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Biomedical subjects

A Del Mistro

Publications and source records attributed to A Del Mistro.

At least 19 recordsLinked to original sources
PubMed2001

HPV-related neoplasias in HIV-infected individuals.

Human papillomavirus (HPV) infection of the lower genital tract is now considered the most important factor in the initiation of neoplasia. Human immunodeficiency virus (HIV) infection appears to alter the natural history of HPV-associated oncogenesis, but its impact on gynaecology has only recently been defined; the Centers for Disease Control (CDC) designated moderate and severe cervical dysplasia as a category B defining condition, and invasive cervical cancer as a category C defining condition of AIDS in 1993. Anal HPV infection and anal squamous intra-epithelial lesions have been found to be highly prevalent among HIV-positive homosexual men, and recent preliminary data suggest a relatively high prevalence among HIV-positive women as well. Moreover, HPV infection and associated lesions are also observed in body sites other than the anogenital area, particularly the skin and the oral cavity.

AIDS-Related Opportunistic Infections↗
PubMed2001

Genital human papillomavirus types in immunocompetent and immunodepressed women in northeast Italy: prevalence and cytomorphological correlations.

OBJECTIVE: We evaluated the prevalence of genital human papillomavirus (HPV) types in correlation with cytomorphological findings in patients at different risk for cervical intraepithelial neoplasia living in northeast Italy. METHODS: Exfoliated cervicovaginal cells from 943 women, who were divided into three groups, were analyzed by polymerase chain reaction. RESULTS: Overall, HPV prevalence rates were 7%, 38%, and 52%, respectively. The single most frequent type was HPV 16 (18%), followed by types 6, 31, 53, 58, 61, and novel/unidentified (5-7%); other types had a frequency <5%. Infection with multiple types was present in 12%. In HIV-infected women, HPV infection was correlated with lower CD4 level and higher viral load; HGSILs were correlated only with a lower CD4 count, and no correlations were found for LGSILs. CONCLUSIONS: HGSILs were associated with high-risk types, mainly HPV 16 (40%). LGSILs, instead, were associated with a broad spectrum of low-risk and high-risk types.

Journal Article↗
PubMed2000

Co-existence of cutaneous T-cell lymphoma and B hairy cell leukemia.

A primary cutaneous form of peripheral T-cell lymphoma (PTCL) and a low grade B-cell non-Hodgkin's lymphoma that was classified as a variant of hairy cell leukemia (HCL) were simultaneously diagnosed in a 79-year-old woman by both phenotypic and genotypic analyses. The coexistence of a T- and B-cell lymphoma in the same patient is rare, and, to our knowledge, this particular association has not been previously described. The patient was referred to our Department for evaluation of multiple cutaneous itchy, reddish plaques; laboratory analyses disclosed a lymphocytosis, that presented 6 years earlier. A bone marrow aspirate showed a 50% B-cell interstitial infiltrate, while a skin biopsy surprisingly revealed a PTCL. Clonality of both neoplastic processes was assessed by Southern blot analysis. The indolent clinical course of the cutaneous disease, and the low and stable number of circulating neoplastic T cells supported the diagnosis of a mycosis fungoides (MF)-like PTCL. Possible oncogenic events and/or putative underlying viral infections which could have played a role in the occurrence of B- and T-cell non-Hodgkin's lymphomas in the same patient are discussed.

Aged↗
PubMed2000

Vulvar carcinoma in a 12-year-old girl with vertically acquired human immunodeficiency virus infection.

We report the first case of a girl with vertically acquired human immunodeficiency virus (HIV) infection, who developed invasive squamous cell carcinoma of the vulva at 12 years of age. Lesions resembling bowenoid papulosis covered the perianal area as well. She underwent a nonmutilating surgical excision of the infiltrating lesion. More than 3 years later, her clinical condition is excellent, although dysplastic, noninfiltrating multifocal lesions persist. This case highlights the need to perform careful periodic genital examinations in all HIV-infected children and adolescents born to HIV-positive mothers.

CD4 Lymphocyte Count↗
PubMed2000

Colposcopy, cytology and HPV-DNA testing in HIV-positive and HIV-negative women.

