time resolved immunofluorescence assay and relative levels of antibodies in the two populations were compared. Antibody levels were higher among all age groups in India than in UK and increased with age in India, whereas in the UK, levels of antibody decreased in adulthood.

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Background: Rotavirus (RV) vaccines have been available on the private market in Portugal since 2006, with an estimated coverage rising from 16 to 42% between 2007 and 2010.

Objectives: To assess trends, surveillance of children presenting with acute gastroenteritis (AG) to a large paediatric emergency service (ES) in the central region of Portugal was conducted yearly during the winter-spring seasons.

Study Design: Stool samples, collected throughout five epidemic seasons (January-June, 2006 to 2010) from children ≤ 36 months of age attending the ES with AG, were tested for RV by immunochromatographic rapid test and positive samples were genotyped.

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Gastroenteritis is a common illness causing considerable morbidity and mortality worldwide. Despite improvements in detection methods, a significant diagnostic gap still remains. Human bocavirus (HBoV)s, which are associated with respiratory infections, have also frequently been detected in stool samples in cases of gastroenteritis, and a tentative association between HBoVs, and in particular type-2 HBoVs, and gastroenteritis has previously been made.

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Background: Rotaviruses are classified into G- and P-types, which are determined by the reactivity with antibodies to the outer viral proteins, VP7 and VP4, respectively, or sequence variation in the genes encoding these proteins. There are presently a number of different rotavirus strains co-circulating within the UK, with the common human strains G1P[8], G2P[4] and G9P[8] being the most prevalent. As part of strain surveillance for the European Rotavirus Network (EuroRotaNet) a cluster (n=29) of G8 strains was detected in the UK between February and May 2009.

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