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Biomedical subjects

N Ohashi

Publications and source records attributed to N Ohashi.

At least 163 records · Page 9Linked to original sources

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↗

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↗

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↗

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↗

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↗

Analysis of smooth pursuit by the fast Fourier transform.

Eye movement during smooth pursuit examination was converted to digital values and analyzed by the fast Fourier transform (FFT). It was found that the power spectra differences between the eye and target movements at 0.3 Hz were significantly lower in the pathological pursuit patterns (saccadic and ataxic pursuit patterns). In addition, sums of the power spectra difference above 0.3 Hz were significantly greater in pathological pursuit patterns.

Ataxia↗

[Five years' experience with new medical examiner's system in Tsukuba].

Medical examiner's system has been authorized by the act of Autopsy and preservation of corpses and the government ordinance for medical examiner's system since 1949 in Japan, and introduced only in five large cities (Tokyo metropolis, Osaka, Kobe, Yokohama, Nagoya). Recently in Ibaraki Prefecture, new forensic medical service system (Tsukuba Medical Examiner's office) was instituted. This new system is not authorized by the government ordinance, but authorized by the regional ordinance of Ibaraki prefectural governor, therefore this system is enforce only in Ibaraki prefecture. In our new system, medical examiner does not have discretionary power to order an autopsy, and family have a right to reject it, therefore an autopsy rate is very low (about 2%). One hundred and forty four autopsies have been conducted under this system. Ninety four of 144 autopsy cases (67%) were dead from sickness or natural death, in remaining 50 cases manner of death was accidental, suicidal or undetermined. The medical examiner does not conduct autopsies for criminal investigation or homicide cases in Ibaraki prefecture. These autopsies are conducted at the department of legal medicine, University of Tsukuba.

Autopsy↗

Cloning and sequencing of the gene (tsg56) encoding a type-specific antigen from Rickettsia tsutsugamushi.

A type-specific antigen (TSA) in Rickettsia tsutsugamushi is a 56-kDa protein located on the rickettsial surface. The gene (tsg56) encoding the TSA was isolated from R. tsutsugamushi Gilliam strain. Sequencing revealed an open reading frame of 1572 bp encoding a 524-amino acid (aa) protein with an Mr of 56,053. The deduced aa sequence consists of a 22-aa signal sequence and the mature TSA sequence (502 aa; Mr 53,803), whose N-terminal portion has the aa sequence determined directly in our previous study [Ohashi et al., Infect. Immun. 57 (1989) 1427-1431]. Alternate localization of hydrophobic and hydrophilic regions was recognized in the TSA molecule, suggesting that the TSA is a transmembrane protein. The codon usage in the A + T-rich (59%) tsg56 gene reflects a high A + T content of R. tsutsugamushi. The 5'-flanking region contains sequences similar to those of ribosome-binding sites and promoters of Escherichia coli.

Amino Acid Sequence↗

[Serodiagnosis of scrub typhus by dot-blot method].

Microimmunofluorescence (IF) and immunoperoxidase tests are generally used for the serodiagnosis of scrub typhus. While these tests give satisfactory results in the hands of experienced personnel, they can be troublesome for inexperienced technicians. To develop a simpler diagnostic method, dot-blot assay was examined in this study. Six antigenically distinctive strains of Gilliam, Karp, Kato, Shimokoshi, Kawasaki and Kuroki of Rickettsia tsutsugamushi and a strain of Rickettsia sibirica were dotted on a nitrocellulose sheet by a dot-blot instrument. The sheets were treated with patient sera, followed by peroxidase-conjugated anti-human immunoglobulin-antibody and then with the substrate of the enzyme, and the color development on the dots was compared by naked eye observation. By this procedure, anti-rickettsial antibody-positive patient sera showed clear color development on at least one, usually several dots, while the very faint color was observed by the treatment with antibody-negative sera. On the other hand, it was ascertained that the antigens on nitrocellulose sheets were stable for at least 4 months at room temperature. Therefore the diagnostic kits were prepared, and the practical application of this procedure for diagnosis of scrub typhus were tested in Shizuoka and Miyazaki Prefectural Pabulic Health Laboratories. The results indicated a very good comparability between the dot-blot assay and IF-tests, and this dot-blot method was ascertained as a simple and useful method for the scrub typhus serodiagnosis.

Adolescent↗

Characterization of a new antigenic type, Kuroki, of Rickettsia tsutsugamushi isolated from a patient in Japan.

The Kuroki strain of Rickettsia tsutsugamushi, isolated from a patient in Kyushu, Japan, has a major, type-specific antigenic polypeptide which is distinct from the prototype strains in size (58 kilodaltons), in antigenicity, and in its cleavage pattern with N-chlorosuccinimide. These results indicate that Kuroki is another antigenic type of R. tsutsugamushi.

Antigens, Bacterial↗

Difference between visual feedback and visual suppression upon the stabilization of body sway in normal subjects.

We developed a system to feedback the center of foot pressure by vision using a microcomputer. The subjects were instructed to adjust the center of foot pressure (displayed on the computer display at real time) to the point of intersection of the two stable (horizontal and vertical) lines on the computer display. The peak of the power spectra of body sway shifted significantly to the higher frequency range in the Y component (the lateral direction) in the visual feedback condition. Thus, we conclude that the visual feedback of body sway depends mainly on the error signals between the fovea and the image in the lateral direction to stabilize body sway.

Adult↗

Blood pressure abnormalities as background roles for vertigo, dizziness and disequilibrium.

