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Preliminary report of an open-label, multicenter, phase I/II study of AT-101 in combination with docetaxel (D) and prednisone (P) in men with docetaxel refractory prostate cancer. J Clin Oncol 2009. [DOI: 10.1200/jco.2009.27.15_suppl.5145] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
5145 Background: Antiapoptotic Bcl-2 family proteins are overexpressed in castrate resistant prostate cancer (CRPC) and contribute to resistance to therapy. AT-101 is a pan-Bcl-2 inhibitor (Bcl-2, Bcl-XL, Bcl-W, and Mcl-1) and potent inducer of proapoptotic proteins. AT-101 is active as a single agent and in combinations with standard therapies in in vitro and in vivo tumor models, as a single agent in a phase II trial in CRPC, and in combination with D/P as first-line therapy in CRPC, as demonstrated by declines in PSA and RECIST responses. Methods: Men ≥18 years of age with docetaxel-refractory CRPC were eligible. Patients (pts) must have PSA progression per the Bubley criteria or documented disease progression while receiving prior D/P therapy. Pts (n = 40) were treated with D (75 mg/m2 day 1), P (5mg b.i.d. on days 1–21) and AT-101 40mg b.i.d. on days 1–3 of each 21-day cycle. Safety (NCI CTCAE v3.0) and efficacy (Bubley Criteria for PSA) were assessed at 3-wk intervals. Radiological assessments were performed at 6-wk intervals for pts with soft tissue disease and bone scans were performed after cycle 6 and at the completion of therapy. Results: Efficacy data was available on 34 pts. Thirty-five percent (12/34) of pts treated had at least a 30% decrease in PSA level and 18% (6/34) of pts achieved a >50% PSA decline. Twenty one of 34 pts included in this analysis had measurable disease. Five pts (24%) with measurable disease had a PR or CR by RECIST criteria and one additional patient had tumor shrinkage of 29%. Two (2) RECIST PRs are unconfirmed. Thus far, 3 pts have been on therapy for 6 months or more and 15 pts remain on study. Safety data was available on 22 pts. The most common (>20%) adverse events (AEs) included fatigue (55%), anorexia, including weight decreased (45%), diarrhea and nausea (27%), vomiting and neutropenia (23%). The grade 3/4 AEs occurring in more than 1 pt were: neutropenia (5), anemia, anorexia, dyspnea and leukopenia (2 pts each). One partial small bowel obstruction was the only related, serious adverse event (SAE) reported to date. Conclusions: This data supports that AT-101 can be administered safely with D/P in pts with CRPC who are docetaxel-refractory. Durable PSA and RECIST responses were observed. [Table: see text]
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An open-label, multicenter, phase I/II study of AT-101 in combination with docetaxel (D) and prednisone (P) in men with hormone refractory prostate cancer (HRPC). J Clin Oncol 2008. [DOI: 10.1200/jco.2008.26.15_suppl.16043] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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457 Interim evaluation of a multi-institution phase I/II study of antisense oligonucleotide GTI-2040 (G) and capecitabine (C) in patients with metastatic renal cell carcinoma (mRCC). EJC Suppl 2004. [DOI: 10.1016/s1359-6349(04)80465-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Hantavirus infection in people inhabiting a highly endemic region of the Gran Chaco territory, Paraguay: association with Trypanosoma cruzi infection, epidemiological features and haematological characteristics. ANNALS OF TROPICAL MEDICINE AND PARASITOLOGY 2003; 97:269-80. [PMID: 12803858 DOI: 10.1179/000349803235001903] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The seroprevalences of anti-hantavirus antibodies were determined in 712 individuals (551 Indians, 140 Mennonites of German ancestry, and 21 Paraguayans of Spanish ancestry) inhabiting a region of western Paraguay in the Gran Chaco territory of South America. The overall seroprevalence of hantavirus infection among the 712 subjects, who were aged 2-80 years, was 42.7% (45.2% in the Indians and 34.2% in the non-Indians). Of the 672 subjects also checked for antibodies against Trypanosoma cruzi, 226 (33.6%) were seropositive for this protozoan parasite. The results of a multivariate regression analysis indicated that, after adjusting for age, sex, setting of residence (rural/urban) and infection with the human T-cell leukaemia/lymphoma virus type II (HTLV-II), a T. cruzi-seropositive individual was 1.73 times more likely to be hantavirus seropositive than a T. cruzi-seronegative individual. Living in a rural setting increased the risk of being hantavirus seropositive 2.17-fold. In both the Indians and non-Indian subpopulations, hantavirus seroprevalence increased with age in both sexes, but only in the non-Indian supopulation was this increase significantly greater in males than in females. Hantavirus seropositivity was significantly associated with thrombocytosis, even after adjusting for the relevant confounders.
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Abstract
DNA was extracted from the peripheral blood of a seropositive, PCR-positive, BLV-infected Holstein cow (No. 38) from Argentina. The DNA was amplified via PCR with a series of overlapping primers encompassing the entire BLV proviral DNA. The amplified BLV ARG 38 DNA was cloned, sequenced, and compared phylogenetically to three other full-length BLV sequences. Characterization of its deduced proteins and its relationship to other members of the PTLV/BLV genus of retroviruses are discussed.
