Design and characterization of biodegradable multi layered electrospun nanofibers for corneal tissue engineering applications

YesTissue engineering is one of the most promising areas for treatment of various ophthalmic diseases particularly for patients who suffer from limbal stem cell deficiency and this is due to the lack of existence of appropriate matrix for stem cell regeneration. The aim of this research project is to design and fabricate triple layered electrospun nanofibers as a suitable corneal tissue engineering scaffold and the objective is to investigate and perform various in vitro tests to find the most optimum and suitable scaffold for this purpose. Electrospun scaffolds were prepared in three layers. Poly(d, l-lactide-co-glycolide; PLGA, 50:50) nanofibers were electrospun as outer and inner layers of the scaffold and aligned type I collagen nanofibers were electrospun in the middle layer. Furthermore, the scaffolds were cross-linked by 1-ethyl-3-(3 dimethylaminopropyl) carbodiimide hydrochloride and glutaraldehyde. Structural, physical, and mechanical properties of scaffolds were investigated by using N2 adsorption/desorption isotherms, Fourier transform infrared spectroscopy, contact angle measurement, tensile test, degradation, shrinkage analysis, and scanning electron microscopy (SEM). In addition, capability to support cell attachment and viability were characterized by SEM, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay, and 4′,6-diamidino-2-phenylindole staining. According to the result of Brunauer–Emmett–Teller analysis, specific surface area of electrospun scaffold was about 23.7 m2 g-1. Tensile tests on cross-linked scaffolds represented more suitable hydrophilicity and tensile behavior. In addition, degradation rate analysis indicated that noncross-linked scaffolds degraded faster than cross-linked one and cross-linking led to controlled shrinkage in the scaffold. The SEM analysis depicted nano-sized fibers in good shape. Also, the in vitro study represented an improved cell attachment and proliferation in the presence of human endometrial stem cells for both cross-linked and noncross-linked samples. The current study suggests the possibility of producing an appropriate substrate for successful cornea tissue engineering with a novel design.Deputy of Research, Tehran University of Medical Science. Grant Number: 93‐01‐33‐2561

Enhancement of myeloma development mediated though myeloma cell-Th2 cell interactions after microbial antigen presentation by myeloma cells and DCs

Microbial agents are regarded as a potential cause of tumors, but their direct effects on tumors, such as myeloma, are not well studied. Our studies demonstrated that expression of HLA-DR and CD40 on the myeloma cell membrane surface is upregulated by interferon-γ and/or microbial antigens (Ags). Unlike prior studies, our study showed that Th2 cells cannot promote myeloma growth directly. However, Bacillus Calmette–Guerin Vaccine (BCGV)-specific Th2 cells stimulated by BCGV-loaded dendritic cells (DCs) promoted myeloma clonogenicity directly when the myeloma cells expressed major histocompatibility complex Class-II molecules (MHC-II) and took up BCGV Ag. B-cell lymphoma 6 (Bcl-6) protein expression and the proportion of HLA-DR+ or CD40+ cells were higher in colonies of Th2 cell-stimulated myeloma cells. Furthermore, anti-HLA-DR or neutralizing CD40 antibody could prevent this increase in Bcl-6 expression and colony number. These results indicate that microbes and microbial Ag-specific Th2 cells may directly impact the biology of myeloma and contribute to tumor progression. Activation may be limited to MHC-II+ myeloma cells that retain B cell and stem cell characteristics. Taken together, our data suggest that factors involved in microbial Ag presentation, such as DCs, Th2 cells and so on, are potential targets for myeloma therapeutic intervention

Usporedba djelovanja blokatora kalcijevih kanala, blokatora autonomnoga živčanog sustava te inhibitora slobodnih radikala na hiposekreciju inzulin iz izolirnih langerhansovih otočića štakora uzrokovanu diazinonom

Hyperglycaemia has been observed with exposure to organophosphate insecticides. This study was designed to compare the effects of calcium channel blockers, alpha-adrenergic, beta-adrenergic, and muscarinic receptor blockers, and of free radical scavengers on insulin secretion from diazinon-treated islets of Langerhans isolated from the pancreas of rats using standard collagenase digestion, separation by centrifugation, and hand-picking technique. The islets were then cultured in an incubator at 37 °C and 5 % CO2. In each experimental set 1 mL of 8 mmol L-1 glucose plus 125 µg mL-1 or 625 µg mL-1 of diazinon were added, except for the control group, which received 8 mmol L-1 glucose alone. The cultures were then treated with one of the following: 30 µmol L-1 atropine, 100 µmol L-1 ACh + 10 µmol L-1 neostigmine, 0.1 µmol L-1 propranolol, 2 µmol L-1 nifedipine, 50 µmol L-1 phenoxybenzamine, or 10 µmol L-1 alphatocopherol. In all experiments, diazinon significantly reduced glucose-stimulated insulin secretion at both doses, showing no dose dependency, as the average inhibition for the lower dose was 62.20 % and for the higher dose 64.38 %. Acetylcholine and alpha-tocopherol restored, whereas atropine potentiated diazinoninduced hyposecretion of insulin. Alpha-, beta- and calcium channel blockers did not change diazinoninduced effects. These findings suggest that diazinon affects insulin secretion mainly by disturbing the balance between free radicals and antioxidants in the islets of Langerhans and by inducing toxic stress.U osoba izloženih organofosfatnim insekticidima zamijećen je nastanak hiperglikemije. Svrha je ovo istraživanja bila usporediti djelovanje blokatora kalcijevih kanala, alfa i beta-adrenergičkih i muskarinskih receptora te inhibicije slobodnih radikala na lučenje inzulina iz Langerhansovih otočića izoliranih iz štakora tretiranih diazinonom. Otočići su izolirani iz gušterače štakora s pomoću standardnog postupka digestije kolagenazom, odvajanja centrifugiranjem i metodom ručnog probira (engl. hand-picking) te su kultivirani u inkubatoru pri 37 °C i 5 % CO2. Pokusne su kulture inkubirane s 1 mL glukoze u koncentraciji od 8 mmol L-1 te diazinonom u dozi od 125 μg mL-1, odnosno 625 μg mL-1. U kontrolu je dodana samo glukoza u koncentraciji od 8 mmol L-1. Nakon toga je u kulture dodan jedan od sljedećih agenasa: 30 µmol L-1 atropin, 100 µmol L-1 ACh + 10 µmol L-1 neostigmin, 0,1 µmol L-1 propranolol, 2 µmol L-1 nifedipin, 50 µmol L-1 fenoksibenzamin, odnosno 10 µmol L-1 alfa-tokoferol. U svim je pokusima diazinon značajno smanjio lučenje inzulina, s time da je doza od 125 μg mL-1 dovela do 62,2 %-tne inhibicije, a doza od 625 μg mL-1 do 64,38 %-tne inhibicije lučenja inzulina, što upućuje na djelovanje neovisno o dozi. Acetilkolin i alfa-tokoferol su ponovno potaknuli lučenje inzulina, za razliku od atropina koji ga je dodatno smanjio. Primjena blokatora alfa i beta-adrenergičkih receptora te blokatora kalcijevih kanala nije utjecala na djelovanje diazinona. Autori zaključuju da diazinon utječe na lučenje inzulina ponajviše narušavanjem ravnoteže između slobodnih radikala i antioksidansa u Langerhansovim otočićima te dovodi do toksičnoga stresa

