Search PubMed⌕ Search

Biomedical subjects

T Shiota

Publications and source records attributed to T Shiota.

At least 181 records · Page 10Linked to original sources
PubMed1988

Chemical and structural studies of serotype polysaccharide antigens of Streptococcus sobrinus 6715.

The g antigen of Streptococcus sobrinus 6715 was previously shown to consist of polysaccharides of various molecular weights. In this study, two such polysaccharides, LII and LIII, were purified by gel filtration and affinity chromatography procedures. By a double immunodiffusion analysis, fraction LII was found to contain a region in the serotype-specific g site not present in the serospecific g site of fraction LIII. This region was designated x. In addition to the serotype-specific g site, the cross-reactive sites, g-a, g-d, and g-(a-d), were all present on a single molecule of fractions LII and LIII. Polysaccharides LII and LIII were composed of galactose, glucose, and rhamnose. Analysis of inhibition of the precipitin reaction suggested that the serotype g site of fraction LII (the putative form of g antigen) may consist of two immunodominant regions, one a galactose-containing region (region x) and the other a glucose-containing region, while the serotype g site of fraction LIII appeared to have one immunodominant region containing a glucose determinant. The methylation and 13C nuclear magnetic resonance analyses of LII and LIII fractions provided information on the linkage and the anomeric structures of the sugar components of the polysaccharides.

Antigens, Bacterial↗
PubMed1988

Assessment of the thickness of the right ventricular free wall by magnetic resonance imaging in patients with hypertrophic cardiomyopathy.

Electrocardiogram gated magnetic resonance imaging was performed in nine healthy volunteers, in four patients with pulmonary hypertension, and in 16 patients with hypertrophic cardiomyopathy. Fifty two short axis images in diastole were examined to assess the usefulness of magnetic resonance imaging for the measurement of the thickness of the free wall of the right ventricle and the degree of hypertrophy of the right ventricular free wall in hypertrophic cardiomyopathy and pulmonary hypertension. Magnetic resonance imaging gave a clear image of 68% of the length of the right ventricular free wall, showing both the endocardial and epicardial margins. The mean (1 SD) thickness of the right ventricular free wall measured at a total of 512 points was 0.44 (0.12) cm in patients with hypertrophic cardiomyopathy, 0.29 (0.08) cm in healthy individuals, and 0.73 (0.27) cm in patients with pulmonary hypertension.

Cardiomyopathy, Hypertrophic↗
PubMed1988

[Distribution patterns of hypertrophy at the apical level in patients with giant negative T waves: identification by magnetic resonance imaging].

To clarify the distribution patterns of hypertrophy at the apical level in patients with giant negative T waves (GNT), ECG-gated magnetic resonance imaging (MRI) was performed in 10 patients with GNT and in five normal controls. End-diastolic left ventricular short-axis images at the basal and apical levels were obtained in all subjects. Thicknesses of the septal, anterior, lateral and posterior walls at these two levels were measured and distribution of hypertrophied myocardium (more than or equal to 15 mm) at the apical level was examined. The ratio (R) of the maximal thickness at the apical level over that at the basal level was calculated. In normal subjects, the mean apical wall thickness was 8.7 +/- 1.9 mm. In the GNT group, the wall thickness was always greater than the mean value +3 SD of the normal control, and there were no differences among the four segmental walls. The hypertrophic portions at the apex were circumferential in three, septal-anterior-lateral in two, septal-anterior in two, septal in one, anterior in one and lateral in one. In patients with GNT, the average maximal thickness at the apical level was 19.3 +/- 3.2 mm; by location, four cases in the septum, four in the anterior wall and two in the lateral wall, and the average minimum thickness was 11.7 +/- 3.7 mm; all in the posterior wall. The R was more than 1.3 in nine patients with GNT and less than 1.0 in all normal subjects. In conclusion, there was a variety of patterns of apical hypertrophy, and the R greater than or equal to 1.3 was characteristic in patients with GNT.

Adult↗
PubMed1988

[Mitral valve prolapse in patients with post-operative atrial septal defect: a preliminary report].

