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Biomedical subjects

J Shani

Publications and source records attributed to J Shani.

At least 73 records · Page 4Linked to original sources
PubMed1991

Exercise-induced ventricular tachycardia in association with a myocardial bridge.

Sustained ventricular tachycardia induced by exercise is uncommon. This is a report of a patient who has a positive exercise test at a high level of exercise. The electrocardiogram has classic ischemic ST depressions. Following the appearance of these ST depressions, the patient developed ventricular tachycardia at a rapid rate. Workup that included an echocardiogram and cardiac catheterization revealed myocardial bridging of the left anterior descending artery as the only structural abnormality. Electrophysiologic studies revealed the patient to have ventricular tachycardia only with isoproterenol (Isuprel) infusion.

Adult↗
PubMed1990

Assay of suntan lotions for the carcinogenic, non-volatile N-nitrosamine N-nitrosodiethanolamine.

N-nitrosodiethanolamine (NDELA) is a carcinogenic, non-volatile nitrosamine that has been shown to pass readily through the skin of animals and humans. It has often been found as a contaminant in cosmetics. Twenty different suntan lotions, available in Israel, both liquids and creams, were analyzed for NDELA content. Most products contained undetectable or trace levels, but 3 were found to be contaminated with as much as 27 ppb of the nitrosamine. Continual use of such products, especially by small children and infants, may significantly increase their exposure to NDELA.

Carcinogens↗
PubMed1990

Free radical scavenging by ethanol extract of propolis.

The free radical scavenging ability of an ethanolic extract of propolis (EEP) was demonstrated by electron spin resonance spectroscopy, when 2,2-diphenyl-1-picrylhydrazyl (DPPH) was treated with increasing concentrations of EEP. It was shown that the DPPH signal intensity was inversely related to the EEP concentration and to the reaction time. It is assumed that the ability of components in EEP to donate a hydrogen atom is responsible for the lowering of the DPPH-EEP signal, and reflect the anti-oxidative nature of EEP.

Antioxidants↗
PubMed1990

R- and S-wave amplitude changes with acute anterior transmural myocardial ischemia. Correlations with left ventricular filling pressures.

The value of R- and S-wave amplitude changes as electrocardiographic (ECG) markers of myocardial ischemia and dysfunction was evaluated using coronary angioplasty as a model of acute transmural ischemia and ST segment elevation. Hemodynamic data and 12-lead ECGs were recorded at baseline and during coronary occlusion in 34 patients with left anterior descending artery angioplasty. In the precordial leads V1 through V4, the sum of R-wave amplitude increased in 17 patients, was unchanged in ten, and decreased in seven; the sum of S-wave amplitude decreased in 33 patients (including two patients with complete loss of S wave) and increased in one. Mean R-wave change was 2.7 +/- 6.2 mm, mean S-wave change was -12.9 +/- 9.0 mm, and mean precordial ST elevation was 12.5 +/- 8.7 mm. Absolute R-wave change correlated directly with ST elevations (p = .013), while S-wave change correlated inversely (p less than .007). Only ST elevations correlated with changes in pulmonary capillary wedge pressure (PW) (p less than .007). In the precordial lead with maximum ST elevations, only R-wave changes correlated with ST elevations (p = .002), and both R-wave changes and ST elevations correlated with changes in PW (R:p = .027; ST:p = .007). The presence of large increases in R waves or decreases in S wave, or of high-magnitude ST elevations identified patients with the highest elevations in PW. In conclusion, decreases in S waves and, less commonly, increases in R waves are seen with diagnostic ST elevations and may have some limited clinical value. The correlation between magnitude of acute anterior ST elevations and changes in left ventricular filling pressures may have important clinical consequence.

Acute Disease↗
PubMed1990

Anti-oxidant property of ethanolic extract of propolis (EEP) as evaluated by inhibiting the chemiluminescence oxidation of luminol.

Ethanolic extract of propolis (EEP) has remarkable medical properties, including protection of mice against gamma irradiation. Its anti-oxidative effect has been attributed to its radical scavenging ability. This manuscript demonstrates the ability of increasing amounts of EEP to inhibit luminol-H2O2 chemiluminescence in vitro, and suggests that its anti-oxidative capacity is partly due to its high content of flavonoids.

Antioxidants↗
PubMed1990

Correlations between uptake of technetium, calcium, phosphate, and mineralization in rat tibial bone repair.

Technetium-99m-(99mTc) phosphates are extensively used for detection of bone formation and resorption. The present is a study of 99mTc incorporation during bone remodeling. Uptake of 99mTc-labeled phosphate was studied in an animal model of primary osteogenesis following tibial marrow injury and incorporation was correlated to that of calcium-47 (47Ca), phosphorus-32 (32P), and with matrix vesicle calcification. Isotope uptake on Day 6 in the whole bone was increased compared to controls. On this day, an increase in vesicular diameter and distance from the calcified front was previously observed. Technetium-99m-labeled phosphates were detected only in the organic phase. Phosphorus-32 and 47Ca were detected in both organic and inorganic phases. It is suggested that 99mTc serves as a specific marker to the anabolic phase of remodeling. Increased incorporation of 99mTc during bone healing indicates enhanced organic matrix formation and not calcification.

