Biomedical subjects

K Isono

Publications and source records attributed to K Isono.

At least 217 records · Page 12Linked to original sources

PubMed1993

Transport of mitoribosomal proteins, YmL13 and MRP7, into isolated mitochondria of Saccharomyces cerevisiae.

Two mitochondrial ribosomal proteins, YmL13 and MRP7, of the yeast Saccharomyces cerevisiae and their derivatives were synthesized in vitro and their transport into isolated yeast mitochondria was examined. Both proteins were transported into yeast mitochondria in an energy-dependent manner. MRP7 protein was transported even when its N-terminal presequence was deleted, and the N-terminal presequence alone was not capable of transporting a fused passenger protein, Chinese hamster DHFR. YmL13 protein, on the other hand, was not transported without its N-terminal presequence, and its presequence was capable of transporting Chinese hamster DHFR into mitochondria. Thus, MRP7 appears to possess a transport signal in its mature part, while YmL13 possesses a signal only in its N-terminal presequence.

Amino Acid Sequence↗

PubMed1993

[The effect of free radicals from non-parenchymal cells (NPC) of the liver on the development of liver metastases in rat].

Tumor cells (AH130 hepatoma cell originated from rat) were injected intraportally into Donryu rats to produce liver metastases 21 days later. Phagocyte cells activity was depressed by the administration of Silica, which significantly increased the number of surface liver metastases. Phagocyte cells were stimulated by beta 1-3-glucan, which significantly reduced the number of metastases. And the administration of free radical scavenger (SOD, Catalase) increased the number of metastases. Non parenchymal cells (NPC) of the liver play a main role of self defence line for portally liver metastases. Then free radical from these cells were noticed in this study. NPC were isolated, from pronase perfused rat liver. O2- production by activated NPC was measured by chemiluminescence with CLA. NPC activated by beta 1-3-glucan added sera increased the luminescence of CLA, and SOD depressed the production of chemiluminescence. SOD activity of hepatocytes and tumor cells (AH130) were measured by NBT methods. Hepatocytes had high potential production of SOD, in contrast AH130 had poor production. These results suggest that free radicals from liver NPC was important for protecting liver metastases.

Animals↗

PubMed1993

[Correlations between estrogen receptor and prognostic factors of patients with breast cancer. The Kanto Cooperative Study Group of Adjuvant Chemoendocrine Therapy for Breast Cancer, Japan].

We investigated possible correlations between estrogen receptor (ER) and prognostic factors in 3,789 patients with stage II or stage IIIa breast cancer in Japan. The patients with ER-positive tumors showed a significantly better prognosis in the 5-year survival rate and the 5-year disease-free survival rate compared with the patients with ER-negative-tumor. Positivities increased with increasing patient age, with increasing tumor size, and lowering degree of cell differentiation, and no relation was observed between the positivities and tumor sites, obesity index, and lymph-node metastasis.

Adult↗

PubMed1993

Cloning and structural analysis of a human thymidylate synthase pseudogene splitted by several Alu sequences.

An unidentified genomic DNA fragment of 2.4kb that is weakly hybridizable with thymidylate synthase (TS) cDNA was cloned from a human genomic DNA library. Sequencing of the cloned DNA fragment and comparison of the sequence with that of the known human TS cDNA revealed that the DNA fragment contained a human TS processed pseudogene with unusual features. Based on the rate of nucleotide substitutions for neutral mutations in the 3'-untranslated regions between the gene and the pseudogene, it was estimated that the human TS pseudogene was formed about 16 million years ago.

Biological Evolution↗

PubMed1993

[Anatomical study on the right bronchial artery for operation of esophageal cancer through right thoracotomy with special reference to the intercostobronchial arteries].

In view of the operative field of esophageal cancer, anatomical findings of the right bronchial arteries were studied in specimens of 71 cadavers. Intercostobronchial arteries were absent only in 3 cadavers (4.2%; group A). As 22.6% of the cadavers had only one intercostobronchial artery supplied as the right bronchial artery (group B), it was considered to be important to preserve this artery. Cadavers both with the intercostobronchial artery and with the other right bronchial-arteries were observed in 70.4% (group C). Right bronchial arteries deriving from the aorta to course similarly to intercostobronchial arteries were present in small number (group D). Further, right bronchial arteries were classified into three types according to the deriving arteries as follows: (I) intercostobronchial arteries, (II) bronchial arteries deriving from the aorta, (III) other right bronchial arteries deriving from right subclavian artery, right inferior thyroid artery or right interthoracic artery. Considering difficulty of the approach from the operative field with right thoracotomy and the anatomical relationship with neighboring organs, it was thought that preserving the type (I) arteries is easy, the type (III) has a possibility to be preserved, and (II) is hard to be preserved. We concluded that preserving intercostobronchial arteries is important in esophageal cancer surgery approached through right thoracotomy because of small number of cadavers without these arteries and ease of preservation.

Adult↗

PubMed1993

[Analysis of antigen non-specific suppressor T cells factor (TsF) which suppresses the generation of cytotoxic T lymphocytes].

