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1.
J Clin Orthop Trauma ; 43: 102229, 2023 Aug.
Article de Anglais | MEDLINE | ID: mdl-37588080

RÉSUMÉ

Background: The key rehabilitation goal for cervical cord injury is promoting functional hand movement. Patients with mid to low-level cervical spinal cord injury can achieve the useful tenodesis grasp with the assistance of upper extremity orthosis. In this study, a custom molded writing device was fabricated and applied on cervical cord injured patients with the aim of hand rehabilitation. Methods: A total of fourteen individuals with cervical spinal cord injury at C6-C7 level were recruited for the study. They were divided into two groups, where the experimental group was prescribed with the custom molded writing device and the standard-of-care group was prescribed with the traditionally available writing device. The performance of the devices was evaluated using the Quest 2.0 questionnaire and the quality of writing after an intervention time of 4 weeks. Result: The group that used custom molded writing device performed comparatively better when compared to the conventional design. The data showed a significant difference with average QUEST scores of 4.47 ± 0.33 for the group using the wrist-driven writing device and 3.04 ± 0.70 for group using the conventional design. For better understanding of the device's performance, the writing with both the splints was also assessed. Conclusion: A writing device using the tenodesis grasp was fabricated to rehabilitate the writing skills of individuals with cervical spinal cord injuries. The performance of the device provided a favorable result indicating to elaborate the study for future references.

2.
J Orthop Case Rep ; 11(7): 41-44, 2021 Jul.
Article de Anglais | MEDLINE | ID: mdl-34790601

RÉSUMÉ

INTRODUCTION: Internal Jugular Venous (IJV) cannulation or central-line insertion is frequently performed during kyphoscoliosis deformity correction surgery or spine surgery with high risk. This helps monitor central venous pressure and administer medicines when required. Although many complications of IJV cannulation have been reported in the literature, its effect on brachial plexus is not known. The objective of this paper was to report a rare complication of IJV during scoliosis surgery. CASE PRESENTATION: We reported a case of 27-year-old male who was operated for severe kyphoscoliosis correction where preoperatively IJV cannulation was done. Repeated attempts were done during IJV cannula insertion due to altered anatomy. Eventually, cannula insertion was done using ultrasound modality and surgery for correction was done. Postoperatively patient developed right upper extremity weakness and sensory loss although the clinical result of kyphoscoliosis correction was acceptable. EMG-NCV study proved it brachial plexus injury. The patient was treated with intravenous steroid and physiotherapy. The patient recovered completely within 6 months of surgery. CONCLUSION: We reported a case of kyphoscoliosis deformity corrective surgery where IJV cannulation led to brachial plexus injury and was eventually recovered with medications and physiotherapy.

4.
Clin Spine Surg ; 34(3): 109-118, 2021 04 01.
Article de Anglais | MEDLINE | ID: mdl-33003049

RÉSUMÉ

STUDY DESIGN: This was a prospective study. OBJECTIVES: To correlate improvement in motor evoked potential (MEP) during spine surgery with postoperative clinical improvement. MATERIALS AND METHODS: Three hundred fifty-three patients operated for posterior spinal decompression and fixation surgeries were prospectively selected and followed up. Patients who underwent lumbar, dorsal, and cervical surgeries were grouped into-group A, B, and C, respectively. Intraoperative neuromonitoring was done using MEP with free-running electromyography. Improvements in MEP scores were calculated in percentage. Similarly, postoperative improvement in Oswestry disability index (ODI) and visual analog scale (VAS) scores at 3 months were calculated in percentage. Improvements in MEP scores were correlated with clinical improvement using the Spearman ρ test and the r value was calculated to find out the association. RESULTS: Of 353 patients, 319 (250-group A, 38-group B, and 31-group C) were included for the study. VAS and ODI improved significantly from preoperative 8.5±0.8 and 62.9±14.5, to postoperative 2.3±1.1 and 15.9±11.5, respectively, in the entire group. Average preoperative MEP were 127.8±191.0 mV on the right side and 132.3±206.6 mV on the left side, which significantly improved to 163.7±231.2 mV (P=0.0001) and 155.2±219.6 mV (P=0.0001), respectively, showing 157.0% and 178.5% improvement. Correlating MEP improvement with postoperative improvement in ODI showed poor correlation (r=0.088 right and 0.030 left sides). Similarly, correlating MEP improvement with improvement in VAS showed r=0.110 on the right and -0.023 on the left side suggesting poor correlation. Postoperative neurological complications (0.56%) were found in 2 patients in the form of screw malpositioning. CONCLUSIONS: Intraoperative neuromonitoring showed significant improvement during posterior decompression and fixation surgery, and reduction in postoperative neurological complication. The study also exhibited significant postoperative clinical improvement. However, improvement in MEP did not correlate with postoperative clinical improvement suggesting that it has no predictive role.


