Role of the microtubules in the electrical activity of the primary cilium of renal epithelial cells.

The primary cilium is a non-motile sensory organelle that transduces environmental cues into cellular responses. It comprises an axoneme, a core of nine doublet microtubules (MTs) coated by a specialized membrane populated by receptors, and a high density of ion channels. Dysfunctional primary cilia generate the pathogenesis of several diseases known as ciliopathies. However, the electrical role of MTs in ciliary signaling remains largely unknown. Herein, we determined by the patch clamp technique the electrical activity of cytoplasmic and axonemal MTs from wild-type LLC-PK1 renal epithelial cells. We observed electrical oscillations with fundamental frequencies at ∼39 Hz and ∼93 Hz in sheets of cytoplasmic MTs. We also studied in situ and isolated, intact and Triton X-permeabilized primary cilia, observing electrical oscillations with peak frequencies at either 29-49 Hz (non-permeabilized) or ∼40-49 Hz (permeabilized) and ∼93 Hz (both). We applied Empirical Mode Decomposition (EMD), Continuous Wavelet Transform (CWT), and Cross-Correlation Analysis (CCA) to assess the differences and the coherence in the Time-Frequency domains of electrical oscillations between cytoplasmic and axonemal MTs. The data indicate that axonemal and cytoplasmic MTs show different patterns of electrical oscillations preserving coherence at specific frequency peaks that may serve as electromagnetic communication between compartments. Further, the electrical behavior of axonemal MTs was modified by siRNA deletion of polycystin-2 (PC2), which lengthens primary cilia, thus linking ciliary channels to the morphological and electrical behavior of cilia in ciliopathies. The encompassed evidence indicates that the primary cilium behaves as an electrical antenna, with an excitable MT structure that produces electrical oscillations whose synchronization and propagation constitute a novel cell signaling mechanism.

The electrical properties of isolated microtubules.

This study examines the electrical properties of isolated brain microtubules (MTs), which are long hollow cylinders assembled from αß-tubulin dimers that form cytoskeletal structures engaged in several functions. MTs are implicated in sensory functions in cilia and flagella and cellular activities that range from cell motility, vesicular traffic, and neuronal processes to cell division in the centrosomes and centrioles. We determined the electrical properties of the MTs with the loose patch clamp technique in either the presence or absence of the MT stabilizer Paclitaxel. We observed electrical oscillations at different holding potentials that responded accordingly in amplitude and polarity. At zero mV in symmetrical ionic conditions, a single MT radiated an electrical power of 10-17 W. The spectral analysis of the time records disclosed a single fundamental peak at 39 Hz in the Paclitaxel-stabilized MTs. However, a richer oscillatory response and two mean conductances were observed in the non-Paclitaxel MTs. The findings evidence that the brain MTs are electrical oscillators that behave as "ionic-based" transistors to generate, propagate, and amplify electrical signals.

Regulation of neural stem cell differentiation and brain development by MGAT5-mediated N-glycosylation.

Undifferentiated neural stem and progenitor cells (NSPCs) encounter extracellular signals that bind plasma membrane proteins and influence differentiation. Membrane proteins are regulated by N-linked glycosylation, making it possible that glycosylation plays a critical role in cell differentiation. We assessed enzymes that control N-glycosylation in NSPCs and found that loss of the enzyme responsible for generating ß1,6-branched N-glycans, N-acetylglucosaminyltransferase V (MGAT5), led to specific changes in NSPC differentiation in vitro and in vivo. Mgat5 homozygous null NSPCs in culture formed more neurons and fewer astrocytes compared with wild-type controls. In the brain cerebral cortex, loss of MGAT5 caused accelerated neuronal differentiation. Rapid neuronal differentiation led to depletion of cells in the NSPC niche, resulting in a shift in cortical neuron layers in Mgat5 null mice. Glycosylation enzyme MGAT5 plays a critical and previously unrecognized role in cell differentiation and early brain development.

Extracellular vesicles from Trypanosoma cruzi-dendritic cell interaction show modulatory properties and confer resistance to lethal infection as a cell-free based therapy strategy.

