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Biomedical subjects

M Arita

Publications and source records attributed to M Arita.

At least 325 records · Page 18Linked to original sources

Septal myocardial abscess and infectious pericarditis in a case of bacterial endocarditis.

A case of acute aortic valve endocarditis is reported, in which the complications of pericarditis and myocardial abscess were diagnosed clinically. Two dimensional and M-mode echocardiography showed large echo-free spaces and a marked thickening of the interventricular septum which had not been detected previously, suggesting pericardial effusion and myocardial abscess. This is the first case in Japan to our knowledge, in which the pericarditis and myocardial abscess were detected preoperatively and successfully treated surgically.

Abscess↗

Central actions of circulating angiotensin II on the sympathetic nervous system and blood pressure control.

The effects of intravertebral artery infusions of [Sar1, Ile8] and [Sar1, Thr8] angiotensin II on the central nervous system were studied in furosemide-treated dogs anesthetized with alpha-chloralose. Acute administration of furosemide led to a significant increase in plasma renin activity, plasma noradrenaline levels and heart rate, and also to a slight rise of blood pressure. In the furosemide-treated dogs, intravertebral artery infusion of either angiotensin II antagonist (250 ng/Kg/min, for 30 min) suppressed the furosemide-induced increases in plasma noradrenaline, heart rate and arterial blood pressure. The effects of [Sar1, Thr8] angiotensin II on the last two parameters were more pronounced than those of [Sar1, Ile8] angiotensin II. Intravenous infusion of the same dose of each antagonist had little influence on the furosemide-induced increases in arterial blood pressure, heart rate and plasma noradrenaline levels. These results suggest that the central actions of angiotensin II contribute to the regulation of blood pressure through the sympathetic nervous system.

1-Sarcosine-8-Isoleucine Angiotensin II↗

[The role of hypertension in apical hypertrophy].

Recent advances in echocardiography have revealed that hypertension causes several types of cardiac hypertrophy. We classified hypertensive patients by type of cardiac hypertrophy, and evaluated left ventricular function and the severity of hypertension. The subjects consisted of 257 hypertensive patients, 13 patients with cardiac hypertrophy, and 95 normotensive controls. The hypertensives were classified in four groups: no hypertrophy, concentric hypertrophy, asymmetrical septal hypertrophy (ASH), and asymmetrical apical hypertrophy (AAH). The normotensive patients with cardiac hypertrophy included nine with ASH and four with AAH. Cardiac functions in these patients were determined by echocardiography, RI-angiocardiography and cardiac catheterization. The results were as follows: Among 257 hypertensive patients, the incidence of concentric hypertrophy, ASH, and AAH was 53%, 10%, and 4%, respectively. In patients with AAH and hypertension, the hypertensive blood pressure levels and hypertensive organ involvements were mild. The blood pressures of most of these patients fell to the normal range after admission. The cardiac index and left ventricular systolic function (FS, mVCF, and ejection fraction) were significantly higher in AAH with hypertension than in the other hypertensive groups or in the normotensive controls. The hypertensive patients showed lower E-F slopes and higher A/E ratios than the normotensive controls, as well as the normotensive patients with ASH or AAH. Cardiac function did not differ appreciably between normotensive AAH and hypertensive AAH. Left ventricular dimension and left ventricular end-diastolic volume index were larger in AAH with hypertension. The total peripheral resistance of the hypertensive AAH was significantly lower than that of the hypertensives with concentric hypertrophy (p less than 0.01), though it was higher than that of the normotensive AAH (p less than 0.01). It was, therefore, concluded that mild hypertension observed in patients with AAH may be the result of regulatory mechanisms in the hyperkinetic states.

Adolescent↗

Adjuvant immunotherapy of primary resected lung cancer with transfer factor.

