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Biomedical subjects

M Oshiro

Publications and source records attributed to M Oshiro.

At least 19 recordsLinked to original sources
PubMed2006

Erythrocyte glucose-6-phosphate dehydrogenase from Brazilian opossum Didelphis marsupialis.

In a comparative study of erythrocyte metabolism of vertebrates, the specific activity of glucose-6-phosphate dehydrogenase (G6PD) of the Brazilian opossum Didelphis marsupialis in a hemolysate was shown to be high, 207 +/- 38 IU g-1 Hb-1 min-1 at 37 degrees C, compared to the human erythrocyte activity of 12 +/- 2 IU g-1 Hb-1 min-1 at 37 degrees C. The apparent high specific activity of the mixture led us to investigate the physicochemical properties of the opossum enzyme. We report that reduced glutathione (GSH) in the erythrocytes was only 50% higher than in human erythrocytes, a value lower than expected from the high G6PD activity since GSH is maintained in a reduced state by G6PD activity. The molecular mass, determined by G-200 Sephadex column chromatography at pH 8.0, was 265 kDa, which is essentially the same as that of human G6PD (260 kDa). The Michaelis-Menten constants (Km: 55 microM) for glucose-6-phosphate and nicotinamide adenine dinucleotide phosphate (Km: 3.3 microM) were similar to those of the human enzyme (Km: 50-70 and Km: 2.9-4.4, respectively). A 450-fold purification of the opossum enzyme was achieved and the specific activity of the purified enzyme, 90 IU/mg protein, was actually lower than the 150 IU/mg protein observed for human G6PD. We conclude that G6PD after purification from the hemolysate of D. marsupialis does not have a high specific activity. Thus, it is quite probable that the red cell hyperactivity reported may be explained by increased synthesis of G6PD molecules per unit of hemoglobin or to reduced inactivation in the RBC hemolysate.

Animals↗
PubMed2004

Sequence variation of the cytochrome b gene of various human infecting members of the genus Leishmania and their phylogeny.

The Cytochrome b (Cyt b) gene has proved to be useful for identification and classification of many mammals and plants. In order to evaluate the utility of this gene for discrimination of Leishmania parasites as well as for exploring their phylogenetic relationships, we determined the nucleotide sequences of the Cyt b gene from 13 human-infecting Leishmania species (14 strains) from the New and Old Worlds. The Cyt b genes, approximately 1080 base pairs, were found to be A/T rich, and their 5' terminal-editing regions were highly conserved. The nucleotide sequence variation among them was enough to discriminate parasite species; 245 nucleotide positions were polymorphic and 190 positions were parsimony informative. The phylogenetic relationships based on this gene, showed good agreement with the classification of Lainson & Shaw (1987) except for the inclusion of L. (L.) major in the L. (L.) tropica complex and the placement of L. tarentolae in another genus. These data show that the Cyt b gene is useful for phylogenetic study of Leishmania parasites.

Amino Acid Sequence↗
PubMed2001

Immunohistochemical localization of heparan sulfate proteoglycan in human gastrointestinal tract.

Heparan sulfate proteoglycans (HS-PGs) are associated with important cell functions, for example, cell motility, cell adhesion, and oncogenesis. We examined the localization of HS-PGs in normal and carcinoma tissues of the gastrointestinal tract to help elucidate their roles in these organs. Fresh surgical materials from 134 patients with carcinoma of the stomach or large intestine and 26 patients with various diseases of the small intestine were immunostained after fixation with 10E4 (an antibody against the HS of HS-PG) as a primary antibody. Immunoelectron microscopy (immunogold method) was also performed. The basolateral surfaces of normal tissues of the large and small intestines were strongly stained with antibody confirmed by electron microscopy. In the stomach, lesions with intestinal metaplasia showed the same staining as the intestines, although normal gastric tissue showed staining only in some parts of the basal layer of fundic and pyloric glands. Carcinoma tissues in all cases examined showed staining with antibody. Better results were obtained after fixation in acetic alcohol or zinc-containing solutions than in ordinary formalin. These characteristic localizations of HS-PG in intestines and stomachs suggest that this kind of HS-PG staining could be a hallmark characteristic of the intestine.

Adult↗
PubMed2001

Plasma and erythrocyte levels of trace elements and related antioxidant enzyme activities in low-birthweight infants during the early postnatal period.

