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Biomedical subjects

S Matsuda

Publications and source records attributed to S Matsuda.

At least 307 records · Page 17Linked to original sources
PubMed1996

Dorsal root ganglion neuron development in chick and rat.

The aim of this study was to compare the morphological development of dorsal root ganglion neurons in embryonic and early postnatal chicks and rats. The three-dimensional architecture of neurons was observed in ganglia in situ and in dissociated neurons by scanning electron microscopy after removal of the capsule and connective tissue. The percentages of neurons at different developmental stages were determined. The general morphological changes in the chick resembled those in the rat but the timing was different. In both chick and rat, the majority of neurons were bipolar at early stages of development (embryonic day 6 in chick and day 14 in rats) and later underwent pseudo-unipolarization to become mostly unipolar neurons at hatching or birth. This maturation event started at an earlier stage in chick embryos than in rats, with 57% unipolar neurons in chick and only 7% in rat on embryonic day 14. However, just after hatching or birth, at day 22 of development, a larger proportion of immature unipolar neurons remained in chicks (13%) than in rats (3%). We conclude that these differences should be taken into consideration in designing experiments on dorsal root ganglion neurons grown in tissue culture.

Animals↗
PubMed1996

Therapeutic effect of secretin in patients with jaundice; double-blind placebo-controlled multicentric trial.

Secretin, a gastrointestinal hormone, has been shown to have a potent choleretic effect. Having already obtained some beneficial effects with secretin in patients with intrahepatic cholestasis, we sought to confirm its effects in a double-blind placebo-controlled study in patients with mild jaundice after acute or during chronic hepatitis, where total bilirubin level was in excess of 4.0 mg/dl for 3 days or more. Patients with primary biliary cirrhosis (PBC), primary sclerosing cholangitis (PSC), and familiar hyperbilirubinemia were excluded from the study. Ninety-three patients were included in this analysis, but the final evaluation covered 69 of them. No statistically significant differences were found in the reduction of serum bilirubin levels between secretin and placebo groups. As a number of patients with liver cirrhosis had been included, the subjects were subdivided into one group with cholestasis in hepatitis and one with liver cirrhosis. In the subgroup of cirrhotic patients who received secretin, serum levels of AST were significantly increased compared with the placebo group. However, since the choleretic effect of secretin is unique, further studies seem to be warranted.

Adolescent↗
PubMed1996

Ginseng root prevents learning disability and neuronal loss in gerbils with 5-minute forebrain ischemia.

The present study was designed to investigate the possible neuroprotective activity of ginseng roots in 5-min ischemic gerbils using a step-down passive avoidance task and subsequent neuron and synapse counts in the hippocampal CA1 region. The following drugs were administered for 7 days before the induced ischemia: red ginseng powder (RGP), crude ginseng saponin (CGS), crude ginseng non-saponin (CGNS), and pure ginsenosides Rb1, Rg1 and Ro. Oral administration of RGP significantly prevented the ischemia-induced decrease in response latency, as determined by the passive avoidance test, and rescued a significant number of ischemic hippocampal CA1 pyramidal neurons in a dose-dependent manner. Intraperitoneal injections of CGS exhibited a similar neuroprotective effect. CGNS had a significant but less potent protective effect against impaired passive avoidance task and degeneration of hippocampal CA1 neurons. Ginsenoside Rb1 significantly prolonged the response latency of ischemic gerbils and rescued a significant number of ischemic CA1 pyramidal neurons, whereas ginsenosides Rg1 and Ro were ineffective. Postischemic treatment with RGP, CGS or ginsenoside Rb1 was ineffective. The neuroprotective activities of RGP, CGS and ginsenoside Rb1 were confirmed by electron microscopy counts of synapses in individual strata of the CA1 field of ischemic gerbils pretreated with the drugs. These findings suggest that RGP and CGS are effective in the prevention of delayed neuronal death, and that ginsenoside Rb1 is one of the neuroprotective molecules within ginseng root.

Animals↗
PubMed1996

The role of remaining presynaptic terminals in the hippocampal CA1 after selective neuronal death: ischemia-induced glutamate efflux.

