Neonatal brain injury and systemic inflammation: modulation by activated protein C ex vivo.

Infection and inflammation can be antecedents of neonatal encephalopathy (NE) and increase the risk of neurological sequelae. Activated protein C (APC) has anti-coagulant and anti-inflammatory effects and provides neuroprotection in brain and spinal cord injury. We examined neutrophil and monocyte responses to lipopolysaccharide (LPS) in infants with NE compared with healthy adult and neonatal controls, and also studied the effect of APC. Whole blood was incubated with LPS and APC and Toll-like receptor (TLR)-4 (LPS recognition), CD11b expression (activation) and intracellular reactive oxygen intermediate (ROI; function) release from neutrophils and monocytes was examined by flow cytometry serially from days 1 to 7. We found a significant increase in neutrophil ROI in infants with NE on day 3 following LPS compared to neonatal controls and this augmented response was reduced significantly by APC. Neutrophil and monocyte CD11b expression was increased significantly on day 1 in infants with NE compared to neonatal controls. LPS-induced neutrophil TLR-4 expression was increased significantly in infants with NE on days 3 and 7 and was reduced by APC. LPS-induced monocyte TLR-4 was increased significantly in infants with NE on day 7. Neutrophil and monocyte activation and production of ROIs may mediate tissue damage in infants with NE. APC modified LPS responses in infants with NE. APC may reduce the inflammatory responses in NE and may ameliorate multi-organ dysfunction. Further study of the immunomodulatory effects of protein C may be warranted using mutant forms with decreased bleeding potential.

Prostate cancer risk assessment tools in an unscreened population.

OBJECTIVE: To compare the prostate cancer prevention trial risk calculator (PCPT-RC) and European randomized study of screening for prostate cancer risk calculator (ERSPC-RC) in a unique unscreened population from the West of Ireland. PATIENTS AND METHODS: Data was prospectively recorded for all 556 consecutive men who underwent prostate biopsy at our institution as part of the Rapid Access Prostate Assessment Clinic program in Ireland. The estimated probabilities of detecting prostate cancer and high-grade disease were calculated using the PCPT and ERSPC risk calculators. For each calculator the discriminative ability, calibration and clinical utility was assessed. RESULTS: Prostate cancer was detected in 49% and high-grade prostate cancer in 34% of men. Receiver operating characteristic curve analysis demonstrated that the PCPT-RCs outperformed the ERSPC-RCs for the prediction of prostate cancer areas underneath the ROC curve (AUC 0.628 vs. 0.588, p = 0.0034) and for the prediction of high-grade prostate cancer (AUC 0.792 vs. 0.690, p = 0.0029). Both risk calculators generally over-predicted the risk of prostate cancer and high-grade disease across a wide range of predicted probabilities. Decision curve analysis suggested greater net benefit using the PCPT-RCs in this population. CONCLUSIONS: Multivariable nomograms can further aid patient counselling for early prostate cancer detection. In unscreened men from Western Ireland, the PCPT-RCs provided better discrimination for overall prostate cancer and high-grade disease compared to the ERSPC-RC. However, both tools overpredicted the risk of cancer detection on biopsy, and it is possible that a different set of predictive variables may be more useful in this population.

Bacterial lipopolysaccharide promotes profibrotic activation of intestinal fibroblasts.

BACKGROUND: Fibroblasts play a critical role in intestinal wound healing. Lipopolysaccharide (LPS) is a cell wall component of commensal gut bacteria. The effects of LPS on intestinal fibroblast activation were characterized. METHODS: Expression of the LPS receptor, toll-like receptor (TLR) 4, was assessed in cultured primary human intestinal fibroblasts using flow cytometry and confocal microscopy. Fibroblasts were treated with LPS and/or transforming growth factor (TGF) beta1. Nuclear factor kappaB (NFkappaB) pathway activation was assessed by inhibitory kappaBalpha (IkappaBalpha) degradation and NFkappaB promoter activity. Fibroblast contractility was measured using a fibroblast-populated collagen lattice. Smad-7, a negative regulator of TGF-beta1 signalling, and connective tissue growth factor (CTGF) expression were assessed using reverse transcriptase-polymerase chain reaction and western blot. The NFkappaB pathway was inhibited by IkappaBalpha transfection. RESULTS: TLR-4 was present on the surface of intestinal fibroblasts. LPS treatment of fibroblasts induced IkappaBalpha degradation, enhanced NFkappaB promoter activity and increased collagen contraction. Pretreatment with LPS (before TGF-beta1) significantly increased CTGF production relative to treatment with TGF-beta1 alone. LPS reduced whereas TGF-beta1 increased smad-7 expression. Transfection with an IkappaBalpha plasmid enhanced basal smad-7 expression. CONCLUSION: Intestinal fibroblasts express TLR-4 and respond to LPS by activating NFkappaB and inducing collagen contraction. LPS acts in concert with TGF-beta1 to induce CTGF. LPS reduces the expression of the TGF-beta1 inhibitor, smad-7.

