Hematological and biochemical parameters of premature kids of goats subjected to different dexamethasone protocols / Parâmetros hematológicos e bioquímicos de cabritos prematuros de cabras submetidas a diferentes protocolos de dexametasona

Corticosteroid therapy has been used for ruminants to allow lung maturation and the birth of premature babies. However, when considering laboratory analyses of these animals, very little data is available regarding hematological and biochemical patterns, especially for premature goats, and the effects of corticotherapy on these parameters are unknown. In this context, the objective of this study was to evaluate the hematological and biochemical parameters during the first hours of life of premature kids from goats subjected to different dexamethasone protocols. For this, the goats were divided into four groups: group I, goats that received 20 mg of dexamethasone at 139 days of gestation; group II, 2 mg of dexamethasone from the 133rd to 136th day of gestation, 4 mg from the 137th to 139th, and 20 mg on the 140th; group III, 16 mg of dexamethasone from the 139th day, with repeated doses every 12 h until elective surgery; and group IV, goats that received 4, 8, 16, and 20 mg of dexamethasone at 137, 138, 139, and 140 days of gestation, respectively. Blood samples were obtained at birth (T0h) and after 1 (T1h), 12 (T12h), 24 (T24h), and 48 h (T48h) of life for hemogram and serum biochemistry assessment of urea, creatinine, total protein (PT), and gamma-glutamyltransferase (GGT). PT levels and GGT activity were lower at birth in all groups and rose after colostrum ingestion. The creatinine values for all the experimental groups did not differ between T0h and T1h; however, they decreased in the subsequent moments. Except for group I, urea concentrations were higher at T48h than at T1h. The red blood cell, hemoglobin, hematocrit, and mean corpuscular hemoglobin counts decreased over time. The total leukocyte count behaved differently in different experimental groups, and was influenced by the levels of dexamethasone, mainly due to the change in the counts of segmented neutrophils and lymphocytes. It was concluded that significant changes in the hematological and biochemical parameters occur in the first hours of life of premature kids, and that the treatment of goats with dexamethasone can affect these parameters in a dose-dependent manner.

A corticoterapia tem sido empregada em ruminantes com o objetivo de permitir a maturação pulmonar e o nascimento de filhotes prematuros. Entretanto, ao se considerar análises laboratoriais desses animais, pouquíssimos dados estão disponíveis quanto aos padrões hematológicos e bioquímicos, especialmente em caprinos prematuros, e tampouco se sabe sobre os efeitos da corticoterapia sobre parâmetros hematológicos e bioquímicos nesses animais. Nesse contexto, objetivou-se avaliar os parâmetros hematológicos e bioquímicos das primeiras horas de vida de cabritos prematuros provenientes de cabras que utilizaram diferentes protocolos de dexametasona. Para tal, as cabras foram divididas em três grupos: grupo I, cabras que receberam 20 mg de dexametasona aos 139 dias de gestação; grupo II, 2 mg de dexametasona do 133° ao 136° dia de gestação, 4 mg do 137° ao 139° e 20 mg no 140° dia; grupo III, 16 mg de dexametasona a partir do 139° dia, com doses repetidas a cada 12 horas até a cirurgia eletiva; e grupo IV, cabras que receberam 4, 8, 16 e 20 mg de dexametasona no 137°, 138°, 139° e 140° dias de gestação, respectivamente. As amostras sanguíneas dos cabritos foram obtidas ao nascimento (T0h), 1 (T1h), 12 (T12h), 24 (T24h) e 48 horas (T48h) de vida para avaliação do hemograma e bioquímica sérica de ureia, creatinina, proteína total (PT) e gamaglutamiltransferase (GGT). Os teores de PT e atividade de GGT foram menores ao nascimento em todos os grupos, elevando-se após ingestão do colostro. Os valores de creatinina em todos os grupos experimentais não diferiram entre T0h e T1H, entretanto, diminuíram nos momentos subsequentes. Com exceção do grupo I, as concentrações de ureia foram maiores no T48h em comparação com o T1h. Os valores de hemácias, hemoglobina, hematócrito e volume corpuscular médio diminuíram ao longo do tempo, enquanto a concentração de hemoglobina corpuscular média aumentou ao longo do tempo. A contagem leucocitária total se comportou de maneira distinta nos diferentes grupos experimentais, demonstrado ser influenciada pelos teores de dexametasona principalmente em decorrência da alteração nas contagens de neutrófilos segmentados e linfócitos. Conclui-se que alterações significativas dos parâmetros hematológicos e bioquímicos ocorrem nas primeiras horas de vida de cabritos prematuros e o tratamento de cabras com dexametasona também pode afetar tais parâmetros de forma dependente da dose.

