Small intestinal volvulus in a captive Steller sea lion (Eumetopias jubatus).
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to Y Shimoyama.
Explore the source record for details and available documents.
Pleomorphic adenomas of the salivary gland were diagnosed in two dogs. The tumours were single, firm and well circumscribed, with a smooth cut surface. Metastatic tumours were not detected. Histopathological examination revealed that the tumours contained multiple cysts lined with luminal epithelial cells and myoepithelial cells, and mucinous, myxochondroid and cartilaginous tissues. Immunohistochemical examination demonstrated labelling of luminal epithelial cells and myoepithelial cells, and mucinous, myxochondroid and cartilaginous tissues with antibodies to cytokeratin LU-5, AE1/AE3, CK-14, CALP, a-SMA, vimentin, GFAP, and S-100. Labelling for GFAP indicated stromal transformation into myxoid and chondroid tissues.
BACKGROUND AND STUDY AIMS: Advances in endoscopy have led to imaging of the details of the gastric mucosa, but the histological diagnosis usually has to be confirmed by endoscopic biopsy. A method of confocal endomicroscopy that has recently been developed allows the observation of living cells in vivo. Several investigators have reported that the technique is of value, but there have as yet been no studies describing its application in gastric cancer. PATIENTS AND METHODS: Twenty-seven patients with early gastric cancer underwent confocal endomicroscopy (Pentax EG-3870CIK; Pentax, Tokyo, Japan). After intravenous administration of fluorescein sodium, confocal images obtained from the normal mucosa and from cancerous lesions were interpreted by two pathologists independently and compared with the histological findings, including CD34 immunostaining of biopsy specimens or resected specimens from the same sites. RESULTS: Fluorescein yielded high-quality confocal images of the gastric mucosa; if cancer could be targeted (59%) images were mostly graded good. The images corresponded to the hematoxylin-eosin staining of transverse sections of specimens from the same sites. In the results for the interpretation by the two pathologists, the accuracy for the diagnosis of gastric cancer was 94.2% (pathologist A), and 96.2% (pathologist B), respectively. The accuracy decreased substantially when poor images and inaccessible lesions were included. CONCLUSIONS: Confocal endomicroscopy is useful in the diagnosis of gastric cancer but good quality images cannot always be obtained. In the future, it may allow virtual biopsy and help reduce unnecessary biopsies.
Medullary sponge kidney was diagnosed in a 10-year-old male Shih Tzu dog with a long history of hyposthenuria, but with no other findings indicating renal failure or hormonal aberration. At the dog's death from heart failure, an autopsy was performed. On gross morphology, bilateral kidneys were normal size and had many cysts ranging from the corticomedullary junction to renal papillae. Histopathologic findings showed that almost all of the cysts were lined by monolayered or multilayered and columnar or cuboidal epithelium with chilium similar to epididymis. Immunohistochemically, all of these cells were strongly positive for AE1/AE3 and negative for vimentin. Many of these cells were positive for cytokeratin 7 (CK7), and only a few cells were positive for desmin. The results of staining are the same as those for epithelium of the collecting duct of normal canine kidney. This is the first report of this pathologic entity in the canine kidney.
Explore the source record for details and available documents.
Glial cell line-derived neurotrophic factor (GDNF) signals through multisubunit receptor complex consisting of RET tyrosine kinase and a glycosylphosphatidylinositol-anchored coreceptor called GDNF family receptor alpha1 (GFRalpha1). In the current study, we cloned a human SEP1 gene as a GDNF-inducible gene using human neuroblastoma cells that express RET and GFRalpha1. The induction of the SEP1 gene showed two peaks at 0.5-2 h and 24-48 h after GDNF stimulation by Northern blotting and quantitative real-time reverse transcriptase polymerase chain reaction. The late induction was also confirmed at protein levels by Western blotting with anti-SEP1 antibody. Immunostaining revealed that the expression of the SEP1 protein was detected in cell body, elongated neurites and growth cone-like structure of neuroblastoma cells treated with GDNF. In addition, we found a high level of SEP1 expression in neurons of the dorsal root and superior cervical ganglia and motor neurons of the spinal cord of mice in which RET is also expressed. SEP1 was co-immunoprecipitated with alpha- and beta-tubulins from the lysate of mouse brain. These results thus suggested that SEP1 is a GDNF-inducible and microtubule-associated protein that may play a role in the nervous system.
