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Biomedical subjects

M Ueda

Publications and source records attributed to M Ueda.

At least 379 records · Page 21Linked to original sources
PubMed1998

Effect of gelonin immunoconjugate with monoclonal antibody MSN-1 to endometrial adenocarcinoma on antigen-producing tumor cells in vivo.

Missile therapy, which destroys cancer cells specifically, has been advocated as an effective modality for the treatment of carcinoma. We have developed an immunoconjugate consisting of the monoclonal antibody MSN-1 (IgM), which reacts strongly with endometrial adenocarcinomas, combined with a plant hemitoxin named gelonin via a disulfide bond using N-succinimidyl-3-(2-pyridyldithio) propionate and 2-iminothiolane, and examined its selective cytotoxicity in athymic mice. The reductions in resected weights of target tumor cells, at the local site of MSN-1-gelonin immunoconjugate treatment, were 96% with local administration and 75% with caudal vein administration, as compared with the untreated group. There was no weight loss in treated mice. Our results suggest that this MSN-1-gelonin immunoconjugate has potential clinical applications in the treatment of endometrial adenocarcinomas.

Adenocarcinoma↗
PubMed1998

A study of sports-related mandibular angle fracture: relation to the position of the third molars.

Mandibular angle fractures have been considered attributable to the presence of unerupted third molars. We examined the relationship between the incidence of sports-related mandibular angle fractures and the presence of a mandibular third molar with emphasis on the position of the third molar. The incidence of angle fracture was significantly higher in the sports-related injury group than in the group with fracture due to other causes (P < 0.05). The incidence of angle fracture in the athletes with higher impaction scores was significantly higher than that in the subjects with higher scores who did not have sports-related fractures (P < 0.05). The percentage of rugby athletes with third molars was significantly higher than that of those without third molars (P < 0.001), and a high proportion of young athletes (89.5%) was considered to belong to a potential high-risk group for angle fractures. Our findings suggest that mandibular angle fractures are influenced by the presence and characteristics of the third molar in sports-related injuries.

Accidents, Traffic↗
PubMed1998

Oral injury and mouthguard usage by athletes in Japan.

The use of mouthguards in contact sports effectively prevents oral injury and preserves oral structures. We investigated oral injuries and awareness concerning mouthguards among Japanese high school soccer and rugby players. Athletes were asked a series of questions concerning their history of oral injury while participating in sports, and their pattern of mouthguard use was determined. The data were evaluated statistically using chi-square analysis. The incidence of oral injuries was 32.3% for soccer athletes and 56.5% for rugby athletes, with 0.8% and 24.1% of the respective groups having mouthguards. There were significant differences between the soccer and rugby groups (P < 0.001). Although 81.8% of soccer athletes thought mouthguards were unnecessary, only 26.2% of rugby athletes shared this opinion and there was a significant difference between the soccer and rugby groups. Many soccer athletes had insufficient knowledge about mouthguards and were not concerned about preventing oral injury, although it was in fact a common problem in their sport. Athletes as well as coaches must be made aware of the high risk of oral injury when playing soccer, rugby, and other contact sports.

Adolescent↗
PubMed1998

A new intermaxillary fixation method using adhesive cast splints for avoiding skin puncture.

Intermaxillary fixation using arch bars is performed for mandibular and maxillary fractures. They are applied to the respective maxillary and mandibular arches with circumdental stainless steel wires. Skin puncture may pose a risk for the surgeon. Therefore, the authors have developed and tested a method for using intermaxillary fixation using an adhesive cast splint. The resulting strength was found to be generally superior to that achieved with arch bars. Despite some problems, this technique is considered a useful method for avoiding skin puncture.

Adhesives↗
PubMed1998

[Evaluation of pyuria by means of urinary sediment method--a comparison to the counting chamber method].

We compared the urinary sediment method to counting chamber method in evaluating pyuria, in order to elucidate an issue of urinary sediment method. The KOVA system was used for counting chamber method. Three hundred and ten urine specimens from the patients who visited Fuji City Central Hospital in March, 1995, were employed. The numbers of leukocytes of each specimen was counted by means of urinary sediment method and counting chamber method, and compared. The urinary leukocyte count evaluating by means of these two methods were correlated well. However, the discrepancy of urinary leukocyte counts by means of these two methods were recognized in two specimens. In these two specimens, the leukocyte count was 1 to 4/5HPF by means of urinary sediment method, but more than 50/microliter by means of counting chamber methods. Significant bacteria (10(4) cfu/ml or more), positive esterse reaction, and high pH (8.5) were recognized in both specimens. In addition, one of two these specimens was hypotonic (specific gravity was 1.008). Therefore, it was suggested that leukocytes were sometimes disrupted with centrifugation. These results indicate that counting chamber method is more useful urinary sediment method to detect pyuria.

