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2.
Clin Oncol (R Coll Radiol) ; 36(5): 300-306, 2024 05.
Artículo en Inglés | MEDLINE | ID: mdl-38388251

RESUMEN

AIMS: Squamous cell carcinoma oral cavity cancers (SCCOCCs) have a higher reported incidence in South Asian countries. We sought to compare presenting stage and outcome by ethnicity in patients with SCCOCC treated with radical radiotherapy in a single centre in the UK. MATERIALS AND METHODS: All patients with SCCOCC treated with radical radiotherapy at an oncology department in Leicester (UK) between 2011 and 2017 were identified. Baseline demographic, clinical data and 2-year treatment outcomes were reported. RESULTS: Of the 109 patients included, 40 were South Asian and 59 were non-South Asian. South Asians had significantly poorer 2-year disease-free survival compared with non-South Asians (54.6% versus 73%, P = 0.01). CONCLUSION: Our analysis suggests that South Asians with SCCOCC have poorer outcomes despite a younger age and similar disease characteristics. Environmental, social factors and differing biology of disease may be responsible and further research is required to inform targeted interventions.


Asunto(s)
Pueblo Asiatico , Neoplasias de la Boca , Humanos , Etnicidad , Resultado del Tratamiento , Neoplasias de la Boca/etnología , Reino Unido
4.
Anaesth Rep ; 9(1): 106-109, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34027412

RESUMEN

There has been a resurgence in the illicit use of 2,4-dinitrophenol by people wishing to achieve rapid weight loss. Despite its availability, the drug is banned for human consumption as it is toxic and can have fatal consequences. We present the case of a 23-year-old man who regularly consumed 2,4-dinitrophenol to generate fat loss without apparent ill effect. He was involved in a high-speed road traffic collision and sustained limb-threatening injuries. The combination of emergency surgery, trauma and 2,4-dinitrophenol consumption culminated in deterioration under anaesthesia, with subsequent death from multiorgan failure in the intensive care unit 48 h later. Previous cases have reported death from 2,4-dinitrophenol toxicity alone. We believe this is the first reported case of 2,4-dinitrophenol toxicity triggered by the additional physiological stress of polytrauma and emergency surgery.

5.
BMC Health Serv Res ; 20(1): 814, 2020 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-32867837

RESUMEN

BACKGROUND: Many women with hyperglycaemia in pregnancy do not receive care during and after pregnancy according to standards recommended in international guidelines. The burden of hyperglycaemia in pregnancy falls disproportionately upon Indigenous peoples worldwide, including Aboriginal and Torres Strait Islander women in Australia. The remote and regional Australian context poses additional barriers to delivering healthcare, including high staff turnover and a socially disadvantaged population with a high prevalence of diabetes. METHODS: A complex health systems intervention to improve care for women during and after a pregnancy complicated by hyperglycaemia will be implemented in remote and regional Australia (the Northern Territory and Far North Queensland). The Theoretical Domains Framework was used during formative work with stakeholders to identify intervention components: (1) increasing workforce capacity, skills and knowledge and improving health literacy of health professionals and women; (2) improving access to healthcare through culturally and clinically appropriate pathways; (3) improving information management and communication; (4) enhancing policies and guidelines; (5) embedding use of a clinical register as a quality improvement tool. The intervention will be evaluated utilising the RE-AIM framework at two timepoints: firstly, a qualitative interim evaluation involving interviews with stakeholders (health professionals, champions and project implementers); and subsequently a mixed-methods final evaluation of outcomes and processes: interviews with stakeholders; survey of health professionals; an audit of electronic health records and clinical register; and a review of operational documents. Outcome measures include changes between pre- and post-intervention in: proportion of high risk women receiving recommended glucose screening in early pregnancy; diabetes-related birth outcomes; proportion of women receiving recommended postpartum care including glucose testing; health practitioner confidence in providing care, knowledge and use of relevant guidelines and referral pathways, and perception of care coordination and communication systems; changes to health systems including referral pathways and clinical guidelines. DISCUSSION: This study will provide insights into the impact of health systems changes in improving care for women with hyperglycaemia during and after pregnancy in a challenging setting. It will also provide detailed information on process measures in the implementation of such health system changes.


