Evidence against Wolbachia symbiosis in Loa loa

BACKGROUND: The majority of filarial nematode species are host to Wolbachia bacterial endosymbionts, although a few including Acanthocheilonema viteae, Onchocerca flexuosa and Setaria equina have been shown to be free of infection. Comparisons of species with and without symbionts can provide important information on the role of Wolbachia symbiosis in the biology of the nematode hosts and the contribution of the bacteria to the development of disease. Previous studies by electron microscopy and PCR have failed to detect intracellular bacterial infection in Loa loa. Here we use molecular and immunohistological techniques to confirm this finding. METHODS: We have used a combination of PCR amplification of bacterial genes (16S ribosomal DNA [rDNA], ftsZ and Wolbachia surface protein [WSP]) on samples of L. loa adults, third-stage larvae (L3) and microfilariae (mf) and immunohistology on L. loa adults and mf derived from human volunteers to determine the presence or absence of Wolbachia endosymbionts. Samples used in the PCR analysis included 5 adult female worms, 4 adult male worms, 5 mf samples and 2 samples of L3. The quality and purity of nematode DNA was tested by PCR amplification of nematode 5S rDNA and with diagnostic primers from the target species and used to confirm the absence of contamination from Onchocerca sp., Mansonella perstans, M. streptocerca and Wuchereria bancrofti. Immunohistology was carried out by light and electron microscopy on L. loa adults and mf and sections were probed with rabbit antibodies raised to recombinant Brugia malayi Wolbachia WSP. Samples from nematodes known to be infected with Wolbachia (O. volvulus, O. ochengi, Litomosoides sigmodontis and B. malayi) were used as positive controls and A. viteae as a negative control. RESULTS: Single PCR analysis using primer sets for the bacterial genes 16S rDNA, ftsZ, and WSP were negative for all DNA samples from L. loa. Positive PCR reactions were obtained from DNA samples derived from species known to be infected with Wolbachia, which confirmed the suitability of the primers and PCR conditions. The quality and purity of nematode DNA samples was verified by PCR amplification of 5S rDNA and with nematode diagnostic primers. Additional analysis by 'long PCR' failed to produce any further evidence for Wolbachia symbiosis. Immunohistology of L. loa adults and mf confirmed the results of the PCR with no evidence for Wolbachia symbiosis. CONCLUSION: DNA analysis and immunohistology provided no evidence for Wolbachia symbiosis in L. loa

Recruiting and Preparing skilled personnel for leadership roles in welding and brazing

A shortage of welders and welding professionals is felt globally, and it will worsen as the current skilled and educated leave the workforce. Thus, many countries are actively designing programs to improve the image of welding and to train and educate persons to meet those needs. Virtual welding, by means of computer simulation, is one method of introducing and exciting the young about welding. Some companies are even using the virtual welder as to test or even give basic training to new employees. Females are 50% of the population, yet too few choose welding. We have good role models in the many different areas of welding and they are highlighted here. Once persons are interested in welding, they need to be properly trained and educated. Weld-Ed is a program in the USA that has 1) a model curriculum for 2-year colleges; 2) a program to update and upgrade instructors; 3) a method of pairing industry with schools and colleges to offer necessary skills and knowledge for available jobs. New technology is being used by several countries in a variety of ways to enhance training and education. Several types, including online learning and electronic devices, will be described. As persons become skilled and educated, they need a way to prove their competence. A cost-effective means of demonstrating their competence is a Certification Program. Bright young persons are needed in welding science and technology to meet national and global challenges. Our future, structures, and infrastructure depend on them

Stability of Closed Timelike Curves in Goedel Universe

We study, in some detail, the linear stability of closed timelike curves in the Goedel metric. We show that these curves are stable. We present a simple extension (deformation) of the Goedel metric that contains a class of closed timelike curves similar to the ones associated to the original Goedel metric. This extension correspond to the addition of matter whose energy-momentum tensor is analyzed. We find the conditions to have matter that satisfies the usual energy conditions. We study the stability of closed timelike curves in the presence of usual matter as well as in the presence of exotic matter (matter that does satisfy the above mentioned conditions). We find that the closed timelike curves in Goedel universe with or whithout the inclusion of regular or exotic matter are also stable under linear perturbations. We also find a sort of structural stability.Comment: 12 pages, 11 figures, RevTex, several typos corrected. GRG, in pres

