Biomedical subjects

E Kubo

Publications and source records attributed to E Kubo.

At least 37 records · Page 2Linked to original sources

PubMed1998

Retinal vessel changes in galactose-fed dogs.

BACKGROUND: Retinal lesions similar to those in human early-stage diabetic retinopathy have been reported to occur in dogs fed galactose for long periods. Investigations of retinal changes, however, have been limited to studies of the intact retinal vasculature isolated by trypsin digestion. OBJECTIVE: To document the onset and progression of retinal lesions in galactose-fed dogs by the common clinical techniques of fundus color photography and fluorescein angiography. METHODS: Fourteen 6-month-old male beagles made aphakic in 1 eye were divided into a control group (4 dogs), receiving a diet containing 30% cellulose, and a galactosemic group (10 dogs), receiving a diet containing 30% galactose. The progression of retinal changes in these dogs was periodically monitored by color fundus photography and fluorescein angiography. RESULTS: Dogs fed a 30% galactose diet for 28 to 41 months were observed by fluorescein angiography and color fundus photography to develop, in order of frequency, microaneurysms, retinal hemorrhages, intraretinal microvascular abnormalities, retinal nonperfused areas, and varicose and serpiginous veins. These findings are similar to the early clinical retinal changes observed in humans with diabetes. CONCLUSION: These results confirm that galactosemic dogs are an appropriate and suitable animal model for investigating human diabetic retinopathy.

Animals↗

PubMed1998

Cloning and mapping of Np95 gene which encodes a novel nuclear protein associated with cell proliferation.

We previously obtained a monoclonal antibody (Th-10a mAb) that recognizes a single 95-kDa mouse nuclear protein (NP95). Immunostaining analyses revealed that the NP95 was specifically stained in the S phase of normal mouse thymocytes. In contrast, mouse T cell lymphoma cells exhibited a constantly high level of NP95 accumulation irrespective of cell stages during the cell cycle. In the present study, we isolated the cDNA encoding the NP95 from a lambdagt-11 cDNA expression library, using the Th-10a mAb. Sequencing of the whole 3.5-kb cDNA revealed that NP95 is a novel nuclear protein with an open reading frame (ORF) consisting of 782 amino acids. The ORF contains a zinc finger motif, a potential ATP/GTP binding site, a putative cyclin A/E-cdk2 phosphorylation site, and the retinoblastoma protein (RB)-binding motif "IXCXE". The chromosomal location of Np95 gene was determined by fluorescence in situ hybridization. Np95 gene locates on mouse Chromosome (Chr) 17DE1.1. and rat Chr 9q11.2-q12.1. Np95 was strongly expressed in the testis, spleen, thymus, and lung tissues, but not in the brain, liver, or skeletal muscles. These results collectively implicate this novel nuclear protein in cell cycle progression and/or DNA replication.

Amino Acid Sequence↗

PubMed1998

Effect of aldose reductase inhibitor on corneal epithelial barrier function in galactose-fed dogs.

The effect of concomitant administration of galactose and the aldose reductase inhibitor(ARI) Epalrestat (Kinedak) on corneal barrier function was examined in dogs. Six-month-old male beagles were rendered aphakic in one eye and then divided into four groups as follows: 1) a control group fed on 30% cellulose, 2) a galactosemic group fed on 30% galactose, 3) a 30% galactose-fed group treated with low dose (20 mg/kg) ARI and 4) a 30% galactose-fed group treated with high dose (50 mg/kg) ARI. Forty-one months after the start of these diets, corneal autofluorescence and the corneal barrier function were measured in each dog using anterior fluorophotometry (FL-500). When barrier function was analyzed in non-operated eyes, fluorescence data were significantly higher in the galactosemic group compared to the control group. In non-operated eyes, fluorescent data in high-dose ARI treated group were significantly lower than those in the galactosemic group. However, in operated eyes, no significant difference was observed between the galactosemic group and the ARI treated groups. Similar trends were observed when corneal autofluorescence of each group was compared. Long-term galactose feeding appeared to damage corneal epithelial barrier function. This damage was not observed in the high-dose ARI treated group suggesting that this damage may be linked to the polyol pathway.

