The microassay of hyaluronic acid concentration and hyaluronidase activity by capillary turbidity (CT) and capillary turbidity reduction (CTR) tests

The Capillary Turbidity (CT) Test for quantitative estimation of hyaluronic acid concentrations in solutions is described. The standardized procedure permits assay of the visible reaction occurring between mucopolysaccharide and acidified albumin. The CT Test is reproducible, sensitive, simple, rapid, and economical in that it does not require the use of measuring instruments (e.g., spectrophotometer or viscosimeter) and is sparing of reagent materials. This test has led to the development of the Capillary Turbidity Reduction (CTR) Procedure for the semiquantitative microassay of hyaluronidase activity.     

Biotyping,virulotyping and biofilm formation ability of ESBL-Klebsiella pneumoniae isolates from nosocomial infections

The aim of this study was to investigate the frequency, molecular characterization, virulence genes, resistance genes and antimicrobial profile of nosocomial extended spectrum beta lactamase producing Klebsiella species. A total of 22 (12.2%) K. pneumoniae strains were isolated from 180 clinical samples collected from hospitalized patients in Egypt. K. pneumoniae biotypes were B1 (72.8%), B3 (13.6%) and B4 (13.6%). The isolates were classified for the capsular serotypes, 86.4% (20/22) were of K1 serotype, while only two isolates (13.64%) were of K2 serotype. Hypermucoviscous K. pneumoniae isolates accounted for 68.2%. Biofilm formation ability of K. pneumoniae was determined by microtitre plate method. The majority of the isolates (40.9%) were moderate biofilm producers, while 27.3% were strong biofilm producers. All K. pneumoniae strains were positive for fimH and traT genes, while magA was identified in only 63.6% of the isolates. The antibiotic susceptibility profile of the isolates (n = 22) was determined by the disc diffusion technique using 23 different antibiotics. Streptomycin and imipenem are the most effective antibiotics against 22 tested K. pneumoniae isolates with sensitivity rates of 63.64% and 54.54% respectively. All tested K. pneumoniae isolates showed high resistance to amoxicillin∕clavulanate (100%), cefuroxime (100%) and ceftazidime (95.45%). Extended spectrum beta lactamases (ESBL) production and the presence of ESBL-related genes were tested in the isolates. All the isolates tested positive for blaVIM, NDM1 and blaTEM, while only 81.8 %tested positive for the blaSHV gene. Increasing antimicrobial resistance in K. pneumoniae causing nosocomial infections limits the use of antimicrobial agents for treatment. Furthermore, the spread of biofilm, multiple drug resistant and ESBL-producing K. pneumoniae isolates is a public threat for hospitalized patients.     

Pyrolysis of Mixed Date Stones and Pistachio Shells: Identification of Bio-Oil and Utilization of Bio-Char as Activated Carbon Precursor

Thermal pyrolysis of mixed date stones and pistachio shells in a semi-batch reactor was addressed in this study. The highest yield of liquids (51.20 %) was produced at 500 °C, 90 min, 20 °C/min heating rate, and 50 mesh particle size. Under these conditions, yield of liquid from date stones and pistachio shells separately was 49.12 % and 47.67 %, respectively. The FT-IR results confirmed the presence of multiple oxygen-containing compounds in the bio-oil. Results from GC–MS declared that it was predominately composed of acids (57.57 %), esters (21.35 %), phenols (4.63 5), and alcohols (3.49 5). The obtained biochar was transformed into activated carbon (AC) by the optimized ZnCl₂ activation method. The ideal AC was synthesized at 600 °C for 60 min using a 2 : 1 ZnCl₂: biochar impregnation ratio. FESEM and XRD measurements showed that the AC was amorphous. The prepared AC was effective in eliminating dibenzothiophene (DBT) from model fuel (200 ppm DBT/hexane) with a maximum performance 95.26 % at 40 °C for 1h using 0.35 g of the AC. The exhausted AC was regenerated and reutilized 4 times, and removal efficiency reached 88.23 % in the 4^th cycle under ideal working conditions.     

Effect of hydrothermolysis process conditions on pretreated switchgrass composition and ethanol yield by SSF with Kluyveromyces marxianus IMB4

Hot compressed liquid water was used to treat switchgrass in a method called hydrothermolysis to disrupt lignin, dissolve hemicellulose, and increase accessibility of cellulose to cellulase. Three temperatures (190, 200, and 210 °C) and hold times (10, 15, and 20 min) were tested. Switchgrass treated at 190 °C for 10 min had the greatest xylan recovery in the prehydrolyzate. Less than 0.65 g/L glucose were released into the prehydrolyzate for all pretreatment conditions, indicating most glucose was retained as cellulose in the solid substrate. 5-Hydroxymethylfurfural (HMF) and furfural formation in the prehydrolyzate were found to be less than 1 g/L for all treatments. The highest concentration of ethanol, 16.8 g/L (72% of theoretical), was produced from switchgrass pretreated at 210 °C and 15 min using simultaneous saccharification and fermentation (SSF) at 45 °C with the thermotolerant yeast Kluyveromyces marxianus IMB4 and 15 FPU cellulase/g glucan.     

