Repetitive Injections Research Articles

Continuous Increase of Efficacy under Repetitive Injections of Botulinum Toxin Type/A beyond the First Treatment for Adult Spastic Foot Drop.

The objective of this study was to quantify the increase in efficacy during the first four cycles of treatment with botulinum toxin type/A (BoNT/A) in 24 free-walking BoNT/A naïve adult patients with post-stroke hemispasticity and spastic foot drop. Patients were followed over 390 days and received five injections of 800 U aboBoNT/A every three months. Patients assessed the treatment effect at eight visits using a global assessment scale, physicians scored the muscle tone at the ankle joint, measured active and passive ranges of motion (aRoMs, pRoMs) at the knee and ankle joint and determined the distance patients succeeded to walk during a minute. Patients’ assessments significantly (p < 0.006) increased with time and significantly correlated with all parameters measured. The best correlation (r = 0.927; p < 0.0001) was found with the sum of the aRoMs of knee and ankle joint. After one year of treatment outcome measures were better than and significantly correlated with the peak effect of the first injection. This correlation was higher for pRoMs (r = 0.855; p < 0.00001) compared to aRoMs (r = 0.567; p < 0.009). When BoNT/A treatment of the spastic foot in chronic hemispasticity is performed regularly every three months for at least one year, patients will experience a significant increase of benefit beyond the first treatment, but have to learn how to adapt to and use the new degree of freedom induced by the injections.

Possible Therapeutic Options for Complex Regional Pain Syndrome.

Complex regional pain syndrome (CRPS) describes an array of painful conditions that are characterized by continuing regional pain. CRPS comprises severe and inappropriate pain in cases of complete recovery after trauma. Research on the pharmacological treatment of CRPS, however, has not been well investigated. In this study, we compared the pain relief effects of different drugs (URB597, pyrrolidine dithiocarbamate, and hydralazine) in a rat model of chronic post-ischemic pain-induced CRPS. After drug injection, CRPS-induced mechanical allodynia was significantly recovered. After three repetitive drug injections, mechanical sensitivity generally improved as hyper-nociception subsided. Reduced Nav1.7 expression at dorsal root ganglions (DRGs) was observed in the drug treatment groups. Neural imaging analysis revealed decreased neural activity for each drug treatment, compared to vehicle. In addition, treatments significantly reduced IL-1β, IL-6, and TNFα expression in DRGs. These results indicated that drugs could reduce the expression of inflammatory factors and alleviate the symptoms of chronic post-ischemic pain-induced CRPS.

Autologous Micro-Fragmented Adipose Tissue (MFAT) to Treat Symptomatic Knee Osteoarthritis: Early Outcomes of a Consecutive Case Series.

The study aimed to evaluate the short-term clinical effect, therapeutic response rate (TRR%), and therapy safety of a single intra-articular autologous MFAT injection for symptomatic knee OA. Secondly, patient- and pathology-related parameters were investigated to tighten patient selection for MFAT therapy. Sixty-four subjects with symptomatic mild–severe knee OA were enrolled in a single-center trial and received a unilateral (n = 37) or bilateral (n = 27) MFAT injection. After liposuction, the adipose tissue was mechanically processed with the Lipogem® device, which eventually produced 8–10 cc of MFAT. Subjects were clinically assessed by means of the KOOS, NRS, UCLA, and EQ-5D at baseline and 1, 3, 6, and 12 months after injection. Adverse events were recorded at each follow-up timepoint. The TRR was defined according to the OMERACT-OARSI criteria and baseline MRI was scored following the MOAKS classification. The TRR of the index knee was 64% at 3 months and 45% at 12 months after injection. Therapy responders at 12 months improved with 28.3 ± 11.4 on KOOS pain, while non-responders lost −2.1 ± 11.2 points. All clinical scores, except the UCLA, improved significantly at follow-up compared to baseline (p < 0.05). In the bilateral cohort, no difference in baseline scores or TRR was found between the index knee and contralateral knee (n.s.). An inflammatory reaction was reported in 79% of knees and resolved spontaneously within 16.6 ± 13.5 days after MFAT administration. Numerous bone marrow lesions (BML) were negatively correlated with the TRR at 12 months (p = 0.003). The study demonstrated an early clinical improvement but a mediocre response rate of 45% at 12 months after a single intra-articular injection with autologous MFAT. Assessment of bone marrow lesions on MRI can be helpful to increase the therapeutic responsiveness of MFAT up to 70% at 12 months. In comparison to repetitive injection therapies such as cortisone, hyaluronic acid, and PRP, administration of MFAT might become a relevant alternative in well-selected patients with symptomatic knee OA.

