Biomedical subjects
W A Nelson
Publications and source records attributed to W A Nelson.
The teaching of medical ethics in oncology education.
The teaching of medical ethics is an important aspect of oncology education. To prepare future physicians to cope with the many and complex ethical issues in the care of oncology patients, Dartmouth Medical School developed a two-hour medical ethics component in the required second-year course on the principles of oncology. The paper describes the goals and case method for the teaching of ethics.
Clinical ethics education in the Department of Veterans Affairs.
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Mechanism of the effects of glucocorticoids and mineralocorticoids on vascular smooth muscle contractility.
We have previously demonstrated that receptors to both mineralocorticoids (MC) and glucocorticoids (GC) exist in the arterial wall and that treatment with GC markedly increases Na+ and Ca2+ influx in cultured aortic vascular smooth muscle (VSM) cells, whereas treatment with MC increases only Na+ influx. We now report the results of the study aimed at the elucidation of the mechanism(s) of these effects. Unidirectional influx of Na+ and Ca2+ was measured in cultured cells of rabbit aortic media, using 22Na and 45Ca as tracers, in the presence of ouabain. The cells were treated for different periods with dexamethasone (DEX) or aldosterone (ALDO) in physiologic or supraphysiologic concentrations, in the presence or absence of competitive inhibitors of GC-receptor binding, RU 486, or MC-receptor binding, K-prorenoate. DEX in 50 nM concentration increased Na+ influx by 98 +/- 18% and Ca2+ influx by 100 +/- 20%, and the maximum effect was seen after 48 hour cell-treatment. ALDO in 5 nM concentration increased Na+ influx by 90 +/- 12% and had no effect on Ca2+ influx, and the maximum effect was seen after 7-10 days of cell-treatment. The enhancing effect of both DEX and ALDO on the influx rate of Na+ was prevented by actinomycin D and by cycloheximide. RU 486 completely inhibited DEX from exercising its enhancing effect on Na+ influx, but diminished influx rate of Na+ increased by ALDO only by 25%. Prorenoate (PRN) did not have any effect on DEX-increased Na+ influx, but completely inhibited ALDO from exercising its effect.(ABSTRACT TRUNCATED AT 250 WORDS)
The ethical role of the consultant.
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Glucocorticoids regulate Na+ transport in vascular smooth muscle through the glucocorticoid receptor-mediated mechanism.
The incidence of hypertension in conditions of chronic glucocorticoid (GC) excess is very high, though the mechanism whereby GC elevate blood pressure is far from being understood. We have recently found that GC markedly increase influx of Na+ in vascular smooth muscle (VSM) cells. We and other investigators have previously described receptors for GC in arterial tissues, and we have now examined whether the effect of GC on Na+ transport in VSM is mediated through these receptors. Vascular smooth muscle cells were cultured from rabbit aortas. The cells were treated for 48 h with 10(-7) mol/L dexamethasone (DEX), in the presence or absence of RU 486, a competitive inhibitor of DEX binding to its receptor, or progesterone, an allosteric accelerator of DEX dissociation from the receptor. Unidirectional influx of Na+ was measured with 22Na as tracer. Dexamethasone more than doubled the influx rate of Na+, RU 486 completely prevented this increase, and progesterone reduced the DEX-induced increase by approximately 80%. The time of the cell exposure to DEX necessary for the DEX effect to occur was 4 to 6 h, with a maximal effect at 48 h, suggesting a genomic effect. Addition of protein synthesis inhibitors, actinomycin D or cycloheximide, to VSM cells cultured in the presence of DEX prevented the increase of Na+ influx by DEX.(ABSTRACT TRUNCATED AT 250 WORDS)
Fine-needle aspiration biopsy of small round blue cell tumors of childhood.
