Leg Contracture Research Articles

Leg compliance is required to explain the ground reaction force patterns and speed ranges in different gaits.

Two simple models, vaulting over stiff legs and rebounding over compliant legs, are employed to describe the mechanics of legged locomotion. It is agreed that compliant legs are necessary for describing running and that legs are compliant while walking. Despite this agreement, stiff legs continue to be employed to model walking. Here, we show that leg compliance is necessary to model walking and, in the process, identify the principles that underpin two important features of legged locomotion: First, at the same speed, step length, and stance duration, multiple gaits that differ in the number of leg contraction cycles are possible. Among them, humans and other animals choose a gait with M-shaped vertical ground reaction forces because it is energetically favored. Second, the transition from walking to running occurs because of the inability to redirect the vertical component of the velocity during the double stance phase. Additionally, we also examine the limits of double spring-loaded pendulum (DSLIP) as a quantitative model for locomotion, and conclude that DSLIP is limited as a model for walking. However, insights gleaned from the analytical treatment of DSLIP are general and will inform the construction of more accurate models of walking.

Volkmanns ischemic contracture with impaired vascularity managed by minimally invasive soft tissue release and capsulotomy A rehabilitation perspective

Volkmanns ischemic leg contracture is severe and debilitating, arising from prolonged ischemia of the lower limb musculature.

Modeling ultra-high dose rate electron and proton FLASH effect with the physicochemical approach

Objective. A physicochemical model built on the radiochemical kinetic theory was recently proposed in (Labarbe et al ) to explain the FLASH effect. We performed extensive simulations to scrutinize its applicability for oxygen depletion studies and FLASH-related experiments involving both proton and electron beams. Approach. Using the dose and beam delivery parameters for each FLASH experiment, we numerically solved the radiochemical rate equations comprised of a set of coupled nonlinear ordinary differential equations to obtain the area under the curve (AUC) of radical concentrations. Main results. The modeled differences in AUC induced by ultra-high dose rates appeared to correlate well with the FLASH effect. (i) For the whole brain irradiation of mice performed in (Montay-Gruel et al ), the threshold dose rate values for memory preservation coincided with those at which AUC started to decrease much less rapidly. (ii) For the proton pencil beam scanning FLASH of (Cunningham et al ), we found linear correlations between radicals’ AUC and the biological endpoints: TGF-β1, leg contracture and plasma level of cytokine IL-6. (iii) Compatible with the findings of the proton FLASH experiment in (Kim et al ), we found that radicals’ AUC at the entrance and mid-Spread-Out Bragg peak regions were highly similar. In addition, our model also predicted ratios of oxygen depletion G-values between normal and UHDR irradiation similar to those observed in (Cao et al ) and (El Khatib et al ). Significance. Collectively, our results suggest that the normal tissue sparing conferred by UHDR irradiation may be due to the lower degree of exposure to peroxyl and superoxide radicals. We also found that the differential effect of dose rate on the radicals’ AUC was less pronounced at lower initial oxygen levels, a trait that appears to align with the FLASH differential effect on normal versus tumor tissues.

Hereditary Spastic Paraparesis presenting as a Cerebral Palsy Mimic via Telemedicine (P13-9.009)

<h3>Objective:</h3> N/A <h3>Background:</h3> Cerebral palsy (CP) manifests after a perinatal injury, but symptoms can progress with age. A family history of CP phenotype or early progression should alert the clinician to potential CP mimics like the hereditary spastic paraplegias (HSPs), a heterogeneous group of conditions with representatives of all modes of genetic inheritance. <h3>Design/Methods:</h3> N/A <h3>Results:</h3> The patient was born at full term with no perinatal complications. He had delayed motor development, beginning to walk at 2 years of age, and had learning disability requiring modified classes in school. Gait difficulties became apparent in adolescence, progressing to being wheelchair bound in adulthood. He presented to our clinic at age 48 carrying a diagnosis of CP, with bilateral leg spasticity and urinary urgency/incontinence. On camera, he was sitting with leg contractures and dependent edema. No associated oculomotor, facial, or arm weakness, no ataxia or tremor, and no speech or vision abnormalities were detected. Neither of his parents or his nine siblings (7 sisters and 2 brothers) had similar symptoms. He did report having a maternal uncle and nephew with a similar phenotype. MRI brain and thoracic spine were obtained but were unremarkable. Adrenomyeloneuropathy (AMN) was considered but laboratory and genetic testing were not revealing. A genetic panel for hereditary spastic paraplegias was ordered, detecting a pathogenic heterozygous variant, SPAST c.1496G&gt;A (p.Arg499His), causative for SPG4. <h3>Conclusions:</h3> This case highlights the incomplete penetrance of SPG4 and supports the concept of female carriers of SPG4 being less penetrant, as none of his 7 sisters had clinical symptoms. When the presented history and exam are not consistent with a diagnosis of CP, the clinician should search for potential mimics. Inconsistencies include lack of history of perinatal insult, onset of symptoms outside of the perinatal period, and progressive symptoms. In particular, treatable CP mimics, such as adrenomyeloneuropathy, cannot be missed. <b>Disclosure:</b> Dr. Del Papa has nothing to disclose. Dr. Flores-Gonzalez has nothing to disclose. Dr. Margolesky has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Alexion . The institution of Dr. Margolesky has received research support from NeuroNext.

