Peripheral Nerve Blocks Outperform General Anesthesia for Pain Control in Arthroscopic Rotator Cuff Repair: A Systematic Review and Meta-analysis.

PURPOSE: The purpose of this review is to compare the effectiveness of different peripheral nerve blocks and general anesthesia (GA) in controlling postoperative pain after arthroscopic rotator cuff repair (ARCR). METHODS: A Preferred Reporting Items for Systematic Reviews and Meta-Analyses-compliant systematic review was conducted for the period of January 1, 2005, to February 16, 2021, by searching the following databases: PubMed, Cochrane, Embase, and Arthroscopyjournal.org. The primary outcomes of interest included 1-hour, 24-hour, and 48-hour pain scores on a numeric rating scale or visual analog scale (VAS). Inclusion criteria were English language studies reporting on adults (≥18 years) undergoing ARCR with peripheral nerve blockade. To synthesize subjective pain score data at each evaluation time point across studies, we performed random-effects network meta-regression analyses accounting for baseline pain score as a covariate. RESULTS: A total of 14 randomized controlled trials with 851 patients were included in the meta-analysis. Data from six different nerve block interventions, single-shot interscalene brachial plexus nerve block (s-ISB; 37.8% [322/851]), single-shot suprascapular nerve block (s-SSNB; 9.9% [84/851]), continuous ISB (c-ISB; 17.5% [149/851]), continuous SSNB (c-SSNB; 6.9% [59/851]), s-ISB combined with SSNB (s-ISB+SSNB; 5.8% [49/851]), s-SSNB combined with axillary nerve block (s-SSNB+ANB; 4.8% [41/851]), as well as GA (17.3% [147/851]) were included. Our meta-analysis demonstrated that c-ISB block had a significant reduction in pain score relative to GA at 1-hour postoperation (mean difference [MD]: -1.8; 95% credible interval [CrI] = -3.4, -.08). There were no significant differences in VAS pain scores relative to GA at 24 and 48 hours postoperatively. However, s-ISB+SSNB had a significant reduction in 48-hour pain score compared to s-ISB (MD = -1.07; 95% CrI = -1.92, -.22). CONCLUSIONS: It remains unclear which peripheral nerve block strategy is optimal for ARCR. However, peripheral nerve blocks are highly effective at attenuating postoperative ARCR pain and should be more widely considered as an alternative over general anesthesia alone. LEVEL OF EVIDENCE: Level II Systematic review and meta-analysis of Level I and II studies.

Cognitive deficits among patients surviving aneurysmal subarachnoid hemorrhage. A contemporary systematic review.

BACKGROUND: Subarachnoid hemorrhage (SAH) is associated with high rates of morbidity, including neurological and cognitive deficits that may be difficult to identify and quantify. This review provides an update on the cognitive deficits that may result from spontaneous aneurysmal SAH (aSAH) and identifies factors that may help predict and manage these deficits at discharge and thereafter. MATERIALS AND METHODS: We conducted a systematic review of PubMed and Google Scholar to identify studies published between 2010 and 2019 that assessed cognitive deficits at discharge and during follow-up in patients with aSAH. Full-text articles were assessed for information regarding cognitive testing and factors that may be associated with functional outcomes in this population. RESULTS: We reviewed 65 studies published since 2010 that described the cognitive deficits associated with non-traumatic aSAH. Such deficits may impact functional outcomes, quality of life, and return to work and may result in cognitive impairments, such as memory difficulties, speech problems, and psychiatric disorders. CONCLUSIONS: Patients with aSAH, even those that appear normal at the time of hospital discharge, may harbor cognitive deficits that are difficult to detect, yet can interfere with daily functioning. Further research is needed to provide additional information and to identify stronger correlations to be used in the identification, treatment, and amelioration of long-term cognitive deficits in aSAH patients, including those who are discharged with good clinical outcomes scores.

Superficial temporal artery to middle cerebral artery (STA-MCA) bypass via retrograde arterial anastomosis in a patient with common carotid artery occlusion: a case report.

The standard superficial temporal artery to middle cerebral artery (STA-MCA) bypass depends on adequate antegrade flow in the STA. In the setting of occlusion of the common or external carotid arteries, revascularization requires modification of the standard bypass procedure. A patient with prior history of irradiation for head and neck carcinoma presented with an ischemic injury and fluctuating neurologic deficit not responsive to medical therapy. His left common carotid artery was occluded, but angiographic evaluation demonstrated retrograde filling of his left STA. Reverse STA-MCA bypass was performed, taking advantage of spontaneous collateralization which allowed for retrograde filling of the STA.

Biophysical comparison of soluble amyloid-ß(1-42) protofibrils, oligomers, and protofilaments.

