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Reconsolidation may be a viable therapeutic target to inhibit pathological fear memories. In the clinic, incidental or imaginal reminders are used for safe retrieval of traumatic memories of experiences that occurred elsewhere. However, it is unknown whether indirectly retrieved traumatic memories are sensitive to disruption. Here we used a backward (BW) conditioning procedure to indirectly retrieve and manipulate a hippocampus (HPC)-dependent contextual fear engram in male rats. We show that conditioned freezing to a BW conditioned stimulus (CS) is mediated by fear to the conditioning context, activates HPC ensembles that can be covertly captured and chemogenetically activated to drive fear, and is impaired by post-retrieval protein synthesis inhibition. These results reveal that indirectly retrieved contextual fear memories reactivate HPC ensembles and undergo protein synthesis-dependent reconsolidation. Clinical interventions that rely on indirect retrieval of traumatic memories, such as imaginal exposure, may open a window for editing or erasure of neural representations that drive pathological fear.

Introduction Chronic rhinosinusitis (CRS) and functional nasal airway obstruction are common but distinct medical problems which affect quality of life. In certain instances, patients often benefit from concomitant functional septorhinoplasty, or elect for cosmetic rhinoplasty, in addition to functional endoscopic sinus surgery (FESS) and prefer combining procedures. Determining outcomes of combined surgery is important when discussing risks and benefits with patients. Methods A thorough literature search of articles published in PubMed, Ovid MEDLINE, and Cochrane databases. Patients were categorized as either having FESS or rhinoplasty alone or combined. Binary random-effects models were applied to calculate odds ratios (ORs) for outcomes including complications, recurrence, and satisfaction. Results Of the 55 screened articles, 6 were included in the analysis, and of these, 6 (405 patients), 2 (90 patients), 4 (290 patients), and 3 (190 patients) provided data for postoperative complications, recurrence of CRS symptoms, revision rates, and patient satisfaction, respectively. Major complications were observed in 11 (5.8%) total combined cases, 0 (0%) FESS cases, and 6 (3.5%) rhinoplasty cases with no statistical difference between combined cases and rhinoplasties (OR 1.37, 95% CI 0.45–4.16, p = 0.58). Recurrence of CRS symptoms was noted in 35.6% combined cases and 28.9% FESS cases (OR 1.42, 95% CI 0.55–3.64, p = 0.47). There was no observed difference in revision rates between combined and isolated rhinoplasties (OR 1.00, 95% CI 0.43–2.32, p = 1). Lastly, 91.6% of patients were satisfied with results of combined cases compared to 87.4% of patients in standalone cases (OR 1.57, 95% CI 0.61–4.03, p = 0.35). Conclusion Aggregate evidence demonstrates similar risk in complication rates in combined surgical cases compared to stand-alone rhinoplasty. There appears to be no significant difference in recurrence of symptoms, revision rates or patient satisfaction.

Purpose To develop and externally validate a multivariate prediction model for the prediction of acute kidney injury (AKI) in COVID-19, based on baseline renal perfusion from contrast-enhanced CT together with clinical and laboratory parameters. Methods In this retrospective IRB-approved study, we identified COVID-19 patients who had a standard-of-care contrast-enhanced abdominal CT scan within 5 days of their COVID-19 diagnosis at our institution (training set; n = 45, mean age 65 years, M/F 23/22) and at a second institution (validation set; n = 41, mean age 61 years, M/F 22/19). The CT renal perfusion parameter, cortex-to-aorta enhancement index (CAEI), was measured in both sets. A multivariate logistic regression model for predicting AKI was constructed from the training set with stepwise feature selection with CAEI together with demographical and baseline laboratory/clinical data used as input variables. Model performance in the training and validation set was evaluated with ROC analysis. Results AKI developed in 16 patients (35.6%) of the training set and in 6 patients (14.6%) of the validation set. Baseline CAEI was significantly lower in the patients that ultimately developed AKI (P = 0.003). Logistic regression identified a model combining baseline CAEI, blood urea nitrogen, and gender as most significant predictor of AKI. This model showed excellent diagnostic performance for prediction of AKI in the training set (AUC = 0.89, P

