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N Teramoto

Publications and source records attributed to N Teramoto.

At least 55 records · Page 3Linked to original sources
PubMed1998

Polymerase chain reaction and in situ hybridization of Epstein-Barr virus in liver biopsy specimens facilitate the diagnosis of EBV hepatitis after liver transplantation.

A nested polymerase chain reaction (nPCR) for Epstein-Barr virus (EBV) DNA, RNA in situ hybridization (EBER-ISH), and immunostaining against the ZEBRA EBV protein for diagnosis of EBV hepatitis were performed on 43 liver biopsy specimens obtained from 18 patients in the 1st year after liver transplantation (LTX). The findings were related to liver histology and results of EBV-nPCR on concomitantly obtained serum samples. EBV DNA was detected in 30% and RNA in 34% of the liver biopsy specimens using nPCR and EBER-ISH, respectively, giving a significant correlation between the two methods (P = 0.003). All but one patient had detectable EBV DNA in serum samples obtained within 1 month of the biopsy. More than 90% of the nPCR and EBER-ISH-positive biopsy specimens were obtained 3 months or less post-LTX. There was no significant difference in EBV genome findings in biopsy specimens with or without lymphocytic-immunoblastic infiltrates, either in nPCR (P = 0.73) or in ISH (P = 0.73). Two of three biopsy specimens with these histological changes suggesting a viral genesis were positive in EBV-nPCR but negative in ISH. Histopathological changes in EBV hepatitis may be nonspecific and masked by other complications. The use of EBV-nPCR and EBER-ISH in liver graft biopsy specimens of heavily immunosuppressed patients may give an early indication of EBV-related disease and can be used to guide therapeutic intervention.

Adolescent↗
PubMed1998

Simultaneous detection of two independent antigens by double staining with two mouse monoclonal antibodies.

Simultaneous detection of two antigens by immunostaining usually requires primary antibodies from two different species or a hapten modification of one of the antibodies if they are from the same species. A novel double staining method is described for immunodetection of two independent antigens using two mouse monoclonal antibodies. The principle of the method is the following: The first antigen is detected by a monoclonal antibody that is diluted so extensively that it cannot be recognized with conventional detection systems. A highly sensitive biotin-tyramide amplification system is used to identify this antibody. The second antigen is stained with a monoclonal antibody by dilution and detected by conventional immunostaining. The method was tested for both alkaline-phosphatase staining on paraffin sections and immunofluorescence staining on cultured cells in cytospin preparation. The absence of cross-reaction in the former system was demonstrated by the mutually exclusive detection of T- and B-cells in human lymph nodes or T-cells and carcinoma cells in nasopharyngeal carcinoma biopsies. Similarly, the EBV encoded EBNA2 and ZEBRA proteins showed a mutually exclusive staining by immunofluorescence on B95-8 cells. The method could be used to demonstrate co-expression of two independent antigens in the same cells, such as PCNA and keratin in carcinoma cells in paraffin sections and for EBNA2 and LMP1 EBV proteins in immunofluorescence preparations of B95-8 cells.

Alkaline Phosphatase↗
PubMed1998

The effects of nifedipine and other calcium antagonists on the glibenclamide-sensitive K+ currents in smooth muscle cells from pig urethra.