Endoglin negatively regulates transforming growth factor beta1-induced profibrotic responses in intestinal fibroblasts.

BACKGROUND: Fibroblasts isolated from strictures in Crohn's disease (CD) exhibit reduced responsiveness to stimulation with transforming growth factor (TGF) beta1. TGF-beta1, acting through the smad pathway, is critical to fibroblast-mediated intestinal fibrosis. The membrane glycoprotein, endoglin, is a negative regulator of TGF-beta1. METHODS: Intestinal fibroblasts were cultured from seromuscular biopsies of patients undergoing intestinal resection for CD strictures or from control patients. Endoglin expression was assessed using confocal microscopy, flow cytometry and western blot. The effect of small interfering (si) RNA-mediated knockdown and plasmid-mediated overexpression of endoglin on fibroblast responsiveness to TGF-beta1 was assessed by examining smad phosphorylation, smad binding element (SBE) promoter activity, connective tissue growth factor (CTGF) expression and ability to contract collagen. RESULTS: Crohn's stricture fibroblasts expressed increased constitutive cell-surface and whole-cell endoglin relative to control cells. Endoglin co-localized with filamentous actin. Fibroblasts treated with siRNA directed against endoglin exhibited enhanced TGF-beta1-mediated smad-3 phosphorylation, and collagen contraction. Cells transfected with an endoglin plasmid did not respond to TGF-beta1 by exhibiting SBE promoter activity or producing CTGF. CONCLUSION: Fibroblasts from strictures in CD express increased constitutive endoglin. Endoglin is a negative regulator of TGF-beta1 signalling in the intestinal fibroblast, modulating smad-3 phosphorylation, SBE promoter activity, CTGF production and collagen contraction.

Statins alter neutrophil migration by modulating cellular Rho activity--a potential mechanism for statins-mediated pleotropic effects?

The ability of neutrophils to sense and migrate toward damaged tissue is a vital component of the innate immune response. Paradoxically, this same migration serves as the hallmark of a number of inflammatory conditions, including ischemic reperfusion injury, atherosclerosis, arthritis, and Crohn's disease. More recent evidence suggests that neutrophil infiltration into the cardiac allograft following transplantation is a contributing factor in allograft rejection. We have demonstrated previously a positive correlation between the degree of neutrophil migration and subsequent rejection grades in a cohort of cardiac transplant recipients. Intracellular signaling pathways that are intimately involved in neutrophil migration thus offer potential targets of manipulation in the treatment of such conditions. 3-hydroxy-3-methylyglutaryl-coenzyme A reductase inhibitors or statins are emerging as potential anti-inflammatory agents and have a proven survival benefit in the transplant population. Yet, little is known about their ability to modulate neutrophil function and their subsequent mechanism of action. We demonstrate here that pravastatin, simvastatin, and atorvastatin significantly reduce neutrophil transendothelial migration toward the chemoattractant fMLP. This effect is independent of any change in neutrophil adhesion or adhesion molecule expression but is related to the ability of statins to reduce fMLP-induced Rho activity in neutrophils. This was confirmed by the ability of the Rho precursor geranylgeranyl pyrophosphate to rescue the statin-mediated reduction in neutrophil transendothelial migration. Understanding the mechanisms of action of statins in the neutrophil allows for their use in targeting excessive migration in inappropriate inflammatory conditions.

External validation of the 2007 and 2001 Partin tables in Irish prostate cancer patients.

