scispace - formally typeset
Search or ask a question

Showing papers on "B vitamins published in 1981"


Journal ArticleDOI
TL;DR: It is concluded that the newly synthesized light-harvesting chlorophyll a/b protein fail to accumulate in intermittently illuminated leaves because they undergo rapid turnover.
Abstract: 1 Antibodies raised against the 26000-Mr polypeptides of the light-harvesting chlorophyll a/b proteins of pea leaves specifically immunoprecipitated two 32000 -Mr polypeptides synthesized when pea leaf poly(A)-containing RNA was translated in vitro. On the basis of immunochemical relatedness and by comparison of their partial tryptic digestion products, the 32000 -Mr products formed in vitro are identified as precursors to the authentic polypeptides of the light-harvesting chlorophyll a/b complex. 2 The specificity of the immunoprecipitation permitted the development of an assay for the cellular levels of translationally active light-harvesting protein mRNA in plants exposed to different light regimes. Low levels of the mRNAs were detectable in dark-grown plants. Exposure to continuous illumination caused these levels to increase by at least ten-fold and led to the appearance of large quantities of the light-harvesting chlorophyll a/b complex. In plants exposed to intermittent illumination (2 min of white light every 2 h for 2 days), the light-harvesting complex did not accumulate, although levels of mRNA specifying the polypeptides of the complex were high (50% of those in continuously illuminated plants). 3 Messenger RNAs encoding the light-harvesting proteins were detected in polysomes of intermittently illuminated leaves. These polysomes were active in a wheat-germ 100000 ×g supernatant ‘run-off’ system, to form light-harvesting protein precursors, under conditions when only nascent polypeptide chains initiated in vivo were elongated and terminated. These results demonstrate that the inability of intermittently illuminated leaves to accumulate the light-harvesting proteins is not due to a selective inhibition of the translation of the corresponding mRNAs. 4 Intermittently illuminated leaves were labelled with [35S]methionine in darkness, and incorporation of radioisotope into the light-harvesting proteins and their precursors was assayed immunologically. No pool of untransported or unprocessed 32000 -Mr precursor polypeptides could be detected in the soluble fraction (cytoplasm and stroma). However, low levels of the mature 26000 -Mr polypeptides were detected in the membrane fraction. It is concluded that the newly synthesized light-harvesting chlorophyll a/b proteins fail to accumulate in intermittently illuminated leaves because they undergo rapid turnover. The site of light-harvesting protein breakdown is probably the thylakoid membrane, and the cause of breakdown is probably the absence of chlorophyll a and chlorophyll b molecules that are required for eventual stabilization of the proteins within the photosynthetic membrane.

269 citations


Journal ArticleDOI
TL;DR: From the identical pattern of susceptibility to trypsin it is concluded that the rapidly synthesized 34-kilodalton polypeptide that is a product of chloroplast-directed protein synthesis is identical to the triazine herbicide-binding protein of photosystem II.
Abstract: The triazine herbicides inhibit photosynthesis by blocking electron transport at the second stable electron acceptor of photosystem II. This electron transport component of chloroplast thylakoid membranes is a protein-plastoquinone complex termed “B.” The polypeptide that is believed to be a component of the B complex has recently been identified as a 32- to 34-kilo-dalton polypeptide by using a photoaffinity labeling probe, azido-[14C]atrazine. A 34-kilodalton polypeptide of pea chloroplasts rapidly incorporates [35S]methionine in vivo and is also a rapidly labeled product of chloroplast-directed protein synthesis. Trypsin treatment of membranes tagged with azido-[14C]atrazine, [35S]methionine in vivo, or [35S]methionine in isolated intact chloroplasts results in identical, sequential alterations of the 34-kilo-dalton polypeptide to species of 32, then 18 and 16 kilodaltons. From the identical pattern of susceptibility to trypsin we conclude that the rapidly synthesized 34-kilodalton polypeptide that is a product of chloroplast-directed protein synthesis is identical to the triazine herbicide-binding protein of photosystem II. Chloroplasts of both triazine-susceptible and triazine-resistant biotypes of Amaranthus hybridus synthesize the 34-kilodalton polypeptide, but that of the resistant biotype does not bind the herbicide.

