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1.
Cancer Causes Control ; 23(11): 1831-7, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22971999

RESUMO

PURPOSE: Disparities in solid tumors have been well studied. However, disparities in hematologic malignancies have been relatively unexplored on population-based levels. The purpose of this study is to examine the relationship between race/ethnicity and acute leukemia mortality. METHODS: All patients with acute leukemia [acute lymphoblastic leukemia (ALL) and acute myelogenous leukemia (AML)] were identified in the Surveillance Epidemiology and End Results database, 1999-2008. Kaplan-Meier curves were generated to reflect survival probabilities by race/ethnicity. Multivariable Cox proportional hazard models estimated hazard of mortality by race with adjustment for individual (age, gender, year of diagnosis) and select genetic factors. RESULTS: A total of 39,002 patients with acute leukemia were included in the study. Overall, there was a mortality disparity in acute leukemia for blacks (HR 1.17, p < 0.0001) and Hispanics (HR 1.13, p < 0.0001) compared with non-Hispanic whites. In stratified analysis, disparities in ALL were greater than AML; blacks (HR[ALL]1.45, p < 0.0001; HR[AML]1.12, p < 0.0011); Hispanics (HR[ALL]1.46, p < 0.0001; HR[AML]1.06, p < 0.0001). Adjustment for individual patient and select genetic factors did not explain disparities. CONCLUSIONS: Blacks and Hispanics suffer decreased survival in acute leukemia as compared to others. Further investigation is needed to understand the drivers of poor cancer outcomes in these populations.


Assuntos
Disparidades em Assistência à Saúde/estatística & dados numéricos , Leucemia Mieloide Aguda/etnologia , Leucemia Mieloide Aguda/mortalidade , Leucemia-Linfoma Linfoblástico de Células Precursoras/etnologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/mortalidade , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Detecção Precoce de Câncer , Etnicidade , Feminino , Disparidades em Assistência à Saúde/etnologia , Humanos , Leucemia Mieloide Aguda/epidemiologia , Leucemia Mieloide Aguda/patologia , Masculino , Pessoa de Meia-Idade , Leucemia-Linfoma Linfoblástico de Células Precursoras/epidemiologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Programa de SEER , Estados Unidos/epidemiologia , Adulto Jovem
2.
Neurology ; 66(10): 1506-10, 2006 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-16717209

RESUMO

BACKGROUND: Hyperinsulinemia and insulin resistance are risk factors for memory impairment and Alzheimer disease (AD). Insulin regulates levels of the amyloid beta-peptide (Abeta) in vitro in neuronal cultures and in vivo in the CSF of normal older adults. OBJECTIVE: To determine whether insulin affected plasma Abeta levels and whether such effects differed for patients with AD compared with normal older adults. METHODS: Fifty-nine patients with AD and 50 healthy older adults each received infusions of saline and of insulin (1.0 mU.kg(-1).min(-1)) with accompanying dextrose to maintain euglycemia. A subset of participants (19 AD, 12 normal) received two additional conditions, in which insulin was infused at a lower (0.33 mU.kg(-1).min(-1)) and higher (1.67 mU.kg(-1).min(-1)) rate. Plasma insulin and Abeta were measured after 120 minutes of infusion. RESULTS: Adults with AD had higher plasma insulin vs normal adults at the two higher infusion rates, despite receiving comparable amounts of insulin. For normal adults, insulin reduced plasma Abeta levels at the middle (1.0 mU.kg(-1).min(-1)) dose, with attenuated effects at lower and higher doses. In contrast, for patients with AD, insulin raised plasma Abeta levels at the two higher doses (1.0 and 1.67 mU.kg(-1).min(-1)). CONCLUSIONS: These results suggest that patients with Alzheimer disease (AD) have reduced insulin clearance and insulin-provoked plasma amyloid beta-peptide (Abeta) elevation. Abnormal regulation of peripheral Abeta by insulin may contribute to AD risk.


