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Biomedical subjects

Douglas Joshua

Publications and source records attributed to Douglas Joshua.

6 recordsLinked to original sources

The use of thalidomide in myeloma therapy as an effective anticancer drug.

Thalidomide and its immunomodulatory derivatives have provided the most significant advance in the therapy of myeloma since the introduction of high dose chemotherapy followed by stem cell transplantation nearly 20 years ago. The mechanism of action of thalidomide is complex and involves many aspects of malignant plasma cell growth and bone marrow stromal cell microenvironment interaction. Thalidomide was first used because of its anti-angiogenic properties, however it is the immunomodulatory actions that involve increasing host tumour-specific immunosurveillance by both T cell and natural killer cells which may be the most important mode of action.

Animals↗

A randomized trial of high-versus conventional-dose cytarabine in consolidation chemotherapy for adult de novo acute myeloid leukemia in first remission after induction therapy containing high-dose cytarabine.

The value of administering sequential courses of chemotherapy containing high-dose cytarabine in both induction and consolidation therapy for acute myeloid leukemia (AML) has not been assessed in a prospective randomized trial. Two hundred ninety-two AML patients aged 15 to 60 years were enrolled in the Australasian Leukaemia and Lymphoma Group (ALLG) AML trial number 7 (M7) protocol to evaluate this question. All received induction therapy with the ICE protocol (idarubicin 9 mg/m2 x 3; cytarabine 3 g/m2 twice a day on days 1, 3, 5, 7; etoposide 75 mg/m2 x 7). Complete remission was achieved in 234 (80%) patients. Two hundred two patients in remission were then randomized to either a further identical cycle of ICE or 2 attenuated courses (cytarabine 100 mg/m2 daily x 5, idarubicin x 2, etoposide x 5 [IcE]). ICE consolidation therapy was more toxic than IcE, however, the treatment-related death rate was not significantly different. There was no difference between the 2 consolidation arms for relapse-free survival at 3 years (49% for ICE vs 46% for IcE; P = .66), survival following randomization (61% vs 62%; P = .91), or the cumulative incidence of relapse (43% vs 51%; P = .31), and there was no difference within cytogenetic risk groups. Intensive induction chemotherapy incorporating high-dose cytarabine results in high complete remission rates, but further intensive consolidation treatment does not appear to confer additional benefit.

Acute Disease↗

Myeloma management guidelines: a consensus report from the Scientific Advisors of the International Myeloma Foundation.

These consensus guidelines have been compiled with input from the Scientific Advisors of the International Myeloma Foundation. Their production involved several steps including: A 3-day Scientific Advisors meeting, during which each specific area was presented and discussed (May 2002). Review of key literature, especially randomized study results, but also Medline, Internet, Cochrane database searches, and prior guidelines (Br J Haematol 115: 522-540, 2001). Feedback from patients participating in the International Myeloma Foundation, patient programs. These guidelines encompass both the published literature and expert opinions. Recommendations based upon expert opinions are identified as such. The intent is for the guidelines to be international in scope, plus provide recommendations for both clinical practice and research approaches. 'Consensus' reflects general, although not necessarily unanimous, agreement. Details are discussed as appropriate. For convenience, the recommendations are divided into: 1. Diagnostic criteria. 2. Staging and prognostic factors. 3. Frontline therapy. 4. High-dose therapy and transplant. 5. Maintenance therapy. 6. Supportive care and management of specific complications. 7. Novel therapies and new technologies.

Anemia↗

The biology and cytogenetics of multiple myeloma.

Despite the advances in our knowledge of myeloma cell biology, our understanding of myeloma pathogenesis is still incomplete. In this review, we present a summary of the cellular and molecular aspects of B-cell development and immunoglobulin (lg) gene rearrangement which have been important in defining the characteristics of the myeloma plasma cell (MPC). The PMC has undergone variable gene recombination, somatic hypermutation and isotype switching, and is therefore at a postgerminal center stage of development. The finding of preswitch clonal cells and isotype variants have raised interesting questions about the cell of origin of myeloma, for which no conclusive data is as yet available. However much information has been obtained about the chromosomal and genetic aberrations in myeloma, including monosomy 13, Ig heavy chain (IgH) switch region translocations, numerical abnormalities and a multitude of heterogeneous changes. A variety of techniques have been developed to overcome the insensitivity of conventional karyotyping, utilizing molecular cytogenetic strategies ranging from the delineation of precise loci by fluorescent in situ hybridization, a more "global" assessment of the genome by multicolor spectral karyotyping, to the quantitation of chromosomal material of specific origin by comparative genomic hybridization. Whether the abnormalities detected represent oncogenic insults, are involved in disease progression or are simply "by-products" of genetic instability is still unclear. For IgH translocations, the role of candidate genes such as Cyclin D1 and FGFR3 has been studied extensively by quantitating their expression and assessment of their oncogenicity (e.g. for FGFR3) in animal models. The significance of other aberrations such as c-myc, ras and p53 has also been investigated. With the advent of oligonucleotide microarrays, the expression of thousands of genes can be efficiently examined. So far, this approach seems promising in defining subgroups of different disease behavior, and may highlight specific genes and molecular mechanisms which are important in myeloma pathogenesis.

Animals↗