Extracellular vesicles (EVs) include a heterogeneous group of particles. Microvesicles, apoptotic bodies and exosomes are the most characterized vesicles. They can be distinguished by their size, morphology, origin and molecular composition. To date, increasing studies demonstrate that EVs mediate intercellular communication. EVs reach considerable interest in the scientific community due to their role in diverse processes including antigen-presentation, stimulation of anti-tumoral immune responses, tolerogenic or inflammatory effects. In pathogens, EV shedding is well described in fungi, bacteria, protozoan and helminths parasites. For Trypanosoma cruzi EV liberation and protein composition was previously described. Dendritic cells (DCs), among other cells, are key players promoting the immune response against pathogens and also maintaining self-tolerance. In previous reports we have demonstrate that T. cruzi downregulates DCs immunogenicity in vitro and in vivo. Here we analyze EVs from the in vitro interaction between blood circulating trypomastigotes (Tp) and bone-marrow-derived DCs. We found that Tp incremented the number and the size of EVs in cultures with DCs. EVs displayed some exosome markers and intracellular RNA. Protein analysis demonstrated that the parasite changes the DC protein-EV profile. We observed that EVs from the interaction of Tp-DCs were easily captured by unstimulated-DCs in comparison with EVs from DCs cultured without the parasite, and also modified the activation status of LPS-stimulated DCs. Noteworthy, we found protection in animals treated with EVs-DCs+Tp and challenged with T. cruzi lethal infection. Our goal is to go deep into the molecular characterization of EVs from the DCs-Tp interaction, in order to identify mediators for therapeutic purposes.

Psychological distress and unsatisfied information needs in heart failure patients and ventricular dysfunction without previously diagnosed psychiatric disorder. Cross-sectional study in a national reference center / Distrés psicológico y necesidades de información insatisfechas en pacientes con insuficiencia cardiaca y disfunción ventricular sin trastorno psiquiátrico previamente diagnosticado. Estudio transversal en un centro de referencia nacional.

Introduction: Heart failure (HF) is a chronic disease that acutely and progressively reduces physical functionality. The patient commonly suffers from intermittent relapses that increase the likelihood of comorbidities such as chronic insomnia, cognitive impairment, alterations in sexual response, psychological distress, symptoms of anxiety and depression disorder, and decreased self-care behaviors. The objective of this study was to identify the main needs for psychological support in patients with HF. Methodology: A descriptive, cross-sectional and analytical study was carried out. Participants were selected through consecutive non-probability samples. 150 patients with a diagnosis of HF who attended the Specialized Center for Heart Failure at the National Institute of Cardiology "Ignacio Chávez" were evaluated from November 2018 to April 2019, applying the inventories: Quality of life in patients with HF (Minnesota), Hospital Anxiety and Depression Scale (HADS), psychological distress thermometer (visual analog scale) and the HF Patient Information Needs Inventory. Results: 33% of the patients perceive a high level of psychological distress that requires immediate assistance and 26.6% report a medium level that requires monitoring. The main information needs reported by the patients were information on taking medications (53.7%) and managing psychological distress (43.9%). Conclusion: Active assessment of psychological distress and unmet information needs is relevant in patients with heart failure, thus highlighting the importance of their identification and the correct design and application of evidence-based interventions aimed at their resolution.

Introducción: La insuficiencia cardiaca crónica (ICC) es una enfermedad que reduce de manera aguda y progresiva la funcionalidad física. El paciente comúnmente sufre de recaídas intermitentes que aumentan la probabilidad de comorbilidades como insomnio crónico, deterioro cognitivo, alteraciones en la respuesta sexual, estrés psicológico, síntomas de trastorno de ansiedad y depresión y disminución de las conductas de autocuidado. Objetivo: Identificar las principales necesidades de apoyo psicológico en pacientes con IC. Metodología: Se realizó un estudio descriptivo, transversal y analítico. Se evaluaron 150 pacientes con ICC del Centro Especializado en Insuficiencia Cardiaca del Instituto Nacional de Cardiología Ignacio Chávez de noviembre de 2018 a abril de 2019. Se aplicaron los inventarios: Calidad de vida en pacientes con IC (Minnesota), Escala de Ansiedad y Depresión Hospitalaria (HADS), termómetro del distrés psicológico (escala analógica visual) y el Inventario de Necesidades de Información del Paciente con IC. Resultados: Treinta y tres por ciento de los pacientes perciben un nivel alto de distrés psicológico que requiere asistencia inmediata y el 26.6% reporta un nivel medio que requiere monitoreo. Las principales necesidades de información reportadas por los pacientes fueron información sobre la toma de medicamentos (53.7%) y manejo del estrés psicológico (43.9%). Conclusión: En pacientes con IC es relevante la valoración activa de distrés psicológico y necesidades de información no cubiertas, resaltando de este modo la importancia de su identificación y el correcto diseño y aplicación de intervenciones basadas en la evidencia enfocadas a su resolución.

