Role of angiotensin II in sympathetic nervous system induced left ventricular dysfunction.

Experiments were undertaken to determine whether angiotensin (Ang) II concentration increases during massive sympathetic nervous system (SNS) activation and whether such an increase plays a role in the pathogenesis of SNS-induced left ventricular (LV) dysfunction. We also sought to determine whether excessive Ca2+ uptake through L-type channels due to intense adrenoceptor activation is responsible for the LV dysfunction. AngII concentration was measured in the plasma and myocardium before and after massively activating the SNS with an intracisternal injection of veratrine. In separate experiments, rabbits were given losartan, enalaprilat, enalaprilat plus HOE-140, nifedipine, -Bay K 4866, or saline before massively activating the SNS. LV function was evaluated 2.5 h later. The intense SNS activity caused plasma and myocardial AngII to increase by 400 and 437%, respectively. AngII receptor blockade did not prevent LV dysfunction. In contrast, enalaprilat reduced the degree of dysfunction, but its cardioprotection was abolished by HOE-140. Although nifedipine prevented SNS-induced LV dysfunction, administration of the Ca2+ channel opener, -Bay K 4866, did not increase its severity. Our results indicate that AngII is not involved in the pathogenesis of SNS-induced LV dysfunction and that the cardioprotection provided by angiotensin converting enzyme (ACE) inhibition is due to activation of a bradykinin pathway. Furthermore, the finding that the magnitude of the LV dysfunction was reduced by enalaprilat, and not increased by -Bay K 4866, suggests that intense adrenoceptor activation of L-type Ca2+ channels is not the primary pathogenetic mechanism.

Using chart reviews to assess residents' performances of components of physical examinations: a pilot study.

PURPOSE: To evaluate chart review as a method of assessing residents' performances of physical examinations in an ambulatory care setting. METHOD: In 1992, nurse authors at the Affiliated Hospitals at Canton of the Northeastern Ohio Universities College of Medicine assessed whether 22 internal medicine residents performed ten components of the physical examination by interviewing patient volunteers immediately after the patients' examinations. A total of 89 patient interviewees were included in the analysis; these patients were all new outpatients who had been scheduled for initial visits to obtain complete histories and physical examinations. Charts for the same patients were then retrospectively reviewed. The residents and faculty were blinded to both the chart reviews and the interviews. Statistical methods used were Pearson correlational analysis and variance-component analysis. RESULTS: The interviews and chart reviews showed 81% agreement in component performance. Completeness of the physical examination (whether measured by chart review or interview) did not correlate with other standard methods of resident evaluation, and completeness did not show a significant association with characteristics of the residents and patients. Two of the 22 residents assessed were identified as having completeness scores so low as to be unsatisfactory. CONCLUSION: That residents were identified as failing to perform examination components suggests that chart reviews, especially when independently verified by patient interviews, may be a useful evaluation tool for identifying inadequate performance of components of the physical examination and may identify the need for remediation.

Daily exercise improved blood pressure homeostasis of rats subjected to surgical stress.

The effect of daily spontaneous running on blood pressure homeostasis (BPH) was evaluated in 19 male and 13 female control rats and 7 male and 13 female daily spontaneous running rats subjected to surgery and subsequent repetitive hemodynamic disturbances. BPH was operationally defined as the ability to maintain mean arterial pressure above 60 mmHg during the experimental protocol. The length of time the rats maintained BPH was compared across males and females and trained and control groups. Significant sex (P = 0.01) and training (P = 0.05) effects were found. Females maintained homeostasis longer than males and trained longer than controls. Sex effects were not due to differences in the body mass. The mechanisms responsible for the higher resistance to deterioration of homeostasis merit further investigation.

Pneumococcal bacteremia in three community teaching hospitals from 1980 to 1989.

STUDY OBJECTIVE: To review the clinical and laboratory findings in a large number of patients with pneumococcal bacteremia in the 1980s and identify risk factors associated with increased mortality. DESIGN: Retrospective review of medical records identified by blood culture logbooks and ICD-9 codes. SETTING: Three community teaching hospitals affiliated with a medical school in northeastern Ohio. PATIENTS: 385 inpatients with pneumococcal bacteremia admitted between Jan 1, 1980 and Dec 31, 1989. MEASUREMENTS: Important clinical and laboratory information was abstracted from patients' medical records, compiled, computerized, and analyzed. MAIN RESULTS: The patients' mean age was 48 years. The overall mortality was 25 percent. The mortality increased with age, reaching 42 percent in patients over 65 years old. For these elderly patients, the mortality was higher (55 percent) for patients admitted from nursing homes than patients from the community (36 percent). Higher mortality was also associated with congestive heart failure (p = 0.001), alcoholism/cirrhosis (p = 0.02), diabetes mellitus (p = 0.05), and malignancy (p = 0.02). A platelet count less than 150,000/mm3, renal dysfunction (serum creatinine > 2 mg/dl), and the number of lobes involved were also associated with mortality. Patients receiving standard therapy (penicillin, ampicillin, erythromycin, or cephalosporins) had lower mortality. Of the previously specified risk factors for mortality, only age, whether standard therapy was administered, the number of lobes involved, and the serum creatinine level proved to be independent risk factors according to logistic regression. CONCLUSIONS: The overall mortality from pneumococcal bacteremia has not decreased during the past 40 years. Risk factors associated with increased mortality were identified. Prevention by immunization with polyvalent pneumococcal polysaccharide vaccine should be practiced more widely.

Pulmonary vascular protein sieving capability after exposure to high vascular pressures.

We evaluated the ability of the canine in situ left lower lobe (LLL) vasculature to sieve endogenous plasma proteins of various molecular radii (34-124 A) after LLL arterial pressure had been transiently elevated to 23.8 +/- 0.9 (control group, n = 5) or 92.3 +/- 1.4 (SE) Torr (high-pressure group, n = 9) by restricting LLL venous outflow under conditions of constant flow. After LLL flow was returned to natural perfusion, left atrial pressure was elevated in step increments, and LLL lymph and blood samples were collected until filtration-independent lymph-to-plasma protein concentration ratios (CL/CP) were obtained. The osmotic reflection coefficients (sigma d) for total proteins and seven protein fractions (separated by gradient gel electrophoresis) were calculated. The average total protein sigma d of the high-pressure group [0.51 +/- 0.06 (SE)] was significantly lower than that of the control group (0.68 +/- 0.03). Several LLLs of the high-pressure group, however, exhibited normal sigma d's. Protein fraction CL/CP's decreased with increasing molecular radius in both groups, but the CL/CP-molecular radius relationship was displaced upward in the high-pressure group. Pore analysis suggested that the decreases in sigma d could be explained by increases in the fractional flow through a large-pore system.