Thermal treatment under oxidative conditions increases the antioxidant and antiglycation activity of Chilean Tórtola beans (Phaseolus vulgaris).

The influence of oxygen on the thermal treatment (TT) of secondary metabolite-enriched extracts (SMEEs) from Tórtola beans and procyanidin C1 (PC1) on the inhibition of advanced glycation end products (AGEs) generation in proteins was investigated. SMEE was incubated at 4 °C (control) or thermally treated at 60 °C for 2 h, at either 0 % O2 (I) or 20 % O2 (II). Treatments I and II increased the content of procyanidin dimers B2. Treatment II was more effective than the control or treatment I in preventing homocysteine oxidation and AGEs generation. TT of PC1 at 0 % or 20 % O2 generated procyanidin dimers and tetramers. PC1 TT at 20 % O2 exhibited higher oxidation potentials and lower IC50 values of fluorescent AGEs than those of controls or TT at 0 % O2. These findings indicate that SMEE from Tórtola beans after treatment II changes the degree of polymerization and oxidation procyanidins, thereby increasing their antiglycation activity.

Evaluation of the Chetomin effect on histopathological features in a murine acute spinal cord injury model.

Background: Several research studies have been focused on improving the treatment and prognosis of acute spinal cord injury, as part of this initiative we investigated the use of Chetomin to reduce the inflammatory response in this pathology. Methods: An experimental, prospective, cross-sectional study was performed using 42 Wistar rats where we analyzed the effect of Chetomin compared to methylprednisolone administered 1 and 8 h after the spinal cord injury in a murine model. Results: Chetomin administration 8h post-injury decreased IL-6 and VEGF expression; and, and its administration 1h post-injury decreased NF-kB expression. Conclusions: Chetomin has anti-inflammatory effects in acute spinal cord injury, whether these effects are observable with other proinflammatory markers should be investigated.

Assessing the potential fasting and postprandial mechanisms involved in the acute hypoglycemic and anti-hyperglycemic effects of four selected plants from Iran used in traditional Persian medicine.

ETHNOPHARMACOLOGICAL RELEVANCE: In traditional Persian medicine (TPM), people often use herbal infusions as a dosage form to treat diseases related to hyperglycemia, known as 'dam-kardeh'. Traditionally, herbal preparations of Eryngium bungei Boiss. (E. b), Tragopogon buphthalmoides (DC.) Boiss. (T. b), Salvia hydrangea DC. ex Benth. (S. h), and Juniperus polycarpos K. Koch. (J. p) are used to manage diabetes in Iran. However, there is no evidence of their effectiveness in controlling glucose levels and their mechanisms remain unclear. AIM OF THE STUDY: This study aimed to investigate whether traditional doses of plant infusions can have hypoglycemic and/or anti-hyperglycemic effects during fasting and/or postprandial states and establish the basis for future research on their potential mechanisms of action. MATERIALS AND METHODS: The effects of traditional doses of herbal extracts on blood glucose levels in STZ-NA-induced hyperglycemic rats were investigated in 2-h acute tests during fasting and postprandial states (with a glucose load). In addition, the potential inhibitory effect in vitro of enzymes involved in relevant pathways, such as gluconeogenesis (fructose-1,6-bisphosphatase, FBPase and glucose-6-phosphatase, G6Pase), carbohydrate breakdown (intestinal α-glucosidases), and insulin sensitivity (protein tyrosine phosphatase 1B, PTP-1B) was evaluated. Acute toxicity tests were carried out and HPLC-SQ-TOF was used to analyze the chemical profiles of the plant extracts. RESULTS: In the fasting state, T. b, S. h, and E. b were as effective as glibenclamide in lowering blood glucose levels in hyperglycemic rats. Moreover, all three suppressed G6Pase and FBPase enzymatic activity by 90-97% and 80-91%, respectively. On the other hand, significant postprandial hypoglycemic efficacy was observed for E. b, S. h, and T. b. Based on the AUC values, T. b caused a reduction comparable to the therapeutic efficacy of repaglinide. When investigating the possible mechanisms of action involved in this activity, E. b, S. h, and T. b showed significant inhibition of PTP-1B in vitro (>70%). Finally, all plant extracts showed no signs of acute toxicity. Several compounds that may contribute to biological activities were identified, including phenolic acids and flavonoid glycosides. CONCLUSIONS: The present study supports the traditional use of T. b, E. b and S. h for the control of diabetes in the fasting and postprandial state. Moreover, these plants were found to be rich in bioactive compounds with hypoglycemic and antihyperglycemic activities. On the other hand, J. p, showed a modest effect only in the fasting state and after 90 min. Further studies are needed to expand these results by analyzing the chemical composition and using complementary experimental models.

