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Y Eguchi

Publications and source records attributed to Y Eguchi.

At least 19 recordsLinked to original sources
PubMed1992

Isolation and characterization of the chicken bcl-2 gene: expression in a variety of tissues including lymphoid and neuronal organs in adult and embryo.

The expression of human bcl-2 gene is de-regulated by t(14;18) translocation in most of follicular lymphoma. Recent studies indicated that the bcl-2 gene product has an ability to block apoptosis of hematopoietic cells. To facilitate the analysis of the role of this gene in normal development using an animal model, we have isolated and partially characterized the chicken homologue of human bcl-2 gene. The analysis of nucleotide sequence showed that the organization of the chicken bcl-2 gene is very similar to that of human bcl-2 gene. The primary transcript is spliced to encode a 25,687 dalton (233 a.a.) protein. The chicken Bcl-2 protein has two regions highly homologous to human Bcl-2 protein surrounding a totally non-homologous region. The expression of the chicken bcl-2 gene was analyzed in various chicken tissues. In the adult chicken, bcl-2 transcripts were detected in thymus, spleen, kidney, heart, ovary and brain, with the highest levels being detected in the thymus. However, the bursa of Fabricius, which is the site of early B cell development, expressed much less amounts of bcl-2 RNA. On the other hand, in embryo, the gene is extensively expressed in the bursa, as well as in muscle and the above tissues. Our findings indicate that a homologue of the human bcl-2 gene does exist in the chicken and that its expression is developmentally regulated in some tissues.

Amino Acid Sequence↗
PubMed1992

Strong association of insulin autoimmune syndrome with HLA-DR4.

Insulin autoimmune syndrome is characterised by spontaneous hypoglycaemia without evidence of exogenous insulin administration, a high serum concentration of total immunoreactive insulin, and the presence of insulin autoantibodies in high titre. HLA typing of 27 patients with insulin autoimmune syndrome showed that all had DR4, which was present in only 43% of 51 healthy controls (odds ratio 72.1, p less than 2 x 10(-6), and 19 (70%) of the patients were positive for the allelic combination, Cw4, Bw62, and DR4. Analysis of the nucleotide sequences of the DRB1, DQA1, and DQB1 genes showed that all the patients had DRB1*0406, DQA1*0301, and DQB1*0302, compared with only 14% of the controls (odds ratio 281, p less than 1 x 10(-10). We conclude that the development of insulin autoimmune syndrome is associated with a strong genetic predisposition.

Adult↗
PubMed1992

Human insulin-specific immunoglobulin G antibody and hypoglycemic attacks after the injection of gold thioglucose.

A 56-year-old woman with granulomas of gold thioglucose in her hips exhibited recurrent bouts of hypoglycemic attacks. The first attack occurred 2 years after the last injection of gold thioglucose, when large amounts of extractable insulin and human insulin-specific antibody were noted in her serum. Histological examination of the resected granulomas showed marked infiltration of lymphocytes, plasma cells, and macrophages containing yellowish-brown granules, which proved to be gold by electron microscopy using X-ray microanalysis. After resection of the granuloma, however, the frequency of the hypoglycemic attacks decreased remarkably as well as the levels of both extractable insulin and human insulin-specific antibody.

Antibody Specificity↗
PubMed1992

Nonresponsiveness of the thyroid gland to goitrogen in the early neonatal period in the rat: light- and electron-microscopic observations.

The thyroid response of fetal and neonatal rats to propylthiouracil (PTU) as a goitrogen was studied with observation of the thyroid glands by light and electron microscopy. On day 19 of gestation and on days 1, 3, 5 and 8 after birth, fetal and neonatal rats were given a subcutaneous injection of PTU and were autopsied 2 days later. PTU induced conspicuous goiters in fetal rats but did not in neonatal rats aged up to day 5 after birth. Beyond that age, PTU again induced goiters. Histologically, the follicular cell height in goitrous thyroid glands was significantly increased. Ultrastructurally, follicular cells in goitrous thyroid glands often had colloid droplets and lysosomes. It seems that nonresponsiveness of the thyroid glands in early neonatal rats to goitrogen is due to a temporary decline of the pituitary activity of thyrotropin secretion. About 5 days or more after birth, the pituitary-thyroid system begins to operate again in response to goitrogen.

