Search

Delivering therapeutic agents into the brain via convection-enhanced delivery (CED), a mechanically controlled infusion method, provides an efficient approach to bypass the blood–brain barrier and deliver drugs directly to the targeted focus in the brain. Mathematical methods based on Darcy’s law have been widely adopted to predict drug distribution in the brain to improve the accuracy and reduce the side effects of this technique. However, most of the current studies assume that the hydraulic permeability and porosity of brain tissue are homogeneous and constant during the infusion process, which is less accurate due to the deformability of the axonal structures and the extracellular matrix in brain white matter. To solve this problem, a multiscale model was established in this study, which takes into account the pressure-driven deformation of brain microstructure to quantify the change of local permeability and porosity. The simulation results were corroborated using experiments measuring hydraulic permeability in ovine brain samples. Results show that both hydraulic pressure and drug concentration in the brain would be significantly underestimated by classical Darcy’s law, thus highlighting the great importance of the present multiscale model in providing a better understanding of how drugs transport inside the brain and how brain tissue responds to the infusion pressure. This new method can assist the development of both new drugs for brain diseases and preoperative evaluation techniques for CED surgery, thus helping to improve the efficiency and precision of treatments for brain diseases.

Mechanical properties of brain tissue are very complex and vary with the species, region, method, and dynamic range, and between in vivo and ex vivo measurements. To reconcile this variability, we investigated in vivo and ex vivo stiffness properties of two distinct regions in the human and mouse brain - the hippocampus (HP) and the corpus callosum (CC) - using different methods. Under quasi-static conditions, we examined ex vivo murine HP and CC by atomic force microscopy (AFM). Between 16 and 40Hz, we investigated the in vivo brains of healthy volunteers by magnetic resonance elastography (MRE) in a 3-T clinical scanner. At high-frequency stimulation between 1000 and 1400Hz, we investigated the murine HP and CC ex vivo and in vivo with MRE in a 7-T preclinical system. HP and CC showed pronounced stiffness dispersion, as reflected by a factor of 32-36 increase in shear modulus from AFM to low-frequency human MRE and a 25-fold higher shear wave velocity in murine MRE than in human MRE. At low frequencies, HP was softer than CC, in both ex vivo mouse specimens (p

The changes in brain perfusion and oxygenation in critical illness, which are thought to contribute to brain dysfunction, are unclear due to the lack of methods to measure these variables. We have developed a technique to chronically measure cerebral tissue perfusion and oxygen tension in unanesthetized sheep. Using this technique, we have determined the changes in cerebral perfusion and Po2 during the development of ovine sepsis. In adult Merino ewes, fiber-optic probes were implanted in the brain, renal cortex, and renal medulla to measure tissue perfusion, oxygen tension (Po2), and temperature, and flow probes were implanted on the pulmonary and renal arteries. Conscious sheep were infused with live Escherichia coli for 24 h, which induced hyperdynamic sepsis; mean arterial pressure decreased (from 85.2 ± 5.6 to 71.5 ± 8.7 mmHg), while cardiac output (from 4.12 ± 0.70 to 6.15 ± 1.26 L/min) and total peripheral conductance (from 48.9 ± 8.5 to 86.8 ± 11.5 mL/min/mmHg) increased ( n = 8, all P < 0.001) and arterial Po2 decreased (from 104 ± 8 to 83 ± 10 mmHg; P < 0.01). Cerebral perfusion tended to decrease acutely, although this did not reach significance, but there was a significant and sustained decrease in cerebral tissue Po2 (from 32.2 ± 10.1 to 18.8 ± 11.7 mmHg) after 3 h and to 22.8 ± 5.2 mmHg after 24 h of sepsis ( P < 0.02). Sepsis induced large reductions in both renal medullary perfusion and Po2 but had no effect in the renal cortex. In ovine sepsis, there is an early decrease in cerebral Po2 that is maintained for 24 h despite minimal changes in cerebral perfusion. Cerebral hypoxia may be one of the factors causing sepsis-induced malaise and lethargy.

Objectives To investigate the extent of vatinoxan distribution into sheep brain, and whether vatinoxan influences brain concentrations of xylazine; and to examine the utility of cerebrospinal fluid (CSF) as a surrogate of brain tissue concentrations for vatinoxan and xylazine. Study design Randomised, blinded, experimental study. Animals A total of 14 adult female sheep. Methods Sheep were randomly allocated into two equal groups and premeditated with either intravenous (IV) vatinoxan (750 mu g kg(-1), VX) or saline (SX) administered 10 minutes before IV xylazine (500 mu g kg(-1)). Sedation was subjectively assessed at selected intervals before and after treatments. At 10 minutes after xylazine administration, a venous blood sample was collected and the sheep were immediately euthanised with IV pentobarbital (100 mg kg(-1)). Plasma, CSF and brain tissues were harvested, and concentrations of vatinoxan and xylazine were quantified using liquid chromatography-tandem mass spectrometry. Drug ratios were then calculated and the data were analysed as appropriate. Results The brain-to-plasma and CSF-to-plasma ratios of vatinoxan were 0.06 +/- 0.013 and 0.05 +/- 0.01 (mean +/- standard deviation), respectively. Xylazine brain concentrations were not significantly different (835 +/- 262 versus 1029 +/- 297 ng g(-1) in groups VX and SX, respectively) and were approximately 15-fold higher than those in plasma. The CSF-to-brain ratio of vatinoxan was 0.8 +/- 0.2, whereas xylazine concentrations in the brain were approximately 17-fold greater than those in CSF, with and without vatinoxan. Conclusions and clinical relevance Vatinoxan did not significantly affect sedation with xylazine or the concentrations of xylazine in the brain. CSF is not a good predictor of xylazine concentrations in the brain, whereas vatinoxan concentrations were concordant between the brain and CSF, using the dosages in this study.

Two-photon microscopy has enabled high-resolution imaging of neuroactivity at depth within scattering brain tissue. However, its various realizations have not overcome the tradeoffs between speed and spatiotemporal sampling that would be necessary to enable mesoscale volumetric recording of neuroactivity at cellular resolution and speed compatible with resolving calcium transients. Here, we introduce light beads microscopy (LBM), a scalable and spatiotemporally optimal acquisition approach limited only by fluorescence lifetime, where a set of axially separated and temporally distinct foci record the entire axial imaging range near-simultaneously, enabling volumetric recording at 1.41 × 108 voxels per second. Using LBM, we demonstrate mesoscopic and volumetric imaging at multiple scales in the mouse cortex, including cellular-resolution recordings within ~3 × 5 × 0.5 mm volumes containing >200,000 neurons at ~5 Hz and recordings of populations of ~1 million neurons within ~5.4 × 6 × 0.5 mm volumes at ~2 Hz, as well as higher speed (9.6 Hz) subcellular-resolution volumetric recordings. LBM provides an opportunity for discovering the neurocomputations underlying cortex-wide encoding and processing of information in the mammalian brain. Light beads microscopy is a two-photon microscopy approach that allows high-speed volumetric imaging of neuronal activity at the mesoscale.