We examined the production of substance P (SP) in synovial fibroblasts derived from patients with rheumatoid arthritis (RA) and osteoarthritis (OA). Immunoreactive SP was observed in non-stimulated RA fibroblasts. The expression of beta-preprotachykinin-A (beta-PPT-A) mRNA was confirmed by reverse transcription-polymerase chain reaction analysis. SP contents in culture medium were increased by treatment of RA fibroblasts with transforming growth factor-beta (TGFbeta) (10 ng/ml). Levels of SP release were elevated at 12 h after TGFbeta stimulation whereas the expression of beta-PPT-A mRNA was enhanced at 3 h. Furthermore, SP production in response to TGFbeta was dose-dependently enhanced by basic fibroblast growth factor (bFGF). OA fibroblasts also significantly released SP in the presence of TGFbeta (10 ng/ml) plus bFGF (50 ng/ml). These results suggest that SP produced by synovial fibroblasts may participate in joint diseases.
Although N-cadherin is necessary for organ formation originating in the endoderm, the expression of N-cadherin in gastric carcinoma and its role has not yet been reported. The present study was conducted to determine the pattern of immunohistochemical expression of E-cadherin and N-cadherin, using formalin-fixed, paraffin-embedded tissues from 97 primary gastric carcinomas, including 17 which were producing alpha-fetoprotein (AFP). Samples were subdivided into 50 tubular adenocarcinomas and 47 poorly differentiated adenocarcinomas. Results showed that E-cadherin was expressed in varying degrees in areas of cell adhesion between tumor cells, in 94 out of 97 cases studied. Three cases which showed no expression of E-cadherin were diagnosed as AFP-producing tumors by immunohistochemistry. Expression of N-cadherin was observed in varying degrees in the intercellular spaces between tumor cells in 11 tubular adenocarcinomas and in six poorly differentiated adenocarcinomas, including E-cadherin-negative cases, all of which were AFP positive. The present findings suggest a possible role for N-cadherin in gastric carcinoma.
Explore the source record for details and available documents.
By means of heparin-affinity and glycyrrhizin (GL)-affinity column chromatographies (HPLC), a GL-binding phospholipase A2 (gbPLA2) was selectively purified from the synovial fluids of patients with rheumatoid arthritis. This purified gbPLA2 was identified as a secretory type IIA PLA2 (sPLA2-IIA) since it was crossreacted with anti-sPLA2-IIA serum. The activity of purified sPLA2-IIA was inhibited by glycyrrhetinic acid (GA) and a GA derivative (oGA) in a dose-dependent manner, but it was more sensitive to GA than GL. Furthermore, it was found that (i) purified sPLA2-IIA is phosphorylated by casein kinase II (CK-II) in vitro; (ii) this phosphorylation induces in a significant stimulation of PLA2 activity; and (iii) oGA at one-tenth the concentration of GL inhibits the CK-II-mediated stimulation of sPLA2-IIA activity. These results show that (i) sPLA2-IIA is a GL-binding protein; and (ii) CK-II mediates stimulation of its PLA2 activity in vitro.
We identified three novel human type-II classic cadherins, cadherin-7, -9 and -10, by cDNA cloning and sequencing, and confirmed that they interact with catenins and function in cell-cell adhesion as do other classic cadherins. Cell-cell binding activities of the eight human type-II classic cadherins, including the three new molecules, were evaluated by long-term cell-aggregation experiments using mouse L fibroblast clones transfected with the individual cadherins. The experiments indicated that all the type-II cadherins appeared to possess similar binding strength, which was virtually equivalent to that of E-cadherin. We next examined the binding specificities of the type-II cadherins using the mixed cell-aggregation assay. Although all of the type-II cadherins exhibited binding specificities distinct from that of E-cadherin, heterophilic interactions ranging from incomplete to complete were frequently observed among them. The combinations of cadherin-6 and -9, cadherin-7 and -14, cadherin-8 and -11, and cadherin-9 and -10 interacted in a complete manner, and in particular cadherin-7 and -14, and cadherin-8 and -11 showed an indistinguishable binding specificity against other cadherin subclasses, at least in this assay system. Although these data were obtained from an in vitro study, they should be useful for understanding cadherin-mediated mechanisms of development, morphogenesis and cell-cell interactions in vivo.
