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Biomedical subjects

H Katoh

Publications and source records attributed to H Katoh.

At least 289 records · Page 16Linked to original sources
PubMed1994

Characterization of new inbred strains of Dahl-Iwai salt-sensitive and salt-resistant rats.

Dahl-Iwai salt-sensitive (S) and salt-resistant (R) rat strains were newly established as inbred strains. To characterize the strains, the Dahl-Iwai S and R rats were fed low-salt (0.3% NaCl) and high-salt (8.0% NaCl) diets from 5 weeks after birth, and systolic blood pressure and pathologic findings were examined at intervals. The distributions of alleles at 19 biochemical and immunologic loci also were examined in the aforementioned strains, together with those for the inbred SS/Sea and SR/Sea strains, which were derived from inbred SS/Jr and SR/Jr strains, respectively. The Dahl-Iwai S rats were hypertensive after 3 weeks of consuming the 8.0% NaCl diet and died from 6 to 10 weeks after the diet was initiated. Renal lesions developed after 4 weeks' consumption of the high-salt diet. The Dahl-Iwai S rats were not hypertensive until at least the age of 21 weeks while they consumed the 0.3% NaCl diet, whereas it was reported that the SS/Jr rats became hypertensive at about 20 weeks of age when they consumed the low-salt diet. The Dahl-Iwai R rats were normotensive whether fed the 0.3 or 8.0% NaCl diet. Hydronephrosis was not observed in the Dahl-Iwai R rats, though it develops in SR/Jr rats with high frequency. Different distributions were detected for kidney alkaline phosphatase-1 (Akp-1) and amylase-1 (Amy-1) alleles between the Dahl-Iwai S and SS/Sea strains, and for esterase-14 (Es-14) and seminal vesicle protein-1 (Svp-1) alleles between the Dahl-Iwai R and SR/Sea strains. The phenotypic differences between the substrains of inbred Dahl rats could be ascribed to different genetic backgrounds.

Aging↗
PubMed1994

[Influence of extracorporeal shock wave lithotripsy (ESWL) on renal function assessed by 99mTc-DMSA scintigraphy: comparative analysis between ESWL and percutaneous nephroureterolithotripsy (PNL)].

99mTc-DMSA renal scintigraphy was utilized to investigate the influence of ESWL on renal function in comparison with that of PNL. In the beginning, the reproducibility of renal uptake rate by the scintigraphy was examined in eleven healthy volunteers under both non-diuretic and diuretic states. The renal uptake rate was shown to be sufficiently reproducible in the same person in the two different trials. However, the differences and the standard deviations were shown to be a few percentages, which were not statistically significant. Changes in the repeated renal uptake rate seem to indicate not only changes of renal function with the treatment but also some technical errors. Herein, to investigate changes in renal function of the therapeutic side, the uptake ratio rate (rate of uptake rate in the therapeutic side/uptake rate in the contral lateral side) was utilized instead of uptake rate. Renal scintigraphy was carried out in 48 patients with unilateral renal stones before and after ESWL or PNL monotherapy or the combined ESWL and PNL therapies. Within one week of treatment, the uptake ratio rate significantly decreased in patients with PNL or the combined ESWL and PNL, although DMSA uptake rate in the therapeutic side did not significantly changes. Neither renal uptake rate nor uptake ratio rate significantly changed after ESWL treatment. There was no significant difference in changes of uptake ratio rate between Siemens Lithostars Plus and the improved Dornier HM-3 lithotriptors. This study indicated that ESWL monotherapy did not affect the uptake ratio rate, although PNL monotherapy and the combined ESWL and PNL therapies may affect the uptake ratio rate to some extent.

Adult↗
PubMed1994

[Surgical treatment of pancreatobiliary carcinoma in the elderly].

