Search PubMed⌕ Search

Biomedical subjects

K Ouchi

Publications and source records attributed to K Ouchi.

At least 37 records · Page 2Linked to original sources
PubMed1998

The effects of retraction forces applied to the anterior segment of orthodontic arch wires: differences in wire deflection with wire size.

Orthodontic arch wire deflection was studied in relationship to retraction forces applied to arch wires during anterior retraction with sliding mechanics. Two different sizes of orthodontic stainless steel arch wires (SS wires) .016" x .022" and .019" x .025", were examined. Retraction forces were generated using an elastic polymer material to measure arch wire deflection and applied to the arch wires by a commonly-used anterior retraction device with power chains hooked from the first molar areas to the pre-welded posts at distal site of the lateral incisors. The force application caused both the .016" x .022" and the .019" x .025" arch wires to deflect. The amount of deflection increased almost in proportion to the retraction force applied. With the same retraction force applied, the amount of deflection of the .019" x .025" wire was approximately 47.1% of that of the .016" x .022" wire.

Dental Arch↗
PubMed1997

Interstitial deletion of 6q21-q23 associated with split hand.

We report on a 7-month-old boy with interstitial deletion of 6q21-q23 and split-hand defect. He died at 7 months. This is the fifth patient with distal limb anomaly associated with a rearrangement of 6q21 region, and supports previous suggestions that there may be candidate gene(s) for distal limb development in the 6q21 region.

Chromosome Deletion↗
PubMed1996

Histologic features and clinical significance of venous invasion in colorectal carcinoma with hepatic metastasis.

BACKGROUND: In colorectal carcinoma, venous invasion has been related to patient survival. Liver metastasis develops more frequently when venous invasion is present. However, the histologic features and clinical significance of venous invasion are not well understood. METHODS: A histologic study of venous invasion in colorectal carcinoma was performed on 19 patients with synchronous hepatic metastasis (Group A), 16 patients with metacaronous hepatic metastasis (Group B), and 26 patients with Dukes Stage C tumors who survived for 5 years without recurrence (Group C). The histologic features of venous invasion were classified into three types: tumor cells that were distant from the vein walls were categorized as floating type, those filling the lumen of a vein as filling type, and those surrounded by a vein obliterated with inflammatory reaction as occlusive type. RESULTS: Venous invasion was present in 89.5% of Group A patients and 75% of Group B patients, which was significantly higher than the 15.4% observed in Group C patients (P < 0.001). A slight to extensive degree of venous invasion was found in Groups A and B, but no extensive venous invasion was found in Group C. All patients in Groups A and B (except one patient) had floating, filling, or a combination of floating and filling types of venous invasion, whereas all patients in Group C had the occlusive type of venous invasion. A majority of the patients in all three groups showed invasion of extramural veins. CONCLUSIONS: There is a close relationship between venous invasion and the development of liver metastasis in patients with colorectal carcinoma. Patients with no sign of metastasis had a lower incidence and lower extent of venous invasion, and inflammatory damage to the vein walls around the intravenous tumor appeared to reduce the likelihood of distant metastasis.

Adult↗
PubMed1996

Effects of urinastatin and free radical scavengers on hepatic lipid peroxidation in endotoxemia.

In gram-negative septicemia, endotoxin-induced free radicals probably damage the liver cells by membrane lipid peroxidation. Phosphotidylcholine hydroperoxide (PCOOH), a primary lipid peroxidation product can be applied as a parameter to measure the extent of liver damage. The protective effects of urinastatin and free radical scavengers, superoxide dismutase (SOD), and catalase against hepatic lipid peroxidation and tissue energy reserves in the liver during endotoxemia were evaluated in rats with gram-negative septicemia induced by cecal ligation and puncture (CLP). One hundred and sixty-five rats were divided into three groups. The first two groups consisted of 45 rats each. Group (1) was used for blood endotoxin level and liver function tests, group (2) for hepatic energy charge and PCOOH measurement, and group (3) (n = 75) for survival study. In each group, control animals received saline injection only. Urinastatin was injected twice intravenously through tail veins using 50,000 u/kg at 0 and 12 hr after CLP. SOD 90,000 u/kg and catalase 50,000 u/kg were given subcutaneously just before CLP and every 3 hr thereafter up to 24 hr. Liver and blood specimens were taken at time points 0, 12, and 24 hr after CLP. Increased concentration of PCOOH in liver denotes that endotoxemia can damage the liver by hepatocellular lipid peroxidation. Attenuation of lipid peroxidation, which correlated with liver enzyme leakage, was noted by finding significant decreased concentrations of PCOOH (P < 0.001), improvement in energy charge (P < 0.05), and survivability (P < 0.05) was seen in urinastatin or radical scavenger-treated groups. These results suggested that urinastatin has protective effect against free radical-induced lipid peroxidation probably by inhibiting proteases especially elastase, from polymorphonuclear leucocytes. SOD and catalase, which scavenged oxygen free radicals, also suppressed free radical-induced lipid peroxidation. Improvement in survivability was also seen in treated groups.

