Medullary sponge kidney in a 10-year-old Shih Tzu dog

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.

Confocal endomicroscopy for the diagnosis of gastric cancer in vivo

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.

Pleomorphic adenoma of the salivary gland in two dogs

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.

Neuroendocrine carcinoma in the nasal cavity of ten dogs

Neuroendocrine (NE) carcinoma was diagnosed in 10 dogs. In six cases examined by cephalometric radiography and computerized tomography, a large mass was seen to fill the nasal cavity. Histopathologically, sheets, nests or ribbons of neoplastic cells were separated by delicate or thick fibrovascular stroma. The neoplastic cells were round, oval, or spindle-shaped; cytoplasmic granules and hyperchromatic nuclei with prominent nucleoli were present. Neoplastic cells were invariably immunohistochemically positive for cytokeratin (CK) AE1/AE3, neuron-specific enolase, chromogranin A and vasoactive intestinal polypeptide. Eight dogs were positive for S100 protein, seven for synaptophysin, five for protein gene product 9.5, two for somatostatin, and one for Leu-7. Immunolabelling gave negative results for CK 8, CK 19, calcitonin, calcitonin gene-related polypeptide, neurofilaments, serotonin, gastrin and glial fibrillary acidic protein. Ultrastructurally, the neoplastic cells contained a large number of round, membrane-bounded, densely-cored granules corresponding to neurosecretory granules. These observations were consistent with the neuroendocrine nature of the carcinomas.

Identification of human SEP1 as a glial cell line-derived neurotrophic factor-inducible protein and its expression in the nervous system

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.

Preferential expression of B7.2 (CD86), but not B7.1 (CD80), on B cells induced by CD40/CD40L interaction is essential for anti-DNA autoantibody production in patients with systemic lupus erythematosus

OBJECTIVE

B7 (CD80/CD86) molecules are over-expressed in patients with SLE. However, it is not clear whether CD80/CD86 molecules are involved in the pathogenic autoantibody production specifically or in the polyclonal antibody production in human SLE. The present study was carried out to characterize B7 molecules on B cells in autoantibody production.

METHODS

Expression of costimulatory molecules was analyzed by RT-PCR and two-color immunofluorescence staining. Purified B cells were co-cultured with T cells in the presence of anti-costimulatory molecule antibody.

RESULTS

Excessive expression of CD86 and CD80 molecules was evident on freshly isolated B cells in patients with SLE. Normal B cells did not express CD86 molecules spontaneously and expressed it after co-culture with activated T cells. CD86 expression on normal and SLE B cells induced by the activated T cells was inhibited by the addition of anti-CD40L into the cell culture. Furthermore, CD40L expression on T cells upon activation was enhanced in SLE patients. Anti-DNA antibody production by SLE B cells in the presence of activated T cells was markedly inhibited by anti-CD86, but not anti-CD80. Anti-CD86 treatment inhibited polyclonal Ig and anti-SS-A antibody production of SLE B cells, suggesting the preferential involvement of CD86 in polyclonal antibody production.

CONCLUSION

SLET T cells express CD40L excessively, and the CD40/CD40L pathway is involved in the CD86 over-expression of SLE B cells; thus T cell abnormality is at least partially involved in B cell hyperactivity. Enhanced CD86 expression of B cells by CD40L is essential for polyclonal antibody production.

Characterization of secretory type IIA phospholipase A2 (sPLA2-IIA) as a glycyrrhizin (GL)-binding protein and the GL-induced inhibition of the CK-II-mediated stimulation of sPLA2-IIA activity in vitro

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.

Co-expression of N-cadherin and alpha-fetoprotein in stomach cancer

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.

Production of neuropeptide substance P by synovial fibroblasts from patients with rheumatoid arthritis and osteoarthritis

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.

Identification of three human type-II classic cadherins and frequent heterophilic interactions between different subclasses of type-II classic cadherins

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.

Biochemical characterization of bovine lactoferrin as a glycyrrhizin-binding protein in vitro

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.

Potentiation of anticoagulant effect of warfarin caused by enantioselective metabolic inhibition by the uricosuric agent benzbromarone

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.

