Evaluación del tratamiento con Laser Diodo 810 en Retinopatia de la Prematuridad Grave: Hospital Regional Docente de Las Mercedes 2011 - 2015

Objetivo: Evaluar la eficacia del tratamiento con láser diodo 810 en los pacientes con ROP grave en el HRDLMCH durante el periodo 2011 – 2015. Material y métodos: Estudio analítico, retrospectivo, transversal en las historias clínicas de 224 pacientes con diagnóstico de retinopatía de la prematuridad (CIE 10: H35.1). Para la evaluación de la eficacia del tratamiento se utilizó la valoración de los resultados estructurales dada por el oftalmólogo luego de la aplicación del láser. Para el análisis estadístico se usó el programa SPSS v.23.0. Para establecer la relación de las principales variables epidemiológicas con los grupos de gravedad de ROP se usaron pruebas estadísticas de relación. Para el análisis de los factores de riesgo predictivos de ROP grave su utilizó regresión logística. Resultados: La incidencia de ROP fue del 26.52%. La gravedad de ROP, se relacionó con el peso, edad gestacional al nacimiento y el número de exploraciones oftalmológicas. El 51.72% de los pacientes con ROP grave fueron mujeres, el peso al nacimiento promedio fue de 1243.76 gramos, la edad gestacional promedio fue de 30.52 semanas. La edad gestacional al nacimiento y el número de transfusiones sanguíneas son factores predictivos de ROP grave. La valoración del resultado estructural fue favorable en el 100%, los resultados funcionales presentaron una valoración adecuada en el 91.39 % y se presentó complicaciones en el 5.17% de los ojos tratados. Conclusión: El tratamiento con láser diodo 810 en los pacientes con ROP grave fue eficaz

The GacS/A-RsmA Signal Transduction Pathway Controls the Synthesis of Alkylresorcinol Lipids that Replace Membrane Phospholipids during Encystment of <i>Azotobacter vinelandii</i> SW136

<div><p><i>Azotobacter vinelandii</i> is a soil bacterium that undergoes a differentiation process that forms cysts resistant to desiccation. During encystment, a family of alkylresorcinols lipids (ARs) are synthesized and become part of the membrane and are also components of the outer layer covering the cyst, where they play a structural role. The synthesis of ARs in <i>A</i>. <i>vinelandii</i> has been shown to occur by the activity of enzymes encoded in the <i>arsABCD</i> operon. The expression of this operon is activated by ArpR, a LysR-type transcriptional regulator whose transcription occurs during encystment and is dependent on the alternative sigma factor RpoS. In this study, we show that the two component response regulator GacA, the small RNA RsmZ1 and the translational repressor protein RsmA, implicated in the control of the synthesis of other cysts components (i.e., alginate and poly-ß-hydroxybutyrate), are also controlling alkylresorcinol synthesis. This control affects the expression of <i>arsABCD</i> and is exerted through the regulation of <i>arpR</i> expression. We show that RsmA negatively regulates <i>arpR</i> expression by binding its mRNA, repressing its translation. GacA in turn, positively regulates <i>arpR</i> expression through the activation of transcription of RsmZ1, that binds RsmA, counteracting its repressor activity. This regulatory cascade is independent of RpoS. We also show evidence suggesting that GacA exerts an additional regulation on <i>arsABCD</i> expression through an ArpR independent route.</p></div

Effect of different gene inactivations on <i>arsA</i> gene expression measured by RT-qPCR.

<p>The level of the <i>arsA</i> transcripts was measured under encystment inducing conditions and it was normalized according to the level of the <i>gyrA</i> mRNA. The data are presented as fold change of <i>arsA</i> mRNA levels in mutants with <i>gacA</i>, <i>rsmZ1</i>, <i>rsmA</i>, and <i>gacA</i>-<i>rsmA</i> gene inactivations (strains SW5, SW13, SW11 and SW15), relative to those of the wild type strain (SW136). Determinations were made from bacterial cultures grown for 36 h in liquid BBOH medium at 30°C. The data represent the mean of triplicates and the error bars represent standard deviations. Asterisks indicate statistical significance (unpaired Student's <i>t</i>-test) in the comparison of each mutant versus the wild type strain, *P < 0.05.</p

Proposed model for the control of ARs synthesis by the Gac-Rsm system in <i>A</i>. <i>vinelandii</i> SW136.

<p>The regulatory protein GacA controls ARs synthesis by two different pathways, one dependent on the Rsm system, that regulates the expression of the transcriptional activator ArpR, and a second pathway that positively controls expression of the <i>ars</i> biosynthetic genes independently of these regulators. Dashed lines indicate unknown intermediates or unknown mechanism of regulation.</p

Effect of different gene inactivations on <i>arpR</i> gene expression measured by RT-qPCR.

