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T Asai

Publications and source records attributed to T Asai.

At least 19 recordsLinked to original sources
PubMed1992

Detection of human papillomavirus DNA in carcinomas of the nasal cavities and paranasal sinuses by polymerase chain reaction.

The authors retrospectively searched for human papillomavirus (HPV) types 16 and 18 in 60 cases of carcinoma arising from the nasal cavities (NC) and paranasal sinuses (PS) by using the polymerase chain reaction (PCR) on DNA extracted from formalin-fixed, paraffin-embedded tissues. In cases of SCC (n = 49), the authors also compared the clinical features of patients with HPV-positive and HPV-negative results to determine the clinical significance of HPV. HPV 16 and 18 were detected in 7 of the 49 cases (14%) of SCC. In the other histologic types of carcinoma (n = 11), neither HPV 16 nor HPV 18 was detected. No significant differences in the clinical features were observed between patients with SCC with HPV-positive and HPV-negative results. The results suggest that HPV 16 and 18 are implicated in the pathogenesis of SCC arising from the NC and PS. However, the presence of HPV is not related to local progression, occurrence of metastases, or the prognosis of the patients.

Adult↗
PubMed1992

T cell receptor V beta repertoire of double-negative alpha/beta T cells in patients with systemic sclerosis.

OBJECTIVE: To analyze the T cell receptor V beta gene on double-negative (DN) alpha/beta T cells, which are increased in number, on peripheral blood lymphocytes (PBL) from patients with systemic sclerosis (SSc). METHODS: The DN alpha/beta T cells were sorted by flow cytometry from PBL obtained from 3 patients with SSc. The V beta repertoire was analyzed by polymerase chain reaction. RESULTS: Only 1 or 2 V beta genes (V beta 5/7, 5, or 17) were predominantly expressed on DN alpha/beta T cells from these 3 patients. CONCLUSION: The V beta repertoire on DN alpha/beta T cells in PBL from patients with SSc is rather restricted.

Base Sequence↗
PubMed1992

DNA damage-inducible origins of DNA replication in Escherichia coli.

Upon induction of the SOS response in Escherichia coli, the mode of initiation of DNA replication is altered such that it can occur in the absence of normally required protein synthesis. This type of DNA replication has been termed induced stable DNA replication (iSDR). We examined the origin usage during iSDR and found that the initiation of iSDR occurs primarily in the oriC and terC regions of the chromosome in a manner completely independent of transcription, translation and DnaA protein. Minichromosomes (oriC plasmids) pOC23 and pOC81 were induced to replicate in the absence of DnaA protein and transcription after SOS induction. The results localized one of the iSDR origin activities in a 596 bp region which includes the minimal oriC.

Bacterial Proteins↗
PubMed1992

Electrophysiological properties of neurones following mild and acute retinal ischaemia.

Early electrophysiological changes following acute retinal ischaemia were studied by recording single or multiunit retinal ganglion cells and the electroretinogram (ERG) in barbiturate anaesthetized cats. Retinal ischaemia was initiated photochemically by platelet aggregation in retinal vessels which had been irradiated with monochromatic green light following an intravenous injection of Rose Bengal dye. No physiologically active ganglion cells were found within, or close to, the irradiated sites with chorioretinal oedema. On the other hand, in the areas 5-20 degrees away from the irradiation sites, ganglion cells had abnormally raised spontaneous (background) firing which obscured visually driven firing. The retinal areas where no physiologically active ganglion cells were found showed histopathological changes which are similar to those described for glutamate-induced retinal damage. Retinal areas where depolarized retinal ganglion cells were located, however, showed only minor vacuolation of the ganglion cell fibre layer. Early global electrophysiological changes following photochemically induced retinal vascular lesion were consistent with those predicted from the findings in the single cell study. Vascular lesions produced with high irradiation energy (10-30 J), which promote extensive chorioretinal oedema, resulted in gradual loss of visually responsive ganglion cells. Lesions produced by low-energy irradiation (2 J), causing slight narrowing of the blood columns in the vessels, on the other hand, resulted in significant increases in the amplitude and the implicit time of the ERG b-wave and the background firing of multiunit retinal ganglion cells. Electrophysiological changes associated with mild retinal ischaemia are analogous to physiological effects associated with exogenous glutamate or blockade of glutamate uptake.(ABSTRACT TRUNCATED AT 250 WORDS)

Action Potentials↗
PubMed1992

Studies on phosphoribosylpyrophosphate synthetase from Giardia intestinalis.

