Phenotype of BTK-lacking myeloid cells during prolonged COVID-19 and upon convalescent plasma.

XLA patient with 7-month course of COVID-19 with persistent plasma SARS-CoV-2 load revealed a sustained non-inflammatory profile of myeloid cells in association with contained severity of disease, arguing in favor of the use of BTK inhibitors in SARS-COV-2 infection.

Monitoring of the Forgotten Immune System during Critical Illness-A Narrative Review.

Immune organ failure is frequent in critical illness independent of its cause and has been acknowledged for a long time. Most patients admitted to the ICU, whether featuring infection, trauma, or other tissue injury, have high levels of alarmins expression in tissues or systemically which then activate innate and adaptive responses. Although necessary, this response is frequently maladaptive and leads to organ dysfunction. In addition, the counter-response aiming to restore homeostasis and repair injury can also be detrimental and contribute to persistent chronic illness. Despite intensive research on this topic in the last 40 years, the immune system is not routinely monitored in critical care units. In this narrative review we will first discuss the inflammatory response after acute illness and the players of maladaptive response, focusing on neutrophils, monocytes, and T cells. We will then go through commonly used biomarkers, like C-reactive protein, procalcitonin and pancreatic stone protein (PSP) and what they monitor. Next, we will discuss the strengths and limitations of flow cytometry and related techniques as an essential tool for more in-depth immune monitoring and end with a presentation of the most promising cell associated markers, namely HLA-DR expression on monocytes, neutrophil expression of CD64 and PD-1 expression on T cells. In sum, immune monitoring critically ill patients is a forgotten and missing piece in the monitoring capacity of intensive care units. New technology, including bed-side equipment and in deep cell phenotyping using emerging multiplexing techniques will likely allow the definition of endotypes and a more personalized care in the future.

SARS-CoV2 pneumonia recovery is linked to expansion of innate lymphoid cells type 2 expressing CCR10.

Accelerate lung repair in SARS-CoV-2 pneumonia is essential for pandemic handling. Innate lymphoid cells (ILCs) are likely players, given their role in mucosal protection and tissue homeostasis. We studied ILC subpopulations at two time points in a cohort of patients admitted in the hospital due to SARS-CoV-2 infection. COVID-19 patients with moderate/severe respiratory failure featured profound depletion of circulating ILCs at hospital admission, in agreement with overall lymphocyte depletion. However, ILCs recovered in direct correlation with lung function improvement as measured by oxygenation index and in negative association with inflammatory and lung/endothelial damage markers like RAGE. While both ILC1 and ILC2 expanded, ILC2 showed the most striking phenotype changes, with CCR10 upregulation in strong correlation with these parameters. Overall, CCR10+ ILC2 emerge as relevant contributors to SARS-CoV-2 pneumonia recovery.

Acute HIV-1 and SARS-CoV-2 Infections Share Slan+ Monocyte Depletion-Evidence from an Hyperacute HIV-1 Case Report.

Monocytes are key modulators in acute viral infections, determining both inflammation and development of specific B- and T-cell responses. Recently, these cells were shown to be associated to different SARS-CoV-2 infection outcome. However, their role in acute HIV-1 infection remains unclear. We had the opportunity to evaluate the mononuclear cell compartment in an early hyper-acute HIV-1 patient in comparison with an untreated chronic HIV-1 and a cohort of SARS-CoV-2 infected patients, by high dimensional flow cytometry using an unsupervised approach. A distinct polarization of the monocyte phenotype was observed in the two viral infections, with maintenance of pro-inflammatory M1-like profile in HIV-1, in contrast to the M2-like immunosuppressive shift in SARS-CoV-2. Noticeably, both acute infections had reduced CD14low/-CD16+ non-classical monocytes, with depletion of the population expressing Slan (6-sulfo LacNac), which is thought to contribute to immune surveillance through pro-inflammatory properties. This depletion indicates a potential role of these cells in acute viral infection, which has not previously been explored. The inflammatory state accompanied by the depletion of Slan+ monocytes may provide new insights on the critical events that determine the rate of viral set-point in acute HIV-1 infection and subsequent impact on transmission and reservoir establishment.

