Casein kinase 1 and 2 phosphorylate Argonaute proteins to regulate miRNA-mediated gene silencing.

MicroRNAs (miRNAs) together with Argonaute (AGO) proteins form the core of the RNA-induced silencing complex (RISC) to regulate gene expression of their target RNAs post-transcriptionally. Argonaute proteins are subjected to intensive regulation via various post-translational modifications that can affect their stability, silencing efficacy and specificity for targeted gene regulation. We report here that in Caenorhabditis elegans, two conserved serine/threonine kinases - casein kinase 1 alpha 1 (CK1A1) and casein kinase 2 (CK2) - regulate a highly conserved phosphorylation cluster of 4 Serine residues (S988:S998) on the miRNA-specific AGO protein ALG-1. We show that CK1A1 phosphorylates ALG-1 at sites S992 and S995, while CK2 phosphorylates ALG-1 at sites S988 and S998. Furthermore, we demonstrate that phospho-mimicking mutants of the entire S988:S998 cluster rescue the various developmental defects observed upon depleting CK1A1 and CK2. In humans, we show that CK1A1 also acts as a priming kinase of this cluster on AGO2. Altogether, our data suggest that phosphorylation of AGO within the cluster by CK1A1 and CK2 is required for efficient miRISC-target RNA binding and silencing.

The RabGAP TBC-11 controls Argonaute localization for proper microRNA function in C. elegans.

Once loaded onto Argonaute proteins, microRNAs form a silencing complex called miRISC that targets mostly the 3'UTR of mRNAs to silence their translation. How microRNAs are transported to and from their target mRNA remains poorly characterized. While some reports linked intracellular trafficking to microRNA activity, it is still unclear how these pathways coordinate for proper microRNA-mediated gene silencing and turnover. Through a forward genetic screen using Caenorhabditis elegans, we identified the RabGAP tbc-11 as an important factor for the microRNA pathway. We show that TBC-11 acts mainly through the small GTPase RAB-6 and that its regulation is required for microRNA function. The absence of functional TBC-11 increases the pool of microRNA-unloaded Argonaute ALG-1 that is likely associated to endomembranes. Furthermore, in this condition, this pool of Argonaute accumulates in a perinuclear region and forms a high molecular weight complex. Altogether, our data suggest that the alteration of TBC-11 generates a fraction of ALG-1 that cannot bind to target mRNAs, leading to defective gene repression. Our results establish the importance of intracellular trafficking for microRNA function and demonstrate the involvement of a small GTPase and its GAP in proper Argonaute localization in vivo.

HMGB1 released from nociceptors mediates inflammation.

Inflammation, the body's primary defensive response system to injury and infection, is triggered by molecular signatures of microbes and tissue injury. These molecules also stimulate specialized sensory neurons, termed nociceptors. Activation of nociceptors mediates inflammation through antidromic release of neuropeptides into infected or injured tissue, producing neurogenic inflammation. Because HMGB1 is an important inflammatory mediator that is synthesized by neurons, we reasoned nociceptor release of HMGB1 might be a component of the neuroinflammatory response. In support of this possibility, we show here that transgenic nociceptors expressing channelrhodopsin-2 (ChR2) directly release HMGB1 in response to light stimulation. Additionally, HMGB1 expression in neurons was silenced by crossing synapsin-Cre (Syn-Cre) mice with floxed HMGB1 mice (HMGB1f/f). When these mice undergo sciatic nerve injury to activate neurogenic inflammation, they are protected from the development of cutaneous inflammation and allodynia as compared to wild-type controls. Syn-Cre/HMGB1fl/fl mice subjected to experimental collagen antibody-induced arthritis, a disease model in which nociceptor-dependent inflammation plays a significant pathological role, are protected from the development of allodynia and joint inflammation. Thus, nociceptor HMGB1 is required to mediate pain and inflammation during sciatic nerve injury and collagen antibody-induced arthritis.

Reverse Fragility Index: Comparing Revision Rates Between Direct Anterior and Other Approaches in Total Hip Arthroplasty. A Systematic Review of Randomized Controlled Trials.