Lactoferrin (LF) from bovine colostrum was biochemically characterized as a glycyrrhizin (GL)-binding protein (gbP) in vitro. It was found that (i) bovine LF (bLF) and a synthetic bovine lactoferricin (bLFcin, the N'-terminal region of bLF at the positions 17--41) had a high affinity to a GL-affinity column; (ii) approximately 1.8 moles of GL were bound to a molecule of bLF with a binding constant of approx. 1.20x10(4) M(-1) at pH 6.8; and (iii) GL, but not glycyrrhetinic acid (GA), induced a conformational change of bLF. In addition, the glucuronic acid moiety of the GL molecule was found to be responsible for binding to bLF, because (i) no binding of GA and two glucoses-GA (Glc-Glc-GA) to bLF was detected; and (ii) a synthetic fluorinated GL (GlcA-GlcF-GA) and mono-glucuronyl-GA (mono-GlcA-GA) were bound significantly to bLF. A similar binding of GL to human LF (hLF) was also observed under the same experimental conditions. Data provided here suggest that (i) bLF contains plural GL-binding sites; and (ii) the specific binding of GL to bLF may modulate the physiological activity of bLF in vivo.
Differentiation of human T cells into T helper (Th)1 and Th2 cells is vital for the development of cell-mediated and humoral immunity, respectively. However, the precise mechanism responsible for the Th1 cell differentiation is not fully clarified. We have studied the expression and function of Txk, a member of the Tec family of nonreceptor tyrosine kinases. We found that Txk expression is restricted to Th1/Th0 cells with IFN-gamma producing potential. Txk transfection of Jurkat T cells resulted in a several-fold increase of IFN-gamma mRNA expression and protein production; interleukin (IL)-2 and IL-4 production were unaffected. Antisense oligodeoxynucleotide of Txk specifically inhibited IFN-gamma production of normal peripheral blood lymphocytes, antigen-specific Th1 clones, and Th0 clones; IL-2 and IL-4 production by the T cells was unaffected. Txk cotransfection led to the enhanced luciferase activity of plasmid (p)IFN-gamma promoter/enhancer (pIFN-gamma[-538])-luciferase-transfected Jurkat cells upon mitogen activation. Txk transfection did not affect IL-2 and IL-4 promoter activities. Thus, Txk specifically upregulates IFN-gamma gene transcription. In fact, Txk translocated from cytoplasm into nuclei upon activation and transfection with a mutant Txk expression plasmid that lacked a nuclear localization signal sequence did not enhance IFN-gamma production by the cells, indicating that nuclear localization of Txk is obligatory for the enhanced IFN-gamma production. In addition, IL-12 treatment of peripheral blood CD4(+) T cells enhanced the Txk expression, whereas IL-4 treatment completely inhibited it. These results indicate that Txk expression is intimately associated with development of Th1/Th0 cells and is significantly involved in the IFN-gamma production by the cells through Th1 cell-specific positive transcriptional regulation of the IFN-gamma gene.
Classic cadherins can be grouped based on their deduced primary structures. Among them the type I cadherins have been well characterized; however, little is known about non-type I cadherins. In this study we characterized two human type II cadherins, cadherin-6 and cadherin-14, using a cDNA transfection system. They were each detected as two bands electrophoretically, were expressed on the external cell surface at cell-cell contact sites, and were associated with caten- ins. Direct sequencing of the N-terminal amino acids showed that the two bands of cadherin-14 corresponded to precursor and mature forms, whereas the two bands of cadherin-6 both had the N-terminal sequence of the mature form. Unlike type I cadherins, both cadherin-6 and -14 were not protected from trypsin degradation by Ca2+. We evaluated their adhesive functions by a long term cell aggregation method. The results suggest that both cadherin-6 and -14 have cell-cell binding strengths virtually equivalent to that of E-cadherin and that their binding specificities are distinct from that of E-cadherin. Cadherin-6 and -14 interacted with each other in an incomplete manner. They have a QAI tripeptide in the first extracellular subdomain instead of the HAV motif that is characteristic of type I cadherins and is intimately involved in the adhesive function. The QAI tripeptide, however, appeared not to be involved in the adhesive functions of cadherin-6 and -14.
Explore the source record for details and available documents.
