Chitosan-Coated Silver Nanoparticles Inhibit Adherence and Biofilm Formation of Uropathogenic Escherichia coli.

Urinary tract infections are commonly caused by uropathogenic Escherichia coli (UPEC), which usually presents multiple virulence and resistance mechanisms, making it difficult to treat. It has been demonstrated that silver and polymeric nanoparticles had potential against these pathogens. In this study, we synthesized thiol chitosan-coated silver nanoparticles (SH-Cs-AgNPs) and evaluated their antibacterial, antibiofilm and antiadherence activity against clinical isolates of UPEC. The SH-Cs-AgNPs showed a spherical shape with a size of 17.80 ± 2.67 nm and zeta potential of 18 ± 2 mV. We observed a potent antibacterial and antibiofilm activity as low as 12.5 µg/mL, as well as a reduction in the adherence of UPEC to mammalian cells at concentrations of 1.06 and 0.53 µg/mL. These findings demonstrate that SH-Cs-AgNPs have potential as a new therapeutic compound against infections caused by UPEC.

Biosynthesis of Silver Nanoparticles Using Seasonal Samples of Sonoran Desert Propolis: Evaluation of Its Antibacterial Activity against Clinical Isolates of Multi-Drug Resistant Bacteria.

Multi-drug resistant (MDR) bacteria have gained importance as a health problem worldwide, and novel antibacterial agents are needed to combat them. Silver nanoparticles (AgNPs) have been studied as a potent antimicrobial agent, capable of countering MDR bacteria; nevertheless, their conventional synthesis methods can produce cytotoxicity and environmental hazards. Biosynthesis of silver nanoparticles has emerged as an alternative to reduce the cytotoxic and environmental problems derived from their chemical synthesis, using natural products as a reducing and stabilizing agent. Sonoran Desert propolis (SP) is a poplar-type propolis rich in polyphenolic compounds with remarkable biological activities, such as being antioxidant, antiproliferative, and antimicrobial, and is a suitable candidate for synthesis of AgNPs. In this study, we synthesized AgNPs using SP methanolic extract (SP-AgNPs) and evaluated the reduction capacity of their seasonal samples and main chemical constituents. Their cytotoxicity against mammalian cell lines and antibacterial activity against multi-drug resistant bacteria were assessed. Quercetin and galangin showed the best-reduction capacity for synthesizing AgNPs, as well as the seasonal sample from winter (SPw-AgNPs). The SPw-AgNPs had a mean size of around 16.5 ± 5.3 nm, were stable in different culture media, and the presence of propolis constituents was confirmed by FT-IR and HPLC assays. The SPw-AgNPs were non-cytotoxic to ARPE-19 and HeLa cell lines and presented remarkable antibacterial and antibiofilm activity against multi-drug resistant clinical isolates, with E. coli 34 and ATCC 25922 being the most susceptible (MBC = 25 µg/mL), followed by E. coli 2, 29, 37 and PNG (MBC = 50 µg/mL), and finally E. coli 37 and S. aureus ATCC 25923 (MBC = 100 µg/mL). These results demonstrated the efficacy of SP as a reducing and stabilizing agent for synthesis of AgNPs and their capacity as an antibacterial agent.

Specificity and Reactivity of Mycobacterium tuberculosis Serine/Threonine Kinases PknG and PknB.

Mycobacterium tuberculosis (Mtb), the causative agent of Tuberculosis, has 11 eukaryotic-like serine/threonine protein kinases, which play essential roles in cell growth, signal transduction, and pathogenesis. Protein kinase G (PknG) regulates the carbon and nitrogen metabolism by phosphorylation of the glycogen accumulation regulator (GarA) protein at Thr21. Protein kinase B (PknB) is involved in cell wall synthesis and cell shape, as well as phosphorylates GarA but at Thr22. While PknG seems to be constitutively activated and recognition of GarA requires phosphorylation in its unstructured tail, PknB activation is triggered by phosphorylation of its activation loop, which allows binding of the forkhead-associated domain of GarA. In the present work, we used molecular dynamics and quantum-mechanics/molecular mechanics simulations of the catalytically competent complex and kinase activity assays to understand PknG/PknB specificity and reactivity toward GarA. Two hydrophobic residues in GarA, Val24 and Phe25, seem essential for PknG binding and allow specificity for Thr21 phosphorylation. On the other hand, phosphorylated residues in PknB bind Arg26 in GarA and regulate its specificity for Thr22. We also provide a detailed analysis of the free energy profile for the phospho-transfer reaction and show why PknG has a constitutively active conformation not requiring priming phosphorylation in contrast to PknB. Our results provide new insights into these two key enzymes relevant for Mtb and the mechanisms of serine/threonine phosphorylation in bacteria.

