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Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Monocyte/macrophage-mediated tumor cytotoxicity was studied in patients infected with human immunodeficiency virus-1 (HIV-1) at various stages [Center for disease control (CDC) classification] of the disease. using the P-815 tumor cell line as target cells, the results demonstrated reduced monocyte/macrophage cytotoxicity early in HIV-1-related disease (CDCIII, P < 0.01). This cellular dysfunction sustained during the progression of the disease. Evidence could be presented that neither exogenous application of macrophage-stimulating cytokines (e.g. interferons) nor their endogenous induction in vitro restored monocyte/macrophage cytotoxicity. However, enhanced tumor necrosis factor (TNF)-alpha production, which parallels the observed reduced capacity to lyse P-815 tumor cells, might be the major source for monocyte/macrophage-mediated cell lysis. TNF-alpha-induced cytotoxicity can be inhibited by addition of anti-TNF-alpha. Other experimental models using TNF-sensitive tumor target cells may, therefore, mimic monocyte/macrophage-mediated lysis. Suppression of monocyte/macrophage cytotoxicity in later stages of HIV-1 infection (AIDS-related complex, AIDS) could partly be reverted by treatment with the cyclooxygenase blocker, indomethacin. The responsible arachidonic acid product mediating suppression was found to be prostaglandin E2, suggesting that in addition to the direct viral interference cellular dysfunction is at least in part a result of altered cytokine regulation.
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PMID:Cytokine-mediated regulation of monocyte/macrophage cytotoxicity in human immunodeficiency virus-1 infection. 128 2

In a series of 33 cynomolgus monkeys (Macaca fascicularis) experimentally infected with Simian Immunodeficiency virus (SIV), strain smm3, 13 animals developed malignant Non-Hodgkin lymphomas. These lymphomas presented with unusual primary manifestations like in the orbita, testes, and brain. The morphological features and immunophenotyping identified the tumors as high malignant B-cell lymphomas. In all tumors as well as in tumor-derived cell lines a cynomolgus B-lymphotropic herpes virus (CBLV) with structural homogeneity to the Epstein-Barr virus (EBV) could be demonstrated by Southern blotting with EBV-specific probes. The lymphoma cells also expressed CBLV-associated nuclear antigens involved in B-cell transformation crossreacting with EBNA-specific human sera and monoclonal antibodies. Ig-gene rearrangement studies revealed clonal populations, however, no translocations of the c-myc oncogene could be detected. The lymphomas developing with high frequency in SIV-induced immunodeficiency resemble a major subtype of human EBV-associated AIDS lymphomas. This animal model can therefore be used to further elucidate interactions of HIV and EBV in AIDS-related lymphomagenesis.
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PMID:[Opportunistic malignant lymphomas in SIV infected primates--a model for Epstein-Barr virus associated lymphomas in AIDS]. 128 56

Through interaction with antibody, IgG Fc receptors provide an interface between specific humoral immunity and Fc gamma R-bearing host cells. Fc gamma R trigger such diverse functions as immune complex clearance, phagocytosis of opsonized pathogens, reactive oxygen intermediate and enzyme secretion, and antibody-dependent cellular cytotoxicity (ADCC). Moreover, Fc gamma R are the exclusive trigger molecules for tumor cell killing by human myeloid cells. Studies of Fc gamma R function have been aided by the use of bispecific antibodies to link cells or pathogens to specific host cell molecules, including Fc gamma R. These reagents have permitted determination of the role of Fc gamma R in ADCC of the protozoan, Toxoplasma gondii, by human effector cells. This approach has also indicated that Fc gamma R do not serve as entry points for viruses such as dengue virus and HIV. Taken together, these results provide insight into the utility of manipulating Fc gamma R function in the therapy of cancer and infectious disease.
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PMID:Fc gamma receptors in cancer and infectious disease. 128 16

Clinical and paraclinical experience in HIV infection, though the time elapsed since the first observations is relatively short, begins to get typical outlines. In the case of AIDS, the lung is the main place of opportunistic infections, other inflammatory processes and neoplasia. The present work deals with six clinical cases with positive serum tests for HIV and secondary respiratory phenomena such as: Kaposi sarcoma, pneumonia with Pneumocystis carinii, tuberculosis, candidosis, pneumonia with common germs. Particular aspects of treatment and disease evolution are commented.
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PMID:[The pulmonary manifestations in AIDS]. 129 94

