PubMed Health⌕ Search

Biomedical subjects

Y Kato

Publications and source records attributed to Y Kato.

At least 325 records · Page 18Linked to original sources
PubMed2000

4 cases of photocontact dermatitis due to ketoprofen.

We report 4 cases of photocontact dermatitis due to ketoprofen, a non-steroidal anti-inflammatory drug derived from propionic acid. We carried out a skin biopsy to examine the amount of ketoprofen in the eruptive skin. We investigated the cross-reactions between tiaprofenic acid, suprofen and ketoprofen by patch and photopatch testing. In case no. 1, 17 days after the discontinuance of Mohrus poultice (containing ketoprofen as an active ingredient), we detected ketoprofen 312.5 ng/g in the area of skin where the poultice was applied. All 4 cases reacted positively to the causative medicaments containing ketoprofen and ketoprofen 1% pet. 3 out of 4 cases reacted positively to tiaprofenic acid 1% pet. Only 1 case out of the ketoprofen and tiaprofenic acid positive cases reacted positively to suprofen 1% pet. Vehicles of patients' medicaments were negative in all 4 cases. We suspected that the key structure of the cross-reaction between ketoprofen and tiaprofenic acid and suprofen was the benzoyl radical.

Adult↗
PubMed2000

Results of patch testing with lavender oil in Japan.

We report the annual results of patch testing with lavender oil for a 9-year period from 1990 to 1998 in Japan. Using Finn Chambers and Scanpor tape, we performed 2-day closed patch testing with lavender oil 20% pet. on the upper back of each patient suspected of having cosmetic contact dermatitis. We compared the frequency of positive patch tests to lavender oil each year with those to other fragrances. We diagnosed contact allergy when patch test reactions were + or <+ at 1 day after removal. The positivity rate of lavender oil was 3.7% (0-13.9%) during the 9-year period from 1990 to 1998. The positivity rate of lavender oil increased suddenly in 1997. Recently, in Japan, there has been a trend for aromatherapy using lavender oil. With this trend, placing dried lavender flowers in pillows, drawers, cabinets, or rooms has become a new fashion. We asked patients who showed a positive reaction to lavender oil about their use of dried lavender flowers. We confirmed the use of dried lavender flowers in 5 cases out of 11 positive cases in 1997 and 8 out of 15 positive cases in 1998. We concluded that the increase in patch test positivity rates to lavender oil in 1997 and 1998 was due to the above fashion, rather than due to fragrances in cosmetic products.

Adolescent↗
PubMed2000

Epithelioid leiomyosarcoma in a non-immunocompromised infant: additional differential diagnosis of pediatric "round cell tumors".

We report an 18-month-old Japanese girl with purely epithelioid leiomyosarcoma presenting as a huge intraabdominal mass. The patient had been well from birth and had shown no signs of immunodeficiency. She was negative for human immunodeficiency virus. Blood examination revealed elevated serum neuron specific enolase (NSE). Histologically, the tumor was comprised of solid growths of round or polygonal cells with vesicular nuclei and often vacuolated cytoplasm rich in glycogen. The tumor cells were positive for vimentin, NSE, and MIC2, and were negative for desmin and neurofilament. The age, clinical presentation, and histologic findings mostly favored Ewing's sarcoma/primitive neuroectodermal tumor. Silver stain, however, demonstrated well-developed reticulin fibers often outlining individual tumor cells. An expanded panel of immunostains showed that the tumor cells were intensely positive for smooth muscle actin, and ultrastructural study revealed abundant fine cytoplasmic filaments with focal subsarcolemmal densities, various amounts of glycogen, and irregularly arranged, thick basal lamina. The diagnosis of epithelioid leiomyosarcoma was made. Following reduction in tumor size by chemotherapy, the serum NSE level was normalized. From the surgical finding, the primary site was presumed to be the urachus or the urinary bladder dome. Although extremely rare, epithelioid leiomyosarcoma should be added in the list of differential diagnoses of pediatric "round cell tumors."

Abdominal Neoplasms↗
PubMed2000

FK506 potently inhibits T cell activation induced TNF-alpha and IL-1beta production in vitro by human peripheral blood mononuclear cells.

