Interplay of genes in plant-pathogen interactions: In planta expression and docking studies of a beta 1,3 glucanase gene from Piper colubrinum and a glucanase inhibitor gene from Phytophthora capsici.

Oomycete pathogen, Phytophthora capsici is devastating for black pepper (Piper nigrum L.) and causes foot rot disease at all stages of plant growth. Phytophthora secretes a glucanase inhibitor protein (GIP), which is capable of inhibiting defence proteins like endoglucanases. In this particular study Quantitative PCR analysis, molecular docking studies and analysis of sequences of Glucanase inhibitor protein and beta-1,3 glucanse genes were done mainly depending on the data derived from Phytophthora capsici whole genome sequencing and Piper colubrinum RNA-sequencing (RNA-Seq). Amino acid sequence length of GIP gene from P. capsici was about 353 amino acids and that of glucanase pcEGase gene from P. colubrinum was about 312 amino acids. GIP gene from P. capsici showed high level of expression at early hours of the inoculation time period and pcEGase gene showed high level of expression at 16 hpi. High level of expression of pcEGase gene at 16 hpi is an indication that the GIP gene is successfully inhibited by the glucanase protein from the plant. Moreover insilico studies gave some hint on the importance of certain sites on the surfaces of both interacting proteins that might be having a role in binding of the two proteins and subsequent reactions thereof. Insilico analysis also conclusively proved that inhibition of glucanase inhibitor protein is mainly caused by recognition of an arginine as well as an isoleucine residue during the interaction of the two proteins.

Pattern of cardiac fibrosis in rabbits periodically fed a magnesium-restricted diet and administered rare earth chloride through drinking water.

It has been postulated that causation of the tropical cardiomyopathy endomyocardial fibrosis (EMF) is linked to magnesium (Mg) deficiency and cardiac toxicity of the rare earth element cerium (Ce). The aim of the present study was to define the myocardial lesions in rabbits that were fed on Mg-restricted diet (70-80 ppm) periodically and were provided drinking water contaminated with rare earth chloride (1 g/L). Forty New Zealand white rabbits were divided into four groups following a 2 x 2 factorial design. Two groups were periodically fed on Mg-restricted diet with one of them receiving water contaminated with rare earth chloride. The other two groups were continuously fed on Mg-sufficient diet (350-400 ppm) with one of them receiving water contaminated with rare earth chloride. All animals were sacrificed at the end of 6 mo. Cardiac tissues were subjected to histology, elemental analysis (calcium [Ca], Mg, and Ce) and estimation of collagen content and collagen phenotypes. Histological lesions were compared with those of EMF in humans and those of acute Mg deficiency in animals. The results suggest that in rabbits, recurrent episodes of Mg deficiency lead to myocardial fibrosis similar to the pattern observed in human EMF.

An electronic device to record behavioural activity of bivalves.

An electronic device to record the valvular movements of clams was fabricated using a Hall effect transducer. It was used to record the responses of Anadara granosa, an arcid clam harvested from coastal waters of Bombay, to a chemical toxicant (10 ppm CuSO4) after 96 hr exposure to naphthalene (5, 10 and 15 ppm). The clams exposed to naphthalene did not respond to the presence of a chemical toxicant (10 ppm CuSO4) while the control clams responded and closed their shells rapidly.

Cerium levels are elevated in the serum of patients with endomyocardial fibrosis (EMF).

The geochemical hypothesis on endomyocardial fibrosis (EMF) links causation of the disease to increased levels of cerium in the heart. Since cardiac tissues are not easily accessible from patients, we explored whether cerium can be detected in the serum using neutron activation analysis (NAA). Cerium levels in serum of EMF patients were significantly elevated (p < 0.05) compared to controls.

Levels of cerium in the tissues of rats fed a magnesium-restricted and cerium-adulterated diet.

Cerium, a lanthanide, is the most abundant rare earth element present in monazite and is biologically active. It has been postulated that cerium toxicity in conjunction with magnesium deficiency causes tropical endomyocardial fibrosis, a restrictive human cardiomyopathy (Valiathan et al. 1989; Valiathan and Kartha 1990). Generally, lanthanides are known to be poorly absorbed (Durbin et al. 1956; Evans 1990). The present study was carried out to ascertain whether magnesium deficiency promotes accumulation of cerium in various organs of rats.

Magnesium levels in serum and erythrocytes of children from Kerala.

BACKGROUND: Magnesium is required in higher quantities, during the phase of rapid growth, in children. Its level in the ground water in Kerala is low. This can cause magnesium deficiency especially in children from the lower socio-economic groups who also suffer from nutritional insufficiency. METHODS: We compared the serum and erythrocyte magnesium levels of school children from high and low (agricultural labourers and fisherfolk) socio-economic groups. These levels were determined using atomic absorption spectrophotometry. Body mass indices and haemoglobin levels were used as indirect measures of nutritional status. RESULTS: Serum and erythrocyte magnesium levels were significantly lower in both boys and girls from low socio-economic groups who also had lower body mass indices. CONCLUSION: Nutritional insufficiency is prevalent in children from the low socio-economic groups and is associated with low serum and erythrocyte magnesium levels.

