Biomedical subjects
D Rosenberg
Publications and source records attributed to D Rosenberg.
Bronchodilator responsiveness in infants with bronchiolitis.
We evaluated 34 infants with bronchiolitis, (17 of both genders; mean age, 4.6 mos; ranges, 0.7-14.5 mos). The 20 inpatients were significantly younger than the 14 outpatients (2.6 vs. 8.2 months, P < 0.05), and more females were inpatients. Forced expiratory flows at functional residual capacity (VmaxFRC) were obtained at baseline, after aerosolized normal saline (NS), and metaproterenol (0.025 mL/kg in 2 mL NS). Flows were expressed as Z-scores, the difference between the measured and predicted flows, divided by the standard deviation for the predicted value. At baseline, outpatients were more obstructed than inpatients (-1.64 vs. -0.95, P < 0.05), infants > 2 months old were more obstructed than infants < or = 2 months old (-1.54 vs. -0.80, P < 0.05), and males more than females (-1.45 vs. -1.02, P < 0.05). Following NS the whole group had a small but significant decrease in Z-scores (-1.23 to -1.31, P < 0.05). Following metaproterenol, the younger infants had significantly (P < 0.05) higher Z-scores compared to baseline and NS (-0.80 vs. -0.86 vs. -0.59). However, no significant changes occurred in older infants. Females also had an increased flow after metaproterenol and were less obstructed than after NS (-1.11 vs. -0.86, P < 0.015). In males no increased flows occurred after metaproterenol (-1.45 vs. -1.48). Bronchodilator responsiveness did not relate to severity of airway obstruction, history of family asthma, allergy, or passive smoke exposure. We conclude that inhaled metaproterenol improves airway function in a subgroup of infants with bronchiolitis, but the subgroup could not clearly be identified because age and gender were confounding factors.
Experimental states. A few local governments have their own ideas on health-care reform -- and some already work.
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Doctors under the knife.
With Bill Clinton's new reforms only a month away, the health-care system is on the operating table--and the doctors are under the knife. Americans have a love-hate relationship with physicians: they like the care that doctors provide but hold them to blame for the nation's health-care mess. NEWSWEEK looks at how the culture of medicine may change, assesses doctors' fears--and examines the brave new world of HMOs.
Airway responsiveness in infants following bronchiolitis.
Airway responsiveness to inhaled methacholine was assessed in 18 infants, 4 and 10 months old, following bronchiolitis. Pulmonary function was measured from partial expiratory flow-volume curves generated by the rapid compression technique. Sleeping infants inhaled increasing concentrations of methacholine until maximal expiratory flows at functional residual capacity (VmaxFRC) decreased by 30% or 2.5 mg/mL was inhaled. Airway responsiveness was quantitated by: 1) the threshold concentration (log TC) required to decrease VmaxFRC by 2 standard deviations from baseline; 2) the concentration required to decrease VmaxFRC by 30% (log PC30); and 3) the slope of the dose-response curve between TC and PC30 (log SPC30). At both the first and second evaluation, the bronchiolitic infants had lower baseline VmaxFRC (% pred.) than 24 control infants. In addition, the bronchiolitic infants had heightened airway responsiveness compared to controls, demonstrating lower values for logTC and logPC30 and steeper slopes to their dose-response curves (logSPC30). After accounting for the relationship between airway responsiveness and age, the occurrence of bronchiolitis was found to be a significant independent factor 10 months but not 4 months following bronchiolitis. The bronchiolitic infants did not demonstrate the decline in airway responsiveness with increasing age that occurs in normal infants. We conclude that infants exhibit heightened airway responsiveness following bronchiolitis.
Improving pregnancy outcomes: public versus private care for urban, low-income women.
This study describes the characteristics of women who received maternity care from the Chicago Department of Health or from private practitioners in 1988 and the first half of 1989, and who delivered at the University of Illinois Hospital or Cook County Hospital. The risk of preterm low birthweight for the infants of these women was compared according to source of prenatal care. The likelihood of giving birth to a preterm, low-birthweight infant was significantly greater (odds ratio 3.1, 95% confidence interval 2.3-4.0) for women who received care only from private physicians (n = 530) compared with those who received care entirely from the Chicago Department of Health (n = 2465). This relationship remained after adjustment for race, age, parity, history of adverse pregnancy outcomes, smoking, and use of drugs during pregnancy. We examined alternative explanations for these findings, and concluded that although the role of urban public health departments in the direct delivery of maternity care services continues to be a source of controversy, these institutions remain an important provider of such care for low-income women.
[Cervico-dorsal myelomeningocele; syringomyelia].
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[Currarino's syndrome?].
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Comparison of titanium-mesh and porous disc electrodes for epicardial defibrillation.
The object of this study was to compare the effectiveness of chronically implanted porous electrodes with that of smooth mesh titanium electrodes of the same diameter but smaller effective surface area. The criteria used in evaluating the electrodes were (1) acute, subacute, and chronic resistance and (2) acute, subacute, and chronic defibrillation thresholds. Electrode pairs 2.5 cm in diameter were implanted in each of 17 dogs (ten mesh and seven porous). One electrode of each pair was sutured to the right ventricle and one to the left ventricle near the cardiac apex. Defibrillation threshold energy and total resistance were measured at the time of implantation and again 6 and 12 weeks after implantation. The mean initial resistance of the titanium electrodes was 131.7 omega; the mean defibrillation values for the porous electrode implant were 96.9 omega and 7.5 joules, respectively. Three to 6 weeks after implantation, the values for the titanium mesh electrode were 88.9 omega and 12.0 joules, while those for the porous electrode were 59.9 omega and 8.0 joules. In the chronic state, the figures for the titanium mesh electrode were 78.1 omega and 13.0 joules, while those for the porous electrode were 64.3 omega and 8.3 joules. We conclude that defibrillation can be achieved successfully with small epicardial electrodes. The findings suggest that a porous electrode, with its larger effective surface area, has lower electrode/tissue interface resistance in the acute and chronic phases, and, therefore, provides lower defibrillation threshold energy.
