bluuebunny/crossref_metadata_2025 huggingface dataset:
B and T Lymphocyte Attenuator Mediates Inhibition of Tumor-Reactive CD8+ T Cells in Patients After Allogeneic Stem Cell Transplantation
Authors: Hobo Willemijn , Norde Wieger J. , Schaap Nicolaas , Fredrix Hanny , Maas Frans , Schellens Karen , Falkenburg J. H. Frederik , Korman Alan J. , Olive Daniel , van der Voort Robbert , Dolstra Harry
Published: May 2012

Allogeneic stem cell transplantation (allo-SCT) can cure hematological malignancies by inducing alloreactive T cell responses targeting minor histocompatibility antigens (MiHA) expressed on malignant cells. Despite induction of robust MiHA-specific T cell responses and long-term persistence of alloreactive memory T cells specific for the tumor, often these T cells fail to respond efficiently to tumor relapse. Previously, we demonstrated the involvement of the coinhibitory receptor programmed death-1 (PD-1) in suppressing MiHA-specific CD8+ T cell immunity. In this study, we investigated whether B and T lymphocyte attenuator (BTLA) plays a similar role in functional impairment of MiHA-specific T cells after allo-SCT. In addition to PD-1, we observed higher BTLA expression on MiHA-specific CD8+ T cells compared with that of the total population of CD8+ effector-memory T cells. In addition, BTLA’s ligand, herpes virus entry mediator (HVEM), was found constitutively expressed by myeloid leukemia, B cell lymphoma, and multiple myeloma cells. Interference with the BTLA–HVEM pathway, using a BTLA blocking Ab, augmented proliferation of BTLA+PD-1+ MiHA-specific CD8+ T cells by HVEM-expressing dendritic cells. Notably, we demonstrated that blocking of BTLA or PD-1 enhanced ex vivo proliferation of MiHA-specific CD8+ T cells in respectively 7 and 9 of 11 allo-SCT patients. Notably, in 3 of 11 patients, the effect of BTLA blockade was more prominent than that of PD-1 blockade. Furthermore, these expanded MiHA-specific CD8+ T cells competently produced effector cytokines and degranulated upon Ag reencounter. Together, these results demonstrate that BTLA–HVEM interactions impair MiHA-specific T cell functionality, providing a rationale for interfering with BTLA signaling in post-stem cell transplantation therapies.
Cathelicidin-Related Antimicrobial Peptide Is Required for Effective Lung Mucosal Immunity in Gram-Negative Bacterial Pneumonia
Authors: Kovach Melissa A. , Ballinger Megan N. , Newstead Michael W. , Zeng Xianying , Bhan Urvashi , Yu Fu-shin , Moore Bethany B. , Gallo Richard L. , Standiford Theodore J.
Published: May 2012

Cathelicidins are a family of endogenous antimicrobial peptides that exert diverse immune functions, including both direct bacterial killing and immunomodulatory effects. In this study, we examined the contribution of the murine cathelicidin, cathelicidin-related antimicrobial peptide (CRAMP), to innate mucosal immunity in a mouse model of Gram-negative pneumonia. CRAMP expression is induced in the lung in response to infection with Klebsiella pneumoniae. Mice deficient in the gene encoding CRAMP (Cnlp−/−) demonstrate impaired lung bacterial clearance, increased bacterial dissemination, and reduced survival in response to intratracheal K. pneumoniae administration. Neutrophil influx into the alveolar space during K. pneumoniae infection was delayed early but increased by 48 h in CRAMP-deficient mice, which was associated with enhanced expression of inflammatory cytokines and increased lung injury. Bone marrow chimera experiments indicated that CRAMP derived from bone marrow cells rather than structural cells was responsible for antimicrobial effects in the lung. Additionally, CRAMP exerted bactericidal activity against K. pneumoniae in vitro. Similar defects in lung bacterial clearance and delayed early neutrophil influx were observed in CRAMP-deficient mice infected with Pseudomonas aeruginosa, although this did not result in increased bacterial dissemination, increased lung injury, or changes in lethality. Taken together, our findings demonstrate that CRAMP is an important contributor to effective host mucosal immunity in the lung in response to Gram-negative bacterial pneumonia.
Bacterial RNA Mediates Activation of Caspase-1 and IL-1β Release Independently of TLRs 3, 7, 9 and TRIF but Is Dependent on UNC93B
Authors: Eigenbrod Tatjana , Franchi Luigi , Muñoz-Planillo Raul , Kirschning Carsten J. , Freudenberg Marina A. , Núñez Gabriel , Dalpke Alexander
Published: May 2012

Recognition of foreign nucleic acids is important for the induction of an innate immune response against invading pathogens. Although the pathways involved in sensing bacterial DNA and viral RNA are now well established, only limited knowledge is available on mechanisms underlying recognition of bacterial RNA. It has been reported that intracellular delivery of Escherichia coli RNA activates the Nlrp3 inflammasome, but whether this is a general property of bacterial RNA remains unclear as are the pathways involved in pro–IL-1β induction and caspase-1 activation by bacterial RNA. In this study, we report that bacterial RNA from both Gram-positive and Gram-negative bacteria induces activation of caspase-1 and secretion of IL-1β by murine dendritic cells and bone-marrow derived macrophages. Stimulation was independent of the presence of 5′-triphosphate termini and occurred with whole RNA preparations from bacteria but not from eukaryotes. Induction of pro–IL-1β as well as the priming for caspase-1 activation by bacterial RNA was dependent on UNC93B, an endoplasmic reticulum protein essential for delivery of TLRs to the endosome, whereas the established nucleic acid sensing endosomal TLRs 3, 7, and 9 were dispensable. Additionally, caspase-1 activation and IL-1β production by transfected bacterial RNA were absent in MyD88-deficient cells but independent of TRIF. Thus, our data indicate the presence of a yet unidentified intracellular nucleic acid receptor involved in bacterial RNA-induced inflammasome activation and release of IL-1β.
Induction of Prolonged Asthma Tolerance by IL-10–Differentiated Dendritic Cells: Differential Impact on Airway Hyperresponsiveness and the Th2 Immunoinflammatory Response
Authors: Nayyar Aarti , Dawicki Wojciech , Huang Hui , Lu Meiping , Zhang Xiaobei , Gordon John R.
Published: May 2012

