Cyclic-AMP inhibits nitric oxide-induced apoptosis in human osteoblast: the regulation of caspase-3, -6, -9 and the release of cytochrome c in nitric oxide-induced apoptosis by cAMP

Nitric oxide (NO) induces apoptotic cell death and cAMP has a significantly protective effect on NO-induced cytotoxicity in human osteoblasts, MG-63 cells. Treatment with S-nitroso-N-acetylpenicillamine (SNAP) (0.6 mM) resulted in genomic DNA fragmentation, characteristic of apoptosis. However, concomitant incubation of the cells with either DBcAMP or forskolin markedly inhibited SNAP-induced apoptosis in a dose-dependent manner. Furthermore, pretreatment of MG-63 cells with H-89 or KT5720, which is known to inhibit cAMP-dependent protein kinase (PKA), abolished the protective effect of DBcAMP and forskolin on SNAP-induced apoptosis. In this study, we explored the involvement of caspases in the regulatory mechanism of SNAP-induced apoptosis by cAMP. Our data show that DBcAMP or forskolin blocked SNAP-induced caspase-3-like cysteine protease activation and that H-89, a PKA inhibitor, reversed the cAMP-induced regulatory effect of caspase-3 like protease. Consistent with the results, cAMP inhibited the proteolytic cleavage of caspase-3, -6, -9 and cytochrome c release to cytoplasm. The inhibition of caspase-3 activation did not block SNAP-induced cytochrome c release to cytoplasm, suggesting that caspase-3 activation may occur downstream of cytochrome c release. In summary, these findings show that the exposure of MG-63 cells to cAMP analogs renders them more resistant to NO-induced damage and suggests the presence of regulatory mechanisms of the cell death pathway by cAMP in which caspase-3, -6, and -9 and cytochrome c release serves to mediate NO-induced apoptosis.

Epstein-Barr virus-associated peripheral T-cell lymphoma in adults with hydroa vacciniforme-like lesions

We describe two Korean adult patients who had necrotizing papulovesicles mainly on their faces. Skin biopsy specimens showed perivascular and periadnexal infiltrate of atypical lymphoid cells with vasculitis in the dermis and subcutaneous tissue. In situ hybridization demonstrated a latent infection of Epstein-Barr virus in the majority of lymphoid cells in the dermis. These patients were diagnosed as having T-cell lymphoma. Interestingly, large granular lymphocytosis was found in the peripheral blood of Case 2.

Histone deacetylases induce angiogenesis by negative regulation of tumor suppressor genes

Low oxygen tension influences tumor progression by enhancing angiogenesis; and histone deacetylases (HDAC) are implicated in alteration of chromatin assembly and tumorigenesis. Here we show induction of HDAC under hypoxia and elucidate a role for HDAC in the regulation of hypoxia-induced angiogenesis. Overexpressed wild-type HDAC1 downregulated expression of p53 and von Hippel-Lindau tumor suppressor genes and stimulated angiogenesis of human endothelial cells. A specific HDAC inhibitor, trichostatin A (TSA), upregulated p53 and von Hippel-Lindau expression and downregulated hypoxia-inducible factor-1alpha and vascular endothelial growth factor. TSA also blocked angiogenesis in vitro and in vivo. TSA specifically inhibited hypoxia-induced angiogenesis in the Lewis lung carcinoma model. These results indicate that hypoxia enhances HDAC function and that HDAC is closely involved in angiogenesis through suppression of hypoxia-responsive tumor suppressor genes.

Purification of soluble beta-glucan with immune-enhancing activity from the cell wall of yeast

Beta-glucan, one of the major cell wall components of Saccharomyces cerevisiae, has been found to enhance immune functions, especially by activating macrophages. However, a major obstacle to the clinical application of beta-(1-->3)-glucan is its low solubility in aqueous media. In this study, soluble beta-glucan, free of mannoprotein, was prepared, and its effects on TNF-alpha secretion and phagocytosis by macrophages were evaluated. Beta-glucan was first rendered soluble from the yeast cell wall by alkaline extraction (glucan-p1). The extract contained 2.8% of protein which was subsequently removed by successive DEAE-cellulose and ConA chromatography. Beta-glucan thus prepared was completely free of mannoprotein and was soluble at neutral pH (glucan-p3). The effects of beta-glucan on phagocytosis and TNF-alpha release activity were investigated. While glucan-p1 moderately induced TNF-alpha secretion at 200 microg/ml (550 pg of TNF-alpha/5 x 10(5) cells), glucan-p3 markedly stimulated macrophages at 200 microg/ml (2,860 pg of TNF-alpha/5 x 10(5) cells). Furthermore, glucan-p3 stimulated phagocytosis about 20% more than glucan-p1 did. In conclusion, we purified water-soluble beta-glucan which was completely devoid of mannoprotein and effectively stimulated the macrophage function, enabling it to be used as an intravenous injection for sepsis.

Laparoscopic versus open bowel resection for Crohn's disease

BACKGROUND

Laparoscopic bowel resection is an alternative to open surgery for patients with Crohn's disease requiring surgical resection. The present report describes a seven-year experience with the laparoscopic treatment of Crohn's disease compared with the open technique in a tertiary Canadian centre.

PATIENTS AND METHODS

A retrospective analysis of 61 consecutive patients undergoing elective resection for Crohn's disease was carried out between October 1992 and June 1999. This analysis included 32 laparoscopic resections (mean age 33 years) and 29 open resections (mean age 42 years). Patient demographics were compared, as well as short and long term outcomes after surgery (mean follow-up 39 months).

RESULTS

Patients in the laparoscopic group were younger and had fewer previous bowel surgeries than patients who had open resections. Indications for surgery and operative times were similar between the groups. Patients who underwent laparoscopic resections required fewer doses of narcotic analgesics. The resumption of bowel function after surgery, and tolerance of a clear liquid and solid diet was quicker in the laparoscopic group. Patients who underwent laparoscopic resections had significantly shorter hospital stays than those who underwent open resections. Fifteen patients (48.4%) in the laparoscopic group experienced recurrence of disease compared with 13 patients (44.8%) in the open group. In both groups, the most common site of recurrence was at the anastomosis. The disease-free interval was the same length for both groups (23.9+/-17.3 months for the laparoscopic resection patients compared with 23.9+/-20.2 months for the open resection patients; P=1.00).

CONCLUSIONS

Laparoscopic resection for Crohn's disease can be performed safely and effectively. Quicker resumption of oral feeds, less postoperative pain and earlier discharge from hospital are advantages of the laparoscopic method. No differences in the recurrence rate or the disease-free interval were noted.

