The present study aimed to verify the caprine semen characteristics during dry and rainy seasons in the Brazilian Northeast, and the influence of these seasons on cooled semen. Seminal volume, concentration, percentage of motile cells, vigor and spermatic morphology, as well as biochemical profile (fructose, citric acid, P, Ca 2+ , Mg, total proteins and phospholipase A2 activity) were analyzed...

Formaldehyde Crosslinking. Cells (10) suspended in growth medium are transferred as 40-ml aliquots into 50-ml tubes and placed on ice for 10 min. Then 1/10 volume of crosslinking solution (11% formaldehyde/0.1M NaCl/1mM Na-EDTA/0.5 mM NaEGTA/50mM Hepes, pH 8.0) is added directly to each tube. After 10-min incubation on ice, 1/20 vol of a 2.5-M glycine solution is added to each tube to stop the ...

The aim of the present work was to study a simple colorimetric and potentiometric biosensor based on urease inhibition by Pb (II) ions for its estimation in milk samples. Urease immobilized on nylon membrane by hydrosol gel method was used as the biocomponent to demonstrate the metal effect on the enzyme activity using phenol red as the pH indicator. A lower limit detection of 38.6μm was achiev...

An experimental design was applied to improve the reaction conditions for enzymatic synthesis of ampicillin from phenylglycine methyl ester (PGME) and 6-aminopenicillanic acid (6-APA), catalyzed by penicillin G acylase from E. coli immobilized on an agarose-glyoxyl derivative. The presence and magnitude of interactions between reaction variables were estimated using a 2 factorial design. A batc...

Haematologica vol. 85(5):May 2000 ature, although these differences were not statistically significant (p>0.1)(Table 1). According to previously established limits (10% of the mean value in all cases for SD and 8% for CV)6 good results were obtained for both reproducibility and accuracy control tests. Previous studies have demonstrated the reliability of the FACSCount cytometer for unstained sa...

In patients undergoing aortic valve replacement, allograft valves stored at 4OC in a nutrient medium have been associated with excellent immediate and long-term results. The effects of this method of prolonged storage on the antigenic, immunological, and cellular characteristics of these grafts are incompletely understood. This study was designed to study these phenomena in rat aortic valves su...

High pressure effects on the strength (stress) and elasticity/ deformability (strain) of surimi and turkey breast meat gels containing microbial transglutaminase (TGase) were evaluated. Pressurization of muscle proteins at 4oC prior to incubation at 25°C or 40°C (setting) increased gel strength 2–3 fold in uncooked surimi gels, but not in uncooked turkey gels. However, pressurization at 40°C or...

1. In anaesthetized cats, reversible nenal nerve denervation (cooling of the renal nerves on one side at 4OC for 16 min) was performed and its effects on haemodynamic and excretory functions of the ipsilateral and the contralateral kidneys were studied. 2. Renal nerve cooling did not cause any change in arterial pressure. Slight increase in blood flow, no change in glomerular filtration rate an...

An enzymatic assay for plasma homocysteine was developed that uses a crude lysate of E. coli containing the recombinant enzyme, methionine γ-lyase. The assay uses a commercially available fluorophore and 96-well microtiter plates; it can be performed manually or with the TECAN automated analyzer. The CVs for within-run and between-run precision are <10%. Close correlation (r >0.9) was obtained ...