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921.
Artificial neural networks (ANNs) were used in this study to determine factors that control the polydispersity index (PDI) in an acetaminophen nanosuspension which was prepared using nanoprecipitation in microfluidic devices. The PDI of prepared formulations was measured by dynamic light scattering. Afterwards, the ANNs were applied to model the data. Four independent variables, namely, surfactant concentration, solvent temperature, and flow rate of solvent and antisolvent were considered as input variables, and the PDI of acetaminophen nanosuspension was taken as the output variable. The response surfaces, generated as 3D graphs after modeling, were used to survey the interactions happening between the input variables and the output variable. Comparison of the response surfaces indicated that the antisolvent flow rate and the solvent temperature have reverse effect on the PDI, whereas solvent flow rate has direct relation with PDI. Also, the effect of the concentration of the surfactant on the PDI was found to be indirect and less influential. Overall, it was found that minimum PDI may be obtained at high values of antisolvent flow rate and solvent temperature, while the solvent flow rate should be kept to a minimum. 相似文献
922.
Most mitochondrial mRNAs in trypanosomatid parasites require uridine insertion/deletion RNA editing, a process mediated by guide RNA (gRNA) and catalyzed by multi-protein complexes called editosomes. The six oligonucleotide/oligosaccharide binding (OB)-fold proteins (KREPA1-A6), are a part of the common core of editosomes. They form a network of interactions among themselves as well as with the insertion and deletion sub-complexes and are essential for the stability of the editosomes. KREPA4 and KREPA6 proteins bind gRNA in vitro and are known to interact directly in yeast two-hybrid analysis. In this study, using several approaches we show a minimal interaction surface of the KREPA4 protein that is required for this interaction. By screening a series of N- and C-terminally truncated KREPA4 fragments, we show that a predicted α-helix of KREPA4 OB-fold is required for its interaction with KREPA6. An antibody against the KREPA4 α-helix or mutations of this region can eliminate association with KREPA6; while a peptide fragment corresponding to the α-helix can independently interact with KREPA6, thereby supporting the identification of KREPA4-KREPA6 interface. We also show that the predicted OB-fold of KREPA4; independent of its interaction with gRNA, is responsible for the stable integration of KREPA4 in the editosomes, and editing complexes co-purified with the tagged OB-fold can catalyze RNA editing. Therefore, we conclude that while KREPA4 interacts with KREPA6 through the α-helix region of its OB-fold, the entire OB-fold is required for its integration in the functional editosome, through additional protein-protein interactions. 相似文献
923.
Mohsen Tehrani Abdol-Reza Varasteh Mohammad Reza Khakzad Majid Mirsadraee Mojtaba Sankian 《Reports of Biochemistry & Molecular Biology》2012,1(1):30-36
Background:
Recently, reports have indicated a role for the membrane form of Toll-like Receptor 2 (TLR2) in asthma pathogenesis. In this study we examined soluble TLR2 levels in serum and sputum of asthmatic and healthy subjects.Methods:
Serum and sputum samples were obtained from 33 asthmatic and 19 healthy subjects. The asthmatics were classified into four groups according to the Global Initiative for Asthma. A sandwich ELISA was developed to measure soluble TLR2 (sTLR2) in serum and sputum. TLR2 mRNA expression was determined by semi-quantitative RT-PCR of all sputum samples.Results:
The mean sTLR2 levels from serum and sputum of asthmatics were significantly lower than those from healthy subjects. Moreover, sTLR2 concentration decreased concomitantly with asthma severity. The differences observed, however, were not statistically significant. TLR2/GAPDH mRNA of sputum leukocytes was also significantly lower in asthmatics than in healthy subjects.Conclusion:
This study demonstrated for the first time thatsTLR2 levels are lower in serum and sputum samples from asthmatic than from healthy subjects, and this could be an indicator of TLR2 expression. We also found that sTLR2 concentration in serum decreased concomitantly with an increase of asthma severity clinical score. Key Words: Asthma, Expression, TLR2 mRNA, Soluble Toll-like receptor 相似文献924.
The frequency and distribution of thiopurine S-methyltransferase alleles in south Iranian population
Moini M Ghaderi F Sagheb MM Tavasolli AR Azarpira N Darai M Geramizadeh B 《Molecular biology reports》2012,39(4):4581-4587
Thiopurine methyltransferase (TPMT) catalyzes the S-methylation of thiopurine drugs such as 6-mercaptopurine, 6-thioguanine,
and azathiopurine. Variability in TPMT activity is mainly due to genetic polymorphism. The frequency of the four allelic variants
of the TPMT gene, TPMT*2 (G238C), TPMT*3A (G460A and A719G), TPMT*3B (G460A) and TPMT*3C (A719G) were determined in an Iranian
population from south of Iran (n = 500), using polymerase chain reaction (PCR)-RFLP and allele-specific PCR-based assays. Four hundred seventy four persons
(94.8%) were homozygous for the wild type allele (TPMT*1/*1) and twenty five people were TPMT*1/*3C (5%). One patient was found to be heterozygous in terms TPMT*1 and *2 alleles
with genotype of TPMT*1/*2 (0.2%). None of the participants had both defective alleles. The TPMT*3C and *2 were the only variant
alleles observed in this population. The total frequency of variant alleles was 2.6% and the wild type allele frequency was
97.4%. The TPMT*3B and *3A alleles were not detected. Distributions of TPMT genotype and allele frequency in Iranian populations
are different from the genetic profile found among Caucasian or Asian populations. Our findings also revealed inter-ethnic
differences in TPMT frequencies between different parts of Iran. This view may help clinicians to choose an appropriate strategy
for thiopurine drugs and reduce adverse drug reactions such as bone marrow suppression. 相似文献
925.