The interaction of explosion-induced blast waves with the head (i.e., a direct mechanism) or with the torso (i.e., an indirect mechanism) presumably causes traumatic brain injury. However, the understanding of the potential role of each mechanism in causing this injury is still limited. To address this knowledge gap, we characterized the changes in the brain tissue of rats resulting from the direct and indirect mechanisms at 24 h following blast exposure. To this end, we conducted separate blast-wave exposures on rats in a shock tube at an incident overpressure of 130 kPa, while using whole-body, head-only, and torso-only configurations to delineate each mechanism. Then, we performed histopathological (silver staining) and immunohistochemical (GFAP, Iba-1, and NeuN staining) analyses to evaluate brain-tissue changes resulting from each mechanism. Compared to controls, our results showed no significant changes in torso-only-exposed rats. In contrast, we observed significant changes in whole-body-exposed (GFAP and silver staining) and head-only-exposed rats (silver staining). In addition, our analyses showed that a head-only exposure causes changes similar to those observed for a whole-body exposure, provided the exposure conditions are similar. In conclusion, our results suggest that the direct mechanism is the major contributor to blast-induced changes in brain tissues.

The registration of the mass spectrometry imaging (MSI) data with mouse brain tissue slices from the atlases could perform automatic anatomical interpretation, and the comparison of MSI data in particular brain regions from different mice could be accelerated. However, the current registration of MSI data with mouse brain tissue slices is mainly focused on the coronal. Although the sagittal plane is able to provide more information about brain regions on a single histological slice than the coronal, it is difficult to directly register the complete sagittal brain slices of a mouse as a result of the more significant individualized differences and more positional shifts of brain regions. Herein, by adding the auxiliary line on the two brain regions of central canal (CC) and cerebral peduncle (CP), the registration accuracy of the MSI data with sagittal brain slices has been improved (∼2-5-folds for different brain regions). Moreover, the histological sections with different degrees deformation and different dyeing effects have been used to verify that this pipeline has a certain universality. Our method facilitates the rapid comparison of sagittal plane MSI data from different animals and accelerates the application in the discovery of disease markers.

Inorganic nanostructured materials such as silicon, carbon, metals, and metal oxides have been explored as matrices of low-background signals to assist the laser desorption/ionization (LDI) mass spectrometric (MS) analysis of small molecules, but their applications for imaging of small molecules in biological tissues remain limited in the literature. Titanium dioxide is one of the known nanoparticles (NP) that can effectively assist LDI MS imaging of low molecular weight molecules (LMWM). TiO2 NP is commercially available as dispersions, which can be applied using a chemical solution sprayer. However, aggregation of NP can occur in the dispersions and the aggregated NP can slowly clog the sprayer nozzle. In this work, the use of zinc oxide (ZnO) NP for LDI MS imaging is investigated as a superior alternative due to its dissolution in acidic pH. ZnO NP was found to deliver similar or better results in the imaging of LMWM in comparison to TiO2 NP. The regular acid washes were effective in minimizing clogging and maintaining high reproducibility. High-quality images of mouse sagittal and rat coronal tissue sections were obtained. Ions were detected predominately as Na+ or K+ adducts in the positive ion mode. The number of LMWM detected with ZnO NP was similar to that obtained with TiO2 NP, and only a small degree of specificity was observed.

The blood-brain barrier (BBB) comprises the interface between blood, brain and cerebrospinal fluid. Its primary function, which is mainly carried out by tight junctions, is to stabilize the tightly controlled microenvironment of the brain. To study the development and maintenance of the BBB, as well as various roles their intrinsic mechanisms that play in neurological disorders, suitable measurements are required to demonstrate integrity and functional changes at the interfaces between the blood and brain tissue. Markers and plasma proteins with different molecular weight (MW) are used to measure the permeability of BBB. In addition, the expression changes of tight-junction proteins form the basic structure of BBB, and imaging modalities are available to study the disruption of BBB. In the present review, above mentioned methods are depicted in details, together with the pros and cons as well as the differences between these methods, which maybe benefit research studies focused on the detection of BBB breakdown.

Feed efficiency (FE) is one of the most important economic traits in the porcine industry. In this study, high-throughput RNA sequencing (RNA-seq) was first utilized for brain tissue transcriptome analysis in pigs to indicate the potential genes and biological pathways related to FE in pigs. A total of 8 pigs with either extremely high-FE group (HE-group) or low-FE group (LE-group) were selected from 225 Duroc × (Landrace × Yorkshire) (DLY) pigs for transcriptomic analysis. RNA-seq analysis was performed to determine differentially expressed genes (DEGs) between the HE- and LE-group, and 430 DEGs were identified in brain tissues of pigs (|log

The blood-brain barrier (BBB) is a physical barrier that selectively prevents certain substances from entering the brain through the blood. The BBB protects the brain from germs and causes difficulty in intracranial treatment. The chemotherapy drug temozolomide (TMZ), embedded in nanobubbles (NBs) and combined with persistent luminescent nanoparticles (PLNs), has been used to treat glioblastoma (GBM) effectively through image tracking. Through ultrasound induction, NBs produce cavitation that temporarily opens the BBB. Additionally, the PLNs release near-infrared emission and afterglow, which can penetrate deep tissues and improve the signal-to-noise ratio of bioimages. In this work, the nanosystem crossed the BBB for drug delivery and image tracking over time, allowing the enhancement of the drug's therapeutic effect on GBM. We hope that this nanosystem can be applied to the treatment of different brain diseases by embedding different drugs in NBs.

Background: Detailed pathology analysis and morphological quantification is tedious and prone to errors. Automatic image analysis can help to increase objectivity and reduce time. Here, we present the evaluation of the DeePathology STUDIO™ for automatic analysis of histological whole-slide images using machine learning/artificial intelligence. Objective: To evaluate and validate the use of DeePathology STUDIO for the analysis of histological slides at high resolution. Methods: We compared the DeePathology STUDIO and our current standard method using macros in AxioVision for the analysis of amyloid-β (Aβ) plaques and microglia in APP-transgenic mice at different ages. We analyzed density variables and total time invested with each approach. In addition, we correlated Aβ concentration in brain tissue measured by ELISA with the results of Aβ staining analysis. Results: DeePathology STUDIO showed a significant decrease of the time for establishing new analyses and the total analysis time by up to 90%. On the other hand, both approaches showed similar quantitative results in plaque and activated microglia density in the different experimental groups. DeePathology STUDIO showed higher sensitivity and accuracy for small-sized plaques. In addition, DeePathology STUDIO allowed the classification of plaques in diffuse- and dense-packed, which was not possible with our traditional analysis. Conclusion: DeePathology STUDIO substantially reduced the effort needed for a new analysis showing comparable quantitative results to the traditional approach. In addition, it allowed including different objects (categories) or cell types in a single analysis, which is not possible with conventional methods.

