Iron chelation mitigates mitochondrial dysfunction and oxidative stress by enhancing nrf2-mediated antioxidant responses in the renal cortex of a murine model of type 2 diabetes.

Renal iron overload is a common complication of diabetes that leads to oxidative stress and mitochondrial dysfunction in the kidneys. This study investigated the effects of iron chelation using deferiprone on mitochondrial dysfunction and oxidative stress in the renal cortex of a murine model of type 2 diabetes. Diabetic rats were treated with deferiprone (50 mg/kg BW) for 16 weeks. Our results show that iron chelation with deferiprone significantly increased the nuclear accumulation of Nrf2, a transcription factor that regulates the expression of antioxidant enzymes. This led to enhanced antioxidant capacity, reduced production of reactive oxygen species, and improved mitochondrial bioenergetic function in diabetic rats. However, chronic iron chelation led to altered mitochondrial respiration and increased oxidative stress in non-diabetic rats. In conclusion, our findings suggest that iron chelation with deferiprone protects mitochondrial bioenergetics and mitigates oxidative stress in the renal cortex, involving the NRF2 pathway in type 2 diabetes.

Tandem-repeat lectins: structural and functional insights.

Multivalency in lectins plays a pivotal role in influencing glycan cross-linking, thereby affecting lectin functionality. This multivalency can be achieved through oligomerization, the presence of tandemly repeated carbohydrate recognition domains, or a combination of both. Unlike lectins that rely on multiple factors for the oligomerization of identical monomers, tandem-repeat lectins inherently possess multivalency, independent of this complex process. The repeat domains, although not identical, display slightly distinct specificities within a predetermined geometry, enhancing specificity, affinity, avidity and even oligomerization. Despite the recognition of this structural characteristic in recently discovered lectins by numerous studies, a unified criterion to define tandem-repeat lectins is still necessary. We suggest defining them multivalent lectins with intrachain tandem repeats corresponding to carbohydrate recognition domains, independent of oligomerization. This systematic review examines the folding and phyletic diversity of tandem-repeat lectins and refers to relevant literature. Our study categorizes all lectins with tandemly repeated carbohydrate recognition domains into nine distinct folding classes associated with specific biological functions. Our findings provide a comprehensive description and analysis of tandem-repeat lectins in terms of their functions and structural features. Our exploration of phyletic and functional diversity has revealed previously undocumented tandem-repeat lectins. We propose research directions aimed at enhancing our understanding of the origins of tandem-repeat lectin and fostering the development of medical and biotechnological applications, notably in the design of artificial sugars and neolectins.

Structural and evolutionary insights into the multidomain galectin from the red abalone Haliotis rufescens with specificity for sulfated glycans.

Galectins are an evolutionarily ancient family of lectins characterized by their affinity for ß-galactosides and a conserved binding site in the carbohydrate recognition domain (CRD). These lectins are involved in multiple physiological functions, including the recognition of glycans on the surface of viruses and bacteria. This feature supports their role in innate immune responses in marine mollusks. Here, we identified and characterized a galectin, from the mollusk Haliotis rufescens (named HrGal), with four CRDs that belong to the tandem-repeat type. HrGal was purified by affinity chromatography in a galactose-agarose resin and exhibited a molecular mass of 64.11 kDa determined by MALDI-TOF mass spectrometry. The identity of HrGal was verified by sequencing, confirming that it is a 555 amino acid protein with a mass of 63.86 kDa. This protein corresponds to a galectin reported in GenBank with accession number AHX26603. HrGal is stable in the presence of urea, reducing agents, and ions such as Cu2+ and Zn2+. The recombinant galectin (rHrGal) was purified from inclusion bodies in the presence of these ions. A theoretical model obtained with the AlphaFold server exhibits four non-identical CRDs, with a ß sandwich folding and the representative motifs for binding ß-galactosides. This allows us to classify HrGal within the tandem repeat galectin family. On the basis of a phylogenetic analysis, we found that the mollusk sequences form a monophyletic group of tetradomain galectins unrelated to vertebrate galectins. HrGal showed specificity for galactosides and glucosides but only the sulfated sugars heparin and ι-carrageenan inhibited its hemagglutinating activity with a minimum inhibitory concentration of 4 mM and 6.25 X 10-5% respectively. The position of the sulfate groups seemed crucial for binding, both by carrageenans and heparin.

Exploring the druggability of the binding site of aurovertin, an exogenous allosteric inhibitor of FOF1-ATP synthase.