1. The effects of nifedipine on both levcromakalim-induced membrane currents and unitary currents in pig proximal urethra were investigated by use of patch-clamp techniques (conventional whole-cell configuration and cell-attached patches). 2. Nifedipine had a voltage-dependent inhibitory effect on voltage-dependent Ba2+ currents at - 50 mV (Ki=30.6 nM). 3. In current-clamp mode, subsequent application of higher concentrations of nifedipine (> or =30 microM) caused a significant depolarization even after the membrane potential had been hyperpolarized to approximately -82 mV by application of 100 microM levcromakalim. 4. The 100 microM levcromakalim-induced inward current (symmetrical 140 mM K+ conditions, -50 mV) was inhibited by additional application of three different types of Ca antagonists (nifedipine, verapamil and diltiazem, all at 100 microM). In contrast, Bay K 8644 (1 microM) possessed no activating effect on the amplitude of this glibenclamide-sensitive current. 5. When 100 microM nifedipine was included in the pipette solution during conventional whole-cell recording at -50 mV, application of levcromakalim (100 microM) caused a significant inward membrane current which was suppressed by 5 microM glibenclamide. On the other hand, inclusion of 5 microM glibenclamide in the pipette solution prevented levcromakalim from inducing an inward membrane current. 6. The levcromakalim-induced K+ channel openings in cell-attached configuration were suppressed by subsequent application of 5 microM glibenclamide but not of 100 microM nifedipine. 7. These results suggest that in pig proximal urethra, nifedipine inhibits the glibenclamide-sensitive 43 pS K+ channel activity mainly through extracellular blocking actions on the K+ channel itself.

Animals↗
PubMed1998

Restricted expression of Epstein-Barr virus (EBV)-encoded, growth transformation-associated antigens in an EBV- and human herpesvirus type 8-carrying body cavity lymphoma line.

A body cavity lymphoma-derived cell line (BC1), known to carry both Epstein-Barr virus (EBV) and human herpes virus type 8 (HHV-8; or Kaposi's sarcoma-associated herpesvirus, KSHV), was analysed for the expression of EBV-encoded, growth transformation-associated antigens and cellular phenotype by immunofluorescence staining, Western blotting, RT-PCR and flow cytometry. A similar phenotypic analysis was also performed on another body cavity lymphoma line, BCBL1, that is singly infected with HHV-8. Phenotypically, the two lines were closely similar. Although both lines are known to carry rearranged immunoglobulin genes, they were mostly negative for B-cell surface markers. Both expressed the HHV-8-encoded nuclear antigen (LNA1). Similarly to Epstein-Barr nuclear antigen type 1 (EBNA1), LNA1 was associated with the chromatin in interphase nuclei and the mitotic chromosomes in metaphase. It accumulated in a few well-circumscribed nuclear bodies that did not co-localize with EBNA1. BC1 cells expressed EBNA1, LMP2A and EBV-encoded small RNAs but not EBNA2-6, LMP1 and LMP2B. They were thus similar to type I Burkitt's lymphoma cells and latently infected peripheral B-cells. Analysis of the splicing pattern of the EBNA1-encoding message by RT-PCR showed that BC1 cells used the QUK but not the YUK splice, indicating that the mRNA was initiated from Qp and not from Cp or Wp.

Antigens, Viral↗
PubMed1998

p53 protein expression in non-Hodgkin's lymphomas is infrequently related to p53 gene mutations.

Accumulation of the p53 protein has been found in several types of lymphomas. However, p53 gene mutations have been infrequently demonstrated in some specific types of lymphomas. In the present study, a correlation between p53 immunoreactivity and p53 gene mutations in a large panel of non-Hodgkin's lymphoma (NHL) cases is attempted. A panel of 202 cases of NHL was evaluated by immunohistochemical staining for p53 protein. All cases that were immunohistochemically positive for p53 protein were analyzed by the polymerase chain reaction (PCR) single strand conformation polymorphism (SSCP) method to identify mutations within the p53 gene. In order to confirm the mutation, sequencing of PCR-amplified p53 gene segments was performed. Overexpression of p53 protein was found in 59 of the 202 cases of NHL, but only four of these 59 cases showed a shift on SSCP analysis, and point mutations were detected in three of them by the subsequent sequencing. p53 immunoreactivity was generally greater in high-grade lymphoma. The results of this study suggest that immunohistochemical reactivity for p53 protein is not a reliable indicator of the presence of their structural alterations of p53 gene exons 4-9 in NHL.

Amino Acid Sequence↗
PubMed1997

Activity of glibenclamide-sensitive K+ channels under unstimulated conditions in smooth muscle cells of pig proximal urethra.