Aldehyde Reductase↗

PubMed1998

3-FG as substrate for investigating flux through the polyol pathway in dog lens by 19F-NMR spectroscopy.

PURPOSE: To investigate flux through the polyol pathway in the dog lens by 19F-nuclear magnetic resonance (19F-NMR) spectroscopy, using 3-fluoro-3-deoxy-D-glucose (3-FG) as a substrate. METHODS: 3-FG metabolism was monitored by 19F-NMR analysis. Dog lenses were incubated in Dulbecco's modified Eagle's medium containing 10 mM 3-FG. Enzymatic reductase and dehydrogenase activities were spectrophotometrically determined, whereas the analyses of 3-FG metabolites were conducted by 19F-NMR analysis. Aldose reductase (AR) was immunohistochemically localized in dog lens with antibodies raised against dog kidney AR. RESULTS: 19F-NMR spectra indicate that incubation of purified dog lenses AR with 3-FG results in the formation of 3-fluoro-3-deoxy-D-sorbitol (3-FS) and that incubation of dog liver sorbitol dehydrogenase (SDH) with 3-FS results in the formation of 3-fluoro-3-deoxy-D-fructose (3-FF). This confirms that 3-FG is metabolized to 3-FF by the polyol pathway enzymes. The affinity (Km) of AR for 3-FG is approximately 20-fold better than that for D-glucose, whereas the Km of SDH for 3-FS was fourfold less than for D-sorbitol. 3-FG in cultured dog lenses is metabolized primarily to 3-FS; however, small amounts of 3-FF and 3-fluoro-3-deoxy-D-gluconic acid (3-FGA) are also formed. 3-FS formation was reduced by the AR inhibitor AL 1576, and 3-FF formation was eliminated by the SDH inhibitor CP-166,572. In dog lens epithelial cells cultured with 3-FG, only 3-FS is formed. Similarly, only 3-FS is formed when lens capsule containing primarily epithelial lens contaminated with superficial epithelial cells was incubated in 3-FG. Similar incubation of the remaining cortex resulted primarily in the formation of 3-FS and 3-FGA. This enzymatic distribution was confirmed by spectrophotometric activity analysis and the immunohistochemical localization of AR. CONCLUSIONS: The data confirm that flux through the polyol pathway primarily results in sorbitol accumulation. The absence of fructose and gluconic acid from cultured lens epithelium suggests that the epithelial cells primarily contain AR, whereas differentiated fiber cells also contain SDH and glucose dehydrogenase.

Aldehyde Reductase↗

PubMed1996

Analysis of early initiating event(s) in radiation-induced thymic lymphomagenesis.

Since the T cell receptor rearrangement is a sequential process and unique to the progeny of each clone, we investigated the early initiating events in radiation-induced thymic lymphomagenesis by comparing the oncogenic alterations with the pattern of gamma T cell receptor (TCR) rearrangements. We reported previously that after leukemogenic irradiation, preneoplastic cells developed, albeit infrequently, from thymic leukemia antigen-2+ (TL-2+) thymocytes. Limited numbers of TL-2+ cells from individual irradiated B10.Thy 1.1 mice were injected into B10.Thy 1.2 mice intrathymically, and the common genetic changes among the donor-type T cell lymphomas were investigated with regard to p53 gene and chromosome aberrations. The results indicated that some mutations in the p53 gene had taken place in these lymphomas, but there was no common mutation among the donor-type lymphomas from individual irradiated mice, suggesting that these mutations were late-occurring events in the process of oncogenesis. On the other hand, there were common chromosome aberrations or translocations such as trisomy 15, t(7F;10C), t(1A;13D) or t(6A;XB) among the donor-type lymphomas derived from half of the individual irradiated mice. This indicated that the aberrations/translocations, which occurred in single progenitor cells at the early T cell differentiation either just before or after gamma T cell receptor rearrangements, might be important candidates for initiating events. In the donor-type lymphomas from the other half of the individual irradiated mice, microgenetic changes were suggested to be initial events and also might take place in single progenitor cells just before or right after gamma TCR rearrangements.

