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Biomedical subjects

H Harada

Publications and source records attributed to H Harada.

At least 163 records · Page 9Linked to original sources
PubMed2000

[Sarcoidosis associated with lupus pernio and acute pulmonary cavitation].

Lupus pernio, an uncommon skin condition due to sarcoidosis in Japan, is a chronically persistent, violaceous skin lesion primarily involving the nose, cheek, ears, and fingers. It has often been associated with chronic fibrotic non-resolving pulmonary sarcoidosis. We reported a case of sarcoidosis associated with lupus pernio and primary pulmonary cavitation as a rare manifestation in the lung. A 44-year-old man visited our hospital in January 1986 because of a 3-year history of swollen and violaceous cheeks (lupus pernio) and an 8-year history of erythema in both upper and lower limbs. The biopsy specimen obtained from the skin lesion revealed epithelioid cell granulomas without any evidence of Mycobacterium or fungal growth. Serum ACE (45.4 U/ml) was elevated. Chest X-ray films and computed tomographic (CT) scans showed bilateral hilar lymphadenopathy, nodules, multiple small opacities, and reticulo-linear opacities. Gallium scintigraphy demonstrated abnormal uptake in the mediastinal and hilar lymph nodes and lung fields. The patient had not received corticosteroids. Chest X-ray films and CT scans in July 1989 showed increased opacities and cavitation. Because pyogenic bacteria and acid-fast bacilli were not detected by repeated sputum examinations or bronchial washing, we concluded that the cavitary lesions were manifestations of primary pulmonary cavitation due to sarcoidosis. Prednisolone (40 mg daily) was prescribed and the dosage was gradually tapered. The lung lesions gradually resolved and have not recurred.

Adult↗
PubMed2000

[Methods of single-nucleotide polymorphism analysis and application to hereditary cancer syndrome].

Single-nucleotide polymorphism analysis is important in all areas of molecular biology. The causative genes of hereditary cancer syndrome have been isolated. Recently, molecular diagnosis of hereditary cancer syndrome has been performed using methods of single-nucleotide polymorphism analysis and the usefulness has been reported. It is considered that progression of molecular biology will be able to contribute to diagnosis (especially pre-symptomatic diagnosis), prevention and treatment of hereditary cancer syndrome in the future.

Humans↗
PubMed2000

Three-phase bone scintigraphy and viability of vascularized bone grafts for mandibular reconstruction.

Three-phase bone scintigraphy was undertaken to check the anastomotic patency and monitor the viability of vascularized bone grafts. Ten consecutive patients who underwent vascularized bone grafting of the mandible were reviewed. A successful clinical outcome was achieved in 8 patients. The graft failed in 2 patients. In this series, 3-phase bone scintigraphy of radiolabeled (99m)Tc-methylene-diphosphonate was performed at 7 days, and at 1, 3, 6, and 12 months after reconstruction. Assessments made using 3-phase bone images were compared with the clinical findings. The clinical outcome of the cases presented in our series correlated extremely well with 3-phase bone images. Three-phase bone scintigraphy is a useful method for the assessment of patency and viability of vascularized bone grafts. The use of this method can be very helpful in assessing the anastomotic patency and viability of a graft which for clinical reasons is suspected of being non-viable.

Aged↗
PubMed2000

[Successful allogeneic bone marrow transplantation following fungal liver abscess treatment in a patient with chronic myeloid leukemia in blastic crisis].

A 40-year-old man was diagnosed as having chronic myeloid leukemia (CML) in December 1990 and received busulfan and hydroxyurea. He developed myeloid blast crisis in February 1996. After DCMP combination chemotherapy, his disease reverted to chronic phase, but right hypochondrial pain developed and low-grade fever persisted. Abdominal CT scan revealed multiple low-density areas in the liver, suggestive of abscess formation. Grocott staining of a liver biopsy sample revealed granuloma and fungus. The patient was treated with intravenous amphotericin B (AMPH-B) without success. AMPH-B was then administered via a catheter placed in the portal vein on January 6, 1997, and an additional catheter placed in the hepatic artery on March 28. AMPH-B was administered through both catheters for more than two months, but later substituted by fluconazole because of renal impairment. On September 10, allogeneic bone marrow transplantation from the patient's HLA-identical brother was performed, despite persistence of the abnormal CT findings. Acute grade III GVHD developed, but there was no evidence of reactivation of the liver abscesses. This case demonstrates that a prior fungal liver abscess is not an absolute contraindication for BMT if prophylactic antifungal drugs are administered and careful observation is conducted.

