The calcium transporter ANNEXIN1 mediates cold-induced calcium signaling and freezing tolerance in plants.

The transient elevation of cytosolic free calcium concentration ([Ca2+ ]cyt ) induced by cold stress is a well-established phenomenon; however, the underlying mechanism remains elusive. Here, we report that the Ca2+ -permeable transporter ANNEXIN1 (AtANN1) mediates cold-triggered Ca2+ influx and freezing tolerance in Arabidopsis thaliana. The loss of function of AtANN1 substantially impaired freezing tolerance, reducing the cold-induced [Ca2+ ]cyt increase and upregulation of the cold-responsive CBF and COR genes. Further analysis showed that the OST1/SnRK2.6 kinase interacted with and phosphorylated AtANN1, which consequently enhanced its Ca2+ transport activity, thereby potentiating Ca2+ signaling. Consistent with these results and freezing sensitivity of ost1 mutants, the cold-induced [Ca2+ ]cyt elevation in the ost1-3 mutant was reduced. Genetic analysis indicated that AtANN1 acts downstream of OST1 in responses to cold stress. Our data thus uncover a cascade linking OST1-AtANN1 to cold-induced Ca2+ signal generation, which activates the cold response and consequently enhances freezing tolerance in Arabidopsis.

Enhancing diagnostic precision for acute chest syndrome in sickle cell disease: insights from dual-energy CT lung perfusion mapping.

PURPOSE: Acute chest syndrome (ACS) is secondary to occlusion of the pulmonary vasculature and a potentially life-threatening complication of sickle cell disease (SCD). Dual-energy CT (DECT) iodine perfusion map reconstructions can provide a method to visualize and quantify the extent of pulmonary microthrombi. METHODS: A total of 102 patients with sickle cell disease who underwent DECT CTPA with perfusion were retrospectively identified. The presence or absence of airspace opacities, segmental perfusion defects, and acute or chronic pulmonary emboli was noted. The number of segmental perfusion defects between patients with and without acute chest syndrome was compared. Sub-analyses were performed to investigate robustness. RESULTS: Of the 102 patients, 68 were clinically determined to not have ACS and 34 were determined to have ACS by clinical criteria. Of the patients with ACS, 82.4% were found to have perfusion defects with a median of 2 perfusion defects per patient. The presence of any or new perfusion defects was significantly associated with the diagnosis of ACS (P = 0.005 and < 0.001, respectively). Excluding patients with pulmonary embolism, 79% of patients with ACS had old or new perfusion defects, and the specificity for new perfusion defects was 87%, higher than consolidation/ground glass opacities (80%). CONCLUSION: DECT iodine map has the capability to depict microthrombi as perfusion defects. The presence of segmental perfusion defects on dual-energy CT maps was found to be associated with ACS with potential for improved specificity and reclassification.

Multi-Omics Characterization of Colon Mucosa and Submucosa/Wall from Crohn's Disease Patients.

Crohn's disease (CD) is a subtype of inflammatory bowel disease (IBD) characterized by transmural disease. The concept of transmural healing (TH) has been proposed as an indicator of deep clinical remission of CD and as a predictor of favorable treatment endpoints. Understanding the pathophysiology involved in transmural disease is critical to achieving these endpoints. However, most studies have focused on the intestinal mucosa, overlooking the contribution of the intestinal wall in Crohn's disease. Multi-omics approaches have provided new avenues for exploring the pathogenesis of Crohn's disease and identifying potential biomarkers. We aimed to use transcriptomic and proteomic technologies to compare immune and mesenchymal cell profiles and pathways in the mucosal and submucosa/wall compartments to better understand chronic refractory disease elements to achieve transmural healing. The results revealed similarities and differences in gene and protein expression profiles, metabolic mechanisms, and immune and non-immune pathways between these two compartments. Additionally, the identification of protein isoforms highlights the complex molecular mechanisms underlying this disease, such as decreased RTN4 isoforms (RTN4B2 and RTN4C) in the submucosa/wall, which may be related to the dysregulation of enteric neural processes. These findings have the potential to inform the development of novel therapeutic strategies to achieve TH.

Optimisation of virtual monoenergetic reconstructions for the diagnosis of pulmonary embolism using photon-counting detector computed tomography angiography.

