Investigating biomechanical determinants of endothelial permeability in a hollow fibre bioreactor

The effect of haemodynamic stresses on endothelial permeability to macromolecules is important to normal physiology and in the pathogenesis of atherosclerosis. I developed and applied novel methods to evaluate effects on such transport of acute or chronic exposure to flow along and across cultured endothelium. Porcine aortic endothelial cells were isolated and cultured at passage 1-3 within the porous capillaries of a FiberCell bioreactor. At confluence they were exposed to acute (4 h) or chronic (3-10 day) steady or pulsatile luminal flow (mean shear 3.75 dyne/cm2), with or without transendothelial flow (4 x 10-7 cm/s). Permeability to rhodamine-labelled albumin was assessed by fluorimetry. Confluence of monolayers was confirmed by confocal and scanning electron microscopy and by demonstrating established effects of vasoactive agents on permeability: 10 U/ml thrombin increased permeability, as did 500 μM Nω-nitro-Larginine methyl ester, compared to controls. Permeability was increased by acute pulsatile shear and decreased by chronic pulsatile shear compared to static controls. A decrease in PECAM-1 expression under chronic pulsatile flow was demonstrated by flow cytometry. Steady flow gave higher permeability than pulsatile flow. The introduction of transendothelial flow increased apparent permeability more than could be explained by the addition of the convective transport itself. Preliminary studies suggested that albumin transport may partially be an active process and demonstrated the potential for engineered fibre walls that would allow effects of cyclic strain to be investigated. In conclusion, the hollow fibre bioreactor allowed endothelial permeability to be measured with or without exposure to luminal flow and transendothelial flow over 30 days, permitting the investigation of effects of mechanical stresses. Effects of shear stress varied with duration, pulsatility and direction relative to the endothelial surface.Open Acces

The pathological physiology of helminth infestation. lll. Trichostrongylus colubriformis

Trials are described in which the reactions of 11 sheep infested with T. colubriformis and 11 uninfected controls were studied in detail. The main findings in the acute disease were anorexia, retention of ingesta in the rumen and abomasum, diarrhoea, a severe hypo-albuminaemia and death 16 to 17 days after infestation. In the chronic disease there was a progressive decrease in feed intake and loss of body weight. Plasma albumin concentration decreased with a rise in plasma gamma globulin concentration later in the disease. A drop in packed red cell volume, haemoglobin concentration, red cell count, total volume of circulating erythrocytes and plasma inorganic phosphate was noted. There was a decrease in protein, phosphate and possibly selenium uptake leading to emaciation, muscular and myocardial atrophy and degeneration and eventually death.The journals have been scanned in colour with a HP 5590 scanner; 600 dpi. Adobe Acrobat v.11 was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

Interferon Gamma, but not Calcitriol Improves the Osteopetrotic Phenotypes in ADO2 Mice

ADO2 is a heritable osteosclerotic disorder that usually results from heterozygous missense dominant negative mutations in the chloride channel 7 gene (CLCN7). ADO2 is characterized by a wide range of features and severity, including multiple fractures, impaired vision due to secondary bony overgrowth and/or the lack of the optical canal enlargement with growth, and osteonecrosis/osteomyelitis. The disease is presently incurable, although anecdotal evidence suggests that calcitriol and interferon gamma-1b (IFN-G) may have some beneficial effects. To identify the role of these drugs for the treatment of ADO2, we utilized a knock-in (G213R mutation in Clcn7) ADO2 mouse model that resembles the human disease. Six-week-old ADO2 heterozygous mice were administered vehicle (PBS) or calcitriol or IFN-G 5 times per week for 8 weeks. We determined bone phenotypes using DXA and μCT, and analyzed serum biochemistry and bone resorption markers. ADO2 mice treated with all doses of IFN-G significantly (p<0.05) attenuated the increase of whole body aBMD and distal femur BV/TV gain in both male and female compared to the vehicle group. In contrast, mice treated with low and medium doses of calcitriol showed a trend of higher aBMD and BV/TV whereas high dose calcitriol significantly (p<0.05) increased bone mass compared to the vehicle group. The calcium and phosphorus levels did not differ between vehicle and IFN-G or calcitriol treated mice; however, we detected significantly (p<0.05) elevated levels of CTX/TRAP5b ratio in IFN-G treated mice. Our findings indicate that while IFN-G at all doses substantially improved the osteopetrotic phenotypes in ADO2 heterozygous mice, calcitriol treatment at any dose did not improve the phenotype and at high dose further increased bone mass. Thus, use of high dose calcitriol therapy in ADO2 patients merits serious reconsideration. Importantly, our data support the prospect of a clinical trial of IFN-G in ADO2 patients

