Biomedical subjects

T Kato

Publications and source records attributed to T Kato.

At least 469 records · Page 26Linked to original sources

PubMed2000

Basaloid-squamous carcinoma of the esophagus: report of a case.

We report herein the case of a 69-year-old man with basaloid-squamous carcinoma (BSC) of the esophagus. To the best of our knowledge, this is the 60th case of BSC of the esophagus to be reported in Japan, and a review of the other 59 cases is presented after this case report. In our patient, endoscopic findings revealed a circumferential erosion in the middle intrathoracic esophagus (Im), and a protruding tumor with friable ulceration in the center of the erosion. A biopsy suggested that it was moderately differentiated squamous cell carcinoma (SCC), and a thoracoscopic total thoracic esophagectomy was performed. Histologically, the protruding-type lesion with ulceration was composed of BSC, and the circumferential 0 -I + IIc type lesion was composed of moderately differentiated SCC. The immunohistochemical findings of these resected specimens led us to suspect that the basal-layer-type SCC had transformed into BSC by undergoing differentiation and expansive proliferation.

Aged↗

PubMed2000

Diffusion- and T2-weighted MRI of the transverse pontine fibres in spinocerebellar degeneration.

Because the transverse pontine fibres degenerate in some subtypes of spinocerebellar degeneration (SCD), demonstration of these fibres may be helpful for radiological diagnosis of SCD. Using multishot diffusion-weighted MRI, we attempted to find a way to show the transverse pontine fibres. We assessed the quality of demonstration of these fibres on DWI and of abnormal high signal in the pons and middle cerebellar peduncles on T2-weighted images. We examined evaluated 24 control subjects and 12 patients with SCD: two with sporadic olivopontocerebellar atrophy (OPCA), five with spinocerebellar ataxia type 1 (SCA1), two with SCA3, and three with SCA6. In all control subjects and patients with SCA6, we succeeded in demonstrating the transverse pontine fibres as clear low-signal bundles using DWI. In two patients with SCA3, these fibres were identified less distinctly. In contrast, in two patients with sporadic OPCA and in four of five patients with SCA1, the fibres were not identified. In both patients with sporadic OPCA, abnormal high-signal foci were seen in the base of the pons and middle cerebellar peduncles on T2-weighted images; no such foci were detected in any patient with SCA1, SCA3 or SCA6. DWI seems to be useful for demonstrating transverse pontine fibres. Abnormal high signal in the pons and middle cerebellar peduncles may provide a clue to differentiation of sporadic OPCA from other types of SCD.

Adult↗

PubMed2000

Quantitative assessment of regional myocardial blood flow using oxygen-15-labelled water and positron emission tomography: a multicentre evaluation in Japan.

Recently, a method has been proposed for the quantitative measurement of regional myocardial blood flow (MBF) using oxygen-15-labelled water and positron emission tomography (PET). A multicentre project was organized with the intention of evaluating the accuracy of this method, particularly as a multicentre clinical investigative tool. Each of seven institutions performed PET studies on more than five normal volunteers following a specified protocol. The PET study included a transmission scan, a 15O-carbon monoxide static scan and a 15O-water dynamic scan, thereby yielding MBF values which should have been independent of the spatial resolution of the PET scanner employed. Fifty-three subjects (aged 20-63 years, mean+/-SD 36+/-12 years) were studied at rest, and 31 of these subjects were also studied after dipyridamole in five institutions. Inter-institution consistency and intra-subject variation in MBF values were then evaluated. MBF averaged for all subjects was 0.93+/-0.34 ml min(-1) g(-1) at rest and 3.40+/-1.73 ml min(-1) g(-1) after the administration of dipyridamole, and the flow reserve (defined as the ratio of the two MBF values) was 3.82+/-2.12; these values are consistent with previous reports. Resting MBF values were significantly correlated with the heart rate-blood pressure product (RPP) (y=0.31+6.56E-5x, P<0.010), and RPP was in resting MBF observed in all institutions was well explained by the age-dependent RPP. No significant difference was observed in resting MBF among the institutions. Except in one institution, no significant difference was seen in dipyridamole MBF or myocardial flow reserve. No significant difference was found among the myocardial segments. Regional variation was reasonably small in five institutions, but was not acceptable in two institutions, which was attributed to the scanner performance. These observations suggest that the 15O-water PET technique is useful for a multicentre clinical study if the PET scanner can provide time-activity data with good count statistics.