Sujet(s)
Procédures de neurochirurgie , Rachis , Décompression chirurgicale , Humains , Études prospectives
5.
Injury ; 52(6): 1569-1576, 2021 Jun.
Article de Anglais | MEDLINE | ID: mdl-33257016

RÉSUMÉ

INTRODUCTION: Treatment of complex upper end tibial fractures has always been a challenge to orthopaedic surgeons. Though the roentgenogram results are satisfactory, the clinical and functional outcomes especially in terms of squatting/cross-leg sitting after long term follow-up are little known. Hence, we have done this study with a primary aim to assess the clinico-radiological and functional outcomes after operative fixation (mostly by locking plates) in complex upper end tibial fractures and a secondary aim to analyze correlation between functional outcome scores/range of motion (ROM) and the ability to squat & sit cross-legged in post-operative period. MATERIALS AND METHODS: This prospective study included a total of 33 patients who were mainly treated with locking plates. In the follow-up, patients were assessed clinico-radiologically and outcome measurements were determined using the Tegner-Lysholm (T-L) Knee Score. Patients were categorized according to their ability to squat/sit cross-legged and a subgroup analysis was performed by comparing mean ROM and T-L score in each group. RESULTS: Majority of patients were in young and adult age group with a male to female ratio of 4.5:1. The average age was 42.39 ±14.64 years. Road traffic accident was the most common mode of injury. Average time interval between injury and surgery was 5.8±4.4 days. All the fractures united by 5-9 months. Mean ROM and T-L score at last follow-up were 120.94°±13.63° and 88.12±7.24 respectively. Average shortening, varus and valgus deformity were 0.43±0.09 cm, 2.12°±0.62° and 1.06°±0.45° respectively. 14 patients (42.42%) were able to squat and 15 (45.45%) were able to sit cross-legged postoperatively. Upon subgroup analysis, difference of mean ROM in those who could squat/sit cross-legged was found statistically significant (p≤0.05), however the difference in mean functional scores was not significant (p≥0.05). CONCLUSION: Complex upper tibial fractures are a difficult entity to deal with. Anatomical locking plates take care of the alignment, articular congruity as well as ligamentous balancing thus giving good mid-term outcomes after ORIF/MIPO. However, applicability of the present functional outcome scores in assessing squatting/cross leg sitting remains doubtful. More weightage needs to be given to these activities to evaluate the outcome in South Asian population.


Sujet(s)
Fractures du tibia , Adulte , Femelle , Ostéosynthèse interne , Humains , Jambe , Mâle , Adulte d'âge moyen , Études prospectives , Amplitude articulaire , Position assise , Fractures du tibia/imagerie diagnostique , Fractures du tibia/chirurgie , Résultat thérapeutique
6.
J Clin Orthop Trauma ; 11(5): 816-821, 2020.
Article de Anglais | MEDLINE | ID: mdl-32904094

RÉSUMÉ

INTRODUCTION: Back pain is a common ailment affecting individuals around the globe. Animal models to understand the back pain mechanism, treatment modalities, and spinal cord injury are widely researched topics worldwide. Despite the presence of several animal models on disc degeneration and Spinal Cord Injury, there is a lack of a comprehensive review. MATERIAL AND METHOD: A methodological narrative literature review was carried out for the study. A total of 1273 publications were found, out of which 763 were related to spine surgery in animals. The literature with full-text availability was selected for the review. Scale for the Assessment of Narrative Review Articles (SANRA) guidelines was used to assess the studies. Only English language publications were included which were listed on PubMed. A total of 113 studies were shortlisted (1976-2019) after internal validation scoring. RESULT: The animal models for spine surgery ranged from rodents to primates. These are used to study the mechanisms of back pain as well as spinal cord injuries. The models could either be created surgically or through various means like use of electric cautery, chemicals or trauma. Genetic spine models have also been documented in which the injuries are created by genetic alterations and knock outs. Though the dorsal approach is the most common, the literature also mentions the anterior and lateral approach for spine surgery animal experiments. CONCLUSION: There are no single perfect animal models to represent and study human models. The selection is based on the application and the methodology. Careful selection is needed to give optimum and appropriate results.