A dermatological assessment of pediatric patients with tuberous sclerosis complex (TSC)

Abstract Background Tuberous sclerosis complex (TSC) is a multisystem neurocutaneous syndrome with variable phenotypes. Recent updates of TSC diagnostic criteria reaffirmed the defined genetic diagnostic criterion as the finding of a pathogenic DNA alteration in either TSC1 or TSC2 genes. It also slightly modified definite clinical diagnostic criteria. TSC-associated skin lesions in infancy are important clinical signs to select individuals with possible TSC for a closer clinical follow-up and genetic testing. Objective To raise awareness of the updated TSC diagnosis criteria; to assess the frequency of skin lesions in TSC patients as well as the first dermatological presentation; and to associate the findings with either TSC1 or TSC2 mutations. Methods Observational cross-sectional study. Clinical and genetic data were retrospectively collected from 37 TSC patients from a Brazilian University Hospital. Patients with skin signs were examined and prospectively assessed for 12 months. Results The earliest cutaneous lesions were hypomelanotic macules, which together with angiofibromas were the most frequent dermatological lesions. The total pathogenic DNA alteration ratio between TSC2 and TSC1 genes was 8:1. The frequency of a TSC2 pathogenic variant was 10-fold greater in the presence of ungual fibromas. Study limitations Small sample and a limited number of patients with TSC1 pathogenic variants. Conclusion Clinicians should be knowledgeable about TSC updated diagnostic criteria. Patients need to be followed up by a multidisciplinary team and treated accordingly. Early detection of cutaneous lesions is important for TSC diagnosis. A significant association between TSC2 gene pathogenic alterations and ungual fibromas is described.

Factors associated with non-pathogenic antibodies against desmoglein-3 in pemphigus foliaceus

Abstract Background Anti-desmoglein (Dsg)1 is produced in pemphigus foliaceus (PF), affecting exclusively the skin. Pemphigus vulgaris (PV) shows the production of anti-Dsg3 in the mucosal form, and anti-Dsg1 and 3 in the mucocutaneous form. Anti-Dsg3 autoantibodies have been rarely reported in PF. Objectives To determine the factors associated with the production and pathogenicity of anti-Dsg3 in PF. Methods Comparative analytical study of three patients groups: 16 PF-anti-Dsg3+, and 42 PF-anti-Dsg3(-) and 22 PV treatment-naïve cases. Serum was used in the anti-Dsg1 and 3 ELISA, and in immunoblotting (IB) with human epidermis extract. The expression of Dsg1 and 3 in paraffin sections was analyzed by immunohistochemistry (IHC). HLA-DRB1 alleles were compiled from a database. Results In the PF-anti-Dsg3+ group: age range similar to that of the PV group (p > 0.9999); predominance of the generalized form of PF (p = 0.002); anti-Dsg3 titers lower than those of PV (p < 0.0001); IB confirmed Dsg3 identification in one (8.33%) of 12 patients; IHC showed exclusive cytoplasmic internalization of Dsg1; HLA-DRB1 alleles of susceptibility to PF, with the absence of alleles associated with PV, in the five typed patients. Study limitations Most of the patients in the PF-anti-Dsg3+ group were undergoing treatment. Conclusion The presence of anti-Dsg3 antibodies in PF was related to older age (comparable to that of PV) and the generalized form of PF. The non-pathogenicity of anti-Dsg3 antibodies in PF can be attributed to the low serum anti-Dsg3 titers, the lack of Dsg3 internalization as detected by IHC, and the absence of PV-associated HLA-DRB1 alleles.