Assuntos
Doença de Alzheimer/sangue , Peptídeos beta-Amiloides/sangue , Insulina/farmacologia , Fragmentos de Peptídeos/sangue , Idoso , Idoso de 80 Anos ou mais , Apolipoproteínas E/genética , Índice de Massa Corporal , Relação Dose-Resposta a Droga , Feminino , Genótipo , Técnica Clamp de Glucose , Humanos , Hiperinsulinismo/sangue , Insulina/administração & dosagem , Masculino , Pessoa de Meia-Idade
3.
Appl Microbiol Biotechnol ; 63(5): 571-7, 2004 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-12908086

RESUMO

Transformation of carbon tetrachloride (CT) by Shewanella oneidensis MR-1 has been proposed to involve the anaerobic respiratory-chain component menaquinone. To investigate this hypothesis a series of menaquinone mutants were constructed. The menF mutant is blocked at the start of the menaquinone biosynthetic pathway. The menB, menA and menG mutants are all blocked towards the end of the pathway, being unable to produce 1,4-dihydroxy-2-naphthoic acid (DHNA), demethyl-menaquinone and menaquinone, respectively. Aerobically grown mutants unable to produce the menaquinone precursor DHNA (menF and menB mutants) showed a distinctly different CT transformation profile than mutants able to produce DHNA but unable to produce menaquinone (menA and menG mutants). While DHNA did not reduce CT in an abiotic assay, the addition of DHNA to the menF and menB mutants restored normal CT transformation activity. We conclude that a derivative of DHNA, that is distinct from menaquinone, is involved in the reduction of CT by aerobically grown S. oneidensis MR-1. When cells were grown anaerobically with trimethylamine-N-oxide as the terminal electron acceptor, all the menaquinone mutants showed wild-type levels of CT reduction. We conclude that S. oneidensis MR-1 produces two different factors capable of dehalogenating CT. The factor produced under anaerobic growth conditions is not a product of the menaquinone biosynthetic pathway.


Assuntos
Tetracloreto de Carbono/metabolismo , Naftóis/química , Naftóis/metabolismo , Shewanella/crescimento & desenvolvimento , Shewanella/metabolismo , Aerobiose , Alquil e Aril Transferases/genética , Alquil e Aril Transferases/metabolismo , Alquil e Aril Transferases/fisiologia , Anaerobiose , Biotransformação , Genes Bacterianos , Cinética , Metilaminas/metabolismo , Mutação , Oxirredução , Vitamina K 2/química , Vitamina K 2/metabolismo
4.
Anal Chem ; 73(10): 2338-44, 2001 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-11393861

RESUMO

Single-particle mass spectrometers are now commonly used to analyze atmospheric particles and generate tens of thousands of spectra from typical measurement campaigns. The ART-2a spectrum algorithm has been used to classify these spectra. In this work, we generate a range of particles that are models of those that are common in the atmosphere. A single-particle mass spectrometer is used to analyze these known particles, and the spectra are classified using ART-2a. The optimum vigilance parameter is approximately 0.5 while the optimum learning rate is approximately 0.05. The classifications elucidate limitations in generation of test particles, their analysis by single-particle techniques, and their classification by ART-2a.

5.
Environ Manage ; 26(6): 589-94, 2000 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11029110

RESUMO

The estimated cost of repairing damage caused to recreational sites annually is in the hundreds of millions of dollars. These depreciative activities also reduce the quality of visitors' experiences in the damaged areas. Indirect methods, such as visitor education through brochures and signs, continue to be the least controversial management approaches to depreciative acts. Yet, the literature on studies examining the most effective message presentations remains sparse. A survey mailed to randomly selected National Association for Interpretation members assessed the perceived effectiveness of communications that encouraged positive conduct (prescriptive messages) versus those that discouraged negative conduct (proscriptive messages) in wildland and urban settings. Almost invariably, respondents viewed the encouragement-based prescriptive messages as more effective than the discouragement-based proscriptive messages. This finding stands in sharp contrast to an earlier study that discovered a preponderance of proscriptive versus prescriptive messages on signs in both wildland and urban recreational environments. Thus, although the great majority of interpreters see the encouragement of positive conduct as more effective, in practice, messages on signs are much more likely to discourage negative conduct. Reasons for this discrepancy are considered.

