RESUMEN
14C is an important consideration within safety assessments for proposed geological disposal facilities for radioactive wastes, since it is capable of re-entering the biosphere through the generation of 14C bearing gases. The irradiation of graphite moderators in the UK gas-cooled nuclear power stations has led to the generation of a significant volume of 14C-containing intermediate level wastes. Some of this 14C is present as a carbonaceous deposit on channel wall surfaces. Within this study, the potential of biofilm growth upon irradiated and 13C doped graphite at alkaline pH was investigated. Complex biofilms were established on both active and simulant samples. High throughput sequencing showed the biofilms to be dominated by Alcaligenes sp at pH 9.5 and Dietzia sp at pH 11.0. Surface characterisation revealed that the biofilms were limited to growth upon the graphite surface with no penetration of the deeper porosity. Biofilm formation resulted in the generation of a low porosity surface layer without the removal or modification of the surface deposits or the release of the associated 14C/13C. Our results indicated that biofilm formation upon irradiated graphite is likely to occur at the pH values studied, without any additional release of the associated 14C.
RESUMEN
Whole apples have not been previously implicated in outbreaks of foodborne bacterial illness. We investigated a nationwide listeriosis outbreak associated with caramel apples. We defined an outbreak-associated case as an infection with one or both of two outbreak strains of Listeria monocytogenes highly related by whole-genome multilocus sequence typing (wgMLST) from 1 October 2014 to 1 February 2015. Single-interviewer open-ended interviews identified the source. Outbreak-associated cases were compared with non-outbreak-associated cases and traceback and environmental investigations were performed. We identified 35 outbreak-associated cases in 12 states; 34 (97%) were hospitalized and seven (20%) died. Outbreak-associated ill persons were more likely to have eaten commercially produced, prepackaged caramel apples (odds ratio 326·7, 95% confidence interval 32·2-3314). Environmental samples from the grower's packing facility and distribution-chain whole apples yielded isolates highly related to outbreak isolates by wgMLST. This outbreak highlights the importance of minimizing produce contamination with L. monocytogenes. Investigators should perform single-interviewer open-ended interviews when a food is not readily identified.
Asunto(s)
Brotes de Enfermedades , Enfermedades Transmitidas por los Alimentos/epidemiología , Listeria monocytogenes/aislamiento & purificación , Listeriosis/epidemiología , Malus/microbiología , Dulces/microbiología , Carbohidratos , Enfermedades Transmitidas por los Alimentos/microbiología , Genotipo , Entrevistas como Asunto , Listeria monocytogenes/clasificación , Listeria monocytogenes/genética , Listeriosis/microbiología , Tipificación de Secuencias Multilocus , Análisis de Supervivencia , Estados Unidos/epidemiologíaRESUMEN
The survival of microorganisms within a cementitious geological disposal facility for radioactive wastes heavily depends on their ability to survive the calcium-dominated, hyperalkaline conditions resulting from the dissolution of the cementitious materials. The results from this study show that the formation of flocs, composed of a complex mixture of extracellular polymeric substances (EPS), provides protection against alkaline pH values up to 13.0. The flocs were dominated by Alishewanella and Dietzia spp., producing a mannose-rich carbohydrate fraction incorporating extracellular DNA, resulting in Ca2+ sequestration. EPS provided a â¼10-µm thick layer around the cells within the center of the flocs, which were capable of growth at pH values of 11.0 and 11.5, maintaining internal pH values of 10.4 and 10.7, respectively. Microorganisms survived at a pH of 12.0, where an internal floc pH of 11.6 was observed, as was a reduced associated biomass. We observed limited floc survival (<2 weeks) at a pH of 13.0. This study demonstrates that flocs maintain lower internal pHs in response to the hyperalkaline conditions expected to occur within a cementitious geological disposal facility for radioactive wastes and indicates that floc communities within such a facility can survive at pHs up to 12.0.IMPORTANCE The role of extracellular polymeric substances (EPS) in the survival of microorganisms in hyperalkaline conditions is poorly understood. Here, we present the taxonomy, morphology, and chemical characteristics of an EPS-based microbial floc, formed by a consortium isolated from an anthropogenic hyperalkaline site. Short-term (<2 weeks) survival of the flocs at a pH of 13 was observed, with indefinite survival observed at a pH of 12.0. Measurements from micro-pH electrodes (10-µm-diameter tip) demonstrated that flocs maintain lower internal pHs in response to hyperalkaline conditions (pH 11.0, 11.5, and 12.0), demonstrating that floc formation and EPS production are survival strategies under hyperalkaline conditions. The results indicate how microbial communities may survive and propagate within the hyperalkaline environment that is expected to prevail in a cementitious geological disposal facility for radioactive wastes; the results are also relevant to the wider extremophile community.
