Murine interleukin 4 transgenic heart allograft survival prolonged with down-regulation of the Th1 cytokine mRNA in grafts

BACKGROUND

Data supporting the differential activation of T helper (Th) 2 cells in transplantation acceptance/tolerance in rodents have been presented by several investigators. However, the differential activation of Th2 cells may be simply the result of allograft acceptance/tolerance induction instead of a contribution to the maintenance of grafts.

METHODS

Therefore, we established interleukin (IL)-4 transgenic mice under the control of a cardiac alpha-myosin heavy chain promotor and transplanted IL-4-expressing heart allografts into unmodified recipients to determine the actual contribution of the Th2 bias to allograft acceptance.

RESULTS

Among 16 newborn C57BL/6J (B6) mice, three were positive for the IL-4 transgene. Serum IL-4 levels of transgenic versus control B6xC3H F1 mice were not statistically different. Reverse-transcriptase polymerase chain reaction showed that the transgenic B6xC3H F1 mice expressed IL-4 mRNA in the heart and in the lung, whereas control mice did not express IL-4 in any organ. IL-4 mRNA expression in the transgenic but not in the control heart was also confirmed by RNAse protection assay and fluorescence in situ hybridization. The survival of IL-4 transgenic B6xC3H heart grafts heterotopically placed in C3H recipients was prolonged compared with that of nontransgenic grafts (19.0+/-9.1 vs. 6.8+/-2.2 days, P=0.003). Interferon-gamma mRNA expression in IL-4 transgenic heart grafts on the fifth posttransplant day as assessed by Northern blotting was suppressed compared with that in control grafts. Reverse-transcriptase polymerase chain reaction analysis showed that IL-2 mRNA was suppressed in the IL-4 transgenic grafts compared with that in control grafts, while IL-4 mRNA was observed only in IL-4 transgenic grafts. IL-10 mRNA was detected at similar levels in both transgenic and control grafts.

CONCLUSIONS

A Th2 bias may contribute to allograft acceptance in part by inducing the down-regulation of Th1-cytokine mRNAs, but it may not be sufficient to induce indefinite graft survival.

Dynamic MRI of the gallbladder lesions: differentiation of benign from malignant

Forty-nine pathologically proven gallbladder lesions were evaluated in 45 patients using dynamic MRI with a spoiled gradient pulse sequence (SPGR), to access the ability of this technique to differentiate benign from malignant gallbladder lesions. The studies were reviewed retrospectively. Signal intensity of the lesions were measured. Twenty-one malignant and 28 benign lesions were classified into three categories: polypoid, diffuse wall thickening, and exophytic. Early and delayed enhancement patterns were evaluated. For the polypoid masses, malignant lesions (n = 9) demonstrated early and prolonged enhancements, whereas benign lesions (n = 14) had early enhancement with subsequent washout (P < .05). For diffuse gallbladder wall thickening, malignant lesions (n = 6) demonstrated early and prolonged enhancement and benign lesions (n = 14) showed relatively slow, prolonged enhancement (P < .05). The exophytic masses (n = 6) all were malignant and demonstrated early and prolonged enhancement. Dynamic MRI can help differentiate benign from malignant gallbladder lesions.

Inhibition of thymocyte apoptosis by berberine

To find anti-apoptotic substances in plant resources, a microassay method for estimating DNA fragmentation was established using fluorochrome 3,5-diaminobenzoic acid dihydrochloride. Examination was made of various herbal medicines for inhibitory effects on glucocorticoid-induced apoptosis in thymocytes. Several Kampo medicines, e.g. Oren-gedoku-to and San'o-shashin-to, were found to inhibit dexamethasone-induced apoptosis in murine thymocytes. Some of these medicines contain Coptidis rhizoma (CR) as the major constituent, and the CR extract showed the most potent inhibitory activity on thymocyte apoptosis of more than 200 species of herbal extracts. The inhibition of apoptosis by CR extract was confirmed by the trypan blue exclusion test, lactate dehydrogenase release measurement, and morphological evaluation by electron microscopy. The benzodioxolo-benzoquinolizine alkaloid, berberine, and five berberine-type alkaloids, isolated from CR extract, had an inhibitory effect, whereas no effect was noted for the aporphin-type alkaloid magnoflorine. The inhibitory action of berberine was also demonstrated on etoposide- and camptothecin-induced apoptosis.

Expression of hepatocyte growth factor and its receptor c-met proto-oncogene in hepatocellular carcinoma

The c-met proto-oncogene encodes the tyrosine kinase receptor for hepatocyte growth factor (HGF), a potent mitogen and motogen for epithelial cells. Because of its profound effects on cell growth and motility, HGF may be important in the development of cancer metastases in hepatocellular carcinoma (HCC). In this study, we examined HGF concentration and expression of the c-met-proto-oncogene product (c-met) in 62 patients with HCC to determine the relationship between the level of expression and clinicopathological features, and patient outcome following hepatectomy. Western blotting was used to examine the c-met expression, and HGF concentration in tumors was measured using an enzyme-linked immunosorbent assay. c-met was found to be overexpressed in HCC compared with nontumorous liver tissue (P < .01), and correlated with an increased incidence of intrahepatic metastases (P = .039). Patients were divided into two groups, low c-met HCC and high c-met HCC. Patients with high c-met HCC had a significantly shorter 5-year survival than patients with low c-met HCC (33.5% vs. 80.3%, respectively; P < .05). However, there was no correlation between HGF concentration in the tumor tissue and clinicopathological factors and patient survival. These results indicate that expression of c-met played an important role in tumor growth and metastases in patients who underwent hepatectomy for HCC.

Reflection-wavelength control method for layer-by-layer controlled x-ray multilayer mirrors

A reflection-wavelength control method for a layer-by-layer controlled x-ray multilayer mirror without interface roughness is proposed. The reflection wavelength of the multiperiodic mirror is found to be simply determined by a combination ratio of periodic layers. Multiperiodic x-ray mirrors with reflectance wavelengths at 3.374 nm (C VI 1s-2p) and 3.950 nm (Ca XVIII 3d-5f) are successfully designed.

