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Organophosphorus (OP) compounds are one of the most hazardous chemicals used as insecticides/pesticide in agricultural practices. A large variety of OP compounds are hydrolyzed by organophosphorus hydrolases (OPH; EC 3.1.8.1). Therefore, OPHs are among the most suitable candidates that could be used in designing enzyme-based sensors for detecting OP compounds. In this work, a novel nanobiosensor for the detection of paraoxon was designed and fabricated. More specifically, OPH was covalently embedded onto chitosan and the enzyme-chitosan bioconjugate was then immobilized on negatively charged gold nanoparticles (AuNPs) electrostatically. The enzyme was immobilized on AuNPs without chitosan as well, to compare the two systems in terms of detection limit and enzyme stability under different pH and temperature conditions. Coumarin 1, a competitive inhibitor of the enzyme, was used as a fluorogenic probe. The emission of coumarin 1 was effectively quenched by the immobilized Au-NPs when bound to the developed nanobioconjugates. However, in the presence of paraoxon, coumarin 1 left the nanobioconjugate, leading to enhanced fluorescence intensity. Moreover, compared to the immobilized enzyme without chitosan, the chitosan-immobilized enzyme was found to possess decreased Km value by more than 50%, and increased Vmax and Kcat values by around 15% and 74%, respectively. Higher stability within a wider range of pH (2-12) and temperature (25-90°C) was also achieved. The method worked in the 0 to 1050 nM concentration ranges, and had a detection limit as low as 5 × 10(-11) M.
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Técnicas Biossensoriais , Quitosana/química , Enzimas Imobilizadas/metabolismo , Ouro/química , Nanopartículas Metálicas/química , Nanotecnologia , Paraoxon/análise , Monoéster Fosfórico Hidrolases/metabolismo , Estabilidade Enzimática , Concentração de Íons de Hidrogênio , Cinética , Microscopia Eletrônica de Varredura , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier , TemperaturaRESUMO
Passive smoking during pregnancy leads to adverse effects on mother and infant. The present investigation was designed to evaluate the association between maternal reported passive smoking with the cotinine concentration of maternal urine and umbilical cord blood at delivery and to determine the accuracy of maternal reporting of exposure to cigarette smoke during pregnancy. This was a cross-sectional study. From the 108 non-smoker pregnant women who were referred for delivery, 54 were passive smokers. Urine samples were collected from the mothers in the delivery room and blood samples after birth were taken from the umbilical cord. Passive smoking was evaluated through questionnaire and cotinine level of urine and umbilical cord blood. The geometric mean cotinine concentration of the maternal urine and the umbilical cord serum were, respectively, 27.4 ± 29.96 ng/mL and 3.71 ± 1.22 ng/mL in the exposed group (P < 0.001) and 0.75 ± 2.29 and 0.40 ± 0.63 in the non-exposed group (P < 0.001). There was a statistically significant correlation between maternal urinary and umbilical cord serum level of cotinine (P < 0.001, r = 0.58). Significant associations were shown between maternal reports of exposure to cigarette smoking with cotinine level of urine (kappa = 96%) and umbilical cord (kappa = 98%) (P < 0.001). This study shows that the pregnant woman's report of passive smoking during pregnancy in Iran is accurate. The questionnaire is an appropriate method to evaluate smoke exposure and could replace cotinine measurement.
