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Y Ohta

Publications and source records attributed to Y Ohta.

At least 1,207 records · Page 67Linked to original sources
PubMedDate not supplied

Immunohistochemical localization of proliferating cells and epidermal growth factor receptors in mouse olfactory epithelium.

We investigated age-related changes in proliferating cells and epidermal growth factor receptors (EGFRs) in mouse olfactory epithelium using an immunohistochemical method with the antiproliferating cell nuclear antigen (PCNA) antibody and the antihuman EGFRs antibody. Many PCNA-positive cells occurred in the surface and basal layers of the olfactory epithelium in the embryonal and neonatal mice. However, only some PCNA-positive cells occurred in the basal layer of adult mice, and only a few presented in the basal layer of aged mice. EGFRs were observed in all layers of the olfactory epithelium at the embryonal and neonatal stages, but were not identified in the olfactory epithelium at the adult or aged stages. We believe that a decrease in EGFRs in the olfactory epithelium induces the inhibition of cell proliferation, with the resultant atrophy of the olfactory epithelium.

Age Factors↗
PubMedDate not supplied

Enhanced thrombolysis induced by argatroban or activated protein C in the presence or absence of staphylokinase, measured in an in vivo animal model using mesenteric arterioles.

Successful administration of thrombolytic agents is associated with vessel reocclusion in a high proportion of cases. We have previously established an animal model to investigate platelet-rich thrombolytic mechanisms in vivo and demonstrated that recombinant staphylokinase (rSAK)-induced thrombolysis was enhanced by the concomitant administration of the direct thrombin inhibitor argatroban. The present study expanded the use of this model by comparing arterial and venous thrombolysis using advanced image analysis software. Mural thrombi were formed by Helium-Neon laser irradiation in mesenteric arterioles and were shown to be lysed, dose-dependently, by smaller amounts of rSAK than those required in venules. Activated protein C (APC), as well as argatroban, enhanced the rSAK-induced thrombolysis. APC or argatroban also induced thrombolysis in the absence of rSAK, and the effect was inhibited by tranexamic acid. The enhanced thrombolysis induced by APC or argatroban in the presence or absence of rSAK may be due to increased endogenous thrombolysis mediated by the inhibition of thrombin activity or delayed thrombin generation.

Animals↗
PubMedDate not supplied

Pretreatment of crude pancreatic islets with mitomycin C (MMC) prolongs islet graft survival in a xenogeneic rat-to-mouse model.

In this study, we examined the effect of mitomycin C (MMC) treatment on graft survival and evaluated its efficacy in immunomodulation of islet graft for transplantation. Male WS rats were used as islet donors and streptozotocin-induced diabetic C57BL/6 mice as recipients. The isolated islets were treated with MMC at concentrations of 0, 0.1, 1, 3.2, 10, 32, 100, 320, and 1000 microg/mL for 30 min, and were cultured for 20 h. Then, 300-400 islets were transplanted into the renal subcapsular space of diabetic mice. Significant prolongation of graft survival was obtained when the islets were treated with MMC at a concentration of 10, 32, or 100 microg/mL (MST 23 +/- 7.4, 17.5 +/- 5.4, 29.6 +/- 9.7 days: p < 0.003, p < 0.012, p < 0.001, respectively, vs. 12.3 +/- 2.7 days for culturing alone). Islets treated with MMC at a concentration of 320 microg/mL or more failed to restore normoglycemia in the diabetic recipient mice after transplantation. Viability of islets incubated with doses up to 100 microg/mL, assessed under the confocal microscope after propidium iodide and Hoechst 33342 staining, was maintained well comparable to that of freshly isolated islets, while those treated at 320 microg/mL was significantly decreased. Thus, a therapeutic window for MMC efficacy was found at concentrations from 10 microg/mL to 100 microg/mL. This modality is simple and effective and underlying molecular mechanisms need to be determined in the future.

Animals↗
PubMedDate not supplied

Diagnostic value of plasma vascular endothelial growth factor as a tumor marker in patients with non-small cell lung cancer.