Cells sense the extracellular environment and mechanical stimuli and translate these signals into intracellular responses through mechanotransduction, which alters cell maintenance, proliferation, and differentiation. Here we use a mouse model of trauma-induced heterotopic ossification (HO) to examine how cell-extrinsic forces impact mesenchymal progenitor cell (MPC) fate. After injury, single-cell (sc) RNA sequencing of the injury site reveals an early increase in MPC genes associated with pathways of cell adhesion and ECM-receptor interactions, and MPC trajectories to cartilage and bone. Immunostaining uncovers active mechanotransduction after injury with increased focal adhesion kinase signaling and nuclear translocation of transcriptional coactivator TAZ, inhibition of which mitigates HO. Similarly, joint immobilization decreases mechanotransductive signaling, and completely inhibits HO. Joint immobilization decreases collagen alignment and increases adipogenesis. Further, scRNA sequencing of the HO site after injury with or without immobilization identifies gene signatures in mobile MPCs correlating with osteogenesis, and signatures from immobile MPCs with adipogenesis. scATAC-seq in these same MPCs confirm that in mobile MPCs, chromatin regions around osteogenic genes are open, whereas in immobile MPCs, regions around adipogenic genes are open. Together these data suggest that joint immobilization after injury results in decreased ECM alignment, altered MPC mechanotransduction, and changes in genomic architecture favoring adipogenesis over osteogenesis, resulting in decreased formation of HO.

Purpose The study investigators hypothesized that Point of Care Ultrasound (POCUS) training through bolus didactic and workshop experiences may be sufficient for trainees to learn the cognitive aspects, while an extended period of exposure with formative feedback is responsible for developing the psychomotor skills critical for POCUS. Methods The investigators studied trainees over the course of an academic year. They compared trainees' performance on written (cognitive) and observed image acquisition (psychomotor) exams at baseline and at each subsequent quarter, using a stepped-wedge design. They performed linear regression analysis to determine which variables contributed to knowledge and psychomotor skill development. Results Twenty-six trainees met the study requirements and participated in the POCUS curriculum. Participating in a POCUS rotation was consistently associated with an increase in psychomotor scores. There was no consistent variable to predict an increase in trainee's score on written knowledge assessments. Conclusions Extended exposure to POCUS over a 4-week rotation with direct and indirect formative feedback can explain difference in scores on psychomotor skills assessments. Trainees scored similarly on the written assessment with or without a POCUS rotation. Training through didactic and workshop experiences may be sufficient to learn the cognitive aspects, but not psychomotor skills required for POCUS.

Overexpression of centromeric proteins has been identified in a number of human malignancies, but the functional and mechanistic contributions of these proteins to disease progression have not been characterized. The centromeric histone H3 variant centromere protein A (CENPA) is an epigenetic mark that determines centromere identity. Here, using an array of approaches, including RNA-sequencing and ChIP-sequencing analyses, immunohistochemistry-based tissue microarrays, and various cell biology assays, we demonstrate that CENPA is highly overexpressed in prostate cancer in both tissue and cell lines and that the level of CENPA expression correlates with the disease stage in a large cohort of patients. Gain-of-function and loss-of-function experiments confirmed that CENPA promotes prostate cancer cell line growth. The results from the integrated sequencing experiments suggested a previously unidentified function of CENPA as a transcriptional regulator that modulates expression of critical proliferation, cell-cycle, and centromere/kinetochore genes. Taken together, our findings show that CENPA overexpression is crucial to prostate cancer growth.

Studies in rodents and captive primates suggest that the early-life social environment affects future phenotype, potentially through alterations to DNA methylation. Little is known of these associations in wild animals. In a wild population of spotted hyenas, we test the hypothesis that maternal care during the first year of life and social connectedness during two periods of early development leads to differences in DNA methylation and fecal glucocorticoid metabolites (fGCMs) later in life. Here we report that although maternal care and social connectedness during the den-dependent life stage are not associated with fGCMs, greater social connectedness during the subadult den-independent life stage is associated with lower adult fGCMs. Additionally, more maternal care and social connectedness after den independence correspond with higher global (%CCGG) DNA methylation. We also note differential DNA methylation near 5 genes involved in inflammation, immune response, and aging that may link maternal care with stress phenotype., Early social experience can alter epigenetic patterns and stress responses later in life. A study on wild spotted hyenas finds that maternal care and social connections after leaving the den influence DNA methylation and contribute to a developmentally plastic stress response.

Heterotopic ossification (HO) is a devastating condition in which ectopic bone forms inappropriately in soft tissues following traumatic injuries and orthopedic surgeries as a result of aberrant mesenchymal progenitor cell (MPC) differentiation. HO leads to chronic pain, decreased range of motion, and an overall decrease in quality of life. While several treatments have shown promise in animal models, all must be given during early stages of formation. Methods for early determination of whether and where endochondral ossification/soft tissue mineralization (HO anlagen) develop are lacking. At-risk patients are not identified sufficiently early in the process of MPC differentiation and soft tissue endochondral ossification for potential treatments to be effective. Hence, a critical need exists to develop technologies capable of detecting HO anlagen soon after trauma, when treatments are most effective. In this study, we investigate high frequency spectral ultrasound imaging (SUSI) as a noninvasive strategy to identify HO anlagen at early time points after injury. We show that by determining quantitative parameters based on tissue organization and structure, SUSI identifies HO anlagen as early as 1-week postinjury in a mouse model of burn/tenotomy and 3 days postinjury in a rat model of blast/amputation. We analyze single cell RNA sequencing profiles of the MPCs responsible for HO formation and show that the early tissue changes detected by SUSI match chondrogenic and osteogenic gene expression in this population. SUSI identifies sites of soft tissue endochondral ossification at early stages of HO formation so that effective intervention can be targeted when and where it is needed following trauma-induced injury. Furthermore, we characterize the chondrogenic to osteogenic transition that occurs in the MPCs during HO formation and correlate gene expression to SUSI detection of the HO anlagen.

