Immunoregulatory and neutrophil-like monocyte subsets with distinct single-cell transcriptomic signatures emerge following brain injury.

Monocytes represent key cellular elements that contribute to the neurological sequela following brain injury. The current study reveals that trauma induces the augmented release of a transcriptionally distinct CD115+/Ly6Chi monocyte population into the circulation of mice pre-exposed to clodronate depletion conditions. This phenomenon correlates with tissue protection, blood-brain barrier stability, and cerebral blood flow improvement. Uniquely, this shifted the innate immune cell profile in the cortical milieu and reduced the expression of pro-inflammatory Il6, IL1r1, MCP-1, Cxcl1, and Ccl3 cytokines. Monocytes that emerged under these conditions displayed a morphological and gene profile consistent with a subset commonly seen during emergency monopoiesis. Single-cell RNA sequencing delineated distinct clusters of monocytes and revealed a key transcriptional signature of Ly6Chi monocytes enriched for Apoe and chitinase-like protein 3 (Chil3/Ym1), commonly expressed in pro-resolving immunoregulatory monocytes, as well as granule genes Elane, Prtn3, MPO, and Ctsg unique to neutrophil-like monocytes. The predominate shift in cell clusters included subsets with low expression of transcription factors involved in monocyte conversion, Pou2f2, Na4a1, and a robust enrichment of genes in the oxidative phosphorylation pathway which favors an anti-inflammatory phenotype. Transfer of this monocyte assemblage into brain-injured recipient mice demonstrated their direct role in neuroprotection. These findings reveal a multifaceted innate immune response to brain injury and suggest targeting surrogate monocyte subsets may foster tissue protection in the brain.

Lifelong Chronic Sleep Disruption in a Mouse Model of Traumatic Brain Injury.

Chronic sleep/wake disturbances (SWDs) are strongly associated with traumatic brain injury (TBI) in patients and are being increasingly recognized. However, the underlying mechanisms are largely understudied and there is an urgent need for animal models of lifelong SWDs. The objective of this study was to develop a chronic TBI rodent model and investigate the lifelong chronic effect of TBI on sleep/wake behavior. We performed repetitive midline fluid percussion injury (rmFPI) in 4-month-old mice and monitored their sleep/wake behavior using the non-invasive PiezoSleep system. Sleep/wake states were recorded before injury (baseline) and then monthly thereafter. We found that TBI mice displayed a significant decrease in sleep duration in both the light and dark phases, beginning at 3 months post-TBI and continuing throughout the study. Consistent with the sleep phenotype, these TBI mice showed circadian locomotor activity phenotypes and exhibited reduced anxiety-like behavior. TBI mice also gained less weight, and had less lean mass and total body water content, compared to sham controls. Further, TBI mice showed extensive brain tissue loss and increased glial fibrillary acidic protein and ionized calcium-binding adaptor molecule 1 levels in the hypothalamus and vicinity of the injury, indicative of chronic neuropathology. In summary, our study identified a critical time window of TBI pathology and associated circadian and sleep/wake phenotypes. Future studies should leverage this mouse model to investigate the molecular mechanisms underlying the chronic sleep/wake phenotypes post-TBI early in life.

Morphological evaluation of the feline placenta correlates with gene expression of vascular growth factors and receptors†.

Placental angiogenesis is critical for normal development. Angiogenic factors and their receptors are key regulators of this process. Dysregulated placental vascular development is associated with pregnancy complications. Despite their importance, vascular growth factor expression has not been thoroughly correlated with placental morphologic development across gestation in cats. We postulate that changes in placental vessel morphology can be appreciated as consequences of dynamic expression of angiogenic signaling agents. Here, we characterized changes in placental morphology alongside expression analysis of angiogenic factor splice variants and receptors throughout pregnancy in domestic shorthair cats. We observed increased vascular and lamellar density in the lamellar zone during mid-pregnancy. Immunohistochemical analysis localized the vascular endothelial growth factor A (VEGF-A) receptor KDR to endothelial cells of the maternal and fetal microvasculatures. PlGF and its principal receptor Flt-1 were localized to the trophoblasts and fetal vasculature. VEGF-A was found in trophoblast cells and associated with endothelial cells. We detected expression of two Plgf splice variants and four Vegf-a variants. Quantitative real-time polymerase chain reaction analysis showed upregulation of mRNAs encoding pan Vegf-a and all Vegf-a splice forms at gestational days 30-35. Vegf-A showed a marked relative increase in expression during mid-pregnancy, consistent with the pro-angiogenic changes seen in the lamellar zone at days 30-35. Flt-1 was upregulated during late pregnancy. Plgf variants showed stable expression during the first two-thirds of pregnancy, followed by a marked increase toward term. These findings revealed specific spatiotemporal expression patterns of VEGF-A family members consistent with pivotal roles during normal placental development.

