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Biomedical subjects

Christopher Morris

Publications and source records attributed to Christopher Morris.

29 records · Page 2Linked to original sources
PubMed2002

Thrombogenic activity of doxorubicin in myeloma patients receiving thalidomide: implications for therapy.

Ten percent of newly diagnosed myeloma patients treated with any type of chemotherapy develop deep venous thrombosis (DVT). Thalidomide has proven activity in refractory multiple myeloma (MM), and although single-agent thalidomide has minimal prothrombogenic activity, its combination with cytotoxic chemotherapy is associated with a significantly increased risk of DVT. We analyzed the incidence of DVT in 232 MM patients who received a combination of chemotherapy and thalidomide on 2 protocols that differed only by the inclusion of doxorubicin in one. DT-PACE (dexamethasone/thalidomide/cisplatin/doxorubicin/cyclophosphamide/etoposide) was offered to patients with preceding standard dose therapy, but no prior autotransplantation, while DCEP-T (dexamethasone/cyclophosphamide/etoposide/cisplatin/thalidomide) was administered for relapse after transplantation. If there were signs or symptoms suggestive of DVT, patients received additional investigations, including Doppler ultrasonography, followed by venography if indicated. Only patients on DT-PACE but not DCEP-T experienced an increased incidence of DVT. A statistical association between the incidence of DVT and combination chemotherapy including doxorubicin (P =.02) was observed; this association was confirmed on multivariate analysis. MM patients treated with thalidomide and doxorubicin have a high risk of developing DVT.

Adult↗
PubMed2002

Global gene expression profiling of multiple myeloma, monoclonal gammopathy of undetermined significance, and normal bone marrow plasma cells.

Bone marrow plasma cells (PCs) from 74 patients with newly diagnosed multiple myeloma (MM), 5 with monoclonal gammopathy of undetermined significance (MGUS), and 31 healthy volunteers (normal PCs) were purified by CD138(+) selection. Gene expression of purified PCs and 7 MM cell lines were profiled using high-density oligonucleotide microarrays interrogating about 6800 genes. On hierarchical clustering analysis, normal and MM PCs were differentiated and 4 distinct subgroups of MM (MM1, MM2, MM3, and MM4) were identified. The expression pattern of MM1 was similar to normal PCs and MGUS, whereas MM4 was similar to MM cell lines. Clinical parameters linked to poor prognosis, abnormal karyotype (P =.002) and high serum beta(2)-microglobulin levels (P =.0005), were most prevalent in MM4. Also, genes involved in DNA metabolism and cell cycle control were overexpressed in a comparison of MM1 and MM4. In addition, using chi(2) and Wilcoxon rank sum tests, 120 novel candidate disease genes were identified that discriminate normal and malignant PCs (P <.0001); many are involved in adhesion, apoptosis, cell cycle, drug resistance, growth arrest, oncogenesis, signaling, and transcription. A total of 156 genes, including FGFR3 and CCND1, exhibited highly elevated ("spiked") expression in at least 4 of the 74 MM cases (range, 4-25 spikes). Elevated expression of these 2 genes was caused by the translocation t(4;14)(p16;q32) or t(11;14)(q13;q32). Thus, novel candidate MM disease genes have been identified using gene expression profiling and this profiling has led to the development of a gene-based classification system for MM.

Bone Marrow Cells↗
PubMed2002

Improved outcome of allogeneic transplantation in high-risk multiple myeloma patients after nonmyeloablative conditioning.

PURPOSE: We present our experience with relapsed and recently diagnosed patients with high-risk multiple myeloma (MM) receiving immunosuppressive, nonmyeloablative melphalan (MEL)-based conditioning regimens (mini-allograft). PATIENTS AND METHODS: Thirty-one MM patients received allografts from HLA-matched siblings (n = 25) or unrelated donors (n = 6) using a mini-allograft. Seventeen had progressive disease (PD) and 14 had responsive disease (RD) (six with primary RD and eight with responsive relapse). Thirty patients had received one (n = 13) or two or more (n = 17) prior autologous transplantations (ATs). Median age was 56 years (range, 38 to 69 years). Twenty-one patients had chromosome 13 abnormality. Two patients were hemodialysis dependent. Blood and bone marrow grafts were administered to 28 and three patients, respectively. Donor lymphocyte infusions were given to 18 patients either to attain full donor chimerism (n = 6) or to eradicate residual disease (n = 12). RESULTS: By day 100, 25 (89%) of 28 patients were full donor chimeras, one was a mixed chimera, and two had autologous reconstitution. Acute graft-versus-host disease (GVHD) developed in 18 patients (58%), and 10 progressed to chronic GVHD (limited in six and extensive in four). At a median follow-up of 6 months, 19 (61%) of 31 patients achieved complete/near complete remission. Twelve patients (39%) have died: three of PD, three of early treatment-related mortality (TRM) (before day 100), and six of late TRM. Median overall survival (OS) was 15 months. At 1 year, there was a significantly longer event-free survival (86% v 31%, P =.01) and OS (86% v 48%, P =.04) when a mini-allograft was performed after one versus two or more prior ATs, respectively. When compared with historical MM controls (n = 93) receiving conventional allografts, early TRM was significantly lower (10% v 29%, P =.03), and OS at 1 year was better (71% v 45%; P =.08) in the mini-allograft MM patients. CONCLUSION: Mini-allograft induced excellent disease control in MM patients with high-risk disease, but is still associated with a significant GVHD.

