Phenotype of endomyocardial biopsy-derived T-lymphocyte cultures and chronic rejection after heart transplantation

Chronic rejection (CR) is a major problem in long-term survival in heart transplantation. We analysed whether the occurrence of CR correlates with the incidence of acute rejections (AR) or with characteristics of endomyocardial biopsy-derived cell cultures. CR was diagnosed by annual angiography and defined as all coronary vascular changes. One year after transplantation 24 of the 63 patients had CR (38%). The incidence of AR in CR + and CR — patients was comparable. The patients in both groups had similar individual median percentages of EMB-yielding cell cultures. During the first year the CR — patients had more cultures in which at least 60% of the cells were CD4 + T cells (50% vs 37%, P = 0.05), due to a stronger CD4 predominance in the first 6 months. In the second year the CD4 predominance in the patients diagnosed as CR + after 1 year tended to be higher (P = 0.08). The patients had comparable percentages of cultures predominated by CD8 + T cells, γδ T cells or NK cells, irrespective of the time interval. These results might indicate that CD4 + T lymphocytes play a dual role in the aetiology of CR.     

In vitro and in vivo effects of BT563, an anti-interleukin-2 receptor monoclonal antibody

Abstract BT563, a murine anti-IL-2R MoAb, was found to be more potent than anti-Tac in inhibiting proliferation in the mixed lymphocyte reaction. Results obtained with 33 B3.1 in these experiments were similar to those with BT563. The anti-IL-2R MoAb 2A3 was shown to be a suitable agent for monitoring the effect of BT563 on peripheral blood. IL-2R-positive cells were not detected in peripheral blood samples from 1 h after the first dose until 8 days after the last dose. Plasma trough levels were measured in patients receiving 5 or 10 mg daily. The administration of BT563 to allograft recipients did not lead to clinically significant side effects.     

Arteriosclerotic changes in the myocardium, lung, and kidney in dogs with chronic congestive heart failure and myxomatous mitral valve disease.

BACKGROUND: The occurrence of small vessel arteriosclerosis in the myocardium, kidney, and lung in dogs with naturally occurring myxomatous mitral valve disease has not been previously investigated systematically. METHODS: Twenty-one dogs with naturally occurring congestive heart failure and 21 age-matched, sex-matched, and weight-matched control dogs underwent extensive pathological and histopathological examination. Morphometry and scoring of tissue sections were used to measure arterial narrowing and fibrosis in the myocardium, kidney, and lung; and intimal thickness and plaque formation in the aorta and pulmonary artery. RESULTS: Dogs with congestive heart failure had significantly more arterial narrowing in the left ventricle (P < .003), lung (P < .0001), and kidney (P < .02); intimal-medial thickening in the pulmonary artery (P = .04); and fibrosis in the left ventricle (P < .0001) than control dogs. However, they did not have more plaque formation or intimal-medial thickening in the aorta than controls. There was significantly more arterial narrowing in papillary muscles than in all other locations in dogs with congestive heart failure (P < .002). In control dogs, arterial changes were less pronounced and did not differ in different locations. CONCLUSIONS: Dogs with naturally occurring myxomatous mitral valve disease have significantly more arterial changes in the myocardium, lung, and kidney, and significantly more fibrosis in the myocardium than control dogs. This could have important implications in the management of myxomatous mitral valve disease and raises interesting questions about the occurrence and importance of intramural small vessel disease in humans with primary mitral valve prolapse.     

The influence of cytochrome P-450 induction on the disposition of carcinogenic benzo[a]pyrene 7, 8-dihydrodiol 9, 10-epoxide in isolated cells

The disposition of the carcinogenic (+)-7ß, 8-dihydroxy-9,10-epoxy-7, 8, 9, 10-tetrahydrobenzo[a]pyrene [(+)-anti-BPDE]has been studied in isolated hepatocytes obtained from 3-methylcholanthrene-pretreatedrats. In these cells different routes are acting in concertand contribute to diol-epoxide elimination. Conjugation of (+)-anti-BPDEwith glutathione (GSH) and cytochrome P-450c-mediated metabolismof the diol-epoxide to 1- and 3-hydroxy-anti-BPDE (triol-epoxides)appears to be equally important. The reactive triol-epoxidesundergo a number of secondary reactions, including covalentbinding to cellular constituents, e.g. protein and GSH, andhydrolysis to pentahydroxyderivatives. The effective intracellularlifetime of (+)-anti-BPDE is 1 min and comparable to that previouslyobserved in hepatocytes obtained from uninduced animals.     

