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Biomedical subjects

J Matthews

Publications and source records attributed to J Matthews.

At least 55 records · Page 3Linked to original sources
PubMed1999

Tumour necrosis factor polymorphisms and susceptibility to follicular lymphoma.

Follicular lymphoma is characterized in 85% of patients by the presence of a t(14;18) chromosomal translocation that results in overproduction of BCL2. In this study the distribution of high and low expressing TNF alleles at the TNF (-308) and LTalpha (+252) polymorphic sites in 121 patients with follicular lymphoma and 88 control individuals has been analysed. A reduction in high expressing haplotypes in patients compared to normal controls was found (P = 0.055), with no significant difference observed in response rate or overall survival between patients with high or low expressing haplotypes. These results suggest that the TNF locus, or an adjacent locus within the MHC region, is an important genetic risk factor in this disease.

Adult↗
PubMed1999

Factors affecting the outcome of allogeneic bone marrow transplantation for adult patients with refractory or relapsed acute leukaemia.

We evaluated the outcome of allogeneic bone marrow transplantation (BMT) for advanced acute myeloid leukaemia (AML) and acute lymphoblastic leukaemia (ALL) in 383 adult patients in nine Australian adult BMT centres between 1981 and 1997. The median overall survival for the group was 4.8 months, with an estimated 5-year survival of 18%. 28% of patients died of transplant-related toxicities within the first 100 d. Progressive disease was responsible for 48% of deaths. Multi-factor analysis demonstrated that AML (v ALL), disease status (second complete remission [CR2] v others), age (< 40 years) and duration of prior first complete remission (CR1) (> 6 months) were pre-transplant variables significantly associated with improved survival. Acute graft-versus-host disease (GVHD) of any grade reduced the rate of relapse in both AML and ALL, but only grades I-II were associated with improved survival. Both limited and extensive chronic GVHD were associated with increased survival. Only patients with AML in untreated first relapse or CR2, with a duration of CR1 > 6 months, or patients with T ALL, had a 5-year survival > 20%. Transplants for AML in induction failure or pre-B ALL in untreated first relapse or CR2 had an intermediate outcome, with 5-year survival of 10-20%. A 5-year survival of < 10% was observed for patients transplanted for ALL in induction failure or for pre-B ALL or AML in refractory first relapse or beyond CR2. These results suggest that for most adult patients with advanced acute leukaemia an allograft offers only a small chance of cure.

Adolescent↗
PubMed1999

Impact of a dedicated trauma service on the quality and cost of care provided to injured patients at an urban teaching hospital.

BACKGROUND: To determine the impact of a dedicated trauma service on cost and quality of care in an urban teaching hospital, a before-and-after study was designed. The key elements of the trauma service were dedicated in-house trauma attending surgeons and residents, and continuity and integration of trauma care. METHODS: Injury Severity Scores and probabilities of survival for each patient were calculated from the hospital International Classification of Diseases, Ninth Revision, codes, and individual patient costs were estimated from charges using the Medicare Cost Report. RESULTS: The trauma service resulted in a significant increase in the severity of injuries. There was a highly significant (p<0.001) increase in the mean probability of death (from 0.16 to 0.21). There was no change in actual mortality. Although the mean cost of care increased by 16.6%, there were small reductions in the cost of care of the most severely injured patients. CONCLUSION: A dedicated trauma service has a positive impact on the quality of care.

Adult↗
PubMed1999

A cell line-based neutralization assay for primary human immunodeficiency virus type 1 isolates that use either the CCR5 or the CXCR4 coreceptor.

