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Biomedical subjects

R C Davidson

Publications and source records attributed to R C Davidson.

At least 19 recordsLinked to original sources
PubMed1995

Trend analysis of changes in family practice residency graduates' practice characteristics and comparison with recent graduates.

BACKGROUND AND OBJECTIVES: Graduate follow-up studies provide medical educators with important evaluation information and insight into graduates' practices. This study compares early practice choices of two cohorts of family practice residents who graduated a decade apart. The earlier cohort's changes in practice characteristics over a 10-year period were also analyzed. METHODS: Using a mailed survey, graduates of the University of California-Davis Family Practice Residency Network have been periodically surveyed since 1978. Using data from these surveys, early practice choices of the two cohorts were compared. In addition, the responses of the earlier cohort were tracked over time to determine whether any early practice patterns still existed. RESULTS: Significant differences in the early practice choices of the two cohorts of graduates were found in the areas of practice organization, use of mid-level practitioners, perception of need for primary care physicians, and inclusion of pregnancy care in practice. A significantly lower percentage of recent graduates had entered private practice, compared with the earlier cohort (37% vs 50%, P = .02). Recent graduates were more likely to perceive a need for primary care physicians. Finally, the early practice choice differences between the two cohorts had all but disappeared 10 years later as the earlier cohort's practices had changed to resemble more closely those of the recent graduates. CONCLUSIONS: This study concludes that the practices of both established family physicians and recent graduates are changing. Residency faculty must understand how these changes influence the skill and knowledge needs of their future graduates and should design practice management curricula accordingly.

California↗
PubMed1994

Trends in maternity care by graduates and the effect of an intervention.

BACKGROUND AND OBJECTIVES: Only 24% of family physicians in the United States deliver babies, a figure that declined remarkably during the decade of the 1980s. This study examines the content of practice, with regard to maternity care, of graduates of the University of California, Davis Family Practice Residency Network over the past 20 years, and the effectiveness of residency training intervention designed to increase maternity care activity among graduates. METHODS: Using a mailed survey instrument, graduates of the UC Davis Family Practice Residency Network have been periodically surveyed on practice characteristics since 1978. Using data from these surveys, maternity care and other practice characteristics of all graduates were analyzed using descriptive statistics. Data on trends in maternity care of two groups of residents who graduated a decade apart were evaluated. A separate evaluation of the two most recent graduating classes was performed to evaluate an intervention at the Network's university-based program. The program had been designed to increase the number of graduates who provide maternity care. RESULTS: Survey responses from previous graduates of the six network programs showed that only 31% included maternity care in their practices at the time of the 1991 survey. Sixty-one percent of a cohort of graduates from a 3-year period from 1979 through 1981 included maternity care upon entering practice. The 3-year cohort of residents graduating a decade later, during the years 1988-1990, had an initial participation rate in maternity care of only 37% in 1991. However, only 11% of the graduates from the university-based program in the 1988-1990 cohort made an initial decision to include maternity care in their practice. For the graduates of this program from 1991 and 1992, a period following the specific intervention, participation in maternity care increased to 50%. CONCLUSIONS: This study documents the decrease in interest in providing obstetrical services by recent family practice residency graduates when compared to graduates a decade earlier. Further, it suggests that residency programs, even with very low rates of participation in maternity care, can increase the interest and participation of residents to include these services in their practices after graduation.

California↗
PubMed1993

Increased cytosolic free calcium in red blood cells is associated with essential hypertension in humans.

Intracellular free calcium (Cai2+) was measured in human red blood cells (RBCs) using the Ca(2+)-sensitive fluorescent probe, fluo-3. Fresh RBCs were loaded with the acetoxymethyl ester of fluo-3 (fluo-3-AM) in vitro. Following incubation at 37 degrees C for 60 min, cells were separated from nonincorporated fluo-3-AM and fluo-3. Fluorescence was quantified with excitation and emission wavelengths of 506 nm and 526 nm, respectively. The relatively long wavelength characteristics of fluo-3 avoid much of the interference from hemoglobin that makes agents such as quin-2 and fura-2 of limited value in RBCs. A protocol with corrections for quenching and for extracellular fluo-3 was employed for each sample. Cai2+ in red blood cells from 15 normotensive volunteers averaged 134 +/- 12 nmol/L. In RBCs from 30 hypertensive patients who were not treated pharmacologically, Cai2+ was 317 +/- 32 nmol/L (P < .05). In a group of 27 hypertensives who were treated with various drugs, RBC Cai2+ was 221 +/- 27 nmol/L. Measurements were also performed in RBCs from 16 patients before and at least 2 weeks following treatment with one or more antihypertensive agents. Reduction of RBC Cai2+ from 342 +/- 47 to 252 +/- 39 (P < .001) was observed in 16 patients whose blood pressure fell with treatment. Overall, there was a correlation between RBC Cai2+ and diastolic blood pressure (r = 0.413, P < .01, d.f. = 71). Thus, the present results confirm an association between elevated RBC Ca2+ and essential hypertension.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Malignant fibrous histiocytoma of the pulmonary vein with prolapse through the mitral valve orifice.

