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Biomedical subjects

T Okitsu

Publications and source records attributed to T Okitsu.

At least 37 records · Page 2Linked to original sources
PubMed1997

[Distribution of serogroups of Vibrio cholerae non-O1 non-O139 with specific reference to their ability to produce cholera toxin, and addition of novel serogroups].

A total of 1898 strains of Vibrio cholerae non-O1 non-O139, which had been collected worldwide for the past 3 year period of 1994-1996, were serogrouped. The strains were also examined for presence of cholera toxin (CT) gene (ctx) and NAG-ST gene, and strains which carried to ctx were further analyzed for their ability to produce CT. In addition, attempts were made to establish novel serogroups for those serologically untypable strains. Of those examined, 1,774 strains of V. cholerae non-O1 non-O139 was classified into 128 known serogroups while 50 strains were found to belong to R type, and the rest of the 74 strains could not be serotyped. Distribution of the serogroups did not seem to correspond to either the strains geographic distribution or sources of isolation. Of those serologically untypable strains, 38 novel serogroups (O156-O193) were established and added to our reference of V. cholerae antigenic schema. It was also found that antisera raised against many V. cholerae strains included R antibodies. This indicates that any V. cholerae antisera for diagnostic purpose should be absorbed with the reference R strains, CA385, before use. There were luminescence producing strains among those sucrose and VP reaction negative strains. Subsequent DNA/DNA homology analysis revealed that they were identified as V. cholerae. This points to a possibility that strains tentatively identified as Vibrio mimicus by conventional biochemical tests may have included luminescent strains of V. cholerae. It is thus highly recommended that strains in question should be tested for the luminescence production in order to differentiate V. cholerae from V. mimicus. Of those 1989 strains examined, 37 strains (ca. 2%) were found to produce CT. Interestingly, CT producing strains were prevalent in serogroup O141; 10 strains out of 16 strains (63%) were positive for CT. The evidence calls for a caution to possible occurrence of cholera-like diarrhea caused by V. cholerae O141 in the future.

Cholera Toxin↗
PubMed1997

[Detection of the thermostable lipase gene (lipAH) in clinical isolates of Aeromonas hydrophila belonging to the major O serogroups O11, O16 and O34].

On the basis of DNA hybridization data and phenotypes, most pathogenic strains of Aeromonas hydrophila are grouped into hybridization group 1 (HG1). These pathogenic strains secret the theromostable lipase, and it's gene (lipAH) has been cloned and sequenced. The present study was performed to identify the pathogenic strains of A. hydrophila by the polymerase chain reaction (PCR) technique to detect the lipAH. Synthetic oligonucleotide primers (lipAH-ns-1 and -na-1) were used in the PCR. The PCR identified 80% of lipAH-positive strains, consisting of seven of the 11 O11 strains (64%), 13 of the 15 O16 strains (87%) and 25 of the 30 O34 strains (83%) in clinical isolates of A. hydrophila used in this study.

Aeromonas hydrophila↗
PubMed1997

[Isolation of enterohemorrhagic Escherichia coli (O157:H7) by an immunomagnetic separation method].

