Paraoxonase 1 low activity and SYNTAX score may predict postoperative complications after coronary artery surgery.

OBJECTIVE: Coronary artery bypass grafting (CABG) seems to present a powerful trigger of oxidative stress (OS) and acute inflammatory response. This study aimed to estimate the effects of off-pump coronary artery bypass (OPCAB) grafting on the OS that is commonly observed in patients undergoing operation under cardiopulmonary bypass (CPB). Additionally, we aimed to examine the relationship between and paraoxonase 1 (PON1) activity and the degree of stenosis, severity and complexity of the atherosclerotic lesions, estimated by SYNTAX score (SS). PATIENTS AND METHODS: Study group of 107 patients scheduled for CABG were divided into CPB and OPCAB group. Blood samples for OS markers measurement were collected at six-time intervals: before skin incision (t1), immediately after surgery (t2), 6h (t3), 24h (t4), 48h (t5) and 96h after cessation of the operation and surgical trauma (t6). SS was calculated. RESULTS: A significant decrease in lipid hydroperoxides (LOOH) and advanced oxidation protein products (AOPP) levels after both types of surgeries were observed, whereas PON1 reduction was observed higher in the CPB than in the OPCAB group. A significant inverse correlation between SS values and PON1 activity, preoperatively and during the early postoperative hours after surgery [in t2, t3 time intervals (p<0.05 for all)] was found. ROC analysis showed that for CPB patients, Model with all OS parameters showed excellent accuracy (AUC=0.957, p<0.001) for prediction postoperative complications. CONCLUSIONS: Decrease in PON1 activity during the early post-operative phases was related to higher SS. This relationship was more convincing in CPB, compared with OPCAB patients. Moreover, integrated models of OS status parameters have the capability to predict the development of postoperative complications.

A comparison of BoviPure and Percoll on bull sperm separation protocols for IVF.

In the present study, we have examined the effect of density gradient preparations BoviPure and Percoll on bull sperm separation and the in vitro fertilization (IVF) and culture (IVC) results. Frozen/thawed semen from five simmental bulls were pooled. Sperm quality parameters such as sperm motility, concentration, membrane activity (HOS assay), membrane integrity (SYBR-14/PI assay) and acrosomal status (EthD-1/FITC-PSA assay) were evaluated before and after sperm processing for IVF using BoviPure and Percoll density gradient separations. The results of the evaluated parameters before sperm processing were: motility 50%, concentration 82.33x10(6)spz/mL, membrane activity 39.05%, membrane integrity 42.97% and the acrosomal status 46.90% of the live spermatozoa with intact acrosomes. After sperm processing with BoviPure and Percoll the motility was 66.67 and 64.17%, the concentration was 25.50x10(6) and 27.67x10(6)spz/mL, the membrane activity was 53.78 and 56.58%, the membrane integrity was 70.85 and 68.76% of and the acrosomal status was 74.16 and 67.46% of the live spermatozoa with intact acrosomes, respectively. Percentages were referred to the total number of spermatozoa. There were significant differences (P<0.05) between the evaluated parameters before and after sperm processing for both separation protocols. We found no significant differences (P>0.05) regarding sperm evaluation parameters between the protocols. A total of 492 oocytes were matured and fertilized in vitro and cultured in SOFaaBSA in six replicates. The cleavage (D2) and blastocysts (D7) rate were significantly higher (P<0.05) for the BoviPure group compared to the Percoll group: 75.80 and 28.21%; 61.58 and 20.83%, respectively. However, the number of hatched blastocysts (D10) did not differ significantly between sperm separation protocols (P>0.05). Our results indicate that both protocols gave suitable sperm for IVF. This finding and the similarity between those two density gradient preparations suggests that BoviPure is a good alternative for sperm separation in bovine IVF.

The value of urine citrate/calcium ratio in the estimation of risk of urolithiasis.

