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Biomedical subjects

H Matsuda

Publications and source records attributed to H Matsuda.

At least 1,063 records · Page 59Linked to original sources
PubMed1993

Fate of right ventricular hypertrophy in tetralogy of Fallot after corrective surgery.

To elucidate the reversibility of right ventricular (RV) myocardial hypertrophy in tetralogy of Fallot (TF), 30 patients underwent RV endomyocardial biopsies 1 to 25 years (mean 9.7 +/- 6.6) after corrective surgery. Myocardial cell diameter was evaluated by comparing histopathologic data with preoperative patients with TF and normal subjects. As a whole, postoperative cell diameter was smaller than that of age-matched preoperative patients with TF, and larger than that of age-matched normal subjects. In 7 patients without significant residual pulmonary stenosis whose preoperative data were also available, cell diameter significantly decreased after surgery (17.1 +/- 2.1 to 14.0 +/- 2.1 microns, p < 0.01). There was a positive correlation between postoperative cell diameter and age at study (p < 0.01). To negate the influence of age, cell diameter was expressed in terms of a percentage of age-matched normal values (percent cell diameter). There was no significant correlation between percent cell diameter and age at surgery, age at study or the follow-up periods. There were positive correlations between percent cell diameter and the following parameters: RV systolic pressure (p < 0.05), percent normal RV end-diastolic (p < 0.05) and end-systolic (p < 0.01) volumes. These results demonstrate that RV myocardial hypertrophy in TF can regress to some extent after corrective surgery if significant residual pulmonary stenosis is avoided.

Adolescent↗
PubMed1993

Arenobufagin, a compound in toad venom, blocks Na(+)-K+ pump current in cardiac myocytes.

The effects of arenobufagin, a bufadienolide isolated from toad venom, on the Na+/K+ pump were investigated by recording the whole-cell current of dissociated cardiac myocytes. Arenobufagin blocked the Na+/K+ pump current in a dose-dependent manner with a half-maximal concentration of 0.29 microM and a Hill coefficient of 1.1. Arenobufagin is 3.5-fold more potent than ouabain.

Animals↗
PubMed1993

Enhancement of Doppler flow signals in the left heart chambers by intravenous injection of sonicated albumin.

OBJECTIVES: The objective of this study was to evaluate the effect of a transpulmonary contrast agent on Doppler flow signals in the left heart chambers. BACKGROUND: Echo contrast agents are good ultrasound reflectors and could be used as Doppler signal enhancers. Sonicated albumin microbubbles are transpulmonary echo contrast agents and could enhance left heart Doppler signals after peripheral venous injection. METHODS: Thirty-one patients with various heart diseases without intracardiac shunts were assessed with Doppler echocardiography before and after injection of sonicated albumin. RESULTS: After an intravenous injection, pulsed Doppler signals of transmitral flow became more intense in all 16 patients examined, although flow velocity itself was not changed. In Doppler color flow imaging, the maximal mitral regurgitant signal area increased from 312 +/- 405 mm2 to 434 +/- 465 mm2, an average increase of 59 +/- 40% in all 17 patients with mitral regurgitation (p < 0.01). These effects were considered to be due to improvement of signal to noise ratio by the enhancement of Doppler flow signals. The duration of enhancement of pulsed Doppler transmitral flow signals was significantly longer than that of the left ventricular echocardiographic opacification (44 +/- 11 s vs. 17 +/- 7 s, p < 0.01). CONCLUSIONS: Intravenous injection of sonicated albumin can enhance the Doppler flow signals in the left heart chambers. This effect may be useful to improve the sensitivity of the Doppler system for detecting abnormalities of left heart blood flow such as mitral regurgitation.

Atrial Function, Left↗
PubMed1993

Rapidity of progression of aortic stenosis in patients with congenital bicuspid aortic valves.

