Protective effects of D-005, a lipid extract from Acrocomia crispa fruits, against ischemia/reperfusion-induced acute kidney injury in rats

Ambar Oyarzábal-Yera,Sandra Rodríguez-Salgueiro,Nelson Merino-García,Leyanis Ocaña-Nápoles,Lucía González-Núñez,Licet Mena-Valdés,Zullyt Zamora-Rodríguez,José A. Medina-Pírez,Sonia Jiménez-Despaigne,V 대한신장학회 2019 Kidney Research and Clinical Practice Vol.38 No.4

Background: Acute kidney injury (AKI) induced by renal ischemia/reperfusion (IR) is associated with enhanced production of reactive oxygen species in renal tissues. D-005, a lipid extract obtained from Acrocomia crispa fruit, has previously shown antioxidant effects. The aim of this work was to evaluate the effects of D-005 on renal IR-induced AKI in rats. Methods: Rats were randomized into seven groups including a negative control group (vehicle) without AKI and six groups with renal IR-induced AKI as follows: a positive control (vehicle); D-005 treatment at 25, 100, 200, or 400 mg/kg; and dexamethasone at 3 mg/kg. All treatments were orally administered as single doses 1 hour before AKI induction. Biomarkers (serum creatinine, urea, and uric acid concentrations), oxidative variables, and histopathological AKI changes were evaluated in blood and kidney tissues. Results: All D-005 doses protected against IR-induced AKI in rats by significantly decreasing biomarkers and histopathological AKI changes as assessed by reduced serum concentrations of creatinine, urea, and uric acid. In addition, all D-005 doses decreased tubular damage, as shown by fewer detached cells and casts in the tubular lumen. D-005 reversed oxidation disturbance markers by decreasing malondialdehyde and sulfhydryl group concentrations in plasma and in kidney homogenates and by increasing kidney catalase activity. Dexamethasone, the reference substance, protected against IR-induced AKI in rats by reducing biochemical and histological variables of renal damage in a similar manner. Conclusion: Administration of single oral doses of D-005 markedly and significantly protected against renal IR-induced AKI, possibly due to its known antioxidant effects.

Subclinical versus advanced forms of alcohol-related liver disease: Need for early detection

Concepción Gómez-Medina,Luma Melo,David Martí-Aguado,Ramón Bataller 대한간학회 2023 Clinical and Molecular Hepatology(대한간학회지) Vol.29 No.1

Alcohol-related liver disease (ALD) consists of a wide spectrum of clinical manifestations and pathological features, ranging from asymptomatic patients to decompensated cirrhosis and hepatocellular carcinoma. Patients with heavy alcohol intake and advanced fibrosis often develop a subacute form of liver failure called alcohol-induced hepatitis (AH). Globally, most patients with ALD are identified at late stages of the disease, limiting therapeutic interventions. Thus, there is a need for early detection of ALD patients, which is lacking in most countries. The identification of alcohol misuse is hampered by the existence of alcohol underreporting by many patients. There are useful biomarkers that can detect recent alcohol use. Moreover, there are several non-invasive techniques to assess the presence of advanced fibrosis among patients with alcohol misuse, which could identify patients at high risk of liver related events or early death. In this review, we discuss differences between early stages of ALD and AH as the cornerstone of advanced forms. A global overview of epidemiological, anthropometric, clinical, analytical, histological, and molecular differences is summarized in this article. We propose that campaigns aimed at identifying patients with subclinical forms can prevent the development of life-threatening forms.

Weak screening of a large dipolar molecule adsorbed on graphene

Kong, Lingmei,Perez Medina, G.J.,Coló,n Santana, J.A.,Wong, F.,Bonilla, M.,Coló,n Amill, D.A.,Rosa, L.G.,Routaboul, L.,Braunstein, P.,Doudin, B.,Lee, Chang-Mook,Choi, Jaewu,Xiao, Jie,Dowbe Elsevier 2012 Carbon Vol.50 No.5

<P><B>Abstract</B></P><P>We compare the electronic structure of a quinonoid zwitterionic type molecule adsorbed on both gold and graphene on copper substrates. This (6<I>Z</I>)-4-(butylamino)-6-(butyliminio)-3-oxocyclohexa-1,4-dien-1-olate, C<SUB>6</SUB>H<SUB>2</SUB>(⋯_NHR)<SUB>2</SUB>(⋯_O)<SUB>2</SUB> where R=<I>n-</I>C<SUB>4</SUB>H<SUB>9</SUB>, film is made of small molecules with a large intrinsic dipole of 10Debyes. We find that the photoemission and inverse photoemission final states are well screened for these dipolar molecules on gold. This is not observed when they are adsorbed on graphene on copper. This weaker screening results in a larger highest occupied molecular orbital to lowest unoccupied molecular orbital gap for the molecules on graphene.</P>

Rheology and gel point of the enzymatic hydrolysis of urea in the presence of urease

