Search PubMed⌕ Search

Biomedical subjects

S Abrahamson

Publications and source records attributed to S Abrahamson.

At least 19 recordsLinked to original sources
PubMed1999

Continuing medical education for life: eight principles.

Continuing medical education (CME) is being pressured to change in response to increasing and changing educational needs of practicing physicians, fostered by technical innovations, evolution of practice styles, and the reorganization of health care delivery. Leadership in the reform of CME falls primarily to the medical specialty societies in light of their traditional responsibilities for accrediting CME and maintaining professional standards. To address the need for reform, the American College of Obstetricians and Gynecologists in 1997 organized a conference to assemble CME program administrators from several medical specialties and academicians with expertise in postgraduate learning. At the conference, issues facing CME were examined. The authors, who were conference participants, state and explain eight principles that emerged from conference discussions. (For example: "Educational activities should be supportive of and coordinated with the transition to evidence-based medicine.") The principles reflect the interspecialty and interdisciplinary consensus achieved by the conference participants and can serve as useful guideposts for educators as they work to improve CME in their institutions. The authors conclude by noting the need for a more systematic and rigorously analytic approach, where CME content is determined according to assessed needs and CME is evaluated by measuring outcomes; for this to happen, CME educators and faculty must be brought up to date through training, including the use of problem-based learning. CME must also instill collegiality, interaction, and collaboration into the learning environment instead of being a solitary learning activity. Finally, CME must not only emphasize the acquisition of knowledge but also instruct physicians in the process of decision making to help them better use their knowledge as they make clinical judgments.

Clinical Competence↗
PubMed1997

Postoperative hyponatremia despite near-isotonic saline infusion: a phenomenon of desalination.

BACKGROUND: It is widely presumed that the development of postoperative hyponatremia (which may be severe) results from administration of hypotonic fluids while antidiuretic hormone is acting. OBJECTIVE: To show that hyponatremia would occur in patients 24 hours after surgery if only near-isotonic solutions are given and to evaluate the mechanisms responsible for hyponatremia in this setting. DESIGN: Prospective cohort study. SETTING: University medical center. PATIENTS: 22 women who were having uncomplicated gynecologic surgery with infusion of near-isotonic solutions only (sodium chloride, 154 mmol/L, or Ringer lactate [sodium, 130 mmol/L, and potassium, 4 mmol/L]). MEASUREMENTS: Plasma electrolyte levels were measured at the time of induction of anesthesia and 24 hours later. Data on the balance of water and electrolytes were obtained for the same 24-hours period. RESULTS: At the time of induction of anesthesia, the plasma sodium concentration was 140 +/- 1 mmol/L; 24 hours later, it decreased in 21 of 22 patients (mean decrease, 4.2 +/- 0.4 mmol/L [P < 0.001]; lowest level, 131 mmol/L in 2 patients). The urine remained hypertonic (peak sodium plus potassium concentration in urine, 294 +/- 9 mmol/L) in all patients for the first 16 hours after induction of anesthesia. CONCLUSIONS: Postoperative hyponatremia occurred within 24 hours of induction of anesthesia when only near-isotonic fluids were infused. Hyponatremia was generally caused by generation of electrolyte-free water during excretion of hypertonic urine-a desalination process. This electrolyte-free water was retained in the body because of the actions of antidiuretic hormone. If the pathophysiology of this hyponatremic state is understood, recommendations for its prevention and treatment can be deduced.

Adult↗
PubMed1996

Expression and characterization of cysteine-modified variants of an amino-terminal fragment of bactericidal/permeability-increasing protein.

rBPI23 is a biologically active, recombinant N-terminal fragment of human bactericidal/permeability-increasing protein (BPI). While rBPI23 is readily purified from culture supernatants of Chinese hamster ovary (CHO)-K1 transfectants, it is heterogeneous, consisting of monomer and disulfide-linked dimer, characteristics due presumably to the presence of three cysteines within the molecule. We have examined the role of these cysteines in rBPI23 expression, function, and dimer formation by mutating their codons to alanine (C132A), serine (C135S), or alanine (C175A) and expressing analogues of N-terminal fragments ("variants") lacking one, two, or all three cysteines in permanently transfected CHO-K1 cells. We also expressed a variant in which serine 18 was changed to cysteine (S18C), as found in both bovine and rabbit BPI. The C132A variant was readily secreted and purified as a homogeneous, stable monomeric protein species. The C135S and S18C variants were produced as mixtures of monomer and dimer; the C135S variant was poorly secreted, difficult to purify, and unstable on storage. In contrast, the C175A variant and those lacking any two or all three cysteines were expressed but not secreted. Purified rBPI23 and the C132A and S18C variants had comparable bactericidal and lipopolysaccharide (LPS) binding activities and were similarly effective at neutralizing LPS-induced tumor necrosis factor synthesis by THP-1 cells; the purified C135S variant lacked all activities. From these studies with CHO-K1 transfectants, we conclude that (i) cysteines 135 and 175 are both necessary for efficient secretion of a biologically active N-terminal BPI fragment, presumably through the formation of a disulfide bond, (ii) cysteine 132 is responsible for dimer formation, and (iii) only the C132A modification yields a stable, biologically active, N-terminal BPI fragment (designated rBPI21) that is free of dimeric species.

