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Biomedical subjects

T Harada

Publications and source records attributed to T Harada.

At least 505 records · Page 28Linked to original sources
PubMed1994

Experimental study of microwave coagulation of a VX-2 carcinoma implanted in rabbit kidney.

This paper describes the results of an experimental study of the microwave coagulation of VX-2 renal tumors implanted in rabbits. The rabbits undergoing microwave treatment exhibited a satisfactory survival rate and a complete response to treatment, as verified by histological examination. All the rabbits receiving no treatment died within 6 weeks of implantation of the VX-2 carcinoma. These results indicate that microwave coagulation may be a curative method of treatment for a relatively small renal tumor. Intraoperative real-time ultrasonic scanning permits the percutaneous microwave coagulation of renal cancer in a clinical situation.

Animals↗
PubMed1994

Characterization of HCV structural proteins expressed in various animal cells.

Hepatitis C virus (HCV) is a main causative agent for transfusion-associated and sporadic cases of non-A, non-B hepatitis throughout the world. HCV has a positive-strand RNA of about 9,400 nucleotides as its genome, whose organization is similar to those of animal pestiviruses or human flaviviruses. In spite of the lack of an effective replication system in tissue culture cells, genes coding for viral proteins of HCV have been identified. The putative nucleocapsid (p22) and envelope (gp35 and gp60) proteins have been expressed in cells by different vectors under various foreign promoters. Furthermore, a truncated core protein and association of envelope proteins with nonstructural proteins have also been observed. These synthesized viral proteins have been shown to be useful for diagnostic assays.

Animals↗
PubMed1994

Molecular basis of beta-thalassemia in Japan: heterogeneity and origins of mutations.

Characterization of beta-thalassemia mutations was attempted for 13 unrelated Japanese patients heterozygous for beta-thalassemia. We have systematically analyzed beta-thalassemia genes using polymerase-chain-reaction-related techniques; dot blot hybridization with oligonucleotide probes complementary to known mutations, restriction endonuclease assay and direct sequencing of amplified genomic DNA. Seven different mutations were detected. Six of them are an amber mutation in codon 90 (GAG to TAG), a four-base-pair deletion in codons 41 and 42 causing premature termination due to frameshift, a C-T substitution at position 654 of IVS-2, a G-A substitution at position 1 of IVS-2 and a C-G substitution at position 848 of IVS-2, leading to splicing defects, and an ocher mutation (GAA-TAA) in codon 121 causing a thalassemia intermedia phenotype with inclusion body formation in erythrocytes. A silent mutation (CTG-TTG) was also detected in codon 91 of the allele with the IVS-2 position 1 mutation. These mutations have been reported previously in the Japanese population. The other mutation is a novel one in the Japanese, an amber mutation (TGG-TAG) in codon 15, causing a beta zero-thalassemia phenotype by premature termination of the beta-globin chain synthesis. We analyzed haplotypes of chromosomes bearing each beta-thalassemia mutation. Origins and a spectrum of mutations in comparison with those detected in malaria-endemic regions are discussed.

Adolescent↗
PubMed1994

Characterization of the amyloid fibril from primary localized cutaneous nodular amyloidosis associated with Sjögren's syndrome.

BACKGROUND: Primary localized cutaneous nodular amyloidosis (PLCNA) is a rare disease, and its pathogenesis of amyloid deposition is still unknown. OBJECTIVE: The purpose of this study was to know the origin of amyloid in PLCNA. METHODS: Water-soluble amyloid fibrils were isolated from the skin and resolved on SDS-PAGE, then subjected to immunoblot analysis. RESULTS: The major amyloid fibril protein was a 29-kD peptide which reacted with both anti-lambda- and anti-kappa-light-chain antibodies. CONCLUSION: Amyloids in this particular case of PLCNA are derived from the polyclonal immunoglobulin light chain and some cases of PLCNA could be reactive diseases rather than neoplastic ones.

Amyloid↗
PubMed1994

Clinical features of idiopathic bilateral sensorineural hearing loss.

