Biomedical subjects

L Gibbons

Publications and source records attributed to L Gibbons.

At least 73 records · Page 4Linked to original sources

PubMed2001

Observation of new states decaying into Lambda+(c)pi(-)pi(+).

Using 13.7 fb(-1) of data recorded by the CLEO detector at the Cornell Electron Storage Ring, we investigate the spectrum of charmed baryons which decay into Lambda+(c)pi(-)pi(+) and are more massive than the Lambda+(c)(2625) baryon. We find evidence for two new states: one is broad and has an invariant mass roughly 480 MeV above that of the Lambda+(c) baryon; the other is narrow with an invariant mass of 596+/-1+/-2 MeV above the Lambda+(c) mass.

Journal Article↗

PubMed2001

Evidence of New States Decaying into Xi(*)(c)pi.

Using 13.7 fb(-1) of data recorded by the CLEO detector at Cornell Electron Storage Ring, we report evidence of two new charmed baryons: one decaying into Xi(0')(c)pi(+) with the subsequent decay Xi(0')(c)-->Xi(0)(c)gamma, and its isospin partner decaying into Xi(+')(c)pi(-) followed by Xi(+')(c)-->Xi(+)(c)gamma. We measure the following mass differences for the two states: M(Xi(0)(c)gammapi(+))-M(Xi(0)(c)) = 318.2+/-1.3+/-2.9 MeV and M(Xi(+)(c)gammapi(-))-M(Xi(+)(c)) = 324.0+/-1.3+/-3.0 MeV. We interpret these new states as the J(P) = 1 / 2(-) Xi(c1) particles, the charmed-strange analogs of the Lambda(+)(c1)(2593).

Journal Article↗

PubMed2001

Observation of B --> phiK and B --> phiK*.

We have studied two-body charmless hadronic decays of B mesons into the final states straight phiK and phiK(*). Using 9.7 million B&Bmacr; pairs collected with the CLEO II detector, we observe the decays B- --> phiK- and B0--> phiK(*0) with the following branching fractions: B(B--->phiK-) = (5.5(+2.1)(-1.8)+/-0.6)x10(-6) and B(B0--> phiK(*0)) = (11.5(+4.5+1.8)(-3.7-1.7))x10(-6). We also see evidence for the decays B0-->phiK0 and B---> phiK(*-). However, since the statistical significance is not overwhelming for these modes, we determine upper limits of <12.3x10(-6) and <22.5x10(-6) ( 90% confidence level), respectively.

Journal Article↗

PubMed2001

Observation of the Omega(0)(c) Charmed Baryon at CLEO.

The CLEO experiment at the CESR collider has used 13.7 fb(-1) of data to search for the production of the Omega(0)(c) (css ground state) in e(+)e(-) collisions at square root of (s) approximately 10.6 GeV. The modes used to study the Omega(0)(c) are Omega(-)pi(+), Omega(-)pi(+)pi(0), Xi-K-pi(+)pi(+), Xi0K-pi(+), and Omega(-)pi(+)pi(+)pi(-). We observe a signal of 40.4+/-9.0(stat) events at a mass of 2694.6+/-2.6(stat)+/-1.9(syst) MeV/c(2), for all modes combined.

Journal Article↗

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

Anxiety and Alzheimer's disease.

This study investigated symptoms of anxiety in two samples of clinic outpatients diagnosed with Alzheimer's disease (AD). Clinician and caregiver reports were obtained using standardized measures to characterize a broad array of anxiety symptoms. Anxiety symptoms were reported for a substantial proportion of subjects, regardless of whether clinician or caregiver ratings were used. Anxious or worried appearance was most common (68% to 71%), followed by fearfulness, tension, restlessness, and fidgeting (37% to 57%). Sleep disturbance and various somatic symptoms were less common (8% to 34%). Although anxiety symptoms were prevalent, only 5% to 6% of subjects met Diagnostic and Statistical Manual of Mental Disorders criteria for the diagnosis of generalized anxiety disorder. In both samples, anxiety symptoms were associated with depression, behavioral disturbances, and increased cognitive impairment. Study findings support a high occurrence of anxiety in patients with dementia, and treatments for anxiety might therefore be helpful in reducing the psychiatric burden of AD.

Aged↗

PubMed2001

Self-administered Expanded Disability Status Scale with functional system scores correlates well with a physician-administered test.

