Biomedical subjects

Y Kudoh

Publications and source records attributed to Y Kudoh.

At least 55 records · Page 3Linked to original sources

PubMed1995

[Species and serovar-distribution, and drug-resistance of Shigella strains isolated from imported and domestic cases from 1990 through 1994 in Tokyo].

A total of 446 Shigella strains consisting of 336 imported and 110 domestic strains isolated in Tokyo from 1990 to 1994 were examined for their species and serovar-distribution, and their drug-resistance. In both imported and domestic strains, S. sonnei was found to be the most prevalent species, followed by S. flexneri. In imported strains, however, the isolation frequency of S. flexneri, S. boydii and S. dysenteriae were higher than that of domestic strains, and the serovar of each species was distributed in a wider range than that of the domestic strains. Provisional new serovar Shigella strains were isolated from 8 imported cases and 2 domestic cases. The drug-resistance-test using 9 drugs (CP, TC, SM, KM, ABPC, ST, NA, FOM, and NFLX) showed that 82.7% of the imported strains and 89.1% of the domestic strains were resistant to any drugs examined. Drugs of a high resistant rate were SM, TC, ST for the both groups. Drug-resistance-patterns of the resistant isolates varied to 21 types. Among those, a triple drug-resistance-type with TC SM ST was found the most frequently in both groups. None of the strains were resistant to FOM or NFLX.

Anti-Bacterial Agents↗

PubMed1995

[Regarding the Shigella flexneri 4 strains isolated in recent years].

A total of 38 strains of Shigella flexneri 4, 14 of which were subserotype 4a but 24 of which were of an undecided subserotype, isolated in recent years, were studied for their biochemical and serological characteristics, and drug susceptibility. Among the biochemical characteristics examined, 21 of the 38 strains (55.3%) were mannitol negative biotype and utilized sodium acetate, meanwhile, 17 of the mannitol positive strains did not utilize sodium acetate. The results of serological tests showed that 22 of the 24 strains, were of an undecided subserotype, basically subserotype 4a. Drug susceptibility was tested for nine drugs (CP, TC, SM, KM, ABPC, ST, NA, FOM and NFLX). Fifteen of the 17 mannitol positive strains (88.2%) and 12 of the 21 mannitol negative ones (57.1%), were found to be resistant to the 5 drugs, such as CP, TC, SM, ABPC or ST. None of the strains were resistant to KM, NA, FOM or NFLX.

Anti-Bacterial Agents↗

PubMed1995

[Studies on maternal transmission of HIV-1].

To investigate HIV-1 transmission from mother to child, samples taken from 3 HIV-1 sero-positive pregnant mothers, 3 children born by caesareans from their mothers and therapeutic abortion from 2 HIV-1 sero-positive mothers were tested for HIV-1 antibody by westernblot, p24 antigen by antigen captured ELISA, proviral DNA by Nested-PCR and isolation of HIV-1 virus from peripheral blood, cord blood, amniotic fluid and placenta. HIV-1 proviral DNA was detected in the peripheral blood of all mothers, but p24 antigen and virus isolation were not detected. None of the HIV-1 markers, except for antibody, was detected in the samples from their children and placenta. These facts strongly suggest that there was no HIV-1 transmission from mother to child.

AIDS Serodiagnosis↗

PubMed1995

The inhibitory effect of the crude extract from a seaweed of Dygenea simplex C. Agardh on the in vitro cytopathic activity of HIV-1 and it's antigen production.

The crude water extract (NS-1) from a seaweed (Digenea simplex C. Agardh Rhodomelaceae) exhibited anti-human immunodeficiency virus (HIV)-1 activity in vitro. The inhibitory effect of the extract on the cytopathic activity of HIV-1 and it's antigen production was examined using a microplate method, immunofluorescent assay, and an HIV antigen detection kit (Abbott). NS-1 inhibited both the cytopathic effect of HIV-1 to MT-4 cells and the giant cell formation of Molt-4 cells infected with HIV-1.

