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J Campbell

Publications and source records attributed to J Campbell.

At least 37 records · Page 2Linked to original sources
PubMed2003

Extraction of short-latency evoked potentials using a combination of wavelets and evolutionary algorithms.

Somatosensory evoked potentials, recorded at the spine or scalp of a patient, are contaminated by noise. It is common practice to use ensemble averaging to remove the noise, which usually requires a large number of responses to produce one averaged signal. In this paper a post-processing technique is shown which uses a combination of wavelets and evolutionary algorithms to produce a representative waveform with fewer responses. The most suitable wavelets and a set of weights are selected by an evolutionary algorithm to form a filter bank, which enhances the extraction of evoked potentials from noisy recordings.

Algorithms↗
PubMed2003

Doxorubicin in combination with fluorouracil and cyclophosphamide (i.v. FAC regimen, day 1, 21) versus methotrexate in combination with fluorouracil and cyclophosphamide (i.v. CMF regimen, day 1, 21) as adjuvant chemotherapy for operable breast cancer: a study by the GEICAM group.

BACKGROUND: The purpose of this study was to determine the relative efficacy of doxorubicin versus methotrexate in combination with intravenous cyclophosphamide and 5-fluorouracil (FAC versus CMF) as adjuvant chemotherapy for operable breast cancer. PATIENTS AND METHODS: Over a 4-year period, 985 women undergoing curative surgery for breast cancer (T1-3 N0-2 M0, stage I-IIIA, UICC) from nine hospitals were stratified with respect to axillary node involvement (node positive versus node negative) and randomized to receive either FAC (500/50/500/m(2)) every 3 weeks for six cycles or CMF (600/60/600/m(2)) every 3 weeks for six cycles. RESULTS: The relative dose intensities of FAC and CMF were 87% and 85% of planned doses, respectively. Unadjusted data indicated a non-significant trend towards better results with FAC. In the prospectively formed subset of node-negative patients, disease-free survival and overall survival were statistically superior in the FAC treatment arm (P = 0.041 and 0.034, respectively), but this advantage was not seen in the subset of node-positive patients, probably because of a difference in the percentage of patients with four or more positive nodes. Adjusting data for size of treatment effect and potential interactions (number of positive nodes, tumor size, treatment center), the overall relative risk (RR) of disease recurrence and death were significantly lower with FAC treatment (RR 1.2, P = 0.03, and RR 1.3, P = 0.05, respectively). This result was mainly due to the difference observed in the node-negative patient population. Toxicity was mild: FAC induced more alopecia, emesis, mucositis and cardiotoxicity; this last was of clinical concern, but was infrequent and manageable. CMF induced more conjunctivitis and weight gain. There were no toxic deaths. CONCLUSIONS: Doxorubicin in combination with day 1 i.v. cyclophosphamide and 5-fluorouracil is superior to methotrexate in combination with day 1 i.v. cyclophosphamide and 5-fluorouracil as adjuvant chemotherapy for operable breast cancer. A treatment effect is particularly evident in the node-negative patients. Although the clinical toxicity of FAC is greater than that of CMF, the levels were manageable and clinically acceptable.

Adolescent↗
PubMed2003

Characterization of rotaviruses causing diarrhoea in Vietnamese children.

Faecal samples from 123 children admitted to the Centre for Tropical Diseases in Ho Chi Minh city, Vietnam, with acute watery diarrhoea were screened by negative-stain electron microscopy for viral enteropathogens. In addition to the 48 children who were found to be infected with rotavirus only, one had both rotavirus and astrovirus, two had adenovirus 40/41, and one had astrovirus only. The rotaviruses were subjected to molecular analysis by electropherotyping, G- and P-genotyping (by reverse-transcriptase PCR), and amplicon sequencing. By use of newly designed PCR primers, all 49 isolates could be G-genotyped and all but one P-genotyped. Novel variants of G1-G1*--were the most commonly detected G-genotype and such variants of P[8]-P[8*]--were the second commonest P-genotype. The P[8*] and G1* amplicons were, respectively, only 92%-93.4% and 88.1%-89% similar to the corresponding sequences from the prototype P[8] G1 rotavirus, Wa. Several unusual P- and G-genotype combinations were detected. Four (8%) of the children investigated were each found to be co-infected with two different rotaviruses. These data add to our knowledge of the continuing evolution and diversity of human rotaviruses, and should help in the rational design of vaccines.