Purpose: Computed tomography (CT) pulmonary angiography is considered the gold standard for pulmonary embolism (PE) diagnosis, relying on the discrimination between contrast and embolus. Photon-counting detector CT (PCD-CT) generates monoenergetic reconstructions through energy-resolved detection. Virtual monoenergetic images (VMI) at low keV can be used to improve pulmonary artery opacification. While studies have assessed VMI for PE diagnosis on dual-energy CT (DECT), there is a lack of literature on optimal settings for PCD-CT-PE reconstructions, warranting further investigation. Material and methods: Twenty-five sequential patients who underwent PCD-CT pulmonary angiography for suspicion of acute PE were retrospectively included in this study. Quantitative metrics including signal-to-noise ratio (SNR) and contrast-to-noise (CNR) ratio were calculated for 4 VMI values (40, 60, 80, and 100 keV). Qualitative measures of diagnostic quality were obtained for proximal to distal pulmonary artery branches by 2 cardiothoracic radiologists using a 5-point modified Likert scale. Results: SNR and CNR were highest for the 40 keV VMI (49.3 ± 22.2 and 48.2 ± 22.1, respectively) and were inversely related to monoenergetic keV. Qualitatively, 40 and 60 keV both exhibited excellent diagnostic quality (mean main pulmonary artery: 5.0 ± 0 and 5.0 ± 0; subsegmental pulmonary arteries 4.9 ± 0.1 and 4.9 ± 0.1, respectively) while distal segments at high (80-100) keVs had worse quality. Conclusions: 40 keV was the best individual VMI for the detection of pulmonary embolism by quantitative metrics. Qualitatively, 40-60 keV reconstructions may be used without a significant decrease in subjective quality. VMIs at higher keV lead to reduced opacification of the distal pulmonary arteries, resulting in decreased image quality.

Cell wall fucosylation in Arabidopsis influences control of leaf water loss and alters stomatal development and mechanical properties.

The Arabidopsis sensitive-to-freezing8 (sfr8) mutant exhibits reduced cell wall (CW) fucose levels and compromised freezing tolerance. To examine whether CW fucosylation also affects the response to desiccation, we tested the effect of leaf excision in sfr8 and the allelic mutant mur1-1. Leaf water loss was strikingly higher than in the wild type in these, but not other, fucosylation mutants. We hypothesized that reduced fucosylation in guard cell (GC) walls might limit stomatal closure through altering mechanical properties. Multifrequency atomic force microscopy (AFM) measurements revealed a reduced elastic modulus (E'), representing reduced stiffness, in sfr8 GC walls. Interestingly, however, we discovered a compensatory mechanism whereby a concomitant reduction in the storage modulus (E'') maintained a wild-type viscoelastic time response (tau) in sfr8. Stomata in intact leaf discs of sfr8 responded normally to a closure stimulus, abscisic acid, suggesting that the time response may relate more to closure properties than stiffness does. sfr8 stomatal pore complexes were larger than those of the wild type, and GCs lacked a fully developed cuticular ledge, both potential contributors to the greater leaf water loss in sfr8. We present data that indicate that fucosylation-dependent dimerization of the CW pectic domain rhamnogalacturonan-II may be essential for normal cuticular ledge development and leaf water retention.

Rapid and Dynamic Alternative Splicing Impacts the Arabidopsis Cold Response Transcriptome.

Plants have adapted to tolerate and survive constantly changing environmental conditions by reprogramming gene expression The dynamics of the contribution of alternative splicing (AS) to stress responses are unknown. RNA-sequencing of a time-series of Arabidopsis thaliana plants exposed to cold determines the timing of significant AS changes. This shows a massive and rapid AS response with coincident waves of transcriptional and AS activity occurring in the first few hours of temperature reduction and further AS throughout the cold. In particular, hundreds of genes showed changes in expression due to rapidly occurring AS in response to cold ("early AS" genes); these included numerous novel cold-responsive transcription factors and splicing factors/RNA binding proteins regulated only by AS. The speed and sensitivity to small temperature changes of AS of some of these genes suggest that fine-tuning expression via AS pathways contributes to the thermo-plasticity of expression. Four early AS splicing regulatory genes have been shown previously to be required for freezing tolerance and acclimation; we provide evidence of a fifth gene, U2B"-LIKE Such factors likely drive cascades of AS of downstream genes that, alongside transcription, modulate transcriptome reprogramming that together govern the physiological and survival responses of plants to low temperature.

