Effectiveness and optimization of low-sodium oxybate in participants with narcolepsy switching from a high-sodium oxybate: data from the SEGUE study.

STUDY OBJECTIVES: Low-sodium oxybate (LXB; calcium, magnesium, potassium, and sodium oxybates; Xywav) contains the same active moiety as high-sodium oxybates (sodium oxybate [SXB; Xyrem] and fixed-dose sodium oxybate [Lumryz]), with 92% less sodium, and is approved in the US for treatment of cataplexy or excessive daytime sleepiness in patients 7 years of age and older with narcolepsy, and idiopathic hypersomnia in adults. Patients with narcolepsy have increased cardiovascular risk relative to people without narcolepsy. LXB's lower sodium content is recognized by the US FDA in the narcolepsy population as clinically meaningful in reducing cardiovascular morbidity compared with high-sodium oxybates. The Substitution of Equal Grams of Uninterrupted Xyrem to Xywav (SEGUE) study (NCT04794491) examined the transition experience of patients with narcolepsy switching from SXB to LXB. METHODS: Eligible participants were aged 18 to 80 years with narcolepsy type 1 or 2 on a stable SXB dose/regimen. After 2 weeks, participants transitioned gram-per-gram to LXB for 6 weeks, with opportunity for subsequent titration. Assessments included the Epworth Sleepiness Scale (ESS), Patient Global Impression of Change (PGIc), ease of switching medication scale (EOSMS), and forced preference questionnaire (FPQ). RESULTS: The study enrolled 62 participants at baseline; 60 transitioned to LXB and 54 completed the study. At baseline and end of the LXB intervention/early discontinuation, respectively, mean total doses were 8.0 and 8.0 g/night; mean ESS scores were 9.4 and 8.8. Most participants reported improvement (45%) or no change (48%) in narcolepsy symptoms on the PGIc, reported the transition to LXB was "easy" (easy, extremely easy, not difficult at all; 93%) on the EOSMS, and preferred LXB compared with SXB (79%) on the FPQ, most commonly due to the lower sodium content. CONCLUSIONS: Most participants switched from SXB to LXB with minimal modifications of dose/regimen and reported the transition process was easy. Effectiveness of oxybate treatment was maintained on LXB, and most participants preferred LXB to SXB. No new safety or tolerability issues were identified. CLINICALTRIALREGISTRATION: Registry: ClinicalTrials.gov; Name: An Interventional Safety Switch Study (Segue Study) of XYWAV in Narcolepsy; URL: https://classic.clinicaltrials.gov/ct2/show/NCT04794491; Identifier: NCT04794491.

dTrmt10A impacts Hsp70 chaperone m6A levels and the stress response in the Drosophila brain.

Chronic cellular stress has a profound impact on the brain, leading to degeneration and accelerated aging. Recent work has revealed the vital role of RNA modifications, and the proteins responsible for regulating them, in the stress response. In our study, we defined the role of CG14618/dTrmt10A, the Drosophila counterpart of human TRMT10A a N1-methylguanosine methyltransferase, on m6A regulation and heat stress resilience in the Drosophila brain. By m6A-IP RNA sequencing on Drosophila head tissue, we demonstrated that manipulating dTrmt10A levels indirectly regulates m6A levels on polyA + RNA. dTrmt10A exerted its influence on m6A levels on transcripts enriched for neuronal signaling and heat stress pathways, similar to the m6A methyltransferase Mettl3. Intriguingly, its impact primarily targeted 3' UTR m6A, setting it apart from the majority of Drosophila m6A-modified transcripts which display 5' UTR enrichment. Upregulation of dTrmt10A led to increased resilience to acute heat stress, decreased m6A modification on heat shock chaperones, and coincided with decreased decay of chaperone transcripts and increased translation of chaperone proteins. Overall, these findings establish a potential mechanism by which dTrmt10A regulates the acute brain stress response through m6A modification.

Microcomputed tomography staging of bone histolysis in the regenerating mouse digit.

