Absence of renal hypoxia in the subacute phase of severe renal ischemia reperfusion injury

 This is the author accepted manuscript. The final version is available from American Physiological Society via the DOI in this recordTissue hypoxia has been proposed as an important event in renal ischemia reperfusion injury (IRI) particularly during the period of ischemia and in the immediate hours following reperfusion. However, little is known about renal oxygenation during the subacute phase of IRI. We employed four different methods to assess the temporal and spatial changes in tissue oxygenation during the subacute phase (24 h and 5 days after reperfusion) of a severe form of renal IRI in rats. We hypothesized that the kidney is hypoxic 24 h and 5 days after an hour of bilateral renal ischemia, driven by a disturbed balance between renal oxygen delivery (DO2) and oxygen consumption (VO2). Renal DO2 was not significantly reduced in the subacute phase of IRI. In contrast, renal VO2 was 55% less 24 h, and 49% less 5 days after reperfusion than after sham-ischemia. Inner medullary tissue PO2, measured by radiotelemetry was 25 {plus minus} 12% greater 24 h after ischemia than after sham-ischemia. By 5 days after reperfusion, tissue PO2 was similar to that in rats subjected to sham-ischemia. Tissue PO2 measured by Clark electrode was consistently greater 24 h, but not 5 days, after ischemia than after sham-ischemia. Cellular hypoxia, assessed by pimonidazole adduct immunohistochemistry, was largely absent at both time-points and tissue levels of hypoxia inducible factors were downregulated following renal ischemia. Thus, in this model of severe IRI, tissue hypoxia does not appear to be an obligatory event during the subacute phase, likely due to the markedly reduced oxygen consumption.British Heart FoundationBritish Heart FoundationNational Health and Medical Research Council of AustraliaEuropean Union, Seventh Framework Programm

Protocol for the Foot in Juvenile Idiopathic Arthritis trial (FiJIA): a randomised controlled trial of an integrated foot care programme for foot problems in JIA

<b>Background</b>: Foot and ankle problems are a common but relatively neglected manifestation of juvenile idiopathic arthritis. Studies of medical and non-medical interventions have shown that clinical outcome measures can be improved. However existing data has been drawn from small non-randomised clinical studies of single interventions that appear to under-represent the adult population suffering from juvenile idiopathic arthritis. To date, no evidence of combined therapies or integrated care for juvenile idiopathic arthritis patients with foot and ankle problems exists. <b>Methods/design</b>: An exploratory phase II non-pharmacological randomised controlled trial where patients including young children, adolescents and adults with juvenile idiopathic arthritis and associated foot/ankle problems will be randomised to receive integrated podiatric care via a new foot care programme, or to receive standard podiatry care. Sixty patients (30 in each arm) including children, adolescents and adults diagnosed with juvenile idiopathic arthritis who satisfy the inclusion and exclusion criteria will be recruited from 2 outpatient centres of paediatric and adult rheumatology respectively. Participants will be randomised by process of minimisation using the Minim software package. The primary outcome measure is the foot related impairment measured by the Juvenile Arthritis Disability Index questionnaire's impairment domain at 6 and 12 months, with secondary outcomes including disease activity score, foot deformity score, active/limited foot joint counts, spatio-temporal and plantar-pressure gait parameters, health related quality of life and semi-quantitative ultrasonography score for inflammatory foot lesions. The new foot care programme will comprise rapid assessment and investigation, targeted treatment, with detailed outcome assessment and follow-up at minimum intervals of 3 months. Data will be collected at baseline, 6 months and 12 months from baseline. Intention to treat data analysis will be conducted. A full health economic evaluation will be conducted alongside the trial and will evaluate the cost effectiveness of the intervention. This will consider the cost per improvement in Juvenile Arthritis Disability Index, and cost per quality adjusted life year gained. In addition, a discrete choice experiment will elicit willingness to pay values and a cost benefit analysis will also be undertaken

Prediction of Length of Hospital Stay in Preterm Infants - A Case-Based Reasoning View

The length of stay of preterm infants in a neonatology service has become an issue of a growing concern, namely considering, on the one hand, the mothers and infants health conditions and, on the other hand, the scarce healthcare facilities own resources. Thus, a pro-active strategy for problem solving has to be put in place, either to improve the quality-of-service provided or to reduce the inherent financial costs. Therefore, this work will focus on the development of a diagnosis decision support system in terms of a formal agenda built on a Logic Programming approach to knowledge representation and reasoning, complemented with a case-based problem solving methodology to computing, that caters for the handling of incomplete, unknown, or even contradictory in-formation. The proposed model has been quite accurate in predicting the length of stay (overall accuracy of 84.9%) and by reducing the computational time with values around 21.3%

Ser649 and Ser650 Are the Major Determinants of Protein Kinase A-Mediated Activation of Human Hormone-Sensitive Lipase against Lipid Substrates

