Concerted action of ENaC, Nedd4-2, and Sgk1 in transepithelial Na(+) transport.

The epithelial Na(+) channel (ENaC), located in the apical membrane of renal aldosterone-responsive epithelia, plays an essential role in controlling the Na(+) balance of extracellular fluids and hence blood pressure. As of now, ENaC is the only Na(+) transport protein for which genetic evidence exists for its involvement in the genesis of both hypertension (Liddle's syndrome) and hypotension (pseudohypoaldosteronism type 1). The regulation of ENaC involves a variety of hormonal signals (aldosterone, vasopressin, insulin), but the molecular mechanisms behind this regulation are mostly unknown. Two regulatory proteins have gained interest in recent years: the ubiquitin-protein ligase neural precursor cell-expressed, developmentally downregulated gene 4 isoform Nedd4-2, which negatively controls ENaC cell surface expression, and serum glucocorticoid-inducible kinase 1 (Sgk1), which is an aldosterone- and insulin-dependent, positive regulator of ENaC density at the plasma membrane. Here, we summarize present ideas about Sgk1 and Nedd4-2 and the lines of experimental evidence, suggesting that they act sequentially in the regulatory pathways governed by aldosterone and insulin and regulate ENaC number at the plasma membrane.

Efficacy, safety and pharmacokinetic of once-daily boosted saquinavir (1500/100 mg) together with 2 nucleos(t)ide reverse transcriptase inhibitors in real life: a multicentre prospective study.

BACKGROUND. Ritonavir-boosted saquinavir (SQVr) is nowadays regarded as an alternative antiretroviral drug probably due to several drawbacks, such as its high pill burden, twice daily dosing and the requirement of 200 mg ritonavir when given at the current standard 1000/100 mg bid dosing. Several once-daily SQVr dosing schemes have been studied with the 200 mg SQV old formulations, trying to overcome some of these disadvantages. SQV 500 mg strength tablets became available at the end of 2005, thus facilitating a once-daily regimen with fewer pills, although there is very limited experience with this formulation yet. METHODS. Prospective, multicentre study in which efficacy, safety and pharmacokinetics of a regimen of once-daily SQVr 1500/100 mg plus 2 NRTIs were evaluated under routine clinical care conditions in either antiretroviral-naïve patients or in those with no previous history of antiretroviral treatments and/or genotypic resistance tests suggesting SQV resistance. Plasma SQV trough levels were measured by HPLV-UV. RESULTS. Five hundred and fourteen caucasian patients were included (47.2% coinfected with hepatitis C and/or B virus; 7.8% with cirrhosis). Efficacy at 52 weeks (plasma RNA-HIV <50 copies/ml) was 67.7% (CI95: 63.6 - 71.7%) by intention-to-treat, and 92.2% (CI95: 89.8 - 94.6%) by on-treatment analysis. The reasons for failure were: dropout or loss to follow-up (18.4%), virological failure (7.8%), adverse events (3.1%), and other reasons (4.6%). The high rate of dropout may be explained by an enrollment and follow-up under routine clinical care condition, and a population with a significant number of drug users. The median SQV Cmin (n = 49) was 295 ng/ml (range, 53-2172). The only variable associated with virological failure in the multivariate analysis was adherence (OR: 3.36; CI95, 1.51-7.46, p = 0.003). CONCLUSIONS. Our results suggests that SQVr (1500/100 mg) once-daily plus 2 NRTIs is an effective regimen, without severe clinical adverse events or hepatotoxicity, scarce lipid changes, and no interactions with methadone. All these factors and its once-daily administration suggest this regimen as an appropriate option in patients with no SQV resistance-associated mutations.

Zinc-alpha 2-glycoprotein gene expression in adipose tissue is related with insulin resistance and lipolytic genes in morbidly obese patients.