IL-10–differentiated dendritic cells (DC10s) can prevent allergen sensitization and reverse the asthma phenotype in mice with established disease. However, little is known about the time-frames over which this tolerance is effective. We report that at 2 wk after i.p. or transtracheal delivery of 1 × 106 OVA-, but not house dust mite- presenting, DC10s to OVA-asthmatic mice, significant diminution of airway hyperresponsiveness (AHR) was first apparent, whereas AHR was abrogated between 3 and 10 wk posttreatment. At 13 wk, AHR returned to pretreatment levels but could again be reversed by DC10 retreatment. The impact of a single DC10 treatment on airway eosinophil and Th2 cytokine responses to recall OVA challenge, and on OVA-specific IgE/IgG1 responses, was substantial at 3 wk posttreatment, but progressively increased thereafter, such that at 8 mo, airway eosinophil and Th2 responses to recall allergen challenge remained ∼85–95% suppressed relative to saline-treated asthmatic mice. Four biweekly DC10 treatments, whether transtracheal or i.p., reduced all asthma parameters to near background by 8 wk, whereas s.c. DC10 treatments did not affect AHR but did reduce the airway Th2 responses (i.v. DC10 had no discernible effects). Repeated challenge of the DC10-treated mice with aerosolized OVA (100 μg/ml) did not reverse tolerance, but treatment with the indoleamine-2,3-dioxygenase antagonist 1-methyltryptophan or neutralizing anti–IL-10R from days 12 to 21 after DC10 therapy partially reversed tolerance (Th2 cytokine responses, but not AHR). These findings indicate that DC10-induced Th2 tolerance in asthmatic animals is long lived, but that DC10s employ distinct mechanisms to affect AHR versus Th2 immunoinflammatory parameters.
Full-Length IL-33 Promotes Inflammation but not Th2 Response In Vivo in an ST2-Independent Fashion
Authors: Luzina Irina G. , Pickering Edward M. , Kopach Pavel , Kang Phillip H. , Lockatell Virginia , Todd Nevins W. , Papadimitriou John C. , McKenzie Andrew N. J. , Atamas Sergei P.
Published: May 2012

Expression of IL-33 is elevated in patients with pulmonary diseases, and full-length (not proteolytically processed) IL-33 is the predominant form in the lungs in health and disease. To determine whether activation of IL-33 is needed for functional effects, activities of full-length mouse and mature mouse (mm) forms of IL-33 were compared in vivo. Replication-deficient adenoviral constructs were used for gene delivery. Both isoforms caused pulmonary infiltration of lymphocytes and neutrophils, whereas mmIL-33 also caused pulmonary eosinophilia and goblet cell hyperplasia and increased expression of IL-4, IL-5, IL-13, IL-17, MCP-1, and KC. The different effects were not associated with differential release from IL-33–producing cells or by differences in subcellular distributions of IL-33 isoforms. Germline deficiency of the cell surface receptor chain ST2 abrogated the mmIL-33–induced Th2-associated effects (pulmonary eosinophilia, goblet cell hyperplasia, and increased IL-4 and IL-5), yet the lymphocytic infiltration induced by full-length mouse IL-33 or mmIL-33 was not fully abrogated by the absence of ST2. The similar effects of IL-33 isoforms were associated with comparable regulation of gene expression, notably matrix metalloproteinases 3, 10, and 13. Thus, full-length IL-33 is functionally active in vivo in an ST2-independent fashion, and its effects are partially different from those of mature IL-33. The different effects of these isoforms, particularly the pro-Th2 effects of mature IL-33, are due to differential utilization of the IL-33R chain ST2, whereas their similar effects result from regulation of gene expression.
Milk Fat Globule-Epidermal Growth Factor-Factor 8 Attenuates Neutrophil Infiltration in Acute Lung Injury via Modulation of CXCR2
Authors: Aziz Monowar , Matsuda Akihisa , Yang Weng-Lang , Jacob Asha , Wang Ping
Published: May 2012