<p>The level of the <i>arpR</i> transcripts was measured under encystment inducing conditions and it was normalized according to the level of the <i>gyrA</i> mRNA. The data are presented as fold change of <i>arpR</i> mRNA levels in mutants with <i>gacA</i>, <i>rsmZ1</i>, <i>rsmA</i>, and <i>gacA</i>-<i>rsmA</i> gene inactivations (strains SW5, SW13, SW11 and SW15), relative to those of the wild type strain (SW136). Determinations were made from bacterial cultures grown for 36 h in liquid BBOH medium at 30°C. The data represent the mean of triplicates and the error bars represent standard deviations. Asterisks indicate statistical significance (unpaired Student's <i>t</i>-test) in the comparison of each mutant versus the wild type strain, *P < 0.05.</p

Effect of ArpR constitutive expression and acetoacetyl-CoA coinducer addition on ARs production of the mutant strains.

<p><b>(A)</b> Staining with Fast Blue B of alkylresorcinols produced by colonies of <i>A</i>. <i>vinelandii</i> SW 136 wild type strain and its mutant derivatives <i>gacA</i>, <i>rsmZ1</i>, <i>rsmA and gacA-rsmA</i>. All strains were transformed with plasmid pBBR-ArpR, carrying a constitutively expressed <i>arpR</i> gene. The colonies were grown on Petri dishes under encystment inducing conditions for 5 days. <b>(B)</b> Quantification of the ARs produced by the same strains also expressing ArpR from plasmid pBBR-ArpR, under the same conditions shown in (A) Asterisks indicate statistical significance (unpaired Student's <i>t</i>-test) in the comparison of ARs content of each mutant versus the wild type strain, *P < 0.05. (C) Effect of the addition to the medium of acetoacetyl-CoA, the coinducer of ArpR, on ARs production visualized by staining with Fast Blue B. The colonies were grown on Petri dishes under vegetative conditions for 5 days in the absence or presence of 5 μM acetoacetyl-CoA. The stains were also transformed with plasmid pBBR-ArpR.</p

Production of ARs by different <i>A</i>. <i>vinelandii</i> mutants.

<p>(<b>A</b>) Staining with Fast Blue B of the ARs produced by colonies of <i>A</i>. <i>vinelandii</i> strain SW136 (Wild type), and its mutant derivatives inactivated in the genes <i>gacA</i>, <i>rsmZ1</i>, <i>rsmA</i> (strains SW5, SW13 and SW11) and the double mutant <i>gacA</i>-<i>rsmA</i> (SW15). The colonies were grown on Burk-Butanol (encystment induction medium) for 5 days prior to staining. (<b>B</b>). Quantification of the ARs produced by the mutants under the same conditions. The data represent the mean of triplicates and the error bars represent the standard deviations. Asterisks indicate statistical significance (unpaired Student's <i>t</i>-test) in the comparison of each mutant versus the wild type strain, *P < 0.05.</p

Effect of <i>gacA</i>, <i>rsmZ1</i>, <i>rsmA</i> gene inactivations on the expression of the ARs biosynthetic gene <i>arsA</i> and its regulatory gene <i>arpR</i> measured using chromosomal transcriptional and translational gene fusions.

<p>Expression levels of <i>arsA</i> (<b>A</b>) and <i>arpR</i> (<b>B</b>) were quantified as ß-glucuronidase activity of strains carrying <i>arsA</i>::<i>gusA</i> and <i>arpR</i>::<i>gusA</i> transcriptional (black bars) and translational (grey bars) gene fusions. The strains used for <i>arsA</i> gene expression determinations were YRR30, YRR36, YRR40 and YRR38 (Wild type and its <i>gacA</i>, <i>rsmZ1</i> and <i>rsmA</i> mutant derivatives containing an <i>arsA</i>::<i>gusA</i> <b>transcriptional</b> gene fusion respectively); and YRR31, YRR33, YRR41, YRR39 (Wild type and its <i>gacA</i>, <i>rsmZ1</i> and <i>rsmA</i> mutant derivatives containing an <i>arsA</i>::<i>gusA</i> <b>translational</b> gene fusion). For <i>arpR</i>, the strains were YRR50, YRR54, YRR58, and YRR56 (Wild type and its <i>gacA</i>, <i>rsmZ1</i> and <i>rsmA</i> mutant derivatives containing an <i>arpR</i>::<i>gusA</i> <b>transcriptional</b> gene fusion respectively); YRR51, YRR53, YRR59 and YRR57 (Wild type and its <i>gacA</i>, <i>rsmZ1</i> and <i>rsmA</i> mutant derivatives containing the <i>arpR</i>::<i>gusA</i> <b>translational</b> gene fusion). One unit of ß-glucuronidase corresponds to 1 nmol of substrate (X-Gluc) hydrolyzed min^-1 mg Protein^-1. Determinations in both panels were made from bacterial cultures grown for 36 h in liquid BBOH medium at 30°C. Error bars represent standard deviations. Asterisks indicate statistical significance (unpaired Student's <i>t</i>-test) in the comparison of each mutant versus the corresponding wild type strain with the same gene fusion, *P < 0.05.</p

1,2â Diacylglycerol choline phosphotransferase catalyzes the final step in the unique Treponema denticola phosphatidylcholine biosynthesis pathway

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/136290/1/mmi13596.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136290/2/mmi13596-sup-0001-suppinfo01.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136290/3/mmi13596_am.pd