scispace - formally typeset
Search or ask a question

Showing papers on "B vitamins published in 1983"


Journal ArticleDOI
25 Feb 1983-Science
TL;DR: A genetic recombinant within the major histocompatibility (B) complex of the chicken has revealed the chromosomal subregion effecting resistance to Marek's disease--a malignant lymphoma induced by a herpesvirus.
Abstract: A genetic recombinant within the major histocompatibility (B) complex of the chicken has revealed the chromosomal subregion effecting resistance to Marek's disease--a malignant lymphoma induced by a herpesvirus. The recombinant, BF21-G19, occurred spontaneously among the progeny of a male heterozygous for resistant BF21-G21 and susceptible BF19-G19 haplotypes. Exposure to Marek's disease of families segregating for the recombinant showed that this new F-G arrangement conferred a level of resistance equivalent to that of the resistant parental haplotype. Thus, a gene, or genes, within or closely linked to the B-F region of the B complex appears to be responsible for the observed resistance to Marek's disease.

173 citations


Journal ArticleDOI
TL;DR: A new genus of marine methanogenic bacteria is described that utilizes trimethylamine, diethylamine (TMA-10), monomethylamines, and methanol as substrates for growth and meetinghanogenesis.
Abstract: A new genus of marine methanogenic bacteria is described that utilizes trimethylamine, diethylamine, monomethylamine, and methanol as substrates for growth and methanogenesis. Methane was not produced from H2-CO2, sodium formate, or sodium acetate. Growth on trimethylamine was stimulated by yeast extract, Trypticase (BBL Microbiology Systems, Cockeysville, Md.), rumen fluid, or B vitamins. The optimal growth temperature was 30 to 35°C. The maximum growth rate was between pH 7.0 and 7.5. Na+ (0.4 M) and MgSO4 (0.05 M) were required for maximum growth. Colonies of the type strain, TMA-10, were yellow, circular, and convex with entire edges. Cells were nonmotile, nonsporeforming, irregular cocci 1 μm in diameter which stained gram negative and occurred singly or in pairs. Micrographs of thin sections revealed a monolayered cell wall approximately 10-nm thick which consisted of protein. Cells were lysed in 0.01% sodium dodecyl sulfate or 0.001% Triton X-100. The DNA base composition was 42 mol% guanine plus cytosine. Methanococcoides is the proposed genus and Methanococcoides methylutens is the type species. TMA-10 is the type strain (ATCC 33938). Images

151 citations


Journal ArticleDOI
TL;DR: There is a strong case for supplementing breast milk given to preterm babies with the B complex vitamins, and breast milk whether from their own mother or from the milk bank may not meet their needs.
Abstract: Samples of milk were taken at intervals during lactation from 35 mothers of term and 26 mothers of preterm infants and assayed for 8 B complex vitamins. Both term and preterm milks varied widely in vitamin content between mothers. Mean concentrations of thiamin, vitamin B6, nicotinic acid, pantothenic acid, biotin, and folic acid increased progressively over several weeks after parturition but vitamin B12 concentrations declined generally and riboflavin values showed little change. Preterm milk was not richer in vitamins than term milk of the corresponding stage of lactation and it appeared that intake of B vitamins differed widely among preterm infants given their own mothers' milk. These infants may have meagre body reserves and an increased need for vitamins, and breast milk whether from their own mother or from the milk bank may not meet their needs. There is a strong case for supplementing breast milk given to preterm babies with the B complex vitamins.

65 citations


Journal Article
TL;DR: There was a non-significant trend for those subjects taking megadoses of vitamin C to have increased cell-mediated immune responses as measured in vivo by skin test reactivity but not by in vitro mitogen responses, raising the possibility that some of the previously reported immuno-enhancing properties of megadose vitamins may be due to aNon-specific adjuvant effect that disappears with time.
Abstract: We studied the immunological effects of 'megadose' vitamin or mineral supplementation by comparing the immunological functions of healthy elderly subjects taking large amounts of specific nutrients to similar subjects not on supplements. There was a non-significant trend for those subjects taking megadoses of vitamin C to have increased cell-mediated immune responses as measured in vivo by skin test reactivity but not by in vitro mitogen responses. In addition, subjects taking megadoses of vitamin E or any of several B vitamins (B1, B2, B6, folate and niacin) had lower absolute circulating lymphocyte counts than did the rest of the population. The relative lack of effect of megadose vitamins on immunological function in this population compared to reports of short term trials of mega nutrients raises the possibility that some of the previously reported immuno-enhancing properties of megadose vitamins may be due to a non-specific adjuvant effect that disappears with time.

