Rheological Studies on the Reaction of Zein with Polyethylenemaleic Anhydride

There continues to be interest in developing solvent‐resistant articles from biobased renewable materials to successfully compete with petrochemical products. It was previously shown that reaction of zein with polyethylenemaleic anhydride (PEMA) provides articles that are solvent resistant. The gelation kinetics for the reaction of PEMA with zein was investigated rheologically to better understand this chemistry. The reaction of the nucleophilic groups on zein with the anhydrides on PEMA is the main cause for the gelation reaction. The gelation time was defined as being the point when the elastic modulus (G′) and viscous modulus (G″) cross. In this work, the rate of reaction, in terms of time to gelation, was studied in N,N‐dimethylformamide solution for which the amount of PEMA, the reaction temperature, and the overall reaction concentration were varied. Exponential relationships were found between the gelation time and % PEMA, temperature, and % solids, as well as between elastic modulus with either % PEMA or % solids. The concentration of PEMA had the largest impact on gelation time, for which going from 2.5% PEMA to 6% PEMA reduced the gelation time from 63,114 to 1,576 s. The temperature dependence of this gelation reaction was well described by an Arrhenius plot with an apparent activation energy of 50.5 kJ/mol.     

Hemorrhage in the central canal of the cervical spinal cord in a coonhound diagnosed with canine juvenile polyarteritis (steroid responsive meningitis-arteritis)

Patchy meningeal and parenchymal contrast enhancement of the spinal cord with multifocal central canal dilations was noted in a computed tomography myelogram of the cervical spine of a 6-month-old intact female coonhound with a confirmed diagnosis of canine juvenile polyarteritis and associated hemorrhage within the central canal.     

Green tea polyphenol extract regulates the expression of genes involved in glucose uptake and insulin signaling in rats fed a high fructose diet

Green tea has antidiabetic, antiobesity, and anti-inflammatory activities in animal models, but the molecular mechanisms of these effects have not been fully understood. Quantitative real-time polymerase chain reaction (PCR) was used to investigate the relative expression levels and the effects of green tea (1 and 2 g solid extract/kg diet) on the expression of glucose transporter family genes (Glut1/Slc2a1, Glut2/Slc2a2, Glut3/Slc2a3, and Glut4/Slc2a4) and insulin signaling pathway genes (Ins1, Ins2, Insr, Irs1, Irs2, Akt1, Grb2, Igf1, Igf2, Igf1r, Igf2r, Gsk3b, Gys1, Pik3cb, Pik3r1, Shc1, and Sos1) in liver and muscle of rats fed a high-fructose diet known to induce insulin resistance and oxidative stress. Glut2 and Glut4 were the major Glut mRNAs in rat liver and muscle, respectively. Green tea extract (1 g) increased Glut1, Glut4, Gsk3b, and Irs2 mRNA levels by 110, 160, 30, and 60% in the liver, respectively, and increased Irs1 by 80% in the muscle. Green tea extract (2 g) increased Glut4, Gsk3b, and Pik3cb mRNA levels by 90, 30, and 30% but decreased Shc1 by 60% in the liver and increased Glut2, Glut4, Shc1, and Sos1 by 80, 40, 60, and 50% in the muscle. This study shows that green tea extract at 1 or 2 g/kg diet regulates gene expression in the glucose uptake and insulin signaling pathway in rats fed a fructose-rich diet.     

Effects of oral powder electrolyte administration on packed cell volume,plasma chemistry parameters,and incidence of colic in horses participating in a 6-day 162-km trail ride

This study evaluated the effects of administering oral powder electrolytes on packed cell volume (PCV), plasma chemistry parameters, and incidence of colic in horses participating on a 6-day 162-km trail ride in which water was not offered ad libitum. Twenty-three horses received grain with powder electrolytes daily while 19 control horses received grain only. Horses were ridden approximately 32 km a day at a walk or trot. Packed cell volume and plasma chemistry parameters were analyzed daily. Episodes of colic were diagnosed and treated by a veterinarian unaware of treatment group allocation. Blood parameters and incidence of colic were compared between treatment groups. Electrolyte administration did not alter PCV or plasma chemistry parameters compared to controls. The incidence of colic was significantly higher in treated horses (P = 0.05). Oral powder electrolytes did not enhance hydration status or electrolyte homeostasis and may be associated with colic in horses participating on long distance trail rides similar to this model.     

Pharmacokinetics of buprenorphine following intravenous and intramuscular administration in male rhesus macaques (Macaca mulatta)

This study reports the pharmacokinetics of buprenorphine in conscious rhesus macaques (Macaca mulatta) after intravenous (i.v.) and intramuscular (i.m.) administration. Four healthy, opioid‐naïve, socially housed, adult male macaques were used. Buprenorphine (0.03 mg/kg) was administered intravenously as a bolus or intramuscularly on separate occasions. Blood samples were collected prior to, and up to 24 h, postadministration. Serum buprenorphine concentrations were analyzed with liquid chromatography–mass spectrometry. Noncompartmental pharmacokinetic analysis was performed with commercially available software. Mean residence time in the i.v. study as compared to the i.m. study was 177 (159–189) vs. 185 (174–214) min, respectively [median (range)]. In the i.v. study, concentration back‐extrapolated to time zero was found to be 33.0 (16.8–57.0) ng/mL [median (range)]. On the other hand, the maximum serum concentration found in the i.m. study was 11.8 (6.30–14.8) ng/mL [median (range)]. Rhesus macaques maintained concentrations >0.10 ng/mL for over 24 h in the i.v. study and over 12 h in the i.m. study. Bioavailability was found to be 68.1 (59.3–71.2)% [median (range)]. No significant adverse effects were observed in the monkeys at the 0.03 mg/kg dose of buprenorphine during either study.     

Broken eggs as a cause of infertility of coho salmon gametes

Egg content originating from ruptured ova progressively reduced the success of fertilization in coho salmon (Oncorhynchus kisutch) eggs. The salmon egg differs in ionic composition from the ovarian fluid in exhibiting higher K⁺ and Mg²⁺ and lower Na⁺ concentrations. Normal ovarian fluid induced spermatozoan motility whereas ovarian fluid contaminated with egg content progressively lost the ability to induce motility. Loss of motility was related to decreasing $\text{Na}{}^{\mathrm{+}}\text{K}{}^{\mathrm{+}}$ ratios in the ovarian fluid, indicating that reduced fertility may be caused by inactivation of sperm cells in the insemination medium. Removal of contaminated ovarian fluid by rinsing ova in isotonic media induced spermatozoan motility and restored fertility completely. The use of an isotonic NaHCO₃ solution for rinsing of ova is suggested as a routine procedure for artificial insemination in salmonids where the presence of broken eggs is suspected.