Isozymes from the herbivorous gecarcinid land crab, Gecarcoidea natalis that possess both lichenase and endo-β-1,4-glucanase activity

Three isozymes with both lichenase and endo-β-1,4-glucanase activity were purified and characterised from the midgut gland of the herbivorous gecarcinid land crab, Gecarcoidea natalis. The three isozymes, termed 1a, 1b and 2, had respective molecular masses of 53 ± 0 (3), 43 ± 0 (3) and 47.4 ± 0(3) kDa. All isozymes possessed similar V(max) values and thus hydrolysed both carboxy methyl cellulose and lichenan equally. Furthermore the chromatography profiles for lichenase activities mirrored that for endo-β-1,4-glucanase activities suggesting that the same enzyme possessed both activities. Given this, the endo-β-1,4-glucanase enzymes described for other animals, may, like the isozymes described in this study, may be able to hydrolyse lichenan. However this ability needs to be confirmed. The main digestive function of these isozymes may be to hydrolyse hemicelluloses such as lichenan and mixed beta-D-glucan. All three isozymes randomly hydrolysed internal glycosidic bonds within carboxy methyl cellulose and lichenan to release short oligomers of 4-5 glucose units in length. They also hydrolysed cellotetraose to either two units of cellobiose or cellotriose and glucose. Cellotriose was hydrolysed to cellobiose and glucose. All three enzymes lacked β-1,4-glucosidase activity as they could not hydrolyse cellobiose.     

Heterogeneous vancomycin-intermediate susceptibility in a community-associated methicillin-resistant Staphylococcus aureus epidemic clone, in a case of Infective Endocarditis in Argentina

Background

There has been considerable effort to discover plant-derived antibacterials against methicillin-resistant strains of Staphylococcus aureus (MRSA) which have developed resistance to most existing antibiotics, including the last line of defence, vancomycin. Pentacyclic triterpenoid, a biologically diverse plant-derived natural product, has been reported to show anti-staphylococcal activities. The objective of this study is to evaluate the interaction between three pentacyclic triterpenoid and standard antibiotics (methicillin and vancomycin) against reference strains of Staphylococcus aureus.

Methods and Results

The activity of the standard antibiotics and compounds on reference methicillin-sensitive and resistant strains of S. aureus were determined using the macrodilution broth method. The minimum inhibitory concentration (MIC) of the compounds was compared with that of the standard antibiotics. The interaction between any two antimicrobial agents was estimated by calculating the fractional inhibitory concentration (FIC index) of the combination. The various combinations of antibiotics and compounds reduced the MIC to a range of 0.05 to 50%.

Conclusion

Pentacyclic triterpenoids have shown anti-staphylococcal activities and although individually weaker than common antibiotics produced from bacteria and fungi, synergistically these compounds may use different mechanism of action or pathways to exert their antimicrobial effects, as implicated in the lowered MICs. Therefore, the use of current antibiotics could be maintained in their combination with plant-derived antibacterial agents as a therapeutic option in the treatment of S. aureus infections.     

AT1A angiotensin receptors in the renal proximal tubule regulate blood pressure

Hypertension affects more than 1.5 billion people worldwide but the precise cause of elevated blood pressure (BP) cannot be determined in most affected individuals. Nonetheless, blockade of the renin-angiotensin system (RAS) lowers BP in the majority of patients with hypertension. Despite its apparent role in hypertension pathogenesis, the key cellular targets of the RAS that control BP have not been clearly identified. Here we demonstrate that RAS actions in the epithelium of the proximal tubule have a critical and nonredundant role in determining the level of BP. Abrogation of AT(1) angiotensin receptor signaling in the proximal tubule alone is sufficient to lower BP, despite intact vascular responses. Elimination of this pathway reduces proximal fluid reabsorption and alters expression of key sodium transporters, modifying pressure-natriuresis and providing substantial protection against hypertension. Thus, effectively targeting epithelial functions of the proximal tubule of the kidney should be a useful therapeutic strategy in hypertension.     

Neonatal DNA methylation patterns associate with gestational age

Risk for adverse neonatal outcome increases with declining gestational age (GA), and changes in DNA methylation may contribute to the relationship between GA and adverse health outcomes in offspring. To test this hypothesis, we evaluated the association between GA and more than 27,000 CpG sites in neonatal DNA extracted from umbilical cord blood from two prospectively-characterized cohorts: (1) a discovery cohort consisting of 259 neonates from women with a history of neuropsychiatric disorders and (2) a replication cohort consisting of 194 neonates of uncomplicated mothers. GA was determined by obstetrician report and maternal last menstrual period. The associations between proportion of DNA methylated and GA were evaluated by fitting a separate linear mixed effects model for each CpG site, adjusting for relevant covariates including neonatal sex, race, parity, birth weight percentile and chip effects. CpG sites in 39 genes were associated with GA (false discovery rate < 0.05) in the discovery cohort. The same CpG sites in 25 of these genes replicated in the replication cohort, with each association replicating in the same direction. Notably, these CpG sites were located in genes previously implicated in labor and delivery (e.g., AVP, OXT, CRHBP and ESR1) or that may influence the risk for adverse health outcomes later in life (e.g., DUOX2, TMEM176A and CASP8). All associations were independent of method of delivery or induction of labor. These results suggest neonatal DNA methylation varies with GA even in term deliveries. The potential contribution of these changes to clinically significant postnatal outcomes warrants further investigation.     