UNLABELLED: To discover the relationship between antioxidant enzyme activities and trace elements in low-birthweight infants during the early postnatal period, we analysed catalase (CAT), CuZn-superoxide dismutase (CuZn-SOD) and glutathione peroxidase (GSH-Px) activities in erythrocytes. and compared them with Fe, Cu. Zn and Se levels in plasma, and Cu, Zn and Se levels in erythrocytes until 16 wk after birth. Thirteen low-birthweight infants whose mean birthweight and gestation were 1520 +/- 293 g and 32.0 +/- 2.8 wk were enrolled in this study. All infants were without chronic complications, well nourished, and predominantly fed standard formula or preterm formula based on cow's milk, commercially available in Japan. Cu and Zn levels in erythrocytes did not decline after birth, in contrast to a temporal decrease in plasma Zn. Erythrocyte CAT activity was significantly higher at 16 wk than that at birth or 4 wk of age. Erythrocyte CuZn-SOD activity did not change throughout the study period. Only Se in plasma and erythrocytes decreased remarkably after birth, which resulted in a significant decline in erythrocyte GSH-Px activity at 8 and 16 wk (11.2 +/- 2.0 and 11.0 +/- 1.1 U/g Hb) compared to that at birth (12.4 +/- 2.1 U/g Hb). CONCLUSION: During the early postnatal period. erythrocyte CAT and CuZn-SOD activities did not decrease in formula-fed, low-birthweight infants. Japanese commercial formula not supplemented with Se, however, caused postnatal plasma and erythrocyte Se deficiency and a concomitant decline in erythrocyte GSH-Px activity in the same subjects.

Catalase↗
PubMed2001

Detection of species of the subgenus Leishmania parasites using polymerase chain reaction and southern blotting.

In this study, an attempt was made to identify different Leishmania species by polymerase chain reaction (PCR). Fourteen Leishmania strains from stock were tested by PCR and Southern blotting. A pair of primers were employed that anneal to the kinetoplast DNA sequence conserved among subgenus Leishmania. Of the 14 Leishmania strains used in this study, six showed strong bands of approximately 170 bp, and all the positive strains belonged to the species of the subgenus Leishmania viz., Leishmania (Leishmania) garnhami, L. (L.) amazonensis, L. (L.) pifanoi, L. (L.) mexicana, L. (L.) chagasi, and L. (L.) major All the species belonging to the subgenus Viannia used in this study were negative by PCR. These results suggest that the primer pair may be useful for identification of the species belonging to the subgenus Leishmania of the New World as well as to distinguish subgenus Leishmania from subgenus Viannia.

Animals↗
PubMed2001

Anterior capsular contraction after cataract surgery in eyes of diabetic patients.

AIM: To investigate change in the area of anterior capsular opening (ACO) after cataract surgery and its relation to the degree of postoperative anterior inflammation in patients with diabetes mellitus (DM). METHODS: 31 eyes of 31 patients with DM and 30 eyes of 30 normal controls scheduled to undergo cataract surgery were examined prospectively. The area of ACO was measured with an anterior eye segment analysis system (EAS-1000) on the day following surgery and 3, 6, and 12 months after surgery. Comparative analyses were made on the area of ACO relative to the presence of DM and diabetic retinopathy (DR). The percentage reduction of area of ACO was calculated from values 1 day and 12 months after surgery, and multiple regression analysis was performed on the presence of DM, patient age, ACO area on the first postoperative day, and aqueous flare intensity 1 day and 12 months after surgery. RESULTS: The area was significantly smaller in the DM group at 3 (p=0.015, Student's t test), 6 (p=0.011), and 12 (p=0.010) months postoperatively. Patients having DR showed significantly smaller ACO area than the non-DR group 3 (p=0.039), 6 (p=0.033), and 12 (p=0.028) months after surgery. Multiple regression analysis revealed that presence of DM (p=0.003) and aqueous flare intensity 12 months after surgery (p=0.039) significantly correlated with the percentage reduction of area of ACO. Age, ACO area at 1 day postoperatively, and aqueous flare intensity immediately after surgery were not relevant to ACO contraction. CONCLUSIONS: Anterior capsular contraction after cataract surgery was greater in eyes of DM patients, especially in those with DR and increased permeability of the blood-aqueous barrier.

Aged↗
PubMed2001

Inhibition of STAT3 signaling leads to apoptosis of leukemic large granular lymphocytes and decreased Mcl-1 expression.

Large granular lymphocyte (LGL) leukemia is characterized by the expansion of antigen-activated cytotoxic T lymphocytes. These leukemic cells are resistant to Fas-mediated apoptosis despite expressing high levels of Fas. We found that leukemic LGL from 19 patients displayed high levels of activated STAT3. Treatment of leukemic LGL with the JAK-selective tyrosine kinase inhibitor AG-490 induced apoptosis with a corresponding decrease in STAT-DNA binding activity. Moreover, using an antisense oligonucleotide approach to diminish STAT3 expression, we found that Fas sensitivity was restored in leukemic LGL. AG-490-induced apoptosis in leukemic LGL was independent of Bcl-xL or Bcl-2 expression. However, we found that the Bcl-2-family protein Mcl-1 was significantly reduced by AG-490 treatment. Activated STAT3 was shown to bind an SIE-related element in the murine mcl-1 promoter. Using a luciferase reporter assay, we demonstrated that v-src overexpression in NIH3T3 induced STAT3-dependent transcriptional activity from the mcl-1 promoter and increased endogenous Mcl-1 protein levels. We conclude that STAT3 activation contributed to accumulation of the leukemic LGL clones. These findings suggest that investigation should focus on novel strategies targeting STAT3 in the treatment of LGL leukemia.