We assessed the diagnostic value of circulating VEGF as a tumor marker in patients with lung cancer and compared its clinical utility with that of other markers such as carcinoembryonic antigen (CEA) and cytokeratin 19 (CYFRA). One hundred and sixty non-small cell lung cancer patients and 70 healthy volunteers were included in the study. Circulating VEGF was assessed by enzyme-linked immunosorbent assay (ELISA). The serum concentrations of both CEA and CYFRA were measured by means of immunoradiometric assays. The diagnostic value of plasma VEGF (VEGFp) was better than that of CYFRA and similar to that of CEA. When the diagnostic value of VEGFp and CEA for the diagnosis of adenocarcinoma was compared, the two markers proved to have nearly equal discriminatory power. In diagnosing squamous cell carcinoma, VEGFp showed less discrimination than CYFRA. When the diagnostic value of VEGFp was analyzed for stage I adenocarcinoma patients, VEGFp was slightly more discriminatory than CEA. The combination assay of VEGFp and CEA had a sensitivity of 75% and a specificity of 60% at a cutoff of 104.4 pg/mL for VEGFp and 5.2 ng/mL for CEA. The combination of VEGF and CEA was superior to CEA alone in the early diagnosis of adenocarcinoma of the lung.

Adult↗
PubMedDate not supplied

Radioprotective and radiosensitizing effects of sulfur-containing amino acid derivatives on mice.

Both protection and sensitization of Mice C57Bl against 60Co gamma-rays by sulfur-containing amino acid derivatives--S-alkyl-L-cysteines, S-alkyl-2-methyl-DL-cysteines and their hydantoin derivatives, and sulfoxides of these compounds--were examined. DL-5 Allylthiomethyl-5-methylhydantoin (150 mg/kg body weight) had a remarkable radioprotective effect. The survival ratio was 4.3 or above two times as much as that of L-cysteine. On the other hand, its sulfoxide had a radiosensitizing effects; survival ratio, 0.333.

Amino Acids↗
PubMedDate not supplied

Serological and structural comparison of immunodeficiency viruses from man, African green monkey, rhesus monkey and sooty mangabey.

We have studied the serological relationship among the human immunodeficiency virus type 1 (HIV-1), and three simian immunodeficiency viruses (SIV). SIVagm was isolated from African green monkeys (Cercopithecus aethiops), and compared with the previously described isolates of SIVmac from a rhesus macaque (Macaca mulatta) and SIVsm from a sooty mangabey (Cercocebus atys). With respect to the glycoproteins, the simian viruses represent a subgroup apparently different from HIV. To classify HIV and SIV isolates further, we compared tryptic peptide maps of the core polypeptides p 18 and p 24 of HIV-2, three HIV-1 and five SIV isolates. Each peptide map was distinguishable, and differences are most prominent between the HIV-1 group and the SIVmac/SIVsm group. HIV-2 is very similar to SIVmac and SIVsm. The three SIVagm isolates form a more heterogeneous group. The p24s of all SIVagms are more similar to the p24s of HIV-1, but with respect to p 18, one isolate is similar to HIV-1, while the two others are more related to SIVmac, SIVsm, and HIV-2.

Cercopithecidae↗
PubMedDate not supplied

Long-standing hiccup in a patient with sarcoidosis.

The patient was a 67-year-old male. A diagnosis of sarcoidosis was made both by transbronchial lung biopsy and by scalene node biopsy. The findings of his chest roentgenogram were categorized as the group II. There were no symptoms during follow-up period of one year at the out-patient clinic with no medication. The chest X-ray findings of the patient were slowly progressive. Intractable hiccup developed one year after his first visit to the hospital. With administration of prednisolone, serum angiotensin converting enzyme level decreased promptly, and the incidence of the hiccup attack decreased. As the dose of prednisolone was tapered, the hiccup recurred. All the drugs used for hiccup including quinidine sulfate and metoclopramide was not effective. A thoracic CT revealed slight enlargement of mediastinal lymph nodes. A brain CT and a brain MRI demonstrated no abnormalities. Acetazolamide, which induces acidosis in brain extra-cellular fluid, worsened the symptoms. As prednisolone was given again, infiltrates on the chest roentgenogram began to resolve and the incidence of hiccup decreased. We concluded that the long-standing hiccup observed in this patient may be brought by the lesion in central nervous system due to sarcoidosis.

Aged↗
PubMedDate not supplied

Immunohistochemical localization of epidermal growth factors in mouse olfactory epithelium.