Following selective neuronal death, numerous presynaptic terminals maintain their structural integrity in the brain region. The role that these remaining presynaptic terminals play in the brain region showing selective neuronal death is not known. In the present study, we investigated the possibility that brief transient ischemia induces an excessive release of glutamate from the remaining presynaptic terminals, which then spreads by diffusion. The glutamate could act as an excitotoxin and be a pathogenic factor in the local injured brain region. Transient ischemia of 3.5 min duration was used in the gerbil as a pretreatment to obtain hippocampal CA1 in which most of postsynaptic neurons were eliminated but numerous presynaptic terminals remained normal. At 10-14 days after the pretreatment, brain microdialysis experiments were performed in vivo in the CA1 to measure the levels of extracellular glutamate induced by 5 min ischemia. Prior to 5 min ischemia the basal concentration of glutamate in the CA1 was the same as that observed in gerbils that had been subjected to sham pretreatment. During 5 min ischemia, no significant increase in glutamate was induced in the CA1 which showed selective neuronal death. However, a massive increase in glutamate was induced in the CA1 of the sham-pretreated gerbils. These results suggest that the remaining presynaptic terminals are unlikely to play a pathogenic role in the CA1 after selective neuronal death has occurred.

Animals↗
PubMed1996

Regulatory effects of health examination programs on medical expenditures for the elderly in Japan.

In order to evaluate if there is any correlation between the use of general medical examination programs organized by each community under the Health Service Law for the Elderly, and the medical expenditures for the elderly, an analysis was conducted based on 97 communal data of Fukuoka prefecture, Japan in 1991. According to the results, the use of health examinations showed a statistically significant negative correlation with the medical expenditures for the elderly both for in- and outpatient services. The analysis of the medical expenditure components has clarified that this negative correlation is mainly due to the low utilization rate of services at medical facilities among the communities with a high participation rate in the examination. A part of this low utilization rate could be explained by the complementary effect of the examination program as an alternative for the elderly instead of going to a medical facility for consultation. The present result suggests that a community health service program could decrease the demand for medical services of the elderly.

Aged↗
PubMed1996

The effects of proteins on [Ca2+] measurement: different effects on fluorescent and NMR methods.

Previous reports showed that the presence of proteins shifts the apparent dissociation constant (Kd) of a fluorescent dye indicator to Ca2+. To elucidate the sensitivity of Kd of an NMR-sensitive Ca2+ indicator, 5-fluoro-1,2-bis(2-amino-phenoxy)ethane N,N,N'N'-tetraacetic acid (5F-BAPTA) to proteins, and compare with that of a dye indicator, Fura-2, we measured Kd of Fura-2 or 5F-BAPTA using Ca-EGTA buffer with or without proteins. Aldolase (ALD) or bovine cardiac protein (BCP) extracted from bovine hearts was used at concentrations of 10, 25, or 50 mg/ml. ALD significantly increased the apparent Kd of Fura-2 to Ca2+ from 164.1 +/- 5.6 nM (mean +/- SE, N = 8) to 757.2 +/- 2.1 nM (n = 4, P < 0.05) at the concentration of 50 mg/ml. In contrast, Kd of 5F-BAPTA was not markedly changed by ALD (298.4 +/- 3. nM without ALD (n = 8), 385.1 +/- 2.7 nM (n = 4) with 50 mg/ml ALD). BCP (50 mg/ml) also significantly increased Kd of Fura-2 (928.5 +/- 3.3 nM, n = 4, P < 0.05), but did not change Kd of 5F-BAPTA (316.0 +/- 2.9 nM, n = 4). These results indicate that Kd of 5F-BAPTA is much less sensitive to the presence of proteins than Fura-2, and that 19F-NMR coupled with 5F-BAPTA is a more robust method to measure intracellular Ca2+ concentration than a fluorescent method with Fura-2.

Animals↗
PubMed1996

Dissociation of early and late protective immunity to the nematode Nippostrongylus brasiliensis in Brown Norway and Fischer-344 rats.

