Natural occurrence of ochratoxin A and citrinin in food stuffs in Egypt

Natural occurrence of ochratoxin A (OA) and citrinin in cereals (274 samples) and animal tissues (250 samples) have been investigated during a period of more than 2 years. OA was found in cereals and animal tissues while citrinin was found in cereals only. The highest level of OA (up to 80.0 μg/kg) was found in yellow corn, 52.8% of contaminated samples while respectively 55.9% and 39.4% of barley and rice samples were contaminated with citrinin, with the highest level up to 100.0 and 27.92 μg/kg for barley and rice respectively. The frequent contamination of animal kidney with OA (28% positive out of 150 tested) average concentration 12.33 μg/kg. 2% of liver and 4% of muscles tissue were observed.     

Essential Oil of Deverra tortuosa Aerial Parts: Detailed Chemical Profile,Allelopathic, Antimicrobial,and Antioxidant Activities

Essential oils (EOs) are a promising group of natural products of the aromatic plants due to their various biological effects such as allelopathic, antioxidant, antimicrobial activities. The present study aimed to construct the detailed chemical profile of the EO derived from Deverra tortuosa aerial parts along with assessing its allelopathic, antimicrobial, and antioxidant potentialities. The EO was extracted by hydrodistillation and analyzed via gas chromatography-mass spectrometry (GC/MS). The allelopathic activity of the EO was assessed against the germination and seedling growth of the weed Chenopodium murale. Also, the EO was tested against five microbes. The antioxidant activity was determined using the free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS). The GC/MS analysis of EO revealed the presence of 86 compounds with a preponderance of oxygenated sesquiterpenes and monoterpene hydrocarbons. Widdrol, β-phellandrene, piperitol, cubedol, α-terpinene, (E)-10-heptadecen-8-ynoic acid methyl ester, citronellyl tiglate, and m-cymene were the major compounds. A comparative profile was established between the EOs constituents of our study with the documented EOs of D. tortuosa and the other Deverra species around the world via agglomerative hierarchical clustering (AHC) and principal components analysis (PCA). The EO showed a substantial allelopathic activity against C. murale, as well as it showed considerable antimicrobial and antioxidant activities. Thereby, the EO of D. tortuosa could be considered as a promising environmental-friendly bioherbicide against weeds. Also, it could be integrated into food preservation due to its potent antimicrobial and antioxidant activities. However, further study is recommended for more characterization of the major compounds and evaluation of their activities, either singular or synergistic, and assess their efficiency and biosafety.     

Cellulase Enzyme from Aspergillus niger

Cellulase enzyme was produced by a selected strain of Aspergillus niger isolated from deteriorated wood and grown on different carbon sources. Filter paper gave the highest yield, followed by carboxymethyl cellulose (CMC). Cellobiose as well as glucose gave a low yield, while the yield from lactose was negligible. The concentration of filter paper cellulose that induced the maximum yield of the enzyme was 1%. Both soluble cellulose (CMC) and cotton cellulose treated with phosphoric acid (swollen) were easily hydrolyzed by cellulase; an increase in cellulase concentration lead to more hydrolysis of CMC and gave linearity in the reaction velocity. At certain concentrations of the enzyme, increase in CMC concentration, (up to 1%) resulted in more reducing sugar. Beyond this point no more hydrolysis occur.     

Streptomyces alni as a biocontrol agent to root-rot of grapevine and increasing their efficiency by biofertilisers inocula

Root-rotted samples of grapevine cv. superior were collected from Nobaria province, Beheira Governorate, Egypt. Fusarium oxysporum Schlech. was the most fungal causing root-rot syndrome of grapevine and directly affected the yield productivity. Seven isolates of Streptomyces were isolated from grapevine rhizospheric soil and screened for antagonistic activities against F. oxysporum on dual culture plate. All isolates showed antifungal activity, but isolate No. 1 exhibited the highest activity. It was identified as Streptomyces alni according to morphological, cultural, physiological and biochemical studies. The properties of the antagonism were revealed by scanning electron microscopy (SEM) examination of F. oxysporum and S. alni on PDA medium. The forms of antagonism found in this study according to the interaction between the S. alni and the pathogen indicated a hyperparasite, including inhibition of fungal growth and colonisation of S. alni over F. oxysporum hyphae. Also, malformation and lysis of F. oxysporum hyphae and conidiophores were observed. Conidia and normal branches of fungal hyphae were absent. Greenhouse and field studies were performed to evaluate the ability of S. alni and some commercial biofertilisers incorporated into the soil for root-rot control. Pot trails indicated that antagonistic S. alni isolate and biofertilisers i.e. blue green algae, phosphoren and rhizobacterin reduced the root-rot incidence of grapevine plants Cv. superior. Soil treatment before sowing with 50 ml of S. alni suspension (1 × 10⁸ spore/ml) + 50 g of rhizobacterin for each pot was the best and significant treatment reduced root-rot of grapevine plants. Also, the total count of F. oxysporum in rhizosphere soil of grapevine treated plants was reduced compared with control. Under field conditions, drenching soil of diseased grape trees with a spore suspension of S. alni (1 × 10⁸ spore/ml) 200 ml/tree + 250 g/tree of rhizobacterien caused a significant reduction in root rot of treated grapevine trees as well as high fruit yield/tree when compared with other treatments. The obtained results suggest that S. alni could be used successfully in combination with biofertilisers, as environmentally safe, for controlling root-rot of grapevine and other soil-borne plant pathogens especially with organic farming systems.     

