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Biomedical subjects

T Masuda

Publications and source records attributed to T Masuda.

At least 523 records · Page 29Linked to original sources
PubMed1989

[Echocardiographic study of a cardiac murmur in cor triatriatum: a case report].

This is a report of an aged patient with cor triatriatum in whom the mechanism of his cardiac murmur was elucidated by Doppler and contrast echocardiography. This 63-year-old man was followed up for cardiomegaly detected at 40 years of age, and he had been treated for a cardiac murmur due to valvular disease during the previous 10 years. He was admitted to our hospital for the evaluation of incidental hematemesis. A phonocardiogram recorded over the apex showed a regurgitant murmur from early to mid-systole, followed by a continuous murmur lasting up to mid-diastole. Two-dimensional echocardiogram revealed an abnormal septum in the left atrium dividing the atrium into two chambers and showing bulging in late systole through diastole. In the lower chamber, color Doppler echocardiography disclosed continuous turbulent flow originating from the bulge directing the mitral orifice. Contrast medum coursing toward the mitral orifice was demonstrated during contrast echocardiography and left ventriculography, which coincided with the turbulent signal on the Doppler echocardiogram. The description of the cardiac murmur of cor triatriatum suggests that it is not persistent. Conceivably, it is a continuous murmur, whose mechanism can be elucidated by Doppler and contrast echocardiography.

Contrast Media↗
PubMed1989

[Effect of recombinant human erythropoietin administration on cardiovascular system in patient with chronic renal failure: an analysis of the blood pressure upward].

To investigate the mechanism of blood pressure upward after recombinant human erythropoietin (EPO) administration in patient with chronic renal failure (CRF), hemodynamic changes following on the improvement of anemia was evaluated by the echocardiography. Fourteen (5 males, 9 females) normotensive patients with less than 23% of hematocrit (HT) were administered 1,500 approximately 3,000 units of EPO three times a week. Four patients with systolic (greater than 160 mmHg) or diastolic (greater than 90 mmHg) hypertension after EPO administration was named group H, the remaining patients was named group N. Blood pressure, heart rates and parameters of echocardiography examined after the improvement of anemia were compared to those examined before EPO administration, respectively. Patients had an increase in Ht from 20.0 +/- 1.6% to 33.0 +/- 1.9% (p less than 0.01). LVDd, LVEDV, CO and flow velocity in group N were significantly decreased after EPO administration; while those in group H did not show the significant changes. IVSth and LVPWth in each group were significantly increased after EPO administration. These data showes that decrease in CO maintains the patients normotensive after EPO administration.

Adult↗
PubMed1989

[Changes in catecholamines of the striatum during 5% oxygen administration and the alleviating effects of flunarizine in rats].

Five percent oxygen was administered to rats under controlled respiration. The concentrations of catecholamines and their metabolites (dopamine, HVA, DOPAC, norepinephrine) were measured during 5% oxygen administration and subsequent recovery period. Flunarizine, a calcium channel blocker, was administered and its effects on catecholamine fluctuations were studied. Results were as follows. Dopamine increased with 5% oxygen administration. DOPAC and norepinephrine decreased and no changes were seen in HVA. After 20 min of hypoxia, catecholamine contents returned to the control levels in another 2 hours of air breathing. When flunarizine was administered in advance, changes in catecholamine content appeared to be lower during 5% oxygen administration and subsequent recovery period.

Animals↗
PubMed1988

Anti-idiotypic antibodies against UV-induced tumor-specific CTL clones. Preparation in syngeneic combination.

In this study, we first established several CTL clones of (BALB/c x C57BL/6)F1 origin that were specific for either syngeneic UV female 1 or UV male 1 fibrosarcoma cell lines. All the CTL clones had Thy-1+ Lyt-2+ L3T4- phenotypes and showed Kd restriction when lysing the corresponding target cells. Sera obtained from syngeneic animals immunized with three CTL clones, 10B-5 for UV female 1, and CTL9 and CTL10 for UV male 1, showed specific inhibition of target cell lysis with the corresponding CTL clones. The inhibitory activities were found in sera of the majority of immunized animals. Because the inhibitory activity resides in protein A-binding fraction, mAb were produced by hybridizing spleen cells of hyperimmune animals. N1-56 was thus obtained from a mouse immunized with 10B-5 CTL clone reactive with UV female 1. N1-56 was clonotype specific, reacting with 10B-5 but not with other CTL lines or leukemia cell lines. No N1-56+ cells were detectable in thymocytes, lymph node cells, or spleen cells of either naive or UV female 1-immune CB6F1 mice. Immunoprecipitation showed that N1-56 reacts with 90,000 Mr molecules on 10B-5 CTL clone under nonreducing conditions and 45,000 Mr molecules under reducing conditions, indicating its reactivities with idiotypic determinants of TCR on the CTL clone. N1-56 inhibited lytic activity of 10B-5, but neither N1-56 nor alpha-10B-5 hyperimmune serum inhibited that of alpha-UV female 1 mixed lymphocyte tumor cell culture cells. N1-56 induced proliferation of 10B-5 without addition of Ag.

