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H Endo

Publications and source records attributed to H Endo.

At least 19 recordsLinked to original sources
PubMed1992

Depression of catalase gene expression in the liver of tumor bearing nude mice.

Based on the classical observation that catalase activity is reduced in the liver of a tumor bearing host, we studied this phenomenon from the aspect of gene expression. Northern blot analysis on the livers of mice with a rat tumor showed that the catalase gene expression is lowered in a tumor size-dependent fashion. Decreased gene expression was also seen irrespective of tissue or species origin of tumors transplanted. Removal of the implanted tumor resulted in restoration of the reduced gene message to the normal level. The tumor effect on the catalase gene expression was shown to be controlled at the transcriptional level. These results strongly suggest that the reduction of liver catalase activity in the tumor bearer may be due to down regulation of the catalase gene induced in the liver by a certain humoral factor(s) from the transplanted tumor.

Animals↗
PubMed1992

Epidermal growth factor stimulates mouse placental lactogen I but inhibits mouse placental lactogen II secretion in vitro.

This study was undertaken to determine whether epidermal growth factor (EGF) regulates the secretion of mouse placental lactogen (mPL)-I and mPL-II. Primary cell cultures were prepared from placentas from days 7, 9, and 11 of pregnancy and cultured for up to 5 days. Addition of EGF (20 ng/ml) to the medium resulted in significant stimulation of mPL-I secretion by the second day of culture in cells from days 7 and 9 of pregnancy and significant inhibition of mPL-II secretion by the third or fourth day of culture in cells from days 7, 9, and 11. Dose-response studies carried out with cells from day 7 of pregnancy demonstrated that the minimum concentration of EGF that stimulated mPL-I secretion and inhibited mPL-II secretion was 1.0 ng/ml. EGF did not affect the DNA content of the cells or cell viability, assessed by trypan blue exclusion, nor did it have a general effect on protein synthesis. There are three types of PL-containing giant cells in mouse placental cell cultures: cells that contain either mPL-I or mPL-II and cells that contain both hormones. Immunocytochemical analysis and the reverse hemolytic plaque assay indicated that EGF treatment was accompanied by a significant increase in the number of cells that produce mPL-I, but among the PL cells that contained mPL-I, there was no change in the fraction of cells that contained only mPL-I or the fraction that contained both mPL-I and mPL-II. In contrast, EGF treatment did affect the distribution of mPL-II among PL cells. In control cultures, about 75% of the cells that contained mPL-II also contained mPL-I, but in EGF-treated cultures, all of the cells that contained mPL-II also contained mPL-I. These data suggest that EGF regulates mPL-I and mPL-II secretion at least partly by regulating PL cell differentiation.

Animals↗
PubMed1992

The primary structure of mouse saposin.

The primary structure of mouse sphingolipid activator protein (saposin) was determined by cDNA sequencing. The amino acid sequence predicted by the cDNA sequence revealed that mouse saposin was highly homologous to human saposin and also to rat sertoli cell glycoprotein. Mouse saposin also has four functional domains, which are structurally similar to each other, and each domain has cysteines, prolines, and a potential glycosylation site at an almost identical position. An amino acid comparison between human and mouse saposins revealed that the similarity was approximately 70%, and human saposin lacks thirty-one amino acids between domains C and D. Heterogeneities of mRNA were found in both the coding and noncoding regions.

Amino Acid Sequence↗
PubMed1992

Beneficial effects of dietary intervention on serum lipid and apolipoprotein levels in obese children.

Effects of weight reduction on serum levels of lipids and apolipoproteins were measured in 13 obese children (seven girls, six boys). Mean weight loss of 8.4% of the initial body weight was achieved after 4 weeks of energy intake restriction and exercise. Serum total cholesterol (5.46 +/- 1.01 mmol/L) and triglyceride (2.08 +/- 0.52 mmol/L) levels were significantly high compared with control values before treatment and were significantly reduced to 4.32 +/- 0.75 and 1.31 +/- 0.42 mmol/L, respectively, after treatment. Serum high-density lipoprotein cholesterol level (1.03 +/- 0.23 mmol/L) was significantly low and unchanged after treatment (0.94 +/- 0.25 mmol/L). Serum apolipoprotein A-I level (0.039 +/- 0.009 mmol/L or 111 +/- 0.26 g/L) was normal before treatment and significantly reduced, to 0.032 +/- 0.007 mmol/L or 0.92 +/- 0.19 g/L, after weight reduction. Serum apolipoprotein B level (0.00019 +/- 0.00007 mmol/L or 1.07 +/- 0.21 g/L) was significantly high before treatment and decreased to the normal range after treatment (0.00014 +/- 0.0009 mmol/L or 0.76 +/- 0.24 g/L). The ratio of apolipoprotein B to apolipoprotein A-I (1.09 +/- 0.29) was significantly high on admission and decreased significantly to 0.64 +/- 0.12 after treatment. Serum apolipoprotein E level (0.0014 +/- 0.0006 mmol/L or 0.05 +/- 0.02 g/L) was normal and decreased to 0.0008 +/- 0.0002 mmol/L or 0.03 +/- 0.01 g/L after treatment. In conclusion, weight reduction achieved by energy intake restriction and exercise had beneficial effects on serum lipid and apolipoprotein concentrations for the prevention of future atherosclerosis.

