Biomedical subjects

N Hirano

Publications and source records attributed to N Hirano.

At least 55 records · Page 3Linked to original sources

PubMed1998

Acquired dural arteriovenous malformations of the lumbar spine: case report.

OBJECTIVE AND IMPORTANCE: Although dural arteriovenous malformations (AVMs) are considered to be acquired, no conclusive evidence has been obtained. The first case of dural AVMs of the lumbar spine that showed evidence supporting their being acquired lesions is described. CLINICAL PRESENTATION: A 27-year-old man was admitted to our hospital in November 1994, presenting with increasing pain and numbness in the left buttock to the left lower limb. Myelography and arteriography showed dural AVMs of the lumbar spine. However, the myelogram obtained before surgery for lumbar disc herniation in 1987 provided no findings suggestive of intradural vascular anomalies. INTERVENTION: Embolization procedures via the left iliolumbar arteries were performed. However, there was no improvement of the symptoms, and the patient underwent surgical treatment. CONCLUSION: The present report documents a case of dural AVMs of the lumbar spine that showed evidence supporting their being acquired lesions.

Adult↗

PubMed1998

Effect of neonatal thyroidectomy on growth hormone secretion in the rat.

The influence of neonatal thyroidectomy (Tx) on GH production was investigated by means of Northern blot analysis. Tx resulted in a significant decrease in pituitary GH mRNA levels after 10, 15 and 20 days. The changes of pituitary GH mRNA were soon reflected in pituitary GH content. There was, however, no significant difference in pituitary GH mRNA levels and GH content between Tx and sham-operated rats at 5 days old. The pituitary GH cells were significantly decreased in number 15 and 20 days after Tx. These data suggest that GH mRNA is transcribed, independent of thyroid hormone, in the rat anterior pituitary gland during early neonatal life. In addition, the present study ascertained that GH dependence on thyroid hormone is acquired between the 5th and 10th day of neonatal life.

Animals↗

PubMed1997

Carbon tetrachloride does not induce micronucleus in either mouse bone marrow or peripheral blood.

We performed mouse bone marrow and peripheral blood micronucleus tests on carbon tetrachloride (CCl4). In the bone marrow assay, bone marrow cells were collected once after 24 h and twice, with a 24-h interval at a dose of 500, 1000 and 2000 mg/kg. In the peripheral blood assay, blood samples were collected 0, 24, 48 and 72 h after a single intraperitoneal injection at a dose of 1000, 2000 and 3000 mg/kg. As a result, micronucleated polychromatic erythrocytes (MNPCEs) were observed neither in the bone marrow assay nor the peripheral blood assay. We concluded that CCl4 does not induce chromosomal aberrations in the mouse bone marrow cells under these experimental conditions.

Animals↗

PubMed1997

Lumbar intervertebral disc herniation in children less than 16 years of age. Long-term follow-up study of surgically managed cases.

STUDY DESIGN: In this retrospective study, the long-term clinical results of lumbar intervertebral disc herniation in children less than 16 years of age were reviewed. OBJECTIVES: To evaluate the effectiveness of surgical treatment including posterior discectomy, extraperitoneal anterolateral discectomy, and anterior interbody fusion for lumbar intervertebral disc herniation in children less than 16 years of age. SUMMARY OF BACKGROUND DATA: Although previous follow-up studies on surgically managed lumbar intervertebral disc herniation in children and adolescents generally reveal good outcomes, few reports have focused on the time course of clinical findings and the long-term results. METHODS: The outcome of subjective symptoms, clinical signs, and time-related change of the intervertebral disc space in 11 patients were evaluated with an average follow-up period of 9 years (range, 5-12 years). RESULTS: The posterior discectomy procedure relieved clinical symptoms quickly. In the case of central herniation with or without intervertebral instability, extraperitoneal anterolateral discectomy or anterior interbody fusion led to favorable long-term results. Clinical symptoms (lower back pain, leg pain) and neurologic disturbance disappeared within 3 months after surgery. Recovery of normal straight leg raising test results (tight hamstrings), however, required much more time than recovery of other symptoms. Narrowing of the intervertebral disc space progressed up to 3-6 months after discectomy, but then disc space widening occurred. CONCLUSIONS: Satisfactory long-term clinical results and early return to school life were obtained with each surgical procedure. It is important to aim toward an early return to school via surgical treatment.

Adolescent↗

PubMed1997

Protective and therapeutic immunity against leukemia induced by irradiated B7-1 (CD80)-transduced leukemic cells.