Reconstructing culture: A latent profile analysis of Mexican-heritage young women's cultural practices, gender values, and ethnic identity.

OBJECTIVE: In the U.S., Mexican culture has been characterized as inherently traditional in its gender values. However, we aimed to highlight the heterogeneity of Mexican culture within the U.S. by testing whether Mexican-heritage women who reject traditional gender values necessarily disavow other cultural connections (i.e., practices, identity). METHOD: Mexican-heritage young women (N = 322; Mage = 20.42) attending a U.S. university completed a survey evaluating their cultural practices, gender values, and ethnic identity. RESULTS: Latent profile analyses revealed five profiles based on cultural practices (either high [immersed] or moderate [participating] levels) and gender values (either traditional, moderate, or nontraditional): (a) immersed/nontraditional, (b) immersed/moderate, (c) immersed/traditional, (d) participating/nontraditional, and (e) participating/moderate. Regardless of gender values, the immersed profiles were generally stronger in Mexican ethnic identity than the participating profiles. CONCLUSIONS: Contrary to some prior views linking Mexican cultural practices with traditional gender values, many Mexican-heritage women rejected traditional gender values while maintaining strong immersion in cultural practices and strong ethnic identities. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Early Immune Response Elicited by Different Trypanosoma cruzi Infective Stages.

Trypanosoma cruzi is a protozoan parasite that affects millions of people in Latin America. Infection occurs by vectorial transmission or by transfusion or transplacental route. Immune events occurring immediately after the parasite entrance are poorly explored. Dendritic cells (DCs) are target for the parasite immune evasion mechanisms. Recently, we have demonstrated that two different populations of DCs display variable activation after interaction with the two infective forms of the parasite: metacyclic or blood trypomastigotes (mTp or bTp) in vitro. The skin constitutes a complex network with several populations of antigen-presenting cells. Previously, we have demonstrated T. cruzi conditioning the repertoire of cells recruited into the site of infection. In the present work, we observed that mTp and bTp inoculation displayed differences in cell recruitment to the site of infection and in the activation status of APCs in draining lymph nodes and spleen during acute infection. Animals inoculated with mTp exhibited 100% of survival with no detectable parasitemia, in contrast with those injected with bTp that displayed high mortality and high parasite load. Animals infected with mTp and challenged with a lethal dose of bTp 15 days after primary infection showed no mortality and incremented DC activation in secondary lymphoid organs compared with controls injected only with bTp or non-infected mice. These animals also displayed a smaller number of amastigote nests in cardiac tissue and more CD8 T cells than mice infected with bTp. All the results suggest that both Tp infective stages induce an unequal immune response since the beginning of the infection.

Honeybee Brain Oscillations Are Generated by Microtubules. The Concept of a Brain Central Oscillator.

Microtubules (MTs) are important structures of the cytoskeleton in neurons. Mammalian brain MTs act as biomolecular transistors that generate highly synchronous electrical oscillations. However, their role in brain function is largely unknown. To gain insight into the MT electrical oscillatory activity of the brain, we turned to the honeybee (Apis mellifera) as a useful model to isolate brains and MTs. The patch clamp technique was applied to MT sheets of purified honeybee brain MTs. High resistance seal patches showed electrical oscillations that linearly depended on the holding potential between ± 200 mV and had an average conductance in the order of ~9 nS. To place these oscillations in the context of the brain, we also explored local field potential (LFP) recordings from the Triton X-permeabilized whole honeybee brain unmasking spontaneous oscillations after but not before tissue permeabilization. Frequency domain spectral analysis of time records indicated at least two major peaks at approximately ~38 Hz and ~93 Hz in both preparations. The present data provide evidence that MT electrical oscillations are a novel signaling mechanism implicated in brain wave activity observed in the insect brain.