Synovium infiltrating T cells induce excessive synovial cell function through CD28/B7 pathway in patients with rheumatoid arthritis

OBJECTIVE

To clarify involvement of synovial T cells in the development of synovial inflammation in patients with rheumatoid arthritis (RA), we analyzed cellular interactions between synovial cells and infiltrating T cells via CD28/B7-1 and B7-2.

METHODS

Synovial cells and infiltrating T cells were recovered separately from RA synovial tissues. Expression of CD28, B7-1, and B7-2 of synovial cells was analyzed by immunohistochemical staining and immunofluorescence analysis. Interleukin 1beta (IL-1beta), IL-6, and matrix metalloprotease 3 (MMP-3) secreted by synovial cells in the presence of infiltrating T cells were measured by ELISA. Nuclear transcription factor CD28 responsive complex was detected by a gel shift assay.

RESULTS

Both CD28+ T cells and B7-1/B7-2+ cells were found accumulating in the mononuclear cell infiltrate of RA synovial tissues and B7-1/B7-2+ cells were mainly LeuM3+ synovial cells. CD28 responsive complex was detected in nuclear extracts of freshly isolated lymphocytes from RA synovial tissues, but not those from osteoarthritis synovial tissues or normal peripheral blood, suggesting in vivo activation of T cells by the CD28/B7-1/B7-2 interactions. The irradiated autologous synovium infiltrating T cells notably enhanced IL-1beta, IL-6, and MMP-3 production by the synovial cells. The enhancement of proinflammatory cytokine and MMP-3 production by the synovial cells co-cultured with the T cells was abolished by the addition of CTLA4-Ig, anti-B7-1, and anti-B7-2 monoclonal antibodies.

CONCLUSION

These results suggest that cellular interactions between synovium infiltrating T lymphocytes and synovial cells via B7/CD28 pathways are intimately associated with development and exacerbation of inflammation in RA synovial cells.

Predicting tumor metastasis in patients with oral cancer by means of the proliferation marker Ki67

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.

Biochemical characterization and functional analysis of two type II classic cadherins, cadherin-6 and -14, and comparison with E-cadherin

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.

Investigation of slow dynamics of the sulfhydryl in the solution and gel states of bovine serum albumin: A vector electron paramagnetic resonance study

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.

Modulation by proinflammatory cytokines of Fas/Fas ligand-mediated apoptotic cell death of synovial cells in patients with rheumatoid arthritis (RA)

Synovial cell hyperplasia is a characteristic of patients with RA. Excessive proliferation of RA synovial cells is, in part, responsible for the synovial cell hyperplasia. In addition, synovial cell death that would reduce synovial cell number may be defective, leading to the hyperplasia. Thus, the defective control of cell death as well as cell proliferation may be of central importance in the pathogenesis of RA. In this study we analysed effects of proinflammatory cytokines on Fas/Fas ligand (FasL)-induced synovial cell apoptosis, and evaluated apoptosis-associated protein expression in the synovial cells in patients with RA. RA synovial cells expressed Fas antigen and lymphocytes infiltrating into RA synovium expressed FasL. Apoptotic synovial cells were detected within the sublining layer of RA synovium. Anti-Fas MoAb induced apoptosis of RA synovial cells in vitro, and proinflammatory cytokines tumour necrosis factor-alpha (TNF-alpha) and IL-1beta, but not IL-6 or IL-8, inhibited the anti-Fas-induced apoptosis accompanying up-regulation of Bcl-2 protein expression and reduced expression of CPP32 and ICH-1L. Immunohistochemical study revealed that CPP32 and ICH-1L were expressed weakly in the RA synovial lining cells compared with osteoarthritis (OA) synovial lining cells. Thus, we found that although RA synovial cells could die via apoptosis through Fas/FasL pathway, apoptosis of synovial cells was inhibited by proinflammatory cytokines present within the synovium. Inhibition of apoptosis by the proinflammatory cytokines may contribute outgrowth of synovial cells that leads to pannus formation and the destruction of joints in patients with RA.

