Biomedical subjects

M Yoshioka

Publications and source records attributed to M Yoshioka.

At least 19 recordsLinked to original sources

PubMed1995

Immunological characterization and localization of a Porphyromonas gingivalis BApNA-hydrolyzing protease possessing hemagglutinating activity.

A monoclonal antibody (mAb-PC) was produced against a BA pNA-hydrolyzing protease possessing hemagglutinating activity (Pase-C) from Porphyromonas gingivalis. Other P. gingivalis BA pNA-hydrolyzing enzymes (Pase-B and Pase-S) did not react with this antibody. By ELISA or SDS-PAGE and Western immunoblotting analysis, mAb-PC recognized all P. gingivalis and P. endodontalis strains tested but did not recognize other members of the Porphyromonas genus nor other putative periodontopathogenic organisms. Pase-C, extracellular vesicles (ECV) and human strains of P. gingivalis showed two major immunoreactive bands (44 kDa and 40 kDa), whereas a different pattern was obtained with animal strains of P. gingivalis. Biotinylarginyl chloromethane, an irreversible inhibitor of trypsin-like proteases, did not affect the reactivity of Pase-C with mAb-PC on immunoblot. By reversed-phase electronmicroscopy following immunogold labeling, the antibody was shown to bind to the cell surface of P. gingivalis. mAb-PC inhibited the hemagglutinating activity of both P. gingivalis cells and ECV whereas a monoclonal antibody against LPS of P. gingivalis did not. These results suggest that Pase-C is located on the cell surface of P. gingivalis and may participate in erythrocyte binding.

Animals↗

PubMed1995

Steviol and steviol-glycoside: glucosyltransferase activities in Stevia rebaudiana Bertoni--purification and partial characterization.

The leaves of Stevia rebaudiana Bertoni contain sweet compounds which are glycosides of diterpene derivative steviol (ent-13-hydroxykaur-16-en-19-oic acid). Its main constituents are stevioside (triglucosylated steviol; 13-O-beta-sophorosyl-19-O-beta-glucosyl-steviol) and rebaudioside-A (tetraglucosylated steviol; 2'-O-beta-glucosyl-13-O-beta-sophorosyl-19-O-beta-glucosyl-stev iol). From the extracts of S. rebaudiana Bertoni, two glucosyltransferases (GTases I and IIB) acting on steviol and steviol-glycosides were isolated, and another distinct activity (GTase IIA) acting on steviol was detected. Purified GTase I (subunit M(r) 24,600) catalyzed glucose transfer from UDP-glucose to steviol and steviolmonoside (steviol-13-O-glucopyranoside), but not to other steviol-glycosides. Apparent Km values were 71.4 microM for steviol and 360 microM for UDP-glucose. GTase IIB (subunit M(r) 30,700) showed a broad substrate specificity, acting on steviol, steviolmonoside, steviolbioside (13-O-beta-sophorosyl-steviol), and stevioside. Apparent Km values were 182 microM for steviol, 44 microM for steviolbioside, 95 microM for stevioside, and 385 microM for UDP-glucose. The two enzymes had a similar optimum pH at 6.5. They also acted effectively on ubiquitous flavonol aglycones, quercetin, and kaempferol and utilized kaempferol at a higher rate than steviol and steviol-glycosides. The apparent Km values of GTase I and IIB for kaempferol were 12 and 31 microM, respectively.

Chromatography, Gel↗

PubMed1995

Pharmacological characterization of alpha 2-adrenoceptor regulated serotonin release in the rat hippocampus.