Three sporadic cases of enterohemorrhagic Escherichia coli (EHEC) O157 infection which occurred in Kanagawa in 1996 were investigated. In an attempt to determine sources of the infection, a novel method of immunomagnetic separation (IMS) was employed to isolate the bacterium from feces, foods, and other associated items. In the first case, strains of EHEC O157:H7 producing Vero toxin (VT) 2 were isolated from both feces of the patient and suspected food (cattle liver) kept at a restaurant, and the strains were found to be genotypically identical through an analysis of pulsed-field gel electrophoresis (PFGE). Subsequent investigation in the meat processing store, from which the above cattle liver had been retailed to the restaurants revealed that the store was contaminated with EHEC O157:H7 producing both VT1 and VT2. In the second case, a strain isolated from the patient was EHEC O157:H7 producing both VT1 and VT2 while strains isolated from the patient's family (without apparent symptom) and the suspected facility were O137:NM producing VT2. PFGE analysis indicated that the latter two strains were genotypically identical, suggesting that the facility thus contaminated with EHEC O157 caused the infection in question. In the third case, EHEC O157:NM producing VT2 was isolated from 4 out of 7 family members including the patient, and these strains were found to be genotypically identical by subsequent PFGE analysis. Source of the infection was, however, not determined due to lack of suspected food items. In this context, four slaughterhouses in Kanagawa Prefecture were investigated for presence of EHEC O157. As a result, strains of EHEC O157:H7 producing VT1 and VT2 were isolated from the contents of cattle's distal colon and surface of the skinned carcasses. Additional attempt was also made to determine a possibility of river water being contaminated with EHEC O157. The bacterium was, however, not isolated from water samples collected from 4 major rivers in the prefecture (at 10 collecting sites). Experiments were undertaken in order to evaluate the use of IMS in isolation of EHEC O157 from food items, with different pre-enrichment media and conditions. The results indicated that pre-enrichment by trypticase soy broth at 36 degrees C for 6 h followed by inoculating onto sorbitol MacConkey agar plate containing cefixime and tellurite was most appropriate to isolate EHEC O157 strains.

Adolescent↗
PubMed1997

[Studies of Vibrio cholerae O140 (serogroup Hakata) isolated from river water].

Strains of Vibrio cholerae O140, which were isolated from river (Hikichi River) water in Kanagawa, Japan, were studied for their biochemical characteristics and toxin genes, and analyzed by an amplified polymorphic DNA method in comparison with both clinical and environmental isolates of V. cholerae O140. Biochemical characteristics of 4 river isolates studied were found to be unanimous by conventional tests and a commercially available identification kit (Api 50 CH). The strains were also found to react positively with both cholera Inaba factor (C) and V. cholerae O140 specific factor (F). A total of 34 V. cholerae O140 strains including the 4 stains, a reference strains (487-95), 25 strains isolated from samples of river or sea water in Japan, 4 strains isolated from a patient and imported foods, was investigated by the PCR method for presence of ctx, zot, hlyA, and NAG-ST genes. It was found that all strains carried the hlyA gene but none of them carried either ctx, zot, or NAG-ST genes. V. cholerae O140 shared a common antigenic structure with pathogenic V. cholerae strains but its pathogenicity seems to be comparable to that of V. cholerae non-O1 non-O139. Subsequent RAPD analysis indicated that the strains can be divided into 9 groups. Four strains from the Hikichi River showed the same RAPD pattern. The results suggest that the analysis can be a useful epidemiological tool for V. cholerae O140, and that V. cholerae O140 persists in the Hikichi River throughout years.

Japan↗
PubMed1997

Rapid screening method for identification of cholera toxin-producing Vibrio cholerae O1 and O139.

A novel method of identifying cholera enterotoxin (CT)-producing Vibrio cholerae serogroups O1 and O139 was developed. The method uses degradation of NAD as a specific biochemical marker for the CT-producing strains. The substrate NAD at a concentration of 100 mumol/liter was markedly degraded when it was incubated at 37 degrees C for 2 h with the CT-producing stains at a final cell density equivalent to that of a twofold dilution of a McFarland no. 1 standard. NAD degradation was monitored by an enzyme-amplified color development assay. Subsequent tests conducted with a total of 119 strains of V. cholerae, including both clinical and environmental isolates, confirmed a significant correlation between NAD degradation and CT production for all V. cholerae strains belonging to serogroups O1 and O139. Since 2 of 11 non-O1, non-O139 V. cholerae strains not carrying the CT gene degraded NAD, serotyping of the strains prior to the test is recommended.

Bacterial Typing Techniques↗
PubMed1997

Middle ear inflation as a treatment for secretory otitis media in children.

