Impacts of metal mining on river systems: a global assessment

An estimated 23 million people live on floodplains affected by potentially dangerous concentrations of toxic waste derived from past and present metal mining activity. We analyzed the global dimensions of this hazard, particularly in regard to lead, zinc, copper, and arsenic, using a georeferenced global database detailing all known metal mining sites and intact and failed tailings storage facilities. We then used process-based and empirically tested modeling to produce a global assessment of metal mining contamination in river systems and the numbers of human populations and livestock exposed. Worldwide, metal mines affect 479,200 kilometers of river channels and 164,000 square kilometers of floodplains. The number of people exposed to contamination sourced from long-term discharge of mining waste into rivers is almost 50 times greater than the number directly affected by tailings dam failures.

Serum and plasma amino acids as markers of prediabetes, insulin resistance, and incident diabetes

Presently, routine screening misses many cases of prediabetes and early type 2 diabetes (T2D). Therefore, better biomarkers are needed for a simple and early detection of abnormalities of glucose metabolism and prediction of future T2D. Possible candidates for this include plasma or serum amino acids because glucose and amino acid metabolism are closely connected. This review presents the available evidence of this connectivity and discusses its clinical implications. First, we examine the underlying physiological, pre-analytical, and analytical issues. Then, we summarize results of human studies that evaluate amino acid levels as markers for insulin resistance, prediabetes, and future incident T2D. Finally, we illustrate the interconnection of amino acid levels and metabolic syndrome with our own data from a deeply phenotyped human cohort. We also discuss how amino acids may contribute to the pathophysiology of T2D. We conclude that elevated branched-chain amino acids and reduced glycine are currently the most robust and consistent amino acid markers for prediabetes, insulin resistance, and future T2D. Yet, we are cautious regarding the clinical potential even of these parameters because their discriminatory power is insufficient and their levels depend not only on glycemia, but also on other components of the metabolic syndrome. The identification of more precise intermediates of amino acid metabolism or combinations with other biomarkers will, therefore, be necessary to obtain in order to develop laboratory tests that can improve T2D screening.

Insulin secretory defect in familial partial lipodystrophy Type 2 and successful long-term treatment with a glucagon-like peptide 1 receptor agonist

BACKGROUND

Familial partial lipodystrophies are rare monogenic disorders that are often associated with diabetes. In such cases, it can be difficult to achieve glycaemic control.

CASE REPORT

We report a 34-year old woman with familial partial lipodystrophy type 2 (Dunnigan) and diabetes; her hyperglycaemia persisted despite metformin treatment. A combined intravenous glucose tolerance-euglycaemic clamp test showed severe insulin resistance, as expected, but also showed strongly diminished first-phase insulin secretion. After the latter finding, we added the glucagon-like peptide-1 receptor agonist liraglutide to the patient's treatment regimen, which rapidly normalized plasma glucose levels. HbA_1c values <42 mmol/mol (6.0%) have now been maintained for over 4 years.

CONCLUSION

This case suggests that a glucagon-like peptide-1 receptor agonist may be a useful component of glucose-lowering therapy in individuals with familial partial lipodystrophy and diabetes mellitus.

Physical fitness and plasma leptin in women with recent gestational diabetes

Aims/Hypothesis

Low physical fitness (PF) is a risk factor for type 2 diabetes mellitus (T2D). Women with a history of gestational diabetes (GDM) are at risk for T2D at a young age, but the role of PF in this population is not clear. PF has also been found to correlate inversely with plasma leptin in previous studies. Here, we examine whether women who had GDM have lower PF than women after a normoglycemic pregnancy and, second, whether PF is associated with plasma leptin, independently of body fat mass.

Methods

Cross-sectional analysis of 236 participants in the PPSDiab Study (cohort study of women 3–16 months after delivery, 152 after gestational diabetes (pGDM), 84 after normoglycemic pregnancy (control subjects); consecutively recruited 2011–16); medical history, physical examination with bioelectrical impedance analysis (BIA), whole body magnetic resonance imaging (MRI) (n = 154), 5-point oral glucose tolerance test, cardiopulmonary exercise testing, clinical chemistry including fasting plasma leptin; statistical analysis with Mann–Whitney U and t -test, Spearman correlation coefficient, multiple linear regression.

