Charge sparsity: an index to quantify cation effects on clay dispersion in soils

Few approaches have been developed to measure the isolated effect of exchangeable cations on clay dispersion in soils. In this study, the charge sparsity (CS) index was proposed using the ratio between the cations hydrated ionic radius and valence. The index capacity to measure cation effects on clay dispersion in soils was also evaluated. Three Ferralsols, sampled at different sites in Paraná State, Brazil, were homoionized with Ca2+, Mg2+, K+, or Na+ prior to evaluation of the clay dispersion degree. Published independent data for two soils and clays were also used. We tested the capacity of CS and II, the latter proposed by Marchuck and Rengasamy (2011), to predict clay dispersion in soils. The CS predicted the dispersion degree more accuratelly than the ionicity index did, in soils where Ca2+ and Mg2+ behaved similarly. The response of Paraná soils to CS varied with soil characteristics. Soils with a lower pH at the isoelectric point were more dispersible by cations with high CS (K+ and Na+). The CS was efficient to quantify the isolated effect of cations on the clay dispersion process in soils. Therefore, qualitative and quantitative studies can benefit from the CS as an index to understand the effect of cations on clay dispersion in soils.

Charge sparsity: an index to quantify cation effects on clay dispersion in soils

Few approaches have been developed to measure the isolated effect of exchangeable cations on clay dispersion in soils. In this study, the charge sparsity (CS) index was proposed using the ratio between the cations hydrated ionic radius and valence. The index capacity to measure cation effects on clay dispersion in soils was also evaluated. Three Ferralsols, sampled at different sites in Paraná State, Brazil, were homoionized with Ca2+, Mg2+, K+, or Na+ prior to evaluation of the clay dispersion degree. Published independent data for two soils and clays were also used. We tested the capacity of CS and II, the latter proposed by Marchuck and Rengasamy (2011), to predict clay dispersion in soils. The CS predicted the dispersion degree more accuratelly than the ionicity index did, in soils where Ca2+ and Mg2+ behaved similarly. The response of Paraná soils to CS varied with soil characteristics. Soils with a lower pH at the isoelectric point were more dispersible by cations with high CS (K+ and Na+). The CS was efficient to quantify the isolated effect of cations on the clay dispersion process in soils. Therefore, qualitative and quantitative studies can benefit from the CS as an index to understand the effect of cations on clay dispersion in soils.(AU)

Fluidoterapia nos pacientes em choque séptico: revisão de literatura / Fluid therapy on patients in septic shock: literature review

Sepse, definida pela Síndrome da Resposta Inflamatória Sistêmica (SRIS) secundária a um agente infeccioso, é uma afecção comum em cães e gatos e está relacionada a altos índices de morbidade e mortalidade nestas espécies. Sua patogenia é complexa e multifatorial, mas a instabilidade hemodinâmica tem sido apontada como fator relevante para o alto índice de óbito nos pacientes, pois gera hipóxia e subsequente disfunção de múltiplos órgãos. O tratamento é baseado na terapia guiada por metas e tem como objetivo restaurar o equilíbrio circulatório pela infusão de grandes quantidades de fluido, sendo que a escolha da fluidoterapia adequada é ainda muito controversa. Assim, esta revisão descreve a fisiopatogenia da sepse e compara resultados do uso de coloides e cristaloides apresentados nos periódicos consultados.

Defined by the Systemic Inflammatory Response Syndrome (SIRS), which is secondary to an infectious agent, sepsis is a common affection in dogs and cats, being related to high morbidity and mortality rates in these species. The pathogenesis is multifactorial and complex. Hemodynamic instability is being identified as a key factor for the high mortality rate, since it causes hypoxia and subsequent multiple organ dysfunction. The treatment consists of goal-oriented therapy and the primary objective is to restore the circulatory balance through the infusion of large amounts of fluid. However, choosing the adequate fluid therapy is still very controversial. Thus, the objective of this review is to describe the pathophysiology of sepsis and to compare the results of the use of the colloids and crystalloids presented in the scientific articles analyzed.

