[Surgical treatment of primary cardiac tumors]

Twenty patients with primary cardiac tumors were operated on during the past ten years. The age of 15 female and 5 male patients ranged from 17 to 73 years. Eighteen patients had myxomas, 16 of which located in the left atrium and 2 in the right atrium. Systemic embolism occurred in 8 patients, subsequently caused cerebral infarction in 4, ischemia of extremities in 2, myocardial infarction in 1 and pulmonary infarction in 1. Emergency operation was performed in 5 patients because of severe congestive heart failure. In all cases, removal of myxoma was performed together with the excision of the wall to which the pedicle attached with the use of cardiopulmonary bypass. One patient with pulmonary infarction underwent resection of the infarcted lung simultaneously. Only one patient with severe heart failure died of pulmonary insufficiency one month after the operation. Another patient with cerebral infarction underwent clipping of cerebral aneurysm which appeared later in the infarcted area. The 17 patients including the latter patient showed a good recovery and no local recurrence during the follow-up period of 1 to 120 months. Two patients had malignant tumors, which were malignant fibrous histiocytoma of the left atrium and leiomyosarcoma of the pulmonary artery, respectively. Both of these rare tumors were resected noncuratively and led to the death because of their local recurrence with distant metastasis, though they received adjuvant chemotherapy. The symptoms, complications, diagnoses, surgical treatment and outcome of the primary cardiac tumors are reviewed in this study.

Diastereomers of neopterin and biopterin in human urine

A new pteridine compound, named umanopterin, was isolated from human urine both of cancer patients and non-cancer controls. The structure was confirmed to be 2-amino-4(3H)-oxo-6-[(1'R,2'R)-1',2',3'-trihydroxypropyl]pteridine , a diastereomer of neopterin. The amount of umanopterin relative to neopterin was about 10%, which was practically the same among the non-cancer controls and the patients of various cancers. A small amount of a threo diastereomer of biopterin, named orinapterin, was isolated from human urine for the first time. Its structure was shown to be 2-amino-4(3H)-oxo-6-[(1'S,2'S)-1',2'-dihydroxypropyl]pteridine. A non-enzymatic transformation of 7,8-dihydroneopterin and 7,8-dihydrobiopterin by a mechanism analogous to keto-enol tautomerism is postulated for the formation of umanopterin and orinapterin in human body.

Highly Sensitive, Specific Enzyme-Linked Immunosorbent Assay of Neopterin and Biopterin in Biological Samples

An enzyme immunosorbent assay of neopterin and biopterin on a polystyrene microtiter plate has been developed. A conjugate of neopterin or biopterin to bovine serum albumin was used to raise a specific antiserum against neopterin or biopterin in rabbits. An incubation mixture of the antiserum and samples prepared from human serum underwent another antigen-antibody reaction with the hapten fixed on the microtiter plate. The amount of antibody bound to the fixed hapten, which is inverse to the amount of hapten in the sample, was determined by using anti-rabbit IgG-horseradish peroxidase conjugate in a usual manner by measuring absorbance at 490 nm after reaction with o-phenylenediamine and hydrogen peroxide. The minimal detectable amounts of neopterin and biopterin were approximately 0.1 pmol. The specificity of the assay was so high that the assay system for neopterin completely distinguished it from biopterin, as judged from the cross-reaction of 0.002%, and vice versa. The amounts of neopterin and biopterin in human serum determined by the present method agreed well with those determined by high-performance liquid chromatography. We used the present method to determine the concentrations of neopterin in serum from healthy control subjects and patients with cancers and systemic lupus erythematosus; the results were consistent with literature data.

