Biomedical subjects

Y Horio

Publications and source records attributed to Y Horio.

At least 73 records · Page 4Linked to original sources

PubMed1994

Characterization of an 800 kb region at 3p22-p21.3 that was homozygously deleted in a lung cancer cell line.

We have characterized a homozygous deletion at 3p22-p21.3 found in a lung cancer cell line ACC-LC-5. Three yeast artificial chromosomes (YACs) were isolated from a YAC library by hybridization with two cosmid probes (cCI3-1994 and cCI3-1999) representing loci that were homozygously deleted in five lung cancer cell lines. Cloning both ends of the region deleted in the cell line ACC-LC-5 revealed the deletion was an interstitial deletion within the chromosomal arm. A cosmid contig map covering the entire region corresponding to the homozygous deletion was constructed by means of Southern hybridizations. From these results and analyses by pulsed-field gel electrophoresis, this interstitial deletion on chromosome 3p22-21.3 in this cell line was estimated to be nearly 800 kb long and is smallest among five cell lines containing the homozygous deletion. The cosmid clones representing this region will contribute important new resources for isolating the putative tumor suppressor gene(s) on chromosome 3p22-21.3.

Base Sequence↗

PubMed1994

Expression and characterization of the bovine histamine H1 receptor in cDNA-transfected C6 astroglioma cells.

Rat C6 astroglioma cells (C6-bH1R cells) expressing cloned bovine histamine H1 receptors were established by transfection with a vector (pEF-BOS-bH1R) which carried a 2.7-kbp EcoRI fragment of the bovine H1 receptor cDNA [Yamashita, M. et al. (1991) Proc. Natl. Acad. Sci. USA 88, 11515-11519]. The cloned bovine H1 receptor in C6-bH1R cells was characterized by three established criteria: the [3H]mepyramine binding assay, the accumulation of inositol phosphates induced by histamine, and histamine-induced elevation of intracellular Ca2+ concentration ([Ca2+]i). The accumulation of inositol phosphates induced by histamine was time- and dose-dependent. The accumulation of inositol trisphosphate was biphasic with a prompt increase to the maximal level, followed by a sustained submaximal level. The histamine-induced accumulation of inositol phosphates was suppressed by phorbol ester, but not by pertussis toxin. Results from the [3H]-mepyramine binding assay and histamine-induced elevation of [Ca2+]i were characteristic of H1 receptors. Several compounds among tricyclic antidepressants, neuroleptics, and serotonin antagonists showed affinities to the cloned bovine H1 receptor with Ki values similar to reported values. Histamine neither induced cAMP accumulation nor attenuated forskolin-induced cAMP accumulation in C6-bH1R cells. C6-bH1R cells are particularly useful for studying the H1 receptor-mediated astroglial cell functions.

Animals↗

PubMed1994

Does the [3H]mepyramine binding site represent the histamine H1 receptor? Re-examination of the histamine H1 receptor with quinine.

Mepyramine is a potent H1 receptor antagonist, and [3H]mepyramine generally is used to label histamine H1 receptors. However, we found that [3H]mepyramine labeled not only the H1 receptor but also a [3H]mepyramine binding protein (MBP) in the liver, which protein appears to be related to the subfamily of debrisoquine 4-hydroxylase (cytochrome P450IID) isozymes. The binding of [3H]mepyramine to the cloned H1 receptor was not affected by 1 microM quinine, an inhibitor of debrisoquine 4-hydroxylase. On the other hand, the binding to MBP in the liver membranes was completely inhibited by 1 microM quinine. These data indicate that the labeling by [3H]mepyramine of H1 receptors and MBP can be completely separated with 1 microM quinine. The majority of [3H] mepyramine binding sites in the cerebral cortex, thalamus and hypothalamus, hippocampus, heart, aorta, lung and spleen were H1 receptors. On the other hand, almost all [3H]mepyramine binding sites in the liver and kidney were MBP. Both H1 receptors and MBP were expressed in the stomach, ileum, cerebellum and adrenal gland. Kd values of [3H]mepyramine for membranes from the cerebellum and stomach in the presence of quinine, which tissues contain both H1 receptors and MBP, approached that value of the cloned H1 receptor. The improved [3H]mepyramine binding assay using quinine is a precise method to characterize H1 receptors by the separate determination of H1 receptors and MBP.

