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HIV prevalence among transgender women (TW) in Tijuana, Mexico is estimated at 22%. Pre-exposure prophylaxis (PrEP) reduces the risk of HIV acquisition by > 90%, though uptake in Tijuana has been low due to limited availability. The interplay between PrEP and gender stigmas may also serve as a barrier to PrEP uptake among TW in Tijuana. Experiences of gender- and PrEP- stigmas were assessed quantitatively (Quan) among 110 HIV-negative TW and qualitatively (Qual) among 17 TW through semi-structured interviews guide by the Health Stigma and Discrimination Framework. Qual findings were triangulated with Quant data to identify factors that may support gender affirmation and reduce PrEP stigma in an explanatory sequential Quan â Qual fashion. Most participants were < 40 years of age (80%), while approximately half had at least a high school education (48.2%) and were accessing gender-affirming hormone therapy (56.4%). Mean expectations of gender stigma were greatest for endorsing negative future expectations from others (M = 17.69; possible range 0-36). PrEP stigma was prominent among those who associated negative stereotypes with PrEP users, such as poor judgment (M = 45.91; possible range 14-70) and high personal risk attributes (M = 28.61; possible range 12-60). While PrEP knowledge was low among the qualitative sample, participants identified gender-, PrEP-, and intersectional- stigmas as potential barriers to PrEP uptake. Participants suggested that resilience strategies used to combat gender stigma could also mitigate PrEP stigma. Enhancing resilience skills at the intersection of gender and PrEP stigma may reduce these barriers, facilitating greater PrEP uptake as it becomes more available in Mexico.
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Fármacos Anti-HIV , Infecções por HIV , Profilaxia Pré-Exposição , Estigma Social , Pessoas Transgênero , Humanos , Pessoas Transgênero/psicologia , Pessoas Transgênero/estatística & dados numéricos , México/epidemiologia , Feminino , Infecções por HIV/prevenção & controle , Adulto , Masculino , Fármacos Anti-HIV/uso terapêutico , Fármacos Anti-HIV/administração & dosagem , Pesquisa Qualitativa , Entrevistas como Assunto , Pessoa de Meia-Idade , Aceitação pelo Paciente de Cuidados de Saúde/estatística & dados numéricos , Aceitação pelo Paciente de Cuidados de Saúde/psicologia , Conhecimentos, Atitudes e Prática em Saúde , Adulto JovemRESUMO
Fusarium wilt of banana (FWB) is the most limiting disease in this crop. The phytosanitary emergency caused by FWB since 2019 in Colombia has required the development of ecofriendly control methods. The aim of this study was to test the effectiveness of microbial-based biofungicides against FWB caused by Fusarium oxysporum f. sp. cubense race 1 (Foc R1) and correlate such effect with plant physiological parameters. Five Trichoderma (T1 to T4 and T9) and four Bacillus (T5 to T8)-based biofungicides were evaluated in pot experiments. In vitro, dual confrontation tests were also carried out to test whether the in vitro effects on Foc growth were consistent with the in vivo effects. While Trichoderma-based T3, T4, and T9, and Bacillus-based T8, significantly reduced the growth of Foc R1 in vitro, Trichoderma-based T1, T3, T4, and T9 temporarily reduced the Foc population in the soil. However, the incidence progress of FWB was significantly reduced by Bacterial-based T7 (74% efficacy) and Trichoderma-based T2 (50% efficacy). The molecular analysis showed that T7 prevented the inner tissue colonization by Foc R1 in 80% of inoculated plants. The T2, T4, T7, and T9 treatments mitigated the negative effects caused by Foc R1 on plant physiology and growth. Our data allowed us to identify three promising treatments to control FWB, reducing the progress of the disease, delaying the colonization of inner tissue, and mitigating physiological damages. Further studies should be addressed to determine the modes of action of the biocontrol agents against Foc and validate the utilization in the field.
