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M Dickson

Publications and source records attributed to M Dickson.

At least 19 recordsLinked to original sources
PubMed2002

Contaminated dental instruments.

There is current concern in the UK over the possible transmission of prions via contaminated surgical instruments. Some dental instruments (endodontic files) raise particular concerns by virtue of their intimate contact with terminal branches of the trigeminal nerve. A visual assessment using a dissecting light microscope and scanning electron microscopy of endodontic files after clinical use and subsequent decontamination was performed. The instruments examined were collected from general dental practices and from a dental hospital. Seventy-six per cent (22/29) of the files retrieved from general dental practices remained visibly contaminated, compared with 14% (5/37) from the dental hospital. Current methods for decontaminating endodontic instruments used in dentistry may be of an insufficient standard to completely remove biological material. Improved cleaning methods and the feasibility of single use endodontic instruments require further investigation.

Creutzfeldt-Jakob Syndrome↗
PubMed2001

Measurement of the relative branching fraction of upsilon(4S) to charged and neutral B-meson pairs.

We analyze 9.7x10(6) B_B pairs recorded with the CLEO detector to determine the production ratio of charged to neutral B-meson pairs produced at the Upsilon(4S) resonance. We measure the rates for B0-->J/psiK((*)0) and B+-->J/psiK((*)+) decays and use the world-average B-meson lifetime ratio to extract the relative widths f(+-) / f(00) = gamma(Upsilon(4S)-->B+B-) / gamma(Upsilon(4S)-->B0 B-0)) = 1.04+/-0.07(stat)+/-0.04(syst). With the assumption that f(+-)+f(00) = 1, we obtain f(00) = 0.49+/-0.02(stat)+/-0.01(syst) and f(+-) = 0.51+/-0.02(stat)+/-0.01(syst). This production ratio and its uncertainty apply to all exclusive B-meson branching fractions measured at the Upsilon(4S) resonance.

Journal Article↗
PubMed2001

Measurement of the lambda(+)(c) lifetime.

The Lambda+c lifetime is measured using 9.0 fb(-1) of e+e- annihilation data collected on or just below the Upsilon(4S) resonance with the CLEO II.V detector at CESR. Using an unbinned maximum likelihood fit, the Lambda+c lifetime is measured to be 179.6+/-6.9(stat)+/-4.4(syst) fs. The precision of this colliding beam measurement is comparable to other measurements, which are based on fixed-target experiments, with different systematic uncertainties.

Journal Article↗
PubMed2001

Comparative DNA sequence analysis of mouse and human protocadherin gene clusters.

The genomic organization of the human protocadherin alpha, beta, and gamma gene clusters (designated Pcdh alpha [gene symbol PCDHA], Pcdh beta [PCDHB], and Pcdh gamma [PCDHG]) is remarkably similar to that of immunoglobulin and T-cell receptor genes. The extracellular and transmembrane domains of each protocadherin protein are encoded by an unusually large "variable" region exon, while the intracellular domains are encoded by three small "constant" region exons located downstream from a tandem array of variable region exons. Here we report the results of a comparative DNA sequence analysis of the orthologous human (750 kb) and mouse (900 kb) protocadherin gene clusters. The organization of Pcdh alpha and Pcdh gamma gene clusters in the two species is virtually identical, whereas the mouse Pcdh beta gene cluster is larger and contains more genes than the human Pcdh beta gene cluster. We identified conserved DNA sequences upstream of the variable region exons, and found that these sequences are more conserved between orthologs than between paralogs. Within this region, there is a highly conserved DNA sequence motif located at about the same position upstream of the translation start codon of each variable region exon. In addition, the variable region of each gene cluster contains a rich array of CpG islands, whose location corresponds to the position of each variable region exon. These observations are consistent with the proposal that the expression of each variable region exon is regulated by a distinct promoter, which is highly conserved between orthologous variable region exons in mouse and human.