Animals↗
PubMed1996

Time to return medical schools to their primary purpose: education.

The author maintains that the quality of medical education has been dropping for the last few decades as medical schools become less and less focused on their primary purpose of training physicians. Until the years immediately following World War II, the administration of the medical school was carried out by a small staff headed by a dean whose role was to provide leadership in educational matters. Academic departments managed the educational program, and the faculty were expected to be teachers and to participate in educational planning, preparation of teaching materials, advising of students, assessment of students' performances, admission, and all other tasks associated with having a teaching position. Today, the administration of a typical school includes any number of assistants to the dean and a wide variety of other staff dealing not only with educational functions but with grant management, public relations, fund-raising, personnel policy, budgeting, and an enormous and complex parallel structure designed to manage clinical practice and to respond to market pressures. The role of faculty has also changed greatly; faculty are expected to be researchers and clinicians first, and teaching is usually shortchanged. The author explains why he believes these changes have come about; for example, the strong federal support of research after World War II, which encouraged a growing dependence of medical schools on research grants and consequently raised in importance those faculty who could obtain such grants. He concludes with common-sense proposals for reform (such as having the education of medical students in the hands of a small number of faculty whose prime responsibility is teaching), but admits that there are fundamental barriers to such reforms, especially vested interests and resistance to change. In the end, change will come only when those in power recognize that medical schools must be returned to their primary role of training physicians.

Education, Medical↗
PubMed1995

An educational intervention to improve hospital tumor conferences.

Hospital tumor conferences exist to improve patient care through the application of a multidisciplinary approach to cancer management decisions and to provide continuing medical education for physicians and other health professionals who participate in cancer care. Based on educational needs identified by means of direct observation of conference sessions, this study implemented an experimental intervention designed to increase the educational benefits associated with participation in these conferences. Participating hospitals were randomly assigned either to a study group that received an "educational case" intervention (emphasizing progressive disclosure of cases, an active leadership style, and use of educational principles such as stating objectives at the beginning of sessions) or to a control group receiving no intervention. Each of the nine experimental and nine control group hospitals had multiple tumor sessions and case presentations with sessions observed and coded before and after intervention. Results showed significant differences in the specific educational procedures emphasized in the educational case intervention, such as use of the progressive disclosure method of presentation, and quality of session leadership. No difference, however, was found in other factors such as participation rates by major categories of specialists. The study has thus shown that educational interventions of this type can have a significant impact on the clinical and educational effectiveness of ongoing hospital conferences.

Education, Medical, Continuing↗
PubMed1995

Educational characteristics of tumor conferences in teaching and non-teaching hospitals.

Hospital tumor conferences (tumor boards) were observed and evaluated over an 18-month period to determine their organizational and educational characteristics as well as their impact on conference participants. In conjunction with a previous nationwide survey of tumor conferences, this study was designed to identify features that would facilitate the learning that occurs in conference sessions. Study investigators observed a regional sample of 43 tumor boards in 37 participating hospitals, which included 513 sessions at general (hospital-wide) conferences and 198 sessions at specialty conferences. A total of 1,866 tumor cases were presented during these 711 conferences. Participants completed questionnaires to supplement the investigators' evaluations. Session observations revealed several ways in which tumor boards could increase their educational impact on participants, including combining case presentations with presentations of related didactic material and using the method of progressive disclosure to promote increased participation in discussions related to retrospective case presentations. Improvements can be made in session organization and case presentation with the potential for increasing participant learning with little increase in the effort or expense associated with tumor conferences.

California↗
PubMed1993

Stable chromosome aberrations among A-bomb survivors: an update.

Analysis of data on stable chromosome aberrations collected between 1968 and 1985 by the Radiation Effects Research Foundation (RERF) on 1703 individuals exposed to A-bomb radiation in Hiroshima and Nagasaki, Japan, reveals different dose-response relationships in the two cities, as well as significant effects of both time of assay and age at exposure. In Hiroshima, the proportion of cells with aberrations increased by 0.080 per sievert at low doses, assuming a constant neutron radiation RBE of 10 relative to gamma radiation, for assays performed during the latest period (1981-1985). In Nagasaki, the low-dose increase was 0.0126 per sievert. There was evidence that radiation exposure was more effective for producing stable aberrations at some younger ages at exposure, although the interpretation of this interaction is difficult. Modeling neutron and gamma-ray components of dose separately in a way which allows the neutron RBE to vary with dose yielded an estimated low-dose limiting value of RBE of 707 (95% confidence bound 200-infinity), with a low-dose response of approximately 0.008 aberrations per sievert. This RBE is much higher than the published RBEs for induction of aberrations in vitro. The high estimated RBE and the differences in dose response by city both are suggestive of systematic dose estimation errors in which either neutrons were underestimated in Hiroshima or gamma rays were overestimated in Nagasaki.

Adolescent↗