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The banana is one of Colombia's main export products. However, production is seriously affected by Fusarium wilt of banana, which is the most destructive disease caused by the fungus Fusarium oxysporum f. sp. cubense tropical race 4 (Foc TR4). Currently, management strategies focus on containment and biosecurity protocols to prevent its spread to territories that are free of this disease. This study aimed to evaluate nine quaternary ammonium-based disinfectants (i.e., quaternary ammonium compounds [QACs]) in vitro in Colombia on reproductive (microconidia and macroconidia) and resistance structures (chlamydospores) of Foc race 1 (R1) and tropical race 4 (TR4), with and without soil, to determine the influence of organic matter and soil texture on the action of QACs. A method for inhibiting the action of QACs was standardized and evaluated at 1,200 ppm with a contact time of ≤30 s while evaluating the soil-inoculum and soil-disinfectant interactions. In the soil-inoculum interaction, the efficacy of QACs was 100% in the reproductive and resistance structures of Foc R1 and TR4 without soil. However, in the soil-disinfectant interaction, only QAC4 controlled the pathogen at 100%. The presence of organic matter influenced the biocidal action of the QACs, and fine textures had a greater reducing effect on the concentration. The soil decreased the efficacy of the QACs and, therefore, must be removed from contaminated boots before treatments are applied.
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OBJETIVO: en la formación del estudiante de medicina, el internado rotatorio es un puente al inicio de su carrera profesional bajo una continua relación con los docentes instructores y los pacientes, esto implica un nexo entre la teoría de años previos y la aplicación práctica de su último año de pregrado; el objetivo de este trabajo se basó en determinar si esta relación se favorece con la aplicación del Aprendizaje Basado en Problemas (ABP). MÉTODOS: una primera etapa corresponde al diagnóstico de necesidades, sobre la base de una encuesta y una entrevista a grupo focal. En una segunda etapa de Investigación-Acción, se aplicó la metodología del ABP y se evaluó la misma con un cuestionario de guías de Co y Auto-evaluación y además con una guía de observación directa. RESULTADOS: los estudiantes manifestaron que los docentes están preparados y que el Hospital Univalle cuenta con buena estructura, sin embargo bajo un trabajo excesivo, de difícil adaptación y hasta con una mala relación con el docente, admitieron otras limitantes, como el cansancio de algunos pacientes por tantos periodos de anamnesis, el poco interés de los propios docentes y la aplicación de castigos por algunas fallas, asociados a una posición imponente de los docentes, generando temor. Citaron estrategias de evaluación como el repaso diario, los exámenes orales o escritos, la resolución de casos clínicos. Se destacó que el ABP es un método productivo, innovador y creativo que despierta la curiosidad e interés; además el uso de conocimientos previos y nuevos permite la reflexión en forma permanente e incentiva al discernimiento, sin ningún tipo de presión ni temor a ser castigados. CONCLUSIÓN: la aplicación del ABP en los procesos educativos es recomendable, con horarios accesibles, con adecuada estructura y un cronograma de trabajo, donde se debe instruir, preparar al estudiante y docentes. Toda esta innovación, permite la articulación de la teoría y la práctica, algunas limitaciones son la dificultad en el cumplimiento de la planificación, falta de hábito de los estudiantes y docentes, prefiriendo en muchas oportunidades las clases magistrales. En este momento de inminente proceso de renovación, de los paradigmas antiguos con la enseñanza conductual, es imperioso implementar diseños curriculares que tomen en cuenta estrategias de enseñanza y aprendizaje activos y con mucha auto-reflexión. (AU)
OBJECTIVE: in the training of the medical student, the rotary internship is a bridge at the beginning of his professional career under a continuous relationship with the teaching teachers and the patients, this implies a link between the theory of previous years and the practical application of his last year undergraduate; The objective of this work was based on determining if this relationship favors the application of Problem Based Learning (ABP). Methods METHODS: a first stage corresponds to the diagnosis of needs, based on a survey and a focus group interview. In a second stage of Research-Action, the ABP methodology was applied and it was evaluated with a questionnaire of Co and Self-evaluation guides and also with a direct observation guide. Results: : the students stated that the teachers are prepared and that the Univalle Hospital has a good structure, nevertheless under excessive work, difficult to adapt and even with a bad relationship with the teacher;,admitted other limitations, such as the fatigue of some patients for so many periods of history, the lack of interest of the teachers themselves and the application of punishment for some failures, associated with an imposing position of teachers, generating fear. They cited evaluation strategies such as daily review, oral or written exams, and the resolution of clinical cases. It was emphasized that the ABP is a productive, innovative and creative method that arouses curiosity and interest; In addition, the use of prior and new knowledge allows permanent reflection and encourages discernment, without any pressure or fear of being punished. CONCLUSION: the application of ABP in educational processes is recommended, with accessible schedules, with adequate structure and a work schedule, where you must instruct, prepare the student and teachers. All this innovation allows the articulation of theory and practice, Some limitations are the difficulty in fulfilling the planning, lack of habit of the students and teachers, preferring many times the master classes. In this moment of imminent process of renewal, of the old paradigms with behavioral teaching, it is imperative to implement curricular designs that take into account active teaching and learning strategies and with a lot of self-reflection.
