Pulmonary function in subjects at the extremes of stature

Normal indexes of pulmonary function are based on data from large numbers of persons, using sex, size, and age as independent determinants. The influence of aging has been well examined, but few subjects at the extremes of stature have been included in previous studies. The predicted normal values are extrapolated from data acquired in studies of persons of average height. To evaluate these predictions at the extremes of stature, we performed full pulmonary function testing in 49 healthy, nonsmoking Caucasian subjects (28 men, 21 women) who were either above the 99th or below the 5th percentile for height. Nineteen subjects of average height (9 men, 10 women) performed spirometric testing. The techniques and equipment used met the American Thoracic Society's recommendations. We demonstrated that predicted values of pulmonary function testing can be extended to include those persons at the extremes of stature.

An investigation into the interaction between nitrogen nutrition, photosynthesis and photorespiration

Photosynthetic CO2 assimilation, photorespiration and levels of glycollate oxidase and ribulose bisphosphate (RuBP) carboxylase were measured in barley, wheat and maize plants grown on media containing nitrate or ammonium or in plants transferred from nitrate to ammonium. The CO2 compensation point and photorespiratory CO2 release were not altered by the nitrogen growth regime nor by transfer from nitrate to ammonium. In barley and wheat plants grown on ammonium the levels of glycollate oxidase and RuBP carboxylase per unit leaf area were higher than in nitrate grown material. These differences were not evident when the results were expressed on a protein or chlorophyll basis. The ratio of glycollate oxidase activity to RuBP carboxylase activity was not altered by the nitrogen regime.

The chromosomal locations and linkage relationships of the structural genes for the prolamin storage proteins (secalins) of rye

Rye secalins are a polymorphic mixture of polypeptides which are classified into four major groups. Previous studies have shown that the structural genes for two of the groups (the ω-secalins and 40K γ-secalins) are located on the short arm of chromosome 1R and those for a third group (the high molecular weight secalins) on the long arm of the same chromosome. Analysis of F2 grain from crosses between inbred lines of S. cereale shows that the structural genes for the ω-secalins (designated Sec 1) and the high molecular weight secalins (designated Sec 3) are loosely linked (40.8 ±3.76% recombination, 57.4 ± 11.30 cM). Analysis of wheat rye addition lines shows that the structural genes for the 75K γ-secalins are present on chromosome 2R. This locus is provisionally designated Sec 2. These genes are probably derived from those for the 40K γ-secalins by duplication, divergence and translocation. Analysis of secalin fractions from wild species of rye shows that all contain 75K γ-secalins, indicating that the duplication and divergence, if not the translocation, occurred before speciation of the genus.

The distribution of haemoglobin concentration in a sample of native high-altitude women

Two hundred and twenty-two indigenous women living in La Paz, Bolivia at an altitude of 3700 m were screened for the haematological parameters of haemoglobin, transferrin saturation, haematocrit and total iron-binding capacity. The data from 152 nonpregnant healthy women under 45 years of age were utilized in both distributional and maximum likelihood analyses in order to evaluate the prevalence of abnormal haemoglobin levels. The prevalence of anaemia and polycythaemia in the population was low and not considered to be a public health problem. Eleven per cent of the population was found to be iron deficient (less than 15% transferrin saturation).

Variation amongst protoplast-derived potato plants (Solatium tuberosum cv. 'Maris Bard')

Plants were obtained from protoplasts of shoot cultures of potato (Solarium tuberosum L. cv. 'Maris Bard') and from in situ calluses upon plants of cv. 'Majestic'. None of the protoplast-derived plants resembled each other in all of ten morphological characteristics scored and only one resembled the parental 'Maris Bard' type. As there were a number of plants regenerated from each of ten protoplast-derived calluses it is concluded that variation arose after protoplast isolation during the cell culture phase. Plants regenerated from in situ calluses of cv. 'Majestic' were quite uniform. Reported cases of variation and uniformity from cultured potato tissues are discussed. It is concluded that the variation is not a consequence of using protoplasts and that the expression or induction of variation is controllable.

Management of the brown recluse spider bite

A model to study the dermonecrotic effects of a crude fraction of venom from the brown recluse spider (Loxosceles reclusa) was developed using female New Zealand white rabbits. In the rabbit model, surgical excision of the sites of intradermally injected crude venom did not always prevent subsequent necrosis or wound dehiscence despite the use of fluorescein to determine the surgical margin. Heparin and steroids did not prevent the venom-induced necrosis and were much less effective than surgical excision or injecting a specific antivenom. When given within 24 hours, the specific antivenom raised against the brown recluse spider venom blocked or markedly attenuated the toxic effects of the venom in the rabbit model system.

An Examination into the Phenomenon of Granulation, in Mu Particles of Stock 540 Paramecium Aurelia

Mu particles in paramecia incubated at 37 °C granulate. The treatment causes the loss of mu and granulation is a prerequisite for loss. The granules form along the length of the mu, at intervals of about 1.50 µm. Each granule has a diameter of about 0.5 µm and consists of a number of ribosome-like particles which have the same dimensions as 70S ribosomes.

Further studies on the maintenance of mate-killer (mu) particles in Stock 540 Paramecium aurelia

1. Mu particles can be removed from stock 540Paramecium aureliaby incubation in a solution of 1·0 mg/ml RNAase for 12 h. Only a relatively small percentage of cells become mu-free and it is suggested that this variation is due to the activity of the M genes producing metagons at different times.

2. Paramecia, made mu-free by growth at elevated temperatures, can be re-infected with mu by allowing the cells to swim in a brei of stock 540 paramecia. The re-infection is only permanently successful with cells that were made mu-free 10 days earlier.