Cadmium determination in natural water samples with an automatic multisyringe flow injection system coupled to a flow-through screen printed electrode.

Heavy metals, as cadmium, attract a rising attention in environmental studies due to their increasing release by human activities and acute toxicity. In situ analytical methods are needed to minimize current uncertainties caused by the transport and conservation of samples. Here, we present the completely automatic determination of Cd in natural waters using a newly developed screen printed electrode sensor (SPE), inserted in a homemade purpose-built flow cell coupled to a Multi-Syringe Flow Injection Analysis system (MSFIA). The working electrode of SPEs was constituted by a carbon film modified with Nafion. Cd was plated on an in situ bismuth film and determined using Square Wave Anodic Stripping Voltammetry. Different chemical conditions of deposition and stripping were studied. A sample/acetic buffer mixture was found to be a well suited medium to form the Bi film and perform the analysis. Cd was quantified via calibration by on line standard additions. The limit of detection was found to be 0.79µgL(-1), well below the limit stipulated by the European directive (5µgL(-1)). Good sample throughput (14h(-1)) and low consumption of reagent and sample (1.3mL) were also obtained in line with previous works in Cd flow analysis.

Dutogliptin, a selective DPP4 inhibitor, improves glycaemic control in patients with type 2 diabetes: a 12-week, double-blind, randomized, placebo-controlled, multicentre trial.

AIM: To determine efficacy and tolerability of dutogliptin, a dipeptidyl peptidase 4 (DPP4) inhibitor, in patients with type 2 diabetes mellitus. METHODS: This was a 12-week, multicentre, randomized, double-blind, placebo-controlled trial in 423 patients with type 2 diabetes with suboptimal metabolic control. Following a 2-week single-blind placebo run-in, patients aged 18-75 years with a body mass index of 25-48 kg/m(2) and baseline HbA1c of 7.3-11.0% were randomized 2:2:1 to receive once-daily oral therapy with either dutogliptin (400 or 200 mg) or placebo on a background medication of either metformin alone, a thiazolidinedione (TZD) alone or a combination of metformin plus a TZD. RESULTS: Average HbA1c at baseline was 8.4%. Administration of dutogliptin 400 and 200 mg for 12 weeks decreased HbA1c by -0.52% (p < 0.001) and -0.35% (p = 0.006), respectively (placebo-corrected values), with absolute changes in HbA1c for the 400 mg, 200 mg and placebo groups of -0.82, -0.64 and -0.3%, respectively. The proportion of patients achieving an HbA1c < 7% was 27, 21 and 12% at dutogliptin doses of 400 and 200 mg or placebo, respectively (p = 0.008 for comparison of 400 mg vs. placebo). Fasting plasma glucose (FPG) levels were significantly reduced in both active treatment groups compared to placebo: the placebo-corrected difference was -1.00 mmol/l (p < 0.001) for the 400 mg group and -0.88 mmol/l (p = 0.003) for the 200 mg group. Dutogliptin caused significantly greater reductions in postprandial glucose AUC (0-2h) in both the 400 and 200 mg groups (placebo corrected values -2.58 mmol/l/h, p < 0.001 and -1.63 mmol/l/h, p = 0.032, respectively). In general, patients tolerated the study drug well. There were minor, not clinically meaningful differences in adverse events (AEs) between dutogliptin-treated patients and placebo controls, and 60% of all reported AEs were mild. Vital signs and body weight were stable, and routine safety laboratory parameters did not change compared with placebo. Trough ex vivo DPP4 inhibition at the end of the 12-week treatment period was 80 and 70%, at the 400 and 200 mg doses of dutogliptin, respectively. CONCLUSIONS: Dutogliptin treatment for 12 weeks improved glycaemic control in patients with type 2 diabetes who were on a background medication of metformin, a TZD or metformin plus a TZD. Tolerability was favourable for both doses tested. The 400 mg dose of dutogliptin resulted in larger changes of HbA1c and FPG and more subjects reached an HbA1c target of < 7% than the 200 mg dose.

Diversity, ecology and herbivory of hairstreak butterflies (Theclinae) associated with the velvet tree, Miconia calvescens in Costa Rica.

