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Biomedical subjects

H Yano

Publications and source records attributed to H Yano.

At least 253 records · Page 14Linked to original sources
PubMed1996

Changes in endothelial nitric oxide synthase mRNA during vasospasm after subarachnoid hemorrhage in monkeys.

OBJECTIVE: We attempt to determine whether changes in messenger ribonucleic acid (mRNA) for nitric oxide synthase (NOS) and soluble guanylate cyclase, enzymes that mediate endothelium-dependent vasodilation in cerebral arteries, occur after subarachnoid hemorrhage (SAH) in monkeys. METHODS: Baseline cerebral angiograms were obtained, and right-sided SAH was induced by microsurgically placing autologous blood clot against the right anterior circle of Willis in seven monkeys. Seven days later, angiographic studies were repeated and the animals were killed. Right (vasospastic) and left (control) middle cerebral arteries and underlying cortex were removed. The competitive reverse transcriptase polymerase chain reaction was used to quantify mRNA for soluble guanylate cyclase and two isoforms of constitutive NOS in these tissues. RESULTS: Comparison of angiograms at baseline and after 7 days showed a 41 +/- 7% (mean +/- standard error of the mean, P < 0.05, Wilcoxon test) decrease in diameter of the right middle cerebral artery. After the animals were killed, comparison of right and left middle cerebral arteries showed a 56 +/- 11% decrease (P < 0.005, paired t test) in endothelial NOS mRNA. There was a 142 +/- 39% (P < 0.05) increase in right cortex endothelial NOS mRNA compared to the left cortex. There were no significant differences between right and left sides in mRNAs for soluble guanylate cyclase or brain NOS. CONCLUSION: Decreased endothelial NOS mRNA in cerebral arteries 7 days after SAH may be caused by endothelial cell damage and could contribute to vasospasm after SAH. Increased endothelial NOS in brain tissue may reflect a compensatory vasodilator mechanism of the brain against the cerebral ischemia associated with vasospasm and SAH.

Animals↗
PubMed1996

Developmental stage-specific and nitrate-independent regulation of nitrate reductase gene expression in rapeseed.

cDNA clones for two isogenes of nitrate reductase (NR) have been isolated from rapeseed (Brassica napus L.) androgenetic haploid embryos induced by microspore culture. NR mRNA accumulation can be detected by northern hybridization at 14 d after culture initiation when embryos develop to the heart/torpedo-shaped stage. Whole-mount in situ hybridization experiments demonstrate that the mRNA accumulation is developmental stage specific. In addition, even when cultured in media containing no nitrate, embryos accumulated NR mRNA to almost the same level as the control. This indicates the unique regulation of NR in embryogenesis in which NR mRNA transcription is activated in a developmental stage-specific manner that is independent of nitrate induction. In zygotic embryogenesis, a stage-specific accumulation of NR mRNA was also observed. By contrast, the obvious effect of nitrate on NR expression that has been reported in many plant species was also confirmed in rapeseed leaf. Quantitative combined reverse transcription-polymerase chain reaction analysis suggests that the flexible and variable regulation of NR expression, which is organ specific, nitrogen metabolite specific, and developmental stage specific, is caused principally by regulation of one major structural gene.

Base Sequence↗
PubMed1996

Evidence that implicates the parathyroid hormone-related peptide in vascular stenosis. Increased gene expression in the intima of injured carotid arteries and human restenotic coronary lesions.