Our object was to clarify changes in epidermal growth factor (EGF) occurring in the olfactory epithelium with aging. We investigated the changes in EGF in the murine olfactory epithelium with aging by an immunohistochemical method. We examined six mice at each of the following stages: embryonal (embryonic days 14 and 16), neonatal (postnatal days 1 and 7), adult (postnatal weeks 5 and 12), and aged (postnatal years 1.5-2). The olfactory epithelium of each mouse was stained with anti-EGF polyclonal IgG using an immunohistochemical method. EGF were observed in the whole layer of the olfactory epithelium at all stages. The mesenchyme under the epithelium was stained in the embryonal stage, and the circumference of the olfactory gland cells was also stained, although weakly, in the adult stage. We believe that EGF contribute to cell proliferation, growth and turnover of the olfactory epithelium. However, the decrease in EGF was less than expected in the aged mice.

Age Factors↗
PubMedDate not supplied

Health and welfare data on optical memory cards in Isehara city.

An off-line network system of health and welfare for elderly people using optical memory cards has been established in Isehara city (Japan) since 1991. 2775 citizens have the cards and 24 offices have the terminals. It covers almost one third of people aged over 65 in Isehara city and almost all of the offices concerned with their health and welfare. About a half of holders use optical memory cards every time they visit these offices. The optical memory card holds data including basic data for health and welfare, health check data over 5 years, medical images with scripts and history of welfare services. All the data are used for medical care, health consultation and management of health and welfare services. A card can hold health and welfare data for a lifetime, and it is easy to expand the system. It has been a good experience for us, because the optical memory card system needs co-operation among citizens, medical association and local government, and the experience will help us to expand the system in the future.

Aged↗
PubMedDate not supplied

Plasma VEGF concentration can predict the tumor angiogenic capacity in non-small cell lung cancer.

We assessed the clinical utility of circulating angiogenic factors as a predictor for tumor angiogenesis in primary lung cancer. Circulating vascular endothelial growth factor (VEGF) and intratumoral VEGF were assessed by enzyme-linked immuno-sorbent assay (ELISA). There was a significant increase in the mean value of both plasma and serum VEGF concentration in primary lung cancer patients (n=97) compared to those of healthy controls (n=59). There was a significant correlation between plasma VEGF levels and microvessel density (MVD), and also between plasma VEGF and intratumoral VEGF levels. Plasma VEGF in patients with lung cancer appears to be a useful indicator of tumor angiogenesis.

Adult↗
PubMedDate not supplied

Improved long-term survival following complete eradication of esophageal varices by sclerotherapy.

BACKGROUND/AIMS: Conflicting results have been reported concerning the effect of endoscopic injection sclerotherapy upon the long-term survival of cirrhotic patients with esophageal varix. The recurrence and rebleeding of esophageal varices seems to be an important factor influencing long-term survival. We investigated the long-term survival of patients after complete eradication of esophageal varices. METHODOLOGY: Forty patients treated by endoscopic injection sclerotherapy for acute esophageal variceal bleeding were studied. The recurrence rate of varices and the long-term survival of patients in whom complete eradication of esophageal varices was obtained were compared with those of patients in whom the eradication of varices was incomplete. RESULTS: The frequency of the recurrence/deterioration rate of varices and rebleeding in the complete eradication group was significantly lower than that in the incomplete eradication group (10.7% vs. 100%, 0% vs. 58.3%, respectively, p < 0.01). Accumulated 5-year survival rate of the complete eradication group was significantly higher than that of the incomplete eradication group (68.2% vs. 43.2%, p < 0.05). CONCLUSIONS: Complete eradication of esophageal varices by endoscopic injection sclerotherapy is effective both in preventing variceal re-bleeding and in improving the survival of cirrhotic patients with esophageal varices.

Acute Disease↗
PubMedDate not supplied

Perforated duodenal diverticulum: report of two cases.

Duodenal diverticula may be complicated by diverticulitis, perforation, hemorrhage, pancreatitis, or biliary obstruction. Two cases of perforated duodenal diverticulum are reported. Both patients were elderly females. Computed tomography of the abdomen showed retroperitoneal air around the duodenum in the first case, and an enterolith in a duodenal diverticulum and a retroperitoneal abscess in the second case. Laparotomy and diverticulectomy with two-layer closure of the duodenum was performed in the first case. The second patient was treated conservatively with antibiotics, percutaneous abscess drainage, and endoscopic lithotomy. Both recovered well. Computed tomography is useful in the diagnosis of a perforated duodenal diverticulum. Although surgical intervention is the standard treatment, conservative therapy is also an option. Duodenal enteroliths are rare but may cause perforation of a diverticulum or biliary obstruction. The duodenal blind loop created by a Billroth II gastrectomy provides a static environment for the formation of enteroliths in duodenal diverticula.

