47 research outputs found
Xanthogranulomatous Inflammation of the Small Bowel in a Dog
A case of xanthogranulomatous inflammation of the small bowel in a 12-year-old male American Staffordshire Terrier is described. Disseminated yellow-white nodules 2 to 3 mm in diameter bulging on the serosal surface of the small bowel, as well as on mesenteric tissue, were detected. Histopathologic examination revealed a nodular collection of foamy cells, mainly involving serosal and muscular layers, associated with necrotic areas, hemorrhages, neovascularization, variable numbers of reactive spindle cells, neutrophils, lymphocytes, plasma cells, and rare multinucleated giant cells. Transmural lymphangectasia and mucosal lymphoplasmacytic inflammation were also observed. Both Oil Red O stain and ultrastructural study revealed lipid droplets in the cytoplasm of foamy cells. Lysozyme immunoreactivity was detected in single as well as in clustered foamy cells, while smooth muscle actin was positive in spindle cells and scattered foamy elements. Lymphangectasia associated with lymphoplasmacytic enteritis suggests a component of lymphatic fluid stasis in the pathogenesis of such lesions
reconfigurable inspection robot for industrial applications
Abstract The power generation industry, due to its importance in both general public and industrial applications, requires high standard of reliability. In the electrical power generation processes, the inspection and the adequate maintenance of the power generators are extremely important. Currently these inspection procedures are performed by dismounting the generators after a predetermined amount of operating hours. Due to the huge size and the complexity of such machines, these operations other than being time-consuming are sometimes source of mechanical and electrical damages. Furthermore, several analyses are carried on by use of manual instrumentation operated by expert workers. Consequently, a series of important tests and structural analyses other than being very expensive are highly subjective and could lack on repeatability and reliability. Moreover, not all the results of these analyses are logged or electronically stored. Following the current trend of automation under the Industry 4.0 framework, an automated robotic vehicle has been designed with the aim of addressing the above-mentioned issues. The main features of such robot are the small dimensions, a magnetic coupling that gives the possibility to move on ferromagnetic surfaces, a reliable mechanical assembly and a wide reconfigurability in terms of mechanical add-ons and plug-and-play sensors. The housed sensors could be optical or IR cameras, ultrasonic scanner, surface analyzer, eddy currents detectors and even more. The tests conducted so far in realistic environments show that the presented system can be used to perform standard and reproducible inspections of complex machines like power generators. Moreover, due to its reconfigurability this vehicle can easily extend its range of application and be used in the inspection of other machines and infrastructures such as windmill blade, cranes, bridges beams, vessels and similar
Sodium binding sites and permeation mechanism in the NaChBac channel:a molecular dynamics study
NaChBac was the first discovered bacterial sodium voltage-dependent channel, yet computational studies are still limited due to the lack of a crystal structure. In this work, a pore-only construct built using the NavMs template was investigated using unbiased molecular dynamics and metadynamics. The potential of mean force (PMF) from the unbiased run features four minima, three of which correspond to sites IN, CEN, and HFS discovered in NavAb. During the run, the selectivity filter (SF) is spontaneously occupied by two ions, and frequent access of a third one is often observed. In the innermost sites IN and CEN, Na+ is fully hydrated by six water molecules and occupies an on-axis position. In site HFS sodium interacts with a glutamate and a serine from the same subunit and is forced to adopt an off-axis placement. Metadynamics simulations biasing one and two ions show an energy barrier in the SF that prevents single-ion permeation. An analysis of the permeation mechanism was performed both computing minimum energy paths in the axial–axial PMF and through a combination of Markov state modeling and transition path theory. Both approaches reveal a knock-on mechanism involving at least two but possibly three ions. The currents predicted from the unbiased simulation using linear response theory are in excellent agreement with single-channel patch-clamp recording
Occurrence, antimicrobial susceptibility, and pathogenic factors of Pseudomonas aeruginosa in canine clinical samples
Background and Aim: Pseudomonas aeruginosa is a relevant opportunistic and difficult to treat pathogen due to its widespread environmental diffusion, intrinsic resistance to many classes of antimicrobials, high ability to acquire additional resistance mechanisms, and wide range of pathogenic factors. The present study aimed to investigate the prevalence of P. aeruginosa in canine clinical samples, the antimicrobial susceptibility against antipseudomonal antibiotics, and the presence of extracellular pathogenic factors of the isolates, as well as their ability to produce biofilm. Materials and Methods: Overall, 300 clinical specimens from dogs with pyoderma or abscesses (n=58), otitis (n=59), and suspected bladder infection (n=183) were analyzed by standard bacteriological methods. P. aeruginosa isolates were tested for their antimicrobial susceptibility by disk and gradient diffusion methods to determine the minimum inhibitory concentrations. The ability of the isolates to produce biofilm was investigated by a microtiter plate assay, while virulence genes coding for elastase (lasB), exotoxin A (toxA), alkaline