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Biomedical subjects

C Reading

Publications and source records attributed to C Reading.

At least 19 recordsLinked to original sources
PubMed2006

Improvement in immune parameters and human immunodeficiency virus-1 viral response in individuals treated with 16alpha-bromoepiandrosterone (HE2000).

A randomised, double-blind, placebo-controlled study examined the safety, tolerance, immunological effect and anti-human immunodeficiency virus (HIV) activity of sub-cutaneously administered HE2000 (16alpha-bromoepiandrosterone) as monotherapy in treatment-naïve patients with HIV-1. Twenty-four patients received five sequential daily doses of 50 or 100 mg of HE2000 or placebo every 6 weeks for up to three courses, and were followed thereafter for 3 months. HE2000 was safe, with transient injection site reactions being the main side-effect. Peripheral blood samples, collected serially, were analysed for changes in immune cell phenotypes. Significant increases were observed in the numbers of circulating dendritic cells, early activated (CD69+ CD25-) CD8 T-cells and T-NK cells after administration of 50-mg doses of HE2000 (p < 0.05). Gene expression in peripheral blood mononuclear cells was analysed by real-time RT-PCR. Before treatment, HIV-1-infected patients had significantly elevated transcripts for a number of inflammatory mediators (p < 0.012). After 50 mg or 100 mg HE2000, but not after placebo, there were significant sustained decreases in IL-1beta, TNF-alpha, IL-6 and Cox-2 transcripts (p < 0.05). There were no significant differences in CD4 cell numbers, although patients receiving 50-mg doses demonstrated a significant decrease in viral load (- 0.6 log; p < 0.01). Anti-HIV-1 T-cell responses were analysed serially using GAG-peptides to stimulate cytoplasmic IFN-gamma responses. After three courses, the 50-mg dose group demonstrated a significant increase in CD8 T-cell response against two distinct GAG peptide pools (p < 0.03). These findings suggest that immune-based therapies may be able to impact viral load by decreasing inflammation and/or stimulating CD8 T-cells.

Adult↗
PubMed2005

Anti-inflammatory and immune regulatory properties of 5-androsten-3beta, 17beta-diol (HE2100), and synthetic analogue HE3204: implications for treatment of autoimmune diseases.

5-Androsten-3beta, 17beta-diol (HE2100), and a synthetic analogue HE3204 are regarded as immune-regulating hormones, because both induce changes in the reporter antigen-popliteal lymph node assay (RA-PLNA). Mice were injected in the footpad with either HE2100 or HE3204 (0.01-3 mg), and a nonsensitizing dose of trinitrophenyl ovalbumin (TNP-OVA) was used as bystander reporter antigen. Seven days later, nodes were removed and numbers of cells (CD3, CD4, CD8, CD19; flow cytometry), TNP-specific IgM, IgG1, and IgG2a antibody-forming cells (AFCs; ELISPOT assay), and cytokines (interleukin-4 [IL-4], interferon-gamma [IFN-gamma]; ELISA) were measured. HE2100 and HE3204 increased cell numbers in a dose-dependent fashion. T (helper and suppressor) cells and B cells were increased (>5-fold). HE3204 was apparently twice as potent as HE2100. Both increased the B/T ratio (fivefold), increased TNP-specific IgM and IgG1 ( approximately 50-fold), and induced IgG2a AFCs. Both increased IL-4 and IFN-gamma secretion (up to threefold). Both displayed anti-inflammatory activity in the murine model of carrageenan-induced pleurisy, as evidenced by reduced neutrophil numbers and exudate volumes. Our observations suggest that both HE2100 and HE3204 are immune-regulating steroid hormones that exhibit anti-inflammatory properties. HE2100 (1 mg/mouse per day) provided significant benefit when given at disease onset in the SJL/J female mouse model of experimental autoimmune encephalomyelitis. These compounds and their analogues are candidates for further testing in autoimmune diseases.

Amino Acid Sequence↗
PubMed2000

Transplantation with selected autologous peripheral blood CD34+Thy1+ hematopoietic stem cells (HSCs) in multiple myeloma: impact of HSC dose on engraftment, safety, and immune reconstitution.