We present the case of a 33 year old white woman with malignant fibrous histiocytoma arising from the pulmonary vein and prolapsing through the mitral valve, causing acute heart failure. The patient underwent emergency cardiothoracic surgery with resection of the tumour while on cardiopulmonary bypass. The patient's heart failure improved immediately following the resection, demonstrating the benefit of palliative surgery. Adjuvant chemotherapy was recommended and the patient did well for 18 months of follow-up.

Acute Disease↗
PubMed1991

College health services in California.

College health services are an underrecognized segment of California's health delivery system. Higher education institutions in California vary in their arrangements for the provision of health services. Some of the smaller institutions provide nurse triage, first aid, and referral only, whereas other institutions provide 24-hour-per-day/7-day-per-week comprehensive ambulatory and inpatient services. More than 200 full-time equivalent physicians are employed in college health services in California. Patient profiles served by college health services targeted the traditional college student age range. Some institutions, however, have expanded their services to include nonstudent university employees and their dependents. Comparing numbers of outpatient visits and professional staffing requirements to student enrollment showed significant variability between institutions, depending upon the scope of services provided (basic, intermediate, comprehensive) and the type of student population (residential, commuter, mixed).

Adult↗
PubMed1990

Retinal ischemia and cell proliferation in the rat: the role of soluble mitogens.

Temporary retinal ischemia in the rat leads to a proliferation of endothelial cells and glial cells. We tested the hypothesis that this proliferation is caused by a release of soluble mitogens from the ischemic retina. Conditioned media were prepared from normal rat retina and from retina that had undergone 2 h ischemia and 48 h reperfusion, at which time it showed intense mitotic activity. The conditioned media were placed in cultures of fibroblasts, bovine adrenal capillary endothelial cells, and rat brain astrocytes. Cell proliferation in vitro was stimulated by the retinal extracts in all cell cultures. However, the cell proliferation in cultures with conditioned media from normal retina was similar to that in cultures with conditioned media from ischemic and proliferating retina. Although these data are consistent with the presence of soluble growth factors in the retina, they also indicate that release of these growth factors into the surrounding milieu after transient retinal ischemia is not altered to a degree that would explain the dramatic increase in mitosis.

Animals↗
PubMed1990

Hypertension following erythropoietin therapy in anemic hemodialysis patients.

Recombinant human erythropoietin (rHuEpo) corrects the anemia of end-stage renal disease. However, hypertension has been observed as an adverse effect of increasing red cell mass. In our study, 44 of 63 patients (70%) treated with rHuEpo had an increase in mean arterial pressure greater than 10 mm Hg or required new or additional hypertensive medications. Retrospective analysis disclosed that increasing blood pressure was associated with pretreatment hematocrit level less than or equal to 0.20 (P = .05) and dependency on red cell transfusions (P less than .01). Factors not associated with hypertension included the rate of rise of the hematocrit, the net rise in hematocrit, age, sex, the number of years on dialysis, the presence or absence of kidneys, smoking, or the presence of pretreatment hypertension. Noninvasive hemodynamic studies in eight normotensive patients before and after improvement of the anemia demonstrated a normalization of the decreased peripheral vascular resistance and a reduction toward normal in the elevated cardiac output. In three of these patients, clinical hypertension subsequently evolved. Follow-up hemodynamic studies in nine other patients receiving new or additional antihypertensive medications were difficult to interpret. Although the hypertension can be controlled with routine medication, hypertensive encephalopathy may occur if the blood pressure increases rapidly when the hematocrit increases with rHuEpo therapy.

Adult↗
PubMed1990

College health services as a site for ambulatory care training of residents and medical students.

The education of residents and medical students in ambulatory care settings continues to play a greater role in medical education than was the case even a few years ago. This report documents the use of college health services, commonly called student health centers, at California institutions of higher education, as training sites for residents and medical students in 1988. Directors of residency programs that had used student health centers for their residents reported that they were pleased with the association. The directors of student health centers that had had residents on educational rotations also reported a high level of overall satisfaction. Student health centers represent an untapped resource, as only 20% of such centers in California were being used to train residents at the time of this study.

Attitude of Health Personnel↗
PubMed1990

Ethics, jurisprudence, and economics in the medical school curriculum.

