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Biomedical subjects

T B Bradley

Publications and source records attributed to T B Bradley.

At least 19 recordsLinked to original sources
PubMed1994

Is geriatrics a primary care or subspecialty discipline?

OBJECTIVE: To determine how much of the clinical care provided to older persons by geriatricians is primary versus consultative. DESIGN: National Survey. PARTICIPANTS: Candidates for the 1988 certifying examination in geriatrics, physicians who expressed interest in the examination but did not register for the examination, and physicians who expressed no interest in the examination (comparison group physicians). RESULTS: Based on a 72% response rate, 78% of the care rendered by certified internal medicine geriatricians and 90% of the care rendered by certified family practice geriatricians to older persons was primary care. Internal medicine geriatricians spent a greater percentage of their care of older persons providing primary care compared with internists with no interest in geriatrics. Although internist geriatricians who were formally trained or had additional subspecialty certification provided less of their care as primary care compared with geriatricians who had no formal training, the majority of care (approximately 70%) provided by each of these two subgroups was primary care. CONCLUSIONS: The vast majority of care provided to older persons by geriatricians is primary care, and these physicians should be considered as generalists for health policy and educational purposes.

Adult↗
PubMed1993

The critical shortage of geriatrics faculty.

To estimate the adequacy of current and future supply of geriatrics faculty, we conducted a national survey to determine the current supply of geriatrics faculty in five specialties and compared these estimates to standards for optimal faculty supply in geriatrics. Finally, we generated a model to project future faculty supply based on both current training capacity and differing assumptions regarding future training capacity. Our findings indicate that the current supply of geriatrics physician faculty is less than half the number needed in each specialty. (Existing numbers range from a high of 909 faculty in internal medicine to a low of 86 in physical medicine.) Moreover, given the current capacity for training, there will be a net loss of such faculty each year in each specialty. We conclude that the number of geriatrics faculty currently available is insufficient to provide an appropriate "core" level of geriatrics training for all undergraduate medical students and residents in relevant residency programs. In addition, the current training capacity for geriatrics faculty cannot even sustain the current level of faculty over the next 10 years. To correct the current and future deficit, substantial increases in both geriatrics fellowship positions and mid-career training positions will be necessary.

Career Mobility↗
PubMed1993

Projecting the need for physicians to care for older persons: effects of changes in demography, utilization patterns, and physician productivity.

OBJECTIVE: To determine the influence of differing assumptions of population growth, visit rates, prevalence of functional impairment, physician productivity, and hospitalization rates on projected need for physicians to provide medical care for older persons. DESIGN: Sensitivity analysis of a manpower model. MAIN RESULTS: The factors that appear to have the most impact on projections of physician need are related to physician productivity, especially delegation to mid-level providers, and case-mix. Other factors, such as the variability of census projections and per capita visit rates, are likely to have less effect on overall physician supply needs. CONCLUSIONS: Although case mix and delegation to mid-level providers may both substantially affect the need for physician supply to care for older persons, only the latter can be directly affected by health policy decisions. Consideration should be given to increasing the supply of mid-level providers and providing incentives for patients and physicians to receive and provide care in delivery systems that utilize mid-level providers extensively.

Activities of Daily Living↗
PubMed1993

How many physicians will be needed to provide medical care for older persons? Physician manpower needs for the twenty-first century.

To estimate the number of full-time-equivalent (FTE) physicians and geriatricians needed to provide medical care in the years 2000 to 2030, we developed utilization-based models of need for non-surgical physicians and need for geriatricians. Based on projected utilization, the number of FTE physicians required to care for the elderly will increase two- or threefold over the next 40 years. Alternate economic scenarios have very little effect on estimates of FTE physicians needed but exert large effects on the projected number of FTE geriatricians needed. We conclude that during the years 2000 to 2030, population growth will be the major factor determining the number of physicians needed to provide medicare care; economic forces will have a greater influence on the number of geriatricians needed.

Activities of Daily Living↗
PubMed1992

Contributions of case mix and intensity change to hospital cost increases.