58 citations


Journal ArticleDOI
TL;DR: The extent to which biosynthetic events in the nucleocytoplasmic compartments are coordinated with those inside the chloroplast during the de-etiolation of pea seedlings is examined by using a highly specific radioimmune assay.
Abstract: Chloroplast development involves the nucleus, the cytoplasm and the chloroplast of plant cells. This may be illustrated by reference to the two most abundant proteins of the chloroplast: (i) the soluble CO$_2$-fixing enzyme ribulose 1,5-bisphosphate carboxylase-oxygenase, whose large subunit (LSU) is encoded in chloroplast DNA and synthesized on chloroplast ribosomes and whose small subunit (SSU) is encoded in nuclear DNA, synthesized on cytoplasmic ribosomes in precursor form and transported into chloroplasts, and (ii) the thylakoid-bound light-harvesting chlorophyll a/b complex, whose pigment components are synthesized in the chloroplast and whose apoproteins resemble the SSU in site of coding and site of synthesis. We have examined the extent to which biosynthetic events in the nucleocytoplasmic compartments are coordinated with those inside the chloroplast during the de-etiolation of pea seedlings. We have examined the levels of LSU, SSU and the light-harvesting chlorophyll a/b protein (LHCP) by using a highly specific radioimmune assay. The steady-state levels of the corresponding mRNAs have been determined using specific cloned DNA probes. With the SSU, the mRNA and protein levels are near the limit of detection in dark-grown plants but increase markedly under continuous white light, with a lag of about 24 h. The protein appears to be under simple phytochrome control at the level of the steady-state concentration of its mRNA. The LSU also appears to be regulated through the steady-state concentration of its mRNA but in this case the mRNA is not under simple phytochrome control. The LHCP mRNA is readily detectable in dark-grown plants and accumulates further under illumination in a phytochrome-mediated manner. However, the LHCP itself (like chlorophyll) is not detectable in dark-grown plants and accumulates to high levels only under continuous illumination, with a lag of about 6 h. Post-translational control is particularly important in the accumulation of the LHCP: continuous chlorophyll synthesis is required for the stabilization of the protein within the thylakoid membrane, at least during the early stages of chloroplast development.

54 citations


Journal ArticleDOI
TL;DR: The data suggest that freezing and frozen storage for up to 3 months can be used to preserve mature human milk with minimum loss of its biologic activity.
Abstract: A study was initiated to evaluate the effects of several methods of processing and storage on key enzymes, B vitamins, and lipid components of mature human milk. In order to establish standard values for the nutrient components with which to compare processed samples, a total of 30 individual raw samples of mature human milk were analyzed. There was considerable sample to sample variation as indicated by the large range of values for each component. Freezing and frozen storage had little effect on the enzymes of pooled samples of milk. Lactoperoxidase activity decreased from 36 in raw pooled samples to 17 in pooled samples slow frozen and stored for 3 months at -25 degrees C (P less than 0.05). Similarly, quick freezing and storage for 3 months significantly decreased the lactoperoxidase activity of pooled samples from 93 to 14 (P less than 0.05). Quick freezing and frozen storage tended to increase lipase activity although the changes were not significant. Freezing and frozen storage did not significantly affect the levels of biotin, niacin, and folic acid. Similarly, the total lipid fatty acid level and relative % of each fatty acid were not significantly different in the frozen samples as compared to the raw samples.