Evaluation of three molecular methods of repetitive element loci for differentiation of <Emphasis Type="Italic">Mycobacterium avium</Emphasis> subsp. <Emphasis Type="Italic">paratuberculosis</Emphasis> (MAP)

The aim of the present study is to evaluate the efficiency of three methods to determine the molecular diversity of 34 Mycobacterium avium subsp. paratuberculosis (MAP) strains isolated from 17 cattle herds. The applied methods included the analysis of sequence polymorphism of the mononucleotide (G1 and G2) and trinucleotide sequences (GGT) of the Short Sequence Repeats (SSR) and the determination of size polymorphism of 9 different Mycobacterial Interspersed Repetitive Units (MIRU) and 6 Variable Number Tandem Repeats (VNTR). Sequence analysis of SSR of 34 isolates showed 4, 6, and 2 alleles of G1, G2, and GGT repeats, respectively. The amplification of the investigated 9 MIRU units revealed only two discriminatory genotyping systems (MIRU2 and MIRU3). Out of 6 VNTR PCR differentiation methods, only one method could be recommended for genotyping purposes. The profile 7g-12g-4ggt-II-b-2 of the combination systems G1-G2-GGT-MIRU2-MIRU3-VNTR1658 dominates among the examined isolates and was detected in 14.7% of the isolates. The use of certain repetitive loci of SSR, MIRU, and VNTR techniques in this study showed greater potential than others for the characterization of MAP isolates. The recommended loci can be used for the epidemiological tracing of MAP field strains and to determine the relationships between isolates in different herds.     

Targeting methionyl tRNA synthetase: design,synthesis and antibacterial activity against Clostridium difficile of novel 3-biaryl-N-benzylpropan-1-amine derivatives

The synthesis of a series of benzimidazole-N-benzylpropan-1-amines and adenine-N-benzylpropan-1-amines is described. Subsequent evaluation against two strains of the anaerobic bacterium Clostridium difficile was performed with three amine derivatives displaying MIC values of 16?μg/mL. Molecular docking studies of the described amines determined that the amines interact within two active site pockets of C. difficile methionyl tRNA synthetase with methoxy substituents in the benzyl ring and an adenine biaryl moiety resulting in optimal binding interactions.     

Feasibility of breast conservation after neoadjuvant taxene based chemotherapy in locally advanced breast cancer: a Prospective Phase I trial

Background

Acute cholecystitis can be the result of retention of bile in the gallbladder with possible secondary infection and ischaemia. The aim of the present study was to investigate whether internal drainage of the gallbladder could protect against the development of acute cholecystitis in a pig model.

Materials and methods

Twenty pigs were randomized to either internal drainage (drained) or not (undrained). Day 0 acute cholecystitis was induced by ligation of the cystic artery and duct together with inoculation of bacteria. Four days later the pigs were killed and the gallbladders were removed and histologically scored for the presence of cholecystitis. Bile and blood samples were collected for bacterial culturing and biochemical analyses.

Results

The histological examination demonstrated statistical significant differences in acute cholecystitis development between groups, the degree of inflammation being highest in undrained pigs. There were no differences in bacterial cultures between the two groups.

Conclusion

Internal drainage of the gallbladder protected against the development of acute cholecystitis in the present pig model. These findings support the theory that gallstone impaction of the cystic duct plays a crucial role as a pathogenetic mechanism in the development of acute cholecystitis and suggest that internal drainage may be a way to prevent and treat acute cholecystitis.     

pH-responsive poly(styrene-alt-maleic anhydride) alkylamide copolymers for intracellular drug delivery