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Cotinina/sangue , Exposição Materna/efeitos adversos , Fumar/efeitos adversos , Poluição por Fumaça de Tabaco/efeitos adversos , Adulto , Biomarcadores/sangue , Biomarcadores/urina , Cotinina/urina , Estudos Transversais , Exposição Ambiental/efeitos adversos , Feminino , Sangue Fetal , Humanos , Troca Materno-Fetal , Gravidez , Autorrelato , Adulto JovemRESUMO
The plasmodiophoromycete Polymyxa betae and P. graminis are eukaryotic biotrophic parasites residing in the roots of chenopodiacae and gramineae plants. They are natural transmitting agents of several important plant viruses such as are beet necrotic yellow vein virus (BNYW), beet soil borne mosaic virus (BSBMV), wheat soil-borne mosaic virus (WSBMV). Developing advanced high-throughput diagnostic methods capable of accurate detection of these pathogens could assist with the screening programs and consequently with the development of disease-resistant germplasms. In the present study, a previously developed quantum dots (QDs) FRET-based nano-biosensor was upgraded to a high-throughput version. QDs were functionalized with a specific antibody against the P. betae's specific glutathione-S-transferase (GST) protein. On the other hand, GST was conjugated to Rhodamine dye. Ninety six-well polystyrene plates were used as the detection platform. The mutual affinity of the antigen and the antibody brought the CdTe QDs and rhodamine together close enough to allow the resonance dipole-dipole coupling required for fluorescence resonance energy transfer (FRET) to occur. The immunosensor constructed showed a high sensitivity and specificity of 100%, and was successfully used for high-throughput screening of 96 real samples with consistent results within the course of less than 30 minutes.
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Técnicas Biossensoriais/instrumentação , Plasmodioforídeos/isolamento & purificação , Pontos Quânticos , Técnicas Biossensoriais/economia , Técnicas Biossensoriais/métodos , Fatores de TempoRESUMO
INTRODUCTION: The objective of this study was to assess whether counseling both mothers and fathers reduces their infants' exposure to secondhand smoke (SHS). METHODS: Participants were 130 nonsmoking children aged less than 1 year, exposed to their fathers' or mothers' smoking, and recruited from a health center in southern Tehran. Eligible families were randomly assigned to intervention or control group. Infant urine samples were collected, and parents were interviewed at baseline and at a 3-month follow-up in each of the 2 groups. Mothers of the intervention group were provided 3 counseling sessions, one of which was face to face and 2 of which were by telephone. Fathers were provided 3 counseling sessions by telephone. Parents were also given an educational pamphlet and a sticker depicting a smoke-free home. The control group received usual care. Changes in infant urinary cotinine levels, parental cigarette consumption in the presence of the child, and home- and car-smoking bans were assessed. RESULTS: The intervention was effective in reducing infant urinary cotinine levels (1-tailed p = .029). There was a greater decrease in the total daily cigarette consumption in the presence of the child in the intervention group compared with the control group, and the differences between the 2 groups were statistically significant (1-tailed p = .03). While the differences between home-smoking bans in the 2 groups were statistically significant (1-tailed p = .049), the differences between car-smoking bans did not reach significance. CONCLUSION: Counseling similar to that employed in other countries can reduce infant exposure to SHS, suggesting generalizability.
Assuntos
Aconselhamento , Pais/psicologia , Prevenção do Hábito de Fumar , Poluição por Fumaça de Tabaco/prevenção & controle , Adulto , Cotinina/urina , Feminino , Seguimentos , Educação em Saúde/métodos , Humanos , Lactente , Irã (Geográfico) , Masculino , Fumar/psicologia , Poluição por Fumaça de Tabaco/estatística & dados numéricosRESUMO
BACKGROUND AND AIMS: The reduced alpha1-antitrypsin (AAT) activities of some phenotypes have been suggested as contributing to the development of respiratory diseases. MATERIALS AND METHODS: One hundred patients with respiratory disease following exposure to sulfur mustard were divided into two groups of 50 based on their respiratory symptoms and compared with a healthy control group. AAT phenotypes were determined in the plasma of all patient and control subjects by isoelectric focusing (IEF). RESULTS: Mean AAT activities in patient and control groups were 3.4 +/- 0.3 and 4.2 +/- 0.1 micromol min(-1) ml(-1), respectively (p < 0.001). No phenotypic alterations were detected. CONCLUSIONS: The difference in the clinical pulmonary symptoms of the two groups was attributed to reduced AAT activity, but this was not manifested as phenotypic changes identifiable by IEF.
