Search PubMed⌕ Search

Biomedical subjects

H Katoh

Publications and source records attributed to H Katoh.

At least 253 records · Page 14Linked to original sources
PubMed1996

[An immunohistochemical study of proliferating cell nuclear antigen (PCNA) and MIB-1 in epithelial hyperplasia and dysplasia of the vocal cords].

We investigated the proliferative activities in epithelial hyperplasia and dysplasia of the human vocal cords as precancerous lesions, using immunohistochemical staining with anti-PCNA and MIB-1 (anti-Ki-67) monoclonal antibody. The series for this study consisted of nine patients with hyperplasia, 12 with mild dysplasia, ten with moderate dysplasia, eight with severe dysplasia, eight with vocal cord polyps, and 14 with invasive squamous cell carcinoma. The following results were obtained: 1) The mean PCNA labeling index was 1.12 +/- 1.05 (MEAN +/- STD%) in polyp, 4.88 +/- 2.02 in hyperplasia, 2.76 +/- 1.76 in mild dysplasia, 3.80 +/- 2.03 in moderate dysplasia, 6.12 +/- 3.01 in severe dysplasia, and 19.07 +/- 10.37 in invasive cancer. 2) The mean MIB-1 positive rates were 5.50 +/- 2.47 (MEAN +/- STD%) in polyp, 13.08 +/- 6.86 in hyperplasia, 16.55 +/- 7.34 in mild dysplasia, 15.94 +/- 6.73 in moderate dysplasia, 21.43 +/- 8.16 in severe dysplasia, and 41.48 +/- 14.05 in invasive cancer. In cases of hyperplasia, dysplasia and invasive cancer, PCNA labeling index values and MIB-1 positive rates increased in proportion to the histological atypical grade increasing. Some lesions which recurred or progressed to cancer were found show high expression of PCNA and MIB-1. In cancer cases, there was no significant correlation between the PCNA labeling index, MIB-1 positive rates and either the degree of tumor cell differentiation or the T-classification. There was a positive correlation between the PCNA labeling index and MIB-1 positive rates among all cases. In this study, those cases showing a high PCNA labeling index and/or MIB-1 positive rates may indicate the possibility of recurrence or progression to malignancy in precancerous lesions of the vocal cords.

Aged↗
PubMed1996

[Evaluation of the bite block wedged between the maxillary and mandibular molars].

The purpose of this study was to compare our original bite block (T-X Block) wedged between the maxillary and mandibular molars, with the standard gum bite block, in 200 patients whose tracheas were intubated. During emergence from isoflurane anesthesia, no trouble occurred in T-X Block group (n = 100). On the other hand, lip damage and ejection of the bite block were found in 11 and 10 cases, respectively, in gum bite block group (n = 100). As another study, an opening between the maxillary and mandibular incisor edges was measured with T-X Block placed in twenty patients under general anesthesia. The inter-incisal distances in one way of using it as a smaller wedge and in the other way as a bigger one were 21.6 +/- 2.4 and 25.2 +/- 2.6 mm, respectively. Those values were significantly larger than thickness of the gum bite block. T-X Block is very useful because its use causes no complications and makes it easier to insert a naso-gastric tube as well as to clean the oral cavity with suction by giving a larger opening of the mouth.

Adolescent↗
PubMed1995

A novel immunoassay of smooth muscle myosin heavy chain in serum.

We have developed a double monoclonal sandwich enzyme immunoassay to measure smooth muscle myosin heavy chain (MHC). Analytical performance of the assay showed reliable detection of smooth muscle MHC in human sera. The mean of the smooth muscle MHC level in normal human sera was 0.9 +/- 0.9 ng/ml. In sera of patients with aortic dissection, the smooth muscle MHC level sharply elevated at the onset and rapidly decreased to normal levels. Immunoassay of smooth muscle MHC in serum is a promising method for biochemical diagnosis of smooth muscle disorders.

Aortic Dissection↗
PubMed1995

Characterization of the signal transduction of prostaglandin E receptor EP1 subtype in cDNA-transfected Chinese hamster ovary cells.

