357 research outputs found
Phase specific suppression of neutrophil function in hibernating Syrian hamster
Hibernation consists of alternating periods of reduced metabolism (torpor) with brief periods of metabolism similar to summer euthermia (arousal). The function of the innate immune system is reduced during hibernation, of which the underlying mechanisms are incompletely understood. Here, we studied neutrophil functionality during hibernation in Syrian hamsters. The inflammatory response to LPS-induced endotoxemia is inhibited in hibernation, partly mediated by reduced IL-6 production in early arousal. Furthermore, neutrophil pathogen binding, phagocytosis and oxidative burst is profoundly reduced in early arousal. Functionality of both summer and early arousal neutrophils was repressed in plasma from early arousal and mixed plasma from early arousal and summer euthermic, but restored by summer euthermic plasma, signifying that a plasma factor in early arousal inhibits TLR-recognition. Identification of the inhibiting factor may offer a target to modulate neutrophil function with relevance to (auto-)inflammatory diseases
EORTC (30885) randomised phase III study with recombinant interferon alpha and recombinant interferon alpha and gamma in patients with advanced renal cell carcinoma. The EORTC Genitourinary Group.
In the treatment of renal cell carcinoma both complete (CRs) and partial remissions (PRs) have been obtained using recombinant (r) interferon alpha (IFN-alpha), with response rates ranging from 0 to 31% (mean 16%). rIFN-gamma is a potent immunostimulating agent, but the clinical experience of its use is limited and results are conflicting. In a phase II study with the combination of rIFN-alpha 2c (Boehringer Ingelheim) and rIFN-gamma (Genentech, supplied by Boehringer Ingelheim) in 31 eligible patients, a response rate of 25% was recorded. Based on this observation a randomised phase III study was initiated to investigate the possible advantage of the addition rIFN-gamma to rIFN-alpha 2c treatment. Treatment consisted of rIFN-alpha 2c 30 micrograms m-2 = 10 x 10(6) IU m-2 s.c. twice weekly in arm A and the same dose of rIFN-alpha combined with rIFN-gamma 100 micrograms m-2 = 2 x 10(6) IU m-2 in arm B. Eligibility criteria included documented progression of disease; patients with bone lesions only and overt central nervous system metastases were excluded. Between November 1988 and September 1990, 102 patients were entered into the study. An interim analysis showed a response in 7/53 (13%) patients (two CRs and five PRs) in the rIFN-alpha 2c monotherapy arm and in 2/45 (4%) (one CR and one PR) patients in the combination arm. This difference was not statistically significant (P = 0.17). The probability of missing an eventual 10% advantage for the combination is 0.001. The numbers are insufficient to rule out a negative effect of the addition of rIFN-gamma. The dose intensity of IFN-alpha 2c for the two treatment arms was the same. The addition of rIFN-gamma does not improve the response rate of rIFN-alpha 2c monotherapy. A possible detrimental effect cannot be excluded
Intravital correlated microscopy reveals differential macrophage and microglial dynamics during resolution of neuroinflammation
Many brain diseases involve activation of resident and peripheral immune cells to clear damaged and dying neurons. Which immune cells respond in what way to cues related to brain disease, however, remains poorly understood. To elucidate these in vivo immunological events in response to brain cell death we used genetically targeted cell ablation in zebrafish. Using intravital microscopy and large-scale electron microscopy, we defined the kinetics and nature of immune responses immediately following injury. Initially, clearance of dead cells occurs by mononuclear phagocytes, including resident microglia and macrophages of peripheral origin, whereas amoeboid microglia are exclusively involved at a later stage. Granulocytes, on the other hand, do not migrate towards the injury. Remarkably, following clearance, phagocyte numbers decrease, partly by phagocyte cell death and subsequent engulfment of phagocyte corpses by microglia. Here, we identify differential temporal involvement of microglia and peripheral macrophages in clearance of dead cells in the brain, revealing the chronological sequence of events in neuroinflammatory resolution. Remarkably, recruited phagocytes undergo cell death and are engulfed by microglia. Because adult zebrafish treated at the larval stage lack signs of pathology, it is likely that this mode of resolving immune responses in brain contributes to full tissue recovery. Therefore, these findings suggest that control of such immune cell behavior could benefit recovery from neuronal damage.</p
Late gadolinium enhancement and adverse outcomes in a contemporary cohort of adult survivors of tetralogy of Fallot
Objective:
Myocardial fibrosis has been associated with poorer outcomes in tetralogy of Fallot, however only a handful of studies have assessed its significance in the current era. Our aim was to quantify the amount of late gadolinium enhancement in both the LV and RV in a contemporary cohort of adults with surgically repaired tetralogy of Fallot, and assess the relationship with adverse clinical outcomes.