The Research Committee of the Ministry of Health and Welfare in Japan has defined hearing loss of unknown etiology with fairly high-speed progression as idiopathic bilateral sensorineural hearing loss (IBSH). Its diagnostic criteria consist of the following: that it is (1) progressive, (2) with bilateral involvement, and (3) of unknown etiology. In this study, we evaluated the clinical course in 20 cases of IBSH. Many cases of IBSH finally showed symmetrical profound sensorineural hearing loss. The clinical course of IBSH consisted of various combinations of the following four states: (1) fixed hearing, (2) rapid progression, (3) pathological slow progression and (4) physiological slow progression.

Adolescent↗
PubMed1994

Protective role of intracellular superoxide dismutase against extracellular oxidants in cultured rat gastric cells.

We examined the role of intracellular superoxide dismutase (SOD) as an antioxidant by studying the effect of diethyldithiocarbamate (DDC) on extracellular H2O2-induced damage in cultured rat gastric mucosal cells. 51Cr-labeled monolayers from rat stomachs were exposed to glucose oxidase-generated H2O2 or reagent H2O2, which both caused a dose-dependent increase in 51Cr release. DDC dose-dependently enhanced 51Cr release by hydrogen peroxide, corresponding with inhibition of endogenous SOD activity. This inhibition was not associated either with modulation of other antioxidant defenses, or with potentiation of injury by nonoxidant toxic agents. Enhanced hydrogen peroxide damage by DDC was significantly prevented by chelating cellular iron with deferoxamine or phenanthroline. Inhibition of cellular xanthine oxidase (possible source of superoxide production) by oxypurinol neither prevented lysis by hydrogen peroxide nor diminished DDC-induced sensitization to H2O2. We conclude that (a) extracellular H2O2 induces dose dependent damage to cultured gastric mucosal cells; (b) intracellular SOD plays an important role in preventing H2O2 damage; (c) generation of superoxide seems to occur intracellularly after exposure to H2O2, but independent of cellular xanthine oxidase; and (d) cellular iron mediates the damage by catalyzing the production of more reactive species from superoxide and H2O2, the process which causes ultimate cell injury.

Animals↗
PubMed1994

Synthesis of the metabolites of clentiazem.

The metabolites of clentiazem in the urine or bile of rats and dogs were investigated. Fifteen basic, 6 acidic, 2 neutral and 4 conjugated metabolites were isolated. In the present paper, fourteen reference compounds as shown in Charts 1, 2 and 3 were synthesized to identify the structures of the metabolites in procedures fundamentally similar to those employed in the synthesis of the corresponding metabolites of diltiazem.

Animals↗
PubMed1994

Graft-versus-host reaction and GvH disease.

Chronic GvHR was induced by inoculating parental lymphoid cells into F1 hybrid mouse. Combination of ATL and ATH, which were congenic recombinant strains differing only in H-2I and S region from each other, was chosen to induce class II-GvHR. Selective activation against partner's alloantigen of graft CD4+ T cells was the primary event of the GvHR and then led to concomitant activation of both graft and host cells. Immune dysregulation among these cells made the GvHR-mouse express various chronic diseases including immune complex glomerulonephritis, autoimmune-like lesions of the liver or the salivary gland, tumor-like proliferations of T cells and abnormal extramedullary hematopoiesis. Chronic GvHR was also induced by a preferential but not a selective activation of graft CD4+ T cells. A combination of DBA/2 and C57BL/6, which differ in whole MHC antigens, was an example. When D2 cells, but not B6 cells, were incoulated into the BDF1 mouse, predominant activation of CD4+ cells over CD8+ cells were observed. Contributing factors to this phenomenon were low responsiveness of graft CD8+ T cells to allogeneic class I MHC antigens and anti-parent activity of host CD8+ cells. Thus both graft and host cells participate either actively or passively in the reaction induced in the parent --> F1 experimental system of GvHR/D.

Animals↗
PubMed1994

Acute tubular necrosis with loin pain and persistent multiple wedge-shaped contrast enhancement on CT.

A 38-year-old man had severe loin pain and computed tomography performed 48 hours later, after drip infusion pyelography (DIP), revealed wedge-shaped contrast enhancement. He showed mild impairment of renal function with no evidence of rhabdomyolysis. The loin pain lasted for 5 days and the wedge-shaped contrast enhancement on CT persisted for 14 days and improved. The case was compatible with the new syndrome, loin pain and persistent wedge-shaped contrast enhancement on CT, proposed by Ishikawa et al (Nephron 27: 31, 1981).

