Structure of the priming arabinosyltransferase AftA required for AG biosynthesis of Mycobacterium tuberculosis.

Arabinogalactan (AG) is an essential cell wall component in mycobacterial species, including the deadly human pathogen Mycobacterium tuberculosis. It plays a pivotal role in forming the rigid mycolyl-AG-peptidoglycan core for in vitro growth. AftA is a membrane-bound arabinosyltransferase and a key enzyme involved in AG biosynthesis which bridges the assembly of the arabinan chain to the galactan chain. It is known that AftA catalyzes the transfer of the first arabinofuranosyl residue from the donor decaprenyl-monophosphoryl-arabinose to the mature galactan chain (i.e., priming); however, the priming mechanism remains elusive. Herein, we report the cryo-EM structure of Mtb AftA. The detergent-embedded AftA assembles as a dimer with an interface maintained by both the transmembrane domain (TMD) and the soluble C-terminal domain (CTD) in the periplasm. The structure shows a conserved glycosyltransferase-C fold and two cavities converging at the active site. A metal ion participates in the interaction of TMD and CTD of each AftA molecule. Structural analyses combined with functional mutagenesis suggests a priming mechanism catalyzed by AftA in Mtb AG biosynthesis. Our data further provide a unique perspective into anti-TB drug discovery.

Afta de Bednar. La importancia de la sospecha diagnóstica / Bednar’s aphthae. The importance of diagnostic suspicion

El afta de Bednar o afta pterigoide es una úlcera oral de forma redondeada u ovalada, originada por presión mecánica. Suele ser bilateral y se localiza en el tercio posterior del paladar. Clínicamente puede pasar desapercibida o producir dolor e irritabilidad; en ocasiones también puede dificultar la alimentación de recién nacidos y lactantes. No precisa realizar pruebas complementarias. El tratamiento consiste en retirar el estímulo que las produce. Se presenta el caso de un lactante con afta de Bednar. Su diagnóstico se prolongó en el tiempo y fue estudiado por varios especialistas. Inicialmente consultó por irritabilidad y rechazo de la ingesta, con posterior apreciación de dos aftas orales. Se trata de una entidad que el pediatra debe conocer, para evitar errores de diagnóstico y la solicitud de pruebas no indicadas o derivaciones innecesarias (AU)

Bednar’s aphthae, or pterygoid aphthae, is a round or oval shaped oral ulcer caused by mechanical pressure. It is usually bilateral and it is located in the posterior third of the palate. Clinically it can be unnoticed or cause pain and irritability. Sometimes it can also make it difficult for newborns and infants to be feed. No additional tests are required. Treatment consists on removing the traumatic agent that produces them. We report a case of Bednar’s ulcer in an infant. The diagnosis lasted over time and the patient was studied by several doctors. Initially due to irritability and difficult to feed, after due to the appearance of two oral ulcers. It is an entity that paediatricians should be aware of, in order to avoid diagnostic errors and the ordering of tests that are not indicated or unnecessary referrals (AU)

Recurrent Aphthous Stomatitis. / Aftosis oral recidivante.

Recurrent aphthous stomatitis is a chronic inflammatory disease of the oral mucosa. It is characterized by painful mouth ulcers that cannot be explained by an underlying disease. Recurrent oral mucosal ulcers require a proper differential diagnosis to rule out other possible causes before recurrent aphthous stomatitis is diagnosed. The condition is common, with prevalence rates ranging from 5 to 60% in different series. Its pathogenesis is unknown, but multiple factors are considered to play a part. There are no standardized treatments for this condition and none of the treatments are curative. The goal of any treatment should be to alleviate pain, reduce the duration of ulcers, and prevent recurrence.

Efeito de pomada de própolis em orabase para tratamento de ulcerações aftosas recorrentes - um estudo piloto / Effect of orabase propolis ointment for recurrent minor aphthous treatment - a piloty study

As ulcerações aftosas recorrentes (UAR), popularmente conhecidas como aftas, acometem cerca de 20% da população e causam muito desconforto. Como sua etiologia não está bem definida, os tratamentos empregados nem sempre são eficazes. As terapias naturais são cada vez mais procuradas, dentre elas destaca-se a utilização da própolis. A própolis é um composto resinoso produzido pelas abelhas para proteção da colmeia. Inúmeros trabalhos demonstram propriedades farmacológicas da própolis. Trabalhos na área odontológica, inclusive, demonstram a utilização da própolis para tratamento das aftas na forma de solução alcóolica. Considerando que não há estudos sobre o uso de pomada de própolis para a terapêutica das lesões aftosas, o objetivo deste trabalho foi analisar o efeito de uma pomada de própolis no tratamento de aftas. Os resultados obtidos demonstraram que o uso da pomada de própolis em orabase reduziu o índice de dor e o tempo de cicatrização em casos de aftas, e ocasionou um prolongamento entre as recidivas em portadores de UAR. Esses resultados são promissores, entretanto, considerando ser um estudo preliminar, novos trabalhos nesta área devem ser realizados para solidificar a eficácia da própolis em pomada para tratamento de UAR.

