Iranian Journal of Basic Medical Sciences
Year:2013 | Volume:16 | Issue:12|Papers Count:12

Objective (s): Renal ischemia reperfusion (IR) contributes to the development of acute renal failure (ARF). Oxygen free radicals are considered to be principal components involved in the pathophysiological tissue alterations observed during renal IR. The purpose of this study was to investigate the effect of co-administration of melatonin (MEL) and erythropoietin (EPO), potent antioxidant and anti-inflammatory agents, on IR-induced renal injury in rats.Materials and Methods: Wistar albino rats were unilaterally nephrectomized and subjected to 45 min of renal pedicle occlusion followed by 24 hr reperfusion. MEL (10 mg/kg, IP) and EPO (5000 U/kg, IP) were administered prior to ischemia. After 24 hr reperfusion, following decapitation, renal samples were taken for the determination of malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) levels and histological evaluation. The level of urea was measured in serum samples.Results: Ischemia reperfusion significantly increased urea, and MDA levels, and decreased CAT and SOD activities. Histopathological findings of the IR group confirmed that there was renal impairment in the tubular epithelium. Treatment with EPO and MEL markedly decreased urea level and increased SOD and GPx activities.Conclusion: Treatment with EPO and MEL had a beneficial effect on renal IR injury. These results may show that the co-administration of MEL and EPO cannot exert more beneficial effects than either agent alone.

Objective (s): The impact of fasting in Ramadan as a unique type of nutritional regimen on biochemical and hematological parameters is still an issue of debate. Almost very little is known regarding the regulatory role (s) of this nutritional status on immune responses or inflammation.Materials and Methods: The levels of biochemical parameters were determined using commercial diagnostic kits. Hematological parameters were also examined. We also employed ELISA for detection of CXCL1, CXCL10 and CXCL12 chemokines. The Student-T test was used to compare the values of different parameters obtained in the first and last day of Ramadan fasting by employing SPSS (version 18) software.Results: As our findings demonstrated, there was a markedly difference between before and after Ramadan BMI of the individuals who fast. Our results also revealed that there was a remarkable difference between the levels of total cholesterol, FBS, Triglycerides and LDL before and after Ramadan fasting. Results revealed that among studied hematological parameters only the numbers of platelets were markedly different before and after Ramadan fasting program in individuals who practice fasting. Our results also showed decreased levels of pro-inflammatory CXC chemokines but unaltered levels of homoeostatic ones.Conclusion: The results of this study may reveal that Ramadan fasting is quite safe for normal healthy adults and so very useful in reduction of cholesterol and triglycerides in relation with dyslipidemia. It is also possible to conclude that fasting is important in controlling of inflammation via chemokines.

Objective (s): The aim of this work was to investigate the effect of the natural and the chemically modified form of cyclodextrins namely; b -cyclodextrin (β-CD) and hydroxypropyl-b-cyclodextrin (HP- b -CD) respectively on the solubility and dissolution rate of aripiprazole; an antipsychotic medication showing poor aqueous solubility.Materials and Methods: Phase solubility of aripiprazole with the studied CDs and the complexation efficiency values (CE) which reflect the solubilizing power of the CDs towards the drug was performed. Solid binary systems of aripiprazole with CDs were prepared by kneading, microwave irradiation and freeze-drying techniques at 1: 1 and 1: 2 (drug to CD) molar ratios. Drug-CD physical mixtures were also prepared in the same molar ratios for comparison. The dissolution of aripiprazole-binary systems was carried out to select the most appropriate CD type, molar ratio and preparation technique.Results: Phase solubility study indicated formation of higher order complexes and the complexation efficiency values was higher for HP- b -CD compared to b -CD. Drug dissolution study revealed that aripiprazole dissolution was increased upon increasing the CD molar ratio and, the freeze-drying technique was superior to the other studied methods especially when combined with the HP- b -CD. The cyclodextrin type, preparation technique and molar ratio exhibited statistically significant effect on the drug dissolution at P≤0.05.Conclusion: The freeze-dried system prepared at molar ratio 1: 2 (drug: CD) can be considered as efficient tool for enhancing aripiprazole dissolution with the possibility of improving its bioavailability.