Characterization of an apoptosis-inducing factor in Habu snake venom as a glycyrrhizin (GL)-binding protein potently inhibited by GL in vitro

By means of successive heparin-affinity and glycyrrhizin (GL)-affinity column chromatographies (HPLC), a 55 kDa GL-binding protein (gp55) was purified to apparent homogeneity from the Superdex P-I fraction of Habu snake venom. This gp55 was identified as an apoxin I-like protein, because (i) its 20 N-terminal amino acid residues (AHDRNPLEEYFRETDYEEFL) are 95% identical with the corresponding sequence of apoxin I (apoptosis-inducing factor, approx. 55 kDa) in the venom of the western diamondback rattlesnake; and (ii) L-amino acid oxidase (LAO) activity of gp55 is detected when incubated with L-leucine, but not with D-leucine. GL inhibited the LAO activity of gp55 in a dose-dependent manner, but had no effect on the activity of a 65 kDa LAO also purified from Habu snake venom. In addition, GL reduced the ability of gp55 to induce the hemolysis of sheep red blood cells. These results suggest that GL is a potent inhibitor of apoxin I-like proteins in harmful snake venoms.

Separation of phospholipase A2 in Habu snake venom by glycyrrhizin (GL)-affinity column chromatography and identification of a GL-sensitive enzyme

By means of glycyrrhizin (GL)-affinity and Mono S column chromatographies (HPLC), at least four GL-binding proteins (p25, p17, p15-1 and p15-2) in the two Superdex fractions (P-II and P-III fractions) from Habu snake venom were selectively purified. By determination of their N-terminal partial amino acid sequences, a metalloprotease (p25) and three GL-binding phospholipases A2 (gbPLA2s) [PA2Y (p17), PA21 (p15-1) and PA2B (p15-2)] were identified. PA2B (lysine-49 PLA2) was found to be the most sensitive to GL because (i) it strongly bound to a GL-affinity column; and (ii) its enzyme activity was selectively inhibited by low dose (ID50 = approx. 1.5 microM) of GL, but not by GA. Furthermore, these three gbPLA2s were phosphorylated by casein kinase II (CK-II) in vitro and GL inhibited the CK-II-mediated stimulation of their enzyme activities in vitro.

Molecular cloning and characterization of a novel human classic cadherin homologous with mouse muscle cadherin

We used a novel cDNA cloning method based on the cadherin-beta-catenin protein interaction and identified a new human classic-type cadherin, which we named cadherin-15, from adult brain and skeletal muscle cDNA libraries. Sequence analysis revealed that this cadherin was closely related to mouse muscle cadherin and seemed to be its human counterpart. However, its deduced amino acid sequence differed from that of mouse muscle cadherin in that it had an extra 31-amino acid sequence at its C terminus that has been found neither in mouse muscle cadherin nor in any other known classic cadherin. Analysis of cadherin-15 protein expressed in L fibroblasts showed that it was cleaved proteolytically, expressed on the cell surfaces as a mature form of about 124-kDa, and functioned as a cell-cell adhesion molecule in a homophilic and specific manner, but Ca2+ did not protect it against degradation by trypsin. Our findings also suggest that cadherin-15 mediates cell-cell adhesion with a binding strength comparable to that of E-cadherin.

Determination of unbound warfarin enantiomers in human plasma and 7-hydroxywarfarin in human urine by chiral stationary-phase liquid chromatography with ultraviolet or fluorescence and on-line circular dichroism detection