The membrane potential in pig proximal urethra was examined by use of the microelectrode technique. In cells 1-2 cm from the bladder neck the membrane potential was quiescent, with a value of -37.2+/-2.5 mV (n = 16). In some cells small spontaneous de- and hyperpolarizations were seen. Glibenclamide (1 microM) caused a small but significant depolarization in tissue strips (12+/-3 mV, n = 3) and also in dispersed cells using whole-cell patch electrodes (13+/-3 mV, n = 5). In the conventional whole-cell voltage-clamp configuration, glibenclamide reduced the noise level of the basal membrane current at -50 mV and inhibited the membrane current in symmetrical 140 mM K+ conditions. In cell-attached patches, brief openings of a glibenclamide-sensitive 43 pS K+ channel (K(GS)-43 pS) were seen even under unstimulated conditions and greater activation occurred in the same membrane patch on subsequent application of 100 microM levcromakalim. These results provide direct evidence that glibenclamide-sensitive K+ channels may play a role in maintaining the resting membrane potential of pig proximal urethra under unstimulated conditions.

Animals↗
PubMed1997

Effects of levcromakalim and nucleoside diphosphates on glibenclamide-sensitive K+ channels in pig urethral myocytes.

1. Effects of levcromakalim and nucleoside diphosphates (NDPs) on both membrane currents and unitary currents in pig proximal urethra were investigated by use of patch clamp techniques (conventional whole-cell configuration, nystatin perforated patch, cell-attached configuration and inside-out patches). 2. Levcromakalim produced a concentration-dependent outward current at a holding potential of -50 mV. The peak current amplitude showed little variation when measured by either conventional whole-cell or nystatin perforated patch configurations. 3. In conventional whole-cell configuration, the levcromakalim (100 microM)-induced outward current decayed by about 90% in 18 min. In contrast, with the nystatin perforated patch, approximately 86% of the levcromakalim-induced outward current still remained after 18 min. 4. The peak amplitude of the levcromakalim (100 microM)-induced outward membrane current recorded by the conventional whole-cell configuration was greatly reduced by inclusion of 5 mM EDTA in the pipette. The much smaller but significant outward membrane current remaining was abolished by glibenclamide. 5. In conventional whole-cell recordings, inclusion of an NDP in the pipette solution induced a small outward current which slowly reached a maximal amplitude (in 2 to 10 min) and was suppressed by glibenclamide. Addition of 100 microM levcromakalim after the NDP-induced current had peaked activated a further outward current which was larger than that recorded in the absence of NDPs. Approximately 50% of this current still remained at 18 min, even when conventional whole-cell configuration was used. 6. In the cell-attached mode in symmetrical 140 mM K+ conditions, glibenclamide inhibited the 100 microM levcromakalim-activated 43 pS K+ channel in a concentration-dependent manner, showing an inhibitory dissociation constant (Ki) of approximately 520 nM. 7. In inside-out patches in which the glibenclamide-sensitive K+ channel had run down after exposure to levcromakalim, both uridine 5'-diphosphate (UDP) and MgATP were capable of reactivating the channel. Further application of Mg2+ to the UDP-reactivated K+ channels enhanced the channel activity reversibly. 8. In inside-out patches UDP was capable of activating the glibenclamide-sensitive K+ channel without levcromakalim, providing that there was free Mg2+ present (either UDP in 5 mM EGTA or UDP in 5 mM EDTA with Mg2+). Additional application of levcromakalim caused a further reversible activation of channel opening. 9. In the presence of levcromakalim, application of adenosine 5'-triphosphate (ATP) to the inner surface of the membrane patch inhibited UDP-reactivated channel opening in a concentration-dependent manner. 10. Addition of an untreated cytosolic extract of pig proximal urethra reactivated the glibenclamide-sensitive K+ channel in the presence of 100 microM levcromakalim in inside-out patches. 11. These results demonstrate the presence in the pig proximal urethra of a glibenclamide-sensitive K+ channel that is blocked by intracellular ATP and can be activated by levcromakalim. Intracellular UDP can reactivate the channel after rundown. Additionally, intracellular Mg2+ may play an important role in regulating the channel activity.

