De novo vitamin D supplement use post-diagnosis is associated with breast cancer survival.

PURPOSE: Experimental laboratory data have indicated a protective effect of vitamin D on breast cancer progression, while epidemiological evidence is growing. Using pharmacy claims data, this study investigates the association between vitamin D supplement use initiated after a breast cancer diagnosis and associated mortality. METHODS: Women aged 50-80 years with a record of invasive breast cancer were identified on the National Cancer Registry Ireland database (n = 5417). Initiation of de novo vitamin D post-diagnosis was identified from linked national prescription data (n = 2581, 49%). Multivariate Cox proportional hazards models were used to estimate adjusted HRs (95% CIs) for breast cancer-specific mortality. RESULTS: There was a 20% reduction in breast cancer-specific mortality in de novo vitamin D users (modelled as a time-varying variable) compared to non-users (HR 0.80; 95% CI 0.64-0.99, p = 0.048) and the reduction was greater at 49% (HR 0.51; 95% CI 0.34-0.74, p < 0.001), if vitamin D was initiated soon after the breast cancer diagnosis (within 6 months). CONCLUSIONS: In this large national breast cancer cohort, de novo vitamin D use post-diagnosis was found to be associated with a reduction in breast cancer-specific mortality. Vitamin D, therefore, has the potential as a non-toxic and inexpensive agent to improve survival in breast cancer patients. Findings support the need for RCTs exploring the effect of vitamin D supplementation on breast cancer survival.

Morning surge in blood pressure using a random-effects multiple-component cosinor model.

Blood pressure (BP) fluctuates throughout the day. The pattern it follows represents one of the most important circadian rhythms in the human body. For example, morning BP surge has been suggested as a potential risk factor for cardiovascular events occurring in the morning, but the accurate quantification of this phenomenon remains a challenge. Here, we outline a novel method to quantify morning surge. We demonstrate how the most commonly used method to model 24-hour BP, the single cosinor approach, can be extended to a multiple-component cosinor random-effects model. We outline how this model can be used to obtain a measure of morning BP surge by obtaining derivatives of the model fit. The model is compared with a functional principal component analysis that determines the main components of variability in the data. Data from the Mitchelstown Study, a population-based study of Irish adults (n = 2047), were used where a subsample (1207) underwent 24-hour ambulatory blood pressure monitoring. We demonstrate that our 2-component model provided a significant improvement in fit compared with a single model and a similar fit to a more complex model captured by b-splines using functional principal component analysis. The estimate of the average maximum slope was 2.857 mmHg/30 min (bootstrap estimates; 95% CI: 2.855-2.858 mmHg/30 min). Simulation results allowed us to quantify the between-individual SD in maximum slopes, which was 1.02 mmHg/30 min. By obtaining derivatives we have demonstrated a novel approach to quantify morning BP surge and its variation between individuals. This is the first demonstration of cosinor approach to obtain a measure of morning surge.

Trends in vitamin D supplement use in a general female and breast cancer population in Ireland: A repeated cross-sectional study.

BACKGROUND: Vitamin D has been linked with improved survival after breast cancer diagnosis but little is known about prescribing rates. This study investigates trends in vitamin D supplement use in both a general female and breast cancer population. METHODS: Women with a breast cancer diagnosis were identified from the National Cancer Registry of Ireland (n = 19870). Women who had any vitamin D claim between 2005 and 2011 were identified from pharmacy claims data (n = 8556). Prevalence rates were calculated as a proportion of all eligible women and by age (< 55 years, ≥ 55 years). Poisson regression was used to compare rates of vitamin D prescribing across years (risk ratio (RR), 95% CI). RESULTS: There was a statistically significant increase in women with a claim for vitamin D between 2005-2011, with the largest increase among breast cancer patients aged ≥ 55 years (RR = 2.26; 95% CI, 2.11-2.42). CONCLUSION: This may have significant public health implications if associations between vitamin D and improved breast cancer survival prove to be causal.