The aim of this study was to elucidate the in vitro inhibitory potency of FK506 on production of the inflammatory cytokines, tumour necrosis factor (TNF)-alpha and interleukin (IL)-1beta, with a view to assessing this immunosuppressive agent as a potential anti-rheumatic drug. We employed an in vitro model which produces TNF-alpha and IL-1beta through T cell activation. Human peripheral blood mononuclear cells (PBMC) were cultured with immobilized anti-CD3/CD28 monoclonal antibody in this model. FK506 inhibited anti-CD3/CD28 induced TNF-alpha and IL-1beta production at concentrations less than 1 ng ml(-1). Flow cytometric analysis of intracellular TNF-alpha and IL-1beta positive cells showed that FK506 potently suppresses inflammatory cytokine production from CD14+ monocytes as well as from T cells. Cyclosporin A (CsA) and dexamethasone (DEX) also inhibited the anti-CD3/CD28 induced cytokine production, but were less potent than FK506. FK506 and CsA, but not DEX, specifically inhibited anti-CD3/CD28 induced inflammatory cytokine production without affecting the lipopolysaccaride (LPS) induced effect. Methotrexate (MTX) was completely inactive for suppressing cytokine production under either condition. Anti-CD3/CD28 stimulated PBMC culture supernatants were found to enhance the expression of adhesion molecules in human vascular endothelial cells. FK506, CsA and DEX led to the suppression of adhesion molecule expression probably by inhibiting cytokine production from PBMC. The inhibitory potency of agents on TNF-alpha and IL-1beta production was compared with cytotoxicity and FK506 was not cytotoxic at concentrations several orders of magnitude greater than those required for cytokine inhibition. These results strongly suggest that FK506 may be most effective to specifically prevent T cell activation mediated inflammatory cytokine production in a clinical setting.

Antibodies↗
PubMed2000

Molecular and electrical heterogeneity of circulating human erythropoietin measured by sensitive enzyme immunoassay.

BACKGROUND: We set up a sensitive sandwich enzyme immunoassay (EIA) of human erythropoietin (EPO) and further investigated molecular weight and structural heterogeneity, and electrical heterogeneity of the circulating EPO in normal human plasma without any concentrating procedure. MATERIALS AND METHODS: We set up a sensitive sandwich EIA of EPO using anti-EPO rabbit Fab'-peroxidase conjugate and anti-EPO IgG coated polystyrene balls. Standard EPO and plasma samples obtained from three normal subjects were applied to gel chromatographic analysis. Plasma samples obtained from three normal subjects were subjected to preparative isoelectric focusing with a column (pH 3.5-10). RESULTS: The minimal detectable quantity was 0. 15 mIU mL-1 using 100 microL sample. There was a good parallelism between diluted human plasma samples and the standard EPO in the assay. Rat plasma EPO was cross-reacted in the assay. There was a good correlation between EPO levels determined by the EIA and those of radioimmunoassay (y = 0.897x + 0.564, r = 0.957). Gel chromatographic analysis of standard EPO revealed a single peak. On the other hand, gel chromatographic analysis of unconcentrated plasma samples obtained from three normal subjects revealed at least four components of immunoreactive EPO. Preparative isoelectrical focusing revealed at least four major components and some other small peaks in normal human plasma samples. CONCLUSION: These findings indicate the first evidence for molecular and electrical heterogeneity of circulating EPO in normal human plasma without any concentrating procedure.

Animals↗
PubMed2000

Diagnostic criteria for gastrointestinal carcinomas in Japan and Western countries: proposal for a new classification system of gastrointestinal epithelial neoplasia.