OBJECTIVE: The aims of our study performed in myeloma were to evaluate the performance and the safety of Systemix's high-speed clinical cell sorter, to assess the safety and efficacy of deescalating cell dose cohorts of CD34+Thyl+ hematopoietic stem cells (HSCs) as autologous grafts by determining engraftment, and to assess the residual tumor cell contamination using polymerase chain reaction (PCR) amplification assays of patient-specific complementarity determining region III (CDR III) analysis for residual myeloma cells. MATERIALS AND METHODS: The clinical trial was performed in 31 multiple myeloma patients, using purified human CD34+Thyl+ HSCs mobilized from peripheral blood with cyclosphosphamide and granulocyte-macrophage colony-stimulating factor to support a single transplant after high-dose melphalan 140 mg/m2 alone (cohort 1) and with total body irradiation (TBI) (cohorts 2-5) after an HSC transplant cell dose de-escalation/escalation design. RESULTS: Twenty-three patients were transplanted. Engraftment data in the melphalan + TBI cohorts confirmed that HSC doses above the threshold dose of 0.8 x 10(6) CD34+Thy1+ HSCs/ kg provided prompt engraftment (absolute neutrophil count >0.5 x 10(9)/L day 10; platelet count >50 x 10(9)/L day 13). A higher rate of infections was observed in the early and late follow-up phases than usually reported after CD34+ selected or unselected autologous transplantation, which did not correlate with the CD34+Thy1+ HSC dose infused. Successful PCR for CDR III could only be performed in five patients on initial apheresis product and final CD34+Thy1+ HSC product and showed a median tumor log reduction >3.12. CONCLUSIONS: CD34+Thy1+ HSCs are markedly depleted or free of detectable tumor cells in multiple myeloma and are capable of producing fast and durable hematopoietic reconstitution at cell doses >0.8 x 10(6) CD34+Thy1+ HSCs/kg. The delayed immune reconstitution observed is not different from that described in unselected autologous bone marrow and peripheral blood mononucleated cells transplants in multiple myeloma and may be corrected by addition of T cells either to the graft or to the patient in the posttransplant phase.

Adult↗
PubMed1999

Real-time t(11;14) and t(14;18) PCR assays provide sensitive and quantitative assessments of minimal residual disease (MRD).

Non-Hodgkin's lymphoma (NHL) arises as a clonal transformation of normal B and T cell differentiation and is often characterized by a higher incidence of specific chromosomal translocations. We have developed real-time TaqMan PCR assays directed toward two of these tumor-associated DNA markers, the t(14;18)(q32;q21.3) at the major breakpoint region of the bcl-2 gene and the t(11;14)(q13;q32) at the bcl-1 major translocation cluster. During analysis of serial dilutions of t(14;18)-positive DNA, the t(14;18) real-time PCR was at least as sensitive as nested PCR and demonstrated enhanced quantitative potential. Moreover, in a blinded comparison of the t(14;18) real-time PCR and a clinically validated nested PCR protocol using 134 cell line and patient DNA samples, the real-time PCR detected the translocation in 30.0% more cases than nested PCR. Both the t(14;18) and t(11;14) real-time PCR assays were used to quantitate minimal residual disease (MRD) in an NHL clinical trial assessing the safety and efficacy of a tumor-purging protocol in autologous stem cell transplantation. The assays were also used to evaluate disease depletion in an ex vivo tumor spiking model in which normal peripheral blood was spiked with tumor cell lines and processed according to the clinical purging method. PCR data from both the clinical trial and the ex vivo model demonstrated a 4 to 6 log reduction in tumor cells during CD34+ and CD34+ Thy-1+ enrichment. Because the t(14;18) and t(11;14) real-time PCR assays are very sensitive, quantitative, rapid, and require no post-PCR manipulation, they may serve as practical alternatives to nested PCR.

Antigens, CD34↗
PubMed1998

Improved quantitation of minimal residual disease in multiple myeloma using real-time polymerase chain reaction and plasmid-DNA complementarity determining region III standards.