The purpose of the present study was to confirm the functional regulation by alpha 2-adrenoceptors of the release of serotonin (5-HT) from the rat hippocampus in vivo. Under several pharmacological conditions, extracellular levels of 5-HT were estimated by assaying its concentrations in the perfusate by high performance liquid chromatography with electrochemical detection. Extracellular 5-HT in the hippocampus was reduced by tetrodotoxin (10 microM) co-perfusion, but increased by perfusion of a selective 5-HT re-uptake inhibitor, fluoxetine (10 microM). Addition of potassium (K+, 120 mM) to the perfusion fluid evoked an approximately 3-fold increase in 5-HT release. When the alpha 2-adrenoceptor agonist UK14,304 (0.1-10 microM) was added to the perfusion solution, the K(+)-evoked 5-HT release was significantly inhibited in a concentration-dependent manner. This inhibitory action of UK14,304 was reversed by pretreatment with an alpha 2-adrenoceptor antagonist, idazoxan (5 mg/kg, i.p.). In rats which were catecholaminergically denervated with 6-hydroxydopamine, UK14,304 (10 microM) still inhibited the K(+)-evoked 5-HT release. Treatment with pertussis toxin (PTX) did not alter the K(+)-evoked release of 5-HT but abolished the inhibitory effect of UK14,304. These findings suggest that 5-HT release is functionally modulated via alpha 2-adrenoceptors located on the serotonergic nerve terminals in the rat hippocampus and furthermore, the possibility that the inhibitory of alpha 2-adrenoceptors is linked to G-proteins which are substrates of PTX.

Adrenergic alpha-2 Receptor Agonists↗

PubMed1995

Plasma adenosine concentrations are elevated in Dahl salt-sensitive rats.

We measured plasma levels of adenosine in Dahl salt-sensitive rats (DS) and Dahl salt-resistant rats (DR) to examine the potential role of adenosine in cardiovascular regulation in this type of hypertension. Plasma adenosine concentrations were significantly higher in DS than in DR. The NaCl content in the diet did not affect plasma adenosine concentration in either DS or DR. Significant positive correlation was found between adenosine concentrations and systolic blood pressure when the data for DS and DR were analyzed together. These results suggest that adenosine may play an important role in the pathophysiology of hypertension in DS.

Adenosine↗

PubMed1995

Genetic identity of Fukuyama-type congenital muscular dystrophy and Walker-Warburg syndrome.

Both Fukuyama-type congenital muscular dystrophy (FCMD) and Walker-Warburg syndrome (WWS) are unusual genetic syndromes consisting of congenital muscular dystrophy and complex malformations of the brain and eye. It has been intensively discussed whether FCMD and WWS belong to the same disease entity or not. We analyzed a family in which 3 siblings were affected with either FCMD or WWS by using polymorphic microsatellites flanking the FCMD locus on chromosome 9q31-33. The results suggested that both FCMD and WWS siblings shared the identical combination of mutations on either allele of the FCMD locus. FCMD and WWS could be "genetically" identical.

Abnormalities, Multiple↗

PubMed1995

Inhibition of indomethacin crystallization in poly(vinylpyrrolidone) coprecipitates.

Differential scanning calorimetry and powder X-ray diffraction studies have been carried out with amorphous coprecipitates of indomethacin and poly(vinylpyrrolidone), PVP, to measure the glass transition temperature, Tg, as a function of mixture composition and the nonisothermal and isothermal crystallization of the indomethacin. Values of Tg as a function of mixture composition followed the ideal Gordon-Taylor equation up to about 50% w/w PVP. Inhibition of crystallization occurred at levels as low as 5% PVP and very significant inhibition was observed at and above 20% PVP. Inhibition of crystallization of indomethacin in the absence of PVP required a storage temperature 40-50 degrees C below Tg, whereas comparable inhibition with PVP was observed at storage temperatures 5 degrees C above Tg. This suggests that the inhibition of indomethacin crystallization by PVP may involve mechanisms other than just the general antiplasticizing effect (raising Tg) by PVP.

Calorimetry, Differential Scanning↗

PubMed1995

HIV-1 heterogeneity and cytokines. Neuropathogenesis.