Certain human genital papillomaviruses (HPV) are strongly associated with cervical dysplasia and cancer. Evidence is accumulating that HPV infection and ano-genital cancers are more common in patients with the acquired immunodeficiency syndrome. The objective of our study was to evaluate the extent to which HPV infection and associated cervical disease constitute opportunistic complications of human immunodeficiency virus (HIV) infection in a population of sexually promiscuous, HIV-infected women in Kinshasa, Zaire. In 1989 we obtained Pap smears and cervicovaginal lavage specimens for HPV DNA testing from 47 HIV-seropositive and 48 HIV-seronegative prostitutes who were part of a cohort under observation since 1988. Thirty-eight percent of the HIV-seropositive and 8% of the seronegative women (odds ratio = 6.8; p = 0.001) had HPV DNA detected by either ViraType, a dot-blot assay which detects specific genital HPV types, or low-stringency Southern blot, which detects all HPV types. Eighty-two women (86%) had an interpretable Pap smear; 11 of 41 (27%) HIV-seropositive women and one of 41 (3%) seronegative women had cervical intra-epithelial neoplasia (CIN) (odds ratio = 14.7; p = 0.002). HIV seropositivity, HPV infection and CIN were highly associated. Eight (73%) of 11 seropositive women with CIN had HPV detected. Both HPV infection and cervical cancer may emerge as opportunistic complications of HIV infection in populations in which HIV, HPV and cervical cancer are common.
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PMID:Genital papillomavirus infection and cervical dysplasia--opportunistic complications of HIV infection. 130 59

The prevalence of lower genital neoplasia and Human Papilloma-virus-related genital lesions were evaluated in a cohort of 75 women with Human Immunodeficiency Virus type 1 (HIV-1) infection at different stages of HIV disease. The overall rate of cervical intraepithelial neoplasia (CIN) in the group studied was 29.3% (22/75). Eight out of 10 high-grade CIN lesions contained 'high-risk' HPV-DNA 16/18 and/or 31/35/51 as demonstrated by 'in situ' hybridization with biotinylated probes. Vulvar and/or perianal condylomata were histologically diagnosed in 14 patients (18.7%); nine of these biopsies contained detectable HPV-DNA which was always related to HPV 6/11. The rate of high-grade CIN in symptomatic HIV-infected patients was 28% (7/25) as compared to 6% (3/50) of the other cases (P = 0.022). CD4 lymphocyte counts, white blood cell counts, CD4+/CD8+ cell ratio and percentage of CD4+ lymphocytes were lower in patients with high-grade CIN in comparison to the patients with negative colposcopical and/or cytological examination. After adequate standard treatment (cryotherapy, electrocauterization, cold-knife conization) only one case of CIN 2 recurred during the 2 years of follow-up period. The prevalence of lower genital neoplasia and HPV-related lesions among HIV-infected women is high and seems to correlate with the severity of HIV disease.
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PMID:Prevalence, diagnosis and treatment of lower genital neoplasia in women with human immunodeficiency virus infection. 131 1

