Effect of Different Extenders on In Vitro Characteristics of Feline Epididymal Sperm During Cryopreservation

To evaluate and compare the efficacy of various extenders for the cryopreservation of epididymal cat spermatozoa, two experiments were planned. Bovine and equine commercial extenders in the experiment 1 and TRIS–egg yolk–based extenders in experiment 2 were separately studied since the number of sperm collected per cat is reduced. Epididymal sperm samples were packaged into 0.25‐ml straws and frozen. Vigour, motility, morphology, acrosome status, sperm viability and functional membrane integrity were assessed at collection, after cooling and after thawing, while DNA integrity was evaluated at 0‐ and 6‐h post‐thaw. Experiment 1 compared the effect of three non‐feline commercial extenders – based on TRIS–egg yolk (Triladyl), egg‐yolk‐free medium (AndroMed) and skimmed milk‐egg yolk (Gent) – on the quality of frozen‐thawed epididymal cat sperm. Values for sperm motility and functional membrane integrity in cooled sperm diluted in Triladyl were higher (p < 0.001) than those recorded for Andromed and Gent. Except sperm morphology, the other assessed characteristics showed significant higher values in frozen‐thawed sperm diluted in Triladyl than in Andromed and Gent extenders. Experiment 2 analysed the effects of three TRIS–egg yolk–based extenders, one non‐feline commercial (Triladyl) and the other two prepared using different monosaccharides (glucose and fructose), on freezing‐thawed sperm. Results showed that specifically prepared extenders for cryopreservation of feline spermatozoa performed better than the commercial extender Triladyl, although sperm quality during the freezing‐thawing process did not significantly differ associated with the type of monosaccharide (glucose vs fructose) added to the mentioned extenders. Although TRIS–egg yolk–based extenders prepared in experiment 2 improved sperm cryoprotection, Triladyl remains a good option for practitioners who, for ease of use and availability, prefer to work with commercial extenders.     

Sara Arndt:收藏优雅走过的痕迹

文艺复兴时期风格的壁画前,香槟色的水晶吊灯摇曳生姿;1950年代的古董小边柜上摆放着几盏中东风韵的彩色烛台;朴素无常的实木餐桌简雅而温暖:设计师莎拉·阿恩特不仅喜欢周游世界,更喜欢把在世界各地发现的好看又实用的古董运用到她的设计中。     

Multiple-step melting in two-dimensional hexatic liquid-crystal films

An unexpected three-stage melting transition has been observed in two-dimensional (2D) free-standing liquid-crystal films by in situ electron-diffraction and optical-reflectivity measurements. These data suggest the existence of two phases between the 2D solid and liquid: a hexatic phase and, at a higher temperature, an intermediate liquid phase with hexatic-like positional correlations ( approximately 40 angstroms) but no long-range orientational order. Previous high-resolution heat-capacity measurements have revealed a divergent-like anomaly at the hexatic-liquid transition that sharply contradicts the predictions of 2D melting theories. The observation of an intermediate isotropic phase may alter our understanding of 2D melting and lead to reconciliation between current experiments and theories.     

Klymollins T–X,Bioactive Eunicellin-Based Diterpenoids from the Soft Coral Klyxum molle

Five new eunicellin-based diterpenoids, klymollins T–X (1–5), along with two known compounds (6 and 7) have been isolated from the soft coral Klyxum molle. The structures of these new metabolites were elucidated by extensive spectroscopic analysis and by comparison with related known compounds. Compound 5 was found to exert significant in vitro anti-inflammatory activity against LPS-stimulated RAW264.7 macrophage cells. Furthermore, compounds 4 and 7 were shown to exhibit cytotoxicity against a limited panel of human cancer cell lines.     

Neuroprotective Effect of the Marine-Derived Compound 11-Dehydrosinulariolide through DJ-1-Related Pathway in In Vitro and In Vivo Models of Parkinson’s Disease

Parkinson’s disease (PD) is a neurodegenerative disorder characterized by tremor, rigidity, bradykinesia, and gait impairment. In a previous study, we found that the marine-derived compound 11-dehydrosinulariolide (11-de) upregulates the Akt/PI3K pathway to protect cells against 6-hydroxydopamine (6-OHDA)-mediated damage. In the present study, SH-SY5Y, zebrafish and rats were used to examine the therapeutic effect of 11-de. The results revealed the mechanism by which 11-de exerts its therapeutic effect: the compound increases cytosolic or mitochondrial DJ-1 expression, and then activates the downstream Akt/PI3K, p-CREB, and Nrf2/HO-1 pathways. Additionally, we found that 11-de could reverse the 6-OHDA-induced downregulation of total swimming distance in a zebrafish model of PD. Using a rat model of PD, we showed that a 6-OHDA-induced increase in the number of turns, and increased time spent by rats on the beam, could be reversed by 11-de treatment. Lastly, we showed that 6-OHDA-induced attenuation in tyrosine hydroxylase (TH), a dopaminergic neuronal marker, in zebrafish and rat models of PD could also be reversed by treatment with 11-de. Moreover, the patterns of DJ-1 expression observed in this study in the zebrafish and rat models of PD corroborated the trend noted in previous in vitro studies.     

Size Dependence of Structural Metastability in Semiconductor Nanocrystals

The kinetics of a first-order, solid-solid phase transition were investigated in the prototypical nanocrystal system CdSe as a function of crystallite size. In contrast to extended solids, nanocrystals convert from one structure to another by single nucleation events, and the transformations obey simple unimolecular kinetics. Barrier heights were observed to increase with increasing nanocrystal size, although they also depend on the nature of the nanocrystal surface. These results are analogous to magnetic phase transitions in nanocrystals and suggest general rules that may be of use in the discovery of new metastable phases.     

