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Biomedical subjects

D Stephenson

Publications and source records attributed to D Stephenson.

At least 19 recordsLinked to original sources
PubMed2006

Once daily MMX mesalazine for the treatment of mild-to-moderate ulcerative colitis: a phase II, dose-ranging study.

BACKGROUND: SPD476 (MMX mesalazine), is a novel, once daily, high-strength mesalazine formulation (1.2 g/tablet) that utilizes Multi Matrix System (MMX) technology to delay and extend delivery of the active drug throughout the colon. AIM: To assess the safety and efficacy of MMX mesalazine in patients with mild-to-moderately active ulcerative colitis, in a pilot, phase II, randomized, multicentre, double-blind, parallel-group, dose-ranging study (SPD476-202). METHODS: Thirty-eight patients with mild-to-moderately active ulcerative colitis were randomized to MMX mesalazine 1.2, 2.4 or 4.8 g/day given once daily for 8 weeks. Remission ulcerative colitis-disease activity index (UC-DAI) < or =1, a score of 0 for rectal bleeding and stool frequency, and > or =1 -point reduction in sigmoidoscopy score from baseline was the primary end point. RESULTS: Week 8 remission rates were 0%, 31% and 18% of patients receiving MMX mesalazine 1.2, 2.4 and 4.8 g/day respectively. No statistically significant difference in remission was observed between treatment groups. MMX mesalazine 2.4 and 4.8 g/day groups demonstrated greater improvement in overall UC-DAI and component scores from baseline, compared with the 1.2 g/day group. CONCLUSION: MMX mesalazine given as 2.4 or 4.8 g/day once daily is well tolerated and effective for the treatment of mild-to-moderately active ulcerative colitis.

Adolescent↗
PubMed2006

The impact of intellectual functioning on symptoms and service use in schizophrenia.

BACKGROUND: This study aims to evaluate differences in the clinical profiles and use of psychiatric services by people with schizophrenia with and without borderline intellectual functioning. Both groups in this study were receiving standard community psychiatric care. METHODS: A naturalistic sample of 372 people with schizophrenia completed the National Adult Reading Test. Data were collected prospectively over 18 months on psychiatric symptoms and service use. Three hundred and thirteen had normal intellectual functioning (mean age 43, range 20-76 years) and 59 had borderline or lower intellectual functioning (mean age 45, range 21-81 years). This was defined by a National Adult Reading Test error score of more than 40. RESULTS: People with borderline or lower intellectual functioning had a lower quality of life, more severe psychotic symptoms, reduced functioning and fewer antidepressant prescriptions. There were no significant differences in service use including hospital admission. CONCLUSIONS: People with schizophrenia and borderline or lower intellectual functioning are a more disabled group within general adult psychiatric services who should be the focus of initiatives for improved service delivery.

Activities of Daily Living↗
PubMed2006

Maintenance antipsychotic medication patterns in outpatient schizophrenia patients: a naturalistic cohort study.

OBJECTIVE: Newer antipsychotics are increasingly used in schizophrenia maintenance. The UK change has been slow with little known on switching patterns. We aimed to investigate antipsychotic prescribing patterns in schizophrenia patients. METHOD: A naturalistic six-site cohort sample of 600 patients were interviewed by researchers at 6-monthly intervals for 2 years to record their clinical and social functioning; use of services and medication for the preceding 6 months was obtained by structured extraction from clinical case notes. RESULTS: Alterations in antipsychotic medication were frequent in this group, mainly during periods of inpatient care. Atypical prescribing increased steadily, though slowly, across the period. Polypharmacy was less than anticipated. CONCLUSION: Inpatient care remains the main forum for switching of antipsychotics. The UK maintains a slow shift to atypical antipsychotics.

Adult↗
PubMed2006

The cardiovascular and respiratory health of people with schizophrenia.

