摘要:

ABSTRACT: The effects of 800 mg of elemental calcium per day (calcium carbonate or calcium citrate) on blood pressure were compared with a placebo in a controlled randomized, crossover, double-blinded trail involving 26 patients with uncomplicated primary hypertension. Each patient took two of the three forms of therapy orally for 8-week intervals with a 2-week washout period in between. Standing mean blood pressure rose an average of 5.7 mm Hg on placebo, rose an average of 0.5 mm Hg on calcium carbonate, and fell an average of 2.2 mm Hg on calcium citrate. Changes in sitting mean pressures averaged +1.9 mm Hg on placebo, −0.4 mm Hg on calcium carbonate, and −0.4 mm Hg on calcium citrate. Some patients had a fall, others had a rise in blood pressure on each form of calcium. Similarly, inconsistent responses were noted among the nine patients who took both forms of calcium. Neither initial nor post-treatment biochemical measures nor patient characteristics were predictive of the blood pressure response. Combinations of various measures and characteristics analyzed by the multiple regression technique explained only 30% of the overall variability in blood pressure. Therefore, until ways can be found to predict the response, calcium supplements should not be routinely prescribed for the treatment of hypertension and, if given for any indication, blood pressure should be monitored

ISSN:0002-9629    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

ABSTRACT: The metabolism of radiolabeled125I-low density lipoprotein (LDL) was studied in cultured human aortic smooth muscle cells (SMC) to investigate potential mechanisms contributing to heart attack and stroke in young women taking oral contraceptive (OC) preparations. No consistent difference was discerned in the capacity of these cells to bind and internalize LDL following 24-hour exposure to pooled lipoprotein-poor (d > 1.25 gm/ml) serum from nonsmoking OC users and controls. However, significantly (p > 0.01) less soluble radioactive material was released into the media from dishes containing SMC incubated with OC serum, indicating that their capacity to degrade LDL was impaired. Increased amounts of both cholesterol and cholesterol ester and electron microscopic evidence of lipid accumulation were found in SMC grown for 12 days under standard culture conditions with 10% OC serum. This combination of in vitro findings suggests that OC use may accelerate the development of cardiovascular disease in some women by modifying the metabolism of LDL by cells of the arterial wall.

ISSN:0002-9629    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

ABSTRACT: The activities of the Krebs cycle (KC), glycolytic pathway (GP), and the hexose monophosphate shunt were studied in endomyocardial biopsies obtained from 25 patients and were related to left ventricular stroke work index (LVSWI). Unexpectedly, KC activity was greater in patients with a reduced LVSWI than in those with a normal or elevated LVSWI. When the cardiac work: KC ratio, defined as LVSWI divided by KC activity, was plotted against LVSWI, the correlation coefficient was 0.86. Cardiac work did not correlate with other metabolic pathways measured. Patients with a reduced LVSWI generated less cardiac work per unit of KC activity than those who had a normal or elevated LVSWI. These data indicate that a reduction in LVSWI below 40 grammeters/square meter (gm-m/m2) may be associated with either inefficient energy production, inefficient energy utilization, or both.

ISSN:0002-9629    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

ABSTRACT: Seven patients developed clinical features simulating myocardial ischemia less than 72 hours after 12 of 13 separate invenous 5-flourouracil administrations; 9 episodes were associated with chest pain, 3 with hypotension, 3 with ventricular tachycardia and 1 with cardiogenic shock. Left ventricular dysfunction was demonstrated by echocardiography in 5 separate episodes, 2 with interval improvement upon repeat echocardiograms. Pretreatment with nitrates and/or calcium channel blockers failed to prevent recurrence of cardiotoxicity during 5 of 6 repeat 5-fluorouracil administrations. Therapy with 5-fluorouracil is associated with cardiotoxicity simulating myocardial ischemia with left ventricular dysfunction. Pretreatment with coronary vasodilators may not prevent this phenomenon.

