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Biomedical subjects

N Ohashi

Publications and source records attributed to N Ohashi.

At least 19 recordsLinked to original sources
PubMed1992

Diversity of immunodominant 56-kDa type-specific antigen (TSA) of Rickettsia tsutsugamushi. Sequence and comparative analyses of the genes encoding TSA homologues from four antigenic variants.

There are several antigenic variants in Rickettsia tsutsugamushi, and a type-specific antigen (TSA) of 56-kilodaltons located on the rickettsial surface is responsible for the variation. The primary structures of the protein in two variants, Gilliam and Karp, have been reported independently by us and Stover et al. by cloning and sequencing the corresponding genes (Ohashi, N., Nashimoto, H., Ikeda, H., and Tamura, A. (1990) Gene (Amst.) 91, 119-122; Stover, C. K., Marana, D. P., Carter, J. M., Roe, B. A., Mardis, E., and Oaks, E. V. (1990) Infect. Immun. 58, 2076-2084). In the present study, genes encoding the TSA homologues of the other four variants, Kato, Kawasaki, Kuroki, and Shimokoshi, which are all distinguishable serologically, were cloned and sequenced, and consequently, it became possible to compare the primary structures of the six antigenic variants. The sequence analyses revealed a complete open reading frame encoding 55,308-56,745-dalton proteins with 521-532 amino acids, in which a putative signal peptide consisting of 22 amino acids was recognized at the NH2-terminal end. Transcription of the gene is regulated by several tandem promoters. All TSA molecules have the characteristics of transmembrane proteins with alternating hydrophobic and hydrophilic regions, and contain four variable domains with spans of 16-40 amino acids which are located in the hydrophilic regions in the molecule and show different amino acid sequences among the strains. Phylogenetic classification among the R. tsutsugamushi strains based on TSA homologues supports the antigenic relationships known in the closely and distantly related strains.

Amino Acid Sequence↗
PubMed1992

The relationship between smooth and saccadic components in smooth pursuit.

Eye movements in smooth and pathological (saccadic and ataxic) pursuit patterns were separated by the use of the inverse fast Fourier transform. Results showed that the smooth component was significantly smaller while the saccadic component was significantly greater in the pathological pursuit patterns than in the smooth pursuit pattern. In addition, the smooth and saccadic components showed a linear relationship. These findings give some support to the threshold theory in explaining the relationship between smooth pursuit and saccades.

Adaptation, Physiological↗
PubMed1992

Prophylactic chemotherapy for primary and recurrent superficial bladder cancer: preliminary results. The Hokkaido University Bladder Cancer Collaborating Group.

A multicenter trial for postoperative prophylaxis of the recurrence of superficial Ta-T1, G1-G2 bladder cancer was performed. Eligible patients with primary or recurrent superficial bladder cancer were randomized into four groups. For the primary cases, intravesical instillation of drugs [group A, 20 mg Adriamycin (ADM) + 200 mg cytosine arabinoside (CA) in 30 ml physiological saline; group B, 10 mg peplomycin (PEP) + 200 mg CA in 30 ml physiological saline; group C, 2 mg neocarzinostatin (NCS) + 200 mg CA in 30 ml physiological saline; and group D, control] was carried out once a week for 2 weeks, once every 2 weeks for 14 weeks, once monthly for 8 months, and, finally, once every 3 months for 1 year. For the recurrent cases, intravesical instillation of 20 mg ADM + 200 mg CA in 30 ml physiological saline as described above and daily oral administration of another drug [group E, 300 mg/day UFT; group F, 200 mg 5-fluorouracil (5-FU)/day; group G, 30 mg ubenimex/day; and group H, no oral drug] was performed. The postoperative follow-up period was 3-36 months. A total of 193 primary cases and 121 recurrent cases of superficial bladder cancer were evaluated. The cumulative 12-month nonrecurrence rates for the primary cases were 86.2% in group A, 78.1% in group B, 82.1% in group C, and 68.4% in group D. The cumulative nonrecurrence rate obtained using ADM+CA (group A) was significantly higher than the control value. On the other hand, no significant difference was found in the cumulative nonrecurrence rates calculated for the recurrent cases, regardless of the oral drug given. Intravesical instillation of ADM+CA for primary superficial bladder cancer was considered to be useful, but the long-term effect of intravesical instillation remains to be elucidated. Further refinement of this regimen is necessary for effective prophylaxis of the recurrence of superficial bladder cancer.