Results

Women pGDM had lower maximally achieved oxygen uptake (VO_2peak/kg: 25.7(21.3–29.9) vs. 30.0(26.6–34.1)ml/min/kg; total VO_2peak: 1733(1552–2005) vs. 1970(1767–2238)ml/min; p<0.0001 for both), and maximum workload (122.5(105.5–136.5) vs. 141.0(128.5–159.5)W; p<0.0001). Fasting plasma leptin correlated inversely with PF (VO_2peak/kg ρ = -0.72 p<0.0001; VO_2peak ρ = -0.16 p = 0.015; max. load ρ = -0.35 p<0.0001). These associations remained significant with adjustment for body mass index, or for body fat mass (BIA and MRI).

Conclusions/Interpretation

Women with a recent history of GDM were less fit than control subjects. Low PF may therefore contribute to the risk for T2D after GDM. This should be tested in intervention studies. Low PF also associated with increased leptin levels–independently of body fat. PF may therefore influence leptin levels and signaling. This hypothesis requires further investigation.

[Current concepts in diagnostics and therapy of diabetes mellitus]

In Germany approximately 7.2% of the population currently suffer from diabetes mellitus. A further increase in the prevalence is expected in the coming years. Many therapy options, sometimes even without a risk of hypoglycemia, are now available. The foundations of a sufficient therapy of type 2 diabetes are, however, still lifestyle measures, such as weight reduction, optimized nutrition and increased physical activity. Optimization of cardiac and cerebrovascular risk factors is also an essential component of management of diabetes in order to reduce or even avoid secondary complications.

[Optimising pain therapy for neurological inpatients]

BACKGROUND

The Department of Neurology at the Medical University Graz has implemented a multiprofessional pain management concept and evaluated the outcome by means of a patient survey.

METHODS

Standard operating procedures for standardised pain measurement, documentation and therapy were developed. All engaged professional participants were trained before implementation.

RESULTS

88.7 % of the surveyed 63 patients reported pain during the hospitalisation. During the night and in the morning, the occurrence of severe pain was most likely. The position or activity most likely triggering severe pain was mobilisation (19 %). Patients with degenerative diseases of the spine without radiculopathy reported the highest levels of pain.

CONCLUSIONS

Pain is an important problem for neurological inpatients. Nocturnal pain, pain induced by mobilisation, and pain therapy for patients with degenerative diseases of the spine without radiculopathy require particular attention.

[Update on type 1 diabetes]

Type 1a diabetes develops from a chronic autoimmune process leading to absolute insulin deficiency and proneness to ketosis. Prospective studies have clearly shown that intensive insulin therapy (ICT) results in improved quality of life and reduced development of diabetes-associated microvascular and macrovascular complications. The gold standard of therapy in type 1 diabetes is insulin injection with a basal bolus insulin regimen, in which patient daily routine and wishes are considered. The treatment goals should be determined on an individualized basis together with the patient. An HbA(1c) value < 7.0% is considered to be well controlled while values ≤ 6.5% indicate an excellent blood glucose control, as long as there are no episodes of severe hypoglycemia. As many adult patients with type 1 diabetes develop additional cardiovascular risk factors dyslipidemia and hypertension should also be considered and treated according to current treatment guidelines. A multimodal treatment may be the best way to preserve quality of life in patients with type 1 diabetes.

Reduced urinary glutamate levels are associated with the frequency of migraine attacks in females

BACKGROUND AND PURPOSE

Recent evidences indicate that glutamatergic homeostasis disorders are implicated in the pathogenesis of migraine. In particular, plasma and cerebrospinal fluid glutamate levels seem to be altered in migraine patients. However, the impacts of glutamate on migraine and especially on aura symptoms, alterations in the frequency of migraine attacks as well as investigations on glutamate on migraine-related metabolic dysfunctions, like hyperinsulinaemia, and an atherogenic lipid profile remain elusive to date. The aim of the present study was to investigate the impact of glutamate on migraine and related metabolic dysfunctions.

METHODS

We investigated the urinary glutamate levels of female migraineurs (n = 48) in the interictal phase and healthy controls (n = 48). Parameters of the insulin- and lipid metabolism, inflammatory parameters and anthropometric parameters were additionally determined.