Adenosine Triphosphate↗
PubMed1997

Analysis of the genome of an Epstein-Barr-virus (EBV)-related herpesvirus in a cynomolgus monkey cell line (Si-IIA).

A simian cell line, Si-IIA, harboring Epstein-Barr-virus (EBV)-related herpesvirus (Si-IIA-EBV), produces malignant lymphoma in rabbits when administered by intravenous inoculation. In this study, we analyzed the Si-IIA-EBV genome and compared it with human EBV and herpesvirus macaca fascicularis 1 (HVMF 1), which is associated with B-cell lymphoma developing in SIV-infected immunosuppressed monkeys. DNA from Si-IIA-EBV was amplified by the polymerase chain reaction using three different primer pairs complementary to human EBV (B95-8) DNA; two of the primer pairs covered part of the long internal repeat 1 region (IR 1) and the third covered part of the BRRF 1 region. Direct sequencing of the three PCR products revealed that Si-IIA-EBV DNA had about 82% nucleotide homology to the human EBV DNA in all three regions and 92.4% homology to HVMF1 in the IR1 region. The blotting pattern by Southern blot analysis was different between Si-IIA-EBV and human EBV.

Animals↗
PubMed1997

Nicorandil activates glibenclamide-sensitive K+ channels in smooth muscle cells of pig proximal urethra.

The effects of nicorandil on ionic currents recorded from single smooth muscle cells of pig proximal urethra were investigated using patch-clamp techniques. Tension measurement was also performed to study the effects of nicorandil on the resting tone of pig urethra. Nicorandil produced a concentration-dependent sustained outward current that was suppressed by glibenclamide at -50 mV and was carried selectively by K+. In cell-attached configuration, nicorandil activated a 43-pS K+ channel that was reversibly inhibited by 10 microM glibenclamide. This glibenclamide-sensitive 43-pS K+ channel (KGS) "ran down" after excision of the membrane patch. In inside-out configuration, the application of either 1 mM Mg-ATP or 1 mM nucleotide diphosphate reactivated the KGS. In symmetrical 140 mM K+ conditions, 300 microM nicorandil and 300 microM levcromakalim activated a 2.14-pA K+ channel that exhibited the same amplitude and similar channel-opening kinetics. Methylene blue (10-100 microM), a soluble guanylate cyclase inhibitor, did not inhibit the opening of the nicorandil-induced KGS. The KGS was not activated by either sodium nitroprusside (10-100 microM) or 8-bromo guanosine 3':5'-cyclic monophosphate (1 mM). Nicorandil caused a concentration-dependent relaxation of the urethral resting tone but was less potent than levcromakalim. The relaxation induced by 10 microM nicorandil was partially inhibited by glibenclamide (1-10 microM) and also by methylene blue (10-100 microM). These results indicate that two independent nicorandil-induced relaxation mechanisms may be present in pig urethra.

Adenosine Triphosphate↗
PubMed1996

Epstein-Barr virus infection in the neoplastic and nonneoplastic cells of lymphoid malignancies.

