Index of sources of stress in nursing students: a confirmatory factor analysis.

Aim. This paper is a report of a study to test the proposed factor structure of the Index of Sources of Stress in Nursing Students. Background. Research across many countries has identified a number of sources of distress in nursing students but little attempt has been made to understand and measure sources of eustress or those stressors likely to enhance performance and well-being. The Index of Sources of Stress in Nursing Students was developed to do this. Exploratory factor analysis suggested a three-factor structure, the factors being labelled: learning and teaching; placement-related and course organization. It is important, however, to subject the instrument to confirmatory factor analysis as a further test of construct validity. Method. A convenience sample of final year nursing students (n = 176) was surveyed in one university in Northern Ireland in 2007. The Index of Sources of Stress in Nursing Students, which measures sources of stress likely to contribute to distress and eustress, was completed electronically. The LISREL programme was used to carry out the confirmatory factor analysis and test the factor structure suggested in the exploratory analysis. Findings. The proposed factor structure for the items measuring ‘Uplifts’ proved to be a good fit to the data and the proposed factor structure for the items measuring ‘Hassles’ showed adequate fit. Conclusion. In nursing programmes adopting the academic model and combining university-based learning with placement experience, this instrument can be used to help identify the sources of stress or course demands that students rate as distressing and those that help them to achieve. The validity of the ISSN could be further evaluated in other education settings.

Association between breastfeeding and anthropometry and cardiovascular disease risk factor status in adolescence and young adulthood: the Young Hearts Project, Northern Ireland.

Objective: To examine the association between breastfeeding and blood pressure, anthropometry, and plasma lipid profile in both adolescence and young adulthood. Design: Longitudinal study of biological and behavioural risk factors for cardiovascular disease. Setting: The Young Hearts Project, Northern Ireland Subjects: School children aged 12 years and 15 years who participated in a cross-sectional study of lifestyle and health, and who were followed up as young adults aged 20 – 25 years. Results: There was no significant difference in height, weight, BMI, skin-fold thickness measurements, blood pressure or plasma lipid profile in adolescents who had been breastfed when compared to those who had not been breastfed. However, by the time these adolescents had reached adulthood, those who had been breastfed were significantly taller when compared to those who had not been breastfed (standing height, P=0.013; leg length (P=0.035)). Specifically, the breastfed group were on average taller by 1.7cm (95% CI 0.4, 3.0) and had longer legs by 1cm (95% CI 0.1, 1.9). There was no significant difference in other anthropometric measures, blood pressure or plasma lipid profile in adults who had been breastfed when compared to those who had not been breastfed. Conclusions: Compared with those who had not been breastfed, individuals who had been breastfed were taller in adulthood. Given the known association of increased adult height with improved life expectancy the results from this study support a beneficial effect of breastfeeding.

Comparative analysis of dna methylation profiles in peripheral blood leukocytes versus lymphoblastoid cell lines

Previous reports have shown that DNA methylation profiles within primary human malignant tissues are altered when these cells are transformed into cancer cell lines. However, it is unclear if similar differences in DNA methylation profiles exist between DNA derived from peripheral blood leukocytes (PBLs) and corresponding Epstein-Barr Virus transformed lymphoblastoid cell lines (LCLs). To assess the utility of LCLs as a resource for methylation studies we have compared DNA methylation profiles in promoter and 5' regions of 318 genes in PBL and LCL sample pairs from patients with type 1 diabetes with or without nephropathy. We identified a total of 27 (similar to 8%) genes that revealed different DNA methylation profiles in PBL compared with LCL-derived DNA samples. In conclusion, although the profiles for most promoter regions were similar between PBL-LCL pairs, our results indicate that LCL-derived DNA may not be suitable for DNA methylation studies at least in diabetic nephropathy.

Regulation and consequences of differential gene expression in diabetic kidney disease

DIN (diabetic nephropathy) is the leading cause of end-stage renal disease worldwide and develops in 25-40% of patients with Type 1 or Type 2 diabetes mellitus. Elevated blood glucose over long periods together with glomerular hypertension leads to progressive glomerulosclerosis and tubulointerstitial fibrosis in susceptible individuals. Central to the pathology of DIN are cytokines and growth factors such as TGF-beta (transforming growth factor beta) superfamily members, including BMPs (bone morphogenetic protein) and TGF-beta 1, which play key roles in fibrogenic responses of the kidney, including podocyte loss, mesangial cell hypertrophy, matrix accumulation and tubulointerstitial fibrosis. Many of these responses can be mimicked in in vitro models of cells cultured in high glucose. We have applied differential gene expression technologies to identify novel genes expressed in in vitro and in vivo models of DN and, importantly, in human renal tissue. By mining these datasets and probing the regulation of expression and actions of specific molecules, we have identified novel roles for molecules such as Gremlin, IHG-1 (induced in high glucose-1) and CTGF (connective tissue growth factor) in DIN and potential regulators of their bioactions.

