Substrate Stiffness Controls Osteoblastic and Chondrocytic Differentiation of Mesenchymal Stem Cells without Exogenous Stimuli

Stem cell fate has been linked to the mechanical properties of their underlying substrate, affecting mechanoreceptors and ultimately leading to downstream biological response. Studies have used polymers to mimic the stiffness of extracellular matrix as well as of individual tissues and shown mesenchymal stem cells (MSCs) could be directed along specific lineages. In this study, we examined the role of stiffness in MSC differentiation to two closely related cell phenotypes: osteoblast and chondrocyte. We prepared four methyl acrylate/methyl methacrylate (MA/MMA) polymer surfaces with elastic moduli ranging from 0.1 MPa to 310 MPa by altering monomer concentration. MSCs were cultured in media without exogenous growth factors and their biological responses were compared to committed chondrocytes and osteoblasts. Both chondrogenic and osteogenic markers were elevated when MSCs were grown on substrates with stiffnesschondrocytes, MSCs on lower stiffness substrates showed elevated expression of ACAN, SOX9, and COL2 and proteoglycan content; COMP was elevated in MSCs but reduced in chondrocytes. Substrate stiffness altered levels of RUNX2 mRNA, alkaline phosphatase specific activity, osteocalcin, and osteoprotegerin in osteoblasts, decreasing levels on the least stiff substrate. Expression of integrin subunits α1, α2, α5, αv, β1, and β3 changed in a stiffness- and cell type-dependent manner. Silencing of integrin subunit beta 1 (ITGB1) in MSCs abolished both osteoblastic and chondrogenic differentiation in response to substrate stiffness. Our results suggest that substrate stiffness is an important mediator of osteoblastic and chondrogenic differentiation, and integrin β1 plays a pivotal role in this process

Neutrophil extracellular traps in stored canine red blood cell units

BackgroundNeutrophil extracellular traps (NETs), webs of DNA and citrullinated histones extruded from activated neutrophils cause transfusion‐related acute lung injury. Supernatants of stored red blood cell (RBC) units might promote NETosis in neutrophils from the units or from transfusion recipients.Hypotheses(1) NETs form during storage of canine RBC, (2) leukoreduction (LR) before storage of RBC reduces NETosis, and (3) supernatant from stored, nonleukoreduced (NLR) RBC units induces NETosis in healthy canine neutrophils modeling transfusion recipients.AnimalsSix healthy purpose‐bred research dogs were utilized for blood donation.MethodsProspective controlled study. RBC units were collected from each dog, aseptically divided into 2 equal subunits, 1 of which was leukoreduced, and stored for 42 days. Stored units were sampled biweekly for quantification of NET markers citrullinated histone H3 (Western blot) and cell‐free DNA (cfDNA) (DNA dye binding). Unit supernatants were applied ex vivo to canine neutrophils and extracellular DNA release representing NETosis was assessed.ResultsMarkers of NETs increased during RBC storage (cfDNA P < .0001 and citrullinated H3 P = .0002) and were higher in NLR than LR units (day 42 LR cfDNA 0.34 ± 0.82 ng/mL vs day 42 NLR 1361.07 ± 741.00 ng/mL, P < .0001; day 42 LR citrullinated H3 0.19 ± 0.13 AU vs NLR 0.57 ± 0.34 AU, P = .007). Isolated neutrophils did not form NETs when exposed to stored canine RBC supernatant.Conclusions and Clinical ImportanceNETosis occurs in stored canine NLR RBC units, and is attenuated by LR before storage. NETs might be mediators of transfusion reactions.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/162806/3/jvim15876-sup-0001-supinfo.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162806/2/jvim15876_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162806/1/jvim15876.pd

Insight into the Evolution of Anuran Foot Flag Displays: A Comparative Study of Color and Kinematics

Understanding how complex animal displays evolve is a major goal of evolutionary organismal biology. Here, we study this topic by comparing convergently evolved gestural displays in two unrelated species of frog (Bornean Rock Frog, Staurois parvus, and Kottigehara Dancing Frog, Micrixalus kottigeharensis). This behavior, known as a foot flag, is produced when a male ?waves\u27 his hindlimb at another male during bouts of competition for access to mates. We assess patterns of variation in the color of frog feet and the kinematics of the display itself to help pinpoint similarities and differences of the visual signal elements. We find clear species differences in the color of foot webbing, which is broadcast to receivers during specific phases of the display. Analyses of foot-trajectory duration and geometry also reveal clear species differences in display speed and shape - S. parvus generates a faster and more circular visual signal, while M. kottigeharensis generates a much slower and more elliptical one. These data are consistent with the notion that color, speed, and shape likely encode species identity. However, we also found that foot flag speed shows significant among-individual variation, particularly the phase of the display in which foot webbings are visible. This result is consistent with the idea that frogs alter temporal signal components, which may showcase individual condition, quality, or motivation. Overall, our comparative study helps elucidate the variability of foot flagging behavior in a manner that informs how we understand the design principles that underlie its function as a signal in intraspecific communication

Laboratory Focus on Improving the Culture of Biosafety: Statewide Risk Assessment of Clinical Laboratories That Process Specimens for Microbiologic Analysis