Objective (s): Bacterial infection contributes substantially to neonatal morbidity and mortality. Early diagnosis of neonatal sepsis is difficult because clinical signs are non-specific. We have evaluated serum IL-6, 8 and 10 as potential early diagnostic markers of neonatal infection and their relationship to mortality rate and poor prognosis.Materials and Methods: A total of 84 infants, aged ≥ 72 hr were enrolled in this prospective case-control trial. The case group (n=41) included babies with clinical and laboratory findings compatible with sepsis and/or positive blood or cerebrospinal fluid cultures. The control group (n=43) included healthy infants. IL-6, 8 and 10 were measured for all infants. Receiver-operating characteristic (ROC) curves were used for the determination of thresholds.Results: Statistically significant differences were observed between control and case groups for serum median level of IL-6, 8 and 10 (P<0.001). IL-6 cut-off values of 10.85 Pg/ml for discriminating between cases and controls and 78.2 Pg/ml for predicting mortality are suggested. IL-8 at a cut-off value of 60.05 Pg/ml was valuable for differentiation of definite versus indefinite infection.Conclusion: Evaluating the IL-6, 8 and 10 simultaneously, could improve the sensitivity and specificity of early diagnosis of the neonatal sepsis. Regarding our results, interleukin 6 had the greatest value for predicting infection and possible mortality, whereas IL-8 was valuable for diagnosing definitive infection.

Objective (s): Nowadays, COX-2 inhibitors such as valdecoxib are removed from the market because of their cardiovascular toxicity and their potential to increase the risk of strokes. In response to this, medicinal chemists have attempted to synthesize new classes of COX-2 Inhibitors.Materials and Methods: In this study, three novel analogues of thiazolidin-4-ones derivatives 2a-c were synthesized. The ability of these compounds to inhibit ovine COX-1 and COX-2 (0.2- 0.8 μM) was determined using a colorimetric method. The cytotoxic effect of the synthesized compounds (25-100 mM) was also investigated by measuring their cytotoxicity against Caco-2 and MCF-7 cell lines using MTT assay. Cell apoptosis was determined by flow cytometry. Writhing test (7.5-75 mg/kg) was used to examine the antinociceptive effects in mice. The effect of the analogues against acute inflammation (7.5-75 mg/kg) was also studied using xylene-induced ear edema test in mice.Results: The synthesized compounds showed a weak capacity to inhibit the proliferation of Caco-2 and MCF-7 cell lines. The COX-2 inhibition potency and selectivity index for test compounds 2a–b were as follows; celecoxib>2b>2a. On the other hand, all three analogues exhibited strong antinociceptive activity against acetic acid-induced writhing. The anti-inflammatory and antinociceptive effects of the analogues were markedly more than positive control, celecoxib.Conclusion: This study demonstrates that the antinociceptive and anti-inflammatory activity profiles exhibited by the novel synthesized compounds are independent from their COX-2 inhibitory potencies. The found antinociceptive and anti-inflammatory effects can be caused by interaction with other target; independent from COX-2. Accordingly, the compounds 2a-c could serve as lead compounds to develop novel anti-inflammation and antinociceptive drugs.

