bluuebunny/crossref_metadata_2025 huggingface dataset:
BIOMECHANICAL ANALYSIS OF THE ELBOW JOINT LOADING DURING PUSH-UP
Authors: Chou Pei-Hsi , Lou Shu-Zon , Chen Shen-Kai , Chen Hsin-Chieh , Wu Tsung-Hsien , Chou You-Li
Published: September 2009

The purpose of this study was to investigate the static and dynamic forces within the joints during push-up loading of the upper extremity.

Ten healthy male students volunteered for this study. They were asked to complete six sets of push-ups in five different hand positions. The Expert Vision Motion Analysis System with six CCD cameras, and a Kistler force plate was used to measure the relative joint position and ground reaction force.

Hand position was found to have a statistically significant effect on the axial force. The maximum axial force decreased from "normal" when hands were placed "apart" (45.0% BW, p = 0.012) or "superior" (44.5% BW, p = 0.01). Hand position had a significant effect on the flexion moment of the elbow joint. A greater reduction of flexion torque at 997.3 N-cm (p = 0.001) was experienced with hands "apart." Greater flexion torque existed throughout the cycle with hands "together" and equaled 2301.4 N-cm (p = 0.002).

This study provides information about the kinematic and kinetic patterns of the upper extremities, and how hand position affects intersegmental loading. Attention must be given to the valgus torque encountered during push-up exercises. Patients with medial collateral ligament repair and total elbow arthroplasty should be protected from such exercises immediately post-treatment.
REAL-TIME THREE-DIMENSIONAL RECONSTRUCTION FOR VOLUME-BASED SURGERY SIMULATIONS
Authors: Lee Jyh-Fa , Hsieh Ming-Shium , Kuo Chih-Wei , Tsai Ming-Dar , Ma Ming
Published: September 2009

This paper describes a three-dimensional reconstruction method to provide real-time visual responses for volume (constituted by tomographic slices) based surgery simulations. The proposed system uses dynamical data structures to record tissue triangles obtained from 3D reconstruction computation. Each tissue triangle in the structures can be modified or every structure can be deleted or allocated independently. Moreover, triangle reconstruction is optimized by only deleting or adding vertices from manipulated voxels that are classified as erosion (in which the voxels are changed from tissue to null) or generation (the voxels are changed from null to tissue). Therefore, by manipulating these structures, 3D reconstruction can be locally implemented for only manipulated voxels to achieve the highest efficiency without reconstructing tissue surfaces in the whole volume as general methods do. Three surgery simulation examples demonstrate that the proposed method can provide time-critical visual responses even under other time-consuming computations such as volume manipulations and haptic interactions.
MINIATURE MODULES FOR MULTI-LEAD ECG RECORDING
Authors: Tseng Yi-Li , Chiu Hung-Wei , Lin Tsung-Hsien , Jaw Fu-Shan
Published: September 2009

Remote monitoring systems for home health care service have become one of the hottest topics recently. Biomedical signals recorded by portable devices can be wirelessly transmitted through the Internet. In this paper, a miniature signal-condition module for ambulatory recording of electrocardiogram (ECG) signals was designed with high input impedance, high common-mode rejection ratio (CMRR), low power, appropriate amplification and filtration, and automatic suppression of offset voltage. For early detection of acute myocardial infarction (AMI), this device is extended and 12-lead ECG recording is available. Due to the modular approach, the module is accommodated for other biomedical signals recording as well if the gain and pass-band of the module are modified.
ABNORMAL MATCHING BETWEEN THE LEFT VENTRICLE AND THE ARTERIAL SYSTEM IN PATIENTS WITH ACUTE MYOCARDIAL INFARCTION AFTER THROMBOLYSIS PLUS ADJUVANT ANGIOPLASTY
Authors: Liu Chun-Peng , Wang Jia-Jung , Hu Wei-Chih , Liu Shing-Hong
Published: September 2009

The purpose of this study was to investigate the relationship between the left ventriculo–arterial coupling and the left ventricular (LV) mechanical efficiency in human hearts with acute myocardial infarction (AMI) after thrombolytic therapy combined with subsequent percutaneous coronary intervention. Twenty-six patients with post-AMI at cardiac catheterization were divided into two groups according to their resting ejection fraction (EF). The first group included 18 patients with EF greater than or equal to 50%, and the second group consisted of 8 patients with EF less than 50%. LV pressure–volume relations were measured by the conductance catheter method with preload altered by inferior vena cava obstruction in the 26 patients who received the thrombolytic therapy in 6 h and the percutaneous coronary intervention at first week after the AMI event. The ventriculo–arterial coupling relationship was determined by the ratio of the ventricular chamber elastance E es (the slope of the LV end-systolic pressure relation) and the effective arterial elastance E a (the slope of the arterial end-systolic pressure–stroke volume relation). The results showed no significant difference in the ratio of E es /E a between Group 1 (0.78 ± 0.34) and Group 2 (0.72 ± 0.22). Significant difference (p < 0.05) in the stroke work was found between Group 1 (7188 ± 1923 mmHg × ml) and Group 2 (5677 ± 670 mmHg × ml), although the potential energy in Group 1 was not significantly different from that in Group 2. We also found in the two patient groups that E es but not E a was linearly increased with the E es /E a ratio (Group 1: r = 0.84, p < 0.001 and Group 2: r = 0.76, p < 0.05). In addition, the ventricular mechanical efficiency in the infracted hearts with EF more than 50% (r = 0.71) was shown to be linearly increased with the E es /E a ratio, but not in those with EF of less than 50%. We concluded that in spite of no significant difference in the values of E es /E a between the infarct hearts with larger EF and those with smaller EF, all infarcted LV elastance but not their afterload depends linearly on E es /E a . Also, in myocardial infarcted patients with higher EF, their LV mechanical efficiency may tend to correlate linearly with the ventriculo–arterial coupling index, although the abnormal coupling between the left ventricle and arterial system still exists.
EFFECTS OF CHITOSAN/β-TCP MICROSPHERES ON RABBIT CRANIAL AND CONDYLE DEFECTS HEALING: A PRELIMINARY STUDY
Authors: Kuo Shyh Ming , Lin Li-Chun , Tsai Pei Hua , Niu Gregory Cheng-Chie , Chang Shwu Jen
Published: September 2009