Humans and mice have the ability to regenerate the distal digit tip, the terminal phalanx (P3) in response to amputation. What distinguishes P3 regeneration from regenerative failure is formation of the blastema, a proliferative structure that undergoes morphogenesis to regenerate the amputated tissues. P3 regeneration is characterised by the phases of inflammation, tissue histolysis and expansive bone degradation with simultaneous blastema formation, wound closure and finally blastemal differentiation to restore the amputated structures. While each regenerating digit faithfully progresses through all phases of regeneration, phase progression has traditionally been delineated by time, that is, days postamputation (DPA), yet there is widespread variability in the timing of the individual phases. To diminish variability between digits during tissue histolysis and blastema formation, we have established an in-vivo method using microcomputed tomography (micro CT) scanning to identify five distinct stages of the early regeneration response based on anatomical changes of the digit stump. We report that categorising the initial phases of digit regeneration by stage rather than time greatly diminishes the variability between digits with respect to changes in bone volume and length. Also, stages correlate with the levels of cell proliferation, osteoclast recruitment and osteoprogenitor cell recruitment. Importantly, micro CT staging provides a means to estimate open versus closed digit wounds. We demonstrate two spatially distinct and stage specific bone repair/regeneration responses that occur during P3 regeneration. Collectively, these studies showcase the utility of micro CT imaging to infer the composition of radiolucent soft tissues during P3 blastema formation. Specifically, the staging system identifies the onset of cell proliferation, osteoclastogenesis, osteoprogenitor recruitment, the spatial initiation of de novo bone formation and epidermal closure.

Hunting for the cause: Evidence for prion-like mechanisms in Huntington's disease.

The hypothesis that pathogenic protein aggregates associated with neurodegenerative diseases spread from cell-to-cell in the brain in a manner akin to infectious prions has gained substantial momentum due to an explosion of research in the past 10-15 years. Here, we review current evidence supporting the existence of prion-like mechanisms in Huntington's disease (HD), an autosomal dominant neurodegenerative disease caused by expansion of a CAG repeat tract in exon 1 of the huntingtin (HTT) gene. We summarize information gained from human studies and in vivo and in vitro models of HD that strongly support prion-like features of the mutant HTT (mHTT) protein, including potential involvement of molecular features of mHTT seeds, synaptic structures and connectivity, endocytic and exocytic mechanisms, tunneling nanotubes, and nonneuronal cells in mHTT propagation in the brain. We discuss mechanisms by which mHTT aggregate spreading and neurotoxicity could be causally linked and the potential benefits of targeting prion-like mechanisms in the search for new disease-modifying therapies for HD and other fatal neurodegenerative diseases.

Low bone mass and impaired fracture healing in mouse models of Trisomy21 (Down syndrome).

Individuals with Down syndrome (DS), the result of trisomy of human chromosome Hsa21 (Ts21), present with an array of skeletal abnormalities typified by altered craniofacial features, short stature and low bone mineral density (BMD). While bone deficits progress with age in both sexes, low bone mass is more pronounced in DS men than women and osteopenia appears earlier. In the current study, the reproductive hormone status (FSH, LH, testosterone) of 17 DS patients (males, ages range 19-52 years) was measured. Although testosterone was consistently low, the hypothalamic-pituitary-gonadal axis was intact with corresponding rises in FSH and LH. To provide further insight into the heterogeneity of the bone mass in DS, the skeletal phenotypes of three of the most used murine DS models, Ts65Dn (Ts65), TC1, and Dp16(Yey1) (Dp16) were characterized and contrasted. Evaluation of the bone phenotype of both male and female 3-month-old Dp16 mice demonstrated sexual dimorphism, with low bone mass apparent in males, as it is in Ts65, but not in female Dp16. In contrast, male TC1 mice had no apparent bone phenotype. To determine whether low bone mass in DS impacted fracture healing, fractures of the middle phalanx (P2) digits were generated in both male and female Dp16 mice at 15 weeks of age, an age where the sexually dimorphic low BMD persisted. Fracture healing was assessed via in vivo microCT over (13 weeks) 93 days post fracture (DPF). At 93 DPF, 0 % of DS male (n = 12) or female (n = 8) fractures healed, compared to 50 % of the male (n = 28) or female (n = 8) WT littermate fractures. MicroCT revealed periosteal unbridged mineralized callus formation across the fracture gap in Dp16 mice, which was confirmed by subsequent histology. These studies provide the first direct evidence of significantly impaired fracture healing in the setting of DS.

Digit specific denervation does not inhibit mouse digit tip regeneration.

