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

As previously described, proliferation of Kaposi sarcoma (KS)-derived cells in vitro is dependent on the presence of platelet-derived growth factor (PDGF). To test the hypothesis that PDGF may also be a major growth factor for KS cells in vivo, we performed in situ hybridization and immunohistochemical staining for PDGF and PDGF receptors in tissue sections of AIDS-related KS. The data suggest that KS consists of two types of tumor cells. (i) The main population are spindle-shaped cells with elongated nuclei (KS-s cells). They reveal a strong expression of PDGF beta receptors but do not express the PDGF-A and PDGF-B isoforms. (ii) A minor population of KS cells express PDGF beta receptor as well as PDGF-A and PDGF-B (KS-p cells). These cells are often grouped in whorls and surrounding vascular slits. They reveal spherical nuclei with evenly distributed chromatin and inconspicuous nucleoli. PDGF alpha receptor is not expressed in either form of KS cells. The results suggest that the isoforms of PDGF and the PDGF beta receptor are differentially expressed in two different cell types in KS and that PDGF isoforms may contribute to the pathogenesis of KS.
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PMID:Expression of platelet-derived growth factor and its receptor in AIDS-related Kaposi sarcoma in vivo suggests paracrine and autocrine mechanisms of tumor maintenance. 132 24

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

In the USA, Kaposi's sarcoma associated with the acquired immunodeficiency syndrome (AIDS-KS) is ten times more common in homosexual or bisexual men than in heterosexual men with AIDS. One explanation for this finding is that AIDS-KS may be caused by an infectious agent. Because there is a high incidence of human papillomavirus (HPV) infection, especially HPV-16, in homosexual men, we have sought HPV DNA sequences in Kaposi's sarcoma. We used the polymerase chain reaction with a primer pair specific for the highly conserved E6 region of HPV-16 to detect HPV-16 homologous DNA fragments in tumour tissues from 97 patients with KS and in KS-derived cell cultures. HPV DNA sequences were found in 11 of 69 KS skin tumours from homosexual men with AIDS-KS, in 3 of 11 KS biopsy specimens from homosexual men who had no clinical or laboratory evidence of HIV-infection, and in 5 of 17 KS skin lesions from HIV-1-negative elderly men and women with classic KS. The same primer pair amplified HPV-16 homologous fragments from two different continuous cell cultures derived from pleural effusion fluid of patients with pulmonary AIDS-KS and two continuous cell cultures derived from KS skin lesions. The findings suggest that HPV-16-related DNA sequences are associated with different forms of KS and may have a role in the pathogenesis of this neoplasm.
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PMID:HPV-16-related DNA sequences in Kaposi's sarcoma. 135 72

In order to investigate the hypothesis that the spindle cells of Kaposi's sarcoma originate from dendrocytes, we stained 22 cases of cutaneous and extracutaneous Kaposi's sarcoma for the presence of factor XIIIa. We selected eight lesions from the skin, five from the oral mucosa, four from gastrointestinal mucosa, three from lymph nodes, and one each from esophagus and conjunctiva for this study. The majority of cutaneous and lymph node Kaposi's sarcoma lesions had a considerable number of dendrocytes admixed with the spindle tumor cells. Of the five oral mucosal lesions only three showed a focal presence of dendrocytes. No dendrocytes were observed in the lesions biopsied from the gastrointestinal mucosa, esophagus, and conjunctiva. Our findings suggest that the proliferation of dendrocytes seen within the lesions of Kaposi's sarcoma in the skin and lymph nodes probably represents a nonspecific host response in organs where they are normally present, and it is unlikely that they constitute the neoplastic cells of Kaposi's sarcoma.
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PMID:Dendrocyte population in cutaneous and extracutaneous Kaposi's sarcoma. 135 17

Kaposi's sarcoma (KS) is an uncommon cutaneous neoplasm with an increased incidence among Jews and Italians of Europe and North America and Negroes of equatory Africa. In recent years, several cases have been diagnosed in AIDS patients and in patients who have undergone organ transplantation or received immunosuppressant treatments. We have diagnosed five cases of KS over a 3-year period in our department. They include four men and one women, aged from 58 to 79 years, and who were born and had lived in Tainan. They all denied a history of homosexuality, multiple sexual partners, or drug abuse. HIV (Human immunodeficiency virus) screening test were negative. Two patients had taken 'black pills' (usually containing steroids) for a long period of time and also had generalized dermatophytosis. One of these two patients had a cytomegalovirus infection and died of Salmonella septicemia and upper GI bleeding. Although the English literature seems to indicate that KS is rare among Asians. Our present experience coupled with two other recently reported cases from Taiwan and the unpublished observations of some other dermatologists suggest that KS is not all that rare in Taiwan.
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PMID:[Kaposi's sarcoma in Tainan: report of five cases]. 135 63