The urine saturation is considered as the better parameter for the estimation of risk of urolithiasis than any single urinary constituent. However, the determination of urine saturation is unsuitable for routine clinical practice. To evaluate a simpler and cheaper test than urine saturation for distinguishing stone formers from healthy individuals, urinary citrate/calcium ratio was determined in 30 children with urolithiasis, 36 children with isolated hematuria, and 15 healthy control children. The ratio was significantly lower in urolithiasis group comparing to controls, and significantly higher in hematuria than in urolithiasis group. The cut-off points between normal children and children with urolithiasis, accuracy, specificity and sensitivity were determined and compared with those of the urine saturation calculated with the computer program EQUIL 2. The data mining Weka software was used for the determination of the cut-off points. Children with urolithiasis had citrate/calcium ratio below 1.38 and urine saturation above 5.285. The citrate/calcium ratio showed in comparison to urine saturation similar high accuracy (91.11 vs. 88.89%), somewhat lesser specificity (73.33% vs. 93.33%) and much better sensitivity (100% vs. 86.89%) in discrimination of stone formers from normal children. The advantage in comparison to urine saturation is that it can be easily performed in clinical practice.

S. cerevisiae has three pathways for DNA interstrand crosslink repair.

Yeast mutants, snm1 (pso2-1), rev3 (pso1-1), and rad51, which display significant sensitivity to interstrand crosslinks (ICLs) have low relative sensitivity to other DNA damaging agents. SNM1, REV3, and RAD51 were disrupted in the same haploid strain, singly and in combination. The double mutants, snm1 Delta rev3 Delta, snm1 Delta rad51 Delta and rev3 Delta rad51 Delta were all more sensitive to ICLs than any of the single mutants, indicating that they are in separate epistasis groups for survival. A triple mutant displayed greater sensitivity to ICLs than any of the double mutants, with one ICL per genome being lethal. Therefore, Saccharomyces cerevisiae appears to have three separate ICL repair pathways, but no more. S-phase delay was not observed after ICL damage introduced by cisplatin (CDDP) or 8-methoxypsoralen (8-MOP) during the G1-phase, in any of the above mutants, or in an isogenic rad14 Delta mutant deficient in nucleotide excision repair. However, the psoralen analog angelicin (monoadduct damage) induced a significant S-phase delay in the rad14 Delta mutant. Thus, normal S-phase in the presence of ICLs does not seem to be due to rapid excision repair. The results also indicate that monoadduct formation by CDDP or 8-MOP at the doses used is not sufficient to delay S-phase in the rad14 Delta mutant. While the sensitivity of a rev3 Delta mutant indicates Pol zeta is needed for optimal ICL repair, isogenic cells deficient in Pol eta (rad30 Delta cells) were not significantly more sensitive to ICL agents than wild-type cells, and have no S-phase delay.

Cryopreservation of ovine embryos: slow freezing and vitrification.

Different methods for the cryopreservation of ovine embryos were evaluated in vitro (survival upon culture in vitro) and in vivo (pregnancy and lambing rates after transfer in field conditions). In the first 2 experiments, slow freezing conditions were evaluated. When glycerol and ethylene glycol were compared, no differences in the overall pregnancy rate were found (40.2 vs 51.3%), but better results were obtained with ethylene glycol than with glycerol in morulae (29.7 vs 59.4%, P < 0.05). In the second experiment, 2 methods of removing ethylene glycol were compared: a 1-step procedure using 0.5-M sucrose and a 3-step process for decreasing ethylene glycol concentration. There were no differences in the overall pregnancy rate (48.0 vs 48.0%) between the 2 methods. The last series of experiments were designed to compare 2 vitrification solutions: propylene glycol--glycerol (PG) and ethylene glycol--Ficoll 70--sucrose (EFS). There were no differences between the 2 vitrification solutions, based on the overall pregnancy rate (28.1 vs 40.0%). The vitrification technique and specially with EFS solution has resulted in good pregnancy rates. The EFS solution was particularly efficacious with morulae (55.5% pregnancy). These results demonstrate that vitrification with EFS can be used successfully for the cryopreservation of ovine embryos.

Effect of glucose on embryo quality and post-thaw viability of in-vitro-produced bovine embryos.