Expression of hepatocyte growth factor and its receptor, the c-met proto-oncogene, in hepatocellular carcinoma

The c-met proto-oncogene encodes the tyrosine kinase receptor for hepatocyte growth factor (HGF), a potent mitogen and motogen for epithelial cells. Because of its profound effects on cell growth and motility, HGF may be important in the development of cancer metastases in hepatocellular carcinoma (HCC). In this study, we examined HGF concentration and expression of the c-met proto-oncogene product (c-Met) in 62 patients with HCC to determine the relationship between the level of expression and clinicopathological features, and patient outcome following hepatectomy. Western blotting was used to examine the c-Met expression, and HGF concentration in tumors was measured using an enzyme-linked immunosorbent assay. c-Met was found to be overexpressed in HCC compared with nontumorous liver tissue (P < .01), and correlated with an increased incidence of intrahepatic metastases (P = .039). Patients were divided into two groups: low c-Met HCC and high c-Met HCC. Patients with high c-Met HCC had a significantly shorter 5-year survival than patients with low c-Met HCC (33.5% vs. 80.3%, respectively; P < .05). However, there was no correlation between HGF concentration in the tumor tissue and clinicopathological factors and patient survival. These results indicate that the expression of c-Met played an important role in tumor growth and metastases in patients who underwent hepatectomy for HCC.

Expression of hepatocyte growth factor and its receptor, the c-met proto-oncogene, in hepatocellular carcinoma

The c-met proto-oncogene encodes the tyrosine kinase receptor for hepatocyte growth factor (HGF), a potent mitogen and motogen for epithelial cells. Because of its profound effects on cell growth and motility, HGF may be important in the development of cancer metastases in hepatocellular carcinoma (HCC). In this study, we examined HGF concentration and expression of the c-met proto-oncogene product (c-Met) in 62 patients with HCC to determine the relationship between the level of expression and clinicopathological features, and patient outcome following hepatectomy. Western blotting was used to examine the c-Met expression, and HGF concentration in tumors was measured using an enzyme-linked immunosorbent assay. c-Met was found to be overexpressed in HCC compared with nontumorous liver tissue (P < .01), and correlated with an increased incidence of intrahepatic metastases (P = .039). Patients were divided into two groups: low c-Met HCC and high c-Met HCC. Patients with high c-Met HCC had a significantly shorter 5-year survival than patients with low c-Met HCC (33.5% vs. 80.3%, respectively; P < .05). However, there was no correlation between HGF concentration in the tumor tissue and clinicopathological factors and patient survival. These results indicate that the expression of c-Met played an important role in tumor growth and metastases in patients who underwent hepatectomy for HCC.

Significance of the expression of proliferation-associated nucleolar antigen p120 in human colorectal tumors

Nucleolar protein p120 is considered to be associated with cell proliferation and has also been detected in a broad range of human malignant cells and tissues, but not in either normal resting tissue or most benign tumors. To clarify the significance of the expression of p120 in colorectal tumors or to evaluate the contribution of p120 in the development of colorectal carcinoma, the authors developed a monoclonal antibody against p120 and then examined its expression in adenoma, carcinoma, and normal mucosa. In adenomas, p120 expression was shown in none of 13 cases of mild dysplasia (0%), 2 of 15 of moderate dysplasia (13.3%), and in 2 cases of severe dysplasia (100%). p120-positive adenomas of moderate dysplasia tended to be larger and had higher Ki-67 indexes than the negative ones (adenomas of moderate dysplasia). All 27 carcinomas were positive for p120. p120 immunostaining was found in the nuclei and corresponded closely to the prominent nucleoli of tumor cells. In contrast, either weak or the occasional expression of p120 was traced in only one of the nine normal mucosae (11.1%). Three of the transitional mucosae of the carcinoma were also positive for p120. The percentage of p120-positive tumor cells (p120 index) ranged from 3.2% to 86.6%, and the mean p120 indexes of the four adenomas and all carcinomas were 21.3% and 41.5%, respectively. The p120 index was significantly related to the Ki-67 index (P < .001) in the p120-positive tumors, whereas the p120 index of the carcinoma did not significantly correlate to the known prognostic markers, such as tumor size, stage, or the degree of differentiation. These results thus suggest that the expression of p120 serves as a marker for cells with a high proliferative potential and is linked to the late events of colorectal tumor progression.

Th2-like response and antitumor effect of anti-interleukin-4 mAb in mice bearing renal cell carcinoma

Tumor regression in experimental systems has been linked to the activities of Th1 cells. It is, therefore, conceivable that Th2 cells interrupt the expression of tumor immunity since interleukin-4 (IL-4) and IL-10 inhibit the generation of Th1 from precursors and modulate the competence of antigen-presenting cells to activate this lymphocyte subpopulation. Naive murine renal cell carcinoma (renca) cells (1 x 10(5)) were implanted into the subcapsule of the left kidney of Balb/c and Balb/c nude mice at 6-8 weeks of age. After 14 days, Th2 cytokine (IL-4 and IL-10) mRNAs as well as transforming growth factor beta1 mRNA, assessed by reverse transcriptase/polymerase chain reaction were upregulated in the spleen of hosts upon naive renca tumor acceptance, while Th1 cytokine (IL-2 and interferon gamma) mRNAs were almost undetectable. In the renca tumor, IL-10 mRNA was detected but IL-2, interferon gamma, and IL-4 were not. Intraperitoneal administration of anti-(mouse IL-4) mAb (11B11) reduced the renca tumor size (P = 0.018) and prolonged host survival (P = 0.03), but did not reduce the acceptance rate of the tumor (P = 0.18). However, prior depletion of CD4+ or CD8+ cells with monoclonal antibodies abrogated the antitumor effects of anti-IL-4 mAb. In addition, the significant antitumor effect of anti-IL-4 mAb was not observed in Balb/c nude hosts. Renca cells were transfected with the mammalian expression vector pCAGGS containing murine IL-4 cDNA or vector alone, then stable IL-4 transfectants (RencaL or RencaH, low- or high-IL-4-producing respectively) and control renca cells (RencaC) were obtained. RencaL cells, RencaH cells, or RencaC cells (1 x 10(5) each) were implanted into the subcapsule of the left kidney of Balb/c, Balb/c nude, and allogenic C3H/HeJ mice, then tumor formation was evaluated 14 days later. When RencaH cells were innoculated into syngeneic Balb/c hosts, tumor volume was marginally suppressed (P = 0.03) and tumors tended to be rejected (P = 0.06) compared with RencaC cells. However, those effects were not observed in Balb/c nude mice. RencaC, RencaL, and RencaH cells were not accepted by allogeneic C3H mice with or without FK506 administration or donor-specific transfusion. The administration of anti-(mouse IL-4) mAb to Balb/c mice significantly suppressed renca tumor growth by a CD4+ and CD8+ T-cell-dependent mechanism. By contrast, relatively high levels of IL-4 production by renca cells and T cells seemed to be required to induce the rejection and growth suppression of IL-4-producing renca cells in syngeneic hosts.

