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Biomedical subjects

Y Uematsu

Publications and source records attributed to Y Uematsu.

At least 19 recordsLinked to original sources

Activities of enzymes in the malate-aspartate shuttle and the isoenzyme pattern of lactate dehydrogenase in plasma and peripheral leukocytes of lactating Holstein cows and riding horses.

The activities of the enzymes involved in the malate-aspartate shuttle and lactate dehydrogenase (LDH) and the pattern of the isoenzymes of LDH were determined in plasma and peripheral leukocytes of lactating Holstein cows and thoroughbred riding horses as representative herbivorous animals. In the horse plasma, LDH activities were significantly lower and AST activities were significantly higher than those in the cow plasma. The specific activities of cytosolic malate dehydrogenase (MDH), LDH and AST in the horse leukocytes were higher than those in the cows. The cytosolic ratio of MDH/LDH activity (ML ratio) in the horse leukocytes was significantly lower than that in the cow leukocytes owing to significantly higher activities of LDH. The ML ratio was considered to reflect the difference in energy metabolism in leukocytes between cows and horses. The plasma LDH isoenzyme patterns of cow and horse showed the characteristic as herbivorous animals with dominance of LDH-1, -2 and -3. The LDH isoenzyme patterns with dominance of LDH-3 and -4 in the horse leukocytes were remarkably different from those in the cow leukocytes. There were significant differences in activities of malate-aspartate shuttle enzymes, ML ratio and LDH isoenzyme patterns in the cytosolic fractions of leukocytes between the lactating cows and the riding horses.

Amino Acid Oxidoreductases↗

Molecular analysis of V(H)I+ B lymphocytes in hepatitis C patients.

BACKGROUND AND AIMS: Hepatitis C virus infection is often associated with lymphoproliferative disorders such as essential mixed cryoglobulinemia and B-cell non-Hodgkin lymphoma, which show preferential expression of VHI family products. By analyzing immunoglobulin heavy chain usage, we addressed the question of whether or not clonal B-cell expansion occurrs in patients free of essential mixed cryoglobulinemia or non-Hodgkin lymphoma. PATIENTS AND METHODS: Four hepatitis C virus-positive patients, all undergoing liver transplantation, were studied. Peripheral blood, intra-hepatic, and lymph node lymphocytes were used as a source of B cells. A patient with hepatocellular carcinoma and fresh blood from four healthy donors were used as negative controls. VHI family sequences were cloned and analyzed by reverse transcription-polymerase chain reaction. RESULTS: Immunoglobulin heavy chain sequences from clonally expanded B lymphocytes were identified in three out of four hepatitis C virus-infected patients. The clonally expanded B lymphocyte populations showed a broad spectra of immunoglobulin heavy chain gene usage. CONCLUSIONS: HCV infection can induce B-cell expansion with larger clonal variation. The restricted V gene usage in hepatitis C virus-associated non-Hodgkin lymphoma suggests that there may be selection mechanisms to develop non-Hodgkin lymphoma from non-malignant, clonally expanded B-cell populations in hepatitis C virus-infected patients.

B-Lymphocytes↗

Cytosolic ratio of malate dehyrogenase/lactate dehydrogenase activity in peripheral leukocytes of race horses with training.

The activities of the enzymes involved in the malate-aspartate shuttle and m RNA expression of malate dehydrogenase (MDH), a crucial enzyme for the NADH shuttle that produces ATP in glucose metabolism in the peripheral leukocytes of horses, were measured to investigate the change in metabolic states with training. There were no significant differences in plasma glucose and immunoreactive insulin concentrations between race horses and riding horses, used as a comparable reference. The cytosolic and mitochondrial MDH activities in leukocytes of race horses were significantly higher than those of riding horses. High activities of MDH in leukocytes of race horses were confirmed by RT - PCR analysis on the total RNA extracted from the whole blood. The cytosolic ratio of MDH /lactate dehydrogenase (LDH) activity (M/L ratio) in leukocytes of race horses was significantly higher than in those of riding horses. Increase in the M/L ratio was considered to reflect elevation of energy metabolism in animal tissues. The M/L ratio may be a useful parameter to evaluate the difference in metabolic states between race horses and riding horses.