Antiosteoporotic activity of Dae-Bo-Won-Chun in ovariectomized rats

The preventive effect of the herbal formulation, "Dae-Bo-Won-Chun" (DBWC), on the progress of bone loss induced by ovariectomy (OVX) was studied in rats. From light microscope analyses, porous or erosive appearances were observed on the surface of trabecular bone of tibia in ovariectomized rats, whereas those of the same bone in sham-operated rats were composed of fine particles. The trabecular bone area and trabecular thickness in ovariectomized rats decreased by 50% from those in sham-operated rats, these decreases were completely inhibited by administration of DBWC at a concentration of 10 mg/kg per day for 7 weeks. The mechanical strength of the neck of the femur was decreased by ovariectomy, and this was significantly suppressed by the administration of DBWC. Serum phosphorus, alkaline phosphatase and thyroxine levels in ovariectomized rats increased compared with those in sham-operated rats, and increases were completely inhibited by the administration of DBWC. These results strongly suggest that DBWC is effective in preventing the development of bone loss induced by ovariectomy in rats.

Could ionizing radiation forestall cauliflower ear?

Repeated trauma to the ear very often results in "cauliflower ear." Many methods have been suggested to prevent an injured ear from demonstrating a cauliflowerlike deformity. The principles of treatment are evacuation of the hematoma, control of the reaccumulation of fluid, and maintenance of the cartilage contour. The authors studied the effect of ionizing radiation on deformed rabbit ears induced by repeated trauma. Twenty ears (10 rabbits) were used in the experiment. The animals were divided into four groups (control, preradiation, low dose, and high dose). Hematoma was produced by pounding the lateral side of the auricle 10 times with a 50-g weight at a height of 15 cm. The thickness of the injured and uninjured sites was measured, and histological analysis was performed for each group. The thickness of the ears of the irradiated groups was significantly less than the control group. The authors think that radiation treatment of repeatedly injured ears could prevent ear deformity, and could possibly be an adjunctive form of management of cauliflower ear in addition to hematoma evacuation and compression therapy.

CD99 regulates the transport of MHC class I molecules from the Golgi complex to the cell surface

The down-regulation of surface expression of MHC class I molecules has recently been reported in the CD99-deficient lymphoblastoid B cell line displaying the characteristics of Hodgkin's and Reed-Sternberg phenotype. Here, we demonstrate that the reduction of MHC class I molecules on the cell surface is primarily due to a defect in the transport from the Golgi complex to the plasma membrane. Loss of CD99 did not affect the steady-state expression levels of mRNA and protein of MHC class I molecules. In addition, the assembly of MHC class I molecules and the transport from the endoplasmic reticulum to the cis-Golgi occurred normally in the CD99-deficient cells, and no difference was detected between the CD99-deficient and the control cells in the pattern and degree of endocytosis. Instead, the CD99-deficient cells displayed the delayed transport of newly synthesized MHC class I molecules to the plasma membrane, thus causing accumulation of the molecules within the cells. The accumulated MHC class I molecules in the CD99-deficient cells were colocalized with alpha-mannosidase II and gamma-adaptin in the Golgi compartment. These results suggest that CD99 may be associated with the post-Golgi trafficking machinery by regulating the transport to the plasma membrane rather than the endocytosis of surface MHC class I molecules, providing a novel mechanism of MHC class I down-regulation for immune escape.

Evaluation of pH inhibition effect on activated sludge by the pseudo toxic concentration (CPT) concept model

It is generally accepted that the inhibition effect of pH on activated sludge follows the non-competitive inhibition kinetics. But the non-competitive inhibition kinetic equation cannot be directly applied to pH inhibition, due to the difficulty in quantification of pH as a term of inhibitor concentration. So, many empirical equations were developed especially for acidic condition to describe pH inhibition effect. In this research, the pseudo toxic concentration (CPT) concept model to quantify pH inhibition effect on activated sludge was proposed and compared with other existed models. Prediction of performance, presented by Prediction Accuracy and Prediction Accuracy Index, showed that the CPT concept model can explain the reduction of the maximum specific growth rate (mu max) more accurately than any other models do at a wide range of pH. The CPT concept model was applicable not only to activated sludge but also to specific microorganism groups, such as nitrifier, less acidophilic species and nitrifying biofilm.

Anti-apoptotic role of Bfl-1 in staurosporine-treated B-lymphoblastic cells

To examine the relationship between the expression level of Bfl-1 and the susceptibility to staurosporine-induced apoptosis in B-lymphoblastic cells, we tested cell survival in 4 cell lines: 2 that are Bfl-1-nonexpressing (Reh and JM-1) and 2 that are Bfl-1-expressing (IM-9 and Wil2-NS). Reh and JM-1 showed apoptosis levels of 62% (Reh) and 30% (JM-1) as early as 3 hours after treatment with staurosporine, whereas IM-9 and Wil2-NS showed apoptosis levels of only 40% and 26%, respectively, even after 1 day of treatment with staurosporine. Either induced expression of Bfl-1 with 12-o-tetradecanoyl phorbol-13-acetate or exogenous expression of Bfl-1 by transfection in Reh cells promoted cell survival. These results suggest that expression of Bfl-1 contributes to regulating apoptosis in the B-cell lines we examined.

Identification and characterization of the major allergens of buckwheat

BACKGROUND

Buckwheat (BW) has been recognized as a common food allergen in Korea, Japan, and other countries. Until now, serologic findings of BW food-allergic patients and its major allergenic components have not been clarified. In this study, we analyzed the serologic findings of BW food allergy and characterized its major allergenic components.

METHODS

Nineteen BW-allergic subjects with symptoms after BW ingestion and 15 asymptomatic control subjects with positive skin prick test to BW were recruited. BW-specific IgE was measured with the Pharmacia CAP kit. Allergenic components of BW were analyzed by IgE immunoblotting, periodate oxidation, two-dimensonal PAGE, and sequencing of N-terminal amino acids.

RESULTS

From the BW-allergic patients and asymptomatic controls, the sensitivity (100%), specificity (53%), and negative (100%) and positive predictive values (73%) of Pharmacia CAP specific IgE for diagnosis were estimated. The prevalence of IgE binding to 24-kDa (pI 8.3), 16-kDa (pI 5.6), and 9-kDa (pI 5.0/ 6.0) allergens was higher than 50% in BW-allergic and asymptomatic subjects. However, the specific IgE to split 19-kDa (pI 6.5/7.0) allergens were more specifically found in BW-allergic patients than in asymptomatic subjects (78% vs 7%). N-terminal amino-acid sequences of 19-kDa and 16-kDa allergens showed moderate and weak homology to the 19-kDa globulin protein of rice and alpha-amylase/trypsin inhibitor of millet, respectively. The N-terminus of the 9-kDa isoallergens were not different from each other and were identified as the reported trypsin inhibitors of BW. Attenuation of the IgE binding to the 9-kDa allergen was found with periodate oxidation.

CONCLUSIONS

The allergens of 24, 19, 16, and 9 kDa are strong candidates to be major allergens, and the 19-kDa allergen was relatively specific for BW-allergic patients. Moreover, measurement of BW-specific IgE and the features of immunoblotting should be very useful tools in the diagnosis of BW allergy.

