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Biomedical subjects

S Xia

Publications and source records attributed to S Xia.

61 records · Page 4Linked to original sources
PubMed1995

Changes of plasma dynorphin levels before and after percutaneous balloon mitral commissurotomy in patients with mitral stenosis.

Plasma dynorphin A1-13 levels were measured in 33 patients with mitral stenosis before and after percutaneous balloon mitral commissurotomy (PBMC). The results show that the basal levels of plasma dynorphin in blood from the antecubital vein in the patients were significantly higher than those in 31 healthy control subjects. The increase in circulating dynorphin closely correlated with the functional cardiac status and the presence of atrial fibrillation. Ten to fifteen minutes after PBMC, plasma dynorphin levels in blood from the femoral vein increased significantly. Seventy-two hours after the procedure, the levels of plasma dynorphin in blood from the antecubital vein had decreased significantly, but they did not decrease to the normal range. Plasma dynorphin levels in blood from the femoral vein were positively correlated with the mean left atrial pressure and the mean right atrial pressure before the first balloon inflation. Plasma dynorphin levels in blood from the antecubital vein were positively correlated with the heart rate and the mean transmitral pressure gradient, and negatively with the mitral valve area before and 72 hours after PBMC.

Adolescent↗
PubMed1994

Transplantation of spleen cells in patients with hemophilia A. A report of 20 cases.

It has been reported that coagulation factor VIII (F. VIII) is produced in the spleen and other organs. Transplantation of splenic whole organ and spleen cells may, therefore, be used to treat patients with hemophilia A. The donor spleen from brain-dead donors was used to prepare spleen cell suspension for transplantation. Twenty-two spleen cell transplantations were performed on 20 patients suffering from severe hemophilia A at our institutes. Two of them underwent a second infusion of spleen cells since there was no increase in plasma F. VIII activity after the first transplantation. All but two patients showed a marked clinical improvement. Increased plasma F. VIII activity was observed in 18 of 20 cases. The peak plasma F. VIII activity in these recipients rose to 10%-15% posttransplantation in 14 cases and to over 15% in 4 cases from pretransplant levels of 0%-3%. Generally, the elevation of plasma F. VIII activity could be detected 4-7 days following transplantation of spleen cells and this lasted from 22 to 58 weeks. Four patients whose peak plasma F. VIII activity was greater than 15% experienced an uneventful course after transplantation. The patients with plasma F. VIII activity over 10% showed less frequent bleeding and prolonged intervals between bleed as well as improvement in hemophilic arthrosis. Two patients who had interval hematuria before transplantation did not have any relapse for up to 2 years after infusion of the spleen cells. These results indicate that spleen cell transplantation may be a promising method for the management of patients with hemophilia A.

Adolescent↗
PubMedDate not supplied

Memory consolidation in Drosophila operant visual learning.

A new conditioning procedure, developed for the operant learning paradigm at the flight simulator, leads to stronger learning scores in wild-type flies. This procedure produces mean learning indices up to LI = 0.52. The heat-avoidance behavior acquired during training is very difficult to extinguish during extinction. Memory decays quickly during the first 3 hr after training and still is measurable 48 hr later. Disruption experiments demonstrate that memory can be disrupted by cold anesthesia within the first approximately 20 min after training, whereas KCl- and CXM-feeding regimens abolish memory soon after training and 3 hr later, respectively. These results initially suggest at least three distinct memory phases involved in memory consolidation in Drosophila after operant conditioning.

Animals↗