The prevalence of Candida albicans-associated diarrhoea in Buea, South West Cameroon

A total of 362 stool specimens were collected from 184 and 178 patients presenting at the Buea district Hospital with and without diarrhoea, respectively. The samples were screened and cultured for Candida albicans using standard microbiological procedures. Of the 184 diarrhoeic stool cultures, 35.9% showed C. albicans overgrowth as indicated by count >or=10(4) CFL/mL. Of the 178 non diarrhoeic stool cultures, C. albicans was identified in 23.6% of samples and counts were all <10(4) CFU/mL. An association was observed for C. albicans overgrowth and diarrhoea (p<0.001). The majority of isolates (87.8%) from the 66 samples showing candida overgrowth were susceptible to Amphotericin B in anti-fungal drug sensitivity assays. Results of the study highly suggest that C. albicans is an important cause of diarrhoea in the study area. We recommend that this fungus should be routinely checked in individuals presenting with diarrhoea particularly children and patients on prolonged or frequent antibiotic therapy.     

Histocompatibility Determinants in Israeli Jewish Patients with Multiple Sclerosis

The distribution of 24 HLA antigens of the A and B loci was investigated in 197 Israeli Jewish patients with multiple sclerosis (MS) from various Jewish ethnic origins including central and eastern Europe, countries bordering the Mediterranean, the Middle East and from native-born Israelis. The results were compared with the HLA antigen frequencies in a control sample of 455 unrelated individuals representing the general Jewish population. The frequency of HLA-Bw40 among all MS patients (15%) was significantly greater (P less than 0.001) than among the controls (7%). In contrast to the findings in MS patients from other populations, there was no increased frequency of A3 and B7 and Dw2 was present in only one out of 28 patients. The study showed a similar distribution of HLA-A and -B locus antigens, especially of Bw40, in Jews of diverse ethnic origins represented in the control group.     

Ultrastructural and elemental analysis of calcification of advanced swine aortic atherosclerosis

During progression and in the early phase on a regression regimen, calcification of the necrotic portion of the atheroma of swine abdominal aorta occurred primarily in degenerated cells or in membranous, vesicular cellular degradation products which varied in size, shape, and the amount of mineral deposit. Calcium appeared to be deposited in amorphous granular or needle-like crystalline forms. Energy dispersive X-ray and line profile analysis showed that the major elements in the heavily calcified portions of the plaques were calcium and phosphorus. There was a direct relationship between the distribution and concentration of these elements indicating that the mineral deposit was a calcium phosphate. Select area electron diffraction analysis of grossly calcified portions of the plaque gave a diffraction pattern identical to that of calcium hydroxyapatite. Calcification was not observed to occur on elastic tissue or collagen fibers.     

Predictability of Individual Differences in Activation Processes in a Field Setting Based on Laboratory Measures

The predictability of individual differences in activation processes was investigated in a multi-method laboratory-field study. Male students of physical education (N=58) were examined under various emotionally activating and physically demanding conditions (mental arithmetic, reaction time, free speech, cold pressor test, bicycle ergometer). The assessment included multi-channel recordings of pre-start phases in an athletic stadium and performance on a 1000 m run. Basal heart rate was also recorded during sleep. This multi-situational assessment was repeated after three weeks, three months, and, for most (N=42) subjects, after one year. Significant relationships exist between scores from corresponding conditions of relaxation, anticipation, and performance of physical exercise. However, with the exception of heart rate, correlation coefficients are rather small and seem to be of questionable predictive validity. A generalizability study further supports the general conclusion: To increase the practical relevance in psychophysiological investigations of stress/strain phenomena, such studies should directly assess individual differences in the criterion situations themselves.     