We examined the signal transduction of mouse prostaglandin E receptor EP1 subtype using Chinese hamster ovary cells stably expressing the cloned EP1. Sulprostone, an EP1 agonist, induced a rapid increase in intracellular Ca2+ concentration in the EP1-expressing cells. Most of the increase was abolished by removal of extracellular Ca2+, and was insensitive to U-73122, a phospholipase C inhibitor. Sulprostone stimulated phosphatidylinositol hydrolysis, but this stimulation was abolished by removal of extracellular Ca2+, indicating that EP1-stimulated phosphatidylinositol hydrolysis is the result of extracellular Ca2+ influx. Thus, the signal transduction of EP1 is extracellular Ca2+ entry through a pathway independent of phospholipase C activation. We further examined the regulation of the signal transduction of EP1 having potential phosphorylation sites for either protein kinase C or protein kinase A. Short-term exposure of the cells to 12-O-tetradecanoylphorbol 13-acetate (TPA) completely suppressed the sulprostone-induced increase in intracellular Ca2+ concentration, while forskolin or dibutyryl cAMP did not affect it, suggesting that protein kinase C but not protein kinase A is involved in the regulation of the EP1 signal transduction. Furthermore, long-term exposure to TPA decreased PGE2 protein kinase A is involved in the regulation of the EP1 signal transduction. Furthermore, long-term exposure to TPA decreased PGE2 binding activity of EP1 due to the reduction of the EP1 mRNA level. Protein kinase C induces short- and long-term desensitization of EP1.

Animals↗
PubMed1995

A nonsense mutation in the 4-hydroxyphenylpyruvic acid dioxygenase gene (Hpd) causes skipping of the constitutive exon and hypertyrosinemia in mouse strain III.

4-Hydroxyphenylpyruvic acid dioxygenase (HPD; EC 1.13.11.27) is an important enzyme in tyrosine catabolism in most organisms. Decreased activity of 4-hydroxyphenylpyruvic acid dioxygenase in the liver of mouse strain III is associated with tyrosinemia. We report a nucleotide substitution that generates a termination codon in exon 7 of the 4-hydroxyphenylpyruvic acid dioxygenase gene in III mice. This mutation is associated with partial exon skipping, and most of the mRNA lacks sequences corresponding to exon 7. The partial exon skipping apparently is the result of a nonsense mutation in the exon. Mouse strain III is a model for human tyrosinemia type 3 (McKusick 276710), and this strain together with recently established models for tyrosinemia type 1 will facilitate studies of hereditary tyrosinemias.

4-Hydroxyphenylpyruvate Dioxygenase↗
PubMed1995

The SMXA: a new set of recombinant inbred strain of mice consisting of 26 substrains and their genetic profile.

A new set of recombinant inbred (RI) strain SMXA consisting of 26 substrains was established between SM/J and A/J. The history of the SMXA RI strains and their genetic profile covering 158 genetic marker loci are reported. From the strain distribution pattern among SMXA RI strains, the chromosomal location of salivary and tear protein genes Spe1-r, Spe1-s, Spe2, and Tpe1 were newly determined.

Animals↗
PubMed1995

Establishment and characterization of a new, spontaneously immortalized, pancreatic ductal cell line from the Syrian golden hamster.

Spontaneously immortal pancreatic cell lines are not available. By use of a defined culture medium, such a line (TAKA-1) was established from the Syrian golden hamster. Cytological, cytogenetic, molecular biological, enzymatic and receptor patterns as well as antigenicity were studied and were compared with those of the normal hamster pancreatic ductal cells in vivo. TAKA-1 cells grew exponentially in a monolayer on collagen gel in a defined medium but did not proliferate in soft agar. Ultrastructurally, the cells closely resembled the normal hamster pancreatic ductal cells. Similarities and dissimilarities were found between the normal ductal cells and TAKA-1 cells. Similarities included the presence of cytokeratin, carbonic anhydrase and some tumor-associated antigens. However, unlike the normal ductal cells, TAKA-1 cells expressed blood group A antigen and anti-vimentin, showed affinity to selected lectins, and an abnormality of chromosome 3, which is suggested to be associated with immortality. Moreover, unlike the hamster pancreatic ductal cancer cells but like the normal hamster pancreatic ductal cells, TAKA-1 cells did not have a c-Ki-ras mutation. EGF, TGF-alpha and secretin, but not CCK or GRP, bound to the TAKA-1 cells. TAKA-1 cells produced TGF-alpha, and their growth was stimulated by exogenous EGF in serum-free medium. This cell line presents a suitable model for biologic and pathologic study of the hamster pancreatic ductal cells in vitro.

