Surface activation of Concorde by Be-7

Activation analysis of two airframe components from the Concorde aircraft has identified the presence of Be-7, a nuclide found by other investigators that was deposited on the forward edge of the Long Duration Exposure Facility (LDEF) structure. The results of the Concorde analysis indicate that this phenomenon is very much a surface effect, and that the areal densities of the Be-7 are comparable to those found for LDEF. The collection of Be-7 by the aircraft must be greater than in the case of LDEF (since duration for which Concorde is accumulating the nuclide is shorter) and is of the order of 1.2 to 41 nuclei/sq cm(-)s(exp -1) depending upon assumptions made regarding the altitude at which collection becomes appreciable, and the efficiency of the process which removes the radionuclide

The precision of international market sampling for North Sea herring and its influence on assessment

Market sampling is a key source of data for catch-at-age-based assessment. Little has been documented about the influence of potential error in these data on the precision of assessments and the management information they produce. This paper presents the results of a study of the precision of North Sea herring fish market sampling carried out by the UK, Denmark and the Netherlands. Data from eight years of market sampling were analysed to obtain the precision of estimated numbers-at-age in the catch. The market sample data was then used to estimate 1000 realisations of the international catch-at-age and mean weightsat- age in the catch. Three methods of estimating the variability of missing catch data were used and three options for the catch-at-age matrices were computed. These base datasets were utilised to obtain 1000 assessments conditional on the ICA (Integrated Catch-at-age Analysis) model. From the outcome of these assessments the influence of the market sampling programmes on the management of the stock are presented as 95␌onfidence intervals on the main management parameters (recruitment, SSB, F0-1 and F2-6). In addition, the influence of missing data is estimated. The implications of our conclusions on the requirements from a market sampling programme are discusse

Increased activity of 6-phosphogluconate dehydrogenase and glucose-6-phosphate dehydrogenase in purified cell suspensions and single cells from the uterine cervix in cervical intraepithelial neoplasia.

The activities of 6-phosphogluconate dehydrogenase and glucose-6-phosphate dehydrogenase have been measured in squamous epithelial cells of the uterine cervix from normal patients and cases of cervical intraepithelial neoplasia (CIN). A biochemical cycling method, which uses only simple equipment and is suited to routine use and to automation, was applied to cells separated by gradient centrifugation. In addition, cells were examined cytochemically, and the intensity of staining in the cytoplasm of single whole cells was measured using computerised microcytospectrophotometry. Twenty per cent of cells in samples from normal patients (n=61) showed staining intensities above an extinction of 0.15 at 540 nm, compared to 71% of cases of CIN 1 (n=14), 91% of cases of CIN 2 (n=11) and 67% of cases of CIN 3 (n=15). The cytochemical data do not allow definitive distinctions to be made between different grades of CIN whereas the biochemical assay applied to cell lysates shows convincing differences between normal samples and cases of CIN. There are no false negatives for CIN 3 (n=14) and CIN 2 (n=10) and 11% false negatives for CIN 1 (n=9) and 14% of false positives for normal cases (n=21). The results of this preliminary study with reference to automation are discussed [corrected]

Maternal and Newborn-care Practices During Pregnancy, Childbirth, and the Postnatal Period: A Comparison in Three Rural Districts in Bangladesh

The aim of this study was to examine the prevalence of maternal and newborn-care practices among women reporting a birth in the previous year in three districts in different divisions of Bangladesh. In 2003, 6,785 women, who had delivered a newborn infant in the previous year, across three districts in Bangladesh, were interviewed. Overall, less than half of the women received any antenatal care, and 11% received a minimum of four check-ups. Only 18% took iron tablets for at least four months during pregnancy. Over 90% of the 6,785 deliveries took place at home, and only 11% were attended either by a doctor or by a nurse. The mothers reported three key hygienic practices in 54% of deliveries: at\uadtendants washing their hands with soap and boiling cord-tie and blade for cutting the cord. Forty-four percent of the 6,785 infants were bathed immediately after delivery, and 42% were given colostrum as their first food. The results suggest that maternal and newborn-care remains a cause of concern in rural Bangladesh. Short-term policies to promote healthy behaviour in the home are needed, in addition to the long-term goal of skilled birth attendance

Effects of quality improvement in health facilities and community mobilization through women's groups on maternal, neonatal and perinatal mortality in three districts of Malawi: MaiKhanda, a cluster randomized controlled effectiveness trial

