Activity,tissue distribution and site-directed mutagenesis of a human peptide methionine sulfoxide reductase of type B: hCBS1

Immunochemical and functional evidence showing the existence in the inner membrane and matrix fraction of mammalian mitochondria of serine/threonine phosphatases acting on cAMP-dependent phosphoproteins is presented. Mg(2+)-dependent Ca(2+)-inhibitable PP2C phosphatase, associated to the inner membrane, dephosphorylates the 18 kDa (NDUFS4 gene) of complex I.     

Intraluteal administration of a nitric oxide synthase blocker stimulates progesterone and oxytocin secretion and prolongs the life span of the bovine corpus luteum

To test the role of nitric oxide (NO) in secretory functions of bovine corpora lutea (CL), two groups of four Holstein heifers each were treated as follows: Group 1, Nomega-Nitro-L-Arginine Methyl Ester (L-NAME), an inhibitor of nitric oxide synthase (NOS), on Day 11 or 12 of the cycle and Group 2, L-NAME on Days 17 and 18 of the cycle. All treatments were administered by an intraluteal microdialysis system (MDS). Drugs were infused for 4-hr periods on the designated days, and the treatment periods were preceded and followed by 4-hr control periods. Perfusate and jugular blood samples were collected at half-hour intervals. Perfusate samples were analyzed for progesterone (P4), oxytocin (OT), prostaglandin F2alpha (PGF2alpha), and leukotriene C4 (LTC4); jugular plasma samples were analyzed for P4, OT, and LH. Perfusion of L-NAME on Day 11 or 12 consistently increased P4 concentration in the perfusate, but had no effect on the life span of the CL. Perfusion of L-NAME on Days 17-18 also elevated P4 levels in the perfusate, and in addition, maintained P4 levels in the plasma of three of the four treated animals through Day 25 of the cycle. L-NAME perfusion also increased OT release concomitant with P4 into the perfusate at both the mid- and late-luteal phase treatments. For the most part, concentrations of LH, OT, and P4 in the jugular plasma samples collected during the perfusions were unaffected by treatments. L-NAME perfusion caused small, but significant (P < 0.05) increases in perfusate PGF2alpha and LTC4 at Days 17 and 18 and in LTC4 on Day 11 or 12. These data indicate that NO plays a direct luteolytic role in regression of the bovine CL.     

Exogeneous substances affecting development of in vitro-derived bovine embryos before and after embryonic genome activation

Three experiments were conducted to evaluate how exogenous substances [fetal bovine serum (FBS), arachidonic acid (AA), glutathione (GSH), platelet-derived growth factor (PDGF), transforming growth factor-beta (TGF), fibroblast growth factor (FGF), insulin, transferrin and selenium (ITS)] affect preimplantation bovine embryo development. Cumulus-oocyte complexes (COC) were matured and fertilized in vitro, and their development was monitored up to 192 h post insemination in a two-step culture system. In Experiment 1, inseminated oocytes were cultured in modified bovine embryo culture medium (mBECM) supplemented with FBS or BSA for up to 60 h post insemination, and the resultant 8-cell embryos were then cultured singly in mBECM supplemented with AA+GSH+PDGF+TGF. More (P<0.005) blastocysts were derived from 8-cell embryos produced in media containing FBS than BSA. In Experiment 2, the 8-cell embryos produced in mBECM supplemented with FBS were cultured singly in mBECM as follows: 1) no supplementation; 2) AA and GSH or 3) AA, GSH, PDGF and TGF. Compared with no supplementation, a significant (P<0.05) increase in the proportion of 16-cell embryos and morulae was obtained after the addition of either AA+GSH or AA+GSH+PDGF+TGF. In Experiment 3, oocytes were cultured singly in mBECM as follows: 1) no supplementation; 2) AA+GSH+PDGF+TGF; 3) AA+GSH+PDGF+TGF and FGF; 4) AA+GSH+PDGF+TGF and ITS; 5) AA+GSH+PDGF+TGF, FGF and ITS or 6) FBS. Eight-cell embryos grown in each system were subsequently cultured singly in mBECM with AA+GSH+PDGF+TGF. More (P<0.05) 16-cell embryos were obtained in medium supplemented with either AA+GSH+PDGF+TGF and ITS or FBS than in unsupplemented medium. Fewer (P<0.05) oocytes developed to the 8-cell stage with the addition of AA+GSH+PDGF+TGF and FGF than without. In conclusion, embryo development to the blastocyst stage is regulated by exogenous AA, GSH, PDGF, FGF and ITS in a stage-specific manner.     

Crystallographic and chemical signatures in coral skeletal aragonite

Coral Reefs - Corals nucleate and grow aragonite crystals, organizing them into intricate skeletal structures that ultimately build the world’s coral reefs. Crystallography and chemistry have...     

