RESUMO
Methylene Blue (MB) is a cationic dye causing various health problems such as asthma, heartbeat, eye and skin irritation, nausea, and distress during prolonged exposure. In this regard, the green magnetite nanoparticle was synthesized using the extract of Prosopis farcta. The synthesized Fe3O4nanoparticle was characterized by X-ray powder diffraction (XRD), Field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), Fourier transforms Infrared spectroscopy (FTIR), vibrating sample magnetometer (VSM), and Brunauer-Emmett-Teller (BET). The corresponding parameters, including the primary concentration of MB (5-65 mg/L), the dose of synthesized nanoparticle (0.025-0.925 g/L), solution pH (3-11), and contact time (20-60 min), were considered. Also, central composite design (CCD), as one of the response surface methodologies (RSM), was used for the related modelling and optimization. The particle size of the adsorbent was between 5 and 70 nm, and the nanoparticle has 206.75 m2/g of a specific surface, 6.1 nm of average pore size, and 0.3188 cm3/g of the total pore volume. The optimal conditions for MB removal by the nanoparticle were found to follow an initial MB concentration of 20 mg/L, 0.7 g/L of the nanoparticle dose, pH = 9, and a contact time of 50 min. The pseudo-second-order (PSO) and Freundlich models were the best kinetic and isothermal models for MB removal by the synthesized nanoparticle. Molecular modelling was used to optimize the MB molecular configuration and compute HOMO-LUMO energies, quantum-chemical descriptors, and molecular electrostatic potential to evaluate the nature reactivity of the MB molecule.
Assuntos
Nanopartículas , Poluentes Químicos da Água , Azul de Metileno/química , Adsorção , Nanopartículas/química , Microscopia Eletrônica de Varredura , Cinética , Poluentes Químicos da Água/química , Espectroscopia de Infravermelho com Transformada de FourierRESUMO
Resistance to antibiotics is an emerging and growing threat. To address this threat, attempts are being made by researchers to identify the Volatile Organic Compounds (VOCs) of bacteria. It is believed that unique combinations could be found among the VOCs produced by each microorganism. The current study aimed to identify and compare the VOCs of antibiotic-resistant and standard strains of Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter baumannii and Klebsiella pneumoniae. A polymer of divinylbenzene /carboxen /polydimethylsiloxane was applied for absorption of volatile compounds in headspace bacterial samples in form of a solid phase micro-extraction fiber holder. Gas chromatography-mass spectrometry technique was used for identification of volatile compounds. The analysis of the VOCs indicated that some VOCs appeared only in standard strains while others were common only among resistant strains. Exclusive VOCs to a specific strain were also detected. This study demonstrated that resistant strains of bacteria produced VOCs that were different from those of the standard strains. In addition, VOCs released by bacteria after passing the logarithmic growth phase showed no significant differences. The identification of VOCs can be a precise way to differentiate bacterial species, also it can be said that the VOCs produced by different pathogenic microorganisms can be the suitable biomarkers for their detection.
Assuntos
Bactérias/química , Infecções Respiratórias/microbiologia , Compostos Orgânicos Voláteis/análise , Acinetobacter baumannii/química , Acinetobacter baumannii/efeitos dos fármacos , Acinetobacter baumannii/isolamento & purificação , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Bactérias/isolamento & purificação , Farmacorresistência Bacteriana , Escherichia coli/química , Escherichia coli/efeitos dos fármacos , Escherichia coli/isolamento & purificação , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Klebsiella pneumoniae/química , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/isolamento & purificação , Testes de Sensibilidade Microbiana , Pseudomonas aeruginosa/química , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/isolamento & purificação , Infecções Respiratórias/patologia , Microextração em Fase Sólida , Staphylococcus aureus/química , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/isolamento & purificação , Compostos Orgânicos Voláteis/isolamento & purificaçãoRESUMO
The sustainable processes are now in tremendous demand for nanomaterial synthesis as a result of their unique properties and characteristics. The magnetic nanoparticles comprised of Fe3O4 and its conjugate with abundant and renewable biopolymer, chitosan, were synthesized using Prosopis farcta biomass extract, and the resulting materials were used to adsorb Pb (II) from aqueous solution. Thermodynamic parameters revealed that the sorption of lead (II) on Fe3O4 as well as Fe3O4-Chitosan (Fe3O4-CS) has been an endothermic and self-regulating procedure wherein the sorption kinetics was defined by a pseudo-second-order pattern and the sorption isotherms corresponded to the Freundlich pattern. A multivariable quadratic technique for adsorption process optimization was implemented to optimize the lead (II) adsorption on Fe3O4 and Fe3O4-chitosan nanoparticles, the optimal conditions being pH 7.9, contact time of 31.2 min, initial lead concentration of 39.2 mg/L, adsorbent amount of 444.3 mg, at a 49.7 °C temperature. The maximum adsorption efficiencies under optimal conditions were found to be 69.02 and 89.54 % for Fe3O4 and Fe3O4-CS adsorbents, respectively. Notably, Fe3O4 and Fe3O4-CS can be easily recovered using an external magnet, indicating that they are a viable and cost-effective lead removal option.
