86 research outputs found
Supervised oral HIV self-testing is accurate in rural KwaZulu Natal, South Africa
Objectives: To achieve UNAIDS 90-90-90 targets, alternatives to conventional HIV testing models are necessary in South Africa to increase population awareness of their HIV status. One of the alternatives is oral mucosal transudates-based HIV self-testing (OralST). This study describes implementation of counsellor-introduced supervised OralST in a high HIV prevalent rural area. Methods: Cross-sectional study conducted in two government-run primary healthcare clinics and three Médecins Sans Frontières-run fixed-testing sites in uMlalazi municipality, KwaZulu-Natal. Lay counsellors sampled and recruited eligible participants, sought informed consent and demonstrated the use of the OraQuick(™) OralST. The participants used the OraQuick(™) in front of the counsellor and underwent a blood-based Determine(™) and a Unigold(™) rapid diagnostic test as gold standard for comparison. Primary outcomes were user error rates, inter-rater agreement, sensitivity, specificity and predictive values. Results: A total of 2198 participants used the OraQuick(™) , of which 1005 were recruited at the primary healthcare clinics. Of the total, 1457 (66.3%) were women. Only two participants had to repeat their OraQuick(™) . Inter-rater agreement was 99.8% (Kappa 0.9925). Sensitivity for the OralST was 98.7% (95% CI 96.8-99.6), and specificity was 100% (95% CI 99.8-100). Conclusion: This study demonstrates high inter-rater agreement, and high accuracy of supervised OralST. OralST has the potential to increase uptake of HIV testing and could be offered at clinics and community testing sites in rural South Africa. Further research is necessary on the potential of unsupervised OralST to increase HIV status awareness and linkage to care
Characterization and in vitro sensitivity of cholinesterases of gilthead seabream (Sparus aurata) to organophospate pesticides.
The characterization of cholinesterase activity in brain and muscle of gilthead seabream was carried out using four specific substrates and three selective inhibitors. In addition, Km and Vmax were calculated from the Michaelis-Menten equation for ASCh and BSCh substrates. Finally, the in vitro sensitivity of brain and muscle cholinesterases to three organophosphates was also investigated by estimating inhibition kinetics. The results indicate that, AChE is the enzyme present in the brain, whereas in muscle, a typical AChE form is present along with an atypical form of BChE. Very low ChE activity was found in plasma with all substrates used. The Inhibitory potency of the studied OPs on brain and muscle AChEs, based on bimolecular inhibition constants (ki) was: omethoate < dichlorvos < azinphosmethyl-oxon. Furthermore, muscle BChE was found to be several orders of magnitude (from 2 to 4) more sensitive than brain and muscle AChE inhibition by dichlorvos and omethoat
The Effects of Exposing Solea senegalensis to Microbeads with and Without Pesticides
Microplastics (MP) are contaminants able to cause adverse effects on organisms. MPs are capable to interact with other environmental contaminants, including pesticides, altering their toxicity. The objective of the study was to research the sublethal effects (enzymatic activity) of pesticides alone and in combination with MPs. Cholinesterase enzymes are used as biomarkers to determine and evaluate the effects produced in organisms after exposure to pollutants. This study showed the acetylcholinesterase (AChE) enzymatic activity in the tissue of Solea senegalensis exposed to two environmental pollutants, the insecticide chlorpyrifos (CPF) and antibacterial triclosan (TCS) with and without microplastics (MPs). Solea senegalensis was chosen because it is a species in high demand because of its high economic value in southern Europe, as well as the use of this species in ecotoxicology and its increasing use as sentinel species, which justify using it to assess biological effects of pollutants. Toxicity tests were performed in organisms exposed to concentrations of between 5 and 80 mu g/L CPF and 0.1 and 0.4 mg/L TCS for 96 h. In addition, each test incorporated MPs that were added at different concentrations in order to evaluate their role as a possible enhancer of the effects caused by the previous pollutants. In the case of CPF, the