Design:
Single centre cohort study
Setting:
National tertiary referral center
Patients: One hundred fourteen patients with surgically repaired tetralogy of Fallot with median age 29.5 years (range 17.5-64.2). Prospective follow-up for mean 2.4 years (SD 1.29).
Interventions:
Cardiovascular magnetic resonance was performed, and late gadolinium enhancement mass was estimated for the LV using the 5-SD remote myocardium method, and for the RV using a segmental scoring system. Cohort characterization was determined through the use of a computerized database.
Outcome measures:
Survival analysis from time of scan to first adverse event, defined as an episode of atrial arrhythmia, sustained ventricular arrhythmia, hospitalization with heart failure, or implantable cardioverter-defibrillator insertion.
Results:
Eleven patients experienced an adverse outcome in the follow-up period, although there were no deaths. LV late gadolinium enhancement was associated with adverse outcomes in a univariate model (Pâ=â.027). However, when adjusted for age at scan the significant variables included NYHA class (Pâ=â.006), peak oxygen uptake (Pâ=â.028), number of prior sternotomies (Pâ=â.044), and higher indexed RV and LV end diastolic volumes (Pâ=â.002 and Pâ<â.001), but not RV or LV late gadolinium enhancement.
Conclusions:
Formal quantification of late gadolinium enhancement is not currently as helpful in ascertaining prognosis compared to other, more easily assessed parameters in a contemporary cohort of tetralogy of Fallot survivors, however assessment particularly of the LV holds promise for the future
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Passive tracer transport relevant to the TRACE A experiment
This paper explores some of the mechanisms governing the accumulation of passive tracers over the tropical southern Atlantic Ocean during the northern hemisphere fall season. There has been a pioneering observation regarding ozone maxima over the South Atlantic during austral spring. The understanding of the formation of this maxima has been the prime motivation for this study. Using a global model as a frame of reference, we have carried out three kinds of experiments during the period of the Transport and Atmospheric Chemistry Near the Equator-Atlantic (TRACE A) project of 1992. The first of these is a simple advection of total ozone (a passive tracer) in time using the Florida State University global spectral model. Integration over the period of roughly 1 week showed that the model quite closely replicates the behavior of the observed total ozone from the total ozone mapping spectrometer (TOMS). This includes many of the changes in the features of total ozone over the tropical and subtropical region of the southern Atlantic Ocean. These studies suggest a correlation of 0.8 between the observed ozone over this region and ozone modeled from âdynamics alone,â i.e., without recourse to any photochemistry. The second series of experiments invoke sustained sources of a tracer over the biomass burn region of Africa and Brazil. Furthermore, sustained sources were also introduced in the active frontal âdescending airâ region of the southern hemisphere and over the Asian monsoon's east-west circulation. These experiments strongly suggest that air motions help to accumulate tracer elements over the tropical southern Atlantic Ocean. A third series of experiments address what may be required to improve the deficiencies of the vertical stratification of ozone predicted by the model over the flight region of the tropical southern Atlantic during TRACE A. Here we use the global model to optimally derive plausible accumulation of burn elements over the fire count regions of Brazil and Africa to provide passive tracer advections to closely match what was observed from reconnaissance aircraft-based measurements of ozone over the tropical southern Atlantic Ocean.Engineering and Applied Science
Intravital correlated microscopy reveals differential macrophage and microglial dynamics during resolution of neuroinflammation