Mild manifestations (HIV-1 associated minor cognitive/motor disorder), severe manifestations (HIV-1 associated dementia complex and HIV-1 associated myelopathy), and sensory neuropathy are consequences of HIV-1 infection. Our goal is to elucidate the role of HIV-1 in the complications of AIDS including cytokine immunopathology and HIV-1 DNA sequence variants. We have examined the brain and sensory ganglia from 60 AIDS patients and 20 seronegative controls using PCR, DNA sequencing of the HIV-1 envelope protein (env), in situ hybridization (ISH), and immunohistochemistry (IHC). Using our combined ISH-IHC technique, we could identify different types of cells and HIV-1 simultaneously in cryostat and paraffin sections. We found HIV-1 predominantly in macrophage/microglia in brain. In dorsal root ganglia (DRG) we found rare macrophages infected with HIV-1 and neurons and interstitial cells (including macrophages) which were apoptotic. Cytokines were detected in mononuclear and endothelial cells near neurons. We achieved single copy sensitivity detecting HIV-1 in nervous tissue using nested PCR. We sequenced HIV-1, DNA from 3 intravenous drug users (IDUs): from brain, CSF, and blood. PCR amplification was followed by cloning and then sequencing the HIV-1 insert: V1-V5 regions of the envelope (env) gene. We found that the env genes had increased sequence variation compared to the literature, cDNA sequences derived from RNA were less heterogeneous than clones derived from DNA from the same specimens, clones derived from brain are more closely related (show restricted heterogeneity) compared to clones from blood and CSF from the same patients. Patient 149 clones we examined to date did not correspond to any of the designated subtypes (A-F) of HIV-1 based on the DNA sequences of the C2-V3 regions. Finally, the HIV-1 RNA produced in these tissues is derived from a minority of DNA clones. Although HIV-1 infected macrophages are not entirely responsible for pathology in the brain and less so in sensory ganglia, some of the products of infection, cytokines, are more widespread in these tissues. Furthermore, HIV-1 strains infecting the brain appear to exhibit restricted heterogeneity compared to autologous CSF and blood and these strains may be associated with cytokines and pathology. HIV-1 strains that infect nervous tissue and cytokines produced in this tissue may effect neuropathogenesis, in vivo, in spite of low levels of local HIV-1 infection. We attempt to delineate, here, common sequence variations in HIV-1 isolates in the hope of developing future therapeutic strategies.

AIDS Dementia Complex↗

PubMed1995

Conjugated bile salts regulate turnover of rat intestinal brush border membrane hydrolases.

The mechanisms whereby the conjugated bile salts regulate the activities of the brush border membrane hydrolases and its physiological significance were investigated in rat small intestine, and comparisons were made with the action of pancreatic protease. Rat brush border membrane proteins were metabolically labeled with [35S]methionine, and isolated brush border membrane was incubated with taurocholate or pancreatic elastase. The activity of solubilized hydrolases was assayed and the molecular forms of the hydrolases were examined by SDS-PAGE. The activity and protein bands of alkaline phosphatase and sucrase-isomaltase were solubilized by taurocholate, while alkaline phosphatase was not solubilized by elastase. Solubilized sucrase-isomaltase molecules were proteolytically degraded by elastase, whereas the intact molecule of sucrase-isomaltase was solubilized by taurocholate. Next the physiological role of bile salts in brush border membrane hydrolase turnover were investigated using metabolic labeling of brush border membrane hydrolase and immunoprecipitation in biliary diversion rats. After three days of biliary diversion, a significant increase in alkaline phosphatase activity was observed. Although synthesis of alkaline phosphatase in biliary diversion rats was similar to that observed in control rats, biliary diversion rats showed 1.5-fold slower turnover of alkaline phosphatase when compared with control rats. These results suggest that conjugated bile salts in the intestinal lumen may cause a rapid turnover of brush border membrane hydrolases, which may be increased by the enhanced enzyme degradation. The mechanisms for the enhanced degradation appeared to be solubilization of hydrolases caused by the detergent activity of bile salts. Therefore, conjugated bile salts may play an important physiological role in the regulation of expression of the protease-resistant enzymes such as alkaline phosphatase.

Alkaline Phosphatase↗

PubMed1995

Intrapleural perfusion hyperthermo-chemotherapy for malignant pleural dissemination and effusion.

