Showing papers on "B vitamins published in 1976"

The B-vitamins in malnutrition with alcoholism. A model of intervitamin relationships.

Abstract: 1. The B-vitamin status of fifty-nine patients, mainly from the lower socio-economic classes in Bombay, with a history of chronic malnutrition, and of alcoholism of 1-5-20 years' duration, was studied before and during treatment, and in relation to their clinical, especially neurological, condition. These patients were divided into two neurological categories: (I) those with peripheral neuropathy (mainly sensory and distal) alone, (2) those with mental changes (mainly confusion and disorientation) also. Both categories frequently showed pellagrous pigmentation and mucocutaneous signs of B-vitamin deficiency. 2. Thiamin and erythrocyte transketolase (EC 2.2.1.1) activity, riboflavin, nicotinic acid, pantothenic acid, total and pyridoxal fraction of vitamin B6, folate and total vitamin B12 were estimated in the blood and the cerebrospinal fluid (CSF) of these patients, and also in the blood of sixty-nine control subjects and in the CSF of some of them. The concentrations of all the vitamins, except vitamin B12, were highly significantly lower in the blood of patients of category I compared to the controls, and erythrocyte transketolase activity and pyridoxal concentration in patients of category 2 were significantly lower than those of category I patients. Blood pantothenic acid and folate concentrations were reduced less consistently. 3. Serum vitamin B12 concentration was significantly increased (though within normal range) in the patients compared to the control group, probably because of the moderate hepatic insufficiency (as assessed by liver function tests) in the former. 4. The concentrations of thiamin, riboflavin, nicotinic acid and total vitamin B6 were also highly significantly lower in the CSF in patients of category I compared with controls. Furthermore, thiamin, nicotinic acid and total vitamin B6 concentrations were significantly lower in patients of category 2 than those of category I patients, indicating that CSF levels reflect better the neurological status of these patients. 5. There was a moderate increase in the blood concentration of all the vitamins tested, after a relatively poor hospital diet alone. There was a concurrent increase in the blood levels of thiamin, riboflavin, nicotinic acid and pantothenic acid after parenteral treatment with either thiamin or nicotinic acid. The administration of pyridoxine resulted in a significant increase in the blood levels of riboflavin and the pyridoxal fraction of vitamin B6.

B-vitamin retention in meat during storage and preparation. A review.

Abstract: In this review, the authors bring together present information on B-vitamin retention in frozen meat as it is affected by: Aging before freezing, the freezing process and length of frozen storage, cooking from the frozen or thawed state, method of thawing, cooking methods, and holding and reheating conditions. Literature reports on various cuts of pork, chicken, beef, lamb, turkey and veal are cited. Thiamin, riboflavin, niacin, vitamin B6, pantothenic acid, vitamin B12, biotin, choline, and folic acid are considered.

Nutritional problems in the African region.

Abstract: Energy-calorie malnutrition (ECM) is the commonest nutritional problem in developing countries in Africa: 0.5-5% of the population under 6 years of age suffer from the severe forms and 4-40% from the moderate forms. It is possible that as many as two-thirds of the preschool children in developing countries in Africa suffer from some EPM (protein-calorie malnutrition). The recent Sahelian drought and civil wars in some countries in Africa have increased the size of the problem and the severity and prevalence of EPM in several parts of Africa. The aetiological factors of EPM in Africa include shortage of calories and protein, as well as increasing and recent tendency to abandon too early breast feeding, sensory deprivation, psychological and emotional trauma, ignorance, superstition and cultural taboos. The evidence available at the moment does not clearly indicate that effects of EPM on learning and behaviour are permanent, although the functions of the brain in the acutely malnourished child are defective. Malnutrition impairs immunological capability and surveillance, and hence augments the mortality and morbidity of infections such as measles especially by impairing cell-mediated immunity and, to a lesser extent, synthesis of immunoglobulins. Endemic goitre (prevalence varies from 2 to 90% in various age groups) in several parts of Africa is due to either iodine deficiency (Ethiopia) or to the goitrogenic effect of cassava diet (Zaire and Nigeria). Deficiencies of vitamins A, B complex and D have been reported in several parts of Africa, albeit sporadically. Dietary intoxications include: a) aflatoxins which may be important in the pathogenesis of hepatic carcinoma, one of the commonest neoplasms in developing countries in Africa; b) chronic cyanide intoxication from cassava (manihot) food derivatives, which on circumstancial evidence seems to be an important aetiological factor of a crippling neurological disease, the tropical ataxic neuropathy in Nigeria and Tanzania; c) organophosphate insecticides. The rarity of certain diseases in the Africans may be related specifically to the African diet, especially the high fibre and low animal fat content of many of the African diets. Examples of such diseases are atherosclerosis in the non-hypertensive non-diabetic population, cancer of the large bowel, varicose veins and perhaps multiple sclerosis.

Radiation protection of vitamins in aqueous systems

Abstract: Thiamine and other vitamins of the B complex group are highly : ensitive to γ-radiation in aqueous solution owing to their high reactivity with the primary species formed by radiolysis of water, viz. hydrated electrons and hydroxyl radicals. In order to protect these compounds from radiolytic degradation, nitrous oxide and oxygen have been used as scavengers for the hydrated electrons and glucose for the hydroxyl radicals. By comparison of uv spectra it is shown that the above vitamins do not undergo radiolytic degradation in presence of nitrous oxide and glucose or oxygen and glucose. The importance of these results in connection with the sterilization of vitamin preparations is discussed.