A substantial degree of purification, up to 3200-fold, with recoveries of 8-11% of phosphoribosylpyrophosphate (P-Rib-PP) synthetase from Giardia intestinalis extracts was achieved by the high resolution techniques of anion exchange chromatography and chromatofocusing columns on a fast protein liquid chromatography system. A Mono P chromatofocusing column gave rise to an enzyme peak eluting from the column at pH 4.5, indicating that the enzyme has an isoelectric point (pI) at approximately this value. The molecular weight of the enzyme was found to be 150,000 from a Sephacryl S-200 column. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis of the purified enzyme gave a single protein band with a subunit molecular weight of 38,000, indicating that the enzyme existed as a tetramer. The properties of G. intestinalis P-Rib-PP synthetase in terms of pH optimum, isoelectric point, subunit structure, phosphate requirement, metal and nucleotide specificity, appear to be very similar to those of the enzyme from other sources.

Animals↗
PubMed1992

Functional changes in thalamic relay neurons after focal cerebral infarct: a study of unit recordings from VPL neurons after MCA occlusion in rats.

We evaluated neuronal and histological changes of thalamic neurons 1, 4, 7, and 14 days after middle cerebral artery (MCA) occlusion in rats. After the somatosensory evoked potentials (SEPs) were measured from the cerebral cortex, the thalamic relay neuronal activities were recorded with a glass microelectrode following repetitive electrical stimulation of the contralateral forepaw at frequencies ranging from 1 to 50 Hz. In approximately 95% of the occluded rats, the ipsilateral somatosensory cortex and/or the subcortical somatosensory pathway developed infarct, resulting in SEP loss. We evaluated unit data from rats with abolished SEPs. The average firing rate of the nucleus ventralis posterolateralis (VPL) neurons in response to 25 stimulations at 30 Hz was significantly reduced to 0.1 spike/stimulus 1 day after MCA occlusion. In sham-operated rats, the same stimulation produced 0.7 spike/stimulus. The firing rate recovered to 0.4 spike/stimulus at 30-Hz stimulation 4 and 7 days after occlusion. This was followed by resuppression (0.1 spike/stimulus) 14 days after occlusion. Histological study revealed some abnormal neurons in the ipsilateral thalamus 7 days after occlusion. We were unable to find normal-shaped neurons in the VPL 14 days after occlusion. The present study demonstrates that cortical infarct produces functional and morphologic changes that gradually and progressively affect the ipsilateral thalamus, although incomplete transient recovery of somatosensory transmission may occur.

Animals↗
PubMed1992

Capillary filling analysis by digital subtraction angiography for vertebro-basilar insufficiency.

Vertebro-basilar insufficiency (VBI) is a vague clinical entity including several symptoms such as faintness, dizziness, vertigo. Millikan and Siekert reported a 'syndrome of intermittent insufficiency of basilar arterial system'. But vascular abnormalities responsible for such symptoms are often hardly diagnosed by conventional angiography, because vertebro-basilar artery systems have many kinds of anomalous congenital origins. Conventional angiography gives us arterial informations such as stenosis, occlusion and malformations, but it often fails to reveal capillary perfusions because of its relatively poor density resolution. Digital subtraction angiography (DSA) is considered to have improved density resolution, and it may enable us to detect vascular perfusions more sensitively in the capillary phase. In this study, we evaluated the usefulness of the capillary filling analysis in digital subtraction angiography for diagnosis of VBI.

Capillaries↗
PubMed1992

Lichen planus annularis: an immunohistochemical study.

Lichen planus annularis is a relatively rare skin manifestation of lichen planus. The mechanisms in the formation of annular lesions are not fully understood. We reported here a 57-year-old female with this disease. The eruption initially occurred as lichen-papules, then enlarged (bean-sized, umbilicated small plaques), and finally developed annular manifestations. We performed immunohistochemical examinations of specimens taken from different types of eruptions. In all specimens, HLA-DR was expressed in the focal keratinocytes adjacent to the dermal HLA-DR positive cell infiltration. Both in the initial papule and in the final annular lesion, expression of ICAM-1 was present only in the keratinocytes above the dermal cell infiltration, similar to HLA-DR. It is of interest that, in the umbilicated small plaques, the peripheral epidermis other than the central site extensively reacted to ICAM-1. LFA-1 expression was most prominent in the mononuclear cells impinging on the dermo-epidermal junction in all specimens. In addition, in the periphery of the umbilicated small plaques, which showed no bandlike dense cell infiltration nor degeneration of basement membrane, TNF-alpha, but not LFA-1, was positive in the infiltrated cells of the upper dermis. These results suggest that expressions of ICAM-1 and TNF-alpha in the peripheral keratinocytes and dermal infiltrated cells are important molecular events in the mechanisms of formation of the annular lesions.

Antigens, CD↗
PubMed1992

[Effect of erythromycin on intrapulmonary influx of neutrophils by intratracheal injection of lipopolysaccharide].