Asunto(s)
Actinobacteria/metabolismo , Alteromonadaceae/metabolismo , Biopelículas/crecimiento & desarrollo , Residuos Radiactivos , Aguas del Alcantarillado/química , Actinobacteria/aislamiento & purificación , Alteromonadaceae/aislamiento & purificación , Concentración de Iones de Hidrógeno , Polímeros/metabolismo , Eliminación de Residuos LíquidosRESUMEN
November 11, 2016/65(44);1234-1237. What is already known about this topic? Candida auris is an emerging pathogenic fungus that has been reported from at least a dozen countries on four continents during 2009-2015. The organism is difficult to identify using traditional biochemical methods, some isolates have been found to be resistant to all three major classes of antifungal medications, and C. auris has caused health care-associated outbreaks. What is added by this report? This is the first description of C. auris cases in the United States. C. auris appears to have emerged in the United States only in the last few years, and U.S. isolates are related to isolates from South America and South Asia. Evidence from U.S. case investigations suggests likely transmission of the organism occurred in health care settings. What are the implications for public health practice? It is important that U.S. laboratories accurately identify C. auris and for health care facilities to implement recommended infection control practices to prevent the spread of C. auris. Local and state health departments and CDC should be notified of possible cases of C. auris and of isolates of C. haemulonii and Candida spp. that cannot be identified after routine testing.
Asunto(s)
Candida/aislamiento & purificación , Candidiasis/diagnóstico , Candidiasis/microbiología , Farmacorresistencia Fúngica Múltiple , Antifúngicos/uso terapéutico , Candida/efectos de los fármacos , Candidiasis/tratamiento farmacológico , Enfermedades Transmisibles Emergentes , Salud Global , Humanos , Pronóstico , Factores de Riesgo , Factores de Tiempo , Estados UnidosRESUMEN
We report on a case of listeriosis in a patient who probably consumed a prepackaged romaine lettuce-containing product recalled for Listeria monocytogenes contamination. Although definitive epidemiological information demonstrating exposure to the specific recalled product was lacking, the patient reported consumption of a prepackaged romaine lettuce-containing product of either the recalled brand or a different brand. A multinational investigation found that patient and food isolates from the recalled product were indistinguishable by pulsed-field gel electrophoresis and were highly related by whole genome sequencing, differing by four alleles by whole genome multilocus sequence typing and by five high-quality single nucleotide polymorphisms, suggesting a common source. To our knowledge, this is the first time prepackaged lettuce has been identified as a likely source for listeriosis. This investigation highlights the power of whole genome sequencing, as well as the continued need for timely and thorough epidemiological exposure data to identify sources of foodborne infections.