Adolescent↗
PubMed1998

[Correlation in Staphylococcus aureus infections between toxic shock syndrome toxin-1 production and clinical feature].

Toxic shock syndrome (TSS) is caussed by toxic shock syndrome toxin-1 (TSST-1) of Staphylococcus aureus. We studied the incidence of TSST-1 production by the clinical isolates of S. aureus, in order to clarify the possibility of TSS caused by S. aureus. One hundred and seventeen clinical isolates of S. aureus were tested. Of 117 strains, 74 were methicillin-cephem resistant S. aureus (MRSA), and 43 were methicillin-cephem sensitive S. aureus (MSSA). TSST-1 production and penicillinase (PCase) activity were measured by means of reversed passive Latex aggulutination method and acidmetric assay, respectively. The incidences of TSST-1 production by PCase positive MRSA, PCase negative MRSA, PCase positive MSSA and PCase negative MSSA were 92% (55/60), 78% (11/14), 21% (7/33) and 0% (0/10), respectively. TSS occurred in a patient with chronic complicated pyelonephritis after endopyelotomy for hydronephrosis. In this patient, PCase positive MRSA which produced TSST-1 was isolated from urinary tract, and he was cured after administration of arbekacin. These results indicsate that methicillin-cephem resistance and PCase production are the risk factors for TSST-1 production in S. aureus.

Bacterial Toxins↗
PubMed1998

Assimilation of cellooligosaccharides by a cell surface-engineered yeast expressing beta-glucosidase and carboxymethylcellulase from aspergillus aculeatus

Since Saccharomyces cerevisiae lacks the cellulase complexes that hydrolyze cellulosic materials, which are abundant in the world, two types of hydrolytic enzymes involved in the degradation of cellulosic materials to glucose were genetically co-immobilized on its cell surface for direct utilization of cellulosic materials, one of the final goals of our studies. The genes encoding FI-carboxymethylcellulase (CMCase) and beta-glucosidase from the fungus Aspergillus aculeatus were individually fused with the gene encoding the C-terminal half (320 amino acid residues from the C terminus) of yeast alpha-agglutinin and introduced into S. cerevisiae. The delivery of CMCase and beta-glucosidase to the cell surface was carried out by the secretion signal sequence of the native signal sequence of CMCase and by the secretion signal sequence of glucoamylase from Rhizopus oryzae for beta-glucosidase, respectively. The genes were expressed by the glyceraldehyde-3-phosphate dehydrogenase promoter from S. cerevisiae. The CMCase and beta-glucosidase activities were detected in the cell pellet fraction, not in the culture supernatant. The display of CMCase and beta-glucosidase proteins on the cell surface was confirmed by immunofluorescence microscopy. The cells displaying these cellulases could grow on cellobiose or water-soluble cellooligosaccharides as the sole carbon source. The degradation and assimilation of cellooligosaccharides were confirmed by thin-layer chromatography. This result showed that the cell surface-engineered yeast with these enzymes can be endowed with the ability to assimilate cellooligosaccharides. This is the first step in the assimilation of cellulosic materials by S. cerevisiae expressing heterologous cellulase genes.

Journal Article↗
PubMed1998

Cytotoxic T-lymphocyte-mediated lysis of Toxoplasma gondii-infected target cells does not lead to death of intracellular parasites.

CD8(+) T cells play a crucial role in the control of infection with intracellular microbes. The mechanisms underlying the CD8(+) T-cell-mediated clearance of the intracellular pathogen Toxoplasma gondii are, however, not completely understood. The effect of CD8(+) cytotoxic T-lymphocyte (CTL)-mediated lysis of host cells on the viability of intracellular T. gondii was investigated. Quantitative competitive PCR of the gene encoding T. gondii major surface antigen (SAG-1) was combined with treatment of the parasites with DNase, which removed the DNA template of nonviable parasites. The induction by CD8(+) CTLs of apoptosis in cells infected with T. gondii did not result in the reduction of live parasites, indicating that intracellular T. gondii remains alive after lysis of host cells by CTLs.

Animals↗
PubMed1998

Genetic evaluation of physiological functions of thiolase isoenzymes in the n-alkalane-assimilating yeast Candida tropicalis.

