Influence of pyridoxine supplementation on vitamin B-6 levels in milk of rats deficient in the vitamin

Levels of vitamin B-6 in milk from pyridoxine deficient dams were used as an indicator of the ability of pyridoxine to protect offspring against the effects of the deficiency. Sprague Dawley rats were fed a basal diet containing 30.0 (control) or 1.2 (deficient) mg pyridoxine-HC1/kg diet from weaning throughout growth, gestation and until 5 days postpartum. At this time, deficient dams were supplemented by a single intraperitoneal injection of 600 mug pyridoxine-HC1, or by adding 30 or 60 mg pyridoxine-HC1/kg to the diet. The vitamin B-6 content in milk form the group supplemented by injection exceeded the control level of 38.8 mug/100 ml milk 30 minutes after the injection, and reached a peak level of 110.7 mug/100 ml at 4 hours with a subsequent decline to 27mug/100 ml at 20 hours. In rats supplemented orally with 30 or 60 mg pyridoxine-HC1/kg diet, the vitamin B-6 level in the milk reached the control value in 24 and 6 hours, respectively. At 120 hours, orally supplemented dams had significantly higher levels of vitamin B-6 in the milk than control animals. Vitamin supplementation of dams by a single injection of pyridoxine-HC1 was sufficient to overcome the pyridoxine deficiency syndrome in the pups, but was not adequate for optimum growth.     

Sensitivity of B- and C-DNA forms to modifications by O-methylhydroxylamine

Effects of high concentrations of lithium, cesium and ammonium chlorides on the reaction ability of free CMP and cytosine in free DNA of CD phage with respect to O-methylhydroxylamine (OMHA) are studied. CMP reaction in all the cases takes place mainly for 24 hours. Like classical B-form, native DNA, having C-form in high ionic strength solution (as estimated from circular dichroism data), is not modificated. Thus, the access of some cytosine residues in intraphage DNA to OMHA is due not to the decreased DNA hydratation in situ, but to the presence of differently ordered regions in DNA.     

Growth of yeasts in milk and associated changes to milk composition

The growth of several yeast species in milk containing added sodium chloride (0-15%, w/v) at 25 degrees C and 10 degrees C was examined in conjunction with yeast metabolism of milk constituents. Depending on conditions, all yeasts grew to maximum populations of 10(7)-10(8) cfu/ml. Kluyveromyces marxianus gave strong utilisation of lactose and weak metabolism of citrate, protein and fat with the production of ethanol, glycerol, lactic acid and propionic acid. As measured by the production of free amino acids and free fatty acids, Candida lipolytica and Candida catenulata gave strong proteolytic and lipolytic reactions, the specificities of which appeared to be influenced by temperature and the presence of NaCl. These species also metabolised organic acids. Although giving strong growth responses, Debaryomyces hansenii and Saccharomyces cerevisiae did not metabolise lactose and gave only very weak lipolytic and proteolytic reactions. Citrate was metabolised by D. hansenii but not by S. cerevisiae. Both species produced small amounts of ethanol, glycerol and lactic acid.     

Sequence comparison of the ARG4 chromosomal regions from the two related yeasts, Saccharomyces cerevisiae and Saccharomyces douglasii

A 3.6 kb DNA fragment from Saccharomyces douglasii, containing the ARG4 gene, has been cloned, sequenced and compared to the corresponding region from Saccharomyces cerevisiae. The organization of this region is identical in both yeasts. It contains besides the ARG4 gene, another complete open reading frame (ORF) (YSD83) and a third incomplete one (DED81). The ARG4 and the YSD83 coding regions differ from their S. cerevisiae homologs by 8.1% and 12.5%, respectively, of base substitutions. The encoded proteins have evolved differently: amino acid replacements are significantly less frequent in Arg4 (2.8%) than in Ysc83 (12.4%) and most of the changes in Arg4 are conservative, which is not the case for Ysc83. The non-coding regions are less conserved, with small AT-rich insertions/deletions and 20% base substitutions. However, the level of divergence is smaller in the aligned sequences of these regions than in silent sites of the ORFs, probably revealing a higher degree of constraints. The Gcn4 binding site and the region where meiotic double-strand breaks occur, are fully conserved. The data confirm that these two yeasts are evolutionarily closely related and that comparisons of their sequences might reveal conserved protein and DNA domains not expected to be found in sequence comparisons between more diverged organisms.     

