Decreased atrial natriuretic factor receptors and impaired cGMP generation in glomeruli from the cardiomyopathic hamster

To determine a possible basis for the decreased action of atrial natriuretic factors (ANF) in congestive heart failure, we compared the cardiomyopathic hamster (CMH) in frank congestive failure, and the age-matched, normal, F1B strain of Golden Syrian Hamsters. Scatchard analysis of competitive binding studies revealed two classes of glomerular receptors. The CMH exhibited decreased binding overall and a markedly decreased number of high affinity receptors but comparable receptor affinity compared to the F1B. In contrast, the low affinity receptor population in the CMH had a much greater affinity compared to the F1B while receptor number was similar. Plasma ANF levels were substantially elevated in the CMH compared to the F1B and in-vitro generation of cGMP was significantly lower in the CMH. Such abnormalities could contribute to the resistance to ANF in this disease.     

Anaerobic growth on elemental sulfur using dissimilar iron reduction by autotrophic Thiobacillus ferrooxidans

Abstract Anaerobic growth on elemental sulfur using dissimilar iron reduction by Thiobacillus ferrooxidans has been demonstrated. The ferric ion reducing activity (FIR) of the anaerobic cells was double that of the aerobic cells. Significant differences in inhibition of FIR by respiratory inhibitors were observed between aerobic and anaerobic cells. A higher amount of cytochrome was detected in anaerobic cells compared to aerobic cells. Absorption minima developed with the addition of ferric sulfate in the dithionite reduced cell suspension demonstrated that the ferric ion could accept electrons from the cytochrome system of this bacterium. The possibility of two different electron transport chains in ferric ion reduction is discussed.     

Characterization and physiologic regulation of atrial natriuretic factor receptors in rabbit preglomerular renal microvessels.

There has been no direct demonstration of the presence of guanylate cyclase-linked atrial natriuretic factor receptors in renal preglomerular microvasculature. Using [125I]ANF, we have demonstrated the presence of high affinity (Kd = 80 pM) and low affinity (Kd = 7.2 nM) ANF receptors in membranes derived from rabbit renal preglomerular microvessels (afferent arterioles and interlobular arteries). These microvessels also exhibited the presence of particulate bound ANF-sensitive guanylate cyclase. The density of the high affinity ANF receptor in desoxycorticosterone-treated rabbits on a high-salt diet (31 +/- 3 fmol/mg protein) was nearly half of that seen in rabbits on a normal diet (53 +/- 4 fmol/mg protein; p less than 0.01, n = 4). Data from this study demonstrated the presence of renal preglomerular ANF receptors and suggested that these receptors (perhaps in addition to glomerular ANF receptors) may participate in the regulation of extracellular volume.     

Molecular cloning,characterization and expression of a nitrofuran reductase gene ofescherichia coli

Mini-mu derivatives carrying plasmid replicons can be used to clone genesin vivo. This method was adopted to generate phasmid clones which were later screened for their ability of restore nitrofurantoin sensitivity of a nitrofuran-resistant host by eliciting nitroreductase activity. One phasmid-derived clone (pAJ101) resulted in considerable increase in nitroreductase activity when introduced into a nitrofurantoin-resistant mutant ofEscherichia coli with reduced nitroreductase activity. Subsequently, a 1.8 kb fragment obtained from pAJ101 by partial digestion with 5au3A, was subcloned into pUC18 to yield pAJ102. The nitroreductase activity attributable to pAJ102 was capable of reducing both nitrofurantoin and nitrofurazone. The polypeptides encoded by pAJ102 were identified by the minicell method. A large, well-defined band corresponding to 37 kDa and a smaller, less-defined band corresponding to 35 kDa were detected. Tnl000 mutagenesis was used to delineate the coding segment of the 1.8 kb insert of pAJ102. A 0.8 kb stretch of DNA was shown to be part of the nitroreductase gene. The gene was mapped at 19 min on theEscherichia coli linkage map.     

