Additive effect of theophylline on the cardiac response to isoproterenol

To ascertain the effect of theophylline on the cardiac chronotropic response to beta-adrenergic stimulation, isoproterenol dose-response curves in healthy young subjects were compared during saline and theophylline maintenance infusions. Each study was repeated 1 to 3 weeks later to evaluate reproducibility. Neither the dose of isoproterenol required to raise the heart rate by 25 bpm (2.32 +/- 0.81 vs. 1.55 +/- 0.46 micrograms on day 1 and 1.28 +/- 0.22 vs. 1.27 +/- 0.25 micrograms on day 2) nor the slopes of the dose-response curves were affected by theophylline. Higher heart rates were observed after isoproterenol bolus dosing during theophylline than during saline infusion because of additive chronotropic effects of theophylline and isoproterenol. Since theophylline does not interact in a synergistic fashion with isoproterenol, phosphodiesterase inhibition appears to be an unlikely mechanism of the chronotropic effect of methylxanthines at therapeutic concentrations.     

Acute hemodynamic effects of piroximone (MDL 19,205) in patients with moderate congestive heart failure: comparison with sodium nitroprusside

Piroximone (MDL 19,205), a new imidazolone derivative, was given intravenously to 14 patients with congestive heart failure (NYHA class II-III), while under constant daily doses of digitalis and diuretics. In the first 3 patients, we determined the dose safely eliciting a favorable hemodynamic response. The subsequent 11 patients received 1 mg/kg of piroximone intravenously, and the hemodynamic effects were compared with those of sodium nitroprusside (SN) at a dose-lowering mean blood pressure by 10-20 mm Hg. Piroximone increased heart rate (13.2 +/- 2.0 beats/min, mean +/- SEM) and lowered mean arterial pressure (9 +/- 2.3 mm Hg). Both agents reduced similarly wedge pressure (6.5 +/- 2.9 and 9 +/- 2.9 mm Hg, respectively, for SN and piroximone) and total peripheral resistance. Cardiac index was increased less by SN (15%) than piroximone (48%) (p less than 0.001), and stroke work index significantly enhanced only by piroximone (p less than 0.001). The changes in loading conditions induced by the two agents being similar, it is likely that piroximone not only acts by peripheral vasodilation, but also possesses positive inotropic properties. Myocardial oxygen demand, assessed indirectly by tension-time index, was not affected by piroximone. Thus, piroximone appears to combine well-balanced vasodilator and inotropic properties which make this new agent potentially very useful for the management of congestive heart failure.     

Prosthetic use in elderly patients with dysvascular above-knee and through-knee amputations

Fifty-five patients with vascular insufficiency resulting in above-knee (AK) and through-knee (TK) amputations were studied to determine factors related to prosthetic candidacy and functional outcome. Chart review showed that the only difference between patients who were fitted with prostheses and those who were not fitted with prostheses was their respective number of medical complications. Twenty-three of 31 patients with prostheses were evaluated 7 to 35 months after receiving the prostheses. Ten (44%) of these patients wore their prostheses all day every day and used wheelchairs minimally or not at all. Over half of the patients evaluated used their wheelchairs most of the time. Two (9%) of the 23 patients had stopped wearing their prostheses. Patients who demonstrated increased walking distances and velocities at follow-up used their prostheses more and their wheelchairs less than did the other patients. Neither gait factors nor hip range of motion at discharge was predictive of continued prosthetic use. Functional outcome and prosthetic use were limited in this group of elderly patients with dysvascular AK and TK amputations. The results of this study may serve as a basis for clinical determination of prosthetic candidacy and functional goals.     

Granuloma annulare possibly triggered by antitetanus vaccination

We report the case of a 6-year-old girl with granuloma annulare (GA) possibly related to antitetanus vaccinations. The first episode occurred 2 months after the girl had been vaccinated but the lesions were not located at the vaccination site. After 1 year of being free of lesions, she had a second episode unrelated to vaccination. After another 6-month lesion-free period, the girl was administered another antitetanus vaccination and a solitary lesion developed at the vaccination site within 3 days. A few lesions developed on her legs in the 2 months following the appearance of the initial plaque. The literature includes two reports of cases with papular lesions limited to the hepatitis B vaccination site, both histopathologically consistent with necrobiotic granuloma, but clinically not suggestive of GA. To the best of our knowledge, GA following antitetanus vaccination and occurring at the vaccination site has not been reported before. Either the trauma alone from the injection or a vaccine-induced immunological reaction might have triggered the necrobiosis of collagen through some unexplained mechanisms.     