Alterations of urinary acetylcarnitine in valproate-treated rats: the effect of L-carnitine supplementation

Urinary excretion of acetylcarnitine was measured by high-performance liquid chromatography in two experimental groups of valproate-treated rats. In the urine of mature rats weighing 180 to 200 g treated with valproate (500 mg/kg/day), acetylcarnitine levels were higher than those in controls on days 4 and 7, while L-carnitine-supplemented rats showed lower levels than the valproate group. The valproate-treated rats showed an increased acetylcarnitine/acylcarnitine ratio on and after day 4, while the L-carnitine-supplemented rats showed no significant change compared to the controls on any days. In the urine of immature rats weighing 80 to 90 g treated with valproate (50 mg/kg/day), acetylcarnitine levels were increased after the 14th day of treatment. These results suggest that an increase in urinary acetylcarnitine occurs when small doses of valproate are administered for a longer time. We speculate that increased acetylcarnitine is not a product of beta-oxidation in mitochondria, because L-carnitine supplementation decreases the acetylcarnitine levels. Although the mechanism of acetylcarnitine excretion during valproate administration is not clear, L-carnitine supplementation is effective in decreasing the level of urinary acetylcarnitine and keeping the acetylcarnitine/acylcarnitine ratio normal.

Highly sensitive, specific enzyme-linked immunosorbent assay of neopterin and biopterin in biological samples

An enzyme immunosorbent assay of neopterin and biopterin on a polystyrene microtiter plate has been developed. A conjugate of neopterin or biopterin to bovine serum albumin was used to raise a specific antiserum against neopterin or biopterin in rabbits. An incubation mixture of the antiserum and samples prepared from human serum underwent another antigen-antibody reaction with the hapten fixed on the microtiter plate. The amount of antibody bound to the fixed hapten, which is inverse to the amount of hapten in the sample, was determined by using anti-rabbit IgG-horseradish peroxidase conjugate in a usual manner by measuring absorbance at 490 nm after reaction with o-phenylenediamine and hydrogen peroxide. The minimal detectable amounts of neopterin and biopterin were approximately 0.1 pmol. The specificity of the assay was so high that the assay system for neopterin completely distinguished it from biopterin, as judged from the cross-reaction of 0.002%, and vice versa. The amounts of neopterin and biopterin in human serum determined by the present method agreed well with those determined by high-performance liquid chromatography. We used the present method to determine the concentrations of neopterin in serum from healthy control subjects and patients with cancers and systemic lupus erythematosus; the results were consistent with literature data.

On the mechanism of papaverine inhibition of the voltage-dependent Ca++ current in isolated smooth muscle cells from the guinea pig trachea

The effects of papaverine, a smooth muscle relaxant agent, on the voltage-dependent Ca++ current were examined in isolated smooth muscle cells from the guinea pig trachea. The tight-seal whole cell voltage clamp technique was used. Papaverine (1-100 microM) inhibited the Ba++ inward current (IBa) through the voltage-dependent L-type Ca++ channel in a concentration-dependent fashion. The inhibitory effect of papaverine on IBa appeared to have both tonic and use-dependent components. In addition to the reduction of the maximal conductance of IBa, papaverine (20 microM) shifted the quasi-steady-state inactivation curve of IBa to more negative membrane potentials by approximately 10 mV. These effects of papaverine on IBa were completely reversible. Although it has been suggested that papaverine inhibited phosphodiesterase to increase intracellular cyclic AMP, phosphodiesterase inhibitors (theophylline, 500 microM, and 3-isobutyl-1-methylxanthine, 500 microM), isoproterenol (2 microM) and dibutyryl cyclic AMP (1 mM) did not affect IBa. Thus, papaverine inhibits IBa in a way independent of intracellular cyclic AMP. Papaverine also had inhibitory effects on other membrane currents (i.e., the voltage-dependent transient outward K+ current and the Ca(++)-activated oscillatory K+ current), which may result in an enhancement of the excitability of the cells. These results suggest that inhibition of the voltage-dependent L-type Ca++ channel is involved in the papaverine-induced relaxation of the tracheal smooth muscle.