The rapidity of progression of aortic stenosis in patients with congenital bicuspid aortic valves, and its relation to aging and valve anatomy are not well known. To elucidate these aspects, 75 patients aged 15 to 76 years were examined by echocardiography. Aortic valve sclerosis began from the second decade, the sclerotic index progressing with age (r = 0.72; p < 0.0001). Aortic valve calcium was noted from the fourth decade. Aortic valve pressure gradient increased approximately 18 mm Hg each decade, concomitant with progression of valve sclerosis (r = 0.78; p < 0.0001). Progression of cusp sclerosis was faster in patients with anteroposteriorly located cusps than in those with right-left-located cusps (p < 0.005), and was faster in those with eccentric cusps (width ratio of major and minor cusps > or = 1.2) than in those with symmetric cusps (p < 0.05). In patients with eccentric and anteroposteriorly located cusps, aortic valve pressure gradient increased 27 mm Hg per decade. In patients with congenital bicuspid aortic valves, the progression of aortic stenosis is rapid, and the rapidity depends to some extent on the position and eccentricity of the cusps.

Adolescent↗
PubMed1993

Both CD45RA+ and CD45RA- subpopulations of CD8+ T cells contain cells with high levels of lymphocyte function-associated antigen-1 expression, a phenotype of primed T cells.

Expression of CD45 isoforms and some adhesion molecules on T cells change during T cell activation. In CD4+ T cells, it has been reported that CD45RA is lost and CD45RO is up-regulated when CD4+ T cells are stimulated. This change seemed to be irreversible and thus CD45RA may serve as a marker for virgin T cells and CD45R0 as a marker for memory T cells in CD4+ T cells. In CD8+ T cells, however, the expression of CD45 isoform has been less well understood. We have previously reported the switching of CD45 isoform expression may be reversible and CD8+CD45RA+ T cells may contain preactivated T cells. We present further evidence to support this notion by investigating the expression of lymphocyte function-associated Ag (LFA-1) in relation to CD45 isoform expression in various T cell populations in the human. In the thymus and umbilical cord blood, more than 97% of both CD4+ and CD8+ single positive T cells expressed LFA-1 at a low level. In CD4+ peripheral blood T cells, a high level of LFA-1 expression was found only in the CD45RA- population: 98% of CD45RA+ cells were LFA-1low. In CD8+ peripheral blood T cells, in contrast, a distinct population of LFA-1high cells was found in CD45RA+ subset, comprising about 45% of this subset in a 32-yr-old donor. In 7 days after stimulation with PHA, all CD4+ and CD8+ T cells, irrespective of their CD45 isoform expression, were LFA-1high. The proportion of CD45RA+ cells decreased in CD4+ but slightly increased in CD8+ T cells after the stimulation. These results support the notion that CD45RA and CD45R0 mark virgin and memory T cells respectively in the CD4+ T cells, and that CD8+CD45RA- T cells are primed. However, the validity of CD45RA as a marker of virgin cells in CD8+ T cells is seriously questioned.

Adult↗
PubMed1993

Age-related accumulation of LFA-1high cells in a CD8+CD45RAhigh T cell population.

The differential expression of CD45 isoforms has been suggested as a marker for stages of post-thymic T cell development, that is, CD45RA+CD45R0-T cells and CD45RA-CD45R0+ T cells are supposed to be virgin and memory cells respectively. Recently, several adhesion molecules have been shown to be up-regulated on the cell surface of memory T cells, and have been suggested to serve as a memory marker. In this study, we investigated the levels of LFA-1 expression on T cells in various subpopulations defined by CD45 isoform expression in donors of various ages. In CD4+ T cells, the proportion of LFA-1high cells among CD45RAhighCD45R0- T cells remained low in all age groups and did not show significant accumulation with age. CD4+CD45RA-CD45R0high T cells expressed LFA-1 at a higher level than CD4+CD45RAhighCD45R0- T cells. Thus, the currently prevailing view that CD45RA and CD45R0 can be markers for virgin and primed cells was consistent with LFA-1 expression in CD4+ T cell population. In CD8+ T cells, however, CD45RAhighCD45R0- T cells consisted of two distinct subpopulations, LFA-1low and LFA-1high cells, whereas CD45RA-CD45R0high T cells were almost exclusively LFA-1high. When CD29 expression was examined in place of LFA-1 expression, similar results were obtained; CD45RAhigh CD45R0- T cells consisted of two distinct subpopulations, CD29-to low and CD29high cells, while CD45RA-CD45R0high T cells were mostly CD29high. The proportion of LFA-1high cells in the CD8+CD45RAhigh T cell subpopulation increased significantly as a function of age (r = 0.9, p < 0.001). It ranged from 8% in a 14-year-old donor to 94% in a 79-year-old donor. Furthermore, the proportion of CD8+CD45RAhighLFA-1high cells in the CD8+ T cell population increased significantly as a function of age (r = 0.85, p < 0.001). On the other hand the proportion of LFA-1high cells in CD8+CD45RA- T cell subpopulation exceeded 90% in most donors irrespective of age. These results indicate that the CD8+CD45RAhighCD45R0- T cell subpopulation contains a considerable number of LFA-1high cells and CD29high cells, phenotypically similar to previously activated cells. Thus, in terms of LFA-1 and CD29 expressions, the simple scheme that CD45RA is a marker of virgin cells is not applicable to the CD8+ T cell population.