Influence of position and angulation of a voice prosthesis on the aerodynamics of the pseudo-glottis.

The use of a tracheoesophageal valve, also known as voice prosthesis, is currently the most appealing solution for recovering the ability to speak in subjects who have undergone a total laryngectomy. The prosthesis allows the passage of air from the trachea to the esophagus, thereby promoting the flow-induced vibration of the subject's pharyngoesophageal segment. In turn, the pharyngoesophageal segment modulates the air flow from the lungs into the subject's vocal tract, acting as an alternative source of acoustic energy to generate voice. The vibration of the pharyngoesophageal segment will likely depend on the aerodynamic forces acting on its wall, which will be defined by the flow characteristics downstream from the valve's outlet. Previous works have investigated the pressure drop across different prosthesis designs with both in-vitro and in-vivo experiments. Nevertheless, the aerodynamic aspects of the flow in the tracheoesophageal region have only been investigated experimentally in an idealized geometry. This work investigates the influence of the prosthesis position on the aerodynamic behavior of the pharyngoesophageal segment in terms of wall pressure distribution and characteristics of the velocity field. The investigations were carried out with a static model of the tracheoesophageal region based on the finite volume method and a Reynolds-averaged Navier-Stokes solver. The geometry of the system was based on computed tomography images obtained from laryngectomized subjects during phonation at different voice registers and included the geometry of a commercially available voice prosthesis. The results suggest that the position and angulation of the voice prosthesis have a minor influence on the pressure loss along the tracheoesophageal segment and on the pressure distribution on the pharyngoesophageal segment's wall.

Severe COVID-19 Recovery Is Associated with Timely Acquisition of a Myeloid Cell Immune-Regulatory Phenotype.

After more than one year since the COVID-19 outbreak, patients with severe disease still constitute the bottleneck of the pandemic management. Aberrant inflammatory responses, ranging from cytokine storm to immune-suppression, were described in COVID-19 and no treatment was demonstrated to change the prognosis significantly. Therefore, there is an urgent need for understanding the underlying pathogenic mechanisms to guide therapeutic interventions. This study was designed to assess myeloid cell activation and phenotype leading to recovery in patients surviving severe COVID-19. We evaluated longitudinally patients with COVID-19 related respiratory insufficiency, stratified according to the need of intensive care unit admission (ICU, n = 11, and No-ICU, n = 9), and age and sex matched healthy controls (HCs, n = 11), by flow cytometry and a wide array of serum inflammatory/immune-regulatory mediators. All patients featured systemic immune-regulatory myeloid cell phenotype as assessed by both unsupervised and supervised analysis of circulating monocyte and dendritic cell subsets. Specifically, we observed a reduction of CD14lowCD16+ monocytes, and reduced expression of CD80, CD86, and Slan. Moreover, mDCs, pDCs, and basophils were significantly reduced, in comparison to healthy subjects. Contemporaneously, both monocytes and DCs showed increased expression of CD163, CD204, CD206, and PD-L1 immune-regulatory markers. The expansion of M2-like monocytes was significantly higher at admission in patients featuring detectable SARS-CoV-2 plasma viral load and it was positively correlated with the levels of specific antibodies. In No-ICU patients, we observed a peak of the alterations at admission and a progressive regression to a phenotype similar to HCs at discharge. Interestingly, in ICU patients, the expression of immuno-suppressive markers progressively increased until discharge. Notably, an increase of M2-like HLA-DRhighPD-L1+ cells in CD14++CD16- monocytes and in dendritic cell subsets was observed at ICU discharge. Furthermore, IFN-γ and IL-12p40 showed a decline over time in ICU patients, while high values of IL1RA and IL-10 were maintained. In conclusion, these results support that timely acquisition of a myeloid cell immune-regulatory phenotype might contribute to recovery in severe systemic SARS-CoV-2 infection and suggest that therapeutic agents favoring an innate immune system regulatory shift may represent the best strategy to be implemented at this stage.