OBJECTIVE To evaluate with CT the characteristics of brain tissue disruption and skull damage in cadaveric heads of adult horses caused by each of 6 firearm-ammunition combinations applied at a novel anatomic aiming point. SAMPLE 53 equine cadaveric heads. PROCEDURES Heads placed to simulate that of a standing horse were shot with 1 of 6 firearm-ammunition combinations applied at an aiming point along the external sagittal crest of the head where the 2 temporalis muscles form an inverted V. Firearm-ammunition combinations investigated included a .22-caliber long rifle pistol firing a 40-grain, plated lead, solid-core or hollow-point bullet (HPB); a semiautomatic 9-mm pistol firing a 115-grain, jacketed HPB; a semiautomatic .223-caliber carbine firing a 55-grain, jacketed HPB; a semiautomatic .45-caliber automatic Colt pistol firing a 230-grain, jacketed HPB; and a 12-gauge shotgun firing a 1-oz rifled slug. Additional heads placed in a simulated laterally recumbent position were shot with the semiautomatic 9-mm pistol–HPB combination. All heads underwent CT before and after being shot, and images were evaluated for projectile fragmentation, skull fracture, and cerebrum, cerebellum, and brainstem disruption. RESULTS Computed tomography revealed that all firearm-ammunition combinations caused disruption of the cerebrum, cerebellum, and brainstem that appeared sufficient to result in instantaneous death of a live horse. Hollow-point ammunition was as effective as solid-core ammunition with regard to brain tissue disruption. Brain tissue disruption was not affected by head positioning. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that the examined firearm-ammunition combinations, when applied at a novel aiming point, appear to be reasonable options for euthanasia of horses.

Deep brain stimulation (DBS) is an effective treatment for Parkinson's disease. The cannula insertion process plays an important role in DBS. The friction force during needle insertion influences the precision of the insertion and the degree of damage to the brain tissue. This paper proposes a method of longitudinal vibration assisted insertion to reduce the friction during insertion and improve the effects of the insertion. Cannulas were inserted into twenty eight pig brains at multiple frequencies and fixed amplitudes, and the resulting friction force was measured. On this basis, the LuGre model was used to analyze the friction force trend under vibration-assisted conditions. The frictional forces of vibration-assisted insertion with frequencies ranging from 200–1200 Hz and an amplitude of 1 μm were measured. The results show that the friction between the needle shaft and the tissue is smaller with vibration than without vibration. In this experiment, the friction is reduced by up to 24.43%. The friction force trend of vibration-assisted insertion conforms to the simulation results of the LuGre model.

Gene expression studies are reported to be influenced by pre-analytical factors that can compromise RNA yield and integrity, which in turn may confound the experimental findings. Here we investigate the impact of four pre-analytical factors on brain-derived RNA: time-before-collection, tissue specimen size, tissue collection method, and RNA isolation method. We report no significant differences in RNA yield or integrity between 20 mg and 60 mg tissue samples collected in either liquid nitrogen or the RNAlater stabilizing solution. Isolation of RNA employing the TRIzol reagent resulted in a higher yield compared to isolation via the QIAcube kit while the latter resulted in RNA of slightly better integrity. Keeping brain tissue samples at room temperature for up to 160 min prior to collection and isolation of RNA resulted in no significant difference in yield or integrity. Our findings have significant practical and financial consequences for clinical genomic departments and other laboratory settings performing large-scale routine RNA expression analysis of brain samples.

Across the fields of virology and neuroscience, the role of neurotropic viruses in Alzheimer’s disease (AD) has received renewed enthusiasm, with a particular focus on human herpesviruses (HHVs). Recent genomic analyses of brain tissue collections and investigations of the antimicrobial responses of amyloid-β do not exclude a role of HHVs in contributing to or accelerating AD pathogenesis. Due to continued expansion in our aging cohort and the lack of effective treatments for AD, this composition examines a potential neuroviral theory of AD in light of these recent data. Consideration reveals a possible viral “Hit-and-Run” scenario of AD, as well as neurobiological mechanisms (i.e., neuroinflammation, protein quality control, oxidative stress) that may increase risk for AD following neurotropic infection. Although limitations exist, this theoretical framework reveals several novel therapeutic targets that may prove efficacious in AD.

Many factors contribute to the health risks encountered by astronauts on missions outside Earth's atmosphere. Spaceflight-induced potential adverse neurovascular damage and late neurodegeneration are a chief concern. The goal of the present study was to characterize the effects of spaceflight on oxidative damage in the mouse brain and its impact on blood-brain barrier (BBB) integrity. Ten-week-old male C57BL/6 mice were launched to the International Space Station (ISS) for 35 days as part of Space-X 12 mission. Ground control (GC) mice were maintained on Earth in flight hardware cages. Within 38 ± 4 hours after returning from the ISS, mice were euthanized and brain tissues were collected for analysis. Quantitative assessment of brain tissue demonstrated that spaceflight caused an up to 2.2-fold increase in apoptosis in the hippocampus compared to the control group. Immunohistochemical analysis of the mouse brain revealed an increased expression of aquaporin4 (AQP4) in the flight hippocampus compared to the controls. There was also a significant increase in the expression of platelet endothelial cell adhesion molecule-1 (PECAM-1) and a decrease in the expression of the BBB-related tight junction protein, Zonula occludens-1 (ZO-1). These results indicate a disturbance of BBB integrity. Quantitative proteomic analysis showed significant alterations in pathways responsible for neurovascular integrity, mitochondrial function, neuronal structure, protein/organelle transport, and metabolism in the brain after spaceflight. Changes in pathways associated with adhesion and molecular remodeling were also documented. These data indicate that long-term spaceflight may have pathological and functional consequences associated with neurovascular damage and late neurodegeneration.

