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Biomedical subjects

M E Whitcomb

Publications and source records attributed to M E Whitcomb.

18 recordsLinked to original sources
PubMed1992

Comparing the characteristics of schools that produce high percentages and low percentages of primary care physicians.

To examine whether the medical school environment is important in influencing students to choose careers in primary care, the authors in 1991 compared certain characteristics of the environments of schools that produced high percentages of primary care physicians with those of schools that produced low percentages over a five-year period. The authors used the American Medical Association Physician Masterfile to identify the percentage of graduates of each of 121 medical schools for the period 1981-1985 who entered primary care specialties. They then compared the 25 schools that produced low percentages (22-29%) with the 25 schools that produced high percentages (39-56%). The results demonstrate important differences between the two groups of schools in their commitments to primary care education, their research programs, and their clinical environments supporting required clerkships. The authors conclude that a school's educational environment is an important factor in influencing some students to pursue careers in primary care medicine.

Career Choice↗
PubMed1979

Characterization of antibody-dependent cytotoxicity mediated by human alveolar macrophages.

Antibody-dependent cellular cytotoxicity is believed to be an important host defense mechanism. Although this reaction has been shown to be mediated by various Fc receptor-bearing effector cells, the ability of a mature macrophage population to mediate this reaction has not been previously demonstrated. In this study, alveolar macrophages obtained from normal subjects by subsegmental lung lavage were used to determine whether this mature macrophage population had the ability to mediate antibody-dependent cell killing. The results of this study demonstrated that alveolar macrophages clearly mediate antibody-dependent cellular cytotoxicity against antibody-coated erythrocyte targets and that the kinetics of the reaction are characteristic of an enzyme-substrate interaction. Furthermore, this study demonstrated that alveolar macrophages are more efficient at mediating antibody-dependent cytotoxicity than is their precursor cell, the peripheral blood monocyte.

Adult↗
PubMed1978

Pleural effusion as a manifestation of Dressler's syndrome in the distant post-infection period.

A 65-year-old woman developed a bloody pleural effusion 2-1/2 years after the onset of Dressler's syndrome. Since an extensive evaluation failed to reveal a specific etiology, the effusion was presumed to be a manifestation of Dressler's syndrome. Because of the therapeutic implications involved, we are reporting this case to emphasize that pleural effusions may occur as a manifestation of Dressler's Syndrome in the distant post-infarction period.

Aged↗
PubMed1978

The effects of corticosteroid administration on the bronchoalveolar cells obtained from guinea pigs by lung lavage.

The effects of systemic administration of corticosteroids on the bronchoalveolar cell population obtained from guinea pigs by lung lavage were studied. The results of this study demonstrate that in contrast to the marked decrease in the percentage of T lymphocytes in the peripheral blood of animals treated with steroids, there was no significant decrease in the percentage of T lymphocytes in the bronchoalveolar cell population. In addition, corticosteroid administration did not significantly affect either the number of alveolar macrophages obtained by lavage or the Fc receptor activity of these cells. When considered in the context of previously reported data, these results emphasize that caution must be used in reaching conclusions about the integrity of the pulmonary immune response from the results of studies using a bronchoalveolar cell population obtained by lung lavage. This observation must be considered when evaluating the significance of studies of the human pulmonary immune response performed with cells obtained by segmental bronchopulmonary lavage.

Animals↗
PubMed1978

Identification of a receptor for complement on the guinea pig alveolar macrophage membrane.

The present study was undertaken in an attempt to demonstrate the presence of a receptor for complement on the membrane of guinea pig alveolar macrophages (PAM). When target cells were prepared using mouse serum as the complement source, no attachment or ingestion of the target cell by guinea pig PAM was observed. When fresh autologous guinea pig serum was used as the complement source, attachment and ingestion of the target cell by PAM were observed. The results of additional experiments demonstrated that the attachment of these target cells was mediated by a complement receptor. These results demonstrated that like human PAM, guinea pig PAM do possess a membrane receptor for complement.

Animals↗
PubMed1978

Drug-induced lung disease.

Since there are no diagnostic studies to confirm the presence of a drug-induced lung reaction the physician will make a correct diagnosis only if he is aware of the drugs which have been identified to cause pulmonary reactions and their specific manifestations. Failure to recognize a drug-induced lung disease can lead to significant morbidity and in some cases mortality. The major drug-induced lung diseases are reviewed, the drugs being presented in the context of their clinical use and the reactions on the basis of common pathogenetic mechanisms.

Adult↗
PubMed1977

Abnormal lymphocyte protein synthesis in bronchogenic carcinoma.

