Search

The synaptic vesicle glycoprotein 2A (SV2A), a protein essential to the proper nervous system function, is found in presynaptic vesicles. Thus, SV2A targeting, using dedicated radiotracers combined with positron emission tomography (PET), allows the assessment of synaptic density in the living brain. The first-in-class fluorinated SV2A specific radioligand, [18F]UCB-H, is now available at high activity through an efficient radiosynthesis compliant with current good manufacturing practices (cGMP). We report here a noninvasive method to quantify [18F]UCB-H binding in rat brain with microPET. Validation study in rats confirmed the need of high enantiomeric purity to target SV2A in vivo. We demonstrated the reliability of a population-based input function to quantify SV2A in preclinical microPET setting. Finally, we investigated the in vivo metabolism of [18F]UCB-H and confirmed the negligible amount of radiometabolites in the rat brain. Hence, the in vivo quantification of SV2A using [18F]UCB-H microPET seems a promising tool for the assessment of the synaptic density in the rat brain, and opens the way for longitudinal follow-up in neurodegenerative disease rodent models.

Expression of the chemokine receptor Ccr6 is shared by most IL-22–producing cells, and Ccr6-deficient mice showed decreased IL-22 production and skin inflammation upon IL-23 intradermal injections. To determine whether this observation might be extended to another psoriasis model, we applied imiquimod on Ccr6-deficient mice. Although epidermal IL-22 production was decreased because of a deficient recruitment of γδ T cells in these mice, they were not protected against psoriatic lesions. When primary epidermis or dermis tissue culture cells from nontreated mice were stimulated ex vivo with IL-1α/IL-2/IL-23, we observed that Ccr6 is crucial for Il22expression from epidermal but not dermal cultures. Taking advantage of Ccr6-LacZ–knock-in mice, we showed that Ccr6 is necessary for the homing of Ccr6-positive cells, probably a γδ T-cell subset, which represents the main potential IL-22 source in the epidermis. Similar results were observed in Rag1–/–epidermis and dermis primary cultures, in which a subset of innate lymphoid cells expressing Ccr6 represents the main potential source of IL-22. Taken together, our data show that Ccr6 is not required for the development of skin lesions induced by imiquimod despite its effect on epidermal homing of IL-22–producing cells.

As nurses in hospitals are confronted with increasing numbers of older patients, their geriatric nursing skills and knowledge must be integrated into daily clinical practice. Early risk identification via screening tools may help improve geriatric care. To reduce the assessment burden of nurses, the Maastricht Frailty Screening Tool for Hospitalized Patients (MFST-HP) was developed. The aim of the current study was to explore aspects of reliability, validity, and feasibility of the MFST-HP. Intrarater reliability was assessed by measuring patients two times within 24 hours. Interrater reliability was assessed by having patients screened by two different nurses. Construct validity was studied by the associations between the MFST-HP scores and age and comorbidities. Intraclass correlation coefficients for both intra- and interrater reliability were good (>0.93). Older patients and those with more comorbidity showed higher scores on the MFST-HP compared to younger patients and those with less comorbidity. The MFST-HP shows promise as a reliable, valid, and feasible screening tool for frailty among hospitalized older adults. As nurses in hospitals are confronted with increasing numbers of older patients, their geriatric nursing skills and knowledge must be integrated into daily clinical practice. Early risk identification via screening tools may help improve geriatric care. To reduce the assessment burden of nurses, the Maastricht Frailty Screening Tool for Hospitalized Patients (MFST-HP) was developed. The aim of the current study was to explore aspects of reliability, validity, and feasibility of the MFST-HP. Intrarater reliability was assessed by measuring patients two times within 24 hours. Interrater reliability was assessed by having patients screened by two different nurses. Construct validity was studied by the associations between the MFST-HP scores and age and comorbidities. Intraclass correlation coefficients for both intra- and interrater reliability were good (>0.93). Older patients and those with more comorbidity showed higher scores on the MFST-HP compared to younger patients and those with less comorbidity. The MFST-HP shows promise as a reliable, valid, and feasible screening tool for frailty among hospitalized older adults. [Res Gerontol Nurs. 2016; 9(5):243–251.]

