RESUMO
Pap smears play a role in detecting extrauterine serous tumours in asymptomatic women. Certain cytopathologic and histopathologic findings combined with relevant clinical and radiologic findings indicate the possibility of primary peritoneal serous tumours. Cellblock immunohistochemistry is a valuable confirmatory diagnostic tool.
Assuntos
Cistadenocarcinoma Seroso , Imuno-Histoquímica , Teste de Papanicolaou , Neoplasias Peritoneais , Esfregaço Vaginal , Humanos , Feminino , Teste de Papanicolaou/métodos , Imuno-Histoquímica/métodos , Neoplasias Peritoneais/patologia , Neoplasias Peritoneais/diagnóstico , Cistadenocarcinoma Seroso/patologia , Cistadenocarcinoma Seroso/diagnóstico , Pessoa de Meia-IdadeRESUMO
The Internet of Things (IoT) is a growing network of interconnected devices used in transportation, finance, public services, healthcare, smart cities, surveillance, and agriculture. IoT devices are increasingly integrated into mobile assets like trains, cars, and airplanes. Among the IoT components, wearable sensors are expected to reach three billion by 2050, becoming more common in smart environments like buildings, campuses, and healthcare facilities. A notable IoT application is the smart campus for educational purposes. Timely notifications are essential in critical scenarios. IoT devices gather and relay important information in real time to individuals with special needs via mobile applications and connected devices, aiding health-monitoring and decision-making. Ensuring IoT connectivity with end users requires long-range communication, low power consumption, and cost-effectiveness. The LPWAN is a promising technology for meeting these needs, offering a low cost, long range, and minimal power use. Despite their potential, mobile IoT and LPWANs in healthcare, especially for emergency response systems, have not received adequate research attention. Our study evaluated an LPWAN-based emergency response system for visually impaired individuals on the Hazara University campus in Mansehra, Pakistan. Experiments showed that the LPWAN technology is reliable, with 98% reliability, and suitable for implementing emergency response systems in smart campus environments.
Assuntos
Internet das Coisas , Humanos , Aplicativos Móveis , Tecnologia sem FioRESUMO
The incorporation of l-ascorbic acid into food products is challenging for food industries due to its chemical instability. This study was conducted to develop a nanoemulsion-based effective colloidal system for the incorporation of l-ascorbic acid (LAA) in functional food products. l-ascorbic acid was encapsulated in nanoemulsions prepared through high-pressure homogenization. The physicochemical characteristics of mixed-surfactant-based LAA nanoemulsions were investigated during storage at different temperatures. The droplet size of LAA nanoemulsions after one month of storage varied in the range of 121.36-150.15 and 121.36-138.25 nm at 25 and 4 °C, respectively. These nanoemulsions remained stable against processing conditions such as heat treatments (10-70 °C), different salt concentrations (40-320 mM), change in pH (3-9), and four freeze-thaw cycles. The temperature and storage intervals have a significant (p < 0.05) effect on the retention of LAA in nanoemulsion-based delivery systems. The findings of this research work have important implications in the designing and preparation of an effective encapsulation system for the inclusion of l-ascorbic acid into functional food products.
Assuntos
Ácido Ascórbico , Tensoativos , Emulsões , Excipientes , TemperaturaRESUMO
In recent years, fire detection technologies have helped safeguard lives and property from hazards. Early fire warning methods, such as smoke or gas sensors, are ineffectual. Many fires have caused deaths and property damage. IoT is a fast-growing technology. It contains equipment, buildings, electrical systems, vehicles, and everyday things with computing and sensing capabilities. These objects can be managed and monitored remotely as they are connected to the Internet. In the Internet of Things concept, low-power devices like sensors and controllers are linked together using the concept of Low Power Wide Area Network (LPWAN). Long Range Wide Area Network (LoRaWAN) is an LPWAN product used on the Internet of Things (IoT). It is well suited for networks of things connected to the Internet, where terminals send a minute amount of sensor data over large distances, providing the end terminals with battery lifetimes of years. In this article, we design and implement a LoRaWAN-based system for smart building fire detection and prevention, not reliant upon Wireless Fidelity (Wi-Fi) connection. A LoRa node with a combination of sensors can detect smoke, gas, Liquefied Petroleum Gas (LPG), propane, methane, hydrogen, alcohol, temperature, and humidity. We developed the system in a real-world environment utilizing Wi-Fi Lora 32 boards. The performance is evaluated considering the response time and overall network delay. The tests are carried out in different lengths (0-600 m) and heights above the ground (0-2 m) in an open environment and indoor (1st Floor-3rd floor) environment. We observed that the proposed system outperformed in sensing and data transfer from sensing nodes to the controller boards.