In addition to playing a central role in the mitochondria as the main producer of ATP, FOF1-ATP synthase performs diverse key regulatory functions in the cell membrane. Its malfunction has been linked to a growing number of human diseases, including hypertension, atherosclerosis, cancer, and some neurodegenerative, autoimmune, and aging diseases. Furthermore, inhibition of this enzyme jeopardizes the survival of several bacterial pathogens of public health concern. Therefore, FOF1-ATP synthase has emerged as a novel drug target both to treat human diseases and to combat antibiotic resistance. In this work, we carried out a computational characterization of the binding sites of the fungal antibiotic aurovertin in the bovine F1 subcomplex, which shares a large identity with the human enzyme. Molecular dynamics simulations showed that although the binding sites can be described as preformed, the inhibitor hinders inter-subunit communications and exerts long-range effects on the dynamics of the catalytic site residues. End-point binding free energy calculations revealed hot spot residues for aurovertin recognition. These residues were also relevant to stabilize solvent sites determined from mixed-solvent molecular dynamics, which mimic the interaction between aurovertin and the enzyme, and could be used as pharmacophore constraints in virtual screening campaigns. To explore the possibility of finding species-specific inhibitors targeting the aurovertin binding site, we performed free energy calculations for two bacterial enzymes with experimentally solved 3D structures. Finally, an analysis of bacterial sequences was carried out to determine conservation of the aurovertin binding site. Taken together, our results constitute a first step in paving the way for structure-based development of new allosteric drugs targeting FOF1-ATP synthase sites of exogenous inhibitors.

Equivalencia translingüística y consistencia interna del Rapid Estimate Adult Literacy in Dentistry 99 (REALD-99) en población mexicana / Transliguistic Equivalence and Internal Consistency of the Rapid Estimate Adult Literacy in Dentistry 99 (REALD-99) applied to Mexican Population

Objetivo: Determinar la equivalencia lingüística al español y la consistencia interna del Rapid Estimate of Adult Literacy in Dentistry 99 (REALD-99) en población mexicana. Métodos: la equivalencia del REALD-99 se hizo mediante la metodología traducción-retraducción por expertos en la traducción de la lengua inglesa y se validó su contenido por parte de cinco odontólogos generales. El instrumento se aplicó a una muestra de 995 personas de 15 a 54 años que solicitaron atención odontológica por primera vez. La participación de los individuos fue voluntaria y el consentimiento se hizo por escrito. Se analizaron variables epidemiológicas y se determinó la consistencia interna del instrumento con la prueba del Alfa de Cronbach. Resultados: se identificaron dos palabras con traducción idéntica y tres sin aplicación en el contexto odontológico local. La edad promedio de los participantes fue de 30 años (DE ±11); el 62 % fueron mujeres. La aplicación del instrumento tuvo un promedio de 87 aciertos (DE ±9.2) con un tiempo promedio de aplicación de 2.24 minutos. El alfa de Cronbach fue de 0.91 con las 99 palabras. Conclusiones: el instrumento es intercambiable y equivalente con una consistencia interna similar al obtenido en otros países; sin embargo, los resultados son una aproximación a la habilidad de lectura, pues no garantiza la comprensión, conocimiento y la operatividad de todas las palabras; además, no explica las complejas habilidades involucradas en la alfabetización en salud.

Objective: To determine the linguistic equivalence in the Spanish language and the internal consistency of the Rapid Estimate of Adult Literacy in Dentistry 99 (REALD-99) applied to a sample group of Mexican people. Method: The equivalence of the REALD-99 was performed by expert translators of the English language by means of translation-retranslation; its content was validated by fve bachelors of dentistry. The instrument was applied to a sample group of 995 people between 15 and 54 years old who requested dental care for the frst time. The people participated voluntarily, and their consent was given in writing. Epidemiological variables were analyzed, and the internal consistency of the instrument was determined with the Cronbach's Alpha test. Results: Two words with identical translation and three without application in the local dental context were identifed. The average age of the participants was 30 years old (SD ±11); 62% were women. The application of the instrument was 87 correct answers (SD ±9.2) on average and the application time was a median of 2.24 minutes. Cronbach's alpha was 0.91 with the 99 words. Conclusions: The instrument is interchangeable and equivalent with an internal consistency similar to that obtained in other countries. However, the results are an approximation to the reading ability and do not guarantee the knowledge, comprehension, or operability of related vocabulary and neither they explain the complex skills involved in health literacy.

