National survey of the management of Diabetic Ketoacidosis (DKA) in the UK in 2014.

AIM: To examine, in a national survey, the outcomes of adult patients presenting with DKA in 2014, mapped against accepted UK national guidance. METHODS: Data were collected in a standardized form covering clinical and biochemical outcomes, risk and discharge planning. The form was sent to all UK diabetes specialist teams (n = 220). Anonymized data were collected on five consecutive patients admitted with DKA between 1 May 2014 and 30 November 2014. RESULTS: A total of 283 forms were received (n = 281 patients) from 72 hospitals, of which 71.4% used the national guidelines. The results showed that 7.8% of cases occurred in existing inpatients, 6.1% of admissions were newly diagnosed diabetes and 33.7% of patients had had at least one episode of DKA in the preceding year. The median times to starting 0.9% sodium chloride and intravenous insulin were 41.5 and 60 min, respectively. The median time to resolution was 18.7 h and the median length of hospital stay was 2.6 days. Significant adverse biochemical outcomes occurred, with 27.6% of patients developing hypoglycaemia and 55% reported as having hypokalaemia. There were also significant issues with care processes. Initial nurse-led observations were carried out well, but subsequent patient monitoring remained suboptimal. Most patients were not seen by a member of the diabetes specialist team during the first 6 h, but 95% were seen before discharge. A significant minority of discharge letters to primary care did not contain necessary information. CONCLUSION: Despite widespread adoption of national guidance, several areas of management of DKA are suboptimal, being associated with avoidable biochemical and clinical risk.

Determining in-patient diabetes treatment satisfaction in the UK--the DIPSat study.

AIMS: To measure in-patient diabetes treatment satisfaction and its relationship to in-patient diabetes care. METHODS: In a cross-sectional study, diabetes in-patient specialist nurses at 58 UK hospitals asked insulin-treated in-patients with diabetes to complete the recently updated Diabetes Treatment Satisfaction Questionnaire for In-patients and a general questionnaire; 1319 in-patients completed these questionnaires. RESULTS: Satisfaction with the general diabetes treatment items in the Diabetes Treatment Satisfaction Questionnaire for In-patients was high, but there were high levels of extreme dissatisfaction with meal choices, meal quality and lack of similarity of hospital meals to normal domestic choices--23% would never or rarely have made similar meal choices at home. Hyperglycaemia or hypoglycaemia was reported for much of the in-patient stay (20% and 7%, respectively) and 26% reported at least one severe hypoglycaemic episode; these groups had lower satisfaction with the timing of medication in relation to meals (P < 0.003). More frequent in-patient hyperglycaemia or hypoglycaemia were associated with significantly poorer overall satisfaction scores and negative well-being scores (both P < 0.0001). Previous experience of a multiple daily insulin injection regimen was associated with more dissatisfaction than other regimens (P < 0.01). Multiple regression models explained 36% of variability in overall treatment satisfaction, with most (22.4%) accounted for by satisfaction with time spent with a diabetes in-patient specialist nurse (P < 0.0001). Self-administration of insulin was independently associated with higher treatment satisfaction (P < 0.006) in this model. CONCLUSIONS: The DIPSat programme describes the complex relationships between diabetes in-patient treatment satisfaction and in-patient diabetes care.

Use of haemoglobin A1c to detect impaired fasting glucose or Type 2 diabetes in a United Kingdom community based population.