Positive-negative KG cassettes for construction of multi-gene deletions using a single drug marker

Positive-negative KG cassettes were developed in order to create a number of independent deletion mutations on the bacterial chromosome using a single drug marker. These cassettes consist of a kanamycin-resistant (KmR) gene for positive screening and a galactokinase gene (galK) for negative screening. Both genes are in an operon driven by the native KmR promoter and are flanked by identical fragments of yeast chromosomal DNA approximately one kb in size. An internal region of a cloned target gene of a bacterium is replaced with a cassette, which is then transformed into the bacterium. The intact gene on the chromosome is replaced with the mutated gene by homologous recombination. From the KmR cells thus obtained, those cells which lose both KmR and galK genes by homologous recombination between the identical yeast DNA fragments are subsequently screened on plates containing 2-deoxygalactose, a non-metabolizable analogue of galactose. This method was applied to isolate a triple-deletion mutant of pkn3, pkn1, and pkn11 from Myxococcus xanthus.

Modulation of growth and apoptosis response in PC-3 and LNCAP prostate-cancer cell lines by Fas

Fas/APO-1 is a cell-surface protein, a member of the TNF-receptor family, and it potentially induces apoptosis. In presence of an apoptosis-inducible anti-human Fas MAb, Fas-negative control PC-3 human prostate-cancer cells did not undergo morphological changes, while PC-3 human Fas transfectants showed apoptotic changes in vitro. However, LNCaP human Fas transfectants, as well as Fas-negative control LNCaP human prostate-cancer cells, were Fas-resistant. The growth of Fas-transfected PC-3 tumor was retarded compared with that of control PC-3 tumor in vivo without stimulation of anti-human Fas MAb. Anti-human Fas MAb administration in vivo caused macroscopic Fas-transfected PC-3 tumors formed in BALB/c nude mice to undergo apoptosis.

[Three-dimensional-CT pancreatography under balloon-ERP in the pancreatic diseases--its method and usefulness]

Three-dimensional-CT pancreatography (3D-CTP) under balloon-ERP was carried out in 13 patients with the pancreatic diseases. Tapering stenosis of pancreatic duct in 2 patients out of 2 with pancreatic cancer, shape of cyst and relationship between cyst and pancreatic duct in 7 patients out of 7 with pancreatic cysts, and irregularity of wall of pancreatic duct in 2 patients out of 3 with chronic pancreatitis was reconstructed by 3D-CTP, stereographically. Moreover, the confluence of cyst and pancreatic duct in 3 out of 7 pancreatic cysts did not become clear on balloon-ERP, but it was distinct on 3D-CTP. It is suggested that 3D-CTP is useful in understanding pancreatic diseases stereographically, and can be applied to operative simulation, interventional radiology and differential diagnosis on them.

Enhanced expression of hepatitis B surface antigen by sodium butyrate in PLC/PRF/5 human hepatoma cells

The effect of butyric acid, a natural fermentation product of colonic bacterial flora, on hepatitis B surface antigen (HBsAg) expression was investigated in HBsAg-positive PLC/PRF/5 human hepatoma cells. By Northern blot analysis, the levels of HBsAg mRNA increased dose-dependently using sodium butyrate (0-2 mmol/l). In transient chloramphenicol acetyltransferase plasmid transfection experiments, the HBsAg-preS2 promoter activity as well as the HBV enhancer 1 activity was stimulated by sodium butyrate, whereas the HBsAg-preS1 promoter activity was not. These results indicate that butyric acid functions as a physiological regulator of HBsAg expression through the portal blood flow and possibly contributes to increased expression ratio of preS2/S to preS1 polypeptides recognized in persistant HBV infection.

Cryocrystallography of 3-Isopropylmalate Dehydrogenase fromThermus thermophilusand its Chimeric Enzyme

The crystal structures of thermostable enzyme, 3-isopropylmalate dehydrogenase of Thermus thermophilus (10T) and a chimeric enzyme between T. thermophilus and Bacillus subtilus with one point mutation (cS82R), were determined at both 100 and 150 K. At the cryogenic condition, the volume of the unit cell decreased by 5% as a result of a contraction in the solvent region. Although the overall structures of both enzymes at low temperature were the same as that of 10T at room temperature, interactions between two domains and between two subunits in a functional dimer of cS82R were significantly altered. The decrease in the average temperature factor of 10T at low temperature and no significant decrease for cS82R suggested that the structure of the engineered enzyme (cS82R) may have many conformational substates even at low temperature, while the native enzyme (10T) at low temperature has a more definite conformation than that at room temperature. The location of water molecules around the enzyme molecule and the calculation of the radii of gyration suggested that cS82R had a weaker hydration than 10T.

Fluorescence polarization study on the dynamics and location of peroxidized fluorescent phospholipids in liposomes

Motional properties of fluorescent substances produced by lipid peroxidation by a time-resolved fluorescence polarization technique were studied. When liposomes containing phosphatidylethanolamine (PE) and linoleic hydrocarbon chain were incubated at 37 degrees C, fluorophores absorbing maximally at 360 nm and emitting near 430 nm were produced. Their fluorescence anisotropy decay measured at 23 degrees C was fitted well with a sum of a fast relaxation and a time-independent residual term. With the increase of oxidation degree, the time constant of the relaxation term increased. This may be explained by alteration in the membrane structure or by modification of the fluorescent products themselves. Information on the location of the fluorescent products was obtained when their motional property was compared with those of various extrinsic probes that were incorporated at different positions of the lipid bilayer. It was found that the motional property of the fluorescent oxidation products is similar to that of 1-(4-trimethylammoniumphenyl)-6-phenyl-1,3,5-hexatriene, a rod-shaped hydrophobic probe with a charged terminal. Other probes sensing the polar region or the hydrophobic region of the membrane were characterized by a lower order parameter. It is suggested that the fluorescent oxidation products have a polar moiety located at the membrane surface and attached to the amino group of PE while the tail part being buried in the hydrophobic region of the membrane. This picture is supported by fluorescence quenching experiments with the aqueous quencher Co2+. On the other hand, fluorophores produced by the reaction of malondialdehyde and PE suggested to have a chemical structure in which the angle between the absorption and emission dipole moments is very large. On the basis of these observations, the production pathway of fluorophores in oxidized membranes is discussed.