Animals↗
PubMed2000

Study of charmless hadronic B meson decays to pseudoscalar-vector final states.

We report results of searches for charmless hadronic B meson decays to pseudoscalar( pi(+/-), K+/-, pi(0), or K(0)(S))-vector( rho, K(*), or omega) final states. By using 9.7x10(6) BB pairs collected with the CLEO detector, we report the first observation of B(-)--->pi(-)rho(0), B(0)-->pi(+/-)rho(-/+), and B(-)-->pi(-)omega, which are expected to be dominated by hadronic b-->u transitions. The measured branching fractions are (10.4(+3.3)(-3.4)+/-2.1)x10(-6), (27.6(+8.4)(-7.4)+/-4.2)x10(-6), and (11.3(+3.3)(-2.9)+/-1. 4)x10(-6), respectively. Branching fraction upper limits are set for all of the other decay modes investigated.

Journal Article↗
PubMed2000

Search for CP violation in B+/- --> J/psiK+/- and B+/- --> psi(2S)K+/- decays.

We present a search for direct CP violation in B+/--->J/psiK+/- and B+/--->psi(2S)K+/- decays. In a sample of 9.7x10(6) B&Bmacr; meson pairs collected with the CLEO detector, we have fully reconstructed 534 B+/--->J/psiK+/- and 120 B+/--->psi(2S)K+/- decays with very low background. We have measured the CP-violating charge asymmetry to be [+1.8+/-4.3(stat)+/-0.4(syst)]% for B+/--->J/psiK+/- and [+2.0+/-9. 1(stat)+/-1.0(syst)]% for B+/--->psi(2S)K+/-.

Journal Article↗
PubMed2000

First observation of the decay B --> J/psistraight phiK

We present the first observation of the decay B-->J/psistraight phiK. Using 9.6x10(6) B&Bmacr; meson pairs collected with the CLEO detector, we have observed ten fully reconstructed B-->J/psistraight phiK candidates, whereas the estimated background is 0.5+/-0.2 event. We obtain a branching fraction of B(B-->J/psistraight phiK) = (8. 8(+3.5)(-3.0)[stat]+/-1.3[syst])x10(-5). This is the first observed B meson decay requiring the creation of an additional s&smacr; quark pair.

Journal Article↗
PubMed1998

Cross-sectional analysis of the relationship between national guideline recommended asthma drug therapy and emergency/hospital use within a managed care population.

BACKGROUND: Nationally recognized clinical guidelines provide recommended therapies for the treatment of asthma. Research demonstrating the impact of guideline recommended drug therapy on utilization [emergency department (ED) and hospitalizations] is beneficial when considering these guidelines for managing asthmatics within a managed care setting. OBJECTIVE: The purpose is to determine the relationship between ED/hospital claims and selected asthma drug therapies as recommended by the National Asthma Education Program Expert Panel and the National Heart, Lung, and Blood Institute/ World Health Organization Workshop. METHODS: The analysis is a retrospective, cross-sectional study within a managed care organization (MCO), serving 359,464 patients in the state of Florida. Asthma patients from all lines of business (Medicaid, Medicare, commercial) were stratified into subgroups based on the type of drug therapy utilized. Members included were those identified as having at least one prescription filled for an asthma medication between January 1, 1995 and June 30, 1995 and at least six consecutive months of enrollment within the health plan. Pharmacy and medical claims data were collected over a 1.5-year study period (January 1, 1995 through June 30, 1996) to assure follow-up on utilization was at a minimum 6 months and maximum 1.5 years. Outcomes were measured based on patient utilization of tertiary medical services (asthma-related ED and hospital visits) through claims. RESULTS: Total membership within the Florida MCO, reflected 359,464 members of whom 5.2% were identified as asthmatic. The asthma members were reviewed based on pharmacy claims data, identifying 26.2% of the members utilizing inhaled corticosteroids concomitantly with a short-acting beta2-agonist. Upon further review of this subset, 85% were utilizing short-acting beta2-agonists in quantities at or below recommended dosages. Patients not utilizing the beta2-agonist therapy according to the recommended dosing guidelines had a significantly higher incidence (P = .001) of ED and hospital use. The remaining asthma population was reviewed, identifying 33.2% of the members utilizing short-acting beta2-agonists alone. This subset revealed 97.6% were utilizing therapy according to the beta2-agonist dosing guidelines. Patients not utilizing the beta2-agonist therapy according to dosing guidelines had a significantly higher incidence (P = .016) of ED and hospital use. CONCLUSION: Assessment of asthma therapy in a managed care population demonstrates that there is a lower proportionate use of the ED and hospital in those patients treated in accordance to the asthma guideline recommendations.

