phosphate buffer saline

  • 文章类型: Journal Article
    背景:人类免疫缺陷病毒(HIV)快速诊断测试(RDTs)被广泛使用。然而,缓冲库存通常导致使用未经批准的液体,导致错误。我们的目的是评估替代缓冲液的诊断准确性。
    方法:配对测定使用商业缓冲液和本地生产的0.01M磷酸盐缓冲盐水(PBS)对连续同意需要HIV检测的个体进行HIV-1/2快速检测。血清样本通过当地金标准算法(MurexHIVAg/Ab,带有/不带有GeeniusHIV的六边形HIV1/2)。测试精度,还进行了κ和精确的McNemar测试。
    结果:在167名参与者中,137进行了验证性测试。与金标准相比,使用PBS进行的DetermineHIV-1/2测试的灵敏度为100%(95%置信区间[CI]90.5至100),特异性为98%(95%CI92.9至99.8)。与黄金标准相比,κ值为0.94,与使用商业缓冲液的DeterminationHIV-1/2测试相比为0.92。McNemar的测试没有显示不同敏感性的证据。由于操作限制,该研究包括根据样本量计算确定的49例阳性病例中的37例,导致获得的功率为80%,而不是预期的90%。
    结论:这些结果表明,当发生缓冲液缺货时,0.01MPBS是确定HIV-1/2的替代解决方案。
    Human immunodeficiency virus (HIV) rapid diagnostic tests (RDTs) are widely used. However, buffer stockouts commonly lead to utilising non-approved liquids, resulting in errors. Our aim was to evaluate the diagnostic accuracy of an alternative buffer.
    Paired Determine HIV-1/2 rapid tests with commercial buffer and locally produced 0.01M phosphate-buffered saline (PBS) were performed on consecutive consenting individuals requiring HIV testing. Serum samples were sent for confirmation through the local gold-standard algorithm (Murex HIV Ag/Ab, Hexagon HIV with/without Geenius HIV 1/2). Test accuracy, κ and exact McNemar\'s test were also carried out.
    Of 167 participants, 137 had confirmatory testing. The sensitivity of the Determine HIV-1/2 test using PBS compared with the gold standard was 100% (95% confidence interval [CI] 90.5 to 100) with a specificity of 98% (95% CI 92.9 to 99.8). The κ value was 0.94 compared with the gold standard and 0.92 compared with the Determine HIV-1/2 test using the commercial buffer. McNemar\'s test showed no evidence of differing sensitivities. Due to operational constraints, the study included 37 of the 49 positive cases as determined by the sample size calculation, resulting in an attained power of 80% instead of the intended 90%.
    These results suggest that 0.01M PBS is an alternative solution for Determine HIV-1/2 when buffer stockouts occur.
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  • 文章类型: Journal Article
    天然多糖与合成聚合物的共混由于其显著的可生物降解和生物相容性特征而在药物递送模型中引起了极大的关注。这项研究的重点是在不同的组成中轻松制备一系列具有淀粉/聚(烯丙基胺盐酸盐)(ST/PAH)的复合膜,以提出一种新型的药物递送系统(DDS)。开发并表征了ST/PAH共混膜。FT-IR评估证实了混合膜中ST和PAH对应物之间的分子间H键的参与。水接触角(WCA)在71°至100°的范围内,表明所有膜都是疏水性的。以时间依赖性方式在37±0.5°C评价TPH-1(90%ST和10%PAH)的体外控制药物释放(CDR)。在磷酸盐缓冲盐水(PBS)和模拟胃液(SGF)中记录CDR。在SGF(pH1.2)的情况下,在110分钟内,TPH-1的药物释放百分比(DR)约为91%,而在PBS(pH7.4)溶液中80分钟内最大DR为95%。我们的结果表明,制造的生物相容性共混膜可以是用于口服药物给药的持续释放DDS的有希望的候选物。组织工程,伤口敷料,和其他生物医学应用。
    The blending of natural polysaccharides with synthetic polymers has attracted much attention in drug delivery models owing to their remarkable biodegradable and biocompatible characteristics. This study focuses on the facile preparation of a sequence of composite films having Starch/Poly(allylamine hydrochloride) (ST/PAH) in different compositions to propose a novel drug delivery system (DDS). ST/PAH blend films were developed and characterized. FT-IR evaluation confirmed the involvement of intermolecular H-bonding between the ST and PAH counterparts in blended films. The water contact angle (WCA) ranged from 71° to 100° indicating that all the films were hydrophobic. TPH-1 (90 % ST and 10 % PAH) was evaluated for in vitro controlled drug release (CDR) at 37 ± 0.5 °C in a time-dependent fashion. CDR was recorded in phosphate buffer saline (PBS) and simulated gastric fluid (SGF). In the case of SGF (pH 1.2), the percentile drug release (DR) for TPH-1 was approximately 91 % in 110 min, while the maximum DR was 95 % in 80 min in PBS (pH 7.4) solution. Our results demonstrate that the fabricated biocompatible blend films can be a promising candidate for a sustained-release DDS for oral drug administration, tissue engineering, wound dressings, and other biomedical applications.