We describe here a cell line-based assay for the evaluation of human immunodeficiency virus type 1 (HIV-1) neutralization. The assay is based on CEM.NKR cells, transfected to express the HIV-1 coreceptor CCR5 to supplement the endogenous expression of CD4 and the CXCR4 coreceptor. The resulting CEM.NKR-CCR5 cells efficiently replicate primary HIV-1 isolates of both R5 and X4 phenotypes. A comparison of the CEM.NKR-CCR5 cells with mitogen-activated peripheral blood mononuclear cells (PBMC) in neutralization assays with sera from HIV-1-infected individuals or specific anti-HIV-1 monoclonal antibodies shows that the sensitivity of HIV-1 neutralization is similar in the two cell types. The CEM.NKR-CCR5 cell assay, however, is more convenient to perform and eliminates the donor-to-donor variation in HIV-1 replication efficiency, which is one of the principal drawbacks of the PBMC-based neutralization assay. We suggest that this new assay is suitable for the general measurement of HIV-1 neutralization by antibodies.

CD4 Antigens↗
PubMed1999

The CC-chemokine RANTES increases the attachment of human immunodeficiency virus type 1 to target cells via glycosaminoglycans and also activates a signal transduction pathway that enhances viral infectivity.

We have studied the mechanisms by which the CC-chemokine RANTES can enhance the infectivities of human immunodeficiency virus type 1 (HIV-1) and other enveloped viruses, when present at concentrations in excess of 500 ng/ml in vitro. Understanding the underlying mechanisms might throw light on fundamental processes of viral infection, in particular for HIV-1. Our principal findings are twofold: firstly, that oligomers of RANTES can cross-link enveloped viruses, including HIV-1, to cells via glycosaminoglycans (GAGs) present on the membranes of both virions and cells; secondly, that oligomers of RANTES interact with cell-surface GAGs to transduce a herbimycin A-sensitive signal which, over a period of several hours, renders the cells more permissive to infection by several viruses, including HIV-1. The enhancement mechanisms require that RANTES oligomerize either in solution or following binding to GAGs, since no viral infectivity enhancement is observed with a mutant form of the RANTES molecule that contains a single-amino-acid change (glutamic acid to serine at position 66) which abrogates oligomerization.

Animals↗
PubMed1999

Patterns of outcome following recurrence after myeloablative therapy with autologous bone marrow transplantation for follicular lymphoma.

PURPOSE: To assess the patterns of recurrence, management, and survival following recurrence after myeloablative therapy with autologous bone marrow transplantation (ABMT) in patients with follicular lymphoma (FL). PATIENTS AND METHODS: Between June 1985 and October 1995, 99 patients with FL received cyclophosphamide and total-body irradiation with ABMT as consolidation of second or subsequent remission. RESULTS: Median length of follow-up was 5 1/2 years, and 33 patients developed recurrent lymphoma a median of 14 months after ABMT. In 26 patients, the recurrence was overt; in seven, it was detected on surveillance investigation. Twenty-six patients presented with recurrence at previous sites of disease. Twenty-two patients (67%) had FL at the time of recurrence; in 11 (33%), there was evidence of transformation to diffuse large B-cell lymphoma. Eight patients were managed expectantly; five were alive 21 to 53 months later. Twenty-five patients have required treatment to date; eight remained alive 6 months to 10 years later, and five were in remission. The Kaplan-Meier estimate of patients alive 5 years after recurrence is 45% (95% confidence interval, 27% to 62%). In univariate and multivariate analyses, survival after recurrence and overall survival after diagnosis were similar to those of a historical control group who received conventional treatment, before the introduction of myeloablative therapy (adjusted hazard ratio [HR], 1.56, P = .3, and HR, 1.34, P = .4, respectively). CONCLUSION: The survival pattern of patients with FL following recurrence after myeloablative therapy and ABMT suggests that this treatment does not compromise outcome in patients in whom it fails, reflecting the survival pattern of the disease when treated conventionally.

Adult↗
PubMed1999

A 15-month evaluation of the effects of repeated subgingival minocycline in chronic adult periodontitis.