Aging↗
PubMed1992

Sensitivity of the fetal rat pituitary-adrenal system to corticotropin-releasing factor in organ culture.

Six groups of adrenal glands from 17-day fetal rats were explanted to organ culture for 2 days. In one group, adrenal gland was cultured alone, and in the remaining five groups adrenal gland was cultured with pituitaries from fetuses ranging in age from 14 to 18 days. In each of the groups, half of the cultures had corticotropin-releasing factor (CRF) added to the medium. A histometric parameter utilized the size of adrenocortical cells as an indicator of sensitivity of the pituitary-adrenal system. When 17-day adrenal gland was cultured alone, addition of CRF did not cause any enlargement of cortical cells. When the adrenal gland was cultured with two 14-day pituitaries, cortical cells were enlarged. Addition of CRF to this culture induced no further change. With two 15-day pituitaries in the presence of CRF, cortical cells were slightly larger than those in the absence of CRF. With 16- to 18-day pituitaries, a marked hypertrophy of cortical cells was induced, and the addition of CRF caused further acceleration in their enlargement. These results suggest that, in organ culture, 14-day pituitary can release some adrenocorticotropic hormone (ACTH) with or without additional CRF. Older pituitaries (16- to 18-day) can apparently release an amount of ACTH in the presence of CRF that is greater than their own spontaneous ACTH secretion.

Adrenal Glands↗
PubMed1992

Studies on closure of the ductus arteriosus in perinatal rats.

Measurements of the inner diameters (calibers) of the ductus arteriosus (DA) and pulmonary artery (PA) were made in late fetal rats and newborn rats, the latter being obtained by spontaneous or caesarean delivery. The fetal and newborn pups were frozen instantly with an acetone-dry ice mixture. The chests of these whole-body frozen pups were shaved with a surgical knife gradually from the back toward the ventral side to expose the DA and PA for measurements of their calibers. As a result, it was revealed that the DA was almost closed 180 min after birth, but that the closure and shrinkage of the DA were accelerated to some extent by caesarean delivery. On the other hand, there was no remarkable change in the PA throughout the postnatal period observed, regardless of the type of delivery, spontaneous or caesarean.

Animals↗
PubMed1991

Detection of vitronectin mRNA in tissues and cells of the mouse.

Mouse vitronectin (Vn) was isolated from serum by heparin affinity chromatography. The purified protein (Mr 71,000) supported adhesion of mouse and human cells in an Arg-Gly-Asp-dependent manner and bound to type 1 plasminogen activator inhibitor with kinetics similar to those observed using human and bovine Vn. To further characterize murine Vn and its biosynthesis in vivo, a mouse Vn cDNA was isolated from a liver cDNA library. The amino acid sequence of mouse Vn was deduced from the cDNA and was aligned with that of human Vn. Based on this alignment, mouse Vn was inferred to be 457 amino acids long and to have extensive (82%) homology with human Vn. Northern blot hybridization analysis of RNA from mouse tissues, using the mouse Vn cDNA as a hybridization probe, revealed the presence of a single transcript of 1.7 kilobases in mouse liver. Vn mRNA was not detectable in heart, lung, kidney, spleen, muscle, brain, thymus, testes, uterus, skin, adipose tissue, and aorta. The cellular localization of liver Vn mRNA was studied by in situ hybridization. Strong staining was observed only in hepatocytes, suggesting that these cells are the primary source of Vn in vivo.

Amino Acid Sequence↗
PubMed1991

Complexes formed by complementary RNA stem-loops. Their formations, structures and interaction with ColE1 Rom protein.