Coronary Circulation↗

PubMed2000

Primary gastric B cell lymphoma: audit of 82 cases treated with surgery and classified according to the concept of mucosa-associated lymphoid tissue lymphoma.

There has been a trend toward stomach conservation during treatment for primary gastric lymphoma, but surgery ensures accurate pathologic diagnosis through the examination of resected specimens. A histopathologic classification for primary gastric lymphoma had been established with the knowledge that the low grade and high grade components occasionally coexist in a single lesion. Efficacy of this classification as an indicator of biologic behavior and prognosis was evaluated. The classification was performed by reexamining surgically resected specimens from 82 patients with stage IE and IIE gastric lymphoma. Clinical characteristics of the low grade and high grade lymphomas were then evaluated and the survival data analyzed. Despite the larger tumor diameter, the depth of invasion for the low grade type was mostly submucosal, and none had serosal invasion. In contrast, 50% of the high grade type had serosal involvement and were also found to have a higher incidence of node metastasis. Prognosis of the low grade type, a 10-year survival rate exceeding 90%, was significantly better than that of the high grade type. Multivariate analysis revealed that curability of the operation followed by the histopathologic grade were significant independent prognostic factors. Some characteristics of the low grade lymphoma were not consistent with what has been reported in the studies involving stomach-conserving strategies. Investigators are advised to note that the histopathologic grade determined with biopsy specimens alone could be misleading.

Adult↗

PubMed2000

Pathologic evaluation of surgical margins and local recurrences after breast-conserving surgery without irradiation.

This study was undertaken to evaluate the status of margins of the excised breast tissue using our own method. We also determined the indications for breast-conserving surgery without irradiation by examining the characteristics of patients with local recurrence and comparing relapse-free survival (RFS) and overall survival (OS) of patients who underwent wide excision without irradiation with those of 267 patients who underwent total mastectomy. Eighty-two patients with a 3 cm diameter or less invasive carcinoma were treated with wide excision and axillary dissection between 1987 and 1996. Patients who histologically had four or more axillary lymph node metastases, positive pathologic margins, or a high degree of in situ ductal carcinoma around the main tumor in consecutive step-sections were excluded from this study. During a median follow-up of 6 years (range 2-11 years), six patients (7.3%) had local recurrence and five (6.0%) had regional or distant recurrences as their site of first failure. At 11 years the life-table values for RFS and OS for the wide excision-treated group were 84.7% and 92.1%, respectively, compared with 85.0% and 90.0%, respectively, for patients treated by total mastectomy. RFS and OS were similar in the two treatment groups. Results in the present study indicate that if the patients treated by breast-conserving surgery are carefully selected and there are no foci in the pathologic margins, there is a low degree of in situ ductal carcinoma around the tumor, and no multicentricity, it might be unnecessary to administer

Adult↗

PubMed2000

Thrombotic thrombocytopenia purpura caused by piperacillin successfully treated with plasma infusion.

An 81-year-old man was admitted to the hospital with a fever and loss of appetite. After treatment with piperacillin sodium (PIPC), the patient exhibited thrombocytopenia, hemorrhagic colitis, and drug-induced skin eruption. On the fifth day after PIPC induction, he further experienced neurological abnormalities, such as disorientation and confusion, renal dysfunction, and microangiopathic hemolytic anemia (MAHA). The patient was diagnosed with thrombotic thrombocytopenic purpura (TTP) on the basis of thrombocytopenia, MAHA, renal dysfunction, fever, and neurological abnormalities. Infusion of fresh-frozen plasma was initiated for treatment. His condition improved markedly after this treatment. It is rare for TTP to be accompanied with hemorrhagic colitis and skin eruption. These symptoms were induced by PIPC and were successfully treated with plasma infusion.