To investigate the clinical significance of mitral valve prolapse (MVP) in patients with atrial septal defect, we investigated 90 patients using various techniques including phonocardiography, mechanocardiography and echocardiography. The examinations were repeated pre- and post-operative periods, and the particular attention was paid on the behavior of the mitral valve motion after surgery. Post-operatively, the incidence of MVP was 56% (50 of 90 patients) compared with the preoperative incidence of 78%. Improvement of MVP was only 24%, and there was no case in which MVP newly developed after surgery. Clinical and laboratory data indicated that the cases with MVP after surgery had larger Qp/Qs, higher pulmonary pressures and larger right ventricular dimension pre-operatively, but had no relationship to the age of surgery and the deformity index of the left ventricle. MVP after surgery was not associated with significant mitral regurgitation.

Adolescent↗
PubMed1987

Light microscopical study of Blastocystis spp. in monkeys and fowls.

An investigation of a Blastocystis species obtained from several species of monkeys and fowls was conducted to clarify the morphology of the organism, using light microscopical techniques including Giemsa, Heidenhain iron hematoxylin, Trichrome stains, iodine mount and phase-contrast microscopy. A comparison was made with Blastocystis hominis from humans. Blastocystis spp. were found in 15 out of 26 monkeys and in all of 12 fowls (10 chickens and 2 ostriches) examined. The behaviour of the parasites in the bowels was also examined, using paraffin-embedded sections. Microscope examination of the lumen contents at death revealed the organism in the caecum of monkeys and fowls. The organisms from faeces, cultures and the lumen contents of the caecum of humans, monkeys and fowls were similar, except for variations in the size and contents of the central vacuoles, which occupied the centre of the organisms.

Animals↗
PubMed1987

[Left ventricular short-axis plane for magnetic resonance imaging: its clinical importance and applications].

Left ventricular short-axis images were obtained by ECG-gated magnetic resonance imaging (MRI) in nine patients with hypertrophic cardiomyopathy and seven patients with chest pain, all of whom had diagnostic cardiac catheterization including angiography. The accuracy and usefulness of the short-axis image in MRI for measuring wall thickness and dimension and for calculating ejection fraction were evaluated. All patients were examined on an examination couch in the right anterior oblique position in optimal positions to obtain the left ventricular long-axis images in the Z-X plane (conventional coronal plane). Next, the paraxial mode was used to obtain the short-axis images by rotating the Y-Z plane (conventional sagittal plane) around the Y axis. The intervals between the trigger on the middle point of the upstroke of the R wave and the 90 degree pulse of saturation recovery spin echo sequence were 40 msec and 340 msec with a 34 msec echo delay time for the end-diastolic and end-systolic images, respectively. Short-axis images in MRI in end-diastole were utilized to measure wall thickness and dimension in patients with hypertrophic cardiomyopathy and the measurements obtained were compared with those of echocardiography. As for calculating ejection fraction in patients with chest pain, the length of the left ventricular long axis (L) was measured using the MRI long-axis image. The intraventricular sectional area at four levels (S1, S2, S3, S4) were measured using the MRI short-axis image in end-diastole and in end-systole. Left ventricular end-diastolic and end-systolic volumes were calculated using the following formula: V = 1/2 X (L -4.5) X S1 + 1.5 X (S1 + S2 + S3) + 1/3 X 1/2 X (L -4.5) X S4. Ejection fraction by MRI was compared with that by cardiac catheterization (single plane, area-length method). The measurements of wall thickness and dimension by MRI correlated well with those by echocardiography (r = 0.97, p less than 0.01). Ejection fraction calculated by MRI correlated significantly with that by cardiac catheterization (r = 0.82, p less than 0.05). We concluded that the left ventricular short-axis image in MRI is satisfactorily accurate for measuring wall thickness and dimension, and useful for evaluating the left ventricular ejection fraction.

Angina Pectoris↗
PubMed1987

[Aortic regurgitation in hypertrophic cardiomyopathy as detected by color Doppler echocardiography].