Generation of Differentiating and Long-Living Intestinal Organoids Reflecting the Cellular Diversity of Canine Intestine.

Functional intestinal disorders constitute major, potentially lethal health problems in humans. Consequently, research focuses on elucidating the underlying pathobiological mechanisms and establishing therapeutic strategies. In this context, intestinal organoids have emerged as a potent in vitro model as they faithfully recapitulate the structure and function of the intestinal segment they represent. Interestingly, human-like intestinal diseases also affect dogs, making canine intestinal organoids a promising tool for canine and comparative research. Therefore, we generated organoids from canine duodenum, jejunum and colon, and focused on simultaneous long-term expansion and cell differentiation to maximize applicability. Following their establishment, canine intestinal organoids were grown under various culture conditions and then analyzed with respect to cell viability/apoptosis and multi-lineage differentiation by transcription profiling, proliferation assay, cell staining, and transmission electron microscopy. Standard expansion medium supported long-term expansion of organoids irrespective of their origin, but inhibited cell differentiation. Conversely, transfer of organoids to differentiation medium promoted goblet cell and enteroendocrine cell development, but simultaneously induced apoptosis. Unimpeded stem cell renewal and concurrent differentiation was achieved by culturing organoids in the presence of tyrosine kinase ligands. Our findings unambiguously highlight the characteristic cellular diversity of canine duodenum, jejunum and colon as fundamental prerequisite for accurate in vitro modelling.

Localization properties of a two-channel 3D Anderson model.

We study two coupled 3D lattices, one of them featuring uncorrelated on-site disorder and the other one being fully ordered, and analyze how the interlattice hopping affects the localization-delocalization transition of the former and how the latter responds to it. We find that moderate hopping pushes down the critical disorder strength for the disordered channel throughout the entire spectrum compared to the usual phase diagram for the 3D Anderson model. In that case, the ordered channel begins to feature an effective disorder also leading to the emergence of mobility edges but with higher associated critical disorder values. Both channels become pretty much alike as their hopping strength is further increased, as expected. We also consider the case of two disordered components and show that in the presence of certain correlations among the parameters of both lattices, one obtains a disorder-free channel decoupled from the rest of the system.

Fast and slow dynamics for classical and quantum walks on mean-field small world networks.

This work investigates the dynamical properties of classical and quantum random walks on mean-field small-world (MFSW) networks in the continuous time version. The adopted formalism profits from the large number of exact mathematical properties of their adjacency and Laplacian matrices. Exact expressions for both transition probabilities in terms of Bessel functions are derived. Results are compared to numerical results obtained by working directly the Hamiltonian of the model. For the classical evolution, any infinitesimal amount of disorder causes an exponential decay to the asymptotic equilibrium state, in contrast to the polynomial behavior for the homogeneous case. The typical quantum oscillatory evolution has been characterized by local maxima. It indicates polynomial decay to equilibrium for any degree of disorder. The main finding of the work is the identification of a faster classical spreading as compared to the quantum counterpart. It stays in opposition to the well known diffusive and ballistic for, respectively, the classical and quantum spreading in the linear chain.

Thermodynamic framework for the ground state of a simple quantum system.