Adult↗
PubMed1994

Abducent nerve paralysis during interferon alpha-2a therapy in a case of chronic active hepatitis C.

A 59-year-old woman with chronic active hepatitis C was treated with recombinant human interferon alpha-2a. After three days of administration, the patient complained of diplopia with dizziness and head heaviness. Ophthalmic examinations revealed a disturbance of the movement of left eye ball to the outer side without any other neurological signs. The diplopia, which was diagnosed as abducent nerve paralysis, improved rapidly and reversed at about 6 weeks after discontinuation of interferon and during infusion of hydrocortisone. To our knowledge, this is the first report of abducent nerve paralysis associated with alpha-2a interferon.

Abducens Nerve↗
PubMed1994

The existence of protein kinase C in cone photoreceptors in the rat retina.

We examined the localization of protein kinase C (PKC) in the rat retina, using a monoclonal antibody against PKC. The PKC immunoreactivities were localized in bipolar cells as reported previously, and also in outer and inner segments (OS and IS) of photoreceptor cells. As the PKC immunoreactive OS and IS of photoreceptors were very few in number, we hypothesized that these were of cone photoreceptors. We then examined whether the PKC immunoreactive OS and IS were bound by peanut agglutinin which was shown to bind specifically to cone OS and IS. Almost all of the PKC immunoreactive OS and IS showed PNA binding.

Animals↗
PubMed1994

Audiological findings in glomus tumours.

Glomus tumours of the skull base are rare, but as they present with symptoms of hearing loss and tinnitus they are a clinical entity of which audiologists should be aware. This paper describes the findings of the major series of skull base glomus tumours found in the literature, and notes that the contribution of conductive and sensorineural components varies with tumour classification. The reported incidence of hearing loss and tinnitus in glomus tympanicum and glomus jugulare is reviewed and compared with the Cambridge series, in which two tumours were Fisch type A, four type B, two type C and five type D. In each case a mixed hearing loss was found, though the extent of sensorineural impairment was variable. The length of history of tumours limited to the middle-ear was far shorter (mean 8 months) than for more extensive lesions (type B, mean 64 months; C, 48 months; and D, 23 months). Eleven patients (85%) reported the symptom of hearing loss, and 12 (92.5%) of tinnitus, and some patients had experienced these symptoms for some time without seeking the advice of an otologist. It may be concluded that the presence of subjective pulsatile tinnitus or a retrotympanic mass should be considered an indication for an otological opinion, wherein the use of high resolution imaging techniques and arteriography will be considered in conjunction with detailed audiological assessment. Audiologists should be aware of the possibility of glomus tumour in such cases.

Adult↗
PubMed1994

Preferential adsorption of cationic anti-DNA antibodies with immobilized polyanionic compounds, dextran sulfate.

It has been shown that cationic anti-DNA antibodies have nephritogenic potential in murine models of lupus nephritis. More recently, we have reported that there is a close relationship between the presence of circulating cationic anti-DNA antibodies and the development of lupus nephritis in humans, and that the cationic anti-DNA antibodies bind to heparan sulfate, a major glycosaminoglycan in glomerular basement membrane, much better than neutral anti-DNA antibodies. This suggests that cationic anti-DNA antibodies of the IgG class may be responsible for development of nephritis in vivo in patients with systemic lupus erythematosus. In this study, we first studied reactivity of anti-DNA antibodies with a panel of glycosaminoglycans in vitro using ELISA methods, and found that anti-DNA antibodies cross-react with dextran sulfate, hyaluronic acid and chrondroitin sulfate. The reactivity and selectivity of dextran sulfate with anti-DNA antibodies was confirmed by in vitro immunoadsorption of the patient's sera with dextran sulfate-fixed column; incubation of auto-antibody-positive sera with dextran sulfate cellulose column removed anti-DNA, but not anti-RNP, anti-Sm, anti-SSA and anti-SSB antibodies from the sera in vitro. Of note is that dextran sulfate cellulose column absorbed exclusively, if not all, cationic anti-DNA antibodies in their sera. Nonspecific binding of total immunoglobulins as well as total proteins to the column was marginal. It has been suggested that cationic anti-DNA antibodies in sera of patients with refractory lupus nephritis could be efficiently removed by apheresis using dextran sulfate column.