Assuntos
Fontes de Energia Elétrica , Fumaça , Monitorização Fisiológica/métodos , Umidade , TemperaturaRESUMO
Remediation by algae is a very effective strategy for avoiding the use of costly, environmentally harmful chemicals in wastewater treatment. Recently, industries based on biomass, especially the bioenergy sector, are getting increasing attention due to their environmental acceptability. However, their practical application is still limited due to the growing cost of raw materials such as algal biomass, harvesting and processing limitations. Potential use of algal biomass includes nutrients recovery, heavy metals removal, COD, BOD, coliforms, and other disease-causing pathogens reduction and production of bioenergy and valuable products. However, the production of algal biomass using the variable composition of different wastewater streams as a source of growing medium and the application of treated water for subsequent use in agriculture for irrigation has remained a challenging task. The present review highlights and discusses the potential role of algae in removing beneficial nutrients from different wastewater streams with complex chemical compositions as a biorefinery concept and subsequent use of produced algal biomass for bioenergy and bioactive compounds. Moreover, challenges in producing algal biomass using various wastewater streams and ways to alleviate the stress caused by the toxic and high concentrations of nutrients in the wastewater stream have been discussed in detail. The technology will be economically feasible and publicly accepted by reducing the cost of algal biomass production and reducing the loaded or attached concentration of micropollutants and pathogenic microorganisms. Algal strain improvement, consortium development, biofilm formation, building an advanced cultivation reactor system, biorefinery concept development, and life-cycle assessment are all possible options for attaining a sustainable solution for sustainable biofuel production. Furthermore, producing valuable compounds, including pharmaceutical, nutraceutical and pigment contents generated from algal biomass during biofuel production, could also help reduce the cost of wastewater management by microalgae.
Assuntos
Biocombustíveis , Microalgas , Águas Residuárias , Biodegradação Ambiental , BiomassaRESUMO
The present study investigated the stability and efficacy of a biosurfactant produced by Klebsiella sp. KOD36 under extreme conditions and its potential for enhancing the solubilization and degradation of phenanthrene in various environmental matrices. Klebsiella sp. KOD36 produced a mono-rhamnolipids biosurfactant with a low critical micelle concentration (CMC) value. The biosurfactant was stable under extreme conditions (60 °C, pH 10 and 10% salinity) and could lower surface tension by 30% and maintained an emulsification index of > 40%. The emulsion index was also higher (17-43%) in the presence of petroleum hydrocarbons compared to synthetic surfactant Triton X-100. Investigation on phenanthrene degradation in three different environmental matrices (aqueous, soil-slurry and soil) confirmed that the biosurfactant enhanced the solubilization and biodegradation of phenanthrene in all matrices. The high functional stability and performance of the biosurfactant under extreme conditions on phenanthrene degradation show the great potential of the biosurfactant for remediation applications under harsh environmental conditions.
Assuntos
Biodegradação Ambiental , Klebsiella/fisiologia , Fenantrenos/metabolismo , Tensoativos/metabolismo , Meios de Cultura , Emulsões , Glicolipídeos , Hidrocarbonetos/metabolismo , Klebsiella/metabolismo , Micelas , Petróleo/metabolismo , Solo , Poluentes do Solo/metabolismoRESUMO
Cloud computing is a fully fledged, matured and flexible computing paradigm that provides services to scientific and business applications in a subscription-based environment. Scientific applications such as Montage and CyberShake are organized scientific workflows with data and compute-intensive tasks and also have some special characteristics. These characteristics include the tasks of scientific workflows that are executed in terms of integration, disintegration, pipeline, and parallelism, and thus require special attention to task management and data-oriented resource scheduling and management. The tasks executed during pipeline are considered as bottleneck executions, the failure of which result in the wholly futile execution, which requires a fault-tolerant-aware execution. The tasks executed during parallelism require similar instances of cloud resources, and thus, cluster-based execution may upgrade the system performance in terms of make-span and execution cost. Therefore, this research work presents a cluster-based, fault-tolerant and data-intensive (CFD) scheduling for scientific applications in cloud environments. The CFD strategy addresses the data intensiveness of tasks of scientific workflows with cluster-based, fault-tolerant mechanisms. The Montage scientific workflow is considered as a simulation and the results of the CFD strategy were compared with three well-known heuristic scheduling policies: (a) MCT, (b) Max-min, and (c) Min-min. The simulation results showed that the CFD strategy reduced the make-span by 14.28%, 20.37%, and 11.77%, respectively, as compared with the existing three policies. Similarly, the CFD reduces the execution cost by 1.27%, 5.3%, and 2.21%, respectively, as compared with the existing three policies. In case of the CFD strategy, the SLA is not violated with regard to time and cost constraints, whereas it is violated by the existing policies numerous times.
