Overexpression of amyloid precursor protein of Alzheimer's type in brains of intoxicated children

The coincidence of neuronal stress induced by intoxication and an overexpression of amyloid precursor protein (APP) in the brains of children was examined. Brains of ten children accidentally intoxicated by poisonous mushroom were studied by means of immunohistochemical methods using monoclonal antibodies generated against different domains of APP and glial cell markers. Overexpression of APP was found in the brain neurons of all intoxicated children. Neurons were immunopositive with the antibodies generated against the middle (amyloid beta protein) domain of APP. No extracellular deposits were found in the tissue. Our results provided, for the first time, the evidence that overexpression of APP concomitant with the neuronal stress is age-independent phenomenon appearing not only in the brain of adults but in very young individuals as well.     

Endometrial and fetoplacental markers in pregnancies with fetal congenital nephrosis

BACKGROUND: Interview studies which employ qualitative methodology are often concerned with classifying behaviours or attitudes and an ideal sample of research subjects displays variety in the attitudes or behaviours under scrutiny. OBJECTIVE: This paper describes the development of a questionnaire which measures GPs' attitudes towards discussing smoking with patients with the intention of using this instrument to select GPs with diverse views for a qualitative interview study. METHOD: Thirteen attitude statements with an accompanying Likert-type scale were completed by 327 GPs in one FHSA area. Factor analysis of responses produced two subscales: 'perceived efficacy' and 'enthusiasm'. Reliability and validity of these were examined. RESULTS: Each subscale had good internal reliability and preliminary exploration of construct validity supported the notion that the subscales were valid. CONCLUSION: The use of this type of instrument in sampling GPs for qualitative studies could be effective for selecting subjects with a diversity of views towards the research topic.     

Indomethacin reduces contraction of isolated non-pregnant human uterine artery induced by prostaglandin F2 alpha

The purpose of this study was to explore whether cyclooxygenase products derived from endothelium or vascular smooth muscle participate in the response of human uterine artery to prostaglandin F2 alpha. Experiments were performed using human uterine arterial rings. Prostaglandin F2 alpha (0.4 nM-1 microM) induced contraction of human uterine arteries with both intact and denuded endothelium with similar potency and efficacy (pD2 values: 7.93 +/- 0.01 and 8.07 +/- 0.03 for vessels with and without endothelium respectively; maximal response values: 89.1 +/- 4.7% and 92.3 +/- 3.8% for vessels with and without endothelium respectively). Indomethacin (10 microM) significantly suppressed the maximum effects of prostaglandin F2 alpha and induced a shift towards the right of the prostaglandin F2 alpha concentration-response curves, regardless of the endothelial condition. On the other hand, in both types of preparations, OKY-046 (10 microM), an inhibitor of thromboxane synthesis, did not affect prostaglandin F2 alpha-induced contraction of human uterine arteries. It is concluded that in human uterine artery prostaglandin F2 alpha-induced contraction is mediated, at least in part, through constrictor prostanoid(s) of vascular smooth muscle origin that is not thromboxane A2.     

The effect of duration of endemic nephropathy on serum angiotensin converting enzyme activity

The effects of duration of disease on serum angiotensin converting enzyme (ACE) was measured in 60 patients with endemic nephropathy (30 men and 30 women) of age between 30 and 60 years. There were formed three groups: patients with endemic nephropathy and duration of disease less than 5 years (n = 23), patients with endemic nephropathy and duration of disease between 5-10 years (n = 17); and patients with endemic nephropathy and duration of disease 10 years and more (n = 20). The serum ACE activity was determined by the spectrophotometric method using Hip-Gly-Gly as a substrate. The activity of enzyme were expressed in units corresponding to 1 nmol of the hippuric acid that was released by the hydrolysis of Hip-Gly-Gly per minute and ml of serum. The results showed that serum ACE activity decreased in group of patients with endemic nephropathy and duration of disease 10 years and more (29.21 +/- 2.25; X +/- SEM) in comparison with group of patients with endemic nephropathy and the duration of disease less than 5 years (35.57 +/- 1.75), which was statistically significant (p < 0.03).     

Complications following major abdominal surgery in cirrhotic patients

The morbidity and mortality associated with major abdominal surgical interventions in 34 histologically proven cirrhotic patients are analyzed by the authors. The surgical interventions were carried out as urgent, absolute and elective indications. Thirty-seven general and surgical complications were observed following major abdominal surgery in 34 cirrhotics. Seven out of 34 patients died, giving a mortality rate of 21%. Suture-line insufficiency, peritonitis, sepsis and other inflammatory processes turned out to be the most common complications. Statistical analysis showed that the Child criteria, prothrombin level and white blood cell count were useful prognostic factors.     

