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1.
J Clin Oncol ; 10(9): 1460-9, 1992 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-1517789

RESUMO

PURPOSE: This trial evaluated the optimum dosing regimen for recombinant human granulocyte-macrophage colony-stimulating factor (rhu GM-CSF) to support a dose-intensive chemotherapy regimen given without progenitor cell replacement. PATIENTS AND METHODS: Fifty-one patients with refractory malignancy received cyclophosphamide 2,500 mg/m2 on days 1 and 2, etoposide 500 mg/m2 on days 1, 2, and 3, and cisplatin 50 mg/m2 on days 1, 2, and 3. Patients were hospitalized from cycle days 1 to 4 for chemotherapy and readmitted for cytopenic temperatures above 38.5 degrees C. Cycles were repeated every 35 days in patients who responded to a total of three cycles. GM-CSF was given at doses of 250 to 1,000 micrograms/m2 by continuous intravenous infusion (CIV) or subcutaneously starting on cycle days 3 to 6. Two nonrandomized control groups are used. RESULTS: The optimum regimen of GM-CSF for shortening the duration of leukopenia (WBC count less than 300/microL) was 500 micrograms/m2 given CIV. Duration of leukopenia was 5.9 days compared with 13.2 and 10.2 days in the controls (P less than .05). The optimum regimens for shortening duration of hospitalization, however, were 500 and 750 micrograms/m2/d given as divided (twice daily) subcutaneous injections. Durations of hospitalization were 9.6 and 9.8 days compared with 15.7 and 22.2 days in the controls (P less than .08). At the higher GM-CSF dose, only 36% of patients required readmission for cytopenic fever. Toxicities of GM-CSF at clinically useful doses were minimal. Twelve patients had complete response (24%) and 22 partial response (43%). CONCLUSIONS: This dose-intensive regimen can be given safely without progenitor replacement. rhu GM-CSF decreases the duration of severe leukopenia and decreases the need for hospitalization and antibiotic therapy.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Fator Estimulador de Colônias de Granulócitos e Macrófagos/administração & dosagem , Leucopenia/tratamento farmacológico , Neoplasias/tratamento farmacológico , Adulto , Idoso , Contagem de Células Sanguíneas , Esquema de Medicação , Avaliação de Medicamentos , Feminino , Fator Estimulador de Colônias de Granulócitos e Macrófagos/uso terapêutico , Humanos , Injeções Subcutâneas , Leucopenia/induzido quimicamente , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/uso terapêutico , Projetos de Pesquisa , Resultado do Tratamento
2.
Cancer Epidemiol Biomarkers Prev ; 7(7): 585-9, 1998 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9681526

RESUMO

A study of temporal trends in mammography screening and changes in stage of disease at diagnosis was conducted among Hispanic and non-Hispanic white female members of the Lovelace Health Plan, Flexcare Plan, and Lovelace Senior Plan/Senior Options (LHP), a managed care organization. Two-year screening rates for female members ages 50-74 years were calculated for 1989-1996. From 1989-1996, mammography screening rates for non-Hispanic white female members increased from 65.5 to 71.6%, although this was not a statistically significant increase. Screening rates for Hispanic female members also increased from 50.6 to 62.7%, but they were significantly lower than for non-Hispanic white women. All breast cancers occurring among LHP female members ages 40-74 years were also identified for this same time period. A logistic regression model adjusting for age, year of diagnosis, ethnicity, and duration of enrollment prior to diagnosis found that statistically significant predictors of more advanced stage of disease at diagnosis included young age, diagnosis after 1991 for non-Hispanic white women, and diagnosis prior to 1992 for Hispanic women. Longer duration of enrollment prior to diagnosis was predictive of lower stage of disease, but the odds ratio was not statistically significant. For the time period 1992-1996, Hispanic women with breast cancer were more than twice as likely to have advanced stage of breast cancer compared with non-Hispanic white women (odds ratio, 2.12).


