MOTION PICTURE AND ELECTRON MICROSCOPE STUDIES ON THE EMBRYONIC AVIAN OSTEOCLAST

Time-lapse motion picture studies were carried out on isolated fowl embryo osteoclasts in vitro, the cells have an extremely active ruffled border, and show vigorous pinocytotic activity. Electron microscope studies on osmium-fixed cells showed that the pinocytotic vacuoles contained bone salt crystals (as well as material which could not be identified on morphological grounds), and that the folds of the ruffled border enclosed crystals and collagen fibrils. Changes were seen in the matrix beneath the ruffled border. Initially, the collagen fibres became separated from each other and at the same time bone salt crystals became detached from them. Later, as crystals and ground substance disappeared, the outline and cross-striation of the collagen became distinct. The implications of these findings are discussed with respect to the mechanism of bone erosion.     

泽蛙单倍体细胞RNA含量对胚胎发育和成活的影响

对两栖类单倍体的综合症以及死亡原因,前人有许多不同认识,本文用实验说明,单倍体细胞的RNA含量不及二倍体的一半,并认为,单倍体泽蛙的死亡原因与其细胞中RNA含量不足密切相关。     

THE RELATIONSHIP OF THE REFERRING PHYSICIAN TO THE PSYCHIATRIST

Tumors of the adrenal glands produce hormones which cause a variety of symptoms and signs including high blood pressure, excessive growth of hair on the body and precocious sexual development. By recently developed tests, it has been possible to differentiate high blood pressure due to these tumors from hypertension due to other causes. Removal of these tumors will often alleviate changes caused by them. Localization of the tumor and appraisal of the condition of the contralateral gland should be carried out preoperatively if possible. In this, several kinds of roentgen studies are helpful. Infusions of drugs during operation can be used to control the blood pressure which otherwise would vary widely. During a ten-year period (1942 to 1951) there were observed at the Los Angeles County General Hospital 100 proved cases of non-secreting and secreting primary neoplasms of the adrenal glands. In addition, there were three cases of Cushing's syndrome due to bilateral adrenal cortical hyperplasia, and ten probable cases (four, pheochromocytomas; five, Cushing's syndrome; one, adrenogenital syndrome) in which operation was not done.