A case of extragenital lichen sclerosus following Blaschko's lines

Extragenital lichen sclerosus is most common on the neck, shoulders, and upper portion of the trunk. A 20-year-old Korean man had asymptomatic, well-demarcated, linear violaceous plaques on the left lateral chest, in a pattern corresponding to the lines of Blaschko. We describe a case with a pattern of extragenital lichen sclerosus following Blaschko's lines.

Epstein-Barr virus in gastric carcinomas with lymphoid stroma

AIMS

To clarify the relationship between the Epstein-Barr virus (EBV) and gastric carcinoma with lymphoid stroma (GCLS) in Koreans, and to characterize the EBV-positive GCLS.

METHODS AND RESULTS

EBV infection was examined using EBER in-situ hybridization and polymerase chain reaction in 45 cases of GCLS among Koreans, and in 292 consecutive cases of gastric carcinomas without lymphoid stroma (non-GCLS) as controls. EBV infection was found in 30 tumours (67%) of GCLS and 10 tumours (3.4%) of non-GCLS (P < 0.05). EBV-positive GCLS was more prevalent in males, poorly differentiated histological type and diffuse type in Lauren's classification, and tended to be located more in the middle third of the stomach than EBV-negative GCLS (P < 0.05). p53 overexpression was observed in 22% of GCLS (17% of EBV-positive GCLS and 33% of EBV-negative GCLS), and 34% of non-GCLS (EBV-positive GCLS vs. non-GCLS: P = 0.056). The survival of the patient with GCLS was not correlated with EBV infection or p53 immunoexpression (follow-up period: 11-97 months).

CONCLUSIONS

GCLS in Koreans is strongly associated with EBV infection. The prognosis in GCLS is not dependent upon either the status of EBV infection or the status of p53 immunoexpression.

Structural characterization of beta-D-(1 --> 3, 1 --> 6)-linked glucans using NMR spectroscopy

Nondestructive structural analysis of a series of beta-D-(1 --> 3, 1 --> 6)-linked glucans (laminaran, curdlan, yeast glucan, scleroglucan, etc.) was performed using two-dimensional NMR spectroscopy. The relative ratios of H-1 at different AGUs provided the information about DPn and DB. The alpha-, and beta-anomeric protons on reducing terminals were assigned at 5.02 to approximately 5.03 ppm (J 3.6 to approximately 3.7 Hz), and 4.42 to approximately 4.43 ppm (J 7.6 to approximately 7.9 Hz), respectively, whereas the H-1 protons of internal AGUs and beta-(1 --> 6)-branched AGUs appeared at 4.56 to approximately 4.59 ppm (J 7.6 to approximately 7.8 Hz), and 4.26 to approximately 4.28 ppm (J 7.6 to approximately 10.6 Hz), respectively, in a mixed solvent of 6:1 Me2SO-d6-D2O at 80 degrees C. In the solvent, the OH peaks were eliminated from the spectra allowing the H-1 protons to appear clearly. In addition, the nonreducing terminal H-1 and H-1 at the AGU next to reducing terminal could be assigned at 4.45 to approximately 4.46 ppm (J 7.8 to approximately 7.9 Hz), and 4.51 to approximately 4.53 ppm (J 7.8 Hz), respectively. The DPn of the laminaran was 33 (polydispersity 1.12) and the DB was 0.07. The number of glucosyl units in the side chain of laminaran is more than one. The DPn and DB of the water-insoluble yeast glucan were 228 and 0.003, respectively. However the DPn of water soluble yeast glucan phosphate and curdlan was changed upon the number of freeze-drying processes and the content of water in the mixed solvent, respectively. And the DB of those were calculated as 0.02 and 0, respectively. The DB of scleroglucan was precisely calculated as 0.33, compared with the previously reported data. The H-1s at different AGUs of the various beta-D-(1 --> 3, 1 --> 6)-linked glucans having different DB can be exactly assigned by their chemical shifts in the mixed solvent system. This NMR analysis can be effectively used to determine the DP and DB of polysaccharides in a simple and non-destructive manner.

Overexpression of p53 and rare genetic mutation in mesenchymal chondrosarcoma

Mesenchymal chondrosarcoma is extremely rare and accounts for less than 2% of all chondrosarcomas. The pathogenesis and the molecular genetic events which contribute to the development of mesenchymal chondrosarcoma are not well elucidated, due in part to the lack of sufficient tumor tissue available. To characterize the involvement of the p53 gene abnormality in this disease, we analyzed expression and sequence alteration of p53 by immunohistochemical analysis of the protein expression and quantitative DNA/PCR and PCR-SSCP assays of the gene in 33 paraffin-embedded tissue specimens. Immunohistochemical analysis demonstrated that 19 (61.3%) of 31 had nuclear overexpression of p53 while 7 (22.6%) showed cytoplasmic expression. The remaining 5 (16.1%) were negative for p53 staining. The nuclear positivity of p53 was observed within a range of 22-64% (mean 37.3%) of tumor cells and showed a positive staining in mesenchymal components as well as chondroid components. Quantitative DNA/PCR analysis revealed that 6 (18.2%) of the 33 specimens carried significantly reduced or undetectably low levels of p53 indicating the genomic deletion of the gene in these tumors. In contrast, however, DNA/PCR-SSCP analysis failed to detect any types of mutations resulting in amino acid substitution within exons 5-9 regions of the gene. Taken together, our data suggests that genetic alteration of p53 is a relatively rare event in mesenchymal chondrosarcomas but substantial fraction of this type of tumors carries abnormal overexpression of p53, which might result from as yet unidentified epigenetic mechanism(s).

Prevalence of atopic dermatitis in Korea

This study was designed to estimate the prevalence and personal or family history of atopic dermatitis in school children in 3 areas of Korea: urban (Seoul), industrial (Ulsan) and rural (Chunchon). On the basis of dermatologists' physical examinations and the questionnaires completed by parents or guardians, the prevalence of atopic dermatitis was estimated to be 3.3% in the industrial area, 6.6% in the rural area and 7.8% in the urban area. The frequency of atopic dermatitis decreased with age and was significantly lower in the industrial area than in the rural and urban areas.

Transforming growth factor-beta induces apoptosis in activated murine T cells through the activation of caspase 1-like protease

Transforming growth factor-beta (TGF-beta) has been known as a potent immunosuppressive cytokine that can induce apoptosis in lymphoid cells. We established an IL-2-independent cell line, CTLL-2A, from murine T cell line CTLL-2. CTLL-2A expressed higher levels of CD95, CD69, and CD18 molecules than CTLL-2 did, suggesting a more activated state in CTLL-2A than in the CTLL-2 by phenotype. Exposing both CTLL-2 and CTLL-2A to TGF-beta results in differential apoptosis patterns defined by DNA fragmentation and plasma membrane alteration. Among the bcl-2 family members, bcl-2, bcl-w, and bcl-x(L) were also differently expressed in these two cell lines. In CTLL-2A, bcl-x(L) was amplified as a major anti-apoptotic molecule, and TGF-beta-induced cell death was more enhanced than in the original cell line. Caspase 1-like protease was activated by TGF-beta treatment and consequently it cleaved bcl-x(L) in CTLL-2A. TGF-beta-induced DNA fragmentation and cleavage of bcl-x(L) were inhibited by pretreatment with tetra peptide caspase 1 inhibitor, YVAD.cmk. These findings suggest that TGF-beta induces cell death in activated murine T cells through cleavage of bcl-x(L) via activated caspase 1-like protease, which may act as an important executor in that process.