OBJECTIVE: To examine the cardiovascular and respiratory health of people with severe mental illness (SMI) and compare findings with the Health Surveys for England. METHOD: A prospective, multi-centre observational prevalence study of 602 patients with schizophrenia-related psychoses carried out in six locations across the UK over 24 months. RESULTS: Compared with general population subjects, people with SMI reported higher rates of angina and respiratory symptoms and had poor lung function. Much of this increased risk could be explained by lifestyle risk factors; there were increased levels of obesity among younger people with SMI. CONCLUSION: Key indicators of the cardiovascular and respiratory health of people with SMI are poor compared with those of the general population. Care plans should prioritize interventions to attenuate lifestyle risk factors. Evidence of increasing obesity in younger patients is of particular concern, predicting even greater health needs in the future.

Adolescent↗
PubMed2004

The dental health of people with schizophrenia.

OBJECTIVE: To examine the dental health of community dwelling people with schizophrenia and to compare results with those in the general population. METHOD: Dental health of 428 people with schizophrenia in six different areas of the UK was assessed by a self-report questionnaire. RESULTS: Compared with the general population, significantly more of the younger patients were edentate (3-39% vs. 1-20%) and fewer had more than 20 teeth (70% vs. 83%). None of four dental health targets had been achieved in the patient population. More patients had last visited the dentist because of trouble with their teeth; fewer had visited for a check-up. Fewer patients cleaned their teeth daily; this group had more negative symptoms. CONCLUSION: The dental health of people with schizophrenia is poor. Community mental health teams should encourage them to attend their community dentist regularly.

Adult↗
PubMed2003

Pilot study of an Internet-based electronic patient treatment record and communication system for haemophilia, Advoy.com.

Communication between patients and haemophilia centres is important in the management of the disease. Traditionally this has been done by paper records which give retrospective and often incomplete data. This paper describes the development and pilot study of a novel Internet-based electronic patient treatment log. The advantages of the system include up to date information available to the haemophilia centre, less data entry, better quality records and an individualized alert system for significant events. The system was tested with ten patients at three UK haemophilia centres and found to be feasible and easy to use. In the opinion of the patients and health care professionals involved in the pilot study, the system improves quality, accuracy, accessibility and usefulness of patient generated data. Development of the system is ongoing and its use extended to other haemophilia centres.

Attitude of Health Personnel↗
PubMed2002

Economic evaluation of gemcitabine alone and in combination with cisplatin in the treatment of nonsmall cell lung cancer.

OBJECTIVE: To evaluate the cost effectiveness of gemcitabine in the treatment of nonsmall cell lung cancer (NSCLC). METHODS: Gemcitabine was compared with best supportive care and gemcitabine/cisplatin was compared with three standard chemotherapies and four other novel chemotherapy combinations. Costs and effectiveness measures were based on resource and outcome data from previously reported clinical trials. All direct costs associated with NSCLC treatment were included and adjusted to year 2000 values. PERSPECTIVE: UK National Health Service. RESULTS: Gemcitabine plus best supportive care was associated with an incremental cost per progression-free life year gained of pound sterling5228 compared with best supportive care alone. In comparison with standard chemotherapies, gemcitabine/cisplatin was associated with an incremental cost per progression-free life year gained of pound sterling1751 versus etoposide/cisplatin and cost per 1-year survival gain of pound sterling5681 versus mitomycin/vinblastine/platinum. Incremental cost per tumour response was pound sterling2032 relative to etoposide/cisplatin, pound sterling5169 relative to mitomycin/ifosfamide/cisplatin and pound sterling6240 relative to mitomycin/vinblastine/platinum. Compared with four novel (newer) combination chemotherapies gemcitabine/ cisplatin showed cost savings in each case, with the same or better outcome. Thus, gemcitabine/cisplatin showed improved cost effectiveness and dominance. Sensitivity analyses showed the results were robust to variations to the values of key parameters. CONCLUSION: Gemcitabine alone or in combination with cisplatin was assessed to be a cost-effective or cost-saving therapy when compared with best supportive care, standard chemotherapy regimens and novel chemotherapy combinations. Chemotherapy regimens containing gemcitabine therefore represent good value for money and efficient use of healthcare resources in the treatment of advanced NSCLC.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2000

Transcription factor nuclear factor-kappa B is activated in neurons after focal cerebral ischemia.

