Design and Organization of the Dexamethasone, Light Anesthesia and Tight Glucose Control (DeLiT) Trial: a factorial trial evaluating the effects of corticosteroids, glucose control, and depth-of-anesthesia on perioperative inflammation and morbidity from major non-cardiac surgery

<p>Abstract</p> <p>Background</p> <p>The perioperative period is characterized by an intense inflammatory response. Perioperative inflammation promotes postoperative morbidity and increases mortality. Blunting the inflammatory response to surgical trauma might thus improve perioperative outcomes. We are studying three interventions that potentially modulate perioperative inflammation: corticosteroids, tight glucose control, and light anesthesia.</p> <p>Methods/Design</p> <p>The DeLiT Trial is a factorial randomized single-center trial of dexamethasone vs placebo, intraoperative tight vs. conventional glucose control, and light vs deep anesthesia in patients undergoing major non-cardiac surgery. Anesthetic depth will be estimated with Bispectral Index (BIS) monitoring (Aspect medical, Newton, MA). The primary outcome is a composite of major postoperative morbidity including myocardial infarction, stroke, sepsis, and 30-day mortality. C-reactive protein, a measure of the inflammatory response, will be evaluated as a secondary outcome. One-year all-cause mortality as well as post-operative delirium will be additional secondary outcomes. We will enroll up to 970 patients which will provide 90% power to detect a 40% reduction in the primary outcome, including interim analyses for efficacy and futility at 25%, 50% and 75% enrollment.</p> <p>Discussion</p> <p>The DeLiT trial started in February 2007. We expect to reach our second interim analysis point in 2010. This large randomized controlled trial will provide a reliable assessment of the effects of corticosteroids, glucose control, and depth-of-anesthesia on perioperative inflammation and morbidity from major non-cardiac surgery. The factorial design will enable us to simultaneously study the effects of the three interventions in the same population, both individually and in different combinations. Such a design is an economically efficient way to study the three interventions in one clinical trial vs three.</p> <p>Trial registration</p> <p><b>This trial is registered at </b>Clinicaltrials.gov <b>#</b>: NTC00433251</p

Effects of gemcitabine on APE/ref-1 endonuclease activity in pancreatic cancer cells, and the therapeutic potential of antisense oligonucleotides

Apurinic/apyrimidinic endonuclease (APE) is a key enzyme involved in DNA base excision repair (BER) that is often expressed at elevated levels in human cancers. Pancreatic cancer cells treated with the nucleoside analogue gemcitabine (2′, 2′-difluoro-2′deoxycytidine) showed increases in APE/redox effector factor (ref-1) protein levels (approximately two-fold for Panc-1 and six-fold for MiaPaCa-2), with corresponding increases in endonuclease activity. These results suggested that the activation of APE/ref-1 might be an adaptive response that contributes to gemcitabine resistance by facilitating BER. To test this hypothesis, we examined the effects of disrupting APE/ref-1 using antisense on gemcitabine toxicity. Antisense oligonucleotides decreased protein levels three-fold in MiaPaCa-2 and five-fold in Panc-1 in comparison to controls, associated with reduced endonuclease activity. Combination treatments with antisense oligonucleotides and gemcitabine partially suppressed the increase in APE/ref-1 activity seen in cells exposed to gemcitabine alone. While clonogenic assays showed only slight decreases in colony formation in cells treated with either antisense oligonucleotides or gemcitabine alone, the combination with APE/ref-1 antisense resulted in a 2-log enhancement of gemcitabine toxicity in Panc-1 cells. Overall these findings suggest that APE/ref-1 plays a significant role in gemcitabine resistance in some pancreatic cancer cells, and support the further investigation of novel treatments that target this protein

Afferent arteriolopathy and glomerular collapse but not segmental sclerosis induce tubular atrophy in old spontaneously hypertensive rats

In chronic renal disease, the temporal and spatial relationship between vascular, glomerular and tubular changes is still unclear. Hypertension, an important cause of chronic renal failure, leads to afferent arteriolopathy, segmental glomerulosclerosis and tubular atrophy in the juxtamedullary cortex. We investigated the pathological changes of hypertensive renal disease in aged spontaneously hypertensive rats using a large number of serial sections, where we traced and analyzed afferent arteriole, glomerulus and proximal tubule of single nephrons. Our major finding was that both afferent arteriolopathy and glomerular capillary collapse were linked to tubular atrophy. Only nephrons with glomerular collapse (n = 13) showed tubules with reduced diameter indicating atrophy [21.66 ± 2.56 μm vs. tubules in normotensive Wistar Kyoto rats (WKY) 38.56 ± 0.56 μm, p < 0.05], as well as afferent arteriolar wall hypertrophy (diameter 32.74 ± 4.72 μm vs. afferent arterioles in WKY 19.24 ± 0.98 μm, p < 0.05). Nephrons with segmental sclerosis (n = 10) did not show tubular atrophy and tubular diameters were unchanged (35.60 ± 1.43 μm). Afferent arteriolar diameter negatively correlated with glomerular capillary volume fraction (r = −0.36) and proximal tubular diameter (r = −0.46) implying reduced glomerular and tubular flow. In line with this, chronically damaged tubules showed reduced staining for the ciliary protein inversin indicating changed ciliary signalling due to reduced urinary flow. This is the first morphological study on hypertensive renal disease making correlations between vascular, glomerular and tubular components of individual nephron units. Our data suggest that afferent arteriolopathy leads to glomerular collapse and reduced urinary flow with subsequent tubular atrophy