Animals↗

Survey of residual solvents in natural food additives by standard addition head-space GC.

Residual levels of 12 solvents in 87 natural food additives (66 samples of food colours, 19 samples of natural antioxidants and two natural preservatives) collected between 1997 and 1999 were determined by automated head-space GC using FID, with a porous-polymer (PLOT) column. Calibration curves were prepared by the method of standard addition. Confirmation was by manually injected head-space GC using mass spectrometric detection. 1,2-Dichloroethane was found in turmeric colour (natural food colour) collected in 1997 at the concentrations of 8.6 microg g(-1), but was not found in samples collected in 1998 and 1999. Hexane was found in three samples of dunaliella carotene (11, 72 and 75 microg g(-1)), and in chlorophyll at 93 microg g(-1) (both natural food colours). Acetone was found in turmeric colour, annatto colour, dunaliella carotene, kaoliang colour, cacao colour at a concentration between 8.7 and 42 microg g(-1) (all natural food colours).

Antioxidants↗

Reconstruction of a scalp and skull defect with free latissimus dorsi myocutaneous flap following dermatofibrosarcoma protuberans.

A 53-year-old male underwent more than 10 surgical treatments over 14 years, including a simple excision and local flap transfer, after recurrences of dermatofibrosarcoma protuberans of the head. Clinical results indicated that simple excision of dermatofibrosarcoma protuberans should not be performed as initial treatment. Instead, free flap transplantation, which permits a wide excision and complete reconstruction, should be the first treatment option.

Dermatofibrosarcoma↗

The small extracellular loop of CD81 is necessary for optimal surface expression of the large loop, a putative HCV receptor.

Human tetraspanin CD81 is a putative receptor for hepatitis C virus (HCV), because it has been shown to bind 'bona fide' HCV particles. CD81, as all tetraspanins, spans the membrane four times forming two extracellular loops: a small (SEL) and a large one (LEL). We have shown previously that a recombinant form of LEL is sufficient for binding HCV through the major envelope glycoprotein E2. The role of SEL in the CD81-HCV interaction was questioned. We found that transfectants expressing LEL alone bind the recombinant HCV-E2 protein at much lower levels than cells expressing the wild type CD81. And therefore whether SEL contributes to the CD81-HCV interaction or whether it influences the expression of LEL was examined. We have found that in the absence of SEL, LEL is expressed at significantly reduced levels on the cell surface because it is retained intracellularly, while HCV-E2 still binds LEL. Our data suggest that SEL of CD81 does not mediate interaction with HCV, but contributes to optimal cell surface expression of LEL by mediating translocation of the whole CD81 molecule to the cell surface.

3T3 Cells↗

Symptoms of thoracolumbar junction disc herniation.

STUDY DESIGN: A retrospective clinical review of patients with thoracolumbar junction disc herniation. OBJECTIVES: To evaluate the clinical features of thoracolumbar junction disc herniation and to prepare a chart for the level diagnosis in the neurologic findings and symptoms. SUMMARY OF BACKGROUND DATA: Thoracolumbar junction disc herniations show a variety of signs and symptoms because of the complexity of the upper and lower neurons of the spinal cord, cauda equina, and nerve roots. Furthermore, much is still unknown about thoracolumbar junction disc herniations because of their rare frequency. METHODS: The clinical features of 26 patients who had undergone operations for single disc herniations at T10-T11 through L2-L3 were investigated. Affected levels were as follows: 2 patients with disc herniation at T10-T11 disc, 4 patients at T11-T12, 3 patients at T12-L1, 6 patients at L1-L2, and 11 patients at L2-L3. The level of disc space of interest was confirmed with whole-spine plain roentgenograms. The caudal end of the cord was judged by magnetic resonance imaging and computed tomographic myelogram. RESULTS: Two patients with T10-T11 disc herniation showed moderate lower extremity weakness, increased patellar tendon reflex, and sensory disturbance of the entire lower extremities. Three of four patients with T11-T12 disc herniation experienced lower extremity weakness, and three patients had accentuated patellar tendon reflex. Sensory disturbance was observed in the anterolateral aspect of the thigh in one patient and on the entire leg in three patients. Bowel and bladder dysfunction was noted in three patients. In the T12-L1 disc herniation group (n = 3), muscle weakness and atrophy below the leg were advanced, and bowel and bladder dysfunction were also noted. Two of these three patients had bilateral drop foot, and one patient had unilateral drop foot; sensory disturbance was noted in the sole or foot and around the circumference of the anus, and the patellar tendon reflex and Achilles tendon reflex were absent. All six patients with L1-L2 disc herniation showed severe thigh pain and sensory disturbance at the anterior aspect or lateral aspect of the thigh. On the other hand, there were no clear signs of lower extremity weakness, muscle atrophy, deep tendon reflex, or bowel and bladder dysfunction in these patients. In the L2-L3 disc herniation group (n = 11), all patients had severe thigh pain and sensory disturbance of the anterior aspect or the lateral aspect of the thigh. Weakness in the quadriceps was noted in five patients and weakness in the tibialis anterior in two patients. Decreased or absence of patellar tendon reflex was observed in nine patients. Five patients had positive straight leg raising test results, and eight patients showed positive femoral nerve stretch test results. CONCLUSION: Among thoracolumbar junction disc herniations, T10-T11 and T11-T12 disc herniations were considered upper neuron disorders, T12-L1 disc herniations were considered lower neuron disorders, L1-L2 disc herniations were considered mild disorders of the cauda equina and radiculopathy, and L2-L3 disc herniations were considered radiculopathy. These findings had relatively distinct differences among herniated disc levels.

