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Biomedical subjects

I Hayashi

Publications and source records attributed to I Hayashi.

At least 91 records · Page 5Linked to original sources
PubMed1998

Crucial suppressive role of renal kallikrein-kinin system in development of salt-sensitive hypertension.

Tissue kallikrein and low molecular weight kininogen are localized in the particular cells of the connecting tubules, indicating that kinin is immediately generated in the lumina of the lower nephrons. The role of the renal kallikreinkinin system was studied using mutant kininogen-deficient Brown NorwayKatholiek (BN-Ka) rats, and compared with that in normal BN-Kitasato rats of the same strain. Mutant BN-Ka rats showed no visible changes, but they were very sensitive to excess sodium ingestion and to the tendency of sodium to accumulate in the body by aldosterone released by angiotensin II, so that sodium was accumulated in erythrocytes and cerebrospinal fluid in BN-Ka rats and hypertension was induced. After four days infusion of 0.3 M NaCl solution to conscious and unrestrained mutant BN-Ka rats, the sensitivity of the vascular smooth muscle to norepinephrine and angiotensin II increased 30-fold and 10-fold, respectively. Bradykinin was degraded by neutral endopeptidase (NEP) and carboxypeptidase Y-like exopeptidase (CPY) in rat and human urine. Daily oral administration of a selective inhibitor of CPY, ebelactone B, or that of NEP, BP1O2, prevented development of deoxycorticosterone acetate-salt hypertension in Sprague-Dawley rats. These results indicate that: 1) the renal kallikrein-kinin system allows excretion of excess sodium in the body, 2) decreased sodium excretion due to reduced excretion of urinary kallikrein in patients with essential hypertension or in genetically hypertensive rats may cause hypertension, and 3) urine kininase inhibitors such as ebelactone B may emerge as a new antihypertensive drug.

Animals↗
PubMed1997

Expression of bovine mitochondrial tRNASer GCU derivatives in Escherichia coli.

By replacing a stretch of five A-U base pairs in the acceptor stem with G-C pairs, mitochondrial tRNA-SerGCU lacking a D arm could be expressed in Escherichia coli cells in considerable amounts. The expressed tRNA with no modified nucleoside was serylated in vitro with the mitochondrial enzyme. The tRNASerGCU derivatives carrying identity elements for alanine tRNA and the related anticodons were expressed. However, this expression event did not affect cell growth, probably because the expression started from the late log phase, which suggests that these mitochondrial tRNA derivatives are not involved in E.coli gene expression systems. Although there are some restrictions in the secondary structure of tRNAs that can be expressed by this method, it could prove useful for preparing large amounts of heterologous tRNAs in vivo.

Alanine↗
PubMed1997

Assignment of imino proton signals of G-C base pairs and magnesium ion binding: an NMR study of bovine mitochondrial tRNA(SerGCU) lacking the entire D arm.

The mammalian mitochondrial tRNA(SerGCU) (mt tRNA[SerGCU]) has a unique structure in that it lacks the whole D arm. To elucidate its higher-order structure, we synthesized unmodified bovine mt tRNA(SerGCU) using T7 RNA polymerase and measured its 1H-NMR spectrum in the imino proton region. Although the imino proton signals heavily overlapped, we succeeded in assigning all the seven imino proton signals of the G-C base pairs by a combination of base replacement and 15N-labeling of the G residues of a whole tRNA molecule or of the 3'-half fragment. The results indicate that the tRNA possesses the secondary structure that has been supposed on the basis of biochemical studies. Analysis of the effect of the magnesium concentration on the G-C pairs suggests that the acceptor and T stems do not form a co-axial helix, and that the core region of the tRNA does not interact with magnesium ions. These features are significantly different from those of canonical tRNAs. Despite this, it is very likely that the tRNA as a whole takes a nearly L-shape tertiary structure.

Animals↗
PubMed1997

First case of surgical treatment of Farber's disease.

Farber's disease (Farber's lipogranulomatosis), which is inherited as an autosomal recessive trait, was first reported by Farber in 1952. We report a case of Farber's disease in a 12-year-old female. Her younger brother was affected with Farber's disease and died of it at 2 years of age. When she first presented, our patient's main clinical features were a shrill voice; subcutaneous nodules; contracture of the joints throughout the body; and granulomas of the oral cavity, the pharynx, and the upper and lower eyelids. Serial radiographs disclosed deformation of the joints throughout the body. Due to the granulomas in her oral cavity, she could take little food orally and therefore was malnourished. We performed a granulectomy under general anesthesia, and her difficulty with feeding and upper airway obstruction improved. There is no specific treatment for Farber's disease, and most patients reported have died by 2 years of age. This is the first reported patient with Farber's disease who has been surgically treated.