Southern blot hybridization and/or PCR was used to examine tumor biopsies of 53 women with cervical or vaginal cancer at Ocean Road Hospital in Dar es Salaam, Tanzania, and the cervical swabs of 359 women with no cancer at the gynecologic clinic at Muhimbili University College of Health Sciences in Dar es Salaam. Tanzanian and German scientists wanted to determine whether an association existed between human papillomavirus (HPV) infections and HIV, and whether the high prevalence of HIV infection was matched by a high prevalence of HPV infections, cervical dysplasias, and cervical cancer in HIV-positive cases. 59% of the noncancerous women had HPV-DNA. Young age and HIV infection were the greatest risk factors for HPV-DNA in these women (p .0001 for age and HPV-16/18; p = .08 for other HPVs; and p = .03 for HIV). 13.2% and 17.5% of all HPV infections were HPV types 16 and 18, respectively. Tanzania had the highest prevalence of HPV 18 ever reported. HPV-16/18 risk factors included: Trichomonas vaginalis infection (odds ratio [OR] = 2.23; p = .04), single status (OR = 2.55; p = .01), 16 years old or less at first intercourse (OR = 2.1; p = .03), and young age at menarche (OR = 6 for or=12 years old; p = .02 and OR = 3.25 for or=13 years old and or=16 years old; p = .05). Yet, the multivariate analysis revealed young age at menarche had the greatest effect (OR = 6.2 for or= 12 years old, p = .03; OR = 3.73 for or=16 years old, p = .08). 12.8% of noncancerous women tested positive for HIV-1, but none of them were obviously symptomatic. These HIV-positive women had a higher OR if they had HPV-16/18 than if they had other HPV types (4.25 vs. 2.02). Further, they did not have more cervical cytological abnormalities than did the HIV-negative women (overall cervical cytological abnormality rate - 2.8%). The HIV-positive rate for cancerous patients was only 3%. In conclusion, no association existed between HIV infection and cervical cytological abnormalities or cervical cancer.
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PMID:Human papillomavirus (HPV) infection, HIV infection and cervical cancer in Tanzania, east Africa. 131 65

The data presented here indicate that the pathogenesis of AIDS-NHL is variably associated with multiple genetic alterations including monoclonal EBV infection, oncogene activation (c-myc, N-, Ki-ras) and tumor suppressor gene (p53) inactivation. Up to three (3 cases) or four (1 case) different lesions have been observed in the same tumor. The distribution of these lesions among the various histotypes is heterogeneous, although some preferential associations have been found either between lesion and histotype or between lesions. The most notable case involves p53 mutations/loss that is exclusively associated with the SNCC lymphoma subtype. Since alterations of the c-myc gene occur at very high frequency in this same histotype it is possible that both lesions may be required for the pathogenesis of the BL phenotype. The consistent negativity of p53 lesions in other NHLs associated or non associated with HIV infection (18) reinforces this hypothesis. Finally, we note that the frequency of p53 mutations is significantly higher in AIDS-BL than in non HIV-related BL (18), although the significancy of this difference remains to be assessed. This study confirms the relatively low frequency of EBV infection in systemic AIDS-NHL in general, but reinforces the notion that EBV may be required for the pathogenesis of AIDS-LC-IBP, as recently suggested by the high frequency of EBV positivity in primary CNS AIDS-NHL which are mostly represented by LC-IBP (2). Conversely, the low frequency of EBV sequences in the AIDS-SNCC lymphomas appears similar to that observed in sBL. Only in a small minority of cases were ras oncogene mutations found, mostly associated with the BL type.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Molecular pathogenesis of HIV-associated lymphomas. 132 69

The ability of HIV-1 envelope glycoprotein gp120 to induce transmembrane signaling processes in human T cells and tumor T-cell lines was investigated. Differently glycosylated gp120 preparations were characterized with respect to their purity, the fraction of native gp120, and the affinity of the gp120-CD4 interaction. These data were used to establish experimental conditions that allow a substantial fraction of the CD4 receptor to be complexed with gp120 in the course of the experiments. The results are in contrast to several previous studies since no effect of gp120 on the intracellular Ca2+ concentration, the metabolism of inositol phosphates and arachidonic acid, protein kinase C translocation, and tyrosine phosphorylation was found. Cross-linking of the gp120:CD4 complex by anti-gp120 antibodies did not elicit additional effects.
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PMID:The HIV-1 surface protein gp120 has no effect on transmembrane signal transduction in T cells. 132 56

We report the detailed clinical features of discrete mass lesions of the gastrointestinal tract caused by cytomegalovirus in three patients who had the acquired immunodeficiency virus syndrome. The disease occurred in the fundus of the stomach in one patient and in the cecum in the other two persons. The symptoms as well as radiographic and endoscopic findings in each case are described and are shown to be indistinguishable from those resulting from a neoplasm. The diagnosis was established by the presence of inflammation with cytomegalovirus-like inclusions and confirmed by immunoperoxidase staining. Cytomegalovirus infection should be considered, along with Kaposi's sarcoma and lymphoma, as a cause of focal mass lesions of the alimentary tract in persons infected with HIV.
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PMID:Discrete gastrointestinal mass lesions caused by cytomegalovirus in patients with AIDS: report of three cases and review. 133 13


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