Molecular cloning and characterization of a newly identified member of the cadherin family, PB-cadherin

We have isolated cDNA clones encoding novel proteins belonging to the cadherin family. These novel proteins are encoded by two distinct mRNA species generated by alternative splicing from a single gene, and based on preferential expression in the pituitary gland and brain, we named it PB-cadherin. One mRNA species encodes long type PB-cadherin composed of 803 amino acid residues with a longer cytoplasmic domain, whereas the other species encodes short-type PB-cadherin composed of 694 amino acid residues with a shorter cytoplasmic domain. Both long and short type PB-cadherin contain five repeats of a cadherin motif in the extracellular domain, the transmembrane domain, and the cytoplasmic domain, and the deduced amino acid sequences have a 30% homology to those of E-, N-, and P-cadherins. Although the primary structure of N-terminal amino acids is identical between long and short type PB-cadherin, the following structures in the cytoplasmic regions are completely different. The long type PB-cadherin but not the short type contains the putative catenin-binding domain. When these two distinct forms of PB-cadherins were stably expressed in L cells, L cells expressing long type PB-cadherin or short type PB-cadherin both acquired a Ca2+-dependent cell adhesion property, thereby indicating that both types of PB-cadherin are responsible for Ca2+-dependent cell adhesion. Persistent expression of PB-cadherin mRNA was found in the brain of rat embryos at least from embryonic day 15 to the postnatal period. In situ localization of PB-cadherin mRNA in the adult rat brain indicated that PB-cadherin mRNA is expressed in the inner granular layer of the olfactory bulb, Purkinje cell layer of the cerebellum, and in the pineal gland. PB-cadherin may play an important role in morphogenesis and tissue formation in neural and non-neural cells for the development and maintenance of the brain and neuroendocrine organs by regulating cell-cell adhesion.

Distribution of activated complement, C3b, and its degraded fragments, iC3b/C3dg, in the colonic mucosa of ulcerative colitis (UC)

The third component of complement (C3) is central to both the classical and alternative pathways in complement activation. In this study, involvement of C3 activation in the mucosal injury of UC was investigated. We examined the distribution of activated (C3b) and degraded fragments (iC3b/C3dg) of C3, terminal complement complex (TCC), and complement regulatory proteins in normal and diseased colonic mucosa including UC and other types of colitis using immunohistochemical techniques at the level of light and electron microscopy. While C3b and iC3b/C3dg staining was negligible in the normal mucosa, iC3b/C3dg and, to a lesser extent, C3b were deposited in UC mucosa along the epithelial basement membrane. The deposition was enhanced in relation to the severity of mucosal inflammation (C3b, P less than 0.05; iC3b/C3dg, P less than 0.01). Epithelial deposition of TCC was not observed in most UC mucosa. Immunoelectron microscopy showed that C3b and iC3b/C3dg were distributed mainly along the epithelial basement membrane and the underlying connective tissue in a granular, studded manner, and weakly present along the basolateral surface of epithelial cells. These C3 fragments were also deposited in inflammatory control mucosa such as ischaemic and infectious colitis. Our findings suggest that deposition of the C3 fragments occurs in inflamed colonic mucosa of diverse etiologies, including UC, but to define a role of the deposition in the development of mucosal injury in UC awaits direct study.

[Urothelial carcinoma of the navicular fossa]

We report a case of transitional cell carcinoma arising in the fossa navicularis. The patient was a 74-year-old man. He had no history of sexually transmitted disease or urethral stricture. Clinically, the tumor was suspected to be a condyloma acuminatum; however, the pathological diagnosis yielded an unexpected result: transitional cell carcinoma. Radiological examinations and cystoscopy showed no other tumor besides the primary cancer in the fossa navicularis. Partial resection of the urethra was performed and the patient has been without evidence of disease for 3 years.

Astrocytic contributions to blood-brain barrier (BBB) formation by endothelial cells: a possible use of aortic endothelial cell for in vitro BBB model

Astrocytic contribution of endothelial cell monolayer permeability was examined in two blood-brain barrier (BBB) models, using the coculture in a double chamber system: rat astrocytes and bovine aortic endothelial cells (BAECs) or bovine brain endothelial cells (BBECs). In system 1, where astrocytes were separated from endothelial cells, a 40% reduction in L-glucose permeability of the BBEC monolayer, but not the BAEC monolayer, was observed by cocultivation with astrocytes. Although several passages of BBEC in culture elicited morphological transformation from spindle-shapes to cobblestone-like features, the passaged BBECs remained responsive to astrocytes in coculture in system 1 (37% reduction of the L-glucose permeability). By contrast, in system 2, where respective endothelial cells and astrocytes layered on the upper and lower surfaces of a membrane, the permeability of both BAEC and BBEC monolayers was reduced by cocultivation with astrocytes (75% reduction for BAEC and 40% reduction for BBEC). BAECs in this contiguous coculture (system 2) with astrocytes showed numerous tight junction-like structures characteristic of the BBB in vivo. These results suggest that primary cultured BBECs, which had been primed by astrocytes in vivo, retain a higher sensitivity to astrocytes possibly through an astrocytic soluble factor (s) to exhibit BBB-specific phenotypes, and that even BAEC from extra-neural tissues, when cultured with astrocytes in close proximity in vitro, may acquire the similar phenotypes and serve for an extensive use of BBB model in vitro.

Crystal structure of H2-proteinase from the venom of Trimeresurus flavoviridis

The crystal structure of the zinc-protease, H2-proteinase, isolated from the venom of Trimeresurus flavoviridis has been determined. The crystallographic R factor is 0.176 for 10,635 reflections with Fobs > 2sigma(Fobs) in the 8.0 to 2.2 Angstrom resolution range. The enzyme has two domains with a cleft in which a catalytic zinc atom is located. The N-terminal domain is composed of four helices around a central five-stranded beta-sheet. The irregularly folded C-terminal domain contains one helix and two disulfide bridges. These two domains are linked by a disulfide bridge. In the zinc environment, the catalytic zinc atom forms a distorted tetrahedral coordination with three histidines and one catalytic water molecule, and the methionine-containing turn is structurally conserved. These are distinctive features of the metzincins, one of the zinc metalloprotease superfamilies. The entire structure shows good agreement with that of two Crotalus snake venom proteases, adamalysin II and atrolysin C. The H2-proteinase, however, contains no structural calcium ions, and differences of disulfide configurations and the coordination of the catalytic water molecule exist as compared with the other two proteases.