Clinicopathologic study of Castleman's disease in Korea

Castleman's disease represents an atypical lymphoproliferative disorder, infrequently associated with various immunologic abnormalities or subsequent development of malignancy such as Kaposi sarcoma, malignant lymphoma and plasmacytoma. Its clinicopathologic features depend on various etiologic factors such as Kaposi sarcoma herpesvirus (KSHV), oversecretion of IL-6, adhesion molecule and follicular dendritic cell dysplasia, etc. To investigate the relationship of Castleman's disease (CD) and the above factors, we reviewed 22 cases of CD. Four cases of KSHV positive CD were detected, all multicentric, plasma cell type, and these cases displayed prominent vascular proliferation, characteristic 'Kaposi-like lesion'. IL-6 and CD54 positive mononuclear cells were scattered in interfollicular areas of KSHV positive cases. Follicular dendritic cell hyperplasia, vascular proliferation, expression of IL-6 and CD54 did not show any significant difference between solitary vs multicentric type, and plasma cell type vs hyaline vascular type. Our study suggests that KSHV positive CD reveals unique pathologic features, and the probable relationship of KSHV and IL-6 and CD54 is discussed.

Skin is the frequent site for involvement of peripheral T-cell and natural killer cell lymphomas in Korea

We have studied the clinicopathological features of 19 Korean cases of peripheral T-cell and natural killer (NK) cell lymphomas, not including mycosis fungoides. Primary cutaneous involvement was demonstrated in eight of these 19 cases, and we recognized four clinicopathologic subtypes among these eight patients: nasal type NK/T cell lymphoma, three cases; primary cutaneous CD30 positive anaplastic large cell lymphoma, two cases; subcutaneous panniculitis-like T-cell lymphoma, one case; lymphoma with hydroa vacciniforme-like cutaneous lesions, two cases. We did not, however, encounter any cases of HTLV-associated adult T-cell lymphoma/leukemia, which is common in Taiwan and Japan. EBV-associated lymphoma is the most prominent type of peripheral T-cell and NK cell neoplasm involving the skin in Korea.

Near drowning: thin-section CT findings in six patients

PURPOSE

The purpose of this study was to assess the thin-section CT findings of near drowning in six patients.

METHOD

Thin-section (1 mm collimation) CT scans of six patients who experienced near drowning were retrospectively analyzed. The CT scans were performed 0-5 days (median 1 day) after near drowning.

RESULTS

Thin-section CT findings included bilateral patchy or diffuse areas of ground-glass attenuation (n = 6) with geographic pattern (n = 3) and fine intralobular reticular opacities ("crazy-paving" appearance) (n = 3), ill-defined centrilobular nodules (n = 4), and air-space consolidation (n = 1). Distribution of ground-glass attenuation was predominantly central (n = 4) or diffuse (n = 2). Interstitial pulmonary emphysema and pneumomediastinum were present in two patients.

CONCLUSION

The thin-section CT findings of near drowning consist of ground-glass opacities with or without associated reticular opacities and centrilobular nodules.

Enzymic methylation of arginyl residues in -gly-arg-gly- peptides

N(G)-Methylation of arginine residues in many nucleic-acid-binding proteins are formed post-translationally, catalysed by S-adenosylmethionine:protein-arginine N-methyltransferase in their glycine-rich and arginine-rich motifs. The amino acid sequences of the stimulator of HIV-1 TAR (Tat-responsive element) RNA-binding protein (SRB) and fibronectin also show the presence of the internal -Gly-Arg-Gly- (-GRG-) sequence, which is potentially methylatable by the methyltransferase. To investigate the sequence requirement for methylation of these proteins, several synthetic oligopeptides with different chain lengths and sequences similar to the -GRG- regions of SRB and fibronectin were synthesized. Whereas the heptapeptide AGGRGKG (residues 16-22 in SRB) served as the methyl acceptor for the methyltransferase with a K(m) of 50 microM, the 19-mer peptide (residues 10-28 in SRB) was methylated with a K(m) of 8.3 microM, indicating that a greater peptide chain length yields a better methyl acceptor. Product analysis of the methylated [methyl-(14)C]SRB-peptide by HPLC indicated the formation of N(G)-monomethylarginine and N(G),N(G)-dimethyl(asymmetric)arginine. Synthetic peptides containing the cell attachment sequence [Arg-Gly-Asp ('RGD')] in fibronectin, GRGDSPK, GGRGDSPK and GGGRGDSPK, were also studied; whereas GRGDSPK was a poor methyl acceptor, the longer peptides were better methyl acceptors. To provide an understanding of the effect of methylation on fibronectin peptide, arginine-unmethylated and methylated GGRGDSPK were compared for their effect on the mitogenesis induced by beta-hexosaminidase A and an agonistic antibody (mAb(15)) in bovine tracheal smooth-muscle cells; whereas the former inhibited 35-67% of mitogenesis at a concentration of 5-10 microM, the latter did not block mitogenesis. This lack of inhibition by the insertion of a methyl group on the arginyl residue of the cell attachment sequence might be due to the hindrance of the binding of fibronectin peptide to integrins.

Clinical improvement and immunohistochemical findings in severe atopic dermatitis treated with interferon gamma

BACKGROUND

Several clinical studies have focused on the therapeutic effects of interferon gamma (IFN-gamma) in patients with severe atopic dermatitis (AD), although the dosage of recombinant IFN-gamma (rIFN-gamma), therapeutic schedule, and the degree of clinical improvement were different among studies. Although the exact mechanism of action of IFN-gamma therapy in AD is not clear, the beneficial effects of IFN-gamma have been attributed mainly to an immunomodulating effect on the expression of certain immunologic markers.

OBJECTIVE

Our purpose was to study the therapeutic effect of two different dosages of rIFN-gamma on AD and to investigate the change of lesional expression of infiltrating inflammatory cell markers associated with rIFN-gamma therapeutic efficacy.

METHODS

Fifty-one patients with severe recalcitrant AD were treated with rIFN-gamma. Twenty patients were treated with 0.5 x 10(6) IU/m(2) of rIFN-gamma (low-dose [LD] group); 21 patients received 1.5 x 10(6) IU/m(2) of rIFN-gamma (high-dose [HD] group); and 10 patients received placebo. The patients were injected subcutaneously 3 times a week for 12 weeks. Immunohistochemical study was performed in 20 patients of the HD group in the initial visit and after completion of rIFN-gamma therapy with a panel of 14 monoclonal antibodies as markers of inflammatory cells and cytokines.