7.
Sci Rep ; 10(1): 12017, 2020 07 21.
Article de Anglais | MEDLINE | ID: mdl-32694557

RÉSUMÉ

Low back pain is often the direct result of degeneration of the intervertebral disc. A wide range of therapeutics including anti-catabolic, pro-anabolic factors and chemo-attractants that can stimulate resident cells and recruit endogenous progenitors are under consideration. The avascular nature and the dense matrix of this tissue make it challenging for systemically administered drugs to reach their target cells inside the nucleus pulposus (NP), the central gelatinous region of the intervertebral disc (IVD). Therefore, local intra-discal injection of therapeutic drugs directly into the NP is a clinically relevant delivery approach, however, suffers from rapid and wide diffusion outside the injection site resulting in short lived benefits while causing systemic toxicity. NP has a high negative fixed charge density due to the presence of negatively charged aggrecan glycosaminoglycans that provide swelling pressures, compressive stiffness and hydration to the tissue. This negative fixed charge density can also be used for enhancing intra-NP residence time of therapeutic drugs. Here we design positively charged Avidin grafted branched Dextran nanostructures that utilize long-range binding effects of electrostatic interactions to bind with the intra-NP negatively charged groups. The binding is strong enough to enable a month-long retention of cationic nanostructures within the NP following intra-discal administration, yet weak and reversible to allow movement to reach cells dispersed throughout the tissue. The branched carrier has multiple sites for drug conjugation and can reduce the need for multiple injections of high drug doses and minimize associated side-effects, paving the way for effective clinical translation of potential therapeutics for treatment of low back pain and disc degeneration.


Sujet(s)
Avidine/administration et posologie , Dextrane/administration et posologie , Systèmes de délivrance de médicaments/méthodes , Disque intervertébral/effets des médicaments et des substances chimiques , Nanostructures/administration et posologie , Animaux , Avidine/pharmacologie , Bovins , Dextrane/pharmacologie , Glycosaminoglycanes , Période , Injections , Dégénérescence de disque intervertébral/traitement médicamenteux , Lombalgie/traitement médicamenteux , Nucleus pulposus/effets des médicaments et des substances chimiques , Nucleus pulposus/métabolisme , Électricité statique
8.
J Orthop Case Rep ; 10(4): 38-41, 2020 Jul.
Article de Anglais | MEDLINE | ID: mdl-33623764

RÉSUMÉ

INTRODUCTION: Hip joint fracture-dislocations are rare injuries and usually result from high energy trauma. Femoral head fractures account for only 7-16% of all hip fracture-dislocations. There is always a controversy regarding optimal surgical treatment modality and approach for the treatment of Pipkin type IV fractures. In a 60 years old individual, various reports favor primary hip arthroplasty as compared to open reduction and internal fixation (ORIF). The posterior approach is preferred because it provides adequate exposure of the acetabular fracture and an opportunity for simultaneous repair of the femoral head and acetabular fractures. Another benefit is that anterior vascular supply to the femoral head and abductor function can be preserved. CASE REPORT: In this case report, we present a neglected 15 days old rare injury (Pipkin type IV femoral head fracture) in a 60 years old male patient that was given a trial of hip preservation surgery by ORIF through posterior (Kocher-Langenbeck) approach. CONCLUSION: A neglected case of Pipkin type IV injury with chances of avascular necrosis and arthritis can be given a trial of hip preservation surgery because in an Indian scenario sitting cross legged and squatting are indispensable activities of daily lifestyle and appropriate surgical technique, adequate exposure, anatomic reduction, and stable internal fixation of the fractures are critical to achieve satisfactory clinical results.