Rare primary vasculitis: update on multiple complex diseases and the new kids on the block.

Systemic vasculitis is a group of rare diseases that share an essential characteristic: inflammation of blood vessel walls. This injury occurs during the disease course, but specific features vary for each entity. In this paper, we will address relevant aspects of the newest monogenic mutation vasculitis, such as deficiency of adenosine deaminase 2 (ADA2) and VEXAS syndrome (UBA1), and other relevant vasculitis, such as Cogan syndrome and Susac syndrome that may share some similarities with them.

Genomic alterations in retinoblastoma tumors of Argentine patients.

INTRODUCTION: Retinoblastoma is initiated by inactivation of RB1 gene, but additional alterations may be required for tumor progression. Substitution and INDEL variants in different genes, aside RB1, are infrequent, while large copy number variants (CNVs) like gains on 1q, 2p, 6p and loss on 16q are common, they include oncogenes or tumor suppressors and are typical of retinoblastoma. AIM: To provide the molecular profile that is useful for prognosis and understanding of retinoblastoma development. METHODS: To identify genomic variants in six retinoblastoma tumors whole exome sequencing and informatic analysis were performed. RESULTS: RB1 was the only gene with nonsense or frameshift mutations. SNVs in other 11 genes were missense and at non-canonical splice-sites, all nonpathogenic. CNVs, similar to those reported, were identified in all retinoblastoma tumors. The most frequent were 1q gain and 16q loss. Additionally, deletions were identified on 13q, including RB1 gene, and on the X chromosome, including BCOR gene, the most frequently mutated, after RB1, in retinoblastoma. The number of CNVs detected in each tumor was between 1 and 7, depending on the age at diagnosis. CONCLUSION: The analysis of genomic alterations in retinoblastoma is useful to understand the severity of tumor progression and to apply appropriate treatments.

Characterization of SNPs in meat quality-related genes in Argentine Coastal Creole pigs and their potential as a porcine genetic resource.

The Coastal Creole pigs in Argentina are predominantly found in the wild and can trace their lineage directly back to the Iberian breeds introduced by Spanish colonizers. They currently stand as the sole Creole breed in the country recognized by the FAO. However, there exists a dearth of studies assessing their genetic potential within the swine industry. Therefore, this study aimed to genetically characterize the meat quality of Coastal Creole pigs based on seven single nucleotide polymorphisms (SNPs) within the Ryr1, PRKAG3, MC4R, H-FABP, and CAST genes. A total of N = 158 samples were collected from specimens distributed along the coastal region. Our findings revealed all loci to exhibit polymorphism, underscoring the population's remarkable genetic diversity. Furthermore, a higher frequency of alleles favorable for the PRKAG3191I>V/200R>Q, MC4R1426A>G, CAST76872G>A, and Ryr11843C>T genes was observed, while alleles unfavorable predominated for H-FABP1811G>C and CAST638Ser>Arg. The results obtained in this research are highly encouraging, reflecting the genetic potential of these pigs to be utilized in swine production programs.

Analysis of the relationship between resistin with prognosis, cell migration, and p38 and ERK1/2 activation in breast cancer.