Mitigation of analyte loss on metal surfaces in liquid chromatography

The adsorptive loss of acidic analytes in liquid chromatography was investigated using metal frits. Repetitive injections of acidic small molecules or an oligonucleotide were made on individual 2.1 or 4.6 mm i.d. column frits. Losses were observed for adenosine 5′-(α,β-methylene) diphosphate, 2-pyridinol 1-oxide and the 25-mer phosphorothioate oligonucleotide Trecovirsen (GEM91) on stainless steel and titanium frits. Analyte adsorption was greatest at acidic pH due to the positive charge on the metal oxide surface. Analyte recovery increased when a series of injections was performed; this effect is known as sample conditioning. Nearly complete recovery was achieved when the metal adsorptive sites were saturated with the analyte. A similar effect was achieved by conditioning the frits with phosphoric, citric or etidronic acids, or their buffered solutions. These procedures can be utilized to mitigate analyte loss. However, the effect is temporary, as the conditioning agent is gradually removed by the running mobile phase. Metal frits modified with hybrid organic/inorganic surface technology were shown to mitigate analyte-to-metal surface interactions and improve recovery of acidic analytes. Quantitative recovery of a 15–35 mer oligodeoxythymidine mixture was achieved using column hardware modified with hybrid surface technology, without a need for column conditioning prior to analysis.

Investigation of the Effects of Intra-articular Tranexamic Acid on Intact Cartilage Tissue and Cartilage Formation in Osteochondral Defects of the Rabbit Knee: An Experimental Study.

BackgroundIn this study, the effects of tranexamic acid (TXA) and saline on intact cartilage and the recovery of experimental osteochondral lesions following microfracture in a rabbit model were compared.MethodsTwenty adult rabbits were divided into four groups (1A, 1B, 2A, and 2B) based on with or without TXA use and microfracture. In addition, these groups were categorized into two different subgroups based on the use of TXA in Groups 1 and 2 (Groups A and B). Full-thickness cartilage defects were created on the weight-bearing surface of the medial femoral condyles unilaterally in Group 2 for the effect of TXA or saline on healthy cartilage tissue while a repetitive injection was applied in Group 1 for the effect of TXA or saline on intact cartilage. A single dose of 10 mg/kg TXA was injected into the knee joints of Group A and 10 mg/kg 0.9% saline solution injected in Group B for three consecutive days. All animals were sacrificed for the extraction of the medial condyles for histologic evaluation eight weeks after surgery. The International Cartilage Repair Society (ICRS) II scoring system was used for histologic evaluation.ResultsNo complications or adverse effects related to surgery were observed in all rabbits. All ICRS II parameters were similar in the TXA and saline solution groups in the intact cartilage group except for chondrocyte clustering, formation of a tidemark, subchondral bone abnormalities, and mid/deep zone assessment. Moreover, these parameters were higher in the saline solution group in the cartilage group, but no significant difference was observed in the TXA group in the intact cartilage group. All ICRS II parameters were higher in the saline solution group than in the TXA group in the microfracture group, but no significant difference was observed in the TXA group in the microfracture group except for inflammation, which was similar in the TXA and saline solution groups in the microfracture group.ConclusionWe found that intra-articular TXA administration did not have a negative impact on healthy cartilage tissue and cartilage transformation and proliferation as compared to the saline infusion.

