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1.
Prev Vet Med ; 226: 106185, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38507889

RESUMO

The global rise in companion animal populations, particularly dogs and cats, is driven by emotional and social benefits for owners, and their population management is becoming critically important to avoid a plethora of adverse effects on themselves, humans, and wildlife. We estimated the size and density of the owned canine and feline population in Chile and evaluated the status of microchipping, registration, sterilization rates, and the proportion of owned animals that roam unsupervised. A cross-sectional household survey in 36 districts was conducted and standard inferential statistics was employed to analyze differences between cats and dogs, sexes within each species, and between rural and urban areas. Additionally, two negative binomial models with mixed effects were developed to predict the number of dogs and cats per households. Two methods were used to compare population size estimates at the country level, multiplying: (1) the estimated mean number of companion animals per household by the estimated number of households at the country level, and (2) the estimated human:dog and human:cat ratios by the total human population. The study involved 6333 respondents, of which 76% (74% urban; 83% rural) owned companion animals (dogs and/or cats). Individuals in rural multi-person households increase the probability of owning dogs and/or cats. Additionally, women exhibit a greater inclination towards cat and dog ownership compared to men, while those over 30 years old demonstrate lower rates of companion animal ownership in contrast to the 18-30 age group for both species. The overall human:dog and human:cat ratios estimated were 2.7:1, and 6.2:1, respectively. The estimated total number of owned dogs and cats in Chile ranged from 9.6 to 10.7 million, depending on the methodological approach, while national median density of companion animals was 12 dogs per km2 (ranging from 0.02 to 7232) and 5 cats per km2 (ranging from 0.01 to 3242). This nationwide study showed one of the highest percentages of households with companion animals in Latin America and relatively low registration and sterilization rates, highlighting the need to strength long-term public policies to control populations of companion animals and promote responsibility in pet ownership.


Assuntos
Doenças do Gato , Doenças do Cão , Masculino , Animais , Humanos , Gatos , Cães , Feminino , Estudos Transversais , Chile/epidemiologia , Doenças do Cão/epidemiologia , Animais Selvagens , Características da Família , Propriedade
2.
Stem Cell Res Ther ; 15(1): 70, 2024 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-38454524

RESUMO

BACKGROUND: Initially discovered for its ability to regenerate ear holes, the Murphy Roth Large (MRL) mouse has been the subject of multiple research studies aimed at evaluating its ability to regenerate other body tissues and at deciphering the mechanisms underlying it. These enhanced abilities to regenerate, retained during adulthood, protect the MRL mouse from degenerative diseases such as osteoarthritis (OA). Here, we hypothesized that mesenchymal stromal/stem cells (MSC) derived from the regenerative MRL mouse could be involved in their regenerative potential through the release of pro-regenerative mediators. METHOD: To address this hypothesis, we compared the secretome of MRL and BL6 MSC and identified several candidate molecules expressed at significantly higher levels by MRL MSC than by BL6 MSC. We selected one candidate, Plod2, and performed functional in vitro assays to evaluate its role on MRL MSC properties including metabolic profile, migration, and chondroprotective effects. To assess its contribution to MRL protection against OA, we used an experimental model for osteoarthritis induced by collagenase (CiOA). RESULTS: Among the candidate molecules highly expressed by MRL MSC, we focused our attention on procollagen-lysine,2-oxoglutarate 5-dioxygenase 2 (PLOD2). Plod2 silencing induced a decrease in the glycolytic function of MRL MSC, resulting in the alteration of their migratory and chondroprotective abilities in vitro. In vivo, we showed that Plod2 silencing in MRL MSC significantly impaired their capacity to protect mouse from developing OA. CONCLUSION: Our results demonstrate that the chondroprotective and therapeutic properties of MRL MSC in the CiOA experimental model are in part mediated by PLOD2.


