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Biomedical subjects

H Harada

Publications and source records attributed to H Harada.

At least 325 records · Page 18Linked to original sources
PubMed1995

Bipolar affective disorder associated with beta-thalassemia minor.

A family suggesting cosegregation of beta-thalassemia minor and bipolar affective disorder was reported. The monogenic hereditary anemia was surveyed over three generations in this family, and three patients with the beta-thalassemia and the bipolar affective disorder were observed over two generations. The localization of a gene responsible for bipolar affective disorder was discussed on the basis of previous reports.

Bipolar Disorder↗
PubMed1995

Secondary structure and folding topology of the DNA binding domain of interferon regulatory factor 2, as revealed by NMR spectroscopy.

The secondary structure elements of the DNA-binding domain of mouse interferon regulatory factor 2 [IRF-2(113)] were determined by heteronuclear multidimensional NMR spectroscopy. The sequential NOE connectivities, amide proton exchange rates, and 3JHN alpha coupling constants indicated the presence of three alpha-helical regions and four short beta-strands connected through relatively long loops. The long range NOEs indicated the four strands form an antiparallel beta-sheet and the three alpha-helices form a bundle on the sheet. The arrangement of the secondary structure elements and the overall folding topology resemble those of the DNA binding domains of bacterial activator CAP, heat shock transcription factors, and fork-head proteins, although there is no sequence homology among them.

Amino Acid Sequence↗
PubMed1995

Possible involvement of the transcription factor ISGF3 gamma in virus-induced expression of the IFN-beta gene.

Two virus-inducible transcription factors, IRF-1 and IRF-2 have been identified as an activator and a repressor, respectively, of the type I interferon (IFN) genes. Recent studies with mice carrying null mutations for the IRF-1 or IRF-2 alleles have revealed the existence of IRF-1-dependent and -independent pathways mediating IFN-beta gene induction. Here we report that the expression of an IRF family member ISGF3 gamma is induced upon viral infection in IRF-1-/-, IRF-2-/- embryonic fibroblasts. Furthermore, ISGF3 gamma can bind to a virus-inducible promoter element in the IFN-beta gene. These results suggest that ISGF3 gamma or complex containing ISGF3 gamma is involved in the IRF-1-independent pathway mediating IFN-beta gene regulation.

Amino Acid Sequence↗
PubMed1995

Mexiletine and lidocaine reduce post-ischemic functional and biochemical dysfunction of perfused hearts.

The present study was undertaken to determine whether class Ib antiarrhythmic agents, mexiletine and lidocaine, exert beneficial effects on ischemia/reperfusion-induced cardiac contractile dysfunction. Isolated rat hearts were subjected to 35-min global ischemia, followed by 60-min reperfusion and the functional and metabolic alterations were examined with and without mexiletine or lidocaine treatment. Ischemia/reperfusion resulted in a lack of recovery of contractile function, a sustained rise in left ventricular end-diastolic pressure and increased coronary perfusion pressure of the perfused heart during reperfusion. Contractile dysfunction was associated with increases in tissue Na+ and Ca2+ levels, decreases in K+ and Mg2+ levels, and release of creatine kinase and purine nucleosides and bases (ATP metabolites) from the heart. Treatment of the perfused heart with either 10-100 microM of either mexiletine or lidocaine during pre-ischemia resulted in an enhancement of post-ischemic contractile recovery, a suppression of changes in tissue Na+, K+, Ca2+ and Mg2+ contents and an attenuation of the release of creatine kinase and ATP metabolites in an almost concentration-dependent manner. Tissue sodium accumulation was observed at the end of ischemia, which was also attenuated by pretreatment with these agents. The prevention of Na+ overload and accompanying Ca2+ overload in cardiac cells may be the mechanism underlying the improvement of post-ischemic contractile function of perfused hearts by these agents.

Adenosine Triphosphate↗
PubMed1995

Transcriptional activity of a fluorinated vitamin D analog on VDR-RXR-mediated gene expression.