It is long-established that innervation-dependent production of neurotrophic factors is required for blastema formation and epimorphic regeneration of appendages in fish and amphibians. The regenerating mouse digit tip and the human fingertip are mammalian models for epimorphic regeneration, and limb denervation in mice inhibits this response. A complicating issue of limb denervation studies in terrestrial vertebrates is that the experimental models also cause severe paralysis therefore impairing appendage use and diminishing mechanical loading of the denervated tissues. Thus, it is unclear whether the limb denervation impairs regeneration via loss of neurotrophic signaling or loss of mechanical load, or both. Herein, we developed a novel surgical procedure in which individual digits were specifically denervated without impairing ambulation and mechanical loading. We demonstrate that digit specific denervation does not inhibit but attenuates digit tip regeneration, in part due to a delay in wound healing. However, treating denervated digits with a wound dressing that enhances closure results in a partial rescue of the regeneration response. Contrary to the current understanding of mammalian epimorphic regeneration, these studies demonstrate that mouse digit tip regeneration is not peripheral nerve dependent, an observation that should inform continued mammalian regenerative medicine approaches.

Hyaline cartilage differentiation of fibroblasts in regeneration and regenerative medicine.

Amputation injuries in mammals are typically non-regenerative; however, joint regeneration is stimulated by BMP9 treatment, indicating the presence of latent articular chondrocyte progenitor cells. BMP9 induces a battery of chondrogenic genes in vivo, and a similar response is observed in cultures of amputation wound cells. Extended cultures of BMP9-treated cells results in differentiation of hyaline cartilage, and single cell RNAseq analysis identified wound fibroblasts as BMP9 responsive. This culture model was used to identify a BMP9-responsive adult fibroblast cell line and a culture strategy was developed to engineer hyaline cartilage for engraftment into an acutely damaged joint. Transplanted hyaline cartilage survived engraftment and maintained a hyaline cartilage phenotype, but did not form mature articular cartilage. In addition, individual hypertrophic chondrocytes were identified in some samples, indicating that the acute joint injury site can promote osteogenic progression of engrafted hyaline cartilage. The findings identify fibroblasts as a cell source for engineering articular cartilage and establish a novel experimental strategy that bridges the gap between regeneration biology and regenerative medicine.

A study to investigate undergraduate diagnostic radiographer preferences and expectations of clinical role development: Quantitative findings.

INTRODUCTION: Whilst United Kingdom (UK) student ambitions for role development have been surveyed previously, no literature has explored their specialisation preferences. This study aimed to explore these ambitions and preferences in final year diagnostic radiography undergraduates at a Higher-Education Institute (HEI) in the North-West of England. METHODS: University ethical approval was granted for a survey-based study. A questionnaire consisting of 4 closed questions and 6 open questions was distributed in paper format after a taught session. Responses were collated and summarised in Excel (descriptive statistics), and transferred into SPSS (inferential statistics). RESULTS: The response rate was 75.6% (n = 34/45). Respondents were predominantly female (73.5%), had A-level as their highest qualification (79.4%) and were of 'school-leaver' age (76.5%) at the start of the degree. By overall total, preferences were for reporting (n = 24/101; 23.8%), computed tomography (CT) (n = 20/101; 19.8%) and MRI/ultrasound (both 12/101; 12.5%). CT had more first choices (n = 8) than reporting (n = 7). 73.5% anticipated specialising in less than 2 years, and 100% within 4 years. CONCLUSION: Other than a larger percentage having A-level as their highest qualification, the participant demographics were similar to the UK radiography workforce. Reporting, CT, MRI and ultrasound are the specialisation preferences of final year undergraduate diagnostic radiography students. Expectations for the timeline of role development were slightly more ambitious than previously found. IMPLICATIONS FOR PRACTICE: Identification of reporting as the preferred area of specialisation is a novel finding in the context of UK HEIs. Harnessing this ambition will help meet the goals of successive government policy. Ensuring the ambitions of graduate diagnostic radiographers can be satisfied has clear implications for staff retention within the NHS.

Mouse Digit Tip Regeneration Is Mechanical Load Dependent.

