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Biomedical subjects

A Hill

Publications and source records attributed to A Hill.

At least 55 records · Page 3Linked to original sources

Bulimics' responses to food cravings: is binge-eating a product of hunger or emotional state?

This study examined the roles of hunger, food craving and mood in the binge-eating episodes of bulimic patients, and identified the critical factors involved in the processes surrounding binge-eating episodes that follow cravings. This was a prospective study of the binge-eating behaviour of 15 women with bulimia nervosa. The participants used food intake diaries and Craving Records to self-monitor their nutritional behaviour, hunger levels and affective state. Cravings leading to a binge were associated with higher tension, lower mood and lower hunger than those cravings not leading to a binge. Levels of tension and hunger were the critical discriminating variables. The findings of the study support empirical evidence and models of emotional blocking in binge-eating behaviour and challenge the current cognitive starve-binge models of bulimia. The role of food cravings in the emotional blocking model is discussed in terms of a classically conditioned motivational state. Implications for treatment are addressed.

Adult↗

Transmission of hepatitis B virus infection in Gambian families revealed by phylogenetic analysis.

BACKGROUND/AIMS: Transmission of hepatitis B virus (HBV) in Africa occurs horizontally, with most people becoming infected between the ages of 1 and 5 years. The index cases in such events have been assumed to come from within the family unit or from sources outside the immediate family, such as other families or inhabitants of the same compound or village. Here, we define these routes of transmission by phylogenetic tree analysis of sequences from the entire pre-core/core region of the virus, in Gambian chronic carriers. METHODS: Amplification by polymerase chain reaction of serum extracted HBV-DNA was followed by direct sequencing of the target region. Following editing and alignment of these sequences, phylogenetic tree analysis was performed using the neighbour-joining and maximum-likelihood methods. RESULTS: Despite the overall conserved nature of the sequences of the pre-core/core region from 142 chronic carriers, distinct clusters were easily defined at the family and village level, but not on a wider geographical separation. CONCLUSIONS: Phylogenetic tree analysis of sequences obtained from family members provided strong evidence of intrafamilial transmission of HBV in at least two-thirds of the families studied from Gambia.

Cluster Analysis↗

A novel measuring system for the determination of paramagnetic particle labels for use in magneto-immunoassays.

Coated micrometer-sized paramagnetic particles (PMPs) are readily available and widely used in immunoassays, mainly for separation and as a solid phase. We have described in a separate paper a model sandwich assay in which approximately 1 x 10(5) to 1 x 10(6) PMPs (2.8 microm diameter) are immobilised on a plastic strip at the end of the assay. In this paper, we describe the design of an instrument that is capable of determining the number of PMPs on the plastic strip. The paper also describes a method of making standard plastic strips with known numbers of PMPs on them. A strip, when placed in a coil of wire in parallel with a capacitor, causes the resonant frequency of the coil to decrease because of the presence of the PMPs. The decrease in frequency relates directly to the number of PMPs on the strip. A circuit based on a voltage-controlled oscillator and a phase-locked loop is used to accurately measure the resonant frequency of the coil. The instrument is capable of detecting at least 1 x 10(5) PMPs immobilised on a plastic strip and has a linear response (r=0.99) for up to at least 3.33 x 10(6) PMPs. In terms of the iron content of the PMPs, the detection limit is approximately equal to 1.2 microg Fe in the paramagnetic particles and the sensitivity is approximately equal to 3 Hz per microg of Fe. The instrument is small and compact and together with a suitable magneto-immunoassay will have many applications, including near-patient monitoring.

Biosensing Techniques↗

The clinician's role in meeting patient information needs: suggested learning outcomes.

BACKGROUND: Patients have always fulfilled their information needs from a variety of different sources over time. Clinician-patient consultations are one part of that process. Some patients have increasing opportunities to obtain information through new sources such as the internet, touch-screens, and patient-held records. Others remain poorly informed. OBJECTIVES: To identify learning outcomes for clinicians in meeting patient information needs and working with well-informed patients. DESIGN: Four-stage multicentre multidisciplinary qualitative study. SETTING AND SUBJECTS: (1) Semistructured interviews with 20 clinicians in Glasgow; (2) semistructured interviews with 52 clinicians in Nottingham and London; (3) testing of consensus by postal questionnaire and Delphi method amongst 37 clinicians in medicine, nursing and the professions allied to medicine, and (4) conference to discuss results. RESULTS: 46 learning outcomes were identified in the eight areas of: placing a higher priority on patient information and education; understanding the patient's information needs and environment; understanding the emotional aspects of learning; developing patient understanding; helping patients to understand about health care and health care information; learning from the patient; knowing about information sources and their use, and issues of multidisciplinary working. CONCLUSIONS: The suggested learning outcomes provide the basis for wider discussion, for possible inclusion in curricula both at undergraduate and continuing education levels, and as the basis for the development of new educational materials.

