Biomedical subjects

T Ogata

Publications and source records attributed to T Ogata.

At least 109 records · Page 6Linked to original sources

PubMed1999

Lack of class II transactivator causes severe deficiency of HLA-DR expression in small cell lung cancer.

Small cell lung cancer (SCLC) is characteristically not associated with tumour-infiltrating lymphocytes. Since SCLC has been reported to show marked reduction of class I HLA, the reduced expression has been considered a means of escaping anti-cancer immunity. However, HLA-DR expressed in cancer cells is now known to contribute to anti-cancer immunity. To clarify the difference in HLA-DR expression between SCLC and non-small cell lung cancer (NSCLC), and the mechanism, the expression and the cis- and trans-acting factors involved were investigated. HLA-DR was not immunohistochemically detected in any SCLC and could not be induced by interferon gamma (IFN-gamma) in any SCLC cell line, whereas HLA-DR was expressed to varying degrees and was easily induced in NSCLC. SCLC cell lines lacked class II transactivator (CIITA) even after IFN-gamma induction, whereas NSCLC cell lines expressed CIITA. The other class II HLA-specific transcription factors were expressed and genomic DNA of HLA-DR, including the promoter, was conserved well both in SCLC and in NSCLC cell lines. CIITA transfection improved the expression of HLA-DR in SCLC. In conclusion, the lack of CIITA results in severe deficiency of HLA-DR expression in SCLC. Since CIITA has also been reported to induce class I HLA, CIITA transfection might make it possible to establish effective anti-cancer immunotherapy against SCLC through the up-regulation of class I and class II HLA.

Blotting, Northern↗

PubMed1999

Gonadoblastoma, mixed germ cell tumor, and Y chromosomal genotype: molecular analysis in four patients.

This study reports on Y chromosomal genotypes of three patients with gonadoblastoma and one patient with gonadoblastoma and mixed germ cell tumor. Molecular analysis for 35 Y chromosomal loci was performed for DNA samples taken from peripheral leukocytes and lymphoblastoid cell lines, showing that the four patients shared the region between DYS267 at interval 4A and DYF50S1 at interval 6D, with the exception of the region around DYS202 at interval 5K. In the patient with gonadoblastoma and mixed germ cell tumor, Y chromosomal material was preserved in the gonadoblastoma but was lost from the mixed germ cell tumor. The results, in conjunction with previous reports, suggest that GBY (gonadoblastoma locus on the Y chromosome) may be located to a roughly 5-Mb pericentromeric region between DYS267 at interval 4A and DYS270 at interval 5A. The presence of Y chromosomal material in gonadoblastoma is consistent with GBY being involved in the development of gonadoblastoma, and the absence of Y chromosomal material in mixed germ cell tumor would be explained as a consequence of Y chromosomal loss from rapidly proliferating gonadal cancer cells.

Adolescent↗

PubMed1999

Microwave Spectrum, Structure, and Nuclear Quadrupole Coupling Constants of 1-Bromo-1-fluoroethane.

The microwave spectrum of 1-bromo-1-fluoroethane, CHBrF-CH(3) and CHBrF-CH(2)D ((79/81)Br), has been studied for the first time from 8 to 41 GHz. A least-squares analysis of the observed a- and b-type transition frequencies gave rotational and centrifugal distortion constants and components of the bromine nuclear quadrupole coupling constant tensor in the principal axes system as follows: A = 8979.428(5) MHz, B = 2883.898(3) MHz, C = 2310.535(3) MHz, Delta(J) = 0.74(2) kHz, Delta(JK) = 2.49(3) kHz, Delta(K) = 5.3(5) kHz, delta(J) = 0.146(1) kHz, delta(K) = 2.75(4) kHz, chi(aa) = 493.49(29) MHz, chi(bb) - chi(cc) = -38.89(11) MHz, and ||chi(ab) || = 161.8(28) MHz for the CH(79)BrF-CH(3) species; A = 8979.257(5) MHz, B = 2859.072(3) MHz, C = 2294.572(3), Delta(J) = 0.76(2) kHz, Delta(JK) = 2.51(3) kHz, Delta(K) = 4.5(4) kHz, delta(J) = 0.145(1) kHz, delta(K) = 2.70(4) kHz, chi(aa) = 412.42(27) MHz, chi(bb) - chi(cc) = -32.56 (11) MHz, and ||chi(ab) || = 133.3(3) MHz for the CH(81)BrF-CH(3) species. The structural parameters are calculated from the 24 observed rotational constants, and electronic properties of the carbon-bromine bond in 1-bromo-1-fluoroethane are evaluated from the observed nuclear quadrupole coupling constants. These molecular properties are compared with those of other related molecules. The molecular structure of 1-bromo-1-fluoroethane is found to be very close to that of 1,1-difluoroethane except for the C-Br bond. Copyright 1999 Academic Press.