head and muscle tissue cholinesterase activity was inhibited from a concentration of 5 mu g/L both without and with MPs, and the AChE enzymatic activity for the treatment with MPs was approximately half the activity for the treatment without MPs in the tissues studied. Besides, TCS inhibited the cholinesterase activity at a concentration of 0.3 mg/L in the muscle of S. senegalensis. In contrast, no significant differences were observed in the TCS + MP treatment compared to the controls. These results showed the importance of studies in assessing the anticholinesterase effects of pesticides combined with microplastics due to the abundance of these contaminants in the marine environment and the role of cholinesterase activity (biomarker) in the neurotransmission of key physiological processes
Microplastic pollution in wastewater treatment plants in the city of Cádiz: Abundance, removal efficiency and presence in receiving water body
Wastewater treatment plants (WWTPs) have been appointed as one of the main sources of microplastics (MP) into marine ecosystems. The aim of this research work has been to study the influent and effluent of two WWTPs, both located in Cádiz, with different wastewater source (industrial and urban), as well as the receiving water bodies where the facilities discharge their sewage. MP were collected, extracted from wastewater matrixes and analysed according to the abundance, shape, size, and type of polymer, along with the removal rates of MPs in the plants. Subsequently, the data obtained on both WWTPs were compared, the main difference among the WWTPs was the amount of microplastics found in the wastewater, as well as the presence of polymers with resins from industrial activities. The results from this study established that the most representative form was fibers; about the size, 100–355 μm fraction was the most abundant, followed by 355–1000 μm and finally the size among 1000–5000 μm. Regarding to the type of polymers, 17 were identified using attenuated total refraction Fourier-transformed infrared spectroscopy (ATR-FTIR). Further, PVC, PE, EAA and HDPE were the largest found polymers. The presence of MPs in the influent varied from 645.03 ± 182.24 MPs/L to 1567.49 ± 413.18 MPs/L in the urban and industrial WWTP respectively; in the effluent, it varied from 16.40 ± 7.85 MPs/L to 131.35 ± 95.36 MPs/L. The removal rate overcome the 90% in all the samples. Receiving water bodies presented heterogeneous abundance of microplastics 6.64 ± 2.71 MPs/L and 0.83 ± 0.26 MPs/L in the zones close to IWWTP and UWWTP discharge point. The results obtained shows that despite the elimination efficiency in the WWTPs studied, these facilities act as a significant source of MPs into aquatic ecosystem due to large flow of water discharged.9 página
Pharmaceutical Products and Pesticides Toxicity Associated with Microplastics (Polyvinyl Chloride) in Artemia salina
Pharmaceutical products, as well as insecticides and antimicrobials, have been extensively
studied, but knowledge of their effects—especially those caused by their mixtures with microplastics—
on aquatic organisms remains limited. However, it should be borne in mind that the state of
knowledge on acute and chronic effects in aquatic organisms for pharmaceuticals and pesticides is
not similar. In response, this investigation analyzed the presence of microplastics (polyvinyl chloride)
and their impacts on the toxicity of chlorpyrifos (an insecticide) and triclosan (an antibacterial) when
they coincide in the environment, alongside the two most consumed drugs of their type (hypolipemic
and anticonvulsant, respectively), namely simvastatin and carbamazepine, in Artemia salina. LC50 and
cholinesterase enzyme activity were calculated to determine the possible neurotoxicity associated
with emergent contaminants in the treatments. The LC50 values obtained were 0.006 mg/dm3
for chlorpyrifos, 0.012 mg/dm3 for chlorpyrifos associated with microplastics, 4.979 mg/dm3 for
triclosan, 4.957 mg/dm3 for triclosan associated with microplastics, 9.35 mg/dm3 for simvastatin,
10.29 mg/dm3 for simvastatin associated with microplastics, 43.25 mg/dm3 for carbamazepine and
46.50 mg/dm3 for carbamazepine associated with microplastics in acute exposure. These results
indicate that the presence of microplastics in the medium reduces toxicity, considering the LC50 values.