Considerable work indicates that instrumental responding is context-dependent, but the neural mechanisms underlying this phenomenon are poorly understood. Given the important role for the hippocampal formation in contextual processing, we hypothesized that reversible inactivation of the hippocampus would impair the context-dependence of active avoidance. To test this hypothesis, we used a two-way signaled active avoidance (SAA) task that requires rats to shuttle across a divided chamber during a tone CS in order to avoid a footshock US. After training, avoidance responding was assessed in an extinction test in both the training context and a novel context in a counterbalanced order. Rats performed significantly more avoidance responses in the training context than in the novel context, demonstrating the context-dependence of shuttle avoidance behavior. To examine the role of the hippocampus in the context-dependence of SAA, we reversibly inactivated either the dorsal (DH) or ventral hippocampus (VH) prior to testing. Inactivation of the VH eliminated the context-dependence of SAA and elevated avoidance responding in the novel context to levels similar to that expressed in the training context. In contrast, DH inactivation had no effect on avoidance in either context, and neither manipulation affected freezing behavior. Therefore, the integrity of the VH, but not DH, is required for the expression context-dependence of avoidance behavior.

Polybrominated diphenyl ethers (PBDEs) are brominated flame retardant chemicals and environmental contaminants with endocrine-disrupting properties that are associated with diabetes and metabolic syndrome in humans. However, their diabetogenic actions are not completely characterized or understood. In this study, we investigated the effects of DE-71, a commercial penta-mixture of PBDEs, on glucose regulatory parameters in a perinatal exposure model using female C57Bl/6 mice. Results fromin vivoglucose and insulin tolerance tests andex vivoanalyses showed that DE-71 produced fasting hyperglycemia, glucose intolerance, reduced sensitivity and delayed glucose clearance after insulin challenge, and exaggerated hepatic endocannabinoid tone in F1 offspring exposed to 0.1 mg/kg DE-71 relative to control. DE-71 effects on F0 dams were more limited indicating that indirect exposure to developing offspring is more detrimental. Otherex vivoglycemic correlates occur more generally in exposed F0 and F1, i.e., reduced plasma insulin and altered glucoregulatory endocrines, exaggerated sympathoadrenal activity, decreased thermogenic brown adipose tissue mass and reduced hepatic glutamate dehydrogenase enzymatic activity. Hepatic PBDE congener analysis indicated maternal transfer of BDE-28 and −153 to F1 at a collective level of 200 ng/g lipid, in range with maximum values detected in serum of human females. Given the persistent diabetogenic phenotype, especially pronounced in female offspring after developmental exposure to environmentally relevant levels of DE-71, additional animal studies should be conducted that further characterize PBDE-induced diabetic pathophysiology and identify critical developmental time windows of susceptibility. Longitudinal human studies should also be conducted to determine the risk of long-lasting metabolic consequences after maternal transfer of PBDEs during early-life development.

Anterior interosseous nerve syndrome (AINS) represents a form of neuralgic amyotrophy (Parsonage-Turner syndrome). AINS does not originate from external compression of the AIN in the forearm. Fascicular constrictions (FCs) of the median nerve are identified within the anterior interosseous fascicular group at or above the medial epicondyle. Spontaneous recovery is not ensured, leaving up to 30% of patients with permanent weakness or palsy. Fascicular microneurolysis of the median nerve, performed at or above the elbow, is a treatment option for patients who do not recover spontaneously.

Leviviruses are bacteriophages with small single-stranded RNA genomes consisting of 3-4 genes, one of which (sgl) encodes a protein that induces the host to undergo autolysis and liberate progeny virions. Recent meta-transcriptomic studies have uncovered thousands of leviviral genomes, but most of these lack an annotated sgl, mainly due to the small size, lack of sequence similarity, and embedded nature of these genes. Here, we identify sgl genes in 244 leviviral genomes and functionally characterize them in Escherichia coli. We show that leviviruses readily evolve sgl genes and sometimes have more than one per genome. Moreover, these genes share little to no similarity with each other or to previously known sgl genes, thus representing a rich source for potential protein antibiotics., Leviviruses are phages with ssRNA genomes that encode a protein (Sgl) that induces host autolysis by interfering with bacterial cell wall synthesis. Identification of sgl genes is complicated by their small size and lack of sequence similarity. Here, Chamakura et al. use bioinformatic and experimental approaches to identify sgl genes in 244 leviviral genomes.

