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Biomedical subjects

Robert Smith

Publications and source records attributed to Robert Smith.

48 records · Page 3Linked to original sources
PubMed2002

What are obstructive sleep apnea patients being treated for prior to this diagnosis?

BACKGROUND: Patients with obstructive sleep apnea syndrome (OSAS) use health-care resources at higher rates than control subjects for years prior to diagnosis. Although obesity and certain cardiovascular disorders are more common in OSAS patients, the precise cause of increased health-care utilization is unclear. OBJECTIVES: To examine the causes of increased utilization, and what patients with OSAS were being treated for prior to this diagnosis. METHODS: We compared the records of 773 patients with OSAS to those of age-, gender-, geographic-, and physician-matched control subjects from the general population. RESULTS: We found that sleep apnea patients used 23 to 50% more resources (defined by physician fees, physician visits, and hospital nights) in the 5 years prior to diagnosis than did control subjects. We examined the diagnoses made and found that apnea patients are at higher risk for hypertension (odds ratio [OR], 2.5; 95% confidence interval [CI], 2.0 to 3.3), congestive heart failure (OR, 3.9; 95% CI, 1.7 to 8.9), cardiac arrhythmias (OR, 2.2; 95% CI, 1.2 to 4.0), cardiovascular disease (OR, 2.6; 95% CI, 2.0 to 3.3), chronic obstructive airways disease (OR, 1.6; 95% CI, 1.2 to 2.0), and depression (OR, 1.4; 95% CI, 1.0 to 1.9). To control for the confounding effects of obesity and to determine the independent effects of body mass index (BMI), gender, age, degree of hypoxemia, apnea-hypopnea index, and sleepiness in the 773 patients, we performed a logistic regression analysis with the dependent variable being diagnosis, and a linear regression analysis with the dependent variable being measures of health-care utilization. Age and BMI were significant independent predictors of most cardiovascular diagnoses and arthropathy. Male gender predicted ischemic heart disease (OR, 2.98; 95% CI, 1.36 to 6.54), and female gender was predictive of chronic obstructive airways disease (OR, 2.63; 95% CI, 1.85 to 3.72) and depression (OR, 2.24; 95% CI, 1.45 to 3.44). The best model predicting health-care utilization measures was comprised of age, gender, and BMI, and explained 9%, 14%, and 8% of the variability in physician fees, number of physician claims, and number of physician visits, respectively. CONCLUSION: Of all comorbid diagnoses, significantly increased utilization was found for cardiovascular disease and especially hypertension in the OSAS patients.

Adult↗
PubMed2002

Darbepoetin alfa: potential role in managing anemia in cancer patients.

Anemia in cancer patients is frequent but often under-recognized and under-treated. This may be related to misconceptions about the impact of anemia on cancer patients and ill-defined guidelines for treatment, as well as the inadequacies of current therapy. Darbepoetin alfa, a novel erythropoiesis-stimulating protein with a longer serum half-life than epoetin (alpha and beta), is approved to treat anemia in patients with chronic kidney disease. Most recently darbepoetin alfa has received approval by the FDA in USA for the treatment of anemia associated with myelosuppressive chemotherapy and approval in the EU is expected soon. Clinical trials in cancer patients indicate that darbepoetin alfa effectively and safely alleviates anemia in patients receiving chemotherapy. A Phase II trial also indicates that darbepoetin alfa is effective in patients who are not receiving chemotherapy. Thus, darbepoetin alfa has the potential to improve supportive care and thereby, cancer patients' quality of life, and might also impact on treatment outcome.

Anemia↗
PubMed1999

High-Dose Chemotherapy with Peripheral Blood Stem Cell Support for Operable Locally Advanced Noninflammatory Carcinoma of the Breast.

The purpose of this study was to determine outcomes for patients with operable noninflammatory stage IIIA/B locally advanced breast cancer (LABC) with positive axillary lymph nodes receiving high-dose chemotherapy (HDC) with peripheral blood stem cell (PBSC) support. One hundred fifteen patients with LABC who were no evidence of disease (NED) after initial surgery received standard dose induction chemotherapy, chemotherapy for mobilization of PBSC, and high-dose cyclophosphamide, thiotepa, and carboplatin with PBSC support for adjuvant therapy. Following hematopoietic recovery, all patients were scheduled to receive radiation therapy and tamoxifen was administered if the primary tumor was estrogen receptor/progesterone receptor (ER/PR) positive. Eighty-eight percent of patients were admitted to the hospital following HDC for a median of 11 days (range 3-26) and 12% were treated entirely as outpatients. There was one treatment-related death (0.9%) from infection occurring on day 8 after HDC. Forty-four (38%) have relapsed at a median of 20 months (range 10-55) from diagnosis, 11 (10%) with local-regional and 33 (28%) with metastatic disease. The probabilities of overall (OS) and event-free survival (EFS) for all 115 patients at 3 years were 0.73 and 0.61, respectively, with a median follow-up of 42 months (range 10-89) from diagnosis. In univariate and multivariate analyses, no factors could be identified that were statistically predictive for OS or EFS. However, there were trends for patients with ER/PR-negative primary tumors to have worse OS (p = 0.16) and EFS (p = 0.10) than patients with ER/PR-positive tumors. This adjuvant combined modality strategy incorporating HDC is safe and compares favorably to historical studies of neoadjuvant or adjuvant treatment for LABC. Further attempts to improve outcomes of patients with LABC receiving HDC are warranted.

