Effects of Ca2+ antagonist, nicardipine, on experimental asthma with special reference to slow reacting substance of anaphylaxis

Slow reacting substance of anaphylaxis (SRS-A) is an important chemical mediator of bronchial asthma. Leukotriene C4 is a component of SRS-A and is synthesized from arachidonic acid. Its synthesizing and releasing processes are found to be Ca2+-dependent. We developed an in vivo inhalation asthma model, mainly mediated by SRS-A, and elucidated the relationship between a Ca2+-antagonist, nicardipine, and SRS-A. In the asthmatic model, mediated by endogenous SRS-A induced by antigen inhalation, continuous intravenous infusion of nicardipine 7 micrograms/kg/min depressed the open airway pressure by about 60% compared with the saline-treated group. Inhibition of mean pulmonary resistance (RL) was about 50% and that of the inverted value of dynamic compliance (1/Cdyn) about 36%. However, the same concentration of nicardipine did not significantly effect the airway response in the asthmatic model induced by the inhalation of leukotriene C4. These results suggest that nicardipine, at the concentration used in the present study. did not block the direct effect of SRS-A on the smooth muscle, but blocked the Ca2+ influx required for the synthesis of SRS-A and its release.

A cause of discrepancy between values for urinary protein as assayed by the Coomassie Brilliant Blue G-250 method and the sulfosalicylic acid method

In simultaneous assays of urinary proteins by the Coomassie Brilliant Blue G-250 (CBB) and the sulfosalicylic acid (SSA) methods, we noticed that about 18% of samples showed about twice higher protein values by the former method than by the latter. Some urinary proteins are soluble in SSA and react with CBB. Examinations with sodium dodecyl sulfate/polyacrylamide gel electrophoresis showed that these proteins migrated in 13 protein bands having relative molecular masses ranging from 15 000 to 230 000. The protein corresponding to the most intensely stained band in urine samples from the patients studied (with malignant tumors, renal disorders, etc.) had an Mr of 45 000; that in the pattern for healthy subjects had an Mr of 94 000. The former was identified as alpha 1-acid glycoprotein, the latter as Tamm-Horsfall mucoprotein.

A cause of discrepancy between values for urinary protein as assayed by the Coomassie Brilliant Blue G-250 method and the sulfosalicylic acid method

In simultaneous assays of urinary proteins by the Coomassie Brilliant Blue G-250 (CBB) and the sulfosalicylic acid (SSA) methods, we noticed that about 18% of samples showed about twice higher protein values by the former method than by the latter. Some urinary proteins are soluble in SSA and react with CBB. Examinations with sodium dodecyl sulfate/polyacrylamide gel electrophoresis showed that these proteins migrated in 13 protein bands having relative molecular masses ranging from 15 000 to 230 000. The protein corresponding to the most intensely stained band in urine samples from the patients studied (with malignant tumors, renal disorders, etc.) had an Mr of 45 000; that in the pattern for healthy subjects had an Mr of 94 000. The former was identified as alpha 1-acid glycoprotein, the latter as Tamm-Horsfall mucoprotein.

[Right ventricular dysplasia: clinical features compared with dilated cardiomyopathy]

Five patients with right ventricular dysplasia (RVD) and 28 patients with predominantly left sided dilated cardiomyopathy (DCM) were studied. RVD was characterised by syncope, recurrent sustained ventricular tachycardia, which typically had a left bundle branch block pattern on the surface electrocardiogram, right heart failure, and faint or absence of the right ventricular free wall on the myocardial scintigraphy. Two-dimensional echocardiographic, radionuclide angiographic, and contrast ventriculographic studies were typical of the right ventricular abnormalities in both Uhl's anomaly and arrhythmogenic right ventricular dysplasia. Two of them were died suddenly. Pathologic examinations showed "parchment-like" thinning of portions of the right ventricular free wall and its replacement by adipose tissue, although such degenerations were not found in the septum and the left ventricle. By contrast, DCM was characterised by exertional dyspnea and short run ventricular tachycardia, most of which had a right bundle branch block pattern. Ten of them had left ventricular myocardial defects on the scintigraphy, of whom five died suddenly. Hemodynamic data showed that left ventricular dysfunction was predominant more than right ventricle. Thus we postulate that these two syndromes are manifestations of a congenital, pathophysiologic process - the "involved right or left ventricle" syndrome.