Assuntos
Células-Tronco Mesenquimais , Osteoartrite , Animais , Camundongos , Células-Tronco Mesenquimais/metabolismo , Osteoartrite/genética , Pró-Colágeno-Lisina 2-Oxoglutarato 5-Dioxigenase/genética , Pró-Colágeno-Lisina 2-Oxoglutarato 5-Dioxigenase/metabolismo
3.
Skin Health Dis ; 4(1): e310, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38312257

RESUMO

Psychodermatology is a subdiscipline of dermatology at the intersection of dermatology, psychiatry, and psychology. In dermatology clinical practice, patients may present with skin disease that affects their mental health, or skin disorders induced or worsened by psychological/psychiatric problems so there is a need for specialised education of dermatologists, as well as multidisciplinary teams, to achieve better management of these patients. Understanding the interaction between the central nervous system and the skin underlying psychocutaneous disorders could help identify alternative therapies that may improve patient well-being. The concept of pleasurable touch has received increasing attention following the discovery of C-tactile (CT) fibres. While afferent C-fibre stimulation is usually associated with pain, temperature, or itch, CT-fibres are stimulated optimally by a stimulus not in the nociceptor range but by a gentle, low-force stroking. As this affective touch may counteract unpleasurable sensations, such as pain and itch, and elicit positive feelings, the potential benefits of gentle touch and massage are interesting for dermatological, especially psychocutaneous, disorders. Here we provide an overview of the skin-brain connection to help understand the benefits of touch and massage, as illustrated with studies on atopic dermatitis and burns, as an adjunct to dermatological treatment for improving patient well-being and optimising treatment outcomes.

4.
Prev Vet Med ; 225: 106141, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38359471

RESUMO

BACKGROUND: Irresponsible dog ownership in urban areas is a public health concern with significant implications for human, animal, and environmental welfare. Factors such as abandonment, variations in adoption, insufficient supervision, emerging identification initiatives, and collective feeding impact the growth of stray dog populations and the transmission of diseases. Developing a modeling tool to understand the dynamics of canine population growth and the effect of human behavior on this phenomenon is essential. METHODS: An ordinary differential equation model was developed to depict the growth dynamics and movements of urban dog populations, distinguishing between those with owners (restricted and semi-restricted) and those without (stray and community dogs). Two equilibrium states of the system were analyzed: with and without the presence of individually owned dogs. An increase rate for the population of individually owned dogs was calculated, and a local sensitivity analysis was conducted to assess the impact of parameters on the reduction of this population. Additionally, two global sensitivity analysis methods were used to evaluate the simultaneous influence of the parameters. RESULTS: Findings indicate that system equilibrium depends on various dog categories. Although total eradication of stray and community dogs is unlikely, equilibrium levels are directly related to subpopulation growth rates, responsible ownership practices, and adoption and abandonment rates. The growth rates of the population of dogs without individual owners have a direct and proportional influence on their regulation, while adoption rates have an inverse and proportional effect. The study, through global sensitivity analysis, identifies key parameters for each dog subpopulation. For restricted dogs, environmental carrying capacity is the most variable factor; for semi-restricted dogs, awareness of responsible ownership is crucial. The abandonment of restricted dogs significantly impacts stray dog dynamics, while the transition from stray to community status is an important variable factor for community dogs. CONCLUSION: Addressing the situation of unowned dogs requires a collective effort to reduce risks associated with the spread of zoonotic diseases, environmental pollution, and biodiversity loss, thus contributing to public health and environmental conservation.


Assuntos
Doenças do Cão , Modelos Teóricos , Animais , Cães , Humanos , Chile , Dinâmica Populacional , População Urbana , Propriedade , Doenças do Cão/epidemiologia
5.
Diagnostics (Basel) ; 14(2)2024 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-38275468

RESUMO

COVID-19 made explicit the need for rethinking the way in which we conduct testing for epidemic emergencies. During the COVID-19 pandemic, the dependence on centralized lab facilities and resource-intensive methodologies (e.g., RT-qPCR methods) greatly limited the deployment of widespread testing efforts in many developed and underdeveloped countries. Here, we illustrate the development of a simple and portable diagnostic kit that enables self-diagnosis of COVID-19 at home from saliva samples. We describe the development of a do-it-yourself (DIY) incubator for Eppendorf tubes that can be used to conduct SARS-CoV-2 detection with competitive sensitivity and selectivity from saliva at home. In a proof-of-concept experiment, we assembled Eppendorf-tube incubators at our home shop, prepared a single-tube mix of reagents and LAMP primers in our lab, and deployed these COVID-19 detection kits using urban delivery systems (i.e., Rappifavor or Uber) to more than 15 different locations in Monterrey, México. This straightforward strategy enabled rapid and cost-effective at-home molecular diagnostics of SARS-CoV-2 from real saliva samples with a high sensitivity (100%) and high selectivity (87%).