Two kinds of chitosan/β-TCP microspheres were prepared; one was by a traditional emulsion technique (Group A), and the other was by a high-voltage electrostatic system (Group B). Both of the microspheres exhibited good sphericity and the β-TCP fine particles were well trapped inside the chitosan based particles. After 60-day shaking, Group A and Group B degraded by about 40% and 80% of initial weight, respectively. Two models of bone defects were created in rabbits included for a series of randomized blind pilot study. In the cranial model, two equal 10 mm diameter cranial defects were created. In condyle model, two equal 5 mm femur condyle defects were created on each hind leg, and underwent the same grafting treatment. After 4 weeks of implantation, both the cranial and condyle sites filled with Group A were shown to be surrounded by fibrous tissues with the presence of osteoblasts. In Group B, only condyle site showed the presence of osteoblasts. In contrast, fibrous tissue formation was seen on the control group after 4 weeks of healing. After 8 weeks of implantation, the condyle sites filled with Group A and Group B showed the presence of new bone formation as compared to control group. However, there was no obvious new bone formations in the cranial sites filled with both Group A and Group B. The same events were observed in the cranial sites after 12 weeks of implantation. In contrast, new bone formation was seen on the condyle sites in all three groups after 12 weeks of implantation.
INFANT MONITORING SYSTEM BASED ON ARM EMBEDDED PLATFORM
Authors: Tai Cheng-Chi , Chang Chien Jia-Ren , Wang Cheng-Yu , Chen Lung-Chi , Chou Chia-Hung , Wu Gone-Long
Published: September 2009

Since both the parents need to work and look after their babies/infants simultaneously, the families bear more workload. Thus, this paper presents an innovative infant monitoring system consisting of an embedded system platform with a Linux kernel embedded operation system using the TCP/IP protocol, a CMOS image sensor, and peripheral control systems. The key feature of the system is that it can be used to monitor the living environment and the activities of the babies and/or infants through a web browser at any time from any place in the world. In order to increase the accuracy of the temperature sensor, the measured values from the digital temperature sensor were calibrated using regression analysis methods, resulting in an accuracy of ± 0.1°C, a correlation coefficient of 0.996, and a standard deviation of 0.124. The experimental results show that the proposed concept and the resulting system are feasible.
BIODEGRADABLE BIOARTIFICIAL MATERIALS MADE BY CHITOSAN AND POLY(VINYL ALCOHOL). PART II: ENZYMATIC DEGRADABILITY AND DRUG-RELEASING ABILITY
Authors: Cristallini Caterina , Barbani Niccoletta , Bianchi Francesca , Silvestri Davide , Guerra Giulio D.
Published: September 2009

Bioartificial biodegradable materials were prepared mixing chitosan (CHI) and poly(vinyl alcohol) (PVA), then manufactured as films, and finally cross-linked with glutaraldehyde (GTA), both in the absence and in the presence of the edible hexa-alcohol sorbitol (SOR), as a plasticizer. The release of the components into water was tested by high performance liquid chromatography (HPLC); no release of CHI and scarce release of PVA were found. The water uptake was tested by measuring the swelling of the materials, after incubating them for 20 h in an atmosphere saturated with water vapor at 37°C. The swelling percentage increases with increasing CHI content in the blends, although it is the less hydrophilic polymer. This behavior was attributed to the difficulty of water to diffuse through the crystalline PVA structure, which is partially altered in the blends. The addition of SOR enhances the water sorption, as expected. The biodegradability of the materials was tested using the specific enzyme chitosanase, and was found to depend on the blend composition, as well as to be enhanced by the addition of SOR. The initial degradation rates were calculated; the maximum rates were found when the CHI to PVA ratio was 80:20 for all systems. The results of the enzymatic degradation generally agree with those of the swelling. The cross-linked blends were also tested as drug-delivery systems. The drugs chosen were the vitamin L-ascorbic acid (AsA) and the anti-cancer drug paclitaxel (PTX). The effective diffusion coefficients, D eff , were evaluated for the release of both the drugs from each material. Those of AsA are greater, of many powers of ten, than those of PTX, owing mainly to the hydrophilic nature of the first drug and to the hydrophobic of the second one. In conclusion, these materials seem available for biomedical use.
HOW TO EXTRACT THE SPATIAL CORRELATION OF AUDITORY CORTICAL EVOKED POTENTIALS ON MULTIPLE SCALP ELECTRODES IN TINNITUS PATIENTS
Authors: Lee Chung-Yi , Shih Yen-Yu , Jaw Fu-Shan
Published: September 2009