Journal Article↗

PubMed1999

Giant trichoblastoma mimicking malignancy.

We report a case of giant trichoblastoma, a rare benign hair germ tumor. A 73-year-old man presented with a soft-tissue mass on his upper arm. Magnetic resonance imaging analysis revealed an unique mosaic pattern on T2-weighted images. Needle biopsy disclosed a keratinizing tumor suggesting squamous cell carcinoma. The size of the tumor was 9.5 x 7 x 9.5 cm, one of the largest trichoblastomas ever reported. The rarity and gigantic size of the tumor, together with its misleading clinical features, prompted us to report our case.

Aged↗

PubMed1999

Developmental stage-specific involvement of angiotensin in murine nephrogenesis.

Angiotensinogen-deleted mice (Agt-KO) show phenotypes of hypotension and renal atrophy. To investigate whether an alternative pathway other than angiotensin II (AII), i.e., processed angiotensin fragments, may play a biological role in nephrogenesis, we analyzed a congenic line of Agt-KO fetuses and neonates derived from two sources: one (Agt-KO/He) from mating with heterozygous angiotensinogen-deleted mice and the other (Agt-KO/Ho) from mating homozygous angiotensinogen-deleted mice. Although Agt-KO/He did not show a typical phenotype at birth, these mice showed papillary atrophy 2 weeks later and thereafter, a marked increase in renal size, i.e., pelvic dilatation. In contrast, Agt-KO/Ho showed renal abnormalities at birth and subsequently died. TUNEL staining and electron microscopy revealed that accelerated papillary apoptosis was present at birth in Agt-KO/Ho and caused abnormal papillary development; however, apoptosis was not detected in Agt-KO/He, suggesting that different mechanisms for the abnormal renal development exist in Agt-KO/He and Agt-KO/Ho. Two-week administration of an angiotensin fragment (3-8), angiotensin IV (AIV), to Agt-KO/He markedly attenuated the renal atrophy, decreasing the incidence from 81% to 14%. However, administration of AIV to fetal Agt-KO/Ho through the mother did not decrease the incidence. This is marked contrast to AII, which prevented renal atrophy in both fetal and neonatal periods. It is therefore suggested that AIV is involved in nephrogenesis in a developmental stage-specific manner.

Angiotensin II↗

PubMed1999

Confirmation of domoic acid production of Pseudo-nitzschia multiseries isolated from Ofunato Bay, Japan.

Production of domoic acid (DA), the responsible toxin for amnesic shellfish poisoning, was examined for 44 strains of Pseudo-nitzschia spp. isolated from Ofunato Bay, Japan. Only one strain which was identified as Pseudo-nitzschia multiseries produced DA in a level comparable to Canadian strains. No significant DA was detected in the rest of the strains, indicating that toxic P. multiseries does not bloom in a high density in the bay.

Canada↗

PubMed1999

Chromosomal structures of bottom fermenting yeasts.

A genomic comparison of bottom fermenting yeasts was performed by pulsed-field gel electrophoresis and Southern blot analysis with some S. cerevisiae gene probes. We confirmed that strains of bottom fermenting yeast have four chromosomes originating from S. bayanus. Since the structures of these chromosomes were recombined with S. cerevisiae chromosomes, these S. bayanus chromosomes could be differentiated from S. cerevisiae chromosomes using Southern hybridization. Our Southern hybridization results indicate that bottom fermenting yeasts have both chromosomes originating from both S. cerevisiae and S. bayanus. It was reconfirmed that top fermenting yeast should be classified as S. cerevisiae, based on the chromosomal structure. The chromosomal structure of S. pastorianus CBS1538, the type stain of S. pastorianus, was also investigated. This strain has chromosomes originating only from S. bayanus. S. carlsbergensis CBS1513 has chromosomes originating from both S. cerevisiae and S. bayanus. From these results, we contend that bottom fermenting yeasts should be classified as S. carlsbergensis.

Blotting, Southern↗

PubMed1999

EPR imaging for in vivo analysis of the half-life of a nitroxide radical in the hippocampus and cerebral cortex of rats after epileptic seizures.

