Hematologic and serum protein reference values of the Octodon degus

Blood and serum from normal degus (Octodon degus) that ranged in age from 3 to 48 months were analyzed to determine reference hematologic and serum protein values. Both sexes were evaluated and were similar. The hematologic and serum protein values for males were: erythrocytes, 8.69 +/- 0.19 X 10(6) /microliter; packed cell volume, 42.1% +/- 0.59%; hemoglobin, 12.0 +/- 0.15 g/dl; leukocytes, 8.50 +/- 0.39 X 10(3)/microliter; neutrophil-to-lymphocyte ration, 40:60; and total protein, 5.70 +/- 0.20 g/dl. The hematologic and serum protein values for females were: erythrocytes, 8.94 +/- 0.16 X 10(6)/microliter; packed cell volume, 40.0% +/- 0.61%; hemoglobin, 11.7 +/- 0.17 g/dl; leukocytes, 8.20 +/- 0.36 X 10(3)/microliter; neutrophil-to-lymphocyte ratio, 40:60; and total protein, 5.62 +/- 0.18 g/dl. The hematologic and serum protein values for the degu were similar in some respects to values reported for guinea pigs and rats.     

Leak in evaporated milk by anodic stripping voltammetry and atomic absorption spectrophotometry: cooperative interlaboratory study

The results of a cooperative study on the determination of lead in evaporated milk, using a double blind referee technique, are reported. This study was designed to determine the normal variability of methods currently used for lead analysis by canned food industry laboratories. Twenty-three laboratories participated in this study. Each laboratory was instructed to use atomic absorption spectrophotometry (AOAC 25.065), anodic stripping voltammetry, or carbon rod atomic absorption spectrophotometry. Overall, the results appear to be in close agreement with the spiking levels. The coefficient of variation for all laboratories was 36.0% at the 0.15 ppm lead level and 16.8% at the 0.40 ppm lead level.     

Effect of selenium supplementation on semen characteristics of Brazil's ram

The aim of this study was to investigate the effects of different concentrations of oral supplementation with selenium (Se) upon ram sperm parameters. Thirty rams managed in stall under intensive system were used and divided into five groups (six animals per group) as follows: control group (G1) mineral mixture supplementation without Se, group 2 (G2) mineral mixture supplemented with 5 mg/kg Se, group 3 (G3) supplemented with 10 mg/kg Se, group 4 (G4) supplemented with 15 mg/kg Se and group 5 (G5) supplemented with 20 mg/kg Se. For each group, there was an adjustment period of 14 days. The experimental period was 350 days. Every 56 days, the animals were weighed and semen samples were collected by electroejaculation. Semen analysis included volume, mass moviment, total motility, vigour, concentration and morphology. For plasmatic and acrosomal membrane integrity evaluation and mitochondrial membrane potential were used a combination of fluorescent probes. Differences between means values obtained by analysis of variance were verified by Tukey test with 5% probability. There was no statistical difference between treatment groups in relation to volume, mass moviment, total motility, vigour, concentration, plasma and acrosomal membrane integrity (p > .05). Sperm morphology was different between treatment groups, the G1 (0 mg of selenium) had the highest percentage of major defects (11.11 ± 1.11^a; p < .05). It was concluded that selenium decrease the percentage of sperm defects and did not directly influence on ram sperm volume, mass moviment, total motility, vigour, concentration and membrane integrity.     

Neuroendocrine,Metabolic and Genomic Cues Signalling the Onset of Puberty in Females

Puberty is the result of a dynamic interaction between genetic factors and environmental cues, all of which lead to the attainment of reproductive capacity. Thus, significant changes in hormone secretion occur from the pre‐pubertal to the pubertal stage. The objective of this review is to provide an update of some endocrine, physiological, metabolic and genetic concepts involved in the establishment of the hypothalamic‐hypophyseal‐gonadal axis function promoting the onset of the reproductive function during puberty. To achieve this purpose, basic aspects of the function of the hypothalamic‐hypophyseal‐gonadal axis, the control of the axis by neurotransmitters and the interaction between reproductive function and metabolic status will be considered. Finally, the role of the novel kisspeptin system and the GPR54 receptor as modulators of puberty will be considered, in addition to the hierarchical expression of the main genes acting as regulators of the onset of puberty.     

p-Hydroxyphenylpyruvate dioxygenase inhibitor-resistant plants

The enzyme p-hydroxyphenylpyruvate dioxygenase (HPPD) catalyzes the formation of homogentisic acid, the aromatic precursor of plastoquinone and vitamin E. HPPD is the specific target of several herbicide families: isoxazoles, triketones and pyroxazoles. Its inhibition results in the depletion of the plant plastoquinone and vitamin E pools, leading to bleaching symptoms. These herbicides are very potent for the selective pre- and in some cases post-emergence control of a wide range of broadleaf and grass weeds in maize and rice. Their herbicidal potential raised interest in the development of highly resistant transgenic crops. This goal was first achieved by over-expression of a bacterial HPPD in crop plants, and an increased level of resistance was obtained by using a mutant enzyme. A second strategy based on bypassing HPPD in the production of homogentisate was then developed. Recently, a third strategy of resistance based on the increase of p-hydroxyphenylpyruvate substrate flux has been developed. This was achieved by the introduction of the yeast prephenate dehydrogenase gene (PDH) into transgenic plants already overexpressing HPPD. In addition to a high level of herbicide resistance, a massive accumulation of vitamin E, mainly tocotrienols, was observed in leaves of the transgenic HPPD-PDH plants.     

