Modelling incremental benefits on complications rates when targeting lower HbA1c levels in people with Type 2 diabetes and cardiovascular disease.

AIM: Glucose-lowering interventions in Type 2 diabetes mellitus have demonstrated reductions in microvascular complications and modest reductions in macrovascular complications. However, the degree to which targeting different HbA1c reductions might reduce risk is unclear. METHODS: Participant-level data for Trial Evaluating Cardiovascular Outcomes with Sitagliptin (TECOS) participants with established cardiovascular disease were used in a Type 2 diabetes-specific simulation model to quantify the likely impact of different HbA1c decrements on complication rates. Ten-year micro- and macrovascular rates were estimated with HbA1c levels fixed at 86, 75, 64, 53 and 42 mmol/mol (10%, 9%, 8%, 7% and 6%) while holding other risk factors constant at their baseline levels. Cumulative relative risk reductions for each outcome were derived for each HbA1c decrement. RESULTS: Of 5717 participants studied, 72.0% were men and 74.2% White European, with a mean (sd) age of 66.2 (7.9) years, systolic blood pressure 134 (16.9) mmHg, LDL-cholesterol 2.3 (0.9) mmol/l, HDL-cholesterol 1.13 (0.3) mmol/l and median Type 2 diabetes duration 9.6 (5.1-15.6) years. Ten-year cumulative relative risk reductions for modelled HbA1c values of 75, 64, 53 and 42 mmol/mol, relative to 86 mmol/mol, were 4.6%, 9.3%, 15.1% and 20.2% for myocardial infarction; 6.0%, 12.8%, 19.6% and 25.8% for stroke; 14.4%, 26.6%, 37.1% and 46.4% for diabetes-related ulcer; 21.5%, 39.0%, 52.3% and 63.1% for amputation; and 13.6%, 25.4%, 36.0% and 44.7 for single-eye blindness. CONCLUSIONS: These simulated complication rates might help inform the degree to which complications might be reduced by targeting particular HbA1c reductions in Type 2 diabetes.

The impact of social isolation on delayed hospital discharges of older hip fracture patients and associated costs.

UNLABELLED: Delayed discharges represent an inefficient use of acute hospital beds. Social isolation and referral to a public-funded rehabilitation unit were significant predictors of delayed discharges while admission from an institution was a protective factor for older hip fracture patients. Preventing delays could save between 11.2 and 30.7 % of total hospital costs for this patient group. INTRODUCTION: Delayed discharges of older patients from acute care hospitals are a major challenge for administrative, humanitarian, and economic reasons. At the same time, older people are particularly vulnerable to social isolation which has a detrimental effect on their health and well-being with cost implications for health and social care services. The purpose of the present study was to determine the impact and costs of social isolation on delayed hospital discharge. METHODS: A prospective study of 278 consecutive patients aged 75 or older with hip fracture admitted, as an emergency, to the Orthopaedics Department of Hospital Universitário de Santa Maria, Portugal, was conducted. A logistic regression model was used to examine the impact of relevant covariates on delayed discharges, and a negative binomial regression model was used to examine the main drivers of days of delayed discharges. Costs of delayed discharges were estimated using unit costs from national databases. RESULTS: Mean age at admission was 85.5 years and mean length of stay was 13.1 days per patient. Sixty-two (22.3 %) patients had delayed discharges, resulting in 419 bed days lost (11.5 % of the total length of stay). Being isolated or at a high risk of social isolation, measured with the Lubben social network scale, was significantly associated with delayed discharges (odds ratio (OR) 3.5) as was being referred to a public-funded rehabilitation unit (OR 7.6). These two variables also increased the number of days of delayed discharges (2.6 and 4.9 extra days, respectively, holding all else constant). Patients who were admitted from an institution were less likely to have delayed discharges (OR 0.2) with 5.5 fewer days of delay. Total costs of delayed discharges were between 11.2 and 30.7 % of total costs (€2352 and €9317 per patient with delayed discharge) conditional on whether waiting costs for placement in public-funded rehabilitation unit were included. CONCLUSION: High risk of social isolation, social isolation and referral to public-funded rehabilitation units increase delays in patients' discharges from acute care hospitals.

Impact of hip fracture on hospital care costs: a population-based study.