Promotional tone in reviews of menopausal hormone therapy after the Women's Health Initiative: an analysis of published articles

Background

Even after the Women''s Health Initiative (WHI) found that the risks of menopausal hormone therapy (hormone therapy) outweighed benefit for asymptomatic women, about half of gynecologists in the United States continued to believe that hormones benefited women''s health. The pharmaceutical industry has supported publication of articles in medical journals for marketing purposes. It is unknown whether author relationships with industry affect promotional tone in articles on hormone therapy. The goal of this study was to determine whether promotional tone could be identified in narrative review articles regarding menopausal hormone therapy and whether articles identified as promotional were more likely to have been authored by those with conflicts of interest with manufacturers of menopausal hormone therapy.

Methods and Findings

We analyzed tone in opinion pieces on hormone therapy published in the four years after the estrogen-progestin arm of the WHI was stopped. First, we identified the ten authors with four or more MEDLINE-indexed reviews, editorials, comments, or letters on hormone replacement therapy or menopausal hormone therapy published between July 2002 and June 2006. Next, we conducted an additional search using the names of these authors to identify other relevant articles. Finally, after author names and affiliations were removed, 50 articles were evaluated by three readers for scientific accuracy and for tone. Scientific accuracy was assessed based on whether or not the findings of the WHI were accurately reported using two criteria: (1) Acknowledgment or lack of denial of the risk of breast cancer diagnosis associated with hormone therapy, and (2) acknowledgment that hormone therapy did not benefit cardiovascular disease endpoints. Determination of promotional tone was based on the assessment by each reader of whether the article appeared to promote hormone therapy. Analysis of inter-rater consistency found moderate agreement for scientific accuracy (κ = 0.57) and substantial agreement for promotional tone (κ = 0.65). After discussion, readers found 86% of the articles to be scientifically accurate and 64% to be promotional in tone. Themes that were common in articles considered promotional included attacks on the methodology of the WHI, arguments that clinical trial results should not guide treatment for individuals, and arguments that observational studies are as good as or better than randomized clinical trials for guiding clinical decisions. The promotional articles we identified also implied that the risks associated with hormone therapy have been exaggerated and that the benefits of hormone therapy have been or will be proven. Of the ten authors studied, eight were found to have declared payment for speaking or consulting on behalf of menopausal hormone manufacturers or for research support (seven of these eight were speakers or consultants). Thirty of 32 articles (90%) evaluated as promoting hormone therapy were authored by those with potential financial conflicts of interest, compared to 11 of 18 articles (61%) by those without such conflicts (p = 0.0025). Articles promoting the use of menopausal hormone therapy were 2.41 times (95% confidence interval 1.49–4.93) as likely to have been authored by authors with conflicts of interest as by authors without conflicts of interest. In articles from three authors with conflicts of interest some of the same text was repeated word-for-word in different articles.

Conclusion

There may be a connection between receiving industry funding for speaking, consulting, or research and the publication of promotional opinion pieces on menopausal hormone therapy. Please see later in the article for the Editors'' Summary     

The role of combined assessment of defense against oxidative stress and inflammation in the evaluation of peripheral arterial disease

Atherosclerosis in symptomatic peripheral arterial disease affects wide portions of numerous arteries in lower extremities. The resulting active inflammation in a considerable amount of arterial tissue facilitates systemic detection via measurement of inflammation-related variables. We reasoned that the combined assessment of defense against oxidative stress, in the form of paraoxonase-1 (PON1), and monocyte migration measured as circulating (C-C motif) ligand 2 (CCL2), may play a role in the evaluation of these patients. Plasma CCL2 and serum PON1-related variables, assessed by their interaction with functional genetic variants, were measured in a cross-sectional study in patients with symptomatic PAD. We found that PON1 activity and concentration were significantly lower and CCL2 concentration higher in PAD patients compared to controls, that the combination of plasma CCL2 and PON1- related values, especially PON1 concentration differentiated, almost perfectly, controls from patients and that the expression of CCL2 and PON1 generally co-localized in the atherosclerotic lesion. Since no association with genetic variants was found, such a relationship is probably the result of the disease. Our data suggest a coordinated role between CCL2 and PON1 that may be detected in blood with simple measurements and may represent an indicator of the extent of atherosclerosis.     