Tinnitus affects 10–15% of the population and tends to increase in frequency among older ages. The published reports have converged on that tinnitus is the sustained neuroplastic changes with aberrant activity residing in the auditory and nonauditory nervous systems that cause the sensation and problem of tinnitus. Clinically tinnitus remains as a subjective symptom and cannot be evaluated objectively. Our previous study has demonstrated the significantly different intensity dependence of auditory cortical evoked potential (ACEP) amplitudes to pure-tone stimuli recorded at some midline scalp electrodes between normal controls and tinnitus patients. Although ACEP test has been well known for its excellent temporal resolution of milliseconds and the latency and amplitude of ACEPs give ample information about the auditory processing of tinnitus, these measurements at each electrode deliver insufficient information about the spatial correlation among different cortical locations. According to the neurophysiological model of tinnitus, temporal and spatial information are both necessary and complementary to study the underlying mechanisms of problem tinnitus. Thus the purpose of this study was to demonstrate the spatial presentations of ACEP N1–P2 of normal controls and tinnitus patients. In this work, a program has been developed to translate the ACEPs recorded at 30 scalp electrodes to a two-dimensional presentation of isoelectric topography and current source density. The differences of intensity dependence about N1–P2 noted with previous study are reviewed on the two spatial presentations and compared between control subjects and tinnitus patients, while the patterns of correlation are demonstrated and compared with those recorded by functional brain imaging techniques like PET and fMRI.
PHASED MULTI-JOINT MOVEMENT OF THE INDEX FINGER DURING A FULL FLEXION CYCLE
Authors: Hou Wensheng , Wu Xiaoying , Jiang Yingtao , Zheng Jun , Zheng Xiaolin , Liang Xueling , Ye Yihong
Published: September 2009

Flexion of the index finger is a fairly complex process requiring the coordination of different joints. This study is the first attempt to investigate how the angular velocity profile of the three right index joints (DIP, PIP, and MCP) varies with respect to time during the course of flexion. Ten right-handed subjects (healthy college students between 21 and 23 years old) were recruited to participate in the experiment. Each of these human subjects was instructed to perform a flexion task with his/her right hand. Five miniaturized (5-mm diameter) reflective markers were applied to each human subject: three placed at the DIP, PIP, and MCP joints of the index finger on the side close to thumb, and the rest at the predetermined landmarks on dorsum of thumb. A high-speed camera was used to record the motion of the index finger during a paced flexion, and the instantaneous angular velocity of each joint was determined by relating the marker displacement to the frame frequency (~5 ms between two consecutive frames). Opposite to the general belief that the speed is constant throughout a flexion cycle, to our best knowledge, this study, for the first time, has revealed that the speed of multi-joint movement actually varies with time. It has been identified that during one full flexion cycle, the angular velocity of the three joints of interest undergoes five distinguishable phases, referred as phases P1 (slow), P2 (fast), P3 (slow), P4 (fast), and P5 (slow), respectively. It has also been observed that duration of each of phases P1, P2, P4, or P5 accounts for approximately 10–15% of the whole flexion cycle, while P3 lasts for nearly half a cycle. Furthermore, although the flexions of DIP, PIP, and MCP joints cycle through the same five phases, the starts of their respective phases tend to vary. In P2 and P5, flexion of MCP takes place considerably later than those of PIP and DIP, whereas DIP flexes earlier than PIP in P2. The angular velocity of each joint reaches its peaks in P2 and P4; the peak velocity of DIP occurs earlier than that of PIP or MCP in P2, whereas peak of MCP is reached later than that of PIP. Moreover, the three joints of index finger flex with different angular velocities in each of the five phases: PIP moves significantly faster than MCP in P2, whereas DIP moves faster than MCP in P4. The results from our study indicate that the multi-joint motion of index finger is an uneven course, i.e. different joints flex with different angular velocities during the flexion. The temporal features of the velocity due to a single joint or multi-joint motion provide useful information to further clarify the dexterity of finger movement.
CXCR3 Mediates Renal Th1 and Th17 Immune Response in Murine Lupus Nephritis
Authors: Steinmetz Oliver M. , Turner Jan-Eric , Paust Hans-Joachim , Lindner Matthias , Peters Anett , Heiss Kirstin , Velden Joachim , Hopfer Helmut , Fehr Susanne , Krieger Thorsten , Meyer-Schwesinger Catherine , Meyer Tobias N. , Helmchen Udo , Mittrücker Hans-Willi , Stahl Rolf A. K. , Panzer Ulf
Published: September 2009

Infiltration of T cells into the kidney is a typical feature of human and experimental lupus nephritis that contributes to renal tissue injury. The chemokine receptor CXCR3 is highly expressed on Th1 cells and is supposed to be crucial for their trafficking into inflamed tissues. In this study, we explored the functional role of CXCR3 using the MRL/MpJ-Faslpr (MRL/lpr) mouse model of systemic lupus erythematosus that closely resembles the human disease. CXCR3−/− mice were generated and backcrossed into the MRL/lpr background. Analysis of 20-wk-old CXCR3−/− MRL/lpr mice showed amelioration of nephritis with reduced glomerular tissue damage and decreased albuminuria and T cell recruitment. Most importantly, not only the numbers of renal IFN-γ-producing Th1 cells, but also of IL-17-producing Th17 cells were significantly reduced. Unlike in inflamed kidneys, there was no reduction in the numbers of IFN-γ- or IL-17-producing T cells in spleens, lymph nodes, or the small intestine of MRL/lpr CXCR3−/− mice. This observation suggests impaired trafficking of effector T cells to injured target organs, rather than the inability of CXCR3−/− mice to mount efficient Th1 and Th17 immune responses. These findings show a crucial role for CXCR3 in the development of experimental lupus nephritis by directing pathogenic effector T cells into the kidney. For the first time, we demonstrate a beneficial effect of CXCR3 deficiency through attenuation of both the Th1 and the newly defined Th17 immune response. Our data therefore identify the chemokine receptor CXCR3 as a promising therapeutic target in lupus nephritis.
The Toll-IL-1R Member Tir8/SIGIRR Negatively Regulates Adaptive Immunity against Kidney Grafts
Authors: Noris Marina , Cassis Paola , Azzollini Nadia , Cavinato Regiane , Cugini Daniela , Casiraghi Federica , Aiello Sistiana , Solini Samantha , Cassis Linda , Mister Marilena , Todeschini Marta , Abbate Mauro , Benigni Ariela , Trionfini Piera , Tomasoni Susanna , Mele Caterina , Garlanda Cecilia , Polentarutti Nadia , Mantovani Alberto , Remuzzi Giuseppe
Published: September 2009

