Schistosoma mansoni : cercarial shedding patterns from a mixed infection of Biomphalaria glabrata with two (early and late) chronobiological variants

 The cercarial emergence rhythms of Schistosoma mansoni were analyzed for mixed infection of the snail Biomphalaria glabrata with two chronobiological strains, one with an early shedding pattern and the other with a late shedding pattern. Under these conditions, each parasite strain kept its own circadian cercarial emergence pattern. When the chronobiological variants were of the same species, no interference between the trematode larvae occurred during the cercarial emergence process. These results confirm that within the host-parasite system the parasite component is directly responsible for the cercarial emergence pattern. Received: 16 September 1996 / Accepted: 18 October 1996     

A complementarity-determining region peptide of an anti-desmosome autoantibody may interact with the desmosomal plaque through molecular mimicry with a cytoplasmic desmoglein 1 sequence

The sera of patients with pemphigus, a group of autoimmune blistering skin diseases, contain autoantibodies directed against components of adhering junctions termed desmosomes. F12, a human monoclonal antibody derived from a pemphigus patient, recognizes an unknown polypeptide of the desmosomal and hemidesmosomal plaques. The third complementarity-determining region of the F12 heavy chain (VH-CDR3) was shown to share a four-amino-acid sequence (GSSG) with the intracellular domains of desmoglein 1 and bullous pemphigoid antigen 2 which interact with components of, respectively, the desmosomal and hemidesmosomal plaques. Computer modeling of F12 showed that the GSSG sequence protudes inside the antigen-combining site and thus might be involved in antigen interactions. The GSSG sequence is essential to F12 function, since a peptide containing the VH-CDR3 inhibited its binding to target antigens while VH-CDR3 peptides with specific modifications of the GSSG sequence did not. These data allow us to hypothesize that certain autoantibodies produced during the course of an autoimmune disease can behave as adhesion molecules, through the molecular mimicry of the motif involved in protein/protein adhesion, and to propose a new self-antigen binding mechanism for some autoantibodies.     

Ginkgo biloba Extract (EGb 761) Pretreatment Limits Free Radical Oxidative Stress in Patients Undergoing Coronary Bypass Surgery

A growing body of evidence supports the trigger role of free radicals in the delayed functional and metabolic myocardial recovery following cardiopulmonary bypass (CPB) in humans, thus opening the field to specific therapies. This clinical study was designed to evaluate, in 15 patients undergoing aortic valve replacement, whether the extent of CPB- and reperfusion-induced lipid peroxidation, ascorbate depletion, tissue necrosis, and cardiac dysfunction is reduced by orally administered EGb 761, a Ginkgo biloba extract withpotent in vitro antiradical properties. Patients received either EGb 761 (Tanakan, 320 mg/day, n = 8) or a matching placebo (n = 7) for 5 days before surgical intervention. Plasma samples were obtained from the peripheral circulation and the coronary sinus at crucial stages of the operation (i.e., before incision, during ischemia, and within the first 30 minutes post-unclamping), and up to 8 days postoperatively. Upon aortic unclamping, EGb 761 inhibited the transcardiac release of thiobarbituric acid species (p ` 0.05), as assessed by high-performance liquid chromatography, and attenuated the early (5–10 minute) decrease in dimethylsulfoxide/ascorbyl free radical levels, an electron spin resonance index of the plasma ascorbate pool (p ` 0.05). EGb 761 also significantly reduced the more delayed leakage of myoglobin (p = 0.007) and had an almost significant effect on ventricular myosin leakage (p = 0.053, 6 days postoperatively). The clinical outcome of recovery of treated patients was improved, but not significantly, compared with untreated patients. Our results demonstrate the usefulness of adjuvant EGb 761 therapy in limiting oxidative stress in cardiovascular surgery and suggest the possible role of highly bioavailable terpene constituents of the drug.     

The relationship between dietary factors and serum cholesterol values in the coloured population of the Cape Peninsula

A cross-sectional study of 976 coloured subjects aged 15-64 years identified a population consuming a typical Western diet. Nutrient intake, determined by the 24-hour dietary recall method, reflected a diet high in fat (37% of total energy intake) and animal protein and a polyunsaturated/saturated fatty acid ratio of 0.85. Only 32.2% of men and 27.5% of women consumed a prudent diet (Keys score less than or equal to 28). The influence of this Western diet on serum total cholesterol (TC) levels was seen to be marked when participants with a high risk of developing coronary heart disease (CHD) were compared with those with a TC level putting them at low risk; the former consumed significantly more saturated fat and had a higher mean Keys score. Multiple linear regression analysis on TC levels of men identified six variables that explained 26.9% of the variation of TC. These were body mass index, age, the inverse of the polyunsaturated fat intake, saturated fat intake, polyunsaturated/saturated fat ratio and cholesterol intake. For women only three variables (age, the inverse of the polyunsaturated/saturated fat ratio, and body mass index) explained 30.2% of the variation of TC. Promotion of the prudent diet to lower TC levels of the coloured population of the Cape Peninsula is an increasingly urgent priority.     