Animals↗

PubMed1996

Cytogenetic analysis of thymocytes during early stages after irradiation in mice with different susceptibilities to radiation-induced lymphomagenesis.

To investigate the relationship between radiation-induced chromosomal instability and lymphomagenesis, the incidences of chromosome aberrations and of cells with abnormal chromosome complements in the thymuses of B10. Thy 1.1 and STS/A strains which have shown marked differences in susceptibility to radiation-induced lymphomagenesis were compared at an early time (12-33 days) after whole-body X-irradiation (1.61 Gy X 4). Numerical and structural aberrations of chromosome in B10. Thy 1.1 mice were higher than those in STS/A mice. The average incidence of trisomy 15 was 37.5% (12/32 mice) from 12 days to 32 days after irradiation in B10. Thy 1.1 mice, whereas none was found (0/38 mice) in STS/A mice. Frequencies of aberrations in chromosomes 11, 12, 15 of the thymocytes from irradiated B10. Thy 1.1 mice were higher than those from irradiated STS/A mice, and especially, the most frequent translocations occurred in the E-F regions of chromosome 12. using B10. Thy 1 congenic mice, we found that in many cases (8/13), the chromosome aberrations detected in the thymocytes from B10. Thy 1.1 mice at an early time after irradiation could also be observed in the donor-type (Thy 1.1) lymphomas developed from recipient mice 4-5 months after intrathymic injection, suggesting that these chromosome aberrations have some role in lymphomagenesis. The difference of chromosome instability detected at an early time after irradiation might be due to genetic background with regard to genomic instability induced by radiation.

Animals↗

PubMed1996

[Histological observation of anterior capsular edges produced by continuous curvilinear and diathermy capsulorhexis].

Radiofrequency endodiathermy capsulorhexis (DC) is a new method for anterior capsulorhexis in cataract surgery. DC may confer some advantages over continuous curvilinear capsulorhexis(CCC) in certain clinical situations. The elasticity of capsulorhexis produced by DC and the proper diathermy time are still unclear. Histological examination of rabbit lenses, on which a variety of coagulation times (0.5 to 5.0 sec) were tested revealed that 0.5 sec was long enough to coagulate the anterior capsule and that the longer coagulation extend the tissue damage into the deeper cortex. Small capsulorhexis (3.5 mm in diameter) produced experimentally with DC showed less elasticity than that produced with CCC when the edge of the capsulorhexis was pulled. Thus the heat coagulation of the capsular edge produced by DC results in less elasticity than that produced by CCC.

Animals↗

PubMed1995

The characterization of the monoclonal antibody Th-10a, specific for a nuclear protein appearing in the S phase of the cell cycle in normal thymocytes and its unregulated expression in lymphoma cell lines.

A monoclonal antibody (Th-10a) specific for the nuclear protein appearing in the S phase of the cell cycle in normal mouse thymocytes was derived by immunizing Wistar rats with a murine thymic lymphoma (TIGN), and its isotype was rat IgG2a and had kappa light chain. Immunohistochemical staining of frozen sections of B10.Thy1.1 newborn thymus and embryonic intestine revealed that this monoclonal antibody reacted strongly with the nuclear proteins of subcortical thymocytes and the basal layer of the mucosa, where many cells were dividing, but not with that of the thymic medullary area. To evaluate the expression of the nuclear proteins during the cell cycle in detail, the results of an immunofluorescence analysis of the thymocytes from hydroxyurea-treated B10 mice using Th-10a monoclonal antibody were compared with those of DNA synthesis of these cells with the use of the FITC-conjugated anti-BrdUrd monoclonal antibody. The results indicated that the nuclear protein detected by Th-10a monoclonal antibody was highly expressed in the S phase of normal thymocytes, while the cells in G1, G2 and M phases exhibited a low level of the expression. Moreover, the variations in expression of the nuclear proteins in the thymocytes at different times after hydroxyurea treatment were observed to correspond with the frequency of DNA synthesizing cells. In contrast, the high level and unregulated expression of the nuclear protein detected by Th-10a monoclonal antibody was observed throughout the cell cycle of the mouse lymphoma cell lines examined. Since Th-10a monoclonal antibody does not react with the nuclear proteins derived from human, hamster or rat proliferating cells, this antibody may recognize a murine specific epitope of the nuclear protein. To further characterize the nuclear proteins, we extracted them from normal thymocytes or thymic lymphomas, and analysed them by immunoblotting or immunoprecipitation followed by SDS-polyacrylamide gel electrophoresis. The nuclear protein(s) detected by Th-10a monoclonal antibody was mostly 95 kDa and also 83 kDa polypeptide. The results also indicated that the 95 kDa nuclear protein was phosphorylated in vivo.

