The role of Haemophilus somnus in bovine early embryonic death. III. The effect of the organism on embryos by day 21 postbreeding

A study using 11 healthy, mature Holstein-Friesian heifers was designed to determine whether 1) H. somnus induces gross and/or histopathological changes of the uterine tract and embryos, 2) H. somnus has a short and/or long-term effect on the ovarian activity, 3) prior exposure to H. somnus would modulate the effect of a second exposure to the organism. Superovulated heifers were artificially iseminated 12 and 24 h after standing estrus using high-quality, Haemophilus-free semen from a single ejaculate of one bull. Control heifers (Group 1, n = 2) were infused by intrauterine route, 12 h after the second insemination, with 10 ml of 0.85% sterile phosphate buffered saline (PBS) as a placebo. The treatment heifers were exposed by intrauterine infusion, 12 h after the second insemination, to approximately 1.5 x 10(9)H. somnus organisms (Iowa strain 1229) suspended in 10 ml of 0.85% sterile PBS. Group 2 (n = 2) treatment heifers were exposed 21 d prior to embryo recovery; Group 3 treatment heifers (n = 3) were exposed 5 mo prior to embryo collection; and Group 4 treatment heifers were exposed twice, 5 mo apart with the second exposure 21 d prior to embryo recovery. All animals were slaughtered and the whole genital tract was removed for pathological examination and embryo recovery. There were minimal pathological changes in the uterus. However, H. somnus significantly affected (P 相似文献   

Indel‐seq: a fast‐forward genetics approach for identification of trait‐associated putative candidate genomic regions and its application in pigeonpea (Cajanus cajan)

Identification of candidate genomic regions associated with target traits using conventional mapping methods is challenging and time‐consuming. In recent years, a number of single nucleotide polymorphism (SNP)‐based mapping approaches have been developed and used for identification of candidate/putative genomic regions. However, in the majority of these studies, insertion–deletion (Indel) were largely ignored. For efficient use of Indels in mapping target traits, we propose Indel‐seq approach, which is a combination of whole‐genome resequencing (WGRS) and bulked segregant analysis (BSA) and relies on the Indel frequencies in extreme bulks. Deployment of Indel‐seq approach for identification of candidate genomic regions associated with fusarium wilt (FW) and sterility mosaic disease (SMD) resistance in pigeonpea has identified 16 Indels affecting 26 putative candidate genes. Of these 26 affected putative candidate genes, 24 genes showed effect in the upstream/downstream of the genic region and two genes showed effect in the genes. Validation of these 16 candidate Indels in other FW‐ and SMD‐resistant and FW‐ and SMD‐susceptible genotypes revealed a significant association of five Indels (three for FW and two for SMD resistance). Comparative analysis of Indel‐seq with other genetic mapping approaches highlighted the importance of the approach in identification of significant genomic regions associated with target traits. Therefore, the Indel‐seq approach can be used for quick and precise identification of candidate genomic regions for any target traits in any crop species.     

Supercritical fluid disruption of Ralstonia eutropha for poly(beta-hydroxybutyrate) recovery

A new method for disruption of Gram-negative bacterium Ralstonia eutropha by supercritical CO(2) for poly(beta-hydroxybutyrate) (PHB) recovery is proposed. The effects of different parameters such as exposure time, pressure, temperature, volume of methanol as a modifier, and culture history on cell disruption efficiency were investigated using Taguchi's statistical approach to determine optimum conditions. The optimum conditions for cell disruption and PHB recovery were as follows: exposure time, 100 min; pressure, 200 atm; temperature, 40 degrees C; volume of methanol, 0.2 mL. The cell culture time was less significant. At optimum conditions, the maximum efficiency of PHB recovery was found to be 89%. The proposed method is comparable with other recovery methods in terms of the percentage of PHB recovery, while it is environmentally more benign.     

Copper II complex of a tridentate ligand: an artificial metalloprotease for bovine serum albumin

A copper(II) complex of 2, 6-bis(benzimidazo-2-yl) pyridine was synthesized and its binding properties with bovine serum albumin (BSA) has been evaluated. The binding plot obtained from the absorption titration data gives a binding constant of 2.4 (+/-0.3) x10(3) M(-1). It was found that the charge transfer band of the metal complex was perturbed in the presence of BSA. The gel electrophoresis pattern of BSA incubated with copper(II) complex shows the metalloproteolytic activity of the metal complex. In the presence of oxygen, protein undergoes site-specific cleavage by binding to the histidine residues of domain III, with the resultant formation of four fragments of molecular weight 49, 45, 22 and 17 kDa. This indicates the presence of two specific binding sites in the protein molecule. In the absence of molecular oxygen, the metal complex was found unable to cleave the protein. The circular dichroism (CD) spectrum of the isolated fragments shows nearly 38% and 32% of alpha helical content in 49 and 45 kDa fragments, respectively, which shows that the cleavage leads to no changes in the secondary structure of the protein fragments.     