Comparison of published orthopaedic trauma trials following registration in Clinicaltrials.gov

<p>Abstract</p> <p>Background</p> <p>After the Food and Drug Administration Modernization Act of 1997, the registration of all clinical trials became mandatory prior to publication. Our primary objective was to determine publication rates for orthopaedic trauma trials registered with ClinicalTrials.gov. We further evaluated methodological consistency between registration and publication.</p> <p>Methods</p> <p>We searched Clinical Trials.gov for all trials related to orthopaedic trauma. We excluded active trials and trials not completed by July 2009, and performed a systematic search for publications resulting from registered closed trials. Information regarding primary and secondary outcomes, intervention, study sponsors, and sample size were extracted from registrations and publications.</p> <p>Results</p> <p>Of 130 closed trials, 37 eligible trials resulted in 16 publications (43.2%). We found no significant differences in publication rates between funding sources for industry sponsored studies and nongovernment/nonindustry sponsored studies (<it>p </it>> 0.05). About half the trials (45%) did not include the NCT ID in the publication. Two (10%) publications had major changes to the primary outcome measure and ten (52.6%) to sample size.</p> <p>Conclusions</p> <p>Registration of orthopaedic trauma trials does not consistently result in publication. When trials are registered, many do not cite NCT ID in the publication. Furthermore, changes that are not reflected in the registry of the trial are frequently made to the final publication.</p

Finite element modeling and in vivo analysis of electrode configurations for selective stimulation of pudendal afferent fibers

<p>Abstract</p> <p>Background</p> <p>Intraurethral electrical stimulation (IES) of pudendal afferent nerve fibers can evoke both excitatory and inhibitory bladder reflexes in cats. These pudendovesical reflexes are a potential substrate for restoring bladder function in persons with spinal cord injury or other neurological disorders. However, the complex distribution of pudendal afferent fibers along the lower urinary tract presents a challenge when trying to determine the optimal geometry and position of IES electrodes for evoking these reflexes. This study aimed to determine the optimal intraurethral electrode configuration(s) and locations for selectively activating targeted pudendal afferents to aid future preclinical and clinical investigations.</p> <p>Methods</p> <p>A finite element model (FEM) of the male cat urethra and surrounding structures was generated to simulate IES with a variety of electrode configurations and locations. The activating functions (AFs) along pudendal afferent branches innervating the cat urethra were determined. Additionally, the thresholds for activation of pudendal afferent branches were measured in α-chloralose anesthetized cats.</p> <p>Results</p> <p>Maximum AFs evoked by intraurethral stimulation in the FEM and in vivo threshold intensities were dependent on stimulation location and electrode configuration.</p> <p>Conclusions</p> <p>A ring electrode configuration is ideal for IES. Stimulation near the urethral meatus or prostate can activate the pudendal afferent fibers at the lowest intensities, and allowed selective activation of the dorsal penile nerve or cranial sensory nerve, respectively. Electrode location was a more important factor than electrode configuration for determining stimulation threshold intensity and nerve selectivity.</p

Molecular Interactions of Prodiginines with the BH3 Domain of Anti-Apoptotic Bcl-2 Family Members

Prodigiosin and obatoclax, members of the prodiginines family, are small molecules with anti-cancer properties that are currently under preclinical and clinical trials. The molecular target(s) of these agents, however, is an open question. Combining experimental and computational techniques we find that prodigiosin binds to the BH3 domain in some BCL-2 protein families, which play an important role in the apoptotic programmed cell death. In particular, our results indicate a large affinity of prodigiosin for MCL-1, an anti-apoptotic member of the BCL-2 family. In melanoma cells, we demonstrate that prodigiosin activates the mitochondrial apoptotic pathway by disrupting MCL-1/BAK complexes. Computer simulations with the PELE software allow the description of the induced fit process, obtaining a detailed atomic view of the molecular interactions. These results provide new data to understand the mechanism of action of these molecules, and assist in the development of more specific inhibitors of anti-apoptotic BCL-2 proteins.Spanish government and the European Union (FIS-PI10/00338) and from the ERC-2009-Adg 25027-PELE European project

Fluorescence-Tracking of Activation Gating in Human ERG Channels Reveals Rapid S4 Movement and Slow Pore Opening