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Adaptação a Desastres , Internato e Residência , Ensino , FadigaRESUMO
BACKGROUND: One of the major problems in the production of lipids for biotechnological purposes using microalgae is maintaining a high productivity of these molecules without reducing cellular biomass. High production rates are usually obtained by cultivating microalgae under different stress conditions. However, many of these changes usually result in lower biomass productivity. Therefore, the optimization of the culture conditions and genetic modification techniques in these organisms is needed to generate robust new strains for profitable economic use. RESULTS: In this work, we describe a new strategy for random mutation of genomic DNA in the microalgae Nannochloropsis oceanica by insertion of a Transposome complex Tn5. This complex contains an antibiotic-resistance cassette commanded by a CMV viral promoter that allows high efficiency of transformation and the generation of mutants. This strategy, complemented with a large-scale identification and selection system for mutants, such as flow cytometry with cell selection, allowed us to obtain clonal cultures of mutants with altered phenotypes in the accumulation of intracellular lipids. The characterization of some of these mutants uncovered new genes that are likely to be involved in the regulation of lipid synthesis, revealing possible cellular responses that influence the intracellular homeostasis of lipids. CONCLUSION: The strategies proposed here are easy to implement in different types of microalgae and provide a promising scenario for improving biotechnological applications.
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Resumen (analítico): En este artículo se comprende el sentido de algunos lineamientos nacionales e internacionales sobre la infancia y su relación con el proyecto educativo para Colombia. Se hizo un estudio cualitativo, de tipo descriptivo, analítico y documental. La metodología empleada fue el análisis de contenido de tipo semántico, en tanto que la población estuvo conformada por un conjunto de documentos oficiales que orientan lineamientos para la formulación de políticas públicas en Colombia y Latinoamérica. Se concluyó que la infancia es solo una estrategia de inversión para contribuir al desarrollo económico del país, como una inversión que tiene su tasa de retorno en la etapa adulta. De este modo, la idea de desarrollo infantil se sustenta en una propuesta educativa instrumental, ligada a la lógica neoliberal del capital humano.
Abstract (analytical): This article explores the meaning of national and international guidelines on childhood and their relation with educational projects in Colombia. A qualitative study was carried out using documentary, descriptive and analytical approaches. The methodology used was semantic content analysis, while the population consisted of official documents that have the purpose of providing guidelines for the formulation of public policies in Colombia and Latin America. The conclusion of the researchers was that childhood is only considered as an investment strategy that contributes to a country's economic development in the future, an investment for which the return comes when these children reach adulthood. Subsequently, the idea of childhood development is based on an instrumental educational proposal that is associated with a neoliberal logic based on human capital.
Resumo (analítico): Este artigo teve como objetivo compreender o significado de algumas diretrizes nacionais e internacionais sobre as crianças e sua relação com o projeto educacional para Colômbia. Por tanto realizou-se um estudo descritivo-analítico, qualitativo e documental. A metodologia utilizada foi a análise do conteúdo do tipo semântico e a população foi conformada por documentos oficiais que orientam diretrizes para a formulação de políticas públicas na Colômbia e na América Latina. Concluiu-se que a infância uma estratégia de investimento para contribuir ou contribuir para o desenvolvimento econômico dos países para o futuro, como um investimento que tem seu retorno na fase adulta. Desta forma, a idéia de desenvolvimento infantil baseia-se em uma proposta instrumental educacional, associada à lógica neoliberal do capital humano.
