Dendritic reticulum cell-related immunostaining for laminin in follicular and diffuse B-cell lymphomas

Summary We performed a comparative immunohisto-cytochemical study of the distribution patterns of laminin and follicular dendritic reticulum cells (DRCs) within their follicular microenvironment in both nodular or diffuse B-cell non Hodgkin's lymphomas (NHLs). Twenty nine cases of immunophenotypically diagnosed B-cell NHLs (19 of follicular center cell origin-FCCL- and 10 of the diffuse well differentiated lymphocytic type-WDLL-) and five reactive lymph nodes with follicular hyperplasia were analyzed by immunoperoxidase and immunofluorescence techniques. Serial frozen sections and cytospin preparations were tested either with single antibodies anti laminin and DRC-1, or paired reagents in double labeling immunofluorescence. Our results indicated consistently that within both the reactive germinal centers and the neoplastic nodules of FCCL laminin immunostaining visualized a punctate-granular pattern apart from the linear vascular basement membrane positivity. Double immunofluorescence assay demonstrated that there was a close parallelism between this laminin staining pattern and DRC-1 distribution showing a well developed DRCs meshwork; in the diffuse tumour areas of both FCCL and WDLL, laminin immunoreactivity was found only in those cases in which nests of DRCs were observed. Double immunofluorescence studies performed on cytospin preparations demonstrated that the groups of cells containing DRC-1 positive cells, contained a positivity for laminin, although within the cell the staining for DRC-1 was intense and diffuse, while that for laminin was granular and more sparse. Our results suggested that these laminin and DRC-1 positive reactive sites may be present on the same cells. Since the reduction in number or loss of both DRCs and their related immunostaining for laminin within the microenvironment was consistently associated with a loss of nodularity by lymphoma cells, whereas nodularity in reactive and neoplastic conditions was associated with a rich DRCs meshwork and the related laminin immunostaining, a trapping function of DRCs exercised in the presence of laminin should be considered.This work was supported in part by a Grant N 87.02799.44 from the Consiglio Nazionale delle Ricerche, Progetto Finalizzato Oncologia, Rome, and by the Associazione Italiana per la Ricerca sul Cancro, Milan, Italy     

Heterogeneous pattern of chromosomal breakpoints involving the MYC locus in multiple myeloma

Chromosomal rearrangements of the MYC locus, which often involve the IG loci, are recurrent events in multiple myeloma (MM) and plasma cell leukemia (PCL). We used dual-color fluorescence in situ hybridization (FISH) to characterize the breakpoint locations of chromosomal translocations/rearrangements involving the MYC locus at 8q24 found in a panel of 14 MM cell lines and 70 primary tumors (66 MM and 4 PCL). MYC locus alterations were observed in 21 cases: MYC/IG (mainly IGH@) fusions in 11 cell lines and three patients (2 MM and 1 PCL), and extra signals and/or abnormal MYC localizations in seven patients (5 MM and 2 PCL). Fourteen of these cases were investigated by FISH analyses by use of a panel of BAC clones covering about 6 Mb encompassing the MYC locus. The breakpoints were localized in a region 100-250 kb centromeric to MYC in four cases, a region 500-800 kb telomeric to the gene in four cases, and regions > or = 2 Mb centromeric or telomeric to MYC in five cases. Two different breakpoints were detected in the KMS-18 cell line, whereas the insertion of a MYC allele was found in a complex t(16;22) chromosomal translocation in the RPMI8226 cell line. Our data document a relatively high dispersion of 8q24 breakpoints in MM.     

Chernobyl accident: dosimetric evaluation and estimation of risks

The results of dosimetric evaluations carried out after Chernobyl accident in the Health Physics Department of Niguarda Ca' Granda Hospital (Milan) on air, rain and ground contamination are presented. The results obtained show that the incidence of stochastic late effects, both somatic and genetic, will be so low that practically will not be distinguishable from "natural" incidence.     

