Systematic review of the introduction and evaluation of magnetic augmentation of the lower oesophageal sphincter for gastro-oesophageal reflux disease.

BACKGROUND: Magnetic sphincter augmentation (MSA) is reported to be an innovative alternative to antireflux surgery for patients with gastro-oesophageal reflux disease. Although used in practice, little is known about how it has been evaluated. This study aimed to systematically summarize and appraise the reporting of MSA and its introduction into clinical practice, in the context of guidelines (such as IDEAL) for evaluating innovative surgical devices. METHODS: Systematic searches were used to identify all published studies reporting MSA insertion. Data collected included patient selection, governance arrangements, surgeon expertise, technique description and outcome reporting. RESULTS: Searches identified 587 abstracts; 39 full-text papers were included (1 RCT 5 cohort, 3 case-control, 25 case series, 5 case reports). Twenty-one followed US Food and Drug Administration eligibility criteria for MSA insertion. Twenty-six documented that ethical approval was obtained. Two reported that participating surgeons received training in MSA; 18 provided information about how MSA insertion was performed, although techniques varied between studies. Follow-up ranged from 4 weeks to 5 years; in 14 studies, it was less than 1 year. CONCLUSION: Most studies on MSA lacked information about patient selection, governance, expertise, techniques and outcomes, or varied between studies. Currently, MSA is being used despite a lack of robust evidence for its effectiveness.

ANTECEDENTES: El aumento de esfínter con un dispositivo magnético (magnetic sphincter augmentation, MSA) se ha descrito como una alternativa innovadora a la cirugía antirreflujo para pacientes con enfermedad por reflujo gastroesofágico. Aunque este procedimiento se utiliza en la práctica, se sabe poco acerca de cómo ha sido evaluado. Este estudio se propuso resumir sistemáticamente y evaluar los trabajos sobre MSA y su introducción en la práctica clínica, en el contexto de las guías (como IDEAL) para la evaluación de dispositivos quirúrgicos innovadores. MÉTODOS: Se identificaron todos los estudios publicados que describían la colocación de MSA efectuando búsquedas sistemáticas. Los datos recogidos incluían la selección de los pacientes, disposiciones de gobernanza, experiencia del cirujano, descripción técnica, y descripción de resultados. RESULTADOS: Las búsquedas identificaron 587 resúmenes, incluyéndose 39 artículos completos (5 estudios de cohortes, 3 estudios de casos y controles, 26 series de casos, 5 casos clínicos). En 21 estudios se siguieron los criterios de elegibilidad de la FDA para la colocación de MSA. En 26 estudios se confirmaba que se había obtenido la aprobación ética. Dos estudios describieron que los cirujanos participantes habían recibido formación en MSA; 18 proporcionaron información sobre cómo se realizó la colocación de MSA, aunque las técnicas variaron entre los estudios. El seguimiento oscilaba entre 4 semanas y 5 años; en 14 estudios fue inferior a un año. CONCLUSIÓN: La mayoría de los estudios sobre MSA fueron casos aislados y series de casos, sin un incremento apreciable en la calidad de la evidencia sobre MSA. La información sobre la selección de los pacientes, gobernanza, experiencia, técnicas, y resultados estaba ausente o variaba entre los estudios, haciendo difíciles las comparaciones. En la actualidad, MSA se utiliza a pesar de la falta de evidencia robusta sobre su efectividad.

Steroid hormone regulation of ribosomal RNA in rat hypothalamus: early detection using in situ hybridization and precursor-product ribosomal DNA probes.

In the female rat, behavioral and endocrine aspects of reproduction are controlled, in part, by the action of the steroid hormone estradiol on several regions of the brain, including the ventrolateral portion of the ventromedial hypothalamus (VL-VMN) and the arcuate nucleus of the hypothalamus (ARC). Quantitative assessment of the effects of estradiol on the regulation of ribosomal RNA in rat hypothalamus was accomplished in this study by tandem in situ hybridization experiments with 2 ribosomal DNA probes specific to the initial transcript (precursor) or mature, stable (product) rRNA. This novel approach allowed the regulation of RNA processing by steroid hormones to be analyzed in the individual neuron, a particularly important concern in heterogeneous tissue such as the brain. Estradiol was administered subcutaneously to ovariectomized rats for 15 min, 30 min, or 2 hr, or a discontinuous schedule of 2 hr on/7 hr off/2 hr on. Levels of precursor and product rRNA were measured in VL-VMN and ARC neurons using a computerized image-analysis system. Significant increases in the levels of precursor rRNA were observed only in the VL-VMN as early as 30 min after hormone exposure, with a doubling in the amount of precursor rRNA occurring at 2 hr. No changes in product rRNA were observed in either brain region at these early times. These data, in conjunction with our previous findings of increases in product rRNA after longer hormone exposure times, lead us to conclude that rRNA gene transcription is activated in rat hypothalamic neurons within 30 min.(ABSTRACT TRUNCATED AT 250 WORDS)

Quantitative assessment of early and discontinuous estradiol-induced effects on ventromedial hypothalamic and preoptic area proteins in female rat brain.

In this study, changes in individual proteins in the ventromedial hypothalamus (VMN) and the preoptic area (POA) of the female rat brain were quantitatively assessed following either a short treatment (2 h) or a discontinuous schedule of estradiol. Ovariectomized (OVX) rats were implanted with estradiol capsules or sham-implanted for the appropriate paradigm and sacrificed by decapitation. Punches of brain tissue containing the VMN and POA were incubated with 35S-methionine and 35S-cysteine, and the labeled proteins separated by two-dimensional gel electrophoresis. Estradiol-induced changes were quantitatively assessed by computerized optical densitometry and subjected to a normalization procedure between pairs of estradiol-treated and OVX control gels. A number of proteins within the VMN and POA were found to be positively or negatively affected in labeling after either hormone administration paradigm. In both brain regions, the population of proteins affected in labeling after 2 h of estradiol treatment were markedly different from those affected after the discontinuous hormone paradigm. Comparison of the VMN and POA also indicated that the populations of proteins affected in labeling by either hormone treatment paradigm were different, with there being only 3 proteins (from a total of 39) affected in the same direction and 2 affected in the opposite direction by the hormone in both regions. These findings lend support to the hypothesis that administration of estradiol results in a molecular cascade of events within brain regions involved in the control of reproductive behavior.(ABSTRACT TRUNCATED AT 250 WORDS)