Members of the TLR/IL-1R superfamily mediate ischemia/reperfusion injury and initiate immune response in transplanted organs. In this study, we tested the hypothesis that Toll-IL-1R8 (TIR8), a negative regulator of TLR/IL-1R highly expressed in the kidney, modulates immune cell activation underlying kidney rejection. In a mouse model of fully mismatched kidney allotransplantation in which the graft is spontaneously accepted, intragraft Tir8 expression was enhanced compared with naive kidneys. Targeted deletion of Tir8 in the graft exerted a powerful antitolerogenic action leading to acute rejection. Similarly, in a mouse model of kidney graft acceptance induced by costimulation blockade, most Tir8−/− grafts were acutely rejected. Despite similar levels of TLR4, IL-1R, and their ligands, the posttransplant ischemia/reperfusion-induced inflammatory response was more severe in Tir8−/− than in Tir8+/+ grafts and was followed by expansion and maturation of resident dendritic cell precursors. In vitro, Tir8−/− dendritic cell precursors acquired higher allostimulatory activity and released more IL-6 upon stimulation with a TLR4 ligand and TNF-α than Tir8+/+ cells, which may explain the increased frequency of antidonor-reactive T cells and the block of regulatory T cell formation in recipients of a Tir8−/− kidney. Thus, TIR8 acts locally as a key regulator of allogeneic immune response in the kidney. Tir8 expression and/or signaling in donor tissue are envisaged as a novel target for control of innate immunity and amelioration of graft survival.
Human Airway Smooth Muscle Cells from Asthmatic Individuals Have CXCL8 Hypersecretion Due to Increased NF-κB p65, C/EBPβ, and RNA Polymerase II Binding to the CXCL8 Promoter
Authors: John Alison E. , Zhu Yong M. , Brightling Christopher E. , Pang Linhua , Knox Alan J.
Published: September 2009

CXCL8 is a neutrophil and mast cell chemoattractant that is involved in regulating inflammatory cell influx in asthma. Here, we investigated the transcriptional mechanism involved in CXCL8 induction by TNF-α in cultured human airway smooth muscle (HASM) cells and compared these in cells from nonasthmatic and asthmatic individuals. Transfection studies with mutated CXCL8 promoter constructs identified NF-κB, activating protein-1, and CAAT/enhancer binding protein (C/EBP)β as key transcription factors, and binding of these three transcription factors to the CXCL8 promoter after TNF-α stimulation was confirmed by chromatin immunoprecipitation analysis. Cells derived from asthmatic individuals produced significantly higher levels of CXCL8 than nonasthmatic cells both basally and following 24 h of stimulation with TNF-α (p < 0.001). Furthermore, chromatin immunoprecipitation studies detected increased binding of NF-κB p65 and RNA polymerase II to the CXCL8 promoter of asthmatic HASM cells both in the presence and absence of TNF-α stimulation. This was not due to either an increased activation or phosphorylation of NF-κB per se or to an increase in its translocation to the nucleus. Increased binding of C/EBPβ to the CXCL8 promoter of unstimulated cells was also detected in the asthmatic HASM cells. Collectively these studies show that HASM cells from asthmatic individuals have increased CXCL8 production due to the presence of a transcription complex on the CXCL8 promoter, which contains NF-κB, C/EBPβ, and RNA polymerase II. This is the first description of an abnormality in transcription factor binding altering chemokine expression in airway structural cells in asthma.
Sustained and NK/CD4+ T Cell-Dependent Efficient Prevention of Lung Metastasis Induced by Dendritic Cells Harboring Recombinant Sendai Virus
Authors: Komaru Atsushi , Ueda Yasuji , Furuya Aki , Tanaka Sakura , Yoshida Kumi , Kato Tomonori , Kinoh Hiroaki , Harada Yui , Suzuki Hiroyoshi , Inoue Makoto , Hasegawa Mamoru , Ichikawa Tomohiko , Yonemitsu Yoshikazu
Published: September 2009