Adenoviridae↗
PubMed2002

Creutzfeldt-Jakob disease associated with a deletion of two repeats in the prion protein gene.

A two-octapeptide repeat deletion of the prion protein gene has been recently observed in a patient with a 2-year history of dementia and a clinical diagnosis of possible Creutzfeldt-Jakob disease (CJD). The authors report a similar deletion in a patient with a definitive diagnosis of CJD. Since the two-repeat deletion has not been observed in large, population-based studies, the two cases suggest that this deletion is a new pathogenic mutation associated with CJD.

Autopsy↗
PubMed2002

Single origin of right and left pulmonary artery branches from ascending aorta with nonbranching main pulmonary artery: relevance to a new understanding of truncus arteriosus.

We report the third known case of origin of the right and left pulmonary artery branches from the ascending aorta via a short common pulmonary artery. A large unbranching main pulmonary artery opened through a patent ductus arteriosus into the descending thoracic aorta. Preductal coarctation of the aorta and multiple congenital anomalies were also present. This rare cardiovascular malformation facilitates a new anatomic and developmental understanding of truncus arteriosus.

Aorta↗
PubMed2002

Dimensionality and clinical importance of pain and disability in hand osteoarthritis: Development of the Australian/Canadian (AUSCAN) Osteoarthritis Hand Index.

OBJECTIVE: To develop a reliable, valid, and responsive self-administered questionnaire to probe pain, stiffness and physical disability in patients with osteoarthritis (OA) of the hand. DESIGN: In order to assess the dimensionality of the symptomatology of hand OA, a self-administered questionnaire was developed to probe various aspects of pain (10 items), stiffness (two items), and physical function (83 items). The question inventory was generated from eight existing health status measures and an interactive process involving four rheumatologists, two physiotherapists, and an orthopaedic surgeon. RESULTS: Face-to-face interviews were conducted with 50 OA hand patients; 39 females and 11 males with mean age 62.8 years and mean disease duration 9.4 years. Items retained were those which fulfilled specified selection criteria: prevalence > or =60% and mean importance score approximating or exceeding 2.0 Item exclusion criteria included low prevalence, gender-based, ambiguous, duplicates or similarities, alternatives, composite items, and items that were too restrictive. This process resulted in five pain, one stiffness and nine function items which have been proposed for incorporation in the AUSCAN Index. CONCLUSIONS: Using a traditional development strategy, we have constructed a self-administered multi-dimensional outcome measure for assessing hand OA. The next stage includes reliability, validity and responsiveness testing of the 15-item questionnaire.

Activities of Daily Living↗
PubMed2002

Clinimetric properties of the AUSCAN Osteoarthritis Hand Index: an evaluation of reliability, validity and responsiveness.

OBJECTIVE: To assess the reliability, validity and responsiveness of the Australian/Canadian (AUSCAN) Osteoarthritis Hand Index in both Likert (LK) and Visual Analogue (VA)-scaled formats. METHODS: Two separate studies were conducted; the first addressing reliability and validity issues and the second addressing index responsiveness. In a group of 50 patients with osteoarthritis (OA) of the hand, test-retest reliability was assessed at a 1-week interval and internal consistency from single administrations of the Index. Construct validity was evaluated against several other outcome measures including the Functional Index for Hand Osteoarthritis (FIHOA), separate patient and physician global assessments, Doyle Index, grip strength, pinch grip, and Health Assessment Questionnaire. A 6-week washout retreatment design was used in a group of 44 OA hand patients to assess index responsiveness and comparative responsiveness against the FIHOA. RESULTS: Reliability and construct validity coefficients confirm the reliability and construct validity of both the AUSCAN LK3.0 and AUSCAN VA3.0 Indices. The washout retreatment study establishes index responsiveness and suggests that the AUSCAN LK3.0 and AUSCAN VA3.0 Indices may be more responsive than the FIHOA. CONCLUSIONS: The patient self-completed AUSCAN LK3.0 and AUSCAN VA3.0 Indices are reliable, valid and responsive and can be recommended as primary outcome measures for future hand OA clinical trials.

Adult↗
PubMed2002

Morbidity of tamoxifen-perceptions of patients and healthcare professionals.

