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Biomedical subjects

D R Rovner

Publications and source records attributed to D R Rovner.

At least 19 recordsLinked to original sources
PubMed1989

Methods of analyzing physician practice patterns in hypertension.

A principal method of studying physician practice patterns has been to examine physicians' responses to brief written cases. We have compared this method with practice patterns of the same physicians derived from chart audit. Subjects were 98 family practice residents for whom data were available in actual patient encounters for the workup of asymptomatic hypertension. Short, carefully structured case reports using four cues were designed and a checklist similar to the one used for test ordering in practice was employed. Chart reviews and billing encounter forms were used for comparison. Results indicated residents ordered fewer tests in clinical practice, due, in part, to practice constraints not represented in the written cases. Physicians tend to make the diagnosis of hypertension incrementally in practice, with no one visit adequately representing the point of diagnosis. Studies based on data bases using a patient encounter as the unit of analysis in chronic disease such as hypertension may spuriously underestimate the actual number of tests ordered for the workup. Judgment cases may better reflect the patterns of use of information in a well-defined problem. Prediction of number of tests ordered in the clinical setting has not been established in this case.

Adult↗
PubMed1989

Treatment of hyperthyroidism in community hospital.

The preferred treatment of hyperthyroidism remains controversial. Most of this data is derived from large, university-based medical centers. We report here our experience with treatment of hyperthyroidism in a community setting. This involves 144 patients with hyperthyroidism who were seen over a 10 year period at Michigan State University Clinical Center and were treated in the community hospitals and private physicians' offices, and by community surgeons. Follow-up data were available on 119 of these patients; 105 of them were hyperthyroid because of Graves' disease and multinodular goiter. Patients were encouraged to make their own decisions regarding choice of therapy, as independently as possible. Sixty-five percent of these patients were treated by 131I, 18% by antithyroid drugs, and 17% by surgery. The mean follow-up period was 2.5 years (range 2 months to 19 years). Hyperthyroidism was controlled in 84% of the patients treated by 131I and 83% of the patients treated by surgery. Forty percent of the patients treated by 131I and 33% treated by surgery became hypothyroid. Fifty percent of the patients achieved remission when treated by antithyroid drugs alone. Our results indicate that when patients are encouraged to make their own decisions regarding the treatment of hyperthyroidism, their choices are similar to those of the thyroidologists. Secondly, the results obtained with different modalities of treatment for hyperthyroidism in a community setting are similar to those obtained in university medical centers.

Adolescent↗
PubMed1988

Alteration of radioactive iodine uptake after treatment of hyperthyroidism with iodine 131.

To determine whether a therapeutic dose of iodine 131 affects the results of 24-hour radioactive iodine uptake (RAIU) testing, we reviewed records of hyperthyroid patients previously treated with 131I at Michigan State University and its affiliated hospitals. We identified 26 patients who had had clinical evaluation and determination of the serum thyroxine (T4) level, triiodothyronine resin uptake (T3RU), and RAIU (using 131I) within two weeks before and several months after the therapeutic dose of 131I. Before treatment, all patients had clinical hyperthyroidism, with an elevated T4 level and increased T3RU and RAIU. After treatment with 131I, eight patients (31%) had an RAIU that was discordant with their clinical and biochemical (T4 and T3RU) assessment. In six patients (23%) of the RAIU was inappropriately high, and in two patients (8%) it was inappropriately low. Since we did not identify any other factors known to interfere with the results of RAIU testing, we conclude that a therapeutic dose of 131I, may by itself increase or decrease a subsequent RAIU determination; therefore, after treatment with 131I, RAIU is not a good diagnostic index of thyroid activity.

Adult↗
PubMed1988

Effect of thymosin (fraction 5) on the plasma levels of glucose and glucoregulatory hormones in humans.

