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OBJECTIVE: To explore the association of frailty and its eight components with claims-based healthcare costs among South Korean older adults aged 66 from 2009 to 2012. DESIGN: A cross-sectional design. SETTING: Data were obtained from administrative claims, Regular Biennial General and Cancer Screening Examinations, and the 66-year Lifetime Transitional Period Health Examination. PARTICIPANTS: South Korean older adults aged 66 (N = 818,337). MEASUREMENTS: Frailty was measured using eight components (i.e., hospital admission, self-assessed health status, polypharmacy, weight loss, depressed mood, incontinence, visual and auditory problems, and performance on the Timed Up and Go test). Healthcare costs included those associated with inpatient and outpatient care and pharmaceuticals. Multiple Tobit regression was used to assess the association between frailty and healthcare costs before and after propensity score matching. RESULTS: The mean annual total healthcare cost was $1,403.24 in robust participants, $2,364.78 in pre-frail participants, and $3,655.13 in frail participants. Among participants after propensity score matching, total healthcare costs were higher by $959.58 in the pre-frail (P < 0.001) and by $2,249.70 in the frail group (P < 0.001) compared to the robust group. The presence of each of the eight frailty components was significantly associated with higher total healthcare costs. CONCLUSION: By comparing the variables of interest using claims data, our study showed that frailty and each of its eight symptoms was associated with increased healthcare costs. This provides evidence of the need for identifying and managing frailty to reduce healthcare costs among South Korean older adults.
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Fragilidad , Anciano , Estudios Transversales , Anciano Frágil , Costos de la Atención en Salud , Humanos , Equilibrio Postural , República de Corea , Estudios de Tiempo y MovimientoRESUMEN
BACKGROUND: We have developed the Atopic Dermatitis Symptom Score (ADSS) by which patients or parents can easily assess and record AD symptoms on a daily basis in a smartphone application. The aim of this study was to evaluate the reliability and validity of the ADSS. METHODS: We enrolled 307 children and adolescents with AD. Parents or caregivers were asked to record daily symptoms of the patients (itching, sleep disturbance, erythema, dryness, oozing, and edema) using a scale of 0-4. Statistical analyses consisted of the test-retest reliability, concurrent validity, minimal clinically important difference (MCID), responsiveness, floor or ceiling effects, and screening accuracy. Receiver-operating characteristic analyses were conducted to evaluate the ADSS cutoff point for predicting severe AD (SCORing AD [SCORAD] ≥40). RESULTS: Test-retest reliability between daytime and night-time ADSS was good (intraclass correlation coefficient, 0.82 [95% CI: 0.70-0.90]). An increase in ADSS was significantly associated with an increase in SCORAD (r = 0.64, P < .0001) (concurrent validity). The MCID was 4.1 points for the ADSS. There was a significant association between changes in ADSS and SCORAD (r = 0.56, P < .0001), indicating good responsiveness. At the optimal ADSS cutoff value of 7.0, sensitivity, specificity, and positive and negative predictive values were 88.4%, 78.6%, 21.1%, and 99.1%, respectively (screening accuracy). CONCLUSIONS: The ADSS can be a useful tool for self-assessment of skin symptoms in children with AD.