There is little published data comparing patients' and doctors' perceptions of tamoxifen-related morbidity and toxicity, in particular in terms of side-effects which are not medically serious but which disrupt quality of life. We undertook a questionnaire-based study of 210 randomly selected, disease-free pre- and post-menopausal breast cancer patients to assess perceived morbidity whilst taking tamoxifen. We also questioned 143 healthcare professionals, including nurses, GPs and oncologists, on their opinions of tamoxifen-related side-effects. This study suggests that patients experience significant morbidity while taking adjuvant tamoxifen but will tolerate this for the sake of anticipated benefits. Healthcare professionals particularly hospital-based doctors and specialist nurses tend to overestimate the prevalence and severity of tamoxifen-associated symptoms.

Journal Article↗
PubMed2002

Rhythmic variations in pain, stiffness, and manual dexterity in hand osteoarthritis.

OBJECTIVE: To explore circadian variation in pain, stiffness, and manual dexterity in patients with hand osteoarthritis (OA). METHODS: Twenty one patients with hand OA, as defined by ACR criteria (17 women, four men, mean age 62.2 years, range 52-74 years) self rated pain and stiffness on separate 10 cm horizontal visual analogue scales and performed bead intubation coordinometry (BIC) six times each day (on waking up, at bedtime, and every four hours in between) for 10 consecutive days. Each series (using data with the trend removed if there was a significant trend) was analysed for circadian rhythmicity by a cosine vector technique (single cosinor). With individual data expressed as the percentage of the mean, group rhythm characteristics at period 24 hours were summarised for each variable by population mean cosinor analysis. RESULTS: Individual analyses identified significant circadian rhythms at p<or=0.05 for pain (n=15/21), stiffness (n=16/20), and dexterity (n=18/21), and a significant circadian rhythm on a group basis was identified for pain (p=0.013), stiffness (p<0.001), and dexterity (p<0.001). Pain was least at 1610 and stiffness at 1618. Peak dexterity occurred in mid-afternoon at 1548 and occurred within the 95% confidence interval of least pain (1312-1800) and stiffness (1520-1732). CONCLUSIONS: Dexterity was influenced by the patient's level of pain or stiffness, which changed systematically throughout the day. Similar results have been previously reported in 14 patients with rheumatoid arthritis where peak dexterity occurred at 1544 and at 1528 in 14 age and sex matched healthy controls. The predictability of rhythmic variation in pain, stiffness, and dexterity has implications for scheduling activities of daily living and for timing antirheumatic drug treatment.

Aged↗
PubMed2002

[Familial indifference to pain with somatosensory asymmetry: possible central anomaly].

A family of seven siblings is described. The mother and six siblings have been examined, the eldest and youngest of whom suffer from congenital indifference to pain , although both were ticklish, and itched. The functions examined included somatosensory perception thresholds and autonomic functions; perception thresholds were greatly raised in the painfree subjects and to a lesser extent in some other family members, asymmetrically in all cases, being higher in the dominant hand. Painfree Subject 1 also underwent cerebrospinal fluid analysis at age 16, which showed normal B-endorphin levels but undetectable enkephalins. Electrophysiological tests when a child demonstrated notably that most (raised) measured values were lowered by naloxone. Light microscopic sural nerve biopsy performed on painfree Subject 1 in childhood did not suggest any abnormalities other than a thickened nerve sheath. Threshold asymmetry has not been observed in large numbers of subjects without neurological deficits. There were no significant autonomic changes in any tested family member, though there was some asymmetry. It is suggested that the findings may imply a congenital anomaly of the central nervous system which accounts for the somatosensory, biochemical, and electrophysiological abnormalities.

Adolescent↗
PubMed2001

Vertical transmission of Kaposi's sarcoma-associated herpesvirus.

Little is presently known about the specific routes of transmission of Kaposi's sarcoma-associated herpesvirus (KSHV) or human herpesvirus-8 (HHV-8). To investigate whether this agent might be transmitted vertically from mother to infant, we conducted a study on 89 KSHV seropositive mothers and their newborn infants. Thirteen mothers (14.6%) had KSHV DNA detected in their peripheral blood mononuclear cells (PBMC). Two of 89 samples drawn at birth from infants born to KSHV seropositive mothers had KSHV DNA detectable within their PBMC. These findings suggest that KSHV can be transmitted perinatally, but infrequently. Other routes of transmission such as horizontal transmission remain the most likely means of KSHV transmission.