Regulation of replication of plasmid ColE1 involves interaction of two plasmid-specified RNA transcripts. One of these RNAs (RNA II) serves as a primer for DNA synthesis, and the other (RNA I) is complementary to part of RNA II. The complementary regions of RNA I and RNA II form several stem-loop structures. Binding of these RNAs that regulates DNA replication begins by interaction at the loop regions. Plasmid-coded Rom protein stabilizes the product of the interaction. In this paper, the mechanism of the loop-to-loop interaction between pairs of RNA stem-loops having various nucleotide sequences is studied. Binding of two stem-loops containing six to eight nucleotides in their loops requires that the loop sequences be complementary, whereas the stem sequences need not be. The association rate constants for binding of complementary pairs with various sequences are relatively similar, around 1 x 10(6) M-1 S-1. On the other hand, the rates of dissociation of the complexes vary greatly depending on the loop sequence, even for complexes having the same base composition, suggesting a strong effect of base-stacking. All the complementary bases in the seven-nucleotide loops participate in complex formation, and the resulting complex is bent a little at the interacting region. Rom binds and stabilizes any complex formed by pairs containing fully complementary loop sequences. Structures are proposed for the RNA complexes with and without Rom.

Bacterial Proteins↗
PubMed1991

Hepatic disposition characteristics of 111In-labeled lactosaminated bovine serum albumin in rats.

The hepatic disposition of lactosaminated bovine serum albumin (Lac-BSA) in rats was studied at the whole body, isolated liver, and isolated parenchymal cell levels. After intravenous injection, 111In-Lac-BSA (1 mg/kg) was rapidly eliminated from the plasma due to extensive uptake by liver parenchymal cells; however, a significant decrease in hepatic clearance was observed at high dose (50 mg/kg). In a single-pass, constant infusion experiment in the isolated liver, 111In-Lac-BSA was continuously extracted. The extraction ratio at steady state (Ess) for 111In-Lac-BSA was significantly decreased by coadministrating galactose, NH4Cl, or chloroquine, and at low temperature, suggesting that hepatic uptake of Lac-BSA proceeds via receptor-mediated endocytosis for asialoglycoprotein. Kinetic analysis of 111In-Lac-BSA binding with isolated parenchymal cells at 4 degrees C yielded a dissociation constant (Kd) of 2.5 x 10(-8) M and a value of 3.5 x 10(5) maximal binding sites/cell (Bmax). The internalization rate constant (kint) for 111In-Lac-BSA was calculated to be 0.46 min-1 in liver perfusion experiments using the EDTA-wash method.

Animals↗
PubMed1991

Antisense RNA.

Explore the source record for details and available documents.

Base Sequence↗
PubMed1991

Onset of the constrictive effect of indomethacin on the ductus arteriosus in fetal rats.

The time of onset of the constrictive effect of indomethacin on the ductus arteriosus (DA) in fetal rats was assessed by measurement of the caliber of the DA after maternal treatment with indomethacin on days 19-21 of gestation. The day following overnight mating was regarded as day 0 of gestation. Observation was performed by direct exposure of the DA by hand shaving of intact frozen fetuses. On days 20 and 21, the DA was significantly constricted 3 h after maternal treatment with 1 mg/kg of indomethacin. When the DA was examined at 19 1/2 and 19 2/3 days of gestation (3 h after indomethacin exposure), it was significantly constricted at 19 2/3 days but not at 19 1/2 days. Higher doses of indomethacin (10 and 100 mg/kg) induced a significant constriction of the DA at day 19 1/2, but not at the beginning of the same day (1.00 a.m.). These results suggest that the onset of the susceptibility of the DA to the constrictive effect of indomethacin occurs in the first half of day 19 of gestation.

Animals↗
PubMed1991

Mild hypothermia ameliorates ubiquitin synthesis and prevents delayed neuronal death in the gerbil hippocampus.