6.
Artigo em Inglês | MEDLINE | ID: mdl-37456140

RESUMO

Flexible reward learning relies on frontal cortex, with substantial evidence indicating that anterior cingulate cortex (ACC) and orbitofrontal cortex (OFC) subregions play important roles. Recent studies in both rat and macaque suggest theta oscillations (5-10 Hz) may be a spectral signature that coordinates this learning. However, network-level interactions between ACC and OFC in flexible learning remain unclear. We investigated the learning of stimulus-reward associations using a combination of simultaneous in vivo electrophysiology in dorsal ACC and ventral OFC, partnered with bilateral inhibitory DREADDs in ACC. In freely behaving male and female rats and using a within-subject design, we examined accuracy and speed of response across distinct and precisely defined trial epochs during initial visual discrimination learning and subsequent reversal of stimulus-reward contingencies. Following ACC inhibition, there was a propensity for random responding in early reversal learning, with correct vs. incorrect trials distinguished only from OFC, not ACC, theta power differences in the reversal phase. ACC inhibition also hastened incorrect choices during reversal. This same pattern of change in accuracy and speed was not observed in viral control animals. Thus, characteristics of impaired reversal learning following ACC inhibition are poor deliberation and weak theta signaling of accuracy in this region. The present results also point to OFC theta oscillations as a prominent feature of reversal learning, unperturbed by ACC inhibition.

7.
ACS Biomater Sci Eng ; 9(6): 3462-3475, 2023 06 12.
Artigo em Inglês | MEDLINE | ID: mdl-37126642

RESUMO

We present a simple and cost-effective strategy for developing gelatin methacryloyl (GelMA) hydrogels supplemented with minimally processed tissue (MPT) to fabricate densely packed skeletal-muscle-like tissues. MPT powder was prepared from skeletal muscle by freeze-drying, grinding, and sieving. Cell-culture experiments showed that the incorporation of 0.5-2.0% (w/v) MPT into GelMA hydrogels enhances the proliferation of murine myoblasts (C2C12 cells) compared to proliferation in pristine GelMA hydrogels and GelMA supplemented with decellularized skeletal-muscle tissues (DCTs). MPT-supplemented constructs also preserved their three-dimensional (3D) integrity for 28 days. By contrast, analogous pristine GelMA constructs only maintained their structure for 14 days or less. C2C12 cells embedded in MPT-supplemented constructs exhibited a higher degree of cell alignment and reached a significantly higher density than cells loaded in pristine GelMA constructs. Our results suggest that the addition of MPT incorporates a rich source of biochemical and topological cues, such as growth factors, glycosaminoglycans (GAGs), and structurally preserved proteins (e.g., collagen). In addition, GelMA supplemented with MPT showed suitable rheological properties for use as bioinks for extrusion bioprinting. We envision that this simple and cost-effective strategy of hydrogel supplementation will evolve into an exciting spectrum of applications for tissue engineers, primarily in the biofabrication of relevant microtissues for in vitro models and cultured meat and ultimately for the biofabrication of transplant materials using autologous MPT.


Assuntos
Impressão Tridimensional , Alicerces Teciduais , Animais , Camundongos , Alicerces Teciduais/química , Hidrogéis/farmacologia , Hidrogéis/química , Músculo Esquelético
8.
Rev Med Inst Mex Seguro Soc ; 61(3): 283-288, 2023 May 02.
Artigo em Espanhol | MEDLINE | ID: mdl-37216426

RESUMO

Background: Ankle fractures are among the most frequent fractures in the lower limb, predominantly affecting young people and representing approximately 9% of all fractures. Objective: To identify the factors associated with functionality in patients with closed ankle fracture. Material and methods: Observational and retrospective study. Records of people with a diagnosis of ankle fractures admitted to rehabilitation between January to December 2020 in a Physical Medicine and Rehabilitation Unit of a third level hospital were included. Age, sex, body mass index (BMI), days of disability, mechanism of injury, type of treatment, length of stay in rehabilitation, type of fracture and functionality were captured. Chi-squared and Student's t test were used to determine the association. Subsequently a multivariate analysis with binary logistic regression was performed. Results: The average age of the subjects was 44.8 years, the female sex was presented in 54.7%, the average BMI was 28.8%, 66% carried out a paid work activity, 65% received surgical treatment, the average time of disability was 140 days, the factors associated with functionality independently were age, pain, dorsiflexion and plantar flexion upon admission to rehabilitation. Conclusions: Ankle fractures occur in a young population and the factors associated with functionality were age, dorsiflexion, plantar flexion, and pain upon admission to rehabilitation.


