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Biomedical subjects

A Yanai

Publications and source records attributed to A Yanai.

At least 37 records · Page 2Linked to original sources
PubMed1997

ayk1, a novel mammalian gene related to Drosophila aurora centrosome separation kinase, is specifically expressed during meiosis.

A novel murine gene, designated ayk1, which encodes a putative serine/threonine kinase has been cloned and characterized. The predicted catalytic domain of the protein is highly similar to that of Drosophila aurora (62.9% identity), and to that of Saccharomyces Ipl1 (49.4% identity). All three proteins also have very basic calculated isoelectric points (higher than 10). aurora has been recently shown to be crucial for centrosome separation and chromosome segregation, while Ipl1 is essential for yeast viability and accurate chromosome segregation. The results of Northern analysis and in situ RNA localization support a similar role for ayk1. The gene is specifically expressed in meiotically active cells, and during spermatogenesis, ayk1 transcripts accumulate just before the first meiotic division. Much lower levels are found in mitotically active cells. We propose that Ayk1, aurora and Ipl1 belong to a distinct new subfamily of kinases. These results suggest that the pathways controlling chromosome segregation are evolutionary conserved, and that similar control mechanisms operate in mitosis and meiosis.

Amino Acid Sequence↗
PubMed1997

Characterization of detergent-insoluble complexes containing the cellular prion protein and its scrapie isoform.

Cells infected with prions contain both prion protein isoforms cellular prion protein (PrPC) and scrapie prion protein (PrPSc). PrPSc is formed posttranslationally through the pathological refolding of PrPC. In scrapie-infected ScN2a cells, the metabolism of both PrP isoforms involves cholesterol-dependent pathways. We show here that both PrPC and PrPSc are attached to Triton X-100-insoluble, low-density complexes or "rafts." These complexes are sensitive to saponin and thus probably contain cholesterol. This finding suggests that the transformation PrPC --> PrPSc occurs within rafts. It also reveals the existence of rafts in late compartments of the endocytic pathway, where most PrPSc resides. When Triton X-100 lysates of cells were incubated at 37 degrees C prior to density analysis, PrPC was still found in buoyant complexes, although it now failed to sediment at high speed. This property was shared by another glycophosphatidyl inositol protein, Thy-1, and also by the raft resident GM1. In one ScN2a clone and in the brain of a Syrian hamster with scrapie, Triton X-100 extraction at 37 degrees C permitted resolution of PrPC and PrPSc into two distinct peaks of different densities. This suggests that there are two populations of PrP-containing rafts and may permit isolation of PrPC-specific rafts from those containing PrPSc. Our findings reinforce the contention that rafts are involved in various aspects of PrP metabolism and in the "life cycle" of prions.

Animals↗
PubMed1997

Induction of apoptosis in a human hepatocellular carcinoma cell line by a neutralizing antibody to transforming growth factor-alpha.

A cell line derived from a Japanese man with hepatocellular carcinoma was established in culture and designated OCUH-16. The cell line has the morphological and chromosomal features of hepatocellular carcinoma cells and has a short doubling time (approximately 33 h). OCUH-16 cells were shown to express transforming growth factor-alpha (TGF-alpha) in addition to albumin, DNA polymerase-alpha, c-JUN, and the retinoblastoma gene product. Electron microscopy revealed TGF-alpha immunoreactivity associated with the cell membrane, but TGF-alpha was not detected in medium conditioned by OCUH-16 cells by enzyme-linked immunosorbent assay. Reverse transcription and polymerase chain reaction analysis revealed the presence of TGF-alpha messenger RNA in these cells. Culture of OCUH-16 cells in the presence of a neutralizing antibody to TGF-alpha inhibited cell proliferation and induced many cells to undergo apoptosis (programmed cell death). These observations suggest that endogenous TGF-alpha is necessary for OCUH-16 cell growth.

Antibodies, Monoclonal↗
PubMed1997

The three-square-flap method for reconstruction of minor syndactyly.

A three-square-flap procedure is described for surgical treatment of minor syndactyly. The average follow-up period in 58 cases (48 patients) was 2 years 4 months. In the three-square-flap method, the interdigital space is regarded as a cube and flaps are designed on each surface of the cube (dorsal side, interdigital surface, and volar side); the flap on the dorsal side forms the basal surface of the new interdigital portion. This technique is most suitable for reconstruction of minor three-dimensional contracture syndactyly. This method does not require skin grafting; the design is uncomplicated and easy to understand, and the operative procedure is simple.