Between January, 1980 and December, 1992, 256 patients underwent resection of pancreatobiliary carcinoma. Sixty eight of these patients were more than 70 years old and are the subject of this review. The morbidity rate for pancreatic cancer patients undergoing pancreaticoduodenectomy was 50%. The five years survival rate was 15%. The morbidity rate for biliary cancer patients undergoing major resection was 40%. The five year survival rate was 40%. The data presented demonstrate that extended operation for pancreatic cancer should not be performed in the elderly patients but major resection for biliary cancer can be performed, even in elderly patients, with a low but somewhat increased mortality risk. Methods of estimating risk factor for elderly patients are required.

Aged↗
PubMed1994

[Thoracoscopic treatment of mediastinal thymic cyst].

A mediastinal thymic cyst was excised under thoracoscope in a 66 year-old man. Mass lesion was noted in the left anterior mediastinum on chest X-p during a screening examination. Based on the findings of the chest CT and MRI, the mass was diagnosed as a cyst containing low fat and low protein fluid without solid tissue. This lesion was diagnosed as a mediastinal thymic cyst. Under general anesthesia, the thoracoscopy was inserted to the left thoracic cavity. Then, the cyst was resected sharply and bluntly with pair of scissors, while electric coagulation was performed as needed. In cases of mediastinal thymic cyst, it is possible to completely resect the cyst by thoracoscopic treatment, causing minimal surgical invasiveness. Considering that a few thymic cysts are combined with malignant tumor, complete resection of the lesion is required in the treatment of thymic cyst.

Aged↗
PubMed1994

[Recent advances in immunological diagnosis for tuberculosis].

Recent advances in immunological diagnosis for tuberculosis including tuberculin Mantoux test and serodiagnosis were reviewed. New tuberculins (T1327, T1456) were reported to be more specific than the conventional one (RT23). Tuberculins from atypical mycobacteria (PPD-B, PPD-Y, PPD-F) were reported as a useful tool for the diagnosis of atypical mycobacteriosis. Optical density index method is a most appropriate method for a clinical use among several methods for the expression of antigen titer in serodiagnosis using ELISA. The duration of disease is important for understanding the results. IgM antibody rises in the early stage of the disease and comes down in 10 weeks after onset, while IgG antibody rises lately. Anti-cord factor antibody is a highly specific antibody for tuberculosis and may be a potent candidate for a clinical diagnostic tool. Anti-PPD-B antibody was elevated in atypical mycobacteriosis and pulmonary tuberculosis also. The ratio of anti-PPD-B antibody to anti-PPDs antibody was elevated in atypical mycobacteriosis while it was lowered in pulmonary tuberculosis. It may be helpful for suggesting the causative organism when the sputum smear is positive. The opposite results have been reported on the serodiagnosis in HIV infection. The usefulness of serodiagnosis for tuberculosis in HIV infected patients remained controversial.

Antibodies, Bacterial↗
PubMed1993

Mast cell number in the skin of heterozygotes reflects the molecular nature of c-kit mutation.

The W locus of mice encodes the c-kit receptor tyrosine kinase. Heterozygous WJic/+ and Wn/+ mice and homozygous Wf/Wf mice were similar in appearance; all of them have large depigmented areas lacking any well-defined pattern. The WJic, Wn, and Wf mutant alleles were characterized and their molecular nature was correlated with the mast cell differentiation in the skin and the biologic features of cultured mast cell (CMC). All WJic, Wn, and Wf were point mutations at the tyrosine kinase domain, and c-kit mRNA was normally transcribed from all of them. The mature 145-Kd form of the c-kit protein was produced from the WJic and Wf alleles, but not from the Wn allele. c-kit proteins produced by the WJic or Wf allele were expressed on the surface of CMCs, but those of the Wn allele were not. When double heterozygous mice were produced between W and WJic and between W and Wn, both W/WJic and W/Wn mice lacked skin mast cells. W/WJic CMCs and W/Wn CMCs did not survive in the coculture with fibroblasts. W/WJic CMCs normally attached to fibroblasts, but W/Wn CMCs did not. The defect of W/Wn CMCs in the attachment was attributed to the deficient extracellular expression of the c-kit protein. The number of skin mast cells was compared among WJic/+, Wn/+, Wf/+, and Wf/Wf mice. Mast cells decreased in WJic/+ and Wf/Wf mice, but not in Wn/+ and Wf/+ mice. Although the Wn was a point mutation at the kinase domain, the biologic effect of the Wn was comparable with that of the W mutant allele, which produces truncated c-kit protein without the transmembrane domain. The weak phenotype of Wn/+ mice may be explained by the deficient extracellular expression of c-kit proteins produced by the Wn allele. When WJic/WJic, Wn/Wn, and Wf/Wf CMCs were stimulated by the recombinant c-kit ligand, autophosphorylation activity was observed only in Wf/Wf CMCs. This result was consistent with the weak biologic effect of the Wf mutant allele.