BACKGROUND: The Epstein-Barr virus (EBV) has been frequently detected in lymphoid malignancies. However, EBV infection in the nonneoplastic cells of lymphoid malignancies has not been extensively studied. METHODS: Four hundred nine cases of lymphoid malignancies including 377 non-Hodgkin's lymphoma (NHL) and 32 Hodgkin's disease (HD) were examined for EBV infection by EBER-1 in situ hybridization (EBER-ISH), immunostaining against LMP-1, Epstein-Barr nuclear antigen 2 (EBNA2) and ZEBRA, and Southern hybridization using a BamHIW fragment as a probe. Double staining with EBER-ISH and immunostaining against CD20, CD45RO, and LMP-1 was performed in selected cases. RESULTS: Although EBER-1-positive cells (EPCs) were detected in 49 of 276 B-cell lymphomas, 31 of 100 T-cell lymphomas, 1 of 1 natural killer-cell lymphoma, and 17 of 32 HDs, almost all of the tumor cells were exclusively EBER-1-positive in the 10 NHL cases. Some EPCs were of different cell lineages than the tumor cells in 15 of the 26 NHLs examined by double staining. LMP-1, EBNA2, and ZEBRA were detected in 22, 4, and 3 cases, respectively. In 4 LMP-1-positive HDs, double staining revealed that some EBER-1-positive Reed-Sternberg cells were negative for LMP-1, EBV genomic DNA was detected in 8 of the 39 examined cases. CONCLUSIONS: T-cell lymphomas contained EPCs more frequently than B-cell lymphomas. Nonneoplastic lymphocytes were infected with EBV more frequently than lymphoma cells. Rowe's latency II may be unstable in lymphoid malignancies. Some NHLs, especially T-cell lymphoma, may provide favorable conditions for EBV infection of nonneoplastic lymphocytes.

Antigens, Viral↗
PubMed1996

Clonal analysis by polymerase chain reaction of B-cell lymphoma with late relapse: a report of five cases.

BACKGROUND: Little is known about the clonal heterogeneity of non-Hodgkin's lymphoma between presentation and relapse, although several such reports have been published on acute lymphoblastic leukemia. METHODS: We examined five patients with B-cell lymphoma who relapsed more than 5 years after initial presentation. Formalin fixed, paraffin embedded tissues were analyzed for clonal immunoglobulin heavy chain gene rearrangement by the polymerase chain reaction (PCR) and sequencing of the PCR products. Four specimens retained the original histologic type, but one showed histologic transformation from diffuse large cell lymphoma to follicular small cleaved cell lymphoma. RESULTS: Although the size of the PCR products looked identical on the gel between presentation and relapse in all patients, only three of the four specimens that retained the original type had identical gene rearrangements at both presentation and relapse. One of these four and the fifth specimen showed novel gene rearrangements. CONCLUSIONS: This study suggests that late relapse lymphoma may present as a new clone. Sequencing of the PCR products is important in the evaluation of clonal heterogeneity.

Adult↗
PubMed1996

Effects of calciseptine on unitary barium channel currents in guinea-pig portal vein.

Effects of synthesized calciseptine (CaS), found naturally in the venom of the black mamba, on voltage-dependent Ca2+ channels in smooth muscle cells of the guinea-pig portal vein were investigated. In the whole-cell voltage-clamp configuration, extracellular application of CaS (>/= 10 nM) inhibited the inward current in a concentration- and voltage-dependent manner at a holding potential of -90 mV. The Ca2+ current recorded at a high holding potential (-50 mV) was approximately 8 times more sensitive to CaS than that at a more negative holding potential (-90 mV). CaS (50 nM) shifted to the left the steady-state inactivation curve obtained by using single 8-s conditioning pulses of various amplitudes. When CaS (>/= 200 nM) was present in the pipette, the Ca2+ current remained for the duration of the experiments (more than 60 min) in the whole-cell configuration. Two different Ca2+ channel conductances are present in this tissue (25-pS and 12-pS channels). Both channels are blocked by dihydropyridine (DHP) derivatives, but have different sensitivities. In the cell-attached condition, CaS hardly changed the activity of either unitary Ca2+ channel current. To prevent the "run down" of the Ca2+ channels in cell-free conditions, we added cardiac cytosol, a supernatant from homogenized cardiac cells and an endogenous Ca2+ channel activating factor, in the pipette. The unitary Ca2+ channel currents were then recorded using the outside-out membrane patch configuration. Application of CaS (1 microM) in the bath completely blocked the open events of the 25-pS Ca2+ channel. CaS (10 nM) in the bath reduced the mean open time and channel availability, resulting in a decrease in the open probability of the 25-pS channel currents without affecting the amplitude of the single-channel conductance. CaS also reduced the open probability (though less potently) and channel availability of the 12-pS Ca2+ channel without a change in its amplitude. From these results, we conclude that CaS has inhibitory effects on the voltage-dependent Ca2+ current that are similar to those of DHP derivatives and that it acts from the outside of the membrane.