Journal Article↗
PubMed1984

Moods that predict coming migraine headaches.

The relationship between mood change and migraine headache has often been reported anecdotally, but these observations have not been followed up empirically. In this study 17 migraine sufferers recorded headache occurrence and intensity using 10 mood indicators 3 times daily for periods ranging from 21 to 75 days. Headaches were correlated with mood states during the headache and for periods ranging from 12 to 36 h prior to the headache. Feelings of constraint and fatigue produced the highest correlations with headaches. The ability to predict migraine episodes from mood changes offers possibilities for controlling headaches and lessening their impact on patients' lives.

Adult↗
PubMedDate not supplied

Chain melting temperature estimation for phosphatidyl cholines by quantum mechanically derived quantitative structure property relationships.

Geometries for 62 phosphatidylcholines (PC) were optimized using the AM1 semiempirical quantum mechanical method. Results obtained from these calculations were used to calculate 463 descriptors for each molecule. Quantitative Structure Property Relationships (QSPR) were developed from these descriptors to predict chain melting temperatures (Tm) for the 41 PCs in the training set. After screening each QSPR for statistical validity, the Tm values predicted by each statistically valid QSPR were compared to corresponding Tm values extracted from the literature. The most predictive, chemically meaningful QSPR provided Tm values which agreed with literature values to within experimental error. This QSPR was used to predict Tm values for the remaining 21 PCs to provide external validation for the model. These values also agreed with literature values to within experimental error. The descriptor developed by the final QSPR was the second order average information content, a topological information-theoretical descriptor.

Calorimetry, Differential Scanning↗
PubMedDate not supplied

Fibrothorax and severe lung restriction secondary to lupus pleuritis and its successful treatment by pleurectomy.

Pleural disease is a common pulmonary manifestation of systemic lupus erythematosus (SLE) that usually responds to corticosteroids and other immunosuppressive agents. In the present report, a new approach, pleural decortication, was used in a patient with medically refractory chronic pleuritis secondary to severe SLE. A 26-year-old woman with known SLE developed progressive dyspnea and pleuritic chest pain over several months. The other systemic manifestations of her lupus were controlled with cyclophosphamide and prednisone. A computed tomography scan revealed a persistent, small, loculated right pleural effusion; pleural thickening; and atelectasis of the right middle and lower lobes. Pulmonary function tests showed a severe restrictive defect. The patient was disabled by her severe dyspnea despite maximal medical therapy, and, therefore, surgery was considered. A right thoracotomy revealed entrapment of the right lung by dense visceral pleura. Decortication was performed. On pathology, pleuritis with vascular pleural adhesions was found. No lupus pneumonitis was noted. Postoperatively, a significant clinical improvement in dyspnea was evident within several weeks. On a 6 min walk test, the patient achieved 384 m with a Borg dyspnea scale rating of 2 compared with 220 m and a Borg dyspnea scale rating of 4 preoperatively. Her forced vital capacity improved from 24% predicted to 47% predicted, and her total lung capacity improved from 35% predicted to 54% predicted. Medical therapy of systemic lupus erythematosus has been proven to be effective in controlling pleuritis in most cases. However, in the event of refractory pleuritis or pleural thickening, decortication may be a viable alternative.

Adult↗
PubMedDate not supplied

Trends in breast cancer by race and ethnicity.

