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D Clark

Publications and source records attributed to D Clark.

At least 37 records · Page 2Linked to original sources
PubMed2005

Measurement of Wgamma and Zgamma production in pp collisions at square root s=1.96 TeV.

The standard model predictions for Wgamma and Zgamma production are tested using an integrated luminosity of 200 pb(-1) of pp collision data collected at the Collider Detector at Fermilab. The cross sections are measured by selecting leptonic decays of the W and Z bosons, and photons with transverse energy ET>7 GeV that are well separated from leptons. The production cross sections and kinematic distributions for the Wgamma and Zgamma data are compared to SM predictions.

Journal Article↗
PubMed2005

Local injection of a glutamate uptake inhibitor into the ventral tegmental area produces sensitization to the behavioural effects of d-amphetamine.

Circumstantial evidence suggests that sensitization to the behavioral effects of d-amphetamine is mediated by increased glutamate levels in the ventral tegmental area. To test this directly, the present study examined whether increasing glutamate levels in the ventral tegmental area with a glutamate uptake inhibitor is sufficient, in the absence of d-amphetamine administration, to elicit sensitization to a subsequent d-amphetamine challenge. Rats were treated bilaterally once a day for 2 days with either intra-ventral tegmental area L-trans-pyrollidine-2,4-dicarboxylic acid (50 nmol), saline, L-trans-pyrollidine-2,4-dicarboxylic acid coadministered with the competitive N-methyl-d-aspartate antagonist (+/-)-3-(2-carboxy-piperazin-4-yl)-propyl-1-phosphonic acid; CPP, 0.5 nmol), or CPP alone (0.5 nmol; all 1.0 microl/side). Following a 2 day withdrawal period, all rats were administered systemic d-amphetamine (1 mg/kg, i.p.). Repeated intra-ventral tegmental area injection of L-trans-pyrollidine-2,4-dicarboxylic acid sensitized animals to the behavioral effects of a systemic d-amphetamine challenge, an action which was blocked by co-administration of CPP. The results directly implicate ventral tegmental area glutamate in the process of sensitization to d-amphetamine. Furthermore, they demonstrate that inhibition of glutamate uptake produces the neuroadaptations necessary to induce sensitization, adding support to the contention that d-amphetamine sensitizes by modulating glutamate uptake.

Animals↗
PubMed2005

Complementary role of adjunctive breast magnetic resonance imaging and scintimammography in patients of all ages undergoing breast cancer surgery.

The aims of this study were to assess breast MRI and scintimammography (SMM) for the detection of breast cancer, and to determine any complementary role of these tests to each other and conventional imaging. Seventy-two patients (age 35-81 years) with a suspicious breast mass were investigated by mammography, breast ultrasound, breast MRI and SMM before undergoing surgical excision of the breast mass. Sensitivity, specificity and area under receiver operator characteristic curves were calculated for each test. Of the 72 patients, there were 66 proven malignant tumours, including two patients with bilateral breast cancer. When comparing the diagnostic sensitivity of breast MRI and SMM for lesion size, both tests showed higher sensitivities for lesions >25 mm in size, particularly for SMM. When these tests were compared for patient age, patients less than 51 years showed higher sensitivities for both tests. This was statistically significant for breast MRI. The overall respective diagnostic sensitivities for mammography, mammography with breast ultrasound, breast MRI and SMM were 56, 67, 86 and 85%. The differences were significant between mammography, mammography/ultrasound and both breast MRI and SMM. Breast MRI and SMM offer incremental diagnostic advantage in the diagnosis of breast cancer. Although improved diagnostic accuracy is seen in patients of all ages, those patients less than 51 years of age receive the greatest diagnostic benefit.

Adult↗
PubMed2005

Treated threshold stage 3 versus spontaneously regressed subthreshold stage 3 retinopathy of prematurity: a study of motility, refractive, and anatomical outcomes at 6 months and 36 months.

