1/8. Scopulariopsosis and hypersensitivity pneumonitis in an addict.Granulomatosis caused by fungal spores of a soil saprophyte is a newly recognized pulmonary complication of intravenous drug addiction. Brown, non-budding spores were histologically identified in necrotic tissue, inside giant cells of sarcoidlike granulomata, and in the vicinity of focal angiitic lesions. The fungus was identified by culture as the dematiaceous scopulariopsis brumptii. Cultural and histopathologic studies of lung biopsy specimens established the diagnosis. We showed precipitating antibodies to fungal antigen in the serum, prepared from the patient's isolate. Similar granulomatous pulmonary lesions were experimentally produced in mice by a single intravenous injection of spores of S. brumptii. The spores remained viable but did not show evidence of growth in the animal's tissue. Precipitating antibodies to fungal antigen and immediate wheal and late necrotizing type of skin reactions were shown in the challenged mice. The studies support the notion that pulmonary hypersensitivity to fungal spores was mediated by an Arthus'-type phenomenon.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
2/8. Human equivalent of the mouse Nude/SCID phenotype: long-term evaluation of immunologic reconstitution after bone marrow transplantation.Human Nude/SCID (severe combined immunodeficiency) is the first severe combined immunodeficiency caused by mutation of the winged-helix-nude (WHN) gene, which is expressed in the thymus but not in the hematopoietic lineage. The disease is characterized by a T-cell defect, congenital alopecia, and nail dystrophy. A Nude/SCID patient who underwent bone marrow transplantation from the human leukocyte antigen-identical heterozygote brother was studied to investigate, in this unique model, the role of the thymus in immunologic reconstitution. Despite an increase in CD3( ), CD4( ), and CD8( ) cells, CD4( ) CD45 RA naive lymphocytes were not regenerated. Conversely, naive CD8( ) cells were normal. After an initial recovery, lymphocyte proliferation to mitogens progressively declined compared with controls and genotypically identical donor cells grown in the WHN( /-) environment. Analysis of the T-cell receptor (TCR) repertoire of CD4( ) cells revealed that only 3 of 18 Vbeta families had an altered CDR3 heterogeneity length profile. Conversely, CD8( ) lymphocytes showed an abnormal distribution in most Vbeta families. These data indicate that the thymus is differentially required in the reconstitution of CD4( ) and CD8( ) naive subsets and in the maintenance of their TCR repertoire complexity. Taken together, these findings suggest that bone marrow transplantation is ineffective in the long-term cure of this form of SCID.- - - - - - - - - - ranking = 0.5keywords = antigen (Clic here for more details about this article) |
3/8. Clinical and experimental progression of a new model of human prostate cancer and therapeutic approach.We report the clinical evolution of a prostate cancer, metastasizing to lungs and bones, recurring locally, and escaping from anti-androgen therapy. Key event of biological progression of the patient's tumor was the coincidence of allelic imbalance accumulation and of bone metastases occurrence. The recurrent tumor was established as the transplantable xenograft PAC120 in nude mice, where it grew locally. PAC120 displayed the same immunophenotype of the original tumor (positive for keratin, vimentin, prostatic acid phosphatase, and Leu-7) and expressed human HOXB9, HOXA4, HER-2/neu, and prostate-specific antigen genes, as detected by reverse transcriptase-polymerase chain reaction. It formed lung micrometastases detected by mRNA expression of human genes. cytogenetic analysis demonstrated numerous alterations reflecting the tumor evolution. PAC120 was still hormone-dependent; its growth was strongly inhibited by the new gonadotropin-releasing hormone antagonist FE 200486 but weakly by gonadotropin-releasing hormone superagonist D-Trp(6)-luteinizing-hormone releasing hormone (decapeptyl). Tumor growth inhibition induced by anti-hormone therapy was linked to the hormone deprivation degree, more important and more stable with FE 200486 than with D-Trp(6)-luteinizing-hormone releasing hormone. Surgical castration of mice led to tumor regressions but did not prevent late recurrences. Transition to hormone-independent tumors was frequently associated with a mucoid differentiation or with a neuroendocrine-like pattern. Independent variations of mRNA expression of HER-2/neu and prostate-specific antigen were observed in hormone-independent tumors whereas HOXB9 gene expression was constant. In conclusion, PAC120 xenograft, a new model of hormone-dependent prostate cancer retained the progression potential of the original tumor, opening the opportunity to study the hormone dependence escape mechanism.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
4/8. Antibody response to IR6, a conserved immunodominant region of the VlsE lipoprotein, wanes rapidly after antibiotic treatment of borrelia burgdorferi infection in experimental animals and in humans.Invariable region (IR)(6), an immunodominant conserved region of VlsE, the antigenic variation protein of borrelia burgdorferi, is currently used for the serologic diagnosis of lyme disease in humans and canines. A longitudinal assessment of anti-IR(6) antibody levels in B. burgdorferi-infected rhesus monkeys revealed that this level diminished sharply after antibiotic treatment (within 25 weeks). In contrast, antibody levels to P39 and to whole-cell antigen extracts of B. burgdorferi either remained unchanged or diminished less. A longitudinal analysis in dogs yielded similar results. In humans, the anti-IR(6) antibody titer diminished by a factor of > or =4 in successfully treated patients and by a factor of <4 in treatment-resistant patients. This result suggests that the quantification of anti-IR(6) antibody titer as a function of time should be investigated further as a test to assess response to lyme disease therapy or to determine whether a B. burgdorferi infection has been eliminated.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