6.
Mayo Clin Proc ; 73(4): 301-8, 1998 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-9559032

RESUMO

OBJECTIVE: To test the simultaneous effect of various established predictors of breast and cervical cancer screening (breast self-examination, clinical breast examination by a physician, Papanicolaou [Pap] smear, and pelvic examination) in a low-income, Mexican-American sample. MATERIAL AND METHODS: A total of 188 Mexican-American women participated in a face-to-face structured interview in their preferred language. We tested a model with four established predictors of breast and cervical cancer screening--communication skills, knowledge of cancer, access to health care (finances and availability of care), and anxiety about cancer. Simultaneous structural equations analysis was used to form latent variables and to control for the effect of all predictors concurrently. RESULTS: Screening behavior was inversely associated with anxiety about cancer when all other predictors were statistically controlled. In addition, anxiety substantially affected the relationship between communication skills and screening behavior. Unexpectedly, knowledge of cancer was positively, rather than negatively, associated with anxiety about cancer. Predictors in the model demonstrated an excellent fit of the proposed model to the data. CONCLUSION: Successful cancer screening programs for Mexican-American women must address not only access barriers but also communication skills, knowledge, and, perhaps most importantly, anxiety.


Assuntos
Neoplasias da Mama/prevenção & controle , Comportamentos Relacionados com a Saúde , Programas de Rastreamento , Americanos Mexicanos/estatística & dados numéricos , Neoplasias do Colo do Útero/prevenção & controle , Saúde da Mulher , Ansiedade , Neoplasias da Mama/psicologia , Comunicação , Feminino , Conhecimentos, Atitudes e Prática em Saúde , Acessibilidade aos Serviços de Saúde , Humanos , Inquéritos e Questionários , Neoplasias do Colo do Útero/psicologia
7.
J Psychosom Res ; 44(2): 241-50, 1998 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9532553

RESUMO

The purpose of this study was to test the role of "denial" (spouse/friend minus self-ratings on parallel versions of the same questionnaire) in diluting the predictive value of emotional distress for cardiac events (deaths, new MIs, and/or revascularizations). One hundred forty-four men with no history of prior revascularization who had at least minimally positive diagnostic coronary angiograms, and someone they selected as "someone who knows you well," completed parallel versions of the Ketterer Stress Symptom Frequency Checklist (KSSFC). They were followed up by phone an average of 59.7 months after recruitment. Length of follow-up, baseline cardiac risk factors, and a number of baseline-obtained psychosocial risk factors were tested as prospective predictors of combined events (death by any cause, new MIs, and/or revascularizations) and current anginal frequency. Only spouse/friend observed anxiety on the KSSFC predicted current anginal frequency (p = 0.001). On the self-report version of the KSSFC, patients with one or more events reported less anger (p = 0.031), depression (p = 0.008), and anxiety (p = 0.003). These results may be attributable to "denial" because there were no differences in spouse/friend ratings, and difference scores (spouse/friend minus patient) on the KSSFC scales, particularly anger, were also related to events: AIAI (p = 0.002); depression (p = 0.063); and anxiety (p = 0.010). Denial may be a major limiting factor in accurately assessing emotional distress in cardiac populations, and may help account for a number of the previous findings.


Assuntos
Negação em Psicologia , Isquemia Miocárdica/diagnóstico , Isquemia Miocárdica/psicologia , Angiografia/métodos , Transtornos de Ansiedade/diagnóstico , Transtornos de Ansiedade/psicologia , Estudos Transversais , Transtorno Depressivo/diagnóstico , Transtorno Depressivo/psicologia , Seguimentos , Humanos , Entrevista Psicológica , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Retrospectivos , Fatores de Risco , Índice de Gravidade de Doença , Estresse Psicológico/psicologia , Gravação de Videoteipe
8.
J Behav Med ; 19(5): 455-66, 1996 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8904728