Adenosine Triphosphate↗
PubMed1993

Tumor necrosis factor-alpha induces expression of monocyte chemoattractant JE via fos and jun genes in clonal osteoblastic MC3T3-E1 cells.

The mechanism by which circulating monocytes are attracted to sites of bone remodeling is unknown. We now report that tumor necrosis factor-alpha (TNF-alpha), a potent osteotrophic cytokine, was stimulatory for expression of the monocyte chemoattractant JE gene in osteoblastic MC3T3-E1 cells. TNF-alpha stimulated this JE gene expression transcriptionally. The presence of JE gene product in conditioned medium of the cytokine-treated cells was evidenced by an immunoprecipitation assay with antiserum specific for JE/MCP-1. The stimulated JE gene expression was markedly inhibited by H-7, a potent inhibitor of protein kinase C. Phorbol 12-myristate 13-acetate induced the JE gene expression, and the cytokine-induced JE gene expression was down-regulated by the phorbol ester pretreatment. TNF-alpha induced expression of both early protooncogenes, c-fos and c-jun, in the cells. Antisense oligonucleotides to these oncogenes significantly inhibited the cytokine-induced monocyte chemotactic activity. Furthermore, curcumin, a specific inhibitor of c-jun/AP-1, markedly inhibited JE gene expression and monocyte chemotactic activity induced by the cytokine. These results suggest that TNF-alpha may contribute to the regulation of remodeling and inflammation of bone tissues through the JE gene product.

3T3 Cells↗
PubMed1993

Congenital arteriovenous malformation of the pancreas with jaundice and a duodenal ulcer: report of a case.

Pancreatic arteriovenous malformation (AVM) is a rare condition which may be associated with AVM of other organs or pathological vascular changes. Portal hypertension, which is very difficult to treat, may complicate such cases and thus, the lesion should be resected as early as possible. We report herein the case of a patient with congenital AVM, presenting with jaundice and a duodenal ulcer, in whom pancreatoduodenectomy provided a means of definitive management. To our knowledge, this is the first case of pancreatic AVM to present with jaundice as the initial symptom.

Adult↗
PubMed1993

Heredity of muscle fibre composition estimated from a selection experiment in rats.

The extent to which muscle fibre composition was determined by the genes transmitted from parents was estimated by using successive selections of rats. A foundation population (G0) was established to carry out the selections; it consisted of 100 albino rats which were randomly chosen from heterogeneous stock. The heterogeneous stock was produced by random-mating of three strains, Wistar-Imamichi, Fischer 344 and Donryu. Successive selection for a high percentage of slow twitch fibres (% ST) was made from G0 to the fourth generation (G4). The mean values of % ST changed from 50.0% in G0 to 55.6% in G4. The mean value in G4 was significantly higher than that in G0. The realized heritability in G0-G4 was calculated from the regression of selection response on the cumulated selection differential. The regression coefficient was 0.17 (SEM 0.04). The realized heritability was significantly different from 0 at the 0.05 level. We concluded that in rats about 17% of the variation of muscle fibre composition was determined by the genes transmitted from parents.

Animals↗
PubMed1993

Effect of E-4031, a new class III antiarrhythmic drug, on reentrant ventricular arrhythmias: comparison with conventional class I drugs.