RESULTS

The disease severity of the 2 groups treated with rIFN-gamma was reduced significantly at the end of treatment compared with that of the placebo group (P<.05). More rapid clinical improvement and more effective treatment outcome were seen in the HD group than in the LD group for the initial 6-week treatment period; however, the clinical improvement in both of the treated groups was stable and maintained after week 8 of treatment. Immunohistochemical findings showed statistically significant reduction in the lesional expression of CD25 and EG2 cells that infiltrated into skin after rIFN-gamma therapy.

CONCLUSION

This study demonstrated that rIFN-gamma therapy for AD is safe and effective. In the early phase of therapy, a higher dosage of rIFN-gamma is more effective; and for the maintenance of clinical improvement, a lower dosage of rIFN-gamma is recommended when high cost and effectiveness of rIFN-gamma are considered. The therapeutic efficacy of rIFN-gamma in AD might be in part related to the decreased number of CD25(+) and EG2(+) inflammatory cells infiltrated into skin.

Microsatellite instability and Epstein-Barr virus infection in gastric remnant cancers

Clinicopathological analysis, microsatellite analysis, detection of Epstein-Barr virus (EBV), and immunohistochemistry on p53 protein were performed in 26 cases of gastric remnant cancer (GRC). They were divided into two groups; Group A (n = 14) who had undergone a primary gastrectomy for benign gastric disease, and Group B (n = 12) who had undergone the same operation for gastric cancer. EBV infection was present in 29% of Group A, 8% of Group B and 6% of the conventional gastric carcinoma (CGC) (Group A vs CGC, P = 0.01). Microsatellite instability (MSI) was found in 7% of Group A, 25% of Group B, and 9% of the CGC (Group B vs CGC; P = 0.08). p53 Overexpression was observed in 46% of the GRC and 33% of the CGC. p53 Overexpression was observed in 90% of the intestinal type of GRC, but in only 20% of the diffuse type of GRC (P = 0.002). The cancer stage was a significant factor in the univariate analysis of survival (P = 0.04). In conclusion, GRC is different from CGC in terms of MSI or EBV association. The pathogenetic differences between the two groups require further investigation. EBV infection may have been involved in the carcinogenesis of Group A. MSI may be an important factor in the carcinogenesis of metachronous multiple gastric cancer (Group B).

Cutaneous sinus tract from remaining tooth fragment of edentulous maxilla

Cutaneous sinus tract of dental origin usually arises from chronic dental infections. These tracts usually appear as suppurative lesions of the chin or neck. Because many patients with this lesion do not have any complaints of oral symptoms, these lesions are often diagnosed incorrectly and overlooked, and are also treated ineffectively. A case of an unusual presentation of a chronic suppurative granuloma on nasolabial fold, which originated from the remaining tooth fragment of edentulous maxilla, is reported. Treatment with removal of the tooth fragment as well as the sinus tract resulted in complete healing of the lesion. This report emphasizes the importance of awareness of the possible dental origin of facial sinuses, despite their unusual location.

Generalized atrophic benign epidermolysis bullosa--poor prognosis associated with chronic renal failure

Generalized atrophic benign epidermolysis bullosa (GABEB) is an autosomal recessive form of junctional epidermolysis bullosa, with milder clinical features than the Herlitz subtype. A 25-year-old man presented with the clinical and histological findings of GABEB. At the initial visit, laboratory tests revealed that he also had chronic renal failure (CRF). Usually, GABEB has a good prognosis. However, in this case, the patient had CRF as an associated complication. He died of an intracranial haemorrhage combined with sepsis after 3 weeks of hospitalization. This case suggests that renal complications can occur in this relatively mild form of epidermolysis bullosa, and may contribute to morbidity and premature mortality.

Adult T cell leukemia/lymphoma with lymphopenia in a Korean

We experienced a case of adult T cell leukemia/lymphoma (ATLL) in a 48-year-old Korean female, who has never been abroad since birth and no history of blood transfusion. The patient had hypercalcemia and multiple lymphadenopathy. Histopathologic study of left cervical lymph node (LN) and bone marrow (BM) revealed that infiltrates of malignant lymphoid cells were composed of small, medium and large cells with pleomorphic nuclei. Smears of peripheral blood (PB) showed lymphopenia (16%) with the appearance of a few atypical lymphoid cells (less than 2%), but not the typical clover leaf cells seen in ATLL. Immunophenotypic study of LN and BM revealed T cell phenotype. PB showed increased CD4+ T cell (T(H), CD3/CD4+, 57%) and decreased CD8+ T cell counts (T(S), CD3/CD8+, 6.7%). The sera of the patient and her family were reactive for HTLV-I antibody. The specific sequences of pol, env, and tax of HTLV-I DNA were detected in the lymphoma cells and peripheral blood mononuclear cells (PBMC) using polymerase chain reaction. Ultrastructural examination of PBMC confirmed numerous type c virus particles in extracellular space. This case was an acute type of ATLL without overt leukemic features in PB. Despite chemotherapy and intensive conservative treatment, she died 3 months after admission.

Collagen-to-smooth muscle ratio helps prediction of prognosis after pyeloplasty

PURPOSE

We quantitatively evaluated the collagen-to-smooth muscle tissue matrix ratio in ureteropelvic junction obstruction, and compared the ratio with the degree of obstruction, patient age and postoperative renal recovery.

MATERIALS AND METHODS

We analyzed histological sections from 65 patients with ureteropelvic junction obstruction and 6 normal controls. Morphological and functional grading systems were adapted to determine the degree of renal obstruction. To examine smooth muscle and collagen tissue, sections were stained using Masson's trichrome. Two distinct populations of collagen versus smooth muscle were identified and the tissue matrix ratio was calculated by color image analysis.

RESULTS

The mean tissue matrix ratio plus or minus standard deviation was 1.32+/-0.79 in all patients with ureteropelvic junction obstruction but only 0.30+/-0.10 in normal controls (p <0.0001). It appeared that the lower the tissue matrix ratio, the better the improvement in postoperative hydronephrosis (r = -0.50, p = 0.0001). Better recovery of renal function after pyeloplasty was observed with a decrease in the tissue matrix ratio (r = -0.43, p = 0.0004). We divided patients according to the tissue matrix ratio into groups 1--ratio 1 or less, 2--greater than 1 to 1.5 and 3--greater than 1.5 to determine a more detailed and clinically applicable correlation of tissue matrix ratio with postoperative renal functional changes. Better improvement in postoperative renal function was observed in group 1 than in group 3 (p = 0.002). Also, the tissue matrix ratio increased with patient age (r = 0.33, p = 0.007).

CONCLUSIONS

Since our data represent an objective and quantitative parameter associated with ureteropelvic junction obstruction, we believe that our findings may help to predict the prognosis after pyeloplasty.