Asunto(s)
Servicios de Salud del Indígena/organización & administración , Hiperglucemia/terapia , Complicaciones del Embarazo/terapia , Atención Prenatal/organización & administración , Adulto , Femenino , Programas de Gobierno , Personal de Salud , Humanos , Hiperglucemia/diagnóstico , Tamizaje Masivo , Servicios de Salud Materna , Asistencia Médica , Nativos de Hawái y Otras Islas del Pacífico , Northern Territory , Embarazo , Embarazo en Diabéticas/diagnóstico , Embarazo en Diabéticas/epidemiología , Mejoramiento de la Calidad , Queensland , Derivación y Consulta
6.
Obes Rev ; 19(4): 529-537, 2018 04.
Artículo en Inglés | MEDLINE | ID: mdl-29266740

RESUMEN

The effectiveness of bariatric surgery has been well-studied. However, complications after bariatric surgery have been understudied. This review assesses <30-d major complications associated with bariatric procedures, including anastomotic leak, myocardial infarction and pulmonary embolism. This review included 71 studies conducted in the USA between 2003 and 2014 and 107,874 patients undergoing either gastric bypass, adjustable gastric banding or sleeve gastrectomy, with mean age of 44 years and pre-surgery body mass index of 46.5 kg m-2 . Less than 30-d anastomotic leak rate was 1.15%; myocardial infarction rate was 0.37%; pulmonary embolism rate was 1.17%. Among all patients, mortality rate following anastomotic leak, myocardial infarction and pulmonary embolism was 0.12%, 0.37% and 0.18%, respectively. Among surgical procedures, <30-d after surgery, sleeve gastrectomy (1.21% [95% confidence interval, 0.23-2.19%]) had higher anastomotic leak rate than gastric bypass (1.14% [95% confidence interval, 0.84-1.43%]); gastric bypass had higher rates of myocardial infarction and pulmonary embolism than adjustable gastric banding or sleeve gastrectomy. During the review, we found that the quality of complication reporting is lower than the reporting of other outcomes. In summary, <30-d rates of the three major complications after either one of the procedures range from 0% to 1.55%. Mortality following these complications ranges from 0% to 0.64%. Future studies reporting complications after bariatric surgery should improve their reporting quality.


Asunto(s)
Fuga Anastomótica/etiología , Cirugía Bariátrica/efectos adversos , Infarto del Miocardio/etiología , Obesidad Mórbida/cirugía , Complicaciones Posoperatorias , Embolia Pulmonar/etiología , Fuga Anastomótica/mortalidad , Cirugía Bariátrica/mortalidad , Humanos , Infarto del Miocardio/mortalidad , Complicaciones Posoperatorias/mortalidad , Embolia Pulmonar/mortalidad , Resultado del Tratamiento , Estados Unidos/epidemiología
7.
Clin Exp Dermatol ; 39(8): 894-9, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25196833

RESUMEN

BACKGROUND: Dupuytren contracture (DC) is a fibrocontractile disease of the palms, affecting approximately 4% of the population, while psoriasis is an immune-mediated disease, affecting 2% of the population. Through clinical observation in our psoriasis clinic, we found an apparent increased prevalence of DC in patients with psoriasis compared with the general population. This has not previously been statistically verified in a clinical study. AIM: To evaluate the prevalence of DC in the full range of clinical psoriasis phenotypes. METHODS: In total, 98 patients with psoriasis attending our psoriasis clinic were examined for DC, based on predetermined criteria. In addition, 84 patients with DC, obtained from a specialist hand clinic, were assessed using a validated psoriasis questionnaire. We utilized Bayes theorem and bootstrap simulation to calculate the conditional prevalence of DC, then we used the results to compare the prevalence of DC between patients with psoriasis and a nonpsoriasis population. RESULTS: The percentage of patients with DC was 19.6% in the psoriasis population and 3.6% in the nonpsoriasis population. Development of DC showed a phenotypic predilection, with 39.1% of patients with predominantly palmoplantar involvement and 38.9% of patients with intertriginous psoriasis developing DC compared with 12.7% of patients with psoriasis who did not have these two phenotypical presentations. CONCLUSIONS: Our data show a positive correlation between psoriasis and DC. Patients with the palmoplantar phenotype of psoriasis were more likely to develop DC. By understanding this relationship, dermatologists may diagnose DC early in its onset in patients with psoriasis, prompting referral to hand surgeons when appropriate.