Summary Heterotopic ossification (HO) is a form of pathological cell-fate change of mesenchymal stem/precursor cells (MSCs) that occurs following traumatic injury, limiting range of motion in extremities and causing pain. MSCs have been shown to differentiate to form bone; however, their lineage and aberrant processes after trauma are not well understood. Utilizing a well-established mouse HO model and inducible lineage-tracing mouse (Hoxa11-CreERT2;ROSA26-LSL-TdTomato), we found that Hoxa11-lineage cells represent HO progenitors specifically in the zeugopod. Bioinformatic single-cell transcriptomic and epigenomic analyses showed Hoxa11-lineage cells are regionally restricted mesenchymal cells that, after injury, gain the potential to undergo differentiation toward chondrocytes, osteoblasts, and adipocytes. This study identifies Hoxa11-lineage cells as zeugopod-specific ectopic bone progenitors and elucidates the fate specification and multipotency that mesenchymal cells acquire after injury. Furthermore, this highlights homeobox patterning genes as useful tools to trace region-specific progenitors and enable location-specific gene deletion., Graphical Abstract, Highlights • Lineage tracing, single-cell RNA-seq and single cell ATAC enable cell specific analysis of in vivo cell fate • Hoxa11 lineage marks distinct mesenchymal precursors in the zeugopod • Hoxa11 lineage mesenchymal precursors undergo an aberrant cell fate change towards ectopic bone and cartilage, Here, Pagani et al. use the Hoxa11 patterning gene, expressed exclusively in the limb zeugopod, to demonstrate by bioinformatic single cell transcriptomic, epigenomic analyses, and ex vivo confocal microscopy that extra-skeletal cells originating from Hoxa11 lineage cells are a population of mesenchymal cells with the ability to undergo aberrant differentiation towards chondrocytes, osteoblasts or adipocytes after injury

The small lytic phages (Microviridae and Leviviridae), effect bacterial lysis with the product of a single gene. The three well-studied single-gene lysis (Sgl) proteins (E of φX174, A2 of Qβ, and LysM of phage M) lack direct muralytic activity, and have been shown to function as 'protein antibiotics' by acting as noncompetitive inhibitors of conserved peptidoglycan (PG) biosynthesis enzymes, MurA, MraY, and MurJ respectively. The fourth, protein L of MS2, does not inhibit PG biosynthesis but instead is hypothesized to trigger host autolytic response through an unknown mechanism. Recent advances in meta-omics approaches have led to an explosion in the available genomes of small lytic phages. Of the thousands of new genomes, only one annotated Sgl shared some sequence similarity with a known Sgl (L of MS2), highlighting the diversity in Sgls. The newly available genomic space serves as an untapped resource for discovering novel Sgls.

BACKGROUND: Injuries to the hand and wrist constitute up to 25% of all athletic injuries, yet not much information is available on the effects of such injuries on the careers of professional athletes. Understanding whether elite athletes can return to sport and at what level has value for athletes, coaches, managers, and others, including athletes at other levels of play. QUESTIONS/PURPOSES: The purpose of this study was to systematically review the literature on injuries of the hand and wrist in professional athletes to determine the prevalence and types of injuries sustained in professional sports, the management and clinical outcomes of such injuries, and the statistics regarding return to play. METHODS: A systematic review was conducted of PubMed/MEDLINE and the Cochrane Central Register of Controlled Trials to identify all studies reporting on hand and wrist injuries in professional athletes that were published between January 1970 and April 2019. Inclusion criteria were injuries of the upper extremity distal to the elbow that occurred in professional athletes during athletic competition, English language, and a study cohort consisting of four or more subjects. Details of injury sustained, sport, treatment, clinical outcome, and return to sport were extracted. RESULTS: We identified 32 nonoverlapping studies involving a total of 4299 hand and wrist injuries. The most common sport studied was baseball (eight studies), followed by football (seven), boxing (six), and basketball (five). Specific injury type was included in 29 of 32 studies and totaled 792 injuries. Metacarpal fractures were the most common injuries (n = 273; 34.5%), followed by thumb collateral ligament injuries (n = 110; 13.9%), phalangeal fractures (n = 87; 11.0%), and scaphoid fractures (n = 56; 7.1%). The overall operative rate was 18.3% (n = 708 of 3867). One-half of the studies reported the return to play (average, 2.8 months; range, 0.5 to 9 months). Seven studies reported sport-specific objective performance measures, with six describing consistent return to preinjury levels of performance among athletes. CONCLUSIONS: Based on the available evidence, a large majority of hand and wrist injuries in professional athletes are treated conservatively. Athletes frequently return to preinjury levels of performance after surgery. Additionally, return to play after a hand injury appears to be faster than that after other bony injuries. Further research is needed into the impact of these injuries on athletic performance, as well as how surgical intervention affects validated patient-reported outcome measures in professional athletes. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s11420-020-09760-w) contains supplementary material, which is available to authorized users.