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Política PúblicaRESUMO
For tolerating extreme desiccation, cyanobacteria are known to produce both compatible solutes at intracellular level and a copious amount of exopolysaccharides as a protective coat. However, these molecules make cyanobacterial cells refractory to a broad spectrum of cell disruption methods, hindering genome sequencing, and molecular studies. In fact, few genomes are already available from cyanobacteria from extremely desiccated environments such as deserts. In this work, we report the 5.4 Mbp draft genome (with 100% of completeness in 105 contigs) of Gloeocapsopsis sp. UTEX B3054 (subsection I; Order Chroococcales), a cultivable sugar-rich and hardly breakable hypolithic cyanobacterium from the Atacama Desert. Our in silico analyses focused on genomic features related to sugar-biosynthesis and adaptation to dryness. Among other findings, screening of Gloeocapsopsis genome revealed a unique genetic potential related to the biosynthesis and regulation of compatible solutes and polysaccharides. For instance, our findings showed for the first time a novel genomic arrangement exclusive of Chroococcaceae cyanobacteria associated with the recycling of trehalose, a compatible solute involved in desiccation tolerance. Additionally, we performed a comparative genome survey and analyses to entirely predict the highly diverse pool of glycosyltransferases enzymes, key players in polysaccharide biosynthesis and the formation of a protective coat to dryness. We expect that this work will set the fundamental genomic framework for further research on microbial tolerance to desiccation and to a wide range of other extreme environmental conditions. The study of microorganisms like Gloeocapsopsis sp. UTEX B3054 will contribute to expand our limited understanding regarding water optimization and molecular mechanisms allowing extremophiles to thrive in xeric environments such as the Atacama Desert.
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Members of the genus Cylindrospermopsis represent an important environmental and health concern. Strains CS-508 and MVCC14 of C. raciborskii were isolated from freshwater reservoirs located in Australia and Uruguay, respectively. While CS-508 has been reported as non-toxic, MVCC14 is a saxitoxin (STX) producer. We annotated the draft genomes of these C. raciborskii strains using the assembly of reads obtained from Illumina MiSeq sequencing. The final assemblies resulted in genome sizes close to 3.6 Mbp for both strains and included 3202 ORFs for CS-508 (in 163 contigs) and 3560 ORFs for MVCC14 (in 99 contigs). Finally, both the average nucleotide identity (ANI) and the similarity of gene content indicate that these two genomes should be considered as strains of the C. raciborskii species.
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Composition, carbon and nitrogen uptake, and gene transcription of microbial mat communities in Porcelana neutral hot spring (Northern Chilean Patagonia) were analyzed using metagenomics, metatranscriptomics and isotopically labeled carbon (H13CO3) and nitrogen (15NH4Cl and K15NO3) assimilation rates. The microbial mat community included 31 phyla, of which only Cyanobacteria and Chloroflexi were dominant. At 58°C both phyla co-occurred, with similar contributions in relative abundances in metagenomes and total transcriptional activity. At 66°C, filamentous anoxygenic phototrophic Chloroflexi were >90% responsible for the total transcriptional activity recovered, while Cyanobacteria contributed most metagenomics and metatranscriptomics reads at 48°C. According to such reads, phototrophy was carried out both through oxygenic photosynthesis by Cyanobacteria (mostly Mastigocladus) and anoxygenic phototrophy due mainly to Chloroflexi. Inorganic carbon assimilation through the Calvin-Benson cycle was almost exclusively due to Mastigocladus, which was the main primary producer at lower temperatures. Two other CO2 fixation pathways were active at certain times and temperatures as indicated by transcripts: 3-hydroxypropionate (3-HP) bi-cycle due to Chloroflexi and 3-hydroxypropionate-4-hydroxybutyrate (HH) cycle carried out by Thaumarchaeota. The active transcription of the genes involved in these C-fixation pathways correlated with high in situ determined carbon fixation rates. In situ measurements of ammonia assimilation and nitrogen fixation (exclusively attributed to Cyanobacteria and mostly to Mastigocladus sp.) showed these were the most important nitrogen acquisition pathways at 58 and 48°C. At 66°C ammonia oxidation genes were actively transcribed (mostly due to Thaumarchaeota). Reads indicated that denitrification was present as a nitrogen sink at all temperatures and that dissimilatory nitrate reduction to ammonia (DNRA) contributed very little. The combination of metagenomic and metatranscriptomic analysis with in situ assimilation rates, allowed the reconstruction of day and night carbon and nitrogen assimilation pathways together with the contribution of keystone microorganisms in this natural hot spring microbial mat.
