Biomedical subjects

A Matsuo

Publications and source records attributed to A Matsuo.

At least 55 records · Page 3Linked to original sources

PubMed1999

Improved survival of idiopathic dilated cardiomyopathy in the 1990s.

To analyze the recent change in the long-term survival of patients with dilated cardiomyopathy (DCM), the present study comprised consecutive 111 patients with ejection fraction <50% and left ventricular end-diastolic diameter >58 mm. who were admitted to hospital from January 1983 to December 1994. The patients were divided into 2 groups: group A who were diagnosed before 1989 and group B diagnosed after 1990. Basic characteristics at diagnosis, including age, NYHA functional class, left ventricular end-diastolic diameter and ejection fraction, were similar between these 2 groups. Calculated survival rate at 5 years was 90.0% in group B in contrast to 62.3% in group A. Event-free survival also improved in group B. In group B, beta-blockers and angiotensin converting enzyme inhibitors were more frequently used than in group A (p<0.0001) whereas digitalis and other positive inotropic agents were significantly less used. Left ventricular ejection fraction was significantly improved during the follow-up period in patients treated with beta-blockers compared with those not treated with beta-blockers. These data indicate a significant improvement in the survival of patients with dilated cardiomyopathy after 1990, which may be explained by the change of medical treatment, especially the use of beta-blockers.

Adrenergic beta-Antagonists↗

PubMed1999

Serum carnitine concentrations in patients with idiopathic hypertrophic cardiomyopathy: relationship with impaired myocardial fatty acid metabolism.

We evaluated the clinical significance of serum carnitine concentrations in determining the severity of impaired myocardial fatty acid metabolism in idiopathic hypertrophic cardiomyopathy (HCM). We studied 56 asymptomatic or mildly symptomatic patients with HCM. Serum levels of free carnitine and acylcarnitine were measured by the enzymic cycling method. Myocardial scintigraphy with (123)I-labelled 15-(p-iodophenyl)-3-R,S-methylpentadecanoic acid (BMIPP) was performed, and the images were analysed quantitatively and semi-quantitatively. Serum free carnitine levels were significantly higher in HCM patients than in normal subjects (52. 5+/-9.5 and 42.3+/-5.5 nmol/ml respectively; P<0.0001). On the other hand, serum acylcarnitine levels and acyl/free carnitine ratios were lower in HCM patients than in normal subjects (10.2+/-4.0 nmol/ml and 0.19+/-0.08, compared with 13.2+/-3.9 nmol/ml and 0.32+/-0.11 respectively; P<0.0001). Clinical characteristics were not significantly different between the patients showing high and normal free carnitine levels, although female patients with high free carnitine levels were few (P=0.02). Both quantitative and semi-quantitative analyses revealed that the severity of decreased myocardial BMIPP uptake was significantly correlated with serum free carnitine levels (quantitative analysis: r=-0.422, P<0.0012; semi-quantitative analysis: r=0.633, P<0.0001). In the presence of reduced carnitine uptake into the myocardium in HCM, there may also be reduced transport of acylcarnitines out of the myocardium into the plasma. Although inborn errors of fatty acid metabolism and carnitine deficiencies are reported to provoke secondary HCM and are associated with low serum carnitine concentrations, this study has revealed that the levels of carnitine are, in contrast, increased in idiopathic HCM. Moreover, serum carnitine concentrations are a sensitive indicator of the severity of impaired myocardial fatty acid metabolism even in asymptomatic patients with HCM.

Adolescent↗

PubMed1998

Fibroblast growth factor receptor-1 expression in the cortex and hippocampus in Alzheimer's disease.

Localization of fibroblast growth receptor (FGFR)-1 immunoreactivity was investigated immunochemically in postmortem brain tissue of Alzheimer's disease (AD) and age-matched control cases using a rabbit polyclonal antibody and a mouse monoclonal antibody specific for FGFR-1. In control cases, FGFR-1 immunoreactivity was identified in astrocytes in white matter and in hippocampal pyramidal neurons. In AD cases, the immunoreactivity in reactive astrocytes surrounding senile plaques was increased. The pattern of FGFR-1 immunoreactivity was confirmed in selected cases by in situ hybridization for FGFR-1 mRNA. Immunoreactivity using a monoclonal antibody demonstrated a similar distribution pattern. The localization of FGFR-1 is consistent with previous reports on the involvement of FGF-1 and FGF-2 in AD.

