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Biomedical subjects

H Harada

Publications and source records attributed to H Harada.

At least 361 records · Page 20Linked to original sources
PubMed1995

[Measurement of anti-acetylcholine receptor antibody using human rhabdomyosarcoma cell line].

We developed a radioimmunoassay for AChR Ab using AChR solubilized from membrane extracts of human rhabdomyosarcoma cell line (RD cell). The binding affinity of this AChR to the alpha-Bungarotoxin (alpha-BTX) was similar to that of AChR from cell surface. Lyophilized AChR was stable within two months at -20 degrees C. In our assay system, sera from patients with Myasthenia Gravis (MG) showed markedly high titers and frequency (94%) of anti-AChR Ab. On the other hand, almost all sera from normal and non-myasthenic patients such as rheumatoid arthritis and thyroid disease were negative (< 0.2nmol/l). Our assay using AChR from RD cells shows sufficient results in the intra- and inter-CV values, and recovery and dilution tests. AChR Ab titers of our assay showed good correlations with those measured by AChRs from both human ischemic muscles and TE671 cells (commercial kit). The radioimmunoassay for AChR Ab using the membrane extracts of RD cells has high sensitivity, specificity and stability. Therefore, the assay is valuable as the routine assay for the diagnosis of MG.

Autoantibodies↗
PubMed1995

Surgery for Crohn's anal fistulas.

The aim of this study was to analyze the features of Crohn's anal fistulas and to evaluate the efficacy of seton treatment. In 119 patients with Crohn's disease, the incidence of anal fistula was 56% (67/119), with no significant difference in the incidence among patients with ileitis, colitis, and ileocolitis. "Intractable" anal fistulas were found in 17% of patients with ileitis, compared to 64% of those with colitis (P = 0.051) and 68% of those with ileocolitis (P = 0.014). Seton treatment, i.e., non-cutting, long-term seton drainage, was performed for 21 patients (5 with intersphincteric, and 16 with transsphincteric fistulas). In the 16-month follow up, 9 patients required redrainage for recurrent fistulous abscess, mainly because of progressive colorectal disease. Finally, a good result was obtained in 17 of the 21 patients (81%) and no recurrent fistulous abscess developed in the 8 patients in whom all setons were removed. Anal continence was preserved in all the patients. These results indicate that anal fistulas with Crohn's ileitis were cured more easily than those with colitis or ileocolitis, and that seton treatment was effective for intersphincteric fistula with multiple fistula openings and for transphincteric fistulas in patients exhibiting remission of intestinal Crohn's disease.

Crohn Disease↗
PubMed1995

Characteristics of Roman character input in Japanese word processing on keystroke interval time.

This study clarifies the characteristics of the time keys that are taken to enter Roman letters for Japanese sentences. First, test the appearance frequency of two consecutive characters of the alphabet in the input of English sentences and in the input of the Roman characters of Japanese sentences. Based on these results, we analyzed the features of stroke frequency of the keys in the Roman character input. Based on the result of the analysis, we clarified the features of the keystroke interval time for two consecutive characters in the Roman character input. Then, keys were struck to enter Japanese sentences for a fixed period of time and a test was made for the characteristics. As a result, the following points were clarified: 1) The time keys struck were divided into two large groups. One for two consecutive alphabet letters that corresponded to Kana, or the Japanese syllabary, and the other with no correspondence. The former had smaller values for the mean time and deviations, and the latter had larger values for them. 2) The subjects who struck a larger number of keys per unit time took less time in typing two consecutive letters which did not correspond to Kana.

Adult↗
PubMed1995

Comparative study on the muscular load of the arms using hair driers.

The purpose of the present study was to evaluate the muscular load of the arm when combing the hair using different "kuru-kuru" type of hair driers. Ten female students (20-24 years old) volunteered as subjects. Five combing patterns were conducted as follows: 1) comb outer layer of right side of hair using right hand, 2) comb outer layer of left side of hair using right hand, 3) comb inner layer of left side of hair using right hand, 4) comb outer layer of back hair using right hand, and 5) comb inner layer of right side of hair using left hand. Surface EMGs were recorded from M. flexor carpi ulnaris, M. brachioradialis, M. biceps brachii, M. triceps brachii, M. deltoideus and M. trapezius of both sides of body. Integrated EMGs (iEMGs) were used to evaluate muscular load for each of the seven different types of hair driers used. The relationship between iEMGs and weight, center of gravity, diameter, length, and circumference of each hair drier were examined. The weight of hair driers tended to be the effective factor on the muscular load. Muscular load also had a tendency to be affected by the shape of the grips. With regard to the hand size, the longer the thumb length, the smaller is the muscular load. It was suggested that a relatively large diameter of the bulb-shaped grip of the drier gave a smaller muscular load among the hair driers examined in the present experiment.