Comparison of the effects of corticosteroid and hyaluronic acid-carboxymethylcellulose solution on selective nerve root block for lumbar radiculopathy: A prospective, double-blind, randomized controlled clinical trial.

Selective nerve root block (SNRB) was shown to effectively control radiating pain and reduce the need for surgical intervention. However, repetitive injections may trigger corticosteroid-induced side effects (hypercorticism, hyperglycemia, or fluid retention). This study aims to compare the potency of hyaluronic acid-carboxymethylcellulose (HA-CMC) solution versus that of corticosteroids regarding lower leg radiating pain (LLRP) improvement and functional outcome. Among 128 patients, 44 patients who complain about having LLRP due to lumbar spinal stenosis and do not have neurological symptoms requiring surgery were enrolled for this study. Group A with 22 patients injected with cocktail A (local anesthetics and corticosteroid) and group B with 22 patients injected with cocktail B (local anesthetics and HA-CMC). Outcome measures were the visual analog scale (VAS), Oswestry Disability Index (ODI), and short form-36 (SF-36). All patients were asked to fill in the questionnaires during the follow-up assessment period at 3days, 7days, 2weeks, 6weeks, and 12weeks. In all time periods, there were no statistical differences between the two groups for VAS scores and VAS improvement over time, ODI scores and ODI improvement over time, and SF-36 PCS scores and SF-36 mental component score scores. Additionally, the 95% confidence interval of the difference in VAS score improvement between the 2 groups in all time periods was within VAS 5.0, which is the minimum clinically relevant difference. Considering the adverse effects of corticosteroids, and the similar LLRP improvements, functional outcome, and quality of life, the HA-CMC solution may be an alternative option to corticosteroid in SNRB.

Study on the effect of pore-scale heterogeneity and flow rate during repetitive two-phase fluid flow in microfluidic porous media

Various energy recovery, storage, conversion and environmental operations may involve repetitive fluid injection and thus, cyclic drainage–imbibition processes. We conducted an experimental study for which polydimethylsiloxane (PDMS)-based micromodels were fabricated with three different levels of pore-space heterogeneity (coefficient of variation, where COV = 0, 0.25 and 0.5) to represent consolidated and/or partially consolidated sandstones. A total of 10 injection-withdrawal cycles were applied to each micromodel at two different flow rates (0.01 and 0.1 ml min −1 ). The experimental results were analysed in terms of flow morphology, sweep efficiency, residual saturation, the connection of fluids and the pressure gradient. The pattern of the invasion and displacement of the non-wetting fluid converged more readily in the homogeneous model (COV = 0) as the repetitive drainage–imbibition process continued. The overall sweep efficiency converged between 0.4 and 0.6 at all tested flow rates, regardless of different flow rates and COV in this study. In contrast, the effective sweep efficiency was observed to increase with higher COV at the lower flow rate, while that trend became reversed at the higher flow rate. Similarly, the residual saturation of the non-wetting fluid was largest at COV = 0 for the lower flow rate, but it was the opposite for the higher flow-rate case. However, the Minkowski functionals for the boundary length and connectedness of the non-wetting fluid remained quite constant during repetitive fluid flow. Implications of the study results for porous media-compressed air energy storage (PM-CAES) are discussed as a complementary analysis at the end of this paper. Supplementary material: Figures showing the distribution of water (Fig. S1) and oil (Fig. S2) at the end of each drainage and imbibition step in different microfluidic pore-network models are available at https://doi.org/10.6084/m9.figshare.c.5276814 Thematic collection: This article is part of the Energy Geoscience Series available at: https://www.lyellcollection.org/cc/energy-geoscience-series

Insulin injections inhibits PTZ-induced mitochondrial dysfunction, oxidative stress and neurological deficits via the SIRT1/PGC-1α/SIRT3 pathway