INTRODUCTION: External validation of predictive prostate cancer nomograms is of critical importance within distinct geographical locations, prior to their institution into routine clinical practice. We performed external validation of the 2007 and 2001 Partin tables in a cohort of Irish prostate cancer patients. PATIENTS AND METHODS: Men enrolled in the Irish Prostate Cancer Research Consortium (n = 175) and who had undergone radical prostatectomy between 2004 and 2008 were used to externally validate the 2007 and 2001 Partin tables. A comparative analysis of the clinical and pathological parameters of the Irish and Partin patient cohorts was performed. The reported receiver operating characteristic (ROC) curve derived area under the curve (AUC) values were used to assess for variations in predictive accuracy. Statistical analyses were calculated with R software. RESULTS: AUC values assigned to the differentiation of extra-prostatic extension and seminal vesicle invasion using the 2007 tables are 22 and 3%, respectively. The 2007 Partin tables showed superior accuracy for all parameters, excluding seminal vesicle invasion. CONCLUSION: Cumulatively the Partin tables showed poor discriminate ability for prediction of post-radical prostatectomy pathological outcomes in Irish men, necessitating caution in their clinical utilisation.

Simvastatin impairs smad-3 phosphorylation and modulates transforming growth factor beta1-mediated activation of intestinal fibroblasts.

BACKGROUND: Transforming growth factor (TGF) beta1, acting through the smad pathway, is critical to fibroblast-mediated intestinal fibrosis. Simvastatin exhibits antifibrotic properties. This study assessed the effects of simvastatin on TGF-beta1-mediated intestinal fibroblast activation. METHODS: Human intestinal fibroblasts were activated with TGF-beta1 with or without simvastatin or the cholesterol pathway intermediates farnesyl pyrophosphate (FPP) and geranylgeranyl pyrophosphate (GGPP). Collagen-Ialpha2 expression was assessed by reverse transcriptase-polymerase chain reaction. Connective tissue growth factor (CTGF) and smad phosphorylation were evaluated by western blot, and plasminogen activator inhibitor (PAI) 1 activity by enzyme-linked immunosorbent assay. Fibroblast filamentous (F)-actin accumulation was assessed by confocal microscopy and contraction by a fibroblast-populated collagen lattice (FPCL) model. RESULTS: TGF-beta1 treatment of fibroblasts induced smad-2/3 phosphorylation, CTGF and collagen-Ialpha2 production, F-actin bundling, FPCL contraction and PAI-1 activation. Pretreatment with simvastatin inhibited the induction of CTGF and collagen-Ialpha2, PAI-1 activation, F-actin bundling and FPCL contraction. The inhibitory effect of simvastatin on PAI-1 activation was reversed by GGPP and FPP. Simvastatin pretreatment inhibited TGF-beta1-mediated phosphorylation of smad-3. CONCLUSION: Simvastatin abrogates TGF-beta1-mediated intestinal fibroblast activation by inhibition of smad-3 phosphorylation. These findings offer a mechanism for the antifibrotic effects of simvastatin and a therapeutic entry point in the treatment of intestinal fibrosis.

Maternal and neonatal lipopolysaccharide and Fas responses are altered by antenatal risk factors for sepsis.

The diagnosis of neonatal sepsis is difficult, resulting in unnecessary treatment to minimize morbidity and mortality. We hypothesized that exposure to antenatal risk factors for sepsis alters the perinatal neutrophil phenotype. The study setting was a tertiary referral university-affiliated maternity and neonatal hospital. Neutrophils from adults, normal neonates, neonates with antenatal sepsis risk factors and their respective maternal samples were incubated alone, with agonistic Fas antibody or with lipopolysaccharide (LPS). Surface receptor CD11b expression and the percentage apoptosis (persistent inflammatory response) were assessed using flow cytometry. Both mothers and asymptomatic neonates exposed to maternal sepsis risk factors had increased spontaneous neutrophil apoptosis compared to their respective controls. Infants with sepsis were LPS and Fas hyporesponsive. Maternal neutrophils had a delay in apoptosis in all groups with enhanced LPS and Fas responses associated with neonatal sepsis. CD11b expression was not altered significantly between groups. Maternal neutrophil function is altered in neonatal sepsis and may have a diagnostic role. Neonatal sepsis was associated with LPS hyporesponsiveness, potentially increasing susceptibility to infection.

