Search PubMed⌕ Search

Biomedical subjects

K Obara

Publications and source records attributed to K Obara.

At least 19 recordsLinked to original sources
PubMed2006

Association between ADAM33 polymorphisms and adult asthma in the Japanese population.

BACKGROUND: ADAM33, a member of the ADAM (a disintegrin and metalloprotease) family, is a putative asthma susceptibility gene recently identified by positional cloning. It is important to know whether the association exists in ethnically diverse populations. OBJECTIVE: To assess whether genetic functional variants of ADAM33 relate to the susceptibility or some phenotypes in adult patients with bronchial asthma in a Japanese population. METHODS: We searched for single nucleotide polymorphisms (SNPs) in ADAM33 by PCR-directed sequencing and identified 48 SNPs. Fourteen SNPs were selected with regard to the LD pattern, and genotyped by Taq-Man and PCR-RFLP methods. We conducted an association study of ADAM33 with 504 adult asthmatic patients and 651 controls, and haplotype analyses of related variants were performed. RESULTS: Significant associations with asthma were found for the SNPs T1 (Met764Thr), T2 (Pro774Ser), S2 and V-3 (with the lowest P-value for T1, P = 0.0015; OR 0.63). We analysed the haplotype using these four polymorphisms, and found a positive association with haplotype CCTG (P = 0.0024). CONCLUSION: Our results replicate associations reported recently in other ethnic populations, and suggest that the ADAM33 gene is involved in the development of asthma through genetic polymorphisms.

ADAM Proteins↗
PubMed2006

Intraparotid pseudoglandular schwannoma.

A unique intraparotid location of a rare pseudoglandular schwannoma is described. Although the diagnosis of schwannoma could readily be substantiated, accurate subtyping was initially mislabeled. The pitfall was in failing to acknowledge the presence of multiple well-formed gland-like structures, which is instantly thought to be cystically dilated salivary ducts. Immunohistochemically, epithelial-appearing cells lining the duct-like spaces proved to be schwannian in nature. Interpretation of an immediately recognizable gland-like architecture is more problematic when a pseudoglandular variant originates from a nerve coursing through the gland, as here.

Adult↗
PubMed2005

Sclerosing mucoepidermoid carcinoma of the oral cavity.

Sclerosing mucoepidermoid carcinoma (SMEC) with eosinophilia is a rare but distinctive tumor usually affecting the thyroid. SMEC involvement of salivary gland is exceptional, with only six cases in the literature. We present here the first case of an intermediate-grade SMEC, arising from the intraoral minor salivary glands. A particularly interesting finding is the cytoplasmic accumulation of eosinophilic hyaline granules in carcinoma cells, similar to aberrant zymogen-like granules previously described in salivary sclerosing polycystic adenosis.

Adenoma↗
PubMed2005

Peripheral odontogenic tumor: a clinicopathologic study of 30 cases. General features and hamartomatous lesions.

BACKGROUND: Peripheral odontogenic tumors (POT), either neoplastic or hamartomatous, are rare. This study briefly summarizes the general features of POT and selectively reviews the histomorphologic spectrum of under-recognized hamartomatous lesions that we have designated peripheral odontogenic hamartomas (POH) in order to shed more light into the pathogenesis of POT. METHODS: Archival material accessioned at our institutions between 1970 and 2004 was systematically searched to identify examples of POT/POH. RESULTS: Among 39 660 biopsies, we retrieved 25 cases of 'classical' POT and five cases of 'unique' POH. Odontogenic fibroma and ameloblastoma were by far the most common. Of POH, two purely epithelial lesions showed multiple strands of basaloid rests [odontogenic gingival epithelial hamartoma (OGEH)] and a conglomerate of polyhedral epithelium, ghost cells and concentric calcifications (calcifying epithelial odontogenic tumor-like hamartoma), respectively. OGEH and peripheral squamous odontogenic tumor (PSOT) deserve to be a related entity. In two types of mixed POH, ectomesenchymal elements appeared juxtaposed to the squamous lining (gingival cyst-like organoid hamartoma) and ghost cells aggregated in the enamel organ of a microdont (peripheral odontoma). None of POH exhibited continuity with the surface epithelium. CONCLUSION: On the basis of this relatively limited series of cases, POH, to conceptualize a unified histogenetic source, are speculated to arise from the soft-tissue remnants of dental lamina. Gingival rests of Serres seem to retain the ability to pursue epithelial-ectomesenchymal interactions that are necessary leading to odontoma formation.