We recently demonstrated efficient antitumor immunity against murine tumors using dendritic cells (DCs) activated by recombinant Sendai viruses (rSeVs), and proposed a new concept, “immunostimulatory virotherapy,” for cancer immunotherapy. However, there has been little information on the efficacy of this method in preventing metastatic diseases. In this study, we investigated the efficacy of vaccinating DCs activated by fusion gene-deleted nontransmissible rSeV (rSeV/dF) using a murine model of lung metastasis. Bolus and i.v. administration of DCs harboring rSeV/dF-expressing GFP without pulsation of tumor Ag (DC-rSeV/dF-GFP) 2 days before tumor inoculation showed efficient prevention against lung metastasis of c1300 neuroblastoma, but not of RM-9 prostatic cancer. We found that the timing of DC therapy was critical for the inhibition of pulmonary metastasis of RM-9, and that the optimal effect of DCs was seen 28 days before tumor inoculation. Interestingly, the antimetastatic effect was sustained for over 3 mo, even when administered DCs were already cleared from the lung and organs related to the immune system. Although NK cell activity had already declined to baseline at the time of tumor inoculation, Ab-mediated depletion studies revealed that CD4+ cells as well as the presence of, but not the activation of, NK cells were crucial to the prevention of lung metastasis. These results are the first demonstration of efficient inhibition of lung metastasis via bolus administration of virally activated DCs that was sustained and NK/CD4+ cell-dependent, and may suggest a potentially new mechanism of DC-based immunotherapy for advanced malignancies.
P2Y
2
Receptor Transcription Is Increased by NF-κB and Stimulates Cyclooxygenase-2 Expression and PGE2 Released by Intestinal Epithelial Cells
Authors: Degagné Emilie , Grbic Djordje M. , Dupuis Andrée-Anne , Lavoie Elise G. , Langlois Christine , Jain Nishant , Weisman Gary A. , Sévigny Jean , Gendron Fernand-Pierre
Published: September 2009

Inflammatory stresses associated with inflammatory bowel diseases up-regulate P2Y2 mRNA receptor expression in the human colon adenocarcinoma cell line Caco-2, the noncancerous IEC-6 cells and in colonic tissues of patient suffering from Crohn’s disease and ulcerative colitis. However, the transcriptional events regulating P2Y2 receptor (P2Y2R) expression are not known. We have identified a putative transcription start site in the P2Y2R gene and demonstrated acetylation of Lys14 on histone H3 and Lys8 on histone H4, thus suggesting that the chromatin associated with the P2Y2 promoter is accessible to transcription factors. We also showed that the transcription factor NF-κB p65 regulates P2Y2R transcription under both proinflammatory and basal conditions. A NF-κB-responsive element was identified at −181 to −172 bp in the promoter region of P2Y2. Hence, activation of P2Y2R by ATP and UTP stimulated cyclooxygenase-2 expression and PGE2 secretion by intestinal epithelial cells. These findings demonstrate that P2Y2R expression is regulated during intestinal inflammation through an NF-κB p65-dependent mechanism and could contribute not only to inflammatory bowel disease but also to other inflammatory diseases by regulating PG release.
The ssRNA Genome of Human Rhinovirus Induces a Type I IFN Response but Fails to Induce Maturation in Human Monocyte-Derived Dendritic Cells
Authors: Schrauf Catharina , Kirchberger Stefanie , Majdic Otto , Seyerl Maria , Zlabinger Gerhard-Johann , Stuhlmeier Karl Manfred , Sachet Monika , Seipelt Joachim , Stöckl Johannes
Published: September 2009

Dendritic cells (DCs) use pattern recognition receptors to sense invading viruses and triggering of these receptors induces a maturation program. Human rhinoviruses (HRVs) belong to the family of Picornaviridae, which have a single-stranded, coding RNA genome. Because HRV does not replicate in DCs, we used genomic RNA from HRV in this study to analyze the impact of natural occurring viral ssRNA on DC function. We found that transfection of human monocyte-derived DCs with viral ssRNA induced type I IFN production but failed to activate the NF-κB pathway in DCs. In line with this observation, the up-regulation of typical maturation markers such as CD83 or the production of the proinflammatory cytokines IL-12p40, IL-6, and TNF-α was not detectable. Most importantly, the T cell stimulatory capacity of viral ssRNA-treated DCs was not enhanced and remained at the level of immature DCs. Taken together, our results demonstrate that viral ssRNA efficiently activates the innate defense arm of DCs, whereas it is insufficient to activate the stimulatory capacity of DCs for the adaptive defense responses.
Cell Cycle Progression following Naive T Cell Activation Is Independent of Jak3/Common γ-Chain Cytokine Signals
Authors: Shi Min , Lin Tsung H. , Appell Kenneth C. , Berg Leslie J.
Published: September 2009

T cell proliferation following activation is an essential aspect of the adaptive immune response. Multiple factors, such as TCR signaling, costimulation, and signals from cytokines, each contribute to determine the magnitude of T cell expansion. In this report, we examine in detail the role of Jak3/common γ-chain-dependent cytokines in promoting cell cycle progression and proliferation of naive T cells. Using naive CD4+ T cells from Jak3-deficient mice and wild-type CD4+ T cells treated with a small molecule inhibitor of Jak3, we find that these cytokine signals are not required for proliferation; instead, they are important for the survival of activated T cells. In addition, we show that the percentage of cells entering the cell cycle and the percentage of cells in each round of cell division are comparable between Jak3-deficent and wild-type T cells. Furthermore, cell cycle progression and the regulated expression of key cell cycle proteins are independent of Jak3/common γ-chain cytokine signals. These findings hold true over a wide range of TCR signal strengths. However, when CD28 costimulatory signals, but not TCR signals, are limiting, Jak3-dependent cytokine signals become necessary for the proliferation of naive T cells. Because CD28 signaling has been found to be dispensable for autoreactive T cell responses, these data suggest the potential for interfering with autoimmune T cell responses by inhibition of Jak3 signaling.
The Inhibitory FcγIIb Receptor Dampens TLR4-Mediated Immune Responses and Is Selectively Up-regulated on Dendritic Cells from Rheumatoid Arthritis Patients with Quiescent Disease
Authors: Wenink Mark H. , Santegoets Kim C. M. , Roelofs Mieke F. , Huijbens Richard , Koenen Hans J. P. M. , van Beek Ronald , Joosten Irma , Meyer-Wentrup Friederike , Mathsson Linda , Ronnelid Johan , Adema Gosse J. , Bonvini Ezio , Koenig Scott , van den Berg Wim B. , van Riel Piet L. C. M. , Radstake Timothy R. D. J.
Published: September 2009

