Smoking in Pregnancy and Vitamin B12 Metabolism

In pregnancy the level of serum vitamin B₁₂ is lower in women who smoke than in non-smokers. This finding occurs independently of social class, parity, or level of haemoglobin. In addition, the mean serum B₁₂ level tends to be less in women who are anaemic and is less in those women who have smaller babies. These findings may be an effect of the cyanide content of tobacco smoke, since cyanide may be detoxified by a mechanism which depletes the stores of vitamin B₁₂ in the body.     

Vitamin B12 Malabsorption after Cobalt Teletherapy for Carcinoma of the Bladder

After cobalt teletherapy for carcinoma of the bladder, eight out of 14 consecutively admitted patients were shown to have malabsorption of vitamin B₁₂, though none had developed a megaloblastic anaemia. Despite lack of symptoms this group of patients is at risk after radiotherapy.     

The Relationship of Cobalt Requirement to Vitamin B12-dependent Methionine Synthesis in Rhizobium meliloti

As a growth factor, Rhizobium meliloti required cobalt ion, or vitamin B₁₂ which was found to be incorporated into the cells without decomposition to cobalt ion. Trial of replacement for cobalt ion by the addition of various compounds to the cobalt-deficient medium revealed that methionine could substitute for cobalt ion and promote the growth in response to its concentration. Furthermore, B₁₂-dependent methionine synthetase was demonstrated in the cell-free extracts of this microorganism. The morphological change of R. meliloti by the additions to the medium was observed microscopically.     

Metabolism of Glutamate in Purple Nonsulfur Bacteria Participation of Vitamin B12

Purple nonsulfur bacteria, Rhodospirillum rubrum and Rhodopseudomonas spheroides were found to possess coenzyme B₁₂-dependent glutamate mutase activity. Cell-free extracts of these bacteria grown on Co²⁺-containing media catalyzed the conversion of glutamate to β-methylaspartate and further to mesaconate. The activity of the cell-free extracts of these organisms cultivated on Co²⁺-deficient media was markedly lower than that of the normal cells. Addition of coenzyme B₁₂ to the former reaction mixture enhanced the mesaconate formation via β-methylaspartate. These results indicate the involvement of coenzyme Independent glutamate mutase of these bacteria in the dissimilation of glutamate to acetyl-CoA and pyruvate through the following pathway.

glutamate→β→methylaspartate→mesaconate→citramalate→→acetyl-CoA, pyruvate On the other hand, a greater part of glutamate was converted to α-hydroxyglutarate and succinate with the cell-free extracts of these photosynthetic bacteria. This fact, taking account of the presence of propionyl-CoA carboxylase in these bacteria, implies the participation of coenzyme B₁₂-dependent (R)-methylmalonyl-CoA mutase in the formation of succinate via the following route.

glutamate→α-ketoglutarate→α-hydroxyglutarate→propionate→propionyl-CoA→(S)-methylmalonyl-CoA→(R)-methylmalonyl-CoA→succinyl-CoA     

Production of Vitamin B12 by Micromonospora

Various species of Micromonospora produced yields of vitamin B(12) activity as high as 11 mug/ml under conditions of shaken flask fermentation.     

Some Aspects of Olfaction in Fishes, with Special Reference to Orientation

Olfactory cues play an important role in the behavior of fishes,such as the procurement of food, recognition of sex, defenseagainst predators, parental behavior, and orientation. By monitoringand three-dimensional photographic techniques, analyses weremade of some aspects of orientation mechanisms through olfaction.None of the marine and freshwater species investigated movedrandomly in an experimental environment void of directionalcues. When changing direction, the radius of the curve is fixedwithin fairly narrow limits and seems to be species-specific.Left and right-hand turns are not evenly distributed. This locomotorbehavior results in a non-random pattern of relatively rigidparameters. The introduction of an odor without directionalcues causes these parameters to change drastically. Invariably,the radius of the curve in changing direction decreases andthe ratio of left-handed to right-handed turns is greatly changedin most experiments. When an attractant odor is introduced uni-directionally,none of the species studied could locate the source, unlessthe odor was associated with a differential in the rate of flowof the water. It is suggested that an attractant odor releasesrheotactic response, which was not present in the animal inthe experiments previously referred to, so that the localizationof the source of the odor takes place through rheotaxis ratherthan through orienting cues provided by the odor gradient. Furthermore,it is proposed that this mechanism forms the basis for homingorientation in those migrating species in which olfactory cuesare required for the localization of spawning grounds in riversystems.     

Role of Third Serum Vitamin B12 Binding Protein in Vitamin B12 Transport

A third vitamin B₁₂ binding protein present in normal serum has been shown to participate in transport of labelled vitamin B₁₂ absorbed from the gut. All three vitamin B₁₂ binding proteins in serum were labelled at the same time after oral administration of vitamin B₁₂, implying that “free” vitamin B₁₂ reached the portal blood from the gut mucosa.     

Vitamin B12 Production by a Methanol-Utilizing Bacterium

Vitamin B(12) production by a newly isolated strain of a methanol-utilizing bacterium was studied. The maximal yield of the vitamin, 2.6 mg/liter of medium was attained by optimization.     

Strategies of Emigration and Transfer by Primates,with Particular Reference to Gorillas

In many primate species, more ♂ ♂ than ♀ ♀ leave their natal group and transfer to another. In man, chimpanzee and the gorilla, however, the reverse is the case. This paper presents detailed data for the gorilla on individuals' movements into and out of breeding units. Comparisons are made with other primates, and with data on two non-primate species in which ♀♀ rather than ♂ ♂ move between breeding units. Proximate causes and functions of emigration and transfer are considered, and the reasons (proximate and evolutionary) for the observed sex differences in frequency of movement are discussed.     

Microbiology of Nigerian Palm Wine with Particular Reference to Bacteria

The bacteria isolated from samples of wine produced by the fermentation of the saps of Elaeis and Raphia palms were identified as Micrococcus, Leuconostoc, Streptococcus, Lactobacillus, Acetobacter, Serratia, Aerobacter (Klebsiella), Bacillus, Zymomonas and Brevibacterium . The organisms occurring most frequently belonged to the first 5 genera. The change from c. pH 7 to c. pH 4.5 during fermentation appeared to be due to lactic acid bacteria and/or certain Gram negative bacteria, e.g. Serratia and Aerobacter (Klebsiella) spp. From about the 3rd day onwards, Acetobacter spp. were recovered.     

Some Effects of Light on Excised Wheat Roots with Special Reference to Peroxide Metabolism

When excised wheat roots are exposed to blue light, catalase activity changes in a way to he expected as a result of photodestruction with first order kinetics. Wheat root catalase in vivo is less light sensitive than animal catalase in vitro, possibly due to internal screening. Illumination of the roots with red light causes some increase in catalasc activity. Peroxidase activity is much less affected by light. No relation has been found between catalase destruction and chlorophyll formation. The ability of roots to oxidize pyrogallol to purpurogallin (by other workers interpreted as peroxide production) is decreased by light, especially blue light. On the contrary, one peroxide producing enzyme, glycolic acid oxidase, was detected only in roots grown in blue light. The total flavin content, or the fraction present as FAD, is not affected by light. The ascorbic acid content is low, but slightly increased by blue light.