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Biomedical subjects

H Endoh

Publications and source records attributed to H Endoh.

At least 91 records · Page 5Linked to original sources
PubMed1991

Characterization of a tandemly repeated DNA sequence family originally derived by retroposition of tRNA(Glu) in the newt.

A previous report from this laboratory showed that in vitro transcription of total genomic DNA of the newt Cynopus pyrrhogaster resulted in a discrete sized 8 S RNA, which represented highly repetitive and transcribable sequences with a glutamic acid tRNA-like structure in the newt genome. We isolated four independent clones from a newt genomic library and determined the complete sequences of three 2000 to 2400 base-pair PstI fragments spanning the 8 S RNA gene. The glutamic acid tRNA-related segment in the 8 S RNA gene contains the CCA sequence expected as the 3' terminus of a tRNA molecule. Further, the 11 nucleotides located 13 nucleotides upstream from one of the two transcription initiation sites of the 8 S RNA were found to be repeated in the region upstream from the termination site, suggesting that the original unit, which is shorter than the 8 S RNA, was retrotransposed via cDNA intermediates from the PolIII transcript. In the upstream region of the 8 S RNA gene, a 360 nucleotide unit containing the glutamic acid tRNA-related segment was found to be duplicated (clones NE1 and NE10) or triplicated (clone NE3). Except for the difference in the number of the 360 nucleotide unit, the three sequences of the 2000 to 2400 base-pair PstI fragment were essentially the same with only a few mutations and minor deletions. Inverse polymerase chain reaction and sequence determination of the products, together with a Southern hybridization experiment, demonstrated that the family consists of a tandemly repeated unit of 3300, 3700 or 4100 base-pairs. Thus during evolution, this family in the newt was created by retroposition via cDNA intermediates, followed by duplication or triplication of the 360 nucleotide unit and multiplication of the 3300 to 4100 base-pair region at the DNA level.

Animals↗
PubMed1991

Controlled release of 5-fluoro-2'-deoxyuridine by the combination of prodrug and polymer matrix.

Poly(L-lactic acid) (L-PLA) microspheres containing 5-fluoro-2'-deoxyuridine (FUdR) or its ester prodrugs with saturated aliphatic acids (FUdR-Cn, n = 2, 3, 4, 5, 6, 8, 10 and 12) were prepared. The physicochemical and biological properties and antitumor activity of the L-PLA microspheres were studied. The lipophilicity of FUdR-Cn was increased by prolonging its acyl-promoieties. FUdR-C5, FUdR-C6, FUdR-C8, FUdR-C10 and FUdR-C12 showed almost complete incorporation into the microspheres, while incorporation of hydrophilic FUdR and FUdR-C2 was poor. The sustained release of FUdR from the microspheres containing FUdR-C4, FUdR-C5 and FUdR-C6 was obtained in the presence of esterase, and higher antitumor activity against P388 leukemia was observed in vivo. On the other hand, the release rates of FUdR from the microspheres containing FUdR-C10 and FUdR-C12 were very small, and their antitumor activity was much smaller than that of the free prodrug suspension. Effects of the susceptibility to enzymatic hydrolysis and the physiocochemical properties of prodrugs on the release profiles of FUdR from spheres were discussed.

Animals↗
PubMed1990

Characterization of the virA gene of the agropine-type plasmid pRiA4 of Agrobacterium rhizogenes.

We sequenced a 4.2-kb DNA region encompassing the vir A locus of the hairy-root-inducing plasmid pRiA4, and compared its sequence with the published vir A region sequences of four tumor-inducing plasmids. An open reading frame capable of coding for 829 amino acids was identified for vir A. Deletion mutants of vir A constructed by fusing to lacZ, but not the wild-type game itself, were efficiently expressed in Escherichia coli when they were put downstream front the lac promoter. These fused gene products became soluble or insoluble depending on the length of their lacZ moieties.

Amino Acid Sequence↗
PubMed1990

A highly repetitive and transcribable sequence in the tortoise genome is probably a retroposon.