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Cytokine replacement in patients with HIV-1 non-Hodgkin's lymphoma: the rationale for low-dose interleukin-2 therapy. THE CANCER JOURNAL FROM SCIENTIFIC AMERICAN 2000; 6 Suppl 1:S45-51. [PMID: 10685658] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
PURPOSE The drastic increase in the incidence of non-Hodgkin's lymphoma in patients infected with HIV-1 is testimony to the fact that our immune system is critical for the prevention of certain malignancies. Preclinical and clinical studies were conducted to (1) gain further insight into defects in immunity that can lead to malignant transformation and (2) determine if certain immune deficiencies could be corrected by cytokines delivered at doses that result in near-physiologic concentrations in vivo. METHODS We have used the severe combined immune deficient mouse engrafted with human peripheral blood leukocytes from healthy individuals who are seropositive for the Epstein-Barr virus to study the spontaneous development of malignant Epstein-Barr virus-positive human B-cell lymphoproliferative disorder. RESULTS We have demonstrated in this model that, in the absence of CD4+ T cells, cytokine replacement with low-dose interleukin (IL)-2 therapy can prevent Epstein-Barr virus-positive human B-cell lymphoproliferative disorder by interacting with mouse natural killer and human CD8+ T cells. We review our clinical experience with administration of low-dose IL-2 therapy in patients with HIV-1-related cancer, noting minimal toxicity and significant immune modulation. We provide evidence that this therapy can favorably alter the type 1 cytokine profile in vivo in these patients, and improve the cellular response to infectious insults in vitro. CONCLUSION Early clinical studies with low-dose IL-2 therapy in patients with HIV-1-related lymphoma suggest that this therapy may have a role in the prevention and treatment of this disease.
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Comparison of human immunodeficiency virus 1 DNA polymerase chain reaction and qualitative and quantitative RNA polymerase chain reaction in human immunodeficiency virus 1-exposed infants. Pediatr Infect Dis J 1999; 18:30-5. [PMID: 9951977 DOI: 10.1097/00006454-199901000-00009] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND HIV-1 RNA PCR is a widely available and sensitive assay but has not been studied for use in early diagnosis of HIV-1 infection in infants. METHODS Research HIV-1 DNA PCR and HIV-1 RNA PCR were performed on peripheral blood mononuclear cells and plasma, respectively, from 284 blood samples from 204 infants. A commercially available HIV-1 quantitative RNA PCR was also performed on plasma from the 132 samples from HIV-1-infected infants and 22 of the samples from HIV-1-uninfected infants. RESULTS Sensitivities of all assays varied with infant age. HIV-1 DNA PCR had a sensitivity of 27% in the < or = 3-week age group (n = 11) whereas qualitative and quantitative RNA PCR had sensitivities of 64 and 55%, respectively (P not significant). Each assay had a sensitivity of 96.2% at 4 to 6 weeks (n = 26) and 100% at > or = 7 weeks of age (n = 95). Specificity of HIV-1 DNA PCR for all age groups was 100%, whereas specificities of qualitative and quantitative RNA PCR assay were 96.1 and 95.5%, respectively. CONCLUSIONS HIV-1 RNA PCR may offer a slight advantage in sensitivity over DNA PCR in the diagnosis of HIV infection in young infants. Positive RNA results can be found in a small number of infants who are not HIV-1-infected. HIV-1 RNA detection should not be routinely used alone for the diagnosis of HIV infection in young infants.
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Synergy, activity and tolerability of zidovudine and interferon-alpha in patients with symptomatic HIV-1 infection: AIDS Clincal Trial Group 068. Antivir Ther 1996; 1:77-88. [PMID: 11321183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
Thirty-four subjects with symptomatic HIV-1 infection, p24 antigenaemia, and CD4 cell counts > 200/mm3 were randomly assigned to receive treatment with either zidovudine (ZDV) orally, interferon-alpha (IFN-alpha) subcutaneously, or both at respective low (200 mg ZDV/ 2 million international units IFN-alpha (MIU)), middle (400 mg/4 MIU) or high (600 mg/6 MIU) daily dose levels for 12 weeks. Thereafter, all patients received combination therapy at the initially assigned dose level to a total of 96 weeks. This design permitted analysis by the combination index (CI) method, which demonstrated antiretroviral synergy between ZDV and IFN-alpha with respect to p24 antigen suppression. Over the first 12 weeks, combination therapy was acceptably tolerated, more so than IFN-alpha monotherapy, and it was significantly more active in suppressing antigenaemia than either of the monotherapies. Similarly, the high-dose combination was the most active dose level over weeks 12 to 96. Combination ZDV/IFN-alpha at the optimal dose level defined by this trial merits further study. In addition, the CI design strategy employed here may be useful for the investigation of new antiretroviral combinations.