[Giant aneurysm of the right coronary artery with complete proximal obstruction: a case report]

A 46-year-old woman was admitted to our hospital for evaluation of oppressive chest pain and ECG abnormalities. Her ECG on admission showed old inferior myocardial infarction. Chest radiography on admission indicated cardiomegaly (cardiothoracic ratio was 60%). The echocardiogram showed compression of the right atrium, right ventricle, and tricuspid annulus by a tumor which was located between the liver and the heart. The tumor's echo density was heterogenous. Cardiac computed tomography showed compression of the tricuspid annulus by the tumor which was located anterior to the right atrium and the right ventricle. The tumor registered 65.1 HU and was not enhanced by contrast medium. These findings strongly suggested a giant right coronary aneurysm filled with thrombus, and this diagnosis was confirmed at surgery and pathologically. Coronary aneurysms are rarely diagnosed during life, and usually are incidental findings during coronary arteriography performed to evaluate myocardial infarction or angina pectoris. The coronary aneurysm of the present case was clearly and easily recognized using computed tomography and appeared as a pericardial tumor. Computed tomography may be helpful for observing the growth of tumor and thrombus formation within it.

Alterations in myocardial perfusion during painless ST-segment depression in patients with angina pectoris

In order to determine whether painless ST changes represent myocardial ischemia, we studied regional myocardial perfusion in patients with angina pectoris who showed painless ST-segment depression during a treadmill exercise test. Twenty-one patients were evaluated by myocardial imaging using thallium-201 injected intravenously during exercise when painless ST-segment depression was evident. The same examination was repeated in 5 of the above patients when they showed ST-segment depression with chest pain. Myocardial images obtained during painless ST-segment depression revealed perfusion defects in 15 of 21 patients (71%). Images obtained during ST-segment depression with chest pain showed perfusion defects in all 5 patients (100%) including 3 patients who demonstrated no defects during painless ST-segment depression. In these 5 patients, the ST-segment depression associated with pain was significantly greater than that without pain (3.4 +/- 1.1 vs 2.1 +/- 1.1 mm, p less than 0.01). These results suggest that the majority of episodes of painless ST-segment depression occurring during exercise are accompanied by regional myocardial perfusion abnormalities and that transient painless ST-segment depression in patients with angina pectoris might represent less severe myocardial ischemia.

Relationship between lipids and angiographically defined coronary artery disease in Japanese patients

The relationship between the severity and extent of coronary artery disease (CAD) and the lipid profiles was evaluated in 120 Japanese male patients, who underwent coronary angiography. Analysis of the lipid quartile distribution showed that the percentage of patients with significant CAD increased as the total cholesterol (TC) increased and high-density lipoprotein cholesterol (HDL-C) decreased. In addition, as the number of vessels with marked coronary artery stenosis increased, TC and TC/HDL-C increased while HDL-C decreased. However, within this population, triglyceride level, high blood pressure, and smoking were not significantly associated with coronary angiographic findings.

[Atrial septal defect associated with an abnormal chamber of the right ventricle: report of a case]

A case of atrial septal defect associated with an abnormal chamber behind the right ventricle, which was heretofore undescribed, was reported. A 41-year-old woman was admitted to our hospital for the evaluation of a heart murmur. A Levine 3/6 ejection systolic murmur and a fixed splitting of the second heart sound were audible. Two-dimensional echocardiography disclosed an atrial septal defect and an abnormal chamber behind the right ventricle. This accessory chamber communicating with the right atrium was separated from the right ventricle by a membranous structure. The motion of this membrane showed a wide excursion just like that of the atrio-ventricular valve. On the M-mode echocardiogram, the anterior tricuspid leaflet and this membrane were recorded simultaneously without intervening septal echoes and this finding was very similar to that obtained in the single ventricle. Cardiac catheterization revealed that the pressure pattern in the abnormal chamber was that of the right atrium but its intracardiac electrocardiogram showed a right ventricular pattern. The complex morphological aspect of this case was confirmed by angiography and surgery. The developmental process of this very unusual anomaly is not clear, but it may be a kind of congenital anomaly related to Ebstein's anomaly.