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Gás de Mostarda/toxicidade , Transtornos Respiratórios/etiologia , Deficiência de alfa 1-Antitripsina/complicações , alfa 1-Antitripsina/sangue , Adulto , Estudos de Casos e Controles , Substâncias para a Guerra Química , Feminino , Humanos , Irã (Geográfico) , Focalização Isoelétrica , Masculino , Pessoa de Meia-Idade , Fenótipo , Transtornos Respiratórios/induzido quimicamente , Transtornos Respiratórios/epidemiologiaRESUMO
The aim of this study was to obtain a stable sunflower oil-in-water (O/W) Pickering emulsion stabilized by chitosan (CS)-stearic acid (SA) nanogels and to compare the oxidative stability of the sunflower Pickering emulsion stabilized by CS-SA nanogels with sunflower oil emulsion stabilized by Tween 80. The results of the scanning electron microscopy revealed that by increasing the SA to CS ratio, the uniformity of particles was increased. Also, the results showed that the emulsions with pH of 8, SA to CS ratio of 0.5:1, and oil-to-nanogel ratio of 20:1 had the highest stability and minimum droplet size. In the following, the oxidative stability of the most favorable Pickering emulsion and the Tween 80-stabilized emulsion was evaluated and compared using the peroxide and thiobarbituric acid tests. The findings implied that the O/W emulsion stabilized by CS-SA nanogels had a higher oxidative stability than the O/W emulsion stabilized by Tween 80.
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Infectious bursal disease virus is a causative agent of one of the most important disease which causes frequent tragic disaster in the poultry industry all over the world. Therefore, in the present study a new fluorescence resonance energy transfer-based technique was developed to detect VP2 gene of infectious bursal disease virus using two oligonucleotide probes labeled with quantum dots and rhodamine- immobilized gold nanoparticles (AuNPs-Rh). Quantum dots labeled with an amino-modified first oligonucleotide, and AuNPs-Rh labeled with thiol-modified second oligonucleotides were added to the DNA targets upon which hybridization occurred. In the presence of target the AuNPs-Rh will be located in the vicinity of the quantum dots and leads to the fluorescence resonance energy transfer to be occurred and subsequently the fluorescence intensity of quantum dots was stimulated. The immobilization of rhodamine to the surface of AuNPs increased the fluorescence intensity of rhodamine. The maximum fluorescence resonance energy transfer efficiency for the developed sensor is monitored at a quantum dots-PA/AuNPs-Rh-PT molar ratio of 1:10. Moreover, the feasibility of the developed nanobiosensor was demonstrated by the detection of a synthetic 49-mer nucleotide derived from infectious bursal disease virus and the limit of detection was estimated as 3â¯×â¯10-8â¯M. The developed DNA detection scheme is a simple, rapid and efficient technique which does not need excessive washing and separation steps.
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Transferência Ressonante de Energia de Fluorescência/métodos , Ouro/química , Vírus da Doença Infecciosa da Bursa/isolamento & purificação , Nanopartículas Metálicas/química , Pontos Quânticos/química , Rodaminas/química , Compostos de Cádmio/química , Telúrio/químicaRESUMO
This study was set to prepare a new active film by using a biodegradable bio-based source, i.e., corn starch. To achieve that, benzoic acid (BA) and chitosan (CS) were covalently bound and CS-BA nanogel was then obtained using self-assembly method. Subsequently, rosemary essential oil (REO) was encapsulated in CS-BA nanogel. Finally, REO in both free and encapsulated forms were incorporated in starch-carboxy methyl cellulose (CMC) films and their physical, mechanical and antimicrobial properties were studied. The films incorporating CS-BA nanogel had a higher water vapor permeability compared with the films containing REO. Moreover, film containing 0.2% CS-BA nanogel had the highest transparency and tensile strength. The REO and nanogel alone had inhibitory effects against Staphylococcus aureus (S. aureus) and by encapsulation, the inhibitory effect of REO was increased. By encapsulating REO in nanogel, both immediately (REO) and gradual (Nanogel) antimicrobial effect against S. aureus in the starch-CMC suspensions were obtained.