The thalamic nucleus reuniens (RE) receives dense projections from the medial prefrontal cortex (mPFC), interconnects the mPFC and hippocampus, and may serve a pivotal role in regulating emotional learning and memory. Here we show that the RE and its mPFC afferents are critical for the extinction of Pavlovian fear memories in rats. Pharmacological inactivation of the RE during extinction learning or retrieval increases freezing to an extinguished conditioned stimulus (CS); renewal of fear outside the extinction context was unaffected. Suppression of fear in the extinction context is associated with an increase in c-fos expression and spike firing in RE neurons to the extinguished CS. The role for the RE in suppressing extinguished fear requires the mPFC, insofar as pharmacogenetically silencing mPFC to RE projections impairs the expression of extinction memory. These results reveal that mPFC-RE circuits inhibit the expression of fear, a function that is essential for adaptive emotional regulation., Previous work has shown that the thalamic nucleus reuniens (RE) is involved in memory and emotion. Here the authors report that the RE and its inputs from the medial prefrontal cortex are indispensable for the top-down inhibition of fear memories after extinction.

Purpose The purpose of the study was to evaluate the utility of the levator scapulae motor nerve (LSN) as a donor nerve for brachial plexus nerve transfer. We hypothesized that the LSN could be transferred to the suprascapular nerve (SSN) or long thoracic nerve (LTN) with a reliable tension-free coaptation and appropriate donor-to-recipient axon count ratio. Methods Twelve brachial plexus dissections were performed on 6 adult cadavers, bilaterally. We identified the LSN, spinal accessory nerve (SAN), SSN, and LTN. Each nerve was prepared for transfer and nerve redundancies were calculated. Cross-sections of each nerve were examined histologically, and axons counted. We transferred the LSN to target first the SSN and then the LTN, in a tension-free coaptation. For reference, we transferred the distal SAN to target the SSN and LTN and compared transfer parameters. Results Three cadavers demonstrated 2 LSN branches supplying the levator scapulae. The axon count ratio of donor-to-recipient nerve was 1:4.0 (LSN:SSN) and 1:2.1 (LSN:LTN) for a single LSN branch and 1:3.0 (LSN:SSN) and 1:1.6 (LSN:LTN) when 2 LSN branches were available. Comparatively, the axon count ratio of donor-to-recipient nerve was 1:2.5 and 1:1.3 for the SAN to the SSN and the LTN, respectively. The mean redundancy from the LSN to the SSN and the LTN was 1.7 cm (SD, 3.1 cm) and 2.9 cm (SD, 2.8 cm), and the redundancy from the SAN to the SSN and the LTN was 4.5 (SD, 0.7 cm) and 0.75 cm (SD, 1.0 cm). Conclusions These data support the use of the LSN as a potential donor for direct nerve transfer to the SSN and LTN, given its adequate redundancy and size match. Clinical relevance The LSN should be considered as an alternative nerve donor source for brachial plexus reconstruction, especially in 5-level injuries with scarce donor nerves. If used in lieu of the SAN during primary nerve reconstruction, trapezius tendon transfer for improved external rotation would be enabled.

Learning and remembering the context in which events occur requires interactions between the hippocampus (HPC) and medial prefrontal cortex (mPFC). The nucleus reuniens (RE) is a ventral midline thalamic nucleus that coordinates activity in the mPFC and HPC and is involved in spatial and contextual memory. We recently found that the RE is critical for contextual fear conditioning in rats, a form of learning that involves interactions between the HPC and mPFC. Here we examined whether the RE mediates the extinction of contextual fear. After contextual fear conditioning, rats underwent an extinction procedure in which they were merely exposed to the conditioning context; freezing behavior during the extinction procedure and during a retrieval test 24 h later served as an index of conditioned fear. Muscimol inactivation of the RE prior to extinction impaired the acquisition of both short- and long-term extinction memories. Similarly, inactivation of the RE prior to the extinction retrieval test also impaired the expression of extinction; this effect was not state-dependent. Taken together, these results reveal that the extinction of contextual fear memories requires the RE, which is consistent with a broader role for the RE in forms of learning that require HPC-mPFC interactions.

