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Biomedical subjects

E Roggero

Publications and source records attributed to E Roggero.

At least 19 recordsLinked to original sources
PubMed2002

Differential susceptibility to acute Trypanosoma cruzi infection in BALB/c and C57BL/6 mice is not associated with a distinct parasite load but cytokine abnormalities.

Inoculation of Trypanosoma cruzi, Tulahuén strain, into C57BL/6 and BALB/c mice led to an acute infection characterized by marked parasitaemia, myocardial inflammation and thymocyte depletion. While C57BL/6 mice showed a progressive and lethal disease, BALB/c mice partly recovered. To characterize these murine models more effectively, we studied the parasite burden, serum levels of major infection outcome-related cytokines, the in vitro features of T. cruzi infection in peritoneal macrophages and the immunophenotype of thymic cells. The greater disease severity of T. cruzi-infected C57BL/6 mice was not linked to an increased parasite load, as parasitaemia, myocardial parasite nests and amastigote counts in peritoneal macrophages were not different from those in BALB/c mice. Cortical thymocyte loss was accompanied by the presence of apoptotic bodies and fragmented nuclear DNA, whereas fluorocytometric analysis at 17 days postinfection (p.i.) revealed a more pronounced loss of CD4+ CD8+ cells in C57BL/6 mice. This group displayed higher levels of TNF-alpha on days 14 and 21 p.i., in the presence of lower IL-1beta and IL-10 concentrations by days 14 and 21, and days 7 and 14 p.i., respectively. Day-21 evaluation showed higher concentrations of nitrate and TNF-alpha soluble receptors in C57BL/6 mice with no differences in IFN-gamma levels, with respect to the BALB/c group. Increased morbidity of C57BL/6 T. cruzi-infected mice does not seem to result from an aggravated infection but from an unbalanced relationship between pro- and anti-inflammatory mediators.

Acute Disease↗
PubMed2001

Nodal marginal zone B-cell lymphomas may arise from different subsets of marginal zone B lymphocytes.

Nodal marginal zone B-cell lymphoma (MZL) is a rare and not extensively studied entity that accounts for approximately 2% of all non-Hodgkin lymphomas. Complementarity-determining regions 2 and 3 (CDR2, CDR3) of the immunoglobulin heavy-chain variable region (V(H)) genes were amplified by polymerase chain reaction (PCR), cloned, and sequenced in 8 patients with nodal MZL. All showed a potentially functional V(H) rearrangement. The use of V(H) gene families was unbiased and without overrepresentation of any particular V(H) gene or gene family. The presence of somatic V(H) mutations was detected, with a deviation from the closest germ line sequence ranging from 4% to 17% in 6 of 8 patients. In 3 mutations, the replacement-to-silent mutation ratio suggested the presence of an antigen-selected process. Sequencing different subclones of the same cloned PCR products allowed the detection of intraclonal variability in 4 analyzed patients. The observed pattern of V(H) mutations suggested that nodal MZL, formerly deemed a malignancy of memory B cells, may arise from different subsets of marginal zone B cells-the naive B cells that express unmutated V(H) genes-from memory B cells showing somatic mutations without intraclonal variation, and from germinal center B cells defined by their capacity to undergo the somatic hypermutation process. (Blood. 2001;98:781-786)

Adult↗
PubMed2001

Treatment with benznidazole and its immunomodulating effects on Trypanosoma cruzi-infected rats.

Because benznidazole (BZL) was found to downregulate nitric oxide (NO) and cytokine synthesis by murine macrophages, we analyzed the potential immunological repercussions of BZL treatment in Trypanosoma cruzi-infected rats. To evaluate whether the effects of BZL were also observed in the presence of an immunostimulating cytokine, four groups of acutely infected rats were subjected to one of the following 20-day therapeutic schedules: (1) a curative BZL oral regimen, (2) recombinant interferon (IFN-gamma) injections, (3) a suboptimal BZL regimen (25% of curative dose), (4) the latter plus IFN-gamma. All BZL doses markedly reduced NO-derived metabolites either in the circulation or in cultured macrophage supernatants. This was observed in rats simultaneously treated with IFN-gamma, which contrasted with the augmented NO production seen in animals given this cytokine alone. The untreated rats, and groups receiving monotherapy with IFN-gamma or 25% BZL, had increased circulating interleukin (IL)-1beta and IL-2 levels, which were reduced in those given BZL plus IFN-gamma. Although combined treatment failed to cause the virtually undetectable blood parasite levels induced by optimal BZL doses, chronic myocardial lesions were reduced to the same extent as in those receiving the curative schedule. The beneficial effects of BZL in this trypanosomiasis may also depend on some immunomodulating influences.