Communication↗

Nurses' use of restraints and their attitudes toward restraint use and the elderly in an acute care setting.

A descriptive correlation study was conducted in an acute-care hospital to explore the relationship between nurses' use of restraints and their attitudes toward restraint use and the elderly. A total of 201 nurses returned a questionnaire that collected demographic information and included two research instruments: (i) Perceptions of Restraint Use Questionnaire and (ii) Attitudes toward the Aged Semantic Differential. Results showed slightly positive attitudes towards the elderly and toward the use of restraints, although there was no correlation between scores on the two scales. Furthermore, nurses' attitudes did not predict their self-reported use of restraints.

Adult↗

Development of the continuous quality improvement questionnaire (CQIQ).

PURPOSE: Increasingly, hospitals are engaging in continuous quality improvement (CQI) endeavors, aimed at optimizing patient care. Physician involvement is critical to the success of such initiatives. Little is known about any mediating factors that affect physician participation in these projects, though such knowledge may be potentially important for targeting approaches to maximize physician involvement. The purpose of this study was to develop a reliable and valid instrument to assess physicians' knowledge of and attitudes toward CQI. MATERIALS AND METHODS: Items for the questionnaire were generated by using interviews and literature re-view and covered areas of knowledge, attitude, and facilitators and barriers to involvement in CQI projects. Five physicians participated in the interviews, 64 participated in the survey, and 9 participated in the assessment of test-retest reliability. Main outcomes were reliability and validity. RESULTS: The CQI questionnaire (CQIQ) had acceptable internal consistency and Cronbach's alpha correlation coefficient exceeded.70 for all scales. Item-total correlation ranged from.30 to.63 for all scales except for 1 item. Pearson's correlation coefficient for test-retest reliability was 0.85 (P =.02). A 76% response rate was achieved. CONCLUSIONS: There appears to be complex interactions among psychologic and environmental mediators that influence physician participation in hospital quality initiatives. The CQIQ shows reasonable measurement properties and our findings should be generalizable to physicians in other academic institutions. The CQIQ provides additional information on the implementation of programs and processes that should be validated in other institutional settings to enhance the interpretability of the instrument.

Adult↗

Validation of the Arizona Activity Frequency Questionnaire using doubly labeled water.

PURPOSE: Physical activity questionnaires (PAQs) are considered the most cost-efficient method to estimate total energy expenditure (TEE) in epidemiological studies. However, relatively few PAQs have been validated using doubly labeled water (DLW) in women or in samples with diverse ethnic backgrounds. This study was conducted to validate the Arizona Activity Frequency Questionnaire (AAFQ) for estimation of TEE and physical activity energy expenditure (PAEE) over 1 month using DLW as a reference method. METHODS: Thirty-five relatively sedentary women completed the AAFQ before participating in an 8-d DLW protocol to measure TEE. TEE and PAEE were estimated from the AAFQ by calculating resting metabolic rate (RMR) using the equation of Mifflin et al. (AAFQmif), by measuring RMR using indirect calorimetry (AAFQic), and using MET conversion (AAFQmet). A predictive equation for TEE was generated. RESULTS: The mean +/- SD for TEE and PAEE from DLW were 9847 +/- 2555 kJ x d(-1) and 5578 +/- 2084 kJ x d(-1), respectively. Formulas using RMR to calculate the TEE and PAEE from the AAFQ tended to underestimate TEE and PAEE, whereas those that included only weight tended to overestimate TEE and PAEE. On the basis of the Mifflin et al. equation, the AAFQ tends to underestimate PAEE by 13%. This underestimation may be explained by the low lean body mass of the sample population and by effectiveness of the METs/RMR ratio in the obese. The following predictive equation was calculated: TEE (kJ x d(-1)) = (86.0 * average total daily METs) + (2.23 * RMRmif) - 6726. When the predictive equation is used, TEE calculated from the AAFQ is highly correlated with DLW TEE (adjusted r(2) = 0.70, P < 0.001). CONCLUSION: The AAFQ is an effective tool for the prediction of TEE and PAEE in epidemiological studies.