BACKGROUND AND PURPOSE: The purpose of the present study is to determine the effect of mild hypothermia on the synthesis of ubiquitin, an important protein for maintenance of cell viability, in the hippocampal neurons following transient cerebral ischemia. METHODS: Transient ischemia was induced by occluding both common carotid arteries for 5 minutes. In experiment 1, the animals were divided into four groups according to the rectal and scalp temperatures during ischemia: the normothermia group and the graded hypothermia A, B, and C groups (n = 9 per group). CA1 neuronal density was assessed at 7 days after ischemia. In experiment 2, the animals were divided into two groups designated the normothermia and the hypothermia groups (n = 6 per group). The presence of ubiquitin was examined by immunohistochemistry at 6, 24, and 48 hours after transient ischemia in various regions of the hippocampus. RESULTS: In experiment 1, the mean +/- SEM neuronal density per millimeter was 12 +/- 1 in the normothermia group and 126 +/- 25, 225 +/- 10, and 214 +/- 9 in hypothermia groups A, B, and C, respectively. Mild hypothermia in groups B and C, in which the brain temperature was below 33 degrees C, ameliorated markedly the extent of ischemic neuronal damage in the CA1 sector (p less than 0.01). In experiment 2, ubiquitin immunoreactivity had disappeared in all regions of the hippocampus at 6 hours after ischemia and showed no subsequent recovery in the CA1 pyramidal neurons under normothermic conditions. Under hypothermic conditions, however, it had recovered significantly in the CA1 pyramidal neurons at 24 and 48 hours after ischemia (p less than 0.01). CONCLUSIONS: We conclude that mild hypothermia, in which the brain temperature is below 33 degrees C, markedly improves the ischemic delayed neuronal damage in the CA1 sector, and that increased ubiquitin synthesis and protein ubiquitination could be one essential part of the protective mechanism afforded by mild hypothermia against delayed neuronal death.

Animals↗
PubMed1991

Studies on hypotensive agents. Synthesis of 1-substituted 3-(2-chlorophenyl)-6-ethoxycarbonyl-5,7-dimethyl-2,4(1H,3H)-quinazoline diones.

3-(2-Chlorophenyl)-6-ethoxycarbonyl-5,7-dimethyl-2,4(1H,3H)-quinazoline dione was newly prepared. 1-Hydrogen atoms of the compound were variously substituted in order to test for their hypotensive activities on relaxing effects of the blood vessels. The compounds with 2-(1-pyrrolidinyl) ethyl, 2-(1-piperidinyl)ethyl, 3-(dimethylamino)propyl, and 3-(N-benzyl-N-methylamino)propyl moieties showed significant activity. The 2-(1-piperidinyl)ethyl compound possessed activity approximately 23 times more potent than papaverine, however, it was less potent than cinnarizine.

Animals↗
PubMed1991

Studies on antiatherosclerotic agents. Synthesis of 5-substituted derivatives of 7-ethoxycarbonyl-6,8-dimethyl-1(2H)-phthalazinone.off.

Several 5-substituted derivatives of 7-ethoxycarbonyl-6,8-dimethyl-1(2H)- phthalazinone were prepared by means of nitration, reductive amination, and diazonium decomposition. The substituents introduced included NO2, NH2, F, Cl, CN. Among the derivatives, the fluorine compound was obtained only in poor yield because intramolecular cyclization occurred predominantly.

Arteriosclerosis↗
PubMed1991

Studies on antiatherosclerotic agents. Synthesis of 7-ethoxycarbonyl-4-formyl-6,8-dimethyl-1(2H)-phthalazinone derivatives and related compounds.

Derivatives of 7-ethoxycarbonyl-4-formyl-6,8-dimethyl-1(2H)-phthalazinone and closely related compounds were synthesized using Wittig and epoxidation reactions. Ring opening amination of the epoxides were carried out using dimethylaluminum amide reagents under mild reaction conditions. beta-Keto ester and beta-diketone moieties were introduced through diazo derivatives. These moieties were reacted with hydrazine hydrate to produce 4-pyrazolyl derivatives. The derivatives were tested for their inhibitory effect on platelet aggregation, and their relaxing effect on blood vessels.

Animals↗