Animals↗

PubMed1994

Predominantly tumor-limited expression of a mutant allele in a Japanese family carrying a germline p53 mutation.

Germline mutations of p53 have been implicated as a cause of cancer susceptibility in the Li-Fraumeni syndrome. Since inactivation of p53 has been suggested to play an important causative role in lung cancer, the present study of the prevalence of germline mutations in 148 patients with this neoplasm was performed. None of 138 randomly chosen patients were found to carry such mutations, while a single patient had a nonsense mutation at codon 213 among 10 patients selected for early onset and/or occurrence of multiple primary cancers. In contrast to the previous report of biallelic expression of p53 in a case with a germline missense mutation, preferential expression of the wild-type allele was observed in the heterozygous state in both normal lung and peripheral blood lymphocytes of our case, whereas expression of mutant mRNA was readily detectable in her lung cancer in the absence of the remaining wild-type allele. Interestingly, the family history of the proband showed a mild aggregation of adulthood cancers and a high prevalence of stomach cancer, a rare component in American families affected by the syndrome. These observations suggest the presence of heterogeneity with regard to molecular and clinical features of germline p53 mutations.

Adult↗

PubMed1994

Aberrant upregulation of a novel integrin alpha subunit gene at 3p21.3 in small cell lung cancer.

Our recent identification of homozygous deletions at 3p21.3 in lung cancer has provided further support for the presence of a tumor suppressor gene in this chromosomal region. As a part of our efforts for positional cloning of a tumor suppressor gene at 3p21.3, we have characterized a transcriptional unit within this region using genomic fragments with interspecies conservation. The identified gene was found to encode a novel integrin alpha subunit, termed alpha RLC, which is closely related to alpha 4 in structure but clearly different from alpha 4 in its expression pattern in the physiological and pathological setting of the lung. This finding and the exact localization of the gene suggest that it is a good candidate for a tumor suppressor gene in lung cancer, but our extensive search covering one third of the gene did not reveal any somatic mutations within the coding region. Interestingly, however, alpha RLC was abundantly expressed in fetal lung and lung cancers, particularly small cell lung cancers (SCLC). Its aberrant upregulation in the SCLC samples, both cell lines and primary tumors, which might have been caused by a yet unidentified mutations or by deletions of other gene, and its homology to alpha 4, which is thought to play a role in metastasis, suggest that altered alpha RLC expression may contribute to the acquisition of malignant phenotypes of this type of lung cancer.

Amino Acid Sequence↗

PubMed1993

Genomic cloning of the rat histamine H1 receptor.

A rat histamine H1 receptor gene which lacked introns was isolated from a rat genomic library using recently cloned bovine histamine H1 receptor cDNA [Yamashita et al., Proc. Natl. Acad. Sci. USA, 88, 11515-11519 (1991)]. The receptor protein deduced from this isolated gene was composed of 486 amino acids and showed characteristic properties of G protein-coupled receptors. At the 5'-flanking region of the receptor gene, we have located potential TATA box sequences and consensus sequences for the glucocorticoid response element and AP-2 element. After being subcloned into a mammalian expression vector, the isolated gene was transfected to C6 glioma cells. These cells showed significant binding toward [3H]mepyramine. The binding was inhibited by H1 antagonists or histamine. The mode of this binding was comparable to the binding of membranes derived from rat tissues toward [3H]mepyramine. Northern blot analysis detected a 3.0 kb nucleotide band for histamine H1 receptor mRNAs from rat brain and small intestine when these mRNAs were hybridized with the isolated rat H1 gene. The present results demonstrate the isolation of the rat histamine H1 receptor gene.

Amino Acid Sequence↗

PubMed1993

Prognostic significance of p53 mutations and 3p deletions in primary resected non-small cell lung cancer.

We evaluated the prognostic significance of p53 mutations and an allelic loss of chromosome 3p in 71 patients with non-small cell lung cancer who underwent potentially curative resection. p53 mutations were detected in 35 cases (49%), while 3p deletions were observed in 34 of 70 informative cases (49%). The presence of the p53 mutation was associated with a shortened survival in all patients (P = 0.014 by log rank test), including those in early stages of the disease (stage I or II, n = 48) (P = 0.016 by log rank test). Multivariate analysis by the Cox proportional hazards model also revealed that p53 mutation was an independent yet unfavorable prognostic factor (P = 0.013). Patients with 3p deletion tended to have a poorer prognosis, but not to a statistically significant extent.