Repurposing of approved drugs from the human pharmacopoeia to target Wolbachia endosymbionts of onchocerciasis and lymphatic filariasis

AbstractLymphatic filariasis and onchocerciasis are debilitating diseases caused by parasitic filarial nematodes infecting around 150 million people throughout the tropics with more than 1.5 billion at risk. As with other neglected tropical diseases, classical drug-discovery and development is lacking and a 50year programme of macrofilaricidal discovery failed to deliver a drug which can be used as a public health tool. Recently, antibiotic targeting of filarial Wolbachia, an essential bacterial symbiont, has provided a novel drug treatment for filariasis with macrofilaricidal activity, although the current gold-standard, doxycycline, is unsuitable for use in mass drug administration (MDA). The anti-Wolbachia (A·WOL) Consortium aims to identify novel anti-Wolbachia drugs, compounds or combinations that are suitable for use in MDA. Development of a Wolbachia cell-based assay has enabled the screening of the approved human drug-pharmacopoeia (∼2600 drugs) for a potential repurposing. This screening strategy has revealed that approved drugs from various classes show significant bacterial load reduction equal to or superior to the gold-standard doxycycline, with 69 orally available hits from different drug categories being identified. Based on our defined hit criteria, 15 compounds were then selectively screened in a Litomosoides sigmodontis mouse model, 4 of which were active. These came from the tetracycline, fluoroquinolone and rifamycin classes. This strategy of repurposing approved drugs is a promising development in the goal of finding a novel treatment against filariasis and could also be a strategy applicable for other neglected tropical diseases

Spinning Strings, Black Holes and Stable Closed Timelike Geodesics

The existence and stability under linear perturbation of closed timelike curves in the spacetime associated to Schwarzschild black hole pierced by a spinning string are studied. Due to the superposition of the black hole, we find that the spinning string spacetime is deformed in such a way to allow the existence of closed timelike geodesics.Comment: 5 pages, RevTex4, some corrections and new material adde

Pooled analysis of Phase III trials indicate contrasting influences of renal function on blood pressure, body weight, and HbA1c reductions with empagliflozin

Sodium glucose cotransporter 2 (SGLT2) inhibitors reduce HbA1c, blood pressure, and weight in patients with type 2 diabetes. To investigate the effect of renal function on reductions in these parameters with the SGLT2 inhibitor empagliflozin, we assessed subgroups by baseline estimated glomerular filtration rate (eGFR; Modification of Diet in Renal Disease) in pooled data from five 24-week trials of 2286 patients with type 2 diabetes randomized to empagliflozin or placebo. Reductions in HbA1c with empagliflozin versus placebo significantly diminished with decreasing baseline eGFR. Reductions in systolic blood pressure (SBP) with empagliflozin were maintained in patients with lower eGFR. The mean placebo-corrected changes from baseline in systolic blood pressure at week 24 with empagliflozin were -3.2 (95% confidence interval -4.9,-1.5) mmHg, -4.0 (-5.4, -2.6) mmHg, -5.5 (-7.6, -3.4) mmHg, and -6.6 (-11.4, -1.8) mmHg in patients with an eGFR of 90 or more, 60 to 89, 30 to 59, and under 30 ml/min/1.73m(2), respectively. Similar trends were observed for diastolic blood pressure. Weight loss with empagliflozin versus placebo tended to be attenuated in patients with a lower eGFR. Results were consistent in a 12-week ambulatory blood pressure monitoring trial in 823 patients with type 2 diabetes and hypertension. Thus, unlike HbA1c reductions, systolic blood pressure and weight reductions with empagliflozin are generally preserved in patients with chronic kidney disease.Peer reviewe

The effect of sodium glucose cotransporter 2 inhibition with empagliflozin on microalbuminuria and macroalbuminuria in patients with type 2 diabetes