The complementarity determining region III of the rearranged immunoglobulin heavy chain gene has been the target for tumor-specific PCR assays for the detection and follow-up of B-cell malignancies. Previously, these assays have relied on gel-based end point data collection methods (i.e., band densitometry) and, thus, have provided at best a semiquantitative assessment of tumor levels. We show the development of a novel, real-time TaqMan PCR assay to quantitate residual multiple myeloma cells in clinical samples after high-dose chemotherapy and autologous stem cell transplantation. We provide evidence that real-time PCR is reproducible, sensitive, and quantitative. In a 40-replicate PCR experiment targeting the beta-actin gene, the coefficient of variation for threshold cycle data was 1.6%, whereas it increased to 13.6% and 31%, respectively, for end point fluorescence and gel densitometry. Moreover, in an experiment directly comparing standard curves obtained from band densitometry and threshold cycle data, the standard curve constructed from threshold cycle data had a multiple R2 value of 1.00 and demonstrated a dynamic range >4 logs, compared with the 2-log linear range of gel densitometry. Finally, we show that when a complementarity determining region III-specific PCR primer is used in conjunction with a consensus primer for the immunoglobulin heavy chain joining gene, plasmid DNA can be used as a readily available and effective substitute for clonal plasma-cell genomic DNA when preparing standards. By applying real-time PCR to the analysis of clinical samples, we are able to quantitate levels of tumor involvement with unparalleled reproducibility and statistical confidence. Real-time PCR technology may well provide the accuracy and reliability necessary for minimal residual disease detection to have real prognostic significance.

Base Sequence↗
PubMed1998

Collection, tumor contamination, and engraftment kinetics of highly purified hematopoietic progenitor cells to support high dose therapy in multiple myeloma.

Unfractionated peripheral blood stem cell (PBSC) grafts contain measurable quantities of myeloma cells and are therefore a potential source of relapse posttransplantation. In contrast, fluorescence-activated cell sorting (FACS)-sorted CD34+ Thy1+ Lin- peripheral blood cells are substantially enriched for stem cell activity, yet contain virtually no clonal myeloma cells. A study was performed in patients with symptomatic myeloma, who had received 12 months or less of preceding standard chemotherapy, to evaluate the feasibility of large scale purification of primitive hematopoietic stem cells in order to study engraftment kinetics posttransplantation and the degree of tumor cell contamination of this cell population, based on polymerase chain reaction (PCR) analysis for the patient-specific complementarity-determining region III (CDR III). PBSC were mobilized with high dose cyclophosphamide and granulocyte-macrophage colony-stimulating factor (GM-CSF). A combination of elutriation and chemical lysis was used to deplete PBSC collections of monocytes, granulocytes, erythrocytes, and platelets. Subsequently, CD34+ Thy1+ Lin- progenitor cells were purified with high speed cell sorting. Of the 10 evaluable patients, nine met the required minimum criteria of >/=7.2 x 10(5) cells/kg to support tandem transplants. After high dose melphalan (200 mg/m2) eight engrafted successfully, although granulocyte (absolute neutrophil count [ANC] >0.5 x 10(9)/L, 16 days) and platelet recovery (platelets > 50 x 10(9)/L, 39 days) was substantially delayed when compared with unmanipulated PBSC grafts; one patient required infusion of a reserve graft because of lack of evidence of engraftment by day +28. Three patients proceeded to a second graft with high dose melphalan and total body irradiation; two required infusion of a reserve graft and both died of infectious complications; one showed delayed, but complete, engraftment after this myeloablative regimen. Two of the nine evaluable patients attained a clinical complete remission (CR). The grafts from three patients were tested for tumor contamination and contained no detectable clonal myeloma cells. Larger quantities of purified cells may be required to resolve the problem of delayed engraftment.

Adult↗
PubMed1997

Novel anthelmintic metabolites from an Aspergillus species; the aspergillimides.

Two members of a novel class of anthelmintics, the aspergillimides, have been isolated from the Aspergillus strain IMI 337664. This novel fungus also produced two known and one structurally novel paraherquamide. This paper describes the fermentation, isolation, structure elucidation and anthelmintic activity of aspergillimide (VM55598, 1), 16-keto aspergillimide (SB202327, 2), and the paraherquamides VM54159 (3), SB203105 (4) and SB200437 (5). The aspergillimides are equivalent to paraherquamides which have lost both the dioxygenated 7-membered ring and the phenyl ring to which this is fused; gaining in their place a C8-keto group. SB203105 is the first example of a 4-substituted paraherquamide.

Alkaloids↗
PubMed1996

Leukemic burden in subpopulations of CD34+ cells isolated from the mobilized peripheral blood of alpha-interferon-resistant or -intolerant patients with chronic myeloid leukemia.