Power grid outages cause huge economical and societal costs. Disruptions in the power distribution grid are responsible for a significant fraction of electric power unavailability to customers. The impact of extreme weather conditions, continuously increasing demand, and the over-ageing of assets in the grid, deteriorates the safety of electric power delivery. Measures to analyse the robustness characteristics and to identify vulnerabilities of power grids are of utmost importance. This paper proposes a metric to quantitatively assess the robustness of power distribution grids from a topological point of view. Real-world data is used to demonstrate the applicability of the proposed metric as a tool to assess the criticality of assets in a distribution grid.

Tree topologies are often deployed in large-scale distributed systems to structure a hierarchical communication. Building and maintaining overlay networks self-organized in tree topologies is challenging to achieve in dynamic environments. Performance trade-offs between resilience to failures and message overhead need to be considered. This paper introduces eight adaptation strategies that provide a higher abstraction, modularity and reconfigurability in the tree self-organization process. Performance can be further enhanced by dynamically changing strategies during system runtime. Experimental evaluation illustrates the performance trade-offs and properties of adaptation strategies.

The vernacular public autopsy practised in the western highlands of Cameroon consists of splitting open the belly and chest of a dead person and examining their contents. It is done in the presence of senior members of the village or kin of the deceased. It is based on the assumption that the skin of any subject is an envelope, with apertures through which all kinds of substances may flow on their way out of the body or into it. It is believed that the internal organs and substances are impacted by such flows, have an efficacy of their own and impact in turn on other subjects. Consequently, autopsy may be considered as a technique that has efficacy on the body of the dead as well as on his/her neighbours and relatives.

The charging of electric vehicles forms a new market, which is emerging partially from existing energy markets. A new market requires a new market model; a description of roles, responsibilities and processes. Designing a market model for a yet non-existent market is complex and abstract, since future market dynamics are difficult to predict. Simulation games are a proven method to deal with such complexities but have rarely been applied on new market model designs. The novel E-CITY 2020 simulation game has been developed to examine the contribution of gaming simulation to the Dutch market model design. The game resulted in increased and shared understanding of the future market model for both designers and participants. Second, it identified requirements for successful implementation of the market model. The results lead us to conclude that simulation games are an effective tool to overcome complexities in future market model development.

Fractional exhaled nitric oxide (FENO) measurements are useful in monitoring airway inflammation. Online and offline sampling techniques are well standardized. However, young children are often unable to perform slow vital capacity maneuvers. The aim of this study was to compare a simplified mobile offline tidal breathing method with an online single breath measurement. We performed online and offline FENOmeasurements in children between 5 and 16 years with respiratory disease. Online measurements were performed by a slow vital capacity maneuver; offline measurements were performed by collecting exhaled air in Mylar balloons during tidal breathing. In 59 children (5.3–16.7 years) able to perform both techniques, a good correlation (0.9348) between offline tidal breathing and online single breath measurement was found over a wide range of values. Offline tidal breathing values correspond to online values. Online single breath FENOvalues can be predicted from offline tidal breathing FENOvalues. Offline tidal breathing measurements are highly correlated with online single breath values in children.

Agent mobility is the ability of an agent to migrate from one location to another across a network. Though conceptually relatively straightforward, in practice security of mobile agents is a challenge: from transport layer security to preservation of integrity in open environments. This paper discusses the security issues involved and proposes protocols for secure agent migration. AgentScape, an agent platform for mobile agents, is used to illustrate the feasibility of the implementation of these protocols.

