RESUMO
Circadian rhythms control organismal physiology throughout the day. At the cellular level, clock regulation is established by a self-sustained Bmal1-dependent transcriptional oscillator network. However, it is still unclear how different tissues achieve a synchronized rhythmic physiology. That is, do they respond independently to environmental signals, or require interactions with each other to do so? We show that unexpectedly, light synchronizes the Bmal1-dependent circadian machinery in single tissues in the absence of Bmal1 in all other tissues. Strikingly, light-driven tissue autonomous clocks occur without rhythmic feeding behavior and are lost in constant darkness. Importantly, tissue-autonomous Bmal1 partially sustains homeostasis in otherwise arrhythmic and prematurely aging animals. Our results therefore support a two-branched model for the daily synchronization of tissues: an autonomous response branch, whereby light entrains circadian clocks without any commitment of other Bmal1-dependent clocks, and a memory branch using other Bmal1-dependent clocks to "remember" time in the absence of external cues.
Assuntos
Fatores de Transcrição ARNTL/fisiologia , Relógios Circadianos/genética , Fatores de Transcrição ARNTL/metabolismo , Animais , Proteínas CLOCK/metabolismo , Relógios Circadianos/fisiologia , Ritmo Circadiano/genética , Comportamento Alimentar/fisiologia , Feminino , Homeostase , Luz , Masculino , Camundongos , Camundongos Knockout , Modelos Animais , Especificidade de Órgãos/fisiologia , Fotoperíodo , Núcleo Supraquiasmático/metabolismoRESUMO
During aging, stromal functions are thought to be impaired, but little is known whether this stems from changes of fibroblasts. Using population- and single-cell transcriptomics, as well as long-term lineage tracing, we studied whether murine dermal fibroblasts are altered during physiological aging under different dietary regimes that affect longevity. We show that the identity of old fibroblasts becomes undefined, with the fibroblast states present in young skin no longer clearly demarcated. In addition, old fibroblasts not only reduce the expression of genes involved in the formation of the extracellular matrix, but also gain adipogenic traits, paradoxically becoming more similar to neonatal pro-adipogenic fibroblasts. These alterations are sensitive to systemic metabolic changes: long-term caloric restriction reversibly prevents them, whereas a high-fat diet potentiates them. Our results therefore highlight loss of cell identity and the acquisition of adipogenic traits as a mechanism underlying cellular aging, which is influenced by systemic metabolism.
Assuntos
Adipogenia , Senescência Celular , Fibroblastos/metabolismo , Envelhecimento da Pele , Animais , Restrição Calórica , Matriz Extracelular/genética , Matriz Extracelular/metabolismo , Camundongos , Camundongos TransgênicosRESUMO
Normal homeostatic functions of adult stem cells have rhythmic daily oscillations that are believed to become arrhythmic during aging. Unexpectedly, we find that aged mice remain behaviorally circadian and that their epidermal and muscle stem cells retain a robustly rhythmic core circadian machinery. However, the oscillating transcriptome is extensively reprogrammed in aged stem cells, switching from genes involved in homeostasis to those involved in tissue-specific stresses, such as DNA damage or inefficient autophagy. Importantly, deletion of circadian clock components did not reproduce the hallmarks of this reprogramming, underscoring that rewiring, rather than arrhythmia, is associated with physiological aging. While age-associated rewiring of the oscillatory diurnal transcriptome is not recapitulated by a high-fat diet in young adult mice, it is significantly prevented by long-term caloric restriction in aged mice. Thus, stem cells rewire their diurnal timed functions to adapt to metabolic cues and to tissue-specific age-related traits.