Adolescent↗
PubMed1997

Huge pleomorphic adenoma of the upper retromolar area.

The case of a 41-year-old female is described wherein a minor salivary gland pleomorphic adenoma originating in the right retromolar area had extended into the infratemporal fossa and enlarged to 5 x 6 x 12 cm. The patient first became conscious of the mass as a slight swelling of the buccal mucosa when she was about 30 years of age, and the swelling since then had gradually gained in prominence. Preoperative computed tomography scan demonstrated a well-circumscribed mass occupying the right infratemporal fossa and medially displacing the pterygoid laminas. The mass was easily removed without much bleeding and no recurrence has been detected for 4 years. The incidence of pleomorphic adenoma originating in the retromolar area, the size of minor salivary gland pleomorphic adenomas at the time of diagnosis, and the treatment of choice are discussed.

Adenoma, Pleomorphic↗
PubMed1996

Ectrodactyly, ectodermal dysplasia, and cleft lip syndrome. Case report.

We describe five sporadic cases of the EEC syndrome (ectrodactyly, ectodermal dysplasia, and cleft lip). There are only a few reports of the syndrome being inherited in Japan. Two of the five patients had genitourinary anomalies and one mental retardation. Four of the five patients had clefts in the primary and secondary palate. All had deformities of the hands, polydactyly, syndactyly, and camptodactyly. Syndactyly could be a component of the syndrome.

Abnormalities, Multiple↗
PubMed1995

Expression of the retinoblastoma gene product in human hepatocellular carcinoma.

Using the mouse anti-human retinoblastoma gene product (pRB) monoclonal antibody, PMG3-245, pRB was detected immunohistocytochemically in human hepatocellular carcinoma (HCC) tissues and a human HCC cell line, designated OCUH-16, recently established in our laboratory. This antibody reacted with human pRB and yielded a single band of approximately 110 kd from cultured OCUH-16 cells. The granules that stained for pRB were found mostly in the HCC cell nuclei, with a few granules observed in the rough endoplasmic reticulum by electron microscopy. Most of the stained granules were located in the euchromatin-rich areas. The percentage of OCUH-16 cells that expressed pRB or DNA polymerase alpha (DNA-PA) decreased over time as the number of OCUH-16 cells increased. The number of HCC cells that stained for pRB in the biopsy specimens from 11 patients varied and pRB expression was well maintained in early and advanced HCC. The level of pRB expression did not correlate with the differentiation of HCC cells or the clinical prognosis. The expression of pRB statistically correlated with that of DNA-PA (P < .01; r = .92). Some sinusoidal cells also stained for pRB. These findings imply that large deletions in the pRB gene are rare in the initiation or promotion of HCC. The correlation between pRB and DNA-PA may suggest that stained pRB participates in the proliferation of both HCC and non-HCC cells.

Adult↗
PubMed1995

Reconstruction of scalp and cranium defect utilizing latissimus dorsi musculocutaneous and serratus anterior muscle free flaps with interpositional anastomosis of T-shaped flap artery: case report.

The use of a combination musculocutaneous free flap, consisting of a latissimus dorsi flap and a serratus anterior flap, for reconstruction of a large scalp and cranium defect is described. The recipient artery, the superficial temporal artery (STA), was anastomosed to the flap artery, without sacrificing blood flow, by means of a special technique: forming the end of the flap artery into a T shape and interposing it between the two stumps of the transected STA, because the STA was crucial for tissue adjacent to the defect. The flap vein was anastomosed to the external jugular vein with a vein graft. The extensive defect was immediately closed with sutures, and there were no remarkable complications.

Case Reports↗
PubMed1995

Prediction of informativeness for microsatellite markers among progeny of sires used for detection of economic trait loci in dairy cattle.

Individual loci affecting economic traits can be located using genetic linkage. Application of either daughter or granddaughter design requires determination of allele origin in the progeny. If only the sires and their progeny are genotyped, the paternal allele origin of progeny having the same genotype as the sire cannot be determined. The expected frequency of informative sons can be predicted for each sire and genetic marker from the allele frequencies in the population. The accuracy of a predictor of the frequency of informative progeny was tested on 103 grandsire x microsatellite combinations. Number of sons per grandsire varied from 24 to 129. Allele frequencies in the population were estimated by genotyping seven sires. The regression of the frequency of informative sons on the predicted frequency was 1.04 with a zero intercept model. Thus, considering the large number of genetic markers available for analysis, predicted informative frequency is a useful criterion for selection of genetic markers.