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Prolonged administration of low-dose interleukin-2 in human immunodeficiency virus-associated malignancy results in selective expansion of innate immune effectors without significant clinical toxicity. Blood 1995; 86:3287-94. [PMID: 7579429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Ten adult patients with human immunodeficiency virus (HIV)-associated malignancies (five with lymphoma and five with Kaposi's Sarcoma) were treated with a daily subcutaneous injection of interleukin-2 (IL-2) for 90 consecutive days in a phase I dose-escalation study. Seven patients had absolute CD4 counts below 200/mm3 at the time malignancy was diagnosed. Each lymphoma patient had obtained a complete or partial remission with standard chemotherapy before initiating IL-2. The daily dose of IL-2 did not change during the 90-day course of therapy. Seventeen courses of IL-2 therapy were completed at doses ranging from 0.4 x 10(6) U/m2/d to 1.2 x 10(6) U/m2/d without significant (grade III) toxicity. Two of two patients experienced grade III toxicity within 21 days of initiating IL-2 at a dose of 1.4 x 10(6) U/m2/d, but both patients subsequently completed 90 days of therapy at the maximum tolerated dose (MTD) of 1.2 x 10(6) U/m2/d. Although there were no significant increases or decreases in T-cell subsets at any dose level, there was an increase in absolute natural killer (NK) cell number at the three highest doses of IL-2 (mean percent increase 247; 95% confidence interval, 124 to 369) that was statistically significant (Wilcoxon one-sample signed rank test, P = .015). One patient developed an anti-IL-2 antibody titer that correlated with minimal NK cell expansion in vitro and in vivo. An increase in eosinophils was noted during 9 of 17 courses of IL-2 therapy without correlation to IL-2 dose, prior course of IL-2, or NK cell expansion. At the MTD, there was no consistent increase in the plasma HIV RNA level over time. Three of 10 patients had progressive disease while on study. During 50 months of IL-2 therapy, no patient was treated for an opportunistic infection. We conclude that daily low dose subcutaneous IL-2 can be self-administered safely with good compliance for prolonged periods of time to patients with HIV-associated malignancies, including those with profound immune deficiency. The majority of patients show selective expansion of innate immune effectors, ie, NK cells and/or eosinophils, in the absence of significant clinical toxicity or increased viral burden. These results suggest that low-dose IL-2 therapy should be studied further in phase II clinical trials for evidence of activity against malignancy and opportunistic infection in this patient population.
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Abstract
The association between a new human herpesvirus-like agent and various forms of Kaposi's sarcoma was examined by PCR. The DNA sequences of this agent were detected in 7 of 8 classic Kaposi's sarcoma specimens, 12 of 12 AIDS-associated specimens from the United States, and 7 of 10 specimens from African endemic Kaposi's sarcoma. Polymorphism of the herpesvirus-like DNA in the Kaposi's tissue from different populations was observed by both single-strand conformational polymorphism and direct sequencing. Furthermore, the presence and expression of the virus was detected in some Kaposi's tumours by Southern and northern blotting. This herpesvirus may be involved in the pathogenesis of different kinds of Kaposi's sarcoma seen among distinct and unrelated populations.
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Abstract
Signature primer pairs designed for use with the polymerase chain reaction have been developed which can determine if a positive result originated from the intended target nucleic acid or from so-called "carry-over" contamination of previously amplified DNA. The 3' ends of each signature primer, SK339/341, SSK110/111, and SSK58/59 contain a viral specific sequence complementary to regions of either HIV-1, HTLV-I and II respectively. The 5' ends of each primer contain a non-human, non-viral (NHNV) signature sequence including restriction endonuclease sites for subsequent cloning. A fourth set of primers, SK338/340, consist solely of these NHNV sequences and are designed to anneal to any product previously amplified by the viral-specific signature primers. These primers were tested against their corresponding positive and negative DNA targets, to determine their specificity and sensitivity. As expected, the viral-specific signature primers detected the retroviral infected samples while no detectable amplification occurred in negative DNA controls. Primers SK338/340 did not amplify any viral positive or negative template DNA's. Samples spiked with amplified material generated from the viral-specific signature primers could be specifically amplified by the NHNV primers SK338/340. Primers SK338/340 were determined to be more sensitive than the viral-specific signature primers, ensuring the detection of extremely low amounts of carryover. This strategy may be useful in developing other retroviral or non-retroviral primers with a built-in signature sequence that can differentiate false positives from true positives in a subsequent confirmatory test.
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Progressive nemaline rod myopathy in a woman coinfected with HIV-1 and HTLV-2. THE MOUNT SINAI JOURNAL OF MEDICINE, NEW YORK 1993; 60:242-6. [PMID: 8345853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Nemaline-rod myopathy was recently reported in eight young males infected with human immune deficiency virus type 1 (HIV-1). A 41-year-old woman had a 2-year history of progressive proximal-muscle weakness. Muscle biopsy demonstrated the presence of nemaline rods, predominantly in type 1 fibers. She was coinfected with HIV-1 and HTLV-2, as evidenced by positive polymerase chain reaction and serology. There was no lymphopenia or CD4 lymphopenia, despite an abnormal T-cell subset ratio, high CD8 count, skin anergy, and depressed in vitro response to mitogens. This case raises the possibility that dual infection may play a role in the pathogenesis of the rare nemaline-rod myopathies of HIV-infected patients.
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Abstract
Human T-cell lymphotropic virus type one (HTLV-1) is associated with tropical spastic paraparesis or HTLV-I--associated myelopathy. We report 2 women with a spastic ataxic illness similar to HTLV-I--associated myelopathy infected solely with HTLV-II. Identification of HTLV-II infection was made serologically, by polymerase chain reaction, and by viral culture (in 1 woman). One woman, treated with 200 mg of danazol orally, three times daily, had pronounced improvement in ambulation, nocturnal spasticity, and nighttime urinary frequency. It appears that infection with HTLV-II may cause an illness similar to HTLV-I--associated myelopathy, but distinguished by the presence of ataxia.