Animals↗
PubMed1988

Fulminant clonal expansion of large granular lymphocytes. Characterization of their morphology, phenotype, genotype, and function.

A 39-year-old woman exhibited abrupt malignant transformation of the large granular lymphocytes (LGL) after a chronic course of T gamma-lymphoproliferative disease (T gamma-LPD). The T gamma-lymphocytes were CD2+, CD3-, CD8-, CD16+, Leu7-, and Leu19+ with morphologic characteristics of LGL. Newly appearing LGL were much larger and had more prominent azurophilic granules. Although fundamentally they had the same phenotype as the LGL in chronic stage, they showed increased Ia-like antigen and decreased CD16 antigen expressions. Immunoglobulin (Ig) G-kappa type monoclonal component was detected in the patient's serum. The LGL showed a germ-line configuration for T-cell receptor (TCR) beta and gamma chain genes, whereas the clonal chromosomal abnormalities indicated the neoplastic nature of the LGL. The LGL exhibited competent natural killer (NK), interleukin 2 (IL2) activated killer (AK), and antibody-dependent cell-mediated cytotoxicity (ADCC) activities. The LGL may have derived from NK cells at their mature stage with prethymic phenotype and may have influenced the homeostasis of the patient's humoral immune response.

Adult↗
PubMed1988

[Distribution of neurotensin-like immunoreactivity (NTLI) and neurotensin receptor in the rat brain and effects of various drugs on NTLI concentration and NT receptor in the rat cerebral cortex].

A radioimmunoassay for neurotensin(NT) and binding assay for NT receptor have been developed to determine neurotensin-like immunoreactivity (NTLI) concentration and to characterize NT receptor in the rat brain. The effect of various drugs affecting the dopaminergic system in the brain were also investigated to clarify the relationship between NT and dopamine. NTLI was widely distributed in various regions of the rat brain: the highest level was 53.1 +/- 14.1 ng/g wet wt in the hypothalamus, 11.9 +/- 6.0 ng/g wet wt in the thalamus, 6.9 +/- 0.7 ng/g wet wt in the cerebral cortex and 0.7 +/- 0.2 ng/g wet wt in the cerebellar cortex. The Bmax of NT receptor was 20.2 +/- 4.6 fmol/mg protein in the cerebral cortex, 16.0 +/- 4.9 fmol/mg protein in the hypothalamus, 13.3 +/- 3.7 fmol/mg protein in the thalamus and no detectable level in the cerebellar cortex. The Kd of NT receptor was 2.7 +/- 0.7 nM in the cerebral cortex, 1.9 +/- 0.8 nM in the hypothalamus, 1.1 +/- 0.2 nM in the thalamus. Intraperitoneal(ip) bolus administration of L-DOPA caused the reduction in NTLI concentration from 9.2 +/- 1.0 ng/g wet wt to 5.3 +/- 2.1 ng/g wet wt and Bmax of NT receptor from 19.7 +/- 3.1 fmol/mg protein to 13.9 +/- 2.6 fmol/mg protein with no change in Kd. Intracerebroventricular administration of dopamine also induced a significant reduction of NTLI concentration and Bmax of NT receptor with no change in Kd. Inversely, ip bolus administration of alpha-methyldopa evoked an increase in NTLI concentration from 6.9 +/- 0.9 ng/g wet wt to 12.0 +/- 3.0 ng/g wet wt and that in Bmax of NT receptor from 15.9 +/- 2.9 fmol/mg protein to 24.2 +/- 4.6 fmol/mg protein. Serial administration of haloperidol evoked an increase in Bmax of NT receptor from 16.9 +/- 1.5 fmol/mg protein to 20.5 +/- 1.9 fmol/mg protein with no changes in Kd and NTLI concentration. These results suggest that dopamine may modulate the action of NT in the rat cerebral cortex.