Adjuvants, Immunologic↗
PubMed2001

Comprehensive analysis of 112 melanocytic skin lesions demonstrates microsatellite instability in melanomas and dysplastic nevi, but not in benign nevi.

INTRODUCTION: the length of DNA repetitive sequences (microsatellite instability (MSI)) represent distinct tumorigenic pathways associated with several familial and sporadic tumors. MATERIAL AND METHODS: To investigate the prevalence and frequency of MSI in melanocytic lesions, the polymerase chain reaction (PCR)-based microsatellite assay was used to examine formalin-fixed, paraffin-embedded tissues of 30 benign melanocytic nevi, 60 melanocytic dysplastic nevi (MDN), and 22 primary vertical growth phase cutaneous malignant melanomas (CMM). Twenty-four microsatellite markers at the 1p, 2p, 3p, 4q and 9p chromosomal regions were used. RESULTS: MSI was found at 1p and 9p in MDN and CMM but not in benign melanocytic nevi. The overall prevalence of MSI was 17/60 (28%) in MDN and 7/22 (31%) in CMM. The frequency of MSI ranged from 2/24 (9%) to 4/24 (17%) and was most commonly found at D9S162. There was a statistically significant correlation between degree of atypia and frequency of MSI (p<0.001) in MDN. There were two MSI banding patterns: band shifts and additional bands. CONCLUSIONS: The data presented revealed the presence of low-frequency MSI (MSI-L) at the 1p and 9p regions in both MDN and CMM. Whether the MSI-L pattern reflects a defect in mismatch repair genes is still to be determined.

Chromosome Mapping↗
PubMed2001

Alterations of mismatch repair protein expression in benign melanocytic nevi, melanocytic dysplastic nevi, and cutaneous malignant melanomas.

Immunoperoxidase-staining methods were used to examine the expression of hMLH1, hMSH2, and hMSH6 mismatch repair (MMR) proteins in 50 melanocytic lesions. Microsatellite instability (MSI), screened previously in these lesions by polymerase chain reaction-based microsatellite assay, showed low-level microsatellite instability (MSI-L) in 11 of 22 melanocytic dysplastic nevi (MDN) and two of nine primary cutaneous malignant melanomas (CMMs) but not in the benign melanocytic nevi (BN). Mismatch repair proteins were widely expressed in the epidermis and adnexal structures. All lesions showed positive immunoreactivity with a gradual decrease in the MMR staining values during the progression from BN to MDN to CMMs. The average percentage of positively (PP) stained cells for hMLH1, hMSH2, and hMSH6 in BN was 85.50 +/- 1.95, 77.90 +/- 4.50, and 87.11 +/- 1.85, respectively. The PP cell values in CMMs were significantly reduced as compared with BN (75.22 +/- 3.57, p= 0.01; 56.11 +/- 8.73, p= 0.02; 65.22 +/- 6.47, p = 0.0002 for hMLH1, hMSH2, and hMSH6, respectively). No comparable significant difference was found between microsatellite stable and MSI-L lesions (p = 0.173, p = 0.458, and p = 0.385), suggesting a lack of correlation between MMR expression and MMR function. There was a direct correlation between PP cell values of hMSH2 and hMSH6 (R = 0.39, p = 0.008), implying that their expression could be regulated by a common mechanism. Thus, an important finding of these studies was the reduction of MMR protein levels in CMMs; whether this reflects underlying genetic or epigenetic mechanisms is still to be determined.

Adaptor Proteins, Signal Transducing↗
PubMed2000

Association of gastric and Waldeyer's ring lymphoma: a molecular study.

The coexistence of Waldeyer's ring and gastrointestinal non-Hodgkin's lymphomas at presentation is well known. Moreover, localized gastrointestinal relapses following successful treatment of lymphomas of Waldeyer's ring and thyroid lymphomas occurring after a prolonged disease-free interval have also been described. We report two cases of concomitant lymphoma in Waldeyer's ring and stomach. On the basis of the molecular analysis of the immunoglobulin heavy chain gene rearrangements, two different patterns of concomitant involvement by a lymphoma in Waldeyer's ring and in the gastrointestinal region seem to exist. One is represented by the preferential dissemination of the lymphoma from one site to the other, the second by the apparently independent growth of clonally unrelated lymphomas at each site.

Complementarity Determining Regions↗
PubMed2000

Prognostic models for diffuse large B-cell lymphoma.

