Mechanism of lipolysis induced by electrical stimulation of the hypothalamus in the rabbit

Electrical stimulation of the ventro-medial hypothalamus of the rabbit elevated plasma glycerol concentration. This elevation was suppressed by treatments of the animals with hexamethonium and propranolol, or by adrenalectomy, but was not suppressed by treatments with atropine and phentolamine. These results would indicate that the effect of electrical stimulation of ventro-medial hypothalamus is mainly mediated by catecholamine(s) liberated from the adrenal medulla and acts on beta-receptor of adipose tissue.

Effects of catecholamines on the lipolysis of two kinds of fat cells from adult rabbit

The administration of various catecholamines and adrenocorticotropic hormone to adult rabbit elevated plasma glycerol concentration. These catecholamines also induced the in vitro lipolysis of isolated interscapular fat cells but could not bring about the lipolysis of epididymal ones, while adrenocorticotropic hormone induced the lipolyses of both kinds of fat cells. It may be speculated from these results that catecholamines liberated endogenously in adult rabbit cannot act on all systemic adipose tissues but have lipolytic effects on a part of them.

Karyometric and cytophotometric studies on nucleic acids in the culture of human lymphocytes with phytohemagglutinin

Lymphocyte transformation with phytohemagglutinin (PHA) was analyzed by karyometry and cytophotometry of single cells. The former showed the distribution of various-sized transforming cells, and the latter the increase of DNA and RNA. Two different types of karyograms were obtained; one with three peaks corresponding to 2c, 4c, and 8c, and the other with only a 2c peak. Although small in number (8%), karyometry showed that DNA synthesis took place in the extremely early stage of transformation, 1 h after stimulation with PHA, which was proved by cytophotometry and ultrastructural findings. An increasing curve of DNA and RNA revealed that a lymphocyte continued to enlarge from 2c to 4c and divide again through the normal cell cycle in a suitable condition. The largest blast cell, a polyploid cell, may be induced by the lack of a sufficient amount of RNA and protein in need of cell division, and may be a degenerative cell in the strict sense. Among the large cells with blastlike appearance, there were a considerable number of so-called degenerative cells with a low amount of DNA. The ratio of RNA to DNA increased steeply in the actively DNA synthesizing S phase, which supports the morphologic findings of blast cell, the appearance of basophilic cytoplasm, and active-looking nucleoli.

Clinical significance of alpha2H-globulin

Incidences of alpha2H were investigated in sera from patients with various malignant and nonmalignant diseases. With counterimmunoelectrophoresis, alpha2H was detected in a wide variety of neoplastic diseases, and also in nonmalignant hematological disorders. Diagnostic significance was described regarding primary hepatoma and acute myelogenous leukemia. Factors affecting alpha2H levels in sera were also discussed in relation to the neoplastic and nonneoplastic disease process.

The effects of cosmic particle radiation on pocket mice aboard Apollo XVII: XI. Results of eye examination

Five pocket mice (Perognathus longimembris) were flown on Apollo XVII, and four survived. All the eyes, except one eye from the dead flight mouse, were examined histologically. In the four surviving mice, a total of five cosmic ray particles which had registered in the subscalp particle detectors had trajectories that intersected the eyes. Four of them (Z equal to 6-9 for three of the particles and Z larger than or equal to 10 for the fourth) most likely went through the head before reaching the particle detector, while the thindown direction of the fifth (Z larger than or equal to 10) was not determinable. The retinas of the flight animals were found free from histological alterations such as might have been expected from encounters with cosmic ray particles.

The effects of cosmic particle radiation on pocket mice aboard Apollo XVII: V. preflight studies on tolerancee to oxygen and heat. Part III. effects on eyes

A study was made of the eyes of eight pocket mice exposed to oxygen at partial pressures of 8, 10, or 12 psi over a period of 7 d. At the termination of the exposure, the animals were decompressed to sea-level O2 either immediately or over a period of 30, 60, or 90 min. No pathological changes were found in any of the eyes, except in the retina of one of the animals exposed to 12 psi O2. Here, only a single rod photoreceptor was found damaged, an observation not regarded as significant. Hence, an oxygen partial pressure as high as 12 psi in the camister in which pocket mice were expected to fly on Apollo XVII would probably have no deleterious effect on the eyes of the animals.

An electron microscopic investigation of age-dependent changes in the flight muscle of Musca domestica L

The thoracic flight muscle from adult male NAIDM house flies was examined, from emergence to very old age. Thin sections stained with uranyl acetate and bismuth showed no myofibrillar or mitochondrial degeneration from 1 day to 19 days post-emergence, contrary to earlier reports. Some progressive loss in glycogen content and increase in mitochondrial size were observed for muscle from young to very old flies. However, there was no conclusive evidence of fusion of smaller mitochondria into larger ones with advancing age, despite exhaustive examination of representative sections of muscle samples of adult males of different ages.