149 citations


Journal ArticleDOI
TL;DR: It is concluded that the newly synthesized light-harvesting chlorophyll a/b protein fail to accumulate in intermittently illuminated leaves because they undergo rapid turnover.
Abstract: 1 Antibodies raised against the 26000-Mr polypeptides of the light-harvesting chlorophyll a/b proteins of pea leaves specifically immunoprecipitated two 32000-Mr polypeptides synthesized when pea leaf poly(A)-containing RNA was translated in vitro On the basis of immunochemical relatedness and by comparison of their partial tryptic digestion products, the 32000-Mr products formed in vitro are identified as precursors to the authentic polypeptides of the light-harvesting chlorophyll a/b complex 2 The specificity of the immunoprecipitation permitted the development of an assay for the cellular levels of translationally active light-harvesting protein mRNA in plants exposed to different light regimes Low levels of the mRNAs were detectable in dark-grown plants Exposure to continuous illumination caused these levels to increase by at least ten-fold and led to the appearance of large quantities of the light-harvesting chlorophyll a/b complex In plants exposed to intermittent illumination (2 min of white light every 2 h for 2 days), the light-harvesting complex did not accumulate, although levels of mRNA specifying the polypeptides of the complex were high (50% of those in continuously illuminated plants) 3 Messenger RNAs encoding the light-harvesting proteins were detected in polysomes of intermittently illuminated leaves These polysomes were active in a wheat-germ 100 000 X g supernatant "run-off" system, to form light-harvesting protein precursors, under conditions when only nascent polypeptide chains initiated in vivo were elongated and terminated These results demonstrate that the inability of intermittently illuminated leaves to accumulate the light-harvesting proteins is not due to a selective inhibition of the translation of the corresponding mRNAs 4 Intermittently illuminated leaves were labelled with [35S]methionine in darkness, and incorporation of radioisotope into the light-harvesting proteins and their precursors was assayed immunologically No pool of untransported or unprocessed 32000-Mr precursor polypeptides could be detected in the soluble fraction (cytoplasm and stroma) However, low levels of the mature 26000-Mr polypeptides were detected in the membrane fraction It is concluded that the newly synthesized light-harvesting chlorophyll a/b protein fail to accumulate in intermittently illuminated leaves because they undergo rapid turnover The site of light-harvesting protein breakdown is probably the thylakoid membrane, and the cause of breakdown is probably the absence of chlorophyll a and chlorophyll b molecules that are required for eventual stabilization of the proteins within the photosynthetic membrane

98 citations


Journal Article
TL;DR: This preliminary study finds that the existence of therapeutically cross-reacting homologous catalyst and substrate deficiency forms of pellagra are postulated, the first contributing to the B vitamin deficiency epidemics of 50-100 years ago, the second to the more recent endemic "Diseases of Western Civilization" which express in certain genetic subgroups as the major mental illnesses of today.

90 citations


Journal ArticleDOI
TL;DR: A number of functional similarities exist between the chicken MHC and that of other species such as regulation of graft rejection, graft‐versus‐host reaction (GVHR) and mixed lymphocyte reactions (MLR), mitogenic and immune responsiveness and resistance to RNA and DNA virus infection.
Abstract: The chicken MHC (B complex) initially described by Briles as controlling blood antigens, is now known to be composed of at least three regions, L, F and G. Two of these, F and G, were described on the basis of recombinants found in a study of over 10,000 chickens. On the basis of biochemical, tissue distribution and functional analyses, F corresponds to the murine H-2 K/D regions. The G region is unique to the chicken since the antigenic product is expressed only on erythrocytes and their progenitors. L was identified by serological studies and corresponds to the H-2 I region; the L antigen is expressed predominantly on B lymphocytes, monocytes and 10% of T lymphocytes, and differences in the L region result in variations in immune responsiveness. A number of functional similarities exist between the chicken MHC and that of other species such as regulation of graft rejection, graft-versus-host reaction (GVHR) and mixed lymphocyte reactions (MLR), mitogenic and immune responsiveness and resistance to RNA and DNA virus infection. The chicken MHC also controls the severity of autoimmune disease, as exemplified by the spontaneous thyroiditis of Obese strain (OS) chickens. It differs from mammalian MHC's by having of lower crossing-over frequency and no apparent gene duplication.