Animals↗
PubMed1996

[Assay of specific anti-Chlamydia pneumoniae antibodies by ELISA method. 2. studies on clinical usefulness and serological diagnostic standards].

We measured anti-Chlamydia pneumoniae (C. pneumoniae) specific antibody titers by means of a newly-developed enzyme-linked immunosorbent assay (ELISA) method using an anti-C. pneumoniae specific antibody detection reagent. The clinical usefulness of this method was hereby evaluated. The IgG, IgA and IgM titers in 418 serum specimens obtained from patients with respiratory tract infections were measured by this new ELISA method, and the results were compared with the titers determined for the same specimens with the micro immunofluorescence (Micro-IF) method. The results showed good correlation coefficients for IgG, IgA and IgM. The two assay methods showed high agreement rates for positivity and for negativity. Specimens which did not yield the same results with the ELISA method and the Micro-IF method were subjected to analysis by the Western blot method, and the rates of agreement with the ELISA results were high. In addition, the child (0 approximately 15 yrs old; n = 122) and adult (16 approximately 90 yrs old; n = 133) cases were classified on the basis of being antigen-positive or antigen-negative at the initial examination, and their antibody-positive rates were determined. The adults showed no statistically significant differences in the antibody-positive rates for either IgG or IgA antibodies as a function of the pretreatment antigen status. However, the children showed statistically significant (p < 0.001) differences in the antibody-positive rates for both IgG and IgA antibodies as a function of the antigen status in the antigen-positive group compared with the rates in the antigen-negative group. Furthermore, the IgM-positive rates for the children were high in the antigen-positive group compared with the rates in the antigen-negative group, and the difference was statistically significant (p < 0.001). The IgM-positive rates in the adults were also significantly (p < 0.05) different between the antigen-positive group and the antigen-negative group. The Micro-IF method was applied to 34 specimens from antigen-positive patients, and 22 specimens were found to show an IgG titer of > or = 512 or an IgM titer of > or = 16. The diagnoses of these patients were acute respiratory disease in sixteen, pneumonia in four. Application of the ELISA-method to those 22 specimens showed all of them to exhibit IgG absorbance of > or = 0.6 and IgA absorbance of 0.2. The results described above indicate the clinical usefulness of our new ELISA method for the detection of antibodies specific for C. pneumoniae. The significance of this ELISA method for serological diagnosis of C. pneumoniae infections and the criteria for diagnosis of acute infections were also discussed.

Adolescent↗
PubMed1995

Investigation of nosocomial respiratory infection due to Pseudomonas cepacia by arbitrarily primed polymerase chain reaction.

We used DNA fingerprinting by the arbitrarily primed polymerase chain reaction (AP-PCR) technique for an epidemiologic investigation of Pseudomonas cepacia nosocomial isolates obtained from patients attending our hospital. This approach was compared with conventional phenotypic typing and pulsed-field gel electrophoresis (PFGE). The patterns of gel electrophoresis of the products of AP-PCR differed significantly according to differences in the concentration of Mg2+ and in pH. AP-PCR and PFGE was identical in their resolving power, as the two methods generated four different profiles and identified the same group of strains. The AP-PCR method constitutes an easy alternative to the well-established PFGE method.

Adolescent↗
PubMed1995

Isolation of a cold-sensitive fermentation mutant of a baker's yeast strain and its use in a refrigerated dough process.

Conventional baker's yeast converts sugars in dough into CO2 and ethanol to a significant extent when the dough is stored for days at 5 degrees C. We have isolated Csf (cold-sensitive fermentation) mutants of a commercial baker's yeast by a selection method including as the critical step a nystatin treatment to mutagenized cells at 10 degrees C in the presence of antimycin A. The fermentative activity of mutant strain CSF3 was substantially zero at 5 degrees C and one-fifth that of the parent at 10 degrees C but was restored to the same level as the parental activity at 25 to 40 degrees C. In contrast with the parent, the mutant strain normally produced white bread dough and butter roll dough even after the dough was stored for a week at 5 degrees C.

Antimycin A↗
PubMed1995

Analysis of strains of Burkholderia (Pseudomonas) cepacia isolated in a nosocomial outbreak by biochemical and genomic typing.