Development and fast screening of salbutamol residues in swine serum by an enzyme-linked immunosorbent assay in Taiwan

The analysis of salbutamol in swine serum is the more practical basis for large scale surveillance programs in Taiwan. Objectives of the study were to develop a new assay and to compare with a commercially available kit in field test screens. A simple and reliable enzyme-linked immunosorbent assay (ELISA) to monitor the presence of beta-agonist, salbutamol, in 1,358 field samples of swine serum that were collected from local meat markets was described. The method proved to be suitable and sensitive for the detection of beta-agonist residues caused by growth promoting dosage. The limit of detection of the developed ELISA directly performed on diluted serum was 0.25 ng/mL. The application and the results of two ELISA kits (homemade and commercially available) for the screening of salbutamol were presented. For further confirmation, all samples that showed to be ELISA positive for salbutamol residues were analyzed by GC-MS. Adopting 1 ng/mL salbutamol as a cutoff value, the commercial beta-agonist ELISA had a sensitivity of 89.2% and a specificity of 86.7% versus GC-MS at a cutoff of 1 ng/mL. The homemade salbutamol ELISA had a sensitivity of 81.1% and a specificity of 98.6% and gave a low proportion of false-positive rate results. The reliability of the developed kit in terms of the percentage of false-positive rate results is evaluated. In conclusion, a sensitive, specific salbutamol ELISA has been developed that could serve as a rapid screening assay, and the detection of positive samples at the place of sampling can result in more effective control of the illegal use of beta-agonists.     

Effect of Different Manganese Concentrations during in vitro Maturation of Bovine Oocytes on DNA Integrity of Cumulus Cells and Subsequent Embryo Development

Manganese (Mn) is a trace element present in forages and cereals, and its concentration depends on soil status. Manganese deficiency in cattle, goats and ewes not only impairs oestrous cycle but reduces calf birth weight. The achievement of the first oestrus is delayed, and more attempts are necessary to obtain a successful conception. This study was conducted to investigate the effect of the availability of supplemental Mn during IVM on DNA damage of cumulus cells and total glutathione (GSH) content in oocytes and cumulus cells. The effect of supplementary Mn during IVM on subsequent embryo development was also studied. The results reported here indicate (i) DNA damage in cumulus cells decreased with 0, 2, 5 and 6 ng/ml Mn supplementation during IVM (p < 0.05). (ii) Intracellular GSH‐GSSG content increased (p < 0.01) with different Mn concentrations in oocytes and cumulus cells. Also, cumulus cell number per cumulus oocyte‐complexes (COC) did not differ either before or after IVM. (iii) Addition of Mn to maturation medium resulted in similar cleavage rates (p > 0.05) at 0, 2, 5 and 6 ng/ml Mn. However, subsequent embryo development to blastocyst stage was significantly higher (p < 0.01) in oocytes matured with 5 and 6 ng/ml Mn. (iv) There was also an increase (p < 0.05) in mean cell number per blastocyst obtained from oocytes matured with 5 and 6 ng/ml respect to zero Mn (IVM alone) and 2 ng/ml Mn. This study provides evidence that optimal embryo development to the blastocyst stage was partially dependent on the presence of Mn during IVM. Moreover, the availability of Mn during oocyte maturation ensures ‘normal’ intracellular GSH content in COCs and protects DNA integrity of cumulus cells.     

High Embryonic Recovery Rates with In vivo and Ex vivo Techniques in the Bitch

The embryonic collection techniques in dogs present a vast methodological variation and low recovery rates. The objectives were to compare and describe two techniques as to the recovery of canine embryos, on the 12th day after the first mating or artificial insemination. Embryos were recovered through uterine horn flushing in vivo, before performing the ovariohysterectomy (OHE) (Group 1; n = 9) or ex vivo, immediately after the OHE (Group 2; n = 9). In total, 43 and 47 embryonic structures were recovered in Groups 1 and 2, respectively. There was no significant difference (p > 0.05) between groups on recovery rates (72.8% and 81.0%, respectively). We inferred that both in vivo and ex vivo techniques allow a high rate of embryonic recovery; in the collection technique prior to the OHE, it is essential to carefully handle the reproductive system during the trans‐surgical period and that the 12th day (D12) after the first mating/artificial insemination is an efficient option for the high recovery rate of morulae and blastocysts.     

Niacin,thiamin, iron and protein status of humans as affected by the consumption of tea (Camellia sinensis) infusions

The objective of the project was to determine the effects of tea (Camellia sinensis) leaf beverage consumption on the apparent utilization of niacin, thiamin, and protein in human subjects. During two randomly arranged experimental periods of 14 days each, 10 adult female human subjects were fed a constant (same foods each day), measured, laboratory-controlled diet. Tea was fed during one period while no tea was allowed during the other period. A dehydrated black tea infusion product (instant tea, 8 g/subject/day/dry weight basis) was used which subjects were allowed to dilute in water. Subjects made complete collections of urine and stools. Fasting blood samples were drawn at the end of each experimental period. No effects on protein status were demonstrated. Urinary thiamin losses were depressed with the use of tea but niacin losses were increased. Blood serum concentrations of thiamin diphosphate also were depressed during the tea drinking period as compared to values during the non-tea period. No significant effect on blood serum levels of nicotinaminde or N-methylnicotinamine were found but values tended to be lower during the tea than the non-tea period. These results suggest that tea consumption inhibits the utilization of thiamin. However, niacin availability was unaffected by tea drinking. Because of the decreased availability of thiamin, the need for niacin was depressed which caused a greater than expected urinary loss of this vitamin.Published as University of Nebraska Journal Articles Series No. 9496. Supported by University of Nebraska Agricultural Research Division Project 91-031 and U.S.D.A. C.S.R.S. Regional Project W-143.