Effects of selenium deficiency on biological results of X-ray and carbon-ion beam irradiation in mice.

The impact of radiation-induced hydrogen peroxide (H2O2) on the biological effects of X-rays and carbon-ion beams was investigated using a selenium-deficient (SeD) mouse model. Selenium is the active center of glutathione peroxidase (GSH-Px), and SeD mice lack the ability to degrade H2O2. Male and female SeD mice were prepared by feeding a torula yeast-based SeD diet and ultrapure water. Thirty-day survival rates after whole-body irradiation, radiation-induced leg contracture, and MRI-based redox imaging of the brain were assessed and compared between SeD and normal mice. Thirty-day lethality after whole-body 5.6 Gy irradiation with X-rays or carbon-ion beams was higher in the SeD mice than in the normal mice, while SeD did not give the notable difference between X-rays and carbon-ion beams. SeD also did not affect the maximum leg contracture level after irradiation with carbon-ion beams, but delayed the leg contraction rate. In addition, no marked effects of SeD were observed on variations in the redox status of the brain after irradiation. Collectively, the present results indicate that SeD slightly altered the biological effects of X-rays and/or carbon-ion beams. GSH-Px processes endogenous H2O2 generated through mitochondrial respiration, but does not have the capacity to degrade H2O2 produced by irradiation.

Exercise Condition Sensing in Smart Leg Extension Machine.

Skeletal muscles require fitness and rehsabilitation exercises to develop. This paper presents a method to observe and evaluate the conditions of muscle extension. Based on theories about the muscles and factors that affect them during leg contraction, an electromyography (EMG) sensor was used to capture EMG signals. The signals were applied by signal processing with the wavelet packet entropy method. Not only did the experiment follow fitness rules to obtain correct EMG signal of leg extension, but the combination of inertial measurement unit (IMU) sensor also verified the muscle state to distinguish the muscle between non-fatigue and fatigue. The results show the EMG changing in the non-fatigue, fatigue, and calf muscle conditions. Additionally, we created algorithms that can successfully sense a user’s muscle conditions during exercise in a leg extension machine, and an evaluation of condition sensing was also conducted. This study provides proof of concept that EMG signals for the sensing of muscle fatigue. Therefore, muscle conditions can be further monitored in exercise or rehabilitation exercise. With these results and experiences, the sensing methods can be extended to other smart exercise machines in the future.

FLASH Proton Pencil Beam Scanning Irradiation Minimizes Radiation-Induced Leg Contracture and Skin Toxicity in Mice.