Fluidoterapia nos pacientes em choque séptico: revisão de literatura / Fluid therapy on patients in septic shock: literature review

Sepse, definida pela Síndrome da Resposta Inflamatória Sistêmica (SRIS) secundária a um agente infeccioso, é uma afecção comum em cães e gatos e está relacionada a altos índices de morbidade e mortalidade nestas espécies. Sua patogenia é complexa e multifatorial, mas a instabilidade hemodinâmica tem sido apontada como fator relevante para o alto índice de óbito nos pacientes, pois gera hipóxia e subsequente disfunção de múltiplos órgãos. O tratamento é baseado na terapia guiada por metas e tem como objetivo restaurar o equilíbrio circulatório pela infusão de grandes quantidades de fluido, sendo que a escolha da fluidoterapia adequada é ainda muito controversa. Assim, esta revisão descreve a fisiopatogenia da sepse e compara resultados do uso de coloides e cristaloides apresentados nos periódicos consultados.(AU)

Defined by the Systemic Inflammatory Response Syndrome (SIRS), which is secondary to an infectious agent, sepsis is a common affection in dogs and cats, being related to high morbidity and mortality rates in these species. The pathogenesis is multifactorial and complex. Hemodynamic instability is being identified as a key factor for the high mortality rate, since it causes hypoxia and subsequent multiple organ dysfunction. The treatment consists of goal-oriented therapy and the primary objective is to restore the circulatory balance through the infusion of large amounts of fluid. However, choosing the adequate fluid therapy is still very controversial. Thus, the objective of this review is to describe the pathophysiology of sepsis and to compare the results of the use of the colloids and crystalloids presented in the scientific articles analyzed.(AU)

Histopatologia de Colossoma macropomum expostos à prata coloidal

A prata é um elemento usado amplamente pelas suas propriedades antimicrobianas. O uso indiscriminado de antimicrobianos na produção piscícola é cada vez maior o que induz a resistência bacteriana e impactos negativos no meio ambiente. A procura de alternativas para o tratamento de bacterioses é necessária sendo preciso estudas todas as variáveis e efeitos que estes possam gerar no animal e ambiente. No presente ensaio foram estudadas as alterações teciduais induzidas no tambaqui (Colossoma macropomum) pela exposição aguda à prata coloidal.

Histopatologia de Colossoma macropomum expostos à prata coloidal

A prata é um elemento usado amplamente pelas suas propriedades antimicrobianas. O uso indiscriminado de antimicrobianos na produção piscícola é cada vez maior o que induz a resistência bacteriana e impactos negativos no meio ambiente. A procura de alternativas para o tratamento de bacterioses é necessária sendo preciso estudas todas as variáveis e efeitos que estes possam gerar no animal e ambiente. No presente ensaio foram estudadas as alterações teciduais induzidas no tambaqui (Colossoma macropomum) pela exposição aguda à prata coloidal.(AU)

Determinação da CL 50 aguda em Colossoma macropomum expostos à prata coloidal

A prata é um elemento que foi usado durante muitos anos e atualmente é amplamente usado pelas suas propriedades antimicrobianas. Nas últimas décadas, as nanopartículas de prata têm oferecido um campo muito amplo de pesquisa pelas suas extraordinárias atividades biológicas e propriedades físico-químicas como fonte de interesses para novas aplicações além do fato de não induzir resistência bacteriana. No presente estudo foi determinada a concentração letal 50 da prata coloidal em tambaqui (Colossoma macropomum) de forma aguda, 48 horas.(AU)

Determinação da CL 50 aguda em Colossoma macropomum expostos à prata coloidal

A prata é um elemento que foi usado durante muitos anos e atualmente é amplamente usado pelas suas propriedades antimicrobianas. Nas últimas décadas, as nanopartículas de prata têm oferecido um campo muito amplo de pesquisa pelas suas extraordinárias atividades biológicas e propriedades físico-químicas como fonte de interesses para novas aplicações além do fato de não induzir resistência bacteriana. No presente estudo foi determinada a concentração letal 50 da prata coloidal em tambaqui (Colossoma macropomum) de forma aguda, 48 horas.

Colloid osmotic pressure during and after surgical interventions in adult and geriatric dogs / Pressão coloidosmótica durante e depois de intervenção cirúrgica em cães adultos e geriátricos

