Water relations in three species of theConvolvulaceae in the Indian arid zone

The relationship of water deficit, actual water content, area, water loss and stomatal behaviour in leaves of different insertion levels of three members of Indian arid zoneConvolvulaceae—Merremia aegyptia, M. dissecta andIpomoea pes-caprae were measured simultaneously in the month of May, 1974, when field conditions were extremely adverse for growth. The two former species loose far more water than the latter. The values measured varied considerably with the leaf insertion levels and they reversed inI. pes-caprae when compared withMerremia species.     

Platelet count and adhesiveness on induction to high altitude by air and road

Platelet count and adhesiveness (PA) were estimated in 87 normal lowlanders at sea level. They were randomly divided in three groups. Group A was taken to 3 660 m by air, group B by rapid road ascent and group C by road after acclimatisation enroute. Estimations were repeated serially during stay at high altitude and then on return to sea level. The subjects were divided into symptomatic and asymptomatic groups based on their score on a symptom score chart. Some subjects of the air induced group (A) developed significant symptoms and showed a significant rise in PA on days 2 and 10 of exposure. Remaining subjects of group A and all subjects of road inducted group (B and C) remained asymptomatic and showed no change in PA. No significant change in the platelet counts in any of the lowlanders was noted on exposure to high altitude. The significance of these findings is discussed.     

Assessment of observer variability in the classification of human cataracts.

An in vitro cataract classification system was developed in our laboratories and used to demonstrate a relationship between sustained aspirin intake and the apparent deceleration or retardation of human cataract formation. The purpose of this investigation was to assess the reliability of this cataract classification schema. Sets of extracted human cataractous lenses, which had been photographed in vitro, were randomly assigned to five observers. The task was to classify the lenses on the basis of nuclear and cortical involvement, as reflected in color and area changes along five groupings. Assessments were made on the basis of both intraobserver and interobserver agreement levels, corrected for chance (weighted kappa values). All five examiners evidenced levels of intraobserver agreement which ranged between "Good" and "Fair" and "Excellent" (.46-.83). Each of the five observers was ranked on the basis of his agreement levels with the remaining four observers. The results followed a predictable pattern such that the more experienced the observer in classifying cataracts, the more consistent his rankings vis-à-vis the remaining four evaluators. These results are discussed in the general context of observer variability studies in the field of medicine.     

Induction of estrus in anestrous cows treated with 'Fertivet'

The effectiveness of 'Fertivet' (180 mg. Cisclomiphene Citrate and 120 mg. Transclomiphene citrate mixture) in the induction of estrus and fertility was tested on sixteen anestrous cows. Of all the animals treated 14 (97.5%) expressed estrus and 8 (57.1%) conceived. Among the three breeds of cows treated, 5 out of 5 Brown Swiss, 4 out of 5 Jersey cross breeds and 5 out of 6 Sahiwal (Zebu) cows expressed estrus. These results indicate the usefulness of 'Fertivet' in the induction of fertile estrus in cows.     

Effect of boron on the pollen vitality and yield of rice plants (Oryza sativa L. var. Jaya)

Summary Rice plants were grown in sand cultures with nutrient solution including boron at 0, 1, 2.5 and 5 ppm concentrations.In general, supply of boron improved the pollen vitality of rice flowers. It was stimulating up to 2.5 ppm concentration in the nutrient solution, beyond which (i.e., at 5 ppm) inhibitory effects appeared. The availability of boron also increased the yield of rice grains in the same order.Stimulating effects of boron may be linked with greater availability of sugars, increased enzymatic activity and respiration which favoured better growth of pollen. Inhibitory effects of stronger concentration of boron (5 ppm) may be related with physiological depression and injury to protoplasm itself.     

Biochemical characteristics,metabolism, and antitumor activity of several acetylated hexosamines

We have synthesized several potential inhibitors and/or modifiers of the carbohydrate portion of plasma membrane glycoconjugates. These include fluorinated and actylated analogs of D-glucosamine, D-galactosamine, and D-mannosamine. These compounds have been tested to determine their effects on both [¹⁴C] glucosamine and [³H] leucine incorporation into glycoconjugate and on cell growth and viability using P-288 murine lymphoma cells maintained in tissue culture. The most cytotoxic agent tested was 2-acetamido-2-deoxy-1,3,4,6-tetra-O-acetyl-β-D-glucopyranose or simply β-pentaacetylglucosamine which prevented cell growth at 10^?4–10^?3 M. β-Pentaacetylglucosamine cytotoxicity was correlated with its high lipid solubility, having an octanol/water partition coefficient of 0.424 as compared with 0.278 for the β-anomer and 0.017 for N-acetylglucosamine. In vitro metabolism studies with [¹⁴C]-and/or [³H]-labeled pentaacetylglucosamine have indicated intracellular de-O-acetylation leading to the biosynthesis of UDP-N-acetylglucosamine, followed by the incorporation of this sugar into cellular glycoprotein. Concomitant with the formation of increased amounts of this nucleotide sugar, intracellular UTP and CTP pools fell to one third normal within 3 h after the administration of 1 mM pentaacetylglucosamine. At present it is unclear whether the cytotoxicity of β-pentaacetylglucosamine or other similar agents is due to alterations in nucleotide and nucleotide-sugar pools causing a decrease in energy charge and polynucleotide biosynthesis or is due to a direct effect on membrane glycoconjugate biosynthesis.     

alpha-adrenergic receptor in rat heart. Effects of thyroidectomy.

The effects of thyroid status on alpha-adrenergic receptors in the rat myocardium were investigated. The potent antagonist [3H]dihydroergokryptine was used to identify alpha-adrenergic receptors in rat heart particulate and sarcolemmal fractions. Administration of triiodothyronine to thyroidectomized rats decreased specific binding to alpha-adrenergic receptors in heart particulate and sarcolemmal fractions by 41% and 45%, respectively. Scatchard analysis revealed that the cardiac sarcolemmal fraction from thyroidectomized rats contained 29.3 fmol/mg of protein, as compared with 17.0 fmol/mg of protein found in the heart preparation of thyroidectomized rats treated with triiodothyronine. The equilibrium dissociation constants for the interaction of receptors with dihydroergokryptine were similar (about 1.5 nM) in the heart sarcolemmal fractions derived from these two groups of rats. The results of this study demonstrate that thyroid hormone can regulate the number of cardiac alpha-adrenergic receptors. In addition, there appears to be a reciprocal relationship between alpha-adrenergic and beta-adrenergic receptors in the rat myocardium.