187 research outputs found

    Effects of different packaging methods on microbial, [chemical] and sensory properties of Nile tilapia (Oreochromis niloticus Linnaeus, 1758) fillets during refrigerator storage

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    The effect of three different packaging methods including Modified Atmosphere Packaging (MAP), Vacuum Packaging and normal Packaging was investigated on the quality of Nile tilapia fresh fillets stored in the refrigerator's temperature. The packaged samples were examined for 10 days with regard to the changes in chemical (TVN, PV, pH), microbial (total viable count) and sensory evaluations. The results indicated that the samples packed in MAP condition had higher quality than that of other methods at the end of the storage period. In addition, the slower destructive impacts and microbial growth was observed in MAP. The results of present study suggest that packaging tilapia under MAP conditions results in the increase in the durability, storing, and distribution period for fillets

    Phosphopantetheinyl transferase (Ppt)-mediated biosynthesis of lysine, but not siderophores or DHN melanin, is required for virulence of Zymoseptoria tritici on wheat

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    Zymoseptoria tritici is the causal agent of Septoria tritici blotch (STB) disease of wheat. Z. tritici is an apoplastic fungal pathogen, which does not penetrate plant cells at any stage of infection, and has a long initial period of symptomless leaf colonisation. During this phase it is unclear to what extent the fungus can access host plant nutrients or communicate with plant cells. Several important primary and secondary metabolite pathways in fungi are regulated by the post-translational activator phosphopantetheinyl transferase (Ppt) which provides an essential co-factor for lysine biosynthesis and the activities of non-ribosomal peptide synthases (NRPS) and polyketide synthases (PKS). To investigate the relative importance of lysine biosynthesis, NRPS-based siderophore production and PKS-based DHN melanin biosynthesis, we generated deletion mutants of ZtPpt. The ?ZtPpt strains were auxotrophic for lysine and iron, non-melanised and non-pathogenic on wheat. Deletion of the three target genes likely affected by ZtPpt loss of function (Aar- lysine; Nrps1-siderophore and Pks1- melanin), highlighted that lysine auxotrophy was the main contributing factor for loss of virulence, with no reduction caused by loss of siderophore production or melanisation. This reveals Ppt, and the lysine biosynthesis pathway, as potential targets for fungicides effective against Z. tritici

    Direct haplotyping of bi-allelic SNPs using ARMS and RFLP analysis techniques

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    Haplotype analysis of single nucleotide polymorphisms (SNPs) is an important and rapidly growing approach for association studies. In recent years, statistical procedures to haplotype determination from genotypic information have employed in population studies. These procedures, even though some advantages for estimation of haplotype frequencies in large population samples, have limitations in the accuracy of the analysis. In this study, we have designed a reliable method for direct haplotyping of polymorphic sites using the amplification refractory mutation system (ARMS) and restriction fragment length polymorphism (RFLP) analysis techniques. We applied the method to determination of haplotypes composed of three SNPs within the paraoxonase1 gene promoter and found the approach can be used in many studies in population and in a variety of clinical settings. © 2007 Elsevier B.V. All rights reserved

    Effect of Glycine Betaine Nanocomposite Coated with Chitosan and Moderate Salinity Stress on In vitro Microtuberization of Potato (Solanum tuberosum L.) cv. Agria