Review: the Cct eukaryotic chaperonin subunits of Saccharomyces cerevisiae and other yeasts

All eight of the CCT1-CCT8 genes encoding the subunits of the Cct chaperonin complex in Saccharomyces cerevisiae have been identified, including three that were uncovered by the systematic sequencing of the yeast genome. Although most of the properties of the eukaryotic Cct chaperonin have been elucidated with mammalian systems in vitro, studies with S. cerevisiae conditional mutants revealed that Cct is required for assembly of microtubules and actin in vivo. Cct subunits from the other yeasts, Candida albicans and Schizosaccharomyces pombe, also have been identified from partial and complete DNA sequencing of genes. Cct8p from C. albicans, the only other completely sequenced Cct protein from a fungal species other than S. cerevisiae, is 72% and 61% similar to the S. cerevisiae and mouse Cct8 proteins, respectively.     

Folic acid, riboflavin, thiamine, and vitamin B-6 status of a group of first-time blood donors

Chronic hypoxia has been shown to augment the production of antioxidants in rat lungs and to reduce airway hyperreactivity in patients with asthma. This study investigated indirectly whether this increase in antioxidants occurs in guinea-pig lungs and whether the increased antioxidants affect hyperpnoea-induced bronchoconstriction (HIB). Guinea-pigs were divided into four groups: control (n=8); chronic hypoxia (n=7); capsaicin pretreatment (n=7); and capsaicin pretreatment plus chronic hypoxia (n=8). Control animals were not treated. Animals in the hypoxia group were intermittently exposed to an ambient pressure of 380 mmHg for 7 days. A five day pretreatment of capsaicin was used to deplete tachykinins. In the last group, animals were pretreated with capsaicin, followed by a seven day hypoxic exposure. On the day of the study, airway function was examined in the anaesthetized and paralysed animal. Fifteen minutes of hyperpnoea caused marked decreases in the maximal expiratory flow rate at 15% vital capacity, forced expiratory volume in one second, and dynamic respiratory compliance, indicating HIB. This HIB and plasma substance P levels were significantly attenuated by chronic hypoxia, capsaicin pretreatment, and capsaicin pretreatment plus chronic hypoxia. Furthermore, chronic hypoxia attenuated airway constriction induced by xanthine-xanthine oxidase. The results suggest that chronic hypoxia attenuates hyperpnoea-induced bronchoconstriction via a decrease in the oxygen radical-mediated release of tachykinins.     

Regulation of biologically active dimeric inhibin A and B from infancy to adulthood in the male

Inhibins are glycoprotein members of the transforming growth factor-beta family that have been implicated in the control of spermatogenesis by exerting a negative feedback on FSH secretion. In addition, locally produced inhibins may play a role in paracrine regulation of testicular function. Immunoassays were used to measure the two biologically active dimeric forms of inhibin (inhibin A and B) in serum, seminal plasma, and urine. To better define their actions, inhibins were measured in the male during infancy, sexual maturation, and senescence. Inhibin B but not A was measurable in the serum of male newborns, infants, children, and adults. In adult males, measurable levels of inhibin B were detected in the seminal plasma but not the urine. The circulating levels of inhibin B increased shortly after birth and peaked at 4-12 months of age (210 +/- 31 pg/mL). The concentration measured in the serum then decreased to a low of 81 +/- 12 pg/mL of inhibin B from 3-9 yr of age followed by a gradual increase beginning with the onset of puberty and reaching another peak of 167 +/- 20 pg/mL in males who were 20-30 yr of age. Inhibin B levels then gradually declined with increasing age up through 90 yr of age. Serum levels of gonadotropins and total testosterone production were also measured in these same males. There was a brief increase in the gonadotropins (FSH and LH) during the few months of postnatal development, followed by a decrease to basal levels until the onset of puberty at 10-14 yr of age. Testosterone was also increased in the serum of infants from day 1 through 12 months of age, which decreased in young children but increased again following the elevation of gonadotropins during puberty. In adults aged 20-90 yr, serum levels of inhibin B were inversely proportional to levels of FSH but not LH or testosterone. In males in which a semen analysis was performed, those males with normal semen analysis had a significantly higher inhibin B levels, sperm production, and lower FSH levels than males with either oligospermia or nonobstructive azoospermia. The levels of Inhibin B found in circulation were a good marker for testicular function and could be useful in the diagnosis of patients with semen abnormalities or a complete absence of spermatogenesis. Because this glycoprotein is secreted in high amounts in the prepubertal testis up to 3 yr of age, inhibin B could potentially be used as a marker in the diagnosis of cryptorchidism and precocious puberty.     

