Implantable biodegradable sponges: effect of interpolymer complex formation of chitosan with gelatin on the release behavior of tramadol hydrochloride

The effect of interpolymer complex formation between positively charged chitosan and negatively charged gelatin (Type B) on the release behavior of tramadol hydrochloride from biodegradable chitosan-gelatin sponges was studied. Mixed sponges were prepared by freeze-drying the cross-linked homogenous stable foams produced from chitosan and gelatin solutions where gelatin acts as a foam builder. Generation of stable foams was optimized where concentration, pH of gelatin solution, temperature, speed and duration of whipping process, and, chitosan-gelatin ratio drastically affect the properties and the stability of the produced foams. The prepared sponges were evaluated for their morphology, drug content, and microstructure using scanning electron microscopy, mechanical properties, uptake capacity, drug release profile, and their pharmacodynamic activity in terms of the analgesic effect after implantation in Wistar rats.

It was revealed that whipping 7% (w/w) gelatin solution, of pH 5.5, for 15 min at 25°C with a stirring speed of 1000 rpm was the optimum conditions for stable gelatin foam generation. Moreover, homogenous, uniform chitosan-gelatin foam with small air bubbles were produced by mixing 2.5% w/w chitosan solution with 7% w/w gelatinsolution in 1:5 ratio. Indeed, polyionic complexation between chitosan and gelatin overcame the drawbacks of chitosan sponge mechanical properties where, pliable, soft, and compressible sponge with high fluid uptake capacity was produced at 25°Cand 65% relative humidity without any added plasticizer. Drugreleasestudies showed a successful retardation of the incorporated drug where the t_50% values of the dissolution profiles were 0.55, 3.03, and 4.73 hr for cross-linked gelatin, un-cross-linked chitosan-gelatin, and cross-linked chitosan-gelatin sponges, respectively. All the release experiments followed Higuchi's diffusion mechanism over 12 hr. The achieved drug prolongation was a result of a combined effect of both cross-linking and polyelectrolyte complexation between chitosan and gelatin. The analgesic activity of the implanted tramadol hydrochloride mixed chitosan-gelatin sponge showed reasonable analgesic effect that was maintained for more than 8 hr. Therefore, the use of chitosan and gelatin together appears to allow the formulator to manipulate both the drug release profiles and the mechanical properties of the sponge that could be effectively implanted.     

Gesture behavior in unmedicated schizotypal adolescents.

Schizotypal personality disorder is characterized by interpersonal and verbal communication deficits. Despite the important role of gesture in social communication, no published reports examine the use of gesture by individuals with SPD. In this study, raters code gesture from videotaped interviews of unmedicated adolescents with SPD, other personality disorders, or no Axis II disorder. Results indicate that SPD adolescents show significantly fewer gestures but do not differ from the other groups in overall rate of movement. The findings are discussed in light of brain regions involved in dysfunction, parallels to schizophrenia, and treatment implications. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Assessment of personal hygiene knowledge, and practices in Al Ain, United Arab Emirates

There is little information available about incidences and causes of foodborne illnesses that can help the government develop policies, which prevent them in the UAE. This study includes a group of multinational subjects (males and females), residing in Al Ain, UAE, and of an age ranging between 15 and 55 years. A questionnaire designed to assess “Knowledge” and “Practice” of public hygiene measures was piloted in a group of subjects from the public (n = 600). Data shows that 100% of highly educated subjects with postgraduate degrees (Master and PhD) have the proper information about food safety. However, only 70% of them always wash their hands before and after eating, while 80% always wash their hands after using toilets and frequently using warm water and soap. 29% of the total participants were inflicted with foodborne illness, and 85% read articles about food safety and personal hygiene. Most of the subjects in this study are Muslims, and they mainly depended on their daily attitude, which affects their personal hygiene because they must wash before praying. Data generally referred that awareness programs or training are needed, even for the highly educated members of the public. Further research is needed to explain the differences between reports of actual and usual behaviors.     