Phytohemagglutinin (PHA) stimulated lymphocyte protein synthesis was measured in vitro in 21 patients with recently diagnosed, untreated bronchogenic carcinoma and 11 control subjects. In the cancer group absolute protein synthesis was significantly decreased in both baseline and stimulated cultures. The abnormality in protein synthesis was observed despite the fact that there were no differences in vitro DNA synthesis between the two groups. In order to investigate the possibility that a decrease in the number of T-cells was the cause of the impaired protein synthesis in the lung cancer patients, the percentage of circulating E-rosetting forming cells was measured. The mean percentage of rosette forming cells in the cancer patients was 66.8 +/- 2.2 and in the control population was 68.3 +/- 2.6. Our results demonstrate that lymphocyte protein synthesis is abnormal in patients with bronchogenic carcinoma and that the abnormality in protein synthesis is not due to decreased numbers of T-cells. In addition our results suggest that measurement of protein synthesis is a more sensitive assay of lymphocyte function than other standard parameters of cellular immunity.

Adult↗
PubMed1977

Clinical and roentgenographic spectrum of pulmonary tuberculosis in the adult.

In order to define the roentgenographic manifestations of pulmonary tuberculosis in the adult, we reviewed a 12 month experience with newly diagnosed patients with active pulmonary tuberculosis in two Boston hospitals. Of 88 patients, 30 (34 per cent) presented with roentgenographic manifestations other than those associated with "usual" postprimary disease. At least 12 patients (13.5 per cent) had primary tuberculosis, including two subjects over 60 years of age. Six patients (6.8 per cent) had disease confined to the lower lung fields, eight patients (9 per cent) had tuberculomas and four (4.5 per cent) had miliary tuberculosis. Twenty per cent of the patients were totally asymptomatic. With the shift of tuberculosis care to community hospitals, knowledge of the varied roentgenographic manifestations is of increasing importance for the practicing internist.

Adult↗
PubMed1976

Indications for mediastinoscopy in bronchogenic carcinoma.

In an attempt to formulate indications for mediastinoscopy, the histologic tumor type and the radiographic manifestations of the tumor were correlated with the occurrence of mediastinal node metastases in 121 patients who had potentially resectable bronchogenic carcinoma. Our results demonstrated that mediastinal metastases occur commonly in patients with central lesions irrespective of cell type, but that the histologic tumor type has a definite influence on the frequency of mediastinal involvement in patients with parenchymal masses or peripheral lesions. Our results also demonstrated that the absence of radiographic evidence of mediastinal involvement cannot be given strong consideration when selecting patients for mediastinoscopy, because almost 50 per cent of patients with mediastinal involvement did not have mediastinal widening on the chest roentgenogram. Our results, in conjunction with currently accepted principles governing the management of patients with bronchogenic carcinoma, have allowed us to propose a logical approach for the use of mediastinoscopy in the prethoracotomy evaluation of patients with potentially resectable lung cancer.

Carcinoma, Bronchogenic↗
PubMed1975

Endobronchial metastasis.

An attempt was made to define the incidence of tumor metastasis to central bronchi that could clinically mimic primary bronchogenic carcinoma. In a retrospective review of 1,359 consecutive autopsies at Walter Reed General Hospital, metastatic involvement of a major airway was present in only 2% of patients who died with solid tumors. The most common extrathoracic tumors associated with metastatic involvement of a central airway are renal and colorectal carcinomas. The clinical and roentogenographic features of endobronchial metastasis and bronchogenic carcinoma were found to be indistinguishable. However, in the majority of cases the primary tumor site is clinically apparent before symptoms of endobronchial metastasis. In most cases of endobronchial metastasis, the histologic appearance of the bronchoscopic biopsy suggests the correct diagnosis. A central bronchogenic carcinoma should rarely be confused with a metastasis to a major airway from an extrathoracic source.

Adenocarcinoma↗
PubMedDate not supplied

Which medical schools produce rural physicians?

OBJECTIVE: To examine the hypothesis that medical schools vary systematically and predictably in the proportion of their graduates who enter rural practice. DESIGN: The December 1991 version of the American Medical Association Physician Masterfile was used to examine the rural and urban practice locations of physicians who graduated from American medical schools between 1976 and 1985. Selected characteristics of the medical schools--including location, ownership, and funding--were linked to the Physician Masterfile. MAIN OUTCOME MEASURES: The percentage of the graduates from each medical school who were practicing in rural areas in December 1991, disaggregated by physician specialty. RESULTS: Of the practicing graduates from our study, 12.6% were located in rural counties; family physicians were much more likely than members of other specialties to select rural practice, particularly in the smallest and most isolated rural counties. Women were much less likely than men to enter rural practice. Medical schools varied greatly in the percentage of their graduates who entered rural practice, ranging from 41.2% to 2.3% of the graduating classes studied. Twelve medical schools accounted for over one quarter of the physicians entering rural practice in this time period. Four variables were strongly associated with a tendency to produce rural graduates: location in a rural state, public ownership, production of family physicians, and smaller amounts of funding from the National Institutes of Health. DISCUSSION: The organization, location, and mission of medical schools is closely related to the propensity of their graduates to select rural practice. Increasing policy coordination among medical schools and state and federal governmental entities would most effectively address residual problems of rural physician shortages.

Career Choice↗