The 28-percent change in average Medicare inpatient cost per case between 1984 and 1987 is decomposed into three components: input price inflation, changes in average cost within diagnosis-related groups (DRGs) (intensity), and changes in the distribution of cases across DRGs (case mix). We estimate the contributions of technology diffusion and outpatient shifts to within-DRG and across-DRG cost changes. We also use California data to estimate the contribution of changes in the quantity of services provided during a stay. The factors examined account for approximately 80 percent of the real increase in average cost per case.

California↗
PubMed1991

Geriatrics faculty in the United States: who are they and what are they doing?

Despite increases in geriatrics training at all levels of medical education, there is a nationwide shortage of geriatrics faculty. This shortage may be due in part to demands for clinical responsibilities that preclude adequate time for teaching and research. To learn about the professional activities of geriatrics faculty, we conducted a national survey of a 50% sample of all medical schools and their affiliated residency programs that focused on physician and non-physician geriatrics faculty in internal medicine, family practice, psychiatry, neurology, and physical medicine and rehabilitation. Although we found minor differences across specialties, in general, approximately one-third of physician faculty time is spent in teaching, the majority of which is clinical teaching. Less than 15% of physician faculty time is spent in research, and fewer than 10% of physician geriatrics faculty devote over half of their time to research. The percentage of time that non-physician faculty (other than "Research Only" faculty) spend in research is only slightly higher. These findings suggest that efforts to increase geriatrics education at all levels and promote research advances will be limited unless geriatricians devote substantially more of their time to these responsibilities.

Clinical Medicine↗
PubMed1990

Candidates for the Certificate of Added Qualifications in Geriatric Medicine. Who, why, and when?

We surveyed physicians who took the examination for certification for Added Qualifications in Geriatric Medicine, physicians who only inquired about the examination, and physicians who expressed no interest in the examination to learn about practice characteristics of those who took the examination and their reasons for taking it. Based on a 72% response rate, we were able to demonstrate that those who took the examination took care of an older population of patients and disproportionately more of the oldest-old. These physicians were more likely to report the care of older people to be a professional focus and, in internal medicine, were more likely to have had formal training in geriatrics. Their reasons for taking the examination were primarily to obtain credentials but also frequently to improve their ability to care for older people. Nearly two-thirds of those who had inquired about the exam but did not take it in 1988 plan to do so at a later date.

Certification↗
PubMed1983

Remediation of cognitive deficits: a critical appraisal of the Feuerstein model.

It has been reported that the Instrumental Enrichment (IE) programme can successfully modify the cognitive structures of retarded disadvantaged adolescents. The research from both Israeli and American studies was reviewed to determine how strongly those claims for success were supported. Though the research yielded some statistically significant results in favour of the Instrumental Enrichment group, the importance of those findings are challenged on the grounds of research design, the relatively unimportant magnitude of mean differences that are reported as significant, and the failure of score changes on measures of cognitive ability to be reflected in school performance. It is concluded that claims that research leads 'substantial support' to the effectiveness of the IE programme must be rejected.

Achievement↗
PubMed1981

Novel studies on a "silent" high affinity mutant hemoglobin (San Diego, beta 109 Val replaced by Met).

A patient with a "silent" mutant hemoglobin characterized by high oxygen affinity and erythrocytosis is described. A novel approach was used to identify the mutant chain. Functionally active alpha and beta chains were prepared from hemolysates of the patient and a normal control. Hybrid tetramers of patient's beta chain were prepared. Functional studies revealed that the patient's beta chains had a higher oxygen affinity (P50, 1.1 torr) than normal beta chains (P50, 1.7 torr) and the hybrid containing the patient's beta chains had a P50 similar to the patient's "stripped" hemolysate. It was assumed therefore that the mutation was in the beta chain; structural studies using cyanogen bromide cleavage revealed that the patient had Hb San Diego, beta 109 Val replaced by Met, and that the patient's cells contained approximately 50 percent mutant hemoglobin.

Aged↗
PubMed1980

Possible gonadal mosaicism in a family with hemoglobin Köln.