Background: The contribution of gene-environment interactions that lead to excessive aggression is poorly understood. Environmental stressors and mutations of the gene encoding tryptophan hydroxylase-2 (TPH2) are known to influence aggression. For example, TPH2 null mutant mice (Tph2−/−) are naturally highly aggressive, while heterozygous mice (Tph2+/−) lack a behavioral phenotype and are considered endophenotypically normal. Here we sought to discover whether an environmental stressor would affect the phenotype of the genetically ‘susceptible’ heterozygous mice (Tph2+/−). Methods: Tph2+/− male mice or Tph2+/+ controls were subjected to a five-day long rat exposure stress paradigm. Brain serotonin metabolism and the expression of selected genes encoding serotonin receptors, AMPA receptors, and stress markers were studied. Results: Stressed Tph2+/− mice displayed increased levels of aggression and social dominance, whereas Tph2+/+ animals became less aggressive and less dominant. Brain tissue concentrations of serotonin, its precursor hydroxytryptophan and its metabolite 5-hydroxyindoleacetic acid were significantly altered in all groups in the prefrontal cortex, striatum, amygdala, hippocampus and dorsal raphe after stress. Compared to non-stressed animals, the concentration of 5-hydroxytryptophan was elevated in the amygdala though decreased in the other brain structures. The overexpression of the AMPA receptor subunit, GluA2, and downregulation of 5-HT6 receptor, as well as overexpression of c-fos and glycogen-synthase-kinase-3β (GSK3-β), were found in most structures of the stressed Tph2+/− mice. Limitations: Rescue experiments would help to verify causal relationships of reported changes. Conclusions: The interaction of a partial TPH2 gene deficit with stress results in pathological aggression and molecular changes, and suggests that the presence of genetic susceptibility can augment aggression in seemingly resistant phenotypes. © 2020 The Authors 602805 Seventh Framework Programme, FP7 Deutsche Forschungsgemeinschaft, DFG: CRC TRR 58 A1/A5 Horizon 2020 Framework Programme, H2020: 728018 Russian Foundation for Basic Research, RFBR: 15-04-03602 Deutsche Forschungsgemeinschaft, DFG Russian Foundation for Basic Research, RFBR The authors’ work reported here was supported Deutsche Forschungsgemeinschaft (DFG: CRC TRR 58 A1/A5), the European Union's Seventh Framework Programme (FP7/2007–2013) under Grant No. 602805 (Aggressotype) and the Horizon 2020 Research and Innovation Programme under Grant No. 728018 (Eat2beNICE) (to KPL and TS), the “5-100” Russian Academic Excellence Project (to KPL and TS) and the Russian Foundation of Basic Research (RFBR Grant No. 15-04-03602 to TS). We appreciate the valuable technical help of Dr. Joao Costa-Nunes and Dolores Bonopartos with this project.

Background Congenital tremor (CT) type A-II is a neurological disorder characterized by tremor of the head and body of newborn piglets. The suggested causative agent of the disease is the recently found atypical porcine pestivirus (APPV). The virus has been detected in piglets suffering from congenital tremor in central Europe, South and North America and in China but no studies has so far been performed in the Nordic countries. The overarching goal of this study was to investigate if APPV is present in the brain tissue of Swedish piglets suffering from congenital tremor. From June 2017 – June 2018, 15 piglets from four Swedish farms with ongoing outbreaks of congenital tremor and 13 piglets with splay leg originating from four different farms, were investigated for presence of APPV RNA in brain tissue. Matched healthy control piglets (n = 8) were also investigated. Two APPV-specific RT-qPCR methods targeting the NS3 and NS5B region, respectively, were used. A retrospective study was performed on material from Swedish piglets with congenital tremor sampled in 2004 (n = 11) and 2011/2012 (n = 3) using the described APPV-specific RT-qPCR methods. The total number of piglets with signs of CT in this study was 29. Results Atypical porcine pestivirus-RNA was detected in 93% (27/29) of the piglets suffering from congenital tremor. All piglets with congenital tremor from 2004 (n = 11) and 2012 (n = 3) were PCR-positive with respect to APPV, whereas, all of the healthy controls (n = 11) were negative. The piglets with congenital tremor sampled 2017–2018 had an odds ratio of 91.8 (95% CI 3.9128 to 2153.7842, z = 2.807, P = 0.0050) to test positive for APPV by qRT-PCR compared to the healthy piglets (Fishers exact test p Conclusion This is the first description of atypical porcine pestivirus in piglets suffering from congenital tremor type A-II in Sweden and the Nordic countries. The virus has been present in the Swedish pig population since at least 2004.

Canines, which exhibit similar emotional and social processing to humans, are becoming one of the preferred animal models for neuroscience research. Beagles are the most common laboratory canine, thanks to their moderate size, docile nature, and strong immunity. However, there is currently no MRI brain template for the purebred Beagle, which hinders their use in studies involving neuroimaging. Here, we present the Beagle Brain Template (BBT), which consists of high-resolution in vivo T1-weighted and T2-weighted templates, as well as a myelin template, generated from purebred Beagles. We also present a normalized pipeline for mapping individual structure images onto the BBT space. The BBT shows low variation in the tissue probability map and provides descriptive statistics with smaller variability of brain tissue volumes and brain sizes than that of existing templates. This high-resolution purebred canine brain template lays the foundation for future studies aimed at in vivo analyses of the brain structure and function of the Beagle dogs.

In this study, a 1.1 MW diesel-gen-set is used to design a Waste Heat Recovery (WHR) system to generate additional power using Rankine cycle (RC). A computer code is written in commercial Engineering Equation Solver (EES) software to solve equations of overall energy and mass balance, heat transfer, evaporation, condensation, frictional and heat losses for heat exchangers, turbine, pumps, cooling tower and connecting pipes connecting different components. After initial design of the WHR system, manufacturers are contacted to find out the availability of parts, and then, accordingly the design is changed. There are several heat exchangers required to heat the water from liquid to super heated steam and then, it is passed to the turbine. Then, after the expansion in the turbine, it is passed to the condenser to condense the steam to water. Optimization is done on the heat exchangers, focusing on the tube length and diameter. The tube length is changed in accordance to the availability on the market, where it comes in 2 m length. At the rated power of the gen-set, with a pressure ratio of 100 (inlet and outlet pressures to the turbine are 30 bar and 0.3 bar, respectively), an overall improvement of 12.2% is achieved. Results from this study can be applied to large diesel engines used for large trucks which fall in the USA commercial truck category of Class 7 and 8 of heavy trucks, large diesel-gen-set and mobile applications such as ships, heavy construction equipment, ultra-heavy mining movers, excavators and locomotives. It found that the WHR system could be as heavy as the gen-set and they are bulky. Therefore, not only the overall efficiency improvement is important, the size and weight of the WHR system is also very important. Refereed/Peer-reviewed

In November 2017, two groups of P. conspicillatus pups from separate locations in Far North Queensland presented with neurological signs consistent with Australian bat lyssavirus (ABLV) infection. These pups (n = 11) died over an 11-day period and were submitted to a government laboratory for testing where ABLV infection was confirmed. Over the next several weeks, additional ABLV cases in flying foxes in Queensland were also detected. Brain tissue from ABLV-infected flying foxes during this period, as well as archived brain tissue, was selected for next-generation sequencing. Phylogenetic analysis suggests that the two groups of pups were each infected from single sources. They were likely exposed while in crèche at night as their dams foraged. This study identifies crèche-age pups at a potentially heightened risk for mass ABLV infection.

An epizootic caused by a new orthobunyavirus called Schmallenberg virus (SBV) was recognised in European ruminants in 2011 and 2012. The re-emergence of the infection was reported in several countries in the subsequent years. Although the main clinical sign of SBV infection is abortion, the impact of SBV in natural cases of abortion in domestic ruminants had not been systematically examined before this study. The aim of the study was to investigate the role of SBV infection and to compare it to the importance of other causes of abortion by examining 537 natural cases of abortion that had occurred between 2011 and 2017 in Hungary. The cause of abortion was determined in 165 (31%) cases. An infectious cause was proved in 88 (16%) cases. SBV infection was found only in a total of four cases (0.8%) using real-time polymerase chain reaction. Three of them proved to be inapparent SBV infection, and one case was attributed to SBV-induced abortion by detecting non-purulent encephalitis and SBV nucleoprotein by immunohistochemistry in a brain tissue sample. According to the results, SBV played a minor role in natural cases of domestic ruminant abortion in Hungary during the 7-year period following the first SBV outbreak in 2011.