Modulatory Effect of Trypanosoma cruzi Infective Stages in Different Dendritic Cell Populations in vitro.

Trypanosoma cruzi is a protozoan parasite that infects at least 7 million persons in the world (OMS, 2019). In endemic areas, infection normally occurs by vectorial transmission; however, outside, it normally happens by blood and includes congenital transmission. The persistence of T. cruzi during infection suggests the presence of immune evasion mechanisms and the modulation of the anti-parasite response to a profile incapable of eradicating the parasite. Dendritic cells (DCs) are a heterogeneous population of antigen-presenting cells (APCs) that patrol tissues with a key role in mediating the interface between the innate and adaptive immune response. Previous results from our lab and other groups have demonstrated that T. cruzi modulates the functional properties of DCs, in vitro and in vivo. During vectorial transmission, metacyclic (m) trypomastigotes (Tps) eliminated along with the insect feces reach the mucous membranes or injured skin. When transmission occurs by the hematic route, the parasite stage involved in the infection is the circulating or blood (b) Tp. Here, we studied in vitro the effect of both infective mTp and bTp in two different populations of DCs, bone marrow-derived DCs (BMDCs) and XS106, a cell line derived from epidermal DCs. Results demonstrated that the interaction of both Tps imparts a different effect in the functionality of these two populations of DCs, suggesting that the stage of T. cruzi and DC maturation status could define the immune response from the beginning of the ingress of the parasite, conditioning the course of the infection.

Actin filaments modulate electrical activity of brain microtubule protein two-dimensional sheets.

The cytoskeleton of eukaryotic cells contains networks of actin filaments and microtubules (MTs) that are jointly implicated in various cell functions, including cell division, morphogenesis, and migration. In neurons, this synergistic activity drives both the formation of axons during development and synaptic activity in mature neurons. Both actin filaments and MTs also are highly charged polyelectrolytes that generate and conduct electrical signals. However, no information is presently available on a potential electrical crosstalk between these two cytoskeletal networks. Herein we tested the effect of actin polymerization on the electrical oscillations generated by two-dimensional sheets of bovine brain microtubule protein (2D-MT). The voltage-clamped 2D-MT sheets displayed spontaneous electrical oscillations representing a synchronous 224% change in conductance, and a fundamental frequency of 38 Hz. At 60 mV, a 4.15 nC of integrated charge transferred per second increased by 72.3% (7.15 nC) after addition of monomeric (G)-actin. This phenomenon had a 2-min lag time, and was prevented by the presence of the G-actin-binding protein DNAse I. Addition of prepolymerized F-actin, however, had a rapid onset (<10 s) and a higher effect on the tubulin sheets (~100% increase, 8.25 nC). The data are consistent with an interaction between the actin cytoskeleton and tubulin structures, in what seems to be an electrostatic effect. Because actin filaments and MTs interact with each other in neurons, it is possible for this phenomenon to be present, and of relevance in the processing of intracellular signaling, including the gating and activation of actin cytoskeleton-regulated excitable ion channels in neurons.

Cal MediConnect Enrollment: Why Are Dual-Eligible Consumers in Los Angeles County Opting Out?

Los Angeles County has the state's lowest rate of consumer enrollment in Cal MediConnect, a program that is responsible for the delivery and coordination of medical, behavioral health, and long-term services and support benefits for individuals who are dually eligible for Medicare and Medi-Cal. This policy brief examines the factors that influence consumer decisions and may contribute to low enrollment rates. Influential factors include consumer knowledge of health care options, perception of choice, and disruption of existing care. Differences in decision making by age, complexity of health care needs, race/ethnicity, immigration status, and primary language are also noted. Policy recommendations include engaging consumers in the planning and dissemination of information about their health care options, optimizing consumer choice and implementing the least disruptive pathway to enrollment, and recognizing and responding to the great diversity of dual-eligible consumers in Los Angeles County.

Reagentless, Structure-Switching, Electrochemical Aptamer-Based Sensors.