A hydrodynamic characterization of an industrially used gas‐liquid contacting microchannel device is discussed, viz. the micro bubble column of IMM. Furthermore, similar characterization of a gas‐liquid flow microchip of TU/e, with two tailored mixer designs, is used to solve fundamental issues on hydrodynamics, and therefore, to achieve further design and operating optimization of that chip and the IMM device. Flow pattern maps are presented in a dimensionless fashion for further predictions on new fluidic systems for optimum single‐channel multiphase operation. Bubble formation was investigated in the two types of mixers and pinch‐off and hydrodynamic decay mechanisms are observed. The impact of these mechanisms on bubble size, bubble size distributions, and on the corresponding flow patterns, i.e., the type of mixer design, can be decisive for the flow pattern map and thus, may be used to alter flow pattern maps. The bubble sizes and their distribution were improved for the tailored designs, i.e., smaller and more regular bubbles were generated. Finally, the impact of multi‐channel distribution for gas and liquid flow is demonstrated. Intermediate flow patterns such as slug‐annular flow, also found for single‐phase operation, and the simultaneous coexistence of flow regimes are presented, with the latter providing evidence of flow maldistribution.

Abstract: Timing channels constitute one form of covert channels through which programs may be leaking information about the confidential data they manipulate. Such timing channels are typically eliminated by design, employing ad-hoc techniques to avoid information leaks through execution time, or by program transformation techniques, that transform programs that satisfy some form of noninterference property into programs that are time-sensitive termination-sensitive non-interfering. However, existing program transformations are thus far confined to simple languages without objects nor exceptions. We introduce a program transformation that uses transaction mechanisms to prevent timing leaks in sequential object-oriented programs. Under some strong but reasonable hypotheses, the transformation preserves the semantics of programs and yields for every termination-sensitive noninterfering program a time-sensitive termination-sensitive non-interfering program. [Copyright &y& Elsevier]

The surgical management of juxtarenal aneurysms necessitates suprarenal aortic clamping and control of the renal arteries. We attempted to reproduce this procedure laparoscopically. Five female piglets were submitted to a totally laparoscopic approach of the aortoiliac segment. After laparoscopic control of the renal arteries and suprarenal clamping, a 6-mm Dacron tube graft was anastomosed to the juxtarenal aorta. After the procedure, a midline laparotomy allowed verification of the patency of the renal arteries and the quality of the anastomosis. Mean operative time was 198 minutes (range, 170–240 minutes). The dissection took an average of 92 minutes (range, 75–110 minutes). The mean suprarenal aortic cross-clamp time was 46.3 minutes (range, 29.1–81.5 minutes), and the mean anastomotic time was 28.9 minutes (range, 16.5–68.1 minutes). This study demonstrates in this animal model the feasibility of juxtarenal aortic anastomosis using a laparoscopic technique. Newly designed instruments should allow a shorter clamping time in the future.

An efficient gene transfer can be achieved in mouse liver by a rapid tail vein injection of a large volume of plasmid DNA solution (hydrodynamics-based transfection). The mechanism of gene transfer by this procedure is not known. It must be related to the uptake and intracellular fate of DNA. We have investigated the problem by following the uptake by mouse liver and the intracellular distribution of DNA after a rapid tail vein injection of a large (2.0 ml) or a small (0.2 ml) volume of ³⁵S-DNA solution. Total and acid-soluble radioactivity were measured in liver homogenates at increasing times after injection, and their subcellular distributions were established by centrifugation methods and compared with the distributions of marker enzymes of the membrane compartments involved in endocytosis: alkaline phosphodiesterase (plasma membrane) and cathepsin C (lysosomes). ³⁵S-DNA uptake by the liver is similar when a small or a large volume of injection is used but its degradation is markedly slower after a 2.0 ml injection. When a small volume of injection is given, distribution of radioactivity after differential centrifugation indicates that the plasmid DNA is endocytosed and reaches lysosomes where it is hydrolysed. After a large volume injection, part of ³⁵S-DNA has the same fate, another part remains acid-precipitable for at least 1 h and is associated with structures sedimenting at low centrifugation speed in the nuclear fraction N. Analysis of that fraction by gradient centrifugation suggests that these structures are plasma membrane fragments that could originate from the apical domain of hepatocytes. The proportion of ³⁵S-DNA associated with hepatocytes is about doubled after a large volume injection. Fractionation of isolated hepatocytes by centrifugation confirms results obtained on the whole liver. Treatment of the N fraction or isolated hepatocytes with pancreatic DNAse illustrates that ³⁵S-DNA that remains bound to plasma membrane after a large volume injection is located on the outer face. The fact that after an hydrodynamic injection ³⁵S-DNA remains bound to the outside face of the plasma membrane for at least 1 h indicates that it is not, or very slowly, internalised during that period. The relatively small difference in the amount of DNA picked up by hepatocytes depending on the type of injection could not explain the absence of expression after a conventional injection and the strong expression after a hydrodynamic injection. If DNA enters the cells by endocytosis, even after an hydrodynamic injection, its persistence at the outside face of the plasma membrane could favour transfection by allowing hepatocytes to dispose for a relatively long time of a reservoir of intact DNA. Copyright © 2002 John Wiley & Sons, Ltd.