Sleep Disruption in a Mouse Model of Chronic Traumatic Brain Injury.

Chronic sleep/wake disturbances are strongly associated with traumatic brain injury (TBI) in patients and are being increasingly recognized. However, the underlying mechanisms are largely understudied and there is an urgent need for animal models of lifelong sleep/wake disturbances. The objective of this study was to develop a chronic TBI rodent model and investigate the lifelong chronic effect of TBI on sleep/wake behavior. We performed repetitive midline fluid percussion injury (rmFPI) in four months old mice and monitored their sleep/wake behavior using the non-invasive PiezoSleep system. The sleep/wake states were recorded before injury (baseline) and then monthly thereafter. We found that TBI mice displayed a significant decrease in sleep duration in both the light and dark phases, beginning at three months post-TBI and continuing throughout the study. Consistent with the sleep phenotype, these TBI mice showed circadian locomotor activity phenotypes and exhibited reduced anxiety-like behavior. TBI mice also gained less weight, and had less lean mass and total body water content, compared to sham controls. Furthermore, TBI mice showed extensive brain tissue loss and increased GFAP and IBA1 levels in the hypothalamus and the vicinity of the injury, indicative of chronic neuropathology. In summary, our study identified a critical time window of TBI pathology and associated circadian and sleep/wake phenotypes. Future studies should leverage this mouse model to investigate the molecular mechanisms underlying the chronic sleep/wake phenotypes following TBI early in life.

Remdesivir increases mtDNA copy number causing mild alterations to oxidative phosphorylation.

SARS-CoV-2 causes the severe respiratory disease COVID-19. Remdesivir (RDV) was the first fast-tracked FDA approved treatment drug for COVID-19. RDV acts as an antiviral ribonucleoside (adenosine) analogue that becomes active once it accumulates intracellularly. It then diffuses into the host cell and terminates viral RNA transcription. Previous studies have shown that certain nucleoside analogues unintentionally inhibit mitochondrial RNA or DNA polymerases or cause mutational changes to mitochondrial DNA (mtDNA). These past findings on the mitochondrial toxicity of ribonucleoside analogues motivated us to investigate what effects RDV may have on mitochondrial function. Using in vitro and in vivo rodent models treated with RDV, we observed increases in mtDNA copy number in Mv1Lu cells (35.26% increase ± 11.33%) and liver (100.27% increase ± 32.73%) upon treatment. However, these increases only resulted in mild changes to mitochondrial function. Surprisingly, skeletal muscle and heart were extremely resistant to RDV treatment, tissues that have preferentially been affected by other nucleoside analogues. Although our data suggest that RDV does not greatly impact mitochondrial function, these data are insightful for the treatment of RDV for individuals with mitochondrial disease.

Generation and Observation of Long-Lasting and Self-Sustaining Marangoni Flow.

When solute molecules in a liquid evaporate at the surface, concentration gradients can lead to surface tension gradients and provoke fluid convection at the interface, a phenomenon commonly known as the Marangoni effect. Here, we demonstrate that minute quantities of ethanol in concentrated sodium hydroxide solution can induce pronounced and long-lasting Marangoni flow upon evaporation at room temperature. By employing particle image velocimetry and gravimetric analysis, we show that the mean interfacial speed of the evaporating solution sensitively increases with the evaporation rate for ethanol concentrations lower than 0.5 mol %. Placing impermeable objects near the liquid-gas interface enforces steady concentration gradients, thereby promoting the formation of stationary flows. This allows for contact-free control of the flow pattern as well as its modification by altering the objects shape. Analysis of bulk flows reveals that the energy of evaporation in the case of stationary flows is converted to kinetic fluid energy with high efficiency, but reducing the sodium hydroxide concentration drastically suppresses the observed effect to the point where flows become entirely absent. Investigating the properties of concentrated sodium hydroxide solution suggests that ethanol dissolution in the bulk is strongly limited. At the surface, however, the co-solvent is efficiently stored, enabling rapid adsorption or desorption of the alcohol depending on its concentration in the adjacent gas phase. This facilitates the generation of large surface tension gradients and, in combination with the perpetual replenishment of the surface ethanol concentration by bulk convection, to the generation of long-lasting, self-sustaining flows.

Nucleation of Porous Crystals from Ion-Paired Prenucleation Clusters.

