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Biomedical subjects

R Demers

Publications and source records attributed to R Demers.

At least 19 recordsLinked to original sources
PubMed2001

Impact of breast carcinoma on African-American women: the Detroit experience.

BACKGROUND: National and regional population-based data have demonstrated substantially worse outcome in African-American patients with breast carcinoma when compared with white patients, as well as a younger age distribution among African-American patients with breast carcinoma. The extent to which various socioeconomic, environmental, lifestyle, and genetic factors interact to account for this ethnicity-related disparity in survival is poorly understood. Greater than one-half of the inner-city population of Detroit, Michigan is African American, and greater metropolitan Detroit has been one of the contributing registries for the Surveillance, Epidemiology, and End Results (SEER) program since its inception in 1973. The impact of breast carcinoma on African Americans in the Detroit area is therefore well documented and provides significant insight into the history, epidemiology, and biology of this major public health care problem. METHODS: A review of the medical literature published over the past 20 years regarding African-American patients with breast carcinoma was performed. The pertinent findings were summarized in the context of advances made in breast carcinoma screening, treatment, and risk reduction during that period. RESULTS: The large African-American population of Detroit is a major factor contributing to the excessive breast carcinoma mortality rate reported for this city, which is one of the highest in the United States. Improvements in early detection of breast carcinoma by using screening mammography have been apparent in the earlier stage distributions of breast carcinoma observed in both white and African-American patients; however, progress has lagged substantially for the latter group. Detroit SEER registry data also have shown a younger age distribution of African-American patients with breast carcinoma and higher rates of estrogen receptor negative tumors. Finally, preliminary data from health maintenance organizations have suggested improved breast carcinoma outcome for African Americans who possess greater socioeconomic benefits, but disparities in disease stage at presentation persist. CONCLUSIONS: The diverse Detroit community is ideally suited for breast carcinoma screening programs and clinical investigations that seek to address and overcome ethnicity-related survival disparities and barriers to health care. Findings from these studies can be correlated with results from similar projects in other geographic areas.

Black or African American↗
PubMed2001

Expanding the linear dynamic range in quantitative high performance liquid chromatography/tandem mass spectrometry by the use of multiple product ions.

A strategy for expanding the linear working range in bioanalysis using quantitative high performance liquid chromatography/tandem mass spectrometry (HPLC/MS/MS) is presented. The strategy involves monitoring multiple product ions. Herein we demonstrate the strategy on a rat plasma assay for a proprietary experimental drug where the linear range is expanded from 2 to 4 orders of magnitude. A primary sensitive ion was monitored to obtain a high sensitivity range calibration curve (0.400 to 100 ng/mL) while a less sensitive secondary ion was monitored to obtain a low sensitivity range calibration curve (90.0 to 4000 ng/mL). Each calibration curve gave acceptable linearity (r >0.990). Quality control samples at low, mid and high levels within each calibration curve demonstrated acceptable precision and accuracy (within 20% for all levels). The technique was successfully applied to rat pre-clinical sample analysis.

Animals↗
PubMed1998

Lung cancer in young patients: analysis of a Surveillance, Epidemiology, and End Results database.

PURPOSE: A large community-based cancer registry was analyzed to determine if the clinicopathologic characteristics and/or survival rates of lung cancer patients under 50 years of age at diagnosis differ from those of patients 50 years of age or greater at diagnosis. PATIENTS AND METHODS: Data regarding demographics, stage, histology, initial therapy, and survival were obtained on all patients with primary bronchogenic carcinoma registered in the metropolitan Detroit Surveillance, Epidemiology and End Results (SEER) registry from 1973 to 1992. RESULTS: Of 31,266 patients, 9.0% were under 50 years of age at diagnosis. Females (40.1% v 31.2%; P < .001) and blacks (28.7% v 21.9%, P < .001) were overrepresented in the younger group compared with the older group. Younger patients had a significantly higher incidence of adenocarcinoma and were less likely to present with local-stage disease (18.6% v 25.2%; P < .001). Younger patients were significantly more likely to undergo surgery and/or combined-modality therapy. Relative survival at 5 years was significantly better in the younger group (16.1% v 13.4%; P < .001), mainly because of better survival in patients with local-stage disease (48.7% v 35.4%; P < .001). In a multivariate analysis, advanced-stage, nonsurgical initial therapy, age 50 years or greater at diagnosis, and male gender were independent negative prognostic factors. CONCLUSION: The overrepresentation of females and blacks in the group of younger patients with lung cancer suggests an increased susceptibility to lung carcinogens in these populations. Overall, this study suggests that lung cancer is not a more aggressive disease in younger patients and that all patients with lung cancer should be managed along the same therapeutic guidelines.

Adolescent↗
PubMed1995

Effect of age and race on the survival of men with prostate cancer in the Metropolitan Detroit tricounty area, 1973 to 1987.