The development of structure-switching, electrochemical, aptamer-based sensors over the past ∼10 years has led to a variety of reagentless sensors capable of analytical detection in a range of sample matrices. The crux of this methodology is the coupling of target-induced conformation changes of a redox-labeled aptamer with electrochemical detection of the resulting altered charge transfer rate between the redox molecule and electrode surface. Using aptamer recognition expands the highly sensitive detection ability of electrochemistry to a range of previously inaccessible analytes. In this review, we focus on the methods of sensor fabrication and how sensor signaling is affected by fabrication parameters. We then discuss recent studies addressing the fundamentals of sensor signaling as well as quantitative characterization of the analytical performance of electrochemical aptamer-based sensors. Although the limits of detection of reported electrochemical aptamer-based sensors do not often reach that of gold-standard methods such as enzyme-linked immunosorbent assays, the operational convenience of the sensor platform enables exciting analytical applications that we address. Using illustrative examples, we highlight recent advances in the field that impact important areas of analytical chemistry. Finally, we discuss the challenges and prospects for this class of sensors.

Isolation and immobilization of influenza virus-specific N-SA-α-2,3-Gal receptors using magnetic nanoparticles coated with chitosan and Maackia amurensis lectin.

Avian influenza viruses preferentially bind to sialic acid alpha-2,3-galactose (N-SA-α-2,3-Gal) receptors on epithelial cells. Herein, we describe a procedure we have developed for isolation of N-SA-α-2,3-Gal receptors from porcine trachea using magnetic nanoparticles (NPs) coated with chitosan (NP-Ch) and functionalized with Maackia amurensis lectin (NP-lectin). Magnetic nanoparticles were coated with chitosan in a one-step co-precipitation, and then M. amurensis lectin was immobilized covalently using glutaraldehyde. Lectin coated nanoparticles were incubated with sialic acid enriched fraction of tracheal homogenate, and N-SA-α-2,3-Gal receptor was extracted under magnetic field in two cycles. The presence of 66.4 kDa protein was determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The interaction of immobilized receptor (NP-Ch-R) with M. amurensis lectin (NP-Ch-R-L) was demonstrated by Fourier transform infrared spectrometry (FTIR) and thermogravimetric analysis (TGA).

Prediabetes, diabetes, and risk of breast cancer: a case-control study.

BACKGROUND AND AIMS: Although underlying mechanisms have been described to account for the association between prediabetes and diabetes with breast cancer, reported results have been inconsistent. We undertook this study to determine whether prediabetes and diabetes are risk factors for breast cancer in Mexican women with no family history of breast cancer in the mother, daughters, or sisters. METHODS: A case-control study was carried out during 2011-2013. "Case" referred to patients with a histopathological diagnosis of breast cancer (incident and primary cases) (n = 240); "controls" were those with a BI-RADS 1 or 2 mammography result (n = 406). Categorization of prediabetes and diabetes was based on self-reporting or fasting glucose and glycated hemoglobin blood sampling results. Reproductive and sociodemographic data were collected by interview. Odds ratios (ORs) and 95% confidence intervals (CI) were calculated using multivariate unconditional binary logistic regression analysis. RESULTS: Prediabetes increased the risk of breast cancer in postmenopausal women (adjusted OR 2.08, 95% CI 1.10-3.96) as did diabetes (adjusted OR 2.85, 95% CI 1.55-5.26). A history of diabetes preceding breast cancer by ≥7 years and <7 years were both associated with an increased risk for breast cancer (adjusted OR 2.80, 95% CI 1.40-5.60 and 3.00, 95% CI 1.50-5.90, respectively). CONCLUSIONS: This is the first study in Mexico evaluating prediabetes and diabetes as breast cancer risk factors in women with no first-degree relatives with breast cancer. Our findings suggest that women with prediabetes and diabetes should be considered a more vulnerable population for early breast cancer detection.

Preparation of functionalized porous nano-γ-Al2O3 powders employing colophony extract.

This study reports the synthesis of porous nano alumina employing carboxylato-alumoxanes [Al(O) x (OH) y (O2CR) z ] n as precursors for controlling the pore size, pore size distribution and porosity of the alumina, using a new process ecofriendly. The carboxylato-alumoxanes was prepared by the reaction of boehmite with carboxylic acids. The boehmite was obtained by the hydrolysis of aluminum alkoxide in an aqueous solution. The colophony extract is employed as a source of carboxylic acids. The materials were characterized, using XRD, TGA, N2 physical adsorption, SEM, TEM, NMR and FTIR. A mechanism was proposed for the formation of the synthesized structures. TEM measurements confirmed particle size ranged from 5 to 8 nm.