Excessive neutrophil infiltration to the lungs is a hallmark of acute lung injury (ALI). Milk fat globule epidermal growth factor-factor 8 (MFG-E8) was originally identified for phagocytosis of apoptotic cells. Subsequent studies revealed its diverse cellular functions. However, whether MFG-E8 can regulate neutrophil function to alleviate inflammation is unknown. We therefore aimed to reveal MFG-E8 roles in regulating lung neutrophil infiltration during ALI. To induce ALI, C57BL/6J wild-type (WT) and Mfge8−/− mice were intratracheally injected with LPS (5 mg/kg). Lung tissue damage was assessed by histology, and the neutrophils were counted by a hemacytometer. Apoptotic cells in lungs were determined by TUNEL, whereas caspase-3 and myeloperoxidase activities were assessed spectrophotometrically. CXCR2 and G protein-coupled receptor kinase 2 expressions in neutrophils were measured by flow cytometry. Following LPS challenge, Mfge8−/− mice exhibited extensive lung damage due to exaggerated infiltration of neutrophils and production of TNF-α, MIP-2, and myeloperoxidase. An increased number of apoptotic cells was trapped into the lungs of Mfge8−/− mice compared with WT mice, which may be due to insufficient phagocytosis of apoptotic cells or increased occurrence of apoptosis through the activation of caspase-3. In vitro studies using MIP-2–mediated chemotaxis revealed higher migration of neutrophils of Mfge8−/− mice than those of WT mice via increased surface exposures to CXCR2. Administration of recombinant murine MFG-E8 reduces neutrophil migration through upregulation of GRK2 and downregulation of surface CXCR2 expression. Conversely, these effects could be blocked by anti-αv integrin Abs. These studies clearly indicate the importance of MFG-E8 in ameliorating neutrophil infiltration and suggest MFG-E8 as a novel therapeutic potential for ALI.
IL-2 Requirement for Human Plasma Cell Generation: Coupling Differentiation and Proliferation by Enhancing MAPK–ERK Signaling
Authors: Le Gallou Simon , Caron Gersende , Delaloy Céline , Rossille Delphine , Tarte Karin , Fest Thierry
Published: May 2012

Mature B cell differentiation involves a well-established transcription factor cascade. However, the temporal dynamics of cell signaling pathways regulating transcription factor network and coordinating cell proliferation and differentiation remain poorly defined. To gain insight into the molecular processes and extrinsic cues required for B cell differentiation, we set up a controlled primary culture system to differentiate human naive B cells into plasma cells (PCs). We identified T cell-produced IL-2 to be critically involved in ERK1/2-triggered PC differentiation. IL-2 drove activated B cell differentiation toward PC independently of its proliferation and survival functions. Indeed, IL-2 potentiated ERK activation and subsequent BACH2 and IRF8 downregulation, sustaining BLIMP1 expression, the master regulator for PC differentiation. Inhibition of the MAPK–ERK pathway, unlike STAT5 signaling, impaired IL-2–induced PC differentiation and rescued the expression profile of BACH2 and IRF8. These results identify IL-2 as a crucial early input in mature B cell fate commitment.
Constitutive Plasmacytoid Dendritic Cell Migration to the Splenic White Pulp Is Cooperatively Regulated by CCR7- and CXCR4-Mediated Signaling
Authors: Umemoto Eiji , Otani Kazuhiro , Ikeno Takashi , Verjan Garcia Noel , Hayasaka Haruko , Bai Zhongbin , Jang Myoung Ho , Tanaka Toshiyuki , Nagasawa Takashi , Ueda Koichi , Miyasaka Masayuki
Published: May 2012

Although the spleen plays an important role in host defense against infection, the mechanism underlying the migration of the innate immune cells, plasmacytoid dendritic cells (pDCs), into the spleen remains ill defined. In this article, we report that pDCs constitutively migrate into the splenic white pulp (WP) in a manner dependent on the chemokine receptors CCR7 and CXCR4. In CCR7-deficient mice and CCR7 ligand-deficient mice, compared with wild-type (WT) mice, substantially fewer pDCs were found in the periarteriolar lymphoid sheath of the splenic WP under steady-state conditions. In addition, the migration of adoptively transferred CCR7-deficient pDCs into the WP was significantly worse than that of WT pDCs, supporting the idea that pDC trafficking to the splenic WP requires CCR7 signaling. WT pDCs responded to a CCR7 ligand with modest chemotaxis and ICAM-1 binding in vitro, and priming with the CCR7 ligand enabled the pDCs to migrate efficiently toward low concentrations of CXCL12 in a CXCR4-dependent manner, raising the possibility that CCR7 signaling enhances CXCR4-mediated pDC migration. In agreement with this hypothesis, CCL21 and CXCL12 were colocalized on fibroblastic reticular cells in the T cell zone and in the marginal zone bridging channels, through which pDCs appeared to enter the WP. Furthermore, functional blockage of CCR7 and CXCR4 abrogated pDC trafficking into the WP. Collectively, these results strongly suggest that pDCs employ both CCR7 and CXCR4 as critical chemokine receptors to migrate into the WP under steady-state conditions.
Phytoplankton niches estimated from field data
Authors: Irwin Andrew J. , Nelles Andrew M. , Finkel Zoe V.
Published: May 2012

We combine phytoplankton occurrence data for 119 species from the continuous plankton recorder with climatological environmental variables in the North Atlantic to obtain ecological response functions of each species using the MaxEnt statistical method. These response functions describe how the probability of occurrence of each species changes as a function of environmental conditions and can be reduced to a simple description of phytoplankton realized niches using the mean and standard deviation of each environmental variable, weighted by its response function. Although there was substantial variation in the realized niche among species within groups, the envelope of the realized niches of North Atlantic diatoms and dinoflagellates is mostly separate in niche space.
Bacterial uptake of low molecular weight organics in the subtropical Atlantic: Are major phylogenetic groups functionally different?
Authors: Alonso-Sáez Laura , Sánchez Olga , Gasol Josep M.
Published: May 2012