Ceramides↗
PubMed1997

Arterialized occipitoparietal osteocutaneous flap.

We treated a case of postoperative osteomyelitis and epidural abscess in the left temporal and parietal region. The scalp and skull defect following debridement was reconstructed immediately with an arterialized occipitoparietal osteocutaneous flap that was supplied proximally by the occipital artery and distally by the superficial temporal artery. This method is one of the alternative methods for small to moderately sized skull and scalp defects in the temporal, parietal, and occipital areas without available superficial temporal artery.

Female↗
PubMed1997

Renal hemodynamic changes induced by captopril and angiotensin-converting enzyme gene polymorphism.

We studied the relationship between renal hemodynamic changes induced by a single acute administration of captopril (50 mg p.o.) and angiotensin-converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism in 27 healthy human volunteers, 7 with DD genotype, 10 with ID, and 10 with II genotype. The increase in effective renal plasma flow (p < 0.02) and the fall in renal vascular resistance (p < 0.01) in response to captopril were significantly less in subjects with the DD genotype than in subjects with the other genotypes. These data suggest that intrarenal ACE inhibition by captopril differs according to ACE gene ID polymorphism in healthy humans.

Adult↗
PubMed1997

Renal angiotensin-converting enzyme localization in diabetic rats and the effect of low protein diet.

Recent evidence suggests a role of angiotensin-converting enzyme (ACE) in diabetic nephropathy. The effect of diabetes and low protein diet on renal immunohistochemical ACE localization was studied in streptozotocin-induced DM rats. Immunohistochemical ACE localization was reduced in DM rats, and a low protein diet partially resolved this abnormality while inhibiting the progression of diabetic nephropathy.

Albuminuria↗
PubMed1997

Phase II study of irinotecan and etoposide in patients with metastatic non-small-cell lung cancer.

PURPOSE: To determine the effects of irinotecan (CPT-11) given in combination with etoposide (VP-16) in metastatic non-small-cell lung cancer (NSCLC), to evaluate response and survival rates, and to determine the qualitative and quantitative toxicities of the combination chemotherapy. PATIENTS AND METHODS: Sixty-one metastatic NSCLC patients received concurrent administration of CPT-11 and VP-16 for 3 days with recombinant human granulocyte colony-stimulating factor (rhG-CSF) support. RESULTS: Fifty-nine patients were assessable for response and all 61 patients were assessable for toxicity and survival. Fifty-six patients were treated with two or more courses of chemotherapy. Thirteen patients achieved a partial response (PR), 36 showed no change (NC), and 10 showed progressive disease (PD). The overall response rate was 21.3% (95% confidence interval, 12.9% to 33.1%). The median duration of PRs was 141 days (range, 62 to 299). Of the hematologic toxicities, 14 (23%) and 24 (39%) patients experienced grade 3 or 4 leukopenia and neutropenia, respectively. The toxicities were feasible. Treatment-related death occurred in one patient who suffered hypovolemic shock induced by hematemesis. The median survival time was 10.0 months and the 1-year survival rate was 36.1%. CONCLUSION: Combination chemotherapy with concurrent administration of CPT-11 and VP-16 with rhG-CSF support was only modestly effective against metastatic NSCLC, with feasible toxicities of moderate diarrhea and pulmonary toxicity. The results were equivalent to those expected with either cisplatin-based chemotherapy or with CPT-11 alone.

Adenocarcinoma↗
PubMed1997

Significant roles of inducible cyclooxygenase (COX)-2 in angiogenesis in rat sponge implants.

Angiogenesis in rat sponge implants, as determined from the concentration of hemoglobin in the sponge granuloma tissues, was gradually increased over a 14-day experimental period. The inducible cyclooxygenase COX-2 was detected in the sponge granuloma tissues at day 4 by Western blot analysis using specific mouse COX-2 antibody. Angiogenesis in the sponge implants was enhanced by daily topical injections of human recombinant basic fibroblast growth factor (bFGF) or human recombinant epidermal growth factor (EGF) (100 or 1000 ng/sponge/day) for 4 days. These treatments clearly enhanced the expression of COX-2 in the sponge granuloma tissues. In immunohistochemical studies, COX-2-positive staining was mainly observed in the endothelial cells of the neovasculature and in the fibroblasts of the granuloma capsule. Administration of the selective COX-2 inhibitor NS-398 (p.o., 3 mg/kg, 3 times a day) for 14 days significantly inhibited the angiogenesis. The angiogenesis enhanced with bFGF or EGF (day 4) was inhibited by administration of indomethacin or NS-398, both in the above regimen, and fell to the level obtained without growth factor treatment. These results suggest that COX-2 induced in the sponge granuloma tissues may participate in neovascularization through prostaglandin formation.