Asunto(s)
Enfermedades Transmitidas por los Alimentos , Lactuca , Electroforesis en Gel de Campo Pulsado , Microbiología de Alimentos , Humanos , Listeria monocytogenes/genética , ListeriosisRESUMEN
BACKGROUND: High levels of sedentary behaviour (i.e., sitting) are a risk factor for poor health. With high levels of sitting widespread in desk-based office workers, office workplaces are an appropriate setting for interventions aimed at reducing sedentary behaviour. This paper describes the development processes and proposed intervention procedures of Stand More AT (SMArT) Work, a multi-component randomised control (RCT) trial which aims to reduce occupational sitting time in desk-based office workers within the National Health Service (NHS). METHODS/DESIGN: SMArT Work consists of 2 phases: 1) intervention development: The development of the SMArT Work intervention takes a community-based participatory research approach using the Behaviour Change Wheel. Focus groups will collect detailed information to gain a better understanding of the most appropriate strategies, to sit alongside the provision of height-adjustable workstations, at the environmental, organisational and individual level that support less occupational sitting. 2) intervention delivery and evaluation: The 12 month cluster RCT aims to reduce workplace sitting in the University Hospitals of Leicester NHS Trust. Desk-based office workers (n = 238) will be randomised to control or intervention clusters, with the intervention group receiving height-adjustable workstations and supporting techniques based on the feedback received from the development phase. Data will be collected at four time points; baseline, 3, 6 and 12 months. The primary outcome is a reduction in sitting time, measured by the activPAL(TM) micro at 12 months. Secondary outcomes include objectively measured physical activity and a variety of work-related health and psycho-social measures. A process evaluation will also take place. DISCUSSION: This study will be the first long-term, evidence-based, multi-component cluster RCT aimed at reducing occupational sitting within the NHS. This study will help form a better understanding and knowledge base of facilitators and barriers to creating a healthier work environment and contribute to health and wellbeing policy. TRIAL REGISTRATION: ISRCTN10967042 . Registered 2 February 2015.
Asunto(s)
Planificación Ambiental , Conductas Relacionadas con la Salud , Postura , Conducta Sedentaria , Trabajo , Investigación Participativa Basada en la Comunidad , Computadores , Empleo , Grupos Focales , Humanos , Proyectos de Investigación , Medicina Estatal , Lugar de TrabajoRESUMEN
In June 2011, a cluster of suspected cases of Guillain-Barré syndrome (GBS), which can follow Campylobacter jejuni infection, was identified in San Luis Río Colorado (SLRC), Sonora, Mexico and Yuma County, Arizona, USA. An outbreak investigation identified 26 patients (18 from Sonora, eight from Arizona) with onset of GBS 4 May-21 July 2011, exceeding the expected number of cases (n = 1-2). Twenty-one (81%) patients reported antecedent diarrhoea, and 61% of 18 patients tested were seropositive for C. jejuni IgM antibodies. In a case-control study matched on age group, sex, ethnicity, and neighbourhood of residence, all Arizona GBS patients travelled to SLRC during the exposure period vs. 45% of matched controls (matched odds ratio 8·1, 95% confidence interval 1·5-∞). Exposure information and an environmental assessment suggested that GBS cases resulted from a large outbreak of C. jejuni infection from inadequately disinfected tap water in SLRC. Binational collaboration was essential in investigating this cross-border GBS outbreak, the first in mainland North America since 1976.
Asunto(s)
Infecciones por Campylobacter/complicaciones , Infecciones por Campylobacter/epidemiología , Campylobacter jejuni/aislamiento & purificación , Brotes de Enfermedades , Síndrome de Guillain-Barré/epidemiología , Síndrome de Guillain-Barré/microbiología , Anticuerpos Antibacterianos/sangre , Arizona/epidemiología , Infecciones por Campylobacter/transmisión , Estudios de Casos y Controles , Microbiología de Alimentos , Humanos , México/epidemiología , Vigilancia en Salud Pública , Estudios Retrospectivos , Microbiología del AguaRESUMEN
UNLABELLED: Both NICE and RCOG recommend 30min of moderate physical activity, at least four times per week, for women with uncomplicated pregnancies, in all trimesters. The primary aims of this study were to establish the views of UK women regarding how much exercise they should undertake at each stage of pregnancy and whether they accumulated the recommended amount of physical activity through exercise during their current or most recent pregnancy. METHODS: An online survey was developed and advertised to women who had been or were pregnant via social media and websites related to pregnancy or parenting. Exercise was defined within the survey as including jogging, cycling, exercise classes and brisk but not gentle walking. RESULTS: 1001 women participated. 22.9% were currently pregnant, and 64.8% had been pregnant in the last three years. 38.5% of participants reported that women should exercise four or more times per week in the first trimester, and 23% in the third trimester. 21.3% reported exercising four or more times per week in their first trimester, and 11.4% in the third trimester. 46.9% reduced their exercise upon becoming pregnant, while 6.7% increased exercise and 12% stopped completely. Tiredness (62.7%), aches and pains (44.8%), morning sickness (41.4%) and worry about miscarriage (27.4%) were the most common reasons to avoid exercise. CONCLUSIONS: UK women may be unaware of the recommended levels of physical activity in pregnancy and may fail to meet recommendations through exercise. Despite no evidence of risk, women are concerned that exercise contributes to miscarriage.