RESUMO

The present study examined traditional risk factors and various indices of emotional distress in males with positive angiograms (N = 122), "syndrome X" males with negative or nominal results on angiogram (N = 53), and age- and socioeconomic status-matched males with no manifest history of otherosclerotic disease (N = 56). Syndrome X patients reported more depression on the Ketterer Stress Symptom Frequency Checklist (KSSFC) than positive angiographic patients. And compared with healthy controls, they were more likely to be perceived by a spouse/friend as depressed and anxious on the KSSFC, scored higher on the Framingham Type A Scale, and reported more unprovoked nocturnal awakening. Syndrome X patients generally appear to be similar to patients with positive angiograms with regard to traditional risk factor history but are more distressed than healthy controls. This becomes most evident when denial is circumvented by discussion with significant others or inquiries are "framed" appropriately.


Assuntos
Angina Microvascular/epidemiologia , Estresse Psicológico/complicações , Análise de Variância , Estudos de Casos e Controles , Depressão/complicações , Humanos , Masculino , Pessoa de Meia-Idade , Isquemia Miocárdica/psicologia , Fatores de Risco , Fatores Socioeconômicos , Estados Unidos/epidemiologia
9.
J Psychosom Res ; 40(1): 53-8, 1996 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-8730644

RESUMO

Antiplatelet substances, generally aspirin, have become widely used for secondary prevention of ischemic heart disease. Used in relatively small doses, it is generally assumed that aspirin has no psychoactive effect. The present study took advantage of a sample of 174 males undergoing coronary angiography to see if regular aspirin use as prophylactic therapy for ischemic heart disease was associated with one or more of a number of measures of emotional distress. Aspirin use was found to be associated with less depression and anxiety or worry, as reported by the patient and as perceived by a significant other. Despite a significant association of aspirin use with the presence of documented coronary artery disease, the association of aspirin use and diminished distress could not be accounted for by the previously observed high prevalence of depressed/anxious individuals among patients with negative or nominal results on angiography, or by a number of other demographic or clinical variables such as age and socioeconomic status. Although only correlational in nature, present results raise the question of whether aspirin may have a beneficial mood-modulating effect.


Assuntos
Afeto/efeitos dos fármacos , Aspirina/farmacologia , Aspirina/uso terapêutico , Trombose Coronária/tratamento farmacológico , Inibidores de Ciclo-Oxigenase/uso terapêutico , Aspirina/administração & dosagem , Angiografia Coronária , Trombose Coronária/diagnóstico , Inibidores de Ciclo-Oxigenase/administração & dosagem , Relação Dose-Resposta a Droga , Humanos , Masculino , Pessoa de Meia-Idade , Isquemia Miocárdica/prevenção & controle
10.
J Health Psychol ; 1(1): 93-105, 1996 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22011523

RESUMO

A number of psychosocial measures were tested as correlates of coronary artery disease (CAD) in 122 males with positive coronary angiograms and 56 males with no manifest history of atherosclerotic disease who were selected to approximate the patients' age and socio economic status. Only denial of depression as indexed by spouse/friend-minus-self scores on the Ketterer Stress Symptom Frequency Checklist and number of unprovoked nocturnal awakenings were independently and positively related to CAD severity in multivariate regression analyses which controlled for jointly associated cardiac risk factors and commonly used cardiovascular medications. Denial of depression and unprovoked nocturnal awakening appear to be independent correlates of coronary artery disease.

11.
Psychosom Med ; 56(3): 232-6, 1994.
Artigo em Inglês | MEDLINE | ID: mdl-8084969

RESUMO

Previous studies have found associations between snoring, or polysomnographic documented sleep apnea, and hypertension, cerebral vascular disease, and myocardial infarction. The present study examined the relationship of coronary artery disease (CAD) and snoring. One hundred and twenty-two males with positive angiographic studies were compared with fifty-six men, matched in age and socioeconomic status, who had no known history of coronary heart, or other atherosclerotic, disease. The percentage of subjects reporting that they snore "usually" or "always/loudly" increased across the four CAD severity groupings (nonpatient controls = 19.6%, 1 vessel = 44.4%, 2 vessel = 41.9%, 3 vessel = 56.0%) with a p value of .005. Hypertension, body mass index, and pack years of smoking were found to be associated with both coronary artery disease severity and snoring. When these variables were controlled in a multiple regression analysis, the relationship of snoring and CAD severity remained significant at p = .050.