Assuntos
Quitosana , Nanopartículas de Magnetita , Prosopis , Poluentes Químicos da Água , Purificação da Água , Chumbo/química , Quitosana/química , Nanopartículas de Magnetita/química , Biomassa , Adsorção , Cinética , Poluentes Químicos da Água/química , Concentração de Íons de Hidrogênio , Purificação da Água/métodosRESUMO
Background: Diagnoses of respiratory tract infections usually happen in the late phase of the disease and usually result in reduction of the pathogen load after broad-spectrum antibiotic therapy, but not in eradication of the pathogen. The development of a non-invasive, fast, and accurate method to detect pathogens has always been of interest to researchers and clinicians alike. Previous studies have shown that bacteria produce organic gases. The current study aimed to identify the volatile organic compounds (VOCs) produced by three respiratory tract pathogens, including Staphylococcus aureus, Escherichia coli and Candida albicans.Methods: The VOCs produced were identified by gas chromatography-mass spectrometry (GC-MS), with prior collection of microbial volatile compounds using solid phase microextraction (SPME) fiber. The volatile compounds were collected by obtaining bacterial headspace samples. Results: Results showed that these three organisms have various VOCs, which were analyzed under different conditions. By ignoring common VOCs, some species-specific VOCs could be detected. The most important VOC of E. coli was indole, also some important VOCs produced by S. aureus were 2,3-pentandione, cis-dihydro-α-terpinyl acetate, 1-decyne, 1,3-heptadiene, 2,5-dimethyl pyrazine, ethyl butanoate and cyclohexene,4-ethenyl. Furthermore, most of the identified compounds by C. albicans are alcohols. Conclusions: The detection of VOCs produced by infectious agents maybe the key to make a rapid and precise diagnosis of infection, but more comprehensive studies must be conducted in this regard.
RESUMO
BACKGROUND: Gastric cancer arises, mainly, on an inflammatory background. Helicobacter pylori neutrophil activating (HP-NAP) protein functions as a potent pro-inflammatory mediator. Similarly, IL-4 plays a critical role in the inflammation pathway, the levels of which are altered by C to T transition at position -590 in its promoter region. Here, we have aimed to assess the risk of gastritis and gastric cancer in the co-presence of these two inflammation modulating mediators. METHODS: Gastritis (n=58) and gastric cancer (n=31) patients were evaluated and compared with H. pylori-positive asymptomatic controls (n=46), for serum antibodies against recombinant HP-NAP and IL-4 C-590T single nucleotide polymorphism using immunoblotting and PCR-RFLP, respectively. Multivariable logistic regression, adjusting for age, gender and ethnicity, was used for data analysis. RESULTS: In terms of susceptibility to gastritis, seropositivity to HP-NAP projected a risk impact of 4.62 fold (OR=4.62, 95% CI=1.50-14.22), which when present in IL-4 -590 T carriers augmented the risk up to 9.7 fold (OR=9.70, 95% CI=2.06-45.69). A similar pattern, but of a stronger magnitude, occurred for the risk of gastric cancer, which was estimated at 9.07 fold (OR=9.07, 95% CI=1.99-42.0) for HP-NAP-seropositive subjects and was drastically amplified (OR=33.64, 95% CI=2.06-548.68), when double-positive (HP-NAP seropositive/IL-4 -590 T carrier) subjects were examined against double negatives (HP-NAP seronegative/IL-4 -590 CC). CONCLUSION: Our preliminary data indicate that serum antibodies against HP-NAP represent a state of risk, which is further exacerbated in IL-4 -590 T carriers. These biomarkers, if validated in larger prospective studies, can be used to screen for gastric cancer susceptibility.