RESULTS

Urinary glutamate levels of female migraineurs were significantly decreased with respect to the control group. Logistic regression revealed an odds ratio of 4.04 for migraine. We found a significant correlation with the time-period of patients' last attack and a significant inverse correlation with the annual frequency of migraine attacks. Other parameters of the insulin- and lipid metabolism, anthropometric and inflammatory parameters showed no significant correlation with glutamate levels.

CONCLUSION

We show here that female migraineurs exhibit decreased urinary glutamate levels which are associated with a 4.04-fold higher risk for migraine and correlated with patients' frequency of migraine attacks.

Reduced proliferation and a high apoptotic frequency of pancreatic beta cells contribute to genetically-determined diabetes susceptibility of db/db BKS mice

Leptin receptor-deficient db/db mice are a commonly used research model and it is known that the genetic background, on which the mutation is bred, modulates the phenotype. While diabetes-resistant strains sustain near normal glycemia and hyperinsulinemia, susceptible backgrounds develop overt hyperglycemia and islet involution. We hypothesized that genetically-determined differences in the proliferative capacity and the apoptotic frequency of pancreatic beta cells contribute to this phenotypic disparity. We studied C57BLKS/J (BKS; diabetes-susceptible) and C57BL/6 (B6; diabetes-resistant) db/db mice and heterozygous controls from 5 to 12 weeks of age. Body weight, fasting blood glucose, plasma insulin, HOMA-IR, alpha cell mass, beta cell mass, proliferation and apoptosis were measured. Comparable insulin resistance developed in the 2 db/db strains, which was well compensated for on both genetic backgrounds until 7 weeks of age. As expected, the BKS mice became hyperglycemic at 9 weeks. Beta cell proliferation was initially increased in both db/db strains but decreased rapidly in the BKS mice with advancing age. The rate of beta cell apoptosis was already higher in prediabetic BKS mice than in their B6 counterparts. Beta cell mass increased continuously in the B6 strain until 12 weeks of age, but declined from 7 weeks onwards in BKS. An age-dependent decline of beta cell proliferation and an increased rate of beta cell apoptosis already in the prediabetic state probably contribute to the diabetes susceptibility of db/db BKS mice. These factors could also play a role in the genetic predisposition for type 2 diabetes in humans.

Oxidative stress is associated with migraine and migraine-related metabolic risk in females

BACKGROUND AND PURPOSE

Oxidative stress is discussed to be implicated in the pathophysiology of migraine. However, data are in part controversial and the possible underlying mechanisms remain elusive to date. The aim of this study was to investigate the oxidative stress status of female patients with migraine and its implications on migraine-related metabolic alterations.

METHODS

Oxidative stress markers malondialdehyde (MDA), 4-hydroxy-2-nonenal (HNE), carbonylated proteins, parameters of associated nitric oxide stress, inflammation, lipid- and glucose-metabolism were determined in the interictal phase in female patients with migraine and controls.

RESULTS

We found significantly increased HNE levels in female migraineurs compared with controls. Logistic regression analyses of HNE revealed an odds ratio for migraine of 4.55. HNE showed significant correlations with the nitric oxide pathway, the insulin- and the lipid-metabolism.

CONCLUSIONS

We show here that increased oxidative stress is associated with migraine and contributes to migraine-related metabolic risk like nitrosative stress, an atherogenic lipid profile and hyperinsulinemia. Our data suggest that oxidative stress may represent a key event in the pathophysiology of migraine and a suitable therapeutic target.

Increased matrix metalloproteinase activity is associated with migraine and migraine-related metabolic dysfunctions

OBJECTIVE

Matrix metalloproteinases (MMPs) and their inhibitors (TIMPs) are discussed to be involved in the pathophysiology of migraine. Moreover, MMPs may also be involved in migraine-related metabolic alterations like an atherogenic lipid profile and hyperinsulinemia. The aim of this study was to investigate the impact of MMPs and TIMPs on migraine with and without aura and related metabolic dysfunctions.

METHODS

MMP activity, six MMPs and three TIMPs, parameters of the insulin and lipid metabolism as well as anthropometric parameters were determined in 124 non-obese subjects.