Many macromolecular therapeutics such as peptides, proteins, antisense oligodeoxynucleotides (ASODN), and short interfering RNA (siRNA) are active only in the cytoplasm or nucleus of targeted cells. Endocytosis is the primary route for cellular uptake of these molecules, which results in their accumulation in the endosomal-lysosomal trafficking pathway and loss of therapeutic activity. In this article, we describe the synthesis and pH-dependent membrane-destabilizing activity of a new "smart" polymer family that can be utilized to enhance the intracellular delivery of therapeutic macromolecules through the endosomal membrane barrier into the cytoplasm of targeted cells. These polymers are propylamine, butylamine, and pentylamine derivatives of poly(styrene-alt-maleic anhydride) (PSMA) copolymers. The PSMA-alkylamide derivatives are hydrophilic and membrane-inactive at physiological pH; however, they become hydrophobic and membrane-disruptive in response to endosomal pH values as measured by their hemolytic activity. Results show that the pH-dependent membrane-destabilizing activity of PSMA derivatives can be controlled by varying the length of the alkylamine group, the degree of modification of the copolymer, and the molecular weight of the PSMA copolymer backbone. Butylamine and pentylamine derivatives of PSMA copolymers exhibited more than 80% hemolysis at endosomal pH values, which suggests their potential as a platform of "smart" polymeric carriers for enhanced cytoplasmic delivery of a variety of therapeutic macromolecules.     

Growth and fragmentation of silver nanoparticles in their synthesis with a fs laser and CW light by photo-sensitization with benzophenone.

The photo-sensitization synthetic technique of making silver nanoparticles using benzophenone is studied using both a laser and a mercury lamp as light sources. The power and irradiation time dependence of the synthesized nanoparticle absorption spectra and their size distribution [as determined by transmission electron microscopy (TEM)] are studied in each method and compared. In the laser synthesis, as either the laser power or the irradiation time increases, the intensity of the surface plasmon resonance absorption at 400 nm is found to increase linearly first, followed by a reduction of the red edge of the plasmon resonance absorption band. The TEM results showed that in the laser synthesis low powers and short irradiation times produce nanoparticles around 20 nm in diameter. Increasing the power or irradiation time produces a second population of nanoparticles with average size of 5 nm in diameter. These small particles are believed to be formed from the surface ablation of the large particles. The surface plasmon absorption band is found to be narrower when the nanoparticles are produced with laser irradiation. Throughout the exposure time with the CW lamp, the plasmon resonance absorption band of the particles formed first grows in intensity, then blue shifts and narrows, and finally red shifts while decreasing in intensity. The TEM results for lamp samples showed particle formation and growth, followed by small nanoparticle formation. The above results are discussed in terms of a mechanism in which, the excited benzophenone forms the ketal radical, which reduces Ag+ in solution and on the Ag nanoparticle surface. As the time of irradiation or the light energy increases the benzophenone is consumed, which is found to be the limiting reagent. This stops the formation of the normal large nanoparticles while their photo-ablation continues to make the small particles.     

Anti-proliferative and antioxidant constituents from Tecoma stans

Phytochemical investigation of Tecoma stans Juss. fruits and flowers resulted in the isolation of a new phenylethanoid, 2-(3,4-dihydroxyphenyl)ethyl-2-O-[6-deoxy-alpha-L-mannopyranosyl-4-(3,4-dihydroxyphenyl)-2-propenoate]-beta-D-glucopyranoside (3), and a novel monoterpene alkaloid, 5-hydroxy-skytanthine hydrochloride (8), along with eleven known compounds; 4-O-E-caffeoyl-alpha-L-rhamnopyranosyl-(1' --> 3)-alpha/beta-D-glucopyranose (1), E/Z-acetoside (2), isoacetoside (4), rutin (5), luteolin 7-O-beta-D-neohespridoside (6), luteolin 7-O-beta-D-glucopyranoside (7) and sucrose (9) were isolated from the fruits, while luteolin 7-O-beta-D-glucuronopyranoside (10), diosmetin 7-O-beta-D-glucuronopyranoside (11), diosmetin 7-O-beta-D-glucopyranoside (12), diosmetin 7-O-beta-D-glucuronopyranoside methyl ester (13) and acetoside (2) were isolated from the flowers. Their chemical structures have been determined on the basis of chemical and spectroscopic evidences. Biological investigations of a T. stans fruits extract and compounds 1, 2, 4, and 8 indicated that the extract, 1, 2, and 4 possessed a strong scavenging activity to DPPH, peroxyl and hydroxyl radicals. Unlike 4, which potentially induced NO generation in bacterial lipopolysaccharide-stimulated raw murine macrophage (RAW 264.7), the extract, 1, 2, and 8 significantly inhibited the NO generation. The extract, 2 and 4 exhibited a cytotoxic effect on human hepatocarcinoma cells (Hep-G2), while the extract, 2 and 8 were potent growth inhibitors of human breast carcinoma cells (MCF-7). 1 and 2 were remarkable growth inducers of human lymphoblastic leukemia cells (1301), whereas the extract, 2, and 8 stimulated the macrophage proliferation rate. Taken together, the novel compound 8 is effective as anti-proliferative agent against MCF-7 cells and as NO inhibitor, whereas 2 exhibited multi-functional properties as antioxidant and anti-proliferative agent against both solid tumor cell lines Hep-G2 and MCF-7 cells.