The Wisconsin State Laboratory of Hygiene challenged Wisconsin laboratories to examine their biosafety practices and improve their culture of biosafety. One hundred three clinical and public health laboratories completed a questionnaire-based, microbiology-focused biosafety risk assessment. Greater than 96% of the respondents performed activities related to specimen processing, direct microscopic examination, and rapid nonmolecular testing, while approximately 60% performed culture interpretation. Although they are important to the assessment of risk, data specific to patient occupation, symptoms, and travel history were often unavailable to the laboratory and, therefore, less contributory to a microbiology-focused biosafety risk assessment than information on the specimen source and test requisition. Over 88% of the respondents complied with more than three-quarters of the mitigation control measures listed in the survey. Facility assessment revealed that subsets of laboratories that claim biosafety level 1, 2, or 3 status did not possess all of the biosafety elements considered minimally standard for their respective classifications. Many laboratories reported being able to quickly correct the minor deficiencies identified. Task assessment identified deficiencies that trended higher within the general (not microbiology-specific) laboratory for core activities, such as packaging and shipping, direct microscopic examination, and culture modalities solely involving screens for organism growth. For traditional microbiology departments, opportunities for improvement in the cultivation and management of highly infectious agents, such as acid-fast bacilli and systemic fungi, were revealed. These results derived from a survey of a large cohort of small- and large-scale laboratories suggest the necessity for continued microbiology-based understanding of biosafety practices, vigilance toward biosafety, and enforcement of biosafety practices throughout the laboratory setting

Evaluation of a Direct Fed Microbial and/or an Enzymatically Hydrolyzed Yeast Product in Diets Containing Monensin Sodium on Feedlot Phase Growth Performance, Efficiency of Dietary Net Energy Utilization, and Carcass Characteristics in Newly Weaned Beef Steers Fed in Confinement for 258 Days

Study Description: Single-sourced, newly weaned steers (n = 256; initial body weight (BW) = 542 ± 3.7 lb) were allotted to 32 pens (n = 8 pens/treatment with 8 steers/pen). Steers were blocked by location in a 2x2 factorial treatment arrangement of DFM (Certillus CP B1801 Dry; Bacillus subtilis, Lactobacillus plantarum; 28 g/steer·d-1) and YCW (Celmanax; 18 g/steer·d-1). Steers were vaccinated and poured at processing and individually weighed on d 1, 14, 42 (end of receiving phase; implanted), 77, 105 (end of growing phase), 133, 161 (implanted), 182, 230 (start ractopamine HCl) and 258. Growth performance and carcass measurements were recorded

Evaluation of a Direct Fed Microbial an an Enzymatically Hydrolyzed Yeast Product Fed Alone or in Combination to Beef Steers Administered Ractopamine Hydrochloride 28 Days Prior to Harvest During Summer Months in the Northern Plains

Study Description: Single-sourced, newly weaned steers (n=256; initial BW=542 ± 3.7lb; n=64 steers/treatment; 8 steers/pen) were blocked by location in a 2×2 factorial arrangement of DFM (Certillus CP B1801 Dry; Bacillus subtilis, Lactobacillus plantarum; 28 g/steer·d-1) and YCW (Celmanax; 18 g/steer·d-1). Temperature-humidity index (THI) was calculated as: THI=0.81×ambient temperature+[relative humidity×(ambient temperature-14.40)]+46.40. On d-1 and 2 and d-21 and 22 on RH, respiration rate (RR) and panting scores (PS) were determined before and after AM and PM feedings (0700h, 1100h, 1400h, 1700h). RR (n=3 steers/pen) was calculated from: 600/seconds required for 10 flank movements. PS utilized this scoring system: 0 (not distressed) to 4.5 (severely distressed)

Dose Effects of Encapsulated Butyric Acid and Zinc on Beef Feedlot Steer Growth Performance, Carcass Characteristics, and Dietary Net Energy Utilization

Study Description: Steers (n = 272; shrunk BW = 794 ± 163 pounds) were assigned to one of four dietary treatments in a 143.5 d feedlot finishing trial: 0 g BPZ/ kg diet dry matter (DM) (CON), 1 g BPZ/ kg diet DM (1BPZ), 2 g BPZ/ kg diet DM (2BPZ), or 3 g BPZ/ kg diet DM (3BPZ). Carcass data and liver health outcomes were collected, and feedlot growth performance data and efficiency of dietary net energy utilization were calculated on a carcass-adjusted basis

Effects of On-Arrival Application of a Modified-Live Respiratory and Clostridia Vaccination on Health, Growth Performance, and Antibody Titers of Newly-Weaned Calves

Study Description: Single-sourced, newly weaned steers (n=70; initial body weight (BW)=560±12.9lb) were allotted to 10 pens (n=5 pens/treatment with 7 steers/pen). Steers were blocked by BW in a randomized complete block design of VAC [vaccinated for IBR, BVD 1 and 2, PI3, and BRSV (Bovi-Shield Gold 5, Zoetis, Parsippany, NJ) and clostridial (Ultrabec 7/Somubac, Zoetis) upon arrival] or NOVAC (not vaccinated for IBR, BVD 1 and 2, PI3, and BRSV or clostridial species upon arrival). Steers were individually weighed on d 0 (arrival), 1, 21, and 42 for growth performance measures. Whole blood samples (10 mL) were collected (n=3 steers/pen closest to the pen mean BW) on d 1, 21, and 42 via jugular venipuncture for metabolite and antibody titer responses

Mild Traumatic Brain Injury and Treatment Response in Prolonged Exposure for PTSD

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/98185/1/jts21813.pd

Dynamic and integrative approaches to understanding pathogen spillover

No abstract available