Regulation of chicken protein tyrosine phosphatase 1 and human protein tyrosine phosphatase 1B activity by casein kinase II- and p56lck-mediated phosphorylation

Protein tyrosine phosphorylation and dephosphorylation are important in the regulation of cell proliferation and signaling cascade. In order to examine whether phosphatase activity of CPTP1 and HPTP1B, typical nontransmembrane protein tyrosine phosphatase, could be controlled by phosphorylation, affinity-purified PTPs were phosphorylated by CKII and p56lck in vitro. Phosphoamino acid analysis revealed that CPTP1 was phosphorylated on both serine and threonine residues by CKII, and tyrosine residue by p56lck. Phosphatase activity of CPTP1 was gradually increased by three-fold concomitant with phosporylation by CKII. Phosphorylation of HPTP1B by CKII resulted in quick two-fold enhancement of its phosphatase activity within 5 min of incubation and remained in that state. In the presence of CKII inhibitor, heparin or poly(Glu.Tyr), both phosphorylation and enhancement of phosphatase activity of CPTP1 and HPTP1B were mostly blocked. p56lck catalyzed tyrosine phosphorylation of CPTP1 and HPTP1B was only observed by inhibiting the intrinsic tyrosine phosphatase activity. Taken together, these results indicate that CPTP1 or HPTP1B possesses a capability to regulate its phosphatase activity through phosphorylation processes and may participate in the cellular signal cascades.

The effects of substance P and vasoactive intestinal peptide on interleukin-6 synthesis in cultured human keratinocytes

Interleukin-6 (IL-6) is a cytokine implicated as a key mediator of immune and inflammatory responses in psoriasis. Recent studies have shown that neuropeptides, substance P (SP) and vasoactive intestinal peptide (VIP), can modulate a production of IL-6 from cells, such as monocytes and astrocytes, participating in an immune reaction. The aim of this study was to assess the role of the neuropeptides on cytokine production of keratinocytes in physiologic or pathologic conditions. Cultured human keratinocytes derived from normal foreskin and psoriatic lesions were treated with various concentrations of SP or VIP, in the presence or absence of fetal bovine serum. The secretion of IL-6 by the treated keratinocytes was analyzed by enzyme-linked immunosorbent assay. Although neither SP nor VIP, by itself, was able to induce IL-6 synthesis in cultured human keratinocytes, we have found that SP, not VIP, significantly reduced 5% fetal bovine serum-induced IL-6 production in time- and dose-dependent fashion. This down-regulatory effect of SP was reversed by spantide, a SP antagonist. Lesional psoriatic keratinocytes showed a similar, but weaker, response when compared with normal keratinocytes. These data suggested that SP might modulate IL-6 synthesis of keratinocytes in either physiologic or pathologic conditions such as psoriasis.

Amino acid sequence analysis of bitter peptides from a soybean proglycinin subunit synthesized in Escherichia coli

The cDNA encoding A1aB1b proglycinin was expressed in E. coli, for the efficient isolation of a single peptide responsible for the bitterness. The 55-kD proglycinin was highly purified, hydrolyzed, and further purified through a series of chromatographic steps to yield fractions with the major bitter peptides. The most bitter-tasting fractions contained peptides with average molecular weights lower than 1,700 Da. An analysis of the amino acid sequences indicated that many small bitter peptides (< 1,000 Da) are composed of uncharged polar amino acids as well as hydrophobic amino acids, with a charged residue often being present at either end. This suggests the involvement of a certain structural requirement in taste perception.

FNAC of malignant lymphoma in an area with a high incidence of T-cell lymphoma. Correlation of accuracy of cytologic diagnosis with histologic subtype and immunophenotype

OBJECTIVE

To analyze the usefulness of fine needle aspiration cytology on malignant lymphoma in an area with a high incidence of T-cell lymphoma and to correlate the accuracy of cytologic diagnosis with histologic subtype and immunophenotype.

STUDY DESIGN

We retrospectively studied the usefulness of fine needle aspiration cytology in the diagnosis of 49 cases of nodal and extranodal non-Hodgkin's lymphoma (NHL) and seven cases of Hodgkin's disease in a total of 56 patients in whom subsequent excisional biopsy revealed lymphoid malignancy. Slides showing the results of cytologic investigation were reviewed together with the information on which histologic diagnosis was based. On the basis of pathologic variables, such as prognostic groups based on the Working Formulation, so-called grade, cell size based on the modified Rappaport classification, and--in cases of NHL--immunophenotype, the accuracy of original and reviewed cytologic diagnoses was compared.

RESULTS

Of the 49 cases of NHL, 8 (16.3%) were inadequate for cytologic diagnosis, and malignant lymphoma was diagnosed or suspected in 36 (73.5%), excluding inadequate specimens; the diagnostic accuracy for NHL was 87.8%. In high grade cases, malignant lymphoma was more easily diagnosed or suspected than in those that were low or intermediate grade. The rate of inadequate cases was highest in the "mixed small and large cell" category, and cases that were "false negative" were either composed entirely of small cells or contained a small cell component. Cytologic diagnosis or suspicion of malignant lymphoma was easily obtained in the "large cell" category, followed by mixed small and large cell and "small cell." Aspirates from non-B-cell type were more frequently acellular than those of B-cell type; with regard to diagnostic accuracy, however, there was no noticeable difference between the two immunophenotypes.

CONCLUSION

In many cases in the mixed small and large cell category or where the immunophenotype was non-B, the aspirate was inadequate, and no definitive diagnosis was possible. Many of our cases of T-cell lymphoma were mixed small and large cell, and in Korea, where the incidence of extranodal and T-cell lymphoma is high, the usefulness of FNAC for the initial diagnosis of malignant lymphoma is limited. For a definitive diagnosis, biopsy is required.

Clinicopathological analysis of 501 non-Hodgkin's lymphomas in Korea according to the revised European-American classification of lymphoid neoplasms

AIMS

The clinical relevance of the Revised European-American Classification of Lymphoid Neoplasms (REAL) is still debated. To test the clinical validity of the REAL classification in Korea, where the incidence of T-cell lymphoma is higher, we investigated the clinicopathological features of non-Hodgkin's lymphoma (NHL) from Korea Cancer Center Hospital.

METHODS AND RESULTS

Five hundred and one patients with NHL were reclassified according to the REAL classification and clinicopathologically analysed. Immunophenotypically, B-cell lymphoma accounted for 67.9% and T- and NK-cell type for 30.5%. Approximately 48.5% of cases were forms of diffuse large B-cell lymphoma (DLBCL), while only 5.4% were follicular lymphoma. Peripheral T-cell lymphoma unspecified (PTCL-U; 10.8%) and angiocentric lymphomas (11.8%) comprised the majority of T-cell lymphomas. Most of the angiocentric lymphomas presented with localized nasal/nasopharyngeal or tonsillar primaries. All peripheral T-cell lymphomas (PTCL) showed a significantly low overall survival compared to DLBCL (P = 0.02, log rank). Overall survival rates for DLBCL and PTCL-U were also significantly different (P = 0.0043, log rank), though for DLBCL and angiocentric lymphoma there was no significant difference (P = 0.2142, log rank). Angiocentric lymphoma, however, was characterized by a shorter median survival time than DLBCL (54 months vs. 96 months). Among DLBCL patients according to the REAL classification, overall survival was significantly better in nonimmunoblastic type (intermediate-grade, WF-F,G) as compared to large cell immunoblastic type (high-grade, WF-H) (log rank, P < 0.001). The morphological distinction of the immunoblastic and nonimmunoblastic among DLBCL of the REAL classification bears significant prognostic relevance worthy of further consideration.