The transcriptional activity of the hexafluorinated derivative of 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3], 26,26,26,27,27,27-hexafluoro-1,25-dihydroxyvitamin D3 [F6-1,25-(OH)2D3], was examined in cultured cells by a transient expression assay (CAT assay) using expression vectors for the rat nuclear vitamin D3 receptor (VDR) and the rat 9-cis-retinoic acid receptor (RXR beta), and a reporter plasmid containing a consensus vitamin D3 response element (VDRE) consisting of two directly repeated AGGTCA motifs spaced by 3 bp (DR3). At physiological concentrations, the transcriptional activity of F6-1,25-(OH)2D3 was 2-4 times more potent than that of 1,25-(OH)2D3 in both nontarget (HeLa) and target (UMR106) cells for 1,25-(OH)2D3. The transcriptional activity of F6-1,25-(OH)2D3 was also higher when the endogenous target gene (osteopontin), which has a VDRE related to the DR3 in its promoter, was induced. A gel-shift assay using DR3 as a probe and in vitro synthesized receptors showed that the ligand-induced DNA binding of VDR required RXR to form a heterodimer. Moreover, in this assay we found that F6-1,25-(OH)2D3 induced the receptor-DNA complex at a 10-fold lower concentration than 1,25-(OH)2D3 without influencing the dissociation kinetics. However, the binding affinity of F6-1,25-(OH)2D3 for VDR was slightly lower than that of 1,25-(OH)2D3. The increased DNA binding of ligand-bound VDR by introducing hexafluorines into 1,25-(OH)2D3 may potentiate the transcriptional activity. Thus, the higher biological activity of F6-1,25-(OH)2D3 may be exerted at least in part by enhanced transcriptional activity.

Animals↗
PubMed1995

Seton treatment for perianal Crohn's fistulas.

In this study, we evaluated the efficacy of long-term seton drainage in the management of 13 patients with severe perianal Crohn's fistulas which had proven to be intractable to conventional therapy. After adequate curettage of the fistulous tracts and infected tissue, either a Penrose drain or a fine polyethylene catheter was inserted to encircle the tracts and tied. Patients were followed up for a mean period of 12.1 months. Perianal pain disappeared or improved in all 13 patients, while the body temperature of all 7 with pyrexia dropped to within the normal range. Discharge disappeared or diminished in 77% (10/13) and tenderness disappeared or improved in 77% (10/13). Induration disappeared or improved in 69% (9/13). Overall, good results were achieved in 10 patients, although 3 required redrainage. In one of these patients, a good result was achieved after colostomy was performed for active intestinal disease. Nevertheless, 2 patients did not improve, one of whom required lay-open surgery after seton treatment. In 8 of the 13 patients, some seton drains were able to be removed, and none of the patients experienced any soiling or leakage. Thus, we conclude that seton treatment is worthwhile in the management of perianal Crohn's fistulas as it alleviates the symptoms and simplifies multiple tracts. Moreover, it preserves sphincter function, is less invasive, and can be managed easily.

Adult↗
PubMed1995

Regulation of the interferon system and cell growth by the IRF transcription factors.

Induction of gene transcription in response to extracellular stimuli constitutes an essential aspect of host defense mechanisms. Interferons (IFN) are families of cytokines that have been discovered and extensively characterized in the context of host defense against viral infections. In elucidating the mechanism of transcriptional induction of the IFN genes by viruses, we have discovered two structurally related transcription factors, Interferon regulatory factor 1 (IRF-1) and IRF-2. These two factors, however, function not only as regulators of the IFN system, but are also key transcription factors in the regulation of cell growth and apoptosis. Thus, these studies uncover a complex gene transcription network in which the fate of cellular responses is determined by how the IRF transcription factors function in conjunction with other factors on the promoters of distinct genes under different conditions of the cells.