Enantiomers of warfarin and 7-hydroxywarfarin in human plasma and urine, respectively, were determined by high-performance liquid chromatography using a cellulose-derivative column with UV or fluorescent detection, and their absolute configuration was determined simultaneously by a circular dichroism spectropolarimeter connected in series. Enantiomers of warfarin and its major metabolites [i.e., (R)-6-hydroxywarfarin, (S)-7-hydroxywarfarin and (RS)-warfarin alcohol] were well resolved. The method was precise and sensitive: within- and between-day coefficients of variation were <9.6% for warfarin enantiomers in plasma and <7.1% for 7-hydroxywarfarin enantiomers in urine, respectively, and the lower detection limits were 20 ng/ml for (R)-warfarin, 40 ng/ml for (S)-warfarin, 2.5 ng/ml for (R)-7-hydroxywarfarin and 4.5 ng/ml for (S)-7-hydroxywarfarin in 0.5 ml of both plasma and urine. The ultrafiltration technique was used for determining unbound concentrations of warfarin enantiomers in plasma using [14C]warfarin enantiomers resolved by the present HPLC system. Clinical applicability of the method was evaluated by determining unbound concentrations of warfarin enantiomers in five consecutive plasma samples obtained from a patient exhibiting an unstable anticoagulant response to warfarin (4 mg/day, p.o.). Results indicated that the present method would be useful in clarifying factors responsible for a large intra- and inter-patient variability in warfarin effects with regard to unbound plasma enantiomer pharmacokinetics.

Biochemical characterization of glycyrrhizin as an effective inhibitor for hyaluronidases from bovine testis

The inhibitory effects of several anti-inflammatory agents, including glycyrrhizin (GL), on the activities of hyaluronidases (HAses) purified from bovine testes and Streptomyces were investigated in vitro. It was found that (i) GL inhibits the activity of HAse (p55) from bovine testes in a dose-dependent manner, but does not affect HAse from Streptomyces; (ii) GL was the most effective of the compounds tested on bovine testis HAse activity (50% inhibition with approx. 3 microM GL); and (iii) glycyrrhetinic acid (GA), a derivative (oGA) of GA and diglucuronic acid had no detectable effects on HAse activity at 9.0 microM. The GL-induced inhibition of HAse activity is uncompetitive for its substrates. Data are provided to support the contentions that (i) bovine testis HAse (p55) is a GL-binding protein; and (ii) GL acts as a potent inhibitor of HAse in vitro.

Recent experience of integrated myocardial management: the newest strategy for myocardial protection

From April 1994 until June 1996, we exclusively utilized the integrated myocardial management (IMM) proposed by Buckberg et al. at UCLA. Two hundred sixty-two consecutive patients undergoing open heart surgery at our hospital were divided into 2 groups, the non-IMM (n = 49, from July 1993 until March 1994) and the IMM (n = 213, from April 1994 until June 1996) groups. Although many older and more severely ill patients were treated with IMM, acceptable clinical outcomes with comparable safety and efficiency were obtained. Shorter durations of total cardiopulmonary bypass (CPB) and aortic cross-clamping (AXC) were needed in the IMM group despite there being many more procedures undertaken during a single cross-clamp period.

Identification of human cadherin-14, a novel neurally specific type II cadherin, by protein interaction cloning

Cadherins, a family of Ca2+-dependent cell-cell adhesion molecules, mediate neural cell-cell interactions and may play important roles in neural development. By searching for molecules that interact with beta-catenin, a cytoplasmic regulator of cadherins, we have identified a new member of the cadherin family, which we named human cadherin-14. Cadherin-14 had high amino acid sequence homology with the type II subgroup of cadherins and was broadly expressed in the central nervous system. Cadherin-14 is a novel neurally specific cell-cell adhesion molecule and may regulate neural morphogenesis.

Identification of glycyrrhizin-binding protein kinase as casein kinase II and characterization of its associated phosphate acceptors in mouse liver

Two forms (G-I and G-II kinases) of casein kinase II(CK-II) in a partially purified CK-II fraction (Mono Q fraction) of mouse liver were separated by means of glycyrrhizin (GL)-affinity column chromatography. Biochemical characterization revealed that these two GL-binding kinases were identical to CK-II. Two phosphate acceptors [p99 (pI 7.0) and p56] copurified with CK-II were identified as ERp99 (Hsp-90-family protein) and calreticulin, respectively. Another protein [p100 (pI 9.0)], which crossreacted with anti-serum against human glucocorticoid receptor (GR), was associated with ERp99. Phosphorylation of p99 [a hetero-complex of p99 (pI 7.0) and p100 (pI 9.0)] and p56 by CK-II in vitro was stimulated significantly by low levels (1-3 microM) of GL, but inhibited significantly at doses above 20 microM. However, no effect of GL on autophosphorylation of ERp99 was detected. The data provided here suggest that GL can regulate CK-II-mediated phosphorylation involved in the GL-induced biological effects in mammalian cells.

