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Biomedical subjects

C Kobayashi

Publications and source records attributed to C Kobayashi.

At least 73 records · Page 4Linked to original sources
PubMed1995

Effects of early coronary reperfusion on the time course of signal-averaged electrocardiogram after myocardial infarction and its relation to late arrhythmic events, effects of early coronary reperfusion on signal-averaged ECGs.

The effect of early reperfusion on the time course of signal-averaged ECG was examined in 90 patients with myocardial infarction. Abnormal signal-averaged ECG disappeared more frequently (p < 0.05) and earlier in cases with early reperfusion than in those without. Serious arrhythmic events in the late phase (> 7 days) occurred in patients with abnormal signal-averaged ECG, but not in cases with early reperfusion. These results indicate that dynamic changes in tissue structure and the physiological state of viable muscles after early reperfusion produce different time courses for signal-averaged ECG. The risk of arrhythmic events among patients with abnormal signal-averaged ECG seems to be lower in cases with early reperfusion than in those without.

Aged↗
PubMed1995

[A clinical study of non-tuberculous pulmonary mycobacteriosis].

We studied the clinical features of sixty-one patients with non-tuberculous pulmonary mycobacteriosis (NTM), who were newly diagnosed at five national hospitals in Kinki area during 1993. The study subjects were composed of 31 patients with M. avium complex (MAC) disease (20 males and 15 females), 21 with M. kansasii (MK) disease (19 males and 3 females), 2 males with M. szulgai (MS) disease and 2 females with M. chelonae (MC) disease. The rate of NTM to all culture proven mycobacteriosis was 20.2% and the rate of NTM to all culture proven, newly discovered mycobacteriosis was 18.2% and the rates were higher than Sakatani's report in 1994 (14% in 1991). The ratio of MK to MAC was 22:35, and the ratio of MK was higher than the report of Sakatani. The mean age of patients with MK was 57.9 in male and 76.7 in female, that with MAC was 71.0 in male and 70.1 in female, that with MS was 57.0 in male and that 72.5 with MC in female. The proportion of elderly patients was higher than the former reports in Japan, especially in female with MK. The main lesions on chest X-ray was found in bilateral S1, 2(S1+2), particularly in the cases with cavitary lesions, but right middle lobe and left lingular lobe were mainly affected in some patients with MAC and S6 was often affected in elderly patients with MK. The chemotherapy with isoniazid, rifampicin, ethambutol and/or streptomycin (or kanamycin) w as highly effective in case with MK and MS disease, the efficacy was similar to pulmonary tuberculosis. Some patients with MAC were treated with combination of anti-tuberculosis drugs and new quinolons and/or clarythromycin, but the efficacy was not yet revealed.

4-Quinolones↗
PubMed1994

Distribution of Ia antigen-expressing nonlymphoid cells in various stages of induced periapical lesions in rat molars.

Periapical lesions were experimentally produced in rat lower first molars by exposing the pulp to the oral environment for 1 to 56 days. Temporal changes in the number and distribution of la antigen-expressing nonlymphoid cells in the periapical tissue were examined immunohistochemically on decalcified cryostat sections using OX6, a monoclonal antibody against rat la antigen. Influx of la-positive exudative cells into the periapical tissue was observed from 1 day postoperatively. Between 14 and 28 days when expansion of the periapical lesion was most evident, numerous la-positive macrophage-like and dendritic cell-like cells of diverse morphologies were found in the periapical tissue. The number of these cells showed further increase at 56 days postoperatively, when the lesion expansion had ceased. These results suggest the involvement of la antigen-expressing nonlymphoid cells in the development and perpetuation of periapical pathosis. They may act primarily as antigen-presenting cells, which are essential for the initiation of antigen-specific immune defense.

Animals↗
PubMed1994

New electronic canal measuring device based on the ratio method.

The most striking disadvantage of most apex locators is that if there are electrolytes in the canal the meter shows a reading which is too short or sometimes the measurement itself becomes impossible. To overcome this drawback, a new concept for electrically measuring the root canal length has been developed. The device simultaneously measures two impedances of the canal using current sources with two different frequencies. Then the ratio between the two electric potentials proportional to each impedance is calculated. The quotient is shown on the device's meter and represents the position of a file tip in the canal. The present study found that the quotient was only negligibly influenced by the electrolyte present in the canal and decreased considerably as the file tip approached the apical foramen.