Simple SummaryDose and efficacy of radiation therapy are limited by the toxicity to normal tissue adjacent to the treated tumor region. Recently, ultra-high dose rate radiotherapy (FLASH radiotherapy) has shown beneficial reduction of normal tissue damage while preserving similar tumor efficacy with electron, photon and scattered proton beam irradiation in preclinical models. Proton therapy is increasingly delivered by pencil beam scanning (PBS) technology, and we therefore set out to test PBS FLASH radiotherapy on normal tissue toxicity and tumor control in vivo in mouse using a clinical proton delivery system. This validation of the FLASH normal tissue-sparing hypothesis with a clinical delivery system provides supporting data for PBS FLASH radiotherapy and its potential role in improving radiotherapy outcomes. Ultra-high dose rate radiation has been reported to produce a more favorable toxicity and tumor control profile compared to conventional dose rates that are used for patient treatment. So far, the so-called FLASH effect has been validated for electron, photon and scattered proton beam, but not yet for proton pencil beam scanning (PBS). Because PBS is the state-of-the-art delivery modality for proton therapy and constitutes a wide and growing installation base, we determined the benefit of FLASH PBS on skin and soft tissue toxicity. Using a pencil beam scanning nozzle and the plateau region of a 250 MeV proton beam, a uniform physical dose of 35 Gy (toxicity study) or 15 Gy (tumor control study) was delivered to the right hind leg of mice at various dose rates: Sham, Conventional (Conv, 1 Gy/s), Flash60 (57 Gy/s) and Flash115 (115 Gy/s). Acute radiation effects were quantified by measurements of plasma and skin levels of TGF-β1 and skin toxicity scoring. Delayed irradiation response was defined by hind leg contracture as a surrogate of irradiation-induced skin and soft tissue toxicity and by plasma levels of 13 different cytokines (CXCL1, CXCL10, Eotaxin, IL1-beta, IL-6, MCP-1, Mip1alpha, TNF-alpha, TNF-beta, VEGF, G-CSF, GM-CSF and TGF- β1). Plasma and skin levels of TGF-β1, skin toxicity and leg contracture were all significantly decreased in FLASH compared to Conv groups of mice. FLASH and Conv PBS had similar efficacy with regards to growth control of MOC1 and MOC2 head and neck cancer cells transplanted into syngeneic, immunocompetent mice. These results demonstrate consistent delivery of FLASH PBS radiation from 1 to 115 Gy/s in a clinical gantry. Radiation response following delivery of 35 Gy indicates potential benefits of FLASH versus conventional PBS that are related to skin and soft tissue toxicity.

Abstract 5349: Proton FLASH radiation spares normal skin and soft tissues of the murine leg from radiation-induced damage while being equipotent with standard proton radiation in controlling sarcoma growth

Abstract Purpose: To investigate the potential normal tissue sparing effects of proton FLASH radiation on skin injury, leg contraction, and soft tissue inflammation while maintaining tumor cell killing efficacy for orthotopic murine fibrosarcoma tumor. Materials and Methods: C3H/HeJ and C57BL/6J mice (n= 6) received 45 Gy of proton FLASH (&amp;gt;85Gy/sec) or conventional radiation (CONV) (1Gy/sec), at the right hind leg. Normal tissue responses were evaluated by recording the skin reaction and the leg contraction over time as acute and chronic macroscopic observations of radiation-induced damage. The skin reactions were recorded using a scoring system of 10 grades, ranging from 0.5 to 3.5, with breakdown of irradiated skin area with moist exudate to be defined as 3. Leg contraction assay examined the extensibility of the leg using a jig and leg contracture was defined as the difference in length between the irradiated and non-irradiated hind leg. Neutrophil infiltration, measured by myeloperoxidase (MPO) activity, and persistent inflammation have been associated with the development of fibrosis, as a long-term effect post radiation. MPO activity was quantified by using intravenously administered luminol and chemiluminescence IVIS imaging at several time points post radiation. We also compared the antitumor efficacy of proton Flash radiation with Proton Standard radiation using syngeneic mice bearing orthotopic fibrosarcoma tumors on the hind leg. Tumors were established by intramuscularly injecting radiation-induced fibrosarcoma (RIF) cells in C57BL/6J mice. Tumor growth was monitored by tumor volume measurements, using a caliper. Results: Acute effects of radiation on skin began with erythema, edema, pigment changes and depilation and was followed by complete loss of the epidermis, constant fibrinous exudates and edema. Skin reaction of C3H/HeJ mice exposed to proton FLASH radiation blindly received a 60% lower score than the CONV-irradiated mice at day 24 post IR, whereas C57BL/6J mice received 60% lower score at day 39, as they appear to be more radiosensitive. Leg contracture was clearly observed by day 68 in the C3H/HeJ whereas in C57BL/6J appeared much earlier, at 10 days post-radiation. Proton FLASH-irradiated group of C57BL/6J mice presented 50% less leg contracture as compared to the CONV-irradiated group, by day 46. MPO activity peaked for both strains at day 18 post radiation and FLASH-irradiated mice showed significantly higher levels of MPO activity compared to the CONV-irradiated mice. The MPO activity was still significantly different between proton FLASH and CONV groups up to day 27 in C57BL/6J mice. Moreover, proton FLASH and CONV radiation inhibited fibrosarcoma tumor growth to the same extent, and there was no significant difference in tumor growth delay or overall survival between the two groups. Conclusions: Proton FLASH radiation causes significant less skin and soft tissue injury as well as lower levels of inflammation post-radiation compared to proton CONV radiation whereas tumor growth inhibition is indistinguishable between the two modalities. Citation Format: Anastasia Velalopoulou, Ilias V. Karagounis, Ioannis I. Verginadis, Denisa Goia, Michele Kim, Khayrullo Shoniyozov, Keith Cengel, Eric Diffenderfer, Lei Dong, James Metz, Theresa Busch, Amit Maity, Costas Koumenis. Proton FLASH radiation spares normal skin and soft tissues of the murine leg from radiation-induced damage while being equipotent with standard proton radiation in controlling sarcoma growth [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 5349.