We attempted to determine the frequency of normal hematopoietic stem cells (HSC) and contaminating leukemic cells in mobilized peripheral blood (MPB) collected from chronic myeloid leukemia (CML) patients, intolerant of alpha-interferon or with interferon-resistant disease. A total of 14 MPB samples, six from patients in chronic phase (CP) and eight from patients in accelerated phase or blast crisis (AP/BC) were studied. Cytogenetic analysis of MPB collected from AP/BC patients showed that 100% of the cells were Ph+, whereas cells from four of five CP MPB were Ph-. By contrast, fluorescence in situ hybridization (FISH) analysis of CP MPB showed a mean frequency of 14.7% Ph+ cells, while AP/BC MPB contained 39.2% Ph+ cells. In an attempt to purify normal HSC, subpopulations of the MPB CD34+ cells were isolated based on expression of the Thy-1 antigen (CDw90). The mean Ph+ cell frequency as determined by FISH within the CD34+Thy-1+Lin- and CD34+Thy-1-Lin- populations from CP patients was 19.2% and 33.9%, respectively. In the AP/BC patients, levels of residual leukemic cells were significantly greater with mean Ph+ cell frequencies of 59.2% and 72.7% for the CD34+Thy-1+Lin- and CD34+Thy-1-Lin- fractions, respectively. The frequency of cobblestone area forming cells (CAFC) was used as a means of quantitating the numbers of functional HSC within these cell subpopulations. The mean CAFC frequency was 1 of 19 for the CD34+Thy-1+Lin- cells as compared with 1 of 133 for the Thy-1-fraction indicating a higher frequency of primitive progenitor cells in the Thy-1+ subpopulation. CD34+ cell subsets from two patients were also injected into SCID-hu bone assays to determine the in vivo behavior of these cell populations. After 8 weeks, multilineage donor engraftment was observed in these grafts. FISH analysis of the donor cells within the grafts showed that 55.3% and 60.0% of the cells were Ph+. We conclude that unfractionated MPB from this patient population is not leukemia-free and that the CD34+Thy-1+Lin- cell subpopulation, although predominantly enriched for normal HSC, still contains substantial numbers of residual leukemic cells.

Adolescent↗
PubMed1996

Production of metal dependent beta-lactamases by clinical strains of Bacteroides fragilis isolated before 1987.

Five imipenem resistant clinical isolates of Bacteroides fragilis isolated before 1987, were examined to determine if they produced metallo-beta-lactamases. The beta-lactamases produced by the clinical isolates all focused as doublet bands at pl 4.8/4.9, characteristic of the B. fragilis CfiA type metallo-beta-lactamase. Each enzyme had a similar substrate profile and were inhibited by EDTA and activated with zinc sulphate. The sequence of the metallo-beta-lactamase gene from B. fragilis ED262 was determined and confirmed to be a CfiA type beta-lactamase. Consequently, the five isolates examined probably produce a CfiA type beta-lactamase, suggesting that metallo-beta-lactamases were present before the widespread use of carbapenems.

Bacteroides fragilis↗
PubMed1995

Cytokine-mobilized peripheral blood CD34+Thy-1+Lin- human hematopoietic stem cells as target cells for transplantation-based gene therapy.

Gene-therapy of blood-borne disorders may be best achieved using hematopoietic stem cells (HSC) which have extensive self renewal potential as well as multilineage repopulating potential as a cellular target. The human HSC, which is CD34+Thy-1+Lin- has been isolated from fetal, adult bone marrow and cytokine-mobilized peripheral blood (MPB) (1-3). Results presented in this study show that the degree of mobilization of HSC into peripheral blood of cancer patients is highly variable and that the combined use of high dose chemotherapy and GM-CSF as a mobilization strategy is superior to the use of G-CSF with regard to the mobilization of true HSC. A multistep cell isolation procedure has been developed which utilizes high speed flow-cytometric cell sorting and allows the isolation of sufficient numbers of HSC from MPB to permit their use as an hematopoietic graft for clinical transplantation. Hematopoietic stem cells isolated from MPB are capable of self-renewal and differentiation into multiple hematopoietic lineages as shown by their behavior in both in vitro and in vivo assays. Mobilized PB mononuclear cells isolated from cancer patients are frequently contaminated with tumor cells. Using this cell isolation procedure, HSC preparations from patients with multiple myeloma have been created with greatly reduced tumor cell burdens. These CD34+Thy-1+Lin- cells are capable of being stably transduced at high efficiency (32-75%) by co-culture on a cell line producing recombinant retroviruses containing the neomycin-resistant gene. These HSC cell populations are likely ideal targets for hematopoietic cell-based gene therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Biological characterization of stem cell present in mobilized peripheral blood of CML patients.