Adult↗

Effect of phage on survival of Salmonella enteritidis during manufacture and storage of cheddar cheese made from raw and pasteurized milk.

The ability of Salmonella Enteritidis to survive in the presence of phage, SJ2, during manufacture, ripening, and storage of Cheddar cheese produced from raw and pasteurized milk was investigated. Raw milk and pasteurized milk were inoculated to contain 10(4) CFU/ml of a luminescent strain of Salmonella Enteritidis (lux) and 10(8) PFU/ml SJ2 phage. The milks were processed into Cheddar cheese following standard procedures. Cheese samples were examined for Salmonella Enteritidis (lux), lactic acid bacteria, molds and yeasts, coliforms, and total counts, while moisture, fat, salt, and pH values were also measured. Salmonella Enteritidis (lux) was enumerated in duplicate samples by surface plating on MacConkey novobiocin agar. Bioluminescent colonies of Salmonella Enteritidis were identified in the NightOwl molecular imager. Samples were taken over a period of 99 days. Counts of Salmonella Enteritidis (lux) decreased by 1 to 2 log cycles in raw and pasteurized milk cheeses made from milk containing phage. In cheeses made from milks to which phage was not added, there was an increase in Salmonella counts of about 1 log cycle. Lower counts of Salmonella Enteritidis (lux) were observed after 24 h in pasteurized milk cheese containing phage compared to Salmonella counts in raw milk cheese with phage. Salmonella Enteritidis (lux) survived in raw milk and pasteurized milk cheese without phage, reaching a final concentration of 10(3) CFU/g after 99 days of storage at 8 degrees C. Salmonella did not survive in pasteurized milk cheese after 89 days in the presence of phage. However, Salmonella counts of approximately 50 CFU/g were observed in raw milk cheese containing phage even after 99 days of storage. In conclusion, this study demonstrates that the addition of phage may be a useful adjunct to reduce the ability of Salmonella to survive in Cheddar cheese made from both raw and pasteurized milk.

Animals↗

Utilization of herpes simplex PCR assays for cerebrospinal fluid in a pediatric health care setting.

An assessment was made of the utilization and impact of a diagnostic polymerase chain reaction (PCR) assay for the diagnosis of herpes simplex viruses (HSV) 1 and 2 in cerebrospinal fluid of children who attended a Canadian pediatric referral centre. One hundred and three assays were performed on specimens from 103 patients during the period August 1997 to September 1998. Patient ages ranged from newborn to 16 years. Indications for HSV PCR included seizures with or without fever (56.3%), aseptic meningitis (16.5%), and encephalopathy with or without fever (10.7%). Only 2 of 103 (1.9%) assays were positive, including one each for HSV1 and HSV2. Control specimens that were seeded with virus indicated inhibition for 24.3, 8.8, and 6.8% of assays for HSV1, HSV2, and both HSV1 and HSV2, respectively. The mean turn-around time for HSV PCR was 2.5 days, and 90.3% were completed in less than 5 days. Acyclovir was administered to 78.6% of the patients overall; the results of the HSV PCR impacted on the treatment courses for 36 individuals. Nevertheless, 16.5% of patients continued to receive extended courses of antiviral therapy despite negative HSV PCR assays. Although it is desirable to decrease the frequency of PCR inhibitions and to further decrease the interval to assay completion, HSV PCR does have a significant impact on antiviral use in this setting.

Adolescent↗

Absence of zidovudine resistance in antiretroviral-naive patients following zidovudine/lamivudine/protease inhibitor combination therapy: virological evaluation of the AVANTI 2 and AVANTI 3 studies.

