The function of hemocyanin in respiration of the blue crab Callinectes sapidus.

Blood PO2 in the blue crab Callinectes sapidus, a very active species of tropical origin, is lower at 22 degrees C than that of larger crabs in colder waters. These low oxygen levels permit its hemocyanin to be highly oxygenated at the gill, and to deliver almost half of its oxygen to the tissues in resting animals. Sustained muscular activity results in conspicuous decreases in blood PO2, pH and hemocyanin oxygenation. Although the venous reserve is fully utilized, hemocyanin oxygenation at the gill decreases so much that there is no change in its total quantitative function. The large Bohr shift becomes functional during activity, but its quantitative importance is not clear.     

Delayed blockade of the kinin B1 receptor reduces renal inflammation and fibrosis in obstructive nephropathy

Renal fibrosis is the common histological feature of advanced glomerular and tubulointerstitial disease leading to end-stage renal disease (ESRD). However, specific antifibrotic therapies to slow down the evolution to ESRD are still absent. Because persistent inflammation is a key event in the development of fibrosis, we hypothesized that the proinflammatory kinin B1 receptor (B1R) could be such a new target. Here we show that, in the unilateral ureteral obstruction model of renal fibrosis, the B1R is overexpressed and that delayed treatment with an orally active nonpeptide B1R antagonist blocks macrophage infiltration, leading to a reversal of the level of renal fibrosis. In vivo bone marrow transplantation studies as well as in vitro studies on renal cells show that part of this antifibrotic mechanism of B1R blockade involves a direct effect on resident renal cells by inhibiting chemokine CCL2 and CCL7 expression. These findings suggest that blocking the B1R is a promising antifibrotic therapy.     

Beverage specific alcohol intake in a population-based study: Evidence for a positive association between pulmonary function and wine intake

Background  

Lung function is a strong predictor of cardiovascular and all-cause mortality. Previous studies suggest that alcohol exposure may be linked to impaired pulmonary function through oxidant-antioxidant mechanisms. Alcohol may be an important source of oxidants; however, wine contains several antioxidants. In this study we analyzed the relation of beverage specific alcohol intake with forced expiratory volume in one second (FEV₁) and forced vital capacity (FVC) in a random sample of 1555 residents of Western New York, USA.     

Reversal of Ethionine-Induced Inhibition of Elongation of Avena Coleoptiles by Purines, Adenosine, and Glutamic Acid

Ethionine-induced inhibition of elongation of Avena coleoptile segments has been measured in water and in indol-3yl-acetic acid. In the presence of 10 mM L-ethionine the inhibition amounts to about 70 %. It has been shown previously that the addition of adenosine triphosphate effectively counteracts this inhibition; optimal ATP concentrations are between 0.25 and 0.5 mM. Adenine, adenine sulfate, adenosine, guanine, S-adenosylmethionine, and glutamic acid have now been shown to act similarly to ATP in reversing the ethionine-induced inhibition of elongation.     

Isolation of N5N10 -Methylene Tetrahydrofolate Reductase From Bovine Brain

N⁵,N¹⁰ -methylene tetrahydrofolate reductase has been purified 100-fold from bovine brain. The initial fractionation with protamine sulfate and ammonium sulfate was followed by chromatography on DEAE-polyacrylamide gel (Bio Gel DM-30) and Sephadex G-200 as well as the selective adsorption and elution of the enzyme on calcium phosphate gel. The purified enzyme required FADH₂ and catalyzed the reduction of the methylene group of N⁵,N¹⁰ -methylene tetrahydrofolate to the methyl group of N⁵ -methyl tetrahydrofolate. The pH optimum of the bovine brain reductase occurred at a pK of 6.5. The enzyme proved quite unstable. Both air oxidation and prolonged periods of storage at -20° inactivated the enzyme.     

Serine Transhydroxymethylase: A Simplified Radioactive Assay; Purification and Stabilization of Enzyme Activity Employing Affi-Gel Blue

An improved radioactive assay has been developed for serine transhydroxymethylase. This assay involves the direct measurement of the [¹⁴C]HCH0 which is generated when [3-¹⁴C]-serine is employed as the substrate. The new assay eliminates 14 the need for a solvent extraction of a [C]HCHO-dimedon adduct which is the basis of the assay devised by Taylor and Weissbach.

The enzyme has been purified employing Affi-Gel Blue. The purified enzyme retains full activity when bound to this affinity chromatography matrix and can be stored in this state at 4° indefinitely.     

