Biolmpacts
Volume:2 Issue: 1, Mar 2012

Entry of blood circulating agents into the brain is highly selectively controlled by specific transport machineries at the blood brain barrier (BBB), whose excellent barrier restrictiveness make brain drug delivery and targeting very challenging. Essential information on BBB cellular microenvironment were reviewed and discussed towards impacts of BBB on brain drug delivery and targeting. Brain capillary endothelial cells (BCECs) form unique biological structure and architecture in association with astrocytes and pericytes, in which microenvironment the BCECs express restrictive tight junctional complexes that block the paracellular inward/outward traverse of biomolecules/compounds. These cells selectively/specifically control the transportation process through carrier and/or receptor mediated transport machineries that can also be exploited for the delivery of pharmaceuticals into the brain. Intelligent molecular therapies should be designed using such transport machineries for the efficient delivery of designated drugs into the brain. For better clinical outcomes, these smart pharmaceuticals should be engineered as seamless nanosystems to provide simultaneous imaging and therapy (multimodal theranostics). The exceptional functional presence of BBB selectively controls inward and outward transportation mechanisms, thus advanced smart multifunctional nanomedicines are needed for the effective brain drug delivery and targeting. Fully understanding the biofunctions of BBB appears to be a central step for engineering of intelligent seamless therapeutics consisting of homing device for targeting, imaging moiety for detecting, and stimuli responsive device for on-demand liberation of therapeutic agent.

The severe need for constructing replacement tissues in organ transplantation has necessitated the development of tissue engineering approaches and bioreactors that can bring these approaches to reality. The inherent limitations of conventional bioreactors in generating realistic tissue constructs led to the devise of the microgravity tissue engineering that uses Rotating Wall Vessel (RWV) bioreactors initially developed by NASA. In this review article, we intend to highlight some major advances and accomplishments in the rapidly-growing field of tissue engineering that could not be achieved without using microgravity. Research is now focused on assembly of 3 dimensional (3D) tissue fragments from various cell types in human body such as chondrocytes, osteoblasts, embryonic and mesenchymal stem cells, hepatocytes and pancreas islet cells. Hepatocytes cultured under microgravity are now being used in extracorporeal bioartificial liver devices. Tissue constructs can be used not only in organ replacement therapy, but also in pharmaco-toxicology and food safety assessment. 3D models of various cancers may be used in studying cancer development and biology or in high-throughput screening of anticancer drug candidates. Finally, 3D heterogeneous assemblies from cancer/immune cells provide models for immunotherapy of cancer. Tissue engineering in (simulated) microgravity has been one of the stunning impacts of space research on biomedical sciences and their applications on earth.

Emergency department manages several kinds of wounds including simple, non-bite traumatic wounds and lacerations. Prophylactic antibiotic therapy is one of prescribed treatment in these conditions. We aimed to compare the clinical efficacy of the two day regimen of prophylactic antimicrobial agents with the five day regimen in simple traumatic but highly contaminated wounds. Between January 2010 and May 2010, patients presenting with simple traumatic wounds or lacerations in different parts of the body, highly contaminated with soil, debris or feces in emergency department of a referral educational hospital in Tehran (Rasul-Akram hospital), Iran, went for primary closure. All of the patients were provided prophylactic antibiotic, however, prescribed for one group (A) of patients for 2 days and other group (B) received for 5 days, according to the physician concerned. As these treatments were routine, we selected 70 patients from each group using table of random numbers. The patients were warned about the signs of infection including long-lasting erythema, purulent discharge and inflammation and were supposed to inform the concerned physician in any of such alarming situations. Oral Cephalexin 500 mg qid was prescribed for all patients enrolled for prophylaxis treatment. On follow-up 11 (8.2%) patients were found to develop sutured site infection (6 out of 70 (8.57%) in group A, and five out of 70 (7.14%) in group B (P=0.31)). There was no statistical difference between infection rates between men (8.6%) in comparison to women (6.25%) (P>0.05; CI=95%). Our study showed that 2-day prophylactic antibiotic therapy using Cephalexin is at least as effective as a 5-day regimen in relation to development of surgical site infection in patients with simple traumatic contaminated wounds or lacerations.

