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Biomedical subjects

E Uchida

Publications and source records attributed to E Uchida.

At least 127 records · Page 7Linked to original sources
PubMed1989

Structure and activity of artificial mutant variants of human growth hormone.

Four artificial mutant variants of human growth hormone (hGH) with the following characteristics were prepared in Escherichia coli by in vitro mutagenesis: (i) replacement of Trp86 with Tyr (W86Y hGH); (ii) deletion of Trp86 (delta W86 hGH); (iii) deletion of residues 32-46 (20-kd-hGH); and (iv) deletion of residues 32-71 (17.5-kd-hGH). Both W86Y hGH and delta W86 hGH have a point mutation at Trp86 which is the only Trp residue in hGH and is conserved among members of the growth hormone family. 20-kd-hGH is a minor component of hGH in the pituitary gland and plasma and is the result of an alternative splicing of the primary gene transcript, while only the corresponding mRNA and not the protein has been found in the case of 17.5-kd-hGH. The biological activities (adipogenic activity and potentiation of gain in body weight) and structures (as analyzed by circular dichroism) were mostly retained by the W86Y, delta W86 and 20-kd-hGH variants but not by 17.5-kd-hGH.

Adipose Tissue↗
PubMed1989

Antipyrine metabolism in female Lewis and Dark Agouti strains of rats, which are extensive and poor metabolizers of debrisoquine, respectively.

The metabolism of antipyrine (AP) was investigated in female rats of the Dark Agouti (DA) and Lewis (L) strains, which have been proposed as models for human poor and extensive metabolizers of debrisoquine (DB), respectively. Following i.p. injection of 50 mg/kg of AP, the rate of production of 4-hydroxy-antipyrine in 24-hr urine was increased significantly in the L strain. The results suggested that different cytochrome P-450 isozymes were responsible for hydroxylation of AP and DB and showed interphenotype differences between the two strains.

Animals↗
PubMed1989

Immunohistochemical localization of Na+, K+-ATPase in human normal and malignant pancreatic tissues.

Localization of Na+, K+-ATPase in the human pancreas was investigated immunohistochemically using rabbit antisera against Na+, K+-ATPase of the human kidney. The reaction product existed only on the luminal surfaces of both centroacinar and ductal cells in normal pancreatic tissue, whereas in chronic pancreatitis the localization of Na+, K+-ATPase was found frequently on the luminal surfaces of both centroacinar and ductal cells, and on the basolateral surfaces of some ductal cells. However, in acinar cells, the distribution of Na+,K+-ATPase was not detected in either the normal pancreas or chronic pancreatitis. In pancreatic carcinoma tissues, Na+,K+-ATPase existed very rarely in malignant cells. These results indicate that Na+,K+-ATPase is immunohistochemically localized on the membranes of centroacinar and ductal cells of the human pancreas, and that the antigenicity of Na+,K+-ATPase in pancreatic carcinoma cells differs from that in normal cells.

Chronic Disease↗
PubMed1989

Structural characteristics of growth hormone receptors on mouse 3T3 cells having different biological responses to growth hormone.

Cultured 3T3-F442A preadipocytes are able to undergo GH-promoted differentiation into adipocytes. The relationship between the structure and function of GH receptors on 3T3 cells (3T3-F442A preadipocytes, differentiated adipocytes and 3T3-C2 cells, which vary in susceptibility to adipose conversion or with respect to carbohydrate and lipid metabolism) was studied by the covalent cross-linking of 125I-labelled human (h) GH to intact cells with the bifunctional reagent disuccinimidyl suberate. When preadipocytes were cross-linked and analysed using sodium dodecylsulphate-polyacrylamide gel electrophoresis, a prominent 125I-labelled hGH-receptor complex of Mr 130,000 was observed along with minor complexes (Mr 300,000, 230,000 and 60,000) on autoradiography. Non-reducing-reducing two-dimensional gel electrophoresis revealed that the higher molecular weight complexes also contained the Mr 130,000 complex. Neuraminidase and tunicamycin treatment demonstrated that the GH receptor on F442A preadipocytes is a sialo-glycoprotein with N-linked carbohydrate chains. When the differentiated 3T3-F442A adipocytes and 3T3-C2 cells (a sub-line with no susceptibility to adipose conversion with GH) were examined in the same way as 3T3-F442A preadipocytes, no differences were observed in the specificity of GH binding and in the molecular size of the 125I-labelled hGH-receptor complexes and their glycosylation characteristics. This suggests that the structural characteristics of the GH receptor are closely related in each cell type, but that the hormonal signals produced after GH binding to the receptor may cause different effects according to the cell type.

