Biomedical subjects

S R Frankel

Publications and source records attributed to S R Frankel.

38 records · Page 3Linked to original sources

PubMed1980

Effects of graded hypoxia on contraction of cultured chick embryo ventricular cells.

The quantitative relationship between a given decrease in O2 tension (Po2) and the degree of depression of contractile function is difficult to define in intact myocardial tissues because of uncertainty in estimation of diffusion limitations. We therefore have studied the effects of hypoxia on contractility in a system with minimal series diffusion barriers, consisting of single cells within spontaneously contracting monolayers cultured from 10-day-old chick embryo ventricles. Reversible decreases in amplitude and velocity of cell wall motion occurred over a 3- to 4-min period when perfusate Po2 was less than 12 mmHg, and a maximum depression to about 30% of control levels occurred at Po2 values less than 4 mmHg. On reoxygenation, recovery of amplitude and velocity of contraction occurred in less than 15 s. Inhibition of glycolysis with 0.1 mM iodoacetate resulted in a more marked decrease in contraction amplitude and a significant slowing of beating rate during hypoxia. In addition, the critical Po2 at which contractile function became impaired was increased to about 16 mmHg. Thus, high-energy phosphates derived from anaerobic glycolysis appear to be able to support a reduced level of contractility during brief periods of hypoxia in these cultured heart cells.

Animals↗

PubMedDate not supplied

Giant cell vasculitis with extravascular granulomas in an adolescent.

We describe an 18-year-old white male who developed lower extremity ischemia requiring amputation. He presented at 14 with pulmonary infiltrates, hepatosplenomegaly, fever, rash, adenopathy, uveitis, and arthralgias; clinical and laboratory findings were consistent with Mycoplasma pneumoniae infection. Despite adequate treatment with antibiotics, he developed chronic arthralgias and fevers, with rash and pericardial effusion. Criteria for the diagnosis of systemic lupus erythematosus were not met; juvenile rheumatoid arthritis was diagnosed presumptively. Over the subsequent 4 years he developed lymphadenopathy with biopsy-proven nonnecrotizing granulomas, chronic leg ulceration with granulomatous histology, and acute-onset impending gangrene of the left foot. A biopsy of the posterior tibial artery demonstrated giant cell arteritis. Although the histologic features were consistent with Takayasu's arteritis, complete aortic arteriography was normal. Examination of the amputated leg showed multifocal segmental giant cell arteritis. Clinicopathologic features suggested, but were not fully consistent with, juvenile systemic granulomatosis. His disease may represent a separate sarcoid-like entity in the broad spectrum of vasculitis.

Adolescent↗