Injection Of Homogenate Research Articles

Oral Administration of Lactococcus lactis Expressing Synthetic Genes of Myelin Antigens in Decreasing Experimental Autoimmune Encephalomyelitis in Rats.

BackgroundMultiple sclerosis is a human autoimmunological disease that causes neurodegeneration. One of the potential ways to stop its development is induction of oral tolerance, whose effect lies in decreasing immune response to the fed antigen. It was shown in animal models that administration of specific epitopes of the three main myelin proteins – myelin oligodendrocyte glycoprotein (MOG), myelin basic protein (MBP), and proteolipid protein (PLP) – results in induction of oral tolerance and suppression of disease symptoms. Use of bacterial cells to produce and deliver antigens to gut mucosa seems to be an attractive method for oral tolerance induction in treatment of diseases with autoimmune background.Material/MethodsSynthetic genes of MOG35-55, MBP85-97, and PLP139-151 myelin epitopes were generated and cloned in Lactococcus lactis under a CcpA-regulated promoter. The tolerogenic effect of bacterial preparations was tested on experimental autoimmune encephalomyelitis, which is the animal model of MS. EAE was induced in rats by intradermal injection of guinea pig spinal cord homogenate into hind paws.ResultsRats were administered preparations containing whole-cell lysates of L. lactis producing myelin antigens using different feeding schemes. Our study demonstrates that 20-fold, but not 4-fold, intragastric administration of autoantigen-expressing L. lactis cells under specific conditions reduces the clinical symptoms of EAE in rats.ConclusionsThe present study evaluated the use of myelin antigens produced in L. lactis in inhibiting the onset of experimental autoimmune encephalomyelitis in rats. Obtained results indicate that application of such recombinant cells can be an attractive method of oral tolerance induction.

Release-active antibodies to S100 protein are able to improve the experimental allergic encephalomyelitis

To reveal the effects of release-active antibodies to S100 protein in an animal model of multiple sclerosis. Sixty female Wistar rats, aged 12 weeks, were included in the study. The pathology was induced by subcutaneous injection of the spinal cord homogenate. Afterwards the rats received a water solution of release-active antibodies to S100 protein (2,5 ml/kg/day, tenoten) or distilled water intragastrically during 30 days. Intramuscular injections of glatiramer acetate (4 mg/kg/day, copaxone) were used as a positive control. Release-active antibodies to S100 protein enhanced the latency period of the disease, reduced its peak intensity and compensated the loss of body weight of the animals. The experimental drug effect was similar to the results of copaxone injections.

Differential responses of Africanized and European honey bees (Apis mellifera) to viral replication following mechanical transmission or Varroa destructor parasitism

For the first time, adults and brood of Africanized and European honey bees (Apis mellifera) were compared for relative virus levels over 48h following Varroa destructor parasitism or injection of V. destructor homogenate. Rates of increase of deformed wing virus (DWV) for Africanized versus European bees were temporarily lowered for 12h with parasitism and sustainably lowered over the entire experiment (48h) with homogenate injection in adults. The rates were also temporarily lowered for 24h with parasitism but were not affected by homogenate injection in brood. Rates of increase of black queen cell virus (BQCV) for Africanized versus European bees were similar with parasitism but sustainably lowered over the entire experiment with homogenate injection in adults and were similar for parasitism and homogenate injection in brood. Analyses of sac brood bee virus and Israeli acute paralysis virus were limited as detection did not occur after both homogenate injection and parasitism treatment, or levels were not significantly higher than those following control buffer injection. Lower rates of replication of DWV and BQCV in Africanized bees shows that they may have greater viral resistance, at least early after treatment.

Functional characterization of neuroendocrine regulation of branchial carbonic anhydrase induction in the euryhaline crab Callinectes sapidus.