Assuntos
Anticorpos Antibacterianos/sangue , Proteínas de Bactérias/imunologia , Gastrite/genética , Predisposição Genética para Doença , Helicobacter pylori/imunologia , Interleucina-4/genética , Polimorfismo de Nucleotídeo Único/genética , Neoplasias Gástricas/genética , Gastrite/sangue , Gastrite/microbiologia , Heterozigoto , Humanos , Fatores de Risco , Neoplasias Gástricas/sangue , Neoplasias Gástricas/microbiologiaRESUMO
BACKGROUND: Recurrent spontaneous abortion (RSA) and in vitro fertilization (IVF) failure with unknown causes are the controversial issues that are probably related to the immune system. OBJECTIVE: To compare circulating NK cells expressing activation and inhibition surface markers between patients with RSA and IVF failure with those of healthy multiparous and successful IVF control women, respectively. METHODS: In this case-control study peripheral blood samples were collected from 43 patients who included 23 women with RSA and 20 with IVF failure, plus 43 healthy control women comprising of 36 normal multiparous women and seven women with successful IVF. The expression of CD69, CD94 and CD161 surface markers on CD56+NK cells were assessed using specific monoclonal antibodies by flowcytometry. RESULTS: The percentage of NK cells increased significantly in patients with RSA and in women with IVF failure in comparison to healthy multiparous and successful IVF control groups (p<0.001). The overall expression of CD69, CD94, CD161 were also increased significantly on NK cells in both patient groups compared to control groups (p<0.001). CONCLUSION: Elevated expression of CD69 and CD161 on NK cells can be considered as immunological risk markers in RSA and IVF failure. However, it is not clear if high expression of CD94 on peripheral blood NK cells is related to abnormal activity of endometrial NK cells.
Assuntos
Aborto Habitual/imunologia , Aborto Habitual/metabolismo , Antígenos CD/metabolismo , Antígenos de Diferenciação de Linfócitos T/metabolismo , Fertilização in vitro , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/metabolismo , Lectinas Tipo C/metabolismo , Subfamília B de Receptores Semelhantes a Lectina de Células NK/metabolismo , Subfamília D de Receptores Semelhantes a Lectina de Células NK/metabolismo , Adulto , Estudos de Casos e Controles , Feminino , Citometria de Fluxo , Humanos , Imunofenotipagem , Linfócitos/imunologia , Linfócitos/metabolismo , Pessoa de Meia-Idade , Gravidez , Adulto JovemRESUMO
BACKGROUND: Multiple etiologic factors are suspected to cause gastric cancer, the most important of which is infection with virulent types of Helicobacter pylori. MATERIALS AND METHODS: We have compared 102 gastric cancer patients with 122 non-ulcer, non-cancer dyspeptic patients. Gastric specimens were evaluated for H. pylori infection by tissue-based detection methods. Patient sera underwent antigen-specific ELISA and western blotting using a Helicoblot 2.1 kit and antibody responses to various H. pylori antigens were assessed. RESULTS: The absolute majority (97-100%) of both groups were H. pylori seropositive. Multivariate regression analysis demonstrated serum antibodies to the low molecular weight 35kDa protein to be protective and reduce the risk of gastric cancer by 60% (OR:0.4; 95%CI:0.1-0.9). Conversely, seroreactivity to the 89kDa (VacA) protein was significantly higher in gastric cancer patients (OR:2.7; 95%CI:1.0-7.1). There was a highly significant association (p<0.001) between seroreactivity to the 116kDa (CagA) and 89kDa (VacA) proteins, and double positive subjects were found at nearly five fold (OR:4.9; 95%CI:1.0-24.4) enhanced risk of gastric cancer as compared to double negative subjects. CONCLUSIONS: Seroreactivity to H. pylori low (35kDa) and high (116kDa/89kDa) molecular weight antigens were respectively revealed as protective and risk indicators for gastric cancer.