The impact of dose escalation and resistance modulation in older patients with acute myeloid leukaemia and high risk myelodysplastic syndrome: the results of the LRF AML14 trial.:the results of the LRF AML14 trial

The acute myeloid leukaemia (AML)14 trial addressed four therapeutic questions in patients predominantly aged over 60 years with AML and High Risk Myelodysplastic Syndrome: (i) Daunorubicin 50 mg/m(2) vs. 35 mg/m(2); (ii) Cytarabine 200 mg/m(2) vs. 400 mg/m(2) in two courses of DA induction; (iii) for part of the trial, patients allocated Daunorubicin 35 mg/m(2) were also randomized to receive, or not, the multidrug resistance modulator PSC-833 in a 1:1:1 randomization; and (iv) a total of three versus four courses of treatment. A total of 1273 patients were recruited. The response rate was 62% (complete remission 54%, complete remission without platelet/neutrophil recovery 8%); 5-year survival was 12%. No benefits were observed in either dose escalation randomization, or from a fourth course of treatment. There was a trend for inferior response in the PSC-833 arm due to deaths in induction. Multivariable analysis identified cytogenetics, presenting white blood count, age and secondary disease as the main predictors of outcome. Although patients with high Pgp expression and function had worse response and survival, this was not an independent prognostic factor, and was not modified by PSC-833. In conclusion, these four interventions have not improved outcomes in older patients. New agents need to be explored and novel trial designs are required to maximise prospects of achieving timely progress.

Inhibition of Advanced Glycation and Absence of Galectin-3 Prevent Blood-Retinal Barrier Dysfunction during Short-Term Diabetes

Breakdown of the inner blood-retinal barrier (iBRB) occurs early in diabetes and is central to the development of sight-threatening diabetic macular edema (DME) as retinopathy progresses. In the current study, we examined how advanced glycation end products (AGEs) forming early in diabetes could modulate vasopermeability factor expression in the diabetic retina and alter inter-endothelial cell tight junction (TJ) integrity leading to iBRB dysfunction. We also investigated the potential for an AGE inhibitor to prevent this acute pathology and examined a role of the AGE-binding protein galectin-3 (Gal-3) in AGE-mediated cell retinal pathophysiology. Diabetes was induced in C57/BL6 wild-type (WT) mice and in Gal-3(-/-) transgenic mice. Blood glucose was monitored and AGE levels were quantified by ELISA and immunohistochemistry. The diabetic groups were subdivided, and one group was treated with the AGE-inhibitor pyridoxamine (PM) while separate groups of WT and Gal-3(-/-) mice were maintained as nondiabetic controls. iBRB integrity was assessed by Evans blue assay alongside visualisation of TJ protein complexes via occludin-1 immunolocalization in retinal flat mounts. Retinal expression levels of the vasopermeability factor VEGF were quantified using real-time RT-PCR and ELISA. WT diabetic mice showed significant AGE -immunoreactivity in the retinal microvasculature and also showed significant iBRB breakdown (P < .005). These diabetics had higher VEGF mRNA and protein expression in comparison to controls (P < .01). PM-treated diabetics had normal iBRB function and significantly reduced diabetes-mediated VEGF expression. Diabetic retinal vessels showed disrupted TJ integrity when compared to controls, while PM-treated diabetics demonstrated near-normal configuration. Gal-3(-/-) mice showed significantly less diabetes-mediated iBRB dysfunction, junctional disruption, and VEGF expression changes than their WT counterparts. The data suggests an AGE-mediated disruption of iBRB via upregulation of VEGF in the diabetic retina, possibly modulating disruption of TJ integrity, even after acute diabetes. Prevention of AGE formation or genetic deletion of Gal-3 can effectively prevent these acute diabetic retinopathy changes.