Potent anti-nociceptive and anti-inflammatory effects of methanol fraction of Otostegia persica extract and its components

Background and objectives: Otostegia persica (Labiatae) is an endemic plant of Iran and is used for its anti-inflammatory properties in folk medicine of Sistan and Baluchestan province. The aim of the present study was to investigate the anti-nociceptive and anti-inflammatory effects of O. Persica different fractions and identification of the natural compounds from the most active fraction. Methods: Total extract of O. Persica was fractionated with petroleum ether (PE), chloroform (CL), ethyl acetate (EA), n-butanol (BU) and methanol (ME). The analgesic activities of different fractions were determined by formalin test. Then, activity of effective fractions was investigated on carrageenan-induced paw edema assay. Finally, the compounds of effective fraction were isolated and their structures were elucidated. Results: Anti-nociceptive activity of EA and BU fractions (100 mg/kg) and ME fraction (100 and 200 mg/kg) demonstrated significant difference with normal saline during the second phase of the formalin test. ME fraction showed higher analgesic effects in comparison to indomethacin (p0.05). Vicenin-2 and isorhamnetin-3-O-glucoside were elucidated from ME as the effective anti-inflammatory fraction. Conclusion: It was concluded that the existence of flavonoids in O. persica extract could play an important role for its anti-nociceptive and anti-inflammatory effects similar to various non-steroidal anti-inflammatory drugs (NSAIDS) and inhibitors of nitric oxide synthase (NOS)

Cytotoxic activity of the essential oil of Salvia verticillata L.

Salvia is one of the largest genera of  Lamiaceae family. Several species of this genus are perfumed and wealthy in essential oils. Some of them are used in industry, pharmacy and aromatherapy. They have shown different biological effects such as antibacterial and antioxidant activity. For the present study, Salvia verticillata L. was collected from Shahrestanak, Mazandaran, Iran. Hydrodistilled essential oil from the aerial parts of this plant was obtained with a Clevenger type  apparatus  and was analyzed by GC and GC/MS. Moreover, the cytotoxic activity of the essential oil was investigated against HT-29 (colon adenocarcinoma), Caco-2 (colorectal adenocarcinoma), T-47D (breast ductal carcinoma) and NIH-3T3 (Swiss mouse embryo fibroblast) cell lines by MTT test. 59 components were characterized from the oil with trans-caryophyllene (24.40%), β-phellandrene (9.08%), α-humulene (8.61%), bicyclogermacrene (6.32%), spathulenol (5.89%) and β-pinene (5.00%) as the major constituents. These compounds represented 97.67% of the essential oil and included monoterpenes (34.83%) and sesquiterpens (61.84%). The results of the cytotoxicity assay demonstrated that the essential oil of S. verticillata showed higher cytotoxic effect on Caco-2 cell line

IMMUNOHISTOCHEMICAL EXPRESSION OF p53 AND BCL-2 PROTEINS IN ADVANCED ESOPHAGEAL CANCER PATIENTS

The current challenges in the management of esophageal cancer are to obtain a better understanding of underlying molecular alterations to provide new treatment options. We studied the p53 and Bcl-2 protein expression in esophageal carcinomas to correlate molecular alterations with clinicopathological findings. Tissue samples of 37 patients with advanced esophageal carcinoma were analyzed by immunohistochemical techniques. Positive immunostaining for p53 and Bcl-2 were observed in 67.6% and 43.6% of tumor samples, respectively. The prevalence of Bcl-2 overexpression was significantly greater in p53+ tumors ‎as compared with p53- tumors (P = 0.003). Unlike p53, positive Bcl-2 immunostaining correlated significantly with tumor type (P = 0.001) and histological differentiation (P = 0.007). Our data also showed that 35% of patients were positive for both proteins and 32.4% of patients were positive for p53 but negative for Bcl-2 expression. These results indicate two types of double gene alterations that obviously would affect tumor biology and response to chemotherapy. Therefore, it is advisable to determine expression profile of certain genes including p53 and Bcl-2 in tumor samples before selecting chemotherapy regimen