A simple tool to evoke physicians' real training needs.

Commonly used methods for identifying the training needs of general practitioners do not enable the real needs felt during interviews with patients during office visits to be detected. In this study, the authors evaluate how physicians' use of a personal-office-visit diary affects the level of specificity of their expressed training needs. In 1999, the authors carried out a controlled intervention trial using a random sample of 1,038 general practitioners from a region of France, randomized to intervention and control groups. The practitioners in the intervention group were asked to identify their training needs using a personal-office-visit diary. The level of specificity for their expressed needs was compared with that of the expressed needs of the practitioners in the control group. The use of the diary was associated with a significantly higher level of specificity in the training needs identified by the general practitioners who participated. Independent of the intervention, practitioners under 40 years of age, those in urban practice, and those who were members of a continuing medical education (CME) association expressed their training needs with higher specificity. The personal-office-visit diary would seem to be a simple, inexpensive, and useful tool for more specifically identifying training needs, which could help establish more appropriate and better-targeted training programs. However, it should be assessed further by those involved in CME for general practitioners.     

Special Issue: The Fourteenth Annual New York State Office of Mental Health Research Conference: Introduction

Psychiatric Quarterly -     

Human osteoblasts' proliferative responses to strain and 17beta-estradiol are mediated by the estrogen receptor and the receptor for insulin-like growth factor I.

The mechanism by which mechanical strain and estrogen stimulate bone cell proliferation was investigated using monolayer cultures of human osteoblastic TE85 cells and female human primary (first-passage) osteoblasts (fHOBs). Both cell types showed small but statistically significant dose-dependent increases in [3H]thymidine incorporation in response to 17beta-estradiol and to a single 10-minute period of uniaxial cyclic strain (1 Hz). In both cell types, the peak response to 17beta-estradiol occurred at 10(-8) - 10(-7) M and the peak response to strain occurred at 3500 microstrain ((mu)epsilon). Both strain-related and 17beta-estradiol-related increases in [3H]thymidine incorporation were abolished by the estrogen receptor (ER) modulator ICI 182,780 (10-8 M). Tamoxifen (10(-9) - 10(-8) M) increased [3H]thymidine incorporation in both cell types but had no effect on their response to strain. In TE85 cells, tamoxifen reduced the increase in [3H]thymidine incorporation associated with 17beta-estradiol to that of tamoxifen alone but had no such effect in fHOBs. In TE85 cells, strain increased medium concentrations of insulin-like growth factor (IGF) II but not IGF-I, whereas 17beta-estradiol increased medium concentrations of IGF-I but not IGF-II. Neutralizing monoclonal antibody (MNAb) to IGF-I (3 microg/ml) blocked the effects of 17beta-estradiol and exogenous truncated IGF-I (tIGF-I; 50 ng/ml) but not those of strain or tIGF-II (50 ng/ml). Neutralizing antibody to IGF-II (3 microg/ml) blocked the effects of strain and tIGF-II but not those of 17beta-estradiol or tIGF-I. MAb aIR-3 (100 ng/ml) to the IGF-I receptor blocked the effects on [3H]thymidine incorporation of strain, tIGF-II, 17beta-estradiol, and tIGF-I. HOBs and TE85 cells, act similarly to rat primary osteoblasts and ROS 17/2.8 cells in their dose-related proliferative responses to strain and 17beta-estradiol, both of which can be blocked by the ER modulator ICI 182,780. In TE85 cells (as in rat primaries and ROS 17/2.8 cells), the response to 17beta-estradiol is mediated by IGF-I, and the response to strain is mediated by IGF-II. Human cells differ from rat cells in that tamoxifen does not block their response to strain and reduces the response to 17beta-estradiol in TE85s but not primaries. In both human cell types (unlike rat cells) the effects of strain and IGF-II as well as estradiol and IGF-I can be blocked at the IGF-I receptor.     

Effects of Metal Exposures on Juvenile Clams,Mercenaria mercenaria

Bulletin of Environmental Contamination and Toxicology - Elevated metal concentrations occur throughout the coastal zone due to urbanization and various anthropogenic activities. The lethal...