MUR1-mediated cell-wall fucosylation is required for freezing tolerance in Arabidopsis thaliana.

Forward genetic screens play a key role in the identification of genes contributing to plant stress tolerance. Using a screen for freezing sensitivity, we have identified a novel freezing tolerance gene, SENSITIVE-TO-FREEZING8, in Arabidopsis thaliana. We identified SFR8 using recombination-based mapping and whole-genome sequencing. As SFR8 was predicted to have an effect on cell wall composition, we used GC-MS and polyacrylamide gel electrophoresis to measure cell-wall fucose and boron (B)-dependent dimerization of the cell-wall pectic domain rhamnogalacturonan II (RGII) in planta. After treatments to promote borate-bridging of RGII, we assessed freeze-induced damage in wild-type and sfr8 plants by measuring electrolyte leakage from freeze-thawed leaf discs. We mapped the sfr8 mutation to MUR1, a gene encoding the fucose biosynthetic enzyme GDP-d-mannose-4,6-dehydratase. sfr8 cell walls exhibited low cell-wall fucose levels and reduced RGII bridging. Freezing sensitivity of sfr8 mutants was ameliorated by B supplementation, which can restore RGII dimerization. B transport mutants with reduced RGII dimerization were also freezing-sensitive. Our research identifies a role for the structure and composition of the plant primary cell wall in determining basal plant freezing tolerance and highlights the specific importance of fucosylation, most likely through its effect on the ability of RGII pectin to dimerize.

Identification of MEDIATOR16 as the Arabidopsis COBRA suppressor MONGOOSE1.

We performed a screen for genetic suppressors of cobra, an Arabidopsis mutant with defects in cellulose formation and an increased ratio of unesterified/esterified pectin. We identified a suppressor named mongoose1 (mon1) that suppressed the growth defects of cobra, partially restored cellulose levels, and restored the esterification ratio of pectin to wild-type levels. mon1 was mapped to the MEDIATOR16 (MED16) locus, a tail mediator subunit, also known as SENSITIVE TO FREEZING6 (SFR6). When separated from the cobra mutation, mutations in MED16 caused resistance to cellulose biosynthesis inhibitors, consistent with their ability to suppress the cobra cellulose deficiency. Transcriptome analysis revealed that a number of cell wall genes are misregulated in med16 mutants. Two of these genes encode pectin methylesterase inhibitors, which, when ectopically expressed, partially suppressed the cobra phenotype. This suggests that cellulose biosynthesis can be affected by the esterification levels of pectin, possibly through modifying cell wall integrity or the interaction of pectin and cellulose.

The Arabidopsis mediator complex subunits MED16, MED14, and MED2 regulate mediator and RNA polymerase II recruitment to CBF-responsive cold-regulated genes.

The Mediator16 (MED16; formerly termed SENSITIVE TO FREEZING6 [SFR6]) subunit of the plant Mediator transcriptional coactivator complex regulates cold-responsive gene expression in Arabidopsis thaliana, acting downstream of the C-repeat binding factor (CBF) transcription factors to recruit the core Mediator complex to cold-regulated genes. Here, we use loss-of-function mutants to show that RNA polymerase II recruitment to CBF-responsive cold-regulated genes requires MED16, MED2, and MED14 subunits. Transcription of genes known to be regulated via CBFs binding to the C-repeat motif/drought-responsive element promoter motif requires all three Mediator subunits, as does cold acclimation-induced freezing tolerance. In addition, these three subunits are required for low temperature-induced expression of some other, but not all, cold-responsive genes, including genes that are not known targets of CBFs. Genes inducible by darkness also required MED16 but required a different combination of Mediator subunits for their expression than the genes induced by cold. Together, our data illustrate that plants control transcription of specific genes through the action of subsets of Mediator subunits; the specific combination defined by the nature of the stimulus but also by the identity of the gene induced.

The effects of an ActRIIb receptor Fc fusion protein ligand trap in juvenile simian immunodeficiency virus-infected rhesus macaques.

