Ten-year experience with pericardial xenograft valves.

Five hundred fifty-three pericardial xenografts were inserted in 520 patients during a 9-year period at the Fu Wai Hospital in Beijing. The bovine pericardial xenograft was modeled after a similar type of prosthesis manufactured by Shiley Inc. (Irvine, Calif.). The late mortality rate in this series was only 1.8% per annum and the actuarial survival rate was 73.0% +/- 12% at 10 years. There was a very acceptable low incidence of thromboembolism of 0.41% per annum without the need for permanent anticoagulation. This is similar to the clinical reports with other tissue valves. The main question is the durability of the tissue prosthesis or, in other words, the freedom from valve-related clinical complications. In this series, the expected actuarial valve durability rate was 75.0% +/- 8.8% at 10 years. Whether this will continue to hold up over the next follow-up period is unclear. Certainly other tissue prostheses have shown significant degeneration rates beginning after the sixth year that have risen progressively thereafter. In any case, given the relatively low probability of thromboembolic phenomenon without anticoagulation, the trade-off of a prosthesis that may not be as durable as the mechanical ones is certainly acceptable.

[Surgical intervention of infective endocarditis].

33 patients with infective endocarditis were treated from 1980 to 1989. 31 of them were operated on for primary endocarditis complicated by congenital heart disease (5 patients) and valvular heart disease (26 patients). Two patients (6.5%) died postoperatively and 2 patients with primary endocarditis complicated by aortic insufficiency died without operation. In 10 patients with endocarditis secondary to open-heart surgery, 6 were reoperated upon but 5 of them died; in the remaining 4 who were not reoperated on died. We consider that surgical intervention for endocarditis, either primary or postoperative, should be taken as early as possible after a short period of ineffectiveness of antibiotic therapy.

Spontaneous production of human gamma interferon in vitro by splenic lymphocytes of patients with idiopathic thrombocytopenic purpura.

Lymphocytes derived from spleens of traffic trauma victims do not appear to produce human interferon (IFN) activity, spontaneously, in vitro. However, lymphocytes derived from spleens of four ITP patients were found to produce significant amounts of human IFN activity. The IFN activity produced by the splenic lymphocytes of ITP patients was neutralized by anti-gamma-IFN antisera but not anti-alpha or anti-beta antisera. The IFN activity was found to be unstable at pH 2.0 and at 56 degrees C. Thus the human IFN activity of splenic lymphocytes is characterized as human gamma-IFN. No human IFN activity was detectable in the serum of the ITP patients and it is not known whether the splenic lymphocytes of ITP patients also produce human gamma-IFN in vivo. The observations suggest that conditions prevail in the ITP state that predispose the splenic lymphocytes to produce human gamma-IFN without stimulation by exogenously added inducer.

Transfer of information from mRNA to chromosomes by reverse transcription in early development of goldfish eggs.

In earlier publications, we have recorded evidence that micro-injection of globin mRNA from rabbit into goldfish eggs leads to the production of rabbit globin in mature red blood cells of goldfish. This paper is concerned with the mechanism of that apparent transfer of genetic information from the cytoplasm to the nucleus. We investigate the possibility that the injected mRNA is reverse transcribed to create a corresponding cDNA in goldfish eggs. By using purified mRNA from rabbit reticulocytes and micro-injection into enucleated and nucleated goldfish eggs, we show that the production of a DNA sequence hybridizes to cloned cDNA of rabbit globin mRNA and appears to become incorporated into the chromosomes of the developing eggs.