Differential white cell count relationships with human cardiac allograft rejection.

The focus of research in allograft rejection has targeted the lymphocyte, with little attention given to the neutrophil. Recent data indicate that a perioperative neutrophil influx into the cardiac allograft influences early rejection. Factors that influence neutrophil transendothelial migration might offer predictive markers of rejection. We explored the relationship between the number of circulating neutrophils in heart transplant recipients and the development of rejection. Differential white cell counts were obtained prior to transplantation and concurrently with subsequent endomyocardial rejection surveillance biopsies for 53 heart transplant recipients undergoing 410 biopsies. Preoperative differential white cell counts had no relationship with rejection. In the first 3 months after transplantation, no relationship was found between contemporary differential white cell counts and rejection. However, more than 3 months following surgery, rejection grade positively correlated on univariate analysis with neutrophil counts and the usage of cyclosporine, prednisolone, and mycophenolate. There was no relationship with eosinophils or lymphocytes. Multivariate analysis demonstrated a persistent relationship among rejection severity, neutrophil count, and prednisolone usage. A significant positive association of higher steroid usage with higher rejection grades must reflect efforts to treat patients with rejection. The significant association of higher neutrophil counts with higher rejection severity might suggest a pathological contribution to rejection. However, given the neutrophilia response to acute steroid administration, we must conclude that the neutrophil association was related to steroid administration. The absence of a relationship between white cell counts and rejection suggests that functional rather than antiproliferative strategies may offer the greatest therapeutic potential.

Transforming growth factor-beta (TGF-beta) in acute injuries of the spinal cord.

Injuries to the spinal cord may be associated with increased healing of fractures. This can be of benefit, but excessive bone growth can also cause considerable adverse effects. We evaluated two groups of patients with fractures of the spinal column, those with neurological compromise (n=10) and those without (n=15), and also a control group with an isolated fracture of a long bone (n=12). The level of transforming growth factor-beta (TGF-beta), was measured at five time points after injury (days 1, 5, 10, 42 and 84). The peak level of 142.79 ng/ml was found at day 84 in the neurology group (p<0.001 vs other time points). The other groups peaked at day 42 and had a decrease at day 84 after injury (p

Persistent systemic monocyte and neutrophil activation in neonatal encephalopathy.

AIM: Circulating immune cell activation is associated with worse outcome in adult and animal models of brain injury. Our aim was to profile the systemic inflammatory response over the first week of life in infants at risk of neonatal encephalopathy and correlate early neutrophil and monocyte endotoxin and activation responses with outcome. METHODS: Prospective observational study in a tertiary referral university hospital including 22 infants requiring resuscitation at birth who had serial (five time points) neutrophil and monocyte CD11b (marker of cell adhesion) (intracellular Reactive oxygen intermediates) ROI (cell activation), and Toll-like receptor (endotoxin recognition) before and after endotoxin stimulation ex vivo compared to neonatal controls. RESULTS: All neonates requiring resuscitation at delivery (n = 122 samples) had higher neutrophil and monocyte CD11b and TLR-4 expressions compared with adults and neonatal controls. Neonates with abnormal neuroimaging and/or severe neonatal encephalopathy had increased CD11b, ROI and TLR-4. Increased PMN TLR-4 expression was associated with increased mortality in infants with neonatal encephalopathy (NE). CONCLUSION: Innate immune dysregulation in the first week of life is associated with severity of outcome in neonatal brain injury in this cohort and may be amenable to immunomodulation.

Persistent systemic monocyte and neutrophil activation in neonatal encephalopathy.