AIM: To compare the visual acuity (VA), spherical equivalent refractive error, motility, and anatomical outcomes in children with treated regressed threshold stage 3 retinopathy of prematurity (ROP) and those with spontaneously regressed subthreshold stage 3 ROP. METHOD: 6 month and 3 year data collected from infants examined between 1989 and 1999 with regressed stage 3 ROP, with or without treatment were retrospectively reviewed. RESULTS: 85 infants were included in this study. 40 eyes received cryotherapy, 81 eyes laser photocoagulation, and 34 eyes had spontaneously regressed subthreshold stage 3 ROP. Grating acuity score > or =2 cycles/degree (c/d) at 6 months was predictive of optotype acuity > or =6/9 in 69% of eyes and a score <2 c/d at 6 months was predictive of acuity < 6/9 in 88% of eyes. Eyes with subthreshold stage 3 ROP were twice as likely to have VA of 6/9 or better at 36 months than the treated eyes. The mean spherical equivalent refractive error at 36 months was -6.5 dioptres (D) (-21.5D to +1.38D) in cryotherapy treated eyes, -2.4D (-13D to +4D) in the laser group, and -0.22D (-9D to +2.25D) in the subthreshold group. Eyes within the treated groups were more myopic than the eyes within the spontaneously regressed group (p = 0.005). At 36 months, 42 out of the 85 infants (that is, 49%) had strabismus (44% in the cryotherapy group, 26% in the laser group, and 25% in the subthreshold group). There was a statistically significant association between the presence of strabismus and anisometropia (p = 0.016) and strabismus and intraventricular haemorrhage (IVH) (p = 0.005). There was a statistically significant difference in the incidence of strabismus between mild and moderate and severe grade IVH (p = 0.01). Eight out of 40 eyes in the cryotherapy group and six out of the 81 eyes in the laser group developed macular ectopia. None of the eyes in the spontaneously regressed group had macular dragging. CONCLUSIONS: In this study, the grating acuity at 6 months was a good predictor of the 3 year optotype acuity in all groups. Eyes with spontaneously regressed subthreshold stage 3 ROP were associated with better vision at 3 years of age and a lesser degree of myopia compared to the treated groups. Strabismus developed predominantly in the treated groups and was frequently associated with neurological damage and/or anisometropia. The spontaneously regressed subthreshold stage 3 group had a better anatomical outcome compared to the groups in which the retinopathy regressed following treatment.

Cryotherapy↗
PubMed2004

Search for doubly charged Higgs bosons decaying to dileptons in pp collisions at square root of s=1.96 TeV.

We present the results of a search for doubly charged Higgs bosons (H+/-+/-) decaying to dileptons (ll(')) using approximately 240 pb(-1) of pp collision data collected by the CDF II experiment at the Fermilab Tevatron. In our search region, given by same-sign ll(') mass m(ll('))>80 GeV/c(2) (100 GeV/c(2) for ee channel), we observe no evidence for H+/-+/- production. We set limits on sigma(pp -->H++H---->l(+)l('+)l(-)l('-)) as a function of the mass of the H+/-+/- and the chirality of its couplings. Assuming exclusive same-sign dilepton decays, we derive lower mass limits on H(+/-+/-)(L) of 133, 136, and 115 GeV/c(2) in the ee, mumu, and emu channels, respectively, and a lower mass limit of 113 GeV/c(2) on H(+/-+/-)(R) in the mumu channel, all at the 95% confidence level.

Journal Article↗
PubMed2004

Measurement of the tt production cross section in pp collisions at sqrt[s]=1.96 TeV using dilepton events.

We report a measurement of the tt production cross section using dilepton events with jets and missing transverse energy in pp collisions at a center-of-mass energy of 1.96 TeV. Using a 197+/-12 pb(-1) data sample recorded by the upgraded Collider Detector at Fermilab, we use two complementary techniques to select candidate events. We compare the number of observed events and selected kinematical distributions with the predictions of the standard model and find good agreement. The combined result of the two techniques yields a tt production cross section of 7.0(+2.4)(-2.1)(stat)+1.6-1.1(syst)+/-0.4(lum) pb.