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Dermatitis Atópica/diagnóstico , Tamizaje Masivo/métodos , Adolescente , Cuidadores , Niño , Preescolar , Femenino , Humanos , Lactante , Estudios Longitudinales , Masculino , Aplicaciones Móviles , Padres , Curva ROC , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Índice de Severidad de la Enfermedad , Teléfono InteligenteRESUMEN
UNLABELLED: We conducted a comprehensive humidifier disinfectant exposure characterization for 374 subjects with lung disease who presumed their disease was related to humidifier disinfectant use (patient group) and for 303 of their family members (family group) for an ongoing epidemiological study. We visited the homes of the registered patients to investigate disinfectant use characteristics. Probability of exposure to disinfectants was determined from the questionnaire and supporting evidence from photographs demonstrating the use of humidifier disinfectant, disinfectant purchase receipts, any residual disinfectant, and the consistency of their statements. Exposure duration was estimated as cumulative disinfectant use hours from the questionnaire. Airborne disinfectant exposure intensity (µg/m(3)) was estimated based on the disinfectant volume (ml) and frequency added to the humidifier per day, disinfectant bulk level (µg/ml), the volume of the room (m(3)) with humidifier disinfectant, and the degree of ventilation. Overall, the distribution patterns of the intensity, duration, and cumulative exposure to humidifier disinfectants for the patient group were higher than those of the family group, especially for pregnant women and patients ≤6 years old. Further study is underway to evaluate the association between the disinfectant exposures estimated here with clinically diagnosed lung disease. PRACTICAL IMPLICATIONS: Retrospective exposure to household humidifier disinfectant as estimated here can be used to evaluate associations with clinically diagnosed lung disease due to the use of humidifier disinfectant in Korea. The framework, with modifications to account for dispersion and use patterns, can also be potentially adapted to assessment of other household chemical exposures.
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Contaminación del Aire Interior/análisis , Desinfectantes/análisis , Humidificadores , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Contaminación del Aire Interior/efectos adversos , Niño , Preescolar , Desinfectantes/efectos adversos , Femenino , Humanos , Enfermedades Pulmonares/epidemiología , Enfermedades Pulmonares/etiología , Masculino , Persona de Mediana Edad , Embarazo , República de Corea/epidemiología , Estudios Retrospectivos , Adulto JovenRESUMEN
Fetal arrhythmias are not uncommon in pregnancy. The diagnosis can be established on routine ultrasound scan. Fetal supraventricular tachycardia (SVT) is the most common cause of fetal tachycardia. If left undiagnosed and untreated, these fetuses may develop cardiac failure, hydrops fetalis and eventually death. We report two fetuses diagnosed antenatally to have fetal SVT. Both fetuses were in cardiac failure and were successfully treated with maternal administration of antiarrhythmic medications. Digoxin, and in severe instances, a combination with flecanaide significantly improved fetal outcomes and prevented fetal mortality. The long term prognosis of such patients are good.
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BACKGROUND: Subcortical vascular dementia (SVaD) is considered the most common type of vascular dementia and often follows a slowly progressive course, simulating Alzheimer disease (AD). Whether the progressive cognitive decline is associated with pure SVaD or concomitant AD remains unknown. The purpose of this study was to determine what proportion of patients with SVaD lack abnormal amyloid imaging, and to examine differences in the clinical or MRI features between subjects with SVaD with cortical amyloid deposition and those without. METHODS: We measured brain amyloid deposition using (11)C-Pittsburgh compound B (PiB) PET in 45 patients (men: women = 19:26; mean age 74.2 ± 7.6 years) with SVaD. They all met DSM-IV criteria for vascular dementia and had severe white matter high signal intensities without territorial infarction or macrohemorrhage on MRI. RESULTS: Thirty-one (68.9%) of 45 patients with SVaD were negative for cortical PiB binding. There was significant difference between (11)C-PiB-positive and (11)C-PiB-negative groups in terms of age (79.5 vs 71.9 years), Mini-Mental State Examination score (18.6 vs 22.6), the number of lacunes (3.9 vs 9.0), and the visual rating scale of hippocampal atrophy (3.1 vs 2.3). The neuropsychological assessments revealed that patients with (11)C-PiB-negative SVaD performed better on the delayed recall of both the verbal and visual memory test than did those with (11)C-PiB-positive scan. CONCLUSION: SVaD without abnormal amyloid imaging was more common than expected. Patients with SVaD with and without abnormal amyloid imaging differed in clinical and MRI features, although there was considerable overlap.
