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Biomedical subjects

T Okitsu

Publications and source records attributed to T Okitsu.

At least 55 records · Page 3Linked to original sources

[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↗

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↗

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↗

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↗

[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↗

[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↗

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↗

[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↗

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↗

Positive intratympanic pressure in the morning and its etiology.

Intratympanic pressures were measured by tympanometer in forty ears free from disease. In the recumbent position, the first tympanogram was obtained in the morning at awakening, before swallowing. The second pressure measurement was performed in the upright position after swallowing and chewing. Twenty-two ears showed positive pressure in the middle ear before swallowing and decreased pressure after swallowing. The present results revealed no evidence of continuous gas absorption from the middle ear during sleep. The other experiment demonstrated that raising of the PCO2 level by hypoventilation increased the pressure in the middle ear. The results suggested indirectly a diffusion of carbon dioxide to the middle ear cavity from its surrounding tissue. The intratympanic pressure seems limited in part to the partial pressure gradient of gases between the middle ear cavity and its surrounding tissue when ventilation through the Eustachian tube is impaired.

Acoustic Impedance Tests↗

Forward-backward tracing tympanometry.

Two tympanograms were routinely recorded from each ear by altering the pressure in the external auditory meatus (EAM), first in the decreasing direction (Forward Tracing: TG-F) and next in the increasing direction (Backward Tracing: TG-B). In a normal ear the TG-F peak tended to be in the negative pressure area and that of the TG-B in the positive area. When the middle ear pressure was adjusted to the atmospheric pressure in a model, the TG-F peak always indicated a negative pressure and that of TG-B always showed a positive pressure value. As long as the same model was used, the magnitude of the difference of the two peaks was identical irrespective of the middle ear pressure, but it was influenced by the speed of EAM pressure change, and a linear increase was observed up to the speed of 70 mmH2O/s, both in the normal ear and in the model. In ears with pathology, considerable variation was noted in the magnitude of the peak shift. These findings seem to suggest that the peak location of a unidirectionally drawn tympanogram cannot be regarded as indicating the precise middle ear pressure. The middle ear pressure can be estimated more accurately by averaging the peak pressures of TG-F and TG-B of Forward-Backward Tracing Tympanogram.

Acoustic Impedance Tests↗

Tympanograms in ears with small perforations of the tympanic membranes.

It has been believed that in an ear with a perforation, the tympanogram becomes a straight line due to the lack of compliance change in response to the pressure change in the external auditory meatus. Recently, however, we found two types of tympanogram with distinctive characteristics in ears with small perforations. In the first tympanogram type, when the external auditory meatus pressure was changed in the decreasing direction, the compliance peak was formed in the positive-pressure area, whereas it was formed in the negative-pressure area when it was changed in the increasing direction. The difference of the pressure at which compliance peak was obtained was great. The second tympanogram type was unique, with multiple notches similar to those of electronystagmographic recordings of the jerky nystagmus. Knowledge of these tympanograms helps in recognizing small tympanic-membrane perforations.

Acoustic Impedance Tests↗