Aims/hypothesis Sodium glucose cotransporter 2 (SGLT2) inhibition lowers HbA(1c), systolic BP (SBP) and weight in patients with type 2 diabetes and reduces renal hyperfiltration associated with type 1 diabetes, suggesting decreased intraglomerular hypertension. As lowering HbA(1c), SBP, weight and intraglomerular pressure is associated with antialbuminuric effects in diabetes, we hypothesised that SGLT2 inhibition would reduce the urine albumin-to-creatinine ratio (UACR) to a clinically meaningful extent. Methods We examined the effect of the SGLT2 inhibitor empagliflozin on UACR by pooling data from patients with type 2 diabetes and prevalent microalbuminuria (UACR=30-300 mg/g; n = 636) or macroalbuminuria (UACR>300 mg/g; n=215) who participated in one of five phase III randomised clinical trials. Primary assessment was defined as percentage change in geometric mean UACR from baseline to week 24. Results After controlling for clinical confounders including baseline log-transformed UACR, HbA(1c), SBP and estimated GFR (according to the Modification of Diet in Renal Disease [MDRD] formula), treatment with empagliflozin significantly reduced UACR in patients with microalbuminuria (-32% vs placebo; p Conclusions/interpretation In patients with type 2 diabetes and either micro-or macroalbuminuria, empagliflozin reduced UACR by a clinically meaningful amount. This effect was largely independent of the known metabolic or systemic haemodynamic effects of this drug class. Our results further support a direct renal effect of SGLT2 inhibitors. Prospective studies are needed to explore the potential of this intervention to alter the course of kidney disease in high-risk patients with diabetes. Trial registration: Clinicaltrials.gov NCT01177813 (study 1); NCT01159600 (study 2); NCT01159600 (study 3); NCT01210001 (study 4); and NCT01164501 (study 5).Peer reviewe

Goedel-type Universes and the Landau Problem

We point out a close relation between a family of Goedel-type solutions of 3+1 General Relativity and the Landau problem in S^2, R^2 and H_2; in particular, the classical geodesics correspond to Larmor orbits in the Landau problem. We discuss the extent of this relation, by analyzing the solutions of the Klein-Gordon equation in these backgrounds. For the R^2 case, this relation was independently noticed in hep-th/0306148. Guided by the analogy with the Landau problem, we speculate on the possible holographic description of a single chronologically safe region.Comment: Latex, 21 pages, 1 figure. v2 missing references to previous work on the subject adde

Simultaneous genome sequencing of symbionts and their hosts

Second-generation sequencing has made possible the sequencing of genomes of interest for even small research groups. However, obtaining separate clean cultures and clonal or inbred samples of metazoan hosts and their bacterial symbionts is often difficult. We present a computational pipeline for separating metazoan and bacterial DNA in silico rather than at the bench. The method relies on the generation of deep coverage of all the genomes in a mixed sample using Illumina short-read sequencing technology, and using aggregate properties of the different genomes to identify read sets belonging to each. This inexpensive and rapid approach has been used to sequence several nematode genomes and their bacterial endosymbionts in the last year in our laboratory and can also be used to visualize and identify unexpected contaminants (or possible symbionts) in genomic DNA samples. We hope that this method will enable researchers studying symbiotic systems to move from gene-centric to genome-centric approaches

Opening the black box of under-health people: the case of Spain

ABSTRACT: The most famous modern definition of health was created during a Preamble to the Constitution of the World Health Organization in 1946: "Health is a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity." This definition has not been amended and, since then, many indicators have been proposed to measure health such as Self-Assessed Health (SAH) status. It provides an overall measure of a population's health based on individuals' personal perceptions of their own health. In this paper, we focus our analysis on "under-health" as the fact of having a level that falls behind the health requirements necessary to perform what is considered an "expected life based on Self Assessed Health". For Spain using the European Union Statistics on Income and Living Conditions (EU-SILC), we can confirm there exist under-healthy people by occupation, age group and sex. Additionally, under-healthy workers are most likely to be found among skilled agricultural, fishery workers and elementary occupations