Nuclear factor-kappa B (NF-kappaB) is a multisubunit transcription factor that when activated induces the expression of genes encoding acute-phase proteins, cell adhesion molecules, cell surface receptors, and cytokines. NF-kappaB is composed of a variety of protein subunits of which p50-and p65-kDa (RelA) are the most widely studied. Under resting conditions, these subunits reside in the cytoplasm as an inactive complex bound by inhibitor proteins, IkappaB alpha and IkappaB beta. On activation, IkappaB is phosphorylated by IkappaB kinase and ubiquitinated and degraded by the proteasome; simultaneously, the active heterodimer translocates to the nucleus where it can initiate gene transcription. In the periphery, NF-kappaB is involved in inflammation through stimulation of the production of inflammatory mediators. The role of NF-kappaB in the brain is unclear. In vitro, NF-kappaB activation can be either protective or deleterious. The role of NF-kappaB in ischemic neuronal cell death in vivo was investigated. Adult male rats were subjected to 2 hours of focal ischemia induced by middle cerebral artery occlusion (MCAO). At 2, 6, and 12 hours after reperfusion, the expression and transactivation of NF-kappaB in ischemic versus nonischemic cortex and striatum were determined by immunocytochemistry and by electrophoretic mobility gel-shift analysis. At all time points studied, p50 and p65 immunoreactivity was found exclusively in the nuclei of cortical and striatal neurons in the ischemic hemisphere. The contralateral nonischemic hemisphere showed no evidence of nuclear NF-kappaB immunoreactivity. Double immunofluorescence confirmed expression of p50 in nuclei of neurons. Increased NF-kappaB DNA-binding activity in nuclear extracts prepared from the ischemic hemisphere was further substantiated by electrophoretic mobility gel-shift analysis. Because the activation of NF-kappaB by many stimuli can be blocked by antioxidants in vitro, the effect of the antioxidant, LY341122, previously shown to be neuroprotective, on NF-kappaB activation in the MCAO model was evaluated. No significant activation of NF-kappaB was found by electrophoretic mobility gel-shift analysis in animals treated with LY341122. These results demonstrate that transient focal cerebral ischemia results in activation of NF-kappaB in neurons and supports previous observations that neuroprotective antioxidants may inhibit neuronal death by preventing the activation of NF-kappaB.

Animals↗
PubMed2000

Detecting hereditary hemochromatosis.

Hereditary hemochromatosis is the most commonly inherited autosomal recessive disorder. Hemochromatosis is a current or potential progression of abnormally high accumulations of iron in the liver. If left untreated, the condition can lead to chronic or irreversible hepatic fibrosis, cirrhosis, hepatocellular carcinoma, arthritis, and organ failure. Common signs and symptoms seen in the primary care setting include fatigue, weakness, abdominal pain, palpitations, skin pigmentation changes, and arthropathy, but any symptom associated with organ damage may be reported. Because prompt intervention can cease or reverse the debilitating effects of iron overload, prompt disease diagnosis and treatments are imperative.

Algorithms↗
PubMed2000

Compliance with antidepressant medication in the treatment of major depressive disorder in primary care: a randomized comparison of fluoxetine and a tricyclic antidepressant.