Aged↗

PubMed1998

Immunohistochemical analyses of fibroblast growth factor receptor-1 in the human substantia nigra. Comparison between normal and Parkinson's disease cases.

The use of neurotrophic growth factors as a means of preventing loss of the dopaminergic (DA) neurons in the substantia nigra (SN) is becoming an accepted treatment strategy for Parkinson's disease (PD). In earlier studies, we showed that there was a selective loss of basic fibroblast growth factor (bFGF) immunoreactivity in DA neurons of the SN in PD suggesting that a deficiency of bFGF might contribute to cell death. As a preliminary step to assessing the potential for using bFGF or its analogs as therapeutic agents, the expression of fibroblast growth factor receptor-1 (FGFR-1) in the SN of normal and PD cases was investigated immunohistochemically. FGFR-1 immunoreactivity could be detected in DA neurons of the SN in young and old neurologically normal cases with an apparent decline with age. FGFR-1 immunoreactivity was also detected in many of the residual SN neurons in most of the idiopathic PD cases. These results indicate that FGFR-1 immunoreactivity, and possibly FGF binding activity, is retained in DA neurons in PD.

Adult↗

PubMed1998

Myelin degeneration in multiple system atrophy detected by unique antibodies.

A rabbit antiserum (anti-EP), induced against a synthetic peptide corresponding to residues 68 to 86 of guinea pig myelin basic protein, powerfully immunostained abnormal-appearing oligodendrocytic processes and cell bodies in demyelinating areas associated with multiple system atrophy (MSA). However, as we reported previously, the antiserum, which is highly specific for the sequence QDENPVV corresponding to human myelin basic protein residues 82 to 88, failed to recognize any structures in normal human brain. QD-9, a mouse monoclonal antibody raised against human myelin basic protein residues 69 to 88, which also recognizes specifically the epitope QDENPVV, gave the same results as did anti-EP. The unusual epitope recognized by anti-EP/QD-9 antibodies appears to be accessible in areas of myelin degeneration, and the antibodies have been shown to detect such areas in multiple sclerosis and infarcted brains. These antibodies detect myelin degeneration more widely than previous conventional methods. The present study emphasizes the importance of myelin degeneration in the pathogenesis of multiple system atrophy.

Aged↗

PubMed1998

Therapeutic and diagnostic potential of a vasopressin-2 antagonist for impaired water handling in cirrhosis.

OBJECTIVE: Progressive cirrhosis is associated with increasing difficulty to handle free water. We examined the therapeutic potential of an orally active nonpeptide vasopressin-2 receptor antagonist (OPC-31260) in the management of edema and ascites in patients with cirrhosis. By means of its chemical blockade of the vasopressin-2 receptor in the kidney, we also assessed the ability of renal water handling in the early stage of cirrhosis. METHODS: A single 30 mg dose of OPC-31260 was administered orally to eight biopsy-proven patients with cirrhosis who had ascites or peripheral edema. The aquaretic responses were compared with those in six healthy subjects. RESULTS: In the patients with cirrhosis, OPC-31260 significantly (p < 0.01) increased the urinary excretion rate at 0 to 2 hours, and significantly (p < 0.01) lowered urine osmolality at 2 to 4 hours after administration. Free water clearance increased from -0.48 +/- 0.14 to +0.19 +/- 0.21 ml/min (p < 0.05) at 0 to 4 hours after administration. However, these aquaretic responses in the patients with cirrhosis were only approximately half the responses observed in the healthy subjects. A significant (p < 0.05) inverse relationship was observed between indocyanine green retention at 15 minutes after administration and the maximal free water clearance after administration to the patients with cirrhosis. Urinary sodium excretion did not change significantly in the patients, whereas it increased twofold in the healthy subjects. Urinary vasopressin excretion tended to increase in the patients, whereas it increased twofold to threefold (p < 0.01 to 0.05) from the baseline in the healthy subjects. Urinary prostaglandin E2 excretion was not increased, and serum sodium and plasma vasopressin levels were elevated only slightly in both groups. CONCLUSIONS: Even though a hyporesponsiveness was observed in the group of patients with cirrhosis compared with the healthy group, the novel vasopressin-2 antagonist induced hypotonic diuresis in patients with cirrhosis, suggesting a therapeutic potential in managing water excess. This drug response may be a new index to assess impairment of water handling in patients with cirrhosis.