Assuntos
Algoritmos , Computação em Nuvem , Simulação por Computador , Heurística , Fluxo de TrabalhoRESUMO
Nitrate pollution in water environments is a ubiquitous problem. Solid-phase denitrification (SPD) is a technology that has attracted in recent years increasing attention due to its significant advantage suitability over the aqueous-based denitrification for in situ water remediation. This paper provides a view of new aspects of the application of SPD for water remediation. The processes and mechanisms for nitrogen transformation in SPD, for example, direct denitrification, dissimilatory nitrate reduction to ammonium, and anammox are presented. The main processes of the transformation of the carbon substrate in SPD are also discussed. The major limitations of SPD, including low carbon availability, NO2 - and N2O accumulation, dissolved organic carbon release, and NH4 + production, are summarized and the factors associated with such limitations are also discussed. In addition, some novel measures to mitigate these limitations, such as applying a biodegradable polymer substrate and heterotrophic-autotrophic denitrification (HAD) process, are described. Finally, simultaneous removal of nitrate and some typical concurrent contaminants for expanded application of SPD are discussed. This review attempts to advance our understanding of engineered denitrification processes for wastewater treatment or water remediation.
Assuntos
Reatores Biológicos , Desnitrificação , Água/química , Compostos de Amônio , Processos Autotróficos , Biodegradação Ambiental , Carbono , Concentração de Íons de Hidrogênio , Nitratos , Nitrogênio , Óxido Nitroso , Praguicidas , Águas Residuárias , Poluição da Água , Purificação da ÁguaRESUMO
Negatively charged residue αAsp-350 of the highly conserved VISIT-DG sequence is required for Pi binding and maintenance of the phosphate-binding subdomain in the catalytic sites of Escherichia coli F1Fo ATP synthase. αAsp-350 is situated in close proximity, 2.88â¯Å and 3.5â¯Å, to the conserved known phosphate-binding residues αR376 and ßR182. αD350 is also in close proximity, 1.3â¯Å, to another functionally important residue αG351. Mutation of αAsp-350 to Ala, Gln, or Arg resulted in substantial loss of oxidative phosphorylation and reduction in ATPase activity by 6- to 16-fold. The loss of the acidic side chain in the form of αD350A, αD350Q, and αD350R caused loss of Pi binding. While removal of Arg in the form of αR376D resulted in the loss of Pi binding, the addition of Arg in the form of αG351R did not affect Pi binding. Our data demonstrates that αD350R helps in the proper orientation of αR376 and ßR182 for Pi binding. Fluoroaluminate, fluoroscandium, and sodium azide caused almost complete inhibition of wild type enzyme and caused variable inhibition of αD350 mutant enzymes. NBD-Cl (4-chloro-7-nitrobenzo-2-oxa-1, 3-diazole) caused complete inhibition of wild type enzyme while some residual activity was left in mutant enzymes. Inhibition characteristics supported the conclusion that NBD-Cl reacts in ßE (empty) catalytic sites. Phosphate protected against NBD-Cl inhibition of wild type and αG351R mutant enzymes but not inhibition of αD350A, αD350Q, αD350R, or αR376D mutant enzymes. These results demonstrate that αAsp-350 is an essential residue required for phosphate binding, through its interaction with αR376 and ßR182, for normal function of phosphate binding subdomain and for transition state stabilization in ATP synthase catalytic sites.