Antilipidemic and Hepatoprotective Effects of Ethanol Extract of Justicia spicigera in Streptozotocin Diabetic Rats.

Oxidative stress is a factor that contributes to the development of complications in diabetes; however, its effects can be counteracted using exogenous antioxidants that are found in some plants, which is why people turn to traditional medicines in the search for therapeutic treatment. Justicia spicigera has been demonstrated to have the capacity to reduce glycemic levels; however, its effects on non-insulin-dependent organs such as the liver have not been reported. During 30 days of administration of Justicia spicigera ethanol extract, the blood glucose and weight of rats were measured every 5 days. Once the treatment was concluded, the rats were sacrificed. Corporal weight, blood glucose, cholesterol, very-low-density lipoprotein (VLDL), triglycerides, total lipids, and liver profile were reduced in the diabetic condition and normalized with the application of ethanol extract from J. spicigera (EJS). Additionally, there was a significant increase in catalase and superoxide dismutase activity in the control diabetic rats, a decrease in their activity with the extract administration, and no effect on normoglycemic rats. In conclusion, EJS is considered to be capable of reducing oxidative stress by maintaining diminished lipid and liver function profiles in male Wistar rats with streptozotocin-induced diabetes.

Glutathione Participation in the Prevention of Cardiovascular Diseases.

Cardiovascular diseases (CVD) (such as occlusion of the coronary arteries, hypertensive heart diseases and strokes) are diseases that generate thousands of patients with a high mortality rate worldwide. Many of these cardiovascular pathologies, during their development, generate a state of oxidative stress that leads to a deterioration in the patient's conditions associated with the generation of reactive oxygen species (ROS) and reactive nitrogen species (RNS). Within these reactive species we find superoxide anion (O2•-), hydroxyl radical (•OH), nitric oxide (NO•), as well as other species of non-free radicals such as hydrogen peroxide (H2O2), hypochlorous acid (HClO) and peroxynitrite (ONOO-). A molecule that actively participates in counteracting the oxidizing effect of reactive species is reduced glutathione (GSH), a tripeptide that is present in all tissues and that its synthesis and/or regeneration is very important to be able to respond to the increase in oxidizing agents. In this review, we will address the role of glutathione, its synthesis in both the heart and the liver, and its importance in preventing or reducing deleterious ROS effects in cardiovascular diseases.

Micropropagación de Calibanus hookeri (lem.) trel (1911). Una especie amenazada / Micropropagation of Calibanus hookeri (lem.) trel (1911). A threatened species

RESUMEN La especie Calibanus hookerii perteneciente a la familia Asparagaceae, está registrada en la NOM-059-SEMARNAT-2010 catalogada como planta amenazada. Sus poblaciones naturales se han visto reducidas de manera importante debido a una explotación excesiva y destrucción de su hábitat, por lo que se requiere de métodos de propagación eficaz que aseguren su conservación. La propagación in vitro es una alternativa viable para especies vegetales amenazadas. En la presente investigación se reporta el protocolo para la micropropagación de Calibanus hookerii mediante la germinación de semilla sin testa inoculada en medio MS complementado con 2.5, 5.0 y 7.0 mg L-1 de 6 benciladenina (BA), cinetina (K), 2-isopentil-adenina (2iP) y tidiazuron (TDZ). Las variables a medir fueron porcentaje de germinación, número y longitud de brotes producidos por semilla. El tratamiento más eficiente fue de 5.0 mg L-1 de BA produciéndose un promedio de 26 brotes por semilla; el tratamiento menos eficaz fue con 2.5 mg L-1 K en el cual solamente se obtuvieron dos brotes por semilla. De las tres concentraciones de 2iP solamente en la concentración de 7 mg. L-1 mostró resultados produciendo 6 brotes por semilla. En lo que respecta a la longitud del brote ningún tratamiento superó al testigo (8.07cm). La eficiencia la germinación in vitro fue de 56-97%.