Recently, "low dose and long term" erythromycin (EM) treatment has been reported as effective on chronic lower respiratory tract disease, including diffuse panbronchiolitis (DPB). However the effective mechanism of EM is still obscure. In this study, we investigated the effect of EM on intrapulmonary influx of neutrophils by intratracheal injection of lipopolysaccharide (LPS), and the following results were obtained. 1) The intrapulmonary influx of neutrophils was significantly suppressed (p less than 0.001) in mice intraperitoneally injected with EM at 5 mg per animal 2 hr before intratracheal injection of LPS (control group: 6.5 +/- 0.8 x 10(5) vs EM-treated group: 1.7 +/- 0.3 x 10(5)), but not 10 hr before lung challenge. This inhibition was observed at 6 hr after lung challenge, and became maximum with 84% suppression at 24 hr. 2) The intrapulmonary influx of neutrophils was not affected when EM was injected intraperitoneally daily for 3, 7, or 14 days, and lung challenge was performed 24 hr after the final administration of EM. 3) The number of neutrophils in the peripheral blood was not affected by EM. These results suggest that EM treatment impairs the capacity for pulmonary inflammation by reducing, at least in part, the migration of neutrophils to inflammatory sites.

Animals↗
PubMed1992

Application of ozone disinfection to remove Enterococcus seriolicida, Pasteurella piscicida, and Vibrio anguillarum from seawater.

Survival of bacterial fish pathogens, including Enterococcus seriolicida, Vibrio anguillarum, and Pasteurella piscicida, in ozonated seawater was determined in a batch system. Bacterial counts of all fish pathogens decreased at more than 0.040 to 0.060 mg of total residual oxidants (TROs) per liter, whereas no decrease in viable counts was observed at less than 0.018 to 0.028 mg of TROs per liter. The 99% inactivation point was achieved at concentrations of 0.111 mg/liter for E. seriolicida, 0.063 mg/liter for P. piscicida, and 0.064 mg/liter for V. anguillarum within 1 min. Moreover, the mean 99 and 99.9% killing concentration-contact time (C.t) products were 0.123 and 0.186 mg.min/liter for E. seriolicida, 0.056 and 0.084 mg.min/liter for P. piscicida, and 0.081 and 0.123 mg.min/liter for V. anguillarum, respectively. However, the mean 99 and 99.9% C.t products for the mixed population in coastal seawater were 0.200 and 0.621 mg.min/liter. These results strongly suggest that ozone treatment at more than 1.0 mg of TROs per liter for several minutes is able to disinfect seawater for mariculture efficiently.

Animal Husbandry↗
PubMed1992

High correlation in antibody titers between the Sabin-Feldman dye test and an enzyme-linked immunosorbent assay detecting immunoglobulin G antibodies to the nucleoside triphosphate hydrolase of Toxoplasma gondii.

An enzyme-linked immunosorbent assay to detect immunoglobulin G antibodies against nucleoside triphosphate hydrolase, which is a specific and dominant antigen of Toxoplasma gondii, was developed, and the sensitivity and specificity of the test were compared with those of the Sabin-Feldman dye test. One hundred percent agreement was observed in comparative study between those tests on 37 positive and 50 negative human sera. Antibody titers in the enzyme-linked immunosorbent assay test, which were expressed as the reciprocal of the highest positive dilution of serum, were just 100 times those in the dye test on 81% (30 of 37) of the positive sera.

Animals↗
PubMed1992

Characterization of Japanese isolates of Aujeszky's disease virus by restriction endonuclease cleavage patterns, virulence in mice and thymidine kinase activity.

Twenty four cloned isolates of Aujeszky's disease virus collected from outbreaks of Aujeszky's disease from 1981 through 1989 in Japan were characterized by their restriction endonuclease (RE) cleavage patterns, virulence for mice and thymidine kinase (TK) activity. All of the isolates belonged to Type II of the four types classified by Herrmann et al. (1984). Based on the number and migration rate of the restriction fragments, the isolates were divided into 7 groups with Bam HI, 9 groups with Kpn I, 3 groups with BstE II and 2 groups with Sal I. The results indicate that the RE analysis, especially with Bam HI and Kpn I, provides useful epidemiological information about field isolates of Aujeszky's disease virus. All of the isolates showed virulence for mice ranging from 6.9 to 63.0 (PFU/LD50). It was interesting that the Nagano S87 strain, which had the highest virulence for the mouse, showed unique RE cleavage patterns with four enzymes. On the other hand, ara-T-resistant, TK-negative strain, was avirulent for mice (greater than 10(6.4) PFU/LD50). All of the isolates investigated in this study showed TK activity by the thymidine plaque autoradiography.