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In fjord systems, Harmful Algal Blooms (HABs) not only constitute a serious problem when affecting the wildlife and ecosystems, but also human health and economic activities related to the marine environment. This is mostly due to a broad spectrum of toxic compounds produced by several members of the phytoplankton. Nevertheless, a deep coverage of the taxonomic diversity and composition of phytoplankton species and phycotoxin profiles in HAB prone areas are still lacking and little is known about the relationship between these fundamental elements for fjord ecosystems. In this study, a detailed molecular and microscopic characterization of plankton communities was performed, together with an analysis of the occurrence and spatial patterns of lipophilic toxins in a HAB prone area, located in the Southeastern Pacific fjord region. Microscopy and molecular analyses based on the 18S rRNA gene fragment indicated high diversity and taxonomic homogeneity among stations. Four toxigenic genera were identified: Pseudo-nitzschia, Dinophysis, Prorocentrum, and Alexandrium. In agreement with the detected species, liquid chromatography coupled with mass spectrometry revealed the presence of domoic acid (DA), pectenotoxin-2 (PTX-2), dinophysistoxin-2 (DTX-2), and 13-desmethyl spirolide C (SPX-1). Furthermore, a patchy distribution among DA in different net haul size fractions was found. Our results displayed a complex phytoplankton-phycotoxin pattern and for the first time contribute to the characterization of high-resolution phytoplankton community composition and phycotoxin distribution in fjords of the Southeastern Pacific region.
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Biodiversidade , Estuários , Toxinas Marinhas/química , Toxinas Marinhas/metabolismo , Fitoplâncton/genética , Fitoplâncton/metabolismo , Chile , Sequenciamento de Nucleotídeos em Larga EscalaRESUMO
Cyanobacteria are widely distributed primary producers with significant implications for the global biogeochemical cycles of carbon and nitrogen. Diazotrophic cyanobacteria of subsection V (Order Stigonematales) are particularly ubiquitous in photoautotrophic microbial mats of hot springs. The Stigonematal cyanobacterium strain CHP1 isolated from the Porcelana hot spring (Chile) was one of the major contributors of the new nitrogen through nitrogen fixation. Further morphological and genetic characterization verified that the strain CHP1 belongs to Stigonematales, and it formed a separate clade together with other thermophiles of the genera Fischerella and Mastigocladus. Strain CHP1 fixed maximum N2 in the light, independent of the temperature range. At 50°C nifH gene transcripts showed high expression during the light period, whereas the nifH gene expression at 45°C was arrhythmic. The strain displayed a high affinity for nitrate and a low tolerance for high ammonium concentrations, whereas the narB and glnA genes showed higher expression in light and at the beginning of the dark phase. It is proposed that Mastigocladus sp. strain CHP1 would represent a good model for the study of subsection V thermophilic cyanobacteria, and for understanding the adaptations of these photoautotrophic organisms inhabiting microbial mats in hot springs globally.