BACKGROUND: Patient-administered measures are needed to assess disability cost-effectively in large epidemiological studies. SETTING: An outpatient clinic in a large multiple sclerosis center. METHODS: A self-administered EDSS questionnaire was developed (EDSS-S). Consecutive patients with clinically definite multiple sclerosis completed the EDSS-S (n=95). During the same visit, a physician completed an EDSS (EDSS-P). Scores below 4.0 were determined using functional system (FS) scores. Scores above 4.0 were calculated by two methods, using gait alone and using gait and functional system scores combined. RESULTS: EDSS-P scores ranged from 0-9.5 (mean 5.1, median 5.0, 78% female, age 17-78, mean age 45). Mean EDSS-P, EDSS-S and intraclass correlation coefficients of agreement were: EDSS using ambulation alone (4.6, 5.1, 0.89), EDSS using ambulation and FS scores (4.6, 5.3, 0.87), bowel/bladder FS scores (1.6, 1.7, 0.79), pyramidal FS scores (2.1, 2.4, 0.67), sensory FS scores (1.6, 2.1, 0.60), cerebellar FS scores (1.1, 1.6, 0.55), brainstem FS scores (0.5, 1.2, 0.45), vision FS scores (1.9, 1.3, 0.38), cerebral FS scores (0.6, 2.3, 0.27). CONCLUSIONS: Very good correlation was seen between patient and physician scores for EDSS and the bowel/bladder FS score. Four other FS scores correlated moderately. In general, patients scored themselves more disabled than physicians.

Activities of Daily Living↗

PubMed2001

Five-year relative survival from prostate, breast, colorectal and lung cancer.

OBJECTIVES: This article presents five-year relative survival rates for prostate, breast, colorectal and lung cancer diagnosed in 1992. Provincial variations are also examined. DATA SOURCES: Data are from the Canadian Cancer Registry, the National Cancer Incidence Reporting System, the Canadian Mortality Data Base, and life tables. ANALYTICAL TECHNIQUES: Analysis was conducted using the maximum likelihood method of Estève. Provincial rates were standardized to the age distribution of patients diagnosed with the specific cancer. Statistical tests were conducted to determine if the site-specific age-standardized provincial relative survival rates should be regarded as heterogeneous. (National estimates exclude Québec.) MAIN RESULTS: Five-year relative survival rates for ages 15 to 99 were highest for prostate cancer (88%) and lowest for lung cancer (17%, women; 14%, men). Relative survival rates for prostate, breast and male lung cancer differ among provinces. There was little inter-provincial variation in relative survival rates for colorectal cancer.

Adolescent↗

PubMed2001

Trends in colorectal cancer incidence and mortality.

OBJECTIVES: This article examines recent trends in the incidence of and mortality from colorectal cancer among Canadian men and women, then further analyzes trends by three subsites. DATA SOURCES: Incidence data for colorectal cancer were obtained from the National Cancer Incidence Reporting System and from the Canadian Cancer Registry. Mortality data were extracted from the Canadian Vital Statistics Database. Supplementary data on nutrition are from the National Population Health Survey. ANALYTICAL TECHNIQUES: Age-standardized incidence and mortality rates were calculated for men and women. Age-specific incidence and mortality rates were calculated by 10-year age groups. Joinpoint analysis was applied to detect statistically significant changes in linear trends. MAIN RESULTS: Since the mid-1980s, colorectal cancer incidence has been declining, with steeper rates of decrease among women. Decreasing rates of colorectal cancer are limited to tumours located in the distal colon and rectum; the incidence of cancers of the proximal colon has not changed over time.

Adult↗

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↗

PubMed2000

Incorporating physical activity advice into primary care: physician-delivered advice within the activity counseling trial.