Adolescent↗
PubMed1993

Surgical treatment of esophageal carcinoma in patients eighty years of age and older.

Before 1979, no patient 80 years of age or older had been operated on at our institution for esophageal cancer, while in the middle period (1980-1984), three patients were operated on, and postoperative pulmonary complications and operative death occurred in 66.7 and 33.3%, respectively. However, in the recent period (1985-1990), there was no postoperative morbidity or mortality in the five cases over age 80. On the other hand, there were 12 patients over age 80 who did not undergo operation, of whom all died of cancer. In the eight operated patients over age 80, two cases are still alive 17 and 34 months after operation. According to the above findings, when the patient's general condition is evaluated to be sufficient to tolerate the operation and the cancer is judged to be resectable, esophageal resection is thought to be indicative in all patients over eighty.

Aged↗
PubMed1993

Pancreatic ductal cell carcinoma producing pancreatic elastase 1.

The elevation of plasma pancreatic elastase 1 in patients with pancreatic cancer is caused by concomitant pancreatitis. There is no report that pancreatic ductal cell carcinoma tissue itself produced elastase 1. A 54-year-old woman underwent total pancreatectomy for pancreatic ductal cell carcinoma. Her plasma elastase 1 level subsequently decreased from the preoperative value of 406 ng/dl to values ranging between 96 ng/dl and 119 ng/dl, until 6 months after the operation, when it began to increase gradually to a maximum of 300 ng/dl in association with local recurrence and hepatic metastasis. Immunohistochemical staining of elastase 1 was positive in the primary tumor resected at operation as well as in the locally recurrent and hepatic metastatic tumors obtained at autopsy. These findings suggested that elastase 1 was produced by the tumor cells in this patient. This is the first case in which pancreatic ductal cell carcinoma cells produced elastase 1.

Adenocarcinoma↗
PubMed1993

Differential expression of the proto-oncogenes c-abl and c-mos in developing mouse germ cells.

C-abl and c-mos, two proto-oncogenes with unique patterns of expression in gonadal tissues, were examined by in situ hybridization with respect to their expression in the germ line. C-abl transcripts were observed to be most abundant in late round spermatids and elongating spermatids. C-mos transcripts were also expressed in round spermatids, but at much reduced levels compared to the levels of c-abl. C-abl mRNAs were also detected in mouse oocytes which have entered the growth phase. This temporal specificity of accumulation of c-abl transcripts was similar to that observed for c-mos, which also accumulates in growing and fully grown oocytes (follicle stages 4-6). Quantitative evaluation suggested that c-abl mRNA levels in oocytes are at least an order of magnitude lower than those of c-mos transcripts.

Aging↗
PubMed1993

Noninvasive measurements of regional cerebral blood flow using technetium-99m hexamethylpropylene amine oxime.

The previously reported method for quantitative measurements of whole-brain or hemispheric-brain perfusion using technetium-99m hexamethylpropylene amine oxime (HMPAO) radionuclide angiography is now further developed so that regional cerebral blood flow (rCBF) can be measured. Lassen's correction algorithm is used for the linearization of a curve-linear relationship between the radioactivity in the brain and blood flow as seen with single-photon emission tomography (SPET) images. In this algorithm, the cerebral hemisphere was chosen as the reference region and the correction factor alpha was adapted to rCBF in the reference region. This new method of measuring CBF from SPET has been validated in 33 normal subjects and 22 patients with cerebrovascular disease. Regional CBF values in 20 brain regions of the normal subjects were in good agreement with reported values measured by other methods. Regional CBF in the frontal cortex was greater than that in the temporal, parietal or occipital cortex for the entire age range. This hyperfrontal perfusion tended to be less pronounced with advancing age. Seventeen patients with unilateral brain infarction showed significantly lower rCBF than normal subjects. The infarct core showed a low rCBF value of 11.1 ml/100 g/min on average. An increase in rCBF after acetazolamide administration was observed and measured with this method in five patients with unilateral occlusive vascular pathology. These results suggest that this non-invasive method (without any blood sampling) permits the routine measurement of rCBF from HMPAO SPET tomograms of blood flow.