Antiviral Agents↗

PubMed1995

Intracranial pheochromocytoma--a case of noradrenaline-secreting glomus jugulare tumor.

A 43-year-old female was admitted for a labile hypertension and depression. High levels of plasma and urinary noradrenaline strongly suggested a pheochromocytoma. However, clinical investigations revealed a normal adrenal gland and thoraco-abdominal region. Venous samples from multiple sites indicated and increase in noradrenaline in the left jugular vein. Using computed tomography and Gadolinium DTPA (diethylene triamine pentaacetic acid)-enhanced dynamic MR (magnetic resonance) imaging, a tumor was discovered in the cerebello-pontine angle. Carotid angiography showed the feeder arteries clearly. Therefore, the tumor was classified as a noradrenaline-secreting glomus jugulare tumor fed by the carotid artery. After embolization and subsequent medical therapy, blood pressure was well controlled. Twenty cases of intracranial pheochromocytoma have been reported to date. This is the second such case in Japan.

Adult↗

PubMed1995

An application of powder metallurgy to dentistry.

Generally, the dental casting method is used to fabricate dental prostheses made with metal. The method of fabricating dental prostheses from sintered titanium alloy has certain advantages: the elimination of casting defects, a sintering temperature that is lower than the melting point, and a shorter processing time. By examining (1) the properties of green, sintered compacts of titanium powder, (2) the effects of adding aluminum powder on the properties of green, sintered compacts of Ti-Al compound, and (3) the effects of adding copper powder on the properties of green, sintered compacts of Ti-Al-Cu compound, the authors developed a sintered titanium alloy on a trial basis. Because the properties satisfied the requirements of dental restorations, a powder metallurgical method of making dental restorations from this sintered titanium alloy was devised. Applications of such sintered titanium alloys for the metal coping of metal-ceramic crowns and denture base plates were discussed.

Aluminum↗

PubMed1994

Verotoxin induces hemorrhagic lesions in rat small intestine. Temporal alteration of vasoactive substances.

E. coli O157:H7 produces a cytotoxin active against Vero cells that has been termed verotoxin. In this study, we demonstrated that local intraarterial injection of verotoxin induced a decrease in blood flow and an increase in hemorrhagic lesions in rat small intestine. Significant increases in the area of hemorrhagic lesions were observed at 120 min after verotoxin injection. These lesions were produced by either verotoxin 1 or 2, but verotoxin 2 produced more extensive lesions. The temporal alteration of vasoactive substances in microcirculatory beds was determined after the administration of culture filtrate of E. coli O157:H7. Tissue-type plasminogen activator activity in regional plasma was significantly elevated as early as 30 min, suggesting that local fibrinolytic activation mediated by microvascular endothelium occurred. There was also early elevation of platelet-activating factor content in the ileal mucosa and its level remained significantly elevated thereafter. Intestinal blood flow, as determined by a laser Doppler flowmeter, started to decrease at about 45 min. The platelet-activating factor antagonist CV6209 was shown to attenuate the decrease in blood flow as well as the development of hemorrhagic lesions, demonstrating that platelet-activating factor is an important mediator for the microcirculatory damage. Accumulation of neutrophils demonstrated by myeloperoxidase activity in the intestinal mucosa and overproduction of oxygen-radicals from neutrophils of the mesenteric veins determined by the luminol-dependent chemiluminescence assay were observed at 60 min, corresponding with the decreased blood flow. Platelet-activating factor may be closely involved in the process of leukocyte accumulation and increased oxygen radical generation, because CV6209 also significantly attenuated these changes.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1994

[Serological study of Campylobacter jejuni infections in patients with Guillain-Barré syndrome].