INTRODUCTION: The Activity Counseling Trial (ACT) was designed to compare the effectiveness of physician advice alone with physician advice plus behavioral counseling, provided by ACT-trained health educators, to increase levels of physical activity in healthy, sedentary patients. The objective was to determine health care providers' adherence to the ACT protocol for delivering initial "physician" advice on physical activity and to determine providers' satisfaction with the protocol. METHODS: Fifty-four physicians or physician assistants from 11 primary care practices located in California, Texas, and Tennessee volunteered to participate as ACT-trained physicians. Providers were trained to integrate 3 to 4 minutes of initial physical activity advice into the routine office visits of sedentary patients, aged 35 to 75 years, with no acute or serious chronic conditions. This advice included assessment of current physical activities, advising the patient about an appropriate physical activity goal, and referring the patient to the health educator. Providers initialed forms to document delivery of advice, and ACT health educators recorded their advice on a computerized tracking system. A provider survey measured length of time spent advising patients about physical activity and provider satisfaction with the program. RESULTS: Ninety-nine percent of patients received the initial physician advice about physical activity. Eighty-three percent of the providers spent less than 5 to 6 minutes, and 46% spent the recommended 3 to 4 minutes providing advice. Sixty-three percent said the advice resulted in little or no increase in the length of an office visit, and 83% said participation was an asset to their clinics. CONCLUSIONS: Providers incorporated brief physical activity advice into routine primary care visits with little disruption. Their response to the ACT advice protocol was positive and participation in the study was viewed as beneficial.

Adult↗

PubMed1999

Challenges faced in recruiting patients from primary care practices into a physical activity intervention trial. Activity Counseling Trial Research Group.

BACKGROUND: Special challenges are encountered when clinical trial recruitment targets a physician practice-based population, as opposed to recruiting from the community. Since most published information about recruitment has focused on the latter group, summation of successful primary-care-based recruitment strategies could prove useful for future trials recruiting from this population. METHODS: The Activity Counseling Trial (ACT) is a multicenter, randomized clinical trial that evaluated approaches to primary care-based interventions to increase physical activity in sedentary adults 35-75 years of age. Fifty-four clinicians from eight practices recruited 874 participants from three U.S. sites. Recruitment challenges that related, in great part, to the primary care setting included: (1) focusing on patients from ACT physician practices who had regularly scheduled or intend-to-schedule appointments within the next year; (2) placing trial staff in the clinical offices for recruitment purposes; and (3) placing trial interventionists in the physicians' offices. Other challenges were related to recruitment of minorities and men. RESULTS: Patient mailing yielded 43.4% of all randomized participants, followed by office-based questionnaires (32.5%) and direct telephone contact (21.6%). Based on a retrospective cost-effective analysis (indirect costs excluded), the self-administered office-based questionnaire was the least costly strategy for one site ($14/randomized participant), followed by patient mailing at another site ($58). The direct telephone contact method utilized at one site serving primarily a minority population yielded a per randomized participant cost of $80. CONCLUSIONS: Recruitment of clinical trial participants from practice-based populations requires modification of the strategies used to recruit from the community. Multiple strategies should be employed, followed closely for their respective yields, and adapted as needed.

Adult↗

PubMed1999

Alzheimer's disease symptom severity in blacks and whites.

OBJECTIVE: In order to determine whether there are racial differences in Alzheimer's Disease (AD) symptom severity and vascular comorbidities, we compared African-American (black) and Caucasian (white) patients with AD from similar socioeconomic backgrounds at the time the disease was first recognized. DESIGN: Cross-sectional observational study from a population-based dementia registry. PARTICIPANTS: Patients were enrolled from an HMO base population of 23,000 persons more than age 60 in Seattle, Washington. This study examines 453 subjects with probable AD (38 blacks (mean age 76.5, SD 6.4), and 415 whites (mean age 79.7, SD 6.7)). MEASUREMENTS: Measured were patient demographics, age at onset of AD, AD symptom duration, Mini-Mental State Exam (MMSE) score, Blessed Dementia Rating Scale, presence of psychiatric symptoms, and vascular comorbidities. RESULTS: Blacks had significantly lower mean cognitive scores (MMSE = 17.2, SD 5.6) compared with whites (MMSE = 20.2, SD 5.2, unpaired t test P < .01). The significant racial difference in MMSE scores persisted after controlling for education, duration of AD symptoms, age, and ADL impairment. Blacks and whites did not differ significantly regarding gender distribution, education level, income, or percent with early age of onset of AD. No statistically significant race-related differences were found in impairments in activities of daily living or symptoms of paranoia, hallucinations, or agitation. Blacks had significantly higher rates of hypertension (56%) compared with whites (34%) (Fisher's exact test, P = .013), but the rates of stroke and ischemic heart disease were similar. CONCLUSIONS: Despite uniform detection methods and controlling for reported duration of dementia symptoms, measured cognitive impairment is significantly more severe when AD is recognized in blacks compared with whites. The significantly higher prevalence of hypertension among black AD cases was not associated with excess cerebrovascular disease comorbidity. This study highlights a need for normative measurements of cognitive function in minority AD groups in order to distinguish differential cognitive symptom severity from possible measurement bias.