The present study was carried out to evaluate the effect of glucose absence during the first 24 h of culture on blastocyst quality and survival after freezing and thawing. In Experiment 1, IVM/TVF bovine zygotes from a slaughterhouse were cultured for 24 h in SOFm, either in the absence or in the presence of 1.5 mM glucose and then further cultured for 7 d in SOFm with 1.5 mM glucose. Absence of glucose during the first 24 h of culture increased (P < 0.001) the percentage of embryos that developed to the morula and blastocyst stages. In Experiment 2, presumptive zygotes were incubated for 24 h in the absence of glucose and were then cultured for 7 d in the presence of 1.5, 3 or 5 mM glucose. There were no differences in the percentages of embryos developing to morula or blastocyst stages at 1.5 or 3 mM glucose, whereas the 5 mM concentration appeared to be detrimental (P < 0.001). Blastocysts from Experiments 1 and 2 were assessed for freezing resistance by means of the ability of frozen-thawed embryos to re-expand their blastocoelic cavity and hatch after culture for 72 h in vitro. For Grade 1 and 2 blastocysts, the post-freezing survival rate was unaffected when glucose was omitted during the first 24 h of culture, provided that the glucose was subsequently maintained between 1.5 and 3 mM. At 5 mM glucose, blastocoelic re-expansion was inhibited (P < 0.03). Addition of 1.5 or 3 mM glucose to the culture medium following 24 h of culture without glucose did not affect embryo cell number, whereas 5 mM significantly decreased it (P < 0.01). These results indicate that the first 24 h of culture without glucose do not affect embryo quality or post-thaw viability, but an increase in blastocyst yield was observed. After 24 h of culture addition of glucose in the range 1.5 to 3 mM was beneficial, while as higher concentrations decreased the efficacy of this in vitro production technique.

Stimulation of glutathione synthesis of in vitro matured bovine oocytes and its effect on embryo development and freezability.

Glutathione (GSH) has been shown to play an important role in embryo development. In a previous study, we demonstrated that cysteamine supplementation of in vitro maturation (IVM) medium increased the intracellular GSH content in bovine oocytes and improved subsequent embryo development to the blastocyst stage. The present study was carried out to evaluate the effect of inhibition by buthionine sulfoximide (BSO) of GSH synthesis during IVM in the presence of cysteamine, on subsequent embryo development, and the effect of cysteamine during IVM on the survival of blastocysts following freezing. The effect of beta-mercaptoethanol and cysteine added to the maturation medium on GSH levels in bovine oocytes, as well as the effect of these compounds on de novo GSH synthesis by oocytes during in vitro maturation, was also studied. The inhibitory effect of BSO during in vitro maturation on GSH synthesis was also evaluated. Evidence was found confirming that GSH synthesis occurs intracellularly during IVM of oocytes and is stimulated by cysteamine, beta-mercaptoethanol and cysteine. Moreover, the present results suggest that the increase in the rate of embryo development exerted by cysteamine, when present during IVM, was due to its stimulatory effect on GSH synthesis. This increase in GSH levels during IVM improves embryo development and quality, producing more embryos reaching the blastocyst stage on day 6, those most suitable for freezing.

Oogenesis and ovulation in normal conditions or induced by homologous hypophysis in Hoplias m. malabaricus (Pisces, Erythrynidae).

The macroscopical, histological and histochemical study of the ovary of Hoplias m. malabaricus during its annual cycle makes it possible to classify oocytes in nine stages, which characteristics, inherent to each stage, have given evidence of certain aspects still unknown for this species. The hormonal induction by homologous hypophysis makes it possible to obtain the final oocyte maturation and the ovulation.

Final maturation and ovulation provoked by supply of homologous hypophysis in Hoplias m. malabaricus (Pisces, Erythrinidae).

The final maturation and the ovulation were induced in recently collected specimenes of Hoplias m. malabaricus that show oocytes with complete vitellogenesis, by using homologous hypophysis. The hormonal supply was a gradual and positive results were obtained with 9 to 10 hypophysis/kg injected according to 3 different methods. The time of oocytes' maturation from the first dose ranges between 32 and 60 hours a 18 degrees C. The stages of maturation of the oocyte were controlled by intraovaric cannulations using a numerical index to determine the position of the germinal vesicle.