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H Ozasa

Publications and source records attributed to H Ozasa.

At least 73 records · Page 4Linked to original sources
PubMed1988

A reappraisal of the subunit molecular mass of chicken liver cytosol 5'-nucleotidase.

The subunit molecular mass of chicken liver cytosol 5'-nucleotidase was earlier reported to be 51 kDa upon sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis (Naito, Y. and Tsushima, K. (1976) Biochim. Biophys. Acta 438, 159-168). By immunoblot analyses after SDS-gel electrophoresis, however, a fraction from the liver homogenized in the presence of leupeptin showed multiple bands with molecular masses around 57 kDa, and SDS-extracted proteins directly from the liver exhibited a single 70 kDa component. These results indicate that the 51 kDa peptide observed in the cytosol 5'-nucleotidase preparation might, in fact, be a proteolytic artifact.

5'-Nucleotidase↗
PubMed1988

A dynamic test of hormonal sensitivity of gynecologic malignancy by use of an antiestrogen, tamoxifen.

To assess the hormonal sensitivity of tumors, progestin receptor levels in the tumor were monitored before and after tamoxifen, 40 mg/day for 7 days in patients with various gynecologic malignancies. Tamoxifen induced progestin receptors in two of eight-cases of endometrial cancer, four of eight cases of cervical epidermoid cancer, and two of seven cases of cervical adenocarcinoma. Induction of progestin receptors did not occur in one case of uterine mixed müllerian tumor and there were no measured progestin receptors after tamoxifen treatment in three cases of ovarian cancer and in one case of benign ovarian tumor. Because induction of progestin receptors is the best-documented response of estrogen target cells to estrogenic stimuli, this induction of progestin receptor with tamoxifen may be considered to indicate the estrogen sensitivity of a tumor. Further study is warranted to determine whether hormonal sensitivity assessed by the use of tamoxifen might serve to select tumors likely to respond to hormonal therapy.

Adult↗
PubMed1988

Adenomyosis: diagnosis with MR imaging.

Magnetic resonance (MR) imaging characteristics of adenomyosis were studied in eight women (aged 37-49 years) who underwent hysterectomy, and detailed radiologic/pathologic correlation was conducted in all cases. Adenomyosis produced diffuse and smooth uterine enlargement. The extent of the lesion was clearly identified on images obtained with long repetition time and long echo time; a diffuse, low-intensity area accompanied by tiny high-intensity spots was seen subjacent to the endometrium. The area appeared as a localized or diffuse thickening of the junctional zone because it was often isointense with this zone. Pathologic examination confirmed that the extent of adenomyosis correlated well with the low-intensity region on MR images and that both hemorrhagic areas and nonbleeding endometrial tissue corresponded to the high-intensity spots. The lesion consisted of distorted and compacted smooth muscle cells, but microscopic studies failed to explain the definitive difference in intensity between areas of adenomyosis and myometrium.

Adult↗
PubMed1988

Immunocytochemical localization of cytosol 5'-nucleotidase in chicken liver.

We investigated the localization of cytosol 5'-nucleotidase in chicken liver by use of a pre-embedding immunoenzyme technique. Cytosol 5'-nucleotidase was purified from chicken liver and a monospecific antibody to this enzyme was raised in a rabbit. Fab fragments of the antibody were conjugated with horseradish peroxidase. Tissue sections of the fixed chicken liver were incubated with the peroxidase-Fab fragments, followed by DAB reaction for peroxidase. By light microscopy, dark-brown staining was present in the cytoplasm of parenchymal cells, Kupffer cells, and endothelial cells. The latter two types of cells were stained more strongly than the former. By electron microscopy, reaction deposits were present in the cytoplasmic matrix but not in cell organelles, such as mitochondria, endoplasmic reticulum, and peroxisomes, or in nuclei. In control sections incubated with peroxidase-conjugated Fab fragments from non-immunized rabbit, no specific reaction was noted. The results indicate that cytosol 5'-nucleotidase is contained more in the sinus-lining cells and less in the parenchymal cells, and that the enzyme is present in the cytoplasmic matrix of these cells.

5'-Nucleotidase↗
PubMed1988

Abnormal polyamine metabolism in hypertensive cardiac hypertrophy.

In order to assess myocardial hypertrophic activity during the process of hypertensive cardiac hypertrophy in the presence and absence of treatment with anti-hypertensive agents, we analyzed myocardial polyamine concentrations in spontaneous hypertensive (SHR) rats and control rats of Wistar Kyoto (WKY) strain. The anti-hypertensive agents studied were diltiazem, hydralazine and captopril, each of which was administered for 5 weeks. In comparison with WKY rats, SHR rats showed elevated blood pressure and enlarged hearts with higher myocardial spermidine concentration. Although blood pressure was lowered in the diltiazem-treated SHR rats, heart weight and myocardial spermidine concentration increased as in untreated SHR rats. In the hydralazine-treated group increases in both blood pressure and myocardial spermidine concentration were suppressed, while an increase in heart weight was not. In the captopril-treated group, increases in blood pressure, heart weight and spermidine concentration were all suppressed. Since spermidine level appears to be a sensitive indicator of hypertrophic activity in the heart, this study suggests that captopril exerts an inhibitory effect on hypertensive cardiac hypertrophy whereas diltiazem does not. It also suggests that hypertrophy may reach a certain plateau level earlier in the hydralazine-treated animals than in others.