Anti-mouse melanoma suppressor T cells clone (F12) secreted a functional factor (TsF) which suppresses the generation of cytotoxic T lymphocytes (CTL). Ts clone F12 secreted TsF into culture supernatant by stimulating for more than 12 hours with anti-CD3 monoclonal Ab. In syngeneic CTL induction system, TsF suppresses the generation of both anti-melanoma and anti-lymphoma CTL. Moreover, TsF suppresses allogeneic CTL not only from C57BL/6 mice but also from C3H mice. Analysis of the biochemical and physiochemical character of TsF shows that TsF is stable for variance of pH and freeze and thawing, but unstable for heat in region of 100 degrees C. and in acetonitorile. It is also suggested that the molecular weight of TsF is in the vicinity of 12,000 daltons on the analysis in high performance liquid chromatography. F12 clone secretes other suppressive cytokine, TGF-beta and INF-gamma. However, TsF seems different from these suppressive cytokine, because anti-TGF-beta serum which blocks the suppressive function of TGF-beta 1 for CTL generation does not block TsF function. Moreover, recombinant INF-gamma does not suppress the generation of CTL.

Animals↗

PubMed1993

[Anatomic study of the bronchial arteries for operation of esophageal cancer].

In view of the operative field of esophageal cancer, anatomic findings of the bronchial arteries were studied in specimens of 38 cadavers. The number of right and left bronchial arteries were 68 and 61, respectively. The most common branching type was two right and two left arteries, occurring in 36.8% (14/38). Next common type was two right and one left arteries (34.2%). Each specimen had one right intercostobronchial artery and it was considered easy to preserve blood supply to right bronchial artery when cleansing of mediastinal lymphatic chain is performed. But the other 30 right bronchial arteries originating from the aorta coursed, to the area of inferior tracheobronchial lymph nodes, and thus there will be possibility of injury. All of the left bronchial arteries derived from the aorta. The course of 5 left bronchial arteries ran to the area of inferior tracheobronchial lymph nodes, and the one of 41 arteries passed to the area of left tracheobronchial lymph nodes. Therefore, there will be strong possibility of injury to these left bronchial arteries. But the other 19 left bronchial arteries didn't course to any area of lymph nodes, and the arteries can possibly be preserved.

Adult↗

PubMed1993

[Multimodality treatment of thoracic esophageal carcinoma].

Current multimodality treatment of thoracic esophageal carcinoma in our institution was described. The rate of superficial carcinomas is increasing in recent years, and they are treated by endoscopic mucosal resection (EMR), transhiatal esophagectomy (THE) or with the thoracotomy approach. Treatment is based on precise diagnosis of the depth of cancer invasion and nodal involvement using endoscopy with endoscopic ultrasound (EUS). Three-field lymphadenectomy for thoracic esophageal carcinoma, including superficial one, was started in 1983 as a standard operation, and its indications have been gradually decreasing for the past 10 years. As a result of accurate, individualized treatment, life table analysis revealed no significant difference between 2- and 3-field lymphadenectomy. Multimodality treatment of advanced cases is mainly composed of 3-field lymphadenectomy. Adjuvant chemotherapy of systemic therapy is regarded as more important than concurrent irradiation of local therapy. Recently powerful chemotherapy is becoming more frequent pre- or postoperatively. Our routine regimen is CDDP and infusional 5-FU with leucovorin as a biochemical modulator.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1993

[Effect of bradykinin on airway epithelial ion transport and its modulation by endogenous peptidases].

To elucidate the effect of bradykinin (BK) on airway epithelial ion transport function and its modulation by endogenous peptidases, we studied the electrical properties of canine cultured tracheal epithelium under short-circuited conditions in vitro. Addition of BK to the mucosal side of Ussing chamber increased short-circuit current (SCC) in a dose-dependent manner, the maximal rise from the baseline value (delta SCC max) and the concentration required to produce a half-maximal effect being 7.1 +/- 0.7 microA/cm2 (p < 0.001) and 3.9 +/- 1.0 x 10(-7) M, respectively. This effect was greatly attenuated by the B2-receptor antagonist (D-Arg, Hyp3, Thi5,8, d-Phe7)-BK but not by the B1-receptor antagonist (Des-Arg9, Leu8)-BK. Blockade of angiotensin converting enzyme and aminopeptidase P by captopril and mercaptoethanol did not alter the BK-induced increase in SCC. On the other hand, phosphoramidon and MERGAPTA, inhibitors of neutral endopeptidase and carboxypeptidase N, respectively, strengthened the effect of BK. These results suggest that BK stimulates airway epithelial electrical properties through the activation of B2-receptor subtype, and that endogenous peptidases including neutral nedopeptidase and carboxypeptidase N may play a modulatory role in this action of BK.

Animals↗

PubMed1993

[Tissue oxygen metabolism and cellular injury in patients with septic multiple organ failure (SMOF)].

The present study was undertaken to study the pathophysiology of SMOF from the aspect of tissue hypoxia. Seventeen postoperative SMOF patients (9 survivors, 8 non-survivors) and 14 control ICU patients were evaluated their oxygen delivery (DO2I) and oxygen consumption (VO2I) in relation to cellular injury score (CIS) derived from 3 different intracellular metabolic indices, arterial ketone body ratio (AKBR), osmolality gap (OG) and blood lactate. In the early stage, SMOF patients showed hyperdynamic state and increased VO2I, reflecting increased oxygen demand in tissue. However, CIS of SMOF was significantly higher than that of control in spite of increased VO2I, indicating relative tissue hypoxia might exist in vital organs resulting in cellular injury. Further deterioration of CIS was accompanied with decreased VO2I. These data suggest that impaired tissue oxygen metabolism correlates with cellular injury and might be one of mechanisms of organ failure in SMOF patients.

Cell Hypoxia↗

PubMed1993