R. Serrato-Millán,L. Medina-Torres,F. Calderas,B.L. España-Sánchez,M. Estevez,A.R. Hernandez-Martínez,M. Cruz-Soto,I.C. Sánchez,R. Gómez-García,I. Sánchez-Betancourt,M.C. Velasquillo-Martínez,G. Luna- 한국유변학회 2017 Korea-Australia rheology journal Vol.29 No.1

This study reports on the rheology of the gelation kinetics of raw chitosan (CTS) solutions (2% w/v) produced by enzymatic hydrolysis of urea at different urea concentrations (40, 50, 60, 80, and 100 mM) in the presence of urease at 1 U/mL. Viscoelastic parameters and pH values were evaluated during gelation process and the rheological properties of CTS hydrogels produced were monitored after 24 h at 37°C to simulate human body temperatures. pH measurements suggest that above some critical urea concentration (50 mM) the time required (tgel) to reach the critical pH gelation shows no dependence on urea concentration (tgel was ca. 70 minutes). Above 50 mM of urea concentration, CTS hydrogels exhibit an elastic modulus G' higher than the viscous modulus G'' with no frequency dependence characteristic of a gel behavior. Gelation kinetics analyzed by rheology suggest that the G' (i.e., structure) development depends on urea concentration during solution neutralization.

Transcription Factors Tec1 and Tec2 Play Key Roles in the Hyphal Growth and Virulence of Mucor lusitanicus Through Increased Mitochondrial Oxidative Metabolism

Alejandre-Castañeda Viridiana,Patiño-Medina J. Alberto,Valle-Maldonado Marco I.,García Alexis,Ortiz-Alvarado Rafael,Ruíz-Herrera León F.,Castro-Cerritos Karla Viridiana,Ramírez-Emiliano Joel,Ramírez-D 한국미생물학회 2023 The journal of microbiology Vol.61 No.12

Mucormycosis is a lethal and difficult-to-treat fungal infection caused by fungi of the order Mucorales. Mucor lusitanicus, a member of Mucorales, is commonly used as a model to understand disease pathogenesis. However, transcriptional control of hyphal growth and virulence in Mucorales is poorly understood. This study aimed to investigate the role of Tec proteins, which belong to the TEA/ATTS transcription factor family, in the hyphal development and virulence of M. lusitanicus. Unlike in the genome of Ascomycetes and Basidiomycetes, which have a single Tec homologue, in the genome of Mucorales, two Tec homologues, Tec1 and Tec2, were found, except in that of Phycomyces blakesleeanus, with only one Tec homologue. tec1 and tec2 overexpression in M. lusitanicus increased mycelial growth, mitochondrial content and activity, expression of the rhizoferrin synthetase-encoding gene rfs, and virulence in nematodes and wax moth larvae but decreased cAMP levels and protein kinase A (PKA) activity. Furthermore, tec1- and tec2-overexpressing strains required adequate mitochondrial metabolism to promote the virulent phenotype. The heterotrimeric G beta subunit 1-encoding gene deletant strain (Δgpb1) increased cAMP-PKA activity, downregulation of both tec genes, decreased both virulence and hyphal development, but tec1 and tec2 overexpression restored these defects. Overexpression of allele-mutated variants of Tec1(S332A) and Tec2(S168A) in the putative phosphorylation sites for PKA increased both virulence and hyphal growth of Δgpb1. These findings suggest that Tec homologues promote mycelial development and virulence by enhancing mitochondrial metabolism and rhizoferrin accumulation, providing new information for the rational control of the virulent phenotype of M. lusitanicus.

Assessment of Austenite Static Recrystallization and Grain Size Evolution during Multipass Hot Rolling of a Niobium-Microalloyed Steel

Manuel Gómez,Lucía Rancel,Sebastián F. Medina 대한금속·재료학회 2009 METALS AND MATERIALS International Vol.15 No.4

Double-deformation isothermal tests and multipass continuous-cooling hot torsion tests were used to study the evolution of austenite microstructures during isothermal and non-isothermal hot deformation of an Nb microalloyed steel. These tests, coupled with microstructural characterization, have verified that the no-recrystallization temperature (Tnr) corresponds roughly to the temperature where recrystallization starts to be incomplete during rolling. An accurate method to estimate the recrystallized fraction during hot rolling based on stress-strain data, and which does not require metallographic studies, is proposed. The results of this method have been successfully compared to metallographic measurements, the values of non-isothermal fractional softening and the accumulated stress measured in the plots of mean flow stress (MFS) versus the inverse of temperature. A remarkable austenite grain refinement occurs in the first hot rolling passes after reheating. The correlation of isothermal and continuous cooling tests is better understood if the effect of grain size on recrystallization and precipitation is taken into account. Double-deformation isothermal tests and multipass continuous-cooling hot torsion tests were used to study the evolution of austenite microstructures during isothermal and non-isothermal hot deformation of an Nb microalloyed steel. These tests, coupled with microstructural characterization, have verified that the no-recrystallization temperature (Tnr) corresponds roughly to the temperature where recrystallization starts to be incomplete during rolling. An accurate method to estimate the recrystallized fraction during hot rolling based on stress-strain data, and which does not require metallographic studies, is proposed. The results of this method have been successfully compared to metallographic measurements, the values of non-isothermal fractional softening and the accumulated stress measured in the plots of mean flow stress (MFS) versus the inverse of temperature. A remarkable austenite grain refinement occurs in the first hot rolling passes after reheating. The correlation of isothermal and continuous cooling tests is better understood if the effect of grain size on recrystallization and precipitation is taken into account.