Aged↗

PubMed1993

Molecular cloning of the guinea-pig histamine H1 receptor gene.

The histamine H1 receptor gene was isolated from a guinea-pig gene library. The gene contains no introns and encodes a protein of 488 amino acid residues. The structure of the guinea-pig histamine H1 receptor is predicted to contain seven putative transmembrane regions, which are similar to those of receptors coupling with GTP binding proteins. Although the third intracellular domain, the predicted binding site for the GTP binding protein, showed only 50% identity with those of the bovine and rat H1 receptors, the expressed guinea-pig H1 receptor was fully able to bind with [3H]mepyramine. Northern blot analysis indicated that the cerebrum, cerebellum, lung, adrenal, intestine, and heart expressed 3.3 kb guinea-pig H1 receptor mRNA. Expression of histamine H1 mRNA of guinea-pig peripheral organs was greater than that of rat organs, suggesting the high sensitivity of guinea-pig organs as to histamine is due to the contents of histamine H1 receptor mRNA. In addition, the lung, adrenal, intestine, and heart expressed 3.9 kb mRNA. In situ hybridization showed that the hippocampus, cerebral cortex, thalamus, and granular layer of the cerebellum each contained a large amount of histamine H1 receptors. Southern blot analysis showed that there was another gene quite similar to the cloned histamine H1 receptor gene.

Amino Acid Sequence↗

PubMed1993

Frequent homozygous deletions in lung cancer cell lines detected by a DNA marker located at 3p21.3-p22.

Frequent allelic losses of chromosome 3p in lung cancer have been reported in a number of studies, and we previously demonstrated that 3p21.3 is one of the common regions of deletion in lung cancers and renal cell carcinomas. To further define a region containing the putative tumor suppressor gene, we performed Southern-blot analysis of 26 small cell lung cancer (SCLC) cell lines and ten non-small cell lung cancer (NSCLC) cell lines with 40 cosmid markers located at 3p21.3-p22. One marker detected homozygous deletions of four SCLC cell lines and one NSCLC cell line. None of the other markers revealed homozygous deletions or chromosomal rearrangements in these cell lines. The region of homozygous deletion described here is estimated to consist of less than 1 megabase of DNA, and it is very likely to contain at least one of the tumor suppressor genes associated with carcinogenesis of lung cancer and, possibly, renal cell carcinoma.

Alleles↗

PubMed1993

The effect of nutrition on the size and proportion of muscle fibre types during growth.

To investigate whether the retardation in the increase of body weight produced by reduced food intake could influence the transformation of muscle fibre types in soleus and extensor digitorum longus (EDL) during growth, rats were divided into 3 groups at 3 wk of age. Each group was subjected to food restriction from 3 wk of age to the following ages. Group 1 comprised 5 (148.7 +/- 7.3 g), 7 (250.7 +/- 11.1 g), 9 (362.9 +/- 19.3 g) and 11-wk-old rats (414.9 +/- 35.2 g) fed ad libitum. Group 2 comprised 5 (148.7 +/- 7.3 g), 7 (148.6 +/- 7.7 g), 9 (147.7 +/- 6.0 g) and 11-wk-old rats (148.8 +/- 5.7 g) fed a restricted diet; these animals were similar in weight to the 5-wk-old rats in group 1. Group 3 comprised 4 subgroups of 11-wk-old rats (148.7 +/- 5.7 g, 247.6 +/- 6.8 g, 354.4 +/- 8.6 g, 414.4 +/- 35.2 g); their body weights were adjusted to the weights of 5, 7, 9 and 11-wk-old rats in group 1 by restriction of food intake. Muscle weights and fibre areas in soleus and EDL significantly increased with growth. The muscle weights and fibre areas in group 2 in which body weights were equal increased significantly with age, but the increases were significantly less than for group 1. The muscle weights and fibre areas in group 3 in which ages were equal increased significantly with increasing body weight; the increases were the same as those in group 1.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗

PubMed1992

Re-examination of [3H]mepyramine binding assay for histamine H1 receptor using quinine.