AIM: Circulating immune cell activation is associated with worse outcome in adult and animal models of brain injury. Our aim was to profile the systemic inflammatory response over the first week of life in infants at risk of neonatal encephalopathy (NE) and correlate early neutrophil and monocyte endotoxin and activation responses with outcome. METHODS: Prospective observational study in a tertiary referral university hospital including 22 infants requiring resuscitation at birth who had serial (five time points) neutrophil and monocyte CD11b (marker of cell adhesion), intracellular reactive oxygen intermediates (ROI; cell activation) and Toll-like receptor (TLR; endotoxin recognition) before and after endotoxin stimulation ex vivo compared to neonatal controls. RESULTS: All neonates requiring resuscitation at delivery (n = 122 samples) had higher neutrophil and monocyte CD11b and TLR-4 expression compared with adults and neonatal controls. Neonates with abnormal neuroimaging and/or severe NE had increased CD11b, ROI and TLR-4. Increased polymorphonuclear leukocytes TLR-4 expression was associated with increased mortality in infants with NE. CONCLUSION: Innate immune dysregulation in the first week of life is associated with severity of outcome in neonatal brain injury in this cohort and may be amenable to immunomodulation.

The loss of IAP expression during HL-60 cell differentiation is caspase-independent.

Human promyelocytic leukaemia cells (HL-60) differentiate into neutrophil-like cells that die spontaneously by apoptosis when treated with retinoic acid (RA). Inhibitors of apoptosis proteins (IAP) bind to and inhibit caspases 3, 7, and 9 activity and the induction of apoptosis. In this study, we demonstrate that undifferentiated HL-60 cells express IAP. During their differentiation, IAP expression is decreased at the mRNA and protein levels. In addition, we show that there is a corresponding increase in the expression and functional activity of active caspases 3 and 9. This activity was associated with the cleavage of XIAP, NAIP, and cIAP-2. Most importantly, we demonstrate that blocking caspase activity does not alter the decrease in IAP protein expression during differentiation but prevents caspase activation, IAP cleavage, and the induction of apoptosis. This result shows that the loss of IAP expression is independent of the induction of apoptosis and is solely related to the differentiation process. However, IAP cleavage is caspase-dependent. Terminal differentiation results in an altered apoptotic phenotype that is associated with the induction of HL-60 cell apoptosis.

Predicting prostate cancer: analysing the clinical efficacy of prostate cancer risk calculators in a referral population.

BACKGROUND: The decision to proceed to biopsy for the diagnosis of prostate cancer in clinical practice is a difficult one. Prostate cancer risk calculators allow for a systematic approach to the use of patient information to predict a patient's likelihood of prostate cancer. AIMS: In this paper, we validate the two leading prostate cancer risk calculators, the prostate cancer prevention trial (PCPT) and the European Randomized Study of Screening for Prostate Cancer (ERSPC) in an Irish population. METHODS: Data were collected for 337 men referred to one tertiary referral center in Ireland. Calibration analysis, ROC analysis and decision curve analysis were undertaken to ascertain the performance of the PCPT and the ERSPC risk calculators in this cohort. RESULTS: Of 337 consecutive biopsies, cancer was subsequently diagnosed in 146 men (43 %), 98 (67 %) of which were high grade. The AUC for the PCPT and ERSPC risk calculators were 0.68 and 0.66, respectively for the prediction of prostate cancer. Each calculator was sufficiently calibrated in this cohort. Decision curve analysis demonstrated a net benefit via the use of the PCPT and ERSPC risk calculators in the diagnosis of prostate cancer. CONCLUSIONS: The PCPT and ERSPC risk calculators achieve a statistically significant prediction of prostate cancer in this Irish population. This study provides external validation for these calculators, and therefore these tools can be used to aid in clinical decision making.

Redox regulation of neutrophil apoptosis.

The persistence of a neutrophil-mediated inflammatory response is due in part to a delay in their spontaneous rates of apoptosis or cell death. Regulating apoptosis has important implications for the resolution of inflammatory disorders, such as the systemic inflammatory response syndrome or acute respiratory distress syndrome. Neutrophils through their primary function of killing bacteria generate large concentrations of reactive oxygen intermediates and have alterations in the levels of antioxidants. Reactive oxygen intermediates and antioxidants are important regulators of the apoptotic caspases, but the mechanisms involved are still under debate and investigation. This review addresses the role of the cellular redox status of neutrophils on the apoptotic cascade leading to cell death.

Future opportunities for the diagnosis and treatment of prostate cancer.