We present measurements of glucose, amino acids, and adenosine triphosphate (ATP) bacterial uptake at tracer concentrations across an oceanic gradient from the Cape Blanc upwelling to the Northeast Atlantic subtropical gyre. The bulk uptake of the compounds increased in the upwelling, with amino acids being the most actively taken up substrate (up to 20 pmol L−1 h−1). The single‐cell activity of the bacterial groups also increased in the upwelling, particularly for Rhodobacteraceae (up to 94% of active cells), but this group had low activity in oligotrophic waters (< 10% of active cells), which suggests it is exclusively adapted to high‐nutrient conditions. The percentage of SAR11 active cells was relatively high in the upwelling area, particularly for glucose and amino acid uptake (up to 53% of active cells), which suggests that some members of this group are also adapted to nutrient‐rich environments. Of the broad phylogenetic groups tested, Bacteroidetes were the least active and Alpha‐ and Gammaproteobacteria showed similar percentages of active cells in amino acid uptake (∼ 30%). Alphaproteobacteria had the highest percent of cells involved in glucose uptake, while Gammaproteobacteria dominated ATP uptake. This general pattern was confirmed in a broader analysis that included data from contrasting marine environments, which suggests that major phylogenetic groups of bacteria participate differently in the turnover of these low‐molecular‐weight organics. Our results support the view that broad phylogenetic groups can be identified within the bacterial ‘black box’ with different patterns in the cycling of organic matter. Analyzing them may help us understand, and ultimately predict, oceanic carbon processing.
Modeling sinking rate of zooplankton carcasses: Effects of stratification and mixing
Authors: Kirillin Georgiy , Grossart Hans-Peter , Tang Kam W.
Published: May 2012

Using the carcass sinking rate and density determined in laboratory for several freshwater zooplankton species, we developed a model of zooplankton carcass sinking as affected by turbulence and stratification. The model was subsequently used to estimate the residence time of zooplankton carcasses in the water column of Lake Stechlin, a typical temperate dimictic lake in northeastern Germany. The residence time varied among the different species and was strongly affected by thermal stratification. At the peak of summer stratification, the carcasses stayed up to 5 d in the 70 m‐deep water column before reaching the lake bottom. Residence time was long enough that zooplankton carcasses could serve as an important matter and energy source for bacteria in the lake's pelagic zone and hence have the potential to significantly affect aquatic carbon and nutrient cycling. The proposed model of sinking rates, based on physically sound relationships, can be easily applied to other passively sinking particles, and be integrated into large ecosystem models.
Internal waves downstream of Norfolk Ridge, western Pacific, and their biophysical implications
Authors: Stevens Craig L. , Sutton Philip J. H. , N Cliff S. Law
Published: May 2012

An 11‐d quasi‐Lagrangian surface layer experiment to the east of Norfolk Island tracked a 140‐m‐deep drifting vertical array (DVA) of instruments, including conductivity sensors, thermistors, and current meters. These are the first in situ data from the area to measure large‐amplitude internal waves. The observations show isotherm peak‐to‐peak excursions reaching 50 m and were dominated by the semidiurnal forcing frequency. The DVA exhibited horizontal loops at the semidiurnal tidal frequency as it tracked water at depths of 80‐140 m to within 10% of total horizontal displacement. The large vertical isotherm excursions generated substantial vertical shear. Temperature microstructure estimates of the vertical diffusivity of scalar properties at 70‐m depth, around the center of the thermocline, were on the order of 10−4 m2 s−1 and around an order of magnitude larger at shallower depths. When combined with nitrate data, this implies vertical fluxes of nitrate in the pycnocline of ∼ 1 mmol m−2 d−1. The internal waves also potentially cause an interaction between the variability in tidal forcing and the diurnal radiation cycle that influences chlorophyll in the deep chlorophyll maximum. The average effect of the internal wave was to increase the light level for a particular isotherm over the static case. The internal wave‐induced velocities were strong enough to dominate phytoplankton rise speeds and so potentially played a role in the formation and persistence of an observed Trichodesmium bloom.
Cyclic Cantilever Bending of Copper Nanowhiskers
Authors: Schopf Carola , Schamel Matthias , Strunk Horst P. , Richter Gunther
Published: May 2012

A cyclic bending test with cantilever geometry is developed for probing local mechanical properties of single crystalline Cu nanowhiskers (NWs). A lower limit for the yield stress for such whiskers is derived at ≈5 GPa. Since all NWs exhibit the axis parallel to the 〈1 1 0〉 crystallographic direction, the resolved shear stress can be calculated. The values of ≈2 GPa lie close to the theoretical strength limit and predict partial dislocation nucleation as the governing mechanism at the onset of plastic deformation. The yield stress is practically independent of the whisker diameter.
Frontonasal dysplasia, callosal agenesis, basal encephalocele, and eye anomalies syndrome with a partial 21q22.3 deletion
Authors: Guion‐Almeida Maria Leine , Richieri‐Costa Antonio , Jehee Fernanda Sarquis , Passos‐Bueno Maria Rita Santos , Zechi‐Ceide Roseli Maria
Published: May 2012

We describe a girl with a phenotype characterized by frontonasal dysplasia, callosal agenesis, basal encephalocele, and eye anomalies who presents a 46,XX,r(21) karyotype. Array‐comparative genomic hybridization using the Afflymetrix 100K DNA oligoarray set showed an interstitial deletion 21q22.3 of approximately 219 kb. Conventional karyotype of both parents was normal, and it was not possible to perform the molecular studies. In this report we raise the hypothesis that the deleted genes located at 21q22.3 could account to the phenotype. © 2012 Wiley Periodicals, Inc.
Attitudes toward prenatal genetic testing for Treacher Collins syndrome among affected individuals and families
Authors: Wu Rebecca L. , Lawson Cathleen S. , Jabs Ethylin Wang , Sanderson Saskia C.
Published: May 2012