ABSTRACT The species Calibanus hookerii belonging to the family Aspagaceae is registered in the NOM-059-SEMARNAT-2010 cataloged in danger of extinction and therefore is necessary of propagation methods that assure its conservation and its propagation. In vitro propagation is a viable alternative for endangered plant species. The present investigation reports the protocol for the micropropagation of Calibanus hookerii. This was achieved by seed germination without test in MS medium supplemented with 2.5, 5.0 and 7.0 mg L-1 of 6-benzyladenine (BA), kinetin (K), 2-isopentyl-adenine (2iP) and tidiazuron (TDZ). The variables to be measured were percentage of germination, number and length of shoots produced by seed. The most efficient treatment was 5 mg L-1 of BA producing an average of 26 shoots per seed, the worst treatment was with 2.5 K only produced 2 shoots per seed, of the four cytokinins used 2ip treatment in only one study of the Performed showed results (7 mg L-1) producing 6 shoots per seed. Regarding the length of the shoot, no treatment exceeded the control (8.07cm). Finally, in vitro germination was high (56-97%) in all treatments.

Identification of a unique endoplasmic retention motif in the Xenopus GIRK5 channel and its contribution to oocyte maturation.

G protein-activated inward-rectifying potassium (K+ ) channels (Kir3/GIRK) participate in cell excitability. The GIRK5 channel is present in Xenopus laevis oocytes. In an attempt to investigate the physiological role of GIRK5, we identified a noncanonical di-arginine endoplasmic reticulum (ER) retention motif (KRXY). This retention motif is located at the N-terminal region of GIRK5, coded by two small exons found only in X. laevis and X. tropicalis. These novel exons are expressed through use of an alternative transcription start site. Mutations in the sequence KRXY produced functional channels and induced progesterone-independent oocyte meiotic progression. The chimeric proteins enhanced green fluorescent protein (EGFP)-GIRK5-WT and the EGFP-GIRK5K13AR14A double mutant, were localized to the ER and the plasma membrane of the vegetal pole of the oocyte, respectively. Silencing of GIRK5 or blocking of this channel by external barium prevented progesterone-induced meiotic progression. The endogenous level of GIRK5 protein decreased through oocyte stages in prophase I augmenting by progesterone. In conclusion, we have identified a unique mechanism by which the expression pattern of a K+ channel evolved to control Xenopus oocyte maturation.

Aquaporin 8 is involved in H2 O2 -mediated differential regulation of metabolic signaling by α1 - and ß-adrenoceptors in hepatocytes.

Reactive oxygen species participate in regulating intracellular signaling pathways. Herein, we investigated the reported opposite effects of hydrogen peroxide (H2 O2 ) on metabolic signaling mediated by activated α1 - and ß-adrenoceptors (ARs) in hepatocytes. In isolated rat hepatocytes, stimulation of α1 -AR increases H2 O2 production via NADPH oxidase 2 (NOX2) activation. We find that the H2 O2 thus produced is essential for α1 -AR-mediated activation of the classical hepatic glycogenolytic, gluconeogenic, and ureagenic responses. However, H2 O2 inhibits ß-AR-mediated activation of these metabolic responses. We show that H2 O2 mediates its effects on α1 -AR and ß-AR by permeating cells through aquaporin 8 (AQP8) channels and promoting Ca2+ mobilization. Thus, our findings reveal a novel NOX2-H2 O2 -AQP8-Ca2+ signaling cascade acting downstream of α1 -AR in hepatocytes, which, by negatively regulating ß-AR signaling, establishes negative crosstalk between the two pathways.

Correction to: Low-cost HPV testing and the prevalence of cervical infection in asymptomatic populations in Guatemala.

Following publication of the original article [1], an error was reported in the tagging of Joël Fokom Domgue in the author group. The tagging in this correction article has been fixed.

"Funny" channels in cardiac mitochondria modulate membrane potential and oxygen consumption.

The hyperpolarization-activated cyclic nucleotide-gated (HCN) channels are encoded by a family of four genes (HCN1-4). All isoforms are expressed in the heart, HCN4 being the most abundant in the sinoatrial node (SAN). HCN channels are responsible for the "funny" current (If) associated with the generation and autonomic control of the diastolic depolarization phase of cardiac action potential. In this work we performed a proteomic analysis of HCN4 transfected in HEK293 cells. Most of the identified proteins in the HCN4 network belonged to mitochondria. The subcellular localization of HCN channels was predicted in plasma membrane, mitochondria and nucleus. Experimentally, HCN2 (full-length, truncated), HCN3 (full-length, truncated) and HCN4 (truncated) were detected in rat heart mitochondria by immunoblotting. If sensitive to ZD7288, was recorded by patch-clamp in mitoplasts from cardiomyocytes. Mitochondrial membrane potential (ΔΨm) assessment in H9c2 cells revealed that ZD7288 induced almost 50% higher hyperpolarization respect to control at 30 min. Furthermore, ZD7288 reduced oxygen consumption attributed to ATP synthesis in H9c2 cells. In conclusion, we identify for the first time functional HCN channels in mammalian cardiac mitochondria and demonstrate their impact on ΔΨm and respiration.

