Killing controversy.
How do neutrophils kill pathogens? A 1967 paper by Seymour Klebanoff provided a neat answer. But far from being resolved, the question still provokes vehement arguments.
Animals↗
Biomedical subjects
Ruth Williams
Publications and source records attributed to Ruth Williams.
Escape from fatal fusion.
In 1971, a seminal paper from the laboratory of Philip D'Arcy Hart reported that the intracellular pathogen Mycobacterium tuberculosis avoids destruction in the cell's lysosomes by avoiding these organelles altogether-a trick now known to be used by many other intracellular pathogens.
Animals↗
The causal role of negative imagery in social anxiety: a test in confident public speakers.
This study tests the causal role of negative self-imagery in social anxiety. Low public-speaking anxious volunteers rehearsed a negative self-image, a positive self-image or a control image prior to giving a speech. As predicted, the negative image group felt more anxious, believed they performed less well and reported more negative thoughts than the positive image group. These findings do not appear to be due to changes in state anxiety, since they remained unchanged when anxiety was controlled in an analysis of covariance. The negative image group also reported more anxiety than the control group. Given that participants do not currently have anxiety problems, the findings are consistent with the idea that negative self-imagery has a causal role in the development and maintenance of social anxiety.
Affect↗
A report on economic studies of Australian mental health issues.
OBJECTIVE: To report on economic studies of Australian mental health issues. CONCLUSION: Although the international literature on the economics of mental health issues is increasing, and although many Australian studies exist on one comorbid condition of mental illness, namely substance abuse, there are very few empirical studies by economists of Australia's mental health issues.
Alcoholism↗
Histone hypomethylation is an indicator of epigenetic plasticity in quiescent lymphocytes.
Post-translational modifications of histone amino termini are thought to convey epigenetic information that extends the coding potential of DNA. In particular, histone lysine methylation has been implicated in conveying transcriptional memory and maintaining lineage fidelity. Here an analysis of histone lysine methylation in quiescent (G(0)) and cycling lymphocytes showed that methylation of histone H3 at lysines 4 (H3K4), 9 (H3K9), 27 (H3K27) and histone H4 at lysine 20 is markedly reduced in resting B lymphocytes as compared with cycling cells. Quiescent B cells also lacked heterochromatin-associated HP1beta and Ikaros at pericentric chromatin and expressed low levels of Ezh2 and ESET histone methyl transferases (HMTases). Nuclei from resting B or T cells were approximately three times more efficiently reprogrammed in nuclear transfer assays than cells in which HMTase expression, histone methylation and HP1beta binding had been restored following mitotic stimulation. These results showing local and global changes in histone lysine methylation levels in vivo demonstrate that constitutive heterochromatin organization is modified in resting lymphocytes and suggest that histone hypomethylation is a useful indicator of epigenetic plasticity.
Animals↗
Oral glutamine supplementation decreases resting energy expenditure in children and adolescents with sickle cell anemia.
OBJECTIVES: To determine the effects of orally administered glutamine on the resting energy expenditure (REE) and nutritional status of children and adolescents with sickle cell anemia. METHODS: Twenty-seven children and adolescents (13 boys, 14 girls), 5.2 to 17.9 years old (median 11.0 years), received orally administered glutamine (600 mg/kg per day) for 24 weeks. Measures of REE and other nutritional parameters were compared at baseline and 24 weeks. RESULTS: After 24 weeks, the patients' median REE (kcal/d) decreased by 6% (P = 0.053) as indicated by the Harris Benedict equations and by 5% (P = 0.049) as indicated by the modified equations. Patients with less than 90% ideal body weight had even greater declines in REE after 24 weeks (P < 0.03 and 0.02, respectively). Improvements in nutrition parameters and in two amino acids in the plasma were observed. CONCLUSIONS: After 24 weeks of orally administered glutamine, children and adolescents with sickle cell anemia had a decrease in REE and improvement in nutritional parameters. Those who were underweight had a greater decrease in REE than those of normal body weight. Lowering REE may be an effective way to improve the growth of these children and adolescents.
Administration, Oral↗
Self-images play a causal role in social phobia.