Adult↗
PubMed1999

A functional and quantitative mutational analysis of p53 mutations in yeast indicates strand biases and different roles of mutations in DMBA- and BBN-induced tumors in rats.

In order to analyze the mutational events and to understand the biological significance of the p53 gene in chemical carcinogenesis, we applied a new yeast-based p53 functional assay to ovarian tumors induced by 7, 12-dimethylbenz[a]anthracene (DMBA), as well as to transitional cell carcinomas of the urinary bladder induced by N-butyl-N-(4-hydroxybutyl) nitrosamine (BBN) in rats. The assay demonstrated that 15 of 19 DMBA induced tumors harbored clonal p53 mutations, which is consistent with the expectations of the "clonal expansion" hypothesis. The majority of the mutations were purine (AG) to pyrimidine (CT) transversions (12/19) on the non-transcribed (sense) strand (NTS), which is likely to be due to depurination created by DMBA adduct formation on the NTS. In contrast, we found no pyrimidine to purine [corrected] transversion on the NTS. After cessation of BBN treatment, BBN-induced multifocal lesions in the bladder contained heterogeneous p53 mutations at an early stage. In the later stage, however, clonal p53 mutations were identified in 4 out of 7 bladders analyzed, conforming with the concept of "field cancerization". The observed base substitutions were G-->A (1/6) or C -->T transitions (2/6), and mutations at T (3/6) on the NTS in clonal mutations, together with non-clonal mutations, showing a preference of C-->T to G-->A (17 vs. 0). Thus, preferential repair was found in the transcribed strand of the p53 gene, whether modified by DMBA or by BBN carcinogens. Very similar mutation patterns were observed between clonal and non-clonal mutations in the DMBA- and BBN-induced tumors, indicating that the rat yeast p53 functional assay can be a potential tool for the characterization of in vivo mutation patterns of p53, when modified by chemical carcinogens.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1999

Localization of putative stem cells in dental epithelium and their association with Notch and FGF signaling.

The continuously growing mouse incisor is an excellent model to analyze the mechanisms for stem cell lineage. We designed an organ culture method for the apical end of the incisor and analyzed the epithelial cell lineage by 5-bromo-2'-deoxyuridine and DiI labeling. Our results indicate that stem cells reside in the cervical loop epithelium consisting of a central core of stellate reticulum cells surrounded by a layer of basal epithelial cells, and that they give rise to transit-amplifying progeny differentiating into enamel forming ameloblasts. We identified slowly dividing cells among the Notch1-expressing stellate reticulum cells in specific locations near the basal epithelial cells expressing lunatic fringe, a secretory molecule modulating Notch signaling. It is known from tissue recombination studies that in the mouse incisor the mesenchyme regulates the continuous growth of epithelium. Expression of Fgf-3 and Fgf-10 were restricted to the mesenchyme underlying the basal epithelial cells and the transit-amplifying cells expressing their receptors Fgfr1b and Fgfr2b. When FGF-10 protein was applied with beads on the cultured cervical loop epithelium it stimulated cell proliferation as well as expression of lunatic fringe. We present a model in which FGF signaling from the mesenchyme regulates the Notch pathway in dental epithelial stem cells via stimulation of lunatic fringe expression and, thereby, has a central role in coupling the mitogenesis and fate decision of stem cells.

Ameloblasts↗
PubMed1999

Isolation and characterization of the distal promoter region of mouse Cbfa1.

Cbfa1 is an essential transcription factor for bone formation, and as such little is known about the region responsible for the transcriptional regulation of this gene. Here we report the determination of the transcription start sites, isolation and partial characterization of distal promoter region of this gene. Three transcription start sites were identified by the 5'-Cap site method, recently invented for rapid examination of the 5'-end of genes of interest. A reporter construct containing 1.8 kb of 5' of transcription start sites had approximately 25-fold more luciferase activity than the promoter-less vector in osteoblastic cell lines. Deletion analysis of the reporter construct demonstrated that the minimal region to express promoter activity lies between bp -168 and -99, taking the most downstream transcription start site as +1. By Northern blot analysis, mRNA expression from the distal promoter was detected in the differentiated osteoblastic cell lines, UMR-106, ROS17/2.8 and MC3T3-E1, but not in cell lines of immature phenotype or originated from other organs. Luciferase activity was strongest in UMR-106 and ROS17/2.8, and weakest in COS-1 and HepG2, which are cell lines originating from other organs, corresponding to the level of mRNA expression. These results demonstrated that the distal promoter region examined here is important for tissue- and cell-type-specific gene expression of Cbfa1.

