ABSTRACT Hepatic injuries in COVID-19 are not yet fully understood and indirect pathways (without viral replication in the liver) have been associated with the activation of vascular mechanisms of liver injury in humans infected with SARS-CoV-2. Golden Syrian hamsters are an effective model for experimental reproduction of moderate and self-limiting lung disease during SARS-CoV-2 infection. As observed in humans, this experimental model reproduces lesions of bronchointerstitial pneumonia and pulmonary vascular lesions, including endotheliitis (attachment of lymphoid cells to the luminal surface of endothelium). Extrapulmonary vascular lesions are well documented in COVID-19, but such extrapulmonary vascular lesions have not yet been described in the Golden Syrian hamster model of SARS-CoV-2 infection. The study aimed to evaluate microscopic liver lesions in Golden Syrian hamsters experimentally infected with SARS-CoV-2. In total, 38 conventional Golden Syrian hamsters, divided into infected group (n=24) and mock-infected group (n=14), were euthanized at 2-, 3-, 4-, 5-, 7-, 14-, and 15-days post infection with SARS-CoV-2. Liver fragments were evaluated by histopathology and immunohistochemical detection of SARS-CoV-2 Spike S2 antigens. The frequencies of portal vein endotheliitis, lobular activity, hepatocellular degeneration, and lobular vascular changes were higher among SARS-CoV-2-infected animals. Spike S2 antigen was not detected in liver. The main results indicate that SARS-CoV-2 infection exacerbated vascular and inflammatory lesions in the liver of hamsters with pre-existing hepatitis of unknown origin. A potential application of this animal model in studies of the pathogenesis and evolution of liver lesions associated with SARS-CoV-2 infection still needs further evaluation. COVID19 COVID 19 COVID-1 without SARSCoV2. SARSCoV2 SARSCoV SARS CoV 2. 2 selflimiting self limiting SARS-CoV- attachment endothelium. endothelium . endothelium) COVID19, 19, total 3 n=24 n24 n 24 (n=24 mockinfected mock n=14, n14 n=14 , 14 (n=14) 2, 2- 3, 3- 4, 4 4- 5, 5 5- 7, 7 7- 14, 14- 15days days 15 S antigens activity degeneration SARSCoV2infected SARSCoVinfected animals preexisting pre existing origin evaluation COVID1 1 COVID- SARS-CoV n=2 n2 (n=2 n1 n=1 (n=14 n= (n= (n=1 (n

Objective: To compare plasma concentrations of cannabidiol (CBD) following oral administration of two formulations of the drug (powder and dissolved in oil), and to evaluate the effects of these distinct formulations on responses to emotional stimuli in healthy human volunteers. Methods: In a randomized, double-blind, placebo-controlled, parallel-group design, 45 healthy male volunteers were randomly assigned to three groups of 15 subjects that received either 150 mg of CBD powder; 150 mg of CBD dissolved in corn oil; or placebo. Blood samples were collected at different times after administration, and a facial emotion recognition task was completed after 150 min. Results: There were no significant differences across groups in the subjective and physiological measures, nor in the facial emotion recognition task. However, groups that received the drug showed statistically significant differences in baseline measures of plasma CBD, with a significantly greater difference in favor of the oil formulation. Conclusion: When administered as a single 150-mg dose, neither formulation of oral CBD altered responses to emotional stimuli in healthy subjects. The oil-based CBD formulation resulted in more rapid achievement of peak plasma level, with an approximate fourfold increase in oral bioavailability.

Objective: To test the hypothesis that genetic variations of cannabinoid receptors contribute to the pathophysiology of cognitive deficits in schizophrenia. Methods: In this genetic association case-control study, cannabinoid receptor polymorphisms CNR1 rs12720071 and CNR2 rs2229579 were tested for association with neurocognitive performance in 69 patients with schizophrenia and 45 healthy controls. Neurocognition was assessed by the Brief Assessment of Cognition in Schizophrenia (BACS). Results: We found a consistent association between CNR1 rs12720071 polymorphism and the cognitive performance of patients in several cognitive domains. Patients with C/C polymorphism presented significantly worse performance in motor speed, verbal fluency, attention/processing speed and reasoning/problem solving. Conclusion: Although limited, our data support the hypothesis that CNR1 variations may be associated with the pathogenesis of cognitive deficits of schizophrenia.