Worm expulsion of, and IgE and interferon (IFN)-gamma responses to, Nippostrongylus brasiliensis were studied in 2 rat strains, Brown Norway (BN) and Fischer (F)-344. BN rats expelled the majority of worms by day 14 post-infection (p.i.) with approximately 6% of worms surviving for at least 3 weeks. In F-344 rats, worm expulsion was delayed by 2 days relative to that in BN, while the numbers of residual worms were significantly fewer than in BN, suggesting that different immune mechanisms are involved in early and late phases of immunity. Total serum IgE, as well as in vitro IgE production by mesenteric lymph node (MLN) cells, was increased 2 weeks p.i., the levels being markedly higher in BN than in F-344 rats. Serum rat mast cell protease II was also increased more significantly in BN than in F-344 rats. In contrast, production of IgG2a and IFN-gamma by MLN and spleen cells was found to be higher in F-344 than in BN rats. These results indicate that the early worm expulsion is correlated with the host IgE and mast cell responsiveness, whereas the persistence of infection in the late period may be controlled by different immune mechanisms.

Animals↗
PubMed1996

Lung granulomatous response induced by infection with the intestinal nematode Nippostrongylus brasiliensis is suppressed in mast cell-deficient Ws/Ws rats.

Certain nematode infections induce eosinophil infiltration and granulomatous responses in the lungs. To examine the role of mast cells in the development of lung lesions, normal +/+ and genetically mast cell-deficient Ws/Ws rats were infected with the nematode Nippostrongylus brasiliensis. In +/+ rats, numbers of eosinophils in bronchoalveolar lavage fluid (BALF) increased significantly 3-7 days after infection, and granulomatous responses composed of histiocytes/ macrophages and multinucleate giant cells were triggered in the lungs 3-14 days after infection. Challenge infection, which was carried out on day 28 after primary infection, induced much higher levels of granulomatous response than after primary infection, suggesting that the response is mediated at least in part by an immunological mechanism. In Ws/Ws rats, both the eosinophil percentage in BALF and the size of the granulomas in the lungs were significantly smaller than in +/+ rats after primary as well as after challenge infection. The amount of rat mast cell protease (RMCP) II in +/+ rat BALF was increased 1 day after primary infection and more significantly after challenge infection, suggesting that lung mucosal mast cells were activated more markedly after the challenge infection. In Ws/Ws rats, RMCP II was undetectable throughout the observation period. The time course of nematode migration in the lungs did not differ in +/+ and Ws/Ws rats. These results suggest that mast cell activation might be relevant to eosinophil infiltration and granulomatous response in the lungs, although the responses do not affect lung migration of the nematode.

Animals↗
PubMed1996

Prosaposin facilitates sciatic nerve regeneration in vivo.

Prosaposin, a multifunctional protein, is the precursor of saposins, which activate sphingolipid hydrolases. In addition to acting as a precursor for saposins, prosaposin has been shown to rescue hippocampal CA1 neurons from lethal ischemic damage in vivo and to promote neurite extension of neuroblastoma cells in vitro. Here we show that prosaposin, when added to a collagen-filled nerve guide after sciatic nerve transection in guinea pigs, increased dramatically the number of regenerating nerve fibers within the guide. To identify the target neurons of prosaposin during peripheral nerve regeneration, we determined the degree of atrophy and chromatolysis of neurons in the spinal anterior horn and dorsal root ganglia on the prosaposin-treated and untreated side. The effect of prosaposin on large spinal neurons and small neurons of the dorsal root ganglion was more conspicuous. Subsequent immunohistochemistry demonstrated that the atrophy of cholinergic large neurons in the anterior horn is prevented to significant extent by prosaposin treatment. These findings suggest that prosaposin promotes peripheral nerve regeneration by acting on alpha-motor neurons in the anterior horn and on small sensory neurons in the dorsal root ganglion. The present study raises the possibility of using prosaposin as a tool for the treatment of peripheral nerve injuries.

Animals↗
PubMed1996

A hydrophilic peptide comprising 18 amino acid residues of the prosaposin sequence has neurotrophic activity in vitro and in vivo.