Animals↗
PubMed1999

Polymorphisms in the SOD2 and HLA-DRB1 genes are associated with nonfamilial idiopathic dilated cardiomyopathy in Japanese.

To reveal genetic risk factors of nonfamilial idiopathic cardiomyopathy (IDC) in Japanese, polymorphisms in the SOD2 and HLA-DRB1 genes were investigated in 86 patients and 380 healthy controls. There was a significant excess of homozygotes for the V allele [Val versus Ala (A allele), a polymorphism in the leader peptide of manganese superoxide dismutase at position 16] of the SOD2 gene in the patients compared with the controls (87.2% versus 74.7%, odds ratio = 2.30, p = 0.013, pc < 0.03), and a significant increase in the frequency of HLA-DRB1*1401 in the patients was confirmed (14.0% vs 4.5%, odds ratio = 3.46, p = 0.001, pc < 0.03). A two-locus analysis suggested that these two genetic markers (SOD2-VV genotype and DRB1*1401) may play a synergistic role in controlling the susceptibility to nonfamilial IDC. In addition, processing efficiency of Val-type SOD2 leader peptide in the presence of mitochondria was siginificantly lower than that of the Ala-type by 11 +/- 4%, suggesting that this lower processing efficiency was in part an underlying mechanism of the association between the SOD2-VV genotype and nonfamilial IDC.

Adolescent↗
PubMed1999

Lymph node metastasis is associated with allelic loss on chromosome 13q12-13 in esophageal squamous cell carcinoma.

Allelotype analysis of whole chromosomes showed that loss of heterozygosity (LOH) on 13q was exclusively associated with lymph node metastasis and poor prognosis in esophageal squamous cell carcinoma (ESC). To identify a locus responsible for lymph node metastasis, we performed fine deletion mapping on 13q by analyzing 60 ESCs with 18 polymorphic markers. Allelic loss was observed with at least one marker in 34 tumors (56.7%), and lymph node metastasis was significantly correlated with LOH (P = 0.0053). We found frequent loss at D13S260 (43.7%), D13S171 (38.6%), and D13S267 (43.6%) on 13q12-13. Among these markers, LOH at D13S171 showed a significant correlation with lymph node metastasis (P = 0.0441). Because these markers flank the BRCA2 gene, we intensively examined a mutation of the gene through all coding exons and exon-intron junctions by PCR-single-strand conformational polymorphism analysis under two different assays. We found only seven nucleotide substitutions as normal polymorphic changes; tumor-specific mutations were not detected, and loss of expression was not observed, indicating that the BRCA2 gene might not be a target of allelic loss in this region. Relatively frequent LOH was also found at the RB1 locus (34.7%), but a significant correlation with lymph node metastasis was not observed (P = 0.7430). Protein expression of RB1 was examined in 31 ESC cell lines, and loss of expression was infrequent (6.5%), indicating that inactivation of the RB1 gene might not be responsible for lymph node metastasis. Taken together, allelic loss at 13q12-13 of the primary ESC was closely associated with lymph node metastasis, and unidentified tumor suppressor gene(s) in this region might be involved.

Alleles↗
PubMed1999

Restoration of wild-type p16 down-regulates vascular endothelial growth factor expression and inhibits angiogenesis in human gliomas.

Recent studies have indicated that the loss of p16 is a frequent event in the progression of malignant gliomas. The loss of p16 promotes the acquisition of malignant characteristics in gliomas, which are among the most angiogenic of all human tumors. High-grade gliomas are distinguished from low-grade gliomas by intense angiogenesis in addition to their frequent loss of p16. New therapeutic strategies aimed at inhibiting tumor angiogenesis on the basis of molecular mechanisms are theoretically attractive. Here we evaluate the effect of p16 gene replacement on the angiogenesis of gliomas. Infection with a recombinant replication-defective adenovirus vector containing the cDNA of wild-type p16 significantly reduced the expression of vascular endothelial growth factor, which is thought to be a pivotal mediator of tumor angiogenesis, in p16-deleted glioma cells. Restoring wild-type p16 expression into p16-deleted glioma cells markedly inhibited angiogenesis induced by tumor cells in vivo. Furthermore, wild-type p16 inhibited neovascularization more potently than did wild-type p53 transfer. These findings indicate that the p16 gene plays an important role in the regulation of glioma angiogenesis, suggesting a novel function of the p16 gene.