The objective this study is to evaluate colloid osmotic pressure (COP) fluctuations in adult and senile dogs during surgical interventions. Thirty-six healthy dogs to surgical interventions, distributed in two groups, A and B, according to their age, and were all subjected to the same anesthetic protocol. Values of albumin, total plasmatic protein and COP were evaluated from samples collected before pre-anesthetic medication, fifteen minutes after pre-anesthetic medication, and shortly after the end of the intervention. Results were tested using t-test to compare among groups and ANOVA for repeated measures followed by Tukey's test to compare different moments within the same group. Statistical significance was set at p<0.05. In both groups, significant decreases were observed in colloid osmotic pressure, as well as albumin and total proteins (p<0.001). Despite slightly lower COP values for the group of adult animals, this difference was not significant as there was a high individual variation within groups. The results therefore indicate no difference in colloid osmotic pressure values or fluctuation patterns among adult and senile dogs (p=0.124). The observed results indicate that colloid osmotic pressure decreases significantly during surgical procedures, due to hypotension caused by the anesthetic drugs and to hemodilution caused by the fluid administration but there is no difference between groups. However, in both adult and senile dogs, these variables recover gradually after the animals awaken, through increased urine production and recovery of vascular tonus, indicating the successful reestablishment of homeostasis.(AU)

O objetivo deste estudo é avaliar as flutuações da pressão coloidosmótica (PCO) em cães adultos e idosos durante a intervenção cirúrgica. Foram utilizados 36 cães hígidos submetidos à intervenção cirúrgica, distribuídos em dois grupos de acordo com a idade e submetidos ao mesmo protocolo anestésico. Os valores de albumina, proteína plasmática total e PCO foram avaliados de amostras coletadas antes da medicação pré-anestésica, 15 minutos após e ao final do procedimento cirúrgico. Os dados obtidos foram analisados através do teste-t para comparação entre os grupos e ANOVA para medidas repetidas seguido do teste de Tukey para comparar diferentes momentos dentro do mesmo grupo. Foram considerados estastisticamente diferentes com p<0.05. Em ambos os grupos foram observados decréscimo dos valores da pressão coloidosmótica, como os valores de albumina e proteína total (p<0.001). Apesar de ligeiramente inferior, os valores de PCO para o grupo adulto não apresentaram diferença significativa. Os resultados indicam que não houve diferença nos valores da pressão oncótica ou padrão de flutuação entre adultos e idosos (p=0,124). Os resultados observados indicam significativo decréscimo da pressão coloidosmótica durante os procedimentos cirúrgicos devido à hipotensão causada pelos fármacos anestésicos e pela hemodiluição causada pela administração de fluídos, mas não houve diferença entre os grupos. Entretanto, tanto em cães adultos como idosos, essas variações retornaram gradualmente após a recuperação dos animals, através do aumento da produção de urina e da recuperação do tônus vascular, indicando restabelecimento da homeostase.(AU)

Colloid osmotic pressure during and after surgical interventions in adult and geriatric dogs / Pressão coloidosmótica durante e depois de intervenção cirúrgica em cães adultos e geriátricos

The objective this study is to evaluate colloid osmotic pressure (COP) fluctuations in adult and senile dogs during surgical interventions. Thirty-six healthy dogs to surgical interventions, distributed in two groups, A and B, according to their age, and were all subjected to the same anesthetic protocol. Values of albumin, total plasmatic protein and COP were evaluated from samples collected before pre-anesthetic medication, fifteen minutes after pre-anesthetic medication, and shortly after the end of the intervention. Results were tested using t-test to compare among groups and ANOVA for repeated measures followed by Tukey's test to compare different moments within the same group. Statistical significance was set at p<0.05. In both groups, significant decreases were observed in colloid osmotic pressure, as well as albumin and total proteins (p<0.001). Despite slightly lower COP values for the group of adult animals, this difference was not significant as there was a high individual variation within groups. The results therefore indicate no difference in colloid osmotic pressure values or fluctuation patterns among adult and senile dogs (p=0.124). The observed results indicate that colloid osmotic pressure decreases significantly during surgical procedures, due to hypotension caused by the anesthetic drugs and to hemodilution caused by the fluid administration but there is no difference between groups. However, in both adult and senile dogs, these variables recover gradually after the animals awaken, through increased urine production and recovery of vascular tonus, indicating the successful reestablishment of homeostasis.(AU)