BACKGROUND: Despite increasing adoption of the direct anterior (DA) approach in total hip arthroplasty (THA), uncertainty persists regarding its outcomes beyond the 1-year mark in comparison to other approaches. We used the reverse fragility index (RFI) to evaluate the robustness of reported findings in the literature. METHODS: We conducted a systematic review of randomized controlled trials (RCTs) comparing implant revision rates between DA and other approaches in THA, defined as all those different from DA. Our primary outcome was the RFI, which gauges the number of events needed for a nonsignificant result to become significant, in the revision rate between DA and other approaches. We also calculated the reverse fragility quotient by dividing the RFI by each study's sample size. Median values and interquartile ranges (IQRs) were displayed. RESULTS: A total of 10 RCTs with a total of 971 patients were included. The median RFI was 5 (IQR, 4 to 5), indicating the study's results would be statistically significant if the outcomes of 5 patients in 1 treatment arm were reversed. The median reverse fragility quotient was 0.049 (IQR, 0.04 to 0.057), indicating that a change of outcome in 4.9% of patients would render the revision rate significant. The median number of patients lost to follow-up was 4 (IQR, 0 to 7). Of the 10 RCTs, 6 had more patients lost to follow-up than their respective RFI values. CONCLUSIONS: Notable fragility was evidenced in most studies comparing DA to other approaches for THA. Surgeons should not solely rely on the P value to determine clinical significance and instead use multiple metrics. LEVEL OF EVIDENCE: II.

Do digital health interventions hold promise for stroke prevention and care in Black and Latinx populations in the United States? A scoping review.

BACKGROUND: Black and Latinx populations are disproportionately affected by stroke and are likely to experience gaps in health care. Within fragmented care systems, remote digital solutions hold promise in reversing this pattern. However, there is a digital divide that follows historical disparities in health. Without deliberate attempts to address this digital divide, rapid advances in digital health will only perpetuate systemic biases. This study aimed to characterize the range of digital health interventions for stroke care, summarize their efficacy, and examine the inclusion of Black and Latinx populations in the evidence base. METHODS: We searched PubMed, the Web of Science, and EMBASE for publications between 2015 and 2021. Inclusion criteria include peer-reviewed systematic reviews or meta-analyses of experimental studies focusing on the impact of digital health interventions on stroke risk factors and outcomes in adults. Detailed information was extracted on intervention modality and functionality, clinical/behavioral outcome, study location, sample demographics, and intervention results. RESULTS: Thirty-eight systematic reviews met inclusion criteria and yielded 519 individual studies. We identified six functional categories and eight digital health modalities. Case management (63%) and health monitoring (50%) were the most common intervention functionalities. Mobile apps and web-based interventions were the two most commonly studied modalities. Evidence of efficacy was strongest for web-based, text-messaging, and phone-based approaches. Although mobile applications have been widely studied, the evidence on efficacy is mixed. Blood pressure and medication adherence were the most commonly studied outcomes. However, evidence on the efficacy of the various intervention modalities on these outcomes was variable. Among all individual studies, only 38.0% were conducted in the United States (n = 197). Of these U.S. studies, 54.8% adequately reported racial or ethnic group distribution. On average, samples were 27.0% Black, 17.1% Latinx, and 63.4% White. CONCLUSION: While evidence of the efficacy of selected digital health interventions, particularly those designed to improve blood pressure management and medication adherence, show promise, evidence of how these interventions can be generalized to historically underrepresented groups is insufficient. Including these underrepresented populations in both digital health experimental and feasibility studies is critical to advancing digital health science and achieving health equity.

Functional characterization of chitin synthesis pathway genes, HaAGM and HaUAP, reveal their crucial roles in ecdysis and survival of Helicoverpa armigera (Hübner).