Asmens, patyrusio sunkia galvos trauma, ankstyvos stacionarines reabilitacijos veiksmingumo ivertinimas. Klinikinio atvejo analize

Tyrimo tikslas. Ivertinti sunkia galvos smegenu trauma (GST) patyrusio asmens ankstyvos stacionarines reabilitacijos veiksminguma. Tyrimo metodika. Taikytas kokybinis atvejo tyrimo metodas. Tyrimo duomenys buvo surinkti iš paciento ligos istorijos, analizuojamas kompleksines reabilitacijos poveikis. Rezultatai. Tiriamosios savarankiškumo pokyciams didele reikšme turejo ankstyvoji reabilitacija. Jos metu sumažejo kaires ranku ir koju kontrakturos, sustiprejo kaires kojos raumenu jega nuo 0 iki 2 balu, dešines kojos – nuo 3 iki 5 balu, kaires rankos – nuo 0 iki 1 balo, dešines rankos – nuo 3 iki 5 balu. Pagerejo artikuliacine motorika ir ekspresyvioji kalba. Reabilitacijos metu savarankiškumas pagal Barthel indeksa padidejo iki 20 balu. Išvados. Ankstyva sunkia galvos smegenu trauma patyrusio asmens stacionarine kompleksine reabilitacija, intensyviai taikant multisensorines stimuliacijos programa, gali žymiai pagerinti funkcini savarankiškuma. Tai rodo ir šis klinikinis atvejis: padidejo tiriamosios galuniu raumenu jega, pagerejo atmintis, demesys, artikuliacine motorika ir ekspresyvioji kalba, išaugo savarankiškumas.

BPC 157 Therapy Heals Tendon Muscle Junction in Rats

AimAfter tendon was separated from muscle in the right quadriceps muscle in rats, we focused on the tendon‐muscle junction healing and therapy with the stable gastric pentadecapeptide BPC 157. Noteworthy, BPC 157 is an original antiulcer peptide, stable in human gastric juice, used in ulcerative colitis and now multiple sclerosis trials), with particular wound healing ability: healing of transected or crushed muscle, transected or detached tendon, and transected ligament, demonstrated macro/microscopically, biomechanically and functionally (i.e., absent leg contracture), with parenteral and peroral therapy application (Curr Pharm Des. 2017;23(27):4012–4028; J Orthop Res. 2006 May;24(5):1109–17; J Orthop Res. 2006 May;24(5):982–9; J Orthop Res. 2003 Nov;21(6):976–83).MethodsUnder deep rat anesthesia tendon muscle junction of right quadriceps muscle was presented, and without direct transection of tendon muscle junction, the tendon was gently separated from muscle fibres. Medication was BPC 157 (10 ug or 10 ng/kg/day, intraperitoneally or in drinking water (0.16ug or 0.16ng/ml; 12ml/rat/day) while controls received an equivolume of saline (5 ml/kg intraperitoneally) or drinking water only. Macro/microscopical, biomechanical assessment was at 1st, 2nd, 4th, and 6th week after surgery, while functional presentation (walking patterns, leg contracture) was daily assessed.ResultsGross assessment reveals in quadriceps muscle a huge defect between tendon and muscle sustainably progressing throughout the experiment and failed healing. By contrast, in rats underwent tendon muscle junction separation that received BPC 157, the healing was continuously presented. Since very beginning, BPC 157 rats presented defect markedly less and finally grossly reestablished tendon muscle junction (Fig. 1). Also, controls exhibited severe leg contracture, and tottering walk, which were fully counteracted by BPC 157 therapy. These results are completely confirmed by microscopy. Illustratively, at 2nd week controls showed edema of the tendon with moderate lymphocytic infiltrate and formation of granulation tissue, while BPC 157 rats exhibited only minimal lymphocytic infiltrate with no granulation tissue formation in all pentadecapeptide BPC 157 treated animals and with better already reestablished myotendinous junction structures (Fig. 2). Likewise, biomechanic assessment demonstrated only a poor recovery of muscle strength in controls, while a full recovery ensues in BPC 157 treated rats.ConclusionIn addition to the therapy of the injured muscle and tendon, BPC 157 therapy could also specifically benefit the injuries of tendon muscle junction.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