Current nucleation models propose manifold options for the formation of crystalline materials. Exploring and distinguishing between different crystallization pathways on the molecular level however remain a challenge, especially for complex porous materials. These usually consist of large unit cells with an ordered framework and pore components and often nucleate in complex, multiphasic synthesis media, restricting in-depth characterization. This work shows how aluminosilicate speciation during crystallization can be documented in detail in monophasic hydrated silicate ionic liquids (HSILs). The observations reveal that zeolites can form via supramolecular organization of ion-paired prenucleation clusters, consisting of aluminosilicate anions, ion-paired to alkali cations, and imply that zeolite crystallization from HSILs can be described within the spectrum of modern nucleation theory.

A zeolite crystallisation model confirmed by in situ observation.

Probing nucleation and growth of porous crystals at a molecular level remains a cumbersome experimental endeavour due to the complexity of the synthesis media involved. In particular, the study of zeolite formation is hindered as these typically form in multiphasic synthesis media, which restricts experimental access to crystallisation processes. Zeolite formation from single phasic hydrated silicate ionic liquids (HSiL) opens new possibilities. In this work, HSiL zeolite crystallisation is investigated in situ using a specifically designed conductivity measurement set-up yielding access to crystallisation kinetics. Based on the conductivity data and final yields, a crystallisation model explaining the results based on a surface growth mechanism was derived. The excellent agreement between experiment and theory indicates zeolite crystallisation from highly ionic media proceeds via a multi-step mechanism, involving an initial reversible surface condensation of a growth unit, followed by incorporation of that unit into the growing crystal. The first step is governed by the liquid phase concentration and surface energy, while the final step shows a correlation to the mobility of the cation involved.

Moving Electrode Impedance Spectroscopy for Accurate Conductivity Measurements of Corrosive Ionic Media.

A measurement cell for the use of accurate conductivity measurements of corrosive ionic media is presented. Based on the concept of moving electrode electrochemical impedance spectroscopy, exceptional measurement accuracy is achieved in a large conductivity range. Extensive testing with corrosive ionic media demonstrated the robust operation of the cell under harsh chemical conditions, up to temperatures of 130 °C. The novel design allows monitoring small conductivity changes during chemical reactions in ionic media, for instance, zeolite formation from hydrated ionic liquids.

TIS - Talking in Symbols. Development of a Tool for Nonverbal Communication after Language Barriers in Pediatric Oncology.

Language barriers have been reported to have a detrimental effect on various outcomes in paediatric care, such as therapy adherence, and may even cause medical treatment errors. To address this issue, we developed a set of 63 cards with which a wide range of specific messages can be conveyed nonverbally in a clinical context. The conceptualization of the tool involved multiple phases. In Study 1, we held a workshop with 11 children and adolescents between 8 and 19 years that had received treatment for oncological conditions to gain an understanding of the specific challenges. In Study 2, we presented a first prototype to 3 children and 14 adults; participants were asked to rate the cards on multiple dimensions. Based on information from the previous trials, we developed a second prototype and asked 10 children and 7 adults to rate the cards on multiple dimensions. In this multidisciplinary approach in addition to our experts of clinical psychology we involved patient advocators and graphic designers in the process to achieve high feasibility and comprehensibility; based on the workshop, expert consensus surveys, data gathered in evaluation, all prototypes and the final card set were developed in close collaboration. Participants had little difficulty interpreting the cards and rated the information content as adequate. Importantly, a majority of participants indicated that they would keep using the tool during their stay at the hospital. Overall, the evaluation implied high acceptance and usability. The final card set is a promising communication tool in clinical paediatric settings with various language barriers. Further research should address how patient outcomes are impacted by using the tool.

Dilated cardiomyopathy with endocardial fibroelastosis in a juvenile Pallas cat.

Dilated cardiomyopathy (DCM) is a myocardial disease characterized by ventricular chamber dilation associated with systolic myocardial dysfunction in the absence of other cardiac lesions. DCM occasionally develops in conjunction with proliferation of fibroelastic fibers in the endocardium, producing endocardial fibroelastosis (EFE). Although early reports describe EFE as a primary disease, evidence now suggests that EFE may develop as a response to myocardial dysfunction. Echocardiographic evaluation of a 4-wk-old Pallas cat ( Otocolobus manul) with respiratory distress revealed enlargement of both atria, enlarged end-systolic left ventricular dimension, and left ventricular dilation. DCM was diagnosed, and the cat was euthanized, given the poor prognosis. Postmortem examination revealed pericardial effusion and biventricular and biatrial enlargement. The interventricular septum and free walls of ventricles were thin. Histologically, the endocardium of the left and right ventricles was diffusely thickened; Verhoeff-Van Gieson staining of the left ventricular endocardium revealed a moderate amount of endocardial accumulation of elastin and collagen. These fibers were more prominent in papillary muscles and around coronary blood vessels. Based on these findings, we diagnosed DCM with EFE. Cardiac diseases are rarely diagnosed in wild felids.