9.
Asian Spine J ; 13(1): 1-6, 2019 Feb.
Article de Anglais | MEDLINE | ID: mdl-30326697

RÉSUMÉ

STUDY DESIGN: Retrospective study. PURPOSE: Missing cottonoids during and after spinal surgery is a persistent problem and account for the most commonly retained surgical instruments (RSIs) noticed during a final cottonoid count. The aim of this study was to enumerate risk factors and describe the sequence to look out for misplaced cottonoids during spinal surgery and provide an algorithm for resolving the problem. OVERVIEW OF LITERATURE: There are only a few case reports on RSIs among various surgical branches. The data is inconclusive and there is little evidence in the literature that relates to spinal surgery. METHODS: This retrospective study was conducted at Indian Spinal Injuries Centre. The data was collected from hospital records ranging from January 2013 to December 2017. The surgical cases in which cottonoid counts were inconsistent during or after the procedure were included in the study. The case files along with operating theater records were thoroughly screened for selecting those in which there was confirmed evidence of such an event. RESULTS: There were 7,059 spinal surgeries performed during the study period. Fifteen cases of miscounts were recorded with an incidence of one in every 471 cases. Cottonoids were most commonly lost under the shoes of the surgeon or assistants. In two instances, cottonoids were found in the surgical field and trapped in the interbody cage site. Based on these locations, a systematic search algorithm was created. CONCLUSIONS: This study enumerates RSI risk factors in spinal surgical procedures and describes steps that can be followed to account for any missing cottonoids. The incidence of missing cottonoids can be decreased using a goal-oriented approach and ensuring that surgical teams work in collaboration.

10.
Indian J Orthop ; 52(6): 578-583, 2018.
Article de Anglais | MEDLINE | ID: mdl-30532296

RÉSUMÉ

In the current clinical scenario, restenosis following the primary surgical procedure for lumbar canal stenosis is being frequently noticed. A number of studies have evaluated the reoperation rates following different surgical procedures for lumbar canal stenosis. However, a dilemma still exists about the surgical procedures, associated comorbidities and reoperation rates. In this study, we have reviewed the existing literature for lumbar canal stenosis surgery and their reoperation rates. A PubMed search for all papers stating "reoperation after spinal stenosis," "revision surgery after spinal stenosis," and "reoperations and lumbar canal stenosis" were explored. A total of 440 publications were found, of which 23 publications were shortlisted. The existing literature on reoperation rates after surgery for lumbar canal stenosis was reviewed and analyzed. From the literature search, 29680 patients who underwent surgeries for spinal stenosis have been included in the review. 11.65% ± 4.25% of them underwent reoperations following the primary procedure with a followup period of 6.80 ± 3.90 years. Fenestration surgeries showed an average reoperation rate of 7.58% ± 5.29% in 8.28 ± 6.26 years followup as compared to laminectomy alone (12.70% ± 7.49%, 6.50 ± 2.12 years followup). Laminectomy with or without fusion showed a reoperation rate of 11.22% ± 4.25% in 6.00 ± 2.60 years followup period. The comparative results of these studies were however not significant. The causes of reoperation were multifactorial ranging from the type of procedure performed, associated comorbidities or smoking. Statistical data do not indicate the superiority of any particular type of surgery, which reduces the rate of reoperation. The causes for reoperation are inadequate decompression or instability. The literature does not give statistics for these complications in the papers. Smoking is an independent risk factor for revision surgery. Diabetes reduces the time interval between the initial surgery and the revision surgery. This review highlights the causes of reoperations in various lumbar stenosis surgeries, associated comorbidities and expected outcome.