Proliferation of vascular smooth muscle cells (VSMCs) is considered to be one key event underlying the pathophysiology of restenosis after angioplasty. The parathyroid hormone-related peptide (PTHrP) and its receptor, a local autocrine and paracrine regulator of cellular growth in a variety of normal cell types, have been reported in the vicinity of VSMCs. To investigate how PTHrP might be involved in the process of neointimal formation after balloon angioplasty, we examined PTHrP expression in balloon-denuded rat carotid arteries and human coronary arteries that had been retrieved by directional atherectomy. In rat carotid arteries, the RNase protection assay and in situ hybridization demonstrated that PTHrP mRNA expression increased fourfold to sixfold 1 to 7 days after denudation and continued for 28 days, coincident with downregulation of PTH/PTHrP receptor mRNA expression. In situ hybridization and immunohistochemistry revealed that PTHrP expression in balloon-denuded carotid arteries was mainly localized to the neointima. To confirm the involvement of the PTHrP in human coronary artery restenotic lesions, immunohistochemical analysis of human coronary atherectomy specimens (23 primary and 10 restenotic lesions) was then performed. The number of intimal cells that expressed PTHrP protein was significantly higher in restenotic (407 +/- 53 cells/mm2; range, 143 to 739) than in stable angina (50 +/- 12 cells/mm2; range, 18 to 132; P<.05) or unstable angina (129 +/- 16 cells/mm2; range, 21 to 232; P<.05) specimens. These data demonstrate that PTHrP gene expression in VSMCs markedly increases during neointimal formation, supporting the hypothesis that PTHrP may play an important role in vascular stenosis as a regulator of VSMC proliferation.

Adult↗
PubMed1996

Effect of ginseng radix on GLUT2 protein content in mouse liver in normal and epinephrine-induced hyperglycemic mice.

The oral administration of the water extract of Ginseng Radix (GR) to normal and epinephrine-induced hyperglycemic mice caused a significant decrease in the blood glucose level 4 h after its administration. The hepatic content of facilitative glucose transporter isoform 2, liver type glucose transporter (GLUT2) protein content from mouse liver significantly increased in the orally GR-treated normal and epinephrine-induced hyperglycemic mice compared to that in the controls. These results suggest that the hypoglycemic activity of GR is presumably due, at least in part, to the increment of GLUT2 protein content.

Animals↗
PubMed1996

Characterization of cultured rat embryonic palatal mesenchymal cells.

To investigate developmental palatogenesis, the establishment of palatal cell culture in vitro is preferable to eliminate several complicated biases present in the in vivo environment. We established a primary culture of rat embryonic palatal mesenchymal cells using a special technique to dissect embryonic palatal shelves, and characterized these embryonic cells by immunohistochemical analysis against histiocytic markers. Following preparation of the maxilla of 15.5-day-old rat fetuses, a midline incision of the maxilla was established while the occiput was fixed with microforceps. This procedure allowed eversion of the maxillary process and easy dissection of the palatal shelf. The technique allowed preparation of a large number of palatal shelves with no appendages using a small number of fetuses. Cells cultured with DMEM/F-12 and 10% FBS showed multipotential nature (i.e., not only mere mesenchymal character but also neural, endothelioid, and/or myoblastoid origin were identified by immunostaining with anti-epithelium membrane antigen, keratin, vimentin, S-100 protein, factor VIII, desmin, and lysozyme antibodies, respectively). Our results demonstrated that, during several cell passages, the cultured cell gained myoblastoid characteristics in addition to a neural nature. Further in vitro studies using cultured embryonic palatal mesenchymal cells will assist in characterization of proliferation and differentiation of cells forming the palate.

Animals↗
PubMed1996

Immunosuppressive effect of tacrolimus (FK-506). Bone xenografts in rabbits.

We examined the immunomodulatory effect of the macrolide antibiotic FK-506 (tacrolimus) in bone xenograft transplantation. Full-thickness pieces of iliac bone from mongrel dogs were transplanted into the iliac bone of Japanese white rabbits. FK-506 at a dose of 1.6 mg/kg/day was injected into the rabbits for 10 days after transplantation. In the animals treated with FK-506, inflammatory cell infiltration was remarkably reduced and revascularization accompanied by new bone formation occurred in the grafts. At 4 months after the transplantation, the formation of new bone and of mature new bone marrow were observed. In a control group, inflammatory cell infiltration was marked around the graft from 2 weeks after the transplantation. Revascularization from the recipient site to the graft in the control group was poor and only a small amount of new bone had formed at 4 months. Our findings suggest that short-term administration of FK-506 has a beneficial effect on experimental xenograft bone transplantation.

