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Biomedical subjects

M Matsubara

Publications and source records attributed to M Matsubara.

At least 127 records · Page 7Linked to original sources
PubMed1994

The effects of stimulus rates upon median, ulnar and radial nerve somatosensory evoked potentials.

We examined the effect of stimulus rates on the somatosensory evoked potential (SEP) amplitude following stimulation of the median nerve (MN) and the ulnar nerve (UN) at the elbow or wrist, and the radial nerve (RN) at the wrist in 12 normal subjects. We measured the amplitude of frontal (P14-N18-P22-N30) and parietal peaks (P14-N20-P26-N34) at a stimulus rate of 1.1, 3.5 and 5.7 Hz. The amplitude attenuation was found at frontal P22 and N30 and to a lesser degree at parietal N20 and P26 peaks with an increasing stimulus rate from 1.1 to 5.7 Hz. The amplitude attenuation was greatest at the elbow when compared to the wrist stimulation for both MN and UN. The attenuation was least for wrist stimulation for the RN. The UN block by local anesthesia just distal to the stimulus electrode at the elbow abolished the amplitude attenuation caused by the fast stimulus rate. The observed amplitude attenuation with the faster stimulus rate is probably due, in part, to interference from the "secondary" afferent inputs. The secondary afferent inputs arise from peripheral receptor stimulation (muscle, joint and/or cutaneous) as a subsequent effect of efferent volleys initiated from the point of stimulation. The greater number of peripheral receptors being activated as more proximal sites of stimulation in a mixed nerve would result in greater attenuation of the SEP recorded from scalp electrodes. We postulate that the attenuation of frontal peaks by the fast stimulus rate is due to the frontal projection of interfering "secondary" afferent inputs.

Adult↗
PubMed1994

Effects of Chinese herbal medicines on DNA-synthesizing enzyme activities in mammary tumors of mice.

Sho-saiko-to (SST) and Juzen-taiho-to (JTT), Japanese modified Chinese herbal prescriptions, suppressed the activities of thymidylate synthetase and thymidine kinase involved in de novo and salvage pathways for pyrimidine nucleotide synthesis, respectively, in mammary tumors of SHN mice with the reduction of serum prolactin level. These results indicate that SST and JTT may have the antitumor effects on mammary tumors.

Animals↗
PubMed1994

Suppression by kampo medicine, sho-saiko-to, on papillomas induced by 7,12-dimethylbenz(a)anthracene in mice.

Sho-saiko-to (SST) is a Japanese modified, traditional Chinese herbal medicine (Kampo medicine) consisting of seven medical plants. We examined the effects of SST on formation and growth of squamous cell papillomas induced by 7,12-dimethylbenz(a)anthracene application in mouse skin. Chronic oral administration of SST reduced the incidence and growth of papillomas with the reduction of activities of succinate-dehydrogenase and thymidylate synthetase, which were evaluated as the cell viability and DNA synthesis via the de novo pathway, respectively.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1994

Remodeling of neutrophil phospholipids with 15(S)-hydroxyeicosatetraenoic acid inhibits leukotriene B4-induced neutrophil migration across endothelium.

5-Lipoxygenase products, such as leukotrienes, are important stimuli for leukocyte-mediated tissue injury in acute inflammation. 15-Hydroxyeicosatetraenoic acid (15-HETE) is an eicosanoid generated by a variety of cell types via the actions of 15-lipoxygenases and, in addition, cyclooxygenases and epoxygenases. 15-HETE levels are frequently elevated at sites of inflammation, and extracellular 15(S)-HETE is esterified rapidly into neutrophil (PMN) phospholipids in vitro to levels that are comparable with arachidonic acid. We present evidence that remodeling of PMN phospholipids with 15(S)-HETE stereoselectively inhibits PMN migration across endothelium in response to leukotriene B4 (LTB4) and other chemoattractants. Esterified 15(S)-HETE causes a striking reduction in the affinity of LTB4 cell-surface receptors for their ligand and inhibition of LTB4-triggered stimulus-response coupling. As a result of these actions, esterified 15(S)-HETE attenuates the cytoskeletal rearrangements and CD11/CD18-mediated adhesive events that subserve directed locomotion of PMN across endothelium. These observations indicate that products of the 5-lipoxygenase and 15-lipoxygenase pathways can exert counterbalancing influences on PMN trafficking across endothelium. They suggest that 15(S)-HETE may be a potent endogenous inhibitor of PMN-endothelial interactions in vivo and serve to limit or reverse acute inflammation.