Central cell nuclear-cytoplasmic incongruity:a mechanism for segregation distortion in advanced backcross and selfed generations of (Allium cepa L. x Allium fistulosum L.) x A. cepa interspecific hybrid derivatives

A model is presented as an explanation for an anomaly observed in germination and establishment and isozyme segregation patterns in Allium cepa x A. fistulosum F2BC3 populations generated in an introgression-breeding program. The F1BC3 parent of these populations was selected for its heterozygous PGI phenotype, Pgi-1(2/3); Pgi-1(2) was inherited from an A. cepa (Ac) seed parent and Pgi-1(3) from an A. fistulosum (Af) pollen parent. Germination and establishment was recorded for the F2BC3 progeny population. Segregation of Ac and Af Pgi-1 alleles was investigated in F2BC3 seeds and embryo and endosperm tissue was isolated and tested for isozyme expression. A pooled goodness-of-fit test of the segregation of Pgi-1 alleles in the populations to the expected Mendelian 1:2:1 ratio using the chi-square statistic gave a chi2 = 185.9, well beyond the accepted limits at 2 degrees of freedom. The 1:2:1 ratio expected for simple Mendelian inheritance was rejected, while a pooled chi-square goodness-of-fit test of the segregation of Pgi-1 alleles in the populations fit a 1:1 ratio with a chi2 = 0.203, based on the incongruity model. We present here the central cell nuclear-cytoplasmic incongruity hypothesis to explain the observed anomalies.     

Patterns of population genetic variation in sympatric chiltoniid amphipods within a calcrete aquifer reveal a dynamic subterranean environment

Calcrete aquifers from the Yilgarn region of arid central Western Australia contain an assemblage of obligate groundwater invertebrate species that are each endemic to single aquifers. Fine-scale phylogeographic and population genetic analyses of three sympatric and independently derived species of amphipod (Chiltoniidae) were carried out to determine whether there were common patterns of population genetic structure or evidence for past geographic isolation of populations within a single calcrete aquifer. Genetic diversity in amphipod mitochondrial DNA (cytochrome c oxidase subunit I gene) and allozymes were examined across a 3.5 km² region of the Sturt Meadows calcrete, which contains a grid of 115 bore holes (=wells). Stygobiont amphipods were found to have high levels of mitochondrial haplotype diversity coupled with low nucleotide diversity. Mitochondrial phylogeographic structuring was found between haplogroups for one of the chiltoniid species, which also showed population structuring for nuclear markers. Signatures of population expansion in two of the three species, match previous findings for diving beetles at the same site, indicating that the system is dynamic. We propose isolation of populations in refugia within the calcrete, followed by expansion events, as the most likely source of intraspecific genetic diversity, due to changes in water level influencing gene flow across the calcrete.     

DNA integrity and transgene expression after passage through the NOGA needle catheter used for therapeutic myocardial angiogenesis

BACKGROUND: The NOGA (Biosense Webster, Markham, ON, Canada) injection catheter is an innovative navigational device that provides an ideal platform for intra-myocardial injection material. However, injection through a long (1.91 m), narrow (27G) nitinol needle could result in deterioration in the integrity and functionality of DNA. METHODS: To test this possibility, DNA in plasmid form (pcDNA3.1) containing the Lac Z transgene (250 micro l) was passed through the NOGA needle using a hand-held 1 cc syringe at a gentle hand injection pressure (43 +/- 3 PSI, 3.0 +/- 0.2 kg/cm(2)) or at maximal manual pressure (90 +/- 6 PSI, 6.3 +/- 0.4 kg/cm(2)), either once or 20 times. This DNA, compared to DNA not passed through the NOGA needle (control), was then used to transfect primary cultures of rat skin fibroblasts (FB) from Fisher 344 rats and the cells were subsequently stained for beta galactosidase (betagal). RESULTS: Transfection efficiency was significantly reduced by passing the DNA through the needle at both 43 +/- 3 PSI (78 +/- 4% of control, n = 10, P < 0.05 versus control) and 90 +/- 6 PSI (66 +/- 4 % of control, n = 10, P < 0.01 versus control, P < 0.02 versus 43 +/- 3 PSI). Passage of the DNA through the NOGA needle 20 times resulted in a transfection efficiency of only 5 +/- 1% of control (n = 20, P < 0.1 x 10(-11) versus control). Capillary Electrophoresis revealed that the reduction in transfection efficiency was due to a conformational change in the DNA from predominantly supercoiled to nicked and linearized DNA. Transfection efficiency as compared with control decreased as the concentration of the DNA solution which was passed through the needle was increased from 0.3 micro g/ micro l to 2.4 micro g/ micro l. Recovery experiments confirmed that the reduction in transfection efficiency was not due to loss of DNA by binding to the NOGA needle. CONCLUSION: These results suggest that DNA is susceptible to shear forces when injected through the NOGA needle even at nominal clinical injection pressures, suggesting that careful and controlled injections will be required to achieve optimal gene integrity and expression.