Adolescent↗
PubMed2001

First examples of thallium chalcogenide cages. Syntheses, 77Se, 203Tl, and 205Tl NMR study of the Tl4Se5(4-) and Tl4Se6(4-) anions, the X-ray crystal structure of (2,2,2-crypt-K+)3Tl5Se5(3-), and theoretical studies.

The Tl5Se5(3-) anion has been obtained by extracting KTlSe in ethylenediamine in the presence of 2,2,2-crypt. The salt, (2,2,2-crypt-K+)3Tl5Se5(3-), crystallizes in the triclinic system, space group P1, with Z = 2 and a = 11.676(2) A, b = 16.017(3) A, c = 25.421(5) A, alpha = 82.42(3) degrees, beta = 88.47(3) degrees, gamma = 69.03(3) degrees at -123 degrees C. Two other mixed oxidation state TlI/TlIII anions; Tl4Se5(4-) and Tl4Se6(4-), have been obtained by extracting KTlSe into liquid NH3 in the presence of 2,2,2-crypt and have been characterized in solution by low-temperature 77Se, 203Tl, and 205Tl NMR spectroscopy and were shown to exist as a 1:1 equilibrium mixture at -40 degrees C. The couplings, 1J(203,205Tl-77Se) and 2J(203,205Tl-203,205Tl), have been observed for Tl4Se5(4-) and Tl4Se6(4-) and have been used to arrive at the solution structures of both anions. Structural assignments were achieved by detailed analyses and simulations of all spin multiplets that comprise the 205,203Tl NMR spectra and that arise from natural abundance 205,203Tl and 77Se or enriched 77Se isotopomer distributions. The structures of all three anions are based on a Tl4Se4 cube in which Tl and Se atoms occupy alternate corners. There are one and two exo-selenium atoms bonded to thallium in Tl4Se5(4-) and Tl4Se6(4-), respectively, so that these thalliums are four-coordinate and possess a formal oxidation state of +3 and the remaining three-coordinate thallium atoms are in the +1 oxidation state. The structure of Tl5Se5(3-) may be formally regarded as an adduct in which Tl+ is coordinated to the unique exo-selenium and to two seleniums in a cube face containing the TlIII atom. The Tl4Se5(4-), Tl4Se6(4-), and Tl5Se5(3-) anions and the presently unknown, but structurally related, Tl4Se4(4-) anion can be described as electron-precise cages. Ab initio methods at the MP2 level of theory show that Tl4Se5(4-), Tl4Se6(4-), and Tl5Se5(3-) exhibit true minima and display geometrical parameters that are in excellent agreement with their experimental cubanoid structures, and that Tl4Se4(4-) is cube-shaped (Td point symmetry). The gas-phase energetics associated with plausible routes to the formation and interconversions of these anions have been determined by ab initio methods and assessed. It is proposed that all three cubanoid anions are derived from the known Tl2Se2(2-), TlSe3(3-), Se2(2-), and polyselenide anions that have been shown to be present in the solutions they are derived from.

Journal Article↗
PubMed2001

hprt mutant frequencies, nonpulmonary malignancies, and domestic radon exposure: "postmortem" analysis of an interesting hypothesis.

The hypothesis that exposure to domestic radon raises the risk for leukemia and other nonpulmonary cancers has been proposed and tested in a number of epidemiologic studies over the past decade. During this period, interest in this hypothesis was heightened by evidence of increased frequencies of mutations at the hypoxanthine guanine phosphoribosyl transferase (hprt) gene in persons exposed to domestic radon (Bridges BA et al. [1991]: Lancet 337:1187-1189). An extension of this study (Cole J et al. [lsqb[1996]: Radiat Res 145:61-69) and two independent studies (Albering HJ et al. [1992[: Lancet 340:739; Albering HJ et al. [1994[: Lancet 344:750-751) found that hprt mutant frequency was not correlated with domestic radon exposure, and two well-designed epidemiologic studies showed no evidence of a relation between radon exposure and leukemia in children or adults. In this report, we present additional data from a study of Colorado high school students showing no correlation between domestic radon exposure and hprt mutant frequency. We use reanalyses of previous studies of radon and hprt mutant frequency to identify problems with this assay as a biomarker for domestic radon exposure and to illustrate difficulties in interpreting the statistical data. We also show with analyses of combined data sets that there is no support for the hypothesis that domestic radon exposure elevates hprt mutant frequency. Taken together, the scientific evidence provides a useful example of the problems associated with analyzing and interpreting data that link environmental exposures, biomarkers, and diseases in epidemiologic studies.

