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Biomedical subjects

H Hirano

Publications and source records attributed to H Hirano.

At least 163 records · Page 9Linked to original sources
PubMed1997

Unique tissue distribution of a mouse macrophage C-type lectin.

We examined mouse tissue for the expression of macrophage galactose/N-acetylgalactosamine-specific C-type lectin using a rat monoclonal antibody (mAb) specific for this lectin (mAb LOM-14). The binding of mAb LOM-14 was detected in detergent extracts from tissue by means of immunoblotting analysis. It was shown that this mAb did not cross-react with mouse hepatic lectins, a structural homologue. The macrophage lectin was widely distributed among various mouse tissues as judged by the affinity isolation followed by the immunochemical detection. The exceptions were brain, liver, kidney, small intestine, and peripheral blood. Extracts from these organs exhibited, at best, very weak signals upon mAb LOM-14 binding, despite the presence of cells expressing macrophage markers. The most intense signal was observed in the extract from skin, suggesting that cells expressing this lectin are abundant in skin. The tissues shown to contain this lectin were further investigated by immunohistochemical staining of the sections. Cells were distributed in the connective tissue and in the interstice, particularly the dermis and subcutaneous layer of skin. Cells localized in the epithelium of skin (epidermis) or other epithelia that we examined were not stained. Perivascular localization of cells stained with mAb LOM-14 was also demonstrated in cardiac and skeletal muscle tissues. Immunoelectron microscopy revealed the presence of this lectin along the rough endoplasmic reticulum. In conclusion, the distribution of C-type lectin specific for galactose/N-acetylgalactosamine in mice was unique. The connective tissue-specific distribution should provide important information on the biological role of this lectin.

Animals↗
PubMed1997

Possible contribution of follicular interleukin-1beta to nitric oxide generation in human pre-ovulatory follicles.

The aim of this study was to investigate the relationships between follicular nitric oxide (NO) metabolite concentrations and several related variables, with special reference to follicular interleukin-1beta (IL-1beta). The follicular fluid from the leading and secondary follicles was collected individually from 20 women undergoing in-vitro fertilization (IVF) treatment, and the concentrations of nitrite (NO2-) and nitrate (NO3-) were determined fluorometrically using 2,3-diaminonaphthalene. Both follicular nitrite (r = 0.42, P < 0.01) and nitrate (r = 0.49, P < 0.001) were found to be significantly correlated with follicular IL-1beta concentrations. There were also significant positive correlations between follicular nitrate and the number of oocytes retrieved (P < 0.01) and serum oestradiol concentration on the day of human chorionic gonadotrophin (HCG) administration (P < 0.05). When follicular cells were incubated in vitro with 10 ng/ml of IL-1beta for 24 h, nitrate generation was significantly (P < 0.01) elevated compared with the control. In conclusion, our study demonstrates that follicular IL-1beta and the number of developing follicles are significant variables that affect follicular NO concentrations, and points to the possible contribution of IL-1beta to NO generation in human preovulatory follicles.

2-Naphthylamine↗
PubMed1997

Negative regulation in the expression of a sugar-inducible gene in Arabidopsis thaliana. A recessive mutation causing enhanced expression of a gene for beta-amylase.

Expression of a beta-amylase gene of Arabidopsis thaliana (AT beta-Amy) is regulated by sugars. We identified a mutant, hba1, in which the level of expression of AT beta-Amy in leaves of plants that had been grown in a medium with 2% sucrose was significantly higher than that in wild-type plants. Higher that wild-type levels of beta-amylase in hba1 plants depended on the presence of 1 to 2% sucrose or 1% glucose in the medium, whereas leaves of mutant plants grown with higher levels of sugars had beta-amylase activities similar to those in leaves of wild-type plants. The hba1 phenotype was recessive and did not affect levels of sugars and starch in leaves. It is proposed that expression of AT beta-Amy is regulated by a combination of both positive and negative factors, dependent on the level of sugars, and that HBA1 might function to maintain low-level expression of AT beta-Amy until the level of sugars reaches some high level. Results of crosses of hba1 plants with transgenic plants that harbored an AT beta-Amy:GUS transgene with 1587 bp of the 5'-upstream region suggested that HBA1 affects expressions of AT beta-Amy in trans. The hba1 plants also had growth defects and elevated levels of anthocyanin in their petioles. However, sugar-related changes in levels of several mRNAs other than beta-amylase mRNA were unaffected in hba1 plants, suggesting that only a subset of sugar-regulated genes is under the control HBA1.