Postnatal patterns of fatty acids in brain of progeny from vitamin B-6 deficient rats before and after pyridoxine supplementation

The influence of deficient and adequate maternal intakes of pyridoxine on lipid profiles in brains of progeny at 5, 10, 15, 25 and 50 days of age was studied. The effects of supplementing deficient dams at two different times with pyridoxine on the brain development of progeny were also examined. Three groups of weanling, female rats were fed diets deficient in pyridoxine (1.2 mg pyridoxine-HC1/kg diet) and another group received a control diet (30.0 mg pyridoxine-HC1/kg diet). One deficient group and the control group were fed their diets throughout growth, gestation and lactation. Two groups of dams were fed the deficient diet through growth, gestation and until 5 or 10 days postpartum when pyridoxine was supplemented by feeding the control diet. Body and brain weights were significantly lower in 15, 25 and 50 day-old progeny of deficient dams and deficient dams supplemented at 10 days postpartum. Cerebroside content at 15 days and ganglioside content at 15 and 25 days were significantly lower in brains of pups from unsupplemented deficient dams and deficient dams supplemented at 10 days postpartum. The postnatal development of cerebroside and ganglioside levels in brain was delayed or retarded in brain of pups from unsupplemented deficient dams. Supplementation of dams fed a low level of pyridoxine (1.2 mg/kg diet) with the vitamin beginning at 5 days postpartum reversed all observed effects of the low vitamin intake on brain lipids in progeny.     

Effect of vitamin E on the anticoagulant response to warfarin

To clarify whether vitamin E enhances the pharmacologic effect of warfarin, we completed a double-blind clinical trial in which 21 subjects taking chronic warfarin therapy were randomized to receive either vitamin E or placebo. None of the subjects who received vitamin E had a significant change in the international normalized ratio, and thus it appears that vitamin E can safely be given to patients who require chronic warfarin therapy.     

Dimensional analysis of osteoclastic bone resorption and the measurement of biologically active calcitonin

Calcitonin inhibits bone resorption through a direct action on the osteoclast. We report a quantitative analysis of bone resorption by disaggregated rat osteoclasts. We then used our findings to develop a formal bioassay for calcitonin. Osteoclasts were mechanically disaggregated from neonatal rat long bones and dispersed at low densities on slices of devitalized bovine cortical bone. The resulting areas of bone excavation were quantified to micrometric precision by scanning electron microscopy together with computer-assisted image analysis. These findings were correlated with the volumes of bone resorption in the same slices measured by confocal scanning microscopy for the first time. The total planar areas of bone resorption per slice correlated linearly (r = 0.78) with the confocal microscopic measurements of total volume resorbed, provided that volume was expressed to its two-thirds power. The latter transformation resulted in representations of the determined areas ([length]2) and volumes ([length]3) which were dimensionally consistent. These findings thus demonstrate that osteoclastic bone excavations show a consistent relationship between area and volume and that assessments of the area of excavations accordingly provide an empirical representation of the volume of bone resorbed. Furthermore, in view of the skewed nature of the distributions of area measurements, we assessed the effect of transforming the response variable to derive a metameter, (planar area of resorption)1/2. Such transformed data points, which expressed the data in the dimensions of [length], were more normally distributed than the raw data points and had more stable variances over a wider concentration range. We accordingly determined relative potencies using parallel line analyses on the transformed data. The latter offered a consistent correlation to the volume measurements when these were also converted to dimensions of [length] (r = 0.805). It was confirmed that the inhibition of bone resorption by calcitonins from various species, namely, pig, salmon and eel, was quantitatively dependent upon concentration of the respective peptides. The resulting assay was also found to be sufficiently sensitive to measure picomolar peptide concentrations with a precision, lambda (standard deviation/slope), ranging between 0.3 and 0.8. Finally, we identified factors affecting assay precision and sensitivity.     