Assuntos
Ácido Aspártico/química , Proteínas de Escherichia coli/metabolismo , Escherichia coli/enzimologia , ATPases Translocadoras de Prótons/metabolismo , Difosfato de Adenosina/metabolismo , Sequência de Bases , Biocatálise , Domínio Catalítico , Proteínas de Escherichia coli/química , Proteínas de Escherichia coli/genética , Mutação , Fosfatos/metabolismo , Ligação Proteica , Domínios Proteicos , ATPases Translocadoras de Prótons/química , ATPases Translocadoras de Prótons/genéticaRESUMO
Acute renal failure complicates renal ischemia-reperfusion (I/R) owing to reactive oxygen species production. Atorvastatin (ATO) has anti-inflammatory and antioxidant properties. The current study investigated whether ATO alleviated damage induced by renal I/R injury in nondiabetic versus diabetic rat models. Thirty-six rats were equally divided into 6 groups: group A1 (nondiabetic sham), group A2 (nondiabetic I/R), group A3 (nondiabetic ATO + I/R), group B1 (diabetic sham), group B2 (diabetic I/R), and group B3 (diabetic ATO + I/R). All groups experienced 45 min of bilateral renal ischemia followed by 24 h of reperfusion. Groups A3 and B3 were treated with single intraperitoneal doses of ATO (10 mg/kg) 30 min before ischemia. Histological analysis of kidney tissues, kidney function tests, and analyses of caspase-3 and CD44 expression and oxidative stress markers were performed to assess tubular injury. Histological analysis revealed marked tubular damage in groups A2 and B2 but improvement in groups A3 and B3. Improvements were also found in groups A3 and B3 for caspase-3 and CD44 expression, kidney function tests, and oxidative stress markers. Our results suggest ATO may ameliorate renal I/R injury differently between nondiabetic and diabetic rats.
Assuntos
Atorvastatina/administração & dosagem , Diabetes Mellitus Experimental/tratamento farmacológico , Inibidores de Hidroximetilglutaril-CoA Redutases/administração & dosagem , Precondicionamento Isquêmico/métodos , Córtex Renal/efeitos dos fármacos , Traumatismo por Reperfusão/tratamento farmacológico , Injúria Renal Aguda/tratamento farmacológico , Injúria Renal Aguda/metabolismo , Injúria Renal Aguda/patologia , Animais , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/patologia , Córtex Renal/metabolismo , Córtex Renal/patologia , Masculino , Ratos , Ratos Sprague-Dawley , Traumatismo por Reperfusão/metabolismo , Traumatismo por Reperfusão/patologiaRESUMO
Antibiotics and heavy metals have long-term potential toxicity to the environment, and their residuals in agricultural soils are receiving more and more attention. To evaluate the ecotoxicological effects of enrofloxacin and cadmium on soil enzymatic activities and microbial community structure, soil samples were exposed to individual and combined contaminants over 28 days. The results indicated that the toxic effects of enrofloxacin alone on soil enzymatic activities were relatively small and showed no concentration dependence. In contrast, significant inhibition of soil enzymatic activities was observed upon cadmium contamination by itself. Overall, the combination of two contaminants also has toxic effect on enzymatic activities; an antagonism between enrofloxacin and cadmium was observed. On 14 and 21 days, individual enrofloxacin and cadmium reduced average well color development (AWCD), Shannon, McIntosh, Simpson indices, and substrate utilization, except for Shannon, McIntosh, Simpson indices of the cadmium 0.4 mmol/kg treatment were higher than the control on 21 days. In general, combined treatments led to higher value of these microbial diversity indicators than those found under separate contamination, although there were some exceptions. With the increase in enrofloxacin concentration, the utilization of any carbon source by the microorganisms gradually decreased. In addition, the AWCD value and substrate utilization decreased as time increased. In the separate and combined contaminant treatments, the order of substrate utilization by soil microorganisms was aliphatics > amino acids > saccharides > metabolites. Thus, enrofloxacin and cadmium had a variable but generally negative influence on soil enzymatic activities and microbial community structure.
Assuntos
Cádmio/toxicidade , Enrofloxacina/toxicidade , Enzimas/metabolismo , Microbiologia do Solo , Poluentes do Solo/toxicidade , Cádmio/análise , Carbono/metabolismo , China , Ecotoxicologia , Enrofloxacina/análise , Microbiota , Solo/química , Poluentes do Solo/análiseRESUMO
Livestock and poultry manure containing high levels of copper and zinc have led to contamination of farmland and products which could have an impact on human health. Biochar is an inexpensive and efficient heavy metal absorbent. In the present study, we have used biochar to mitigate the effects of heavy metals on the growth of wheat seedlings. The study showed that the effects of heavy metals on wheat seedlings growth were mitigated by increasing exposure to biochar. Compared to the control group, the germination potential, germination rate, germination index and vigor index of wheat seedlings with supplemented biochar increased significantly. Moreover, the specific activity of catalase, peroxidase, superoxide dismutase decreased and chlorophyll contents increased, which promote wheat growth and suggests that the addition of biochar could reduce the effects of heavy metals on wheat seedlings.
