Immediate and delayed autologous abdominal microvascular flap breast reconstruction in patients receiving adjuvant, neoadjuvant or no radiotherapy: a meta-analysis of clinical and quality-of-life outcomes.

BACKGROUND: Effects of postmastectomy radiotherapy (PMRT) on autologous breast reconstruction (BRR) are controversial regarding surgical complications, cosmetic appearance and quality of life (QOL). This systematic review evaluated these outcomes after abdominal free flap reconstruction in patients undergoing postoperative adjuvant radiotherapy (PMRT), preoperative radiotherapy (neoadjuvant radiotherapy) and no radiotherapy, aiming to establish evidence-based optimal timings for radiotherapy and BRR to guide contemporary management. METHODS: The study was registered on PROSPERO (CRD42017077945). Embase, MEDLINE, Google Scholar, CENTRAL, Science Citation Index and ClinicalTrials.gov were searched (January 2000 to August 2018). Study quality and risk of bias were assessed using GRADE and Cochrane's ROBINS-I respectively. RESULTS: Some 12 studies were identified, involving 1756 patients (350 PMRT, 683 no radiotherapy and 723 neoadjuvant radiotherapy), with a mean follow-up of 27·1 (range 12·0-54·0) months for those having PMRT, 16·8 (1·0-50·3) months for neoadjuvant radiotherapy, and 18·3 (1·0-48·7) months for no radiotherapy. Three prospective and nine retrospective cohorts were included. There were no randomized studies. Five comparative radiotherapy studies evaluated PMRT and four assessed neoadjuvant radiotherapy. Studies were of low quality, with moderate to serious risk of bias. Severe complications were similar between the groups: PMRT versus no radiotherapy (92 versus 141 patients respectively; odds ratio (OR) 2·35, 95 per cent c.i. 0·63 to 8·81, P = 0·200); neoadjuvant radiotherapy versus no radiotherapy (180 versus 392 patients; OR 1·24, 0·76 to 2·04, P = 0·390); and combined PMRT plus neoadjuvant radiotherapy versus no radiotherapy (272 versus 453 patients; OR 1·38, 0·83 to 2·32, P = 0·220). QOL and cosmetic studies used inconsistent methodologies. CONCLUSION: Evidence is conflicting and study quality was poor, limiting recommendations for the timing of autologous BRR and radiotherapy. The impact of PMRT and neoadjuvant radiotherapy appeared to be similar.

ANTECEDENTES: En pacientes sometidas a una reconstrucción mamaria (breast reconstruction, BRR) con tejido autólogo se discuten los efectos de la radioterapia post-mastectomía (post-mastectomy radiotherapy, PMRT) en las complicaciones quirúrgicas, el resultado estético y la calidad de vida (quality of life, QOL). Esta revisión sistemática evaluó dichos resultados tras una reconstrucción mamaria con un colgajo libre abdominal en pacientes tratadas con PMRT, radioterapia preoperatoria (Neo RT) y sin radioterapia (RT), a fin de establecer los momentos óptimos de la RT y BRR basados en la evidencia, como guía del tratamiento actual. MÉTODOS: El estudio se registró en la base de datos PROSPERO (CRD42017077945). Se realizaron búsquedas en Embase, MEDLINE, Google Scholar, CENTRAL, Science Citation Index y Clinicaltrials.gov (enero de 2000-agosto de 2018). La calidad de los estudios y el riesgo de sesgo se evaluaron mediante las herramientas GRADE y ROBINS-I de la Cochrane, respectivamente. RESULTADOS: Se identificaron 12 estudios que incluían 1.756 pacientes (350 PMRT, 683 sin RT y 723 Neo RT), con una mediana de seguimiento de 27,1 meses (rango 12,0-54,0) para PMRT, 16,8 meses (1,0-50,3) para Neo RT y 18,3 meses (1,0-48,7) para sin RT. Se incluyeron tres cohortes prospectivas y nueve retrospectivas. No hubo estudios aleatorizados. Los estudios comparativos de RT evaluaron la PMRT (n = 5) y la Neo RT (n = 4). Todos los estudios fueron de baja calidad, con riesgos de sesgo de moderados a graves. Las complicaciones graves fueron similares entre los grupos: PMRT (n = 92) versus sin RT (n = 141), razón de oportunidades (odds ratio, OR) 2,35, i.c. del 95% 0,63-8,81), P = 0,200; Neo RT (n = 180) versus no RT (n = 392) (OR 1,24, i.c. del 95% 0,76-2,04), P = 0,390; o RT combinada (PMRT y neoadyuvante) (n = 272) versus no RT (n = 453) (OR 1,38, i.c. del 95% 0,83-2,32), P = 0,220. Los estudios de calidad de vida y de resultados estéticos utilizaron metodologías poco consistentes. CONCLUSIÓN: La evidencia es contradictoria y la calidad de los estudios muy pobre, hechos que limitan las posibles recomendaciones para el momento de la BRR con tejido autólogo y la RT. El impacto de la PMRT o la Neo RT parecen ser similares.

