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Biomedical subjects

N Shapira

Publications and source records attributed to N Shapira.

At least 37 records · Page 2Linked to original sources
PubMed1989

Low glycemic index foods and reduced glucose, amino acid, and endocrine responses in cirrhosis.

Carbohydrate intolerance is common in patients with cirrhosis. The aim of the present study was to determine whether the beneficial metabolic effects of low glycemic index diets observed in noncirrhotic diabetics also occurred in patients with cirrhosis. Therefore, for one day, five patients with cirrhosis were fed diets in which low glycemic index foods were substituted, replacing those which produced higher blood glucose rises. Reduction in the estimated glycemic impact of the diet by approximately 30% reduced the mean incremental blood glucose level over the day by 40 +/- 5% (p less than 0.001). Measurement at breakfast of amino acid, insulin, and gastric inhibitory polypeptide profiles confirmed a reduction of similar magnitude. No change was seen in pancreatic glucagon, whereas enteroglucagon levels tended to be higher. In view of these findings and the possible long-term benefits of chronic reduction of hyperinsulinism and alteration in amino acid metabolism, this approach to dietary management of cirrhosis warrants further consideration.

Aged↗
PubMed1988

Adjunct endarterectomy of the left anterior descending coronary artery.

During a three-year period, complete revascularization of diffusely diseased left anterior descending (LAD) coronary arteries was accomplished by extensive endarterectomy in conjunction with bypass grafting in 37 patients in whom conventional bypass was not feasible. This group constituted 7.0% of all patients undergoing nonemergency coronary revascularization during this period. The left internal mammary artery was used to bypass the endarterectomized LAD artery in 22 patients. There was 1 (2.7%) operative death and 1 perioperative myocardial infarction. At follow-up, which was 100% with a mean of 41.4 months, all endarterectomy patients were in New York Heart Association Functional Class I or II. Twenty-four endarterectomy patients underwent first-pass radionuclide angiographic stress testing 20 months after operation. Twenty patients (83%) had excellent postoperative exercise tolerance, achieving 5 to 7 mets on treadmill testing. Left ventricular functional reserve was preserved, as evidenced by an increase of global ejection fraction from 48 +/- 15% at rest to 59 +/- 18% (p less than 0.005) with exercise. A similar increase was measured in the proximal and distal anterior wall segmental ejection fractions. No difference in response to exercise was found between the internal mammary artery and the vein graft groups. Thus, complete revascularization of the diffusely diseased LAD artery can be accomplished by adjunct endarterectomy without added morbidity or mortality and with excellent functional results.

Adult↗
PubMed1988

The use and interaction of permanent pacemakers and the automatic implantable cardioverter defibrillator.

The adverse interactions of permanent pacemakers and automatic implantable cardioverter defibrillators (AICD) were studied in nine patients in whom both devices were implanted. Both unipolar and bipolar pacemakers were evaluated. The permanent pacemakers were also used to do noninvasive electrophysiological studies and to induce ventricular fibrillation. Undersensing of ventricular fibrillation by the permanent pacemakers caused inappropriate pacemaker stimuli, which caused undersensing of ventricular fibrillation by the AICD in three of four patients with unipolar pacemakers. After an AICD discharge, pacemaker noncapture was seen in eight of 22 episodes for an average 4.9 seconds and inability to sense was seen in 11 of 20 episodes for an average 9.0 seconds. Counting of pacemaker stimuli and QRS by the AICD caused inappropriate discharges. Noninvasive electrophysiological testing by the pacemakers correlated with invasive testing. Furthermore, induction of ventricular fibrillation was successful in four of five patients attempted, though requiring long bursts at high outputs at the shortest cycle lengths obtainable by these pacemakers. Operation of the AICD and permanent pacemakers must be clearly understood to avoid adverse interactions of these devices.

Electric Countershock↗
PubMed1987

Antegrade and retrograde infusion of cardioplegia: assessment by thermovision.

The efficacy of two routes of cardioplegia infusion was examined by assessing the hypothermia induced in patients with critically obstructed or occluded major coronary arteries. The antegrade (through the aorta) and the retrograde (through the coronary sinus) methods of cardioplegia infusion were compared using myocardial thermograms. Patients (N = 8) were matched according to angiographic similarities of their coronary artery disease. Adequate myocardial cooling distal to a critical obstruction could frequently not be obtained with antegrade infusion of cardioplegic solution. With retrograde infusion, the desired uniform cooling of the myocardium, as determined by thermographic analysis of the surface temperatures of the heart, was obtained. We conclude that retrograde infusion of cardioplegic solution induces more effective and homogeneous hypothermia in patients with critically obstructive multivessel coronary disease, and may provide improved myocardial protection.

Angiography↗
PubMed1986

An alternative to felt pledgets in cardiac surgery.