Journal Article↗
PubMed2004

Observation of the narrow state X(3872)-->J/psipi+pi- in pp collisions at sqaure root of s=1.96 TeV.

We report the observation of a narrow state decaying into J/psipi+pi- and produced in 220 pb(-1) of p p-bar collisions at =1.96 Tesqaure root of sV in the CDF II experiment. We observe 730+/-90 decays. The mass is measured to be 3871.3+/-0.7(stat)+/-0.4(syst) MeV/c2, with an observed width consistent with the detector resolution. This is in agreement with the recent observation by the Belle Collaboration of the X(3872) meson.

Journal Article↗
PubMed2004

Search for B0s-->micro+micro- and B0d-->micro+micro- decays in pp collisions at square root s = 1.96 TeV.

We report on a search for B(0)(s)-->micro(+)micro(-) and B(0)(d)-->micro(+)micro(-) decays in pp collisions at square root of s=1.96 TeV using 171 pb(-1) of data collected by the CDF II experiment at the Fermilab Tevatron Collider. The decay rates of these rare processes are sensitive to contributions from physics beyond the standard model. One event survives all our selection requirements, consistent with the background expectation. We derive branching ratio limits of B(B(0)(s)-->micro(+)micro(-))<5.8x10(-7) and B(B(0)(d)-->micro(+)micro(-))<1.5x10(-7) at 90% confidence level.

Journal Article↗
PubMed2004

Adhesion-related readmissions following gynaecological laparoscopy or laparotomy in Scotland: an epidemiological study of 24 046 patients.

BACKGROUND: Gynaecological laparotomies are associated with considerable adhesion-related burdens; however, few data are available concerning laparoscopic surgery. This study evaluated the epidemiology of adhesion-related readmissions following open and laparoscopic procedures. METHODS: Records from 24,046 patients undergoing gynaecological surgery in Scottish National Health Service hospitals during 1996 were assessed retrospectively. Cohorts comprised 15,197 patients undergoing laparoscopic surgery and 8849 patients undergoing laparotomies. Adhesion-related readmission episodes (directly and possibly related) were assessed over 4 years following initial surgery and were expressed as percentages of the number of initial procedures. RESULTS: Directly adhesion-related readmissions 1 year after initial laparoscopic surgery were: in the high-risk group (adhesiolysis and cyst drainage) 1.3%; medium-risk (therapeutic and diagnostic procedures not categorized as high- or low-risk) 1.5%; and low-risk (Fallopian tube sterilizations) 0.2%. Readmissions for laparotomy following surgery on the Fallopian tubes were 0.9%, ovaries 2.1%, uterus 0.6% and vagina 0%. Readmissions occurred at reduced rates in the second, third and fourth years after surgery. Exclusion of patients who underwent surgery within the previous 5 years resulted in reduced readmission rates following laparotomy and high-risk laparoscopy. CONCLUSIONS: With the exception of laparoscopic sterilizations, open and laparoscopic gynaecological surgery are associated with comparable risks of adhesion-related readmissions.

Female↗
PubMed2004

Serotonergic polymorphisms and psychotic disorders in populations from North Spain.

There is strong biological evidence relating alterations in the serotonergic system with mental disorders. These alterations may be originated at the DNA level by sequence mutations that alter the functioning of serotonin receptors and transporter. To test this hypothesis we investigated three genetic variants of the 5-HT2A receptor (-1438G/A, 102T/C and His452Tyr) and two variants of the serotonin transporter (a VNTR in the second intron and a 44 bp insertion/delition in the promoter region of the gene) in a clinical sample recruited in a human isolate and in surrounding areas in Northern Spain (N = 257) and in ethnically matched controls (N = 334). No clear association was found between 5-HT2A variants and psychosis. However, marginal associations were observed between the 5-HTT LPR and VNTR variants and psychosis (P < or = 0.05) indicating a minor contribution to psychosis of genetic alterations in this gene.