Asunto(s)
Contractura de Dupuytren/epidemiología , Psoriasis/epidemiología , Adulto , Anciano , Teorema de Bayes , Estudios de Cohortes , Femenino , Humanos , Masculino , Persona de Mediana Edad , Prevalencia , Distribución por Sexo , Estados Unidos/epidemiología
8.
J Expo Anal Environ Epidemiol ; 13(6): 417-26, 2003 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-14603342

RESUMEN

Classification and regression tree methods represent a potentially powerful means of identifying patterns in exposure data that may otherwise be overlooked. Here, regression tree models are developed to identify associations between blood concentrations of benzene and lead and over 300 variables of disparate type (numerical and categorical), often with observations that are missing or below the quantitation limit. Benzene and lead are selected from among all the environmental agents measured in the NHEXAS Region V study because they are ubiquitous, and they serve as paradigms for volatile organic compounds (VOCs) and heavy metals, two classes of environmental agents that have very different properties. Two sets of regression models were developed. In the first set, only environmental and dietary measurements were employed as predictor variables, while in the second set these were supplemented with demographic and time-activity data. In both sets of regression models, the predictor variables were regressed on the blood concentrations of the environmental agents. Jack-knife cross-validation was employed to detect overfitting of the models to the data. Blood concentrations of benzene were found to be associated with: (a) indoor air concentrations of benzene; (b) the duration of time spent indoors with someone who was smoking; and (c) the number of cigarettes smoked by the subject. All these associations suggest that tobacco smoke is a major source of exposure to benzene. Blood concentrations of lead were found to be associated with: (a) house dust concentrations of lead; (b) the duration of time spent working in a closed workshop; and (c) the year in which the subject moved into the residence. An unexpected finding was that the regression trees identified time-activity data as better predictors of the blood concentrations than the measurements in environmental and dietary media.


Asunto(s)
Actividades Cotidianas , Benceno/análisis , Biomarcadores/análisis , Exposición a Riesgos Ambientales , Contaminantes Ambientales/análisis , Plomo/análisis , Modelos Estadísticos , Adolescente , Adulto , Anciano , Niño , Preescolar , Recolección de Datos , Demografía , Dieta , Polvo , Femenino , Vivienda , Humanos , Lactante , Recién Nacido , Plomo/sangre , Masculino , Persona de Mediana Edad , Análisis de Regresión , Factores de Tiempo , Volatilización
9.
Apoptosis ; 8(2): 179-90, 2003 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-12766478

RESUMEN

Apoptosis, or programmed cell death, is a well-ordered process that allows damaged or diseased cells to be removed from an organism without severe inflammatory reactions. Multiple factors, including microbial infection, can induce programmed death and trigger reactions in both host and microbial cellular pathways. Whereas an ultimate outcome is host cell death, these apoptotic triggering mechanisms may also facilitate microbial spread and prolong infection. To gain a better understanding of the complex events of host cell response to microbial infection, we investigated the molecular role of the microorganism Enteropathogenic Escherichia coli (EPEC) in programmed cell death. We report that wild type strain of EPEC, E2348/69, induced apoptosis in cultured PtK2 and Caco-2 cells, and in contrast, infections by the intracellularly localized Listeria monocytogenes did not. Fractionation and concentration of EPEC-secreted proteins demonstrated that soluble protein factors expressed by the bacteria were capable of inducing the apoptotic events in the absence of organism attachment, suggesting adherence is not required to induce host cell death. Among the known EPEC proteins secreted via the Type III secretion (TTS) system, we identified the translocated intimin receptor (Tir) in the apoptosis-inducing protein sample. In addition, host cell ectopic expression of an EPEC GFP-Tir showed mitochondrial localization of the protein and produced apoptotic effects in transfected cells. Taken together, these results suggest a potential EPEC Tir-mediated role in the apoptotic signaling cascade of infected host cells.


