Precolumn phenylisothiocyanate derivatization and liquid chromatography of amino acids in food

A precolumn phenylisothiocyanate derivatization method is described for the determination of amino acids in protein hydrolysates from a wide variety of complex food matrixes, with and without performic acid oxidation pretreatment. Analysis of samples that were not pretreated with performic acid was necessary since this pretreatment destroyed an average of 25% of the histidine and 87% of the tyrosine present in the food samples. This method is rapid and reproducible; coefficients of variation between duplicate analyses of the same food item were less than 5% for a majority of the amino acids. Occasionally, variation between duplicate analyses for histidine and tyrosine was greater than 10%. Recoveries of amino acids added to samples were in the 100% range.     

Drinking preferences in chinchillas (Chinchilla laniger), degus (Octodon degu) and guinea pigs (Cavia porcellus)

Chinchilla (Chinchilla laniger), degus (Octodon degus) and guinea pigs (Cavia porcellus) are South American rodents living in a semi‐arid habitat with varying, species‐specific adaptations to water deprivation. Nonetheless, several diseases have been linked to insufficient water intake when these species are kept as pets, such as urolithiasis or obstipation. This study evaluated preferences for drinking systems. Six animals of each species were given a choice between an open dish and a nipple drinker. Food intake and water intake were measured daily for 13 days. Chinchillas in this study had significantly lower water intakes than the other two species, indicating particular species‐specific adaptations to aridity. All chinchillas favoured open dishes, whereas the degus and guinea pigs had variable individual preferences. Water intake of chinchillas was similar or higher in this study than in previous studies where nipple drinkers were used. The results indicate that degus and guinea pigs can meet their drinking water needs with nipple drinkers; for chinchillas, other drinking systems may be more adequate.     

Fetuses of lean and obese swine in late gestation: body composition, plasma hormones and muscle development

The development of obesity in porcine fetuses was investigated using a lean and obese strain of pigs at 80, 90, 100 and 110 d of gestation. In absolute terms, fetuses of obese gilts (FO) generally had lower carcass weight and contained less total protein, dry matter and ash than fetuses of lean gilts (FL). In relative terms (percentage of wet carcass weight) FO, compared with FL, generally had decreased percentages of water and increased percentages of protein and lipid. Comparisons based on absolute terms revealed body composition of the strains to be different at 90 d, indicating that factors responsible for obese-type growth were active before that time. Both body composition and hormone concentration differences were most pronounced at later gestation ages. Depressed growth hormone, elevated cortisol, and a tendency toward elevated insulin concentrations in fetal plasma were apparent in late gestation for FO compared with FL. These hormonal patterns are consistent with onset of obesity in FO in late gestation. Greater weights of semitendinosus and longissimus muscles were observed in FL vs FO at 90, 100 and 110 d of gestation (P less than .05). These greater muscle weights were generally accompanied by greater contents of RNA, DNA and protein in FL muscles at these same ages. However, at 80 d, FL had greater absolute DNA content in semitendinosus muscle whereas muscle weight was similar between the strains. This suggests that greater muscle weights for FL than FO were caused by more nuclei in muscle of FL. In general, indices of hypertrophy (protein/DNA) and protein synthetic capacity (RNA/DNA) of muscle were usually similar for both strains at all gestation ages. It is concluded that decreased muscle growth in late gestation of FO compared with FL is more related to fewer total nuclei and perhaps fewer myofibers than to an impaired cellular capacity for protein synthesis.     

Relationships between a proprietary index, bispectral index, and hemodynamic variables as a means for evaluating depth of anesthesia in dogs anesthetized with sevoflurane

OBJECTIVE: To evaluate relationships among various techniques for monitoring anesthetic depth in sevoflurane-anesthetized dogs undergoing orthopedic surgery. ANIMALS: 10 dogs. PROCEDURE: Dogs were medicated with acepromazine (0.05 mg/kg, IM), buprenorphine (0.01 mg/kg, IM), and atropine (0.04 mg/kg, IM). Anesthesia was induced and maintained with sevoflurane. Cardiovascular and respiratory responses were monitored. Anesthetic depth was monitored by use of the bispectral index (BIS), and a proprietary index was used to monitor activity of the autonomic nervous system. RESULTS: A significant decrease in BIS was seen after induction but concurrent changes were not observed for the other techniques. The proprietary index increased significantly after intubation, but no changes were seen for the other techniques. No significant changes were detected during incision or when higher nociceptive stimuli were applied. We did not identify a correlation between BIS and the proprietary index, the proprietary index and hemodynamic variables, or the BIS and hemodynamic variables during induction and maintenance. A significant increase in the proprietary index and BIS was detected at the time of resumption of reflexes. During anesthetic recovery, a correlation was found between the proprietary index and BIS but not between hemodynamic variables and the other techniques. CONCLUSIONS AND CLINICAL RELEVANCE: A significant increase in the proprietary index, but not the BIS or hemodynamic variables, was detected during intubation. Anesthetic induction with sevoflurane did not prevent the sympathetic stimulus attributable to tracheal intubation. Monitoring of hemodynamic variables does not provide sufficient information to allow clinicians to evaluate stress during anesthetic recovery.