Perioperative and long-term operative outcomes after surgery for trigeminal neuralgia: microvascular decompression vs percutaneous balloon ablation

<p>Abstract</p> <p>Objectives</p> <p>Numerous medical and surgical therapies have been utilized to treat the symptoms of trigeminal neuralgia (TN). This retrospective study compares patients undergoing either microvascular decompression or balloon ablation of the trigeminal ganglion and determines which produces the best long-term outcomes.</p> <p>Methods</p> <p>A 10-year retrospective chart review was performed on patients who underwent microvascular decompression (MVD) or percutaneous balloon ablation (BA) surgery for TN. Demographic data, intraoperative variables, length of hospitalization and symptom improvement were assessed along with complications and recurrences of symptoms after surgery. Appropriate statistical comparisons were utilized to assess differences between the two surgical techniques.</p> <p>Results</p> <p>MVD patients were younger but were otherwise similar to BA patients. Intraoperatively, twice as many BA patients developed bradycardia compared to MVD patients. 75% of BA patients with bradycardia had an improvement of symptoms. Hospital stay was shorter in BA patients but overall improvement of symptoms was better with MVD. Postoperative complication rates were similar (21% vs 26%) between the BA and MVD groups.</p> <p>Discussion</p> <p>MVD produced better overall outcomes compared to BA and may be the procedure of choice for surgery to treat TN.</p

Molecular mechanisms and cellular functions of cGAS-STING signalling

The cGAS–STING signalling axis, comprising the synthase for the second messenger cyclic GMP–AMP (cGAS) and the cyclic GMP–AMP receptor stimulator of interferon genes (STING), detects pathogenic DNA to trigger an innate immune reaction involving a strong type I interferon response against microbial infections. Notably however, besides sensing microbial DNA, the DNA sensor cGAS can also be activated by endogenous DNA, including extranuclear chromatin resulting from genotoxic stress and DNA released from mitochondria, placing cGAS–STING as an important axis in autoimmunity, sterile inflammatory responses and cellular senescence. Initial models assumed that co-localization of cGAS and DNA in the cytosol defines the specificity of the pathway for non-self, but recent work revealed that cGAS is also present in the nucleus and at the plasma membrane, and such subcellular compartmentalization was linked to signalling specificity of cGAS. Further confounding the simple view of cGAS–STING signalling as a response mechanism to infectious agents, both cGAS and STING were shown to have additional functions, independent of interferon response. These involve non-catalytic roles of cGAS in regulating DNA repair and signalling via STING to NF-κB and MAPK as well as STING-mediated induction of autophagy and lysosome- dependent cell death. We have also learnt that cGAS dimers can multimerize and undergo liquid–liquid phase separation to form biomolecular condensates that could importantly regulate cGAS activation. Here, we review the molecular mechanisms and cellular functions underlying cGAS–STING activation and signalling, particularly highlighting the newly emerging diversity of this signalling pathway and discussing how the specificity towards normal, damage-induced and infection-associated DNA could be achieved

The Microbial Ecology of a Hyper-Alkaline Spring, and Impacts of an Alkali-Tolerant Community During Sandstone Batch and Column Experiments Representative of a Geological Disposal Facility for Intermediate-Level Radioactive Waste

Naturally occurring hyper-alkaline springs and associated hyper-alkaline environments may have components that are analogous to a cement-based deep geological disposal facility (GDF) for intermediate level radioactive waste (ILW). Such high pH environments could give insights into the biogeochemical processes that could occur in the region of a GDF environment after the ingress of GDF-derived groundwater leads to the formation of a hyper-alkaline plume in the surrounding rock mass. This study focuses on the microbial community composition found at a highly alkaline spring near Buxton, Derbyshire, England, and the variation in community structure across spatially separated sample points of contrasting pH values (ranging from pH 7.5–13). Communities containing alkaliphilic and alkalitolerant bacteria were observed across the site by PCR amplification and 16S rRNA gene pyrosequencing and included members of the families Comamonadaceae and Xanthomonadaceae. At pH 13, the sequence library was dominated by Gammaproteobacteria of the families Pseudomonadaceae and Enterobacteriaceae. Bacterial communities from the site demonstrated the ability to reduce Fe(III) in microcosm experiments up to pH 11.5, suggesting the potential to reduce other metals and radionuclides of relevance to cement-encapsulated intermediate level radioactive waste (ILW) disposal. In laboratory column flow-through experiments, microbial communities present at the field site were also able to colonize crushed sandstone. Bacterial community composition varied between columns that had been supplied with alkali surface waters from the site amended with carbon (lactate and acetate, as proxies for products of cellulose degradation from ILW), and control columns that were not supplied with added carbon. Members of the family Clostridiaceae dominated the sequence library obtained from the carbon amended column inlet (45.8% of library), but became less dominant at the outlet (20.8%). Members of the family Sphingomonadaceae comprised 11.8% of the sequence library obtained from the control column inlet, but were not present in sediments collected from the column outlet, whereas the relative abundance of members of the family Comamonadaceae increased from the column inlet (35.2%) to the column outlet (57.2%). The spatial variation in community composition within the columns is indicative of discrete biogeochemical zonation in these flow-through systems