Background: hERG channels are physiologically important ion channels which mediate cardiac repolarization as a result of their unusual gating properties. These are very slow activation compared with other mammalian voltage-gated potassium channels, and extremely rapid inactivation. The mechanism of slow activation is not well understood and is investigated here using fluorescence as a direct measure of S4 movement and pore opening. Methods and Findings: Tetramethylrhodamine-5-maleimide (TMRM) fluorescence at E519 has been used to track S4 voltage sensor movement, and channel opening and closing in hERG channels. Endogenous cysteines (C445 and C449) in the S1–S2 linker bound TMRM, which caused a 10 mV hyperpolarization of the VK of activation to 227.562.0 mV, and showed voltage-dependent fluorescence signals. Substitution of S1–S2 linker cysteines with valines allowed unobstructed recording of S3–S4 linker E519C and L520C emission signals. Depolarization of E519C channels caused rapid initial fluorescence quenching, fit with a double Boltzmann relationship, F-VON, with VK,1 = 237.861.7 mV, and VK,2 = 43.567.9 mV. The first phase, VK,1, was,20 mV negative to the conductance-voltage relationship measured from ionic tail currents (G-VK = 218.361.2 mV), and relatively unchanged in a non-inactivating E519C:S620T mutant (V K = 234.461.5 mV), suggesting the fast initial fluorescence quenching tracked S4 voltage sensor movement. The second phase of rapid quenching was absent in the S620T mutant. The E519C fluorescence upon repolarizatio

Characterization of bovine embryos cultured under conditions appropriate for sustaining human naïve pluripotency.

In mammalian preimplantation development, pluripotent cells are set aside from cells that contribute to extra-embryonic tissues. Although the pluripotent cell population of mouse and human embryos can be cultured as embryonic stem cells, little is known about the pathways involved in formation of a bovine pluripotent cell population, nor how to maintain these cells in vitro. The objective of this study was to determine the transcriptomic profile related to bovine pluripotency. Therefore, in vitro derived embryos were cultured in various culture media that recently have been reported capable of maintaining the naïve pluripotent state of human embryonic cells. Gene expression profiles of embryos cultured in these media were compared using microarray analysis and quantitative RT-PCR. Compared to standard culture conditions, embryo culture in 'naïve' media reduced mRNA expression levels of the key pluripotency markers NANOG and POU5F1. A relatively high percentage of genes with differential expression levels were located on the X-chromosome. In addition, reduced XIST expression was detected in embryos cultured in naïve media and female embryos contained fewer cells with H3K27me3 foci, indicating a delay in X-chromosome inactivation. Whole embryos cultured in one of the media, 5iLA, could be maintained until 23 days post fertilization. Together these data indicate that 'naïve' conditions do not lead to altered expression of known genes involved in pluripotency. Interestingly, X-chromosome inactivation and development of bovine embryos were dependent on the culture conditions

Running GAGs: myxoid matrix in tumor pathology revisited: What’s in it for the pathologist?

Ever since Virchow introduced the entity myxoma, abundant myxoid extracellular matrix (ECM) has been recognized in various reactive and neoplastic lesions. Nowadays, the term “myxoid” is commonly used in daily pathological practice. But what do today’s pathologists mean by it, and what does the myxoid ECM tell the pathologist? What is known about the exact composition and function of the myxoid ECM 150 years after Virchow? Here, we give an overview of the composition and constituents of the myxoid ECM as known so far and demonstrate the heterogeneity of the myxoid ECM among different tumors. We discuss the possible role of the predominant constituents of the myxoid ECM and attempt to relate them to differences in clinical behavior. Finally, we will speculate on the potential relevance of this knowledge in daily pathological practice

The social production of substance abuse and HIV/HCV risk: an exploratory study of opioid-using immigrants from the former Soviet Union living in New York City

<p>Abstract</p> <p>Background</p> <p>Several former Soviet countries have witnessed the rapid emergence of major epidemics of injection drug use (IDU) and associated HIV/HCV, suggesting that immigrants from the former Soviet Union (FSU) may be at heightened risk for similar problems. This exploratory study examines substance use patterns among the understudied population of opioid-using FSU immigrants in the U.S., as well as social contextual factors that may increase these immigrants' susceptibility to opioid abuse and HIV/HCV infection.</p> <p>Methods</p> <p>In-depth interviews were conducted with 10 FSU immigrants living in New York City who initiated opioid use in adolescence or young adulthood, and with 6 drug treatment providers working with this population. Informed by a grounded theory approach, interview transcripts were inductively coded and analyzed to identify key themes.</p> <p>Results</p> <p>The "trauma" of the immigration/acculturation experience was emphasized by participants as playing a critical role in motivating opioid use. Interview data suggest that substance use patterns formed in the high-risk environment of the FSU may persist as behavioral norms within New York City FSU immigrant communities - including a predilection for heroin use among youth, a high prevalence of injection, and a tolerance for syringe sharing within substance-using peer networks. Multiple levels of social context may reproduce FSU immigrants' vulnerability to substance abuse and disease such as: peer-based interactional contexts in which participants typically used opioids; community workplace settings in which some participants were introduced to and obtained opioids; and cultural norms, with roots in Soviet-era social policies, stigmatizing substance abuse which may contribute to immigrants' reluctance to seek disease prevention and drug treatment services.</p> <p>Conclusion</p> <p>Several behavioral and contextual factors appear to increase FSU immigrants' risk for opioid abuse, IDU and infectious disease. Further research on opioid-using FSU immigrants is warranted and may help prevent increases in HIV/HCV prevalence from occurring within these communities.</p