The plastic envelope method, a simplified technique for culture diagnosis of trichomoniasis.

Although culture of Trichomonas vaginalis is more sensitive than wet mounts in the diagnosis of trichomoniasis, the lack of convenience of culture prevents it from being widely used. To improve the acceptability of diagnosis by culture, a plastic envelope method (PEM) was devised. PEM permits both immediate examination and culture in one self-contained system. The medium consists of dry ingredients that are reconstituted with water before use. The effectiveness of immediate examinations by PEM was compared with that of wet mounts, and the effectiveness of culture by PEM was compared with that of culture in Trichomonas Medium No. 2 (Oxoid). Of 710 vaginal secretion specimens from symptomatic and asymptomatic women that were tested by the four methods, 62 (9%) were positive for T. vaginalis. The sensitivity was 66% by wet mount, 66% by immediate examination by PEM, 89% by cultures in Oxoid medium, and 97% by culture by PEM. The two culture methods had equivalent sensitivities but were significantly (P less than 0.0001) more sensitive than the two immediate methods. The combined immediate examination by PEM plus culture was more convenient to use than wet mounts plus culture in Oxoid medium. The long shelf-life of PEM's dry medium and its anticipated low cost are additional advantages.

A geochemical basis for endomyocardial fibrosis.

Analysis of hearts of patients dying from endomyocardial fibrosis showed a significantly greater concentration of cerium, a lanthanide present in leafy vegetables and root tubers, than in control hearts. This may be important in the pathogenesis of the disease and provides a geographical basis for the prevalence of the disease in the tropics.

Changes in enzymes of hepatic rough and smooth microsomes during postnatal development and ageing of rats.

Significant changes are observed in wet weight, microsomal protein content and enzymes of purified rough and smooth microsomes of liver during postnatal development and ageing of female Wistar rats. Protein content of total microsomes increases up to 15 days of age and remains steady during subsequent development, unlike that of rough and smooth microsomes which shows changes throughout the same period. Activities of cytochrome P-450, cytochrome b5 and NADPH-cytochrome c reductase increase during the period of maturation and decline during senescence. The decrease during senescence is at different rates in the two microsomal fractions. Microsomal glucose-6-phosphatase, but not adenosine triphosphatase, shows a similar increase during development and decrease during senescence.

Differences in lipid peroxidation of rat liver rough and smooth microsomes.

The rough and smooth microsomes of rat liver show significant differences in lipid peroxidation induced by both NADPH and ascorbate. The parameters studied include kinetics, response towards cofactors and sensitivity to inhibitors. Smooth microsomes are more prone to lipid peroxidation with increasing concentrations of NADPH, Fe3+, ascorbate and Fe2+, and are more susceptible to inhibitors than rough microsomes. Smooth microsomes also contain higher amounts of ascorbic acid, NADPH cytochrome c reductase and total lipids, besides possessing a higher degree of unsaturation in lipids, all of which promote lipid peroxidation. Our results suggest that, although smooth microsomes are more sensitive to lipid peroxidation, they are compensated for by being more sensitive to inhibitors of lipid peroxidation.

Age-related effect of cycloheximide on lipid peroxidation in rough and smooth microsomes of rat liver.

Cycloheximide, at a nonlethal dose of 2 mg/kg body weight, has different effects on microsomal in vivo lipid peroxidation in different age groups. In general, the antibiotic increases microsomal lipid peroxidation in newborn and 1-year-old rats, but decreases it in 15- and 75-day-old rats. Low doses of cycloheximide induces lipid peroxidation in vitro whereas higher doses cause inhibition. The degree of change differs in the two microsomal fractions. The sucklings are more susceptible to such a change than the older rats. In vivo lipid peroxidation in rat liver homogenate and rough and smooth microsomes declines as a function of age. Smooth microsomes show more lipid peroxidation than the rough in the different age groups.

Effect of cycloheximide on hepatic microsomal lipids as a function of age in rats.

Cycloheximide, at a non-lethal dose of 2 mg/kg body weight, increases the level of total lipids and major lipid fractions in total, rough and smooth liver microsomes obtained from suckling, adult and old rats, but not in the newborns. The rates of increase differ in the different age-groups and fractions. Total lipids and phosphatidyl choline of rough and smooth microsomes in adult rats reach control levels at 6 h after the antibiotic treatment. Phospholipid fractions of old rats tend to approach control levels by 6 h after treatment whereas cholesterol levels remain relatively high. Total lipids, phosphatidyl choline and phosphatidyl ethanolamine of total, rough and smooth microsomes show significant quantitative differences during development.

Effect of cycloheximide on deciduoma morphogenesis and implantation in rats.

Intraperitoneal administration of cycloheximide (1 mg/kg body weight) to rats immediately after an artificial deciduoma induction inhibits the development of decidual tissue. Besides inhibiting the differentiation of stromal to decidual cells, wet weight and levels of uterine protein and RNA are low following the antibiotic treatment. Injection of the drug (1 mg/kg body weight) into pregnant rats, either on the eve of Day 4 or in the morning of Day 5 of pregnancy, does not prevent implantation but interferes with the growth of embryos.