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Biomedical subjects

S Feld

Publications and source records attributed to S Feld.

At least 37 records · Page 2Linked to original sources
PubMed1995

Infarct salvage with liposomal prostaglandin E1 administered by intravenous bolus immediately before reperfusion in a canine infarction-reperfusion model.

BACKGROUND: Prostaglandin E1 (PGE1) inhibits leukocyte and platelet function and reduces infarct size during left atrial infusion. Intravenous liposomal PGE1 (TLC C-53) accelerates thrombolysis and prevents reocclusion in canine coronary thrombosis. We tested the hypothesis that intravenous TLC C-53 would attenuate reperfusion injury in a canine infarction-reperfusion model. METHODS AND RESULTS: Twenty-one open-chest dogs were randomized to receive a 10-minute intravenous infusion of either liposome diluent (placebo), free PGE1 (2 micrograms/kg), or TLC C-53 (2 micrograms/kg PGE1) after 2 hours of left anterior descending (LAD) occlusion just before reperfusion. Hemodynamic assessment, regional myocardial blood flow determination with radioactive microspheres, myocardial leukocyte infiltration by myeloperoxidase assay, and estimation of infarct size using triphenyl tetrazolium chloride staining were performed. Regional fractional shortening was measured with sonomicrometer crystals implanted in the midmyocardium. Infarct size as a percentage of the risk region was significantly reduced (P < .05) with TLC C-53 (37.9 +/- 17.4%) compared with PGE1 (56.7 +/- 13.9%) or placebo (58.0 +/- 9.9%) infusion. Infarct salvage with TLC C-53 was independent of collateral blood flow by ANCOVA. There was a dramatic reduction in myeloperoxidase activity in the infarct, risk, and border regions of dogs treated with TLC C-53 compared with placebo. Enzyme activity was also significantly reduced (P < .05) in the infarct zone with TLC C-53 (0.11 +/- 0.1 U/100 mg) treatment compared with PGE1 (0.38 +/- 0.3 U/100 mg). No significant differences in regional myocardial blood flow or myocardial function among treatment groups were identified, although there was a trend toward improved function in the TLC C-53 dogs. CONCLUSIONS: Bolus intravenous administration of TLC C-53 immediately before reperfusion results in reduced leukocyte infiltration and substantial infarct salvage. TLC C-53 mah be useful in limiting reperfusion injury during treatment of acute myocardial infarction.

Alprostadil↗
PubMed1995

Diffuse vasospasm following stenting of a free gastroepiploic artery graft: resolution with balloon angioplasty and intensive medical therapy.

Vasospasm following balloon angioplasty of gastroepiploic artery bypass grafts can be prevented or reversed with vasodilators. In our patient, stent deployment for ostial stenosis of a free gastroepiploic artery graft was accompanied by severe, diffuse spasm and a change in graft configuration that required both intensive medical therapy and balloon angioplasty for resolution.

Angioplasty, Balloon, Coronary↗
PubMed1995

Successful treatment of chronic total peripheral occlusions that failed conventional techniques using the stiff backend of the Glidewire.

The vast majority of failures of transcatheter interventions in patients with peripheral vascular disease are due to inability to cross the lesion with a guidewire. Although the use of the Glidewire has clearly improved the success rate, failures with especially chronic total occlusions still occur. We describe a new technique using the very stiff backend of the Glidewire, which we have found very successful, when conventional techniques fall in crossing highly resistant lesions.

Aged↗
PubMed1995

Non-visualized left anterior descending artery revealed on selective conus artery catheterization.

Cardiac catheterization of a man with severe angina and anterior ischemia on exercise testing with perfusion imaging demonstrated normal anterior wall motion resting left ventriculography, but failed to visualize the left anterior descending (LAD) or conus artery on left and right coronary angiography. Selective contrast injection of a large conus artery originating from a separate ostium in the right aortic sinus demonstrated extensive collateral circulation to an LAD occluded at its origin from the left main coronary artery, thus providing essential information for subsequent patient management.

Aged↗
PubMed1995

Aggressive interventional treatment of acute myocardial infarction. Lessons from the animal laboratory applied to the catheterization suite.