Adult↗
PubMed2004

Place of death: preferences among cancer patients and their carers.

The place of death of cancer patients has become an important theme in UK cancer and palliative care policy. This paper examines the place of death preferences of 41 terminally ill cancer patients and 18 of their informal carers, living in the Morecambe Bay area of north-west England. We interviewed cancer patients referred to the research team by 13 specialist palliative care professionals; patients had an estimated 3 months of life remaining. The study design involved an in-depth qualitative interview with each patient soon after referral to the study, followed by an interview some 4 weeks later and subsequent tracking interviews by telephone at 2-4 week intervals until death occurred. Interviews were also conducted with main coresident carers soon after patient referral to the study and again in the post-bereavement period. Thirteen factors were identified as shaping the place of death preference of patients and carers. These are organised into four thematic domains: the informal care resource, management of the body, experience of services, and existential perspectives. In documenting these factors, this paper adds significantly to current knowledge on the factors that shape place of death preference, a field of enquiry acknowledged to be underdeveloped (J. Palliative Med. 3 (2000) 287). More importantly, it uncovers some of the reasons that underpin these preferences. Our research revealed a much stronger preference for deaths in a hospice than had been anticipated, leading us to take a qualified stance on the current policy drive in favour of home deaths by those charged with delivering UK cancer and palliative care services.

Adult↗
PubMed2004

Threshold ROP.

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Gestational Age↗
PubMed2004

Equity of access to adult hospice inpatient care within north-west England.

There is a growing debate about the question of equity of access to hospice and palliative care services. Even countries with relatively well developed palliative care systems are considered to have problems of access and inequity of provision. Despite these concerns, we still lack a relevant evidence base to serve as a guide to action. We present an analysis of access to adult hospice inpatient provision in the north-west region of England that employs Geographical Information Systems (GIS). Measures of the possible demand for, and supply of, hospice inpatient services are used to determine the potential accessibility of cancer patients, assessed at the level of small areas (electoral wards). Further, the use of deprivation scores permits an analysis of the equity of access to adult inpatient hospice care, leading to the identification of areas where additional service provision may be warranted. Our research is subject to a number of caveats--it is limited to inpatient hospice provision and does not include other kinds of inpatient and community-based palliative care services. Likewise, we recognise that not everyone with cancer will require palliative care and also that palliative care needs exist among those with nonmalignant conditions. Nevertheless, our methodology is one that can also be applied more generally.

Adult↗
PubMed2004

Systematic review of the problems and issues of accessing specialist palliative care by patients, carers and health and social care professionals.

OBJECTIVES: To determine the problems and issues of accessing specialist palliative care by patients, informal carers and health and social care professionals involved in their care in primary and secondary care settings. DATA SOURCES: Eleven electronic databases (medical, health-related and social science) were searched from the beginning of 1997 to October 2003. Palliative Medicine (January 1997-October 2003) was also hand-searched. STUDY SELECTION: Systematic search for studies, reports and policy papers written in English. DATA EXTRACTION: Included papers were data-extracted and the quality of each included study was assessed using 10 questions on a 40-point scale. RESULTS: The search resulted in 9921 hits. Two hundred and seven papers were directly concerned with symptoms or issues of access, referral or barriers and obstacles to receiving palliative care. Only 40 (19%) papers met the inclusion criteria. Several barriers to access and referral to palliative care were identified including lack of knowledge and education amongst health and social care professionals, and a lack of standardized referral criteria. Some groups of people failed to receive timely referrals e.g., those from minority ethnic communities, older people and patients with nonmalignant conditions as well as people that are socially excluded e.g., homeless people. CONCLUSIONS: There is a need to improve education and knowledge about specialist palliative care and hospice care amongst health and social care professionals, patients and carers. Standardized referral criteria need to be developed. Further work is also needed to assess the needs of those not currently accessing palliative care services.

Aged↗