O objetivo deste estudo é avaliar as flutuações da pressão coloidosmótica (PCO) em cães adultos e idosos durante a intervenção cirúrgica. Foram utilizados 36 cães hígidos submetidos à intervenção cirúrgica, distribuídos em dois grupos de acordo com a idade e submetidos ao mesmo protocolo anestésico. Os valores de albumina, proteína plasmática total e PCO foram avaliados de amostras coletadas antes da medicação pré-anestésica, 15 minutos após e ao final do procedimento cirúrgico. Os dados obtidos foram analisados através do teste-t para comparação entre os grupos e ANOVA para medidas repetidas seguido do teste de Tukey para comparar diferentes momentos dentro do mesmo grupo. Foram considerados estastisticamente diferentes com p<0.05. Em ambos os grupos foram observados decréscimo dos valores da pressão coloidosmótica, como os valores de albumina e proteína total (p<0.001). Apesar de ligeiramente inferior, os valores de PCO para o grupo adulto não apresentaram diferença significativa. Os resultados indicam que não houve diferença nos valores da pressão oncótica ou padrão de flutuação entre adultos e idosos (p=0,124). Os resultados observados indicam significativo decréscimo da pressão coloidosmótica durante os procedimentos cirúrgicos devido à hipotensão causada pelos fármacos anestésicos e pela hemodiluição causada pela administração de fluídos, mas não houve diferença entre os grupos. Entretanto, tanto em cães adultos como idosos, essas variações retornaram gradualmente após a recuperação dos animals, através do aumento da produção de urina e da recuperação do tônus vascular, indicando restabelecimento da homeostase.(AU)

The effect of humic acid substances on the thyroid function and structure in lead poisoning

Lead (Pb) is a heavy metal, which adversely affects thyroid gland function and structure. Due to its high molecular weight and abundant functional groups, humic acid substances (HAS) can form chelates with heavy metals. The experiment was conducted to evaluate the prophylactic effect of HAS on thyroid hormone levels and histopathological lesions of laying hens exposed to lead (Pb) poisoning. After a week of adaptation, 192 Lohmann White laying hens (25 weeks of age) were fed one of four diets: a basal diet (BD) or the BD with HAS (0.15%), with Pb (0.3 g/kg), or with both. Experimental groups were replicated in 12 cages, with four hens each. Pb poisoning did not alter triiodothyronine (FT3; 3.22 ± 0.20 ng/dL) or thyroxine (FT4; 0.71 ± 0.08 ng/dL) concentrations, but caused a 167% increase in thyroid stimulating hormone (TSH) concentration. HAS supplementation returned the high TSH levels of hens exposed to Pb poisoning to normal values. Degenerative changes in the epithelial cells of the thyroid gland of the hens exposed to Pb poisoning were evidenced. Connective tissue cells in the interfollicular area and total amount of colloids with partially atrophic follicles were observed. These histopathological findings were less severe when HAS was added to the diet. In conclusion, HAS alleviates the effects of Pb poisoning on thyroid gland function and structure, possibly preventing its internalization by the tissue by forming chelates and exerting anti-inflammatory effects.

The effect of humic acid substances on the thyroid function and structure in lead poisoning

Lead (Pb) is a heavy metal, which adversely affects thyroid gland function and structure. Due to its high molecular weight and abundant functional groups, humic acid substances (HAS) can form chelates with heavy metals. The experiment was conducted to evaluate the prophylactic effect of HAS on thyroid hormone levels and histopathological lesions of laying hens exposed to lead (Pb) poisoning. After a week of adaptation, 192 Lohmann White laying hens (25 weeks of age) were fed one of four diets: a basal diet (BD) or the BD with HAS (0.15%), with Pb (0.3 g/kg), or with both. Experimental groups were replicated in 12 cages, with four hens each. Pb poisoning did not alter triiodothyronine (FT3; 3.22 ± 0.20 ng/dL) or thyroxine (FT4; 0.71 ± 0.08 ng/dL) concentrations, but caused a 167% increase in thyroid stimulating hormone (TSH) concentration. HAS supplementation returned the high TSH levels of hens exposed to Pb poisoning to normal values. Degenerative changes in the epithelial cells of the thyroid gland of the hens exposed to Pb poisoning were evidenced. Connective tissue cells in the interfollicular area and total amount of colloids with partially atrophic follicles were observed. These histopathological findings were less severe when HAS was added to the diet. In conclusion, HAS alleviates the effects of Pb poisoning on thyroid gland function and structure, possibly preventing its internalization by the tissue by forming chelates and exerting anti-inflammatory effects.(AU)

Medical and surgical management of a large thermal burn in a dog

Background: Thermal wounds are relatively uncommon in veterinary practice and most of them are the result of accidental burns. Patients with severe burns are among the most challenging cases presented to veterinarians, because severe burn injury leads to significant hemodynamic instability, massive fluid shifts, and hypovolemia requiring prompt and aggressive therapy. Because severe burn injury in small animals has been poorly described in the veterinary literature, this case study describes the presentation, complications, medical and surgical treatment of a female dog with an accidental severe burn wound caused by a thermal mattress during an elective surgery. Case: A 6-month-old 9.6 kg female crossbred was referred with 20% total body surface area burned by a thermal mattress during an ovariohysterectomy procedure two days before. The dog presented a severe burn and systemic complications as anemia, leukocytosis, total protein at the lower limit and hyperlactatemia, which were managed with intensive medical care, including administration of crystalloid fluids, colloids, antibiotics, analgesics and enteral nutrition. The large wound was treated with debridement and the use of different kind of dressing to obtain a healthy granulation tissue. As a large portion of the trunk was lost, it was not possible to use axial pattern flaps, so skin-stretching devices and multiple surgic...(AU)

