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Biomedical subjects

K Okui

Publications and source records attributed to K Okui.

At least 19 recordsLinked to original sources

Structure and chromosomal assignment of the human S1-5 gene (FBNL) that is highly homologous to fibrillin.

The human S1-5 gene (fibrillin-like; FBNL) was originally isolated from a subtractively enriched cDNA library established from a subject with Werner syndrome (WS). We isolated genomic clones containing the entire S1-5 gene and determined its genomic structure including the exon-intron organization. The gene spanned approximately 18 kb of genomic DNA and consisted of 12 exons. Its expression was abundant in all tissues examined except brain and peripheral leukocytes, where it was undetectable. In addition, we have mapped S1-5 by fluorescence in situ hybridization to chromosome 2p16, a position that excludes it as a candidate for WS. Our data should facilitate an understanding of the function and regulation of S1-5 in human tissues.

Base Sequence

Cloning and mapping of a novel human cDNA homologous to DROER, the enhancer of the Drosophila melanogaster rudimentary gene.

We have isolated a novel human cDNA clone that encodes a protein with 80% identity in amino acid sequence to DROER, the enhancer of the rudimentary gene in Drosophila melanogaster. The rudimentary gene product is thought to have significant enzymatic functions in the pyrimidine metabolic pathway, as well as a critical role in development of the wings. The human cDNA, termed ERH, consists of 797 nucleotides, which include an open reading frame of 312 nucleotides encoding 104 amino acids. The ERH gene was expressed in all normal human tissues examined. We assigned the ERH gene locus to chromosomal band 7q34 by fluorescence in situ hybridization.

Amino Acid Sequence

Isolation and mapping of a novel human gene encoding a protein containing zinc-finger structures.

We have isolated and characterized a cDNA clone, termed OTK18, representing a novel human gene. The 3754 nucleotides of this clone contain an open reading frame of 2133 nucleotides. As the predicted 711-amino-acid protein contains 13 contiguous zinc-finger stuctures of the C2H2 type, it would be expected to function as a DNA-binding multi-finger protein. The 4.3-kb transcript was expressed in all adult human tissues examined by Northern analysis. The gene was assigned to chromosomal band 19q13.4 by fluorescence in situ hybridization.

Amino Acid Sequence

Isolation, characterization and chromosomal assignment of the human WNT7A gene.

The Wnt genes compose a large gene family encoding a group of secreted signaling molecules that have been implicated in oncogenesis and a number of developmental processes. We have isolated a full-length human cDNA clone that we consider to be a novel member of the Wnt gene family. The gene (WNT7A) encodes a deduced 349-amino-acid peptide with 98% identity in amino acid sequence to murine Wnt7a. Expression of this gene is restricted to certain tissues: placenta, kidney, testis, uterus, fetal lung, and fetal and adult brain. Furthermore, we have isolated a genomic clone of WNT7A and mapped it to chromosome 3p25 by fluorescent in situ hybridization.

Amino Acid Sequence

Isolation, characterization and chromosomal assignment of human colligin-2 gene (CBP2).

Colligin, a collagen-binding glycoprotein localized to endoplasmic reticulum, belongs to the serpin superfamily. Colligin has been identified and cloned in a number of species including mouse, rat, chicken, and human. We have isolated and characterized a full-length human cDNA clone that encodes a 418-amino-acid peptide that is highly homologous (97% identity) to the previously reported human colligin gene, and have named this new member of the colligin family human colligin-2. The expression of the colligin-2 gene (CBP2) is ubiquitous among all normal human tissues except for brain and peripheral leukocytes. We have mapped this novel gene to chromosomes 11q13.5 by fluorescent in situ hybridization (FISH) using a cosmid clone containing the entire coding sequence and the 3' non-coding sequence.

Amino Acid Sequence

A 3-Mb physical map of the chromosome region 8p21.3-p22, including a 600-kb region commonly deleted in human hepatocellular carcinoma, colorectal cancer, and non-small cell lung cancer.