Objective (s): Although bacteria and molds are the pioneering microorganisms for production of many enzymes, yet yeasts provide safe and reliable sources of enzymes with applications in food and feed.Materials and Methods: Single xylanase producer yeast was isolated from plant residues based on formation of transparent halo zones on xylan agar plates. The isolate showed much greater endo-1, 4-b-xylanase activity of 2.73 IU/ml after optimization of the initial extrinsic conditions. It was shown that the strain was also able to produce b -xylosidase (0.179 IU/ml) and α-arabinofuranosidase (0.063 IU/ml). Identification of the isolate was carried out and the endo-1, 4- b -xylanaseproduction by feeding the yeast cells on agro-industrial residues was optimized using one factor at a time approach.Results: The enzyme producer strain was identified as Aureobasidiumpullulans. Based on the optimization approach, an incubation time of 48 hr at 27oC, inoculum size of 2% (v/v), initial pH value of 4 and agitation rate of 90 rpm were found to be the optimal conditions for achieving maximum yield of the enzyme. Xylan, containing agricultural residues, was evaluated as low-cost alternative carbon source for production of xylanolytic enzymes. The production of xylanase enzyme in media containing wheat bran as the sole carbon source was very similar to that of the medium containing pure beechwoodxylan.Conclusion: This finding indicates the feasibility of growing of A. pullulans strain SN090 on wheat bran as an alternate economical substrate in order for reducing the costs of enzyme production and using this fortified agro-industrial byproduct in formulation of animal feed.

Objective (s): The major antibiotic efflux pump of Esherichia coli is AcrAB-TolC. The first part of the pump, AcrAB, is encoded by acrAB operon. The expression of this operon can be kept elevated by overexpression of an activator, MarA following inactivation of MarR and AcrR repressors due to mutation in encoding genes, marR and acrR, respectively. The aims of this research were to use E. coli mutants with or without mutation in marR to search for the presence of possible mutation in acrR and to quantify the expression of acrAB.Materials and Methods: The DNA binding region of acrR gene in these mutants were amplified by PCR and sequenced. The relative expression of acrA and acrB were determined by real time PCR.Results: Results showed that W26 and C14 had the same mutation in acrR, but none of the mutants overexpressed acrA and acrB in comparison with wild type strain.Conclusions: The effect of marR or acrR mutation on acrAB overexpression is dependent on levels of resistance to tetracycline and ciprofloxacin.

Objective (s): Microarrays are potential analyzing tools for genomics and proteomics researches, which is in needed of suitable substrate for coating and also hybridization of biomolecules.Materials and Methods: In this research, a thin film of oxidized agarose was prepared on the glass slides which previously coated with poly-L-lysine (PLL). Some of the aldehyde groups of the activated agarose linked covalently to PLL amine groups; also bound to the amino groups of biomolecules. These linkages were fixed by UV irradiation. The prepared substrates were compared to only agarose-coated and PLL-coated slides.Results: Results on atomic force microscope (AFM) demonstrated that agarose provided three-dimensional surface which had higher loading and bindig capacity for biomolecules than PLL-coated surface which had two-dimensional surface. In addition, the signal-to-noise ratio in hybridization reactions performed on the agarose-PLL coated substrates increased two fold and four fold compared to agarose and PLL coated substrates, respectively.Conclusion: The agarose-PLL microarrays had the highest signal (2546) and lowest background signal (205) in hybridization, suggesting that the prepared slides are suitable in analyzing wide concentration range of analytes.

Objective (s): Fascioliasis is a zoonotic parasitic disease caused by liver fluke species of Fasciola hepatica and Fasciola gigantica. Differentiation of these two species, based on their morphological characteristics, is difficult. The current study aimed to use PCR-RFLP assay to distinguish between F. hepatica and F. gigantica, based on profiles of RFLP, produced by effect of endonucleases on ITS2 of the ribosomal DNA genes from these two species.Materials and Methods: Adult Fasciola spp. were isolated from bile duct of naturally infected animals. The species of Fasciola were confirmed by sequencing the 505 bp region of the ITS2 gene in the isolates. By running the sequences of the samples in NEBcutter, suitable restriction enzymes (MspI and KpnI) were selected. Eight F. gigantica and eighteen F. hepatica samples were evaluated.Results: While RFLP pattern with MspI produced a profile by which it was difficult to differentiate these two species, KpnI along with MspI, produced a consistent pattern of a 231, 212 and 93 bp fragments in F. hepatica. This pattern was not seen in F. gigantica.Conclusion: Findings of this study demonstrated that RFLP with KpnI and MspI produce a suitable pattern which simply differentiates F. hepatica from F. gigantica.