Several interactions between thymosin (fraction 5) and the endocrine system have been described in animals, but its effects in humans have not been studied. Plasma levels of glucose, insulin and glucagon were obtained in response to a glucose load before and after treatment with thymosin in eight patients. The glucose tolerance was normal in all subjects and remained so following thymosin administration. No significant changes in the levels of glucagon and insulin were obtained. In six patients, baseline levels of plasma cortisol and ACTH were also obtained. Four out of six patients demonstrated an increase in ACTH levels although the mean differences did not achieve statistical significance. Plasma cortisol levels also did not change significantly. We conclude that thymosin given over a short term is unlikely to significantly influence carbohydrate metabolism. Since four out of six patients showed an increase in basal ACTH levels, it suggests that thymosin may affect the hypothalamic pituitary/adrenal axis. However, further study is needed for complete evaluation of these effects.

Adrenocorticotropic Hormone↗
PubMed1987

Elevated beta-human chorionic gonadotropin and a search for cancer.

Elevated human chorionic gonadotropin levels may be an early, and occasionally the only, manifestation of embryonal cell carcinoma. A 24-year-old man presented with gynecomastia, galactorrhea, and elevated beta-human chorionic gonadotropin levels, which led to an extensive (but nonrevealing) search, including computed tomography and selective testicular vein catheterization, for malignancy. Since the testicle was considered as the most likely site of tumor, right orchiectomy and right common iliac lymph node biopsy were performed. The testicle was normal, but the lymph node contained elements of embryonal and choriocarcinoma. Following chemotherapy, beta-human chorionic gonadotropin levels were normalized and the patient appears "cured." This case emphasizes the need for an extensive search for malignancy and consideration of orchiectomy in such instances in order to achieve a favorable outcome.

Adult↗
PubMed1987

Social policy and professional self-interest: physician responses to DRGs.

Prospective hospital reimbursement based on Diagnosis Related Groups (DRGs) began in 1983 for Medicare patients, and many states are adopting similar systems for Medicaid recipients in an attempt to curb rising health care costs. Because of their unprecedented intrusiveness compared to previous cost-containment measures and because they explicitly introduce financial incentives to reduce services, DRGs have great potential to affect health care delivery. To determine the effects of DRGs on hospitals and physicians, six months of ethnographic fieldwork was carried out on the medicine and pediatrics services of a university-affiliated hospital during the first year of DRG-based reimbursement. Observations and interviews were used to discern institutional responses to DRGs and physician knowledge of, experience with, and reactions to this cost-containment effort. Our findings indicate that the hospital instituted many changes to protect its interests. Data gathered from patients' abstracts suggest providers are successfully dealing with the new system; the average length of stay for Medicare patients was reduced by 38% in the first year of prospective reimbursement, compared with a 15% reduction for other patients (P less than 0.05). As a group, the physicians made no organized effort to educate themselves about the new cost-containment regulations. Their knowledge of DRGs was vague and included many misconceptions. Their response was not a coherent one taking broad social concerns into account. Cost-containment was viewed negatively, as a threat to the financial integrity of the hospital, patient care, and professional autonomy.(ABSTRACT TRUNCATED AT 250 WORDS)

Attitude of Health Personnel↗
PubMed1986

Comparison of physicians' decisions regarding estrogen replacement therapy for menopausal women and decisions derived from a decision analytic model.

Decisions regarding estrogen replacement therapy were obtained from 50 physicians for 12 cases representing menopausal women with systematically varying levels of cancer risk, fracture risk, and symptom severity. Their decisions were compared with a decision analytic model for which each physician provided needed quantities--subjective probabilities, utilities of various outcomes, and weightings of the importance of the outcome categories. The majority of observed decisions were not to treat. By contrast, the decision analysis based on physician-provided estimates indicated that the optimal strategy was either to treat or a toss-up. Sensitivity analysis showed that these conclusions would hold over all possible utilities, over all plausible probabilities of cancer, and so long as symptom relief and fracture prevention were also considered as treatment objectives. The increased probability of early detection of cancer by regular follow-up was systematically incorporated into the decision analysis but apparently neglected in unaided clinical judgment, which follows the principle of minimizing the most important risk, regardless of its probability.