With an associated 20% death risk, epilepsy mainly involves seizures of an unpredictable and recurrent nature. This study was designed to evaluate the neuroprotective effects and underlying mechanisms of insulin on mitochondrial disruption, oxidative stress, cell apoptosis and neurological deficits after epilepsy seizures. Mice were exposed to repetitive injections of pentylenetetrazol at a dose of 37 mg per kg. The influence of insulin was assessed by many biochemical assays, histopathological studies and neurobehavioral experiments. The administration of insulin was proven to increase the latency of seizures while also decreasing their intensity. It also caused a reversal of mitochondrial dysfunction and ameliorated oxidative stress. Additionally, insulin pretreatment upregulated Bcl-2, downregulated Bax, and then played a neuroprotective role against hippocampal neuron apoptosis. Furthermore, when insulin was administered, SIRT1/PGC-1α/SIRT3 signals were activated, possibly due to the fact that insulin's neuroprotective and anti-mitochondrial damage characteristics added to its observed antiepileptic functions. Finally, insulin treatment is thus extremely valuable for effecting improvements in neurological functions, as has been estimated in a series of functional tests. In conclude, the results of this study consequently demonstrate insulin to have significant potential for future application in epilepsy management.

Selective denervation of the corrugator supercilii muscle for the treatment of idiopatic trigeminal neuralgia purely paroxysmal distributed in the supraorbital and suprathrochlear dermatomes

IntroductionIdiopatic trigeminal neuralgia purely paroxysmal (ITNp) distributed in the supraorbital and suprathrochlear dermatomes (SSd), refractory to conventional treatments have been linked to the hyperactivity of the corrugator supercilii muscle (CSM). In these patients, the inactivation of the CSM via botulinum toxin type A (BTA) injections has been proven to be safe and effective in reducing migraine burden. The main limitation of BTA is the need of repetitive injections and relative high costs. Based on the study of the motor innervation of the CSM, we describe here an alternative approach to improve these type of migraines, based on a minimally invasive denervation of the CSM.Materials and methodsMotor innervation and feasibility of selective CSM denervation was first studied on fresh frozen cadavers. Once the technique was safely established, 15 patients were enrolled. To be considered eligible, patients had to meet the following criteria: positive response to BTA treatment, migraine disability assessment score > 24, > 15 migraine days/month, no occipital/temporal trigger points and plausible reasons to discontinue BTA treatment. Pre- and post- operative migraine headache index (MHI) were compared, and complications were classified following the Clavien-Dindo classification (CDC).ResultsFifteen patients (9 females and 6 males) underwent the described surgical procedure. The mean age was 41 ± 10 years. Migraine headache episodes decreased from 24 ± 4 day/month to 2 ± 2 (p < 0.001) The MHI decreased from 208 ± 35 to 10 ± 11 (p < 0.001). One patient (7%) had a grade I complication according to the CDC. No patient needed a second operative procedure.ConclusionsOur findings suggest that the selective CSM denervation represents a safe and minimally invasive approach to improve ITNp distributed in the SSd associated with CSM hyperactivation.Trial registrationThe data collection was conducted as a retrospective quality assessment study and all procedures were performed in accordance with the ethical standards of the national research committee and the 1964 Helsinki Declaration and its later amendments.

Learning and synaptic plasticity in 3D bioengineered neural tissues

Though neuroscientists have historically relied upon measurement of established nervous systems, contemporary advances in bioengineering have made it possible to design and build artificial neural tissues with which to investigate normative and diseased states [1–5] however, their potential to display features of learning and memory remains unexplored. Here, we demonstrate response patterns characteristic of habituation, a form of non-associative learning, in 3D bioengineered neural tissues exposed to repetitive injections of current to elicit evoked-potentials (EPs). A return of the evoked response following rest indicated learning was transient and partially reversible. Applying patterned current as massed or distributed pulse trains induced differential expression of immediate early genes (IEG) that are known to facilitate synaptic plasticity and participate in memory formation [6,7]. Our findings represent the first demonstration of a learning response in a bioengineered neural tissue in vitro.