[Grading of tricuspid regurgitation by pulsed Doppler echocardiography and liver function tests]

Recently, pulsed Doppler echocardiography has been used for the quantitative evaluation of tricuspid regurgitation (TR). However, there are some problems about the clinical significance of TR diagnosed by Doppler examination probably because of the excellent sensitivity in detecting TR. In the present study, we used liver function tests as an indicator of the visceral damage caused by TR and compared them to the severity of TR estimated by Doppler examination. Forty Doppler examinations were performed in 33 cardiac patients including seven, in which the examinations were repeated because the severity of TR changed during the clinical course. The severity of TR was classified into four grades according to the maximal extent of the regurgitant signal. Abnormal liver function was defined by the abnormalities of at least one of the following six tests: cholinesterase (CHE), gamma-GTP, leucine aminopeptidase (LAP), total bilirubin, alkaline phosphatase and GPT. Abnormal liver function tests were present in one of eight patients without TR, two of 10 with 1 + TR, four of seven with 2 + TR, seven of eight with 3 + TR, and six of seven with 4 + TR. The incidence of abnormal liver function tests increased parallel to the grade of TR and was very frequent in patients with 3 + or 4 + TR. TR diagnosed as greater than 3 + by Doppler examination is considered to have an important clinical significance and an indication of the intensive therapy.

Myocardial perfusion and left ventricular performance during exercise-induced ST-segment depression in apparently healthy subjects

Ischemic-like ST-segment depression seen during exercise in apparently healthy subjects has previously been noted, but the cause of this change is unknown. The aim of this study was to investigate the pathophysiology of this electrocardiographic change. Ten healthy subjects who developed an electrocardiographic "ischemic" pattern of ST change during treadmill exercise testing were studied. All subjects underwent both thallium-201 myocardial perfusion imaging and radionuclide angiocardiography at rest and during exercise at a time when abnormal ST changes appeared, and demonstrated a normal homogeneous pattern of thallium-201 distribution on both rest and exercise images. Overall, left ventricular ejection fraction rose from 0.60 +/- 0.06 (mean +/- SD) at rest to 0.65 +/- 0.07 with exercise. None of the subjects had regional wall motion abnormalities at rest or during exercise. These results are different from the findings observed in patients with coronary heart disease and angina pectoris in whom regional abnormalities in both perfusion and left ventricular performance have been noted during exercise. Therefore it would seem that myocardial ischemia is not likely to be a tenable explanation for the electrocardiographic "ischemic" changes in these apparently healthy subjects.

[An application of X-ray computed tomography for complex cardiac anomalies]

X-ray computed tomography (CT) was performed in two patients with complex congenital heart disease in order to assess the clinical utility in the systemic morphological diagnosis. A Somotom 2 whole body CT scanner (Siemens Co) was used, and contrast enhanced CT scanning and a dynamic CT scanning were performed in one case (Case 2).; Case 1: A 20-year-old female with double outlet right ventricle (S, D, L), pulmonary stenosis and aortic insufficiency. The CT revealed a viscero-atrial situs, ventriculoarterial relation, spatial interrelationship between the great arteries and a run of the stenotic pulmonary artery. The CT clarified spatial relationship among four cardiac chambers, ventricular septal defect and great arteries, contributing to the understanding of the complex cardiac structure. Case 2: A 26-year-old female with single ventricle (III-C solitus), pulmonary stenosis, dextroversion, left superior vena cava and WPW syndrome. The CT documented precisely a viscero-atrial situs, dextroversion, ventriculoarterial relation, spatial interrelationship between the great arteries, stenotic main and left pulmonary arteries and a dilated right pulmonary artery due to the right Blalock-Taussig operation performed 15 years before. A diagnosis of left superior vena cava could be made by CT, and its flow into coronary sinus was visualized by dynamic CT. The dynamic CT also clarified a mixing of venous and arterial blood in the common ventricle, and revealed a rudimentary ventricular septum. Thus, the CT serves useful purposes especially as examination of viscero-atrial situs, ventriculoarterial relation and spatial interrelationship between great arteries, and anomalies of the mediastinal vessels. Furthermore the relationship among four cardiac chambers, ventricular septal defect, and the pattern of blood flow were also clarified. However, the CT failed to define the state of a ventricular loop, because it could not identify ventricular muscular structures and atrioventricular valves as these move rather vigorously. The CT could not locate pulmonary stenosis, valvular or somewhere else. The CT seemed to be a promising noninvasive method in the systemic morphological diagnosis of congenital heart disease as subsidiary to echocardiographic investigation. However, in pediatric patients, it seemed considerably hard to obtain clear cardiac CT images because of the difficulty in halting respiration during procedure.