Free Fatty Acids Signature in Human Intestinal Disorders: Significant Association between Butyric Acid and Celiac Disease

Altered circulating levels of free fatty acids (FFAs), namely short chain fatty acids (SCFAs), medium chain fatty acids (MCFAs), and long chain fatty acids (LCFAs), are associated with metabolic, gastrointestinal, and malignant diseases. Hence, we compared the serum FFA profile of patients with celiac disease (CD), adenomatous polyposis (AP), and colorectal cancer (CRC) to healthy controls (HC). We enrolled 44 patients (19 CRC, 9 AP, 16 CD) and 16 HC. We performed a quantitative FFA evaluation with the gas chromatography–mass spectrometry method (GC–MS), and we performed Dirichlet-multinomial regression in order to highlight disease-specific FFA signature. HC showed a different composition of FFAs than CRC, AP, and CD patients. Furthermore, the partial least squares discriminant analysis (PLS-DA) confirmed perfect overlap between the CRC and AP patients and separation of HC from the diseased groups. The Dirichlet-multinomial regression identified only strong positive association between CD and butyric acid. Moreover, CD patients showed significant interactions with age, BMI, and gender. In addition, among patients with the same age and BMI, being male compared to being female implies a decrease of the CD effect on the (log) prevalence of butyric acid in FFA composition. Our data support GC–MS as a suitable method for the concurrent analysis of circulating SCFAs, MCFAs, and LCFAs in different gastrointestinal diseases. Furthermore, and notably, we suggest for the first time that butyric acid could represent a potential biomarker for CD screening.     

Clonal composition and persistence of antigen-specific circulating T follicular helper cells

T follicular helper (T_FH) cells play an essential role in promoting B cell responses and antibody affinity maturation in germinal centers (GC). A subset of memory CD4⁺ T cells expressing the chemokine receptor CXCR5 has been described in human blood as phenotypically and clonally related to GC T_FH cells. However, the antigen specificity and relationship of these circulating T_FH (cT_FH) cells with other memory CD4⁺ T cells remain poorly defined. Combining antigenic stimulation and T cell receptor (TCR) Vβ sequencing, we found T cells specific to tetanus toxoid (TT), influenza vaccine (Flu), or Candida albicans (C.alb) in both cT_FH and non-cT_FH subsets, although with different frequencies and effector functions. Interestingly, cT_FH and non-cT_FH cells specific for C.alb or TT had a largely overlapping TCR Vβ repertoire while the repertoire of Flu-specific cT_FH and non-cT_FH cells was distinct. Furthermore, Flu-specific but not C.alb-specific PD-1⁺ cT_FH cells had a “GC T_FH-like” phenotype, with overexpression of IL21, CXCL13, and BCL6. Longitudinal analysis of serial blood donations showed that Flu-specific cT_FH and non-cT_FH cells persisted as stable repertoires for years. Collectively, our study provides insights on the relationship of cT_FH with non-cT_FH cells and on the heterogeneity and persistence of antigen-specific human cT_FH cells.     

In-vivo experimental demonstration that hyperhistaminism counteracts tumor-growth

Induction of hyperhistaminism in peritoneum of rats by daily intraperitoneal supply of 0.005 mu g of histamine, counteracts the growth of 10(3) Yoshida ascite sarcoma cells only if administration precedes inoculation of tumor cells and has a long duration. Treating animals for two weeks before tumor cell inoculation we observed significant 70% survival, that was increased to 80% continuing the supply for 20-days after the inoculation; treatment for 3 days before or 20 days after the inoculation did not show significant results. The condition created in rat peritoneum is similar to that in allergic people, and our data in animals confirm statistical data observed in allergic people showing decreased incidence of neoplastic disease due to histamine, that appears to be integrated in a highly potent immunoregulatory circuit.     

Cryopreserved,cultured, allogenic,human epidermal grafts for the treatment of chronic ischemic ulcers: A report on two cases

Cultured, allogenic, human epidermal grafts have been successfully used to treat extensive burns, donor sites, leg ulcers, and eroded areas in recessive dystrophic epidermolysis bullosa. The following report describes the use of cryopreserved cultured human epidermal allografts in the treatment of long-standing ischemic ulcers unresponsive to conventional medical therapy in two patients who had previously undergone unsuccessful vascular reconstructive surgery. A marked reduction in ulcer size as well as rapid pain relief was achieved in both patients. In selected cases the use of epidermal grafts as a biologic topical therapy could represent an alternative to other medical treatments. However, thus far, only a few cases have been reported and the uncertain short- and long-term results as well as the excessive costs may limit the widespread application of this treatment modality.     

Estimating the human immunodeficiency virus infection curve of intravenous drug users in Lombardia,Italy

We present a model to estimate the infection curve of the human immunodeficiency virus in intravenous drug users in Lombardia. We based estimates on AIDS incidence data, according to a backcalculation model accounting for therapy and changes in the surveillance definition of AIDS.