Treacher Collins syndrome (TCS) is a craniofacial syndrome that is both phenotypically variable and heterogeneous, caused by mutations in the TCOF1, POLR1C, and POLR1D genes. We examined attitudes towards TCS prenatal genetic testing among affected families using a telephone questionnaire. Participants were 31 affected adults and relatives recruited primarily through families cared for in the mid‐Atlantic region. Nineteen participants (65%) reported that they would take a TCS prenatal genetic test which could not predict degree of disease severity. Interest in TCS genetic testing was associated with higher income, higher concern about having a child with TCS, lower religiosity, lower concern about genetic testing procedures, and having a sporadic rather than familial mutation. Over half reported that their decision to have TCS genetic testing would be influenced a great deal by their desire to relieve anxiety and attitudes toward abortion. Ten participants (32%) reported that they would be likely to end the pregnancy upon receiving a positive test result; this was lower amongst TCS affected individuals and higher amongst participants with children with TCS. Genetics healthcare providers need to be aware of affected individuals' and families' attitudes and interest in prenatal genetic testing for TCS, and the possible implications for other craniofacial disorders, so that patients' information needs can be met. © 2012 Wiley Periodicals, Inc.
Effect of crosslinker and nanoclay on jute fabric reinforced soy flour green composite
Authors: Iman Murshid , Maji Tarun K.
Published: May 2012

Bio‐based composites were prepared by using soy flour, jute, glutaraldehyde (GA), nanoclay, and glycerol. An optimum concentration of glycerol was used as a plasticizer. The synthesized composites were characterized by various techniques such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), X‐ray diffractometry (XRD), Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). The exfoliation of clay layers was detected both by XRD and TEM study. FTIR study showed an interaction between clay, jute, and soy flour. The percentage content of GA and nanoclay was found to have profound influence on various physical properties of the composites. The increase in the concentration of GA and nanoclay improved the thermal stability, flame retardancy, dimensional stability, and most importantly the mechanical properties of the prepared composite. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Chemometric study of graft copolymerization of guar‐g‐(acrylamide‐co‐diallyl dimethylammonium chloride)
Authors: Agarwal Vipul , McLean Douglas , Horne James , Richardson Desmond , Stack Karen
Published: May 2012

Chemometrics was employed to study the effect of various reaction conditions on the graft copolymerization of acrylamide (AM) and diallyl dimethylammonium chloride (DADMAC) onto guar gum using the cerous sulfate and potassium persulfate complex initiation system. A two level full factorial design was used to study the effect of reaction parameters on percentage grafting (%G) and monomer conversion (%MC). Synthesized polymers were characterized using Fourier transform infrared spectroscopy (FTIR), 1H‐NMR (nuclear magnetic resonance spectroscopy), and 13C‐NMR and also were analyzed for differences in intrinsic viscosity and charge incurred with changing reaction conditions. The concentration of AM was observed to have the greater effect on %grafting. Interaction effects between the reaction temperature and concentration of AM were also found to be important. Under the reaction condition studied, the highest grafting (%G) was obtained for polymer 1 (0.7M AM concentration, 60°C reaction temperature, and 1M acid concentration). © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Thermomechanical properties and morphology of polyethylene oxide and phenolic resole blends
Authors: Ratna Debdatta , Karger Kocsis J.
Published: May 2012

Blends of poly(ethylene oxide) (PEO) and resole type phenolic resin were prepared by a solution cast method using water as a solvent. The cured blends were made by heat curing without using any catalyst. The blends were characterized by dynamic mechanical analysis (DMA), which indicated that PEO forms compatible blend with the resole. The glass transition values, read from the DMA traces, showed a positive shift as compared to the theoretical values calculated by the Fox equation. This suggests a strong H‐bonding interaction between the phenolic resole and PEO as established by Fourier transformed infrared spectroscopy. Flexural test indicated an enhanced flexibility of the blends when compared to the neat phenolic resin. The fracture surface analysis by using a scanning electron microscope (SEM) revealed an increase in plastic deformation with increasing PEO concentration in the blend. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Inflammatory markers in coronary artery disease
Authors: Ikonomidis Ignatios , Michalakeas Christos A. , Parissis John , Paraskevaidis Ioannis , Ntai Konstantina , Papadakis Ioannis , Anastasiou‐Nana Maria , Lekakis John
Published: May 2012

Coronary artery disease (CAD) is one of the most common manifestations of atherosclerosis. Inflammation is considered one of the major processes that contribute to atherogenesis. Inflammation plays an important role not only on the initiation and progression of atherosclerosis but also on plaque rupture, an event that leads to acute vascular events. Various biomarkers express different pathways and pathophysiologic mechanisms of cardiovascular disease, and inflammatory biomarkers express different parts of the atherogenic process, regarding the initiation and progression of atherosclerosis or the destabilization of the atherosclerotic plaque. Therefore, inflammatory biomarkers may prove to be useful in the detection, staging, and prognosis of patients with CAD. Furthermore, the fact that inflammatory processes are essential steps in the course of the disease offers future therapeutic targets for the interruption of the atherogenic process or for the management of acute events.
Rapamycin treatment inhibits CHO cell death in a serum‐free suspension culture by autophagy induction
Authors: Lee Jae Seong , Lee Gyun Min
Published: May 2012