There are no approved therapies for muscle wasting in children infected with human immunodeficiency virus (HIV), which portends poor disease outcomes. To determine whether a soluble ActRIIb receptor Fc fusion protein (ActRIIB.Fc), a ligand trap for TGF-ß/activin family members including myostatin, can prevent or restore loss of lean body mass and body weight in simian immunodeficiency virus (SIV)-infected juvenile rhesus macaques (Macaca mulatta). Fourteen pair-housed, juvenile male rhesus macaques were inoculated with SIVmac239 and, 4 wk postinoculation (WPI) treated with intramuscular injections of 10 mg ⋅ kg(-1) ⋅ wk(-1) ActRIIB.Fc or saline placebo. Body weight, lean body mass, SIV titers, and somatometric measurements were assessed monthly for 16 wk. Age-matched SIV-infected rhesus macaques were injected with saline. Intervention groups did not differ at baseline. Gains in lean mass were significantly greater in the ActRIIB.Fc group than in the placebo group (P < 0.001). Administration of ActRIIB.Fc was associated with greater gains in body weight (P = 0.01) and upper arm circumference than placebo. Serum CD4(+) T-lymphocyte counts and SIV copy numbers did not differ between groups. Administration of ActRIIB.Fc was associated with higher muscle expression of myostatin than placebo. ActRIIB.Fc effectively blocked and reversed loss of body weight, lean mass, and fat mass in juvenile SIV-infected rhesus macaques.

A potential mechanism by which torque output is preserved in cerebral palsy during fatiguing contractions of the knee extensors.

INTRODUCTION: The purpose of this study was to compare agonist and antagonist electromyography (EMG) during an isokinetic fatigue protocol in subjects with cerebral palsy (CP) and typical development (TD). METHODS: Nine individuals with CP and 11 with TD completed 50 repetitions of maximum concentric knee extensions (KE) and flexions (KF) at 60°/second. RESULTS: Rate of decline in peak torque for KE was significantly less in CP compared with TD. Rate of decline in agonist EMG was not significantly different between groups, but the rate of decline in antagonist EMG was significantly greater in CP. There were no differences between groups for KF. CONCLUSIONS: Declining agonist EMG occurred in parallel with declining antagonist hamstring activity in CP, decreasing the relative opposing force and resulting in a lesser decline in net torque. This finding illustrates a potential mechanism by which net torque is preserved in those with CP who are inherently weaker.

Conservative versus operative management in stable patients with penetrating abdominal trauma: the experience of a Canadian level 1 trauma centre.

BACKGROUND: The goal of conservative management (CM) of penetrating abdominal trauma is to avoid nontherapeutic laparotomies while identifying injuries early. Factors that may predict CM failure are not well established, and the experience of CM has not been well described in the Canadian context. METHODS: We searched a Canadian level 1 trauma centre database for all penetrating abdominal traumas treated between 2004 and 2014. Hemodynamically stable patients without peritonitis and without clear indications for immediate surgery were considered potential candidates for CM, and were included in the study. We compared those who were managed with CM with those who underwent immediate operative management (OM). Outcomes included mortality and length of stay (LOS). Further analysis was performed to identify predictors of CM failure. RESULTS: A total of 72 patients with penetrating abdominal trauma were classified as potential candidates for CM. Ten patients were managed with OM, and 62 with CM, with 9 (14.5%) ultimately failing CM and requiring laparotomy. The OM and CM groups were similar in terms of age, sex, injury severity, mechanism and number of injuries. There were no deaths in either group. The LOS in the intensive care (ICU)/trauma unit was 4.8 ± 3.2 days in the OM group and 2.9 ± 2.6 days in the CM group (p = 0.039). The only predictor for CM failure was intra-abdominal fluid on computed tomography (CT) scan (odds ratio 5.3, 95% confidence interval 1.01-28.19). CONCLUSION: In select patients with penetrating abdominal trauma, CM is safe and results in a reduced LOS in the ICU/trauma unit of 1.9 days. Fluid on CT scan is a predictor for failure.