FLEXIBLE OMNIVORY IN DIKEROGAMMARUS VILLOSUS (SOWINSKY, 1894) (AMPHIPODA) - AMPHIPOD PILOT SPECIES PROJECT (AMPIS) REPORT 5

Feeding in Dikerogammarus villosus (Sowinsky, 1894) males was observed in the field and recorded on video in the laboratory. The following feeding modes were recognized: detritus feeding, grazing, particle feeding, coprophagy, predation on benthic and free swimming invertebrates, predation on fish eggs and larvae, as well as feeding on byssus threads of the zebra mussel, Dreissena polymorpha (Pallas, 1771). The feeding methods are described and illustrated with screenshots of video recordings. The very flexible feeding modes of D. villosus, which make diet switches possible, form a trait that must be an important factor in the invasion success of this Ponto-Caspian gammaridean species, and may thus explain for a great deal its high ecosystem impact.

Influence of penetration enhancers on topical delivery of 5-aminolevulinic acid from bioadhesive patches

Objectives The inclusion 01 chemical penetration enhancers in a novel patch-based system for the delivery of 5-aminolevulinic acid (ALA) was examined in vitro and in vivo. Poor penetration of ALA has been implicated as the primary factor for low response rates achieved with topical ALA-based photodynamic therapy of thicker neoplastic lesions. such as nodular basal cell carcinomas.

An Ecological Correlation Study of Late Age-Related Macular Degeneration and the Complement Factor H Y402H Polymorphism

PURPOSE:
To investigate whether variation in the distribution of the risk allele frequency of the Y402H single-nucleotide polymorphism (SNP) across various ethnicities and geographic regions reflects differences in the prevalence of late age-related macular degeneration (AMD) in those ethnicities.

METHODS:
Published data were obtained via a systematic search. Study samples were grouped into clusters by ethnicity and geographic location and the Spearman correlation coefficient of the prevalence of late AMD and risk allele frequencies was calculated across clusters.

RESULTS:
Across all ethnicities, AMD prevalence was seen to increase with age. Populations of European descent had both higher risk allele frequencies and prevalence of late AMD than did Japanese, Chinese, and Hispanic descendants. Results for African descendants were anomalous: although allele frequency was similar to that in European populations, the age-specific prevalence of late AMD was considerably lower. The correlation coefficient for the association between allele frequency and AMD prevalence was 0.40 (95% confidence interval [CI] = -0.36 to 0.84, P = 0.28) in all populations combined and 0.71 (95% CI = 0.02-0.94, P = 0.04) when people of African descent were excluded.

CONCLUSIONS:
Evidence was found at the population level to support a positive association between the Y204H risk allele and the prevalence of AMD after exclusion of studies undertaken on persons of African ancestry. Data in African, Middle Eastern, and South American populations are needed to provide a better understanding of the association of late AMD genetic risk across ethnicities.

Leptin concentrations in maternal serum and cord blood in diabetic and nondiabetic pregnancy

OBJECTIVE: The purpose of this study was to examine the relationships between maternal and cord leptin concentrations, maternal and neonatal outcomes, and measures of glycemic control in diabetic and nondiabetic pregnancy.

Involvement of MAPKs in endostatin-mediated regulation of blood-retinal barrier function

Purpose: This study aimed to evaluate the effects of endostatin on tight junction (TJ) integrity in retinal microvascular endothelial cells (RMECs) in vitro and in vivo. Moreover, it was hypothesized that endostatin-induced occludin upregulation regulated VEGF(165)-mediated increases in endothelial cell permeability and involved activation of the MAPK signaling cascade. Endostatin is a 20-kDa fragment of collagen XVIII that has been shown to be efficacious in the eye by preventing retinal neovascularization. Endostatin is a specific inhibitor of endothelial cell proliferation, migration, and angiogenesis and has been reported to reverse VEGF-mediated increases in vasopermeability and to promote integrity of the blood-retinal barrier (BRB). In order to determine the mechanism of endostatin action on BRB integrity, we have examined the effects of endostatin on a number of intracellular pathways implicated in endothelial cell physiology. Methods: C57/Bl6 mice were injected with VEGF(165) and/or endostatin, and the distribution of occludin staining was determined using retinal flatmounts. Western blot analysis of RMECs treated with VEGF(165) and/or endostatin was used to determine changes in occludin expression and p38 MAPK and extracellular regulated kinase (ERK1/ERK2 MAPK) activation, while FD-4 flux across the RMEC monolayer was used to determine changes in paracellular permeability. Results: Endostatin prevented the discontinuous pattern of occludin staining observed at the retinal blood vessels of mice administered an intraocular injection of VEGF(165). It was shown that endostatin activated p38 MAPK 5 min after addition to RMECs and continued to do so for approximately 30 min. Endostatin was also shown to activate ERK1/ERK2 5 min after addition and continued to do so, albeit with less potency, up to and including 15 min after addition. Inhibition of p38 MAPK and ERK1/ERK2 prevented endostatin's ability to upregulate levels of occludin expression. Inhibition of these key signaling molecules was shown to prevent endostatin's ability to protect against VEGF(165)- mediated increases in paracellular permeability in vitro. However, it appears that p38 MAPK may play a more important role in VEGF-mediated permeability, as inhibition of ERK1/ERK2 will not prevent VEGF(165)- mediated permeability compared with control ( untreated) cells or cells treated with both a p38 MAPK inhibitor and VEGF(165). Conclusions: Occludin is important for the maintenance of tight junction integrity in vivo. In a p38 MAPK and ERK1/ERK2 dependent manner, endostatin was shown to upregulate the levels of expression of the tight junction protein occludin. Inhibition of these key MAPK components may prevent endostatin's ability to decrease VEGF(165)-induced paracellular permeability.

