Biomedical subjects

B J Zadeh

Publications and source records attributed to B J Zadeh.

4 recordsLinked to original sources

PubMed1990

Treatment with desmopressin acetate in routine coronary artery bypass surgery to improve postoperative hemostasis.

Desmopressin acetate (DDAVP) has been shown to decrease blood loss and transfusions in complex cardiac operations with long extracorporeal times. Its use in routine cardiac valve operations has been shown not to be beneficial, but its role in routine coronary artery bypass grafting operations has not been defined. We examined the effect of DDAVP in a prospective study of 60 patients undergoing uncomplicated primary coronary artery bypass grafting operations. Thirty consecutive patients received DDAVP (0.3 micrograms/kg) after cardiopulmonary bypass and were compared with 30 consecutive patients who did not receive DDAVP. No significant differences were seen in 12-hour mediastinal blood loss (465 +/- 207 ml with DDAVP versus 511 +/- 221 ml without DDAVP) or 12-24-hour mediastinal blood loss (236 +/- 127 ml with DDAVP versus 260 +/- 112 ml without DDAVP). Transfusion of blood products were similar for both groups. Platelet aggregometry at intraoperative and postoperative time points using ADP, collagen, and ristocetin was not significantly different from baseline values in either group. In a subgroup of patients with poor initial ristocetin-induced platelet aggregometry, a significant increase (p less than 0.05) in ristocetin-induced platelet aggregometry was seen postoperatively only in those patients who had received DDAVP. A decrease in blood loss and transfusions, however, was not demonstrable. In those patients who had been on aspirin or nonsteroidal anti-inflammatory drugs preoperatively, DDAVP did not improve mediastinal blood loss or transfusion needs.(ABSTRACT TRUNCATED AT 250 WORDS)

Anti-Inflammatory Agents, Non-Steroidal↗

PubMed1987

Effect of hypothermia on cellular membrane function during low-flow extracorporeal circulation.

The use of systemic hypothermia is known to allow recovery from potentially lethal states of profound hypoperfusion or total circulatory arrest. While the cellular alterations accompanying states of decreased perfusion in skeletal muscle are well defined, little is known regarding the impact of coexistent hypothermia. To investigate this issue, nine dogs were placed on total cardiopulmonary bypass (CPB) and perfused in nonpulsatile fashion. The following flow and temperature parameters were used in three different perfusion models: 3.5 L/min/m2 at 23 degrees C (group A, n = 3), 1.6 L/min/m2 at 37 degrees C (group B, n = 3), and 1.6 L/min/m2 at 23 degrees C (group C, n = 3). Assessment of cellular function in a hind limb adductor muscle by measurement of resting transmembrane potential difference (Em) and determination of tissue electrolyte distribution in a biopsy specimen was performed in the control state and again after 60 minutes of total CPB. Low-flow/hypothermic CPB (group C) was associated with depolarization of resting Em to -63.3 +/- 3.2 mV from a control value of -87.0 +/- 1.3 mV (p less than 0.05), an increase in the calculated intracellular Na ([Na]i) to 16.4 +/- 4.0 mEq/L from a control value of 7.6 +/- 1.4 mEq/L (p less than 0.05), and an increase in the ratio of the selective membrane permeabilities of Na+ to K+ (pNa/pK), to 0.067 +/- 0.013 from a control value of 0.013 +/- 0.002 (p less than 0.05). In contrast, resting Em was maintained at -86.4 +/- 6.1 mv during normal-flow/hypothermic CPB (group A), while low-flow/normothermic CPB (group B) produced an intermediate depolarization to -75.2 +/- 3.0 mV (p less than 0.05). Neither [Na]i or pNa/pK was altered significantly in group A or group B dogs. These data characterize a physiologic alteration in the cellular membrane function of skeletal muscle during low-flow/hypothermic CPB, which is similar in many respects to that accompanying hemorrhagic shock. This suggests that during periods of profound hypothermia certain flow-related derangements in skeletal muscle are not obviated and may be exacerbated.

Animals↗

PubMed1986

Myosin heavy chain expression in embryonic cardiac cell cultures.

Chick embryonic heart cell isolates and monolayer cultures were prepared from atria and ventricles at selected stages of cardiac development. The cardiac myocytes were assayed for myosin heavy chain (MHC) content using monoclonal antibodies (McAbs) specific in the heart for atrial (B-1), ventricular (ALD-19), or conductive system (ALD-58) isoforms. Using immunofluorescence microscopy or radioimmunoassay, MHC accumulation was measured before plating and at 48 hr or 7 days in culture. Reproducible changes in MHC antigenicity were observed by 7 days in both atrial and ventricular cultures. The changes were stage dependent and tissue specific but generally resulted in a decreased reactivity with the tissue specific MHC McAbs. In addition, the isoform recognized by ALD-58, characteristic of the conductive system cells in vivo, was never present in cultured myocytes. These results indicate that MHC isoforms produced in vivo may be replaced in monolayer cultures by an isoform(s) not recognized by our tissue specific MHC McAbs. This suggests that the intrinsic program of cardiac myogenesis, within cardiac myocytes, may not be sufficient to establish and maintain differential expression of tissue specific MHC in monolayer cell culture.

Animals↗

PubMed1985

Small bowel obstruction in the elderly.

Hospital records were reviewed for all patients 70 years or older who were treated for small bowel obstruction (SBO) at The New York Hospital-Cornell Medical Center from January 1975 through December 1980. There were 87 patients treated surgically and 20 patients treated nonoperatively. When the clinical evidence of strangulation was evaluated for preoperative reliability, 35 per cent of the patients had none of the accepted criteria for strangulation. Complications occurred in 60.9 per cent of patients following operative intervention. Wound infection was the most common postoperative complication and was related to wound management and to the number of enterotomies made at the time of surgery. Using delayed 1 degree closure, the infection rate was 6.2 per cent compared to 21.1 per cent when wounds were closed at surgery. The overall operative mortality was 18 per cent; advanced carcinoma accounted for 60 per cent of these fatalities. The mortality for patients with nonmalignant obstruction was 10.0 per cent as compared with 40.7 per cent in patients with cancer. From these data the authors conclude: that age alone should not be a deterrent to operative intervention in small bowel obstruction; the presence of a 1 degree or 2 degrees malignant process in the elderly patient is a significant risk factor for mortality; any patient operated on for SBO having an enterotomy should have their wound managed by delayed 1 degree closure; and because of the lack of reliability of the clinical criteria for strangulation, operative intervention in the elderly should be undertaken as soon as the diagnosis of mechanical obstruction is made.

Aged↗