Antigens, CD↗
PubMed1994

[A study on MRSA infections and replacement of bacteria. Efficacy of vancomycin-ceftazidime combination therapy].

We analyzed the results of bacteriological tests on patients with MASA infections admitted to Osaka Prefectural Hospital, for the past 10 years. The conclusions obtained are as follows. 1. In our hospital, MRSA infections accounted for 50% or more of all Staphylococcus aureus infections in 1983 and 1984 (in the first half of the 1980's), markedly decreased to about 10% after 1988, because of the preventive measures taken against nosocomial infections and initiation of anti-MRSA treatment. During the latter period, use of antibiotics including third generation cephems was not especially restricted. 2. Glucose non-fermentative Gram-negative rods (GNF-GNR) or yeasts co-isolated with S. aureus were more frequent in MRSA infected patients, than those in MSSA infected patients. 70 to 80% of GNF-GNR were P. aeruginosa. 3. Sensitivities of MRSA to drugs were studied. VCM was most active, followed by arbekacin and rifampicin. Effectiveness against co-isolated GNF-GNR was high with ofloxacin, netilmicin and ceftazidime (CAZ). Therefore, is expected that, to prevent the replacement of opportunistic infections, combination therapies using vancomycin and CAZ would be effective.

Ceftazidime↗
PubMed1994

15-Hydroxyeicosatetraenoic acid inhibits neutrophil migration across cytokine-activated endothelium.

15-hydroxyeicosatetraenoic acid (15-HETE) is an eicosanoid, formed by the actions of 15-lipoxygenase, epoxygenases, and cyclooxygenases on arachidonic acid, whose tissue levels are often elevated during inflammation. The present study demonstrates that 15(S)-HETE is a potent inhibitor of polymorphonuclear neutrophil (PMN) migration across cytokine-activated endothelium in vitro. 15(S)-HETE is rapidly esterified into PMN phospholipids, and we report that 15-(S)-HETE-remodeled PMN displayed blunted adhesion to, and migration across, human endothelial cells that had been activated with either interleukin-1 beta or tumor necrosis factor-alpha Several lines of evidence suggested that 15(S)-HETE inhibited PMN transmigration by attenuating PMN responsiveness to endothelial cell-derived platelet-activating factor (PAF). The inhibitory action of 15(S)-HETE on transmigration was not restricted by the profile of adhesion molecules expressed by cytokine-activated endothelium. Interleukin-1 beta and tumor necrosis factor-alpha induce PAF production by endothelium, and PMN migration across cytokine-activated endothelium was inhibited by a PAF receptor antagonist. PMN migration across endothelium in response to exogenous PAF was dramatically inhibited following exposure of PMN to 15(S)-HETE. Furthermore, 15(S)-HETE-remodeled PMN displayed impaired cytoskeletal and adhesion responses when stimulated by exogenous PAF, two pivotal events in PMN migration across activated endothelium. 15(S)-HETE seemed to attenuate PMN responsiveness to PAF by inhibiting membrane-associated signal transduction events. In keeping with this interpretation, remodeling of PMN phospholipids with 15(S)-HETE was associated with a sixfold reduction in the affinity of specific high-affinity PAF receptors for their ligand and impaired PAF-triggered IP3 generation. In contrast, PMN adhesion responses stimulated by calcium ionophore or activators of protein kinase C remained intact. These results provide further evidence that 15(S)-HETE may be an important endogenous inhibitor of PMN-endothelial cell interaction that serves to limit or reverse neutrophil-mediated inflammation in vivo.

Cell Adhesion↗
PubMed1993

[Plasma lipoprotein(a) levels in patients with hyperthyroidism].

