Ischemia With Preconditioning in Wistar Rats Maintains Mitochondrial Respiration, Even With Mild Hepatocellular Disturbance.

INTRODUCTION: In hepatectomy or liver transplantation, preconditioning is a procedure indicated to protect the organ from ischemia-reperfusion injury (I-R). OBJECTIVE: Evaluate the effect of preconditioning after hepatic I-R in Wistar rats, through mitochondrial respiration, liver histology, and profile. METHOD: Twenty male Wistar rats, weighing on average 307.1 g, were anesthetized with sodium thiopental (25 mg/kg) intravenously and xylazine hydrochloride (30 mg/kg) intramuscularly. The animals were divided into 2 groups: the preconditioning group (PCG), which contained 10 animals, and the hepatic pedicle was isolated and submitted to clamping with microvascular clamp (10 minutes of ischemia and 10 minutes of reperfusion, followed by 30 minutes of ischemia and 30 minutes of reperfusion); and the simulated operation group (SOG), which contained 10 animals submitted to manipulation of the hepatic pedicle and observation for the same length of time, with blood collected for transaminase dosage measurements, and liver biopsy for evaluation of mitochondrial respiration and histologic liver analysis and after sacrificed under anesthesia. The project was approved by the Ethics Committee on Animal Experimentation CEEA/UNICAMP under protocol number 3905-1. RESULT: The PCG mitochondria showed the same respiration level as the SOG, when stimulated with the addition of adenosine diphosphate or carbonyl cyanide p-trifluoromethoxyphenylhydrazone. In the respiratory control ratio and resting of velocity of respiration the groups behaved in a similar way. The PCG presented high aspartate and alanine transaminases (P < .03) and about 60% of sinusoidal congestion and venous congestion in the histologic analysis when compared with SOG. CONCLUSION: We found that ischemia with preconditioning in Wistar rats can lead to mild histologic and biochemical dysfunction without leading to impairment of mitochondrial respiration.

Genetic parameters and selection of soybean lines based on selection indexes.

Defining selection criteria is important to obtain promising genotypes in a breeding program. The objective of this study was to estimate genetic parameters for agronomic traits and to perform soybean line selection using selection indices. The experiment was conducted at an experimental area located at Capim Branco farm, belonging to the Federal University of Uberlândia. A total of 37 soybean genotypes were evaluated in randomized complete block design with three replicates, in which twelve agronomic traits were evaluated. Analysis of variance, the Scott-Knott test at the 1 and 5% level of probability, and selection index analyses were performed. There was genetic variability for all agronomic traits, with medium to high levels of genotype determination coefficient. Twelve lines with a total cycle up to 110 days were observed and grouped with the cultivars MSOY 6101 and UFUS 7910. Three lines, UFUS FG 03, UFUS FG 20, and UFUS FG 31, were highlighted regarding grain yield with higher values than the national average of 3072 kg/ha. The direct selection enabled the highest trait individual gains. The Williams (1962) index and the Smith (1936) and Hazel (1943) index presented the highest selection gain for the grain yield character. The genotype-ideotype distance index and the index of the sum of ranks of Mulamba and Mock (1978) presented higher values of total selection gain. The lines UFUS FG 12, UFUS FG 14, UFUS FG 18, UFUS FG 25, and UFUS FG 31 were distinguished as superior genotypes by direct selection methods and selection indexes.

Genotype x environment interaction and stability of soybean cultivars for vegetative-stage characters.

In order to obtain the certificate of cultivar protection, it is necessary to prove its distinctiveness, homogeneity, and stability. Currently, there are 37 descriptors for differentiating soybeans cultivars. However, they are still not enough and, as a result, it is necessary to create, identify, and evaluate new descriptors. This study was aimed at evaluating the genotypic and environment interaction (GxE) and determining the stability of eight soybean cultivars for five vegetative-stage descriptors. The research was done in a greenhouse of the Soybean Breeding and Genetic Studies Program of Universidade Federal de Uberlândia. The treatments were composed of eight soybean cultivars, sown in two different growing seasons (January 25, 2014 and November 27, 2014). The experiments were carried out in randomized complete blocks with three replications and each experimental plot consisted of one pot with four soybean plants. The characters evaluated were: length of hypocotyl (LH), length of epicotyl (LE), length of unifoliolate leaf petiole (LUP), length of first trifoliate leaf petiole (LTLP), and rachis length of terminal leaflet of the first trifoliate leaf (RL). The data achieved from the trials were undergone genetic-statistical analyses by the GENES software. For all analyzed characters, the existence of genetic variability was observed emphasizing the vegetative-stage descriptors' utility to differentiate soybean cultivars. The occurrence of GxE interaction was detected for all characters assessed, mainly of complex nature, except by RL, which was of simple nature. The most stable cultivars for the vegetative-stage descriptors analysed were UFUS 7415 and UFUS Impacta.