Assuntos
Células-Tronco Adultas/patologia , Senescência Celular , Ritmo Circadiano , Epiderme/patologia , Músculo Esquelético/patologia , Células-Tronco Adultas/fisiologia , Animais , Autofagia , Restrição Calórica , Relógios Circadianos , Dano ao DNA , Dieta Hiperlipídica , Homeostase , Camundongos , Estresse Fisiológico , TranscriptomaRESUMO
The fact that the identity of the cells that initiate metastasis in most human cancers is unknown hampers the development of antimetastatic therapies. Here we describe a subpopulation of CD44bright cells in human oral carcinomas that do not overexpress mesenchymal genes, are slow-cycling, express high levels of the fatty acid receptor CD36 and lipid metabolism genes, and are unique in their ability to initiate metastasis. Palmitic acid or a high-fat diet specifically boosts the metastatic potential of CD36+ metastasis-initiating cells in a CD36-dependent manner. The use of neutralizing antibodies to block CD36 causes almost complete inhibition of metastasis in immunodeficient or immunocompetent orthotopic mouse models of human oral cancer, with no side effects. Clinically, the presence of CD36+ metastasis-initiating cells correlates with a poor prognosis for numerous types of carcinomas, and inhibition of CD36 also impairs metastasis, at least in human melanoma- and breast cancer-derived tumours. Together, our results indicate that metastasis-initiating cells particularly rely on dietary lipids to promote metastasis.
Assuntos
Anticorpos Neutralizantes/farmacologia , Antígenos CD36/antagonistas & inibidores , Neoplasias Bucais/patologia , Metástase Neoplásica/patologia , Metástase Neoplásica/prevenção & controle , Células-Tronco Neoplásicas/efeitos dos fármacos , Células-Tronco Neoplásicas/patologia , Animais , Anticorpos Neutralizantes/imunologia , Anticorpos Neutralizantes/uso terapêutico , Antígenos CD36/genética , Antígenos CD36/imunologia , Antígenos CD36/metabolismo , Proliferação de Células , Dieta Hiperlipídica/efeitos adversos , Modelos Animais de Doenças , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Receptores de Hialuronatos/metabolismo , Metabolismo dos Lipídeos/genética , Metástase Linfática/genética , Metástase Linfática/patologia , Masculino , Camundongos , Neoplasias Bucais/diagnóstico , Neoplasias Bucais/tratamento farmacológico , Neoplasias Bucais/metabolismo , Metástase Neoplásica/tratamento farmacológico , Metástase Neoplásica/genética , Células-Tronco Neoplásicas/metabolismo , Ácido Palmítico/administração & dosagem , Ácido Palmítico/metabolismo , Ácido Palmítico/farmacologia , Penetrância , Prognóstico , Transcriptoma , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
BACKGROUND: Single-incision laparoscopic cholecystectomy evolved from the traditional multiport laparoscopic technique. Prior trials have demonstrated improved cosmesis with the single-incision technique. Robotic single-site surgery minimizes the technical difficulties associated with laparoscopic single-incision approach. This is the first prospective, randomized, controlled study comparing robotic single-site cholecystectomy (RSSC) and multiport laparoscopic cholecystectomy (MPLC) in terms of cosmesis and patient satisfaction. METHODS: Patients with symptomatic benign gallbladder disease were randomized to RSSC or MPLC. Data included perioperative variables such as operative time, conversion and complications and cosmesis satisfaction, body image perception, quality of life using validated questionnaires, at postoperative visits of 2, 6 weeks and 3 months. RESULTS: One hundred thirty-six patients were randomized to RSSC (N = 83) and MPLC (N = 53) at 8 institutions. Both cohorts were dominated by higher enrollment of females (RSSC = 78%, MPLC = 92%). The RSSC and MPLC cohorts were otherwise statistically matched. Operative time was longer for RSSC (61 min vs. 44 min, P < 0.0001). There were no differences in complication rates. RSSC demonstrated a significant superiority in cosmesis satisfaction and body image perception (P value < 0.05 at every follow-up). There was no statistically significant difference in patient-reported quality of life. Multivariate analysis of female patients demonstrated significantly higher preference for RSSC over MPLC in cosmesis satisfaction and body image perception with no difference seen in overall quality of life. CONCLUSIONS: Results from this trial show that RSSC is associated with improved cosmesis satisfaction and body image perception without a difference in observed complication rate. The uncompromised safety and the improved cosmesis satisfaction and body image perception provided by RSSC for female patients support consideration of the robotic single-site approach. ClinicalTrials.gov identifier NCT01932216.