A New Approach for Quantifying Radio-Biological Effects Using the Time Course of Mouse Leg Contracture.

A digitization approach to the time course of radiation-induced mouse leg contracture was proposed for quantifying the radiation effect on an individual living mouse. The shortening of the mouse leg length can be easily measured with a caliper/ruler to offer a very simple digitalized index of the radiation effect. Left hind legs of mice were irradiated with single dose of 32 Gy of 290 MeV carbon-ion beam using 0, 50, or 117 mm binary filter (BF). The right legs were used as a control. The lengths of both hind legs of the mice were measured using a digital caliper before irradiation and every week after irradiation. The degree of leg contracture, ΔSt, at the time point t was estimated by subtraction of the left irradiated leg length from the right control leg length. Equation was fitted on the daily time course of ΔSt, and two parameters, ΔSmax and Ts, were estimated. ΔSt=ΔSmax×(1-exp(t/Ts)), where ΔSmax is the maximum degree of leg contracture, and Ts is time of leg contracture. The effect of carbon-ion irradiation on a living mouse was quantified by ΔSmax and Ts of the leg contracture, and then compared to that of X-rays. By 32 Gy irradiation, ΔSmax was largest for the BF117 experiment, followed by X-ray~BF50>BF0. Ts was shortest for the BF50 experiment, while other irradiation conditions give similar Ts. A logarithmic function was successfully repurposed for the evaluation of radio-biological response.

Síndrome congénito secundario a infección por el virus zika durante el embarazo

Se describe el caso de una recién nacida que al nacimiento presentó llanto constante, microcefalia, pie calcaneus derecho, pie equino varo izquierdo, y contractura en pierna izquierda. La prueba de IgM de la recién nacida fue positiva para virus Zika. Las anormalidades descritas son actualmente conocidas como síndrome congénito secundario a infección por virus Zika durante el embarazo.

Abstract 5212: Metabolic reprogramming of radiation fibrosis using adipose derived stromal cells