Recently, we developed an in vivo temporal electron paramagnetic resonance (EPR) imaging technique to be applied to the brain of a rat, into which a blood-brain barrier (BBB)-permeable nitroxide radical, 3-methoxycarbonyl-2,2,5,5-tetramethylpyrrolidine-1-oxyl (PCAM) was injected intraperitoneally. This imaging technique made it possible to measure decay rates of a nitroxide radical in multiple regions of the brain simultaneously. Using this technique, the half-life of PCAM was estimated from the exponential decay of the signal intensity derived from the temporal EPR images in the hippocampus and cerebral cortex of rats after a kainic acid (KA)-induced seizure. The hippocampal half-life of PCAM after KA-induced seizures was significantly prolonged (p < .01), whereas the prolongation of the cortical half-life was not significant. These findings suggest that following a KA-seizure, the intrahippocampal ability to reduce the nitroxide radical is impaired, but the ability is intact in the cerebral cortex. This is the first in vivo quantitative EPR imaging study that has a bearing on the pathogenesis of KA-induced seizures in the brain.

Animals↗

PubMed1999

SHOX: pseudoautosomal homeobox containing gene for short stature and dyschondrosteosis.

A growth gene has been postulated, on the basis of genotype-phenotype correlations in patients with sex chromosome aberrations, to exist on the short-arm pseudoautosomal region (PAR1) of the sex chromosomes. Recently, Rao et al. have identified a novel homeobox containing gene, SHOX (short stature homeobox containing gene), from the distal part of PAR1, by means of a positional cloning method. SHOX is most strongly expressed in bone marrow fibroblasts, implying that SHOX plays a positive role in bone growth and development. In addition, SHOX is expressed from an inactive X chromosome, as well as an active X and a normal Y chromosome, suggesting that SHOX escapes X-inactivation and exerts the dosage effect in sex chromosome aberrations. Mutational analysis of SHOX was done in about 400 patients with idiopathic short stature, identifying three types of heterozygous nonsense and missense mutations. Furthermore, fluorescence in situ hybridization analysis of SHOX was performed in six Japanese families with dyschondrosteosis, demonstrating microdeletions involving SHOX in all the patients. The results indicate that SHOX is responsible for short stature and dyschondrosteosis.

Chromosome Mapping↗

PubMed1999

A reaction kinetics model of water sonolysis in the presence of a spin-trap.

The time development of the concentration of a spin-trapped OH radical was studied by electron spin resonance at various sound intensities and various 5,5-dimethyl-1-pyrroline N-oxide (DMPO) concentrations in water sonolysis. The lifetime of the spin-trapped OH radical was also studied, and factors governing sonolysis are discussed. We found that the production of spin-trapped OH radical increases with increasing ultrasound intensity. The lifetime of a spin-trapped OH radical decreases linearly with increase in sonication time. This result suggests that an unknown scavenger is produced by ultrasound. Based on the above results, we suggested a model of the reaction kinetics and estimated the production rate of OH radical from this model.

Journal Article↗

PubMed1999

Serum hyaluronan as a predictor of hepatic regeneration after hepatectomy in humans.

BACKGROUND: The capacity for hepatic regeneration after hepatectomy is important for allowing surgeons to determine the appropriate extent of resection. However, conventional preoperative liver function tests are unsatisfactory for estimating the post-operative regenerative capacity of the remnant liver. The aim of this study was to evaluate the relationship between preoperative serum hyaluronan and hepatic regeneration. METHODS: Preoperative serum hyaluronan levels and the hepatic regeneration rate were estimated in 49 patients using computerized tomographic volumetry. The hepatic fibrotic rate was calculated with non-tumorous tissues stained with Azan-Mallory. Immunolocalization of factor VIII-related antigen (FVIIIAg) was examined as a marker for hepatic sinusoidal capillarization. RESULTS: The serum hyaluronan level was significantly correlated with the hepatic regeneration rate (P < 0. 001). Patients with serum hyaluronan levels below 200 ng mL-1 exhibited a significant correlation between the hepatic regeneration rate and the hepatic fibrotic rate. However, patients with serum hyaluronan levels above 200 ng mL-1 did not demonstrate a distinct correlation. The hepatic regeneration rate of patients with FVIIIAg in the liver and serum hyaluronan levels above 200 ng mL-1 were very low compared with those without FVIIIAg (P < 0.001). Multiple regression analysis revealed that serum hyaluronan was a significant predictor of post-operative hepatic regeneration among several clinical variables (r = 0.857, R2 = 0.735). CONCLUSION: It has been suggested that hepatic regeneration is closely related to both hepatic fibrosis and hepatic sinusoidal capillarization. The serum hyaluronan level is regarded as a useful predictor for hepatic regeneration after hepatectomy.