Inhibition of platelet-derived growth factor promotes pericyte loss and angiogenesis in ischemic retinopathy

We investigated whether inhibition of platelet-derived growth factor (PDGF) receptor tyrosine kinase activity would affect pericyte viability, vascular endothelial growth factor (VEGF)/vascular endothelial growth factor receptor-2 (VEGFR-2) expression and angiogenesis in a model of retinopathy of prematurity (ROP). ROP was induced in Sprague Dawley rats by exposure to 80% oxygen from postnatal (P) days 0 to 11 (with 3 hours/day in room air), and then room air from P12-18 (angiogenesis period). Shams were neonatal rats in room air from P0-18. STI571, a potent inhibitor of PDGF receptor tyrosine kinase, was administered from P12-18 at 50 or 100 mg/kg/day intraperitoneal (i.p.). Electron microscopy revealed that pericytes in the inner retina of both sham and ROP rats appeared normal; however STI571 induced a selective pericyte and vascular smooth muscle degeneration. Immunolabeling for caspase-3 and a-smooth muscle cell actin in consecutive paraffin sections of retinas confirmed that these degenerating cells were apoptotic pericytes. In all groups, VEGF and VEGFR-2 gene expression was located in ganglion cells, the inner nuclear layer, and retinal pigment epithelium. ROP was associated with an increase in both VEGF and VEGFR-2 gene expression and blood vessel profiles in the inner retina compared to sham rats. STI571 at both doses increased VEGF and VEGFR-2 mRNA and exacerbated angiogenesis in ROP rats, and in sham rats at 100 mg/kg/day. In conclusion, PDGF is required for pericyte viability and the subsequent prevention of VEGF/VEGFR-2 overexpression and angiogenesis in ROP.

Stroma-free hemoglobin increases blood pressure and GFR in the hypotensive rat: role of nitric oxide.

The short-term systemic and renal hemodynamic effects of two stroma-free hemoglobin (SFH) solutions, one unmodified and the other modified by cross-linking, were examined in anesthetized rats after hemorrhagic hypotension. Both forms of SFH increased mean arterial pressure (MAP) and glomerular filtration rate (GFR) to baseline (prehemorrhage) values. The increase in MAP induced by unmodified SFH was greater than the increase in MAP caused by an albumin solution isoncotic to the unmodified SFH solution. Similarly, the increase in MAP caused by the modified SFH was also substantially greater than that induced by an albumin solution of comparable oncotic pressure to the modified SFH solution. Both unmodified and modified SFH increased GFR. As with MAP, the increase in GFR induced by both SFH solutions was greater than that associated with the oncotically matched albumin solutions. In separate experiments, the effects of nitric oxide (NO) inhibition with N omega-nitro-L-arginine methyl ester (L-NAME) on MAP after hemorrhagic hypotension and subsequent infusion of unmodified SFH or albumin were also examined. In the albumin-infused rats, L-NAME increased MAP. In marked contrast, NO inhibition with L-NAME had no further effect on MAP when infused after SFH. We conclude that both unmodified and modified SFH solutions acutely improve MAP and GFR by the combined effects of intravascular volume expansion resulting from the colloid effect of the protein and by inactivation of NO.