Obesity increases the risk and mortality of breast cancer through dysregulated secretion of proinflammatory cytokines and tumor adipokines that induce an inflammatory breast microenvironment. Resistin is an adipokine secreted by adipocytes, immune cells, and predominantly macrophages, which contributes to cancer progression, but its molecular mechanism in cancer is not completely described. In this study, we analyzed the relationship of resistin on breast cancer prognosis and tumor progression and the effect in vitro of resistin on p38 and ERK1/2 activation in breast cancer cell lines. By bioinformatic analysis, we found that resistin is overexpressed in the basal subtype triple-negative breast cancer and is related to poor prognosis. In addition, we demonstrated a positive correlation between RETN and MAPK3 expression in basal triple-negative breast cancer. Importantly, we found amplifications of the RETN gene in at least 20 % of metastatic samples from patients with breast cancer. Most samples with RETN amplifications metastasized to bone and showed high expression of IL-8 (CXCL8) and IL-6 (IL6). Finally, resistin could be considered a prognostic marker for basal triple-negative breast cancer, and we also proposed the possibility that resistin-induced cell migration involves the activation of MAPK in breast cancer cells.

Mantle Cell Lymphoma in the Oral Cavity: Exploring the Differential Microscopic Diagnosis of a Rare Case.

Mantle cell lymphoma (MCL) is a rare subtype of B-cell non-Hodgkin's lymphoma (NHL), which generally has an aggressive course. Its pathophysiology seems to be related with the malignant transformation of B-cell mantle zone lymphocytes due to the CCND1 rearrangement. The occurrence of MCL in the oral cavity is especially rare. In this report, we present an exceptional case of oral MCL diagnosed in the palate in a 56-year-old male patient, highlighting its distinct morphological and immunohistochemical features that may assist in the accurate diagnosis.

Phenotypic Heterogeneity of Patients With Marfan Syndrome in Puerto Rico: A Case Series.

PURPOSE: Previous studies have reported on the cardiovascular, ocular, and musculoskeletal findings in patients with Marfan syndrome (MFS). This study aims to report the ocular and genotypic findings in patients with the syndrome in Puerto Rico. PATIENTS AND METHODS: A chart review of a cohort of patients with the syndrome from Puerto Rico was done. Patients were examined by at least one of the authors (NJI). Fibrillin-1 (FBN1) full gene sequencing was done to all patients (Laboratory for Molecular Medicine, Center for Genetics and Genomics, Cambridge, MA). This study was approved by the Institutional Review Board of the Universidad Central del Caribe (approval number: 2024-07).  Results: Six patients aged 28-79 years were examined. There were seven female and three male patients. The average visual acuity was 0.49 and 0.52 in the right eye (OD) and left eye (OS), respectively. The average refraction (spherical equivalent) was -1.28 sph OD and -1.07 sph OS. The average intraocular pressure was 14 mmHg in both eyes (OU). A patient had a dislocated lens OD; a patient had lens dislocation OU; and a patient had prosthesis OD and aphakia OS. Upon optical coherence tomography (OCT), the retinal nerve fiber layer (RNFL) average was 75.86 µm OD and 81.85 ​​µm OS; the average cup-to-disc (C/D) ratio was 0.41 and 0.35 in the right and left eye, respectively. Upon visual field testing, the average mean deviation (MD) was -6.27 dB OD and -8.55 dB OS. CONCLUSIONS: Our findings underscore the significant phenotypic and genotypic heterogeneity of patients with MFS in Puerto Rico. The identification of several mutations in the FBN1 gene in the Puerto Rican population demonstrates the need for an up-to-date approach to diagnose and co-manage patients with the syndrome. This study contributes to a deeper understanding of the genetic heritage of patients with the syndrome and highlights the potential for personalized therapeutic interventions.

Abf1 negatively regulates the expression of EPA1 and affects adhesion in Candida glabrata.