Carbonic anhydrase (CA) plays an essential role as a provider of counterions for Na(+)/H(+) and Cl(-)/HCO3 (-) exchange in branchial ionic uptake processes in euryhaline crustaceans. CA activity and gene expression are low in crabs acclimated to full-strength seawater, with transfer to low salinity resulting in large-scale inductions of mRNA and subsequent enzyme activity in the posterior ion-regulating gills (e.g., G7). In the green crab Carcinus maenas, CA has been shown to be under inhibitory neuroendocrine control by a putative hormone in the x-organ-sinus gland complex (XOSG), located in the eyestalk. This study characterizes the neuroendocrine regulation of CA induction in the blue crab Callinectes sapidus, a commonly used experimental organism for crustacean osmoregulation. In crabs acclimated to full-strength seawater, eyestalk ligation (ESL) triggered a 1.8- and 100-fold increase in CA activity and mRNA, respectively. Re-injection with eyestalk homogenates abolished increases in CA activity and fractionally reduced CA gene expression. ESL also enhanced CA induction by 33% after 96 h in crabs transferred to 15 ppt salinity. Injection of eyestalk homogenates into intact crabs transferred from 35 to 15 ppt diminished by 43% the CA induction stimulated by low salinity. These results point to the presence of a repressor hormone in the eyestalk. Separate injections of medullary tissue (MT) and sinus gland (SG), two components of the eyestalk, reduced salinity-stimulated CA activity by 22% and 49%, suggesting that the putative repressor is localized to the SG. Crabs injected with SG extract harvested from crabs acclimated to 5 ppt showed no decrease in CA activity, demonstrating that the hormone is down-regulated at low salinity. Our results show the presence in the XOSG of an inhibitory compound that regulates salinity-stimulated CA induction.

Sequenced combustion characteristics, emission and thermal efficiency in gasoline homogeneous charge induced ignition

In this study, the concept of Homogeneous Charge Induced Ignition (HCII) is employed using port-injection of the high-volatile fuel (gasoline) to prepare in-cylinder homogeneous charge and direct injection of the high-ignitable fuel (diesel) near the top dead center (TDC) to control the start of combustion. The experiment was conducted on a single cylinder research engine with compression ratio of 16.7. The engine was operated at an engine speed of 1600rpm for the IMEP from 0.3 to 0.8MPa while the EGR was varied between 0% and 35%. Three different sequential heat release modes with HCII are studied, i.e., slow single-stage combustion (SSC), two-stage combustion (TSC) and fast single-stage combustion (FSC). The FSC mode is close to constant-volume combustion and the TSC mode is close to constant-pressure combustion. The FSC mode has high pressure rise rate and low thermal efficiency due to heat transfer. The TSC mode features high thermal efficiency and smoother pressure rise rate whereas the SSC mode should be avoided due to its high emissions of HC and CO and low thermal efficiency. TSC can be utilized for high load operation under the restricted conditions of peak in-cylinder pressure and combustion noise. NOx and soot emissions can be reduced significantly by using EGR for TSC. Heat release contribution of gasoline and diesel in dual-fuel combustion was distinguished by specially designed experiment. It is found that the first-stage heat release is from the local mixture of diesel and gasoline, and the second-stage heat release is from the premixed gasoline. As the diesel–gasoline ratio increases from 10% to 30%, the contribution of the first-stage combustion to the total heat release increases from 25% to 50% approximately in which the contribution from gasoline increases from 15% to 20%.

Lifetime Characterization of Mc:Si Bricks by Upgraded µ-PCD Technique

A very efficient way is introduced to improve the application of the conventional µ-PCD lifetime mapping technique to bulk photovoltaic grade Si materials (ingots, blocks). The shape of the recorded photoconductance decay curves are strongly impacted by the properties of the laser applied for the electron-hole pair generation. Replacing the original laser configuration to an optimized setup, the impact of the surface recombination can be reduced resulting in significantly longer measurable decay times. It makes possible the better carrier lifetime characterization of the good quality part of the Si bricks. Additionally, unlike similar techniques the suggested realization of µ-PCD gives a relatively homogenous injection level of the measurement along the entire Si bricks. Experimental and simulation results are in excellent agreement, and confirm the enhanced applicability of the upgraded µ-PCD technique.