Adult↗
PubMed2002

Selective nicotinic receptor consequences in APP(SWE) transgenic mice.

The nicotinic (nAChRs) and muscarinic (mAChRs) acetylcholine receptors and acetylcholinesterase (AChE) activity were studied in the brains of APP(SWE) transgenic mice (Tg+) and age-matched nontransgenic controls (Tg-) that were between 4 and 19 months of age. A significant increase in the binding of 125I-labeled alpha-bungarotoxin (alpha7 nAChRs) was observed in most brain regions analyzed in 4-month-old Tg+ mice, preceding learning and memory impairments and amyloid-beta (Abeta) pathology. The enhanced alpha7 receptor binding was still detectable at 17-19 months of age. Increase in [3H]cytisine binding (alpha4beta2 nAChRs) was measured at 17-19 months of age in Tg+ mice, at the same age when the animals showed heavy Abeta pathology. No significant changes in [3H]pirenzepine (M1 mAChRs) or [3H]AFDX 384 (M2 mAChRs) binding sites were found at any age studied. The upregulation of the nAChRs probably reflects compensatory mechanisms in response to Abeta burden in the brains of Tg+ mice.

Acetylcholinesterase↗
PubMed2002

Myeloma of the central nervous system: association with high-risk chromosomal abnormalities, plasmablastic morphology and extramedullary manifestations.

Involvement of the central nervous system (CNS) by multiple myeloma, as defined by the detection of malignant plasma cells in the cerebrospinal fluid in the presence of suggestive symptoms, is considered extremely rare. We report on the characteristics of 18 such patients diagnosed and treated at the University of Arkansas over the last 10 years for an overall incidence of approximately 1%. Their evaluation revealed association of CNS involvement with unfavourable cytogenetic abnormalities (especially translocations and deletion of the chromosome 13), high tumour mass, plasmablastic morphology, additional extramedullary myeloma manifestations and circulating plasma cells. The presence of these features should alert clinicians to the possibility of CNS involvement. The outcome of these patients was extremely poor despite the use of aggressive local and systemic treatment including autologous stem cell transplants. Given this universally poor prognosis, the application of allogeneic transplants should be studied in this clinical setting.

Adult↗
PubMed2002

Both hypodiploidy and deletion of chromosome 13 independently confer poor prognosis in multiple myeloma.

Complete or partial deletion of chromosome 13 or translocations involving 13q (delta13) by conventional cytogenetic analysis confers a poor prognosis in multiple myeloma (MM) patients, even with timely application of tandem autologous transplants. It was recently suggested that the prognostic significance of delta13 is related to its frequent association with hypodiploidy but by itself does not have a poor prognostic significance. We therefore analysed our experience in 1475 consecutive MM patients in whom we intended treatment with tandem transplants after a melphalan-based conditioning regimen. Patients with abnormal cytogenetic analysis were grouped into hypodiploid/hypotetraploid, pseudodiploid and hyperdiploid groups, according to their modal chromosome number. Their event-free and overall survival were compared with those of patients with a normalkaryotype. Both hypodiploidy and delta13 were found to independently confer poor prognosis in MM patients. Furthermore, these parameters in combination with easily obtained pretransplant levels of beta-2 microglobulin and albumin define three groups of MM patients with clearly distinct outcomes.

Biomarkers, Tumor↗
PubMed2002

Variations in the orthotic management of cerebral palsy.

OBJECTIVE: Anecdotal reports that children with cerebral palsy were provided different orthoses in two adjacent UK health districts were investigated using an observational comparative case study. METHOD: The populations were compared using an epidemiological register of children with cerebral palsy, which confirmed that a comparable health service response could be expected. Merging data from the register with the orthotic patient database facilitated comparison of the orthoses prescribed in each district. A survey questionnaire was used to gather the perceptions of clinicians in both districts to understand how each team decides which orthosis to prescribe. RESULTS: There was considerable variation in the types of orthoses prescribed between districts, and particularly of ankle foot orthoses. Survey respondents from the same profession described having the same roles, although clinicians expressed different responsibilities for initiating and sanctioning orthotic prescriptions in their district programmes. The survey also suggested that most clinicians were uncertain when prescribing orthoses, and clinical practice was therefore largely determined by professional preference. CONCLUSION: Defining the spectrum of activity limitation in geographically defined populations would enhance health services research and assist in the development of trials using different interventions to reduce those limitations.

