Search

Prion diseases are a group of infectious diseases that cause lethal neurodegenerative disorders in both humans and animals. Affected patients usually die within one year from the appearance of the first clinical abnormalities. Unfortunately, no viable treatment options are available for prion diseases. The aim of this review is to describe the underlying prion disease pathology and discuss the therapeutic targets that have emerged from this. [ABSTRACT FROM AUTHOR]

The article presents a study that determines the susceptibility of the pea aphid Acyrthosiphon pisum to a selected novel biorational insecticides. The study is conducted through the comparison of flonicamid with another feeding blocker, pymetrozine, and the neonicotinoid, imadacloprid. Results of the study show that halofenozide is less potent in terms of toxicity and concludes that improved aphid feeding apparatus can be useful to serve as a miniature screening device for insecticides.

Transgenic tobacco plants expressing the Allium porrum L. (leek) agglutinin (called APA) under the control of the 35S constitutive promoter were tested for their insecticidal activity against the cotton leafworm, Spodoptera littoralis (Lepidoptera: Noctuidae). Southern blot and PCR analysis confirmed that the APA gene was integrated into the plant genome. Northern and Western blots as well as semi-quantitative agglutination assays revealed lectin expression at various levels in the transgenic lines. Biochemical analyses indicated that the recombinant APA has the same molecular structure as the native lectin. Native and recombinant lectin have the same N-terminal amino acid sequence. Bioassays using detached leaves from transgenic tobacco plants demonstrated that the ectopically expressed APA significantly (p < 0.05) reduced the weight gain of 2nd-instar larvae of S. littoralis. This inhibitory effect was observed throughout the experiment and on day 11 the caterpillars fed on transgenic tobacco leaves were 25-30% lighter in weight than the control caterpillars fed on wild type plants. In addition the lectin retarded the development of the larvae and metamorphosis, reduced pupal weight and increased mortality rate. These findings suggest that APA is a suitable insect resistance protein for integrating into plant genomes for controlling S. littoralis. [ABSTRACT FROM AUTHOR]

The snowdrop lectin GNA ( Galanthus nivalis agglutinin) has been shown to possess insecticidal activity to a range of economically important insect pests. However, the precise mechanism of insecticidal action of GNA against insects remains unknown. In this investigation, we attempted to purify and identify receptor(s) responsible for binding of GNA in the larval midgut of a major lepidopteran pest (the cotton leafworm, Spodoptera littoralis) to better understand its mode of action. Therefore, cytoplasmic as well as membrane proteins from 800 larval midguts were chromatographed on a column with immobilized GNA. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of the proteins eluted from the GNA column followed by sequencing of the GNA-binding proteins and BLAST analyses revealed that the N-terminal sequences of a 24 kDa polypeptide purified from the cytoplasmic and membrane protein fraction revealed sequence similarity to sequences encoding heavy chain homologs of ferritin from Manduca sexta (76% sequence identity), Calpodes ethlius (80% sequence identity) and Bombyx mori (61% sequence identity). Furthermore, the N-terminal sequence of a 31 kDa polypeptide from the membrane protein fraction showed sequence similarity to a light chain homolog of ferritin from Manduca sexta (88% sequence identity). [ABSTRACT FROM AUTHOR]

The article discusses a comparative study on the insecticidal activities of two garlic lectins with different biological activities to check for correlation between the insecticidal properties and the specificity of lectins. The authors looked into the insecticidal activity of the garlic leaf lectin ASAL and bulb lectin ASAII in tobacco aphid Myzus nicotianae Blackmail with the use of bioassays with transgenic tobacco. They found out that bioassays with tobacco plants that showed ASAL and ASAII demonstrated an important impact on the population growth of M. nicotianae. It was also reported that both lectins can be viewed as valuable candidates for aphid control agents.

Objective: Poly(ε-caprolactone) (PCL) has considerable mechanical and biological properties that make it a good candidate for tissue engineering applications. PCL alongside proteins and polysaccharides, like gelatin (GEL) and chondroitin sulphate (CS), can be used to fabricate composite scaffolds that provide mechanical and biological requirements for skin tissue engineering scaffolds. The aim of this study was fabricating novel composite nanofibrous scaffold containing various ratios of GEL/CS and PCL using co-electrospinning process. Materials and Methods: In this experimental study, PCL mixed with a GEL/CS blend has limitations in miscibility and the lack of a common solvent. Here, we electrospun PCL and GEL/CS coincide separately on the same drum by using different nozzles to create composite nanofibrous scaffolds with different ratios (2:1, 1:1 and 1:2) of GEL to CSPCL, and we mixed them at the micro/nanoscale. Morphology, porosity, phosphate-buffered saline (PBS) absorption, chemical structure, mechanical property and in vitro bioactivity of the prepared composite scaffolds were analysed. Results: Scanning electron microscopy (SEM) images showed beadless nanofibres at all ratios of GEL to CS-PCL. The composite scaffolds (2:1, 1:1 and 1:2) had increased porosity compared to the PCL nanofibrous scaffolds, in addition to a significant increase in PBS absorption. The mechanical properties of the composite scaffolds were investigated under different conditions. The results demonstrated that all of the composite specimens had better strength when compared with the GEL/CS nanofibres. The increase in PCL ratio led to an increase in tensile strength of the nanofibres. Human dermal fibroblasts (HDF) were cultured on the fabricated composite scaffolds and evaluated by 3-(4,5-dimethylthiazol2-yl)-5-(3 carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) analysis and SEM. The results showed the bioactivity of these nanofibres and the potential for these scaffolds to be used for skin tissue engineering applications. Conclusion: The fabricated co-electrospun composite scaffolds had higher porosity and PBS absorption in comparison with the PCL nanofibrous scaffolds, in addition to significant improvements in mechanical properties under wet and dry conditions compared to the GEL/CS scaffold. [ABSTRACT FROM AUTHOR]

Aim: This study aims to determine the serogroup distribution and molecular diagnosis, as well as antimicrobial resistance profiles among Shigella spp. isolated from patients with diarrhea in Kerman, southeast of Iran., Background: Shigella species are frequent cause of bacterial dysentery worldwide. Previous studies have been reported that S. sonnei and S. flexneri are the most prevalent serogroups in various parts of Iran., Patients and Methods: A total of 624 stool samples were randomly collected from patients with diarrhea from June 2013 to August 2014. Biochemical and serological characterizations were performed for identifying Shigella spp. In addition, the multiplex PCR assay was carried out for the detection and differentiation of three pathogenic Shigella spp. Antibiotic susceptibility testing was performed according to the Clinical Laboratory Standards Institute (CLSI) guidelines., Results: Fifty six (9%) Shigella strains were isolated from stool samples. The most common species were S. flexneri 31(55.4%), followed by S . sonnei 18(32.1%) and S. boydii 7(12.5%). S. dysentery was not detected in the present study. All the isolates that identified by serological test as Shigella spp. were confirmed by the multiplex PCR method. The highest rate of resistance was observed for ampicillin and trimethoprim-sulphamethoxazole antibiotics with 52(92.9%) resistant, followed by tetracycline 44(78.6%) and cefotaxime 33(58.9%). All Shigella isolates were susceptible to ciprofloxacin. A significant relationship was found between the Shigella species and cefotaxime resistance (p<0.05)., Conclusion: S. flexneri was found as the most prevalent serogroup causing shigellosis. The high rate of resistance to third-generation cephalosporins limits the treatment options available for the management of shigellosis in Kerman, Iran.