In this study we examined the incidence of colposcopic-colpocytologic findings and analyzed Human Papilloma Virus (HPV)-DNA testing by Polymerase Chain Reaction (PCR) in 104 Human Immunodeficiency Virus (HIV) serous positive women (Group 1) and 218 HIV-negative women (control Groups 2 and 3). The aim of the study was to evaluate the most appropriate and efficacious diagnostic methods for screening programs for cervical cancer in HIV-positive women. For Group 1 we also considered the value of CD4+ T-lymphocytes and morphologic and molecular follow-up from 3 to 6 months. The results showed that the abnormal transformation zone (ANTZ) was present in 66.3% of the cases in Group 1 compared with 31.4% in control-Group 2 (p<0.001), and with 58.93% of the cases in control-Group 3 (p=0.257); intraepithelial squamous lesions (SIL) were found in 50% vs 5.66% (p<0.001) and vs 56.25% of the cases (p=0.433), respectively. In 28.85% of the HIV-positive patients the first cytological screening exam was not evaluable due to inflammation but in 56.67% of the cases colposcopy revealed ANTZ. The subsequent colpocytological checkup after therapy showed 10 cases (30%) of low risk squamous intraepithelial lesions (LSIL) and two cases (6.6%) of high risk squamous intraepithelial lesions (HSIL). HPV-DNA testing by PCR was positive in 53.8% of the cases in Group 1, in 6.6% in control-Group 2 and in 42% in control-Group 3. In HIV-positive patients multiple HPV genotypes were simultaneously present in 21.43% of the cases and high risk genotypes were present in 70% of the cases of HSIL. In Group 1, 36.61% of the cases had lesions of the lower genital tract. The value of CD4+ T-lympocytes was <200 cells/ml in 30% of the cases of HSIL. Our data, like those of other Authors, confirm a high incidence of HSIL, abnormal colposcopic findings, and HPV infections in HIV-positive women with respect to control-Group 2, while there was not much difference between Group 1 and control-Group 3. Such frequency again suggests that an integrated morphological diagnostic approach with colposcopy-colpocytology in the screening of immunosuppressed subjects would be worthwhile.

Adult↗
PubMed1997

Molecular profile of Epstein-Barr virus in human immunodeficiency virus type 1-related lymphadenopathies and lymphomas.

Human immunodeficiency virus type 1 (HIV-1)-infected patients develop a spectrum of lymphoproliferative disorders ranging from nonneoplastic lymphadenopathies to B-cell lymphomas. Although evidence suggests that Epstein-Barr virus (EBV) might be involved, its molecular profile and expression pattern in HIV-1-related lymphoproliferations remain to be defined. Using polymerase chain reaction-based techniques, we studied EBV types and variants in 28 lymphadenopathy lesions and in 20 lymphomas (15 large cell and 5 Burkitt-like). EBV was detected in 89% of lymphadenopathies and in 80% of lymphomas; viral DNA content was significantly higher in the latter. EBNA2 and LMP1 gene analysis indicated that half of the EBV+ lymphadenopathies were coinfected with both EBV type 1 and 2 strains and/or multiple type 1 variants. Conversely, all but one lymphoma carried a single viral variant, consistently type 1 in large cell lymphomas, and type 2 in Burkitt-like tumors. Most lymphomas, but no lymphadenopathies, showed monoclonal Ig heavy-chain rearrangement. Analysis of 5 large cell lymphomas and 9 lymphadenopathies for EBV transcripts identified LMP1 mRNA in most samples, and the EBNA2 transcript in all tumors. These findings provide evidence of a heterogeneous EBV population in lymphadenopathy lesions, strengthen the notion that lymphomas arise from clonal expansion of EBV+ cells, and suggest different roles for EBV types 1 and 2 in HIV-1-related lymphoproliferations.

AIDS-Related Opportunistic Infections↗
PubMed1997

Epstein-Barr virus-associated post-transplant lympho-proliferative disease of donor origin in liver transplant recipients.

BACKGROUND/AIMS: Post-transplant lymphoproliferative disease, a potential complication of solid organ transplantation, occurs in about 3% of orthotopic liver transplant recipients. We report the genetic and virological characterization of two cases of post-transplant lymphoproliferative disease that occurred early (4 and 6 months) after orthotopic liver transplant as large-cell non-Hodgkin's lymphomas located at the hepatic hilum. METHODS: Lymphomatous tissues were analyzed for clonality and presence of Epstein-Barr virus (EBV) sequences by Southern blot, polymerase chain reaction, and in situ hybridization techniques. RESULTS: The tumors in both cases were sustained by a clonal proliferation of B lymphocytes containing type A EBV DNA. Moreover, in situ hybridization with a digoxigenin-labeled EBV-specific probe evidenced a strong nuclear signal in most of the neoplastic cells. DNA microsatellite analysis at three different loci detected alleles of donor origin in both tumor samples, suggesting that the neoplastic B cells were of donor origin. CONCLUSIONS: EBV-infected donor B lymphocytes might be responsible for intragraft post-transplant lymphoproliferative disease in orthotopic liver transplant recipients. As 20 to 30% of post-transplant lymphomas involve the graft itself, donor-derived post-transplant lymphoproliferative disease might be more frequent than presently appreciated. Prospective studies are needed to assess its real incidence and identify possible risk factors.