Introduction. Adherence is a major virulence trait in Candida glabrata that, in many strains, depends on the EPA (epithelial adhesin) genes, which confer the ability to adhere to epithelial and endothelial cells of the host. The EPA genes are generally found at subtelomeric regions, which makes them subject to subtelomeric silencing. In C. glabrata, subtelomeric silencing depends on different protein complexes, such as silent information regulator and yKu complexes, and other proteins, such as Repressor/activator protein 1 (Rap1) and Abf1. At the EPA1 locus, which encodes the main adhesin Epa1, we previously found at least two cis-acting elements, the protosilencer Sil2126 and the negative element, that contribute to the propagation of silencing from the telomere to the subtelomeric region.Hypothesis. Abf1 binds to the regulatory regions of EPA1 and other regions at the telomere E-R, thereby negatively regulating EPA1 transcription.Aim. To determine whether Abf1 and Rap1 silencing proteins bind to previously identified cis-acting elements on the right telomere of chromosome E (E-R subtelomeric region), resulting in negative regulation of EPA1 transcription and infer Abf1 and Rap1 recognition sites in C. glabrata.Methodology. We used chromatin immunoprecipitation (ChIP) followed by quantitative PCR to determine the binding sites for Abf1 and Rap1 in the intergenic regions between EPA1 and EPA2 and HYR1 and EPA1, and mutants were used to determine the silencing level of the EPA1 promoter region.Results. We found that Abf1 predominantly binds to the EPA1 promoter region, leading to negative regulation of EPA1 expression. Furthermore, the mutant abf1-43, which lacks the last 43 amino acids at its C-terminal end and is defective for subtelomeric silencing, exhibits hyperadherence to epithelial cells in vitro compared to the parental strain, suggesting that EPA1 is derepressed. We also determined the motif-binding sequences for Abf1 and Rap1 in C. glabrata using data from the ChIP assays.Conclusion. Together these data indicate that Abf1 negatively regulates EPA1 expression, leading to decreased adhesion of C. glabrata to epithelial cells.

Therapeutic opportunities in targeting the protective arm of the renin-angiotensin system to improve insulin sensitivity: a mechanistic review.

In recent years, the knowledge of the physiological and pathophysiological roles of the renin-angiotensin system (RAS) in glucose metabolism has advanced significantly. It is now well-established that blockade of the angiotensin AT1 receptor (AT1R) improves insulin sensitivity. Activation of the AT2 receptor (AT2R) and the MAS receptor are significant contributors to this beneficial effect. Elevated availability of angiotensin (Ang) II) for interaction with the AT2R and increased Ang-(1-7) formation during AT1R blockade mediate these effects. The ongoing development of selective AT2R agonists, such as compound 21 and the novel Ang III peptidomimetics, has significantly advanced the exploration of the role of AT2R in metabolism and its potential as a therapeutic target. These agents show promise, particularly when RAS inhibition is contraindicated. Additionally, other RAS peptides, including Ang IV, des-Asp-Ang I, Ang-(1-9), and alamandine, hold therapeutic capability for addressing metabolic disturbances linked to type 2 diabetes. The possibility of AT2R heteromerization with either AT1R or MAS receptor offers an exciting area for future research, particularly concerning therapeutic strategies to improve glycemic control. This review focuses on therapeutic opportunities to improve insulin sensitivity, taking advantage of the protective arm of the RAS.

Immunostaining for Mismatch Repair Complex Proteins Impacts on Clinical-Pathological Characteristics and Prognosis of Adenoid Cystic Carcinoma of Salivary Glands.

