Microstructural dependence on relevant physical-mechanical properties on SiO2-Na2O-CaO-P2O5 biological glasses

Bioactive glasses of the system SiO2-Na2O-CaO-P2O5 have been prepared by the normal melting and annealing technique. The elastic moduli, attenuation, Vickers hardness, fracture toughness and fracture surface energy have been obtained using the known method at room temperature. The temperature dependence of elastic moduli and attenuation measurements have been extended over a wide range of temperature from 150 to 500 K. The SiO2 content dependence of velocities, attenuation, elastic moduli, and other parameters show an interesting observation at 45 wt% of SiO2 by exhibiting an anomalous behaviour. A linear relation is developed for Tg, which explores the influence of Na2O on SiO2-Na2O-CaO-P2O5 bioactive glasses. The measured hardness, fracture toughness and fracture surface energy show a linear relation with Young's modulus. It is also interesting to note that the observed results are functions of polymerisation and the number of non-bridging oxygens (NBO) prevailing in the network with change in SiO2 content. The temperature dependence of velocities, attenuation and elastic moduli show the existence of softening in the glass network structure as temperature increases.     

In vitro antiplasmodial activity of antimalarial medicinal plants used in Vietnamese traditional medicine

Among 42 extracts, prepared from 14 medicinal plants used in Vietnamese traditional medicine to treat malaria, 24 were found to have antiplasmodial activity by inhibiting the growth of the chloroquine-resistant Plasmodium falciparum strain FCR-3 with EC(50) values less than 10 microg/ml. Each medicinal plant possessed at least one active extract. The methanol extract of Coscinium fenestratum had the strongest antiplasmodial activity with EC(50) value of 0.5 microg/ml. Activity-guided fractionation led to identification of berberine as the major active constituent.     

Death from drowning: defining a new challenge for child survival in Bangladesh

The study focuses on children less than 5 years old and explores the epidemiological profile and correlates of drowning as a challenge to child survival in Bangladesh. Two data sources from Bangladesh, a cohort of 8,070 children followed for 2 years in a rural area and a nation-wide survey conducted in 1996-97 have been used. In addition, a systematic review of the literature has been conducted spanning the past two decades for analysis of drowning in children. Seventy drowning deaths were reported in the cohort and 726 deaths were reported in the national survey. Verbal autopsy and semi-structured interviews were conducted on all deaths. Drowning accounted for 43% of deaths in the cohort and 20% of deaths in 1-4-year-old children in the national survey. Most drowning deaths were in 12-23 month old children from falling into ditches and ponds. Communities provided valuable insights on possible interventions to reduce deaths due to drowning. Drowning is a newly recognized challenge for Bangladesh. Considerable research and programmatic work is required to understand the nature of the problem and develop appropriate interventions. This paper calls on aid agencies to create opportunities for drowning research and action in their work plans for the country.     

Coronary artery disease in young patients: clinical review and risk factor analysis

Fifty consecutive younger patients (< or = 40 years) with coronary artery disease, who underwent coronary angiography in National Institute of Cardiovascular Diseases were evaluated clinically and coronary risk factors were analyzed and compared with those of fifty older patients with coronary artery disease. Mean age of younger and older patients were 37.31 and 54.58 years respectively and myocardial infarction was the most common presenting complain in both the groups. Smoking and family history of premature coronary artery disease were more common in younger patients but the older patients were more diabetic and hypertensive. Central obesity and dyslipidemia did not vary between the two groups. Fifty percent of younger patients had one or two modifiable risk factors where sixty four percent of older patients had three or more modifiable risk factors. Forty four percent younger patients had hypercholesterolemia but a majority of patients had either isolated hypertriglyciredemia or decrease high density lipoprotein cholesterol or both with normal total cholesterol level but the total cholesterol and high density lipoprotein cholesterol index were more than 4.5. Younger patients had more number of normal coronary or single vessel diseases but older group had more number of triple vessel diseases. So the higher incidence of non-insulin dependent diabetes mellitus with central obesity suggesting insulin resistance along with unique profile of dyslipidemia, higher incidence of smoking and familial predisposition of premature coronary artery disease may be responsible for higher incidence of coronary artery disease at a premature younger age in this population.     