To isolate a putative tumor suppressor gene(s), we have constructed a physical map and a detailed deletion map of chromosome region 8p21.3-p22, where loss of heterozygosity (LOH) has been frequently seen in human hepatocellular carcinomas (HCC), colorectal cancers (CRC), and non-small cell lung cancers (NSCLC). The smallest commonly deleted region at 8p21.3-p22 in HCC and CRC was between the loci defined by C18-245 and C18-2644; in NSCLC, a region between C18-1051 and C18-2644 was commonly deleted. A contiguous physical map of 12 cosmid markers in the 8p21.3-p22 region was constructed by means of multi-color fluorescence in situ hybridization (FISH) and pulsed-field gel electrophoresis (PFGE). On the basis of this physical map, which spans roughly 3.1 Mb, the estimated sizes of the commonly deleted regions were at most 1.2 Mb in HCC and CRC and 0.6 Mb in NSCLC. As four of the 12 physically ordered markers are located within the 0.6 Mb region commonly deleted in all three tumor types, nearly one fourth to one fifth of the target region has already been covered with cosmid inserts.

Animals

Isolation and mapping of 328 new cosmid markers on human chromosome 8: construction of a high-resolution cytogenetic map of chromosome 8 with 416 markers.

We have determined the chromosomal localizations of newly isolated cosmids by fluorescent in situ hybridization (FISH) on prometaphase R-banded chromosomes and have constructed a high-resolution cytogenetic map for human chromosome 8 with 416 cosmid markers, including 328 new markers and 88 reported previously. Of the 416 markers, 229 were mapped to the long arm of chromosome 8, 181 to the short arm, and 6 to the centromere. Although the clones were scattered throughout the chromosome, they were concentrated in R-positive bands. Since the estimated physical length of chromosome 8 is 135 Mb, the overall average distance between loci is 320 kb, but the average separation of loci on R-positive bands is nearly 130-200 kb. This cytogenetic map will serve as a resource for efforts to characterize chromosomal and molecular aberrations involved in cancers, to clone genes associated with hereditary diseases, and to construct a detailed physical map of large electrophoretic fragments and/or contiguous cosmids and yeast artificial chromosomes.

Animals

Refined mapping of a gene responsible for Fukuyama-type congenital muscular dystrophy: evidence for strong linkage disequilibrium.

Fukuyama-type congenital muscular dystrophy (FCMD), the second most common form of childhood muscular dystrophy in Japan, is an autosomal recessive severe muscular dystrophy associated with an anomaly of the brain. After our initial mapping of the FCMD locus to chromosome 9q31-33, we further defined the locus within a region of approximately 5 cM between loci D9S127 and CA246, by homozygosity mapping in patients born to consanguineous marriages and by recombination analyses in other families. We also found evidence for strong linkage disequilibrium between FCMD and a polymorphic microsatellite marker, mfd220, which showed no recombination and a lod score of (Z) 17.49. A "111-bp" allele for the mfd220 locus was observed in 22 (34%) of 64 FCMD chromosomes, but it was present in only 1 of 120 normal chromosomes. This allelic association with FCMD was highly significant (chi 2 = 50.7; P < .0001). Hence, we suspect that the FCMD gene could lie within a few hundred kilobases of the mfd220 locus.

Chromosome Mapping

The human prohibitin (PHB) gene family and its somatic mutations in human tumors.

Five cosmid clones, isolated by procedures to screen genomic libraries for homologous variants of the human prohibitin gene (PHB), were analyzed to determine their genomic structures. Four of these (PHBP1-4) were found to be processed pseudogenes, each located on a different chromosome from their counterparts on chromosome 17q21. The DNA sequence of one clone (PHBP1, on chromosome 6q25) shared a 91.3% identity at the nucleotide level with the cDNA of functional prohibitin. A large number of human tumors of the breast, ovary, liver, and lung were examined for somatic mutations in the PHB gene. Although mutations were observed in a few sporadic breast cancers, none were identified in any of the other cancers.