Adult↗
PubMed1994

Involvement of the IRF-1 transcription factor in antiviral responses to interferons.

The mechanisms underlying interferon (IFN)-induced antiviral states are not well understood. Interferon regulatory factor-1 (IRF-1) is an IFN-inducible transcriptional activator, whereas IRF-2 suppresses IRF-1 action. The inhibition of encephalomyocarditis virus (EMCV) replication by IFN-alpha and especially by IFN-gamma was impaired in cells from mice with a null mutation in the IRF-1 gene (IRF-1-/- mice). The IRF-1-/- mice were less resistant than normal mice to EMCV infection, as revealed by accelerated mortality and a larger virus titer in target organs. The absence of IRF-1 did not clearly affect replication of two other types of viruses. Thus, IRF-1 is necessary for the antiviral action of IFNs against some viruses, but IFNs activate multiple activation pathways through diverse target genes to induce the antiviral state.

Animals↗
PubMed1994

Cellular commitment to oncogene-induced transformation or apoptosis is dependent on the transcription factor IRF-1.

The transcriptional activator interferon regulatory factor 1 (IRF-1) and its antagonistic repressor IRF-2 are regulators of the interferon (IFN) system and of cell growth. Here we report that embryonic fibroblasts (EFs) from mice with a null mutation in the IRF-1 gene (IRF-1-/- mice) can be transformed by expression of an activated c-Ha-ras oncogene. This property is not observed in EFs from wild-type or IRF-2-/- mice but is still observed in EFs from mice deficient in both genes. The transformed phenotype of ras-expressing IRF-1-/- EFs could be suppressed by the expression of the IRF-1 cDNA. Thus, IRF-1 functions as a tumor suppressor. Furthermore, expression of the c-Ha-ras oncogene causes wild-type but not IRF-1-/- EFs to undergo apoptosis when combined with a block to cell proliferation or treated by anticancer drugs or ionizing radiation. Hence, IRF-1 may be a critical determinant of oncogene-induced cell transformation or apoptosis.

Animals↗
PubMed1994

Possible gene dose effect of a mutant cardiac beta-myosin heavy chain gene on the clinical expression of familial hypertrophic cardiomyopathy.

We have examined for a mutation in the cardiac beta myosin heavy chain gene from Japanese patients with familial hypertrophic cardiomyopathy. A missense mutation due to a G to A transition in codon 935, leading to a replacement of Glu with Lys, was found in one patient. Family members of this patient were then examined. It was revealed that both the proband and his elder brother, who was also a symptomatic patient, were homozygous for the mutation. The proband eventually died of intractable heart failure, and his brother died suddenly in their thirties. On the other hand, his parents, who were first cousins and heterozygous for the mutation, had cardiac hypertrophy without clinical symptoms. His elder sister was also heterozygous for the mutation, however, she did not manifest with cardiac hypertrophy. These observations suggest a gene-dose-like effect of the mutant cardiac beta myosin heavy chain gene on the clinical manifestation of familial hypertrophic cardiomyopathy.

Adenine↗
PubMed1994

Requirement for transcription factor IRF-1 in NO synthase induction in macrophages.

Production of nitric oxide (NO) by macrophages is important for the killing of intracellular infectious agents. Interferon (IFN)-gamma and lipopolysaccharide stimulate NO production by transcriptionally up-regulating the inducible NO synthase (iNOS). Macrophages from mice with a targeted disruption of the IFN regulatory factor-1 (IRF-1) gene (IRF-1-/- mice) produced little or no NO and synthesized barely detectable iNOS messenger RNA in response to stimulation. Two adjacent IRF-1 response elements were identified in the iNOS promoter. Infection with Mycobacterium bovis (BCG) was more severe in IRF-1-/- mice than in wild-type mice. Thus, IRF-1 is essential for iNOS activation in murine macrophages.