OBJECTIVE: Many claims have been made for superior compliance with selective serotonin reuptake inhibitors (SSRIs) compared with tricyclic antidepressants, but to date meta-analyses have not confirmed reduced dropouts in randomized controlled trials. The authors used a randomized study design to evaluate differential compliance with antidepressant medications in a primary care setting. METHOD: A total of 152 patients treated in 10 primary care practices in the United Kingdom were included in a randomized, open-label, parallel-group study of fluoxetine and dothiepin at therapeutic doses for 12 weeks. Compliance was assessed by using pill count, patient questionnaires, and the Medication Event Monitoring System. RESULTS: The level of compliance with fluoxetine was numerically higher than the level of compliance with dothiepin on all three primary outcome measures, although the differences were not significant. In a secondary analysis using data from the Medication Event Monitoring System, both a survival analysis for length of time without a gap in medicine taking and a derived compliance index showed a significant advantage to fluoxetine. Patients in the fluoxetine group reported superior response on the health transition scale of the 36-item Short-Form Health Survey Questionnaire and numerically greater improvement on the Hamilton Depression Rating Scale. In both treatment arms patients with a superior compliance index were more likely to have improved in Hamilton depression scale scores by the last study visit. CONCLUSIONS: This study supports recent meta-analyses of SSRIs versus tricyclic antidepressants in finding no significant differences in crude indices of compliance between fluoxetine and dothiepin, despite marked differences in side effect profile and dose regimen. However, both a survival analysis and a new measure that takes account of prolonged periods of noncompliance distinguished between the treatments and was associated with improvement in both groups.

Adolescent↗
PubMed1999

Cytosolic phospholipase A2 is induced in reactive glia following different forms of neurodegeneration.

Many recent studies have emphasized the deleterious role of inflammation in CNS injury. Increases in free fatty acids, eicosanoids, and products of lipid peroxidation are known to occur in various conditions of acute and chronic CNS injury, including cerebral ischemia, traumatic brain injury, and Alzheimer's disease. Although an inflammatory response can be induced by many different means, phospholipases, such as cytosolic phospholipase A(2) (cPLA(2)), may play an important role in the production of inflammatory mediators and in the production of other potential second messengers. cPLA(2) hydrolyzes membrane phospholipids and its activity liberates free fatty acids leading directly to the production of eicosanoids. We investigated the cellular localization of cytosolic phospholipase A(2) in the CNS following: (1) focal and global cerebral ischemia, (2) facial nerve axotomy, (3) human cases of Alzheimer's disease, (4) transgenic mice overexpressing mutant superoxide dismutase, a mouse model of amyotrophic lateral sclerosis, and (5) transgenic mice overexpressing mutant amyloid precursor protein, which exhibits age-related amyloid deposition characteristic of Alzheimer's disease. We show that in every condition evaluated, cytosolic phospholipase A(2) is present in reactive glial cells within the precise region of neuron loss. In conditions where neurons did not degenerate or are protected from death, cytosolic phospholipase A(2) is not observed. Both astrocytes and microglial cells are immunoreactive for cytosolic phospholipase A(2) following injury, with astrocytes being the most consistent cell type expressing cytosolic phospholipase A(2). The presence of cytosolic phospholipase A(2) does not merely overlap with reactive astroglia, as reactive astrocytes were observed that did not exhibit cytosolic phospholipase A(2) immunoreactivity. In most conditions evaluated, inflammatory processes have been postulated to play a pivotal role and may even participate in neuronal cell death. These results suggest that cytosolic phospholipase A(2) may prove an attractive therapeutic target for neurodegeneration.

Alzheimer Disease↗
PubMed1999

Longitudinal patterns of antidepressant prescribing in primary care in the UK: comparison with treatment guidelines.

The objective of this study was to determine whether patients beginning therapy on the most common tricyclic antidepressants (TCAs) and selective serotonin reuptake inhibitors (SSRIs) differed in their likelihood of having antidepressant treatment that was consistent with recommended treatment guidelines in the UK. An analytical file constructed from a large general practitioner medical records database (DIN-LINK) from the UK for the years 1992-97 was constructed. A total of 16,204 patients with a new episode of antidepressant therapy who initiated therapy on one of the most often prescribed TCAs (amitriptyline, dothiepin, imipramine and lofepramine) or SSRIs (fluoxetine, paroxetine and sertraline) were analysed. A dichotomous measure was defined to indicate whether subjects were prescribed at least 120 days of antidepressant therapy at an adequate average daily dose within the first 6 months after initiation of therapy. Only 6.0% of patients initiating therapy on aTCA and 32.9% of patients initiating therapy on a SSRI were prescribed antidepressant treatment that was consistent with treatment guidelines. After controlling for observable characteristics, patients who initiated therapy on a SSRI were much more likely (odds ratio=7.473, p<0.001) to have a prescribed average daily dose and duration consistent with recommended treatment guidelines within the first 6 months of initiating therapy than were patients who initiated therapy on a TCA. These findings suggest that initial antidepressant selection is an important determinant of whether the subsequent course of treatment is consistent with current national guidelines for the treatment of depression in the UK.