Prosaposin, a 517-amino-acid glycoprotein, not only acts as the precursor of saposin A, B, C, and D but also possesses neurotrophic activity to rescue hippocampal CA1 neurons from ischemic damage in vivo and to promote neurite extension of neuroblastoma cells in vitro. Recently, the trophic activity of prosaposin on human neuroblastoma cells has been shown to reside in the NH2-terminal hydrophilic sequence (LIDNNRTEEILY) of the human saposin C. Here we show that prosaposin, saposin C, and a peptide comprising the 18-amino-acid sequence (18-mer peptide; LSELIINNATEELLIKGL) located in the NH2-terminal hydrophilic sequence of the rat saposin C-domain promoted survival and neurite outgrowth of cultured rat hippocampal neurons in a dose-dependent manner. Moreover, infusion for 7 days of the 18-mer peptide into the lateral ventricle of gerbils, starting either 2 h before or immediately after 3 min of forebrain ischemia, protected ischemia-induced learning disability and hippocampal CA1 neuronal loss. Thus, we ascribe the in vitro and in vivo trophic actions of prosaposin on hippocampal neurons to the linear 18-mer sequence and raise the possibility that this peptide can be used as an agent for the treatment of forebrain ischemic damage.

Amino Acid Sequence↗
PubMed1996

The relationship between lipoprotein(a) and low density lipoprotein receptors during the treatment of hyperthyroidism.

To determine whether the low density lipoprotein (LDL) receptor pathway is involved in the catabolism of plasma lipoprotein (a) [Lp(a)], serum lipids, Lp(a), and LDL receptor activity were measured in seven patients with hyperthyroidism before and after methimazole treatment given hyperthyroidism is associated with enhanced LDL receptor activity. LDL receptor activity in patients was estimated by the equation using the serum concentrations of apolipoprotein (apo) B and C-II. When euthyroidism was achieved after treatment, not only did serum total cholesterol, high density lipoprotein-cholesterol, apo B, and LDL-cholesterol (LDL-Ch) levels rise, but Lp(a) significantly increased and calculated LDL receptor activity significantly decreased. The changes in LDL receptor activity were significantly correlated with the changes in LDL-Ch as expected, but not with changes in Lp(a). These results suggest that the serum concentration of Lp(a) is lowered in hyperthyroidism, probably by a mechanism other than the enhanced activity of the LDL receptor, and that the LDL receptor pathway is involved in the catabolism of Lp(a) to a limited extent.

Apolipoproteins↗
PubMed1996

[Isolation and analysis of amino acid sequence of V3 region of HIV-1 from patients with HIV-infection in Hiroshima].

Isolation of HIV-1 was tried in PBMCs separated from 27 blood samples which were sent to Hiroshima Prefectural Institute for Health & Environment Science for anti-HIV antibody-test. 18 samples were positive for HIV-isolation (4 samples were Rapid/High type, 12 samples were Slow/Low type and 2 samples were intermediate). Compared with clinical stages of patients, samples from patients in CDC-II were 64% (14/22) positive and those in CDC-IV were 100% (3/ 3) positive in HIV-isolation. Improvement of the methods is to be required to isolate HIV from the samples of patient in the latent phase. Removal of CD8 positive cells from PBMCs of patients did not affect the efficiency of HIV-isolation by our methods. Three parts in amino acid sequence of V3 region in proviruses were different between Rapid/High type isolated and Slow/Low type isolates. The difference of amino acid may be related to the different phenotypes of the two viruses.

Amino Acid Sequence↗
PubMed1996

An analysis of the Vietnamese system of occupational safety and health and setting priorities with the analytical hierarchy process.

