Size-spectra as indicators of the effects of fishing on coral reef fish assemblages

The data requirements and resources needed to develop multispecies indicators of fishing impacts are often lacking and this is particularly true for coral reef fisheries. Size-spectra, relationships between abundance and body-size class, regardless of taxonomy, can be calculated from simple sizeabundance data. Both the slope and the mid-point height of the relationship can be compared at different fishing intensities. Here, we develop size-spectra for reef fish assemblages using body size- abundance data collected by underwater visual census in each of ten fishing grounds across a known gradient of fishing intensity in the Kadavu Island group, Fiji. Slopes of the size-spectra became steeper (F_9,69=3.20, p<0.01) and the height declined (F_9,69=15.78, p<0.001) with increasing fishing intensity. Regressions of numbers of individuals per size class across grounds were negative for all size classes, although the slope was almost zero for the smallest size class. Response to exploitation of each size class category was greatest for larger fish. Steepening of the slope with increasing fishing intensity largely resulted from reductions in the relative abundance of large fish and not from the ecological release of small fish following depletion of their predators. The slope and height of the size-spectrum appear to be good indicators of fishing effects on reef fish assemblages.     

Molecular approach and bacterial quality of drinking water of urban and rural communities in Egypt

Water is necessary to life so when supplied as drinking water to consumers, a satisfactory quality must be maintained. In Egypt, infectious intestinal diseases are the major cause of hospitalization in almost all regions. The purpose of this study was to evaluate the microbiological quality of treated and untreated water samples from urban and rural communities. Thirty-five samples of treated (chlorinated) water from taps, 25 samples of bottled water and 15 samples of hand pump (untreated) water collected from different cities alongside the River Nile during the winter of 2007 were bacteriologically tested for safety as drinking water. This study indicated good quality of tap water and bottled water. The untreated water samples (hand pumps) were, however, slightly contaminated by faecal coliforms, faecal enterococci, Clostridium perfringens, Salmonella and Shigella. Consequently, the consumers in the villages receiving water through hand pumps are often exposed to the risk of water-borne diseases due to inadequate treatment of the raw water. Therefore, there are guidelines necessary to protect groundwater quality. Moreover, PCR-amplified by some functional gene fragments such as dctA, dcuB, frdA, dcuS and dcuR genes of the E. coli was adapted for use as a non-cultivation-based molecular approach for detection of E. coli populations from water samples without the need for pure and identified cultures.     

Chordin knockdown enhances the osteogenic differentiation of human mesenchymal stem cells

Introduction

Bone morphogenetic proteins (BMPs) are critical growth factors in the osteogenic differentiation of progenitor cells during development in embryos and fracture repair in adults. Although recombinant BMPs are in use clinically, their clinical efficiency needs to be improved. The biological activities of BMPs are naturally regulated by extracellular binding proteins. The specific hypotheses tested in this study were as follows: the BMP inhibitor chordin is produced endogenously during the osteogenic differentiation of human mesenchymal stem cells (MSCs); and blockade of the activity of the BMP inhibitor increases the rate of osteogenic differentiation of human MSCs in vitro.

Methods

Human MSCs were derived from bone marrow from an iliac crest aspirate and from patients undergoing hip hemiarthroplasty. The MSCs were induced down the osteogenic pathway using standard osteogenic differentiation media, and expressions of BMP-2 and chordin were determined by gene expression analysis. During osteogenic differentiation, chordin knockdown was induced using RNA interference. Osteogenic differentiation was assessed by measuring the expression of alkaline phosphatase and calcium deposition. The differences in expression of osteogenic makers between groups were compared by analysis of variance, followed by Gabriel post hoc test.

Results

We demonstrate the expression of BMP-2 and chordin in human MSCs during osteogenic differentiation. Knockdown of chordin by RNA interference in vitro resulted in a significant increase in the expression of the osteogenic marker alkaline phosphatase and the deposition of extracellular mineral, in response to osteogenic stimulation.

Conclusion

We conclude that endogenously produced chordin constrains the osteogenic differentiation of human MSCs. The targeting of BMP inhibitors, such as chordin, may provide a novel strategy for enhancing bone regeneration.     