Base Sequence

A novel anticancer treatment for xenoplanted human gastric cancer using polyamine antimetabolites in a low polyamine diet.

The aim of the present study was to evaluate a new anticancer treatment for gastrointestinal cancer, using a combination of polyamine antimetabolites, an anticancer agent and a low-polyamine state. Two polyamine antimetabolites, given as either 40 mg/kg of methylglyoxal-bis-guanylhydrazone (MGBG) or ethylglyoxal-bis-guanylhydrazone (EGBG) and a normal diet (ND), or 20 mg/kg of each drug and a low polyamine diet (LPD), together with 1,000 mg/kg of alphadifluoromethylornithine (DFMO) were administered ip to nude mice for six consecutive days. Mitomycin C (MMC) at 2 mg/kg was then given ip for 3 alternate days. The combination of MGBG or EGBG with DFMO plus MMC resulted in an enhanced antitumor efficacy on LPD. However, the combination which included EGBG was much more enhanced than that which included MGBG and there was no evidence of any tumor regrowth. Weight loss was minimal or nil in the mice given the combination with EGBG, but was evident in those given the combination with MGBG. These results led to the conclusion that in mice, the combined therapy of EGBG with DFMO plus MMC and LPD is a safe and effective regimen for the treatment of gastric cancer.

Adenosylmethionine Decarboxylase

Isolation and mapping of 88 new RFLP markers on human chromosome 8.

To obtain new RFLP markers for construction of a high-resolution map of human chromosome 8, a cosmid library was constructed from a somatic hybrid cell that contained chromosome 8 as the only human component in mouse genomic background. Eighty-eight new RFLP markers were isolated and characterized, and 71 of them were sublocalized to chromosomal bands by fluorescent in situ hybridization (FISH). Of these, 36 were localized to the short arm, 34 to the long arm, and 1 to the centromeric region. Five markers defined VNTR loci. This work represents the first extensive isolation and physical mapping of RFLP markers on human chromosome 8. These new markers will serve as useful resources for linkage mapping of loci for inherited diseases and for efforts to identify a putative tumor suppressor gene(s) on chromosome 8.

Autoradiography

Detailed mapping around the breakpoint of (3;8) translocation in familial renal cell carcinoma and FRA3B.

As a critical step toward cloning the breakpoint of the (3;8) translocation observed in familial renal cell carcinoma and a common fragile site on chromosome 3p (FRA3B), we have characterized the 3p14 region containing the breakpoint and FRA3B by fluorescence in situ hybridization (FISH), pulsed-field gel electrophoresis (PFGE), and genetic linkage analysis. Of 23 cosmids mapped by FISH, 14 cosmids were distal to the breakpoint of t(3;8) and 9 were proximal. Analyses of FRA3B by FISH were identical to those for the (3;8) breakpoint and indicated that the breakpoint of t(3;8) occurred at or very close to the fragile site. We have also constructed a genetic linkage map and a preliminary long-range restriction map using PFGE of the 3p14 region. The linkage results were consistent with the physical data. The combined results of FISH, PFGE, and linkage analysis establish a basis for further experiments to clone the (3;8) breakpoint and FRA3B.

Animals

Isolation and mapping of 68 RFLP markers on human chromosome 6.

We have isolated 68 new RFLP markers on human chromosome 6. Of these, 64 were localized on chromosomal bands by the fluorescent in-situ hybridization (FISH) method, 25 on the short arm and 39 on the long arm. Their distribution was uneven; the markers were localized predominantly in regions of R-positive banding. Eleven markers defined VNTR loci. This expanded collection of DNA markers will contribute to high-resolution linkage mapping of genes causing inherited disorders and will provide useful reagents for isolation of putative tumor-suppressor genes on chromosome 6 that appear to be involved in malignancies. Furthermore, the new markers will be guideposts for detailed linkage and physical maps of this chromosome.

Blotting, Southern

[Studies on stable control of blood sugar by continuous administration of insulin through isolated intestinal loop].