Expression of basic fibroblast growth factor and fibroblast growth factor receptor in advanced gastric carcinoma

The expression of basic fibroblast growth factor (bFGF) and fibroblast growth factor receptor (FGFR) mRNA was examined in gastric carcinomas by immunohistochemistry and in situ hybridization, respectively. In the 20 advanced carcinomas examined, bFGF was found in 14 (70.0 per cent) and was confined to the tumour cells, whereas FGFR mRNA was demonstrated in 12 (60.0 per cent) and seen in both tumour cells and endothelial cells. The bFGF and FGFR mRNA-positive carcinomas were larger, were more frequently classified as undifferentiated adenocarcinoma, more frequently invaded the serosal layer, and had a higher rate of lymph node metastases than the bFGF and FGFR mRNA-negative carcinomas. Patients with bFGF and FGFR mRNA-positive carcinomas appear to die earlier than those with bFGF and FGFR mRNA-negative tumours. The values for the carcinomas that were positive for either bFGF or FGFR mRNA fell between these two groups. The findings suggest that the autocrine/paracrine bFGF/FGFR channel is associated with undifferentiated gastric carcinomas and may lead to a poorer prognosis.

Detection of decay-accelerating factor in stool specimens of patients with colorectal cancer

BACKGROUND & AIMS

Colorectal cancers have an increased expression of decay-accelerating factor (DAF). The aim of this study was to determine whether stool specimens of patients with colorectal cancer contain increased amounts of DAF.

METHODS

DAF was measured using an immunoassay in the stool specimens of 40 persons with colorectal cancer, 18 with colorectal adenomatous polyps, 13 with upper gastrointestinal cancer, and 41 without gastrointestinal disease.

RESULTS

Stool DAF concentrations in patients with colorectal cancer (0-9.8 ng/g stool; median, 1.6 ng/g) were significantly higher than those in patients with adenoma (0-6.4 ng/g; median, 0 ng/g) (P < 0.05), patients with upper gastrointestinal cancer (0-3.1 ng/g; median, 0 ng/g) (P < 0.05), and subjects without gastrointestinal disease (0-3.4 ng/g; median, 0 ng/g) (P < 0.01). Resection of colorectal cancers caused a marked decrease in stool DAF concentrations. The stool DAF test was positive in a substantial portion of patients with colorectal cancer whose tumors were small ( < 2 cm), at an early TNM stage, or unassociated with fecal occult blood positivity. The sensitivity of the test for colorectal cancer was 55%, and the specificity was 85%.

CONCLUSIONS

The measurement of stood DAF deserves evaluation as a test for detection of colorectal cancer.

Dispersion state of phospholipids and fluorescence production with peroxidation in organic solvents: investigated by time-resolved fluorescence technique

Fluorescent substances were found to be produced efficiently when phospholipids containing phosphatidylethanolamine (PE) and linoleic chains were autoxidized in non-polar solvents. By using these fluorescent substances as intrinsic probes, the dispersion state of phospholipids was investigated in various organic solvents. Fluorescence anisotropy decay measurements indicated that the aggregation size of phospholipids was much larger in hexane than in chloroform, methanol and tert-butyl alcohol. The average diameter of phospholipid aggregates in hexane was calculated to be 4-6 nm, which was dependent on the lipid composition. A consistent result was obtained when N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)-1,2-dihexadecanoyl-sn-gly cer o-3- phosphoethanolamine (NBD-PE) was used as an extrinsic probe. Comparison of the fluorescence data with small-angle X-ray scattering (SAXS) data suggested that a reverse micellar structure of phospholipids formed in hexane. It was shown that phospholipid aggregation enhanced the extent of peroxidation as well as the production yield of fluorescent substances of phospholipid.

A new type of Streptomycete arylsulfatase with high affinity to the sulfuryl moiety of the substrate

Streptomyces sp. T109-3 arylsulfatase (Es-2), which desulfated p-nitrophenyl sulfate as well as etoposide 4'-sulfate, was purified to protein homogeneity by sulfated cellulose affinity and DEAE-cellulose column chromatographies. Es-2 required calcium for enzyme activity and was severely inhibited by SH and chelating reagents. Comparative characterization showed that, although distinct in recognition of the binding moiety of substrate, Es-1 (Streptomyces griseorubiginosus S980-14 arylsulfatase) and Es-2 shared high desulfating activity on etoposide 4'-sulfate and many other common enzymological characteristics, which suggested they would be acceptable as the enzyme component of antitumor antibody-enzyme conjugates for target chemotherapy.

Screening and production of arylsulfatases for target therapy with etoposide 4'-sulfate, an antitumor prodrug

Two arylsulfatase-producing streptomycetes that desulfated etoposide 4'-sulfate were isolated from soil samples. Taxonomical study identified one soil isolate as Streptomyces griseorubiginosus S980-14 (Es-1 arylsulfatase producer), while the other was considered new and tentatively designated Streptomyces sp. T109-3 (Es-2 arylsulfatase producer). Both strains produced extracellular arylsulfatase activities, provided that cultivation media were prepared with distilled water. Unlike the two known types of arylsulfatases, which had significant activity on p-nitrophenyl sulfate but none on etoposide 4'-sulfate, the crude streptomycete arylsulfatases efficiently desulfated etoposide 4'-sulfate and p-nitrophenyl sulfate, which supports the establishment of a new type of arylsulfatases.

Expression of ICAM-I on M cells covering isolated lymphoid follicles of the human colon

To clarify the immunological function of 'M' (microfold or membranous) cells in the large intestine, we examined the expression of intercellular adhesion molecule-1 (ICAM-1) and HLA-class II antigens immunohistochemically in M cells and follicle-associated epithelia (FAE) covering isolated lymphoid follicles of the human colon in comparison with their expression in Peyer's patches of the small intestine. In Peyer's patches of the small intestine, ICAM-1 was not expressed on the epithelial cells covering the lymphoid follicles, but their cell surfaces were stained positively for HLA-DR. In contrast, colonic M cells expressed ICAM-1 on their cell surfaces but were negative for HLA class II antigens. By immunoelectron microscopy, ICAM-1 was seen to be distributed on the surface of microfolds, on the membranes of apical vesicles and on part of the basolateral plasma membranes of M cells, but was not expressed on adjacent FAE. These findings imply that the M cells in the colon and in Peyer's patches have different immunological roles. In addition, identification of ICAM-1 expression on the colonic M cells should help elucidate the pathogenesis of some inflammatory colonic diseases which appear to start in the lymphoid follicles of the colonic mucosa.