Adipose Tissue↗
PubMed1989

Changes in the pulsatile secretion of LH after the removal of and subsequent resuckling by pups in ovariectomized lactating rats.

Changes in the pulsatile secretion of LH after removal of pups and subsequent resuckling were examined in ovariectomized lactating rats, and the change after removal of pups was compared with that after the removal of ovaries in cyclic female rats. The day of parturition was designated day 0 of lactation. All lactating rats were ovariectomized on day 2 of lactation. They were deprived of their pups for 6, 12, 18, 24 or 45 h before blood sampling on day 8 of lactation, or were resuckled by their pups for 1, 4, 7 or 12 h before blood collection after separation from pups for 24 h. Cyclic female rats were ovariectomized on the day of dioestrus and blood samples were taken 12, 18, 24 or 48 h or 6 days after ovariectomy. Typical LH pulses appeared in some animals from 12 h after the removal of pups. The mean LH level and the frequency and amplitude of LH pulses gradually increased after removal of pups, until after 45 h of separation the frequency reached the high level observed 6 days after ovariectomy in cyclic rats. The subsequent resuckling by pups after a 24-h separation decreased these three parameters of LH pulses rapidly. In contrast, the frequency of LH pulses was unchanged after ovariectomy in cyclic rats, although the mean LH level and the amplitude of LH pulses increased. These results suggest that the suckling stimulus suppresses pulsatile LH secretion in a different manner from that of ovarian steroids.

Animals↗
PubMed1989

Co-expression of CA 19-9, DU-PAN-2, CA 125, and TAG-72 in pancreatic adenocarcinoma.

Various tumor-associated antigens have been reported in pancreatic adenocarcinoma tissue. This study examines the incidence and co-expression of CA 19-9, DU-PAN-2, CA 125, and TAG-72 in serum and cancer tissue from patients with pancreatic cancer. In tissue, 83% of the cases demonstrated co-expression of three or more antigens. The incidence of antigen expression was comparably high for CA 19-9, DU-PAN-2, and TAG-72; however, significantly more cancer cells within each sample demonstrated CA 19-9. Serologic co-expression of elevated antigen levels was less common; only 39% of the patients showed increased circulating levels of three or more antigens. The predictive value of tissue immunoreactivity for elevated circulating levels of antigen was strongest for CA 19-9. Immunoreactivity patterns in cancer tissue suggest that the epitopes for these antigens are distinct, and DU-PAN-2 antigen was identified in patients who could not manufacture CA 19-9 (a sialylated Lea antigen). However, a strong correlation between circulating levels of CA 19-9 and DU-PAN-2 supports the contention that these two antigens are incidentally expressed on the same mucin molecule.

Adenocarcinoma↗
PubMed1988

Comparative studies on the expression of tumor-associated glycoprotein (TAG-72), CA 19-9 and DU-PAN-2 in normal, benign and malignant pancreatic tissue.

Expression of tumor-associated glycoprotein (TAG-72) was examined by immunohistochemistry in pancreatic specimens from normal donors, and from patients with chronic pancreatitis and pancreatic cancer, and was compared with expression of CA 19-9 and DU-PAN-2. In the normal pancreas, TAG-72 was expressed in fewer ductal and ductular cells than were CA 19-9 (p less than 0.05) and DU-PAN-2 (p less than 0.01 and 0.001 respectively), whereas in chronic pancreatitis all 3 antigens were expressed in ductal cells but only CA 19-9 and DU-PAN-2 in ductular cells (p less than 0.001). In the specimens from normal pancreas and chronic pancreatitis cases, TAG-72 was localized in the Golgi region, whereas CA 19-9 and DU-PAN-2 showed diffuse cytoplasmic and glycocalyx patterns. In pancreatic cancer, although the rate of expression of all 3 antigens was similar, their cellular localization differed significantly: only TAG-72 was expressed in the Golgi region (p less than 0.001), whereas CA 19-9 showed mainly glycocalyx (p less than 0.05) and/or intra-luminal patterns (p less than 0.01) compared with that of the other 2 antigens. We conclude that, due to differences in expression of TAG-72 in benign versus malignant cells, the monoclonal antibody against TAG-72 (B72.3) may be suitable for radio-immunodetection or radio-immunotherapy of pancreatic cancer.

Adenocarcinoma↗
PubMed1988

Expression of blood group-related antigens ABH, Lewis A, Lewis B, Lewis X, Lewis Y, and CA 19-9 in pancreatic cancer cells in comparison with the patient's blood group type.