Adenoviruses, Human↗
PubMed1999

Variation in the number of CAG repeats in the Machado-Joseph disease gene (MJD1) in the Japanese population.

Variation in the number of CAG repeats in the Machado-Joseph disease gene (MJD1) was examined by polymerase chain reaction and denaturing polyacrylamide gel electrophoresis analysis of 2134 normal and 135 affected chromosomes of Japanese individuals. The number of repeats ranged from 14 to 47 in normal alleles and from 61 to 84 in disease-associated alleles. The most frequent and lowest number of repeats was 14. The size distribution of normal MJD1 alleles did not fit a normal distribution curve, but was tetramodal. Repeats from 14 to 17, 18 to 23, 24 to 25, and 26 to 47 units were designated groups A through D, respectively. When examined Hardy-Weinberg equilibrium by chi-square analysis of goodness of fit: no evidence of significant deviation from the Hardy-Weinberg equilibrium was observed [x2=4.248<16.919 (P=0.05), df=9]. The observed distribution peak of normal MJD1 alleles corresponding to peptides containing 10, 15, 20, and 24 glutamine suggests that stretches of 5 and 10 glutamine might constitute a functional domain of human MJD1.

Adolescent↗
PubMed1999

Exacerbation of myasthenia gravis in a patient after interferon-beta treatment for chronic active hepatitis C.

We report the case of a 53-year-old female patient, who developed bilateral blepharoptosis, limb weakness, dysphagia, and dyspnea several days after human natural interferon-beta (IFN-beta) treatment for chronic active hepatitis C. A positive edrophonium test, an elevated anti-acetylcholine receptor antibody titer, and decrements in the amplitude of muscle action potentials evoked by repetitive stimulation confirmed the diagnosis of myasthenia gravis (MG). Since she had been suffering from drooping of her right eyelid, fluctuating diplopia and easy fatiguability of limbs before receiving IFN-beta, her symptoms of MG were considered to be exacerbated by IFN-beta. It is recommended that IFN-beta should be used with particular care in patients with known MG or its compatible symptoms.

Antiviral Agents↗
PubMed1999

Cbfa1 isoforms exert functional differences in osteoblast differentiation.

Cbfa1 is an essential transcription factor for osteoblast differentiation and bone formation. We investigated functional differences among three isoforms of Cbfa1: Type I (originally reported as Pebp2alphaA by Ogawa et al. (Ogawa, E., Maruyama, M., Kagoshima, H., Inuzuka, M., Lu, J., Satake, M., Shigesada, K., and Ito, Y. (1993) Proc. Natl. Acad. Sci. U. S. A. 90, 6859-6863), Type II (originally reported as til-1 by Stewart et al. (Stewart, M., Terry, A., Hu, M., O'Hara, M., Blyth, K., Baxter, E., Cameron, E., Onions, D. E., and Neil, J. C. (1997) Proc. Natl. Acad. Sci. U. S. A. 94, 8646-8651), and Type III (originally reported as Osf2/Cbfa1 by Ducy et al. (Ducy, P., Zhang, R., Geoffroy, V., Ridall, A. L., and Karsenty, G. (1997) Cell 89, 747-754). A reverse transcriptase-polymerase chain reaction analysis demonstrated that these isoforms were expressed in adult mouse bones. The transient transfection of Type I or Type II Cbfa1 in a mouse fibroblastic cell line, C3H10T1/2, induced the expression of alkaline phosphatase (ALP) activity. This induction was synergistically enhanced by the co-introduction of Xenopus BMP-4 cDNA. In contrast, the transient transfection of Type III cDNA induced no ALP activity. In C3H10T1/2 cells stably transfected with each isoform of Cbfa1, the gene expression of ALP was also strongly induced in cells transfected with Type I and Type II Cbfa1 but not in cells with Type III Cbfa1. Osteocalcin, osteopontin,and type I collagen gene expressions were induced or up-regulated in all of the cells stably transfected with each isoform of Cbfa1, and Type II transfected cells exhibited the highest expression level of osteocalcin gene. A luciferase reporter gene assay using a 6XOSE2-SV40 promoter (6 tandem binding elements for Cbfa1 ligated in front of the SV40 promoter sequence), a mouse osteocalcin promoter, and a mouse osteopontin promoter revealed the differences in the transcriptional induction of target genes by each Cbfa1 isoform with or without its beta-subunit. These results suggest that all three of the Cbfa1 isoforms used in the present study are involved in the stimulatory action of osteoblast differentiation, but they exert different functions in the process of osteoblast differentiation.