Assuntos
Carvão Vegetal/química , Cobre/toxicidade , Recuperação e Remediação Ambiental/métodos , Poluentes do Solo/toxicidade , Triticum/fisiologia , Zinco/toxicidade , Catalase , Clorofila , Grão Comestível/química , Germinação , Esterco , Metais Pesados/análise , Oryza , Plântula/efeitos dos fármacos , Solo , Poluentes do Solo/análise , Triticum/efeitos dos fármacos , Triticum/enzimologiaRESUMO
In recent years, pharmaceuticals and personal care products (PPCPs) that remain in the environment have become increasingly important. Carbamazepine (CBZ) is a widely used antiepileptic drug that has a potential impact on the environment due to its Physico-chemical properties, which are rarely eliminated in conventional water treatment. Daphnia magna Straus (DMS) is a fundamental link of aquatic ecosystem chain. The influence of CBZ toxicity on DMS can effectively reflect the effects of CBZ toxicity on the aquatic environment. In this study, DMS was used as a subject to assess the chronic effects of CBZ exposure. It was found that after 21 days of CBZ exposure, the breeding frequency, the total number of eggs laid, body length, and intrinsic growth rate of DMS decreased with increasing CBZ concentrations. Maximum reductions of 69% in fecundity and 60% in fertility were observed at 0.5 mg/L CBZ, while a maximum reduction of 60% in body length was observed at 0.001 mg/L CBZ concentration. The integrated biomarker response version 2 (IBRv2) analysis suggests that with the increase in CBZ concentration, the overall negative effect of CBZ on DMS was enhanced.
Assuntos
Anticonvulsivantes/toxicidade , Carbamazepina/toxicidade , Daphnia/efeitos dos fármacos , Daphnia/crescimento & desenvolvimento , Poluentes Químicos da Água/toxicidade , Animais , Relação Dose-Resposta a Droga , Ecossistema , Fertilidade/efeitos dos fármacos , Reprodução/efeitos dos fármacosRESUMO
Application of manure resulted in high concentration of antibiotics in soil. Compared to the wide literature on the adverse effects of antibiotics on animals and human beings, the effects on plants are less investigated. In this study, we investigated the growth inhibiting effects of four antibiotics (OTC, DOX, OFL, and ENR) on cucumber, rape and Chinese cabbage using hydroponic methods. Seeds of three vegetable varieties were separately exposed to six concentrations of OTC and DOX (0, 10, 30, 50, 70 and 90 mg/L) and OFL and ENR (0, 20, 40, 80, 160 and 320 mg/L). The growth inhibiting effects of the four antibiotics on three vegetables were different. This study has shown that these antibiotics can induce potential growth inhibiting effects in the natural environment.
Assuntos
Antibacterianos/toxicidade , Brassica/fisiologia , Cucumis sativus/fisiologia , Poluentes do Solo/toxicidade , Animais , Esterco , Solo , Verduras/crescimento & desenvolvimentoRESUMO
The widespread use of pharmaceutical and personal care products (PPCPs) has attracted much attention and the impact of PPCPs on indigenous microbial communities has become increasingly important in recent days. Five common PPCPs, including doxycycline (DOX), ciprofloxacin (CIP), triclocarban (TCC), carbamazepine (CBZ), and sulfadimidine (SMZ), were selected and their effects on soil microbial respiration were studied at concentrations of 0, 0.2, 1, 5, 25 and 50 mg/kg. The results of this study indicate that the effect of five common PPCPs on soil microbial respiration was dose- and time- dependent. At low concentrations (0.2 and 1 mg/kg), CBZ and SMZ exhibited an activation effect on microbial soil respiration at 1 day (58.02%, 26.39% and 1.54%, 1.76% at 0.2 and 1 mg/kg respectively), while DOX showed inhibition for all tested concentrations at 1 day of incubation. At high concentrations (25 and 50 mg/kg) CIP and SMZ showed an inhibitory effect (- 69.13%, - 80.86% for 25 and 50 mg/kg, respectively), while TCC and CBZ exhibited stimulatory effect (38.07%, 9.64% and 4.06%, 12.18% at 25 and 50 mg/kg, respectively) at 1 day of incubation. Our findings indicate that the effect of tested PPCPs on soil microbial respiration had an inhibitory or stimulatory effect based on the dose and extent of time.