Susceptibility for hydroperoxide formation of phosphatidylcholine and phosphatidylethanolamine in liposomes

To compare the peroxidative susceptibilities of phosphatidylcholine (PC) and phosphatidylethanolamine (PE) in liposomes, multilamellar vesicles (MLVs) were prepared with equimolar L-alpha-dilinoleoyl PC (DLPC) and L-alpha-dilinoleoyl PE (DLPE), and with soya PC and soya PE having a uniform constituent fatty acids. The hydroperoxide formation at 37 degrees C in the presence of a water-soluble radical initiator was examined by chemiluminescence-high-performance liquid chromatography (CL-HPLC), and the effect of heterogeneous distribution of PC and PE on peroxidation was investigated. No difference was found between the hydroperoxidation of PC and PE in MLVs systems, except that soya PC was more susceptible to peroxidation than soya PE in the L-alpha-dipalmitoyl PC (DPPC)-based liposomes. No correlation was found between the amount of phospholipids distributed in the external leaflet of MLVs and hydroperoxide formation. This result suggested that the unsaturation of constituent fatty acids in phospholipids is more important than the difference in the polar head group of phospholipids regarding their peroxidizabilities in liposomes.

Arylsulfatase from Streptomyces griseorubiginosus S980-14

A new arylsulfatase designated Es-1, which desulfated etoposide 4'-sulfate and p-nitrophenyl sulfate, was isolated from Streptomyces griseorubiginosus S980-14 and purified to protein homogeneity by ammonium sulfate fractionation, ion exchange column chromatography, and chromatofocusing. The enzyme was active in monomeric form with an approximate molecular weight of 45,000, had a pI value of 4.95, and required calcium for full activity. At an optimum reaction pH of 8.5, iodoacetate, mercurous chloride, and EDTA severely inhibited the activity of Es-1 arylsulfatase.

Structural characterization of the molten globule and native states of apomyoglobin by solution X-ray scattering

Compactness and shape are two of the critical properties that describe the degree of protein folding. Solution X-ray scattering is an effective technique for measuring these properties quantitatively. Structural characteristics of various conformational states of horse myoglobin were studied in terms of size and shape by solution X-ray scattering. The radius of gyration for native holomyoglobin was 17.5 A, while that of the apomyoglobin native state was 19.7 A. Corresponding to the increase in the radius of gyration, the largest dimension of the molecule also increased from 47.5 A to 62.5 A. Both states are globular in shape. The scattering profiles in the high angle region suggest that the apomyoglobin native state has a distinct tertiary structure, and that packing of alpha-helices in the apomyoglobin native state would be looser than that of holomyoglobin. These observations indicate that the native state of apomyoglobin is expanded from that of holomyoglobin, and that the conformations of the two are not identical. The radii of gyration for the acid-unfolded state and the denaturant-unfolded state were 30 A and 35 A, respectively. Both unfolded states have chain-like conformations without any tertiary structures. The radius of gyration and the largest dimension of the molten globule stabilized by trichloroacetate were 23.1 A and 72.5 A, respectively. The molten globule is expanded from the native state although it is globular, and is much more compact than the unfolded state. The bimodal distance distribution function and scattering profile at high-angle region suggest that the structure of the apomyoglobin molten globule contains a core comprising a cluster of multiple alpha-helices and flaring tail(s), which would be a common structural property of the compact denatured state appearing during the folding process. The compactness of each conformational state is highly correlated with the extent of formation of the alpha-helix.

Intraductal papillary mucinous neoplasms of the pancreas associated with so-called "mucinous ductal ectasia". Histochemical and immunohistochemical analysis of 29 cases

Twenty-nine patients (20 men, nine women; mean age, 65.9 years; range, 49-77 years) with intraductal papillary mucinous neoplasms associated with so-called "mucinous ductal ectasia" of the pancreas were studied both histochemically and immunohistochemically. These cases included six cases of hyperplasia, 13 adenomas, and 10 adenocarcinomas. The mean sizes of the hyperplasia, adenomas, and adenocarcinomas were 2.0 cm, 3.0 cm, and 4.8 cm in diameter, respectively. Tumor size correlated with the degree of cellular atypia. The proliferative rates were significantly higher in the carcinomatous epithelium with those in the hyperplastic and adenomatous epithelia. The polarity of distribution of carcinoembryonic antigen and carbohydrate antigen 19-9 were better preserved in the hyperplastic epithelia than in the carcinomatous epithelia. On the other hand, the papillary and nonpapillary hyperplastic epithelium contained mainly a neutral periodate-reactive glycoprotein with only trace amounts of sialomucins and sulphomucins. In addition, the adenomatous epithelium contained mostly sialomucins with a small amount of sulphomucins. The carcinomatous epithelium contained predominantly sulphomucin. The results of both the histological and immunohistochemical studies suggested the possibility of a sequential change from nonpapillary and papillary hyperplasia, via adenoma, to carcinoma in intraductal papillary-mucinous neoplasms associated with mucinous ductal ectasia. Moreover, these results, in combination with the histochemical findings, are considered helpful in making an appropriate preoperative diagnosis with endoscopic pancreatic ductal biopsy specimens, thus enabling the surgeon to select the most appropriate surgical procedure.

[Analysis of factors related to the recent decline in birth rate in Japan]

This study was undertaken in an attempt to determine whether regional differences exist for those factors which have affected the decline in the total fertility rate in Japan between 1970 and 1990. Age Stratified analysis of vital statistics of the 20 to 39-year-old female population for the 46 prefectures was performed, and evaluated in relation to urbanization. The parameters examined were birth rate, percentage of married women, rates of birth by married women, and percentage of the work force in the service industry. The results were as follows. 1. Characteristic changes were noted in birth rates for females between 25 and 29 years of age. The reasons are that average marriage age for females shifted from 20-24 to 25-29, causing the birth rates for females between the ages of 25 to 29 years to decline, while not uniformly, but with some regional differences among the 46 prefectures. 2. Urbanization has had a significant effect on the declining birth rate for females grouped by age. The advance of the urbanization process in each prefecture is directly related to the decline in the birth rates for females between 20 to 24 years and 25 to 29 years. The extent of urbanization in each prefecture is inversely related to the rate of birth by married women and the percentage of married women between age 20 to 24 and 25 to 29 in that prefecture. The trend toward delaying marriage and childbirth in the urbanized prefectures appeared to be a major factor leading to the decline in the total fertility rate.(ABSTRACT TRUNCATED AT 250 WORDS)

Astrocytic contribution to functioning synapse formation estimated by spontaneous neuronal intracellular Ca2+ oscillations

