Expression of neutrophil gelatinase-associated lipocalin (NGAL) in peripheral nerve repair

Introduction: Trauma is one of the causes of peripheral nerve injuries. Free radicals increase after tissue damage. Free radicals are usually scavenged and detoxi?ed by antioxidants. In this study, we assessed the antioxidative role of the NGAL molecule in sciatic nerve repair in rats. Materials and methods: The sciatic nerves of 40 rats were crushed and the total mRNA of samples from day 1 and 3 and week 1, 3, 5 post injury was extracted. The expression of the NGAL gene was confirmed by RT-PCR. For immunohistochemistry analysis, the samples were ?xed in paraformaldehyde and cut in 20 micrometer slices by cryostat. Results: The expression of NGAL signi?cantly upregulated in day 1, 3 and week 1 following the crushing of sciatic nerves in comparison with the intact nerves. Immunohistochemistry results also confirmed the protein expression of this gene. Discussion: The NGAL molecule showed upregulation in the degeneration process after nerve injury, so it may play an important role in nerve repair.     

Fragmentation in eucalypt woodlands promotes nest‐tree occupancy by a despotic species,the noisy miner (Manorina melanocephala)

The effects of habitat fragmentation as a threat to biodiversity are well known; decreased connectivity can potentially influence population processes and dynamics, resulting in smaller, isolated populations that may not function optimally. However, fragmentation may also increase the amount of edge or ecotone habitat available to open country species, benefiting their populations and enabling them to dominate remnant habitats. Noisy miners (Manorina melanocephala) are one such species, occupying eastern‐Australian eucalypt woodlands. They are considered a ‘despotic’ species, in that their presence negatively impacts woodland avifauna biodiversity due to their aggressive exclusion of other taxa from occupied areas. Despite this well‐known impact, little information exists on the patterns of nest‐tree occupancy by noisy miners within eucalypt woodlands. In the current study, we explored the patterns of nest‐tree occupancy by noisy miners across two successive years, aiming to identify preferences for breeding areas relative to vegetation structure. Our results show that both habitat fragmentation and the characteristics of individual eucalypt trees in an area influenced nest‐tree occupancy. Noisy miners constructed nests in trees near the edge of woodland patches more often than expected. Moreover, the nest tree chosen was a eucalypt that was significantly smaller than randomly selected trees from the surrounding area. The results highlight the importance of habitat management measures that may reduce the suitability of woodland patches as nesting sites for this species, in order to mitigate the severe effects of this despotic edge specialist.     

Effects of chronic heat stress on testicular structures,serum testosterone and cortisol concentrations in developing lambs

The objective of this study was to investigate the effect of high and moderate summer ambient temperatures on testicular structures and endocrine profile of developing ram lambs. Twenty fall-born ram lambs were randomly divided into two groups: animals were kept outdoor (n = 10) under ambient temperature (31–50 °C) or maintained indoor (26–32 °C) from May to October 2007. Daily maximum ambient temperature was recorded for both environments. Monthly serum testosterone and cortisol concentrations were compared between two groups throughout the experiment. The animals were slaughtered at the end of the study and their testes subjected to histopathology exam. The results showed that maximum outdoor ambient temperature was significantly higher than indoor. There was no difference between two groups on serum testosterone concentration. There was no effect on serum cortisol levels except in August and October. Histolopathological examination revealed a severe testicular degeneration with significant germ line degeneration without any impact on somatic cells. In conclusion, direct exposure of developing lambs during non-breeding season impairs testicular germ cells without significant effect on testicular endocrine function.     

Superovulatory response of Sistani cattle to three different doses of FSH during winter and summer