One hundred seventy-one patients were studied in order to evaluate the clinical efficacy of the transfer factor (TF) for primary resected lung cancers under a randomized controlled trial. Eligible cases for evaluation were randomly chosen at 75 and 74 patients in TF and control groups, respectively. The same long-term intermittent adjuvant chemotherapy was administered to two groups as a standard therapy. The distribution of clinical features in both groups was very similar. The overall survival rates of the TF group at 2 and 4 years postoperatively were 69% and 53%, respectively, which was about 15% better than the control group, but this difference could not yet be considered statistically significant. The survival of the TF group was significantly better than that of the control group in patients with Stages I + II or curative resection (P less than 0.05 by Cox-Mantel test); however, there was no significant difference in patients with Stages III + IV, or noncurative resection. The recurrence rate of pulmonary and mediastinal regions was less in the TF group. In conclusion, TF seems to suppress postoperative recurrence and appears to be beneficial for primary resected lung cancer patients, especially at early stages, as postoperative adjuvant immunotherapy.

Adult↗

Studies on bioactive gangliosides: II. Requirement of ganglioside GD1a for prolonged GQ1b-driven nerve growth promotion in neuroblastoma cell lines.

The novel effects of gangliosides from human brain on the number of nuclei of nerve cells and neurite outgrowth were studied in cultures of human neuroblastoma cell lines GOTO and NB-1. Ganglioside GQ1b at a nanomolar level stimulated cell proliferation and neurite outgrowth during culture for 24 hours, as reported previously [J Biochem 94: 303-306, 1983]. Although the neurite promoting activity of GQ1b was similar to those of total human brain gangliosides (GS) and nerve growth factor (NGF), its activity on cell proliferation did not persist on longer culture; that is, the number of GQ1b-treated cells rapidly decreased to the control level during culture for 48 or 72 hours. In contrast, on treatment with GS or NGF, the number of cell nuclei increased continuously during prolonged culture. These results showed that either some other molecular species of ganglioside(s) than GQ1b or other substances such as proteins present in the GS fraction were responsible for the long-term activity. Studies on the GS fraction after its treatment with proteases and neuraminidases revealed that ganglioside GD1a (20 ng/ml) had the ability to prolong the activity of GQ1b. Namely, GQ1b and GD1a gangliosides cooperated in maintaining the number of nuclei in long-term cultures of neuroblastoma cell lines.

Cell Differentiation↗

Randomized controlled trial of transfer factor immunochemotherapy as an adjunct to surgical treatment for primary adenocarcinoma of the lung.

A total of 102 patients were studied in a randomized controlled trail to evaluate the clinical effect of transfer factor (TF) for primary resected adenocarcinoma of the lung. The TF and Control groups consisted of 50 and 52 randomly chosen patients, respectively. However, 6 and 5 patients were excluded from both groups for various reasons, therefore the total of cases eligible for evaluation were 44 and 47 in the TF and Control groups, respectively. The clinical features of both groups were similar. The survival of the TF group was significantly better than that of Controls in Stage I cases (p less than 0.05), however, there was no significant difference in patients in Stages II, III and IV. Significant differences were found between the TF and Control groups in curative resection cases (p less than 0.05), however, no significant difference was seen in either the relatively curative resection or noncurative resection groups. TF seems to inhibit postoperative recurrence and appears to be an effective postoperative adjuvant immunotherapeutic for primary resected adenocarcinoma of the lung, especially at the relatively early stages.

Adenocarcinoma↗

Isotachophoretic evidence for energy-preservating effect of coenzyme Q10 on isolated guinea-pig cardiac muscle.