Dose Tapering of Biologics in Patients with Psoriasis: A Scoping Review

IntroductionBiologics serve as a cornerstone in psoriasis treatment, with low disease activity or sometimes even clinical remission as a realistic treatment outcome. So far, it is unclear whether biologics should be tapered when this target is achieved. Dose tapering could offer potential benefits by decreasing side effects, the burden of repetitive injections and costs of biological therapy. However, clinical guidelines on dose tapering of biologicals in psoriasis patients are lacking. This scoping review was conducted to provide an overview of the current literature on dose tapering and offer guidance for clinicians in daily clinical practice.MethodsDose tapering is defined as the administration of a lower dose per administration, or the prolongation of the regular dose interval, after initial treatment according to the standard dosing. Four electronic databases (PubMed, EMBASE, Cochrane, and Web of Science) were systematically searched for literature on tapering of biologics in adult patients with psoriasis from 1 January 2000.ResultsWe included 19 original articles on biologic tapering in psoriasis patients: four randomized controlled trials and 15 observational studies. Tapering eligibility criteria, tapering strategies, tapering outcomes, and recapture of response after relapse were assessed. Furthermore, the available evidence on possible predictors for successful tapering, and the effect of tapering on safety, quality of life and costs is summarized. The definition of low disease activity as a measure for tapering eligibility varied widely. Beside tapering criteria, tapering strategies were also heterogeneous. Of note, quality-of-life measurements were barely integrated in the evaluation of tapering outcomes. Literature on regaining response after relapse due to tapering was limited, but restored remission has been described. The included studies did not proclaim a significant effect of tapering on the occurrence of (severe) adverse events. Even though cost savings have been reported, no proper cost-effectiveness analysis has been conducted yet.ConclusionBiologic tapering seems to be effective and safe in psoriasis patients with stable low disease activity or clinical remission. Available data on biologic dose tapering in patients with psoriasis are promising, but more research is warranted to fill the current gaps in knowledge.Supplementary InformationThe online version contains supplementary material available at 10.1007/s40265-020-01448-z.

Growth Performance and Clinicopathological Analyses in Lambs Repetitively Inoculated with Aluminum-Hydroxide Containing Vaccines or Aluminum-Hydroxide Only

Simple SummaryAluminum-hydroxide is an effective vaccine adjuvant used in most commercial sheep vaccines. It facilitates the establishment of a robust immune response against the vaccine antigen. During the first decade of the 21st century, repetitive injections with vaccines containing aluminum-based adjuvants were proposed to be linked to a progressive wasting syndrome in sheep. The aim of this work was to analyze several clinicopathological parameters, including growth performance, clinical data, and histopathological observations in lambs intensively injected with aluminum-containing vaccines, aluminum-hydroxide only, or a saline solution as control. Although aluminum-hydroxide was linked to chronic inflammatory reactions at the injection site and the development of behavioral changes in sheep, the results presented here indicate that injected aluminum-hydroxide, either alone or in combination with vaccine antigens, is not enough to induce relevant changes in the parameters studied. Other factors such as sex, breed, age, production system, diet or climate conditions could play a role in the development of the previously described wasting syndrome.Aluminum (Al) hydroxide is an effective adjuvant used in sheep vaccines. However, Al-adjuvants have been implicated as potential contributors to a severe wasting syndrome in sheep—the so-called ovine autoimmune-inflammatory syndrome induced by adjuvants (ASIA syndrome). This work aimed to characterize the effects of the repetitive injection of Al-hydroxide containing products in lambs. Four flocks (Flocks 1–4; n = 21 each) kept under different conditions were studied. Three groups of seven lambs (Vaccine, Adjuvant-only, and Control) were established in each flock. Mild differences in average daily gain and fattening index were observed, indicating a reduced growth performance in Vaccine groups, likely related to short-term episodes of pyrexia and decreased daily intake. Clinical and hematological parameters remained within normal limits. Histology showed no significant differences between groups, although there was a tendency to present a higher frequency of hyperchromatic, shrunken neurons in the lumbar spinal cord in the Adjuvant-only group. Although Al-hydroxide was linked to granulomas at the injection site and behavioral changes in sheep, the results of the present experimental work indicate that injected Al-hydroxide is not enough to fully reproduce the wasting presentation of the ASIA syndrome. Other factors such as sex, breed, age, production system, diet or climate conditions could play a role.

