RESUMO
Granular activated carbon treatment with postchlorination (GAC/Cl2) and chlorination followed by chloramination (Cl2/NH2Cl) represent two options for utilities to reduce DBP formation in drinking water. To compare the total cytotoxicity of waters treated by a pilot-scale GAC treatment system with postchlorination (and in some instances with prechlorination upstream of GAC (i.e., (Cl2)/GAC/Cl2)) and chlorination/chloramination (Cl2/NH2Cl) at ambient and elevated Br- and I- levels and at three different GAC ages, we applied the Chinese hamster ovary (CHO) cell cytotoxicity assay to whole-water extracts in conjunction with calculations of the cytotoxicity contributed by the 33 (semi)volatile DBPs lost during extractions. At both ambient and elevated Br- and I- levels, GAC/Cl2 and Cl2/NH2Cl achieved comparable reductions in the formation of regulated trihalomethanes (THMs) and haloacetic acids (HAAs). Nonetheless, GAC/Cl2 always resulted in lower total cytotoxicity than Cl2/NH2Cl, even at up to 65% total organic carbon breakthrough. Prechlorination formed (semi)volatile DBPs that were removed by the GAC, yet there was no substantial difference in total cytotoxicity between Cl2/GAC/Cl2 and GAC/Cl2. The poorly characterized fraction of DBPs captured by the bioassay dominated the total cytotoxicity when the source water contained ambient levels of Br- and I-. When the water was spiked with Br- and I-, the known, unregulated (semi)volatile DBPs and the uncharacterized fraction of DBPs were comparable contributors to total cytotoxicity; the contributions of regulated THMs and HAAs were comparatively minor.
Assuntos
Água Potável , Animais , Cricetinae , Halogenação , Carvão Vegetal , Células CHO , Cricetulus , TrialometanosRESUMO
Lung cancer remains the leading cause of death worldwide. Because many patients with non-small cell lung cancer are elderly and have multiple comorbid conditions, many with potentially curable disease are unfit to undergo definitive surgical resection. Stereotactic body radiation therapy (SBRT) is increasingly being used to treat patients with medically inoperable stage I non-small cell lung cancer. SBRT combines reproducible and accurate anatomic targeting with the delivery of a very high dose per fraction of radiation to a target. Planning and delivery of SBRT is a coordinated effort between the radiation oncology team and consulting services. Clinical outcomes, toxicity profiles, treatment delivery, and indications for SBRT are reviewed. Services currently billed during planning and treatment of SBRT are detailed. This article introduces to consulting specialists and subspecialists a new Current Procedural Terminology code that has been proposed to more accurately reflect work performed during SBRT by these consulting providers. This code is described, and its implications for patient care are discussed.
Assuntos
Neoplasias Pulmonares/cirurgia , Radiocirurgia/métodos , Codificação Clínica , Humanos , Neoplasias Pulmonares/epidemiologia , Neoplasias Pulmonares/patologia , Estadiamento de Neoplasias , Radiocirurgia/efeitos adversos , Taxa de Sobrevida , Estados Unidos/epidemiologiaRESUMO
RESEARCH OBJECTIVE: Estimates of the prevalence of major depression vary widely. Current estimates range from 2 to 14 % depending upon the definition and procedure for diagnosis. Further, most estimates are for special populations, either living in selected geographic areas or receiving specific types of medical care. A national survey of Medicare Fee-for-Service (FFS) beneficiaries provides an opportunity to assess the current level of major depression or dysthymia among a diverse population of older Americans. STUDY DESIGN: The Health Outcomes Survey (HOS) was administered to a national random sample of 1,000 Medicare FFS beneficiaries. We used the Mental Component Summary (MCS) measure of the SF-36 to estimate the prevalence of major depression or dysthymia. Logistic regression was used to examine associated factors. RESULTS: The response rate was 61.7%. Using an MCS score of 42 or lower, prevalence of major depression or dysthymia was estimated to be 25% for respondents age 65 years and older. Logistic regression analysis revealed that the likelihood of major depression or dysthymia was associated with years of education (Odds Ratio (OR) = 0.87), difficulties performing activities of daily living (OR = 1.72), and Medicaid enrollment (OR = 2.67). CONCLUSIONS: The results revealed that one-quarter of the respondents reported mental health problems consistent with major depression or dysthymia. This is higher than previously reported. Like previous studies, years of education, physical impairment, and poverty are strong predictors of major depression or dysthymia. The high rate of major depression or dysthymia implies there may be considerable unmet need among elderly Medicare FFS beneficiaries for diagnosing and treating mental illness.