Effects of glutathione transferase activity on benzo[a]pyrene 7,8-dihydrodiol metabolism and mutagenesis studied in a mammalian cell co-cultivation assay

This study deals with the role of glutathione transferase (GST)-mediatedconjugation of (+)-7ß,8-dihydroxy-9,10-oxy-7,8,9,10-tetrahydrobenzo[a]pyrene(BPDE) in two mammalian cell lines, human mammary carcinomacells (MCF-7) and rat hepatoma cells (H4IIE), in relation tothen-capacity to metabolize (–)-trans-7,8-dihydroxy-7,8-dihydro-benzo[a]pyrene[(–)-BP-7,8-diol] to products that induce mutations inco-cultivated V79 cells. Both MCF-7 and H4IIE cells metabolized(–)-BP-7,8-diol to BPDE, but mutations in co-cultivatedV79 cells were only detected with MCF-7 cells. However, depletionof glutathione (GSH) in H4HE cells increased the mutagenidtyof (– )-BP-7,8-diol to a similar level to that found withMCF-7 cells. Measurements of GST activity using GSH and post-microsomalsupernatants from H4IIE, V79 and MCF-7 cells indicated a substantialdifference in conjugation capacity. Although preparations fromall three cell-lines showed GST activity with l-chloro-2,4-dlnitro-benzeneas the substrate, GST activity towards BPDE could only be detectedin supernatants from H4HE cells. This is consistent with thepresence of GST 7-7 an isoenzyme highly efficient hi catalysingBPDE-GSH conjugation. The difference in GSH-conjugation activitytowards BPDE was confirmed using intact H4IIE and MCF-7 cellsin culture. These results indicate that GSH-conjugation playsa pivotal role in mutagenesis induced by polycyclk aromatichydrocarbons (PAH). Accordingly, a deficiency in GSH-conjugationcapacity may be regarded as one important factor in defininga target cell population with an increased risk for tumour initiationfollowing exposure to PAH.     

Treatment with an anti-CD18 monoclonal antibody in rabbits inhibits pneumococcal-induced leukocyte recruitment in the skin,but not in the meninges

Inflammatory recruitment of leukocytes into the cerebrospinal fluid (CSF) during bacterial meningitis has been shown to contribute to the neurological damage commonly associated with this disease. In this study we tested whether inhibition of firm leukocyte adhesion to vascular endothelium could reduce leukocyte recruitment into the subarachnoid space (SAS) and into the skin in rabbits challenged with pneumococcal cell wall (PCW) antigen. PCW was given either as an intracisternal or an intradermal (i.d.) injection. Intravenous (i.v.) treatment with a monoclonal antibody (mAb), IB4, against the leukocytic adhesion molecule CD18 has previously been documented to attenuate leukocyte CSF accumulation in experimental bacterial meningitis. In the present study, i.v. treatment with anti-CD18 mAbs (IB4) only tended to inhibit CSF leukocyte influx in animals with PCW-induced meningitis. However, if the antigen was injected i.d., treatment i.v. with the same mAb (IB4) dramatically reduced leukocyte accumulation in the skin. Our findings indicate that the mechanisms responsible for PCW-induced inflammatory accumulation of leukocytes in skin and meninges are different.     

Epitope of the vaccine-type Bordetella pertussis strain 186 lipooligosaccharide and antiendotoxin activity of antibodies directed against the terminal pentasaccharide-tetanus toxoid conjugate

Lipooligosaccharides (LOS) isolated from Bordetella pertussis strains 186 and 606 were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and high-resolution magic angle spinning nuclear magnetic resonance (NMR). These analyses distinguished between the LOS of strains 186 and 606, suggesting that the structure of LOS in B. pertussis is heterogeneous. The pentasaccharide was selectively cleaved from LOS of B. pertussis strain 186, purified, and covalently linked to a monomer fraction of tetanus toxoid. Injection of rabbits with the neoglycoconjugate emulsified in complete Freund's adjuvant yielded immunoglobulin G antibodies that were reactive with the LOS. These antibodies reacted strongly with B. pertussis LOS possessing the complete dodecasaccharide, as determined by an enzyme-linked immunosorbent assay, immunoblotting, and flow cytometry with intact, live bacterial cells. The binding epitope within the pentasaccharide was investigated by saturation transfer difference (STD) NMR spectroscopy. Protons H-1 and H-4 of the terminal alpha-D-GlcpNAc and proton H-6 and protons of an N-methyl group at H-4 of 3-substituted beta-L-FucpNAc4NMe exhibited the largest saturation transfers. STD NMR experiments confirmed that the immunodominant epitope recognized by the antineoglycoconjugate antibodies is located predominantly in the distal trisaccharide of B. pertussis 186 LOS. The antipentasaccharide antibodies induced by the conjugate inhibited the secretion of tumor necrosis factor alpha, interleukin-6, and NO by LOS-stimulated J774A.1 cells.