BACKGROUND: Hormone-sensitive lipase (HSL) is a key enzyme in the mobilization of fatty acids from stored triacylglycerols. Its activity is regulated by reversible protein phosphorylation. In rat HSL Ser563, Ser659 and Ser660 have been shown to be phosphorylated by protein kinase A (PKA) in vitro as well as in vivo. METHODOLOGY/PRINCIPAL FINDINGS: In this study we employed site-directed mutagenesis, in vitro phosphorylation and mass spectrometry to show that in vitro phosphorylation of human HSL by PKA occurs primarily on Ser649 and Ser650 (Ser659 and Ser660 in rat HSL). The wild type enzyme and four mutants were expressed in C-terminally His-tagged form in Sf9 insect cells and purified to homogeneity. HSL variants in which Ser552 and/or Ser554 were mutated to Ala or Glu retained both lipolytic and non-lipolytic activity and were phosphorylated by PKA and activated to a similar extent as the wild type enzyme. (32)P-labeling studies revealed that the bulk of the phosphorylation was on the Ser649/Ser650 site, with only a minor phosphorylation of Ser552 and Ser554. MS/MS analysis demonstrated that the peptide containing Ser649 and Ser650 was primarily phosphorylated on Ser650. The mutant lacking all four serines had severely reduced lipolytic activity, but a lesser reduction in non-lipolytic activity, had S(0.5) values for p-nitrophenol butyrate and triolein comparable to those of wild type HSL and was not phosphorylated by PKA. PKA phosphorylation of the wild type enzyme resulted in an increase in both the maximum turnover and S(0,5) using the TO substrate. CONCLUSIONS: Our results demonstrate that PKA activates human HSL against lipid substrates in vitro primarily through phosphorylation of Ser649 and Ser650. In addition the results suggest that Ser649 and Ser650 are located in the vicinity of a lipid binding region and that PKA phosphorylation controls the accessibility of this region

Effect of root age on the biomechanics of seminal and nodal roots of barley (<i>Hordeum vulgare L.</i>) in contrasting soil environments

Acknowledgments The James Hutton Institute receives funding from the Scottish Government. The authors would also like to thank Jim McNicol from Biomathematics and Statistics Scotland for his advice on statistical analysis.Peer reviewedPostprin

Role of mitochondrial raft-like microdomains in the regulation of cell apoptosis

Lipid rafts are envisaged as lateral assemblies of specific lipids and proteins that dissociate and associate rapidly and form functional clusters in cell membranes. These structural platforms are not confined to the plasma membrane; indeed lipid microdomains are similarly formed at subcellular organelles, which include endoplasmic reticulum, Golgi and mitochondria, named raft-like microdomains. In addition, some components of raft-like microdomains are present within ER-mitochondria associated membranes. This review is focused on the role of mitochondrial raft-like microdomains in the regulation of cell apoptosis, since these microdomains may represent preferential sites where key reactions take place, regulating mitochondria hyperpolarization, fission-associated changes, megapore formation and release of apoptogenic factors. These structural platforms appear to modulate cytoplasmic pathways switching cell fate towards cell survival or death. Main insights on this issue derive from some pathological conditions in which alterations of microdomains structure or function can lead to severe alterations of cell activity and life span. In the light of the role played by raft-like microdomains to integrate apoptotic signals and in regulating mitochondrial dynamics, it is conceivable that these membrane structures may play a role in the mitochondrial alterations observed in some of the most common human neurodegenerative diseases, such as Amyotrophic lateral sclerosis, Huntington's chorea and prion-related diseases. These findings introduce an additional task for identifying new molecular target(s) of pharmacological agents in these pathologies

One single dose of etomidate negatively influences adrenocortical performance for at least 24 h in children with meningococcal sepsis

Objective: To investigate the effect of one single bolus of etomidate used for intubation on adrenal function in children with meningococcal sepsis. Design: Retrospective study conducted between 1997 and 2004. Setting: University-affiliated paediatric intensive care unit (PICU). Patients and participants: Sixty children admitted to the PICU with meningococcal sepsis, not treated with steroids. Interventions: Adrenal hormone concentrations were determined as soon as possible after PICU admission, and after 12h and 24h. To assess disease severity, PRISM score and selected laboratory parameters were determined. Measurements and main results: On admission, before blood was drawn, 23 children had been intubated with etomidate, 8 without etomidate and 29 were not intubated. Children who were intubated had significantly higher disease severity parameters than those not intubated, whereas none of these parameters significantly differed between children intubated with or without etomidate. Children who received etomidate had significantly lower cortisol, higher ACTH and higher 11-deoxycortisol levels than those who did not receive etomidate. Arterial glucose levels were significantly lower in children who were intubated with etomidate than in non-intubated children. When children were intubated with etomidate, cortisol levels were 3.2 times lower for comparable 11-deoxycortisol levels. Eight children died, seven of whom had received etomidate. Within 24h cortisol/ACTH and cortisol/11-deoxycortisol ratios increased significantly in children who received etomidate, but not in children who did not, resulting in comparable cortisol/ACTH ratios with still significantly lowered cortisol/11-deoxycortisol ratios 24h after admission. Conclusions: Our data imply that even one single bolus of etomidate negatively influences adrenal function for at least 24h. It might therefore increase risk of death

The role of sialomucin CD164 (MGC-24v or endolyn) in prostate cancer metastasis

BACKGROUND: The chemokine stromal derived factor-1 (SDF-1 or CXCL12) and its receptor CXCR4 have been demonstrated to be crucial for the homing of stem cells and prostate cancers to the marrow. While screening prostate cancers for CXCL12-responsive adhesion molecules, we identified CD164 (MGC-24) as a potential regulator of homing. CD164 is known to function as a receptor that regulates stem cell localization to the bone marrow. RESULTS: Using prostate cancer cell lines, it was demonstrated that CXCL12 induced both the expression of CD164 mRNA and protein. Functional studies demonstrated that blocking CD164 on prostate cancer cell lines reduced the ability of these cells to adhere to human bone marrow endothelial cells, and invade into extracellular matrices. Human tissue microarrays stained for CD164 demonstrated a positive correlation with prostate-specific antigen levels, while its expression was negatively correlated with the expression of androgen receptor. CONCLUSION: Our findings suggest that CD164 may participate in the localization of prostate cancer cells to the marrow and is further evidence that tumor metastasis and hematopoietic stem cell trafficking may involve similar processes