Surface behavior of axolemma monolayers: Physico-chemical characterization and use as supported planar membranes for cultured Schwann cells

The axolemma membrane forms a stable and reproducible monomolecular layer at the air-aqueous interface. The major lipids and proteins are present in this monolayer in molar ratios similar to the original membrane. Acetylcholinesterase and Na-K-ATPase activities are preserved in the monolayer to levels of 64% and 25%, respectively. The total lipid fraction forms a homogeneously mixed phase. The presence of proteins in the monolayer introduces surface inhomogeneties. Among other features, this is revealed by the presence of two values of lateral pressure at which the monolayer shows partial or total collapse: a broad partial collapse at surface pressures between 13 to 30 mN/m and a sharp collapse point at 46 mN/m. The average molecular areas, the broad collapse point, and the variation of the surface potential per molecule suggest the relocation of protein components at surface pressures between 13 to 30 mN/m. The behavior is consistent with the extrusion and exposure of proteins toward the aqueous medium that depends on the lateral pressure. Schwann cells grown on coverslips coated with axolemma monolayers at 13 mN/m (beginning of the broad collapse) and 34 mN/m (above the broad collapse) recognize the difference in the surface organization of axolemma caused by the lateral pressure which affects their proliferation, morphology, and spatial pattern of organization. Our results show for the first time that response of Schwann cells depends on the intermolecular organization of the axolemma surface with which they interact. These results suggest that the local expression of putative surface molecules of axolemma that may mediate membrane recognition and the signalling of morphological and proliferative changes can be modulated by long range supramolecular properties. © 1993 Wiley-Liss, Inc.     

Alcohol consumption and impaired glycoregulation results in a population of 6665 salaried employees

Alcohol consumption and glycosuria were found to be associated (p < 0.001) in a population of 6571 salaried employees who underwent a systematic examination. The prevalence of glycosuria was found to range from 1.3% among 2609 non-drinkers to 5% among 816 heavy drinkers (six glasses or more of alcoholic beverage daily). This association was still significant after adjustement for age, sex and body mass index. Similarly, a positive association was observed between fasting glycemia and alcoholic intake in a subgroup of 998 subjects when such a result was available (p < 0.05).     

Uroscopy in the 21st century: high-field NMR spectroscopy

From the experiments described, it can be seen that there are different research approaches that can be taken and these are summarized in Table 1. Whereas much scientific research is principally hypothesis led, there remains, nevertheless, an important place for exploratory research. High resolution NMR can measure, directly and simultaneously, a wide range of endogenous metabolites in biological fluids and has the unique capability of providing structural information on the metabolites detected. It has proved to be a powerful research tool with which to study inherited metabolic diseases, renal disease, drug metabolism, and toxicity, and can be used to monitor the effects of drug therapy. For instance, by using a library of experimental toxins one can map the metabolic profile of site-specific nephron injury. With this approach in man one could eventually take an unknown disease such as Balkan nephropathy and predict the initial site of tubular injury, the mode of injury and therefore the kind of toxin capable of producing that injury. NMR spectroscopic techniques are still advancing rapidly, with ever increasing sensitivity and sophistication of NMR pulse sequences to enhance structural elucidation in complex mixtures. Given the advances in directly coupled HPLC-NMR and even HPLC-NMR-mass spectroscopy it is likely that these technologies in conjunction with pattern recognition will make major contribution to our understanding of renal processes and provide new diagnostic insights in the 21st century.      

Invasive micropapillary carcinoma of the breast is associated with chromosome 8 abnormalities detected by comparative genomic hybridization

Invasive micropapillary carcinoma (IMC) of the breast is a rare variant of invasive ductal carcinoma (IDC) characterized by unique histology and an extremely high incidence of lymph node metastases (approximately 95%). Comparative genomic hybridization (CGH) was used to characterize DNA extracted from 16 archival IMC cases to identify clonal genetic changes associated with this unique and highly metastatic cancer subtype. The average number of chromosomal alterations per IMC tumor was 7.4 +/-2.9 (3.4 gains and 3.9 losses), fewer than the number that we have observed in IDCs not otherwise specified (9.5 +/-6.6), IDCs with erbB-2 gene amplification (12.6 +/-5.9), and invasive lobular carcinomas (8.2 +/-5.5). The mean number of changes in IMC was significantly higher than we have observed in the rarely metastasizing tubular subtype of IDC (3.9 +/-2.3, P = 0.001), but less than the more aggressive subset of erbB-2-amplified IDC (P = 0.02). Remarkably, 100% of IMCs demonstrated loss involving the short arm of chromosome 8 (8p). Six cases showed loss of the entire 8p arm, whereas in 10 cases the loss was limited to the distal portion (8p21-pter) with localized gain of proximal 8p (8p11-p12). A reciprocal gain of 8q was detected in 14 cases (88%). Other common alterations included loss of 17p in 50% of tumors and loss of 16q in 50% of IMC cases. Gains of 17q (38%), 1q (31%), and 16p (25%) were also commonly detected. In comparison, IDCs (not otherwise specified), IDCs of the tubular subtype, and invasive lobular carcinomas showed only modest 8p loss (33%, 28%, and 13%, respectively). This region of chromosome 8 may contain 1 or more genes whose loss leads to this particular histology and/or the lymphotrophic phenotype associated with this histopathologic pattern.     

