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Biomedical subjects

S Ohno

Publications and source records attributed to S Ohno.

At least 109 records · Page 6Linked to original sources
PubMed2001

Relationship between skeinoid fibers and stromal matrix in gastrointestinal stromal tumors: morphometric analysis with quick-freezing and deep-etching method.

Our previous study of a gastrointestinal autonomic nerve tumor with skeinoid fibers (SF) using the quick-freezing and deep-etching method, suggested that the distance between one radix and a neighboring radix (DRNR) in pre-existing meshwork structures around the tumor cells is consistent with the periodicity of the SF. Therefore, measurement of the DRNR in the meshwork could clarify the significance of the pericellular matrix for SF development. In the present study, we analyzed the meshwork in three cases of gastrointestinal stromal tumor (GIST), which showed different immunohistochemical stainings, but confirmed to have smooth muscle differentiation (SMD) by immunohistochemistry and/or electron microscopy. The DRNR from the three cases of GIST showed similar histogram patterns (a peak of 20-30 nm, mean values of 28.02, 25.74 and 26.45 nm), which were significantly shorter than the periodicity of SF (a peak of 40-45 nm, mean value of 42.14). Although we need further studies with additional GIST cases, we speculate that the pericellular matrix of GIST with SMD is not suitable for SF development.

Abdominal Neoplasms↗
PubMed2001

Infection of TT virus in patients with idiopathic pulmonary fibrosis.

The precipitating factors of idiopathic pulmonary fibrosis (IPF) have not been elucidated. Recently, a novel DNA virus named TTvirus (TTV) was discovered in a patient with post-transfusion hepatitis of unknown aetiology TTV is a circular, single-stranded DNA virus of 3.8 kB. To evaluate the relationship between TTV and IPF, the sera of 33 patients with IPF were tested for the presence of TTV DNA by semi-nested polymerase chain reaction. TTV DNA was detected in 12 (36.4%) IPF patients. The serum lactate dehydrogenase (LDH) level was significantly higher in the IPF patients withTTV than in those without TTV (802 +/- 121 vs. 530 +/- 49 IU l(-1), p < 0.05). Six (50%) of 12 patients in theTTV DNA-positive group died during the observation period, while only six (28.6%) of 21 patients in theTTV DNA-negative group died. The 3-year-survival rate was significantly lower in the TTV DNA-positive group than in theTTV DNA-negative group (58-3% vs. 95.2%, P <0-02). Replicative intermediate forms of TTV DNA were detected in the lung specimen from a TTV-infected IPF patient. TTV infection influences the disease activityand prognosis of IPF in some cases. Further studies are required to elucidate the clinical significance of TTV in IPF.

Acute Disease↗
PubMed2001

Clinical spectrum of epileptic spasms associated with cortical malformation.

The spectrum of clinico-electrical characteristics of epileptic spasms associated with cortical malformation was studied in detail. The subjects were 15 patients suffering from spasms and cortical malformation demonstrated by MRI. The types of cortical malformation causing spasms were various, including hemimegalencephaly, diffuse pachygyria, focal cortical dysplasia, and polymicrogyria. Ohtahara syndrome was diagnosed in 3 patients, and West syndrome in 8. Symptomatic localization-related epilepsy preceded West syndrome in 4 patients, and a transition from Ohtahara syndrome to West syndrome was observed in one. West syndrome was followed by symptomatic generalized epilepsy including Lennox-Gastaut syndrome in 4 patients. Nine patients showed a condition which was labeled "epilepsy with partial seizures and spasms" (EPS) and characterized by the coexistence of partial seizures and spasms, and multifocal epileptic discharges on EEG. Spasms occurred only as EPS in 5 patients. EPS appeared following Ohtahara syndrome or West syndrome in 4 patients, and showed a transition to symptomatic localization-related epilepsy in 4. However, EPS did not evolve into generalized epilepsy, and persisted until the time of last follow-up in 5 patients. Therefore, the clinico-electrical pictures of patients with spasms and cortical malformation were diverse and not always limited within those of typical generalized epilepsy.