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    Introduction Potato (Solanum tuberosum L.) is an important food and cash crop having the first rank in the world from non grain crops to ensure food security. The tubers produced through the conventional propagation are characterized by low multiplication rate and susceptibility to pathogens. Microtubers are an ideal propagating material for producing high quality seed potatoes. Nowadays, the production, application, and biological risk assessment of nano-scaled products have attracted global concerns in various fields such as agricultural, biotechnological, medicinal, and plant sciences. Chitosan, a biocompatible polymer, has been widely utilized to improve the production of nano-chemicals, thereby improving crop growth, productivity, and immunity. Nanotechnology plays an important role in modern agriculture to address global challenges such as climate change, severity of plant diseases and the limited availability of important plant nutrients. Polymer-based nano-formulations have recently received the greatest attention with the key objectives of developing less harmful, plant growth promoting and protective agents of biodegradable and natural origin. Use of chitosan-based nanoparticles in agriculture field is still in a budding phase. Significant outcomes have been reported in in vitro and a few in vivo studies in plant growth and protection by chitosan-based nanomaterials.   Materials and Methods MS medium containing 80 g of sucrose, containing glycine betaine at concentrations of 20 and 40 mg/l, chitosan at a concentration of 240 mg/l, glycine betaine 20 and chitosan 240 mg/l, glycine betaine 40 and chitosan 240 mg/l, 120 mg/l, glycine betaine nanocomposite coated with chitosan 120 and 240 mg/l and control treatment, as well as nonsalinity treatments with the same compounds and concentrations mentioned for salinity were cultured. The study was performed in randomized complete block design with three replications and sixteen treatment. Glycine betaine nanocomposite coated with chitosan were prepared at Maragheh University as follows. Chitosan, glycine betaine, and triphosphate are major consumables. First, chitosan was dissolved well with acetic acid under the influence of temperature. Then, a certain amount of glycine betaine was dissolved in distilled water and added to the chitosan. Tri-polyphosphate (TPP) was dissolved in distilled water at a certain volume ratio and added dropwise to the mixture of chitosan and glycine betaine. The precipitate obtained under the freeze-drying process lead to the preparation of its powder.     Results and Discussion According to the comparison of the means, treatment of glycine betaine coated with chitosan nanocomposite at a concentration of 120 mg/l produced the highest number of microtuber during the experiment from the first month to the final month. The nanocomposite was more capable of improving growth and biomass than the bare ZnONPs in pepper. The application of the nanocomposite increased the concentration of chlorophylls (51%), carotenoids (70%), proline (2-fold), and proteins (about 2- fold). The supplementation of culture medium with the nanomaterials upregulated enzymatic antioxidant biomarkers (catalase and peroxidase) (Asgari-targhi et al., 2021). The highest mean microtuber weight was related to the nanocomposite treatment of 120 mg/l with a weight of 29 mg. In the microtuber diameter, this treatment had the highest value. The results of analysis of variance in Table 1 indicate that the effect of moderate salinity and the interaction of moderate salinity and nanocomposite treatments are not significant and the effect of experimental treatments is significant at the level of 5% probability. Due to the fact that the most important trait in the potato microtuberization is microtuber yield, so in the experiment, the highest microtuber yield was earned nanocomposite treatment with 131 mg and the lowest in control treatment with 87 mg. It seems that by using stress-reducing compounds such as glycine betaine and chitosan and nanocomposites, these compounds increase the amount of genes responsible for the formation of microtuber, and as a result, increasing the proteins involved in stresses induce more microtuberization. Also, nanocomposite materials, more assimilated materials may be transferred from the roots to microtuberization processes.   Conclusion  The microtuber produced in the glycine betaine coated with chitosan nanocomposite treatment produced the highest number of microtubers in the first, second, third, and final months. In treatments with moderate salinity in the first, second, third and final months, the number of microtuber and eyes and sprouted microtubers had the highest amount compared to the treatment without moderate salinity. Also, plants treated with glycine betaine voated with chitosan nanocomposite in the microtuber trate showed a greater effect than chitosan and glycine betaine with chitosan. According to the findings of this study, it seems that the use of nanocomposite materials in increasing the microtuber and reducing the vegetative growth of potato shoots has been made in Agria cultivar

    Sengers syndrome: six novel AGK mutations in seven new families and review of the phenotypic and mutational spectrum of 29 patients