AIMS: To evaluate the diagnostic accuracy of haemoglobin A1c (HbA1c) in screening for impaired fasting glucose and Type 2 diabetes (T2DM). METHODS: We screened 3904 adults aged 45-70 (mean age 58.6 [standard deviation (SD) 6.9] years, mean body mass index (BMI) 29.9 [SD 4.7]kg/m(2)), with fasting plasma glucose (FPG) and HbA1c as part of a large diabetes prevention programme. We assessed the diagnostic accuracy of HbA1c for predicting impaired fasting glucose (IFG), (defined either as FPG 5.6-6.9 mmol/l, or 6.1-6.9 mmol/l), and T2DM (FPG ≥ 7.0 mmol/l). RESULTS: The prevalences of IFG were 13.8% (FPG 5.6-6.9 mmol/l) and 4.5% (FPG 6.1-6.9 mmol/l) and of T2DM was 2.1%. Using FPG 5.6-6.9 mmol/l as the IFG reference standard, HbA1c of 39-47 mmol/mol (5.7-6.4%) was 63% sensitive and 81% specific, and HbA1c 43-47 mmol/mol (6.1-6.4%) was 21% sensitive and 98% specific, in diagnosing IFG. HbA1c ≥ 48 mmol/mol (6.5%) was 61% sensitive and 99% specific in diagnosing T2DM. Having HbA1c 39-47 mmol/mol (5.7-6.4%), male sex, and body mass index >29.5 together increased the odds of IFG 6.5-fold (95% confidence interval (CI) 5.5-7.8) compared to the pre-test odds. CONCLUSION: Defining 'pre-diabetes' at a lower HbA1c threshold of 39 mmol/mol (5.7%) instead of 47 mmol/mol (6.1%) increases its sensitivity in diagnosing IFG, but current American Diabetes Association definitions of 'pre-diabetes' based on HbA1c would fail to detect almost 40% of people currently classified as IFG. This has implications for current and future diabetes prevention programmes, for vascular risk management, and for clinical advice given to people with 'pre-diabetes' based on fasting glucose data.

Cord blood telomere length, telomerase activity and inflammatory markers in pregnancies in women with diabetes or gestational diabetes.

AIMS: We tested the hypothesis that diabetes during pregnancy leads to chromosomal DNA damage and telomere attrition in the feto placental unit and cord blood, and provides evidence for intrauterine programming towards a senescent phenotype in the offspring. METHODS: We obtained cord blood from pregnant women with pregestational Type 1 diabetes (n=26), Type 2 diabetes (n=20) or gestational diabetes (n=71), and control subjects without diabetes (n=45, n=76 and n=81, respectively) matched for maternal and gestational age. We measured cord blood mononuclear cell telomere length, telomerase activity (a reverse transcriptase that limits telomere attrition), and concentrations of insulin, high-sensitivity C-reactive protein (hs-CRP) and soluble intercellular adhesion molecule-1 (sICAM-1). RESULTS: We found no significant differences between groups in cord blood telomere length in any nucleated cell type, or in hs-CRP or sICAM-1 concentrations, but telomerase activity was higher in cord blood from Type 1 (P<0.05) and gestational diabetes pregnancies (P<0.05), but not in Type 2 diabetes pregnancies. There were no significant relationships between glycaemic control, cord blood telomere length, telomerase activity or inflammatory markers in any group. CONCLUSIONS: We found no difference in cord blood telomere length in pregnancies of women with diabetes compared with control subjects, but higher cord blood telomerase activity in Type 1 and gestational diabetes. This may reflect upregulated telomere reverse transcriptase in response to in utero oxidative DNA and telomere damage. These observations are relevant to the hypothesis that diabetes during pregnancy leads to in utero preprogramming towards senescence in the offspring.

Psychometric validation and use of a novel diabetes in-patient treatment satisfaction questionnaire.

AIMS: To develop the first psychometrically validated Diabetes Treatment Satisfaction Questionnaire for in-patients (DTSQ-IP) and examine determinants of in-patient diabetes treatment satisfaction. METHODS: We studied 366 in-patients with insulin-treated diabetes at a single UK centre. We developed a 19-item DTSQ-IP to assess in-patient diabetes treatment satisfaction, and collected data on in-patient length of stay (LOS) and in-patient care at the same time. RESULTS: Psychometric analyses including Principal Components Analysis and Cronbach's alpha reliability coefficient showed that a single satisfaction score (excluding two items scored individually) can be computed for the entire DTSQ-IP, indicating very good internal consistency reliability (0.92). The DTSQ-IP detected considerable dissatisfaction with meal choice and timing (13.7% of in-patients would never have chosen similar meals at home), and with in-patient hypoglycaemia (35.3% felt that their blood glucose was too low most of the time). In-patients on surgical wards, women, and those long established on insulin were significantly more dissatisfied, particularly with competence of hospital staff. Patients who administered their own insulin were not significantly less dissatisfied overall, but were so with the choice of meals (P = 0.005). Multiple regression analysis produced a model accounting for 8.2% of variability in DTSQ-IP (r = 0.29; P = 0.0058) and 21.7% of variability in LOS (r = 0.46; P = 0.0001). CONCLUSIONS: The DTSQ-IP is a novel, psychometrically validated and sensitive tool that adds to the DTSQ portfolio. The DTSQ-IP facilitates efforts to assess and improve treatment satisfaction in in-patients with diabetes.