Animals↗

PubMed1995

[Cell kinetics of rat lens epithelium by cytofluorometric nuclear DNA determination].

The cell kinetics of rat lens epithelium was assessed by measuring the changes in the nuclear DNA contents during sugar cataract formation. Six-and-12-week-old Sprague-Dawley male rats were used and divided into the following groups: fed on normal chow, fed on 25% galactose diet, and fed on normal chow after 5 days on the 25% galactose diet. Every second day following the beginning of each chow feeding, lenses were extracted, and lens capsules with epithelial cells were obtained. After a few day's fixation in 4% paraformaldehyde dissolved in 0.1M phosphate buffer (pH 7.4), DAPI (4'6-diamidino-2-phenylindole)-stained lens epithelial cells were measured by fluorescence cytophotometry. The epithelia in the normal chow-fed rats contained many 2C and a few 4C nuclei. In the 25% galactose-fed rats, 4C nuclei increased gradually in number until the fifth day, and then decreases slowly day by day. Abnormal polyploid nuclei (8C) were observed in the 25% galactose-fed rats. 4C nuclei decreased rapidly after the diet reversal. These results indicate that galactose feeding caused higher DNA synthesis of rat lens epithelial cells and a higher possibility of abnormal cell division.

Animals↗

PubMed1994

Prostaglandin D2-sensitive, sleep-promoting zone defined in the ventral surface of the rostral basal forebrain.

The site of action for the sleep-promoting effect of prostaglandin (PG) D2 was extensively examined in the brain of adult male rats (n = 231). PGD2 was administered at 100 pmol/0.2 microliter per min for 6 hr (2300-0500 hr) through chronically implanted microdialysis probes or infusion cannulae. Among the administrations of PDG2 by dialysis probes (n = 176), only those (n = 8) to a ventro-rostral part of the basal forebrain by the probes implanted on the midline consistently increased slow-wave sleep (SWS), by 51 +/- 6 min (mean +/- SEM) above the baseline value (111 +/- 11 min). Since this area is separated by a cleft into right and left regions, the results were interpreted to mean that, through this cleft, PGD2 diffused in the subarachnoid space over the adjacent ventral surface, where it had the effect of promoting sleep. When PGD2 was directly infused into the subarachnoid space (n = 55), extraordinary increases exceeding 90 min were consistently attained for the SWS at sites located between 0.5 and 2 mm rostral to the bregma and between 0 and 1.2 mm lateral to the midline defined according to the stereotaxic coordinates adopted from the brain atlas of Paxinos and Watson [Paxinos, G. & Watson, C. (1986) The Rat Brain in Stereotaxic Coordinates (Academic, San Diego)]. Thus, we demarcated a "PGD2-sensitive, sleep-promoting zone" within this region in the ventral surface of the rostral basal forebrain. During the bilateral infusion of PGD2 into the subarachnoid space of this zone, the hourly mean SWS level of the nocturnal animals (n = 6) in the night reached the maximum at the second hour of the infusion period; this maximum hourly SWS level, corresponding to the daytime level of the same animals, lasted until the end of PGD2 infusion.