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Anti-Infecciosos/química , Carboximetilcelulose Sódica/química , Óleos Voláteis/química , Amido/química , Anti-Infecciosos/farmacologia , Carboximetilcelulose Sódica/farmacologia , Quitosana/química , Quitosana/farmacologia , Embalagem de Alimentos , Humanos , Nanogéis , Polietilenoglicóis/química , Polietilenoglicóis/farmacologia , Polietilenoimina/química , Polietilenoimina/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/patogenicidade , Amido/farmacologia , Vapor , Resistência à TraçãoRESUMO
BACKGROUND: Neuroserpin, a member of the Serine Proteinase Inhibitor (Serpin) superfamily, is known to be a neuroprotective factor in the focal ischemic stroke followed by reducing the microglial activation. Neuroserpin is a protein rich of methionine residues that can scavenge the free radical species which may increase its neuroprotective effect. On the other hand, the oxidative modifications of the amino acid residues in neuroserpin may lead to changes in its conformation and function. In this study, it was investigated the changes in the conformation and the function of the oxidized neuroserpin. METHODS: Neuroserpin expressed in E. coli, BL21 or M15 harboring plasmid pQE81L containing neuroserpin cDNA. Expressed neuroserpin was purified by resin sulfopropyl A50 precharged with 0.1 M NiSO4 under denaturing condition. Neuroserpin was oxidized under oxidative stress condition in the presence of different concentration of hydrogen peroxide. The oxidation of neuroserpin was conveniently detected by a carbonyl content assay using 2, 4 dinitrophenylhydrazine. Changes in tertiary structure of neuroserpin were monitored by spectrofluorimeter to study the alteration of intrinsic fluorescence and also fluorescence of 8-anilinonaphthalin-1 sulfonic acid (ANS) in native and oxidized form of neuroserpin. RESULTS: Total expressed neuroserpin was estimated 4-5 mg/lit in 2XYT culture media. SDS-PAGE analysis of purified neuroserpin showed a single band which reflects the efficiency of the resin SP A50 for purification of the proteins containing 6xHis tag. Carbonyl content of oxidized and native neuroserpin was estimated 12.3 +/- 0.3 and 0.45 +/- 0.05, respectively. The inhibitory activity of oxidized neuroserpin decreased up to 40-60% as compared with native form of neuroserpin. Intrinsic fluorescence and also the emission of ANS bind to the hydrophobic region of the protein altered from 380 to 85 and in the case of ANS from 105 to 150 in oxidized and native form of neuroserpin, respectively. CONCLUSION: The decreased intrinsic fluorescence intensity, an enhancement in the fluorescence of ANS, and loss of the inhibitory activity up to 40-60% in neuroserpin, all suggested a conformational modification in the protein under the oxidative stress condition. Remaining the inhibitory activity of neuroserpin reflects that the protein tolerates the oxidative stress condition effectively.
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Neuropeptídeos/química , Neuropeptídeos/metabolismo , Serpinas/química , Serpinas/metabolismo , Escherichia coli/genética , Humanos , Interações Hidrofóbicas e Hidrofílicas , Técnicas In Vitro , Oxirredução , Estresse Oxidativo , Conformação Proteica , Dobramento de Proteína , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Espectrometria de Fluorescência , NeuroserpinaRESUMO
BACKGROUND: Molecular chaperon-like activity for protein refolding was studied using nanogel chitosan-myristic acid (CMA) and the protein neuroserpin (NS), a member of the serine proteinase inhibitor superfamily (serpin). MATERIALS AND METHODS: Recombinant his-tag fusion NS was expressed in Escherichia coli. For confirmation of refolding of the purified NS, structural analysis was performed by circular dichroism and spectrofluorometric along with its inhibitory activity, which was assayed by single-chain tissue plasminogen activator. For evaluating NS aggregation during preparation, the samples were separated on a 7.5% (w/v) nondenaturing polyacrylamide gel electrophoresis. MA and chitosan covalently join together by the formation of amide linkages through the 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide-mediated reaction. The morphology and size of the prepared CM nanogel were characterized by transmission electron microscopy and scanning electron microscopy. RESULTS: Heating at different temperatures (25°C, 37°C, 45°C, 65°C, 80°C) results in a further rise in ß-structures accompanied by a fall of helices and no significant change in random coils. Structural changes in NS in the presence of CMA nanogel were less than that in the absence of CMA nanogel. Mater nanogel effectively prevented aggregation of NS during temperature induced protein refolding by the addition of cyclodextrins. The nanogel activity resembled the host-guest chaperon activity. CONCLUSION: These conditions, called conformational disorders, include Alzheimer's, Parkinson's, Huntington's disease, the transmissible spongiform encephalopathies, prion diseases, and dementia. Nanogels can be useful in recovery of the structural normality of proteins in these diseases.
