There has been much interest in the construction of soft nanomaterials in solution due to a desire to emulate the exquisite structure and function of Nature's equivalents (e.g. enzymes, viruses, ...proteins and DNA). Nature's soft nanomaterials are capable of selectivity, precision and efficiency in areas such as information storage and replication, transportation and delivery, and synthesis and catalysis. To this end, the use of small molecules, amphiphiles, colloids, and polymers have been investigated for the development of advanced materials in myriad fields of biomedicine and synthetic chemistry. Two major challenges are faced in this area of research: the reproducible, scalable and precise synthesis of such constructs and the reliable, accurate and in-depth analysis of these materials. This tutorial review will focus on this second aspect and provide a guide for the characterisation and analysis of soft nanomaterials in solution using scattering and microscopic techniques.
A Hydropneumothorax That Never Was Kourouni, Ismini; Parekh, Karishma; Mathew, Joseph P.
Chest,
September 2021, 2021-09-00, 20210901, Letnik:
160, Številka:
3
Journal Article
For half a century, it has been known that some patients experience neurocognitive dysfunction after cardiac surgery; however, defining its incidence, course, and causes remains challenging and ...controversial. Various terms have been used to describe neurocognitive dysfunction at different times after cardiac surgery, ranging from “postoperative delirium” to “postoperative cognitive dysfunction or decline.” Delirium is a clinical diagnosis included in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5). Postoperative cognitive dysfunction is not included in the DSM-5 and has been heterogeneously defined, though a recent international nomenclature effort has proposed standardized definitions for it. Here, the authors discuss pathophysiologic mechanisms that may underlie these complications, review the literature on methods to prevent them, and discuss novel approaches to understand their etiology that may lead to novel treatment strategies. Future studies should measure both delirium and postoperative cognitive dysfunction to help clarify the relationship between these important postoperative complications.
Introduction
Treatment refractory ventricular arrhythmias (VAs) are often driven and exacerbated by heightened sympathetic tone. We aim to conduct a systematic review and meta‐analysis of published ...studies of a temporary percutaneous stellate ganglion block (SGB) on VA burden and defibrillation episodes in patients with treatment refractory VAs.
Methods
Relevant studies from January 1960 through May 2017 were identified in PubMed and Google Scholar. We performed a patient‐level analysis using Student's t‐test to compare outcomes before and after SGB.
Results
We identified 22 unique case series with a total of 35 patients. Patients were 57 ± 17 years old and 69% were males with a high burden of VA. A unilateral (left)‐sided SGB was used in 85.7% (30 of 35) of cases and the remaining were bilateral SGB. The use of a unilateral or bilateral SGB resulted in a significant reduction of VA episodes (24‐hours pre: mean 16.5 CI 9.7–23.1 events vs. post: mean 1.4 CI 0.85–2.01 events; P = 0.0002) and need for defibrillation (24‐hours pre: mean 14.2 CI 6.8–21.6 vs. post: mean 0.6 CI 0.3–0.9; P = 0.0026). Furthermore, SGB was significantly associated with a reduction of VA burden regardless of etiology of cardiomyopathy, type of ventricular rhythm, and degree of contractile dysfunction. SGB was followed by surgical sympathectomy in 21% of cases.
Conclusions
Early experience suggests that SGB is associated with an acute reduction in the VA burden and offers potential promise for a broader use in high‐risk populations. Randomized controlled studies are needed to confirm the safety and efficacy of this therapy.
Abstract
OBJECTIVES
Hypothermic circulatory arrest is essential to aortic arch surgery, although consensus regarding optimal cerebral protection strategy remains lacking. We evaluated the current use ...and comparative effectiveness of hypothermia/cerebral perfusion (CP) strategies in aortic arch surgery.
METHODS
Using the Society of Thoracic Surgeons Database, cases of aortic arch surgery with hypothermic circulatory arrest from 2011 to 2014 were categorized by hypothermia strategy—deep/profound (D/P; ≤20°C), low–moderate (L-M; 20.1–24°C), and high–moderate (H-M; 24.1–28°C)—and CP strategy—no CP, antegrade (ACP), retrograde (RCP) or both ACP/RCP. After adjusting for potential confounders, strategies were compared by composite end-point (operative mortality or neurologic complication).
RESULTS
Of the 12 521 aortic arch repairs with hypothermic circulatory arrest, the most common combined strategies were straight D/P without CP (25%), D/P + RCP (16%) and D/P + ACP (14%). Overall rates of the primary end-point, operative mortality and stroke were 23%, 12% and 8%, respectively. Among the 7 most common strategies, the 2 not utilizing CP (straight D/P and straight L-M) appeared inferior, associated with significantly higher risk of the composite end-point (odds ratio: 1.6; P < 0.01); there was no significant difference in composite outcome between the remaining strategies (D/P + ACP, D/P + RCP, L-M + ACP, L-M + RCP and H-M + ACP).
CONCLUSIONS
In a comparative effectiveness study of cerebral protection strategies for aortic arch repair, strategies without adjunctive CP, including the most commonly utilized strategy of straight D/P hypothermia, appeared inferior to those utilizing CP. There was no clearly superior strategy among remaining techniques, and randomized trials are needed to define best practice.