Adult↗

Effects of nicotine on the intervertebral disc: an experimental study in rabbits.

Clinically, we have observed that a large proportion of patients presenting with low back pain as the chief complaint are smokers. It was therefore postulated that smoking might affect the intervertebral disc. We investigated the histological and functional effects of nicotine on intervertebral discs in rabbits. Rabbits were implanted subcutaneously with minipumps for the delivery of 200 microg/ml nicotine for 4 or 8 weeks. The selected dose produced blood nicotine levels equivalent to those found in heavy smokers (30 cigarettes/day). Nicotine injection caused necrosis and fibrous tissue and vitreous formation in the nucleus pulposus of the intervertebral disc, as well as hypertrophy of the fibrous ring, with partial cracks and detachment. Measurement of collagen and proteoglycan production in intervertebral discs showed reduced synthesis of these proteins in nicotine-treated rabbits compared with the control findings. Our results indicated that the harmful effects of nicotine on the integrity of the intervertebral disc might be mediated by the direct effect of nicotine, or indirectly, by causing vasoconstriction of the vascular network surrounding the intervertebral discs.

Animals↗

Gamma knife radiosurgery for neuroepithelial tumors: radiological and histological changes.

Gamma knife radiosurgery (RS) has been introduced as a modern therapy for brain tumors. However, the effects of RS for neuroepithelial tumors are still obscure. The present study investigates the radiological and histological changes after RS to elucidate the biological effect. There were seven cases (two males and five females), ranging from 4 to 71 years with a mean age of 33 years. Two cases were located in the brainstem, another two in the cerebellum, and one each in the thalamus, the hypothalamus, and the frontal lobe. Histologically, two cases had gangliogliomas, four astrocytomas (1 pilocytic, 1 fibrillary, 2 anaplastic), and one glioblastoma. RS was performed after surgery with a central dose of 30-36 Gy. All cases were evaluated radiologically on MRI before and after RS. Four cases (3 astrocytomas and 1 glioblastoma) which neurologically deteriorated after RS were reoperated. These cases were examined using HE and immunohistochemical studies with antibodies of CD34, alpha-smooth muscle actin (SMA), p53, p21 and MIB-1 on the sections before and after RS. MRI demonstrated perifocal edema and intratumoral hypointensity on T2 weighted imaging (T2WI), suggesting radionecrosis in most of the cases within 6 months after RS. In the central part of the RS, destructive changes were observed in the tumor cells and endothelial cells: decrease in the tumor cell population, coagulation necrosis, and fibrinoid degeneration of vascular walls were revealed. In the peripheral part, however, some tumors contained viable tumor cells intermingled with blood vessels showing endothelial and pericytic proliferations. The increase of MIB-1 staining index was found in only one case. The p21 immunoreactivity was increased in endothelial cells, although the p53 immunoreactivity was unchanged. These results suggested that radionecrosis occurred earlier and more frequently in neuroepithelial tumors after RS than after conventional radiation.

