392 research outputs found

    Virulence factors and antibiotic susceptibility among verotoxic non O157: H7 Escherichia coli isolates obtained from water and wastewater samples in Cape Town, South Africa.

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    Forty eight samples (30 wastewater and 18 river water) were collected between July and November, 2010, from different sources in Cape Town, South Africa in order to characterize verotoxic non O157: H7 Escherichia coli strains. Samples (1 ml) were inoculated into MacConkey broth (MB, 9 ml) and incubated at 37°C for 24 h, after which a loopful of the MB was then spread onto Eosin Methylene Blue (EMB) and further incubated for 24 h at 37°C in order to isolate E. coli. The identification of isolates was done using standard biochemical procedures; and confirmed serologically using E. coli polyvalent antisera (Bioweb, SA). Isolates were also characterized for virulence factors such as verotoxin, haemolysin, gelatinase, extended spectrum beta lactamases (ESBLs), cell surface hydrophobicity and bacterial serum resistance, as well as susceptibility (using disc diffusion method) to stem bark extracts of Curtisia dentata. Results showed the presence of different serotypes of E. coli (69 isolates in all) including 026: H11, 055, O111: NM, O126, O44, O124, O96:H9, O103:H2, O145: NM and O145:H2. Over 60% of the isolates exhibited serum resistance, haemolysin and gelatinase production, 81% exhibited cell surface hydrophobicity and over 52% produced ESBLs. Results also showed that while 60% of the isolates showed various levels of resistance to different antibiotics [ampicillin (10 μg), cefuroxime, cephalexin, ceftazidime and tetracycline (30 μg in each case) (multidrug resistance index (MDRI) values 4.20 to 5.60%)], only 28% were resistant to ethanol stem bark extracts of C. dentata (MIC, 70 to 150 mg/ml). The presence of pathogenic verotoxic antibiotic resistant E. coli in these water sources is a threat to water quality and food security and C. dentata has a potential for sourcing novel antibiotic substances for chemotherapy against these resistant pathogenic strains of E. coli.Key words: Curtisia dentata, Escherichia coli, haemolysins, cell surface hydrophobicity, gelatinase, plant extracts, verotoxins

    Compartmentalized Culture of Perivascular Stroma and Endothelial Cells in a Microfluidic Model of the Human Endometrium

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    The endometrium is the inner lining of the uterus. Following specific cyclic hormonal stimulation, endometrial stromal fibroblasts (stroma) and vascular endothelial cells exhibit morphological and biochemical changes to support embryo implantation and regulate vascular function, respectively. Herein, we integrated a resin-based porous membrane in a dual chamber microfluidic device in polydimethylsiloxane that allows long term in vitro co-culture of human endometrial stromal and endothelial cells. This transparent, 2-m porous membrane separates the two chambers, allows for the diffusion of small molecules and enables high resolution bright field and fluorescent imaging. Within our primary human co-culture model of stromal and endothelial cells, we simulated the temporal hormone changes occurring during an idealized 28-day menstrual cycle. We observed the successful differentiation of stroma into functional decidual cells, determined by morphology as well as biochemically as measured by increased production of prolactin. By controlling the microfluidic properties of the device, we additionally found that shear stress forces promoted cytoskeleton alignment and tight junction formation in the endothelial layer. Finally, we demonstrated that the endometrial perivascular stroma model was sustainable for up to 4 weeks, remained sensitive to steroids and is suitable for quantitative biochemical analysis. Future utilization of this device will allow the direct evaluation of paracrine and endocrine crosstalk between these two cell types as well as studies of immunological events associated with normal versus disease-related endometrial microenvironments

    Crystallisation route map

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    A route map for the assessment of crystallisation processes is presented. A theoretical background on solubility, meta-stable zone width, nucleation and crystal growth kinetics is presented with practical examples. The concepts of crystallisation hydrodynamics and the application of population balances and computational fluid dynamics for modelling crystallisation processes and their scaling up are also covered

    Protecting Vulnerable Research Subjects in Critical Care Trials: Enhancing the Informed Consent Process and Recommendations for Safeguards

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    Although critically ill patients represent a vulnerable group of individuals, guidelines in research ethics assert that ethically acceptable research may proceed with such vulnerable subjects if additional safeguards are in place to minimize the risk of harm and exploitation. Such safeguards include the proper obtainment of informed consent that avoids the presence of the therapeutic misconception and the assessment of decisional capacity in critically ill patients recruited for research. Also discussed in this review are additional safeguards for such vulnerable subjects, as well as the issues involved with proxy consent. Heightened awareness to principles of ethics and provision of additional safeguards to enhance protections of vulnerable subjects would help to maintain the public trust in the research endeavor