Endothelin 1 hydrolysis by rat kidney membranes

Hydrolysis of endothelin 1 by rat kidney membranes was investigated using a reverse-phase HPLC and an automated gas-phase protein sequencer. Endothelin 1 was hydrolyzed into four major fragments which were detected by HPLC. Phosphoramidon, an inhibitor of neutral endopeptidase 24,11, almost completely suppressed the production of three fragments, but one fragment was not affected by the inhibitor. Analysis of N-terminal sequences of the degradation products revealed that the phosphoramidon-sensitive fragments were generated by cleavage at the Ser5-Leu6 bond of endothelin 1 that was identical with its cleavage site by purified rat endopeptidase 24,11, reported previously. The phosphoramidon-insensitive fragment was produced by cleavage at Leu17-Asp18, which was distinct from the sites by endopeptidase 24,11, but corresponded to that by a phosphoramidon-insensitive metallo-endopeptidase recently isolated from rat kidney membranes by us [(1992) Eur. J. Biochem. 204, 547-552]. Kinetic determination of endothelin 1 hydrolysis by the isolated enzyme yielded values of Km = 71.5 microM and kcat = 1.49 s-1, giving a ratio of kcat/Km = 2.08 x 10(4) s-1.M-1. The Km value was much higher and the kcat/Km value was much lower than those for rat endopeptidase 24,11 reported previously. Thus, endopeptidase 24,11 appears to hydrolyze endothelin 1 more efficiently than the isolated enzyme does. Both enzymes may play physiological roles in the metabolism of endothelin 1 by rat kidney membranes in vivo.

Salvage of infarcted myocardium by angiogenic action of basic fibroblast growth factor

Coronary collateral vessels reduce damage to ischemic myocardium after coronary obstruction. Factors that stimulate collateral formation are expected to have ameliorating effects on myocardial infarction. In a canine experimental myocardial infarct model, intracoronary injection of basic fibroblast growth factor (bFGF) improved cardiac systolic function and reduced infarct size. Treatment with bFGF increased the number of arterioles and capillaries in the infarct. Thus, the angiogenic action of bFGF might lead to a reduction in infarct size. The application of bFGF might bring about a therapeutic modality for the salvage of infarcted myocardium.

Alterations of calcium channels in vascular smooth muscle cells from spontaneously hypertensive rats

We examined the possible alterations in calcium handling through the calcium channels of spontaneously hypertensive rats (SHR) using 45Ca2+ uptake measurements in cultured aortic cells. Primary cultures of vascular smooth muscle cells (VSMC) were obtained by enzymatic dissociation of the thoracic aortas from 8-week-old SHR and age-matched Wistar-Kyoto rats (WKY). The functions of voltage sensitive calcium channels (VSCC) and receptor operated calcium channels (ROCC) were estimated from the activated 45Ca2+ uptake in VSMC with high K+ depolarization and arginine vasopressin (AVP), respectively. Compared to basal conditions, depolarization with 55 mM KCl increased 45Ca2+ uptake at 20 min by 94 +/- 17 (SE) % in SHR and 38 +/- 6% in WKY. The activated 45Ca2+ uptake was significantly greater in SHR than in WKY (p < 0.01). There was no significant difference in 45Ca2+ uptake at 20 min in the presence of 5 x 10(-8)M AVP between SHR and WKY. These results suggest that calcium uptake, at least through VSCC, is increased in VSMC of SHR. This enhanced activity may be implicated in the hypertensive mechanisms in this model of hypertension.

OPC-13340, a new dihydropyridine calcium channel blocker attenuates rapid vascular smooth muscle cell growth in spontaneously hypertensive rats

We investigated the mechanism of the antimitotic effects of calcium channel blockers in vascular smooth muscle cells (VSMC) from spontaneously hypertensive rats (SHR). VSMC from SHR exhibited rapid proliferation through a quick transition from the G0/G1 to the DNA synthetic (S) phase and from the S to the G2/mitotic (M) phase, whereas the DNA synthetic rate itself was equal to that of Wistar-Kyoto rats (WKY). OPC-13340, a new dihydropyridine calcium channel blocker, dose-dependently decreased incorporation of [3H]thymidine into the DNA fragments in randomly cycling VSMC in SHR. Cell cycle analysis showed that the rapid transition from the S to the G2/M period was restored by OPC-13340 to the control level in WKY, whereas the quick transition from G0/G1 to S was unaffected. This antimitotic effect of OPC-13340 was reflected by attenuation of enhanced cellular protein synthesis during the G2/M period. Protein synthesis in the G0/G1 period was not influenced by OPC-13340. Thus, these data indicate that the calcium channel blocker OPC-13340 mitigates the enhanced proliferation observed in randomly cycling VSMC from SHR and that this effect is primarily due to normalization of the premature mitosis during the G2/M period.