Medical and surgical management of a large thermal burn in a dog

Background: Thermal wounds are relatively uncommon in veterinary practice and most of them are the result of accidental burns. Patients with severe burns are among the most challenging cases presented to veterinarians, because severe burn injury leads to significant hemodynamic instability, massive fluid shifts, and hypovolemia requiring prompt and aggressive therapy. Because severe burn injury in small animals has been poorly described in the veterinary literature, this case study describes the presentation, complications, medical and surgical treatment of a female dog with an accidental severe burn wound caused by a thermal mattress during an elective surgery. Case: A 6-month-old 9.6 kg female crossbred was referred with 20% total body surface area burned by a thermal mattress during an ovariohysterectomy procedure two days before. The dog presented a severe burn and systemic complications as anemia, leukocytosis, total protein at the lower limit and hyperlactatemia, which were managed with intensive medical care, including administration of crystalloid fluids, colloids, antibiotics, analgesics and enteral nutrition. The large wound was treated with debridement and the use of different kind of dressing to obtain a healthy granulation tissue. As a large portion of the trunk was lost, it was not possible to use axial pattern flaps, so skin-stretching devices and multiple surgic...

The effect of 6% Hydroxyethyl starch vs. Ringer's lactate on acute kidney injury after renal ischemia in rats

PURPOSE: To compare fluid replacement therapy with Hydroxyethyl starch 6% (HES) versus Ringer's lactate (RL) in a rodent model of non-septic renal ischemia. METHODS: Forty male Wistar rats were randomized to receive HES 2 ml.kg-1.hr-1or RL 5 ml. kg-1.hr-1 that underwent 30 minutes of renal ischemia followed by reperfusion. Twelve hours after kidney ischemia, the kidneys were evaluated for histological changes. Serum NGAL levels were obtained at different times of the experimental protocol. RESULTS: Rodents in the HES group had a median (IQR) grade of renal injury 3 (3 to 5) compared to 2 (2 to 4) in the RL group (p=0.03). NGAL levels were not associated with the severity of kidney injury. CONCLUSION: Hydroxyethyl starch administration caused more kidney injury than Ringer's lactate in a non-infectious model of renal hypoperfusion.(AU)

Hipotensão arterial em cães e gatos – revisão / Arterial hypotension in dogs and cats - a review / Hipotensión arterial en perros y gatos - revisión

A hipotensão arterial é intercorrência frequente na rotina clínica e cirúrgica de pequenos animais, provocando graves consequências, como injúria renal aguda ou mesmo disfunção de múltiplos órgãos. Entender a fisiopatologia e conhecer as opções diagnósticas e terapêuticas dessa intercorrência são condições fundamentais para uma correta abordagem nesses casos. O objetivo deste estudo foi revisar a fisiopatologia da hipotensão arterial, mas principalmente descrever os principais métodos de diagnóstico e as recentes diretrizes de seu tratamento. A atual terapia guiada por metas direciona o profissional para o entendimento da necessidade de uma ação terapêutica precoce a partir do diagnóstico da hipotensão. Dessa forma, por meio de um rápido restabelecimento da pressão arterial, espera-se reduzir ou mesmo prevenir sequelas dessa síndrome clínica potencialmente fatal.

Hypotension is an usual event in small animals clinics, which can impact severely the clinical outcome of patients by causing acute kidney injury or multiple organ failure. It is fundamental to understand the physiopathology of this condition and to know the main diagnosis and therapeutic options to deal correctly with such cases. Therefore, the aim of this study was to briefly review the physiopathology of hypotension and to describe the main diagnostic methods, as well as the most recent treatment guidelines. The current goal-based therapy helps the professional to understand the need for an early therapeutic action as soon hypotension is diagnosed. Thus, one expects to decrease or even prevent major sequelae through a rapid return to normal blood pressure in this potentially fatal clinical syndrome.

