Cloning and expression analysis of two distinct HIF-alpha isoforms – gcHIF-1alpha and gcHIF-4alpha – from the hypoxia-tolerant grass carp,Ctenopharyngodon idellus

Background  

Hypoxia-inducible factors (HIFs) are involved in adaptive and survival responses to hypoxic stress in mammals. In fish, very little is known about the functions of HIFs.     

Preliminary investigations on the synthesis and antitumor activity of 3(2H)-furanones

Two triaryl-3(2H)-furanones were synthesized and their antitumor activity was evaluated. These compounds inhibited the proliferation of DLA cell line in vitro. In vivo studies also showed that these compounds were active against tumor cell proliferation.     

Does obstructive sleep apnea correlate with Epworth Sleepiness Scale in an Indian population?

Sleep and Biological Rhythms - Various demographic and clinical predictors attributing to the severity of obstructive sleep apnea (OSA) in Indian subjects have not been extensively studied....     

Increased sulfate uptake by E. coli overexpressing the SLC26-related SulP protein Rv1739c from Mycobacterium tuberculosis

Growth and virulence of mycobacteria requires sulfur uptake. The Mycobacterium tuberculosis genome contains, in addition to the ABC sulfate permease cysTWA, three SLC26-related SulP genes of unknown function. We report that induction of Rv1739c expression in E. coli increased bacterial uptake of sulfate, but not Cl(-), formate, or oxalate. Uptake was time-dependent, maximal at pH 6.0, and exhibited a K(1/2) for sulfate of 4.0 muM. Na(+)-independent sulfate uptake was not reduced by bicarbonate, nitrate, or phosphate, but was inhibited by sulfite, selenate, thiosulfate, N-ethylmaleimide and carbonyl cyanide 3-chloro-phenylhydrazone. Sulfate uptake was also increased by overexpression of the Rv1739c transmembrane domain, but not of the cytoplasmic C-terminal STAS domain. Mutation to serine of the three cysteine residues of Rv1739c did not affect magnitude, pH-dependence, or pharmacology of sulfate uptake. Expression of Rv1739c in a M. bovis BCG strain lacking the ABC sulfate permease subunit CysA could not complement sulfate auxotrophy. Moreover, inducible expression of Rv1739c in an E. coli strain lacking CysA did not increase sulfate uptake by intact cells. Our data show that facilitation of bacterial sulfate uptake by Rv1739c requires CysA and its associated sulfate permease activity, and suggest that Rv1739c may be a CysTWA-dependent sulfate transporter.     

Non-invasive measurements of exhaled NO and CO associated with methacholine responses in mice

Background

Nitric oxide (NO) and carbon monoxide (CO) in exhaled breath are considered obtainable biomarkers of physiologic mechanisms. Therefore, obtaining their measures simply, non-invasively, and repeatedly, is of interest, and was the purpose of the current study.

Methods

Expired NO (E_NO) and CO (E_CO) were measured non-invasively using a gas micro-analyzer on several strains of mice (C57Bl6, IL-10^-/-, A/J, MKK3^-/-, JNK1^-/-, NOS-2^-/- and NOS-3^-/-) with and without allergic airway inflammation (AI) induced by ovalbumin systemic sensitization and aerosol challenge, compared using independent-sample t-tests between groups, and repeated measures analysis of variance (ANOVA) within groups over time of inflammation induction. E_NO and E_CO were also measured in C57Bl6 and IL-10-/- mice, ages 8–58 weeks old, the relationship of which was determined by regression analysis. S-methionyl-L-thiocitrulline (SMTC), and tin protoporphyrin (SnPP) were used to inhibit neuronal/constitutive NOS-1 and heme-oxygenase, respectively, and alter NO and CO production, respectively, as assessed by paired t-tests. Methacholine-associated airway responses (AR) were measured by the enhanced pause method, with comparisons by repeated measures ANOVA and post-hoc testing.

Results

E_NO was significantly elevated in naïve IL-10^-/- (9–14 ppb) and NOS-2^-/- (16 ppb) mice as compared to others (average: 5–8 ppb), whereas E_CO was significantly higher in naïve A/J, NOS-3^-/- (3–4 ppm), and MKK3^-/- (4–5 ppm) mice, as compared to others (average: 2.5 ppm). As compared to C57Bl6 mice, AR of IL-10^-/-, JNK1^-/-, NOS-2^-/-, and NOS-3^-/- mice were decreased, whereas they were greater for A/J and MKK3^-/- mice. SMTC significantly decreased E_NO by ~30%, but did not change AR in NOS-2^-/- mice. SnPP reduced E_CO in C57Bl6 and IL-10^-/- mice, and increased AR in NOS-2^-/- mice. E_NO decreased as a function of age in IL-10^-/- mice, remaining unchanged in C57Bl6 mice.