Dust concentration measurements during filling of a silo and CFD modeling of filling processes regarding exceeding the lower explosion limit

Measurement and numerical simulation of local dust concentrations over time in a vessel can only be done with some uncertainty due to the complexity of the behavior of dust/air mixtures. Dust concentration was measured in a 50 m3 vessel and compared to simulations with a commercial CFD code. A 50 m3 silo was used with two different filling methods. In one setup dust was conveyed with pneumatic filling at the top. The other filling was done with pressurized air and a homogenous injection via eight nozzles. Experiments were repeated three to four times with two kinds of dusts and the results were used to evaluate reproducibility of dust concentration measurements over time in a vessel depending on the filling method. Dust concentrations over time varied up to 30% from the average for homogenous injection and even more for pneumatic filling.Numerical investigations were done with maize starch. Measured concentrations were compared to simulated ones with the commercial CFD code ANSYS CFX R14 using an Euler/Lagrange approach. Drag force, turbulent dispersion force, particle size distribution, particle surface area and particle/particle interaction were modeled. A general agreement of measurement and simulation was achieved. Numerical simulations of filling processes were used to predict parts of the vessel where the lower explosion limit is reached and exceeded. This could help to improve dust explosion protection, if it is used to find configurations where the dust concentration exceeds the lower explosion limit only in small parts of the vessel during filling, e.g. using different injection points or injection angles. The volume where LEL is reached or exceeded in a 50 m3 silo is shown for pneumatic and homogenous filling. Volume of combustible atmosphere in the vessel over time is compared for two pneumatic filling configurations and one worst-case homogenous injection configuration.

An experimental study on thymus immune tolerance to treat surgical brain injury

Background Many researches demonstrate that the secondary brain injury which is caused by autoimmune attack toward brain antigens plays an important role in surgical brain injury (SBI). Although traditional immunosuppression can reduce autoimmune attack, it will lower the body immunity. Immune tolerance, by contrast, not only does not lower the body immunity, but also could lighten autoimmunity. This study used thymus tolerance to develop an immune system that is tolerant to autologous cerebrospinal fluid (CSF) and autologous brain tissue so that autoimmune injury can be suppressed following the disruption of the blood-brain barrier, thereby reducing brain damage. Methods Eighty experimental rabbits were divided into five groups by random number table method: 16 in SBI group (group A), 16 in SBI+CSF drainage group (group B), 16 in SBI+CSF drainage+PBS injection group (group C), 16 in SBI+CSF drainage+CSF intrathymic injection group (group D), and 16 in SBI+brain homogenate intrathymic injection group (group E). Rabbits’ CSF was drained in group B; was drained and injected PBS into thymus in group C; was drained and injected CSF into thymus in group D; and was injected brain homogenate in group E. Half of the rabbits in each group were phlebotomized on 1st, 3rd, 7th, and 14th days to observe the changes in IL-l, TGF-β by ELISA test, and CD4CD25 regulatory T cells ratio by flow cytometry, and in other animals brain tissues were taken on 7th day for exploring FasL expression by RT-PCR. The least significant difference (LSD) test was used to make paired comparisons; P <0.05 was considered statistically significant. Results The levels of FasL, TGF-β, and the ratios of CD4CD25 regulatory T cells in groups D and E were apparently higher than those in other three groups (P <0.05). Likewise, the levels of IL-1 in these two groups were lower than the other three groups (P <0.05). Moreover, the ratios of CD4CD25 regulatory T cells and the levels of TGF-β in groups B and C were higher than those in group A, but the level of IL-1 was lower than that in group A (P <0.05). There was no significant difference between groups B and C, and groups D and E. Conclusion Thymic injection of CSF and brain homogenate may be able to reduce inflammation after SBI, so thymus immune tolerance may be a useful therapy to treat SBI.

Gravitational collapse and thermalization in the hard wall model

We study a simple example of holographic thermalization in a confining field theory: the homogeneous injection of energy in the hard wall model. Working in an amplitude expansion, we find black brane formation for sufficiently fast energy injection and a scattering wave solution for sufficiently slow injection. We comment on our expectations for more sophisticated holographic QCD models.