Hypouricemic, antioxidant and xanthine oxidase inhibitory effects of orange juice and hesperetin have been already indicated. The objective of this study was to investigate the effects of orange juice and hesperetin on paraoxonase and arylesterase activity and lipid profile of hyperuricemic rats. Forty eight male Wistar rats were divided into 8 equal groups of healthy control, healthy+orange juice, healthy+hesperetin, healthy+allopurinol, hyperuricemic control, hyperuricemic+orange juice, hyperuricem-ic+hesperetin and hyperuricemic+allopurinol. Hyperuricemia was induced using potassium oxonate (250 mg/kg ip). The treatments were carried out by daily gavage of 5 ml/kg orange juice, 5 mg/kg hesperetin and 5 mg/kg allopurinol for 2 weeks. Paraoxonase activity in serum was measured spectrophotometrically using paraoxon and phenylacetate as substrates. Serum lipids levels were determined using enzymatic colorimetric methods. Hyperuricemia-induced reduction of paraoxonase and arylesterase activity was restored after treatment with orange juice and hesperetin (p<0.05). The effect of both treatments on lipid profile was marginal and only orange juice could significantly increase the levels of HDL-C. Supplementation of orange juice and hesperetin could restore paraoxonase and arylesterase activity in hyperuricemic rats. Orange juice could also partially improve the lipid profile. These effects could have major implications with respect to the prevention of cardiovascular disease in hyperuricemic patients. However, more studies are needed in future investigations.

Pedicularis sibthorpii and P. wilhelmsiana are endemic species mainly found in North-West of Iran. Plants of genus Pedicularis produce some important polyphenols and flavonoids. In the present work, total phenol and flavonoid contents of the mentioned species as well as their antioxidant capacity have been evaluated. Methanol extract of samples was fractionated by SPE method using an ODS cartridge and their 1H-NMR spectra were recorded. Total phenols and flavonoids of methanol extracts were determined using Folin- Ciocalteu and aluminum chloride methods. For determining antioxidant activity of the extracts and fractions, bleaching of purple colour methanol solution of 1, 1-diphenylpycryl hydrazyl (DPPH) was measured by spectrophotometric assay. Total phenols of Pedicularis sibthorpii and P. wilhelmsiana were in the range of 8-30 mg g-1 and 9-20 mg g-1, respectively. The 40% and 60% fractions of P.sibthorpii and the 20%, 40% and 60% fractions of P. wilhelmsiana showed higher amounts of phenolic compounds. The total flavonoid contents of P. sibthorpii and P. wilhelmsiana were in the range of 0-215 mg g-1 and 0-177 mg g-1, respectively, whereas the 40% and 60% fractions showed higher flavonoid amounts. Antioxidant activity of P. sibthorpii and P. wilhelmsiana were in the range of 0.01-0.7 mg mL-1 and 0.01-1.02 mg mL-1. In the same manner, the 20% and 40% fractions of P. sibthorpii and the 40% and 60% fractions of P. wilhelmsiana had lower RC50 than that of other fractions. Fractions with lower RC50 had higher contents of phenolic and flavonoid compounds. The results of NMR spectra were parallel with these findings and show that it is worth to do phytochemical studies on P. sibthorpii and P. wilhelmsiana.

Production of complex human recombinant proteins is an important issue in medical biotechnology. These proteins are mostly expressed in non-human mammalian host cells. This has some problems including non-human post-translational modifications, application of high-cost agents for inducing protein expression and low yields. Therefore, it is necessary to use new expression systems to overcome the indicated challenges. In this paper, we hypothesize the application of promoter regions of cancer genes, which have a high rate of transcription in human cancer cell lines, for designing new expression vectors. After designing, these vectors could be applied to produce complex human recombinant proteins in the human cancer cell lines as production hosts. Application of these expression vectors for the production of recombinant human proteins in the human cancer cell lines have some advantages including authentic post-translational modifications, proper-cost of commercialization, and high yields.

selection of journal for publication purpose is one of concerns of biomedical researchers. They apply various criteria to choose appropriate journal. Here, we have tried to collect main criteria biomedical researchers use to select a journal to submit their work. we collected these criteria through focus group conversations with researchers during our careers, feedbacks from participants of our scientific writing workshops and non-systematic reviewing of some related literature. we have presented a summative and informative guidance in selection of biomedical journals for biomedical paper submission and publication. Categorized criteria as a mnemonic tool for authors may help the authors in journal selection process.