Objective: The aim of the present study was to analyze the body sway response in specific phobia (SP) patients and healthy controls while viewing neutral, phobic, and disgusting images. Methods: The participants’ heart rate (HR) and skin conductance were also recorded during the procedure. Nineteen patients with arachnophobia and 19 healthy volunteers matched by age, gender, and years of education underwent a postural control test on a stabilometric platform. Results: The platform recorded increased body sway in the SP group when exposed to spider images (SPI). The SP group presented increases in most parameters (SD, velocity, frequency, area, p ≤ 0.05) when viewing pictures of the SPI category. Psychometric measures of subjective anxiety (State-Trait Anxiety Inventory, STAI) and physiological states (HR; skin conductance responses; spontaneous fluctuations in skin conductance) showed increased anxiety (p ≤ 0.05) in the SP group compared to healthy volunteers. High anxiety levels were observed throughout the assessment, including the task of exposure to SPI (p ≤ 0.05). No significant effect or correlation was found between skin conductance and body sway measures (p > 0.05). Conclusions: The results of the postural control test suggest the occurrence of a defensive escape response in SP, in agreement with previous evidence.

Resumo Objetivo O presente estudo prospectivo, randomizado e controlado foi realizado com 286 pacientes submetidos à artroplastia total primária do joelho (ATJ) com o objetivo de avaliar a eficácia da adição de antibiótico ao cimento ósseo como forma de prevenção da infecção pós-artroplastia (IPA). Métodos Os pacientes foram randomizados em dois grupos: cimento ósseo sem antibiótico (Sem ATB, n = 158) ou cimento com antibiótico (Com ATB, n = 128), ao qual foram adicionados 2g de Vancomicina para 40 g de cimento. Os pacientes foram acompanhados por 24 meses após a cirurgia. Resultados No que diz respeito aos dados demográficos pré-operatórios, a distribuição dos pacientes entre os grupos foi homogênea (p < 0,05). No período de 24 meses, a taxa global de infecção foi de 2,09% (6/286), não havendo diferença (odds ratio [OR] = 1,636; intervalo de confiança [IC] 95%: 0,294−9,080; p = 0,694) entre o grupo Com ATB (1,56%; 2/128) e Sem ATB (2,53%; 4/158). No grupo Sem ATB, a infecção foi causada por Staphylococcus aureus resistente à meticilina (MRSA, na sigla em inglês) (n = 2), S. aureus sensível à meticilina (MSSA, na sigla em inglês) (n = 1) e Eschirichia coli (n = 1). Proteus mirabilis e MSSA foram isolados dos pacientes do grupo Com ATB. Dentre as comorbidades, todos os pacientes com IPA eram hipertensos e não diabéticos. Dois pacientes com artrite reumatoide que desenvolveram IPA eram do grupo Com ATB. Conclusão O uso de cimento com ATB reduziu o número absoluto de infecções; porém, sem diferença estatística entre os grupos. Desta forma, o uso rotineiro não deve ser encorajado. Objective The present prospective, randomized and controlled study was conducted with 286 patients submitted to primary total knee arthroplasty (TKA) with the objective of evaluating the efficacy of the addition of antibiotics to bone cement as a way to prevent post arthroplasty infection (PAI). Methods The patients were randomized into two groups: bone cement without antibiotic (No ATB, n = 158) or cement with antibiotic (ATB, n = 128), in which 2 g of vancomycin was added to 40 g of cement. The patients were followed up for 24 months after surgery. Results Regarding preoperative demographic data, the distribution of patients between groups was homogeneous (p < 0.05). In the 24-month period, the overall infection rate was of 2.09% (6/286), with no difference (odds ratio [OR] = 1.636; 95% confidence interval [CI]: 0.294-9.080; p = 0.694) between the ATB group (1.56%; 2/128) and the No ATB group (2.53%; 4/158). In the No ATB group, the infection was caused by methicillin-resistant Staphylococcus aureus (MRSA) (n = 2), methicillin-sensitive S. aureus (MSSA) (n = 1) and Eschirichia coli (n = 1). Proteus mirabilis and MSSA were isolated from patients in the ATB group. Among the comorbidities, all patients with PAI were hypertensive and nondiabetic. Two rheumatoid arthritis patients who developed PAI were from the ATB group. Conclusion The use of cement with ATB reduced the absolute number of infections, but without statistical difference between the groups; thus, routine use should not be encouraged.