Nonlinear bending vibration of a prestressed thick plate

Francisco J. Nieves,Ana Bayón,Francisco Gascón,Rafael Medina,Félix Salazar 대한기계학회 2018 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.32 No.4

In this paper, the flexural vibration frequency in the antisymmetric mode of a thick plate as a function of the amplitude of the vibration and the axial force applied is investigated. With this aim, the theory of geometrically nonlinear deformation of second order and an optimized three-dimensional Ritz method are used. The plate is homogeneous, elastically linear, free from any constraints, and subjected to axial forces uniformly distributed on two of its opposite sides. Several approaches are discussed. First, the problem based on finite stress and infinitesimal strains is solved. Second, the deformation energy is assumed as the energy in the initial state plus the vibration energy of small or large amplitude. Third, without assumptions about the size of the deformation and of the vibration amplitude, the theory of nonlinear deformation is employed. Finally, numerical calculations for free vibration are compared with experimental results, including their systematic uncertainties.

Development of a real-time SYBR Green PCR assay for the rapid detection of Dermatophilus congolensis

Alfredo García,Remigio Martínez,José Manuel Benitez-Medina,David Risco,Waldo Luis García,Joaquín Rey,Juan Manuel Alonso,Javier Hermoso de Mendoza 대한수의학회 2013 Journal of Veterinary Science Vol.14 No.4

Methods such as real time (RT)-PCR have not been developed for the rapid detection and diagnosis of Dermatophilus (D.) congolensis infection. In the present study, a D. congolensis-specific SYBR Green RT-PCR assay was evaluated. The detection limit of the RT-PCR assay was 1 pg of DNA per PCR reaction. No cross-reaction with nucleic acids extracted from Pseudomonas aeruginosa,Mycobacterium tuberculosis, Staphylococcus aureus, or Austwickia chelonae was observed. Finally, the RT-PCR assay was used to evaluate clinical samples collected from naturally infected animals with D. congolensis. The results showed that this assay is a fast and reliable method for diagnosing dermatophilosis.

A home-based exercise program for temporomandibular joint osteoarthritis: pain, functionality, and joint structure

Salvador Israel Macías-Hernández,Juan Daniel Morones-Alba,Irene Tapia-Ferrusco,Oscar Benjamín Vélez-Gutiérrez,Cristina Hernández-Diaz,Tania Inés Nava-Bringas,Eva Cruz-Medina,Lya Contreras-del Toro,Ma. 대한구강악안면외과학회 2022 대한구강악안면외과학회지 Vol.48 No.1

Objectives: Osteoarthritis (OA) is the most prevalent and disabling joint disease in the world. Temporomandibular joint (TMJ) exercise is a widely used treatment and could be a beneficial and long-term tool for treating TMJ OA. The present study aims to evaluate the effects of therapeutic exercise in the conservative treatment of TMJ OA. Materials and Methods: A single-group experimental pre-post test was performed. We included patients who met the diagnostic criteria for TMJ OA. Outcome variables were pain intensity (visual analogue scale), functionality (Helkimo index), and structural changes (ultrasound). Follow-up peri-ods were at months 1, 3, and 6. The intervention included a home-based program with thermotherapy, manual therapy, and therapeutic exercise during the entire follow-up period. Results: We included 15 patients and 26 joints, all women with a median age of 57 years (range, 49-62 years). Median change in pain intensity on joint palpation, mouth opening, and at rest at the first month was 47.5 mm, 51 mm, and 60 mm, respectively, and 48 mm, 49.5 mm, and 42.5 mm, at six months (P=0.001). The Helkimo index showed significant improvement in medians from baseline severe dysfunction (17 points) to minimal dys-function at three and six months (2 points) (P=0.001). Ultrasound showed improved disc position. Conclusion: This study demonstrated significant improvements in pain, function, and joint disc position and represents a valuable tool for the long-term treatment of patients with TMJ OA.

Adaptive Nonlinear Control of Induction Motor

Gerardo V. Guerrero Ramírez,Luis G. Vela Valdés,Manuel Adam Medina,Carlos D. García Beltrán,Cesar A. Villanueva López 제어·로봇·시스템학회 2011 International Journal of Control, Automation, and Vol.9 No.1

This work addresses the problem of controlling a rigid arm (one degree of freedom robot manipulator) directly driven by an induction motor. A Lyapunov-based adaptive nonlinear controller is designed. The developed controller compensates for parametric uncertainty associated with the resistance of the rotor windings and it is capable to track asymptotically a trajectory for an angular position keeping all the internal signals bounded and guarantees the asymptotical stability of the system. Simulations are presented to illustrate the performance of this controller.