Role of leukocyte depletion in noncholinergic bronchoconstriction of guinea pigs.

To test the role of leukocytes in the activation of afferent C-fibers in the lung, 33 guinea pigs, 18 control and 15 experimental or leukocyte depleted, were used. The leukocyte depletion was accomplished with an intraperitoneal injection of cyclophosphamide (100 mg/kg) 96 h prior to the study. On the day of the study, bronchial constriction was produced either by exsanguination (n = 17) or by capsaicin injection (16 micrograms/kg, i.v.) (n = 16) in anesthetized-paralyzed animals. Venous blood samples were collected for leukocyte counts. At 1-30 min following the above treatment, the maximal expiratory flow maneuver was performed and a decrease in the maximal expiratory flow at 50% baseline total lung capacity (Vmax50) was used as an index of bronchoconstriction. The leukocyte count decreased significantly following the pretreatment with cyclophosphamide [an average of 6217 +/- 612 (control) vs. 2242 +/- 334/mm3 (experimental)]. Exsanguination caused a gradual decrease in Vmax50 with time, indicating a temporal increase in bronchoconstriction. Capsaicin injection, on the other hand, caused an immediate (1 min) marked bronchoconstriction, which attenuated gradually with time. At a specific time point, leukocyte depletion did not produce any significant change in Vmax50 compared to the control group for both types of bronchoconstrictions. Based on these results, we conclude that leukocytes may play an insignificant role in the bronchoconstriction caused by the activation of afferent C-fibers in guinea pig lungs under our experimental conditions.     

Isolation,sequence, and conformation of seven trichorzianines from Trichoderma harzianum

From the antagonistic fungus Triclroderma harzianum, a group of acidic new peptides, trichorzianines B (TB), was isolated in addition to neutral trichorzianines A (TA) previously studied. TA and TB exhibit various biological activities related to their membrane properties and a different behaviour of the two groups was noticed. As observed for other peptaibols, TB consist in a microheterogeneous mixture which was resolved into pure peptides by reversed-phase C18 HPLC. The sequence of the seven main isolated TB, namely TB IIa, TB IIIc, TB IVb. TB Vb. TB VIa. TB VIb, TB VII, was determined by the combined use of positive ion FAB mass spectrometry and 2D ¹H n.m.r. spectroscopy, including COSY and NOESY experiments. TB differ from the corresponding TA only by the replacement of Gln 18 in the TA sequence by a glutamic acid. The ¹H n.m.r. data suggested that the TB are mainly organized in an α helix.     

Antibodies cross-reactive with E- and P-selectin block both E- and P- selectin functions

E- and P-selectin are inflammation-induced cell adhesion molecules that mediate leukocyte-endothelial cell and leukocyte-platelet interactions. Monoclonal antibodies (MoAbs) specific for either E-selectin or P- selectin are protective in several animal models of inflammatory disease. To generate an MoAb with broader therapeutic potential, MoAbs that bind to both E- and P-selectin were generated by immunization of mice with mouse pre-B cell lines transfected with human E- and P- selectin. Interestingly, although the only selection criterion was the ability to bind both E- and P-selectin, all three antibodies obtained efficiently block both E- and P-selectin-mediated functions. The inhibited functions include neutrophil or HL-60 cell binding to tumor necrosis factor-alpha-activated human umbilical vein endothelial cells, E- or P-selectin transfectant cell lines, and platelet-HL-60 rosetting. These antibodies, EP-5C7, EP-2C9, and EP-1D8, recognize the same or overlapping epitope within the lectin domains of E- and P-selectin. The data suggest that functionally important epitopes of homologous proteins can be targeted by selecting for antibodies with reactivity toward both proteins. Furthermore, a potent blocking antibody specific for both E- and P-selectin may provide a more effective and broadly useful reagent for treating acute and potentially certain chronic inflammatory conditions.     

The specific hospital significantly affects red cell and component transfusion practice in coronary artery bypass graft surgery: a study of five hospitals

BACKGROUND: Interhospital differences in blood transfusion practice during coronary artery bypass graft (CABG) surgery have been noted, but the underlying issues have not been identified. STUDY DESIGN AND METHODS: Records of 3217 consecutive CABG cases in five university teaching hospitals in 1992 and 1993 were stratified by hospital, type of revascularization conduit, patients' sex, and other factors. Statistical methods were used to compare patient characteristics, transfusion outcomes, and hospital outcomes. RESULTS: Forward two-step logistic regression using patient likelihood of red cell transfusion factors in the first step and the specific hospital in the second step revealed a significant effect of hospital on the delta odds ratios for red cell transfusion. This finding was confirmed by analyses of a highly stratified subset of cases, males in diagnosis-related group 107 (primary cases of coronary bypass without coronary catheterization) who underwent revascularization with venous and internal mammary artery grafts, revealing variations among hospitals from 109 to 457 units of red cells transfused per hundred cases. Corresponding variations in transfusions of all blood components were from 324 to 1019 units by hospital. Variation in red cell transfusion practice among surgeons in the same hospital was not responsible for these interhospital differences. CONCLUSION: The effect of the specific hospital on transfusion practice is attributed to institutional differences that, through reasons of training or hierarchy, become ingrained in hospitals.     

Differential effects of microenvironmentally presented interleukin 3 versus soluble growth factor on primitive human hematopoietic cells.