Adult↗

PubMed1999

Differentiation between brewing and non-brewing yeasts using a combination of PCR and RFLP.

In order to differentiate brewing from non-brewing yeasts, a specific polymerase chain reaction (PCR) which targeted the open reading frame of FLO1 was employed. Non-brewing yeasts include 'non-brewing Saccharomyces yeasts' and 'non-Saccharomyces yeasts'. The molecular sizes of the PCR products differed between brewing and non-brewing Saccharomyces yeasts. No FLO1 PCR products were obtained from non-Saccharomyces yeasts. Specific PCR, using oligonucleotide primers that targeted the region between the 5S and 26S rRNA genes, could be used to differentiate brewing yeasts from some non-brewing yeasts. These PCR products were digested with restriction enzymes, Scr FI and Msp I. Different restriction profiles were obtained from brewing and non-brewing yeasts which could not be differentiated using specific PCR of rDNA. These results suggest that it is possible to identify brewing from non-brewing yeasts using specific PCR of FLO1 and rDNA, and detection of restriction fragment polymorphism of rDNA.

Beer↗

PubMed1999

Metastatic lymph-node clearance from head and neck epidermoid carcinomas following radiotherapy.

Although tumor clearance is a common criterion in assessing the impact of radiotherapy (RT), it is not always reliable. Patterns of tumor clearance were determined using 91 metastatic lymph nodes (LNs) from 51 patients with head and neck tumors treated by definitive RT (61-80 Gy) or preoperative RT (43-65 Gy). Clearance rate (CR) was estimated as a daily volume decrement expressed as a ratio to the pre-RT LN volume. CR was greater for the so-called radioresponsive nasopharyngeal subgroups and more poorly differentiated than those of oral cavity and well-differentiated, respectively. Histologically, LNs that were removed following RT consisted mainly of fibrous tissues, necrotic tissues, and few cancer cells. There was no difference in CR between the cancer-cell-positive group (n = 21) and the cancer-cell-negative group (n = 31). Although the CR may reflect inherent radiosensitivity of tumor cells, tumor persistence predicts the amount of oncologically inactive materials rather than that of remaining cancer cells.

Carcinoma, Squamous Cell↗

PubMed1999

Anti-nuclear antibodies in patients with premature ovarian failure.

We examined the prevalence of anti-nuclear antibodies (ANA) in 32 consecutive patients with premature ovarian failure with and without chromosomal abnormalities. Blood samples were taken for karyotype determination as well as detection of autoantibodies, X-terminal microdeletions and spontaneous follicular growth. The correlation between ANA positivity and the age at onset of amenorrhoea, as well as the presence of karyotype abnormalities, X-terminal microdeletions and follicular growth was determined. Ten of the 24 patients with normal karyotype and none of the 8 patients with karyotype abnormalities were ANA positive. ANA were found more frequently in patients with premature ovarian failure with normal karyotypes than in control amenorrhoeic patients (42 versus 6, P < 0.01). ANA were found in 77% (10/13) of premature ovarian failure patients with normal karyotypes who developed amenorrhoea at or under the age of 30 years, but not in the patients who developed amenorrhoea later in life. Follicular growth was evident in 50% (5/10) of karyotypically normal patients with ANA, 71% (10/14) of karyotypically normal patients without ANA and 38% (3/8) of patients with karyotype abnormalities. X-terminal microdeletions were not found in any of the patients studied. These results suggest that patients with premature ovarian failure and ANA are an aetiologically and clinically distinct group.

Adult↗

PubMed1999

Effect of ticlopidine on exercise-induced platelet aggregation and exercise tolerance time in patients with ischemic heart disease.

