44 research outputs found
A factorial design for optimization of the analytical variables on the development of a genoassay for the transgenic soybean detection
At the laboratory, analytical method optimizations are performed to achieve the
maximum sensitivity and selectivity. Routinely, this procedure is carried out by
optimizing one-factor-at-a-time approach until there is no further improvement,
where each experimental parameter is optimized separately and independently of the
other factors.N/
DNA-based biosensor for the electrocatalytic determination of antioxidant capacity in beverages
Reactive oxygen species (ROS) are produced as a consequence of normal aerobic metabolism and are
able to induce DNA oxidative damage. At the cellular level, the evaluation of the protective effect of
antioxidants can be achieved by examining the integrity of the DNA nucleobases using electrochemical
techniques. Herein, the use of an adenine-rich oligonucleotide (dA21) adsorbed on carbon paste electrodes
for the assessment of the antioxidant capacity is proposed. The method was based on the partial damage
of a DNA layer adsorbed on the electrode surface by OH• radicals generated by Fenton reaction and
the subsequent electrochemical oxidation of the intact adenine bases to generate an oxidation product
that was able to catalyze the oxidation of NADH. The presence of antioxidant compounds scavenged
hydroxyl radicals leaving more adenines unoxidized, and thus, increasing the electrocatalytic current of
NADHmeasured by differential pulse voltammetry (DPV). Using ascorbic acid (AA) as a model antioxidant
species, the detection of as low as 50nMof AA in aqueous solution was possible. The protection efficiency
was evaluated for several antioxidant compounds. The biosensor was applied to the determination of the
total antioxidant capacity (TAC) in beverages
Electrocatalytic evaluation of DNA damage by superoxide radical for antioxidant capacity assessment
The integrity of DNA purine bases was herein used to evaluate the antioxidant capacity. Unlike other
DNA-based antioxidant sensors reported so far, the damaging agent chosen was the O
2 radical enzymatically
generated by the xanthine/xanthine oxidase system. An adenine-rich oligonucleotide was adsorbed
on carbon paste electrodes and subjected to radical damage in the presence/absence of several antioxidant
compounds. As a result, partial damage on DNA was observed. A minor product of the radical oxidation
was identified by cyclic voltammetry as a diimine adenine derivative also formed during the
electrochemical oxidation of adenine/guanine bases. The protective efficiency of several antioxidant compounds
was evaluated after electrochemical oxidation of the remaining unoxidized adenine bases, by
measuring the electrocatalytic current of NADH mediated by the adsorbed catalyst species generated.
A comparison between O
2 and OH radicals as a source of DNA lesions and the scavenging efficiency
of various antioxidant compounds against both of them is discussed. Finally, the antioxidant capacity
of beverages was evaluated and compared with the results obtained with an optical method
Revealing prevalent cancers by interrogating glycoproteins with sustainable immunoelectrochemical tools
Trabajo presentado en el 4th European Biosensor Symposium, celebrado en Aquisgrán (Alemania), del 27 al 30 de agosto de 2023Introduction. The worldwide incidence and death toll of colorectal and pancreatic cancers (CRC and PDAC) have increased considerably since 1990. For this reason, both early detection and regular follow-up are considered key factors in improving patient prognosis. In this sense, the determination of the total content of specific proteins and their aberrantly glycosylated fraction in oncologic processes could help to achieve the proposed goals.
Results and Discussion. In this work, two simple but highly competitive electrochemical immunoplatforms for the determination of total and glycosylated post-translational modified haptoglobin (Hp) [1], and CA19-9 [2] (candidate biomarkers associated
with colorectal and pancreatic cancer, respectively) are presented.
As seen in Figure 1, these biotools are uplifted in the use of magnetic immunocaptors and another antibody or a lectin as detector elements lastly labeled with HRP, which enables subsequent amperometric detection.
The presented bioplatforms exhibit attractive characteristics in terms of simplicity, affordability, and point-of-care application compared to the conventional available methodologies, highlighting low detection limits (0.07 and 0.46 ng mL¿1 for total and
glycosylated Hp, respectively, and 1.5 U mL¿1 for CA19-9), and short assay times (< 2 h).
The workability of these quantitative bioplatforms for the analysis of secretomes from cultured CRC cells with the distinct potential to metastasize (Hp) or serum samples from healthy and PDAC-diagnosed subjects (CA19-9) was assessed to definitely confirm full exploitation of all the above exposed enticing attributes.
Conclusions. Our findings clearly revealed the unquestionable ability of these modern electrochemical immunoplatforms to discriminate between healthy and cancer-diagnosed subjects, as well as to assess disease progression, positioning these simple but effective methodologies as advanced electroanalytical tools with proven real biomedical applications, and the hope of aiding in the accurate diagnosis of prevalent and high mortality cancers
Global dataset of soil organic carbon in tidal marshes.