Antibiotics for treating acute chest syndrome in people with sickle cell disease.

BACKGROUND: The clinical presentation of acute chest syndrome is similar whether due to infectious or non-infectious causes, thus antibiotics are usually prescribed to treat all episodes. Many different bacteria have been implicated as causative agents of acute chest syndrome. There is no standardized approach to antibiotic therapy and treatment is likely to vary from country to country. Thus, there is a need to identify the efficacy and safety of different antibiotic treatment approaches for people with sickle cell disease suffering from acute chest syndrome. OBJECTIVES: To determine whether an empirical antibiotic treatment approach (used either alone or in combination): (a) is effective in treating acute chest syndrome compared to placebo or standard treatment; (b) is safe in treating acute chest syndrome compared to placebo or standard treatment; (c) differs dependent on the regimen used in treating acute chest syndrome differ from each other with respect to efficacy and safety; and (d) varies between different age groups, regions or countries with respect to efficacy and safety. SEARCH STRATEGY: We searched The Group's Haemoglobinopathies Trials Register, which comprises references identified from comprehensive electronic database searches and handsearching of relevant journals and abstract books of conference proceedings. We also searched the LILACS database (1982 to May 2006) and the website: http://www.clinicaltrials.gov (May 2006). Date of most recent search of the Haemoglobinopathies Trials Register: February 2007. SELECTION CRITERIA: We searched for published or unpublished randomised controlled trials. DATA COLLECTION AND ANALYSIS: Each author intended to independently extract data and assess trial quality by standard Cochrane Collaboration methodologies, but no eligible randomized controlled trials were identified. MAIN RESULTS: We were unable to find any randomised controlled trials on antibiotic treatment approaches for acute chest syndrome in people with sickle cell disease. AUTHORS' CONCLUSIONS: We were unable to identify randomised controlled trials on efficacy and safety of the antibiotic treatment approaches for people with sickle cell disease suffering from acute chest syndrome. Randomised controlled trials are needed to establish the optimum antibiotic treatment for this condition.

Short-term blood pressure variability over 24 h and target organ damage in middle-aged men and women.

Blood pressure variability (BPV) has been associated with cardiovascular events; however, the prognostic significance of short-term BPV remains uncertain. As uncertainty also remains as to which measure of variability most accurately describes short-term BPV, this study explores different indices and investigates their relationship with subclinical target organ damage (TOD). We used data from the Mitchelstown Study, a cross-sectional study of Irish adults aged 47-73 years (n=2047). A subsample (1207) underwent 24-h ambulatory BP monitoring (ABPM). As measures of short-term BPV, we estimated the s.d., weighted s.d. (wSD), coefficient of variation (CV) and average real variability (ARV). TOD was documented by microalbuminuria and electrocardiogram (ECG) left ventricular hypertrophy (LVH). There was no association found between any measure of BPV and LVH in both unadjusted and fully adjusted logistic regression models. Similar analysis found that ARV (24 h, day and night), s.d. (day and night) and wSD were all univariately associated with microalbuminuria and remained associated after adjustment for age, gender, smoking, body mass index (BMI), diabetes and antihypertensive treatment. However, when the models were further adjusted for the mean BP the association did not persist for all indices. Our findings illustrate choosing the appropriate summary measure, which accurately captures that short-term BPV is difficult. Despite discrepancies in values between the different measures, there was no association between any indexes of variability with TOD measures after adjustment for the mean BP.

Two-step purification and partial characterization of a variant of the Vibrio cholerae non-O1 hemolysin.

A two-step purification method using ammonium sulfate precipitation and gel filtration was developed for the purification of a variant of the El Tor hemolysin/cytolysin from supernatant fluids of a Vibrio cholerae non-O1 human isolate (strain 2194c). The toxin displayed delayed elution from a Sephacryl gel filtration column, eluting at between two and three column volumes. The molecular mass and isoelectric point of the purified 2194c toxin were 60 kDa and 5. 3, respectively. The N-terminal amino acid sequence was ASPAPANSETNTLPHVAFYI. Purified toxin was cytolytic for Chinese hamster ovary cells and erythrocytes from several animal species.