Interleukin 17 (IL-17) is a proinflammatory cytokine produced by activated CD4+ memory T cells. We previously showed that IL-17 increased the growth rate of human cervical tumors transplanted into athymic nude mice. To address the possible role of T cells in the biologic activity of IL-17 for tumor control, we grafted 2 murine hematopoietic immunogenic tumors (P815 and J558L) transfected with a complementary DNA encoding murine IL-17 into syngeneic immunocompetent mice. We found that growth of the 2 IL-17–producing tumors was significantly inhibited compared with that of mock-transfected tumors. In contrast to the antitumor activity of IL-17 observed in immunocompetent mice, we observed no difference in the in vivo growth of IL-17–transfected or mock-transfected P815 cells (P815–IL-17 and P815-Neo, respectively) transplanted into nude mice. We then showed that IL-17 increased generation of specific cytolytic T lymphocytes (CTLs) directed against the immunodominant antigens from P815 called A, B, C, D, and E, since all mice injected with P815–IL-17 developed a P815-specific CTL response, whereas only 6 of 16 mice immunized with P815-Neo had a specific CTL response against the antigens. The induction of CTLs was associated with establishment of a tumor-protective immunity. These experiments suggest that T lymphocytes are involved in the antitumor activity of IL-17. Therefore, IL-17, like other cytokines, appears to be a pleiotropic cytokine with possible protumor or antitumor effects on tumor development, which often depends on the immunogenicity of tumor models.

By stimulating human CD8+ T lymphocytes with autologous dendritic cells infected with an adenovirus encoding MAGE-3, we obtained a cytotoxic T lymphocyte (CTL) clone that recognized a new MAGE-3 antigenic peptide, AELVHFLLL, which is presented by HLA-B40. This peptide is also encoded by MAGE-12. The CTL clone recognized MAGE-3–expressing tumor cells only when they were first treated with IFN-γ. Since this treatment is known to induce the exchange of the three catalytic subunits of the proteasome to form the immunoproteasome, this result suggested that the processing of this MAGE-3 peptide required the immunoproteasome. Transfection experiments showed that the substitution of β5i (LMP7) for β5 is necessary and sufficient for producing the peptide, whereas a mutated form of β5i (LMP7) lacking the catalytically active site was ineffective. Mass spectrometric analyses of in vitro digestions of a long precursor peptide with either proteasome type showed that the immunoproteasome produced the antigenic peptide more efficiently, whereas the standard proteasome more efficiently introduced cleavages destroying the antigenic peptide. This is the first example of a tumor-specific antigen exclusively presented by tumor cells expressing the immunoproteasome.

Background:The metered-dose inhalers are the most commonly used devices in the treatment of asthma, but dry powder inhalers (eg, Turbohaler) are being increasingly used. Studies evaluating how well children can use a Turbohaler are lacking. Objective:We assessed whether the correct use of a Turbohaler could be easily taught to unselected stable asthmatic children. Methods:One hundred sixty-one asthmatic children aged 5 to 17 years (mean, 9.8 years) consecutively attending the outpatient clinic were included in study. After a demonstration and 10 minutes of training, the inhalation technique was checked in a standardized way (yes/no response). Keeping the device upright, proper preparation of the drug dose and inspiratory flow on inhalation were measured by the Turbohaler trainer. Results:One hundred thirty-three children (83%) performed every step correctly (ie, 96% of children older than 8 years but only 55% of children between 5 and 8 years; P< .001). Of 28 children incorrectly using the Turbuhaler-trainer, 20 generated insufficient inspiratory flow through the device. There was no significant difference in airway obstruction (expressed as percent of predicted forced vital capacity, FEV1, and Tiffeneau index) between correct and incorrect users, but when measured through the pneumotachograph, mean peak inspiratory flow (expressed as percent predicted) was significantly lower in those children incorrectly using the device. Turbohaler use was reevaluated after 4.7 ± 2.0 months in a subset of 64 patients. Fifty-three of 64 (83%) children again used the device correctly. Only 3 of 13 who used the device incorrectly at the first evaluation used it correctly at the second evaluation. Conclusions:We conclude that the correct use of the Turbohaler can be easily taught to asthmatic children older than 8 years. Those who use the device correctly after initial instructions continue to do so afterwards. (J Allergy Clin Immunol 1999;103:763-7.)