Aged↗

PubMed2000

Synovial inflammation and hyperplasia induced by gliostatin/platelet-derived endothelial cell growth factor in rabbit knees.

Neovascularization, proliferation of synovial cells, and mononuclear cell influx and activation are characteristic events observed in synovial joints in the pathohistology of rheumatoid arthritis (RA). The objective of this study was to examine synovial inflammation in rabbit knees induced by intra-articular administration of human gliostatin/platelet-derived endothelial cell growth factor (GLS/PD-ECGF), which shares a high degree of chemical homology with thymidine phosphorylase (dThdPase) and is known to have angiogenic activity. Purified recombinant human gliostatin (rHuGLS) and its mutant protein, which was prepared by site-directed mutagenesis and which lacks dThdPase activity, were administered at various doses to rabbit knee joints. The effects of rHuGLS and the mutant were examined histologically. Intra-articular injection of rHuGLS resulted in the development of diffuse synovitis resembling RA. The mutant protein also brought about the same effect. These findings suggest that human GLS can cause RA-like synovitis in rabbit knee joints via a mechanism other than its dThdPase activity.

Animals↗

PubMed2000

Basic FGF-induced activation of telomerase in rheumatoid synoviocytes.

To investigate the mechanism of persistent proliferation of rheumatoid arthritis (RA) synoviocytes in situ, we examined the activity of telomerase enzyme and the expression of telomerase related factors in cultured synoviocytes. Cultured synoviocytes obtained from patients with rheumatoid arthritis (n = 29), osteoarthritis (OA, n = 18), and traumatic joint disease (TJD, n = 4) were examined. Telomerase activity was detected by TRAP (telomeric repeat amplification protocol) assay, and 12 out of 29 samples of synoviocytes (41%) from RA patients showed a positive telomerase activity, whereas none of the samples from OA and TJD patients showed this activity. Results were confirmed by PCR-ELISA. The telomerase activity was enhanced by basic fibroblast growth factor (bFGF). The mRNA expression of telomerase related factors, such as hTERC, TRF2, and TEP-1, showed no difference between RA and OA synoviocytes. Our results suggest that telomerase is activated in rheumatoid synoviocytes, and that bFGF upregulates the activity of this enzyme in RA synoviocytes.

Arthritis, Rheumatoid↗

PubMed2000

Biliary atresia with hyperandrogenic amenorrhea: case report.

The etiology of hyperandrogenic amenorrhea in a 16 year-old girl after a successful Kasai operation for biliary atresia was unclear. Delayed puberty and menarche were observed. There was no luteinizing hormone-follicular stimulating hormone surge. A provocative luteinizing hormone-releasing hormone test showed a normal response. Peripheral aromatization of androgens appeared to function normally. However, plasma levels of sex hormone-binding globulin and total testosterone were high and the free testosterone level was normal. The anovulatory menstrual cycle continued after menarche at 18 years of age. A combination of estrogen and progesterone therapy was effective. The etiology might be associated with delayed metabolic clearance of testosterone accompanied by the compensatory cirrhosis and portosystemic shunt.

Adolescent↗

PubMed2000

The role of lymphotoxin in pathogenesis of polymyositis.