Animals↗
PubMed1995

Long-term evaluation of distal splenorenal shunt with splenopancreatic and gastric disconnection.

BACKGROUND: This study was aimed at evaluating advantages of distal splenorenal shunt (DSRS) with splenopancreatic and gastric disconnection (DSRS-SPGD) over DSRS with splenopancreatic disconnection (DSRS-SPD) and standard DSRS (S-DSRS). METHODS: DSRS-SPGD, DSRS-SPD, and S-DSRS were performed on 62, 7, and 55 patients, respectively, from 1970 to 1992. Comparison was performed in the following aspects: (1) long-term results in ratio of rebleeding, survival rate, and quality of life and (2) portal hemodynamics evaluated by preoperative and postoperative angiography. Portal blood flow was assessed by the ratio of the diameter of portal vein (PV) to superior mesenteric vein (SMV), and shunt selectivity was evaluated by selectivity grade. RESULTS: Incidence of rebleeding was significantly lower in patients who underwent DSRS-SPGD than in those who underwent S-DSRS (p < 0.05). Grade 0 and I performance status was better in patients who underwent DSRS-SPGD. Accumulated survival ratio for 5 and 7 years was 78.3% and 70.5% in patients who underwent DSRS-SPGD, 59.7% and 44.1% in patients who underwent S-DSRS, and 75% and 75% in patients who underwent DSRS-SPD. Hemodynamic evaluation showed significantly lower PV/SMV ratio and degree of change in PV/SMV ratio of patients who underwent S-DSRS and DSRS-SPD. Many patients who underwent S-DSRS and DSRS-SPD exhibited loss of shunt selectivity at grades II and III. In contrast, patients who underwent DSRS-SPGD maintained satisfactory PV/SMV ratio and selectivity grade. CONCLUSIONS: DSRS-SPGD clearly showed advantages in decrease of rebleeding and improvement of quality of life resulting from maintenance of shunt selectivity and portal blood flow.

Cause of Death↗
PubMed1995

Differences in molecular biological, biological and growth characteristics between the immortal and malignant hamster pancreatic cells.

We compared morphological, biological and molecular biological patterns of a newly established, spontaneously immortalized pancreatic ductal cell line, TAKA-1, with a hamster pancreatic ductal adenocarcinoma cell line, PC-1. PC-1 cells grew in a monolayer on plastic tissue culture flasks, whereas TAKA-1 cells required type I collagen gel matrix to propagate. The growth rate and argyrophilic nuclear organizer region (Ag-NOR) counts were greater in PC-1 cells than in TAKA-1 cells. More TAKA-1 cells were in G0/G1 and less were in the S cell cycle phase than PC-1 cells. Karyotypically, the consistent change in TAKA-1 cells was an abnormal no. 3 chromosome, whereas additional chromosomal abnormalities were found in PC-1 cells. Ultrastructurally, TAKA-1 cells formed ductal structures and were composed of two types of cells, as in the normal hamster pancreatic ducts, whereas PC-1 cells were pleomorphic, showed evidence for loss of differentiation and contained intracytoplasmic lumens. Unlike the PC-1, TAKA-1 cells did not show a point mutation at codon 12 in the c-Ki-ras oncogene and did not grow in soft agar. Receptor binding assay showed specific epidermal growth factor binding to both cell lines, but secretin binding only to TAKA-1 cells. Both cells produced and released transforming growth factor-alpha in serum-free medium. Both cell lines expressed blood group A antigen, carbonic anhydrase, coexpressed cytokeratin and vimentin, and reacted with tomato and Phaseolus vulgaris leucoagglutinin (L-PHA) lectins. The results demonstrate that chromosomal abnormalities, cell cycle patterns, expression of cytokeratin 18, lectin bindings and the c-Ki-ras mutation are the features that distinguish the benign from the malignant pancreatic ductal cells in Syrian hamster.

Adenocarcinoma↗
PubMed1995

Linkage of the athymic nude locus with the myeloperoxidase locus in the rat.