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Benzotiazoles , Mapeo Encefálico , Radioisótopos de Carbono , Demencia Vascular/diagnóstico por imagen , Anciano , Anciano de 80 o más Años , Compuestos de Anilina , Atrofia/diagnóstico por imagen , Atrofia/patología , Distribución de Chi-Cuadrado , Demencia Vascular/complicaciones , Demencia Vascular/patología , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Imagen por Resonancia Magnética/métodos , Masculino , Persona de Mediana Edad , Trastornos del Movimiento/etiología , Pruebas Neuropsicológicas , Tomografía de Emisión de Positrones/métodos , Escalas de Valoración Psiquiátrica , Lóbulo Temporal/diagnóstico por imagen , Lóbulo Temporal/patología , TiazolesRESUMEN
OBJECTIVE: The aim of this study was to estimate the prevalence of multiple sclerosis (MS) in Korea through a nationwide survey. METHODS: We estimated the prevalence of MS in Korea using several sources collected between 2000 and 2005: verified cases from 38 major referral hospitals across the nation, the National Health Insurance (NHI) payment request data from NHI Corporation of Korea, and the national mortality dataset from Statistics Korea. We established a network of neurologists from 38 major referral hospitals and performed a nationwide hospital survey for MS cases. The diagnoses of MS were validated according to the McDonald criteria. The diagnostic validity of each hospital was evaluated from hospital survey data to reduce the uncertainty of NHI data and was applied to estimate the prevalence using novel statistical methods. RESULTS: The estimated numbers of MS cases in Korea through 2 different statistical methods which adjust NHI data by the diagnostic validity of each hospital were very similar: 1,681 (95% confidence interval [CI] 1,490-1,902) by the stratification method and 1,640 (95% CI 1,402-1,789) by the linear regression method. The crude MS prevalence was 3.5-3.6 cases per 100,000 individuals. The estimated female-to-male ratio was 1.26. CONCLUSION: This study is the first nationwide survey for the prevalence of MS in Korea utilizing a national database in complementary way. We found an increase in the prevalence of MS that is consistent with reports from neighboring Asian countries.
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Esclerosis Múltiple/epidemiología , Adolescente , Adulto , Distribución por Edad , Anciano , Preescolar , Femenino , Encuestas Epidemiológicas , Humanos , Lactante , Recién Nacido , Seguro de Salud/estadística & datos numéricos , Corea (Geográfico)/epidemiología , Masculino , Persona de Mediana Edad , Esclerosis Múltiple/mortalidad , Prevalencia , Reproducibilidad de los Resultados , Estudios Retrospectivos , Distribución por SexoRESUMEN
Volatile organic compounds (VOCs) are reported to cause adverse effects on pulmonary function in occupationally exposed workers. However, evidence is lacking on the effect in the general population. We hypothesised that VOCs impair pulmonary function through enhancing oxidative stress, especially in the elderly population. A longitudinal panel study of 154 elderly people was performed in South Korea. Repeated spirometric tests were performed up to eight times on different days for each subject. We also measured urinary concentrations of metabolites of the VOC and markers of oxidative stress (malondialdehyde and 8-oxo-2'-deoxyguanosine) on the same day of spirometric tests. A mixed linear regression model was used to evaluate the association among the VOC metabolites, oxidative stress markers and spirometric tests. We found that the urinary levels of hippuric acid and methylhippuric acid, which are metabolites of toluene and xylene, respectively, were significantly associated with reduction of forced expiratory volume in 1 s (FEV1), FEV1/forced vital capacity (FVC), and forced expiratory flow at 25-75% of FVC. We also found significant associations between the metabolites of VOCs and the markers of oxidative stress. In addition, the oxidative stress markers were associated with pulmonary function parameters. This study suggests that exposure to toluene and xylene exert a harmful effect on pulmonary function by exacerbating oxidative stress in elderly people.
