Visual identification of bacterially contaminated red cells

There have been increasing numbers of reports of transfusion-acquired Yersinia enterocolitica bacteremia (including several fatal cases). Fifteen units of whole blood were inoculated with various concentrations of Y. enterocolitica serotype 0:3 and processed into AS-3 preserved red cells (RBCs). Consistent growth of the organism was found at inoculum concentrations greater than or equal to 10 colony-forming units per mL. In all 13 units of RBCs that supported the growth of Y. enterocolitica, a darkening in color (due to hemolysis and a decrease in pO2) was observed in the bag. The attached sample segments, which were sealed from the main unit, remained sterile and did not darken. This color change was apparent in all the contaminated units by Day 35, which was 1.5 to 2 weeks after the bacteria were first detected in cultures of the blood. Hence, by comparison of the color of the segment tubing with that of the unit itself, units grossly contaminated with Y. enterocolitica can be identified prior to transfusion. Moreover, review of photographs on file at the Centers for Disease Control revealed this dramatic color change in 2 units of blood that caused transfusion-transmitted sepsis (Enterobacter agglomerans and an unidentified gram-negative bacillus, not Yersinia sp.), which demonstrated that the color change was not limited to Y. enterocolitica. This method of visual identification of contaminated units of blood could decrease the incidence of posttransfusion bacterial sepsis.     

Precocious expression of T cell functional response genes in vivo in primitive thymocytes before T lineage commitment

The genes encoding effector molecules of mature T cells, IL-2, perforin and IL-4, were found to be expressed in vivo in the most primitive subsets of thymocytes of adult mice. These subsets have previously been identified by their cell surface markers and by their expression of other T lineage-associated genes. While IL-2, perforin and IL-4 are expressed in distinct patterns, all three are expressed before the induction of RAG-1 and pre-TCR alpha mRNA expression, and are confined to subsets of cells that apparently have not yet undergone commitment to the T lineage. Thus, expression of T cell response genes appears to be one of the earliest markers of lymphocyte differentiation. Activation events marked by CD69 induction occur in these early cell types, but the response gene expression by these cells is separable from CD69 expression. IL-2 and perforin are induced again much later in thymocyte development, during TCR-dependent repertoire selection. At those stages, IL-2 protein and RNA levels per cell are higher, but the fraction of cells expressing IL-2 appears to be much lower than in the most immature stages. In addition, a striking feature of the immature populations is the robust IL-2 expression by presumptive immature NK cells. These findings are discussed in terms of the developmental origins of lineage specificity in T cell response gene regulation.      

Etiology of AIDS-related Kaposi's sarcoma and lymphoma

Kaposi's sarcoma (KS) and non-Hodgkin's lymphomas (NHL) are common consequences of HIV infection. These tumours appear to be precipitated by herpesviruses. Epstein-Barr virus (EBV) is implicated as a cause of up to 50% of systemic NHLs and up to 100% of central nervous system lymphomas in patients with AIDS. KS may be a consequence of the newly identified gamma-herpesvirus KSHV (KS-associated herpesvirus or HHV-8). This herpesvirus is found in all KS biopsies from different epidemiologic forms of this disease. KSHV is also implicated in the pathogenesis of a rare form of B cell lymphoma called body-cavity based lymphoma or primary effusion lymphoma (PEL).     

Normal and stenotic renal arteries: experimental balloon-expandable intraluminal stenting

Elastic recoil of the vessel wall is a common cause of failure of percutaneous transluminal angioplasty in renal arteries. To oppose such recoil, balloon-expandable metal stents were implanted in artificially stenotic renal arteries in pigs and normal renal arteries in dogs and pigs. The stents were then examined angiographically and histologically at regular intervals. All stents were completely covered with endothelialized neointima in 3 weeks. There was no difference in intimal thickness between the stenotic and nonstenotic renal arteries. A large stent diameter and a large open or nonmetal surface may cause less intimal hyperplasia, but nonturbulent, fast arterial flow is probably the most important factor in ensuring long-term patency of the vessel.     

Rechtsverhältnisse am menschlichen Körper unter besonderer Berücksichtigung einer Kommerzialisierung der Organ- und Gewebetransplantation

Zusammenfassung Der Beitrag befasst sich mit Rechtsverhältnissen am menschlichen Körper unter Berücksichtigung einer möglichen Kommerzialisierung. Medizin und Wissenschaft sind auf Organe und Gewebe zur adäquaten Versorgung der Bevölkerung, aber auch zur Zukunftssicherung des Forschungsstandortes Deutschland angewiesen. Rückläufige Spenderzahlen haben zu einer Organ- und Gewebeknappheit in Deutschland geführt und die Diskussion um eine Kommerzialisierung von Organ- und Gewebetransplantationen wieder entbrennen lassen. Den geäußerten Kommerzialisierungstendenzen stehen strafsanktionierte Regelungen im Transplantationsgesetz (TPG) und Resolutionen der WHO bzw. die Bioethik-Konvention des Europarates entgegen, die Handel mit menschlichen Organen und Geweben ablehnen bzw. verbieten. Nach der Rechtsprechung des Bundesverfassungsgerichts kam dem Gesetzgeber im Anwendungsbereich des TPG unter Berücksichtigung der medizinischen Möglichkeiten, der ethischen Anforderungen und der gesellschaftlichen Vorstellungen ein weiter Beurteilungs- und Gestaltungsspielraum zu. Trotz der Regelungen im TPG verschärft sich der Organ- und Gewebemangel in Deutschland. Deshalb erfährt die gesetzgeberische Gestaltung vermehrt Kritik, die sich u. a. auf die strafrechtliche Ausgestaltung des TPG und die ausgebliebene Förderung der Spendebereitschaft durch die erweiterte Zustimmungslösung bezieht.