Animals↗
PubMed1988

The existence of low concentrations of atrial natriuretic peptide (ANP) in canine cerebrospinal fluid which does not correlate with plasma ANP levels.

Atrial natriuretic peptide (ANP) concentrations in the cerebrospinal fluid (CSF) and plasma of canine were 2.1 +/- 1.1 pg/ml (mean +/- S.D.) and 53.1 +/- 21.1 (n = 20), respectively. The regression coefficient between these concentrations was -0.0045 (P = n.s.). The ANP concentration in the CSF did not change even after the plasma ANP concentration was altered following the change of left atrial pressure, as in 4 cases of an experimental aortic regurgitation. Thus, ANP concentration in the CSF is not influenced by ANP concentrations in the plasma at least under our condition. Gel permeation chromatography revealed a single form of ANP in the position of authentic alpha-ANP in canine CSF, while a high molecular weight ANP peak was observed as well as alpha-ANP in the plasma.

Animals↗
PubMed1988

Isolation of simian immunodeficiency virus from African green monkeys and seroepidemiologic survey of the virus in various non-human primates.

Sixteen isolates of simian retrovirus closely related to human immunodeficiency virus (HIV) were obtained from healthy African green monkeys (AGM) (Cercopithecus aethiops). The first isolate was obtained from a monkey seropositive for HIV, and the others were isolated from monkeys harboring antibodies to the first isolate. These simian retroviruses were referred to as simian immunodeficiency virus from AGM, SIV[AGM], due to their cross-reactivities with HIV structural proteins. These SIV[AGM] isolates were found by Western blotting analysis to have virus-specific proteins of 120, 66, 55, 32-40, 24 and 17 kDa, which were all similar in size to the analogous proteins of HIV. Putative gag proteins of p55, p24 and p17 were recognized by sera of human AIDS patients, but the corresponding env proteins of 32-40 and 120 kDa showed only weak cross-reactivity with those of HIV. The transmembrane glycoproteins of these 3 SIV[AGM] isolates showed size heterogeneity, being 32, 35 and 40 kDa. This virus had particles that were morphologically similar to those of HIV, and had Mg2+-dependent reverse transcriptase. Furthermore, the SIV[AGM] showed tropism and cytopathic effects on CD4-positive human cell lines. In a sero-epidemiological survey of SIV[AGM] in various non-human primates, 2 other African monkey species, the mandrill and de Brazza's monkey, were also found to have antibodies to SIV[AGM]. These HIV-related simian retroviruses will be important in determining the origin and transmission of HIV group viruses, and may provide useful animal models for studies on the infection and pathogenesis of HIV and AIDS.

Animals↗
PubMed1988

Glycolipid-directed FH6 monoclonal antibody recognizes high molecular weight glycoprotein antigen carrying sialyl Lex-i determinant in the culture supernatant of PC-9 cells.

The properties of the antigen recognized by monoclonal antibody FH6 have been analyzed. FH6 was originally generated against a glycolipid, i.e. a difucoganglioside isolated from human colonic adenocarcinoma, and specifically reacts with sialyl Lex-i determinant. Several culture supernatants of human carcinoma cell line cells were found to have high levels of FH6-reactive antigen, and PC-9, a human lung carcinoma cell line was used for the analysis. A solid-phase sandwich radioimmunoassay was performed to detect the antigen. The antigenic activity was extractable in 0.6 M PCA or 7% TCA, and was sensitive to mild alkaline treatment and to Pronase digestion. Most of the antigen was eluted in the void volume of a Sepharose CL-2B column, which indicates that its molecular weight is greater than several million. It was eluted from a DEAE-cellulose column at a NaCl concentration in the range of 0.2-0.25 M. The immunoaffinity-purified antigen has a high carbohydrate content of more than 80%. These data indicate that the antigen recognized by FH6 in the culture supernatant of PC-9 is not a glycolipid, but a high molecular weight glycoprotein which could be referred to as a mucin, or a proteoglycan, which contains keratan-sulfate like glycosaminoglycan chains, as judged from the results of the glycosidase treatments.

Antibodies, Monoclonal↗
PubMed1988

Phagocytic activity of Kupffer cells in splenectomized rats.