The chitin metabolic pathway is one of the most lucrative targets for designing pest management regimes. Inhibition of the chitin synthesis pathway causes detrimental effects on the normal growth and development of insects. Phospho-N-acetylglucosamine mutase (AGM) and UDP-N-acetylglucosamine pyrophosphorylase (UAP) are two key chitin biosynthesis enzymes in insects including Helicoverpa armigera, a pest of global significance. In the present study, we have identified, cloned and recombinantly expressed AGM and UAP from H. armigera (HaAGM and HaUAP). Biochemical characterization of recombinant HaAGM and HaUAP exhibited high affinities for their natural substrates N-acetyl glucosamine-6-phosphate (Km 38.72 ± 2.41) and N-acetyl glucosamine-1-phosphate (Km 3.66 ± 0.13), respectively. In the coupled enzyme-catalytic assay, HaAGM and HaUAP yielded the end-products, inorganic pyrophosphate and UDP-GlcNAc, confirming their active participation in the chitin synthesis pathway of H. armigera. Gene expression profiling revealed that HaAGM and HaUAP genes were expressed in all developmental stages and key tissues. These genes also showed substantial responses towards the moulting hormone 20-hydroxyecdysone and chitin biosynthesis inhibitor, novaluron. Remarkably, the RNAi-mediated knockdown of either HaAGM or HaUAP led to severe developmental deformities and significant mortality ranging from 65.61 to 72.54%. Overall findings suggest that HaAGM and HaUAP play crucial roles in the ecdysis and survival of H. armigera. Further, these genes could serve as potential targets for designing pest management strategies for H. armigera.

Optimizing Spinal Anesthesia in Same-Day Discharge Knee Arthroplasty Patients: Mepivacaine Versus Ropivacaine.

BACKGROUND: Short-acting spinal anesthetics are playing an increasing role in same-day discharge total joint arthroplasty though their direct comparison remains to be studied. Therefore, this study aims to compare two formulations of spinal anesthesia regarding time to discharge following knee arthroplasty surgery. METHODS: A retrospective study was performed on 207 patients who underwent unicompartmental knee arthroplasty (UKA, n = 172) and total knee arthroplasty (TKA, n = 35) from May 2018 to December 2020 at a single institution and were discharged the same day. Two formulations of the spinal anesthetic were routinely administered in this population: 1) mepivacaine 1.5% 3-4 mL (n = 184) and 2) ropivacaine 0.5% 2.3-2.7 mL (n = 23). Discharge times were subsequently compared between mepivacaine and ropivacaine spinal anesthesia for each surgical procedure and between surgical procedures. RESULTS: There was no significant difference in discharge times between patients receiving mepivacaine versus ropivacaine for UKA (202 minutes [range = 54-449] versus 218 minutes [range = 175-385], P = .45) or TKA (193 minutes [range = 68-384] versus 196 minutes [range = 68-412], P = .93). Similarly, no difference was found in discharge times between UKA and TKA patients receiving mepivacaine (P = .68) or ropivacaine (P = .51). CONCLUSION: There was no significant difference in discharge times between anesthetic agents among knee surgery patients. Therefore, either agent may be recommended for same-day discharge.

Systemic administration of choline acetyltransferase decreases blood pressure in murine hypertension.

Acetylcholine (ACh) decreases blood pressure by stimulating endothelium nitric oxide-dependent vasodilation in resistance arterioles. Normal plasma contains choline acetyltransferase (ChAT) and its biosynthetic product ACh at appreciable concentrations to potentially act upon the endothelium to affect blood pressure. Recently we discovered a T-cell subset expressing ChAT (TChAT), whereby genetic ablation of ChAT in these cells produces hypertension, indicating that production of ACh by TChAT regulates blood pressure. Accordingly, we reasoned that increasing systemic ChAT concentrations might induce vasodilation and reduce blood pressure. To evaluate this possibility, recombinant ChAT was administered intraperitoneally to mice having angiotensin II-induced hypertension. This intervention significantly and dose-dependently decreased mean arterial pressure. ChAT-mediated attenuation of blood pressure was reversed by administration of the nitric oxide synthesis blocker L-nitro arginine methyl ester, indicating ChAT administration decreases blood pressure by stimulating nitic oxide dependent vasodilation, consistent with an effect of ACh on the endothelium. To prolong the half life of circulating ChAT, the molecule was modified by covalently attaching repeating units of polyethylene glycol (PEG), resulting in enzymatically active PEG-ChAT. Administration of PEG-ChAT to hypertensive mice decreased mean arterial pressure with a longer response duration when compared to ChAT. Together these findings suggest further studies are warranted on the role of ChAT in hypertension.

The Emergence of Collaboration in the Education of Fellows and Residents during COVID-19.