Aortic regurgitation (AR) in patients with hypertrophic cardiomyopathy (HCM) has rarely been reported. Using color Doppler echocardiography, we assessed the incidence and the cause of AR in patients with HCM. There were 86 patients with HCM (M:F = 66: 20, 57 +/- 12 years, mean +/- SD) and 43 control subjects (M: F = 33: 10, 57 +/- 8 years). HCM was diagnosed by echocardiography; the thickness of the interventricular septum (IVS) was more than 15 mm and the ratio to the thickness of the left ventricular free wall (LVPW) was more than 1.3. The rate and degree of aortic regurgitation were observed by color Doppler echocardiography, and aortic regurgitant murmurs were recorded by phonocardiography. Echocardiographic measurements were made using standard techniques. In the M-mode echocardiograms, the aortic diameter, the thicknesses of the IVS and LVPW were measured. In the 2DE, calcification of the aortic valve and systolic anterior movement of the mitral valve (SAM) were evaluated. In the early systolic 2DE image, the distance from the point of the greatest bulging of the upper IVS to the aortic root (D1) and the distance from the point of the greatest bulging to the line which is parallel to the long axis of the aorta (D2) were measured. Results were as follows: 1. Color Doppler echocardiography revealed aortic regurgitation in 17 (21%) patients with HCM; whereas it was observed in only three (7%) of the control subjects. 2. The aortic regurgitant signals were limited to the left ventricular outflow tract both in patients with HCM and in the control subjects. 3. Aortic regurgitant murmurs were recorded in only two patients with HCM and in none of the control subjects. 4. There was no difference between the patients with and without AR as to age (59 vs 56 years), blood pressure (141/84 vs 136/80 mmHg), aortic diameter (34 vs 33 mm), aortic valve calcification (12% vs 9%) and SAM (53% vs 52%). 5. In the patients with HCM, D1 was shorter (9.9 vs 14 mm, p less than 0.001) and D2 was longer (16 vs 10 mm, p less than 0.001) in the patients with AR than in those without AR. That is, the basal septum of the patients with AR protruded more deeply into the outflow tract, and the distance to the aortic valve was significantly shorter than in those without AR.(ABSTRACT TRUNCATED AT 400 WORDS)

Aged↗
PubMed1986

Ammonia detoxification by accelerated oxidation of branched chain amino acids in brains of acute hepatic failure rats.

BCAA aminotransferase and BCKA dehydrogenase activities are increased in the mitochondrial fractions from the brains of hepatic failure rats treated with two-thirds removal of CCl4-injured liver. Cerebral leucine decarboxylation was accelerated, and it well correlated with arterial blood ammonia levels. Elevation of brain ammonia content following an intraperitoneal injection of ammonium acetate to hepatic failure rats could be prevented by intravenous infusion of BCAA. Significantly increased brain glutamic acid, glutamine, and alanine contents were noted. These results suggested that accelerated brain BCAA catabolism in acute hepatic failure rats reduce the neurotoxicity of ammonia by promoting the synthesis of glutamic acid and glutamine from BCAA.

Acute Disease↗
PubMed1986

Morphology, development and behavior of Pneumocystis carinii observed by light-microscopy in nude mice.

The present paper describes the morphology, development and behavior of Pneumocystis carinii, especially of the trophozoites in the alveoli of conventionally raised BALB/c nude mice, by using phase-contrast microscopy, paraffin sections and semiultrathin sections embedded in JB-4 plastic. Under phase-contrast microscopy, trophozoites were ameboid in external appearance and 2 to 8 micron in diameter. Usually they have one or more lucid spherical vacuoles and one less lucid nucleus in the cytoplasm. Maturation and independence of intracystic bodies were observed in the developing cysts. The intracystic bodies were polymorphic, i.e. spherical, ameboid or elongated. The paraffin sections using the double staining of P. carinii with Gomori's methenamine silver nitrate (GMS) and Giemsa, showed a small number of mature cysts containing intracystic bodies and a large number of trophozoites within the characteristic honeycombed material in the alveolar spaces. In order to investigate the morphology and parasitizing behavior of the trophozoites and cysts as well as the response of alveolar tissue in more detail, semiultrathin sections of 0.5-2 micron thickness were made from the materials embedded in JB-4 plastic and stained with Giemsa. In lightly infected alveoli, some trophozoites and cysts were found to be closely attached to the Type I alveolar epithelial cells. In heavily infected alveoli, almost all alveoli were filled with trophozoites, cysts, debris of the host cells, and occasionally phagocytic cells (macrophages and neutrophils) containing cysts or trophozoites were found. It was noted that the cysts were very few in number (1%) compared with the number of the trophozoites in nude mice in a 0.4 mm2 area of 2 micron thick lung sections. The host tissue of nude mice in this study was not as strongly affected by the organisms as that in cortisone-treated rats and P. carinii pneumonia patients. In the present study the morphology of P. carinii found in nude mice was not different from that found in rats and in man.

Animals↗
PubMed1986

Prevalence of Pneumocystis carinii in wild rodents in Japan.