A subpopulation of neurons in the rat rostral nucleus of the solitary tract that project to the parabrachial nucleus express glutamate-like immunoreactivity.

In rodents, gustatory information is transmitted from second order neurons in the rostral nucleus of the solitary tract (rNST) to the parabrachial nucleus (PBN) in the pons. The chemical nature of this projection is unknown. Therefore, the goal of the current study was to determine if rNST neurons that project to the PBN express glutamate-like immunoreactivity. Projection neurons were retrogradely labeled following stereotaxic injection of rhodamine-filled latex microspheres into the right PBN of seven rats while glutamate-immunoreactive (GLU-IR) structures were visualized in the same tissue using an immunoperoxidase procedure. The number of single- and double-labeled neurons located in the right (ipsilateral) and left rNST, in each of the nuclear subdivisions as well as their position along the rostral-caudal axis of the rNST was determined. GLU-IR cell bodies were located throughout the rNST. Although the rostral central subdivision contained the highest percentage (33.8%) of GLU-IR perikarya, immunolabeled neurons were most concentrated (number/area of subdivision) within the medial subnucleus. The rostral third of the rNST contained the fewest (20. 5%) and lowest density of GLU-IR cell bodies. The highest percentage of rNST neurons retrogradely labeled from the PBN were located ipsilateral (85.4%) to the pontine injection site, in the middle third of the nucleus (44.2%) and within the rostral central subdivision (52.4%). Overall, 18% of the labeled rNST projection neurons were GLU-IR. The distribution of double-labeled neurons mirrored that of the projection neurons with the largest number located in the ipsilateral rNST (84.5%), middle third of the nucleus (40.5%) and rostral central subdivision (64.7%). These results indicate that glutamate may be a main component of the ascending pathway from the rNST to the PBN. In addition, since GLU-IR neurons were located throughout the rNST and most were not retrogradely-labeled, the current results suggest that glutamate may be an important neurotrans-mitter within the medulla.

Undercover careseekers: simulated clients in the study of health provider behavior in developing countries.

The simulated client method (SCM) has been used for over 20 years to study health care provider behavior in a first-hand way while minimizing observation bias. In developing countries, it has proven useful in the study of physicians, drug retailers, and family planning services. In SCM, research assistants with fictitious case scenarios (or with stable conditions or a genuine interest in the services) visit providers and request their assistance. Providers are not aware that these clients are involved in research. Simulated clients later report on the events of their visit and these data are analyzed. This paper reviews 23 developing country studies of physician, drug retail, and family planning services in order to draw conclusions about (1) the advantages and limitations of the methods; (2) considerations for design and implementation of a simulated client study; (3) validity and reliability; and (4) ethical concerns. Examples are also drawn from industrialized countries, related methodologies, and non-health fields to illustrate the issues surrounding SCM. Based on this review, we conclude that the information gathered through the use of simulated clients is unique and valuable for managers, intervention planners and evaluators, social scientist, regulators, and others. Areas that need to be explored in future work with this method include: ways to ensure data validity and reliability; research on additional types of providers and health care needs; and adaptation of the technique for routine use.

Can licensed drug sellers contribute to safe motherhood? A survey of the treatment of pregnancy-related anaemia in Nepal.

