Effects of the application of chemical additives to desiccated flax on retting

Summary Application of chemical additives to alter the rate of retting of desiccated flax stems was successful. Treatment with ethylenediaminetetra-acetic acid (EDTA) and urea increased the rate of retting. Increases, in the population of fungal colonisers were observed on urea-treated stems but not after EDTA treatment. Enhanced PG activities were detected in stems treated with EDTA and maimum PL and xylanase activities were detected in stems treated with urea. Urea treated stems produced relatively finer fibres compared to fibres from EDTA treated stems of controls.     

Control of ethanol production by yeast: Role of pyruvate decarboxylase and alcohol dehydrogenase

Summary The critical role of pyruvate decarboxylase (PDC) and alcohol dehydrogenase (ADH) in determining the rate of ethanol production is confirmed using PDC constitutive mutants. By deriving strains with altered levels of these two enzymes, it has been found that a high level of both PDC and ADH is necessary for faster ethanol production.     

Influence of dietary supplementation with thiamine on lead intoxication in rats

The influence of dietary supplementation with thiamine on lead (Pb) contents in blood and tissues, blood δ-aminolevulinic acid dehydratase (δ-ALAD) activity, and urinary excretion of δ-aminolevulinic acid (δ-ALA) was evaluated in male Sprague-Dawley rats. Groups of randomly selected animals were given a thiamine-deficient diet, a diet containing normal thiamine (20 mg/kg), or a thiamine-supplemented diet (50 mg/kg), along with control drinking water or water containing 100 ppm Pb, for 4 mo. Animals fed the thiamine-supplemented diet (50 mg/kg) and Pb showed decreased urinary excretion of δ-ALA and a decreased inhibition of δ-ALAD activity in blood compared to those given Pb with normal thiamine diet. The liver, kidney, and blood of rats receiving supplemental thiamine also contained significantly less Pb than the other two treatment groups given Pb-containing water. The protective effect of thiamine against Pb toxicity may be attributed to its interference with retention of the metal in body tissue, possibly resulting from the formation of excretable thiamine-lead complexes.     

Kinetics of reabsorption of nutrients in renal brush border membrane vesicles from rats with experimental ascending pyelonephritis

The uptake of nutrients was investigated in the renal cortical brush border membrane (BBM) vesicles at different stages of ascending pyelonephritis. There was significant difference (p less than 0.05) in the uptake of D-glucose, L-alanine, L-aspartate, L-lysine and L-proline 3 days postinfection and onwards in both right unobstructed and left obstructed experimental kidneys as compared to the sham operated control. The uptake of D-glucose, L-lysine and L-proline was found to be significantly decreased (p less than 0.05) during the course of infection. While uptake of L-alanine and L-aspartate increased (p less than 0.05) in early stages and decreased (p less than 0.05) in later stages of infection. The differential effect was attributed to the compensatory measure and different kinds of transport systems for different types of amino acids.     

Purification and characterization of metallothionein from liver of cadmium exposed Rhesus monkeys (Macaca mulatta)

Metallothionein (MT) a low molecular weight, Cd-binding, cysteine rich, cytosolic protein has been isolated, purified and characterized from cadmium exposed Rhesus monkeys maintained on protein calorie malnourished (PCM) diet. Metallothionein was resolved into three isoforms i.e. MT_a, MT_b and MTV_c. The ratio of Cd, Zn and Cu varied in these isometallothioneins. MT_c was the major isometallothionein. UV Spectra of MT_c revealed the presence of mercaptide bonds and absence of aromatic amino acids. These observations were further confirmed by amino acid analysis of MT_c which demonstrated high cysteine content (22.6) followed by serine, glycine and lysine. The molecular weight of MT_c as determined by gel filtration and amino acid analysis was 13000 and 6398 daltons respectively. This demonstrates that MT_c is a non-globular ellipsoid polypeptide. MT_c showed a unique property of binding selenium. Monkey liver metallothionein was immunologically identical with human metallothionein. All the characteristics of MT_c obtained in the present study reveal a similarity between monkey and human metallothionein probably due to closer phylogenetic relationship between the two species.     

Mycoplasmalike Organisms (MLOs) Associated With the Witches' Broom Disease of Poplar

The witches' broom disease has been recently observed on poplars in Paris and its suburbs. The incidence of the disease appeared to be considerably high along main roads. The electron microscopic examination of 350 nm thick sieve tube sections revealed the presence of wall-less mycoplasmalike organisms (MLOs) in diseased samples of Populus alba var. nivea Wesm. They could not be found in their healthy counterparts.     

Study on growth and biomass of underground organs ofTypha angustata Bory & Chaub

Underground and aboveground biomass and their ratios at flowering time in different natural stands of Typha angustata near Jaipur, India were studied in the field and experimentally over a period of eleven months (June to April). The underground biomass was 40–50% of the aboveground biomass in both natural and experimental conditions.     

Guaianolides from Saussurea affinis

Cynaropicrin, 11βH-11,13-dihydrodesacylcynaropicrin, aguerins A and B, isoamberboin and the new guaianolides saussureolide and 11βH-11,13-dihydrodesacylcynaropicrin 8-β-d-glucoside were isolated from Saussurea affinis.     

Methylation of transfer RNA during transformation of human lymphocytes by phytohemagglutinin

Methylation of transfer RNA during phytohemagglutinin induced transformation of human lymphocytes was studied by labeling the tRNA $\text{in}\text{vivo}$ with (methyl-H³)-methionine and measuring the distribution of tritium in the methylated nucleotides. An alteration in the pattern of methylation occurred within hours after PHA-stimulation and this change was maintained through several cell generations. There was a 50 to 94% increase in the relative amount of methylated N²-methyl-guanine (1 to 3 hr) and a 40 to 59% decrease in the relative amount of 1-methyladenine (1 to 12 hr). Treatment of the stimulated cells with Actinomycin D prevented the subsequent methylation not tRNA. However, inhibition of protein synthesis by puromycin did not effect the early changes observed in the methylation of tRNA.