During the period from November 1980 to April 1984, 292 small wild rodents were captured in 6 localities in Japan. Eleven out of 142 Apodemus speciosus, 1 out of 11 A. argenteus, 4 out of 40 Microtus montebelli and 2 out of 3 Mus musculus were positive for Pneumocystis carinii. The intensity of infection was generally low and the infection rate did not show any significant difference between sexes of the host animals. The seasonal prevalence of infection in A. speciosus was not remarkable, but was somewhat higher in winter to spring than in summer to autumn. Also, the infection rate in A. speciosus was higher in relatively heavy body weights than in the lighter or the heaviest weight groups. This is the first report of P. carinii infection in wild rodents in Japan. We propose A. speciosus, A. argenteus and M. montebelli as the new natural hosts for P. carinii. No morphological difference was found between P. carinii in wild rodents, in rats and in man as far as the present light microscopic examination is concerned.

Animals↗
PubMed1986

Plasma level of branched chain alpha-amino acids following its alpha-keto acid administration to rats.

To detect the effective substance accelerating the conversion of branched chain alpha-keto acids (BCKA) to corresponding amino acids, some sugars, sugar alcohols, ethanol, octanoate and ATP were tested with intravenous injection of three BCKA to rats. Plasma leucine levels 30 min after BCKA injection in rats, which were infused with 2 M solution of fructose or sorbitol, reached the significantly high peak corresponding to 860% and 790% of the basal levels. Administration of ethanol (2 or 3.5 M) or octanoate (4.5 mM) also resulted in significantly high levels of leucine in plasma following BCKA injection as compared with control. Molar ratio of plasma branched chain amino acid (BCAA)/aromatic amino acid 30 min after BCKA injection increased to 12.9 in control rats. The ratios 60 and 120 min after BCKA administration were significantly higher in rats treated with ethanol (3.5 M) or octanoate (4.5 mM) than those in control. These results suggest that infusion of the metabolites inducing high NADH/NAD ratio in their metabolic pathways results in inhibition of BCKA decarboxylation and, as a result, enhancement of transamination of BCKA into BCAA.

Adenosine Triphosphate↗
PubMed1986

[Clinical significance of the measurement of serum neuron-specific enolase levels in patients with lung cancer].

Subjects were comprised of 100 healthy adults, 85 patients with primary lung cancer, 20 with benign lung disease and 4 with metastatic lung cancer. Serum neuron-specific enolase (NSE) levels were estimated by means of an NSE RIA kit produced by Eiken Radiopharmaceutical Co., Ltd. The normal range of serum NSE level was between 4.5 and 10.30 (mean: 6.81) ng/ml in the 100 healthy adults. The serum NSE level in patients with small cell carcinoma was significantly higher than the mean in patients with other histological types. Positive rates of serum NSE levels were 80% in patients with small cell carcinoma, 54% in patients with adenocarcinoma, 52% in patients with squamous cell carcinoma and 1% in healthy adults, respectively. According to the progress of staging in lung cancer patients, serum NSE levels became increased. Serum NSE level seems to be specific marker in patients with small cell lung cancer and to be useful for diagnosis and the monitoring of cancer treatment.

Adenocarcinoma↗
PubMed1986

Blood to brain transfer of carbon tetrachloride and lipoperoxidation in rat brain.

[14C]-Carbon tetrachloride (CCl4) entered extensively into the liver and, to the small extent, into the brain 3 hr following the intragastric administration of the hepatotoxic dose. Although thiobarbituric acid (TBA) in the liver homogenates increased 12 hr after CCl4 administration, the brain showed little TBA values probably due to very low levels of chytochromes P-450 and b5 in the brain. These results suggest that CCl4 have no direct toxic effect upon the brain.

Animals↗
PubMed1985

Impaired acetaldehyde metabolism in partially hepatectomized rats.

Two-thirds hepatectomy in rats resulted in elevated blood ethanol and acetaldehyde levels as compared to those of sham operated and CCl4-induced toxic injured rats. The acetaldehyde/ethanol ratio increased also. Although the liver mass regenerated within 3 days, ethanol metabolism remained disturbed. Mitochondrial aldehyde dehydrogenase activity was significantly diminished only following partial hepatectomy. The results suggest that abnormal ethanol and especially acetaldehyde metabolism in partially hepatectomized rats is not due simply to reduced liver tissue but to a diminished aldehyde dehydrogenase activity in the remaining tissue.

Acetaldehyde↗