3T3 Cells↗
PubMed1995

Irritant and protective action of urea-urease ammonia in rat gastric mucosa. Different effects of ammonia and ammonium ion.

The effects of urea-urease-ammonia on the rat gastric mucosa were examined and compared with those of NH4OH and NH4Cl. The mucosal application of urea with urease produced a reduction in potential difference (PD) in a dose-related manner for urea, and a significant drop was observed by > 0.1% urea in the presence of 100 units urease. Such PD reduction was also observed when the mucosa was exposed to either NH4OH (> 0.03%) or NH4Cl (> 1%); delta PD (20 mV) caused by 0.3% NH4OH and 3% NH4Cl was equivalent to that induced by 0.5% urea+urease (100 units). The combined oral administration of urea (approximately 6%) and urease (100 units) did not induce any macroscopic damage in the gastric mucosa. NH4Cl given orally had no or little effect on the mucosa at any dose levels even at 10%, while NH4OH given orally caused hemorrhagic lesions in the mucosa at the dose of > 0.3%. In contrast, both urea+urease and NH4Cl given prior to HCl/ethanol protected the gastric mucosa against damage in a dose-related manner, and a significant effect was obtained by urea at > 0.5% and by NH4Cl at > 1%. NH4OH was also effective in reducing the severity of HCl/ethanol-induced gastric lesions at lower dose (0.3%). The protective effect of urea+urease was attenuated significantly by prior administration of indomethacin or coadministration of hydroxyurea, while that of NH4Cl or NH4OH was mitigated by indomethacin.(ABSTRACT TRUNCATED AT 250 WORDS)

Ammonia↗
PubMed1995

Development of a new invasion and metastasis model of human oral squamous cell carcinomas.

A new model was devised in order to establish an in vivo model for oral carcinoma that exhibits significant local invasion and metastasis. One hundred and fifty-two nude mice had tumour cells from one of two established oral squamous cell carcinoma (SCC) cell lines (OSC-19 and OSC-20) implanted into the tongue or the oral floor via an intra-oral route and, as a control, the subcutaneous tissue of the back. The back tumours showed an expansive growth pattern, lacking significant invasion of surrounding tissues. In contrast, the tumours implanted into the tongue or the oral floor exhibited invasive growth and the histological appearance was similar to that of the original tumours. Moreover, regional neck lymph node and pulmonary metastases were observed in this model. Regional neck lymph node metastases were detected in 81.0% of mice implanted with OSC-19 cells and in 13.6% of mice implanted with OSC-20 cells. OSC-19 and OSC-20 cells showed pulmonary metastases in 9.5 and 9.1% of mice, respectively. These results suggest that this intra-oral implantation model is valuable in the study of the mechanism of invasion and metastasis of oral SCC.

Animals↗
PubMed1995

DNA typing of HLA class II genes in Japanese patients with dilated cardiomyopathy.

HLA class II genes (DRB, DQA, DQB, DPA, and DPB) were typed at the DNA level using polymerase chain reaction/sequence-specific oligonucleotide probe analysis in 78 unrelated patients with DCM and 336 unrelated healthy controls to elucidate the HLA alleles or HLA haplotypes associated with DCM. The frequencies of DRB1*1401 (15.4% v 4.5%, RR = 3.90, P < 0.0005, Pc < 0.03), DQB1*0503 (14.1% v 5.4%, RR = 2.93, P < 0.007) and DRB1*1401-DQB1*0503 haplotype (11.5% v 1.5%, RR = 8.24, P < 0.00001, Pc < 0.01) were increased in the DCM patients. The frequency of HLA-DRB1*1101 (9.0% v 3.0%, RR = 3.26, P < 0.02) also was increased in the patients. In addition, the frequencies of DQB1*0604 and DPB1*0401 were increased in the DRB1*1401 and DRB1*1101 negative patients. In contrast, the frequencies of DQB1*0303 (19.2% v 30.7%, RR = 0.55, P < 0.05) and DRB1*0901-DQB1*0303 haplotype (16.7% v 29.8%, RR = 0.49, P < 0.02) were decreased in the DCM group. Disease susceptibility to DCM in the Japanese population, thus, may be controlled in part by a gene (or genes) in close linkage disequilibrium with DRB1*1401-DQB1*0503, DRB1*1101-DQB1*0301, and DQB1*0604-DPB1*0401 haplotypes, while the resistance to DCM may be associated with the DRB1*0901-DQB1*0303 haplotype.