11.
Sci Rep ; 7: 41916, 2017 02 06.
Article de Anglais | MEDLINE | ID: mdl-28165488

RÉSUMÉ

To date, there is no periadventitial drug delivery method available in the clinic to prevent restenotic failure of open vascular reconstructions. Resveratrol is a promising anti-restenotic natural drug but subject to low bioavailability when systemically administered. In order to reconcile these two prominent issues, we tested effects of periadventitial delivery of resveratrol on all three major pro-restenotic pathologies including intimal hyperplasia (IH), endothelium impairment, and vessel shrinkage. In a rat carotid injury model, periadventitial delivery of resveratrol either via Pluronic gel (2-week), or polymer sheath (3-month), effectively reduced IH without causing endothelium impairment and vessel shrinkage. In an in vitro model, primary smooth muscle cells (SMCs) were stimulated with elevated transforming growth factor (TGFß) and its signaling protein Smad3, known contributors to IH. TGFß/Smad3 up-regulated Kruppel-like factor (KLF5) protein, and SMC de-differentiation which was reversed by KLF5 siRNA. Furthermore, TGFß/Smad3-stimulated KLF5 production and SMC de-differentiation were blocked by resveratrol via its inhibition of the Akt-mTOR pathway. Concordantly, resveratrol attenuated Akt phosphorylation in injured arteries. Taken together, periadventitial delivery of resveratrol produces durable inhibition of all three pro-restenotic pathologies - a rare feat among existing anti-restenotic methods. Our study suggests a potential anti-restenotic modality of resveratrol application suitable for open surgery.


Sujet(s)
Différenciation cellulaire/effets des médicaments et des substances chimiques , Resténose coronaire/prévention et contrôle , Régulation de l'expression des gènes/effets des médicaments et des substances chimiques , Muscles lisses vasculaires/cytologie , Protéine Smad-3/métabolisme , Stilbènes/pharmacologie , Facteur de croissance transformant bêta/métabolisme , Animaux , Antioxydants/pharmacologie , Prolifération cellulaire/effets des médicaments et des substances chimiques , Cellules cultivées , Resténose coronaire/métabolisme , Resténose coronaire/anatomopathologie , Mâle , Muscles lisses vasculaires/effets des médicaments et des substances chimiques , Muscles lisses vasculaires/métabolisme , Phosphorylation/effets des médicaments et des substances chimiques , Rats , Rat Sprague-Dawley , Resvératrol , Transduction du signal/effets des médicaments et des substances chimiques
12.
Case Rep Orthop ; 2016: 8705204, 2016.
Article de Anglais | MEDLINE | ID: mdl-28078154

RÉSUMÉ

Pheohyphomycosis is an uncommon infection and its association in spondylodiscitis has not yet been reported. The purpose of this case report is to describe a rare case of Pheohyphomycotic spondylodiscitis and methods to diagnose and manage the patient with less invasive techniques. A 29-year-old male patient presented to the outpatient department with complaints of gradually increasing low back pain with bilateral lower limbs radicular pain since one and a half years. He had associated fever, weight loss, voice changes, and dry, scaly, erythematous skin with elevated ESR. The patient had been taking anti-Koch's therapy since 1 year with little relief in pain and no radiological improvement. Percutaneous pedicle biopsy of L4 vertebra was taken under local anaesthesia and confirmed Pheohyphomycosis which was treated with antifungal medications. The patient showed sequential improvement with long term antifungal treatment. He was eventually able to walk independently without support.

13.
Circ Cardiovasc Interv ; 7(4): 594-601, 2014 Aug.
Article de Anglais | MEDLINE | ID: mdl-25074254

RÉSUMÉ

BACKGROUND: Three major processes, constrictive vessel remodeling, intimal hyperplasia (IH), and retarded re-endothelialization, contribute to restenosis after vascular reconstructions. Clinically used drugs inhibit IH but delay re-endothelialization and also cause constrictive remodeling. Here we have examined halofuginone, an herbal derivative, for its beneficial effects on vessel remodeling and differential inhibition of IH versus re-endothelialization. METHODS AND RESULTS: Two weeks after perivascular application to balloon-injured rat common carotid arteries, halofuginone versus vehicle (n=6 animals) enlarged luminal area 2.14-fold by increasing vessel size (adaptive remodeling; 123%), reducing IH (74.3%) without inhibiting re-endothelialization. Consistent with its positive effect on vessel expansion, halofuginone reduced collagen type 1 (but not type 3) production in injured arteries as well as that from adventitial fibroblasts in vitro. In support of its differential effects on IH versus re-endothelialization, halofuginone produced greater inhibition of vascular smooth muscle cell versus endothelial cell proliferation at concentrations ≈50 nmol/L. Furthermore, halofuginone at 50 nmol/L effectively blocked Smad3 phosphorylation in smooth muscle cells, which is known to promote smooth muscle cell proliferation, migration, and IH, but halofuginone had no effect on phospho-Smad3 in endothelial cells. CONCLUSIONS: Periadventitial delivery of halofuginone dramatically increased lumen patency via adaptive remodeling and selective inhibition of IH without affecting endothelium recovery. Halofuginone is the first reported small molecule that has favorable effects on all 3 major processes involved in restenosis.