50 citations


Journal ArticleDOI
TL;DR: A simple, rapid method is developed using octyl glucoside solubilization to obtain preparations from spinach and barley that are highly enriched in PS II reaction centre activity, strongly suggesting that the former is the reaction centre complex of PS II.
Abstract: Evidence is presented for the identification of the chlorophyll- protein complex CPa-1 (CP 47) as the reaction centre of photosystem II (PS II). We have developed a simple, rapid method using octyl glucoside solubilization to obtain preparations from spinach and barley that are highly enriched in PS II reaction centre activity (measured as the light-driven reduction of diphenylcarbazide by 2,6-dichlorophenolindophenol). These preparations contain only the two minor chlorophyll-protein complexes CPa-1 and CPa-2. During centrifugation on a sucrose density gradient, there is a partial separation of the two CPa complexes from each other, and a complete separation from other chlorophyll-protein complexes. The PS II activity comigrates with CPa-1 but not CPa-2, strongly suggesting that the former is the reaction centre complex of PS II. Reaction centre preparations are sensitive to the herbicide 3(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU), but only at much higher concentrations than those required to inhibit intact thylakoid membranes. A model of PS II incorporating our current knowledge of the chlorophyll-protein complexes is presented. It is proposed that CPa-2 and the chlorophyll a + b complex CP 29 may function as internal antenna complexes surrounding the reaction centre, with the addition of variable amounts of the major chlorophyll a + b light-harvesting complex.

35 citations


Journal ArticleDOI
TL;DR: Most of the B vitamins were found to be stable, however, indirect and direct sunlight destroyed 47 and 100%, respectively, of riboflavin-5-phosphate in eight hours and Direct sunlight destroyed 86% of pyridoxine HCl.
Abstract: The effects of various light conditions such as fluorescent light, and indirect and direct sunlight on the stability of the water-soluble B vitamins in parenteral mixtures were studied. The levels of the B vitamins were determined by microbiologic assays and spectrophotometrically. Most of the B vitamins were found to be stable. However, indirect and direct sunlight destroyed 47 and 100%, respectively, of riboflavin-5-phosphate in eight hours. Direct sunlight destroyed 86% of pyridoxine HCl. There was no loss of folic acid in parenteral nutrition mixtures after storage for 7 wk. The microbiologic assays were found to be reliable to measure the levels of the B vitamins in parenteral nutrition solution.

34 citations


Journal ArticleDOI
TL;DR: Vitamin status as assessed by measurement of erythrocyte transketolase (ETK), glutathione reductase (EGR) and glutamateoxaloacetate transaminasc (EGOT) activities improved in most patients by Day 5 irrespective of the treatment regime, indicating that in alcoholics, EGOT is a poor indicator of pyridoxine status.
Abstract: Ninety-seven admissions to an alcoholic unit were allocated to one of three groups receiving either oral vitamin supplements, intravenous vitamin therapy or placebo during a fiveday detoxification regime. Thiamine, riboflavin and pyridoxine status was assessed by measurement of erythrocyte transketolase (ETK), glutathione reductase (EGR) and glutamateoxaloacetate transaminasc (EGOT) activities on Days 0, 2 and 5. Vitamin status as assessed by these parameters improved in most patients by Day 5 irrespective of the treatment regime. However, two-thirds of those patients originally thiamine-deficient, as assessed by basal ETK, were still deficient after fivedays, irrespective of vitamin therapy received. Assessment of thiamine status by basal ETK yielded more patients rated as deficient than did assessment by the activation coefficient for transketolase ( a -ETK or ‘TPP effect’). EGOT was elevated in nearly all patients studied, whilst erythrocyte pyridoxal-5-phosphate concentrations were low, indicating that in alcoholics, EGOT is a poor indicator of pyridoxine status.