Large scale unbiased quantification of immunohistochemistry (IHC) is time consuming, expensive, and/or limited in scope. Heterogeneous tissue types such as brain tissue have presented a further challenge to the development of automated analysis, as differing cellular morphologies result in either limited applicability or require large amounts of training tissue for machine-learning methods. Here we present the use of QuPath, a free and open source software, to quantify whole-brain sections stained with the immunohistochemical markers IBA1 and AT8, for microglia and phosphorylated tau respectively. The pixel-based method of analysis herein allows for statistical comparison of global protein expression between brains and generates heat-maps of stain intensity, visualizing stain signal across whole sections and permitting more specific investigation of regions of interest. This method is fast, automated, unbiased, and easily replicable. We compared swine brains that had undergone a closed head traumatic brain injury with brains of sham animals, and found a global increase in both microglial signal expression and phosphorylated tau. We discuss the IHC methods necessary to utilize this analysis and provide detailed instruction on the use of QuPath in the pixel-based analysis of whole-slide images.

Objective: In present study, we aimed to clarify effect of aging on the susceptibility of brain tissue to neurodegeneration induced by ischemia.Methods: Damage induced by oxygen-glucose deprivation...

External organic or inorganic objects (foreign bodies) that are inadvertently or purposefully placed in the human or animal tissues can trigger local tissue responses that aim at the elimination and/or segregation of foreign bodies from the tissue. The foreign body response (FBR) may have major implications for neurodegeneration associated with the formation of aberrant protein-based aggregates or plaques. The distinct physical features of the plaques, including high rigidity and varying surface properties, may trigger microglial mechanosensing of the plaque as a foreign body. The microglial FBR may have a dual function by promoting and/or suppressing the plaque driven neurodegeneration. Microglial contact with the plaque may trigger inflammatory activation of microglia and support microglia-driven neuronal damage. Conversely, persistent microglial activation may trigger the formation of a microglia-supported cell barrier that segregates and compacts the plaques thus preventing further plaque-induced damage to healthy neurons.

The present study aims to discuss the effect of escitalopram in glial cell line-derived neurotrophic factor (GDNF), brain-derived neurotrophic factor (BDNF) levels, and 5-Hydroxytryptamine (5-HT) in obsessive–compulsive disorder rats. A total of 42 rats were divided into three groups randomly: control group (n = 14), model group (n = 14) (obsessive–compulsive disorder group), and escitalopram group (n = 14) (model + obsessive–compulsive disorder group + escitalopram treatment). The open-field method was used to test the rat behavior, enzyme-linked immunosorbent assay (ELISA) was used to determine the serum GDNF and BDNF levels. In addition, Western blot was used to determine the brain tissue protein levels of GDNF and BDNF and high-performance liquid chromatography + electrochemistry method to determine the 5-HT level of brain tissue. Visiting place was changed, rotational frequency and fixed duration enhanced in escitalopram group compared to model group (P

Mass spectrometry (MS) has emerged as a valuable technology for molecular and spatial evaluation of biological samples. Ambient ionization MS techniques, in particular, allow direct analysis of tissue samples with minimal pretreatment. Here, we describe the design and optimization of an alternative ambient liquid extraction MS approach for metabolite and lipid profiling and imaging from biological samples. The system combines a piezoelectric picoliter dispenser to form solvent nanodroplets onto the sample surface with controlled and tunable spatial resolution and a conductive capillary to directly aspirate/ionize the nanodroplets for efficient analyte transmission and detection. Using this approach, we performed spatial profiling of mouse brain tissue sections with different droplet sizes (390, 420, and 500 μm). MS analysis of normal and cancerous human brain and ovarian tissues yielded rich metabolic profiles that were characteristic of disease state and enabled visualization of tissue regions with different histologic composition. This method was also used to analyze the lipid profiles of human ovarian cell lines. Overall, our results demonstrate the capabilities of this system for spatially controlled MS analysis of biological samples.

Ischemic stroke, which is caused by a sudden clot in the blood vessels, may cause severe brain tissue damage and has become a leading cause of death globally. Currently, thrombolysis is the gold standard primary treatment of ischemic stroke in clinics. However, the short therapeutic window of opportunity limits thrombolysis utility. Secondary cerebral damage caused by stroke is also an urgent problem. In this review, we discuss the present methods of treating ischemic stroke in clinics and their limitations. Various new drug delivery strategies targeting ischemic stroke lesions have also been summarized, including pharmaceutical methods, diagnostic approaches and other routes. These strategies could change the pharmacokinetic behavior, improve targeted delivery or minimize side effects. A better understanding of the novel approaches utilized to facilitate drug delivery in ischemic stroke would improve outcomes.

We evaluated oxyphytosterol (OPS) concentrations in plasma and various tissues of two genetically modified mouse models with either increased cholesterol (apoE KO mice) or increased cholesterol and plant sterol (PS) concentrations (apoExABCG8 dKO mice). Sixteen female apoE KO and 16 dKO mice followed the same standard, low OPS-chow diet. Animals were euthanized at 36 weeks to measure PS and OPS concentrations in plasma, brain, liver and aortic tissue. Cholesterol and oxysteml (OS) concentrations were analyzed as reference for sterol oxidation in general. Plasma campesterol (24.1 +/- 4.3 vs. 11.8 +/- 3.0 mg/dL) and sitosterol (67.4 +/- 12.7 vs. 4.9 +/- 1.1 mg/dL) concentrations were severely elevated in the dKO compared to the apoE KO mice (p < 0.001). Also, in aortic and brain tissue, PS levels were significantly elevated in dKO. However, plasma, aortic and brain OPS concentrations were comparable or even lower in the dKO mice. In contrast, in liver tissue, both PS and OPS concentrations were severely elevated in the dKO compared to apoE KO mice (sum OPS: 7.4 +/- 1.6 vs. 4.1 +/- 0.8 ng/mg, p < 0.001). OS concentrations followed cholesterol concentrations in plasma and all tissues suggesting ubiquitous oxidation. Despite severely elevated PS concentrations, OPS concentrations were only elevated in liver tissue, suggesting that OPS are primarily formed in the liver and plasma concentrations originate from hepatic spill-over into the circulation.