Factors which affect the frequency of sporulation and tetrad formation in Saccharomyces cerevisiae baker's yeasts

To clarify the role that respiration, the mitochondrial genome, and interactions of mitochondria and nucleus play on sporulation and to improve the sporogenic ability of several baker's yeasts, an investigation of the effects of different media and culture conditions on baker's yeast sporulation was undertaken. When standard protocols were followed, the sporulation frequency varied between 20 and 60% and the frequency of four-spore asci varied between 1 and 6%. Different presporulation and sporulation media, the use of solid versus liquid media, and incubation at 22 versus 30 degrees C were checked, and the cells were collected from presporulation media in either exponential or stationary phase. Best results, yielding sporulation and four-spore ascus formation frequencies up to 97 and 60%, respectively, were obtained by collection of the cells in exponential phase from liquid presporulation medium with 10% glucose and transfer of them to sporulation medium with 0.5% potassium acetate at 22 degrees C. Under these conditions, the most important factor was the growth phase (exponential versus stationary) at which cells from presporulation medium were collected. Changes in sporulation frequencies were also measured after transfer of mitochondria from different sources to baker's yeasts. When mitochondria from laboratory, baker's, and wine yeasts were transferred to baker's and laboratory petite strains, sporulation and four-spore ascus formation frequencies dropped dramatically either to no sporulation at all or to less than 50% in both parameters. This transfer also resulted in an increase in the frequency of petite mutant formation but yielded similar growth and respiration rates in glycerol.(ABSTRACT TRUNCATED AT 250 WORDS)     

State of biologically active substances in the mother-placenta-fetus system in pregnancy and labor]

Individual development in the course of a generation has an unidirectional, irreversible, "closed", predominantly structly-determined, predominantly autoprogrammed, autoreproducible character. The characteristics of individual development differ in terms of its processes, stages, types and orders. Ontogenesis and ageing of the organism represent the principal processes of individual development. Individual development has three main stages (progressive stage, "plateau" stage and regressive stage). The types of individual development may be grouped into two categories: elementary and complex. The complex types result from the combining in different ways of the elementary types. Similarly, orders of the generations of individual development and hierarchical orders of individual development may be differentiated. Between the processes, stages, types and orders of individual development certain "combining" relationships may appear. The processes, stages and types of individual development as well as their mutual relationships serve both development and stability.     

Time-dose response of Trypanosoma congolense bloodstream forms to diminazene and isometamidium

Trypanosoma congolense bloodstream forms were propagated in vitro axenically in a simplified cultivation medium at 34 degrees C. Viability of a drug-sensitive and a drug-resistant clone were examined for 10 days following exposure to 0.1, 1.0 and 10.0 micrograms ml-1 of diminazene aceturate and 0.1, 1.0 and 10.0 ng ml-1 of isometamidium chloride for various time intervals. Drug-sensitive T. congolense were irreversibly damaged after incubation with 10 micrograms ml-1 or 1 microgram ml-1 diminazene aceturate for 30 min or 2 h, respectively, while drug-resistant trypanosomes were not affected. Exposure to 10 ng ml-1 isometamidium chloride eliminated drug-sensitive trypanosomes after 24 h and drug-resistant trypanosomes after 96 h. The data obtained on in vitro time-dose responses of T. congolense were related to pharmacokinetic data of diminazene and isometamidium in cattle plasma.     

Structures of Cdc42 bound to the active and catalytically compromised forms of Cdc42GAP

The Rho-related small GTP-binding protein Cdc42 has a low intrinsic GTPase activity that is significantly enhanced by its specific GTPase-activating protein, Cdc42GAP. In this report, we present the tertiary structure for the aluminum fluoride-promoted complex between Cdc42 and a catalytically active domain of Cdc42GAP as well as the complex between Cdc42 and the catalytically compromised Cdc42GAP(R305A) mutant. These structures, which mimic the transition state for the GTP hydrolytic reaction, show the presence of an AIF3 molecule, as was seen for the corresponding Ras-p120RasGAP complex, but in contrast to what has been reported for the Rho-Cdc42GAP complex or for heterotrimeric G protein alpha subunits, where AIF4- was observed. The Cdc42GAP stabilizes both the switch I and switch II domains of Cdc42 and contributes a highly conserved arginine (Arg 305) to the active site. Comparison of the structures for the wild type and mutant Cdc42GAP complexes provides important insights into the GAP-catalyzed GTP hydrolytic reaction.     