OBJECTIVE: To clarify the mechanism(s) for the interaction between warfarin and benzbromarone, a uricosuric agent, and to predict changes in the in vivo pharmacokinetics of (S)-warfarin from in vitro data. METHODS: Warfarin enantiomers and benzbromarone in serum, 7-hydroxywarfarin in urine, and serum unbound fractions of warfarin enantiomers were measured in patients with heart disease given warfarin with (n = 13) or without (n = 18) oral benzbromarone (50 mg/d). In vitro inhibition constants (K(i)) of benzbromarone for (S)-warfarin 7-hydroxylation were determined with use of human CYP2C9 and liver microsomes. The magnitude of changes in the formation clearance for 7-hydroxylation (CLf), the unbound oral clearance (CL(oral,u)), and the oral clearance (CL(oral)) for (S)-warfarin were predicted by equations incorporating the in vitro Ki, the theoretical maximum unbound hepatic benzbromarone concentration, and the fractions of warfarin eliminated through metabolism and of CYP2C9-mediated metabolic reaction susceptible to inhibition by benzbromarone. RESULTS: The patients given warfarin with benzbromarone required a 36% less (P < .01) warfarin dose than those given warfarin alone (2.5 versus 3.9 mg/d) to attain similar international normalized ratios (2.1 and 2.2, respectively), and the former had 65%, 53%, and 54% lower (P < .05 or P < .01) CLf, CL(oral),u, and CL(oral) for (S)-warfarin than the latter, respectively. In contrast, no significant differences were observed for (R)-warfarin kinetics between the groups. Benzbromarone was found to be a potent competitive inhibitor (Ki < 0.01 micromol/L) for (S)-warfarin 7-hydroxylation mediated by CYP2C9. The average changes in the in vivo CLf, CL(oral),u, and CL(oral)values for (S)-warfarin induced by benzbromarone were largely predictable by the proposed equations. CONCLUSION: Benzbromarone would intensify anticoagulant response of warfarin through an enantioselective inhibition of CYP2C9-mediated metabolism of pharmacologically more potent (S)-warfarin. The magnitude of changes in the in vivo warfarin kinetics may be predicted by in vitro data.
Serum albumin has one reactive sulfhydryl (Cys-34) that is one of the important binding sites. Cys-34 is located in the crevice on the surface of the albumin molecule and is therefore restricted in its motion. Bovine serum albumin (BSA) Fraction V forms a transparent gel at pD 4.0 (F-form) in D2O at protein concentrations above 7% (BSA*-gel). We studied the molecular motion of Cys-34 on BSA in the solution and gel states by the vector electron paramagnetic resonance (EPR) method using a maleimide spin label. The rotational correlation times of the spin label bound to Cys-34 in the BSA solution and BSA*-gel were in the order of 10(-6) and 10(-5) s, respectively. A longer rotational correlation time of the Cys-34 spin label in the BSA*-gel suggested that the gel network formed in BSA may drastically slow the motion of Cys-34. The integrated value obtained from the vector EPR spectra also showed an extremely dramatic slowing of the Cys-34 spin label during the gel formation. On the other hand, the values for order parameter and the inclination of the principal axis (z) of the Cys-34 spin label to the rotational axis (mu) were the same in the BSA solution and BSA*-gel.
Recent developments of a Ki67 antibody to recombinant parts of the Ki67 nuclear antigen have provided a marker for tumor proliferation. In the present study, biopsy specimens were obtained from 20 patents with squamous cell carcinoma of the oral cavity at various sites, who also received a regional neck dissection. The patients' mean age was 61 years. Normal mucosa obtained from the surgical materials of 10 patients with a non-tumor condition was also examined as a control. The expression of Ki67 was examined immunohistochemically and the labeling index (LI) assessed in the biopsy specimens. The patients were divided into two groups; patient who already had a regional lymph node metastasis at the time of tumor resection and patient without any metastasis. All of the oral carcinoma and normal mucosa specimens were positive for Ki67, while the magnitude of staining showed a wide variation. The median LI of the patients with metastasis and without metastasis was 37.63 +/- 8.30 and 20.40 +/- 4.22 respectively, while the normal mucosa control was 7.62 +/- 1.70. The results of this study suggest that an immunohistochemical examination of the biopsy materials for the Ki67 antigen and assessed LI index should prove useful for the prediction of lymph node metastasis.