A European multicenter study of chronic graft-versus-host disease. The role of cytomegalovirus serology in recipients and donors--acute graft-versus-host disease, and splenectomy

A group of 466 leukemic bone marrow transplanted patients were reported from 17 European bone marrow transplantation teams. Of these, 285 survived more than 3 months and could be evaluated for chronic GVHD. The cumulative incidence of chronic GVHD was 32% two years after BMT. The following factors were statistically significantly associated with chronic GVHD in bivariate analysis: high donor and recipient age, splenecacute GVHD, pretransplant seropositivity to CMV among the recipients and the donors, and donor seropositivity to 3 or 4 different herpesviruses, compared with 0-2, prior to BMT. In multivariate analysis pretransplant recipient CMV seropositivity in combination with donor CMV seropositivity prior to BMT (P = 0.0006), a previous grade II-IV acute GVHD (P = 0.001), and splenectomy (P = 0.01) were significantly associated with chronic GVHD. Thus, in addition to acute GVHD, CMV immune donor cells may be triggered by latent CMV in the recipient, which may play a role in the triggering of chronic GVHD. The possible role of splenectomy in GVHD is also discussed.     

Effects of postoperative pain on lung volume in patients undergoing aortic surgery

To evaluate the potential advantages of the administration of extradural morphine to control postoperative pain and its effects on respiratory function, 39 patients were randomly assigned to one of two groups before aortic surgery. The first group (20 patients) received intravenous analgesia as required (control group). The second group (19 patients) received extradural morphine in a programmed fashion. During the immediate postoperative period the following parameters were measured in both groups: respiratory rate, vital capacity, peak expiratory volume in the first second, PaO2, PaCO2, arterial pH, heart rate, and systolic and diastolic blood pressure. In the group treated with morphine the postoperative increase in heart and respiratory rate was significantly smaller than in the control group (p less than 0.01). Postoperative forced pulmonary volumes were higher in the morphine group (p less than 0.01). However, there were no differences in time of hospitalization between both groups. There were more complications in the control group, but the difference did not reach statistical significance.     

Early detection of prosthetic-hip loosening. Comparison of low- and high-viscosity bone cement

In 1987, we reported the 1-year migration of the prosthetic components in 16 hips followed by roentgen stereophotogrammetry after fixation with either low- or high-viscosity cement. We now report the migration of these prosthetic components during another 2 postoperative years. Eight acetabular components, four in each group, migrated cranially; and four femoral components, three in the low-viscosity and one in the high-viscosity group, migrated distally. All but two migrations were obvious 4 months postoperatively, which indicates that what is called late loosening is the result of late detection rather than of late occurrence of loosening. Low-viscosity cement did not provide improved prosthetic fixation.     

Glial cell line-derived neurotrophic factor (GDNF) gene expression in the human brain: A post mortem in situ hybridization study with special reference to Parkinson's disease

Summary Glial cell line-derived neurotrophic factor (GDNF) is a potent neurotrophic factor for dopaminergic neurons. Since dopaminergic neurons degenerate in Parkinson's disease, this factor is a potential therapeutical tool that may save dopaminergic neurons during the pathological process. Moreover, a reduced GDNF expression may be involved in the pathophysiology of the disease. In this study, we tested whether altered GDNF production may participate in the mechanism of cell death in this disease. GDNF gene expression was analyzed by in situ hybridization using riboprobes corresponding to a sequence of the exon 2 human GDNF gene. Experiments were performed on tissue sections of the mesencephalon and the striatum from 8 patients with Parkinson's disease and 6 control subjects matched for age at death and for post mortem delay. No labelling was observed in either group of patients. This absence of detectable expression could not be attributed to methodological problems as a positive staining was observed using the same probes for sections of astroglioma biopsies from human adults and for sections of a newborn infant brain obtained at post-mortem. These data suggest that GDNF is probably expressed at a very low level in the adult human brain and its involvement in the pathophysiology of Parkinson's disease remains to be demonstrated. GDNF may represent a powerful new therapeutic agent for Parkinson's disease, however.     

Clinical prognostic criteria in the rehabilitation of cerebral infarct patients

79 patients with ischaemic stroke were investigated, with 31 patients showing a pure hemiparesis, 22 an additional depressive syndrome and 26 a dementia. After an average time intervall of 28 months, a follow-up investigation was performed on these 3 groups relative to their course and rehabilitation outcome. No significant differences were present between the 3 groups as regards age and sex distribution as well as hemisyndrome severity. The neurological and psychiatric findings at follow-up differed significantly from the primary findings. Also, significant differences were found in the degree of disability, and in the self- and family ratings of rehabilitation outcome, with a poorer long-term course, i.e. a higher degree of disability, significantly more frequent in the dementia group. Comparison of self- and family-ratings showed that self-ratings given were significantly worse in the dementia and depressive groups, whereas patients with purely neurological symptoms rated themselves better than their relatives did.