Abstract Objective The present prospective, randomized and controlled study was conducted with 286 patients submitted to primary total knee arthroplasty (TKA) with the objective of evaluating the efficacy of the addition of antibiotics to bone cement as a way to prevent post arthroplasty infection (PAI). Methods The patients were randomized into two groups: bone cement without antibiotic (No ATB, n = 158) or cement with antibiotic (ATB, n = 128), in which 2 g of vancomycin was added to 40 g of cement. The patients were followed up for 24 months after surgery. Results Regarding preoperative demographic data, the distribution of patients between groups was homogeneous (p < 0.05). In the 24-month period, the overall infection rate was of 2.09% (6/286), with no difference (odds ratio [OR] = 1.636; 95% confidence interval [CI]: 0.294−9.080; p = 0.694) between the ATB group (1.56%; 2/128) and the No ATB group (2.53%; 4/158). In the No ATB group, the infection was caused by methicillin-resistant Staphylococcus aureus (MRSA) (n = 2), methicillin-sensitive S. aureus (MSSA) (n = 1) and Eschirichia coli (n = 1). Proteus mirabilis and MSSA were isolated from patients in the ATB group. Among the comorbidities, all patients with PAI were hypertensive and nondiabetic. Two rheumatoid arthritis patients who developed PAI were from the ATB group. Conclusion The use of cement with ATB reduced the absolute number of infections, but without statistical difference between the groups; thus, routine use should not be encouraged.

Current pharmacotherapy of Parkinson’s disease (PD) is palliative and unable to modify the progression of neurodegeneration. Treatments that can improve patients’ quality of life with fewer side effects are needed, but not yet available. Cannabidiol (CBD), the major non-psychotomimetic constituent of cannabis, has received considerable research attention in the last decade. In this context, we aimed to critically review the literature on potential therapeutic effects of CBD in PD and discuss clinical and preclinical evidence supporting the putative neuroprotective mechanisms of CBD. We searched MEDLINE (via PubMed) for indexed articles published in English from inception to 2019. The following keywords were used: cannabis; cannabidiol and neuroprotection; endocannabinoids and basal ganglia; Parkinson’s animal models; Parkinson’s history; Parkinson’s and cannabidiol. Few studies addressed the biological bases for the purported effects of CBD on PD. Six preclinical studies showed neuroprotective effects, while three targeted the antidyskinetic effects of CBD. Three human studies have tested CBD in patients with PD: an open-label study, a case series, and a randomized controlled trial. These studies reported therapeutic effects of CBD on non-motor symptoms. Additional research is needed to elucidate the potential effectiveness of CBD in PD and the underlying mechanisms involved.

Currently, the pharmaceutical industry devotes great attention to drug degradation products because these compounds can offer risks to patients. A previous degradation study of betahistine (N-α-methyl-2-pyridylethylamine) conducted under different stress conditions detected three main impurities named A, B and C. Degradation products were analyzed by high-resolution mass spectrometry in electrospray source and time of flight analyzer (ESI-TOF) and nuclear magnetic resonance (NMR). Impurity mutagenicity was evaluated by Derek Nexus and Sarah Nexus softwares. Liquid chromatography hyphenate with tandem mass spectrometry (LC-MS/MS) analysis of the betahistine forced degradation sample indicated the presence of a new impurity, which was named impurity C1. 2D NMR experiments allowed the complete structural characterization of the new entity. The active pharmaceutical ingredient and degradation impurities were classified as inactive in the in silico mutagenic studies. Systematic investigation of a forced degradation sample led to the characterization of a new betahistine impurity. The in silico mutagenicity study of the betahistine degradation impurities may be useful in the risk assessment of the drug products.

Objective: Cannabidiol (CBD), one of the non-psychotomimetic compounds of Cannabis sativa, causes anxiolytic-like effects in animals, with typical bell-shaped dose-response curves. No study, however, has investigated whether increasing doses of this drug would also cause similar curves in humans. The objective of this study was to compare the acute effects of different doses of CBD and placebo in healthy volunteers performing a simulated public speaking test (SPST), a well-tested anxiety-inducing method. Method: A total of 57 healthy male subjects were allocated to receive oral CBD at doses of 150 mg (n=15), 300 mg (n=15), 600 mg (n=12) or placebo (n=15) in a double-blind procedure. During the SPST, subjective ratings on the Visual Analogue Mood Scale (VAMS) and physiological measures (systolic and diastolic blood pressure, heart rate) were obtained at six different time points. Results: Compared to placebo, pretreatment with 300 mg of CBD significantly reduced anxiety during the speech. No significant differences in VAMS scores were observed between groups receiving CBD 150 mg, 600 mg and placebo. Conclusion: Our findings confirm the anxiolytic-like properties of CBD and are consonant with results of animal studies describing bell-shaped dose-response curves. Optimal therapeutic doses of CBD should be rigorously determined so that research findings can be adequately translated into clinical practice.