Clinical evaluations of middle ear inflation for secretory otitis media (SOM) were performed with special emphasis on the influence of seasonal and aging factors. One hundred and forty-nine children between the ages of 3 and 9 years (227 ears) were all diagnosed as SOM by pneumatic-otoscopic findings, and type B tympanogram (TG) at 3 weeks or more after the onset of acute SOM or the initial observation of SOM. Middle ears were inflated by Politzer's method or by our modified method once or twice each week for 2 months. After inflation, TG displayed two different time sequences: one group changed to the A or C type immediately after inflating the ear one or more times, but usually returned gradually to the B type (TG-improved group): and the other group remained without any changes (TG-unchanged group) for the duration of this study. The healing rate in the TG-improved group was significantly higher than in the TG-unchanged group at the 2-month endpoint. The cure rate of SOM was significantly higher in spring than in autumn in the TG-unchanged group but not in the TG-improved group. There were almost no differences between the healing rates in the 3-5 and 6-9 year-old children. When a TG-unchanged ear is found in autumn during the 2-month inflation treatment, more careful and forcible treatments should be introduced later, especially to children between the ages of 3 and 9 years.

Child↗
PubMed1996

[Isolation and incidence of Vibrio cholerae from river water].

The prevalence of Vibrio cholerae contamination in river water derived from 20 sites of 18 rivers in Kanagawa, Japan, was investigated during a period from July to September, 1987, and from one of the 20 sites in August, 1988 and in February, 1989, V. cholerae non-O1 was found in all samples at concentrations of 0.9-->1,400 MPN/100 ml. Higher amounts of the organism were observed in the samples from estuaries. V. cholerae O1 was detected in samples collected in August, 1988 and in February, 1989 at concentrations of 150 MPN/100 ml and 1.5 MPN/100 ml, respectively. From 1989 to 1995, water samples were collected monthly from 10 sites of 10 rivers to detect V. cholerae. V. cholerae O1 and non-O1 were detected in 3.6% (30 of 840) and in 61.1% (513 of 840) in the water samples examined, respectively. Overall, V. cholerae was found in 62.9% (528 of 840). Both types, O1 and non-O1, of organisms were detected in 15 samples. These results indicated that river water was contaminated frequently with V. cholerae non-O1 and sporadically with V. cholerae O1 throughout the year. Only one strain of V. cholerae O1 out of 543 V. cholerae strains was found to be a producer of cholera toxin. During these studies, the selectivity of 3 media for V. cholerae O1 was evaluated, and PMT agar was found to be the best.

Japan↗
PubMed1996

[Rapid detection of the hemolysin genes in Aeromonas sobria by the polymerase chain reaction].

The hemolysin of Aeromonas sobria is one of the important virulence factors in this organism. Rapid detection and identification test for A. sobria is important for early and specific diagnosis of this infectious disease. We evaluated the polymerase chain reaction (PCR) for the rapid detection of A. sobria. Two pairs of synthetic oligonucleotide primers (ASA1-s and a; AerAAS-s and a) were used in PCR technique to detect the different hemolysin genes (ASA1 and aerAAS) in A. sobria. The PCR identified 91% of ASA1-positive and 23.4% of aerAAS-positive strains in beta-hemolytic A. sobria. Other species of Aeromonas, Plesiomonas shigelloides, Vibrio cholerae O1 and V. parahaemolyticus tested were negative in the PCR with two pairs of primers. The PCR technique for detection of two hemolysin genes suggested the possibility of application of this method for detection of A. sobria in A. sobria-associated infections.

Aeromonas↗
PubMed1996

Occurrence of urease-positive Vibrio parahaemolyticus in Kanagawa, Japan, with specific reference to presence of thermostable direct hemolysin (TDH) and the TDH-related-hemolysin genes.