Rapamycin, a specific mTOR inhibitor, has been used as a chemical activator in autophagy research both in vitro and in vivo. Recently, autophagy has received attention as an anti‐cell death engineering target in addition to apoptosis in the Chinese hamster ovary (CHO) cell engineering field. Here, the effect of rapamycin and the subsequent autophagy induction is investigated on two CHO cell lines, DG44 host and an antibody‐producing recombinant CHO (rCHO), in a serum‐free suspension culture. In both cell lines, the rapamycin treatment delayed the viability drop and apoptosis induction. In particular, the improved cell viability of the antibody‐producing rCHO cell line resulting from the rapamycin treatment led to a 21% increase in the maximum antibody concentration. From observations that a rapamycin derivative, everolimus, demonstrated similar positive effects in both cell lines, but not FK‐506, which forms the same complex as rapamycin, but does not inhibit mTOR, it was demonstrated that the positive effects of rapamycin appear to be mTOR‐dependent. In addition, the cultivation with rapamycin and/or an autophagy inhibitor, bafilomycin A1, indicated that the autophagy induction is related to the positive effects of rapamycin. The genetic perturbation of the autophagy pathway through the regulation of the expression level of Beclin‐1, an important autophagy regulator, resulted in a delayed autophagy induction and apoptosis inhibition in response to the rapamycin treatment in the DG44 host cell line. Taken together, the results obtained in this study imply a positive role for autophagy and predict the usefulness of pro‐autophagy engineering in CHO cell cultures. Biotechnol. Bioeng. 2012; 109: 3093–3102. © 2012 Wiley Periodicals, Inc.
Risk of bleeding associated with use of systemic thromboembolic prophylaxis during laparoscopic cholecystectomy
Authors: Persson G , Strömberg J , Svennblad B , Sandblom G
Published: May 2012

Background: The extent to which systemic perioperative thromboembolic prophylaxis affects peroperative and postoperative bleeding during cholecystectomy is not known. This article reports on risk of bleeding in a national cohort of cholecystectomies.

Methods: All cholecystectomies registered in the Swedish Register of Gallstone Surgery and Endoscopic Retrograde Cholangiopancreatography (GallRiks) between 2005 and 2010 were reviewed. Peroperative bleeding was defined as bleeding that could not be controlled by standard surgical techniques, necessitated conversion to an open procedure or required peroperative blood transfusion. Postoperative bleeding was defined as bleeding that necessitated reoperation, transfusion or a prolonged hospital stay. Risk estimates were performed using univariable and multiple logistic regression, and reported as odds ratios (ORs).

Results: A total of 51 621 procedures were registered in GallRiks. Some 48 010 patients were included in the analyses, of whom 21 259 (44·3 per cent) received thromboembolic prophylaxis. Peroperative bleeding complications occurred in 400 (1·9 per cent) and postoperative bleeding in 296 (1·4 per cent) given thromboembolic prophylaxis, compared with 189 (0·7 per cent) and 195 (0·7 per cent) respectively without thromboprophylaxis. After adjusting for age, sex, indication for surgery, American Society of Anesthesiologists grade, mode of admission, operative approach, duration of surgery and hospital volume, the OR for peroperative or postoperative bleeding complications in the group receiving prophylaxis was 1·35 (95 per cent confidence interval 1·17 to 1·55). However, in a subgroup analysis the risk was increased in laparoscopic surgery only. At 30-day follow-up, a total of 74 patients (0·2 per cent) had developed postoperative thromboembolism, 43 (0·2 per cent) of those who received thromboembolic prophylaxis compared with 31 (0·1 per cent) of those who did not.

Conclusion: Thromboprophylaxis in patients undergoing laparoscopic cholecystectomy increased the risk of bleeding, but the occurrence of thromboembolic events was not significantly reduced. Identification of high- and low-risk patients is needed to guide clinical decisions regarding medical thromboprophylaxis.
Design, Synthesis, and Biological Evaluation of 2‐Aminobenzanilide Derivatives as Potent and Selective HDAC Inhibitors
Authors: Stolfa Diana A. , Stefanachi Angela , Gajer Julia M. , Nebbioso Angela , Altucci Lucia , Cellamare Saverio , Jung Manfred , Carotti Angelo
Published: May 2012

Epigenetic regulation is an essential process for the normal functioning of genes. Therefore, targeting epigenetic dysregulation in cancer may be a valid therapeutic approach for the treatment of this severe disease. Histone deacetylases (HDACs) are enzymes involved in the regulation of epigenetic post‐translational modifications; because they are overexpressed in many types of cancer, HDACs are valuable targets for the development of new anticancer agents. A large series of 2‐aminobenzanilides linked at the 4′‐position to α‐amino acid amides, arenes, and heteroarenes through a methylene bridge were designed, synthesized, and tested as novel HDAC inhibitors. Several compounds showed IC50 values in the two‐digit nanomolar range in hrHDAC1 inhibition assays, lower than that of the reference compound MS‐275. They also showed interesting selectivity profiles, as confirmed by western blot assays.
Neuroimmune mechanisms in fetal alcohol spectrum disorder
Authors: Kane Cynthia J.M. , Phelan Kevin D. , Drew Paul D.
Published: May 2012