79 citations


Journal ArticleDOI
TL;DR: It is proposed that the mitochondrial defect is situated between NADH dehydrogenase and the CoQ--Cytochrome b complex; possibly being a derangement of a non-haem iron sulphur centre.

54 citations


Journal ArticleDOI
TL;DR: It is concluded that B‐L antigens of the chicken exhibit extensive homology with mammalian la antIGens.
Abstract: This paper reviews the present knowledge of B-L antigens encoded by the chicken B complex as regards to the following aspects: (1) identification and cellular expression, (2) structural studies, (3) evidence for two distinct populations of B-L antigens, (4) mapping of B-L loci of the B complex, (5) B-L and immune response, and (6) the role of the B-L antigens for the control of mixed lymphocyte reactions (MLR) and graft-versus-host (GVH) reactions. It is concluded that B-L antigens of the chicken exhibit extensive homology with mammalian Ia antigens. A genetic map of the B complex is presented.

38 citations


Journal Article
TL;DR: Results suggest that the gene responsible for Rous sarcoma regression is located in the B-F region of the B complex in inbred chicken lines CB, CC and CB.R1.
Abstract: We studied the fate of tumours induced by PR-RSV-C and B77-C in inbred chicken lines CB, CC and CB.R1. Rous sarcomas regressed in the CB and CB.R1 lines which are identical in the B-F region of the B complex. In contrast, progressive tumour growth was observed in the CC line which differed in the B-F region from the CB and CB.R1 lines and was identical in the B-G region with the CB.R1 line. These results suggest that the gene responsible for Rous sarcoma regression is located in the B-F region of the B complex.

37 citations


Journal ArticleDOI
TL;DR: In this article, the authors found that resistance of susceptibility to Marek's disease in chickens was associated with immune response to the amino acid polymer GAT, and that both B1 B1 and B19 B19 GAT low responders had significantly higher incidence of MD than the B 1 B 1 and B 19 B 19 GAT high responder counterparts.

37 citations


Journal ArticleDOI
TL;DR: In spite of the absence of genetic evidence for more than one B-L locus in the chicken B complex, it was shown by sequential antibody incubations that these two different B- l antigenic determinants are associated with at least two separate species of B- L molecules, indicating the presence of at leastTwo B-l loci within the MHC of the chicken.
Abstract: Two specific alloantisera detecting B-L (Ia-like) antigens on chicken lymphocytes of the B6 and B15 haplotypes were found to cross-react strongly. Anti-B-L6 and anti-B-L15 alloantisera both reacted with B-L molecules on B6 and B15 lymphocytes as demonstrated by immunofluorescence and SDS-PAGE analysis of 125I-labeled B-L antigens isolated by incubation with anti-B-L alloantisera. Absorption studies showed that the anti-B-L alloantisera reacted with at least two kinds of antigenic determinant, one set shared by B-L6 and B-L15 molecules and another set specific for each haplotype. In spite of the absence of genetic evidence for more than one B-L locus in the chicken B complex, it was shown by sequential antibody incubations that these two different B-L antigenic determinants are associated with at least two separate species of B-L molecules, indicating the presence of at least two B-L loci within the MHC of the chicken.

35 citations


Journal ArticleDOI
TL;DR: Serum IgG (7S) levels differed significantly for chickens from 10 different inbred lines, and within lines differences between B blood groups were statistically significant.
Abstract: SUMMARY Serum IgG (7S) levels differed significantly for chickens from 10 different inbred lines. Within lines differences between B blood groups were statistically significant. The genetic control of serum IgG was further examined using birds from B complex haplotypes marked at the B locus and the Ir-GAT locus. Birds from each of five subgroup haplotypes (B1B1Ir-GAT-Lo and -Hi, B19B19Ir-GAT-Lo and -Hi, and B2B2Ir-GAT intermediate) were tested for levels of serum IgG at 3, 6, 9, and 21 weeks of age. The rate and level of IgG reached in the serum was more than two-fold greater in the GAT-Hi birds than in the GAT-Lo. The Ir region of the B complex exerts some control over the ontogenesis of IgG, though most of the genetic variation seems not to be B complex associated.