A total of 132 strains of V. parahaemolyticus isolated from patients and from the suspected causal food items of past food poisoning cases occurring in Kanagawa Prefecture, Japan, were examined for the ability to hydrolyze urea, with specific reference to the presence of the thermostable direct hemolysin gene (tdh) and the gene for thermostable direct hemolysin-related hemolysin (trh). Ten strains belonging to five different O-antigen serotypes were positive for urea hydrolysis (UH+), and four of these strains did not carry tdh. A total of 106 strains carried tdh, but less than 6% of them were UH+, whereas all trh-carrying strains were UH+. The evidence suggests that urea hydrolysis is not a reliable marker for identifying tdh-carrying V. parahaemolyticus strains in Japan (the Pacific Northeast) but may be a marker for trh-carrying strains.

Bacterial Proteins↗
PubMed1995

Evaluation of DNA fingerprinting by PFGE as an epidemiologic tool for Salmonella infections.

To evaluate DNA fingerprinting as an epidemiologic tool, pulsed-field gel electrophoresis (PFGE) was performed on isolates of Salmonella, including S. typhimurium, S. thompson, and S. enteritidis. Chromosomal DNA was digested with the restriction endonucleases Bln I and Xba I. The patterns of S. thompson and S. typhimurium isolates from various sources were different from one another. There was no correlation between the phage type and the digestion pattern of S. enteritidis isolates. Some strains belonging to one phage type were distinguished by their PFGE pattern in this study. These results suggest that the Bln I and Xba I digestion patterns of chromosomal DNA are useful for epidemiological analysis of an outbreak of Salmonella infection or food poisoning.

DNA Fingerprinting↗
PubMed1995

Anosmia following head trauma: preliminary study of steroid treatment.

Twenty patients with post-traumatic anosmia were subjected to olfactory function testing, including olfactory acuity tests using a T & T olfactometer and an intravenous olfaction test. T & T tests revealed complete loss in 14 patients. In the intravenous olfaction test, 14 patients showed no response and 5 patients showed abnormal responses. The severity of olfactory dysfunction showed no correlation with background factors such as the site of head trauma, the presence of the fracture of skull, the presence of unconsciousness, or the presence of head operation. As a preliminary study, seventeen patients were administered a corticosteroid, a topical nasal drop of 0.1% betamethasone for 12 patients and an oral administration of prednisolone for 5 patients. Four patients showed slight recovery of olfactory function following a corticosteroid therapy. Effects of corticosteroids on olfaction might be explained by regeneration of olfactory receptor cell axons and reestablishment of contact with cells in the olfactory bulb.

Adrenal Cortex Hormones↗
PubMed1995

[Causative agent of the so-called "light disease of shrimps" is luminescent Vibrio cholerae non-O1].

A number of luminous fresh-water shrimps were found in a fish preserve in Lake Biwa, Shiga Prefecture, in the middle of July, 1994, and most of them died within several hours after collection (the so-called "light disease of shrimp"). Four luminous organisms were isolated from a dead shrimp. Although the phenotypic properties of these strains were similar to those of V. cholerae or V. mimicus, a representative strain, 838-94, was shown to have a high level (79%) of DNA homology with V. cholerae type strain, ATCC 14035 and a low level (45%) of relatedness to V. mimicus type strain, ATCC 33653. Therefore, these isolates were identified as V. cholerae. The four strains fell into serogroup O28 of V. cholerae. On the other hand, none of the isolates had CT nor NAG-ST genes. The results obtained herein clearly demonstrate that these organisms isolated from luminous shrimps are luminescent V. cholerae serogroup O28.

Animals↗
PubMed1994

[Survival of Vibrio cholerae O139 Synonym Bengal in water from a river].