The activity of interleukin (IL)-9 on B cells was analyzed in vivo using transgenic mice that constitutively express this cytokine. These mice show an increase in both baseline and antigen-specific immunoglobulin concentrations for all isotypes tested. Analysis of B cell populations showed a specific expansion of Mac-1+ B-1 cells in the peritoneal and pleuropericardial cavities, and in the blood of IL-9 transgenic mice. In normal mice, the IL-9 receptor was found to be expressed by CD5+ as well as CD5− B-1 cells, and repeated injections of IL-9 resulted in accumulation of B-1 cells in the peritoneal cavity, as observed in transgenic animals. Unlike other mouse models, such as IL-5 transgenic mice, in which expansion of the B-1 population is associated with high levels of autoantibodies, IL-9 did not stimulate the production of autoantibodies in vivo, and most of the expanded cells were found to belong to the B-1b subset (IgM+Mac-1+CD5−). In addition, we found that these IL-9–expanded B-1b cells do not share the well-documented antibromelain-treated red blood cell specificity of CD5+ B-1a cells. The increase of antigen-specific antibody concentration in immunized mice suggests that these B-1 cells are directly or indirectly involved in antibody responses in IL-9 transgenic mice.

Addition of cationic lipids to plasmid DNA considerably increases the efficiency of transfection. The mechanism has not yet been elucidated. A possibility is that these compounds destabilize biological membranes (plasma, endosomal, lysosomal), facilitating the transfer of nucleic molecules through these membranes. We have investigated the problem by determining if a cationic lipid N-(1-(2,3-dioleoxy)propyl)- N, N, N,-trimethylammonium methyl-sulfate (DOTAP, Boehringer, Mannheim, Germany) affects the integrity of rat liver lysosomal membrane. We have measured the latency of β-galactosidase, a lysosomal enzyme, and found that incubation of lysosomes with low concentrations of DOTAP causes a striking increase in free activity of the hydrolase and even a release of the enzyme into the medium. This indicates that lysosomal membrane is deeply destabilized by the lipid. The phenomenon depends on pH, it is less pronounced at pH 5 than at pH 7.4. Anionic compounds, particularly anionic amphipathic lipids, can to some extent prevent this phenomenon. It can be observed with various cationic lipids. A possible explanation is that cationic liposomes interact with anionic lipids of lysosomal membrane, allowing a fusion between the lipid bilayers which results in a destabilization of the organelle membrane.

Efficiency of transfection is probably dependent on the rate of intracellular degradation of plasmid DNA. When a non-viral vector is used, it is not known to what extent the plasmid DNA catabolism is subordinated to the catabolism of the vector. In the work reported here, the problem was approached by following the intracellular fate in rat liver, of plasmid [ 35S]DNA complexed with a cationic peptide poly- l-lysine that can be hydrolyzed by cellular peptidases or with its stereoisomer, poly- d-lysine, that cannot be split by these enzymes. Complexes of DNA with poly- l-lysine and poly- d-lysine are taken up to the same extent by the liver, mainly by Kupffer cells, but the intracellular degradation of nucleic acid molecules is markedly quicker when poly- l-lysine is injected. The association of DNA with the polycations inhibits DNA hydrolysis in vitro by purified lysosomes but similarly for poly- l-lysine and poly- d-lysine. The intracellular journey followed by [ 35S]DNA complexed with poly- l- or poly- d-lysine was investigated using differential and isopycnic centrifugation. Results indicate that [ 35S]DNA is transferred more slowly to lysosomes, the main site of intracellular degradation of endocytosed macromolecules, when it is given as a complex with poly- d-lysine than with poly- l-lysine. They suggest that the digestion of the vector in a prelysosomal compartment is required to allow endocytosed plasmid DNA to rapidly reach lysosomes. Such a phenomenon could explain why injected plasmid DNA is more stable in vivo when it is associated with poly- d-lysine.