Fetal alcohol spectrum disorder (FASD) is a major health concern worldwide and results from maternal consumption of alcohol during pregnancy. It produces tremendous individual, social, and economic losses. This review will first summarize the structural, functional, and behavior changes seen in FASD. The development of the neuroimmune system will be then be described with particular emphasis on the role of microglial cells in the normal regulation of homeostatic function in the central nervous system (CNS) including synaptic transmission. The impact of alcohol on the neuroimmune system in the developing CNS will be discussed in the context of several key immune molecules and signaling pathways involved in neuroimmune mechanisms that contribute to FASD. This review concludes with a summary of the development of early therapeutic approaches utilizing immunosuppressive drugs to target alcohol‐induced pathologies. The significant role played by neuroimmune mechanisms in alcohol addiction and pathology provides a focus for future research aimed at understanding and treating the consequences of FASD. © 2012 Wiley Periodicals, Inc. Develop Neurobiol, 2012
Integrating species distribution models (SDMs) and phylogeography for two species of Alpine Primula
Authors: Schorr G. , Holstein N. , Pearman P. B. , Guisan A. , Kadereit J. W.
Published: May 2012

The major intention of the present study was to investigate whether an approach combining the use of niche‐based palaeodistribution modeling and phylo‐geography would support or modify hypotheses about the Quaternary distributional history derived from phylogeographic methods alone. Our study system comprised two closely related species of Alpine Primula. We used species distribution models based on the extant distribution of the species and last glacial maximum (LGM) climate models to predict the distribution of the two species during the LGM. Phylogeographic data were generated using amplified fragment length polymorphisms (AFLPs). In Primula hirsuta, models of past distribution and phylogeographic data are partly congruent and support the hypothesis of widespread nunatak survival in the Central Alps. Species distribution models (SDMs) allowed us to differentiate between alpine regions that harbor potential nunatak areas and regions that have been colonized from other areas. SDMs revealed that diversity is a good indicator for nunataks, while rarity is a good indicator for peripheral relict populations that were not source for the recolonization of the inner Alps. In P. daonensis, palaeo‐distribution models and phylogeographic data are incongruent. Besides the uncertainty inherent to this type of modeling approach (e.g., relatively coarse 1‐km grain size), disagreement of models and data may partly be caused by shifts of ecological niche in both species. Nevertheless, we demonstrate that the combination of palaeo‐distribution modeling with phylogeographical approaches provides a more differentiated picture of the distributional history of species and partly supports (P. hirsuta) and partly modifies (P. daonensis and P. hirsuta) hypotheses of Quaternary distributional history. Some of the refugial area indicated by palaeodistribution models could not have been identified with phylogeographic data.
SURROGATE, FRIEND OR FOE? THE NEED FOR CASE STUDIES OF THE USE OF SURROGATE OUTCOMES IN COST‐EFFECTIVENESS ANALYSES
Authors: Ciani O. , Taylor R. S.
Published: May 2012

We comment on a recent article by Hawkins et al. presenting different analytic approaches for the inclusion of surrogate and final outcomes in cost‐effectiveness analyses. This methodological case study provides a timely and valuable contribution to build on the debate about the use of evidence based on surrogate outcomes in health technology assessment. Copyright © 2012 John Wiley & Sons, Ltd.
Characterization and cell behavior of titanium surfaces with PLL/DNA modification via a layer‐by‐layer technique
Authors: Gao Wenli , Feng Bo , Lu Xiong , Wang Jianxin , Qu Shuxin , Weng Jie
Published: May 2012

This study describes the fabrication of two types of multilayered films onto titanium by layer‐by‐layer (LBL) self‐assembly, using poly‐L‐lysine (PLL) as the cationic polyelectrolyte and deoxyribonucleic acid (DNA) as the anionic polyelectrolyte. The assembling process of each component was studied using atomic force microscopy (AFM) and quartz crystal balance (QCM). Zeta potential of the LBL‐coated microparticles was measured by dynamic light scattering. Titanium substrates with or without multilayered films were used in osteoblast cell culture experiments to study cell proliferation, viability, differentiation, and morphology. Results of AFM and QCM indicated the progressive build‐up of the multilayered coatings. The surface morphology of three types of multilayered films showed elevations in the nanoscale range. The data of zeta potential showed that the surface terminated with PLL displayed positive charge while the surface terminated with DNA displayed negative charge. The proliferation of osteoblasts on modified titanium films was found to be greater than that on control (p < 0.05) after 3 and 7 days culture, respectively. Alamar blue measurement showed that the PLL/DNA‐modified films have higher cell viability (p < 0.05) than the control. Still, the alkaline phosphatase activity assay revealed a better differentiated phenotype on three types of multilayered surfaces compared to noncoated controls. Collectively our results suggest that PLL/DNA were successfully used to surface engineer titanium via LBL technique, and enhanced its cell biocompatibility. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2012.
Comparison of decellularization techniques for preparation of extracellular matrix scaffolds derived from three‐dimensional cell culture
Authors: Lu Hongxu , Hoshiba Takashi , Kawazoe Naoki , Chen Guoping
Published: May 2012