Assuntos
Microbiologia do Solo , Poluentes do Solo/toxicidade , Carbamazepina/análise , Carbamazepina/toxicidade , Carbanilidas/toxicidade , Cosméticos/análise , Preparações Farmacêuticas , Solo , Poluentes do Solo/análiseRESUMO
Atorvastatin (ATO) was commonly used to lower blood cholesterol, but it caused harmful effects to organs, including the liver. Thymoquinone (TQ), a prominent constituent of Nigella sativa, has antioxidant, antiinflammatory, antiapoptotic, antimicrobial, and anticancer activity. The current study investigated the mechanism of ATO-induced hepatotoxicity, whether posttreatment TQ could reverse ATO-induced hepatic injury, and the mechanism of action of TQ as a hepatoprotective agent. Forty adult male Sprague Dawley rats were divided into four equal groups: control, TQ-treated, ATO-treated, and combined ATO/TQ-treated. Rats were treated for 8 weeks and 10 days and euthanized by cervical dislocation 3 days after the last treatment. Blood samples and livers were tested for liver enzymes, oxidative stress, and apoptosis markers and used for histopathological and ultrastructural examination. The ATO-treated group showed an increase in liver enzymes, decreases in reduced glutathione and catalase, and increases in the malondialdehyde lipid peroxidation marker, protein carbonylation, and caspase 3 activity. Posttreatment TQ in the ATO/TQ-treated group seemed to reverse these changes. Histopathological and ultrastructural examination supported these data. Results from the current study suggested that posttreatment TQ may reverse oxidative stress injury in rat liver produced by ATO, suggesting a potential clinical application of using TQ to prevent ATO-induced hepatic injury.
Assuntos
Atorvastatina/efeitos adversos , Benzoquinonas/farmacologia , Fígado/patologia , Estresse Oxidativo/efeitos dos fármacos , Animais , Fígado/efeitos dos fármacos , Fígado/ultraestrutura , Masculino , Avaliação de Resultados em Cuidados de Saúde , Ratos Sprague-DawleyRESUMO
AIMS: Polymyxin E was used for treating gram-negative bacterial infections but not recently for fear of its nephrotoxicity. Silybin has potential to counteract nephrotoxicity; however, few studies have investigated its protective effect on the kidney in an animal model. The purpose of the present study was to assess whether silybin could decrease elevated urine and serum renal biochemical markers induced by polymyxin E in rat kidney. METHODS: Forty rats were divided randomly into four groups of 10 rats: control (I), vehicle (II), treatment (III, using polymyxin E), and protection (IV, using silybin and polymyxin E). Urine was collected daily for 7 days to test for N-acetyl-beta-D-glucosaminidase (NAG). Serum was collected after euthanizing the rats on day 7 to test kidney functions. RESULTS Group III had significant increases in NAG (all P < 0.001) compared with the other groups, but no differences were found between the other groups. Significant differences in kidney functions were found between Group III and Groups I and II, and between Group IV and Groups I and II (all P < 0.001). No differences were found between Groups III and IV. CONCLUSIONS: Group III results suggested an affection of the renal glomeruli and tubules, and Group IV results suggested a possible protective effect of silybin against polymyxin E-induced nephrotoxicity. Additional studies are recommended that use different doses of silybin for Groups III and IV to test for statistical differences for kidney functions and that test the protective effect of silybin against nephrotoxicity induced by polymyxin E in humans.