Recently lipoprotein(a) [Lp(a)], which is an atherogenic giant lipoprotein, has been proved to be a major independent risk factor in cardiovascular and cerebrovascular diseases. Therefore, it is important to study the clinical role of the reduction of plasma Lp(a) in atherosclerosis prevention. In this study we examined the role of plasma Lp(a) levels in patients with hyperthyroidism (HT) in which is commonly observed low levels of total and LDL cholesterol. Plasma Lp(a) levels in 6 men and 17 women aged 17 to 67 (mean 36) years with HT ranged from 0.1 to 17.8 (mean +/- SE; 5.3 +/- 1.0) mg/dl. Those of 36 healthy men and 69 healthy women aged 15 to 73 (mean 41) years ranged from 0.2 to 30.2 (10.7 +/- 0.7)mg/dl, and those of 9 men and 26 women aged 17 to 68 (mean 41) years with HT during treatment more than 6 months ranged from 3.6 to 45.7 (11.1 +/- 1.6)mg/dl. The mean values for Lp(a) in HT were significantly lower than those of the healthy subjects (p < 0.001) or HT during treatment (p < 0.025). Those low levels of Lp(a) in patients with HT were normalized after the appropriate treatment (8.9 +/- 1.4 mg/dl, p < 0.05). A significant correlation was noted between the changes of plasma Lp(a) and LDL cholesterol levels in HT before and after treatment (r = 0.62, p < 0.05). In conclusion, we found that plasma Lp(a) was lowered in patients with HT, and those lowered levels were normalized after treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

Analysis of regions essential for the function of chromosomal replicator sequences from Yarrowia lipolytica.

Two DNA segments exhibiting ARS (autonomously replicating sequence) activity in the dimorphic yeast Yarrowia lipolytica were cloned from its chromosome on an integrative LEU2 plasmid. These ARS segments, designated Y1ARS1 and Y1ARS2, conferred on the hybrid plasmids high transformation efficiency and enabled extrachromosomal transmission of the plasmids in 1 or 2 copies per yeast cell under selective conditions. Deletion analysis showed that at least 728-1003 bp for Y1ARS1 and 1377-1629 bp for Y1ARS2 were required for full function. Both of these regions contained two 10/11 matches to an ARS core consensus in Saccharomyces cerevisiae, whereas neither was similar to the S. cerevisiae centromere sequence. Significantly, both Y1ARS elements contained at, or close to, their boundaries a 13 bp sequence, 5'-TATATTCAAGCAA-3', which resembles the cleavage site for topoisomerase II in Drosophila. A central 524 bp ClaI fragment of Y1ARS2 contained four stretches of a 17 bp direct repeat sequence, 5'-GAAAAACAAAAACAGGC-3', and exhibited the electrophoretic behavior typical of bent DNA.

Base Sequence↗
PubMed1993

Support network utilization by breastfeeding mothers.

The Utilization of Support Network Questionnaire (USNQ) was developed to determine how mothers utilize their network for successful breastfeeding. Sixty breastfeeding mothers completed the USNQ. Lactation consultants were the most utilized resources for providing expert information and answering questions. Husbands, friends, or family were important resources for closest personal facets of breastfeeding, including encouraging confidence. At two weeks postpartum, breastfeeding mothers had larger total support scores than non-breastfeeding mothers. USNQ reliably discriminated between professional and personal support for breastfeeding.

Adolescent↗
PubMed1993

Stromal fibroblasts synthesize collagenase and stromelysin during long-term tissue remodeling.

The process of connective tissue remodeling is an important mechanism contributing to tissue morphogenesis in development and homeostasis. Although it has long been known that remodeling tissues actively mediate collagenolysis, little is understood about the molecular mechanisms controlling this cell-regulated process. In this study, we examined the biosynthesis of collagenase and the related metalloproteinase, stromelysin, during remodeling of repair tissue deposited after mechanical injury to the rabbit cornea. Neither enzyme was synthesized by uninjured corneas; however, synthesis and secretion was detectable within one day after injury. Collagenase accumulated in its latent form while stromelysin appeared to be partially activated. Enzymes were synthesized by cells having a fibroblast phenotype. These cells were found within the stroma. New synthesis was correlated with accumulation of enzyme-specific mRNA. Highest levels of enzyme synthesis were observed in the repair tissue. However, stromal cells outside of the repairing area also synthesized both enzymes. The level of synthesis decreased in a gradient radiating from the repair tissue. Total synthetic levels in a given area of cornea were dependent on both the number of cells expressing enzyme and the rate of enzyme synthesis. Synthesis of collagenase was detected in repair tissue as long as nine months after injury. Our findings provide direct support for the hypothesis that new collagenase synthesis by cells in repair tissue is the first step in collagen degradation during long-term tissue remodeling.

Animals↗
PubMed1993

"Loose folding" and "delayed oxidation" procedures successfully applied for refolding of fully reduced hen egg white lysozyme.