Journal Article
TL;DR: A series of 52 patients with scotomas attributed to tobacco smoking, alcohol consumption, and nutritional deficits--alone and in combination--was reviewed, suggesting that use of tobacco alone can produce a scotoma.
Abstract: A series of 52 patients with scotomas attributed to tobacco smoking, alcohol consumption, and nutritional deficits--alone and in combination--was reviewed. Whether use of tobacco alone can produce a scotoma has been a controversial point; our series suggests that it can. Central and cecocentral scotomas did occur in association with smoking alone; there seems to be an association between cecocentral scotoma and cigar smoking especially. Central scotomas were seen more often in patients who consumed alcohol. Recovery from either type of scotoma was observed in 3 months when a therapeutic program of abstinence and B vitamins was followed. Although the number of patients we see with these scotomas has decreased, clinicians are urged to be aware of this disorder.

Journal ArticleDOI
TL;DR: The activities of the red blood cell enzymes transketolase, glutathione reductase, and glutamic oxaloacetate transaminase were measured with and without in vitro addition of their respective coenzyme components thiamine, riboflavin, and pyridoxine in a group of patients with neurological disorders which may have been caused by malnutrition, intestinal malabsorption, hepatic failure or neoplasms arising outside the nervous system.
Abstract: The activities of the red blood cell enzymes transketolase, glutathione reductase, and glutamic oxaloacetate transaminase were measured with and without in vitro addition of their respective coenzyme components thiamine, riboflavin, and pyridoxine in a group of patients with neurological disorders which may have been caused by malnutrition, intestinal malabsorption, hepatic failure or neoplasms arising outside the nervous system. The incidence of thiamine deficiency was 31%, of riboflavin deficiency 22% and of pyridoxine deficiency 6%. Alcoholics in particular suffered from deficiencies of vitamin B 1, and B 2. There was a correlation of vitamin B 1 and B 2 deficiency and signs of a cerebellar and/or brainstem lesion. The most frequent symptoms in this connection were gait disturbances and oculomotor signs like spontaneous and gaze nystagmus, disturbed eye tracking, diminished optokinetic nystagmus, decreased ability to suppress vestibular nystagmus by fixation. These signs hardly ever occurred in alcoholic patients who showed no deficiency of vitamin B 1, B 2 or B 6. Whenever they do appear, a vitamin B supplementation has to be performed in order to prevent the manifestation of Wernicke's encephalopathy, cerebral or cerebellar atrophy. Alcoholics showed the same incidence of polyneuropathy, whether they suffered from a deficiency of B vitamins or not. Deficiencies of vitamin B 1, B 2 or B 6 were also found in patients with intestinal malabsorption and polyneuropathy, diabetic polyneuropathy, optic atrophy, myelopathy and cerebellar ataxia of unknown etiology, neurological manifestations of neoplasms arising outside the nervous system, B 12 myeloencephalopathy and Thevenard's syndrome.

Book ChapterDOI
TL;DR: Investigation on the mode of action of pyridoxine and pantothenic acid have demonstrated a marked reduction in the production of antibody-forming cells following antigenic stimulation in both deficiency states, suggesting these two vitamins seem to function at different loci in the development of the immune process.
Abstract: Studies conducted in our laboratory relating to the development of immune processes in B vitamin deficiency states of experimental animals have been reviewed. 1. The significant participation of certain of these nutritional factors in the production of circulating antibodies to a variety of antigens and the manifestation of delayed hypersensitivity reactions, including the rejection of tissue transplants, have been described. 2. Investigations on the mode of action of pyridoxine and pantothenic acid have demonstrated a marked reduction in the production of antibody-forming cells following antigenic stimulation in both deficiency states. The metabolism of antigen appeared to be normal. However, these two vitamins seem to function at different loci in the development of the immune process. Whereas pyridoxine appears to be necessary for the production of "C1" units from serine which are required for the biosynthesis of nucleic acids, it seems likely that pantothenic acid is involved in the secretion of newly-synthesized proteins into the extracellular compartment.

