scholarly journals Fast colorimetric detection of albumin-to-creatinine ratio using paper-based analytical devices with alkaline picrate and Bromothymol Blue reagents

Author(s):  
Nurrahmah Nurrahmah ◽  
Amalia Kikie Trivia ◽  
Sulistyarti Hermin ◽  
Sabarudin Akhmad
2011 ◽  
Vol 9 (2) ◽  
pp. 90 ◽  
Author(s):  
Rohola Hemmati ◽  
Mojgan Gharipour ◽  
Hasan Shemirani ◽  
Alireza Khosravi ◽  
Elham Khosravi ◽  
...  

Background:Appearance of microalbuminuria, particularly in patients with hypertension, might be associated with a higher prevalence of left ventricular (LV) dysfunction and geometric abnormalities. This study was undertaken to determine whether high urine albumin to creatinine ratio (UACR) as a sensitive marker for microalbuminuria can be associated with LV hypertrophy (LVH) and systolic and diastolic LV dysfunction.Methods:The study population consisted of 125 consecutive patients with essential uncomplicated hypertension. Urine albumin and creatinine concentration was determined by standard methods. LVH was defined as a LV mass index >100 g/m2 of body surface area in women and >130 g/m2 in men. Echocardiographic LV systolic and diastolic parameters were measured.Results:The prevalence of microalbuminuria in patients with essential hypertension was 5.6 %. UACR was significantly no different in patients with LVH than in patients with normal LV geometry (21.26 ± 31.55 versus 17.80 ± 24.52 mg/mmol). No significant correlation was found between UACR measurement and systolic and diastolic function parameters, including early to late diastolic peak velocity (E/A) ratio (R=-0.192, p=0.038), early diastolic peak velocity to early mitral annulus velocity (E/E') ratio (R=-0.025, p=0.794), LV ejection fraction (R=0.008, p=0.929), and LV mass (R=-0.132, p=0.154). According to the receiver operator characteristic (ROC) curve analysis, UACR measurement was not an acceptable indicator of LVH with areas under the ROC curves 0.514 (95 % confidence interval 0.394–0.634). The optimal cut-off value for UACR for predicting LVH was identified at 9.4, yielding a sensitivity of 51.6 % and a specificity of 48.3 %.Conclusion:In patients with uncomplicated essential hypertension, abnormal systolic and diastolic LV function and geometry cannot be effectively predicted by the appearance of microalbuminuria.


2019 ◽  
Author(s):  
Huifang Xu ◽  
Weinan Liang ◽  
Linlin Ning ◽  
Yuanyuan Jiang ◽  
Wenxia Yang ◽  
...  

P450 fatty acid decarboxylases (FADCs) have recently been attracting considerable attention owing to their one-step direct production of industrially important 1-alkenes from biologically abundant feedstock free fatty acids under mild conditions. However, attempts to improve the catalytic activity of FADCs have met with little success. Protein engineering has been limited to selected residues and small mutant libraries due to lack of an effective high-throughput screening (HTS) method. Here, we devise a catalase-deficient <i>Escherichia coli</i> host strain and report an HTS approach based on colorimetric detection of H<sub>2</sub>O<sub>2</sub>-consumption activity of FADCs. Directed evolution enabled by this method has led to effective identification for the first time of improved FADC variants for medium-chain 1-alkene production from both DNA shuffling and random mutagenesis libraries. Advantageously, this screening method can be extended to other enzymes that stoichiometrically utilize H<sub>2</sub>O<sub>2</sub> as co-substrate.


Author(s):  
Carla Eiras

Interleukin-6 (IL-6) is a multifunctional cytokine and high bloodstream levels of which have been associated with severe inflammatory diseases, such as dengue fever, sepsis, various cancers, and visceral leishmaniasis (VL). Rapid tests for the quantification of IL-6 would be of great assistance for the bedside diagnosis and treatment of diseases such as VL. We have developed a lateral flow assay (LFA) for rapid and colorimetric IL-6 detection, consisting of anti-IL-6 antibodies conjugated to gold nanoparticles (AuNPs). The optimal concentration of anti-IL-6 used in the conjugate was determined to be 800.0 μg/mL, based on an aggregation assay using LFA. A linear relationship between IL-6 standard concentration and color intensity was observed after 20 min, with a linear range between 1.25 ng/mL and 9,000 ng/mL. The limit of detection for this method was estimated a t0.38 ng/mL. The concentration of IL-6 in five patients with severe VL was measured using LFA, and the results were consistent with those obtained using the cytometric bead array (CBA) method. A thorough analysis of the LFA membranes’ surface morphology, before and after sample contact, was performed using atomic force microscopy (AFM).The prototype described here is still being tested and improved, but this LFA will undoubtedly be of great help in the clinical quantification of IL-6.


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