Administration, Intravesical↗
PubMed1992

Vascular cross-compression of the VIIth and VIIIth cranial nerves.

A 53-year-old male patient had been suffering from severe aural symptoms (pulsatile right-sided tinnitus and paroxysmal dizziness attacks with nausea) and right hemifacial spasm. Treatment had involved stellate ganglion block with lignocaine and the injection of intravenous sodium bicarbonate solution for attacks of Menière's syndrome and facial nerve block with lidocaine for hemi-facial spasm. Despite these treatments, the dizzy attacks became more frequent, developing into the clustering state. Air CT cisternography and vertebral angiography demonstrated an enlarged and curved vertebral artery. Vascular cross-compression of the VIIth and VIIIth cranial nerves was therefore suspected. Microvascular decompression was performed. After operation, the pulsatile tinnitus, dizziness and hemifacial spasm disappeared. From the present case and a review of the literature, we conclude that vascular cross-compression of the VIIIth cranial nerve should be an indication for microvascular decompression only when symptoms of vascular cross-compression of the VIIth cranial nerve are also seen.

Facial Nerve↗
PubMed1992

Initiation of sinusoidal tracking eye movements in man.

Smooth pursuit eye movement was recorded with a DC amplifier during horizontal sinusoidal target motion at 0.3, 0.6, 0.8, 1.0 and 1.2 Hz and a peak-to-peak amplitude of 20 degrees. Eye movement was digitalized at 100 Hz and 12 bits. From the digitalized eye movements, the maximum position error, the correlation coefficient and regression coefficients between stimulus and eye position were calculated in each half cycle. The A/D conversion and calculation were performed using a 16 bit microcomputer (NEC PC 98). Thirteen healthy volunteers with normal smooth pursuit patterns were examined. The correlation coefficient increased, but the maximum position error and the two regression coefficients decreased as the target moved. However, all four stabilized from about the 3rd half cycle regardless of the target frequency. These findings indicate that the smooth pursuit of a sinusoidally moving target reaches the maintenance at about the 3rd half cycle after initiation of two half cycles from the beginning of the target motion. This might be due to a prediction (or learning) of periodicity.

Adult↗
PubMed1992

[Localization of androgen receptor in male sex organ, accessory sex organs and external genital skin].

Previously, we established an anti-androgen receptor (AR) monoclonal antibody. Using the antibody, we investigated immunohistological AR localization in human testes, epididymides, seminal vesicles and scrotal skins. The testes, epididymides and scrotal skins were obtained from a prostate cancer patient without pre-hormonal therapy undergoing bilateral orchiectomy. The seminal vesicles were obtained from a bladder cancer patient undergoing radical cystectomy. The tissues were immediately frozen in liquid nitrogen and kept at -80 degrees C until used. Cryostat-frozen sections were cut at 5 microns and stained by an indirect method. We obtained the following results. 1) In the testes, nuclei of Leydig cells were stained though Sertoli cells were not stained. AR localization in Leydig cells which produce testosterone suggests autocrine or intracrine mechanism in the testis. 2) In the epididymides, nuclei of epithelial cells of epididymal ducts were stained, while muscles and connective tissues were not stained. In the seminal vesicles, nuclei of glandular epithelial cells were stained. 3) In the scrotal skins, the cells of squamous cell layer have positive stainings. The cells in the upper portion of squamous cell layer were stained more intensely than the cells in the lower portion. The basal layer was not stained. The cells of the outer root sheath of hair follicles in the scrotal skins were also stained. 4) In androgen target organs, AR-positive cells and AR-negative cells were mixed in the epithelium of a glandular duct, which suggests heterogeneity of AR localization in the androgen target organs.