Peripheral blood stem cell grafts are now frequently used for autologous transplantation of patients with malignancies. In this report we address the question of whether true long-term repopulating pluripotent hematopoietic stem cells (PHSC) are mobilized into peripheral blood and whether stem cells isolated from CML patients are depleted of Philadelphia chromosome positive cells. The presence of stem cells in mobilized peripheral blood (MPB) was examined by staining the CD34+Lineage- (Lin-) population for the expression of the Thy-1 antigen. The extent and kinetics of mobilization of CD34+Thy-1+ Lin- cells into peripheral blood were studied. In our analysis the percentage of these cells was found to vary widely depending on the day of leukapheresis and the individual patient. Fluorescence activated cell sorting (FACS) was used to isolate Thy-1 subsets from MPB which were analyzed for activity in in vitro long term cultures and in two in vivo models in which SCID-hu mice were implanted with human fetal bone or thymus grafts. The long term culture assay shows that the cells which express Thy-1 are enriched for cobblestone area forming activity (CAFC), an assay which can be used as a measure of detecting PBSC's in vitro. This CD34+Thy-1+ Lin- cell population was capable of producing both B and myeloid cells, and maintaining CD34+Lin- cells in these long term cultures. Moreover, the CD34+Thy-1+Lin- cell subset possessed a higher ability to engraft and to produce multilineage hematopoietic lineages in the SCID-hu bone assay and T cells in the SCID-hu thymus assay.(ABSTRACT TRUNCATED AT 250 WORDS)

Antigens, CD↗
PubMed1993

Thiotepa, busulfan, and cyclophosphamide: a new preparative regimen for autologous marrow or blood stem cell transplantation in high-risk multiple myeloma.

Forty patients with multiple myeloma received thiotepa (750 mg/m2), busulfan (10 mg/kg), and cyclophosphamide (120 mg/kg) (TBC) followed by autologous bone marrow or blood stem cell support. Granulocyte-Colony stimulating factor (G-CSF) was administered to accelerate hematopoietic recovery. Sixty-five percent of all patients responded to this treatment. Eighty-eight percent of patients transplanted in partial remission had a further reduction of the myeloma and 53% achieved a complete remission. Forty-eight percent of patients with refractory myeloma responded. All responding patients transplanted during partial remission or with primary refractory myeloma remain free of progression for a period of 4 to 24 months post-transplant, but the remission duration of patients treated in refractory relapse was short (4 months). Five of 24 patients transplanted with marrow and none of 16 receiving blood stem cells died of treatment-related complications. Use of blood stem cells resulted in more rapid granulocyte and platelet recovery. We conclude that TBC is an effective, relatively well tolerated, preparative regimen for patients with multiple myeloma.

Adult↗
PubMed1993

Molecular approaches to the diagnosis and treatment of cancer.

We have used autologous bone marrow transplantation (ABMT) as a setting to develop the genetic therapy of cancer in hematopoietic neoplasms based on the use of the bone marrow as a conduit through which to introduce regulatory molecules into the patient. This has involved three developmental phases: 1) learning how to develop genetic modification techniques; 2) learning how to develop in vivo selection techniques for the genetically modified cells; and 3) developing molecular vectors for modification of hematopoietic cells for therapy of cancer. These programs will be summarized in terms of their progress at the conference.

Bone Marrow Transplantation↗
PubMed1993

Genetic therapy of human neoplastic disease.

Molecular biology has provided clinical investigators and basic scientists with the tools to identify those changes present within neoplastic hematopoietic and epithelial cells that lead to the evolution of unregulated patterns of cell growth. This information has made possible the development of therapy that involves genetic modification of either the normal hematopoietic cells (for chemoprotection), or the tumor cells themselves to suppress the growth of these cells. This article will summarize the clinical and laboratory data that is evolving in this area.

Animals↗