摘要:

The dose-response effects of infused calcitonin gene-related peptide (CGRP), a potent vasodilator, on systemic and regional hemodynamics in the conscious rat remain incompletely defined. The radioactive microsphere technique provided these determinations before and after the intravenous administration of vehicle or 22, 65, 220, and 2200 pmol of CGRP. Neither vehicle nor 22 pmol of CGRP significantly changed any systemic or regional hemodynamic parameter. Starting at the 65-pmol dose, CGRP significantly decreased mean blood pressure and total peripheral resistance, while increasing heart rate without changing cardiac output. CGRP produced selective regional vasodilatory effects, with the coronary circulation being unusually sensitive. In contrast, CGRP caused significant increases in blood flow to the mesenteric and cutaneous circulations only at the two highest doses. CGRP increased plasma norepinephrine, epinephrine, and renin activity significantly at only the 2200-pmol dose. In conclusion, CGRP decreases blood pressure by peripheral vasodilation, with a threshold dose occurring between 22 and 65 pmol. In addition, the coronary circulation appears to be particularly sensitive to the vasodilatory properties of CGRP.

ISSN:0002-9629    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

The allograft canine heart transplanted to the neck of a recipient provides a useful model for direct measurement of atrionatriuretic factor (ANF) in the single inflow artery and the single outflow vein (pulmonary artery). The normal peripheral blood levels of ANF in the dog ranged from 25–77 pg/ml, whereas the post-transplant level in transplant outflow blood was 2262 pg/ml 30 minutes after transplant resuscitation. The cervical heart transplant model is applicable to a variety of ANF investigations.

ISSN:0002-9629    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

Variations induced by nifedipine (10 mg sublingually) in the residual lumen diameter of significant (>50%) coronary lesions were assessed angiographically in 58 patients with effort angina (group 1) and in 19 patients with Prinzmetal angina (group 2). A relationship was sought between these acute variations of the stenotic lumen and the clinical response to treatment with the same drug (20 mg four times daily). Treatment efficacy was evaluated with exercise testing in group 1 and Holter monitoring in group 2. In group 1 the residual segment of stenotic diameter showed an increase, decrease, or no change with the calcium antagonist. Nifedipine failed to improve 40% of the cases (21% unchanged and 19% worsened) in group 1. In the same group of patients, the responses to exercise tests were dissociated from the acute vasomotor pattern. Changes in the pressure-rate product also did not explain the clinical results. In group 2 the majority of lesions had compliant portions, which invariably reacted to nifedipine with dilatation. All patients with the Prinzmetal form had relief of the anginal episodes with treatment. These data suggest that the therapeutic efficacy of nifedipine in classic effort angina probably is the net result of influences on the myocardial oxygen consumption and supply, and the acute coronary vasomotor pattern does not allow to predict the clinical response. Stenotic lesions in the Prinzmetal form possess a distinct sensitivity to the relaxant action of calcium channel blockade, which reasonably explains the highly positive response to treatment.

ISSN:0002-9629    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

Patient survival while undergoing renal replacement therapy was evaluated from January 1, 1967, through June 15, 1986. There were 1,216 patients, of which 230 were treated by continuous ambulatory peritoneal dialysis (CAPD), 150 by home hemodialysis (HHD), and the remainder by dialysis in a freestanding dialysis facility (LCD). Covariate analysis found that patient survival on dialysis therapy was not influenced by race, sex, or marital status. Patients more than 60 years of age and patients with renal failure secondary to diabetes mellitus or hypertension had the worst survival on dialysis. Patients entering into CAPD were associated with diminished survival when compared to HHD but not to LCD. The ability of the initial dialysis technique to maintain a person on dialysis was not different when patients were matched for age, race, and etiology of renal failure. Only a randomized prospective trial will answer the question as to whether continuous ambulatory peritoneal dialysis can maintain a patient at home as long as home hemodialysis.