The ground state of a two-level system (associated with probabilities p and 1-p, respectively) defined by a general Hamiltonian H[over ̂]=H[over ̂]_{0}+λV[over ̂] is studied. The simple case characterized by λ=0, whose Hamiltonian H[over ̂]_{0} is represented by a diagonal matrix, is well established and solvable within Boltzmann-Gibbs statistical mechanics; in particular, it follows the third law of thermodynamics, presenting zero entropy (S_{BG}=0) at zero temperature (T=0). Herein it is shown that the introduction of a perturbation λV[over ̂] (λ>0) in the Hamiltonian may lead to a nontrivial ground state, characterized by an entropy S[p] (with S[p]≠S_{BG}[p]), if the Hermitian operator V[over ̂] is represented by a 2×2 matrix, defined by nonzero off-diagonal elements V_{12}=V_{21}=-z, where z is a real positive number. Hence, this new term in the Hamiltonian, presenting V_{12}≠0, may produce physically significant changes in the ground state, and especially, it allows for the introduction of an effective temperature θ (θ∝λz), which is shown to be a parameter conjugated to the entropy S. Based on this, one introduces an infinitesimal heatlike quantity, δQ=θdS, leading to a consistent thermodynamic framework, and by proposing an infinitesimal form for the first law, a Carnot cycle and thermodynamic potentials are obtained. All results found are very similar to those of usual thermodynamics, through the identification T↔θ, and particularly the form for the efficiency of the proposed Carnot Cycle. Moreover, S also follows a behavior typical of a third law, i.e., S→0, when θ→0.

An Fc-optimized CD133 antibody for induction of NK cell reactivity against myeloid leukemia.

Antibody-dependent cellular cytotoxicity (ADCC) of natural killer (NK) cells largely contributes to the success of monoclonal antibody (mAb) treatment in cancer. As no antibodies are clinically available for immunotherapy of myeloid leukemias (MLs), we aimed to develop an Fc-optimized CD133 mAb for induction of NK ADCC against MLs. When comparing different available CD133 mAbs, no difference was observed with regard to binding to primary chronic myeloid leukemia cells. However, clone 293C3 recognized acute myeloid leukemia (AML) cells in a substantially higher percentage of patient cases and was thus chosen to generate chimeric mAbs with either wild-type Fc part (293C3-WT) or a variant containing amino-acid exchanges (S239D/I332E) to enhance affinity to CD16 on NK cells (293C3-SDIE). In vitro, treatment with 293C3-SDIE significantly enhanced activation, degranulation and lysis of primary CD133-positive AML cells by allogeneic and autologous NK cells as compared with its wild-type counterpart. In line with the observed lower expression levels of CD133 on healthy cells compared with malignant hematopoietic cells, 293C3-SDIE caused no relevant toxicity towards committed hematopoietic progenitor cells. In a NOD.Cg-PrkdcscidIL2rgtmWjl/Sz xenotransplantation model, 293C3-SDIE facilitated elimination of patient AML cells by human NK cells. Thus, 293C3-SDIE constitutes an attractive immunotherapeutic compound, in particular for elimination of minimal residual disease in the context of allogeneic stem cell transplantation in AML.

Virulence profile and genetic variability of Staphylococcus aureus isolated from artisanal cheese.

The objectives of this study were to characterize Staphylococcus aureus isolated from artisanal and industrialized Minas frescal cheeses, to determine their antimicrobial susceptibility profile as well as the genetic similarity among the isolates. The isolates were also tested for staphylococcal enterotoxin genes and other virulence factors. Fifty-six artisanal raw milk cheeses sold at street fairs and 10 industrialized cheeses commercialized in supermarkets of Goiânia, Goiás, were analyzed. Staphylococcus aureus was confirmed in 19 samples (33.9%) of artisanal cheese by detection of femA gene, in which 29 isolates were obtained. These isolates were submitted to the antimicrobial susceptibility test and classified into 9 different profiles (A-I). Thirteen isolates (44.8) were resistant to penicillin and 3 (10.3) to tetracycline, with 2 (7.4) resistant to both. The multiplex PCR technique was performed to detect virulence genes that code for the production of hemolysins (Hla and Hlb), toxic shock syndrome toxin (TSST-1), exfoliative toxins (ETa and ETb), and staphylococcal enterotoxins [SE; SEA-SEE, SEG-SEJ, SEM-SEO]. All the isolates amplified for the hla gene and 14 (48.3%) for the hlb gene. The seh gene was the most frequently detected (n=11, 37.9%), followed by seo gene (n=3; 10.3%). In one isolate (3.4%), 4 enterotoxins genes were detected, and in another, 6 (3.4%) were detected. The comparison performed by pulsed-field gel electrophoresis of the 29 isolates revealed 18 genotypic profiles, which were grouped into 5 clusters. The genotyping found high genetic similarity among the isolates. Identical isolates were obtained from different samples and one sample showed more than one genetically different isolate. The high prevalence of S. aureus in the Minas Frescal cheese samples, as well as the detection of toxin encoding genes identified in this study, warns of the necessity to reduce the contamination levels in this type of cheese through monitoring and controlling the production and trade of the product.