The effect of IL-3 on hematopoiesis in long-term culture (LTC) was studied by cocultivating normal human marrow cells with human marrow fibroblast feeders engineered to constitutively produce IL-3 and by adding soluble IL-3 to LTC according to a variety of dose-time schedules. Feeders stably producing 7 ng/ml IL-3, or LTC to which 10 ng/ml IL-3 was added daily for 5 wk, but not once or twice weekly for the same time period, increased the output of mature nonadherent cells and progenitors from LTC as compared to control cultures. At the time of the weekly half-medium change, when primitive clonogenic progenitors in the adherent layer of standard LTC are quiescent, such cells were actively cycling in cultures containing a continuous source of an adequate dose of IL-3. In LTC, where the proportion of IL-3-producing cells in the feeder layer was diluted to 10% and no IL-3 was detectable in culture medium, primitive adherent layer progenitors were, nevertheless, maintained as a population of continuously proliferating cells. Thus, the presence of IL-3 in LTC can enhance the proliferation and differentiation of very early human hematopoietic cells, but the concentration, duration of exposure, and method of IL-3 presentation are important determinants of the ultimate effects observed.     

Immunogenicity, Antigenicity, and Endothelial Viability of Aortic Valves Preserved at 4°C in a Nutrient Medium

In patients undergoing aortic valve replacement, allograft valves stored at 4 degrees C in a nutrient medium have been associated with excellent immediate and long-term results. The effects of this method of prolonged storage on the antigenic, immunological and cellular characteristics of these grafts are incompletely understood. This study was designed to study these phenomena in rat aortic valves subjected to antibiotic sterilization and stored for up to 3 weeks in RPMI containing 10% fetal calf serum. Selected valves from Brown Norway rats were implanted heterotopically into the abdominal aorta of Lewis rats. Other valves were studied prior to transplantation. Antigenicity was determined by immunocytochemical staining using monoclonal mouse antibodies directed at Class I and Class II rat antigens. Immunogenicity was determined by duration of second-set skin graft survival following heterotopic aortic valve implant. Endothelial cell viability was determined by flow cytometric analysis of endothelial cells harvested from aortic valve allografts by collagenase digestion. Only fresh valves and valves stored for 1 day were positive for Class I antigens; no valves were positive for Class II antigens. Duration of skin graft survival was prolonged with greater duration of storage, but grafts remained immunogenic after 21 days of storage. Endothelial cell viability declined from 95% in the fresh valves to 64% after 21 days of storage. With prolonged duration of allograft valve storage at 4 degrees C, there is an attenuation of antigenicity, immunogenicity, and endothelial cell viability. Loss of endothelial cells may contribute to the changes in immunological responses to the valve allografts. The expression of antigens on the endothelial surface is not a reliable predictor of immunological response.     

Interleukin-7 is a growth factor for Sézary lymphoma cells.

Sézary syndrome is a cutaneous T cell lymphoma characterized by infiltration of the skin by CD4+ cells. These cells generally respond poorly to mitogens and T cell activators. We have studied the action of IL1 to IL4, IL6, and IL7 on the proliferation of Sézary cells from 12 patients. With the exception of IL2 and IL7, the cytokines studied had no proliferative effect on these cells. Whereas IL2 had only a low proliferative capacity (two- to threefold increase) on peripheral blood mononuclear cells, recombinant IL7 constantly induced a very significant (3-40-fold increase) proliferative response, and was used successfully to generate cell lines in three out of eight cases. Growth of Sézary cell lines was shown to be strictly dependent on IL7, and after 2-5 wk of culture presented a switch to a homogeneous phenotype CD3+4+8-7- (except for one line that remained CD7+), with a typical morphology of Sézary cells. Their tumoral origin was demonstrated by the expression of the same T cell receptor-beta gene rearrangement as the patients' T cells. Importantly, cultured normal epidermal keratinocyte supernatants could support the growth of our Sézary lines. Furthermore, the proliferative activity contained in these supernatants was completely blocked by a monoclonal anti-IL7 antibody. These results suggest that IL7 may, therefore, represent an important cytokine in the physiopathology of cutaneous T cell lymphoma.     

Observations on the influence of active immunization against somatostatin on the reproductive performance of sheep and pigs

Somatostatin (SRIF) is known to have inhibitory effects in a wide variety of tissues but a role in reproduction has not been described. The present studies describe the influence of SRIF immuno-neutralization on the reproductive performance of sheep and pigs. In experiment 1, Rambouillet x Suffolk ewe lambs were actively immunized against SRIF conjugated to ovalbumin (SI; n = 24) or were not immunized (CT; n = 32). Primary immunizations were initiated at weaning and boosters given at 4-week intervals, as well 10 days before breeding and lambing. Over two years, breeding periods were September and January (in-season) and May (out-of-season). Pregnancy rates were higher for SI than for CT ewes following both in-season (P less than 0.01) and out-of season breeding (P less than 0.06). The number of lambs born per ewe lambing was not affected by treatment. In experiment 2, Yorkshire x Landrace gilts were actively immunized against SRIF-ovalbumin conjugate (n = 37) or were not immunized (n = 38). Primary immunizations were given at 39.8 +/- 1.5 kg body weight and boosters after 4 weeks, 10 days before breeding and at 105 days of gestation. Some SI (n = 15) and CT gilts (n = 17) were slaughtered 10 days after estrus to determine ovulation rates. Remaining SI (n = 22) and CT (n = 21) gilts carried their litters to term. Ovulation rates tended to be higher (P less than 0.1) in SI than CT gilts (11.8 +/- 0.6 vs. 10.7 +/- 0.4). There was no effect of treatment on pregnancy rates to initial breeding (86.4 vs. 90.5% for SI and CT gilts, respectively) but first litter size tended to be larger (P less than 0.07) for SI than for CT gilts (9.95 +/- 0.34 vs. 9.00 +/- 0.38). There was no effect of treatment on litter growth performance during lactation. These data provide evidence that SRIF may be involved in the regulation of reproduction.