90 research outputs found

    Recruitment of VPS33A to HOPS by VPS16 Is Required for Lysosome Fusion with Endosomes and Autophagosomes.

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    The mammalian homotypic fusion and vacuole protein sorting (HOPS) complex is comprised of six subunits: VPS11, VPS16, VPS18, VPS39, VPS41 and the Sec1/Munc18 (SM) family member VPS33A. Human HOPS has been predicted to be a tethering complex required for fusion of intracellular compartments with lysosomes, but it remains unclear whether all HOPS subunits are required. We showed that the whole HOPS complex is required for fusion of endosomes with lysosomes by monitoring the delivery of endocytosed fluorescent dextran to lysosomes in cells depleted of individual HOPS proteins. We used the crystal structure of the VPS16/VPS33A complex to design VPS16 and VPS33A mutants that no longer bind each other and showed that, unlike the wild-type proteins, these mutants no longer rescue lysosome fusion with endosomes or autophagosomes in cells depleted of the endogenous proteins. There was no effect of depleting either VIPAR or VPS33B, paralogs of VPS16 and VPS33A, on fusion of lysosomes with either endosomes or autophagosomes and immunoprecipitation showed that they form a complex distinct from HOPS. Our data demonstrate the necessity of recruiting the SM protein VPS33A to HOPS via its interaction with VPS16 and that HOPS proteins, but not VIPAR or VPS33B, are essential for fusion of endosomes or autophagosomes with lysosomes.We thank Folma Buss and David Tumbarello for HeLaM cells stably expressing mRFP-GFP-LC3, Reiner Schulte and Michal Maj for help with FACS analysis, Sally Gray for technical assistance and David Owen for discussing experiments and critical reading of the manuscript. L. W. was supported by European Molecular Biology Organization (EMBO) and Federation of the Societies of Biochemistry and Molecular Biology (FEBS) Long-Term Fellowships, S. C. G. by a Sir Henry Dale Fellowship jointly funded by the Wellcome Trust and the Royal Society (grant: 098406/Z/12/Z) and U. G. is a Marie Skłodowska-Curie fellow. The work was funded by UK Medical Research Council programme grant to J. P. L. (G0900113) and the Cambridge Institute for Medical Research is supported by a Wellcome Trust Strategic Award (100140). The Zeiss LSM710 confocal system and the Thermo(Cellomics) ArrayScan™ VTi High Content Screening Microscope (Cellomics) were purchased with Wellcome Trust support (grants: 079919 and 093026).This is the final version of the article. It first appeared from Wiley via http://dx.doi.org/10.1111/tra.1228

    Brief Lifestyle Interventions for Prediabetes in Primary Care:A Service Evaluation

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    BACKGROUND: The increasing number of cases of prediabetes in the UK is concerning, particularly in Wales where there is no standard programme of support. The aim of the current service evaluation was to examine the effectiveness of brief lifestyle interventions on glucose tolerance in people at risk of developing type 2 diabetes. METHODS: In this pragmatic service evaluation clinical data on people deemed at risk of developing type 2 diabetes were evaluated from two GP clusters. Patients (n = 1207) received a single 15 to 30-min, face-to-face, consultation with a health care practitioner. Interventions were assessed by changes in HbA1c and distribution across the HbA1c ranges 12 months following intervention. Statistical significance of reversion to normoglycaemia and development of diabetes were assessed through comparison with expected rates without intervention. RESULTS: Between baseline and 12-month follow-up HbA1c fell from 43.85 ± 1.57 mmol/mol (6.16 ± 0.14%) to 41.63 ± 3.84 mmol/mol (5.96 ± 0.35%), a decrease of 2.22 mmol/mol (0.20%) (95% CI 2.01 (0.18%), 2.42 (0.22%); p < 0.0001). The proportion of people with normal glucose tolerance at 12 months (0.50 95%CI 0.47, 0.52) was significantly larger than the lower (0.06 (p < 0.0001) and the upper (0.19 (p < 0.0001)) estimates based on no intervention. CONCLUSION: Results indicate significant improvement in glucose tolerance across GP clusters. The brief intervention has the potential to offer a robust and effective option to support people at risk of developing type 2 diabetes. Further research in the form of a randomised trial is needed to confirm this and identify those likely to benefit most from this intervention

    Microwave Noninvasive Blood Glucose Monitoring Sensor: Penetration Depth and Sensitivity Analysis

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    Previously reported clinical performances of microwave noninvasive blood glucose monitoring sensor look promising. It is clear that dielectric properties are changing when the food intake takes place, but the exact physiological mechanism is not clear. In an attempt to figure out the physiological mechanism of microwave noninvasive blood glucose monitoring sensor, this paper presents a series of studies to find out a) the penetration depth of the microwave resonator-based sensor and b) the effect of permittivity variation of human tissues on the microwave resonator parameters