Administration, Oral↗

PubMed1998

The effects of training on left ventricular systolic and diastolic function in female college rowers.

We studied the effects of vigorous rowing training on left ventricular structure and function using M-mode, two-dimensional and Doppler echocardiography in 10 female college rowers. Echocardiographic measurements were performed before and after 20 weeks of rowing training. Diastolic function was also estimated by measuring the isovolumetric relaxation time (IRT), deceleration time (DcT), peak velocity of early diastolic rapid filling flow (Ep), peak velocity of atrial filling flow (Ap) and the Ep/Ap ratio on left ventricular inflow Doppler wave form. The relative contribution of atrial systole to stroke volume was also calculated as the area under the flow velocity profile during atrial systole using the total area of the flow velocity profile. After training there was a significant increase in the left ventricular diastolic dimension (LVDd), posterior wall thickness, left atrial dimension, left ventriculer mass (LVM), LVM index and stroke volume (SV). No significant change in IRT, or DcT was detected after training. Although there was an increase in mean values of Ep, no statistical significance was observed. Training also induced a significant decrease in Ap and the percent of SV contributed by atrial systole, while the ratio of Ep/Ap increased (p < 0.01). These results indicate that rowing training increases the LVDd and LVM index without impairment of left ventricular diastolic function in college female rowers.

Adolescent↗

PubMed1998

Possibility of independence in ADL (Activities of Daily Living) for patients with cervical spinal cord injuries--an evaluation based on the Zancolli Classification of Residual Arm Functions.

For patients with cervical spinal cord injuries to become independent in their ADL (Activities of Daily Living), residual arm function is very important. Also, age, sex, physical strengths, obesity, spasticity, pain, contracture and motivation are related. We investigated the possibility of independence in ADL for patients with cervical spinal cord injuries, carrying out our evaluation based on the Zancolli Classification of Residual Arm Functions. Zancolli classification C6BII is taken as the boundary level for ADL independence. Rehabilitation is not only controlled by the patients with cervical spinal cord injuries themselves but also by the ability of the rehabilitation staff. This implies that taking responsibility in rehabilitation important.

Activities of Daily Living↗

PubMed1997

Encephalitogenic peptide (EP) in human cerebrovascular white matter lesions.

The expression of encephalitogenic peptide (EP), a 68-86 amino acid sequence of guinea pig myelin basic protein (MBP), was investigated in autopsied brains with focal cerebral damage or with diffuse white matter (WM) lesions. EP immunoreactive fibers were distributed in parallel with fibers immunoreactive for amyloid protein precursor (APP), an indicator of WM damages. EP was expressed in the periphery of cerebral infarctions and hematoma in the acute and subacute stages, but was also distributed in diffuse WM lesions due to heterogeneous causes. These data indicate that EP epitopes are exposed specifically in ongoing WM damages, and that the destruction of myelin occurs sporadically in diffuse WM lesions of varying intensity.

Aged↗

PubMed1997

Inhibitory mechanisms of beta-adrenoceptor agonists for immunoglobulin E-mediated experimental allergic reactions in rats.