Taking advantage of the antitumor effect of hyperthermia, we administered intrapleural perfusion hyperthermo-chemotherapy for the treatment of malignant pleural seeding or pleural effusion. This consists of irrigating the pleural space for 2 hours with 43 degrees C saline solution containing cis-platinum using specially devised extracorporeal circuits. From January 1988 through December 1993, we performed this technique in 12 patients with malignant disseminated lesions stemming from lung cancer who also underwent surgical resection of the primary lesions and in 7 patients with malignant pleural effusions who did not undergo thoracotomy or surgical resection. There were no serious clinical complications associated with this procedure. The pharmacokinetics showed that a high concentration of cis-platinum (more than 17.6 micrograms/mL in the free form) was retained in the pleural cavity during perfusion. After this therapy, the cancer cells showed marked degeneration with fibrosis in the pleural wall. The pleural effusion was well controlled in 100% of the patients. The median survival time in the 12 patients with pleural disseminated lesions who were treated with intrapleural perfusion hyperthermo-chemotherapy was 20 months. On the other hand, the median survival time in 7 patients with similar lesions who did not receive IPHC was only 6 months. Intrapleural perfusion hyperthermo-chemotherapy seems to have considerable value as an adjuvant therapy for patients with pleural dissemination who have had their primary lesions removed.

Adult↗

PubMed1995

Management of intraaortic balloon entrapment.

Two cases of intraaortic balloon entrapment were presented. In patient 1, urokinase was injected into the gas driver lumen of the intraaortic balloon catheter, then it could be removed. In patient 2, the intraaortic balloon was removed retrogradely through the left axillary artery. If the entrapped intraaortic balloon is encountered, it is effective to try a clot-lysis method initially, followed by a surgical approach through a left axillary artery.

Aged↗

PubMed1995

Clinical features of patients with anorexia nervosa: assessment of factors influencing the duration of in-patient treatment.

We investigated that factors affecting the duration of in-patient treatment of patients with anorexia nervosa by comparing pretreatment clinical features with the length of hospitalization in 55 patients. Only patients who had completed the entire course of treatment were included in our analysis. Longer hospitalization was correlated with: poor social adaptation; anxiety and/or personality disorders before onset; older age at onset; older age at admission to our hospital; lower minimum body weight after onset; lower body weight at admission; longer duration of illness; frequent previous hospital treatment and/or history of in-patient treatment for anorexia nervosa or other somatic disorders after onset; habitual stimulant (alcohol, coffee and/or cigarettes) abuse; and a history of stealing after onset. Step-wise regression analysis revealed that minimum body weight after onset and age at admission explained 47% of the variance in the duration of in-patient treatment. We also describe the nature of in patient treatment typically offered to patients with anorexia nervosa in Japan.

Adolescent↗

PubMed1995

Oxygen transport and hemodynamics during retrograde whole-body perfusion.

The changes in oxygen transport and hemodynamics during retrograde whole-body extracorporeal perfusion (retro-ECC) were studied in six mongrel dogs. Oxygen consumption during retro-ECC, in which the blood flow rate was set at 25% and 50% of the flow during antegrade extracorporeal perfusion (ante-ECC), respectively, was relatively high compared with that during ante-ECC. These changes were caused by an increase in the oxygen extraction ratio to 71.5% +/- 8.2% and 51.2% +/- 12.4% during retro-ECC/25% and retro-ECC/50%, respectively. Thus, tissue perfusion was apparently well maintained by retrograde perfusion on the basis of the oxygen transport data. However, central venous pressure increased markedly to 29.5 +/- 11.6 mmHg and 56.2 +/- 24.5 mmHg during retro-ECC/25% and retro-ECC/50%, respectively, because of massive venous congestion caused by insufficient arterial return of perfused blood. The great venous compliance and increased systemic vascular resistance were the main causes of circulatory failure during retro-ECC. The risk of serious complications owing to the venous congestion must be considered during retrograde perfusion, especially during the clinical application of retrograde cerebral perfusion.