Extracellular matrix (ECM) scaffolds derived from cultured cells have drawn increasing attention for use in tissue engineering. We have developed a method to prepare cultured cell‐derived ECM scaffolds by combining three‐dimensional cell culture, decellularization, and selective template removal. Cell‐ECM‐template complexes were first formed by culture of cells in a poly(lactic‐co‐glycolic acid) (PLGA) mesh template to deposit their own ECM. The complexes were subsequently decellularized to remove cellular components. Finally, the PLGA template was selectively removed to obtain the ECM scaffolds. Seven decellularization methods were compared for their decellularization effects during scaffold preparation. They were: freeze‐thaw cycling (–80°C, six times) with ammonia water (25 mM); 0.1% Triton™ X‐100 (TX100) with 1.5MKCl aqueous solution; freeze‐thaw cycling alone; ammonia water alone; TX100 extraction; osmotic shock with 1.5MKCl; and freeze‐thaw cycling with 3MNaCl. Among these methods, the methods of freeze‐thaw cycling with NH4OH and TX100 with 1.5MKCl showed the best effect on the removal of cellular components from the complexes, while the other five methods could only partially remove cellular components. The ECM scaffolds prepared by these two methods had similar gross appearances and microstructures.In vivoimplantation of the ECM scaffolds prepared by these two methods induced mild host responses. The two decellularization methods were demonstrated to be effective for preparation of cultured cell‐derived ECM scaffolds. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 100A: 2507–2516, 2012.
Bony integration of titanium implants with a novel bioactive calcium titanate (Ca4Ti3O10) surface treatment in a rabbit model
Authors: Haenle Maximilian , Lindner Tobias , Ellenrieder Martin , Willfahrt Manfred , Schell Hanna , Mittelmeier Wolfram , Bader Rainer
Published: May 2012

Nowadays total joint replacement is an indispensable component of modern medicine. The surfaces characteristics of cementless prostheses may be altered to achieve an accelerated and enduring bony integration. Classic surface coatings bear the risk of loosening or flaking from the implant body. This risk is excluded by the chemical conversion of the naturally existing TiO2 surface layer into calcium titanate. The aim of this experimental animal study was to investigate the bony integration of implants with a new calcium titanate surface (Ca4Ti3O10) compared with a conventional standard Ti6Al4V surface. Cylindrical implants, made of titanium alloy (Ti6Al4V) were implanted in both lateral femoral condyles of New Zealand white rabbits. In each animal, an implant with and without surface treatment was inserted in a blinded manner. Animals were sacrificed after 4, 12, and 36 weeks, respectively. The axial pull‐off forces were determined for 25 animals using a universal testing machine (Zwick Z010, Ulm, Germany). Furthermore, a histological analysis of the bony integration of the implants was performed in 12 specimens. In general, the pull‐off forces for untreated and treated implants increased with longer survival times of the rabbits. No significant difference could be shown after 4 weeks between treated and untreated implants. After 12 weeks, the treated implants revealed a statistical significant higher pull‐off force. After 36 weeks, the pull‐off forces for treated and untreated implants aligned again. Titanium implants treated with calcium titanate, may offer an interesting and promising implant surface modification for endoprosthetic implants. They might lead to an accelerated osseointegration of total hip and knee replacements. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A 100A:2710–2716, 2012.
A novel wet extrusion technique to fabricate self‐assembled microfiber scaffolds for controlled drug delivery
Authors: Lavin Danya M. , Harrison Michael W. , Tee Louis Y. , Wei Karen A. , Mathiowitz Edith
Published: May 2012

We have developed a novel wet extrusion process to fabricate nonwoven self‐assembled microfiber scaffolds with uniform diameters less than 5 μm and without any postmanipulation. In this method, a poly(L‐lactic acid) solution flows dropwise into a stirring nonsolvent bath, deforming into liquid polymer streams that self‐assemble into a nonwoven microfiber scaffold. The ability to tune fiber diameter was achieved by decreasing polymer spin dope concentration and increasing the silicon oil to petroleum ether ratio of the nonsolvent spin bath. To demonstrate the drug delivery capabilities of scaffolds, heparin was encapsulated using a conventional water‐in‐oil (W/O) emulsion technique and a cryogenic emulsion technique developed in our laboratory. Spin dope preparation was found to significantly effect the release kinetics of self‐assembled scaffolds by altering the interconnectivity of pores within the precipitating filaments. After 35 days, scaffolds prepared from W/O emulsions released up to 45% encapsulated heparin, whereas nearly 80% release of heparin was observed from cryogenic emulsion formulations. The versatility of our system, combined with the prolonged release of small molecules and the ability to control the homogeneity of self‐assembling scaffolds, could be beneficial for many tissue regeneration and engineering applications. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A 100A: 2793–2802, 2012.
Mycobacterium smegmatis genomic characteristics associated with its saprophyte lifestyle
Authors: Long Quanxin , Zhou Qi , Ji Lei , Wu Jun , Wang Wen , Xie Jianping
Published: May 2012

Tuberculosis (TB) remains a great threat to global public health. The high biosafety level III required to tackle its causative agent Mycobacterium tuberculosis seriously hinders the exploration of its biology and new countermeasures. M. smegmatis is a widely recognized good surrogate of M. tuberculosis, largely due to their conserved transcriptional machinery, sigma factors, and two‐component systems. However, their distinct lifestyles often confound the explanation of the results. M. tuberculosis leads both parasitic and free life, while M. smegmatis is largely saprophyte. To make full advantage of this model, it is helpful to discover the genome features associated with M. smegmatis unique niches, such as its saprophytic life, high salt tolerance, and relative short generation time. We employed the gene ontology enrichment analysis to characterize the unique lifestyle of M. smegmatis. Gene ontology enrichment analysis provided 12 terms; most are relevant to the special lifestyle of M. smegmatis, especially the saprophytic niche, high salt tolerance adaptation, and short generation time. In‐depth functional characterization of these genes will shed new lights on the genetic basis of M. smegmatis saprophytic life and hasten the understanding of the unique biology of M. tuberculosis. J. Cell. Biochem. 113: 3051–3055, 2012. © 2012 Wiley Periodicals, Inc.