Cerebral Palsy↗
PubMed2002

ABO mismatch may affect engraftment in multiple myeloma patients receiving nonmyeloablative conditioning.

BACKGROUND: Blood group incompatibility does not appear to affect the overall outcome in patients undergoing myeloablative conditioning before allogeneic BMT. Data on ABO-mismatched transplantation in the nonmyeloablative setting are limited. STUDY DESIGN AND METHODS: A retrospective analysis of the effects of ABO mismatches in multiple myeloma patients who received a nonmyeloablative conditioning regimen was conducted. RESULTS: Three of 27 patients received a minor ABO-mismatched graft, all with evidence of hemolysis before converting to donor ABO group on Days 10, 15, and 6. Six patients received a major ABO-mismatched graft; of these, three developed GVHD of more than grade 2 and subsequently converted to the ABO blood group of the donor on Days 38, 33, and 43. Of the three patients without GVHD, one rejected the allograft and had autologous reconstitution. One remained a mixed chimera to Day 100 despite three donor lymphocyte infusions, and one developed pure RBC aplasia. None of the ABO-matched patients rejected the graft, whether they developed GVHD or not. RBC transfusions were significantly higher in the major and minor ABO-mismatched patients than in the ABO-matched patients, with medians of 12 units (range, 2-35), 13 units (range, 5-18), and 4 units (range, 2-15), respectively (p = 0.02). ABO-matched patients had a similar incidence of GVHD, with 5 of 9 ABO-mismatched patients (56%) having more than grade 2 versus 10 of 18 (56%). Four of 9 ABO-mismatched patients (44%) were mixed chimeras up to Day 100 versus 2 of 18 ABO-matched patients (11%), and the difference was significant (p = 0.01). CONCLUSION: Patients with ABO mismatch had problems with engraftment, including graft rejection, pure RBC aplasia, and mixed-lineage chimerism. RBC transfusions were significantly higher in the ABO-mismatched recipients. GVHD may play a role in engraftment, possibly by facilitating the disappearance of native ABO antibodies via graft-versus-plasma cell effect. A prospective study to evaluate the effects of ABO mismatch on engraftment in the nonmyeloablative setting is needed.

ABO Blood-Group System↗
PubMed2002

Thalidomide paradoxical effect on concomitant multiple myeloma and myelodysplasia.

We present five cases of concomitant relapsed multiple myeloma and therapy related myelodysplasia (t-MDS). After treatment with thalidomide marked anti-myeloma activity was observed, but it was associated with rapid progression of the MDS clone to acute myeloid leukemia (AML). This paradoxical effect of thalidomide is concerning because there is increasing use of thalidomide in relapsed, heavily treated multiple myeloma patients who already have a higher propensity to develop MDS. The leukemic transformation in our cases most probably reflects the natural progression of MDS, though it clearly demonstrates that thalidomide is ineffective in controlling blast proliferation in t-MDS. More concerning, however, is the possibility that thalidomide, while suppressing the myeloma clone, eliminates inhibitory signals and subsequently stimulates the proliferation of the leukemic clone. The use of thalidomide should be carefully assessed in relapsed multiple myeloma patients with clinical and cytogenetic evidence of t-MDS.

Acute Disease↗
PubMed2002

Heat shock inhibits tnf-induced ICAM-1 expression in human endothelial cells via I kappa kinase inhibition.

The pulmonary vascular endothelium plays a critical role in lung inflammation. As a result of proinflammatory cytokine expression, adhesion molecules are upregulated on the surface of the endothelial cells. Adhesion molecules facilitate recruitment of leukocytes and thus, have been targeted for potential anti-inflammatory strategies. Prior induction of the stress response through thermal stimulation, or heat shock, alters proinflammatory gene expression by attenuating NF-kappaB signaling. As intercellular adhesion molecule-(ICAM) 1 expression is, in part, NF-kappaB-dependent, we hypothesized that heat shock would inhibit ICAM-1 expression. Heat shocking endothelial cells resulted in heat shock protein (HSP) expression as measured by HSP-70 induction, and decreased TNF-alpha-induced ICAM-1 expression in a manner that appeared to be transcriptionally mediated. Following heat shock, decreased TNF-alpha-induced NF-kappaB activation was observed and was associated with preservation of IkappaB-alpha and a decrease in phosphorylated IkappaB-alpha that correlated to inhibition of I kappa kinase (IKK) activity. Interestingly, exposing respiratory epithelial cells to heat shock, which results in NF-kappaB inhibition, did not affect TNF-induced ICAM-1 expression. We conclude that heat shock decreases endothelial cell ICAM-1 expression via inhibition of IKK activity.

Cell Membrane↗