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Strychnine (1.25 × 10−5 − 1 × 10−4M) caused a reduction in the rate of afferent discharge from the muscle spindle of the isolated M. extensor longus dig. IV from the bullfrog subjected to stretch. The possible site of action of the drug is discussed.

Summary A case of Leydig cell tumour in a 6 ½ year-old boy is presented. The need for more elaborate methods for the biochemical separation of Leydig cell tumour from aberrant adreno-cortical tissue is stressed. Normal urinary output of Preganetriol and a lack of increase of the 17-beta-ketosteroids in the urine in a patient with a tumour in one of the testes serve to exclude the possibility of an adreno-cortical disorder.

The question as to the exact role played in the organism by the secretions emanating from the testicular structures is one upon which even at the present day there is no complete agreement among physiologists. From the earliest times it has been believed that some direct, co-relationship existed between the testicular fluids and the nervous mechanism of the brain and cord. Although it is manifest that psychic and nervous factors are concerned; that disturbances in the cortical centers affect the testicular secretions; and that disturbances in these secretions affect the individual psyche and character; yet we are still very much in the dark in regard to the exact mechanism which regulates such phenomena. The earlier anatomists and physiologists understood that, apart from the generative function, the testicular secretions were concerned with the development and maintenance of masculinity in general; but it was not until toward the close of the XVrTII Century that the subject began to receive any scientifi...

WE (1, 2) have recently called attention to certain forms of congenital testicular disease associated with androgen deficiency. In one type (1) there was a complete absence of spermatogonia (germinal aplasia) with preservation of Sertoli and Ley dig cells. In another form (2) a rudimentary cryptorchid testis was entirely devoid of germinal, Sertoli and Leydig cells. It was composed essentially of small solid tubules containing only undifferentiated cells. The purpose of the present communication is to record still another variety of testicular dysgenesis. In this instance Leydig cells are absent, but the Sertoli cells show variable development ranging from complete absence in some tubules to full differentiation in others. At the same time, spermatogonia are preserved, although there is no evidence of germ cell maturation. Tubular fibrosis is conspicuous and could easily obscure the primarily congenital nature of the testicular lesion.

The influence of increasing K + concentrations (5, 16, and 50 mM) on the effects of different cardenolides — digitoxin (DIG), k-strophanthidin (STR) and strophanthidin-3-bromoacetate (SBA) — on the contractile force of isolated electrically stimulated papillary muscles and on the activity of the Na + , K + -activated ATPase of guinea pig hearts was studied under comparable experimental conditions. In the experiments on isolated papillary muscles, the most potent effects were produced by DIG at all K + concentrations tested. Increase in K + concentration from 5 to 16 mM caused a significant shift in the dose-response relationship to higher DIG concentrations. In the experiments with STR a similar significant shift of the dose-response curves was observed by this change of potassium concentration. This type of K + -dependence was not found with SBA. Similar results were obtained in the experiments on isolated cardiac Na + , K + -ATPase. The most potent effects at all K + concentrations studied were again produced by DIG. Increase of K + from 5 to 16 mM significantly reduced the inhibitory effect of DIG; further increase of K + up to 50 mM was no more effective. STR was more potent than SBA at 5 mM K + and at 50 mM K + , however, at 16 mM K + an inverse relationship was found. Increase of K + from 5 to 16 mM significantly depressed only the inhibitory effects of STR on the Na + , K + -ATPase; a further increase to 50 mM had no additional influence on ATPase activity. In contrast, the effects of SBA on ATPase activity were not influenced by increase of K + from 5 to 16 mM, but were reduced significantly by 50 mM K + . These results are discussed on the basis of the hypothesis of a correlation between inhibition of cardiac (Na + ,K + )-ATPase by cardiac glycosides and the inotropic effect of these substances.

Using phase microscopy, the authors made studies of the formation and properties of spherical protoplasts of the organisms Candida utilis, Oospora suaveolens, and Geotrichum lactis, produced by digestion of the cell walls in isotonic medium with a lytic preparation obtained from the filtrates of the growth medium of Micromonospora AS. The susceptibility of various species of yeast and molds to cell wall digestion and further liberation of protoplasts was variable. MgSO4 (0.8 to 1.0 M final concentration) was a satisfactory stabilizer for producing osmotically sensitive spherical bodies. On dilution, these fragile structures lysed immediately. The naked protoplasts were able to grow, as indicated by changes in morphology. On prolonged incubation abnormal cells were formed. Reversion to normal cells was observed but was very rare. Details of the emergence of the Oospora suaveolens protoplasts were described. Protoplasts were also prepared from a variety of bacteria.

The results are given of a study of three motor components in a selected material of young and elderly diabetics and a control group: 1. the latency time ankle-extensor dig. brevis muscle by stimulation of the peroneal nerve; 2. electromyographic findings in the extensor dig. brevis muscle; and 3. the maximal amplitude of the extensor dig. brevis muscle and the anterior tibial muscle by stimulation of the peroneal nerve. Signs were found of a rapidly appearing motor neuropathy (most pronounced in the younger age group in which the beginning of the diabetes is well defined) together with a further degeneration with increasing duration of the diabetes. It was impossible to demonstrate any connection with the metabolic control. The development pattern demonstrated corresponds to that shown in a previous study in which the motor conduction velocity was used as parameter for the motor function. Some of the results obtained suggest that the nerves of the younger diabetics have a greater ability to regenerate than those of the older patients.

Mice which learned to dig nine lbs. of sand for food reward displayed little performance decrement when extinguished, replicating previous findings. In addition, it was found that: (a) mice will dig whether or not food is present in the goal box; (b) although all mice dig, food reward and deprivation significantly increase rate of digging. The results provide no evidence for “functional autonomy”.