Adolescent↗
PubMed1995

A device for controlling odorant stimulation and olfactory evoked responses in humans.

We developed a device for odorous stimuli control to record olfactory evoked responses from the human scalp. The characteristics of the apparatus are as follows. Translating the subject's respiration into electric signals with a sensor attached to the nose. The period and timing of odorous stimuli could be adjusted, so that stimuli could be synchronous with respiration. The interstimulus interval could be arbitrarily selected once every 1 to 9 respiration(s) so that adaptation could be prevented. We obtained evoked responses to odorous stimuli using this apparatus from the human scalp, whose positive peak latencies were approximately 350 and 700 msec. Such responses were not recorded if oxygen stimuli were used instead of odorous stimuli or with click sounds produced by the switching electromagnetic valve. Three types of odorant evoked scalp potentials were obtained in normal human subjects. The first type consisted mainly of two positive peaks with a peak latency of about 350 msec (P350) and about 700 msec (P700). The second type and the third type consisted of only one positive peak with a peak latency of about 350 msec and 700 msec, respectively. Such a P350 or P700 peak as that observed in the normal subjects was not detected in anosmic patients.

Electric Stimulation↗
PubMed1995

Congenital teratoid cyst of the floor of the mouth--a case report.

A case of sublingual congenital teratoid cyst is reported and the recent literature is reviewed. Histopathologic study of the enucleated cyst revealed striated muscle, cartilage, fat, salivary gland tissue, and gastrointestinal epithelium in a cyst wall of dense fibrous tissue with a thin layer of ciliated columnar and partially stratified squamous epithelium.

Adipose Tissue↗
PubMed1995

Tonsillar lipoma: a case report.

Benign tumours of the tonsils are rare. Only a few cases of tonsillar lipoma have been previously reported. The case of a pedunculated polypoid lipoma of the palatine tonsil in a 44-year-old Japanese woman is presented. The 'polyp' was excised and an histopathological examination was carried out. The 'polyp' contained dilated lymphatics in the dense fibrous connective tissue beneath the overlying mucosal epithelium and below the mature fat tissue with intervening strands of fibrous tissue.

Adult↗
PubMed1995

Pancreatic stone protein and lactoferrin in human pancreatic juice in chronic pancreatitis.

Lactoferrin and pancreatic stone protein (PSP) are thought to be closely related to pancreatic stone formation in chronic pancreatitis. However, the results reported so far have not been conclusive. To reevaluate the pathological importance of PSP in chronic pancreatitis, compared to lactoferrin, levels of PSP were determined by applying an immunoassay specific to PSP to pure pancreatic juice taken from a total of 52 patients. The patients consisted of 16 controls, 19 chronic pancreatitis patients (13 noncalcified and 6 calcified), and 17 probable cases of pancreatitis. The monoclonal antibody PSP antagonist used in the study recognizes both forms of the protein, PSP S1 and S2-5, with equal effectiveness. No significant reduction of PSP was observed in either calcified (mean +/- SEM, 111 +/- 30 micrograms/mg and 24 +/- 3 micrograms/mg protein) or noncalcified (305 +/- 133 and 97 +/- 47) chronic pancreatitis patients compared with controls (85 +/- 23 and 34 +/- 16). PSP levels did not decrease, at least not in the complete forms of the protein found in chronic pancreatitis. PSP antibody and assay results indicated that a reduction of PSP S2-5 alone could not be ruled out in chronic pancreatitis either.