UNLABELLED: Using a large cohort of hip fracture patients, we estimated hospital costs to be £14,163 and £2139 in the first and second year following fracture, respectively. Second hip and non-hip fractures were major cost drivers. There is a strong economic incentive to identify cost-effective approaches for hip fracture prevention. INTRODUCTION: The purpose of this study was to estimate hospital costs of hip fracture up to 2 years post-fracture and compare costs before and after the index fracture. METHODS: A cohort of patients aged over 60 years admitted with a hip fracture in a UK region between 2003 and 2013 were identified from hospital records and followed until death or administrative censoring. All hospital records were valued using 2012/2013 unit costs, and non-parametric censoring methods were used to adjust for censoring when estimating average annual costs. A generalised linear model examined the main predictors of hospital costs. RESULTS: A cohort of 33,152 patients with a hip fracture was identified (mean age 83 years (SD 8.2). The mean censor-adjusted 1- and 2-year hospital costs after index hip fracture were £14,163 (95 % confidence interval (CI) £14,008 to £14,317) and £16,302 (95 % CI £16,097 to £16,515), respectively. Index admission accounted for 61 % (£8613; 95 % CI £8565 to £8661) of total 1-year hospital costs which were £10,964 higher compared to the year pre-event (p < 0.001). The main predictors of 1-year hospital costs were second hip fracture, other non-hip fragility fractures requiring hospitalisation and hip fracture-related complications. Total UK annual hospital costs associated with incident hip fractures were estimated at £1.1 billion. CONCLUSIONS: Hospital costs following hip fracture are high and mostly occur in the first year after the index hip fracture. Experiencing a second hip fracture after the index fracture accounted for much of the increase in costs. There is a strong economic incentive to prioritise research funds towards identifying the best approaches to prevent both index and subsequent hip fractures.

UKPDS outcomes model 2: a new version of a model to simulate lifetime health outcomes of patients with type 2 diabetes mellitus using data from the 30 year United Kingdom Prospective Diabetes Study: UKPDS 82.

AIMS/HYPOTHESIS: The aim of this project was to build a new version of the United Kingdom Prospective Diabetes Study (UKPDS) Outcomes Model (UKPDS-OM1), a patient-level simulation tool for predicting lifetime health outcomes of people with type 2 diabetes mellitus. METHODS: Data from 5,102 UKPDS patients from the 20 year trial and the 4,031 survivors entering the 10 year post-trial monitoring period were used to derive parametric proportional hazards models predicting absolute risk of diabetes complications and death. We re-estimated the seven original event equations and estimated new equations for diabetic ulcer and some second events. The additional data permitted inclusion of new risk factor predictors such as estimated GFR. We also developed four new equations for all-cause mortality. Internal validation of model predictions of cumulative incidence of all events and death was carried out and a contemporary patient-level dataset was used to compare 10 year predictions from the original and the new models. RESULTS: Model equations were based on a median 17.6 years of follow-up and up to 89,760 patient-years of data, providing double the number of events, greater precision and a larger number of significant covariates. The new model, UKPDS-OM2, is internally valid over 25 years and predicts event rates for complications, which are lower than those from the existing model. CONCLUSIONS/INTERPRETATION: The new UKPDS-OM2 has significant advantages over the existing model, as it captures more outcomes, is based on longer follow-up data, and more comprehensively captures the progression of diabetes. Its use will permit detailed and reliable lifetime simulations of key health outcomes in people with type 2 diabetes mellitus.

Individualised Estimation of Quality-adjusted Survival Benefit and Cost-effectiveness of Proton Beam Therapy in Intermediate-stage Hodgkin Lymphoma.