Rahimi Z Ahmadian Z Akramipour R Vaisi-Raygani A Rahimi Z Parsian A 《Molecular biology reports》2012,39(3):2195-2200
In order to determine the influence of polymorphism in thymidylate synthase (TS 28-bp repeat) and methionine synthase (MS
A2756G) genes on the susceptibility to acute lymphoblastic leukemia (ALL), 73 children with ALL and 128 age and sex matched
unrelated healthy individuals from the Kermanshah Province of Iran were screened. The genotyping of TS 28-bp repeat and MS
A2756G polymorphisms were performed by polymerase chain reaction (PCR) and PCR–RFLP, respectively. The frequency of TS 2R
allele in patients and controls were 41.5 and 38%, respectively (Odds ratios (OR) = 1.13, 95%CI 0.73–1.74, P = 0.56). The allelic frequency of G allele of MS was higher (25%) in patients compared with healthy subjects (23%) (OR = 1.09,
95%CI 0.67–1.75, P = 0.71). Considering MS AA and TS 3R3R genotypes as reference indicated that individuals with MS GG + TS 2R2R genotypes have
1.3-fold increase in the risk of ALL (OR = 1.3, 95%CI 0.6–2.7, P = 0.5). Our results showed that neither TS 28-bp repeat nor MS A2756G polymorphisms are risk factors for susceptibility to
ALL in Western Iran. 相似文献
926.
Two cases of dermatophytosis caused by Microsporum vanbreuseghemii are reported. A 7-year-old boy and his brother were examined for tinea capitis. Hair samples and skin scrapings were collected from each patient to microscopy and culture. Direct microscopic examination of the hairs using lactophenol revealed an ectothrix invasion. Cultures inoculated with portions of clinical material yielded M. vanbreuseghemii after 2?weeks. The identification of the fungi were based on colony morphology on mycobiotic agar, microscopic characteristic on slide cultures, biochemical reactions and hair perforation tests. 相似文献
927.
Hamid Reza Karimi Mahbubeh Hajizadeh Hossin Abadi Azam Maleki Kohbanani 《Plant Systematics and Evolution》2012,298(5):963-968
The aim of this research was to study the genetic diversity of Pistacia khinjuk Stocks. and also to reveal the genetic relationships. Leaf morphological characters of 16 genotypes together with Randomly
Amplified Polymorphic DNA (RAPD) marker data were used for this purpose. Leaf morphological characters were used for factor
analysis, which determined four main factors. Grouping of genotypes by these factors was performed by Ward’s method. Fifteen
primers produced a total of 146 fragments, with an average of 9.73 fragments per primer, of which 129 were polymorphic. The
unweighted pair group method based on arithmetic average (UPGMA) analysis was performed on Jaccard’s similarity coefficient
matrix. According to RAPD data, genotypes were separated into three groups. The first contained the genotypes with round leaflets.
Genotypes with three lanceolate leaflets were located in the second and third groups, respectively. This study revealed that
high diversity exists among genotypes of P. khinjuk, like in P. vera. Also it could be postulated that genotypes of P. khinjuk with oblique and lanceolate leaflets are probably descendents of the genotypes with acuminate and roundish leaflets. 相似文献
928.
Sheikhzadeh N Panchah IK Asadpour R Tayefi-Nasrabadi H Mahmoudi H 《Animal reproduction science》2012,130(1-2):119-123
The aim of this study was to clarify the effects of dietary Haematococcus pluvialis (H.p) on reproductive performance in female rainbow trout and egg quality in terms of antioxidant system and biochemical parameters. 60 rainbow trout (2475.5 ± 64.4 g) were randomly assigned to 2 groups in triplicates and fed diet containing 3 g H.p kg(-1) feed equivalent to 30 mg astaxanthin kg(-1) die or control diet for 30 days. On days 20 and 30 during feeding trial, mature fish were weighed and sampled for stripping. Results indicated that supplementation of H.p did not improve total egg weight, egg number per gram and fecundity. There were few changes in triglyceride and total protein content in fish eggs. Level of glucose decreased markedly on day 30 while on day 20 of feeding trial, a non-significant decrease was shown in treatment group. On day 20, the level of malondialdehyde (MDA) indicating lipid peroxidation product significantly decreased in eggs of the treatment group. The activities of enzymes of the antioxidant system did not change during this study, even though slight increase in glutathione peroxidase in treatment group was revealed during this study. In conclusion, this study showed that female rainbow trout appear to benefit from inclusion of H.p in diet during their reproductive stages in terms of improved egg quality. 相似文献
929.
Amiri R Bordbar AK Laurents DV Khosropour AR Mohammadpoor-Baltork I 《International journal of biological macromolecules》2012,50(4):1151-1157
The thermal stability and enzymatic activity of bovine pancreatic ribonuclease A (RNase A) have been investigated in the presence of a homologous series of cationic gemini surfactants (alkanediyl-α,ω-bis(hydroxyethyl methyl hexadecyl ammonium bromide)). UV, circular dichorism and fluorescence spectroscopies have been used for this study. The denaturation curves at various surfactant concentrations were analyzed on basis of a two-transition model to obtain values of T(m) (temperature at the midpoint of denaturation) and ΔH(m) (enthalpy change at T(m)) of each transition. The main conclusion of this study is that these cationic gemini surfactants slightly activate and stabilize RNase A below their critical micelle concentrations at pH 5.0. The cationic gemini surfactant with the shorter spacer interacts more efficiently with RNase A than those with longer spacers. 相似文献