Adult↗
PubMed1995

Differences in the expression of pemphigus antigens during epidermal differentiation.

Epidermal desmogleins with molecular weights of 130/140 kDa (Dsg3 or PVA) and 150/160 kDa (Dsg1 or DGI) are recognized by autoantibodies from patients with pemphigus vulgaris (PV) and pemphigus foliaceus (PF), respectively. In order to understand the histogenesis of both types of pemphigus, we studied the expression patterns of Dsg1 and Dsg3 during stratification of cultured keratinocytes. Monolayers of cultured normal human keratinocytes demonstrated uniform intercellular staining with PV sera. The staining pattern was distinct from the focal staining with PF sera observed only in the stratified areas. Both Dsg1 and Dsg3 proteins and their mRNA were expressed by the monolayers, whereas no production of Dsg2 (HDGC) mRNA was found. The relative ratio of Dsg3 to the total desmogleins, as determined by density on immunoblotting, decreased as the cultured keratinocytes stratified. In the completely stratified keratinocytes cultured on collagen membrane, Dsg1 became predominant, with subsequent reduction of PV antigen expression. The relative decrease of Dsg3 (PVA) during epidermal differentiation might be responsible for the induction of suprabasal acantholysis in PV.

Autoantigens↗
PubMed1995

Diversity of immunobiological functions of T-cell lines established from patients with adult T-cell leukaemia.

In order to understand the variety of HTLV-1-associated cutaneous diseases, we studied the cytological profile of HTLV-1-infected T-cell lines established from patients with adult T-cell leukaemia (ATL). Among four CD4+ cell lines, termed 16T(-), 35T(-), MH-1, and KS-2, the 16T(-) cells secreted elevated quantities of IL-4, IL-6 and IFN-gamma and expressed mRNA for each cytokine in the absence of exogenous stimulation. The 35T(-) cells secreted IL-6 and a small amount of IFN-gamma, but not IL-4. The MH-1 and KS-2 cells secreted only IL-6 in the absence of stimulation. In response to stimulation with phorbol-12-myristate-13 acetate (PMA), the 16T(-) cells produced more IL-4 and IFN-gamma, whereas the 35T(-) and MH-1 cells exhibited increased secretion of IFN-gamma, but still no IL-4 or IL-4 mRNA production. Although neither IL-4 nor IFN-gamma were found in the culture supernatant of KS-2 cells, the production of IL-4 mRNA was detected by RT-PCR. Culture supernatants from the 16T(-) and 35T(-) cells induced the expression of intercellular adhesion molecule-1 (ICAM-1) and HLA-DR by cultured keratinocytes. This response was inhibited by pretreatment of the supernatant with anti-IFN-gamma antibodies. These results indicate that some HTLV-1-infected T-cell lines constitutively secrete various cytokines, including biologically active IFN-gamma. The diversity of immunobiological functions of the T-cell lines may be related to the variety of clinical features present in ATL patients.

Adult↗
PubMed1995

A specific chromosome abnormality of t(4;12)(q11-12;p13) in CD7+ acute leukaemia.

Three cases of acute leukaemia with t(4;12) (q11-12;p13) karyotypic abnormalities were analysed. They had the following common clinical and biological characteristics: (1) dysplasia of three haemopoietic lineages: (2) absent or low myeloperoxidase activity: and (3) retention of platelets in the peripheral blood and megakaryocytes in the bone marrow. There were increased numbers of basophils in the bone marrow and peripheral blood in two of the cases. In all, the blast cells displayed the unique immunophenotype CD7+CD13+CD34+HLA-DR+. The blasts analysed in one case expressed c-kit on the membrane surface. These findings suggest that the t(4;12) (q11-12;p13) abnormality is associated with a particular type of acute leukaemia, one in which the morphology and immunophenotype suggest that the translocation may have occurred at an early stage of haemopoiesis.

Acute Disease↗