Adult↗
PubMed1999

Determination of monoamine oxidase activity by HPLC with fluorimetric detection.

The aldehyde produced from the oxidative deamination of primary and secondary amines by the monoamine oxidases (EC 1.4.3.4; MAO) or the semicarbazide-sensitive amine oxidases (EC 1.4.3.6; SSAO) may be determined followed reaction at elevated temperatures with 2-diphenylacetyl-1,3-indandione-1-hydrazone (DIH), separation by high-performance chromatography liquid (C-8 column, eluting isocratically with acetonitrile, ammonium acetate, water) and fluorimetric detection (excitation and emission wavelengths 430 and 525 nm). The detection limits for benzaldehyde, p-hydroxybenzaldehyde and 2-phenylacetaldehyde were 125 nM, 150 and 62.3 nM, respectively. Thus the assay is appropriate for determination of amine oxidase activities towards benzylamine, 2-phenylethylamine and tyramine. The fluorescence of the DIH adduct with indole-3-aldehyde was strongly quenched, giving a relatively high detection limit (17.5 microM). The detection limit was lower (3.8 microM) when the absorbance at 430 nm was monitored. Enzyme activities determined by this procedure were shown to be linear with enzyme-protein concentration (rat liver mitochondria). The presence of 1-2 mM semicarbazide, necessary for determining MAO activities in samples also containing SSAO, did not adversely affect the derivatization reaction. The DIH-aldehyde adducts were sufficiently stable to permit their storage at low temperatures prior to assay. The product produced by reaction of 5-hydroxyindole acetaldehyde with DIH had no significant fluorescence and too low an absorbance at 430 nm to allow its determination for assay of activities towards 5-HT. This procedure can also measure succinic semialdehyde (detection limit 240 nM) and thus would be applicable to the determination of GABA transaminase activity.

Aldehydes↗
PubMed1998

Transient global forebrain ischemia induces a prolonged expression of the caspase-3 mRNA in rat hippocampal CA1 pyramidal neurons.

The authors recently cloned a cDNA for an ICE/CED3-related cysteine protease from rat brain, which is closely related to human CPP32 (now designated caspase-3). In situ hybridization histochemistry revealed a profound developmental regulation of the caspase-3 transcript in rat brain, with relatively high levels of caspase-3 mRNA observed in neurons of the fetal and neonatal brain and low levels of mRNA in neurons of the adult brain. The authors report that transient forebrain ischemia, which results in a delayed apoptotic death of CA1 pyramidal neurons, results in prolonged expression of caspase-3 mRNA in these same pyramidal neurons. Up-regulation of caspase-3 mRNA in CA1 pyramidal neurons is prominent 24 hours after transient global ischemia, and expression is maintained at higher levels for at least 72 hours after ischemia. However, by 96 hours after ischemia, a marked decrease in caspase-3 mRNA expression is observed in CA1 pyramidal neurons, showing severe degenerative changes (e.g., nuclear condensation). By contrast, there is no change in the expression of a closely related member of caspase family, caspase-2, in CA1 pyramidal neurons after global ischemia. Instead, caspase-2 mRNA is induced in lamina layers of cerebral cortex 24 hours after the ischemia. A selective and prolonged induction of the caspase-3 gene in committed CA1 pyramidal neurons suggests that transcriptional activation of this caspase-3 gene may be involved in the apoptotic cell death cascade of CA1 neurons after transient global ischemia.

Animals↗
PubMed1997

Zyme, a novel and potentially amyloidogenic enzyme cDNA isolated from Alzheimer's disease brain.