Effects of premixed ratio on combustion characteristics of a homogeneous charge compression ignition-direct injection engine fueled with dimethyl ether

A two-cylinder, direct injection diesel engine was modified for a homogeneous charge compression ignition-direct injection (HCCI-DI) engine fueled with dimethyl ether. Effects of premixed ratio on HCCI-DI combustion characteristics were experimentally investigated. The results show that in HCCI-DI combustion, as premixed ratio Rp increases, the peak pressure increases and its phase advances gradually; the first peak of pressure rise rate increases and the second peak decreases, and their phase advances gradually. With the increase of Rp, the cool flame peak increases gradually, the peaks of premixed combustion and diffusion combustion decrease gradually. The in-cylinder pressure is decomposed using discrete wavelet transform, the details D1, D2, D3, D4, D5, and D6 are obtained. The relative energy value of pressure at D6, D5, and D4 decreases gradually. The same results are obtained at 0.32 MPa brake mean effective pressure (BMEP), 0.24 MPa BMEP, and 0.16 MPa BMEP. The combustion state plays an important role in determining wavelet relative energy distribution of in-cylinder pressure over details. With increases of Rp, the energy value of in-cylinder pressure at D6 increases gradually, but the energy value at D5 and D4 decreases. It transforms from at D4 and at D5, to at D6 with the increase of Rp.

Seizure-induced alterations in fast-spiking basket cell GABA currents modulate frequency and coherence of gamma oscillation in network simulations

Gamma frequency oscillations have been proposed to contribute to memory formation and retrieval. Fast-spiking basket cells (FS-BCs) are known to underlie development of gamma oscillations. Fast, high amplitude GABA synapses and gap junctions have been suggested to contribute to gamma oscillations in FS-BC networks. Recently, we identified that, apart from GABAergic synapses, FS-BCs in the hippocampal dentate gyrus have GABAergic currents mediated by extrasynaptic receptors. Our experimental studies demonstrated two specific changes in FS-BC GABA currents following experimental seizures [Yu et al., J. Neurophysiol. 109, 1746 (2013)]: increase in the magnitude of extrasynaptic (tonic) GABA currents and a depolarizing shift in GABA reversal potential (E(GABA)). Here, we use homogeneous networks of a biophysically based model of FS-BCs to examine how the presence of extrasynaptic GABA conductance (g(GABA-extra)) and experimentally identified, seizure-induced changes in g(GABA-extra) and E(GABA) influence network activity. Networks of FS-BCs interconnected by fast GABAergic synapses developed synchronous firing in the dentate gamma frequency range (40-100 Hz). Systematic investigation revealed that the biologically realistic range of 30 to 40 connections between FS-BCs resulted in greater coherence in the gamma frequency range when networks were activated by Poisson-distributed dendritic synaptic inputs rather than by homogeneous somatic current injections, which were balanced for FS-BC firing frequency in unconnected networks. Distance-dependent conduction delay enhanced coherence in networks with 30-40 FS-BC interconnections while inclusion of gap junctional conductance had a modest effect on coherence. In networks activated by somatic current injections resulting in heterogeneous FS-BC firing, increasing g(GABA-extra) reduced the frequency and coherence of FS-BC firing when E(GABA) was shunting (-74 mV), but failed to alter average FS-BC frequency when E(GABA) was depolarizing (-54 mV). When FS-BCs were activated by biologically based dendritic synaptic inputs, enhancing g(GABA-extra) reduced the frequency and coherence of FS-BC firing when E(GABA) was shunting and increased average FS-BC firing when E(GABA) was depolarizing. Shifting E(GABA) from shunting to depolarizing potentials consistently increased network frequency to and above high gamma frequencies (>80 Hz). Since gamma oscillations may contribute to learning and memory processing [Fell et al., Nat. Neurosci. 4, 1259 (2001); Jutras et al., J. Neurosci. 29, 12521 (2009); Wang, Physiol. Rev. 90, 1195 (2010)], our demonstration that network oscillations are modulated by extrasynaptic inhibition in FS-BCs suggests that neuroactive compounds that act on extrasynaptic GABA receptors could impact memory formation by modulating hippocampal gamma oscillations. The simulation results indicate that the depolarized FS-BC GABA reversal, observed after experimental seizures, together with enhanced spillover extrasynaptic GABA currents are likely to promote generation of focal high frequency activity associated with epileptic networks.