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Pharmacokinetics and pharmacodynamics of granulocyte-macrophage colony-stimulating factor and zidovudine in patients with AIDS and severe AIDS-related complex. Antimicrob Agents Chemother 1993; 37:512-22. [PMID: 8460920 PMCID: PMC187701 DOI: 10.1128/aac.37.3.512] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Granulocytopenia is a complication of human immunodeficiency virus disease, as well as a toxic manifestation of zidovudine therapy. To evaluate pharmacokinetic and pharmacodynamic relationships, 11 AIDS-AIDS-related complex patients who had developed zidovudine-associated granulocytopenia (mean absolute neutrophil count, 1,077/mm3) were examined after addition of granulocyte-macrophage colony-stimulating factor (GM-CSF) to zidovudine. GM-CSF was administered as a daily (1.0 or 0.3 micrograms/kg) or every-other-day (0.3 micrograms/kg) subcutaneous dose over a 28-day period. Zidovudine was continued at the same daily dosage as was previously being administered. Of 11 patients, 7 (1.0 micrograms/kg, n = 5; 0.3 micrograms/kg, n = 2) had a pharmacologic response to GM-CSF with an increase to a mean absolute neutrophil count of 3,189 cells per mm3 at 4 weeks (P < 0.05). The peak concentration of GM-CSF in plasma ranged from 11.5 to 84.4 pg/ml, and the time to peak ranged from 1 to 3 h. No correlation between GM-CSF disposition and hematologic response was noted. A decreased plasma zidovudine-glucuronide/zidovudine ratio was noted after 1 week of GM-CSF, and an increase in the area under the plasma concentration-versus-time curve for zidovudine was found in three patients after 4 weeks. Low doses of GM-CSF can raise the granulocyte count in patients with zidovudine-induced neutropenia. The use of GM-CSF and zidovudine may represent a viable treatment option for persons with human immunodeficiency virus infection who develop neutropenia while receiving zidovudine but do not tolerate alternative nucleoside analogs. Further studies are needed to assess the complex interaction between these two agents.
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A phase II study of recombinant interleukin-2 with or without recombinant interferon-beta in non-Hodgkin's lymphoma. A study of the Cancer and Leukemia Group B. J Immunother 1992; 12:115-22. [PMID: 1504052 DOI: 10.1097/00002371-199208000-00006] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Interleukin-2 (IL-2) and interferon-beta (IFN-beta) have demonstrated activity against lymphoid malignancies, presumably mediated by the augmentation of lymphokine-activated killer (LAK) cell and natural killer (NK) cell activity. There is in vitro and in vivo evidence to suggest that the combination of IL-2 and IFN-beta is synergistic. The Cancer and Leukemia Group B (CALGB) conducted a randomized phase II trial of IL-2 with or without IFN-beta in 49 patients with relapsed or refractory non-Hodgkin's lymphoma (NHL). Overall toxicity was severe, with 17 patients experiencing life-threatening toxicity. Three patients had treatment-related deaths. Responses were noted in seven patients (17%). There were no meaningful differences between treatment arms in toxicity profile, response rate, or modulation of in vivo NK and LAK activity. We conclude that IL-2 with or without IFN-beta is not effective therapy for NHL in the doses and schedule used in this study.
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Amplification and analysis of specific DNA and RNA sequences of bovine leukemia virus from infected cows by polymerase chain reaction. J Clin Microbiol 1992; 30:185-91. [PMID: 1370847 PMCID: PMC265018 DOI: 10.1128/jcm.30.1.185-191.1992] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Bovine leukemia virus (BLV) is the etiologic agent of leukemia in cattle and is believed to cause decreases in milk productivity, fertility, and life span in infected cows. BLV is a type C retrovirus in the Oncovirinae subfamily. It is most closely related to human T-cell lymphoma/leukemia virus type I (HTLV-I) and type II (HTLV-II). Since the polymerase chain reaction (PCR) provides rapid and efficient amplification of DNA sequences, primers were designed to amplify regions of the polymerase (pol) and pX genes specific for BLV targets. These sets of primers consistently amplified as few as 10 copies of BLV DNA contained in a plasmid in the background of 1 microgram of either human or bovine chromosomal DNA. In addition, no amplification products were detected from cell lines infected with HTLV-I, HTLV-II, or human immunodeficiency virus type 1 or 2 by the BLV PCR systems. Samples of peripheral blood mononuclear cells from 18 cows, previously determined to be serologically positive or negative, were correctly identified in a blind study as containing proviral DNA by use of the BLV primers and probes. Cloning and sequencing of amplified products revealed finite sequence variations among a previously cloned BLV isolate, the wild-type virus, and the published genome. Reverse transcriptase-directed PCR with the primers for both BLV pol and BLV pX was performed on plasma from a BLV-infected cow and detected in vivo BLV RNA expression. In summary, we have developed a specific and sensitive assay using PCR for the detection and identification of BLV infections; this assay can now be applied to clinical and basic research questions in veterinary medicine.
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Chemotherapy with 5-fluorouracil (5-FU) and cisplatin or 5-FU, cisplatin, and vinblastine for advanced non-small cell lung cancer. A randomized phase II study of the cancer and leukemia group B. Cancer 1991; 67:2974-9. [PMID: 1646066 DOI: 10.1002/1097-0142(19910615)67:12<2974::aid-cncr2820671206>3.0.co;2-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Two hundred forty-seven patients with previously untreated nonresectable non-small cell lung cancer (NSCLC) were entered in a prospective, randomized Phase II trial. Response assessment was possible in 232 patients, and 237 patients were evaluable for survival. Thirteen partial responses (11%) and 5 regressions (4%) of evaluable disease were obtained for the 116 patients treated with 5-fluorouracil (5-FU) and cisplatin (C) (95% confidence interval [CI], 8.5% to 21.5%). The median time to progression was 2.2 months and the median survival time was 4.6 months for 5-FU plus C. Twenty-three partial responses (20%) and 4 regressions (3%) of evaluable disease were obtained for the 116 patients treated with 5-FU, C, and vinblastine (V) (95% CI, 15.3% to 30.7%). The median time to progression was 2.8 months and the median survival time was 5.6 months for 5-FU, C, and V. The 5-FU and C doses were equivalent in the two treatment regimens. Sixteen of 85 patients (19%) with a performance status of 0 and 18 of 103 patients (17%) with a performance status of 1 responded, whereas only 2 of 44 patients (5%) with a performance status of 2 or greater responded (P = 0.009). Patients who had received locoregional radiation therapy had a lower overall response rate then those in the no prior radiation therapy group (P = 0.028). The median survival time for patients with a performance status of 0 or 1 was 6.3 months compared with 1.9 months for patients with a performance status of 2 or greater (P less than 0.001). Performance status also appeared to be a significant factor for time to progression. More frequent and severe leukopenia, fever, genitourinary (GU) toxicity, and pulmonary toxicity was reported with 5-FU, C, and V. There were three treatment-related deaths with 5-FU, C, and V and one treatment-related death with 5-FU plus C. Grade III/VI myelotoxicity was not influenced by prior radiation therapy or performance status. Neither regimen is active enough to be considered as standard therapy for advanced NSCLC.