Larvae of three species of hairstreak butterflies in the subfamily Theclinae (Lepidoptera: Lycaenidae) were found feeding on developing inflorescences, flower buds, and immature fruits of the velvet tree, Miconia calvescens DC. (Myrtales: Melastomataceae) in Costa Rica. Erora opisena (Druce), Parrhasius polibetes (Cramer), and Temecla paron (Godman and Salvin) were studied in association with M. calvescens, an uncommon tree in its natural range in the neotropics and a target for biocontrol as an invader in Pacific islands. Host plant use by the three theclines was similar, with eggs being laid on inflorescences and cryptic larvae remaining there throughout development. Feeding damage by E. opisena was most abundant in pre-flowering M. calvescens, when 23% of inflorescences showed feeding damage characteristic of this species. Feeding damage by T. paron peaked at flowering, when 30% of inflorescences were affected. At field sites, E. opisena and T. paron damaged an average of 26 and 18% of each attacked inflorescence, respectively. In cage experiments, individual third- and fourth-instar larvae of E. opisena damaged an average of 24 and 21% of an inflorescence before pupating, respectively. This study provides the first host plant record for E. opisena and T. paron, the first record of P. polibetes feeding on Melastomataceae, and the first records of E. opisena and T. paron presence in Costa Rica.

Early-onset type 2 diabetes: metabolic and genetic characterization in the mexican population.

The objective of this study was to investigate possible defects in the insulin sensitivity and/or the acute insulin response in a group of Mexican patients displaying early-onset type 2 diabetes and to evaluate the contribution of mutations in three of the genes linked to maturity-onset diabetes of the young. We studied 40 Mexican patients with an age of diagnosis between 20 and 40 yr in which the insulin sensitivity as well as the insulin secretory response were measured using the minimal model approach. A partial screening for possible mutations in 3 of the 5 genes linked to maturity-onset diabetes of the young was carried out by PCR-single strand conformation polymorphism analysis. A low insulin secretory capacity (AIRg = 68.5 +/- 5 muU/mL.min) and a near-normal insulin sensitivity (3.43 +/- 0.2 min/muU.mL x 10(4)) were found in these patients. Among this group we found two individuals carrying missense mutations in exon 4 of the hepatocyte nuclear factor-1alpha (HNF-4alpha) gene (Asp(126)-->His/Tyr and Arg(154)-->Gln, respectively) and one carrying a nonsense mutation in exon 7 of the HNF-1alpha gene (Gln(486)-->stop codon); 7.5% had positive titers for glutamic acid decarboxylase antibodies. Thirty-five percent of cases had insulin resistance; these subjects had the lipid abnormalities seen in the metabolic syndrome. A defect in insulin secretion is the hallmark in Mexican diabetic patients diagnosed between 20 and 40 yr of age. Mutations in either the HNF-1alpha or the HNF-4alpha genes are present among the individuals who develop early-onset diabetes in our population. These particular sequence changes have not been previously reported and therefore represent putative new mutations. Even in the absence of endogenous hyperinsulinemia, insulin resistance is associated with an adverse lipid profile.

[Comparison of HOMA IR with the minimal model for measuring insulin sensitivity in polycystic ovary syndrome]. / Comparación del HOMA IR con el modelo mínimo para medir sensibilidad a la insulina en el síndrome de ovarios poliquísticos.

BACKGROUND: Polycystic ovary syndrome (PCOS) is the most common endocrine disorder of premenopausal women. These women have insulin resistance independent of obesity; and insulin resistance is now recognized as a risk factor for the development of type 2 diabetes mellitus, hypertension and cardiovascular disease. PURPOSE: We sought, therefore, to assess whether there was correlation between a simple fasting measure of insulin sensitivity (Homeostatic Model) and the Minimal-Model in this syndrome. METHODS: Thirty-three PCOS women (aged 22.7 +/- 6.2 years and body mass index (BMI) 29.1 +/- 5.4) underwent frequently sampled i.v. glucose tolerance test (Minimal-Model). RESULTS: Seventeen patients (51.5%) had insulin sensitivity < 1.5 x 10(-4) min.-1.microU-1.mL-1. Patients with BMI > de 27 was more resistant than the BMI < or = de 27 (p = 0.004). The correlation in PCOS between Si (insulin sensitivity) and HOMA IR was found significant for all the group (p = 0.0001; RRANK = -0.76) and those women with BMI > de 27 (RRANK = -0.77; p = 0.00006), but not significant correlation was found in those with BMI < or = de 27 (RRANK = -0.43; p = 0.13). CONCLUSIONS: We conclude that the HOMA IR may be useful as a screening test for insulin resistance in overweight and obese Mexican PCOS women but not in the lean ones.