    Discomfort in children undergoing unsedated MRI

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    Magnetic resonance imaging (MRI) scans for research purposes usually do not directly benefit the children scanned, so that review boards need to assess whether the risk of harm or discomfort is minimal. This study aimed at providing empirical data on discomfort related to unsedated MRI in children aged 5–12 years. Secondary objectives were to determine whether lower age is associated with higher levels of discomfort and to investigate which other characteristics of subjects and/or procedures may be associated with higher levels of discomfort. Self-report scores, observation scores, heart rate standard deviation scores, and incremental salivary cortisol levels were obtained from 54 children aged 5–12 years with non-acute conditions undergoing diagnostic MRI. Of the 54 children, 10 scored relatively high values on the self-report score and on one or two of the other measures, and another 15 scored relatively high on the self-report score alone. Rather than an age effect, associations were found between parents’ trait anxiety and observation score values and between use of contrast fluid (requiring the insertion of a venous cannula) and high incremental salivary cortisol levels. In conclusion, MRI-related discomfort may be regarded as minimal for more than half of children aged 5–12

    Chronic kidney disease and use of dental services in a united states public healthcare system: a retrospective cohort study

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    <p>Abstract</p> <p>Background</p> <p>As several studies have shown an association between periodontal disease and chronic kidney disease (CKD), regular dental care may be an important strategy for reducing the burden of CKD. Access to dental care may be limited in the US public health system.</p> <p>Methods</p> <p>In this retrospective cohort study of 6,498 adult patients with (n = 2,235) and without (n = 4,263) CKD and at least 12 months of follow-up within the San Francisco Department of Public Health Community Health Network clinical databases, we examined the likelihood of having a dental visit within the observation period (2005-2010) using Cox proportional hazards models. To determine whether dental visits reflected a uniform approach to preventive service use in this setting, we similarly examined the likelihood of having an eye visit among those with diabetes, for whom regular retinopathy screening is recommended. We defined CKD status by average estimated glomerular filtration rate based on two or more creatinine measurements ≥ 3 months apart (no CKD, ≥ 60 ml/min/1.73 m<sup>2</sup>; CKD, < 60 ml/min/1.73 m<sup>2</sup>).</p> <p>Results</p> <p>Only 11.0% and 17.4% of patients with and without CKD, respectively, had at least one dental visit. Those with CKD had a 25% lower likelihood of having a dental visit [HR = 0.75, 95% CI (0.64-0.88)] than those without CKD after adjustment for confounders. Among the subgroup of patients with diabetes, 11.8% vs. 17.2% of those with and without CKD had a dental visit, while 58.8% vs. 57.8% had an eye visit.</p> <p>Conclusions</p> <p>Dental visits, but not eye visits, in a US public healthcare setting are extremely low, particularly among patients with CKD. Given the emerging association between oral health and CKD, addressing factors that impede dental access may be important for reducing the disparate burden of CKD in this population.</p

    Hospitalization for pertussis: profiles and case costs by age

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    BACKGROUND: Pertussis, a highly contagious respiratory illness, affects people of all ages and can have serious clinical consequences. It has been reported that from 1997–2000, 20% of all pertussis cases required hospitalization in the US. This analysis examined demographics, case fatality rate, resource use and costs of hospital care related to pertussis by age. METHODS: ICD-9 codes (033.0, 033.9) were used to identify cases of pertussis in hospital discharge databases from roughly 1,000 US hospitals in 4 states (California, Florida, Maryland, Massachusetts). Data from 1996–1999 were examined by age group. Separate analyses were done for infants (<1 year) and children (1–11 years); however, adolescent and adult cases were combined into one group (12+ years), due to the small number of cases. Databases were used to determine demographics, health service utilization and care costs. Cost estimates include accommodations, ancillary and physician services, reported in 2002 US.RESULTS:Ofthe2,518casesidentified,90. RESULTS: Of the 2,518 cases identified, 90% were infants. The inpatient case fatality rate was <1%. Of survivors, 99% were discharged home (6% with home health care); 1% required further sub-acute inpatient care. For the 2,266 infants, the mean LOS was 6 days at a cost of 9,586 per stay. Children (n = 191) had a mean LOS of 3.7 and cost of 4,729;adolescents/adults(n=61,meanage40years)stayedonaverage3.4dayswithacostof4,729; adolescents/adults (n = 61, mean age 40 years) stayed on average 3.4 days with a cost of 5,683 per hospitalization. CONCLUSION: Infants are responsible for the bulk of hospitalizations and generate higher inpatient costs. Costly hospital care occurs, however, in patients with pertussis at all ages

    The role of gender in a smoking cessation intervention: a cluster randomized clinical trial

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    <p>Abstract</p> <p>Background</p> <p>The prevalence of smoking in Spain is high in both men and women. The aim of our study was to evaluate the role of gender in the effectiveness of a specific smoking cessation intervention conducted in Spain.</p> <p>Methods</p> <p>This study was a secondary analysis of a cluster randomized clinical trial in which the randomization unit was the Basic Care Unit (family physician and nurse who care for the same group of patients). The intervention consisted of a six-month period of implementing the recommendations of a Clinical Practice Guideline. A total of 2,937 current smokers at 82 Primary Care Centers in 13 different regions of Spain were included (2003-2005). The success rate was measured by a six-month continued abstinence rate at the one-year follow-up. A logistic mixed-effects regression model, taking Basic Care Units as random-effect parameter, was performed in order to analyze gender as a predictor of smoking cessation.</p> <p>Results</p> <p>At the one-year follow-up, the six-month continuous abstinence quit rate was 9.4% in men and 8.5% in women (p = 0.400). The logistic mixed-effects regression model showed that women did not have a higher odds of being an ex-smoker than men after the analysis was adjusted for confounders (OR adjusted = 0.9, 95% CI = 0.7-1.2).</p> <p>Conclusions</p> <p>Gender does not appear to be a predictor of smoking cessation at the one-year follow-up in individuals presenting at Primary Care Centers.</p> <p>ClinicalTrials.gov Identifier</p> <p><a href="http://www.clinicaltrials.gov/ct2/show/NCT00125905">NCT00125905</a>.</p