Some of the pathological hallmarks of the Alzheimer's disease brain are senile plaques composed of insoluble amyloid-ß protein (Aß) fibrils. However, much of the recent emphasis in research has been on soluble Aß aggregates in response to a growing body of evidence that shows that these species may be more neurotoxic than fibrils. Within this subset of soluble aggregated Aß are protofibrils and oligomers. Although each species has been widely investigated separately, few studies have directly compared and contrasted their physical properties. In this work, we examined well-recognized preparations of Aß(1-42) oligomers and protofibrils with multiangle (MALS) and dynamic (DLS) light scattering in line with, or following, size-exclusion chromatography (SEC). Multiple SEC-MALS analyses of protofibrils revealed molecular weight (Mw) gradients ranging from 200 to 2600 kDa. Oligomeric Aß species are generally considered to be a smaller and more nascent than protofibrils. However, oligomer Mw values ranged from 225 to 3000 kDa, larger than that for protofibrils. Root-mean-square radius (Rg) values correlated with the Mw trends with protofibril Rg values ranging from 16 to 35 nm, while oligomers produced one population at 40-43 nm with a more disperse population from 22 to 39 nm. Hydrodynamic radius (RH) measurements by DLS and thioflavin T fluorescence measurements indicated that protofibrils and oligomers had commonalities, yet electron microscopy revealed morphological differences between the two. SEC-purified Aß(1-42) monomer at lower concentrations was slower to nucleate but formed protofibrils (1500 kDa) or soluble protofilaments (3000 kDa) depending on the buffer type. The findings from these studies shed new light on the similarities and differences between distinct soluble aggregated Aß species.

Stability of early-stage amyloid-ß(1-42) aggregation species.

Accumulation of aggregated amyloid-ß protein (Aß) is an important feature of Alzheimer's disease. There is significant interest in understanding the initial steps of Aß aggregation due to the recent focus on soluble Aß oligomers. In vitro studies of Aß aggregation have been aided by the use of conformation-specific antibodies which recognize shape rather than sequence. One of these, OC antiserum, recognizes certain elements of fibrillar Aß across a broad range of sizes. We have observed the presence of these fibrillar elements at very early stages of Aß incubation. Using a dot blot assay, OC-reactivity was found in size exclusion chromatography (SEC)-purified Aß(1-42) monomer fractions immediately after isolation (early-stage). The OC-reactivity was not initially observed in the same fractions for Aß(1-40) or the aggregation-restricted Aß(1-42) L34P but was detected within 1-2weeks of incubation. Stability studies demonstrated that early-stage OC-positive Aß(1-42) aggregates were resistant to 4M urea or guanidine hydrochloride but sensitive to 1% sodium dodecyl sulfate (SDS). Interestingly, the sensitivity to SDS diminished over time upon incubation of the SEC-purified Aß(1-42) solution at 4°C. Within 6-8days the OC-positive Aß42 aggregates were resistant to SDS denaturation. The progression to, and development of, SDS resistance for Aß(1-42) occurred prior to thioflavin T fluorescence. In contrast, Aß(1-40) aggregates formed after 6days of incubation were sensitive to both urea and SDS. These findings reveal information on some of the earliest events in Aß aggregation and suggest that it may be possible to target early-stage aggregates before they develop significant stability.

Intravascular hemolysis following low dose daily rifampin.

We report two pediatric patients with rifampin-induced hemolysis following treatment with low daily dose rifampin for methicillin-resistant Staphylococcus aureus (MRSA). With the increased use of rifampin to treat MRSA, physicians should be aware that patients receiving rifampin therapy are at risk for hemolysis, even at low daily doses.

Anaplastic large cell lymphoma: a flow cytometric analysis of 29 cases.

We report our experience with flow cytometric (FC) analysis of 29 cases of anaplastic large cell lymphoma (ALCL). Morphologic analysis of processed cytocentrifuged preparations demonstrated neoplastic cells in 28 cases. In 25 of these, an aberrant lymphoid population was detected by FC analysis. The majority showed high orthogonal light scatter, similar to monocytes or granulocytes. Of the antigens CD2, CD3, CD4, CD5, and CD7, 5 cases expressed 1, 8 expressed 2, 6 expressed 3, 3 expressed 4, and 3 expressed all 5. CD4 was expressed most commonly (20/25 [80%]), followed by CD2 (18/25 [72%]), CD3 (10/25 [40%]), and CD5 and CD7 (8/25 [32%] each). CD45 was expressed in 23 of 25 cases and CD13 in 7 of 9. Of 21 cases, 13 were anaplastic lymphoma kinase (ALK)+, all of which were CD4+, vs 5 of 8 ALK - cases (P = .042). Most ALCLs can be detected and characterized by multiparameter FC analysis. However, light scatter gating on typical lymphoid regions may yield false-negative results in a substantial number of cases.

The influence of gold surface texture on microglia morphology and activation.