protease (aprA), hemolytic phospholipase C (plcH), and exoenzyme S (ExoS) were detected by polymerase chain reaction method. Results: A total of 24 isolates of P. aeruginosa were found in clinical specimens (urine n=3, skin/soft tissue n=6, and ear canal n=15). No resistance was found to ceftazidime, gentamicin, aztreonam, and imipenem (IMI), while low levels of resistance were found to enrofloxacin (ENR) (4.2%) and piperacillin-tazobactam (8.3%). However, 41.7% and 29.2% of the isolates showed intermediate susceptibility to ENR and IMI, respectively. Disk and gradient diffusion methods showed high concordance. The majority of the isolates revealed a weak (33.3%) or intermediate (45.8%) ability to form biofilm, while the strong biofilm producers (20.8%) derived exclusively from the ear canal samples. All isolates (100%) were positive for lasB, aprA, and plcH genes, while exoS and toxA were amplified in 21 (87.5%) and 22 (91.7%) isolates, respectively. Conclusion: In the present study, P. aeruginosa isolates from canine clinical samples were characterized by low levels of antimicrobial resistance against antipseudomonal drugs. However, the high presence of isolates with intermediate susceptibility for some categories of antibiotics, including carbapenems which are not authorized for veterinary use, could represent an early warning signal. Moreover, the presence of isolates with strong ability to produce biofilm represents a challenge for the interpretation of the antimicrobial susceptibility profile. In addition, the high prevalence of the extracellular pathogenic factors was indicative of the potential virulence of the isolates
Ariel - Volume 10 Number 3
Executive Editors
Madalyn Schaefgen
David Reich
Business Manager
David Reich
News Editors
Medical College
Edward Zurad
CAHS
John Guardiani
World
Mark Zwanger
Features Editors
Meg Trexler
Jim O\u27Brien
Editorials Editor
Jeffrey Banyas
Photography and Sports Editor
Stuart Singer
Commons Editor
Brenda Peterso
Theory and Experiments on Multi-Ion Permeation and Selectivity in the NaChBac Ion Channel
The highly selective permeation of ions through biological ion channels is an unsolved problem of noise and fluctuations. In this paper, we motivate and introduce a non-equilibrium and self-consistent multi-species kinetic model, with the express aims of comparing with experimental recordings of current versus voltage and concentration and extracting important permeation parameters. For self-consistency, the behavior of the model at the two-state, i.e., selective limit in linear response, must agree with recent results derived from an equilibrium statistical theory. The kinetic model provides a good fit to data, including the key result of an anomalous mole fraction effect
Quality of t-cell response to SARS-CoV-2 mrrna vaccine in art-treated plwh
We investigated specific humoral and T-cell responses in people living with HIV (PLWH) before (T0), after two (T1) and after six months (T2) from the third dose of the BNT162b2 vaccine. Healthy donors (HD) were enrolled. The specific humoral response was present in most PLWH already after the second dose, but the third dose increased both the rate of response and its magnitude. Collectively, no significant differences were found in the percentage of responding T-cells between PLWH and HD. At T0, stratifying PLWH according to CD4 cell count, a lower percentage of responding T-cells in 200 cells/mu L one was observed. At T1, this parameter was comparable between the two subgroups, and the same result was found at T2. However, the pattern of co-expression of IFN gamma, IL2 and TNF alpha in PLWH was characterized by a higher expression of TNF alpha, independently of CD4 cell count, indicating a persistent immunological signature despite successful ART. mRNA vaccination elicited a specific response in most PLWH, although the cellular one seems qualitatively inferior compared to HD. Therefore, an understanding of the T-cell quality dynamic is needed to determine the best vaccination strategy and, in general, the capability of immune response in ART-treated PLWH
Cross-Species Mechanical Fingerprinting of Cardiac Myosin Binding Protein-C
AbstractCardiac myosin binding protein-C (cMyBP-C) is a member of the immunoglobulin (Ig) superfamily of proteins and consists of 8 Ig- and 3 fibronectin III (FNIII)-like domains along with a unique regulatory sequence referred to as the MyBP-C motif or M-domain. We previously used atomic force microscopy to investigate the mechanical properties of murine cMyBP-C expressed using a baculovirus/insect cell expression system. Here, we investigate whether the mechanical properties of cMyBP-C are conserved across species by using atomic force microscopy to manipulate recombinant human cMyBP-C and native cMyBP-C purified from bovine heart. Force versus extension data obtained in velocity-clamp experiments showed that the mechanical response of the human recombinant protein was remarkably similar to that of the bovine native cMyBP-C. Ig/Fn-like domain unfolding events occurred in a hierarchical fashion across a threefold range of forces starting at relatively low forces of ∼50 pN and ending with the unfolding of the highest stability domains at ∼180 pN. Force-extension traces were also frequently marked by the appearance of anomalous force drops suggestive of additional mechanical complexity such as structural coupling among domains. Both recombinant and native cMyBP-C exhibited a prominent segment ∼100 nm-long that could be stretched by forces <50 pN before the unfolding of Ig- and FN-like domains. Combined with our previous observations of mouse cMyBP-C, these results establish that although the response of cMyBP-C to mechanical load displays a complex pattern, it is highly conserved across species
Comparative Treatment Outcomes for Patients With Idiopathic Subglottic Stenosis.