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  • 文章类型: Journal Article
    Interpreting forensic DNA signal is arduous since the total intensity is a cacophony of signal from noise, artifact, and allele from an unknown number of contributors (NOC). An alternate to traditional bulk-processing pipelines is a single-cell one, where the sample is collected, and each cell is sequestered resulting in n single-source, single-cell EPGs (scEPG) that must be interpreted using applicable strategies. As with all forensic DNA interpretation strategies, high quality electropherograms are required; thus, to enhance the credibility of single-cell forensics, it is necessary to produce an efficient direct-to-PCR treatment that is compatible with prevailing downstream laboratory processes. We incorporated the semi-automated micro-fluidic DEPArray™ technology into the single-cell laboratory and optimized its implementation by testing the effects of four laboratory treatments on single-cell profiles. We focused on testing effects of phosphate buffer saline (PBS) since it is an important reagent that mitigates cell rupture but is also a PCR inhibitor. Specifically, we explored the effect of decreasing PBS concentrations on five electropherogram-quality metrics from 241 leukocytes: profile drop-out, allele drop-out, allele peak heights, peak height ratios, and scEPG sloping. In an effort to improve reagent use, we also assessed two concentrations of proteinase K. The results indicate that decreasing PBS concentrations to 0.5X or 0.25X improves scEPG quality, while modest modifications to proteinase K concentrations did not significantly impact it. We, therefore, conclude that a lower than recommended proteinase K concentration coupled with a lower than recommended PBS concentration results in enhanced scEPGs within the semi-automated single-cell pipeline.
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  • 文章类型: Journal Article
    OBJECTIVE: HPV detection has been proposed as part of the co-testing which improves the sensitivity of cervical screening. However, the commercially liquid-based medium adds cost in low-resource areas. This study aimed to evaluate the performance of ice-cold phosphate buffer saline (PBS) for HPV detection.
    METHODS: HPV DNA from SiHa cells (with 1-2 copies of HPV16 per cell) preserved in ice-cold PBS or PreserveCyt solution at different time points (24, 36, 48, 72, 120 and 168 h) was tested in triplicate using Cobas 4800. The threshold cycle (Ct) values of both solutions were compared. An estimated false negative rate of PBS was also assessed by using the difference in Ct values between both solutions (∆Ct) and Ct values of HPV16-positive PreserveCyt clinical samples (Ctsample) at corresponding time points. Samples with a (Ctsample+∆Ct) value > 40.5 (the cutoff of HPV16 DNA by Cobas 4800) were considered as false negativity.
    RESULTS: The Ct values of HPV16 DNA of SiHa cells collected in PBS were higher than PreserveCyt ranging from 0.43 to 2.36 cycles depending on incubation times. There was no significant difference at 24, 72, 120, and 168 h.  However, the Ct values were statistically significantly higher for PBS than PreserveCyt at 36 h (31.00 vs 29.26), and 48 h (31.06 vs 28.70). A retrospective analysis in 47 clinical PreserveCyt collected samples that were positive for HPV16 DNA found that 1 case (2%) would become negative if collected in ice-cold PBS.
    CONCLUSIONS: The PBS might be an alternative collecting medium for HPV detection in the low-resource areas. Further evaluations are warranted.