Tidal marshes store large amounts of organic carbon in their soils. Field data quantifying soil organic carbon (SOC) stocks provide an important resource for researchers, natural resource managers, and policy-makers working towards the protection, restoration, and valuation of these ecosystems. We collated a global dataset of tidal marsh soil organic carbon (MarSOC) from 99 studies that includes location, soil depth, site name, dry bulk density, SOC, and/or soil organic matter (SOM). The MarSOC dataset includes 17,454 data points from 2,329 unique locations, and 29 countries. We generated a general transfer function for the conversion of SOM to SOC. Using this data we estimated a median (± median absolute deviation) value of 79.2 ± 38.1 Mg SOC ha-1 in the top 30 cm and 231 ± 134 Mg SOC ha-1 in the top 1 m of tidal marsh soils globally. This data can serve as a basis for future work, and may contribute to incorporation of tidal marsh ecosystems into climate change mitigation and adaptation strategies and policies
Epigenetic polypharmacology: from combination therapy to multitargeted drugs
The modern drug discovery process has largely focused its attention in the so-called magic bullets, single chemical entities that exhibit high selectivity and potency for a particular target. This approach was based on the assumption that the deregulation of a protein was causally linked to a disease state, and the pharmacological intervention through inhibition of the deregulated target was able to restore normal cell function. However, the use of cocktails or multicomponent drugs to address several targets simultaneously is also popular to treat multifactorial diseases such as cancer and neurological disorders. We review the state of the art with such combinations that have an epigenetic target as one of their mechanisms of action. Epigenetic drug discovery is a rapidly advancing field, and drugs targeting epigenetic enzymes are in the clinic for the treatment of hematological cancers. Approved and experimental epigenetic drugs are undergoing clinical trials in combination with other therapeutic agents via fused or linked pharmacophores in order to benefit from synergistic effects of polypharmacology. In addition, ligands are being discovered which, as single chemical entities, are able to modulate multiple epigenetic targets simultaneously (multitarget epigenetic drugs). These multiple ligands should in principle have a lower risk of drug-drug interactions and drug resistance compared to cocktails or multicomponent drugs. This new generation may rival the so-called magic bullets in the treatment of diseases that arise as a consequence of the deregulation of multiple signaling pathways provided the challenge of optimization of the activities shown by the pharmacophores with the different targets is addressed
Risk profiles and one-year outcomes of patients with newly diagnosed atrial fibrillation in India: Insights from the GARFIELD-AF Registry.
BACKGROUND: The Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) is an ongoing prospective noninterventional registry, which is providing important information on the baseline characteristics, treatment patterns, and 1-year outcomes in patients with newly diagnosed non-valvular atrial fibrillation (NVAF). This report describes data from Indian patients recruited in this registry. METHODS AND RESULTS: A total of 52,014 patients with newly diagnosed AF were enrolled globally; of these, 1388 patients were recruited from 26 sites within India (2012-2016). In India, the mean age was 65.8 years at diagnosis of NVAF. Hypertension was the most prevalent risk factor for AF, present in 68.5% of patients from India and in 76.3% of patients globally (P < 0.001). Diabetes and coronary artery disease (CAD) were prevalent in 36.2% and 28.1% of patients as compared with global prevalence of 22.2% and 21.6%, respectively (P < 0.001 for both). Antiplatelet therapy was the most common antithrombotic treatment in India. With increasing stroke risk, however, patients were more likely to receive oral anticoagulant therapy [mainly vitamin K antagonist (VKA)], but average international normalized ratio (INR) was lower among Indian patients [median INR value 1.6 (interquartile range {IQR}: 1.3-2.3) versus 2.3 (IQR 1.8-2.8) (P < 0.001)]. Compared with other countries, patients from India had markedly higher rates of all-cause mortality [7.68 per 100 person-years (95% confidence interval 6.32-9.35) vs 4.34 (4.16-4.53), P < 0.0001], while rates of stroke/systemic embolism and major bleeding were lower after 1 year of follow-up. CONCLUSION: Compared to previously published registries from India, the GARFIELD-AF registry describes clinical profiles and outcomes in Indian patients with AF of a different etiology. The registry data show that compared to the rest of the world, Indian AF patients are younger in age and have more diabetes and CAD. Patients with a higher stroke risk are more likely to receive anticoagulation therapy with VKA but are underdosed compared with the global average in the GARFIELD-AF. CLINICAL TRIAL REGISTRATION-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01090362
Global dataset of soil organic carbon in tidal marshes
Tidal marshes store large amounts of organic carbon in their soils. Field data quantifying soil organic carbon (SOC) stocks provide an important resource for researchers, natural resource managers, and policy-makers working towards the protection, restoration, and valuation of these ecosystems. We collated a global dataset of tidal marsh soil organic carbon (MarSOC) from 99 studies that includes location, soil depth, site name, dry bulk density, SOC, and/or soil organic matter (SOM). The MarSOC dataset includes 17,454 data points from 2,329 unique locations, and 29 countries. We generated a general transfer function for the conversion of SOM to SOC. Using this data we estimated a median (± median absolute deviation) value of 79.2 ± 38.1 Mg SOC ha−1 in the top 30 cm and 231 ± 134 Mg SOC ha−1 in the top 1 m of tidal marsh soils globally. This data can serve as a basis for future work, and may contribute to incorporation of tidal marsh ecosystems into climate change mitigation and adaptation strategies and policies