SDHD gene mutation in Mexican population with carotid body tumor.

INTRODUCTION: Among the U.S. population, the p81L SDHD (11q23) gene mutation is present in 6-36% of patients with sporadic carotid body tumor (CBT), but in familial cases is high as 80%. That is why the P81L mutation is used as a screening method for carotid body tumor in the U.S. METHODS: We included 25 patients who underwent resection of a CBT from January 2010 to June 2015. After informed consent, a blood sample was taken for genetic testing on real-time polymerase chain reaction, in order to identify p81L mutation in the SDHD gene. The information was analyzed with descriptive statistics, using central tendency and description measures. RESULTS: In our group, 92% were females, a mean age of 55.5 years, and 52% were Shamblin type II. The most common place of residence was Mexico City, 8% of the patients had family history, about 20% of the patients had a contralateral tumor and 16% had antecedent of another kind of tumor, 4 (16%) p81L SDHD gene mutations were detected, all of them were heterozygous. CONCLUSIONS: The p81L mutation in the SDHD gene was found in the Mexican population in higher grade that in the U.S. population, which explain the high incidence of this pathology in our country, but we need more studies about this subject.

INTRODUCCIÓN: La mutación p81L del gen SDHD (11q23) se encuentra presente en el 6-36% de los pacientes con tumores del cuerpo carotídeo (TCC) esporádicos y hasta en el 80% de los que presentan TCC familiares. En los EE.UU. se usa como método de cribado para TCC. MÉTODO: Se incluyeron 25 pacientes consecutivos operados de resección de TCC entre enero de 2010 y junio de 2015. Se les tomó muestra sanguínea venosa que se sometió a reacción en cadena de la polimerasa en tiempo real para identificar la mutación p81L del gen SDHD (11q23). La información se analizó con estadística descriptiva mediante medidas de tendencia central y dispersión. RESULTADOS: Del grupo en estudio, el 92% eran mujeres, la edad promedio era de 55.5 años y el 52% tenían tumor Shamblin tipo II. El lugar de residencia más frecuente fue la Ciudad de México. El 8% presentaban antecedentes familiares, el 20% tumor bilateral y el 16% presentaron un tumor en otra región. Se encontró la mutación p81L del gen SDHD (11q23) en el 16% de los pacientes de forma heterocigota. CONCLUSIONES: La mutación p81L del gen SDHD se encuentra presente en la población mexicana en un grado más elevado que lo reportado en los EE.UU., lo que podría explicar la alta incidencia en nuestro medio.

Aldehyde dehydrogenase diversity in bacteria of the Pseudomonas genus.

Aldehyde dehydrogenases (ALDHs) comprise one of the most ancient protein superfamilies widely distributed in the three domains of life. Their members have been extensively studied in animals and plants, sorted out in different ALDH protein families and their participation in a broad variety of metabolic pathways has been documented. Paradoxically, no systematic studies comprising ALDHs from bacteria have been performed so far. Among bacteria, the genus Pseudomonas occupies numerous ecological niches, and is one of the most complex bacterial genera with the largest number of known species. For these reasons, we selected Pseudomonas as a paradigm to analyze the diversity of ALDHs in bacteria. With this aim, complete Pseudomonas genome sequences and annotations were retrieved from NCBI's RefSeq genome database. The 258 Pseudomonas strains belong to 46 different species, along with 23 with no species designation. The genomes of these Pseudomonas contain from 3,315 to 6,825 annotated protein coding genes. A total of 6,510 ALDH sequences were found in the selected Pseudomonas, with a median of 24 ALDH-coding genes per strain (by comparison humans possess only 19 different ALDH loci). Pseudomonas saudiphocaensis possesses the lowest number of aldh genes (9), while Pseudomonas pseudoalcaligenes KF707 NBRC110670 possesses the maximum number of aldh genes (49). The ALDHs found in Pseudomonas can be sorted out into 42 protein families, with a predominance of 14 families, which contained 76% of all ALDHs found. In this regard, it is important to note that many Pseudomonas genomes have multiple aldh genes coding for proteins belonging to the same family. Given that all strains contained members of families ALDH4, ALDH5, ALDH6, ALDH14, ALDH18 and ALDH27, we consider these families to be part of the core Pseudomonas genome.