AIMS: Radiotherapy for Hodgkin lymphoma leads to the irradiation of organs at risk (OAR), which may confer excess risks of late effects. Comparative dosimetry studies show that proton beam therapy (PBT) may reduce OAR irradiation compared with photon radiotherapy, but PBT is more expensive and treatment capacity is limited. The purpose of this study is to inform the appropriateness of PBT for intermediate-stage Hodgkin lymphoma (ISHL). MATERIALS AND METHODS: A microsimulation model simulating the course of ISHL, background mortality and late effects was used to estimate comparative quality-adjusted life years (QALYs) lived and healthcare costs after consolidative pencil beam scanning PBT or volumetric modulated arc therapy (VMAT), both in deep-inspiration breath-hold. Outcomes were compared for 606 illustrative patients covering a spectrum of clinical presentations, varying by two age strata (20 and 40 years), both sexes, three smoking statuses (never, former and current) and 61 pairs of OAR radiation doses from a comparative planning study. Both undiscounted and discounted outcomes at 3.5% yearly discount were estimated. The maximum excess cost of PBT that might be considered cost-effective by the UK's National Institute for Health and Care Excellence was calculated. RESULTS: OAR doses, smoking status and discount rate had large impacts on QALYs gained with PBT. Current smokers benefited the most, averaging 0.605 undiscounted QALYs (range -0.341 to 2.171) and 0.146 discounted QALYs (range -0.067 to 0.686), whereas never smokers benefited the least, averaging 0.074 undiscounted QALYs (range -0.196 to 0.491) and 0.017 discounted QALYs (range -0.030 to 0.086). For the gain in discounted QALYs to be considered cost-effective, PBT would have to cost at most £4812 more than VMAT for current smokers and £645 more for never smokers. This is below preliminary National Health Service cost estimates of PBT over photon radiotherapy. CONCLUSION: In a UK setting, PBT for ISHL may not be considered cost-effective. However, the degree of unquantifiable uncertainty is substantial.

UK research expenditure on dementia, heart disease, stroke and cancer: are levels of spending related to disease burden?

BACKGROUND AND PURPOSE: A UK government review recommended that the impact of disease on the population and economy should be assessed to inform health research priorities. This study aims to quantify UK governmental and charity research funding for dementia, cancer, coronary heart disease (CHD) and stroke in 2007/08 and assess whether the levels of research expenditure are aligned with disease and economic burden. METHODS: We identified UK governmental agencies and charities providing health research funding and determined their levels of funding for dementia, cancer, CHD and stroke. Research funding levels were compared to the number of cases, disability-adjusted life years (DALYs) and economic burden. Economic costs were estimated using data on morbidity, mortality, health and social care use, private costs and other related indicators. RESULTS: Research funding to the four diseases was £833 million, of which £590 million (71%) was devoted to cancer, £169 million (20%) to CHD, £50 million (6%) to dementia and £23 million (4%) to stroke. Cancer received £482 in research funding per 1000 DALYs lost, CHD received £266, dementia received £166, with stroke receiving £71. In terms of economic burden, for every £1 million of health and social care costs attributable to each disease, cancer received £129 269 in research funding, CHD received £73 153, stroke received £8745 and dementia received £4882. CONCLUSIONS: Most health research funding in the UK is currently directed towards cancer. When compared to their burden, our analysis suggests that research spending on dementia and stroke is severely underfunded in comparison with cancer and CHD.

Estimation and external validation of a new prognostic model for predicting recurrence-free survival for early breast cancer patients in the UK.

BACKGROUND: We aimed to estimate and externally validate a new UK-specific prognostic model for predicting the long-term risk of a first recurrent event (local recurrence, metastatic recurrence, or second primary breast cancer) in women diagnosed with early breast cancer. METHODS: Using data on the prognostic characteristics and outcomes of 1844 women treated for early breast cancer at the Churchill Hospital in Oxford, parametric regression-based survival analysis was used to estimate a prognostic model for recurrence-free survival. The model, which incorporated established prognostic factors, was externally validated using independent data. Its performance was compared with that of the Nottingham Prognostic Index (NPI) and Adjuvant! Online. RESULTS: The number of positive axillary lymph nodes, tumour grade, tumour size and patient age were strong predictors of recurrence. Oestrogen receptor (ER) positivity was shown to afford a moderate protective effect. The model was able to separate patients into distinct prognostic groups, and predicted well at the patient level, mean Brier Accuracy Score=0.17 (s.e.=0.004) and overall C=0.745 (95% CI, 0.717-0.773). Its performance diminished only slightly when applied to a second independent data set. When compared with the NPI, the model was able to better discriminate between women with excellent and good prognoses, and it did not overestimate 10-year recurrence-free survival to the extent observed for Adjuvant! Online. CONCLUSION: The model estimated here predicts well at both the individual patient and group levels, and appears transportable to patients treated at other UK hospitals. Its parametric form permits long-term extrapolation giving it an advantage over other prognostic tools currently in use. A simple point scoring system and reference table allow 5-, 10-, and 15-year predictions from the model to be quickly and easily estimated. The model is also available to download as an interactive computer program.

An investigation into the performance of the Adjuvant! Online prognostic programme in early breast cancer for a cohort of patients in the United Kingdom.