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Cianobactérias/efeitos dos fármacos , Cianobactérias/efeitos da radiação , Fontes Termais/microbiologia , Nitrogênio/metabolismo , Compostos de Amônio/metabolismo , Chile , Análise por Conglomerados , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Perfilação da Expressão Gênica , Glutamato-Amônia Ligase/biossíntese , Luz , Nitratos/metabolismo , Fixação de Nitrogênio , Oxirredutases/biossíntese , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , TemperaturaRESUMO
Neuroinflammation involves the activation of glial cells, which is associated to the progression of neurodegeneration in Parkinson's disease. Recently, we and other researchers demonstrated that dopamine receptor D3 (D3R)-deficient mice are completely refractory to neuroinflammation and consequent neurodegeneration associated to the acute intoxication with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). In this study we examined the therapeutic potential and underlying mechanism of a D3R-selective antagonist, PG01037, in mice intoxicated with a chronic regime of administration of MPTP and probenecid (MPTPp). Biodistribution analysis indicated that intraperitoneally administered PG01037 crosses the blood-brain barrier and reaches the highest concentration in the brain 40 min after the injection. Furthermore, the drug was preferentially distributed to the brain in comparison to the plasma. Treatment of MPTPp-intoxicated mice with PG01037 (30 mg/kg, administrated twice a week for five weeks) attenuated the loss of dopaminergic neurons in the substantia nigra pars compacta, as evaluated by stereological analysis, and the loss of striatal dopaminergic terminals, as determined by densitometric analyses of tyrosine hydroxylase and dopamine transporter immunoreactivities. Accordingly, the treatment resulted in significant improvement of motor performance of injured animals. Interestingly, the therapeutic dose of PG01037 exacerbated astrogliosis and resulted in increased ramification density of microglial cells in the striatum of MPTPp-intoxicated mice. Further analyses suggested that D3R expressed in astrocytes favours a beneficial astrogliosis with anti-inflammatory consequences on microglia. Our findings indicate that D3R-antagonism exerts a therapeutic effect in parkinsonian animals by reducing the loss of dopaminergic neurons in the nigrostriatal pathway, alleviating motor impairments and modifying the pro-inflammatory phenotype of glial cells.
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Benzamidas/administração & dosagem , Neurônios Dopaminérgicos/efeitos dos fármacos , Encefalite/prevenção & controle , Fármacos Neuroprotetores/administração & dosagem , Transtornos Parkinsonianos/prevenção & controle , Piridinas/administração & dosagem , Receptores de Dopamina D3/antagonistas & inibidores , Animais , Astrócitos/efeitos dos fármacos , Astrócitos/metabolismo , Benzamidas/sangue , Benzamidas/farmacologia , Corpo Estriado/efeitos dos fármacos , Corpo Estriado/patologia , Neurônios Dopaminérgicos/patologia , Encefalite/etiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Microglia/efeitos dos fármacos , Atividade Motora/efeitos dos fármacos , Fármacos Neuroprotetores/sangue , Fármacos Neuroprotetores/farmacologia , Doença de Parkinson/complicações , Doença de Parkinson/prevenção & controle , Transtornos Parkinsonianos/complicações , Parte Compacta da Substância Negra/efeitos dos fármacos , Parte Compacta da Substância Negra/patologia , Piridinas/sangue , Piridinas/farmacologia , Receptores de Dopamina D3/metabolismoRESUMO
Techniques such as immunoflorescence are widely used to determine subcellular distribution of proteins. Here we report on a method to immunolocalize proteins in Anabaena sp. PCC7120 with fluorophore-conjugated antibodies by fluorescence microscopy. This method improves the permeabilization of cyanobacterial cells and minimizes the background fluorescence for non-specific attachments. In this protocol, rabbit antibodies were raised against the synthetic peptide of CyDiv protein ( Mandakovic et al., 2016 ). The secondary antibody conjugated to the fluorophore Alexa488 was used due to its different emission range in comparison to the autofluorescence of the cyanobacterium.
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Cylindrospermopsis raciborskii is a freshwater cyanobacterium producing bloom events and toxicity in drinking water source reservoirs. We present the first genome sequence for C. raciborskii CS505 (Australia), containing one 4.1-Mbp chromosome and one 110-Kbp plasmid having G+C contents of 40.3% (3933 genes) and 39.3% (111 genes), respectively.