Abstract Background: Soft tissue radiation fibrosis (RF) affects up to 70% of cancer survivors post-radiotherapy. RF is an irreversible and progressive side effect of radiotherapy characterized by poor tissue elasticity and increased ECM deposition, clinically translating to increased morbidity due to hardening, distortion, and pain. Recent evidence has highlighted the potential role of metabolic alterations in the onset and progression of fibrosis. Adipose derived stromal cells (ADSCs) have been used effectively for enhancing complex wound repair in a number of clinical trials. The therapeutic effect of ADSCs has been attributed to its secretion of paracrine factors, which can regulate the metabolism of target cells. Even so, the metabolic effects of ADSCs on target cells is not well described. Methods and Results: Transcriptomic profiling and targeted metabolomics of human radiated tissue and a murine model of RF revealed that suppression of fatty acid oxidation (FAO) is hallmark of RF. TGF-B, a master regulator of fibrosis, has a large effect in suppressing FAO in primary human fibroblasts in vitro through downregulating genes in the PPAR pathway, a major regulatory pathway for FAO, and through inhibiting oxidation of the long chain fatty acid, palmitic acid (p&amp;lt;0.05, t-test). Treatment of TGF-B stimulated fibroblasts with ADSC conditioned media resulted in an improvement in FAO and a reduction in fibronectin, collagen-1, and PAI-1 protein levels, three of major contributors to fibrosis. Transplantation of ADSCs into murine RF resulted in a metabolic shift back to FAO and a significant reduction in RF both functionally (percentage leg contracture 36% vs 26%, 2-way ANOVA &amp;lt; 0.05) and histologically through image analysis of trichrome staining (p&amp;lt;0.01, t-test). Pathway analysis of significant genes altered by ADSCs revealed an upregulation of the PPAR pathway was the most significant effect of ADSC transplantation. Untargeted metabolomics confirmed that FAO metabolites were significantly upregulated with ADSC transplantation. To confirm the importance of metabolic regulation by ADSCs, we utilized a pharmacogenomics strategy to uncover a compound that mimicked the effect of ADSCs. Drug A ranked highest and replicated the anti-fibrotic and pro-FAO effects of ADSCs both on TGF-B stimulated primary fibroblasts and in murine RF. Etomoxir, a FAO inhibitor, inhibited the effect of ADSCs and Drug A in regulating protein levels of fibronectin and collagen, revealing that ADSCs and Drug A require an intact FAO pathway to exert their anti-fibrotic effects. Conclusions: Inhibition of FAO is a novel hallmark of RF. ADSC-mediated metabolic reprogramming resulted in an enhancement of FAO and a reduction in RF through upregulating the PPAR pathway. ADSC-directed pharmacogenomics uncovered Drug A, which mimicked the pro-FAO and anti-fibrotic effects of ADSCs. Our research has highlighted the importance of reversing metabolic aberrations to reduce RF. Citation Format: Xiao Zhao, Laleh Soltan Ghoraie, Pamela Psarianos, Kenneth Yip, Laurie Ailles, Benjamin Haibe-Kains, Fei-Fei Liu. Metabolic reprogramming of radiation fibrosis using adipose derived stromal cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5212. doi:10.1158/1538-7445.AM2017-5212

BPC 157: The counteraction of succinylcholine, hyperkalemia, and arrhythmias

After the demonstration of its life-saving effect in severe hyperkalemia and the recovery of skeletal muscle after injury, pentadecapeptide BPC 157 has been shown to attenuate the local paralytic effect induced by succinylcholine, in addition to systemic muscle disability (and consequent muscle damage). Hyperkalemia, arrhythmias and a rise in serum enzyme values, were counteracted in rats. Assessments were made at 3 and 30min and 1, 3, 5, and 7 days after succinylcholine administration (1.0mg/kg into the right anterior tibial muscle). BPC 157 (10µg/kg, 10ng/kg) (given intraperitoneally 30min before or immediately after succinylcholine or per-orally in drinking water through 24h until succinylcholine administration) mitigated both local and systemic disturbances. BPC 157 completely eliminated hyperkalemia and arrhythmias, markedly attenuated or erradicated behavioral agitation, muscle twitches, motionless resting and completely eliminated post-succinylcholine hyperalgesia. BPC 157 immediately eliminated leg contractures and counteracted both edema and the decrease in muscle fibers in the diaphragm and injected/non-injected anterior tibial muscles. Therefore, the depolarizing neuromuscular blocker effects of succinylcholine were successfully antagonized.

Protective effect of α-lipoic acid against radiation-induced fibrosis in mice.

Radiation-induced fibrosis (RIF) is one of the most common late complications of radiation therapy. We found that α-lipoic acid (α-LA) effectively prevents RIF. In RIF a mouse model, leg contracture assay was used to test the in vivo efficacy of α-LA. α-LA suppressed the expression of pro-fibrotic genes after irradiation, both in vivo and in vitro, and inhibited the up-regulation of TGF-β1-mediated p300/CBP activity. Thus, α-LA prevents radiation-induced fibrosis (RIF) by inhibiting the transcriptional activity of NF-κB through inhibition of histone acetyltransferase activity. α-LA is a new therapeutic methods that can be used in the prevention-treatment of RIF.

