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Biomedical subjects

K Ohashi

Publications and source records attributed to K Ohashi.

At least 361 records · Page 20Linked to original sources
PubMed1994

Characterization of a Marek's disease virus BamHI-L-specific cDNA clone obtained from a Marek's disease lymphoblastoid cell line.

Two Marek's disease (MD) virus BamHI-L-specific cDNA clones were isolated from a cDNA library constructed from poly(A)+ RNA fractions of an MD lymphoblastoid cell line, MDCC-CU41 (CU41). These clones were mapped to the region corresponding to the BamHI-Q2 and L-regions. These clones hybridized with 2.5-, 0.8-, and 0.6-kb transcripts prepared from CU41. The transcriptional unit of the 0.6-kb transcript was determined by RNase protection assays. An open reading frame encoding a 107-amino-acid polypeptide was identified in the 0.6-kb transcript. Reverse transcriptase-PCR demonstrated the presence of this transcript in both CU41 and a reticuloendotheliosis virus-transformed cell line latently infected with MD virus.

Animals↗
PubMed1994

Marine natural products. XXXIII. Theonellapeptolide IId, a new tridecapeptide lactone from the Okinawan marine sponge Theonella swinhoei.

Following the characterization of theonellapeptolides Ia-Ie (2-6), another new tridecapeptide lactone named theonellapeptolide IId (1) was isolated from the Okinawan marine sponge Theonella swinhoei. The structure of 1 has been determined on the bases of chemical and physicochemical examinations which included an HPLC-CD combined analysis of the amino acid composition. Theonellapeptolide IId (1) prevented fertilization of the sea urchin Hemicentrotus pulcherrimus at the concentration of 25 micrograms/ml or greater but did not affect early embryonic development of fertilized eggs up to the gastrula stage.

Amino Acid Sequence↗
PubMed1994

Indonesian medicinal plants. IX. Chemical structures of gongganosides A, B, and C, three new quinovic acid glycosides from the bark of Bhesa paniculata (Celastraceae).

Three new quinovic acid glycosides, named gongganosides A (1), B (2), and C (3), were isolated from the bark of Bhesa paniculata (Celastraceae), an Indonesian medicinal plant collected in Sumatra Island. The chemical structures have been elucidated on the basis of chemical and physicochemical evidence as quinovic acid 3-O-beta-D-xylopyranosyl(1-->3)-alpha-L- rhamnopyranoside for 1,28-O-beta-D-glucopyranosylquinovic acid 3-O-alpha-L-rhamnopyranoside for 2, and 28-O-beta-D-glucopyranosyl-quinovic acid 3-O-beta-D-xylopyranosyl(1-->3)-alpha-L-rhamnopyranoside for 3.

Carbohydrate Sequence↗
PubMed1994

Indonesian medicinal plants. X. Chemical structures of four new triterpene-glycosides, gongganosides D, E, F, and G, and two secoiridoid-glucosides from the bark of Bhesa paniculata (Celastraceae).

Four new triterpene-glycosides, named gongganosides D (4), E (5), F (6), and G (7), and two new secoiridoid-glucosides, (7R)-7-caffeoyloxysweroside (8) and (7S)-7-caffeoyloxysweroside (9), were isolated from the bark of the Indonesian medicinal plant Bhesa paniculata (Celastraceae). The chemical structures have been elucidated on the bases of their chemical and physiocochemical properties.

Carbohydrate Sequence↗
PubMed1994

Chemical transformation of terpenoids. X. Ionophoretic activities of macrocyclic lactone epoxides synthesized from geraniol.

Two coronand-type 18-membered lactone epoxides, i.e., geranyl dimeric lactone diepoxide (GL2E2, 10) and tetraepoxide (GL2E4, 11), were synthesized from geraniol as diastereomeric mixtures. Among them, GL2E4 (11) was shown to exhibit ion-transport activity for Ca2+ ion in the test using a W-07 (liquid-membrane type) apparatus and ion-permeation activities for Ca2+ and K+ ions across the human erythrocyte membrane. Isolation of six component diastereomers of GL2E4 (11) [GL2E4-1 (11c), -2 (11d), -3 (11e), -4 (11f), -5 (11g), -6 (11h)], was effected by HPLC separation of two diastereomeric tetraepoxides (11a, 11b) which were prepared from two diepoxides (GL2E2-1, 10a and GL2E2-2, 10b). The relative stereostructures of these diastereomers were determined by a combination of X-ray diffraction and 1H-NMR analyses. Among the six diastereomers, S2-symmetrical GL2E4-4 (11f) exhibited the strongest ion-transport activity for Ca2+ ion while C2-symmetrical GL2E4-6 (11h) exhibited the strongest ion-permeation activity for Ca2+ ion across the human erythrocyte membrane.