[Management of type A acute aortic dissection--results of the cases with thrombosed false lumen]

By reviewing the outcome, we studied the propriety of our principles for the treatment of type A acute aortic dissection in 45 patients, encountered during the 10-year period between 1981 and 1990. We conducted a comparative study of patients with a thrombosed false lumen (type T) and a patent false lumen (type P) to examine the effect of an acutely thrombosed false lumen on the prognosis of this disease. For the 25 patients treated in the first 6 years (1981-1986), operation was performed as soon as exact diagnosis was made, regardless of the presence of complications and the type or severity of the disease. Early death occurred in 9/20 operated cases and in 4/5 unoperated cases, so 13/25 patients died for a 52.0% mortality rate. For the 20 patients who received treatment in the latter period (1987-1990), we gave priority to conservative treatment for type T cases that were free from complications, and adopted a treatment method attaching greater importance to the resection of intimal tears. As a results, early deaths were observed in only 4 type P patients (20.0%) who underwent operation, a significant better result (p < 0.05). For patients in whom we were able to excise the intimal tear (30.0%, early mortality rate), the results were better than in those in whom the intimal tear were left alone (53.8%). The results were particularly good in type T patients (25.0% of them underwent intimal tear resection and 71.4% underwent no operation for the intimal tear).(ABSTRACT TRUNCATED AT 250 WORDS)

Mapping of the cochlear nucleus subregions in the rat with neuronal Fos protein induced by acoustic stimulation with low tones

To explore the mode of appearance of Fos, a gene product of proto-oncogene c-fos, in the cochlear nucleus, a pure tone was given to rats and Fos was detected by immunohistochemistry. Following low-tone stimuli applied with moderate ranges of sound intensity, neurons with Fos-label occurred band-like in the ventral subregions of the dorsal cochlear nucleus. Organization of low-to-high tones in the ventral-to-dorsal orientation became visible at the caudal level. Several other subnuclei consistently exhibited Fos with no topographic pattern. Neurons interspersed in the adjoining vestibulocochlear nerve were also found to elicit Fos. Low-tone stimuli with very high sound intensity led to a rather widespread distribution of Fos, making the tone-specific distribution less visible.

Plasma adenosine concentrations are elevated in conscious spontaneously hypertensive rats

1. Plasma levels of adenosine were measured in unrestrained, conscious spontaneously hypertensive rats (SHR) to examine the potential role of adenosine, a naturally occurring substance with profound cardiovascular actions, in cardiovascular regulation in these genetically hypertensive rats. 2. We employed a specific and sensitive assay for adenosine based on fluorescent determination of adenine compounds by high performance liquid chromatography. 3. Plasma adenosine concentrations were significantly higher in 13 week old SHR with hypertension than in Wistar-Kyoto rats (0.165 +/- 0.022 vs 0.096 +/- 0.008 mumol/L; P less than 0.05). 4. These observations indicate that plasma adenosine levels are increased in conscious SHR with established hypertension, and also suggest that adenosine may be at least partly involved in the pathophysiology of high blood pressure in SHR.

[Efficacy of nicorandil on myocardial protection during coronary artery bypass grafting--a comparison with diltiazem]

Diltiazem (DTZ), a calcium slow channel blocker, is estimated to be highly effective for myocardial protection and the prevention of perioperative coronary spasms (PCS). However, the use of high doses of DTZ sometimes results in difficulty in coming off cardiopulmonary bypass due to negative chronotropic activity. Nicorandil (NCD) has remarkable coronary vasodilating effect but possesses little negative chronotropic activity. The purpose of this study was to compare NCD with DTZ with respect to effect on myocardial protection during coronary artery bypass grafting (CABG). As parameters, excess lactate (delta XL), redox potential (delta Eh), left and right ventricular stroke work indices (LVSWI, RVSWI), cardiac index (C.I.), systemic vascular resistance index (SVRI.), myocardial isoenzymes (CK-MB, LDH1), number of PCS and recovery time of chronotropic action were used. delta XL, delta Eh, LVSWI, RVSWI, C.I., SVRI, CK-MB, LDH1 were measured at 0, 1, 3, 6, 9, 18 and 24 hours after the removal of aortic cross clamping. The degree of chronotropic action was evaluated by the length of the recovery time to self beat or normal sinus rhythm after the removal of aortic cross clamping. Forty patients who underwent CABG with retrograde cold blood cardioplegia between Dec. 1989 and May 1991 were divided into the NCD group (n = 20), in which 1.1 micrograms/kg/min NCD was continuously administered from the beginning of the operation and the DTZ group (n = 20), in which the initial St. Thomas cardioplegia containing 5 mg/L and subsequent cold blood cardioplegia solution contained DTZ 3.5 mg/L, for a total DTZ dose of less than 10 mg.(ABSTRACT TRUNCATED AT 250 WORDS)