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Cell division in bacteria has been studied mostly in Escherichia coli and Bacillus subtilis, model organisms for Gram-negative and Gram-positive bacteria, respectively. However, cell division in filamentous cyanobacteria is poorly understood. Here, we identified a novel protein, named CyDiv (Cyanobacterial Division), encoded by the all2320 gene in Anabaena sp. PCC 7120. We show that CyDiv plays a key role during cell division. CyDiv has been previously described only as an exclusive and conserved hypothetical protein in filamentous cyanobacteria. Using polyclonal antibodies against CyDiv, we showed that it localizes at different positions depending on cell division timing: poles, septum, in both daughter cells, but also in only one of the daughter cells. The partial deletion of CyDiv gene generates partial defects in cell division, including severe membrane instability and anomalous septum localization during late division. The inability to complete knock out CyDiv strains suggests that it is an essential gene. In silico structural protein analyses and our experimental results suggest that CyDiv is an FtsB/DivIC-like protein, and could therefore, be part of an essential late divisome complex in Anabaena sp. PCC 7120.
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A growing body of evidence suggests that learned fear may be related to the function of the interoceptive insular cortex. Using an auditory fear conditioning paradigm in rats, we show that the inactivation of the posterior insular cortex (pIC), the target of the interoceptive thalamus, prior to training produced a marked reduction in fear expression tested 24h later. Accordingly, post-training anisomycin infused immediately, but not 6h after, also reduced fear expression tested the following day, supporting a role for the pIC in consolidation of fear memory. The long-term (ca. a week) and reversible inactivation of the pIC with the sodium channel blocker neosaxitoxin, immediately after fear memory reactivation induced a progressive decrease in the behavioral expression of conditioned fear. In turn, we observed that fear memory reactivation is accompanied by an enhanced expression of Fos and Zif268, early genes involved in neural activity and plasticity. Taken together these data indicate that the pIC is involved in the regulation of fear memories.
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Comportamento Animal/fisiologia , Córtex Cerebral/fisiologia , Condicionamento Psicológico/fisiologia , Medo/fisiologia , Interocepção/fisiologia , Memória/fisiologia , Animais , Anisomicina/farmacologia , Comportamento Animal/efeitos dos fármacos , Córtex Cerebral/efeitos dos fármacos , Condicionamento Psicológico/efeitos dos fármacos , Proteína 1 de Resposta de Crescimento Precoce/fisiologia , Inibidores Enzimáticos/farmacologia , Medo/efeitos dos fármacos , Genes fos/fisiologia , Interocepção/efeitos dos fármacos , Masculino , Memória/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Saxitoxina/análogos & derivados , Saxitoxina/farmacologia , Bloqueadores dos Canais de Sódio/farmacologia , TálamoRESUMO
Radical trachelectomy is the treatment of choice in women with early-stage cervical cancer wishing to preserve fertility. Radical trachelectomy can be performed with a vaginal, abdominal, or laparoscopic/robotic approach. Vaginal radical trachelectomy (VRT) is generally not offered to patients with tumors 2cm or larger because of a high recurrence rate. There are no conclusive recommendations regarding the safety of abdominal radical trachelectomy (ART) or laparoscopic radical trachelectomy (LRT) in such patients. Several investigators have used neoadjuvant chemotherapy in patients with tumors 2 to 4cm to reduce tumor size so that fertility preservation may be offered. However, to our knowledge, no published study has compared outcomes between patients with cervical tumors 2cm or larger who underwent immediate radical trachelectomy and those who underwent neoadjuvant chemotherapy followed by radical trachelectomy. We conducted a literature review to compare outcomes with these 2 approaches. Our main endpoints for evaluation were oncological and obstetrical outcomes. The fertility preservation rate was 82.7%, 85.1%, 89%; and 91.1% for ART (tumors larger than >2cm), ART (all sizes), NACT followed by surgery and VRT (all sizes); respectively. The global pregnancy rate was 16.2%, 24% and 30.7% for ART, VRT, and NACT followed by surgery; respectively. The recurrence rate was 3.8%, 4.2%, 6%, 7.6% and 17% for ART (all sizes), VRT (all sizes), ART (tumors>2cm), NACT followed by surgery, and VRT (tumors>2cm). These outcomes must be considered when offering a fertility sparing technique to patients with a tumor larger than 2cm.