Iron-deficiency anaemia is a major cause of maternal mortality worldwide, contributing to perhaps one in five maternal deaths. According to the World Health Organization (WHO), maternal anaemia is most severe in southern Asia. Drug retail shops frequently serve as the public's first point of contact for medical care, even though many drug sellers have no training in the treatment of illness. In western Nepal, drug retailer treatment of anaemia in pregnancy was investigated using interviews, focus groups and simulated clients ('surrogates'). Research assistants posing as the husbands of anaemic pregnant women asked retailers for advice. In 112 retail shops studied, 71% of the study surrogates were recommended iron supplements for purchase. Drug recommendations often included vitamins, minerals and other ingredients not therapeutic for pregnancy-related anaemia. Retailers were found to take little case history. Fifty-seven per cent of retailers asked about the duration of the pregnancy; 40% asked no relevant questions. Advice about the drugs sold was infrequent and 59% of the surrogates received no advice of any kind other than a product recommendation. Knowledge of important referral criteria was also especially low. Although 66% of the retailers had some sort of formal training for work with pharmaceuticals, current training levels were not found to be associated with better knowledge or practice. A focused training intervention to improve retailer treatment of anaemia in pregnant women is recommended.

Effectiveness of antenatal screening for sickle cell trait: the impact on women's self-report of sickle cell trait status.

OBJECTIVES: The sickle gene frequency in the Jamaican population has not changed over a generation. It is unknown whether routine antenatal screening for sickle cell trait (SCT) has affected women's knowledge of their SCT status. The aim of this study was to compare the prevalence of self-reported SCT in parous women to the prevalence in nulliparous women, men and to the observed prevalence of SCT measured in an antenatal clinic. METHODS: All participants in the nationally representative Jamaica Health and Lifestyle Survey 2008 were asked whether they had the SCT. The impact of gender, age, educational attainment, geographical location, and pregnancy on self-reported SCT were assessed. The prevalence of SCT in women attending a large antenatal clinic concurrently was compared to that reported by women of child-bearing age in the lifestyle survey. RESULTS: Self-report significantly underestimated the prevalence of SCT (2·9% versus 10·1%, P<0·001). Those with secondary education were more likely than those with presecondary education (P = 0·01) and women more likely than men (3·2% versus 1·1%, P = 0·001) to report having SCT. Women who had been pregnant were no more likely than other women to report having SCT (3·1% versus 4·1%, P = 0·4). CONCLUSIONS: Attendance at antenatal clinic where SCT screening is routine, is not associated with increased self-report of SCT. Screening programs must ensure that, as well as technically accurate screening, there is effective communication of the results of screening for SCT to those tested to help reduce the public health burden of sickle cell disease in tropical countries.

Asthma in children with sickle cell disease and its association with acute chest syndrome.

BACKGROUND: Pulmonary complications are a major cause of morbidity and mortality in sickle cell disease (SCD). The relationship of asthma with SCD and acute chest syndrome (ACS) remains uncertain. A study was undertaken to test the hypotheses that asthma and bronchial hyperreactivity (BHR) are more common in children with SCD than in ethnic matched controls and that SCD children with atopic asthma are more likely to have recurrent episodes of ACS. METHODS: A modified International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire was administered and skin prick tests undertaken in 80 children with SCD and 80 ethnic matched controls aged 5-10 years. BHR was assessed by measurement of forced expiratory volume in 1 second before and after a bronchodilator (albuterol 200 mug) or an exercise challenge. RESULTS: Asthma (48% v 22%, p = 0.002) and BHR (p = 0.02) but not atopy were more common in children with SCD than in controls. Atopy (66.6% v 29%, p = 0.007) and asthma (80% v 40%, p = 0.005), particularly atopic asthma (53% v 12%, p<0.001), were more common in children with SCD who had suffered recurrent episodes of ACS than in those who had suffered a single or no episode. CONCLUSIONS: Asthma and BHR are more common in children with SCD than in ethnic matched controls, and atopic asthma appears to be associated with recurrent ACS. Early and effective anti-asthma therapy might reduce the pulmonary morbidity associated with SCD.

Isolation and characterization of a cytolysin produced by Vibrio cholerae serogroup non-O1.

A thermolabile toxin (molecular weight, 52 711; isoelectric point, 8.65) produced by a clinical isolate of Vibrio cholerae serogroup non-O1 was cytotoxic for Y-1 mouse adrenal cells and Chinese hamster ovary cells. The toxin lysed rabbit red blood cells and produced a hemorrhagic zone in rabbit skin. When injected intravenously into adult mice, the cytolysin was rapidly lethal and caused fluid accumulation in both 5- and 18-h rabbit ileal loops. Strains of V. cholerae that produced cytolysin but no cholerae enterotoxin were able to cause fluid accumulation in rabbit intestinal loops.