RESUMO: As doenças dos cascos são as principais causas de claudicação em pequenos ruminantes, causando grande impacto no bem-estar dos animais e provocando sérias perdas econômicas com depreciação e abate de animais afetados. O objetivo do presente estudo foi determinar a ocorrência e caracterizar as doenças podais encontradas em oito rebanhos de ovinos com histórico de doenças podais pertencentes a oito municípios do estado da Bahia. Em cada visita, foram realizadas inspeções do rebanho, aplicação de um questionário de pesquisa e caracterização das doenças. No total, 600 ovinos foram inspecionados, realizando exame do casco em animais doentes para caracterizar as lesões, registrar a quantidade de doenças presentes por animal, o casco afetado e a quantidade de membros afetados. A ocorrência de doença de casco foi de 23,3% (140/600) variando de 12,8 a 55,5% por fazenda. Duzentos e vinte casos envolvendo nove doenças foram registrados. A pododermatite infecciosa foi a doença mais comum com 51,3% dos casos (113/220), 70% correspondente aos estágios avançados e terminais. A dermatite interdigital representou 27,7% dos casos; crescimento excessivo dos cascos 8,6%; doença da linha branca 3,2%; sola dupla 3,2%; granuloma do dígito 2,3%; hiperplasia interdigital 2,3%; úlcera de sola 0,9% e 0,4% de abcesso de pé. Os principais fatores predisponentes envolvidos na ocorrência das doenças foram a alta precipitação pluviométrica, condições de umidade do solo, currais e pastagens, manejo sanitário deficiente e falta de medidas preventivas (pedilúvio, quarentena, isolamento e vacinação), falhas de tratamento e baixa infra-estrutura da maioria das propriedades.

ABSTRACT: Foot diseases are the main causes of lameness in small ruminants, causing great impact on animal welfare and important economic losses due to depreciation and culling of affected animals. The aim of the present study was to characterize foot diseases found in eight flocks of sheep with a history of the ailment, that belonged to eight municipalities in the state of Bahia. At each visit, inspection of the flock, survey questionnaire, and characterization of diseases were performed. Altogether 600 sheep were inspected through foot examination in sick animals to characterize the injuries and record the diseases present per animal, as affected hooves and the number of affected limbs. The occurrence of foot disease was 23.3% (140/600) ranging from 12.8 to 55.5% per farm. Two hundred and twenty cases involving nine diseases were recorded. Foot rot was the most common disease with 51.3% of cases (113/220), 70% corresponding to advanced and terminal stages. Interdigital dermatitis represented 27.7% of the cases, excessive hoof growth 8.6%, white line disease 3.2%, double soles 3.2%, toe granuloma 2.3%, interdigital hyperplasia 2.3%, sole ulcers 0.9% and 0.4% foot abscess. The main predisposing factors involved in the genesis of diseases were the high rainfall precipitation, soil moisture conditions, pens and pastures, poor sanitary management and lack of preventive measures (footbath, quarantine, isolation and vaccination), treatment failures and low infrastructure of most properties.

ABSTRACT Abnormal multiplication of oral bacteria causes dental caries and dental plaque. These diseases continue to be major public health concerns worldwide, mainly in developing countries. In this study, the chemical composition and antimicrobial activity of the essential oil of Vitex agnus-castus leaves (VAC‒EO) collected in the North of Brazil against a representative panel of cariogenic bacteria were investigated. The antimicrobial activity of VAC-EO was evaluated in terms of its minimum inhibitory concentration (MIC) values by using the broth microdilution method in 96-well microplates. The chemical constituents of VAC-EO were identified by gas chromatography (GC‒FID) and gas chromatography‒mass spectrometry (GC‒MS). VAC‒EO displayed some activity against all the investigated oral pathogens; MIC values ranged from 15.6 to 200 μg/mL. VAC-EO had promising activity against Streptococcus mutans (MIC= 15.6 μg/mL), Lactobacillus casei (MIC= 15.6 μg/mL), and Streptococcus mitis (MIC= 31.2 μg/mL). The compounds 1,8-cineole (23.8%), (E)-β-farnesene (14.6%), (E)-caryophyllene (12.5%), sabinene (11.4%), and α-terpinyl acetate (7.7%) were the major chemical constituents of VAC‒EO. VAC-EO displays antimicrobial activity against cariogenic bacteria. The efficacy of VAC-EO against S. mutans is noteworthy and should be further investigated.