Objective of the present study was to investigate the effect of season and dose of FSH on superovulatory responses in Iranian Bos indicus beef cattle (Sistani). Cyclic cows, in summer (n=16) and winter (n=16), were assigned randomly to three dose-treatment groups of 120 (n=10), 160 (n=12) and 200 (n=10) total mg of Folltropin-V with injections given twice daily for 4 days in decreasing doses. Estrous cycles were synchronized with two prostaglandin F2alpha injections given 14 days apart. From day 5 after the ensuing cycle, daily ovarian ultrasonography was conducted to determine emergence of the second follicular wave at which time superovulation was initiated. Relative humidity, environmental and rectal temperatures were measured at 08:00, 14:00 and 20:00 h for the 3 days before and 2 days after the estrus of superovulation. Non-surgical embryo recovery was performed on day 7 after estrus. The effects of season, dose, time of estrous expression and all two-way interactions were evaluated on superovulatory responses: total numbers of CL, unovulated follicles (10 mm), ova/embryo, transferable and non-transferable embryos. Season (summer or winter), doses of Folltropin-V (120, 160 or 200 mg NIH) and time of estrous expression (08:00, 14:00 or 20:00 h) did not affect the number of transferable embryos (3.1+/-0.58). When superovulatory estrus was detected at 08:00, a FSH dose effect was detected with the greatest numbers of CL (12.2+/-0.87) and total ova/embryos (12.2+/-1.46) occurring with 200 mg FSH (dosextime of estrous expression; P<0.01).     

Homologous and heterologous protein import into mitochondria isolated from the green alga Chlamydomonas reinhardtii

We have established a homologous system for studying mitochondrial protein import in Chlamydomonas reinhardtii, using C. reinhardtii precursor proteins and mitochondria isolated from C. reinhardtii. The precursors of the F₁ ATP synthase subunit and the Rieske FeS protein were imported into mitochondria with high efficiency, while the F₁ subunit precursor was imported with much lower efficiency. The import of heterologous precursor proteins from higher plants was also less efficient. The precursor of the C. reinhardtii PsaF chloroplast protein was converted into a protease-protected form upon incubation with mitochondria. In vitro processing studies revealed that in contrast to the situation in higher plants, the processing of the precursors was catalysed by a soluble, matrix-located peptidase.     

Meiotic competence and DNA damage of porcine oocytes exposed to an elevated temperature

The present study was conducted to investigate the effects of the length of exposure to an elevated temperature (41 degrees C) on the meiotic competence and DNA damage of porcine oocytes. Oocytes were recovered from ovaries, loaded into straws, and then exposed at 41.0 or 38.5 degrees C (sham control) for 0, 0.5, 1.0, or 1.5h, followed by culture for 44 h. The proportion of oocytes reaching the metaphase II (MII) stage gradually decreased with increasing exposure time, irrespective of the exposure temperature. A higher proportion of oocytes stored at 38.5 degrees C reached MII (57-63%) than those exposed to 41 degrees C (14-29%; P<0.01). The proportion of total oocytes with DNA fragmentation gradually increased with increasing exposure time, irrespective of the exposure temperature. The proportion of DNA fragmentation in total oocytes exposed to 41 degrees C (37-57%) was higher (P<0.01) than that in total oocytes stored at 38.5 degrees C (14-24%). When the oocytes were stored at 38.5 degrees C for up to 1.5 h, there were no differences in the proportions of MII-stage oocytes, with DNA-fragmented nuclei among all groups (P>0.05). However, a higher proportion of MII-stage oocytes exposed to 41 degrees C for more than 1h exhibited DNA-fragmented nuclei, compared with MII-stage oocytes stored at 38.5 degrees C (P<0.05). In conclusion, exposure of porcine oocytes to an elevated temperature had a detrimental effect on the meiotic competence and quality of oocytes; furthermore, the effect was dependent on the duration of exposure.     

Enzymatic hydrolysis of molasses

Kinetic studies of the enzymatic hydrolysis of molasses were conducted using glucoamylase. Central Sugar Refinery SDN BHD contains 13-20% glucose. The molasses was diluted and the kinetic experiments were conducted at 67 degrees C with 100-1000 mg/l of glucoamylase. The glucose contents of the molasses were enhanced after hydrolysis of molasses solution with 1000 mg/l glucoamylase. A Lineweaver-Burk plot was obtained based on enzyme kinetic data. The rate constant, Km and maximum reaction rate, Vmax for 500 mg/l of glucoamylase were 100 mmol/l (18 g/l) and 5 mmol/l min (0.9 g/l min), respectively. The maximum reaction rate, Vmax for 1000 mg/l of glucoamylase was doubled, to 100 mmol/l (18 g/l) and the rate constant, Km was the same for 500 mg/l of glucoamylase. The substrate inhibition model was noncompetitive based on the resulting Lineweaver-Burk plot for enzyme concentration of 500 and 1000 mg/l.