Ameloblastoma↗
PubMed2001

Anomalous magnetic-field dependence of positive ion mobility in normal liquid (3)He.

The positive ion mobility in normal liquid (3)He has been measured as a function of external magnetic field up to 15 T at temperatures down to 3 mK. At 3.2 mK, the field dependence is found to exhibit a pressure-dependent broad peak followed by a large decrease at pressures above 20 bars. On the other hand, at 20 mK, a monotonic decrease with increasing the magnetic field has been observed in the same pressure region. Possible origins for these anomalous behaviors are discussed.

Journal Article↗
PubMed2001

Sequential detection of alphafetoprotein-bearing cells in blood stem cell fraction of germ cell tumour patients.

High-dose chemotherapy with peripheral blood stem cell (PBSC) transplantation in advanced germ cell tumour (GCT) patients is widely applied. The aims of this study were: (1) To examine the presence of alphafetoprotein (AFP) bearing tumour cells in PBSC harvests from advanced GCT patients obtained after multiple cycles of induction chemotherapy. (2) To determine whether induction chemotherapy contributed to in vivo purging of the tumour. We evaluated cryopreserved PBSC samples from 5 patients with advanced stage II/III AFP producing GCT. PBSC were separated after the first, second and third cycles of induction chemotherapy. Those samples were analysed using the nested reverse transcription polymerase chain reaction (RT-PCR) method to detect AFP mRNA. Although, in all patients, AFP mRNA was detected in PBSC samples after the first or second cycle of induction chemotherapy, but was not detected in 3 of 4 samples after the third cycle of chemotherapy. Although it is not clear whether tumour cells contaminating PBSC fraction contribute to disease relapse, PBSC harvested after at least 3 cycles of induction chemotherapy might be recommended to avoid such a possibility.

Adult↗
PubMed2001

Frequency of PSA-mRNA-bearing cells in the peripheral blood of patients after prostate biopsy.

Transrectal ultrasound (TRUS) guided prostate biopsy is standard diagnostic procedure for prostate cancer (PCa). However, possibility of dissemination of cancer cells by biopsy is not negligible. To investigate this possibility, we examined prostate specific antigen (PSA)-bearing cells in peripheral blood of the 108 patients before and after prostate biopsy. Peripheral blood samples were obtained from 108 patients with elevated serum PSA (sPSA) levels, who had undergone sextant prostate biopsy using TRUS. The presence of PSA-mRNA bearing cells was examined using the nested RT-PCR method enabling detection of one LNCaP cell diluted in 1 ml of whole blood. Among 108 patients, 62 and 46 were diagnosed with benign prostatic hyperplasia (BPH) and PCa, respectively. PSA-mRNA was detected in 3 PCa cases but in no BPH patients before and after biopsy, and in 16 BPH (25.8%) and in 21 PCa (45.7%) patients only after biopsy (P< 0.01). The patients with positive mRNA before biopsy had higher sPSA (P< 0.001), and those after biopsy had higher sPSA and PSA density (PSAD) levels (P< 0.05). Positive PSA-mRNA cases had more cancer involved biopsy cores than the negative PSA-mRNA cases (P< 0.001). Although further investigations are needed, the present findings suggest that prostate biopsy might scatter prostate cells in the blood stream especially in cases with high sPSA and, thus, might contribute to tumour spreading in the cases of prostate cancer.

Adult↗
PubMed2001

Lipo prostaglandin E1 reduces the production of CXC chemokines in endotoxin-induced rat liver injury.