Assuntos
Colistina/toxicidade , Rim/efeitos dos fármacos , Substâncias Protetoras/farmacologia , Silimarina/farmacologia , Acetilglucosaminidase/metabolismo , Animais , Rim/metabolismo , Masculino , Ratos , Ratos Sprague-Dawley , SilibinaRESUMO
AIMS: Although once a common antibiotic, polymyxin E fell out of favor after reports of its nephrotoxicity. However, recent concerns with gram-negative bacteria, which are resistant to multiple antibiotics, have resulted in increased interest in polymyxin E. Silybin is a known antihepatotoxic drug and may have potential for protecting the kidney from polymyxin E. Therefore, the aim of the current study was to evaluate whether silybin affected the damages produced by polymyxin E on the rat kidney. METHODS: Four groups of rats with 10 rats per group were included in the study: control (no treatment, group I), vehicle (control vehicle treatment, group II), polymyxin E treatment (group III), and polymyxin E and silybin treatment (group IV). Groups II-IV received intravenous treatment twice a day for 7 days. All rats were euthanized after 7 days. Histological, ultrastructural, and morphometric analyses were performed on the rats' kidney tissues. RESULTS: Analysis of tissues from group III showed differences from groups I and II, such as glomerular and tubular affection and changes in morphometric measures. Results for group IV were more similar to those of groups I and II than those of group III. CONCLUSIONS: Our results suggested that administering silybin with polymyxin E alleviated polymyxin E-induced nephrotoxicity in the rat kidney. Future biochemical studies should investigate whether silybin could ameliorate the nephrotoxicity caused by polymyxin E in rats and whether concomitant administration of silybin could be an effective clinical pharmacological strategy to protect against polymyxin E-induced insult in human kidneys.
Assuntos
Colistina/toxicidade , Nefropatias/tratamento farmacológico , Rim/efeitos dos fármacos , Substâncias Protetoras/uso terapêutico , Silimarina/uso terapêutico , Animais , Rim/patologia , Nefropatias/patologia , Masculino , Substâncias Protetoras/administração & dosagem , Ratos , Ratos Sprague-Dawley , Silibina , Silimarina/administração & dosagemRESUMO
F1-ATPase, the catalytic complex of the ATP synthase, is a molecular motor that can consume ATP to drive rotation of the γ-subunit inside the ring of three αß-subunit heterodimers in 120° power strokes. To elucidate the mechanism of ATPase-powered rotation, we determined the angular velocity as a function of rotational position from single-molecule data collected at 200,000 frames per second with unprecedented signal-to-noise. Power stroke rotation is more complex than previously understood. This paper reports the unexpected discovery that a series of angular accelerations and decelerations occur during the power stroke. The decreases in angular velocity that occurred with the lower-affinity substrate ITP, which could not be explained by an increase in substrate-binding dwells, provides direct evidence that rotation depends on substrate binding affinity. The presence of elevated ADP concentrations not only increased dwells at 35° from the catalytic dwell consistent with competitive product inhibition but also decreased the angular velocity from 85° to 120°, indicating that ADP can remain bound to the catalytic site where product release occurs for the duration of the power stroke. The angular velocity profile also supports a model in which rotation is powered by Van der Waals repulsive forces during the final 85° of rotation, consistent with a transition from F1 structures 2HLD1 and 1H8E (Protein Data Bank).
Assuntos
Aceleração , Escherichia coli/enzimologia , Modelos Moleculares , Proteínas Motores Moleculares/metabolismo , Conformação Proteica , ATPases Translocadoras de Prótons/metabolismo , Rotação , Hidrólise , Imagem Molecular/métodos , ATPases Translocadoras de Prótons/isolamento & purificaçãoRESUMO
We studied the functional role of highly conserved VISIT-DG sequence residues αIle-346 and αIle-348 in the catalytic sites of Escherichia coli F1Fo ATP synthase. αIle-346 is in close proximity, 2.98 and 3.63 Å, to the two known phosphate binding residues αR376 and ßR182; αIle-348 is situated within 3.66 Å from ßR182. Single or double mutants of both αI346 and αI348 resulted in a variable loss of oxidative phosphorylation and ATPase activity. Azide, fluoroaluminate, and fluoroscandium caused insignificant to significant inhibition of mutants. Whereas the wild-type enzyme was completely inhibited by NBD-Cl (7-chloro-4-nitrobenzo-2-oxa-1, 3-diazole), a variable extent of inhibition was observed for αI346 and αI348 mutants. MgPi protection against NBD-Cl induced inhibition of wild-type, αI346, and αI348 demonstrated that, although strongly conserved, αI346 and αI348 have no direct role in phosphate binding. Insertion of Arginine in the form of αI346R/ßR182A, αI346R/αR376A, or αI348R/ßR182A was able to compensate for the absence of known phosphate-binding Arginine residues ßR182 and αR376. Results also suggest that αIle-346 and αIle-348 seem to have functional importance in upholding the phosphate-binding subdomain and transition state stabilization in the catalytic sites of E. coli ATP synthase.