Apoptosis↗
PubMed2000

A possible interaction of thioredoxin with VDUP1 in HeLa cells detected in a yeast two-hybrid system.

Human thioredoxin (hTrx), a small ubiquitous protein with strong reducing potential, has multiple biological functions, including signal transduction and regulation of the activity of transcription factors. hTrx expression is enhanced in HPV-transformed cancer cells; however, the role of hTrx in the malignant cells is not fully understood. We employed a yeast two-hybrid system to search for proteins that bind to hTrx in HeLa cells, a type of HPV-transformed human cervical cancer cell. In a screen of 1.62 x 10(6) yeast cotransformed with a HeLa cDNA library and an hTrx vector, 13 clones were identified as candidates for hTrx-binding proteins. Among them, 3 clones were found to code in frame for the carboxyl-terminal portion of VDUP1 protein, lacking at most the first 155 residues from the start codon. A reconstructed clone carrying the full-length VDUP1 coding sequence also showed the ability to bind to an hTrx fusion protein. Loss of interaction between VDUP1 and hTrx was observed either when two cysteines (Cys 32 and 35) in hTrx were substituted by serines or when the deletion in VDUP1 was extended from amino acid position 155 to 225 or beyond. The 71-mer peptide fragment (position 155-225) of VDUP-1 alone did not bind to hTrx.

Carrier Proteins↗
PubMed2000

A comparison between low-flow leak test and oxygen flush leak test.

PURPOSE: The clinical efficacy of two methods of preanesthetic leak test,namely the oxygen flush leak test (OFLT) and the low-flow leak test (LFLT), was compared regarding their ability to detect leakage in the anesthesia circuit and their accuracy. METHODS: Examinees comprised 16 staff anesthesiologists and 7 physicians undergoing anesthesia training at our institution. They performed the two leak tests on anesthesia machines with some intentional leaks (0.1-1.0 l.min(-1)). The leakage detection rates (LDR) were analyzed by the chi(2)-test. The ability to detect leaks was measured by recording how many leaks were detected by 50% (LDR(50)) and 95% (LDR(95)) of the examinees. RESULTS: The LDRs in the two tests were significantly different (chi(2)- analysis, P < 0.0001). Both LDR(50) and LDR(95) for the LFLT (0.23 and 0.41 l.min(-1), respectively) were smaller than the values for the OFLT (0.37 and 0.82 l.min(-1), respectively). The sensitivity and specificity of the LFLT (0.97 and 0.84, respectively) were higher than those of the OFLT (0.78 and 0.80, respectively). CONCLUSION: The LFLT was found to be superior to the OFLT regarding leak detection and reliability. We therefore recommend the LFLT for preanesthetic leak testing.

Journal Article↗
PubMed2000

Association of human papillomavirus type 6 with a verruciform xanthoma.

We report a case of verruciform xanthoma (VX) associated with human papillomavirus (HPV) in a 67-year-old male. The patient had a pale-reddish, granular and verrucous tumor on the right side of his scrotum for four years. Histopathologic examination showed typical features of VX. HPV was detected by immunohistochemistry, electron microscopy, and PCR examinations. Ultrastructural examination revealed virus-like particles of 40-50 nm in the nucleus of the upper epidermal keratinocytes. HPV type 6a DNA was detected in lesional tissue by polymerase chain reaction and sequence analysis. To the best of our knowledge, this is the first case report of VX associated with HPV.

Aged↗
PubMed2000

Increased fetal hemoglobin levels in patients infected with human immunodeficiency virus (HIV1/2).

Fetal hemoglobin was measured in HIV1/2 patients under treatment with combined therapy (zidovudine and a protease inhibitor). A total of 143 patients and 103 normal individuals were investigated by the quantitative method of Betke and the semi-quantitative acid elution method of Kleihauer. In the normal person, hemoglobin F makes up less than 1% and an increase higher than 1.5% was observed in 21.4% of HIV patients by the method of Betke and in 24.8% of HIV-infected patients by the method of Kleihauer. The quantitative biochemical method of Betke showed that the populations were significantly different (two-tailed Mann-Whitney test). The reason for this hemoglobin F increase might be ascribed to the effect of zidovudine or to direct viral action on gamma chain expression. The finding of a higher F cell frequency indicated by the method of Kleihauer rather suggests that there is an increased F cell clone proliferation rather than an increase in hemoglobin F level in every cell.