Prognosis of DLCL patients is variable and associated with well-defined risk factors. In the past decade several pretreatment variables have been incorporated into prognostic models to predict the death risk of individual patients. The International Prognostic Index (IPI), developed in an international consensus study, has been one of the most widely accepted of these models. In our study we applied some of the major prognostic models proposed for DLCLs in a cohort of 111 patients uniformly treated with a CHOP-like regimen in order to compare their sensitivity and specificity. We also evaluated the possibility of improving the IPI with the inclusion, from among the variables analysed, of serum beta-2 microglobulin level (beta-2M). The sensitivity, reflecting the ability to predict all failures in the cohort of patients as a whole, has improved from 45 to 73 per cent when the beta-2M-IPI model is compared with IPI, without a significant loss of specificity. Based on these results, the beta-2M-IPI may be useful for identifying the subset of patients with very poor prognoses. Therefore, the use of the serum beta-2M value in addition to the IPI may help in selection of the patients with DLCL at higher risk for treatment failure, and identification of those who may require specifically tailored therapeutic approaches.

Adult↗
PubMed2000

Eradication of Borrelia burgdorferi infection in primary marginal zone B-cell lymphoma of the skin.

Primary cutaneous B-cell lymphomas have been associated with Borrelia burgdorferi, the spirochete responsible for Lyme disease. Recently, cutaneous marginal zone B-cell lymphoma has been proposed as a distinct clinical-pathological entity. We report a case of primary cutaneous marginal zone lymphoma, associated with B burgdorferi infection. Polymerase chain reaction (PCR) amplification of the third complementarity determining region (CDR3) of the immunoglobulin heavy chain gene showed the presence of a monoclonal lymphoproliferation, therefore strengthening the histological diagnosis of a malignant process. B burgdorfer-specific hbb gene sequences were detected by PCR in the lymphoma tissue at diagnosis but not after antibiotic treatment. A nearly complete clinical and histological regression was observed after B burgdorferi eradication, with immunohistochemistry studies showing disappearance of plasma cell differentiation and a marked decline in the number of CD3+ T cells and Ki-67+ cells. Our case confirms the link between B burgdorferi and some cutaneous lymphomas. The disappearance of the microorganism accompanied by the unequivocal decrease of most indicators of active T- and B-cell immune response strongly supported a pathogenetic role for B burgdorferi in sustaining an antigen-driven development and growth of this cutaneous marginal zone lymphoma. Antibiotic therapy (analogous to Helicobacter pylori infection in gastric MALT lymphoma) might be helpful with the aim of averting or at least deferring the indication for more aggressive treatment.

Aged↗
PubMed2000

Molecular detection of circulating neoplastic cells in patients with clinically localised gastric and non-gastric mucosa-associated lymphoid tissue lymphoma.

BACKGROUND: Unlike other low-grade lymphomas, extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue type usually presents with localised disease. AIM: To detect peripheral blood lymphoma involvement to establish the incidence of occult lymphoma dissemination. PATIENTS AND METHODS: In a series of 18 cases, peripheral blood was analysed by polymerase chain reaction, with primers directed to the third-complementarity determining region of the immunoglobulin heavy chain gene. RESULTS AND CONCLUSION: The presence of circulating neoplastic cells was detected in 21% of clinically localised cases. Moreover lymphoma cells were detected in 2 out of 6 morphologically normal bone marrow specimens. The present data show that, combining morphological and molecular methods, occult dissemination can be found in a large proportion of cases thus stressing the need for careful staging procedures. However, it has still to be clarified whether the presence of polymerase chain reaction-detectable circulating lymphoma cells can influence the outcome of mucosa-associated lymphoid tissue lymphoma patients submitted to antibiotic treatment (for gastric localisation) or local therapy (surgery or radiation, for non-gastric tumours).

Adult↗
PubMed2000

Lack of CD95/FAS gene somatic mutations in extranodal, nodal and splenic marginal zone B cell lymphomas.