BACKGROUND: COVID-19 has created a void in surgical education. Given social distancing and postponed surgeries, unique educational opportunities have arisen. Attendings from 10 adult reconstruction fellowships led a multi-institution web-based weekly collaborative, the Arthroplasty Consortium (AC), developed to educate trainees through complex arthroplasty case-based discussions. METHODS: We performed an anonymous survey of AC participants and American Association of Hip and Knee Surgeons (AAHKS) adult reconstruction fellows. Participants were polled with regards to educational tools used before and after COVID-19 and their value. Specifically, participation in the AC, AAHKS FOCAL (Fellows Orthopedic Continued AAHKS Learning) lectures, institutional lectures, industry lectures, textbooks, online videos, journal articles, and webinars was assessed. RESULTS: Fifty-seven participants responded with 49 (86%) at the fellow level. There was an increase in the use of web-based learning, including the AC (Not applicable pre, 61% post), AAHKS FOCAL lectures (Not applicable pre, 82% post), industry lectures (53% pre, 86% post), and AAHKS/AAOS webinars (35% pre, 56% post). Usage declined with institutional lectures (89% pre, 80% post), textbooks (68% pre, 49% post), and journal articles (97% pre, 90% post), with minimal change in the use of online surgical videos (84% pre, 82% post). The majority of fellows not involved in the AC would like to see the addition of a multi-institutional case conference added to fellowship education. Of AC participants, the 2 most valuable educational tools were the AC and FOCAL lectures. CONCLUSION: Trainee education has changed post-COVID-19 with a greater focus on web-based learning. Multi-institutional collaborative lectures and case-based discussions have significant perceived value among trainees and should be considered important educational tools post-COVID 19.

Post-Operative Remote Monitoring for Same-Day Discharge Elective Orthopedic Surgery: A Pilot Study.

The purposes of this pilot study are to utilize digital remote monitoring to (a) evaluate the usability and satisfaction of a wireless blood pressure (BP) and heart rate (HR) monitor and (b) determine whether these data can enable safe mobilization at home after same-day discharge (SDD) joint replacement. A population of 23 SDD patients undergoing unicompartmental knee arthroplasty (UKA), total knee arthroplasty (TKA), or total hip arthroplasty (THA) were given a cellular BP/HR monitor, with real-time data capture. Patients took three readings after surgery, observing for specific blood pressure decreases, HR increases, or hypotensive symptoms. If any criteria applied, patients followed a hydration protocol and delayed ambulation. Home coaching was also provided to each patient. Patient experience was surveyed, and responses were assessed using descriptive statistics. Of 18 patients discharged (78%), 17 returned surveys, of which 100% reported successful device operation. The mean "ease of use" rating was 8.9/10; satisfaction with home coaching was 9.7/10; and belief that the protocol improved patient safety was 8.4/10. A total of 27.8% (n = 5) had hypotensive readings and appropriately delayed ambulation. Our pilot findings support the feasibility of and confirm the satisfaction with remote monitoring after SDD arthroplasty. All patients with symptoms of hypotension were successfully remotely managed using a standardized hydration protocol prior to safe mobilization.

Direct Drug Analysis in Polymeric Implants Using Desorption Electrospray Ionization - Mass Spectrometry Imaging (DESI-MSI).

PURPOSE: Desorption electrospray ionization mass spectrometry imaging (DESI-MSI) coupled with gas-phase ion mobility spectrometry was used to characterize the drug distribution in polymeric implants before and after exposure to accelerated in vitro release (IVR) media. DESI-MSI provides definitive chemical identification and localization of formulation components, including 2D chemical mapping of individual components with essentially no sample preparation. METHODS: Polymeric implants containing 40% (w/w) entecavir and poly(D,L-lactide) (PLA) were prepared and then exposed to either acidified PBS (pH 2.5) or MeOH:H2O (50:50, v/v) medias during a 7-day IVR test using continuous flow-through (CFT) cell dissolution. The amount of drug released from the polymer matrix during the 7-day IVR test was monitored by online-ultraviolet spectroscopy (UV) and HPLC-UV. After that period, intact implants and radial sections of implants were analyzed by DESI-MSI with ion mobility spectrometry. The active ingredient along with impurities and contaminants were used to generate chemical maps before and after exposure to the release medias. RESULTS: Bi-phasic release profiles were observed for implants during IVR release using both medias. During the second phase of release, implants exposed to PBS, pH 2.5, released the entecavir faster than the implants exposed to MeOH:H2O (50:50, v/v). Radial images of the polymer interior show that entecavir is localized along the central core of the implant after exposure to MeOH:H2O (50:50, v/v) and that the drug is more uniformly distributed throughout the implant after exposure to acidified PBS (pH 2.5). CONCLUSIONS: DESI-MSI coupled with ion mobility analysis produced chemical images of the drug distribution on the exterior and interior of cylindrical polymeric implants before and after exposure to various release medias. These results demonstrated the utility of this technique for rapid characterization of drug and impurity/degradant distribution within polymeric implants with direct implications for formulation development as well as analytical method development activities for various solid parenteral and oral dosage forms. These results are especially meaningful since samples were analyzed with essentially no preparative procedures.