Stress impairs extinction learning, and these deficits depend, in part, on stress-induced norepinephrine (NE) release in the basolateral amygdala (BLA). For example, systemic or intra-BLA administration of propranolol reduces the immediate extinction deficit (IED), an impairment in extinction learning that occurs when extinction trials are administered soon after fear conditioning. Here, we explored whether locus coeruleus (LC)-NE regulates stress-induced changes in spike firing in the BLA and consequent extinction learning impairments. Rats were implanted with recording arrays in the BLA and, after recovery from surgery, underwent a standard auditory fear conditioning procedure. Fear conditioning produced an immediate and dramatic increase in the spontaneous firing of BLA neurons that persisted (and in some units, increased further) up to an hour after conditioning. This stress-induced increase in BLA firing was prevented by systemic administration of propranolol. Conditioning with a weaker footshock caused smaller increases in BLA firing rate, but this could be augmented by chemogenetic activation of the LC. Conditioned freezing in response to a tone paired with a weak footshock was immune to the IED, but chemogenetic activation of the LC before the weak conditioning protocol increased conditioned freezing behavior and induced an IED; this effect was blocked with intra-BLA infusions of propranolol. These data suggest that stress-induced activation of the LC increases BLA spike firing and causes impairments in extinction learning. Stress-induced increases in BLA activity mediated by LC-NE may be a viable therapeutic target for individuals with stress- and trauma-related disorders.SIGNIFICANCE STATEMENTPatients with post-traumatic stress disorder (PTSD) show heightened amygdala activity; elevated levels of stress hormones, including norepinephrine; and are resistant to the extinction of fear memories. Here, we show that stress increases basolateral amygdala (BLA) spike firing. This could be attenuated by systemic propranolol and mimicked by chemogenetic activation of the locus coeruleus (LC), the source of forebrain norepinephrine (NE). Finally, we show that LC-NE activation is sufficient to produce extinction deficits, and this is blocked by intra-BLA propranolol. Stress-induced increases in BLA activity mediated by LC-NE may be a viable therapeutic target for individuals with PTSD and related disorders.

The nucleus reuniens (RE) is a ventral midline thalamic nucleus that interconnects the medial prefrontal cortex (mPFC) and hippocampus (HPC). Considerable data indicate that HPC-mPFC circuits are involved in contextual and spatial memory; however, it is not clear whether the RE mediates the acquisition or retrieval of these memories. To examine this question, we inactivated the RE with muscimol before either the acquisition or retrieval of Pavlovian fear conditioning in rats; freezing served as the index of fear. We found that RE inactivation before conditioning impaired the acquisition of contextual freezing, whereas inactivation of the RE prior to retrieval testing increased the generalization of freezing to a novel context; inactivation of the RE did not affect either the acquisition or expression of auditory fear conditioning. Interestingly, contextual conditioning impairments were absent when retrieval testing was also conducted after RE inactivation. Contextual memories acquired under RE inactivation were hippocampal-independent, insofar as contextual freezing in rats conditioned under RE inactivation was insensitive to intra-hippocampal infusions of the NMDA receptor antagonist, D,L-amino-5-phosophonovaleric acid (APV). Together, these data reveal that the RE supports hippocampal-dependent encoding of precise contextual memories that allow discrimination of dangerous from safe contexts. When the RE is inactive, however, alternate neural systems acquire an impoverished contextual memory that is only expressed when the RE is offline.SIGNIFICANCE STATEMENTThe midline thalamic nucleus reuniens (RE) coordinates communication between the hippocampus and medial prefrontal cortex, brain areas critical for contextual and spatial memory. Here we show that temporary pharmacological inactivation of RE impairs the acquisition and precision of contextual fear memories after Pavlovian fear conditioning in rats. However, inactivating the RE prior to retrieval testing restored contextual memory in rats conditioned after RE inactivation. Critically, we show that imprecise contextual memories acquired under RE inactivation are learned independently of the hippocampus. These data reveal that the RE is required for hippocampal-dependent encoding of precise contextual memories to support the discrimination of safe and dangerous contexts.

Objective Aging is associated with the development of diseases because of immunosuppression and altered functioning of the neuroendocrine system. The medicinal properties of Morinda citrifolia L. have been widely exploited for the treatment of age-associated diseases. This study aims to investigate the in vitro and in vivo effects of noni (M. citrifolia) fruit juice (NFJ) on neuro-immunomodulation in the lymph node lymphocytes of F344 rats. Methods Lymphocytes isolated from axillary and inguinal lymph nodes of young (3–4 months) and old (18–21 months) rats were treated in vitro with different concentrations (0.0001%, 0.01%, and 1%) of NFJ for a period of 24 h. In the in vivo study, old (16–17 months) male F344 rats were treated with 5 mL/kg body weight of 5%, 10% and 20% of NFJ, twice a day, by oral gavage, and lymph node lymphocytes were isolated after 60 d. Concanavalin A (Con A)-induced lymphocyte proliferation, interleukin-2 (IL-2) and interferon-γ (IFN-γ) production and expression of intracellular markers, such as phospho-extracellular signal-regulated kinase (p-ERK1/2), phospho-cAMP response element-binding protein, phospho-protein kinase B (p-Akt), phospho-tyrosine hydroxylase (p-TH), phospho-nuclear factor of κ light polypeptide gene enhancer in B-cells inhibitor-α (p-IκB-α) and phospho-nuclear factor-κB (p-NF-κB p65 and p50) were examined in the lymphocytes of lymph nodes. Results NFJ increased Con A-induced lymphocyte proliferation, IL-2 and IFN-γ production, and p-ERK1/2 expression both in vitro and in vivo. In in vivo NFJ-treated old rats, lymph node lymphocytes showed increased expression of p-TH and Akt, nitric oxide production and decreased expression of p-NF-κB p65 and p50. Conclusion These results suggest that the immunostimulatory properties of NFJ are facilitated through intracellular signaling pathways involving ERK1/2, Akt and NF-κB.