The Role of Adipose Derived Stromal Cells for Reversal of Radiation Fibrosis

The Role of Adipose Derived Stromal Cells for Reversal of Radiation Fibrosis

Abstract 1804: The role of adipose derived stromal cells for reversal of radiation fibrosis

Abstract Hypothesis: Up to 70% of patients after radiotherapy develop radiation fibrosis (RF), an irreversible scarring of normal tissue resulting in functional morbidity and increased risk of surgical complications. Adipose-derived stromal cells (ADSCs) have been used effectively for the treatment of complex wounds in animal models and clinical trials. We hypothesize that ADSCs may reverse RF by repopulating mesenchymal precursor cells and by providing angiogenic, anti-inflammatory, and matrix remodeling factors. Methods: A RF animal model was developed and ADSC isolation was confirmed by immunophenotype and differentiation assay. GFP and luciferase labelled ADSCs were used to assess biodistribution after transplantation. To determine the therapeutic effect of ADSC transplantation for RF, we assessed functional changes to leg contracture, oxygen saturation and perfusion and molecular changes to inflammation, vascularization, and matrix remodeling. To determine the mechanism of ADSC-mediated fibrosis reversal, we assessed transcriptomic and epigenetic changes to RF tissue. Results: A RF model was created by radiating the hind limb of C3H mice. This model showed a dose dependent leg contracture and histological findings of fibrosis. We confirmed the immunophenotype of isolated ADSC and their ability to differentiate into adipogenic, chondrogenic, and osteogenic lineages. ADSC transplantation showed a statistically significant trend towards improved leg contracture (2-way ANOVA, p&amp;lt;0.05). Biodistribution studies confirmed the presence of ADSCs in the subdermis of RF tissue with persistence for at least 18 days post-transplantation. Preliminary RNA-seq analysis using unsupervised hierarchical clustering showed ADSC treated radiation tissue was more similar to normal tissue than control. In depth RNA-seq data analysis is underway. Conclusions: ADSC transplantation may be an effective treatment for the reversal of radiation fibrosis. As cancer survivorship increases, the prevalence of radiation fibrosis will rise and necessitate increased focus on effective treatment strategies for this condition. Citation Format: Xiao Zhao, Ju Hee Lee, Kenneth Yip, Laurie Ailles, Fei-Fei Liu. The role of adipose derived stromal cells for reversal of radiation fibrosis. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1804. doi:10.1158/1538-7445.AM2015-1804

The epidural electric stimulation test does not predict local anesthetic spread or consumption in labour epidural analgesia

The epidural electrical stimulation test (EEST) is a highly specific and sensitive test for confirming placement of the epidural catheter in the epidural space. The purpose of this study was to investigate if the EEST could predict the spread and consumption of local anesthetic solutions during labour epidural analgesia. This observational study was conducted in labouring parturients requesting epidural analgesia. The EEST was performed after the epidural catheter placement (T0) and repeated five minutes after a test dose with 2% lidocaine 3 mL (T1). The minimum current required to elicit the motor response at each time point was recorded. A loading dose of 0.125% bupivacaine 10 mL and fentanyl 50 μg was administered and followed by patient-controlled epidural analgesia with 0.0625% bupivacaine and fentanyl 2 μg·mL(-1) (baseline infusion 10 mL·hr(-1), bolus dose 5 mL, lockout interval ten minutes, maximum dose 20 mL·hr(-1)). The primary outcome was the correlation between the current required to elicit motor responses at T0 and T1 and the consumption of bupivacaine in the first two hours of epidural administration. The secondary outcomes included the muscle contraction patterns determined by the EEST and the incidence of failed, inadequate, or asymmetric blocks. The study was conducted in 102 parturients. The mean electric current required to elicit muscle response was 4.43 mA (range 1-10 mA) at T0, 5.97 mA (range 1-14 mA) at T1, and the mean Δ (T1-T0) current was 1.54 mA (range 0-8 mA). There was no correlation between either the mean baseline current required or the Δ (T1-T0) current and the total bupivacaine consumption at two hours. The incidence of inadequate blocks at two hours was 18%; however, none of the catheters required replacement. Unilateral left (34%) or right (31%) leg contraction was the most frequent pattern elicited by the EEST. The EEST shows a wide range of electrical current requirements and elicits a variety of muscle twitch patterns on the lower limbs. Although it confirms the epidural placement of the catheter, the EEST cannot be used to predict the spread or consumption of the local anesthetic solution during labour epidural analgesia.