New method of detecting nitric oxide production

Nitric oxide (NO) reacts with H2O2 to produce a rise in potent luminol-dependent chemiluminescence under neutral pH conditions. We applied this reaction to the continuous detection of NO released from the rat isolated perfused kidney with simultaneous pressure changes. Acetylcholine increased NO release dose-dependently with the pressure reduction. An NO synthesis inhibitor, NG-monomethyl-L-arginine, abolished the release. This inhibition was reversed by the addition of L-arginine.

[Clinical study of terodiline hydrochloride for the treatment of urinary frequency and urinary incontinence, and its cardiovascular adverse effects]

We evaluated the effectiveness and side effects of terodiline hydrochloride in 109 patients with urinary frequency and urinary incontinence. The drug was administered at a dose of 24 mg once a day or 12 mg twice a day for 4 weeks. Symptoms such as urinary frequency and urinary incontinence were alleviated in 101 out of 109 patients (92.7%). Mild side effects such as thirst, dysuria, sense of residual urine, orthostatic hypotension and arrhythmia were observed in 9 out of 109 patients (8.2%). Side effects such as orthostatic hypotension and arrhythmia were observed on the 28th day or the 20th day of the administration, but these symptoms disappeared with discontinued use of this medicine. The results obtained from this study suggest that terodiline hydrochloride may be greatly useful for the patients with urinary frequency and urinary incontinence. But we must take account of the side effects such as orthostatic hypotension and arrhythmia.

[Ischemic cardiomyopathy associated with ischemic mitral regurgitation--a case report of successful repair]

We experienced a case of 62-year-old man with ischemic cardiomyopathy and mitral regurgitation. He had a heart failure of New York Heart Association class IV together with unstable angina. His further examination showed an enlarged left ventricle with markedly reduced ejection fraction (12.9%) and ischemic mitral regurgitation of grade III associated with 3-vessel disease. He underwent three coronary artery bypass graftings and mitral annuloplasty by a modification of Kay's method. He showed a remarkable improvement of heart failure and cardiac function together with a disappearance of mitral regurgitation. He discharged from hospital in NYHA class II on the 50th postoperative day and lives an almost normal life now. Operative indication and management of ischemic cardiomyopathy and mitral regurgitation were discussed.

Distribution and cerebellar projections of cholinergic and corticotropin-releasing factor-containing neurons in the caudal vestibular nuclear complex and adjacent brainstem structures

By using immunohistochemistry combined with lesioning and retrograde neuronal labeling techniques, cholinergic neurons and corticotropin-releasing factor-immunoreactive neurons were examined for their distribution, coincidence and cerebellar projections in feline vestibular nuclear complex and adjacent brainstem structures. Cholinergic neurons as revealed here with choline acetyltransferase immunoreactivity were found massively in the abducens and hypoglossal nuclei, dorsal motor nucleus of the vagus nerve and nucleus of Roller; less numerously in the medial vestibular, prepositus hypoglossi and solitary nuclei and the caudal two-thirds of descending vestibular nucleus; and only occasionally in the intercalated and supravestibular nuclei and cell groups f, x and z. Corticotropin-releasing factor-immunoreactive neurons were found clustered in the prepositus hypoglossi nucleus and also in cell groups f and x and the rostral two-thirds of descending vestibular nucleus, less numerously in the medial vestibular, intercalated and solitary nuclei and nucleus of Roller, and only occasionally in the caudal one-third of descending vestibular nucleus, the dorsal motor nucleus of the vagus nerve, supravestibular nucleus and cell group z. The lateral and superior vestibular nuclei did not contain either type of neuron. The two types of immunopositive neurons observed in most of the brainstem nuclei differed in cell size, distribution-pattern and rostrocaudal level of occurrence. While there were many regions which exhibited both types of immunopositive neurons, perikarya colocalizing the cholinergic and peptide markers were not detected in the brainstem. Following unilateral, partial lesioning of the vestibular nuclear complex, corticotropin-releasing factor-immunoreactive mossy fiber terminals (rosettes) disappeared from the ipsilateral flocculus. However, such lesions did not produce clear-cut changes of cholinergic terminals in the vermis. Following retrograde neuronal labeling combined with immunohistochemistry, the two types of immunopositive neurons observed in most of the brainstem sites were found to project to the vermal lobules I-III, IX and X. On comparison of these immunopositive projection neurons with non-immunoreactive, retrogradely labeled neurons, the cholinergic neurons and the peptide-immunoreactive neurons were found to constitute a major part of the total vestibulocerebellar neuronal population. The results indicate chemical heterogeneity in vestibular nuclear complex and cerebellar afferents.