A Xenograft Mantle Transplantation Technique for Producing a Novel Pearl in an Akoya Oyster Host

The brightness and color of pearls varies among different pearl-producing shellfish and have been a source of human fascination since ancient times. When produced through cultivation, the characteristics and quality of a pearl depend on the kind of shellfish used and also the transplanted mantle graft. This suggests that the Akoya pearl oyster, which is generally used in Japan for pearl culturing, can produce different kinds of pearl through the use of mantles from different species of shellfish. However, a transplanted heterogeneous mantle would be rejected by the immune system of the Akoya oyster. We have therefore developed a new method to suppress the Akoya immune system that archives immune tolerance to other shellfish. It is generally known that small quantities of antigens can be used to produce archived immunological tolerance in a clinical setting. We successfully suppressed the Akoya pearl oyster immune response against a Mabé pearl oyster graft through repeat injections of mantle homogenates. We then transplanted a Mabé pearl oyster mantle graft into the immunologically tolerant Akoya pearl oyster and obtained a Mabé pearl from an Akoya pearl oyster. Our new technique thus makes the production of novel and different pearls in the Akoya possible. We believe that this has significant future potential for the advancement of the pearl industry.

Metallothionein I+II Expression as an Early Sign of Chronic Relapsing Experimental Autoimmune Encephalomyelitis in Rats

Metallothioneins (MTs) are small, cysteine-rich proteins which have been implicated in various forms of stress providing cytoprotective action against oxidative injury, DNA damage and apoptosis. Owing to their high affinity for physiological metals, such as zinc and copper MTs are also critical components of regulatory proteins involved in cell growth and multiplication, as well as in the maintenance of immune homeostasis. To elucidate the role of MTs in the pathomechanisms of autoimmune CNS disorders we estimated the expression of MT I+II proteins and the content of free Zn ions in the brain, spinal cord and in the liver early in the course of chronic relapsing experimental autoimmune encephalomyelitis (CR-EAE) pathogenesis, i.e. before the onset of any clinical symptoms. Disease was induced in the genetically susceptible Dark Agouti (DA) rats by subcutaneous injection of bovine brain homogenate in CFA. Control animals were treated with CFA alone. The data, obtained by immuno-histochemistry and in situ fluorescent labeling of free zinc ions, have shown that in the presymptomatic phase of CR-EAE (on the seventh postimmunization day) MTs I+II were markedly upregulated in the cells that form blood-brain and blood-cerebrospinal fluid barriers, as well as in the cerebellar parenchyma and hippocampal dentate gyri. Furthermore, we found that the liver also becomes a site of extensive MTs I+II synthesis shortly after immunization. Simultaneously, tissue content of free zinc ions increased at the sites of MTs induction, reflecting their antioxidative activity. The data, described in this paper point to regulatory and neuroprotective role of MTs in the pathogenesis of CR-EAE.

Brain homogenates from human tauopathies induce tau inclusions in mouse brain

Filamentous inclusions made of hyperphosphorylated tau are characteristic of numerous human neurodegenerative diseases, including Alzheimer's disease, tangle-only dementia, Pick disease, argyrophilic grain disease (AGD), progressive supranuclear palsy, and corticobasal degeneration. In Alzheimer's disease and AGD, it has been shown that filamentous tau appears to spread in a stereotypic manner as the disease progresses. We previously demonstrated that the injection of brain extracts from human mutant P301S tau-expressing transgenic mice into the brains of mice transgenic for wild-type human tau (line ALZ17) resulted in the assembly of wild-type human tau into filaments and the spreading of tau inclusions from the injection sites to anatomically connected brain regions. Here we injected brain extracts from humans who had died with various tauopathies into the hippocampus and cerebral cortex of ALZ17 mice. Argyrophilic tau inclusions formed in all cases and following the injection of the corresponding brain extracts, we recapitulated the hallmark lesions of AGD, PSP and CBD. Similar inclusions also formed after intracerebral injection of brain homogenates from human tauopathies into nontransgenic mice. Moreover, the induced formation of tau aggregates could be propagated between mouse brains. These findings suggest that once tau aggregates have formed in discrete brain areas, they become self-propagating and spread in a prion-like manner.