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  • 文章类型: Journal Article
    Electron microscopy is a powerful tool to study biological samples at higher magnification. The higher magnifications achieved by the electron microscopes are helpful to the researchers to study surface morphology as well as cellular morphology of the samples. The blood sample surface morphology can be visualized at higher magnification by scanning electron microscope (SEM). For the examination of the blood cells at the cellular level, transmission electron microscopes (TEM) are used. In this article, we have described the step-by-step standard protocol for the preparation of blood samples for electron microscopy. The prepared blood samples can be visualized under SEM and TEM. The obtained electron micrographs of blood cells can be used for differential diagnosis of various diseases at the cellular level.
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  • 文章类型: Journal Article
    We aimed to investigate the effect of intrauterine administration of autologous hCG-activated PBMCs in RIF women with low Th-17/Treg cell ratio. 248 women with a history of implantation failure volunteered to receive PBMC-therapy. After immunologic consultation and doing flow cytometry analysis, 100 women with at least three IVF/ET failure who had low Th-17/Treg ratio in comparison with healthy control were enrolled in this study. These 100 patients were randomly divided into two groups as PBMC receiving (n = 50) and controls (n = 50). Then PBMCs were obtained from patients and treated with hCG for 48 h. Afterward, PBMCs were administered into the uterine cavity of the patient in the study group, two days before ET. The concentration of inflammatory cytokines was examined in the supernatant of cultured PBMCs after 2, 24, and 48 h of incubation using the ELISA method. The frequency of Th-17, Treg, and the Th-17/Treg ratio was significantly lower in RIF women than the healthy controls (P < 0.0001). The secretion of inflammatory cytokines was significantly higher after 48 h compared to 2 and 24 h (P < 0.0001). The pregnancy and live birth rate were significantly increased in women undergoing the PBMC-therapy compared to control (PBS-injecting) group (P = 0.032 and P = 0.047, respectively). The miscarriage rate was considerably lower in PBMC-therapy group (P = 0.029). Our findings suggest that intrauterine administration of autologous in vitro hCG-activated PBMCs improves pregnancy outcomes in patients with at least three IVF/ET failures.
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  • 文章类型: Journal Article
    OBJECTIVE: Neuroinflammation can arise from metabolic disturbances accompanying type 2 diabetes mellitus (T2DM) with an implication of indoleamine 2,3-dioxygenase 1 (IDO1). The antioxidant and anti-inflammatory potentials of melatonin (Mel) can amend diabetic complications. Here, we examined the effect of exogenous melatonin on neuroinflammation in high fat diet (HFD)-induced T2DM rats.
    METHODS: Twenty-one adult male Sprague-dawley rats were divided in to three groups: control group: fed commercial standard rat chow, T2DM group: fed with HFD for 16 weeks, and T2DM-Mel group: received HFD for 8 weeks, followed by weekly melatonin treatment (i.p injection 10 mg/kg in saline) for 8 weeks with continuous supply of HFD. After which, animals were submitted to euthanasia for brain and blood samples collection.
    RESULTS: In T2DM-Mel group the diabetic profile was ameliorated, and the state of low-grade systemic inflammation was alleviated through lowering serum pro-inflammatory cytokines (TNF-α and IL-6) and leptin while increasing adiponectin. Melatonin improved brain oxidative stress by increasing total antioxidant capacity and reduced glutathione (GSH), whereas malondialdehyde was declined. Melatonin reduced acetylcholinesterase (AChE) activity in blood and brain and its hippocampal expression, also hippocampal inducible nitric oxide synthase (iNOS) expression was reduced, moreover IDO1 hippocampal expression was declined, furthermore recovered neuronal morphology following melatonin treatment was also clearly viewed in the hippocampus under the light microscope in T2DM-Mel rats.
    CONCLUSIONS: Melatonin can be considered as a promising solution in preventing neuroinflammation development in T2DM owing to its ability to render the oxidative stress and accompanied low-grade systemic inflammation.