Dental Pulp Cavity↗
PubMed1993

Cloning and characterization of a tryptophanase gene from Enterobacter aerogenes SM-18.

A tryptophanase gene from Enterobacter aerogenes SM-18 was cloned and sequenced. The structural gene for tryptophanase, tnaA, consisted of 1389 bp encoding 462 amino acid residues, and its nucleotide sequence and deduced amino acid sequence showed significant homology to those of tnaA from Escherichia coli K12. A short open reading frame consisting of 31 amino acid residues was found upstream of tnaA, and it showed some similarity to the E. coli tnaC gene known to be a cis-acting regulatory element for transcription. A partial open reading frame homologous to the 5' end of E. coli tnaB was observed at the 3'-flanking region of tnaA. These genes may thus constitute an operon as in E. coli.

Amino Acid Sequence↗
PubMed1993

Monoclonal antibody specific to virulence-associated 15- to 17-kilodalton antigens of Rhodococcus equi.

Virulent Rhodococcus equi produces 15- to 17-kDa surface protein antigens. These antigens are used as markers to identify virulent R. equi isolates from foals and their environment by Western blot (immunoblot) analysis with naturally infected foal serum. In the present study, a monoclonal antibody (MAb; 10G5) was generated against the 15- to 17-kDa antigens excised from sodium dodecyl sulfate-polyacrylamide gels to develop sensitive and specific immunoblot assays for the identification of virulent R. equi. MAb 10G5 strongly reacted with R. equi ATCC 33701 and L1, which expressed 15- to 17-kDa antigens by Western blot, colony blot, and dot immunobinding assays, but it did not react with strains ATCC 33701P- and L1P-, which lacked the antigens. For identification of virulent R. equi, clinical and environmental isolates were tested by these assays with the MAb, and all virulent strains were successfully identified; these strains possessed virulence plasmids. These results suggest that the MAb is a useful reagent for the identification of virulent R. equi.

Animals↗
PubMed1993

[Application of cyclosporin for cornea graft].

This study aimed to determine the optimal concentration rate of clinically effective Cyclosporin (CYA). Exchange penetrating keratoplasties were performed on 30 albino rabbits divided into 3 groups of ten, Groups I, II, and III, using 7 mm. trephine. In Group I 0.025% CYA drops were administered 4 times per day for 50 days and similarly 0.05% CYA drops were given in Group II. Only the solvent (alpha cyclodextrin), without any CYA, was applied to Group III, the control group, in the same manner. Suture removal and skin grafting were carried out on the 14th day after operation, as an additional means of sensitization. The 50-day post-operative rate of transparency retention was 40% for Group I, and 80% for Group II, and 20% for Group III, indicating that 0.05% CYA concentration was the most effective. In Experiment II, hetero-lamellar keratoplasties were performed on 16 albino rabbits to 8 Wistar rats, divided into Groups I and II. CYA (0.05% concentration) was applied 4 times a day for 50 days in Group I. Group II, the control group, was not treated. Both groups were followed for 100 days post operation. The 50-day post-operative rate of transparency retention of Group I was 71.4% and 12.5% for Group II. These figures also confirmed the effectiveness of 0.05% CYA. The results of our two experiments demonstrate that the application of 0.05% CYA would be most effective clinically.

Animals↗
PubMed1993

[A case of metastatic hepatocellular carcinoma of the superior mediastinum].

A 58-year-old man, who had undergone right hepatic lobectomy for hepatocellular carcinoma 6 years before, complained of hoarseness because of right recurrent laryngeal nerve paralysis. Chest X-ray film showed a large mass shadow in the superior mediastinum. On chest CT scan the mass was considered to be swollen paratracheal lymph nodes. Percutaneous aspiration biopsy of the mass demonstrated malignant epithelial cells. It was suspected that the hepatocellular carcinoma solitarily metastasized to the paratracheal lymph nodes. Right thoracotomy was done and the mediastinal tumor was resected. Microscopic examination of the resected specimen proved that the tumor was a metastatic hepatocellular carcinoma not of the lymph nodes, but of the fibroadipose tissue of the mediastinum. Metastasis of hepatocellular carcinoma to the mediastinal fibroadipose tissue is uncommon. To our knowledge, our case is the first report of hepatocellular carcinoma which shows such a metastasis.