We evaluated the antiarrhythmic efficacy of E-4031, a new class III drug, and compared it with that of conventional class I and II antiarrhythmic agents in terms of electrophysiological actions on refractoriness and conduction in a 7-day-old canine model of myocardial infarction. Sustained monomorphic VT was reproducibly induced in 26 dogs by a premature stimulation method from the right ventricle. Class I drugs (disopyramide, aprindine, flecainide) prevented VT induction in 5 of 13 dogs, and propranolol and E-4031 prevented it in 6 of 6 and 6 of 7 dogs, respectively. The effective refractory period (ERP) was determined at 47 epicardial sites overlying the infarct in each experiment by a S1S2 method. The standard deviation (SD) of the mean ERP of these sites was used as an index of ERP dispersion. The extent of ERP prolongation produced by class I drugs and E-4031 was significantly more marked than that produced by propranolol. However, the SD was increased by class I drugs and E-4031, but not by propranolol. Class I drugs increased the ERP dispersion mainly by an effect on the transmural infarct zone in which the control ERP was more prolonged than in the normal zone. E-4031 tended to prolong the ERP in both the normal and infarct zones, and had a minimal tendency to increase ERP dispersion. In contrast, propranolol decreased the ERP dispersion between zones. Conduction velocity calculated by epicardial mapping was significantly decreased by flecainide, but not by E-4031. We conclude that the antiarrhythmic effect of E-4031 depends largely on its ability to prolong refractoriness without suppressing conduction.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Increased plasma endothelin-1 concentrations in E. coli septic peritonitis rats with diabetes mellitus.

To study the diabetic mellitus (DM) patient's reaction to sepsis, we investigated the survival rate, the bacteremia, plasma endotoxin and plasma endothelin-1 levels in E. coli septic peritonitis rats with or without streptozotocin-induced DM. No significant difference could be detected between the DM and nondiabetic rats in the survival rate, the bacteremia level or the plasma endotoxin level. The DM rat manifested a significant increase compared to the nondiabetic rat in the plasma endothelin-1 level four hours after the outbreak of peritonitis. Endothelin-1 may thus play some role in the E. coli septic peritonitis rat with DM.

Animals↗
PubMed1993

Analytical method for sugar chain structures involving lectins and membrane ultrafiltration.

A simple and rapid analytical method for the structural identification of sugar chains involving lectins and ultrafiltration was developed. In the procedure, a mixture of fluorogenic sugar chains is mixed with an unmodified lectin. Unbound sugar chains are removed by ultrafiltration. Qualitative differences between sugar chains from the sample and from the filtrate were determined by high performance liquid chromatography. The structures of different sugar chains could be determined from the specificity of the lectins used. Because the lectins used for the procedure were not modified, both the lectins used and sugar chains could be recovered. The method is simple and can be used for structural analysis of sugar chains.

Animals↗
PubMed1993

Experience with FK506 in living-related liver transplantation.

The new immunosuppressive agent FK506 was used with steroids to treat 22 pediatric patients who received living-related partial liver transplantation. Seventeen recipients survived and 5 died between one and 16 months after transplantation. Three of the 5 patients who died had required intensive care preoperatively. Autopsy findings showed no evidence of rejection. There was no episode of rejection that required retransplantation in any of the patients. Liver allograft dysfunction, which was suspected to be a rejection response, was encountered in 2 recipients with ABO-nonidentical but compatible grafts. However, their clinical and biochemical findings were ameliorated upon steroid pulse therapy or upon augmented FK506 administration without additional potent immunosuppressive agents. Steroid treatment has been discontinued in all surviving patients at 1-9 months after transplantation. Infectious complications encountered in 9 patients included 2 bacterial, 5 viral, and 2 fungal infections. One recipient died of fungal pneumonia. Abnormal increase of serum creatinine level was confined to the complicated patients. Hypertension was a temporary adverse reaction in the early postoperative period, and only one patient needed an antihypertensive drug at 2 months after transplantation. Acute pancreatitis with hyperamylasemia was observed in one patient who was treated successfully with reduction of FK506 administration. Tremor was observed in 8 patients, itching in 4, insomnia in 2, and vomiting in one. Hirsutism, gingival hypertrophy, and lymphoma were not observed. FK506 was highly effective in living-related partial liver transplantation not only in terms of immunosuppressive potential but also because it produced fewer adverse effects.