B-Lymphocytes↗
PubMed1996

p53 gene alterations and protein accumulation in colorectal cancer.

Aim-To correlate immunohistochemical staining with single strand conformation polymorphism (SSCP) analysis of the p53 gene in colorectal cancer in order to understand how the findings provided by the two techniques complement each other in defining p53 functional status.Methods-Frozen tumour tissue from 94 patients with colorectal cancer was studied for p53 protein accumulation and gene mutations. Accumulation of p53 protein was detected by immunohistochemistry using PAb1801 and BP53-12-1 monoclonal antibodies. The findings were then compared with SSCP analysis of exons 5 to 8 of the p53 gene. All cases with a positive result by SSCP analysis were confirmed by sequencing.Results-Nuclear staining was observed in 51 (54.2%) cases. SSCP analysis of the DNA amplified by PCR revealed that the electrophoretic pattern had shifted in 30 cases; sequence analysis confirmed the occurrence of a mutation in 29 cases and of a polymorphism in one. In 27 cases both assays gave a positive result, and in 40 both were negative; therefore, concordance between PCR-SSCP and immunohistochemistry was seen in 72% of cases.Conclusion-The data indicate that positive immunostaining corresponds with the presence of a mutation in most, but not all, cases studied; other mechanisms could be responsible for stabilisation and accumulation of p53 protein in the nucleus. Nonsense mutations which do not confer stability on the protein will not be detected by immunohistochemistry and false negative results can also occur with SSCP analysis.

Journal Article↗
PubMed1996

B non-Hodgkin's lymphoma in a haemophilia patient with idiopathic CD4+ T-lymphocytopenia.

We report here a case of an HIV-uninfected, anti-hepatitis C virus (HCV) positive haemophiliac, who was transfused with blood and intermediate purity factor VIII concentrates. Since 1988, a progressive decline in the CD4+ T-cell count was recorded, and in 1993 a B-cell non-Hodgkin's lymphoma (B-NHL) was diagnosed. The morphological appearance of the tumor with features of intermediate/mantle zone lymphoma, and the absence of EBV sequences within the tumor, ruled out the occurrence of a typical "opportunistic" lymphoma. However it is possible that the blood product therapy and its infectious complications may have played a role on immune function impairment.

Adult↗
PubMed1995

HIV-1 infection of the thymus: evidence for a cytopathic and thymotropic viral variant in vivo.

As thymocyte infection may represent one of the mechanisms responsible for CD4+ T lymphocyte depletion in HIV-1-infected individuals, we studied the occurrence of HIV-1 infection in the thymus in vivo. Thymus (THYPD) and peripheral blood (PBLPD) primary viral isolates were obtained from an HIV-1-infected patient; restriction pattern analysis revealed the presence of a viral variant (THY) in the thymus isolate, from which biological viral clones containing this variant were obtained by limiting dilution infection of Molt-3 cells. The biological phenotype of the viral isolates and THY clones was studied in different cell lines and primary cultures. PBLPD, THYPD, and THY clones could efficiently infect T cell lines; the thymic variant showed a higher cytopathic activity in T cell lines, and a higher replication capacity in both unfractionated and CD4+CD8(+)-enriched primary thymocytes. Sequence analysis of the viral population patterns in vivo confirmed the presence of the THY variant in the thymic compartment, and revealed that the degree of V3 loop heterogeneity was higher in the thymocytes of the patient than in the peripheral blood lymphocytes. In addition to confirming thymocyte infection in vivo, our data also indicate that a differential distribution of viral variants may occur among different body compartments in a single individual; the emergence of cytopathic and tissue-specific variants in the thymus may play a relevant role in the pathogenesis of HIV-1 disease.

Acquired Immunodeficiency Syndrome↗
PubMed1995

Association of p53 gene and protein alterations with metastases in colorectal cancer.