A prospective study of decline in fat free mass and skeletal muscle strength in chronic obstructive pulmonary disease

Background

Skeletal muscle depletion is an important complication of chronic obstructive pulmonary disease (COPD) but little prospective data exists about the rate at which it occurs and the factors that promote its development. We therefore prospectively investigated the impact of disease severity, exacerbation frequency and treatment with corticosteroids on change in body composition and maximum isometric quadriceps strength (QMVC) over one year.

Methods

64 patients with stable COPD (FEV₁ mean (SD) 35.8(18.4) %predicted) were recruited from clinic and studied on two occasions one year apart. Fat free mass was determined using bioelectrical impedance analysis and a disease specific regression equation.

Results

QMVC fell from 34.8(1.5) kg to 33.3(1.5) kg (p = 0.04). The decline in quadriceps strength was greatest in those with the highest strength at baseline (R -0.28 p = 0.02) and was not correlated with lung function, exacerbation frequency or steroid treatment. Decline in fat free mass was similarly higher in those with largest FFM at baseline (R = -0.31 p = 0.01) but was more strongly correlated with greater gas trapping (R = -0.4 p = 0.001). Patients with frequent exacerbations (>1 per year) (n = 36) experienced a greater decline in fat free mass compared to infrequent exacerbators (n = 28) -1.3(3.7)kg vs. +1.2(3.1)kg (p = 0.005), as did patients on maintenance oral steroids (n = 8) -2.8(3.3) kg vs. +0.2(3.5) kg (p = 0.024) whereas in those who stopped smoking (n = 7) fat free mass increased; +2.7(3.1) kg vs. -0.51(3.5) kg (p = 0.026).

Conclusion

Decline in fat free mass in COPD is associated with worse lung function, continued cigarette consumption and frequent exacerbations. Factors predicting progression of quadriceps weakness could not be identified from the present cohort.     

Microbial community related to volatile organic compound (VOC) emission in household biowaste

Malodorous emissions and potentially pathogenic microorganisms which develop during domestic organic waste collection are not only a nuisance but may also pose health risks. The aim of the present study was to determine whether the presence of specific microorganisms in biowastes is directly related to the composition of the emitted volatile organic compounds (VOCs). The succession of microbial communities during 16 days of storage in organic waste collection bins was studied by denaturing gradient gel electrophoresis (DGGE) of amplified 16S ribosomal DNA in parallel with a classical cultivation and isolation approach. Approximately 60 different bacterial species and 20 different fungal species were isolated. Additionally, some bacterial species were identified through sequencing of excised DGGE bands. Proton transfer reaction mass spectrometry (PTR-MS) was used to detect VOCs over the sampling periods, and co-inertia analyses of VOC concentrations with DGGE band intensities were conducted. Positive correlations, indicating production of the respective VOC or enhancement of microbial growth, and negative correlations, indicating the use of, or microbial inhibition by the respective compound, were found for the different VOCs. Measurement of the VOC emission pattern from a pure culture of Lactococcus lactis confirmed the positive correlations for the protonated masses 89 (tentatively identified as butyric acid), 63 (tentatively identified as dimethylsulfide), 69 (likely isoprene) and 73 (likely butanone).     

Practical approaches to plant volatile analysis

Plants emit volatile organic compounds (VOCs) that play important roles in their interaction with the environment and have a major impact on atmospheric chemistry. The development of static and dynamic techniques for headspace collection of volatiles in combination with gas chromatography-mass spectrometry analysis has significantly improved our understanding of the biosynthesis and ecology of plant VOCs. Advances in automated analysis of VOCs have allowed the monitoring of fast changes in VOC emissions and facilitated in vivo studies of VOC biosynthesis. This review presents an overview of methods for the analysis of plant VOCs, including their advantages and disadvantages, with a focus on the latest technical developments. It provides guidance on how to select appropriate instrumentation and protocols for biochemical, physiological and ecologically relevant applications. These include headspace analyses of plant VOCs emitted by the whole organism, organs or enzymes as well as advanced on-line analysis methods for simultaneous measurements of VOC emissions with other physiological parameters.     

Inhibitors of HIV-1 attachment. Part 8: The effect of C7-heteroaryl substitution on the potency,and in vitro and in vivo profiles of indole-based inhibitors

As part of the SAR profiling of the indole-oxoacetic piperazinyl benzamide class of HIV-1 attachment inhibitors, substitution at the C7 position of the lead 4-fluoroindole 2 with various 5- and 6-membered heteroaryl moieties was explored. Highly potent (picomolar) inhibitors of pseudotyped HIV-1 in a primary, cell-based assay were identified and select examples were shown to possess nanomolar inhibitory activity against M- and T-tropic viruses in cell culture. These C7-heteroaryl-indole analogs maintained the ligand efficiency (LE) of 2 and were also lipophilic efficient as measured by LLE and LELP. Pharmacokinetic studies of this class of inhibitor in rats showed that several possessed substantially improved IV clearance and half-lives compared to 2. Oral exposure in the rat correlated with membrane permeability as measured in a Caco-2 assay where the highly permeable 1,2,4-oxadiazole analog 13 exhibited the highest exposure.