Rheumatoid arthritis (RA) is a common autoimmune disease leading to profound disability and premature death. Although a role for FcγRs and TLRs is accepted, their precise involvement remains to be elucidated. FcγRIIb is an inhibitory FcR important in the maintenance of tolerance. We hypothesized that the inhibitory FcγRIIb inhibits TLR responses on monocyte-derived dendritic cells (DC) and serves as a counterregulatory mechanism to dampen inflammation, and we surmised that this mechanism might be defective in RA. The expression of the inhibitory FcγRIIb was found to be significantly higher on DCs from RA patients having low RA disease activity in the absence of treatment with antirheumatic drugs. The expression of activating FcγRs was similarly distributed among all RA patients and healthy controls. Intriguingly, only DCs with a high expression of FcγRIIb were able to inhibit TLR4-mediated secretion of proinflammatory cytokines when stimulated with immune complexes. In addition, when these DCs were coincubated with the combination of a TLR4 agonist and immune complexes, a markedly inhibited T cell proliferation was apparent, regulatory T cell development was promoted, and T cells were primed to produce high levels of IL-13 compared with stimulation of the DCs with the TLR4 agonist alone. Blocking FcγRIIb with specific Abs fully abrogated these effects demonstrating the full dependence on the inhibitory FcγRIIb in the induction of these phenomena. This TLR4-FcγRIIb interaction was shown to dependent on the PI3K and Akt pathway.
Alum Induces Innate Immune Responses through Macrophage and Mast Cell Sensors, But These Sensors Are Not Required for Alum to Act As an Adjuvant for Specific Immunity
Authors: McKee Amy S. , Munks Michael W. , MacLeod Megan K. L. , Fleenor Courtney J. , Van Rooijen Nico , Kappler John W. , Marrack Philippa
Published: September 2009

To understand more about how the body recognizes alum we characterized the early innate and adaptive responses in mice injected with the adjuvant. Within hours of exposure, alum induces a type 2 innate response characterized by an influx of eosinophils, monocytes, neutrophils, DCs, NK cells and NKT cells. In addition, at least 13 cytokines and chemokines are produced within 4 h of injection including IL-1β and IL-5. Optimal production of some of these, including IL-1β, depends upon both macrophages and mast cells, whereas production of others, such as IL-5, depends on mast cells only, suggesting that both of these cell types can detect alum. Alum induces eosinophil accumulation partly through the production of mast cell derived IL-5 and histamine. Alum greatly enhances priming of endogenous CD4 and CD8 T cells independently of mast cells, macrophages, and of eosinophils. In addition, Ab levels and Th2 bias was similar in the absence of these cells. We found that the inflammation induced by alum was unchanged in caspase-1-deficient mice, which cannot produce IL-1β. Furthermore, endogenous CD4 and CD8 T cell responses, Ab responses and the Th2 bias were also not impacted by the absence of caspase-1 or NLRP3. These data suggest that activation of the inflammasome and the type 2 innate response orchestrated by macrophages and mast cells in vivo are not required for adjuvant effect of alum on endogenous T and B cell responses.
Exogenous Pentraxin 3 Restores Antifungal Resistance and Restrains Inflammation in Murine Chronic Granulomatous Disease
Authors: D'Angelo Carmen , De Luca Antonella , Zelante Teresa , Bonifazi Pierluigi , Moretti Silvia , Giovannini Gloria , Iannitti Rossana Giulietta , Zagarella Silvia , Bozza Silvia , Campo Silvia , Salvatori Giovanni , Romani Luigina
Published: September 2009

Chronic granulomatous disease (CGD) is a primary immunodeficiency characterized by life-threatening bacterial and fungal infections and hyperinflammation. The susceptibility to aspergillosis in experimental CGD (p47phox−/− mice) is associated with the failure to control the inherent inflammatory response to the fungus and to restrict the activation of inflammatory Th17 cells. We assessed whether pentraxin (PTX)3, a member of a family of multimeric pattern-recognition proteins with potent anti-Aspergillus activity, could limit pathogenic inflammation in p47phox−/− mice by curbing the IL–23/Th17 inflammatory axis in response to the fungus. We found that the production of PTX3 was delayed in CGD mice in infection but exogenous administration of PTX3 early in infection restored antifungal resistance and restrained the inflammatory response to the fungus. This occurred through down-regulation of IL-23 production by dendritic cells and epithelial cells which resulted in limited expansion of IL-23R+ γδ+ T cells producing IL-17A and the emergence of Th1/Treg responses with minimum pathology. Thus, PTX3 could be therapeutically used for the exploitation of NADPH-independent mechanism(s) of antifungal immune protection with limited immunopathology in CGD.
Induction of Alloantigen-Specific Human T Regulatory Cells by Vasoactive Intestinal Peptide
Authors: Pozo David , Anderson Per , Gonzalez-Rey Elena
Published: September 2009