RESUMEN
BACKGROUND: The risk of viral infection associated with blood transfusion is lower than ever before because of aggressive screening and testing practices. NAT technology has lowered that risk even further but at an additional cost to the health-care system. STUDY DESIGN AND METHODS: Marginal cost-effectiveness of NAT for HIV, HCV, and HBV in whole-blood donations was calculated with a previously published Markov decision model. This model was updated with disease incidence data from all 2001 American Red Cross whole-blood donations as well as window-period data from the Retrovirus Epidemiology Donor Study (REDS). RESULTS: Whole-blood donation NAT for HIV and HCV is expected to cost between 155 US dollars million (minipool NAT) and 428 million US dollars(single-donation NAT) per year in the US and avert 4 to 7 HIV infections and 56 to 59 HCV infections. Adding HBV NAT would be expected to avert 9 to 37 HBV infections at an additional cost of between 39 million US dollars and 130 million US dollars per year. Overall, NAT would cost between 4.7 million US dollars and 11.2 million US dollars per quality-adjusted life-year saved. Discontinuing HIV p24 antigen and HBc testing would offset this somewhat. CONCLUSIONS: The cost-effectiveness of whole-blood NAT is poor. The testing cost would need to decrease significantly to bring the cost-effectiveness in line with most other accepted medical practices.
Asunto(s)
Donantes de Sangre , VIH/aislamiento & purificación , Hepacivirus/aislamiento & purificación , Virus de la Hepatitis B/aislamiento & purificación , ARN Viral/sangre , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/economía , Análisis Costo-Beneficio , VIH/genética , Infecciones por VIH/transmisión , Hepacivirus/genética , Hepatitis B/transmisión , Virus de la Hepatitis B/genética , Hepatitis C/transmisión , Humanos , Reacción a la TransfusiónRESUMEN
BACKGROUND: The return of joint drainage after hip and knee arthroplasty is a widely used but expensive blood-conservation technique. STUDY DESIGN AND METHODS: A Markov decision analysis model was used to evaluate the cost-effectiveness of postoperative RBC recovery in preventing viral complications of allogeneic transfusion. RESULTS: In the baseline analysis, using an RBC-recovery device saves 5 quality-adjusted minutes of longevity at an average incremental cost of $53. This corresponds to $5.7 million per quality-adjusted life year. This figure was most sensitive to the direct cost differences of allogeneic versus recovered RBCs and to the volume of RBCs recovered per device. Such devices would save health care resources if they cost less than $73 or if they were applied only in cases where joint drainage was between 600 and 1100 mL. CONCLUSION: For most clinical situations, postarthroplasty RBC recovery does not appear to be as cost-effective as most other medical interventions. Clinical attention should be directed toward developing protocols for the preferential use of postoperative RBC-recovery devices in situations where they provide the greatest benefit.