Journal ArticleDOI
TL;DR: It is suggested that in vivo LHCs do not form such aggregates as in water solution without a detergent, and for the LHC monomer it reaches practically the same value as for Chl a in detergent micelles.

Journal ArticleDOI
TL;DR: The editors of this volume have asked me to describe the landmark discoveries that have led to the prominence of Saccharomyces cerevisiae 1 as a eukaryotic organism of choice for a number of problems in molecular genetics.
Abstract: The editors of this volume have asked me to describe the landmark discoveries that have led to the prominence of Saccharomyces cerevisiae 1 as a eukaryotic organism of choice for a number of problems in molecular genetics To place the beginnings of yeast genetics in proper perspective, it should be recalled that at the time that O Winge was beginning his researches with yeast in the mid-thirties, the principal organisms then in use were Drosophila, corn, and Neurospora The dazzling successes of the prokaryotic era were more than a decade away Yeast was already well known as an important tool in biochemical research The interest in yeast stemmed at first from its role in alcohol production in the making of wine and beer Early in this century, when it was found that alcoholic fermentation could be carried out by an extract from yeast, the fractionation of the extract led to the discovery and characerization of enzymes and coenzymes The glycolytic pathway—the breakdown of glucose as a result of the fermentation process—was worked out in detail The individual enzymes, their specific coenzymes, and the products formed at each step of the pathway were identified As a rich source of the water-soluble B complex, yeast also was a principal contributor to early research in vitamins Thus, many of the important concepts of biochemistry owe their origins to investigations in which yeast played a key role The reemergence of yeast as an important organism in biochemical research is described in a review

Journal ArticleDOI
TL;DR: The composition and formulation of an artificial medium and handling techniques are described for rearing the chalcid insect endoparasite, Brachymeria lasus (Walker) from the egg to adult stage under in vitro conditions.

Journal ArticleDOI
TL;DR: The results proved that the IR region, as specifically defined by recombinants obtained in the S1 line of Leghorns, plays a significant, but minor, role in the GVH reaction compared with the region of the B complex identified with the B blood-group locus.
Abstract: The relative importance of the B and IR regions of the chicken B complex were compared as to their role in the graft-versus-host (GVH) reaction. Spleen enlargement (splenomegaly) on 19-day-old embryos, inoculated 5 days earlier with immune competent leukocytes, served as the test for the GVH reaction. The B blood group locus was the marker of the “B” region, and the Ir-GAT gene was the marker of the immune response (Ir) region of the B complex, the major histocompatibility system (MHS) of chickens. The test stocks consisted of B1B1 GAT-Low (1-Low) and B19B19 Gat-High (19-High) birds of our S1 Leghorn line plus the recombinant genotypes B1B1 Gat-High (1-High) and B19B19 GAT-low (19-Low). A dosage of 0.1 ml of donor white blood cells was injected into each of 191 recipient embryos on day 14, and the spleens were removed and weighed on day 19. Of 16 combinations of (donor blood)-(host embryos), arranged with respect to the four genotypes listed above, four were compatible, e. g., (1-Low)-(1-Low). There were four incompatible combinations at the B locus, four at the GAT locus, and four at both the B and GAT loci. All 16 combinations were replicated. Results were expressed as a splenomegaly index (SI), that is, the ratio of incompatible to compatible spleen weights corrected for differences in embryo weight. If (SI-1) is greater than 0, the GVH reaction is considered positive within sampling errors. The mean (SI-1) indexes obtained were: incompatible at GAT-0.5±0.07; incompatible at B-1.34±0.10. Thus, both GAT and B contributed to the GVH reaction, but the B region was much stronger than the IR region. The results were strongly asymmetrical: maximal stimulation occurred when the host embryo was B19B19 GAT-high and donor leukocytes were B1B1 GAT-Low. The parental donor-host paired combinations gave stronger GVH reactions than did the recombinant pairs. Effects of incompatibilities at the two regions proved additive when compared with two-locus differences of parental genotypes. In general, the results proved that the IR region, as specifically defined by recombinants obtained in our S1 line of Leghorns, plays a significant, but minor, role in the GVH reaction compared with the region of the B complex identified with the B blood-group locus.

