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Biomedical subjects

J Shani

Publications and source records attributed to J Shani.

At least 55 records · Page 3Linked to original sources
PubMed1994

Postprandial angina pectoris: clinical and angiographic correlations.

OBJECTIVES: This study was designed to determine the severity of coronary artery disease in patients with postprandial angina pectoris. BACKGROUND: Postprandial angina is a manifestation of coronary artery disease. Although seen in clinical practice, very little has been published about the syndrome, and no anatomic correlations have been described. METHODS: Questionnaires were given to 408 patients with chest pain and objective evidence of ischemia. Thirty-five patients (8.6%) were identified as having postprandial angina (Group A). The other 373 patients (Group B) had nonpostprandial angina and served as the control group. Coronary angiography was performed in all patients, and the results were analyzed. RESULTS: Postprandial angina was observed predominantly in men (91% vs. 66%, p = 0.0036). It was associated with a high incidence of rest angina (83% in Group A vs. 51% in Group B, p = 0.0005) and a very high incidence of left main (34% vs. 10%, p = 0.0001) and three-vessel (82% vs. 54%, p = 0.001) coronary artery disease. The ejection fraction was lower as well in these patients (0.39 vs. 0.47, p = 0.046). Postprandial angina occurred at rest and on exertion, most commonly after dinner. CONCLUSIONS: Postprandial angina is a likely marker of severe coronary artery disease and should be considered an indication for coronary angiography.

Aged↗
PubMed1994

Structure-activity relationship in the ability of flavonols to inhibit chemiluminescence.

Fourteen flavonoids were evaluated for their ability to inhibit chemiluminescence, either of neutrophils that had been briefly exposed to both luminol and phorbol-myristate acetate or to an enzymatic system with H2O2, luminol and horseradish peroxidase. Using chemiluminescence as the quantitative parameter, it can be concluded that the hydroxyl group in position 3 of the flavonols is vital for their inhibitory effect, and that two hydroxyl groups on the phenyl ring are optimal for such an effect. It was also noted that the C2-C3 double bond is essential for the flavonols' anti-oxidative effect. It is suggested that the ability of flavonols to suppress chemiluminescence is reciprocally correlated with their lipophilicity.

Animals↗
PubMed1993

Mechanical manipulation of thrombus: coronary thrombectomy, intracoronary clot displacement, and transcatheter aspiration.

Recanalization of occluded arteries during acute myocardial infarction has been proven to prolong life and improve left ventricular function. Patients who could not receive thrombolytic therapy for failed thrombolysis and/or angioplasty were treated by mechanical manipulation of the thrombus. Three techniques were used: transcatheter aspiration, clot displacement, and thrombectomy. Five patients in shock had the thrombus aspirated from the left main and right coronary arteries. Eight patients had the clot pushed by the balloon from the mid-left anterior descending (LAD) to the apical LAD in order to reduce the area of ischemic myocardium, and 13 patients underwent a thrombectomy of the right coronary artery. These procedures enjoyed a high rate of success in reestablishing patency and a favorable long-term clinical and angiographic follow-up. Although the applicability and role of these interventions in acute myocardial infarction are not yet defined, we conclude that they are feasible and have an acceptable success and complication rate.

Aged↗
PubMed1993

Coronary atherectomy versus angioplasty: the CAVA Study.

Directional coronary atherectomy was developed with the hope that it would lower the risk of acute closure and restenosis by leaving a larger smoother lumen and fewer dissections than angioplasty. To evaluate this hypothesis, we compared the clinical and angiographic results of directional coronary atherectomy with those of percutaneous transluminal coronary angioplasty in well-matched groups. We studied 126 consecutive atherectomies and 127 angioplasties performed on similar lesions. Procedural results were evaluated with regard to dissections, complications, acute closure, and residual stenosis. Each patient's clinical course was followed, and each patient was contacted at 6 months for evaluation of recurrent angina, need for repeat catheterization, and angiographic rate of restenosis. Baseline clinical and angiographic characteristics of the two groups were well matched and met the criteria established as being appropriate for atherectomy. The angiographic success rate was 98% after angioplasty and 99% after atherectomy. There were fewer dissections after atherectomy (13%) compared with the number after angioplasty (22%; p = 0.03). Residual stenosis was 8.3 +/- 9% after atherectomy compared with 15 +/- 12% after angioplasty (p = 0.0001). However, there were more complications after atherectomy (p = 0.03). There was no significant difference between the two groups in the recurrence rate of angina or in the angiographic restenosis rate at 6 months. It was concluded that when lesion characteristics and vessel size are appropriate for atherectomy, the procedural success rate of either atherectomy or angioplasty is extremely high. Although atherectomy leads to a larger residual lumen and fewer dissections, the complication rate after atherectomy is higher than that after angioplasty. There is a trend toward more occlusions after atherectomy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Coronary angiography with 5 French diagnostic catheters may miss an ostial left main stenosis.