Asunto(s)
Apoptosis , Proteínas de Escherichia coli/fisiología , Escherichia coli/patogenicidad , Receptores de Superficie Celular/fisiología , Actinas/metabolismo , Animales , Adhesión Bacteriana , División Celular , Línea Celular , Línea Celular Tumoral , Núcleo Celular/metabolismo , Citoesqueleto/metabolismo , Fragmentación del ADN , Escherichia coli/metabolismo , Proteínas Fluorescentes Verdes , Humanos , Listeria monocytogenes/metabolismo , Proteínas Luminiscentes/metabolismo , Microscopía Fluorescente , Mitocondrias/metabolismo , Modelos Biológicos , Factores de Tiempo
10.
Environ Health Perspect ; 109(6): 583-90, 2001 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-11445512

RESUMEN

The Minnesota Children's Pesticide Exposure Study is a probability-based sample of 102 children 3-13 years old who were monitored for commonly used pesticides. During the summer of 1997, first-morning-void urine samples (1-3 per child) were obtained for 88% of study children and analyzed for metabolites of insecticides and herbicides: carbamates and related compounds (1-NAP), atrazine (AM), malathion (MDA), and chlorpyrifos and related compounds (TCPy). TCPy was present in 93% of the samples, whereas 1-NAP, MDA, and AM were detected in 45%, 37%, and 2% of samples, respectively. Measured intrachild means ranged from 1.4 microg/L for MDA to 9.2 microg/L for TCPy, and there was considerable intrachild variability. For children providing three urine samples, geometric mean TCPy levels were greater than the detection limit in 98% of the samples, and nearly half the children had geometric mean 1-NAP and MDA levels greater than the detection limit. Interchild variability was significantly greater than intrachild variability for 1-NAP (p = 0.0037) and TCPy (p < 0.0001). The four metabolites measured were not correlated within urine samples, and children's metabolite levels did not vary systematically by sex, age, race, household income, or putative household pesticide use. On a log scale, mean TCPy levels were significantly higher in urban than in nonurban children (7.2 vs. 4.7 microg/L; p = 0.036). Weighted population mean concentrations were 3.9 [standard error (SE) = 0.7; 95% confidence interval (CI), 2.5, 5.3] microg/L for 1-NAP, 1.7 (SE = 0.3; 95% CI, 1.1, 2.3) microg/L for MDA, and 9.6 (SE = 0.9; 95% CI, 7.8, 11) microg/L for TCPy. The weighted population results estimate the overall mean and variability of metabolite levels for more than 84,000 children in the census tracts sampled. Levels of 1-NAP were lower than reported adult reference range concentrations, whereas TCPy concentrations were substantially higher. Concentrations of MDA were detected more frequently and found at higher levels in children than in a recent nonprobability-based sample of adults. Overall, Minnesota children's TCPy and MDA levels were higher than in recent population-based studies of adults in the United States, but the relative magnitude of intraindividual variability was similar for adults and children.


Asunto(s)
Protección a la Infancia , Plaguicidas/análisis , Adolescente , Biomarcadores/análisis , Niño , Preescolar , Estudios de Cohortes , Exposición a Riesgos Ambientales , Femenino , Humanos , Lactante , Masculino , Plaguicidas/efectos adversos , Plaguicidas/metabolismo , Reproducibilidad de los Resultados , Muestreo , Urinálisis
11.
J Expo Anal Environ Epidemiol ; 11(2): 79-85, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11409008

RESUMEN

The objective of this study was to compare the driving habits and vehicle maintenance patterns of individuals who report symptoms when exposed to methyl tertiary-butyl ether (MTBE) and those who are asymptomatic when exposed to the oxygenate. Participants were healthy volunteers (CON) and self-reported MTBE-sensitive individuals (SRS) who participated in a controlled exposure study of MTBE in gasoline. A questionnaire was developed to gather information about each participant's automobile usage, engine maintenance habits and fueling and driving patterns. Results showed that the individuals who had self-reported heightened sensitivity to the oxygenate drove their vehicles more often and fueled their vehicles more frequently than asymptomatic individuals. In addition, the self-reported symptomatic individuals in this study were shown to be more likely to drive vehicles with some form of body damage and carbureted engines.