BACKGROUND: Adjuvant! Online is an internet-based computer programme providing 10-year prognosis predictions for early breast cancer patients. It was developed in the United States, has been successfully validated in Canada, and is used in the United Kingdom and elsewhere. This study investigates the performance of Adjuvant! in a cohort of patients from the United Kingdom. METHODS: Data on the prognostic factors and management of 1065 women with early breast cancer diagnosed consecutively at the Churchill Hospital in Oxford between 1986 and 1996 were entered into Adjuvant! to generate predictions of overall survival (OS), breast cancer-specific survival (BCSS), and event-free survival (EFS) at 10 years. Such predictions were compared with the observed 10-year outcomes of these patients. RESULTS: For the whole cohort, Adjuvant! significantly overestimated OS (by 5.54%, P<0.001), BCSS (by 4.53%, P<0.001), and EFS (by 3.51%, P=0.001). For OS and BCSS, overestimation persisted across most demographic, pathologic, and treatment subgroups investigated. Differences between Adjuvant! predicted and observed EFS appeared smaller, and were significant for far fewer subgroups, only 5 out of the 28. The likely explanation for such discordance is that US breast cancer mortality rates (upon which Adjuvant! is based) appear to be systematically lower than breast cancer mortality rates in the United Kingdom. Differences in survival after recurrence would seem to be one contributory factor, with data suggesting that prognosis after relapse appears poorer in the United Kingdom. This may reflect the fact that new and more effective cancer drugs are often only approved for use in the United Kingdom many years after their adoption in the United States. CONCLUSION: The use of Adjuvant! by clinicians within the UK National Health Service is increasing, under the assumption that the programme is transferrable to the United Kingdom. At least for women treated for breast cancer at the Churchill Hospital in Oxford, however, Adjuvant!'s predictions were on the whole overoptimistic. If the findings reported here could be shown to be generalisable to other areas of the United Kingdom, then thought should perhaps be given to the development of a UK-specific version of the programme.

Requirement for activin A and transforming growth factor--beta 1 pro-regions in homodimer assembly.

Many proteins are initially synthesized as part of a large precursor. The role of the pro-region in the biosynthesis of transforming growth factor--beta 1 (TGF-beta 1) and activin A, two structurally related disulfide-linked homodimers synthesized as large precursors, was studied. Vectors that expressed either the pro-region or the mature regions of these molecules were used in complementation experiments, only when the pro-region was coexpressed with the mature region did intracellular dimerization and secretion of biologically active homodimers occur. The pro-regions of activin A and TGF-beta 1, therefore, aid the folding, disulfide bond formation, and export of their respective homodimers.

Cost-effectiveness analysis of a placebo-controlled randomized trial evaluating the effectiveness of arthroscopic subacromial decompression in patients with subacromial shoulder pain.

AIMS: The aims of this study were to compare the use of resources, costs, and quality of life outcomes associated with subacromial decompression, arthroscopy only (placebo surgery), and no treatment for subacromial pain in the United Kingdom National Health Service (NHS), and to estimate their cost-effectiveness. PATIENTS AND METHODS: The use of resources, costs, and quality-adjusted life-years (QALYs) were assessed in the trial at six months and one year. Results were extrapolated to two years after randomization. Differences between treatment arms, based on the intention-to-treat principle, were adjusted for covariates and missing data were handled using multiple imputation. Incremental cost-effectiveness ratios were calculated, with uncertainty around the values estimated using bootstrapping. RESULTS: Cumulative mean QALYs/mean costs of health care service use and surgery per patient from baseline to 12 months were estimated as 0.640 (standard error (se) 0.024)/£3147 (se 166) in the decompression arm, 0.656 (se 0.020)/£2830 (se 183) in the arthroscopy only arm and 0.522 (se 0.029)/£1451 (se 151) in the no treatment arm. Statistically significant differences in cumulative QALYs and costs were found at six and 12 months for the decompression versus no treatment comparison only. The probabilities of decompression being cost-effective compared with no treatment at a willingness-to-pay threshold of £20 000 per QALY were close to 0% at six months and approximately 50% at one year, with this probability potentially increasing for the extrapolation to two years. DISCUSSION: The evidence for cost-effectiveness at 12 months was inconclusive. Decompression could be cost-effective in the longer-term, but results of this analysis are sensitive to the assumptions made about how costs and QALYs are extrapolated beyond the follow-up of the trial.

The economic analyses of the UK prospective diabetes study.