Acetazolamide↗
PubMed1993

Gastric inhibitory polypeptide secretion after gastrectomy in patients with diabetes mellitus.

Gastric inhibitory polypeptide (GIP) secretion after distal gastrectomy was compared between patients with diabetes mellitus (DM-group) and patients with normal glucose tolerance (N-group). GIP secretion in the DM-group was significantly greater in the early postcibal response period, but less in the late postcibal response period after gastrectomy, the total secretion of GIP being less after gastrectomy than before in this group. In the N-group, both the early and total postcibal responses of GIP were greater after gastrectomy than before. Moreover, the early and total postcibal secretions of GIP after gastrectomy were less in the DM-group than in the N-group. These findings suggest that GIP secretion in diabetics becomes insufficient after gastrectomy.

Adult↗
PubMed1993

Radical resection of primary malignant melanoma of the gallbladder with multiple metastases: report of a case.

We present herein an usual case of primary malignant melanoma of the gallbladder in a 51-year-old man in whom an exploratory laparotomy for melena revealed six malignant melanoma lesions located in the gallbladder, main pancreatic duct, stomach, duodenum, jejunum, and a mesenteric lymph node. Total pancreatectomy was performed and histologically, junctional activity was seen only in the gallbladder, suggesting that this was the primary site. No melanotic lesions were found on the skin or eyes. The metastases to the main pancreatic duct and gastrointestinal tract appeared likely to have occurred as a consequence of the mucosal dissemination of the tumor cells shed into the bile. The post-operative course was uneventful and combined chemotherapy was administered for 16 months. No new metastatic lesions were found until 21 months postoperatively, when metastases were detected in the brain and thoracic spinal cord. These metastatic tumors were removed surgically, but the patient died from cerebral disturbance 26 months after the initial operation. Thus, we consider that aggressive surgical therapy was effective for extending the survival time and improving the quality of life of this patient.

Adult↗
PubMed1993

Fast and slow blockades of the inward-rectifier K+ channel by external divalent cations in guinea-pig cardiac myocytes.

The present patch-clamp study shows that external Mg2+, Ca2+ and Sr2+ decrease the unit amplitude of inward current through the inward-rectifier K+ channel in a concentration-dependent manner. Sr2+ produces a voltage-dependent flickering block as well, and the fractional electrical distance between the external orifice and the Sr2+ binding site (delta) is 0.73. The decrease of unit amplitude is reversible and voltage independent while it does not increase the noise level on the open-channel current. Unit current decreased by Mg2+ or Ca2+ has a longer mean open time, which is inversely proportional to the unit amplitude. External Mg2+ does not decrease the amplitude of unit outward current. A surface potential shift, measured using voltage-dependent Cs+ block (delta = 1.60), failed to explain the current decrease. Therefore, we conclude that (1) the external divalent cations cause an extremely fast channel block, which appears as a decreased amplitude of the unit current on the recording system; (2) the blocking site (fast site) is present near the external orifice of the channel, and it is separate from the blocking site (slow site) to which Cs+ and Sr2+ bind.

Animals↗
PubMed1993

High detection rates of cryptococcal antigen in pulmonary cryptococcosis by Eiken latex agglutination test with pronase pretreatment.

