Evaluation of newborn canine viability by means of umbilical vein lactate measurement, apgar score and uterine tocodynamometry.

Newborn viability evaluation and early detection of fetal distress could contribute to reducing mortality at birth in canine species. High neonatal mortality rate in dogs is reported subsequent to complicated or uncomplicated whelping. Umbilical vein lactate and tocodynamometry could provide valuable clinical information to the obstetricians so that appropriate medical and surgical treatments or oxygen and warm administration can be properly and timely applied to mother and newborn pup. In humans, the fetal lactate level represents an objective indicator of fetal distress and a valid predictor of babies' survival. Fetal acidosis recognition by umbilical lactate (UL) measurement, APGAR score classification, and uterine activity monitoring during labour, can represent an advanced system in the evaluation of the canine newborn patient. The purpose of this study was to correlate UL levels with canine neonatal morbidity and mortality within 48 h of birth. We evaluated the relationship among neonatal parameters at birth (mucous membrane color, heart and respiratory rate, reflex irritability, mobility, suckling and vocalization, UL, weight, and temperature) with labour characteristics (uterine contractions recorded by the tocodynamometric system of Whelpwise ™ Veterinary Perinatal Specialties ®, delivery time, and pup presentation), in view to predict pup viability. We considered also vaginal parturition versus elective and emergency Caesarean section, and uterotonic drugs influence on delivery. Umbilical lactate concentration proved to be useful to predict canine neonatal mortality within 48 h of birth (P < 0.05). We identified 5 mmol/L of vein umbilical lactate concentration as the cut off value, allowing us to distinguish between healthy and distressed pups. Higher values of UL were related with distressed pups, whereas lower values characterized vigorous pups. Lactate concentrations lower than 5 mmol/L and APGAR scores higher than 9, related to mean delivery time of 105 min with effective uterine contractions (10 mm of Hg of strength or more, frequency from 4 to 12 contractions per hour, and 2-5 min in duration), should be considered good prognostic factors in canine labour and neonatology.

Expression, processing and secretion of a proteolytically-sensitive insect diuretic hormone by Saccharomyces cerevisiae requires the use of a yeast strain lacking genes encoding the Yap3 and Mkc7 endoproteases found in the secretory pathway.

A system is described for the heterologous expression of peptides in Saccharomyces cerevisiae. A synthetic gene encoding a precursor of the 41 amino acid Manduca sexta diuretic hormone (Mas-DH) was expressed at 0.8 mg/l purified peptide. A precursor of a mutant peptide of Mas-DH, Mas-DH[K22Q] was also expressed. The peptides were purified, then treated with peptidylglycine alpha-amidating enzyme to generate the alpha-amidated, mature, form of Mas-DH or Mas-DH[K22Q], which were biologically active. Successful expression of full-length Mas-DH+Gly depended upon the use of a protease-deficient yeast strain. In wild-type strains, Mas-DH+Gly was recovered only as proteolytic fragments, even in the presence of various protease inhibitors. Expression of Mas-DH+Gly in strains deficient in either the Mkc7 or the Yap3 protease reduced proteolysis, while no proteolysis of Mas-DH+Gly was detectable in a strain lacking both proteases. This protease-deficient strain may prove of general utility for expression of peptides. Analysis of recovered proteolytic fragments revealed a complex pattern of cleavage sites. Both the Yap3 and Mkc7 proteases preferred to cleave at a single Glu-Lys downward arrow-Glu-Arg site. Analysis of secondary cleavage sites showed that Yap3 preferred to cleave after either Lys or Arg and Mkc7 after Lys. This paper is the first report on the in vivo activity and specificity of Yap3 and Mkc7 expressed at physiological levels.