Germline CD95 (also known as FAS, APT1 and APO1) gene mutations have been associated with benign lymphoproliferative diseases and autoimmune processes. Somatic mutations have been reported in human tumours, including lymphomas. Since marginal zone B cell lymphomas usually arise in a background of chronic inflammation, often of autoimmune origin, we searched for CD95 gene mutations in an unselected series of marginal zone B cell lymphomas. The CD95/FAS full coding region, comprising exon-intron junctions, was amplified from genomic DNA by polymerase chain reaction (PCR) in 10 separate reactions. PCR products were analysed by single-strand conformation polymorphism (SSCP) and visualised by silver staining. Bands exhibiting an altered electrophoretic mobility were sequenced. Twenty-seven cases of marginal zone B cell lymphomas of whom fresh or frozen tumour material was available (18 extranodal, five splenic and four nodal) were studied. Previously described silent polymorphisms in exons 7 (C836T) and 3 (T416C) were detected in 42% and in 19% of the cases, respectively. One silent T-to-A substitution at bp 431, within exon 3, was found in one case. Our results did not reveal the presence of CD95 somatic mutations in unselected cases of marginal zone B cell lymphomas. On the basis of our data, we cannot rule out that other genes coding for proteins involved in the CD95-induced apoptotic pathway might be altered. However, this pathway does not seem to play an important role in the pathogenesis of these lymphoma subtypes.

Antigens, Neoplasm↗
PubMed2000

Extranodal marginal zone B-cell lymphoma genotyping by Alu-polymerase chain reaction.

DNA amplification by polymerase chain reaction (PCR) with primers designed on the widely distributed Alu sequences allows the production of specific inter-Alu DNA-fingerprints. Amplification of tumour and matched normal DNA can show differences due to genetic alterations within the tumour genome. We applied this approach to study low-grade extranodal marginal zone B-cell lymphoma (of MALT type). After digestion with restriction enzymes, DNA samples were separately amplified by PCR with three different Alu-primers. A comparison between the fingerprint pattern from lymphoma and normal samples was made. Inter-Alu bands differing between the two samples were excised from the gel, cloned and sequenced. Nine cases of low-grade MALT-lymphomas have been analysed, giving seventeen different bands between tumour and normal. DNA sequence analysis showed identities for three of them with sequences available at the GenBank. The methodology of Alu-PCR to detect DNA-based abnormalities, in addition or combination with RNA-based methods, is a powerful tool to identify candidate regions frequently altered in tumours. With the increased available genomic sequences through the Human Genome Project, there will be an increasing probability of picking up perfect homologies with these sequences using cloned differential Alu-PCR bands in BLAST searches through genome databases.

Alu Elements↗
PubMed2000

Prevalence of Helicobacter pylori and hepatitis C virus infections among non-Hodgkin's lymphoma patients in Southern Switzerland.

BACKGROUND AND OBJECTIVE: Several recent studies have reported a high rate of previous hepatitis C virus (HCV) infection in patients with non-Hodgkin's lymphoma (NHL). However, it appears that there are marked geographical differences in the prevalence of HCV among NHL patients. There is further controversy concerning a possible pathogenetic link between HCV and certain histologic lymphoma subtypes, in particular MALT lymphomas, and it has recently been speculated that HCV might be involved in the multistep process of gastric lymphoma genesis, in addition to the well established role of chronic Helicobacter pylori infection. The aim of this study was to investigate the prevalence of HCV and H. pylori infections in patients with B-cell NHL in Southern Switzerland. DESIGN AND METHODS: One hundred and eighty newly diagnosed HIV-negative B-cell NHL patients, consecutively seen at a referral oncology center in Southern Switzerland between 1990 and 1995 were prospectively studied. A microparticle enzyme immunoassay was used to detect antibodies to HCV. Serologic determination of HCV genotype was done by the Murex method. The quantitative detection of IgG anti-H. pylori was performed by the Biorad GAP test. RESULTS: Infection with HCV was detected in 17/180 patients (9.4%; 95% C.I., 6%-15%). This prevalence is significantly higher than that observed in a large survey of 5424 new blood donors from the same area tested in 1992-97 (0.9%; 95% C.I., 0.7-1.2). Neither histologic subtypes nor specific extranodal presentations of NHL were associated with a higher prevalence of HCV. HCV serotype 2 (corresponding to genotypes 2a-c) was the most common. HCV infection was significantly associated with a shorter progression-free survival at both univariate and multivariate analysis. Anti-Helicobacter antibodies were detected in 81/180 patients (45%; 95% C.I., 38%-53%) and H. pylori infection was significantly associated with the development of primary lymphomas of the stomach. INTERPRETATION AND CONCLUSIONS: A high prevalence of HCV infection was detected in NHL lymphoma patients and was associated with a shorter time to lymphoma progression. HCV infection was not correlated with primary gastric presentation or with MALT-type histology. Our findings further support the key role of H.pylori infection in the pathogenesis of primary gastric lymphoma of MALT-type. The possible role of HCV in the pathogenesis of NHL should be further investigated.

Aged↗
PubMed1999

Microsatellite instability in gastric MALT lymphomas and other associated neoplasms.