Animals↗
PubMed1996

[Survey on oral health of university students: examination on tooth conditions using panoramic X-ray films].

As an aid in instructions oral health care to university students, tooth conditions were examined using panoramic X-ray films. The materials were taken from 129 students of the University of Tokyo. The average age was 22 years 5 months. The results were as follows: 1. Lack of tooth was frequently found to be both maxillary and mandibular third molars. It was also occasionally found to be maxillary first premolars, mandibular lateral incisors, and mandibular second premolars. The average value for lack of tooth per individual was 0.9. 2. Root canal fillings were often found in mandibular first molars, maxillary central incisors, mandibular second molars and maxillary second premolars. The average value was 1.1. 3. Metal restorations were often made in first and second molars, especially in mandibular. The average value was 6.2. 4. As for maxillary third molar axis, the majority showed normal direction. In mandible, however, the normal direction was only found in 37.7% and the others showed troublesome axes. It seemed that careful attention should be given to the mandibular third molar conditions.

Adult↗
PubMed1996

[Spontaneous renal rupture due to xanthogranulomatous pyelonephritis; a case report].

A 47-year-old female was admitted with colicky pain in the left flank. Ultrasonography and abdominal CT revealed left perirenal hematoma. Abdominal CT revealed a multilocular cystic lesion in the upper pole of the left kidney. Renal angiography revealed left renal cell carcinoma. Left nephrectomy was performed under a tentative diagnosis of left renal cell carcinoma. However, pathological diagnosis was xanthogranulomatous pyelonephritis. Xanthogranulomatous pyelonephritis is an atypical form of chronic renal parenchymal infection that can be classified as diffuse type or focal type. Preoperative diagnosis of focal xanthogranulomatous pyelonephritis is difficult because of clinical and radiological similarities to renal cell carcinoma. Our case is presented with a brief review of the literature.

Carcinoma, Renal Cell↗
PubMed1996

Fas antigen expression and its relationship with apoptosis in human hepatocellular carcinoma and noncancerous tissues.

Apoptosis, a programmed cell death, can be observed in the tissues of viral or autoimmune hepatitis and of hepatocellular carcinoma. Fas antigen (Fas) was proposed as a protein that triggers apoptosis. To elucidate the relationship between Fas expression and its location in hepatocellular carcinoma cells, we histochemically examined Fas expression by using 25 hepatocellular carcinoma tissues and their corresponding noncancerous tissues, which were surgically obtained from the same patients. In addition, the relationship between Fas expression and apoptotic cell numbers was examined in the hematoxylin-and-eosin-stained specimens obtained from 23 of the 25 patients. Hepatocellular carcinoma tissues expressed Fas less frequently and more weakly than noncancerous tissues. The majority of noncancerous specimens expressed Fas both on the surface and in the cytoplasm, whereas the majority of hepatocellular carcinoma expressed Fas only in the cytoplasm. Apoptotic cell counts were significantly higher in Fas-expressing tissues than in Fas-negative tissues. Among Fas-expressing tissues, the counts were higher in surface Fas-expressing tissues than in tissues that expressed only cytoplasmic Fas (P < 0.01 to 0.05). Our findings indicate that the development of apoptosis in hepatocellular carcinoma tissues relates to not only Fas expression but also its location.

Adult↗
PubMed1996

[Intra-arterial infusion chemotherapy for liver metastases from breast cancer].