Campylobacter diarrhea in an adult mouse model.

An adult mouse (18-20 g) model was developed for studying the pathogenesis of Campylobacter isolates. Iron-loaded BALB/c mice given 10(8)-10(9) Campylobacter colony forming units by intraperitoneal injection developed a severe mucoid diarrhea within 4 h. Severe diarrhea, consisting of unformed stools containing blood, mucus, and fecal leukocytes, persisted for 24 h. Diarrheal symptoms in surviving mice resolved gradually; no diarrhea was observed 5 days after inoculation. Mice not pretreated with iron developed no diarrheal symptoms, and no severe diarrhea was produced in mice inoculated orally. A transient (less than 24 h) bacteremia occurred in mice inoculated either orally or intraperitoneally. Liver, spleen, and kidney were positive for Campylobacter for 48 h; intestinal contents were positive for 5-7 days. Mice given greater than or equal to 10(10) colony forming units showed symptoms of endotoxemia (ruffled fur, inactivity, shaking, tearing, and hypothermia) and died without diarrheal symptoms. Mice given nonpathogenic Escherichia coli strain HB101, heat-killed C. jejuni cells (greater than 10(10)), C. jejuni lipopolysaccharide extract, or purified lipopolysaccharide from either Vibrio cholerae 569B or Salmonella typhimurium showed no diarrheal symptoms.

Effect of iron concentration on toxin production in Campylobacter jejuni and Campylobacter coli.

The effect of iron concentrations in culture media on supernatant yields of campylobacter cytotonic toxin (CCT) was studied. Of the 118 Campylobacter spp. strains surveyed, 78.8% produced toxin in brucella broth or in casamino acids--yeast extract (CYE) broth. When the iron concentration of CYE was increased from 0.44 microgram/mL (7.9 microM) to 0.65 microgram/mL (11.6 microM) by the addition of ferric chloride, 94.9% of the strains were positive for toxin in a ganglioside GM1 based, enzyme-linked immunosorbent assay, using antibody to affinity-purified CCT. The addition of iron as ferrous sulfate was less effective. When four toxin-positive strains were grown in a deferrated medium of conalbumin-treated CYE with 0.04-0.08 microgram iron/mL (0.72-1.43 microM), two of the culture supernatants became negative (absorbance at 410 nm, less than 0.1 and less than 10 ng CCT/mL), and two produced about 90% less CCT but were still classified as positive (absorbance, greater than or equal to 0.1 and greater than or equal to 10 ng CCT/mL). It was therefore concluded that the production of CCT by Campylobacter spp. is influenced by iron concentration.

Prognostic factors for fibromatoses: a correlation of proliferation index, estrogen receptor, p53, retinoblastoma, and src gene products and clinical features with outcome.

BACKGROUND: The aggressiveness of fibromatoses is difficult to predict by morphologic analysis. Additional prognostic markers would be helpful for clinical management. MATERIALS AND METHODS: Proliferation index (MIB-1), p53, src, retinoblastoma gene protein products, estrogen receptor level, site and depth of lesion were correlated with incidence of recurrence in 52 patients. Superficial (47) and deep (5) fibromatoses were studied. Anatomic sites included the extremities, head, neck, trunk, and pelvis. RESULTS: Twenty (38%) lesions recurred locally. All five deep lesions recurred, but only 32% of superficial tumors recurred. Mean proliferation index for recurrent lesions was 0.82% and 0.73% for nonrecurrent fibromatoses; no significant differences were observed. Five recurrent lesions (25%) expressed estrogen receptor > 5 fmol/mg as did 31% (10 of 32) of the nonrecurrent lesions. None of the tested specimens expressed src gene product. Eight of the lesions which recurred (40%) contained p53, but only five nonrecurring tumors (16%) expressed p53. One of five deep lesions (20%) expressed p53 and 26% (12 of 47) of superficial tumors expressed p53. Forty-six percent (6 of 13) of recurrent lesions tested were retinoblastoma protein product negative, but only 33.3% (7 of 21) of nonrecurring tumors were retinoblastoma protein product negative. CONCLUSIONS: Only p53 and depth of lesion were of statistical value for the prediction of recurrence.