Abdominal Abscess↗
PubMedDate not supplied

Metallothionein expression in transplantable mouse mammary tumors.

BACKGROUND: The metal binding protein, metallothionein (MT) is involved in various physiological processes. In various human tumors, moreover, MT is reported to play an important role in carcinogenesis. MATERIALS AND METHODS: MT expression was investigated immunohistochemically and chromatographically in a transplantable pregnancy-dependent mouse mammary tumor (TPDMT-4) and related autonomous tumor sublines (T4-OI320 and -OI320CY). RESULTS: All tumor lines showed MT expression in the nucleus and/or cytoplasm of tumor cells. However, adenoacanthomatous T4-OI320 whose structure was different histopathologically from the remaining adenocarcinomas showed over-expression of MT in the basal layer of squamous metaplastic nodules. Cell proliferation activity estimated by the BrdU labeling method (BrdU index) was highest in the squamous nodules and correlated with the degree of MT expression (r = 0.96). By contrast, the BrdU index in T4-OI320CY was inversely correlated with the MT index (r = -0.91). CONCLUSIONS: The present investigation suggests expression of isotype MT in the transplantable mouse mammary tumors which may be involved in the carcinogenesis.

Adenocarcinoma↗
PubMedDate not supplied

Tumor size and extension of lymph node metastases in N2 lung cancer.

In all patients with NSCLC, systematic nodal dissection was performed. Since 1981, 218 stage IIIA-N2 cases were resected. We registered 2 operative mortalities. Overall survival was 23% while, in completely resected cases, survival amounted to 30%. For long-term survival, favourable prognostic factors were cN2 T1-2 N2M0, single mediastinal node involvement and a tumor 20 mm or less in maximum size. The 5 yr survival rates of stage IIIA N2 patients was, respectively 48.1% with tumor diameter < 20 mm, 27.7% with diameter between 21-30 mm, 31.2% with diameter between 31-50 mm and, finally, 16.7% with tumors larger than 51 mm. When micrometastases to lymph nodes in p-stage I (stained with H-E) were examined with immunohistochemical staining, 27% (36 patients of 132) showed micrometastases.

Carcinoma, Non-Small-Cell Lung↗
PubMedDate not supplied

Papaverine combined with prostaglandin E2 synergistically induces neuron-like morphological changes and decrease of malignancy in human prostatic cancer LNCaP cells.

We are interested in the possibility of new prostate cancer therapy that would control tumor malignancy via the induction of terminal cell differentiation. Here, we investigated the combined effect of various cAMP reagents on LNCaP human prostate carcinoma cells. Papaverine and prostaglandin E2 (PGE2), combined synergistically induced morphological changes. Electron microscope study suggested that cells treated with both reagents become like neuroendocrine cells. We then investigated the effect of both reagents on proliferation and malignancy of LNCaP cells. The malignancy of cells was analyzed by soft agar colony-forming assay and an in vitro invasion assay. Proliferation and malignancy of LNCaP cells treated with both reagents were significantly decreased in comparison to the proliferation and malignancy of untreated cells. Furthermore, the expression of oncogenes such as c-myc and Bcl-2 was suppressed in differentiated LNCaP cells. These results suggest that papaverine combined with PGE2 can synergistically induce neuronal differentiation as well as decrease the malignancy of human prostatic cancer LNCaP cells.

Actins↗
PubMedDate not supplied

Metallothionein expression and apoptosis in pregnancy-dependent and -independent mouse mammary tumors.

BACKGROUND: A metal binding protein, metallothionein (MT), may be involved in the regulation of carcinogenesis and apoptosis in addition to various physiological processes. MATERIALS AND METHODS: MT and sex hormone receptors (estrogen and progesterone receptors, ER and PR) expressions, and apoptosis were investigated immunohistochemically in pregnancy-dependent (PDMT) and -independent mammary tumors (PIMT) in GR/A mice in order to evaluate the possible role of MT in the genesis and regression of tumors. RESULTS: In PDMT and PIMT, MT was localized in the nucleus and/or cytoplasm of tumor cells. In PDMT, MT expression and apoptotic figures were increased during the regression period after parturition. MT and ER expressions in PIMT were approximately the same as those in the growing PDMT, while PR expression was lower in PIMT than in the PDMT. A significant correlation was observed between MT expression and apoptosis in PDMT, but not in PIMT. CONCLUSION: The present study suggests that MT involvement in the PDMT regression is associated with apoptosis.

Animals↗