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Exposición a Riesgos Ambientales , Enfermedades Pulmonares/inducido químicamente , Pulmón/efectos de los fármacos , Estrés Oxidativo , Tolueno/toxicidad , Compuestos Orgánicos Volátiles/toxicidad , Xilenos/toxicidad , 8-Hidroxi-2'-Desoxicoguanosina , Anciano , Anciano de 80 o más Años , Desoxiguanosina/análogos & derivados , Desoxiguanosina/orina , Femenino , Hipuratos/orina , Humanos , Estudios Longitudinales , Pulmón/fisiopatología , Enfermedades Pulmonares/fisiopatología , Masculino , Malondialdehído/orina , Persona de Mediana Edad , República de Corea , Respiración/efectos de los fármacos , Pruebas de Función Respiratoria , Tolueno/metabolismo , Compuestos Orgánicos Volátiles/metabolismo , Xilenos/metabolismoRESUMEN
The influenza A virus, a severe pandemic pathogen, has a segmented RNA genome consisting of eight single-stranded RNA molecules. The 5' and 3' ends of each RNA segment recognized by the influenza A virus RNA-dependent RNA polymerase direct both transcription and replication of the virus's RNA genome. Promoter binding by the viral RNA polymerase and formation of an active open complex are prerequisites for viral replication and proliferation. Here we describe the solution structure of this promoter as solved by multidimensional, heteronuclear magnetic resonance spectroscopy. Our studies show that the viral promoter has a significant dynamic nature and reveal an unusual displacement of an adenosine that forms a novel (A-A) x U motif and a C-A mismatch stacked in a helix. The characterized structural features of the promoter imply that the specificity of polymerase binding results from an internal RNA loop. In addition, an unexpected bending (46 +/- 10 degrees ) near the initiation site suggests the existence of a promoter recognition mechanism similar to that of DNA-dependent RNA polymerase and a possible regulatory function for the terminal structure during open complex formation.
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Virus de la Influenza A/genética , Conformación de Ácido Nucleico , Regiones Promotoras Genéticas , ARN Viral/biosíntesis , ARN Viral/químicaRESUMEN
Chemical analysis of spent Co/Mo/gamma Al(2)O(3) catalyst revealed the presence of carbon, molybdenum, sulfur, vanadium and cobalt at levels of 16.0, 10.9, 7.3, 4.6 and 4.0 wt.%, respectively. It was found that calcination at 500 degrees C provides an effective solution for the removal of carbon and sulfur and this generates the oxide form of the heavy metals. The removal of these heavy metals can be achieved through a two-stage leaching process. During the first stage, in which concentrated ammonia is used and it has been found that this process can be successful in removing as much as 83% (w/v) Mo. In a second stage, it was found that using 10% (v/v) of sulfuric acid, it was possible to account for up to 77% (w/v) Co and 4% (w/v) Mo removal. Leaching test results indicated that the vanadium present in the heated spent catalyst was almost stabilized but the molybdenum and cobalt were not. The combination of two solid wastes, ladle furnace slag (LFS) and treated residue of spent catalyst, could be used for making a high value-added anorthite glass-ceramic materials. Further leaching tests showed that ceramic glass materials provided a very effective method of Co, Mo and V heavy metals stabilization resulting in a product with a possible commercial value.
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Contaminación Ambiental/prevención & control , Metales Pesados/análisis , Silicatos de Aluminio/química , Catálisis , Cerámica/química , Vidrio/química , Metales Pesados/química , Petróleo , Eliminación de Residuos/métodosRESUMEN
The 20-nucleotide SL1 VBS RNA, 5'-GGAGACGC[GAUUC]GCGCUCC (bulged A underlined and loop bases in brackets), plays a crucial role in viral particle binding to the plus strand and packaging of the RNA. Its structure was determined by NMR spectroscopy. Structure calculations gave a precisely defined structure, with an average pairwise root mean square deviation (RMSD) of 1.28 A for the entire molecule, 0.57 A for the loop region (C8-G14), and 0.46 A for the bulge region (G4-G7, C15-C17). Base stacking continues for three nucleotides on the 5' side of the loop. The final structure contains a single hydrogen bond involving the guanine imino proton and the carbonyl O(2) of the cytosine between the nucleotides on the 5' and 3' ends of the loop, although they do not form a Watson-Crick base pair. All three pyrimidine bases in the loop point toward the major groove, which implies that Cap-Pol protein may recognize the major groove of the SL1 loop region. The bulged A5 residue is stacked in the stem, but nuclear Overhauser enhancements (NOEs) suggest that A5 spends part of the time in the bulged-out conformation. The rigid conformation of the upper stem and loop regions may allow the SL1 VBS RNA to interact with Cap-Pol protein without drastically changing its own conformation.