Animals↗
PubMed1989

Effects of occlusion of the left anterior descending coronary artery during angioplasty on right-sided cardiac pressures and electrocardiographic changes.

Controversy persists regarding the presence and extent of right ventricular involvement with acute anterior injury. Also unclear are the incidence and significance of ST elevations in the right-sided leads in acute left anterior descending artery occlusion. Baseline and coronary occlusion hemodynamics and 15-lead electrocardiograms (addition of RV3 through RV5) were recorded in 42 patients during 32 left anterior descending and 13 right coronary artery angioplasties. The right coronary and left anterior descending artery angioplasties had similar baseline right and left ventricular hemodynamics, as well as identical right atrial to pulmonary wedge pressure ratios (0.51 right coronary vs 0.51 left anterior descending). Whereas the right coronary and left anterior descending occlusions produced similar elevations in right ventricular filling pressures, the left anterior descending occlusions produced greater elevations in left ventricular filling pressures. The right atrial to pulmonary wedge ratio increased with right coronary occlusions, but was unchanged with left anterior descending occlusions (0.79 right vs 0.46 left, p less than or equal to 0.0001). Presence of right-lead ST elevations in 10 left anterior descending occlusions did not con-note increased right ventricular filling pressures, but did suggest increased left ventricular ischemia and dysfunction. In conclusion, right ventricular dysfunction, as manifested by increased filling pressures, is seen with both right coronary and left anterior descending occlusions. Although it is the predominant abnormality in right coronary occlusions, in left anterior descending occlusions it is proportional to left ventricular dysfunction. ST elevations in a right lead with left anterior descending occlusions do not constitute a marker for increased right ventricular dysfunction.

Angioplasty, Balloon↗
PubMed1989

Noninvasive monitoring of drug biodistribution and metabolism: studies with intraarterial Pt-195m-cisplatin in humans.

We have performed a comparative evaluation of systemic (i.v.) and intraarterial (i.a.) cisplatin by using a trace dose of the radiolabeled form of this drug [( 195mPt]cisplatin) to monitor the drug's biodistribution by dynamic scintigraphic imaging. We have analyzed the drug's metabolism using a compartmental model both following i.a. and i.v. administration in patients with gliomas. Significantly larger amounts of radioactivity (up to 10 times higher than in the uninvolved brain) were measured in tumors following i.a. administration, whereas the differential localization following i.v. drug administration was, at best, only twofold that of the uninvolved brain. On the other hand, no significant differences could be detected in the pharmacokinetics of either free cisplatin or platinated proteins in blood. The washout slope in tumors following i.a. administration may be an indicator of the higher local concentration of free cisplatin; no such washout could be observed in tumors following i.v. administration. The present noninvasive methods may help document the amount and the rate of (active) drug deposition at the desired target site. They may also assist in monitoring, prospectively and/or, on line, the probable effect of chemotherapy in an individual patient. In turn it may lead to novel methods for optimizing chemotherapeutic effectiveness at specific tumor-bearing sites and in defined treatment protocols.

Cisplatin↗
PubMed1989

Pericardial effusion early in acute myocardial infarction.

The incidence and significance of pericardial effusions early in acute myocardial infarction remain unclear. Using two-dimensional echocardiography, 172 patients with an acute myocardial infarction were evaluated within 72 h of presentation. Thirty patients (17%) had a pericardial effusion (29 small, 1 moderate) while 142 (83%) did not. No patient developed cardiac tamponade or required pericardiocentesis. Patients with pericardial effusions had higher peak creatine kinase as compared to patients without effusions (2036 +/- 1466 vs. 1483 +/- 1241, p less than 0.05) and a greater number of aneurysms (20% vs. 6%, p less than 0.05). In-hospital mortality was higher in the patients with pericardial effusions (10% vs. 2%, p less than 0.05). In conclusion, pericardial effusions are common in the early AMI period but are generally small and hemodynamically insignificant. They are associated with larger infarcts and greater mortality.

Aged↗
PubMed1989

Anticipation of bypass surgery: can it induce silent myocardial ischemia?

Psychological stress has been demonstrated to induce myocardial ischemia. To determine whether stressful events before a coronary artery bypass grafting procedure precipitate myocardial ischemia, silent or symptomatic, and whether this can have an effect on the prognosis, 26 patients were evaluated before a bypass operation with continuous Holter monitor recording. Specific events monitored were signing surgical consent, receiving preoperative medications, shaving and preparing, and transfer to the operating room. A positive Holter result was defined as an ST segment depression of 1 mm or more lasting one minute or longer. Six patients (23%) were found to have one or more episodes of substantial ST segment depression, with a total of ten episodes lasting 208 minutes recorded. All episodes were silent and not associated with an increase in mean heart rate. The majority of episodes occurred randomly, although three episodes did occur between 5 and 6 AM at the time of transport to the operating room. This appeared to be related more to the circadian rhythm than to the stress of transport. No perioperative or postoperative myocardial infarctions occurred, and all patients were alive at 30 days. In conclusion, silent myocardial ischemia present in the immediate preoperative period does not appear to be related to specific preoperative events. Frequency of early morning ischemia may warrant changes in the medication schedule to provide additional protection during these hours.