Myocardial necrosis progresses with the duration of coronary occlusion in the early stages of acute myocardial infarction. Prompt recanalization of the infarct-related artery resulting in effective and sustained reperfusion of jeopardized myocardium is the goal of modern therapy. Clinical thrombolysis trials have demonstrated a significant survival advantage for treated patients, but only a modest recovery of global or regional systolic left ventricular function. Accelerated regimens of administering currently available thrombolytic agents are associated with early coronary patency rates approaching 85%, although effective coronary perfusion is restored in only slightly better than one half of patients treated. Primary angioplasty without antecedent thrombolytic therapy has resulted in high patency rates with superior coronary flow when performed in some experienced centers. Treatment of cardiogenic shock requires immediate mechanical or surgical intervention to reestablish coronary perfusion often following placement of a circulatory assistance device. Future trends toward very early initiation of thrombolytic therapy, improvements in adjunctive therapy and advances in the noninvasive detection of recanalization should permit selective use of aggressive interventional therapy for failed thrombolysis in a minority of patients with acute myocardial infarction.

Angioplasty, Balloon, Coronary↗
PubMed1994

Enhanced thrombolysis, reduced coronary reocclusion and limitation of infarct size with liposomal prostaglandin E1 in a canine thrombolysis model.

OBJECTIVES: The purpose of this study was to test the hypothesis that liposomal prostaglandin E1 (TLC C-53) would result in more rapid thrombolysis, less reocclusion and smaller infarct size when administered with heparin and streptokinase in a canine thrombolysis model. BACKGROUND: In experimental animals, prostaglandin E1 has been shown to augment thrombolysis, improve coronary flow and reduce infarct size when infused directly into the left atrium. TLC C-53 is a stable preparation of prostaglandin E1 bound by phospholipid microspheres that produces fewer adverse hemodynamic effects during intravenous use. METHODS: To investigate the effects of TLC C-53 on coronary patency and infarct salvage, we studied 30 conditioned open chest dogs. After coil-induced left anterior descending coronary artery occlusion and 1 h of clot maturation, the dogs were randomly assigned to receive a 10-min intravenous infusion of either TLC C-53 (2 micrograms/kg body weight) or placebo. Both groups then received intravenous heparin and streptokinase. Hemodynamic variables and Doppler coronary flow were monitored, and myocardial blood flow was determined using radioactive microspheres. Infarct size was assessed with triphenyltetrazolium chloride staining. RESULTS: Thrombolysis time was accelerated from 79 +/- 38 to 47 +/- 9 min (mean +/- SD), and coronary patency was greater (100% vs. 50%) with TLC C-53 than with placebo (p < 0.05). Moreover, for arteries that recanalized, coronary Doppler flow and myocardial perfusion were more severely impaired with placebo. Infarct size as a percent of the area at risk was higher (p < 0.05) with placebo (51 +/- 15%) than with TLC C-53 (33 +/- 14%). Neutrophil infiltration into ischemic myocardium determined by myeloperoxidase assay was also significantly greater in the placebo group. CONCLUSIONS: TLC C-53 administered intravenously before thrombolytic therapy resulted in a significant acceleration of thrombolysis time, improvement in coronary patency and blood flow during reperfusion and a reduction in infarct size.

Alprostadil↗
PubMed1994

Differential effects of synchronized coronary sinus retroperfusion on regional myocardial function during brief occlusion of the left anterior descending and circumflex coronary arteries.

To test the hypothesis that coronary sinus retroperfusion would preserve regional myocardial function during either left anterior descending or circumflex occlusion, sonomicrometer crystals were implanted in the midmyocardium of five chronically instrumented dogs. Regional fractional shortening was measured during 5 min of coronary occlusion with and without retroperfusion. Percent fractional shortening in the left anterior descending region fell from 18% at baseline to -4%(dyskinesis) after 3 min of left anterior descending occlusion. With coronary sinus retroperfusion, the percent fractional shortening declined from 16% at baseline to 0 (akinesis) during occlusion. A modest but significant improvement in percent fractional shortening in the ischemic region during left anterior descending occlusion occurred with retroperfusion (p < .05). By contrast, no amelioration of ischemic dysfunction occurred with retroperfusion during circumflex occlusion. Coaxial flow into the great cardiac vein during retroperfusion may provide preferential protection to ischemic myocardium supplied by the left anterior descending coronary artery. However, it is unlikely that the modest degree of improvement in regional function observed during acute left anterior descending occlusion would be mechanically important in the presence of significant ischemic dysfunction.

Animals↗
PubMed1994

Moderating effects of prior social resources on the hospitalizations of elders who become widowed.