Actitudes y prácticas ante la búsqueda de atención odontológica en personas de la ciudad de México. Estudio cualitativo / Attitudes and practices toward dental health care searching among people of méxico city. qualitative study / Atitudes e práticas na busca por atendimento odontológico entre pessoas da Cidade do México. Estudo qualitativo

Antecedentes: La salud bucal es afectada por caries y enfermedad periodontal; ambas progresivas, irreversibles y cuyos efectos son acumulables con el tiempo. Sin embargo, son evitables cuando existen medidas preventivas y se busca la atención oportuna. Objetivo: Identificar las actitudes y prácticas que tienen las personas ante la búsqueda de atención odontológica. Métodos: Estudio cualitativo que identificó desde la subjetividad de los participantes, la experiencia y significado de la prevención y atención odontológicas; efectuado en 7 grupos focales con personas entre 18 y 60 años de edad. La muestra se definió por saturación teórica. Se diseñó y aplicó una guía semiestructurada para indagar sobre: Alternativas empleadas, búsqueda de atención, uso de los sistemas de salud y, experiencia de atención y salud bucal. Resultados: Se identificaron elementos que denotan ausencia de prevención. El dolor es referido como la principal manifestación de un problema y si éste es controlado, la búsqueda de atención se detiene. El sangrado de encía no es considerado relevante. Los procedimientos alternativos empleados antes de solicitar atención profesional son: automedicación, remedios caseros, consulta a empleados de farmacia y la internet. La búsqueda de atención se detuvo por: falta de tiempo y dinero, experiencias negativas previas (miedo, ansiedad), apatía, desidia y la pobre calidad de atención percibida en los servicios de salud. Conclusión: La falta de prevención está determinada por factores relacionados con el individuo y con el sistema de salud. La búsqueda de atención se hace con fines curativos o para reducir el daño resultante de consecuencias complejas y costosas en el tratamiento.

Background: Oral health is affected by caries and periodontal disease; both are progressive and irreversible, and the effects are cumulative with the passing of time. However, such effects are avoidable when preventive measures are taken along with timely care. Purpose: To identify the variables related to the absence of prevention and delay of dental care. Methods: Qualitative study conducted on seven focal groups of people between 18 and 60 years of age, to identify the experience and meaning of prevention and dental care. The sample was defined by theoretical saturation. A semi-structured guide was designed and applied to inquire about: options used, seeking care, use of health systems, and experience in the oral health care. Results: Absence of prevention was identified: feeling pain is the primary symptom of a problem; but if it is controlled, the search for care stops. Gingival bleeding is not considered as relevant. The alternative procedures used before requesting professional attention are self-medication, home remedies, consultation with pharmacy employees, or the internet. In such cases the search for dental care stopped by lack of time and money, negative experiences (fear or anxiety), apathy, indifference, and a poor-quality perception of health services. Conclusion: Lack of prevention is determined by factors related to the individual and the health system. A subsequent search for care with therapeutic purposes or damage limitation entails complex and costly consequences in treatments.

Antecedentes: A saúde bucal é afetada por cáries e doença periodontal; ambos são progressivos e irreversíveis, e os efeitos são cumulativos com o passar do tempo. No entanto, tais efeitos são evitáveis quando medidas preventivas são tomadas junto com o atendimento oportuno. Objetivo: Identificar as variáveis relacionadas à ausência de prevenção e demora no atendimento odontológico. Métodos: Estudo qualitativo, realizado em sete grupos focais de pessoas entre 18 e 60 anos, para identificar a experiência e o significado da prevenção e tratamento odontológico. A amostra foi definida por saturação teórica. Um roteiro semiestruturado foi elaborado e aplicado para indagar sobre: opções utilizadas, busca de assistência, uso de sistemas de saúde e experiência na atenção à saúde bucal. Resultados: Ausência de prevenção foi identificada: sentir dor é o principal sintoma de um problema; mas se for controlada, a busca por cuidados pára. O sangramento gengival não é considerado relevante. Os procedimentos alternativos utilizados antes de solicitar atenção profissional são: automedicação, remédios caseiros, consulta a funcionários de farmácia ou internet. Nesses casos, a busca por atendimento odontológico foi interrompida por falta de tempo e dinheiro, experiências negativas (medo ou ansiedade), apatia, indiferença e percepção de baixa qualidade dos serviços de saúde. Conclusão: A falta de prevenção é determinada por fatores relacionados ao indivíduo e ao sistema de saúde. Uma busca subsequente de cuidados com fins terapêuticos ou limitação de danos acarreta conseqüências complexas e onerosas nos tratamentos.