Polymyositis (PM) is a cell-mediated autoimmune disease. Perforin (PF), Fas ligand (FasL) and TNF-alpha are considered to be important factors in cytotoxic T lymphocyte-mediated cell injury, and several studies have established a role of lymphotoxin (LT) in T helper type 1 (Th1)-induced cell-mediated autoimmune diseases. In the present study, to determine how LT, PF and FasL are involved in the pathogenesis of PM, we used immunohistochemical staining (IHC), reverse transcription polymerase chain reaction (RT-PCR), and in situ hybridization (ISH) on muscle specimens from patients with PM, amyotrophic lateral sclerosis (ALS), myotonic dystrophy (MyD) and controls (NC). There were many mononuclear cells (MNCs) immunoreactive for LT and some for PF and FasL within the fasciculus in PM muscles. On the other hand, only few or no LT-, PF- and FasL-positive cells were detected in MyD, ALS and NC muscles. The results of mRNA expression of these three molecules with RT-PCR were consistent with those using IHC methods. The number of MNCs positive for LT with ISH was far higher in PM compared to MyD, ALS and NC (P < 0.05 or 0.01). The MNCs located in the connective tissue or in the vicinity of necrotizing or non-necrotizing muscles were mainly LT mRNA and CD4 positive, while MNCs invading the non-necrotic fibers were mainly LT mRNA and CD8 positive. Our results indicated that the expression of LT was up-regulated in PM, and LT plays an important role in muscle injury and orchestrating the inflammatory reaction in PM.

Aged↗

PubMed2000

Frontal lobe membrane phospholipid metabolism and ventricle to brain ratio in schizophrenia: preliminary 31P-MRS and CT studies.

A number of studies employing in vivo phosphorous-31 magnetic resonance spectroscopy (31P-MRS) have demonstrated altered measurements of frontal phospholipid and high energy phosphorus metabolism in schizophrenia. Enlargement of both the cerebroventricular system and the cortical sulci also has been reported as the most consistent pathological finding in schizophrenia by several investigators. To our knowledge, however, only two studies have simultaneously examined structural and functional aspects of the biological substrate of schizophrenia in the same patients. Moreover, they may have failed to find a significant correlation between these variables because of small sample sizes. The possible relationship between frontal lobe membrane phospholipid metabolism and ventricle-to-brain ratio (VBR) in patients with schizophrenia was investigated. In 31 schizophrenic patients, frontal lobe membrane phospholipid metabolism was measured by 31P-MRS, and VBR was measured by computed tomography (CT). Stepwise multiple regression analysis disclosed that VBR positively correlated only with increased phosphodiester (PDE) level (beta = 0.381, p = 0.0345), but with no other metabolites. This finding may provide evidence for an association between structural brain abnormality and altered frontal lobe membrane metabolism in schizophrenic patients, although the p-value of the finding is not high.

Adolescent↗

PubMed2000

Identification of a novel 23kDa protein encoded by putative open reading frame 2 of TT virus (TTV) genotype 1 different from the other genotypes.

We report the entire open reading frames (ORFs) sequences of four TT virus (TTV) isolates, one genotype 2 (G2) and three G4 isolates. Despite a DNA virus, TTV possesses high rate of amino acid (aa) substitution: the aa sequence homology of ORF1 and 2 is lower than the nucleotide homology. The partial 'N22' region of ORF1 is suitable for genotyping of 'prototype TTV' isolates, because the phylogenetic tree from partial 'N22' sequence is consistent with that from the entire ORF1. Based on our sequence data, ORF2 from most isolates excluding G1 encode truncated 49 aa (pORF2a) because of an in-frame stop codon, although ORF2s from most G1 isolates encode 202 aa (pORF2ab). Just downstream the stop codon, another ORF encoding a protein of approximately 150 aa (pORF2b) is found, whose homology is quite low among these genotypes. Our in vitro transcription/translation study supports that all G1a and a part of G b without an in-frame stop codon dominantly encode pORF2ab, a novel 23 kDa protein, whereas the other genotypes with an in-frame stop codon encode pORF2b (17 kDa). Our data indicate TTV G1a and a part of G1b should have different characteristics from the other genotypes.

Amino Acid Sequence↗

PubMed2000

Identification of novel polymorphisms in the AXIN1++ and CDX-2 genes.

Axin and Cdx-2 play important roles in the tumorigenesis of human liver and colon. We have identified seven novel single-nucleotide polymorphisms (SNPs) in the AXIN1 gene and three in the CDX-2 gene. The identification of SNPs in these cancer-associated genes establishes a basis for future investigations to detect losses of heterozygosity in tumors; these SNPs may also provide genetic background information associated with cancer risk.

Alleles↗

PubMed2000