Assuntos
Adenocarcinoma/etiologia , Anticorpos Antibacterianos/sangue , Antígenos de Bactérias/imunologia , Dispepsia/etiologia , Infecções por Helicobacter/imunologia , Helicobacter pylori/imunologia , Neoplasias Gástricas/etiologia , Adenocarcinoma/sangue , Adenocarcinoma/epidemiologia , Adulto , Idoso , Western Blotting , Estudos de Casos e Controles , Dispepsia/sangue , Dispepsia/epidemiologia , Ensaio de Imunoadsorção Enzimática , Feminino , Seguimentos , Infecções por Helicobacter/complicações , Infecções por Helicobacter/microbiologia , Helicobacter pylori/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Fatores de Risco , Neoplasias Gástricas/sangue , Neoplasias Gástricas/epidemiologiaRESUMO
Recent studies support the concept that NK cells play an important role in the success or failure of embryo implantation. Recurrent spontaneous abortion (RSA) is the most common complication of pregnancy. Some couples suffer from infertility of unknown cause. In vitro fertilization (IVF) is one of the useful treatment methods used for treatment of this type for infertility with variable outcomes. The aim of this study was to compare the percentage of peripheral blood CD56(+) (CD56(dim) and CD56(bright)) cells and the level of NK cell cytotoxicity in patients with RSA and patients with IVF failure with those of healthy multiparous and successful IVF control women. In this case-control study peripheral blood samples from 43 patients, which included 23 women with RSA and 20 with IVF failure, plus 43 healthy control women comprising 36 normal multiparous women and 7 women with successful IVF, were collected. The percentage of peripheral blood NK cells (CD56(+)) was identified by flow cytometry, then peripheral blood mononuclear cells (PBMC) were isolated by density centrifugation (Ficol-Hypaque) and incubated with NK-sensitive K562 cells. The NK cell cytotoxicity level was determined by lactate dehydrogenase (LDH) release assay. The percentage of CD56(dim) cells and the level of peripheral blood NK cell cytotoxicity in RSA patients and women with IVF failure were significantly higher than in both the healthy multiparous and successful IVF control groups (P<0.001). The findings of the present study suggest that increases in the percentage of CD56(dim) cells and NK cytotoxicity in peripheral blood may be important contributing factors for both RSA and IVF failure.
Assuntos
Aborto Habitual/imunologia , Antígeno CD56 , Fertilização in vitro , Imunidade Celular , Células Matadoras Naturais/imunologia , Aborto Habitual/sangue , Aborto Habitual/patologia , Adulto , Estudos de Casos e Controles , Feminino , Humanos , Células K562 , Células Matadoras Naturais/metabolismo , Células Matadoras Naturais/patologia , Contagem de Linfócitos , GravidezRESUMO
BACKGROUND: Attempts for early detection of gastric cancer have recently focused on host's genetic susceptibility factors and gene-environment interactions. We have, herein, studied the association of MTHFR C677T single nucleotide polymorphism (SNP) and its interaction with Helicobacter pylori infection, smoking, age and gender on the risk of gastric cancer among an Iranian population. METHODS: Gastric cancer patients (n = 450) and cancer-free controls (n = 780) were studied for serum H. pylori-specific IgG antibodies by ELISA and MTHFR C677T polymorphism (SNP) by PCR-RFLP. Demographic and life style data were collected through patient interviews. Unconditional logistic regression model estimated odds ratio (OR) and the corresponding 95% confidence intervals (CI). RESULTS: The interactions of MTHFR genotype with H. pylori infection (P = 0.03), age (P = 0.049) and gender (P = 0.007) were statistically significant. Accordingly, MTHFR C677T carriers who were also positive for H. pylori infection exhibited 80% (OR = 1.8, 95% CI = 1.0-2.9) significant excess risk of non-cardia gastric cancer. Furthermore, subjects over the age of 50 or female subjects carrying MTHFR C677T SNP showed 40 (OR = 1.4, 95% CI = 1.0-2.0) and 100 (OR = 2.0, 95% CI = 1.2-3.2) percent increased risk of gastric cancer, respectively. CONCLUSION: MTHFR C677T SNP seems to increase the risk of gastric cancer and the effect is significantly inflated by interactions with H. pylori infection, age and gender.