Physiological correlation between glycyrrhizin, glycyrrhizin-binding lipoxygenase and casein kinase II

By means of glycyrrhizin (GL)-affinity column chromatography, a GL-binding lipoxygenase (gbLOX) was selectively purified from the partially purified soybean LOX-1 fraction. Polypeptide analysis of the purified gbLOX by SDS-PAGE detected two distinct polypeptides (p96 and p94), which were identical to LOX-3 as determined by their partial N-terminal amino acid sequences. Moreover, it was found that (i) phosphorylation of gpLOX by casein kinase II (CK-II) is significantly stimulated by 3 microM GL, but inhibited by 30 microM GL or 10 microM oGA; and (ii) gbLOX activity is enhanced when the enzyme is phosphorylated by CK-II in the presence of 3 microM GL. These results suggest that (i) CK-II is a kinase responsible for the activation of gbLOX through its specific phosphorylation; and (ii) GL is one of the regulatory substances for specific phosphorylation of gbLOX (LOX-3) by CK-II in plant cells.

A 96-kDa glycyrrhizin-binding protein (gp96) from soybeans acts as a substrate for casein kinase II, and is highly related to lipoxygenase 3

A 96-kDa glycyrrhizin (GL)-binding protein (gp96) was purified to apparent homogeneity from an aqueous extract of soybeans by means of successive DEAE-cellulose column chromatography, gel filtration on Superdex 200pg, GL-affinity column chromatography, and ion-exchange chromatography on a Mono S column (HPLC). The protein was identified as a GL-binding protein since it specifically binds to [3H]GA. Moreover, it is a lipoxygenase (an enzyme that catalyzes the oxygenation of unsaturated fatty acids) since (i) it displays lipoxygenase (LOX) activity at pH 6.5; (ii) it is recognized on Western blot analysis by antibodies against LOX-1 and LOX-2; and (iii) the sequence of the N-terminal 21 amino acid residues (SNDVYLPRDEAFGHLKSSDFL) of a 42-kDa fragment (p42) proteolytically generated from gp96 is identical to a sequence of soybean LOX-3. In addition, GL, glycyrrhetinic acid (GA) and soyasaponin beta g slightly inhibited LOX activity of the purified gp96 fraction, whereas oGA (a GA derivative) greatly inhibited its activity. Furthermore, CK-II catalyzed phosphorylation of gp96 was stimulated significantly by GL at doses between 1 and 10 microM, but this phosphorylation was inhibited completely by 50 microM GL. All these results taken together suggest that (i) gp96 purified from soybeans as a GL-binding protein belongs to the LOX family; and (ii) triterpenoid saponins, including GL, are involved in the regulation of the activities of CK-II and LOXs in plants, such as soybeans and roots of liquorice, which contain large quantities of saponins.

Silencing of the E-cadherin invasion-suppressor gene by CpG methylation in human carcinomas

E-Cadherin, a cell adhesion molecule, which plays a key role in maintaining the epithelial phenotype, is regarded as an invasion-suppressor gene in light of accumulating evidence from in vitro experiments and clinical observations. In an attempt to clarify the mechanism responsible for inactivation of this gene in carcinomas, we investigated the methylation state around the promoter region by digestion of DNA with the methylation-sensitive restriction enzyme Hpa II, as CpG methylation of the promoter has been postulated to be a mechanism of transcriptional inactivation of some genes. We found that E-cadherin expression-negative carcinoma cell lines were accompanied by the hypermethylation state, whereas E-cadherin-positive cell lines were not. Furthermore, treatment of E-cadherin-negative carcinoma cells with the demethylating agent 5-azacytidine resulted in reexpression of the gene and reversion of scattered spindle-shaped cells to cells with epithelial morphology. These results suggest that hypermethylation around the promoter may be a mechanism of E-cadherin inactivation in human carcinomas and that treatment of E-cadherin-inactivated cells with a demethylating agent may cause gene expression reversion leading to epithelial morphogenesis with acquisition of the homophilic cell-cell adhesive property.