Aged↗
PubMed1989

Compartmental biodistribution of a monoclonal antibody against human lung adenocarcinoma grown in athymic mice.

The biodistribution of the radioiodinated monoclonal antibody KS1/4 and of its F(ab) and F(ab')2 fragments were studied in tumor-bearing nude mice. Intravenous administration of the intact antibody resulted in the highest tumor retention and tumor/blood ratios. No metabolites or antigen-antibody conjugates were detectable, in serum, by HPLC analyses. Reasonable correlations were obtained between the estimated time-course of KS1/4 and experimental biodistribution data using an eight-compartment linear radiopharmacokinetic model, suggesting that such models may be useful in predicting the biodistribution and effective targeting of this monoclonal antibody.

Adenocarcinoma↗
PubMed1989

Full dose subcutaneous heparin therapy.

Anticoagulation is used extensively for the treatment and prevention of thromboembolic disease. Full dose anticoagulation with heparin is usually administered intravenously via continuous 24-hour infusion to avoid complications with intermittent intravenous administration. Continuous intravenous therapy is costly and cumbersome for nurses and patients. Subcutaneous administration of heparin in full dosage offers an attractive therapeutic alternative. This study examines the safety, efficacy, and cost considerations of this form of therapy. Fifteen patients admitted to the hospital for myocardial infarction were evaluated. After the patients were transferred from the cardiac intensive care unit, intravenous heparin was discontinued, while therapeutic anticoagulation was maintained via the subcutaneous route. Complications were limited to local hematoma formation. A cost comparison revealed substantial savings with subcutaneous administration.

Aged↗
PubMed1988

Septal rupture: effect of oxygen administration.

A patient with interventricular septal rupture as a complication of myocardial infarction was studied to determine whether varying the concentration of inspired oxygen would alter the magnitude of intracardiac shunt. A significant correlation was found showing that high concentration of inspired oxygen results in increased left to right shunting probably due to systemic vasoconstriction and pulmonary vasodilatation.

Combined Modality Therapy↗
PubMed1988

Relationship between location of chest pain and site of coronary artery occlusion.

Chest pain characteristics and site of coronary artery occlusion were evaluated in 148 patients having single-vessel coronary angioplasty and in 95 patients having double-vessel angioplasty. The locations of chest pain included substernal and left precordium, right precordium and epigastric. The possible sites of pain radiation were limited to neck/jaw, left arm, right arm, and interscapular. The patient described whether or not the pain was typical of previous angina, and the presence of ST segment deviation was noted to be certain that ischemia was present. The analysis showed that the occluded artery could not be reliably identified. However, it was possible to say which artery was most likely not diseased. Patients presenting with substernal or left chest pain with radiation to the left arm had a less than 10% chance of having right coronary artery disease. A patient presenting with epigastric pain radiating to the neck or jaw had a less than 13% chance of having left anterior descending disease. It is concluded that in patients with single- and double-vessel coronary disease, there is some relationship between chest pain pattern and disease location.

Angina Pectoris↗
PubMed1988

Salivary gland function in patients on chronic lithium treatment.

Salivary gland function was studied in 14 manic-depressive patients treated with lithium carbonate (Li) for 4 to 120 months. Function level was evaluated by means of sialometry, dynamic salivary scintigraphy, and sialography. Daily Li dose, serum Li concentration, duration of Li therapy, and caries activity index were correlated with the salivary function parameters studied. Hyposalivation was noted in 71% of the patients, showing good correlation with the scintigraphic (r = 0.94) and sialographic (r = 0.87) results. Duration of Li therapy was poorly correlated with the degree of salivary gland dysfunction and with the caries activity index, whereas the correlation between duration of therapy and each of the three salivary function parameters was erratic. Because four of the patients exhibited normal salivation, we suggest that there are some additional factors (e.g., genetic or thyroid function level) that might be involved in salivary dysfunction connected with Li therapy.

Adult↗
PubMed1988

The clinical value of quantitative dynamic scintigraphy in salivary gland disorders.

Salivary gland scintigraphy with [99mTc]pertechnetate was performed in a group of 11 subjects without any known salivary pathology, and in a group of 12 xerostomic patients. Time-activity curves, normalized to background, were generated for each of the four major salivary glands in both groups, and averaged into single curves, representing the function of each gland. Comparing the two sets of curves (patients vs controls) demonstrates that utilizing our "normalization" approach enables one not only to determine whether one group of dynamic curves is significantly different from another, but to decide which of the glands are normal and which are malfunctioning. The sensitivity, specificity, accuracy and predictive values of this procedure are all above 0.90.

Adult↗