Study of dual-fuel (diesel + natural gas) particle matter and CO2 emissions of a heavy-duty diesel engine during transient operation

The aim of this study is to describe the impact on particle matter and co 2 emissions of converting an existing heavy-duty diesel engine for on-highway truck applications to a dual-fuel engine (diesel + natural gas), especially in transient operation. A dual-fuel engine with homogeneous gas charge injection in the intake line before turbocharger was considered. The results showed the feasibility of this kind of technology for transient operation reaching a significant reduction of particle matter plus a decrement in co 2 emissions at the expense of a small decrement of brake fuel conversion efficiency and an increment of unburned hydrocarbons in the exhaust gases.

Cerebral Biochemical Pathways in Experimental Autoimmune Encephalomyelitis and Adjuvant Arthritis: A Comparative Metabolomic Study

Many diseases, including brain disorders, are associated with perturbations of tissue metabolism. However, an often overlooked issue is the impact that inflammations outside the brain may have on brain metabolism. Our main goal was to study similarities and differences between brain metabolite profiles of animals suffering from experimental autoimmune encephalomyelitis (EAE) and adjuvant arthritis (AA) in Lewis rat models. Our principal objective was the determination of molecular protagonists involved in the metabolism underlying these diseases. EAE was induced by intraplantar injection of complete Freund’s adjuvant (CFA) and spinal-cord homogenate (SC-H), whereas AA was induced by CFA only. Naive rats served as controls (n = 9 for each group). Two weeks after inoculation, animals were sacrificed, and brains were removed and processed for metabolomic analysis by NMR spectroscopy or for immunohistochemistry. Interestingly, both inflammatory diseases caused similar, though not identical, changes in metabolites involved in regulation of brain cell size and membrane production: among the osmolytes, taurine and the neuronal marker, N-acetylaspartate, were decreased, and the astrocyte marker, myo-inositol, slightly increased in both inoculated groups compared with controls. Also ethanolamine-containing phospholipids, sources of inflammatory agents, and several glycolytic metabolites were increased in both inoculated groups. By contrast, the amino acids, aspartate and isoleucine, were less concentrated in CFA/SC-H and control vs. CFA rats. Our results suggest that inflammatory brain metabolite profiles may indicate the existence of either cerebral (EAE) or extra-cerebral (AA) inflammation. These inflammatory processes may act through distinct pathways that converge toward similar brain metabolic profiles. Our findings open new avenues for future studies aimed at demonstrating whether brain metabolic effects provoked by AA are pain/stress-mediated and/or due to the presence of systemic proinflammatory molecules. Regardless of the nature of these mechanisms, our findings may be of interest for future clinical studies, e.g. by in-vivo magnetic resonance spectroscopy.

Development of an n-heptane/toluene/polyaromatic hydrocarbon mechanism and its application for combustion and soot prediction

A chemical reaction mechanism has been developed for modeling the combustion process and polyaromatic hydrocarbon formation of diesel and n-heptane/toluene fuels. A reduced n-heptane/polyaromatic hydrocarbon mechanism was applied and updated to better predict the formation of polyaromatic hydrocarbon up to four rings (A4) in ethylene and n-heptane premixed flames. In addition, a reduced toluene mechanism was updated and combined with the n-heptane/polyaromatic hydrocarbon mechanism to predict the combustion and polyaromatic hydrocarbon formation of diesel and n-heptane/toluene fuels. The final mechanism consists of 71 species and 360 reactions. This mechanism was validated with experimental ignition delay data in shock tubes, premixed flame species concentration profiles, homogeneous charge compression ignition combustion and direct injection spray combustion data. A practical multistep soot model was integrated with the polyaromatic hydrocarbon kinetic model to predict soot emissions of diesel and n-heptane/toluene direct injection engine data. Constant-volume combustion vessel simulations were also conducted and the effects of combustion parameters, such as temperature and equivalence ratio, together with the n-heptane/toluene ratio on polyaromatic hydrocarbon and soot formation are discussed. The results show that the present mechanism provides promising agreement in terms of polyaromatic hydrocarbon prediction for various fuels in premixed flames and highlights the importance of aromatics on the polyaromatic hydrocarbon formation and soot emissions. Homogeneous charge compression ignition combustion and direct injection spray combustion simulation results confirm that the present mechanism gives reliable predictions of combustion and soot emissions for both diesel and n-heptane/toluene fuels under various conditions.

