Monoclonal antibodies to different sites on human transcobalamin II

Two IgG1K monoclonal antibodies to human transcobalamin II (TC II) were generated. These antibodies, 16.1 and 16.6, did not cross-react with the other two types of human cobalamin-binding proteins, intrinsic factor and R binder (TC I). Both antibodies cross-reacted with orangutan and simiang TC II but not with TC II from cynomolgus and howler monkeys, who are less closely related to humans. This finding suggests close structural similarity of human to ape TC II. The antibodies also did not react with TC II of lower mammals which included the horse, dog, guinea pig, and mouse; in particular, reaction did not occur with rabbit TC II, which has been considered structurally close to human TC II. Neither of the two antibodies was directed at the cobalamin-binding site of TC II. However, antibody 16.6 hindered TC II binding to cell receptor. This reactivity with the receptor-binding site should prove particularly useful in studies of that region of the TC II molecule.     

Effects of ambient oxygen and of fixed nitrogen on concentrations of glutathione, ascrobate, and associated enzymes in soybean root nodules

Soybean (Glycine max [L.] Merr.) root nodules contain the enzymes of the ascorbate-glutathione cycle for defense against activated forms of oxygen. Nodulated roots of hydroponically grown soybean plants were exposed to atmospheres containing 2, 21, 50, or alternating 21 and 50 kilopascals of O₂. The activities of ascorbate (ASC) peroxidase, monodehydroascorbate (MDHA) reductase, dehydroascorbate (DHA) reductase, and glutathione (GSSG) reductase were higher in nodules exposed to high pO₂. Nodule contents of ascorbate and reduced glutathione were also greater in the high pO₂ treatments. Treatment of nodulated plants with fixed nitrogen (urea) led to concomitant decreases in acetylene reduction activity, in leghemoglobin content, and in activities of ASC peroxidase, DHA reductase, and GSSG reductase. Activity of MDHA reductase and glutathione concentrations in nodules were not affected by treatment with urea. The enzymes of the ascorbate-glutathione cycle were also detected in uninfected soybean roots, although at levels substantially below those in nodules. These observations indicate that the ascorbate-glutathione cycle can adjust to varying physiological conditions in nodules and that there is a key link between N₂ fixation and defenses against activated forms of oxygen.     

Phylogenetic and physical analysis of the 5'' leader RNA sequences of avian retroviruses.

A study of the secondary structures of the 5'-leader RNA sequences of avian leukosis/sarcoma viruses was conducted using phylogenetic sequence alignment, theoretical structures calculated from base-pairing interactions involving the calculated minimal delta G values, and RNaseT1 sensitivity. The results suggest that all of the avian retroviral RNA leaders may be able to adopt similar conformations. Open reading frames in the leader RNAs may be positioned to facilitate viral activities such as translation and packaging of the genomic RNA into virus particles.     

Plasma catecholamine levels during water immersion in man

In ten normal subjects thermoneutral neck-out water immersion produced a highly significant natriuresis and diuresis mediated via an induced central hypervolaemia. During immersion suppression of plasma noradrenaline and adrenaline was observed but no change occurred in plasma dopamine levels. No correlation was found between the suppression of noradrenaline and the diuresis and natriuresis. The reduction in plasma noradrenaline observed may reflect a widespread diminution of sympatho-adrenal activity during water immersion. This reduction could be a consequence of the cardiovascular changes of immersion and may not be directly involved in the mechanism of the renal response.     

Comparison of health problems related to work and environmental measurements in two office buildings with different ventilation systems.

A cross sectional survey investigating "building sickness" was carried out in two buildings with similar populations of office workers but differing ventilation systems, one being fully air conditioned with humidification and the other naturally ventilated. The prevalence of symptoms related to work was assessed by a questionnaire administered by a doctor. A stratified, randomly selected sample of workers was seen (84% response). Building sickness includes several distinct syndromes related to work, most of which were significantly more common in the air conditioned building than the naturally ventilated building--namely, rhinitis (28% v 5%), nasal blockage and dry throat (35% v 9%), lethargy (36% v 13%), and headache (31% v 15%). The prevalence of work related asthma and humidifier fever was low and did not differ significantly between the two buildings. An environmental assessment of the offices was performed to attempt to identify possible factors responsible for the differences in the prevalence of disease. Globe temperature, dry bulb temperature, relative humidity, moisture content, air velocity, positive and negative ions, and carbon monoxide, ozone, and formaldehyde concentrations were all measured. None of these factors differed between the buildings, suggesting that building sickness is caused by other factors.     

Children's Hospital Admissions and Mother's Menstruation

Of 100 children''s emergency admissions to hospital nearly half (49%) were admitted during the mother''s paramenstruum. There was a statistically significant association between the mother''s menstruation and the child''s admission both for accidents and for illnesses. The eldest child in the family appeared to be most affected.