Inhibitory mechanisms of isoproterenol and clenbuterol for immunoglobulin E (IgE)-mediated experimental allergic reactions in rats were studied. IgE-mediated passive cutaneous anaphylaxis, histamine-induced cutaneous reaction and serotonin-induced cutaneous reaction were evoked at the same time in the same rats. Isoproterenol administered intravenously immediately before challenge inhibited all these reactions significantly. Clenbuterol administered intravenously 0-3 h before challenge also significantly inhibited the three cutaneous reactions. The inhibition was maximum when the drug was given 1 h before challenge. Passive cutaneous anaphylaxis was always inhibited more potently than histamine-induced cutaneous reaction and serotonin-induced cutaneous reaction by these beta-adrenoceptor agonists. Passive peritoneal anaphylaxis was caused by injecting an antigen intravenously. Isoproterenol administered intravenously immediately before challenge inhibited the reaction significantly. Clenbuterol administered intravenously 0-3 h before challenge also significantly inhibited passive peritoneal anaphylaxis, maximally so when given 1 h before challenge. In vitro IgE-dependent histamine release from sensitized peritoneal mast cells or mesenteric mast cells was not affected by isoproterenol and clenbuterol. Mouse monoclonal IgE, a foreign protein, administered intravenously decreased rapidly in the circulation. About 50% of the mouse IgE given disappeared in 20 min. The decrease of mouse IgE was partly but significantly inhibited by the beta-adrenoceptor agonists, and the inhibition was abolished by simultaneous treatment with propranolol. These results indicate that direct inhibition of mast cell activation does not contribute to the potent inhibition of in vivo allergic reactions in rats by beta-adrenoceptor agonists, and that inhibition of the allergic cutaneous reaction is partially explained by the inhibition of vascular permeability increases caused by mast cell mediators. Penetration of intravenously administered antigen from blood vessels to peripheral tissues to cause mast cell activation might be inhibited by beta-adrenoceptor agonists, and this could play some role in inhibiting intravenous antigen-induced allergic reactions in rats. Clenbuterol exhibited its maximum action with some latency in vivo, suggesting that some time-requiring process may be involved in the manifestation of its action.

Adrenergic beta-Agonists↗

PubMed1997

Expression of presenilin-1 and -2 mRNAs in rat and Alzheimer's disease brains.

Recently, new genetic linkages have been identified for early-onset familial Alzheimer's disease (AD). Mutations have been found in the presenilin (PS)-1 (S182) gene on chromosome 14 and the PS-2 (STM2/E5-a) gene on chromosome 1. We have investigated the distribution of gene expression of both presenilins in normal rat brain, and in human control and AD cases using in situ hybridization histochemistry. In normal rat brain, intense PS-1 mRNA expression was observed predominantly in neurons, particularly hippocampal pyramidal and dentate granular neurons and cerebellar Purkinje and granular neurons. The distribution of intensely expressing PS-2 mRNA cells was similar to that of PS-1, but additional groups in the brain stem and cortex were identified. Faint but significant mRNA expression of both PS genes was detected in white matter. In control human cases, the same neuronal cell types as seen in rat brain expressed both PS mRNAs in the hippocampus and cerebellum. In AD cases, the expression of both mRNAs was markedly decreased in the hippocampus but not in the cerebellum. In addition, PS-2 hybridization showed increased mRNA expression in astrocyte-like cells in affected areas of AD cases. The present data indicate that the PS genes may play important roles in specific neurons in normal brain, and that the decreased expression in neurons in sporadic AD brain may bear some relationship to the pathogenesis.

Alzheimer Disease↗

PubMed1997

Expression of interleukin-1 receptor antagonist protein in post-mortem human brain tissues of Alzheimer's disease and control cases.