In rats of the BUF/Mna strain epithelial thymoma development is regulated by a single autosomal susceptible gene, Tsr-1. In pre-thymoma stage, BUF/Mna rats have extremely large thymuses, when compared with those of other strains of rats. The large thymus size of this strain is contributed by a thymus-enlargement gene, Ten-1. On the other hand, reduced thymus size and suppression of thymoma development were found in heterozygous BUF/Mna-rnu/+ rats. Linkage studies between RNU and microsatellite and restriction fragment length polymorphism markers in ([BUF/Mna-rnu/rnu x WKY/NCrj] F1 x WKY/NCrj)- and (WKY/NCrj x [BUF/Mna-rnu/rnu x WKY/NCrj] F1)- backcross rats have led to the localization of RNU on chromosome 10. The rat homolog of mouse Mpo (myeloperoxidase) was also assigned to the chromosome 10. The gene order on the chromosome was MYHSE (myosin heavy chain of embryonic skeletal muscle)--(1.0 centimorgan [cM])--SHBG (sex hormone-binding globulin)--(4.0 cM)--RNU (Rowett rat nude)--(10.0 cM)--MPO--(13.0 cM)--AEP (anion exchange protein). Conserved linkage of homologous loci mapped to rat chromosome 10 and mouse chromosome 11 supports the hypothesis that the RNU and MPO loci are rat homologs of the mouse nu and Mpo loci.

Animals↗
PubMed1995

Na+/H+ and Na+/Ca2+ exchange in regulation of [Na+]i and [Ca2+]i during metabolic inhibition.

The relationships among intracellular Na+ and Ca2+ concentrations ([Na+]i and [Ca2+]i, respectively) and cell morphology were investigated during metabolic inhibition (MI) in isolated guinea pig myocytes. [Na+]i and [Ca2+]i were measured using the fluorescent indicators, Na(+)-binding benzofuran isophthalate and fluo 3. During the initial 20 min of MI, [Na+]i increased from 6.2 +/- 0.5 to 18.6 +/- 1.6 mM (n = 31), whereas [Ca2+]i, expressed as the percent change of fluo 3 fluorescence, remained at the low level. In the following 30 min, 94% of the cells developed contracture, and [Ca2+]i began to increase after cells had contracted (167 +/- 14% at 50 min). The level of [Ca2+]i during MI was lower than that during 500 microM strophanthidin perfusion. The increase in [Na+]i was not affected by 10 microM tetrodotoxin but was suppressed by 1 microM hexamethylene amiloride (HMA). The application of 10 mM glucose from the start of MI prevented both the increase in [Na+]i and cell contracture. However, the addition of glucose after 20 min of MI [energy repletion (ER)] led to a dramatic increase in [Ca2+]i (442 +/- 72% at 50 min, n = 31), and 84% of the cells developed contracture. The increase in [Ca2+]i and the cell contracture were suppressed by HMA or Ca(2+)-free solution. Intracellular pH decreased from 7.23 +/- 0.07 to 6.95 +/- 0.09 during MI but did not change after ER (6.90 +/- 0.11 at 35 min, n = 9). These findings suggested that during MI 1) [Na+]i increased by both the activated Na+ influx via Na+/H+ exchange and the suppressed Na+ extrusion via the Na+/K+ pump, 2) Na+/Ca2+ exchange was inhibited by energy depletion and intracellular acidosis, and 3) cell contracture was not related to Ca2+ overload but was related to rigor due to energy depletion.

Amiloride↗
PubMed1995

Salt-sensitive hypertension in transgenic mice overexpressing Na(+)-proton exchanger.

Essential hypertension is one of the most common diseases that exacerbate the risk of cardiovascular or cerebrovascular attacks. Although the etiology of essential hypertension remains unclear, recent investigations have revealed that an enhancement of Na(+)-proton (Na(+)-H+) exchange activity is a frequently observed ion transport abnormality in hypertensive patients and animal models. To test the hypothesis that increased Na(+)-H+ exchange causes hypertension, we produced transgenic mice overexpressing Na(+)-H+ exchanger and analyzed their Na+ metabolism and blood pressure. Urinary excretion of water and Na+ was significantly decreased in transgenic mice, and systolic blood pressure was elevated after salt loading. The impaired urinary excretion of Na+ suggested that the Na(+)-H+ exchanger overexpressed in the renal tubules increased reabsorption of Na+, which caused a blood pressure elevation by Na+ retention after excessive salt intake. Our results demonstrate that overexpression of Na(+)-H+ exchanger can be a genetic factor that interacts with excessive salt intake and causes salt-sensitive blood pressure elevation.