Carbonized polyethylene microspheres of 3.53 micron diameter were injected intravenously into splenectomized, laparotomized, and untreated rats. The number of Kupffer cells which phagocytosed microspheres and the number of microspheres phagocytosed by single Kupffer cells were counted. The number of Kupffer cells which phagocytosed microspheres was 1.51 times greater in splenectomized rats than in untreated rats, and 1.29 times greater in splenectomized rats than in laparotomized rats, both values being statistically significant. Although this same value was 1.18 times greater in laparotomized rats than in untreated rats, this was not statistically significant. The number of microspheres phagocytosed by single Kupffer cells also increased significantly in splenectomized rats. The intra-acinar distribution of the phagocytosing Kupffer cells showed the number in the periportal area to be 8-9 times greater than in the central area in all 3 groups. No significant difference in this intra-acinar distribution was observed between the groups. In addition, there was no difference in the phagocytic activity of Kupffer cells and the distribution of phagocytosing Kupffer cells between the hepatic lobes.

Animals↗
PubMed1988

Fibre conduction velocity and fibre composition in human vastus lateralis.

The relationship between muscle fibre composition and fibre conduction velocity was investigated in 19 male track athletes, 12 sprinters and 7 distance runners, aged 20-24 years, using needle biopsy samples from vastus lateralis. Cross sectional areas of the fast twitch (FT) and slow twitch (ST) fibres were determined by histochemical analysis. The percentage of FT fibre areas ranged from 22.6 to 93.6%. Sprinters had a higher percentage of FT fibres than distance runners. Muscle fibre conduction velocity was measured with a surface electrode array placed along the muscle fibres, and calculated from the time delay between 2 myoelectric signals recorded during a maximal voluntary contraction. The conduction velocity ranged from 4.13 to 5.20 m.s-1. A linear correlation between conduction velocity and the relative area of FT fibres was statistically significant (r = 0.84, p less than 0.01). This correlation indicates that muscle fibre composition can be estimated from muscle fibre conduction velocity measured noninvasively with surface electrodes.

Adult↗
PubMed1988

Correlation between serum immunosuppressive substance and clinico-pathological findings in patients with gastric carcinoma.

Serum levels of immunosuppressive substance (IS) were determined in 99 patients with gastric cancer and in 32 healthy individuals. The serum IS levels in the patients (769.6 +/- 314.8 micrograms/ml) were significantly higher than those in the healthy individuals (549.7 +/- 104.7 micrograms/ml). A multivariate analysis on the correlation between serum IS levels and clinicopathological findings in the patients disclosed that there was a close correlation between the serum IS levels and the depth of invasion, in particular, the prognostic serosal invasion, metastasis to the distal lymph nodes and peritoneal dissemination. There was, however, no correlation between the serum IS level and hepatic metastasis. Serum IS levels were higher in patients with well-differentiated adenocarcinoma than in those with poorly differentiated adenocarcinoma or signet ring cell carcinoma. A serum IS level higher than 1000 micrograms/ml indicates the possibility that the tumor is only palliatively resectable because of involvement of the distal lymph nodes or peritoneal dissemination.

Adenocarcinoma↗
PubMed1988

Biochemical analysis of inhibitory effects of a lymphokine suppressive B-cell factor on the activation process of resting B cells.

Suppressive B-cell factor (SBF) is elaborated by FcR gamma (Fc receptor for IgG)-bearing small, resting B cells after the stimulation of immune complexes and is known to inhibit humoral immune responses by acting on resting B cells. In order to elucidate where and how SBF interferes with B-cell activation in the course of transmembrane signaling, we examined the effect of SBF on the several sequential events which B cells undergo after crosslinking surface immunoglobulin (sIg). Hyper-Ia expression, plasma membrane depolarization, and activation of phosphatidylinositol (PI) hydrolysis of resting B cells, all of which were induced by the stimulation with anti-mu antibody, were significantly suppressed by the pretreatment of cells with SBF. However, SBF had no effect on the intracytoplasmic cyclic AMP level of either activated or resting B cells. Another inhibitory effect of SBF on the activation process of resting B cells by anti-mu antibody was to suppress the transient elevation of intracytoplasmic free Ca2+ only in the initial phase after triggering with anti-mu antibody. This seems to be due to a decrease in the release of inositol triphosphate into the cytoplasm by suppressing the activation of PI hydrolysis. Considering all the data, the suppressive effect of SBF on the transmembrane signaling by sIg crosslinking is ascribed to the selective suppression of the activation of PI hydrolysis. This provides a concept on a molecular basis that feedback regulation of humoral immune response is, at least partly, regulated by SBF.

Animals↗