Animals↗
PubMed1988

Diastolic left ventricular function in normal children: the maximal positive dD/dt compared with the E/A ratio of mitral flow pattern.

The normal values for left ventricular diastolic function in children are influenced by numerous factors. As an index of this function, the maximum velocity of left ventricular internal dimension expansion (+ max dD/dt) was calculated from M-mode echocardiography for 33 normal persons who ranged in age from seven days to 18 years. This index showed a linear correlation with left ventricular end-diastolic dimension in the resting state. This index was compared with the E/A ratio which is ordinarily used as the diastolic functional index for children. Considering changes in physical development during childhood, both indices showed similar trends in relation to body surface area. The E/A ratio was strongly influenced by heart rate, but + max dD/dt was not. This was the major difference between two indices.

Adolescent↗
PubMed1987

Molecular cloning and nucleotide sequence of cDNA encoding the entire precursor of rat liver medium chain acyl coenzyme A dehydrogenase.

cDNA encoding the precursor of rat liver medium chain acyl-CoA dehydrogenase (EC 1.3.99.3) was cloned and sequenced. The longest cDNA insert isolated was 1866 bases in length. This cDNA encodes the entire protein of 421-amino acids including a 25-amino acid leader peptide and a 396-amino acid mature polypeptide. The identity of the medium chain acyl-CoA dehydrogenase clone was confirmed by matching the amino acid sequence predicted from the cDNA to the NH2-terminal and nine internal tryptic peptide sequences derived from pure rat liver medium chain acyl-CoA dehydrogenase. The calculated molecular masses of the precursor medium chain acyl-CoA dehydrogenase, the mature medium chain acyl-CoA dehydrogenase, and the leader peptide are 46,600, 43,700, and 2,900 daltons, respectively. The leader peptide contains five basic amino acids and only one acidic amino acid; thus, it is positively charged, overall. Cysteine residues are unevenly distributed in the mature portion of the protein; five of six are found within the NH2-terminal half of the polypeptide. Comparison of medium chain acyl-CoA dehydrogenase sequence to other flavoproteins and enzymes which act on coenzyme A ester substrates did not lead to unambiguous identification of a possible FAD-binding site nor a coenzyme A-binding domain. The sequencing of other homologous acyl-CoA dehydrogenases will be informative in this regard.

Acyl-CoA Dehydrogenase↗
PubMed1987

Induction of follicular growth in the squirrel monkey (Saimiri sciureus): enhanced recovery of mature ova for fertilization in vitro.

In order to improve the rate of recovery of mature ova over those previously reported, we evaluated a new hormonal regimen for induction of follicular growth in the squirrel monkey. This regimen, which consisted of 50 IU pregnant mare's serum (PMS) per day for 4 days followed by 50 IU PMS and 250 IU human chorionic gonadotropin (hCG) on the 5th day, gave an average yield of 2.3 mature ova per animal from 14 experiments involving 11 animals. Ova were recovered through laparotomy or laparoscopy 18 h after PMS and hCG. This number reached 3.3 per animal when ova matured in vitro were included. The fertilization rate was significantly higher for ova matured in vivo (44%) than for in vitro-matured ova (7%) (P less than 0.05), showing the importance of recovering mature ova for successful fertilization in vitro. In agreement with previous observations, a seasonal pattern was noted for the response of animals to induction of follicular development, with a reduction in response occurring during a summer period from July to September. Our observations also suggest the occurrence of immunologic problems associated with the use of PMS in the squirrel monkey.

Animals↗
PubMed1987

Progesterone increases serum CA-125 in endometriosis.

Serum level of CA-125 was monitored up to 48 hours after injection of 125 mg P-in-oil into patients with or without endometriosis in the follicular phase of their menstrual cycle. Circulating CA-125 levels remained unchanged at around 5 U/ml during the observation period in patients without endometriosis; however, a significant elevation was observed at 30 hours after injection in those patients with endometriosis (from 19.6 U/ml before injection to 30.0 U/ml at 30 hours after injection, P less than 0.05).

17 alpha-Hydroxyprogesterone Caproate↗
PubMed1987

Endometrial cysts of the ovary: MR imaging.

Magnetic resonance (MR) images of 15 cases of ovarian endometrial cyst were reviewed. With a high-field-strength (1.5-T) MR imager, T1- and T2-weighted images were obtained in axial and sagittal planes, with 5-mm section thickness. MR findings highly suggestive of an endometrial cyst included adhesions to the surrounding organs (e.g., loss of clear margin of the uterine body and tethered appearance of the rectum); a distinct low-intensity zone surrounding a cyst loculus on both T1- and T2-weighted images produced by a thick fibrous capsule; loculus contents with short T1 and long T2 values, attributed to hemorrhagic fluid; and prominent low intensity (shading) within a loculus on T2-weighted images, the mechanism of which is yet to be determined.