Assuntos
Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/patologia , Hispânico ou Latino/estatística & dados numéricos , Mamografia , População Branca/estatística & dados numéricos , Idoso , Neoplasias da Mama/etnologia , Carcinoma in Situ/diagnóstico por imagem , Carcinoma in Situ/etnologia , Carcinoma in Situ/patologia , Feminino , Humanos , Programas de Assistência Gerenciada , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Análise de Regressão
3.
Cancer Epidemiol Biomarkers Prev ; 3(2): 113-9, 1994 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-8049632

RESUMO

To assess smoking-related and other risk factors for high-grade cervical dysplasia in southwestern Hispanic and non-Hispanic white women in New Mexico, we conducted a clinic-based case-control study among attendees at university-affiliated gynecology clinics. We collected data on cigarette use, sexual behavior, past and current sexually transmitted diseases, hygienic practices, contraception, and diet. For both ethnic groups combined, after adjustment for the effects of human papillomavirus, sexual behavior, and other risk factors, cigarette smoking at the time of diagnosis was associated with high-grade dysplasia (odds ratio, 1.7; 95% confidence limits, 1.0-2.8). In contrast, former smoking was not associated with cervical dysplasia (odds ratio 0.9; 95% confidence limits, 0.5-1.5). Analyses showed dose-response relationships for the amount of cigarettes smoked per day and for cumulative exposure (pack-years of use) in association with cervical dysplasia. Although our study lacked the power to show statistically significant ethnic differences in smoking-related risks for dysplasia, smoking at the time of diagnosis, high pack-years of use, and smoking at the time of menarche were associated with dysplasia only for non-Hispanic white versus Hispanic women. Our data support hypotheses that implicate cigarette use as an etiological factor in the development of high-grade cervical dysplasia and suggest ethnic differences in risks for dysplasia among women attending the same clinics.


Assuntos
Hispânico ou Latino , Fumar/efeitos adversos , Displasia do Colo do Útero/etiologia , População Branca , Adolescente , Adulto , Carcinoma in Situ/epidemiologia , Carcinoma in Situ/etiologia , Carcinoma de Células Escamosas/epidemiologia , Carcinoma de Células Escamosas/etiologia , Estudos de Casos e Controles , Estudos Transversais , Feminino , Hispânico ou Latino/estatística & dados numéricos , Humanos , Incidência , New Mexico/epidemiologia , Papillomaviridae , Infecções por Papillomavirus/epidemiologia , Infecções por Papillomavirus/etiologia , Fatores de Risco , Comportamento Sexual , Fumar/epidemiologia , Infecções Tumorais por Vírus/epidemiologia , Infecções Tumorais por Vírus/etiologia , Displasia do Colo do Útero/epidemiologia , Neoplasias do Colo do Útero/epidemiologia , Neoplasias do Colo do Útero/etiologia , Esfregaço Vaginal
4.
Int J Epidemiol ; 23(5): 913-22, 1994 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-7860171

RESUMO

BACKGROUND: Various contraceptive practices and reproductive factors have been associated with cervical neoplasia in case-control studies worldwide. METHODS: To investigate contraceptive and reproductive risk factors associated with high-grade cervical dysplasia in southwestern Hispanic and non-Hispanic white women, we carried out a clinic-based case-control study among university-affiliated clinic attendees. RESULTS: Oral contraceptive use ever (odds ratio [OR] = 0.4, 95% confidence interval [CI]: 0.2-0.9) and past diaphragm use (OR = 0.3, 95% CI: 0.1-0.8) were protective for dysplasia in analyses adjusted for age, ethnicity, sexual behaviour, and for cervical papillomavirus (HPV) infection. After further adjustment for Pap smear screening interval, oral contraceptive use ever remained protective for dysplasia. Vaginal deliveries were strongly associated with dysplasia with > 2 vaginal deliveries associated with a 3.9-fold increase in risk after adjustment for age, ethnicity, sexual behaviour, and HPV infection. Using logistic regression models to simultaneously control for effects of multiple factors as potentially related to cervical dysplasia, we found low educational attainment, cervical HPV infection, cigarette smoking, history of any sexually transmitted disease, and having one or more vaginal deliveries to be associated with dysplasia; oral contraceptive use and past diaphragm use also remained protective for high-grade cervical dysplasia in these regression analyses. CONCLUSIONS: The data suggest that use of oral contraceptives (ever) and past diaphragm use are protective for high-grade cervical dysplasia among Hispanic and non-Hispanic white women in New Mexico. The clinic-based perspective of this research (versus population-based studies) may help explain some of these findings.


