Lack of correlation between expression of Epstein-Barr virus (EBV) latent membrane protein and bcl-2 oncoprotein in vivo

Aims - To evaluate whether there is any correlation between the expression of Epstein-Barr virus (EBV) latent membrane protein (LMP) and oncoprotein bcl-2 in the lymph node biopsy specimens of a Chinese patient with EBV-related reactive lymphoproliferation who later developed T cell lymphoma after a short period of time. Methods - Immunohistochemistry, with a standard alkaline phosphatase anti-alkaline phosphatase (APAAP) method and New Fuchsin as a chromogen, was used for single staining of bcl-2 or LMP. Double immunostaining combining APAAP and indirect immunofluorescence was performed for dual labelling of LMP and bcl-2. Results - bcl-2 was expressed in 10-30% of cells in the first lymph node biopsy specimen (EBV-associated lymphoproliferative disorder) and 30-50% of cells in the second lymph node biopsy specimen (T cell lymphoma). LMP was expressed in the first biopsy specimen but not in the second. Double immunostaining results showed that around 78% of LMP positive cells were bcl-2 negative and 94% bcl-2 positive cells were LMP negative. Among the very small fraction of LMP and bcl-2 double positive cells, the intensity of bcl-2 staining was heterogeneous and was not always stronger than that observed in LMP negative bcl-2 positive cells. Conclusions - The expression of bcl-2 protein is independent of LMP protein status in vivo. Several mechanisms may be involved in EBV associated lymphomagenesis, and bcl-2 induction may occur independently of LMP expression.published_or_final_versio

Aggressive non-Hodgkin's lymphoma: T-cell versus B-cell

This study aimed to define the clinical characteristics, treatment outcome and independent prognostic factors of 144 patients with T- and 357 B-cell non-Hodgkin's lymphomas. Entities with well-defined immunophenotype and clinical characteristics were excluded. Patients with T-cell tumours were younger. T-immunophenotype was associated with more advanced disease and presence of B symptoms. They were also less likely to have bulky disease. Primary nasal lymphomas were usually T-cell while lymphomas arising from the gastrointestinal tract and Waldeyer's ring were mostly B-cell. On univariate analysis, T-immunophenotype was associated with lower CR rate, higher relapse rate and inferior overall survival. On the other hand, multivariate analysis revealed that advanced stage, presence of B symptoms, advanced age, high serum lactate dehydrogenase level and use of non-doxorubicin-containing regimens for induction were associated with poor prognosis. Immunophenotype was not a significant independent prognostic factor.link_to_subscribed_fulltex

Fracture Behavior of Human Mandibular Incisors Following Endodontic Treatment and Porcelain Veneer Restoration

Purpose: Because of existing controversy, the present study investigated the individual and combined effects of endodontic treatment and porcelain veneer restoration on the fracture behavior of human mandibular incisors. Materials and Methods: Forty extracted intact human mandibular incisors were assigned to four groups often with a similar range of labiolingual widths at the cementoenamel junctions. Group A consisted of intact teeth; group B consisted of endodontically treated teeth; group C teeth were restored with labial porcelain veneers; and those of group D were endodontically treated and had labial porcelain veneers. All teeth were subjected to a slow continuous loading test at 30 degrees to the long axis of the teeth and 1 mm below the incisal edge on the labial side. Results: Fracture forces were 415 ± 220 N, 370 ± 89 N, 420 ± 128 N, and 448 ± 156 N for groups A, B, C, and D, respectively. Root fracture was the most common mode of failure. There were no statistically significant differences between the groups in terms of fracture forces and modes of failure. Conclusion: Human mandibular incisors with endodontic treatment and/or porcelain veneer restorations were able to withstand the same magnitude of oblique loading as intact teeth. Endodontic treatment and/or porcelain veneer restoration did not affect the mode of failure of mandibular incisors.link_to_subscribed_fulltex