BACKGROUND: A double-blind, randomized, parallel, comparative study was designed to evaluate the long-term safety and efficacy of subgingivally administered minocycline ointment versus a vehicle control. METHODS: One hundred four patients (104) with moderate to severe adult periodontitis (34 to 64 years of age; mean 46 years) were enrolled in the study. Following scaling and root planing, patients were randomized to receive either 2% minocycline ointment or a matched vehicle control. Study medication was administered directly into the periodontal pocket with a specially designed, graduated, disposable applicator at baseline; week 2; and at months 1, 3, 6, 9, and 12. Scaling and root planing was repeated at months 6 and 12. Standard clinical variables (including probing depth and attachment level) were evaluated at baseline and at months 1, 3, 6, 9, 12, and 15. Microbiological sampling using DNA probes was done at baseline; at week 2; and at months 1, 3, 6, 9, 12, and 15. RESULTS: Both treatment groups showed significant and clinically relevant reductions in the numbers of each of the 7 microorganisms measured during the entire 15-month study period. When differences were detected, sites treated with minocycline ointment always produced statistically significantly greater reductions than sites which received the vehicle control. For initial pockets > or =5 mm, a mean reduction in probing depth of 1.9 mm was seen in the test sites, versus 1.2 mm in the control sites. Sites with a baseline probing depth > or =7 mm and bleeding index >2 showed an average of 2.5 mm reduction with minocycline versus 1.5 mm with the vehicle. Gains in attachment (0.9 mm and 1.1 mm) were observed in minocycline-treated sites, with baseline probing depth > or =5 mm and > or =7 mm, respectively, compared with 0.5 mm and 0.7 mm gain at control sites. Subgingival administration of minocycline ointment was well tolerated. CONCLUSIONS: Overall, the results demonstrate that repeated subgingival administration of minocycline ointment in the treatment of adult periodontitis is safe and leads to significant adjunctive improvement after subgingival instrumentation in both clinical and microbiologic variables over a 15-month period.

Adult↗
PubMed1998

High-dose therapy with autologous haematopoietic support in patients with transformed follicular lymphoma: a study of 27 patients from a single centre.

BACKGROUND: The prognosis of patients with transformed follicular lymphoma (FL-t) is poor. The use of high-dose therapy (HDT) with autologous haematopoietic support was therefore evaluated as consolidation of remission. PATIENTS AND METHODS: Twenty-seven patients received high-dose cyclophosphamide and total body irradiation (cyclo + TBI) with autologous bone marrow (BM; n = 24) or peripheral blood progenitor cell support (PBPC; n = 3). BM was treated in vitro with anti-B cell antibodies and complement. Nineteen of 27 patients were treated in first stable remission following transformation. Eight other patients with a history of transformation were treated following a subsequent recurrence of follicular lymphoma (FL). RESULTS: With a median follow-up of 2.4 years, 14 of 27 patients remain alive and in remission; five are alive and free of disease at more than four years. The median survival is 8.5 years. There were two 'early' treatment-related deaths of respiratory failure, and two 'late' deaths of myelodysplastic syndrome (MDS) in remission of lymphoma at 2.8 and 8.5 years. Seven of nine patients having had a recurrence underwent re-biopsy. In two, histology revealed FL, in five, transformed follicular lymphoma. One of the patients with recurrent FL is alive without further therapy, and two of five patients with recurrent FL-t are alive and in remission after further chemotherapy. CONCLUSIONS: It is appropriate to consider HDT for younger patients with FL-t in remission. Repeat biopsy should be considered for patients with recurrent disease. There is a risk of late MDS in patients undergoing this treatment.

Adult↗
PubMed1997

Salvage radiotherapy for Hodgkin's disease following chemotherapy failure.