Effect of treatment with cardiac glycosides and biologically active substances on the state of the lesser circulation according to the electrokymographic data

Electrokymography was used to assess by pulmonary densograms and pulmonary artery pulse curves treatment-induced changes in cardiac contractility and lesser circulation in 455 patients with rheumatic heart disease and stage IIA, IIB, and III circulatory insufficiency. Treatment with cardiac glycosides in combination with metabolic preparations (ATP methionine, vitamin B12, inosine-F, and extract of the heart muscle) leads to a more conspicuous reduction in the symptoms of congestion in the lesser circulation than that encountered in treatment with cardiac glycosides alone. The reduction in these symptoms following treatment with ATP and heart-muscle extract may be explained not only by improved myocardial contractility but also by the direct vasodilating effect of adenyl compounds.     

Acute inflammation induces hyporetinemia and modifies the plasma and tissue response to vitamin A supplementation in marginally vitamin A-deficient rats

Plasma retinol is reduced during numerous infections, and inflammation alters the hepatic synthesis of retinol-binding protein (RBP). In this study, we have investigated the effects of endotoxin-induced inflammation on vitamin A (VA) supplementation in a rat model of marginal VA deficiency. Marginally VA-deficient rats received an intraperitoneal dose of lipopolysaccharide (LPS, n = 14) or saline (n = 10); 6 h later, six LPS + VA and six saline + VA rats received 7.1 micromol VA orally. Twenty-four hours after endotoxin administration, rats with inflammation (LPS) had lower plasma retinol, RBP, and hepatic RBP than saline rats (37, 31 and 44%, respectively, P < 0.05). Inflammation did not affect VA concentrations in liver and perirenal adipose tissue, although kidney VA was reduced relative to saline rats. However, urinary VA was not detected. Eighteen hours after VA supplementation, inflammation reduced the plasma unesterified retinol response (P < 0. 05) in LPS + VA relative to saline + VA rats, although total VA increased as a result of the presence of retinyl esters in LPS + VA rats. Hepatic esterified retinol concentration was reduced (P < 0. 01) in LPS + VA compared with saline + VA rats; however, hepatic unesterified retinol did not differ. Renal total retinol increased in VA-supplemented rats, but urinary retinol excretion, when observed, was low, independently of inflammation. These findings indicate that inflammation-induced hyporetinemia does not necessarily imply a loss of VA, but rather represents a redistribution of tissue VA brought about by a reduced hepatic synthesis of RBP. Practical implications from these collective results are to recommend the determination of both unesterified and esterified retinol to fully assess the plasma response to VA supplementation and to caution the use of VA assessment methodologies that depend on the hepatic synthesis of RBP during acute inflammation.     

Dietary excess of vitamin B-6 affects the concentrations of amino acids in the caudate nucleus and serum and the binding properties of serotonin receptors in the brain cortex of rats

Vitamin B-6 is a cofactor in many reactions of nitrogen metabolism. Deficiency alters tissue amino acid concentrations but effects of excess vitamin B-6 have not been well described. We fed female rats (218 g, 7 per group) 1 (control), 10, 100, 175 or 250x) the National Research Council recommended level of pyridoxine HCl (7 mg/kg) for 10 wk and measured serum amino acids, amino acids and neurotransmitters in brain regions and the binding properties of serotonin receptors in the cerebral cortex using a ketanserin binding assay. Rats were decapitated, and unheparinized blood was obtained. In the caudate nucleus, concentrations of glutamate, threonine, taurine, methionine, gamma-amino-butyric acid and the sum of the essential amino acids in groups 10X and 100X were approximately 130 to 180% of control levels (P < 0.05); groups 1X, 175X and 250X were not different. A similar pattern was seen in the serum for serine, glycine, aspartate and ornithine; the latter two amino acids increased to over 200% of control in group 100X. In the ketanserin binding assay, both the antagonist binding affinity and the maximal number of binding sites were higher for group 100X than for 1X, 175X and 250X, and were higher for 10X than for 1X. Norepinephrine in the raphe nucleus followed a similar biphasic pattern. Excess dietary pyridoxine affected brain and serum concentrations of some amino acids and binding properties of cortical serotonin receptors in a biphasic pattern over the range of concentrations fed in this study.