Control of bleeding frequently requires the application of pledgeted sutures. While Teflon pledgets are useful and effective for the preparation of large pledgets, they are undesirable and frequently impossible to use when small pledgets are needed. Pledgets made of pericardium were found to be effective and can be fashioned in any needed size.

Cardiac Surgical Procedures↗
PubMed1984

Hemodynamic effects of calcium chloride injection following cardiopulmonary bypass: response to bolus injection and continuous infusion.

To determine the hemodynamic effects of intravenous injection of calcium chloride, 26 patients were studied immediately after termination of extracorporeal circulation. Eighteen patients (Group A) had injection of a single bolus of CaCl2; in the other 8 patients (Group B), the bolus injection was followed by infusion of CaCl2 at a rate of 1.5 mg/kg/min for 10 minutes. Myocardial contractile element velocity (Vpm), aortic blood flow, electrocardiograms, and left ventricular, systemic arterial, pulmonary arterial, and left atrial pressures were recorded continuously. The baseline ionized calcium level after bypass was 3.6 +/- 0.6 mg/100 ml (normal range, 3.9 to 4.5 mg/100 ml); this increased to 5.4 +/- 0.5 mg/100 ml 1 minute after CaCl2 injection. The ionized calcium level was 4.7 +/- 0.6 mg/100 ml 6 minutes after CaCl2 injection in Group A, and was 5.9 +/- 0.2 mg/100 ml and 6.4 +/- 0.2 mg/100 ml at 6 and 10 minutes, respectively, in Group B. There was significant early hemodynamic improvement after CaCl2 injection, including increases in Vpm (p less than 0.001), cardiac index (p less than 0.001), mean blood pressure (p less than 0.01), and stroke volume index (p less than 0.001). A similar pattern of hemodynamic response was observed in both groups. Approximately 1 minute after CaCl2 injection, cardiac index returned to control level, Vpm and mean blood pressure remained elevated, and heart rate declined (p less than 0.01). Systemic vascular resistance gradually increased and was significantly elevated (p less than 0.05) in Group B at 3 minutes and in Group A at 6 minutes.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1982

Pulmonary vascular morphology in shunted and nonshunted patients with tetralogy of Fallot.

The pulmonary vascular morphology of 20 patients with tetralogy of Fallot (TOF), aged 2 months to 29 years, was studied by lung biopsy. In eight patients, systemic-to-pulmonary anastomosis had been performed prior to the lung biopsy and repair. The findings were compared to control data obtained by biopsy (n = 8) or necropsy (n = 23). On comparison to control subjects, patients with TOF displayed increased wall thickness of the intra-acinar arteries, extensive extension of smooth muscle to the alveolar wall (AW) and alveolar duct (AD) arteries, and increased diameter of the AW vessels. Intimal proliferation and fibrosis was observed in two patients. Large right-to-left shunt (Q p/Qs less than or equal to 0.75) was associated with an increased number of arteries, whereas left-to-right shunt (Q p/Q s greater than or equal to 1) was associated with a decreased number of vessels. The severity of the pulmonary vascular changes were similar in the shunted (N = 8) and nonshunted (n = 12) groups and in the ipsilateral and contralateral lungs of four shunted patients having bilateral biopsy. We conclude that some pulmonary morphologic features characteristic of pulmonary vascular obstructive disease are present in all patients with TOF surviving operation. An appropriate shunt causes no additional detrimental effect on the pulmonary vasculature. Thus, although early repair may be desirable for a variety of reasons, it is not preferable over a staged repair with respect to the pulmonary vasculature.

Adolescent↗
PubMed1982

Cardiovascular effects of protamine sulfate in man.

Systemic hypotension is commonly observed in association with the administration of protamine after cardiopulmonary bypass. Previous studies have not conclusively demonstrated whether protamine induces its effect by altering myocardial performance or by changing systemic vascular resistance (SVR) or both. To elucidate the hemodynamic effects of protamine sulfate administration (150 mg/m2 body surface area), we studied 22 patients following cardiopulmonary bypass. In Group I (N = 8) protamine was infused over 30 seconds and while in Group II (N = 8), over 60 seconds. Group III (N = 6) received calcium chloride (20 mg/kg) prior to protamine administration. The hemodynamic response was assessed by continuous recording of myocardial contractile element velocity (maximal value-Vpm), aortic blood flow, systemic and pulmonary arterial and right atrial pressures, and electrocardiogram. A significant (p less than 0.05) decrease in the systolic, diastolic and mean blood pressure was observed in all groups. A significant increase in cardiac index and a significant decrease in SVR was observed in all groups. A small depression in Vpm was detected in those patients who experienced a mean blood pressure fall greater than 10 mm Hh. Heart rate and left ventricular end-diastolic pressure (LVEDP) did not change significantly. The response to protamine sulfate among the three groups was similar. These results demonstrate that protamine-induced hypotension is primarily the result of peripheral vasodilatation only partically compensated by an increase in cardiac index. In some patients, these changes were associated with a small decline in myocardial contractile state. Hemodynamic changes were transient (less that 3 to 4 minutes), unrelated to the rate of administration, and not prevented by preinjection of calcium chloride.