Absence of telomere shortening and oxidative DNA damage in the young adult offspring of women with pre-gestational type 1 diabetes.

AIMS/HYPOTHESIS: The offspring of mothers with pre-gestational type 1 diabetes (PGDM) may be at increased risk of glucose intolerance and cardiovascular disease in childhood. The underlying causes of these observations, and whether they persist into adulthood, are unknown. The aim of the present study was to test the hypothesis that fetal chromosomal telomere oxidative DNA damage resulting from maternal PGDM programmes the offspring towards a senescent phenotype that is detectable in young adulthood. METHODS: We studied 21 young adult offspring (age 16-23 years) with a maternal history of PGDM and 23 age- and weight-matched controls with no maternal history of diabetes. All participants underwent anthropometric assessments, a standard 75 g OGTT, measurement of peripheral blood mononuclear cell and skin fibroblast telomere length, fibroblast senescence, cell DNA damage (by determination of 8-oxoguanine levels using flow cytometry), plasma lipoprotein profiles (determined by nuclear magnetic resonance) and plasma levels of soluble adhesion molecules and inflammatory markers. RESULTS: The groups did not differ significantly with respect to anthropometric measures, glucose tolerance, fasting and 2 h plasma insulin levels during OGTT, estimated peripheral insulin resistance, peripheral blood mononuclear cell or fibroblast telomere length, DNA damage or senescence in vitro, plasma NMR lipoprotein profiles or levels of high-sensitivity C-reactive protein. Plasma concentrations of soluble intercellular adhesion molecule 1 (sICAM-1; p < 0.05) and IL-6 (p = 0.08) were higher in the PGDM offspring. CONCLUSIONS/INTERPRETATION: Young adult offspring of mothers with PGDM do not differ in terms of glucose tolerance, DNA damage or telomere length from controls of the same weight and BMI. This does not preclude such abnormalities at an earlier age, but there is no evidence of telomere damage as a pre-programming mechanism in the young adults enrolled in this study.

Three Tesla MRI for the diagnosis of meniscal and anterior cruciate ligament pathology: a comparison to arthroscopic findings.

AIM: To assess the accuracy of 3T magnetic resonance imaging (MRI) in the evaluation of meniscal and anterior cruciate ligament (ACL) injury. MATERIALS AND METHODS: Sixty-one consecutive patients were identified who were referred for evaluation of suspected intra-articular pathology with a 3T MRI and who, subsequently, underwent an arthroscopic procedure of the knee were included for the study. Two musculoskeletal radiologists interpreted the images. The sensitivity, specificity, positive predictive value, and negative predictive value were then calculated for the MRI versus the arthroscopic findings as a reference standard. RESULTS: The sensitivity and specificity for the overall detection of meniscal tears in this study was 84 and 93%, respectively. The results for the medial meniscus separately were 91 and 93% and for the lateral 77 and 93%. The evaluation of ACL integrity was 100% sensitive and specific. The meniscal tear type was correctly identified in 75% of cases and its location in 94%. CONCLUSION: This study demonstrates good results of 3T MRI in the evaluation of the injured knee. Caution should still be given to the interpretation on MRI of a lateral meniscus tear, and it is suggested that the standard diagnostic criteria of high signal reaching the articular surface on two consecutive image sections be adhered to even at these higher field strengths.

A national survey of in-patient diabetes services in the United Kingdom.

AIM: To examine in-patient diabetes services in all UK acute hospitals. METHODS: We asked the diabetes specialist team in all UK acute hospitals to complete a structured questionnaire on in-patient diabetes management guidelines, in-patient referral patterns, diabetes in-patient specialist nurse (DISN) services and diabetes bed occupancy in their hospital. RESULTS: Of the 262 UK acute hospitals, 239 (91.2%) provided data (2005-2006). UK teams reported high levels of clinical risk associated with in-patient diabetes care. One-third did not have diabetes management guidelines for day surgery, endoscopy, barium studies or immediate management of the diabetic foot. Patients admitted with diabetic ketoacidosis were not immediately referred to the specialist team in one-third of hospitals. About half had no routine access to podiatry or dietetic care for in-patients with diabetes. The majority of UK hospitals either never adopted Diabetes Mellitus, Insulin Glucose Infusion in Acute Myocardial Infarction (DIGAMI)-1 protocols or had recently changed practice, and half do not endorse the use of in-patient subcutaneous insulin 'sliding-scales'. One in five UK hospitals survey in-patient diabetes treatment satisfaction. DISN numbers have increased rapidly-126 hospitals (51.4%) had a DISN, most (69.1%) appointed since 2002. Most (80.2%) hospitals without a DISN used the out-patient specialist nurse team to provide in-patient care. CONCLUSIONS: This survey has identified substantial gaps in in-patient diabetes care in the UK. The rapid increase in DISN numbers indicates increasing attention to in-patient diabetes care in UK hospitals.