Twelve patients with liver metastases of breast cancer were treated with hepatic arterial infusion chemotherapy using 20-30 mg/body of epi-adriamycin (epi-ADM) every 2 weeks and continuous infusion of 250 mg/body/day of 5-fluorouracil (5-FU). All patients were followed by systemic chemo-endocrine therapy with oral administration of 600-1,200 mg/day of me droxyprogesterone acetate (MPA) alone or with 600-800 mg/day of 5'-deoxy-5-flurouridine (5'-DFUR). The response rate was 41.7% (5/12 cases). Duration of response was 2-28 months (mean 10 months). At one year, the survival rate was 46.8% (Kaplan-Meier method). As for side effects, gastrointestinal disturbance, bone marrow depression and alopecia were mild. These results suggest that hepatic arterial infusion therapy in combination with MPA is safe and effective for controlling liver metastases of breast cancer.

Adult↗
PubMed1995

Suppression by amiloride of bombesin-enhanced peritoneal metastasis of intestinal adenocarcinomas induced by azoxymethane.

The effects of concomitant administration of bombesin and of the diuretic drug amiloride on the development of large and small intestinal tumors induced by azoxymethane (AOM), the incidence of their metastasis to the peritoneum and the labeling index of intestinal adenocarcinomas were investigated in inbred Wistar rats. From the start of the experiment, rats were given weekly s.c. injections of AOM for 10 weeks and s.c. injections of bombesin and/or a higher or lower dose of amiloride hydrochloride (amiloride) every other day until the end of the experiment in week 45. Administration of bombesin significantly increased the incidence of intestinal tumors and cancer metastasis to the peritoneum in week 45. It also significantly increased the labeling index of intestinal adenocarcinomas. Although administration of both doses of amiloride with bombesin had little or no influence on the enhancement of intestinal tumorigenesis by bombesin, the location, histological type, depth of involvement or labeling index of intestinal adenocarcinomas, a higher dose of amiloride significantly reduced the incidence of cancer metastasis to the peritoneum. Our findings indicate that amiloride possesses an anti-metastatic activity.

Adenocarcinoma↗
PubMed1995

Biochemical and pharmacological studies with KT7692 and LY294002 on the role of phosphatidylinositol 3-kinase in Fc epsilon RI-mediated signal transduction.

Wortmannin inhibited phosphatidylinositol 3-kinase (P13-kinase) and Fc epsilon RI-mediated histamine secretion in RBL-2H3 cells to a similar degree, with IC50 values of 3 and 2 nM, respectively. Although P13-kinase is an acknowledged regulator of intracellular trafficking and secretion, wortmannin has proved to be a difficult drug to use in assessing the role of P13-kinase because it inhibits another important enzyme, myosin light-chain kinase (MLCK; IC50 = 200 nM). In the present study we synthesized a unique derivative of wortmannin, O-acetyl-delta 16-wortmannin-17-ol (KT7692), that has an inhibitory potency against PI3-kinase one-hundredth that of wortmannin, but retains a similar potency to wortmannin against MLCK. Histamine secretion was influenced 100-fold more by wortmannin than by KT7692.2-(4-Morpholinyl)-8-phenyl-4H-1-benzopyran-4-one (LY294002), a structurally different PI3-kinase inhibitor from wortmannin, inhibited PI3-kinase with an IC50 of 2 microM but had little effect on MLCK activity in this concentration range. LY294002 also inhibited histamine secretion in RBL-2H3 cells with an IC50 of 5 microM. These results provide further evidence that PI3-kinase is involved in the signal transduction pathway responsible for histamine secretion after stimulation of Fc epsilon RI. Furthermore KT7692 in combination with wortmannin and LY294002 would be a powerful tool for clarifying the involvement of PI3-kinase as distinct from that of MLCK in signal transduction systems of various cellular responses.

Androstadienes↗
PubMed1995

Expression of autocrine motility factor receptor in human esophageal squamous cell carcinoma.