Assuntos
Colecistectomia Laparoscópica/métodos , Colecistectomia/métodos , Doenças da Vesícula Biliar/cirurgia , Procedimentos Cirúrgicos Robóticos/métodos , Adulto , Idoso , Imagem Corporal , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Duração da Cirurgia , Satisfação do Paciente , Estudos Prospectivos , Qualidade de Vida , Robótica/métodos , Inquéritos e QuestionáriosRESUMO
Cancer is a clonal malignant disease originated in a single cell and characterized by the accumulation of partially differentiated cells that are phenotypically reminiscent of normal stages of differentiation. Given the fact that human cancer is diagnosed at later stages and cannot be monitored during its natural evolution, the origin of tumors has been a subject of continuing discussion. Animal models provide a means to determine the identity of the cell-of-origin leading to malignancy and to develop new treatments. Recent findings in mice have shown that cancer stem cells could arise through a reprogramming-like mechanism, suggesting that genetic lesions that initiate the cancer process might be dispensable for tumor progression and maintenance. This review addresses the impact of these results toward a better understanding of carcinogenesis and proposes research avenues for tackling these issues in the future.
Assuntos
Diferenciação Celular , Neoplasias/patologia , Neoplasias/terapia , Células-Tronco Neoplásicas/patologia , Animais , Transformação Celular Neoplásica , Humanos , CamundongosRESUMO
The role of heterochromatin in cell fate specification during development is unclear. We demonstrate that loss of the lysine 9 of histone H3 (H3K9) methyltransferase G9a in the mammary epithelium results in de novo chromatin opening, aberrant formation of the mammary ductal tree, impaired stem cell potential, disrupted intraductal polarity, and loss of tissue function. G9a loss derepresses long terminal repeat (LTR) retroviral sequences (predominantly the ERVK family). Transcriptionally activated endogenous retroviruses generate double-stranded DNA (dsDNA) that triggers an antiviral innate immune response, and knockdown of the cytosolic dsDNA sensor Aim2 in G9a knockout (G9acKO) mammary epithelium rescues mammary ductal invasion. Mammary stem cell transplantation into immunocompromised or G9acKO-conditioned hosts shows partial dependence of the G9acKO mammary morphological defects on the inflammatory milieu of the host mammary fat pad. Thus, altering the chromatin accessibility of retroviral elements disrupts mammary gland development and stem cell activity through both cell-autonomous and non-autonomous mechanisms.
Assuntos
Retrovirus Endógenos , Histona-Lisina N-Metiltransferase , Glândulas Mamárias Animais/crescimento & desenvolvimento , Tecido Adiposo/crescimento & desenvolvimento , Tecido Adiposo/imunologia , Animais , Retrovirus Endógenos/genética , Retrovirus Endógenos/metabolismo , Feminino , Histona-Lisina N-Metiltransferase/metabolismo , Histonas/metabolismo , Imunidade , Glândulas Mamárias Animais/imunologiaRESUMO
BACKGROUND: Colloid fluids supplemented with adequate combinations of coagulation factor concentrates with the capability to restore coagulation could be a desirable future treatment component in massive transfusion. METHODS: Starting from a coagulation factor and blood cell-free albumin solution we added Prothrombin Complex Concentrate, Fibrinogen Concentrate and Factor XIII in different combinations and concentrations to analyze their properties to restore thromboelastometry parameters without the use of plasma. Further analysis under the presence of platelets was performed for comparability to whole blood conditions. RESULTS: Albumin solutions enriched with Fibrinogen Concentrate, Factor XIII and Prothrombin Complex Concentrate at optimized concentrations show restoring coagulation potential. Prothrombin Complex Concentrate showed sufficient thrombin formation for inducing fibrinogen polymerization. The combination of Prothrombin Complex Concentrate and Fibrinogen Concentrate led to the formation of a stable in vitro fibrin clot. Fibrinogen and Factor XIII showed excellent capacity to improve fibrin clot firmness expressed as Amplitude at 10 min and Maximal Clot Firmness. Fibrinogen alone, or in combination with Factor XIII, was able to restore normal Amplitude at 10 min and Maximal Clot Firmness values. In the presence of platelets, the thromboelastometry surrogate parameter for thrombin generation (Clotting Time) improves and normalizes when compared to whole blood. CONCLUSIONS: Combinations of coagulation factor concentrates suspended in albumin solutions can restore thromboelastometry parameters in the absence of plasma. This kind of artificial colloid fluids with coagulation-restoring characteristics might offer new treatment alternatives for massive transfusion. TRIAL REGISTRATION: Study registered at the institutional ethic committee "Institut de Recerca, Hospital Santa Creu i Sant Pau, with protocol number IIBSP-CFC-2013-165.
