Regional Activation of Myosin II in Cancer Cells Drives Tumor Progression via a Secretory Cross-Talk with the Immune Microenvironment

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Diez recomendaciones para mejorar la enseñanza de la Geriatría en el pregrado

IntroductionPopulation ageing and scientific progress have made specific training in Geriatrics essential for any medical students. There are different international recommendations on the teaching of Geriatric Medicine at undergraduate level, but they are still far from being offered systematically. The aim of this work was to develop a National list of recommendations in order to improve training in Geriatric Medicine at the undergraduate level.Material and methodsA list of 10 recommendations was produced by reflecting on the Geriatric training situation in Spain in 2016/2017 and international recommendations. Consensus was reached among the members of the Spanish Society of Geriatrics and Gerontology (SEGG) working group on «Geriatric training at undergraduate level» through 2 meetings and online discussions.ResultsA list of 10 of recommendations on Geriatric training in Spanish Medical Schools is proposed, including areas such as, the status of the discipline in the curriculum, length, contents, practical training, lecturers, teaching methods, and innovation.ConclusionsThese recommendations are intended to improve Geriatrics training. They can be used by different Medical Schools either to adapt their programs or to start training in Geriatric Medicine.     

Effects of Buprenorphine Treatment on Influenza Pathogenesis in the Ferret (Mustela putorius furo)

Ferrets are the gold-standard model for influenza A virus (IAV) research due to their natural susceptibility to human and zoonotic IAV, comparable respiratory anatomy and physiology to humans, and development of clinical signs similar to those seen in infected people. Because the presence and progression of clinical signs can be useful in infectious disease research, uncertainty in how analgesics alter research outcomes or compromise characteristics of disease progression have outweighed the concern regarding animal discomfort from these symptoms. Nonetheless, the principles of animal research require consideration of refinements for this important model for IAV research. Opioids offer a possible refinement option that would not directly affect the inflammatory cascade involved in IAV infection. Mirroring pathogenicity studies that use ferrets, 12 ferrets were inoculated intranasally with the A(H3N2) IAV A/Panama/2007/1999 and divided into 3 treatment groups (n = 4 each), of which 2 groups received buprenorphine treatments on different schedules and the third received a saline control. The duration and location of viral replication, lymphohematopoietic changes, and clinical signs were comparable across all groups at all time points. High quantities of infectious virus in nasal wash specimens were detected in ferrets from all groups through day 5 after inoculation, and peak viral titers from the upper respiratory tract did not differ between ferrets receiving buprenorphine treatments on either schedule. Compared with the saline group, ferrets receiving buprenorphine exhibited transient weight loss and pyrexia, but all groups ultimately achieved similar peaks in both of these measurements. Collectively, these findings support the continued evaluation of buprenorphine as a refinement for IAV-challenged ferrets.

Despite decades of international research and the availability of public health countermeasures, including vaccines and antivirals, influenza viruses remain a persistent threat to human and animal health.^26,35 Influenza A viruses (IAV) exhibit a diverse range of virulence, exist in several host reservoirs, and can show rapid rates of antigenic change.²⁶ As a result, IAV are associated with both seasonal epidemics and occasional pandemics in humans,³⁵ and animal infections with IAV have become key for understanding multifactorial traits that include pathogenicity, transmissibility, and vaccine efficacy. Due to their relatively small size, adaptability to the research setting, and similarities to human lung anatomy and physiology, ferrets provide an excellent model for respiratory diseases in humans and are a valuable small-animal model for such studies.^8,30 Data generated from ferrets are included in numerous risk-assessment rubrics evaluating the pandemic potential of novel and emerging influenza viruses, including those established by the Centers for Disease Control and Prevention and the World Health Organization.^14,51The study of influenza virus in ferrets dates back to the early 1930s, when this species was first found to be susceptible to influenza virus.⁴⁴ Ferrets are naturally susceptible to both human and zoonotic IAV.⁴⁷ After infection, ferrets present with clinical signs like those of humans; these signs are often not recapitulated in other species, such as mice and guinea pigs.^28,39,46 The severity and spectrum of clinical signs associated with influenza virus–inoculated ferrets can vary, depending on the virus strain, route and dose of inoculation, and various host parameters.⁵ Whereas influenza viruses with low virulence in ferrets may cause only acute pyrexia and mild to moderate weight loss, isolates with high virulence can cause severe, systemic illness with gastrointestinal and neurologic symptoms.⁴The 3Rs, replace, reduce, refine, encourage investigation of how research involving animals can be conducted in more humane ways.^2,13,37,41 Analgesia for symptoms of influenza in ferrets represents an opportunity for refinement, but this intervention could confound research assessing disease progression. NSAID and corticosteroids are often prescribed to treat the clinical signs associated with influenza in humans.⁴³ These interventions could alter the inflammatory cascade and subsequent pathophysiology of the disease, thus reducing the validity of studies designed to characterize and compare influenza viruses.^6,43 NSAID reportedly inhibit nuclear factor κB, a regulator of inflammatory processes that is involved in viral RNA synthesis.^25,27 In addition, NSAID have been found to increase survival rates in influenza virus-infected mice.⁵³ Therefore, the use of NSAID may be problematic in studies investigating the pathogenesis of influenza viruses.Buprenorphine, an opioid, is an established analgesic in ferrets that can be administered either intravascularly, intramuscularly, or subcutaneously at 0.01 to 0.05 mg/kg with an analgesic duration of 6 to 12 h.^{11,16,24,38,52} Historically buprenorphine has been described as a partial µ receptor agonist and κ and γ receptor antagonist,^22,29,40,48 but the drug recently was described to behave as a full µ agonist.³⁶ The ceiling effect of analgesia and the immunosuppressive effects reported with other opioids have not been documented to occur with buprenorphine.^15,36,42 However, the use of buprenorphine does have the possibility of adverse effects, including sedation, weight loss, constipation, and respiratory depression.^{10,15,16,22,23,34,42} Nonetheless, buprenorphine is a commonly prescribed analgesic for numerous small mammalian species used in research settings.^20,22,40Given that influenza is an ongoing threat to human and animal health and because no replacement is available for data gained with the ferret model, pain mitigation options for research conducted in this species must be addressed. To date, concerns about altering the course of the disease have precluded the evaluation of refinements options in IAV-infected ferrets. The goal of the current study was to assess the effects of buprenorphine treatments on the pathogenesis of a seasonal IAV in ferrets; this assessment was achieved by comparing virus-inoculated ferrets that were either sham-treated or that received buprenorphine according to 2 different dosing schedules. We hypothesized that buprenorphine treatments would not affect experimental readouts, including morbidity, viral shedding, lymphopenia, and seroconversion in convalescent serum; these parameters are commonly measured during IAV research. Study results indicate that buprenorphine did not uniformly or significantly modulate disease progression, peak viral titers in the upper respiratory tract, or clinical responses used to characterize viral pathogenicity in ferrets.     