Phenotypic and genotypic correlations between soybean agronomic traits and path analysis.

The goals of this research were to evaluate the phenotypic and genotypic correlations between agronomic traits, to perform path analysis, having as main character grain yield, and to identify indirect selection criteria for grain yield. The experiment was carried out in an experimental area located at Capim Branco farm, which belongs to Federal University of Uberlândia, during the growing season of 2015/2016.Twenty-four soybean genotypes were evaluated under randomized complete block design with three repetitions, of which agronomic traits and grain yield were measured. There was genetic variability for all traits at 5% probability level through the F-test. Thirty significant phenotypic correlations were also observed with values oscillating from 0.42 to 0.87, which indicated a high level of association between some evaluated traits. Additionally, we verified that phenotypic and genotypic correlations were essential of the same direction, being the genotypic ones of superior magnitudes. Plants with superior vegetative cycle had longer life cycles; this fact could be explained by the significant phenotypic correlations between the number of days to the blooming and number of days to maturity (0.76). Significantly positive phenotypic and genotypic correlations for the total number of pods per plant and grain yield per plant (0.84) were observed. Through the path analysis, the trait that contributed the most over grain yield was the number of pods with three seeds as it showed the highest direct effect on grain yield per plant, as well as a strong indirect effect on the total number of pods. Therefore, the phenotypic and genotypic correlations suggested high correlations between grain yield and number of branched nodes, the number of pods with two and three seeds, and the total number of pods. Also, the path analysis determined the number of pods with three seeds as having the highest favorable effect on grain yield, and thus, being useful for indirect selection toward productive soybean genotypes.

Biliary obstruction after short-time choledochal clamping in rats.

INTRODUCTION: Biliary complications after liver procedures can lead to morbidity and poor survival. AIM: The aim of this study was to evaluate the hepatic function after quick clamping of the common bile duct (BD) in Wistar rats. METHODS: Twelve male Wistar rats with a mean weight of 323.14 g were anesthetized with sodium thiopental intravenous (IV). The common BD Clamping Group (BDCG; n = 6) was submitted to an abdominal incision (2 cm); the BD was isolated, dissected, and underwent clamping for 10 minutes with a microvascular clamp. After this time, the clamp was removed and the incision closed. The Sham Operation Group (SOG; n = 6 rats), under normal conditions, were subjected only to anesthesia and laparotomy and later control tests. On the 28th day liver and choledoch biopsy and biochemical tests were performed on all animals: total bilirubin (TB), alkaline phosphatase (ALK-P), aminotransferases (aspartate aminotransferase [AST] and alanine aminotransferase [ALT]), and gamma-glutamyl transferase (GGT). After the tests all the rats were humanely killed while still under anesthesia. RESULTS: In this study 83% of the animals in the BDCG had large dilatation of the common BD with ductular proliferation, formation of septae, as well as multiple foci of parenchymal necrosis including micro-abscess formation. We also observed alterations in biochemical tests (P < .05). CONCLUSION: Our study demonstrated that BD clamping even for a short time was sufficient to generate important morphological alterations in the liver and BD, as confirmed by enzymatic and histological analysis. Therefore, this technique can be used as a model of biliary obstruction for future studies.

[Study of renal glucose release in rabbits submitted to total functional hepatectomy and norepinephrine infusion]. / Estudo da liberação renal de glicose em coelhos submetidos a hepatectomia total funcional e infusão de noradrenalina.

AIM: To study the possible endogenous sources of glucose in the absence of the liver (equivalent to the anhepatic period of liver transplantation). MATERIAL AND METHODS: A experimental model of total functional hepatectomy in anesthetized rabbits was developed. The aorta and the right renal vein were catheterised in order to collect blood samples to measure glucose contents. The animals were divided into two groups: group 1, 5 animals underwent only norepinephrine infusion; group 2, 15 animals underwent norepinephrine infusion and submitted to total functional hepatectomy. RESULTS: In group 2, before the hepatectomy, arterial glucose levels were higher than venous ones and after the liver removal, the venous levels became higher than the arterial ones. This pattern showed an inversion in the glycemic curves. In group 1 this pattern was not observed. CONCLUSION: The glycemic curves behavior observed in group 2 its not due to norepinephrine infusion, but represents renal glucose release after total functional hepatectomy.