Animals↗
PubMed1997

[Phase II study of combination chemotherapy with cisplatin, carboplatin and etoposide (CPVP) in unresectable non-small cell lung cancer: analysis of survival time and prognostic factors].

Phase II study of combination chemotherapy with cisplatin, carboplatin and etoposide (CPVP) was conducted in 46 patients with unresectable non-small cell lung cancer. In the previous paper, we showed that CPVP produced a satisfactory response rate without major toxicities. In the present paper, survival time and prognostic factors were analyzed. The median survival time (MST), 1- and 2-year survival of 46 patients (III A4, III B15, IV 27) were 14.1 months, 57.0% and 18.2%, respectively. In prognostic analysis, responders survived significantly longer than non-responders (MST: 15.8 vs 11.0 months, p < 0.05). Large cell carcinoma and stage IV have proven to be indicators of poor prognosis. Females and patients less than 60 years old tended to do better. With regard to the relationship between the time from initiation of treatment to response and survival time, late responders (response after 3 or 4 courses) survived significantly (p < 0.05) longer than early responders (response after 1 or 2 courses). The CPVP regimen is not only practical, but also very effective. It deserves further study to reveal its advantages compared to the other platinum compound containing regimens.

Adult↗
PubMed1997

Limited sampling model for the area under the concentration versus time curve of irinotecan and its application to a multicentric phase II trial.

We previously established a limited sampling model (LSM) for the area under the concentration versus time curve (AUC) of irinotecan (CPT-11). Using this LSM, we performed a pharmacokinetic-pharmacodynamic analysis of CPT-11 in a multicentric Phase II study for non-small cell lung cancer. Ten institutes participated in this study, 36 patients were registered, and 30 patients were evaluable for the pharmacokinetic-pharmacodynamic analysis. CPT-11 and etoposide were administered daily for three consecutive days, both at a dose of 60 mg/m2. Blood samples were obtained 4 and 8 h after infusion on days 1 and 3. When using the LSM, there is a significant possible source of error in the timing of these selected points. In this study, however, the sample timing error was small. Mean timing errors were 1.0-4.0 min at each point. The estimated CPT-11 AUCs were: Day 1 Day 2 Day 1 + 3 Mean +/- SD (mg.h/liter) 3.76+/-0.68 4.10+/-0.86 7.86+/-1.43 Range 2.01-5.03 2. 29-5.72 4.30-10.68 Max/min 2.50 2.45 2.48 High interpatient variability was observed in the AUC. The CPT-11 AUC correlated positively with the grade of emesis (P = 0.003) and the percent decreases in WBC count (P = 0.001) and absolute neutrophil count (P =0.0006), but it did not correlate with the grade of diarrhea or response. We concluded that the LSM was useful in estimating individual pharmacokinetic parameters in multicentric trials.

Aged↗
PubMed1996

Evaluation of gamma camera-based measurement of individual kidney function using iodine-123 orthoiodohippurate.

Gamma camera-based clearance techniques which use the renal uptake ratio (RUR) of the radiotracer are available to estimate the effective renal plasma flow (ERPF) and glomerular filtration rate. To evaluate the accuracy of these techniques, we measured RUR by an optimized procedure and compared it with standard ERPF. Iodine-123 orthoiodohippurate (OIH) scintigraphy and simultaneous para-aminohippurate clearance study for measuring standard ERPF were performed in three hospitals in 24 patients with normal or mildly impaired renal function. 123I-OIH was injected intravenously and 10-s consecutive imaging of the kidneys was started when the abdominal aorta was seen. The attenuation coefficient for 123I was measured in each hospital using the same water-equivalent absorption materials and used for the attenuation correction. After subtracting background radioactivity, RURs were defined as the count ratios of fractional renal uptakes based on the integral from 1 to 2, 2 to 3, 1.5 to 2.5 and 1 to 3 min after the injection of 123I-OIH in relation to injected doses using the following three procedures in respect of attenuation correction: (1) RUR without attenuation correction, (2) RUR with fractional renal uptake corrected by the measured attenuation coefficient, (3) RUR with the total injected dose corrected by the absorption material. To decide upon the appropriate correction method and time interval, RURs were compared with standard ERPF. Among the three correction methods, procedure 2 showed the highest correlation between RUR and standard ERPF, but the correlation coefficient was low (r=0.75). No significant difference was observed among the RURs of each time interval. Individual kidney function measured from early renal uptake may be inaccurate even when appropriate correction is made for attenuation, background activity or time lag between injection and data acquisition. Gamma camera-based measurement of renal function using 123I-OIH is limited with regard to accuracy and reproducibility, though it is convenient and non-invasive.