We analyzed strains of Burkholderia (formerly Pseudomonas) cepacia isolated in a nosocomial outbreak by biochemical and genomic typing methods. One hundred isolates of B. cepacia were obtained from patients at several wards in a single hospital from March 1983 to February 1984. These isolates were classified into 12 groups by a new biochemical typing scheme on the basis of the production of six enzymes and the production of hemolytic substance and yellow pigment. Among them, 33 strains collected from the 12 groups were further characterized by DNA fingerprinting by pulse-field gel electrophoresis, ribotyping, and plasmid profile analysis. Forty-seven strains of B. cepacia of independent origins and 25 isolates from the same hospital obtained 10 years later for a follow-up study were also subjected to analysis. Both DNA fingerprinting and ribotyping clearly discriminated the isolates from different hospitals. Of interest, although the biochemical typing and plasmid profiles of the isolates obtained during 1983 to 1984 in a single hospital were variable, genomic typing identified the majority of the isolates (32 of 33 [97%]) as derivatives of a single strain. Furthermore, a follow-up study suggested the persistence of such derivatives among the isolates after a decade. These results clearly indicated that the outbreak of B. cepacia infection in the hospital was nosocomial in origin. Thus, the usefulness of genomic typing for epidemiological studies of B. cepacia infection was further demonstrated. The biochemical typing revealed the marked variability of phenotypes of B. cepacia.

Bacterial Typing Techniques↗
PubMed1995

Existence of gamma-aminobutyric acid and its biosynthetic and metabolic enzymes in rat salivary glands.

To obtain more insight into the physiological role of gamma-aminobutyric acid (GABA) in rat salivary glands, we measured the concentration of GABA and the activities of its biosynthetic and metabolic enzymes, glutamate decarboxylase (GAD) and GABA transaminase (GABA-T). The GABA concentrations in rat parotid and submandibular glands were 10.0 and 14.3 nmol/g weight, respectively, which were 0.6-0.8% of the levels in the brain (cerebellum and medulla oblongata), whereas glutamic acid (Glu) was abundant in the two glands. These GABA levels in the two glands were significantly decreased by administration of semicarbazide (200 mg/kg, i.p.), a GAD inhibitor, and increased by gabaculine (50 mg/kg, i.p.), a GABA-T inhibitor. The activities of both GAD and GABA-T were also detected in homogenates of the two salivary glands, but they were lower than those in the brain. However, kinetic analysis showed that the values of Michaelis constants for Glu and GABA in both enzyme reactions in these two glands were similar to those in the brain. These results indicate that GABA and its biosynthetic and metabolic enzymes are present in rat salivary glands as well as the brain.

4-Aminobutyrate Transaminase↗
PubMed1995

Chromosome bisection in the yeast Saccharomyces cerevisiae facilitated by yeast artificial chromosomes bearing a site-specific recombination system.

A chromosome bisection method was constructed using yeast artificial chromosomes (YAC) and a GAL1-promoted site-specific recombination system. This method was applied to bisect chromosome IV into the left and right parts of the centromere region. The bisection occurred at frequencies of about 10% when the recombination site DNAs were integrated onto YAC and chromosome IV in the same direction, but were less than 10(-3) when they were in opposite directions. Reconstruction of the original chromosome IV from the bisected chromosomes was also induced by galactose at high frequencies. Loss of the left part chromosome was found at the frequencies of 0.9 x 10(-3) after hybrid cells between the chromosome-bisected strain and a normal haploid were subcultivated in a complete medium. The bisection and reconstruction of chromosome IV and deletion of the left part chromosome were demonstrated by electrophoretical karyotyping.

Chromosome Deletion↗
PubMed1994

Survival after surgery for cancer of the gallbladder.

The records of 45 patients with carcinoma of the gallbladder who had undergone surgical resection at least 5 years previously were reviewed retrospectively to determine which factors influence long-term survival. Seventeen patients survived at least 5 years and 23 died from recurrence (five patients were excluded from analysis). Of the 17 long-term survivors 15 had tumours superficial to the subserosa that showed a non-infiltrative growth pattern. Those alive at 5 years were more likely than short-term survivors to have tumours that were papillary (P < 0.05) or well differentiated (P < 0.01) adenocarcinoma. Venous, lymphatic and perineural invasion was more common in short- than in long-term survivors (87 versus 29 per cent, P < 0.001). Patients with tumours limited to the muscularis and those with non-infiltrative subserosal involvement are likely to have better survival and may have a chance of cure after extended cholecystectomy.

Adenocarcinoma↗
PubMed1994

Prevalence of Chlamydia pneumoniae in acute lower respiratory infection in the pediatric population in Japan.