An atomic model for actin binding by the CH domains and spectrin-repeat modules of utrophin and dystrophin

Utrophin and dystrophin link cytoskeletal F-actin filaments to the plasmalemma. Genetic strategies to replace defective dystrophin with utrophin in individuals with muscular dystrophy requires full characterization of these proteins. Both contain homologous N-terminal actin-binding motifs composed of a pair of calponin-homology (CH) domains (CH1 and CH2) that are connected by spectrin-repeat modules to C-terminal membrane-binding sequences. Here, electron microscopy and 3D reconstruction of F-actin decorated with utrophin and dystrophin actin-binding constructs were performed using Utr261 (utrophin's CH domain pair), Utr416 (utrophin's CH domains and first spectrin-repeat) and Dys246 (dystrophin's CH domain pair). The lozenge-like utrophin CH domain densities localized to the upper surface of actin subdomain 1 and extended azimuthally over subdomain 2 toward subdomains 3 and 4. The cylinder-shaped spectrin-repeat was located at the end of the CH domain pair and was aligned longitudinally along the cleft between inner and outer actin domains, where tropomyosin is present when on thin filaments. The connection between the spectrin-repeat module and the CH domains defined the orientation of CH1 and CH2 on actin. Resolution of utrophin's CH domains and spectrin-repeats permitted docking of crystal structures into respective EM densities, leading to an atomic model where both CH and spectrin-domains bind actin. The CH domain-actin interaction for dystrophin was found to be more complex than for utrophin. Binding assays showed that Utr261 and Utr416 interacted with F-actin as monomers, whereas Dys246 appeared to associate as a dimer, consistent with a bilobed Dys246 structure observed on F-actin in electron microscope reconstructions. One of the lobes was similar in shape, position and orientation to the monomeric CH domains of Utr261, while the other lobe apparently represented a second set of CH domains in the dimeric Dys246. The extensive contact made by dystrophin on actin may be used in vivo to help muscles dissipate mechanical stress from the contractile apparatus to the extracellular matrix.     

Alveolar macrophage apoptosis contributes to pneumococcal clearance in a resolving model of pulmonary infection

The role of alveolar macrophages (AM) in host defense against pulmonary infection has been difficult to establish using in vivo models. This may reflect a reliance on models of fulminant infection. To establish a unique model of resolving infection, with which to address the function of AM, C57BL/6 mice received low-dose intratracheal administration of pneumococci. Administration of low doses of pneumococci produced a resolving model of pulmonary infection characterized by clearance of bacteria without features of pneumonia. AM depletion in this model significantly increased bacterial outgrowth in the lung. Interestingly, a significant increase in the number of apoptotic AM was noted with the low-dose infection as compared with mock infection. Caspase inhibition in this model decreased AM apoptosis and increased the number of bacteremic mice, indicating a novel role for caspase activation in pulmonary innate defense against pneumococci. These results suggest that AM play a key role in clearance of bacteria from the lung during subclinical infection and that induction of AM apoptosis contributes to the microbiologic host defense against pneumococci.