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!     

Surgical Resection and Intraperitoneal Chemotherapy for Recurrent Abdominal Sarcomas

Background: Recurrent abdominal sarcomas have an extremely high rate of recurrence and poor overall survival. A prospective study was initiated to assess the feasibility, toxicity, and benefit of surgical resection and intraperitoneal chemotherapy for improving local control of disease and overall survival.Methods: Fifty-four patients underwent surgical excision of all gross disease and postoperative intraperitoneal chemotherapy with mitoxantrone. Thirty-five patients had peritoneal disease only (stage II), and 19 patients had peritoneal disease with hepatic metastases (stage III).Results: Nine (17%) patients remain free of disease with a mean follow-up of 37 months. The remaining 45 patients (83%) have had recurrence, with a mean interval to recurrence of 11 months. Stage (P 5.001) and grade (P 5.005) were the only two variables found to significantly affect recurrence. There was an overall peritoneal recurrence rate of 48% and an overall hepatic failure rate of 69%. Nineteen (35%) of the patients are alive, with a mean follow-up of 46 months. The overall 5-year survival was 31%. The 5-year survival for stage II patients was 46%; for stage III patients, it was only 5%. Stage (P 5.001) and grade (P 5.056) were the only two variables found to significantly affect survival. There were no treatment-related deaths, and only 5 patients (9%) developed local complications.Conclusions: Aggressive surgical resection and intraperitoneal chemotherapy for recurrent abdominal sarcomas is a feasible treatment approach with minimal toxicity. Although this treatment had little effect on the hepatic spread of this disease and thus overall survival, it appears to have significantly lowered the rate of peritoneal recurrence and may provide a survival benefit for patients with disease limited to the peritoneum.     

Effects of computer-assisted documentation in orthopedic surgery on budget and reimbursement

Summary Since 1995 German health maintenance laws require hospitals to document and code all referals, admissions and discharges using the 4-digit ICD. Operative procedures are documented and coded using the ICPM. Beginning in January 1996, reimbursement for health services requires a diagnosis-related billing and payment for special procedures. The decision for billing is based on documented diagnosis and therapy. This extended request for documentation makes an online access to diagnosis and therapy with a computer-assisted coding system advisable. In 1996 in our hospital each diagnosis and operation was manually documented and coded on a form. Since the beginning of 1997, documentation and coding has been exclusively computer-assisted. On the basis of documented diagnosis and therapy the computer provides the route of reimbursement. Retrospectively we evaluated the number of charged diagnosis-related billings and payments for special procedures from January to April of 1996 and 1997. It became evident that with computer-assisted documentation and coding the number of detected and charged diagnosis-related billings and payments for special procedures was significantly increased in comparison with the previous year.      

Bias due to incomplete follow up in a cohort study

AIM: To investigate the bias introduced by incomplete follow up in a cohort study of ocular outcome after premature birth. METHODS: A geographically defined cohort of children born before 32 weeks' gestation was prospectively recruited at birth to study the ocular outcome at 2 years. On the basis of attendance at 2 years, the children's families were allocated to one of three groups: group 1 attended for follow up, group 2 were difficult to trace, and group 3 were very reluctant for assessment. All children were examined by a single ophthalmologist, masked to these groupings. RESULTS: 558 children (98.8% of study group) were examined, of whom 505 were in group 1, 20 in group 2, and 33 in group 3. The groups which were more difficult to study (groups 2 and 3) showed a significantly higher prevalence of ocular abnormalities, including strabismus (p=0. 02) and cicatricial retinopathy of prematurity (p=0.002) compared with those attending for follow up. Further, not all of these cases could have been identified by review of the children's previous records. Ocular abnormalities would be underestimated by 16% (11.3% in group 1 compared with 13.4% in the total cohort, p=0.77). CONCLUSIONS: This study suggests that the prevalence of abnormalities would be underestimated by incomplete follow up, as those subjects who were most difficult to obtain for study had a significantly higher prevalence of abnormalities.