Jewish Hospital

About: Jewish Hospital is a healthcare organization based out in Cincinnati, Ohio, United States. It is known for research contribution in the topics: Antigen & Population. The organization has 3881 authors who have published 3414 publications receiving 123044 citations.

Extracellular protons acidify osteoclasts, reduce cytosolic calcium, and promote expression of cell-matrix attachment structures.

Abstract: Because metabolic acids stimulate bone resorption in vitro and in vivo, we focused on the cellular events produced by acidosis that might be associated with stimulation of bone remodeling. To this end, we exposed isolated chicken osteoclasts to a metabolic (butyric) acid and observed a fall in both intracellular pH and cytosolic calcium [( Ca2+]i). These phenomena were recapitulated when bone resorptive cells, alkalinized by HCO3 loading, were transferred to a bicarbonate-free environment. The acid-induced decline in osteoclast [Ca2+]i was blocked by either NaCN or Na3VO4, in a Na+-independent fashion, despite the failure of each inhibitor to alter stimulated intracellular acidification. Moreover, K+-induced membrane depolarization also reduced cytosolic calcium in a manner additive to the effect of protons. These findings suggest that osteoclasts adherent to bone lack functional voltage-operated Ca2+ channels, and they reduced [Ca2+]i in response to protons via a membrane residing Ca-ATPase. Most importantly, acidosis enhances formation of podosomes, the contact areas of the osteoclast clear zone, indicating increased adhesion to substrate, an early step in bone resorption. Thus, extracellular acidification of osteoclasts leads to decrements in intracellular pH and calcium, and appears to promote cell-matrix attachment.

Local factors in the mechanism of calcification

Abstract: The fact that normal mineralization takes place at specific sites in the body indicates that a “local factor(s)” present in the calcifying matrix favors the process which gives mineralized tissues their characteristic hardness. The nature and operation of the “local factor(s)” may be regarded as the key problem in studies involving the understanding of the mineralizing process. The present approach to understanding the “local factor(s)” stemmed from physicochemical concepts of phase rule and solubility product. An attempt was made to determine from the composition and degree of mineralization whether the “local factor(s)” operates within these principles or in some way modifies the conditions so that the simple physicochemical principles do not apply. From both the agreements and the discrepancies between these concepts and the experimental results, further studies were designed to obtain insight into the minimal system required for the process of mineralization.

An Autopsy Study of Cerebrovascular Accident in Diabetes Mellitus

Abstract: A two-part study has been presented dealing with a comparison of cerebrovascular accident (CVA) as between diabetic and nondiabetic subjects. In the first part it has been shown that the frequency of CVA is increased in diabetes. While cerebral hemorrhage occurs slightly more commonly in the nondiabetic group, cerebral infarction and focal encephalomalacia occur about 1.5 times more frequently in the diabetic group. In the second part a comparison has been made of the frequency of hemodynamic, inflammatory, atheromatous, thrombotic, and proliferative vascular disease between 75 cases of diabetes and 77 nondiabetic subjects. It has been shown that hemodynamic disease of small intraparenchymal cerebral vessels occurs more frequently in the diabetic group, but the increase is of essentially the same order of magnitude as the increase in the frequency of hypertension in diabetes. No significant difference between the two groups was found as regards the frequency of inflammatory, atheromatous, or thrombotic va...

Cerebral Oxygen Metabolism after Aneurysmal Subarachnoid Hemorrhage

Abstract: Previous studies of cerebral oxygen metabolism and extraction in patients with subarachnoid hemorrhage (SAH) have yielded conflicting results. We used positron emission tomography (PET) to measure ...