CONCLUSION

We conclude that lineage assignment (T vs. B) in the REAL classification is a clinically important distinction, but that it is necessary to subdivide the broad category of DLBCL.

Identification and characterization of the major allergen of the Humulus japonicus pollen

BACKGROUND

Pollen of Humulus japonicus has been known as one of the important causes of pollinosis in Korea and China. To date, the major allergen of H. japonicus has not been determined.

OBJECTIVE

To identify the major allergen of H. japonicus pollen and characterize its biochemical properties.

METHODS

With the sera of 29 patients reactive to H. japonicus, the major allergen of H. japonicus was determined from the results of IgE immunoblotting and ELISA inhibition. The biochemical properties of the major allergen of H. japonicus were evaluated by lectin blotting assay and 2-dimensional PAGE blot. N-terminal amino acid sequences were determined by the Edman degradation method. The suggested major allergen was purified by DEAE anion exchange and gel filtration chromatography.

RESULTS

Twenty-nine sera contained IgE bound to the 10, 16, 20, 29 and 42 kDa proteins of H. japonicus in immunoblot analysis. A protein of 10 kDa was the most prevalent allergen in the sera of H. japonicus-reactive patients (72%). The ELISA optical density of H. japonicus-specific IgE was not inhibited by pollen extracts of birch, oak, rye grass and mugwort. The 10-kDa allergen was neither stained with PAS nor bound with ConA and five other lectins. The isoelectric point of the 10-kDa allergen was approximately pH 5.1. We sequenced the N-terminal amino acids of the 10-kDa allergen, which was not homologous with any previously characterized allergen. The 10-kDa allergen could be purified with DEAE anion exchange and gel filtration chromatography. Maximum inhibitions of H. japonicus-specific IgE ELISA by whole extract of H. japonicus and purified 10-kDa allergen were more than 97 and 88%, respectively, while the 50% inhibitory concentration of the whole extract of H. japonicus and purified 10 kDa were 38 and 20 ng/mL, respectively.

CONCLUSION

The 10-kDa peptide could be a major allergen of H. japonicus. Its isoelectric point was 5.1 and it did not bind with lectins. The N-terminal amino acid sequence of the 10-kDa major allergen was also determined.

Rapidly developing T-cell posttransplantation lymphoproliferative disorder

Posttransplantation lymphoproliferative disorder (PTLD) of T-cell origin has been rarely described in chronically immunosuppressed allograft recipients. We report a case of renal PTLD of a T lineage that occurred shortly after transplantation under a triple-immunosuppressive regimen. Renal graft biopsy performed 58 days posttransplantation showed extensive interstitial infiltrates of polymorphic lymphoid cells, which expressed the UCHL-1 and CD3 markers for T-cell lineage. The clonal nature of the T cells in renal tissue was identified by showing rearrangement of the T-cell receptor gamma chain genes using a polymerase chain reaction (PCR). DNA extracted from the graft biopsy specimen did not show the sequences of human T-cell leukemia virus type 1 (HTLV-1) by PCR. Signals for Epstein-Barr virus (EBV) infection in renal tissue were not shown by in situ hybridization. After the reduction of immunosuppressive therapy, regression of PTLD lesion and development of rejection were shown in the second graft biopsy and graftectomy specimen. The extreme rarity of rapidly developing T-cell PTLD in a renal allograft prompted us to write this report.

Lymph node involvement rate in low-grade gastric mucosa-associated lymphoid tissue lymphoma--too high to be neglected

BACKGROUND/AIMS

Anti-Helicobacter pylori (H. pylori) treatment for low-grade gastric mucosa-associated lymphoid tissue (MALT) lymphoma has been the subject of attention. The aim of this study was to determine the proportion of such cases which could be suitable candidates for H. pylori eradication for the purpose of cure; we focused on gross morphology and lymph node metastasis.

METHODOLOGY

We retrospectively reviewed the medical records of 53 patients diagnosed and treated for gastric MALT lymphoma at Seoul National University Hospital between 1992 and 1996.

RESULTS

According to Isaacson's classification, 60% of cases were low-grade, and H. pylori was detected in 88% of them. In low-grade disease, gastroscopy revealed superficial lesions in 56% of cases, ulcerofungating lesions were found in as much as 19%, and ulceroinfiltrating in 25%. Even in low-grade disease, invasion of proper muscle, or deeper, was seen in 28% of patients, and lymph node involvement in 36%; even in low-grade disease confined to mucosa and submucosa, the rate of lymph node involvement was 40%. All cases which, on gastroscopy, appeared to be gastritis or benign ulcer-like lesions were free of lymph node metastasis, but in low-grade disease, this proportion was only 16%. In 33% of cases, pre-operative clinical stage I--as shown by abdominal CT--was found post-operatively to be stage II. The negative predictive value of lymph node detection by CT was 68%.

CONCLUSIONS

In low-grade gastric MALT lymphoma, the lymph node involvement rate was too high to be neglected. In detecting lymph node metastasis, the diagnostic accuracy of CT was too low. The proportion of suitable candidates for anti-H. pylori treatment for low-grade gastric MALT lymphoma was not high, and in clinical practice, anti-H. pylori treatment in such cases should at present be very carefully applied.

Head and neck dermatitis: the role of Malassezia furfur, topical steroid use and environmental factors in its causation

The aetiology of head and neck dermatitis (HND), one subgroup of postpubertal atopic dermatitis (AD), is still unclear. The aim of this study was to evaluate the influence on HND of common environmental factors, long-term topical steroid use, and the role of Malassezia furfur infection. Relevant information was obtained from 100 patients with HND attending our dermatology clinic by means of both physical examinations and questionnaires. Corticosteroid-induced vasoconstriction was estimated by visual scoring of laser-Doppler flowmetry. and the following immunological studies were performed: skin prick test, measurement of total IgE, eosinophil cationic protein, and specific IgE antibodies to several fungal antigens including those of M. furfur. The questionnaire revealed that sweating (81%), heat (71%), dryness (70%), psychic stress (67%), and sun exposure (50%) were responsible for aggravation of skin lesions. The vascular response to topical steroid was reduced in HND patients as compared with that of normal healthy controls (P < 0.05). Fifty-four of 80 patients with HND (68%) had anti M. furfur-specific IgE antibodies and 36 of 80 patients (45%) showed positive skin prick tests for M. furfur. The clinical severity and serum total IgE of HND patients were higher in patients with positive response to anti-M. furfur-specific IgE antibodies than in patients with negative response (P < 0.05). These results suggest that HND can be aggravated not only by M. furfur but also by environmental factors such as sweating, heat, dryness, psychic stress and sun exposure. Furthermore, long-term use of topical steroid might be associated with the development of diffuse erythematous lesions with telangiectasia on the head and neck areas.