Assuntos
Albuminas/metabolismo , Fatores de Coagulação Sanguínea/metabolismo , Fator XIII/metabolismo , Fibrinogênio/metabolismo , Tromboelastografia/métodos , Coagulação Sanguínea/efeitos dos fármacos , Testes de Coagulação Sanguínea , Transfusão de Sangue , HumanosRESUMO
Pheochromocytoma is a rare neuroendocrine tumor diagnosed in 1:50,000 pregnancies. Normal physiologic changes associated with pregnancy often make early recognition difficult and diagnosis delayed. Treatment consists of medical followed by surgical intervention. This case of a 34-year African-American female diagnosed with an adrenal pheochromocytoma during her second trimester of pregnancy is the first reported case of successful robotic resection. The robot provided advantages, such as enhanced visualisation and freedom of dissection, within this confined space. These added benefits over traditional laparoscopy provide a means for performing difficult procedures within decreased space possibly allowing for interventions in later or larger pregnancies.
Assuntos
Neoplasias das Glândulas Suprarrenais/cirurgia , Adrenalectomia/métodos , Laparoscopia/métodos , Feocromocitoma/cirurgia , Complicações Neoplásicas na Gravidez/cirurgia , Neoplasias das Glândulas Suprarrenais/diagnóstico , Adulto , Feminino , Humanos , Feocromocitoma/diagnóstico , Gravidez , Segundo Trimestre da Gravidez , RobóticaRESUMO
BACKGROUND AND OBJECTIVE: It has been reported that the polymorphism M129V in the PRNP gene modifies the phenotype in all the subtypes of prion diseases in humans. All cases diagnosed to date as suffering the human variant of mad cow disease (vCJD) carry the allele 129M. In the last five years five cases of vCJD have been reported in Spain, three of them in Castilla y León (in western Spain). Observation of differences in the genotypic frequency of this polymorphism in different populations prompted us to analyze the distribution of genotypes of the V129M polymorphism in a population from Castilla y León to determine if there is an increased risk to develop vCJD in this region of Spain. PATIENTS AND METHOD: We studied the coding region of the PRNP gene containing codon 129 in 110 healthy individuals from Castilla y León. We amplified the DNA by PCR and allelic discrimination was performed after digestion with restriction enzyme NspI. Comparison between groups was performed by X(2) test. RESULTS: Our results show a distribution of genotypes of the V129M polymorphism in the population from Castilla y León which is similar to other Spanish and European populations. CONCLUSIONS: From the genetic point of view, the risk of people from Castilla y León to suffer vCJD should be similar to that of the other Spanish regions.
Assuntos
Síndrome de Creutzfeldt-Jakob/genética , Polimorfismo Genético , Príons/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Europa (Continente) , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Proteínas Priônicas , EspanhaRESUMO
OBJECTIVE: The transgenic mouse line MEnTCD2.5 expresses a dominant interfering Myb protein in a T-cell-specific fashion. When MEnTCD2.5 animals are crossed to a second line ubiquitously expressing Myc, they develop a rapid onset, fatal disease characterized by enlarged lymph nodes full of nonlymphoid cells. This study aimed to elucidate the reason for this anomalous non-T-cell phenotype. MATERIALS AND METHODS: We studied the cells by morphological analysis, surface marker staining, mRNA expression studies and in vitro colony-forming assays. RESULTS: Aberrant cells in MEnTCD2.5 lymph nodes are erythroblasts, and cooperation between MEnTCD2.5 and Myc causes severe erythroblastosis, but not erythroleukemia. MEnTCD2.5:Myc and MEnTCD2.5 animals have pronounced extramedullary erythropoiesis in their lymph nodes, and some increase in bone marrow-derived erythroid progenitors; no other MEnTCD2 transgenic line cooperates in this fashion with Myc, suggesting that the MEnTCD2.5 integration site, in intron 2 of the Lrfn2 gene, is of importance. To confirm this, in in vitro colony-forming assays, expression of wild-type Lrfn2 phenocopies the MEnTCD2.5 defect. Finally, Lrfn2 expression also causes the outgrowth of a bizarre cell type in colony-forming assays that stains positively for both early hematopoietic and fibroblast/fibrocyte surface markers. CONCLUSIONS: The Lrfn2 protein, a transmembrane adhesion-type molecule, is able to subvert hematopoietic differentiation to increase erythropoiesis. In cooperation with Myc, this leads to erythroblastosis. Lrfn2 may also be involved in colony forming units-fibroblast regulation. As Lrfn2 expression is detectable in wild-type bone marrow, it likely plays a novel role during normal hematopoiesis.