Animals↗
PubMed1995

Intracellular sodium concentration in diabetic rat ventricular myocytes.

We measured intracellular NA+ concentration ([Na+]i) of diabetic rat ventricular myocytes using sodium-binding benzofuran isophthalate (SBFI). We used diabetic rats at 8 weeks after the injection of streptozotocin (45 mg/kg i.v.). The level of [Na+]i during the control perfusion was significantly lower in diabetic myocytes than that in normal myocytes (9.2 +/- 0.4 mM v.s. 12.0 +/- 0.3 mM, p < 0.01). After the 40 min perfusion of 1 microM hexamethylene amiloride (HMA), [Na+]i decreased significantly in both groups. However, there was no difference in [Na+]i between the two groups after the perfusion of HMA. It was suggested that the lower [Na+]i in diabetic myocytes could be due to the decreased activity of Na+/H+ exchange system.

Amiloride↗
PubMed1995

Viability of partial liver graft from living donor in pigs.

For evaluation of the viability of partial liver graft from a living donor, we investigated energy production of mitochondria and radical scavenging enzyme activities in partial and whole liver transplantation in pigs. The values of adenosine triphosphate (ATP) and total adenine nucleotide (TAN) of the partial liver graft were higher than those of the whole liver graft, whereas the hypoxanthine of the partial liver graft was lower than that of the whole liver graft. There was no statistical difference in the radical scavenging enzyme activities between the two groups. The values of respiratory control ratio (RCR) in both groups were above 3.0 and there was no statistical difference. The survival rates of pigs received partial liver and whole liver graft with 2 to 3 hr cold preservation was 71% and 91%, respectively and there was no statistical difference between two groups. These results suggest that viabilities of the partial liver graft from the living donor are satisfactory enough, compared with those of whole liver graft from a cadaver.

Adenine Nucleotides↗
PubMed1995

Changes in the mouse exocrine pancreas after pancreatic duct ligation: a qualitative and quantitative histological study.

The pancreatic duct from the splenic lobe, the largest lobe of the pancreas in the mouse, was ligated at 6 weeks of age, with histological and cytological changes in the organ examined 1 day to 16 weeks after the ligation. Changes in the volumes of the pancreatic lobe, exocrine tissue, and interstitial tissue as well as relative total numbers of each cellular element in the organ after duct ligation were stereologically obtained using serial sections of the whole pancreas. Cell sizes, degenerated cell and mitotic cell indices, and nuclear densities of the acinar and ductal cells were also obtained. After duct ligation, the volume of the pancreas increased by interstitial edema in the first 2 days but rapidly decreased thereafter due to atrophy of the exocrine tissue, amounting to 10% or less of normal volume by 7 days. The acinar cells showed an accumulation of the zymogen granules, cytoplasmic condensation and a pyknotic figure of the nucleus; they then were thoroughly deleted with appearance of numerous macrophages. This cell death was suggested to be due to apoptosis. On the other hand, the ductal cells remained in the atrophic pancreas and proliferated with mitotic figures to two times the normal frequency at 3 days, and then formed duct-like structures lacking in the acinar cells. After 2 week, the ductal cells slowly decreased in number also due to cell death, but the pancreas became gradually enlarged by intralobular fatty replacement, to reach a volume approximating that of normal 8 weeks after duct ligation. The stereological method serves for the correct evaluation of cell dynamics including the deletion and proliferation of the cells in the whole organ.

Animals↗
PubMed1995

Monamidocin, a novel fibrinogen receptor antagonist. II. Biological activity and structure-activity relationships.

Monamidocin, a fibrinogen receptor binding inhibitor produced by Streptomyces sp. NR 0637, inhibits the binding of fibrinogen to its receptor with an IC50 of 0.21 microM. It also inhibits ADP-collagen- and thrombin-induced aggregation of human platelet with IC50S of 46, 30, and 77 microM, respectively. To obtain more potent inhibitors, twenty analogs have been synthesized, among which N-[(R)-5-guanidino-2-hydroxypentanoyl]-L-tyrosine is the most potent. It inhibits the binding of fibrinogen to its receptors with an IC50 of 0.022 microM and is about ten times more potent than monamidocin.

Adenosine Diphosphate↗