Effects of Complement C4 Gene Copy Number Variations, Size Dichotomy, and C4A Deficiency on Genetic Risk and Clinical Presentation of Systemic Lupus Erythematosus in East Asian Populations.

OBJECTIVE: Human complement C4 is complex, with multiple layers of diversity. The aims of this study were to elucidate the copy number variations (CNVs) of C4A and C4B in relation to disease risk in systemic lupus erythematosus (SLE), and to compare the basis of race-specific C4A deficiency between East Asians and individuals of European descent. METHODS: The East Asian study population included 999 SLE patients and 1,347 healthy subjects. Variations in gene copy numbers (GCNs) of total C4, C4A, and C4B, as well as C4-Long and C4-Short genes, were determined and validated using independent genotyping technologies. Genomic regions with C4B96 were investigated to determine the basis of the most basic C4B protein occurring concurrently with C4A deficiency. RESULTS: In East Asians, high GCNs of total C4 and C4A were strongly protective against SLE, whereas low and medium GCNs of total C4 and C4A, and the absence of C4-Short genes, were risk factors for SLE. Homozygous C4A deficiency was infrequent in East Asian subjects, but had an odds ratio (OR) of 12.4 (P = 0.0015) for SLE disease susceptibility. Low serum complement levels were strongly associated with low GCNs of total C4 (OR 3.19, P = 7.3 × 10(-7) ) and C4B (OR 2.53, P = 2.5 × 10(-5) ). Patients with low serum complement levels had high frequencies of anti-double-stranded DNA antibodies (OR 4.96, P = 9.7 × 10(-17) ), hemolytic anemia (OR 3.89, P = 3.6 × 10(-10) ), and renal disease (OR 2.18, P = 8.5 × 10(-6) ). The monomodular-Short haplotype found to be prevalent in European Americans with C4A deficiency, which was in linkage disequilibrium with HLA-DRB1*0301, was scarce in East Asians. Instead, most East Asian subjects with C4A deficiency were found to have a recombinant haplotype with bimodular C4-Long and C4-Short genes, encoding C4B1 and C4B96, which was linked to HLA-DRB1*1501. DNA sequencing revealed an E920K polymorphism in C4B96. CONCLUSION: C4 CNVs and deficiency of C4A both play an important role in the risk and manifestations of SLE in East Asian and European populations.

Does Solution Viscosity Scale the Rate of Aggregation of Folded Proteins?

Viscosity effects on the kinetics of complex solution processes have proven hard to predict. To test the viscosity effects on protein aggregation, we use the crystallization of the protein glucose isomerase (gluci) as a model and employ scanning confocal and atomic force microscopies at molecular resolution, dynamic and static light scattering, and rheometry. We add glycerol to vary solvent viscosity and demonstrate that glycerol effects on the activation barrier for attachment of molecules to the crystal growth sites are minimal. We separate the effects of glycerol on crystallization thermodynamics from those on the rate constant for molecular attachment. We establish that the rate constant is proportional to the reciprocal viscosity and to the protein diffusivity. This finding refutes the prevailing crystal growth paradigm and illustrates the application of fundamental kinetics laws to solution crystallization.

Plasmonic crystal defect nanolaser.

Surface plasmons are widely interesting due to their ability to probe nanoscale dimensions. To create coherent plasmons, we demonstrate a nanolaser based on a plasmonic bandgap defect state inside a surface plasmonic crystal. A one-dimensional semiconductor-based plasmonic crystal is engineered to have stopbands in which surface plasmons are prohibited from travelling in the crystalline structure. We then confine surface plasmons using a three-hole defect in the periodic structure. Using conventional III-V semiconductors, we achieve lasing in mode volumes as small as V(eff) = 0.3(λ0/n)³ at λ0 = 1342 nm, which is 10 times smaller than similar modes in photonic crystals of the same size. This demonstration should pave the way for achieving engineered nanolasers with deep-subwavelength mode volumes and attractive nanophotonics integration capabilities while enabling the use of plasmonic crystals as an attractive platform for designing plasmons.

Viscosity sensing in heated alkaline zeolite synthesis media.

A quartz disc resonator operating in thickness shear mode was used for the in situ monitoring of the viscosity during zeolite crystal formation.

Enhanced modulation bandwidth of nanocavity light emitting devices.

