1,632 research outputs found
Preliminary assessment of various additives on the specific reactivity of anti- rHBsAg monoclonal antibodies
Background: Antibodies have a wide application in diagnosis and treatment. In order to maintain optimal stability of various functional parts of antibodies such as antigen binding sites, several approaches have been suggested. Using additives such as polysaccharides and polyols is one of the main methods in protecting antibodies against aggregation or degradation in the formulation. The aim of this study was to evaluate the protective effect of various additives on the specific reactivity of monoclonal antibodies (mAbs) against recombinant HBsAg (rHBsAg) epitopes. Methods: To estimate the protective effect of different additives on the stability of antibody against conformational epitopes (S3 antibody) and linear epitopes (S7 and S11 antibodies) of rHBsAg, heat shock at 37°C was performed in liquid and solid phases. Environmental factors were considered to be constant. The specific reactivity of antibodies was evaluated using ELISA method. The data were analyzed using SPSS software by Mann-Whitney nonparametric test with the confidence interval of 95%. Results: Our results showed that 0.25 M sucrose, 0.04 M trehalose and 0.5% BSA had the most protective effect on maintaining the reactivity of mAbs (S3) against conformational epitopes of rHBsAg. Results obtained from S7 and S11 mAbs against linear characteristics showed minor differences. The most efficient protective additives were 0.04 M trehalose and 1 M sucrose. Conclusion: Nowadays, application of appropriate additives is important for increasing the stability of antibodies. It was concluded that sucrose, trehalose and BSA have considerable effects on the specific reactivity of anti rHBsAg mAbs during long storage. © 2015, Avicenna Journal of Medical Biotechnology. All rights reserved
The effects of diclofenac suppository and intravenous acetaminophen and their combination on the severity of postoperative pain in patients undergoing spinal anaesthesia during cesarean section
Introduction: The main tasks of postoperative care are postoperative pain and complications control which play an important role in accelerating the recovery of patient’s general condition. Aim: This study was performed in order to compare the effects of diclofenac suppository, intravenous acetaminophen and their combination on the severity of postoperative pain in patients undergoing spinal anaesthesia for cesarean section in Sayyad Shirazi teaching Hospital, Gorgon, Iran. Materials and Methods: This was a double-blind clinical trial on 90 patients undergoing cesarean section. The patients were randomly divided into three groups, group A: 100 mg diclofenac suppository, group B: 1000 mg intravenous acetaminophen, group C: 100 mg diclofenac suppository and 500 mg intravenous acetaminophen. The same spinal anaesthesia circumstances were applied for all the participants. At the end of surgery, pain severity was assessed according to VAS scale at different times. Data were then analysed by SPSS 18 statistical software. Results: The mean age of participants was (28.27±6.07). There was significant difference between the mean pain scores of the three groups before the intervention (p=0.018), which was considered as co-variate. This difference was more notable between the combination of acetaminophen - diclofenac group and diclofenac alone. After the intervention, significant difference was observed in mean pain severity between acetaminophen group and the combination group and also between diclofenac and the combination group. During the study, the least mean pain severity was found in the combination group and the highest was observed in the diclofenac group. Conclusion: Results of this study indicates a significant effect of concomitant use of intravenous acetaminophen and diclofenac suppository on pain severity reduction and reducing the need for repeated doses of narcotics and prolonging the postoperative analgesia. © 2016, Journal of Clinical and Diagnostic Research. All rights reserved
Effect of pH on Solubilisation of Practically Insoluble Sorafenib by Classic and Stealth Polyamidoamine (PAMAM) Dendrimers and -cyclodextrin
This study is the first report of the solubilization of sorafenib (SFB), a water insoluble drug, by polyamidoamine
(PAMAM) dendrimers and -cyclodextrin ( -CD). For this study whole generations (G4 and G5)
of PAMAM dendrimers have been used. The aqueous solubility of sorafenib was measured in the presence
of dendrimers and -cyclodextin at 30 ◦ C at pH 4, 7.4, and 10 using the Higuchi rotating bottle method.
The amount of solubilized SFB was measured by HPLC-UV method. FTIR and UV-Vis spectroscopy were
used to confirm complexation. From the phase solubility studies, it was found that PAMAM dendrimers increased
SFB solubility most in pH 4. The maximum solubilizing effect was for G4 PAMAM dendrimers at
pH 4 up to 36 folds. -CD did not or slightly increased the solubility of SFB.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3494
On a Linear Program for Minimum-Weight Triangulation
Minimum-weight triangulation (MWT) is NP-hard. It has a polynomial-time
constant-factor approximation algorithm, and a variety of effective polynomial-
time heuristics that, for many instances, can find the exact MWT. Linear
programs (LPs) for MWT are well-studied, but previously no connection was known
between any LP and any approximation algorithm or heuristic for MWT. Here we
show the first such connections: for an LP formulation due to Dantzig et al.