Trends in bed occupancy for inpatients with diabetes before and after the introduction of a diabetes inpatient specialist nurse service.

AIMS: To compare diabetes bed occupancy and inpatient length of stay, before and after the introduction of a dedicated diabetes inpatient specialist nurse (DISN) service in a large UK Hospital. METHODS: We analysed bed occupancy data for medical or surgical inpatients for 6 years (1998-2004 inclusive), with a DISN service in the final 2 years. Excess bed days per diabetes patient were derived from age band, specialty, and seasonally matched data for all inpatients without diabetes. We also analysed the number of inpatients with known diabetes who did not have diabetes recorded as a discharge diagnosis. RESULTS: There were 14,722 patients with diabetes (9.7% of all inpatients) who accounted for 101 564 occupied bed days (12.4% of total). Of these, 18 161 days (17.8%) were excess compared with matched patients without diabetes, and were concentrated in those < 75 years old. Mean excess bed days per diabetes inpatient under 60 years of age was estimated to be 1.9 days before the DISN appointment, and this was reduced to 1.2 bed days after the appointment (P = 0.03). This is equivalent to 700 bed days saved per year per 1000 inpatients with diabetes under 60 years old, with an identical saving for those aged 61-75 years (P = 0.008), a saving of 1330 diabetes bed days per year by one DISN. Excess diabetes bed occupancy was 167 excess bed days per year per 1000 patients with diabetes in the local population after the DISN appointment. One quarter of the known Type 2 diabetes population were admitted annually, but one quarter of patients had no diagnostic code for diabetes. CONCLUSIONS: Diabetes excess bed occupancy was concentrated in patients < 75 years old, and this was reduced notably following the introduction of a DISN service.

Chromosomal telomere attrition as a mechanism for the increased risk of epithelial cancers and senescent phenotypes in type 2 diabetes.

Telomeres are the repeat DNA sequences at the end of chromosomes necessary for successful DNA replication and chromosomal integrity. Telomeres shorten at cell division at a rate determined by oxidative DNA damage, and cells are triggered into replicative senescence once telomeres shorten to a critical length. Telomere-related chromosomal maintenance also has a role in carcinogenesis. Type 2 diabetes is characterised by increased oxidative stress, increased oxidative DNA damage, senescent retinal and renal phenotypes, and an increased risk of epithelial malignancy. We suggest that increased oxidative DNA damage and telomere attrition in type 2 diabetes leads to: (1) carcinogenic telomere-dependent chromosomal non-reciprocal translocations, genomic instability, and the development of epithelial cancers; (2) senescent retinal and renal phenotypes (expressed as diabetic retinopathy and nephropathy); and (3) senescent vascular endothelial, monocyte-macrophage and vascular smooth muscle cells (expressed as endothelial dysfunction and accelerated atherogenesis). An adverse intrauterine environment leads to increased feto-placental oxidative stress and feto-placental oxidative DNA damage. We also suggest that intrauterine oxidative DNA damage and telomere shortening is another point at which increased oxidative stress could contribute to a pre-programmed increased risk of senescent phenotypes in adult offspring, characterised by type 2 diabetes and epithelial malignancy. These suggestions can be used to understand early glucose intolerance in the young children of type 1 diabetes pregnancies, poor cancer outcomes in type 2 diabetes, beta cell fatigue in type 2 diabetes and the absence of increased epithelial cancer risk in type 1 diabetes.

The relationship between obsessive-compulsive symptoms and appraisals of emotional states.