Assuntos
Doença das Coronárias/fisiopatologia , Síndromes da Apneia do Sono/fisiopatologia , Ronco/fisiopatologia , Angiografia Coronária , Doença das Coronárias/diagnóstico , Comportamento Alimentar , Humanos , Estilo de Vida , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Síndromes da Apneia do Sono/diagnóstico , Fumar/efeitos adversos
13.
Gerontologist ; 32(4): 438-43, 1992 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-1427244

RESUMO

This paper presents findings from the evaluation of a self-management education program based on self-regulation principles. Older men and women (N = 324) were randomly assigned to program and control groups. Outcomes were measured using the Sickness Impact Profile. Twelve months following baseline data collection, psychosocial functioning of program participants was significantly better than that of controls. Different program effects were noted when results were analyzed by participant gender.


Assuntos
Indicadores Básicos de Saúde , Cardiopatias/terapia , Educação de Pacientes como Assunto , Qualidade de Vida , Autocuidado , Atividades Cotidianas , Idoso , Idoso de 80 Anos ou mais , Estudos de Avaliação como Assunto , Feminino , Seguimentos , Cardiopatias/psicologia , Humanos , Masculino , Pessoa de Meia-Idade , Distribuição Aleatória , Estados Unidos
14.
J Appl Physiol (1985) ; 73(1): 260-4, 1992 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-1506378

RESUMO

A group of orthotopic heart transplant (OHT, n = 28) and heart surgery (n = 19) patients, with similar ejection fractions and left ventricular end-diastolic pressures, were exercised to symptom-limited maximum to describe differences in cardiovascular and gas exchange responses. Testing was performed at a mean of 3 and 6 mo after surgery, respectively (P less than 0.05). OHT patients have a greater resting systolic and diastolic blood pressure (P less than 0.01) and a significantly greater (P less than 0.01) heart rate (HR) at rest in the supine and standing positions and during minutes 2 through 7 of supine recovery. Peak treadmill time was significantly less (P less than 0.01) in OHT patients. No significant differences were found for systolic blood pressure (SBP) during recovery, peak HR, ventilation, relative O2 uptake (VO2), body weight, ventilatory equivalents for O2 and CO2, O2 pulse, and HR-SBP product (peak HR x peak SBP). Peak pulse pressure, heart rate reserve, total VO2, and absolute VO2 at ventilatory threshold were significantly lower (P less than 0.01) in the OHT patients. We concluded that 1) complete cardiac decentralization is evident, 2) the significantly reduced VO2 at ventilatory threshold should be considered when activities of daily living are prescribed, and 3) SBP response is more appropriate than HR for assessing recovery of the decentralized heart after maximal exercise.


Assuntos
Exercício Físico/fisiologia , Transplante de Coração/fisiologia , Hemodinâmica/fisiologia , Pressão Sanguínea/fisiologia , Dióxido de Carbono/metabolismo , Eletrocardiografia , Teste de Esforço , Frequência Cardíaca/fisiologia , Humanos , Pessoa de Meia-Idade , Consumo de Oxigênio , Período Pós-Operatório , Troca Gasosa Pulmonar
15.
J Appl Physiol (1985) ; 70(6): 2627-31, 1991 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-1885457

RESUMO

Orthotopic heart transplantation (OHT) represents an effective alternative for individuals with end-stage heart disease. The current literature reports only the responses of OHT patients to greater than or equal to 4 mo of exercise training (ET) and frequently lacks adequate controls. Most programs currently treating OHT patients usually provide 6-12 wk of ET. This study describes the effects of a 10-wk supervised ET program in 12 male OHT patients and 5 other male OHT patients who served as a comparison group. Graded exercise tests were performed before and after ET. After ET, maximal O2 consumption was significantly greater for the ET group than the comparison group (P less than 0.05) and the mean increase in peak heart rate was 18 +/- 4 and 6 +/- 4 (SE) min-1 for ET and comparison groups, respectively (P less than 0.05). Maximal ventilation was also significantly greater for the ET group at after ET, while resting heart rate and blood pressure and peak blood pressure, O2 pulse, respiratory rate, and ventilatory equivalents for O2 and CO2 were not significantly changed. We conclude that after OHT a 10-wk ET program improves maximal O2 consumption and, by improving peak heart rate, improves O2 delivery.