Adult↗
PubMed1987

Ovarian cystic teratomas: MR imaging.

Magnetic resonance (MR) imaging characteristics of ovarian cystic teratomas were evaluated in 18 patients with 23 surgically proved tumors. The fat within the tumor demonstrated characteristic intensity similar to that of subcutaneous fat and a pathognomic pattern of chemical shift artifact that helped differentiate ovarian cystic teratomas from endometrial cysts. In addition to fat, MR images of ovarian cystic teratomas had several other characteristics that allowed confident diagnosis, including gravity-dependent layering or floating debris, palm tree-like protrusions or rounded nodules (dermoid plugs), and, occasionally fat-fluid levels and globular calcification. MR images were diagnostic in 20 tumors and were able to depict a tumor measuring 2 cm in diameter. MR imaging appears to be valuable in problematic cases in which other modalities are not diagnostic.

Adolescent↗
PubMed1987

Vaginal agenesis: classification by MR imaging.

Vaginal agenesis was studied by magnetic resonance (MR) imaging lin a 15-year-old girl, a 19-year-old woman, and a 21-year-old woman. In each case MR studies demonstrated the presence or absence of a normal cervix and functioning endometrium. This information was useful in planning surgical management. MR imaging assisted in the classification of the abnormality by noninvasively demonstrating the details of pelvic anatomy-and the uterine morphologic characteristics.

Adolescent↗
PubMed1986

Regulation of rat heart cytosol 5'-nucleotidase by adenylate energy charge.

A 5'-nucleotidase (EC 3.1.3.5) was highly purified from the soluble fraction of rat heart. The preparation appeared homogeneous by the criterion of polyacrylamide-gel electrophoresis. The enzyme was activated by ATP and ADP, and inhibited by Pi. When AMP was used as substrate, the velocity/substrate-concentration plot was sigmoidal. ATP or ADP changed the plot to hyperbolic and decreased S0.5. Pi increased both the sigmoidicity of the plot and S0.5. When IMP was used as substrate, the velocity/substrate plot was hyperbolic. ATP or ADP decreased Km and increased V. Pi changed the plot to sigmoidal and increased S0.5. Within the range of adenylate energy charge observed in surviving mammalian cells (0.7-0.9), the rate of AMP-hydrolysing activity catalysed by the 5'-nucleotidase increased sharply with decreasing energy charge. The highest activity was observed at an energy-charge value of about 0.6. The response was also observed in the presence of Pi. No change in IMP-hydrolysing activity was observed in the physiological range of adenylate energy charge, but in the presence of Pi the activity gradually increased with increasing energy charge. These results suggest the possibility that this enzyme participates in production of adenosine, a vasodilator, during hypoxia and in removal of IMP, which accumulates during the hypoxia, in the heart.

5'-Nucleotidase↗
PubMed1986

Diagnostic capability of ultrasound versus CT for clinically suspected ovarian mass with emphasis on detection of adhesions.

Diagnostic capability was compared prospectively between ultrasound and CT using 25 consecutive cases of clinically suspected ovarian mass, which were found postoperatively to be comprised of 12 cases of ovarian neoplasm (of which 7 were malignant). 5 cases of endometriotic cyst, and 8 cases of nonovarian tumors including 4 cases of abscess. Accuracy for the histologic diagnosis with ultrasound and CT was 56 and 84%, respectively (P less than 0.05). With respect to discrimination of cystadenoma from cystadenocarcinoma, detection of intraperitoneal seedings, of paraaortic lymph node metastasis, and of ascites, either of the two imaging modalities was comparable to the other in their proficiency. In contrast to ultrasound, which permitted evaluation of adhesions to the uterus only in selected cases and hence was of limited use in this respect, CT was proficient in predicting the presence or absence of adhesions around the mass involving the uterus as well as other adjoining structures. The fact that CT is competent in detecting adhesions adds further value to CT as a powerful tool for the preoperative investigation of pelvic mass.

Diagnosis, Differential↗
PubMed1986

Uterine cervical cancer: assessment with high-field MR imaging.

Nineteen patients with histologically proved cervical carcinoma were evaluated with magnetic resonance (MR) imaging. Clinical, MR, and surgical findings were compared to determine accuracy and clinical usefulness of MR in demonstrating mass and extent of disease. MR imaging enabled clear differentiation of corpus uteri, cervix, vagina, uterine ligaments, and tumor. Tumor was demonstrated as a high-intensity mass deforming the low-intensity cervix; the low background intensity of normal structures provided high contrast to the mass. MR imaging accurately demonstrated the tumor in all ten patients with locally advanced cervical carcinoma and showed a normal cervix in nine patients with early cancer. On sagittal images, the shape of corpus uteri, cervix, and vagina, and their relationship to the mass were clearly assessed, with their long axes usually in a single plane. On axial images, assessment of parametrial tumor extension was facilitated by clear definition of the low-intensity cervix and uterine ligaments. Although more study is needed to determine the accuracy of MR in staging, MR is a promising method in evaluating cervical carcinoma.

Adult↗