OBJECTIVES: To assess the role of resistance mutations in subjects experiencing virological failure on zidovudine (ZDV) and lamivudine (3TC) combined with a protease inhibitor (PI) to those failing on ZDV/3TC alone. DESIGN AND METHODS: Samples were obtained from previously antiretroviral therapy-naive subjects enrolled into two studies, AVANTI 2 and AVANTI 3. Subjects were randomized to receive either: ZDV/3TC or ZDV/3TC plus indinavir (IDV) for 52 weeks (AVANTI 2), and ZDV/3TC or ZDV/3TC and nelfinavir (NFV) for 28 weeks (AVANTI 3). Emergence of viral resistance mutations was monitored by population sequencing and phenotypic resistance was determined by the recombinant virus assay. RESULTS: Genotypic data were obtained for subjects with plasma HIV-1 RNA > 400 copies/ml. In AVANTI 2, ZDV mutations were detected in 27% of ZDV/3TC-treated patients at week 52, but were absent in subjects treated with ZDV/3TC/IDV. No subjects from either arm of AVANTI 3 developed ZDV resistance mutations at week 28. The M184V mutation developed in most ZDV/3TC-treated subjects from both studies. The presence of M184V was, however, associated with significantly lower plasma viral RNA levels when compared with values obtained before initiation of treatment. There was a high frequency (4 of 11) of the protease L10F substitution in ZDV/3TC/IDV-treated patients that was associated with virological failure but did not result in phenotypic resistance to any of the PIs tested. CONCLUSIONS: ZDV mutations were not detected in ZDV/3TC/PI-treated patients and they developed slowly in those treated with ZDV/3TC. Few protease mutations known to confer phenotypic PI resistance developed in the ZDV/3TC/PI arms of either study. The low prevalence of ZDV and PI mutations is encouraging regarding the future treatment options of these patients.

Adult↗

Metalloproteinases: role in breast carcinogenesis, invasion and metastasis.

The matrix metalloproteinases (MMPs) are a family of zinc-dependent endopeptidases. Their primary function is degradation of proteins in the extracellular matrix. Currently, at least 19 members of this family are known to exist. Based on substrate specificity and domain organization, the MMPs can be loosely divided into four main groups: the interstitial collagenases, gelatinases, stromelysins and membrane-type MMPs. Recent data from model systems suggest that MMPs are involved in breast cancer initiation, invasion and metastasis. Consistent with their role in breast cancer progression, high levels of at least two MMPs (MMP-2 and stromelysin-3) have been found to correlate with poor prognosis in patients with breast cancer. Because MMPs are apparently involved in breast cancer initiation and dissemination, inhibition of these proteinases may be of value both in preventing breast cancer and in blocking metastasis of established tumours

Apoptosis↗

Course of viral load throughout HIV-1 infection.

HIV-1 RNA levels are routinely monitored as part of patient management. However, little is known about the course of HIV-1 RNA levels over the entire period of infection. The aim of this study was to investigate the course of HIV-1 RNA levels in a cohort of men with hemophilia who were observed for up to 17 years after HIV-1 seroconversion, and to assess the risk of HIV disease progression at any HIV-1 RNA level. Viral loads were measured on annual stored serum samples in 107 men with hemophilia A using the Roche Amplicor Monitor assay with non-B primers. On average, HIV-1 RNA levels increased significantly by 0.11 log10 per year over the course of HIV infection. This rate of increase was significantly faster in those who developed AIDS or died over the subsequent 12 to 17 year period, and in those who were older at HIV- 1 seroconversion. The risk of developing AIDS and death remained low when the HIV-1 RNA level was below 4 log10 copies/ml, but increased rapidly thereafter, supporting current guidelines for the initiation of antiretroviral therapy after the viral load has exceeded this level.

CD4 Lymphocyte Count↗

Magnetic resonance imaging volumes of the hippocampus and the amygdala in women with borderline personality disorder and early traumatization.

BACKGROUND: Based on findings of stress-induced neural disturbances in animals and smaller hippocampal volumes in humans with posttraumatic stress disorder), we hypothesized that patients with borderline personality disorders (BPD), who often are victims of early traumatization, have smaller volumes of the hippocampus and the amygdala. We assumed that volumes of these brain regions are negatively correlated with traumatic experiences and with neuropsychological deficits. METHODS: We studied 21 female patients with BPD and a similar group of healthy controls. We performed clinical assessments, a modified version of the Childhood Trauma Questionnaire, and magnetic resonance imaging volumetric measurements of the hippocampus, amygdala, temporal lobes, and prosencephalon. Neuropsychological testing included scales on which disturbances in BPD were previously reported. RESULTS: The patients with BPD had nearly 16% smaller volumes of the hippocampus (P<.001) and 8% smaller volumes of the amygdala (P<.05) than the healthy controls. The results for both hemispheres were nearly identical and were controlled for the volume of the prosencephalon and for head tilts. The volumes of the hippocampus were negatively correlated with the extent and the duration of self-reported early traumatization only when BPD and control subjects were considered together. Levels of neuropsychological functioning were associated with the severity of depression but not with the volumes of the hippocampus. CONCLUSION: In female patients with BPD, we found reduction of the volumes of the hippocampus (and perhaps of the amygdala), but the association of volume reduction and traumatic experiences remains unclear. Arch Gen Psychiatry. 2000;57:1115-1122.