An economic analysis was not initially included in the study design of the UK Prospective Diabetes Study (UKPDS). However, data were collected throughout the study on hospital drugs and medications used and these were supplemented near the end of the study by cross-sectional surveys of non-inpatient healthcare use and quality of life. Evaluations of tight vs. less tight blood pressure control, intensive vs. less conventional blood glucose control and metformin showed that each was highly cost-effective and that all could be provided at modest total cost. Further analyses showed that amputations and stroke had particularly severe consequences for quality of life, and that amputations and non-fatal MI had high cost consequences. Finally, patient-level data were used to construct a diabetes outcomes model, which estimates the probability of longer-term complications from patient-specific risk factors and can be used in populations at different stages of diabetes progression. The economic analyses arising from the UKPDS have provided new evidence to clinicians, policymakers and researchers on the consequences of diabetes and the cost-effectiveness of interventions, thereby assisting the development of treatment guidelines and improved standards of care. The analyses also illustrated a number of methodological innovations. Finally, the UKPDS Outcomes Model is gaining widespread acceptance as a validated tool for long-term economic and clinical prediction in diabetes.

Identification of a new member of the tumor necrosis factor family and its receptor, a human ortholog of mouse GITR.

The tumor necrosis factor (TNF) and TNF receptor (TNFR) gene superfamilies regulate diverse biological functions, including cell proliferation, differentiation, and survival [1] [2] [3]. We have identified a new TNF-related ligand, designated human GITR ligand (hGITRL), and its human receptor (hGITR), an ortholog of the recently discovered murine glucocorticoid-induced TNFR-related (mGITR) protein [4]. The hGITRL gene mapped to chromosome 1q23, near the gene for the TNF homolog Fas/CD95 ligand [5]. The hGITR gene mapped to chromosome 1p36, near a cluster of five genes encoding TNFR homologs [1] [6]. We found hGITRL mRNA in several peripheral tissues, and detected hGITRL protein on cultured vascular endothelial cells. The levels of hGITR mRNA in tissues were generally low; in peripheral blood T cells, however, antigen-receptor stimulation led to a substantial induction of hGITR transcripts. Cotransfection of hGITRL and hGITR in embryonic kidney 293 cells activated the anti-apoptotic transcription factor NF-kappaB, via a pathway that appeared to involve TNFR-associated factor 2 (TRAF2) [7] and NF-kappaB-inducing kinase (NIK) [8]. Cotransfection of hGITRL and hGITR in Jurkat T leukemia cells inhibited antigen-receptor-induced cell death. Thus, hGITRL and hGITR may modulate T lymphocyte survival in peripheral tissues.

Cost-effectiveness of a pragmatic structured education intervention for the prevention of type 2 diabetes: economic evaluation of data from the Let's Prevent Diabetes cluster-randomised controlled trial.

OBJECTIVES: Prevention of type 2 diabetes mellitus (TD2M) is a priority for healthcare systems. We estimated the cost-effectiveness compared with standard care of a structured education programme (Let's Prevent) targeting lifestyle and behaviour change to prevent progression to T2DM in people with prediabetes. DESIGN: Cost-effectiveness analysis alongside randomised controlled trial. SETTING: 44 general practices in Leicestershire, England. PARTICIPANTS: 880 participants with prediabetes randomised to receive either standard care or a 6-hour group structured education programme with follow-up sessions in a primary care setting. MAIN OUTCOME MEASURE: Incremental cost utility from the UK National Health Service (NHS) perspective. Quality of life and resource use measured from baseline and during the 36 months follow-up using the EuroQoL EQ-5D and 15D instruments and an economic questionnaire. Outcomes measured using quality-adjusted life years (QALYs) and healthcare costs calculated in 2012-2013 prices. RESULTS: After accounting for clustering and missing data, the intervention group was found to have a net gain of 0.046 (95% CI -0.0171 to 0.109) QALYs over 3 years, adjusted for baseline utility, at an additional cost of £168 (95% CI -395 to 732) per patient compared with the standard care group. The incremental cost-effectiveness ratio is £3643/QALY with an 86% probability of being cost-effective at a willingness to pay threshold of £20 000/QALY. CONCLUSIONS: The education programme had higher costs and higher quality of life compared with the standard care group. The Let's Prevent programme is very likely to be cost-effective at a willingness to pay threshold of £20 000/QALY gained. TRIAL REGISTRATION NUMBER: ISRCTN80605705.