Adolescent↗
PubMed1992

Nerve growth factor receptor gene expression in human peripheral blood lymphocytes in aging.

Nerve growth factor (NGF) has a modulating effect on immune function, which may occur as a consequence of binding to the NGF receptor (NGF-R). To determine if mRNA for the gene coding for p75NGFR (low affinity NGF-R) is present in lymphocytes, Northern blot analysis of mRNA from human peripheral blood lymphocytes (PBL) and purified T lymphocytes was initiated using cDNA probe for human p75NGFR. p75NGFR mRNA was present in PBL and T lymphocytes, and the mRNA in response to phytohemagglutinin stimulation showed maximum levels at 14 hr of stimulation. p75NGFR mRNA content when analyzed in PBL and T cells from volunteers of various ages showed that p75NGFR mRNA expression does not change with the age of the cell donor.

Adult↗
PubMed1992

Production of interleukin 8 by cultured synovial cells in response to interleukin 1 and tumor necrosis factor.

Both interleukin 1 alpha (IL-1 alpha) and tumor necrosis factor alpha (TNF alpha) stimulated the production of interleukin 8 (IL-8) by synovial cells in time and dose dependent manners. Enhanced chemotactic activity of polymorphonuclear cells (PMN) in culture supernatants of synovial cells was neutralized with anti-IL-8 antibody, thus showing synovial cells to be capable of secreting IL-8 which may contribute to PMN accumulation in rheumatoid inflamed joints.

Cells, Cultured↗
PubMed1992

Hepatitis type C virus infection in patients with type B chronic liver disease.

Anti-c100-3 (Ortho) was determined in the sera of 152 patients with HBs antigen-positive chronic liver diseases to assess coinfection of hepatitis B virus (HBV) and hepatitis C virus (HCV). Eleven patients (7.2%) were positive for anti-c100-3. Anti-CP-9 (Okamoto) and HCV-RNA (RT-PCR) were also examined in these 11 patients. Anti-CP-9 was detected in 7 patients and HCV-RNA was detected in all 11 patients. Four of the 11 anti-c100-3-positive patients were positive for HBe antigen (HBeAg) and others were negative. In 8 of the 11 patients, HCV was suspected to be superinfected by blood transfusion. In HBeAg-positive patients, serum glutamic pyruvic transaminase (SGPT) was elevated in relation to active replication of HBV shown by DNA-polymerase activity. The histological findings showed chronic active hepatitis, with or without cirrhosis. On the other hand, in HBeAg-negative patients, SGPT fluctuated without evidence of active replication of HBV. Active inflammation in the liver was observed in 3 of 5 HBeAg-negative patients by liver biopsy. These findings suggest that HBV might play an important role in chronic active inflammation in HBeAg-positive patients coinfected with HCV, and that HCV might be responsible for continuous inflammation in HBeAg-negative patients coinfected with HCV.

Adult↗
PubMed1992

Changes in expression of the endogenous beta-galactoside-binding 14-kDa lectin of chick embryonic skin during epidermal differentiation.

Changes in the expression pattern of the gene for the endogenous beta-galactoside-binding 14-kDa lectin of chick embryo were examined immunohistochemically during epidermal differentiation in vivo and in vitro with special reference to detailed localization of the 14-kDa lectin. The gene expression was visualized by the HRP-staining method following in situ hybridization, in which sulfonated cDNA was employed as a probe. The 14-kDa lectin gene expression (mRNA) was detected mainly in the intermediate layer of the epidermis: it was faint in 13-day-old embryos, gradually increased in intensity during epidermal differentiation, and became intensely positive in 17-day-old embryo. The expression of the gene in skin explants was suppressed by vitamin A, which induces mucous metaplasia of the epidermis in vitro. The anti-14-kDa lectin reaction was positive mainly in the intermediate layer of the differentiating epidermis, coinciding chronologically with expression of the gene at the light microscopic level. Immunoelectron microscopy revealed that the positive reaction was primarily localized in desmosomes, in tonofilament bundles anchored to the desmosomes, along the outer surface of the plasma membrane, and in the intercellular space. Essentially the same staining pattern was observed in differentiating epidermis in vitro. The positive reaction was markedly reduced in the epidermis in which differentiation had been suppressed in vitro by the addition of vitamin A.