Adolescent↗
PubMed1994

Pironetin, a novel plant growth regulator produced by Streptomyces sp. NK10958. I. Taxonomy, production, isolation and preliminary characterization.

A novel plant growth regulator, pironetin, was isolated from the culture broth of Streptomyces sp. NK10958. It was extracted from the culture broth with ethyl acetate and purified by column chromatographies. Pironetin showed 23% inhibition on the growth of rice plants without any loss of crop yield at 10 g/a on 9 days before heading.

Crystallography, X-Ray↗
PubMed1994

Trans-suppression of gene expression by hepatitis C viral core protein.

We have demonstrated that the truncated hepatitis C (HCV) core protein with its C-terminal hydrophobic domains deleted is translocated to the nucleus of transfected cells (22). In this study, intact and truncated core proteins of HCV were transiently expressed in a human hepatoblastoma cell line, HepG2, and their effects on the expression of the chloramphenycol acethyl transferase (CAT) gene driven by viral and cellular promoters were examined. The intact core protein of 22 kDa which is localized in the cytoplasm of the transfected cells suppressed the expression in all of the promoters tested. They were promoters of the SV40 early region, the c-fos oncogene, the retinoblastoma susceptibility gene, the beta-interferon gene and the beta-actin gene. In contrast, the truncated HCV core protein located in the nucleus did not show such a suppressive activity. The HCV core protein appears to function not only as a viral structural protein but as a regulator of gene expression and it might act as a suppressive factor for the cellular gene expression.

Antibodies, Viral↗
PubMed1994

Diagnosis of thyroid carcinoma by ultrasonic examination: comparison with diagnosis by fine needle aspiration cytology.

Ultrasonic examination was performed on 120 patients who later underwent surgery. Ultrasonically, among the 64 cases of benign nodules and the 56 of carcinomas, 50 and 46 cases respectively were diagnosed correctly. In making the ultrasonic diagnosis, the following findings were considered; shape, margin, boundary, internal echoes, hyperechoic spots, the echo level of the nodule and the cystic pattern. The sensitivity for carcinoma diagnosis was 0.82, specificity was 0.78 and accuracy was 0.80. The diagnostic accuracy for the same patients using a newly devised diagnostic system that utilized a fuzzy inference was almost as high as that of the conventional method. Furthermore, the diagnostic accuracy of both of these methods did not differ significantly from that obtained by fine needle aspiration cytology. Therefore, non invasive ultrasonic examination is considered to be very useful for the detection and diagnosis of thyroid carcinoma.

Biopsy, Needle↗
PubMed1994

The incidence of ground glass nuclei in thyroid diseases.

Ground glass nuclei are an important finding in the diagnosis of papillary carcinoma of the thyroid. However, they appear only in specimens in paraffin-embedded histological sections, and not in frozen sections or cytological specimens. This has led to the conclusion that they are an artifact of fixation and/or embedding. However, if this is the case, a question arises as to whether or not such an artifact can be of value as a definitive sign for establishing a diagnosis of papillary carcinoma. This study was undertaken to try to answer that question. 1) To confirm whether or not the author's microscopic observations were correct, we carried out automatic imaging analysis with the Interaktives Bild-Analysen System (IBAS). The author's microscopic observations were consistent with the data obtained by the IBAS. 2) Among 20 cases of papillary carcinoma, clear nuclei were observed in 11 cases (55%), and pseudoclear nuclei were noted in 20 cases (100%). When 1,000 papillary cancer cells were counted in 10 cases, the average incidences of clear nuclei and pseudoclear nuclei were found to be 0.51% and 18.3% respectively. Clear nuclei were seen in papillary carcinomas in all kinds of fixatives except one but were not seen in benign lesions. Even though ground glass nuclei are a type of artifact, we believe that their presence may be considered to be a characteristic feature of papillary carcinomas of the thyroid.

Adenoma↗