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Macrophages are effector cells in the innate and adaptive immune systems and in situ exist within three-dimensional (3-D) microenvironments. As there has been an increase in interest in the use of 3-D scaffolds to mimic natural microenvironments in vitro, this study examined the impact on cultured mice peritoneal macrophages using standard 2-D plates as compared to 3-D collagen-chitosan scaffolds. Here, 2-D and 3-D cultured macrophages were evaluated for responses to lipopolysaccharide (LPS), dexamethasone (Dex), BSA (bovine serum albumin), safranal (herbal component isolated from safranal [Saf]) and Alyssum homolocarpum mucilage (A. muc: mixed herbal components). After treatments, cultured macrophages were evaluated for viability, phagocytic activity and release of tumor necrosis factor (TNF)-α and interleukin (IL)-1ß pro-inflammatory cytokines. Comparison of 2-D vs 3-D cultures showed that use of either system - with or without any exogenous agent - had no effect on cell viability. In the case of cell function, macrophages cultured on scaffolds had increases in phagocytic activity relative to that by cells on 2-D plates. In general, the test herbal components Saf and A. muc. had more impact than any of the other exogenous agents on nanoparticle uptake. With respect to production of TNFα and IL-1ß, compared to the 2-D cells, scaffold cells tended to have significantly different levels of production of each cytokine, with the effect varying (higher or lower) depending on the test agent used. However, unlike with particle uptake, here, while Saf and A. muc. led to significantly greater levels of cytokine formation by the 3-D culture cells vs that by the 2-D plate cells, there was no net effect (stimulatory) vs control cultures. These results illustrated that collagen-chitosan scaffolds could provide a suitable 3-D microenvironment for macrophage phagocytosis and could also impact on the formation of pro-inflammatory cytokines.
Assuntos
Quitosana/imunologia , Colágeno/imunologia , Macrófagos/imunologia , Fagocitose , Alicerces Teciduais , Animais , Brassicaceae/imunologia , Células Cultivadas , Microambiente Celular , Quitosana/química , Colágeno/química , Citocinas/metabolismo , Feminino , Regeneração Tecidual Guiada , Humanos , Mediadores da Inflamação/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Nanoestruturas/química , Mucilagem VegetalRESUMO
Flagellin of Pseudomonas aeruginosa is an important vaccine candidate. N-terminal domains are highly conserved in both type a and type b flagellins. The efficacy of gold nanoparticles (AuNPs) conjugated to N-terminal domains of P. aeruginosa flagellin (flagellin(1-161)), as an immunogen in mice, has been assessed. The nanoparticles were conjugated to the recombinant protein through direct interaction of thiol molecules of the cysteines with AuNPs and formation of AuS bond. Flagellin(1-161), AuNP-flagellin(1-161), and flagellin(1-161) emulsified in Freund's adjuvant (FA: complete/incomplete Freund's adjuvant formulation) were administered subcutaneously to BALB/c mice. Mice given AuNP-flagellin(1-161) elicited high titers of anti-flagellin(1-161) antibodies compared with non-immune group and/or mice which received flagellin(1-161) without adjuvant. In whole cell ELISA, these antibodies effectively recognized the native flagellin on the bacteria. Opsonophagocytosis assay demonstrated the functional activity and specificity of anti-flagellin(1-161) antibodies raised by AuNP-flagellin(1-161) against homologous strain. All of the results were comparable with those obtained by use of FA. Taken together, this is the first report of conjugation of AuNPs to flagellin and evaluating its immune response against P. aeruginosa.