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Mechlorethamine, vincristine, and procarbazine chemotherapy for recurrent high-grade glioma in adults: a phase II study. J Clin Oncol 1990; 8:2014-8. [PMID: 2230893 DOI: 10.1200/jco.1990.8.12.2014] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
We undertook a phase II study of combination chemotherapy with mechlorethamine (nitrogen mustard) 6 mg/m2 intravenously day 1 and day 8, vincristine 2 mg intravenously day 1 and day 8, and procarbazine 100 mg/m2 orally days 1 through 14 (MOP) in adults with recurrent high-grade glioma. There were 31 patients entered and 27 patients assessable for response. The median age was 49 years old. All patients had prior maximal radiotherapy, and eight had previous chemotherapy. Responses were determined based on clinical and computed tomographic (CT) scan/magnetic resonance imaging (MRI) criteria. The response rate (partial response [PR] plus objective qualitative response [OQR] plus complete response [CR]) was 52% with one CR. The response rate was higher in patients with anaplastic astrocytoma as compared with glioblastoma multiforme (P less than .05). The median duration of response was 42 weeks. Median survival for all assessable patients was 30 weeks, and for responders, it was 60 weeks. Response was correlated with ability to decrease dexamethasone doses and improved performance status. Toxicity was mainly hematologic with leukopenia being common. There was one treatment-related death from listeria meningitis, and two patients developed Pneumocystis carinii pneumonia. There were three episodes of neutropenic fever. We conclude that MOP is active and merits further investigation in adult high-grade glioma.
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Abstract
Peripheral blood mononuclear cells (PBMCs) were recovered from platelet units of 61 blood donors who were HTLV-I positive and 3 blood donors who were HTLV-I negative on enzyme-linked immunosorbent assay (ELISA). Western blot analyses were performed on the sera and DNA was prepared from the PBMCs and analyzed by the polymerase chain reaction (PCR). Of the 61 repeatably reactive samples, 2 were positive, 26 were negative, and 33 were interpreted as indeterminate on Western blot. HTLV-II sequences were detected by PCR in one of the Western blot-positive samples, as well as in one Western blot-indeterminate sample that showed reactivity to p24 only. HTLV-I sequences were detected in the second Western blot-positive sample. HTLV sequences were not detected in the remaining samples, which suggested that the majority of individuals with indeterminate results on Western blots that used one set of commercially available reagents are not infected with HTLV. It is demonstrated in this study that PCR can be used not only to resolve the infection status of individuals with indeterminate Western blots but also to distinguish between HTLV-I and HTLV-II.
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Immunodetection of human T-cell lymphotropic virus type I core protein in biological samples by using a monoclonal antibody immunoassay. J Clin Microbiol 1990; 28:949-55. [PMID: 2191015 PMCID: PMC267844 DOI: 10.1128/jcm.28.5.949-955.1990] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
A monoclonal antibody-based enzyme immunoassay (EIA) has been developed for detection of human T-cell lymphotropic virus type I (HTLV-I) core protein. The monoclonal antibody (clone 6.11) specifically recognizes the p19 gag gene-encoded protein of the virus. The EIA was over 100 times more sensitive than reverse transcriptase measurement and was capable of responding to less than 500 pg of whole-virus lysate. The assay exhibited type specificity in that HTLV-II antigens failed to produce a positive signal. In addition, a panel of other viruses demonstrated no antigenic cross-reactivity. These included herpesviruses, measles virus, human immunodeficiency viruses, and others. Viral p19 was followed during the course of density gradient ultracentrifugation in the presence of detergent, where it was noted to associate with viral membrane proteins. In comparison, reverse transcriptase activity localized in fractions of higher density containing envelope-free cores. Of clinical interest, the EIA was used to detect HTLV-I antigen in the viral cultures of patients with HTLV-I-associated myelopathies and from symptom-free individuals with proviral integration.
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High prevalence of HTLV-II among intravenous drug abusers: PCR confirmation and typing. AIDS Res Hum Retroviruses 1990; 6:561-5. [PMID: 2187505 DOI: 10.1089/aid.1990.6.561] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The polymerase chain reaction (PCR) was used to confirm the presence of human T-cell lymphotropic viruses (HTLV) in intravenous drug users (IVDU) whose sera were reactive by immunofluorescence assay (IFA) for HTLV-1/-II antibody. Peripheral blood mononuclear cells from 41 IFA-positive and 19 IFA-negative individuals were analyzed. HTLV sequences were detected in 39/41 IFA-positive samples; 36 were HTLV-II positive and 3 were HTLV-I positive. Two IFA antibody-positives were negative by both PCR and by enzyme immunoassay (EIA). One IFA and EIA antibody-negative sample was positive for HTLV-II by PCR. This study indicates a high prevalence of HTLV-II among IVDUs and further demonstrates the feasibility of using PCR to differentiate between HTLV-I and -II.