BACKGROUND: Microsatellite instability (MSI), caused by a reduced efficacy of the DNA mismatch repair (MMR) machinery, represents a type of genomic instability frequently detected in HNPCC spectrum cancers and in a subset of sporadic carcinomas. The involvement of MSI in the pathogenesis of gastric lymphoma of mucosa-associated lymphoid tissue (MALT) has never been conclusively investigated. In this study, we tested the presence of MSI in tumor samples of patients harboring both MALT lymphomas and other types of malignancies. MATERIALS AND METHODS: We examined 10 microsatellite loci (D3S11, D3S1261, D3S1265, D6S262, D6S193, BAT-26, BAT-25, D17S250, APC, D2S123) out of a total of 34 primary tumors from 14 patients with MALT lymphomas and one or more additional neoplasms. The patients' MSI results were also tested for an association with a positive family history of cancer. RESULTS: MSI, defined by the presence of microsatellite alterations in more than 40% of the examined loci, was scored negative in all tumors studied, and pedigree analysis failed to identify any condition of familial cancer among the patients examined. CONCLUSIONS: The present study suggests that defects in DNA mismatch repair do not contribute significantly to the molecular pathogenesis of MALT lymphomas and associated neoplasms.

Colorectal Neoplasms, Hereditary Nonpolyposis↗
PubMed1999

Primary mediastinal large B-cell lymphoma: the need for prospective controlled clinical trials.

Primary mediastinal large-B cell lymphomas (PMLCL) are considered to be a distinct clinicopathologic entity among the diffuse large B-cell lymphomas. This study evaluated the prognostic factors and therapeutic outcome of PMLCL in a single-institution series. Twenty seven patients were reviewed. Nineteen of the 27 had Stage I-II and 8 had Stage III-IV disease. B-symptoms were found in 11 (41%) and bulky disease in 10 (37%) patients. All were initially given combination chemotherapy (CT): doxorubicin-containing regimens to 23 patients (11 patients had CHOP, 12 received more intensive third-generation regimens) and 4 elderly (>70 years) patients received CVP. Eleven responders were consolidated with irradiation (RT) as part of their initial treatment, with a median total dose of 39 Gy. Nineteen patients (70%) achieved clinical remission (15 CR and 4 PR) with their initial therapy. Forty-four percent of patients remained progression-free and 59% are alive at 3 years. The actuarial 10-year time to progression (TTP) and overall survival (OS) were 44% and 50%, respectively. Age >60 years, performance status >1 and IPI intermediate-high to high risk were significantly associated with poorer OS and TTP by univariate analysis (log-rank test). A better outcome was associated with the use of more aggressive chemotherapy regimens or with the inclusion of RT in the first-line treatment. Our analyses suggest that the application of radiotherapy in combination regimens and the use of more aggressive chemotherapy in the treatment of this particular type of lymphoma should now be evaluated in prospective randomized trials.

Actuarial Analysis↗
PubMed1999

Primary mediastinal large B-cell lymphoma (PMLCL): the need for prospective controlled clinical trials.

Primary mediastinal large-B cell lymphomas (PMLCL) are considered to be a distinct clinicopathologic entity among the diffuse large B-cell lymphomas. This study evaluated the prognostic factors and therapeutic outcome of PMLCL in a single-institution series. Twenty seven patients were reviewed. Nineteen of the 27 had Stage I-II and 8 had Stage III-IV disease. B-symptoms were found in 11 (41%) patients and bulky disease in 10 (37%). All patients were initially given combination chemotherapy (CT): doxorubicin-containing regimens to 23 patients (11 patients had CHOP, 12 more intensive third-generation regimens) and 4 elderly (>70 years) patients received CVP. Eleven responders were consolidated with irradiation (RT) as part of their initial treatment, with a median total dose of 39 Gy. Nineteen patients (70%) achieved clinical remission (15 CR and 4 PR) with their initial therapy. Forty-four percent of patients remained progression-free and 59% are alive at 3 years. The actuarial 10-year TTP and OS were 44% and 50%, respectively. Age >60 years, performance status >1 and IPI intermediate-high to high risk were significantly associated with poorer OS and TTP by univariate analysis (log-rank test). A better outcome was associated with the use of more aggressive chemotherapy regimens or with the inclusion of RT in the first-line treatment. In conclusion our analyses suggest that the application of radiotherapy in combination regimens and the use of more aggressive chemotherapy in the treatment of this particular lymphoma entity should be evaluated in prospective randomized trials.

Adult↗