Adolescent↗

Chlorohydrins of bisphenol A diglycidyl ether (BADGE) and of bisphenol F diglycidyl ether (BFDGE) in canned foods and ready-to-drink coffees from the Japanese market.

BADGE.2HCl and BFDGE.2HCl were determined in 28 samples of ready-to-drink canned coffee and 18 samples of canned vegetables (10 corn, 5 tomatoes and 3 others), all from the Japanese market. HPLC was used as the principal analytical method and GC-MS for confirmation of relevant LC fractions. BADGE.2HCl was found to be present in one canned coffee and five samples of corn, BFDGE.2HCl in four samples of canned tomatoes and in one canned corn. No sample was found which exceeded the 1 mg/kg limit of the EU for the BADGE chlorohydrins. However the highest concentration was found for the sum of BFDGE.2HCl anti BFDGE.HCl.H2O at a level of 1.5 mg/kg. A Beilstein test confirmed that all cans containing foods contaminated with BADGE.2HCl or BFDGE.2HCl had at lest one part coated with a PVC organosol.

Benzhydryl Compounds↗

Aberrant growth plate development in VDR/RXR gamma double null mutant mice.

VDR forms heterodimers with one of three RXRs, RXR alpha, RXR beta, and RXR gamma, and it is thought that RXR ligands can also modulate the trans-activation function of VDR/RXR heterodimers. In the present study we generated VDR/RXR gamma double null mutant mice to examine the convergent actions of vitamin D and vitamin A signaling and to explore the possibility of a functionally redundant VDR. Although RXR gamma(-/-) mice exhibited no overt abnormalities, VDR(-/-)/RXR gamma(-/-) mice appeared similar to VDR(-/-) mice, showing features typical of vitamin D-dependent rickets type II, including growth retardation, impaired bone formation, hypocalcemia, and alopecia. However, compared to VDR(-/-) mice, growth plate development in VDR(-/-)/RXR gamma(-/-) mutant mice was more severely impaired. Normalizing mineral ion homeostasis through dietary supplementation with high calcium and phosphorous effectively prevented rachitic abnormalities, except for disarranged growth plates in VDR(-/-)/RXR gamma(-/-) mutant mice, and alopecia in both VDR(-/-) and VDR(-/-)/RXR gamma(-/-) mutant mice. Histological analysis of VDR(-/-)/RXR gamma(-/-) growth plates revealed that development of the hypertrophic chondrocytes was selectively impaired. Thus, our findings indicated that the combined actions of VDR- and RXR gamma-mediated signals are essential for the normal development of growth plate chondrocytes, and raised the possibility that a functionally redundant VDR is present on chondrocytes as a heterodimer with RXR gamma.

Animals↗

Characterization of aryl alcohol oxidase produced by dye-decolorizing fungus, Geotrichum candidum Decl.

Aryl alcohol oxidase (AAO) produced by Geotrichum candidum Dec1 (Dec1), a newly isolated decolorizing fungus, was purified by ultrafiltration and by using diethylaminoethyl (DEAE) Sephacel, Butyl-Toyopearl and Mono-Q columns. H2O2 produced by concomitant AAO oxidation of veratryl alcohol (VA) to veratraldehyde was consumed by a peroxidase (DyP) purified from Dec1 culture, leading to the decolorization of a dye (in vitro). In the liquid culture of Dec1, the existence of H2O2 and veratraldehyde was confirmed during cultivation, when dye-decolorization and AAO activities were maintained. This indicates that VA produced by Dec1 was oxidized by AAO to veratraldehyde, generating H2O2, which supported dye-decolorizing activity of Decl in vivo. The prevention of polymerization of DyP oxidation products of a dye in the presence of AAO was shown.

Journal Article↗

Enhancement of the response to levodopa therapy after intrastriatal transplantation of autologous sympathetic neurons in patients with Parkinson disease.