[Multidisciplinary management with neuromuscular electrical stimulation therapy in a Goldenhar syndrome patient who presented swallowing disorder and failure to thrive.] / Manejo multidisciplinario con terapia de electroestimulación en un paciente con síndrome de Goldenhar, trastorno de la deglución y falla para crecer.

INTRODUCCIÓN: El síndrome de Goldenhar es un trastorno heterogéneo, esporádico en su mayoría o por patrón de herencia autosómico dominante o recesivo, de la morfogénesis craneofacial asociada al primero y segundo arcos faríngeos, y forma parte del espectro oculoauriculovertebral. La incidencia es de 1 por cada 3500-45,000 recién nacidos vivos, con una razón de sexo masculino/femenino de 3:2. CASO CLÍNICO: Se presenta el caso de un recién nacido con fenotipo de síndrome oculoauriculovertebral. Se abordó con radiografía de tórax, ecografía abdominal y tamizaje metabólico y auditivo, que reportaron hemivértebra torácica, fusión costal, quiste renal e hipoacusia bilateral profunda, respectivamente. Fue alimentado con lactancia mixta desde el nacimiento, sin lograr una succión adecuada y con pérdida de peso. A los 3 meses de edad recibió terapia de rehabilitación oral con electroestimulación en conjunto de 10 sesiones con 10 mA de intensidad, al igual que a los 23, 24, 25, 27, 30 y 32 meses de edad. A los 4 meses, espesamiento de fórmula con cereal; a los 7 meses, sonda de gastrostomía; a los 20 meses, cirugía de paladar y macrostomía. Mostró mejoría en intensidad de babeo en las primeras 10 sesiones y mejoría en la deglución a las 30 sesiones. A los 3 años de edad consume el 100% de los alimentos por vía oral. CONCLUSIONES: Con la escasa evidencia científica que este caso aislado aporta, el tratamiento con la terapia de rehabilitación en conjunto con la terapia convencional y la corrección anatómica dio resultados positivos para el trastorno de la deglución. BACKGROUND: Goldenhar syndrome is a heterogeneous disorder, mostly sporadic or due to a dominant autosomal or recessive pattern of inheritance, that exhibits craniofacial morphogenesis associated with the first and second pharyngeal arches and is part of the oculoauriculovertebral spectrum. Its incidence is of 1 in 3,500-45,000 live newborns, with a male to female ratio of 3:2. CASE REPORT: We describe the case of a male newborn with oculoauriculovertebral syndrome phenotype. It was approached with chest X-ray, abdominal ultrasound, metabolic and hearing screening, which reported thoracic hemivertebra, costal fusion, renal cyst, and profound bilateral hypoacusis, respectively. Although the newborn was fed with mixed lactation from birth, adequate suction and with weight loss were not achieved. At 3 months of age, as well as at 23, 24, 25, 27, 30 and 32 months of age, the infant received oral rehabilitation therapy with electrostimulation in a set of 10 sessions with 10 mA intensity. At 4 months, thickening of formula with cereal; at 7 months, gastrostomy tube; at 20 months, palate surgery and macrostomy. Improvement in drooling intensity was observed during the first 10 sessions, and improvement in swallowing after 30 sessions. At 3 years of age, the patient consumes 100% of food orally. CONCLUSIONS: According to limited scientific evidence that this isolated case provides, rehabilitation therapy together with conventional therapy coupled with anatomical correction gave positive results for swallowing disorder.