PURPOSE: This study aims to: 1) assess failure-free survival (FFS), overall survival (OS), and failure pattern after salvage radiotherapy (SRT) for patients with Hodgkin's disease (HD) who fail chemotherapy (CT); 2) identify patients suitable for SRT as an alternative to more aggressive salvage regimens. METHODS AND MATERIALS: Between 1978 and 1992, 52 patients with relapsed/refractory HD following 26 CT received SRT at the Peter MacCallum Cancer Institute. Patient characteristics at diagnosis were: median age (range 12-63); male-31, female-21; Stage I-4, II-16, III-25, or IV-7. Prior to SRT 27 patients had received the equivalent of both MOPP and ABV(D). The duration of initial complete response (CR) from CT was greater than 12 months in 22 patients. SRT (dose 34-42 Gy) was given to active disease sites. RESULTS: Five-year FFS and OS rates following SRT were 26 and 57%, respectively. Five-year FFS and OS rates of 36 and 75%, respectively, were achieved in patients who relapsed in supradiaphragmatic nodal sites without B symptoms; in a subset of patients with initial Stage I-II disease the FFS and OS rates were 50 and 86%, respectively. On multivariate analysis significant factors for FFS were B symptoms at the time of SRT (p = 0.003), extranodal involvement (p = 0.011) and histology (p = 0.018). For OS significant factors were B symptoms (p = 0.0007), age (p = 0.014) and number of prior CT regimens (p = 0.03). CONCLUSION: The relatively poor results of SRT in terms of FFS justify the use of alternative salvage strategies for most patients with Hodgkin's disease who fail CT. However, SRT offers a low morbidity, potentially curative option for a subset of patients. Our data suggest that patients most suitable for SRT are those with relapse in supradiaphragmatic nodal sites and no B symptoms.

Adolescent↗
PubMed1997

Cloning, in vitro expression, and functional characterization of a novel human CC chemokine of the monocyte chemotactic protein (MCP) family (MCP-4) that binds and signals through the CC chemokine receptor 2B.

Here we describe the characterization of a novel human CC chemokine, tentatively named monocyte chemotactic protein (MCP-4). This chemokine was detected by random sequencing of expressed sequence tags in cDNA libraries. The full-length cDNA revealed an open reading frame for a 98-amino acid residue protein, and a sequence alignment with known CC chemokines showed high levels of similarity (59-62%) with MCP-1, MCP-3, and eotaxin. MCP-4 cDNA was cloned into Drosophila S2 cells, and the mature protein (residues 24-98) was purified from the conditioned medium. Recombinant MCP-4 induced a potent chemotactic response (EC50 = 2.88 +/- 0.15 nM) and a transient rise in cytosolic calcium concentration in fresh human peripheral blood monocytes but not in neutrophils. Binding studies in monocytes showed that MCP-4 and MCP-3 were very potent in displacing high affinity binding of 125I-MCP-1 (IC50 for MCP-4, MCP-3, and unlabeled MCP-1 of 2.1 +/- 1.4, 0.85-1.6, and 0.7 +/- 0.2 nM respectively), suggesting that all three chemokines interact with the CC chemokine receptor-2 (MCP-1 receptor). This was confirmed in binding studies with Chinese hamster ovary cells, stably transfected with the CC chemokine 2B receptor. Northern blot analysis in extracts of normal human tissues showed expression of mRNA for MCP-4 in small intestine, thymus, and colon, but the level of protein expression was too low to be detected in Western blot analysis. However, expression of MCP-4 protein was demonstrated by immunohistochemistry in human atherosclerotic lesion and found to be associated with endothelial cells and macrophages.

Amino Acid Sequence↗
PubMed1997

A volumetric study of measurements and calculations of lung density corrections for 6 and 18 MV photons.

