In Vitro Insulin Release from Thermosensitive Chitosan Hydrogel

Recently, great attention has been paid to in situ gel-forming chitosan/glycerol-phosphate (chitosan/Gp) solution due to their good biodegradability and thermosensitivity. This in situ gel-forming system is injectable fluid that can be introduced into the body in a minimally invasive manner prior to solidifying within the desired tissue. At the present study, insulin release from chitosan/Gp solution has been investigated. Insulin in different concentrations was loaded in two formulations of chitosan/Gp solution and in vitro drug release was studied over a period of 3 weeks. Results indicated that the release of insulin from chitosan/Gp gel decreases by increasing in Gp salt and initial insulin concentration. Stability of released insulin was investigated by 8-anilino-1-naphthalenesulfonate probe. Results proved that insulin have been released in its native form. Because of simple preparation and administration, prolonged release of insulin and stability of released insulin, this in situ gel-forming system could be used as a controlled release delivery system for insulin.KEY WORDS: biodegradable, chitosan, controlled release, in situ forming, insulin     

Trends in Asthma-Related Direct Medical Costs from 2002 to 2007 in British Columbia,Canada: A Population Based-Cohort Study

Background

Asthma-related health resource use and costs may be influenced by increasing asthma prevalence, changes to asthma management guidelines, and new medications over the last decade. The objective of this work was to analyze direct asthma-related medical costs, and trends in total and per-patient costs of hospitalizations, physician visits, and medications.

Methods

A cohort of asthma patients from British Columbia (BC), Canada, was created. Asthma patients were identified using a validated case definition. Costs for hospitalizations, physician visits, and medications were calculated from billing records (in 2008 Canadian dollars). Trends in total and per-patient costs over the study period were analyzed using Generalized Linear Models.

Results

398,235 patients satisfied the asthma case definition (mid-point prevalence 8.0%). Patients consumed $315.9 million (M) in direct asthma-related health resources between 2002 and 2007. Hospitalizations, physician visits, and medication costs accounted for 16.0%, 15.7% and 68.2% of total costs, respectively. Cost of asthma increased from $49.4 M in 2002 to $54.7 M in 2007. Total annual costs attributable to hospitalizations and physician visits decreased (−39.8% and −25.5%, respectively; p<0.001), while medication costs increased (+38.7%; p<0.001).

Interpretation

This population-based analysis shows that the total direct cost of asthma in BC has increased since 2002, mainly due to a rise in asthma prevalence and cost of medication. Combination therapy with inhaled corticosteroids/long-acting beta-agonists has become a significant component of the cost of asthma. Although billing records capture only a fraction of the true burden of asthma, the simultaneous increase in medication costs and reductions in hospitalization and physician visit costs provides valuable insight for policy makers into the shifts in asthma-related resource use.     

Evaluation of Copper Bioaccumulation and Translocation in Jatropha curcas Grown in a Contaminated Soil

Contamination of soils with copper (Cu) has become a serious problem in the environment. Phytoremediation is an emerging green technology that uses green plants to remediate heavy metal contaminated areas. This study was conducted to evaluate the potential of Jatropha curcas for remediation of soils contaminated with Cu. Seedlings were planted in soils spiked with Cu in amount of 0, 50, 100, 200, 300, and 400 mg kg^–1 (Cu_0, Cu₅₀,Cu₁₀₀,Cu₂₀₀,Cu_300, and Cu₄₀₀) for a period of five months. The maximum height and number of leaves were recorded in control (Cu₀) whereas the highest basal stem diameter was found in seedlings exposed to Cu₅₀. Copper concentrations among plant parts were in the following trend: roots > stems > leaves. The highest total Cu concentration (665 ± 1 mg kg^?1) and total Cu removal (1.2 ± 0.2%) based on total plant dry biomass were found in Cu₄₀₀ and Cu₅₀ treatments, respectively. J. curcas exhibited high root concentration factor (RCF > 1) and low translocation factor (TF < 1). Although Cu accumulation by the plant didn't reach the criteria of Cu hyperaccumulators, this species showed a potential to be used in phytostabilization of mildly Cu contaminated areas. However, the plant cannot be used for phytoextraction of Cu-contaminated soils.     

Construction and eukaryotic expression of recombinant large hepatitis delta antigen

Background:

Hepatitis delta virus (HDV) is a subviral human pathogen that exploits host RNA editing activity to produce two essential forms of the sole viral protein, hepatitis delta antigen (HDAg). Editing at the amber/W site of HDV antigenomic RNA leads to the production of the large form (L-HDAg), which is required for RNA packaging.