Microglial cells play a critical role in the propagation of neuroinflammation in the central nervous system. Microglia sense and respond to environmental signals including chemical, physical and biological cues from the surrounding cell/tissue components. In this project, our goal was to examine the effects of surface texture on BV-2 microglia morphology and function by comparing flat and nanoporous gold (np-Au) surfaces to the more conventional glass. The biocompatibility of np-Au with microglia was evaluated using functional cell assays and high resolution imaging with scanning electron microscopy (SEM). Microglia seeded on glass, ultra-flat gold (UF-Au), ultra-thin (UT) np-Au and np-Au monolith were adherent to all surfaces and their viability was not compromised as assessed by multiple toxicity assays. SEM revealed detailed morphological characteristics of adherent microglia and indicated few dramatic changes as a result of the different surfaces. Microglia proliferation was hampered by np-Au monolith but less by UT np-Au and not at all on UF-Au or glass. Microglial activation, measured by tumor necrosis factor α (TNFα) production, was fully functional (and equivalent) on all gold surfaces compared to glass. The present findings should help further the understanding of basic microglia biology on textured surfaces and more fully evaluate np-Au as a multi-functional biocompatible material. The knowledge obtained and technology developed will have a significant impact in the fabrication of nanoelectronic devices, chemical sensor development, porous nanostructured materials for BioMEMs/NEMs integration, and functional biomaterial coatings for drug delivery.

Amyloid-ß(1-42) protofibrils formed in modified artificial cerebrospinal fluid bind and activate microglia.

Soluble aggregated forms of amyloid-ß protein (Aß) have garnered significant attention recently for their role in Alzheimer's disease (AD). Protofibrils are a subset of these soluble species and are considered intermediates in the aggregation pathway to mature Aß fibrils. Biological studies have demonstrated that protofibrils exhibit both toxic and inflammatory activities. It is important in these in vitro studies to prepare protofibrils using solution conditions that are appropriate for cellular studies as well as conducive to biophysical characterization of protofibrils. Here we describe the preparation and characterization of Aß(1-42) protofibrils in modified artificial cerebrospinal fluid (aCSF) and demonstrate their prominent binding and activation of microglial cells. A simple phosphate/bicarbonate buffer system was prepared that maintained the ionic strength and cell compatibility of F-12 medium but did not contain numerous supplements that interfere with spectroscopic analyses of Aß protofibrils. Reconstitution of Aß(1-42) in aCSF and isolation with size exclusion chromatography (SEC) revealed curvilinear ß-sheet protofibrils <100 nm in length and hydrodynamic radii of 21 nm. Protofibril concentration determination by BCA assay, which was not possible in F-12 medium, was more accurately measured in aCSF. Protofibrils formed and isolated in aCSF, but not monomers, markedly stimulated TNFα production in BV-2 and primary microglia and bound in significant amounts to microglial membranes. This report demonstrates the suitability of a modified aCSF system for preparing SEC-isolated Aß(1-42) protofibrils and underscores the unique ability of protofibrils to functionally interact with microglia.

Isolated amyloid-ß(1-42) protofibrils, but not isolated fibrils, are robust stimulators of microglia.

Senile plaques composed of amyloid-ß protein (Aß) are an unshakable feature of the Alzheimer's disease (AD) brain. Although there is significant debate on the role of the plaques in AD progression, there is little disagreement on their role in stimulating a robust inflammatory response within the context of the disease. Significant inflammatory markers such as activated microglia and cytokines are observed almost exclusively surrounding the plaques. However, recent evidence suggests that the plaque exterior may contain a measurable level of soluble Aß aggregates. The observations that microglia activation in vivo is selectively stimulated by distinct Aß deposits led us to examine what specific form of Aß is the most effective proinflammatory mediator in vitro. We report here that soluble prefibrillar species of Aß(1-42) were better than fibrils at inducing microglial tumor necrosis factor α (TNFα) production in either BV-2 and primary murine microglia. Reconstitution of Aß(1-42) in NaOH followed by dilution into F-12 media and isolation with size exclusion chromatography (SEC) revealed classic curvilinear ß-sheet protofibrils 100 nm in length. The protofibrils, but not monomers, markedly activated BV-2 microglia. Comparisons were also made between freshly isolated protofibrils and Aß(1-42) fibrils prepared from SEC-purified monomer. Surprisingly, while isolated fibrils had a much higher level of thioflavin T fluorescence per mole, they were not effective at stimulating either primary or BV-2 murine microglia compared to protofibrils. Furthermore, SEC-isolated Aß(1-40) protofibrils exhibited significantly less activity than concentration-matched Aß(1-42). This report is the first to demonstrate microglial activation by SEC-purified protofibrils, and the overall findings indicate that small, soluble Aß(1-42) protofibrils induce much greater microglial activation than mature insoluble fibrils.