We show that the direct modulation bandwidth of nano-cavity light emitting devices (nLEDs) can greatly exceed that of any laser. By performing a detailed analysis, we show that the modulation bandwidth can be increased by the Purcell effect, but that this enhancement occurs only when the device is biased below the lasing threshold. The maximum bandwidth is shown to be inversely proportional to the square root of the modal volume, with sub-wavelength cavities necessary to exceed conventional laser speeds.

Great genotypic and phenotypic diversities associated with copy-number variations of complement C4 and RP-C4-CYP21-TNX (RCCX) modules: a comparison of Asian-Indian and European American populations.

Inter-individual gene copy-number variations (CNVs) probably afford human populations the flexibility to respond to a variety of environmental challenges, but also lead to differential disease predispositions. We investigated gene CNVs for complement component C4 and steroid 21-hydroxylase from the RP-C4-CYP21-TNX (RCCX) modules located in the major histocompatibility complex among healthy Asian-Indian Americans (AIA) and compared them to European Americans. A combination of definitive techniques that yielded cross-confirmatory results was used. The medium gene copy-numbers for C4 and its isotypes, acidic C4A and basic C4B, were 4, 2 and 2, respectively, but their frequencies were only 53-56%. The distribution patterns for total C4 and C4A are skewed towards the high copy-number side. For example, the frequency of AIA-subjects with three copies of C4A (30.7%) was 3.92-fold of those with a single copy (7.83%). The monomodular-short haplotype with a single C4B gene and the absence of C4A, which is in linkage-disequilibrium with HLA DRB1*0301 in Europeans and a strong risk factor for autoimmune diseases, has a frequency of 0.012 in AIA but 0.106 among healthy European Americans (p=6.6x10(-8)). The copy-number and the size of C4 genes strongly determine the plasma C4 protein concentrations. Parallel variations in copy-numbers of CYP21A (CYP21A1P) and TNXA with total C4 were also observed. Notably, 13.1% of AIA-subjects had three copies of the functional CYP21B, which were likely generated by recombinations between monomodular and bimodular RCCX haplotypes. The high copy-numbers of C4 and the high frequency of RCCX recombinants offer important insights to the prevalence of autoimmune and genetic diseases.

Strong optical injection-locked semiconductor lasers demonstrating > 100-GHz resonance frequencies and 80-GHz intrinsic bandwidths.

By using strong optical injection locking, we report resonance frequency enhancement in excess of 100 GHz in semiconductor lasers. We demonstrate this enhancement in both distributed feedback (DFB) lasers and vertical-cavity surface-emitting lasers (VCSELs), showing the broad applicability of the technique and that the coupling Q is the figure-of-merit for resonance frequency enhancement. We have also identified the key factors that cause low-frequency roll-off in injection-locked lasers. By increasing the slave laser's DC current bias, we have achieved a record intrinsic 3-dB bandwidth of 80 GHz in VCSELs.

Scaling of resonance frequency for strong injection-locked lasers.

It has been shown that strong optical injection locking can significantly enhance the resonance frequency of semiconductor lasers. In this Letter, we describe the trade-off between the maximum resonance frequency enhancement and the quality factor (Q) of the lossless laser cavity and show that the time-bandwidth product (product of photon lifetime and maximum resonance frequency) is equal to one half the square root of the external power injection ratio. The theoretical model agrees well with our experimental data.

Frequency of carriers of 8.1 ancestral haplotype and its fragments in two Caucasian populations.

Within the human MHC region larger stretches of conserved DNA, called conserved ancestral haplotypes exist. However, many MHC haplotypes contain only fragments of an ancestral haplotype. Little is known, however, on relative distribution of the ancestral haplotypes to their fragments. Therefore we determined the frequency of carriers of the whole ancestral haplotype 8.1 (AH8.1) and its fragments in 127 healthy Hungarian people, 101 healthy Ohioian females, and in nine Hungarian families. The HLA-DQ2, HLA-DR3(17), RAGE -429C allele, the mono-S-C4B genotype, the HSP70-2 1267G allele and the TNF -308A (TNF2) allele were used as markers of the AH8.1. Frequency of carriers of the whole AH8.1 and its fragments was similar in the both populations. 18% of the subjects carried the whole AH8.1 in at least one chromosome, while 17-20%, 36-39%, and 24-29%, respectively carried two or three constituents of the haplotype, only one constituent or none of them. Similar results were obtained in the family study. In addition, marked differences were found in the relationship of the constituents' alleles to the whole AH8.1. In both populations, 29%, 50-59%, 52-56% and 76-96%, respectively of the carriers of HSP70-2 1267G, RAGE-429C, TNF2, and mono-S carriers carried the whole 8.1 haplotype. These findings may have important implications for studies of the disease associations with different MHC ancestral haplotypes.