Animals↗

PubMed1994

Effects of prostaglandin D2, lipoxins and leukotrienes on sleep and brain temperature of rats.

Prostaglandin (PG) D2 and four lipoxygenase-derived eicosanoids [lipoxins (LX) A4 and B4, and leukotrienes (LT) C4 and D4] were examined for their effects on sleep and brain temperature in freely-behaving rats. In the first series of experiments, PGD2 was infused into the third ventricle at four different locations between 23:00 and 05:00. In a location apposed to the medial preoptic area (MPO), PGD2 at doses 1, 10 and 100 pmol/min, increased the slow wave sleep (SWS) by 23% (p < or = 0.01), 35% (p < or = 0.05) and 44% (p < or = 0.01), respectively, during the infusion period. In the second series of experiments, LXs and LTs were infused at the location apposed to MPO. Significant increases in SWS were detected with LXA4 at 100 pmol/min (14%, p < or = 0.05), LXB4 at 100 pmol/min (20%, p < or = 0.05), and LTD at 10 pmol/min (17%, p < or = 0.05). An increase in paradoxical sleep (PS) was produced by PGD2 at 1 and 10 pmol/min infusion (p < or = 0.05), but not by any of the lipoxygenase-derived eicosanoids examined. PGD2 also elevated the mean brain temperature during infusion by 0.2 degrees C and 0.9 degrees C at infusion doses 10 and 100 pmol/min, respectively. But PGD2 infusion at 1 pmol/min did not elevate the brain temperature. LXs (excluding LXB4 at 100 pmol/min) and LTs did not alter the brain temperature significantly at the tested doses. We conclude that PGD2 is the most effective sleep promoter among the eicosanoids examined so far.

Animals↗

PubMed1994

Cavernous lymphangioma of the spleen in a patient with Klippel-Trenaunay-Weber syndrome.

A 31-year-old woman presented with hypertrophy of the left upper extremity and thrombocytopenia. Physical examination revealed splenomegaly, and laboratory investigation revealed thrombocytopenia, elevation of cross-linked fibrin degradation products (XDP), and thrombin-antithrombin III complex (TAT). A diagnosis of Klippel-Trenaunay-Weber (K-T-W) syndrome was established by the dermatologic findings and angiography of the extremities. A splenic cavernous lymphangioma was diagnosed by ultrasonography and angiography, and was confirmed by pathology following splenectomy. Post-operatively, the platelet count increased, and hemostatic parameters normalized. Cavernous lymphangioma is a rare complication of Klippel-Trenaunay-Weber syndrome. Splenectomy proved to be an effective therapy for both cavernous lymphangioma and consumptive coagulopathy in Klippel-Trenaunay-Weber syndrome.

Adult↗

PubMed1993

Intravenous administration of inorganic selenium compounds, inhibitors of prostaglandin D synthase, inhibits sleep in freely moving rats.

Prostaglandin (PG) D2 has been postulated to be an endogenous sleep-promoting factor. Biosynthesis of PGD2 is catalyzed by PGD synthase (prostaglandin-H2 D-isomerase, EC 5.3.99.2), the activity of which is inhibited by inorganic selenium compounds such as SeCl4 and Na2SeO3. We recently examined the effect of intracerebroventricular administration of these selenium compounds on sleep in rats, and demonstrated time- and dose-dependent sleep inhibition. To establish whether this effect of selenium is also produced when the compound is administered systemically, we devised a procedure for intravenous catheterization and examined the effect of these selenocompounds on sleep-wake activity in freely moving rats (n = 35). Each test compound was administered into the inferior vena cava continuously between 11.00 and 17.00 h on the experimental day. SeCl4 time- and dose-dependently inhibited sleep at infusion rates of 5, 7.5, 10 and 20 nmol/microliters per min. During the SeCl4 infusion at 20 nmol/microliters per min, slow-wave sleep and paradoxical sleep were reduced to 63% and 50% of their respective baseline values. Na2SeO3 exhibited a similar sleep inhibition, though Na2SO3 was ineffective. Infusion of SeCl4 at 10 nmol/microliters per min or below produced no consistent changes in the mean brain temperature, or food and water intake during the infusion period. During the nocturnal period subsequent to SeCl4 infusion, sleep was increased by a rebound phenomenon, while a decrease in brain temperature and inhibition of food and water intake dose-dependently occurred. We conclude that systemic administration of these PGD synthase inhibitors has a sleep-reducing potency.