Inactivation of fusidic acid by resistant Streptomyces strains.
Streptomyces lividans and several other Streptomyces species are resistant to the steroid-like antibiotic fusidic acid. This resistance is mediated by structural modification of the antibiotic. Using TLC, CD, UV, IR, NMR and mass spectroscopy the structure of one of the resulting inactive compounds was determined. It is derived from fusidic acid by the loss of an acetyl group and the formation of a lactone ring between C-21 and C-16. In addition, helvolic acid, a compound closely related to fusidic acid, has been shown to be modified.
Forget CEA (cost effectiveness analysis). Use DEA (data envelopment analysis)!
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DEA (data envelopment analysis) or dubious efficiency assessment.
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EFPF (economic frontier production function): DEA (data envelopment analysis) preview.
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Productivity analysis: DEA (data envelopment analysis) with fixed inputs.
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Regional perinatal care in crisis: a case study of an urban public hospital.
Regionalized perinatal care is intended to guarantee pregnant women and neonates access to appropriate care regardless of ability to pay. Its effectiveness depends on the willingness of hospitals to transfer high-risk patients according to established protocols and affiliations. This study examines maternal transfers (n = 896) to Cook County Hospital (CCH), a public facility and a designated perinatal center in Chicago. In 1987 and 1988, the majority (68%) of maternal transfers to CCH came from out-of-network hospitals, and 52% of these came directly from another perinatal center. The data indicate that 62% of the out-of-network transfers who delivered were medically high-risk. The study also documents the transfer of women in active labor, a violation of federal law. The term "perinatal dumping" is introduced to mean the transfer of high-risk pregnant women between hospitals for economic rather than medical reasons. Strategies for safeguarding the integrity of regionalized perinatal care are discussed.
Phenylpropanolamine and caffeine use among diet center clients.
We surveyed phenylpropanolamine (PPA) use and overuse among 309 diet center clients. Fifty-one percent of all subjects surveyed reported using PPA drugs: 44 percent used cold medicines and 16 percent used diet aids. Twenty-two percent of diet aid users and 7 percent of cold medicine users reported that they deliberately used more than the dosage recommended to improve efficacy. Among diet aid users, 59 percent also regularly consumed caffeine. Despite package warnings, individuals who had been told by their doctors that they were hypertensive used PPA products as often as normotensive individuals. PPA, the fifth most frequently used drug in the USA, is contained in over-the-counter (OTC) diet aids as well as OTC and prescription cold medicines. Severe adverse drug reactions (ADRs) including hypertensive crisis, stroke and death have been attributed to PPA products. Clinical studies have shown that using greater than recommended doses of PPA and using PPA in combination with caffeine may increase the risk of ADRs. Overweight patients may be particularly at risk for ADRs to PPA because they are likely to be hypertensive and to use diet aids. We recommend informing diet center clients of the potential dangers of consuming PPA products, especially more than the recommended dose, in the presence of hypertension, and when other sympathomimetic drugs are being taken.
[Abnormalities of median cerebral structures associated with gonadotropic insufficiency].
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Transient hypertension after two phenylpropanolamine diet aids and the effects of caffeine: a placebo-controlled follow-up study.
PURPOSE AND PATIENTS AND METHODS: Reports of severe adverse reactions following the ingestion of single (75 mg) or double doses of the sympathomimetic drug phenylpropanolamine (PPA), with and without caffeine, prompted us to undertake a study of the effects of five drug preparations (75 mg PPA, 150 mg PPA, 75 mg PPA plus 400 mg caffeine, 400 mg caffeine, and placebo) in 16 resting, normotensive subjects. The study was of a double-blind, randomized, crossover design. Each subject consented to take the five drug preparations on different study days, which were separated by at least 48 hours. RESULTS: Compared with blood pressure (BP) values obtained after placebo ingestion, significant BP increases occurred over several hours following 150 mg PPA and after 75 mg PPA plus 400 mg caffeine. Significant BP increases after ingestion of 75 mg PPA and after 400 mg caffeine were less frequent. The mean peak BP following 150 mg PPA was 173 +/- 9/103 +/- 4 mm Hg, compared with 148 +/- 4/97 +/- 3 mm Hg after the other three active preparations; after placebo, peak BP reached 137 +/- 8/85 +/- 5 mm Hg. CONCLUSION: These results indicate that 150 mg PPA (the amount in two diet aids) substantially elevates BP. Our findings may explain some of the recent case reports of nontraumatic intracranial hemorrhage in young, healthy persons ingesting PPA at recommended or minimally greater dosages. We suggest physicians inform patients who are likely consumers of PPA (i.e., those with allergies, those with eating disorders, overweight persons, women during the postpartum period) and patients at risk for stroke (i.e., the elderly and hypertensive patients) of the risks of taking more than the recommended amounts of PPA and of combining caffeine with PPA.