Blood group A, B, H, Le, Leb, Lex, and Ley antigenicity as well as the expression of CA 19-9 were examined in pancreatic cancer specimens from 30 patients, using monoclonal antibodies to the respective antigen and immunohistochemical techniques, and the findings were correlated with the blood group types (ABO and Lewis) of the individuals. Compatible antigen expression was found in 82, 75, and 50% of tumors from patients with A, B, and O blood group types, respectively. Deletion of the compatible antigen was found in 10 (33%) of the cases, predominantly in patients of blood group O type, and incompatible expression (of B antigen only) in 4 (13%). Lea was detected in 87%, Leb in 90%, Lex in 30%, and Ley in 43% of the specimens, regardless of ABH and Lewis phenotype of the patients. Coexpression of Lea and Leb was found in 87%, of Lex and Ley in 13%, of Lea and Lex in 23%, and of Leb and Ley in 40% of the cases. CA 19-9 was expressed in 80% of the tumors; it was present in the tumor tissue of 21 of 22 patients from Lea-b+, in all 4 individuals from Lea+b-, but in none of the 4 patients from Lea-b- phenotype (P less than 0.01). Heterogeneity in the expression of each of the antigens was found. The overall results indicate that blood group antigen expression in pancreatic tumor differs from that of other gastrointestinal cancers and that the Lewis antigen expression in pancreatic cancer cells is independent of the blood group phenotype of the patients and thus may be useful as a tumor marker.

ABO Blood-Group System↗
PubMed1988

Correlative study on expression of CA 19-9 and DU-PAN-2 in tumor tissue and in serum of pancreatic cancer patients.

The serum levels of CA 19-9 and DU-PAN-2 antigens and their expression in tumor tissue were examined in 22 pancreatic cancer patients and the results were correlated with the Lewis (Le) blood group phenotypes of the individuals. In tumor tissue, CA 19-9 was expressed in 17 of 22 (77%) specimens. The negative cases included three patients with Lea-b-, one with Lea+b- and the other with Lea-b+ phenotypes. DU-PAN-2 antigen was expressed in 20 of 22 (91%) cancer tissues. The two DU-PAN-2-negative cases were CA 19-9-positive. The combination of two markers increased the sensitivity to 100%. In the serum, CA 19-9 level was elevated (greater than 37 U/ml) in 16 of 21 (73%) cases. All Lea-b- patients had values less than 37 U/ml. An elevated level of DU-PAN-2 (greater than 300 U/ml) was detected in 14 of 21 (67%) patients including three cases with Lea-b- type. In only one patient were both antigens below the cutoff levels so that the combination of two biomarkers elevated the sensitivity to 95%. The study indicated that the cocktail of 19-9 and DU-PAN-2 antibodies might increase the sensitivity and specificity for clinical diagnosis of pancreatic cancer. In 19 of 21 (90%) cases, the serum CA 19-9 level correlated with the expression of the antigen in the cancer tissue. Discrepancy was seen in two cases; one patient had an elevated level of CA 19-9 in the serum, but lacked this antigen in the cancer cells. In the second case, the situation was reversed. For DU-PAN-2, positive correlation was seen in 14 of 21 (67%) cases. Six of seven patients with low DU-PAN-2 levels expressed the antigen in their tumor cells, and one patient with DU-PAN-2-negative cancer tissue had an elevated level of this marker in the serum. Thus, CA 19-9 expression in serum corresponded more closely to expression in tissue than did that of DU-PAN-2 antigen. The serum levels of these antigens, however, is likely due to multiple factors, only one of which is the qualitative and quantitative expression of the antigens in tumors.

Adult↗
PubMed1988

Characterization and function of catalytic subunit alpha of H+-translocating adenosine triphosphatase from vacuolar membranes of Saccharomyces cerevisiae. A study with 7-chloro-4-nitrobenzo-2-oxa-1,3-diazole.