A Novel Optimized Language-Independent Text Summarization Technique

A substantial amount of textual data is present electronically in several languages. These texts directed the gear to information redundancy. It is essential to remove this redundancy and decrease the reading time of these data. Therefore, we need a computerized text summarization technique to extract relevant information from group of text documents with correlated subjects. This paper proposes a language-independent extractive summarization technique. The proposed technique presents a clustering-based optimization technique. The clustering technique determines the main subjects of the text, while the proposed optimization technique minimizes redundancy, and maximizes significance. Experiments are devised and evaluated using BillSum dataset for the English language, MLSUM for German and Russian and Mawdoo3 for the Arabic language. The experiments are evaluated using ROUGE metrics. The results showed the effectiveness of the proposed technique compared to other language-dependent and language-independent summarization techniques. Our technique achieved better ROUGE metrics for all the utilized datasets. The technique accomplished an F-measure of 41.9% for Rouge-1, 18.7% for Rouge-2, 39.4% for Rouge-3, and 16.8% for Rouge-4 on average for all the dataset using all three objectives. Our system also exhibited an improvement of 26.6%, 35.5%, 34.65%, and 31.54% w.r.t. The recent model contributed in the summarization of BillSum in terms of ROUGE metric evaluation. Our model’s performance is higher than the compared models, especially in the metric results of ROUGE_2 which is bi-gram matching.     

Upgrading of dissolution and anti-hypertensive effect of Carvedilol via two combined approaches: self-emulsification and liquisolid techniques

Objective: The aim of the study was to design a self-emulsifying drug delivery system (SEDDS) of the anti-hypertensive Carvedilol in liquid and liquisolid forms as a way to enhance its dissolution profile and anti-hypertensive effect.

Methods: Solubility studies of Carvedilol in various oils, surfactants and co-surfactants were conducted, followed by the construction of pseudo-ternary phase diagrams and other in vitro assessments. The selected SEDDS formulation (S1) was adsorbed onto solid powder excipients and compressed into tablets. The resulting liquisolid tablets were evaluated under British Pharmacopoeia (B.P.) specifications. Pre- and post-compression studies were performed to determine the flow properties and evaluate the liquisolid systems, followed by in vivo studies in hypertensive rats.

Results: Attempts of self-emulsification, droplet size, and thermodynamic stability studies showed acceptable results for the S1 formulation containing Capryol 90, Tween 20, and Transcutol HP (10:53.3:26.2%), respectively. Pre-compression studies showed adequate flowability and compatibility of liquid and solid excipients with Carvedilol. The selected liquisolid tablet (LS7) demonstrated the best disintegration and water absorption ratio in addition to satisfactory friability and hardness. A significantly (p?®. The in vivo study of LS7 formulation revealed a rapid significant (p?®.

Conclusion: Self-emulsifying liquisolid tablets expressed rapid onset of action with enhanced anti-hypertensive effect of Carvedilol.     

Propolis emulgel: a natural remedy for burn and wound

Objectives: To develop an alternative medicine, propolis, in emulgel formulation for burn and wound treatment.

Methods: The effect of two independent variables: emulsifying agent concentration and oil concentration on the cumulative amount of propolis release (dependent variable) from liquid paraffin and isopropyl palmitate emulgels was investigated. Eight formulations were prepared and evaluated for physical appearance, pH, propolis content, viscosity, and in vitro propolis release. The release results were fitted into different kinetic equations and analyzed using contour plot, interaction surface plot and one-way ANOVA. The selected emulgel formulation was investigated for its wound and burn healing activity in rats.

Results: All the prepared emulgels showed acceptable physical properties concerning color, homogeneity, consistency, and pH value. The concentration of emulsifying agent had more pronounced effect on propolis release than oil concentration. Formulations F1–F6 showed “anomalous” drug release, while Formulations F7 and F8 showed zero-order kinetic.

Conclusion: The formulation F7 with 5% isopropyl palmitate, 5% emulsifier mixture, 1% hydroxyl propyl methyl cellulose, 1% oleic acid, and 10% propylene glycol is a promising formula for better management of wound and burn.     