OBJECTIVE: To evaluate the influence of MMR proteins on clinicopathological characteristics and prognosis of salivary gland adenoid cystic carcinoma (ACC). METHOD: The solid pattern of ACC showed lower expression for MSH2 (p = 0.039). Significant imbalance in MSH2/MSH6 immunostaining was observed in all histological patterns (p < 0.001), and imbalance in PMS2/MLH1 immunostaining was observed in the cribriform pattern (p = 0.011). The presence of capsule was associated with high expression of MSH6 (p = 0.019), MLH1 (p = 0.045) and PMS2 (p = 0.009). The absence of cribriform pattern (p = 0.002) and capsule pattern (p = 0.025), as well as low expression for MSH6 (p = 0.006) and PMS2 (p = 0.037) were associated with lower overall survival. In multivariate analysis, loss of MSH2 (p = 0.039) and MLH1 (p = 0.017) were significantly associated with worse overall survival. RESULTS: Twenty-four ACC were clinical-pathologically evaluated and we perform immunohistochemistry for MSH2, MSH6, PMS2 and MLH1. Percentage counting of positive cells was performed in 10 fields of each histological pattern (cribriform, tubular and solid) and the averages of the 30 fields were considered for evaluation with other clinical-pathological variables (Kruskal-Wallis/Dunn, Friedman/Dunn, chi-square, Log-Rank Mantel-Cox tests and Cox regression; SPSS v20.0, p < 0.05). DISCUSSION: Salivary glands' ACC shows imbalance of the MMR complex and loss of expression of its components is associated with the overall survival of these patients.

Bio-adsorption of Fe (II) by dry biomass of metal-tolerant haloarchaeon Haloferax alexandrinus GUSF-1.

Mining-associated activities result in iron pollution exceeding the acceptable limit of 0.3 mg L- 1 and are rampant in estuarine soil and water bodies that harbor halophilic microorganisms. Biotechnologies are underway to unveil the concentrations and recover the metals that skip existing physico-chemical methods. Concerning this, the present study describes for the first time the development of a bio-adsorption batch system using dried cells of Haloferax alexandrinus GUSF-1 for Fe (II) from saline water under microaerophilic conditions. A maximum of 99.5% Fe (II) was adsorbed at pH 6.0, 30 ºC in 3 h with 92% efficiency over three adsorption-desorption cycles with saturation and pseudo-second-order kinetics and heterogeneity of Freundlich model having KF of 1.38 mg g- 1 with the n value of 0.96. Adsorbed Fe (II) by the cells was detected by scanning electron microscopy. The involvement of the carboxyl, amino, hydroxyl, and phosphate groups of the cells in interaction with the metal ions was detected by infrared spectroscopy. Conclusively, the study is the first report of whole dried cells mediated metal adsorption by the haloarcheon Haloferax alexandrinus GUSF-1 which acts as promising candidate for metal clean-up strategy and bioremediation in hypersaline ecosystems.

Immunohistochemical evaluation of cyclin D1 and p63 in odontogenic keratocyst and unicystic ameloblastoma.

INTRODUCTION: Odontogenic keratocyst (OKC) and unicystic ameloblastoma (UA) are lesions of odontogenic origin. Both lesions are morphologically cysts. However, they are classified as developmental cysts and epithelial odontogenic tumours, respectively. Cyclin D1 (CCD1) dysregulation is associated with oncogenic activity and malignancies, while tumour protein p63 (p63) alterations are associated with tumourigenesis. AIM: To evaluate and compare the protein expression of CCD1 and p63 in sporadic OKC (OKC-sp), syndromic OKC (OKC-sy), and UA. MATERIAL AND METHODS: 45 cases from the Anatomical Pathology Department, Faculty of Dentistry, University of Chile were analysed and divided into groups: OKC-sp (n=15), OKC-sy (n=15) and UA (n=15), the latter categorised into intraluminal and/or luminal (n=7) and mural (n=8). Immunohistochemical staining for CCD1 and p63 proteins was performed from paraffin-embedded sections. Statistical analysis included the Shapiro-Wilk test, one-way ANOVA with Tukey's multiple comparisons, and Spearman's correlation coefficient (p<0.05). RESULTS: There was an involvement mainly in women in the mandibular area, and a high frequency of jaw expansion, especially in the mural UA. P63 protein expression was higher than CCD1 in all cystic lesions, particularly in mural UA (p<0.001). No correlation was found between CCD1 and p63 expression. CONCLUSION: P63 may serve as a valuable marker for evaluating cell proliferative activity in odontogenic cystic lesions, providing insights into the aggressive behaviour of mural UA.

Orexin mechanisms in the prelimbic cortex modulate the expression of contextual conditioned fear.