5/8. A neuroendocrine/small cell prostate carcinoma xenograft-LuCaP 49.The late stages of progression of prostate carcinoma are typically characterized by an androgen-insensitive, rapidly proliferative state. Some late-stage tumors are composed predominantly of neuroendocrine cells. Virtually no animal models of a neuroendocrine/small cell variant of prostate carcinoma are available for experimental studies. We report a human neuroendocrine/small cell prostate carcinoma xenograft that was developed from a nodal metastasis of a human prostate carcinoma and that has been propagated as serial subcutaneous implants in severe combined immunodeficient mice for >4 years. Designated LuCaP 49, all tumor passages exhibit a neuroendocrine/small cell carcinoma phenotype-insensitivity to androgen deprivation, expression of neuroendocrine proteins, lack of expression of prostate-specific antigen or androgen receptor, and an unusually rapid growth (a doubling time of 6.5 days) for prostate cancer xenografts. Genetically this tumor exhibits loss of heterozygosity for the short arm of chromosome 8 and has a complex karyotype. This xenograft should prove to be useful in the investigation of mechanisms underlying the androgen-insensitive state of progressive prostate carcinoma.- - - - - - - - - - ranking = 0.5keywords = antigen (Clic here for more details about this article) |
6/8. Pathogenesis of cerebral cryptococcus neoformans infection after fungemia.The pathogenesis of cerebral infection after cryptococcus neoformans fungemia in outbred mice was investigated. Confocal microscopy and cultures on ficoll-hypaque gradient-separated blood cells were used to detect yeasts in the cytoplasms of monocytes. In semithin brain sections, poorly capsulated yeasts were seen in macrophages in the leptomeningeal space, in monocytes circulating in leptomeningeal capillaries, or in the endothelial cells themselves, strengthening the hypothesis that monocytes and endothelial cells play key roles in the pathogenesis of cryptococcal meningitis. Similar fungal loads and cellular reactions were seen in mice and in 1 patient with acquired immune deficiency syndrome (AIDS), all with acute cryptococcal meningoencephalitis, and in mice and in 1 patient with AIDS, all with cured cryptococcal infection. Immunostaining revealed both the presence of cryptococcal polysaccharide in various brain cells and antigenic variability both from yeast cell to yeast cell and over time. Thus, our data established the relevance and interest that this experimental model has for investigation of the pathogenesis of human cryptococcal meningitis.- - - - - - - - - - ranking = 0.5keywords = antigen (Clic here for more details about this article) |
7/8. autoantibodies to glutamate receptor GluR3 in Rasmussen's encephalitis.Rasmussen's encephalitis is a progressive childhood disease of unknown cause characterized by severe epilepsy, hemiplegia, dementia, and inflammation of the brain. During efforts to raise antibodies to recombinant glutamate receptors (GluRs), behaviors typical of seizures and histopathologic features mimicking Rasmussen's encephalitis were found in two rabbits immunized with GluR3 protein. A correlation was found between the presence of Rasmussen's encephalitis and serum antibodies to GluR3 detected by protein immunoblot analysis and by immunoreactivity to transfected cells expressing GluR3. Repeated plasma exchanges in one seriously ill child transiently reduced serum titers of GluR3 antibodies, decreased seizure frequency, and improved neurologic function. Thus, GluR3 is an autoantigen in Rasmussen's encephalitis, and an autoimmune process may underlie this disease.- - - - - - - - - - ranking = 0.5keywords = antigen (Clic here for more details about this article) |
8/8. Engraftment of chronic prolymphocytic and T cell leukemia in SCID mice.Engraftment of human acute leukemia cells in immunocompromised (SCID) mice has resulted in in vivo models for exploration of human tumor biology. Attempts at engraftment of chronic leukemia cells have been generally unsuccessful. We have engrafted cells from three human chronic leukemias in SCID mice. Cell populations were from two patients with chronic lymphocytic leukemia (CLL) and either increased proolymphocytes (CLL-Pro; patient 1), or prolymphocytic transformation (PLL; patient 2) and from a third patient with newly diagnosed T cell CLL. Both fresh and cryopreserved cells were used and were injected intravenously, intraperitoneally, or both, after conditioning with cyclophosphamide. In addition, cells derived from a mouse spleen engrafted with human leukemia were passaged into another mouse. The animals were observed daily for signs of disease or appearance of tumors and sacrificed when terminally ill. At intervals blood samples were obtained and analyzed for the presence of human cells or dna. Human leukemic cells were demonstrated by polymerase chain reaction (PCR) analysis of the human DQalpha gene or positive staining for human leukocyte common antigen (LCA). The presence of Epstein-Barr virus (EBV)-positive cells was also investigated by PCR analysis. Disseminated tumors developed in most mice inoculated with cells from the first patient, and this was associated with shortened survival times. The methods of administration, use of fresh or frozen samples, or the size of the inoculum had no effect on the development of leukemia. survival of the mouse receiving passaged cells was similar to mice inoculated with fresh cells. Extensive histologic, immunophenotypic, and dna studies were performed on organs from mice engrafting with cells from patient 1. PCR analysis for EBV sequences was negative in the mice engrafting from all three cases. The successful engraftment of human CLL-Pro PLL and T cell CLL in SCID mice, and the reproducibility of this effect using frozen cells, will provide a model for exploration of disease biology and for investigations of new drugs or combinations that may be useful in the treatment of CLL.- - - - - - - - - - ranking = 0.5keywords = antigen (Clic here for more details about this article) |