Assuntos
Eritropoese/fisiologia , Glicoproteínas de Membrana/fisiologia , Proteínas do Tecido Nervoso/fisiologia , Animais , Diferenciação Celular , Células Cultivadas , Clonagem Molecular , Ensaio de Unidades Formadoras de Colônias , Eritroblastos/citologia , Eritropoese/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Glicoproteínas de Membrana/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos , Camundongos Nus , Camundongos Transgênicos , Proteínas do Tecido Nervoso/genética , Fenótipo , Proteínas Proto-Oncogênicas c-myc/genética , RNA Mensageiro/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodosRESUMO
Introducción: la detección oportuna y la evaluación de las reacciones adversas de los medicamentos es cada vez más importante. En Cuba existe la necesidad de profundizar y extender con alcance nacional los estudios de Farmacovigilancia, por tal motivo se expone como objetivo fundamentar sustentados en la estadística el uso de estudios de farmacovigilancia para la detección, registro, notificación y evaluación de las sospechas de las reacciones adversas de los medicamentos valorando su seguridad. Desarrollo: se brinda un resumen de tipos de estudios de farmacovigilancia con ejemplos de objetivos de investigaciones realizadas y publicadas en revistas científicas posibles a considerar y aplicar a las condiciones reales que tenga cada investigador, se presentan variables que ya han sido establecidas en otros estudios que se deben tener en cuenta para estudiar seguridad de los medicamentos y técnicas estadísticas teniendo en cuenta los tipos de variables a relacionar. Conclusiones: se concluye que resulta un logro científico conocer formas de profundizar y extender los estudios de Farmacovigilancia para tomar conocimiento de la seguridad de los fármacos y promover un uso racional, científico y adecuado de los mismos, en beneficio de la comunidad.
Introduction: timely detection and evaluation of adverse drug reactions is increasingly important. In Cuba there is a need to deepen and extend pharmacovigilance studies nationwide. That is why it is stated, based on statistics, the use of studies for the detection, registration, notification and evaluation of suspected adverse drug events, assessing their safety. Development: a summary of types of pharmacovigilance studies is provided with examples of objectives of research works already done and published in scientific magazines likely to consider and use in actual conditions each researcher has, and there are also presented variables that have already been established in other studies, which must be taken into account to study drug safety and statistical techniques considering the types of variables to be related. Conclusion: it is concluded that knowing ways to deepen and spread the Pharmacovigilance studies in order to be aware of drug safety and foster their rational, scientific and adequate use in the interests of the community is indeed a scientific accomplishment.
Introdução: a detecção e avaliação oportunas de reações adversas a medicamentos está se tornando cada vez mais importante. Em Cuba há uma necessida de de aprofundar e ampliar os estudos de farmacovigilância com âmbito nacional, por esta razão é declarado como um objetivo fundamentar com base em estatísticas o uso de estudos de farmacovigilância para a detecção, registro, notificação e avaliação de suspeitas de reações adversas de medicamentos que avaliam sua segurança. Desenvolvimento: um resumo dos tipos de estudos de farmacovigilância é fornecido com exemplos de objetivos de pesquisa realizados e publicados em possíveis revistas científicas a serem consideradas e aplicadas às condições reais que cada pesquisador possui, variáveis que já foram estabelecidas em outros estudos que devem ser levadas em conta para estudar a segurança de medicamentos e técnicas estatísticas levando em conta os tipos de variáveis a serem relacionadas. Conclusões: conclui-se que é uma conquista científica conhecer formas de aprofundar e ampliar os estudos de farmacovigilância para tomar conhecimento da segurança dos medicamentos e promover um uso racional, científico e adequado dos mesmos, em benefício da comunidade.