OBJECTIVES: Reports have demonstrated that African Americans diagnosed with prostate cancer have a poor survival compared with whites. We examined the impact of age, race, and stage of disease on survival for men diagnosed with prostate cancer. METHODS: A retrospective analysis was made of men diagnosed with prostate cancer utilizing the Surveillance, Epidemiology, and End Results Program (SEER) database. A total of 12,907 men (9339 white, 3568 black) diagnosed from January 1, 1973 through December 31, 1987 were included in the study. For each stage of disease, survival experience was examined using Kaplan-Meier and life table methods, followed by analysis using Cox's proportional hazard model. RESULTS: African-American men have a poorer survival than whites for all stages of prostate cancer when the cancer is diagnosed at younger ages. These differences in survival were not demonstrated for men diagnosed with prostate cancer after age 70. CONCLUSIONS: Age and race should be taken into account when assessing the survival of patients with prostate cancer.

Adenocarcinoma↗
PubMed1991

Overview of radon, lead and asbestos exposure.

Reducing the incidence of diseases caused by exposure to radon, lead and asbestos is a major public health challenge. Radon gas, which usually enters a home through the foundation, can cause lung cancer. Exposure to lead through paint, auto emissions and other sources can cause neurologic deficits, as well as anemia, abnormal vitamin D metabolism, nephropathy, hypertension and reproductive abnormalities. Asbestos, which is used in a vast number of products, is primarily associated with parenchymal asbestosis, pleural fibrosis, mesothelioma and lung cancer. The family physician can play a pivotal role in providing information about hazardous exposure, sources of exposure, epidemiology and disease prevention.

Adult↗
PubMed1986

New-patient no-shows in an urban family practice center: analysis and intervention.

The new-patient no-show rate reached 55 percent in an urban, university-based family practice center in mid-1981. A prospective descriptive study revealed that the no-show rates varied significantly with hour of appointment, patient age, source of referral, delay in appointment date, and chronicity of illness. Study findings led to alterations in the scheduling system, with a subsequent drop in the new-patient no-show rate to 40 percent.

Adult↗
PubMed1982

Electroconvulsive therapy and memory dysfunction: is there evidence for prolonged defects?

The authors reviewed 39 papers which concern the long-term effects of electroconvulsive therapy (ECT) on human memory. Although the authors caution that methodological considerations preclude a decisive assessment, the majority of the studies suggest that ECT does not normally produce prolonged memory defects. Some recent studies do document subtle but persistent defects several months after ECT, especially in personal autobiographical material. These defects appear to be more annoying than seriously incapacitating. Variables considered important in an ideal design of studies on ECT and memory are discussed.

Amnesia↗
PubMed1976

A multiparametric computer analysis of carcinoma of the colon.

From 1957 to 1973, 656 patients with carcinoma of the entire colon, excluding those with carcinoma of the rectum, were reviewed with the aid of a computer. Of 457 patients, 69.7 per cent were observed for a minimum of five years. Sixty-five per cent of the lesions were located in the cecum or sigmoid colon. In patients with type A lesion, the five year plus survival rate was 71.15 per cent while, in patients with type D lesions, the five year plus survival rate was zero per cent. Patients who presented with intestinal obstruction had a significantly lower five year survival rate. Roentgenographic visualization of the cecum was significantly less accurate in demonstrating carcinoma when compared with that of the sigmoid colon. An emergency surgical procedure had a significantly higher operative mortality than did elective procedures. In both groups of patients undergoing emergency and elective operations, primary resection and anastomosis led to similar operative mortality rates, although staged procedures resulted in the lowest operative mortality in both groups. In the group of patients who had elective operations, resection an primary anastomosis led to a significantly lower wound infection and fistula rate when compared with the group of patients who had emergency procedures. In comparison with other series, no improvement in survival was illustrated in patients with carcinoma of the colon. The use of new modalities of adjuvant therapy, such as radiotherapy or chemotherapy, or both, actually should be evaluated.

Adult↗
PubMed1975

Impedance phlebography: accuracy of diagnosis in deep vein thrombosis.

In an evaluation of the diagnostic accuracy of impedance phlebography for the diagnosis of deep vein thrombosis, 51 limbs in 32 patients were examined simultaneously by impedance phlebography and by venography. The impendance diagnosis and accurate in 47 limbs, erroneous in 2 and inconclusive in 2; the overall accuracy was 92%. Simultaneous clinical diagnosis yielded an accuracy of 53%. The method requires full cooperation by the patient and meticulous attention to the details of the test by the physician or technician performing the examination.

Aged↗
PubMed1975

Results of cholecystectomy in 1000 consecutive patients.

Analysis of the results of cholecystectomy in 1000 consecutive patients revealed an overall mortality of 0.6%; among patients who underwent cholecystectomy only, there were no deaths. Wound infection occurred in 3.4% of all patients but the rate exceeded 8% among those in whom another procedure was performed or there was acute cholecystitis. Cephaloridine given prophylactically was useful in decreasing the infection rate in the two latter groups. Cystic duct cholangiography, used in 193 patients, increased the rate of stone retrieval from the bile ducts from 41 to 63%, but the incidence of both false-negative and false-positive cholangiograms was disturbingly high. Exploration was performed on clinical grounds despite a normal cholangiogram in 15 patients, with 5 positive results. Common duct exploration was productive 41% of the time when clinical judgement without cholangiography was used. While cystic duct cholangiography is useful, improvements in reliability are imperative and probably feasible, in view of the results achieved in the operating room and those in departments of radiology.

Acute Disease↗