Anti-HIV Agents↗
PubMed1999

Alteration of mRNA levels of delta-aminolevulinic acid synthase, ferrochelatase and heme oxygenase-1 in griseofulvin induced protoporphyria mice.

Human erythropoietic protoporphyria (EPP) is an inherited disorder of porphyrin metabolism and its experimental murine model can be produced by treatment with griseofulvin (GF). We investigated the alteration of mRNA expression in ferrochelatase (FeC), delta-aminolevulinic acid synthase (ALAS) and heme oxygenase-1 (HO-1) in liver, skin and peripheral blood cells of GF-treated mice. In liver, ALAS mRNA was enhanced dramatically by GF administration, in accord with thesis that the expression of ALAS is regulated by feedback mechanism. The expression of HO-1 mRNA increased most rapidly and drastically in liver, however its mechanism of regulation may be different from that of ALAS mRNA. The level of FeC mRNA in liver was less affected with GF treatment. Our results indicate that the inhibition of FeC by GF administration might occur primarily at post-transcriptional level. Similar effects were observed in the ALAS and HO-1 mRNA expression in peripheral blood cells, 2-fold increase in the ALAS mRNA and increase from undetectable level to detectable level in the HO-1 mRNA. In skin of GF-treated mice, average increases of 1.3-fold in the ALAS mRNA and 1.6-fold in the HO-1 mRNA were statistically insignificant. The FeC mRNA level was not altered in peripheral blood or in skin of GF-treated mice. The present study indicates that the molecular analysis is practicable in skin and peripheral blood. In further study, this model could contribute to investigate the pathogenesis of clinical manifestation including possibly cutaneous changes in EPP.

5-Aminolevulinate Synthetase↗
PubMed1999

Twin-to-twin transfusion syndrome with hydrops: a retrospective analysis of ten cases.

We retrospectively studied 10 cases of twin-to-twin transfusion syndrome (TTTS) with fetal hydrops. TTTS was diagnosed sonographically between the 17-31 weeks of gestation. All twins were delivered by emergency cesarean section because of cardiac decompensation of one or both fetuses. The mean (+/-SD) age at diagnosis was 26.1 +/- 4.5 and the mean age at delivery was 28.8 +/- 2.0 weeks. Gestational age at birth was similar in survivors and nonsurvivors. However, surviving infants were diagnosed later in gestation (23.6 +/- 4.8 vs. 28.7 +/- 1.9 weeks; p < 0.01); and gestational age at appearance of hydrops were later in survivors (26.1 +/- 3.2 vs. 29.2 +/- 2.4 weeks; p < 0.05). Overall survival rate was 50% (10 of 20 infants). All survivors were delivered within 3 days after the appearance of fetal hydropic changes. Extrauterine treatment in earlier stages of TTTS might improve the outcome. Nevertheless, more aggressive intrauterine treatment should be considered in the most severe cases of TTTS developing before 24-25 weeks' gestation.

Cesarean Section↗
PubMed1999

Detection of human papilloma virus type 56 in extragenital Bowen's disease.

A case of Bowen's disease arising on the medial part of the first metatarsal bone of an 81-year-old Japanese woman is described. Histopathologically, proliferation of atypical cells was found throughout the epidermis. Electronmicroscopy revealed virus particles 40-50 nm in diameter in the nuclei of tumour cells at the granular cells just on or below the horny layer. Positive bands were obtained by polymerase chain reaction using a consensus primer of human papilloma virus L1 portion. Sequencing analysis of the amplified DNA revealed the same base sequences and homology as human papilloma virus 56. To the best of our knowledge, this case is the first report in which human papilloma virus 56 was found in a case of extragenital Bowen's disease. We consider it important to understand that human papilloma virus 56, often found in cervical lesions, can be detected in extragenital Bowen's diseases.

Aged↗
PubMed1999

Detection of human papilloma virus type 58 in a case of a perianal Bowen's disease coexistent with adult T-cell leukemia.

A case of Bowen's disease (BD) that appeared in the perianal region of a 65-year-old Japanese woman coexistent with chronic adult T cell leukemia (ATL) is described. Histopathological findings revealed that irregularly arranged tumor cells with atypical nuclei throughout the epidermis, which itself disclosed hyperkeratosis, dyskeratotic cells, and clumping cells. Positive staining for HPV antigens was immunohistochemically seen in several nuclei of the tumor cells. Electron microscopic study of the tumor tissue disclosed virus particles of about 50 nm in diameter form the squamous cells. A positive band at 256 bp was obtained by PCR using HPV-L1 primer. The amplified DNA by L1 primer completely corresponded to that of HPV-58.

Aged↗