RESUMO
Mutations in, and the altered expression of, epigenetic modifiers are pervasive in human tumours, making epigenetic factors attractive antitumour targets. The open-versus-closed chromatin state within the cells-of-origin of cancer correlates with the uneven distribution of mutations. However, the long-term effect of targeting epigenetic modifiers on mutability in patients with cancer is unclear. Here, we increased chromatin accessibility by deleting the histone H3 lysine 9 (H3K9) methyltransferase G9a in murine epidermis and show that this does not alter the single nucleotide variant burden or global genomic distribution in chemical mutagen-induced squamous tumours. G9a-depleted tumours develop after a prolonged latency compared with their wild-type counterparts, but are more aggressive and have an expanded cancer progenitor pool, pronounced genomic instability and frequent loss-of-function p53 mutations. Thus, we call for caution when assessing long-term therapeutic benefits of chromatin modifier inhibitors, which may promote more aggressive disease.
Assuntos
Cromatina/genética , Instabilidade Genômica , Histona-Lisina N-Metiltransferase/genética , Mutação , Neoplasias Cutâneas/genética , Animais , Linhagem Celular , Cromatina/metabolismo , Epiderme/metabolismo , Epiderme/patologia , Epigênese Genética , Histona-Lisina N-Metiltransferase/metabolismo , Humanos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Invasividade Neoplásica , Neoplasias Cutâneas/metabolismo , Neoplasias Cutâneas/patologia , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismoRESUMO
El ciclo del nitrógeno representa uno de los procesos biogeoquímicos más importantes para los ecosistemas terrestres y acuáticos. Las comunidades microbianas desempeñan un papel crucial en los procesos de transformación del nitrógeno en el suelo, ya que participan en diversas etapas como la nitrificación, de gran importancia para la producción agrícola. Dentro de los marcadores moleculares más utilizados para evaluar la actividad de poblaciones microbianas oxidantes de amonio se han considerado ampliamente los genes que codifican enzimas claves como la subunidad A de la actividad amonio monooxigenasa (AMO). Sin embargo, no se comprende completamente si la expresión de esta enzima tiene relación directa con el rendimiento de los cultivos. En este contexto, se evaluó la expresión del gen amo-A de comunidades bacterianas y archaeales presentes en un lote arrocero previamente caracterizado por ambientes. Para cuantificar la abundancia de arqueas y bacterias oxidantes de amonio, (AOA y AOB, respectivamente) se emplearon las técnicas de PCR en tiempo real (RT-qPCR) y PCR digital (RT-dPCR). En este trabajo se encontró a través del análisis de datos metagenómicos que hubo una mayor presencia de AOB en las muestras de suelo rizosférico mientras que las AOA fueron predominantes en las muestras de suelo de soporte "bulk", sin embargo, no se detectó la expresión del gen amo-A asociada a la comunidad de bacterias en las muestras de suelo analizadas. Por otra parte, no se presentaron diferencias entre los transcritos del gen amo-A asociados a la comunidad de AOA de los ambientes caracterizados. Además, la expresión de transcritos no estuvo relacionada con alguna de las propiedades químicas evaluadas. Finalmente, las estrategias de cuantificación para RT-qPCR (plásmido y templete) resultaron ser homólogas y funcionales para identificar la expresión del gen amo-A de AOA, mientras que la técnica de RT-dPCR fue más precisa para el análisis de la comunidad de AOB y AOA.
The nitrogen cycle represents one the most important biogeochemical process for terrestrial and aquatic ecosystems. Microbial communities play a crucial role in the processes of transformation of soil nitrogen in the, since they participate in various stages such as nitrification, which is of great importance for agricultural production. Among the most used molecular markers to assess ammonium oxidizing microbial populations activity have been considered widely the genes encoding key enzymes such as ammonium monooxygenase (AMO) subunit A. However, it is not fully understood whether the expression of this enzyme is directly related to the crop yield. In this context, this research work evaluated the expression of the amo-A gene of bacterial and archaeal communities present in a rice field previously characterized by environments. Real-time PCR (RT-qPCR) and digital PCR (RT-dPCR) techniques were used to quantify the abundance of archaea and ammonium-oxidizing bacteria (AOA and AOB, respectively). In this work it was found that in the analysis of metagenomic data there was a greater presence of AOB in rhizospheric soil samples while AOA were predominant in bulk soil samples, however, the expression of the amo-A gene was not detected. associated with the community of bacteria in the soil samples analyzed. On the other hand, it was found that the transcripts of the amo-A gene of the AOA community did not present differences between the characterized environments. Furthermore, the expression of transcripts is not related to any of the chemical properties evaluated. Finally, the quantification strategies for RT-qPCR (plasmid and quenching) turned out to be homologous and functional to identify the expression of the AOA amo-A gene, while the RT-dPCR technique was more precise for the analysis of the community of AOB and AOA.