Drug-resistant epilepsy (DRE) affects approximately one-third of the patients with epilepsy. Based on experimental findings from animal models and brain tissue from patients with DRE, different hypotheses have been proposed to explain the cause(s) of drug resistance. One is the intrinsic severity hypothesis that posits that drug resistance is an inherent property of epilepsy related to disease severity. Seizure frequency is one measure of epilepsy severity, but frequency alone is an incomplete measure of severity and does not fully explain basic research and clinical studies on drug resistance; thus, other measures of epilepsy severity are needed. One such measure could be pathological high-frequency oscillations (HFOs), which are believed to reflect the neuronal disturbances responsible for the development of epilepsy and the generation of spontaneous seizures. In this manuscript, we will briefly review the intrinsic severity hypothesis, describe basic and clinical research on HFOs in the epileptic brain, and based on this evidence discuss whether HFOs could be a clinical measure of epilepsy severity. Understanding the mechanisms of DRE is critical for producing breakthroughs in the development and testing of novel strategies for treatment.

The minimum histological criterion for the diagnostics of Alzheimer’s disease (AD) in tissue is the presence of senile plaques and neurofibrillary tangles in specific brain locations. The routine procedure of morphological analysis implies time-consuming and laborious steps including sectioning and staining of formalin-fixed paraffin-embedded (FFPE) tissue. We developed a multispectral Stokes polarimetric imaging approach that allows characterization of FFPE brain tissue samples to discern the stages of AD progression without sectioning and staining the tissue. The Stokes polarimetry approach is highly sensitive to structural alterations of brain tissue, particularly to the changes in light scattering and birefringence. We present the results of the label-free non-destructive screening of FFPE mouse brain tissue and show several polarization metrics that demonstrate statistically significant differences for tissues at different stages of AD.

Acute ischemic stroke patients benefit from reperfusion in a short time-window after debut. Later treatment may be indicated if viable brain tissue is demonstrated and this outweighs the inherent risks of late reperfusion. Magnetic resonance imaging (MRI) with hyperpolarized [1-13C]pyruvate is an emerging technology that directly images metabolism. Here, we investigated its potential to detect viable tissue in ischemic stroke. Stroke was induced in pigs by intracerebral injection of endothelin 1. During ischemia, the rate constant of pyruvate-to-lactate conversion, kPL, was 52% larger in penumbra and 85% larger in the infarct compared to the contralateral hemisphere (P = 0.0001). Within the penumbra, the kPL was 50% higher in the regions that later infarcted compared to non-progressing regions (P = 0.026). After reperfusion, measures of pyruvate-to-lactate conversion were slightly decreased in the infarct compared to contralateral. In addition to metabolic imaging, we used hyperpolarized pyruvate for perfusion-weighted imaging. This was consistent with conventional imaging for assessment of infarct size and blood flow. Lastly, we confirmed the translatability of simultaneous assessment of metabolism and perfusion with hyperpolarized MRI in healthy volunteers. In conclusion, hyperpolarized [1-13C]pyruvate may aid penumbral characterization and increase access to reperfusion therapy for late presenting patients.

Immunohistochemical staining of mouse brains is a routine technique commonly used in neuroscience to investigate central mechanisms underlying the regulation of energy metabolism and other neurobiological processes. However, the quality, reliability, and reproducibility of brain histology results may vary among laboratories. For each staining experiment, it is necessary to optimize the key procedures based on differences in species, tissues, targeted proteins, and the working conditions of the reagents. This paper demonstrates a reliable workflow in detail, including intra-aortic perfusion, brain sectioning, free-floating immunostaining, tissue mounting, and imaging, which can be followed easily by researchers in this field. Also discussed are how to modify these procedures to satisfy the individual needs of researchers. To illustrate the reliability and efficiency of this protocol, perineuronal nets were stained with biotin-labeled Wisteria florbunda agglutinin (WFA) and arginine vasopressin (AVP) with an anti-AVP antibody in the mouse brain. Finally, the critical details for the entire procedure have been addressed, and the advantages of this protocol compared to those of other protocols. Taken together, this paper presents an optimized protocol for free-floating immunostaining of mouse brain tissue. Following this protocol makes this process easier for both junior and senior scientists to improve the quality, reliability, and reproducibility of immunostaining studies.

Depression is one of the most common neuropsychiatric disorders in the world. While conventional pharmaceutical therapy targets monoaminergic pathway dysfunction, it has not been totally successful in terms of positive outcomes, remission, and preventing relapses. There is an increasing amount of evidence that neuroinflammation may play a significant part in the pathophysiology of depression. Among the key components of the neuroinflammatory pathways already known to be active are the T helper (Th) cells, especially Th17 cells. While various preclinical and clinical studies have reported increased levels of Th17 cells in both serum and brain tissue of laboratory model animals, contradictory results have argued against a pertinent role of Th17 cells in depression. Recent studies have also revealed a role for more pathogenic and inflammatory subsets of Th17 in depression, as well as IL-17A and Th17 cells in non-responsiveness to conventional antidepressant therapy. Despite recent advances, there is still a significant knowledge gap concerning the exact mechanism by which Th17 cells influence neuroinflammation in depression. This review first provides a short introduction to the major findings that led to the discovery of the role of Th cells in depression. The major subsets of Th cells known to be involved in neuroimmunology of depression, such as Th1, Th17, and T regulatory cells, are subsequently described, with an in-depth discussion on current knowledge about Th17 cells in depression.

There is increasing evidence of altered tissue mechanics in neurodegeneration. However, due to difficulties in mechanical testing procedures and the complexity of the brain, there is still little consensus on the role of mechanics in the onset and progression of neurodegenerative diseases. In the case of Alzheimer’s disease (AD), magnetic resonance elastography (MRE) studies have indicated viscoelastic differences in the brain tissue of AD and healthy patients. However, there is a lack of viscoelastic data from contact mechanical testing at higher spatial resolution. Therefore, we report viscoelastic maps of the hippocampus obtained by a dynamic indentation on brain slices from the APP/PS1 mouse model where individual brain regions are resolved. A comparison of viscoelastic parameters shows that regions in the hippocampus of the APP/PS1 mice are significantly stiffer than wild-type (WT) mice and have increased viscous dissipation. Furthermore, indentation mapping at the cellular scale directly on the plaques and their surroundings did not show local alterations in stiffness although overall mechanical heterogeneity of the tissue was high (SD~40%). Therefore, reported mechanical alterations at a tissue scale indicates global remodeling of the brain tissue structure.