In a prospective design, the effects of social resources before widowhood on changes in subsequent hospitalizations were compared for 86 married elders who became widowed over a 2-year period and 86 matched elders who remained married. Subjects were from the Established Populations for Epidemiologic Studies of the Elderly (Duke). Hospitalizations were used as an indicator of a serious health outcome whose report was unlikely to be biased by a widowed person's emotional state. The hypothesis that perceptions of inadequate social support from persons other than the spouse would exacerbate the effects of bereavement on hospitalizations was supported for elders who lacked close friends with whom to talk about private matters while still married; believing that no relative would provide such support and dissatisfaction with support tended to have the same effect. Inadequacies in social embeddedness (few contacts with friends, relatives, or children and being childless) had no significant moderating or main effects on change in hospitalizations.

Aged↗
PubMed1992

Familial cardiomyopathy with variable hypertrophic and restrictive features and common HLA haplotype.

We describe a familial cardiomyopathy affecting three generations of family members with similar electrocardiographic abnormalities and human leukocyte antigen (HLA) haplotype. Autopsy findings in two of our patients were diagnostic of hypertrophic cardiomyopathy, although surviving affected members do not show ventricular hypertrophy on echocardiography. One patient's echocardiogram revealed giant atria in the absence of ventricular hypertrophy, suggesting a restrictive form of cardiomyopathy. In this kindred, an HLA haplotype appearing in affected, but not in healthy, family members may predict occurrence of disease during its presymptomatic phase in subsequent generations.

Adolescent↗
PubMed1991

Symptomatic hyponatraemia due to inappropriate antidiuretic hormone secretion following minor surgery.

A rare case of the syndrome of inappropriate antidiuretic hormone secretion occurring after minor surgery is presented. A ten-year-old, previously healthy boy underwent general anaesthesia for detorsion and right orchiopexy. Throughout the operations, which lasted for one hour, he received 120 ml Ringer's lactate solution. The immediate postoperative period was uneventful. Twenty-two hours postoperatively he was found unconscious with generalized tonic-clonic seizures. Simultaneously obtained serum sodium concentration (121 mEq.L-1) serum osmolarity (265 mEq.L-1), urine sodium concentration (87 mEq.L-1) and urine osmolarity (525 mEq.L-1) suggested inappropriate antidiuretic hormone secretion which was confirmed by an elevated serum arginine-vasopressin (AVP) level of 14.5 pcg.ml-1 (normal 1-5 pcg.ml-1) measured by radioimmune assay. He was treated with a single iv dose of 30 mg furosemide and fluid restriction, which produced a gradual increase of his serum sodium concentration to normal within two days. He was well during the remainder of his hospitalization.

Child↗
PubMed1991

Impaired water homeostasis following mixed carbamazepine and phenobarbital overdose.

Both carbamazepine and phenobarbital are known to have antidiuretic properties when administered chronically. We describe a case of acute impairment of body water homeostasis following mixed drug overdose with carbamazepine and phenobarbital. Serum carbamazepine concentrations correlated with alternating states of diuresis and antidiuresis. We recommend close monitoring of fluid and electrolyte status in carbamazepine overdose.

Adult↗
PubMed1990

[Ceftriaxone or combined cefazolin-gentamicin for complicated urinary tract infections].

40 seriously ill patients with complicated urinary tract infections were randomly assigned to receive either a single daily dose of ceftriaxone or combined therapy with cefazolin and gentamicin administered every 8 hours. The groups were of equal size, similar in age (both averaged 75 years) and the sex ratio was about 1:1 in each group. 32.5% had proven bacteremia and the overall mortality was 17.5%. Both regimens were similarly effective in terms of mortality, duration of fever (3.0-3.1 days), and sterilization of the urine prior to discharge from hospital. However, the single daily dose of ceftriaxone was much more convenient to administer.

Aged↗
PubMed1986

Nocardia brasiliensis skin infections.

Nocardia brasiliensis skin infections were diagnosed in three patients (two with mycetoma and one with lymphocutaneous syndrome) in our hospital during the last 6 years. The mycetomas were detected in otherwise healthy Yemenite immigrants who had acquired their infection while in Yemen. The patient with the lymphocutaneous syndrome--a man with well-controlled diabetes mellitus--acquired his illness in Israel. N. brasiliensis appears to be more common in our region than previously believed. This organism should be considered a possible etiologic agent in some cases of chronic unresponsive skin infection.

Aged↗