Cerebral Cortex↗
PubMed2001

Cytokine production and helper T cell subsets in Vogt-Koyanagi-Harada's disease.

PURPOSE: To investigate helper T (Th) cell subsets and cytokine production in patients with Vogt-Koyanagi-Harada's (VKH) disease. METHODS: Nine patients in the acute stage of VKH disease and 9 healthy controls were studied. Interferon-gamma (IFN-gamma), interleukin-2 (IL-2) and IL-4 mRNA from peripheral blood mononuclear cells (PBMC) was detected by reverse transcriptase-polymerase chain reaction. Cytokine levels in plasma, cerebrospinal fluid (CSF) and PBMC culture supernatant were measured by enzyme-linked immunosorbent assay (ELISA). The proportions of each cytokine-producing CD4+ or CD8+ cells in PBMC cultured with or without anti-CD3 antibody stimulation were analyzed by flow cytometry. RESULTS: We observed a significant increase of cytokine mRNA positive cases of VKH patients in comparison with controls only in IFN-gamma mRNA detection from PBMC. ELISA detected IFN-gamma in CSF from only 1 patient and no cytokine in plasma. The levels of IFN-gamma and IL-2 were significantly higher in the stimulated cell culture supernatant of the patients than those of controls. The proportions of IFN-gamma- or IL-2-producing CD4+ cells were significantly higher in the patients than in controls in both stimulated and unstimulated conditions. However, no significant difference was found in IL-4-producing CD4+ cells. In CD8+ cells, significant difference was found only in IL-2-producing cells in the stimulated condition. CONCLUSIONS: Th cells from VKH patients produced predominantly Th1 cytokines, especially after stimulation in vitro. It is therefore suggested that activated Th cells produce predominantly Th1 cytokines, which then produce pathologic changes.

Adult↗
PubMed2001

Proliferation in the posterior region of the lens of c-maf-/- mice.

PURPOSE: To examine the involvement of the c-maf gene in the proliferation of the lens cells. METHODS: Eyes of the E13 and E18 stages of the wild-type and c-maf-/- mice were analyzed by BrdU incorporation assay, TUNEL assay and immunocytochemistry using a anti-P27(KIP1) and a anti-P57(KIP2) antibody. RESULTS: In the E13 and E18 c-maf mutant lens, BrdU-positive cells were detected at the posterior region of the lens. Cell-cycle inhibitor P27(KIP1) and P57(KIP2) were expressed in the equatorial and posterior region of the lens of both wild-type and c-maf-/- lenses. CONCLUSION: These results suggest that the expression of c-maf is required for differentiation and cell cycle arrest of lens fiber cells. It is also suggested that P27(KIP1) and P57(KIP2) were not involved in the continued proliferation of posterior region of the c-maf-/- lens.

Animals↗
PubMed2001

Changing the amino acid specificity of yeast tyrosyl-tRNA synthetase by genetic engineering.

In an attempt to generate mutant aminoacyl-tRNA synthetases capable of charging non-canonical amino acids, a series of yeast tyrosyl-tRNA synthetase (TyrRS) mutants was constructed by site-specific mutagenesis of putative active site residues, which were deduced by analogy with those of Bacillus stearothermophilus TyrRS. Among these mutants, one with the replacement of tyrosine at position 43 by glycine, "Y43G," was found to be able to utilize several 3-substituted tyrosine analogues as substrates for aminoacylation. The catalytic efficiency (k(cat)/K(m)) of mutant Y43G for aminoacylation with L-tyrosine was about 400-fold decreased as compared to that of the wild-type TyrRS. On the other hand, the ability to utilize 3-iodo-L-tyrosine was newly generated in this mutant TyrRS, since the wild-type TyrRS could not accept 3-iodo-L-tyrosine at all under physiological conditions. This mutant TyrRS should serve as a new tool for site-specific incorporation of non-canonical amino acids, such as those in 3-substituted tyrosine analogues, into proteins in an appropriate translation system in vivo or in vitro.

Amino Acid Sequence↗
PubMed2001

Features of microsatellite instability in colorectal cancer: comparison between colon and rectum.

