Formulation and evaluation of silver nanoparticles as antibacterial and antifungal agents with a minimal cytotoxic effect

Preparation of non-biodegradable nonoparticles is a fast growing field,which is vital in both nanomedicine and nanotechnology applications.In this investigation, our attention will be focused on the preparationand evaluation of colloidal silver nanoparticles as antibacterial andantifungal agents. The colloidal silver nanoparticles have beenprepared employing standard chemical reduction methods. Thecolloidal silver nanoparticles were characterized using transmissionelectron microscopy TEM, zeta potential, photo correlationspectroscopy PCS, and in vitro release kinetics. The particles thusobtained were spherical in shape and having an average particles sizeof 5-20 nm , zeta potentials of -25.5 to -38.3 mV, and the releasekinetics was following zero order kinetics with r2>0.96. Thedissolution data indicates that the release of the silver nanoparticles isinversely correlated with the size of the nanoparticles i.e. the releaseincreased with smaller particles. The results suggest that the Ag NPswould be stable in the pharmaceutical preparations and will be easilyto the infection site. The colloidal silver nanoparticles were found tobe very efficient antibacterial agents for different types of bacteria.The bacteria studied were namely: E. coli, S. coccus, Salmonellae, andP. aeruginosa. The associated antifungal effects were also investigatedfor Aspergillus and Pencillium. . Cytotoxicity of the nanoparticle wasstudied using human fibroblast cell line. It was concluded thatcytotoxicity is concentrations dependant. The results provided strongevidence that could warrant the consideration of silver nanoparticles asantibacterial and antifungal agent that could circumvent the side andpassive effects of the conventional antibiotics.Keywords: Silver nanoparticles, antibacterial, antifungal, cytotoxicity, micro-plate assay, release kinetics

Performance characteristics of enzyme linked immunosorbent assay and rapid immunochromatographic test for routine screening of human norovirus

Noroviruses (NoV) are identified as the major cause of epidemic and sporadic acute gastroenteritis. Controlling the spread of the disease needs early recognition of NoV. This study investigated the  contribution of norovirus to sporadic cases of pediatric gastroenteritis in Zagazig University Hospitals and studied the performance characteristics of enzyme linked immunosorbent assay(EIA) and  immunochromatographic (ICT) assay for their ability to detect NoV. Two hundred stool specimens werecollected from pediatric patients with acute gastroenteritis. Samples were tested for Norovirus presence by reverse transcription PCR (RT-PCR), ICT kit and EIA. 27% of the samples showed the 338-bp portion of the RNA-dependent RNA polymerase (RdRp) gene of both Norovirus genogroups I and II by RT-PCR. The ICT assay showed high specificity (97.94%) and high sensitivity (85.18%). The EIA  showed high specificity (93.8%) but low sensitivity (64.8%). In conclusion, the high detection rate of NoV as the cause of diarrhea in children reported in this study supports their addition in screenings to  identify sporadic cases of acute gastroenteritis. The ICT and RIA Norovirus kits may be useful for rapid screening of stool samples from patients with acute gastroenteritis. However, RT-PCR should be  considered for negative samples to be confirmed.Key words: Norovirus, pediatric gastroenteritis, RNA-dependent RNA polymerase (RdRp) gene,  enzyme linked immunosorbent assay, immunochromatographic assay, Sensitivity, Specificity.Abbreviations: NoV , Noroviruses; EIA, enzyme linked immunosorbent assay; ICT,  immunochromatographic; RT-PCR, reverse transcription PCR; RdRp, RNA-dependent RNA polymerase; ORFs, open reading frames

Association of sul genes and class 1 integron with trimethoprimsulfamethoxazole Resistance in Stenotrophomonas maltophilia clinical isolates in Zagazig University, Egypt