BACKGROUND: Large differences have been found between Western and Japanese pathologists in their diagnosis of adenoma/dysplasia and early carcinoma for gastric, colorectal and oesophageal epithelial neoplastic lesions. Common worldwide terminology based on clinical usefulness, that is, on neoplastic severity and depth of invasion, is needed. METHODS: Thirty-one pathologists from 12 countries reviewed 35 gastric, 20 colorectal and 21 oesophageal biopsy and resection specimens. The extent of diagnostic agreement between those with Western and Japanese viewpoints was assessed by kappa statistics. RESULTS: Suspected or definite carcinoma was diagnosed in 17-66% 'of gastric, in 5-40% of colorectal, and in 10-67% of oesophageal slides by pathologists with a Western viewpoint, but in 77-94% of gastric, in 45-75% of colorectal and in 81-100% of oesophageal slides by pathologists with a Japanese viewpoint (from Japan, Germany, Austria and UK). Overall, there was poor agreement between the conventional Western and Japanese diagnoses (kappa values lower than 0.3 for gastric, colorectal and oesophageal lesions). There was much better agreement among the pathologists (kappa values higher than 0.5 for gastric and colorectal lesions) when the original assessments of the slides were regrouped into the five categories of the following classification of GI epithelial neoplasia we hereby propose: C1, negative for neoplasia; C2, indefinite for neoplasia; C3, mucosal low-grade neoplasia (low-grade adenoma/dysplasia); C4, mucosal high-grade neoplasia (high-grade adenoma/dysplasia plus mucosal carcinoma); C5, submucosal invasion of neoplasia. CONCLUSIONS: The intercountry differences in the diagnoses of adenoma/dysplasia and early carcinoma can, in large part, be resolved by adopting terminology based on neoplastic severity and depth of invasion. Problems with defining intramucosal invasion are thus avoided. Moreover, grouping high-grade adenoma/dysplasia and mucosal carcinoma together in one category is clinically useful, as patients with small mucosal neoplastic lesions can be cured by endoscopic local resection.

Adenoma↗
PubMed2000

Dynamic ultrastructure of mouse pulmonary alveoli revealed by an in vivo cryotechnique in combination with freeze-substitution.

A morphological approach to cell dynamics is usually difficult, since routine preparative techniques for electron microscopy always induce artifacts due to cessation of the blood supply into organs. An in vivo cryotechnique followed by the freeze-substitution method probably reduces such problems. It was applied for examining the pulmonary alveoli of BALB/c mice in vivo. The following ultrastructural features were revealed. (1) A surfactant layer provided a continuous covering to the alveolar epithelium. (2) Pleural epithelial cells, alveolar cells and endothelial cells contained many small vesicles and pits. In the alveolar epithelium, they were often localised near microtubules. (3) Typical lamellar structures in large alveolar epithelial cells were rarely detected. (4) Circulating erythrocytes with various shapes were observed in branching blood capillaries. (5) A close association between erythrocytes and the endothelium was seen at the peripheral alveolar septum. Such ultrastructural arrangements may be appropriate for the physiological functions of the pulmonary alveoli, such as exchanges of gases or materials in vivo.

Animals↗
PubMed2000

Origin of giant cells in osteoclast-like giant cell tumors of the pancreas.

To clarify the origin of giant cells in osteoclast-like giant cell tumors (OGCTs) of the pancreas, we performed microscopical, immunohistochemical, and K-ras gene mutation analyses with a microdissection approach in 3 cases, featuring 4 cellular components (osteoclast-like giant cells [OGCs], pleomorphic large cells [PLCs], mononuclear cells, and ductal carcinoma cells). Two cases had abundant OGCs, and 1 case contained large number of both OGCs and PLCs. In each, none of the microdissected OGCs contained any K-ras gene mutation while they were positive for a histiocytic marker (CD-68). In contrast, PLCs, when present, frequently harbored K-ras gene mutations and were negative for CD-68. In all cases, mononuclear cells, a mixture of histiocyte-like and atypical, from microscopic and immunohistochemical viewpoints, also frequently showed K-ras alteration. Histiocyte-like mononuclear cell was equipped with a regular and oval nucleus similar to those in OGCs and was positive for CD-68. Atypical mononuclear cell showed an irregular, pleomorphic, or sometimes bizarre nucleus similar to those in PLCs and was negative for CD-68. All of the K-ras gene mutations found in PLCs and mononuclear cells were the same as in the ductal carcinoma cells within the same tumor. Thus, OGCs differ in origin from ductal cells and are strongly suggested to be nonneoplastic and of mesenchymal origin, whereas PLCs, which harbor K-ras gene mutations, are neoplastic and presumably derived from ductal carcinoma cells. Moreover, mononuclear cells may be classified into 2 types, histiocyte-like and atypical.

