Modulation of myosin phosphatase targeting subunit and protein phosphatase 1 in the heart

Myosin light chain 2 (LC2) phosphorylation is of both physiological and pathological importance to myocardial function. The phosphatase that directly dephosphorylates LC2 is a type 1 protein phosphatase (PP1) that contains a catalytic subunit that complexes with a myosin-binding phosphatase targeting subunit (MYPT). The goal of the present study was to examine the role of MYPT in the regulation of PP1 in ventricular myocytes. In the first part of the study, regional distribution of MYPT expression and phosphorylation were determined in unstimulated hearts. The pattern of MYPT phosphorylation was inversely related to the LC2 phosphorylation spatial gradient as described by Epstein and colleagues (Davis JS, Hassanzadeh S, Winitsky S, Lin H, Satorius C, Vemuri R, Aletras AH, Wen H, and Epstein ND. Cell 107: 631-641, 2001). In the second part of the study, adult rat isolated ventricular myocytes were exposed to an alpha-adrenergic receptor agonist, and properties of MYPT, PP1, and LC2 were studied. We found MYPT associates with cardiac myofilaments, and this association increases upon alpha-adrenergic receptor stimulation. Activation of alpha-adrenergic receptors also led to a decrease in the PP1-myofilament association. Furthermore, alpha-adrenergic receptor stimulation results in phosphorylation of MYPT and LC2 and an increase in myocyte Ca(2+) sensitivity of tension that all depend on Rho kinase activation. These data support the hypothesis that alpha-adrenergic receptor activation works through Rho kinase to phosphorylate MYPT, and phosphorylated MYPT dissociates from PP1 so that PP1 is no longer physically associated with LC2. Hence, we propose a pathway for the dynamic modulation of LC2 phosphorylation through receptor-dependent phosphorylation of MYPT, and a spatial gradient of LC2 phosphorylation under basal conditions that occurs due to varied levels of phosphorylation of MYPT in ventricles.     

Effect of different strains of yeast on stereocontrolled reduction of 5-acetylisoxazolines

The stereocontrolled reduction of 3-aryl-5-acetylisoxazolines (1) to the corresponding alcohols (2 and 3) in the presence of four different yeast strains, recognized as Baker's yeast (commercial), Candida krusei (ATCC 14243), Pichia farinosa (NRRL Y110) and Sacchromyces sp. (soil isolate) have been attempted. The C. krusei was found to be diastereoselective for the (R)-1 while the Sacchromyces sp. led to complete reduction to yield the RS- and SS-alcohol in 1:1 ratio at 10 g/L scale.     

Effect of periphyton on growth performance of grey mullet, Mugil cephalus (Linn.), in inland saline groundwater ponds

The present study attempts to assess the potential of artificial substrates to enhance fish production in inland saline groundwater ponds through periphyton production. Grey mullet, Mugil cephalus, was cultured for 100 days in ponds with substrate (treatment ponds) and without substrate (control ponds). To enhance the surface area, bamboo poles were used as substrate. The periphyton population, pigment concentration and hydrobiological characteristics of pond water were monitored. The studies revealed little difference in most of the water quality parameters observed in the two treatments. However, turbidity (27.0 ± 0.1–35.0 ± 0.1 Nephalo Turbidity Unit (NTU)), chlorophyll ‘a’ (6.6 ± 0.6–7.6 ± 0.6 μg L^?1), plankton population (phytoplankton 8.4 × 10³–9.4 ×10³ numbers L^?1; zooplankton 4.0 × 10³–5.1 × 10³ numbers L^?1) and NH₄–N (2.0 ± 0.2–2.3 ± 0.1 mg L^?1) were high in the treatment with no additional substrate; however, in the treatment with substrate the total Kjeldahl nitrogen (9.8 ± 0.8–10.8 ± 0.7 mg L^?1) and o‐PO₄ (0.1 ± 0.01–0.1 mg L^?1) remained significantly (P < 0.05) higher. Highest periphyton biomass in terms of dry matter (DM) (0.8 ± 0.01–1.4 ±0.01 mg cm^?2), ash free DM (0.4 ± 0.0–0.6 ± 0.01 mg cm^?2), chlorophyll ‘a’ (3.1 ± 0.2–8.1 ± 0.8 μg cm^?2) and pheophytin ‘a’ (1.9 ± 0.4–3.9 ± 0.5 μg cm^?2) was observed at 50 cm depth in ponds provided with additional substrate. Fifteen plankton genera showing periphytic affinity colonized the bamboo substrates. Fish growth (mean fish weight 524.3 ± 8.7 g and SGR 2.5 ± 0.1) was significantly (P < 0.05) higher in ponds provided with additional substrate compared with control ponds (387.2 ± 6.0). Length–weight relationship (LWR) (W = cLⁿ) also showed that the exponential value (‘n’) of length was high in substrate‐supported ponds (n = 2.36) in comparison with controls (n = 1.09). These studies suggest that a periphyton‐supported aquaculture system can be used successfully for the culture of herbivorous brackishwater fish species like M. cephalus in inland saline groundwaters and thus could contribute to the development of sound and sustainable aquaculture technology.     

