PubMed Health⌕ Search

Biomedical subjects

W Ko

Publications and source records attributed to W Ko.

At least 55 records · Page 3Linked to original sources

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↗

Identification of antigenic differences between the diabetogenic and non-diabetogenic variants of encephalomyocarditis virus using monoclonal antibodies.

The M variant of encephalomyocarditis (EMC) virus consists of two biologically distinct variants: one, diabetogenic D variant (EMC-D) and the other, non-diabetogenic B variant (EMC-B). These two variants cannot be distinguished by hyperimmune sera. Monoclonal antibodies were generated against EMC-D or EMC-B to identify antigenic differences between these two variants. Fourteen independent hybrid cell lines, selected from seven separate fusions of mouse myeloma cells to spleen cells isolated from mice immunized with EMC-D, consisted of 12 hybrids which produced monoclonal antibodies that neutralized both EMC-D and EMC-B, and two hybrids (ED-HJ-23 and ED-HJ-31) which produced monoclonal antibodies that neutralized EMC-D but not EMC-B. Similarly, 16 independent hybrid cell lines, selected from eight separate fusions using spleen cells prepared from mice immunized with EMC-B, consisted of 15 hybrids which produced monoclonal antibodies neutralizing both EMC-D and EMC-B, and one hybrid (EB-48A-F1) which produced antibody that neutralized EMC-B, but not EMC-D. The specificities of these monoclonal antibodies (ED-HJ-23, ED-HJ-31, EB-48A-F1) were further confirmed using an immunofluorescent technique. The D variant-specific monoclonal antibodies reacted with cells infected with EMC-D but not EMC-B. In contrast, the B variant-specific monoclonal antibody reacted with the cells infected with EMC-B but not EMC-D. It is concluded that the EMC-D- and EMC-B-specific monoclonal antibodies are able to identify antigenic differences between diabetogenic and non-diabetogenic variants of EMC virus which cannot be distinguished by hyperimmune sera.

Animals↗

Resistance of the foramen of Monro.

A greyhound dog model was used to study the importance of the foramen of Monro as a resistance element to the flow of cerebrospinal fluid (CSF). Normal dogs had no pressure differential discernible despite the infusion of artificial CSF into one lateral ventricle. When CSF was withdrawn from one lateral ventricle, however, 7 of 10 dogs showed intraventricular pressure differentials at a steady state of 3.28-5.37 mm Hg. All normal dogs undergoing rapid bolus withdrawal of CSF from the ventricles developed pressure differentials. When these experiments were performed on hydrocephalic dogs, no pressure differential could be recorded. The foramen of Monro acts as a valve mechanisms that usually closes in response to CSF withdrawals.

Animals↗

Relationship between intracranial and sagittal sinus pressure in normal and hydrocephalic dogs.

The relationship between intracranial and sagittal sinus pressure in normal and kaolin-induced hydrocephalic greyhounds was examined. In normal dogs there was an average 14 mm Hg pressure difference between the ventricles and the sagittal sinus. Elevations of intraventricular pressure were accompanied by small but consistent elevations in sagittal sinus pressure. In hydrocephalic dogs the average pressure differential was only 2 mm Hg. Also elevations of intraventricular pressure were accompanied by greater elevations in sagittal sinus pressures than those seen in normal dogs. The volume-buffering capacity of the sagittal sinus was decreased, and sinography revealed filling of unusual venous collaterals in hydrocephalic dogs--both suggesting an increased resistance to outflow in the sagittal sinus.

Animals↗