Conclusion

These results are consistent with the ideas that: 1) E_NO is associated with mouse strain and knockout differences in NO production and AR, 2) alterations of E_NO and E_CO can be measured non-invasively with induction of allergic AI or inhibition of key gas-producing enzymes, and 3) alterations in AR may be dependent on the relative balance of NO and CO in the airway.     

Biomarkers in osteoarthritis

Biomarkers aid the study of osteoarthritis (OA) in a number of different ways. In this article we summarise briefly their multiple uses and reflect on how the study reported in a previous edition of Arthritis Research & Therapy should promote further investigation of cartilage oligomeric matrix protein (COMP). COMP is foremost among hitherto investigated biomarkers and is most consistently shown to predict knee OA progression. Precisely what role it plays in OA pathogenesis remains unclear and elucidating this may be key to defining, and then targeting, the cellular pathways involved in OA.     

DETECTING DESERTIFICATION PROCESSES USING TM AND ETM+ DATA, NORTH OF ISFAHAN, IRAN

 Aims Desertification results in ecological and biological diminution of the earth, and can happen naturally or cause by anthropogenic activities. This process especially affects arid and semi-arid regions, such as the Isfahan region, where the spread of desertification is reaching critical proportions. The aim of this study is to use remotely sensed data to review the trend of desertification in the northern of Isfahan, Iran. Methods Multi-temporal images were employed to evaluate the trend of desertification, specifically the TM and ETM+ data of September, 1990 and September, 2001. Geometric and radiometric corrections were applied to each image prior to image processing and supervised classification, and vegetation indices were applied to produce a land use map of each image in nine classes. The land use classification s in the two map images were compared and changes between land use classes were detected over the 11 year period using a fuzzy and post-classification technique. Important findings The maps and their comparison with false color composite images showed the differences efficiently. With the fuzzy and post-classification method the land use changes were sited on the map. Fuzzy confirmed 53% changed area and 47% unchanged areas in the study region. The results verify the desertification expansion in the study areas. Because of poor land management, agricultural lands converted to desert and abandoned areas, and some marginal pasture lands had to be changed to agricultural land which are desertification spreading according to United Nations Conference on Desertification (UNCOD). Also farmland and pastures have been converted to urban and industrial areas, and the rangelands have been spoiled due to opencast mine excavations. With the mine margins eroding as well as their debris accumulating on the pasture lands, desertification has become worse. Three areas of less-elevated mountains have remained unchanged. This study confirmed that the anthropogenic activities accelerated the desertification process and severely endangered the remaining areas.     

Frequent occurrence of recognition Site-like sequences in the restriction endonucleases

Background  

There are two different theories about the development of the genetic code. Woese suggested that it was developed in connection with the amino acid repertoire, while Crick argued that any connection between codons and amino acids is only the result of an "accident". This question is fundamental to understand the nature of specific protein-nucleic acid interactions.     

Role of phenolic O-H and methylene hydrogen on the free radical reactions and antioxidant activity of curcumin

To understand the relative importance of phenolic O-H and the CH-H hydrogen on the antioxidant activity and the free radical reactions of Curcumin, (1,7-bis[4-hydroxy-3-methoxyphenyl]-1,6-heptadiene-3,5-dione), biochemical, physicochemical, and density functional theory (DFT) studies were carried out with curcumin and dimethoxy curcumin (1,7-bis[3, 4-dimethoxy phenyl]-1,6-heptadiene-3,5-dione). The antioxidant activity of these compounds was tested by following radiation-induced lipid peroxidation in rat liver microsomes, and the results suggested that at equal concentration, the efficiency to inhibit lipid peroxidation is changed from 82% with curcumin to 24% with dimethoxy curcumin. Kinetics of reaction of (2,2'-diphenyl-1-picrylhydrazyl) DPPH, a stable hydrogen abstracting free radical was tested with these two compounds using stopped-flow spectrometer and steady state spectrophotometer. The bimolecular rate constant for curcumin was found to be approximately 1800 times greater than that for the dimethoxy derivative. Cyclic voltammetry studies of these two systems indicated two closely lying oxidation peaks at 0.84 and 1.0 V vs. SCE for curcumin, while only one peak at 1.0 V vs. SCE was observed for dimethoxy curcumin. Pulse radiolysis induced one-electron oxidation of curcumin and dimethoxy curcumin was studied at neutral pH using (*)N(3) radicals. This reaction with curcumin produced phenoxyl radicals absorbing at 500 nm, while in the case of dimethoxy curcumin a very weak signal in the UV region was observed. These results suggest that, although the energetics to remove hydrogen from both phenolic OH and the CH(2) group of the beta-diketo structure are very close, the phenolic OH is essential for both antioxidant activity and free radical kinetics. This is further confirmed by DFT calculations where it is shown that the -OH hydrogen is more labile for abstraction compared to the -CH(2) hydrogen in curcumin. Based on various experimental and theoretical results it is definitely concluded that the phenolic OH plays a major role in the activity of curcumin.