On in vitro transcription of total genomic DNA of the tortoise (Geoclemys reevessi), a discrete-sized RNA of 6.5S was obtained that represented a highly repetitive and transcribable sequence in the tortoise genome. Three sequences of the 6.5S RNA gene were sequenced, and a consensus sequence was deduced from these three sequences and one reported previously [Endoh, H & Okada, N. (1986) Proc. Natl Acad. Sci. USA 83, 251-255]. The 5' part of the gene showed close similaries to lysine (rabbit) and threonine (mouse) tRNAs (overall similarity 68-70%), so this tortoise sequence may have evolved from one of these tRNAs. The consensus sequence retained the expected CCA triplet at the 3' end of tRNA, but not at the 3' end of tDNA, supporting the idea that the tRNA-related region of the gene was generated via an RNA intermediate. The 5' and 3' flanking sequences of the four genes were found to be completely different from each other. Fingerprint analysis and S1 nuclease mapping analysis also showed that sequence boundaries of tortoise repetitive units exactly corresponded to RNA species. These results, together with data obtained by Southern blot hybridization, indicated that the 6.5S RNA genes are dispersed in the tortoise genome. Therefore, generation of the tRNA-related region of the gene and amplification of the whole unit of the gene are both RNA-mediated events. The existence of this tortoise sequence suggests that short interspersed sequences are more common in eukaryotic genomes than had previously been thought.

Animals↗
PubMed1990

Controlled release of 3',5'-diester prodrugs of 5-fluoro-2'-deoxyuridine from poly-L-lactic acid microspheres.

Poly-L-lactic acid (MW 6000) microspheres (PLA-MS) containing 5-fluoro-2'-deoxyuridine (FUdR) or four ester prodrugs of FUdR were prepared and examined with regard to the in vitro release kinetics. The incorporation efficiency of the lipophilic prodrugs into the PLA-MS was higher than that of FUdR or the hydrophilic prodrugs. The release of the lipophilic FUdR prodrugs from PLA-MS was sustained as compared with that of FUdR from PLA-MS. The release kinetics of the FUdR prodrugs appears to fit the Higuchi, Baker, and Lonsdale model in the early stage of the release process. The slope of the Baker and Lonsdale plots of the release of divaleryl-FUdR from PLA-MS decreased as the initial drug loading was decreased. The order of the release rates of FUdR prodrugs from PLA-MS with the same prodrug content was similar to that of the water solubilities of the prodrugs. These results suggest that the ester prodrugs could be released from PLA-MS by diffusion through water-filled capillaries or a series of pores rather than by diffusion through the PLA matrix.

Chemical Phenomena↗
PubMed1989

Plantagoside, a novel alpha-mannosidase inhibitor isolated from the seeds of Plantago asiatica, suppresses immune response.

A hot-water extract from the seed of Plantago asiatica showed a potent inhibitory activity against jack bean alpha-mannosidase, and a flavanone glucoside, plantagoside, was isolated as the inhibitor. Plantagoside was a specific inhibitor for jack bean alpha-mannosidase (IC50 at 5 microM) and appeared to be a non-competitive inhibitor of the enzyme. Whereas, negligible or weak inhibitory activities were observed for beta-mannosidase, beta-glucosidase, and sialidase tested. Plantagoside also inhibited alpha-mannosidase activities in mouse liver lysosomal and microsomal fractions, and the enzyme inhibitory activity in microsomal fraction was enhanced in the presence of glucosidase inhibitor, castanospermine. Plantagoside suppressed antibody response to sheep red blood cells and concanavalin A induced lymphocyte proliferation which was measured by [3H]thymidine incorporation.

Animals↗
PubMed1989

Reevaluation of nonstress test by umbilical venous blood profile using cordocentesis.

Fetal blood sampling by cordocentesis was performed in 85 cases of fetuses with either nonimmune hydrops fetalis, anomalies, intrauterine growth retardation, maternal immunological disorders, Rh incompatibility, hydronephrosis, polyhydramnios, maternal preeclampsia or fetal tumor. Fetal heart rate monitoring was also recorded before cordocentesis. We evaluated the usefulness of the nonstress test (NST) with regard to fetal hematologic gas profiles including pH, pO2 and pCO2. When the acceleration was classified into reactive and nonreactive group, pH and pO2 were significantly higher in the reactive group than in the nonreactive group. pCO2 was significantly lower in the former than the latter. However, the sensitivity and specificity of the reactive NST predicting fetal umbilical venous pO2 over 20 mm Hg was 79.7 and 68.7%, respectively. The false-positive rate of nonreactive NST predicting hypoxemia below 20 mm Hg pO2 was 44%. As a consequence, we cannot always rely on the NST, and should perform fetal blood sampling to assess fetal condition for further management.

Carbon Dioxide↗
PubMed1989

Alteration of FHR pattern and cerebral metabolic rate of glucose of the fetus measured by positron emission tomography during progress of acidemia. The significance of overshoot acceleration in FHR.