Survival of five strains of Vibrio cholerae, including serotypes O139 Synonym Bengal, O1 El Tor, and non-O1 were compared in water from a river. These bacteria were mixed with water from a river and the water filtered through 0.45 micron millipore filters, respectively, to yield a concentration of 10(6) CFU/ml and incubated at 5 degrees C and 20 degrees C for 21 days. The survival curve of V. cholerae O139 was almost the same with V. cholerae O1 and non-O1. The number of these bacilli decreased to less than 10(2) CFU/ml at 7 days of the incubation at 20 degrees C. When incubated at 5 degrees, however, these bacilli survived much longer and the number decreased to the same value after 14 days. Therefore, these results indicated that the temperature during the incubation greatly affects the survival of V. cholerae. On the other hand, when the water was filtered and used for the experiment, V. cholerae survived longer than in the polluted water. From these observations, if the river is polluted with V. cholerae O139 in the future, it is suggested that the distribution of V. cholerae O139 in the river may be the same as the present condition with V. cholerae O1 and non-O1.

Fresh Water↗
PubMed1990

Changes in tympanograms after middle ear inflation.

To determine the effects of politzerization or middle ear (ME) inflation by a catheter, we studied the ME pressures in 35 ears with retracted tympanic membranes (29 patients). Serial tympanometries were performed prior to the ME inflation and immediately, 10, 20, 30 and 60 min after the procedure. The present study showed that the more negative the ME pressure was before the inflation, the greater the pressure change was after the treatment. The elevated ME pressure induced by the procedure declined rapidly within the first 20 min after the inflation. This was probably caused mainly by spontaneous elimination of ME gas through the eustachian tube and gas absorption from the ME mucosa. During the post-inflation course, some ears demonstrated more negative pressures in the ME cavity than those before the inflation. The present investigation demonstrated that the use of inflation to treat secretory otitis media had short-term benefits which could be improved by minimizing gas absorption.

Acoustic Impedance Tests↗
PubMed1989

[The c protein fractions of group B streptococci: its distribution and relation to heat-labile antigens for the agglutination method].

Distribution of the c protein fractions of group B streptococci and relation to heat-labile antigens for agglutination were investigated. The results were summarized as follows: 1. Analysis of antigenicity of the c protein in group B streptococcal strains isolated revealed that 74% of the type Ia/c strains carried only alpha antigen, and 76% of the type Ib/c strains contained both alpha and beta antigens. Component of the c protein fractions in most of type Ia/c strains isolated was different from that in reference strains. 2. Of 37 Ia/c alpha strains, 45.9% were determined non-typable, 32.4% were Ia/W, 13.5% were Ia/S, and 8.1% were Ia/Q in the agglutination for heat-labile antigens. Of 8 Ia/c alpha beta strains, 87.5% were Ia/Q, and 12.5% were Ia/SW. Of 5 Ia/c beta strains, 60% were Ia/Q, and 40% were Ia/QW. Of 19 Ib/c alpha beta strains, 68.4% were Ib/-, and 31.6% were Ib/S. Of 5 Ib/c alpha strains, 60% were Ib/-, and 40% were Ib/S. One Ib/c beta strain was Ib/-. 3. Because trypsin-sensitive portions of the beta antigens were lost, preparation of antigens for agglutination by pancreatic digestion could not exactly reflect results of the precipitation method.

Agglutination Tests↗
PubMed1989

Labyrinthine fistulae caused by cholesteatoma. Improved bone conduction by treatment.

In five cases of labyrinthine fistulae caused by extensive cholesteatoma, more than 30-dB improvement in bone conduction was observed in four postoperative cases and in one case after preoperative administration of antibiotics. In each case, a fistula of more than 2 mm in length was present at the lateral semicircular canal, and membranous labyrinthine wall was exposed when the cholesteatoma membrane was removed. These five cases were considered to be in the stage of serous labyrinthitis. The experience with these cases shows that emergent antibiotic treatment and surgery are appropriate for cases with reduced bone conduction in which labyrinthine fistula caused by cholesteatoma is suspected. In addition, as the reduction of bone conduction does not necessarily preclude the possibility of good postoperative hearing, tympanoplasty may be appropriate even for cases with markedly reduced bone conduction due to labyrinthine fistulae.

Adolescent↗