Isolation and sequence analysis of human cadherin-6 complementary DNA for the full coding sequence and its expression in human carcinoma cells

The expression pattern of E- and P-cadherin in human carcinomas has been reported by many laboratories. However, little is known about the involvement of other cadherin types in human carcinomas. cDNA clones for a cadherin molecule were isolated from a cDNA library of human hepatocellular carcinoma cells which lacked E- and P-cadherin expression but exhibited cell aggregation activity mediated by an unknown cadherin, and they were subjected to sequence analysis. The overlapped clones covered 4315 nucleotides and were found to encode a typical cadherin molecule consisting of 790 amino acids. Since the deduced amino acid sequence was identical to a partially available human cadherin-6 sequence except for two amino acid residues, the clones were considered to be human cadherin-6 cDNAs encoding the entire open reading frame. The deduced amino acid sequence also showed extremely high homology with recently reported rat K-cadherin, 97% for the putative mature protein, suggesting that cadherin-6 is the human counterpart of rat K-cadherin. Expression of cadherin-6 in various human normal tissues and carcinoma cells was examined by Northern blot analysis using a specific probe corresponding to the signal and precursor sequence. Among normal tissues examined, brain, cerebellum, and kidney showed strong expression of cadherin-6, whereas lung, pancreas, and gastric mucosa showed weak expression. Transcripts of cadherin-6 were not detected in normal liver, whereas four of six hepatocellular carcinoma cell lines examined expressed cadherin-6 abundantly. As reported for rat K-cadherin, three renal carcinoma cell lines also expressed cadherin-6 strongly. The most interesting finding was obtained for small cell lung carcinoma lines. Among 15 of such cell lines examined, all of 11 cadherin-6-positive lines were classified into the classic type, whereas the negative cell lines were all of the variant type. The present results suggest that besides E- and P-cadherin, other cadherin molecules are expressed in human cancers and are responsible for additional biological properties of the carcinoma cells.

[Analysis of cases with liver abscess following transcatheter arterial chemoembolization (TAE) for malignant hepatic tumors]

A total of 182 TAE procedures were carried out in 98 patients with malignant hepatic tumors during the last five years. Liver abscess following TAE occurred in 3 cases (3.1%) and in 3 procedures (1.7%). All cases were discharged after successful percutaneous transhepatic abscess drainage. One case had hepatocellular carcinoma. Another case had undergone total gastrectomy and esophagojejunostomy with Roux-Y reconstruction for gastric leiomyosarcoma. The other had undergone right hemicolectomy and pancreatoduodenectomy for colon cancers and carcinoma of the ampulla of Vater. Communication between the abscess and the intrahepatic bile duct was recognized in 2 cases. In the abscess culture, E. coli and Citrobacter freundii were detected. These results suggest the major factor leading to abscess formation is biliary infection. Therefore, a previous bilio-enteric anastomosis should be regarded as a risk factor for liver abscess following TAE.

Frequent loss of alpha catenin expression in scirrhous carcinomas with scattered cell growth

To investigate the mechanisms of disruption of cell-cell contact in scirrhous carcinoma cells, the expression of both E-cadherin and alpha catenin, which is an intracellular cadherin-binding molecule, were determined in scirrhous-type adenocarcinomas of the stomach and breast using immunohistochemical and immunoblotting techniques. The losses of E-cadherin expression in gastric and breast scirrhous adenocarcinomas were 18.1% and 0%, respectively, and those of alpha catenin expression were 54.6% and 75%, respectively. Frequent loss of alpha catenin expression occurred in scirrhous carcinomas with scattered cell growth in the stomach and the breast and showed no organ specificity. In addition, all the infiltrating lobular carcinomas, which also infiltrate the stroma as single cells, showed no E-cadherin or alpha catenin expression. These findings suggest that down-regulation of either alpha catenin or E-cadherin plays a critical role in the disruption of cell adhesion in carcinomas with scattered cell growth.