La hipotensión es una complicación frecuente en la clínica y cirugía de pequeños animales que tiene consecuencias graves como la insuficiencia renal aguda o la falia de múltiples órganos. La comprensión de la fisiopatología y el reconocimiento de las opciones diagnósticas y terapêuticas de esta complicación son fundamentales para el correcto manejo de estos casos. EI objetivo de este trabajo fue revisar la literatura relacionada con la fisiopatología de la hipotensión arterial, describiendo, principalmente, los métodos más importantes para su diagnóstico, y las directrices recientes en cuanto al tratamiento. La terapêutica actual a través de metas guía al profesional en la comprensión de la necesidad de una acción terapêutica precoz a partir dei diagnóstico de la hipotensión. De esa forma, a través de uma recuperación rápida de la presión arterial, se espera reducir o prevenir las posibles secuelas de este síndrome clínico potencialmente fatal.

Hipotensão arterial em cães e gatos revisão / Arterial hypotension in dogs and cats - a review / Hipotensión arterial en perros y gatos - revisión

A hipotensão arterial é intercorrência frequente na rotina clínica e cirúrgica de pequenos animais, provocando graves consequências, como injúria renal aguda ou mesmo disfunção de múltiplos órgãos. Entender a fisiopatologia e conhecer as opções diagnósticas e terapêuticas dessa intercorrência são condições fundamentais para uma correta abordagem nesses casos. O objetivo deste estudo foi revisar a fisiopatologia da hipotensão arterial, mas principalmente descrever os principais métodos de diagnóstico e as recentes diretrizes de seu tratamento. A atual terapia guiada por metas direciona o profissional para o entendimento da necessidade de uma ação terapêutica precoce a partir do diagnóstico da hipotensão. Dessa forma, por meio de um rápido restabelecimento da pressão arterial, espera-se reduzir ou mesmo prevenir sequelas dessa síndrome clínica potencialmente fatal.(AU)

Hypotension is an usual event in small animals clinics, which can impact severely the clinical outcome of patients by causing acute kidney injury or multiple organ failure. It is fundamental to understand the physiopathology of this condition and to know the main diagnosis and therapeutic options to deal correctly with such cases. Therefore, the aim of this study was to briefly review the physiopathology of hypotension and to describe the main diagnostic methods, as well as the most recent treatment guidelines. The current goal-based therapy helps the professional to understand the need for an early therapeutic action as soon hypotension is diagnosed. Thus, one expects to decrease or even prevent major sequelae through a rapid return to normal blood pressure in this potentially fatal clinical syndrome.(AU)

La hipotensión es una complicación frecuente en la clínica y cirugía de pequeños animales que tiene consecuencias graves como la insuficiencia renal aguda o la falia de múltiples órganos. La comprensión de la fisiopatología y el reconocimiento de las opciones diagnósticas y terapêuticas de esta complicación son fundamentales para el correcto manejo de estos casos. EI objetivo de este trabajo fue revisar la literatura relacionada con la fisiopatología de la hipotensión arterial, describiendo, principalmente, los métodos más importantes para su diagnóstico, y las directrices recientes en cuanto al tratamiento. La terapêutica actual a través de metas guía al profesional en la comprensión de la necesidad de una acción terapêutica precoz a partir dei diagnóstico de la hipotensión. De esa forma, a través de uma recuperación rápida de la presión arterial, se espera reducir o prevenir las posibles secuelas de este síndrome clínico potencialmente fatal.(AU)

Long-term following-up of viability of spleen autotransplants in the Beagle canine model / Avaliação em longo prazo da viabilidade do autotransplante de baço em cães Beagle

PURPOSE: To examine the possible late complications of splenectomy or spleen autotransplantation in large laboratory animal model, in which we need non-invasive or minimal-invasive methods for long-term monitoring of the experimental animals. METHODS: Experimental groups of beagle dogs were: non-operated control, sham-operated control, splenectomy, spleen autotransplantation with 5 or 10 spleen-chips taken into the greater omentum (Furka's technique). Prior to operations, on the 1st postoperative week, monthly till the 6th as well as in the 9th and 12th month, hemorheological examinations were performed. In postoperative 12th month colloid scintigraphy and diagnostic laparoscopy were carried out. At the end of the investigation comparative morphological examinations were performed, too. RESULTS: From the 4th-5th postoperative month filtration function of spleen-autotransplants showed particular restoration compared to splenectomy group. However, the functional results did not reach the values of the control or sham-operated groups. Sham-operated control's scintigraphy nicely showed activity in the spleen. In spleen autotransplantation-groups scintigraphy indicated well the activity of spleen-chips. During diagnostic laparoscopy spleen-chips with their blood supply were found. Histologically, the structure of spleen­autotransplants was similar to normal splenic tissue. CONCLUSIONS: The autotransplants are regenerated, their functions have been partly restored, and thus spleen autotransplantation may prevent the possible complications of splenectomy. These parameters and the presented investigative protocol are suitable for long-term following-up of viability of the spleen-autotransplants.(AU)