Asunto(s)
Contaminantes Atmosféricos/análisis , Conducción de Automóvil , Exposición a Riesgos Ambientales , Éteres Metílicos/análisis , Emisiones de Vehículos/análisis , Actividades Cotidianas , Adulto , Recolección de Datos , Femenino , Humanos , Masculino , Persona de Mediana Edad
12.
Eur J Pediatr Surg ; 11(2): 86-91, 2001 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-11371042

RESUMEN

Periumbilical necrotizing fasciitis (PNF) in the newborn is an invasive bacterial infection of the abdominal wall with a fulminant course and a high mortality rate. Little is known about the etiology, risk factors and microbiology of the disease. 18 patients with periumbilical necrotizing fasciitis were included in this retrospective study and were compared with 50 patients with omphalitis over a 6-year period, between 1992 and 1998. This represents the largest reported study. The children with periumbilical necrotizing fasciitis presented at a younger age compared to the omphalitis group (8.4 days vs. 9.1 days) and had a shorter clinical history (1.9 days vs. 2.8 days), suggesting that PNF is not a mere sequela of omphalitis but has distinctive underlying causes. None of our patients in the omphalitis group had a progression of the disease towards necrotizing fasciitis. The microbial spectrum of cultures obtained in patients with PNF consisted of mixed anaerobes and aerobes in 55%, and mixed aerobes in 36% of cases. Early aggressive therapy, including elective endotracheal intubation, immediate surgical debridement of the abdominal wall, antibiotics and supportive measurements resulted in a survival rate of 56%. Far from being satisfactory, this is nevertheless higher than the 12.5% to 45% survival rate quoted in previous publications.


Asunto(s)
Fascitis Necrotizante , Ombligo/microbiología , Infecciones Bacterianas/complicaciones , Fascitis Necrotizante/microbiología , Fascitis Necrotizante/mortalidad , Fascitis Necrotizante/terapia , Femenino , Humanos , Recién Nacido , Inflamación/complicaciones , Masculino , Complicaciones Posoperatorias , Estudios Retrospectivos
13.
Arch Environ Health ; 56(2): 103-10, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11339672

RESUMEN

More than 100 academic and private-sector researchers, government officials, politicians, and public health practitioners met to discuss issues regarding children's environmental health. Of special concern were the lack of toxicological data on many chemicals, the paucity of studies of children's exposure to these chemicals, and our limited understanding of pediatric toxicology. The increased incidence of childhood cancers and asthma were also of concern, as was our lack of understanding of how exposures to multiple environmental chemicals in low doses may influence child growth and development, disrupt endocrine function, and stimulate development of chronic diseases. An agenda for basic research, education and outreach, and policy and program development was created, with a goal of moving children's environmental health issues forward in a logical and thoughtful manner.


Asunto(s)
Asma/epidemiología , Protección a la Infancia/tendencias , Salud Ambiental , Insecticidas/efectos adversos , Neoplasias/epidemiología , Bifenilos Policlorados/efectos adversos , Niño , Preescolar , Enfermedades del Sistema Endocrino/inducido químicamente , Humanos , Investigación , Estados Unidos/epidemiología
14.
Cardiovasc Res ; 49(3): 681-9, 2001 Feb 16.
Artículo en Inglés | MEDLINE | ID: mdl-11166281