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  • 文章类型: Journal Article
    Pathological α-synuclein (α-syn) overexpression and iron (Fe)-induced oxidative stress (OS) are involved in the death of dopaminergic neurons in Parkinson\'s disease (PD). We have previously characterized the role of triacylglycerol (TAG) formation in the neuronal response to Fe-induced OS. In this work we characterize the role of the α-syn variant A53T during Fe-induced injury and investigate whether lipid metabolism has implications for neuronal fate. To this end, we used the N27 dopaminergic neuronal cell line either untransfected (UT) or stably transfected with pcDNA3 vector (as a transfection control) or pcDNA-A53T-α-syn (A53T α-syn). The overexpression of A53T α-syn triggered an increase in TAG content mainly due to the activation of Acyl-CoA synthetase. Since fatty acid (FA) β-oxidation and phospholipid content did not change in A53T α-syn cells, the unique consequence of the increase in FA-CoA derivatives was their acylation in TAG moieties. Control cells exposed to Fe-induced injury displayed increased OS markers and TAG content. Intriguingly, Fe exposure in A53T α-syn cells promoted a decrease in OS markers accompanied by α-syn aggregation and elevated TAG content. We report here new evidence of a differential role played by A53T α-syn in neuronal lipid metabolism as related to the neuronal response to OS.
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  • 文章类型: Journal Article
    The issue of long-term incompatible interactions associated with the permanent implants can be eliminated by using various biodegradable metal implants. The recent research is focusing on the use of degradable stents to restore most of the hindrances of capillaries, and coronary arteries by supplying instant blood flow with constant mechanical and structural support. However, internal endothelialization and infection due to the corrosion of implanted stents are not easy to diagnose in the long run. In the recent past, magnesium (Mg) has been widely investigated for the cardiovascular stent applications. Here we made an attempt to understand the biodegradation process of Mg alloy stent by studying the degradation of Mg alloy AZ31 (3 wt% Aluminum, 1 wt% Zn) powder at various time-intervals in simulated blood fluid using the Rheological methods. The degradability of the Mg stent in the arteries affects the stress-strain properties of blood plasma and the subsequent flow conditions. Blood and plasma viscosities alter due to the degradation of Mg resulting from the stress-strain experienced in the blood vessels, in which the stent is inserted. Here our objective was to explore the influence of Mg degradation on the blood plasma viscosity by studying the viscoelastic properties. In this work, the effect of dissolution of Mg alloy AZ31 on the rheological properties of Phosphate Buffer Saline (PBS) at various time intervals have been investigated. The viscosity of the PBS-AZ31 solution increased with the dissolution of both slurries and percolated clear solution. The only exception was day-7 of the percolated clear solution, where viscosity was decreased showing a reduction in viscosity at initial stages of dissolution. The frequency sweep showed the tendency of the PBS-AZ31 gelation up to 100 rad/s frequency.
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  • 文章类型: Journal Article
    Three-dimensional (3D) printing is an emerging technology for the fabrication of scaffolds to repair/replace damaged tissue/organs in tissue engineering. This paper presents our study on 3D printed alginate scaffolds treated with phosphate buffered saline (PBS) and polyethyleneimine (PEI) coating and their impacts on the surface morphology and cellular response of the printed scaffolds. In our study, sterile alginate was prepared by means of the freeze-drying method and then, used to prepare the hydrogel for 3D printing into calcium chloride, forming 3D scaffolds. Scaffolds were treated with PBS for a time period of two days and seven days, respectively, and PEI coating; then they were seeded with Schwann cells (RSC96) for the examination of cellular response (proliferation and differentiation). In addition, swelling and stiffness (Young\'s modulus) of the treated scaffolds was evaluated, while their surface morphology was assessed using scanning electron microscopy (SEM). SEM images revealed significant changes in scaffold surface morphology due to degradation caused by the PBS treatment over time. Our cell proliferation assessment over seven days showed that a two-day PBS treatment could be more effective than seven-day PBS treatment for improving cell attachment and elongation. While PEI coating of alginate scaffolds seemed to contribute to cell growth, Schwann cells stayed round on the surface of alginate over the period of cell culture. In conclusion, PBS-treatment may offer the potential to induce surface physical cues due to degradation of alginate, which could improve cell attachment post cell-seeding of 3D-printed alginate scaffolds.
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