The association between Campylobacter jejuni infection and Guillain-Barré Syndrome (GBS) was investigated serologically in 52 GBS patients. The specific antibody titers of immunoglobulin G class to C. jejuni were measured in the patient' sera using an enzyme-linked immunosorbent assay with acid-extracted antigen. The analysis showed that 31 (59.6%) of the 52 patients had evidences of recent C. jejuni infections in contrast to 16 (8.9%) of 180 healthy persons. The seropositive patients were analyzed with respect to the nature of their anticedent events. C. jejuni antibodies were found in 22 (75.9%) of the 29 patients with diarrhea, one patient with esophagus cancer, 4 (30.8%) of the 13 patients with upper respiratory infections, and 4 (50.0%) of the 8 patients without any symptoms, respectively. These findings support that there may be a close relationship between C. jejuni infection and the GBS with preceding diarrhea.

Adolescent↗

PubMed1994

[Shigella boydii strains having a provisional serovar isolated from travellers' diarrhea in Tokyo].

Two Shigella strains (85-634 and 94-30) isolated from two sporadic travellers with diarrhea who returning to Tokyo from abroad, did not react to any antisera to Shigella prepared commercially. These strains had the typical biochemical characteristics of S. boydii and were biochemically identical, and were positive in the Serény test and other tests for invasiveness; these indicate that they can cause shigellosis in humans. The results of serological analyses using the antisera to 6 kinds of provisional Shigella serovars, showed that both strains had provisional S. boydii serovar E16553. Although the serovar has been reported by Gross et al in the United Kingdom, this may be the first report in Japan.

Child↗

PubMed1994

Serodiagnosis by passive hemagglutination test and verotoxin enzyme-linked immunosorbent assay of toxin-producing Escherichia coli infections in patients with hemolytic-uremic syndrome.

Eight cases of hemolytic-uremic syndrome in which no pathogens were isolated were diagnosed serologically by a passive hemagglutination assay and a verotoxin (VT; Shiga-like toxin) enzyme-linked immunosorbent assay (ELISA). The passive hemagglutination assay employed formalinized sheep erythrocytes sensitized with soluble native antigen or heat-treated antigen (lipopolysaccharide [LPS]) from Escherichia coli O26, O111, O128, and O157 or flagellar antigen of nine different H serogroups of E. coli: H2, H7, H8, H10, H11, H12, H18, H19, and H25. All patients had antibodies against the native antigen and/or the LPS of E. coli O157, but positive agglutination with H7 was observed only in one patient. In the VT-ELISA with plates coated with purified VT 1 or VT 2, antibody against VT 2 was observed in the sera of five of six patients examined, but none of the patients possessed VT 1 antibody. These results indicate that the causative pathogen in these eight hemolytic-uremic syndrome cases is likely to be VT-producing E. coli O157. The passive hemagglutination assay described here is a very sensitive, simple, and rapid method. This assay is highly recommended for the serological diagnosis of VT-producing E. coli infections, particularly in patients infected by serogroup O157 strains. Furthermore, the VT-ELISA is useful in studying the role of VT in hemolytic-uremic syndrome.

Animals↗

PubMed1993

Detection of verocytotoxin from stool and serological testing of patients with diarrhea caused by Escherichia coli O157 : H7.

The detection of verocytotoxin (VT) in stool and measurement of antibodies against VT and three antigens (unheated-antigen, LPS, and flagellin) of Escherichia coli O157 : H7 in the serum of patients with diarrhea were examined. Five of 14 inpatients during an outbreak had fecal VT2 in stool taken within 5 days of onset to hospitalization. Among these 5, 3 of them also had fecal VT-producing E. coli (VTEC) serotype O157 : H7, whereas the other 2 did not. In the passive hemagglutination (PHA) test with formalinized sheep red blood cells sensitized with three VTEC O157 : H7 antigens, 49 (74.2%) of 66 outbreak patients and 3 of 3 sporadic cases had antibodies against both or one of unheated-antigen and LPS of E. coli O157, but none had antibody against flagellin. In addition, anti-VT2 antibody was demonstrated in serum samples from 15 (94%) of 16 inpatients and 2 (4%) of 50 outpatients in an outbreak by a VT-enzyme-linked immunosorbent assay (VT-ELISA). These results showed that serological assay particularly for antibodies against VT and unheated-antigen or LPS of VTEC O157 may provide a useful tool for diagnosis of infection with VTEC O157.