RESUMEN

OBJECTIVE: Since the role of Ca2+ in angiogenesis is not fully understood, we investigated the effect of thapsigargin (TG: depletes intracellular Ca2+ pools) and other Ca2+ modulators [ionomycin, calcium ionophore A23187 and dibutyrylhydroquinone (DBHQ)] on in vitro angiogenesis by rat aortic rings. METHODS: Aortae from Sprague-Dawley rats were cut into 2-mm rings, embedded in a fibrin clot and cultured for 15 days in serum-free medium containing drugs and the microvessels counted. Rings were also pre-treated with TG and Ca2+ modulators for 1 h prior to embedding and culture. Viability was examined by the measurement of lactic acid dehydrogenase release. Rings were also treated with hydrocortisone and lavendustin A (a tyrosine kinase inhibitor), as positive controls. The effect of TG on the proliferation and migration of human umbilical artery endothelial cells (HUVECs) was studied in parallel. RESULTS: TG significantly inhibited microvessel formation and HUVEC proliferation and migration in a dose-dependent manner, all at <10 nmol/l, without affecting viability. In contrast, ionomycin, A23187 and DBHQ were cytotoxic at inhibitory concentrations. Continual exposure to hydrocortisone and lavendusin A also inhibited angiogenesis without affecting viability. CONCLUSION: Since low concentrations of TG deplete intracellular Ca2+ stores, it is concluded that these pools play a central role in mediating angiogenesis.


Asunto(s)
ATPasas Transportadoras de Calcio/antagonistas & inhibidores , Calcio/fisiología , Endotelio Vascular/efectos de los fármacos , Líquido Intracelular/metabolismo , Neovascularización Fisiológica/efectos de los fármacos , Tapsigargina/farmacología , Análisis de Varianza , Animales , Aorta , Calcimicina/farmacología , División Celular/efectos de los fármacos , Movimiento Celular/efectos de los fármacos , Células Cultivadas , Técnicas de Cultivo , Depresión Química , Relación Dosis-Respuesta a Droga , Inhibidores Enzimáticos/farmacología , Humanos , Hidrocortisona/farmacología , Hidroquinonas/farmacología , Ionomicina/farmacología , Ionóforos/farmacología , Masculino , Microcirculación , Fenoles/farmacología , Proteínas Tirosina Quinasas/antagonistas & inhibidores , Ratas , Ratas Sprague-Dawley , Arterias Umbilicales
16.
J Biol Chem ; 275(16): 11666-71, 2000 Apr 21.
Artículo en Inglés | MEDLINE | ID: mdl-10766785

RESUMEN

Catabolism of AMP during ATP breakdown produces adenosine, which restores energy balance. Catabolism of IMP may be a key step regulating purine nucleotide pools. Two, cloned cytosolic 5'-nucleotidases (cN-I and cN-II) have been implicated in AMP and IMP breakdown. To evaluate their roles directly, we expressed recombinant pigeon cN-I or human cN-II at similar activities in COS-7 or H9c2 cells. During rapid (more than 90% in 10 min) or slower (30-40% in 10 min) ATP catabolism, cN-I-transfected COS-7 and H9c2 cells produced significantly more adenosine than cN-II-transfected cells, which were similar to control-transfected cells. Inosine and hypoxanthine concentrations increased only during slower ATP catabolism. In COS-7 cells, 5'-nucleotidase activity was not rate-limiting for inosine and hypoxanthine production, which was therefore unaffected by cN-II- and actually reduced by cN-I- overexpression. In H9c2 cells, in which 5'-nucleotidase activity was rate-limiting, only cN-II overexpression accelerated inosine and hypoxanthine formation. Guanosine formation from GMP was also increased by cN-II. Our results imply distinct roles for cN-I and cN-II. Under the conditions tested in these cells, only cN-I plays a significant role in AMP breakdown to adenosine, whereas only cN-II breaks down IMP to inosine and GMP to guanosine.