Assuntos
Displasia do Colo do Útero/etiologia , Estudos de Casos e Controles , Dispositivos Anticoncepcionais , Anticoncepcionais Orais , Feminino , Hispânico ou Latino , Humanos , Entrevistas como Assunto , Papillomaviridae , Infecções por Papillomavirus/complicações , História Reprodutiva , Sudoeste dos Estados Unidos , Infecções Tumorais por Vírus/complicações , População Branca
5.
J Neurotrauma ; 17(8): 629-40, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10972240

RESUMO

Proton magnetic resonance spectroscopy (1H-MRS) offers a unique insight into brain cellular metabolism following traumatic brain injury (TBI). The aim of the present study was to assess change in neurometabolite markers of brain injury during the recovery period following TBI. We studied 19 TBI patients at 1.5, 3, and 6 months postinjury and 28 controls. We used 1H-MRS to quantify N-acetylaspartate (NAA), creatine (Cre), choline (Cho), and myoinositol (mIns) in occipitoparietal gray matter (GM) and white matter (WM) remote from the primary injury focus. Neuropsychological testing quantified cognitive impairment and recovery. At 1.5 months, we found cognitive impairment (mean z score = -1.36 vs. 0.18,p < 0.01), lower NAA (GM: 12.42 mM vs. 13.03, p = 0.01; WM: 11.75 vs. 12.81, p < 0.01), and elevated Cho (GM: 1.51 vs. 1.25, p < 0.01; WM: 1.98 vs. 1.79, p < 0.01) in TBI patients compared with controls. GM NAA at 1.5 months predicted cognitive function at outcome (6 months postinjury; r = 0.63, p = 0.04). GM NAA continued to fall by 0.46 mM between 1.5 and 3 months (p = 0.02) indicating continuing neuronal loss, metabolic dysfunction, or both. Between 3 and 6 months, WM NAA increased by 0.55 mM (p = 0.06) suggesting metabolic recovery. Patients with poorer outcomes had elevated mean GM Cho at 3 months postinjury, suggesting active inflammation, as compared to patients with better outcomes (p = 0.002). 1H-MRS offers a noninvasive approach to assessing neuronal injury and inflammation following TBI, and may provide unique data for patient management and assessment of therapeutic efficacy.


Assuntos
Ácido Aspártico/análogos & derivados , Lesões Encefálicas/metabolismo , Colina/metabolismo , Transtornos Cognitivos/diagnóstico , Creatinina/metabolismo , Inositol/metabolismo , Adolescente , Adulto , Idoso , Ácido Aspártico/metabolismo , Lesões Encefálicas/complicações , Transtornos Cognitivos/etiologia , Transtornos Cognitivos/metabolismo , Estudos Transversais , Feminino , Humanos , Modelos Logísticos , Espectroscopia de Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Prótons , Estatísticas não Paramétricas
6.
Acad Med ; 71(11): 1225-32, 1996 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9217511

RESUMO

BACKGROUND: The personal health experiences of medical students may contribute in important but previously unacknowledged ways to their well-being and education. This pilot study surveyed medical students about their health care needs, practices, insurance status, and concerns about seeking care. METHOD: A questionnaire was developed and distributed to 151 students at the University of New Mexico School of Medicine in 1993-94. Participant privacy was protected. Responses were compiled and analyzed using logistic regression models and odds ratios. RESULTS: A total of 112 students responded. Most reported health care needs and half routinely received care at their training institution. One-third had informally requested prescriptions or diagnostic tests from medical school faculty and housestaff; one-fourth used such informal consultation as their "usual" method of obtaining care. Eighteen students were uninsured. The students reported that they had not sought care for several reasons, and many had experienced difficulty in obtaining care. The students indicated concern about confidentiality and about the dual role as both student and patient at the training institution. They believed that their academic standing would be jeopardized if they developed certain health problems. When asked about hypothetical scenarios, a majority preferred to avoid the dual role of medical-student-patient. When asked about scenarios in which medical student peers exhibited suicidal depression or severe drug abuse, the students overwhelmingly preferred not to notify the medical school administration. Significant differences in responses were found with respect to gender and training level. CONCLUSION: This pilot study examined the health care needs, practices (including the use of informal consultation), insurance status, and concerns of students at one medical school. The findings highlight the students' perceptions of illness and vulnerability during medical school training. Constructive implications for academic medicine are discussed regarding initiatives in the areas of policy, research, and the resources and structure of student health care services.