OBJETIVO: Examinar as possíveis complicações tardias da esplenectomia ou do autotransplante de baço em modelo animal de grande porte, no qual faz-se necessário o uso de métodos não invasivos ou minimamente invasivos para monitorizar os animais de experimentação. MÉTODOS: Grupos experimentais de cães beagle foram: não-operados controle, sham-operados controle, esplenectomia, autotransplante de baço com 5 ou 10 fatias de baço colocados no grande omento (técnica de Furka). Antes das operações, na 1ª semana de pós­operatório, mensalmente até 6o.assim como no 9º. e 12º. mês, foram realizados exames hemorreológicos. No 12º. mês de pós-operatório, cintilografia colóide e laparoscopia diagnóstica foram realizadas. Ao final do experimento, exames morfológicos comparativos foram realizados também. RESULTADOS: A partir do 4º-5º mês pós-operatório, a função de filtração dos baços autotransplantados mostraram particular restauração comparados ao grupo esplenectomia. Entretanto, os resultados funcionais não alcançaram os valores dos grupos controle ou sham-operados. A cintilografia dos controles sham-operados mostraram atividade no baço. Nos grupos de autotransplante, a cintilografia indicou bem a atividade das fatias de baço. Durante a laparoscopia diagnóstica, as fatias de baço com seu suprimento sanguíneo foram encontrados. Histologicamente, a estrutura dos autotransplantes de baço foi similar ao tecido normal de baço. CONCLUSÕES: Os autotransplantes são regenerados, suas funções foram parcialmente restauradas, e então ao autotransplantate esplênico pode prevenir as possíveis complicações da esplenectomia. Estes parâmetros e o protocolo experimental são adequados para o seguimento em longo prazo da viabilidade de autotransplantes esplênicos.(AU)

Protective perioperative strategy using a third generation hydroxyethyl starch during surgery in a murine model of liver reperfusion injury / Estratégia protetora perioperatória usando um hidroxietilamido de terceira geração para expansão volêmica durante a cirurgia em modelo murino de lesão de reperfusão hepática

PURPOSE: To investigate whether a third generation colloid, hydroxyethyl starch (HES 130/0.4), used for perioperative fluid therapy, protects the rat liver against the late-phase response of ischemia/reperfusion injury (IRI) and if inhibition of neutrophil hepatic infiltration plays a part in this mechanism. METHODS: Wistar rats were used (8 in each group). Three groups had IRI induced by lobar vascular occlusion (60 minutes) and reperfusion (24 hours) and received HES (13 mL/kg iv), 7.5 percent saline (HS) (13 mL/kg iv) or no fluid. Three other groups were sham-operated and received the same fluid as the test groups. After 24 hours of reperfusion, blood was drawn for alanine aminotransferase (ALT) quantification and ischemic liver samples were taken for histological study (hematoxylin and eosin and chloroacetate staining of neutrophils). RESULTS: HES treatment attenuated the elevation in serum ALT (P=0.001) and reduced the extent of hepatocellular necrosis (P<0.01) compared with the IRI controls. HES-mediated cytoprotection was associated with a decrease of infiltration of neutrophils in the necrotic areas (P<0.05) compared with the untreated IRI rats, but not with the volume control IRI rats (P>0.05). CONCLUSION: Hydroxyethyl starch suppresses inflammatory response and ameliorates the late-phase response of hepatic ischemia/reperfusion injury.(AU)