Small single-stranded nucleic acid phages effect lysis by expressing a single protein, the amurin, lacking muralytic enzymatic activity. Three amurins have been shown to act like ‘protein antibiotics’ by inhibiting cell-wall biosynthesis. However, the L lysis protein of the canonical ssRNA phage MS2, a 75 aa polypeptide, causes lysis by an unknown mechanism without affecting net peptidoglycan synthesis. To identify residues important for lytic function, randomly mutagenized alleles of L were generated, cloned into an inducible plasmid and the transformants were selected on agar containing the inducer. From a total of 396 clones, 67 were unique single base-pair changes that rendered L non-functional, of which 44 were missense mutants and 23 were nonsense mutants. Most of the non-functional missense alleles that accumulated in levels comparable to the wild-type allele are localized in the C-terminal half of L, clustered in and around an LS dipeptide sequence. The LS motif was used to align L genes from ssRNA phages lacking any sequence similarity to MS2 or to each other. This alignment revealed a conserved domain structure, in terms of charge, hydrophobic character and predicted helical content. None of the missense mutants affected membrane-association of L. Several of the L mutations in the central domains were highly conservative and recessive, suggesting a defect in a heterotypic protein–protein interaction, rather than in direct disruption of the bilayer structure, as had been previously proposed for L.

Exposure-based therapies help patients with post-traumatic stress disorder (PTSD) to extinguish conditioned fear of trauma reminders. However, controlled laboratory studies indicate that PTSD patients do not extinguish conditioned fear as well as healthy controls, and exposure therapy has high failure and dropout rates. The present study examined whether vagus nerve stimulation (VNS) augments extinction of conditioned fear and attenuates PTSD-like symptoms in an animal model of PTSD. To model PTSD, rats were subjected to a single prolonged stress (SPS) protocol, which consisted of restraint, forced swim, loss of consciousness, and 1 week of social isolation. Like PTSD patients, rats subjected to SPS show impaired extinction of conditioned fear. The SPS procedure was followed, 1 week later, by auditory fear conditioning (AFC) and extinction. VNS or sham stimulation was administered during half of the extinction days, and was paired with presentations of the conditioned stimulus. One week after completion of extinction training, rats were given a battery of behavioral tests to assess anxiety, arousal and avoidance. Results indicated that rats given SPS 1 week prior to AFC (PTSD model) failed to extinguish the freezing response after eleven consecutive days of extinction. Administration of VNS reversed the extinction impairment and attenuated reinstatement of the conditioned fear response. Delivery of VNS during extinction also eliminated the PTSD-like symptoms, such as anxiety, hyperarousal and social avoidance for more than 1 week after VNS treatment. These results provide evidence that extinction paired with VNS treatment can lead to remission of fear and improvements in PTSD-like symptoms. Taken together, these findings suggest that VNS may be an effective adjunct to exposure therapy for the treatment of PTSD.

The L protein of the single-stranded RNA phage MS2 causes lysis of Escherichia coli without inducing bacteriolytic activity or inhibiting net peptidoglycan (PG) synthesis. To find host genes required for L-mediated lysis, spontaneous Ill ( i nsensitivity to L l ysis) mutants were selected as survivors of L expression and shown to have a missense change of the highly conserved proline (P330Q) in the C-terminal domain of DnaJ. In the dnaJ P330Q mutant host, L-mediated lysis is completely blocked at 30°C without affecting the intracellular levels of L. At higher temperatures (37°C and 42°C), both lysis and L accumulation are delayed. The lysis block at 30°C in the dnaJ P330Q mutant was recessive and could be suppressed by L o vercomes d na J ( L odj ) alleles selected for restoration of lysis. All three L odj alleles lack the highly basic N-terminal half of the lysis protein and cause lysis ∼20 min earlier than full-length L. DnaJ was found to form a complex with full-length L. This complex was abrogated by the P330Q mutation and was absent with the L odj truncations. These results suggest that, in the absence of interaction with DnaJ, the N-terminal domain of L interferes with its ability to bind to its unknown target. The lysis retardation and DnaJ chaperone dependency conferred by the nonessential, highly basic N-terminal domain of L resembles the SlyD chaperone dependency conferred by the highly basic C-terminal domain of the E lysis protein of ϕX174, suggesting a common theme where single-gene lysis can be modulated by host factors influenced by physiological conditions. IMPORTANCE Small single-stranded nucleic acid lytic phages ( Microviridae and Leviviridae ) lyse their host by expressing a single “protein antibiotic.” The protein antibiotics from two out of three prototypic small lytic viruses have been shown to inhibit two different steps in the conserved PG biosynthesis pathway. However, the molecular basis of lysis caused by L, the lysis protein of the third prototypic virus, MS2, is unknown. The significance of our research lies in the identification of DnaJ as a chaperone in the MS2 L lysis pathway and the identification of the minimal lytic domain of MS2 L. Additionally, our research highlights the importance of the highly conserved P330 residue in the C-terminal domain of DnaJ for specific protein interactions.