B7 molecules provide an important co-stimulatory signal for T cell receptor/CD3-mediated T cell activation via binding to their cognate receptors, CD28 and CTLA-4. We have introduced B7-1 (CD80) into M1 cells, spontaneously occurring mouse myelocytic leukemic cells, and assessed its potential to induce antitumor immunity to leukemia cells. Syngeneic, immunocompetent SL mice receiving two independent B7-1-transduced monoclonal sublines, M1-B7-1/F/clone F20 and M1-B7-1/F/clone F7, were rejected in 57% and 43% of SL mice, respectively. In vivo depletion of T cell subsets showed that both CD4+ and CD8 T cells were indispensable for the B7-1-dependent anti-leukemic immunity. Although a single exposure of irradiated monoclonal M1-B7/1/F cells was not fully effective, multiple exposures induced protective immunity against subsequent challenge with parental M1 cells. Furthermore, multiple vaccinations with irradiated monoclonal M1-B7-1/F/clone F7 cells could cure 67% of mice previously injected with a lethal number of M1 cells. These results emphasize that multiple exposures of irradiated B7-1-transduced myeloid leukemic cells can induce protective and therapeutic immunity against leukemia and that B7-1-mediated gene therapy may have therapeutic efficacy for patients with acute myelocytic leukemia.

Animals↗

PubMed1997

Expansive lumbar laminoplasty for degenerative spinal stenosis in patients below 70 years of age.

We reviewed the clinical and radiological results of patients with lumbar degenerative spinal stenosis who underwent expansive laminoplasty with a mean follow-up term of 5.6 years. Twenty-seven patients underwent open-door-type expansive lumbar laminoplasty, which has both decompression and stabilization effects. Clinical results were assessed based on the score system devised by the Japanese Orthopaedic Association (JOA score). The number and causes of repeat surgery were also evaluated. Radiological changes, such as degenerative scoliosis and spondylolisthesis, were evaluated at the operated levels and at levels L1-L5. There was marked recovery of clinical symptoms assessed by pre- and postoperative JOA score. Nearly 80% of patients obtained good or excellent results. Only one patient (4%) required additional surgery, which involved discectomy at the caudal level of the laminoplasty. Radiographic evaluation revealed that postoperative changes of spondylolisthesis and scoliosis were slight both in the expanded area and the L1-L5 levels. Range of motion of the disc space angle in the expanded area showed a significant decrease postoperatively. However, pre- and postoperative radiological changes showed no significant correlation with JOA score changes and repeat surgery. In conclusion, lumbar fusion after posterior decompression in active patients with spinal stenosis offers satisfactory clinical results concomitantly with a relatively small risk of repeat surgery.

Age Factors↗

PubMed1997

Significance of the localization of large granules in the thyrogonadotrophs of the musk shrew (Suncus murinus).

In order to examine the significance of small round and large granules in the thyrogonadotrophs of the musk shrew, we investigated the differences of numbers, distribution patterns and/or immunoreactivities of the large granules in the thyrogonadotrophs among the newborn, infant and adult musk shrews. As a result, we observed that the thyrogonadotrophs exist in newborn musk shrew, but the large granules were few in number and immunoreactivity on the granules was weak. The ratio of the number of large granule-containing cells to all LH beta positive cells was very low (6.2%) in newborn musk shrew, but high (98.2%) in adult male animals. We assume that thyrogonadotrophs of newborn shrews may not yet synthesize active beta-subunits, that the synthesis of beta-subunits is gradually increased with aging, and excessive products of beta-subunits may be stored in the large granules. It is known that female musk shrews are induced ovulators; therefore, we investigated morphological changes in the large and small granules in the thyrogonadotrophs at the LH surge which occurs after mating. We observed that the small granules were markedly decreased in number, or had almost vanished, 2 h after mating, but that the large granules still remained. Consequently, we assume that the large granules may be storage sites of excessive products of beta-subunits in older animals. On the other hand, small granules (release type granules) may be exhausted by release of a large quantity of gonadotrophin 2 h after mating, and this acute exhaustion of small granules may induce a sharp depression of the LH surge.

Amino Acid Sequence↗

PubMed1997

Rapid progression of chronic myelomonocytic leukemia following diaminodiphenyl sulphone treatment for dermatitis herpetiformis.