Animals↗
PubMed1996

Metastatic potential of lymphoma/leukemia cell lines in SCID mice is closely related to expression of CD44.

To investigate whether the lymphocyte homing receptors, adhesion molecules regulating normal lymphocyte traffic, influence the dissemination of lymphoma cells, 24 lymphoma/leukemia cell lines were inoculated into SCID mice subcutaneously, and the correlation between the expression of the adhesion molecules and the metastatic potential of the cell lines was examined. Among the six adhesion molecules examined (LFA-1, ICAM-1, CLA, VLA-4, L-selectin and CD44), L-selectin increased the incidence of lymph node metastasis, and CD44 expression was related to both lymph node and organ (hematogenous) metastasis. A monoclonal antibody to the standard form of CD44 (CD44s), Hermes-3, inhibited the local growth and remote metastasis of CD44+ cell lines. Thus, it is concluded that at least CD44s expression is important in both lymphatic and hematogenous metastasis.

Animals↗
PubMed1996

Activation by levcromakalim and metabolic inhibition of glibenclamide-sensitive K channels in smooth muscle cells of pig proximal urethra.

1. The effects of levcromakalim (BRL 38227) on ionic currents recorded from pig proximal urethra were investigated by use of tension measurement and patch clamp techniques (conventional whole-cell configuration, nystatin perforated patch, and cell-attached configuration). 2. Levcromakalim (1 microM) caused a relaxation in the resting tone. This levcromakalim-induced relaxation was inhibited by the pretreatment with 1 microM glibenclamide. 3. The resting membrane potential recorded from single cells in current-clamp mode was-36.1 +/- 4.4 mV (n = 5). 4. Levcromakalim induced a concentration-dependent hyperpolarization with a maximum (at > or = 10 microM) close to the theoretical equilibrium potential of potassium (EK). The membrane hyperpolarization caused by 1 microM levcromakalim (24.7 +/- 5.8 mV, n = 4) was abolished by 1 microM glibenclamide. 5. Levcromakalim (100 microM) caused an outward K current in whole-cell recordings which was unaffected by iberiotoxin (300 nM) but abolished by glibenclamide (10 microM). 6. In cell-attached patches, levcromakalim activated a 43 pS K channel which was inhibited by the application of glibenclamide. 7. The metabolic poison, cyanide (CN), also activated a 43 pS K channel which was suppressed by the application of 10 microM glibenclamide. 8. These results indicate that levcromakalim and metabolic inhibition activate the same 43 pS K channel in pig proximal urethra. The resultant urethral hyperpolarization might reduce the usefulness of K channel openers in the treatment of detrusor instability, but be of value in treating outflow obstruction.

Animals↗
PubMed1996

Detection of Epstein-Barr virus RNA and related antigens in non-neoplastic lymphoid lesions.

