[Effects of exercise on mitral regurgitation in healthy subjects]

Transthoracic echocardiography including color Doppler echocardiography and graded exercise (supine bicycle ergometer) were performed to examine both the changes of mitral regurgitation (MR) flow during exercise and the effects of cathecholamine on the MR flow in 20 young males (mean age 19 years) and 9 male long-distance runners (mean age 20 years) with presumably normal hearts. MR flow was detected in 13 of the 20 young males at rest. The severity of MR was mild in 12 subjects, and moderate in 1. After exercise, MR flow vanished in 4 of the 13 subjects (group B). In the other nine subjects, MR flow lasted during and after exercise (group A). In the seven subjects without MR flow at rest, MR flow did not appear during and after exercise (group C). Group A had significantly lower left ventricular ejection fraction than group C at rest (A 64.9 +/- 4.25%, B 69.4 +/- 4.32%, C 73.9 +/- 3.46%; p < 0.05). However, no significant differences were observed in other echocardiographic parameters (including left ventricular end-diastolic dimension, mitral annulus diameter and left atrial diameter), heart rate and serum cathecholamine levels between the three groups before and after exercise. In the nine male long-distance runners, MR flow was detected in six of nine subjects at rest. The severity of MR was mild in all subjects. After exercise, MR flow vanished in two of these six subjects (group A). In the other four subjects, MR flow lasted during and after exercise (group B). In three subjects without MR flow at rest, MR flow did not appear during and after exercise (group C). There were no significant differences in echocardiographic parameters, heart rate and serum cathecholamine levels between the three groups before and after exercise. These data suggest that MR flow detected in healthy subjects correlates with tension and contractility of papillary muscle.

Effects of ajmaline on non-sodium ionic currents in guinea pig ventricular myocytes

The lack of currently available data stimulated us to investigate the electrophysiological effects of ajmaline, a classical class Ia antiarrhythmic agent, on various currents responsible for the action potential plateau and repolarization phases. The whole cell patch clamp recording technique was applied to guinea pig ventricular myocytes. Ajmaline suppressed the Ca2+ current (Ica) in a dose-dependent manner (Kd = 1.2 x 10(-5) M) without affecting the steady-state inactivation kinetics and the voltage dependency of the current-voltage relationship. Ajmaline inhibited the inward portion of the inward rectifying K+ current (IKl). Ajmaline decreased the delayed rectifier K+ current (IK) without altering the activation or deactivation time courses. All these inhibitory effects of ajmaline prolonged the action potential duration in a dose dependent manner. The inhibitory actions of ajmaline on the action potential upstroke and various currents responsible for the plateau and repolarization may contribute to the observed suppression of depolarization-induced abnormal automaticities by this agent.

[Interferon therapy after ablation of Kent bundle for a patient with chronic hepatitis type B complicated with WPW syndrome]

Cardiotoxicity of interferon-alpha or gamma, such as fatal arrhythmia and myocardial infarction, has been reported. Therefore cardiotoxicity of interferon should be seriously considered before administration for patients with a pre-existing heart disease. We treated a patient with chronic active hepatitis type B, coexisted with Wolff-Parkinson-White syndrome, who has had frequent attacks of paroxysmal atrial fibrillation. To prevent the occurrence of fatal arrhythmia with an interferon therapy in this patient, we performed radiofrequency catheter ablation of the Kent bundle. After the successful ablation, we could safely administered recombinant interferon alpha-2b for chronic hepatitis type B.

Magnetic resonance imaging of human spinal cord infarction

Magnetic resonance images obtained in two cases of spinal cord infarction are described: one with hemorrhagic thoracic cord infarct, the other with ischemic cervical cord infarct with sequential magnetic resonance imagings. An enlarged cord with strand-shape or longitudinal hypointensity on both T1- and T2-weighted images was noticed in the hemorrhagic infarct; hypointensity on the T2-weighted image was thought to be due to hemosiderin, which shortens T2 relaxation. In the ischemic infarct, a small, round area of hypointensity on T1-weighted images, and of hyperintensity on T2-weighted images, noted 9 hours postictus ("early infarct") changed on the 22nd day to a cephalocaudal strandlike hypointensity on T1-weighted image, which was enhanced by Gd-DTPA. The hypointensity suggested "pencil-like softening" in "medium" age infarct. On postictal day 49, it showed an extensive homogeneous hypointensity involving several segments of the cord on T1-weighted images and hyperintensity on T2-weighted images with negative Gd-DTPA enhancement suggesting "late transverse infarct." We considered that these changes are of value in diagnosing spinal cord infarcts on magnetic resonance imagings.