In order to investigate the significance of overshoot acceleration in FHR with acidosis induced by serial cord compression, cerebral glucose metabolic rate (CMRglc) was measured in four chronically instrumented fetuses before cord compression and immediately after appearance of the overshoot acceleration in FHR. The investigation of CMRglc was carried out using positron emission tomography to assess accumulation of cyclotron-produced F18-FDG in the fetal brain. CMRglc in the fetal brain in the nonacidemic condition was 1.73 mg/100 g/min. In acidemia, with fetal arterial pH near 7.15 in which FHR showed the characteristic pattern with overshoot acceleration, CMRglc was significantly decreased to 0.73 mg/100 g/min. We concluded that, to avoid neuronal damage, it is necessary to intervene when the fetal condition deteriorates to the extent that overshoot acceleration in FHR occurs.

Acidosis↗
PubMed1989

[Influence of pregnancy and steroid hormones on interferon production of lymphocytes].

A study was done to investigate the involvement of interferon (IFN) in immunological acceptance of fetal allograft. IFN was induced by stimulating OK-432 from lymphocyte of pregnant and nonpregnant women as well as men. There was no difference in the IFN titer in these groups. In pregnant women there was no difference between trimesters, either. In addition, we examined the influence of sex steroid hormones such as progesterone and estrogen on IFN production by the lymphocytes of women and men. Generally, each steroid hormone suppressed the production of IFN. However, the extent of suppression varied with the concentration of hormones, resulting in different suppression curves for men and women in a physiological concentration. Differences in response by men and women were also noticed when interleukin 2 was added to examine whether it could reduce the suppression by steroid hormone. This unique sensitivity of female lymphocyte to steroid hormones may play a role in successfully taking a fetal allograft in pregnancy.

Adult↗
PubMed1988

Production of antiserum against antitumor protein-bound polysaccharide preparation, PSK (Krestin) and its pharmacological application.

Antiserum against a protein-bound polysaccharide preparation (PSK) was produced by immunizing New Zealand White rabbits with PSK. The intestinal absorption of PSK in mice was visualized by indirect immunofluorescent staining with anti-PSK serum. The change in blood levels of 14C after oral administration of 14C-PSK and the recovery of 14C by antiserum were determined. The results indicated that antigenic epitopes in PSK are not completely destroyed during the process of digestion, absorption and distribution, but the changes of serum levels of 14C radioactivity differ from those of immunoreactive radioactivity. These results suggest that multiple processes are involved in the fate of PSK administered orally.

Administration, Oral↗
PubMed1988

Three cases of fetal ascites with successful outcome and seven year evaluation of NIHF: 1981-1987.

Three pregnant women with fetal ascites were admitted to our hospital at 30, 32 and 33 weeks of gestation on diagnosis by sonogram. On sonogram, all the fetuses were initially with marked ascites but without any pleural or pericardial effusion or subcutaneous edema. Under observation by sonogram and cardiotocogram, obstetrical intervention was performed by cesarean section in all 3 cases; at 31 weeks of gestation due to notably increased ascites, at 32 weeks due to fetal distress and at 35 weeks due to development of subcutaneous edema, respectively, and the subsequent courses were uneventful. On the other hand, in our precious experience with 21 cases of NIHF over a period of 7 years, only 2 babies with NIHF have been born alive. We think fetal ascites should be considered an initial sign of NIHF and the successful outcome of these three cases were due to early diagnosis by frequent sonographic examination.

Adult↗
PubMed1988

Several aspects of total genomic DNA transcription in a HeLa cell extract.

Several aspects of total genomic DNA transcription in a HeLa cell extract were described. (1) By using in vitro transcripts from total genomic DNA as probes, we elucidated several structures of short interspersed elements which are transcribed by RNA polymerase III (designated as Pol III/SINEs. (2) To know whether the repetitive sequence we cloned and sequenced comprises a major or minor family, we developed in vitro run-off transcription assay of total genomic DNA. (3) Unlike in vitro transcription of total genomic DNA from vertebrates, major in vitro transcripts from macronuclear total DNA of Tetrahymena were found to be tRNA themselves.

Animals↗
PubMed1988

[Left and right ventricular cardiac outputs in early neonatal periods examined using Doppler echocardiography].