Patients with social phobia often experience negative self-images in social situations. The current study investigated whether negative self-images have a causal role in maintaining social phobia. Patients with social phobia participated twice in a conversation with a stranger, once whilst holding their usual negative self-image in mind and once whilst holding a less negative (control) self-image in mind, with order counterbalanced across participants. Compared to the control image condition, when participants held the negative image in mind they experienced greater anxiety, rated their anxiety symptoms as being more visible, and rated their performance as poorer. An assessor who did not know which image was being held also rated participants' anxiety as more evident and their behaviour as less positive when the negative image was being held in mind. Finally, when participant and assessor ratings were compared, participants underestimated their performance and overestimated the visibility of their anxiety to a significantly greater extent in the negative imagery condition. Taken together, these results support the hypothesis that negative self-imagery has a causal role in maintaining social phobia.
Adult↗
Comparison of energy prediction equations with measured resting energy expenditure in children with sickle cell anemia.
OBJECTIVE: To determine the accuracy of energy prediction equations when compared with measured resting energy expenditure (REE) in children with sickle cell anemia. To develop a modified equation that more accurately estimates the energy needs of children with sickle cell anemia and to cross-validate these on a different set of patients (test patients). DESIGN: REE was measured in children using indirect calorimetry and compared with predicted values using the Harris-Benedict and the Food and Agriculture Organization/World Health Organization/United Nations University equations (WHO). SUBJECTS/SETTING: Eighteen patients participated in the original sample that compared predicted with measured energy expenditure. The modified equations were developed using the original 18 patients. A test population of 20 different patients was used to validate the modified equations. STATISTICAL ANALYSIS: Wilcoxon signed-rank test was performed to compare measured with predicted REE. The correlation analysis method and multiple linear regression method were used to develop 2 modified versions for the Harris-Benedict and WHO prediction equations. RESULTS: When compared with the mean predicted REE using the Harris-Benedict and WHO equations, the mean measured REE was 14% and 12% greater than both (P=.005 and P=.014, respectively). Two modified equations were developed from the Harris-Benedict and WHO equations. Based on the data from the test patients, the mean measured REE was 15% greater than the mean predicted REE based on the Harris-Benedict and WHO equations (P=.0001 for both). When the modified Harris-Benedict and WHO equations were used, there was almost no difference in the mean measured REE and the mean predicted REE (mean difference using Harris-Benedict = 14, P = .9273; mean difference using WHO = -13, P = .6215). CONCLUSION: Both energy prediction equations underestimated REE in children with sickle cell anemia. The 2 modified versions of the energy prediction equations that we propose predicted the energy needs of these children much more accurately; however, the modified equations need to be validated through application to other children with sickle cell anemia.
Analysis of Variance↗
Evidence for a role of Langerhans cell-derived IL-16 in atopic dermatitis.
BACKGROUND: The factors controlling infiltration of inflammatory cells into atopic dermatitis (AD) lesions remain to be fully explored. Recently, epidermal cells in lesional AD were reported to contain increased messenger (m)RNA levels of IL-16, a cytokine that induces chemotactic responses in CD4(+)T cells, monocytes, and eosinophils. OBJECTIVES: We sought to determine the expression of IL-16 in epidermal cells in normal skin and skin from AD lesions and to investigate whether Langerhans cell (LC)-derived IL-16 may contribute to the initiation of atopic eczema. METHODS: The cutaneous expression of IL-16 was investigated by in situ hybridization and immunohistochemistry. Expression of IL-16 was also investigated in freshly isolated LCs and in keratinocytes by intracellular cytokine staining, quantitative real-time RT-PCR, and ELISA. RESULTS: Low levels of IL-16 mRNA, but no stored IL-16 protein, were detected in keratinocytes and LCs isolated from normal skin. Synthesis, storage, and secretion of IL-16 could be induced in LCs, but not keratinocytes, by activation with phorbol ester and ionomycin. In normal skin (n = 10) neither keratinocytes nor LCs expressed IL-16. In contrast, IL-16 was contained in approximately 40% of CD1a(+)LCs in patients with active AD (n = 16). IL-16 expression in LCs in patients with AD correlated with the number of infiltrating CD4(+)cells (r =.72, P =.0017) and was completely downregulated parallel to the clinical response of AD lesions to topical treatment with FK506. CONCLUSION: LC-derived IL-16 may participate in the recruitment and activation of inflammatory cells in AD.
Antibodies, Monoclonal↗
Patterns and energy expenditure of free-living physical activity in adolescents with sickle cell anemia.