Cooling of The Heated Wall Surface by Liquid Film during A Repetitive Pulsed Injection of Liquid Jet

Cooling of The Heated Wall Surface by Liquid Film during A Repetitive Pulsed Injection of Liquid Jet

Alpha lipoic acid attenuates evoked and spontaneous pain following surgical skin incision in rats

ABSTRACT Our previous studies have implicated CaV3.2 isoform of T-type Ca2+ channels (T-channels) in the development of postsurgical pain. We have also previously established that different T-channel antagonists can alleviate in vivo postsurgical pain. Here we investigated the analgesic potential of another T-channel blocker and endogenous antioxidant molecule, α-lipoic acid (ALA), in a postsurgical pain model in rats. Our in vivo results suggest that single and repetitive intraperitoneal injections of ALA after surgery or preemptively, significantly reduced evoked mechanical hyperalgesia following surgical paw incision. Furthermore, repeated preemptive systemic injections of ALA effectively alleviated spontaneous postsurgical pain as determined by dynamic weight-bearing testing. We expect that our preclinical study may lead to further investigation of analgesic properties and mechanisms of analgesic action of ALA in patients undergoing surgery.

Intratympanal administration of lidocaine in the management of Ménière’s Disease

Background Ménière’s Disease (MD) is a chronic condition where patients suffer recurrent vertigo attacks. Evidence for treatment concepts are to this date low. Aims/objective To evaluate the therapeutic effect of intratympanic lidocaine injections to reduce the number of attacks. Methods Twenty patients diagnosed with definitive MD that were treated with 34 intratympanic lidocaine injections were included. Main outcome measures were the number of vertigo attacks in the previous four weeks, the attack free period and the subjective improvement of the condition. Results Mean follow up after first lidocaine injection was 25.3 months (±22.2; range 1.9–79.7). Patients expressed subjective improvement in overall situation, vertigo, and aural fullness. The number of vertigo attacks before each assessment decreased from 7.1 (±5.9; range 2–20) per months at baseline to 1.9 (±3.8; range 0–15). 25% of the patients suffered no further attacks, the other patients had an average attack free period of 7.8 months (±15.4; range 0.2–58.4). Hearing thresholds remained unaffected. Repetitive injections proved effective. Conclusion and significance Intratympanic lidocaine is an effective nonsurgical and non-ablative therapy for MD. When patients experience an increase of attacks repetitive injections promise improvement.

Intraneural Application of microRNA-1 Mimetic Nucleotides Does Not Resolve Neuropathic Pain After Chronic Constriction Injury in Rats.

BackgroundAlterations of the expression of microRNAs (miRNAs) in chronic pain models seem to play a crucial role in the development of neuropathic pain, with microRNA-1 (miR-1) being of particular interest. Recently, we were able to show that decreased miR-1 levels were associated with increased expression of brain-derived neurotrophic factor (BDNF) and Connexin 43 (Cx43). We hypothesized that miR-1 mimetic nucleotides could alleviate neuropathic pain caused by chronic constriction injury in rats.MethodsMiR-1 mimetic nucleotides were evaluated for effectiveness, functionality, and intracellular stability by transfecting human glioblastoma cells (U-87 MG). In vivo transfection with miR-1 mimics and corresponding scrambled miRNAs serving as control was performed by repetitive injection (days 0, 3, and 7) into the sciatic nerve following chronic constriction injury (CCI) in rats. Quantitative PCR was used to measure miR-1 content. Cx43 expression was determined by Western blot analysis. Effects on neuropathic pain were assessed by detecting paw withdrawal thresholds using an automated filament application.ResultsTransfection of miR-1 mimics was confirmed in U-87 MG cells, with miR-1 content being increased significantly after 48 h and after 96 h (p<0.05). Effective downregulation of Cx43 expression was observed 48 and 96 h after transfection (−44 ± 0.07% and −40 ± 0.11%; p<0.05). In vivo, repetitive transfection with miR-1 mimetic nucleotides led to a 17.9-fold (± 14.2) increase of miR-1 in the sciatic nerve. However, the protein expression of Cx43 in sciatic nerves as well as paw withdrawal thresholds for mechanical stimulation was not significantly increased 10 days after chronic constriction injury.ConclusionWhile transfection with miR-1 mimics effective reduces Cx43 expression in vitro and restores miR-1 after CCI, we did neither observe altered levels of Cx43 protein level in nerves nor a beneficial effect on mechanical allodynia in vivo, most likely caused by insufficient Cx43 suppression.