The present study attempted to assess the effect of prostaglandin E1 (PGE1) incorporated into lipid microspheres (Lipo PGE1) on chemokine production in endotoxin-induced rat liver injury. Male Wistar rats weighing 200-250 g were injected with 2 mg lipopolysaccharide (LPS) per kg intravenously. Lipo PGE1 was administered simultaneously at various concentrations (0.002, 0.02, 0.2, 2 µg/kg) in the tail vein. Blood samples and liver specimens were taken from the rats at 1, 3, 8, 12 and 24 h after injection with LPS alone or with LPS and Lipo PGE1. Serum macrophage inflammatory protein-2 (MIP-2) and cytokine-induced neutrophil chemoattractant (CINC) levels were measured by the enzyme-linked immunosorbant assay using the corresponding antibodies. Liver specimens were fixed, and the number of neutrophils that had infiltrated each liver section was determined under a microscope. Serum alanine aminotransferase (ALT) levels were significantly lower in the rats injected with LPS and Lipo PGE1 compared with those in the rats injected with LPS alone, and this difference was expressed in a PGE1 dose-dependent manner. Serum MIP-2 levels were significantly lower at 3 h (141.4+/-95.5 pg/ml) and 8 h (44.9+/-44.7 pg/ml) after injection with LPS and Lipo-PGE1 (2 µg/kg) than at the same times after injection with LPS alone (342.9+/-35.9 and 358.3+/-23.4 pg/ml, respectively). Similarly, serum CINC levels were significantly lower at 8 h (482.7+/-156.0 ng/ml) after injection with LPS and Lipo-PGE1 (2 µg/kg) than at the same time after injection LPS alone (723.3+/-29.0 ng/ml). No significant differences were observed at any time between serum tumor necrosis factor-alpha (TNF-alpha) levels in rats injected with LPS alone and in rats injected with LPS and Lipo-PGE1 (2 µg/kg). The number of neutrophils that had infiltrated the liver was significantly lower at 8 h after injection with LPS and Lipo PGE1 than at the same time after injection with LPS alone. This difference was expressed in a Lipo PGE1 dose-dependent manner. In conclusion, Lipo PGE1 reduces liver injury and serum levels of MIP-2 and CINC, but not TNF-alpha, in rats injected with LPS and also reduces the number of neutrophils that infiltrate in the liver.

Journal Article↗
PubMed2001

G-protein coupled receptor kinase 2 and 3 expression in human detrusor cultured smooth muscle cells.

The aim of this study was to investigate the expression of G-protein coupled receptor kinases (GRKs) mRNA by RT-PCR and GRKs protein by immunohistochemistry in human detrusor cultured smooth muscle. Primary cultures of human detrusor smooth muscle cells were established using the explant method from three normal bladders. The expression of each GRK, beta-adrenergic receptor and muscarinic acethylcholine receptor (mAchR) mRNA was examined by reverse transcription polymerase chain reaction (RT-PCR). Immunohistochemical staining was also performed using primary antibodies for GRKs. The GRK2 and GRK3 transcripts were detected by RT-PCR. The m2, m3 and m5 mAchR and beta1, beta2 and beta3 adrenergic receptor subtypes mRNA were also detected. Using immunohistochemistry, both GRK2 and GRK3 were found to be expressed in detrusor smooth muscle cells. These results demonstrated the existence of GRK2 and GRK3 and the co-expression of m2, m3 and m5 mAchR and beta1, beta2 and beta3 adrenergic receptor subtypes in detrusor smooth muscle cells. The possibility exists that these kinases play a role in the desensitization mechanism of mAchR and beta adrenergic receptors.

Cell Size↗
PubMed2001

Parathyroid hormone increases the expression level of matrix metalloproteinase-13 in vivo.

Parathyroid hormone (PTH) increases serum calcium (Ca) by enhancing bone resorption and renal Ca reabsorption. However, detailed mechanisms of enhanced bone resorption by PTH remain to be elucidated. Although PTH has been shown to increase the expression level of osteoblastic matrix metalloproteinase (MMP)-13 in vitro, only limited results are available regarding the in vivo regulation of MMP expression. In the present study, we have examined expression levels of MMPs in PTH-infused rats. Infusion of 1.5 or 2.0 nmol/kg/day rat PTH(1-34) for 3 days resulted in a dose-dependent increase in serum Ca. PTH infusion also decreased serum phosphate levels and increased urinary excretion of Ca and phosphate. Infusion of PTH for 7 days resulted in less severe hypercalcemia and hypophosphatemia. Urinary Ca and phosphate excretion in rats infused for 7 days was less than that in rats infused for 3 days. Northern blot analysis showed that PTH infusion increased the expression level of MMP-13 in calvaria, although it did not affect MMP-2 expression. Furthermore, the time-course and severity of hypercalcemia and hypercalciuria correlated with the expression level of MMP-13. In situ hybridization also showed that PTH infusion increased the expression level of MMP-13 in femora. These results indicate that PTH enhances MMP-13 expression in vivo and suggest that PTH stimulates bone resorption at least partly by enhancing MMP-13 expression.

Animals↗
PubMed2001

Molecular characterization of weak D phenotypes by site-directed mutagenesis and expression of mutant Rh-green fluorescence protein fusions in K562 cells.