RESUMO
BACKGROUND: Using functional near infrared spectroscopy, a noninvasive, optical brain imaging tool that monitors changes in hemodynamics within the prefrontal cortex (PFC), we assessed performance and cognitive effort during the acquisition, retention and transfer of multiple simulated laparoscopic tasks by novice learners within a contextual interference paradigm. METHODS: Third-year medical students (n = 10) were randomized to either a blocked or random practice schedule. Across 3 days, students performed 108 acquisition trials of 3 laparoscopic tasks on the LapSim® simulator followed by delayed retention and transfer tests. Performance metrics (Global score, Total time) and hemodynamic responses (total hemoglobin (µm)) were assessed during skill acquisition, retention and transfer. RESULTS: All acquisition tasks resulted in significant practice schedule X trial block interactions for the left medial anterior PFC. During retention and transfer, random performed the skills in less time and had lower total hemoglobin change in the right dorsolateral PFC than blocked. CONCLUSIONS: Compared with blocked, random practice resulted in enhanced learning through better performance and less cognitive load for retention and transfer of simulated laparoscopic tasks.
Assuntos
Avaliação Educacional/métodos , Laparoscopia/educação , Córtex Pré-Frontal/diagnóstico por imagem , Treinamento por Simulação , Espectroscopia de Luz Próxima ao Infravermelho , Hemoglobinas/análise , Humanos , Aprendizagem , Distribuição Aleatória , Retenção PsicológicaRESUMO
BACKGROUND: We describe initial success in designing and implementing an objective evaluation for opening and closing a simulated abdomen. METHODS: (1) An assessment for laparotomy was created using peer-reviewed literature, texts, and the input of academic surgeons nationally; (2) the assessment was evaluated for construct validity, comparing the videotaped performance of laparotomy by surgical experts and novices on a viscoelastic model; and (3) the basics of open laparotomy training (BOLT) curriculum was piloted with junior residents to evaluate efficacy at improving performance. RESULTS: Experts performed better than novices opening (.94 vs .51; P < .001), closing (.85 vs .16; P < .001), and overall performance (.88 vs .27; P < .001). Novices caused bowel injury more frequently (5 vs 1; P < .05) and took longer to open the abdomen (6:06 vs 3:43; P = .01). After completing the BOLT curriculum, novices improved for opening (1.00 vs .50; P = .014), closing (.80 vs .10; P = .014), and overall score (.87 vs .23; P = .014). CONCLUSIONS: We demonstrate construct validity of an evaluation tool for simulated laparotomy, and pilot efforts with the BOLT curriculum have shown promise.
Assuntos
Competência Clínica , Currículo , Avaliação Educacional , Laparotomia/educação , Treinamento por Simulação , Abdome/cirurgia , Simulação por Computador , Técnica Delphi , Humanos , Internato e Residência , Projetos Piloto , Estados UnidosRESUMO
Approximately 121,000 bariatric surgical procedures are performed annually, and salutary effects include a reduction in cardiovascular morbidity and mortality, risk factor modification, and improvement in sympathovagal tone. There are anecdotal accounts of unexplained sinus bradycardia (SB) after significant weight loss but no systematic studies have been conducted. The purpose of this study was to determine the frequency of incident SB, its timing, and association with weight loss, clinical characteristics, and predictors. We evaluated various clinical characteristics including resting heart rate, blood pressure, body mass index (BMI), heart rate reserve (HRR), basal metabolic rate, and exercise regimen in 151 consecutive patients who underwent bariatric surgery. Multiple logistic regression analysis was performed to determine predictors of SB. Twenty-five of 137 patients (18%) experienced postoperative SB. Patients with SB had significantly greater reduction in BMI than those without bradycardia (35 ± 9.6% and 25.7 ± 13%, respectively, p = 0.002). HRR was significantly greater in patients with SB (116 ± 14 beats/min) compared with those without bradycardia (105 ± 14 beats/min, p = 0.007). Multiple logistic regression analysis revealed that the odds of developing SB were 1.96 and 1.91 and associated with the percent decrease in BMI (95% confidence interval 1.3 to 3.0, p = 0.002) or increase in HRR (95% confidence interval 1.28 to 2.85, p = 0.002), respectively. In conclusion, SB occurred 14 ± 11 months postoperatively and its predictors were the percent reduction in BMI or increase in HRR.