RESULTS

We found highly significant increased MMP activity in migraine patients independent of aura symptoms, which was associated with migraine with an odds ratio of 7.57. Interestingly, none of the determined MMPs and TIMPs showed significant different serum levels between migraine patients and healthy controls. We found significant correlations between MMP activity and parameters of the insulin and lipid metabolism, like Homeostasis Model Assessment index (HOMA index), cholesterol, triglycerides, and oxidized LDL.

CONCLUSION

We show here that increased MMP activity is tightly associated with migraine and migraine-related hyperinsulinemia and atherogenic lipid alterations. Our findings represent a new pathophysiological mechanism, which may be of clinical relevance, especially in regard to therapeutic approaches using MMP inhibitors.

Hyperinsulinaemia in migraineurs is associated with nitric oxide stress

There is growing evidence that alterations in the insulin and glucose metabolism may be involved in the pathogenesis of migraine. Nitric oxide (NO) stress has been associated with migraine. However, the role of NO on the insulin and glucose metabolism in migraineurs has remained elusive to date. The aim of the present study was to investigate the insulin and glucose metabolism in migraineurs and to determine possible interactions with the NO pathway. One hundred and twenty non-obese probands participated in this study, including 48 migraineurs and 72 healthy volunteers. Various parameters of the NO pathway, glucose metabolism as well as body measurement parameters were determined. We found a highly significantly increased insulin and Homeostasis Model Assessment (HOMA)-index in migraine patients, whereas fasting glucose was decreased. Logistic regression revealed an odds ratio of 5.67 for migraine, when comparing the lowest with the highest quartile of HOMA. Multivariate analysis showed that HOMA, waist-to-length ratio and nitrite as parameters of NO stress were highly significantly correlated. We show here that hyperinsulinaemia is associated with migraine and, furthermore, is correlated with increased NO stress. These findings represent a new pathophysiological mechanism that may be of clinical relevance.

[Consensus statement "Dementia 2010" of the Austrian Alzheimer Society]

The Austrian Alzheimer Society developed evidence-based guidelines based on a systematic literature search and criteria-guided assessment with subsequent transparent determination of grades of clinical recommendation. The authors evaluated currently available therapeutic approaches for the most common forms of dementia and focused on diagnosis and pharmacological intervention, taking into consideration the situation in Austria. The purpose of these guidelines is the rational and cost-effective use of diagnostic and therapeutic measures in dementing illnesses. Users are physicians and all other providers of care for patients with dementia in Austria.

Increased nitric oxide stress is associated with migraine

Nitric oxide (NO) has been implicated in migraine attacks, but the role of NO in migraine remains unclear. We here hypothesize that increased NO in the headache-free period is associated with migraine. One hundred and thirty probands participated in this study. Various parameters of the NO pathway, such as nitrate, nitrite, arginine, citrulline, nitrosylated proteins, asymmetric dimethylarginine, symmetrical dimethylarginine, expression of endothelial nitric oxide synthase (eNOS) and inducible nitric oxide synthase and two polymorphisms of eNOS were investigated. We found significant increased nitrate and decreased nitrite levels in migraineurs in the headache-free period. Nitrate and nitrite levels showed a significant inverse correlation. Logistic regression revealed an odds ratio of 3.6 for migraine. Other parameters of the NO pathway were neither altered in migraineurs nor correlated with nitrate. We show here that migraine patients suffer under sustained increased nitrosative stress in the headache-free period, which is associated with a 3.6-fold higher risk for migraine.

Affinity maturation by targeted diversification of the CDR-H2 loop of a monoclonal Fab derived from a synthetic naïve human antibody library and directed against the internal trimeric coiled-coil of gp41 yields a set of Fabs with improved HIV-1 neutralization potency and breadth