Asunto(s)
Artroplastia de Reemplazo de Cadera/efectos adversos , Artroplastia de Reemplazo de Rodilla/efectos adversos , Eritrocitos/fisiología , Infecciones por VIH/prevención & control , Infecciones por VIH/transmisión , Cuidados Posoperatorios/economía , Reacción a la Transfusión , Análisis Costo-Beneficio , Calidad de Vida , Recuperación de la Función/fisiología , Factores de TiempoRESUMEN
Enantiomeric resolution of butibufen has been achieved on a cellulose tris(3,5-dimethylphenylcarbamate) chiral stationary phase with hexane-isopropanol-trifluoroacetic acid, 100:1.2:0.02 (v/v/v) as mobile phase at a flow rate of 1.0 mL min(-1). Semi-preparative isolation of the enantiomers then chiroptical characterization indicated that the order of elution was (-)-R- before (+)-S-butibufen. When tested for their effects on the cyclooxygenase and 5-lipoxygenase pathways of eicosanoid metabolism in calcium ionophore-activated rat peritoneal leukocytes it was found that (+)-S-butibufen inhibited generation of thromboxane B2 (TXB2) and prostaglandin E2 (PGE2) (cyclooxygenase pathway), with an IC50 of 1.5 microM (approx.), whereas the (-)-R enantiomer was essentially inactive. Neither enantiomer inhibited the 5-lipoxygenase pathway. In this regard, (+)-S-butibufen was approximately five times less potent as a cyclooxygenase inhibitor than (+)-S-ibuprofen. These results show the enantiomeric specificity and pathway selectivity of this novel non-steroidal anti-inflammatory drug.
Asunto(s)
Ibuprofeno/farmacología , Fenilbutiratos/farmacología , Animales , Antiinflamatorios no Esteroideos/química , Antiinflamatorios no Esteroideos/aislamiento & purificación , Antiinflamatorios no Esteroideos/farmacología , Araquidonato 5-Lipooxigenasa/efectos de los fármacos , Araquidonato 5-Lipooxigenasa/metabolismo , Ácidos Araquidónicos/metabolismo , Líquido Ascítico/citología , Cromatografía Líquida de Alta Presión , Dicroismo Circular , Inhibidores de la Ciclooxigenasa/farmacología , Eicosanoides/metabolismo , Inhibidores Enzimáticos/farmacología , Ibuprofeno/química , Ibuprofeno/aislamiento & purificación , Leucocitos/efectos de los fármacos , Leucocitos/enzimología , Leucocitos/metabolismo , Masculino , Fenilbutiratos/química , Fenilbutiratos/aislamiento & purificación , Prostaglandina-Endoperóxido Sintasas/efectos de los fármacos , Prostaglandina-Endoperóxido Sintasas/metabolismo , Ratas , Ratas Wistar , EstereoisomerismoRESUMEN
Manual review of antibiotic sensitivity testing results is an essential component of a microbiology laboratory's quality control process. Such review is tedious and prone to human error, however. An expert system is described that remembers which susceptibility patterns are considered typical or atypical by expert reviewers, then uses these to prescreen future isolates. It uses a similarity function to allow matching against this library when two patterns are close, but not identical. Use of this system allows more efficient and reliable review of the laboratory's antibiotic sensitivity testing results.
Asunto(s)
Sistemas de Apoyo a Decisiones Clínicas , Sistemas Especialistas , Pruebas de Sensibilidad Microbiana/normas , Estudios de Evaluación como Asunto , Humanos , Laboratorios/normas , Microbiología/normas , Control de Calidad , Reproducibilidad de los ResultadosRESUMEN
Peak flow meters provide physicians and patients with objective measures about changes in pulmonary obstruction. We evaluated eight models of peak flowmeters and measured their accuracy and reproducibility with methods recently recommended by the National Asthma Education Program (NAEP). Waveforms from the American Thoracic Society's spirometer testing set were used to drive a computer-controlled syringe. Testing was done at Salt Lake City at an altitude 1,400 m. It appears that the original Wright peak flowmeter has been used as the "de facto" standard. We found that the original Wright peak flowmeter overestimated flows in its midrange; and, as a consequence, most of the other peak flowmeters also overestimated peak flows. The overestimation of peak flows may have been understated because of the 1,400-m altitude testing site. To the credit of the instrument manufacturers, we were pleasantly surprised with the quality, accuracy, and reproducibility of presently available peak flowmeters; however, as a result of our testing, we suspect that with little effort, manufacturers of peak flowmeters could improve the accuracy of their devices. Standardized testing methods and equipment should make the task of peak flowmeter design, manufacture, and testing even easier. We trust that manufacturers of peak flowmeters will respond appropriately and improve their instruments.