CONTEXTE: L'objectif du traitement conservateur des traumatismes abdominaux pénétrants est d'éviter les laparotomies non thérapeutiques tout en ciblant rapidement les blessures. On n'a pas réussi à établir clairement des facteurs permettant de prédire la probabilité d'échec de ce type de traitement, ni bien décrit les paramètres d'utilisation de ce dernier dans le contexte canadien. MÉTHODES: Nous avons recensé dans la base de données d'un centre de traumatologie canadien de niveau 1 tous les cas de traumatismes abdominaux pénétrants traités entre 2004 et 2014. Les patients dont l'état hémodynamique était stable, qui ne souffraient pas de péritonite et qui ne nécessitaient pas manifestement une chirurgie immédiate ont été inclus dans l'étude en tant que candidats potentiels pour le traitement conservateur. Nous avons comparé les patients ayant reçu le traitement conservateur avec ceux ayant tout de suite été opérés. Nous avons entre autres évalué la mortalité et la durée de séjour. D'autres analyses ont été effectuées pour mettre en évidence des indicateurs de l'échec du traitement conservateur. RÉSULTATS: Au total, 72 patients affichant des traumatismes abdominaux pénétrants ont été classés comme des candidats potentiels pour le traitement conservateur. De ce nombre, 10 ont été opérés, et 62 ont reçu le traitement conservateur. Ce dernier a échoué chez 9 patients (14,5 %), qui ont dû subir une laparotomie. Les 2 groupes étaient semblables sur le plan de l'âge, du sexe, de la gravité des blessures et du mécanisme et du nombre de blessures. Aucun décès n'a été observé parmi les 2 groupes. La durée du séjour à l'unité de soins intensifs ou de traumatologie était de 4,8 ± 3,2 jours pour les patients ayant été opérés et de 2,9 ± 2,6 jours pour les patients ayant reçu le traitement conservateur (p = 0,039). Un seul indicateur de l'échec du traitement conservateur a été analysé, soit la présence de fluide intra-abdominal sur le tomodensitogramme (rapport de cotes 5,3; intervalle de confiance à 95 % 1,01-28,19). CONCLUSION: Chez un sous-groupe de patients souffrant de traumatismes abdominaux pénétrants, le traitement conservateur est sécuritaire et se traduit par une durée de séjour inférieure de 1,9 jour. La présence de fluide détectée par tomodensitographie est un indicateur de l'échec du traitement.

Emergence of CD4 independence envelopes and astrocyte infection in R5 simian-human immunodeficiency virus model of encephalitis.

UNLABELLED: Human immunodeficiency virus type 1 (HIV-1) infection in the central nervous system (CNS) is characterized by replication in macrophages or brain microglia that express low levels of the CD4 receptor and is the cause of HIV-associated dementia and related cognitive and motor disorders that affect 20 to 30% of treatment-naive patients with AIDS. Independent viral envelope evolution in the brain has been reported, with the need for robust replication in resident CD4(low) cells, as well as CD4-negative cells, such as astrocytes, proposed as a major selective pressure. We previously reported giant-cell encephalitis in subtype B and C R5 simian-human immunodeficiency virus (SHIV)-infected macaques (SHIV-induced encephalitis [SHIVE]) that experienced very high chronic viral loads and progressed rapidly to AIDS, with varying degrees of macrophage or microglia infection and activation of these immune cells, as well as astrocytes, in the CNS. In this study, we characterized envelopes (Env) amplified from the brains of subtype B and C R5 SHIVE macaques. We obtained data in support of an association between severe neuropathological changes, robust macrophage and microglia infection, and evolution to CD4 independence. Moreover, the degree of Env CD4 independence appeared to correlate with the extent of astrocyte infection in vivo. These findings further our knowledge of the CNS viral population phenotypes that are associated with the severity of HIV/SHIV-induced neurological injury and improve our understanding of the mechanism of HIV-1 cellular tropism and persistence in the brain. IMPORTANCE: Human immunodeficiency virus type 1 (HIV-1) infection of astrocytes in the brain has been suggested to be important in HIV persistence and neuropathogenesis but has not been definitively demonstrated in an animal model of HIV-induced encephalitis (HIVE). Here, we describe a new nonhuman primate (NHP) model of R5 simian-human immunodeficiency virus (SHIV)-induced encephalitis (SHIVE) with several classical HIVE features that include astrocyte infection. We further show an association between severe neuropathological changes, robust resident microglia infection, and evolution to CD4 independence of viruses in the central nervous system (CNS), with expansion to infection of truly CD4-negative cells in vivo. These findings support the use of the R5 SHIVE models to study the contribution of the HIV envelope and viral clades to neurovirulence and residual virus replication in the CNS, providing information that should guide efforts to eradicate HIV from the body.