ISSN:0002-9629    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

ABSTRACT: Dobutamine is a sympathomimetic amine that was designed as an inotropic agent for use in congestive heart failure. Clinically, dobutamine increases cardiac output by selectively augmenting stroke volume, and this is associated with a decrease in total peripheral vascular resistance that is mediated, in part, by reflex withdrawal of sympathetic tone to the vasculature. This hemodynamic profile of dobutamine makes the drug of value in the management of low output cardiac failure. The inotropic activity of dobutamine has previously been attributed to selective stimulation of myocardial β1-adrenoceptors. However, recent studies from a number of laboratories indicate that the mechanism of action of dobutamine is substantially more complex. Dobutamine has the capacity to stimulate β1-, β2-, and α1- adrenoceptors in the cardiovascular system at doses that approximate those used clinically. It has recently been suggested that the inotropic activity of dobutamine results from combined β1- and α1-adrenoceptor stimulation in the myocardium, and that this activity could explain, at least in part, the inotropic selectivity of the compound. Furthermore, in the vasculature, the β2-adrenoceptor-mediated vasodilatory effect of dobutamine is exactly offset by the α1-adrenoceptor-mediated vasoconstrictor activity, such that net changes in blood pressure are minimal following the administration of dobutamine. It is concluded, therefore, that the hemodynamic profile of dobutamine in patients with congestive heart failure is derived from a unique and complex series of interactions with α-and β-adrenceptors in the cardiovascular system.

ISSN:0002-9629    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

ABSTRACT: The close relationship of Kaposi's sarcoma (KS) with other lymphoproliferative disorders is a poorly understood, but well documented, phenomenon. A case is presented of a 68-year-old woman with the classical form of cutaneous KS in whom disappearance of the lesions after treatment was shortly followed by the development of angioimmunoblastic lymphadenopathy, pursuing a fulminant course to death. Postmortem examination revealed diffuse involvement of the marrow, spleen, liver, and lymph nodes by the immunoblastic proliferation. The close association of these two conditions may represent more than a chance occurrence. The appearance of a constellation of nonspecific symptoms suggestive of a lymphoproliferative disorder in debilitated patients with KS should alert the physician to the possibility of the development of this rare complication.

ISSN:0002-9629    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

ABSTRACT: Polymorphonuclear leukocyte (PMN) aggregation and chemotaxis were studied in 27 patients with sickle cell disease (SCD). Pain-free patients with SCD had a significantly impaired aggregation response to stimulation with n-formylmethionyl-leucyl-phenylalanine (FMLP) with or without cytochalasin B (CB), compared with normal volunteers (p < 0.001). Patients with SCD in vasoocclusive crisis had PMN aggregation induced by FMLP with or without CB that was significantly increased compared with the cohort of pain-free SCD patients (p < 0.001). PMN from pain-free patients had normal chemotaxis, whereas patients in vasoocclusive crisis had a significant impairment in PMN chemotaxis. PMN chemotaxis was inversely related to the PMN aggregation response to FMLP with CB (r= −0.75). Thus, the PMN from pain-free patients with SCD appears to have normal or decreased “stickiness” and to develop increased stickiness during vasoocclusive crisis. The mechanisms responsible for these changes need further elucidation. Alterations in PMN function may be responsible, in part, for the increased risk of infection noted in individuals with SCD and may play a role in the development of the acute chest syndrome.

ISSN:0002-9629    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

ABSTRACT: A woman with sustained hypertension, facial roundness, hirutism, marked sweating, and generalized tremor was found to have a right adrenal pheochromocytoma. Elevated levels of serum cortisol, plasma ACTH, and serum catecholamines returned to normal after the tumor was removed. It was confirmed that enzymatically dispersed tumor cells produced ACTH and catecholamines concomitantly during in vitro incubation.

ISSN:0002-9629    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

ABSTRACT: A 65-year-old man manifested certain features of scleroderma several years before discovery of malignant thymoma. Following tumor resection, the signs and symptoms of scleroderma did not improve, and the patient experienced the abrupt onset of renal failure with malignant hypertension 7 months after the operation. The scleroderma renal crisis caused terminal renal failure, which was treated by chronic hemodialysis. This is the second reported case of thymoma associated with progressive systemic sclerosis (PSS). The authors suggest that thymoma and various immunologic disorders have a common etiologic factor which has not yet been found. This case emphasizes that thymectomy frequently has little effect on the course of the immunologic disease. The implications of the association of thymoma and PSS are discussed.

ISSN:0002-9629    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

ABSTRACT: An in-depth discussion of Classic Heat Stroke (CHS) and Exertional Heat Stroke (EHS) Syndromes occurred during morning report at a large metropolitan teaching institution during a New Orleans heat wave. The opportunity arose to compare the syndromes via case reports of two patients admitted the same day to the same housestaff teams. The physiology of the hyperthermic state, maladaptions predisposing the hyperthermic syndrome and current heat stroke management updates are reviewed in detail. This report should compel the reader to remain attentive to the subtleties and differences presented in life-threatening high-heat and humidity-related illnesses and how to act rapidly and prudently in management of the illnesses.

ISSN:0002-9629    

出版商:OVID    

年代:1987

数据来源: OVID