T regulatory cells (Tregs) are instrumental in the maintenance of immunological tolerance. Although Treg-based immunotherapy proved successful in preclinical autoimmunity and transplantation, factors involved in the generation of human Ag-specific Tregs are poorly known. In this study, we show that treatment of human CD4+CD25− T cells with the cytokine-like vasoactive intestinal peptide (VIP) during in vitro stimulation induces an anergic FoxP3+CD4+CD25high T cell subset displaying potent regulatory activities against allospecific effector T cells, irrespective of the presence of naturally occurring Tregs. VIP-tolerant T cells are characterized by incapability to progress to S phase of cell cycle during stimulation with HLA-disparate APCs by negatively affecting the synthesis of cyclins D3 and E, the activation of cyclin-dependent kinases (cdk)2 and cdk4, and the down-regulation of the cdk inhibitor p27kip1. VIP interaction with the type 1 VIP receptor and subsequent activation of cAMP/protein kinase A pathway play a major role in all these effects. Moreover, VIP-tolerant T cells protect against acute graft-vs-host disease in a mouse model of allogeneic bone marrow transplantation. The infusion of VIP-tolerant T cells together with the graft significantly reduces the clinical signs and mortality rate typical of the graft-vs-host disease. These effects are mediated by impairing allogeneic haplotype-specific responses of donor CD4+ cells in the transplanted animals. Our results suggest that including alloantigen-specific VIP-generated Tregs may be a valuable tool in therapeutic interventions to promote immunotolerance toward allogeneic grafts and to reduce the need of general immunosuppressive drugs.
IL-11 Regulates Autoimmune Demyelination
Authors: Gurfein Blake T. , Zhang Yueting , López Carolina B. , Argaw Azeb Tadesse , Zameer Andleeb , Moran Thomas M. , John Gareth R.
Published: September 2009

Current therapies for the autoimmune demyelinating disease multiple sclerosis (MS) target inflammation, but do not directly address neuroprotection or lesion repair. Cytokines of the gp130 family regulate survival and differentiation of both neural and immune cells, and we recently identified expression of the family member IL-11 in active MS plaques. In this study, we show that IL-11 regulates the clinical course and neuropathology of experimental autoimmune encephalomyelitis, a demyelinating model that mimics many of the clinical and pathologic features of MS. Importantly, the effects of IL-11 are achieved via a combination of immunoregulation and direct neuroprotection. IL-11R-α-null (IL-11Rα−/−) mice displayed a significant increase in clinical severity and neuropathology of experimental autoimmune encephalomyelitis compared with wild-type littermates. Inflammation, demyelination, and oligodendrocyte and neuronal loss were all exacerbated in IL-11Ra−/− animals. Conversely, wild-type mice treated with IL-11 displayed milder clinical signs and neuropathology than vehicle-treated controls. In cocultures of murine myelin oligodendrocyte glycoprotein35–55-specific CD4+ T lymphocytes and CD11c+ APCs, IL-11 treatment resulted in a significant decrease in T cell-derived effector cytokine production. This effect was generated via modulation of CD11c+ APC-mediated lymphocyte activation, and was associated with a decrease in the size of the CD11c+ cell population. Conversely, IL-11 strongly reduced apoptosis and potentiated mitosis in primary cultures of mouse oligodendrocyte progenitors. Collectively, these data reveal that IL-11 regulates inflammatory demyelination via a unique combination of immunoregulation and neuroprotection. IL-11 signaling may represent a therapeutic avenue to restrict CNS inflammation and potentiate oligodendrocyte survival in autoimmune demyelinating disease.
Quantifying Thymic Export: Combining Models of Naive T Cell Proliferation and TCR Excision Circle Dynamics Gives an Explicit Measure of Thymic Output
Authors: Bains Iren , Thiébaut Rodolphe , Yates Andrew J. , Callard Robin
Published: September 2009

Understanding T cell homeostasis requires knowledge of the export rate of new T cells from the thymus, a rate that has been surprisingly difficult to estimate. TCR excision circle (TREC) content has been used as a proxy for thymic export, but this quantity is influenced by cell division and loss of naive T cells and is not a direct measure of thymic export. We present in this study a method for quantifying thymic export in humans by combining two simple mathematical models. One uses Ki67 data to calculate the rate of peripheral naive T cell production, whereas the other tracks the dynamics of TRECs. Combining these models allows the contributions of the thymus and cell division to the daily production rate of T cells to be disentangled. The method is illustrated with published data on Ki67 expression and TRECs within naive CD4+ T cells in healthy individuals. We obtain a quantitative estimate for thymic export as a function of age from birth to 20 years. The export rate of T cells from the thymus follows three distinct phases, as follows: an increase from birth to a peak at 1 year, followed by rapid involution until ∼8 years, and then a more gradual decline until 20 years. The rate of involution shown by our model is compatible with independent estimates of thymic function predicted by thymic epithelial space. Our method allows nonintrusive estimation of thymic output on an individual basis and may provide a means of assessing the role of the thymus in diseases such as HIV.
Formula Feeding Skews Immune Cell Composition toward Adaptive Immunity Compared to Breastfeeding
Authors: Andersson Yvonne , Hammarström Marie-Louise , Lönnerdal Bo , Graverholt Gitte , Fält Helen , Hernell Olle
Published: September 2009

The ontogeny of the immune system and the effect thereon by type of infant feeding is incompletely understood. We analyzed frequencies and composition of immune cells in blood of breastfed (BF) and formula-fed (FF) infants at 1.5, 4, and 6 mo of age. Three formulas with the same protein concentration but with varying levels of α-lactalbumin and caseinoglycomacropeptide were compared. Twenty-nine exclusively BF infants served as reference, and 17 infants in each formula group completed the study. Whole blood and PBMCs were analyzed by flow cytometry and immunoflow cytometry, respectively. Leukocyte count of BF infants increased with time due to increased frequency of neutrophils. Lymphocyte count was high at 1.5 mo and was unchanged over time, as were the relative proportions of CD4+ αβT cells, CD8+ αβT cells, B cells, NK cells, and γδT cells. Most CD45R0+CD3+ cells were HLA-DR− and hence memory cells. Compared with breastfeeding, formula feeding resulted in a significant decrease in proportion of NK cells, but a significant increase in naive CD4+ αβT cells and an elevated CD4-to-CD8 ratio, that is, 3.3 in the combined FF groups compared with 2.6 in the BF group. No significant differences were found between the three groups of FF infants. In conclusion, blood cells of lymphoid lineage did not change significantly in frequencies or composition from 1.5 to 6 mo of age in BF infants. In contrast, FF infants displayed an ongoing maturation of adaptive immunity cells and a delayed recruitment of innate immunity cells as compared with BF infants.
Fluid Flow Regulates Stromal Cell Organization and CCL21 Expression in a Tissue-Engineered Lymph Node Microenvironment
Authors: Tomei Alice A. , Siegert Stefanie , Britschgi Mirjam R. , Luther Sanjiv A. , Swartz Melody A.
Published: September 2009