Carcinoma, Pancreatic Ductal↗
PubMed2000

K-ras gene mutations and loss of heterozygosity at the p53 gene locus relative to histological characteristics of mucin-producing tumors of the pancreas.

Mucin-producing tumors (MPTs) of the pancreas accompanied by carcinomas usually include various grades of dysplasia in the ductal epithelium, and invasive areas are histologically similar to those of common invasive ductal carcinomas, suggesting that MPTs provide a good tool to investigate early stages of pancreatic carcinogenesis. Thus, to clarify genetic alterations in the early stage of pancreatic carcinogenesis, we analyzed K-ras gene mutations and loss of heterozygosity (LOH) at the p53 gene locus using 37 cases of MPTs harboring dysplastic epithelium. Further, we conducted an extended, multifocal microdissection analysis focusing on the histological features of ductal epithelium and the distribution of genetic alterations for 3 cases of MPT positive for LOH of the p53 gene to determine the relation to tumor progression. K-ras gene mutations were detected with high frequency in 50% or more cases of the adenomas (14 of 19), borderline tumors (4 of 7), and carcinomas (8 of 11), whereas LOH of the p53 gene was limited to carcinomas (3 of 5 informative cases, 60%) and always accompanied by K-ras gene mutation. Investigation of a total of 126 microdissection sites from 3 cases showed the presence of K-ras gene mutations in mild dysplasia and all (100%) regions of moderate or more marked dysplasia, whereas LOH of the p53 gene showed more gradual tendency to increase with grade from moderate dysplasia. In addition, the multifocal genetic analysis showed K-ras gene mutations to be widely distributed throughout tumors, whereas LOH of the p53 gene was localized to 1 or a few areas. Further, topographically delimited areas with the same histology in the same tumor did not always show the same genetic alteration. In conclusion, we could confirm that both the K-ras and p53 gene alterations occur in the intraductal stage of MPT, and the latter is superimposed on the former during the course of tumor progression. However, the pattern of association of histological features with genetic alteration differs from tumor to tumor.

Adult↗
PubMed2000

Strategy for the treatment of arteriovenous malformations.

The treatment of arteriovenous malformations (AVMs) is still a challenging problem in the neurosurgical field. The deep-seated AVMs are a definite indication for radiosurgery for the small AVMs and with pre-embolisation for the large AVMs. The superficial AVMs are a good indication for surgery. In the case of small AVMs, surgery alone is a viable option; however, in the case of large AVMs, pre-operative embolisation is essential for prevention of NPPB (normal perfusion pressure breakthrough). Embolisation alone cannot be used, except for a small AVM in the non-eloquent cortex. Preoperative embolisation makes surgery easy; however, it causes the surrounding cortex to infarct. Hyperperfusion may occur after the direct removal of high-flow large AVMs, therefore postoperative management will be difficult in these cases. In eloquent cortex minimally invasive surgery is more reliable with respect to the morbidity produced. Therefore in cases of small AVMs in the functional cortex, direct surgery is the only choice. In cases of high-flow large AVMs, surgery and postoperative management are risky because of NPPB. Therefore pre-operative embolisation followed by surgery is a better choice. In high-flow AVMs, local blood circulation is not decreased by temporary clipping of the feeding arteries. So we recommend temporary clipping of all feeding arteries, even away from the nidus where it is easier to control bleeding.

Adolescent↗
PubMed2000

Endoscope-assisted microsurgery for cerebral aneurysms.

We performed endoscope-assisted microsurgery for 64 patients with cerebral aneurysms from June 1998 to January 1999. Two patients were treated under picture-in-picture imaging using a surgical microscope connected with an endoscopic-image display system. The study included 34 patients with incidental discovery: 3 IC oph, aneurysm, 1 from cavernous (C3) portion, 8 at ICPC, 1 from infundibular dilatation, 2 at IC bifurcation, 6 at AcoA, 1 at A1A2, 8 at MCA, 1 at P1, 1 from basilar tip, 1 at AICA, 1 at VA and 1 from PICA. The study also included 30 patients with subarachnoid hemorrhage: 5 ICPC, 2 from anterior choroidal, 1 from IC infundibular dilatation, 10 from AcoA, 2 from A2A3, 7 from MCA, 2 from basilar tip and 1 from PICA. They were classified into gr. 1 for 2, gr. 2 for 8, gr. 3 for 10, gr. 4 for 7, and gr. 5 for 3 cases.