Assuntos
Adjuvantes Imunológicos/administração & dosagem , Flagelina/imunologia , Imunidade Humoral , Nanopartículas Metálicas/administração & dosagem , Animais , Anticorpos Antibacterianos/sangue , Células Cultivadas , Feminino , Adjuvante de Freund/administração & dosagem , Ouro , Lipídeos/administração & dosagem , Macrófagos/imunologia , Camundongos Endogâmicos BALB C , Fagocitose , Infecções por Pseudomonas/prevenção & controle , Pseudomonas aeruginosa , Proteínas Recombinantes/imunologiaRESUMO
Due to the low titer or uneven distribution of Citrus tristeza virus (CTV) in field samples, detection of CTV by using conventional detection techniques may be difficult. Therefore, in the present work, the cadmium-telluride quantum dots (QDs) was conjugated with a specific antibody against coat protein (CP) of CTV, and the CP were immobilized on the surface of gold nanoparticles (AuNPs) to develop a specific and sensitive fluorescence resonance energy transfer (FRET)-based nanobiosensor for detecting CTV. The maximum FRET efficiency for the developed nano-biosensor was observed at 60% in AuNPs-CP/QDs-Ab ratio of 1:8.5. The designed system showed higher sensitivity and specificity over enzyme linked immunosorbent assay (ELISA) with a limit of detection of 0.13µgmL(-1) and 93% and 94% sensitivity and specificity, respectively. As designed sensor is rapid, sensitive, specific and efficient in detecting CTV, this could be envisioned for diagnostic applications, surveillance and plant certification program.
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Citrus/virologia , Closterovirus/isolamento & purificação , Transferência Ressonante de Energia de Fluorescência/métodos , Doenças das Plantas/virologia , Anticorpos Imobilizados/química , Técnicas Biossensoriais/métodos , Compostos de Cádmio/química , Ouro/química , Limite de Detecção , Nanopartículas Metálicas/química , Pontos Quânticos/química , Telúrio/químicaRESUMO
Cancer is one of the main causes of mortality in the world which is created by the effect of enviromental physico-chemical mutagen and carcinogen agents. The identification of new cytotoxic drugs with low side effects on immune system has developed as important area in new studies of pharmacology. Thymoquinone (TQ), derived from the medicinal spice Nigella sativa (also calledt black cumin) exhibit anti-inflammatory and anti-cancer activities. In this study we employed nanogel-based nanoparticle approach to improve upon its effectiveness. Myristic acid-chitosan (MA-chitosan) nanogels were prepared by the technique of self-assembly. Thymoquinone was loaded into the nanogels. The surface morphology of the prepared nanoparticles was determined using SEM and TEM. The other objective of this study was to examine the in-vitro cytotoxic activity of cell death of Thymoquinone and nanothymoquinone on human breast adenocarcinoma cell line (MCF7). Cytotoxicity and viability of Thymoquinone and nanothymoquinone were assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and dye exclusion assay. Transmission electron microscopy confirmed the particle diameter was between 150 to 200 nm. Proliferation of MCF7 cells was significantly inhibited by Thymoquinone and nanothymoquinone in a concentration-dependent manner in defined times. There were significant differences in IC50 Thymoquinone and nanothymoquinone. TQ-loaded nanoparticles proved more effective compared to TQ solution. The high drug-targeting potential and efficiency demonstrates the significant role of the anticancer properties of TQ-loaded nanoparticles.
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Rapid detection of organophosphorous (OP) compounds such as paraoxon would allow taking immediate decision on efficient decontamination procedures and could prevent further damage and potential casualties. In the present study, a biosensor based on nanomagnet-silica core-shell conjugated to organophosphorous hydrolase (OPH) enzyme was designed for detection of paraoxon. Coumarin1, a competitive inhibitor of the OPH enzyme, was used as a fluorescence-generating molecule. Upon excitation of cumarin1 located at the active site of the enzyme, i.e., OPH, the emitted radiations were intensified due to the mirroring effect of the nanomagnet-silica core-shell conjugated to the enzyme. In presence of paraoxon and consequent competition with the fluorophore in occupying enzyme's active site, a significant reduction in emitted radiations was observed. This reduction was proportional to paraoxon concentration in the sample. The method worked in the 10- to 250-nM concentration range had a low standard deviation (with a coefficient of variation (CV) of 6-10%), and the detection limit was as low as 5 × 10(-6) µM.
