Formation of unilamellar liposomes from total polar lipid extracts of methanogens

Unilamellar liposomes were formed by controlled detergent dialysis of mixed micelles consisting of acetone-insoluble total polar lipids extracted from various methanogens and the detergent n-octyl-beta-D-glucopyranoside. The final liposome populations were studied by dynamic light scattering and electron microscopy. Unilamellar liposomes with mean diameters smaller than 100 nm were obtained with lipid extracts of Methanococcus voltae, Methanosarcina mazei, Methanosaeta concilii, and Methanococcus jannaschii (grown at 50 degrees C), whereas larger (greater than 100-nm) unilamellar liposomes were obtained with lipid extracts of M. jannaschii grown at 65 degrees C. These liposomes were shown to be closed intact vesicles capable of retaining entrapped [14C]sucrose for extended periods of time. With the exception of Methanospirillum hungatei liposomes, all size distributions of the different liposome populations were fairly homogeneous.     

Novel systemically active antagonists of the glycine site of the N-methyl-D-aspartate receptor: electrophysiological, biochemical and behavioral characterization

A series of novel tricyclic pyrido-phthalazine-dione derivatives was tested for antagonistic effects at the strychnine-insensitive modulatory site of the N-methyl-D-aspartate (NMDA) receptor (glycineB). All compounds displaced [3H]MDL-105,519 binding to rat cortical membranes with IC50 values of between 90 nM and 3.6 microM. In patch-clamp experiments, steady-state inward current responses of cultured hippocampal neurons to NMDA (200 microM, glycine 1 microM) were antagonized by these same compounds with IC50 values of 0.14 to 13.8 microM. The antagonism observed was typical for glycineB antagonists, i.e., they induced desensitization and their effects were not use or voltage dependent. Moreover, increasing concentrations of glycine were able to decrease their apparent potency. Much higher concentrations (>100 microM) were required to antagonize alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid-induced currents. They were potent, systemically active NMDA receptor antagonists in vivo against responses of single neurons in the rat spinal cord to microelectrophoretic application of NMDA with ID50 values in the low milligram per kilogram i.v. range. They also inhibited pentylenetetrazol-, NMDA- and maximal electroshock-induced convulsions in mice with ED50 values ranging from 8 to 100 mg/kg i.p. The duration of anticonvulsive action was rather short but was prolonged by the organic acid transport inhibitor probenecid (200 mg/kg). The agents tested represent a novel class of systemically active glycineB antagonists with greatly improved bioavailability.     

Perceived family criticism and primary care utilization: psychosocial and biomedical pathways

We explored the relationship of perceived family criticism to subsequent healthcare utilization in patients attending a family medicine center. We examined: a) the relationship of perceived criticism to subsequent utilization for biomedical and psychosocial/somatic problems; b) the mediating effects of self-rated mental health and physical function; and c) the mediating effects of social support. The analyses were adjusted for age, sex, race, education, health insurance, and martial status. Higher perceived criticism predicted more psychosocial/somatic and biomedical visits. The relationship of perceived criticism with psychosocial/somatic visits was entirely mediated through self-rated mental health. The relationship of perceived criticism with biomedical visits was partly mediated through self-rated physical function and, in part, independent. Social support played no role in explaining these relationships. Further research is needed to determine whether lowering perceived family criticism lowers primary care utilization.     

Assessment of nutritional status in CAPD patients: serum albumin is not a useful measure

INTRODUCTION: In CAPD patients serum albumin is frequently used as an index of nutritional status, although it is recognized that hypoalbuminaemia may be caused by many factors. We have further examined the relationship between serum albumin and nutrition. METHODS: Nutritional status was assessed by biochemistry, anthropometry, mid-arm muscle circumference, muscle strength (hand grip and back), and lean body mass (from anthropometry, creatinine kinetics and bioimpedance) in a group of 76 stable CAPD patients. Correlations between biochemical and nutritional parameters were sought and data were compared between patient groups defined by serum albumin (> or = 37 vs < 37 g/l on two occasions 2 months apart) and separately according to subjective global assessment score (normal nutrition, A vs mild to moderate, B, and severe, C, malnutrition). RESULTS: In patients with a low SGA score, actual body weight, body mass index, mid-arm muscle circumference, lean body mass, subscapular skinfold thickness, hand grip strength (males and females) and iliac and triceps skinfold thicknesses and back strength (females only) were all significantly less than in patients with a normal SGA score. In contrast, none of these variables differed in either gender when patients were compared according to serum albumin. Serum albumin was correlated with serum creatinine (r = 0.45, P = 0.01), daily urine protein excretion (r = -0.42, P = 0.02) and uncorrected weekly creatinine clearance (r = -0.39) in females, but not with any index of body composition in either gender. CONCLUSION: Whilst SGA identified a patient group with significantly abnormal body mass, muscle mass and muscle strength, serum albumin did not. Serum albumin is not a useful marker of malnutrition in stable patients on CAPD.     