OBJECTIVE Zinc-α(2) glycoprotein (ZAG) stimulates lipid loss by adipocytes and may be involved in the regulation of adipose tissue metabolism. However, to date no studies have been made in the most extreme of obesity. The aims of this study are to analyze ZAG expression levels in adipose tissue from morbidly obese patients, and their relationship with lipogenic and lipolytic genes and with insulin resistance (IR). METHODS mRNA expression levels of PPARγ, IRS-1, IRS-2, lipogenic and lipolytic genes and ZAG were quantified in visceral (VAT) and subcutaneous adipose tissue (SAT) of 25 nondiabetic morbidly obese patients, 11 with low IR and 14 with high IR. Plasma ZAG was also analyzed. RESULTS The morbidly obese patients with low IR had a higher VAT ZAG expression as compared with the patients with high IR (p = 0.023). In the patients with low IR, the VAT ZAG expression was greater than that in SAT (p = 0.009). ZAG expression correlated between SAT and VAT (r = 0.709, p<0.001). VAT ZAG expression was mainly predicted by insulin, HOMA-IR, plasma adiponectin and expression of adiponectin and ACSS2. SAT ZAG expression was only predicted by expression of ATGL. CONCLUSIONS ZAG could be involved in modulating lipid metabolism in adipose tissue and is associated with insulin resistance. These findings suggest that ZAG may be a useful target in obesity and related disorders, such as diabetes.

Telemedicine influence on the follow-up of type 2 diabetes patients.

OBJECTIVE This study was designed to evaluate the impact of a teleassistance system on the metabolic control of type 2 diabetes patients. RESEARCH DESIGN AND METHODS We conducted a 1-year controlled parallel-group trial comparing patients randomized (1) to an intervention group, assigned to a teleassistance system using real-time transmission of blood glucose results, with immediate reply when necessary, and telephone consultations, or (2) to a control group, being regularly followed-up at their healthcare center. Study subjects were type 2 diabetes patients >30 years of age followed in the primary care setting. RESULTS A total of 328 type 2 diabetes patients were recruited from 35 family practices in the province of Málaga, Spain. There was a reduction in hemoglobin A1c after 12 months from 7.62 +/- 1.60% to 7.40 +/- 1.43% (P = 0.027) in the intervention group and from 7.44 +/- 1.31% to 7.35 +/- 1.38% (P = 0.303) in the control group. The difference in the change between groups was not statistically significant. There was also a significant decrease in systolic and diastolic blood pressure, total cholesterol, low-density lipoprotein cholesterol, and body mass index in the intervention group. In the control group, the only significant decline was in low-density lipoprotein cholesterol. CONCLUSIONS A teleassistance system using real-time transmission of blood glucose results with an option to make telephone consultations is feasible in the primary care setting as a support tool for family physicians in their follow-up of type 2 diabetes patients.

The sustainability of a Spanish Regional Virtual Library

Objectives: The Andalusian Health e-Library (BV-SSPA) is the National Health Library in the region of Andalusia (Spain). It is a corporate hospital library created in 2006. The year 2012 is a turning point for the Spanish economy, and the BV-SSPA has to demonstrate that it is cost-effective and sustainable. Methods: Andalusia is a wide Spanish region with more than 8 million inhabitants, more than 100,000 health professionals for 41 hospitals, 1,500 primary health care centers, and 28 centers for nonmedical attention purposes, and the BV-SSPA was created to cover all these health services. It was appointed the only intermediary for contracting electronic resources destined to the Andalusian Health System. Hospitals are not allowed to subscribe any resources, and the same services are offered for the whole system. Results: In 2011, the BV-SSPA reached the biggest electronic health sciences resource collection in Spain: a total amount of 2,431 subscribed titles, besides 8 databases and other scientific information resources. The following goals were also achieved: • Cost-effectiveness: In 2011, the BV-SSPA represented a saving percentage of 25.42% compared to the individual hospital subscription costs if they would have continued their contracting. • Efficiency: Central purchasing has meant for the Andalusian health professionals, the democracy of research resource access. Some services were also created: • integrated and safe remote access to all the library resources independent of the user’s location • citizenship website, where the resources for citizenship are grouped • Centralized Document Supply Service, focusing all the article orders from and for the Andalusian Health System • institutional repository, which contains the whole intellectual, scientific production generated by the Andalusian health professionals • computer application to study the Andalusian health system scientific production • Social media as instrument for communicating with users • science web, a defined space for researchers. Conclusions: Although Andalusia is facing a dreadful economic situation, the BV-SSPA has demonstrated its sustainability: • For 2012 renewals, it carried out a statistics study allowing obtaining enough data for deciding which titles were not being discharged by users. • Titles with no discharges or without impact factor were rejected after strong negotiation with suppliers, as the BV-SSPA after 6 years on, is considered a strong dealer by them. • This meant savings of 14% from the original budget for 2012, which allowed the continuity of the BV-SSPA without decreasing the quality offered to their users.