Postprandial lipemia causes oxidative stress in dogs.

Oxidative stress (OS) has been strongly associated with postprandial lipemia (PPL) in humans, and still requires further investigation in dogs. However, since lipemia interferes with spectrophotometric determinations such as those used to assess OS, the present study investigated the effect of PPL on OS parameters of healthy dogs. Twenty dogs had lipemic postprandial samples compared to the average of two non-lipemic moments. Subsequently, PPL was simulated in vitro using a commercial lipid emulsion and twelve pools of non-lipemic serum of these dogs were used to simulate the minimum, median and maximum concentrations of triglycerides obtained during the lipemic state. Serum OS parameters were assessed using the antioxidants uric acid, albumin and total bilirubin; total antioxidant capacity (TAC); total oxidant capacity (TOC); and lipid peroxidation. In vivo PPL caused an increase in albumin, TAC-CUPRAC, TAC-FRAP, uric acid (p < 0.0001), TOC (p = 0.0012) and total bilirubin (p = 0.0245); reduction of TAC-ABTS (p = 0.0008); and did not alter the lipid peroxidation (p = 0.8983). In vitro, levels of albumin increased at the three lipemic concentrations (p < 0.0001), uric acid increased in the median and maximum levels (p < 0.0001), and total bilirubin concentration increased only at the maximum lipemic level (p = 0.0012). All lipemic levels tested increased TAC-ABTS (p = 0.0011) and TAC-FRAP (p < 0.0001). TAC-CUPRAC (p = 0.5002), TOC (p = 0.5938) and lipid peroxidation (p = 0.4235) were not affected by in vitro lipemia. In conclusion, both the in vivo postprandial state and in vitro simulated lipemia affect oxidative stress markers in dogs depending on the oxidative stress marker, and thus the postprandial state and/or lipemic samples should be avoided.

Systemic oxidative stress in Suffolk and Santa Ines sheep experimentally infected with Haemonchus contortus.

The mechanisms responsible for the imbalance between oxidants and antioxidants in sheep infected with Haemonchus contortus are not well established. This study aimed to prove the hypothesis that oxidative stress occurring during infection by H. contortus varies according to breed, and that the parasite burden correlates with hypoalbuminaemia and anaemia. Thus, after deworming and confirming the absence of infection, two different sheep breeds, Suffolk (n = 15) and Santa Ines (n = 22), were orally inoculated with a single dose of 5,000 L3 of H. contortus. The egg counts per gram of faeces (EPG), packed cell volume (PCV) and concentrations of several plasma markers of oxidative stress (lipid peroxidation, albumin, uric acid, total bilirubin, total antioxidant capacity [TAC], total oxidant concentration [TOC] and the oxidative stress index [OSI]) were quantified before (control group) and during the experimental infection (28, 34 and 42 days post-inoculation). In both breeds, TOC increased at 28 days and TAC increased at 42 days. In Suffolk sheep, there was a positive correlation of EPG with oxidant components (28 days) and a negative correlation of EPG with PCV (42 days). In Santa Ines sheep, there was a positive correlation of EPG with bilirubin (r = 0.492; p = 0.020). H. contortus infection caused oxidative stress, which varied according to the breed. Parasite burden was not associated with hypoalbuminaemia, whereas there was a negative correlation with PCV. This research provides the first evidence that the antioxidant status contributes more to the resilience to H. contortus in Santa Ines sheep compared to Suffolk sheep.

Prediction of lymph node parasite load from clinical data in dogs with leishmaniasis: An application of radial basis artificial neural networks.

Quantification of Leishmania infantum load via real-time quantitative polymerase chain reaction (qPCR) in lymph node aspirates is an accurate tool for diagnostics, surveillance and therapeutics follow-up in dogs with leishmaniasis. However, qPCR requires infrastructure and technical training that is not always available commercially or in public services. Here, we used a machine learning technique, namely Radial Basis Artificial Neural Network, to assess whether parasite load could be learned from clinical data (serological test, biochemical markers and physical signs). By comparing 18 different combinations of input clinical data, we found that parasite load can be accurately predicted using a relatively small reference set of 35 naturally infected dogs and 20 controls. In the best case scenario (use of all clinical data), predictions presented no bias or inflation and an accuracy (i.e., correlation between true and predicted values) of 0.869, corresponding to an average error of ±38.2 parasites per unit of volume. We conclude that reasonable estimates of L. infantum load from lymph node aspirates can be obtained from clinical records when qPCR services are not available.