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ARN Lider Empalmado/química , Saccharomyces cerevisiae/química , Saccharomyces cerevisiae/virología , Proteínas Virales/química , Secuencia de Bases , Ácido Edético/farmacología , Espectroscopía de Resonancia Magnética , Modelos Moleculares , Datos de Secuencia Molecular , Conformación de Ácido Nucleico , Fosfatos/farmacología , Protones , ARN/químicaRESUMEN
To determine relatively useful diagnostic procedures of carbon disulfide (CS2) poisoning in terms of validity and cost-effectiveness, several diagnostic tests are evaluated on 1,552 people by prevalence ratio (exposed/nonexposed), dose-response relationship, sensitivity and specificity, and the cost of the tests. Several symptoms with high kappa indices are found to be useful in various combinations, showing a consistent dose-response relationship and high exposed-nonexposed ratio. In clinicopathologic tests on functions of the kidney, liver and hematopoietic systems, eight items out of 22 have been shown to have significant dose-response relationship, mostly in liver function tests. A thorough dental examination failed to identify any useful indicator peculiar to the CS2 poisoning. Unlike Western people, the prevalence of coronary heart disease among Koreans was too low to be useful in the diagnosis of CS2 poisoning. Among four elective tests, i.e., Minnesota Multiphasic Personality Inventory (MMPI), Brain magnetic resonance imaging (MRI), nerve conduction velocity (NCV), and fluorescent angiography (FAG), the NCV appeared to be a more sensitive and specific test than the others are. Combinations of the tests improved the probability of diagnosing CS2 poisoning cases when any one test out of four was positive. Addition of other valid tests increased the probability of excluding non-cases. It was concluded that diagnosis of CS2 poisoning could be made validly and inexpensively if the diagnostic tests were carefully chosen step by step.
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Disulfuro de Carbono/envenenamiento , Conducción Nerviosa/efectos de los fármacos , Exposición Profesional , Inventario de Personalidad , Adolescente , Adulto , Anciano , Angiografía , Encéfalo/patología , Análisis Costo-Beneficio , Femenino , Humanos , Imagen por Resonancia Magnética/economía , Imagen por Resonancia Magnética/normas , Masculino , Tamizaje Masivo , Persona de Mediana Edad , Inventario de Personalidad/normas , Sensibilidad y EspecificidadRESUMEN
CpG oligodeoxynucleotides (ODNs) are promising immunomodulatory agents for treating human diseases and vaccine development. Phosphodiester CpG ODNs were demonstrated to have poor immunostimulatory potentials for cytokine production. However, the conjugation of consecutive deoxyriboguanosine residues, called a dG run, at the 3' terminus of phosphodiester CpG ODNs significantly enhanced TNF-alpha and IL-12 production from mouse splenic dendritic cells (DCs). The optimal induction of cytokine production was achieved by the addition of a hexameric dG (dG6) run. In contrast, the existence of a dG6 run either at the 5' terminus of phosphodiester CpG ODNs or at the 3' terminus of phosphorothioate CpG ODNs diminished CpG-mediated cytokine induction, suggesting that the effects of a dG run depend on its location and the chemical property of the ODN backbone, respectively. In addition, we provided the evidence that the conjugation of a dG6 run caused the structural transformation of CpG ODNs, which facilitates their targeting into mouse APCs such as splenic DCs, B cells, and peritoneal macrophages with a scavenger receptor type A ligand specificity. Among primary APCs, DCs were the most potent for CpG ODN-mediated IL-12 production. Furthermore, we demonstrated that the conjugation of a dG6 run into the 3' terminus of phosphodiester CpG ODNs was crucial for their ability to generate Th1 immunity in vivo. Thus, the conjugation of a dG6 run into phosphodiester CpG ODNs would be an alternative way to optimize their immunostimulatory potentials in vitro and in vivo.