Carotid Artery Diseases↗
PubMed2000

Unrecognizable intramucosal spread of diffuse-type mucosal gastric carcinomas of less than 20 mm in size.

BACKGROUND: Diffuse-type intramucosal gastric carcinomas sometimes spread within the mucosa beyond their macroscopic margins, often causing positive resection margins upon local resections such as endoscopic mucosal resection. PATIENTS AND METHODS: A consecutive series of 34 patients with solitary, small (less than 20 mm in diameter macroscopically), and macroscopically well demarcated diffuse-type mucosal carcinomas, who were treated with gastrectomy followed by detailed pathological examination, were included in the present study. Unrecognizable intramucosal spread is defined as an area of cancer which is indistinguishable macroscopically from its peripheral noncancerous area, and covered by normal epithelium with neither morphologic nor color changes. We examined the extent of unrecognizable intramucosal spread, measuring the maximum distances between macroscopic and microscopic margins on the sections, and investigated its relationship with four factors: location of the lesion, macroscopic size, histologic ulcer formation, and degree of atrophy of the background mucosa. RESULTS: The maximum distance between macroscopic and microscopic margins was significantly larger (maximum 10 mm) in the background mucosas with marked atrophy than in those with little or no atrophy. No other factors, including location, macroscopic size and ulcer formation, correlated with it. CONCLUSION: We should pay particular attention to unrecognizable intramucosal spread, especially in markedly atrophied mucosa, when treating small diffuse-type mucosal gastric cancer by local resections such as endoscopic mucosal resection. In addition, because of unrecognizable intramucosal spread, a surgical incision margin of at least 10 mm from the macroscopic margin is indicated.

Adult↗
PubMed2000

Critical role of nitric oxide in expression of porcine LH receptor at transcription and post-transcription levels.

The present study was performed to clarify the involvement of nitric oxide (NO) in the expression of LH receptor in porcine granulosa cells. The granulosa cells, prepared from porcine ovarian follicles, were developed in the presence of FSH. LH receptor mRNA was induced to reach a maximal level after a 24-h culture with FSH, as determined by semi-quantitative reverse transcriptase-PCR (RT-PCR). In our previous report (Nishida et al., 2000), we found that NO was released from granulosa cells after a 40-48 h culture with FSH. When 200 microM NO scavenger was added to cultures before the NO release (30 h), the content of LH receptor on the cells decreased to 28% that of the control. However, the receptor content was not influenced by addition of NO scavenger at 46 h, or by 50 microM NO donor at 30 or 46 h. During transformation of mature granulosa cells to luteal cells, LH receptor mRNA was induced after a 24-h culture with LH, which induction was inhibited by removal of endogenous NO. However, the expression was not influenced by addition of either NO scavenger at 46 h or by NO donor. During the period of these treatments, cellular DNA contents were constant. Consequently, the transient generation of NO may play a critical role in expression of the LH receptor at transcription and post-transcription levels.

Animals↗
PubMed2000

Neurosurgery at Fujita Health University, Japan.

Neurosurgery at the Fujita Health University began in 1972 with Dr. Tetsuo Kanno. In 1973, he was joined by Dr. Kazuhiro Katada and in the year 1976, an independent neurosurgery department was established with Dr. Kanno as the Chief of Neurosurgery. Under his guidance the department continued to grow and by 1978, a neurosurgical residency program recognised by the Japanese Board of Neurosurgery was established. Integration of laboratory research and clinical experience is the hallmark of this program. The current philosophy is directed towards subspecialization and academic training. This article provides a brief overview of the rapid development of a Neurosurgical Centre to reach international acclaim under the guidance of Prof. Tetsuo Kanno.

Hospitals, University↗
PubMed2000

Isolated heterotopic pancreas causing intussusception.