Ratiometrically Designed Nanocarrier to Impact Major Cancer Pathways for Effective Pancreatic Cancer Treatment

To achieve secured in vivo drug synergy in stroma-rich pancreatic cancer(PDAC) is not an easy task. Ji and Liu et al. demonstrate the rational development of a ratiometrically designed nanocarrier to co-package a CDK4/6 cell cycle inhibitor palbociclib(PAL) plus an autophagy inhibitor hydroxychloroquine(HCQ) for efficient PDAC treatment. The lead formulation was obtained using a computer software aided in vitro screening, followed by a remote drug co-import into a lipid-coated mesoporous silica nanoparticle. The ratiometric nanocarrier led to the synchronized pharmacokinetic(PK) profile and effective intratumoral buildup of the drug pair post intravenous injection, which otherwise exhibited distinctly different biodistribution characteristics. The treatment using PAL/HCQ co-delivery nanoparticles yielded the most effective shrinkage of PDAC in subcutaneous and orthotopic PANC1 mouse models. The mechanistic investigation also demonstrated the activation of anti-apoptosis pathway after repetitive nanoparticle injection in mice, which promoted the authors to introduce a small molecule anti-apoptosis inhibitor to further improve the performance of their already potent nanoparticle in the PDAC mouse model. This work has been published online in Nature Communications on August 25, 2020.

The Assessment of Steroid Injections as a Potential Risk Factor for Osteochondral Lesions in Children with Juvenile Idiopathic Arthritis.

Intra-articular corticosteroid injections (IACIs) are frequently used to suppress local inflammation, that is, in children with juvenile idiopathic arthritis (JIA). While systemic high-dosage corticosteroids are known to trigger osteonecrosis and result in osteochondral (OC) lesions, the effect of IACIs on joint cartilage and subchondral bone remains unclear. This study was conceived to analyze the coincidence of IACI and the subsequent manifestation of osteochondral lesions in a large cohort of pediatric JIA patients. Retrospective data assessment and comparative analysis of skeletally immature JIA patients treated with IACIs between 1993 and 2017. A total of 280 JIA patients were included in the analysis, the majority were girls (64%). Osteochondral lesions were present in 16 patients (5.7%) at a mean age of 10.7 years (range 4-14 years) and appeared on average after 63-month duration of disease. The majority was present at atypical locations such as the lateral femoral condyle. Multivariable analysis using cox regression showed that steroid injections were a risk factor to develop an OC lesion (hazard ratio [95%CI] for number of steroid injections per year, 8.20 [3.18, 21.16]). Pediatric patients with JIA show a relatively high incidence of osteochondritic lesions, which present at an early age and in rather atypical locations and repetitive steroid injection need to be considered an associated risk factor.

