Adeno-associated virus-8-Mediated intravenous transfer of myostatin propeptide leads to systemic functional improvements of slow but not fast muscle

Myostatin is a member of the transformating growth factor-_ (TGF-_) superfamily of proteins and is produced almost exclusively in skeletal muscle tissue, where it is secreted and circulates as a serum protein. Myostatin acts as a negative regulator of muscle mass through the canonical SMAD2/3/4 signaling pathway. Naturally occurring myostatin mutants exhibit a ‘double muscling’ phenotype in which muscle mass is dramatically increased as a result of both hypertrophy and hyperplasia. Myostatin is naturally inhibited by its own propeptide; therefore, we assessed the impact of adeno associated virus-8 (AAV8) myostatin propeptide vectors when systemically introduced in MF-1 mice. We noted a significant systemic increase in muscle mass in both slow and fast muscle phenotypes, with no evidence of hyperplasia; however, the nuclei-to- cytoplasm ratio in all myofiber types was significantly reduced. An increase in muscle mass in slow (soleus) muscle led to an increase in force output; however, an increase in fast (extensor digitorum longus [EDL]) muscle mass did not increase force output. These results suggest that the use of gene therapeutic regimens of myostatin inhibition for age-related or disease-related muscle loss may have muscle-specific effects

Serum Concentrations of Myostatin and Myostatin-Interacting Proteins do not differ between young and Scarcopenic elderly men

Peer reviewedPostprin

Utility of Common Bile Duct Identification on Biliary Ultrasound in Emergency Department Patients

Christopher Thom, Justin Yaworsky, Kevin Livingstone, David Han, Jakob Ottenhoff Department of Emergency Medicine, University of Virginia Health System, Charlottesville, Virginia, USACorrespondence: Christopher Thom, University of Virginia Health System, 1215 Lee Street, Charlottesville, Virginia, 22903, USA, Email [email protected]: Biliary ultrasound is often utilized in the evaluation of abdominal pain in the Emergency Department (ED). Common bile duct (CBD) identification is traditionally a standard component of the biliary ultrasound examination but can be challenging to perform for the novice sonographer. Previous work has demonstrated that CBD dilatation is rare in cases of cholecystitis with normal liver function tests (LFTs). We sought to assess the frequency of CBD dilatation in the subset of ED patients undergoing hepatobiliary ultrasound who have normal LFTs and an absence of gallstones or biliary sludge on ultrasound. We also performed an assessment of changes in CBD diameter by age and cholecystectomy status.Methods: This was a retrospective chart review at a single academic ED. Patients were enrolled in the study if they underwent a radiology performed (RP) hepatobiliary ultrasound within the 2 year study period. Records were reviewed for the presence of gallstones or sludge, CBD diameter, age, clinical indication for the ultrasound, and LFTs. Descriptive analyses were performed, and interobserver agreement among data abstractors was assessed by K analysis for the presence of CBD dilatation. The Mann–Whitney test was utilized to assess statistical significance in the comparison of differences between CBD diameters amongst age groups.Results: Of 1929 RP hepatobiliary ultrasounds performed in the study period, 312 were excluded and 1617 met inclusion criteria. Amongst these, there were 506 patients who had normal LFTs and an ultrasound with no stones or sludge. Ten patients within this group had a dilated CBD > 7 mm (1.98%, 95% CI of 1.08% to 3.6%). We also noted a statistically significant increase in CBD size in the older age cohort and in those individuals with a history of cholecystectomy.Conclusion: CBD dilation in ED patients who present with normal LFTs and an absence of gallstones and biliary sludge is rare. Physicians should be reassured that the routine identification of the CBD on ultrasound in this setting is of low yield and need not be pursued.Plain Language Summary: The common bile duct is often taught as part of the biliary point-of-care ultrasound examination. However, it is more challenging to identify than the gallbladder and thus may limit adoption of POCUS by ED physicians. Our study adds to the body of work demonstrating that omitting the common bile duct from an ultrasound evaluation is likely reasonable when both the gallbladder and liver function tests are normal. Our study also adds to the literature regarding the increase in common bile duct size with age and with post-cholecystectomy status.Keywords: biliary, common bile duct, ultrasound, gallstones, cholelithiasis, point-of-care ultrasoun

Priority areas for vulture conservation in the Horn of Africa largely fall outside the protected area network

Vulture populations are in severe decline across Africa and prioritization of geographic areas for their conservation is urgently needed. To do so, we compiled three independent datasets on vulture occurrence from road-surveys, GPS-tracking, and citizen science (eBird), and used maximum entropy to build ensemble species distribution models (SDMs). We then identified spatial vulture conservation priorities in Ethiopia, a stronghold for vultures in Africa, while accounting for uncertainty in our predictions. We were able to build robust distribution models for five vulture species across the entirety of Ethiopia, including three Critically Endangered, one Endangered, and one Near Threatened species. We show that priorities occur in the highlands of Ethiopia, which provide particularly important habitat for Bearded Gypaetus barbatus, Hooded Necrosyrtes monachus, Ruppell's Gyps ruppelli and White-backed Gyps africanus Vultures, as well as the lowlands of north-eastern Ethiopia, which are particularly valuable for the Egyptian Vulture Neophron percnopterus. One-third of the core distribution of the Egyptian Vulture was protected, followed by the White-backed Vulture at one-sixth, and all other species at one-tenth. Overall, only about one-fifth of vulture priority areas were protected. Given that there is limited protection of priority areas and that vultures range widely, we argue that measures of broad spatial and legislative scope will be necessary to address drivers of vulture declines, including poisoning, energy infrastructure, and climate change, while considering the local social context and aiding sustainable development.Peer reviewe