To evaluate early neonatal circulatory adaptation, left and right ventricular cardiac outputs were examined in 10 normal neonates using Doppler echocardiography. Serial examinations were performed until ductal closure was confirmed. Two-dimensional echocardiography and Doppler echocardiography were used to evaluate structures of the heart and great vessels and flow within them. Then, the diameters of the ascending aorta (dAo) and pulmonary artery (dPA) were measured using M-mode echocardiography. The flow velocity patterns of the ascending aorta and pulmonary artery were recorded, measuring mean aortic (VAo) and pulmonary artery velocities (VPA). Left (LVCO) and right ventricular cardiac outputs (RVCO) were calculated as follows: LVCO = (dAo)2/4 x pi x VAo x 60, RVCO = (dPA)2/4 x pi x VPA x 60. 1. Patency of the ductus arteriosus was confirmed by the shunt through it in all neonates initially examined. The initial velocity pattern of the ductal shunts was bidirectional (9/10) or continuous left-to-right (1/10). The flow velocity pattern changed to continuous left-to-right in most neonates, and spontaneous closure of the ductus was confirmed at the age of 13 to 64.5 (mean 31.4) hrs. 2. Left-to-right shunt through the stretched foramen ovale was noted in six neonates temporarily. 3. As for the arterial diameter, dAo did not change, but dPA decreased at the time of spontaneous closure of the ductus. 4. Concerning mean aortic velocity, VAo increased when a continuous ductal left-to-right shunt was initially suspected, while VPA increased when spontaneous closure of the ductus was confirmed. 5. For cardiac output, LVCO (ml/min) changed from 618.4----718.3----562.7, while RVCO showed no change (576.1----546.5----557.8) according to a ductal flow change from bidirectional to continuous left-to-right and finally to no shunt. The LVCO/RVCO ratio increased with increasing age and (in 7/9) the maximal rate was noted when the continuous left-to-right ductal shunt was confirmed. The increased LVCO contributed to the increased LVCO/RVCO ratio. Using this method, serial evaluations of two ventricular cardiac outputs could be made.

Aorta↗
PubMed1987

Effects of pentobarbital and ketamine on brain injury-induced anti-ischemic activity.

Survival rates following incomplete brain ischemia induced during pentobarbital anesthesia were significantly higher in mice with a minor brain injury, inflicted one week before, than in those given a sham operation. Improvement of the survival rates in mice with brain injury, however, became insignificant when brain ischemia was imposed during ketamine anesthesia, suggesting that the actions of certain factors or protective mechanisms against brain ischemia, developed by brain injury, are antagonized by ketamine and/or potentiated by barbiturate anesthesia.

Anesthesia↗
PubMed1987

Tetrahymena actin. Cloning and sequencing of the Tetrahymena actin gene and identification of its gene product.

Actin is ubiquitous in eukaryotes, nevertheless its existence has not yet been clearly proven in Tetrahymena. Here we report the cloning and sequencing of an actin gene from the genomic library of Tetrahymena pyriformis using a Dictyostelium actin gene as a probe. The Tetrahymena actin gene has no intron. The predicted actin is composed of 375 amino acids like other actins and its molecular weight is estimated as 41,906. Both T. pyriformis and T. thermophila possess a single species of actin genes which differ in their restriction patterns. Northern hybridization analysis revealed that the actin gene was actively transcribed in vivo. To detect the gene product, we synthesized an N-terminal peptide of the deduced sequence and prepared its antibody. Using an immunoblotting technique, we identified Tetrahymena actin on a two-dimensional gel electrophoretic plate. The actin spot migrated near an added spot of rabbit skeletal muscle actin, but clearly differed from the latter in its isoelectric point and apparent molecular weight. The primary structure of Tetrahymena actin shares about 75% homology equally with those of other representative actins. This value is extremely low as a homology rate between known actins. Tetrahymena actin diverges not only in relatively variable regions of other actins, but also in relatively constant regions. The hydrophilicity levels of two regions (residues 190 to 200 and residues 225 to 235) are also quite different between the Tetrahymena actin and skeletal muscle actin. Thus, we conclude that actin is present in Tetrahymena, but it is one of the most unique actins among the actins known hereto.

Actins↗
PubMed1986

Total DNA transcription in vitro: a procedure to detect highly repetitive and transcribable sequences with tRNA-like structures.

Total DNAs from various animals were transcribed in vitro in a HeLa cell extract, and it was found that one to several discrete RNAs were transcribed by RNA polymerase III. With tortoise (Geoclemys reevessi) and newt (Cynops pyrrhogaster), distinct 6.5S and 8S RNAs were transcribed from these respective DNAs. Representative phage clones carrying the 6.5S and 8S RNA genes were isolated from genomic libraries of these animals, and the sequences of these genes were determined. The 5' parts of highly repetitive and transcribable sequences of tortoise and newt were found to have close resemblance to tRNALys1 (rabbit) gene (78% homology) and a tRNAGlu (Drosophila) gene (74% homology, not counting the aminoacyl stem region), respectively. The homologies extended to secondary structures, homologous nucleotides being located on similar secondary structures. It is proposed that many, if not all, highly repetitive and transcribable sequences detected by total DNA transcription have specific tRNA genes as their progenitors.

Animals↗