Intestinal Organoids-Current and Future Applications.

Recent technical advances in the stem cell field have enabled the in vitro generation of complex structures resembling whole organs termed organoids. Most of these approaches employ culture systems that allow stem cell-derived or tissue progenitor cells to self-organize into three-dimensional (3D)-structures. Since organoids can be grown from different species (human, mouse, cat, dog), organs (intestine, kidney, brain, liver), and from patient-derived induced pluripotent stem cells, they create significant prospects for modelling development and diseases, for toxicology and drug discovery studies, and in the field of regenerative medicine. Here, we report on intestinal stem cells, organoid culture, organoid disease modeling, transplantation, specifically covering the current and future uses of this exciting new insight model to the field of veterinary medicine.

Consistent thermodynamic framework for interacting particles by neglecting thermal noise.

An effective temperature θ, conjugated to a generalized entropy s(q), was introduced recently for a system of interacting particles. Since θ presents values much higher than those of typical room temperatures T≪θ, the thermal noise can be neglected (T/θ≃0) in these systems. Moreover, the consistency of this definition, as well as of a form analogous to the first law of thermodynamics, du=θds(q)+δW, were verified lately by means of a Carnot cycle, whose efficiency was shown to present the usual form, η=1-(θ(2)/θ(1)). Herein we explore further the heat contribution δQ=θds(q) by proposing a way for a heat exchange between two such systems, as well as its associated thermal equilibrium. As a consequence, the zeroth principle is also established. Moreover, we consolidate the first-law proposal by following the usual procedure for obtaining different potentials, i.e., applying Legendre transformations for distinct pairs of independent variables. From these potentials we derive the equation of state, Maxwell relations, and define response functions. All results presented are shown to be consistent with those of standard thermodynamics for T>0.

Carnot cycle for interacting particles in the absence of thermal noise.

A thermodynamic formalism is developed for a system of interacting particles under overdamped motion, which has been recently analyzed within the framework of nonextensive statistical mechanics. It amounts to expressing the interaction energy of the system in terms of a temperature θ, conjugated to a generalized entropy s(q), with q = 2. Since θ assumes much higher values than those of typical room temperatures T ≪ θ, the thermal noise can be neglected for this system (T/θ ≃ 0). This framework is now extended by the introduction of a work term δW which, together with the formerly defined heat contribution (δ Q = θ ds(q)), allows for the statement of a proper energy conservation law that is analogous to the first law of thermodynamics. These definitions lead to the derivation of an equation of state and to the characterization of s(q) adiabatic and θ isothermic transformations. On this basis, a Carnot cycle is constructed, whose efficiency is shown to be η = 1-(θ(2)/θ(1)), where θ(1) and θ(2) are the effective temperatures of the two isothermic transformations, with θ(1)>θ(2). The results for a generalized thermodynamic description of this system open the possibility for further physical consequences, like the realization of a thermal engine based on energy exchanges gauged by the temperature θ.

EVI-1 modulates leukemogenic potential and apoptosis sensitivity in human acute lymphoblastic leukemia.