The structure and stereochemistry of phlogantholide-A,a diterpene from Phlogacanthus thyrsiflorus

The structure and stereochemistry of phlogantholide-A, a new diterpene lactone isolated from the leaves of Phlogacanthus thyrsiflorus has been determined as 2β,15,18-trihydroxy-ent-labd-8(17),13-dien-16-oic lactone by chemical and spectroscopic means.     

Oral rehydration formula containing alanine and glucose for treatment of diarrhoea: a controlled trial.

OBJECTIVE--To determine whether adding L-alanine to the glucose based oral rehydration solution recommended by the World Health Organisation would improve its efficacy in treating acute diarrhoea. DESIGN--Randomised double blind controlled trial of oral rehydration solution containing L-alanine and glucose. SETTING--Inpatient service of a hospital treating diarrhoea. PATIENTS--97 Male patients aged 6-59 years admitted to the hospital with acute and severe dehydration due to diarrhoea associated with Vibrio cholerae or enterotoxigenic Escherichia coli. Forty nine received the standard glucose based oral rehydration solution (control group) and 48 this solution with alanine added (study group). INTERVENTIONS--All of the patients received rapid intravenous acetate solution for the initial four hours after admission, which fully corrected the signs of dehydration. They were then admitted to the study and randomised. Immediately after the intravenous treatment oral rehydration treatment was started. All of the patients received oral tetracycline for 48 hours, starting 24 hours after start of the study. If signs of dehydration reappeared during oral treatment patients were given rapid intravenous acetate solution until they were fully corrected and then continued to take the assigned oral rehydration solution. END POINT--Passage of the last watery stool. MEASUREMENTS and MAIN RESULTS--The median stool output/kg body weight during the initial 24 hours of oral rehydration treatment and until diarrhoea stopped was reduced in the study group compared with the control group from 309 ml to 196 ml and from 393 ml to 236 ml respectively. Intake of oral rehydration solution and intravenous acetate solution was reduced from 455 ml to 308 ml and from 616 ml to 425 ml respectively. Two patients in the study group compared with 18 patients in the control group required unscheduled rapid intravenous acetate solution to correct signs of dehydration during oral rehydration treatment. CONCLUSION--Oral rehydration solution containing L-alanine was considerably better than standard oral rehydration solution at reducing the severity of symptoms and the need for fluid of male patients with diarrhoea associated with V cholerae and enterotoxigenic E coli.     

Experiences of a Community-Based Lymphedema Management Program for Lymphatic Filariasis in Odisha State,India: An Analysis of Focus Group Discussions with Patients,Families, Community Members and Program Volunteers

Background

Globally 68 million people are infected with lymphatic filariasis (LF), 17 million of whom have lymphedema. This study explores the effects of a lymphedema management program in Odisha State, India on morbidity and psychosocial effects associated with lymphedema.

Methodology/Principal Findings

Focus groups were held with patients (eight groups, separated by gender), their family members (eight groups), community members (four groups) and program volunteers (four groups) who had participated in a lymphedema management program for the past three years. Significant social, physical, and economic difficulties were described by patients and family members, including marriageability, social stigma, and lost workdays. However, the positive impact of the lymphedema management program was also emphasized, and many family and community members indicated that community members were accepting of patients and had some improved understanding of the etiology of the disease. Program volunteers and community members stressed the role that the program had played in educating people, though interestingly, local explanations and treatments appear to coexist with knowledge of biomedical treatments and the mosquito vector.

Conclusions/Significance

Local and biomedical understandings of disease can co-exist and do not preclude individuals from participating in biomedical interventions, specifically lymphedema management for those with lymphatic filariasis. There is a continued need for gender-specific psychosocial support groups to address issues particular to men and women as well as a continued need for improved economic opportunities for LF-affected patients. There is an urgent need to scale up LF-related morbidity management programs to reduce the suffering of people affected by LF.     