Homotopy Triangulations of Pseudo Lens Spaces and Actions on Products of Spheres

Abstract: In the last decade the classification of free actions of cyclic groups Zr on homotopy spheres has been studied extensively. Given a free Zr action on a homotopy sphere the orbit space is homotopy equivalent (but not necessarily simple homotopy equivalent) to a lens space [t13]. So the study of free Zr actions on homotopy spheres is equivalent to the problem of classifying manifolds of the homotopy type of lens spaces. Surgery theory gives a complete classification in the PL and topological categories. The case r = 2 was attacked by Lopez de Medrano [8] and Wall [16, § 14D]. The case r odd was settled in the work of R. Lee [7], Browder et al. [4, 5]. As a next step one can consider free Zr actions on manifolds E homotopy equivalent to the cartesian product of two spheres. One might then trie to replace the lens space by a manifold defined as follows: Let a, b complex representations of Zr of degree p + 1, q + 1 in V~, V b. Let S,, Sb the unit spheres in V,, Vb and assume that they are free Zr-manifolds. Our candidade is then M'=S,, x Sb/Z r. Such an orbit space we call a pseudo lens space. However in general it is not true that the orbit space E/Zr is homotopy equivalent to such a pseudo lens space. But we think it is worthwile to study those actions having this property. They can be obtained from actions whose orbit space is simple homotopy equivalent to M by operation of the Whiteheadgroup W(Z,). So we further restrict to so called simple actions, thus obtaining at least a lower bound for the set of all actions. The precise problem we study is the following: In the PL category we consider m-dimensional closed oriented manifolds E with free Zr-actions, an orientation preserving Zfequivariant homotopy equivalence e:E---,SoxSb inducing a simple homotopy equivalence between orbit spaces. Two such (E i, e~), i= 1, 2 are considered equivalent if there is an equivariant PLhomeomorphism c:Et~Ez with e2oc equivariantly homotopic to e t. The set 5~(M) of equivalence classes of simple actions is in 1 I correspondence to the set hT(M) of equivalence classes of homotopy triangulations [16, p. 102] on M. The sugery exact sequence [16, p. 107, 1 t l ]

Effect of Nitrogen Topdressing on B-vitamin Content of Rice Grain

Abstract: Investigations have been carried out to determine the effect of nitrogcn topdressing at panicle formation stage and full heading stage on the thiamine, riboflavin, nicotinic acid, pantothenic acid, biotin and fblic acid content of brown rice and milled rice of two varieties. As to the brown rice, both the topdressings had a significant effect on the decrease of the riboflavin content and the increase of the nicotinic acid content. There was, however, no significant effect of the topdressings on the B-vitamin content of the milled rice. On the other hand, the riboflavin, nicotinic acid and biotin content of the brown rice and the pantothenic acid content of the milled rice differed significantly between both the varieties

Effect of vitamin B6 on Ieucine-induced

Abstract: Disturbances in the tryptophan-niacin pathway seen in endemic pellagra among sorghum eaters have been ascribed to high dietary intake of leucine. Vitamin B, plays an important role in several steps of this pathway. Therefore, studies on possible metabolic interrelations between excess dietary leucine and vitamin B, were undertaken in normal healthy human subjects. The results indicated that vitamin B, could successfully counteract the effects of leucine on quinolinic acid excretion in urine, and on in vitro nicotinamide nucleotide synthesis by erythrocytes, and also could correct the abnormalities of 5-hydroxytryptamine metabolism induced by excess leucine. These observations suggest that vitamin B, nutritional status may have a contributory role in the pathogenesis of endemic pellagra. Am. J. C/in. Nuir. 29: 177-181, 1976. The occurrence of endemic pellagra among sorghum eaters has been reported from some parts of India, and the results of several studies have demonstrated that the high amount of the essential amino acid-leu- cine-present in sorghum is etiologically re- lated. Administration of leucine to normal human volunteers has been found to increase the urinary excretion of quinolinic acid (1), to inhibit the capacity of erythrocytes to synthe- size NAD in vitro (2), and to depress the activity of quinolinate phosphoribosyl transferase-a key enzyme in NAD synthesis in rats (3). It has recently been reported that pyridoxine deficiency in man leads to in- creased excretion of quinolinic acid, in addi- tion to increased xanthurenic acid, and that these changes are corrected by the admin- istration of pyridoxine (4). In women taking steroidal oral contraceptives, which are known to lead to pyridoxine deficiency, as well as in a subject given deoxypyridoxine- which is a pyridoxine antagonist-increased excretion of quinolinic acid in urine has been reported (5). A number of enzymes in the tryptophan- niacin- ribonucleotide pathway are vitamin B6-dependent, and disturbances in this path- way are a feature of pyridoxine deficiency. Although pellagra is a disease arising from deficiency of nicotinic acid, it is not unusual to see signs of associated deficiency of other vitamins of the B complex group. Studies on possible metabolic interrelationships between excess dietary leucine and pyridoxine were, therefore, undertaken to determine whether pyridoxine nutritional status had a contribu- tory role in the pathogenesis of endemic pellagra among sorghum eaters.