Amputation of the mouse digit tip results in blastema-mediated regeneration. In this model, new bone regenerates de novo to lengthen the amputated stump bone, resulting in a functional replacement of the terminal phalangeal element along with associated non-skeletal tissues. Physiological examples of bone repair, such as distraction osteogenesis and fracture repair, are well known to require mechanical loading. However, the role of mechanical loading during mammalian digit tip regeneration is unknown. In this study, we demonstrate that reducing mechanical loading inhibits blastema formation by attenuating bone resorption and wound closure, resulting in the complete inhibition of digit regeneration. Mechanical unloading effects on wound healing and regeneration are completely reversible when mechanical loading is restored. Mechanical unloading after blastema formation results in a reduced rate of de novo bone formation, demonstrating mechanical load dependence of the bone regenerative response. Moreover, enhancing the wound-healing response of mechanically unloaded digits with the cyanoacrylate tissue adhesive Dermabond improves wound closure and partially rescues digit tip regeneration. Taken together, these results demonstrate that mammalian digit tip regeneration is mechanical load-dependent. Given that human fingertip regeneration shares many characteristics with the mouse digit tip, these results identify mechanical load as a previously unappreciated requirement for de novo bone regeneration in humans. © 2021 American Society for Bone and Mineral Research (ASBMR).

Early prognosis of respiratory virus shedding in humans.

This paper addresses the development of predictive models for distinguishing pre-symptomatic infections from uninfected individuals. Our machine learning experiments are conducted on publicly available challenge studies that collected whole-blood transcriptomics data from individuals infected with HRV, RSV, H1N1, and H3N2. We address the problem of identifying discriminatory biomarkers between controls and eventual shedders in the first 32 h post-infection. Our exploratory analysis shows that the most discriminatory biomarkers exhibit a strong dependence on time over the course of the human response to infection. We visualize the feature sets to provide evidence of the rapid evolution of the gene expression profiles. To quantify this observation, we partition the data in the first 32 h into four equal time windows of 8 h each and identify all discriminatory biomarkers using sparsity-promoting classifiers and Iterated Feature Removal. We then perform a comparative machine learning classification analysis using linear support vector machines, artificial neural networks and Centroid-Encoder. We present a range of experiments on different groupings of the diseases to demonstrate the robustness of the resulting models.

Patient and radiographer acceptability of prophylactic skin care for breast patients receiving radiotherapy.

INTRODUCTION: This study aimed to: • Address the lack of information surrounding patient preference within radiotherapy skin care. • Identify if prophylactic skin care is the preferred approach of patients and staff. • Establish if patients and staff are accepting of the use of a type of barrier film, such as 3M™ Cavilon™ No Sting Barrier Film. METHODS: Twelve patients undergoing standard whole breast radiotherapy and four staff members who were based mainly on a breast-specific treatment unit were interviewed using semi-structured techniques. The interview transcripts were coded for areas of interest and a thematic map generated using the qualitative data analysis software (NVivo V12, QSR International). RESULTS: One Hundred percent of patients (n = 12) would have preferred a proactive approach to skin care management over the reactive one currently implemented. Staff were also in favour of a proactive approach to skin care with 100% (n = 4) supportive of a trial into the film's effectiveness. Three key themes were identified: • Theme 1: Patient Ownership of Own care - all patients identified they preferred a prophylactic approach and that more specific skin care guidance from healthcare professionals would be beneficial. • Theme 2: Product Practicality - 93% of patients and 100% of staff accepted the product and would be open to the use of it clinically. • Theme 3: Staff Acknowledgement of Skin Care - all staff identified a patient group in need of prophylaxis and that Cavilon No Sting may be a product of interest. CONCLUSION: Patients and staff were in support of prophylactic skin care, both approved of the proposed product. However, there is a significant lack of clinical evidence to support the use of any topical products within radiotherapy skincare due to the lack of high-quality studies. IMPLICATIONS FOR PRACTICE: Changes to skin care practice could be considered due to patient preference in favour of proactive management.

Bio-processing of macroalgae Palmaria palmata: metabolite fractionation from pressed fresh material and ensiling considerations for long-term storage.