The n-alkane-assimilating diploid yeast Candida tropicalis possesses three thiolase isozymes encoded by two pairs of alleles: cytosolic and peroxisomal acetoacetyl-coenzyme A (CoA) thiolases, encoded by CT-T1A and CT-T1B, and peroxisomal 3-ketoacyl-CoA thiolase, encoded by CT-T3A and CT-T3B. The physiological functions of these thiolases have been examined by gene disruption. The homozygous ct-t1a delta/t1bdelta null mutation abolished the activity of acetoacetyl-CoA thiolase and resulted in mevalonate auxotrophy. The homozygous ct-t3a delta/t3b delta null mutation abolished the activity of 3-ketoacyl-CoA thiolase and resulted in growth deficiency on n-alkanes (C10 to C13). All thiolase activities in this yeast disappeared with the ct-t1a delta/t1bdelta and ct-t3a delta/t3bdelta null mutations. To further clarify the function of peroxisomal acetoacetyl-CoA thiolases, the site-directed mutation leading acetoacetyl-CoA thiolase without a putative C-terminal peroxisomal targeting signal was introduced on the CT-T1A locus in the ct-t1bdelta null mutant. The truncated acetoacetyl-CoA thiolase was solely present in cytoplasm, and the absence of acetoacetyl-CoA thiolase in peroxisomes had no effect on growth on all carbon sources employed. Growth on butyrate was not affected by a lack of peroxisomal acetoacetyl-CoA thiolase, while a retardation of growth by a lack of peroxisomal 3-ketoacyl-CoA thiolase was observed. A defect of both peroxisomal isozymes completely inhibited growth on butyrate. These results demonstrated that cytosolic acetoacetyl-CoA thiolase was indispensable for the mevalonate pathway and that both peroxisomal acetoacetyl-CoA thiolase and 3-ketoacyl-CoA thiolase could participate in peroxisomal beta-oxidation. In addition to its essential contribution to the beta-oxidation of longer-chain fatty acids, 3-ketoacyl-CoA thiolase contributed greatly even to the beta-oxidation of a C4 substrate butyrate.

Acetyl-CoA C-Acetyltransferase↗
PubMed1998

Application of subtype-specific monoclonal antibodies for rapid detection and identification of influenza A and B viruses.

We established a rapid method for the identification of influenza A and B virus strains: the peroxidase-antiperoxidase (PAP) staining method with two subtype-specific murine monoclonal antibodies, C179 (H1 and H2 specific) and F49 (H3 specific), and an anti-influenza B virus rabbit polyclonal serum. The types and subtypes of 160 strains were examined, and 158 strains were identified to be the same by the hemagglutination-inhibition (HI) test and the PAP method. In contrast to the results by the HI test, two strains were revealed to be a mixture of two subtypes (H1 and H3) by the PAP method, which was confirmed by plaque cloning. We further analyzed clinical specimens by the PAP method by directly inoculating specimens into Madin-Darby canine kidney cells in microplates. After 40 h of incubation, the types and subtypes of viruses in 52 of 152 specimens were clearly identified. Since the reactivities of the two monoclonal antibodies are not influenced by the antigenic drift of influenza virus, the newly developed method should be applicable not only for rapid diagnosis but also for the epidemiological study of influenza.

Animals↗
PubMed1998

Physiological roles of integrin alpha 6 beta 1 in ovarian functions.

We previously reported that human ovarian cells express integrin beta 1 families. The physiological role(s) of integrins was investigated using in vitro human granulosa cell culture and in vivo mouse ovulation model. In human luteinizing granulosa cell culture obtained from the patients undergoing in vitro fertilization treatment, laminin, which is a ligand for integrin alpha 6 beta 1, suppressed the production of progesterone by granulosa cells. On the other hand, the anti-alpha 6 monoclonal antibody (mAb) GoH3, which partially inhibits the interaction between integrin alpha 6 beta 1 and laminin, enhanced production of progesterone by 2-fold of the control under the culture with laminin, indicating that integrin alpha 6 beta 1 regulates the luteinization of human granulosa cell during the periovulatory phase. In an immature superovulated 13-day-old ICR (CD-1) mice model, intraperitoneal administration of GoH3 induced successful ovulation, whereas no ovulation was observed in the GoH3-nontreated groups, showing that integrin alpha 6 beta 1 is related to gonadotropin-induced follicular growth. These findings suggest that the interaction between integrin alpha 6 beta 1 and laminin plays an important role in the corpus luteum formation and follicular growth.

Animals↗
PubMed1998

Induction of cytokines by a phenylpropanoid glycoside acteoside.

A phenylpropanoid glycoside acteoside was found to induce interleukin (IL)-1, IL-6, and tumor necrosis factor-alpha (TNF-alpha) in macrophage-like cell line J774.A1 at 1-100 ng/ml. In addition, when the stimulatory action of acteoside was studied using the bovine glomerular endothelial cell line GEN-T, it stimulated IL-6 production. These stimulatory activities were not abolished by treatment with polymixin B, which inactivates lipopolysaccharide (LPS), indicating that the action was not a contamination of LPS.

Animals↗
PubMed1998

Virtualized angioscopy of the thoracic aorta in a rabbit model of atherosclerosis.