Chromosomal divergence and evolutionary inferences in Rhodniini based on the chromosomal location of ribosomal genes

In this study, we used fluorescence in situ hybridisation to determine the chromosomal location of 45S rDNA clusters in 10 species of the tribe Rhodniini (Hemiptera: Reduviidae: Triatominae). The results showed striking inter and intraspecific variability, with the location of the rDNA clusters restricted to sex chromosomes with two patterns: either on one (X chromosome) or both sex chromosomes (X and Y chromosomes). This variation occurs within a genus that has an unchanging diploid chromosome number (2n = 22, including 20 autosomes and 2 sex chromosomes) and a similar chromosome size and genomic DNA content, reflecting a genome dynamic not revealed by these chromosome traits. The rDNA variation in closely related species and the intraspecific polymorphism in Rhodnius ecuadoriensis suggested that the chromosomal position of rDNA clusters might be a useful marker to identify recently diverged species or populations. We discuss the ancestral position of ribosomal genes in the tribe Rhodniini and the possible mechanisms involved in the variation of the rDNA clusters, including the loss of rDNA loci on the Y chromosome, transposition and ectopic pairing. The last two processes involve chromosomal exchanges between both sex chromosomes, in contrast to the widely accepted idea that the achiasmatic sex chromosomes of Heteroptera do not interchange sequences.

Novel polymerase chain reaction-restriction fragment length polymorphism assay to determine internal transcribed spacer-2 group in the Chagas disease vector, Triatoma dimidiata (Latreille, 1811)

Triatoma dimidiata is the most important Chagas disease insect vector in Central America as this species is primarily responsible for Trypanosoma cruzi transmission to humans, the protozoan parasite that causes Chagas disease. T. dimidiata sensu lato is a genetically diverse assemblage of taxa and effective vector control requires a clear understanding of the geographic distribution and epidemiological importance of its taxa. The nuclear ribosomal internal transcribed spacer 2 (ITS-2) is frequently used to infer the systematics of triatomines. However, oftentimes amplification and sequencing of ITS-2 fails, likely due to both the large polymerase chain reaction (PCR) product and polymerase slippage near the 5' end. To overcome these challenges we have designed new primers that amplify only the 3'-most 200 base pairs of ITS-2. This region distinguishes the ITS-2 group for 100% of known T. dimidiata haplotypes. Furthermore, we have developed a PCR-restriction fragment length polymorphism (RFLP) approach to determine the ITS-2 group, greatly reducing, but not eliminating, the number of amplified products that need to be sequenced. Although there are limitations with this new PCR-RFLP approach, its use will help with understanding the geographic distribution of T. dimidiata taxa and can facilitate other studies characterising the taxa, e.g. their ecology, evolution and epidemiological importance, thus improving vector control.

How to manage a virtual library?