Enhancing antimicrobial properties of dyed and finished cotton fabrics

1,2,3-Benzothiazole-7-thiocarboxylic acid-S-methylester (commercially known as Actigard^® AM-87) was utilized to impart cotton fabric durable antimicrobial properties. Finishing treatment was carried out under a variety of conditions. The latter were included, effect of pH, concentration of antibacterial agents, curing temperature and curing time. The effect of fabric construction, mercerization, and dyeing with different dyestuff were also investigated. The study was also extended to investigate the technical feasibility of combining antimicrobial finishing treatment in question with other finishing treatment generally carried out on cotton fabric, like soft finishing and crease recovery finishing. The treated fabrics were monitored for antimicrobial properties before and after washing. The treated fabrics were also evaluated for the physio-mechanical properties like fabric tensile strength, elongation at break (or bursting strength for knitted fabric), wettability, crease recovery angle, whiteness index and roughness. Results obtained show that, the most appropriate conditions for treatment cotton fabric with Actigard^® are: padding the cotton fabric in aqueous solution containing 6% Actigard^® at pH 5 (adjusted using formic acid) then squeezed to wet pick up of 100%, dried at 80 °C for 5 min then cured at 100 °C for 150 s. The untreated cotton fabric did not show any antimicrobial activity towards Staphylococcus aureus or Escherichia coli. Treatment of cotton fabric with Actigard^® improves its antimicrobial properties towards S. aureus or E. coli. It is also observed that, treatment of cotton fabric with Actigard^® marginally decreases fabric tensile strength, elongation at break, roughness and WI, whereas; both wettability and crease recovery angle remain practically intact. This was observed whether the fabric was pre-mercerized or not.     

Rapamycin induces the TGFβ1/Smad signaling cascade in renal mesangial cells upstream of mTOR

The mTOR kinase inhibitor rapamycin (sirolimus) is a drug with potent immunosuppressive and antiproliferative properties. We found that rapamycin induces the TGFβ/Smad signaling cascade in rat mesangial cells (MC) as depicted by the nuclear translocation of phospho-Smads 2, -3 and Smad-4, respectively. Concomitantly, rapamycin increases the nuclear DNA binding of receptor (R)- and co-Smad proteins to a cognate Smad-binding element (SBE) which in turn causes an increase in profibrotic gene expression as exemplified by the connective tissue growth factor (CTGF) and plasminogen activator inhibitor 1 (PAI-1). Using small interfering (si)RNA we demonstrate that Smad 2/3 activation by rapamycin depends on its endogenous receptor FK binding protein 12 (FKBP12). Mechanistically, Smad induction by rapamycin is initiated by an increase in active TGFβ₁ as shown by ELISA and by the inhibitory effects of a neutralizing TGFβ antibody. Using an activin receptor-like kinase (ALK)-5 inhibitor and by siRNA against the TGFβ type II receptor (TGFβ-RII) we furthermore demonstrate a functional involvement of both types of TGFβ receptors. However, rapamycin did not compete with TGFβ for TGFβ-receptor binding as found in radioligand-binding assay. Besides SB203580, a specific inhibitor of the p38 MAPK, the reactive oxygen species (ROS) scavenger N-acetyl-cysteine (NAC) and a cell-permeable superoxide dismutase (SOD) mimetic strongly abrogated the stimulatory effects of rapamycin on Smad 2 and 3 phosphorylation. Furthermore, the rapid increase in dichlorofluorescein (DCF) formation implies that rapamycin mainly acts through ROS. In conclusion, activation of the profibrotic TGFβ/Smad signaling cascade accompanies the immunosuppressive and antiproliferative actions of rapamycin.     

Phylogeny and phylogeography of critically endangered Gyps species based on nuclear and mitochondrial markers

Populations of Oriental White-backed Vulture (Gyps bengalensis) and Long-billed Vulture (Gyps indicus) dramatically declined by 95–100% on the Indian subcontinent in mid-1990s. The present study was conducted to discover the phylogeny and phylogeography of Gyps species based on nuclear (recombination activating gene, RAG-1) and mitochondrial (cytochrome b, cytb) markers. Gyps species showed monophyly and no geographic partition was observed within the three groups of Gyps species (G. bengalensis, G. indicus and G. fulvus) despite the large sample size available (n = 149). Our study supports the treatment of G. indicus and G. tenuirostris as separate species. In all analyses, the earliest divergence separated G. bengalensis from all other Gyps taxa while a sister relationship was supported between G. fulvus and G. rueppellii, and these two taxa together were sister group to a clade consisting of G. indicus, G. tenuirostris and G. coprotheres. Molecular clock estimates of both nuclear and mitochondrial (RAG-1, cytb) genes indicated a rapid and recent diversification within the Gyps species. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Synthesis and anticancer activity of new [(Indolyl)pyrazolyl]-1,3,4-oxadiazole thioglycosides and acyclic nucleoside analogs

New [(Indolyl)pyrazolyl]-1,3,4-oxadiazole compounds and their derived thioglycosides as well as the corresponding sugar hydrazones were synthesized. The acyclo C-nucleoside analogs of the oxadiazoline base system were also prepared by reaction of acid hydrazides with aldehydo sugars followed by one pot process encompassing acetylation and cyclization of the synthesized hydrazones. The anticancer activity of the newly synthesized compounds was studied against colorectal carcinoma (HCT116), breast adenocarcinoma (MCF7) and prostate cancer (PC3) human tumor cell lines and a number of compounds showed moderate to high activities.     