Measurements of cytoplasmic and vacuolar pH in Neurospora using nitrogen-15 nuclear magnetic resonance spectroscopy

The nitrogen-15 chemical shift of the N1 (tau)-nitrogen of 15N-labeled histidine and the half-height line widths of proton-coupled resonances of the delta- and omega,omega'-nitrogens of 15N-labeled arginine and of the alpha-nitrogens of 15N-labeled alanine and proline were measured in intact mycelia of Neurospora crassa to obtain to estimates of intracellular pH. For intracellular 15N-labeled histidine, the N1 (tau)-nitrogen chemical shift was 200.2 ppm. In vitro measurements showed that the chemical shift was slightly affected by the presence of phosphate, with which the basic amino acids may be associated in vivo. These considerations indicate a pH of 5.7-6.0 for the environment of intracellular histidine. The half-height line widths of the delta- and omega,omega'-nitrogens of [15N]arginine were 15 and 26 Hz, respectively. In vitro studies showed that these line widths also are influenced by the presence of phosphate, and, after suitable allowance for this, the line widths indicate pH 6.1-6.5 for intracellular arginine. The half-height line widths for intracellular alanine and proline were 17 and 12 Hz, respectively, which are consistent with an intracellular pH of 7.1-7.2. Pools of histidine and arginine are found principally in the vacuole of Neurospora, most likely in association with polyphosphates. Proline and alanine are cytoplasmic. The results reported here are consistent with these localizations and indicate that the vacuolar pH is 6.1 +/- 0.4 while the cytoplasmic pH is 7.15 +/- 0.10. Comparisons of these estimates with those obtained by other techniques and their implications for vacuolar function are discussed.

Effect of the nitrogen source on glutamine and alanine biosynthesis in Neurospora crassa. An in vivo 15N nuclear magnetic resonance study

The influences of different nitrogen sources on the relative rates of biosynthesis of glutamine and alanine have been studied by 15N nuclear magnetic resonance spectroscopy of intact Neurospora crassa mycelia suspensions. The rate of glutamine synthesis was fastest after growth in media deficient in free ammonium ion, whereas it was slowest following growth in media containing both glutamic acid and glutamine. The reverse trend was observed for the biosynthesis of alanine. A competition between the two biosynthetic pathways for the same substrate, glutamic acid, was found to limit the rate of alanine synthesis when glutamine synthesis was rapid. The observed in vivo rates of these reactions are compared to the reported specific activities of the enzymes catalyzing the reactions, and implications of these results for nitrogen regulation of these pathways under various physiological conditions are discussed.

Nitrogen-15 spin-lattice relaxation times of amino acids in Neurospora crassa as a probe of intracellular environment