26 citations


Journal ArticleDOI
TL;DR: In a previous experiment on the preservation of hay of high moisture content with formic acid, among other agents, aflatoxin was formed in the hay, and a flatoxin-forming strains of Aspergillus flavus were isolated from this hay after incubation in air as well as in an anaerobic jar.
Abstract: In a previous experiment on the preservation of hay of high moisture content with formic acid, among other agents, aflatoxin was formed in the hay, and aflatoxin-forming strains of Aspergillus flavus were isolated from this hay after incubation in air as well as in an anaerobic jar One isolate from the anaerobic jar was cultivated in a chemostat (Bioflo model C 30; New Brunswick Scientific Co) in a defined medium with added B vitamins, yeast extract, or formic acid, with or without gas flow (air or nitrogen) In all cases where spore germination occurred, aflatoxin was formed in the cultures with gas flow, and small quantities of aflatoxins B1 and B2 occurred even in an atmosphere of nitrogen Addition of B vitamins and supply of traces of air gave an approximately 15-fold increase in the amount of aflatoxin in 2 days Carbon dioxide enrichment hindered aflatoxin formation on the defined medium even in the presence of B vitamins, but when formic acid was added, small quantities (5 to 15 micrograms/liter) were formed, and this low level remained constant until the gas flow was started

25 citations


Journal Article
TL;DR: It is suggested that B2 deficiency brings about metabolic disorders in the redox system to maintain lens transparency, that lipoperoxide is accumulated, and that the efficiency of the scavenging system and the activities of glutathione peroxidase and reductase are decreased.
Abstract: The level of NADPH-cytochrome c reductase, glutathione reductase and hepatic B2 was significantly decreased in rats fed a B2-deficient diet. The synthesis of ester forms of B2 was decreased more in the lenses of rats fed this diet for 8 weeks than in those fed this diet for 4 weeks. The glutathione reductase activity in the lens decreased as the duration of a B2-deficient diet increased; this may be ascribable to a decrease in the formation in the lenticular riboflavin ester as a coenzyme. The level of lipid peroxides increased in the serum and lenses of rats on the B2-deficient diet, however, compared to the controls, the changes in the activities of superoxide dismutase and glutathione S-transferase were not significant. Lenticular glutathione peroxidase activity was decreased significantly in rats fed the B2-deficient diet for 8 weeks. We suggest that B2 deficiency brings about metabolic disorders in the redox system to maintain lens transparency, that lipoperoxide is accumulated, and that the efficiency of the scavenging system and the activities of glutathione peroxidase and reductase are decreased.

Journal ArticleDOI
TL;DR: Results indicate that higher regression is associated with an interaction between the line 63 Ly-4aand Th-1aalleles in homozygous form and dominance x dominance interaction, in that the a allele at each locus is dominant for higher regression only within the Homozygous aa genotype at the other locus.
Abstract: Chickens of Regional Poultry Research Laboratory (RPRL) inbred line 63 regress sarcomas induced by Bryan high-titer Rous sarcoma virus to a greater extent than chickens of line 72, although these lines are identical for the major histocompatibility complex (MHC, B complex). They differ, however, at two independent autosomal loci, Ly-4 and Th-1, which determine surface alloantigens of partly overlapping subsets of T lymphocytes. Association of genotypes at these loci with quantitative variation in ability to regress Rous sarcomas was tested in segregating progeny derived from crosses of lines 63 and 72. In the F4 generation chickens of the Ly-4 a /Ly-4 a , Th-1 a /Th-1 a genotype (symbolized aa/aa) had significantly higher regressor ability than any of the other three double homozygous genotypes. In F5, all nine genotypes formed by combinations of homozygotes and heterozygotes were tested, and higher regressor ability was shown by the aa/aa, ab/aa, and aa/ab genotypes. These results indicate that higher regression is associated with: (1) interaction between the line 63Ly-4 a and Th-1 a alleles in homozygous form; and (2) dominance x dominance interaction, in that the a allele at each locus is dominant for higher regression only within the homozygous aa genotype at the other locus.

Journal ArticleDOI
TL;DR: It is suggested that egg yolk and egg white contain distinct R binders which could explain the differential B12 absorption from egg yolks and eggwhite.