Adult↗

PubMed1993

[On the outbreak of Shigellosis in Tokyo, 1992].

In 1992, the number of cases of shigellosis in Tokyo increased remarkably, and a total of 10 separate outbreaks were confirmed. Except for 1 series where the causative strains was Shigella flexneri 3a, the other 9 outbreaks were caused by Shigella sonnei. Of note, 7 outbreaks were familial with less than 5 patients. The remaining 3 outbreaks occurred in a restaurant, a school and the dormitory of an orphanage, in which the organism was detected in 6 to 14 patients. In 4 of the familial outbreaks occurring in distant areas during August, ark shell was presumed to be the vehicle by epidemiological investigations and laboratory examinations. Analysis of isolates such as the antibiotic resistance pattern, plasmid profile, or colicine type in Shigella sonnei was useful in clarifying the commonality of each case and identifying the vehicle or transmission.

Adult↗

PubMed1993

[Epidemiology of sporadic pediatric enteritis patients due to verotoxin-producing Escherichia coli].

We tried to isolate verotoxin-producing Escherichia coli (VTEC) from 323 sporadic pediatric enteritis patients who came to three clinics in the Fukuoka area. We used the sorbitol-MacConkey medium for the isolation of VTEC O157:H7. For non-O157 VTEC strains we used the V1/PECS method. VT/PECS method was applied. VTEC strains were isolated from three patients (0.9%). None of the patients were seriously, ill or developed the hemolytic uremic syndrome. The three patients were all seen in the summer season, July and August. O157:H7 strains were isolated from two patients, and O145:NM from one. This study showed that sporadic enteritis cases due to VTEC exist in the Fukuoka area. In the future a rapid and easy method for the detection of VT or VTEC should be developed and commercialized to proceed with epidemiological studies of VTEC infections throughout Japan.

Bacterial Toxins↗

PubMed1993

[Cytotoxic effect of ammonia produced by Helicobacter pylori urease on the cultural cells].

We investigated the action of the ammonia produced by Helicobacter pylori urease on the cultured cells. The urease was purified from supernatant fluid of sonicated cell of H. pylori cultured on blood agar for 2 days at 37 degrees C under microaerophilic condition. Purification was carried out by DEAE-Sepharose chromatography, Phenyl-Sepharose chromatography, Sephacryl S-200 SF chromatography and fast protein liquid chromatography on Mono-Q. Vero, HeLa and Intestin 407 cells with or without the addition of 30 mM urea were exposed to the purified urease. Those cells showed cytotoxic effects within 80 minutes after addition of purified urease in the presence of urea. The ammonia production was observed on tissue culture medium within 10 minutes, and the ammonia concentration ranged from 5.56 mg/ml to 7.3 mg/ml and pH in the medium was over pH 9.0. No such effect was observed on the cells exposed to urease without urea. Ammonia water added to Vero cells showed the same cytotoxic effect within 70 minutes on the production of ammonia and raised the pH. However, when the cells were exposed to the ammonia water pre-neutralized to a given pH 7-8 using 1 N HCl cytotoxic effect was not observed. It was concluded that the cytotoxic effect of H. pylori urease was dependent on ammonia generated by hydrolysis of urea.

Ammonia↗

PubMed1993

Invasive strains of Escherichia coli belonging to serotype O121:NM.