Introducción: las fracturas de tobillo son las fracturas más frecuentes en el miembro inferior. Afectan predominantemente a personas jóvenes y representan aproximadamente el 9% de todas las fracturas. Objetivo: identificar los factores asociados a funcionalidad en pacientes con fractura cerrada de tobillo. Material y métodos: estudio observacional y retrospectivo. Se incluyeron expedientes de personas con diagnóstico de fractura cerrada de tobillo ingresados a rehabilitación entre enero y diciembre del 2020 en la Unidad de Medicina Física y Rehabilitación de tercer nivel. Se registró edad, sexo, índice de masa corporal (IMC), días de incapacidad, mecanismo de lesión, tipo de tratamiento, tiempo de estancia en rehabilitación, tipo de fractura y funcionalidad. Para determinar la asociación de las variables con la funcionalidad se utilizó la prueba de chi cuadrada y t de Student, y posteriormente se hizo un análisis multivariado con regresión logística bivariada. Resultados: la edad promedio de los sujetos fue de 44.8 años, el sexo femenino se presentó en el 54.7%, el IMC promedio fue de 28.8%, 66% realizaba una actividad laboral remunerada, el 65% recibió tratamiento quirúrgico, el tiempo de incapacidad promedio fue de 140 días, los factores asociados a funcionalidad de manera independiente fueron la edad, el dolor, la dorsiflexión y la flexión plantar al ingreso de rehabilitación. Conclusiones: las fracturas de tobillo se presentan en población joven y los factores asociados a funcionalidad fueron la edad, dorsiflexión, flexión plantar y dolor al ingreso de rehabilitación.


Assuntos
Fraturas do Tornozelo , Humanos , Feminino , Adolescente , Adulto , Fraturas do Tornozelo/diagnóstico , Fraturas do Tornozelo/cirurgia , Estudos Retrospectivos , Fixação Interna de Fraturas , Dor , Resultado do Tratamento
9.
bioRxiv ; 2023 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-37066321

RESUMO

Reversal learning measures the ability to form flexible associations between choice outcomes with stimuli and actions that precede them. This type of learning is thought to rely on several cortical and subcortical areas, including highly interconnected orbitofrontal cortex (OFC) and basolateral amygdala (BLA), and is often impaired in various neuropsychiatric and substance use disorders. However, unique contributions of these regions to stimulus- and action-based reversal learning have not been systematically compared using a chemogenetic approach and particularly before and after the first reversal that introduces new uncertainty. Here, we examined the roles of ventrolateral OFC (vlOFC) and BLA during reversal learning. Male and female rats were prepared with inhibitory DREADDs targeting projection neurons in these regions and tested on a series of deterministic and probabilistic reversals during which they learned about stimulus identity or side (left or right) associated with different reward probabilities. Using a counterbalanced within-subject design, we inhibited these regions prior to reversal sessions. We assessed initial and pre-post reversal changes in performance to measure learning and adjustments to reversals, respectively. We found that inhibition of vlOFC, but not BLA, eliminated adjustments to stimulus-based reversals. Inhibition of BLA, but not vlOFC, selectively impaired action-based probabilistic reversal learning, leaving deterministic reversal learning intact. vlOFC exhibited a sex-dependent role in early adjustment to action-based reversals, but not in overall learning. These results reveal dissociable roles for BLA and vlOFC in flexible learning and highlight a more crucial role for BLA in learning meaningful changes in the reward environment.