Many brain diseases involve activation of resident and peripheral immune cells to clear damaged and dying neurons. Which immune cells respond in what way to cues related to brain disease, however, remains poorly understood. To elucidate these in vivo immunological events in response to brain cell death we used genetically targeted cell ablation in zebrafish. Using intravital microscopy and large-scale electron microscopy, we defined the kinetics and nature of immune responses immediately following injury. Initially, clearance of dead cells occurs by mononuclear phagocytes, including resident microglia and macrophages of peripheral origin, whereas amoeboid microglia are exclusively involved at a later stage. Granulocytes, on the other hand, do not migrate towards the injury. Remarkably, following clearance, phagocyte numbers decrease, partly by phagocyte cell death and subsequent engulfment of phagocyte corpses by microglia. Here, we identify differential temporal involvement of microglia and peripheral macrophages in clearance of dead cells in the brain, revealing the chronological sequence of events in neuroinflammatory resolution. Remarkably, recruited phagocytes undergo cell death and are engulfed by microglia. Because adult zebrafish treated at the larval stage lack signs of pathology, it is likely that this mode of resolving immune responses in brain contributes to full tissue recovery. Therefore, these findings suggest that control of such immune cell behavior could benefit recovery from neuronal damage
InterFace : A software package for face image warping, averaging, and principal components analysis
We describe InterFace, a software package for research in face recognition. The package supports image warping, reshaping, averaging of multiple face images, and morphing between faces. It also supports principal components analysis (PCA) of face images, along with tools for exploring the âface spaceâ produced by PCA. The package uses a simple graphical user interface, allowing users to perform these sophisticated image manipulations without any need for programming knowledge. The program is available for download in the form of an app, which requires that users also have access to the (freely available) MATLAB Runtime environment
Tetralogy of Fallot
Tetralogy of Fallot is a congenital cardiac malformation that consists of an interventricular communication, also known as a ventricular septal defect, obstruction of the right ventricular outflow tract, override of the ventricular septum by the aortic root, and right ventricular hypertrophy
4D cardiovascular magnetic resonance velocity mapping of alterations of right heart flow patterns and main pulmonary artery hemodynamics in tetralogy of Fallot
<p>Abstract</p> <p>Background</p> <p>To assess changes in right heart flow and pulmonary artery hemodynamics in patients with repaired Tetralogy of Fallot (rTOF) we used whole heart, four dimensional (4D) velocity mapping (VM) cardiovascular magnetic resonance (CMR).</p> <p>Methods</p> <p>CMR studies were performed in 11 subjects with rTOF (5M/6F; 20.1 ± 12.4 years) and 10 normal volunteers (6M/4F; 34.2 ± 13.4 years) on clinical 1.5T and 3.0T MR scanners. 4D VM-CMR was performed using PC VIPR (Phase Contrast Vastly undersampled Isotropic Projection Reconstruction). Interactive streamline and particle trace visualizations of the superior and inferior vena cava (IVC and SVC, respectively), right atrium (RA), right ventricle (RV), and pulmonary artery (PA) were generated and reviewed by three experienced readers. Main PA net flow, retrograde flow, peak flow, time-to-peak flow, peak acceleration, resistance index and mean wall shear stress were quantified. Differences in flow patterns between the two groups were tested using Fisher's exact test. Differences in quantitative parameters were analyzed with the Kruskal-Wallis rank sum test.</p> <p>Results</p> <p>4D VM-CMR was successfully performed in all volunteers and subjects with TOF. Right heart flow patterns in rTOF subjects were characterized by (a) greater SVC/IVC flow during diastole than systole, (b) increased vortical flow patterns in the RA and in the RV during diastole, and (c) increased helical or vortical flow features in the PA's. Differences in main PA retrograde flow, resistance index, peak flow, time-to-peak flow, peak acceleration and mean wall shear stress were statistically significant.</p> <p>Conclusions</p> <p>Whole heart 4D VM-CMR with PC VIPR enables detection of both normal and abnormal right heart flow patterns, which may allow for comprehensive studies to evaluate interdependencies of post-surgically altered geometries and hemodynamics.</p
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