Bona fide choline monoxygenases evolved in Amaranthaceae plants from oxygenases of unknown function: Evidence from phylogenetics, homology modeling and docking studies.

Few land plants can synthesize and accumulate the osmoprotectant glycine betaine (GB) even though this metabolic trait has major adaptive importance given the prevalence of drought, hypersaline soils or cold. GB is synthesized from choline in two reactions catalyzed by choline monooxygenases (CMOs) and enzymes of the family 10 of aldehyde dehydrogenases (ALDH10s) that gained betaine aldehyde dehydrogenase activity (BADH). Homolog genes encoding CMO and ALDH10 enzymes are present in all known land plant genomes, but since GB-non-accumulators plants lack the BADH-type ALDH10 isozyme, they would be expected to also lack the CMO activity to avoid accumulation of the toxic betaine aldehyde. To explore CMOs substrate specificity, we performed amino acid sequence alignments, phylogenetic analysis, homology modeling and docking simulations. We found that plant CMOs form a monophyletic subfamily within the Rieske/mononuclear non-heme oxygenases family with two clades: CMO1 and CMO2, the latter diverging from CMO1 after gene duplication. CMO1 enzymes are present in all plants; CMO2s only in the Amaranthaceae high-GB-accumulators plants. CMO2s, and particularly their mononuclear non-heme iron domain where the active site is located, evolved at a faster rate than CMO1s, which suggests positive selection. The homology model and docking simulations of the spinach CMO2 enzyme showed at the active site three aromatic residues forming a box with which the trimethylammonium group of choline could interact through cation-π interactions, and a glutamate, which also may interact with the trimethylammonium group through a charge-charge interaction. The aromatic box and the carboxylate have been shown to be critical for choline binding in other proteins. Interestingly, these residues are conserved in CMO2 proteins but not in CMO1 proteins, where two of these aromatic residues are leucine and the glutamate is asparagine. These findings reinforce our proposal that the CMO1s physiological substrate is not choline but a still unknown metabolite.

Low-cost HPV testing and the prevalence of cervical infection in asymptomatic populations in Guatemala.

BACKGROUND: A low cost and accurate method for detecting high-risk (HR) human papillomavirus (HPV) is important to permit HPV testing for cervical cancer prevention. We used a commercially available HPV method (H13, Hybribio) which was documented to function accurately in a reduced volume of cervical specimen to determine the most prevalent HPV types and the distribution of HPV infections in over 1795 cancer-free women in Guatemala undergoing primary screening for cervical cancer by cytology. METHODS: HR-HPV detection was attempted in cervical samples from 1795 cancer-free women receiving Pap smears using the Hybribio™ real-time PCR assay of 13 HR types. The test includes a globin gene internal control. HPV positive samples were sequenced to determine viral type. Age-specific prevalence of HPV was also assessed in the study population. RESULTS: A total of 13% (226/1717) of women tested HPV+, with 78 samples (4.3%) failing to amplify the internal control. The highest prevalence was found in younger women (< 30 years, 22%) and older ones (≥60 years, 15%). The six most common HR-HPV types among the 148 HPV+ typed were HPV16 (22%), HPV18 (11%), HPV39 (11%), HPV58 (10%), HPV52 (8%), and HPV45 (8%). CONCLUSIONS: In this sample of cancer free women in Guatemala, HPV16 was the most prevalent HR type in Guatemala and the age-specific prevalence curve peaked in younger ages. Women in the 30-59-year age groups had a prevalence of HR-HPV of 8%, however, larger studies to better describe the epidemiology of HPV in Guatemala are needed.