The deposition of the beta amyloid peptide in neuritic plaques and cerebral blood vessels is a hallmark of Alzheimer's disease (AD) pathology. The major component of the amyloid deposit is a 4.2-kDa polypeptide termed amyloid beta-protein of 39-43 residues, which is derived from processing of a larger amyloid precursor protein (APP). It is hypothesized that a chymotrypsin-like enzyme is involved in the processing of APP. We have discovered a new serine protease from the AD brain by polymerase chain reaction amplification of DNA sequences representing active site homologous regions of chymotrypsin-like enzymes. A cDNA clone was identified as one out of one million that encodes Zyme, a serine protease. Messenger RNA encoding Zyme can be detected in some mammalian species but not in mice, rats, or hamster. Zyme is expressed predominantly in brain, kidney, and salivary gland. Zyme mRNA cannot be detected in fetal brain but is seen in adult brain. The Zyme gene maps to chromosome 19q13.3, a region which shows genetic linkage with late onset familial Alzheimer's disease. When Zyme cDNA is co-expressed with the APP cDNA in 293 (human embryonic kidney) cells, amyloidogenic fragments are detected using C-terminal antibody to APP. These co-transfected cells release an abundance of truncated amyloid beta-protein peptide and shows a reduction of residues 17-42 of Abeta (P3) peptide. Zyme is immunolocalized to perivascular cells in monkey cortex and the AD brain. In addition, Zyme is localized to microglial cells in our AD brain sample. The amyloidogenic potential and localization in brain may indicate a role for this protease in amyloid precursor processing and AD.

Adult↗
PubMed1997

Selective loss of neuronal Na+-dependent phosphate cotransporter mRNA in CA1 pyramidal neuron following global ischemia.

A recently identified neuronal Na+-dependent phosphate cotransporter (rBNPI) has been shown to import inorganic phosphate (P(i)) required for the production of high-energy phosphates which are vital to neuronal energy metabolism. In the present study, we have examined the expression of rBNPI mRNA in the hippocampus of rats subjected to 30 min of global ischemia by four-vessel occlusion. In situ hybridization reveals that transient forebrain ischemia results in a selective reduction in rBNPI mRNA expression in CA1 pyramidal neurons of the hippocampus. Expression of rBNPI is significantly reduced by 24 h and completely absent at 72 h following global ischemia when CA1 pyramidal neurons begin to show cell damage. By contrast, there is no change in the expression of Nedd2 mRNA, a developmentally regulated cell death gene, in CA1 pyramidal neurons at these same time points. The loss of rBNPI transcripts appears to be selective for CA1 pyramidal neurons since rBNPI mRNA expression is unchanged in neurons of the CA2-CA4 pyramidal cell layers following global ischemia. Our data indicate that an early reduction of rBNPI transcripts may contribute to a reduction in P(i)-dependent energy metabolism or signal transduction which has been reported in CA1 hippocampal neurons following global ischemia.

Animals↗
PubMed1996

Nuclear and cytoplasmic localization of the beta-amyloid peptide (1-43) in transfected 293 cells.

Cultures of transformed human embryonic kidney 293 cells were transiently transfected with minigene constructs coding for the Abeta peptide (1-43). The Abeta minigene used in this study consisted of exons 16 and 17 of the amyloid precursor protein gene, including the 6000+ bp intronic region. Two of the constructs used in this study, human amyloid precursor protein (APP) promoter-driven Abeta minigene and BK virus enhancer/adenovirus major late promoter-driven Abeta minigene, did not contain a signal peptide sequence, whereas the third, human APP promoter-signal peptide Abeta minigene did not contain the human APP signal sequence. The resulting Abeta products were detected by immune precipitation, using 10D5 antibody and Western blot analysis, using R1280 antisera, as SDS stable oligomers in cell lysates of cells containing all three constructs or in culture media when produced by the signal peptide construct. Evaluation of the cells by immunocytochemistry using conventional and transmission electron microscopy indicated that the cells transfected with constructs without the signal peptide accumulated immunoreactive Abeta primarily in the nucleus.

Amyloid beta-Peptides↗