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Abstract
Iproplatin (CHIP) was administered to 35 previously treated women with metastatic adenocarcinoma of the breast. The drug was given at a dose of 45 mg/m2 intravenously for 5 consecutive days and was repeated every 28 days. In this trial, there was one partial response and two patients with stable disease out of 29 evaluable patients. The median duration of response in patients with either a partial response or stable disease was 4.8 months. Myelosuppression was the major toxicity, 11 patients had severe thrombocytopenia and 3 severe neutropenia. Mild renal insufficiency, anemia, and nausea and vomiting were also noted. Iproplatin has limited activity in heavily pretreated women with advanced breast carcinoma; further studies in patients less heavily treated may show an improved response rate.
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Phase I trial of recombinant interleukin-2 and recombinant beta-interferon in refractory neoplastic diseases. JOURNAL OF BIOLOGICAL RESPONSE MODIFIERS 1989; 8:122-39. [PMID: 2786553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Interleukin-2 (IL-2) and beta-interferon (beta-IFN) are cytokines with profound immunobiological effects on T-cell and natural killer (NK) cell activity; IL-2 also induces lymphokine-activated killer (LAK) cell cytotoxicity in humans. Both lymphokines induce antineoplastic activity against several refractory tumors. This Phase I study of 50 patients assessed the toxicities, maximally tolerated dose (MTD), effects on certain immune effector cells, pharmacokinetics of IL-2, and development of antibodies to the combination of subcutaneously administered IL-2 and intravenously administered beta-IFN. Fever was common. Indomethacin reduced the incidence and severity of fever and was necessary to prevent it from becoming dose-limiting. Hypotension occurred but never required pressors or produced complications. Constitutional symptoms, local skin toxicity at the site of IL-2 injection, generalized desquamation, eosinophilia, nausea, and vomiting were also observed. One patient had reversible renal dysfunction. Two patients experienced drug-related dyspnea without evidence of capillary leak syndrome; neither required intubation. Fluid retention and cardiotoxicity were not observed. The MTD was 5 x 10(6) U/m2 s.c. of IL-2 and 2 x 10(6) U/m2 i.v. of beta-IFN when given in combination. Enhancement of in vivo NK cell cytotoxicity and proliferation of T4+, T8+, and NK cells occurred. In vivo induction of LAK cell cytotoxicity was observed in three patients. Four patients developed nonneutralizing anti-IL-2 IgG antibodies, but none developed antibodies to beta-IFN. Peak IL-2 serum levels typically occurred 4 h following drug administration. Serum levels were within a factor of 3 of the peak level in the period studied, 1-6 h postinjection. No complete responses occurred. One patient with rectal cancer and one with transitional cell carcinoma each had a partial response, and 13 other patients (5 with renal cell, 4 with colorectal, and 4 other cancers) had stable disease. Induction of NK cell cytotoxicity was seen more commonly in patients with stable disease than in those with progressive disease. Combined administration of these agents is feasible with acceptable toxicity, and Phase II trials are warranted.
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Anti-human immunodeficiency virus type 1 antibody complexes on platelets of seropositive thrombocytopenic homosexuals and narcotic addicts. Proc Natl Acad Sci U S A 1988; 85:9763-7. [PMID: 3200854 PMCID: PMC282861 DOI: 10.1073/pnas.85.24.9763] [Citation(s) in RCA: 68] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Patients with human immunodeficiency virus type 1 (HIV-1) infection develop an immunologic thrombocytopenic purpura associated with markedly elevated platelet IgG, IgM, and C3C4 as well as serum immune complexes determined by the polyethylene glycol (PEG) method. Analysis of their serum PEG-precipitable immune complexes as well as platelet acid eluates revealed the presence of anti-HIV-1 antibody existing as a complex that eluted in the void volume of a Sephadex G-200 gel-filtration column. The complex binds to washed normal platelets, whereas affinity-purified anti-HIV-1 (gp120) antibody does not. HIV-1 antigen or proviral DNA was not detectable in the immune complexes or platelet extracts. However, anti-antibodies directed against anti-HIV-1 antibody were detectable in the immune complexes as well as platelet eluates. Approximately 50% of eluted platelet IgG contained anti-HIV-1 antibody. Thus the markedly elevated platelet immunoglobulin is partly due to the presence of anti-HIV-1 antibody complexes. This may be responsible for the enhanced platelet clearance and thrombocytopenia in patients with acquired immunodeficiency syndrome-related immunologic thrombocytopenia.
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Characterization of a sequence of human T cell leukemia virus type I from a patient with chronic progressive myelopathy. J Infect Dis 1988; 158:1193-7. [PMID: 3198935 DOI: 10.1093/infdis/158.6.1193] [Citation(s) in RCA: 105] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
DNA from peripheral blood mononuclear cells of individuals with chronic progressive myelopathy (CPM) were extensively analyzed for the presence of human T cell leukemia virus (HTLV) type I-like sequences by using the polymerase chain reaction. The DNA samples were amplified with oligonucleotides from three separate regions of HTLV viral genomes. A portion of the amplified viral genome from a representative patient was sequenced after molecular cloning into bacteriophage M13. Sequence data indicate that HTLV type I and not a related virus is associated with CPM.