Cohesion, order and information flow in the collective motion of mixed-species shoals.

Despite the frequency with which mixed-species groups are observed in nature, studies of collective behaviour typically focus on single-species groups. Here, we quantify and compare the patterns of interactions between three fish species, threespine sticklebacks (Gasterosteus aculeatus), ninespine sticklebacks (Pungitius pungitius) and roach (Rutilus rutilus) in both single- and mixed-species shoals in the laboratory. Pilot data confirmed that the three species form both single- and mixed-species shoals in the wild. In our laboratory study, we found that single-species groups were more polarized than mixed-species groups, while single-species groups of threespine sticklebacks and roach were more cohesive than mixed shoals of these species. Furthermore, while there was no difference between the inter-individual distances between threespine and ninespine sticklebacks within mixed-species groups, there was some evidence of segregation by species in mixed groups of threespine sticklebacks and roach. There were differences between treatments in mean pairwise transfer entropy, and in particular we identify species-differences in information use within the mixed-species groups, and, similarly, differences in responses to conspecifics and heterospecifics in mixed-species groups. We speculate that differences in the patterns of interactions between species in mixed-species groups may determine patterns of fission and fusion in such groups.

Nitrogen losses in anoxic marine sediments driven by Thioploca-anammox bacterial consortia.

Ninety per cent of marine organic matter burial occurs in continental margin sediments, where a substantial fraction of organic carbon escapes oxidation and enters long-term geologic storage within sedimentary rocks. In such environments, microbial metabolism is limited by the diffusive supply of electron acceptors. One strategy to optimize energy yields in a resource-limited habitat is symbiotic metabolite exchange among microbial associations. Thermodynamic and geochemical considerations indicate that microbial co-metabolisms are likely to play a critical part in sedimentary organic carbon cycling. Yet only one association, between methanotrophic archaea and sulphate-reducing bacteria, has been demonstrated in marine sediments in situ, and little is known of the role of microbial symbiotic interactions in other sedimentary biogeochemical cycles. Here we report in situ molecular and incubation-based evidence for a novel symbiotic consortium between two chemolithotrophic bacteria--anaerobic ammonium-oxidizing (anammox) bacteria and the nitrate-sequestering sulphur-oxidizing Thioploca species--in anoxic sediments of the Soledad basin at the Mexican Pacific margin. A mass balance of benthic solute fluxes and the corresponding nitrogen isotope composition of nitrate and ammonium fluxes indicate that anammox bacteria rely on Thioploca species for the supply of metabolic substrates and account for about 57 ± 21 per cent of the total benthic N2 production. We show that Thioploca-anammox symbiosis intensifies benthic fixed nitrogen losses in anoxic sediments, bypassing diffusion-imposed limitations by efficiently coupling the carbon, nitrogen and sulphur cycles.

[Dynamics of the level of plasma vasopressin and its role in the regulation of water-electrolyte metabolism in patients following aortocoronary bypass]. / Dinamika urovnia plazmennogo vazopressina i ego rol' v reguliasii vodno-élekrolitnogo obmena u bol'nykh posle aortokoronarnogo shuntirovaniia.

Changes in plasma vasopressin, K+, Na levels, osmolality in blood and urine samples, as well as hemodynamic parameters, cardiac output and circulating blood volume including, have been assessed in 38 patients 3, 6, 18 and 48 hours after aortocoronary bypass surgery. It has been found that vasopressin blood level in the postoperative period is considerably (5-7 times) higher than physiological hormone level. The main reasons for vasopressin blood level increase are surgical stress, increase in blood plasma osmolality, hypokalemia, a drop of the arterial blood pressure and central venous pressure elevation. Despite a high vasopressin level and its pronounced impact on the renal excretory function, the first postoperative hours are marked by polyuria, mediated mainly by osmotic diuresis due to infusions of high amounts of osmotically active substances.

[The dynamics of parathyroid hormone and calcitonin in surgery with artificial circulation]. / Dinamika paratireoidnogo gormona i kal'tsitonina pri operatsiiakh s iskusstvennym krovoobrashcheniem.

The use of considerable amounts of gelatinol in hypothermal perfusion determined the occurrence of marked hypercalcemia. The hormonal mechanism (parathyroid hormone and calcitonin) responsible for hypercalcemia compensation proved to be inefficient under hypothermal perfusion. A forced diuresis failed to result in rapid normalization of blood calcium concentrations. The volume of gelatinol used during extracorporeal circulation is not to exceed 500 ml.