Journal Article
TL;DR: In this study chickens were immunosuppressed by neonatal cyclophosphamide treatment or surgical bursectomy to determine the possible role of antibodies in the pathogenesis of TP.
Abstract: Marek's disease virus (MDV)3 is a highly oncogenic herpesvirus that usually causes visceral lymphomas and lymphoid infiltration of the peripheral nerves in chickens. A relatively rare encephalitic condition, first found in farm flocks and referred to as transient paralysis (TP), is also caused by MDV(1). TP symptoms occur 9 to 11 days after MDV inoculation and range from mild ataxia to profound coma. Most birds recover by 24 to 72 hr after onset of symptoms, although severely affected birds may die within the same time period. Previous studies in this laboratory (2) showed that susceptibility to TP is a recessive trait controlled by major histocompatibility complex (MHC) genes (i.e., B complex genes of chickens). Inbred line G-B1 chickens (B13/B13) are resistant to TP, whereas chickens from related inbred lines G-B2 (B6/B6) and G-B3 (B15/B15) are highly susceptible. In this study chickens were immunosuppressed by neonatal cyclophosphamide (CY) treatment or surgical bursectomy (BX) to determine the possible role of antibodies in the pathogenesis of TP.

Journal ArticleDOI
TL;DR: The molecular cloning of cDNA corresponds to pea seedling mRNA sequences encoding a shoot-specific polypeptide, the small subunit of the ribulose 1,5 biphosphate carboxylase and a component of the light-harvesting chlorophyll a/b complex is described.
Abstract: The molecular cloning of cDNA corresponds to pea seedling mRNA sequences encoding a shoot-specific polypeptide, the small subunit of the ribulose 1,5 biphosphate carboxylase and a component of the light-harvesting chlorophyll a/b complex is described. cDNA prepared from polysomal poly(A)RNA of light-grown shoots was enriched for shoot-specific and light-induced sequences by heterologous liquid hybridization with mercurated polysomal poly(A)RNA of dark-grown roots, followed by sulfhydryl chromatography. Cloned shoot-specific sequences were identified by 2D electrophoretic analysis of hybrid release translation products. The cloned shoot-specific sequence corresponded to a mRNA of 850 nt present both in light-and dark-grown shoots, and produced anin vitro translation product of Mr27 500 and isoelectric point of 4.7.

Journal ArticleDOI
TL;DR: The results demonstrate that these B complex-linked genes, controlling tumor expression, belong to a multiple allelic series, confirming the findings of others that tumor regression is controlled by genes linked to the B complex.

Journal ArticleDOI
TL;DR: Six strains of yeasts were isolated from P. semipunctata larval gut in order to determine their role in insects nutrition, and β-Glucosidase was secreted in the medium by all strains except one.
Abstract: Six strains of yeasts were isolated from P. semipunctata larval gut in order to determine their role in insects nutrition. P. semipunctata larvae possess a rich glycosidasic equipment acting on oligosaccharides, heterosides and polysaccharides which is particularly characterized by an activity on hemicellulose. The yeast strains hydrolyze oligosaccharides, heterosides and some polysaccharides, such as starch and pectin, but no activity was detected on cellulose. β-Glucosidase was secreted in the medium by all strains except one. B group vitamins were also secreted by the yeasts.

Journal ArticleDOI
TL;DR: The effects of freeze-drying, pasteurization, high-temperature heating and storage on key enzymes, B-vitamins and lipids of pooled mature human milk were determined and there were no significant differences in lipid components following processing and storage.

Journal ArticleDOI
01 Jul 1983
TL;DR: Tempeh samples produced from cowpeas and soy beans were analysed for vitamin B2 (riboflavin), B6 (pyridoxine), B12 (cyanocobalamin), niacin, and Pantothenic acid.
Abstract: Tempeh samples produced from cowpeas and soy beans were analysed forvitamin B2 (riboflavin), B6 (pyridoxine), B12 (cyanocobalamin), niacin, andpantothenic acid. Vitamin contents increased significa...