Assuntos
Arritmia Sinusal/etiologia , Cirurgia Bariátrica/efeitos adversos , Bradicardia/etiologia , Eletrocardiografia , Frequência Cardíaca/fisiologia , Obesidade/cirurgia , Adulto , Arritmia Sinusal/epidemiologia , Arritmia Sinusal/fisiopatologia , Pressão Sanguínea , Índice de Massa Corporal , Bradicardia/epidemiologia , Bradicardia/fisiopatologia , Feminino , Seguimentos , Humanos , Incidência , Masculino , Pennsylvania/epidemiologia , Complicações Pós-Operatórias , Período Pós-Operatório , Estudos Prospectivos , Fatores de RiscoRESUMO
Schistosomiasis is a disease with a strong genetic component influenced by socioeconomic and ecological factors. Epidemiological studies have identified several genetic regions involved in the schistosomiasis susceptibility. However, it is not well known what physiological traits are predisposing to the disease. The study of experimental infections in inbred mouse strains with variable genetic susceptibility to the disease offers a good opportunity to tackle this question. F1B6CBA hybrid between the most divergent strains was infected in order to characterize the immunophenotypes that correlate with the susceptibility of schistosomiasis disease in mice. Complete blood counts and immunophenotype were determined at 0, 3, 6, and 9 weeks post infection. Nine weeks after cercariae exposure, animals were perfused and worm recovery was assessed. A large number of hepatic lesions, a reduction in the eosinophil and basophil count in the acute phase of infection and the decreased number of monocytes, neutrophils and B-lymphocytes are phenotypes associated with increased susceptibility to S. mansoni infection.
Assuntos
Suscetibilidade a Doenças , Schistosoma mansoni/imunologia , Esquistossomose mansoni/patologia , Animais , Quimera , Feminino , Imunofenotipagem , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos CBA , Fenótipo , Esquistossomose mansoni/imunologiaRESUMO
OBJECTIVES: Laryngopharyngeal reflux (LPR) is a pervasive disorder that may cause hoarseness, throat clearing, and other symptoms. These symptoms are particularly problematic in professional voice users. Proton pump inhibitors (PPIs) are the mainstay of current medical management for LPR but may be insufficient in managing some patients' symptoms. Laparoscopic Nissen fundoplication (LNF) is well established for treatment of gastroesophageal reflux disease with a high success rate, but its role in the treatment of LPR remains uncertain. This study was designed to investigate the effectiveness of anti-reflux surgery in managing disease refractory to medical reflux therapy (twice of more per day PPIs). STUDY DESIGN: Retrospective medical record review. METHODS: This study examined 25 professional voice users, age ranging from 14 to 75 years, diagnosed with refractory LPR treated twice daily or more with PPIs. Reflux finding scores (RFS) were graded by blinded raters and compared for initial, preoperative, postoperative, and final visits. Twenty-four-hour pH-impedance study scores were obtained pre- and postoperatively. RESULTS: Sixty percent of patients were on no-reflux medications postoperatively and an additional 24% were on less medication. RFS was not significantly different between pre- and postoperative evaluations with good inter- and intrarater reliability; postoperative examinations occurred on less or no pharmaceutical reflux treatment. Twenty-four-hour pH-impedance testing revealed significant reductions in reflux and a nearly significant reduction in total acid. Ninety percent of positive symptom indices preoperatively were negative postoperatively. Seventy-six percent of patients on BID dosing of PPIs and 86% of those receiving super-high-dose PPI administration who underwent LNF were satisfied with the results for their LPR disease. CONCLUSION: LNF should be considered as a treatment option for professional voice users with LPR with symptoms refractory to standard or super-high-dose medical management. LNF may decrease or eliminate the need for postoperative PPI usage. The RFS may not be sensitive enough to monitor changes in LPR severity. Patients, especially those on super-high-dose medication administration, are satisfied with the improvement in LPR symptoms after anti-reflux surgery.