(1985): (i) the integrality gap is bounded by a constant; (ii) given any
instance, if the aforementioned heuristics find the MWT, then so does the LP.Comment: To appear in SICOMP. Extended abstract appeared in SODA 201
A novel hydrogen peroxide biosensor based on modified electrode with hemoglobin and zinc oxide nanoparticles
In this study, direct electron transfer between immobilized hemoglobin (Hb) and zinc oxide nanoparticles modified carbon paste electrode was studied. Direct electrochemical response of Hb on the modified electrode can be achieved and a couple of well-defined and nearly reversible cyclic voltammetric peaks of Hb can be observed in a phosphate solution. The Hb immobilized on the Modified electrode with Zno Nps displayed a pair of redox peaks in 0.1 M pH 7.0 PBS with a formal potential of + (292 ± 2) mV (vs. SCE). Hb adsorbed on the modified electrode surface shows a good activity for the reduction of hydrogen peroxide (H2O2). The reduction peak currents were proportional linearly to the concentration of hydrogen peroxide. The Hb/ Zno Nps/ CPE had good repeatability and stability for the determination of H2O2
Synthesis of the erythromycin-conjugated nanodendrimer and its antibacterial activity
Abstract
The development and spread of bacterial resistance to antimicrobial drugs necessitates the need to search for novel and effective antimicrobial agents. In the last few decades, innovative nanomaterials are attracting increasing attention and, among them, dendrimers have shown wide application in the various fields. In the current study, the two generations of an anionic linear- spherical nanodendrimer G1 and G2 were synthetized and compound G2 of nanodendrimer conjugated with erythromycin. The structures of the nanodendrimers were characterized by FTIR spectroscopy, zetasizer, and scanning electron microscopy (SEM). The antibacterial activity of the erythromycin-conjugated nanodendrimer and erythromycin alone were evaluated by the microdilution method against Staphylococcus aureus, S. epidermidis, S. saprophyticus, and Pseudomonas aeruginosa. The size of first and second generation of nanodendrimer, and the erythromycin-conjugated nanodendrimer was 75, 95, and 65.6 nm, respectively. The drug loading percentage of the nanodendrimer conjugates was obtained to be in 35.2%. In our study, the erythromycin-conjugated nanodendrimer showed significantly more bacteriostatic and bactericidal activities against all four studied bacteria than erythromycin alone. Our study's results highlight that the erythromycin-conjugated nanodendrimer is a highly effective agent against Gram positive and negative bacteria. The antibacterial properties of erythromycin combined with the targeting potential of the nanodendrimer can lead to sustained intracellular delivery of therapeutic agent
Keywords:
Nanostructures
Erythromycin
Dendrimers
Antibacterial agents
Using the theory of planned behavior to identify predictors of handwashing among Iranian healthcare workers
Folate-conjugated nanoparticles as a potent therapeutic approach in targeted cancer therapy
The selective and efficient drug delivery to tumor cells can remarkably improve different cancer therapeutic approaches. There are several nanoparticles (NPs) which can act as a potent drug carrier for cancer therapy. However, the specific drug delivery to cancer cells is an important issue which should be considered before designing new NPs for in vivo application. It has been shown that cancer cells over-express folate receptor (FR) in order to improve their growth. As normal cells express a significantly lower levels of FR compared to tumor cells, it seems that folate molecules can be used as potent targeting moieties in different nanocarrier-based therapeutic approaches. Moreover, there is evidence which implies folate-conjugated NPs can selectively deliver anti-tumor drugs into cancer cells both in vitro and in vivo. In this review, we will discuss about the efficiency of different folate-conjugated NPs in cancer therapy. © 2015, International Society of Oncology and BioMarkers (ISOBM)
A Near-Global Atmospheric Distribution of N2O Isotopologues
The distributions of the four most abundant isotopologues and isotopomers (N2O, 15NNO, N15NO, and NN18O of nitrous oxide have been measured in the Earth\u27s stratosphere by infrared remote sensing with the Atmospheric Chemistry Experiment (ACE) Fourier transform spectrometer. These satellite observations have provided a near-global picture of N2O isotopic fractionation. The relative abundances of the heavier species increase with altitude and with latitude in the stratosphere as the air becomes older. The heavy isotopologues are enriched by 20-30% in the upper stratosphere and even more over the poles. These observations are in general agreement with model predictions made with the Whole Atmosphere Community Climate Model (WACCM). A detailed 3-D chemical transport model is needed to account for the global isotopic distributions of N2O and to infer sources and sinks
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