The formation of inflammatory demyelinated lesions in cerebral white matter.

OBJECTIVE: Vascular permeability and inflammatory demyelination are intimately linked in the brain, but what is their temporal relationship? We aimed to determine the radiological correlates of the earliest tissue changes accompanying demyelination in a primate model of multiple sclerosis (MS), experimental autoimmune encephalomyelitis (EAE) in the common marmoset. METHODS: By 7T magnetic resonance imaging (MRI), T1 maps, proton density, and T2-weighted images were acquired before and after EAE induction in 5 marmosets (every other week before lesions appeared, weekly thereafter). From scans before and after intravenous injection of contrast material, we measured the evolution of lesional blood-brain barrier (BBB) permeability, comparing in vivo MRI to postmortem tissue examination. RESULTS: On average, BBB permeability increased 3.5-fold (p < 0.0001) over the 4 weeks prior to lesion appearance. Permeability gradually decreased after lesion appearance, with attendant changes in the distribution of inflammatory cells (predominantly macrophages and microglia) and demyelination. On tissue analysis, we also identified small perivascular foci of microglia and T cells without blood-derived macrophages or demyelination. These foci had no visible MRI correlates, although permeability within the foci, but not outside, increased in the weeks before the animals died (p < 0.0001). INTERPRETATION: This study provides compelling evidence that in marmoset EAE, which forms lesions strongly resembling those of MS, early changes in vascular permeability are associated with perivascular inflammatory cuffing and parenchymal microglial activation but precede the arrival of blood-derived monocytes that accompany demyelination. Prospective detection of transient permeability changes could afford an opportunity for early intervention to forestall tissue damage in newly forming lesions.

Frequent infection of neurons by SV40 virus in SIV-infected macaque monkeys with progressive multifocal leukoencephalopathy and meningoencephalitis.

Simian virus 40 (SV40), family Polyomaviridae, in immunocompromised macaques can cause fatal demyelinating central nervous system disease analogous to progressive multifocal leukoencephalopathy caused by John Cunningham (JC) virus in immunocompromised humans. Recently, we have demonstrated that JC virus can infect cerebellar granule cell neurons and cortical pyramidal neurons in immunosuppressed people. To examine whether SV40 neuronal infection occurs spontaneously in immunosuppressed macaques, we analyzed archival brain specimens from 20 simian immunodeficiency virus-infected rhesus with AIDS and 1 cynomolgus post-transplant selected with SV40 brain infection from archival records from 1991 to 2012. In addition to white matter SV40 distribution in classic demyelinating progressive multifocal leukoencephalopathy, some of the 21 monkeys exhibited meningeal, subpial neocortical, and periventricular virus. This distribution pattern corresponded to broader viral tropism with neuronal infection in 14 (66.7%) of 21 cases. In all 14 cases, identified neurons were positive for early SV40 transcript large T antigen, but only 4 of the 14 cases exhibited late viral transcript viral protein 1-positive neurons. SV40-infected neurons were detected in frontal, parietal, occipital, and temporal cortices, hippocampus, thalamus, and brain stem. These observations confirm that spontaneous SV40 neuronal infection occurs in immunosuppressed macaques, which parallels JC virus-neuronal infection in immunosuppressed patients. Neuronal infection may be an important aspect of both SV40 and JC virus neuropathogenesis in their respective hosts.

Giant cell encephalitis and microglial infection with mucosally transmitted simian-human immunodeficiency virus SHIVSF162P3N in rhesus macaques.