However, exposure to chlorpyrifos and carbamazepine, both alone and associated with microplastics,
showed a decline in cholinesterase activity, confirming their neurotoxic effect. Nevertheless, no
significant differences were observed with the biomarker cholinesterase between the toxicant and the
toxicant with microplastics.This research was funded by the Ministerio de Ciencia, Investigacion y Universidades (REF.: RTI2018-096771-B-100)
Colaboración del alumnado en la nube: una experiencia con Google Docs
En este trabajo presentamos el análisis de una actividad colaborativa basada en Google Docs. La experiencia de innovación docente se ha diseñado en el marco de la asignatura Toxicología Ambiental y Ecotoxicología, materia troncal de 4º curso de la Licenciatura en Ciencias Ambientales. El trabajo se enmarca en el proyecto "Estrategias digitales para fomentar el aprendizaje y el trabajo colaborativo" (Código PI2_12_043), dentro de la Convocatoria de Proyectos y Mejora Docente del curso 2011/12 de la Universidad de Cádiz. El objetivo general del proyecto es el desarrollo e implementación de actividades basadas en las TICs yen el aprendizaje colaborativo, y más concretamente en el concepto de colaboración en la nube.Unidad de Innovación Docente. Vicerrectorado de Docencia y Formación. Universidad de Cádiz
A method to remove cellulose from rich organic samples to analyse microplastics
Knowing the amount of microplastics that currently reach wastewater is extremely important today. Furthermore, carrying out a good quantification and detection of the type of plastic provides valuable information. However, the wastewater is loaded, in addition to a high concentration of organic matter, with a high concentration of cellulose at the treatment plant influent, which seriously hinders detection, quantification and classification of microplastics. The abundance of cellulose materials makes them possible to become false positives for microplastics. Numerous studies on the analysis of microplastics in different matrices show how to remove organic matter from samples, but there are very few studies on the removal of cellulose, which is also found in the samples and hinders their analysis. This study offers a method that combines, for the analysis of microplastics, the already known advanced oxidation treatments for the elimination of organic matter with the novel cellulose removal treatment of the samples with the aim of reducing the amount of cellulose in the influent samples of conventional wastewater treatment plants. To remove the cellulose, 40 mL of a solution of urea 8%, sodium hydroxide 8% and thiourea 6.5% (by weight) were added for every 100 mg of dry sample. The beakers were placed in the freezer at minus 20 °C for 40 min and were then placed in agitation until they reached room temperature. After that, the samples were passed through a 53 μm mesh sieve. They were washed 15 times with 30 mL of ultra-pure water. The method is called UTS because of the acronym of its reagents (Urea/Thiourea/Sodium Hydroxide). By using the UTS method it is possible to reduce almost completely the cellulose residues from the influent sewage, and sludge samples by 97.6% in a second UTS treatment and 98.2% in a third UTS treatment. In all cases analyzed, the microplastics were identified as high density polyethylene (HDPE) with correlation indices higher than 0.97, which shows that the treatment is harmless for this type of plastic material. The UTS method in combination with the WPO is an efficient and effective method for the analysis of microplastics in different matrices where cellulose and organic matter may cause possible interferences.8 página
Treating 4,000 diabetic patients in Cambodia, a high-prevalence but resource-limited setting: a 5-year study
BACKGROUND: Despite the worldwide increasing burden of diabetes, there has been no corresponding scale-up of treatment in developing countries and limited evidence of program effectiveness. In 2002, in collaboration with the Ministry of Health of Cambodia, Médecins Sans Frontières initiated an outpatient program of subsidized diabetic care in two hospital-based chronic disease clinics in rural settings. We aimed to describe the outcomes of newly and previously diagnosed diabetic patients enrolled from 2002 to 2008. METHODS: We calculated the mean and proportion of patients who met the recommended treatment targets, and the drop from baseline values for random blood glucose (RBG), hemoglobin A1c (HbA1c), blood pressure (BP), and body mass index (BMI) at regular intervals. Analysis was restricted to patients not lost to follow-up. We used the t test to compare baseline and subsequent paired values. RESULTS: Of 4404 patients enrolled, 2,872 (65%) were still in care at the time of the study, 24 (0.5%) had died, and 