The nitrogen-15 spin-lattice relaxation time, T1, and the nuclear Overhauser enhancement (NOE) have been measured for intracellular glutamine, alanine, and arginine in intact Neurospora crassa mycelia to probe their various intracellular environments. The relaxations of 15N gamma of glutamine, 15N alpha of alanine, and 15N omega, omega ' of arginine in N. crassa were found, on the basis of their NOE values, to be predominantly the result of 15N-H dipolar relaxation. These relaxations are therefore related to the microviscosities of the various environments and associations of the respective molecules with other cellular components that act to increase the effective molecular sizes. For 15N gamma of glutamine in the cytoplasm, the intracellular T1 (4.1 s) was only slightly shorter than that in the culture medium (4.9 s). This indicates that the microviscosity of the cytoplasm surrounding the glutamine molecules is not much greater than 1.3 cP. By contrast, for 15N omega, omega ' of arginine, which is sequestered in vacuoles containing polyphosphates, the intracellular T1 (1.1 s) was only one-fourth of that in the medium (4.6 s). In model systems, the T1 of 15N omega, omega ' in a 1 M aqueous solution of arginine containing 0.2 M pentaphosphate was 0.95 s, whereas in an isoviscous (2.8 cP) solution without pentaphosphate, the T1 was 1.8 s. These results suggest either that the vacuolar viscosity is substantially above 2.8 cP or that the omega, omega '-nitrogens of vacuolar arginine are associated with a polyanion, possibly polyphosphate. The implications of these results for the properties of the vacuolar interior are discussed in relation to the mechanism of amino acid compartmentation.

Nitrogen-15 nuclear magnetic resonance of arsanilazotyrosine-248 carboxypeptidase A and its complex with beta-phenylpropionate. Structure and dynamics in solution

Nitrogen-15 nuclear magnetic resonance has been used to study the structure of arsanilazocarboxypeptidase A and its complex with the inhibitor beta-phenylpropionate. Derivatives selectively enriched with 15N were prepared to facilitate observation of the 15N resonances. The results are consistent with the conclusions reached previously from absorption spectroscopic studies and, in addition, provide new information regarding the properties of the azoenzyme and its inhibitor complex. Direct evidence has been obtained for formation of an intramolecular complex between the catalytically essential zinc ion and azoTyr-248, and it has been possible to estimate the degree of complexation. Moreover, the zinc complex involves the distal (N beta) nitrogen of the azo linkage, whereas a model compound, tetrazolyl-N-acetyltyrosine, complexes to zinc through the proximal (N alpha) nitrogen. The 15N NMR spectra give specific information regarding the intramolecular hydrogen bonding in the azoenzyme. The free azophenol form of the azoenzyme, like that of the model compound arsanilazo-N-acetyltyrosine, exists predominantly with the tyrosine phenolic proton intramolecularly hydrogen bonded to N beta of the azo linkage to form a six-membered ring structure. A similar hydrogen bond is also present in the apoazoenzyme and in the azoenzyme-Gly + L-Tyr) complex, but not in the complex between the azoenzyme and beta-phenylpropionate. In the latter complex, there appears to be a new and strong hydrogen bond between the phenolic proton of Tyr-248 and the carboxylate group of enzyme-bound beta-phenylpropionate. Thus, azoenzyme-bound beta-phenylpropionate, but not azoenzyme-bound Gly + L-Tyr, is apparently able to compete effectively with, and displace, the azo nitrogen as the hydrogen-bond acceptor of the phenolic proton of Tyr-248.

Potentiation of toxicity and positive inotropic effect of ouabain by furosemide in guinea pig heart

The present study was undertaken to elucidate the potentiation by furosemide of toxicity and positive inotropic effect of ouabain in guinea pigs. Arrhythmogenic responses to ouabain as well as the lowering of its lethal dose were potentiated by pretreatment with furosemide in guinea pigs. The potentiation of ouabain toxicity after furosemide administration was inhibited by pretreatment with potassium sparing diuretic, prorenoate. Furosemide-induced potentiations of contractile force and arrhythmogenic effect of ouabain were also observed in isolated guinea pig papillary muscle. However after pretreatment with furosemide, ouabain produced arrhythmias without any significant changes in either left ventricular or subcellular fractions binding of 3H-ouabain in guinea pigs. These findings suggest that furosemide-induced potentiation of ouabain toxicity is at least in part associated with the decreased intracellular potassium content of guinea pig heart. It was also demonstrated that the positive inotropic action induced by subtoxic dose of ouabain was potentiated by furosemide in guinea pig papillary muscle preparation.