Anthocyanins↗
PubMed1997

The N-terminal propeptide of the precursor to sporamin acts as a vacuole-targeting signal even at the C terminus of the mature part in tobacco cells.

An asparagine-proline-isoleucine-arginine-leucine (NPIRL) and its related sequences in the N-terminal propeptides (NTPP) of several plant vacuolar proteins, including that of sporamin from sweet potato (SPO) function as vacuole-targeting determinants in a manner that is distinct from the vacuole-targeting determinant in the CTPPs of other plant vacuolar proteins. When the mutant precursor to sporamin, SPO-NTPP (in which NTPP was moved to the C terminus of the mature part), was expressed in tobacco (Nicotiana tabacum) cells, the pro-form was efficiently targeted to the vacuole and the NTPP was cleaved off. Unlike the results obtained with the wild-type precursor, substitution of the NPIRL sequence in the C-terminally located NTPP to asparagine-proline-glycine-arginine-leucine in the SPO-isoleucine-28-to-glycine mutant resulted in missorting of less than 20% of the pro-form to the medium. Unlike the vacuolar transport of SPO-NTPP, the vacuolar transport of SPO-isoleucine-28-to-glycine was strongly inhibited by 33 microM wortmannin, which is similar to the C-terminal propeptide-mediated vacuolar transport. These results suggest that the vacuole-targeting function of the NPIRL sequence is not strictly dependent on its location at the N terminus of a protein and that the C-terminally located mutant NTPP acquired some physicochemical properties of the C-terminal vacuole-targeting sequence.

Amino Acid Sequence↗
PubMed1997

Growth inhibition of Helicobacter pylori by monoclonal antibody to heat-shock protein 60.

The H20mAb recognizing the 60-kilodalton protein, which existed in the outer membrane and was induced by heat shock at 42 C, was established. The molecule recognized with the mAb was a heat-shock protein 60 (HSP60) of Helicobacter pylori. To understand the role of HSP60 on the cell surface of H. pylori, whether or not H20mAb affects the growth of H. pylori was investigated. When bacteria were cultured with H20mAb, growth was markedly inhibited after 24 hr, although an initial 5 hr-incubation with the mAb induced no significant inhibition of H. pylori growth. The 24- and 48 hr growth of the bacteria after washing to remove the mAb at 5 hr was also inhibited though the inhibitory effect was not strong. In electron microscopical analysis, the spots with high electron density in the cytoplasm of the bacteria treated with H20mAb were increased, depending on the length of incubation time from 5 to 24 hr. After 24 hr treatment with H20mAb, bacterial destruction was also observed, indicating bactericidal activity by H20mAb. These results suggest that the HSP60 on the cell surface of H. pylori might have an essential role in the growth of the bacteria.

Amino Acid Sequence↗
PubMed1997

Intrinsic ureteric involvement by endometriosis: a case report.

Endometriosis occasionally involves the urinary tract, and a ureteral obstruction from this order constitutes a rare variant with serious consequences. Intrinsic ureteric involvement by endometriosis is an exceedingly rare event. This case report describes intrinsic ureteric involvement by endometriosis. The case involved 47-year-old woman, gravida 4, para 2, who had a 4-year history of dysmenorrhea and hypermenorrhea. An intravenous pyelogram showed a right hydronephrosis. She underwent a total abdominal hysterectomy and a right ureteroureterostomy. A pathologic examination revealed complete obstruction of the right ureter by intrinsic intramural endometriosis. We conclude that because ureteral endometriosis, especially intrinsic endometriosis, is usually silent and results in a high rate of renal loss before recognition, physicians should have a hightened awareness of this uncommon but serious manifestation of endometriosis.