Book ChapterDOI
TL;DR: Clear-cut correlations between the magnitude of dietary deficiency and the prevalence of signs and symptoms of vitamin deficiency were not apparent in the comparisons between populations, suggesting that as well as dietary deficiency other environmental factors play a role in the development of clinical deficiency.
Abstract: Rice is the staple food in many countries of Asia Recent nutrition surveys in eight states, conducted by the National Nutrition Monitoring Bureau of India, show that though the average energy intake is adequate, more than 50% of the households surveyed consumed less than the Recommended Dietary Allowance (RDA) of energy These households generally had per capita incomes of less than Rupees 2/- (US$ 025) per day The average intake of vitamin A was only 42% of the RDA and that of riboflavin, 70% of the RDA The average intake of other nutrients such as thiamin, niacin, ascorbic acid, iron and calcium was adequate, although thiamin deficiency was present in populations where rice was the main cereal, but not in populations that consumed mixed cereal or cereal-millet diets The magnitude of the riboflavin deficiency (after correction for energy) was also more marked in the former Vitamin A intake was not related to the type of cereal, but had some relationship to the quantity of vegetables consumed

Journal ArticleDOI
TL;DR: The highly significant difference between the combined GAT‐hi and ‐lo groups would suggest that the Rs locus controlling tumour regression induced by the subgroup C virus is closely linked to the region controlling immune response to GAT, but the data also provides evidence that the B‐F region of the B complex also plays an important role in RSV‐induced tumours regression.
Abstract: Two B complex genotypes, B1B1 and B19B19, of outbred line S1, were tested for low and high immune response to GAT, from which four recombinants were recovered: B1B1 GAT-hi and -lo, and B19B19 GAT-hi and -lo. Also included in the study were birds of B2B2 genotype with an intermediate level of immune response to GAT. A total of 225 birds of these groups were challenged with the Bryan strain of Rous Sarcoma virus subgroup C, RSV (RAV-7), by inoculation into the wing web at five weeks of age. The B1B1 genotype had the lowest percentage of regressors (17.6%), B19B19 had the highest (42.2%), and the B2B2 genotype was intermediate (23.7%). Combining the results of GAT response over the B1B1 and B19B19 genotypes, 14.0% of GAT-lo and 37.8% of GAT-hi regressed their tumours, respectively. The highly significant (P less than or equal to 0.01) difference between the combined GAT-hi and -lo groups would suggest that the Rs locus controlling tumour regression induced by the subgroup C virus is closely linked to the region controlling immune response to GAT, but the data also provides evidence that the B-F region of the B complex also plays an important role in RSV-induced tumour regression.

Journal Article
TL;DR: This paper focuses on a member of the B complex, vitamin B6, reviewing its biochemical functions, associated disease states, and laboratory evaluation.
Abstract: A wealth of information has accumulated over the past several decades with respect to the B-complex vitamins and their roles in health and disease. This paper focuses on a member of the B complex, vitamin B6, reviewing its biochemical functions, associated disease states, and laboratory evaluation.

Journal ArticleDOI
TL;DR: It is suggested that 2-n-heptyl-4-hydroxyquinoline-N-oxide binds in a region of the Q/B complex that is distinct from the 3-(3,4-dichloro)-1,1-dimethyl urea and atrazine binding sites.
Abstract: The effects of 2-n-heptyl-4-hydroxyquinoline-N-oxide on electron transport in thylakoids and oxygen-evolving photosystem II particles has been examined. Kinetic fluorescence studies reveal that the site of inhibition for alkyl derivatives of hydroxyquinoline-N-oxide (I50℞2 µM) is located between Q and plastoquinone. Studies with thylakoids isolated from atrazine-resistant pigweed plants indicate that the modification in the Q/B membrane complex that confers increased resistance to inhibition by atrazine also results in decreased sensitivity to inhibition by 2-n-heptyl-4-hydroxyquinoline-N-oxide (resistant/sensitive ratio =11). From the results of tetramethylphenylenediamine by-pass experiments, determinations of inhibitor sensitivity in trypsin-treated thylakoids and competitive displacement experiments made with [14C]metribuzin in thylakoids and photosystem II particles, it is suggested that 2-n-heptyl-4-hydroxyquinoline-N-oxide binds in a region of the Q/B complex that is distinct from the 3-(3,4-dichloro)-1,1-dimethyl urea and atrazine binding sites.