10.
Prev Vet Med ; 213: 105882, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36867925

RESUMO

Global companion animal population has been increasing as well as the number of dogs and cats being considered as a family member. However, it is unclear whether this close relationship could be associated with higher preventive healthcare in companion animals. Using data from 7,048 questionnaires of dogs and 3,271 of cats from the First National Study on Responsible Companion Animal Ownership, we estimated the proportion of preventive healthcare in companion animals of Chile. We also conducted a general linear mixed-effect regression model to identify socioeconomic factors and indicators of the emotional owners-companion animal bond that could influence owners' practices related to vaccination, parasite control, and veterinary visits. Based on the owner's answers, Chile has a satisfactory overall rates of parasite control (71%) and annual veterinary visits (65%) but a low vaccination coverage of both dogs (39%) and cats (25%). 'Purebred', 'live in urban areas', 'acquired by monetary compensation', and 'dog species' were associated with a higher probability of preventive healthcare in companion animals. Conversely, this probability was lower among senior animals compared to adults, males, and those owned by the Silent Generation or Baby Boomers (i.e., owners born before 1964). 'Sleeping inside', 'acquired for an emotional reason' (e.g., companionship), and 'considered a family member' were positively associated with at least one of assessed preventive measures. Our findings suggest that emotional owner-companion animal bonds could positively impact the frequency and quality of preventive healthcare in dogs and cats. However, owners who totally disagreed that a companion animal is a "family member" were also associated with a higher likelihood of vaccination uptake and veterinary visits for their animals. This highlights that owner's compliance with veterinary preventive healthcare is multifactorial. Chile has a high prevalence of infectious diseases circulating among dogs and cats and increasingly close contacts between owners and companion animals due to emotional bonds. Thus, our study calls for One Health approaches to reduce the risks of cross-species disease transmission. Specifically, increasing vaccination coverage of companion animals in Chile is the most urgent preventive measure needed, especially among cats, males, and older animals. Expand preventive healthcare among dogs and cats will promote public and animal health, including local wildlife that is susceptible to infectious diseases circulating in companion animals.


Assuntos
Doenças do Gato , Doenças do Cão , Masculino , Animais , Gatos , Cães , Animais de Estimação , Doenças do Gato/epidemiologia , Doenças do Gato/prevenção & controle , Doenças do Gato/parasitologia , Chile/epidemiologia , Apego ao Objeto , Doenças do Cão/epidemiologia , Doenças do Cão/prevenção & controle , Doenças do Cão/parasitologia , Atenção à Saúde , Fatores Socioeconômicos , Inquéritos e Questionários , Propriedade
12.
Cogn Affect Behav Neurosci ; 23(3): 600-619, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-36823249

RESUMO

Despite being unpredictable and uncertain, reward environments often exhibit certain regularities, and animals navigating these environments try to detect and utilize such regularities to adapt their behavior. However, successful learning requires that animals also adjust to uncertainty associated with those regularities. Here, we analyzed choice data from two comparable dynamic foraging tasks in mice and monkeys to investigate mechanisms underlying adjustments to different types of uncertainty. In these tasks, animals selected between two choice options that delivered reward probabilistically, while baseline reward probabilities changed after a variable number (block) of trials without any cues to the animals. To measure adjustments in behavior, we applied multiple metrics based on information theory that quantify consistency in behavior, and fit choice data using reinforcement learning models. We found that in both species, learning and choice were affected by uncertainty about reward outcomes (in terms of determining the better option) and by expectation about when the environment may change. However, these effects were mediated through different mechanisms. First, more uncertainty about the better option resulted in slower learning and forgetting in mice, whereas it had no significant effect in monkeys. Second, expectation of block switches accompanied slower learning, faster forgetting, and increased stochasticity in choice in mice, whereas it only reduced learning rates in monkeys. Overall, while demonstrating the usefulness of metrics based on information theory in examining adaptive behavior, our study provides evidence for multiple types of adjustments in learning and choice behavior according to uncertainty in the reward environment.


Assuntos
Comportamento de Escolha , Recompensa , Camundongos , Animais , Incerteza , Haplorrinos , Aprendizagem , Tomada de Decisões
13.
Front Cell Dev Biol ; 9: 718938, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34604219

RESUMO

Osteoarthritis (OA), the most common degenerative and inflammatory joint disorder, is multifaceted. Indeed, OA characteristics include cartilage degradation, osteophytes formation, subchondral bone changes, and synovium inflammation. The difficulty in discovering new efficient treatments for OA patients up to now comes from the adoption of monotherapy approaches targeting either joint tissue repair/catabolism or inflammation to address the diverse components of OA. When satisfactory, these approaches only provide short-term beneficial effects, since they only result in the repair and not the full structural and functional reconstitution of the damaged tissues. In the present review, we will briefly discuss the current therapeutic approaches used to repair the damaged OA cartilage. We will highlight the results obtained with cell-based products in clinical trials and demonstrate how the current strategies result in articular cartilage repair showing restricted early-stage clinical improvements. In order to identify novel therapeutic targets and provide to OA patients long-term clinical benefits, herein, we will review the basis of the regenerative process. We will focus on macrophages and their ambivalent roles in OA development and tissue regeneration, and review the therapeutic strategies to target the macrophage response and favor regeneration in OA.