Adult↗

The impact of expanding the numbers of clinical nurse specialists in cancer care: a United Kingdom case study.

In the last few years there has been an increase in the number of clinical nurse specialists (CNSs) working in cancer care throughout the UK. This paper examines the issues raised by the proliferation of site-specific cancer CNS posts, developed to give a 'nursing lead' for a particular tumour type. The issues common to all CNS posts are exacerbated when a number of specialists are involved in the cancer journey, causing potential fragmentation and confusion. Key issues need to be addressed if the role is to remain credible, and ensure clarity for patients and the multiprofessional team. These include role clarification, sensitive integration, interface with other cancer CNSs and the multiprofessional team, evaluation, cost, education and training, recruitment and succession planning and the 'career cul-de-sac'. Cancer nursing's response to these challenges will set the professional agenda for education, training and future models of service delivery.

Journal Article↗

Evening primrose oil and borage oil in rheumatologic conditions.

Diets rich in arachidonic acid (20:4n-6) lead to the formation of 2-series prostaglandins (PGs) and 4-series leukotrienes (LTs), with proinflammatory effects. Nonsteroidal antiinflammatory drugs are used in rheumatoid arthritis to inhibit cyclooxygenase (prostaglandin-endoperoxide synthase), thereby decreasing production of 2-series PGs. Lipoxygenase activity remains intact, however, allowing LT production (eg, synthesis of LTB(4), a potent inflammatory mediator) to continue. Altering the essential fatty acid (EFA) content of the diet can modify some of these effects. Ingestion of a diet rich in evening primrose oil elevates concentrations of dihomo-gamma-linolenic acid (DGLA; 20:3n-6), which results in the production of 1-series PGs, eg, PGE(1). DGLA itself cannot be converted to LTs but can form a 15-hydroxyl derivative that blocks the transformation of arachidonic acid to LTs. Increasing DGLA intake may allow DGLA to act as a competitive inhibitor of 2-series PGs and 4-series LTs and thus suppress inflammation. The results of in vitro and animal work evaluating EFAs in inflammatory situations are encouraging, which has stimulated clinical workers to evaluate these compounds in rheumatoid arthritis. Several well-controlled, randomized clinical studies have now been completed in which various EFAs were evaluated as treatments. The results of most of these studies suggest some clinical benefit to these treatments; these data are reviewed here.

Anti-Inflammatory Agents, Non-Steroidal↗

Personnel exposure during gamma endovascular brachytherapy.

PURPOSE: The use of 192Ir brachytherapy for the treatment of in-stent restenosis of the coronary arteries has shown promising clinical results. This paper investigates the radiation exposure of catheterization laboratory staff associated with the performance of this procedure. METHODS AND MATERIALS: Cath lab staff were monitored using personal monitors (shielded against fluoroscopic x-rays) during the performance of eleven cases using nominal 10 GBq 192Ir sources. Staff positions in the lab were simultaneously tracked by video cameras. Direct measurements were also made using a survey meter. Treatments were administered in a conventional cardiac-catheterization-laboratory. RESULTS: The dosimeter readings were analyzed in combination with the radiation survey and time motion survey. Brachytherapy procedural times for the cardiologist, oncologist, physicist, and angiographic assistants were, respectively, 26 +/- 24, 401 +/- 132, 486 +/- 148, and 7 +/- 13 s per case (mean +/- standard deviation). Readings of the personnel monitors were low. Credible upper limits of the respective doses are estimated to be less than 10, 10, 7, and 5 microSv per procedure. Auxiliary shields reduced the dose to individuals located outside of the catheterization laboratory to less than 0.5 microSv per procedure. CONCLUSIONS: The average radiation dose received by laboratory personnel during a representative 192Ir endocoronary brachytherapy procedure is estimated to be less than 0.1% of the NCRP recommended annual radiation worker's Maximum Permissible Dose (1% of the general public's MPD). This level is justifiable as long as the use of 192Ir benefits patients by producing an improved clinical outcome relative to the use of a less penetrating radionuclide or the application of alternative therapies. Further optimization of the delivery procedure is expected to reduce staff dose.

Brachytherapy↗