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Adyuvantes Inmunológicos/administración & dosificación , Islas de CpG/inmunología , Desoxiguanosina/inmunología , Proteínas de la Membrana , Conformación de Ácido Nucleico , Oligodesoxirribonucleótidos/inmunología , Receptores de Lipoproteína , Regiones no Traducidas 3'/inmunología , Regiones no Traducidas 5'/inmunología , Adyuvantes Inmunológicos/química , Adyuvantes Inmunológicos/metabolismo , Animales , Citocinas/biosíntesis , Células Dendríticas/inmunología , Células Dendríticas/metabolismo , Desoxiguanosina/administración & dosificación , Desoxiguanosina/química , Desoxiguanosina/metabolismo , Femenino , Inmunidad Celular , Inyecciones Subcutáneas , Ligandos , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Oligodesoxirribonucleótidos/administración & dosificación , Oligodesoxirribonucleótidos/química , Oligodesoxirribonucleótidos/metabolismo , Receptores Inmunológicos/metabolismo , Receptores Depuradores , Receptores Depuradores de Clase A , Receptores Depuradores de Clase B , Transducción de Señal/inmunología , Bazo/citología , Bazo/inmunología , Bazo/metabolismo , Células TH1/inmunologíaRESUMEN
Acrylamide (AA) is a carcinogen in experimental animals. Glycidamide (GA), formed by metabolic epoxidation of AA, is believed to be responsible for the carcinogenicity of AA. Occupational exposure to AA has been assessed earlier by measurement of its adducts with N-terminal valine in hemoglobin. A background of AA adducts [N-(2-carbamoylethyl)valine (AAVal), about 30 pmol/g globin] was found in individuals without known exposure to the compound. The method previously available for adducts of GA only allowed analysis of samples from highly exposed individuals and showed similar levels of AAVal and adducts of GA [N-(2-hydroxy-2-carbamoylethyl)valine (GAVal)]. We have developed a sensitive method for simultaneous quantification of adducts of GA and AA, which is suitable down to low exposure levels. The method is based on the so-called modified Edman method, where globin is reacted with pentafluorophenyl isothiocyanate under neutral conditions. The valine adducts are then extracted in the form of pentafluorophenylthiohydantoin (PFPTH) derivatives. The analytical procedure included reaction of the PFPTH derivatives with acetic anhydride in order to protect the hydroxyl group of GAVal. The PFPTH derivatives of AAVal and GAVal were analyzed by gas chromatography/tandem mass spectrometry. ((2)H(3))AAVal-PFPTH was used as the internal standard. The method was applied to samples from 11 workers at an AA production plant, 1 nonexposed nonsmoker, and a few participants of a smoking cessation program. AAVal levels were in the range 27-1854 pmol/g globin. Recorded levels of GAVal were 3-12% of those of AAVal, suggesting that previous measurements of GAVal overestimate GAVal at low levels of exposure to AA.
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Acrilamida/sangre , Compuestos Epoxi/sangre , Hemoglobinas/metabolismo , Acrilamida/química , Compuestos Epoxi/química , Cromatografía de Gases y Espectrometría de Masas/métodos , Globinas/química , Globinas/metabolismo , Hemoglobinas/química , Humanos , Exposición Profesional , Oligopéptidos/química , Unión Proteica , ValinaRESUMEN
OBJECTIVES: To evaluate exposure to mixed solvents containing ethylene glycol monoethyl ether acetate (EGEEA) in shipyard painters, to determine if EGEEA is toxic to the bone marrow. METHODS: An industrial hygiene survey was performed to identify exposure to EGEEA of two groups of shipyard painters, a low exposure group (n = 30) and a high exposure group (n = 27). Urinary ethoxyacetic acid and methyl hippuric acid as well as haemoglobin, packed cell volume, red cell indices, total and differential white blood cell counts (WBCs), and platelet count for the shipyard painters and the control subjects were measured. RESULTS: The mean (range) exposure concentration (ppm) to EGEEA in the high and low exposure groups were 3.03 (not detectable to 18.27), 1.76 (not detectable to 8.12), respectively. The concentrations of methyl hippuric acid and ethoxyacetic acid in the high exposure group were significantly higher than those in the control group. The mean WBCs in the high exposure group were significantly lower than in the control group, and a significant proportion, six (11%) of the 57 painters, were leucopenic; none of the controls were affected. CONCLUSION: The high rate of possible haematological effects among shipyard painters and a hygienic evaluation of their working environment in the present study suggests that EGEEA might be toxic to bone marrow.
