Diagnostic and therapeutic value due to suspected diagnosis, long-term complications, and indication for sural nerve biopsy

In order to elicit the usefulness of sural nerve biopsy we retrospectively evaluated the courses of disease of every patient, who underwent this procedure in our department between January 1995 and March 2000. Sixty seven patients with the suspected diagnosis of peripheral neuropathy could be included. From these chart reviews and patient questionings were done. Inflammatory-demyelinating neuropathies were suspected in 14 patients (20.9%), specific histological findings confirmed diagnosis in 50% of these patients and resulted in therapy. In cases of polyneuropathy of unknown etiology (46 patients, 68.6%) diagnosis was made in 11 patients (23.9%), and lead to therapy in 9 patients (19.6%), merely. In all, diagnostic consequences arouse in 32.8%, therapeutic consequences in 26.9%. The follow-up of 47 patients (mean 24.4 months) found chronic pain in the distribution of the sural nerve in 14 patients (29.8%), dysesthesia in 22 patients (46.8%), and persistent sensory loss in 34 patients (72.3%). Only 24 patients (51.1%) would submit to biopsy again. Because of high complication rates and poor results we conclude that sural nerve biopsy should be done only in carefully selected cases after thorough clinical work-up, and should be limited to cases of suspected inflammatory neuropathies, collagenoses and immunologic neuropathies, and hereditary neuropathies.     

Estrogen as an adjuvant therapy to antipsychotics does not prevent relapse in women suffering from schizophrenia: results of a placebo-controlled double-blind study

The expected therapeutic effect of estrogen as an adjunct treatment to antipsychotics in women suffering from schizophrenia for relapse prevention was to be tested under real-life conditions. A multicenter, randomized, placebo-controlled, double-blind, cross-over study based on an A-B-A-B (and/or B-A-B-A) design was applied. Forty-six hypoestrogenic women with schizophrenia hospitalized for the first time or repeatedly were included in the study. Their average age was 37.9 and they had been suffering from schizophrenia for 8.4 years. During the drug treatment phases, they received a three-phase estrogen-gestagen combination drug (17beta-estradiol+norethisterone acetate) in addition to an antipsychotic drug. Significant effects of the adjuvant hormone replacement therapy on the estradiol levels could be observed, and high and low levels of estradiol prevailed in the active drug and placebo phases, respectively. We did not find any difference either in defined relapse events or in the psychopathology between estradiol replacement and placebo phases. Neither did the required antipsychotic doses or the tolerance data differ between the two phases. Thus, the results of our study do not confirm the hypothesis that a combined estradiol/antipsychotic therapy is superior to an antipsychotic monotherapy for relapse prevention.     

Developing and validating a stress appraisal measure for minority adolescents

Although there are a number of measures designed to assess the cognitive appraisal of stress in adult populations, currently there are no measures that are specifically designed to assess this important construct in adolescents. To overcome this limitation, the factorial validity and dimensionality of a dispositional measure of stress appraisal was examined in the current study. Using a multiethnic adolescent sample, both exploratory and confirmatory factor analyses resulted in a three-factor representation of appraisal. The three factors included two primary appraisal dimensions (Threat and Challenge) and one secondary appraisal dimension (Resources). This three-factor model, however, is inconsistent with four- and six-factor models found previously in adult samples. Thus, these findings suggest that the cognitive appraisals made by adolescents are less complex or differentiated than those of adults. Moreover, these findings suggest that dispositional measures are relevant for adolescent samples and should be incorporated into stress and coping paradigms.     

Pathways to self-esteem in late adolescence: the role of parent and peer attachment, empathy, and social behaviours

The goal of this study was to examine both the direct and indirect relations of parent and peer attachment with self-esteem and to examine the potential mediating roles of empathy and social behaviour. 246 college students (M age = 18.6 years, S.D. = 1.61) completed self-report measures of parent and peer attachment, empathy, social behaviour, and self-esteem. Structural equation modelling revealed that parental attachment had mostly direct effects on self-esteem. Among females, the links between peer attachment and self-esteem, however, were entirely mediated by empathy and prosocial behaviour. The findings from this study suggest that although close supportive relationships with parents and peers are related to adolescent self-esteem, these links are complex.     

Tele-echocardiography in paediatrics

Echocardiographic images can be transmitted over increasing distances with less cost and better quality thanks to advances in the field of telecommunications. This technological support can be used to detect heart defects in newborns and children in remote situations. The intent of this study was to confirm the feasibility and usefulness of telemedical communication for echocardiographic evaluation of paediatric cardiovascular disease. A total of 214 echocardiographs were performed in 194 children at a remote hospital by an experienced sonographer in paediatric echocardiography. These echocardiograms were transmitted to a distant tertiary care paediatric cardiology centre using a telemedicine link across three ISDN lines. There an experienced paediatric cardiologist interpreted the tele-echocardiograms. Tele-distant diagnoses were prospectively documented and compared with the diagnoses made subsequently on direct consultation and echocardiography. The quality of transmitted echocardiographic images was sufficient for evaluation except for one case. In 191 children (98%), the remote echocardiographic diagnosis was correct as confirmed by follow-up face to face consultations. Three cases were diagnosed incorrectly. CONCLUSION: our results confirm that accurate and rapid diagnosis can be provided by tele-echocardiography in neonates and children. This facilitates the appropriate care of these patients as expensive and potentially dangerous long-distance transfers can be avoided.     

Conformational-relaxation models of single-enzyme kinetics

Fluorescent spectroscopy experiments with single-enzyme molecules yield a large volume of statistical data that can be analyzed and interpreted using stochastic models of enzyme action. Here, we present two models, each based on the mechanism that an enzyme molecule must pass through a sequence of conformational transformations to complete its catalytic turnover cycle. In the simplest model, only one path leading to the release of product is present. In contrast to this, two different catalytic paths are possible in the second considered model. If a cycle is started from an active state, immediately after the previous product release, it follows a different conformational route and is much shorter. Our numerical investigations show that both models generate non-Markovian molecular statistics. However, their memory landscapes and distributions of cycle times are significantly different. The memory landscape of the double-path model bears strong similarity to the recent experimental data for horseradish peroxidase.