Platelet aggregation is one of the most important mechanisms for acute myocardial infarction during exercise. We sought to evaluate the effect of ticlopidine (TP) on platelet aggregation (PA) during exercise in patients with ischemic heart disease (IHD). We studied 38 patients with IHD, 26 patients with effort angina pectoris, and 12 patients with a previous myocardial infarction. In protocol I, subjects were divided into two groups. Drugs altering platelet aggregation were withheld 2-4 weeks before the study in 25 patients (control group). TP (200 mg/day) was administered for 7 days in 13 patients (ticlopidine group). A symptom-limited modified Bruce protocol treadmill exercise test was performed. PA was measured at rest and after exercise by using optical densitometry induced by adenosine diphosphate (ADP). PA ratio (percentage of maximum) was compared. In protocol II, in 12 patients, treadmill exercise test and PA measurement were performed with and without TP. PA significantly increased after exercise in control (from 51.7+/-23.3% to 64.4+/-27.7%, p < 0.01) and ticlopidine (from 31.9+/-10.5% to 42.0+/-20.4%, p < .01) groups; however, its grade was lower in the ticlopidine group than in the control group. After exercise, PA was lower in the ticlopidine group than in control group (42.0+/-20.4% vs. 64.4+/-27.7%; p < 0.01). In the same patients, PA was lower with TP than without TP after exercise. Treadmill exercise-tolerance time was greater in the ticlopidine group than in the control group, but not statistically significant (762.3+/-139.2 vs. 711.6+/-169.6 s; NS). Exercise-tolerance time was significantly greater with TP than without TP in same patient (791.7+/-98.9 vs. 733.3+/-152.8 s; p < .05). TP suppressed the increase of PA during exercise and increased the exercise-tolerance time in patients with IHD.

Adenosine Diphosphate↗

PubMed1999

Relation between the serum E-selectin level and the survival rate of patients with resected non-small cell lung cancers.

E-Selectin is an inducible adhesion molecule, which is expressed on cytokine-activated endothelial cells and is thought to interact with cancer cells to initiate metastases. The relationship between serum E-selectin levels and prognoses in 101 patients with resected non-small cell lung cancers (NSCLCs) was studied, and survival curves were compared in relation to E-selectin levels and expression of two carbohydrate antigens, Sialyl Lewisx (SLX) and Sialyl Lewisa (CA19-9), which were immunohistochemically detected in resected specimens in 65 of the 101 cases. The serum E-selectin level on admission was 48.9+/-25.7 ng/ml (mean+/-SD, n=101), and the E-selectin-positive rate was 22.7%, being correlated with the progression of T-factor. The high E-selectin group showed a significantly worse survival rate than the normal E-selectin group. Multivariate analysis confirmed the significant prognostic value of E-selectin. The mean postoperative E-selectin level in 52 cases (36.93 ng/ml) was significantly lower than the preoperative E-selectin level (43.57 ng/ml), indicating that certain NSCLCs might induce the expression of E-selectin. In cases expressing carbohydrate antigens (SLX, CA19-9), the high E-selectin group showed a significantly worse survival curve than the normal E-selectin group. On the other hand, there was no significant difference in the survival curve between the high and normal E-selectin groups when carbohydrate antigens were negative. These results suggest that patients who have high serum E-selectin levels, especially with carbohydrate antigen-positive NSCLC, might be expected to have poor prognoses.

Adult↗

PubMed1999

Spatial and temporal variation of secondary flow during oscillatory flow in model human central airways.

Axial and secondary velocity profiles were measured in a model human central airway to clarify the oscillatory flow structure during high-frequency oscillation. We used a rigid model of human airways consisting of asymmetrical bifurcations up to third generation. Velocities in each branch of the bifurcations were measured by two-color laser-Doppler velocimeter. The secondary velocity magnitudes and the deflection of axial velocity were dependent not only on the branching angle and curvature ratio of each bifurcation, but also strongly depended on the shape of the path generated by the cascade of branches. Secondary flow velocities were higher in the left bronchus than in the right bronchus. This spatial variation of secondary flow was well correlated with differing gas transport rates between the left and right main bronchus.

Bronchi↗

PubMed1999

Clinical, neuropathological, and molecular study in two families with spinocerebellar ataxia type 6 (SCA6).

To clarify the clinical, neuropathological, and molecular characteristics of spinocerebellar ataxia type 6 (SCA6), two unrelated Japanese families with SCA6 were studied. A clinical feature of the two families was late onset "pure" cerebellar ataxia. Pathologically, three SCA6 brains consistently showed Purkinje cell dominant cortical cerebellar degeneration. Morphometric analysis showed that loss of the cerebellar granule cells and inferior olivary neurons were very mild compared with the severity of Purkinje cell loss. There was no obvious ubiquitin immunoreactive nuclear inclusions. All affected patients had identical expanded alleles, and the expansion was also homogeneously distributed throughout the brain without mosaicism. The present study showed that SCA6 is characterised by Purkinje cell dominant cortical cerebellar degeneration, highly stable transmission of the CAG repeat expansion, and lack of ubiquitin immunoreactive nuclear inclusions.

Adult↗