Amelioration of doxorubicin-induced cardiotoxicity by deferiprone in rats

The therapeutic usefulness of doxorubicin (Dox), an anthracycline antibiotic used as an anticancer agent, is limited by its cardiotoxicity. Dox-induced cardiotoxicity is mainly attributed to accumulation of reactive oxygen species and interaction of Dox with cellular iron metabolism. The present study investigated the effects of the iron chelator deferiprone (Def) against Dox-induced cardiotoxicity in rats. Dox (15?mg/kg) was injected intraperitoneally as a single dose, and Def (10?mg/kg) was administered orally for 10?days. Dox showed cardiotoxicity as evidenced by increased heart rate, elevated ST segment, prolonged QTc interval, and increased T wave amplitude. In addition, Dox enhanced aconitine cardiotoxicity by decreasing its dose, producing ventricular tachycardia. Administration of Def significantly attenuated Dox-induced electrocardiographic changes. Cardiotoxicity of Dox was confirmed biochemically by a significant elevation in serum creatine kinase-MB and lactate dehydrogenase activities as well as by myocardial malondialdehyde and reduced glutathione contents. Moreover, Dox caused a significant decrease in myocardial superoxide dismutase activity. Administration of Def significantly attenuated the biochemical changes. These results suggest that Def might be a potential cardioprotective agent against Dox-induced cardiotoxicity.     

Molecular characterization of the alpha subunit of multicomponent phenol hydroxylase from 4-chlorophenol-degrading Pseudomonas sp. strain PT3

Multicomponent phenol hydroxylases (mPHs) are diiron enzymes that use molecular oxygen to hydroxylate a variety of phenolic compounds. The DNA sequence of the alpha subunit (large subunit) of mPH from 4-chlorophenol (4-CP)-degrading bacterial strain PT3 was determined. Strain PT3 was isolated from oil-contaminated soil samples adjacent to automobile workshops and oil stations after enrichment and establishment of a chlorophenol-degrading consortium. Strain PT3 was identified as a member of Pseudomonas sp. based on sequence analysis of the 16S rRNA gene fragment. The 4-CP catabolic pathway by strain PT3 was tentatively proposed to proceed via a meta-cleavage pathway after hydroxylation to the corresponding chlorocatechol. This hypothesis was supported by polymerase chain reaction (PCR) detection of the LmPH encoding sequence and UV/VIS spectrophotometric analysis of the culture filtrate showing accumulation of 5-chloro-2-hydroxymuconic semialdehyde (5-CHMS) with λ_max 380. The detection of catabolic genes involved in 4-CP degradation by PCR showed the presence of both mPH and catechol 2,3-dioxygenase (C23DO). Nucleotide sequence analysis of the alpha subunit of mPH from strain PT3 revealed specific phylogenetic grouping to known mPH. The metal coordination encoding regions from strain PT3 were found to be conserved with those from the homologous dinuclear oxo-iron bacterial monooxygenases. Two DE(D)XRH motifs was detected in LmPH of strain PT3 within an approximate 100 amino acid interval, a typical arrangement characteristic of most known PHs.     

CD spectrum of bacteriorhodopsin: Best evidence against exciton model

We summarize the predictions of the exciton model that was originally proposed to explain the observed biphasic band shape of its CD spectrum in the visible region of bacteriorhodopsin (bR). It is shown that to reconcile these predictions with the observed results on the linear dichroism, the retinal isomerization time and, the retinal-retinal distance, the biphasic nature of the observed CD spectrum of bR becomes itself an evidence against the exciton model because of the uncertainty principle.

Reduced bR (RbR), which retains its hexagonal structure, shows a monophasic CD spectrum with relatively small rotational strength as compared to bR. This is shown to disagree with predictions made by the exciton model. The results could best be explained in terms of retinal-protein heterogeneity leading to two or more types of bR in which their retinals suffer opposite sense of intramolecular rotational distortion along their retinal long axis. Such a retinal-protein heterogeneity disappears in reduced bR which is known to have a planar (nondistorted) retinal conjugated system, resulting in a monophasic CD with reduced rotational strength, as observed.