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Neoplasias do Colo do Útero/tratamento farmacológico , Neoplasias do Colo do Útero/cirurgia , Quimioterapia Adjuvante , Feminino , Procedimentos Cirúrgicos em Ginecologia/métodos , Humanos , Terapia Neoadjuvante , Estadiamento de Neoplasias , Resultado do Tratamento , Neoplasias do Colo do Útero/patologiaRESUMO
Cylindrospermopsis raciborskii CS-505 is an invasive freshwater filamentous cyanobacterium that when grown diazotrophically may develop trichomes of up to 100 vegetative cells while differentiating only two end heterocysts, the sole sites for their N2-fixation process. We examined the diazotrophic growth and intercellular transfer mechanisms in C. raciborskii CS-505. Subjecting cultures to a combined-nitrogen-free medium to elicit N2 fixation, the trichome length remained unaffected while growth rates decreased. The structures and proteins for intercellular communication showed that while a continuous periplasmic space was apparent along the trichomes, the putative septal junction sepJ gene is divided into two open reading frames and lacks several transmembrane domains unlike the situation in Anabaena, differentiating a 5-fold higher frequency of heterocysts. FRAP analyses also showed that the dyes calcein and 5-CFDA were taken up by heterocysts and vegetative cells, and that the transfer from heterocysts and 'terminal' vegetative cells showed considerably higher transfer rates than that from vegetative cells located in the middle of the trichomes. The data suggest that C. raciborskii CS-505 compensates its low-frequency heterocyst phenotype by a highly efficient transfer of the fixed nitrogen towards cells in distal parts of the trichomes (growing rapidly) while cells in central parts suffers (slow growth).
Assuntos
Cylindrospermopsis/fisiologia , Fixação de Nitrogênio , Tricomas/crescimento & desenvolvimento , Anabaena/genética , Anabaena/fisiologia , Proteínas de Bactérias/metabolismo , Biologia Computacional , Cylindrospermopsis/genética , Cylindrospermopsis/crescimento & desenvolvimento , Cylindrospermopsis/ultraestrutura , Fluoresceínas/metabolismo , Regulação Bacteriana da Expressão Gênica , Microscopia Eletrônica de Transmissão , Nitrogenase/metabolismo , Fases de Leitura Aberta , Periplasma/metabolismo , Fenótipo , Tricomas/fisiologiaRESUMO
Different environmental nitrogen sources play selective roles in the development of cyanobacterial blooms and noxious effects are often exacerbated when toxic cyanobacteria are dominant. Cylindrospermopsis raciborskii CS-505 (heterocystous, nitrogen fixing) and Raphidiopsis brookii D9 (non-N2 fixing) produce the nitrogenous toxins cylindrospermopsin (CYN) and paralytic shellfish toxins (PSTs), respectively. These toxin groups are biosynthesized constitutively by two independent putative gene clusters, whose flanking genes are target for nitrogen (N) regulation. It is not yet known how or if toxin biosynthetic genes are regulated, particularly by N-source dependency. Here we show that binding boxes for NtcA, the master regulator of N metabolism, are located within both gene clusters as potential regulators of toxin biosynthesis. Quantification of intra- and extracellular toxin content in cultures at early stages of growth under nitrate, ammonium, urea and N-free media showed that N-sources influence neither CYN nor PST production. However, CYN and PST profiles were altered under N-free medium resulting in a decrease in the predicted precursor toxins (doCYN and STX, respectively). Reduced STX amounts were also observed under growth in ammonium. Quantification of toxin biosynthesis and transport gene transcripts revealed a constitutive transcription under all tested N-sources. Our data support the hypothesis that PSTs and CYN are constitutive metabolites whose biosynthesis is correlated to cyanobacterial growth rather than directly to specific environmental conditions. Overall, the constant biosynthesis of toxins and expression of the putative toxin-biosynthesis genes supports the usage of qPCR probes in water quality monitoring of toxic cyanobacteria.