A 41-year-old patient with dermatitis herpetiformis (DH) developed steroid-resistant blebs as a sign of exacerbating DH. The skin symptoms were resolved after 2 weeks of oral administration of diaminodiphenyl sulphone (DDS). However, 3 weeks after the start of DDS, he suffered from edematous eruption on the cheeks and neck, enlargement of the pharynx, systemic lymphoadenopathy and hepatomegaly. In addition, his leukocyte count increased rapidly from 10.1 x 10(9)/l with 13% monocytes just before the start of DDS, to 24.6 x 10(9)/l with 28% monocytes. Bone marrow aspirate showed trilineage dysplasia and chronic myelomonocytic leukemia (CMML) was diagnosed. The patient died from septic shock during neutropenia following cytotoxic chemotherapy. In this case, CMML was complicated with DH and the administration of DDS accelerated the progression of CMML with the manifestations of DDS syndrome. Although DDS is a well-established drug for DH, DDS should be used with great caution when a hematological malignancy coexists.

Adult↗

PubMed1997

Generation and characterization of rat monoclonal antibodies against human serum amyloid A.

Monoclonal antibodies against human serum amyloid A (SAA) were generated in rat (which seems not to have mature SAA proteins) by immunizing intact human SAA. Thirteen clones selected by initial screening were analysed based on reactivity with synthetic peptides of SAA and with carboxyl-terminal truncated recombinant SAA. Antibodies were divided into four types, i.e. those recognizing the area around residue 18, 30, 90, and 100, respectively, of SAA. The antibody to the carboxyl terminus (around residue 100) of SAA, when subjected to immunohistochemistry for amyloid deposits in specimens from patients with reactive amyloidosis, always yielded negative reactivity, supporting the general concept that the carboxyl terminus of SAA is absent from human AA deposits.

Amino Acid Sequence↗

PubMed1997

A quantitative assessment of serum chylomicron by light scattering intensity: application to the intestinal fat absorption test.

A novel fat absorption test to clarify the malabsorption syndrome was developed using a micronephelometric technique and compared with the classic conventional technique using 131I-triolein. An integrity of time-sequential light scattered from chylomicron-related turbidity in serum was determined between 0 and 300 min after butter fat load, being expressed in terms of the light scattering intensity (LSI). A good correlation was obtained between LSI and the serum level of chylomicron-triglyceride determined by an ultracentrifugation technique (r = 0.819, P < 0.001). The maximal LSI was consistently observed at 180 min after administration of a test meal in the normal group (n = 39), whereas the malabsorption syndrome group (n = 35) was distinctly different and could be further classified according to four patterns of LSI changes. In addition, an inverse correlation was found between this fat absorption test and the 131I-triolein absorption test. It was concluded that the micronephelometric technique which does not use a radionuclide is advantageous in its simple and safe evaluation of fat malabsorption syndrome.

Adult↗

PubMed1997

Transcytotic vesicle fusion with canalicular membranes is modulated by phospholipid species: implications for biliary lipid secretion.

Phospholipid species modulate bile metastability and the subselection of such species for biliary secretion occurs at the canalicular membrane. In this study, the role of phospholipid head groups and hydrophobic indices in transcytotic vesicle fusion with the canalicular membrane inner leaflet was investigated using rat canalicular membrane vesicles (CMV) and liposomes. The CMV were purified from Sprague-Dawley rat liver, and small unilamellar vesicles (SUV) of phosphatidylserine (PS), phosphatidylcholine (PC) and mixtures of PS/PC (1:1, 2:1 and 4:1) were labelled with 8 mol% of octadecyl rhodamine B chloride (R18). The PC species used in this study were egg yolk PC (EYPC), soybean PC (SBPC), dipalmitoyl PC (DPPC) and dilinoleoyl PC (DLPC). Fusion of SUV with CMV was initiated by the addition of a millimolar concentration of Ca2+ and the degree of fusion was estimated by the increase of R18 fluorescence. Ca(2+)-dependent fusion of SUV consisting of PS, and PS/PC (4:1) with CMV was observed (PS > PS/PC; 4:1), whereas no detectable fusion was evident between CMV and SUV of PC alone or PS/PC (1:1 or 2:1). The rank order of fusibility between CMV and SUV of PS/PC (4:1) containing various PC species was PS/DLPC > PS/SBPC > PS/EYPC > PS/DPPC. The hydrophobic index of PC as determined by high performance liquid chromatography (HPLC) was related closely to liposome fusibility (r = -0.88). These results suggest that transcytotic vesicle fusion with the canalicular membrane inner leaflet is regulated by the phospholipid hydrophobicity of the vesicles.

Animals↗

PubMed1997

Protective and therapeutic immunity against leukemia induced by irradiated B7-1 (CD80)-transduced leukemic cells.