In one third of colorectal cancer patients, tumours occur in the rectum. Unique aetiologies may underlie the increased carcinogenesis in this region of the colorectum. Microsatellite instability (MSI) was analysed in specimens obtained from 121 colorectal carcinoma patients, using five dinucleotide markers and a new fluorescent system. The incidence of microsatellite alterations in the proximal colon, the distal colon and the rectum was 44.4% (16/36), 37.2% (16/43) and 23.8% (10/42), respectively. Patterns of microsatellite alterations could be classified into two subtypes, one showing relatively small changes within 6 bases (type A) and the other exhibiting drastic changes over 8 bases (type B). All the changes observed in tumours in the rectum were type A, and no type B mutation was noted. There was a close correlation between type B mutations and high-frequency MSI (> or =2 markers), MSI-H, and between type A mutations and low-frequency MSI (1 marker), MSI-L. The type B/MSI-H phenotype significantly correlated with the proximal localisation of tumours. In the rectum, there was no tumour with the type B/MSI-H phenotype. These findings suggest that cancers occurring in the colon and the rectum have a differential molecular background for carcinogenesis.

Adenocarcinoma↗
PubMed2001

delta- and gamma-Sarcoglycan localization in the sarcoplasmic reticulum of skeletal muscle.

Sarcoglycans are transmembrane proteins that are members of the dystrophin complex. Sarcoglycans cluster together to form a complex, which is localized in the cell membrane of skeletal, cardiac, and smooth muscle fibers. However, it is still unclear whether or not sarcoglycans are restricted to the sarcolemma. To address this issue, we examined alpha-, beta-, delta-, and gamma-sarcoglycan expression in femoral skeletal muscle from control and dystrophin-deficient mice and rats using confocal microscopy and immunoelectron microscopy. Confocal microscopy of the tissues in cross-section showed that all sarcoglycans were detected under the sarcolemma in rats and control mice. delta- and gamma-sarcoglycan labeling demonstrated striations in the longitudinal section, suggesting that the proteins were expressed in the sarcoplasmic reticulum (SR) or transverse tubules (T-tubules). Moreover, such striations of both sarcoglycans were recognized in the dystrophin-deficient mouse skeletal muscle. Double labeling with phalloidin or alpha-actinin and delta- or gamma-sarcoglycan showed different labeling patterns, indicating that delta-sarcoglycan localization was distinct from that of gamma-sarcoglycan. Immunoelectron microscopy clarified that delta-sarcoglycan was localized in the terminal cisternae of the SR, while gamma-sarcoglycan was found in the terminal cisternae and longitudinal SR over I-bands but not over A-bands. These data demonstrate that delta- and gamma-sarcoglycans are components of the SR in skeletal muscle, suggesting that both sarcoglycans function independent of the dystrophin complex in the SR.

Actinin↗
PubMed2001

Morphological study of erythrocyte shapes in red pulp of mouse spleens revealed by an in vivo cryotechnique.

The purpose of this study was to clarify erythrocyte shapes in splenic cords of living mouse spleens, using our in vivo cryotechnique followed by scanning (SEM) or transmission (TEM) electron microscopy. Some spleens of mice were quickly frozen by the in vivo cryotechnique while their hearts were beating under anesthesia. In contrast, other spleens were prepared by an in vitro freezing method after they were taken out from the abdominal cavity. They were routinely freeze-substituted, and prepared for SEM and TEM. A few mouse spleens were also routinely fixed and embedded in Quetol-812 to obtain conventional morphology. Erythrocytes in living mouse spleens showed a variety of shapes with narrow spaces between them, trapped among reticular fiber tissues. Similar various shapes of erythrocytes were kept in the red pulp even after blocking normal blood circulation, as prepared by the in vitro freezing method. In comparison to the above-mentioned findings, some erythrocytes were changed to biconcave discoid shapes by the conventional immersion fixation with chemical fixatives. They also showed wide spaces between each other among reticular fiber tissues. Such conventional morphological studies could hardly reveal the in vivo shapes of erythrocytes in functioning spleens with normal blood circulation. In contrast, the various shapes of erythrocytes in the functioning spleens were demonstrated by our in vivo cryotechnique. It is suggested that most erythrocytes congesting in spleens keep their original configuration in spite of microenviromental alteration in splenic blood circulation.