Several factors and/or procedures were examined quantitatively to improve the refolding yields of hen egg white lysozyme from its fully denatured and reduced state. Firstly, we found that refolding treatments were better conducted at lower lysozyme concentrations. The refolding yield decreased from 70% to less than 5% by increasing the lysozyme concentration from 1 to 36 microM in the refolding solution, probably due to aggregation. Secondly, in order to reduce the aggregation and improve the efficiency of refolding, we applied the "loose folding" procedure which required the incubation in the presence of about 2 M urea. The refolding of the lysozyme, studied at 17.4 microM, increased the yield to 80% yield in the presence of 2 M urea compared with a 30% yield in the absence of urea. Furthermore, we obtained a dramatic refolding yield of more than 95% in an experiment conducted at a concentration of 1.1 microM lysozyme, in the presence of 2 M urea. Finally, we examined the "delayed oxidation" procedure which meant that conformational folding preceded formation of disulfide bonds. The application of this procedure resulted in increases of 5-10% in the refolding yield. These procedures are expected to be useful in improving the refolding yield of precipitated proteins, for example, formed during recombinant DNA protein syntheses.

Animals↗
PubMed1993

Effects of the immunosuppressant FK506 on a penetrating keratoplasty rejection model in the rat.

PURPOSE: The immunosuppressive effects of FK506 on allogeneic corneal transplantation were tested in a rat model. METHODS: Inbred-strain Lewis rats were used as recipients, and Fisher rats were used as donors. Intraperitoneal injection of FK506 (0.3, 1.0, and 3.0 mg/kg per day) was administered for 2 weeks, and the grafts were inspected by clinical evaluation. Mixed lymphocyte culture assay, using lymphocytes from recipients of penetrating keratoplasty as responder cells and irradiated splenocytes from naive Fisher or Brown Norway as stimulator cells, was used to identify allogeneic stimulation. The rejection process was studied by histology and immunohistochemistry. RESULTS: The rat strain combination developed 100% graft rejection in about 2 weeks after the penetrating keratoplasty. FK506 prolonged the graft survival in a dose-dependent manner, as observed by clinical evaluation. In mixed lymphocyte culture assay, Lewis rats that had been primed to allogeneic stimulation at the time of cornea transplantation presented significant proliferation to Fisher stimulator splenocytes. FK506 suppressed this primed lymphocyte proliferation. Immunohistochemical and histologic studies confirmed the clinical evaluations. Untreated rat corneas, at the second postoperative week, presented a large number of helper/inducer T cells, macrophages, IL-2 receptor-expressing cells, and Ia-antigen-expressing cells. In the same period, FK506-treated rats appeared normal and had no cellular infiltration. Corneas rejected after FK506 cessation had less intense cell infiltration than the control corneas. CONCLUSIONS: These data indicate that FK506 prolonged the corneal graft survival and can be a potentially useful drug in the immunotherapeutic arsenal to suppress corneal graft rejection.

Animals↗
PubMed1993

[Bone mineral loss in patients with chronic obstructive pulmonary disease].

Body weight loss is often observed in patients with chronic obstructive pulmonary disease (COPD). Bone mineral loss has also been reported in COPD, but the mechanisms are not well determined. To elucidate what factors influence on bone mineral content in COPD patients, we measured bone mineral content (BMC) by dual energy X-ray absorptiometry (DXA) (XR-26, Norland), pulmonary function, and ten minute walk distance (TMD) in Japanese elderly male patients with COPD. The subjects were 21 male patients with COPD (72.6 +/- 9.5 years) and 18 age-matched male normal individuals (66.5 +/- 9.5 years). COPD patients showed significantly (p < 0.05) lower BMC (1.82 +/- 0.33, 2.27 +/- 0.35 kg, respectively) compared with age-matched controls. BMC was significantly correlated with body weight and TMD (r = 0.71, r = 0.51, respectively). These results demonstrate that lower body weight and decreased exercise capacity account for the significantly lower bone mineral content of our COPD patients and that COPD patients with body weight loss may be at high risk for osteoporotic fracture.

Absorptiometry, Photon↗
PubMed1993

[Clinical significance of magnetic resonance imaging (MRI) in evaluation of the extension of uterine cervical cancer].