Assuntos
Arildialquilfosfatase/química , Proteínas de Bactérias/química , Técnicas Biossensoriais/métodos , Nanopartículas de Magnetita/química , Paraoxon/análise , Pseudomonas/enzimologia , Dióxido de Silício/química , Cumarínicos/químicaRESUMO
OBJECTIVE: To explore the cumulative genotoxic damage to glioblastoma (GBM) cells, grown as multicellular spheroids, following exposure to 6 MV X-rays (2 Gy, 22 Gy) with or without, 2- methoxy estradiol (2ME2), iododeoxyuridine (IUDR) or topotecan (TPT), using the Picogreen assay. MATERIALS AND METHODS: The U87MG cells cultured as spheroids were treated with 6 MV X-ray using linear accelerator. Specimens were divided into five groups and irradiated using X-ray giving the dose of 2 Gy after sequentially incubated with one of the following three drug combinations: TPT, 2-ME2/TPT, IUDR/TPT or 2ME2/IUDR/ TPT. One specimen was used as the irradiated only sample (R). The last group was also irradiated with total dose of 22 Gy (each time 2 Gy) of 6 MV X-ray in 11 fractions and treated for three times. DNA damage was evaluated using the Picogreen method in the experimental study. RESULTS: R/TPT treated group had more DNA damage [double strand break (DSB)/single strand break (SSB)] compared with the untreated group (P<0.05). Moreover the R/ TPT group treated with 2ME2 followed by IUDR had maximum DNA damage in spheroid GBM indicating an augmented genotoxicity in the cells. The DNA damage was induced after seven fractionated irradiation and two sequential treatments with 2ME2/IUDR/TPT. To ensure accuracy of the slope of dose response curve the fractionated radiation was calculated as 7.36 Gy with respect to α/ß ratio based on biologically effective dose (BED) formulae. CONCLUSION: Cells treated with 2ME2/IUDR showed more sensitivity to radiation and accumulative DNA damage. DNA damage was significantly increased when GBM cells treated with TPT ceased at S phase due to the inhibition of topoisomerase enzyme and phosphorylation of Chk1 enzyme. These results suggest that R/TPT- treated cells increase sensitivity to 2ME2 and IUDR especially when they are used together. Therefore, due to an increase in the level of DNA damage (SSB vs. DSB) and impairment of DNA repair machinery, more cell death will occur. This in turn may improve the treatment of GBM.
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In this study, the chitosan magnetic core-shell nanoparticles (CMNPs) was synthesized and then used as a support for immobilization of lipase. The characteristics of CMNPs, including morphology, topography and spectra type before and after immobilization were determined. The scanning electron micrographs of the CMNPs showed that they were approximately uniform spheres and the distribution chart indicated that the particles have the mean diameter of 100 nm. Kinetic parameters of Km and Vm were calculated as 1.07 mM and 29.43 U/mg for free B. cepacia lipase and 1.29 mM and 25.82 U/mg for immobilized lipase on CMNPs, respectively. The activity of immobilized lipase was 32 U/mg under optimum temperature and pH. CMNP's were used in trasesterification reaction in order to evaluate the activity of the immobilized enzyme compared to the free enzyme. Immobilization of lipase on CMNPs improved stability and total relative activity of the enzyme. It could be concluded that CMNPs be considered as a suitable carrier for enzyme immobilization.
