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Biomedical subjects

D Mason

Publications and source records attributed to D Mason.

At least 73 records · Page 4Linked to original sources
PubMed1997

Substance use in remand prisoners: a consecutive case study.

OBJECTIVES: To determine the prevalence of drug and alcohol use among newly remanded prisoners, assess the effectiveness of prison reception screening, and examine the clinical management of substance misusers among remand prisoners. DESIGN: A consecutive case study of remand prisoners screened at reception for substance misuse and treatment needs and comparison of findings with those of prison reception screening and treatment provision. SETTING: A large adult male remand prison (Durham). SUBJECTS: 548 men aged 21 and over awaiting trial. MAIN OUTCOME MEASURES: Prevalence of substance misuse; treatment needs of substance misusers; effectiveness of prison reception screening for substance misuse; provision of detoxification programmes. RESULTS: Before remand 312 (57%) men were using illicit drugs and 181 (33%) met DSM-IV drug misuse or dependence criteria; 177 (32%) men met misuse or dependence criteria for alcohol. 391 (71%) men were judged to require help directed at their drug or alcohol use and 197 (36%) were judged to require a detoxification programme. The prison reception screen identified recent illicit drug use in 131 (24%) of 536 men and problem drinking in 103 (19%). Drug use was more likely to be identified by prison screening if an inmate was using multiple substances, using opiates, or had a diagnosis of abuse or dependence. 47 (9%) of 536 inmates were prescribed treatment to ease the symptoms of substance withdrawal. CONCLUSIONS: The prevalence of substance misuse in newly remanded prisoners is high. Prison reception health screening consistently underestimated drug and alcohol use. In many cases in which substance use is identified the quantities and numbers of different substances being used are underestimated. Initial management of inmates identified by prison screening as having problems with dependence producing substances is poor. Few receive a detoxification programme, so that many are left with the option of continuing to use drugs in prison or facing untreated withdrawal.

Adult↗
PubMed1997

Homeostatic mechanisms in the control of autoimmunity.

The data in this article challenge the current paradigm that self tolerance among T cells can be fully accounted for in terms of intrathymic clonal deletion, anergy and T-cell 'indifference'. We show that autoreactive T cells are under the control of a dominant T-cell-mediated control mechanism and that the thymus is a particularly potent source of these protective cells. We further show that 'peripheral' self antigens implicated in autoimmune diseases are expressed intrathmically and we consider possible consequences of such expression. Finally we show that autoantigen-specific peripheral T cells can be programmed to prevent autoimmunity.

Adrenal Glands↗
PubMed1997

A prospective, randomized evaluation of prophylactic intraaortic balloon counterpulsation in high risk patients with acute myocardial infarction treated with primary angioplasty. Second Primary Angioplasty in Myocardial Infarction (PAMI-II) Trial Investigators.

OBJECTIVES: A large, international, multicenter, prospective, randomized trial was performed to determine the role of prophylactic intraaortic balloon pump (IABP) counterpulsation after primary percutaneous transluminal coronary angioplasty (PTCA) in acute myocardial infarction (AMI). BACKGROUND: Previous studies have suggested that routine IABP use after primary PTCA reduces infarct-related artery reocclusion, augments myocardial recovery and improves clinical outcomes. METHODS: Cardiac catheterization was performed in 1,100 patients within 12 h of onset of AMI at 34 clinical centers. Clinical and angiographic variables were used to stratify patients undergoing primary PTCA into high and low risk groups. High risk patients were then randomized to 36 to 48 h of IABP (n = 211) or traditional care (n = 226). The study had 80% power to detect a reduction in the primary end point from 30% to 20%. RESULTS: There was no significant difference in the predefined primary combined end point of death, reinfarction, infarct-related artery reocclusion, stroke or new-onset heart failure or sustained hypotension in patients treated with an IABP versus those treated conservatively (28.9% vs. 29.2%, p = 0.95). The IABP strategy conferred modest benefits in reduction of recurrent ischemia (13.3% vs. 19.6%, p = 0.08) and subsequent unscheduled repeat catheterization (7.6% vs. 13.3%, p = 0.05) but did not reduce the rate of infarct-related artery reocclusion (6.7% vs. 5.5%, p = 0.64), reinfarction (6.2% vs. 8.0%, p = 0.46) or mortality (4.3% vs. 3.1%) and was associated with a higher incidence of stroke (2.4% vs. 0%, p = 0.03). IABP use did not result in enhanced myocardial recovery as assessed by paired admission to predischarge and 6-week rest and exercise left ventricular ejection fraction. CONCLUSIONS: In contrast to previous studies, a prophylactic IABP strategy after primary PTCA in hemodynamically stable high risk patients with AMI does not decrease the rates of infarct-related artery reocclusion or reinfarction, promote myocardial recovery or improve overall clinical outcome.

Angioplasty, Balloon, Coronary↗
PubMed1996

Prevalence of mental disorder in remand prisoners: consecutive case study.

OBJECTIVE: To define the prevalence of mental disorder and need for psychiatric treatment in new remand prisoners and to determine to what extent these are recognised and addressed in prison. DESIGN: Study of consecutive male remand prisoners at reception using a semistructured psychiatric interview. SETTING: Large remand prison for men (HMP Durham). SUBJECTS: 669 men aged 21 years and over on remand, awaiting trial. MAIN OUTCOME MEASURES: Prevalence of mental disorder at reception, prisoners need for psychiatric treatment, identification of mental disorder by prison reception screening, and numbers placed appropriately in the prison hospital. RESULTS: 148 (26%) men had one or more current mental disorders (excluding substance misuse) including 24 who were acutely psychotic. The prison reception screening identified 34 of the men with mental disorder and six of those with acute psychosis. 168 men required psychiatric treatment, 50 of whom required urgent intervention; 16 required immediate transfer to psychiatric hospital. Of these 50, 17 were placed on the hospital wing because of mental disorder recognised at prison screening. CONCLUSION: Not only is the prevalence of mental disorder, in particular severe mental illness, high in this population, but the numbers identified at reception are low and subsequent management in prison is poor.