Asunto(s)
5'-Nucleotidasa/fisiología , Adenosina Monofosfato/metabolismo , Inosina Monofosfato/metabolismo , Isoenzimas/fisiología , Músculos/metabolismo , 5'-Nucleotidasa/genética , Adenosina/metabolismo , Adenosina Trifosfato/metabolismo , Animales , Células COS , Línea Celular , Columbidae , Citosol/enzimología , Metabolismo Energético , Corazón/embriología , Humanos , Hipoxantina/metabolismo , Isoenzimas/genética , Cinética , Ratas , Proteínas Recombinantes/metabolismo , Transfección
18.
Arch Virol ; 144(11): 2185-99, 1999.
Artículo en Inglés | MEDLINE | ID: mdl-10603172

RESUMEN

The sequence of a 900-nucleotide segment (encoding part of the reverse transcriptase, including the entire RNase H domain) of the pol gene of the murine leukaemia virus (MLV) amphotropic strain 4070A is presented. Alignment of the inferred 4070A RNase H amino acid sequence (157 residues) with other MLV RNase H sequences revealed only minor differences compared with the divergence between other retroviral and prokaryotic or eukaryotic RNase H sequences. Only 10 residues were invariant across the entire sample set, but secondary structure predictions for the enzymes from E. coli, yeast, human liver and diverse retroviruses (HIV, Rous sarcoma virus, foamy viruses) supported, in every case, the five beta-strands (1 to 5) and four or five alpha-helices (A, B/C, D, E) that have been identified by crystallography in the RNase H domain of HIV-1 reverse transcriptase and in E. coli RNase H. In the case of MLV, analysis of the RNase H domain sequences inferred from 10 different strains (including the amphotropic 4070A) predicted all five alpha-helices (A-E), as well as beta-strands 4 and 5. However, the N-terminal segment (residues 1-40) was predicted, without exception and with high probability, to fold uniquely into one (or two adjacent) alpha-helix(es) encompassing residues 13-37, instead of the three beta-strands known to exist in the HIV-1 and E. coli enzymes. The unerring consistency between the known and predicted structures of the HIV-1 and E. coli enzymes, and the prediction of the same structural elements (including beta-strands 1-3 within the N-terminal segment) for all other (non-MLV) RNase H proteins examined in this study, suggests that the N-terminal segment of the MLV RNase H domain assumes a conformation distinct from that of other retroviral and cellular RNase H molecules. An additional (sixth) beta-strand was also predicted uniquely within the C-terminal region of foamy virus RNase H domains.


Asunto(s)
Virus de la Leucemia Murina/enzimología , Estructura Secundaria de Proteína , Ribonucleasa H/química , Secuencia de Aminoácidos , Animales , Secuencia de Bases , ADN Viral , Células Eucariotas/enzimología , Humanos , Ratones , Datos de Secuencia Molecular , Filogenia , Células Procariotas/enzimología , ADN Polimerasa Dirigida por ARN/genética , Retroviridae/enzimología , Ribonucleasa H/clasificación , Ribonucleasa H/genética , Análisis de Secuencia , Homología de Secuencia de Aminoácido
20.
J Expo Anal Environ Epidemiol ; 9(5): 414-26, 1999.
Artículo en Inglés | MEDLINE | ID: mdl-10554144

RESUMEN

The time/activity diary developed for use in the National Human Exposure Assessment Survey (NHEXAS) was completed by 249 participants in the Research Triangle Institute/Environmental and Occupational Health Sciences Institute (RTI/EOHSI) NHEXAS population-based pilot project conducted in the upper Midwest (EPA Region 5). The majority of participants successfully completed the diary during the 6-day study period. Participant responses showed internal consistency between related questions within the diary and between instruments used within the study. Comparison of response rates with the National Human Activity Pattern Survey, a nationwide population-based study, found consistent results when the same questions were used in both studies. Several questions identified age-specific activities. The value of the 6-day diary over 1-day surveys was apparent in discriminating between episodic and regularly conducted activities and in identifying subpopulations whose behavior may contribute to exposure to environmental pollutants.


Asunto(s)
Exposición a Riesgos Ambientales/análisis , Actividades Humanas , Registros Médicos , Adolescente , Adulto , Factores de Edad , Anciano , Niño , Gasolina , Great Lakes Region , Humanos , Persona de Mediana Edad , Proyectos Piloto , Reproducibilidad de los Resultados , Contaminación por Humo de Tabaco
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