High-Density Microwell Chip for Culture and Analysis of Stem Cells

With recent findings on the role of reprogramming factors on stem cells, in vitro screening assays for studying (de)-differentiation is of great interest. We developed a miniaturized stem cell screening chip that is easily accessible and provides means of rapidly studying thousands of individual stem/progenitor cell samples, using low reagent volumes. For example, screening of 700,000 substances would take less than two days, using this platform combined with a conventional bio-imaging system. The microwell chip has standard slide format and consists of 672 wells in total. Each well holds 500 nl, a volume small enough to drastically decrease reagent costs but large enough to allow utilization of standard laboratory equipment. Results presented here include weeklong culturing and differentiation assays of mouse embryonic stem cells, mouse adult neural stem cells, and human embryonic stem cells. The possibility to either maintain the cells as stem/progenitor cells or to study cell differentiation of stem/progenitor cells over time is demonstrated. Clonality is critical for stem cell research, and was accomplished in the microwell chips by isolation and clonal analysis of single mouse embryonic stem cells using flow cytometric cell-sorting. Protocols for practical handling of the microwell chips are presented, describing a rapid and user-friendly method for the simultaneous study of thousands of stem cell cultures in small microwells. This microwell chip has high potential for a wide range of applications, for example directed differentiation assays and screening of reprogramming factors, opening up considerable opportunities in the stem cell field

Brain injury-associated biomarkers of TGF-beta1, S100B, GFAP, NF-L, tTG, AbetaPP, and tau were concomitantly enhanced and the UPS was impaired during acute brain injury caused by Toxocara canis in mice

BACKGROUND: Because the outcomes and sequelae after different types of brain injury (BI) are variable and difficult to predict, investigations on whether enhanced expressions of BI-associated biomarkers (BIABs), including transforming growth factor beta1 (TGF-beta1), S100B, glial fibrillary acidic protein (GFAP), neurofilament light chain( NF-L), tissue transglutaminases (tTGs), beta-amyloid precursor proteins (AbetaPP), and tau are present as well as whether impairment of the ubiquitin-proteasome system (UPS) is present have been widely used to help delineate pathophysiological mechanisms in various BIs. Larvae of Toxocara canis can invade the brain and cause BI in humans and mice, leading to cerebral toxocariasis (CT). Because the parasitic burden is light in CT, it may be too cryptic to be detected in humans, making it difficult to clearly understand the pathogenesis of subtle BI in CT. Since the pathogenesis of murine toxocariasis is very similar to that in humans, it appears appropriate to use a murine model to investigate the pathogenesis of CT. METHODS: BIAB expressions and UPS function in the brains of mice inoculated with a single dose of 250 T. canis embryonated eggs was investigated from 3 days (dpi) to 8 weeks post- infection (wpi) by Western blotting and RT-PCR. RESULTS: Results revealed that at 4 and 8 wpi, T. canis larvae were found to have invaded areas around the choroid plexus but without eliciting leukocyte infiltration in brains of infected mice; nevertheless, astrogliosis, an indicator of BI, with 78.9~142.0-fold increases in GFAP expression was present. Meanwhile, markedly increased levels of other BIAB proteins including TGF-beta1, S100B, NF-L, tTG, AbetaPP, and tau, with increases ranging 2.0~12.0-fold were found, although their corresponding mRNA expressions were not found to be present at 8 wpi. Concomitantly, UPS impairment was evidenced by the overexpression of conjugated ubiquitin and ubiquitin in the brain. CONCLUSION: Further studies are needed to determine whether there is an increased risk of CT progression into neurodegenerative disease because neurodegeneration-associated AbetaPP and phosphorylated tau emerged in the brain. DOI: 10.1186/1471-2334-8-8

‘In vivo’ optical approaches to angiogenesis imaging

In recent years, molecular imaging gained significant importance in biomedical research. Optical imaging developed into a modality which enables the visualization and quantification of all kinds of cellular processes and cancerous cell growth in small animals. Novel gene reporter mice and cell lines and the development of targeted and cleavable fluorescent “smart” probes form a powerful imaging toolbox. The development of systems collecting tomographic bioluminescence and fluorescence data enabled even more spatial accuracy and more quantitative measurements. Here we describe various bioluminescent and fluorescent gene reporter models and probes that can be used to specifically image and quantify neovascularization or the angiogenic process itself