A new measure assessing respondents' perceptions of the threat posed by their own emotions (the Perception of Threat from Emotion Questionnaire; the PTEQ) is presented. A range of data relating to the psychometric properties of the PTEQ indicates that it is a reliable measure of people's stable beliefs about their emotions, and is not highly correlated with either mood or measures of responsibility and thought-action fusion. In a student sample, regression analyses indicate that responses to the PTEQ significantly predict responses to a general measure of obsessionality (the Padua Inventory), even when levels of depression and anxiety are controlled for. Moreover, when compared with measures of responsibility and thought-action fusion, the PTEQ emerges as the strongest independent predictor of obsessionality. Of the seven different emotions to which the PTEQ relates, it is found that beliefs about 'anger' are the strongest predictor of obsessionality. Implications of these findings are discussed.

A mobile screening programme for the cardiovascular and microvascular complications of Type 2 diabetes in primary care.

The Diabetes National Service framework (NSF), and the quality payments in the new contract for UK General Practitioners, promote regular screening for diabetes complications. The new contract also includes immediate incentives to meet screening and quality targets, but it will be difficult to meet these targets in primary care. We have developed a mobile 'annual review' programme for patients with Type 2 diabetes managed solely in primary care, that screens for cardiovascular disease, hypertension, retinopathy and neuropathy at the patient's general practice, and gives written foot care, dietary advice and level 1 smoking cessation advice to all patients.

Examining the relationships between the Pro12Ala variant in PPARG and Type 2 diabetes-related traits in UK samples.

AIMS: The Pro12Ala polymorphism in the PPARG gene alters amino acid sequence and has shown consistent association with susceptibility to Type 2 diabetes in several populations. The present study makes use of large, well-characterized case-control resources to enhance understanding of this susceptibility effect by examining related traits, such as body mass index (BMI), waist-hip ratio and age at diagnosis. METHODS: The Pro12Ala variant was genotyped in two UK case samples, ascertained for positive family history and/or early onset of Type 2 diabetes (combined n=971); and in 1257 ethnically matched control subjects. RESULTS: There were significant associations of the Pro12Ala single nucleotide polymorphism (SNP) genotypes with diabetes in both case-control comparisons (P=0.025 and P=0.039). Comparing individuals homozygous for the Pro allele, with those carrying an Ala allele, the combined odds ratio for diabetes was 1.40 (95% CIs, 1.12-1.76, P=0.0031). There was no association between the variant and either waist-hip ratio or age at diagnosis. Proline homozygosity was associated with increased BMI in one patient group (P=0.013) and decreased BMI in the other (P=0.038). CONCLUSIONS: This study confirms that variation within PPARG influences susceptibility to Type 2 diabetes in UK samples. However, the relationship between PPARG variation and BMI is more complex, and studies in much larger sample sets will be required to more precisely characterize the effect of this variant on adiposity.

Elevated matrix metalloproteinase-2 and -3 production from human diabetic dermal fibroblasts.

BACKGROUND: Diabetic foot ulcers are characterized by elevated levels of matrix metalloproteinases (MMP), which could lead to excessive matrix breakdown and disruption to healing. It is unknown if this elevation is a function of wound healing, or if it is present within normal skin and a primary contributor to the increased risk of impaired healing. OBJECTIVES: To determine whether diabetic fibroblasts from unwounded skin show elevated MMP production compared with their nondiabetic counterparts. PATIENTS AND METHODS: Circular skin biopsies (4 mm diameter) were taken from the inside upper arm of four controls without diabetes and from four subjects with insulin-treated diabetes. Fibroblasts were incubated for a further 72 h and conditioned medium was collected and stored at -20 degrees C. The conditioned medium was assessed by gelatin zymography and Western blotting for MMP-2 and MMP-3. RESULTS: Diabetic dermal fibroblasts showed significantly elevated production of MMP-2 (P < 0.05) and pro-MMP-3 (P < 0.05) when compared with their nondiabetic counterparts. CONCLUSIONS: Dermal fibroblasts from normal unwounded skin are characterized by increased MMP production and this may be a primary contributing factor to the increased risk of nonhealing foot ulceration in diabetes.

Monocyte and neutrophil adhesion molecule expression during acute hyperglycemia and after antioxidant treatment in type 2 diabetes and control patients.