Assuntos
Fenômenos Fisiológicos Cardiovasculares , Terapia por Exercício , Transplante de Coração/fisiologia , Adulto , Pressão Sanguínea , Frequência Cardíaca , Humanos , Masculino , Pessoa de Meia-Idade , Consumo de Oxigênio , Troca Gasosa Pulmonar
17.
Respir Care ; 34(3): 191-5, 1989 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10315772

RESUMO

UNLABELLED: A number of mouth-to-mask ventilation devices have become commercially available in the past several years. In this study, we compared the volumes delivered by eight of these devices to the volumes delivered by mouth-to-mouth ventilation. METHOD: Fourteen respiratory care practitioners participated in the study. Ventilation was delivered to an adult resuscitation manikin. Each subject ventilated the manikin using mouth-to-mouth technique and each of the following mouth-to-mask devices: Boehringer EVA, Hospitak, Hudson, Intertech Safe Response, Laerdal Pocket Mask, Life Design Systems (LDS), Respironics SealEasy, and Vital Signs. Evaluation periods of 1 minute were used, minute ventilation and respiratory rate were measured, and tidal volume was calculated. RESULTS: There was a significant difference between the volumes delivered by the masks (p less than 0.001). The volumes delivered by each mask were less than mouth-to-mouth volumes (p less than 0.05 in each case). The mean +/- SD mouth-to-mouth volume was 1.04 +/- 0.32 L. The mean +/- SD volumes for each of the devices was 0.54 +/- 0.34 L for the EVA, 0.77 +/- 0.21 L for the Hospitak, 0.51 +/- 0.26 L for the Hudson, 0.81 +/- 0.35 L for the Safe Response, 0.65 +/- 0.25 L for the Pocket Mask, 0.82 +/- 0.27 L for the LDS, 0.79 +/- 0.32 L for the SealEasy, and 0.76 +/- 0.21 L for the Vital Signs. CONCLUSIONS: We found considerable variability between the volumes delivered with commercially available mouth-to-mask ventilation devices. Although the volumes delivered during mouth-to-mask technique were less than those delivered with mouth-to-mouth technique, the volumes delivered by some of the mouth-to-mask devices were large enough to allow them to be substituted for mouth-to-mouth technique.


Assuntos
Ressuscitação/instrumentação , Ventiladores Mecânicos/normas , Desenho de Equipamento , Estudos de Avaliação como Assunto , Máscaras/normas , Ressuscitação/métodos
18.
Pharmacol Biochem Behav ; 27(3): 569-72, 1987 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-3659082

RESUMO

Visual measures of stereotypy, margin time (thigmotaxis or wall-hugging), and center time were correlated with automated measures using a revised 16 beam version of the Digiscan Animal Activity Monitor System. Rats were injected with d-amphetamine (1.25, 2.5, 5.0 and 10.0 mg/kg), scopolamine (1.25 and 2.5 mg/kg) or saline and drugs were found to increase center time and decrease margin time in a dose-dependent manner, with the maximum effect occurring with 1.25 and 2.5 mg/kg, respectively. At higher doses, an opposite effect was observed. Extremely high correlations between visual and automated recordings of both margin time and center time were found. Since thigmotaxic or wall-hugging behavior has been used as an indicator of emotionality in rats, the results of the present study suggest that these two locomotor variables may be useful additions to the Digiscan multivariate analysis of locomotor behavior. It was also found that a redefinition of stereotypic behavior improved its correlation with visual measurements compared to earlier studies.


