RESUMO
BACKGROUND: Tellurium is a rare metalloid that exerts high toxicity on cells, especially on bacteria, partly due to reactive oxygen species (ROS) generation. Moreover, it has also been observed that tellurite can target free cell thiols groups (RSH) (i.e. reduced glutathione (GSH)), enhancing the cellular redox imbalance. Additionally, in vitro experiments have suggested that several enzymes can reduce tellurite (IV) to its elemental form (0); where RSH present on their active sites may be responsible for the process. Nevertheless, the mechanisms implemented by bacteria for tellurite reduction and its role in resistance have not been evaluated in vivo. RESULTS: This work shows that tellurite reduction to elemental tellurium is increased under anaerobic conditions in E. coli cells. The in vivo tellurite reduction is related to the intracellular concentration of total RSH, in the presence and absence of oxygen. This metabolization of tellurite directly contributes to the resistance of the bacteria to the oxyanion. CONCLUSIONS: We demonstrated that in vivo tellurite reduction is related to the intracellular thiol concentration, i.e. large availability of cellular RSH groups, results in a more significant reduction of tellurite. Furthermore, we observed that, when the bacterium exhibits less resistance to the oxyanion, a decreased tellurite reduction was seen, affecting the growth fitness. Together, these results let us propose that tellurite reduction and the intracellular RSH content are related to the oxyanion bacterial resistance, this tripartite mechanism in an oxygen-independent anaerobic process.
Assuntos
Escherichia coli , Telúrio , Anaerobiose , OxirreduçãoRESUMO
BACKGROUND: Tellurium is a rare metalloid that exerts high toxicity on cells, especially on bacteria, partly due to reactive oxygen species (ROS) generation. Moreover, it has also been observed that tellurite can target free cell thiols groups (RSH) (i.e. reduced glutathione (GSH)), enhancing the cellular redox imbalance. Additionally, in vitro experiments have suggested that several enzymes can reduce tellurite (IV) to its elemental form (0); where RSH present on their active sites may be responsible for the process. Nevertheless, the mechanisms implemented by bacteria for tellurite reduction and its role in resistance have not been evaluated in vivo. RESULTS: This work shows that tellurite reduction to elemental tellurium is increased under anaerobic conditions in E. coli cells. The in vivo tellurite reduction is related to the intracellular concentration of total RSH, in the presence and absence of oxygen. This metabolization of tellurite directly contributes to the resistance of the bacteria to the oxyanion. CONCLUSIONS: We demonstrated that in vivo tellurite reduction is related to the intracellular thiol concentration, i.e. large availability of cellular RSH groups, results in a more significant reduction of tellurite. Furthermore, we observed that, when the bacterium exhibits less resistance to the oxyanion, a decreased tellurite reduction was seen, affecting the growth fitness. Together, these results let us propose that tellurite reduction and the intracellular RSH content are related to the oxyanion bacterial resistance, this tripartite mechanism in an oxygen independent anaerobic process.
Assuntos
Telúrio , Escherichia coli , Oxirredução , AnaerobioseRESUMO
Mating has profound physiological and behavioural consequences for female insects. During copulation, female insects typically receive not only sperm, but a complex ejaculate containing hundreds of proteins and other molecules from male reproductive tissues, primarily the reproductive accessory glands. The post-mating phenotypes affected by male accessory gland (MAG) proteins include egg development, attraction to oviposition hosts, mating, attractiveness, sperm storage, feeding and lifespan. In the Mexican fruit fly, Anastrepha ludens, mating increases egg production and the latency to remating. However, previous studies have not found a clear relationship between injection of MAG products and oviposition or remating inhibition in this species. We used RNA-seq to study gene expression in mated, unmated and MAG-injected females to understand the potential mating- and MAG-regulated genes and pathways in A. ludens. Both mating and MAG-injection regulated transcripts and pathways related to egg development. Other transcripts regulated by mating included those with orthologs predicted to be involved in immune response, musculature and chemosensory perception, whereas those regulated by MAG-injection were predicted to be involved in translational control, sugar regulation, diet detoxification and lifespan determination. These results suggest new phenotypes that may be influenced by seminal fluid molecules in A. ludens. Understanding these influences is critical for developing novel tools to manage A. ludens.
Assuntos
Expressão Gênica , Comportamento Sexual Animal , Tephritidae , Animais , Copulação , Feminino , Masculino , Oviposição , Reprodução , Tephritidae/genéticaRESUMO
BACKGROUND: Descriptions of cutaneous findings associated with COVID-19 have not been consistently accompanied by histopathology or confirmatory testing for SARS-CoV-2. OBJECTIVE: To describe and classify the cutaneous findings with supporting histopathology of confirmed COVID-19 inpatients. METHODS: We included consecutive inpatients with a confirmed diagnosis of COVID-19 for whom a dermatology consult was requested. A skin biopsy was performed in all cases. Skin findings were classified as being compatible with a cutaneous manifestation of COVID-19 or as representing a distinct clinical entity. RESULTS: Twenty-eight patients were studied in whom thirty-one dermatologic diagnoses were made. Twenty-two of the dermatoses were compatible with a cutaneous manifestation of COVID-19; nine entities were not associated with infection by SARS-CoV-2. The most common COVID-19-associated pattern was an exanthematous presentation. In four patients, a new pattern was observed, characterized by discrete papules with varied histopathological findings including a case of neutrophilic eccrine hidradenitis. No cases of pernio-like lesions were identified. Skin findings not associated with COVID-19 represented 29% of diagnoses and included Malassezia folliculitis, tinea, miliaria and contact dermatitis. LIMITATIONS: There is no gold-standard test to distinguish between viral exanthems and drug reactions. CONCLUSION: A histopathological study is critical before attributing skin findings to a manifestation of COVID-19.
