LEFT-VENTRICULAR MAXIMAL SYSTOLIC ELASTANCE CALCULATED BY A COMBINATION OF M-MODE ECHOCARDIOGRAPHY AND STANDARD MANOMETRY

1. A method for obtaining the end-systolic left ventricular (LV) pressure-diameter and stress-diameter relationships in man was critically analyzed.2. Pressure-diameter and stress-diameter relationships were determined throughout the cardiac cycle by combining standard LV manometry with M-mode echocardiography. Nine adult patients with heart disease and without heart failure were studied during intracardiac catheterization under three different conditions of arterial pressure, i.e., basal (B) condition (mean +/- SD systolic pressure, 102 +/- 10 mmHg) and two stable states of arterial hypertension (H(I), 121 +/- 12 mmHg; H(II), 147 +/- 17 mmHg) induced by venous infusion of phenylephrine after parasympathetic autonomic blockade with 0.04 mg/kg atropine.3. Significant reflex heart rate variation with arterial hypertension was observed (B, 115 +/- 20 bpm; H(I), 103 +/- 14 bpm; H(II), 101 +/- 13 bpm) in spite of the parasympathetic blockade with atropine. The linear end-systolic pressure-diameter and stress-diameter relationships ranged from 53.0 to 160.0 mmHg/cm and from 97.0 to 195.0 g/cm3, respectively.4. The end-systolic LV pressure-diameter and stress-diameter relationship lines presented high and variable slopes. The slopes, which are indicators of myocardial contractility, are susceptible to modifications by small deviations in the measurement of the ventricular diameter or by delay in the pressure curve recording.

EFFECT OF AN LH-RH ANALOG ON CAT TESTIS AND ADRENAL-CORTEX FUNCTION

The LH-RH analog LH-RH-A (des-Gly10,[D-Trp6]-LH-RH ethylamide) was administered in pharmacological doses (20-mu-g/kg, sc) to adult male cats for 15 days and its effect on testis and adrenal function was determined. Daily administration of the analog promoted a 3-fold increase in plasma testosterone levels after 7 days, indicating a stimulatory effect of LH-RH-A (mean +/- SD for 6 treated cats, 1.88 +/- 0.35 vs 0.51 +/- 0.08 ng/ml for 6 control cats). After 15 days the LH-RH-A-treated group exhibited a similar plasma testosterone concentration as the control group (mean +/- SD, 0.96 +/- 0.35 ng/ml vs 0.88 +/- 0.39 ng/ml, respectively), similar testicular and adrenal weights and no significant differences in the spermatogenic process. However, semiquantitative analysis of the zona fasciculata of the adrenals from the LH-RH-A-treated group showed a significant accumulation of a substance not stained by hematoxylin-eosin or Schiff periodic acid (mean +/- SD of index of accumulation was 3.50 +/- 0.4 for treated cats vs 2.20 +/- 0.3 for control cats). The present results show that pharmacological doses of LH-RH-A have an effect on the adrenal cortex of cats without modifying spermatogenesis or plasma testosterone levels.

PARTICIPATION OF OPIOID RECEPTORS IN THE MODULATION OF THE ANALGESIC RESPONSE BY ADRENAL AND GONADAL GLANDS

The involvement of opioid receptors in the analgesic response was evaluated by the tail-immersion test in simultaneously adrenalectomized and ovariectomized female Wistar rats (210-250 g). The reaction time (mean +/- SEM) for tail withdrawal from hot water decreased significantly 2 weeks after surgery (3.52 +/- 0.20 s) when compared to intact animals (6.09 +/- 0.23 s). Hormonal replacement with dexamethasone (50-mu-g/day) did not affect reaction time (3.38 +/- 0.19 s). However, this response was restored by combined adrenal and gonadal steroid substitution (estradiol 5-mu-g/day and progesterone 1.5-mu-g 6 h before the tests) therapy (5.11 +/- 0.45 s in animals treated with dexamethasone plus estradiol and 5.04 +/- 0.43 s in animals treated with dexamethasone plus estradiol plus progesterone). Naloxone (2 mg/kg) decreased the reaction time of animals treated with adrenal and gonadal steroids (5.11 +/- 0.45 vs 4.15 +/- 0.44 s and 5.04 +/- 0.43 vs 3.87 +/- 0.28 s, respectively, before and after naloxone) but failed to decrease it in rats treated with dexamethasone only (3.88 +/- 0.18 vs 4.34 +/- 0.25 s, before and after naloxone). These observations indicate that gonadal steroids are the most important steroid factors involved in the reaction time to tail immersion in hot water and confirm other reports that the opioid pathways modulating the neuronal circuitry require the presence of these hormones.

LEFT-VENTRICULAR MASS ESTIMATED BY M-MODE ECHOCARDIOGRAM IS NOT ALTERED BY CHANGES IN CARDIAC SHAPE AND DIMENSIONS DUE TO ACUTE ARTERIAL-HYPERTENSION

The effect of changes in left ventricular (LV) shape and dimensions due to acute arterial hypertension induced by mechanical obstruction of the aorta for 10 min on LV mass values estimated by M-mode echocardiogram was studied in 14 anesthetized dogs. Although the systolic pressure increased from 117.5 +/- 19.9 to 175.4 +/- 22.9 mmHg altered ventricular diameter from 2.77 +/- 0.49 cm to 3.17 +/- 0.67 cm (P<0.05) and wall thickness from 0.83 +/- 0.09 to 0.75 +/- 0.09 cm (P<0.05), LV mass estimated before (73.5 +/- 19.1 g) and after (78.3 +/- 26.4 g) hypertension was not significantly different. We demonstrate here for the first time that changes in LV dimensions induced by acute arterial hypertension do not modify LV mass values estimated by the M-mode electrocardiogram method.

DETECTION OF INFECTIOUS-DISEASE AGENTS IN TISSUE BY IMMUNOCYTOCHEMISTRY

1. Immunocytochemical procedures have played an increasingly larger role in the identification of infectious disease agents in tissue sections owing to the increased availability and specificity of antibody reagents, the great sensitivity of the methods, and the relative facility with which the studies are performed.2. Immunocytochemical methods can be applied to routine formalin-fixed tissue for the detection of infectious agents such as viruses, bacteria, fungi, and protozoa among other microorganisms for diagnostic and research purposes.