SDHD gene mutation in Mexican population whit carotid body tumor. / Mutación del gen SDHD en población mexicana con tumor del cuerpo carotídeo

Introduction: Among the U.S. population, the p81L SDHD (11q23) gene mutation is present in 6-36% of patients with sporadic carotid body tumor (CBT), but in familial cases is high as 80%. That is why the P81L mutation is used as a screening method for carotid body tumor in the U.S. Methods: We included 25 patients who underwent resection of a CBT from January 2010 to June 2015. After informed consent, a blood sample was taken for genetic testing on real-time polymerase chain reaction, in order to identify p81L mutation in the SDHD gene. The information was analyzed with descriptive statistics, using central tendency and description measures. Results: In our group, 92% were females, a mean age of 55.5 years, and 52% were Shamblin type II. The most common place of residence was Mexico City, 8% of the patients had family history, about 20% of the patients had a contralateral tumor and 16% had antecedent of another kind of tumor, 4 (16%) p81L SDHD gene mutations were detected, all of them were heterozygous. Conclusions: The p81L mutation in the SDHD gene was found in the Mexican population in higher grade that in the U.S. population, which explain the high incidence of this pathology in our country, but we need more studies about this subject.

Introducción: La mutación p81L del gen SDHD (11q23) se encuentra presente en el 6-36% de los pacientes con tumores del cuerpo carotídeo (TCC) esporádicos y hasta en el 80% de los que presentan TCC familiares. En los EE.UU. se usa como método de cribado para TCC. Método: Se incluyeron 25 pacientes consecutivos operados de resección de TCC entre enero de 2010 y junio de 2015. Se les tomó muestra sanguínea venosa que se sometió a reacción en cadena de la polimerasa en tiempo real para identificar la mutación p81L del gen SDHD (11q23). La información se analizó con estadística descriptiva mediante medidas de tendencia central y dispersión. Resultados: Del grupo en estudio, el 92% eran mujeres, la edad promedio era de 55.5 años y el 52% tenían tumor Shamblin tipo II. El lugar de residencia más frecuente fue la Ciudad de México. El 8% presentaban antecedentes familiares, el 20% tumor bilateral y el 16% presentaron un tumor en otra región. Se encontró la mutación p81L del gen SDHD (11q23) en el 16% de los pacientes de forma heterocigota. Conclusiones: La mutación p81L del gen SDHD se encuentra presente en la población mexicana en un grado más elevado que lo reportado en los EE.UU., lo que podría explicar la alta incidencia en nuestro medio.

ß- Adrenoceptors activate hepatic glutathione efflux through an unreported pathway.

The physiological regulation of hepatic glutathione efflux by catecholamines is poorly understood. The purpose of this work was to review the role of adrenergic receptors (AR) on total glutathione (GT) efflux in rat liver. Two models were used: isolated hepatocytes and perfused livers. In hepatocytes 10 µM adrenaline (Adr), but not isoproterenol (Iso) a ß-AR agonist, or phenylephrine (Phe) an α1-AR agonist, (in a Krebs-Henseleit buffer (KHB) enriched with Ca2+ and some aminoacids) increased in 13% GT efflux. In livers perfused with KHB, Adr or Iso at 1 µmolar doses (but not Phe) stimulated 11-fold initial velocity of GT release, but only during the first 2 min of perfusion. This immediate response progressively disappeared during the following 15 min of perfusion. A second phase of GT efflux, observed between 2 and 14 min of perfusion, mimics the one reported earlier in isolated hepatocytes. The ED50 for Adr and Iso activation are in the range of 320 nM and 10 nM, respectively. Iso-mediated GT release requires Ca2+ to work, and was prevented by H89, glibenclamide, cystic fibrosis transmembrane regulator (CFTR) antibodies, and a direct CFTR inhibitor. This short-lived GT release system is associated to PKA activation and probably operates through CFTR.

Fatty acid addition and thermotolerance of Kluyveromyces marxianus.

Membrane fatty acid composition has an important role in yeast stress resistance, particularly in temperature tolerance. Most studies investigating temperature and membrane fatty acids use the yeast Saccharomyces cerevisiae without considering other yeasts, such as Kluyveromyces marxianus, which has physiological differences and industrial advantages with respect to S. cerevisiae. One of the primary traits of K. marxianus is its thermotolerance. The effect of fatty acid addition (oleic acid, linoleic acid, linolenic acid and araquidic acid) on the thermotolerance of the K. marxianus strain SLP1 was evaluated. SLP1 yeast exhibited temperature tolerance of up to 50°C; at 55°C, viability was reduced significantly, probably due to an increase in the generation of reactive oxygen chemical species. Externally added fatty acids were incorporated in the yeast membrane, increasing their proportion to approximately 70%, thereby changing membrane fluidity. SLP1 cells supplemented with polyunsaturated fatty acids decreased cell thermotolerance and increased the degree of lipoperoxidation, while arachidic acid addition exhibited a tendency to increase yeast thermotolerance.