Neurocognitive disorders such as dementia and cognitive/motor impairments are among the most significant complications associated with human immunodeficiency virus (HIV) infection, especially in aging populations, yet the pathogenesis remains poorly understood. Activated macrophages and microglia in white matter along with the hallmark multinucleated giant cells are prominent features of HIV encephalitis (HIVE) and of several simian immunodeficiency virus (SIV) models. While infected microglia have been demonstrated in HIVE, this feature is not routinely seen in experimental infections in rhesus macaques using SIV or chimeric simian/HIV (SHIV) strains, limiting utility in HIV-1 pathogenesis and treatment studies. Here, 50 rhesus macaques were inoculated with the CCR5 (R5)-tropic SHIVSF162P3N virus by one of three routes: intravenously (n = 9), intrarectally (n = 17), or intravaginally (n = 24). Forty-three monkeys became viremic, 26 developed AIDS, and 7 (7/26, 27 %) developed giant cell SIV encephalitis (SIVE). Rapid progressor phenotype was evident in five of seven (71 %) macaques with SIVE, and expansion to utilize the CXCR4 coreceptor (X4 coreceptor switch) was observed in four out of seven (57 %). SIVE lesions were present in gray and white matter in the cerebrum, cerebellum, thalamus, and brain stem of affected animals. Lesions were composed of virally infected CD68(+), CD163(+), and HLA-DR(+) macrophages accompanied by white matter damage, necrosis, and astroglial and microglial activation. Importantly, microglial infection was observed, which makes R5 SHIVSF162P3N infection of macaques an attractive animal model not only to study transmission and HIVE pathogenesis but also to conduct preclinical evaluation of therapeutic interventions aimed at eradicating HIV-1 from the central nervous system (CNS).

Transcriptomic analysis reveals calcium regulation of specific promoter motifs in Arabidopsis.

Increases in intracellular calcium concentration ([Ca(2+)](c)) mediate plant responses to stress by regulating the expression of genes encoding proteins that confer tolerance. Several plant stress genes have previously been shown to be calcium-regulated, and in one case, a specific promoter motif Abscisic Acid Responsive-Element (ABRE) has been found to be regulated by calcium. A comprehensive survey of the Arabidopsis thaliana transcriptome for calcium-regulated promoter motifs was performed by measuring the expression of genes in Arabidopsis seedlings responding to three calcium elevations of different characteristics, using full genome microarray analysis. This work revealed a total of 269 genes upregulated by [Ca(2+)](c) in Arabidopsis. Bioinformatic analysis strongly indicated that at least four promoter motifs were [Ca(2+)](c)-regulated in planta. We confirmed this finding by expressing in plants chimeric gene constructs controlled exclusively by these cis-elements and by testing the necessity and sufficiency of calcium for their expression. Our data reveal that the C-Repeat/Drought-Responsive Element, Site II, and CAM box (along with the previously identified ABRE) promoter motifs are calcium-regulated. The identification of these promoter elements targeted by the second messenger intracellular calcium has implications for plant signaling in response to a variety of stimuli, including cold, drought, and biotic stress.

Atypical nodular astrocytosis in simian immunodeficiency virus-infected rhesus macaques (Macaca mulatta).

BACKGROUND: Simian immunodeficiency virus (SIV), a model for HIV pathogenesis, is associated with neuropathology. METHODS: Five SIV-infected animals were selected following a database search of 1206 SIV-infected animals for nodular or astrocytic lesions. Two of five had neurologic dysfunction, and 3 of 5 were incidental findings. RESULTS: Histologic examination revealed multifocal nodular foci in the gray and white matter formed by interlacing astrocytes with abundant cytoplasm and large, reactive nuclei. Nodules were often enmeshed with small capillaries. Immunohistochemistry revealed variable immunoreactivity for a panel of markers: GFAP (4/5), vimentin (5/5), Glut-1 (1/5), CNPase (0/5), S100 (5/5), Iba1 (0/5), Ki67 (0/5), and p53 (4/4). In situ hybridization failed to detect any SIV RNA (0/5). Immunohistochemistry for simian virus 40, rhesus cytomegalovirus, and rhesus lymphocryptovirus failed to detect any antigen within the lesions. CONCLUSION: The immunoreactivity of p53 in the lesions compared with adjacent tissue suggests a local derangement in astrocyte proliferation and function.

Music, occupational, physical, and speech therapy interventions for patients in disorders of consciousness: An umbrella review.