For bacteriophage infections, the cell walls of bacteria, consisting of a single highly polymeric molecule of peptidoglycan (PG), pose a major problem for the release of progeny virions. Phage lysis proteins that overcome this barrier can point the way to new antibacterial strategies 1 , especially small lytic single-stranded DNA (the microviruses) and RNA phages (the leviviruses) that effect host lysis using a single non-enzymatic protein 2 . Previously, the A2 protein of levivirus Qβ and the E protein of the microvirus ϕX174 were shown to be 'protein antibiotics' that inhibit the MurA and MraY steps of the PG synthesis pathway 2-4 . Here, we investigated the mechanism of action of an unrelated lysis protein, LysM, of the Escherichia coli levivirus M 5 . We show that LysM inhibits the translocation of the final lipid-linked PG precursor called lipid II across the cytoplasmic membrane by interfering with the activity of MurJ. The finding that LysM inhibits a distinct step in the PG synthesis pathway from the A2 and E proteins indicates that small phages, particularly the single-stranded RNA (ssRNA) leviviruses, have a previously unappreciated capacity for evolving novel inhibitors of PG biogenesis despite their limited coding potential.

In this study, bacterial strains were isolated from curd and evaluated its bactericidal potential against two aquatic pathogens Salmonella sp and Vibrio sp isolated from marine fish, Parastromateus niger and squid, Loligo duvauceli. Based on the antimicrobial activity, potential strain was selected and identified as Bacillus sp. Further, bacteriocin was partially purified from the Bacillus sp by ammonium sulphate precipitation and dialysis. The molecular weight of the partially purified bacteriocin was estimated by SDS-PAGE. To understand the biopreservative ability of the purified bacteriocin, tissues of Salmonella and Vibrio-infected fish, Parastromateus niger and Loligo duvauceli were treated with bacteriocin for 30 days at different storage conditions (-4°C and -20°C) and the microbial load was counted at 5, 10, 15, 20, 25 and 30 days. Results showed that bacteriocin significantly reduced the total bacterial count at both storage temperatures in a time dependent manner. This study proved the efficiency of bactericidal and biopreservative activity of bacteriocin isolated from Bacillus subtilis (KY808492).

Angina Bullosa Hemmorhagica is a condition affecting the oral mucous membrane characterised by the presence of oral subepithelial blood filled blisters that ruptures and heals spontaneously by itself without any scarring.

Purpose There are no commercially available devices to measure visual fields in infants. We developed a device, “Pediatric Perimeter,” that quantifies visual field extent (VFE) for infants. We describe the construction, validation, and use of this device. Methods A hemispherical dome with light emitting diodes (LEDs) was constructed. The LEDs were controlled using a computer program to measure reaction time (RT) to gross visual fields (GVF) and the VFE. Participants were tested in supine position in a dark room. Eye or head movement towards the stimuli was monitored with an infrared (IR) camera. Validation was done on 10 adults (mean age: 24.4 ± 5 years) with tunnel vision simulator. Results Perimetry was performed on 19 infants (age: 2.3–12 months), five infants with normal milestones. GVF and VFE were estimated in 17 and 7 infants, respectively. Median RT of infants with developmental delay was 663 ms and 380 ms for healthy infants. Also, 14 children (age: 14 months–6 years) with developmental delay and five patients with cognitive impairment were tested. Conclusion Visual field isopter and RT can be examined with the Pediatric Perimeter device on infants and patients with special needs. Further testing on infants will need to assess the repeatability. A large-scale study will be needed to compare typically developing infants and infants with delayed milestones with this device. Translational Relevance Quantifiable parameters obtained with this device can be used as outcome measures in clinical examination of infants and patients with special needs. This device can be used in pediatric, neurology, and ophthalmology clinics.