USP Apparatus 4: a Valuable In Vitro Tool to Enable Formulation Development of Long-Acting Parenteral (LAP) Nanosuspension Formulations of Poorly Water-Soluble Compounds.

Long-acting or extended release parenteral dosage forms have attracted extensive attention due to their ability to maintain therapeutic drug concentrations over long periods of time and reduce administration frequency, thus improving patient compliance. It is essential to have an in vitro release (IVR) testing method that can be used to assure product quality during routine production as well as predict and understand the in vivo performance of a formulation. The purpose of this work was to develop a discriminatory in vitro release method to guide formulation and process development of long-acting parenteral (LAP) nanosuspension formulations composed of poorly water-soluble drugs (BCS class II). Injectable nanosuspension formulations were developed to serve as test articles for method development. Several different IVR methods were evaluated for their application to the formulation screening and process development including (1) USP apparatus 2, (2) dialysis and reverse dialysis sac, and (3) continuous flow-through cell (USP apparatus 4). Preliminary data shows the promising results to support the utilization of USP 4 over more widely accepted USP 2 and dialysis methods. A combination of more representative in vivo hydrodynamics and ease of maintaining sink conditions yields the USP 4 flow-through cell method a more suitable in vitro release method for nanosuspension-based LAP formulations of poorly water-soluble compounds, such as compounds A and B.

Remarkably Stereospecific Utilization of ATP α,ß-Halomethylene Analogues by Protein Kinases.

ATP analogues containing a CXY group in place of the α,ß-bridging oxygen atom are powerful chemical probes for studying ATP-dependent enzymes. A limitation of such probes has been that conventional synthetic methods generate a mixture of diastereomers when the bridging carbon substitution is nonequivalent (X ≠ Y). We report here a novel method based on derivatization of a bisphosphonate precursor with a d-phenylglycine chiral auxiliary that enables preparation of the individual diastereomers of α,ß-CHF-ATP and α,ß-CHCl-ATP, which differ only in the configuration at the CHX carbon. When tested on a dozen divergent protein kinases, these individual diastereomers exhibit remarkable diastereospecificity (up to over 1000-fold) in utilization by the enzymes. This high selectivity can be exploited in an enzymatic approach to obtain the otherwise inaccessible diastereomers of α,ß-CHBr-ATP. The crystal structure of a tyrosine kinase Src bound to α,ß-CHX-ADP establishes the absolute configuration of the CHX carbon and helps clarify the origin of the remarkable diastereospecificity observed. We further synthesized the individual diastereomers of α,ß-CHF-γ-thiol-ATP and demonstrated their utility in labeling a wide spectrum of kinase substrates. The novel ATP substrate analogues afforded by these two complementary strategies should have broad application in the study of the structure and function of ATP-dependent enzymes.

Validity of Broselow tape for estimating weight of Indian children.