Introduction. The Andalusian Public Health System Virtual Library (Biblioteca Virtual del Sistema Sanitario Público de Andalucía, BV-SSPA) was created in June 2006, after being determined by the II Quality Plan in the key process Guarantee the Knowledge Exchange into the Health System which was established by the Strategy IV, Knowledge Management, 2005-2008. It is a government strategy with its own budget and management with the aim of rationalizing the subscriptions into the Andalusian Health System and democratizing the health professional access to qualify scientific information, regardless of the professional workplace. Andalusia is a wide region with more than 8 million inhabitants, more than 90,000 health professionals for 41 hospitals, 1,500 primary healthcare centres, and 12 centres for non-medical attention purposes, and the Virtual Library was created to cover all this Health Services. Before the creation of the BV-SSPA every centre had its own budget and management decisions concerning scientific resources, with the creation of the BV-SSPA both management and budget were centralized. Objectives. With this work we pretend to analyze if the results after these five years have reached the expectations from an economic point of view and determine if really we can offer a benefit to the Andalusian Professional and Society in general. We will demonstrate the following: - The BV-SSPA supposed a cost reduction. It meant cost-effectiveness. - It resulted in Economics of Scale, as we have every year more resources and services investing a minor proportional amount of money. - In terms of Efficiency it implemented more services than the System had before its creation, we a lower budget. Methods. The BV-SSPA was appointed the only intermediary for contracting electronic resources destined to the Andalusian Health System. This had some consequences which should be analyzed: - Hospitals were not allowed to subscribe any resources. - Services offered for the whole System. - A remote access system was created. - Tools to give more visibility to the Public Health System were developed. - Negotiations techniques changed as the BV-SSPA is stronger than individual hospitals. Results. - The amount of 2,431 electronic reviews, 8 data bases and other scientific information resources at the disposal of the Andalusian Health System Professionals and available worldwide requiring only an internet connection. Before the BV-SSPA, 5,267 titles were subscribed by hospital and 2,967 of them were subscribed repeatedly (by two or more hospitals), this represented more than 55%. The rationalization of the subscription investment has been reached. - The establishment of several important scientific services for the whole territory of Andalusia, not only big hospitals. - The use of appropriate tools through a Web 2.0 and Social Media to be acknowledged by most National Health Professionals. Conclusions. It has been demonstrated that the BV-SSPA has become the Central Unit for purchasing, offering librarian services and a reference for users in terms of knowledge management, but from the point of view of business it has also obtained the following results: - Cost-Effectiveness: Its budget for subscriptions is lower than the hospital former one in a 30% and now more electronic resources are available. - Economics of Scale: Near 95,000 health professionals can access this Virtual Library in 2010. Before its creation Professionals for small hospital and Primary Care centres were not able to access to scientific information subscribed by big hospitals. - Efficiency Besides the central electronic purchasing, services were created for the System, without increasing the expenses: - Remote access to all the library resources independent of the user’s location. The BV-SSPA usage increased in a 147% in 2008, when it was installed. - The Document Supply Service implemented in 2009. - The Institutional Repository which contains the whole intellectual, scientific production generated by the Andalusian Public Health Professionals as a result of their healthcare, research or managing activity. - The creation of an application developed by the BV-SSPA to study the Andalusian Health System Scientific Production. - The visibility of the Andalusian Health System reached thanks to the BV-SSPA, through the numerous events in which it participates and organizes such as the 2nd. European National Digital Libraries of Health Conferences and the National Conference of Health Science Information and Documentation held in Cadiz in 2010; and its profile in social media where it can be contacted by citizens and health professionals all over the world. - Negotiation with electronic resource suppliers is much more advantageous as the BV-SSPA is stronger to deal with them thanks to its consolidated budget, its managing independence and its visibility.

Dipeptidyl peptidase IV and its inhibitors: therapeutics for type 2 diabetes and what else?

The proline-specific dipeptidyl aminopeptidase IV (DPP IV, DPP-4, CD26), widely expressed in mammalians, releases X-Pro/Ala dipeptides from the N-terminus of peptides. DPP IV is responsible of the degradation of the incretin peptide hormones regulating blood glucose levels. Several families of DPP IV inhibitors have been synthesized and evaluated. Their positive effects on the degradation of the incretins and the control of blood glucose levels have been demonstrated in biological models and in clinical trials. Presently, several DPP IV inhibitors, the "gliptins", are approved for type 2 diabetes or are under clinical evaluation. However, the gliptins may also be of therapeutic interest for other diseases beyond the inhibition of incretin degradation. In this Perspective, the biological functions and potential substrates of DPP IV enzymes are reviewed and the characteristics of the DPP IV inhibitors are discussed in view of type 2 diabetes and further therapeutic interest.