Objective (s): Neuroinflammation in Parkinson disease (PD) is associated with glial cells activation and production of different inflammatory cytokines. In this study, we investigated the effect of chronic administration of 8-OH-DPAT on 6-OHDA-induced catalepsy and levels of inflammatory cytokines in cerebrospinal fluid (CSF).Materials and Methods: Catalepsy was induced by unilateral infusion of 6-OHDA (8 mg/2 ml/rat) into the central region of the sabstantia nigra pars compacta (SNc) being assessed by the bar-test, 5, 60, 120 and 180 min after intraperitoneal (IP) administration of 8-OH-DPAT (5-HT1A receptor agonist; 0.25, 0.5 and 1mg/kg, IP for 10 days). CSF samples were collected on the tenth day of 8-OH-DPAT administration and analyzed by ELISA method to measure levels of TNF-a, IL-1b and IL-6.Results: Chronic injection of 8-OH-DPAT decreased catalepsy in a dose dependent manner when compared with the control group. The most anti-cataleptic effect was observed at the dose of 1 mg/kg of 8-OH-DPAT. Levels of TNF-a in CSF increased three weeks after 6-OHDA injection while there was a significant decrease in TNF-a level of parkinsonian animals treated with 8-OH-DPAT (1 mg/kg, IP for 10 days). IL-1 b and IL-6 decreased and increased in parkinsonian rats and in 8-OH-DPAT-treated parkinsonian rats, respectively.Conclusion: Our study indicated that chronic administration of 8-OH-DPAT improves catalepsy in 6- OHDA-induced animal model of PD and restores central concentration of inflammatory cytokines to the basal levels.5-HT1A receptor agonists can be suggested as potential adjuvant therapy in PD by modulation of cerebral inflammatory cytokines.

Objective (s): Protein kinase C (PKCα) is involved in modulating articular chondrocytes apoptosis induced by nitric oxide (NO). Hyaluronic acid (HA) inhibits nitric oxide-induced apoptosis of articular chondrocytes by protecting PKCα, but the mechanism remains unclear. The present study was performed to investigate the effects and mechanisms of PKCα regulate protective effect of hyaluronic acid.Materials and Methods The ratio of apoptotic cell and cell viability was surveyed by PCNA and MTT assay. The expression of caspase-3 was determined by real-time PCR and western blot.Results: It was showed that HA was able to reduce the nuclei fragment and PCNA expression, and NO-induced articular apoptosis blocked by HA, pretreated chondrocytes with PMA, HA significantly inhibits the activation of caspase-3 induced by NO, but pretrement with CHR, HA significantly incresed the expression of caspase-3.Conclusion: The results may be showed that PKCa regulate the expresion of caspase-3, which contribute to the apoptosis of chondrocytes induced by NO. PKC α agonists enhance the protective effect of hyaluronic acid on nitric oxide-induced articular chondrocytes apoptosis.

Objective (s): The aim of the present study is to determine the effect of Chloramphenicol (CAP) on rat liver and small intestine. Effect of phenobarbital (PB) on CAP toxicity was also investigated.Materials and Methods: Rats were received CAP at doses of 0, 200, 400 and 600 mg/kg. Another group was pretreated with 80 mg/kg PB 30 min prior to administration of various doses of CAP. The experiment was repeated for seven consecutive days. Blood was collected for determination of serum aspartate aminotransferase (AST) alanine aminotransferase (ALT). The liver and small intestine tissues were processed for light microscopy.Results: CAP induced a dose dependent elevation of AST and ALT and produced injury in the liver and small intestine when compared to control animals. PB markedly decreased AST and ALT levels and protected liver and small intestine against CAP-induced toxicity.Conclusion: This study suggested rat liver and small intestine have potential to bioactivate CAP.