The transcriptional regulator ecotropic viral integration site-1 (EVI-1) has mainly been studied for its role in myeloid malignancies, in which high EVI-1 levels are associated with particularly aggressive disease. The role of EVI-1 in lymphoid cells, however, is largely unknown. Here we show that EVI-1 is indeed expressed in lymphoid malignancies such as acute lymphoblastic leukemia (ALL) and a subset of chronic lymphocytic leukemia. Expression data from pediatric ALL further suggest that high EVI-1 levels are associated with poor prognosis. Suppression of EVI-1 expression by RNA interference reduces cell growth and enhances apoptosis sensitivity in response to various stimuli in lymphoblastic leukemia cells. At the molecular level, EVI-1 modulates expression of several apoptosis-related genes (such as BCL2, BCL-x, XIAP, NOXA, PUMA, TRAIL-R1). Furthermore, EVI-1 knockdown strongly impairs in vivo engraftment of lymphoblastic leukemia cells upon transplantation in immune-permissive NOD/SCID/IL2Rγ(null) mice, conferring a survival benefit when compared with mice transplanted with control cells. Thus, our data show that EVI-1 is expressed not only in myeloid but also in lymphoid leukemias, and contributes to the leukemogenic potential and apoptosis resistance of ALL cells.

Determinação de hemogregarina em Boa constrictor constrictor mantidos em cativeiro / Determination of hemogregarine in Boa constrictor constrictor kept in captivity

O presente estudo teve como objetivo determinar a presença de hemogregarina em boídeos mantidos em cativeiro no Estado do Pará, bem como, relacionar a hemoparasitose com pre-disposição sexual, alterações clínicas e hematológicas e a presença de ectoparasitos. Esta pesquisa teve autorização do Sistema de Autorização e Informação em Biodiversidade do Instituto Brasileiro do Meio Ambiente e dos Recursos Naturais Renováveis para ser realizado. Utilizaram-se 19 serpentes da família Boidae mantidas em cativeiro, pertencentes ao "Museu Paraense Emilio Goeldi" (Belém/PA) e "Sítio Xerimbabo" (Santo Antônio do Tauá/PA). A pesquisa de hemogregarina foi realizada em esfregaços sanguíneos examinados no aumento de 400x, enquanto que a parasitemia foi determinada contando- se 550 hemácias em aumento de 1000x. Do total de animais estudados (n=19), nove encontraram-se parasitados (47,36%), não havendo correlação entre presença de hemogregarina, pré-disposição sexual, alterações clínicas e hematológicas nas serpentes hospedeiras. A correlação da hemoparasitose foi detectada apenas quanto à presença de ectoparasitas nas serpentes, no entanto, estudos adicionais são necessários para verificar a prevalência de hemogregarinas em animais mantidos em cativeiro no Estado do Pará, visto que, existe grande lacuna de dados na literatura veterinária especializada no que diz respeito à fauna da região amazônica.

We aimed to determine hemogregarines presence in snakes of the Boidae family kept in captivity in Pará (PA), Brazil, and to relate it with sex, clinical and hematological and ectoparasitism. This study had authorization from Sisbio/IBAMA to be done. Nineteen Boa constrictor snakes were used, belonging to the "Museu Paraense Emílio Goeldi" (Belém/ PA) and "Xerimbabo Farm" (Santo Antônio do Tauá/PA). Blood smears were examined with 400x magnification, while the parasitemia percentage was determined by counting 550 red blood cells with 1000x magnification. From the snakes studied (n=19), nine were parasitized (47.36%) and there was no correlation between hemogregarines presence, sex, clinical and hematological changes. Hemoparasitosis correlation was detected only with the ectoparasites presence; however further studies are needed to determine the real hemogregarines prevalence in snakes kept in captivity in Pará, since there is a huge gap of data in the veterinary specialized literature about the fauna of the Amazon region.

Effective-temperature concept: a physical application for nonextensive statistical mechanics.