BACKGROUND: Maternal, perinatal and neonatal mortality remains high in low-income countries. We evaluated community and facility-based interventions to reduce deaths in three districts of Malawi. METHODS: We evaluated a rural participatory women's group community intervention (CI) and a quality improvement intervention at health centres (FI) via a two-by-two factorial cluster randomized controlled trial. Consenting pregnant women were followed-up to 2 months after birth using key informants. Primary outcomes were maternal, perinatal and neonatal mortality. Clusters were health centre catchment areas assigned using stratified computer-generated randomization. Following exclusions, including non-birthing facilities, 61 clusters were analysed: control (17 clusters, 4912 births), FI (15, 5335), CI (15, 5080) and FI + CI (14, 5249). This trial was registered as International Standard Randomised Controlled Trial [ISRCTN18073903]. Outcomes for 14 576 and 20 576 births were recorded during baseline (June 2007–September 2008) and intervention (October 2008–December 2010) periods. RESULTS: For control, FI, CI and FI + CI clusters neonatal mortality rates were 34.0, 28.3, 29.9 and 27.0 neonatal deaths per 1000 live births and perinatal mortality rates were 56.2, 55.1, 48.0 and 48.4 per 1000 births, during the intervention period. Adjusting for clustering and stratification, the neonatal mortality rate was 22% lower in FI + CI than control clusters (OR = 0.78, 95% CI 0.60–1.01), and the perinatal mortality rate was 16% lower in CI clusters (OR = 0.84, 95% CI 0.72–0.97). We did not observe any intervention effects on maternal mortality. CONCLUSIONS: Despite implementation problems, a combined community and facility approach using participatory women's groups and quality improvement at health centres reduced newborn mortality in rural Malawi

Glucocorticoid receptor activation stimulates the Na-Cl co-transporter and influences the diurnal rhythm of its phosphorylation

The sodium-chloride cotransporter (NCC) in the distal convoluted tubule contributes importantly to sodium balance and blood pressure (BP) regulation. NCC phosphorylation determines transport activity and has a diurnal rhythm influenced by glucocorticoids. Disturbing this rhythm induces “nondipping” BP, an abnormality that increases cardiovascular risk. The receptor through which glucocorticoids regulate NCC is not known. In this study, we found that acute administration of corticosterone to male C57BL6 mice doubled NCC phosphorylation without affecting total NCC abundance in both adrenalectomized and adrenal-intact mice. Corticosterone also increased the whole kidney expression of canonical clock genes: period circadian protein homolog 1 (Per1), Per2, cryptochrome 1, and aryl hydrocarbon receptor nuclear translocator-like protein 1. In adrenal-intact mice, chronic blockade of glucocorticoid receptor (GR) with RU486 did not change total NCC but prevented corticosterone-induced NCC phosphorylation and activation of clock genes. Blockade of mineralocorticoid receptor (MR) with spironolactone reduced the total pool of NCC but did not affect stimulation by corticosterone. The diurnal rhythm of NCC phosphorylation, measured at 6-h intervals, was blunted by chronic GR blockade, and a similar dampening of diurnal variation was seen in GR heterozygous null mice. These effects on NCC phosphorylation did not reflect altered rhythmicity of plasma corticosterone or serum and glucocorticoid-induced kinase 1 activity. Both mineralocorticoids and glucocorticoids emerge as regulators of NCC, acting via distinct receptor pathways. MR activation provides maintenance of the NCC protein pool; GR activation dynamically regulates NCC phosphorylation and establishes the diurnal rhythm of NCC activity. This study has implications for circadian BP homeostasis, particularly in individuals with abnormal glucocorticoid signaling as is found in chronic stress and corticosteroid therapy.</p

Activation of Thiazide-Sensitive Co-Transport by Angiotensin II in the cyp1a1-Ren2 Hypertensive Rat

Transgenic rats with inducible expression of the mouse Ren2 gene were used to elucidate mechanisms leading to the development of hypertension and renal injury. Ren2 transgene activation was induced by administration of a naturally occurring aryl hydrocarbon, indole-3-carbinol (100 mg/kg/day by gastric gavage). Blood pressure and renal parameters were recorded in both conscious and anesthetized (butabarbital sodium; 120 mg/kg IP) rats at selected time-points during the development of hypertension. Hypertension was evident by the second day of treatment, being preceded by reduced renal sodium excretion due to activation of the thiazide-sensitive sodium-chloride co-transporter. Renal injury was evident after the first day of transgene induction, being initially limited to the pre-glomerular vasculature. Mircoalbuminuria and tubuloinsterstitial injury developed once hypertension was established. Chronic treatment with either hydrochlorothiazide or an AT1 receptor antagonist normalized sodium reabsorption, significantly blunted hypertension and prevented renal injury. Urinary aldosterone excretion was increased ∼20 fold, but chronic mineralocorticoid receptor antagonism with spironolactone neither restored natriuretic capacity nor prevented hypertension. Spironolactone nevertheless ameliorated vascular damage and prevented albuminuria. This study finds activation of sodium-chloride co-transport to be a key mechanism in angiotensin II-dependent hypertension. Furthermore, renal vascular injury in this setting reflects both barotrauma and pressure-independent pathways associated with direct detrimental effects of angiotensin II and aldosterone

Exploiting bacterial DNA gyrase as a drug target: current state and perspectives

DNA gyrase is a type II topoisomerase that can introduce negative supercoils into DNA at the expense of ATP hydrolysis. It is essential in all bacteria but absent from higher eukaryotes, making it an attractive target for antibacterials. The fluoroquinolones are examples of very successful gyrase-targeted drugs, but the rise in bacterial resistance to these agents means that we not only need to seek new compounds, but also new modes of inhibition of this enzyme. We review known gyrase-specific drugs and toxins and assess the prospects for developing new antibacterials targeted to this enzyme