Assuntos
COVID-19 , Pérnio , Dermatopatias , Humanos , SARS-CoV-2 , PeleRESUMO
A severe mandibular hypoplasia and microstomy with intraoral anomalies including hypoglossia, fused gums, persistence of buccopharyngeal membrane, and laryngeal hypoplasia were noted in a female newborn with the dysgnathia complex (DC). Additionally, our proposita also presented natal teeth as a probably new finding. These clinical manifestations overlapped with those of the fourth report of hypomandibular faciocranial syndrome (HFS) (31), and given that both lack for craniosynostosis (pathognomonic of HFS), we considered that both represent a subtype of DC proposed as DC sine holoprosencephaly nor synotia (DCSHS). Differential characteristics between the DCSHS, the HFS, and the DC with holoprosencephaly sine synotia are reviewed and additionally, we discussed some aspects about the nosology of the DC.
Assuntos
Anormalidades Múltiplas/diagnóstico , Holoprosencefalia/diagnóstico , Anormalidades Maxilomandibulares/diagnóstico , Craniossinostoses/complicações , Craniossinostoses/diagnóstico , Evolução Fatal , Feminino , Cabeça/diagnóstico por imagem , Holoprosencefalia/complicações , Humanos , Imageamento Tridimensional , Recém-Nascido , Anormalidades Maxilomandibulares/complicações , Mandíbula/anormalidades , Dentes Natais , Tomografia Computadorizada por Raios X/métodosRESUMO
We report a 49-year old male with diagnosis of gastric schwannoma who underwent subtotal gastrectomy. We describe clinicopathological and immunohistochemical characteristics of these tumors and performed an extensive literature review. Gastric schwannomas are very rare tumors but they should be taken into account in the differential diagnosis of more common mesenchimal neoplasms like gastrointestinal stromal tumors (GIST). The treatment of choice is surgical resection and their prognosis is very favourable.
Assuntos
Gastrectomia , Neurilemoma/patologia , Neurilemoma/cirurgia , Neoplasias Gástricas/patologia , Neoplasias Gástricas/cirurgia , Diabetes Mellitus Tipo 2/complicações , Diagnóstico Diferencial , Humanos , Hipertensão/complicações , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , PrognósticoRESUMO
La incidencia de la Diabetes Tipo 1 ha aumentado durante los últimos decenios en todo el mundo, representando en nuestro medio la séptima causa de muerte y afectando aproximadamente a un millón de venezolanos. De acuerdo a la OMS se clasifica en: Autoinmune (tipo A y tipo B) e idiopática. Esta enfermedad se considera como el resultado de una serie de factores genéticos (asociados a la región HLA-D del MHC clase II; principalmente es el locus HLA-DQ) y ambientales (relacionados con el estilo de vida del paciente e infecciones virales principalemente en virus coxsackie) que medían la activación del sistema inmunológico del individuo provocando de esta manera la destrucción de las células beta pancreáticas por diferentes mecanismos: pérdida de la Autotolerancia, Directo "Reconocimiento de Unión" e Indirecto "Unión-Activación" y como consecuencia la aparición de las manifestaciones clínicas de la enfermedad. La DM tipo 1 cursa con un período asintomático que se caracteriza por una infiltración de los islotes por monocitos/macrófagos y células T citotóxicas activadas. Este estado en el que se encuentran el paciente mientras se está produciendo (de forma indetectable), la agregación inmunitaria se denomina PRE-DIABETES, posteriormente las reservas de insulina van disminuyendo constantemente hasta hacerse insuficientes y es cuando se manifiesta clínicamente la DM.
Assuntos
Humanos , Masculino , Adolescente , Feminino , Criança , Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 1/patologia , Microbiologia Ambiental , Ilhotas Pancreáticas/fisiopatologia , Ilhotas Pancreáticas/patologia , Antígenos HLA-D/análise , Antígenos HLA-DQ/análiseRESUMO
El presente trabajo es resultado de un reanálisis de los datos presentados anteriormente por Fernández, Jiménez & Vargas (2000) con el objetivo de cuantificar el aporte del comedor escolar a la alimentación de 11 familias de Finca San Juan de Pavas. El método usado para recolectar los datos dietéticos fue el recordatorio de 24 horas. El consumo de alimentos del niño en el comedor escolar fue medido aparte y su consumo en el hogar fue incluido en el consumo familiar. Los resultados demostraron que durante los días de semana cuando el niño va a la escuela, recibe del comedor más de una tercera parte de sus necesidades nutricionales en cuanto a energía y 10 nutrientes. Además, se encontró que la alimentación ofrecida en las escuelas tenía una concentración mayor de calcio; riboflavina; vitaminas A, C y B6 , y menor de grasa total y saturada. Se concluye que el comedor de la escuela de Finca San Juan de Rincón Grande de Pavas, contribuye de forma importante a las necesidades nutricionales y formación de hábitos alimentarlos adecuados en un grupo de niños escolares de familias de bajos recursos.