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Glicoles de Etileno/administración & dosificación , Enfermedades Hematológicas/inducido químicamente , Enfermedades Profesionales/inducido químicamente , Pintura/efectos adversos , Teratógenos , Adulto , Recuento de Células Sanguíneas/efectos de los fármacos , Médula Ósea/efectos de los fármacos , Estudios Transversales , Monitoreo del Ambiente/métodos , Glicoles de Etileno/efectos adversos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Exposición Profesional , NavíosRESUMEN
It is difficult to distinguish manganism from idiopathic parkinsonism by clinical signs only. Case history and examination: A 48-year-old welder for over 10 years complained of masked face, right side (arm and leg) resting tremor, and bradykinesia for over one year. Magnetic resonance imaging (MRI) findings showed symmetrical high signal intensities in the globus pallidus on T1 weighted image. These intensities disappeared almost completely six months after cessation of exposure. 18F-6-fluorodopa (18F-dopa) positron emission tomography (PET) findings showed reduced 18F-dopa uptake in the left putamen, findings which appear in idiopathic parkinsonism. A PET study is necessary to distinguish manganism from idiopathic parkinsonism, especially in a working environment with elevated Mn concentrations, such as welding.
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Dihidroxifenilalanina/farmacocinética , Intoxicación por Manganeso , Exposición Profesional/efectos adversos , Enfermedad de Parkinson/diagnóstico , Putamen/metabolismo , Diagnóstico Diferencial , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Tomografía Computarizada de Emisión/métodosRESUMEN
RATIONALE AND OBJECTIVES: High signal intensity in the basal ganglia on T1-weighted MR imaging has been reported in chronic manganese (Mn) poisoning. However, the exact meaning of the high signal intensity remains unclear: does it result from Mn itself, secondary pathologic changes of the brain tissue, or both? The goal of this study was to evaluate the sequential change of MR signal intensity and to correlate the MR intensity of the globus pallidus and the hypothalamus with the Mn concentration in the blood and the brain tissue, and with the histopathologic findings. METHODS: Ten milligrams per kilogram of Mn was administered once a week for 4 weeks to 14 rabbits. The rabbits in the control group (n = 2) were killed without Mn administration; those in group I (n = 4) were killed 1 day after the completion of Mn administration, those in group II (n = 4) were killed at 4 weeks, and those in group III (n = 6) were killed at 8 weeks. Sequential MR imaging, blood and tissue concentration measurement, and pathologic examination were performed. Sequential changes of the percent contrasts, contrast-to-noise ratios, and T1 relaxation times were analyzed with blood and tissue concentrations and histopathologic findings. RESULTS: The signal intensity of the basal ganglia on T1-weighted imaging was highest 1 day after cessation of Mn administration and sequentially washed out. The contrast, contrast-to-noise ratio, and T1 relaxation time showed significant correlations with blood concentration. Only the T1 relaxation time of the globus pallidus showed a significant correlation with tissue concentration. Histopathologic examination disclosed mild abnormalities in the globus pallidus, thalamus, and hypothalamus. CONCLUSIONS: The high signal intensity on T1-weighted MR imaging presumably indicates mainly the exposure marker of Mn, although mild pathologic findings were observed.