In a pilot single blind study, beta-carotene (BC) supplementation produced, in ARC patients under current treatment, apparent recovery from asthenia, fever, nocturnal sweating, diarrhoea, loss in weight, and led as a result to an improvement in general health and working efficiency, but not to an improvement in multiple district lympho-adenopathies. Nevertheless, BC appeared to prevent progress to AIDS and, in addition, to lower the effective dosage of AZT used in one case of ARC developed into AIDS, producing a recovery from opportunistic infections and an inhibition of Kaposi sarcoma diffusion, in line with a two-fold rise in CD4 counts.
Med Oncol Tumor Pharmacother 1992
PMID:Short communication: possible activity of beta-carotene in patients with the AIDS related complex. A pilot study. 136 29

Kaposi's sarcoma (KS) presents with variable severity in the context of HIV infection. Various therapeutic approaches can be taken, and these are determined by the extent and location of KS lesions and the severity of tumor-related symptoms. New insights into the pathogenesis of KS lesions may provide innovative treatment strategies and a more rational basis for the control of this neoplasm.
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PMID:Medical management of AIDS patients. Kaposi's sarcoma. 137 98

The c-ets1 proteins are transcriptional activators expressed within endothelial cells during blood vessel development in chick embryos. The authors show by in situ hybridization that c-ets1 is transcribed in the endothelia during angiogenesis in human embryos, in granulation tissue, and especially during tumor vascularization. c-ets1 mRNAs were also detected in the fibrocytes of tumor stroma and in the spindle cells of Kaposi's sarcomas, regarded as cells of endothelial origin. It has been shown that the c-ets proteins activate transcription through a PEA3 motif that plays a role in the stimulation of transcription of urokinase-type plasminogen-activator (u-PA), stromelysin and collagenase genes. The authors demonstrate in vitro that the angiogenic factor TNF alpha increases transiently the amount of both c-ets1 and u-PA mRNA in confluent human umbilical vein endothelial cells. Therefore, the authors suggest that the c-ets1 proteins might regulate the transcription of the genes coding for matrix-degrading proteases, which are necessary for both angiogenesis and tumor invasion.
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PMID:c-ets1 proto-oncogene is a transcription factor expressed in endothelial cells during tumor vascularization and other forms of angiogenesis in humans. 137 May 94

Immunosuppressed persons are at greater risk of developing malignancies. In human immunodeficiency virus (HIV) immunosuppression the most common oral cancers are Kaposi's sarcoma and non-Hodgkin's lymphoma. Squamous cell carcinoma has also been reported to be associated with HIV disease. Kaposi's sarcoma is the most frequent neoplastic disease in acquired immunodeficiency syndrome and is by far the most common in the head and neck area. This article reviews the prevalence, clinical features, and management of these diseases in HIV infection.
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PMID:Head and neck malignancies associated with HIV infection. 137 99

Primary vascular tumors of lymph nodes other than Kaposi's sarcoma are very rare, as attested to by only a handful of case reports in the literature. Based on an analysis of 39 such cases, we could distinguish five major groups. Hemangiomas of capillary/cavernous, lobular capillary, and cellular types were composed of compact aggregates of blood-filled vessels, variable in size, that replaced the nodal architecture partly or almost completely; some appeared to have originated in the hilum or medulla. These hemangiomas either represented incidental findings in lymph nodes or were seen with solitary lymph node enlargement; the evolution was benign with no recurrence. A distinctive benign lesion occurring exclusively in inguinal lymph nodes, which we propose designating "angiomyomatous hamartoma," showed replacement of the nodal parenchyma by smooth muscle cells and fibrous tissue, in continuity with exuberant proliferation of muscular vessels in the hilum. Epithelioid vascular tumors, characterized by plump endothelial cells with dense eosinophilic cytoplasm and numerous vacuoles, exhibited a range of differentiation, from hemangioma with well-formed vascular channels (with or without tissue eosinophilia) to hemangioendotheliomas composed predominantly of cords and sheets of tumor cells lying in a hyaline-myxoid matrix. Epithelioid hemangioendothelioma was particularly likely to be mistaken for metastatic carcinoma, and local recurrence could occur. A variant, the spindle and epithelioid hemangioendothelioma, was characterized by the presence of an additional component of spindle cells. Another tumor we found, polymorphous hemangioendothelioma, is a previously uncharacterized borderline malignant vascular tumor exhibiting solid, primitive vascular and angiomatous patterns and relatively bland cytologic features. Lymphangiomas of lymph nodes usually showed simultaneous multifocal and extra-nodal involvement and were characterized by cystic endothelium-lined spaces filled predominantly with lymph fluid. It is important to recognize these primary vascular tumors of lymph nodes to avoid mistaking them for a variety of benign vasoproliferative lesions, Kaposi's sarcoma, angiosarcoma, and metastatic cancer.
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PMID:Primary vascular tumors of lymph nodes other than Kaposi's sarcoma. Analysis of 39 cases and delineation of two new entities. 831 16


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