Assuntos
Acessibilidade aos Serviços de Saúde , Necessidades e Demandas de Serviços de Saúde , Aceitação pelo Paciente de Cuidados de Saúde , Estudantes de Medicina , Adulto , Atitude Frente a Saúde , Feminino , Humanos , Seguro Saúde , Masculino , Projetos Piloto , Estudantes de Medicina/psicologia , Inquéritos e Questionários
7.
Mutat Res ; 461(4): 273-8, 2001 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-11104903

RESUMO

Defects in the repair and maintenance of DNA increase risk for cancer. X-ray cross-complementing group 1 protein (XRCC1) is involved with the repair of DNA single-strand breaks. A nucleotide substitution of guanine to adenine leading to a non-conservative amino acid change was identified in the XRCC1 gene at codon 399 (Arg/Gln). This change is associated with higher levels of aflatoxin B1-adducts and glycophorin A somatic mutations. A case-control study was conducted to test the hypothesis that the 399Gln allele is positively associated with risk for adenocarcinoma of the lung. XRCC1 genotypes were assessed at codon 399 in 172 cases of lung adenocarcinoma and 143 cancer-free controls. Two ethnic populations were represented, non-Hispanic White and Hispanic. The distribution of XRCC1 genotypes differed between cases and controls. Among cases, 47.7% were Arg/Arg, 35.5% were Arg/Gln, and 16.9% were Gln/Gln. Among controls, XRCC1 allele frequencies were 45.5% for Arg/Arg, 44.8% for Arg/Gln, and 9.8% for Gln/Gln. Logistic regression analysis was used to assess the association between lung adenocarcinoma and the G/G genotype relative to the A/A or A/G genotypes. In non-Hispanic White participants, the lung cancer risk associated with the G/G genotype increased significantly after adjustment for age (OR=2.81; 95% CI, 1.2-7.9; P=0.03) and increased further after adjustment for smoking (OR=3.25; 95% CI, 1.2-10.7; P=0.03). Among all groups, a significant association was found between the G/G homozygote and lung cancer (OR=2.45; 95% CI, 1.1-5.8; P=0.03) after adjustment for age, ethnicity, and smoking. This study links a functional polymorphism in the critical repair gene XRCC1 to risk for adenocarcinoma of the lung.


Assuntos
Adenocarcinoma/genética , Proteínas de Ligação a DNA/genética , Neoplasias Pulmonares/genética , Adenocarcinoma/etnologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Alelos , Frequência do Gene , Marcadores Genéticos/genética , Predisposição Genética para Doença , Glutamina/genética , Humanos , Neoplasias Pulmonares/etnologia , Pessoa de Meia-Idade , Fatores de Risco , Proteína 1 Complementadora Cruzada de Reparo de Raio-X
8.
J Dev Behav Pediatr ; 16(4): 211-9, 1995 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-7593654

RESUMO

When, as commonly occurs, a parent's and child's reports about the child differ, the lack of agreement usually leads to consideration of which information is objective and valid. Little attention has been given to understanding what meaning these differences might have in the context of parent-child relationships or to whether the existence or absence of these differences might be causally related to the child's psychosocial status and functioning. Third- through fifth-grade children (N = 178) in behavior disorder and regular classrooms were asked to complete a self-concept measure; parents were asked to independently complete the same instrument as they thought their child would. Parents of children without behavior disorders were significantly more accurate in their descriptions of their children's perceptions than were parents of children with behavior problems. They also tended to expect their children to have more positive self-concepts than the children actually reported. Parents who are able to accurately report their children's feelings and who err toward more positive assessments may be preventing behavior problems.


Assuntos
Pais , Autoimagem , Autoavaliação (Psicologia) , Criança , Comportamento Infantil , Transtornos do Comportamento Infantil/diagnóstico , Transtornos do Comportamento Infantil/psicologia , Feminino , Humanos , Masculino , Poder Familiar , Apoio Social
9.
Ann Otol Rhinol Laryngol ; 102(8 Pt 1): 631-8, 1993 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-8352489

RESUMO

Sources of variability in nasal airway resistance measured by posterior rhinomanometry were studied in 5 subjects tested on 5 different days and 56 subjects tested on 2 different days. On each day, a questionnaire on upper airway health and nasal symptoms was completed. The mean individual difference in nasal airway resistance between the 2 test days in the group of 56 subjects was 5.3% (SD 52.7%). Between-subject variability accounted for 74.9% and 72.5% of the total variability in the group of 5 and the group of 56 subjects, respectively. For the 5 subjects, by accounting for a change in upper airway symptoms or upper respiratory tract infection that occurred over the 5 test days, there was a significant decrease in the between-subject variability. The difference in sources of variation due to a change in upper airway symptoms was not seen in the group of 56 subjects. We conclude that the largest source of variability in nasal airway resistance is due to between-subject differences.