The purpose of this study was to apply virtual reality technology to spiral computed tomographic (CT) angiogram images in a rabbit model of atherosclerosis and to correlate the images with histopathologic evaluation of the aorta. Image data were transferred to the virtual endoscope system in a graphics workstation. "Virtualized angioscopy" includes an interactive graphic user interface, which controls the viewpoint, the direction of the observation, and rendering and navigation functions. The virtual angioscopy system demonstrated irregularities of the luminal surface of the ascending aorta and a smooth luminal surface in the descending aorta. These observations were correlated with histopathologic findings. The results of this study indicate that the potential and real benefits of virtualized angioscopy far outweigh several technical limitations.

Angioscopy↗
PubMed1998

Effect of the combination of a local OK-432 injection and hyperthermia on SCC VII tumors in mice.

Hyperthermia is being investigated as a cancer treatment. Many of its basic mechanisms, particularly those related to cell killing, are still poorly understood. We used a transplanted squamous cell carcinoma cell line to investigate the therapeutic effect of hyperthermia. In particular, we examined the effect of OK-432 (biological response modifier) on hyperthermia-induced apoptosis. In the hyperthermia only group the most extensive necrosis occurred on day 3 (70.3%), and the apoptosis index also was highest on that day (69.3). These results suggest that the induction of apoptosis is closely related to the cell death caused by hyperthermia. The percent of necrosis was significantly higher in the groups given hyperthermia and combined OK-432 and hyperthermia treatment than in the OK-432 group (p < 0.05). The apoptosis index was significantly lower in the combined OK-432 and hyperthermia treatment group than in the hyperthermia only group, indicative that the antitumor effect of combined hyperthermia and OK-432 therapy is not ascribable to the induction of apoptosis.

Animals↗
PubMed1998

L-type calcium channels in vascular smooth muscle cells from spontaneously hypertensive rats: effects of calcium agonist and antagonist.

Studies using the whole-cell voltage-clamp technique have demonstrated that L-type Ca2+ channel activity is increased in vascular smooth muscle cells from spontaneously hypertensive rats (SHR). We recorded L-type Ca2+ channel currents in cultured mesenteric artery smooth muscle cells from SHR and Wistar Kyoto (WKY) rats by using the cell-attached patch-clamp technique. Depolarizing voltage steps from a holding potential of -40 mV elicited voltage-dependent inward Ba2+ currents. There was no difference in the L-type Ca2+ channel I-V curve or in the open probability between SHR and WKY. The inward currents were inhibited by the Ca2+ antagonists nifedipine and verapamil, but were enhanced by the Ca2+ agonist Bay K 8644 in a concentration-dependent manner. The Bay K 8644-induced increase and the nifedipine-induced inhibition of the inward currents were enhanced in SHR, whereas there was no difference in the verapamil-induced inhibition of the currents between the two strains of rats. These results suggest that the enhanced L-type Ca2+ channel activity observed in vascular smooth muscle cells from SHR is not due to altered function of a single L-type Ca2+ channel. It appears that the sensitivity of dihydropyridine receptors in the channels is enhanced in SHR.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗
PubMed1998

Use of new magnetic attachments for implant-supported overdentures.

A newly designed magnetic attachment system for external hexed implants with a standard abutment platform has been developed. This system has certain definite advantages over bar attachments and ball attachments, which are frequently utilized for implant-supported overdentures. Especially, it can be applied to cases with reduced vertical dimension of occlusion because the total height of the magnet and the keeper is only 2.3 mm when assembled. In addition, detrimental lateral stresses to the fixture are greatly alleviated due to very low attractive forces horizontally. Favorable clinical results using this new magnetic attachment system have been obtained, and it may be considered a useful addition to overdenture therapy using any external hexel implant with a standard abutment platform, such as the Brånemark implant system.

Aged↗
PubMed1998

Intracranial pressure monitoring using a newly developed transducer-tipped ventricular drainage catheter.

A transducer-tipped ventricular drainage catheter (TVDC) was developed to allow continuous measurement of intracranial pressure (i.c.p.) without interrupting cerebrospinal fluid (CSF) drainage. The 8.5 Fr catheter with a double lumen has 16 side holes for CSF drainage and a small silicone strain-gauge transducer on the side of the catheter tip to measure the ICP directly. The transducer is composed of a 2 x 1 mm2 silicone plate. Calibration must be performed before insertion. The calibrated catheter is inserted into the ventricles, usually via the anterior horn of the lateral ventricles to the foramen of Monro. Recalibration is not necessary even if the patient's head is tilted. The TVDC was applied to patients in whom ICP was suspected to be high and in whom the ventricles were large enough for tapping. The ICP wave form and values measured by the TVDC and the manometer method were equivalent. The drift phenomenon did not occur throughout the entire measurement period. The TVDC is very useful for both controlling and monitoring ICP.

Catheterization↗