Manejo multidisciplinario con terapia de electroestimulación en un paciente con síndrome de Goldenhar, trastorno de la deglución y falla para crecer / Multidisciplinary management with neuromuscular electrical stimulation therapy in a Goldenhar syndrome patient who presented swallowing disorder and failure to thrive

Resumen Introducción: El síndrome de Goldenhar es un trastorno heterogéneo, esporádico en su mayoría o por patrón de herencia autosómico dominante o recesivo, de la morfogénesis craneofacial asociada al primero y segundo arcos faríngeos, y forma parte del espectro oculoauriculovertebral. La incidencia es de 1 por cada 3500-45,000 recién nacidos vivos, con una razón de sexo masculino/femenino de 3:2. Caso clínico: Se presenta el caso de un recién nacido con fenotipo de síndrome oculoauriculovertebral. Se abordó con radiografía de tórax, ecografía abdominal y tamizaje metabólico y auditivo, que reportaron hemivértebra torácica, fusión costal, quiste renal e hipoacusia bilateral profunda, respectivamente. Fue alimentado con lactancia mixta desde el nacimiento, sin lograr una succión adecuada y con pérdida de peso. A los 3 meses de edad recibió terapia de rehabilitación oral con electroestimulación en conjunto de 10 sesiones con 10 mA de intensidad, al igual que a los 23, 24, 25, 27, 30 y 32 meses de edad. A los 4 meses, espesamiento de fórmula con cereal; a los 7 meses, sonda de gastrostomía; a los 20 meses, cirugía de paladar y macrostomía. Mostró mejoría en intensidad de babeo en las primeras 10 sesiones y mejoría en la deglución a las 30 sesiones. A los 3 años de edad consume el 100% de los alimentos por vía oral. Conclusiones: Con la escasa evidencia científica que este caso aislado aporta, el tratamiento con la terapia de rehabilitación en conjunto con la terapia convencional y la corrección anatómica dio resultados positivos para el trastorno de la deglución.

Abstract Background: Goldenhar syndrome is a heterogeneous disorder, mostly sporadic or due to a dominant autosomal or recessive pattern of inheritance, that exhibits craniofacial morphogenesis associated with the first and second pharyngeal arches and is part of the oculoauriculovertebral spectrum. Its incidence is of 1 in 3,500-45,000 live newborns, with a male to female ratio of 3:2. Case report: We describe the case of a male newborn with oculoauriculovertebral syndrome phenotype. It was approached with chest X-ray, abdominal ultrasound, metabolic and hearing screening, which reported thoracic hemivertebra, costal fusion, renal cyst, and profound bilateral hypoacusis, respectively. Although the newborn was fed with mixed lactation from birth, adequate suction and with weight loss were not achieved. At 3 months of age, as well as at 23, 24, 25, 27, 30 and 32 months of age, the infant received oral rehabilitation therapy with electrostimulation in a set of 10 sessions with 10 mA intensity. At 4 months, thickening of formula with cereal; at 7 months, gastrostomy tube; at 20 months, palate surgery and macrostomy. Improvement in drooling intensity was observed during the first 10 sessions, and improvement in swallowing after 30 sessions. At 3 years of age, the patient consumes 100% of food orally. Conclusions: According to limited scientific evidence that this isolated case provides, rehabilitation therapy together with conventional therapy coupled with anatomical correction gave positive results for swallowing disorder.

Analysis of the green turtle esophagus Chelonia mydas (Linnaeus, 1758), Testudines, Cheloniidae / Análisis del esófago de la tortuga verde Chelonia mydas (Linnaeus, 1758), Testudines, Cheloniidae

The esophagus is a muscular tube whose function is to transport food from the mouth to the stomach and basically contain the same layers as the rest of the digestive tract. The morphological knowledge of structures involved in basic physiological processes in organisms is extremely important in the acquisition of ecological and evolutionary knowledge about species. This study produces morphological information proving the structures found in the green turtle's esophagus. The animals were dissected according to the methodology used by Wyneken, allowing analysis of external and internal morphological characteristics of the esophagus. The samples were processed for microscopic analysis by light and scanning electron microscopy. It was observed that the esophagus presents thin and conical dermal papillae facing the stomach throughout the mucosa to the gastroesophageal portion, decreasing its size at the end of its extension, covered by a thick keratin layer on keratinized pavement epithelial tissue. It is concluded that the esophagus of Chelonia mydas is covered by a layer of conical keratinized dermal papillae important to exert the mechanical and protective function of the mucosa of this organ, considering that the feeding of these animals is extremely abrasive, besides serving as protection so that the food does not return.