Assuntos
Resistência das Vias Respiratórias/fisiologia , Obstrução Nasal/diagnóstico , Adulto , Análise de Variância , Feminino , Humanos , Masculino , Manometria/métodos , Obstrução Nasal/epidemiologia , Reprodutibilidade dos Testes , Testes de Função Respiratória/métodos , Testes de Função Respiratória/estatística & dados numéricos , Fatores de Tempo
10.
Health Phys ; 65(3): 234-51, 1993 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8244693

RESUMO

Although radon exposure is an established cause of lung cancer among underground miners, the lung cancer risk to the general population from indoor radon remains controversial. This controversy stems in part from the contradictory results of published studies of indoor radon and lung cancer, including 15 ecologic studies, seven of which found a positive association, six no association, and two a negative association. To address the misunderstanding of the indoor radon risk that has resulted from these ecologic studies, the authors discuss the general methodologic problems and limitations of ecologic studies, and the particular limitations of these 15 studies. The authors conclude that the shortcomings of the ecologic studies render them uninformative on the lung cancer risk associated with indoor radon.


Assuntos
Poluentes Radioativos do Ar/efeitos adversos , Poluição do Ar em Ambientes Fechados/efeitos adversos , Neoplasias Pulmonares/etiologia , Neoplasias Induzidas por Radiação , Radônio/efeitos adversos , Ecologia , Humanos
11.
Arch Environ Health ; 52(2): 118-23, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9124871

RESUMO

The route of breathing, oral or nasal, is a determinant of the doses of inhaled pollutants delivered to target sites in the upper and lower respiratory tracts. We measured partitioning of ventilation, using a divided oronasal mask during a submaximal exercise test, in 37 male and female subjects who ranged in age from 7 to 72 y. The following four patterns of breathing were evident during exercise: (1) nasal only (13.5%), nasal shifting to oronasal (40.5%), oronasal only (40.5%), and oral only (5.4%). Children (i.e., 7-16 y of age) displayed more variability than adults with respect to their patterns of ventilation with exercise. Young adults (i.e., 17-30 y of age) who initially breathed nasally with exercise switched to oral ventilation at a lower percentage of the previously measured maximum ventilation (10.8%) than older subjects (31.8%). The partitioning of ventilation between the nasal and oral routes follows complex patterns that cannot be predicted readily by the age, gender, or nasal airway resistance of the subject.


Assuntos
Envelhecimento/fisiologia , Respiração Bucal/fisiopatologia , Nariz/fisiologia , Respiração/fisiologia , Adolescente , Adulto , Idoso , Resistência das Vias Respiratórias , Criança , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Respiração com Pressão Positiva/instrumentação , Testes de Função Respiratória/métodos , Testes de Função Respiratória/estatística & dados numéricos
13.
Br J Cancer ; 96(8): 1278-83, 2007 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-17406356

RESUMO

The use of 5-methylcytosine demethylating agents in conjunction with inhibitors of histone deacetylation may offer a new therapeutic strategy for lung cancer. Monitoring the efficacy of gene demethylating treatment directly within the tumour may be difficult due to tumour location. This study determined the positive and negative predictive values of sputum and serum for detecting gene methylation in primary lung cancer. A panel of eight genes was evaluated by comparing methylation detected in the primary tumour biopsy to serum and sputum obtained from 72 patients with Stage III lung cancer. The prevalence for methylation of the eight genes in sputum (21-43%) approximated to that seen in tumours, but was 0.7-4.3-fold greater than detected in serum. Sputum was superior to serum in classifying the methylation status of genes in the tumour biopsy. The positive predictive value of the top four genes (p16, DAPK, PAX5 beta, and GATA5) was 44-72% with a negative predictive value for these genes > or =70%. The highest specificity was seen for the p16 gene, and this was associated with a odds ratio of six for methylation in the tumour when this gene was methylated in sputum. In contrast, for serum, the individual sensitivity for all genes was 6-27%. Evaluating the combined effect of methylation of at least one of the four most significant genes in sputum increased the positive predictive value to 86%. These studies demonstrate that sputum can be used effectively as a surrogate for tumour tissue to predict the methylation status of advanced lung cancer where biopsy is not feasible.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/genética , Metilação de DNA , Neoplasias Pulmonares/genética , Regiões Promotoras Genéticas , Escarro/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma Pulmonar de Células não Pequenas/sangue , Feminino , Humanos , Neoplasias Pulmonares/sangue , Masculino , Pessoa de Meia-Idade , Escarro/citologia
14.
Kidney Int ; 70(10): 1858-65, 2006 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17021609