Glial contribution to in vitro synaptic function was investigated in a neuron-glia co-culture system by monitoring spontaneous oscillations of intracellular Ca2+ in neurons. Rat cortical neurons, grown stably on a cortical astrocyte monolayer, extended neurites resulting in marked functional synapse formation. Little synapse formation was observed in neuronal co-culture with meningeal fibroblasts or endothelial cells. Aged astrocytes in vitro (C35) were found to attenuate synaptic development, while young astrocytes (C5) markedly promoted synaptic function. C5 and C35 astrocyte media conditioned yielded no significant synaptogenic effect, indicating diffusible factor(s) are not responsible for our observation. Modulation of astrocytic proliferation and differentiation by gliostatin, a glial growth inhibitor, or dibutyryl cAMP affected neuronal synaptic function on the co-cultures. Site-specific analysis in homologous and heterologous neuron-astrocyte co-cultures among cortex, hippocampus, septum, and striatum revealed that homologous combinations of neurons and astrocytes derived from identical brain regions elicited the largest number of synchronizing neurons. These results suggest that in vivo neuronal synaptic function essentially requires the participation of adjacent astrocytes, which is site-specific and age-dependent.

Distribution of complement regulatory proteins, decay-accelerating factor, CD59/homologous restriction factor 20 and membrane cofactor protein in human colorectal adenoma and cancer

To clarify the events related to complement-mediated immune responses in human colorectal cancers, we immunohistochemically examined the distribution of decay-accelerating factor (DAF), CD59/homologous restriction factor 20 (HRF20), membrane cofactor protein (MCP) and terminal complement complex (TCC) in human colorectal adenomas and cancers, and then compared the findings with their distribution in normal colonic mucosa. In the normal mucosa, TCC was not present on epithelial cells. Whereas DAF and CD59/HRF20 were present only occasionally on the apical surfaces of normal epithelial cells, MCP was diffusely distributed on the basolateral surfaces of most epithelial cells of the colon. These findings suggest that MCP has a primary role in the regulation of complement activation on these cells. In adenoma cells, the expression of both DAF and CD59/HRF20 was enhanced. In cancer cells, the expression of CD59/HRF20 and MCP was diminished, whereas DAF expression was markedly enhanced. Since DAF was frequently stained in the lumen of the cancer glands, it was suggested that DAF was released into the colonic lumen in patients with colorectal cancer.

An ascidian homolog of SEC61 is expressed predominantly in epidermal cells of the embryo

In eukaryotic cells, SEC61 protein is essential for protein translocation across the endoplasmic reticulum membrane. Because of the ubiquitous nature of the protein, the expression of the corresponding gene(s) during embryogenesis has not received much attention. We found that an ascidian homolog of SEC61 is expressed predominantly in embryonic epidermal cells. A cDNA clone for Halocynthia roretzi SEC61 (HRSEC61) gene contains a single open reading frame that encodes a polypeptide of 475 amino acids. The degree of amino-acid identity was 87% between the ascidian and the dog and 55% between the ascidian and yeast. The HRSEC61 gene was transcribed maternally and zygotically. A low level of the corresponding mRNAs, about 2.3 kb in length, was found in eggs and early embryos. Zygotic mRNAs appeared after the gastrula stage, and the accumulation of the mRNAs was maximal at the neurula and tailbud stages. In situ hybridization of whole-mount specimens demonstrated that, although maternal mRNAs were distributed evenly in eggs and early embryos, the occurrence of zygotic mRNAs was predominant in differentiating epidermal cells. The predominant expression of HRSEC61 in embryonic epidermal cells was determined using cleavage-arrested embryos; those at the 16- or 32-cell stage expressed HRSEC61 in the presumptive epidermal cells of the animal hemisphere.

Expression on outer membranes of mannose residues, which are involved in osteoclast formation via cellular fusion events

Osteoclast, the bone-resorbing cell, is formed from hematopoietic precursors via cell-cell fusion. To evaluate the possibility that under certain specific conditions mannose residues may be expressed on the mammalian cell surface, we examined the action of pradimicin derivatives, which bind specific sugars such as the mannose residue, on the formation of osteoclast induced in the coculture of mouse spleen cells with mouse stromal cells, a process in which cell-cell fusion is involved. Osteoclast formation was inhibited by treatment of this coculture system with pradimicin at the later stage (day 4-7), and this inhibition was specifically abrogated by mannose-rich yeast mannan. During the 8-day cocultivation, osteoclast formation was blocked by the pradimicin on days 6 and 7, when mononuclear preosteoclasts fused into multinucleated osteoclasts. With an interactive laser cytometer ACAS570, fluorescein isothiocyanate-labeled pradimicin was observed to bind osteoclast progenitors at the fusion stage and to have no binding affinity for osteoclast progenitors at the early stage (day 0-3) or for osteoclasts, which were formed after performing fusion between mononuclear preosteoclasts. These results suggest that mannose residues were expressed on outer membranes of monocytes under pathophysiological conditions and that they were involved in the osteoclast formation via cellular membrane fusion events.

Autonomy of expression of epidermis-specific genes in the ascidian embryo

An example of developmental autonomy, assessed at the level of expression of tissue-specific genes, was characterized in this study. cDNA clones that corresponded to two different epidermis-specific genes (HrEpiA and HrEpiB) of the ascidian Halocynthia roretzi were isolated. Transcripts of both genes first appeared around the time of gastrulation, suggesting zygotic expression. In the case of HrEpiA, transcripts became undetectable after metamorphosis had begun, while transcripts of HrEpiB were still detectable in juveniles after metamorphosis. In situ hybridization analysis using HrEpiA and B probes gave the following results. (1) All types of partial embryo that originated from blastomeres with epidermal fate from two-, four-, and eight-cell embryos expressed these two epidermis-specific genes. (2) When cleavage was blocked by treatment with cytochalasin B at the one-cell stage, the cleavage-arrested one-celled embryos expressed the two genes. (3) Even when blastomeres with epidermal fate were isolated from two-, four-, and eight-cell embryos and the division of the blastomeres was arrested immediately after isolation, they expressed the two specific genes. These results suggest that the epidermal lineage in the early ascidian embryo is a developmental system with considerable self-sustainability.

Epstein-Barr virus in gastric carcinoma with lymphoid stroma. Special reference to its detection by the polymerase chain reaction and in situ hybridization in 99 tumors, including a morphologic analysis

BACKGROUND

Gastric carcinoma with lymphoid stroma (GCLS) has been reported to have a more favorable prognosis than ordinary gastric carcinoma, however, the precise mechanism of the pathogenesis for GCLS remains unclear.