Development and psychometric evaluation of an observational coding system measuring person-centred care in spouses of people with dementia

YesBackground: The notion of person-centered care has been important in investigating relationships between people with dementia and paid carers, and measures are available to assess this. It has been suggested that person-centered care may be a useful construct to apply to understand family-care relationships. However, no measures of person-centered care in this context exist. The study aimed to develop an observational measure of person-centered care for this purpose. Method: First, a coding system incorporating a range of behaviors that could be considered person-centered or non-person-centered was constructed. Examples included a code relating to whether the person with dementia was involved in planning a task, and a code relating to how the spouse responded to confusion/distress. Second, 11 couples, where one partner had a dementia, were recruited and videotaped cooperating on an everyday task. The system was applied to the care-giving spouse's behaviors, labeling examples of behavior as person-centered or non-person-centered. The final step involved assessing the inter-rater reliability of the system. Results: The system captured nine categories of behavior, which were each divided into person-centered and non-person-centered types. The system had good reliability (Cohen's κ coefficients were: 0.65 for category and whether behaviors needed to be placed in a category; 0.81 for category excluding the decision about whether behaviors needed to be placed in a category; and 0.79 in relation to whether behaviors were person-centered or non-person-centered.) Conclusions: Although the small sample size limits the implications of the results, the system is a promising quantitative measure of spousal person-centered care

MicroRNA expression signature in human abdominal aortic aneurysms

Background: Abdominal aortic aneurysm (AAA) is a dilatation of the aorta affecting most frequently elderly men. Histologically AAAs are characterized by inflammation, vascular smooth muscle cell apoptosis, and extracellular matrix degradation. The mechanisms of AAA formation, progression, and rupture are currently poorly understood. A previous mRNA expression study revealed a large number of differentially expressed genes between AAA and non-aneurysmal control aortas. MicroRNAs (miRNAs), small non-coding RNAs that are post-transcriptional regulators of gene expression, could provide a mechanism for the differential expression of genes in AAA. Methods: To determine differences in miRNA levels between AAA (n = 5) and control (n = 5) infrarenal aortic tissues, a microarray study was carried out. Results were adjusted using Benjamini-Hochberg correction (adjusted p\u3c 0.05). Real-time quantitative RT-PCR (qRT-PCR) assays with an independent set of 36 AAA and seven control tissues were used for validation. Potential gene targets were retrieved from miRNA target prediction databases Pictar, TargetScan, and MiRTarget2. Networks from the target gene set were generated and examined using the network analysis programs, CytoScape® and Ingenuity Pathway Core Analysis®. Results: A microarray study identified eight miRNAs with significantly different expression levels between AAA and controls (adjusted p \u3c 0.05). Real-time qRT-PCR assays validated the findings for five of the eight miRNAs. A total of 222 predicted miRNA target genes known to be differentially expressed in AAA based on a prior mRNA microarray study were identified. Bioinformatic analyses revealed that several target genes are involved in apoptosis and activation of T cells. Conclusions: Our genome-wide approach revealed several differentially expressed miRNAs in human AAA tissue suggesting that miRNAs play a role in AAA pathogenesis. Keywords: Apoptosis, Microarray analysis, Vascular biology, miRNA-mRNA analysis, Network analysi

Altered Expression of ACOX2 In Non-Small Cell Lung Cancer

Peroxisomes are organelles that play essential roles in many metabolic processes, but also play roles in innate immunity, signal transduction, aging and cancer. One of the main functions of peroxisomes is the processing of very-long chain fatty acids into metabolites that can be directed to the mitochondria. One key family of enzymes in this process are the peroxisomal acyl-CoA oxidases (ACOX1, ACOX2 and ACOX3), the expression of which has been shown to be dysregulated in some cancers. Very little is however known about the expression of this family of oxidases in non-small cell lung cancer (NSCLC). ACOX2 has however been suggested to be elevated at the mRNA level in over 10% of NSCLC, and in the present study using both standard and bioinformatics approaches we show that expression of ACOX2 is significantly altered in NSCLC. ACOX2 mRNA expression is linked to a number of mutated genes, and associations between ACOX2 expression and tumour mutational burden and immune cell infiltration were explored. Links between ACOX2 expression and candidate therapies for oncogenic driver mutations such as KRAS were also identified. Furthermore, levels of acyl-CoA oxidases and other associated peroxisomal genes were explored to identify further links between the peroxisomal pathway and NSCLC. The results of this biomarker driven study suggest that ACOX2 may have potential clinical utility in the diagnosis, prognosis and stratification of patients into various therapeutically targetable options