[3H]Mepyramine, a potent antagonist of the histamine H1 receptor, has been widely used as a radioligand binding assay for the H1 receptor. Previously, we purified a mepyramine binding protein (MBP) from rat liver, but found that its partial amino acid sequences were very similar to those of debrisoquine 4-hydroxylase isozymes (P450 db1 and db2), which are members of the superfamily of cytochrome P450. Using cloned histamine H1 receptor cDNA, we found that [3H]mepyramine could bind only the H1 receptor and did not bind MBP in the presence of 10(-5) M quinine, an inhibitor of debrisoquine 4-hydroxylase isozymes. We developed a method to determine the contents of the H1 receptor and MBP separately using [3H]mepyramine and quinine and found that MBP is abundant in certain areas of bovine brain.

Animals↗

PubMed1992

Small caliber catheter drainage for spontaneous pneumothorax.

Excellent results have been reported after small caliber catheters were used for iatrogenic pneumothoraces. However, the value of using such catheters for spontaneous pneumothoraces is not clear. The purpose of this study, therefore, is to examine the efficacy of small caliber catheters in managing spontaneous pneumothoraces. Seventy six episodes of spontaneous pneumothorax were treated using a small caliber catheter (No. 5.5 or 7.0 French) connected to a Heimlich valve. All catheters were inserted by physicians. The treatment was considered successful when there was no air leakage and little or no residual pneumothorax. Before the lungs were fully expanded, four patients had died and one had refused to comply with further treatment. The remaining 71 episodes of pneumothoraces were evaluated for efficacy. The treatment was successful in 60 patients (84.5%) and ineffective in the remaining 11. The conventional large caliber tube was inserted in 10 of the 11 failures, but they were successful in only six. No major complications resulting from catheter insertion occurred, and no catheters became occluded. The catheter was easy to insert, and the scar that remained after removal of the catheter was very small. Not only are small caliber catheters effective for managing spontaneous pneumothoraces, they are the initial treatment of choice.

Catheterization↗

PubMed1991

Expression cloning of a cDNA encoding the bovine histamine H1 receptor.

A functional cDNA clone for the histamine H1 receptor was isolated from a cDNA library of bovine adrenal medulla by a combination of molecular cloning in an expression vector and electrophysiological assay in Xenopus oocytes. The H1 receptor cDNA encodes a protein of 491 amino acids (Mr 55,954) with seven putative transmembrane domains, illustrating the similarity to other receptors that couple with guanine nucleotide-binding regulatory proteins (G protein-coupled receptors). The sequence homology between the H1 and H2 receptors is not higher than that between the histamine H1 and m1-muscarinic receptors. The cloned receptor protein expressed in COS-7 cells bound specifically to [3H]mepyramine, an H1 receptor antagonist, and this binding was displaced by H1 receptor antagonists and histamine with affinities comparable with those in membranes of bovine adrenal medulla. H1 receptor mRNA was shown to be expressed in brain and in peripheral tissues, including lung, small intestine, and adrenal medulla. This investigation discloses the molecular nature of the H1 receptor--a receptor that mediates diverse neuronal and peripheral actions of histamine and that may be of therapeutic importance in allergy.

Amino Acid Sequence↗

PubMed1991

Purification of guanylyl cyclase from rod outer segments.

The particulate form of guanylyl cyclase from bovine rod outer segments has been solubilized and purified to near homogeneity by a combination of liquid chromatography and native gel electrophoresis. The procedure enriches enzyme activity 6700-fold from rod outer segment extracts to a final specific activity of 17.5 mumol/min per mg (when assayed with Mn-GTP as substrate). Purified preparations of guanylyl cyclase contain a single glycoprotein with an apparent molecular mass of 60,000 Da and a native isoelectric point of 7.6. Although crude or partially purified enzyme activity is modulated by sub-micromolar concentrations of Ca2+, the fully purified enzyme is insensitive to this cation. However, the purified enzyme remains sensitive to nitrovasodilators, being stimulated over 10-fold by sodium nitroprusside. These data suggest that retinal rods contain a unique isoform of guanylyl cyclase.

Animals↗

PubMed1991

Solubilization of guanylyl cyclase from bovine rod outer segments and effects of lowering Ca2+ and nitro compounds.