Endometriosis↗
PubMed1997

CD44 isoform expression in periodontal tissues: cell-type specific regulation of alternative splicing.

CD44 functions as a receptor for various extracellular matrices and plays crucial roles in homotypic and heterotypic cell-cell interactions. Recently, the molecular structure of CD44 has been extensively analyzed and multiple isoforms produced by alternative splicing of messenger RNA have been identified. In this study, we examined the expression of CD44 isoforms on different cell types isolated from periodontal tissue. In order to examine tissue differences in CD44 isoform expression, we established in vitro cell culture of human gingival fibroblasts (HGF), human periodontal ligament cells (HPDL) and human gingival epithelial cells (HGEC). These cells all expressed CD44 protein and messenger RNA. However, immunoprecipitation and Northern blot analysis revealed that HGEC expressed larger CD44 isoforms than HGF and HPDL. Reverse transcription-polymerase chain reaction with primers flanking the insertion site of alternatively spliced exons was used to study details of the heterogeneity. All cells examined expressed a major band in the absence of alternatively spliced exons and additional larger bands. In particular, HGEC contained more abundant high molecular mass species. In vitro stimulation by IL-1 beta, TNF alpha or phorbol 12-myristate 13-acetate induced an increase in total CD44 messenger RNA in HGF but not change in overall patterns of CD44 isoform expression. However, the isoform expression of HGEC was sensitive to cell density. The amount of larger isoform was decreased by culturing cells beyond confluence. These findings suggest that CD44 isoform expression is cell type-specifically regulated in periodontium and altered according to growth phase of HGEC.

Alternative Splicing↗
PubMed1997

Immunoregulatory roles of adhesive interactions between lymphocytes and gingival fibroblasts.

Chronic adult periodontitis is usually characterized by inflammatory cell accumulation in the extravascular periodontal connective tissue. In order to reveal how the lymphocyte migration and retention in periodontal lesions is regulated, we have focused on the molecular basis for the adhesive interactions between lymphocytes and human gingival fibroblasts (HGF). In this study, we investigated the involvement of cell adhesion molecules in adhesive interactions between lymphocytes and HGF. We found that activated lymphocytes bound strongly to HGF and VLA integrins, extracellular matrix receptors, play crucial roles in the binding. Interestingly, we first revealed that CD44 molecules (hyaluronate receptor) on lymphocytes also participated in lymphocyte-HGF interactions and that hyaluronate anchored on the surface of HGF functioned as the ligand for CD44. In addition, when HGF were stimulated with inflammatory cytokines such as IL-1, TNF alpha and IFN gamma, the binding avidity between lymphocytes and HGF was significantly increased and the adhesion was mainly mediated by LFA-1/ICAM-1 pathway. We then examined the possibility whether lymphocyte-HGF interaction may cause activation of HGF. When HGF directly interacted with lymphocytes for 3 h, IL-1 beta mRNA expression was clearly increased in HGF. These findings suggested that the adhesive interactions between lymphocytes and HGF was mediated at least by VLA integrins, LFA-1/ICAM-1 and CD44/hyaluronate and that the heterotypic cell-cell interactions could mutually cause intracellular signal transduction.

Cell Adhesion↗
PubMed1997

Ambulatory blood pressure monitoring in diagnosing a pheochromocytoma of the urinary bladder. A case report.

A patient is presented in whom the preoperative diagnosis of an intravesical pheochromocytoma was facilitated by noninvasive ambulatory blood pressure monitoring. A fifty-two-year-old Japanese man suffered headache and palpitation after micturition. Cystoscopy revealed an intravesical tumor. To investigate whether his symptoms were associated with an elevation of blood pressure, the authors monitored his ambulatory blood pressure automatically for twenty-four hours. The patient was also instructed to activate the recording manually upon the onset of symptoms. As a result, elevations of blood pressure were apparent following micturition. The twenty-four-hour urinary excretion of norepinephrine was elevated on the day of the blood pressure monitoring. Pheochromocytoma was suspected and was confirmed by histopathologic studies following the operation. Thus, ambulatory blood pressure monitoring may be useful in detecting the transient hypertension induced by micturition, which can provide preoperative evidence of pheochromocytoma of the urinary bladder.