OBJECTIVE: There were two objectives. The first was to describe the Vietnamese system of occupational safety and health (OSH) and its problems. The second was to evaluate priorities among future OSH policies by the analytical hierarchy process (AHP). METHODS: The Vietnamese OSH system was analysed in detail mainly based on various official documents. After the OSH problems in Vietnam were identified through discussions with Vietnamese OSH specialists they were given priorities in five different OSH policies, which were evaluated by the AHP. RESULTS AND CONCLUSION: The OSH system in Vietnam is in theory well organised: the government has established fundamental laws and has organised the OSH administrative system from the central to the grassroots level. However, this system does not work sufficiently well to improve working conditions. According to discussions with Vietnamese OSH specialists, four factors associated with OSH problems in Vietnam were evaluated: shortage of materials and manpower, inadequate OSH information system, inappropriate OSH administrative system, and poor awareness of workers and employers about the OSH problems. Considering the relative importance of these four factors, the priorities within five policies were evaluated by the AHP technique. The results showed that the most important change needed was reorganisation of the OSH administrative system, followed by OSH education for workers and employers, training of personnel in OSH services, improvement of OSH research activity, and the establishment of an adequate OSH information system. It is expected that developed countries will help the Vietnamese government to implement these programmes.

Decision Support Techniques↗
PubMed1996

A comparative study of fatigue complaints among assembly line workers employed in the two electronic factories in Vietnam.

A cross-sectional study concerning working conditions and the fatigue complaints of assembly line workers employed in two different electronic factories (A and B) in Vietnam was conducted from August to September 1994. While general working conditions, such as noise, dust, heat and lighting, were worse in Factory B, the prevalence rate of the subjective fatigue after working time was significantly higher among workers in Factory A. Fatigue symptoms in category I (Drowsiness and dullness) were particularly apparent among workers in Factory A. More interestingly, one-third of workers in Factory A complained of stiff shoulders and low back pain. Our field observation results suggest that the ergonomic inappropriateness of the assembly line in Factory A, may be causing a high rate of subjective fatigue among workers.

Adult↗
PubMed1996

Effects of earplugs on catecholamine and cortisol excretion in noise-exposed textile workers.

To investigate physiological and psychological effects of industrial noise, a survey was performed on 50 female workers exposed to machinery noise [93-100 dB(A)] (noise group) and 25 female workers in less-noisy environments [71-75 dB(A)] (control group) in a textile factory in Vietnam. Urine was collected for analysis of catecholamines and cortisol. The subjects were also asked to fill out a questionnaire. Each subject was examined over 2 working days. The workers in the noise group were asked to put earplugs in their ears during the working hours of the 2nd day. On the 1st day without earplugs, urinary excretion of catecholamines in the noise group were greater than those in the control group. Cortisol in urine showed a similar tendency. Differences in catecholamine excretion between the noise group and the control group decreased on the 2nd day when the earplugs were used for attenuation of noise level in the noise group. Frequency of subjective fatigue symptoms was lower on the 2nd day than that on the 1st day in noise group, while the control group showed almost no day-difference. The results indicate that the catecholamine response to noise in workers was reduced through the use of earplugs.

Adult↗
PubMed1996

[Polyangiitis overlap syndrome with multiple pulmonary aneurysms and renal vascular hypertension].

A 37-year-old man with multiple nodules on a chest X-ray film, hypertension, and proteinuria was admitted to our hospital in September, 1993. Thirteen years earlier, he had been admitted to another hospital because of bloody sputum, fever, and dyspnea. He also had slight oral aphthae and slight iridocyclitis. A chest X-ray film at that time showed bilateral diffuse reticular shadows, and his illness was diagnosed as acute interstitial pneumonitis. Since that time, he had been continuously receiving tapering doses of prednisolone. His chest symptoms were relieved, and the findings on the chest X-ray film resolved with that treatment. In 1993, he also had positive tests for HBs antigen and for HLA-B51, and he was found to have renal vascular hypertension. Chest CT films and a pulmonary angiogram showed multiple aneurysms and occlusions of pulmonary arteries. A renal angiogram showed multiple intraparenchymal aneurysms of renal arteries. A specimen taken by open-lung biopsy showed healed endoarteritis obliterans of muscular arteries and no alveolitis. His illness was diagnosed as polyangiitis overlap syndrome, because of the unclassified systemic necrotizing vasculitis.

Adult↗
PubMed1996

[Comparative studies on activities of antimicrobial agents against causative organisms isolated from patients with urinary tract infections (1994). I. Susceptibility distribution].

