High inhabitation activity of CMCS/Phytic acid/Zn2+ nanoparticles via flash nanoprecipitation (FNP) for bacterial and fungal infections.

Plant diseases prompted by fungi and bacteria are one of the most serious threats to global crop production and food security. The destruction of these infections posed a major challenge to plant protection by chemical control. Herein, we develop CMCS/PA/Zn2+ nanoparticles (NPs) using carboxymethyl chitosan (CMCS), phytic acid (PA) and metal ions (Zn2+) via flash nanoprecipitation (FNP) strategy. Metal complexes of PA with specified antibacterial and antifungal activities are expected to hold the potential and play a significant role in antimicrobial treatment. The size and size distribution of NPs was confirmed through Dynamic and Static Light Scatterer (DSLS). In acidic-infection microenvironment, the CMCS/PA/Zn2+ NPs can disintegrate and release Zn2+ in situ thus stimulated the corresponding antimicrobial activity. These CMCS/PA/Zn2+ NPs showed outstanding antibacterial efficacy (98 %) against S. aureus and E. coli bacteria in vitro, as well as an impressive antifungal efficacy of 98 % and 81 % against R. solani and B. cinerea at 50 µg/mL respectively. This study contributes a prospective idea to the development of organic-inorganic hybrid NPs as environmentally-friendly and safe agricultural antimicrobials.

Partial epilepsy with antecedent febrile seizures and seizure aggravation by antiepileptic drugs: associated with loss of function of Na(v) 1.1.

PURPOSE: Generalized epilepsy with febrile seizures plus (GEFS+) and severe myoclonic epilepsy in infancy (SMEI) are associated with sodium channel α-subunit type-1 gene (SCN1A) mutations. Febrile seizures and partial seizures occur in both GEFS+ and SMEI; sporadic onset and seizure aggravation by antiepileptic drugs (AEDs) are features of SMEI. We thus searched gene mutations in isolated cases of partial epilepsy with antecedent FS (PEFS+) that showed seizure aggravations by AEDs. METHODS: Genomic DNA from four patients was screened for mutations in SCN1A, SCN2A, SCN1B, and GABRG2 using denaturing high-performance liquid chromatography (dHPLC) and sequencing. Whole-cell patch clamp analysis was used to characterize biophysical properties of two newly defined mutants of Na(v) 1.1 in tsA201 cells. RESULTS: Two heterozygous de novo mutations of SCN1A (R946H and F1765L) were detected, which were proven to cause loss of function of Na(v) 1.1. When the functional defects of mutants reported previously are compared, it is found that all mutants from PEFS+ have features of loss of function, whereas GEFS+ shows mild dysfunction excluding loss of function, coincident with mild clinical manifestations. PEFS+ is similar to SMEI clinically with possible AED-induced seizure aggravation and biophysiologically with features of loss of function, and different from SMEI by missense mutation without changes in hydrophobicity or polarity of the residues. CONCLUSIONS: Isolated milder PEFS+ may associate with SCN1A mutations and loss of function of Na(v) 1.1, which may be the basis of seizure aggravation by sodium channel-blocking AEDs. This study characterized phenotypes biologically, which may be helpful in understanding the pathophysiologic basis, and further in management of the disease.

Schistosoma japonicum: construction of phage display antibody library and its application in the immunodiagnosis of infection.

BACKGROUND: A monoclonal antibody would be an effective tool for the detection of circulating antigens in the serum of patients with schistosomiasis, but the traditional way of producing monoclonal antibodies is not cost-effective. The objective of this study was to find a new method for the large-scale production of monoclonal antibodies against Schistosoma japonicum (Sj). METHODS: A phage display antibody library for Sj was constructed. To obtain a single-chain variable fragment antibody (scFv) against Sj, the library was screened with metabolic antigens from adult Sj worms (Sj-MAg) using enzyme-linked immunosorbent assay. The soluble scFvs selected were used to detect Sj antigens in the serum of acute and chronic schistosomiasis patients. RESULTS: Six positive clones with good reactivity to Sj-MAg were obtained from the phage display antibody library of about 1.07 x 10(6) individual clones. Only two of these six clones bound specifically to Sj-MAg and were chosen for further analysis. Specific soluble anti-Sj-MAg scFvs were produced by inducing the 2 clones with isopropyl-D-thiogalactopyranoside. The characteristics of the scFvs were then determined. The results of Western blot showed that these scFvs could bind to Sj-MAg specifically and had a molecular weight of about 31 kD. When testing serum from schistosomiasis patients with one of the two specific scFvs, its sensitivity was found to be 60% and 37% in acute and chronic patients, respectively, with a specificity of 90%. When the two specific scFvs were combined, their sensitivity was found to be 75% and 57% in acute and chronic patients, respectively, with a specificity of 85%. CONCLUSIONS: The results indicate that the scFvs are potentially useful for the diagnosis of schistosomiasis. The library construction also provides a useful tool for the further screening of other antibodies for both diagnostic and immunotherapeutic applications and for epitope analysis and vaccine design.

[Screening and identification of phage antibodies from phage display library against Schistosoma japonicum].

OBJECTIVE: To obtain single chain variable fragment(ScFv) against the circulating antigen(CAg) from Schistosoma japonicum(Sj). METHODS: Metabolic antigen of adult worm of Sj (Sj-MAg) was used in the panning of phage library against Schistosoma japonicum. The activity of Sj-MAg-binding phage clones was assayed by ELISA. The specificity of expression products of the positive clones was analyzed by ELISA, SDS-PAGE and Western blotting. RESULTS: Seventy-two randomly selected clones were tested for the presence of anti-Sj-MAg ScFvs, 6 clones showed positive. The specificity of these 6 clones was confirmed by binding them to antigens of other four trematodes. Two clones (B04, C24) were found to bind to Sj-MAg but not to any of the antigens of other four trematodes and their expression products were about 31 kDa in size. CONCLUSION: ScFv antibodies against the circulating antigens from Schistosoma japonicum Sj-MAg can be selected and manufactured from the antibody library.