PURPOSE: For treatment of lung cancer, dose heterogeneity corrections and subsequent prescription alteration remain controversial. Previous dosimetry studies based on slab geometry with a single beam geometry do not represent the clinical situation. A circumscribed tumor within lung poses a more complex problem. Energy choice also remains controversial. METHODS AND MATERIALS: An anthropomorphic phantom was modified by replacing lung cylinders (2.5 and 5.0 cm diameters by 5.0 cm length) with muscle-equivalent cylinders. The phantom was scanned on a CT simulator. Gross, clinical, and planning target volumes (GTV, CTV, PTV1 including tumor and regional nodes, PTV2 including tumor only) were designated slice-by-slice. Three-dimensional planning was performed with large fields (AP/PA/RPO) covering PTV1 and boost fields optimized for each PTV2, for 6 and 18 MV photons. Homogeneous, Ratio-Tissue-Air-Ratio (RTAR), and convolution-adapted RTAR (CARTAR) calculation algorithms were tested. Film was placed between phantom slices at the "tumor" levels. The phantom was irradiated with monitor units corresponding to homogeneous calculations, based on a homogeneous prescription. Measured and calculated doses were compared by isodoses and dose volume histograms. Ionization chambers and TLDs were also used for some test cases. RESULTS: The measured minimum dose covering PTV2 was within 5% of the homogeneous prescription dose of 70 Gy for 6 MV photons, while a lower dose (89% of prescription dose) was measured for 18 MV. The algorithms overpredicted the minimum dose to PTV2 by 6-18%. If the monitor units had been reduced according to simplistic heterogeneous calculations, the small PTV2 would have only been covered by 58 Gy for 18 MV irradiation. Based on this, a clinician may opt to actually increase the prescribed dose, thereby offsetting decreased monitor units. None of the algorithms predicted the diffuse penumbra associated with 18 MV photons in lung. CONCLUSION: Before adjusting dose prescriptions based on heterogeneity corrections, realistic phantom studies must be performed. The accuracy and effect of the corrections must then be assessed. The deficient coverage of PTV2 by the 18 MV beam compares unfavorably with the slight increase (5%) in hot spots associated with 6 MV. Our studies support strong caution before reducing dose prescriptions based on simple algorithms.

Algorithms↗
PubMed1997

The direct calculation of parametric images from dynamic PET data using maximum-likelihood iterative reconstruction.

The aim of this work is to calculate, directly from projection data, concise images characterizing the spatial and temporal distribution of labelled compounds from dynamic PET data. Conventionally, image reconstruction and the calculation of parametric images are performed sequentially. By combining the two processes, low-noise parametric images are obtained, using a computationally feasible parametric iterative reconstruction (PIR) algorithm. PIR is performed by restricting the pixel time-activity curves to a positive linear sum of predefined time characteristics. The weights in this sum are then calculated directly from the PET projection data, using an iterative algorithm based on a maximum-likelihood iterative algorithm commonly used for tomographic reconstruction. The ability of the algorithm to extract known kinetic components from the raw data is assessed, using data from both a phantom experiment and clinical studies. The calculated parametric images indicate differential kinetic behaviour and have been used to aid in the identification of tissues which exhibit differences in the handling of labelled compounds. These parametric images should be helpful in defining regions of interest with similar functional behaviour, and with FDG Patlak analysis.

Algorithms↗
PubMed1997

Eating disorder symptomatology in major depression.

This study evaluated the relationship between eating disorder symptomatology and severity of depression in depressed outpatients before and after antidepressant treatment and assessed the effect of treatment on eating disorder symptomatology. One hundred thirty-nine outpatients (82 women and 57 men) with major depressive disorder (MDD) filled out the eating disorder inventory (EDI) before and after 8 weeks of treatment with fluoxetine 20 mg/day. Diagnoses of MDD and possible comorbid eating disorders were made with the Structured Clinical Interview for DSM-III-R-Patient Edition. Several EDI subscales correlated significantly with severity of depression both at baseline and endpoint. Additionally, all EDI subscales showed a statistically significant decrease following fluoxetine treatment, and changes in depression severity following treatment were significantly related to changes in EDI bulimia, ineffectiveness, perfectionism, and interpersonal distress subscale scores. These results suggest that several symptoms characteristic of eating disordered patients are linked to the severity of depressive symptoms. Decreases in eating disorder symptomatology following antidepressant treatment may be related to changes in depressive symptoms.

Adult↗