Medical ethics, medical jurisprudence, and medical economics are recognized as important components of a medical school curriculum. These subjects were introduced through a course given at the University of California, Davis, School of Medicine. Four aspects of the format and content of the course were instrumental to its success. Teaching principles of medical ethics within the context of jurisprudence and economics permitted the students to gain an understanding of the institutions and processes that act as positive and negative constraints on physicians' clinical and professional behavior. The course was offered during the fourth year following required clinical rotations so that all aspects of the course could be based on the clinical experiences of the students. It was presented in a continuing medical education format away from the normal teaching environment of first- and second-year classrooms and third-year clerkships. Finally, the course was designed by a multidisciplinary, multidepartmental planning group that included students.

Bioethical Issues↗
PubMed1989

Local hypothermia protects the retina from ischemia. A quantitative study in the rat.

We developed a quantitative histologic method for assessing injury in the rat retina due to transient ischemia. We used this technique to test the effectiveness of local hypothermia and allopurinol, an inhibitor of oxygen-free radical formation, in reducing ischemia/reperfusion injury in the rat retina. Retinal ischemia and reperfusion was produced by transient ligation of the optic nerve. Histologic evaluation by a masked observer was based on the average count of nonpyknotic nuclei in the inner nuclear layer of the retina from eight high power fields (X100) in one 5 microns thick sagital section at or near the optic nerve. A sharp increase in tissue damage occurs between 90 and 120 min of ischemia. Ischemia for periods of 60 and 90 min produced mild damage while periods of 120 and 240 min produced severe damage. Hypothermia protected the retina significantly from 120 min of ischemic injury (P less than 0.001 student t-test, compared to 120 min control), while allopurinol had no protective effect.

Allopurinol↗
PubMed1987

The distribution of services to the underserved. A comparison of minority and majority medical graduates in California.

We assessed the belief that minority physicians are more likely to serve traditionally underserved minority populations by examining the medical practice profiles of minority and majority physicians who graduated from seven California medical schools in 1974 and 1975. The results indicate that minority graduates are more likely to locate their practices in areas with health care personnel shortages (53%) than are majority graduates (26%). Minority physicians had a higher proportion of Medicaid or Medi-Cal patients, and they saw a greater percentage of minority patients (60%) than did majority physicians (21%). We conclude that minority graduates of US medical schools, at least those from California, serve traditionally underserved populations to a greater degree than do their majority graduate colleagues. These findings lend strong support to the contention that aggressive affirmative action programs by medical school admission committees serve the important utility function of improving the distribution of medical services.

California↗
PubMed1986

Family physicians and the future of fee-for-service payment plans.

The mechanisms by which health care providers in the United States are reimbursed for their services are undergoing dynamic and rapid changes. Traditional fee-for-service payment schemes as the predominant reimbursement methods are declining and are being supplanted by a plethora of different schemes that incorporate prepayment as the mode of compensation for service. A number of trends over the past decade predict that this transference to prepayment will continue in the future and will have a profound impact on the future practice of family medicine. It is important for family medicine educators and practicing family physicians to understand these market forces and trends so they will be better able to alter their training programs and future practices to meet future needs.

Capitation Fee↗
PubMed1986

Primary care physician satisfaction with case management.

Primary care case management is frequently proposed as one mechanism to reduce the overall cost of health services. This concept places a utilization control function upon primary care physicians who, under primary care case management, must approve all patient access to specialty physician services and hospital services. This utilization control function, often called the gatekeeper role, places new responsibilities on primary care physicians. In this study we surveyed primary care physician attitudes regarding their role as case managers.

Attitude of Health Personnel↗
PubMed1985

Oral nifedipine for the treatment of patients with severe hypertension.

Ten mg of nifedipine was administered to 19 patients with severe hypertension (mean blood pressure 187 +/- 17/122 +/- 12 mm Hg) without intensive care monitoring. Patients were instructed to bite and swallow the contents of the capsule. Blood pressure declined significantly to a mean of 149 +/- 17/92 +/- 10 mm Hg. No adverse side effects or hypotension occurred. Ten patients required an additional dose 30 to 60 minutes after the initial dose. Mean heart rate increased from 79 to 95 beats per minute without symptomatic consequences. Laboratory parameters measured before and after the four-hour study did not change significantly, although peripheral renin activity rose transiently. Urinary sodium excretion increased 43 percent over four hours after therapy in three patients in whom it was measured. Cardiac output, which was measured noninvasively in seven patients, rose nonsignificantly whereas systemic vascular resistance declined from 2,070 dynes/second/cm-5 to 1,271 dynes/second/cm-5 (statistically significant difference) in 20 minutes. These results indicate that oral nifedipine, when bitten and swallowed, effectively lowers blood pressure in patients with severe hypertension without the occurrence of adverse side effects or hypotension. Oral nifedipine may be used safely in an outpatient setting when urgent intervention is required.

Administration, Oral↗