OBJECTIVE: We hypothesized that acute hyperglycemia (an independent cardiovascular risk factor) increases the expression of proatherogenic leukocyte adhesion molecule in type 2 diabetes and controls and that the expression of these adhesion molecules would be antioxidant sensitive. METHODS AND RESULTS: Twenty-three type 2 diabetes patients and 13 control patients underwent two oral glucose tolerance tests 14 days apart and took placebo or 800 IU daily of oral alpha tocopherol between tests. Monocyte and neutrophil expression of adhesion molecules Mac-1, LFA-1 and 3, ICAM-1, and VLA-4 were measured at 0, 120, and 240 minutes by using laser flow cytometry. Baseline adhesion molecule expression did not differ between groups, but there was a rapid, highly significant increase (P<0.0001) in the intensity of monocyte Mac-1 expression after a glucose load in both groups. Alpha-tocopherol supplementation reduced only Mac-1 expression in the diabetes group (P=0.03). CONCLUSIONS: Acute glycemic excursions of any degree cause highly significant, rapid increases in monocyte Mac-1 expression in type 2 diabetes patients and controls. Mac-1 mediates leukocyte vascular infiltration and is prothrombotic. These data suggest a mechanism for the link between glycemic excursions and increased vascular event rates.

An integrated mobile foot and retinal screening programme for people with Type 2 diabetes managed in primary care.

AIMS: To undertake a vascular and neurological assessment on the feet of all patients with Type 2 diabetes managed solely in local primary care. METHODS: A mobile screening podiatrist (working with an existing mobile retinal screening programme) screened a selected population of 4022 patients with Type 2 diabetes managed solely in 82 general practices. Doppler pressure assessments of peripheral vasculature, bioesthesiometer and monofilament assessment of peripheral neuropathy. RESULTS: This service was administratively simple to set up and integrated well with the retinal screening service and secondary care foot clinic, and was valued by the practices. Disease prevalences were 1.04% for foot ulceration, 19% for peripheral vascular disease and up to 29% for peripheral neuropathy. CONCLUSIONS: This programme screens all patients with known diabetes managed solely in primary care within a district and describes foot morbidity and allows risk stratification. This pattern of service could be a useful template for discussing the diabetes National Service Framework with primary care groups.

Impact of pregnancy on the progression of diabetic retinopathy in Type 1 diabetes.

AIMS: To evaluate the impact of pregnancy on the progression of diabetic retinopathy in women with Type 1 diabetes mellitus and to identify risk factors for the progression of retinopathy during pregnancy. METHODS: One hundred and seventy-nine pregnancies in 139 women with pregestational Type 1 diabetes were studied prospectively between January 1990 and December 1998. Dilated fundal examination was performed at booking, 24 weeks and 34 weeks or 4-6 weekly if retinopathy present at booking. Data were collected on glycaemic control (HbA(1c)) throughout pregnancy. RESULTS: Progression to proliferative retinopathy was seen in four (2.2%) pregnancies while moderate progression was seen in a further five (2.8%) pregnancies. Progression of retinopathy was significantly increased in women with duration of diabetes 10-19 years compared with duration < 10 years (10% vs. 0%; P = 0.007) and in women with moderate to severe background retinopathy at booking (30% vs. 3.7%; P = 0.01). Although HbA(1c) at booking was higher (7.5% vs. 6.6%; P = 0.08) and the fall in HbA(1c) between booking and 24 weeks was greater (1.6% vs. 1.2%; P = 0.2) in those women showing progression of retinopathy, these changes were not significant. CONCLUSIONS: Progression of retinopathy in pregnancy was uncommon (5.0% pregnancies) but was significantly more common in women with duration of diabetes > 10 years and in women with moderate to severe retinopathy at baseline. Laser therapy was needed in 2.2% pregnancies, which is much lower than that reported in earlier studies. Diabet. Med. 18, 573-577 (2001)

Immotile sperm and infertility in mice lacking mitochondrial voltage-dependent anion channel type 3.