14.
Transl Psychiatry ; 11(1): 496, 2021 09 29.
Artigo em Inglês | MEDLINE | ID: mdl-34588417

RESUMO

Animal and human laboratory paradigms offer invaluable approaches to study the complex etiologies and mechanisms of alcohol use disorder (AUD). We contend that human laboratory models provide a "bridge" between preclinical and clinical studies of AUD by allowing for well-controlled experimental manipulations in humans with AUD. As such, examining the consilience between experimental models in animals and humans in the laboratory provides unique opportunities to refine the translational utility of such models. The overall goal of the present review is to provide a systematic description and contrast of commonly used animal paradigms for the study of AUD, as well as their human laboratory analogs if applicable. While there is a wide breadth of animal species in AUD research, the paradigms discussed in this review rely predominately on rodent research. The overarching goal of this effort is to provide critical analysis of these animal models and to link them to human laboratory models of AUD. By systematically contrasting preclinical and controlled human laboratory models, we seek to identify opportunities to enhance their translational value through forward and reverse translation. We provide future directions to reconcile differences between animal and human work and to improve translational research for AUD.


Assuntos
Alcoolismo , Animais , Humanos , Modelos Animais , Motivação , Pesquisa Translacional Biomédica
15.
Behav Neurosci ; 135(4): 550-570, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34460275

RESUMO

Reversal learning paradigms are widely used assays of behavioral flexibility with their probabilistic versions being more amenable to studying integration of reward outcomes over time. Prior research suggests differences between initial and reversal learning, including higher learning rates, a greater need for inhibitory control, and more perseveration after reversals. However, it is not well-understood what aspects of stimulus-based reversal learning are unique to reversals, and whether and how observed differences depend on reward probability. Here, we used a visual probabilistic discrimination and reversal learning paradigm where male and female rats selected between a pair of stimuli associated with different reward probabilities. We compared accuracy, rewards collected, omissions, latencies, win-stay/lose-shift strategies, and indices of perseveration across two different reward probability schedules. We found that discrimination and reversal learning are behaviorally more unique than similar: Fit of choice behavior using reinforcement learning models revealed a lower sensitivity to the difference in subjective reward values (greater exploration) and higher learning rates for the reversal phase. We also found latencies to choose the better option were greater in females than males, but only for the reversal phase. Further, animals employed more win-stay strategies during early discrimination and increased perseveration during early reversal learning. Interestingly, a consistent reward probability group difference emerged with a richer environment associated with longer reward collection latencies than a leaner environment. Future studies should systematically compare the neural correlates of fine-grained behavioral measures to reveal possible dissociations in how the circuitry is recruited in each phase. (PsycInfo Database Record (c) 2021 APA, all rights reserved).


Assuntos
Reversão de Aprendizagem , Recompensa , Animais , Comportamento de Escolha , Aprendizagem por Discriminação , Discriminação Psicológica , Feminino , Masculino , Ratos , Reforço Psicológico
16.
Rev. invest. clín ; 72(6): 337-343, Nov.-Dec. 2020. tab
Artigo em Inglês | LILACS | ID: biblio-1289728

RESUMO

Abstract Background: The presence of clinically relevant mutations in KRAS and NRAS genes determines the response of anti-epidermal growth factor receptor antibody therapy for metastatic colorectal cancer (mCRC). The only quantitative polymerase chain reaction (qPCR)-based diagnostic tests approved by the Food and Drug Administration (FDA) screen merely for mutations in codons 12 and 13 of KRAS. Objective: The objective of the study was to study the frequency of clinically relevant mutations in KRAS and NRAS genes that are not included in FDA-approved qPCR tests. Methods: Formalin-fixed paraffin-embedded tumor specimens from 1113 mCRC Mexican patients from different health institutions across the country were analyzed by Sanger sequencing for KRAS mutations in exons 2, 3, and 4. Furthermore, 83 were analyzed in exons 2, 3, and 4 of NRAS. Results: From the specimens tested for KRAS, 33.69% harbored a mutation. From these, 71.77% were in codon 12 and 27.69% in codon 13 (both located in exon 2). Codons 59 (exon 3) and 146 (exon 4) accounted for the remaining 0.54%. From the 83 specimens, in which NRAS was analyzed, three mutations were found in codon 12 (3.61%). Approximately 6% of RAS mutated specimens would have been falsely reported as RAS wild type if an FDA-approved qPCR diagnostic test had been used. Conclusions: While these kits based on qPCR can be very practical and highly sensitive, their mutation coverage ignores mutations from poorly genetically characterized populations.