1,508 (34%) were lost to follow-up. Median age was 53 years, 2,905 (66%) were female and 4,350 (99%) had type 2 diabetes. Median (interquartile range (IQR)) follow-up was 20 months (5 to 39.5 months). A total of 24% (51/210) of patients had a HbA1c concentration of <7% and 35% (709/1,995) had a RBG <145 mg/dl within 1 year. There was a significant drop of 109 mg/dl (95% confidence interval (CI) 103.1 to 114.3) in mean RBG (P < 0.001) and a drop of 2.7% (95% CI 2.3 to 3.0) in mean HbA1c (P < 0.001) between baseline and month 6. In all, 45% (327/723) and 62% (373/605) of patients with systolic or diastolic hypertension at baseline, respectively, reached = 130/80 mm Hg within 1 year. There was a drop of 13.5 mm Hg (95% CI 12.1 to 14.9) in mean systolic blood pressure (SBP) (P < 0.001), and a drop of 11.7 mm Hg (95% CI 10.8 to 12.6) in mean diastolic blood pressure (DBP) (P < 0.001) between baseline and month 6. Only 22% (90/401) patients with obesity at baseline lowered their BMI <27.5 kg/m2 after 1 year. Factors associated with loss to follow-up were male sex, age >60 years, living outside the province, normal BMI on admission, high RBG on last visit, and coming late for the last consultation. CONCLUSION: Significant and clinically important improvements in glycemia and BP were observed, but a relatively low proportion of diabetic patients reached treatment targets. These results and the high loss to follow-up rate highlight the challenges of delivering diabetic care in rural, resource-limited settings
Graphene Oxide Nanosheets Interact and Interfere with SARS‐CoV‐2 Surface Proteins and Cell Receptors to Inhibit Infectivity
From Wiley via Jisc Publications RouterHistory: received 2021-03-13, pub-electronic 2021-05-14Article version: VoRPublication status: PublishedFunder: University of PaduaFunder: UKRI EPSRC; Grant(s): EP/P00119X/1Funder: Turkish Academy of Sciences (TUBA)Funder: Scientific and Technology Council of Turkey; Grant(s): 18AG020Funder: Türkiye Bilimler Akademisi; Id: http://dx.doi.org/10.13039/501100004412; Grant(s): GEBIP 2018Funder: Türkiye Bilimsel ve Teknolojik Araştirma Kurumu; Id: http://dx.doi.org/10.13039/501100004410; Grant(s): 18AG020Funder: Engineering and Physical Sciences Research Council; Id: http://dx.doi.org/10.13039/501100000266; Grant(s): EP/P00119X/1Abstract: Nanotechnology can offer a number of options against coronavirus disease 2019 (COVID‐19) acting both extracellularly and intracellularly to the host cells. Here, the aim is to explore graphene oxide (GO), the most studied 2D nanomaterial in biomedical applications, as a nanoscale platform for interaction with SARS‐CoV‐2. Molecular docking analyses of GO sheets on interaction with three different structures: SARS‐CoV‐2 viral spike (open state – 6VYB or closed state – 6VXX), ACE2 (1R42), and the ACE2‐bound spike complex (6M0J) are performed. GO shows high affinity for the surface of all three structures (6M0J, 6VYB and 6VXX). When binding affinities and involved bonding types are compared, GO interacts more strongly with the spike or ACE2, compared to 6M0J. Infection experiments using infectious viral particles from four different clades as classified by Global Initiative on Sharing all Influenza Data (GISAID), are performed for validation purposes. Thin, biological‐grade GO nanoscale (few hundred nanometers in lateral dimension) sheets are able to significantly reduce copies for three different viral clades. This data has demonstrated that GO sheets have the capacity to interact with SARS‐CoV‐2 surface components and disrupt infectivity even in the presence of any mutations on the viral spike. GO nanosheets are proposed to be further explored as a nanoscale platform for development of antiviral strategies against COVID‐19
Toxicity of parathion on embryo and yolk-sac larvae of gilthead seabream (Sparus aurata l.): Effects on survival, cholinesterase, and carboxylesterase activity
This study was conducted to examine the acute toxicity of the organophosphorus pesticide (OP) parathion on embryos and yolk-sac larvae of gilthead seabream (Sparus aurata), and to investigate the effects of this compound on cholinesterase and carboxylesterase activity of seabream larvae in the phase of endogenous feeding. The 72-h LC50 for yolk-sac larvae (0.523 mg L-1) was about two-fold lower than the 48-h LC50 for embryos (1.005 mg L-1). Parathion significantly inhibited the activity of ChE and CaE activity in yolk sac larvae but there were not significant differences in the sensitivity of both esterases to parathion as inferred by their 72-h IC50 values. Larvae exposed to parathion for 72 h showed a 70% inhibition of the whole body acetylcholinesterase at approximately the LC50. © 2009 Wiley Periodicals, Inc.Peer Reviewe
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