RESUMO

Intravenous vitamin D is standard therapy for secondary hyperparathyroidism in hemodialysis (HD) patients. In for-profit dialysis clinics, mortality was higher for patients on calcitriol compared to paricalcitol. Doxercalciferol, a second vitamin D2 analog, is currently available. We assessed mortality associated with each vitamin D analog and with lack of vitamin D therapy in patients who began HD at Dialysis Clinic Inc. (DCI), a not-for-profit dialysis provider. During the 1999-2004 study period we studied 7731 patients (calcitriol: n=3212; paricalcitol: n=2087; doxercalciferol: n=2432). Median follow-up was 37 weeks. Mortality rates (deaths/100 patient-years) were identical in patients on doxercalciferol (15.4, 95% confidence interval (13.6-17.1)) and paricalcitol (15.3 (13.6-16.9)) and higher in patients on calcitriol (19.6 (18.2-21.1)) (P<0.0001). In all models mortality was similar for paricalcitol versus doxercalciferol (hazard ratios=1.0). In unadjusted models, mortality was lower in patients on doxercalciferol (0.80 (0.66, 0.96)) and paricalcitol (0.79 (0.68, 0.92)) versus calcitriol (P<0.05). In adjusted models, this difference was not statistically significant. In all models mortality was higher for patients who did not receive vitamin D versus those who did (1.2 (1.1-1.3)). Mortality in doxercalciferol- and paricalcitol-treated patients was virtually identical. Differences in survival between vitamin D2 and D3 may be smaller than previously reported.


Assuntos
Conservadores da Densidade Óssea/uso terapêutico , Calcitriol/uso terapêutico , Ergocalciferóis/uso terapêutico , Hiperparatireoidismo Secundário/tratamento farmacológico , Diálise Renal/mortalidade , Vitamina D/análogos & derivados , Adulto , Idoso , Idoso de 80 Anos ou mais , Doenças Ósseas Metabólicas/sangue , Cálcio/sangue , Feminino , Humanos , Hiperparatireoidismo Secundário/mortalidade , Falência Renal Crônica/complicações , Falência Renal Crônica/terapia , Masculino , Pessoa de Meia-Idade , Hormônio Paratireóideo/sangue , Fósforo/sangue , Diálise Renal/efeitos adversos , Estudos Retrospectivos , Fatores de Risco , Análise de Sobrevida
15.
Am J Epidemiol ; 139(3): 312-22, 1994 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-8116607

RESUMO

Ecologic regression studies conducted to assess the cancer risk of indoor radon to the general population are subject to methodological limitations, and they have given seemingly contradictory results. The authors use simulations to examine the effects of two major methodological problems that affect these studies: measurement error and misspecification of the risk model. In a simulation study of the effect of measurement error caused by the sampling process used to estimate radon exposure for a geographic unit, both the effect of radon and the standard error of the effect estimate were underestimated, with greater bias for smaller sample sizes. In another simulation study, which addressed the consequences of uncontrolled confounding by cigarette smoking, even small negative correlations between county geometric mean annual radon exposure and the proportion of smokers resulted in negative average estimates of the radon effect. A third study considered consequences of using simple linear ecologic models when the true underlying model relation between lung cancer and radon exposure is nonlinear. These examples quantify potential biases and demonstrate the limitations of estimating risks from ecologic studies of lung cancer and indoor radon.


Assuntos
Exposição Ambiental , Neoplasias Pulmonares/induzido quimicamente , Neoplasias Pulmonares/epidemiologia , Vigilância da População , Radônio/efeitos adversos , Análise de Regressão , Projetos de Pesquisa , Viés , Fatores de Confusão Epidemiológicos , Ecologia , Humanos , Modelos Lineares , Fatores de Risco , Estudos de Amostragem , Fumar/efeitos adversos
16.
Am Rev Respir Dis ; 148(2): 435-40, 1993 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-8342909

RESUMO

Although cigarette yields of tar and nicotine have been declining since the early 1970s, little information is available for the general population on the consequences of their use on exposure to tobacco combustion products. In a population-based sample of 298 smokers, the majority of whom were Hispanic, we examined the relationships between yields of cigarettes currently smoked and levels of salivary cotinine and end-expired carbon monoxide. Spearman correlation coefficients between the current number of cigarettes smoked and cotinine (r = 0.52) or carbon monoxide (r = 0.51) were higher than correlations between the Federal Trade Commission (FTC) nicotine data and these same markers, 0.12 and 0.05, respectively. Correlations between FTC tar and carbon monoxide yields and the biologic markers were similarly weak. In multiple linear regression models, the current number of cigarettes smoked was the most important predictor of cotinine and carbon monoxide levels (p < 0.0001). The addition of FTC tar, nicotine, or carbon monoxide to the models explained little of the variability in cotinine or carbon monoxide levels. Because FTC yields of tar and nicotine are poor predictors of exposure to tobacco combustion products, subjects' reports of cigarette brand should not be used as a primary marker of exposure in epidemiologic investigations. Furthermore, smokers need to be advised about the limitations of cigarette yield information for predicting the potential for adverse health effects of smoking.