Journal ArticleDOI
TL;DR: Germination on agar and pathogenicity to eggplant, potato and tomato of microsclerotia of Verticillium dahliae was affected by host origin and growth medium and the addition of β -group vitamins to the substrate for sclerotial production increased both germinability and pathogensicity.
Abstract: Germination on agar and pathogenicity to eggplant, potato and tomato of microsclerotia of Verticillium dahliae was affected by host origin and growth medium. Microsclerotia were most pathogenic to plants on which they had been produced. Microsclerotia cultured on eggplant stems germinated less than those cultured on potato, tomato or synthetic medium. The addition of β -group vitamins to the substrate for sclerotial production increased both germinability and pathogenicity. Germination of microsclerotia from stem segments was similar to that obtained on media containing their extracts. Increasing the glucose concentration to 2 % improved pathogenicity, germination and the number of hyphae emerging from every microsclerotium. Increasing the nitrogen level to 1 % also increased pathogenicity. Any further addition of nitrogen reduced both pathogenicity and germination. At a level of 5 % nitrogen no microsclerotia were produced.


Journal ArticleDOI
TL;DR: In this paper, the results of a competition between iron(III) and the proton for the hydroxamate oxygen were discussed in terms of the equilibrium quotient for the formation of diferrioxamine B complex, which was calculated as being (2.7 ± 0.3) × 10 5 mol L −1.

Journal ArticleDOI
01 Dec 1983-Botany
TL;DR: The nutritional requirements of a unique predatory fungus isolated from forest soil and has an absolute requirement for histidine and methionine with a partial requirement for several other amino acids are described.
Abstract: The nutritional requirements of a unique predatory fungus are described. The strain of Arthrobotrys dactyloides was isolated from forest soil and has an absolute requirement for histidine and methionine with a partial requirement for several other amino acids. In common with many other fungi it requires glucose and one or more of the B vitamins.

Journal ArticleDOI
TL;DR: In this paper, it was shown that electron transport in thylakoids and particles is equally sensitive to inhibition by DCMU vs. HQNO or DBMIB, and when synthetic quinones, e.g. 5,6-methylenedioxy-2,3-dimethyl benzoquinone act as autoxidizable acceptors they accept electron from the Q/B complex at a point that is located between the DCMU and HQNO (DBMIB) inhibition sites.
Abstract: Photosystem II particles that retain the ability to evolve O₂ have been used to examine acceptor and inhibitor sites in the photosynthetic electron transfer chain between Q and plastoquinone. Employing the water to dichlorobenzoquinone reaction to assay photosystem II activity, we have demonstrated that electron transport in thylakoids and particles is equally sensitive to inhibition by DCMU. dinoseb, metribuzin, HQNO and DBMIB. Based on differential sensitivity to inhibition by DCMU vs. HQNO or DBMIB, we suggest that when synthetic quinones, e.g. 2,6-dichlorobenzoquinone operate as Hill reagents in particles they are reduced primarily by the plastoquinone pool. When synthetic quinones, e.g. 5,6-methylenedioxy-2,3-dimethyl benzoquinone act as autoxidizable acceptors they accept electron from the Q/B complex at a point that is located between the DCMU and HQNO (DBMIB) inhibition sites.

Journal ArticleDOI
01 Jan 1983
TL;DR: A prospective study of light-to-moderate drinkers was undertaken to establish the frequency of abnormal findings on CT, psychometric and dietary parameters over a range of alcohol consumption, and to exclude the possibility of poor nutrition contributing to the picture of CT atrophy.
Abstract: A prospective study of light-to-moderate drinkers was undertaken to establish the frequency of abnormal findings on CT, psychometric and dietary parameters over a range of alcohol consumption. In particular, it was desirable to exclude the possibility of poor nutrition contributing to the picture of CT atrophy, especially with the assessment of any demonstrable reversibility. Thirty-nine subjects were studied and 16 were found to be deficient in some part of their diet, although initial interviews established that they considered they took a balanced, adequate diet. Five subjects were re-examined after six months' abstinence from alcohol: in four cases the total kilocalorie intake was less than the initial total, a proportion having been contributed latter by the previous alcohol consumption. The dietary history was partially checked by estimation of the level of B vitamins. Seven subjects had a low red cell thiamin, four of these having a normal serum level. These findings in social drinkers (mean alcoho...