Carcinoma, Hepatocellular↗
PubMed1992

An immunohistochemical study of the distribution of immunocompetent cells, especially macrophages and Ia antigen-expressing cells of heterogeneous populations, in normal rat molar pulp.

The precise distribution of various immunocompetent cells in rat molar pulp was immunohistochemically examined by use of seven anti-rat monoclonal antibodies. It was demonstrated that rat molar pulp contained many OX6 (anti-Ia antigen)-positive cells and a large number of ED1 (anti-monocytes, macrophages, and dendritic cells)-positive, ED2 (anti-tissue macrophages)-positive, and/or OX35 (anti-macrophages and CD4+ lymphocytes)-positive cells. Macrophage-like cells predominated in the central portion of the pulp, while cells of dendritic appearance usually existed in the periphery of the pulp. Double-immunoperoxidase staining revealed that these cells showed some heterogeneity, but the majority could be classified as ED1+/OX6-/ED2+ cells, which may be Ia-histiocytes. Findings also suggested that true dendritic cells may be included in the ED1+/OX6+/ED2- category of cells. A small number of T lymphocytes and plasma cells were also detected. These results suggest that the normal dental pulp contains a variety of immunocompetent cells, with macrophages as the most dominating. Following the exogenous invasion of pathogenic stimuli in the pulp, these cells may participate in the defense reaction by acting as phagocytes or antigen-presenting cells, which are essential for the initiation of immune responses.

Animals↗
PubMed1992

[A case of subclavian paraganglioma in the superior mediastinum extending to the neck].

A 52-year-old female was admitted to our hospital with left anterior chest pain. On physical examination, an elastic hard mass sized in 3.0 x 2.5 cm was palpable at the left suprasternal area. Chest X-ray film showed a large mass shadow in the cervico-thoracic region, and CT films revealed a well-defined mass in the superior mediastinum which was heterogeneously enhanced by contrast medium. Operation was performed under the preoperative diagnosis of thymic tumor extending upwards. At operation, the tumor was located between the trachea and the left subclavian artery in the superior mediastinum displacing these structures and extending to the neck. Resected specimen which was 5.5 x 3.5 x 3.0 cm in size and 42 gm in weight was well encapsulated and highly vascularized. On microscopic findings, the tumor was finally diagnosed as paraganglioma. According to the classification of Glenner and Grimley, it was thought that the tumor originated from subclavian paraganglion in the superior mediastinum. Subclavian paraganglioma had rarely been reported in the literatures. As subclavian paraganglioma, our patient was the first reported case in Japan.

Female↗
PubMed1992

[The immunosuppressive effects of 0.025% cyclosporin eye drops in alpha cyclodextrin on rabbit corneal allografts].

We reported the ocular penetration of cyclosporin (CYA) and the immunosuppressive effect of rabbit corneal allograft using 0.025% CYA eye drops in alpha-cyclodextrin (alpha-CD). Local application using 0.025% CYA in alpha-CD showed the concentration of 4,133 ng/gr in the cornea, but no detectable levels in aqueous humor and serum. All eyes (10/10) in the CYA eye drop group remained clear for 100 days after corneal allografting. CYA eye drops halted and suppressed the corneal allograft's immune reaction when the treatment was begun early in the initial phase of rejection. These results indicate that 0.025% CYA eye drops in alpha-CD penetrate the cornea 5 to 10 times more than CYA eye drops in lipophilic vehicles. Furthermore, they are extremely effective in suppressing the immune reaction of corneal grafts.

Animals↗
PubMed1991

[Treatment of corneal abrasion].

Forty patients with corneal epithelial defects were randomized into two groups. Group 1 (twenty patients) were treated with chloramphenicol ointment and an eye patch for six hours followed by chloramphenicol eyedrops six time a day for six days. Group 2 (twenty patients) were treated with chloramphenicol ointment and double eye patches for twenty-four hours as the only treatment. The patients were examined the next day, and again after a week. Two patients defected in group 1 and two patients from group 1 were excluded from the experiment because they failed to improve after three and four days, respectively. Five patients from group 2 defected. Corneal epithelial wound healing was found to be significantly faster in the group treated with double eye patches and the patients' subjective problems in this group were significantly less. (Significant with a probability less than 1%).