Red algae, belonging to the phylum Rhodophyta, contain an abundance of useful chemicals including bioactive molecules and present opportunities for the production of different products through biorefinery cascades. The rhodophyte Palmaria palmata, commonly termed dulse or dillisk, grows predominantly on the northern coasts of the Atlantic and Pacific Oceans and is a well-known snack food. Due to its abundance, availability and cultivation capacity, P. palmata was selected for study as a potential candidate for a biorefinery process. In addition to studying juice and solid fractions of freshly harvested P. palmata, we have investigated the novel possibility of preserving algal biomass by ensilaging protocols similar to those employed for terrestrial forage crops. In the metabolite partitioning within the solid and liquid fractions following screw-pressing, the majority of the metabolites screened for-water soluble carbohydrates, proteins and amino acids, lipids, pigments, phenolics and antioxidant activity-remained in the solid fraction, though at differing proportions depending on the metabolite, from 70.8% soluble amino acids to 98.2% chlorophyll a and 98.1% total carotenoids. For the ensiling study, screw-pressed P. palmata, with comparative wilted and chopped, and chopped only samples, were ensiled at scale with and without Safesil silage additive. All samples were successfully ensiled after 90 days, with screw-pressing giving lower or equal pH before and after ensiling compared with the other preparations. Of particular note was the effluent volumes generated during ensiling: 26-49% of the fresh weight, containing 16-34% of the silage dry matter. This may be of advantage depending on the final use of the biomass.

Radiotherapy-specific interprofessional learning through simulation.

INTRODUCTION: Interprofessional learning (IPL) is a vital aspect of training in radiation oncology professions, yet is rarely delivered to those professionals who work most closely together in clinical practice. Scenario-based learning using simulation facilities provides a unique opportunity to facilitate this learning and this project aimed to determine the impact and value of this initiative. METHODS: Small groups comprising post-graduate diploma pre-registration therapeutic radiographers, medical physics trainees and radiation oncology registrars were challenged with 4 plausible and challenging radiotherapy scenarios within an academic simulation centre. Pre- and post-event completion of the "Readiness for Interprofessional Learning Scale" measured impact and a Likert-style survey gathered feedback from participants. RESULTS: The session increased participants' teamwork and collaboration skills as well as strengthening professional identities. Participants reported high levels of enjoyment related to collaborative working, communication and observing other professionals deploying their technical skills and specialist knowledge. CONCLUSION: Although beneficial, simulated scenarios offering equal opportunities for engagement across the professions are challenging to plan and timetabling issues between the 3 groups present significant difficulties. The safe environment and unique opportunity for these groups to learn together was particularly well received and future oncology-specific simulated scenario sessions are planned with larger cohorts. IMPLICATIONS FOR PRACTICE: Simulated scenario training can be used to improve team working across the radiotherapy interprofessional team and may have wider use in other specialist interdisciplinary team development.

Development and Validation Clinician and Patient Reported Photonumeric Scales to Assess Buttocks Cellulite Severity.

BACKGROUND: The Clinician Reported Photonumeric Cellulite Severity Scale (CR-PCSS) and Patient Reported PCSS (PR-PCSS) are newly developed tools for assessing cellulite severity. OBJECTIVE: To report on the reliability, validity, and ability to detect a change in cellulite severity on the buttocks of adult women with the CR-PCSS and PR-PCSS. MATERIALS AND METHODS: Content validity of both scales was established through concept elicitation and cognitive interviews. Test-retest reliability was evaluated, and intra-rater (both scales) and inter-rater (CR-PCSS only) reliability were estimated using intraclass correlation coefficients (ICCs) for agreement and consistency. Ability to detect a change was determined using the Subject-Global Aesthetic Improvement Scale (GAIS) or Investigator-GAIS as anchors. RESULTS: For the CR-PCSS (n = 6) at baseline and Day 2, the mean interrater ICCs were ≥0.70 and mean intrarater ICCs (95% confidence interval [CI]) were ≥0.81 (0.72-0.90) for both buttocks. For the PR-PCSS (n = 99) at baseline and Day 14, the mean test-retest reliability ICCs (95% CI) were ≥0.86 (0.79-0.91) for both buttocks. A clinically meaningful change was 1.0 point on the PR-PCSS and 1.0 on the CR-PCSS. CONCLUSION: The CR-PCSS and PR-PCSS reliably assess cellulite severity of the buttocks and can detect a clinically meaningful change after treatment for cellulite.

Phagocytic glia are obligatory intermediates in transmission of mutant huntingtin aggregates across neuronal synapses.

Emerging evidence supports the hypothesis that pathogenic protein aggregates associated with neurodegenerative diseases spread from cell to cell through the brain in a manner akin to infectious prions. Here, we show that mutant huntingtin (mHtt) aggregates associated with Huntington disease transfer anterogradely from presynaptic to postsynaptic neurons in the adult Drosophila olfactory system. Trans-synaptic transmission of mHtt aggregates is inversely correlated with neuronal activity and blocked by inhibiting caspases in presynaptic neurons, implicating synaptic dysfunction and cell death in aggregate spreading. Remarkably, mHtt aggregate transmission across synapses requires the glial scavenger receptor Draper and involves a transient visit to the glial cytoplasm, indicating that phagocytic glia act as obligatory intermediates in aggregate spreading between synaptically-connected neurons. These findings expand our understanding of phagocytic glia as double-edged players in neurodegeneration-by clearing neurotoxic protein aggregates, but also providing an opportunity for prion-like seeds to evade phagolysosomal degradation and propagate further in the brain.