BACKGROUND AND OBJECTIVES: Mutations detected in 161 weak D samples from Caucasians have been classified into 16 types. Because flow cytometry using monoclonal anti-D antibodies (mAbs) has shown that weak D red cells display type-specific antigen density, these mutations in transmembranous regions have been assigned weak D phenotypes. The present study attempts to confirm or refute this assignment. MATERIALS AND METHODS: We amplified DNA from four Japanese weak D samples using the polymerase chain reaction (PCR), and directly sequenced the amplified DNA. Using site-directed mutagenesis, we constructed three vectors expressing mutant RHDs-- G212C, V270G (weak D type 1) and G358A (type 2)--in K562 cells. The expression of RhD antigens was examined by flow cytometry using mAbs. RESULTS: A new mutation resulting in a conversion at amino acid residue 212 (Gly to Cys) was detected in a Japanese weak D sample. K562 cells transduced with mutant RhD cDNA reacted weakly in a type-specific manner with mAbs. CONCLUSIONS: The mutations--G212C (new weak D type), V270G (weak D type 1) and G358A (type 2)-- in transmembranous regions had obvious effects on the D epitopes recognized by mAbs. The results of this study provide direct evidence that these mutations can account for weak D phenotypes.

Antibodies, Monoclonal↗
PubMed2001

Endoscopic recurrence of esophageal varices is associated with the specific EUS abnormalities: severe periesophageal collateral veins and large perforating veins.

BACKGROUND: Endoscopic ultrasonography (EUS) with a 20 MHz ultrasound (US) catheter probe can clearly demonstrate esophageal collateral veins. The presence of large periesophageal collateral veins has been correlated with large esophageal varices in patients with portal hypertension. The correlation between the size of esophageal collateral veins and endoscopic recurrence of esophageal varices in patients with portal hypertension who had undergone endoscopic injection sclerotherapy was investigated. Furthermore, whether EUS findings could predict the variceal recurrence was retrospectively studied. METHODS: Thirty-eight patients who had undergone endoscopic injection sclerotherapy were examined every 3 to 4 months with endoscopy and US catheter probe for a period of 2 years. Recurrence of esophageal varices was determined by endoscopic findings of either new varix formation or appearance of red color sign. Esophageal collateral veins were identified by US catheter probe as peri-esophageal collateral veins (adjacent to the esophageal wall) and para-esophageal collateral veins (separated from the esophageal wall) along with perforating veins; and they were graded as severe and mild type by US catheter probe. RESULT: Ten of the 38 patients (26.3%) had endoscopic recurrence at a mean of 10.9 months after endoscopic injection sclerotherapy. In patients with endoscopic recurrences, EUS findings included a significantly (p < 0.001) higher incidence of severe type peri-esophageal collateral veins, a significantly larger number of perforating veins (p < 0.001) and a significantly larger diameter of perforating veins (p < 0.001) compared with patients without recurrence (8 of 10, 80% vs. 2 of 28, 7.1%; 1.30 vs. 0.21; 2.00 vs. 0.32 mm, respectively). The presence of veins at the esophagogastric junction did not correlate with recurrence. CONCLUSION: Severe type peri-esophageal collateral veins and large perforating veins of the esophagus detected by EUS in patients treated by endoscopic injection sclerotherapy signify recurrence of esophageal varices and predict endoscopic recurrence of varices in subsequent months.

Collateral Circulation↗
PubMed2001

Protein/oligonucleotide conjugates as a cell specific PNA carrier.

We have focused on proteineus ligand conjugate with oligonucleotides (ODNs) as a cell-specific delivery vector for peptide nucleic acids (PNAs). Asialofetuin (AF), a hepatocyte-specific proteineus ligand, was conjugated with ODNs that served as binding sites for PNAs. Succinimidyl-transe-4(N-maleimidylmethyl)-cyclohexane-1-carboxylate (SMCC) modified AF was coupled with 5'-thiolated oligodeoxynucleotide (HS-ODN). The resulting conjugate held PNAs with sequence-specific manner. The PNA/DNA conjugate complex has resistance against nucleases in serum. The efficient release of PNA from the complex was observed when the complex was made in contact with a target nucleotide. PNA uptake to hepatocytes was greatly enhanced when hepatocytes was incubated with PNA/conjugate complex. Free AF thoroughly inhibited PNA uptake with the conjugate, evidencing asialoglycoprotein receptor (ASGP-R) mediated endocytosis to be a major-route for the cellular uptake.

Animals↗