Blood Pressure Monitoring, Ambulatory↗
PubMed1997

[Two patients with mediastinal parathyroid cysts].

We encountered two patients with mediastinal parathyroid cysts. Patients 1 was a 44-year-old man with no complaints who had an abnormal shadow on a roentgenogram of the chest. An iperation was performed because a computed tomogram and a magnetic resonance image showed a cyst in the upper right part of the mediastinum, which was suspected to be a mediastinal thyroid cyst. Patient 2 was a 77-year-old woman with no complaints who had an abnormal shadow on a roentgenogram of the chest. Therapeutic thoracoscopy was performed because a mediastinal cyst was suspected based on the results of computed tomography and magnetic resonance image. Both patients had thin-walled that they were mediastinal parathyroid cysts. Mediastinal parathyroid cysts are very rare. We searched the medical literature but found previously published reports of only 39 cases.

Adult↗
PubMed1997

[The study for the surgical treatment on distal bile duct carcinoma].

The surgical result in 74 patients with resected distal bile duct carcinoma was reviewed to clarify the surgical strategy of distal bile duct carcinoma. The clinicopathological record was according to the General rules for surgical and pathological studies on cancer of biliary tract(the 3rd edition, edited by the Japanese society of biliary surgery). 58 patients underwent standard pancreatoduodenectomy and 16 patients had pylorus-preserving pancreatoduodenectomy. The curative resection was performed in 38 patients (51.3%). The overall 5-year survival rate (operated death included) was 35.8%. The 5-year survival rate in curative resection was 56.6%. The survival rate of patients with curative resection was significantly better than that of the patients with relative non-curative (p < 0.05) or absolute non-curative resection (p < 0.01). We concluded that the Long-term survival after surgical resection was mostly correlated with curability. To obtain curative resection, the free surgical margin of hw and ew was essential. As for free "hw", intraoperative frozen dissection was indispensable. For free "ew", the dissection of the soft tissues in retroperitoneum at the back of pancreas head was necessary. On the lymph node dissection, the lymph nodes of No 8, 12, 13, 14 should be removed.

Bile Duct Neoplasms↗
PubMed1997

Loss of EDB+ fibronectin isoform is associated with differentiation of alveolar epithelial cells in human fetal lung.

Cell-matrix interactions have been shown to regulate the development of the lung, particularly airway branching and alveolarization. Fibronectin is the major constituent of pulmonary extracellular matrix and exists in multiple isoforms arising from alternative RNA splicing. EDA and EDB are the two major alternatively spliced segments, the expression of which is regulated in a spatiotemporal and oncodevelopmental manner. In this study, we investigated immunohistochemically the distribution of the EDA- and EDB-containing fibronectin isoforms (referred to as EDA+ fibronectin and EDB+ fibronectin, respectively) in normal and hypoplastic human lungs at different gestational ages to explore the role of these fibronectin isoforms in alveolarization. EDA+ fibronectin was expressed around the distal airspaces throughout the development of both normal and hypoplastic lungs. In contrast, the expression of EDB+ fibronectin was restricted to the lung with morphologically immature acinar complex, typically observed in normally developing lungs of < 30 gestational weeks or in hypoplastic lungs. To further confirm the restricted expression of EDB+ fibronectin in immature acinar complex, we examined the correlation of EDB+ fibronectin expression with that of the surfactant protein SP-A, a biochemical marker for the differentiated type II pneumocytes. A clear inverse relationship between the immunoreactivities for EDB+ fibronectin and SP-A was observed in both control and hypoplastic lungs. Given the proposed importance of fibronectins in the differentiation of alveolar epithelial cells, our results suggest that the EDB segment plays a regulatory role in the differentiation of immature acinar epithelial cells into type II pneumocytes. The EDB segment may also serve as a new histochemical marker for the functional maturity of fetal lung tissues.

Alternative Splicing↗
PubMed1997

[Evaluation of single photon emission computed tomography of tumors in the head and neck with technetium-99m MIBI].

