Pulmonary function in nonsmoking chronic alcoholics

To our knowledge, this is the first published report to describe pulmonary function in nonsmoking alcoholics who also do not have a history of respiratory illness. This study, in sharp contrast to those that include smokers, shows that pulmonary function, including diffusing capacity, is within normal limits. The "true shunt" noted in all subjects who underwent blood gas studies is probably related to liver disease. Our study also suggests that gas exchange may be impaired even in patients with mild alcoholic liver disease (table 3). When the airway closes prematurely as a result of blood vessel dilatation and/or interstitial pulmonary edema, ventilation decreases. This results in appreciable shunting via portopulmonary and intrapulmonary communications and in a very low ventilation/perfusion ratio of the dependent lung zones. We consider that application of any formula to separate the effects of tobacco from those of alcohol will produce, at best, approximate values.

Modulation of Chloroplast Fructose-1,6-bisphosphatase Activity by Light

Inhibitor experiments indicate that light effect mediator(II) which is reductively activated by transfer of electrons from the photosynthetic electron transport system at or beyond ferredoxin, is involved in activation by light of fructose-1,6-bisphosphatase in the pea plant. Activation proceeds optimally when the pH is low and Mg(2+) is 10 millimolar. Modulation by light results in increases in maximal velocity, apparently as a result of changes in enzyme conformation. Pea leaf thylakoids are effective in modulating the activity of glyceraldehyde-3-phosphate dehydrogenase but not of fructose-1,6-bisphosphatase or glucose-6-phosphate dehydrogenase in Kalanchoë stromal extracts. There is apparently species specificity for modulation of some, but not all, of the modulatable enzymes.

Light modulation of the activity of carbon metabolism enzymes in the crassulacean Acid metabolism plant kalanchoë

When intact Kalanchoë plants are illuminated NADP-linked malic dehydrogenase and three enzymes of the reductive pentose phosphate pathway, ribulose-5-phosphate kinase, NADP-linked glyceraldehyde-3-phosphate dehydrogenase, and sedoheptulose-1,7-diphosphate phosphatase, are activated. In crude extracts these enzymes are activated by dithiothreitol treatment. Light or dithiothreitol treatment does not inactivate the oxidative pentose phosphate pathway enzyme glucose-6-phosphate dehydrogenase. Likewise, neither light, in vivo, nor dithiothreitol, in vitro, affects fructose-1,6-diphosphate phosphatase. Apparently the potential for modulation of enzyme activity by the reductively activated light effect mediator system exists in Crassulacean acid metabolism plants, but some enzymes which are light-dark-modulated in the pea plant are not in Kalanchoë.

Biochemical basis of hybrid vigour. The genetics of grain weight of Oryza sativa

Four cathodal bands (C1, C2, C3 and C4) of esterase (E1, C1. 3.1) were correlated with the grain weight of rice (Oryza sativa L.). Zymogram patterns indicated intensity differences among these bands infinegrain and coarse-grain varieties. Bands C1. and C2 were dark in fine grain varieties whereas C3 and C4 were dark in coarse grain varieties. These bands were specific to endosperm. Observations on fine-grain (Kalanamak), coarse grain (SR(26)B) varieties and their reciprocal hybrids indicated the presence of 4 esterase loci G1, G2, G3 and G4, corresponding to bands C1, C2, C3 and C4, respectively. A possible model for heterosis in grain weight of rice was proposed which supports the dominance theory of heterosis. In hybrid vigour the 4 esterase loci appear to be associated with grain weight and they complemented each other in an additive manner.

The relation between peroxidase activity and the morphological expression of the hooded gene in barley

Reproductive meristems of the hooded (KK) genotype of barley at the stage of young lemma primordia were injected with the inhibitors sodium azide, hydrazine, and hydroxylamine at concentrations of 10(-3), 10(-4), and 10(-5)M, as well as with phenylboric acid. These treatments all brought about an altered expression of the adult phenotype in the direction of awned (kk) genotype. Analysis of tissues treated with the same reagents revealed a reduction in peroxidase activity which was proportional to the effect of each inhibitor in modifying the phenotypic expression of the gene. Exogenous IAA injected in the same manner brought about a similar modification of the phenotype and parallel reduction of peroxidase activity, but to a lesser degree. These results are believed to be caused by modifications of the action of the IAA oxidase system in the developing meristems.