Bandages↗
PubMed1990

Primary structure of human plasma glutathione peroxidase deduced from cDNA sequences.

Human plasma glutathione peroxidase (GSHPx) has been shown to be a selenium-containing enzyme immunologically distinct from cellular GSHPx. Oligonucleotide probes, based on the partial amino acid sequence of plasma GSHPx, were synthesized and used to screen a human placenta cDNA library. Nucleotide sequence analysis of the obtained clones revealed that GSHPx consisted of a 678-base pair open reading frame coding for a 226-amino acid polypeptide with a Mr of 25,389. About 50% of the deduced amino acid sequence was confirmed by partial amino acid sequencing of the peptides in a lysine endopeptidase-digest of the purified enzyme. The amino acid sequence exhibited only 44% homology with that of human cellular GSHPx. Northern blot analysis revealed a single transcript of 2.2 kilobases in the poly(A)+ RNA fractions of human placenta and HepG2 (a human hepatic cell line), but not that of human liver and endothelial cells.

Amino Acid Sequence↗
PubMed1989

Specific labeling of beef heart mitochondrial ADP/ATP carrier with N-(3-iodo-4-azidophenylpropionamido)cysteinyl- 5-(2'-thiopyridyl)cysteine-coenzyme A (ACT-CoA), a newly synthesized 125I-coenzyme A derivative photolabel.

An azido-125I-CoA photolabel was synthesized from N-(3-iodo-[125I]4-azidophenylpropionamido)cysteinyl- 5-(2'thiopyridyl) cysteine ([125I]ACTP) and CoASH, separated by chromatography on a silica gel TLC, and identified by autoradiography. Synthesis of [125I]ACT-CoA from [125I]ACTP and CoA was further confirmed by monitoring the release of one of the products, thiopyridone, at 343 nm and concurrent formation of [125I] ACT-CoA. Beef heart mitochondria were incubated in the presence of the 125I-CoA derivative with or without specific inhibitors and/or substrates of the ADP/ATP carrier, and immediately photolyzed for 5 s. Sodium dodecyl sulfate-gel electrophoresis and autoradiography of the separated proteins revealed exclusive photolabeling of a 30-kDa protein in the absence of inhibitors of the carrier. This specific photolabeling of the 30-kDa protein was prevented in a concentration-dependent manner by either carboxyatractylate or palmitoyl-CoA (0.1-5 microM), two known inhibitors of the ADP/ATP carrier. ADP reduced the extent of photolabeling of the 30-kDa protein, but palmitic acid, free CoASH, and dinitrophenol were ineffective, indicating the specificity of the reaction. CoA photolabels may be useful in probing ligand and/or substrate binding sites and in determining the structure-function relationship of the ADP/ATP carrier.

Acyl Coenzyme A↗
PubMed1989

Sono-enterocolonography by oral water administration.

A new ultrasound technique for intestinal examination, named "sono-enterocolonography by oral water administration," was devised. The diagnostic usefulness and limitations of this procedure were studied in 56 subjects including 42 normal patients, 10 patients with 13 colonic polyps and 4 patients with colon carcinomas. Except for the rectum, almost all the intestines were clearly visualized by ultra-sonography as tubular structures filled with water. In every case, ileocecal valve movement was clearly observed dynamically. Eight of the 9 elevated polypoid lesions of the bowel, ranging in size from 10 mm to 20 mm, were detected by this method without any special pretreatment. Although this method may not be indicated for the screening of minute lesions, it may possibly be useful as a supportive diagnostic modality for intestinal disorders, especially in the ileocecal region.

Administration, Oral↗
PubMed1989

Physiological significance of mucous neck cell-type mucins in the healing of acetic acid-induced gastric ulcers in rats.

The present study was undertaken to elucidate the role of mucous secreting cells in the healing of acetic acid-induced gastric ulcers in rats. The results indicated that mucous neck cells (MNCs) and their secretions seem to play important roles in the prevention of the expansion of ulceration in the early stage. The reasons are that the surface mucous layer coating the ulcerated surface almost exclusively consists of MNC-type mucins and MNCs increase markedly in the mucosae surrounding ulcers. Transitional type cells containing both MNC-type and chief cell-type granules frequently occurred in this region, although chief cells almost completely disappeared.

Acetates↗