Two different kits for the detection of serum cryptococcal antigen in patients with pulmonary cryptococcosis were evaluated. The Eiken test (the Eiken Co., Tokyo), which uses pronase for pretreatment of serum, was compared with the Crypto-LA test (International Biological Laboratories, Cranbury, NJ), which did not use pronase prior to testing. Cryptococcal antigen was detected in 21 of 23 patients (91%) with the Eiken test and in only 10 of 23 patients (43%) with the Crypto-LA test (p < 0.01 by McNemar test). However, the sensitivity of two tests was identical without use of pronase, as both tests could detect as little as 10(4) cells/ml of Cryptococcus neoformans and 10 ng/ml of capsular polysaccharide of C. neoformans. In those serum specimens for which both tests were positive, titers were much higher for the Eiken test, but there was a statistically significant correlation between the two tests (coefficient correlation 0.79, p < 0.01). Cryptococcal antigen titer levels measured by the Eiken test correlated well with clinical courses. There was one false-positive reaction among 82 sera of non-cryptococcal patients. Pronase enhanced the sensitivity of the Eiken test, which appeared to be useful in patients with pulmonary cryptococcal disease, and its use may prevent unneeded lung biopsies.

Adult↗
PubMed1993

Eradication of metastatic tumour cells from lymph nodes by local administration of anti-CD3 antibody.

The possibility of in vivo removal of metastatic tumour cells from lymph nodes by local intradermal administration of an anti-CD3 monoclonal antibody (mAb) was examined. Murine tumour cells in the lymph nodes were completely eradicated by intradermal injections of the mAb. This treatment was effective for removal of Lewis lung cancer cells from lymph nodes, but not for removal of subcutaneous tumours of this cell line. This treatment induced in vivo cytotoxicity in the regional lymph nodes against the syngeneic tumour cells. The following in vitro studies suggested that the cytotoxicity was probably mediated mainly by CD4+ T cells, with slight participation of CD8+ T cells. Normal lymph node and spleen cells showed cytotoxicity after in vitro incubation with the mAb for 2 days. Cell sorting with a fluorescein-activated cell sorter showed that CD4+ T cells developed during the incubation to lyse syngeneic tumor cells directly by themselves, macrophages not being involved in this tumour cell lysis. The lytic activity was detected in the cellular fractions, but not in the culture supernatants of these T cells. Furthermore, it was completely blocked by specific antiserum for tumour necrosis factor-alpha (TNF alpha). An immunoprecipitation study revealed that these T cells expressed TNF alpha molecules of 26 kDa, but not of 17 kDa, suggesting that tumour cell lysis was caused by membrane-integrated integrated TNF alpha molecules. These results strongly suggest that local administration of anti-CD3 antibody is a very effective and appropriate procedure for eradication of metastatic tumour cells from regional lymph nodes.

Animals↗
PubMed1993

Involvement of cyclo-oxygenase-generated vasodilating eicosanoid(s) in addition to nitric oxide in endothelin-1-induced endothelium-dependent vasorelaxation in guinea pig aorta.

This study investigates the vasodilatory effects of endothelin-1 (ET-1) in isolated guinea pig aortic rings in vitro. Cumulative dose-response curves to ET-1 were constructed and ET-1 actions on prostaglandin F2 alpha (PGF2 alpha)-precontraction were studied in both endothelium-intact and endothelium-denuded preparations, in the presence or absence of a cyclooxygenase inhibitor (indomethacin) and/or nitric oxide inhibitors (NG-nitro-L-arginine methyl ester and hemoglobin). In endothelium-intact preparations, pretreatment with indomethacin (10(-5) M, 30 min), alone or in combination with NG-nitro-L-arginine methyl ester (L-NAME, 10(-4) M), significantly augmented the constrictive responses to ET-1, whereas indomethacin, L-NAME, and hemoglobin (10(-5) M) had no significant effects in the endothelium-denuded preparations. Furthermore, in PGF2 alpha-precontracted, endothelium-intact preparations, ET-1, at a dose of 10(-9) M, induced initial relaxation followed by subsequent contraction, while it only contracted the endothelium-denuded preparations. The initial relaxation was abolished by indomethacin, but not by L-NAME or hemoglobin. In addition, this relaxation was not inhibited by a specific ETA receptor antagonist, BQ-123 (6 x 10(-6) M). In addition to the involvement of nitric oxide, these results show the involvement of cyclo-oxygenase-generated vasodilating eicosanoid(s) derived from endothelium in ET-1-induced vasorelaxation in guinea pig aorta in vitro. The results also indicate that this vasorelaxation is mediated by ETB receptor activation.

Animals↗