Expression pattern of the endoplasmic reticulum stress protein gp96 in monophasic and chronic relapsing form of experimental autoimmune encephalomyelitis in rats.

Gp96 is the endoplasmic reticulum (ER)-resident molecular chaperone, which is involved in the correction of unfolded proteins, in the activation of proteasome-dependent ER-associated degradation of the misfolded proteins, and in activation of the protein translation that modulates polypeptide traffic into the ER. Furthermore, owing to its peptide chaperone capacity and ability to interact with professional antigen-presenting cells, as well as with growth factors, integrins and Toll-like receptors, it is also endowed with crucial immunological functions acting as a "danger signal" to the innate and adaptive immunity. Considering these properties, in the present study the tissue expression of gp96 was examined during the monophasic and chronic relapsing form of experimental autoimmune encephalomyelitis (CR-EAE), induced in genetically susceptible DA rats by subcutaneous injection of myelin basic protein (MBP) or bovine brain homogenate in complete Freund's adjuvant (CFA). Immunohistochemical analyses were done in periods of attacks and remissions of EAE, and the results were compared with findings in intact rats and those treated only with CFA. The data revealed that the constitutive gp96 expression, found in several neurons and glial cells in the brain and spinal cord of intact animals, significantly diminished during the attacks of CR-EAE. On the contrary, the remission of disease was followed by high upregulation of gp96, mainly in the oligodendrocytes within the white matter, in the neurons of the hippocampal area, as well as in the motoneurons of lumbar spinal cord, suggesting that gp96 might be involved in proteostasis and immune-related pathways linked with the reparative processes in the CNS.

An efficient finite volume method for electric field–space charge coupled problems

Abstract The goal of this paper is to introduce some recently developed finite volume schemes to enable numerical simulation of electric field–space charge coupled problems. The key features of this methodology are the possibility of handling problems with complex geometries and accurately capturing the charge density distribution. The total variation diminishing (TVD) scheme and the improved deferred correction (IDC) scheme are used to compute the convective and diffusive fluxes respectively. Our technique is firstly verified with the computation of hydrostatic solutions in a two coaxial cylinders configuration. The homogeneous and autonomous injection from the inner or outer electrode is considered. Comparison has been made with the analytical solution. The numerical technique is also applied to the problem of corona discharge in a blade-plane configuration. The good agreement between our numerical solution and the one obtained with a combination approach of Finite Element Method (FEM) and Method of Characteristics (MoC) is shown.

Bioassay Studies Support the Potential for Iatrogenic Transmission of Variant Creutzfeldt Jakob Disease through Dental Procedures

BackgroundEvidence is required to quantify the potential risks of transmission of variant Creutzfeldt Jakob (vCJD) through dental procedures. Studies, using animal models relevant to vCJD, were performed to address two questions. Firstly, whether oral tissues could become infectious following dietary exposure to BSE? Secondly, would a vCJD-contaminated dental instrument be able to transmit disease to another patient?MethodsBSE-301V was used as a clinically relevant model for vCJD. VM-mice were challenged by injection of infected brain homogenate into the small intestine (Q1) or by five minute contact between a deliberately-contaminated dental file and the gingival margin (Q2). Ten tissues were collected from groups of challenged mice at three or four weekly intervals, respectively. Each tissue was pooled, homogenised and bioassayed in indicator mice.FindingsChallenge via the small intestine gave a transmission rate of 100% (mean incubation 157±17 days). Infectivity was found in both dental pulp and the gingival margin within 3 weeks of challenge and was observed in all tissues tested within the oral cavity before the appearance of clinical symptoms. Following exposure to deliberately contaminated dental files, 97% of mice developed clinical disease (mean incubation 234±33 days).InterpretationInfectivity was higher than expected, in a wider range of oral tissues, than was allowed for in previous risk assessments. Disease was transmitted following transient exposure of the gingiva to a contaminated dental file. These observations provide evidence that dental procedures could be a route of cross-infection for vCJD and support the enforcement of single-use for certain dental instruments.