[DAPI-DNA cytofluorometric study of glioma cells--application of DAPI-DNA cytofluorometry to paraffin embedded archival glioma tissue for nuclear DNA content analysis]

Using DAPI-DNA cytofluorometry, the author analyzed nuclear DNA content of formalin fixed, paraffin embedded, glioma material obtained from 14 glioma cases at surgery. Sections of 10 microns were deparaffinized. Following simultaneous DAPI (4,6-diamidino-2-phenylindole dihydroporphyrin chloride)/HP (hematoporphyrin) staining, DAPI binds DNA and DNA-DAPI complexes emit blue fluorescence when exited by ultraviolet (UV) light. Through Zeiss fluorescence microscope, the author measured nuclear fluorescence intensity with histological verification of glioma cells. A DNA histogram was obtained with fluorescence intensity recorded on the abscissa and number of cells plotted on the ordinate. Samples of 20 normal non-neoplastic astrocytes taken from apparently normal brain tissue included in the histological slide were used as diploid (2 C) control. Based on DNA content, tumor cells were classified into 4 groups: N-group composed of cells with 2 C DNA content (normoploid), S-group with less than 2 C (hypoploid), L-group more than 4 C (hypertetraploid), I-group between 2 C and 4 C (intermediate ploidy). Intermediate ploidy was significantly higher and normoploid was significantly lower in glioblastoma compared with those of benign astrocytoma. Thus, DNA content and histological malignancy were well correlated. Due to limitation of measuring diaphragm of turret in the microscope, some extra large cell could not be included in it and was excluded from the measurement.(ABSTRACT TRUNCATED AT 250 WORDS)

In vitro comparison of the neuromuscular antinicotinic and intestinal antimuscarinic effects of different nondepolarizing muscle relaxants

The postsynaptic antimuscarinic properties of different nondepolarizing muscle relaxants were compared with their postsynaptic antinicotinic effect. d-Tubocurarine, pipecuronium and vecuronium were the most selective antagonists on postsynaptic nicotinic receptors. Gallamine, diadonium and Duador (RGH-4201) had relatively greater effect on postsynaptic muscarinic receptors. Therefore, much less side effect is expected to occur when pipecuronium, d-tubocurarine or vecuronium are used.

Heterogeneity of presynaptic muscarinic receptors located on different tissue preparations

Three different tissue preparations were used to demonstrate the heterogeneity of presynaptic muscarinic receptors that modulate neurotransmitter release. The presynaptic antimuscarinic potency of several muscarinic antagonists was characterized with the enhancement of the neurotransmitter release evoked by electrical stimulation on the guinea-pig ileum Auerbach plexus, the guinea-pig atrium and the rat brain cortex. Presynaptic muscarinic receptors located on the Auerbach plexus proved to be different of those present on the cortical cholinergic interneurons and on the sympathetic plexus of the guinea-pig atrium.

Levels of insulin-like growth factors I and II in human cord blood

Levels of insulin-like growth factors I and II (IGF-I and IGF-II) and somatomedin peptide content (SMPC) were measured in 32 normal term and 11 preterm infants. After acid chromatography to remove somatomedin-binding protein, SMPC was measured by placental membrane radioreceptor assay, while plasma IGF-I and II concentrations were measured by specific RIAs. SMPC levels in term infants were significantly below normal adult levels [0.49 +/- 0.13 (+/- SD) U/ml for infants compared to 1.30 +/- 0.25 U/ml for adult males]. IGF-I levels in term infants were also low, averaging 113 +/- 35 ng/ml for infants; the normal adult levels is 184 +/- 32 ng/ml. The IGF-II level was 282 +/- 84 ng/ml for infants and 687 +/- 169 ng/ml for adults. Both IGF-I and II levels in preterm infants were lower than those in term infants. IGF-I, and IGF-II, and SMPC levels showed a positive correlation with birth weight in term infants. Both IGF-I and IGF-II levels showed a strong positive correlation with gestational age in all infants.