Abstract 2494: The protective effect of a novel transforming growth factor-β receptor inhibitor against radiation-induced fibrosis

Abstract Although radiation-induced fibrosis (RIF) is one of the common sequelae after irradiation of skin and soft tissue, a protective method was not well investigated. The purpose of present study was to assess the protective effect of a newly developed small molecular inhibitor of transforming growth factor (TGF)-β receptor (ALK5 inhibitor) against RIF in mouse model. BALB/c male mice were irradiated 8 weeks after birth. The left hind limbs of mice received two radiation doses of 22 Gy, once in a week. Specially designed shielding for the rest of the body was used, and 1-cm thickness bolus was applied over the skin to ensure adequate radiation dose at the surface of hind leg. After irradiation, 40 mice were randomly divided into two groups of 20 mice each. Each group was treated with once daily intraperitoneal injections of saline (group 1) or ALK5 inhibitor (group 2, 10 mg/kg/day). RIF was assessed by leg contraction test using specially designed Lucite jig under anesthesia every 2 weeks for 6-16 weeks after irradiation. The length of the extended irradiated leg was compared with the contralateral unirradiated leg. Early and late skin reactions were scored by grading system. Early skin reaction was measured every week for first 4 weeks, and late skin reaction was evaluated at 16 weeks after irradiation. The ALK5 inhibitor was well tolerated, and no toxic effects related to the drug were observed. There were no significant differences in the average of body weight (g) between the two groups during treatment; 22.76 vs. 23.34 in 6-week (p=0.09), 25.73 vs. 26.05 in 10-week (p=0.466), and 28.54 vs. 28.41 in 13-week (p=0.868). The acute skin reaction was almost identical between the two groups. All mice showed moist desquamation for most of hind limb in 4 weeks after irradiation, and no significant skin necrosis was observed in both two groups during acute phase. The leg contraction test showed significant protective effect in group 2. The average length of the irradiated leg (percent of the contralateral leg) was significantly lower in group 1 from 6-16 weeks, and the differences of the contracture between the two groups tended to increase with time; 92.46% vs. 96.07% in 6-week (p&amp;lt;0.001), 92.55% vs. 95.89% in 8-week (p&amp;lt;0.001), 88.23% vs. 93.34% in 10-week (p&amp;lt;0.001), 83.25% vs. 91.59% in 12-week (p&amp;lt;0.001), 76.80% vs. 87.61% in 14-week (p&amp;lt;0.001), and 74.42% vs. 83.08% in 16-week (p=0.001). Also, late skin reactions were more adverse in control group; the average score of late skin reaction was 3.14 in group 1 and 2.73 in group 2 (p=0.034). The current study showed that inhibition of TGF-β signaling by our ALK5 inhibitor has a protective effect on RIF in mouse model. Also, there was no significant toxicity related to the drug administration. This newly developed ALK5 inhibitor could be considered as a novel agent for protection of RIF. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2494. doi:10.1158/1538-7445.AM2011-2494

Intraperitoneal administration of chitosan/DsiRNA nanoparticles targeting TNFα prevents radiation-induced fibrosis

Background and purpose One of the most common and dose-limiting long-term adverse effects of radiation therapy is radiation-induced fibrosis (RIF), which is characterized by restricted tissue flexibility, reduced compliance or strictures, pain and in severe cases, ulceration and necrosis. Several strategies have been proposed to ameliorate RIF but presently no effective one is available. Recent studies have reported that tumor necrosis factor-α (TNFα) plays a role in fibrogenesis. Material and methods Male CDF1 mice were radiated with a single dose of 45 Gy. Chitosan/DsiRNA nanoparticles targeting TNFα were intraperitoneal injected and late radiation-induced fibrosis (RIF) was assessed using a modification of the leg contracture model. Additionally, the effect of these nanoparticles on tumor growth and tumor control probability in the absence of radiation was examined in a C3H mammary carcinoma model. Results We show in this work, that targeting TNFα in macrophages by intraperitoneal administration of chitosan/DsiRNA nanoparticles completely prevented radiation-induced fibrosis in CDF1 mice without revealing any cytotoxic side-effects after a long-term administration. Furthermore, such TNFα targeting was selective without any significant influence on tumor growth or irradiation-related tumor control probability. Conclusion This nanoparticle-based RNAi approach represents a novel approach to prevent RIF with potential application to improve clinical radiation therapeutic strategies.