ISSN:0002-9629    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

Diffuse involvement of the pulmonary interstitium with abnormal fibrous tissue is a process that occurs in many settings. There are many possible etiologies for pulmonary fibrosis, but in the majority of individuals, a clear cause cannot be determined and a diagnosis of idiopathic pulmonary fibrosis (IPF) results. Despite limited knowledge concerning the etiology, recent advances in biomedical technology offer great promise for increasing our understanding of IPF. This review will focus on current concepts of the pathogenesis and therapy of IPF.

ISSN:0002-9629    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

The existing management of severe chronic congestive heart failure carries a dismal prognosis. Mortality over 6 months is 50% by some estimates. This fact, coupled with increasing concern for the safety and efficacy of the digitalis glycosides, has stimulated an intense search for new oral cardiotonic agents suitable for chronic administration. Despite the ability of many phosphodiesterase inhibiting agents to affect profound hemodynamic improvement acutely after oral or intravenous administration, none of the four agents here reviewed in 30 clinical trials has been adequately proven to provide benefit over conventional long-term therapy of severe heart failure. The four drugs to have undergone long-term clinical trials are amrinone, milrinone, enoximone (MDL 17043), and piroximone (MDL 19,025). For amrinone, inefficacy was revealed through carefully designed, placebo-controlled studies despite initial enthusiasm generated by open uncontrolled trials. Enoximone has suffered rapid attenuation of its hemodynamic effectiveness in most studies, and piroximone failed in its only long-term trial. Therefore, final judgment on most of these agents must await completion of controlled clinical trials, and any initial optimism stimulated by the current uncontrolled studies should be met with reservation.

ISSN:0002-9629    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

We describe a new glucose-6-phosphate dehydrogenase mutant, G-6-PD Titusville. The propositus is a 7-month-old black male infant with a transient hemolytic episode. The mutant enzyme is characterized by abnormal electrophoretic mobility, thermolability, Kmfor NADP, abnormal deamino NADP use and a decreased sensitivity to inhibition by NADPH. G-6-PD activity of hemolysate, as measured under optimal in vitro conditions, was not initially decreased, whereas fibroblasts, granulocytes, and platelets showed a markedly decreased level of enzyme activity. These properties identify G6PD Titusville as a unique variant of this X-linked, housekeeping enzyme. We conclude that although the propositus with G6PD Titusville had a transient hemolytic episode, we cannot be certain whether this association was a causative one.

ISSN:0002-9629    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

The cotton-top tamarin,Saguinus oedipus, serves as an animal model for the study of human colon cancer. This New World monkey has a high incidence of colitis and colon cancer that develops spontaneously. Evidence suggests that these diseases may be the result of a virally induced immunodeficiency. We have shown that T4+/T8+ cell ratios are significantly altered in tamarins with acute colitis and colon cancers. The T4+/T8+ ratios were 1.50 ± 0.09, 0.70 ± 0.05, and 0.48 ± 0.05 for negative controls, acute colitis, and cancer positive tamarins, respectively. Statistical analysis showed a significant difference (p ± .0005) between negative controls vs. acute colitis and cancer positive groups.

ISSN:0002-9629    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

A case of Pena-Shokeir I syndrome in a female neonate is reported. The baby died of respiratory insufficiency shortly after birth. Postmortem examination revealed marked pulmonary hypoplasia and microscopic abnormalities of the hypoglossal nucleus and anterior horn cells in spinal cord. A comparative study with respect to hypoglossal nucleus disclosed the possibility of hypoplasia of the hypoglossal nucleus as part of this syndrome. This finding led us to propose that hypoplasia of the nucleus is one of the causes of polyhydramnios, based on the lack of swallowing activity. Moreover, ectopic cross-striated muscle fibers and an increase of muscle spindles were noted in tongue. The findings, particularly the neuropathologic one, provide further insight into the pathogenesis of the syndrome.

ISSN:0002-9629    

出版商:OVID    

年代:1989

数据来源: OVID

ISSN:0002-9629    

出版商:OVID    

年代:1989

数据来源: OVID