Animals↗
PubMed2001

Intravesicular Fas localization in epithelial cells of castrated rat prostate glands.

Androgenic steroids regulate the development and size of mammalian prostate epithelial cells. To evaluate the relationship between Fas-Fas ligand system and apoptosis in prostate epithelial cells of the castrated rats, we have examined immunocytochemical localization of Fas antigen in the castrated rat prostate glands at a series of different times. We used a rabbit polyclonal anti-Fas antibody with a streptavidin-biotin method and confocal laser scanning method or an immunogold method. Fas immunolocalization was examined in ventral lobes of prostate glands taken from intact or castrated adult male Wistar rats on day 1, 2, 3, 4 and 5 by light or electron microscopy. At a light microscopic level, the castrated prostate epithelial cells showed mostly Fas immunolocalization in their apical parts of cytoplasm on day 2 after the castration. In addition, their extent of the Fas expression was expanded throughout the cytoplasm in proportion to the androgen ablation periods, and later the Fas expression was detected at luminar or basolateral sides of the epithelial cells. Both immunogold labeling with ultrathin sections and immunoperoxidase technique with cryostat sections demonstrated that Fas was localized mainly in secretory granules of the castrated prostate epithelial cells and some parts of their cell membranes at later stages. Our immunocytochemical findings showed that Fas expression was time-dependently induced in most of the prostatic epithelial cells after castration of rats. The rate of Fas-expressing epithelial cells was too high and inconsistent with the previously reported rate of TUNEL-positive ones. The membrane-associated Fas may have little effect on the apoptosis in the present case, bacause a lot of soluble Fas was secreted from the prostatic epithelial cells. A further study is needed to clarify some significance of the secretory Fas in the prostatic epithelium after the rat castration.

Animals↗
PubMed2001

Acute cholestatic hepatitis caused by a probable allergic reaction to paracetamol in an adolescent.

We reported on an adolescent who suffered from cholestatic hepatitis after taking a low dose of paracetamol. It was suspected that the condition was brought about by an allergic reaction to paracetamol. Paracetamol is one of the representative intrinsic hepatotoxic drugs. There have been only a few reports on liver damage due to an allergic reaction to paracetamol. There is a need to call attention to this particular reaction.

Acetaminophen↗
PubMed2001

[Cytomegalovirus antigenemia assay as a useful tool for early diagnosis and therapy for cytomegalovirus infections in three cases with collagen diseases].

We report here three cases of collagen diseases with cytomegalovirus infections. (1) A 21-year-old female, who had been diagnosed as systemic lupus erythematosus, lupus nephritis and lupus peritonitis, had fever. Cytomegalovirus antigenemia (CMV-Ag) assay was 10/8 positive. (2) A 33-year-old female, who had been diagnosed as Wegener glanulomatosis, had fever and liver dysfunction. CMV-Ag assay was 933/896 positive. (3) A 64-year-old female, who had been diagnosed as microscopic polyangitis, had fever, liver dysfunction and pneumonia. CMV-Ag assay was 6/2 positive. They were considered to be complicated with CMV infections. We could make early diagnoses of CMV infection by using CMV-Ag assay and treat them with anti-CMV therapy effectively.

Adult↗
PubMed2001

Proinflammatory cytokines regulate the gene expression of hyaluronic acid synthetase in cultured rabbit synovial membrane cells.

To elucidate the mechanism of accumulation and fragmentation of hyaluronic acid (HA) under inflammatory conditions, we investigated the effect of proinflammatory cytokines on hyaluronic acid synthetase (HAS) mRNA expression using cultured rabbit synovial membrane cells. HASs mRNA levels were determined by real-time PCR. HAS2 mRNA expression was maximally enhanced 3.3- and 2.8-fold after 3-hour stimulation with IL-1beta (1 ng/ml) and after 1-hour stimulation with TNF-alpha (10 ng/ml). HAS3 mRNA expression was increased by a maximum of 4.3 times after 3-hour stimulation with IL-1beta (10 ng/ml), whereas 1-hour stimulation with TNF-alpha (10 ng/ml) and IFN-gamma (10 ng/ml) induced around a 2.5-fold increase in HAS3 mRNA. Although IFN-gamma (1-100 ng/ml) alone showed little effect on HAS2 mRNA expression, the effect was synergized by combined with both IL-1beta and TNF-alpha, substantially increasing HAS2 mRNA expression. These results suggest that proinflammatory cytokines regulate the HAS expression, and consequently may contribute to the accumulation and fragmentation of HA.