Despite the widespread use of gold nanoparticles (GNPs), there is no consensus on their distribution to different tissues and organs. The present systematic review and meta-analysis addresses the accumulation of GNPs in brain tissue. Extensive searches were conducted in electronic databases, Medline, Web of Science, EMBASE, and Scopus. Based on inclusion and exclusion criteria, primary and secondary screening was performed. The value of brain accumulation of gold nanoparticle (the percentage of the injection dose of GNPs/gram of brain tissue that applied as effect size (ES) in analysis) and the standard error of the mean were extracted from articles and analyzed by calculating the pooled ES and the pooled confidence interval (CI) using STATA software. p ≤ 0.05 was considered significant. Thirty-eight studies were included in the meta-analysis. The results showed that the amount of GNPs was 0.06% of the injection dose/gram of brain tissue (ES = 0.06, %95 CI: 0.06-0.06, p

Reactive oxygen species (ROS) produced by an inflammatory response in the brain are associated with various neurological disorders. To investigate ROS-associated neuroinflammatory diseases, fluorescent probes with practicality are in demand. We have investigated hypochlorous acid, an important ROS, in the brain tissues of neuroinflammation and maternal immune activation (MIA) model mice, using a new fluorescent probe. The probe has outstanding features over many known probes, such as providing two bright ratio signals in cells and tissues in deep-red/near-infrared wavelength regions with a large spectral separation, in addition to being strongly fluorescent, photo- and chemo-stable, highly selective and sensitive, fast responding, and biocompatible. We have found that the level of hypochlorous acid in the brain tissue of a neuroinflammatory mouse model was higher (2.7-4.0-fold) compared with that in normal brain tissue. Furthermore, the level of hypochlorous acid in the brain tissue of a MIA mouse model was higher (1.2-1.3-fold) compared with that in the normal brain tissue. The "robust" probe provides a practical tool for studying ROS-associated neurological disorders.

The mechanical characterization of brain tissue has been generally analyzed in the frequency and time domain. It is crucial to understand the mechanics of the brain under realistic, dynamic conditions and convert it to enable mathematical modelling in a time domain. In this study, the compressive viscoelastic properties of brain tissue were investigated under time and frequency domains with the same physical conditions and the theory of viscoelasticity was applied to estimate the prediction of viscoelastic response in the time domain based on frequency-dependent mechanical moduli through Finite Element models. Storage and loss modulus were obtained from white and grey matter, of bovine brains, using dynamic mechanical analysis and time domain material functions were derived based on a Prony series representation. The material models were evaluated using brain testing data from stress relaxation and hysteresis in the time dependent analysis. The Finite Element models were able to represent the trend of viscoelastic characterization of brain tissue under both testing domains. The outcomes of this study contribute to a better understanding of brain tissue mechanical behaviour and demonstrate the feasibility of deriving time-domain viscoelastic parameters from frequency-dependent compressive data for biological tissue, as validated by comparing experimental tests with computational simulations.

Summary Microglial dynamics and interactions with nearby radial glia can be visualized in real time in embryonic mouse brain tissue using time-lapse imaging in slice culture. This live-cell imaging protocol can be used to study the morphology and activities of a number of cell types across a variety of brain regions and developmental time points. The advantage of this brain slice culture model is that it allows for the visualization of cellular interactions and movements in real time, especially across embryogenesis. For complete details on the use and execution of this protocol, please refer to Rosin et al. (2021)., Graphical abstract, Highlights • Microglia and radial glia interactions can be captured in embryonic brain slices • Microglial dynamics and interactions with nearby cells can be visualized in real time • Live-cell imaging can be used to study various cell types in the developing brain, Microglial dynamics and interactions with nearby radial glia can be visualized in real time in embryonic mouse brain tissue using time-lapse imaging in slice culture. This live-cell imaging protocol can be used to study the morphology and activities of a number of cell types across a variety of brain regions and developmental time points. The advantage of this brain slice culture model is that it allows for the visualization of cellular interactions and movements in real time, especially across embryogenesis.

STED microscopy is one of several fluorescence microscopy techniques that permit imaging at higher spatial resolution than what the diffraction-limit of light dictates. STED imaging is unique among these super-resolution modalities in being a beam-scanning microscopy technique based on confocal or 2-photon imaging, which provides the advantage of superior optical sectioning in thick samples. Compared to the other super-resolution techniques that are based on widefield microscopy, this makes STED particularly suited for imaging inside live brain tissue, such as in slices or in vivo. Notably, the 50nm resolution provided by STED microscopy enables analysis of neural morphologies that conventional confocal and 2-photon microscopy approaches cannot resolve, including all-important synaptic structures. Over the course of the last 20years, STED microscopy has undergone extensive developments towards ever more versatile use, and has facilitated remarkable neurophysiological discoveries. The technique is still not widely adopted for live tissue imaging, even though one of its particular strengths is exactly in resolving the nanoscale dynamics of synaptic structures in brain tissue, as well as in addressing the complex morphologies of glial cells, and revealing the intricate structure of the brain extracellular space. Not least, live tissue STED microscopy has so far hardly been applied in settings of pathophysiology, though also here it shows great promise for providing new insights. This review outlines the technical advantages of STED microscopy for imaging in live brain tissue, and highlights key neurobiological findings brought about by the technique. The authors acknowledge funding for their general work from the Spanish Ministry of Science and Innovation (SAF-2017-83776-R, RYC-2014-15994 and IJCI-2017-32114), the Basque Government (PIBA19-0065 and PIBA-2020-1-0061), and the University of the Basque Country (GIU18/094 and INF19-29)

Background In recent years, several hundred autism spectrum disorder (ASD) implicated genes have been discovered impacting a wide range of molecular pathways. However, the molecular underpinning of ASD, particularly from the point of view of ‘brain to behaviour’ pathogenic mechanisms, remains largely unknown. Methods We undertook a study to investigate patterns of spatiotemporal and cell type expression of ASD-implicated genes by integrating large-scale brain single-cell transcriptomes (> million cells) and de novo loss-of-function (LOF) ASD variants (impacting 852 genes from 40,122 cases). Results We identified multiple single-cell clusters from three distinct developmental human brain regions (anterior cingulate cortex, middle temporal gyrus and primary visual cortex) that evidenced high evolutionary constraint through enrichment for brain critical exons and high pLI genes. These clusters also showed significant enrichment with ASD loss-of-function variant genes (p –11) that are transcriptionally highly active in prenatal brain regions (visual cortex and dorsolateral prefrontal cortex). Mapping ASD de novo LOF variant genes into large-scale human and mouse brain single-cell transcriptome analysis demonstrate enrichment of such genes into neuronal subtypes and are also enriched for subtype of non-neuronal glial cell types (astrocyte, p –11, oligodendrocyte, p –09). Conclusion Among the ASD genes enriched with pathogenic de novo LOF variants (i.e. KANK1, PLXNB1), a subgroup has restricted transcriptional regulation in non-neuronal cell types that are evolutionarily conserved. This association strongly suggests the involvement of subtype of non-neuronal glial cells in the pathogenesis of ASD and the need to explore other biological pathways for this disorder.