Effect of cultural conditions on the lipid profile of Thiobacillus ferroxidas

The intensitive investigations on the lipid profile of Thiobacillus ferrooxidans at various culture ages suggest some correlations of the lipid constitutents with the membrane-bound iron oxidation system. Phosphatidic acid, phosphatidyl serine and phosphatidyl ethanolamine were the major polar components; hydrocarbon, triglyceride and diglyceride were the main neutral components. Major fatty acids were C_16:0, C_16:1, C_16:3, C_18:1, C_18:3, C_22:1 while C_20:1, C_20:2, C_12:0, C_14:2, C_18:0, C_18:2, C_20:0, C_22:0 were found in trace amounts which also depended upon the phase of the growth. One lipoamino acid was identified as ornithine lipid in the polar fraction. Each and every component varied to some extent at different growth phasesindicating relationship of these lipids to the iron oxidation system of the strain.     

Structural studies on the specific capsular polysaccharide from Rhizobium trifolii, TA-1

The repeating unit of the specific capsular polysaccharide from the bacterium Rhizobium trifolii (TA)-1 has been shown to contain (a) terminal 4,6-O-(1-carboxyethylidene)-D-galactose (1 residue), (b) (1 → 3)-linked 4,6-O-(1-carboxyethylidene)-D-glucose (1 residue), (c) (1 → 4)-(1 → 6)-linked D-glucose (1 residue), (d) (1 → 4)-linked D-glucuronic acid (1 residue), and (e) (1 → 4)-linked D-glucose (4 residues). The pyruvylated sugars were shown to be positioned sequentially, and at least one other unit was interposed between them and the branch point.     

Effect of hypophysectomy and replacement therapy on fatty acid metabolism in the rat testis

1. The influence of pituitary gonadotrophins and of testosterone on the conversion of linoleic acid into other polyunsaturated fatty acids by rat testicular tissue was studied. 2. In immature hypophysectomized rats, follicle-stimulating hormone caused a threefold increase in the incorporation of radioactivity from [1-(14)C]linoleic acid into testicular lipids; the distribution of (14)C in the polyunsaturated fatty acids, however, was not significantly affected. 3. In mature hypophysectomized rats, the hormonal treatments had less pronounced effects on (14)C incorporation into testicular lipids, but caused a significant increase in the percentage of (14)C incorporated into polyunsaturated fatty acids of the omega-6 series, luteinizing hormone and testosterone having the more pronounced influences. 4. A time-course study of the appearance of radioactivity in the ejaculated spermatozoa of rabbits, after they had been given a tracer dose of [1-(14)C]linoleic acid, indicated that incorporation of radioactivity into spermatozoa occurred during all stages of spermatogenesis.     

Desulphuring of natural gas and petroleum oil by autotrophic Thiobacillus ferrooxidans

Hydrogen sulphide is a common toxic contaminant in natural gas and oil. In this study, the strictly autotrophic bacterium Thiobacillus ferrooxidans , which oxidizes reduced sulphur compounds, was used to desulphur petroleum oil and gas. The reaction was carried out in a closed vessel containing substrate mixed with a bacterial suspension. The significance of the hydrogen sulphide oxidizing activity of T. ferrooxidans is discussed.     

An extensive review on antifungal approaches in the treatment of mucormycosis

During the period of COVID-19, the occurrences of mucormycosis in immunocompromised patients have increased significantly. Mucormycosis (black fungus) is a rare and rapidly progressing fungal infection associated with high mortality and morbidity in India as well as globally. The causative agents for this infection are collectively called mucoromycetes which are the members of the order Mucorales. The diagnosis of the infection needs to be performed as soon as the occurrence of clinical symptoms which differs with types of Mucorales infection. Imaging techniques magnetic resonance imaging or computed tomography scan, culture testing, and microscopy are the approaches for the diagnosis. After the diagnosis of the infection is confirmed, rapid action is needed for the treatment in the form of antifungal therapy or surgery depending upon the severity of the infection. Delaying in treatment declines the chances of survival. In antifungal therapy, there are two approaches first-line therapy (monotherapy) and combination therapy. Amphotericin B ( 1 ) and isavuconazole ( 2 ) are the drugs of choice for first-line therapy in the treatment of mucormycosis. Salvage therapy with posaconazole ( 3 ) and deferasirox ( 4 ) is another approach for patients who are not responsible for any other therapy. Adjunctive therapy is also used in the treatment of mucormycosis along with first-line therapy, which involves hyperbaric oxygen and cytokine therapy. There are some drugs like VT-1161 ( 5 ) and APX001A ( 6 ), Colistin, SCH 42427, and PC1244 that are under clinical trials. Despite all these approaches, none can be 100% successful in giving results. Therefore, new medications with favorable or little side effects are required for the treatment of mucormycosis.