OBJECTIVE: Our purpose was to examine the relationship between physical activity (PA), PA-associated energy expenditure (PAEE), and total daily energy expenditure (TEE) in free-living adolescents with sickle-cell anemia (SCA). STUDY DESIGN: Adolescents with SCA (n = 28) were matched for sex and age with 22 healthy control participants. PA was measured for 6 to 8 consecutive days with a triaxial accelerometer and resting energy expenditure (REE) by whole-room indirect calorimetry. TEE was calculated by summing PAEE and REE. RESULTS: TEE was similar, REE was higher (difference, 209 kcal x day(-1); P =.0001), and PAEE was lower (difference, 657 kcal x day(-1); P <.001) in patients with SCA than in control participants. In SCA, there was a positive linear relationship between PAEE and hemoglobin concentration (r (2) = 0.583). Time spent in PA of moderate and high intensity was lower in patients with SCA than in control participants (18 +/- 22 vs 48 +/- 31 min/d; P <.0001). CONCLUSION: In adolescents with SCA under free-living conditions, there is a significant intra and interindividual variability in the amount of PA, PAEE, and PA patterns. Because of a lower PAEE and a higher REE, TEE is similar in adolescents with SCA and healthy adolescents. An association of PAEE with hemoglobin concentration may be a part of an energy saving compensatory mechanism in SCA.
Adolescent↗
Establishing the use of body mass index as an indicator of nutrition risk in children with cancer.
BACKGROUND: The negative health consequences of malnutrition in the pediatric oncology patient are well known. The purpose of this study was to determine the usefulness of body mass index (BMI) for age as a tool to prospectively identify pediatric cancer patients at risk for malnutrition and to determine the BMI percentile that would be required to identify at-risk patients. METHODS: This study was conducted by a retrospective chart review of 1839 newly diagnosed acute lymphoblastic leukemia patients at St. Jude Children's Research Hospital. Those falling below the 10(th) percentile on any one category of height for age (HFA), weight for age (WFA), or weight for height (WFH) were classified with regard to nutrition risk and compared with those identified as at risk by BMI for age (BFA). The BMI percentiles of the lower 9(th)-11(th) percentile patients on the HFA, WFA, and WFH growth charts were averaged in an attempt to determine a useful value to identify nutrition risk. RESULTS: Lack of agreement was found to exist between BFA and HFA in identifying patients at risk for malnutrition, and also between BFA and WFA. Significant agreement was found to exist between BFA and WFH. The BMI percentile required to identify those at risk for malnutrition by the other growth charts would classify too many patients as being at risk for malnutrition to be considered clinically useful. CONCLUSIONS: Although research has shown BMI is appropriate to use in the nutrition assessment of children, its usefulness has not been confirmed in the pediatric oncology patient; therefore, further study is warranted. BFA assessment should be included in the nutrition survey of new pediatric oncology patients, along with other parameters, but it cannot be recommended as the sole indicator of nutrition status at this time.
Adolescent↗
A comparison of calorie and protein intake in hospitalized pediatric oncology patients dining with a caregiver versus patients dining alone: a randomized, prospective clinical trial.
Hospitalization and cancer therapy can contribute to decreased food intake in children and adolescents with cancer, making it a challenge to meet their nutritional needs. The affect of hospitalization and the eating environment for pediatric oncology patients has not been studied very well, and the effect of altering the social aspect of mealtime for hospitalized pediatric oncology patients has not been studied at all. The authors conducted a randomized, prospective clinical trial to determine if hospitalized pediatric oncology patients consume more protein and calories when eating with a family member or when eating alone in their room at mealtime. All food and beverage intake was recorded for 3 consecutive days, and a food service satisfaction survey was completed on Day 3. Food records were analyzed for calorie and protein intake, and surveys were analyzed for patient/parent satisfaction. The study was completed by 200 hospitalized patients and their parent/caregiver. Overall, neither calorie nor protein intake differed significantly between the two groups, but patient/parent satisfaction was significantly higher in the group of patients who dined with their caregiver. By using analysis of variance, the authors found that ideal body weight and years of sickness were significantly associated with calorie and protein intake.
Adolescent↗
Government policy and older people.
Older people are the main users of health and social care services, but services have not always adequately addressed need (Department of Health, 2001). The past 50 years have witnessed many changes and reforms in health and the social welfare state that have directly affected older people and the level and type of help and support they can expect from the state. Nurses need to understand these changes, as the implications of policy development will have a direct impact on the people we are working with. Nurses also have a part to play in shaping and informing policy development.
Aged↗