Resumo Objetivo: O objetivo deste estudo foi avaliar os achados de tomografia computadorizada de alta resolução (TCAR) em pacientes com diagnóstico de calcificação pulmonar metastática (CPM). Materiais e Métodos: Revisamos, retrospectivamente, os achados na TCAR de 23 casos de CPM [14 homens e 9 mulheres; idade média, 54,3 (intervalo, 26-89) anos]. Os pacientes foram examinados entre 2000 e 2014 em nove hospitais terciários no Brasil, Chile e Canadá. O diagnóstico foi estabelecido por estudo histopatológico em 18 pacientes e correlação clinicorradiológica em 5 pacientes. Dois radiologistas de tórax analisaram as imagens e chegaram a decisões por consenso. Resultados: Os achados predominantes na TCAR foram nódulos centrolobulares em vidro fosco (n = 14; 60,9%), consolidação com alta atenuação (n = 10; 43,5%), pequenos nódulos densos (n = 9; 39,1%), opacidades reticulares periféricas associadas com pequenos nódulos calcificados (n = 5; 21,7%) e opacidades em vidro fosco sem nódulos centrolobulares em vidro fosco (n = 5; 21,7%). Calcificação vascular na parede torácica foi encontrada em quatro casos e derrame pleural foi observado em cinco casos. As anormalidades foram bilaterais em 21 casos. Conclusão: CPM manifestou-se com três padrões principais na TCAR. O aspecto mais comum foram os nódulos centrolobulares em vidro fosco, frequentemente contendo calcificações, seguido de consolidação densa e de pequenos nódulos sólidos, a maioria deles calcificada. Também descrevemos o padrão de opacidades reticulares periféricas associadas a pequenos nódulos calcificados. Esses achados devem sugerir o diagnóstico de CPM no contexto de hipercalcemia.

Abstract Objective: The aim of this study was to evaluate the high-resolution computed tomography (HRCT) findings in patients diagnosed with metastatic pulmonary calcification (MPC). Materials and Methods: We retrospectively reviewed the HRCT findings from 23 cases of MPC [14 men, 9 women; mean age, 54.3 (range, 26-89) years]. The patients were examined between 2000 and 2014 in nine tertiary hospitals in Brazil, Chile, and Canada. Diagnoses were established by histopathologic study in 18 patients and clinical-radiological correlation in 5 patients. Two chest radiologists analyzed the images and reached decisions by consensus. Results: The predominant HRCT findings were centrilobular ground-glass nodules (n = 14; 60.9%), consolidation with high attenuation (n = 10; 43.5%), small dense nodules (n = 9; 39.1%), peripheral reticular opacities associated with small calcified nodules (n = 5; 21.7%), and ground-glass opacities without centrilobular ground-glass nodular opacity (n = 5; 21.7%). Vascular calcification within the chest wall was found in four cases and pleural effusion was observed in five cases. The abnormalities were bilateral in 21 cases. Conclusion: MPC manifested with three main patterns on HRCT, most commonly centrilobular ground-glass nodules, often containing calcifications, followed by dense consolidation and small solid nodules, most of which were calcified. We also described another pattern of peripheral reticular opacities associated with small calcified nodules. These findings should suggest the diagnosis of MPC in the setting of hypercalcemia.

RESUMO Objetivo: Validar a quantificação de T-cell receptor excision circles (TRECs) e kappa-deleting recombination circles (KRECs) por reação em cadeia de polimerase (polymerase chain reaction, PCR) em tempo real (qRT-PCR), para triagem neonatal de imunodeficiências primárias que cursam com defeitos nas células T e/ou B no Brasil. Métodos: Amostras de sangue de recém-nascidos (RN) e controles foram coletadas em papel-filtro. O DNA foi extraído e os TRECs e KRECs foram quantificados por reação duplex de qRT-PCR. O valor de corte foi determinado pela análise de Receiver Operating Characteristics Curve, utilizando-se o programa Statistical Package for the Social Sciences (SSPS) (IBM®, Armonk, NY, EUA). Resultados: 6.881 amostras de RN foram analisadas quanto à concentração de TRECs e KRECs. Os valores de TRECs variaram entre 1 e 1.006 TRECs/µL, com média e mediana de 160 e 139 TRECs/µL, respectivamente. Três amostras de pacientes diagnosticados com imunodeficiência grave combinada (severe combined immunodeficiency, SCID) apresentaram valores de TRECs abaixo de 4/µL e um paciente com Síndrome de DiGeorge apresentou TRECs indetectáveis. Os valores de KRECs encontraram-se entre 10 e 1.097 KRECs/µL, com média e mediana de 130 e 108 KRECs/µL, e quatro pacientes com diagnóstico de agamaglobulinemia tiveram resultados abaixo de 4 KRECs/µL. Os valores de corte encontrados foram 15 TRECs/µL e 14 KRECs/µL, e foram estabelecidos de acordo com a análise da Receiver Operating Characteristics Curve, com sensibilidade de 100% para detecção de SCID e agamaglobulinemia, respectivamente. Conclusões: A quantificação de TRECs e KRECs foi capaz de diagnosticar crianças com linfopenias T e/ou B em nosso estudo, validando a técnica e dando o primeiro passo para a implementação da triagem neonatal em grande escala no Brasil.