A TOXINA URÊMICA ÁCIDO GUANIDINICOACÉTICO INIBE O METABOLISMO OXIDATIVO DOS NEUTRÓFILOS DE CÃES

Abstract Among the uremic toxins proven to affect the neutrophil function in humans with chronic kidney disease (CKD), guanidine compounds stand out. To achieve a clearer understanding of the mechanisms that affect the immunity of uremic patients, the hypothesis that guanidine acetic acid (GAA) contributes to the inhibition of oxidative metabolism and an increase in neutrophil apoptosis in healthy dogs was investigated in vitro. To this end, neutrophils isolated from ten healthy dogs were incubated in pure RPMI 1640 (control) and enriched with 5 mg/L of GAA. Capillary flow cytometry was used to quantify superoxide production in neutrophils with the probe (hydroethidine), in the presence and absence of phorbol-12-myristate-13-acetate (PMA), in order to assess oxidative metabolism. Apoptotic indices were quantified using the Annexin V-PE system, with and without the inductive effect of camptothecin. Neutrophils isolated and incubated in a GAA-enriched medium produced smaller amounts of superoxide (p 0.001) when activated with PMA, however, this inhibition of oxidative metabolism occurred without significantly altering their viability or rate of apoptosis. Thus, the results show guanidine compounds contribute to immunosuppression in dogs with CKD.

Resumo Dentre as toxinas urêmicas que comprovadamente afetam a função neutrofílica na doença renal crônica (DRC) em humanos, destacam-se os compostos guanidínicos. A fim de melhor entender os mecanismos que afetam a imunidade de pacientes urêmicos, no presente estudo foi investigada in vitro a hipótese de que o composto guanidínico ácido guanidinicoacético (AGA) contribui para inibição do metabolismo oxidativo, aumentando a apoptose dos neutrófilos de cães saudáveis. Para tal, neutrófilos isolados de dez cães saudáveis foram incubados em meio de cultura RPMI 1640 puro (controle) e enriquecido com 5 mg/L de AGA. Utilizando-se citometria de fluxo capilar para a avaliação do metabolismo oxidativo, quantificou-se a produção de superóxido dos neutrófilos empregando-se a sonda hidroetidina, com e sem a presença do estímulo com acetato miristato de forbol (PMA). O índice apoptótico foi quantificado utilizando-se o sistema Anexina V-PE, com e sem o efeito indutor da camptotecina. Os neutrófilos isolados e incubados em meio enriquecido com AGA, quando ativados com PMA, produziram uma menor quantidade de superóxido (p 0,001), porém tal inibição do metabolismo oxidativo ocorreu sem alterar significativamente a viabilidade e a taxa de apoptose. Assim, os resultados evidenciam que os compostos guanidínicos podem contribuir para imunossupressão de cães com DRC.

A toxina urêmica ácido guanidinicoacético inibe o metabolismo oxidativo dos neutrófilos de cães / Uremic toxin guanidine acetic acid inhibits the oxidative metabolism of neutrophils in dogs

Among the uremic toxins proven to affect the neutrophil function in humans with chronic kidney disease(CKD), guanidine compounds stand out. To achieve a clearer understanding of the mechanisms thataffect the immunity of uremic patients, the hypothesis that guanidine acetic acid (GAA) contributesto the inhibition of oxidative metabolism and an increase in neutrophil apoptosis in healthy dogswas investigated in vitro. To this end, neutrophils isolated from ten healthy dogs were incubated inpure RPMI 1640 (control) and enriched with 5 mg/L of GAA. Capillary flow cytometry was usedto quantify superoxide production in neutrophils with the probe (hydroethidine), in the presenceand absence of phorbol-12-myristate-13-acetate (PMA), in order to assess oxidative metabolism.Apoptotic indices were quantified using the Annexin V-PE system, with and without the inductiveeffect of camptothecin. Neutrophils isolated and incubated in a GAA-enriched medium producedsmaller amounts of superoxide (p 0.001) when activated with PMA, however, this inhibition ofoxidative metabolism occurred without significantly altering their viability or rate of apoptosis. Thus, the results show guanidine compounds contribute to immunosuppression in dogs with CKD.