Animals↗
PubMed1992

Alzheimer disease brain extract stimulates branching of laminin-mediated neuronal processes.

Patients with Alzheimer disease (AD) suffer mental deterioration associated with neurofibrillary tangle and senile plaque formation in the brain. Here we have determined the effects of brain extracts from normal and from AD patients on neuronal process formation by a pheochromocytoma (PC-12) and a neuroblastoma x glioma hybrid cell line (NG108-15). PC12 cells show a dose-related stimulation of branching of neuronal processes by AD brain extracts with cells cultured on a laminin substrate. The neurotrophic effects of extracts of AD brains may be related to the abnormal sprouting and neurofibrillary tangle formation observed in the brain in this disorder.

Adrenal Gland Neoplasms↗
PubMed1992

Negative regulation of catalase gene expression in hepatoma cells.

For an understanding of the molecular basis of the marked decrease in catalase activity of various tumor cells, expression of the catalase gene was studied in rat and human hepatoma cell lines and in rat liver, which was used as a control with high activity. RNA blot hybridization profiles and run-on assays indicated that the decrease in catalase activity was due to depression of catalase gene transcription. Chloramphenicol acetyltransferase (CAT) assays for the fragments with various lengths of the 5'-flanking region (up to -4.5 kb from the ATG codon) of the catalase gene revealed the presence of several cis-acting elements involved in the negative regulation of transcription. The most-upstream element with the strongest activity (-3504 to -3364 bp), when linked to the catalase promoter region (-126 bp) of the CAT construct and subjected to an in vitro transcription assay, did not yield transcripts in experiments with the hepatoma nuclear extract, whereas the unlinked template did yield transcripts. A gel shift competition assay using hepatoma nuclear extract showed the core sequence of the silencer element to be 5'-TGGGGGGAG-3'. A homology search found that the same core sequence was also present in 5'-flanking regions of the albumin gene and of some other liver enzyme genes, the expression of which has been reported to be down regulated in some hepatoma cells. Southwestern (DNA-protein) analysis demonstrated that an approximately 35-kDa nuclear protein bound to the silencer element was present in hepatoma cells but not in rat liver cells.

Animals↗
PubMed1992

Effect of duodenal mucosal blood flow on duodenal alkaline secretion in rats.

To investigate the role of duodenal mucosal blood flow (DMBF) in the regulation of duodenal alkaline secretion (DAS), both parameters were measured before and after the administration of various drugs in rats. The DMBF was determined using an electrolytically generated hydrogen gas clearance technique, and the DAS was measured by the perfusion method. The administration of dulcerozine, a potent duodenal ulcerogenic agent, at a dose of 250 mg/kg and serotonin at a dose of 20 mg/kg, which produces duodenal ulcerations with an acid load, decreased both DMBF and DAS. On the other hand, the administration of secretin at a dose of 10 U/kg increased both parameters. There were parallel changes in DMBF and DAS. It is concluded, therefore, that DAS may be regulated by DMBF and that both parameters may be involved in the defense mechanism of duodenal mucosa.

Alkalies↗
PubMed1992

A probable case of superfecundation.

Discordant twins are of obstetrical concern because of high morbidity and mortality of either the smaller or the larger twin, or both. The discordance becomes apparent usually in the second trimester. We report a case of discordant twins diagnosed in the 10th week of gestation, which was concluded to be a case of superfecundation. The discordancy was persistent up to the 35th week of gestation, when 2 baby boys were born by cesarean section because of preeclampsia. The postnatal courses of the babies were uneventful.

Adult↗
PubMed1992

Immunohistochemical study of basement membrane reconstruction by an epidermis-dermis recombination experiment using cultured chick embryonic skin: induction of tenascin.

The production of extracellular matrix components such as laminin, Type IV collagen, fibronectin, and tenascin during the formation of basement membrane in cultured epidermis-dermis recombinant skin of 13-day-old chick embryo was analyzed immunohistochemically. The epidermis and dermis were separated from each other by treatment with EDTA and/or dispase. The basal lamina of the basement membrane was thus removed from both epidermis and dermis. The isolated epidermis was overlaid onto the isolated dermis, i.e., recombined, and then cultured for 1-7 days in a chemically defined medium (BGJb) on a Millipore filter. Immunofluorescence labeling was used for light microscopy and HRP or colloidal gold labeling for electron microscopy. In specimens from 2-day cultures, positive sites of anti-laminin and anti-fibronectin reaction were observed light microscopically as patches which, at the electron microscopic level, corresponded to fragments of the basal lamina located immediately beneath and in the vicinity of the attachment plaques of the hemidesmosomes. The staining pattern became continuous 7 days after recombination. Fluorescence labeling of laminin and fibronectin appeared somewhat earlier than that of Type IV collagen and tenascin. All of the four components were found localized primarily in the basal lamina. Furthermore, fibronectin and tenascin were also distributed in the extracellular matrix of the dermis. The expression of tenascin, which does not exist in the basement membrane of 13-day-old intact embryonic skin, was induced in vitro. These results suggest that hemidesmosomes may play an important role in the reconstruction of the basement membrane and that various components of the basement membrane appeared at different times during the reconstruction.