    Impact of two recent extreme heat episodes on morbidity and mortality in Adelaide, South Australia: a case-series analysis

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    Extent: 9p.BACKGROUND: Extreme heatwaves occurred in Adelaide, South Australia, in the summers of 2008 and 2009. Both heatwaves were unique in terms of their duration (15 days and 13 days respectively), and the 2009 heatwave was also remarkable in its intensity with a maximum temperature reaching 45.7°C. It is of interest to compare the health impacts of these two unprecedented heatwaves with those of previous heatwaves in Adelaide. METHODS: Using case-series analysis, daily morbidity and mortality rates during heatwaves (≥35°C for three or more days) occurring in 2008 and 2009 and previous heatwaves occurring between 1993 and 2008 were compared with rates during all non-heatwave days (1 October to 31 March). Incidence rate ratios (IRRs) were established for ambulance call-outs, hospital admissions, emergency department presentations and mortality. Dose response effects of heatwave duration and intensity were examined. RESULTS: Ambulance call-outs during the extreme 2008 and 2009 events were increased by 10% and 16% respectively compared to 4.4% during previous heatwaves. Overall increases in hospital and emergency settings were marginal, except for emergency department presentations in 2008, but increases in specific health categories were observed. Renal morbidity in the elderly was increased during both heatwaves. During the 2009 heatwave, direct heat-related admissions increased up to 14-fold compared to a three-fold increase seen during the 2008 event and during previous heatwaves. In 2009, marked increases in ischaemic heart disease were seen in the 15-64 year age group. Only the 2009 heatwave was associated with considerable increases in total mortality that particularly affected the 15-64 year age group (1.37; 95% CI, 1.09, 1.71), while older age groups were unaffected. Significant dose-response relationships were observed for heatwave duration (ambulance, hospital and emergency setting) and intensity (ambulance and mortality). CONCLUSIONS: While only incremental increases in morbidity and mortality above previous findings occurred in 2008, health impacts of the 2009 heatwave stand out. These findings send a signal that the intense and long 2009 heatwave may have exceeded the capacity of the population to cope. It is important that risk factors contributing to the adverse health outcomes are investigated to further improve preventive strategies.Monika Nitschke, Graeme R. Tucker, Alana L. Hansen, Susan Williams, Ying Zhang and Peng B

    Socio-economic status, racial composition and the affordability of fresh fruits and vegetables in neighborhoods of a large rural region in Texas

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    <p>Abstract</p> <p>Background</p> <p>Little is known about how affordability of healthy food varies with community characteristics in rural settings. We examined how the cost of fresh fruit and vegetables varies with the economic and demographic characteristics in six rural counties of Texas.</p> <p>Methods</p> <p>Ground-truthed data from the Brazos Valley Food Environment Project were used to identify all food stores in the rural region and the availability and lowest price of fresh whole fruit and vegetables in the food stores. Socioeconomic characteristics were extracted from the 2000 U.S. Census Summary Files 3 at the level of the census block group. We used an imputation strategy to calculate two types of price indices for both fresh fruit and fresh vegetables: a <it>high variety </it>and a <it>basic </it>index; and evaluated the relationship between neighborhood economic and demographic characteristics and affordability of fresh produce, using linear regression models.</p> <p>Results</p> <p>The mean cost of meeting the USDA recommendation of fruit consumption from a high variety basket of fruit types in our sample of stores was just over 27.50perweek.Relyingonthethreemostcommonfruitsloweredtheweeklyexpensetounder27.50 per week. Relying on the three most common fruits lowered the weekly expense to under 17.25 per week, a reduction of 37.6%. The effect of moving from a high variety to a low variety basket was much less when considering vegetable consumption: a 4.3% decline from 29.23to29.23 to 27.97 per week. Univariate regression analysis revealed that the cost of fresh produce is not associated with the racial/ethnic composition of the local community. However, multivariate regression showed that holding median income constant, stores in neighborhoods with higher percentages of Black residents paid more for fresh fruits and vegetables. The proportion of Hispanic residents was not associated with cost in either the univariate or multivariate analysis.</p> <p>Conclusion</p> <p>This study extends prior work by examining the affordability of fresh fruit and vegetables from food stores in a large rural area; and how access to an affordable supply of fresh fruit and vegetables differs by neighborhood inequalities. The approach and findings of this study are relevant and have important research and policy implications for understanding access and availability of affordable, healthy foods.</p
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