Critical ostial left main disease may lead rapidly to sudden death and is, therefore, of paramount importance to diagnose. While the number of cardiac catheterizations is increasing, government and third party reimbursement sources are imposing pressure to perform more studies in an outpatient setting, as the economic resources for medical procedures are shrinking. Outpatient cardiac catheterization requires the patient to ambulate within several hours after the procedure. In order to allow patients to safely ambulate early after their procedures, 5 French catheters are often used (whether the femoral or brachial approach is used) rather than the standard 7 French catheters. We describe a patient with an ostial left main stenosis that was not visualized when coronary arteriography was performed using a diagnostic 5 French catheter. Selective intubation of the left main coronary artery was easily achieved without damping of the pressure tracing. Selective coronary angiography did not demonstrate the ostial stenosis, and there appeared to be a normal amount of contrast refluxing into the aortic root. When the patient returned for an angioplasty and a guiding angiogram was performed with an 8 French catheter, an ostial stenosis was evident with coronary angiography.

Aged↗
PubMed1993

Synergistic effect of ethanolic extract of propolis and antibiotics on the growth of staphylococcus aureus.

Ethanolic extract of propolis (EEP), known to possess marked antibacterial activity, was incubated with 8 different common antibiotics in culture medium containing a fixed amount of a standard strain of Staphylococcus aureus. The antibiotic compounds used were: penicillin G, doxycycline, streptomycin, cloxacillin, chloramphenicol, cefradine, ampicillin and polymyxin B. They were used in varying levels, ranging between 0.000005-125.0 micrograms/ml or units, resp. Firstly, their minimal inhibitory concentrations were established in the absence of EEP, than EEP was added in concentrations up to 600 micrograms/ml. EEP had a marked synergistic effect on the antibacterial activity of streptomycin and cloxacillin, and a moderate synergistic effect on the others, except ampicillin.

Anti-Bacterial Agents↗
PubMed1993

Uptake and biodistribution of technetium-99m-MD32P during rat tibial bone repair.

The present study was carried out in order to test the hypothesis that intravenously injected Tc-MDP separates into its technetium and methylene diphosphonate components in the bone, and that the technetium is preferentially taken-up by the newly-formed osteoid, while the methylene diphosphonate is taken up by the forming mineral. Uptake of Tc-MDP was studied in a rat model of primary bone formation following tibial bone marrow ablation. Each of five radiopharmaceuticals (99mTCO4, 99mTc-MDP, Tc-MD32P, 99mTc-MD32P or MD32P) was injected and their uptake was followed in the whole bone as well as in the organic and inorganic phases of the bone. Irrespective of the radionuclides injected, 99mTc was always taken-up preferentially by the organic phase, while the 32P was preferentially taken-up by the inorganic phase. When 99mTcO4 was injected, it was not taken up by the bone at all. These results indicate that the increased incorporation of 99mTc, when administered as 99mTc-MDP during bone healing, reflects an enhancement in the formation of the organic matrix and not of the calcification process. The study also suggests that the 99mTc-MDP dissociates into its technetium and methylene diphosphonate moieties, which are then adsorbed onto the organic and inorganic phases respectively.

Animals↗
PubMed1992

Symptomatic angina secondary to coronary-subclavian steal syndrome treated successfully by percutaneous transluminal angioplasty of the subclavian artery.

Subclavian artery stenosis causing severely symptomatic angina in a patient with a previous left internal mammary artery bypass to the left anterior descending artery was treated successfully with percutaneous transluminal angioplasty. Baseline arteriography clearly revealed subclavian and coronary steal by evidence of competitive flow of nonopacified blood from the left vertebral artery. Although there was a difference of only 15 mm Hg between the right and left brachial arteries, there was a palpable difference in the upstroke of these pulses. The stenosis in the subclavian artery was successfully dilated with percutaneous transluminal angioplasty. Angiographic evidence of subclavian steal resolved following balloon dilatation, and the patient's angina was completely resolved.