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    Background: Sengers syndrome is an autosomal recessive condition characterized by congenital cataract, hypertrophic cardiomyopathy, skeletal myopathy and lactic acidosis. Mutations in the acylglycerol kinase (AGK) gene have been recently described as the cause of Sengers syndrome in nine families. Methods: We investigated the clinical and molecular features of Sengers syndrome in seven new families; five families with the severe and two with the milder form. Results: Sequence analysis of AGK revealed compound heterozygous or homozygous predicted loss-of-function mutations in all affected individuals. A total of eight different disease alleles were identified, of which six were novel, homozygous c.523_524delAT (p.Ile175Tyrfs*2), c.424-1G > A (splice site), c.409C > T (p.Arg137*) and c.877 + 3G > T (splice site), and compound heterozygous c.871C > T (p.Gln291*) and c.1035dup (p.Ile346Tyrfs*39). All patients displayed perinatal or early-onset cardiomyopathy and cataract, clinical features pathognomonic for Sengers syndrome. Other common findings included blood lactic acidosis and tachydyspnoea while nystagmus, eosinophilia and cervical meningocele were documented in only either one or two cases. Deficiency of the adenine nucleotide translocator was found in heart and skeletal muscle biopsies from two patients associated with respiratory chain complex I deficiency. In contrast to previous findings, mitochondrial DNA content was normal in both tissues. Conclusion: We compare our findings to those in 21 previously reported AGK mutation-positive Sengers patients, confirming that Sengers syndrome is a clinically recognisable disorder of mitochondrial energy metabolism

    Human Uterine Wall Tension Trajectories and the Onset of Parturition

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    Uterine wall tension is thought to be an important determinant of the onset of labor in pregnant women. We characterize human uterine wall tension using ultrasound from the second trimester of pregnancy until parturition and compare preterm, term and twin pregnancies. A total of 320 pregnant women were followed from first antenatal visit to delivery during the period 2000–2004 at the John Hunter Hospital, NSW, Australia. The uterine wall thickness, length, anterior-posterior diameter and transverse diameter were determined by serial ultrasounds. Subjects were divided into three groups: women with singleton pregnancies and spontaneous labor onset, either preterm or term and women with twin pregnancies. Intrauterine pressure results from the literature were combined with our data to form trajectories for uterine wall thickness, volume and tension for each woman using the prolate ellipsoid method and the groups were compared at 20, 25 and 30 weeks gestation. Uterine wall tension followed an exponential curve, with results increasing throughout pregnancy with the site of maximum tension on the anterior wall. For those delivering preterm, uterine wall thickness was increased compared with term. For twin pregnancies intrauterine volume was increased compared to singletons (), but wall thickness was not. There was no evidence for increased tension in those delivering preterm or those with twin gestations. These data are not consistent with a role for high uterine wall tension as a causal factor in preterm spontaneous labor in singleton or twin gestations. It seems likely that hormonal differences in multiple gestations are responsible for increased rates of preterm birth in this group rather than increased tension

    Transcription Inhibition by DRB Potentiates Recombinational Repair of UV Lesions in Mammalian Cells

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    Homologous recombination (HR) is intricately associated with replication, transcription and DNA repair in all organisms studied. However, the interplay between all these processes occurring simultaneously on the same DNA molecule is still poorly understood. Here, we study the interplay between transcription and HR during ultraviolet light (UV)-induced DNA damage in mammalian cells. Our results show that inhibition of transcription with 5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole (DRB) increases the number of UV-induced DNA lesions (γH2AX, 53BP1 foci formation), which correlates with a decrease in the survival of wild type or nucleotide excision repair defective cells. Furthermore, we observe an increase in RAD51 foci formation, suggesting HR is triggered in response to an increase in UV-induced DSBs, while inhibiting transcription. Unexpectedly, we observe that DRB fails to sensitise HR defective cells to UV treatment. Thus, increased RAD51 foci formation correlates with increased cell death, suggesting the existence of a futile HR repair of UV-induced DSBs which is linked to transcription inhibition
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