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Encéfalo/patología , Imagen por Resonancia Magnética , Intoxicación por Manganeso , Animales , Encéfalo/efectos de los fármacos , Manganeso/análisis , Conejos , Factores de TiempoRESUMEN
The structure of a 34 nucleotide RNA molecule in solution, which contains the conserved panhandle sequences, was determined by NMR spectroscopy and molecular modeling. The partially double-strandedpanhandle structure of the influenza virus RNA serves to regulate initiation and termination of viral transcription as well as polyadenylation. The panhandle RNA consists of internal loop flanked by short helices. The nucleotides at or near the internal loop are crucial for polymerase binding and transcriptional activity. They show more flexible conformational character than the Watson-Crick base-paired region, especially for the backbone torsion angles of alpha, gamma and delta. Although residues A10 and A12 are stacked in the helix, the phosphodiester backbones are distorted. Residues A12, A13 and G25 show dynamic sugar conformations and the backbone conformations of these nucleotides are flexible. This backbone conformation and its associated flexibility may be important for protein-RNA interactions as well as base-specific interactions.
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Conformación de Ácido Nucleico , Orthomyxoviridae/genética , ARN Viral/química , Espectroscopía de Resonancia Magnética , Modelos Moleculares , ARN Viral/genética , Relación Estructura-Actividad , Transcripción GenéticaRESUMEN
OBJECTIVES: To clarify the clinical significance of increased signal intensities on T1 weighted magnetic resonance imaging (MRI) we performed a large-scale epidemiological study on asymptomatic manganese (Mn)-exposed workers with its focus on MRI. METHODS: We randomly selected 121 male workers out of a total of 750 workers including Mn-exposed, non-exposed manual, and non-exposed clerical workers in the factories. We studied environmental and biological monitoring, neurological examination, and MRI. RESULTS: The proportion of workers with increased signal intensities among the exposed, the non-exposed manual workers, and the non-exposed clerical workers was 46.1%, 18.8%, and 0%, respectively. Especially, 73.5% of the welders showed increased signal intensities. In no subject, were clinical signs of manganism observed. The pallidal index correlated with blood Mn concentration. CONCLUSION: Increase in signal intensities on the T1-weighted image reflect recent exposure to Mn, but not necessarily manganism. At which increase of signal intensity, the progression of manganism from Mn exposure occurs, remains to be solved.
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Encéfalo/efectos de los fármacos , Imagen por Resonancia Magnética , Intoxicación por Manganeso/patología , Manganeso/sangre , Exposición Profesional/efectos adversos , Transducción de Señal/efectos de los fármacos , Adulto , Encéfalo/patología , Humanos , Corea (Geográfico) , Masculino , Intoxicación por Manganeso/etiología , Encuestas y CuestionariosRESUMEN
Manganese (Mn) intoxication is known to induce parkinsonism. Mn-induced parkinsonism preferentially affect the globus pallidus in contrast to idiopathic parkinsonism where degeneration predominantly involves the nigral pars compacta. We describe a 51-year-old man who had been occupationally exposed to Mn. He had parkinsonian features including masked face, resting tremor, and bradykinesia. He also had a cock walk and a particular propensity to fall in a backward gait. There was no sustained therapeutic response to levodopa. A fluorodopa PET scan was normal. This case indicates that Mn-induced parkinsonism can be differentiated from idiopathic parkinsonism in that the former has unique clinical features and a normal fluorodopa PET scan.
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Manganeso , Enfermedad de Parkinson Secundaria/inducido químicamente , Humanos , Masculino , Persona de Mediana Edad , Enfermedad de Parkinson Secundaria/diagnóstico por imagen , Radiografía , Tomografía Computarizada de EmisiónRESUMEN
The double-stranded panhandle structure of the influenza virus RNA is important for replication, transcription and packaging into the virion of the virion RNA. The solution structure of a 34 nt RNA which contains the conserved panhandle sequences has been investigated by one- and two-dimensional NMR spectroscopy. The partially complementary 5'- and 3'-ends of the RNA form a double helical structure which is, on average, close to A-form. The stem contains bulges at nucleotides A10, A12 and C26. In between these bulges, C11 and G25 form a Watson-Crick base pair. The structural features of the panhandle provide a framework for the explanation of mutational analysis and for a better understanding of RNA-polymerase interactions.