Animals↗

PubMed1995

Dichotic listening in patients with partial section of the corpus callosum.

Patients with a complete section of the corpus callosum have been observed to exhibit strong left-ear suppression when different speech stimuli are presented to both ears simultaneously (so-called dichotic listening). Data concerning the locus of corpus callosum damage that causes strong left-ear suppression remains scanty. In the present investigation, a consonant-vowel syllable dichotic listening test was given to five right-handed patients with partial sections of the corpus callosum, which were located using MRI and accurately defined measurement procedures. The following two measurement methods were used: (i) the genu-splenium (G-S) method, in which a lesion was localized in the anteroposterior dimension relative to the total length of the corpus callosum, defined as the distance between the most anterior point of the genu to the most posterior point of the splenium; and (ii) the rostrum-splenium (R-S) method, which takes into account the curvature of the corpus callosum, and in which a lesion was localized relative to the total length of the corpus callosum, defined as the length of the curved line from the tip of the rostrum to the end of the splenium. Results were compared with scores from 50 normal control subjects. Strong left-ear suppression was observed in two patients, who had surgical sections of the posterior 15.5-18.5% of the corpus callosum as measured with the G-S method, or the posterior 20-24% of the corpus callosum as measured with the R-S method. The suppression phenomenon persisted for more than 10 years post-surgery. On the other hand, the remaining three patients, who had lesions anterior to the posterior 17-28% of the corpus callosum as measured with the G-S method or 20-33% as measured with the R-S method exhibited no left-ear extinction. Despite the common assumption that damage to the posterior part of the trunk of the corpus callosum causes strong left-ear suppression, the results from the G-S method indicated that damage to the splenium defined as the posterior one-fifth of the segment between the anterior-most and posterior-most points of the corpus callosum, cause strong left-ear suppression. By the R-S method, results showed that damage to the splenium (the posterior one-fifth of the curvature of the corpus callosum) and possibly the part extending to the most posterior part of the trunk (the posterior one-quarter of the curvature) causes strong left-ear suppression.

Adult↗

PubMed1995

Immunocytochemical detection of tumor necrosis factor-alpha in infiltrating tumor cells in the cerebrospinal fluid from five patients with leptomeningeal carcinomatosis.

We studied the immunoreactivity for tumor necrosis factor-alpha (TNF-alpha) in cerebrospinal fluid (CSF) cell smears from five patients with leptomeningeal carcinomatosis (LC). Immunostained TNF-alpha-positive tumor cells had brownish deposits in the cytoplasm, but no deposits were observed in the nucleus. The intensity of the TNF-alpha staining was greater in these tumor cells than in macrophages from patients with inflammatory diseases. Approximately 27-72% of the tumor cells were found to be TNF-alpha immunoreactive in all five samples from the patient with LC. These results suggest that the large amount of TNF-alpha produced by infiltrating tumor cells may play an important role in the development of the tumor.

Adenocarcinoma↗

PubMed1995

[Study of pathogenicity of various serovars of Enterococcus faecalis].

Using a mouse experimental UTI (urinary tract infection) model, a study was conducted to find the pathogenicity of various serovars of E. faecalis. On the basis of studies employing serovar-specific factor sera prepared with E. faecalis type strains, serovar 2, 3, 4 and 10 strains showed a high incidence of involvement in pyelonephritis: 90.3%, 85.7%, 85% and 73.3%. Serovar 1, 6 and 7 strains each showed a 63.6% incidence of involvement in pyelonephritis, indicating that they have a moderate pathogenicity. The pathogenicity of the other serovar strains was not very strong, with a low incidence of 40-59.1%. These results were thus in good agreement with the findings of the study using the mouse experimental UTI model infected with clinical isolates. Serotyping was performed of E. faecalis clinical isolates obtained from patients with pyelonephritis or urosepsis. Serovars 2 and 4 comprised 75.1% of these isolates. It was surmised that E. faecalis serovars 2 and 4 tend to have strong pathogenicity. Thus, there were quite a few differences in pathogenicity of E. faecalis according to each kind of serovar.