Adolescent↗
PubMed2001

Health care providers' missed opportunities for preventing femicide.

BACKGROUND: Homicide of women (femicide) by intimate partners is the most serious form of violence against women. The purpose of this analysis of a larger multisite study was to describe health care use in the year prior to murder of women by their intimate partner in order to identify opportunities for intervention to prevent femicide. METHODS: A sample of femicide cases was identified from police or medical examiner records. Participants (n = 311) were proxy informants (most often female family members) of victims of intimate partner femicide from 11 U.S. cities. Information about prior domestic abuse and use of health care and other helping agencies for victims and perpetrators was obtained during structured telephone interviews. RESULTS: Most victims had been abused by their partners (66%) and had used health care agencies for either injury or physical or mental health problems (41%). Among women who had been pregnant during the relationship, 23% were beaten by partners during pregnancy. Among perpetrators with fair or poor physical health, 53% had contact with physicians and 15% with fair or poor mental health had seen a doctor about their mental health problem. Among perpetrators with substance problems, 5.4% had used alcohol treatment programs and 5.7% had used drug treatment programs. CONCLUSIONS: Frequent contacts with helping agencies by victims and perpetrators represent opportunities for the prevention of femicide by health care providers.

Adolescent↗
PubMed2001

Thought-action fusion and anxiety disorders symptoms in normal adolescents.

The present study examined thought-action fusion (TAF) in a large sample of normal adolescents (n=427). Participants completed the Thought-Action Fusion Questionnaire for Adolescents (TAFQ-A) and scales measuring trait anxiety, symptoms of obsessive-compulsive disorder, other anxiety disorders, and depression. Results showed that the TAFQ-A is a reliable instrument assessing two dimensions of TAF, viz. Morality (i.e., the belief that unacceptable thoughts are morally equivalent to overt actions) and Likelihood (i.e., the belief that thinking of an unacceptable or disturbing situation will increase the probability that that situation actually occurs). Furthermore, TAF was not only associated with symptoms of OCD, but also with symptoms of other anxiety disorders and depression. However, when controlling for levels of trait anxiety, most connections between TAF and anxiety disorders symptoms disappeared. Symptoms of OCD and generalised anxiety remained significantly related to TAF. Altogether, the data are supportive of the notion that TAF is involved in a broad range of anxiety disorders and in particular OCD.

Adolescent↗
PubMed2001

Systematic study of steric and spatial contributions to molecular recognition by non-covalent imprinted polymers.

Although molecular imprinting is a widely accepted method for producing template specific polymers, the general rules for prediction and control of the binding and catalytic properties of these materials are still not fully understood. One reason for this is the problematic structural analysis of the active sites in the polymers, which are not amenable to X-ray crystallography or microscopic techniques due to their amorphous and heterogeneous nature. Therefore, molecular probes have been the most informative agents for the analysis of the structure of active sites. This paper focuses on the steric and geometrical aspects of shape recognition in non-covalent imprinted polymers, with particular effort to minimize other factors contributing to molecular recognition by the polymers. Chiral amine compounds with systematic changes in spatial, distal and conformational components of sterically controlled molecular recognition were investigated for use as non-covalent imprinted polymers. Chromatographic studies revealed that steric and spatial interactions influence the selectivity properties of imprinted polymers in a predictable fashion.

Journal Article↗
PubMed2001

Absconding of patients from an independent UK psychiatric hospital: a 3-year retrospective analysis of events and characteristics of absconders.

The need for accurate local information on the scale, nature and outcome of absconding or Absence Without Leave (AWOL) from an independent UK psychiatric hospital led to this 3-year (1997-1999) retrospective analysis of of AWOL data. One hundred and forty-eight AWOL incidents involving 88 patients were identified. Absconders were found to be significantly younger, more likely to be detained upon admission and more likely to be unmarried than a control group (n = 1378) of non-absconders. There were no significant differences for sex, length of admission or ethnicity. Descriptive data on the circumstances surrounding AWOL events are given, with at least 24 (16.2%) incidents having serious adverse outcomes. Baseline absconding rates are presented for the specialist clinical divisions within the hospital. There is a need for more detailed studies of absconding by patients within the Adolescent Mental Health Service subgroup where the absconding rate was relatively high and engagement in risk activity whilst AWOL relatively frequent.

Adolescent↗