Adolescent↗
PubMed1993

Chromosomal mapping of genetic locus associated with thymus-size enlargement in BUF/Mna rats.

The thymoma-prone rat of the BUF/Mna strain is a useful model for human thymoma. In this strain thymoma development is regulated by a single autosomal susceptible gene, Tsr-1. At pre-thymoma age, BUF/Mna rats have extremely large thymuses, when compared to those of other strains of rats. Genetic studies in crosses between BUF/Mna rats with large thymuses and WKY/NCrj rats with small thymuses suggested the presence of a major autosomal gene, Ten-1, which contributes to thymus enlargement in a backcross population. Linkage studies between Ten-1 and microsatellite markers in backcross rats of (WKY/NCrj x BUF/Mna)F1 x BUF/Mna have led to the localization of Ten-1 in chromosome 1. This result may provide an approach to clone Tsr-1, which could be allelic to Ten-1.

Animals↗
PubMed1993

Correlations of peritoneal interleukin-6, serum beta-2 microglobulin and urinary beta-2 microglobulin after elective abdominal surgery.

Postoperative peritoneal interleukin-6 (P-IL-6), serum beta-2 microglobulin (SBMG) and urinary beta-2 microglobulin (UBMG) concentrations were examined in 33 patients who underwent various types of abdominal surgery. Similar time-dependent changes in SBMG and UBMG were observed in five other patients who underwent abdominal surgery. SBMG decreased the first day after the operation (1POD), then increased and reached the preoperative level by the third day after the operation (3POD). UBMG started to increase 1POD, reached the maximum 3POD, then decreased. The 1POD SBMG concentration was significantly correlated with P-IL-6, and 3POD UBMG was also significantly correlated with P-IL-6. These findings indicate that serum and urinary beta-2 microglobulin concentrations are closely correlated with P-IL-6.

Aged↗
PubMed1993

Polyps of the prostatic urethra. Report of four cases.

We described 4 cases of polyps of the prostatic urethra. Three of them had adenomatous polyp with prostatic epithelium and 1 showed polypoid urethritis. These lesions were worth noting as a cause of hematuria, dysuria or hematospermia. Polyps or papillary lesions of the prostatic urethra appear to be more common than have been suspected. Careful attention should be paid to the prostatic urethra in patients with persistent painless hematuria.

Adult↗
PubMed1993

Ductus arteriosus. Advanced differentiation of smooth muscle cells demonstrated by myosin heavy chain isoform expression in rabbits.

BACKGROUND: The closure of the ductus arteriosus (DA) is one of the most striking cardiovascular events that occur at birth. It has been attributed to oxygenation and intrinsic prostaglandins. However, selective constriction of DA suggests the presence of highly specialized contractile mechanisms in DA. We previously reported that smooth muscle myosin heavy chain isoforms, SM1 and SM2, are molecular markers for smooth muscle differentiation because of their unique expression pattern during vascular development. SM1 and SM2 are generated from a single gene through developmentally regulated alternative RNA splicing; SM1 is expressed in almost all stages of differentiation of the vascular smooth muscles, but SM2 is found only after birth. METHODS AND RESULTS: Immunohistochemistry was performed to study the expression of the different types of myosin heavy chain isoforms in DA of fetal and neonatal rabbits. Electron microscopic examinations were also carried out to demonstrate ultrastructural characteristics of ductus muscles. We found that SM2 is expressed before birth in the medial layer of DA, indicating advanced differentiation of smooth muscle cells in DA. The exact location of immunoreactivity for SM2 was in the smooth muscle cell of the medial layer of DA. Immunoreactivity for SM1, however, was not different for DA and adjacent great arteries. Transmission electron microscopy demonstrated greater amounts of myofilaments in medial smooth muscles of DA than those of aorta. CONCLUSIONS: These results indicate that smooth muscles in DA are more differentiated than those in other arteries, which may be one of the cellular mechanisms responsible for the unique closure of DA at birth.

Actin Cytoskeleton↗