Effect of needle orientation during arteriovenous access puncture on needed compression time after hemodialysis: A randomized controlled trial

Background

There are two techniques for puncturing an arteriovenous fistula: one where the needle is inserted bevel up and then rotated to a bevel down position, and another where the needle is inserted bevel down. The aim of this study was to compare these two methods of needle insertion on minimum compression time required for hemostasis after needle removal.

Methods

This was a prospective, randomized, cross-over, blinded, single-center, routine care study. Each patient's average post-dialysis puncture site compression time was determined during a 2-week baseline period while using bevel-up access puncture. Subsequently, minimum post-dialysis puncture-site compression time was determined during each of two sequential follow-up periods, during which fistula puncture was done with needles inserted bevel up or down, respectively. The order of treatments (bevel up or bevel down insertion) was randomized. During each follow-up period, the minimum compression time necessary to avoid bleeding on needle removal was determined by progressively shortening the compression time. Puncture-associated pain was also assessed as prepump and venous pressures and ability to achieve desired blood flow rate during the dialysis session.

Results

Forty-two patients were recruited. The baseline compression time after needle removal averaged 9.99 ± 2.7 min During the intervention periods, the minimum compression time was on average 10.8 min (9.23–12.4) when the access needles had been inserted bevel down versus 11.1 min (9.61–12.5) when the access needles had been inserted bevel up (p = 0.72). There was no difference in puncture-associated pain between the two insertion techniques, and no difference in prepump or venous pressures or ability to achieve the desired blood flow rate during the dialysis session.

Conclusion

Bevel-up and bevel-down needle orientation during arteriovenous fistula puncture are equivalent techniques in terms of achieving hemostasis on needle removal, and puncture-associated pain.     

Lanthanide amino acid Schiff base complexes： synthesis, spectroscopic characterization, physical properties and in vitro antimicrobial studies

Complexes of La(Ⅲ),Nd(Ⅲ),Gd(Ⅲ),Sm(Ⅲ),and Ce(Ⅳ) were synthesized with Schiff base [(3,5-di-tert-butyl-2-hydroxybenzyl) amino] acetic acid(H 3 L).The ligand and its complexes were synthesized and characterized based on the following analysis:elemental analyses,FAB-mass,molar conductance measurements,magnetic measurement,UV-visible,IR,and NMR spectral studies.The spectral data revealed that the ligand acted as a neutral tridentate coordinating to metal ion through ONO donor sequence.Thermal degradation studies of the ligand and its complexes showed that the previous lanthanide complexes were more thermally stable than the ligand itself.The Schiff base and its complexes were screened for their antibacterial(Escherichia coli,Staphylococcus aureus) and antifungal(Aspergillus flavus and Candida Albicans).     

Cumulative voting consensus method for partitions with variable number of clusters

Over the past few years, there has been a renewed interest in the consensus clustering problem. Several new methods have been proposed for finding a consensus partition for a set of n data objects that optimally summarizes an ensemble. In this paper, we propose new consensus clustering algorithms with linear computational complexity in n. We consider clusterings generated with random number of clusters, which we describe by categorical random variables. We introduce the idea of cumulative voting as a solution for the problem of cluster label alignment, where, unlike the common one-to-one voting scheme, a probabilistic mapping is computed. We seek a first summary of the ensemble that minimizes the average squared distance between the mapped partitions and the optimal representation of the ensemble, where the selection criterion of the reference clustering is defined based on maximizing the information content as measured by the entropy. We describe cumulative vote weighting schemes and corresponding algorithms to compute an empirical probability distribution summarizing the ensemble. Given the arbitrary number of clusters of the input partitions, we formulate the problem of extracting the optimal consensus as that of finding a compressed summary of the estimated distribution that preserves maximum relevant information. An efficient solution is obtained using an agglomerative algorithm that minimizes the average generalized Jensen-Shannon divergence within the cluster. The empirical study demonstrates significant gains in accuracy and superior performance compared to several recent consensus clustering algorithms.