A brother and sister were the first members of a family to possess hemoglobin Köln (alpha 2 beta 2(98) Val leads to Met). Studies of these siblings and their parents strongly indicated that the anomaly had arisen by spontaneous mutation. Gonadal mosaicism of one of the parents offers the best explanation for the appearance of a spontaneous mutation in multiple members of a sibship.

Adult↗
PubMed1976

Ultrastructure of sickling and unsickling in time-lapse studies.

The denser subpopulation of erythrocytes from patients with sickle cell anaemia was deoxygenated to a pO2 of 4.7 kPa or reoxygenated to a pO2 of 12 kPa with a continuous-flow apparatus. Samples were collected into modified Karnovsky's fixative at intervals between 0.5 and 15 S. .The earliest event after deoxygenation was aggreagation of haemoglobin followed by the formation of fibres of 160-200 A diameter. The polymers were always randomly distributed in a loose network. A highly ordered, close packing of fibres characteristic of the nematic liquid crystal was not achieved within 15 S. Depolymerization involved a shortening of fibres followed by aggregation similar to that observed early in the polymerization process and prior to the return to the unperturbed state. Irreversibly sickled cells were the first to demonstrate polymers following deoxygenation and that last to lose polymers after reoxygenation. Polymerization of the haemoglobin preceded the appearnce of the sickled deformity of reversibly sickled cells and, following reoxygenation, the return to the discoid shape lagged behind the disappearance of polymers. These studies, carried out under physiologic conditions, have demonstrated intracellular changes during time intervals that correspond to the normal venous and arterial circulation that may contribute to the pathophysiology of sickling disorders.

Adolescent↗
PubMed1975

Dimethyl adipimidate: a new antisickling agent.

A new approach to the prevention of sickling in vitro by use of the bifunctional crosslinking reagent, dimethyl adipimidate, is described. Prior treatment of sickle erythrocytes with dimethyl adipimidate will inhibit sickling in completely deoxygenated erythrocytes. Treated erythrocytes do not demonstrate the potassium loss and viscosity increase that usually accompany sickling. The oxygen affinity of hemoglobin in these cells is increased independently from changes in the concentration of 2,3-diphosphoglycerate. The hemoglobin obtained from treated erythrocytes contains a high-molecular-weight component as well as additional positively charged components. The relative degree to which chemical modification and/or crosslinking is an essential part of the antisickling properties of the material is not known.

Adipates↗
PubMed1972

Structural and functional studies on hemoglobin Bethesda (alpha2beta2 145His), a varient associated with compensatory erythrocytosis.

Studies have been performed on a 12-yr-old Chinese girl with compensatory erythrocytosis due to the presence of hemoglobin Bethesda comprising about 45% of the red cell hemoglobin. Her parents and three siblings were normal. The oxygen affinity of her blood was markedly increased: under physiological conditions (pH 7.40, 37 degrees C). P(50) was 12.8 mm Hg (normal = 26.5 mm Hg). The red cell 2,3-diphosphoglycerate (2.3-DPG) level was normal. The abnormal hemoglobin could not be separated from hemoglobin A by zone electrophoresis at pH 8.6 or isoelectric focusing on polyacrylamide gel. However, after the hemoglobin was split into free alpha and beta chains by treatment with p-hydroxymercuribenzoate (PMB) or 6 M urea, an abnormal beta chain was readily demonstrated having a higher isoelectric point (more positive net charge) than normal beta(A). Structural analysis of the variant beta chain demonstrated the substitution of histidine for tyrosine at position 145: hemoglobin Bethesda (alpha(2)beta(2) (145His)). From earlier chemical and crystallographic studies, it has been postulated that this residue is a critical determinant of hemoglobin function. Hemoglobin Bethesda was separated from hemoglobin A by column chromatography. Oxygen equilibria of purified hemoglobin Bethesda revealed an extremely high oxygen affinity (exceeding that of isolated alpha and beta chains), and markedly reduced cooperativity. The Bohr effect of hemoglobin Bethesda was 1/3 that of hemoglobin A. However, hemoglobin Bethesda showed a significant interaction with 2.3-DPG and inositol hexaphosphate.

Adenosine Triphosphate↗