Background: Stenotrophomonas maltophilia (S.maltophilia) is an intrinsically drug resistant    opportunistic pathogen associated with serious infections in humans. Acquired resistance to   trimethoprim-sulfamethoxazole (SXT,co-trimoxazole), the main stay of therapy against S. maltophilia ,has made its treatment more problematic. Objectives: This work aimed to determine the occurrence  of SXT resistance among S. maltophilia isolated from Zagazig University Hospitals in Egypt and to   assess the association of sul genes and integron1 with SXT-resistant isolates.Material and Methods: Thirty-two S.maltophilia isolates were identified in this study during the   period from 2013 to 2015. Screening of SXT-resistant isolates was done by Kirby-Bauer method.  Minimum inhibitory concentration(MIC) values for SXT were determined by agar dilution. S. maltophilia isolates were tested for the presence of sul1, sul2, sul3, and int 1 genes by multiplex polymerase chain reaction.Results: Amongst the 32 S. maltophilia isolates, 12(37.5%) were resistant to SXT. All SXT-resistant isolates were found to harbor sul1 gene and integron1. One of these isolates had sul2 gene  (1/12,8.3%). Meanwhile, sul3 gene was not detected in any of the SXT-resistant isolates. Only 2 of the 20 SXT-susceptible isolates was found to yield positive PCR results for sul1 gene, one of them gave positive result for class 1 Integron. The association of sul genes and Integrin1 with resistance to SXT had a statistically significant difference( P<0.0001). Conclusion: Our study indicated a high frequency of SXT resistance among clinical S.maltophilia isolates from Zagazig University Hospitals, in which sul genes and class 1 integron were found to have a major role.Keywords: Stenotrophomonas maltophilia; Sulphamethoxazole-trimethoprim-resistant; Multiplex  PCR; sul genes; Integron

Prognostic significance of del 17p, ZAP-70 and CD38 as independent indicators for B-CLL: Correlation to response to treatment and disease outcome

Prognostic markers as CD38 and ZAP-70 and specific chromosomal abnormalities as del 17p have now been developed to refine the risk of progressive disease in chronic lymphocytic leukemia (CLL). This study analyzed 40 recently diagnosed, untreated B-CLL patients for CD38 and ZAP-70 expression by flow cytometry and for del 17p by conventional cytogenetics (CCG) and by fluorescence in situ hybridization (FISH) technique to evaluate their effect on the clinical course of CLL and as risk factors for disease progression in addition to their impact on response to treatment and disease outcome. Twenty healthy age- and sex-matched subjects were included as a control. The results revealed that CD38 and ZAP-70 expression were detected in 42.5% and 47.5% of cases, respectively. They were associated with an unfavorable clinical course. Higher levels were significantly associated with increased risk of unfavorable response to treatment (P = 0.003), with poor clinical outcome (P = 0.0001). Del 17p was detected in 35% of cases by FISH technique and in 7.5% by CCG. The deletion was significantly associated with progressive clinical course; poor response to treatment (P = 0.007) but not with disease outcome (P = 0.103). Combined analysis of ZAP-70 and CD38 yielded concordantly negative results in 50% of patients and concordantly positive results in 40% of patients, while 10% were discordant. CD38+/ZAP-70+ patients were significantly associated with progressive disease (P < 0.05) and with del 17p than CD38-/ZAP-70- patients (P = 0.008). Time to disease progression (TDP) was 6 months among CD38+/ZAP-70+ patients as compared to 16 months in CD38-/ZAP-70- patients. In patients with discordant results, the TDP was 9 months. Over-representation of the three parameters (CD38, ZAP-70 and del 17p) was detected in 22.5% of cases, and pointed towards even shorter TDP (4.5 months), more aggressive disease; more resistance to chemotherapy and poor outcome thus providing a precise tool for identifying high-risk patients. In conclusion, the combined expression of CD38 and ZAP-70 together with del 17p in CLL is a precise diagnostic tool for identifying high-risk patients and convey rapid progression; they are accurate predictors of clinical outcome thus could be used to indicate when more novel chemotherapeutic approaches are needed and provided help in guiding individual patient treatment.Keywords: CLL; CD38; ZAP-70; Del 17p; Immunophenotyping; FISH; Survival stud

Nanosized rods agglomerates as a new approach for formulation of a dry powder inhaler