Chlamydia pneumoniae has been established as an important etiologic agent of acute respiratory tract infection in humans, especially in adults. However, there is little information available on C. pneumoniae infection in the pediatric age group. The microimmunofluorescence test and Chlamydia pneumoniae-specific polymerase chain reaction (PCR) method were applied to reveal the role of C. pneumoniae as an etiologic agent of acute lower respiratory tract infection in children in Japan. Among 136 patients aged between 2 months and 15 years with acute lower respiratory tract infection, five patients with pneumonia were found to have recent C. pneumoniae infection by the microimmunofluorescence test. C. pneumoniae-specific PCR products were detected from specimens of four patients among these five. Neither C. trachomatis nor C. psittaci infection was found in this population. These results suggest that C. pneumoniae is an important causative agent of acute childhood pneumonia and may be the most prevalent pathogen among the genus Chlamydia that causes acute lower respiratory disease in this age group in Japan.

Acute Disease↗
PubMed1994

Construction from a single parent of baker's yeast strains with high freeze tolerance and fermentative activity in both lean and sweet doughs.

From a freeze-tolerant baker's yeast (Saccharomyces cerevisiae), 2,333 spore clones were obtained. To improve the leavening ability in lean dough of the parent strain, we selected 555 of the high-maltose-fermentative spore clones by using a method in which a soft agar solution containing maltose and bromocresol purple was overlaid on yeast colonies. By measuring the gassing power in the dough, we selected 66 spore clones with a good leavening ability in lean dough and a total of 694 hybrids were constructed by crossing them. Among these hybrids, we obtained 50 novel freeze-tolerant strains with good leavening ability in all lean, regular, and sweet doughs comparable to that of commercial baker's yeast. Hybrids with improved leavening ability or freeze tolerance compared with the parent yeast and commercial baker's yeasts were also obtained. These results suggest that hybridization between spore clones derived from a single parent strain is effective for improving the properties of baker's yeasts.

Fermentation↗
PubMed1994

Perineural tumor invasion and its relation with the lymphogenous spread in human and experimental carcinoma of bile duct. A computer-aided 3-D reconstruction study.

The pathogenesis of perineural tumor invasion was studied by computer aided 3-D reconstruction of bile duct wall from two patients submitted to surgery for hepatohilar carcinoma, in order to analyze how and via what route carcinoma reaches the perineural spaces. Rabbits with VX2 carcinoma implanted in the wall of the common bile duct were also examined. It was found that carcinomas growing along the perineural spaces had abundant connections with the tumors growing outside the nerve, especially those lurking in the lymphatics. In an additional analysis on the wall tissues of bile duct from 35 patients operated for carcinoma, the degree of invasion into perineural spaces proved to correlate with that into lymphatics much higher than with venular invasion. Thus it is likely that tumors reach distant nerves mainly via lymphatics, i.e., forming satellite lymphogenous foci around nerves and then, as a second step, breaking into the perineural spaces.

Adenocarcinoma↗
PubMed1994

Bismuth-free triple therapy for eradicating Helicobacter pylori and reducing the gastric ulcer recurrence rate.

OBJECTIVES: The goals of this study were to assess the effectiveness of a new triple therapy consisting of amoxicillin and metronidazole with plaunotol in the eradication of Helicobacter pylori infection in humans, and to determine whether this treatment regimen reduces the rate of recurrence of gastric ulcer in patients infected with H. pylori, without instituting maintenance therapy with H2-receptor antagonists. METHODS: Thirty patients with active gastric ulcer who were infected with H. pylori were first treated with omeprazole until scarring occurred. Patients then received plaunotol for 4 wk, with amoxicillin and metronidazole for 7 days. RESULTS: This triple therapy resulted in the safe eradication of H. pylori in 26 (86.7%) of 30 patients, with no recurrence of ulcer seen during a 12-month follow-up period in patients who tested negative for the presence of H. pylori. In addition, histological inflammatory changes improved in these patients. Of the four patients with persistent H. pylori infection, in three (75%), ulcers recurred. CONCLUSION: This new triple therapy was very effective in eradicating H. pylori in infected patients and in reducing the rate of recurrence of gastric ulcer in these patients.

Amoxicillin↗
PubMed1994

The radiologic presentation of Osler-Weber-Rendu disease of the liver.

A case of Osler-Weber-Rendu disease with extensive hepatic arteriovenous fistulation is described in detail. Hemodynamic and imaging data indicated hepatic artery to hepatic vein shunting. Enhanced magnetic resonance imaging demonstrated the existence of arteriovenous fistulas by virtue of simultaneous enhancement of hepatic arteries and veins. Embolization treatment was not indicated because the patient was asymptomatic despite cardiac high output.

Arteriovenous Fistula↗