Effects of coenzyme Q10 (CoQ10) on hypoxia-induced changes in ATP, NAD and NADH levels were studied in the isolated atrial and ventricular muscles of guinea-pigs. Guinea-pigs were pretreated with CoQ10 (60 mg/kg/day, i.p.) or the solvent for 3 consecutive days before initiation of study. The concentrations of ATP, NAD and NADH were determined by isotachophoresis. The concentrations of ATP and NAD contained in the atrial or ventricular muscle decreased with increasing incubation time with hypoxic Tyrode's solution (pO2 not equal to 160 mmHG), but that of NADH increased. However, the ATP and NAD concentrations of atrial and ventricular muscles from CoQ10-pretreated animals tended to be higher than those from solvent-pretreated ones. Moreover, the increase in NADH concentration during hypoxia tended to be less in the CoQ10-pretreated preparation than in the solvent-pretreated one. These results suggest that the pretreatment with CoQ10 leads to the increase in CoQ10 content in mitochondria of heart muscle, thereby permitting the improvement of oxidative phosphorylation in the mitochondria during hypoxia.

Adenosine Triphosphate↗

Positive and negative ion fast atom bombardment mass spectrometry of glycosphingolipids. Discrimination of the positional isomers of gangliosides with sialic acids.

High molecular weight gangliosides (GD1a, GD1b, GT1a, and GT1b) and neutral glycosphingolipids (Forssman antigen, globoside, and CTH) containing various fatty acids were analyzed by positive and negative ion fast atom bombardment mass spectrometry (POS-FAB-MS and NEG-FAB-MS) without any derivatization. NEG-FAB-MS of the molecules gave intense peaks of the molecular ion species, (M-H)-, and many fragment ions useful for the elucidation of carbohydrate structure were also detected with significant intensity. The fragment ions were assessed to be cleaved at the glycosidic linkages sequentially from the non-reducing end with or without the ceramide portion and it was possible to distinguish structural isomers having different binding positions of sialic acid. All molecular ion species of neutral glycosphingolipids with various fatty acids were detected at intensities that were in accordance with the relative abundance of the fatty acids.

Animals↗

Characterization of new hydrophobic pili of human enterotoxigenic Escherichia coli: a possible new colonization factor.

Enterotoxigenic Escherichia coli strains were divided into five groups on the basis of their bacterial surface hydrophobicity (Honda et al., FEMS Microbiol. Lett. 17:273-276, 1983). Strains in group III showed heat-stable high hydrophobicity, although they did not show mannose-resistant hemagglutination with either human or bovine erythrocytes. E. coli strain 260-1 in group III was characterized. Electron microscopic examination revealed the presence of pili on the surface of this strain, but not on that of strain 260-1a, which is a mutant of 260-1 showing low hydrophobicity. When strain 260-1 was grown at 18 degrees C, it did not produce pili or show high hydrophobicity. On homogenization of strain 260-1 grown at 37 degrees C the high hydrophobicity and the pili on its surface were lost. These results indicate that the pili of strain 260-1 are associated with the hydrophobicity. Strain 260-1 pili were purified to homogeneity by successive column chromatographies on Sepharose 4B and phenyl-Sepharose CL-4B. Their molecular weight was estimated to be about 18,000. An antigenic difference between purified pili of strain 260-1 and colonization factor antigens I and II was demonstrated. The colonization ability of E. coli 260-1 was shown by animal experiments on suckling mice and infant rabbits. From these results it is concluded that the pili of strains in group III of human enterotoxigenic E. coli, which may play a role in colonization, are of a new type.

Animals↗

Carcinosarcoma of the ureter.

A rare case of carcinosarcoma of the ureter is reported. Histologically, this neoplasia was an unusual heterologous carcinosarcoma of the ureter. 2 years after the initial total nephroureterectomy, the patient died from recurrence.

Aged↗

Lysophosphatidylcholine decreases single channel conductance of inward rectifier K channel in mammalian ventricular myocytes.

Effect of lysophosphatidylcholine (LPC) on the inward rectifier K channel of the isolated guinea pig ventricular cell was studied using patch clamp technique. In that LPC (100 microM) decreased the magnitude of the single channel conductance from 48 +/- 5 pS (mean and S.D., n = 5) to 12 +/- 9 pS (n = 8), this event may be the prime factor related to the alleged LPC-induced depolarization of cardiac tissues.

Animals↗