Adult↗
PubMed1996

Alpha-fetoprotein-producing adenocarcinoma of the lung.

We herein present a case of metachronous primary lung cancers, the first of which was adenosquamous cell carcinoma and the second of which was poorly differentiated adenocarcinoma. At the time the second lung cancer was detected 5 years after being operated on for the first cancer, a high level of serum alpha-fetoprotein (AFP) was noticed, but no elevation of other tumor markers was observed. In addition, no liver metastases, chronic liver diseases or other systemic abnormalities were seen either. The serum AFP level was 696 ng/ml, and the profile of lectin affinity showed a tumor-derived pattern. Two weeks after the operation, the serum AFP level decreased to a normal level. An immunohistochemical analysis confirmed that the exact origin of AFP was the tumor tissue. A specimen taken from the first lung cancer was not stained by the same procedures, which thus indicated this case to be a double primary lung cancer.

Adenocarcinoma↗
PubMed1996

Phase I/II study of combination chemotherapy with cisplatin, carboplatin and etoposide in small cell lung cancer.

A Phase I/II study of combination chemotherapy with cisplatin (CDDP), carboplatin (CBDCA) and etoposide (VP-16) (CPVP) was conducted in patients with small cell lung cancer. The dose level of etoposide was fixed at 100 mg/m2, while the doses of CDDP and CBDCA administered at each of the four steps were 50/200, 60/200, 60/250 and 70/250 mg/m2, respectively. Nine patients were allocated to each step dose group. Adverse effects were evaluated during the first two courses to establish the maximum tolerated dose (MTD). As a result, the step 3 doses turned out to be the MTD. The dose-limiting factor was hematotoxicity. Gastrointestinal toxicity was also present, but was tolerated. The overall response rate in patients with measurable or evaluable lesions was 91%. In 22 chemotherapy-naive patients, the median survival time was 16.6 months. These results suggest that the recommended dose is step 2, and that the CPVP regimen might be both more tolerable and more effective than the standard PVP regimen. Based on the above findings, CPVP therapy warrants further study in Phase II and III trials.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1996

Alterations of p16/CDKN2, p53 and ras genes in oral squamous cell carcinomas and premalignant lesions.

Exons 1-3 of the p16/CDKN2 gene, exons 4-9 of the p53 gene and exons 1 and 2 of H-, K- and N-ras genes were screened for mutations by a combination of immunohistochemistry and single-strand conformational polymorphism (SSCP) analyses of polymerase chain reaction products from human surgical samples of both frank oral squamous cell carcinomas and premalignant lesions. The samples included 20 squamous cell carcinomas, 10 epithelial dysplasias and 10 epithelial hyperplasias. No identifiable gene mutations were detected in any of the dysplasias or hyperplasias, while 2 (10%) deletions and 2 (10%) mutations of p16/CDKN2, along with 5 (25%) p53 mutations were found in the advanced carcinomas, yielding characteristic p16/ CDKN2 and p53 changes. A mutation in the K-ras gene was found in single carcinoma and dysplastic samples. From the data, it can be argued that p16/CDKN2 and p53 mutations are relatively late occurrences in human oral tumorigenesis and that genetic alterations of the ras genes may not play a significant role in squamous neoplasia.

Carcinoma, Squamous Cell↗
PubMed1996

[The clinical value of BMIPP on the evaluation of myocardial ischemia and metabolism before and after CABG].

To evaluate the clinical usefulness of BMIPP (15-(p-[125I]-iodophenyl)-3-R, S-methylpentadecanoic acid), BMIPP and T1 imaging were underwent before and after surgery in 25 CABG patients. Preoperatively the demonstrated lesion on BMIPP scintigram is almost the same as that on rest-T1 scintigram. A month after CABG, the recovery on T1 scintigram was remarkable, however improvement on BMIPP was limited. These results suggest that on the evaluation of myocardial ischemia, the clinical value of BMIPP is almost the same as that of rest-T1 before CABG. The postoperative discrepancy between T1 and BMIPP scintigram suggests that the restoration of myocardial circulation does not directly improve myocardial metabolism.

Coronary Angiography↗