Showing papers on "B vitamins published in 1972"
TL;DR: Overall nutrient concentration was critical, but the larvae tolerated a wide range of levels of glucose and of the amino acid mixture and excessive amounts of lipids were harmful.
60 citations
TL;DR: Delays in morphogenesis at stage 3 can be measured as a precise function of inhibitors (Colcemid, podophyllotoxin, melatonin) of the form y=kxn, where y is delay in hours and k is the concentration of inhibitor in moles.
Abstract: SYNOPSIS. The temporal separation of macromolecular syntheses from protein assembly into microtubular structures has permitted the use of the Stentor ciliated oral membranellar band regenerating system as an assay for mitotic spindle inhibitors (Banerjee & Margulis, 1971). Melatonin, the pineal gland hormone, is additive to Colcemid in this assay; like Colcemid it specifically inhibits band migration as a sensitive function of developmental stage and concentration. Altho the entire process of band formation and cilia regeneration (stages 0–8) is inhibited by melatonin, stage 3 is especially sensitive.
Delay in morphogenesis at stage 3 can be measured as a precise function of inhibitors (Colcemid, podophyllotoxin, melatonin) of the form y=kxn, where y is delay in hours and k is the concentration of inhibitor in moles. Riboflavin (0.2 μM) and nicotinamide (0.2 μM) in combination reversed Colcemid-induced delay in band regeneration, but (unlike melatonin) the vitamins alone were totally without effect on the regenerating system. Therefore melatonin probably interacts with microtubule protein whereas the B vitamins interact in some way with Colcemid to nullify its activity.
37 citations
TL;DR: This is the first case in which any B vitamins have been identified as feeding behaviour activators for a Coelenterate or in which reduced glutathione or amino acids besides valine and glutamine have been similarly identified for a sea anemone.
21 citations
TL;DR: It appears that pyridoxine is required for normal brood rearing in bees which had never eaten pollen and were offered diets consisting of vitamin-free casein and minerals.
Abstract: SummaryColonies of newly emerged bees which had never eaten pollen were offered diets consisting of (A) vitamin-free casein and minerals, or A supplemented with cholesterol and the vitamins of the B group (B), or with the B vitamins but without cholesterol (C), or with cholesterol and the vitamins except pantothenic acid (D), or with cholesterol and the B vitamins except pyridoxine (E), or with cholesterol and the B vitamins except thiamine (F). The colonies reared 5 cycles of brood on diets B, D and F, and 3 cycles on diet C. No adults were produced on diet E, and no larvae were reared to the sealing stage on diet A. It therefore appears that pyridoxine is required for normal brood rearing.
20 citations
TL;DR: Analysis of the pyridoxal-P-phosphorylase b derivative shows that the major changes in enzymic characteristics are primarily due to modification of one group per monomer at a specific site on the enzyme.
14 citations
TL;DR: Successful perfusions have been performed with glands from anaesthetized and from shot animals, although removal of glands from the tranquillized animal under spinal anaesthesia is still preferred, and evidence has been obtained suggesting that kinins or similar substances may be formed during perfusion.
Abstract: Improvements to a previously reported technique for the perfusion of isolated goat mammary glands are described. Secretion of milk of relatively normal composition in vitro has been maintained at approximately 50% of the in vivo rate for about 12 hr. Factors found to be important for successful perfusion are a normal rate of mammary blood flow, the provision of adequate glucose, acetate and amino acids, and the inclusion in the circuit of an efficient oxygenator and dialyser.
Contrary to earlier results successful perfusions have been performed with glands from anaesthetized and from shot animals, although removal of glands from the tranquillized animal under spinal anaesthesia is still preferred. There was a marked dependence of milk secretion rate on the rate of blood flow below a critical value, but at supra-normal flows there was no correlation between these variables. Evidence has been obtained suggesting that kinins or similar substances may be formed during perfusion.
The specific dependence of milk secretion on glucose is again stressed. Other carbohydrates sustained oxygen consumption similar to that shown with glucose, but by contrast did not support the secretion of water, a small amount of milk low in lactose but high in fat and protein being produced. Although milk fat secretion was dependent on the provision of acetate, the omission of β-hydroxybutyrate, lactate and neutral fat (all shown to be absorbed by the gland in vivo) from the substrate mixture did not seriously impair milk fat secretion in vitro. Amino acids were shown to be necessary for normal rates of milk protein secretion, but the alteration of the substrate mixture to correspond to the amino acid absorption observed in vivo produced no significant change in milk secretion from that observed when amino acids were infused at rates corresponding to their occurrence in casein. The infusion of B vitamins and various hormones had no effect on milk secretion. Perfusions carried out with a conscious goat in circuit were no more successful than the completely in vitro system, but glands grafted onto recipient goats (even males) following complete removal from the donors produced substantially more milk than in vitro preparations.
In some experiments milk [Na] and [Cl] increased during perfusion while [K] and [lactose] decreased, these trends being apparent in milk secreted before perfusion was begun and being probably due to the oxytocin used to produce milk ejection. In other experiments milk [Na] and [Cl] showed little change but [K] and [lactose] tended to rise.
Possible factors limiting the performance of perfused organs are discussed.
13 citations
10 citations
TL;DR: The Saskatchewan-grown wheat, barley, and oats contained considerably more crude protein than has been reported elsewhere and the nicotinic acid content of barley and oats was greater than published values, whereas the pantothenic acid level in oats appeared low.
Abstract: Two varieties each of wheat and oats and three varieties of barley were grown during a 5-year period at 16 locations representing the main soil types and zones in Saskatchewan. Year (climatic) factors were responsible for significant variations in the concentration of proximate fractions and B-vitamins in each crop. The effects of soil type and zone on nutrient levels were relatively small and inconsistent. The season × soil zone interactions were significant but the mean squares were very small. Differences between varieties in content of proximate fractions were similar to those reported in the literature and significant differences in B-vitamin content were also noted. The Saskatchewan-grown wheat, barley, and oats contained considerably more crude protein than has been reported elsewhere. In addition, the nicotinic acid content of barley and oats was greater than published values, whereas the pantothenic acid level in oats appeared low. Coefficients of variation for the proximate fractions varied betw...
8 citations
01 Sep 1972
TL;DR: Methods for detecting vitamin deficiencies also are of practical importance in neurology, including tests for transketolase activity in red cells indicative of thiamine, or the B12 absorption or Schilling test.
Abstract: Deficiencies of one of the vitamins of the B complex are a pathogenetic factor in some encephalopathies and neuropathies. Wernicke's encephalopathy due to inadequate thiamine uptake in alcoholics, or pellagra encephalopathy due to diets deficient in nicotinic acid and tryptophan are both examples of classical deficiency diseases.
2 citations
Dissertation•
01 Jan 1972