Extract of gum resins of Boswellia serrata L. inhibits lipopolysaccharide induced nitric oxide production in rat macrophages along with hypolipidemic property

Boswellia serrata, Linn F (Burseraceae) is commonly used in Indian system of medicine (Ayurvedic) as an anti-inflammatory, analgesic, anti-arthritic and anti-proliferative agent. This study was planned to investigate the water-soluble fraction of the oleoresin gum of Boswellia serrata (BS extract) on lipopolysaccharide (LPS) induced nitric oxide (NO) production by macrophages under in vivo and in vitro conditions. In the previous condition, rats were fed on atherogenic diet (2.5% cholesterol, 1% cholic acid, 15.7 % saturated fat) along with the BS extract for 90 days. Blood was collected for lipid profile and toxicological safety parameters. Peritoneal macrophages were isolated and cultured to see the LPS induced NO production. Under in vivo experiment, BS extract significantly reduced serum total cholesterol (38-48 %), increased serum high-density lipoprotein- cholesterol (HDL-cholesterol, 22-30%). Under in vitro experiments with thioglycolate activated macrophages, it inhibited LPS induced (NO) production with IC 50 value at 662 ng /ml. Further, this fraction, in the dose of 15 mg/100 g body wt for 90 days, did not show any increase in serum glutamate-pyruvate transaminase (SGPT) and blood urea, in normal control animals. However, it significantly reversed the raised SGPT and blood urea in the atherogenic diet-fed animals. Transverse section of liver and kidney also supported its protective effect. Thus it may be concluded that water extract of Boswellia serrata possesses strong hypocholesterolemic property along with increase in serum HDL. It inhibits the LPS induced NO production by the activated rat peritoneal macrophages and show hepato-protective and reno-protective property.     

DNA sequence alterations affect nucleosome array formation of the chicken ovalbumin gene

The role of the large amount (more than half of the genome) of noncoding DNA in higher organisms is not well understood. DNA evolved to function in the context of chromatin, and the possibility exists that some of the noncoding DNA serves to influence chromatin structure and function. In this age of genomics and bioinformatics, genomic DNA sequences are being searched for informational content beyond the known genetic code. The discovery that period-10 non-T, A/T, G (VWG) triplets are among the most abundant motifs in human genomic DNA suggests that they may serve some function in higher organisms. In this paper, we provide direct evidence that the regular oscillation of period-10 VWG that occurs in the chicken ovalbumin gene sequence with a dinucleosome-like period facilitates nucleosome array formation. Using a linker histone-dependent in vitro chromatin assembly system that spontaneously aligns nucleosomes into a physiological array, we show that nucleosomes tend to avoid DNA regions with low period-10 VWG counts. This avoidance leads to the formation of an array with a nucleosome repeat equal to half the period value of the oscillation in period-10 VWG, as determined by Fourier analysis. Two different half-period deletions in the wild-type DNA sequence altered the nucleosome array, as predicted computationally. In contrast, a full-period deletion had an insignificant effect on the nucleosome array formed, also consistent with the prediction. An inversion mutation, with no DNA sequences deleted, again altered the nucleosome array formed, as predicted computationally. Hence, a VWG dinucleosome signal is plausible.     

Effect of process variables on supercritical fluid disruption of Ralstonia eutropha cells for poly(R-hydroxybutyrate) recovery

This research focuses on the disruption of the gram-negative bacterium Ralstonia eutropha cells by supercritical CO2 for poly(R-hydroxybutyrate) (PHB) recovery. The variables affecting cell disruption such as drying strategy, type of modifier, and cultivation time, as well as operating pressure, temperature, and repeated release of supercritical CO2 pressure, have been studied. Effect of this disruption technique on PHB molecular mass was also investigated. PHB recovery was examined using a combination of this method and chemical pretreatments. For salt pretreatment, the cells were exposed to 140 mM NaCl and heat (60 degrees C, 1 h). The cells were also exposed to 0.2-0.8% (w/w) NaOH to examine the effect of alkaline pretreatment. Bacterial cells treated in growth phase exhibited less resistance to disruption than nutrient-limited cells in the stationary phase. It was also found that the wet cells could be utilized to recover PHB, but purity of the product was lower than that obtained from freeze-dried cells. Pretreatment with a minimum of 0.4% (w/w) NaOH was necessary to enable complete disruption with two times pressure release. Salt pretreatment was less effective; however, disruption was improved by the application of alkaline shock. The proposed method is economic and comparable with other recovery methods in terms of the percentage of PHB recovery and energy consumption, while it is environmentally more benign.     

Enhanced Hydrogen Storage in Graphene Oxide‐MWCNTs Composite at Room Temperature

High hydrogen capacity (up to 2.6 wt%) is reported for highly aligned structures of Graphene oxide‐Multiwalled carbon nanotubes composite at room temperature. It is demonstrated that the scalable liquid crystal route can be employed as a new method to prepare unique 3‐D framework of graphene oxide layers with proper interlayer spacing as building blocks for cost‐effective high‐capacity hydrogen storage media. The strong synergistic effect of the intercalation of MWCNTs as 1‐D spacers within graphene oxide frameworks resulted in unrivalled high hydrogen capacity at ambient temperature. The mechanisms involved in the intercalation procedure are fully discussed. The main concept behind intercalating one‐dimensional spacers in between giant GO sheets represents a versatile and highly scalable route to fabricate devices with superior hydrogen uptake.