BACKGROUND: Current clinical guidelines recommend that a multidisciplinary team inclusive of allied healthcare practitioners deliver assessment and intervention for disorders of consciousness. Allied health professionals include music, occupational, physical, and speech therapists. These allied health clinicians are challenged to select interventions due to a lack of evidence-based recommendations regarding rehabilitation interventions that support recovery of consciousness. This umbrella review synthesizes available systematic reviews (SRs) that describe occupational, speech and language, physical and/or musical therapeutic interventions for people with disorders of consciousness. OBJECTIVES: Identify and summarize evidence from systematic reviews (SRs) that examine allied healthcare interventions for patients with disorders of consciousness. Additionally, this umbrella review aims to evaluate the impact of allied health interventions on recovery of consciousness, methodological quality and risk of bias for the included systematic reviews. METHODS: An umbrella review was completed. The review was reported according to the Preferred Reporting Items for Overview of Reviews (PRIOR) guidance. Five academic databases (PubMed, CINAHL, PsycInfo, Web of Science, and the Cochrane Library) were searched for SRs and/or meta-analyses of allied health (i.e., music, occupational, physical, and speech therapy) interventions for disorders of consciousness. For included studies, data were extracted and quality of the SRs appraised using the A Measurement Tool to Assess Systematic Reviews (AMSTAR) 2 checklist. Data extracted from each SR identified the authors and years of primary studies, interventions, comparators, and outcomes related to recovery of consciousness (i.e., neurobehavioral/cognitive), functional status, physiological response pain, and adverse events. Rehabilitation interventions were categorized and described. RESULTS: Fifteen SRs were included and three of these reviews conducted meta-analyses. Identified rehabilitation interventions included: 1) sensory stimulation, 2) median nerve stimulation, 3) communication/environmental control through assistive technology, 4) mobilization, and 5) music-based therapy. SRs were published between 2002 and 2022 and included 2286 participants. Using the AMSTAR 2, the quality of reviews was critically low (k = 6), low (k = 3), moderate (k = 4), and high (k = 2). SRs within this umbrella review demonstrated significant heterogeneity in research methods and use of outcome measures to evaluate the recovery of consciousness within the primary studies. These factors influenced the ability to conduct meta-analyses. CONCLUSIONS: Sensory stimulation, median nerve stimulation, music therapy and mobilization are all interventions that demonstrate some level of benefit, but current SRs fail to prove benefit through high-level quality evidence. There is an indisputable need for continued rehabilitation research to expand options for treatment modalities and to ensure that the interventions being applied to DoC rehabilitation are evidence-based to improve consciousness and recovery.

Effect of mediolateral leg perturbations on walking balance in people with chronic stroke: A randomized controlled trial.

Many people with chronic stroke (PwCS) exhibit deficits in step width modulation, an important strategy for walking balance. A single exposure to swing leg perturbations can temporarily strengthen this modulation. The objective of this parallel, double-blinded, randomized controlled trial was to investigate whether repeated perturbations cause sustained increases in step modulation (NCT02964039; funded by the VA). 54 PwCS at the Medical University of South Carolina were randomly assigned to one of three intervention groups: Control (n = 18), with minimal forces; Assistive (n = 18), pushing the swing leg toward a mechanically appropriate location; Perturbing (n = 18), pushing the swing leg away from a mechanically appropriate location. All intervention groups included 24 training sessions over 12-weeks with up to 30-minutes of treadmill walking while interfaced with a novel force-field and a 12-week follow-up period, with five interspersed assessment sessions. Our primary outcome measure was paretic step width modulation, the partial correlation between step width and pelvis displacement (ρSW). Secondarily, we quantified swing and stance leg contributions to step modulation, clinical assessments of walking balance and confidence, and real-world falls. Outcomes were analyzed for participants who completed all assessment sessions (n = 44). Only the Perturbing group exhibited significant increases in paretic ρSW, which were present after 4-weeks of training and sustained through follow-up (t = 2.42-3.17). These changes were due to improved control of paretic swing leg positioning. However, perturbation-induced changes in step modulation were not always significantly greater than those in the Control group, and clinical assessments were similar across intervention groups. Participants in the Perturbing group experienced a lower fall rate than those in the Control group (incidence rate ratio = 0.53), although our small sample size warrants caution. The present results indicate that perturbations can cause sustained modifications of targeted biomechanical characteristics of post-stroke gait, although such changes alone may be insufficient to change more complex clinical assessments.