In 3 years, a total of 1,291 patients have undergone equilibrium examinations because of vertigo, dizziness and disequilibrium in the Otoneurological Division of Toyama Medical and Pharmaceutical University. Abnormal blood pressures (hypertension, hypotension and orthostatic hypotension) were found in 18.67% (241 patients). Hypotension was found significantly more often in peripheral vestibular disorders and hypertension in central nervous system disorders. Furthermore, the incidence of orthostatic hypotension was statistically higher in hypertensive patients than in hypotensive patients. Therefore, we conclude that blood pressure measurement by the Schellong test method in patients with vertigo, dizziness and disequilibrium is very important.

Adolescent↗

Purification and partial characterization of a type-specific antigen of Rickettsia tsutsugamushi.

A type-specific antigen (54- to 56-kilodalton polypeptide) in the envelope of Rickettsia tsutsugamushi was purified from each of three prototype strains (Gilliam, Karp, and Kato) by a combination of mild anionic detergent treatment, gel filtration, and reverse-phase high-performance liquid chromatography. The purified antigens from the three strains were shown to have similar amino acid compositions: primarily aspartic acid, glutamic acid, and glycine, with lesser amounts of cysteine, methionine, and tyrosine. The N-terminal amino acid sequences of the antigens were 74.3% homologous among the three strains.

Amino Acid Sequence↗

Serodiagnosis of scrub typhus with antigens immobilized on nitrocellulose sheet.

This study was designed to develop a simple method for serodiagnosis of scrub typhus. The basis of the method is detection of anti-Rickettsia tsutsugamushi antibody in patient serum by reaction with antigens dot blotted on a nitrocellulose sheet (NCS). The final evaluation of the reaction is performed by observing the color intensity which develops as a result of sequential treatments of the NCS with peroxidase-conjugated anti-human immunoglobulin G or immunoglobulin M antibody and with the substrate of the enzyme. After various trials, we found that the best results were obtained by using a purified antigen which adhered to an NCS at 0.2 to 2 micrograms of protein per dot and a test serum diluted 1,000- to 4,000-fold. Under these conditions, almost all antibody-positive sera showed a distinct color at the dot on the NCS, so that a positive reaction could be distinguished by the naked eye from a negative reaction with antibody-negative sera, which developed only a faint color. A comparison of the results of screening of antibody-positive and -negative sera by this method and the immunofluorescence test showed that both methods produced similar results. From these results, it is concluded that this dot immunoassay can be useful for the serodiagnosis of scrub typhus.

Antibodies, Bacterial↗

The furosemide VOR test for Menière's disease. A preliminary report.

In order to easily detect endolymphatic hydrops and to avoid the side effects, we applied a furosemide VOR test in 24 patients with unilateral Meniere's disease, 6 patients with delayed endolymphatic hydrops, and 2 patients with labyrinthine syphilis. Immediately preceding an i.v. injection of 20 mg furosemide, and then 30, 60, 90 min after the administration, the VOR test was repeatedly performed. The slow-phase velocity in the VOR test was measured during harmonic sinusoidal rotation with eyes closed. Increased or decreased VOR-DP% beyond the normal range (10%) was referred to as positive. In 13 out of 24 cases (54%) with Menieres's disease, positive results were observed. Moreover, 4 out of 6 (67%) with delayed endolymphatic hydrops, one case out of 2 with labyrinthine syphilis were also positive in the furosemide VOR test. From these clinical investigations, we have concluded that the furosemide VOR test appeared to be another type of clinical test for the detection of vestibular endolymphatic hydrops.

Adult↗

Tracheobronchial rupture caused by blunt chest trauma: acute respiratory management.

The clinical management of 12 patients with major intrathoracic tracheobronchial rupture (complete, 3; incomplete, 9) due to blunt trauma has been reviewed and compared with that of two groups of patients with chest injuries not involving the tracheobronchial tree, 17 patients with multiple rib fractures and 17 with chest injuries requiring thoracotomy for control of pneumothorax and hemothorax. The effect of injury on ventilatory function was significantly greater in the patients with tracheobronchial injury in whom an elevated PCO2 at the time of admission was associated with a poor prognosis. Conventional ventilatory management with endotracheal intubation and positive pressure ventilation causing increased air leakage produced further deterioration of pulmonary function in four of the patients with tracheobronchial disruption. The use of a double-lumen endobronchial tube in two patients with tracheobronchial rupture facilitated ventilatory support and subsequent operative management.

Adolescent↗

Immunoblotting analysis of anti-rickettsial antibodies produced in patients of Tsutsugamushi disease.

The reactivity of sera from patients of Tsutsugamushi disease (scrub typhus) with the antigenic polypeptides of Rickettsia tsutsugamushi was analyzed by the immunoblotting method. The reactivity varied greatly among the sera of individual patients tested. IgG and IgM antibodies of most patients reacted with the 54-56 kilodalton (54-56K) polypeptide located on the rickettsial surface, suggesting that this polypeptide is a predominant antigen in the infection. Other polypeptides of 60K, 50-52K, 46-47K, 35K, and 21-25K were reactive with some but not all sera. From the reactivity of these polypeptides, it was suggested that the 54-56K polypeptide is both strain-specific and group-specific, the 60K polypeptide is group-specific, and the 35K and 21-25K polypeptides are subgroup-specific. IgG antibodies seem to be more cross-reactive with polypeptides of multiple strains than IgM antibodies and have a tendency of increased cross-reactivity that was observed in the sera obtained at the later stage of illness.

Antibodies, Bacterial↗