The H-theorem [(df/dt) ≤ 0] for a free-energy functional, f = u-θs (with u and s representing, respectively, the internal energy and a generalized entropy of a given physical system), has been proven previously by making use of a nonlinear Fokker-Planck equation. Herein we focus on a nonlinear Fokker-Planck equation derived by means of a coarse-graining procedure on the equations of motion of a system of interacting vortices, under overdamped motion, in the absence of thermal noise (T = 0). In this case, we show that the parameter θ is directly related to the density as well as to the interactions among vortices. Generalized quantities such as entropy, internal energy, free energy, and heat capacity are analyzed for varying θ: important relations and physical behavior analogous to those of standard thermodynamics are found, showing that θ plays the role of an effective temperature. Estimates of θ in typical physical situations of different type-II superconductors are presented; in addition to this, possible experimental procedures for varying θ are proposed.

[Churg-Strauss syndrome: a disabling disease]. / Síndrome de churg-strauss: uma doença incapacitante.

Churg-Strauss syndrome (CSS) is an infrequent vasculitis that affects small to medium-sized vessels. We describe a 51 year-old-female admitted to our inpatient unit with bullae on her right foot and forearm with pain, paresthesias and impotence of the foot. There was rapid clinical deterioration with lost of gait and peripheral eosinophilia. Histopathology showed many extravascular eosinophils. Bone marrow had an increased number of eosinophils and their precursors with no neoplastic cells infiltration. Electromyogram revealed mononeuritis multiplex with bilateral sciatic and right femoral nerve involvement. She fulfilled the eligibility criteria of American College of Rheumatology (ACR) and Chapell Hill Conference Consensus (CHCC) of CSS so corticosteroids and cyclophosphamide and rehabilitation program were begun with good clinical and laboratorial response. This report illustrates the importance of identifying atypical cutaneous features of CSS for the early diagnosis of this rare condition and the role of a multidisciplinary team in this multissystemic disease.

Desenvolvimento de um modelo experimental de hemodiálise em cães / Development of a dog model of hemodialysis

To develop a model of hemodialysis (HD), 18 healthy dogs, without a defined breed, males, weighing 7-14 kg, were studied. A double lumen catheter was inserted into the jugular vein for vascular access. HD sessions, totalizing 5 for each dog, were performed with a proportional HD machine, controlled isovolemic ultrafiltration, standard dialysis solution and bicarbonate buffer. Sodium profile and sodium heparin were used. During HD sessions the dogs were kept anesthetized (levomepromazine and propofol). Hematological and biochemistry data, blood gas analysis, systemic arterial blood pressure, and activated clotting time were evaluated. Serum biochemistry e blood gas analysis showed, respectively, sodium and SO2 maintenance. Systemic blood pressure kept sustained during HD sessions. It could be concluded that it was possible to develop a HD dog model that is a safe and viable technique to be used in chronic renal failure patients.

Com o objetivo de desenvolver um modelo de hemodiálise (HD) em cães, foram estudados 18 animais, sem raça definida, machos, clinicamente sadios, com peso corporal variando entre sete e 14 kg. O acesso vascular foi obtido através de implantação do cateter de duplo lúmen em veia jugular externa. As sessões de HD, em número de cinco por animal, com até três horas de duração, foram realizadas em hemodialisadora de sistema proporcional com ultrafiltração (UF) controlada, com solução dialisante padrão e tampão bicarbonato. A UF foi ajustada para HD isovolêmica, utilizou-se perfil de sódio, e para anticoagulação heparina sódica. Os animais foram mantidos anestesiados com cloridrato de levomepromazina e propofol. Foram avaliados dados hematológicos, bioquímicos, hemogasometria, pressão arterial sistêmica e tempo de coagulação ativado. Foi observada diminuição do número global de hemácias, volume globular, hemoglobina e leucócitos. Em relação aos exames bioquímicos, houve manutenção nos níveis de sódio sérico, e quanto à hemogasometria, a manutenção da SO2. A pressão arterial sistêmica manteve-se constante. Os resultados obtidos no presente trabalho permitiram concluir que foi possível o desenvolvimento do modelo proposto e mostrou que a HD em cães é um método viável e seguro, que poderá contribuir para o tratamento clínico da insuficiência renal nesta espécie.