Effect of chloral hydrate on methane and propionic acid in the rumen

Methane production from pyruvate by mixed rumen bacteria in vitro was nearly totally inhibited by chloral hydrate (0.1 mumole/ml of incubation fluid). This effect was accompanied by an accumulation of gaseous hydrogen and an increase in propionic acid production. Infusion of chloral hydrate (4 g/day) into the rumen of a sheep produced the same effects. Evidence is presented for a direct toxic effect of chloral hydrate upon methane bacteria. Results are discussed in terms of fermentation balances.

The salivary gland chromosomes of Chironomus oppositus Walker (Diptera : Nematocera)

Chromosome maps for C. oppositus, which are intended to serve as a standard for the genus Chironomus in the Australasian region, are presented. This species possesses the usual four salivary gland chromosomes and the seven arms, named A-G by Keyl (1962), can be recognized. This species has the combination AE, BF, CD, G, corresponding to the pseudothummi group of Europe. The relationship of C. oppositus to European species of the pseudothummi group is not definite as an independent origin of this arm combination is possible. The species is quite polymorphic, 13 inversions having been recognized. The limits of these inversions, with preliminary data on their distributions, are given.

A radioisotopic method for determining optimum non-surgical therapy for advanced cancer. I. Experimental data

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Pinocytotic response of circulating erythrocytes to specific blood grouping antibodies

Human blood samples from adults and newborns of blood groups O, A, and B were treated with either anti-A blood grouping serum, ferritin-conjugated anti-A serum, free ferritin, or saline and then prepared for electron microscopy. Morphological differences were observed between the untreated erythrocytes of infants and adults. Circulating red cells of newborns were frequently vesiculated (25.5%), whereas those of adults only occasionally showed vesicles (5.5%). On the basis of morphology and incidence, the majority of these vesiculated cells seemed to be mature erythrocytes. The introduction of anti-A serum to group A erythrocytes of infants appeared to stimulate vesicle formation, but anti-A serum did not have a similar effect on group O or B cells of infants or on group A cells of adults. Vesicles which formed in response to antiserum treatment appeared to be the result of pinocytosis. In contrast to the well dispersed ferritin along the membrane of agglutinated adult cells, the ferritin particles on the infants' cells were frequently clustered at irregular intervals. These accumulations seemed to lead to invaginations of the cell membrane, resulting in ferritin-lined intracytoplasmic vesicles. The addition of free ferritin or ferritin-conjugated antibodies of the wrong specificity to red cells did not increase vesicle formation.

The Chediak-Higashi anomaly. A report of two cases

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Evidence concerning the relationship between health and retirement

Survey data concerning the incidence of serious illness before and after retirement are analysed in two ways,

(i) by comparison of groups of retired men with groups of men in the last ten years of their working lives; (ii) by examining and comparing the trends over time before and after retirement.

Whereas the first method would lead to a conclusion that there is no difference between retired and working men, the second method shows a distinct drop in the incidence of serious illness in the two years following retirement and a slower rate of increase thereafter. It is concluded that retirement is associated with a substantial lowering in the incidence of serious illness.

Investigation of sensory interaction in the hooded rat

An attempt was made to determine the effects of tone on the visual acuity threshold of the rat. Acuity thresholds were ascertained using the Lashley jumping stand with black and white stimulus cards. A pure tone of 7,500 cps at three intensity levels was introduced as accessory stimulus. The results indicated (1) no consistent lowering of S's visual acuity by the introduction of a tone, (2) no within- S differences between tone and no tone when the above threshold and threshold stimuli were analyzed separately, (3) increasingly better performance from low to medium intensities with a decrease in performance at the higher intensity level.