    Diabetic Retinopathy in Newly Diagnosed Subjects With Type 2 Diabetes Mellitus: Contribution of β-Cell Function

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    Purpose: The association of hyperglycemia and diabetic retinopathy (DR) in established type 2 diabetes mellitus (T2DM) subjects is well accepted. However, the association between β-cell responsiveness and insulin sensitivity leading to fasting and postprandial hyperglycemia with DR in newly diagnosed treatment-naïve T2DM subjects remain unreported. Methods: A total of 544 newly diagnosed treatment-naïve T2DM subjects were screened for DR (digital photography) and underwent a standardized meal tolerance test. Serial plasma glucose and insulin levels were measured, and fasting (M0) and postprandial β-cell responsiveness calculated Calculating Pancreatic Response Program along with homeostasis model assessment-β cell function (HOMA-B) and HOMA-Insulin Sensitivity. A subgroup of 201 subjects also underwent a frequently sampled IV glucose tolerance test and the acute insulin response to glucose, insulin sensitivity, and glucose effectiveness (SG) estimated (MINMOD model). Results: A total of 16.5% (90) subjects had DR at diagnosis. Subjects with DR had significantly reduced M0, HOMA-B and SG leading to higher fasting and postprandial (2 hour) glucose and significantly lower fasting and postprandial (2 hour) insulin. Factors independently associated with DR in multivariate logistic regression analysis were M0, HOMA-B, and SG with fasting and postprandial (2 hour) glucose and insulin. There was no statistical difference in glycated hemoglobin, systolic blood pressure, acute insulin response to glucose, and insulin sensitivity between those with or without DR. Principal Conclusions: In this cohort of newly diagnosed T2DM subjects, DR is associated with reduced β-cell responsiveness, resulting from β-cell failure rather than insulin resistance, leading to fasting and postprandial hyperglycemia and hypoinsulinemi

    Identifying all persons in Wales with type 1 diabetes mellitus using routinely collected linked data

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    Introduction Type 1 diabetes mellitus (T1DM) is an autoimmune condition characterised by hyperglycaemia, caused by the destruction of insulin producing β-cells in the pancreas. Previous epidemiological population level studies of T1DM and its complications have typically used recorded T1DM diagnoses to determine diabetes status and define cohorts. Objectives and Approach The objective was to identify all persons with T1DM in Wales from Primary (~70\% population coverage) and Secondary Care (100% coverage) data held in the Secure Anonymised Information Linkage (SAIL) databank. People with a coded T1DM diagnosis (using Read codes in Primary Care data and International Classification of Disease (ICD10) codes in Secondary Care data), plus either insulin prescribed shortly after diagnosis or a hospital admission for diabetic ketoacidosis were identified as having T1DM. A sub-group of this SAIL e-cohort were validated using a register of persons diagnosed with T1DM in Wales under 15 years old (Brecon cohort). Results 18,285 people had a T1DM diagnosis and 10,539 had more T1DM than type 2 diabetes mellitus (T2DM) diagnoses. 6,375 persons were identified with T1DM in Primary Care data using our criteria, with a median diagnosis age of 19.2 years (interquartile range 11.0, 35.5). 47.5\% were diagnosed under 18 years of age. 39.6% of people with a T1DM diagnosis did not have T1DM using our criteria. False positive and negative rates of 4.8% and 4.5% respectively were achieved by comparing persons in the SAIL e-cohort against the Brecon cohort. Clinician estimated false positive and negative rates were 1.4% and 3.9% respectively. The prevalence of T1DM in Wales in 2016 was 0.37% or 11,049 people. Conclusion/Implications Our criteria for identifying people with T1DM was more reliable than using diagnosis codes alone, allowing for a more accurate, efficient and reproducible means of identifying individuals with T1DM for researchers utilising the SAIL databank, and other national health repositories

    Can HbA1c detect undiagnosed diabetes in acute medical hospital admissions?