Animals↗
PubMed1995

High cervical chordoma--case report.

A 42-year-old male presented with a high cervical chordoma detected at an early stage and manifesting only as neck pains. Serial cervical roentgenograms over 8 years confirmed the slow growth character of this malignant tumor. Computed tomography and magnetic resonance imaging provided clear visualization of the tumor localized in the anterior aspect of the C-2 vertebral body. The tumor was totally removed through a transoral approach. Early diagnosis of vertebral chordoma is difficult due to the slow growth character and insidiousness of initial symptoms, but meticulous examination of serial roentgenograms, followed by neuroimaging, can achieve early detection of cervical chordoma.

Adult↗
PubMed1995

Hemihypoglossal-facial nerve anastomosis in treating unilateral facial palsy after acoustic neurinoma resection.

Eight patients underwent hemihypoglossal-facial nerve anastomosis (anastomosis of a split hypoglossal nerve to the facial nerve) for treatment of unilateral facial palsy. All patients previously had undergone resection of a large acoustic neurinoma and the facial nerve had been resected at that time. The interval between tumor resection and hemihypoglossal-facial nerve anastomosis ranged from 1 to 6 months, with an average of 2.1 months. Postoperative recovery of facial movement was good in all cases during an average follow-up period of 4.2 years. In all eight patients, the degree of hypoglossal nerve atrophy on the operated side was graded mild or moderate, but not severe. It was concluded that hemihypoglossal-facial nerve anastomosis results in good facial reanimation as long as the procedure is performed early after the onset of facial palsy and that this procedure may reduce the degree of hemiglossal atrophy in comparison with classic hypoglossal-facial nerve anastomosis.

Adult↗
PubMed1995

[Pharmacokinetics of 123I-iomazenil, a benzodiazepine receptor seeker].

The biodistribution, metabolism and excretion of 123I-iomazenil have been studied in rats, rabbits and humans following i.v. administration. In all the species, 123I-iomazenil was rapidly metabolized and more than 90% of the administrated radioactivity was excreted within the first 24 hr. Dominant metabolites were acid metabolite (R-COOH), glucuronide of the acid (R-COOH-Glc) and free iodide (I-) in rats and humans. On the other hand, R-COOH, oxidative metabolite (R'-CH2COOH) and I- were found in rabbits. Thus, the possible metabolic pathways of iomazenil were hydrolysis, oxidation, conjugation and deiodination. The radioactivity was excreted into both urine and feces in rats, while primary route of excretion in rabbits and humans was from the kidneys. At 3 hr after injection, more than 97% of the radioactivity in rat brain was found in the form of the parent compound. This result indicates that metabolites of 123I-iomazenil do not cross the blood-brain barrier.

Animals↗
PubMed1994

Mapping quantitative trait loci with DNA microsatellites in a commercial dairy cattle population.

Individual loci affecting economically important traits can be located using genetic linkage between quantitative trait loci and genetic markers. In the 'granddaughter' experimental design, heterozygous grandsires and their sons are genotyped for the genetic marker, while the quantitative trait records of the granddaughters are used for statistical analysis. Ten DNA microsatellite markers were used to look for associations with quantitative trait loci affecting milk production traits in seven Israeli Holstein grandsire families. At least 60% more grandsires were heterozygous, and 40% fewer individuals were discarded because of unknown paternal allele origin, as compared with diallelic markers. The effects of paternal alleles for locus D21S4 on kg milk and protein were significant (P < 0.025). The allele substitution effects for sire 783 were 283 kg milk and 5.7 kg protein. For both traits, progeny of sire 783 that inherited allele '18' had higher evaluations than progeny that inherited allele '21'. These results were verified by genotyping 151 of his daughters. Thus, the rate of genetic gain for protein production can be increased by selecting progeny of sire 783 carrying allele '18' at this locus.

Animals↗
PubMed1994

Immunohistochemical analysis of retinoblastoma gene product (pRB) expression in malignant and non-malignant liver diseases.