El esófago es un tubo muscular cuya función es transportar los alimentos desde la cavidad oral hasta el estómago y, básicamente, contienen las mismas capas que el resto del tracto digestivo. El conocimiento morfológico de las estructuras involucradas en los procesos fisiológicos básicos en los organismos es extremadamente importante en la adquisición de conocimientos ecológicos y evolutivos sobre las especies. Este estudio produce información morfológica que demuestra las estructuras encontradas en el esófago de la tortuga verde. Los animales se disecaron de acuerdo con la metodología utilizada por Wyneken, lo que permitió el análisis de las características morfológicas internas y externas del esófago. Las muestras se procesaron para análisis microscópico mediante microscopía electrónica de barrido y de luz. Se observó que el esófago presenta papilas dérmicas delgadas y cónicas que se enfrentan al estómago a través de la mucosa hasta la porción gastroesofágica, disminuyendo su tamaño al final de su extensión, cubierta por una capa gruesa de queratina sobre el tejido epitelial queratinizado. Se concluye que el esófago de Chelonia mydas está cubierto por una capa de papilas dérmicas queratinizadas cónicas importantes para ejercer la función mecánica y protectora de la mucosa de este órgano, considerando que la alimentación de estos animales es extremadamente abrasiva, además de servir de protección para que la comida no sea devuelta.

Estudio comparativo del habito de ingesta etílica entre adolescentes escolares Mapuches y na Mapuches en una comunidad rural de la Región de la Araucania / Comparative study of alcoholic intake habits among Mapuche and non Mapuche school adolescents at a rural community in the Araucania Region

En la comuna de Carahue, Novena Región de la Araucaína, se realiza, en 1984, un estudio comparativo del hábito de ingesta etílica en una población de 1.440 adolescentes escolares mapuches y no mapuches, a través de una encuesta autoadministrada. En general, no se observaron diferencias significativas entre ambos grupos étnicos. Encontramos un 89,1% de mapuches y un 92,4% de no mapuches que reconocen haber ingerido algún tipo de alcohol. La edad de inicio del hábito en general fue precoz. La ingesta fue frecuentemente inducida por los padres. Se destaca que un 3,4% de mapuches y un 5,1% de no mapuches son bebedores problema y constituyen el grupo de adolescentes escolares potencialmente alcohólicos. La bebida alcohólica más consumida fue la chicha de manzana. Los autores proponen reforzar los programas de prevención de alcoholismo que ya existen en los Centros Educacionales locales, procurando hacerlos extensivos éstos al grupo familiar

Partos sin atención professional en una comunidad rural de la Novena Región de la Araucanía / Labors without professional assitance in a rural community of the IX Region of Araucania

En la comuna de Carahue, ubicada en la Novena Región de la Araucanía, ocurrieron 100 partos sin atención profesional en 1984, cifra que corresponde al 16,4% del total de partos de la comuna. De éstos se lograron estudiar 88 casos. La información se obtuvo mediante una encuesta aplicada por los autores, lográndose establecer que el grupo de mayor riesgo está constituido por las multíparas con antecedentes de partos sin atención profesional previos. Se destacó como principal causa de ocurrencia del problema, la falta de interés de las embarazadas para concurrir a la maternidad. Son generalmente las suegras o los esposos los que atienden en gran medida los partos sin atención profesional. Se encontró en los partos sin atención profesional una tasa de mortalidad neonatal de 50 por 1.000 nacidos vivos, cifra que es casi diez veces superior a la registrada en los partos con atención profesional (5,9 por 1.000). Finalmente los autores proponen un sistema de trabajo conducente a disminuir el número de partos sin atención profesional y sus complicaciones