Journal ArticleDOI
TL;DR: In this article, the authors divided commercially harvested blackeyed peas (cultivar Crimson) into lots soaked 3hr in 3 buffers (citrate, phosphate, bicarbonate) at 4 pH's (4.5, 5, 5.5), with and without added ethylenediaminetetracetate (EDTA).
Abstract: Commercially harvested blackeyed peas (cultivar Crimson) were divided into lots soaked 3 hr in 3 buffers (citrate, phosphate, bicarbonate) at 4 pH's (4.5, 5.5, 7.0, 8.5) with and without added ethylenediaminetetracetate (EDTA). Soaked peas were cooked by boiling and steaming. Vitamins, including pantothenic acid, niacin, and folacin, were more consistently stable to bicarbonate buffer, and were not affected by EDTA. None of the buffers showed a consistently negative effect on all vitamins lost. Soaking in phosphate and citrate buffers, especially at pH 4.5, decreased discoloration. Steam cooking retained more B-vitamins in peas, while boiling resulted in more tender peas. Soaking peas in buffers prior to pre-cooking reduced the time required for cooking.

Journal Article
TL;DR: Comparison of the content of vitamins C, B1, B2, PP, folic acid and carotene in unicellular algae and higher plants demonstrated that the above green and blue-green algae contain greater than higher plants amounts of thiamine, riboflavine, folics acid andCarotene, when calculated per g dry matter.
Abstract: The vitamin composition of representatives of green (Chlorella vulgaris, Platimonas viridis), blue-green (Synechococcus elongatus, Coccopedia, Spirulina platensis, Cyanidium caldarium), red (Porphyridium cruentum) unicellular algae and higher plants (wheat, chufa, beet, carrot, turnip, radish, cucumber, dill, Welsh onion, potato) grown under artificial conditions was examined. The content of B complex vitamins (thiamine, riboflavine, nicotinic and folic acids), ascorbic acid and carotene was measured. Among the algae studied Chlorella vulgaris and Spirulina platensis showed the highest vitamin activity. The red alga Porphyridium cruentum contained the lowest quantity of thiamine, riboflavine and carotene and larger amounts of nicotinic acid. Comparison of the content of vitamins C, B1, B2, PP, folic acid and carotene in unicellular algae and higher plants, that are natural and traditional sources of the vitamins, demonstrated that the above green and blue-green algae contain greater than higher plants amounts of thiamine, riboflavine, folic acid and carotene, when calculated per g dry matter. All algae, except for Platimonas viridis and Cyanidium caldarium, are superior to beet and carrot in their content of ascorbic acid and inferior to green vegetables (radish, cabbage, dill and Welsh onion) in that parameter.

Journal Article
TL;DR: The results demonstrated that Rous sarcoma regression in congenic CB and CC lines was controlled by a gene within the B region of the chromosome.
Abstract: The fate of tumours induced by PR-RSV-C was investigated in highly inbred chicken lines congenic at the B complex, the major histocompatibility complex of the chicken. The results demonstrated that Rous sarcoma regression in congenic CB and CC lines was controlled by a gene within the B region of the chromosome. Another congenic pair of the WA and WB lines also differed in the ability to regress RSV-induced tumours and a gene within the B complex also appeared to have a significant role in the regression of Rous sarcomas.