The immunohistochemical localization of interleukin-1 receptor antagonist protein (Il-1ra) was examined in brain tissues of neurologically normal controls as well as in cases of Alzheimer's disease (AD) and Pick's disease. In all control cases, immunoreactivity was observed in some normal-appearing neurons in the neocortex and hippocampus. In AD, there appeared to be increased numbers of positively staining neurons, and the staining of individual neurons was somewhat more intense. Il-1ra was additionally expressed in globular deposits in senile plaques and, weakly, in some extracellular neurofibrillary tangles. In Pick's disease, there was similar staining of normal-appearing neurons and intense staining in some degenerating neurons. Using reverse transcriptase-polymerase chain reaction techniques, the mRNA for IL-1ra was detected in cultured IMR-32 human neuroblastoma cells following differentiation with dibutyryl cAMP and bromodeoxyuridine. Taken together, these data suggest that IL-1ra is a product of normal neurons which may be upregulated in some pathological circumstances.

Aged↗

PubMed1997

Immunoglobulin E production in mice by means of contact sensitization with a simple chemical, hapten.

Production of IgE caused by repeated topical application of 2,4-dinitrofluorobenzene (DNFB) to the ears of BALB/c mice was investigated. Ear thickness increased in proportion to the number of applications. Eczematous changes of the skin included marked infiltration of neutrophils, eosinophils, and monocytes and hypertrophy of the epidermis. Ear thickness due to inflammation reached a maximum 24 hours after the second, third, fourth, and fifth applications. The strong expression of interferon-gamma and IL-2 messenger RNA (mRNA) in the skin lesions indicated the participation of Th1 type helper T cells in the delayed-type hypersensitivity reaction. After the fifth application, the mice showed an immediate cutaneous reaction in addition to the delayed-type hypersensitivity reaction. The immediate reaction appeared within 1 hour of application. Hapten-specific IgE also was detected in serum from the mice, and the expression of germline and productive Cepsilon mRNA was detected in cervical lymph nodes, whereas productive Cepsilon mRNA was detected in the spleen. These results indicate that five topical applications of DNFB to the ear produce local eczematous dermatitis and increase serum hapten-specific IgE level in mice. Eczematous dermatitis is mainly caused by Th1 type T cells, and IgE production is mediated by Th2 type T cells in the cervical lymph nodes. In addition, IgE class switching occurs in the cervical nodes and IgE production occurs in both lymph nodes and spleen.

Animals↗

PubMed1997

Long-lasting enhancement of synaptic activity in dissociated cerebral neurons induced by brief exposure to Mg2+-free conditions.

The long-lasting enhancement of periodic clusters of spontaneous excitatory postsynaptic currents (SEPSCs) was examined in dissociated chick cerebral neurons that had been transiently exposed to Mg2+-free solution for 15 min. Since the enhancement was diminished by blockade of synaptic transmission, it clearly depended on synaptic activities. A specific antagonist of N-methyl-D-aspartate receptors (NMDARs) also inhibited the potentiations. Furthermore, the presence of inhibitors of protein and RNA synthesis in the Mg2+-free solution blocked the potentiation. In the potentiated neurons, the frequency of miniature excitatory postsynaptic currents (mEPSPs) increased. In addition, a diffusible molecule(s) that promoted the potentiation appeared to be involved in this phenomenon, since the conditioned medium of Mg2+-free treated neurons enhanced synaptic activity in other dish.

6-Cyano-7-nitroquinoxaline-2,3-dione↗

PubMed1997

Effect of prednisolone on IgE-dependent biphasic cutaneous reaction in BALB/c mice.

1. The effect of prednisolone on IgE-dependent, antigen-induced biphasic cutaneous reaction in BALB/c mice was investigated. 2. The biphasic cutaneous reaction with peak responses at 1 h and 24 h after antigen stimulation was suppressed by prednisolone administered 2 h before the challenge. 3. Although antigen challenge increased the expression of IL-1 beta and TNF-alpha mRNA in the mouse ear, prednisolone did not affect the increase. 4. Anti-IL-1 beta antibodies inhibited the later phase of biphasic cutaneous reaction, whereas anti-TNF-alpha antibodies inhibited both phases of the reaction. 5. Prednisolone inhibited edematous reactions caused by both IL-1 beta and TNF-alpha. 6. Proinflammatory cytokines, such as IL-1 beta and TNF-alpha, participate in the development of the biphasic cutaneous reaction, especially in its later phase, in mice, and prednisolone inhibits the reaction by suppressing the action of cytokines, at least in part.