Interfering with the inhibitory mechanism of serpins: crystal structure of a complex formed between cleaved plasminogen activator inhibitor type 1 and a reactive-centre loop peptide

BACKGROUND: Plasminogen activator inhibitor type 1 (PAI-1) is an important endogenous regulator of the fibrinolytic system. Reduction of PAI-1 activity has been shown to enhance dissolution of blood clots. Like other serpins, PAI-1 binds covalently to a target serine protease, thereby irreversibly inactivating the enzyme. During this process the exposed reactive-centre loop of PAI-1 is believed to undergo a conformational change becoming inserted into beta sheet A of the serpin. Incubation with peptides from the reactive-centre loop transform serpins into a substrate for their target protease. It has been hypothesised that these peptides bind to beta sheet A, thereby hindering the conformational rearrangement leading to loop insertion and formation of the stable serpin-protease complex. RESULTS: We report here the 1.95 A X-ray crystal structure of a complex of a glycosylated mutant of PAI-1, PAI-1-ala335Glu, with two molecules of the inhibitory reactive-centre loop peptide N-Ac-TVASS-NH2. Both bound peptide molecules are located between beta strands 3A and 5A of the serpin. The binding kinetics of the peptide inhibitor to immobilised PAI-1-Ala335Glu, as monitored by surface plasmon resonance, is consistent with there being two different binding sites. CONCLUSIONS: This is the first reported crystal structure of a complex formed between a serpin and a serpin inhibitor. The localisation of the inhibitory peptide in the complex strongly supports the theory that molecules binding in the space between beta strands 3A and 5A of a serpin are able to prevent insertion of the reactive-centre loop into beta sheet A, thereby abolishing the ability of the serpin to irreversibly inactivate its target enzyme. The characterisation of the two binding sites for the peptide inhibitor provides a solid foundation for computer-aided design of novel, low molecular weight PAI-1 inhibitors.     

Reduced growth factor requirements and accelerated cell-cycle kinetics in adult human melanocytes transformed with SV40 large T antigen

Melanomas develop with high frequency in transgenic mice in which oncogenic sequences of the SV40 DNA tumor virus have been specifically targeted to melanocytes. To investigate the role of SV40 in melanomagenesis, cultured human melanocytes were transformed with a retroviral shuttle vector encoding the SV40 large T antigen and examined for changes in cell-cycle kinetics and growth-factor dependence. Colonies expressing the viral oncogene were morphologically indistinguishable from their non-T-antigen-transformed counterparts. Also like normal melanocytes, the infected cells remained anchorage dependent and non-tumorigenic in nude mice. However, T-antigen-positive cultures exhibited significantly accelerated population doubling times, increased saturation densities with highly confluent monolayers and a three- to fourfold extended life span. Most interestingly, cell-cycle analysis revealed a measurable shift from quiescent to cycling cells in T-antigen-expressing cultures and an acquired ability to progress more rapidly through G1. Moreover, T-antigen-positive melanocytes proliferated in the absence of PMA and required markedly reduced levels of exogenous bFGF. These studies indicate that the viral oncogen of simian virus 40 provides melanocytes with distinct growth advantages that may render these cells unusually susceptible to additional environmental challenges necessary for full expression of the malignant phenotype.     

Muscle strength in healthy people and in patients suffering from recent-onset inflammatory arthritis

Neuromuscular function was compared among 20 patients with relatively recent onset (symptomatic period 17 +/- 24 months) rheumatoid arthritis (RA) (experimental group; EG), and 20 age- and sex-matched healthy people (control group; CG). The comparison was repeated after a period of 6 months, when 16 patients had carried out progressive strength training. At baseline maximal grip strength and maximal dynamic unilateral strength of the knee extensors in the EG were significantly (P < 0.05) lower in comparison to the CG. The groups did not differ from each other in maximal isometric strength of the trunk flexors and extensors or the knee extensors. The 6-month dynamic strength training in the EG resulted in significant increases in maximal dynamic strength of the knee extensors (P < 0.001), in isometric grip strength (P < 0.001) and in isometric strength of the trunk flexors (P < 0.05) and extensors (P < 0.05) to the level of the healthy controls. Only minor changes took place in explosive strength and maximal isometric strength of the knee extensors. Erythrocyte sedimentation rate (P < 0.001), Ritchie's articular index (P < 0.01) and modified health assessment questionnaire (P < 0.01) improved significantly during the training period. The results suggest that inflammatory arthritis decreases dynamic and/or isometric muscle strength in selected muscle groups of the body already in the early stages of disease. However, progressive dynamic strength training rapidly increases the neuromuscular performance capacity of the patients even to the level of healthy people without detrimental effects on disease activity.