Characterization of the folding and unfolding reactions of single-chain monellin: evidence for multiple intermediates and competing pathways

The mechanisms of folding and unfolding of the small plant protein monellin have been delineated in detail. For this study, a single-chain variant of the natively two-chain monellin, MNEI, was used, in which the C terminus of chain B was connected to the N terminus of chain A by a Gly-Phe linker. Equilibrium guanidine hydrochloride (GdnHCl)-induced unfolding experiments failed to detect any partially folded intermediate that is stable enough to be populated at equilibrium to a significant extent. Kinetic experiments in which the refolding of GdnHCl-unfolded protein was monitored by measurement of the change in the intrinsic tryptophan fluorescence of the protein indicated the accumulation of three transient partially structured folding intermediates. The fluorescence change occurred in three kinetic phases: very fast, fast, and slow. It appears that the fast and slow changes in fluorescence occur on competing folding pathways originating from one unfolded form and that the very fast change in fluorescence occurs on a third parallel pathway originating from a second unfolded form of the protein. Kinetic experiments in which the refolding of alkali-unfolded protein was monitored by the change in the fluorescence of the hydrophobic dye 8-anilino-1-naphthalenesulfonic acid (ANS), consequent to the dye binding to the refolding protein, as well as by the change in intrinsic tryptophan fluorescence, not only confirmed the presence of the three kinetic intermediates but also indicated the accumulation of one or more early intermediates at a few milliseconds of refolding. These experiments also exposed a very slow kinetic phase of refolding, which was silent to any change in the intrinsic tryptophan fluorescence of the protein. Hence, the spectroscopic studies indicated that refolding of single-chain monellin occurs in five distinct kinetic phases. Double-jump, interrupted-folding experiments, in which the accumulation of folding intermediates and native protein during the folding process could be determined quantitatively by an unfolding assay, indicated that the fast phase of fluorescence change corresponds to the accumulation of two intermediates of differing stabilities on competing folding pathways. They also indicated that the very slow kinetic phase of refolding, identified by ANS binding, corresponds to the formation of native protein. Kinetic experiments in which the unfolding of native protein in GdnHCl was monitored by the change in intrinsic tryptophan fluorescence indicated that this change occurs in two kinetic phases. Double-jump, interrupted-unfolding experiments, in which the accumulation of unfolding intermediates and native protein during the unfolding process could be determined quantitatively by a refolding assay, indicated that the fast unfolding phase corresponds to the formation of fully unfolded protein via one unfolding pathway and that the slow unfolding phase corresponds to a separate unfolding pathway populated by partially unfolded intermediates. It is shown that the unfolded form produced by the fast unfolding pathway is the one which gives rise to the very fast folding pathway and that the unfolded form produced by the slower unfolding pathway is the one which gives rise to the slow and fast folding pathways.     

The Ba813 chromosomal DNA sequence effectively traces the whole Bacillus anthracis community

Plasmid genes that are responsible for virulence of Bacillus anthracis are important targets for the DNA-based detection of anthrax. We evaluated the distribution of the Ba813 chromosomal DNA sequence (Ba813) within closely related Bacillus species. Ba813 was systematically identified from 47 strains or isolates of B. anthracis tested, thus indicating its reliability as a tracer for that species. From the 60 strains of closely related Bacillus spp. examined, three bona fide B. cereus and one bona fide B. thuringiensis were found to harbour Ba813. This marker was also detected in Bacillus sp. isolates that were present at high levels in soil samples collected in a place where an anthrax outbreak had occurred. The significance and the possible function of the Ba813 locus is discussed.     

Unraveling the effects of management regime and plant species on soil organic carbon and microbial phospholipid fatty acid profiles in grassland soils

In a field experiment we have examined the effect of long-term grassland management regimes (viz., intensive versus extensive) and dominant plant species (viz., Arrhenatherum elatius, Holcus lanatus and Dactylis glomerata) on soil organic carbon (SOC) build up, soil microbial communities using biomarker phospholipid fatty acids (PLFA), and the relationship between SOC and PLFAs of major groups of microorganisms (viz., bacteria, fungi, and actinomycetes). The results have revealed that changes in SOC were not significantly affected by the intensity of management or by the plant species composition or by their interaction. The amount of PLFA of each microbial group was affected weakly by management regime and plant species, but the canonical variance analysis (CVA), based on individual PLFA values, demonstrated significant (P<0.05) effects of management regime and plant species on the composition of microbial community. Positive and significant (P<0.01) relationships were observed between PLFA of bacteria (R2=0.47), fungi (R2=0.33), actinomycetes (R2=0.71) and total microbial PLFA (R2=0.53) and SOC content.