Animals↗

PubMed1997

Hepatic denervation ameliorates sodium and water retention in experimental cirrhosis in rats.

Increased activity in the hepatic sympathetic nervous system may exacerbate salt and water retention in patients with liver cirrhosis. The aim of this study was to evaluate sodium and water homeostasis in rats with cirrhosis induced by diethylnitrosamine and to investigate the influence of hepatic denervation in this model. Animals were randomized into three groups: diethylnitrosamine-treated rats with (N = 13) and without (N = 8) hepatic denervation and control rats (N = 8). Rats were fed a normal salt diet (0.23% sodium ad libitum). The 24-hr measurements for sodium balance, water balance, and creatinine clearance were performed every two weeks for 12 weeks after surgery. Diethylnitrosamine-induced cirrhosis was confirmed histologically. The cumulative change in sodium balance in the innervated diethylnitrosamine-treated rat increased progressively and was significantly higher than the control during the last four weeks of the study. Meanwhile, rats with hepatic denervation showed significantly smaller changes in cumulative sodium balance at week 12 than those in the innervated group. The cumulative changes in water balance in the innervated group were significantly greater at weeks 10 and 12 than those of the denervated and control group, which remained unchanged throughout the study. Creatinine clearance in the innervated group decreased at weeks 10 and 12 by approximately 70% from baseline (P < 0.05); in contrast, it did not change significantly in the denervated group and control group throughout the study. These results demonstrated that hepatic denervation ameliorates sodium and water retention as well as glomerular function in cirrhosis model in rats.

Animals↗

PubMed1997

Immunohistochemical localization of low-affinity nerve growth factor receptor in the enteric nervous system of adult rats.

The localization of low-affinity nerve growth factor receptor in the enteric nervous system of adult rats has been studied by immunohistochemistry using a monoclonal antibody (clone 192) against the rat receptor. Cryostat and whole-mount sections were stained. By light and confocal microscopy, positive staining in neural structures was found in every part of the gut. In the ganglionic plexus, dense staining was detected in the neuropil surrounding neuronal cell bodies that were themselves devoid of immunoreactivity. Immunoelectron microscopy revealed deposition of reaction products on the outer plasma membranes of both perikarya and processes of neuronal as well as glial cells. Such a selective localization of the receptor in the plasma membrane, but not the cytoplasm, suggests that the mechanisms of receptor-ligand interaction in the gut may differ from those in the brain, where internalization of the receptor is observed in cholinergic cells. The present study provides the morphological basis for future studies designed to elucidate the functional significance of this enteric nervous system receptor. Since it is found in both neuronal and glial cells, it is probably under the influence of a number of trophic factors, including nerve growth factor.

Animals↗

PubMed1997

Changes in force-velocity and power output of upper and lower extremity musculature in young subjects following 20 days bed rest.

Ten healthy sedentary students were exposed to 20 days bed rest (BR) to study the effect of simulated weightlessness on force(F)-velocity(V) characteristics and power(P) output of upper and lower limb movements. F, V and P were measured using a special dynamometer applicable to single joint movements [elbow flexion(EF) and extension(EE), knee flexion(KF) and extension(KE), and hip flexion] or multi-joint movements (squatting). Physiological cross-sectional areas(PCSA) of KF and KE muscles were measured by a magnetic resonance imaging technique. After BR, attenuation in P were observed in lower limb movements (decreased by 19.8-43.6% for squatting, KF and KE), in upper limb movements on the other hand, the decreases in P were not significant (approximately -5% for EF and EE). Decrease in P in lower limb were more pronounced in heavier loaded conditions which were characterized by decreases in both F and V. For KF and KE, decreases in maximal static F (-18.9 to approximately -26.8%) were more pronounced than the decreases observed in the PCSA (approximately -7%), resulting in decreases in specific tension (-12.3 to approximately -22.1%). Neural excitation potentials to generate maximal muscle tension or P might also be influenced by weightlessness.

Adult↗