Methods:

In this study, PCR-based site-directed mutagenesis by the overlap extension method was used to create the point mutation converting the small-HDAg (S-HDAg) stop codon to a tryptophan codon through three stages.

Results:

Sequencing confirmed the desirable mutation and integrity of the L-HDAg open reading frame. The amplicon was ligated into pcDNA3.1 and transfected to Huh7 and HEK 293 cell lines. Western blot analysis using enhanced chemiluminescence confirmed L-HDAg expression. The recombinant L-HDAg localized within the nuclei of cells as determined by immunofluorescence and confocal microscopy.

Conclusion:

Because L-HDAg requires extensive post-translational modifications, the recombinant protein expressed in a mammalian system might be fully functional and applicable as a tool in HDV molecular studies, as well as in future vaccine research.Key Words: Hepatitis Delta Virus, L-HDAg, SOEing-PCR     

In vivo and in vitro evidence for the involvement of Nrf2-antioxidant response element signaling pathway in the inflammation and oxidative stress induced by particulate matter (PM10): the effective role of gallic acid

Environmental pollution is one of the risk factors for respiratory diseases. The nuclear factor erythroid 2-related factor 2 (Nrf2) is the major mechanisms contributing to cellular defense against oxidative damage. Gallic acid (GA) is regarded as potent anti-inflammatory and antioxidant agents. The aim was to evaluate the role of Nrf2 pathway in particulate matter (PM₁₀) exposure on lung and epithelial cells with an emphasis on the role of GA. In in vivo part, the rats were divided as control, GA (30?mg/kg), particulate matter (PM) (0.5, 2.5, and 5?mg/kg), and PM?+?GA. In in vitro study, the cells were divided as control, PM₁₀ (100, 250, and 500?µg/ml), GA (50 µmol/L) and PM₁₀+GA. Inflammation, oxidative stress and Nrf2-pathway factors were assessed. PM₁₀ groups showed a considerable increase in the epithelial permeability and inflammatory parameters. We also found a significant decrease in the expression of Nrf2 and its up-stream regulators genes. Accordingly, the biosynthesis of glutathione (GSH) and other antioxidant activities significantly decreased. Gallic acid was identified to restore the antioxidant status to the normal levels. Our findings approved that Nrf2 is involved in PM₁₀-induced oxidative damages and showed that Nrf2 activation by natural agents could ameliorate respiratory injuries induced by PM₁₀.     

Analysis of the molecular variation between and within cultivated and wild Pistacia species using AFLPs

Knowledge of pistachio genetic diversity is necessary for the formulation of appropriate management strategies for the conservation of these species. We analysed amplified fragment length polymorphisms in a total of 216 pistachio accessions, which included seven populations from three wild species (Pistacia vera, Pistacia khinjuk and Pistacia atlantica subsp. kurdica) and most of the important cultivars from Iran, together with some foreign cultivars. High levels of genetic diversity were detected within the Iranian cultivars, and they showed a clear separation from foreign cultivars, as revealed by unweighted pair group method with arithmetic averaging and supported by analysis of molecular variance. The lowest amount of polymorphism was observed in P. atlantica subsp. kurdica, which showed the lowest number of total bands as compared to the other species. This revealed strong genetic erosion of P. atlantica subsp. kurdica, which reflected a severe decline in habitat and over-exploitation. Based on these findings, strategies are proposed for the genetic conservation and management of pistachio species and cultivars.     

Resonance Raman measurement of macular carotenoids in the living human eye

There is growing evidence that high levels of the macular xanthophyll carotenoids lutein and zeaxanthin may be protective against visual loss from age-related macular degeneration. To study this protective effect further, it is important to measure macular carotenoid levels noninvasively in a wide variety of subjects. We have developed and validated resonance Raman spectroscopy as a sensitive and specific objective method to measure macular carotenoid levels in the living human eye. In this minireview, the principles and implementation of ocular carotenoid resonance Raman spectroscopy are reviewed, and the results of observational cross-sectional studies and of prospective supplementation studies on subjects with and without macular pathology are summarized. We have recently extended this technology to an imaging mode which will further enhance our understanding of the roles of lutein and zeaxanthin in normal macular function and in the prevention of age-related visual loss.