Assuntos
Comportamento Animal/efeitos dos fármacos , Dextroanfetamina/farmacologia , Processamento Eletrônico de Dados , Escopolamina/farmacologia , Comportamento Estereotipado/efeitos dos fármacos , Animais , Comportamento Animal/fisiologia , Relação Dose-Resposta a Droga , Masculino , Ratos , Ratos Endogâmicos , Comportamento Estereotipado/fisiologia
19.
Health Phys ; 51(5): 633-40, 1986 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-3771224

RESUMO

Wistar rats were exposed via inhalation to aerosols of 239PuO2, 244Cm oxide or a mixed Pu-Cm oxide with an activity ratio of about 1:1. Activity in lung and several extrapulmonary tissues were examined up to 120 d after exposure to determine whether calcining Pu and Cm together affected lung clearance or translocation to other sites in the body for either nuclide. Initial deposition was about 1,200 Bq (32 nCi) for 239PuO2, 4,200 Bq (115 nCi) for 244Cm, and 2,400 Bq (65 nCi) total alpha for the mixed oxide. The kinetics of single nuclides were as expected, with Pu oxide confined mainly to lung at all times and cleared with a half-time of 42 d. Curium was translocated rapidly to liver, with a peak activity of about 10% of the initial alveolar deposition at 7-14 d. Skeleton activity increased gradually, amounting to 12-15% of initial deposition near the end of the study. Lung clearance of Cm was more rapid than for Pu, with about 13% of Pu and less than 5% of Cm remaining at the end of the experiment. Both Pu and Cm remained in the lung somewhat longer when administered as a mixed oxide than the respective nuclides administered singly, and virtually all activity in the body was confined to the lung. Translocation of Cm to extrapulmonary tissues was almost entirely prevented by incorporation into the PuO2 matrix. Therefore, calcining the two radionuclides together in an aerosol altered the kinetics of both following inhalation in rats, but most dramatically for 244Cm. The resulting change in radionuclide distribution for the lung and the body following such a mixed inhalation exposure would presumably alter the long-term health effects compared to those seen with the pure compounds.


Assuntos
Cúrio/metabolismo , Pulmão/metabolismo , Óxidos/metabolismo , Plutônio/metabolismo , Aerossóis , Animais , Osso e Ossos/metabolismo , Feminino , Fígado/metabolismo , Taxa de Depuração Metabólica , Ratos , Ratos Endogâmicos
20.
Environ Res ; 36(2): 359-78, 1985 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-3872210

RESUMO

Young adult rats were exposed via inhalation or intratracheal instillation to oxides of arsenic, beryllium, cadmium, cobalt, lead, selenium, vanadium, and ytterbium. Serial necropsies were performed to assess the metal content in organs at times up to several weeks after exposure. The lung clearance varied widely for these compounds, and the times to remove 50% of the initial burden ranged from 18 min for vanadium to 400 days for beryllium. Arsenic, cadmium, lead, selenium, and vanadium were initially soluble in lung, but a small fraction (1-20%) remained there over the long term. Extrapulmonary tissues often accumulated substantial amounts of the soluble oxides, and whole-body retention was often greater for compounds that were more soluble in lung. Arsenic, selenium, and vanadium translocated to carcass and bone. Arsenic, cadmium, lead, and selenium accumulated in the liver, and the kidney retained cadmium and lead. Beryllium, cobalt and ytterbium did not deposit at any extrapulmonary site in significant amounts. In general, the aqueous solubility of these compounds was a poor predictor for behavior in vivo because of their interaction with metabolic processes. Of the metal oxides tested for acute lethality following pulmonary deposition, cadmium was most toxic, followed by selenium, vanadium, and arsenic.


Assuntos
Arsenicais , Compostos de Cádmio , Pulmão/metabolismo , Metais/metabolismo , Óxidos , Animais , Arsênio/metabolismo , Trióxido de Arsênio , Berílio/metabolismo , Transporte Biológico , Cádmio/metabolismo , Cobalto/metabolismo , Exposição Ambiental , Feminino , Chumbo/metabolismo , Taxa de Depuração Metabólica , Metais/toxicidade , Ratos , Ratos Endogâmicos , Selênio/metabolismo , Solubilidade , Distribuição Tecidual , Vanádio/metabolismo , Itérbio/metabolismo
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