Guanylyl cyclase from bovine rod outer segments was solubilized using Triton X-100 and a high concentration of KCl, and its regulation was studied. The efficiency of solubilization was about 50-90% of total activity. When the Ca2+ content was lowered (less than 80 nM), guanylyl cyclase was activated about 2-fold. In the presence of higher concentrations of Ca2+ (greater than 140 nM), the activity was decreased. The regulation by Ca2+ was also demonstrated with solubilized preparations. In the presence of 186 nM Ca2+ which inhibited guanylyl cyclase, La3+ activated the enzyme about 2-fold, suggesting that the Ca2(+)-binding protein similar to other Ca2(+)-binding proteins associates with guanylyl cyclase regulation. Sodium nitroprusside and nitric oxide which are activators of soluble guanylyl cyclase in other tissues also activated the retinal guanylyl cyclase. Maximum activation by sodium nitroprusside was 20-fold using Mg2+ as a cofactor. Activation by nitric oxide and related compounds suggests that retinal guanylyl cyclase contains a heme prosthetic group that may participate in a novel regulatory mechanism for this enzyme.

Animals↗

PubMed1991

Pharmacokinetics of an etoposide infused over three days: concomitant infusion with cisplatin.

The pharmacokinetics of a 72-hour infusion of 240 mg/m2 etoposide administered concurrently with 90 mg/m2 cisplatin was studied in 12 lung cancer patients. The area under the curve (AUC), elimination half-life, steady state concentration, systemic clearance, renal clearance of etoposide and distribution volume at steady state were 225.4 +/- 39.2 micrograms x h/ml, 8.1 +/- 3.4 h, 3.1 +/- 0.6 micrograms/ml, 18.8 +/- 3.1 ml/min/m2, 3.1 +/- 1.4 ml/min/m2, 9.6 +/- 3.8 l/m2, respectively, which were in accordance with those reported previously in patients treated with etoposide alone. Although concentration at 24 hours, total bilirubin level and total protein level were correlated with the AUC which in turn correlated with hematologic toxicity, the variables were not predictive of hematologic toxicity. We conclude that the concomitant administration of cisplatin at a dose level of 30 mg/m2/day might not affect the pharmacokinetics of prolonged etoposide infusion.

Aged↗

PubMed1990

Molecular cloning of guinea-pig aromatic-L-amino acid decarboxylase cDNA.

Guinea-pig aromatic-L-amino acid decarboxylase (DOPA decarboxylase, DDC), but not rat DDC, reacts with the antibody against rat histidine decarboxylase (HDC). For determination of the molecular reaction for this cross-reactivity, a cDNA clone of guinea-pig DDC was isolated. Guinea-pig DDC consists of 480 amino acids and its molecular weight is 54,148. The sequence identify of guinea-pig DDC with rat DDC is 86%. Guinea-pig DDC has a region showing 100% sequence identity with rat HDC, but only 67% sequence identity with rat DDC, suggesting that this region is related with the cross-reactivity of guinea-pig DDC and anti-rat HDC antibody.

Amino Acid Sequence↗

PubMed1990

Plasma membrane fatty acid-binding protein and mitochondrial glutamic-oxaloacetic transaminase of rat liver are related.

The hepatic plasma membrane fatty acid-binding protein (h-FABPPM) and the mitochondrial isoenzyme of glutamic-oxaloacetic transaminase (mGOT) of rat liver have similar amino acid compositions and identical amino acid sequences for residues 3-24. Both proteins migrate with an apparent molecular mass of 43 kDa on SDS/polyacrylamide gel electrophoresis, have a similar pattern of basic charge isomers on isoelectric focusing, are eluted similarly from four different high-performance liquid chromatographic columns, have absorption maxima at 435 nm under acid conditions and 354 nm at pH 8.3, and bind oleate with a Ka approximately 1.2-1.4 x 10(7) M-1. Sinusoidally enriched liver plasma membranes and purified h-FABPPM have GOT enzymatic activity; the relative specific activities (units/mg) of the membranes and purified protein suggest that h-FABPPM constitutes 1-2% of plasma membrane protein in the rat hepatocyte. Monospecific rabbit antiserum against h-FABPPM reacts on Western blotting with mGOT, and vice versa. Antisera against both proteins produce plasma membrane immunofluorescence in rat hepatocytes and selectively inhibit the hepatocellular uptake of [3H]oleate but not that of [35S]sulfobromophthalein or [14C]taurocholate. The inhibition of oleate uptake produced by anti-h-FABPPM can be eliminated by preincubation of the antiserum with mGOT; similarly, the plasma membrane immunofluorescence produced by either antiserum can be eliminated by preincubation with the other antigen. These data suggest that h-FABPPM and mGOT are closely related.

Amino Acid Sequence↗