RATIONALE: Despite the existing anatomical and physiological evidence pointing to the involvement of orexinergic projections from the lateral hypothalamus (LH) in regulating fear-related responses, little is known regarding the contribution of the orexin system in the prelimbic cortex (PL) on contextual fear. OBJECTIVES: We investigated the role of orexin-A (OrxA) and orexin type 1 receptors (Orx1R) in the PL during the expression of contextual conditioned fear in mice. METHODS: Neural tract tracing of the LH-PL pathway and Orx1R immunoreactivity in the PL of C57BL/6 male mice were performed. In a pharmacological approach, the animals were treated with either the Orx1R selective antagonist SB 334,867 (3, 30, and 300 nM/0.1 µL) or OrxA (28, 70, and 140 pmol/0.1 µL) in the PL before the test session of contextual fear conditioning. RESULTS: Neural tract tracing deposits in the LH showed some perikarya, mainly axons and terminal buttons in the PL, suggesting LH-PL reciprocate pathways. Furthermore, we showed a profuse network comprised of Orx1R-labeled thin varicose fibers widely distributed in the same field of LH-PL pathways projection. The selective blockade of Orx1R with SB 334,867 at 30 and 300 nM in the PL caused a decrease in freezing response, whereas the treatment with OrxA at 140 pmol promoted an increase in freezing response. CONCLUSION: In summary, these data confirmed an anatomical link between LH and PL, established the presence of Orx1R in the PL, and a modulatory role of the orexin system in such structure, possibly mainly via Orx1R, during contextual fear conditioning.

Reaction force constant as a descriptor of the principle of non-perfect synchronization.

CONTEXT: In this study, a small set of 1,3-dipolar cycloaddition reactions that proceed at the same exothermicity is presented. Our main objective was to extend the application of the reaction force constant concept to gain an understanding of the reactivity principles. Inspired by a recent article where we show that the Bell-Evans-Polanyi principle is fulfilled under the condition of an equal degree of (a)synchronicity, here, we demonstrate that the reaction force constant is also a suitable descriptor to quantify the principle of non-perfect synchronization proposed by Bernasconi as a way to understand deviations from the Bell-Evans-Polanyi principle. METHODS: Reaction profiles V ( ξ ) , F ( ξ ) , and κ ( ξ ) were performed at the B3LYP/6-31G(d,p) level of theory. The stabilizing interactions were characterized using the energy decomposition analysis combined with the natural orbitals for chemical valence, EDA-NOCV, method. The present work was done using Gaussian 09 and Multiwfn programs.

Parkinson biomarker determination with an Au microflower-enhanced electrochemical immunosensor using non-Faradaic capacitance measurements.

This work comprehends the development and characterization of a carbon black-based electrode modified with Au microflowers to increase its effect as a capacitance biosensor for the determination of PARK7/DJ-1. Due to its high surface-to-volume ratio and biocompatibility, Au particles are suitable for antibody binding, and by monitoring surface capacitance, it is possible to identify the immune-pair interaction. Au microflowers allowed the adequate immobilization of Parkinsonian-related proteins: PARK7/DJ-1 and its antibody. The protein is associated with several antioxidant mechanisms, but its abnormal concentrations or mutations can be the cause of the loss of dopaminergic neurons, leading to Parkinson's disease. The device was characterized by scanning electron microscopy and cyclic voltammetry, revealing the flower-like structures and the electrochemically-interest enhancements they provide, such as increased heterogeneous electron transfer rate coefficient and electroactive area. The self-assembled monolayers of different molecules were optimized with the aid of 22 central composite experiments and a linear calibration curve was obtained between 0.700 and 120 ng mL-1 of PARK7/DJ-1, with a limit of detection of 0.207 ng mL-1. The data confirms that the addition of Au microflowers enhanced the electrochemical signal of the device, as well as allowed for the determination of an early stage Parkinson's disease biomarker with appreciable analytical performance.