In this article, the American Cancer Society (ACS) describes trends in incidence, mortality, and survival rates of female breast cancer in the United States by race and ethnicity. It also provides estimates of new cases and deaths and shows trends in screening mammography. The incidence and survival data derive from the National Cancer Institute's Surveillance, Epidemiology, and End Results program; mortality data are from the National Center for Health Statistics. Approximately 211,300 new cases of invasive breast cancer, 55,700 in situ cases, and 39,800 deaths are expected to occur among women in the United States in 2003. Breast cancer incidence rates have increased among women of all races combined and white women since the early 1980s. The increasing rate in white women predominantly involves small (< or = 2 cm) and localized-stage tumors, although a small increase in the incidence of regional-stage tumors and those larger than five cm occurred since the early 1990s. The incidence rate among African American women stabilized during the 1990s for all breast cancers and for localized tumors. African American women are more likely than white women to be diagnosed with large tumors and distant-stage disease. Other racial and ethnic groups have lower incidence rates than do either white or African American women. However, the proportion of disease diagnosed at advanced stage and with larger tumor size in all minorities is greater than in white persons. Death rates decreased by 2.5% per year among white women since 1990 and by 1% per year among African American women since 1991. The disparity in mortality rates between white and African American women increased progressively between 1980 and 2000, so that by 2000 the age-standardized death rate was 32% higher in African Americans. Clinicians should be aware that 63% and 29% of breast cancers are diagnosed at local- and regional-stage disease, for which the five-year relative survival rates are 97% and 79%, respectively. This information, coupled with decreasing mortality rates and improvements in treatment, may motivate women to have regular mammographic and clinical breast examinations. Continued efforts are needed to increase the availability of high-quality mammography and treatment to all segments of the population.

Adult↗
PubMedDate not supplied

Clinical breast examination: practical recommendations for optimizing performance and reporting.

Clinical breast examination (CBE) seeks to detect breast abnormalities or evaluate patient reports of symptoms to find palpable breast cancers at an earlier stage of progression. Treatment options for earlier-stage cancers are generally more numerous, include less toxic alternatives, and are usually more effective than treatments for later-stage cancers. For average-risk women aged 40 and younger, earlier detection of palpable tumors identified by CBE can lead to earlier therapy. After age 40, when mammography is recommended, CBE is regarded as an adjunct to mammography. Recent debate, however, has questioned the contributions of CBE to the detection of breast cancer in asymptomatic women and particularly to improved survival and reduced mortality rates. Clinicians remain widely divided about the level of evidence supporting CBE and their confidence in the examination. Yet, CBE is practiced extensively in the United States and continues to be recommended by many leading health organizations. It is in this context that this report provides a brief review of evidence for CBE's role in the earlier detection of breast cancer, highlights current practice issues, and presents recommendations that, when implemented, could contribute to greater standardization of the practice and reporting of CBE. These recommendations may also lead to improved evidence of the nature and extent of CBE's contribution to the earlier detection of breast cancer.

Breast Diseases↗
PubMedDate not supplied

Trends in breast cancer by race and ethnicity: update 2006.

In this article, the American Cancer Society (ACS) provides estimates of new breast cancer cases and deaths in 2006 and describes trends in incidence, mortality, and survival for female breast cancer in the United States. These estimates are based on incidence data from the National Cancer Institute (NCI) and the North American Association of Central Cancer Registries, which includes state data from NCI and the National Program of Cancer Registries of the Centers for Disease Control and Prevention and mortality data from the National Center for Health Statistics for the most recent years available (1975 to 2002). This article also shows trends in screening mammography. Approximately 212,920 new cases of invasive breast cancer, 61,980 in situ cases, and 40,970 deaths are expected to occur among US women in 2006. As previously reported, breast cancer incidence rates increased rapidly among women of all races from 1980 to 1987, a period when there was increasing uptake of mammography by a growing proportion of US women, and then continued to increase, but at a much slower rate, from 1987 to 2002. Trends in incidence vary by age, race, socioeconomic status, and stage. The continuing increase in incidence (all stages combined) is limited to White women age 50 and older; recent trends are stable for African American women age 50 and older and White women under age 50 years and are decreasing for African American women under age 50 years. Although incidence rates (all races combined) are substantially higher for women age 50 and older (375.0 per 100,000 females) compared with women younger than 50 years (42.5 per 100,000 females), approximately 23% of breast cancers are diagnosed in women younger than 50 years because those women represent 73% of the female population. For women age 35 and younger, age-specific incidence rates are slightly higher among African Americans compared with Whites but then cross over so that Whites have substantially higher incidence at all later ages. Among women of all races and ages, breast cancer mortality rates declined at an average rate of 2.3% per year between 1990 and 2002, a trend that reflects progress in both early detection and treatment. However, death rates in African American women remain 37% higher than in Whites, despite lower incidence rates. Although, in national surveys, approximately 70% of women age 40 years and older report having had a mammogram in the past 2 years, rates vary by race/ethnicity and are markedly lower among women with lower levels of education, without health insurance, and in recent immigrants. Furthermore, a recent study suggests that the true percentage of women having regular mammography is lower than reported in survey data. Encouraging patients age 40 years and older to have annual mammography and clinical breast exam is the single most important step that clinicians can take to reduce suffering and death from breast cancer. Clinicians should also ensure that patients at high risk of breast cancer are identified and offered appropriate referrals and treatment. Continued progress in the control of breast cancer will require sustained and increased efforts to provide high-quality screening, diagnosis, and treatment to all segments of the population.

Adult↗