Journal ArticleDOI
TL;DR: Mouse-immunoglobulin (MIg) tolerant rabbits immunized with mouse H-2 antibodies produced anti-idiotype antisera, which were reactive towards specific B- and T-cell receptors.
Abstract: Mouse-immunoglobulin (MIg) tolerant rabbits immunized with mouse H-2 antibodies produced anti-idiotype antisera, which were reactive towards specific B- and T-cell receptors. One such rabbit antiserum (from rabbit 5936) defines a family of idiotypes (Id) designated 5936-idiotypes (Rubin et al. 1979). The present experiments were performed in order to establish (1) the nature of 5936-Id+ serum molecules, (2) the specificity of 5936-Id+ serum molecules, (3) the association of the 5936-Id genes to allotype and/orH-2 genes and (4) the immunological role of 5936-Id+ serum molecules. A sensitive, radioimmunoassay employing125I-labelled-F(ab)2 fragments of B6 anti-B10.BR MIg pool, 5936 antiserum, and a sheep anti-rabbit immunoglobulin antiserum, was used.—The results suggested that 5936-Id+ serum molecules were exclusively MIg, and that they were mainly of the IgG1 class. Such molecules were induced in B6 mice (H-2 b /Ig-1 b ) upon immunization with H-2k but not with H-2q alloantigen or conventional antigens. The 5936-Id were found to be associated with Ig-1b allotypes and theH-2 b complex may contain immune response (Ir) genes which, in comparison withIr genes inH-2 d andH-2 s , favor the expression of 5936-Id.—Adsorption of 5936-Id+ B6 anti-CBA MIg preparations on CBA (IAk) spleen cells demonstrated that CBA antibodies were 5936-Id−. It is dicussed whether 5936-Id+, IgG1 molecules in B6 anti-CBA sera are anti-(anti-CBA) antibodies or nonspecific antibodies, the production of which is augmented by immunization with IAk alloantigen.

Journal ArticleDOI
TL;DR: It was found that tolerance was more easily inducible in male than in female B10.A mice and that antigens determined by theD region of theH-2b complex were most easily overcome and tolerance to the products of theD end of the H-2 complex was also easy to induce.
Abstract: Neonatal transplantation tolerance to the products of theH-2 b complex was induced in B10.A (H-2 a ) mice. On the basis of the survival of skin allografts it was found that antigens determined by theD region of theH-2 b complex (of the B10.A(2R) strain) were most easily overcome and that tolerance to the products of theD end of theH-2 complex (of the B10.A(4R) strain) was also easy to induce. The antigens produced by theK end ofH-2 (of the B10.A(5R) and B10.A(3R) strains) represented a stronger incompatibility barrier and a difference in the entireH-2 b complex caused strongest resistance to tolerance induction. When tolerance to the products of the entireH-2 b complex was induced in newborn B10.A mice, and the neonatally treated animals were grafted simultaneously with five different grafts, those disparate at theK end ofH-2 and in the entireH-2 region were rejected in some animals, while the grafts disparate at theD end of H-2 remained intact in the same mice. No dependence on theI-J subregion was observed in this system. Furthermore, tolerance was more easily inducible in male than in female B10.A mice.

Journal ArticleDOI
TL;DR: In other fetal organs which contain no estrogen receptors (heart) or very low levels (lung) the concentration of site B is found to be significantly lower than in the fetal uterus, and in comparison to fetal uterus a progressive decrease is observed in the levels of both site B and estrogen receptor in neonatal, immature and adult uteri.

Journal ArticleDOI
TL;DR: The data indicated that AFB1 interfered with the metabolism of B vitamins and amino acids in rabbits and caused weight loss and anorexia in rabbits.
Abstract: The dosages of aflatoxin B1 (AFB1) required to produce significant changes in concentrations of B vitamins in plasma and bile and of amino acids in plasma of rabbits were determined. Folate increased by 98% in plasma, whereas concentration of thiamine, vitamin B6, and biotin decreased by more than 50%. In bile, choline and biotin increased 14- and 18-fold, respectively, whereas folate and niacin decreased by more than 50%. All amino acids in plasma increased between 76 and 155%. The dosages of AFB1 required to induce these changes were usually between 12.5 and 37.5 microgram/kg of body weight per day. Except for changes in biliary concentrations of pantothenic acid, folic acid, and biotin, lower threshold dosages of aflatoxin were required to produce weight loss and anorexia (5.0 and 8.5 microgram of AFB1/kg per day, respectively) than for changes in vitamins and amino acids (approximately 25 to 50 microgram of AFB1/kg per day). The data indicated that AFB1 interfered with the metabolism of B vitamins and amino acids in rabbits.