OBJETIVO: Investigar se um colóide de terceira geração (HES 130/0.4), utilizado para fluidoterapia perioperatória, protege o fígado de rato contra a resposta da fase tardia de isquemia/reperfusão e se a inibição da infiltração hepática de neutrófilos desempenha um papel neste mecanismo. MÉTODOS: Foram utilizados ratos Wistar (8 em cada grupo). Três grupos tiveram lesão de isquemia/reperfusão (IRI) induzida por oclusão vascular lobar (60 minutos) e reperfusão (24 horas) e receberam HES (13 ml / kg iv), soro fisiológico a 7,5 por cento (HS) (13 ml / kg iv) ou nenhum fluido. Três outros grupos foram sham-operados e receberam o mesmo tipo de fluido dos grupos de teste. Após 24 horas de reperfusão, o sangue foi retirado para quantificação da alanina aminotransferase (ALT) e amostras de fígado isquêmico foram retiradas para estudo histológico (hematoxilina e eosina e coloração cloroacetato para neutrófilos). RESULTADOS: O tratamento com HES atenuou a elevação da ALT sérica (P = 0,001) e reduziu a extensão da necrose hepatocelular (P<0,01) em comparação com os controles da IRI. A citoproteção mediada por HES foi associada a uma diminuição da infiltração de neutrófilos nas áreas de necrose (P<0,05) em comparação com os ratos não tratados IRI, mas não com os ratos controlo IRI (P> 0,05). CONCLUSÃO: HES suprime a resposta inflamatória e melhora a resposta na fase tardia da isquemia/reperfusão hepática.(AU)

Efeitos cardiovasculares da anestesia dissociativa na reposição volêmica com colóide e solução hipertônica em cães: avaliação biotelemétrica / Cardiovascular effects of dissociative anesthesia in the volemic expansion with colloid and hypertonic solution in dogs: biotelemetric evaluation

Avaliaram-se os efeitos cardiovasculares por um período de 24 horas, após a administração de solução salina hipertônica (NaCl) 7,5 por cento ou em associação ao hidroxietilamido 130/0,4 (HES), em cães com hipovolemia induzida e tratados com cetamina levógira ou racêmica. Após a indução da hipovolemia, administrou-se NaCl 7,5 por cento (4mL/kg) no grupo hipertônica levógira (GHL) e no grupo hipertônica racêmica (GHR) ou HES 130/0,4 na mesma proporção de sangue retirado, associado a NaCl 7,5 por cento (4mL/kg) no grupo hipertônica colóide levógira (GHCL) e no grupo hipertônica colóide racêmica (GHCR). Após 30 minutos, administrou-se por via intravenosa, cetamina levógira (CL; 5mg/kg) no GHL e GHCL ou cetamina racêmica (CR; 10mg/kg) no GHR e GHCR. A frequência cardíaca (FC) e a pressão arterial sistólica (PAS) foram menores após a hipovolemia e após a CR. A pressão arterial média (PAM) e a pressão arterial diastólica (PAD) foram menores após a hipovolemia e após a administração de CL e CR. Não foram observadas diferenças significativas entre os grupos em relação à FC, PAS, PAM e PAD durante o período de mensuração por biotelemetria desde T210 até T1440. A administração de HES associado ao NaCl 7,5 por cento propiciou restabelecimento imediato da PAM, a administração de NaCl 7,5 por cento não restaurou a PAM em pacientes hipovolêmicos, a administração de CR ou CL produziu efeitos semelhantes e todos os tratamentos mantiveram estáveis as pressões arteriais e a FC por um período de até 24 horas.(AU)

The cardiovascular effects were evaluated for a 24-hour period, after the administration of hypertonic solution (NaCl 7.5 percent) or in association with hidroxyethyl starch 130/0.4 (HES) in dogs under induced experimental hypovolemia and treated with racemic ketamine (RK) or S(+) ketamine (SK). After the hypovolemia induction, administration of NaCl 7.5 percent (4mL.kg-1) was performed in two groups named hypertonic S(+) (HSG) and hypertonic racemic (HRG), or NaCl 7.5 percent (4mL.kg-1) in association with HES, in the same ratio of removed blood, in two groups named hypertonic colloid S(+) (HCSG) and hypertonic colloid racemic (HCRG). After 30 minutes, SK (5mg.kg-1) was administered by intravenous injection in HSG and HCSG groups, or RK (10mg.kg-1) in HRG and HCRG groups. The heart rate (HR) and systolic arterial pressure (SAP) were lower after hypovolemia and RK. Mean (MAP) and diastolic arterial pressure (DAP) were reduced after hypovolemia and either SK or RK administration. Significant differences were not observed among the groups to HR, SAP, MAP, and DAP during the biotelemetry mensuration period, from T210 to T1440. HES associated with NaCl 7.5 percent administration propitiated immediate re-establishment of MAP. NaCl 7.5 percent administration did not restore MAP in hypovolemic patients. Either RK or SK administrations produced similar effects and all of the treatments maintained stable blood pressure and heart rate for a 24-hour period.(AU)