Insulin (INS) has been known to be absorbed through the intestine in small amounts and to decrease blood sugar (BS) levels. However, stable control of BS has not been attained by intestinal intake of INS. To elucidate the possibility of a surgical approach to control hyperglycemic states, Thiry-Vella loops or upper jejunal loop fistulae were constructed in mongrel dogs in hyperglycemic states. Hyperglycemic states (around 400mg/dl) were induced by injecting streptozotocin. Lente insulin was administered every day to control hyperglycemia, except for the days for studies. As we confirmed that co-administration of aprotinin (TR) or nafamostat mesilate (FT) was necessary, to decrease BS by infusing INS into the intestinal loops, safe and effective dose levels were determined by series of preliminary infusion studies in the intestinal loops of diabetic dogs. By continuous infusion of these doses into the jejunal loop fistulae, a long term stable blood sugar control was attained in the diabetic dogs as long as 7 days. These results suggest that continuous infusion of INS with antiproteolytic adjuvants like TR or FT into the isolated small intestinal loop can control BS in hyperglycemic states.

Animals

[Relationship between prolonged life span and changes of serum IAP and albumin induced by the therapy of lentinan plus tegafur in inoperable and recurrent gastric cancer].

Relationship between prolonged life span and changes of serum IAP and albumin induced by the therapy of lentinan plus tegafur were analysed on 43 cases with inoperable and recurrent gastric cancer. Antitumor effect was observed only in one case (2%). Other clinical effects such as improvement of performance status (PS), appetite or pain were observed in 18 cases (42%). Decrease of serum IAP was observed in 25 cases (58%) and increase of albumin was observed in 20 cases (47%). The changes of these two factors seemed to be reversely correlated. Among 30 cases which didn't show decrease of albumin, we found no increase of serum-IAP in 22 cases (72%). In the cases which showed decrease of serum IAP from abnormally high level (more than 500 mu/ml) and increase of albumin from abnormally low level (less than 3.5g/dl), prolonged life span was observed by comparison with the other cases. The cases with any clinical effect contained 78% of the cases without increase of serum IAP, and 72% of the cases without decrease of albumin. These results suggested that life prolongation effect or improvement of clinical symptoms by our therapy was closely related to the change of these serum factors.

Antineoplastic Combined Chemotherapy Protocols

[Effect of prostaglandin E1 derivative on labilization of liver lysosomal membrane in partial liver ischemia].

The change of liver lysosomal enzymes in tissue and serum during a reperfusion period was studied in partial liver ischemic model in rats and effect of Prostaglandin E1 (PGE1) derivative on partial liver ischemia was investigated. Partial liver ischemia was induced by clamping the branches of the vessels to the right and caudate lobes of rat liver. The clamp was released after 30 minutes of ischemia. Ischemic and nonischemic lobes of the liver were separately removed and the serum was also collected immediately and two hours after the release of the clamp. Lysosomal enzyme activities from free and bound lysosomal fraction were measured separately and the fragility index (F.I.) was calculated. PGE1 derivative was administered intraperitoneally 24, 6, 0.5 hours prior to the induction of ischemia at each dose of 0.05 microgram/kg. Pretreatment with PGE1 derivative prevented lysosomal labilization in ischemic lobe, since there was a significant decrease in F.I. of cathepsin D in the PGE1-pretreated group (preischemia; 28.3 +/- 2.4%, immediately after reperfusion; 30.3 +/- 2.5%, two hours after reperfusion; 30.3 +/- 2.5%) compared to the placebo group (immediately after reperfusion; 40.9 +/- 3.4%, two hours after reperfusion; 41.7 +/- 3.4%, p less than 0.05, p less than 0.05, p less than 0.01, respectively). Pretreatment with PGE1 derivative also significantly suppressed the increase of serum lysosomal enzyme activity. These results showed that PGE1 derivative improved liver lysosomal labilization in partial liver ischemia.

Alprostadil