Megazol and its bioisostere 4H-1,2,4-triazole: comparing the trypanocidal, cytotoxic and genotoxic activities and their in vitro and in silico interactions with the Trypanosoma brucei nitroreductase enzyme

Megazol (7) is a 5-nitroimidazole that is highly active against Trypanosoma cruzi and Trypanosoma brucei, as well as drug-resistant forms of trypanosomiasis. Compound 7 is not used clinically due to its mutagenic and genotoxic properties, but has been largely used as a lead compound. Here, we compared the activity of 7 with its 4H-1,2,4-triazole bioisostere (8) in bloodstream forms of T. brucei and T. cruzi and evaluated their activation by T. brucei type I nitroreductase (TbNTR) enzyme. We also analysed the cytotoxic and genotoxic effects of these compounds in whole human blood using Comet and fluorescein diacetate/ethidium bromide assays. Although the only difference between 7 and 8 is the substitution of sulphur (in the thiadiazole in 7) for nitrogen (in the triazole in 8), the results indicated that 8 had poorer antiparasitic activity than 7 and was not genotoxic, whereas 7 presented this effect. The determination of Vmax indicated that although 8 was metabolised more rapidly than 7, it bounds to the TbNTR with better affinity, resulting in equivalent kcat/KM values. Docking assays of 7 and 8 performed within the active site of a homology model of the TbNTR indicating that 8 had greater affinity than 7.

Peripheral arterial disease, type 2 diabetes and postprandial lipidaemia: Is there a link?

Peripheral arterial disease, manifested as intermittent claudication or critical ischaemia, or identified by an ankle/brachial index < 0.9, is present in at least one in every four patients with type 2 diabetes mellitus. Several reasons exist for peripheral arterial disease in diabetes. In addition to hyperglycaemia, smoking and hypertension, the dyslipidaemia that accompanies type 2 diabetes and is characterised by increased triglyceride levels and reduced high-density lipoprotein cholesterol concentrations also seems to contribute to this association. Recent years have witnessed an increased interest in postprandial lipidaemia, as a result of various prospective studies showing that non-fasting triglycerides predict the onset of arteriosclerotic cardiovascular disease better than fasting measurements do. Additionally, the use of certain specific postprandial particle markers, such as apolipoprotein B-48, makes it easier and more simple to approach the postprandial phenomenon. Despite this, only a few studies have evaluated the role of postprandial triglycerides in the development of peripheral arterial disease and type 2 diabetes. The purpose of this review is to examine the epidemiology and risk factors of peripheral arterial disease in type 2 diabetes, focusing on the role of postprandial triglycerides and particles.

Sandfly species diversity in association with human activities in the Kani tribe settlements of the Western Ghats, Thiruvananthapuram, Kerala, India

Sandfly prevalence in the Kani tribe settlements of Western Ghats in India was investigated. A total of 1,279 sandflies comprising 17 species was obtained. Sandfly abundance showed a negative correlation (r = -0.97, p = 0.003) with increase in altitudinal ranges from 0-1,000 m. When sandfly samples were grouped according to landscape characteristics of the location, the estimated Shannon-Weiner index (H) and species richness index (S) were high and species evenness index (J) was low in settlements located at 0-300 m altitudinal range. On the contrary, the values of H and J were high, while S was low at 301-600 m altitudinal range. With further increase in altitude, species diversity, S and J were low. Though the relative abundance of sandflies decreased with increase in altitude, the influence of altitudinal variation could not be attributed to determine sandfly diversity, since the number of sampling units were not uniform at all the altitudinal gradients due to nonavailability of suitable resting shelters. Sandfly species showed great aggregation at 0-300 m altitude interval, where not only the number of settlements were maximum (n = 19), but also the environmental conditions favoured sandfly abundance due to the concentration of tribal settlements, human dwellings and his activities.