To access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked DownloadImportance: Surgical treatment comparisons in rare diseases are difficult secondary to the geographic distribution of patients. Fortunately, emerging technologies offer promise to reduce these barriers for research.
Objective: To prospectively compare the outcomes of the 3 most common surgical approaches for idiopathic subglottic stenosis (iSGS), a rare airway disease.
Design, setting, and participants: In this international, prospective, 3-year multicenter cohort study, 810 patients with untreated, newly diagnosed, or previously treated iSGS were enrolled after undergoing a surgical procedure (endoscopic dilation [ED], endoscopic resection with adjuvant medical therapy [ERMT], or cricotracheal resection [CTR]). Patients were recruited from clinician practices in the North American Airway Collaborative and an online iSGS community on Facebook.
Main outcomes and measures: The primary end point was days from initial surgical procedure to recurrent surgical procedure. Secondary end points included quality of life using the Clinical COPD (chronic obstructive pulmonary disease) Questionnaire (CCQ), Voice Handicap Index-10 (VHI-10), Eating Assessment Test-10 (EAT-10), the 12-Item Short-Form Version 2 (SF-12v2), and postoperative complications.
Results: Of 810 patients in this cohort, 798 (98.5%) were female and 787 (97.2%) were white, with a median age of 50 years (interquartile range, 43-58 years). Index surgical procedures were ED (n = 603; 74.4%), ERMT (n = 121; 14.9%), and CTR (n = 86; 10.6%). Overall, 185 patients (22.8%) had a recurrent surgical procedure during the 3-year study, but recurrence differed by modality (CTR, 1 patient [1.2%]; ERMT, 15 [12.4%]; and ED, 169 [28.0%]). Weighted, propensity score-matched, Cox proportional hazards regression models showed ED was inferior to ERMT (hazard ratio [HR], 3.16; 95% CI, 1.8-5.5). Among successfully treated patients without recurrence, those treated with CTR had the best CCQ (0.75 points) and SF-12v2 (54 points) scores and worst VHI-10 score (13 points) 360 days after enrollment as well as the greatest perioperative risk.
Conclusions and relevance: In this cohort study of 810 patients with iSGS, endoscopic dilation, the most popular surgical approach for iSGS, was associated with a higher recurrence rate compared with other procedures. Cricotracheal resection offered the most durable results but showed the greatest perioperative risk and the worst long-term voice outcomes. Endoscopic resection with medical therapy was associated with better disease control compared with ED and had minimal association with vocal function. These results may be used to inform individual patient treatment decision-making.Patient-Centered Outcomes Research Institute - PCOR
Computational Characterization of tartrate-based TACE inhibitors
Small-molecule inhibitors of Tumor Necrosis factor alpha Converting Enzyme (TACE) are a
promising therapeutic tool for Rheumatoid Arthritis, Multiple Sclerosis and other autoimmune
diseases. Here we report on Hamiltonian Replica Exchange Molecular dynamics simulations of
three tartrate-based TACE inhibitors. The simulations show that irrespective of the inhibition
constant, the three drugs in bulk solvent adopt a common compact conformation whereby the
hydrophobic right-hand side and left-hand side substituents are packed against each other and the
hydroxyls necessary for Zinc chelation in the TACE active site are exposed toward the solvent.
Since the drugs in complex with TACE are expected to be in the extended conformation, our results
support the hypothesis of a structural rearrangement upon ligand binding. The proposed mechanism
may have important implications for the rational drug design