Using monoclonal antibody PAb 1801, p53 protein was detected in the neoplastic cells of 39 (46.9%) of 83 colorectal carcinomas studied. Patients with p53+ tumors showed a higher incidence of lymph node and liver metastases (p = 0.035); in patients whose tumors were located in the rectosigmoid, p53 expression also correlated with a more advanced stage according to Dukes' classification (p = 0.015) as well as nodal (p = 0.006) and liver (p = 0.019) metastases. Following amplification of exons 5 to 8 of the p53 gene by means of the polymerase chain reaction technique, single-strand conformation polymorphism analysis disclosed an anomalous migration pattern in 23 of the 39 p53+ tumors and in four of the 35 p53- tumors analyzed. Sequence analysis showed G:C-->A:T transitions in 63.6%, G:C-->T:A and G:C-->C:G transversions in 18.2%, deletions and insertions in 13.6%, and A:T-->G:C transitions in 4.6% of the cases. Loss of heterozygosity was studied in the DNA of 79 patients; allelic loss was found in 29 (49.1%) of the 59 informative patients. Loss of heterozygosity was correlated with p53 overexpression (p = 0.0002) as well as with the presence of mutations as detected by single strand conformation polymorphism analysis (p = 0.0024).

Adenocarcinoma↗
PubMed1994

Epidemiology and etiopathology of human T-lymphotropic viruses: diagnostic and clinical implications for non-endemic areas.

Human T-lymphotropic viruses (HTLV) type I and II were first described more than a decade ago. HTLV-I epidemiology and etiopathology are more defined than those of HTLV-II, but conflicting results have been obtained in seroepidemiologic surveys, mainly for difficulties in the discrimination between the two infections. The introduction of advanced serologic and molecular assays has recently provided sensitive and specific tools for diagnosis, and the epidemiologic and etiopathologic patterns linked to these retroviruses are being more precisely defined. Moreover, extensive nucleotide sequence analyses performed so far have mainly focused on HTLV-I isolates. The recent discovery of new HTLV-II endemic areas and the isolation of HTLV-II strains from intravenous drug users have finally provided the material for the molecular characterization of HTLV-II isolates, which is now a rapidly envolving field. We review the diagnostic strategies available and the etiologic associations reported so far for both viruses and also discuss the occurrence and significance of indeterminate serologic reactivities observed in both endemic and non-endemic areas.

Deltaretrovirus Infections↗
PubMed1994

HTLV-I and HTLV-II infections among HIV-1 seropositive patients in Sao Paulo, Brazil.

To estimate the presence of, and the risk factors for HTLV-I and HTLV-II infections among HIV-1 infected subjects in Sao Paulo, Brazil, a serosurvey was performed in 471 HIV-1 infected patients, including 216 intravenous drug addicts (IVDA), 229 homosexual/bisexual men, and 26 with other risk factors. Serum samples were screened for HTLV seroreactivity by ELISA; reactive samples were analyzed by Western Blot (WB), using whole HTLV-I lysate as antigen. To confirm and discriminate HTLV-I and HTLV-II infections, sera presenting any bands on WB were further analyzed by a WB containing recombinant HTLV-I and HTLV-II proteins (WB 2.3), and by enzyme immunoassays using synthetic peptides specific for envelope proteins (Synth-EIA). In 22 cases, cell samples were available for polymerase chain reaction (PCR) studies. On WB, 114 sera were reactive and, of these, 37 and 25 were concordantly positive on both WB 2.3 and Synth-EIA procedures for HTLV-I and HTLV-II specific antibodies, respectively; 37 specimens were negative on both assays, and 15 gave discordant or indeterminate results. PCR findings confirmed concordant results obtained in the discriminatory serological assays. The prevalence rates of HTLV-I and HTLV-II infections were 15.3% and 11.1% in IVDA, and 0.9% and 0.4% in homosexual/bisexual men, respectively. No case of HTLV-I/HTLV-II co-infection was found.

Adolescent↗
PubMed1994

B and T cell function parameters during zidovudine treatment of human immunodeficiency virus-infected patients.

The aim of this study was to assess the effects of zidovudine on B cell dysregulation in human immunodeficiency virus (HIV)-infected patients and the phenomenon of gp 120/anti-gp 120 antibody complex adhesion to CD4+ cells. Compared with pretherapy figures, zidovudine treatment was not associated with a change in spontaneous in vitro synthesis of anti-HIV antibodies but was related to restoration of lymphocyte ability to produce Epstein-Barr virus-specific antibodies in 43% of previously unresponsive patients. After 30 days of therapy, the percentage of circulating CD4+/IgG+ lymphocytes decreased; the number of available CD4 receptors per cell increased, and antibodies to gp 120, evident in CD4+ cell eluates from most untreated patients, were no longer detectable. These results indicate that zidovudine partly restores in vitro humoral responsiveness but does not substantially influence the overall activation of the B cell compartment. The findings also suggest that zidovudine may down-regulate some immunopathologic phenomena that amplify direct viral damage.

Antigen-Antibody Complex↗