Effects of estradiol and progesterone on gastric mucosal response to early Helicobacter pylori infection in female gerbils.

BACKGROUND: Gender differences have been shown regarding the changes in the inflammatory response, gastrin secretion, and gastric acidity during Helicobacter pylori infection. AIM: To investigate the role of estradiol and progesterone in the changes of the gastric mucosa induced by H. pylori during the early stage of infection in female gerbils. MATERIALS AND METHODS: Thirty-three adult ovariectomized female gerbils were infected with H. pylori (SS1); 7 days after infection they were treated with low and high doses of estradiol (50 and 250 microg/60 days pellet), progesterone (15 and 50 mg/60 days pellet) and vehicle. Non-ovariectomized infected gerbils were used as control. Gerbils were euthanized after 6 weeks of infection. Histologic evaluation, immunohistochemical detection of proliferation cell nuclear antigen (PCNA), gastrin, and apoptosis by terminal deoxynucleotide nick end labeling (TUNEL) assay were performed. Positive cells for PCNA, TUNEL, and gastrin were counted in 10 oriented glands per animal. Two-sided p = .05 was considered significant. RESULTS: Estradiol-treated groups showed more intense and extended acute and follicular gastritis compared to the vehicle group, whereas progesterone-treated groups presented less gastritis than the other groups. Proliferation and apoptosis indexes were significantly lower in the vehicle group when compared with those of the control; both indexes were increased in the high-dose estradiol and progesterone groups as compared with those of the vehicle. Grade I nonmetaplastic atrophy was observed in the vehicle and progesterone groups. The high-dose progesterone group showed a significant reduction in the number of gastrin cells. CONCLUSIONS: Estradiol and progesterone participate in the gastric mucosal response to early H. pylori infection in gerbils.

Compulsão à repetição: uma abordagem do conceito na sua relação com a transferência em Freud e Lacan

O trabalho aborda o desenvolvimento do conceito de compulsão à repetição, mostrando que, para sua conceituação, a transferência foi um elemento indispensável. Partindo da confluência entre os fenômenos e sublinhando a intervenção lacaniana que lhes restituiu sua justa dimensão como conceitos, percorre os desdobramentos do problema da repetição equacionados nos limites do princípio de prazer, mostrando como transferência e repetição apareciam constantemente entrelaçadas na obra freudiana. A partir da correlação necessária entre o sujeito do inconsciente e a linguagem, introduzida por Lacan, aponta-se a gênese do conceito de repetição como real que emerge do simbólico - impossível referido a um além do princípio de prazer que só pode ser contornado pela pulsão. Discute-se ainda o papel do analista neste circuito pulsional no qual ele é inserido e as repercussões que tal inserção traz para a prática psicanalítica (AU)

Síndrome de Guillain-Barré: generalidades y manejo / Guillain-Barre Syndrome: generalities and management

El Síndrome de Guillain-Barré es una polirradiculoneuropatía inflamatoria que ocupa el primer lugar comocausa de parálisis fláccida aguda generalizada, ahora que la Poliomelitis ha sido virtualmente eliminada. Este síndrome se presenta como una emergencia neurológica que a pesar de no contar con ningún signo o síntoma patognomónicos presenta una serie de hallazgos clínicos y electrofisiológicos que permiten un rápido reconocimiento, facilitando así su manejo, sin el cual la morbilidad y mortalidad pueden llegar a ser muy altas. En Costa Rica tiene una incidencia anual aproximada de 1.7/100000 habitantes, con una mortalidad en el Hospital San Juan de Dios de 10.34 por ciento en los últimos 4 años. Se presenta una revisión de la literatura con énfasis en los criterios diagnósticos y estudios confirmatorios especialmente los electrofisiológicos, correlacionando algunos datos de incidencia a nivel nacional y recomendaciones de su manejo, incluyendo las indicaciones de nuevas terapias como la Plasmaféresis y Camoglobulina intravenosa