To elucidate the latent state and reactivation of Epstein-Barr virus (EBV) in non-neoplastic lymphoid lesions, we investigated 144 non-neoplastic lymphoid lesions by in situ hybridization (ISH) to detect the expression of EBV-encoded small RNAs (EBER)-1 and BCRF-1 and by immunostaining for latent membrane protein (LMP)-1 and ZEBRA. ISH for EBER-1 detected EBER-1-positive cells (EPC) in 31 of the 144 examined lesions (22%). EPC were detected in 4 of 49 cases of nonspecific lymphoid hyperplasia, in 16 of 20 abscess-forming granulomatous lymphadenitis (AFGL), 5 of 25 Kikuchi's disease, and in 3 of 3 infectious mononucleosis. LMP-1 was expressed in 6 of 124 non-neoplastic lymphoid lesions (4.8%). LMP-1-positive cells were observed in 6 of the 31 EBER-1-positive cases (19%). EPC were detected significantly more frequently in LMP-1- and ZEBRA-positive specimens than in the LMP-1- and ZEBRA-negative specimens. BCRF-1 was expressed in 4 of 11 cases examined: 2 of 3 AFGL, 1 of 2 Kikuchi's disease, and in the 1 case of atypical lymphoid hyperplasia. This study suggests that Epstein-Barr virus is prevalent and can be reactivated in the lymph nodes effaced by destructive inflammation, such as AFGL. Such inflammation may provide a local milieu that is conducive for EBV to enter the lytic cycle.

Base Sequence↗
PubMed1996

Variable expression of Epstein-Barr virus latent membrane protein I in Reed-Sternberg cells of Hodgkin's disease.

Reed-Sternberg cells (RS cells) of Hodgkin's disease (HD) are frequently infected with Epstein-Barr virus (EBV) and express EBV-encoded nonpolyadenylated RNA transcripts (EBER)-1. EBV latency has been classified into three distinct forms: Latency I, expressing only one of the latent proteins, EBV nuclear antigen (EBNA)-1, latency II, coexpressing EBNA-1 and LMPs, and latency III, expressing all latent viral proteins. RS cells express LMP-1 in addition to EBNA-1 and are considered to be EBV latency II frequently encountered in nasopharyngeal carcinoma. We examined 13 cases of EBV-infected HD by combined EBER-1 in situ hybridization and immunostaining for LMP-1. All of the RS cells expressed EBER-1, but a substantial number of EBER-1+ RS, cells were negative for LMP-1. The percentage of LMP-1+ RS cells out of EBER-1+ RS cells varied from 7% to 100% (average 69%). In this study, we showed that all EBV-infected RS cells were not restricted to latency II, and some belonged to latency I.

Herpesvirus 4, Human↗
PubMed1996

[In situ detection of Epstein-Barr virus in the non-neoplastic gastric glands and infiltrated lymphocytes].

Recently, clonal EBV-DNA and/or EBV-encoded small RNA(EBER1) have been detected in some gastric carcinomas. We reported the first observation of EBV infection in gastric glands with intestinal metaplasia, and characterized the EBV-infected lymphocytes which infiltrated in gastric mucosa. To determine the cellular location of EBV, EBER1 in situ hybridization(ISH) with an EBER1 oligonucleotide probe was applied to paraffin sections of the non-neoplastic gastric mucosa in 80 cases of gastric carcinoma and 49 cases of gastric ulcer. Not only was EBER1 expression detected in the nucleus of gastric cancer cells(5 cases) but also in non-neoplastic gastric epithelial cells(3 cases) and in infiltrated lymphocytes(40 cases). A single or a few shedding non-neoplastic epithelial cells in 2 cases of EBV-associated gastric cancer showed EBER1 expression. In one case, EBER1 was observed in all of the epithelial cells of a few gastric glands with intestinal metaplasia, suggesting that the stem cells of the metaplastic gastric glands were infected with EBV. EBV DNA was also detected in the EBER1-positive metaplastic glands scratched from the paraffin section by a single cell PCR method with a BamHI W primer pair. However, immunohistochemical examination showed that these metaplastic glands lacked expression of EBNA2 and LMP-1. The observation of these rare EBV-infected metaplastic glands reinforces the pre-transformation EBV infection hypothesis for EBV-associated gastric carcinoma. The double staining using ISH and immunohistochemistry revealed that EBER1 positive lymphocytes showed a B cell marker of L26(< 50%) but not T cell markers of UCHL1 and OPD4.

B-Lymphocytes↗