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    Objective: to study hyperglycaemia in acute medical admissions to Irish regional hospital.Research design and methods: from 2005 to 2007, 2061 white Caucasians, aged &gt;18 years, were admitted by 1/7 physicians. Those with diabetes symptoms/complications but no previous record of hyperglycaemia (n = 390), underwent OGTT with concurrent HbA1c in representative subgroup (n = 148). Comparable data were obtained for 108 primary care patients at risk of diabetes.Results: diabetes was diagnosed immediately by routine practice in 1% (22/2061) [aged 36 (26–61) years (median IQ range)/55% (12/22) male] with pre-existing diabetes/dysglycaemia present in 19% (390/2061) [69 (58–80) years/60% (235/390) male].Possible diabetes symptoms/complications were identified in 19% [70 (59–79) years/57% (223/390) male] with their HbA1c similar to primary care patients [54 (46–61) years], 5.7 (5.3–6.0)%/39 (34–42) mmol/mol (n = 148) vs 5.7 (5.4–6.1)%/39 (36–43) mmol/mol, p = 0.35, but lower than those diagnosed on admission, 10.2 (7.4–13.3)%/88 (57–122) mmol/mol, p &lt; 0.001. Their fasting plasma glucose (FPG) was similar to primary care patients, 5.2 (4.8–5.7) vs 5.2 (4.8–5.9) mmol/L, p = 0.65, but 2hPG higher, 9.0 (7.3–11.4) vs 5.5 (4.4–7.5), p &lt; 0.001.HbA1c identified diabetes in 10% (15/148) with 14 confirmed on OGTT but overall 32% (48/148) were in diabetic range on OGTT. The specificity of HbA1c in 2061 admissions was similar to primary care, 99% vs 96%, p = 0.20, but sensitivity lower, 38% vs 93%, p &lt; 0.001 (63% on FPG/23% on 2hPG, p = 0.037, in those with possible symptoms/complications).Conclusion: HbA1c can play a diagnostic role in acute medicine as it diagnosed another 2% of admissions with diabetes but the discrepancy in sensitivity shows that it does not reflect transient/acute hyperglycaemia resulting from the acute medical event.</p

    Prevalence of admission plasma glucose in 'diabetes' or 'at risk' ranges in hospital emergencies with no prior diagnosis of diabetes by gender, age and ethnicity

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    Aims To establish the prevalence of admission plasma glucose in 'diabetes' and 'at risk' ranges in emergency hospital admissions with no prior diagnosis of diabetes; characteristics of people with hyperglycaemia; and factors influencing glucose measurement. Methods Electronic patient records for 113 097 hospital admissions over 1 year from 2014 to 2015 included 43 201 emergencies with glucose available for 31 927 (74%) admissions, comprising 22 045 people. Data are presented for 18 965 people with no prior diagnosis of diabetes and glucose available on first attendance. Results Three quarters (14 214) were White Europeans aged 62 (43-78) years, median (IQ range); 12% (2241) South Asians 46 (32-64) years; 9% (1726) Unknown/Other ethnicities 43 (29-61) years; and 4% (784) Afro-Caribbeans 49 (33-63) years,  24 hours. Conclusions Hyperglycaemia was evident in 21% of adults admitted as an emergency; various aspects related to follow-up and initial testing, age and ethnicity need to be considered by professional bodies addressing undiagnosed diabetes in hospital admissions

    Comparison of the effects of three insulinotropic drugs on plasma insulin levels after a standard meal

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    WSTĘP. Porównanie działania repaglinidu, glipizydu i glibenklamidu na wydzielanie insuliny i glukozy po posiłku próbnym zawierającym 500 kcal. MATERIAŁ I METODY. Do krzyżowej, randomizowanej, podwójnie ślepej próby zakwalifikowano 12 pacjentów z wczesną cukrzycą typu 2 (średnia wartość HbA1c 6,1%) oraz 12 osób jako grupę kontrolną. Chorzy losowo otrzymali placebo, 2 mg repaglinidu, 5 mg glipizydu i 5 mg glibenklamidu. Leki podawano po wzorcowym posiłku próbnym, zawierającym 500 kcal. Badania kolejnych leków wykonywano po okresie wydalania poprzedniego z organizmu (7&#8211;12 dni). WYNIKI. Wszystkie trzy leki miały jednakowy wpływ na całkowite posiłkowe wydzielanie insuliny (pole pod krzywą [AUC, area under the curve] -15-240 min). Zauważono jednak wyraźne różnice we wczesnym wydzielaniu insuliny (AUC -15-30 min): u badanych bez cukrzycy zarówno repaglinid, jak i glipizyd zwiększały wydzielanie insuliny odpowiednio o około 61 i 34% w porównaniu z placebo. Wśród chorych na cukrzycę różnica ta wynosiła odpowiednio 37 i 47%. W obu grupach stwierdzono istotną różnicę między glipizydem a glibenklamidem, natomiast repaglinid był skuteczniejszy niż glibenklamid tylko wśród zdrowych pacjentów bez cukrzycy. Wszystkie leki skutecznie obniżały całkowite stężenie glukozy AUC u chorych na cukrzycę i bez niej. Jednak wśród badanych bez cukrzycy repaglinid okazał się znamiennie skuteczniejszy niż glibenklamid. Różnicy takiej nie stwierdzono u chorych na cukrzycę, prawdopodobnie ze względu na częstsze występowanie insulinooporności w tej grupie. WNIOSKI. Repaglinid i glipizyd, ale nie glibenklamid, znacząco poprawiły wczesne wydzielanie insuliny po standardowym posiłku, zarówno wśród badanych bez cukrzycy, jak i wśród chorych na cukrzycę z zachowaną funkcją komórek b trzustki.INTRODUCTION. To compare the effects of repaglinide, glipizide, and glibenclamide on insulin secretion and postprandial glucose after a single standard 500-kcal test meal. MATERIAL AND METHODS. A total of 12 type 2 diabetic patients with early diabetes (mean HbA1c of 6.1%) and 12 matched control subjects were enrolled in this randomized, double-blind, crossover trial. Subjects received placebo, 2 mg repaglinide, 5 mg glipizide, and 5 mg glibenclamide in a random fashion during the trial. Administration of each drug was followed by a single standard 500-kcal test meal. A washout period of 7&#8211;12 days existed between the four study visits. RESULTS. All three drugs were equally effective on the total prandial insulin secretion (area under the curve [AUC] &#8211;15 to 240 min). However, clear differences were noted in the early insulin secretion (AUC &#8211;15 to 30 min); both repaglinide and glipizide increased secretion in nondiabetic subjects by ~61 and 34%, respectively, compared with placebo. In the diabetic patients, the difference versus placebo was 37 and 47%, respectively. The difference between glipizide and glibenclamide reached significance in both groups of subjects, whereas repaglinide was more effective than glibenclamide only in the healthy nondiabetic subject group. All three drugs were effective in decreasing total glucose AUC in the nondiabetic and diabetic population. In the nondiabetic subjects, however, repaglinide was significantly more effective than glibenclamide. The differences disappeared in the diabetic subjects, probably as a result of increased prevalence of insulin resistance in this group. CONCLUSIONS. Repaglinide and glipizide but not glibenclamide significantly enhanced the early insulin secretion in both nondiabetic and diabetic subjects with preserved b-cell function after a single standard meal