Function and structure of GFP-like proteins in the protein data bank

The RCSB protein databank contains 266 crystal structures of green fluorescent proteins (GFP) and GFP-like proteins. This is the first systematic analysis of all the GFP-like structures in the pdb. We have used the pdb to examine the function of fluorescent proteins (FP) in nature, aspects of excited state proton transfer (ESPT) in FPs, deformation from planarity of the chromophore and chromophore maturation. The conclusions reached in this review are that (1) The lid residues are highly conserved, particularly those on the "top" of the β-barrel. They are important to the function of GFP-like proteins, perhaps in protecting the chromophore or in β-barrel formation. (2) The primary/ancestral function of GFP-like proteins may well be to aid in light induced electron transfer. (3) The structural prerequisites for light activated proton pumps exist in many structures and it's possible that like bioluminescence, proton pumps are secondary functions of GFP-like proteins. (4) In most GFP-like proteins the protein matrix exerts a significant strain on planar chromophores forcing most GFP-like proteins to adopt non-planar chromophores. These chromophoric deviations from planarity play an important role in determining the fluorescence quantum yield. (5) The chemospatial characteristics of the chromophore cavity determine the isomerization state of the chromophore. The cavities of highlighter proteins that can undergo cis/trans isomerization have chemospatial properties that are common to both cis and trans GFP-like proteins.     

Growth factor-enriched autologous plasma improves wound healing after surgical debridement in odontogenic necrotizing fasciitis: a case report

Introduction

Intracranial tuberculomas are a rare complication of tuberculosis occurring through hematogenous spread from an extracranial source, most often of pulmonary origin. Testicular tuberculosis with only intracranial spread is an even rarer finding and to the best of our knowledge, has not been reported in the literature. Clinical suspicion or recognition and prompt diagnosis are important because early treatment can prevent patient deterioration and lead to clinical improvement.

Case presentation

We present the case of a 51-year-old African man with testicular tuberculosis and multiple intracranial tuberculomas who was initially managed for testicular cancer with intracranial metastasis. He had undergone left radical orchidectomy, but subsequently developed hemiparesis and lost consciousness. Following histopathological confirmation of the postoperative sample as chronic granulomatous infection due to tuberculosis, he sustained significant clinical improvement with antituberculous therapy, recovered fully and was discharged at two weeks post-treatment.

Conclusion

The clinical presentation of intracranial tuberculomas from an extracranial source is protean, and delayed diagnosis could have devastating consequences. The need to have a high index of suspicion is important, since neuroimaging features may not be pathognomonic.     

Discovery and characterization of single-nucleotide polymorphisms in steelhead/rainbow trout, Oncorhynchus mykiss

Single-nucleotide polymorphisms (SNPs) have several advantages over other genetic markers, including lower mutation and genotyping error rates, ease of inter-laboratory standardization, and the prospect of high-throughput, low-cost genotyping. Nevertheless, their development and use has only recently moved beyond model organisms to groups such as salmonid fishes. Oncorhynchus mykiss is a salmonid native to the North Pacific rim that has now been introduced throughout the world for fisheries and aquaculture. The anadromous form of the species is known as steelhead. Native steelhead populations on the west coast of the United States have declined and many now have protected status. The nonanadromous, or resident, form of the species is termed rainbow, redband or golden trout. Additional life history and morphological variation, and interactions between the forms, make the species challenging to study, monitor and evaluate. Here, we describe the discovery, characterization and assay development for 139 SNP loci in steelhead/rainbow trout. We used EST sequences from existing genomic databases to design primers for 480 genes. Sanger-sequencing products from these genes provided 130 KB of consensus sequence in which variation was surveyed for 22 individuals from steelhead, rainbow and redband trout groups. The resulting TaqMan assays were surveyed in five steelhead populations and three rainbow trout stocks, where they had a mean minor allele frequency of 0.15-0.26 and observed heterozygosity of 0.18-0.35. Mean F(ST) was 0.204. The development of SNPs for O. mykiss will help to provide highly informative genetic tools for individual and stock identification, pedigree reconstruction, phylogeography and ecological investigation.     

Effect of dsRNA on growth rate and reproductive potential of Monosporascus cannonballus

The effect of double stranded RNA (dsRNA) infection on growth rate and the reproductive potential of Monosporascus cannonballus was studied in 21 isolates collected in cucurbit growing areas of Spain and Tunisia. The isolates were incubated on potato dextrose agar (PDA) under different conditions of temperature, pH, and water potential (Ψ(s)). They showed optimal growth temperatures over the range of 27-34°C and perithecia formation was obtained mainly at 25 and 30°C, although some isolates were able to produce perithecia at 35°C. All isolates were able to produce perithecia in a broad range of pHs (4-8). Regarding the effect of Ψ(s,) the isolates were more tolerant to grow on KCl than on NaCl. For each solute, radial growth decreased progressively as Ψ(s) decreased and was severely limited at -5.0 to -6.0MPa. Perithecia formation was highest at -0.5MPa, decreased at -1.0MPa and occurred just in some isolates at -2.0MPa. Nine of the M. cannonballus isolates harboured dsRNA with 2-6 bands each and a size range of 1.9-18.0Kb. Phenotypical data were subjected to multivariate factorial analysis. Most of the isolates clustered in two groups corresponding with the presence/absence of dsRNA elements. Isolates without detectable dsRNA produced more perithecia. However, isolates with dsRNA produced lower number of perithecia depending on the pH, Ψ(s,) or solute used. These results improve our understanding of the behaviour and growth of this pathogen in soil, and can be useful to implement effective disease control.