Decision support in psychiatry – a comparison between the diagnostic outcomes using a computerized decision support system versus manual diagnosis

Background  

Correct diagnosis in psychiatry may be improved by novel diagnostic procedures. Computerized Decision Support Systems (CDSS) are suggested to be able to improve diagnostic procedures, but some studies indicate possible problems. Therefore, it could be important to investigate CDSS systems with regard to their feasibility to improve diagnostic procedures as well as to save time.     

Immunohistochemical and ultrastructural analysis of a mammary cystic hypersecretory carcinoma

Cystic hypersecretory carcinoma (CHC) is a rare variant of intraductal carcinoma. A CHC in a 50-year-old woman was excised and processed for light and electron microscopy and immunohistochemistry. The tumor had a marked cystic appearance. The walls of the cysts consisted of epithelial and myoepithelial cells and a well-developed basement membrane. The epithelial cells contained well-developed rough-surfaced endoplasmatic reticulum and Golgi apparatus. Secretory granules were not detected, with the exception of a few mucus-producing cells. The secretion was predominantly homogenous, reminiscent of thyroid colloid, and demonstrated distinct PAS positivity. The cells displayed a strong labeling with epithelial membrane antigen (EMA) and EMA-positive structures were observed within the intraluminal secretion, too. Some of these were stained by alcian blue. In addition, the colloid-like material was admixed with mucus showing a filamentous internal structure and lipid droplets resulting in some heterogenity of the secretion. Intraductal micropapillary proliferation in some of the cysts and adjacent nondistended ducts was a further defining feature of the tumor. Steroid hormone receptor and Ki-67 proliferation marker immuno his Tochemistry showed scattered positivity among the tumor cells. These results are in agreement with previous observations and further clarify the nature of this low-grade in situ cancer.     

Cytomorphometric parameters in exfoliated cells as biomarkers in head and neck cancer chemoprevention

Quantitative DNA analysis has often been proposed as a potential tool capable of detecting preneoplastic tissue and as such to function as an intermediate endpoint in cancer chemoprevention trials. The first aim of this study was to test whether cytomorphometric parameters could be used to detect field cancerization characteristics in cytological preparations of oral mucosa. Cytomorphometric parameters in exfoliated cells of apparently normal oral mucosa of head and neck cancer patients were compared with those of healthy controls. The second aim was to assess the value of these parameters subsequently as intermediate endpoint biomarkers in the mucosa of 70 patients receiving N-acetylcysteine and/or retinyl-palmitate as chemopreventive drugs. No differences were detected between 'high risk' and healthy mucosa, nor were differences observed before and after treatment.     

Local narratives of sexual and other violence against children and young people in Zanzibar

Understandings of violence, and especially sexual violence against children, must be situated within the local context. The 2009 Violence against Children Survey in Zanzibar indicated that 6% of girls and 9% of boys reported having experienced sexual violence before the age of 18 years. This paper reports on an in-depth qualitative study conducted in Zanzibar to provide further insights to these findings by examining the circumstances for sexual and other violence against children in Zanzibar. Twenty-four in-depth interviews with young people and 18 focus-group discussions with young people and adults were conducted in rural and urban Zanzibar. A further 8 interviews were conducted with parents and key stakeholders in government and NGO offices that provide services for children. The findings revealed that religious and cultural practices, which form the foundation of Swahili culture in Zanzibar, provide a moral frame for childhood development, but structural factors make children vulnerable to sexual violence. Both boys and girls are vulnerable to sexual violence in the home, neighbourhood, at school and, in particular, at madrasa or Qur’anic schools. As religion and culture are strong influences on childhood, preventing sexual violence at madrasa schools would strengthen the positive aspects of religious teachings for ensuring a safe childhood.