Ten strains of Escherichia coli isolated from 10 travellers with sporadic diarrhea who were returning to Tokyo, Japan, from abroad were found to be of serotype O121:NM and were positive in the Serény test for invasiveness; this suggests that this serotype can cause a shigellosis-like illness in humans. The E. coli O121:NM strains were positive in the cell invasion test in HeLa cells. Analysis of the plasmid content of these strains showed that they contained a high-molecular-mass plasmid of 120 to 140 MDa which has been associated with invasiveness and were positive in an enzyme-linked immunosorbent assay for detection of the virulence plasmid-encoded proteins of Shigella spp. and enteroinvasive E. coli.

Adult↗

PubMed1993

[Combined use of chest X-rays and body mass index to predict pulmonary hemodynamics in patients with chronic obstructive pulmonary disease].

A study was undertaken to determine whether measurements of radiological indices from chest X-rays and body mass index (BMI) were useful in predicting pulmonary artery hypertension. Measurements of the cardiothoracic ratio (CTR) as well as right descending pulmonary artery diameter (RDPA) and BMI were made in 27 patients with chronic obstructive pulmonary disease (COPD). Mean pulmonary arterial pressure (mPA) correlated with CTR, RDPA and BMI. Multiple regression analysis gave the useful equation: predicted mPA = -3.523 + 0.196xBMI + 0.110xCTR + 0.786xRDPA (r = 0.704, p < 0.002). Fifteen patients were found to have pulmonary hypertension, defined as mPA > or = 20 mmHg. The sensitivity of CTR and BMI were 86.7%. The specificity of BMI was 83.3%. These results suggest that the measurements CTR, RDPA and BMI may be useful in screening for pulmonary hypertension in patients with COPD.

Aged↗

PubMed1992

A sensitive method for the detection of enterotoxigenic Escherichia coli by the polymerase chain reaction using multiple primer pairs.

In this study, a polymerase chain reaction (PCR) method has been developed for the detection of enterotoxigenic Escherichia coli (ETEC). Three different sets of oligonucleotide primers synthesized were used to amplify the enterotoxin genes of heat-labile (LTh) and heat-stable (STIa and STIb) enterotoxins of ETEC. These primers amplified a 627, 240, or 169 base pair (bp) DNA fragment from LTh, STIa and STIb gene, respectively, of the reference ETEC strains. The addition of RNase A (10 micrograms/ml) to the PCR reaction solution diminished nonspecific amplification of DNA fragments other than the enterotoxin genes. Five types of ETEC strains corresponding to the LTh, STIa, STIb, LTh-STIa, or LTh-STIb genotypes were distinguished by a single procedure of PCR using the mixture of the three sets of primers. PCR, hybridization, and conventional methods were subjected to one hundred stool specimens from diarrheal patients. It was found that PCR was the most sensitive method among them. These results suggested that PCR with triple primer pairs would be useful for the laboratory diagnosis of ETEC in the stool specimens.

Bacterial Toxins↗

PubMed1992

[Shigella flexneri strains having a new type antigen 89-141].

Two Shigella strains (89-141 and 89-11) isolated from the stool of patients returning from abroad (both from India) in Tokyo in 1989 showed an atypical serologic reaction of agglutination with only polyvalent antiserum to S. flexneri prepared commercially. These strains had the typical biochemical characteristics of S. flexneri and were biochemically identical. Both strains were positive for Serény test in guinea pig eye and cell-invasion test in HeLa cells. The strains also had virulence-plasmid encoding outer membrane proteins, indicating pathogenicity. The results of antigenic analyses showed that the strains were serologically identical to each other and gave significant cross-reactions with S. flexneri variant Y that has only group 3, 4 factor antigen. However, the results of reciprocal absorption tests showed that the O antigen of these strains was not identical to S. flexneri variant Y, and they were confirmed to have an additional type-specific antigen which is not included among the known S. flexneri type antigen I-VI or provisional type 88-893 which were proposed by us in 1992. Furthermore, one stock strain (TSH508) formally identified as S. flexneri variant X has this type antigen, suggesting that the new antigen can be classified into two subtypes by combination of group factor antigen. Strain 89-141 is designated as the test strain for this new type antigen of S. flexneri.

Adult↗