Journal ArticleDOI
TL;DR: Green pods of soybean varieties adapted to the tropics, at 65 to 85 days of maturation, have the same nutrient content (dry basis) as mature soybeans, with a good quality protein and a good content of B complex vitamins.
Abstract: Efforts in some Latin American countries directed toward the use of soybeans as a primary source of proteins for human nutrition have especially focused attention on simple home-level procedures such as the soaking and cooking of soybeans and the lime-cooking of corn-soybean mixtures. Data obtained with these two procedures indicate there is great potential in using soybeans directly in human feeding. Soaking soybeans in 0.25% NaHCO3 for 8 hr and cooking for 20 min decreases trypsin inhibitor activity more than 80%, and 40 min of cooking gives chewiness indexes similar to those of common beans with acceptable texture (10–20). The protein efficiency ratio (PER) of a mixture that was 50% soybeans and 50% common beans was 60% higher than that of common beans alone. Considering acceptability and functional characteristics of “masa” (dough) and “tortilla,” an optimum soybean level within the lime-cooking procedure was found to be 16%. Green pods of soybean varieties adapted to the tropics, at 65 to 85 days of maturation, have the same nutrient content (dry basis) as mature soybeans, with a good quality protein and a good content of B complex vitamins.

DissertationDOI
01 Jan 1981
TL;DR: Close linkage is found between the RSV genes, which control tumor regression to subgroup A RSV, and the immune response locus (Ir-GAT), which controls antibody production to the amino acid polymer, GAT^^ (Pevzner et al. 2016).
Abstract: Recent studies suggest that the gene locus controlling the fate of tumors induced by Rous sarcoma virus (RSV) is linked to the B histo­ compatibility complex. Birds carrying the dominant allele regress the tumor; homozygous recessives being unable to do so, develop large tumors and die. These are called progressors. The Bryan strain of RSV was inoculated into 220 6 week old Leghorns 1 1 2 2 1 9 1 9 homozygous for B B > B B , or B B of which the percentages of progres­ sors were 79, 22 and 56, respectively. The balance of each were regressors and survived. The B^B^ test birds were derived from special matings, i.e., high and low immune responders to the amino acid polymer, GAT. Of 67 tests progeny of the B^B^ GAT-low mating, 63 or 94% proved to be progressors, and 6% were regressors. Of 84 test progeny of the B^B^ GAT-high matings, 67% were progressors, and 33% were regressors. The difference between the high and low GAT responders is highly significant and indicates that the locus controlling the fate of RSV-induced tumors is closely linked to the locus controlling immune response to GAT. The latter maps within the Ir region of the B histocompatibility complex. 60 INTRODUCTION Previous studies have reported evidence for genetic control of resis­ tance and susceptibility to infection frou Rous sarcoma virus (RSV) inoculation in young chickens (Waters and Burmester 1961, Crittenden et al. 1964, Gyles et al. 1968). More recently Collins and co-workers (1977) and Schierman and co-workers (1977) demonstrated that genetic control of the fate of RSV tumors is closely linked to, or within, the B major histo­ compatibility complex. In addition, the Schierman group found that regression of RSV tumors, induced by the Schraidt-Ruppin strain of subgroup B, is determined by a dominant gene designated R-Rs-1^. The recessive allele, designated r-Rs-1^, permits uncontrolled (progressive) tumor growth in homozygous birds. Our study, reported herein, indicates that the RSV genes map within the Ir region of the B complex. In particular, we have found close linkage between the RSV genes, which control tumor regression to subgroup A RSV, and the immune response locus (Ir-GAT), which controls antibody production to the amino acid polymer, GAT^^ (Pevzner et