Plasma Aluminum levels of patients on long term sucralfate therapy

Plasma aluminum levels of 17 patients with gastric and/or duodenal ulcers who had received four grams of sucralfate daily for eight to ten weeks were compared with those of six control subjects. Aluminum levels were determined by flameless atomic absorption spectrometry. Plasma of patients on long term sucralfate therapy contained 8.41 +/- 6.00 (SD) micrograms aluminum per liter and was not significantly different than that of the control subjects which contained 6.50 +/- 7.87 micrograms per liter. These values agreed well with normal values reported previously. In conclusion, long term ingestion of sucralfate in therapeutic doses does not result in an increase in plasma aluminum concentration.

Selective binding of sucralfate to gastric ulcer in man

Sucralfate is a basic aluminum salt of a sulfated disaccharide. In this study, patients with gastric ulcer were given oral multiple doses of sucralfate prior to partial gastrectomy, and binding of the drug to the ulcer lesion and to nonulcerated mucosa was estimated by chemical determination of aluminum and sulfated disaccharide. The ulcerated mucosa was found to contain, on the average, 6-7 times more sucralfate per square centimeter than the control mucosa (P less than 0.01 and less than 0.05 for aluminum and sulfated disaccharide, respectively). The high affinity of sucralfate for ulcerated mucosa, particularly the sucrose sulfate moiety, supports previous data that the beneficial effect of sucralfate in ulcer disease is due in part to complex formation between sucrose sulfate and proteins at the ulcer site.

Glucuronic acid pathway in alloxan diabetic rabbits. (I). Urinary excretion of metabolites related to the glucuronic acid pathway

Studies on the activity of the glucuronic acid pathway in alloxan diabetic rabbits were carried out. Amount of D-glucaric acid, L-ascorbic acid, and D-glucuronic acid in urine increased in the case of the alloxan diabetic rabbits. The transformation from D-glucuronolactone to D-glucaric acid was higher than normal in the diabetic animals. The expired 14-CO2 decreased and urinary excretion of labeled L-gulonic acid increased after administration of 6-14-C-glucuronolactone in the diabetic rabbits. L-Gulonic acid dehydrogenase, lactonase II, and beta-glucuronidase activities were reduced, and UDPGA-pyrophosphatase, D-glucuronic acid-1-phosphatase, and UDPGA-transferase activities increased in the diabetic rabbit liver. From these results, it may be concluded that an increase of endogenous D-glucuronic acid in the diabetic states could be attributed to a metabolid defect in the step of L-gulonic acid dehydrogenation and to the enhancement of UDPGA-pyrophosphatase and D-glucuronic acid-1-phosphate phosphatase activities.

Effect of D-glucaric acid derivatives on stability of rat liver lysosomes and erythrocytes

For studies on the lysosome-stabilizing effect of D-glucaric acid derivatives which have been found to have anti-inflammatory effect, the available and soluble enzyme activities of acid phosphatase of rat liver lysosomes were determined. Saliployed as standards. Lysosomes were incubated with drugs under specific conditions which allowed the data on the stabilizing activity of the drugs to be reproducible. The inhibitory effect of D-glucaro-1, 4-lactone, salicylic acid and phenylbutazone onover a wide range of concentrations. D-glucaro-1, 4-lactone as well as salicylic acid exhibited concentration-dependent lysosome-stabilizing effect whereas phenlybutazone had an optimum concentration for its lysosome-stabilizing effect. In addition, D-glucaro-1, 4-lactone,saliclicacid and phenylubtazone were also examined for their effects on heat-induced and saponin-induced hemolysis of rat erythrocyres. Both salicylic acid and phenylbutazone exhibited potent stabilziing and labilizing effects on heat-induced and saponin-induced hemolysis of eryhthrocytes, respectively. D-glucaro-1, 4-lactone, however, was incabale of affecting the hemolysis of erythrocytes. There appears to be a difference in the mechanism of the lysosome-stabilizing effects between D-glucaric acid derivatives and other anti-inflammatory drugs.