Amino Acid Oxidoreductases↗
PubMed1994

K+ ionophores inhibit nerve growth factor-induced neuronal differentiation in rat adrenal pheochromocytoma PC12 cells.

Incubation with a K+/H+ ionophore nigericin attenuated the nerve growth factor (NGF)-induced neurite outgrowth in rat pheochromocytoma PC12 cells. However, a Na+/H+ ionophore monensin and a Ca2+ ionophore A23187 did not inhibited the neurite outgrowth. Nigericin also inhibited the NGF-caused induction of acetylcholinesterase and suppression of cell proliferation. These changes were dependent on the amount of the ionophore added to the culture. In addition, a distinct K+ ionophore, valinomycin, similarly inhibited the NGF-induced neuronal differentiation. These results suggest the presence of the K+ ionophore-sensitive mechanism in the NGF-induced differentiation system in PC12 cells.

Acetylcholinesterase↗
PubMed1994

Evaluation of tumor-associated antigen (2H6 antigen) in detecting early stages of gastric cancer.

A sandwich enzymed-linked immunosorbent assay (ELISA) was developed by using monoclonal antibody 2H6 (2H6 MoAb). MoAb 2H6 could be used to detect the 2H6 antigen in the sera of several cancers, showing positive rates of 65.4%, 66.7%, 47.4%, 80.0%, 45.2% and 16.7% in gastric cancer, hepatocellular carcinoma, cancers of the colon, esophagus, breast and pancreas, respectively. On the other hand, the positive rates in benign diseases or healthy donors were 3.4%, 3.4%, 4.2%, 8.3%, 6.9%, and 1.2% in myasthenia gravis, polymyositis, gastritis, gastric ulcer, other benign diseases and normal healthy donors, respectively. Fifty-two patients with gastric cancer were investigated in detail. The positive rates of serum 2H6 antigen, CEA, AFP, CA19-9 and CA125 in patients with gastric cancer were 65.4%, 9.6%, 2.3%, 25.0% and 8.1%, respectively. Among these tumor markers, serum 2H6 antigen levels alone were significantly elevated in patients with early stage (I and II) gastric cancer. Furthermore, combining the measurement for serum 2H6 with CA19-9 increased the percentage of gastric cancer slightly. No correlation between 2H6 antigen and these other tumor markers was observed. The serum levels of 2H6 antigen were monitored post-surgically in 11 patients for 12 weeks and they were found to diminish gradually. The findings suggest that the measurement of serum 2H6 antigen may be a useful marker for an early stage of gastric cancer.

Adolescent↗
PubMed1994

Detection of Epstein-Barr virus genes in malignant lymphoma with clinical and histologic features of cytophagic histiocytic panniculitis.

T-cell proliferative disorders are occasionally associated with Epstein-Barr virus (EBV) infection. This study was designed to assess the clinical features of cutaneous lymphomas positive for EBV genes. Polymerase chain reaction was used to detect EBV genes in tissue or blood samples from patients with malignant lymphoma or related diseases. Of 26 DNA samples tested, EBV genes were detected in two samples, both of which were obtained from the same patient with subcutaneous T-cell lymphoma showing clinical and histologic features of cytophagic histiocytic panniculitis. On the basis of these findings, we conclude that EBV infection may be related to cutaneous lymphoma with hemophagocytic manifestations.

Adolescent↗
PubMed1994

Traumatically induced posterior disk displacement without reduction of the TMJ--a case report.

A case of posterior disk displacement (PDD) without reduction of the temporomandibular joint (TMJ) was observed in this case report. The disk position was altered by using an occlusal splint and intermaxillary elastic traction for 10 days. An anterior displaced disk with reduction (ADDw/R) resulted from this therapy. Proposed criteria for diagnosing the PDD without reduction of the TMJ will be discussed in this study.

Adult↗
PubMed1994

Sarcomere dynamics in a spontaneous contraction wave and its effect on the following, electrically triggered twitch in rat myocyte. Comparison with the rested state twitch.