Autocrine motility factor and its receptor (gp78) have been shown to play an important role in tumor cell migration, invasion and metastasis. We have detected gp78 expression in buffered-formalin-fixed, paraffin-embedded sections of esophageal squamous cell carcinomas using an anti-gp78 monoclonal antibody (MAb), 3F3A, and examined the relationship between gp78 expression and clinicopathological and prognostic factors. In 55 of 101 (54%) patients, gp78 was detected in the tumor cells. The frequency of gp78-positive expression was significantly associated with tumor size, infiltrative growth, depth of invasion and lymph node metastasis. The cumulative survival rate of patients with gp78 was significantly lower than that of patients without gp78. Our results suggest that autocrine motility factor receptor (gp78) expression could be a useful biomarker for malignancy grading and prognosis in patients with esophageal squamous cell carcinoma.

Adult↗
PubMed1995

Transcriptional regulation of the chicken caldesmon gene. Activation of gizzard-type caldesmon promoter requires a CArG box-like motif.

Caldesmon, which plays a vital role in the actomyosin system, is distributed in smooth muscle and non-muscle cells, and its isoformal interconversion between a high M(r) form and low M(r) form is a favorable molecular event for studying phenotypic modulation of smooth muscle cells. Genomic analysis reveals two promoters, of which the gizzard-type promoter displays much higher activity than the brain-type promoter. Here, we have characterized transcriptional regulation of the gizzard-type promoter. Transient transfection assays in chick gizzard smooth muscle cells, chick embryo fibroblasts, mouse skeletal muscle cell line (C2C12), and HeLa cells revealed that the promoter activity was high in smooth muscle cells and fibroblasts, but was extremely low in other cells. Cell type-specific promoter activity depended on an element, CArG1, containing a unique CArG box-like motif (CCAAAAAAGG) at -315, while multiple E boxes were not directly involved in this event. Gel shift assays showed the specific interaction between the CArG1 and nuclear protein factors in smooth muscle cells and fibroblasts. These results suggest that the CArG1 is an essential cis-element for cell type-specific expression of caldesmon and that the function of CArG1 might be controlled under phenotypic modulation of smooth muscle cells.

Animals↗
PubMed1995

Promotion by substance P of gastric carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine in Wistar rats.

The effects of prolonged administration of neuropeptide substance P (SP) on gastric carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and on the labeling index of gastric mucosa were investigated in Wistar rats. Rats received subcutaneous injections of 12 micrograms/kg body weight of SP every other day after 25 weeks of oral treatment with MNNG. Long-term administration of SP significantly increased the incidence of gastric cancers in week 52. However, it did not affect the histological type and depth of involvement of gastric cancers. SP also caused a significant increase in the labeling index of the antral and fundic epithelial cells in week 52. These findings indicate that SP promotes gastric carcinogenesis and suggest that this effect may be related to its stimulation of antral epithelial cell proliferation.

Animals↗
PubMed1995

Sequence analysis of the MAGE gene family encoding human tumor-rejection antigens.

The MAGE multigene family, which includes the MAGE-1 and -3 genes that encode tumor-rejection antigens on HLA-A1 recognized by cytotoxic T-lymphocytes (CTL), is preferentially expressed at the mRNA level on human malignant cells, but not on normal cells. However, little is known about the MAGE-4, -41 and -6 genes. In this study, we have amplified 1040 bp (MAGE-1), 1061 bp (MAGE-3 and -6) and 1064 bp (MAGE-4 and -41) cDNA fragments, including the entire coding sequences (927-951 bp), using the reverse transcription-polymerase chain reaction (RT-PCR) method followed by nucleotide (nt) sequencing. One member had greater than 80 or 66% homology with the other members at the nt or deduced amino acid (aa) levels, respectively. Higher homology was found between MAGE-3 and -6 (98% at the nt level) and also between MAGE-4 and -41 (98%). The results of this investigation demonstrated high homology, as well as the clear differences between the members of the MAGE family at the coding sequence level.

Amino Acid Sequence↗