Decision Theory↗
PubMed1986

Factitious hypoglycemia. Clues to identifying an elusive disorder.

Factitious hypoglycemia is similar in presentation to insulinoma and occurs most commonly in persons with ready access to insulin. Diagnosis previously was based on circumstantial evidence but now can be confirmed by demonstration of high insulin levels and low C-peptide levels in the presence of hypoglycemia. Treatment is primarily psychiatric, and success so far is limited.

Adult↗
PubMed1986

Human insulin. Its development and clinical use.

With the recent availability of human insulin, we have entered a new era in therapy for diabetes mellitus. Human insulin is not a cure for diabetes; however, no disadvantages are known to be associated with its use at present. Human insulin costs less than the other purified insulins, and because of its potential advantages, human insulin deserves consideration for use in all newly diagnosed insulin- dependent diabetics.

Amino Acid Sequence↗
PubMed1986

Hormonal effects of smoking--I: Effects on plasma renin activity.

It is generally recognized that smoking is associated with an increased risk for the development of coronary artery disease. Since it has been suggested that increased plasma renin activity (PRA) may be a risk factor for cardiovascular disease, PRA was measured in a group of smokers and nonsmokers. PRA was measured under basal conditions, following intravenous (IV) furosemide administration and after a short burst of smoking. In addition, the effect of nicotine on renin secretion was evaluated in vitro. Smoking was associated with a significant increase in pulse rate and systolic blood pressure, but no significant change in diastolic blood pressure in both groups. Basal PRA was similar among smokers and was not significantly influenced by smoking in either group. PRA increased significantly following IV administration of furosemide, but there was no significant difference between the two groups. Incubation of rat kidney slices with nicotine also did not result in increased renin secretion. These findings confirm that smoking affects the cardiovascular system, but no significant effect of smoking on PRA was observed both in vivo and in vitro experiments. These findings suggest that the increased risk for the development of coronary artery disease associated with smoking is not mediated by increased PRA.

Adult↗
PubMed1986

Hormonal effects of smoking--II: Effects on plasma cortisol, growth hormone, and prolactin.

Effect of smoking on the plasma levels of cortisol, growth hormone, and prolactin was evaluated in a group of smokers and nonsmokers. Plasma levels of these hormones were measured under basal conditions and following a short burst of smoking. In addition, to determine the mechanism of action of nicotine on the release of these hormones, rat renal cortical slices were incubated with nicotine and the generation of cyclic AMP was measured in vitro. Increasing concentrations of nicotine in the incubation medium resulted in increased generation of cyclic AMP. Basal levels of plasma cortisol were similar for both smokers and nonsmokers. After smoking, the cortisol levels increased significantly among smokers only and the levels achieved were significantly higher compared with nonsmokers. Mean prolactin curves were higher among nonsmokers compared with smokers, whereas growth hormone levels were similar in the two groups. These data suggest that the effects of smoking on pituitary/adrenal hormones differ among smokers and nonsmokers and that these effects may be mediated through increased generation of cyclic AMP induced by nicotine.

Adult↗
PubMed1985

Diabetic ketoacidosis: outcome in a community hospital.

The mortality among patients with diabetic ketoacidosis (DKA) has been reported to be as high as 5% to 15%. To determine the outcome of DKA, we reviewed the charts of all patients admitted to one of our community affiliated hospitals for the period of January 1979 to December 1981. We identified 66 episodes of DKA in 42 patients. All patients received intravenous fluids. Insulin was given by continuous infusion in six (9%), by bolus only in 14 (20%), and by a combination of the two in 46 (71%). The mean time for recovery from DKA was similar in all three subgroups. All patients recovered from DKA and were discharged from the hospital; no deaths occurred. We conclude that it is possible to treat DKA effectively in a community hospital, with mortality approaching zero.

Adolescent↗
PubMed1985

Rationale for physicians' decisions to refer obese patients.