HF Salem1 ME Abdelrahim2 K Abo Eid3 MA Sharaf3,41Department of Pharmaceutics, 2Department of Clinical Pharmacy, Faculty of Pharmacy, The University of Beni Suef, Beni Suef; 3Department of Chemistry, Helwan University, Ain Helwan, Helwan, Egypt; 4Department of Chemistry, The American University in Cairo, New Cairo, Helwan 11835, EgyptBackground: Nanosized dry powder inhalers provide higher stability for poorly water-soluble drugs as compared with liquid formulations. However, the respirable particles must have a diameter of 1–5 µm in order to deposit in the lungs. Controlled agglomeration of the nanoparticles increases their geometric particle size so they can deposit easily in the lungs. In the lungs, they fall apart to reform nanoparticles, thus enhancing the dissolution rate of the drugs. Theophylline is a bronchodilator with poor solubility in water.Methods: Nanosized theophylline colloids were formed using an amphiphilic surfactant and destabilized using dilute sodium chloride solutions to form the agglomerates.Results: The theophylline nanoparticles thus obtained had an average particle size of 290 nm and a zeta potential of −39.5 mV, whereas the agglomerates were 2.47 µm in size with a zeta potential of −28.9 mV. The release profile was found to follow first-order kinetics (r2 > 0.96). The aerodynamic characteristics of the agglomerated nanoparticles were determined using a cascade impactor. The behavior of the agglomerate was significantly better than unprocessed raw theophylline powder. In addition, the nanoparticles and agglomerates resulted in a significant improvement in the dissolution of theophylline.Conclusion: The results obtained lend support to the hypothesis that controlled agglomeration strategies provide an efficient approach for the delivery of poorly water-soluble drugs into the lungs.Keywords: theophylline, nanoparticles, agglomerates, dry powder inhale

Інженерна комп’ютерна графіка

Розглянуто відомості про систему тривимірного моделювання КОМПАС-3D при виконанні практичних завдань, побудову тривимірних моделей деталей і складальних одиниць машин та обладнання, будівельних споруд, а також про випуск асоціативних креслеників, розробку специфікацій, експлікацій, інших текстових документів

Validation of a semi-automated technique to accurately measure abdominal fat distribution using CT and MRI for clinical risk stratification

Objective: A valid method for accurate quantification of abdominal fat distribution (AFD) using both CT and MRI is described. This method will be primarily useful in the prospective risk stratification of patients undergoing reconstructive breast surgery. Secondary applications in many other clinical specialities are foreseen. Methods: 15 sequential patients who had undergone breast reconstruction following both CT and MRI (30 scans) were retrospectively identified at our single centre. The AFD was quantified at the level of the L3 vertebra. Image analysis was performed by at least two independent operators using free software. Intra- and interobserver differences were assessed using Bland–Altman plots. Data were validated between imaging modalities by Pearson's correlation. Linear regression analyses were used to mathematically normalize results between imaging modalities. Results: The method was statistically independent of rater bias (intra: Pearson's R—0.954–1.00; inter: 0.799–0.999). Strong relationships between imaging modalities were demonstrated and are independent of time between imaging (Pearson's R 0.625–0.903). Interchangeable mathematical models to normalize between imaging modality are shown. Conclusion: The method described is highly reproducible and independent of rater bias. A strong interchangeable relationship exists between calculations of AFD on retrospective CT and MRI. Advances in knowledge: This is the first technique to be applicable to scans that are not performed sequentially or in a research setting. Analysis is semi-automated and results can be compared directly, regardless of imaging modality or patient position. This method has clinical utility in prospective risk stratification and will be applicable to many clinical specialities

A new set of integrals of motion to propagate the perturbed two-body problem

A formulation of the perturbed two-body problem that relies on a new set of orbital elements is presented. The proposed method represents a generalization of the special perturbation method published by Peláez et al. (Celest Mech Dyn Astron 97(2):131?150,2007) for the case of a perturbing force that is partially or totally derivable from a potential. We accomplish this result by employing a generalized Sundman time transformation in the framework of the projective decomposition, which is a known approach for transforming the two-body problem into a set of linear and regular differential equations of motion. Numerical tests, carried out with examples extensively used in the literature, show the remarkable improvement of the performance of the new method for different kinds of perturbations and eccentricities. In particular, one notable result is that the quadratic dependence of the position error on the time-like argument exhibited by Peláez?s method for near-circular motion under the J2 perturbation is transformed into linear.Moreover, themethod reveals to be competitive with two very popular elementmethods derived from theKustaanheimo-Stiefel and Sperling-Burdet regularizations