Pain is a critical component hindering recovery and regaining of function after surgery, particularly in the elderly. Understanding the role of pain signaling after surgery may lead to novel ...interventions for common complications such as delirium and postoperative cognitive dysfunction. Using a model of tibial fracture with intramedullary pinning in male mice, associated with cognitive deficits, we characterized the effects on the primary somatosensory system. Here we show that tibial fracture with pinning triggers cold allodynia and up-regulates nerve injury and inflammatory markers in dorsal root ganglia (DRGs) and spinal cord up to 2 wk after intervention. At 72 h after surgery, there is an increase in activating transcription factor 3 (ATF3), the neuropeptides galanin and neuropeptide Y (NPY), brain-derived neurotrophic factor (BDNF), as well as neuroinflammatory markers including ionized calcium-binding adaptor molecule 1 (Iba1), glial fibrillary acidic protein (GFAP), and the fractalkine receptor CX3CR1 in DRGs. Using an established model of complete transection of the sciatic nerve for comparison, we observed similar but more pronounced changes in these markers. However, protein levels of BDNF remained elevated for a longer period after fracture. In the hippocampus, BDNF protein levels were increased, yet there were no changes in Bdnf mRNA in the parent granule cell bodies. Further, c-Fos was down-regulated in the hippocampus, together with a reduction in neurogenesis in the subgranular zone. Taken together, our results suggest that attenuated BDNF release and signaling in the dentate gyrus may account for cognitive and mental deficits sometimes observed after surgery.
BACKGROUND:Cardiac surgery requiring cardiopulmonary bypass is associated with platelet activation. Because platelets are increasingly recognized as important effectors of ischemia and end-organ ...inflammatory injury, the authors explored whether postoperative nadir platelet counts are associated with acute kidney injury (AKI) and mortality after coronary artery bypass grafting (CABG) surgery.
METHODS:The authors evaluated 4,217 adult patients who underwent CABG surgery. Postoperative nadir platelet counts were defined as the lowest in-hospital values and were used as a continuous predictor of postoperative AKI and mortality. Nadir values in the lowest 10th percentile were also used as a categorical predictor. Multivariable logistic regression and Cox proportional hazard models examined the association between postoperative platelet counts, postoperative AKI, and mortality.
RESULTS:The median postoperative nadir platelet count was 121 × 10/l. The incidence of postoperative AKI was 54%, including 9.5% (215 patients) and 3.4% (76 patients) who experienced stages II and III AKI, respectively. For every 30 × 10/l decrease in platelet counts, the risk for postoperative AKI increased by 14% (adjusted odds ratio, 1.14; 95% CI, 1.09 to 1.20; P < 0.0001). Patients with platelet counts in the lowest 10th percentile were three times more likely to progress to a higher severity of postoperative AKI (adjusted proportional odds ratio, 3.04; 95% CI, 2.26 to 4.07; P < 0.0001) and had associated increased risk for mortality immediately after surgery (adjusted hazard ratio, 5.46; 95% CI, 3.79 to 7.89; P < 0.0001).
CONCLUSION:The authors found a significant association between postoperative nadir platelet counts and AKI and short-term mortality after CABG surgery.
Atrial fibrillation has a multifactorial pathophysiology influenced by cardiac autonomic innervation. Both sympathetic and parasympathetic influences are profibrillatory. Innovative therapies ...targeting the neurocardiac axis include catheter ablation or pharmacologic suppression of ganglionated plexi, renal sympathetic denervation, low-level vagal stimulation, and stellate ganglion blockade. To date, these therapies have variable efficacy. As our understanding of atrial fibrillation and the cardiac nervous system expands, our approach to therapeutic neuromodulation will continue evolving for the benefit of those with AF.
Postoperative cognitive dysfunction (POCD) is a significant cause of morbidity after noncardiac surgery. Identified risk factors are largely limited to demographic characteristics. We hypothesized ...that POCD was associated with apolipoprotein E4 (APOE4) genotype and plasma biomarkers of brain injury and inflammation.
Three hundred ninety-four patients older than 55 yr undergoing major elective noncardiac surgery were enrolled in this prospective observational study. Apolipoprotein E genotyping was performed at baseline. Plasma was collected at baseline and end of surgery and at 4.5, 24, and 48-h postoperatively. Six protein biomarkers were assayed (B-type natriuretic peptide, C-reactive protein, D-dimer, matrix metalloproteinase-9, neuron-specific enolase, and S-100B). Neurocognitive testing was conducted at baseline and at 6 weeks and 1 yr after surgery; scores were subjected to factor analysis. The association of APOE4 and biomarkers with POCD was tested using multivariable regression modeling.
Three hundred fifty patients (89%) completed 6-week neurocognitive testing. POCD occurred in 54.3% of participants at 6 weeks and 46.1% at 1 yr. There was no difference in POCD between patients with or without the APOE4 allele (56.6 vs. 52.6%; P = 0.58). The continuous cognitive change score (mean +/- SD) was similar between groups (APOE4: 0.05 +/- 0.27 vs. non-APOE4: 0.07 +/- 0.28; P = 0.53). Two hundred ninety-one subjects (74%) completed testing at 1 yr. POCD occurred in 45.9% of APOE4 subjects versus 46.3% of non-APOE4 subjects (P = 0.95). The cognitive score was again similar (APOE4: 0.08 +/- 0.27 vs. non-APOE4: 0.05 +/- 0.25; P = 0.39). Biomarker levels were not associated with APOE4 genotype or cognition at 6 weeks or 1 yr.
Cognitive decline after major noncardiac surgery is not associated with APOE4 genotype or plasma biomarker levels.
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