Health care costs are an increasing burden upon American society. Referral of patients to a specialist generates additional cost. We studied the reasons behind decisions to refer patients with uncomplicated obesity to endocrinologists. Obesity may be viewed as a paradigm of diseases with relatively well-known etiology, low morbidity and mortality, chronicity, and poor outcome from standard therapy. In addition, it is a disease that is rarely curable by medical intervention, requiring behavioral change. Physicians have little direct experience in the differential diagnosis of endocrine disease, because of its low prevalence. We studied the referral decisions of 45 physicians in three medical specialties. Clinical decision making was studied using a standard set of 24 carefully structured case reports of obese women, all without obvious endocrine disease cues on history or physical. In these cases the patients' desire to be seen by endocrinologists was the major factor in the decision to refer. Referrals were not made primarily to rule out suspected endocrine disorder or because of concern for increased risk of morbidity.

Body Weight↗
PubMed1985

Systemic allergy to human (recombinant DNA) insulin.

Allergy to insulin is extremely rare and is, in part, due to the differences in amino acid sequence of animal and human insulin. We report here a 37-year-old, white, pregnant woman who was allergic to beef/pork, purified pork, as well as human insulin. She reacted with a wheal and flare reaction in response to intradermal human and purified porcine insulins. She was desensitized to human insulin in order to continue insulin therapy during pregnancy. The course of this patient emphasizes that some patients are allergic even to human insulin and may require desensitization prior to insulin therapy.

Adult↗
PubMed1979

Effect of tolbutamide on plasma renin activity.

The effect of tolbutamide on renin secretion in rats was studied in vivo, and in vitro. Administration of tolbutamide in doses of 12.5 and 25 mg/kg body wt ip to two groups of rats produced no significant change in plasma renin activity compared to the control group. In the in vitro experiments renal cortical slices were incubated with increasing concentrations of tolbutamide (0--4 mg/ml). No significant increase in the net renin production was observed, whereas the concentration of cyclic AMP increased significantly in the incubation medium. These findings suggest that in the intact rats tolbutamide does not increase plasma renin activity. In the renal cortical experiments although tolbutamide increased cyclic AMP production, the increase may not have been sufficient to stimulate the net renin production. These results are of biological significance because of the possible effects of tolbutamide and increased plasma renin activity on the cardiovascular system.

Animals↗
PubMed1979

17 alpha-Hydroxylase deficiency. A combination of hydroxylation defect and reversible blockade in aldosterone biosynthesis.

We have studied the hormonal secretion and excretion patterns in a patient with the XX type of 17 alpha-hydroxylase deficiency. In the untreated state, the patient's urine contained only those steroids which do not require 17-hydroxylation in their biosynthesis. Aldosterone was not produced in the patient and the metabolic product of its immediate precursor, 18-hydroxy-11-dehydro-tetrahydrocorticosterone, was excreted in markedly elevated amounts. This apparent complete block in 18 oxidation was reversible upon long-term ACTH suppression within 27 days. Direct in vitro incubation of the patient's adrenal gland removed at operation demonstrated, 1) the complete lack of 17 alpha-hydroxylase activity, 2) the functional block in the ability to oxidize the hydroxyl group at the 18 methyl side chain. The addition of physiological concentrations of angiotensin to the incubation medium further showed, 3) angiotensin mildly stimulated the entire aldosterone biosynthetic pathway, 4) angiotensin directly stimulated the conversion of 18-hydroxycorticosterone to aldosterone. We propose that in this patient, 17-hydroxylase deficiency produced a decreased plasma concentration of cortisol, followed by stimulation of deoxycorticosterone production by ACTH. The resultant increase in extracellular fluid volume suppressed plasma renin activity. This resulted in a low plasma concentration of angiotensin II which directly suppressed oxidation of 18-hydroxycorticosterone to aldosterone. This defect has been called corticosterone methyl oxidase defect type 2.

18-Hydroxycorticosterone↗