Dentre as toxinas urêmicas que comprovadamente afetam a função neutrofílica na doença renalcrônica (DRC) em humanos, destacam-se os compostos guanidínicos. A fim de melhor entenderos mecanismos que afetam a imunidade de pacientes urêmicos, no presente estudo foi investigadain vitro a hipótese de que o composto guanidínico ácido guanidinicoacético (AGA) contribui parainibição do metabolismo oxidativo, aumentando a apoptose dos neutrófilos de cães saudáveis. Paratal, neutrófilos isolados de dez cães saudáveis foram incubados em meio de cultura RPMI 1640puro (controle) e enriquecido com 5 mg/L de AGA. Utilizando-se citometria de fluxo capilar paraa avaliação do metabolismo oxidativo, quantificou-se a produção de superóxido dos neutrófilosempregando-se a sonda hidroetidina, com e sem a presença do estímulo com acetato miristato deforbol (PMA). O índice apoptótico foi quantificado utilizando-se o sistema Anexina V-PE, com e semo efeito indutor da camptotecina. Os neutrófilos isolados e incubados em meio enriquecido com AGA,quando ativados com PMA, produziram uma menor quantidade de superóxido (p 0,001), porém talinibição do metabolismo oxidativo ocorreu sem alterar significativamente a viabilidade e a taxa deapoptose. Assim, os resultados evidenciam que os compostos guanidínicos podem contribuir paraimunossupressão de cães com DRC.

A toxina urêmica ácido guanidinicoacético inibe o metabolismo oxidativo dos neutrófilos de cães / Uremic toxin guanidine acetic acid inhibits the oxidative metabolism of neutrophils in dogs

Among the uremic toxins proven to affect the neutrophil function in humans with chronic kidney disease(CKD), guanidine compounds stand out. To achieve a clearer understanding of the mechanisms thataffect the immunity of uremic patients, the hypothesis that guanidine acetic acid (GAA) contributesto the inhibition of oxidative metabolism and an increase in neutrophil apoptosis in healthy dogswas investigated in vitro. To this end, neutrophils isolated from ten healthy dogs were incubated inpure RPMI 1640 (control) and enriched with 5 mg/L of GAA. Capillary flow cytometry was usedto quantify superoxide production in neutrophils with the probe (hydroethidine), in the presenceand absence of phorbol-12-myristate-13-acetate (PMA), in order to assess oxidative metabolism.Apoptotic indices were quantified using the Annexin V-PE system, with and without the inductiveeffect of camptothecin. Neutrophils isolated and incubated in a GAA-enriched medium producedsmaller amounts of superoxide (p 0.001) when activated with PMA, however, this inhibition ofoxidative metabolism occurred without significantly altering their viability or rate of apoptosis. Thus, the results show guanidine compounds contribute to immunosuppression in dogs with CKD.(AU)

Dentre as toxinas urêmicas que comprovadamente afetam a função neutrofílica na doença renalcrônica (DRC) em humanos, destacam-se os compostos guanidínicos. A fim de melhor entenderos mecanismos que afetam a imunidade de pacientes urêmicos, no presente estudo foi investigadain vitro a hipótese de que o composto guanidínico ácido guanidinicoacético (AGA) contribui parainibição do metabolismo oxidativo, aumentando a apoptose dos neutrófilos de cães saudáveis. Paratal, neutrófilos isolados de dez cães saudáveis foram incubados em meio de cultura RPMI 1640puro (controle) e enriquecido com 5 mg/L de AGA. Utilizando-se citometria de fluxo capilar paraa avaliação do metabolismo oxidativo, quantificou-se a produção de superóxido dos neutrófilosempregando-se a sonda hidroetidina, com e sem a presença do estímulo com acetato miristato deforbol (PMA). O índice apoptótico foi quantificado utilizando-se o sistema Anexina V-PE, com e semo efeito indutor da camptotecina. Os neutrófilos isolados e incubados em meio enriquecido com AGA,quando ativados com PMA, produziram uma menor quantidade de superóxido (p 0,001), porém talinibição do metabolismo oxidativo ocorreu sem alterar significativamente a viabilidade e a taxa deapoptose. Assim, os resultados evidenciam que os compostos guanidínicos podem contribuir paraimunossupressão de cães com DRC.(AU)