Assuntos
Biomarcadores/análise , Monóxido de Carbono/metabolismo , Nicotiana/química , Nicotina/análise , Plantas Tóxicas , Respiração , Saliva/química , Fumar/metabolismo , Alcatrões/análise , Adulto , Fatores Etários , Etnicidade , Feminino , Previsões , Hispânico ou Latino , Humanos , Masculino , Pessoa de Meia-Idade , New Mexico , Respiração/fisiologia , Fatores Sexuais , Fumaça
17.
Magn Reson Med ; 41(1): 193-7, 1999 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10025629

RESUMO

The current study sought to investigate the reproducibility of a quantitative spectroscopic examination, using rigorous positioning guidelines and automated spectral fitting for measuring the cerebral metabolites N-acetylaspartate (NAA), creatine (Cre), choline (Cho), and myo-inositol (ml). Ten subjects were studied in three sessions to determine the variability associated with measurement of metabolites in normal-appearing occipitoparietal white matter, using short echo STEAM spectroscopy. A careful relocalization protocol based on local landmarks identified on thin-slice images was used. No changes in mean metabolite concentrations for each subject between sessions were found, confirming relocalization. Mean coefficients of variation in measurement of NAA, Cre, Cho, and ml were 3.30, 4.33, 5.30, and 8.10, respectively. These data suggest that changes in metabolite concentrations as small as 12% can be confidently discerned in an individual subject over time. The implication of these results to study design is discussed.


Assuntos
Ácido Aspártico/análogos & derivados , Encéfalo/metabolismo , Colina/metabolismo , Creatina/metabolismo , Inositol/metabolismo , Espectroscopia de Ressonância Magnética , Adulto , Ácido Aspártico/metabolismo , Feminino , Seguimentos , Humanos , Masculino , Prótons , Reprodutibilidade dos Testes
18.
Antimicrob Agents Chemother ; 35(5): 944-7, 1991 May.
Artigo em Inglês | MEDLINE | ID: mdl-1854175

RESUMO

We retrospectively analyzed amikacin pharmacokinetics in 28 patients (mean age, 47.4 +/- 13.6 years) who received high-dose chemotherapy during a neutropenic febrile episode. Patients received an experimental protocol of high-dose anticancer chemotherapy. Amikacin pharmacokinetic parameters were calculated from two or more concentrations in serum around a single dose by the method of Sawchuck and Zaske (J. Pharmacokinet. Biopharm. 4:183-195, 1976). Predicted parameters were calculated by using standard methods. The observed amikacin volume of distribution and clearance were significantly greater and the elimination half-life was longer than predicted (0.38 +/- 0.13 versus 0.25 liter/kg [P = 0.0001], 1.51 +/- 0.92 versus 1.17 +/- 0.38 liters/h/kg [P = 0.012], and 3.8 +/- 2.4 versus 2.9 +/- 1.1 h [P = 0.011], respectively). Multivariate analysis revealed that albumin correlated negatively and creatinine correlated positively with the volume of distribution and the elimination half-life. Creatinine and the percentage below the ideal body weight correlated negatively and hematocrit correlated positively with clearance. Administration of dosage regimens based on predicted pharmacokinetic parameters yielded subtherapeutic amikacin concentrations in serum in our patients. Because of the increased dosage requirements and the need for adequate antibiotic treatment in this population, we suggest guidelines for empiric dosing for patients with advanced cancer receiving intensive chemotherapy.


Assuntos
Amicacina/farmacocinética , Antineoplásicos/efeitos adversos , Neoplasias/metabolismo , Adolescente , Adulto , Idoso , Análise de Variância , Antineoplásicos/uso terapêutico , Peso Corporal , Feminino , Meia-Vida , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias/tratamento farmacológico , Neutropenia/complicações , Análise de Regressão
19.
Stroke ; 29(11): 2254-60, 1998 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9804631