ABSTRACT Objective: To validate the quantification of T-cell receptor excision circles (TRECs) and kappa-deleting recombination excision circles (KRECs) by real-time polymerase chain reaction (qRT-PCR) for newborn screening of primary immunodeficiencies with defects in T and/or B cells in Brazil. Methods: Blood samples from newborns and controls were collected on filter paper. DNA was extracted and TRECs, and KRECs were quantified by a duplex real-time PCR. The cutoff values were determined by receiver operating characteristic curve analysis using SPSS software (IBM®, Armonk, NY, USA). Results: Around 6,881 samples from newborns were collected and TRECs and KRECs were quantified. The TRECs values ranged between 1 and 1,006 TRECs/µL, with mean and median of 160 and 139 TRECs/µL, respectively. Three samples from patients with severe combined immunodeficiency (SCID) showed TRECs below 4/µL and a patient with DiGeorge syndrome showed undetectable TRECs. KRECs values ranged from 10 to 1,097 KRECs/µL, with mean and median of 130 and 108 KRECs/µL. Four patients with agammaglobulinemia had results below 4 KRECs/µL. The cutoff values were 15 TRECs/µL and 14 KRECs/µL and were established according to the receiver operating characteristic curve analysis, with 100% sensitivity for SCID and agammaglobulinemia detection, respectively. Conclusions: Quantification of TRECs and KRECs was able to diagnose children with T- and/or B-cell lymphopenia in our study, which validated the technique in Brazil and enabled us to implement the newborn screening program for SCID and agammaglobulinemia.

RESUMO Objetivou-se, com este trabalho, avaliar as variáveis agronômicas em função dos efeitos de diferentes níveis de desfolha nas fases fenológicas de duas cultivares de soja. O experimento foi conduzido durante a safra 2011/12 e o delineamento experimental utilizado foi o de blocos casualizados, com três repetições, em esquema fatorial 2 x 4 x 5, ou seja, duas cultivares foram submetidas à desfolha nos estádios V4, V9, R3 e R5 com porcentagens de 0, 25, 50, 75 e 100%. A cultivar 'NK 7059RR' apresentou menor sensibilidade à desfolha do que a cultivar 'NA 4990RG'. Níveis de 25% de desfolha reduziram a produtividade da cultivar 'NA 4990RG' enquanto que níveis de 75 e 100% reduzem o número de grãos por vagem nas duas cultivares. As desfolhas realizadas no estádio V4 acarretam em menor produtividade do que quando realizadas no estádio V9; os estádios mais sensíveis à desfolha são R3 e R5, ocorrendo maior redução no potencial produtivo da soja.

ABSTRACT The objective of this study was to evaluate the agronomic variables due to the effects of different levels of defoliation in the phenological phases of two soybean cultivars. The experiment was conducted during the 2011/2012 season, in a randomized block design with three replicates, in a 2 x 4 x 5 factorial scheme. Two cultivars were exposed to defoliations of 0, 25, 50, 75 and 100% at the stages of V4, V9, R3 and R5. The cultivar 'NK 7059RR' showed less sensitivity to defoliation than the cultivar 'IN 4990RG'. 25% defoliation levels reduced the yield of the cultivar 'IN 4990RG', while levels of 75 and 100% reduce the number of grains per pod in both cultivars. The defoliation performed in the V4 stage lead to lower grain yield than defoliation in V9. The most sensitive stages to defoliation are R3 and R5, where there is a greater reduction in the production potential of soybeans.