Administration, Inhalation↗
PubMed1998

Pharmaceutical reference prices. How do they work in practice?

Reference pricing systems are reimbursement ceilings set by payers in an effort to constrain pharmaceutical expenditure for a private or public drug benefit. In recent years, many governments have adopted reference pricing either as a replacement or in addition to product specific price controls. Programme administrators should consider whether these policies are providing the intended benefits or whether there may be a more effective method. This article provides a review of reference pricing in Europe, North America and other countries. There are many similarities in the reference price policies but the markets to which they apply are more likely to be different. The European experience gives a 'once-for-all' lowering effect on pharmaceutical expenditure, often at the expense of compromises on prescribing. In Germany and The Netherlands, reference pricing has been relatively ineffective in lowering expenditure which has led to a succession of other interventions to achieve expenditure control goals. The US also has reference pricing, but it occurs in a very competitive market which may be responsible (at least in part) for the relatively modest growth in expenditure compared with European countries. The review of countries with reference pricing policies suggests that such policies are less effective than competitive markets in moderating pharmaceutical expenditure. Nonetheless, governments continue to pursue reference pricing strategies.

Canada↗
PubMed1997

ASHP national survey of pharmacy practice in acute care settings--1996.

The results of the 1996 ASHP national survey of pharmaceutical services in nonfederal community hospitals are presented and compared with the findings of the 1994 ASHP survey. A questionnaire was mailed to pharmacy directors at hospitals randomly sampled from those registered by the American Hospital Association. A total of 713 usable surveys were returned, for a net response rate of 37.1%. Inpatient pharmaceutical services were provided an average of 17.4 hours per weekday and ambulatory care pharmaceutical services 13.3 hours per weekday. Pharmacy directors were more likely to have duties beyond the department than in 1994 (24% versus 12%). The percentage reporting a patient-focused-care model increased from 18% in 1994 to 33% in 1996. The percentage reporting some automation of drug distribution increased from 55% in 1994 to 65% in 1996. Provision of ambulatory care pharmaceutical services was indicated by 63% of respondents, and 35% indicated providing home infusion services. Compared with 1994, pharmacy departments provided more clinical services to inpatients. The most commonly offered clinical pharmacy services for inpatients were drug-food interaction screening, drug-use evaluations, adverse-drug-reaction programs, and medication error management programs. The percentage providing pharmaceutical care to some extent increased from 44% to 60%. The percentage reporting that pharmacists had the authority to initiate or modify medication orders increased from 35% to 56%. A well-controlled formulary system was in place at 60% of hospitals, while 39% reported restrictions on prescribing. Nearly three fourths of respondents reported a therapeutic interchange policy. Mean inventory cost per patient day was $4.67, a decrease from $5.62 in 1994. About 68% of inpatient pharmacy expenditures went for drugs and fluids, 27% for staff, and 5% for other noncapital expenditures. The 1996 ASHP survey revealed continued growth in various activities related to patient care, such as implementation of patient-focused care, enhanced clinical services, and therapy management programs. Although the provision of pharmaceutical care increased, ample room for growth remains.

Ambulatory Care↗