Alteration of signal-transducing molecules and phenotypical characteristics in peripheral blood lymphocytes from gastric carcinoma patients

The mechanisms underlying the impaired immune response frequently observed in cancer patients are not fully understood. Alteration of T-cell-associated signal transduction molecules has recently been implicated in immune suppression in tumor-bearing hosts. Furthermore, T cells from tumor-bearing host, irrespective of the presence of the zeta-chain, showed a lack of proliferative activity and cytotoxic function. In the present study, we investigated the expression of the zeta-chain molecule and the p56(lck) and p59(fyn) protein tyrosine kinase (PTK) levels in peripheral blood T lymphocytes (T-PBL) from patients with advanced gastric carcinomas; for this, flow cytometric analysis and immunoblotting, respectively, were used. We also compared the results of flow cytometric analysis of PBL between stomach cancer patients and normal healthy volunteers. In T-PBL from 22 tumor-bearing hosts, significantly reduced zeta-chain expression (16/22, 73%) was observed. Moreover, the expression level of p56(lck) in T-PBL from patients was significantly lower than that of p59(fyn). Flow cytometric analysis of T-PBL indicated a markedly increased CD8+28- cell population in T-PBL from 19 tumor-bearing hosts.

Detection of Epstein-Barr virus in Korean peripheral T-cell lymphoma

One hundred thirty-seven patients with peripheral T-cell lymphomas (PTL) were examined for the presence of Epstein-Barr virus (EBV) using in situ hybridization for EBV-encoded RNA (EBER) and Bam H-fragment, lower strand frame (BHLF) and immunohistochemical stain for latent membrane protein (LMP). EBER was detected in tumor cells in 79 cases (58%); 26/66 PTL, unspecified (39%), 3/4 AILD (75%), 47/51 angiocentric lymphomas (AL) (92%), and 3/13 anaplastic large cell lymphoma (ALCL) (23%) by Revised European-American Lymphoma (REAL) classification. EBER was detected in 17/36 nodal (47%) vs. 62/101 extranodal PTLs (61%); 21/24 nasal, 12/32 Waldeyer's ring, 9/13 gastrointestinal, and 20/32 skin and soft tissue PTL. AL was consistently associated with the highest frequency of EBER among the extranodal PTL: nose (19/20), GI tracts (3/3), skin (14/15), and Waldeyer's ring (11/14). In extranodal lymphomas, coagulative-type zonal necrosis was seen almost exclusively in AL and showed correlation with EBER-positivity (P < 0.01). LMP was detected in 24 among 107 cases tested (22%). No signal for BHLF was detected in 76 cases tested, implying absent or negligible incidence of lytic infection. In conclusion, high incidence of EBV was observed in PTL among Koreans, with predilection for angiocentric lymphomas and extranodal presentation, especially involving nose, skin, and gastrointestinal tract.

Heel pain in children. Diagnosis and treatment

Heel pain in children is common, and its evaluation is challenging. Medical history and physical examination may be unrevealing owing to children's limited communication skills. Often, advanced laboratory and imaging studies are required to make an accurate diagnosis. The most common causes of heel pain in children are apophysitis, enthesopathy, and overuse syndromes such as tendinitis. Juvenile rheumatoid arthritis is relatively uncommon. In very active children, occult fractures must also be evaluated. Pain unrelated to activity may indicate tumors, infection, or congenital problems. In general, heel pain in children is treated nonoperatively. For fractures in particular, children are less likely than adults to receive surgical treatment.

A case of edematous striae distensae in lupus nephritis

A 17-year-old girl with systemic lupus erythematosus presented with painful edematous abdominal striae. She had been treated with systemic steroid for the systemic lupus erythematosus. At the time of presentation, she had abruptly gained 10 kg due to combined lupus nephritis. The histopathologic finding of the edematous striae distensae included dermal edema with separation of collagen fibers and small fragmented elastic fibers. Edematous striae distensae are uncommon but can develop from the combined effects of glucocorticoid and generalized edema.

Eradication of Helicobacter pylori infection did not lead to cure of duodenal mucosa-associated lymphoid tissue lymphoma

Duodenal mucosa-associated lymphoid tissue (MALT) lymphoma is very rare, and little is known about its clinical course or association with Helicobacter pylori infection. This report describes the case of a 76-year-old man with a polypoid mass in the duodenal bulb, diagnosed as low-grade MALT lymphoma. H. pylori infection in the duodenal mucosa was confirmed by histology with silver stain. Endoscopic examination showed that the gross lesion regressed after the eradication of H. pylori despite its histopathologic persistence. Ten months later, however, cervical and intraperitoneal lymphadenopathy and bone marrow involvement was observed, and the pathologic diagnosis of the cervical lymph node was identical with that of the duodenal lesion.

Kaposi's sarcoma-associated herpesvirus in Kikuchi's disease

Kikuchi's disease is a fairly common self-limited disorder among Orientals that usually involves the cervical lymph nodes of young individuals and occurs predominantly in females. Frequently, the disease is associated with fever or flu-like symptoms, an elevated erythrocyte sedimentation rate (ESR), neutropenia, and lymphocytosis with atypical lymphocytes in the peripheral blood, suggesting a viral origin. However, no infectious agent has been identified. The presence of Kaposi sarcoma-associated herpesvirus, known as human herpesvirus 8 (KSHV/HHV 8), was investigated by polymerase chain reaction (PCR) in archival tissue from 26 cases of Kikuchi's disease using published sequences of KSHV/HHV 8 as primers. PCR products were further characterized by Southern blot analysis. Forty reactive lymph nodes and a case of Kaposi sarcoma (KS) were included as negative and positive controls, respectively. Patients consisted of 10 men and 16 women with a mean age of 27 years. All patients were previously healthy and presented with cervical or axillary lymphadenopathy. None were positive for human immunodeficiency virus (HIV) or otherwise immunocompromised. Viral DNA was amplified by PCR in six cases of Kikuchi's disease (23%) and the control KS tissue. Southern blot analysis confirmed that the amplified products were KSHV/HHV 8. In the reactive lymph nodes, no viral genome was amplified by PCR. The presence of DNA sequences of KSHV/HHV 8 in a substantial portion of Kikuchi's disease suggests that KSHV/HHV 8 might play an important role in the pathogenesis of a subset of Kikuchi's disease.

Up-regulation of the expression of major histocompatibility complex class I antigens by plasmid DNA transfection in non-hematopoietic cells

The effect of DNA on the surface expression of major histocompatibility (MHC) class I antigens was examined in non-hematopoietic tumor cell lines. Transfection with plasmid DNA via liposome or electroporation significantly increased the surface expression of MHC class I molecules in a transient manner. Northern blot analysis showed that levels of MHC class I mRNA were increased by DNA transfection, probably via transcriptional activation. In contrast, the expression of the MHC class II and beta-actin genes was not affected, suggesting that the up-regulation of MHC class I expression by plasmid DNA works in a gene-specific manner.