SPECT using 99mTc-MIBI was performed in patients with tumors in the head and neck in order to determine 99mTc-MIBI uptake in tumors and to evaluate the efficacy of 99mTc-MIBI imaging in the assessment of treatment response. A MIBI uptake index was calculated as the ratio of average counts/pixel in the tumor to average counts/pixel in the homologous contralateral side. Eighteen of 19 (95%) of the cases had increased MIBI uptake in the tumor on early images, and 8 of 14 (57%) of the cases had increased uptake of the tumor on delayed images. MIBI uptake was related to the size of the tumor. Only 6 of 25 of cervical lymph node metastases were detected by 99mTc-MIBI SPECT. In the tumors evaluated before and after radiotherapy, the superiority of 99mTc-MIBI SPECT over MRI was not obtained, but there was a tendency for MIBI-index to decrease after radiotherapy.

Adult↗
PubMed1997

[Central nervous system involvement of leukemia and systemic lymphoma in children: CT and MR findings].

The purpose of this paper is to retrospectively evaluate CT and MR findings of central nervous system (CNS) involvement of leukemia and systemic lymphoma in children. Over a 12-year period, sixty-five patients with leukemia and fifteen patients with systemic lymphoma underwent cerebral CT and/or MR imaging. Nine patients (11.3%) were diagnosed as CNS involvement of leukemia and lymphoma. The diagnostic criteria of CNS involvement were as follows; 1) Histological proof was confirmed by surgery, 2) Tumor cells were found in the cerebrospinal fluid examinations, 3) Increase in size of the lesion during observation without specific treatment, and 4) Response to the treatment for leukemia or lymphoma. All of nine patients fulfilled more than two criteria of 1)-4). The CT and MR abnormalities in these patients were correlated with the findings of histology, cerebrospinal fluid cytology, and/or treatment. The age of the patients ranged from 0 to 15 years old. They consisted of 6 boys and 3 girls. The CT examinations were performed before and after contrast administration. MR examinations were performed on a 1.5-T unit, and T1-weighted, T2-weighted, and proton density-weighted images were obtained using spin-echo or fast spin-echo sequences. Tumor masses were present in seven with leukemia (acute lymphoblastic leukemia 4; acute myeloblastic leukemia 1; acute promyelocytic leukemia 1; acute monocytic leukemia 1), and in two with malignant lymphoma. On the CT scan, tumor masses were hyperdense with contrast enhancement. On the MR images, their signals were variable. In all of nine patients, tumor masses were contiguous with a meningeal surface. Postcontrast T1 weighted images were valuable in demonstrating meningeal infiltration. Tumoral hemorrhage was found in two patients. In a patient with tumor at the superior sagittal sinus, venous infarct was observed. CNS leukemic and lymphomatous masses are almost hyperdense on the CT and they are characteristically contiguous with a meningeal surface. MR imaging was valuable in demonstrating meningeal infiltration. Findings of CT and MR imaging, cerebrospinal fluid examinations, and response to the treatment are useful in the differentiation of CNS involvement of leukemia and lymphoma from other lesions such as infectious diseases and leukoencephalopathy.

Adolescent↗
PubMed1996

Evidence of metal binding activities of pentadecapeptide from Panax ginseng.

A tetradecapeptide from ginseng (Panax ginseng) root showing anti-lipolytic activity in an isolated rat fat cell assay was chemically synthesized for analysis of metal binding activities in vitro. Binding activities against several metal ions were analysed by measuring mobility shifts during capillary zone electrophoresis experiments. The ginseng polypeptide (GPP) showed the greatest increase in effective molecular electrophoretic mobility in the presence of Mg2+. Mobility was also affected in the presence of La3+, Mn2+, Ca2+ and Zn2+ ions. Analysis with the dye Stains-all revealed GPP to possess a cation binding site similar to those in Ca(2+)-binding proteins. GPP thus appears to be a metal binding peptide. The results of this analysis suggested that GPP may perform its anti-lipolytic activities through an ability to modulate the level of free cellular Mg2+ and Mn2+ ions.

Animals↗