Sliding velocity of isolated rabbit cardiac myosin correlates with isozyme distribution

To investigate the relationship between the mechanical and biochemical properties of cardiac myosin, the sliding velocity of isolated cardiac myosin obtained from both euthyroid and hyperthyroid rabbits on actin cables was measured with an in vitro motility assay system. Ten rabbits (T) were treated with L-thyroxine to induce hyperthyroidism, and eight nontreated animals (N) were used as controls. Myosin was purified from the left ventricles of anesthetized animals. Myosin isozyme content was analyzed by the pyrophosphate gel electrophoresis method, and myosin adenosinetriphosphatase (ATPase) activity was determined on the same sample. Long well-organized actin cables of green algae, Nitellopsis, were used in the in vitro motility assay. Small latex beads were coated with purified cardiac myosin and introduced onto the Nitellopsis actin cables. Active unidirectional movement of the beads on the actin cables was observed under a photomicroscope, and the velocity was measured. The velocity was dependent on ATP concentrations, and the optimal pH for bead movement was approximately 7.0-7.5. The mean velocity was higher in T than in N (0.66 +/- 0.12 vs. 0.32 +/- 0.09 micron/s, P less than 0.01). Both Ca(2+)-activated ATPase activity and the percentage of alpha-myosin heavy chain were also higher in T than in N (0.691 +/- 0.072 vs. 0.335 +/- 0.072 microM Pi.mg-1.min-1, P less than 0.01, and 79 +/- 12 vs. 26 +/- 7%, P less than 0.01, respectively). The velocity of myosin closely correlated with both Ca(+2)-activated myosin ATPase activity (r = 0.87, P less than 0.01) and the percentage of alpha-myosin heavy chain (r = 0.87, P less than 0.01).

Inhibition of hepatic metastasis of colon carcinoma by asialo GM1--positive cells in the liver

This study investigates the role of hepatic asialo GM1-positive cells in inhibiting hepatic metastasis of colon carcinoma (colon adenocarcinoma 38) in mice after administration of a biological response modifier, streptococcal derivative (OK432). Administration of OK432 increased the number of asialo GM1-positive cells in the liver, enhanced natural killer activity of hepatic mononuclear cells and reduced the number of hepatic metastases of colon carcinoma inoculated into the superior mesenteric vein. Administration of antiserum against asialo GM1 reduced the number of hepatic asialo GM1-positive cells, abolished natural killer activity of hepatic mononuclear cells and increased the number of hepatic metastases. In addition, administration of antiserum against asialo GM1 even after OK432 treatment also decreased the number of asialo GM1-positive cells, reduced natural killer activity of hepatic mononuclear cells and increased the number of hepatic metastases of colon carcinoma. However, administration of gadolinium chloride, which suppresses phagocytic function of Kupffer cells, did not influence the natural killer activity of hepatic mononuclear cells or the number of hepatic metastases. In vivo tumor-neutralization assay revealed that tumor growth was inhibited by the hepatic mononuclear asialo GM1-positive cells, but not by T lymphocytes or Kupffer cells after OK432 administration. These results suggest that an increased number of hepatic asialo GM1-positive cells after administration of OK432 plays an important role in protecting against metastasis of colon carcinoma in the liver.