    A retrospective epidemiological study of Type 1 Diabetes Mellitus in Wales, UK between 2008 and 2018

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    Introduction Studies of prevalence and the demographic profile of type 1 diabetes are challenging because of the relative rarity of the condition, however, these outcomes can be determined using routine healthcare data repositories. Understanding the epidemiology of type 1 diabetes allows for targeted interventions and care of this life-affecting condition. Objectives To describe the prevalence, incidence and demographics of persons with type 1 diabetes diagnosed in Wales, UK, using the Secure Anonymised Information Linkage (SAIL) Databank. Methods Data derived from primary and secondary care throughout Wales available in the SAIL Databank were used to identify people with type 1 diabetes to determine the prevalence and incidence of type 1 diabetes over a 10 year period (2008–18) and describe the demographic and clinical characteristics of this population by age, socioeconomic deprivation and settlement type. The seasonal variation in incidence rates was also examined. Results The prevalence of type 1 diabetes in 2018 was 0.32% in the whole population, being greater in men compared to women (0.35% vs 0.28% respectively); highest in those aged 15-29 years (0.52%) and living in the most socioeconomically deprived areas (0.38%). The incidence of type 1 diabetes over 10 years was 14.0 cases/100,000 people/year for the whole population of Wales. It was highest in children aged 0-14 years (33.6 cases/100,000 people/year) and areas of high socioeconomic deprivation (16.8 cases/100,000 people/year) and least in those aged 45-60 years (6.5 cases/100,000 people/year) and in areas of low socioeconomic deprivation (11.63 cases/100,000 people/year). A seasonal trend in the diagnoses of type 1 diabetes was observed with higher incidence in winter months. Conclusion This nation-wide retrospective epidemiological study using routine data revealed that the incidence of type 1 diabetes in Wales was greatest in those aged 0-14 years with a higher incidence and prevalence in the most deprived areas. These findings illustrate the need for health-related policies targeted at high deprivation areas to include type 1 diabetes in their remit

    Portal technologies for patient-centred integrated care

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    Integrated care pathways (ICP) are increasingly used in clinical settings to provide more effective care to patients. ICPs form part of local working agreements to assist co-ordination of multi-disciplinary teams to deliver evidence-based care plans to individual patients. They also document the expected progress of specific patient groups as part of clinical records. To anticipate increased use of ICPs, we have developed Healthcare@Home, a research-phase demonstrator for improving integration of information along the patient path. Healthcare@Home includes support for at-home, in-clinic and mobile wireless sensor devices feeding patient-proximal data hubs, timeline-based physiological trend analysis, data aggregation/dashboarding and individualised risk stratification. These and other decision support tools are embedded in portal designs supporting 'end-to-end' workflows as focused by the composite needs of a National Service Framework (NSF) for patients with diabetes. Healthcare@Home thus represents a scaleable, extensible personalised healthcare information system driven directly from national policy on disease early detection and prevention. Individual portlets have been mapped to stages in the ICP. The portal technologies employed, running on PCs, mobile phones or TVs are capable of highly cost-effective 'end-to-end, anywhere-to-anywhere' information integration
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