E-cadherin gene mutations in human gastric carcinoma cell lines

Reduced expression of E-cadherin has been regarded as one of the main molecular events involved in dysfunction of the cell-cell adhesion system, triggering cancer invasion and metastasis. However, even with a sufficient amount of E-cadherin, cell-cell adhesion is sometimes lost in "diffusely invasive" human carcinomas. Ten human cancer cell lines, showing growth characterized morphologically by loose cell-cell adhesion, were analyzed for possible structural abnormalities of their expressed E-cadherin. Four of the cell lines showed strong mRNA and protein expression with no nucleotide sequence abnormalities, and mRNA was absent in four other cell lines. mRNA sequence was abnormal in the remaining two gastric carcinoma cell lines. In MKN45 (poorly differentiated adenocarcinoma), this involved a 12-bp in-frame deletion with strong expression of mRNA and protein. In KATO-III (signet ring cell carcinoma), there were four mRNA species with insertions of different sizes, among which the major transcripts (with a 7-bp insertion) caused a frameshift, and expression of both mRNA and protein was markedly reduced. In these two cell lines, DNA mutations were detected around exon-intron junctions, revealing that aberrant RNA splicing was the cause of the mRNA abnormalities. In addition, the wild-type allele of the E-cadherin locus was lost, suggesting that the E-cadherin gene had been inactivated by two hits (mutation and allele loss), similar to the mechanism for inactivation of tumor suppressor genes.

[Late cardiac tamponade after open heart surgery]

59 cases of late cardiac tamponade following open heart surgery were studied. The incidence was 2.1%. Postoperative prolonged heart failure, anticoagulants, and blood in the pericardium left undrained may play a role in its pathogenesis. Echocardiography was the sure method of diagnosis. Insertion of a drainage tube into the pericardium through the subxiphoid approach was effective with minimal invasion and a treatment of choice.

[Long-term result of surgical patients with ischemic heart disease 70 years of age and older]

This is a report of long-term follow-up of patients 70 years of age and older who underwent operations for ischemic heart diseases. (1) Two of them died in this follow-up period, one due to pneumonia seven months postoperatively, another due to lung cancer 20 months after operation. Actuarial survival rate was 96.8% at one year, 93.3% between two and five years. (2) Event-free rate was 80.6% at one year, 70.1% at two years, and 61.1% between three and five years. (2) Although 21 patients were classified in grade 0 (normal activity) of performance status, seven were classified between grade 2 and 4. We concluded that long-term results were good in surgical patients 70 years of age and older with ischemic heart disease.

Cloning of the human alpha-catenin cDNA and its aberrant mRNA in a human cancer cell line

Cadherin and catenin compose cell adhesion complex and are indispensable for tight cell-cell adhesion. Dysfunction of this adhesion complex causes dissociation of cancer cells from primary tumor nodules, thus possibly contributing to cancer invasion and metastasis. In this report, we present the human alpha-catenin sequence. Human alpha-catenin showed extensive homology with that of mouse, i.e., 91.8% and 99.3% at the nucleic acid and amino acid levels, respectively, indicating that this molecule has been evolutionarily conserved in mammals. Characterization of the mRNA sequence of alpha-catenin in PC9 was also carried out, and two distinct abnormal sequences, i.e., one of 957 bp deletion resulting in a 319-amino-acid deletion and another of 761 bp deletion resulting in a frameshift, were identified. These deletions were probably produced by an error of RNA splicing, presenting one possible mechanism for the loss of intact alpha-catenin expression.

Cadherin dysfunction in a human cancer cell line: possible involvement of loss of alpha-catenin expression in reduced cell-cell adhesiveness

A human lung cancer cell line, PC 9, was analyzed to elucidate the molecular mechanisms of dysfunction of cadherin-mediated cell-cell adhesion in cancer. Although PC 9 cells strongly expressed E-cadherin at the cell membrane, which was indistinguishable immunochemically from functional E-cadherin, they did not show tight cell-cell adhesion and had reduced E-cadherin-mediated aggregation activity. Immunoprecipitation with E-cadherin and Western blot analysis revealed that PC 9 cells did not express alpha-catenin, a cadherin-associated protein, suggesting that this was the cause of the cadherin dysfunction in the cell line. In addition, Northern and Southern blot analyses disclosed homozygous deletion of part of the alpha-catenin gene, which might have resulted in the loss of alpha-catenin expression in PC 9 cells.

