Transfusion-induced immunomodulation and its possible role in cancer recurrence and perioperative bacterial infection

Over the last decade, it has become evident that homologous transfusions carry immunologic consequences beyond the well-understood ones of alloimmunization to blood cell antigens. Transfusions constitute temporary transplants of large amounts of allogeneic antigen given intravenously and cause down-regulation of many cellular immune functions. These changes may explain in part the association of transfusion with such clinically important events as (1) improved survival of renal allografts, (2) decreased recurrence rates for autoimmune disease, (3) increased frequency and earlier recurrences of solid tumors, (4) increased frequency of post-operative bacterial infection, and (5) increased severity of viral infection. Preliminary data suggest that, in animal models and clinical settings, syngeneic or autologous transfusions are not associated with such events. This finding supports the hypothesis that these associations are cause and effect and involve immunologic mechanisms.     

Chemical dependency and drug testing in the workplace.

Urine testing for drug use in the workplace is now widespread, with the prevalence of positive drug tests in the work force being 0% to 15%. The prevalence of marijuana use is highest, and this can be reliably tested. Though it is prudent to rid the workplace of drug use, there is little scientific study on the relationship of drug use and workplace outcomes, such as productivity and safety. Probable-cause testing and preemployment testing are the most common applications. Random testing has been less accepted owing to its higher costs, unresolved legal issues, and predictably poor test reliability. Legal issues have focused on the right to policy, discrimination, and the lack of due process. The legal cornerstone of a good program is a policy that is planned and agreed on by both labor and management, which serves both as a contract and as a procedure in which expectations and consequences are known. The National Institute on Drug Abuse is certifying laboratories doing employee drug testing. Testing methods when done correctly are less prone to error than in the past, but screening tests can be defeated by adulterants. Although the incidence of false-positive results is low, such tests are less reliable when the prevalence of drug abuse is also low.     

Characterisation of Pseudomonas rhamnolipids

The Gram negative organism, Pseudomonas aeruginosa, is often found in the lungs of patients with cystic fibrosis and other forms of severe bronchiectasis, where it secretes a number of extracellular toxins including the mono- and dirhamnolipids. The principal monorhamnolipid from P. aeruginosa has previously been identified as rhamnosyl-3-hydroxydecanoyl-3-hydroxydecanoate (Rh-C10.C10). A number of related mono- and dirhamnolipids have been purified from cultures of a clinical isolate of P. aeruginosa and identified by fast atom bombardment and electron impact mass spectrometry: these contain the 3-hydroxyoctanoyl-3-hydroxydecanoate (C8.C10) and 3-hydroxydecanoyl-3-hydroxydodecanoate (C10.C12) homologues. Structural isomers were also present where the order of the lipid linkage was transposed (Rh-C10.C8 and Rh-C12.C10). Unsaturated mono- and dirhamnolipids containing the 3-hydroxydecanoyl-3-hydroxydodec-5-enoate (C10.C12:1) lipid were also present.     

Dynamic changes of microtubule and actin structures in CV-1 cells during electrofusion

To study the involvement of the cytoskeletal system in the fusion of animal cells, we examined the dynamic changes of cytoskeletal proteins during the various stages of cell fusion. CV-1 cells were fused by applying a radio-frequency electrical pulse. Structural changes of microtubules (MTs) and F-actin were monitored simultaneously by double-label fluorescence microscopy. It was observed that in a few minutes after the initiation of cell fusion, MT bundles began to extend into the cytoplasmic bridges which were formed by fusing the membranes of neighboring cells. Later, a network of parallel MT bundles appeared between the adjacent nuclei of the fusing cells; such MT bundles may provide the mechanical links that are responsible for nuclear aggregation. The structural changes of F-actin during cell fusion were more complicated. We observed many different patterns of actin distribution in the fusing cells, including some giant, ring-shaped structures. Reorganization of actin is unlikely to be involved in the nuclear aggregation process. Instead, actin bundles condensed at the cell edges may help to widen the cytoplasmic bridges to allow merging of cellular contents between the fusing cells.     

Effects of spaceflight on the proliferation of jejunal mucosal cells

The mitotic indices, villus heights, and crypt depths were determined in each of three jejunal regions (proximal, middle, and distal) for five animals each in the flight, vivarium, and synchronous groups. Because of the rapid turnover of intestinal mucosal cells and the delay in recovering the flight animals, it is not known whether the proliferation of jejunal mucosal cells is affected by microgravity conditions associated with spaceflight. However, since there were no consistent differences between animals in the flight group and those in the synchronous and vivarium control groups, it appears that any effects of microgravity on the turnover of jejunal mucosal cells are short-lived. Thus, this study represents an initial step in determining the effects of microgravity on the proliferation and turnover of intestinal mucosal cells.     

Zidovudine (azido dideoxythymidine) inhibits characteristic early alterations of lymphoid cell populations in retrovirus-induced murine AIDS

Using flow cytometry technology and multiparameter analyses, we report early and characteristic alterations in lymphoid cell profile in spleen and lymph nodes due to LP-BM5 retrovirus disease (murine AIDS (MAIDS)) and the effect of azido dideoxythymidine, a nucleoside inhibitor, on these changes. MAIDS has been characterized by rapid and profound lymphoproliferation accompanied by hypergammaglobulinemia and immunosuppression. As early as 2 wk postinfection, there is a selective depletion of CD8+ cells whereas the total number of CD4+ cells increases throughout the first 8 wk of infection although the frequency is relatively stable. These population changes were partially delayed by oral AZT therapy for 6 wk postinfection. Ly-6C (AL-21) is expressed on roughly 50% of CD4+ and CD8+ cells in C57BL/6 mice. In MAIDS, the residual population of CD8+ cells is primarily Ly-6C+. The CD4+ cells have a transient increase in ratio of Ly-6C+/Ly-6C- cells at 2 wk postinfection but by 6 wk are primarily Ly-6C-. There was an increase in both the total number and percentage of Mac 1+ cells and a selective depletion of certain splenic B cell subpopulations. Azido dideoxythymidine delays these early population changes.     

Effects of prepubertal castration on the spinal motor nucleus of the ischiocavernosus muscle of the rat

Summary The location, number and size of the motoneurons innervating the ischiocavernosus muscle, identified by means of horseradish-peroxidase (HRP) retrograde transport, were studied (1) in adult untreated male rats, (2) in adult male rats castrated before puberty, and (3) in adult male rats castrated before puberty and injected with testosterone from the day of castration. After injection of HRP into the ischiocavernosus muscle, labeled motoneurons were found in the dorsolateral and dorsomedial columns of the lamina IX, at the level of L6 and S1 segments of the spinal cord. Morphometric analysis demonstrated that prepubertal castration induces a statistically significant reduction in the somatic and nuclear areas (40% and 35%, respectively, if compared to those of the control rats) of both the dorsolateral and dorsomedial motoneurons, but does not affect their number. The effects of castration are prevented by exogenous testosterone.Preliminary results were presented at the International Conference on Hormones, Brain and Behaviour, Liège, Belgium, August, 1989