Animals↗
PubMed1992

[Analysis of pedestrian injuries in traffic accidents: impact point, injury portion, and injury severity].

We conducted in-depth case studies of traffic accidents involving 118 pedestrians, who were struck by the fronts of bonnet-type cars. The data were reviewed in order to correlate injury severity with pedestrian age, and area of body contact, contact surface of vehicle or the local environment, and impact speed. It was found that head injuries caused by impacts against the top surface of car bonnets and leg injuries caused by front bumpers both showed high incidence rates. Both head and leg injuries caused by striking the vehicle were more severe than those caused by striking the road surface. In cases of impact between the head and the solid portion of the vehicle, such as the A-pillar, or in cases of secondary impact between the head and underhood solid structures such as shock tower, injuries tended to be more severe. The location of head impact varied according to the stature of the pedestrians.

Accidents, Traffic↗
PubMed1991

A comparative view of Rickettsia tsutsugamushi and the other groups of rickettsiae.

Recent researches on the rickettsial group microorganisms are summarized in their comparative aspects of morphology, cultivation and multiplication, susceptibility to chemotherapeutics, chemical structure of envelopes, nucleic acid, protein constitution, and gene structures. From this overview, Rickettsia tsutsugamushi seems to have different properties from the others and should be reclassified into a new genus, and a new species name as Orientia tsutsugamushi is proposed.

Bacterial Proteins↗
PubMed1991

Otoneurological manifestations of the Shy-Drager syndrome.

Three patients with the chief complaints of dizziness while standing up or blackouts were diagnosed correctly as having the Shy-Drager syndrome at the Department of Otolaryngology. Both the electrocardiogram R-peak to R-peak interval and the Schellong test revealed disorders of the autonomic nervous system in each of these cases. Electronystagmography also demonstrated pathology of the oculomotor system and/or central vestibular system. Postural balance was also abnormal in one of the cases. Auditory brain-stem responses were normal in all three cases.

Electrocardiography↗
PubMed1991

Effect of insulin treatment on the regeneration of the remnant pancreas after major pancreatectomy in dogs.

The effect of exogenous insulin treatment on the pancreatic regeneration after major pancreatectomy was evaluated in dogs. More than 92% of the pancreas was removed near the duodenum with the main pancreatic duct left intact. All 26 dogs developed diabetes mellitus (DM) immediately after surgery, and these dogs were divided into two groups: insulin-treated group (n = 19) and noninsulin-treated group (n = 7). All seven dogs in the noninsulin-treated group died within seven weeks after surgery, whereas all dogs in the insulin-treated group survived until the twelfth week, except for six dogs sacrificed on the seventh week, and finally seven (53.8%) of 13 dogs recovered from DM. DNA and polyamine syntheses in the remnant pancreatic tissue at the third day increased more significantly in the insulin-treated group than in the noninsulin-treated group. Sigma IRI in IV-GTT was maintained more significantly in the insulin-treated group, and the regeneration rate at the seventh week was also significantly higher in the insulin-treated group than in the noninsulin treated group. Furthermore, the regeneration rate of the remnant pancreas at seventh week correlated well with DNA synthesis and ornithine decarboxylase activity on the third day. The exogenous insulin treatment after major pancreatectomy enhanced the proliferation of the remnant pancreas within the first week, and it maintained endogenous insulin secretion, promoting pancreatic regeneration.

Animals↗
PubMed1991

A case report of supernumerary tooth and review of literature.

A boy visited an ear-nose and throat clinic for serous rhinorrhea and a tumor-like mass in the nasal cavity. X-ray and computered tomographies showed a bone-like mass with a slightly radiolucent center which seemed to stem from the nasal septum. A supernumerary tooth in the nasal cavity was extirpated under local anesthesia. In some reports, complications of supernumerary tooth were severe and involved areas other than the nose (cleft lip and/or palate, bilateral aniridia and ectopia lentis, familial adenomatous polyposis coli, ventricular septal defect or patent ductus arteriosus). A case had a risk of inducing severe intracranial complication. Therefore we must not overlook a supernumerary tooth.