Simulated versus traditional therapeutic radiography placements: A randomised controlled trial.

INTRODUCTION: Clinical placements provide rich learning environments for health professional pre-registration education but add significant workload pressure to clinical departments. Advances in simulation approaches mean that many aspects of students' clinical learning can be undertaken in the academic environment. There is, however, little data identifying specific pedagogical gains afforded by simulation compared to clinical placement. This study measured the impact of a comprehensive integrated simulation placement on student clinical skill acquisition. METHODS: A virtual department was developed using a range of simulation equipment and software, with actors and service users providing a range of patients for students to engage with. A cohort of 29 first-year undergraduate therapeutic radiography students were randomly assigned to either simulated or conventional clinical placement. Clinical skills assessment scores provided by a blinded assessor were then compared. RESULTS: Mean overall assessment scores for each cohort were within 3% of each other. The simulation cohort had over 10% higher "communication" scores than the traditional group (p = 0.028). The ability to gain both technical and interpersonal skills simultaneously improved learning compared to clinical placement. Students valued the structured approach of the simulated placement and the opportunity to practice techniques in a safe unpressured environment. CONCLUSION: An integrated simulated placement can help students to achieve clinical learning outcomes and lead to improved interpersonal skills. IMPLICATIONS FOR PRACTICE: Use of blended simulation resources can enable students to acquire technical, procedural and interpersonal skills which in turn may enable reduction of overall clinical placement time and departmental training burden.

Efficacy, Safety, and Durability of Response of Collagenase Clostridium Histolyticum-aaes for Treating Cellulite.

Collagenase clostridium histolyticum-aaes (CCH) enzymatically releases fibrous septa that contribute to the skin dimpling characteristic of cellulite. Long-term safety/duration of efficacy (durability) results from an open-label extension (OLE) of a randomized, double-blind, placebo-controlled trial (RCT) evaluating CCH efficacy/safety for moderate-to-severe cellulite of the buttocks or posterolateral thighs in women was assessed. Efficacy/safety of CCH treatment/retreatment during OLE was also evaluated. METHODS: After RCT unblinding, women could enroll in OLE for assessment of long-term CCH durability (observation only, up to day 720) or CCH treatment/retreatment, the latter in women with moderate-to-severe buttock/posterolateral thigh cellulite [Clinician Reported Photonumeric Cellulite Severity Scale (CR-PCSS) and Patient Reported PCSS (PR-PCSS) scores of 3/4; Hexsel Cellulite Severity Scale score ≤13]. A treatment/retreatment course comprised 1 or 2 courses of 3 sessions (0.84-mg CCH injected at days 1, 22, and 43). CCH efficacy/safety was assessed at baseline, days 22, 43, 71, and quarterly at day 360. RESULTS: Of the 259 OLE participants, 53 were observed for long-term CCH durability. For those who were ≥2-level composite responders during RCT (≥2-point CR-PCSS/PR-PCSS score improvements), CCH effect was durable (scores did not reach RCT baseline levels) in all women on days 180 (19/19), 360 (16/16), and 720 (7/7). Of the 200 women receiving CCH treatment/retreatment, more than 75% had ≥1-level improvement in patient and clinical assessments at day 71. The most common adverse events were injection-site bruising and pain. CONCLUSIONS: CCH treatment provided durable improvement in moderate-to-severe buttock/thigh cellulite and was generally well tolerated. Repeated CCH exposure did not increase adverse event risk or reduce efficacy.

Destruction of Staphylococcus aureus and the impact of chlortetracycline on biomethane production during anaerobic digestion of chicken manure.