Despite recent advances, current diagnostic tests and treatment of prostate cancer have limitations. In the last few years, numerous biomolecules have been investigated with the aim of improving diagnosis, including kallikrein-like proteases, growth factors and neuroendocrine markers. Analysis of susceptibility genes has also been a focus of attention. Extensive research into new therapeutic approaches is also underway, including targeting angiogenesis, immune regulation and stromal-epithelial interactions. Gene therapy, gene chip technology and proteomics have emerged as promising innovations. The host of novel diagnostic markers and therapies require appropriate validation, both phenotypical and functional. A further consideration is the need to re-evaluate clinical trial design and end points to facilitate progression of promising targets through the clinical trial process. Overall, the outlook for the treatment of prostate cancer looks promising, with any advances likely to require both a multimodal and multidisciplinary approach.

Intervertebral discs which cause low back pain secrete high levels of proinflammatory mediators.

Herniated intervertebral disc tissue has been shown to produce a number of proinflammatory mediators and cytokines, but there have been no similar studies using discs from patients with discogenic low back pain. We have compared the levels of production of interleukin-6 (IL-6), interleukin-8 (IL-8) and prostaglandin E2 (PGE2) in disc tissue from patients undergoing discectomy for sciatica (63) with that from patients undergoing fusion for discogenic low back pain (20) using an enzyme-linked immunoabsorbent assay. There was a statistically significant difference between levels of production of IL-6 and IL-8 in the sciatica and low back pain groups (p < 0.006 and p < 0.003, respectively). The high levels of proinflammatory mediator found in disc tissue from patients undergoing fusion suggest that production of proinflammatory mediators within the nucleus pulposus may be a major factor in the genesis of a painful lumbar disc.

Apoptosis in the prostate.

The prostate requires androgens for development and glandular maintenance, dying by the process of apoptosis following their removal. Anti-androgen therapy is targeted to induce this process but eventually fails with the emergence of an androgen independent cancer. These cells have development mechanisms to survive with out androgen impart due to the expression of anti-apoptotic factors.

Novel predictive tools for Irish radical prostatectomy pathological outcomes: development and validation.

AIMS: We developed and validated prostate cancer predictive models for Irish patients, allowing individualised predictions of radical prostatectomy pathological outcomes. METHODS: Retrospective review of the Irish Prostate Cancer Research Consortium database from 2003 to 2008 was performed. Two predictive models were formulated: a replica of the Partin tables (n = 169) and a look-up table based on PSA and biopsy Gleason Score (n = 253). Clinico-pathological parameters were compared to the Partin data set. Internal validation was performed. RESULTS: In total, 70% of patients were at clinical stage T1c. 5.8% had a PSA less than 4.1 ng/ml, whereas 25% of the Partin patients had a PSA in this range. Maximal predictive accuracy was seen for seminal vesicle invasion (area under the curve = 72%). Prediction of extra-prostatic extension and lymph node involvement was only equivalent to that of a chance phenomenon. CONCLUSIONS: Our current results do not support the introduction of the formulated predictive models into routine clinical practice.

Neutrophil immunosurveillance for heart transplant rejection: a prospective study.

Immunologic surveillance for rejection detection in human heart transplantation offers many potential advantages. To date, investigative efforts have focused primarily on the acquired immune system, particularly the lymphocyte. Little attention has been given to aspects of innate immune function. We have previously reported that perioperative neutrophil adhesion molecule expression is associated with early rejection episodes after human cardiac transplantation. Herein we have investigated the utility of neutrophil immunosurveillance in human heart transplant recipients at later time points. We recruited patients more than 3 months after transplantation. Neutrophil assessment was performed simultaneously with an endomyocardial biopsy that showed rejection. No significant relationship was seen between neutrophil maturity (P = .622; n = 34), adhesion marker expression (P = .567; n = 34), respiratory burst (P = .604; n = 34), or apoptosis rates (P = .662; n = 34) and contemporary rejection status at >3 months after transplantation. However, interesting relationships were noted between neutrophil adhesion markers at this late stage and historical rejection status. Higher levels of the adhesion protein CD11b observed at this late stage were significantly associated with a history of higher rejection grades in the first postoperative biopsy (Spearman rank coefficient 0.359; R = 0.304; P = .005; n = 62). Other aspects of neutrophil function and persistence were not significantly associated with rejection history. This finding, combined with the previously reported findings, supports a role for an individual phenotype in neutrophil function in early rejection episodes after transplantation.