In vivo genotoxic effects of mercuric chloride in rat peripheral blood leucocytes using comet assay

DNA damage induced by Mercuric chloride (HgCl2) in leucocytes of Wistar albino male rats has been studied in vivo. The comet assay or the alkaline single cell gel electrophoresis (SCGE) assay was used to measure the DNA damage. The rats were administered orally with doses ranging from 0.0054, 0.0108, 0.0216, 0.0432 to 0.0864 mg/kg body weight (b.wt.) of HgCl2. The assay was performed on whole blood at 24, 48, 72 h, 1st and 2nd week. The reason leucocytes were used was to reflect biomarker studies in humans. A significant increase in mean comet tail length indicating DNA damage was observed at all time intervals with HgCl2 except in 2nd week post treatment when compared to controls. The mean comet tail length revealed a clear dose dependent increase from 0.0054 to 0.0432 mg/kg b.wt. A maximum increase in mean comet tail length was observed at 0.0432 mg/kg b.wt. 24 h after treatment. From 48 h post treatment, the mean comet tail lengths of all the doses gradually decreased and by week 2 of post treatment, they had approached control levels, pointing to repair of the damaged DNA. These findings suggest that the comet assay is a highly sensitive technique to study DNA damage caused by metals.     

Health gain and outcome predictors during inpatient and related day treatment in child and adolescent psychiatry

OBJECTIVE: To investigate health gain and its predictors during inpatient and associated day patient treatment. METHOD: Consecutive admissions to two inpatient units for children and young adolescents in northwest England were studied (N = 55). Ascertainments were made from multiple perspectives, including family, teacher, clinician, and an independent researcher. Measures were taken at referral, admission, discharge, and 6-month follow-up; health gain was inferred from change scores on measures. Recruitment lasted from late 1995 to 1997; follow-up was completed during 1998. Independent variables tested as predictors included assessments of presenting symptoms, therapeutic alliance, and family functioning. RESULTS: Significant health gain during hospitalization was found on most measures and sustained to follow-up. There was no symptom change during the waiting-list control condition. Health gain was predicted independently by child and parental therapeutic alliance with the unit early in hospitalization and by preadmission family functioning. Externalizing problems did well if accompanied by good alliance. CONCLUSIONS: Assessment of health gain from multiple perspectives is possible and valuable. Inpatient treatment has significant therapeutic effect. Predictors for health gain lie in process variables of therapeutic alliance and family functioning rather than presenting symptoms. The results are discussed in relation to clinical practice and future research.     

Reducing maternal mortality from eclampsia, using magnesium sulphate

Since the introduction of low dose magnesium sulphate to treat eclamptic patients at Dhaka Medical College, mortality rates have fallen from 16% to 8%. Personal communications from other centres in Bangladesh show similar findings.     

Reduced expression of the CXCR4 receptor mRNA in hepatocellular carcinoma and lack of inducibility of its ligand alpha-chemokine hIRH/SDF1alpha/PBSF in vitro

Differential cDNA displays between hepatocellular carcinoma and adjacent non-malignant tissues have previously detected a PCR product, hIRH (human intercrine reduced in hepatomas), equivalent to SDF1alpha/PBSF whose mRNA was lost from human hepatocellular carcinoma and other malignant and pre-malignant samples and malignant cell lines. There are no reports to date of the mRNA status of the receptor for hIRH/SDF1alpha/PBSF, CXCR4 in malignant tissues. We report here that there is a reduction in the mRNA expression of CXCR4 in hepatocellular carcinoma as estimated by Northern blot and RT-PCR and compared to the adjacent non-malignant tissue. The average (mean SD) tumor/normal ratio for CXCR4 mRNA expression, determined by RT-PCR, was 0.65 0.36 in 10 pairs of hepatocellular carcinomas. There was no consistent loss of CXCR4 mRNA expression in a range of malignant cell lines. The 3'-non-coding region of hIRH, had typical early response gene element sequences. Despite the presence of these 3'-elements there was no induction of hIRH gene expression in human lung carcinoma A549 cells by tumor necrosis factor alpha, interleukin-2, lipopolysaccharide or phorbol myristic acetate, nor in human melanoma cell line SB-2 by uv irradiation, under conditions which induced the homologue CXC intercrine IL-8 expression. Furthermore, there was no induction of hIRH gene expression, but rather a suppression, upon serum or cytokine addition to serum-deprived fibroblast cell lines, to an in vitro mouse bone marrow preparation, and to monocytic cell line THP-1.