Animals↗
PubMed1999

Low p27 expression correlates with poor prognosis for patients with oral tongue squamous cell carcinoma.

BACKGROUND: p27, a cyclin-dependent kinase inhibitor, regulates progression from G1 to S phase. There have been a few clinical reports of low p27 expression associated with poor survival among patients with cancer; however, there have been no reports of such an association in cases of head and neck cancer. The authors investigated whether p27 expression in patients with oral tongue squamous cell carcinoma was associated with their prognosis. METHODS: Ninety-four patients with oral tongue squamous cell carcinoma were analyzed. The authors performed p27 immunohistochemistry on all patients and Western blot analysis on 19 available patients. Cox proportional hazards regression analysis that included gender, history of smoking and alcohol usage, presence of multiple primary cancers, stage, histologic grade, and p27 status was used to identify the multivariate predictive value of prognostic factors. RESULTS: Twenty-six patients had high p27 expression (> or =50% tumor cell nuclei positive), and 68 patients had low p27 expression (<50%) by immunohistochemistry. In those with low p27 expression, N(+) and advanced T (T3 or T4) were significantly higher than in those with high p27 expression (P = 0.02 and 0.04). The 5-year survival rate in the low p27 group was 44%, whereas that in the high p27 group was 68%, indicating a significant difference (P = 0.04). p27 expression was inferred from Western blot analysis, and an arbitrary quantity (<1, 1-5, or > or =5) from the ratio of tumor to normal tissue density was used to characterize, resulting in 8 (42%), 3 (16%), and 8 (42%) patients in the low (<1-fold), intermediate (1-5-fold), and high (> or =5-fold) groups, respectively. Results of immunohistochemical analysis for p27 were significantly correlated with those of Western blot analysis (P = 0.02). Multivariate analysis revealed that low intensity of p27 expression and advanced stage (Stage III or IV) were predictors of reduced survival (P = 0.02 and 0.001). CONCLUSIONS: Low p27 expression was associated with increasing lymph node metastasis and stage of tumor and resulted in a poor prognosis for patients with oral tongue squamous cell carcinoma. p27 is apparently a significant predictor of survival.

Actins↗
PubMed1999

Gas chromatographic-mass spectrometric determination of 4-nonylphenols and 4-tert-octylphenol in biological samples.

A simple and rapid method is described for the GC-MS determination of 4-nonylphenols (NOs) and 4-tert-octylphenol (OC) in biological samples. The NOs and OC in the sample are extracted with acetonitrile and the lipid in the sample extract is eliminated by partitioning between hexane and acetonitrile. After Florisil PR column clean-up, the sample extract is analyzed by GC-MS in the selected ion monitoring (SIM) mode. Average recoveries in pale chub (fish) and corbicula (shellfish) are 86.0 and 93.4% for NOs, and 95.8 and 96.4% for OC, respectively, spiked at the levels of 1.0 microg of NOs and 0.1 microg of OC per 5 g of fish and shellfish samples. The detection limits are 20 ng/g for NOs and 2 ng/g for OC.

Animals↗
PubMed1999

In vitro susceptibility of Helicobacter pylori to trifluoromethyl ketones.

Heteroaromatic trifluoromethyl ketones (TFMK's) showed strong inhibitory activity against Helicobacter pylori. The MIC50 observed for 2-trifluoroacetonylbenzoxazole (1) is 20-fold more active than metronidazole and is only twice as high as that of clarithromycin. The inhibitory mode of TFMK's on Hp growth was not related to inhibition of urease.

Benzoxazoles↗