Outcome of subarachnoid haemorrhage. An analysis of surgical variables, cognitive and emotional sequelae related to SPECT scanning

A group of 48 patients, consecutive apart from exclusions, from a 1-year series of 60 cases of aneurysmal subarachnoid haemorrhage (SAH), was reviewed, in respect of clinical and radiological features, surgical management, clinical outcome, psychological distress and psychometric status, the neuropsychological assessment being compared with a closely-matched group of controls, the postoperative assessment being accompanied by a single positron emission computed tomogram (SPECT) scan. A review of those features which might have been expected to have a bearing on cognitive outcome (CT abnormalities at the outset, angiographic vasospasm, operative aneurysmal leakage, temporary vessel occlusion) failed to show a significant difference on cognitive tests. There was, however, a cognitive deficit shown by the patient group as a whole, when compared with the controls. Thus, SAH itself, the initial insult, would appear to be the essential factor in the production of persistent cognitive deficits.     

Higher order models on the eigenfrequency analysis and optimal design of laminated composite structures

This paper deals with the structural optimization of multilaminated composite plate structures of arbitrary geometry and lay up, using single layer higher order shear deformation theory discrete models. The structural and sensitivity analysis formulation is developed for a family of C⁰ Lagrangian elements. The design sensitivities of free vibration response for objective and/or constraint functions with respect to ply angles and ply thickness are presented. The objectives of the design are the maximization of natural frequencies of specified modes and/or the minimization of the structure weight or volume. The accuracy and relative performance of the proposed discrete models are compared and discussed among developed elements and alternative models. Several test designs are optimized to show the applicability of the proposed refined discrete models.     

Effect of ethanol on human placental transport and metabolism of adenosine

It has been suggested that adenosine is involved in the acute effects of ethanol in a number of tissues. The present study was undertaken to evaluate the role of adenosine on the vascular responses of perfused isolated human placental cotyledons after the acute administration of ethanol. The possibility that ethanol may effect the uptake and metabolism adenosine was also investigated. Uptake of adenosine was studied using the single-circulation paired-tracer dilution technique. Both adenosine and ethanol caused a dose-related increase in perfusion pressure of placental lobules. Pharmacologically relevant concentrations of ethanol (10-65 mM) significantly inhibited the uptake of [3H]adenosine between 25 and 50 per cent. Thin-layer chromatographic analysis of the perfusate after the administration of ethanol showed in a 17.9 +/- 0.6 per cent reduction of [3H]adenosine metabolism. These findings support the working hypothesis that placental adenosine, at least partially, mediates the placental disturbance elicited by the administration of acute ethanol, which may contribute to the pathogenesis of fetal alcohol syndrome.     

Characterization of sulfonated poly(styrene–divinylbenzene) and poly(divinylbenzene) and its application as catalysts in esterification reaction

Polymeric supports based on divinylbenzene (DVB) were prepared by aqueous suspension polymerization in presence or absence of styrene (S), using toluene and n‐heptane as diluents of the monomers. Poly(S–DVB) and poly(DVB) were sulfonated with sulfuric acid in presence of 1,2‐dichloroethane. The influence of the morphological structure of the supports and as a consequence of the catalyst on the esterification reaction of acetic acid with n‐butanol was evaluated. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 3616–3627, 2006     

Immunoradiometric assay of Ca 125 in breast cystic fluid

Ca 125 was assayed in serum and in breast cyst fluid of 78 patients with GCD. Levels of the marker in cyst fluid are generally < 30 U/ml. More significative results were found in relation to cysts relapse. In apocrine cysts relapse levels were higher than 270 U/ml, in serum cysts not relapsed levels were between 31-270 U/ml. Ca 125 could have a significative role in cell differentiation and its control.