Research was undertaken to ascertain the effect on biogas potential during the anaerobic digestion of chicken manure containing Staphylococcus aureus and chlortetracycline (antibiotic) from infected chicken flocks. S. aureus is a pathogenic bacteria in chicken flocks that is usually treated with the broad-spectrum antibiotic, chlortetracycline. Veterinary antibiotics are often prescribed in the poultry sector for on-farm use at the flock level to control disease; consequently, significant quantities of antibiotics are excreted from the bird into the manure. Subsequent anaerobic digestion of this chicken manure could lead to pathogens and antibiotics affecting the digestion process. Anaerobic digestion biochemical methane potential assays were completed at 35°C for 39 days, with some assays receiving S. aureus and some receiving S. aureus and chlortetracycline. No viable S. aureus cells were detected after Day 0 of the experiment. A further experiment utilising an order of magnitude greater concentration of S. aureus demonstrated a significant reduction (>400 fold) in S. aureus within 24 h when inoculated into anaerobic digestate, with no viable S. aureus cells detected by the end of 3 days. Furthermore, the efficacy of chlortetracycline was significantly reduced when applied to anaerobic digestate compared to water alone. Total biogas yields from chicken manure were significantly lowered by the addition of S. aureus, with and without chlortetracycline. However, there was no significant difference in methane yields between treatments. The cellulose control assays showed a lag phase in methane production after receiving chlortetracycline. In comparison, the absence of a lag phase when the antibiotic were added to chicken manure may have been due to the relatively high nitrogen content of the feedstock reducing the inhibition of chlortetracycline on methanogens. Therefore, this study demonstrates that the addition of S. aureus and chlortetracycline does not have a commercially relevant effect on the digestion of chicken manure.

Social defeat-induced Cingulate gyrus immediate-early gene expression and anxiolytic-like effect depend upon social rank.

Social hierarchy is considered to impart an adaptive advantage to the species by reducing long-term conflict between conspecifics. While social stratification is frequently established via stress-inducing stimuli, the subsequent integration of individuals into the hierarchy may attenuate anxiety. Presently, we hypothesized that repeated reinforcement of murine social hierarchy in the dominant-submissive relationship (DSR) food-competition test would engender divergent neuroplastic changes mediating both social and anxiety-like behavior among selectively-bred Dominant (Dom) and Submissive (Sub) mice. Two weeks of repeated respective social victory or defeat reduced serum corticosterone levels of both Dom and Sub mice, whereas socially-defeated Sub mice demonstrated markedly greater exploration of the open arms of the elevated plus maze (EPM). At the same time, social victory led to markedly greater expression of the immediate-early genes (IEGs) c-Jun and EGR-1 in the lateral septal nucleus (LSN) among Dom mice, in contrast with defeated Sub counterparts which demonstrated four-fold greater IEG expression in the cingulate gyrus (Cg). These findings point towards involvement of the Cg in the anxiety-like effect among Sub mice after repeated social defeat, and suggest stabilization of the social hierarchy to attenuate the stress-inducing nature of social interaction, particularly for subordinates. Further study of the potentially anxiolytic-like effects of Cg activity should shed light upon the functional significance of the Cg in social interaction, social hierarchical sorting and anxiety.

Monitoring Cell-to-cell Transmission of Prion-like Protein Aggregates in Drosophila Melanogaster.

Protein aggregation is a central feature of most neurodegenerative diseases, including Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), and amyotrophic lateral sclerosis (ALS). Protein aggregates are closely associated with neuropathology in these diseases, although the exact mechanism by which aberrant protein aggregation disrupts normal cellular homeostasis is not known. Emerging data provide strong support for the hypothesis that pathogenic aggregates in AD, PD, HD, and ALS have many similarities to prions, which are protein-only infectious agents responsible for the transmissible spongiform encephalopathies. Prions self-replicate by templating the conversion of natively-folded versions of the same protein, causing spread of the aggregation phenotype. How prions and prion-like proteins in AD, PD, HD, and ALS move from one cell to another is currently an area of intense investigation. Here, a Drosophila melanogaster model that permits monitoring of prion-like, cell-to-cell transmission of mutant huntingtin (Htt) aggregates associated with HD is described. This model takes advantage of powerful tools for manipulating transgene expression in many different Drosophila tissues and utilizes a fluorescently-tagged cytoplasmic protein to directly report prion-like transfer of mutant Htt aggregates. Importantly, the approach we describe here can be used to identify novel genes and pathways that mediate spreading of protein aggregates between diverse cell types in vivo. Information gained from these studies will expand the limited understanding of the pathogenic mechanisms that underlie neurodegenerative diseases and reveal new opportunities for therapeutic intervention.