Identification of a neural alpha-catenin as a key regulator of cadherin function and multicellular organization

The function of cadherin cell adhesion molecules is thought to be regulated by a group of cytoplasmic proteins, including alpha-catenin. We identified a subtype of alpha-catenin, termed alpha N-catenin, which is associated with N-cadherin and expressed mainly in the nervous system. cDNA transfection experiments showed that alpha N-catenin can also bind with E-cadherin. To investigate the role of alpha N-catenin, we transfected lung carcinoma PC9 cells, which express E-cadherin and beta-catenin but neither alpha- nor alpha N-catenin, with alpha N-catenin cDNA. While parental PC9 grew as isolated cells, the transfectant lines formed aggregates in which cells were tightly adhered to each other, showing epithelial arrangements, and they occasionally gave rise to cystic spheres. These results suggest that alpha N-catenin is crucial not only for cadherin function but also for organization of multicellular structures.

Characterization of high-molecular-mass forms of basic fibroblast growth factor produced by hepatocellular carcinoma cells: possible involvement of basic fibroblast growth factor in hepatocarcinogenesis

Growth factor(s) with a strong mitogenic effect on BALB/c3T3 cells was purified from an extract of C-Li21 cells, a human hepatocellular carcinoma line, by a combination of heparin-affinity chromatography and reversed-phase high-performance liquid chromatography (HPLC). Two major peaks of mitogenic activity were obtained by reversed-phase HPLC. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of the two peaks revealed that one was composed of three proteins with relative molecular masses of 27, 24 and 23 kilodaltons (kD), whereas the other was a single 19-kD protein. Immunoblot analysis showed that all four of these molecules were immunoreactive species of human basic fibroblast growth factor (bFGF). N-Terminal sequence analysis of these molecules revealed that most of them were N-terminally blocked. However, small proportions of the 23- and 19-kD molecules were not blocked, and their respective N-terminal sequences were found to correspond to Gly-40-Gly-27 and Pro29-Phe40 of human bFGF deduced from the cDNA sequence of a human hepatoma cell line, SK-HEP-1. Expression of bFGF in hepatocellular carcinomas was then investigated by RNA blot analysis. All of the examined hepatocellular carcinoma cells expressed bFGF, and the degree of expression was higher in surgically resected hepatocellular carcinomas than in the corresponding adjacent non-cancerous liver tissue. Transcripts of bFGF were not detected in normal liver. These results suggest that C-Li21 cells produce four molecular forms of bFGF, and that bFGF may be involved in hepatocarcinogenesis. Moreover, it appears that bFGF is a potent mitogen toward primary-cultured hepatocytes, and that high-molecular-mass forms of bFGF produced by C-Li21 cells have stronger mitogenic effects on hepatocytes and are more stable under acidic conditions than the low-molecular-mass form, composed of 146 amino acids.

Newly established uterine cervical carcinoma cell line with co-amplification of human papillomavirus DNA and c-myc gene

A new human tumor cell line, NCC-c-CX-1 (CX-1), was established from a uterine cervical cancer xenografted in nude mice. This cell line harbored approximately 50 to 100 copies of human papillomavirus (HPV) type 18 DNA per haploid genome, and contained about 16-fold-amplified c-myc gene with rearrangement. These genomic alterations found in CX-1 cells were also present in both primary tumor and xenografted tumor. Histopathologically, original and xenografted tumors were poorly differentiated cancer and were characterized by neuroendocrine features such as positive neuron-specific enolase and chromogranin A by immunohistochemistry and abundant neurosecretory-type granules in the cytoplasm by electron microscopy. However, the established cell line had lost the neuroendocrine features. This cervical cancer cell line may be a useful model for studying cervical carcinogenesis, especially the interaction between HPV and c-myc oncogene.