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Abstract
Nineteen previously untreated patients with colorectal cancer and measurable disease were treated with iproplatin (CHIP), 75 mg/m2 daily, for 5 days every 4 weeks for at least 2 courses. Toxicities included myelosuppression, mild nausea and vomiting, and rare mild nephrotoxicity. The dose-limiting toxicity was thrombocytopenia, which appeared to be cumulative. Dose reduction was frequently necessary. There were no toxic deaths. One partial response was observed, and four patients had stable disease for a median of 2 months. Iproplatin does not appear to have significant activity against colorectal cancer.
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Enzymatic amplification of HTLV-I viral sequences from peripheral blood mononuclear cells and infected tissues. Blood 1988; 72:1117-23. [PMID: 3167199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Human T-cell lymphotropic virus type I (HTLV-I) and human T-cell lymphotropic virus type II (HTLV-II) have been associated with adult T-cell leukemia/lymphoma (ATL) and a rare T-cell variant of hairy cell leukemia, respectively. Direct detection of viral nucleic acid in peripheral blood lymphocytes (PBLs) and infected tissues in carrier patients and those with chronic disease has proven refractory due to viral transcriptional dormancy and the small number of infected cells present. The investigators report here the successful application of the DNA amplification procedure, termed PCR, to the detection of these human oncoviruses. Judicious selection of specific oligonucleotides for primers and probes provides type-specific and simultaneous detection of these two retroviruses. The ability to amplify and detect highly conserved regions of these medically relevant viruses may facilitate the identification of, as yet, uncharacterized retroviruses.
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The short arm of chromosome 11 is a "hot spot" for hypermethylation in human neoplasia. Proc Natl Acad Sci U S A 1988; 85:5693-7. [PMID: 2840671 PMCID: PMC281826 DOI: 10.1073/pnas.85.15.5693] [Citation(s) in RCA: 151] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Inactivation of normally expressed genes may play a role in the formation and/or progression of human cancers. Methylation of cytosine in DNA could potentially participate in such alterations of gene expression. Abnormalities in DNA methylation are a consistent feature of human neoplasms, and we now show that these include not only previously recognized widespread genomic hypomethylation, but also regional increases in gene methylation. A hot spot for abnormal methylation of C + G-rich areas has been detected on the short arm of chromosome 11 in an area known to harbor tumor suppressor genes. This change occurs consistently in common forms of human cancer and appears early during the transformation of cells with viruses including members of the human T-cell leukemia (HTLV) family. Furthermore, in one chromosome 11 gene examined, calcitonin, the increased methylation in somatic tumor cells coincides with the presence of an "inactive" chromatin pattern in the transcriptional regulatory area. The increased regional DNA methylation demonstrated may then participate in or mark chromosomal changes associated with gene inactivation events that are central to the genesis and/or progression of human cancers.
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Identification of human immunodeficiency virus sequences by using in vitro enzymatic amplification and oligomer cleavage detection. J Virol 1987; 61:1690-4. [PMID: 2437321 PMCID: PMC254157 DOI: 10.1128/jvi.61.5.1690-1694.1987] [Citation(s) in RCA: 247] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Human immunodeficiency virus (HIV) has been associated with acquired immunodeficiency syndrome and related disorders. Assays to detect antibodies to HIV proteins have been developed and used to screen sera for the identification of individuals who have been exposed to the virus. Although these serological tests have significant sensitivity and specificity for detecting exposure to the virus, they do not provide direct identification of HIV. We report here the application of recently developed nucleic acid amplification and oligonucleotide-based detection procedures for the identification of HIV sequences in established infected cell lines and in cells cultured from infected individuals.
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Herpes zoster: a possible early clinical sign for development of acquired immunodeficiency syndrome in high-risk individuals. J Am Acad Dermatol 1986; 14:1023-8. [PMID: 3013955 DOI: 10.1016/s0190-9622(86)70127-8] [Citation(s) in RCA: 124] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Zoster is uncommon before the age of 50 years in immunologically normal individuals, but it occurs with increased frequency in people who are immunosuppressed. A retrospective review of 300 patients with acquired immunodeficiency syndrome associated with Kaposi's sarcoma, revealed that 8% had prior zoster, a rate that is sevenfold greater than historic controls of the same age. We prospectively examined forty-eight patients, with no known immunodeficiency or signs of AIDS or AIDS related complex (ARC), who presented with zoster localized to the thoracic region. Forty-one patients had known risk factors for AIDS and thirty-five had antibody to the AIDS-associated virus (AAV) at the time of presentation. One seropositive subject had no known risk factors. Absolute lymphocyte counts, lymphocyte OKT4/OKT8 ratios, and lymphocyte mitogen responses were all depressed in subjects with antibody to AAV when compared with seronegative individuals. Seven of thirty-three AAV antibody-positive subjects, who could be followed longitudinally, developed AIDS from 1 to 28 months (mean = 13) after zoster. One antibody-negative subject seroconverted to become AAV seropositive 16 months after zoster and developed Kaposi's sarcoma 1 month later. These eight subjects had persistently low lymphocyte OKT4/OKT8 ratios and elevated beta-2 microglobulin. In patients at risk for AIDS, the occurrence of zoster may be one sign that heralds the marked depression of cellular immunity associated with AIDS or ARC.