Animals↗
PubMed2001

[Induction chemotherapy (cisplatin + vinorelbine) is found to be markedly effective for squamous cell lung carcinoma with sarcoidosis--a case report].

A sixty-one-year-old man was admitted to our hospital because of a right lung tumor shadow. He had been diagnosed as having sarcoidosis at the age of fifty-seven. He was newly diagnosed as having squamous cell carcinoma by trans bronchial biopsy. He was treated with an induction chemotherapy (cisplatin 80 mg/m2 + vinorelbine 20 mg/m2) followed by right middle and lower lobectomy with a mediastinal nodal dissection, because the stage of his carcinoma was cT2N2M0. Resected lung tissue showed the disappearance of cancer cells. Dissected mediastinal and hilar lymph nodes showed many sarcoid granulomas. Cisplatin combined with vinorelbine might be an effective chemotherapy for non-small cell lung carcinoma.

Antineoplastic Agents↗
PubMed2001

[A case of recurrent gastric cancer successfully treated with TS-1].

A patient with recurrent gastric cancer which infiltrated the pelvic muscle after the treatment of paraaortic lymph node and ovarian metastases was successfully managed by a novel oral anticancer drug, TS-1. TS-1 was administered at a dose of 80 mg/day. One course consisted of two repetitions of consecutive administration of TS-1 for 14 days and withdrawal of TS-1 for 14 days. Adverse reactions were mild and the patient did not request hospitalization after two courses had been completed. Subjective symptoms such as difficulty in walking improved after one week and a partial response was obtained after 2 weeks of treatment. At the end of 4 courses we could remove an indwelling pyelocatheter for the ureter stricture. As of 14 months after the beginning of administration of TS-1, the patient is being treated as an outpatient and has attained a better QOL than before.

Aged↗
PubMed2001

New genome type of adenovirus serotype 19 causing nosocomial infections of epidemic keratoconjunctivitis in Japan.

Twelve strains of adenovirus serotype 19, isolated from cases of epidemic keratoconjunctivitis in Japan in 1992, 1993, 1997, and 1998, were analyzed by DNA restriction analysis, using restriction endonucleases BamHI, BglI, BglII, EcoRI, HindIII, KpnI, PstI, SacI, SalI, SmaI, and XhoI. Among these 11 restriction endonucleases, EcoRI, PstI, SacI, and SmaI were discriminative enzymes, showing restriction patterns different from those reported previously for the prototype and the variant 19a. This new genome type was isolated in 1997 and 1998, when an increase of epidemic keratoconjunctivitis cases caused by adenovirus serotype 19 was observed for both sporadic and nosocomial infections. Strains from 1992 and 1993 showed restriction patterns similar to those of the worldwide reported variant 19a for all enzymes used. The changes detected in strains from 1997 and 1998 could be the reason for the recent epidemic.

Adenovirus Infections, Human↗
PubMed2001

[Evaluation of central retinal sensitivity after vitrectomy with removal of choroidal neovascular membrane for age-related macular degeneration].

PURPOSE: To evaluate retinal sensitivity in patients with age-related macular degeneration (AMD) before and after surgery. METHODS: Seven consecutive patients with AMD underwent vitrectomy with removal of choroidal neovascular membrane(CNV). Static microperimetry using a scanning laser ophthalmoscope(SLO) was performed before and after surgery. Central dense scotoma size was measured. RESULTS: Retinal sensitivity improved in all cases. Mean size of the central dense scotoma was decreased by 42%(range 14-62%). CONCLUSION: The results suggest that vitrectomy with removal of CNV can improve the central retinal sensitivity.

Aged↗