BACKGROUND & OBJECTIVES: The Broselow tape has been validated in both ambulatory and simulated emergency situations in the United States and is believed to reduce complications arising from inaccurate drug dosing and equipment sizing in paediatric population. This study was conducted to determine the relationship between the actual weight and weight determined by Broselow tape in the Indian children and to derive an equation for determination of weight based on height in the Indian children. METHODS: This cross-sectional study was conducted at a tertiary care hospital in Mumbai, India. The participants' weights were divided into three groups <10 kg, 10-18 kg and >18 kg with a total sample size estimated to be 210 (70 in each group). Using the tape, the measured weight was compared to Broselow-predicted weight and percentage weight was calculated. Accuracy was defined as agreement on Broselow colour-coded zones, as well as agreement within 10 per cent between the measured and Broselow-predicted weights. The resulting data were compared with weights estimated by advanced paediatric life support (APLS) and updated APLS formulae using Pearson's correlation coefficient. RESULTS: The mean percentage differences were -11.78, -17.09 and -14.27 per cent for <10, 10-18 and >18 kg weight-based groups, respectively. The Broselow colour-coded zone agreement was 33.3 per cent in children weighing <10 kg, but only 7.4 per cent in the 10-18 kg group and 33.9 per cent in the >18 kg group. Agreement within 10 per cent was 53.13 per cent for the <10 kg group, but only 21.08 per cent for the 10-18 kg group and 33.9 per cent for the >18 kg group. Application of 10 per cent weight correction factor improved the percentages to 79.2 per cent for the <10 kg category, to 55.70 per cent for the 10-18 kg group and to 61.0 per cent for the >18 kg group. The correlation coefficient between actual weight and weights estimated by Broselow tape (r=0.89) was higher than that between actual weight and weight estimated by APLS method or updated APLS formulae (r=0.68) in 12-60 months age group as well as in >60 months age group (r=0.76). INTERPRETATION & CONCLUSIONS: Broselow weight overestimated weight by >10 per cent in majority of Indian children. The weight overestimation was greater in children belonging to over 18 and 10-18 kg weight groups. Applying 10 per cent weight correction factor to the Broselow-predicted weight may provide a more accurate estimation of actual weight in children attending public hospital. Weights estimated using Broselow tape correlated better with actual weights than those calculated using APLS and updated APLS formulae.

Modafinil Treatment of Cocaine Dependence: A Systematic Review and Meta-Analysis.

BACKGROUND: Currently, there is none FDA-approved medication to treat cocaine dependency. Studies conducted with various medications, including antipsychotics, antidepressants, anticonvulsants, and others, revealed inconsistent results. OBJECTIVES: To meta-analytically investigate the efficacy and safety of modafinil in the treatment of cocaine-dependent patients. METHODS: Randomized controlled trials with ≥20 subjects comparing the numerical therapeutic outcomes of modafinil with placebo were identified in databases, such as PUBMED, psycINFO, EMBASE, and Clinicaltrials.gov. Relevant data on efficacy and safety were extracted. Relative risk (RR) and standardized mean difference were applied for reporting dichotomous and continuous outcomes respectively. Random effects, subgroup, and meta-regression analyses were conducted to further explore the results and evaluate for any moderators. RESULTS: In total, 11 studies (participants = 896, duration = 6.7 ± 1.9 weeks) comparing modafinil with placebo were systematically analyzed, which indicated that modafinil was not superior to placebo in improving the treatment retention rate (studies = 11, participants = 891, RR = 1.030, 95% CI = 0.918-1.156, p = .613). Similarly, data from 7/11 studies did not evidence superiority of modafinil in achieving cocaine abstinence (participants = 696, RR = 1.259, 95% CI = 0.813-1.949, p = .302). However, subgroup analysis of six studies conducted in the United States demonstrated superiority of modafinil in cocaine abstinence rate (studies = 6, participants = 669, 95% CI = 1.027-2.020, p = 0.035). In addition, no evidence suggested modafinil-related discontinuation or specific adverse events than placebo. CONCLUSIONS: Overall, there is no evidence to conclude superiority of modafinil in increasing cocaine abstinence and treatment retention rate. However, promising result in subgroup analysis of cocaine abstinence, secondary outcomes, and good safety profile urged the need of larger studies to derive more conclusive results.

Role of purinergic P2X4 receptors in regulating striatal dopamine homeostasis and dependent behaviors.