Spontaneous and artificial void wave propagation beneath a flat-bottom model ship

Although the practical use of bubbly drag reduction for marine vessels has begun to spread, it is unclear how bubbles migrate along spatially developing turbulent boundary layers. We measured the spatiotemporal distribution of the local void fraction beneath a 4-m-long fully transparent flat-bottom model ship towed in a 100-m-long water tank with a ship speed of up to 3.00 m/s. Bubbles were injected with both constant and periodically fluctuated air flow rates into the turbulent boundary layers. With constant flow rates, 2–5-mm bubbles caused spontaneous void waves, i.e., quasiperiodic fluctuation of the local void fraction, standing at 4–8 Hz. When repetitive bubble injection, which formed artificial void waves downstream, was applied, void waves propagated at 47%–53% of the ship speed. During the propagation, we found the apparent diffusion coefficient of the void wave taking values down to 10−4 m2/s and even negative values when the repetition frequency was set lower than the spontaneous frequency of void waves. This indicates that the void waves persist for several tens of meter in application to ship hulls.

Abstract 6241: PAX8-directed nanotherapeutics for high-grade serous ovarian carcinoma

Abstract Objective: High-grade serous ovarian cancer (HGSOC) is the most common epithelial ovarian cancer subtype. Targeted therapy for HGSOC is challenging because the disease is characterized by copy number variation rather than recurrent somatic mutations. HGSOC displays well-conserved epigenetic features such as expression of transcription factor PAX8. We propose employing epigenetic therapies that capitalize on interactions between PAX8 and specific DNA-binding sites to develop potential therapeutic approaches to target HGSOC. Our hypothesis is to use a biomimetic approach wherein PAX8 is induced to transcribe an ectopically transfected CRISPR-base editor (BE)-guide RNA (gRNA) plasmid containing a PAX8 binding site in its promoter. The gRNA will impart a dominant-negative allele of Polo Like Kinase 1 (PLK1) which has been shown to be synergistically lethal with deficient tp53 in cancer cells. In the presence of PAX8, the plasmid will be transcribed, while in the absence of PAX8, the plasmid is degraded, with minimal toxicity observed in healthy cells. Methods: PAX8-expressing ovarian cancer cell lines including COV362, Kuramochi, OVCAR8 and OVSAHO or PAX8-negative control cell lines including JEG3, MCF-7, HeLa and HEK293T were transfected with polyplexes bearing the plasmid of interest. Polyplex diameter, polydispersity indices, and surface zeta potentials were measured on a Malvern Zetasizer. Polyplexes were imaged for uptake and functionality using fluorescence microscopy and Amnis ImageStream. Polyplex toxicity was assessed in vitro using cell viability assays. Preliminary in vivo experiments to demonstrate luciferase plasmid-bearing polyplexes have been performed in NOD-SCID mice. To monitor in vivo transfection efficiencies, we will deliver fluorescently labeled plasmids or luciferase-encoding plasmids to test bio-distribution and pharmacokinetics. Results: We have synthesized sub-200nm (diameter) polyplexes using the polyamine PPLG-g-azidopropylamine (PPLG) and BE or gRNA plasmids. Using -/-PLK1 gRNA, we observed that the BE and the gRNA can be efficiently packaged into two distinct polymeric nanoplexes and co-delivered to ovarian cancer cells or control cells to impart a dominant-negative mutant of PLK1, which is also synthetically lethal with mutated tp53, as observed from cancer cell death compared to controls. Ongoing work includes repetitive polyplex injections in vitro and in vivo, quantifying percentage of total sequencing reads with target base pair conversions after treatment, determination of plasmid loading efficiency, and testing gRNAs against other targets for efficacy in ovarian cancer targeting. Conclusion: Well-defined lineage transcription factors have the potential to serve as novel targets for gene-editing therapies in ovarian cancer and other malignancies. Combining nanotechnology and gene editing can improve specificity toward ovarian cancer cells as well as incorporate precision therapy aimed at the underlying genetic architecture of this disease. Citation Format: Akshaya Chandrasekaran, Mariam Ahmed, Wade Wang, Paula T. Hammond, Kevin M. Elias. PAX8-directed nanotherapeutics for high-grade serous ovarian carcinoma [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 6241.