RESUMO

BACKGROUND AND PURPOSE: To determine the neurometabolic patterns of brain injury in systemic lupus erythematosus with antiphospholipid antibody syndrome (SLE-aPLS). METHODS: Forty-nine SLE patients (12 SLE-aPLS) and 23 control subjects were studied using magnetic resonance imaging and spectroscopy. N-Acetylaspartate/creatine (NAA/Cre) and choline/Cre (Cho/Cre) were measured in normal-appearing tissue. IgG and IgM antiphospholipid antibodies (aPL) were measured by enzyme-linked immunosorbent assay. RESULTS: Stroke, epilepsy, and elevated IgG-aPL were more common in SLE-aPLS patients than in SLE patients (P<0.001). NAA/Cre was lower (P<0.05) and Cho/Cre higher (P<0.001) in SLE-aPLS patients than in SLE patients without aPLS. Regression models showed NAA/Cre was most related to injury seen by imaging (P<0.01), disease duration (P<0. 05), and prior neuropsychiatric SLE (NPSLE) (P=0.07). Reduced NAA/Cre was more closely related to IgG-aPL (P<0.01) than the presence of stroke or aPLS. When adjusted for all factors, Cho/Cre was most associated with the presence of aPLS (P=0.05). CONCLUSIONS: SLE and SLE-aPLS are actually a clinical continuum describing brain injury in SLE, with SLE-aPLS being characterized by increased aPL, NPSLE, stroke, epilepsy, and disturbed neurochemistry. An elevated IgG-aPL level is a potent risk factor for brain injury as measured by NAA/Cre in SLE that is independent of stroke and aPLS. However, thrombotic phenomena and the presence of aPL (aPLS) are most closely associated with increased Cho/Cre in SLE. These results suggest that aPLs exacerbate SLE, resulting in increased thrombotic and nonthrombotic brain injuries. Spectroscopy detects brain injury in SLE and may permit better understanding of the neurological consequences of SLE and SLE-aPLS.


Assuntos
Síndrome Antifosfolipídica/metabolismo , Ácido Aspártico/análogos & derivados , Encefalopatias/metabolismo , Lúpus Eritematoso Sistêmico/metabolismo , Adulto , Síndrome Antifosfolipídica/complicações , Síndrome Antifosfolipídica/imunologia , Ácido Aspártico/análise , Ácido Aspártico/metabolismo , Biomarcadores , Química Encefálica/imunologia , Encefalopatias/diagnóstico , Encefalopatias/etiologia , Infarto Cerebral/etiologia , Infarto Cerebral/metabolismo , Feminino , Humanos , Modelos Lineares , Lúpus Eritematoso Sistêmico/complicações , Lúpus Eritematoso Sistêmico/imunologia , Imageamento por Ressonância Magnética , Espectroscopia de Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Prótons
20.
Cancer ; 91(9): 1716-23, 2001 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-11335896

RESUMO

BACKGROUND: In spite of the effectiveness of mammography screening for early detection of breast carcinoma, the use of screening mammography varies widely across racial and ethnic groups. Recently, concerns have been raised about the potential adverse effect a benign breast biopsy may have on subsequent mammography utilization, including subsequent use among minority women. METHODS: Computerized health care claims data for 1991 through 1997 from a managed care organization were used to compare mammography use among Hispanic and non-Hispanic women who had had a mammogram followed by an incisional or excisional benign breast biopsy to women who had had a mammogram and no biopsy. Through survival analysis methods, the time-to-next mammogram was compared among these three groups. RESULTS: The sample included 693 (3.2%) and 289 (1.3%) women who had had a mammogram followed by an incisional biopsy or an excisional biopsy, respectively, and 20,540 (95.4%) women who had had a mammogram and no biopsy. Both Hispanic and non-Hispanic women with a biopsy returned sooner for subsequent mammograms than women without a biopsy (P < 0.0001). Hispanic women without a biopsy returned later than non-Hispanic women without a biopsy (P < 0.0001). However, Hispanic women with an excisional biopsy returned sooner than non-Hispanic women (P < 0.05). CONCLUSIONS: Within a managed care organization, both Hispanic and non-Hispanic women who had had a mammogram followed by a benign breast biopsy returned sooner for a subsequent mammogram than women who had had a mammogram and no biopsy. However, ethnic differences in time-to-next mammogram were observed for women without a biopsy and those with an excisional biopsy. Hispanic women without a biopsy returned later for a subsequent mammogram than non-Hispanic women in similar groups, but those with an excisional biopsy returned sooner.


Assuntos
Neoplasias da Mama/patologia , Adulto , Distribuição por Idade , Idoso , Biópsia , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/etnologia , Feminino , Hispânico ou Latino , Humanos , Mamografia , Programas de Rastreamento , Pessoa de Meia-Idade , Modelos Estatísticos
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