B7 molecules provide an important costimulatory signal for T cell receptor/CD3-mediated T cell activation via binding to their cognate receptors, CD28 and CTLA-4. We have introduced B7-1 (CD80) into M1 cells, spontaneously-occurred mouse myelocytic leukemic cells and assessed its potential in the induction immunity to leukemia cells. Syngeneic, immunocompetent SL mice receiving polyclonal B7-1-transduced M1 cells showed prolonged survival than control mice. Two independent B7-1-transduced monoclonal sublines, M1-B7-1+ (F20) and M1-B7-1+ (F7), were rejected in 100% an 50% of SL mice, respectively. In vivo depletion of T cell subsets showed that both CD4+ and CD8+ T cells were indispensable for the B7-1-dependent anti-leukemic immunity. Although a single exposure to irradiated monoclonal M1-B7-1+ cells were not fully effective, multiple exposures induced protective immunity against subsequent challenge with M1 cells. Furthermore, hyperimmunization with irradiated monoclonal M1-B7-1+ (F7) cells could partly cure mice previously injected with a lethal number of M1 cells. Although other groups have demonstrated that live, proliferating B7-1-transduced leukemic cells can improve antitumor immunity, this is the first report which shows that irradiated B7-1-transduced myeloid leukemic cells can induce protective and therapeutic immunity against leukemia.

Animals↗

PubMed1996

A conserved cysteine residue in the runt homology domain of AML1 is required for the DNA binding ability and the transforming activity on fibroblasts.

The AML1 gene encodes DNA-binding proteins that contain the runt homology domain and is found at the breakpoints of t(8;21), t(3;21), and t(12;21) translocations associated with myelogenous leukemias. AML1 heterodimerizes with PEBP2beta/CBFbeta, resulting in the enhanced affinity with DNA. The runt homology domain is responsible for binding with DNA and heterodimerizing with PEBP2beta/CBFbeta. AML1 is suggested to perform a pivotal role in myeloid cell differentiation, whereas it can cause neoplastic transformation when overexpressed in fibroblasts. In this study, we demonstrated that the reducing reagent, dithiothreitol (DTT), markedly enhances the DNA binding of AML1 expressed in COS7 cells. Oxidation by diamide or modification by N-ethylmaleimide of the free sulfhydryl residues inhibited the interaction of AML1 with DNA. The diamide effect was reversible with excess of DTT, whereas DTT could not restore the DNA binding of AML1 treated with N-ethylmaleimide. Site-directed mutagenesis of the amino acid residue 72, a highly conserved cysteine in the runt homology domain of AML1, to serine almost completely abolished DNA binding without altering the interaction with PEBP2beta/CBFbeta. This substitution also impaired transactivation through the consensus DNA sequence and transformation of fibroblasts induced by AML1b. These data indicate an essential role of the conserved cysteine residue in DNA binding of AML1, and it is possible that the redox state of AML1 could contribute to the regulation of its function.

3T3 Cells↗

PubMed1996

Sensitive plaque assay and propagation of Chuzan (Kasba) virus, a Palyam serogroup orbivirus, in BHK-21 cells.

Various factors influencing plaque formation of Chuzan virus in BHK-21 cell monolayers were studied and a practical method for plaque assay was developed. On addition of trypsin (5 micrograms/ml) and/or diethylaminoethyl (DEAE)-dextran (50 micrograms/ml) to the virus diluent as the virus adsorption medium and agar overlay medium, the number of plaques increased. When 100 micrograms/ ml DEAE-dextran was added to the diluent and overlay medium, plaques were produced in about 10-fold higher numbers than without trypsin and DEAE-dextran. Based on these results, a practical plaque assay method for Chuzan virus was established. Using this method, one-step growth of Chuzan virus was performed at an input multiplicity of 25 plaque-forming units (PFU) per cell. Cytopathic effects were first observed at 7.5 h post-inoculation (p.i.), and were complete at 12 h p.i. The titre of cell-associated virus, after gradual decline during the first 3 h of incubation, showed a rise within 4.5 h p.i. and a rise to a plateau of 10(6.3)PFU/0.2 ml at 12 h p.i. By indirect immunofluorescence, virus-specific antigen was detected in the cytoplasm of the cells at 4.5 h p.i., and all the cells fluoresced at 6 h p.i. Haemagglutination activity was first detected in infected whole cultures at 7.5 h p.i. reaching a plateau of 1:64 at 15 h p.i. Plaque formation and haemagglutination by the virus were specifically inhibited by antisera against the original and the plaque-cloned virus.

Animals↗

PubMed1996

Malignant fibrous histiocytoma of the lateral wall of the orbit.