Previously we reported a broadly HIV-1 neutralizing mini-antibody (Fab 3674) of modest potency that was derived from a human non-immune phage library by panning against the chimeric gp41-derived construct N(CCG)-gp41. This construct presents the N-heptad repeat of the gp41 ectodomain as a stable, helical, disulfide-linked trimer that extends in helical phase from the six-helix bundle of gp41. In this paper, Fab 3674 was subjected to affinity maturation against the N(CCG)-gp41 antigen by targeted diversification of the CDR-H2 loop to generate a panel of Fabs with diverse neutralization activity. Three affinity-matured Fabs selected for further study, Fabs 8060, 8066 and 8068, showed significant increases in both potency and breadth of neutralization against HIV-1 pseudotyped with envelopes of primary isolates from the standard subtype B and C HIV-1 reference panels. The parental Fab 3674 is 10-20-fold less potent in monovalent than bivalent format over the entire B and C panels of HIV-1 pseudotypes. Of note is that the improved neutralization activity of the affinity-matured Fabs relative to the parental Fab 3674 was, on average, significantly greater for the Fabs in monovalent than bivalent format. This suggests that the increased avidity of the Fabs for the target antigen in bivalent format can be partially offset by kinetic and/or steric advantages afforded by the smaller monovalent Fabs. Indeed, the best affinity-matured Fab (8066) in monovalent format ( approximately 50 kDa) was comparable in HIV-1 neutralization potency to the parental Fab 3674 in bivalent format ( approximately 120 kDa) across the subtype B and C reference panels.

Betacellulin overexpression in transgenic mice improves glucose tolerance and enhances insulin secretion by isolated islets in vitro

Betacellulin (BTC), a ligand of the epidermal growth factor receptor, has been shown to promote growth and differentiation of pancreatic beta-cells and to improve glucose metabolism in experimental diabetic rodent models. We employed transgenic mice (BTC-tg) to investigate the effects of long-term BTC overabundance on islet structure and glucose metabolism. Expression of BTC is increased in transgenic islets, which show normal structure and distribution of the different endocrine cell types, without pathological alterations. BTC-tg mice exhibit lower fasted glucose levels and improved glucose tolerance associated with increased glucose-induced insulin secretion. Surprisingly, quantitative stereological analyses revealed that, in spite of increased cell proliferation, the islet and beta-cell volumes were unchanged in BTC-tg mice, suggesting enhanced cell turnover. Insulin secretion in vitro was significantly higher in transgenic islets in medium containing high glucose (11.2 or 16.7mM) as compared to control islets. Our results demonstrate that long-term BTC overabundance does not alter pancreatic islet structure and beta-cell mass, but enhances glucose-induced insulin secretion in vivo as well as in vitro.

Targeted radionuclide therapy: theoretical study of the relationship between tumour control probability and tumour radius for a 32P/33P radionuclide cocktail

As revealed by previous theoretical studies, targeted radionuclide therapy (TRT) that relies on a single beta-emitting radioisotope is likely to be inappropriate for clinical scenarios such as disseminated malignancy. For a patient with a vast number of tumours and metastases of largely differing sizes a high level of therapeutical efficiency might be achieved only for a restricted range of tumour sizes. This is due to the limited range of beta-electrons in human tissue, essentially causing the therapeutical impact to vary tremendously with tumour size. The dependence of curability on the tumour dimension is expected to be significantly altered if a radionuclide cocktail, consisting of a long-range and a short-range beta-emitter, such as (32)P and (33)P, is involved in the treatment. In this study, a radiation transport simulation was performed, using the MCNP4c2 Monte Carlo code, in order to investigate the relationship between tumour control probability (TCP) and tumour size, associated with concurrent use of (32)P and (33)P. Two different models of intratumoural distribution of cumulated activity were taken into account. One simulated an ideal radionuclide uptake in tumour tissue and the other referred to a limited radiotracer penetration. The results were examined in comparison to tumours targeted with pure (32)P, (33)P and (131)I. For both uptake scenarios a considerable reduction of the overall variation of TCP and thus an increasing chance of achieving tumour cure was observed for tumour sizes ranging from microscopic dimensions up to macroscopic diameters, if the targeted radionuclide treatment relies on a (32)P/(33)P cocktail. It was revealed that particular attention has to be given to the ratio of the (32)P and (33)P specific cumulated activities (SCA) in the tumour, since this is a significant determinant of the resulting behaviour of tumour control probability as the tumour diameter varies. This study suggests that a 32P/33P approach is more applicable to diseases that involve a variety of tumours and metastases differing in size.