Acyclic Monoterpenes↗
PubMed1994

High rates of Ki-ras point mutation in both intra- and extra-hepatic cholangiocarcinomas.

The presence of the Ki-ras gene mutations in 14 cases of intrahepatic cholangiocarcinoma (IHC) and nine cases of extrahepatic cholangiocarcinoma (EHC) were investigated by polymerase chain reaction-single strand conformation polymorphism analysis. To obtain enriched tumor cell DNA, the microdissection method was used on formalin-fixed paraffin-embedded tissue sections. Point mutations at codon 12 of the Ki-ras gene were detected in seven (50%) of the 14 cases of IHC and six (67%) of the nine EHC cases. In all but one of the ras gene mutation cases, G to A transitions in the second position of codon 12 were detected, the exception being a G to T transition in the same position in one IHC. No point mutations were detected at codon 13 or 61 in either IHC or EHC. Furthermore, there was no demonstrable correlation between Ki-ras mutation and patient age, tumor Stage, histological findings or prognosis. The present results demonstrated a higher participation of Ki-ras gene mutations in EHC than found in previous studies, and provided a confirmation and extension of the results earlier reported by Tada et al. and Tsuda et al. for IHC.

Adult↗
PubMed1994

[The value of hepatic arterial infusion chemotherapy for liver metastases--discussion from viewpoints of prevention of hepatic death and QOL].

The value of hepatic arterial infusion chemotherapy for liver metastases was discussed from the viewpoints of the prevention of hepatic death and the negative effect on QOL, based on the results of repeated hepatic arterial infusion chemotherapy for 128 patients with unresectable liver metastases employing implantable catheter and port system. In 70% of patients, hepatic death due to metastases was prevented by this therapy, and the negative effect on QOL by this therapy was limited. Thus, in spite of the limited effects on the prolongation of survival compared with systemic chemotherapy, there is a reasonable basis for the use of hepatic arterial infusion chemotherapy as a treatment for unresectable liver metastases.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1994

Mucinous cystadenocarcinoma of the pancreas with mucinous biliary obstruction due to uncommon complication of fistulas to the common bile duct and main pancreatic duct.

We report a case of biliary obstruction by a large amount of mucinous material produced by a cystadenocarcinoma of the pancreas invading the common bile duct. This diagnosis was made preoperatively by various imaging methods. Endoscopic retrograde pancreatography (ERP) revealed a mucus-containing cyst with a communication to the main pancreatic and common bile ducts due to a fistulization. Mucinous biliary obstruction was observed. This case indicates that mucinous biliary obstructions should be considered in patients with a mucinous cystic neoplasm of the pancreatic head in the presence of jaundice and that mucinous cystadenocarcinoma may develop into mucinous carcinoma, especially in cases with fistula formations. ERP is useful for detecting the presence of a fistula to the common bile duct or other neighboring organs in such cases. Surgical treatment is recommended because the prognosis of mucinous cystadenocarcinoma is better than that of the usual pancreatic cancer, even though the tumor shows a communication with neighboring organs.

Bile Ducts↗
PubMed1994

Cloning of the cDNA for a novel receptor tyrosine kinase, Sky, predominantly expressed in brain.

Based on homology to the tyrosine kinase domain of the chick erythroblastosis virus oncogene v-sea, we cloned a cDNA encoding a novel receptor tyrosine kinase from a human hepatoma HepG2 cDNA library. The encoded protein, which we termed 'Sky', contains an intracellular tyrosine kinase domain and a unique extracellular domain with two immunoglobulin (Ig)-like domains and two fibronectin type III (FN III) domains. The overall structure of Sky is homologous to the reported sequence of the oncogenic Axl/Ufo receptor tyrosine kinase. Phylogenetic analysis in the tyrosine kinase domain shows that Sky, Axl/Ufo, Ark, and v-Ryk form a sub-family distinct from other tyrosine kinases. Northern blot analysis revealed that sky mRNA is expressed predominantly in brain and faintly in tissues of other organs. As the combination of Ig-like and FN III domains is often observed in neural cell adhesion molecules and receptor protein tyrosine phosphatases, Sky may be involved in cell adhesion processes, particularly in the central nervous system.

Amino Acid Sequence↗
PubMed1994

Identification of a human cDNA encoding a novel protein kinase with two repeats of the LIM/double zinc finger motif.