In the paracortex of the lymph node (LN), T zone fibroblastic reticular cells (TRCs) orchestrate an immune response by guiding lymphocyte migration both physically, by creating three-dimensional (3D) cell networks, and chemically, by secreting the chemokines CCL19 and CCL21 that direct interactions between CCR7-expressing cells, including mature dendritic cells and naive T cells. TRCs also enwrap matrix-based conduits that transport fluid from the subcapsular sinus to high endothelial venules, and fluid flow through the draining LN rapidly increases upon tissue injury or inflammation. To determine whether fluid flow affects TRC organization or function within a 3D network, we regenerated the 3D LN T zone stromal network by culturing murine TRC clones within a macroporous polyurethane scaffold containing type I collagen and Matrigel and applying slow interstitial flow (1–23 μm/min). We show that the 3D environment and slow interstitial flow are important regulators of TRC morphology, organization, and CCL21 secretion. Without flow, CCL21 expression could not be detected. Furthermore, when flow through the LN was blocked in mice in vivo, CCL21 gene expression was down-regulated within 2 h. These results highlight the importance of lymph flow as a homeostatic regulator of constitutive TRC activity and introduce the concept that increased lymph flow may act as an early inflammatory cue to enhance CCL21 expression by TRCs, thereby ensuring efficient immune cell trafficking, lymph sampling, and immune response induction.
Matrix Metalloproteinase (MMP)-9, but Not MMP-2, Is Involved in the Development and Progression of C Protein-Induced Myocarditis and Subsequent Dilated Cardiomyopathy
Authors: Matsumoto Yoh , Park Il-Kwon , Kohyama Kuniko
Published: September 2009

Repeated or continuous inflammation of the heart is one of the initiation factors for dilated cardiomyopathy (DCM). In previous studies, we established a DCM animal model by immunizing rats with cardiac C protein. In the present study, we analyze the role of matrix metalloproteinases (MMPs) in experimental autoimmune carditis (EAC) and subsequent DCM to elucidate the pathomechanisms of this disease. In this model, inflammation begins ∼9 days after immunization. At that time, MMP activities were detected by in situ zymography. Real-time PCR analysis revealed continuous up-regulation of MMP-2 mRNA from 2 wk and thereafter. MMP-9 mRNA, however, had only a transient increase at 2 wk. Double staining with in situ zymography and cell markers demonstrated that gelatinase (MMP-2 and MMP-9)-expressing cells are infiltrating macrophages during the early stage and cardiomyocytes at later stages. Minocycline, which inhibits MMP-9 activities more strongly than MMP-2, significantly suppressed EAC, but an MMP-2-specific inhibitor, TISAM, did not affect the course of the disease. Furthermore, immunohistochemical examination revealed that minocycline treatment suppressed T cell and macrophage infiltration strongly, whereas TISAM did not. These findings indicate that MMP-9, but not MMP-2, is involved in the pathogenesis of the acute phase of EAC, and further suggest that MMP-9 inhibitors, minocycline and its derivatives, may be useful therapies for EAC and DCM.
Characterization of Preexisting MAGE-A3-Specific CD4+ T Cells in Cancer Patients and Healthy Individuals and Their Activation by Protein Vaccination
Authors: Tsuji Takemasa , Altorki Nasser K. , Ritter Gerd , Old Lloyd J. , Gnjatic Sacha
Published: September 2009

Vaccination with cancer/testis Ag MAGE-A3 in the form of recombinant protein often induces specific humoral and cellular immune responses. Although Ag-specific CD4+ T cells following vaccination are detectable by cytokine production after a single in vitro stimulation, their detection before vaccination is difficult because of low frequency. In this study, we have applied a sensitive method using CD154 (CD40L) staining to detect MAGE-A3-specific CD4+ T cells. MAGE-A3-specific T cell responses were analyzed in four healthy donors, two lung cancer patients with spontaneous serum Abs to MAGE-A3, and two baseline seronegative lung cancer patients throughout vaccination with MAGE-A3 protein. MAGE-A3-specific CD4+ T cells were detected in all individuals tested, at low frequency in healthy donors and seronegative cancer patients and higher frequency in patients seropositive for MAGE-A3. Polyclonal expansion of CD154-expressing CD4+ T cells after cell sorting generated a large number of MAGE-A3-specific CD4+ T cell lines from all individuals tested, enabling full characterization of peptide specificity, HLA-restriction, and avidity. Application of this method to cancer patients vaccinated with MAGE-A3 protein with or without adjuvant revealed that protein vaccination induced oligoclonal activation of MAGE-A3-specific CD4+ T cells. It appeared that MAGE-A3 protein vaccination in the presence of adjuvant selectively expanded high avidity CD4+ T cells, whereas high avidity T cells disappeared after multiple vaccinations with MAGE-A3 protein alone.