Assuntos
Burkholderia cepacia/enzimologia , Quitosana/química , Quitosana/síntese química , Estabilidade Enzimática , Enzimas Imobilizadas , Lipase , Nanopartículas de Magnetita , Enzimas Imobilizadas/química , Esterificação , Concentração de Íons de Hidrogênio , Lipase/química , Microscopia Eletroquímica de Varredura , TemperaturaRESUMO
Mother's and infant exposure to cigarette smoke is one of the most important public health problems. There is no study in Iran evaluating the impact of cigarette smoke on infant growth and development. The purpose of this study was to determine the effects of cigarette. This prospective cohort study was conducted on 51 cigarette smoke-exposed infants (exposed group) and 51 non-exposed infants (non-exposed group). They were evaluated for weight, height and head circumference three times; five to seven days, two months and four months after birth. Urine samples were also collected in each turn. Exposure to secondhand smoke was assessed through questionnaires and urinary cotinine levels. The analysis was performed using an independent t-test, Mann-Whitney U test, chi-square and Fisher's exact and Kappa tests. Mean urinary cotinine level in the exposed group was 38.57±2.85 ng/mg creatinine at baseline, 86.95±1.16 at two months and 63.32±2.08 at four months of age. These indicated a gradual reduction of exposure from two to four months. The weight and height of the exposed group were significantly lower than the non-exposed group (P< 0.001) at two and four months after birth. The results of the present study showed that the exposure to secondhand smoke during infancy may lead to weight and height growth reduction in the first four months of life.
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Desenvolvimento Infantil , Pais/psicologia , Poluição por Fumaça de Tabaco/efeitos adversos , Adulto , Peso Corporal , Cotinina/urina , Feminino , Seguimentos , Humanos , Recém-Nascido/crescimento & desenvolvimento , Irã (Geográfico) , Masculino , Estudos Prospectivos , Inquéritos e Questionários , Poluição por Fumaça de Tabaco/prevenção & controleRESUMO
Human Telomerase Reverse Transcriptase (hTERT) gene is expressed in all types of cancers, and it is considered as unique biomarker for early detection, monitoring and prognosis of different cancers. Routinely, the main techniques for detection of hTERT gene expression are based on enzymatic amplifications which need specified equipments, expert personnel and high cost and time. With regarding to the clinical importance of analysis of hTERT gene expression, we have developed a rapid, simple and low cost method which detects hTERT RNA target in 5 µl reaction scale using gold nanoprobes. The method is based on the inhibition of nanoparticle aggregation in the presence of MgCl 2 and it can be used as a basic technique for development of clinical scale gold nanoprobe nanobiodiagnostics for detection of hTERT gene expression with a limit of detection at fmol/µl concentrations.
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BACKGROUND: Exposure to cigarette smoke during pregnancy leads to several adverse effects on mother and child. The purpose of this study was to evaluate the effect of being a passive smoker during pregnancy on vitamin D level and related biochemical indices including parathyroid hormone, calcium, phosphorus and alkaline phosphatase in mothers and newborns. METHODS: One hundred eight pregnant women and their newborns participated in a historical cohort study in two equal groups (n = 54) with and without cigarette smoke exposure. Maternal blood and urine samples and blood samples of umbilical cord were obtained in the delivery room. Concentration of 25-hydroxy vitamin D and related biochemical indices in samples of maternal and cord blood were investigated. Exposure to cigarette smoke was evaluated through questionnaire and maternal urine and umbilical cord serum cotinine levels. RESULTS: The mean level of 25-hydroxyvitamin D in maternal serum was 9.28 ± 5.19 ng/mlin exposed and 10.75 ± 5.26 ng/ml in non-exposed group(p > 0.05). The mean concentration of 25-hydroxy vitamin D in cord serum was 10.83 ± 6.68 ng/ml in the exposed and 11.05 ± 4.99 ng/ml in the non-exposed group(p > 0.05). The exposed mothers had significantly higher parathyroid hormone level (p = 0.013), lower serum calcium (p = 0.024) and higher serum alkaline phosphatase (p = 0.024). There was a significant correlation between maternal and umbilical cord serum 25-hydroxyvitamin D within both exposed and non-exposed groups (p < 0.001). CONCLUSION: Maternal exposure to cigarette smoking during pregnancy negatively influences serum calcium level and increase parathyroid hormone and alkaline phosphatase in mothers.