One hundred twenty-eight palpable and deep-seated fine-needle aspiration biopsies (FNAB) were done on pediatric patients at James Whitcomb Riley Hospital for Children and Indiana University Hospital between 1985 and 1988. During that 4-year period, 71 (56%) benign and 49 (38%) malignant diagnoses were made. Only eight (6%) of the FNAB were considered inadequate. Thirty-nine (80%) of the malignant aspirates were small round blue cell tumors of childhood (SRBCT). The SRBCT consisted of 21 (54%) lymphomas, 7 (18%) Ewing's sarcomas, 3 (8.5%) neuroblastomas, 3 (8.5%) rhabdomyosarcomas, 2 (5.0%) medulloblastomas, 2 (5.0%) Wilms' tumors, 1 (3.0%) retinoblastoma, and 1 (3%) granulocytic sarcoma. Fifteen (38%) of the SRBCT aspirates were obtained to render a primary diagnosis and 24 (62%) documented recurrence. Various combinations of electron microscopy, immunocytochemistry, and other special stains were used to confirm the diagnosis in 11 (28%) cases. These cases consisted of five lymphomas, two rhabdomyosarcomas, two Ewing's sarcomas, one neuroblastoma, and one granulocytic sarcoma. The technique of FNAB is a successful diagnostic tool for documenting primary and recurrent SRBCT in a pediatric population.
Using ethics advisory committees to cope with ethical issues.
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A look in the mirror: a critical and exploratory study of public perceptions of the chiropractic profession in New Jersey.
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A critical look at the subluxation hypothesis.
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A study of the dying process in elderly hospitalized males.
The dying process was studied by questioning nurses and next of kin of 40 consecutive patients who died in an acute care Veterans Hospital. Information regarding problems commonly thought important in the dying process was elicited and attempts were made to relate this information to global assessments of quality of life during the preterminal week and quality of the moments surrounding death. Despite long-standing awareness of many of these problems, important pain, respiratory difficulty, mood problems, blunted alertness, stooling problems, urination problems, and oral intake problems each was present in at least 50% of patients. Multivariate analysis did not define a convincing relationship between these problems and global assessments of quality. Responses of nurses and next of kin were similar most of the time, but nurses systematically rated pain as less severe than next of kin and next of kin systematically demonstrated less awareness of urinary and stooling problems than nurses.
Stress X-rays and the low back pain patient.
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Protection of practice rights.
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Sensitivity study of H-reflex alterations in idiopathic low back pain patients vs. a healthy population.
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Moral theory and neurology.
This article presents an outline of a general moral theory and shows its relationship to the concepts of paternalism and that of valid consent and refusal. The authors then show how this theory and these concepts can be usefully applied to the moral problems that neurologists often face in determining how to act when they have distressing information for their patients. Finally, a procedure is provided for determining when it is morally justified to deceive patients by withholding information about their diagnoses, prognoses, or about their prospective treatments.
Decisions to withhold or terminate treatment.
Decisions to withhold or terminate treatment are common clinical dilemmas in patients dying from diseases of the nervous system. Decision making for such patients must be based upon ethical principles. Under the doctrine of valid consent and refusal, competent patients have the right to refuse life-sustaining therapies. For incompetent patients, this right may be exercised through their previously executed advanced directives or through appointed proxy decision makers. Physicians have the duty to assess the potential benefits and harms of various treatment options and to clearly communicate this information to patients and their proxies in a supportive manner. The authors illustrate the application of ethical principles in neurologists' management of patients in persistent vegetative states, dementia, and end-stage neuromuscular disease.
Skin eruptions in ked infected sheep.
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Fine-needle aspiration of metastatic atrial myxoma.
Atrial myxoma is the most common primary neoplasm of the heart, but "metastatic" or embolic phenomena are rare. The first reported case of "metastatic" atrial myxoma diagnosed by fine-needle aspiration biopsy is presented. It occurred in a 54-yr-old woman with multiple metastatic lesions. The cytologic and histologic findings of the fine-needle aspiration biopsy and subsequent surgical excision are presented as is a discussion of the incidence, origin, and clinical findings of atrial myxoma and the characteristics of its emboli.