Comparison of skin microvascular reactivity with hemostatic markers of endothelial dysfunction and damage in type 2 diabetes.

AIM: Patients with non-insulin-dependent diabetes mellitus (NIDDM) are at increased cardiovascular risk due to an accelerated atherosclerotic process. The present study aimed to compare skin microvascular function, pulse wave velocity (PWV), and a variety of hemostatic markers of endothelium injury [von Willebrand factor (vWF), plasminogen activator inhibitor-1 (PAI-1), tissue plasminogen activator (t-PA), tissue factor pathway inhibitor (TFPI), and the soluble form of thrombomodulin (s-TM)] in patients with NIDDM. METHODS: 54 patients with NIDDM and 38 sex- and age-matched controls were studied. 27 diabetics had no overt micro- and/or macrovascular complications, while the remainder had either or both. The forearm skin blood flow was assessed by laser-Doppler imaging, which allowed the measurement of the response to iontophoretically applied acetylcholine (endothelium-dependent vasodilation) and sodium nitroprusside (endothelium-independent vasodilation), as well as the reactive hyperemia triggered by the transient occlusion of the circulation. RESULTS: Both endothelial and non-endothelial reactivity were significantly blunted in diabetics, regardless of the presence or the absence of vascular complications. Plasma vWF, TFPI and s-TM levels were significantly increased compared with controls only in patients exhibiting vascular complications. Concentrations of t-PA and PAI-1 were significantly increased in the two groups of diabetics versus controls. CONCLUSION: In NIDDM, both endothelium-dependent and -independent microvascular skin reactivity are impaired, whether or not underlying vascular complications exist. It also appears that microvascular endothelial dysfunction is not necessarily associated in NIDDM with increased circulating levels of hemostatic markers of endothelial damage known to reflect a hypercoagulable state.

Effect of length and location of heterologous sequences on RecA-mediated strand exchange.

We systematically investigated the effect of heterology on RecA-mediated strand exchange between double-stranded linear and single-stranded circular DNA. Strand exchange took place through heterologies of up to 150-200 base pairs when the insertion was at the proximal (initiating) end of the duplex DNA but was completely blocked by an insert of only 22 base pairs placed at the distal end of the duplex. In the case of medial heterology created by insertion either in the duplex or the single-stranded DNA, the ability of RecA to exchange strands decreased as the heterology was shifted toward the distal end of the duplex. These results suggest that two different strand exchange mechanisms operate in the proximal and distal portions of the duplex substrate.

Expression of mitofusin 2(R94Q) in a transgenic mouse leads to Charcot-Marie-Tooth neuropathy type 2A.

Charcot-Marie-Tooth disease type 2A is an autosomal dominant axonal form of peripheral neuropathy caused by mutations in the mitofusin 2 gene. Mitofusin 2 encodes a mitochondrial outer membrane protein that participates in mitochondrial fusion in mammalian cells. How mutations in this protein lead to Charcot-Marie-Tooth disease type 2A pathophysiology remains unclear. We have generated a transgenic mouse expressing either a mutated (R94Q) or wild-type form of human mitofusin 2 in neurons to evaluate whether the R94Q mutation was sufficient for inducing a Charcot-Marie-Tooth disease type 2A phenotype. Only mice expressing mitofusin 2(R94Q) developed locomotor impairments and gait defects thus mimicking the Charcot-Marie-Tooth disease type 2A neuropathy. In these animals, the number of mitochondria per axon was significantly increased in the distal part of the sciatic nerve axons with a diameter smaller than 3.5 microm. Importantly, the analysis of R94Q transgenic animals also revealed an age-related shift in the size of myelinated axons leading to an over-representation of axons smaller than 3.5 microm. Together these data suggest a link between an increased number of mitochondria in axons and a shift in axonal size distribution in mitofusin 2(R94Q) transgenic animals that may contribute to their neurological phenotype.