Animals↗

PubMed1995

[Study of distribution of serovars of Enterococcus faecalis clinical isolates].

Serotyping was conducted of E. faecalis strains isolated from various clinical specimens, and the distribution of the serovars was investigated. To date, 21 serovars of E. faecalis have been identified. The most common serovars in Japanese 770 strains were types 2 (30.6%), 7 (13.9%), 1 (12.2%) and 4 (6.9%), and these four serovars accounted for 63.6% of the total strains. The most common serovars in USA 200 strains were types 1 (22.5%), 4 (14.5%) and 2 (14.0%). The most common serovars in UK 65 strains were types 2 (24.6%), 4 (13.8%) and 9 (7.7%). The distribution of E. faecalis serovars differ as a function of the country of origin. Next, serological classification was performed for E. faecalis strains isolated from various Japanese clinical specimens. For the strains obtained from the urine, the most common serovars were types 2 (32.7%) and 7 (14.6%). Similarly, the most common serovars of the strains isolated from the various other clinical specimens were as follows: types 7 (35.0%) and 2 (15.0%) from pus; types 7 (44.4%) and 2 (33.3%) from sputum; types 2 (22.3%) and 1 (13.1%) from blood; and types 2 (34.9%) and 1 (27.9%) from the vaginal smear. It had no definite pattern for the distribution of serovars. The distribution of serovars varied in accordance with isolated years. Accordingly, the data obtained in these studies revealed that the distributions of E. faecalis serovars differ as a function of the geographical area of origin, the clinical specimen of origin and the year of origin. This approach is useful for serological classification of E. faecalis strains, and it is thought that it will be useful for epidemiological studies of this bacterium.

Enterococcus faecalis↗

PubMed1995

[A technique for removal of entrapped intra-aortic balloon catheter through the left axillary artery].

A case of intra-aortic balloon pumping (IABP) entrapment in which the ruptured catheter could be removed through the left axillary artery was reported. A 68-year-old man was admitted with persistent chest pain, and because of his poor cardiac condition, an IAB catheter was inserted by the Seldinger technique. During attempted extraction of the IAB catheter resistance was encountered and it turned out to be entrapped. Then a guide-wire was passed through the IAB lumen to the left axillary artery, the artery was exposed, and the tip of the guide-wire and IAB catheter were led to the arteriotomy site. After the balloon was dissected, the IAB catheter could be removed through the axillary artery. Finally, left femoro-left branchial artery bypass was performed with e-PTFE graft because of the arterial injury and ischemia of the involved arm. The patient recovered from this episode.

Aged↗

PubMed1995

In vivo angioscopic detection of the damaged endothelium on the atheromatous plaque: application with vital staining by methylene blue.

We attempted to detect the lesion of the damaged endothelium on the atherosclerotic plaque in vivo with dye and angioscope. The plaques were induced on the aortae of rabbits by the continuous mechanical injury with the insertion of the polyethylene tube and feeding with 2% cholesterol-added diet. We observed the some plaques could be stained with 5 x 10(-2) mol/L methylene blue by angioscope. Control aorta, without any stimulations on the aorta, could not be stained. One month after injury and cholesterol feeding the plaques were stained. In such plaques, the lack of the endothelium and the existence of the lipid-containing cell in the intima was observed. However, the plaques of the aorta 6 months after finishing these procedures could not be stained. In these plaques, the morphological characteristics known as the regression of the atheromatous plaque, ie, the regeneration of the endothelium, the thick collagen layer on the plaque and the massive calcification of the plaque were observed. The results obtained were as follows. (1) The atheromatous lesion with the damaged endothelium could be detected in vivo by our vital staining method. (2) The atheromatous plaques stained in vivo are the lesion with complication and enhanced permeability. (3) The slightly stained plaques indicate the lesions with regression and lost high permeability. (4) Our method would be able to add important information on the atheroscrelotic lesions in the clinical situations than that now we perform.

Angioscopy↗