Nasal lymphoma is a neoplasm of Epstein-Barr Virus infected cytotoxic lymphocytes

Abstrac

Adult Fanconi syndrome in κ light chain myeloma

Distinctive morphological features in both the marrow infiltrate and the kidney were seen in a 52-year-old woman with κ light chain-producing plasma cell myeloma, diagnosed on the basis of multiple osteolytic lesions, the presence of atypical plasma cells in the bone marrow, and monoclonal immunoglobulin production as demonstrated by immunoperoxidase staining on marrow sections. Large focal collections of histiocytes in the bone marrow and the renal proximal tubular epithelium had abundant glassy cytoplasm. Characteristic crystalline inclusions were seen ultrastructurally in both types of cells. It is believed that these crystalline deposits are lysosomal inclusions composed of altered κ light chains taken up by these cells. The renal changes were entirely different from those of myeloma kidneys and were associated with proximal tubular dysfunction of adult Fanconi syndrome without distal tubule abnormality.link_to_subscribed_fulltex

Fracture Behavior of Human Mandibular Incisors Following Endodontic Treatment and Porcelain Veneer Restoration

Purpose: Because of existing controversy, the present study investigated the individual and combined effects of endodontic treatment and porcelain veneer restoration on the fracture behavior of human mandibular incisors. Materials and Methods: Forty extracted intact human mandibular incisors were assigned to four groups often with a similar range of labiolingual widths at the cementoenamel junctions. Group A consisted of intact teeth; group B consisted of endodontically treated teeth; group C teeth were restored with labial porcelain veneers; and those of group D were endodontically treated and had labial porcelain veneers. All teeth were subjected to a slow continuous loading test at 30 degrees to the long axis of the teeth and 1 mm below the incisal edge on the labial side. Results: Fracture forces were 415 ± 220 N, 370 ± 89 N, 420 ± 128 N, and 448 ± 156 N for groups A, B, C, and D, respectively. Root fracture was the most common mode of failure. There were no statistically significant differences between the groups in terms of fracture forces and modes of failure. Conclusion: Human mandibular incisors with endodontic treatment and/or porcelain veneer restorations were able to withstand the same magnitude of oblique loading as intact teeth. Endodontic treatment and/or porcelain veneer restoration did not affect the mode of failure of mandibular incisors.link_to_subscribed_fulltex

Nasal lymphoma is a neoplasm of NK cell and cytotoxic T-lymphocytes

Conference Theme: NK Cells and Natural ImmunityAbstrac

Pathogenesis of gastric lymphoma: The enigma in Hong Kong

Background: Helicobacter pylori (H. pylori) infection has been postulated to be a pathogenetic factor in gastric lymphoma. However, the etiological factors for gastric lymphoma could vary in different populations. Materials and methods: We looked for histological evidence of H. pylori infection in 53 gastrectomy specimens from Hong Kong Chinese patients with primary gastric B-lymphoma. We also screened for Epstein-Barr virus (EBV) in these cases using in situ hybridization with oligonucleotide probes for EBV- encoded small RNA1 and 2. Results: H. pylori was found in 29 of 53 (55%), including 8 of 13 (62%) cases of low-grade lymphoma of mucosa-associated lymphoid tissue (MALT) type. These infection rates in gastric lymphoma are lower than those reported in Western populations (80% 100%) and comparable to that found in healthy Chinese blood donors (55%) or in non-ulcer dyspeptic patients (52% 57%). EBV was found in tumor cells only in one case of high- grade gastric lymphoma with low-grade MALT component which was H. pylori- negative, and in occasional nontumor lymphoid cells in 7 other cases. Conclusions: These results suggest that (1) the role of H. pylori in pathogenesis of gastric lymphoma may vary in different populations: (2) very few gastric lymphomas are associated with EBV; (3) not all low-grade gastric MALT lymphomas are H. pylori-dependent.link_to_subscribed_fulltex