Topography and behavior of Sertoli cells in sparse culture during the transitional remodeling phase

We report observations on the behavior of Sertoli cells in sparse culture during the period from the time of plating to the time of initial confluence (the transitional remodeling phase). Changes in shape, structure, and polarity of cells, as well as changes in migration patterns and cell-cell association patterns, have been followed during the transitional remodeling phase with the aid of topographical markers. These markers are based upon differences between ultrastructural features of the basolateral and apicolateral surfaces. The basolateral surface is characterized by plasmalemmal blebs, whereas the apicolateral surface is characterized by filopodial extensions. Structural differences observed in situ remain evident in Sertoli cells isolated by sequential enzymatic treatments that are described. Another marker is provided by laminin-binding sites, which are detected exclusively on the blebbed, basolateral surfaces of freshly prepared Sertoli cell aggregates. The orientation described is sustained during the initial radial migration of Sertoli cells explanted on uncoated glass coverslips. Under these conditions, blebs are detected only on the dorsal surfaces, and filopodial extensions are evident only on the ventral surfaces. In contrast, Sertoli cells sparsely plated on a reconstituted basement membrane (air-dried Matrigel) migrate rapidly, display an extraordinary capacity to form elaborate cytoplasmic extensions for cell-cell and cell-substratum contacts, and readily retract blebs and filopodial extensions. These cells do not form mosaic borders, whereas cells plated on uncoated glass do form a monolayer with mosaic-like borders. Cells sparsely seeded on gelated Matrigel migrate preferentially at gaps between adjacent cell explants, and develop a compact cell-cell association pattern. These cells display few, if any, cytoplasmic extensions. We compare the behavior of Sertoli cells sparsely plated on Matrigel with the behavior of Sertoli cells in situ during different stages of development.     

Immunogenetic considerations in islet transplantation: The role of Ia antigens in graft rejection

As demonstrated by Faustman et al., islets that are pretreated with Ia antibodies and complement show markedly prolonged survival as compared with islets, with the same immunogenetic disparity, without antibody pretreatment. In order to test whether it is simply the absence of an allo-Ia disparity that accounts for this finding, we have transplanted islets across class I disparities alone; in certain cases, such islets are rapidly rejected. Yet, even though there is no allo-Ia difference on such islets, pretreatment of the islets with anti-Ia monoclonal antibody also results in markedly prolonged survival. We suggest that the presence of Ia antigens may serve as a differentiation marker for cells that can present class I antigens in an immunogenic manner; further, allo-Ia antigens can lead to a stronger anti-class I rejection response.     

Disseminated neuroblastomas under 1 year of age: cell biology and prognosis

Tumor specimens of 203 infants with neuroblastomas of different clinical stages — registered in successive multicenter clinical trials of the German Society of Pediatric Oncology — could be examined for N-myc amplification, chromosome 1-ploidy and — structure, CD₄₄ std. expression (in tumor tissue, and also in patients sera).Eightyseven (= 43%) of these infants had a non-localized, disseminated neuroblastoma, mainly involving sympathetic nerve tissue, lymphnodes, liver, skin, bone marrow and bones (46 patients were classified into the 4_s group, 41 patients in the true 4 group).If the clinical classification between stage 4 and stage 4_swas neglected, then 17 of these infants (= 20%) had N-myc amplification (4—64 copies) with 16 already dead. Seven of 9 examined patients with true stage 4 had chromosome 1p aberrations (with N-myc amplification in 5), and among the dead there were 2 with CD₄₄ negative expression.In another series, serum CD₄₄ std. was measured by ELISA, and the highest (significantly different) Kruskal-Wallis mean rank values (147.8) were found in infants (n = 6) with stage 4_s compared to the low mean-rank-value of 71.9 in patients with stage 4 (n = 65). Stage 1—3 patients (n = 42) had values of 99.8—88.6.Thus, infants with disseminated neuroblastomas, showing non-diploidy, normal chromosome 1p structure, non-N-myc amplification and high CD₄₄ std. expression in tumor tissue, and also high CD₄₄ std. values in serum, will have the highest chance of survival due to tumor-non-progression.On the other hand, N-myc amplification in the tumor cells was found to be characteristic for stage 4_s neuroblastoma patients with tumor progression (n=6). Therefore, 4_s neuroblastoma-patients with N-myc amplified tumors should be aggressively treated like true stage 4 tumor patients!