Conditions for "coronary steal" caused by coronary vasodilator in man

This study was undertaken to assess the conditions necessary to cause the "coronary steal" phenomenon in human subjects. We studied 42 patients (36 males, 6 females, ages 27--70 years) with known or suspected coronary artery diseases using continuous monitoring of the changes in blood pressure and electrocardiogram, thallium-201 myocardial imaging and selective coronary arteriography. Dipyridamole in a dose of 0.4 mg/Kg was given as an intravenous infusion for 4 min and thallium-201 was injected at the 4th minute after completion of the dipyridamole infusion. None of the 20 patients without significant coronary artery disease complained of anginal chest pain or showed ischemic S-T segment depression. Dipyridamole images showed no perfusion abnormalities in 17 of the 20 patients. On the other hand, in 4 of the 22 patients with significant coronary artery disease, anginal chest pain accompanied with S-T segment depression occurred after the dipyridamole infusion. Dipyridamole images showed perfusion abnormalities in 18 of the 22 patients. The 4 patients who experienced an anginal attack had 3 vessel disease on the coronary arteriogram and showed regional perfusion defects on scintigrams corresponding to the regions receiving collaterals. Before the onset of pain, the double product (heart rate X systolic arterial pressure) was unchanged significantly but there was a reduction in the systemic blood pressure. The overall data exhibit the following conditions under which attacks of angina pectoris are induced by dipyridamole: 1) the presence of multiple vessel disease, 2) a fall in systemic blood pressure, and 3) regional malperfusion caused by dipyridamole.

15N NMR studies of nitrogen metabolism in intact mycelia of Neurospora crassa

Suspensions of intact mycelia of Neurospora crassa grown in medium containing 15NH4Cl have been found to give well-resolved 15N nuclear magnetic resonance spectra for metabolites that play crucial roles in intermediary nitrogen metabolism. These include the amide nitrogen of glutamine, the alpha-amino nitrogens of glutamate and other amino acids, the guanidino nitrogens of arginine, the ureido nitrogen of citrulline, the side-chain nitrogens of ornithine or lysine, or both, and uridine diphosphates. The turnover time of glutamine in vivo was estimated to be less than 1 hr by using nuclear magnetic resonance spectroscopy in conjunction with tracer methodologies. Applications of these techniques to the study of nitrogen metabolism are discussed.

Influence of running pace upon performance: effects upon oxygen intake, blood lactate, and rating of perceived exertion

Three different techniques of middle distance running (fast/slow, slow/fast, and steady pace) have been compared in terms of oxygen intake, blood lactate and ratings of perceived exertion (RPE). The subjects (10 middle distance and long distance male runners) carried out the three patterns of running on the laboratory threadmill according to a randomly ordered sequence, on each occasion covering 1400 m in 4 min. The fast/slow protocol resulted in a rapid and sustained on-transient of oxygen intake, less lactate accumulation, and a lower rating of perceived exertion during the final 2 min of th4 min run. Physiological data thus support coaching impressions of the superiority of the fast/slow protocol.

[Effect of furosemide on ouabain toxicity in guinea pigs (author's transl)]

An attempt was made to study the effect of furosemide on the toxic and lethal dose (LD) of ouabain. Ouabain was infused continuously in guinea pigs anesthetized with urethane. The toxic dose of ouabain was determined by the minimal dose which produced ventricular arrhythmias. The LD of ouabain was 300.8 +/- 13.8 microgram/kg (mean +/- SE) in control guinea pigs. When furosemide was administered in a dose of 2 mg/kg i.v. prior to ouabain, this was significantly decreased to 225.2 +/- 14.1 microgram/kg (P less than 0.01). Furosemide-treated guinea pigs also showed a marked decrease in toxic dose of ouabain. In another series of experiment, the ouabain uptake by the heart and its subcellular fraction were determined by the infusion of 3H-ouabain at a constant rate under the same experimental conditions aforementioned. Approximately 30% decrease in the LD of 3H-ouabain was also observed in the furosemide pretreated guinea pigs. 3H-ouabain concentration in blood, cardiac muscles and microsomal fraction were lower than control group. These findings suggest that potentiation of ouabain toxicity produced by furosemide is not associated with increased cardiac ouabain uptake, but with increased sensitivity at the site of action.