Aged↗
PubMed1992

Early postoperative occlusion of a left internal mammary artery bypass graft with subsequent restoration of patency.

Total occlusion of a left internal mammary artery (LIMA) bypass graft is a rare complication, and reversal of a documented occlusion has not been reported. This is a case of an early postoperative occlusion of a LIMA graft that was found to be patent 4 months later. A patient with three vessel disease (including a moderate lesion in the proximal left anterior descending artery and a severe lesion in its mid-portion) underwent coronary artery bypass grafting with a LIMA to the mid-left anterior descending artery (LAD) and saphenous vein grafts to the right coronary and left circumflex arteries. Coronary angiography 3 months after surgery revealed a totally occluded internal mammary artery and saphenous vein grafts. The patient then underwent a successful angioplasty of the more distal lesion in the LAD. She subsequently returned with recurrent angina. Repeat coronary angiography revealed rapid progression of the disease in the proximal LAD with the more distal angioplasty site being widely patent. Selective arteriography of the internal mammary artery at that time revealed a patent vessel. Thus, the internal mammary graft is a physiologically active conduit that is dependent on flow dynamics. Competitive flow through the nonobstructive native LAD in combination with impedance of flow through the internal mammary artery due to a severe lesion in the LAD distal to the anastomosis led to a functionally occluded LIMA. When the obstruction in the proximal LAD progressed and the distal obstruction was successfully angioplastied, the flow dynamics in the internal mammary improved, allowing for its dilatation and restoration of patency.(ABSTRACT TRUNCATED AT 250 WORDS)

Constriction, Pathologic↗
PubMed1992

Giant T-wave inversion in patients with acute coronary insufficiency.

We have observed an electrocardiographic (ECG) pattern of deep T-wave or "giant T wave" inversion in patients with acute coronary insufficiency. We reviewed the ECGs of 936 patients admitted to our coronary care unit during a one-year period. We found the pattern of giant T-wave inversion was present in nine patients (1 percent). We examined the echocardiograms of all of these patients and we analyzed the coronary angiograms on the seven patients in whom it was performed. We found that giant T-wave inversion was usually found in patients with stenosis in the left coronary system. In addition, the majority of these patients also had echocardiographic evidence of left ventricular hypertrophy. We conclude that the high frequency of a partially patent vessel in the left coronary system suggests that this ECG pattern may be useful in identifying patients who might benefit from coronary revascularization.

Acute Disease↗
PubMed1992

Effects of coronary angioplasty on plasma platelet-activating factor in man.

Platelet activating factor (PAF) is a mediator of ischemia and reperfusion-induced tissue damage which was found to be synthesized in culture by endothelial cells. We hypothesized that PAF levels may be increased in the coronary system following coronary angioplasty. PAF levels were measured in the great cardiac vein of 16 patients before, during and following angioplasty of the left anterior coronary artery. PAF concentration was significantly higher in the cardiac vein than in the peripheral circulation at all time points. Interestingly, while PAF levels tended to decrease in the periphery they tended to increase in the coronary system over time. We conclude that PAF levels are higher in the coronary system than in the peripheral circulation in patients undergoing coronary angioplasty and that PAF may be released into the coronary artery following the procedure.

Adult↗
PubMed1991

Two hugging balloons at high pressures successfully dilate a lesion refractory to routine coronary angioplasty.

A small portion of lesions are refractory to coronary angioplasty even when very high pressures are used. This leads to a failed angioplasty and emergent bypass surgery. We successfully attempted the technique of hugging balloons or two polyethelene terephthalate (PET) balloons inflated simultaneously side by side which successfully dilated a lesion which would not dilate using standard techniques. This technique successfully dilated the lesion as the geometry of two balloons inflated side by side is different from one balloon. Two balloons inflated side by side consists of two outer semi-circles and a central trapezoidal square area. This altered geometric configuration may be important in successfully dilating a lesion refractory to standard dilating techniques. Higher pressures can be attained with smaller balloons as the burst pressure is higher in smaller balloons compared to larger balloons.

Aged↗