Simultaneous adult T-cell leukemia/lymphoma and sub-acute polyneuropathy in a patient from Chile.

This paper reports a case of adult T-cell leukemia/lymphoma associated with human T-cell lymphotropic virus type I (HTLV-I) diagnosed in a Chilean patient who developed after 1 1/2 years a crisis with a progressive sensorimotor polyneuropathy. Serum and cerebrospinal fluid HTLV-I antibody tests were positive and HTLV-I DNA was clonally integrated in peripheral lymphocytes. This case is unusual in having simultaneous neurological disease. Along with other recent data from South America, this suggests that the endemic area of HTLV-I may spread far beyond the Caribbean area.

The involvement of the opioidergic system in the antinociceptive mechanism of action of antidepressant compounds.

1. Debate exists as to the nature of antidepressant-induced antinociception. It is unclear whether antidepressants are inherently antinociceptive, are able to potentiate opioid antinociception or both. We have used the acetic acid induced abdominal constriction assay in mice to investigate antidepressant-induced antinociception. 2. All the antidepressants tested (s.c.) produced dose-dependent protection against acetic acid-induced abdominal constriction. Similarly, morphine and aspirin were also effective antinociceptive agents in this nociceptive assay. 3. Opioid antagonists, naloxone (0.5 mg kg(-1), s.c.) and naltrindole (1 mg kg(-1), s.c.), shifted the dose-response relationships to the right for each of the antidepressant agents (dothiepin, amitriptyline, sibutramine, (+)-oxaprotiline and paroxetine). In this context the naloxone dose-ratios were 1.95, 3.90, 2.32, 4.50 and 2.65, with naltrindole dose-ratios of 4.36, 17.00, 4.28, 11.48 and 2.65 were obtained, respectively. Naloxone also shifted the morphine dose-response relationship to the right, by a factor of 2.62, whilst naltrindole had no effect upon morphine antinociception. Aspirin antinociception remained unaffected by both opioid antagonists. 4. The enkephalin catabolism inhibitor acetorphan, by itself, produced no activity in this test at a dose of 10 mg kg(-1) (s.c.). However, at higher doses, acetorphan produced a linear dose-response relationship against acetic acid-induced abdominal constriction. 5. When acetorphan was administered before either the antidepressants or morphine, there was a clear potentiation of the antidepressant- or morphine-induced antinociception. However, acetorphan had no effect on aspirin antinociception. 6. Since neither of the opioid antagonists were able to attenuate, nor was acetorphan able to potentiate, aspirin antinociception, we concluded that the mechanism of antidepressant-induced antinociception is different from that of the non-steroidal anti-inflammatory drugs. 7. These data are consistent with the view that antidepressants may induce endogenous opioid peptide release, as shown by the acetorphan study. In this context, the ability of naltrindole to displace the antidepressant dose-response relationship to the right without affecting morphine antinociception, implicates the delta-opioid receptor and endogenous opioid peptides in antidepressant-induced antinociception.

Insulin-secreting activity of the traditional antidiabetic plant Viscum album (mistletoe).

Viscum album (mistletoe) has been documented as a traditional treatment of diabetes. In acute 20-min tests, 1-10 mg/ml aqueous extract of mistletoe evoked a stepwise 1.1- to 12.2-fold stimulation of insulin secretion from clonal pancreatic B-cells. This effect was abolished by 0.5 mM diazoxide and prior exposure to extract did not alter subsequent stimulation of insulin secretion induced by 10 mM L-alanine, thereby negating a detrimental effect on cell viability. The insulin-releasing effect of mistletoe extract was unaltered by 16.7 mM glucose, l-alanine (10 mM), 3-isobutyl-1-methylxanthine (IBMX) (1 mM), or a depolarising concentration of KCl (25 mM). The ability of extract to enhance insulin secretion did not depend upon the use of heat during extract preparation and was not mediated by lectins. These results demonstrate the presence of insulin-releasing natural product(s) in Viscum album which may contribute to the reported antidiabetic property of the plant.

Insulin-releasing and insulin-like activity of Agaricus campestris (mushroom).