Field validation and assessment of an enzyme-linked immunosorbent assay for detecting chronic wasting disease in mule deer (Odocoileus hemionus), white-tailed deer (Odocoileus virginianus), and Rocky Mountain elk (Cervus elaphus nelsoni).

Tissue samples (n = 25,050 total) from 23,256 mule deer (Odocoileus hemionus), Rocky Mountain elk (Cervus elaphus nelsoni), and white-tailed deer (Odocoileus virginianus) collected statewide in Colorado were examined for chronic wasting disease (CWD) using an enzyme-linked immunosorbent assay developed by Bio-Rad Laboratories, Inc. (brELISA), in a 2-phase study. In the validation phase of this study, a total of 4,175 retropharyngeal lymph nodes (RLN) or obex (OB) tissue samples were examined independently by brELISA and immunohistochemistry (IHC). There were 137 IHC-positive samples and 4,038 IHC-negative samples. Optical density (OD) values from brELISA were classified as "not detected" or "suspect" based on recommended cutoff values during the validation phase. Using IHC-positive cases as known CWD-infected individuals and assuming IHC-negative cases as uninfected, the relative sensitivity of brELISA depending on species ranged from 98.3% to 100% for RLN samples and 92.1% to 93.3% for OB samples; the relative specificity of brELISA depending on species ranged from 99.9% to 100% for RLN samples and was 100% for OB samples. Overall agreement between brELISA and IHC was > or = 97.6% in RLN samples and > or = 95.7% in OB samples of all species where values could be calculated; moreover, mean brELISA OD values were > or = 46X higher in IHC-positive samples than in IHC-negative samples. Discrepancies were observed only in early-stage cases of CWD. Based on the validation phase data, only RLN samples were collected for the field application phase of this study and only samples with brELISA OD values > 0.1 were examined by IHC. Among 20,875 RLN samples screened with brELISA during this second testing phase, 155 of 8,877 mule deer, 33 of 11,731 elk, and 9 of 267 white-tailed deer samples (197 total) had OD values > 0.1 and were further evaluated by IHC to confirm evidence of CWD infection. Of cases flagged for IHC follow-up, 143 of 155 mule deer, 29 of 33 elk, and all 9 white-tailed deer were confirmed positive. Mean (+/- SE) OD values for IHC-positive cases detected during the field application phase were comparable with those measured in RLN tissues during the validation phase. Based on these data, brELISA was determined to be an excellent rapid test for screening large numbers of samples in surveys designed to detect CWD infections in deer and elk populations.     

In vitro bactericidal efficacy of equine polymorphonuclear leukocytes against Corynebacterium equi

Polymorphonuclear leukocytes from adult horses were separated from whole blood, using a 2-step Percoll gradient, and were tested for bactericidal function against Corynebacterium equi. Staphylococcus aureus, an organism against which equine neutrophils have proved efficacy, was a positive control. The percentage of uptake after a 15-minute preincubation of the neutrophils and bacteria in the presence of normal horse serum was also calculated. The results indicated that equine neutrophils effectively phagocytosed and killed C equi and S aureus. The percentage of uptake for S aureus (95% +/- 3%) was greater than that for C equi (85% +/- 6%) (P less than 0.001), but the bactericidal efficacy was equivalent. More than 90% of the ingested or attached bacteria were destroyed during the 3-hour incubation period (mean percentage of C equi killed = 96 +/- 2%; mean percentage of S aureus killed = 91 +/- 8%). These results indicated that a failure of bacterial killing by neutrophils is unlikely to be important in the pathogenesis of C equi pneumonia in the horse.     

Differential Expression of IGF Family Members in Heat‐Stressed Embryos Produced In Vitro from OPU‐Derived Oocytes of Nelore (Bos indicus) and Holstein (Bos taurus) Cows

The IGF system is related to embryo quality. We aim to determine the effect of the heat stress on the mRNA expression of IGF1 and IGF2, IGFR1 and IGFR2, IGFBP2 and IGFBP4, and PAPPA in in vitro production (IVP) blastocysts from Nelore and Holstein after ovum pick up (OPU) to better understand the differences between these breeds. Oocytes from four Nelore and seven Holstein were collected in six OPU sessions. Following in vitro maturation and fertilization using six Nelore or Holstein sires, embryos were divided into control (cultured at 39°C) and heat stress (HS; exposed to 41°C for 9 h). Blastocysts were submitted to RNA extraction. The IGF1 expression was higher in blastocysts under HS in both breeds, and the expression of IGFBP2 and IGFBP4 was higher in Holstein blastocysts under HS. The high PAPPA expression and the low expression of IGFBP2 and IGFBP4 are associated with a more efficient degradation of IGFBPs, which results in greater IGF bioavailability in Nelore blastocysts and may contribute to the superior HS tolerance in Nelore, when compared to Holstein.