By low-stringency screening of a human hepatoma HepG2 cell cDNA library, using the genomic fragment of chick c-sea receptor tyrosine kinase as a probe, we isolated overlapping cDNAs encoding a novel protein kinase, which we termed LIM-kinase (LIMK).* The predicted open reading frame encodes a 647-amino-acid polypeptide containing a putative protein kinase structure in the C-terminal half. In addition, LIMK has two repeats of cysteine-rich LIM/double zinc finger motif at the most N-terminus. To our knowledge, this is the first protein kinase seen to contain the LIM motif(s) in the molecule. Although the protein kinase domain of LIMK has highly conserved sequence elements of protein kinases, phylogenetic analysis revealed that LIMK cannot be classified into any subfamily of known protein kinases. Northern blot analysis revealed that the single species of LIMK mRNA of 3.3 kb was expressed in various human epithelial and hematopoietic cell lines. In rat tissues, LIMK mRNA was expressed in the brain, at the highest level. LIM is suggested to be involved in protein-protein interactions by binding to another LIM motif. As the LIM domain is frequently present in the homeodomain-containing transcriptional regulators and oncogenic nuclear proteins, LIMK may be involved in developmental or oncogenic processes through interactions with these LIM-containing proteins.

Amino Acid Sequence↗
PubMed1994

[Postoperative intravesical installation of tetrahydropyranyl-adriamycin (THP) and cytosine arabinoside (CA) for superficial bladder cancer: clinical results of prophylactic effects on recurrence].

Intravesical instillation of tetrahydropyranyl-adriamycin (THP) and cytosine arabinoside (CA) was performed on 42 patients with superficial bladder cancer after transurethral resection (TUR) for the purpose of prophylaxis of recurrence. The instillation was carried out with 30 mg of THP dissolved in 30 ml of distilled water and 200 mg of CA (total 40 ml). These drugs were instilled 7 times for the initial 2 weeks after TUR, and then 7 times every two weeks, 8 times every month, and 4 times every three months. Cases eligible for evaluation of efficacy were 38 out of 42 patients. The cumulative non-recurrence rate at one, two and three years were 94%, 84% and 75%, respectively. These high non-recurrence rates were demonstrated regardless of the size, number and pathological grade of the tumors. Severe bladder irritability was demonstrated in 8 (19%) of 42 patients, but generalized side effects were not seen in any case. The reformed regimen with 20 mg of THP in 30 ml of physiological saline solution was then performed on trial in several patients and there were no severe symptoms. THP combined with CA seems to be remarkably effective for the prophylaxis of recurrence, while a high concentration of THP in distilled water may lead to severe bladder irritability.

Administration, Intravesical↗
PubMed1994

Treatment of pure red cell aplasia after major ABO-incompatible bone marrow transplantation resistant to erythropoietin. Bone Marrow Transplantation Team.

A case of pure red cell aplasia after major ABO-incompatible bone marrow transplantation with long duration of up to 482 days is presented. The patient exhibited resistance to treatment using intravenous gamma globulin, prednisolone and 8 week administration of erythropoietin. The patient finally responded to treatment using erythropoietin and methylprednisolone simultaneously. Because of its safety and efficacy, it might be worthwhile to try erythropoietin with methylprednisolone, if necessary, for pure red cell aplasia complicating major ABO-incompatible bone marrow transplantation.

ABO Blood-Group System↗
PubMed1993

Frequent c-Ki-ras oncogene activation in mucous cell hyperplasias of pancreas suffering from chronic inflammation.

In order to scrutinize the possible significance of (nonatypical) mucous cell hyperplasia of the pancreas to neoplasia, we analyzed these lesions in terms of c-Ki-ras activation, which is known to be very frequent in pancreatic carcinomas. A total of 16 such mucous cell hyperplasias were collected from 10 pancreases resected for chronic pancreatitis. Tiny tissue fragments were taken from hematoxylin-stained sections by microdissection, and DNA analysis was carried out by the polymerase chain reaction amplification and oligonucleotide hybridization methods. Activating mutations of c-Ki-ras oncogene at codon 12 were detected in 10 of the 16 lesions (62.5%), a high rate as seen in carcinomas. The results indicated a clonal origin of cells comprising the mucous cell hyperplasia suggesting a neoplastic and/or precancerous nature.

Adult↗
PubMed1993

Influence of application site of a new transdermal clonidine, M-5041T, on its pharmacokinetics and pharmacodynamics in healthy subjects.

Influence of application site of a new transdermal clonidine, M-5041T(M), on its pharmacokinetics and pharmacodynamics were evaluated in eight human subjects. One patch of M-6 mg was applied for 3 days on the right chest (first trial), on the left arm (second trial), and on the upper abdomen (third trial). Blood samples for clonidine concentration were taken, and blood pressure (BP) was measured for a 120-hour postapplication period. Plasma concentrations of clonidine increased after application of M in each trial. This parameter in the second trial was significantly greater than that of the first and third trials. The values of maximum plasma concentration and area under the plasma concentration-time curve in the second trial were greater than those of other trials, but the differences did not reach significance. The BP-lowering effect of M in the second trial was significantly greater than that of the third trial. These results suggest that the plasma concentrations of clonidine after application of M and its hypotensive effect are affected by the site of application in human subjects.

Abdomen↗