Voltage-dependent anion channels (VDACs), also known as mitochondrial porins, are small channel proteins involved in the translocation of metabolites across the mitochondrial outer membrane. A single channel-forming protein is found in yeast, whereas higher eukaryotes express multiple VDACs, with humans and mice each harboring three distinct channels (VDAC1-3) encoded by separate genes. To begin to assess the functions of each of the three isoforms, the VDAC3 gene was inactivated by targeted disruption in embryonic stem cells. Here we show that mice lacking VDAC3 are healthy, but males are infertile. Although there are normal sperm numbers, the sperm exhibit markedly reduced motility. Structural defects were found in two-thirds of epididymal axonemes, with the most common abnormality being loss of a single microtubule doublet at a conserved position within the axoneme. In testicular sperm, the defect was only rarely observed, suggesting that instability of a normally formed axoneme occurs with sperm maturation. In contrast, tracheal epithelial cilia showed no structural abnormalities. In addition, skeletal muscle mitochondria were abnormally shaped, and activities of the respiratory chain complexes were reduced. These results demonstrate that axonemal defects may be caused by associated nonaxonemal components such as mitochondrial channels and illustrate that normal mitochondrial function is required for stability of the axoneme.

Increased DNA oxidative susceptibility without increased plasma LDL oxidizability in Type II diabetes: effects of alpha-tocopherol supplementation.

In vivo supplementation studies of the antioxidant alpha-tocopherol in human Type II diabetes have used surrogate, rather than direct, markers of oxidative damage/antioxidant protection and have used higher doses of alpha-tocopherol than used in coronary secondary prevention trials. We tested the hypothesis that oral alpha-tocopherol in a dosage regimen used in secondary prevention trials would reduce directly observed oxidatively induced single-strand breaks in lymphocyte DNA in Type II diabetes. We studied 40 people with Type II diabetes and 30 controls in a randomized, double-blind, placebo-controlled trial of 400 i.u. of oral alpha-tocopherol daily for 8 weeks. Lymphocyte DNA single-strand breaks and low-density lipoprotein (LDL) particle size and oxidizability were measured at baseline, after 8 weeks, and after 4 weeks washout. Polymorphisms in the gene for the antioxidant enzyme paraoxonase-1 gene (position 192) were measured. The diabetics had increased DNA oxidative susceptibility (P=0.008), without increased LDL oxidative susceptibility. There was a direct relationship between DNA oxidative susceptibility and baseline plasma alpha-tocopherol in the diabetes group alone (r=0.421, r(2)=0.177 and P=0.023), but DNA and LDL oxidative susceptibility were not influenced by alpha-tocopherol supplementation in either group in this regimen. Paraoxonase-1 gene polymorphisms did not contribute to LDL or DNA oxidative susceptibility or response to alpha-tocopherol. Increased DNA oxidative susceptibility, therefore, can occur in Type II diabetes without increased LDL oxidative susceptibility, but alpha-tocopherol supplementation in this regimen has no influence on DNA or LDL oxidative susceptibility in Type II diabetes or controls. Polymorphisms in the paraoxonase gene (position 192) are not associated with differences in oxidative susceptibility or responses to alpha-tocopherol.

n-3 polyunsaturated fatty acid supplementation, monocyte adhesion molecule expression and pro-inflammatory mediators in Type 2 diabetes mellitus.

AIMS: To examine the effect of n-3 polyunsaturated fatty acid supplements on the monocyte surface expression of adhesion molecules involved in proatherogenic monocyte-endothelial interactions, and on pro-inflammatory mediators in Type 2 diabetes mellitus. METHODS: Twenty-nine subjects with Type 2 diabetes and 21 controls without diabetes were studied. Monocyte expression of leucocyte function-associated antigens 1 and 3, intercellular adhesion molecule-1, and the major histocompatibility complex class II molecule HLA-DR were measured using a laser flow cytometric method. Supplementation with 2.08 g n-3 fatty acids for 21 days was undertaken and measurements repeated. Plasma soluble adhesion molecule concentrations, plasminogen activator inhibitor-1 activity and antigen and pro-inflammatory mediators (cysteinyl leukotriene and monocyte leukotriene B4) were also measured. RESULTS: Groups did not differ in monocyte expression of adhesion molecules or HLA-DR, or in leukotriene production although plasma soluble adhesion molecule concentrations were higher in the diabetes groups (P<0.05). n-3 fatty acid supplementation influenced neither the expression of these molecules nor plasma soluble adhesion molecule concentrations or leukotriene production. CONCLUSIONS: This study does not support increased monocyte adhesion molecule expression or abnormal monocyte production of pro-inflammatory mediators as mechanisms for increased atherogenic risk in Type 2 diabetes. Cardioprotective actions of n-3 fatty acids may not be mediated through these mechanisms.