Agaricus campestris (mushroom) has been documented as a traditional treatment for diabetes. Here the administration of mushroom in the diet (62.5 g/kg) and drinking water (2.5 g/l) countered the hyperglycaemia of streptozotocin-diabetic mice. An aqueous extract of mushroom (1 mg/ml) stimulated 2-deoxyglucose transport (2.0-fold), glucose oxidation (1.5-fold) and incorporation of glucose into glycogen (1.8-fold) in mouse abdominal muscle. In acute 20 min tests, 0.25-1 mg/ml aqueous extract of mushroom evoked a stepwise 3.5- to 4.6-fold stimulation of insulin secretion from the BRIN-BD11 pancreatic B-cell line. This effect was abolished by 0.5 mM diazoxide and prior exposure to extract did not affect subsequent stimulation of insulin secretion by 10 mM L-alanine, thereby negating a detrimental effect on cell viability. The effect of extract was potentiated by 16.7 mM glucose, L-alanine (10 mM) and IBMX (1 mM), and a depolarising concentration of KCl (25 mM) did not augment the insulin-releasing activity of mushroom. Activity of the extract was found to be heat stable, acetone soluble and unaltered by exposure to alkali, but decreased with exposure to acid. Dialysis to remove components with molecular mass < 2000 Da caused a 40% reduction in activity. Sequential extraction with solvents revealed insulin-releasing activity to be greatest in polar fractions. Lack of haemagglutinin activity with extract activity indicated that activity was unlikely to be due to a lectin-mediated event. These results demonstrate the presence of antihyperglycaemic, insulin-releasing and insulin-like activity in A. campestris.

Gastric inhibitory polypeptide and effects of glycation on glucose transport and metabolism in isolated mouse abdominal muscle.

This study investigates the effects of gastric inhibitory polypeptide (GIP) and glycated GIP (glucitol adduct of GIP) on glucose uptake and metabolism in muscle. Glycated GIP (molecular mass 5147.2 Da) was purified by HPLC following in vitro incubation under hyperglycaemic reducing conditions (24 h at pH 7.4). GIP (10(-10)-10(-8) mol/l) significantly stimulated (1.4- to 1.5-fold, P < 0.001) 2-deoxy-D-[1-3H]glucose uptake in abdominal muscle pieces from 3- to 5-week-old lean mice compared with control incubations (without GIP). This stimulatory effect on glucose uptake at 10(-10)-10(-9) mol/l was decreased by 13-20% following glycation of the peptide (P < 0.05). GIP (10(-9) and 10(-8) mol/l) induced a stepwise 1.4- to 1.7-fold increase (P < 0.01, P < 0.001 respectively) in [14C]glucose oxidation compared with controls. This effect on glucose oxidation was diminished by 32% with 10(-8) mol/l glycated GIP (P < 0.05). GIP (10(-9) and 10(-8) mol/l) induced a 1.4- to 1.8-fold increase in [14C]glucose incorporation into muscle glycogen (glycogenesis) compared with controls. Glycated GIP (10(-8) mol/l) exhibited a 41% decrease in glycogenic activity (P < 0.01). GIP (10(-10)-10(-8) mol/l) stimulated lactate production in isolated abdominal muscle (1.2- to 1.3-fold, P < 0.05); however glycated GIP did not exert a significant effect. This study demonstrates for the first time that GIP promotes glucose uptake, glucose oxidation and glycogenesis in muscle tissue. Furthermore, modification of GIP through glycation diminishes its biological effectiveness.

Genetic variants of HIV-1 in Thailand.

Serosurveys conducted prior to 1988 indicated a very low level of HIV-1 infection in Thailand, even among high-risk groups. The Ministry of Health has reported a dramatic increase in HIV-1 infection during the last three years. The geographic and demographic distribution of the epidemic is broad, involving multiple provinces and risk groups. Foci of higher incidence and prevalence have been noted in the urban center of Bangkok and in the northern provinces of Chiang Mai and Chiang Rai. Here we report the results of genetic characterization of 16 HIV-1 isolates from Thailand using a combination of polymerase chain reaction (PCR) typing and DNA sequencing. The complete sequence of gp160 (env) of five isolates, partial env sequence of six additional isolates, and the gag gene of two isolates were determined. Two highly distinct HIV-1 variants were found. One variant resembled those prevalent in North America and Europe; five of the isolates were of this type. The remaining eleven isolates were very similar to one another and represented a variant unlike any previously described. Phylogenetic tree analysis of complete env and gag genes placed the two variants on widely separated branches. Protein sequence comparisons indicate both general and specific features that distinguish the Northern Thailand variant both from the Bangkok variant and from virtually all previously sequenced HIV-1 isolates. A simple PCR test for distinguishing the two variants has been developed for use in epidemiologic surveys.