The recurrent aphthous ulcers, commonly known as aphthae, affect about 20% of population and cause much discomfort when chewing, swallowing and speaking. As its etiology is not well defined the treatments employed are not always effective. The natural therapies are increasingly sought by people, among them there is the use of propolis. Propolis is a resinous compound produced by bees for protecting the hive. Numerous studies demonstrate the propolis pharmacological properties. There are works in dentistry showing the propolis use for aphthae treatment in alcoholic solution form. There are no studies about propolis ointment use for ulcers treatment. The objective of this work was to analyze the effect of a propolis ointment for aphtae treatment. The results showed that propolis ointment use reduced the pain level and the healing time in aphtae cases, and it causes a prolongation between relapses in patients with this kind of lesions. These results are promising, however, it must be considered that it is a preliminary study and further work in this area should be conducted to solidify the effectiveness of propolis ointment for treating aphthae.

Eficacia del Bórax en el tratamiento del afta bucal

La estomatitis aftosa es una entidad que se presenta con mucha frecuencia en la población de manera general. Múltiples son los tratamientos sugeridos para aliviar los síntomas que esta ocasiona. En busca de nuevas alternativas de tratamiento y teniendo en cuenta lo inocua que resulta la homeopatía se realizó un ensayo clínico terapéutico aleatorizado y controlado de fase III en 45 pacientes de cualquier edad y sexo, con afta bucal diagnosticada en el Departamento de Periodoncia de la Facultad de Estomatología del ISCM - CH, los que fueron distribuidos en tres grupos de tratamientos y tratados por el método homeopático. El medicamento seleccionado fue el Bórax a potencia 6 CH, 30 CH y 200 CH. La forma de preparación del mismo fue en gotas de una solución hidroalcohólica y la vía de administración fue sublingual. Estos pacientes fueron tratados hasta un máximo de 7 días valorando dolor y tamaño de la lesión y fueron evolucionados a las 48 horas, 4 días y 7 días, con el objetivo de evaluar la eficacia del Bórax a diferentes potencias en el tratamiento del afta bucal y comparar sus resultados. Siendo el Bórax eficaz en el tratamiento del afta bucal tanto a potencia media y alta como a potencia baja(AU)

The buccal sore is an entity that shows up with a lot of frequency in the population in a general way. Many they are the treatments suggested to alleviate the symptoms that this it causes. In search of new treatment alternatives and keeping in mind the innocuous thing that it is the homeopathy he/she was carried out a therapeutic randomized clinical test and controlled of phase III in 45 patients of any age and sex, with buccal sore diagnosed in the Department of Periodoncia of Dentistry Faculty of ISCM - CH, those that were distributed in three groups of treatments and tried by the method homeopático. The selected medication went the Borax to power 6 CH, 30 CH and 200 CH. The form of preparation of the same one was in drops of a solution hidroalcóholica and the administration road was sublingual. These patients were treated until a maximum of 7 days valuing pain and size of the lesion and they were evolved to the 48 hours, 4 days and 7 days, with the objective of to evaluate the effectiveness from the Borax to different powers in the treatment of the buccal sore and to compare their results. Being so much the effective Borax in the treatment of the buccal sore to power mediates and high as to power it lowers(AU)

Identificação do helicobacter pylori na estomatite aftosa recorrente através da imunocitoquímica / Identification of Helicobacter pylori in recurrent aphthous stomatitis by immunocytochemistry

A estomatite aftosa recorrente é uma afecção bucal comumente encontrada na população e vem sendo estudada por muitos pesquisadores para determinar a sua etiologia. Com a intenção de pesquisar a accociação do Helicobacter pylori com a EAR foram estudadas amostras coletadas por raspado de três sítios diferentes (mucosa labial inferior, fundo de vestíbulo inferior, úlcera) de 21 pacientes portadores de EAR que foram submetidos à técnica de imunocitoquímica, coloração pelos métodos Papanicolaou e Giemsa e comparados com amostras do grupo controle ... Comparando os resultados encontrados nas amostras provenientes da afta e as amostras do grupo controle, houve uma diferença significativa (p,0,001). Os resultados demonstram haver associação entre a EAR e a infecção pelo Helicobacter pylori.