Yeheb (<Emphasis Type="Italic">Cordeauxia</Emphasis><Emphasis Type="Italic">edulis</Emphasis>) extract deters feeding and oviposition of <Emphasis Type="Italic">Plutella xylostella</Emphasis> and attracts its natural enemy

The effects of yeheb (Cordeauxia edulis Hemsl.) leaf extract on feeding and oviposition by diamondback moth (DBM) (Plutella xylostella L.) and the behavior of DBM parasitoid, Cotesia vestalis (Haliday), were studied. Volatile organic compounds (VOCs) from the headspace of intact and DBM-damaged broccoli plants sprayed with yeheb extracts (YE) were also analyzed. Larval feeding and growth, and oviposition by adult DBM were strongly inhibited by the extract. Cotesia vestalis were attracted to volatile blends from intact or DBM-damaged broccoli plants sprayed with YE over intact plants sprayed with water or methanol. Analyses of VOCs in the headspace of broccoli plants revealed that both intact and DBM-damaged plants sprayed with YE showed remarkable differences in sesquiterpene compounds compared to intact control treatments. These combined negative effects of YE on DBM fitness together with positive effects on the parasitoid show that yeheb is a potential source of compounds for use in integrated pest management to control damage caused by DBM.     

Plasma Reflectarrays

This paper investigates the design of four different configurations of plasma reflectarrays. The results provide insight into different radiation characteristics of plasma reflectarrays. The proposed unit cell consists of a cubic glass box filled with argon gas energized with applied AC voltage. The reflectarray reflection coefficient phase variation is achieved by varying the plasma frequency of the energized gas. Four plasma reflectarrays for satellite applications at 12 GHz are proposed (centre feed centre beam, centre feed offset beam, offset feed centre beam, and finally, offset feed offset beam). The finite integration technique is used to analyse the plasma reflectarray.     

Effects of immunomodulatory drugs on plasma inflammatory markers in a rabbit model of atherosclerosis

Atherosclerosis is a chronic disease of the arterial wall where both innate and adaptive immuno-inflammatory mechanisms are involved. Inflammatory cytokines are implicated in the development and progression of atherosclerotic lesions. Immunomodulatory therapies have been proposed for the treatment of atherosclerosis. Therefore, the aim of this study was to investigate the systemic anti-inflammatory and immunomodulatory effects of atorvastatin, cyclosporine A (CsA), and tacrolimus (FK506) on plasma inflammatory markers in atherosclerotic rabbits. Male New Zealand rabbits were randomized into five groups each of 12 animals. Standard diet-fed group served as control, and the cholesterol-fed group received a diet supplemented with 1% cholesterol alone, cholesterol + atorvastatin, cholesterol + FK506, and cholesterol + CsA. Serum levels of lipid profile parameters (triglycerides, cholesterol, and high-density lipoprotein) were measured using colorimetric methods. Serum levels of C-reactive protein (CRP), interleukin-6 (Il-6), and interferon-gamma (INF-γ) were measured in all studied groups using ELISA techniques. Our results revealed a significant decrease (p < 0.001) in the serum levels of lipid profile parameters, CRP, Il-6, and INF-γ in atorvastatin-treated group compared with the cholesterol-fed group. On the other hand, a non-significant difference was observed for the same parameters in either FK506- or CsA-treated groups compared with the cholesterol-fed group. In conclusion, atorvastatin has a systemic anti-inflammatory role that far surpassed the cholesterol reduction effect alone. FK506 or CsA failed to suppress elevated plasma inflammatory markers. Thus, low doses of these two immunomodulating drugs could not have generalized systemic anti-inflammatory or immunosuppressive effects.     

Analysis of the mechanism by which tryptophan analogs inhibit human myeloperoxidase

Myeloperoxidase (MPO) catalyzes the formation of oxidants that have been implicated in the pathogenesis of various diseases, including cardiovascular and pulmonary diseases and cancer. Inhibition of MPO oxidant-generating activity represents an attractive target for preventing the progression of inflammatory conditions. Peroxidation and chlorination catalytic activity were utilized to screen for the most effective tryptophan analog that inhibits MPO. Rapid kinetic measurements were performed to determine the mechanisms through which these compounds inhibit the catalytic activity of MPO. Substituents on the amino and carboxyl termini of tryptophan enhance its affinity toward MPO compared to a substituent on the indole ring. Hydrogen-bond donor capabilities and a positive charge on the amino group are not required for MPO inhibition. Hydroxyl-containing indoles did not inhibit MPO H₂O₂-consumption activity. Elimination of the negative charge from the carboxyl terminus by introducing a hydrophobic character significantly enhanced tryptophan analog affinity for MPO and improved its inhibitory properties. Further mechanistic studies indicated that indole compounds inhibited MPO activity through the accumulation of compound II, an inactive MPO intermediate. Our results show that specific structural features of tryptophan analogs are involved in increasing the affinity for MPO and providing a significantly greater inhibition of MPO's catalytic activities.     

Polymeric surfactant based etodolac chewable tablets: formulation and in vivo evaluation

Etodolac (ET) is a nonsteroidal anti-inflammatory drug with proved potential antitumor and uric acid lowering effects. It shows dissolution rate-dependent bioavailability. This work was carried out to improve the dissolution rate of etodolac using three carriers of known potential to improve solubility and hence dissolution rate of poorly soluble drugs through coevaporation technique. The polymeric surfactant inutec, 2-hydroxypropyl-β-cyclodextrin, and tromethamine were used at three different drug/carrier ratios. The dissolution rate of ET at pH 1.2 and 6.8 is improved in all of the solid dispersion systems compared to that of the pure drug and physical mixtures. DSC of coevaporates at 1:5 drug/carrier ratio providing the fastest dissolution rate suggested loss of ET crystallinity which was further confirmed by X-ray diffraction. Inutec-based coevaporate was chosen for the formulation of ET chewable tablets. Chewable tablets (F3) that met the USP monograph specifications for ET tablets, with 86% dissolved amount within 15 min, was chosen for in vivo absorption study in comparison with pure ET-filled hard gelatin capsules. The results showed significantly higher mean C _max and shorter mean T _max (about 2 h earlier) and about 1.32-fold higher mean AUC_0–24 values for the F3 chewable tablets compared to ET-filled capsules.