Animals↗

PubMed1993

Multiple pre-neoplastic events and clonal selection of radiation induced mouse thymic lymphomas shown by TCR gene rearrangements.

After split-dose irradiation, pre-lymphoma cells develop from a tumor-specific surface antigen TL-2+ thymocyte subpopulation. To analyze the clonality of pre-lymphoma cells, various numbers of TL-2+ thymocytes from a single irradiated mouse were intra-thymically injected to Thyl congenic recipient mice. The incidence of donor type thymic lymphoma(s) was subsequently examined in a group of recipient mice. We chose several lymphomas derived from a single donor mouse and analyzed the TCR gene rearrangements and V(D)J junctional diversity as genetic markers of clonality. These results indicate multiple initial neoplastic events and clonal selection into lymphoma.

Amino Acid Sequence↗

PubMed1993

Bilateral anomalous insertion of flexor pollicis longus.

A case of bilateral insertion of flexor pollicis longus to the proximal as well as the distal phalanges is reported. Initially, this case was diagnosed as congenital absence of the flexor pollicis longus, but surgery revealed an intact tendon, with the abnormality only present in the site of insertion. A survey of the literature on congenital abnormalities of flexor pollicis longus failed to reveal any reports of similar abnormalities.

Congenital Abnormalities↗

PubMed1993

Mouse germline transcript of TCR alpha joining region and temporal expression in ontogeny.

The genetic element 'T early alpha' (TEA) in humans is located immediately 5' to the most upstream joining segment (phi J alpha) of the TCR alpha chain locus. The TEA transcript is present early in thymocyte ontogeny and the TEA-associated deletion of the TCR delta locus (delta Rec/phi J alpha rearrangement) precedes V alpha/J alpha rearrangement. We detected a 1.8 kb transcript homologous to human TEA that is spliced to C alpha in mouse thymic lymphomas showing concomitant rearrangement and expression of TCR gamma, delta, beta, and alpha. The TEA expression was highest in day 17 fetal thymocytes and declined thereafter. This expression parallels the TCR delta gene expression which is preceded by TCR gamma expression, and followed by the expression of TCR beta and alpha genes.

Animals↗

PubMed1993

[Tetralogy of Fallot with aortopulmonary window: report of a successful repair].

Tetralogy of Fallot is rarely associated with aortopulmonary window. A 6-month-old boy with tetralogy of Fallot, aortopulmonary window, pulmonary atresia, patent left superior vena cava and right aortic arch was operated successfully. Both great arteries were divided, the defect in the aortic wall was closed directly, and the defect in the pulmonary arterial wall was connected with a valved external conduit which was used for right ventricular outflow tract reconstruction. Although oliguria had been prolonged for 3 weeks post operatively, he recovered completely and RV/LV pressure ratio was less than 0.6 estimated by two-dimensional echocardiography at one month after operation.

Aortopulmonary Septal Defect↗

PubMed1993

[A case report of aortic valve stenosis combined with complete A-V block during chronic hemodialysis].

A 52-year-old man treated by hemodialysis under the diagnosis of chronic renal failure admitted to our hospital due to aortic valve stenosis and complete A-V block. Aortic valve was severely calcified, and the cause of complete A-V block was considered caused by the progressive calcification invasing to conduction system. The aortic valve replacement and pacemaker implantation using myocardial lead were simultaneously. Postoperative course was uneventful. The efficacy of simultaneous operation of aortic valve and pacemaker implantation was emphasized. However the generator implantation was recommended to perform in the several days after the operation because of destruction of the pacemaker function by counter shock for arrhythmia in the early post operative period.

Aortic Valve Stenosis↗