Activities of Daily Living↗

PubMed1998

Identifying potential need for cancer palliation in Nova Scotia.

OBJECTIVE: To assess the degree to which Nova Scotia cancer patients who may need palliative care are being referred to the comprehensive Halifax-based Palliative Care Program (PCP). METHODS: The authors conducted a retrospective, population-based study using administrative health data for all adults in Nova Scotia who died of cancer from 1988 to 1994. Proportions and odds ratios (ORs) were used to determine where there were differences in age, sex, place of residence, cancer cause of death, year of death and use of palliative radiotherapy between those who were referred to the PCP at the Halifax Infirmary and those who were not, and between those who were referred late (within 14 days of death) and those who were referred earlier. RESULTS: Of the 14,494 adults who died of cancer during the study period, 2057 (14.2%) were registered in the PCP. Within Halifax County, 1582 (36.4%) of the 4340 patients with terminal cancer were seen in the PCP. Predictors of PCP registration were residence in Halifax County (OR 19.2, 95% confidence interval [CI] 15.4-23.9), younger age compared with those 85 years of age or older (for those 20-54 years of age, OR 4.9, 95% CI 3.2-7.6; 55-64 years, OR 3.4, 95% CI 2.2-5.1; 65-74 years, OR 3.1, 95% CI 2.1-4.5; 75-84 years, OR 2.1, 95% CI 1.4-3.1), and having received palliative radiation (OR 1.8, 95% CI 1.5-2.2). PCP referral was associated directly with head and neck cancer (OR 5.4, 95% CI 3.0-9.7) and inversely with hematopoietic (OR 0.2, 95% CI 0.4-0.9), lymph node (OR 0.3, 95% CI 0.1-0.4) and lung (OR 0.6, 95% CI 0.4-0.9) cancer. Predictors of late referral (being referred to the PCP within 14 days of death) were age 65-84 years (OR 1.4, 95% CI 1.1-1.8) and 85 years and over (OR 1.8, 95% CI 1.1-3.0), no palliative radiation (OR 2.0, 95% CI 1.4-3.1) and cancer cause of death. People dying within 6 months of diagnosis were somewhat less likely to have been referred to the PCP (OR 0.8, 95% CI 0.6-0.9), but those who were referred were more likely to have been referred late (OR 2.6, 95% CI 2.0-3.5). INTERPRETATION: Referral to the PCP and earlier rather than late referral were more likely for younger people with terminal cancer, those who received palliative radiation and those living closer to the PCP. Referral rates also varied by cancer cause of death and the time between diagnosis and death.

Adult↗

PubMed1998

Human herpesvirus 6 reactivation is associated with cytomegalovirus infection and syndromes in kidney transplant recipients at risk for primary cytomegalovirus infection.

A potential association between human herpesvirus 6 (HHV-6) and cytomegalovirus (CMV) following kidney transplantation was explored by retrospectively testing serial serum specimens for HHV-6 IgG and IgM antibody. HHV-6 reactivation occurred in 35 (66%) of 53 transplant recipients. Fungal or parasitic opportunistic infections, graft rejection or loss, and mortality were not associated with HHV-6 reactivation. HHV-6 reactivation was associated with primary CMV infection (P=.001) and CMV syndrome (P=.003) and with trends for CMV-related hepatitis (P=.095), CMV-related neutropenia (P=.104), and serious CMV disease (P=.085). After controlling for CMV immune globulin (CMVIG) prophylaxis, the association between HHV-6 reactivation and primary CMV infection and syndrome remained significant (P=.002 and 0.006, respectively). The reduction in CMV syndrome among those receiving CMVIG prophylaxis remained significant (P=.007) after controlling for HHV-6 reactivation. HHV-6 reactivation in kidney transplant recipients at risk for primary CMV infection is associated with CMV infection and CMV-related disease, and these effects are independent of CMVIG prophylaxis.

Adult↗