High expression of latent membrane protein 1 of Epstein-Barr virus and BCL-2 oncoprotein in acquired immunodeficiency syndrome-related primary brain lymphomas

Nearly all primary brain lymphomas in acquired immunodeficiency syndrome (AIDS) patients are associated withEpstein-Barr virus (EBV). The role of EBV in lymphomagenesis is not totally elucidated. One possible mechanism is the overexpression of the BCL-2 oncoprotein, because the latent membrane protein 1 (LMP1) has been reported to transactivate the bcl-2 gene in vitro. To study the interrelationship beetween LMP1 and BCL-2 in vivo, we have analyzed and compared their expression in 11 AIDS-related primary brain lymphomas and 57 AIDS- related systemic lymphomas by immunoperoxidase technique on frozen sections. In AIDS-related primary brain lymphoma, LMP1 and BCL-2 were expressed in all cases but 1. All positive cases exhibited morphologic immunoblastic features. In contrast, the only negative case was histologically close to Burkitt's lymphoma. In systemic lymphomas, LMP1 was expressed in 21 cases, whereas BCL-2 was positive in only 3 cases, all of which were extranodal. These results indicate that, in addition to the histologic type, the role of EBV genes and BCL-2 expression in lymphomatous cells differ as a function of their localization. In AIDS- related primary brain lymphomas, this correlation between LMP1 and BCL- 2 overexpression may have a major implication in lymphomagenesis.     

Differential kinetic features by tumour topography in cutaneous small-cell neuroendocrine (Merkel cell) carcinomas

BACKGROUND/OBJECTIVES: Merkel cell carcinomas (MCC) reveal epithelial and neuroendocrine differentiation, but its topographic cell kinetics remains unknown. This study analyses proliferation, apoptosis, and DNA ploidy by topography, features that can help planning therapeutic protocols. This study topographically analyses proliferation, apoptosis, and DNA ploidy. METHODS: We selected 27 small-cell MCCs (expressing one epithelial and two neural markers, with consistent ultrastructural findings) to evaluate mitotic figure counting, Ki-67 index, apoptosis index based on the in situ end labelling of fragmented DNA (using Escherichia coli DNA polymerase I, Klenow fragment), DNA ploidy, and BCL2 and TP53 immuno-expression. At least 50 high-power fields were screened per topographic compartment (superficial or papillary dermis, and deep or reticular dermis), recording average and standard deviation for each variable. Variables were statistically compared in each tumour compartment using analysis of variance and Student's t-test (significant if P < 0.05). RESULTS: MCCs revealed superficial aneuploid DNA content, and no topographic differences for proliferation markers. Apoptosis showed significantly lower values in the deep compartment (average, P = 0.0050, and standard deviation, P = 0.0074), correlating with increased BCL2 and TP53 immuno-expressions. CONCLUSIONS: High homogeneously distributed proliferation and superficial aneuploid DNA content defines MCCs. Apoptosis follows proliferation in superficial compartments, being less variable and proliferation independent in deep compartments, where it is inversely correlated with BCL2/TP53 expression.     

Clinical data in children with meningococcal meningitis in a Spanish hospital

Neisseria meningitidis is the main cause of bacterial meningitis in Spain. Of the 213 children included in this study with meningococcal meningitis, 7 died. Mortality was linked to a shorter time from the first symptom to diagnosis (mean time for fatal cases was 9.5 h, mean time for survivors was 19h, p = 0.034), to deteriorated consciousness (DC) (mortality rate (MR) with DC = 6/87, MR without DC = 1/124, p = 0.02) and to shock (MR with shock = 5/7, MR without shock = 2/206, p < 0.0001). Previous treatment reduced the yield from blood culture (36/54 versus 45/137, p < 0.0001). Positivity in both Gram stain (GS) and cerebrospinal fluid (CSF) culture increased with longer duration of symptoms (mean GS+= 25h, GS^-= 16h, p = 0.004; CSF+= 20h, CSF^-= 12h, p = 0.001), and blood culture (BC) gave more positive results when carried out earlier (mean BC+= 14 h, BC = 24 h, p < 0.001). Reduced susceptibility to penicillin was seen in 34% of the strains, and rapidly evolving forms were responsible for most of the deaths; reduced susceptibility was more frequent among strains responsible for death or sequelae (9/15 = 60%) as compared with the more harmless strains (69/ 215 = 32%) ( p = 0.04). The progressive reduction of susceptibility to penicillin indicates that it should be replaced by a third-generation cephalosporine.     

The spectrum of ultrasonic findings in endometriosis

Ten cases of endometriosis presenting as pelvic masses are reviewed. Ultrasonically, these lesions were classified into three categories: cystic, mixed, and solid. In the cystic pattern, none had the smooth, well-defined wall and totally echo-free appearance characteristic of a simple cyst. Instead, the wall was shaggy and somewhat irregular with some evidence of septation. In the mixed type, the echographic appearance was compatible with pelvic inflammatory disease of an infectious etiology. In 3 cases with the solid pattern, the ultrasound appearance suggested ovarian malignancy. When the clinical setting and the age of the patient are suggestive of endometriosis, the sonographer should consider this possibility in his differential diagnosis of pelvic masses, regardless of the consistency of the lesion.