Tumor antigen P815AB is recognized by cytolytic T lymphocytes (CTL) on mouse mastocytoma P815. This antigen is encoded by P1A, a gene activated in several tumors but silent in normal tissues except for testis and placenta. Notwithstanding the expression of P1A in testis, we found that male mice mounted P815AB-specific CTL responses as efficiently as females. The responding males remained fertile and no autoimmune lesions were observed in their testes. By immunohistochemistry with a rabbit antiserum directed against the P1A protein, we identified spermatogonia as the testicular cells expressing P1A. The absence of MHC class-1 molecules on spermatogonia could be one of the mechanisms of protection against testicular autoimmunity, as the antigenic peptide should not be displayed at the cell surface. Human genes MAGE, BAGE and GAGE, which also code for tumor antigens recognized by autologous CTL, are not expressed in normal tissues other than testis. The results obtained in mice with antigen P815AB suggest that immunization of human males with such antigens will not generate autoimmune side-effects. Although P1A is strongly expressed in placenta, we also found that gestation did not prevent generation of CTL responses against antigen P815AB, and that such CTL responses did not affect gestation outcome. We identified labyrinthine trophoblasts as the placental cells expressing P1A. Again, the absence of MHC class-1 molecules on these cells provides a plausible explanation for placental protection, although other mechanisms may also play a role. Int. J. Cancer, 70:349–356, 1997. © 1997 Wiley-Liss, Inc.

The isotypic distribution of IgG antibodies was determined in the serum of mice after infection with a panel of RNA and DNA viruses representative of 11 different genera. The antiviral response induced by all these viruses showed a striking preponderance of the IgG2a subclass whatever the strain of mice tested or the time elapsed after infection. Together with the predominance of IgG1 in antiprotein and of IgG3 in anticarbohydrate response, this IgG2a restriction of antiviral antibodies strongly suggests the existence of highly specific mechanisms for the regulation of individual subclasses in the mouse.

Observations were carried out on a total of 247 piglets from 34 litters in order to determine the mechanism and formation factors of teat-order, to evaluate its stability, and to determine their relationship with weight gains and dominance hierarchy.

Murine plasmacytomas show a striking dependence on interleukin 6 (IL-6) for their growth in vitro. Here, we present evidence suggesting that IL-6 also plays an essential role in the in vivo development of these tumors. This conclusion is based on the finding that the tumorigenicity of an IL-6-dependent plasmacytoma cell line was increased approximately 100-fold on transfection with an IL-6 expression vector, whereas it was inhibited in animals treated with monoclonal antibodies capable of blocking the binding of IL-6 to its receptor. Injection of these antibodies 1 d before tumor challenge protected greater than 50% of the mice and retarded tumor growth in all animals. Tumors arising in antibody-treated mice retained their IL-6 dependence in vitro, suggesting that the level of protection could be improved if stronger IL-6 antagonists were available.

Currently DNA-based analysis of blood groups is mainly used to improve transfusion safety by reducing alloantibody formation in multiply transfused patients and by monitoring pregnancies at risk for hemolytic disease of the fetus and newborn. We present a case in which genotyping was performed after massive transfusion with unmatched group O, D– blood in a trauma setting. Our patient was genotyped as O1A1and predicted to be D–, and we therefore transfused group A, D– red blood cell concentrates. This case demonstrates how the use of blood group genotyping in an acute setting can lead to a decrease in the unnecessary use of group O, D– blood products. Immunohematology2012;28:85–7.