Kernicterus is a leading cause of neonatal death throughout the world, especially in low-middle-income countries. It is developed by an unconjugated hyperbilirubinemia in the blood and brain tissue, triggering pathological processes that spawn neurotoxicity and neurodegeneration. However, the biological mechanism (s) of bilirubin-induced neurotoxicity and Kernicterus development remain to be well elucidated. Likewise, a practical therapeutic approach for human Kernicterus has yet to be found. Undoubtedly, animal models of Kernicterus can be helpful in the identification of underlying biological processes of hyperbilirubinemia evolution to Kernicterus, as well as the evaluation of various treatments efficacy in preclinical studies. More importantly, establishing an animal model that can mimic the Kernicterus and its behavioral, neuro-histological, and hematological manifestations is a severe priority in preclinical studies. So far, several Kernicterus animal models have been established that could partially mimic one or more clinical and paraclinical signs of human Kernicterus. The present study aimed to review all methods modeling Kernicterus with a focus on their potentials and shortcomings and subsequently provide the optimal methods for an ideal Kernicterus animal model.

Peptide functionalized hyaluronic acid (HA CF) cross-linked by cucurbit[8]uril (CB[8]), a new class of drug-delivery reservoirs, is used to enable improved drug bioavailability for glioblastoma tumors in patient-derived xenograft (PDX) models. The mechanical and viscoelastic properties of native human and mouse tissues are measured over 8 h via oscillatory rheology under physiological conditions . Treatment with drug–loaded hydrogels allowed for a significant survival impact of 45 % (55.5–80.5 days). A relationship between the type of PDX tumor formed—a consequence of the heterogeneic nature of GB tumors—and changes in the initial survival is observed owing to greater local pressure from stiffer tumors. These biocompatible and tailorable materials warrant use as drug delivery reservoirs in PDX resection models, where the mechanical properties can be readily adjusted to match the stiffness of local tissue and thus have potential to improve the survival of GB patients.

Single-Molecule Localization Microscopy (SMLM) provides the ability to determine molecular organizations in cells at nanoscale resolution, but in complex biological tissues, where sample-induced aberrations hamper detection and localization, its application remains a challenge. Various adaptive optics approaches have been proposed to overcome these issues, but the exact performance of these methods has not been consistently established. Here we systematically compare the performance of existing methods using both simulations and experiments with standardized samples and find that they often provide limited correction or even introduce additional errors. Careful analysis of the reasons that underlie this limited success enabled us to develop an improved method, termed REALM (Robust and Effective Adaptive Optics in Localization Microscopy), which corrects aberrations of up to 1 rad RMS using 297 frames of blinking molecules to improve single-molecule localization. After its quantitative validation, we demonstrate that REALM enables to resolve the periodic organization of cytoskeletal spectrin of the axon initial segment even at 50 μm depth in brain tissue., It is difficult to apply SMLM to complex biological tissues. Here the authors report REALM, Robust and Effective Adaptive Optics in Localisation Microscopy, to improve SMLM in tissue and use this to resolve the organisation of spectrin in the axon initial segment in brain tissue.

Objective: Tanshinone IIA (TSN) and Tetramethylpyrazine (TMP) were combined in a composite, oil-in-water nanoemulsions (TSN/TMP O/W NEs) was prepared to prolong in vitro and vivo circulation time, and enhance the bioavailability of TSN. Material and methods: Physicochemical characterization of TSN/TMP O/W NEs was characterized systematically. The in vitro dissolution and in vivo pharmacokinetic experiments of TSN/TMP O/W NEs were also evaluated. Result: A formulation was optimized, yielding a 32.5 nm average particle size, an encapsulation efficiency of over 95 %, and were spherical in shape as shown by TEM. TSN/TMP O/W NEs were shown to extend the release and availability in vitro compared to raw compounds. In pharmacokinetic study, the AUC0→∞ and t1/2 of the TSN/TMP O/W NEs were 481.50 mg/L*min and 346.39 min higher than TSN solution, respectively. Brain tissue concentration of TSN was enhanced with TSN/TMP O/W NEs over raw TSN and even TSN O/W NEs. Conclusions: Therefore, nanoemulsions are an effective carrier to increase encapsulation efficiency of drugs, improve bioavailability and brain penetration for TSN – which is further enhanced by pairing with the co-delivery of TMP, providing a promising drug delivery.

Overexposure to manganese (Mn) is widely known to induce alpha-synuclein (α-Syn) oligomerization, which has been attributed to the oxidative damage of α-Syn protein. Trehalose has been shown to induce autophagy and serve as a chemical chaperone, but little information has been reported about its effect on Mn-induced α-Syn oligomerization. In this study, we investigate whether trehalose can effectively interfere with Mn-induced α-Syn oligomerization, using different concentrations of trehalose (2% and 4% (g/vol [mL])) in a mouse model of manganism. After 6 weeks of exposure to Mn, both oxidative stress and autophagy were activated and resulted in α-Syn oligomerization and neuronal cell damage in the mouse brain tissue. Our results also revealed that pretreatment with trehalose significantly reduced the oxidative damage to α-Syn protein and increased autophagy activation. These findings clearly demonstrated that trehalose can relieve Mn-induced α-Syn oligomerization and neuronal cell damage through its anti-oxidative and autophagy-inducing effects.

Vacuum forced tissue impregnation is the signature step of the plastination process. It requires polymers with a low vapour pressure, low viscosity and a long pot life. Plastination polymers are a compromise between these mandatory requirements on the one hand and various secondary demands such as specimen stability, resistance to UV light and defined light refraction index on the other hand. Combining different polymers in one plastinate instead of using one plastination polymer alone can result in improved specimens for exhibitions and teaching including hands-on use for students. The aim of this study was to assess the range of possible sheet plastinate modifications and how the resulting multiple polymer plastinates can fulfil the secondary requirements of user-friendly plastinates. Adding sub-steps of tissue impregnation and processing to the standard plastination protocol allows combining different polymer properties including the use of substances which are not suitable for conventional plastination as such but have better properties than plastination polymers. Advantages like resistance to UV light and mechanical stability can be combined and characteristic disadvantages of plastination polymers can be avoided. Acrylic protection layers (APL) offer a complete protection of the specimen in combination with advanced presentation possibilities and the option of completely refurbishing valuable specimens. Hybrid sheet plastinates provide lower preparation cost and polymer-tissue interactions for an improved visualization of fat, nerves and brain tissue. Selective impregnation is a promising approach for the clearer differentiation of various structures and tissue types.

The early noninvasive diagnosis of Alzheimer's disease targeted β-amyloid (Aβ) plaques or Tau tangles is a major challenge because of the coshared β-sheet structure of the target. In contrast to tailoring probes to specific amyloids, here, we showed that near-infrared (NIR) environment-sensitive probe 18 could fluorescently discriminate Aβ and Tau from artificial aggregates to pathological change in the brain tissue. The biological evaluation demonstrated that the substantial fluorescence enhancement, large blueshift in the emission upon interactions with the aggregates, and the high binding affinity significantly contributed to the fluorescent discrimination. A simplified Ooshika-Lippert-Mataga equation provided an effective means of correlating 18 with the static relative permittivity (e0) of proteins, elucidating the origin of the distinction capabilities, and quantitatively estimating the dielectric properties of proteins. Moreover, 18 possessed high bioavailability, including sufficient blood-brain barrier penetration, in vivo NIR imaging, and ex vivo histology in living mice.