Blood Pressure↗
PubMed1980

Comparison of the effect of blood cardioplegia to crystalloid cardioplegia on myocardial contractility in man.

The myocardial protection achieved by blood cardioplegia was compared to that achieved by crystalloid cardioplegia in a randomized prospective series of patients having coronary bypass operations. Group BCP (n = 15) was protected with 10 degrees C blood containing potassium, 30 mEq/L; Group KCP (n = 9) by an electrolyte solution at 4 degrees C with mannitol, 25 gm/L, and potassium, 26 mEq/L, and group MgKCP (n = 9) by an electrolyte solution at 4 degrees C containing magnesium, 30 Meq/L, and potassium, 19.6 mEq/L. The three groups were comparable in regard to age, sex, preoperative left ventricular function, symptoms, propranolol use, previous myocardial infarction, number of vessels bypassed, and duration of ischemic arrest. In each patient cardiac output, left ventricular end-diastolic pressure (LVEDP), and maximum contractile element velocity (Vpm) were recorded before and after the ischemic period. All operations were performed in an identical manner with one continuous period of aortic cross-clamping averaging 52.9 minutes. No significant alterations in myocardial function were observed after ischemia within the BCP or KCP groups. However, patients receiving MgKCP had significant (p = 0.02) depression in Vpm from 2.86 +/- 7.8 to 2.04 +/- 3.6 second-1 and increase (p < 0.05) in LVEDP from 9.4 +/- 2.2 to 13.4 +/- 5.2 mm Hg. Analysis of variance between groups showed that Vpm decreased significantly (p < 0.05) and LVEDP increased significantly (p < 0.05) in the MgKCP group by comparison to the BCP group. Patients receiving BCP experienced spontaneous defibrillation more frequently (p < 0.02) and received nitroprusside postoperatively more often (p < 0.05) than patients in the other two groups. From these results we conclude that blood cardioplegia provides excellent protection during myocardial ischemia, probably better than one of the two crystalloid solutions tested but no better than the other crystalloid solution. Because the three solutions differed from one another in several respects, no conclusion can be reached about the efficacy of any one ingredient.

Adult↗
PubMed1979

Effects of isocaloric supplements of glucose or soyabean oil on lipids in tissues and plasma lipoproteins of starved and overfed chicks.

Chicks were overfed a basic diet supplemented isocalorically by soyabean oil or glucose 1, 2 and 10 days after 1 day of starvation. Carcass lipids resumed the prestarvation level 1 and 2 days after overfeeding with oil or glucose, respectively. After 10 days, an equal amount of lipid, mainly triglycerides, accumulated in the carcasses of both supplement groups. In the liver a transient accumulation of lipid was noticed in the oil-supplemented groups while a continuous increase was found in the glucose-supplemented ones. Hyperlipemia, due essentially to very low density lipoprotein (VLDL), was concomitant to liver lipid concentration. After 1 day, oil overfeeding raised plasma VLDL 6-fold, while the same level of VLDL was obtained within 2 days with glucose supplement. After 10 days, hyperlipemia was reduced in the oil-supplemented group, while it increased in the glucose-supplemented one. The fatty acid fluctuation caused by the treatments in liver lipids and plasma VLDL were grossly similar: the level of linoleic acid was reduced by glucose and increased by oil supplementation; the linoleic acid increase in VLDL preceeded that of liver lipids in the oil-supplemented groups. The results indicate a delayed transport of newly synthesized hepatic lipids in glucose-supplemented animals.

Animal Nutritional Physiological Phenomena↗
PubMed1978

Influence of overfeeding on growth, obesity and intestinal tract in young chicks of light and heavy breeds.

1. Heavy-breed (HB) chicks differed from light-breed (LB) ones in their propensity to be overfed. Whereas in the LB chicks the amount by which they could be overfed reached 70% more than the food consumed daily by the ad lib.-fed chicks, in the HB chicks the maximal excess was only 13%. 2. Overfeeding caused a slight but statistically significant increase in the linear growth rate (shank length) of the LB chicks, with an opposite effect in the HB chicks. 3. Overfeeding increased the weight of the crop, proventriculus, small intestine, pancreas, liver and adipose tissue but had no such effect on the heart, cerebrum or cerebellum. 4. Overfeeding had no effect on the specific activities of the pancreatic digestive enzymes, liver xanthine dehydrogenase, or tryptophan oxygenase (EC 1.13.1.12). The increase in the total activities was due entirely to organ hypertrophy. 5. Obesity induced in young chicks had no residual effects on the adult LB chicks, but reduced the linear growth of the adult HB chicks. 6. An explanation for the difference between breeds in response to overfeeding at an early age is discussed.

Adipose Tissue↗