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Quantitative estimation by a standardized enzyme-linked immunosorbent assay of human T-cell lymphotropic virus type I antibodies in adult T-cell leukemia and acquired immune deficiency syndrome. J Clin Microbiol 1986; 23:212-6. [PMID: 3009530 PMCID: PMC268614 DOI: 10.1128/jcm.23.2.212-216.1986] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Sera from patients with adult T-cell leukemia and asymptomatic carriers of human T-cell lymphotropic virus type I (HTLV-I) from widely separated areas of the world reacted strongly in a standardized quantitative enzyme-linked immunosorbent assay procedure with HTLV-I viral antigen prepared from a strain isolated in the United States. There was a sharp differentiation of the values seen in the patients as compared with a normal population. Of the 35 acquired immune deficiency syndrome patients with Kaposi's sarcoma, only 2 were positive for HTLV-I antibodies in this test, and the distribution of the negative assay values in the other acquired immune deficiency syndrome patient sera was similar to that seen in the normal sera. Sera which contained extremely high levels of antibodies to other unrelated viruses (rubella virus, cytomegalovirus, and herpes simplex virus) all showed negative anti-HTLV-I results, in a pattern similar to the normal sera. Sera from patients with several autoimmune disease (systemic lupus erythematosus, rheumatoid arthritis, thyroiditis) as well as those with infectious mononucleosis or myeloma all also showed the normal distribution of negative results, in spite of the presence of very high levels of the autoantibodies, etc., associated with their illnesses.
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Antibody levels for cytomegalovirus, herpes simplex virus, and rubella in patients with acquired immune deficiency syndrome. J Clin Microbiol 1986; 23:318-21. [PMID: 3009534 PMCID: PMC268634 DOI: 10.1128/jcm.23.2.318-321.1986] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Significantly higher proportions of patients with acquired immune deficiency syndrome (AIDS) or lymphadenopathy syndrome (LAS) were positive for antibodies to cytomegalovirus (CMV) and herpes simplex virus (HSV) compared with control groups of commercial blood donors. In contrast, no differences were found in the incidence of individuals positive for antibodies to rubella in these groups of subjects. Of those positive for antibodies to CMV and HSV in each group, the mean antibody levels were significantly higher in AIDS-LAS patients compared with the controls. The entire distribution of antibody concentrations to CMV and HSV in AIDS patients was shifted upward, so that significantly more patients showed high values and significantly fewer showed low values, indicating hyperactive humoral immune responses to these viruses. In sharp contrast, the AIDS patients with antibody levels for rubella showed the same distribution of antibody levels as did two groups of controls. No correlation was found between concentrations of CMV and HSV antibodies in individual AIDS-LAS patients.
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Cell-mediated inhibition of tumor colony formation in agarose by resting and interleukin 2-stimulated human lymphocytes. Cancer Res 1985; 45:1464-8. [PMID: 3872166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Human nonadherent peripheral blood mononuclear cells (PBMC) isolated from nonimmunized donors were preincubated for 18 h in medium alone or medium containing the lymphokine interleukin 2 and subsequently cocultured with tumor cells derived from malignant tumor cell lines or from fresh human tumors. The cell suspensions were subsequently inoculated into agarose; 14 days later, new tumor colony formation was determined. Although the different tumor cells displayed a wide range of sensitivity to the PBMC, in each instance, the number of colonies formed by the tumor cells exposed to the PBMC was consistently reduced relative to that of control cells. The inhibitory effect on the colony-forming cells was especially pronounced with PBMC preincubated with interleukin-2 and was dependent on the ratio of tumor cells to PBMC in the culture. This assay system provides an alternative to the standard 51Cr release assays in assessing the immunomodulatory effects of lymphokines and in quantitating the cytolytic or cytostatic activity of various effector cells against neoplastic stem cells from established cell lines and from heterogeneous cell preparations derived from fresh human tumors.
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Characterization of the reverse transcriptase from a new retrovirus (HTLV) produced by a human cutaneous T-cell lymphoma cell line. Virology 1981; 112:355-60. [PMID: 6166122 DOI: 10.1016/0042-6822(81)90642-5] [Citation(s) in RCA: 230] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Immunological properties of a type C retrovirus isolated from cultured human T-lymphoma cells and comparison to other mammalian retroviruses. J Virol 1981; 38:906-15. [PMID: 6264163 PMCID: PMC171228 DOI: 10.1128/jvi.38.3.906-915.1981] [Citation(s) in RCA: 189] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
HTLV strain CR (HTLVCR) is a retrovirus which was isolated from a human T-cell lymphoma cell line. A protein of molecular weight 24,000 p24, was purified from this virus. Several results indicate that this p24 is an internal core protein of HTLVCR. (i) The p24 copurified with viral cores. (ii) It was labeled with 125I after disruption of the virus, but not when undisrupted virus was iodinated. (iii) The amount of p24 was directly proportional to the amount of HTLVCR. (iv) In chromatographic properties, the HTLVCR p24 behaved similarly to the major structural protein (24,000- to 30,000-molecular-weight protein) of other retroviruses. A rabbit antiserum raised against disrupted HTLVCR precipitated the labeled p24, and the precipitation was competed for by unlabeled HTLVCR and by cytoplasmic proteins from cells producing HTLVCR, but not by proteins from normal human cells, including normal growing human T-cells, and several cultured human cutaneous T-cell lymphoma lines. Proteins from several mammalian type B, type C, and type D viruses also failed to compete in this precipitation. Moreover, HTLVCR did not react in homologous and interspecies assays for p30 antigens of several mammalian type C and type D viruses. These observations agree with immunological comparisons between reverse transcriptase of HTLVCR and other retroviruses and nucleic acid sequence homology studies which indicate that the various HTLVCR isolates represent new retroviruses found in some human T-cell neoplasias.
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