Magnetic resonance imaging (MRI) was performed in 62 patients with uterine cervical cancer and the preoperative MRI findings were compared with the pathological findings following surgery. The surgical stages of 62 patients were 2 at stage 0, 18 at stage Ia, 19 at stage Ib, 9 at stage IIa, 11 at stage IIb, 2 at stage IIIa, and 1 at stage IIIb. The MRI findings in the present study included: (1) the existence of a high intensity area (HIA) in the uterine cervix or minimum thickness of residual normal cervical tissue, (2) necrotic cavity, (3) pyometra, (4) irregular margin of the cervix, (5) parametrial invasion, (6) vaginal invasion, (7) bladder invasion, and (8) lymphnode enlargement. No HIA was observed in any patient with stage 0 or stage Ia, in 8 patients with stage Ib, and in 2 patients with stage IIa, while all patients with cancer tissues greater than 10mm in diameter had a HIA. In 39 patients in whom hysterectomy was undergone without conization, the findings of MRI correlated significantly (r = 0.929, p < 0.001) with the minimum thickness of residual normal cervical tissue by the pathological measurement. When the irregular margin of the cervix was regarded as a disruption of the cervical myometrium by cancer tissue, accuracy was 87%. Furthermore, the degrees of accuracy for parametrial invasion, vaginal invasion and bladder invasion were 92%, 90% and 94%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenocarcinoma↗
PubMed1993

[A combined operation of aortic valve replacement and bullectomy for aortic valve stenosis and giant bulla].

A 61-year-old male with aortic valve stenosis and giant bulla, whose respiratory function was very poor, successfully underwent a combined operation of aortic valve replacement and bullectomy. Firstly aortic valve replacement was performed under cardio-pulmonary bypass, and after coming off bypass, giant bulla was resected via median sternotomy. Postoperative respiratory function was improved remarkably (VC: per-op 1.89 l, post-op 2.53 l, FEV1.0: pre-op 0.74 l, post-op 1.13 l) and also his clinical symptom improved from Hugh-Jones IV. to I. postoperatively.

Aortic Valve↗
PubMed1992

Seroepidemiological survey for antibody to Borrelia burgdorferi in cows.

Antibody to Borrelia burgdorferi was examined in 380 healthy and 38 clinical cases of cows from Hokkaido and Shizuoka in Japan. In healthy animals, IgG and IgM antibody to B. burgdorferi HO14 strain were found in 44 cows (14.6%) and 24 cows (8.0%) from Hokkaido. In contrast, antibody-positive case was not observed except for only 1 case which was IgM positive (1/79: 1.3%) in cows from Shizuoka. Mean antibody levels of healthy animals in Hokkaido and Shizuoka were 0.651 and 0.263 (IgG antibody to HO14 strain), 0.642 and 0.169 (IgG to HP3 strain), 0.613 and 0.367 (IgM to HO14 strain) and 0.582 and 0.286 (IgM to HP3 strain). The differences of the antibody levels between cows from Hokkaido and Shizuoka were significant. Seasonal difference was found in seropositive cows from Hokkaido. The rate of seropositive cows was high in summer (23.4% in June and 11.8% in July) but low in winter (0% in January and February). The pattern was discussed to be associated with activation of ticks. One of 4 cows with arthritis showed significantly higher IgG antibody level than that of healthy cows and cows with some disease, although the serum was collected from Shizuoka where antibody-positive animals for B. burgdorferi were rare among healthy cows. This high IgG antibody may suggest that the arthritis of such cows was caused by infection with B. burgdorferi. Two of 7 cows with unclassified abortion showed positive antibody reaction in Hokkaido. These cases, however, may not be related to the B. burgdorferi infection because the positive rate was similar to those of healthy cows in the same season.

Animals↗
PubMed1992

Collagenolytic/gelatinolytic enzymes in corneal wound healing.

We have documented changes in expression of collagenolytic/gelatinolytic enzymes of the matrix metalloproteinase family (MMP) in healing or ulcerating corneal wounds of rat or rabbit. Correlation of our findings with specific changes in the extracellular matrix of the repair tissue suggests two different roles for the enzymes, MMP-2 and MMP-9. MMP-2 is expressed in undamaged corneal stroma where it may degrade the occasional collagen molecule that becomes damaged. After corneal wounding, expression of this enzyme is increased and much of it appears in the active form. These changes persist for at least seven months, suggesting that MMP-2 is involved in the prolonged process of collagen remodelling in the stromal repair tissue. MMP-9 is expressed in the epithelial layer of repair tissue with a timing suggesting it might participate in controlling resynthesis of the basement membrane. MMP-9 also appears to be involved in degradation of the epithelial basement membrane that precedes corneal ulceration.

Animals↗