Subunit alpha (Mr 89,000) from vacuolar membrane H+-translocating adenosine triphosphatase of the yeast Saccharomyces cerevisiae was found to bind 8-azido[alpha-32P]adenosine triphosphate. Labeling by this photosensitive ATP derivative was saturable with an apparent dissociation constant of 10(-6) to 10(-5) M and decreased in the presence of ATP and ADP. The enzyme was inactivated by 7-chloro-4-nitrobenzo-2-oxa-1,3-diazole (NBD-Cl), with about 1 microM causing half-maximal inactivation in the neutral pH range. This inactivation was prevented by the presence of ATP, ADP, or adenosyl-5'-yl imidodiphosphate (AMP-PNP). The original activity was restored by treating the inactivated enzyme with 2-mercaptoethanol. Kinetic and chemical studies of the inactivation showed that the activity was lost on chemical modification of a single tyrosine residue per molecule of the enzyme. When the enzyme was inactivated with [14C]NBD-Cl, subunit alpha was specifically labeled, and this labeling was completely prevented by the presence of ATP, GTP, ADP, or AMP-PNP. From these results, it was concluded that subunit alpha of yeast vacuolar H+-ATPase has a catalytic site that contains a single, essential tyrosine residue. The kinetics of single site hydrolysis of [gamma-32P]ATP (Grubmeyer, C., Cross, R. L., and Penefsky, H. S. (1982) J. Biol. Chem. 257, 12092-12100) indicated the formation of an enzyme-ATP complex and subsequent hydrolysis of bound ATP to ADP and Pi at the NBD-Cl-sensitive catalytic site. NBD-Cl inactivated the single site hydrolysis and inhibited the formation of an enzyme-ATP complex. Dicyclohexylcarbodiimide did not affect the single site hydrolysis, but inhibited the enzyme activity under steady-state conditions.

4-Chloro-7-nitrobenzofurazan↗
PubMed1988

Effects of insulin, dexamethasone and glucagon on the production of apolipoprotein A-I in cultured rat hepatocytes.

Cultured rat hepatocytes were used to study the effects of hormones on the production of apo A-I. In addition, we compared these effects with the production of albumin. Hepatocytes were isolated from normal adult rat livers and cultured in MEM, as nearly confluent monolayers. In the absence of hormones, apo A-I and albumin accumulated in the culture medium almost linearly for periods up to 24 h. The rates of accumulation of apo A-I and albumin in the medium were 22 ng/mg cell protein per h and 1.2 micrograms/mg cell protein per h, respectively. During the incubations the cellular contents of apo A-I remained constant. Insulin stimulated the production of albumin at concentrations over 10(-10) M, but inhibited the production of apo A-I at concentrations over 10(-8) M. Dexamethasone showed no significant effects on albumin production but stimulated apo A-I production at concentrations over 10(-6) M. Glucagon inhibited the production of albumin and apo A-I dose-dependently at concentrations over 10(-10) M. Thus, the production of albumin and apo A-I are presumably controlled by different regulatory mechanisms.

Albumins↗
PubMed1988

The effects of malotilate on hepatic drug metabolizing systems in different strains of rats.

1. In Sprague-Dawley (SD) rats treated for 7 days with malotilate (MAL:250 mg/kg, p.o.), cytochrome P-450 and b5 contents, aminopyrine N-demethylase and heme oxygenase activities were significantly increased. In Wistar rats, cytochrome b5 content and heme oxygenase and delta-aminolevulinic acid synthetase activities were found to be significantly increased. 2. Among the antipyrine metabolites excreted in urine during the 24 hr after antipyrine (100 mg/kg, i.p.) administration, norantipyrine increased significantly in Sprague-Dawley rats, while a significant increase of 4-hydroxyantipyrine was observed in Wistar rats. 3. The serum dimethadione/trimethadione ratio was only found to be significantly increased in Sprague-Dawley rats. 4. These results indicate that malotilate may have inducible effects on hepatic drug metabolizing enzymes, and that it affects the various cytochrome P-450 isozymes from different strains of rat in different ways.

Alkaline Phosphatase↗
PubMed1988

Ocular hypotensive effects of monoamine oxidase-A inhibitors in rabbit.

The effects of monoamine oxidase-A (MAO-A) inhibitors with epinephrine on intraocular pressure in the pigmented rabbit were studied. MAO-A inhibitors were used topically with or without various concentrations of epinephrine. For the measurement of intraocular pressure, applanation pneumatonography was used and tissue MAO activities were determined by radiometric assay. After topical administration with clorgyline, MAO-A activities in the bulbar conjunctiva and the iris-ciliary body were remarkably inhibited, whereas MAO-B inhibition was minimal. Maximal reduction of intraocular pressure with 0.05% epinephrine was 3.2 mmHg. Single administration of clorgyline, amiflamine, moclobemide or CGP 11305-A caused decreases in the intraocular pressure of 2.0, 2.5, 1.8 and 2.4 mmHg, respectively. In the coadministration experiments with epinephrine, the ocular hypotensive effects of epinephrine were potentiated with clorgyline, amiflamine, moclobemide and CGP 11305-A (6.6, 4.8, 5.6 and 5.8 mmHg). On the contrary, they were not influenced by the MAO-B inhibitor deprenyl. These results indicated that MAO-A inhibitors potentiated the ocular hypotensive effects of epinephrine, and that the coadministration of a reversible MAO-A inhibitor with epinephrine might be useful for patients with glaucoma.

Animals↗