The retinoblastoma gene product is a nuclear phosphoprotein that undergoes cell cycle-dependent changes in its phosphorylation status. To analyze the expression of retinoblastoma gene product in the process of liver regeneration and the initiation of hepatocellular carcinoma, we studied immunohistochemically the expression of retinoblastoma gene product and DNA polymerase alpha (DPA) in 33 patients with various liver diseases. Only a few hepatocytes positive for retinoblastoma gene product were found in undamaged, nonregenerating liver tissues, whereas many hepatocytes positive for retinoblastoma gene product were detected in specimens of regenerating liver obtained from patients with acute or chronic liver diseases. Similarities were found between distribution patterns of hepatocytes positive for retinoblastoma gene product and those of hepatocytes positive for DPA, and a highly significant positive correlation was found between the number of hepatocyte nuclei stained for retinoblastoma gene product per 1000 nuclei examined (R-LI) and the number of hepatocyte nuclei stained for DPA per 1000 nuclei examined (D-LI) in tissues obtained from patients with nonmalignant liver disease. Hepatocellular carcinoma cells positive for DPA were detected in the 14 hepatocellular carcinoma specimens tested. In ten of these specimens, hepatocellular carcinoma cells positive for retinoblastoma gene product were found but not in the other four. For all hepatocellular carcinoma specimens, R-LI was proportional to D-LI. Thus in both nonmalignant and malignant liver, retinoblastoma gene product increased in proportion to proliferation of hepatocytes or hepatocellular carcinoma cells.

Adult↗
PubMed1993

Analysis of proliferating biliary epithelial cells in human liver disease using a monoclonal antibody against DNA polymerase alpha.

The proliferative activity and ultrastructural characteristics of proliferating biliary epithelial cells were analysed immunohistocytochemically in 39 biopsied liver specimens from patients with acute viral hepatitis, chronic hepatitis and liver cirrhosis using a monoclonal antibody against DNA polymerase alpha (DNA-PA). In acute viral hepatitis with perivenular confluent necrosis, proliferation of typical bile ducts was found frequently in portal areas. In chronic aggressive hepatitis and cirrhosis, ductular proliferation of both typical and atypical forms was found in enlarged portal and periportal areas and in confluent necrotic areas. The number of proliferating biliary epithelial cells that stained positive for DNA-PA was small. There were very few positively stained cells in atypical bile ducts in confluent necrotic areas of cirrhosis. Atypical bile ducts seen in chronic aggressive hepatitis, cirrhosis and acute hepatitis with confluent necrosis were positively stained for both cytokeratins 8 and 19. In cirrhosis, the number of stained biliary epithelial cells in typical bile ducts was larger than the number of such cells in atypical bile ducts (P < 0.01). By electron microscopy, the cells positively stained for DNA-PA were mostly so-called clear cells with irregular nuclei containing coarse nucleoplasm, and a few small cells with scanty cytoplasm and few organelles.

Adult↗
PubMed1993

Pharmacokinetic properties of recombinant feline interferon and its stimulatory effect on 2',5'-oligoadenylate synthetase activity in the cat.

The pharmacokinetic behavior of recombinant feline interferon produced in silkworm infected with recombinant baculovirus harboring cDNA coding for feline interferon was studied in vivo in cats. The decreasing profile of the serum interferon level after intravenous administration was fitted to a two-compartment model. The half-times of the first phase (distribution phase) and second phase (metabolic phase) were 5.0 +/- 0.5 min and 31 +/- 5 min, respectively. In the whole body autoradiogram, at 15 min after the administration, the highest radioactivity was observed in urine in the bladder, and predominant radioactivity in the kidneys, liver, thyroid gland and spleen. Almost no radioactivity was detected in the brain or fat. Three hr after administration, the highest radioactivity was recorded in the thyroid gland, urine in the bladder, intestinal contents, and gastric mucous membrane. The data obtained in this study suggest that recombinant feline interferon has similar pharmacokinetic properties to human interferons and that it is distributed primarily in the liver and kidneys, is catabolized rapidly mainly in the kidneys, and is excreted in the urine without residual accumulation in the body. It was confirmed that 2',5'-oligoadenylate synthetase activity was increased by the interferon in vivo for 3 days after an intravenous bolus injection in cats.

2',5'-Oligoadenylate Synthetase↗