Animals↗
PubMed1992

Modulation of mouse placental lactogen-I secretion in vitro: effects of progesterone and mouse placental lactogen-II.

The primary objective of this study was to develop a cell culture system for assessing effects of putative secretagogues on mouse PL-I (mPL-I) secretion. Trophoblast from days 7 to 11 of pregnancy was dispersed in collagenase, and the cells were fractionated on a Percoll gradient and plated on collagen gels in serum-free medium. Cells from days 7-9 of pregnancy yielded five bands on Percoll gradients and those from days 10 and 11 yielded six. mPL-I was present in four of the bands of cells from each day of pregnancy. Cells from day 7 of pregnancy that banded at a density of 1.044 g/ml secreted the largest amount of mPL-I during 5 days of culture. The mPL-I concentration of the medium of these cells increased for the first 3 or 4 days of culture and then declined on the fifth day. mPL-II could not be detected in the medium until the third or fourth day of culture, and its concentration increased thereafter. Cell viability was about 90% at the time of plating, remained at about 80% between days 1 and 4, and then declined on day 5. The cell type that produced mPL-I was identified with the reverse hemolytic plaque assay and by staining with anti-mPL-I antiserum. Both methods indicated that mPL-I was produced by giant cells. The ability of the cells to respond to putative secretagogues was examined using mPL-II and progesterone. mPL-II, at concentrations ranging between 10 ng/ml and 10 micrograms/ml, had no effect on the mPL-I concentration of the medium when it was present for up to 3 days of culture, which suggests that mPL-II does not inhibit mPL-I secretion in vitro. Incubation of the cells in the presence of 100-1000 ng/ml progesterone caused a dose- and time-dependent reduction in the mPL-I concentration of the medium and a decrease in the number of cells that stained with anti-mPL-I antiserum. The effect of progesterone on both endpoints was not apparent until the second day of treatment. These data suggest that progesterone inhibits mPL-I secretion at least in part by inhibiting the differentiation of mPL-I-producing giant cells. The fact that the mPL-I-producing cells responded to progesterone indicates that this culture system will be useful in assessing effects of putative secretagogues on mPL-I secretion.

Animals↗
PubMed1992

Production of mouse placental lactogen-I and placental lactogen-II by the same giant cell.

In previous studies, mouse placental lactogen I (mPL-I) and mPL-II were localized to trophoblast giant cells in the placenta at midpregnancy. The present study was undertaken to determine whether mPL-I and mPL-II are produced by two distinct populations of giant cells or by the same cells. A heterogeneous population of cells that included trophoblast giant cells was obtained by enzymatic dispersion and Percoll gradient centrifugation of placentas from days 7 and 9 of pregnancy. Cells from day 7 of pregnancy were cultured in serum-free medium for 5 days, and cells that contained mPL-I, mPL-II, or both mPL-I and mPL-II were identified by double-staining immunocytochemistry. The percentage of PL cells that contained both mPL-I and mPL-II increased from about 30% on the first day of culture to about 90% on the third, and then declined to zero by day 5. Between 50% and 60% of the PL cells contained only mPL-I on the first 2 days of culture, and then the percentage of PL cells containing only mPL-I declined. The percentage of cells that contained only mPL-II was low for 3 days (<10%) and then increased to about 80% of the PL-containing cells by day 5. Cells from day 9 of pregnancy were analyzed for the release of mPL-I and/or mPL-II by sequential reverse hemolytic plaque assay. Cells that released only one of the PLs, as well as those that released both PLs, were identified. A shift was present in the type of PL released by the cells when they were followed for two consecutive days of culture. On day 1, most of the plaque-forming cells released only mPL-I, but by day 2, the fraction of plaque-forming cells that released only mPL-I declined whereas the fraction that released only mPL-II increased. Cells that released only mPL-I on the first day of culture and both mPL-I and mPL-II or only mPL-II on the second day of culture were observed. These data suggest that under these culture conditions, PL cells follow a pathway in which they initially produce only mPL-I, then both mPL-I and mPL-II, and finally only mPL-II. In vivo, there is a shift at midpregnancy in the type of PL that is produced by the mouse placenta, and these data suggest that this shift results, at least partly, from a change in gene expression in one population of giant cells.

Animals↗