A spontaneous contraction (SC) wave propagates among sarcomeres in heart muscle by the mechanism of Ca(++)-induced release of Ca++ from sarcoplasmic reticulum (SR). In the present study, some characteristics of unloaded shortening during the SC and its effect on a subsequent, electrically triggered twitch (Tsc) were examined at a sarcomere level in isolated rat myocytes. The results were compared with those of a rested state twitch (RS), which was accompanied by an action potential. Average shortening velocity from onset to peak of shortening was 3.74 +/- 1.25 (mean +/- SD, n = 18) and 5.35 +/- 2.30 microns/s per sarcomere (n = 54) in SC and RS, respectively. That the former was smaller than the latter (P < 0.01, t test) suggests that Ca++ are released from the SR more slowly in the SC than the RS. There were no differences in either the extent or area of shortening between SC and RS. The extent of shortening increased significantly as shortening velocity increased in all the SC (P < 0.05), RS, Tsc, and triggered twitch (Trs) after the RS (P < 0.001 in the last three). The slope of the line for the regression of the extent upon the velocity of shortening in the SC was approximately 1.5 times greater than the other three. This suggests that the SC has a different time course of change of myoplasmic [Ca++] and therefore a different mode of the causal SR Ca++ release from the electrically triggered twitches (RS, Trs, Tsc). There were positive correlations between the extent and the area of shortening in each of the RS (P < 0.01), the Trs (P < 0.05), and the Tsc (P < 0.001), but not in SC. The slope of the line for the regression of the extent upon the area of shortening in the Tsc was about three times greater than those in the RS and the Trs, suggesting characteristics of the Tsc from different those of the RS and the Trs. An SC inhibited a Tsc in an interval-dependent manner. The shortening velocity in the Tsc recovered fully at a test interval of approximately 0.6 s between the onsets of the two successive contractions. The velocity increased further with further increasing the test interval (up to 0.9 s). At a test interval of 0.8-0.9 s, the shortening velocity in the Tsc was greater than those in the preceding SC and the corresponding Trs by 1.17- and 1.80-fold, respectively, as compared in the same five sarcomeres.(ABSTRACT TRUNCATED AT 400 WORDS)

Action Potentials↗
PubMed1994

Monoclonal antibodies reacting with the mucin-specific lectin from Sambucus sieboldiana (SSA-M).

Monoclonal antibodies (MAbs) were prepared against the mucin-specific lectin from Sambucus sieboldiana (SSA-M). The majority of MAbs reacted with both free SSA-M and SSA-M bound to porcine mucin. However, MAbs SS16, SS18, and SS19 did not react with mucin-bound lectin, suggesting that these MAbs may react at or near the lectin binding site. Some MAbs also showed reactivity with lectins other than SSA-M (e.g. ConA, Pisum sativum, and Saphora japonica lectins) suggesting possible sequence homology between SSA-M and other lectins. These MAbs should be useful reagents for immunoaffinity purification of SSA-M, characterizing SSA-M structure and binding, and metabolic studies on mucins.

Animals↗
PubMed1994

Evaluation of cytology and tumor markers of pure pancreatic juice for the diagnosis of pancreatic cancer at early stages.

To evaluate the value of cytology of pure pancreatic juice (PPJ) and tumor marker determination in PPJ and serum for the diagnosis of early pancreatic cancer (EPC), PPJ was obtained endoscopically from 16 patients with EPC (< 20 mm, confined to pancreas), 16 patients with chronic pancreatitis (CP), and 20 controls. Cutoff levels of CEA, CA19-9, and POA in PPJ were set from ROC curves at 40 ng/ml, 7,500 U/ml, and 1.5 U/ml, respectively. For the differentiation of EPC from CP, the sensitivity of CEA, CA19-9, and POA was 71.4, 42.9, and 50%, respectively; specificity was 93.3, 46.7, and 80%, respectively; and diagnostic accuracy was 82.8, 44.8, and 65.5%, respectively. Determination of serum tumor markers was useless. Sensitivity of cytology was 75%, specificity was 93.8%, and diagnostic accuracy was 84.4%. Combined cytology and CEA determination in PPJ increased the diagnostic accuracy to 93.1%. The combination was useful in supporting and supplementing endoscopic retrograde cholangiopancreatography (ERCP) findings for the correct diagnosis in 11 and 4 patients, respectively, with EPC; in one patient EPC was correctly diagnosed on ERCP findings alone. One of 16 patients with CP showed false-positive results. We conclude that cytology and CEA determination in PPJ with ERCP is a useful combination for the diagnosis of pancreatic cancer even in early stages.

Antigens, Neoplasm↗