OBJECT: There is growing evidence to indicate that tissue transplantation can potentially be a restorative neurosurgical treatment for patients with Parkinson disease (PD). In this study the authors investigated the clinical effect of unilateral intrastriatal grafting of autologous sympathetic neurons in patients with PD. METHODS: Four patients with PD who had been observed for 1 year after graft placement of autologous sympathetic neurons were selected for an analysis of the effect of that procedure. Sympathetic ganglion tissue was endoscopically excised from the thoracic sympathetic trunk and grafted into the unilateral caudate head and putamen of the PD patients. No changes were made in the patients' preoperative regimens of antiparkinsonian medications, and clinical evaluations were made principally according to those established by the Core Assessment Program for Intracerebral Transplantation Committee. Whereas the sympathetic neuron grafts failed to affect clinical scores reflecting the patients' motor performance, which was evaluated during either the "on" or "off' phases, the grafts significantly increased the duration of the levodopa-induced on period with consequent reduction in the percentage of time spent in the off phase. This beneficial effect may be explained by the results of the present in vitro experiment, which show that human sympathetic neurons have the ability to convert exogenous levodopa to dopamine and to store this synthesized dopamine. CONCLUSIONS: Sympathetic neuron autografts were found to improve performance status in patients with PD by reducing the time spent in the off phase. This clearly indicates that sympathetic ganglion tissue, the use of which involves few ethical issues, can be an efficacious donor source in cell transplantation therapy for PD. Further studies are needed to determine whether the grafts may provide long-lasting clinical benefits.

Antiparkinson Agents↗

[Analysis of main pigments and other ingredients in lac color product].

The contents of the main pigments and other ingredients in commercial lac color products were determined by HPLC using an RP-18 column with 0.1 mol/L citric acid buffer solution-methanol (16:5) as the mobile phase, and a photodiode array (PDA) detector set at 280 nm and 490 nm. The main pigments were confirmed by PDA and electrospray ionization mass spectrometry. Laccaic acids A, B, C and E were detected in all lac color products, and the ratio of content of laccaic acid A in all products was over 50%. The total contents of laccaic acids A, B and C in lac color food additive products and reagent products were 775-858, 797 and 779 g/kg, respectively. As for the contents of ingredients except pigments in commercial food additive products, the maximum moisture content was about 10%, and ether-soluble substances amounted to 0.5-3.6%.

Azo Compounds↗

The gamete fusion process is defective in eggs of Cd9-deficient mice.

The cell-surface molecule Cd9, a member of the transmembrane-4 superfamily, interacts with the integrin family and other membrane proteins. and is postulated to participate in cell migration and adhesion. Expression of Cd9 enhances membrane fusion between muscle cells and promotes viral infection in some cells. Fertilization also involves membrane fusion, between gametes. In mammals, the sperm binds to microvilli on the egg surface, and sperm-egg membrane fusion first occurs around the equatorial region of the sperm head12. The fused membrane is then disrupted, and the sperm nucleus as well as the cytoplasm is incorporated into the egg. Cd9 is expressed on the plasma membrane of the mouse egg, and an anti-Cd9 monoclonal antibody inhibits sperm-egg surface interactions. We generated Cd9 mice and found that homozygous mutant females were infertile. Sperm-egg binding was normal, but sperm-egg fusion was almost entirely inhibited in eggs from Cd9 females. Intracellular Ca2 oscillations, which signal fertilization, were absent in almost all mutant eggs; in rare cases, a response occurred after a long time period. In normal animals, Cd9 molecules were expressed on the egg microvilli and became densely concentrated at the sperm attachment site. Thus, our results show that Cd9 is important in the gamete fusion process at fertilization.

Animals↗

Interhemispheric neuroepithelial cyst associated with agenesis of the corpus callosum. A case report and review of the literature.

This report describes a neonatal case in whom a large interhemispheric cyst associated with agenesis of the corpus callosum was revealed by fetal ultrasonography and demonstrated by MRI to be multilobulated. Endoscopic fenestration of cysts was initially designed in view of the development of the patient's brain and surgical invasiveness. One year later, when motor paresis of the left arm and progressive enlargement of the cyst on MRI were revealed, open surgery was performed. The histological diagnosis was a neuroepithelial cyst with the feature of choroid plexus epithelia. The clinicopathological features of interhemispheric epithelial cysts associated with agenesis of the corpus callosum are reviewed in the light of differential diagnosis and therapeutic considerations.

Agenesis of Corpus Callosum↗