Purification and characterization of a CHO cell-elongating toxin produced by Aeromonas hydrophila.

A Chinese hamster ovary (CHO) cell-elongating toxin produced by Aeromonas hydrophila was purified from cell-free supernatant fluids by ammonium sulfate precipitation and fast protein liquid chromatography. The purified toxin had an isolelectric point (pl) of 3.7 and a molecular weight of 70,000 in a single band on isoelectric focusing (IEF) gels and SDS-PAGE gels, respectively. The N-terminal sequence, amino acids 1-20, and the amino acid content were determined from Western blots of the 70 kDa band. No homology with any known microbial toxin was found. CHO cell activity was not neutralized by antiserum to cholera toxin (anti-CT), and the toxin did not react with anti-CT on Western blots. The toxin did not increase cyclic AMP, cyclic GMP, or prostaglandin E2 levels in CHO cells. No cytotoxic activity was observed. Intragastric administration of purified toxin (5 x 10(4) and 5 x 10(8) CHO cell units) induced intestinal fluid accumulation in infant mice. These results suggest that this toxin may be a novel cytotonic toxin distinct from previously described toxins produced by A. hydrophila or A. sobria.

Binding of cholera toxin to Giardia lamblia.

Binding of cholera toxin to Giardia lamblia was demonstrated by two slightly different methods: an immunofluorescence technique using antibody to cholera toxin and anti-rabbit immunoglobulin G conjugated to fluorescein isothiocyanate, and a one-step fluorescence method in which G. lamblia was incubated with the B subunit of cholera toxin conjugated to fluorescein isothiocyanate.

Purification and characterization of a Chinese hamster ovary cell elongation factor of Vibrio hollisae.

The halophilic bacterium Vibrio hollisae, isolated from patients with diarrhea, produces an extracellular toxin which elongates Chinese hamster ovary (CHO) cells. We purified this toxin to homogeneity by sequential ammonium sulfate precipitation, gel filtration with Sephacryl S-200, hydrophobic interaction chromatography with phenyl-Sepharose CL-4B, ion-exchange chromatography with DEAE-Sephadex A-50, and affinity chromatography. The toxin is heat labile and sensitive to proteases, with an isoelectric point of about 6.5 and molecular weights of about 83,000 and 80,000, as estimated by gel filtration and sodium dodecyl sulfate-polyacrylamide gel electrophoresis, respectively. The toxin did not react with immunoaffinity-purified antibodies to cholera toxin in a plate enzyme-linked immunosorbent assay and in a Western blot, and its activity could not be neutralized by anti-cholrea toxin serum. Mixed gangliosides and gangliosides GM1, GD1a, GD1b, Gq1b, GT1b, GD2, GD3, GM2, and GM3 failed to block its activity. Elongation of CHO cells induced by the toxin was not accompanied by an increase in the levels of cyclic AMP. The toxin induced intestinal fluid accumulation in suckling mice. These results and the lack of homology between V. hollisae DNA and DNA coding for cholera toxin or the heat-labile toxin of Escherichia coli suggest that the V. hollisae toxin is structurally and functionally different from other CHO cell-elongating toxins.

Virulence of three clinical isolates of Vibrio cholerae non-O-1 serogroup in experimental enteric infections in rabbits.

Three Vibrio cholerae, [ill] isolates, pathogenic in both adult rabbit ligated ileal loop and infant rabbit assays, produced no heat-labile or heat-stable toxins. Their pathogenicity did not correlate with the presence of plasmids.