Animals↗
PubMed1992

Effect of interferon (IFN) on refractory idiopathic thrombocytopenic purpura: administration of 6 million units of recombinant IFN alpha-2b.

Five patients (six courses) with refractory idiopathic thrombocytopenic purpura (ITP) were given 6 million units of recombinant interferon (IFN) alpha-2b in 12 doses to achieve an improved response rate compared to previous studies using 3 million units. From the initial IFN administration, the platelet count increased from a pre-treatment level of 20.7 +/- 17.7 x 10(3)/microliters (mean +/- SD) and reached its first peak in weeks 2 or 3 of therapy (p < 0.05). In week 5, the platelet count made its second and maximum peak (66.5 +/- 57.9 x 10(3)/microliters; p < 0.05). A relatively good response of the platelet count (an increase to > 50 x 10(3)/microliters) was observed in three patients (four courses) out of five. These responses were not much faster or more improved than in previous reports, and a dose of 6 million units may be too large to treat some ITP patients. The platelet-associated IgG level showed a tendency to be reduced with IFN therapy. The mechanism for the increase of the platelet count may be the modification of platelet autoantibody production.

Adult↗
PubMed1992

[The use of a Swan-Ganz catheter with a fast-response thermistor for the measurement of right ventricular performance during anesthetic management of pheochromocytoma].

We used a Swan-Ganz catheter with a fast-response thermistor to measure the right ventricular ejection fraction (RVEF) during the anesthetic management of two patients with epinephrine-dominant pheochromocytomas. Pre-operatively, one patient received alpha adrenergic blocking agents (prazocine, doxazocine) to control the blood pressure but the other patient did not receive any agents. In the latter patient who did not receive alpha adrenergic blocking agents, right ventricular function was depressed post-operatively in the recovery room. The importance of preoperative preparation with alpha adrenergic blocking agents was confirmed by the reductions in RVEF and RVEDVI (right ventricular end-diastolic volume index) after resection of the tumor. Not only left heart monitoring but also right heart monitoring with RVEF and RVEDVI are recommended for the proper management of a patient with pheochromocytoma.

Adrenal Gland Neoplasms↗
PubMed1992

The effects of different techniques of internal mammary artery harvesting on sternal blood flow.

We investigated chest wall blood flow in a canine model to determine if the technique used to harvest the mammary artery has a differential effect on residual chest wall blood flow. Eight dogs underwent bilateral internal mammary artery mobilization; one artery was harvested as a pedicle and the other was harvested as a skeletonized vessel. Residual blood flow to the chest wall distribution of each artery was measured with radioactive microspheres. Chest wall blood flow was significantly decreased from preharvest levels after internal mammary artery mobilization regardless of the technique used. Tissue blood flows decreased to 46.9%, 22.1%, and 41.2% of baseline values for the manubrium (p < 0.01), sternum (p < 0.001), and ribs (p < 0.05), respectively. Residual sternal blood flow on the side of the skeletonized vessel was significantly greater than on the side of the pedicle graft (2.60 +/- 0.68 versus 1.27 +/- 0.27 cm3/min/100 gm, p < 0.001). We conclude that minimization of tissue mobilization during internal mammary artery harvesting may reduce sternal devascularization. This finding may have clinical significance with respect to lowering the incidence of sternal wound complications in coronary bypass surgery using the internal mammary artery as a bypass conduit.

Animals↗
PubMed1992

[Estimation of pulmonary vascular permeability by indocyanine green in permeability pulmonary edema].

In this study we attempted to estimate pulmonary vascular permeability by indocyanine green (ICG). Permeability pulmonary edema was produced in 9 adult dogs by injecting 0.08 ml/kg oleic acid. We injected 50 mg ICG intravenously in 18 dogs (9 dogs with pulmonary edema and 9 control dogs). We measured the time course of ICG concentrations in pulmonary arterial blood, ICG concentration of peripheral lung tissue, tissue/serum ICG concentration ratios, and wet/dry lung weight ratios. The following results were obtained. The time course of ICG concentration in pulmonary arterial blood showed peak values at 2 minutes and became constant at 5 or 10 minutes after injection. The ICG concentration in peripheral lung tissue, tissue/serum ICG concentration ratios, and wet/dry lung weight ratios in the pulmonary edema group were significantly higher than those in the normal group. There was a strong linear correlation between wet/dry lung weight ratio and ICG concentration in peripheral lung tissue, with correlation coefficients of r = 0.936 (p < 0.01) in the right lung and r = 0.901 (p < 0.01) in the left lung. From these results, we conclude that estimation of pulmonary vascular permeability by ICG is a useful method.

Animals↗