Assuntos
Humanos , Reação em Cadeia da Polimerase , Éxons/genética , Proteínas Proto-Oncogênicas p21(ras)/genética , GTP Fosfo-Hidrolases/genética , Proteínas de Membrana/genética , Mutação , Kit de Reagentes para Diagnóstico , Estados Unidos , United States Food and Drug Administration , Comércio
17.
Front Immunol ; 11: 591240, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33193431

RESUMO

Aggregatibacter actinomycetemcomitans is a Gram-negative oral bacterium with high immunostimulatory and pathogenic potential involved in the onset and progression of periodontitis, a chronic disease characterized by aberrant immune responses followed by tooth-supporting bone resorption, which eventually leads to tooth loss. While several studies have provided evidence related to the virulence factors of A. actinomycetemcomitans involved in the host cell death and immune evasion, such as its most studied primate-specific virulence factor, leukotoxin, the role of specific lipopolysaccharide (LPS) domains remain poorly understood. Here, we analyzed the role of the immunodominant domain of the LPS of A. actinomycetemcomitans termed O-polysaccharide (O-PS), which differentiates the distinct bacterial serotypes based on its antigenicity. To determine the role of the O-PS in the immunogenicity and virulence of A. actinomycetemcomitans during periodontitis, we analyzed the in vivo and in vitro effect of an O-PS-defective transposon mutant serotype b strain, characterized by the deletion of the rmlC gene encoding the α-L-rhamnose sugar biosynthetic enzyme. Induction of experimental periodontitis using the O-PS-defective rmlC mutant strain resulted in lower tooth-supporting bone resorption, infiltration of Th1, Th17, and Th22 lymphocytes, and expression of Ahr, Il1b, Il17, Il23, Tlr4, and RANKL (Tnfsf11) in the periodontal lesions as compared with the wild-type A. actinomycetemcomitans strain. In addition, the O-PS-defective rmlC mutant strain led to impaired activation of antigen-presenting cells, with less expression of the co-stimulatory molecules CD40 and CD80 in B lymphocytes and dendritic cells, and downregulated expression of Tnfa and Il1b in splenocytes. In conclusion, these data demonstrate that the O-PS from the serotype b of A. actinomycetemcomitans plays a key role in the capacity of the bacterium to prime oral innate and adaptive immune responses, by triggering the Th1 and Th17-driven tooth-supporting bone resorption during periodontitis.


Assuntos
Aggregatibacter actinomycetemcomitans/imunologia , Aggregatibacter actinomycetemcomitans/patogenicidade , Periodontite/imunologia , Periodontite/microbiologia , Polissacarídeos Bacterianos/imunologia , Virulência/imunologia , Aggregatibacter actinomycetemcomitans/genética , Perda do Osso Alveolar/diagnóstico por imagem , Perda do Osso Alveolar/etiologia , Perda do Osso Alveolar/patologia , Animais , Biologia Computacional/métodos , Modelos Animais de Doenças , Feminino , Interações Hospedeiro-Patógeno/imunologia , Lipopolissacarídeos/imunologia , Camundongos , Mutação , Periodontite/complicações , Periodontite/diagnóstico , Sorogrupo , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo , Linfócitos T/imunologia , Linfócitos T/metabolismo , Fatores de Virulência , Microtomografia por Raio-X
18.
Rev Invest Clin ; 72(6): 337-343, 2020 12 22.
Artigo em Inglês | MEDLINE | ID: mdl-33053566

RESUMO

BACKGROUND: The presence of clinically relevant mutations in KRAS and NRAS genes determines the response of anti-epidermal growth factor receptor antibody therapy for metastatic colorectal cancer (mCRC). The only quantitative polymerase chain reaction (qPCR)-based diagnostic tests approved by the Food and Drug Administration (FDA) screen merely for mutations in codons 12 and 13 of KRAS. OBJECTIVE: The objective of the study was to study the frequency of clinically relevant mutations in KRAS and NRAS genes that are not included in FDA-approved qPCR tests. METHODS: Formalin-fixed paraffin-embedded tumor specimens from 1113 mCRC Mexican patients from different health institutions across the country were analyzed by Sanger sequencing for KRAS mutations in exons 2, 3, and 4. Furthermore, 83 were analyzed in exons 2, 3, and 4 of NRAS. RESULTS: From the specimens tested for KRAS, 33.69% harbored a mutation. From these, 71.77% were in codon 12 and 27.69% in codon 13 (both located in exon 2). Codons 59 (exon 3) and 146 (exon 4) accounted for the remaining 0.54%. From the 83 specimens, in which NRAS was analyzed, three mutations were found in codon 12 (3.61%). Approximately 6% of RAS mutated specimens would have been falsely reported as RAS wild type if an FDA-approved qPCR diagnostic test had been used. CONCLUSIONS: While these kits based on qPCR can be very practical and highly sensitive, their mutation coverage ignores mutations from poorly genetically characterized populations.