Asunto(s)
Altitud , Ápice del Flujo Espiratorio , Reología , Adulto , Niño , Estudios de Evaluación como Asunto , Humanos , Reproducibilidad de los Resultados , Espirometría/instrumentaciónRESUMEN
Eye injuries have occurred to squash players wearing commercial open-type eyeguards, suggesting inadequacies in their design. This study reports experimental observations on the deformation of high velocity squash balls at an aperture simulating an open-type of eyeguard. Open eyeguards were shown to be inadequate in preventing eye trauma by ball-strike. Recommendations for improvement of eyeguard design have been made.
Asunto(s)
Traumatismos en Atletas/prevención & control , Lesiones Oculares/prevención & control , Dispositivos de Protección de los Ojos , Equipos de Seguridad , Traumatismos en Atletas/fisiopatología , Fenómenos Biofísicos , Biofisica , Diseño de Equipo , Lesiones Oculares/fisiopatología , HumanosRESUMEN
The most common cause of colonic obstruction is adenocarcinoma, followed by diverticulitis, volvulus, and a variety of miscellaneous causes. Most signs and symptoms, from whatever cause, consist of abdominal pain with distention and the inability to pass flatus or stool. The clinical diagnosis is confirmed by x-ray studies. Plain films of the abdomen in various positions, chest films, and the addition of contrast studies verify the cause of the obstruction in most instances. The differentiation between neoplasm and diverticulitis causing the obstruction can be difficult or impossible at times, and may become apparent only after the obstruction begins to resolve with conservative management, or the cause is discovered at surgery. The history of previous abdominal or pelvic irradiation, surgery, and inflammatory bowel disease often causes difficulty in the differential diagnosis.
Asunto(s)
Enfermedades del Colon/diagnóstico , Obstrucción Intestinal/diagnóstico , Adenocarcinoma/complicaciones , Enfermedades del Colon/diagnóstico por imagen , Enfermedades del Colon/etiología , Neoplasias del Colon/complicaciones , Colonoscopía , Diagnóstico Diferencial , Diverticulitis del Colon/complicaciones , Humanos , Obstrucción Intestinal/diagnóstico por imagen , Obstrucción Intestinal/etiología , Examen Físico , RadiografíaRESUMEN
A technique is described for the use of iridium-192 implants, combined with external irradiation, in the treatment of primary anorectal malignancy. The method allows large doses of radiation to the primary growth, regional infiltration and extensions, with much lower doses to the surrounding normal tissues and organs. Acceptable criteria for conservative local treatment of selected primary anorectal carcinomas are established. For the poor risk patient, the patient who refuses operation, and those having primary or recurrent carcinoma with distant metastases, this method of treatment offers maximum benefit, palliation, and acceptable complication rates. With judicious selection of patients and careful attention to volume of tissue treated, total dose, and fractionalization, serious complications should be substantially reduced.
Asunto(s)
Neoplasias del Ano/radioterapia , Braquiterapia , Iridio/uso terapéutico , Radioisótopos , Neoplasias del Recto/radioterapia , Anciano , Braquiterapia/efectos adversos , Diarrea/etiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Necrosis/etiología , Radioisótopos/uso terapéuticoRESUMEN
Ten patients with carcinoma of the anorectum were treated with a combination of external irradiation and after-loading interstitial 192Ir implant, which seems to be effective in controlling relatively small cancers of the anorectum and providing effective palliation of extensive lesions. Five of the 10 patients remain free of tumor after a minimum follow-up of 15 months. Four of the 10 were treated with one interstitial implant and 4,000--5,000 rads of external irradiation and 6 were treated with the same amount of irradiation and two implants. When two implants were used, complications were minimal.