Pediatric intussusception is usually idiopathic in origin, and a pathological lesion at the leadpoint is identified in only a small proportion of cases. Meckel's diverticulum is the most common location when such a lesion is found. Heterotopic pancreas has been seen most frequently in the stomach or duodenum; however, ileal lesions are rare. In the ileum, heterotopic pancreas is usually associated with Meckel's diverticulum and may cause intestinal obstruction by intussusception. However, isolated heterotopic pancreas in the ileum is distinctly rare and usually discovered incidentally during surgery for other conditions. In a review of English language literature, there were only a few pediatric cases of isolated ileal heterotopic pancreas causing intussusception. We report three additional pediatric cases and discuss the clinical significance of this unexpected rare entity.

Choristoma↗
PubMed2000

Chemokines induce eosinophil degranulation through CCR-3.

BACKGROUND: Such CC chemokines as eotaxin and RANTES induce preferential eosinophil recruitment in allergic inflammation. They also elicit proinflammatory effector functions of eosinophils, such as enhanced adhesion and superoxide generation. Eosinophil degranulation by chemokines, however, has not been studied in detail. OBJECTIVE: The purpose of this study was to identify chemokines and their corresponding receptors that induce eosinophil degranulation by using a panel of chemokines and blocking antibodies to candidate receptors. METHODS: Highly purified eosinophils were preloaded with Fura-2 and stimulated with a panel of chemokine ligands for 14 known chemokine receptors: CCR1 to CCR8, CXCR1 to CXCR4, CX3CR1, and XCR1. Calcium influx was measured with fluorescence spectrometry. Eosinophils were also stimulated with the chemokines in the presence or absence of IL-5, and levels of eosinophil-derived neurotoxin were measured in the supernatant with RIA. Specific antibodies to chemokine receptors were used to block degranulation. RESULTS: Calcium influx was induced by monocyte chemotactic protein (MCP) 1, MCP-3, MCP-4, RANTES, eotaxin, IL-8, and stromal cell-derived factor 1alpha, which are chemokines that bind several chemokine receptors. However, degranulation was induced only by CCR3 ligands, including MCP-3, MCP-4, RANTES, and eotaxin. Priming of eosinophils with IL-5 enhanced CCR3 ligand-induced degranulation but did not cause non-CCR3 ligands to induce eosinophil-derived neurotoxin release. An antibody against CCR3 significantly inhibited degranulation induced by CCR3 ligands, eotaxin, or RANTES. CONCLUSION: These results suggest that chemokine-induced eosinophil degranulation, a major effector of eosinophil functions, is mediated through only CCR3, although some non-CCR3 ligands induce calcium influx in eosinophils. CCR3 may be an important target in the treatment of eosinophilic inflammation.

Calcium↗
PubMed2000

The effects of high magnitude cyclic tensile load on cartilage matrix metabolism in cultured chondrocytes.

Excessive mechanical load is thought to be responsible for the onset of osteoarthrosis (OA), but the mechanisms of cartilage destruction caused by mechanical loads remain unknown. In this study we applied a high magnitude cyclic tensile load to cultured chondrocytes using a Flexercell strain unit, which produces a change in cell morphology from a polygonal to spindle-like shape, and examined the protein level of cartilage matrixes and the gene expression of matrix metalloproteinases (MMPs), tissue inhibitors of matrix metalloproteinases (TIMPs) and proinflammatory cytokines such as IL-1beta and TNF-alpha. Toluidine blue staining, type II collagen immunostaining, and an assay of the incorporation of [35S]sulfate into proteoglycans revealed a decrease in the level of cartilage-specific matrixes in chondrocyte cultures subjected to high magnitude cyclic tensile load. PCR-Southern blot analysis showed that the high magnitude cyclic tensile load increased the mRNA level of MMP-1, MMP-3, MMP-9, IL-1beta, TNF-alpha and TIMP-1 in the cultured chondrocytes, while the mRNA level of MMP-2 and TIMP-2 was unchanged. Moreover, the induction of MMP-1, MMP-3 and MMP-9 mRNA expression was observed in the presence of cycloheximide, an inhibitor of protein synthesis. These findings suggest that excessive mechanical load directly changes the metabolism of cartilage by reducing the matrix components and causing a quantitative imbalance between MMPs and TIMPs.

Animals↗