Child↗
PubMed1991

Specific amplification of Rickettsia tsutsugamushi DNA from clinical specimens by polymerase chain reaction.

Polymerase chain reaction (PCR) was used to detect Rickettsia tsutsugamushi-specific DNA in clinical specimens. The primer pair used for PCR was designed from the nucleotide sequence of the gene encoding the 56-kDa antigen of the Gilliam strain. Theses primers led to a 78-bp fragment by amplifying the genomic DNAs from five serovariants, i.e., the Gilliam, Karp, Kato, Kawasaki, and Kuroki strains of R. tsutsugamushi, and also the DNA from blood clots of patients with scrub typhus, even at the early stage of onset of the disease. This indicates that this method is suitable for the diagnosis of scrub typhus.

Base Sequence↗
PubMed1991

Use of monoclonal antibodies against Rickettsia tsutsugamushi Kawasaki for serodiagnosis by enzyme-linked immunosorbent assay.

Monoclonal antibodies (MAbs) against Rickettsia tsutsugamushi Kawasaki were prepared. The crossreactivity tests of the MAbs performed by using antigenically distinct strains of R. tsutsugamushi in immunofluorescence and immunoblotting analyses indicated that the Kawasaki strain contains a strain-specific epitope and also contains a common epitope on the 56-kDa polypeptide cross-reactive with the Gilliam strain, group- and subgroup-specific epitopes on the 46-kDa polypeptide, and a subgroup-specific epitope on the 25-kDa polypeptide. By using the strain-specific MAb for serodiagnosis of tsutsugamushi disease (or scrub typhus fever), we have established a method which was designated the inhibition enzyme-linked immunosorbent assay. The principle of the method is to measure the percentage of inhibition of antigen absorption on a MAb-coated plate by antibody-positive sample sera which were mixed with the antigen suspension. The advantages of this test for practical use are that (i) crude antigen can be used, i.e., purification of the antigen is not required; (ii) the test is more sensitive than immunofluorescence; (iii) the final judgment of plus or minus is clear-cut; and (iv) rickettsial antigenic types in the patients can be distinguished by this test.

Antibodies, Bacterial↗
PubMed1991

Cerebral autoregulation in patients with orthostatic hypotension.

The present study was conducted to determine the relationship between autonomic nervous function and cerebral autoregulation in 17 patients with vertigo or dizziness. Autonomic nervous function was examined by measuring systolic blood pressure response and dynamic electrocardiogram R-peak to R-peak response upon standing up. Regional cerebral autoregulation was examined by comparing cerebral blood flow in both supine and standing positions with single photon emission computed tomography. Moreover, the relationship of each of these three measures to postural provocation of symptoms was studied. The findings indicated that autonomic nervous dysfunction does not influence cerebral autoregulation, but autonomic nervous dysfunction was related to postural provocation of symptoms. This might indicate that impaired autoregulation in the brain stem or the peripheral vestibule, which could not be detected by the single photon emission computed tomography, played a role in inducing vertigo or dizziness in patients with orthostatic hypotension.

Adult↗
PubMed1991

Involvement of the VIIIth cranial nerve and the brainstem in patients with hemifacial spasm.

Twenty-seven patients with hemifacial spasm underwent neurotological (auditory and equilibrium) examinations to evaluate the VIIIth cranial nerve and/or brainstem involvement. Radiological examinations were performed to evaluate the underlying abnormalities. Twenty patients had abnormal neurotological findings, with the VIIIth cranial nerve involvement being suggested in 10 and brainstem involvement in the other 10. Radiological examinations indicated that vascular abnormalities could be detected more often in the patients with brainstem involvement than in those with VIIIth cranial nerve involvement.

Brain Stem↗