A 58-year-old male presented with malignant fibrous histiocytoma originating from the lateral wall of the orbit, manifesting as left exophthalmos and diplopia on left lateral gaze. Magnetic resonance (MR) imaging demonstrated the tumor extending into the left orbit and under the temporalis muscle. The tumor was isointense with muscle on T1-weighted MR images and was surrounded by a low-intensity rim, which was proved to be the capsule after histological examination. The tumor was completely removed after detaching the lateral orbital rim and zygomatic arch using the dismasking flap method. He underwent one course of CYVADIC chemotherapy and has demonstrated no recurrence for 1 year and 6 months postoperatively.

Female↗

PubMed1996

Expression of costimulatory molecules in human leukemias.

In order to determine the indication of B7 (B7-1 and B7-2) molecules-mediated immuno-gene therapy for human leukemias, we investigated 94 human leukemic samples for the expression of MHC molecules required for tumor antigen-specific signals and of B7-1, B7-2, and ICAM-1 molecules required for non-specific costimulatory signals. All samples were strongly positive for MHC class I and 84% for class II antigen. B7-1, B7-2 and ICAM-1 were expressed in 5%, 22% and 16% of the total cases, respectively. Especially in 54 AML samples, B7-1 was only expressed in one case, while B7-2 was detected in as many as 15 cases (28%). We have also examined 13 human myelo/monocytic cell lines for the expression of class II and costimulatory molecules and found that significant expression of costimulatory molecules was induced in human leukemic cells by some suitable drugs, among which interferon-gamma (IFN-gamma) was the most potent inducer. Our results indicate that when the B7-mediated immuno-gene therapy was applied to human leukemias, especially to AML, B7-1 was rather preferable to B7-2 in that the latter was more widely expressed on human leukemic cells. Furthermore, since gene-transfer systems occasionally accompany serious problems, it should be taken into account that costimulatory molecules on human myelo/monocytic leukemic cells could be induced ex vivo without the introduction of exogenous genes.

Antigens, CD↗

PubMed1996

Distribution of alpha- and beta-subunits of glycoprotein hormones in thyrogonadotroph in the anterior pituitary cells of the musk shrew (Suncus murinus).

In order to examine the distribution pattern of alpha- and beta-subunits of glycoprotein hormones in small and large granules in the thyrogonadotrophs of the musk shrew, we used an antiserum against a synthesized peptide consisting of the sequence 37-53 of the rat alpha-subunit, which is highly conservative among several mammalian species, and also antisera to LH beta, FSH beta and TSH beta. Both alpha- and LH beta-subunits were colocalized in what appeared at the light-microscopic level to be the same cells, and the population ratio of alpha- and LH beta-subunit immuno-reactive cells was almost equal within each group of animals. In addition, we also demonstrated thyrogonadotrophs in the infant musk shrew as well as in the adult. Concerning small and large granules in thyrogonadotrophs of the musk shrew, we could observed small granules immunoreactive for only the alpha-subunit, for the LH beta-subunit and for both the alpha- and LH beta-subunits; while only the LH beta-subunit was observed in the large granules and the alpha-subunit was absent. Consequently, we propose that the large granules observed in the thyrogonadotrophs of the musk shrew may be storage sites for beta-subunits and are not secretory-type granules.

Aging↗

PubMed1995

Molecular cloning of the human glucose-regulated protein ERp57/GRP58, a thiol-dependent reductase. Identification of its secretory form and inducible expression by the oncogenic transformation.

Recently it was shown that putative phospholipase C-alpha cDNA does not code for an isotype of the phospholipase C superfamily but for one of the glucose-regulated proteins (GRPs), ERp57/GRP58. We have isolated human ERp57/GRP58 cDNA from human placenta. Sequence analysis showed that ERp57/GRP58 has two Trp-Cys-Gly-His-Cys-Lys motifs completely conserved among the mammals. Bacterially expressed recombinant ERp57/GRP58 protein contained a thiol-dependent reductase activity which was completely abolished when Ser residues were substituted for Cys residues in both of the two motifs. Furthermore, we have identified a soluble form of ERp57/GRP58 by Western blotting and biosynthetic labeling. In v-onc transformants of normal rat kidney cells, the expression level of ERp57/GRP58 was elevated at the protein level. In NIH3T3 cells transformed with v-src, activated c-src (Y527F) or c-src, the expression level of ERp57/GRP58 was upregulated in proportion to their transforming abilities. These results indicate that a soluble form of ERp57/GRP58 exists and that this protein may control both extracellular and intracellular redox activities through its thiol-dependent reductase activity. Moreover, it is likely that ERp57/GRP58 is involved in the oncogenic transformation.

3T3 Cells↗