Purinergic P2X4 receptors (P2X4Rs) belong to the P2X superfamily of ion channels regulated by ATP. We recently demonstrated that P2X4R knockout (KO) mice exhibited deficits in sensorimotor gating, social interaction, and ethanol drinking behavior. Dopamine (DA) dysfunction may underlie these behavioral changes, but there is no direct evidence for P2X4Rs' role in DA neurotransmission. To test this hypothesis, we measured markers of DA function and dependent behaviors in P2X4R KO mice. P2X4R KO mice exhibited altered density of pre-synaptic markers including tyrosine hydroxylase, dopamine transporter; post-synaptic markers including dopamine receptors and phosphorylation of downstream targets including dopamine and cyclic-AMP regulated phosphoprotein of 32 kDa and cyclic-AMP-response element binding protein in different parts of the striatum. Ivermectin, an allosteric modulator of P2X4Rs, significantly affected dopamine and cyclic AMP regulated phosphoprotein of 32 kDa and extracellular regulated kinase1/2 phosphorylation in the striatum. Sensorimotor gating deficits in P2X4R KO mice were rescued by DA antagonists. Using the 6-hydroxydopamine model of DA depletion, P2X4R KO mice exhibited an attenuated levodopa (L-DOPA)-induced motor behavior, whereas ivermectin enhanced this behavior. Collectively, these findings identified an important role for P2X4Rs in maintaining DA homeostasis and illustrate how this association is important for CNS functions including motor control and sensorimotor gating. We propose that P2X4 receptors (P2X4Rs) regulate dopamine (DA) homeostasis and associated behaviors. Pre-synaptic and post-synaptic DA markers were significantly altered in the dorsal and ventral striatum of P2X4R KO mice, implicating altered DA neurotransmission. Sensorimotor gating deficits in P2X4R KO mice were rescued by DA antagonists. Ivermectin (IVM), a positive modulator of P2X4Rs, enhanced levodopa (L-DOPA)-induced motor behavior. These studies highlight potential interactions between P2X4Rs and DA system.

Macrophages: A review of their role in wound healing and their therapeutic use.

Macrophages are mononuclear phagocytes established during embryogenesis and derived from the yolk sac or the fetal liver but also recruited from the blood and bone marrow under proliferative inflammatory conditions (such as tissue repair). Most importantly, they take on distinct phenotypes and functions crucial to healing upon localization in the wound. The objective of this review is to summarize recent findings in regard to the cellular mechanisms of macrophages and chronic wounds. Advances in the potential use of macrophage therapy have arisen based, in part, on the fact that early recruitment of macrophages is critical to wound healing. Higher quality evidence is needed to support the use of macrophage therapy for chronic wound types, as is a better understanding of the signaling related to macrophage polarization, activation of macrophages, and their effect of mechanisms of repair. An evaluation of the currently available research on mechanism of action may lead to a better understanding of the signaling processes of the many macrophage phenotypes, as well as their roles and outcomes in wound healing, which could then guide the development and eventual widespread use of macrophage therapies.

The Effect of Patellar Thickness on Intraoperative Knee Flexion and Patellar Tracking in Patients With Arthrofibrosis Undergoing Total Knee Arthroplasty.

BACKGROUND: We evaluated the intraoperative effect of patellar thickness on intraoperative passive knee flexion and patellar tracking during total knee arthroplasty (TKA) in patients with preoperative arthrofibrosis and compared them to patients with normal preoperative range of motion (ROM) documented in a prior study. METHODS: Routine posterior cruciate ligament-retaining TKA was performed in a total of 34 knees, 23 with normal ROM and 11 with arthrofibrosis, defined as ≤100° of passive knee flexion against gravity under anesthesia. Once clinical balance and congruent patellar tracking were established, custom trial patellar components thicker than the standard trial by 2-mm increments (2-8 mm) were sequentially placed and trialed. Passive flexion against gravity was recorded using digital photograph goniometry. Gross mechanics of patellofemoral tracking were visually assessed. RESULTS: On average, passive knee flexion decreased 2° for every 2-mm increment of patellar thickness (P < .0001), which was similar to patients with normal preoperative ROM. In addition, increased patellar thickness had no gross effect on patellar subluxation and tilt in patients with arthrofibrosis as well as those with normal ROM. CONCLUSIONS: Patellar thickness had a modest effect on intraoperative passive flexion and no effect on patellar tracking in patients with arthrofibrosis undergoing TKA. There was no marked difference in intraoperative flexion and patellar tracking between patients with arthrofibrosis and patients with normal preoperative ROM.