METHODS

The authors analyzed 99 GCLS in 94 patients for Epstein-Barr virus (EBV) sequences using polymerase chain reaction (PCR) and in situ hybridization (ISH); these were compared with 42 ordinary gastric carcinomas.

RESULTS

Two series of PCR showed 81 (82%) and 46 (47%) of the 99 GCLS to have EBV sequences, which were significantly higher compared with ordinary gastric carcinoma (50% and 9.5%, respectively). With ISH using thymine-thymine dimerized oligonucleotide probes corresponding to EBV-encoded small RNA 1 (EBER1), 82 (83%) of 99 GCLS showed clear, intense hybridization signals localized over the nuclei of the tumor cells, in contrast to only 4 (9.5%) of 42 ordinary carcinomas (P < 0.001). A comparative morphologic analysis of EBER1-positive and negative GCLS revealed that typical features of GCLS, such as mild cellular pleomorphism, rare mitoses, a marked degree of lymphoid stroma, and mild fibrosis, together with a lymphoid infiltration within the cancer cell nests were significantly more frequent in EBER1-positive GCLS.

CONCLUSIONS

More than 80% of GCLS were associated with EBV. The presence of EBV association in GCLS was characterized by the above morphologic features.

Epstein-Barr virus in gastric carcinoma with lymphoid stroma. Special reference to its detection by the polymerase chain reaction and in situ hybridization in 99 tumors, including a morphologic analysis

BACKGROUND

Gastric carcinoma with lymphoid stroma (GCLS) has been reported to have a more favorable prognosis than ordinary gastric carcinoma, however, the precise mechanism of the pathogenesis for GCLS remains unclear.

METHODS

The authors analyzed 99 GCLS in 94 patients for Epstein-Barr virus (EBV) sequences using polymerase chain reaction (PCR) and in situ hybridization (ISH); these were compared with 42 ordinary gastric carcinomas.

RESULTS

Two series of PCR showed 81 (82%) and 46 (47%) of the 99 GCLS to have EBV sequences, which were significantly higher compared with ordinary gastric carcinoma (50% and 9.5%, respectively). With ISH using thymine-thymine dimerized oligonucleotide probes corresponding to EBV-encoded small RNA 1 (EBER1), 82 (83%) of 99 GCLS showed clear, intense hybridization signals localized over the nuclei of the tumor cells, in contrast to only 4 (9.5%) of 42 ordinary carcinomas (P < 0.001). A comparative morphologic analysis of EBER1-positive and negative GCLS revealed that typical features of GCLS, such as mild cellular pleomorphism, rare mitoses, a marked degree of lymphoid stroma, and mild fibrosis, together with a lymphoid infiltration within the cancer cell nests were significantly more frequent in EBER1-positive GCLS.

CONCLUSIONS

More than 80% of GCLS were associated with EBV. The presence of EBV association in GCLS was characterized by the above morphologic features.

Significance of amino groups of phosphatidylethanolamine in phospholipid peroxidation of mixed liposomes

The effect of distribution of phosphatidylethanolamine (PE) in multilamellar vesicles (MLV) on their peroxidative susceptibility was studied. Liposomes containing various ratios of L-alpha-dilinoleoyl phosphatidylcholine (DiLinPC) and L-alpha-dilinoleoyl phosphatidylethanolamine (DiLinPE) were peroxidized by ferrous ion or a water-soluble radical initiator 2,2'-azobis (2-amidino-propane) dihydrochloride (AAPH). The oxygen consumption rate was compared with the formation kinetics of fluorescent products. Inclusion of PE in liposomes was found to accelerate the Fe(2+)-dependent peroxidation. Modification of the amino group of PE with 2,4,6-trinitrobenzenesulfonic acid (TNBS) inhibited Fe(2+)-induced oxygen consumption in the late stage where fluorescent substances formed. A possible role of the amino group of PE on lipid peroxidation is discussed, especially in terms of its reactivity with oxidation products and subsequent formation of fluorescent substances.

Human neuroblastoma growth inhibitory factor (h-NGIF), derived from human astrocytoma conditioned medium, has neurotrophic properties

Investigations on the general characteristics of human astrocytoma cell line NAC-1 revealed neuroblastoma growth inhibitory activity in conditioned medium. Neuroblastoma growth inhibitory factor (NGIF) was partially purified by Econo Q, Econo CM, and Superose 12 column chromatography. The protein is weakly basic with an estimated M(r) of 120,000, possibly having an M(r) 60,000 dimeric structure. NGIF inhibits the growth of human neuroblastoma cell lines but has no effect on morphology nor does it produce any change in the growth of human glioblastoma cell lines. Interestingly, NGIF appears to promote survival and neurite outgrowth of embryonal rat cortical neurons. These neurotrophic properties suggest a role for NGIF in the development of the nervous system.

Epstein-Barr virus in gastric carcinoma with lymphoid stroma. Special reference to its detection by the polymerase chain reaction and in situ hybridization in 99 tumors, including a morphologic analysis

BACKGROUND

Gastric carcinoma with lymphoid stroma (GCLS) has been reported to have a more favorable prognosis than ordinary gastric carcinoma, however, the precise mechanism of the pathogenesis for GCLS remains unclear.

METHODS

The authors analyzed 99 GCLS in 94 patients for Epstein-Barr virus (EBV) sequences using polymerase chain reaction (PCR) and in situ hybridization (ISH); these were compared with 42 ordinary gastric carcinomas.

RESULTS

Two series of PCR showed 81 (82%) and 46 (47%) of the 99 GCLS to have EBV sequences, which were significantly higher compared with ordinary gastric carcinoma (50% and 9.5%, respectively). With ISH using thymine-thymine dimerized oligonucleotide probes corresponding to EBV-encoded small RNA 1 (EBER1), 82 (83%) of 99 GCLS showed clear, intense hybridization signals localized over the nuclei of the tumor cells, in contrast to only 4 (9.5%) of 42 ordinary carcinomas (P < 0.001). A comparative morphologic analysis of EBER1-positive and negative GCLS revealed that typical features of GCLS, such as mild cellular pleomorphism, rare mitoses, a marked degree of lymphoid stroma, and mild fibrosis, together with a lymphoid infiltration within the cancer cell nests were significantly more frequent in EBER1-positive GCLS.

CONCLUSIONS

More than 80% of GCLS were associated with EBV. The presence of EBV association in GCLS was characterized by the above morphologic features.