Adult↗
PubMed1996

The thymus contains a high frequency of cells that prevent autoimmune diabetes on transfer into prediabetic recipients.

Rats of the PVG.RT1u strain develop autoimmune diabetes when thymectomized at 6 wk of age and are rendered relatively lymphopenic by a cumulative dose of 1,000 rads 137Cs gamma-irradiation given in four split doses. Previous studies have shown that the disease is prevented by the intravenous injection of 5 x 10(6) CD4+ CD45RC-TCR alpha beta+ RT6+ peripheral T cells from normal syngeneic donors. These cells have a memory phenotype and are presumably primed to some extrathymic antigen. However, we now report that the CD4+ CD8- population of mature thymocytes is a very potent source of cells, with the capacity to prevent diabetes in our lymphopenic animals. As few as 6 x 10(5) of these cells protect approximately 50% of recipients and the level of protection increases with cell dose. It appears that one characteristic of the intrathymic selection of the T cell repertoire is the generation of cells that regulate the autoimmune potential of peripheral T cells that have been neither clonally deleted intrathymically nor rendered irreversibly anergic in the periphery.

ADP Ribose Transferases↗
PubMed1996

Prognostic significance of BCL-2 expression and bcl-2 major breakpoint region rearrangement in diffuse large cell non-Hodgkin's lymphoma: a British National Lymphoma Investigation Study.

The Bcl-2 protein is capable of preventing apoptosis, and in vitro evidence suggests a role in drug resistance. It is expressed and the gene is rearranged in a proportion of cases of large-cell non-Hodgkin's lymphoma (NHL), but the clinical significance of these findings is controversial. The purpose of this study was to determine the influence of both Bcl-2 expression and major breakpoint region (MBR) bcl-2 rearrangement in a large cohort of prospectively accrued patients with intermediate-grade B-cell NHL treated in a standardized manner. All patients with Working Formulation F, G, or H NHL treated with cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) chemotherapy in British National Lymphoma investigation studies between July 1974 and April 1992 were considered for this study if the appropriate paraffin blocks were available. Paraffin sections from the diagnostic specimen were analyzed for evidence of MBR rearrangement using a polymerase chain reaction-based method, and for Bcl-2 expression using immunohistochemistry. Failure to achieve complete remission (CR), relapse, death from NHL, and deaths from all causes were used as end points to measure CR rate, actuarial relapse rate, actuarial survival from NHL, and actuarial overall survival. One hundred sixty-one suitable patients were identified and tested for the bcl-2 MBR translocation, with 27 (17%) found to be positive; 153 of these patients were tested with immunocytochemistry, and 84 (55%) showed evidence of Bcl-2 expression. For patients who achieved CR from the initial treatment, the relapse rate was significantly higher in those with Bcl-2 expression than in those without. In addition, multivariate analysis identified Bcl-2 expression as the only factor significantly related to relapse rate in the subjects measured. The cause-specific survival for NHL in the series as a whole was significantly lower in patients with Bcl-2 expression than in those without. MBR status had no significant influence on any of the outcome measures, but the number of MBR-positive patients was relatively small, and larger studies are required. In conclusion, in Working Formulation F, G, and H NHL of B-cell type, expression of Bcl-2 protein predicted independently for relapse.

Adult↗
PubMed1996

Glucocorticoids promote a TH2 cytokine response by CD4+ T cells in vitro.

Purified rat CD4+ T cells were activated in vitro in the presence or absence of the glucocorticoid dexamethasone. They were then expanded in IL-2 and subsequently restimulated, this time in the absence of the hormone. The results indicate that the exposure of the cells to dexamethasone in the primary stimulation changed the cytokine synthesis induced by the secondary stimulation. The mRNA levels for IL-4, IL-10, and IL-13 were all increased by the pretreatment, whereas synthesis of IFN-gamma and TNF-alpha was diminished. Further studies in which IL-4 was used together with dexamethasone showed that the cytokine potentiated the effect of the hormone. These data suggest that the neuroendocrine system can influence the cytokine response to pathogens and autoantigens in a way that favors Th2-type reactions. There are similar implications for therapy with glucocorticoids, and these drugs may be expected to have long term immunologic effects as well as short-lived immunosuppressive ones. The production of a mouse mAb, MRC-OX81, against rat IL-4 is also described.

Animals↗
PubMed1996

An immunohistochemical study of TAL-1 protein expression in leukaemias and lymphomas with a novel monoclonal antibody, 2TL 242.

Fifty formalin fixed, paraffin-embedded cases of T-acute lymphoblastic leukaemia (T-ALL) from 12 bone marrow trephines and 38 lymph nodes were stained with a new monoclonal antibody, 2TL 242, raised against recombinant TAL1 protein. The antibody recognizes TAL-1 polypeptides of molecular weight 39 and 41 kD (full length). In addition, a variety of other leukaemias and lymphomas were also stained with 2TL 242. Twenty-four of the 50 cases of T-ALL showed nuclear positivity, ranging from 10 to 90 per cent of leukaemic cells. A positive staining reaction was nuclear and stippled in pattern. Nuclear staining was not seen in any other type of leukaemia or lymphoma. Five cases of follicular lymphoma showed diffuse cytoplasmic staining of variable intensity. Although some background staining is obtained with this antibody, positive nuclear staining is easily distinguishable. This monoclonal antibody has a potential role in primary diagnosis and in the detection of minimal residual disease in T-ALL.

Antibodies, Monoclonal↗