The frequencies of isolation and susceptibilities to antimicrobial agents were investigated on 567 bacterial strains isolated from patients with urinary tract infections in 10 hospitals during the period of June 1994 to May 1995. Of the above total bacterial isolates, Gram-positive bacteria accounted for 26.8% and a majority of them were Enterococcus faecalis. Gram-negative bacteria accounted for 73.2% and most of them were Escherichia coli. 1. Enterococcus faecalis. Ampicillin (ABPC) and imipenem (IPM) showed the highest activities against E. faecalis isolated from patients with urinary tract infections. The MIC90s of them were 1 microgram/ml. Vancomycin (VCM) was also active with the MIC90 of 2 micrograms/ml. Piperacillin (PIPC) and biapenem (BIPM) were also active with the MIC90s of 4 micrograms/ml and 8 micrograms/ml, respectively. The others were not so active with the MIC90s of 16 micrograms/ml or above. 2. Staphylococcus aureus including MRSA. VCM showed the highest activities against S. aureus isolated from patients with urinary tract infections. Its MIC90 was 1 microgram/ml against both S. aureus and MRSA. Arbekacin (ABK) was also active with the MIC90 of 2 micrograms/ml. The others except minocycline (MINO) were not so active with the MIC90s of 64 micrograms/ml or above. 3. Staphylococcus epidermidis. MINO showed the strongest activity against S. epidermidis isolated from patients with urinary tract infections. Its MIC90 was 0.25 microgram/ml. ABK was also active with the MIC90 of 1 microgram/ml. Cephems were active with the MIC90s of 2 approximately 16 micrograms/ml, but penicillins and quinolones were not so active with the MIC90s and 64 approximately 128 micrograms/ml. 4. Citrobacter freundii. Gentamicin (GM) showed the highest activities against C. freundii isolated from patients with urinary tract infections. Its MIC90 was 1 microgram/ml. IPM was also active with the MIC90 of 2 micrograms/ml. Cefpirome (CPR) and cefozopran (CZOP) were also active with the MIC90s of 4 micrograms/ml and 8 micrograms/ml. The others were not so active with the MIC90s of 32 micrograms/ml or above. 5. Enterobacter cloacae. IPM showed the highest activities against E. cloacae. Its MIC90 was 0.5 microgram/ml. GM and amikacin (AMK), ciprofloxacin (CPFX) and tosulfloxacin (TFLX) were also active with the MIC90s of 4 micrograms/ml. Penicillins and cephems except latamoxef (LMOX), cefmenoxime (CMX), CPR and CZOP showed lower activities with the MIC90s of 256 micrograms/ml or above. 6. Escherichia coli. Most of antimicrobial agents were active against E. coli. CPR, CZOP, IPM, carumonam (CRMN), CPFX and TFLX showed the highest activities against E. coli. The MIC90s of them were 0.125 microgram/ml or below. Cefotiam (CTM), flomoxef (FMOX) CMX, ceftazidime (CAZ), and LMOX were also active with the MIC90s of 0.25 microgram/ml. Penicillins were not so active with the MIC90s of 128 micrograms/ml or above. 7. Klebsiella pneumoniae. CRMN showed the highest activities against K. pneumoniae. Its MIC90 was < or = 0.125 microgram/ml. CZOP was also active with the MIC90 of 0.25 microgram/ml. Penicillins were not so active with the MIC90s of 128 micrograms/ml or above. 8. Proteus mirabilis. P. mirabilis was susceptible to a majority of drugs. CMX, CAZ, LMOX, CRP, cefpodoxime (CPDX), CRMN, CPFX and TFLX showed the highest activities against P. mirabilis isolated from patients with urinary tract infections. The MIC90s of them were 0.125 microgram/ml or below. MINO was not so active with the MIC90 of 128 micrograms/ml. 9. Pseudomonas aeruginosa. Most of the agents were not so active against P. aeruginosa. IPM showed MIC90 of 8 micrograms/ml. The others were not so active with the MIC90s of 16 micrograms/ml or above. CPFX showed MIC50 of 0.5 microgram/ml.

Anti-Bacterial Agents↗