Assuntos
Éxons/genética , GTP Fosfo-Hidrolases/genética , Proteínas de Membrana/genética , Mutação , Reação em Cadeia da Polimerase , Proteínas Proto-Oncogênicas p21(ras)/genética , Comércio , Humanos , Kit de Reagentes para Diagnóstico , Estados Unidos , United States Food and Drug Administration
19.
Cells ; 9(7)2020 07 10.
Artigo em Inglês | MEDLINE | ID: mdl-32664207

RESUMO

Mesenchymal stem cells (MSCs) exhibit potent immunoregulatory abilities by interacting with cells of the adaptive and innate immune system. In vitro, MSCs inhibit the differentiation of T cells into T helper 17 (Th17) cells and repress their proliferation. In vivo, the administration of MSCs to treat various experimental inflammatory and autoimmune diseases, such as rheumatoid arthritis, type 1 diabetes, multiple sclerosis, systemic lupus erythematosus, and bowel disease showed promising therapeutic results. These therapeutic properties mediated by MSCs are associated with an attenuated immune response characterized by a reduced frequency of Th17 cells and the generation of regulatory T cells. In this manuscript, we review how MSC and Th17 cells interact, communicate, and exchange information through different ways such as cell-to-cell contact, secretion of soluble factors, and organelle transfer. Moreover, we discuss the consequences of this dynamic dialogue between MSC and Th17 well described by their phenotypic and functional plasticity.


Assuntos
Células-Tronco Mesenquimais/metabolismo , Células Th17/imunologia , Células Th17/metabolismo , Animais , Diferenciação Celular/fisiologia , Encefalomielite Autoimune Experimental/imunologia , Encefalomielite Autoimune Experimental/metabolismo , Encefalomielite Autoimune Experimental/terapia , Humanos , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais/imunologia
20.
PLoS One ; 15(6): e0234729, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32555668

RESUMO

BACKGROUND: Forced alcohol (ethanol, EtOH) exposure has been shown to cause significant impairments on reversal learning, a widely-used assay of cognitive flexibility, specifically on fully-predictive, deterministic versions of this task. However, previous studies have not adequately considered voluntary EtOH consumption and sex effects on probabilistic reversal learning. The present study aimed to fill this gap in the literature. METHODS: Male and female Long-Evans rats underwent either 10 weeks of voluntary intermittent 20% EtOH access or water only (H2O) access. Rats were then pretrained to initiate trials and learn stimulus-reward associations via touchscreen response, and subsequently required to select between two visual stimuli, rewarded with probability 0.70 or 0.30. In the final phase, reinforcement contingencies were reversed. RESULTS: We found significant sex differences on several EtOH-drinking variables, with females reaching a higher maximum EtOH consumption, exhibiting more high-drinking days, and escalating their EtOH at a quicker rate compared to males. During early abstinence, EtOH drinkers (and particularly EtOH-drinking females) made more initiation omissions and were slower to initiate trials than H2O drinking controls, especially during pretraining. A similar pattern in trial initiations was also observed in discrimination, but not in reversal learning. EtOH drinking rats were unaffected in their reward collection and stimulus response times, indicating intact motivation and motor responding. Although there were sex differences in discrimination and reversal phases, performance improved over time. We also observed sex-independent drinking group differences in win-stay and lose-shift strategies specific to the reversal phase. CONCLUSIONS: Females exhibit increased vulnerability to EtOH effects in early learning: there were sex-dependent EtOH effects on attentional measures during pretraining and discrimination phases. We also found sex-independent EtOH effects on exploration strategies during reversal. Future studies should aim to uncover the neural mechanisms for changes in attention and exploration in both acute and prolonged EtOH withdrawal.


Assuntos
Consumo de Bebidas Alcoólicas , Reversão de Aprendizagem/fisiologia , Animais , Comportamento de Escolha , Feminino , Masculino , Ratos , Ratos Long-Evans , Recompensa , Caracteres Sexuais
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