Sujet(s)
Inhibiteurs de l'angiogenèse/administration et posologie , Angioplastie par ballonnet , Artères carotides/effets des médicaments et des substances chimiques , Lésions traumatiques de l'artère carotide/traitement médicamenteux , Endothélium vasculaire/effets des médicaments et des substances chimiques , Fibroblastes/effets des médicaments et des substances chimiques , Hyperplasie/prévention et contrôle , Myocytes du muscle lisse/effets des médicaments et des substances chimiques , Pipéridines/administration et posologie , Complications postopératoires/prévention et contrôle , Quinazolinones/administration et posologie , Adaptation biologique/effets des médicaments et des substances chimiques , Inhibiteurs de l'angiogenèse/effets indésirables , Animaux , Artères carotides/anatomopathologie , Artères carotides/chirurgie , Lésions traumatiques de l'artère carotide/chirurgie , Prolifération cellulaire/effets des médicaments et des substances chimiques , Cellules cultivées , Collagène de type I/métabolisme , Endothélium vasculaire/anatomopathologie , Fibroblastes/anatomopathologie , Humains , Hyperplasie/étiologie , Mâle , Modèles animaux , Myocytes du muscle lisse/anatomopathologie , Spécificité d'organe , Pipéridines/effets indésirables , Quinazolinones/effets indésirables , Rats , Rat Sprague-Dawley , Protéine Smad-3/métabolisme , Remodelage vasculaire/effets des médicaments et des substances chimiques
14.
J Control Release ; 191: 47-53, 2014 Oct 10.
Article de Anglais | MEDLINE | ID: mdl-24852098

RÉSUMÉ

Intimal hyperplasia produces restenosis (re-narrowing) of the vessel lumen following vascular intervention. Drugs that inhibit intimal hyperplasia have been developed, however there is currently no clinical method of perivascular drug-delivery to prevent restenosis following open surgical procedures. Here we report a poly(ε-caprolactone) (PCL) sheath that is highly effective in preventing intimal hyperplasia through perivascular delivery of rapamycin. We first screened a series of bioresorbable polymers, i.e., poly(lactide-co-glycolide) (PLGA), poly(lactic acid) (PLLA), PCL, and their blends, to identify desired release kinetics and sheath physical properties. Both PLGA and PLLA sheaths produced minimal (<30%) rapamycin release within 50days in PBS buffer. In contrast, PCL sheaths exhibited more rapid and near-linear release kinetics, as well as durable integrity (>90days) as evidenced in both scanning electron microscopy and subcutaneous embedding experiments. Moreover, a PCL sheath deployed around balloon-injured rat carotid arteries was associated with a minimum rate of thrombosis compared to PLGA and PLLA. Morphometric analysis and immunohistochemistry revealed that rapamycin-loaded perivascular PCL sheaths produced pronounced (85%) inhibition of intimal hyperplasia (0.15±0.05 vs 1.01±0.16), without impairment of the luminal endothelium, the vessel's anti-thrombotic layer. Our data collectively show that a rapamycin-loaded PCL delivery system produces substantial mitigation of neointima, likely due to its favorable physical properties leading to a stable yet flexible perivascular sheath and steady and prolonged release kinetics. Thus, a PCL sheath may provide useful scaffolding for devising effective perivascular drug delivery particularly suited for preventing restenosis following open vascular surgery.


Sujet(s)
Agents cardiovasculaires/administration et posologie , Lésions traumatiques de l'artère carotide/traitement médicamenteux , Sténose carotidienne/prévention et contrôle , Vecteurs de médicaments , Néointima , Polyesters/composition chimique , Sirolimus/administration et posologie , Animaux , Agents cardiovasculaires/composition chimique , Lésions traumatiques de l'artère carotide/anatomopathologie , Sténose carotidienne/anatomopathologie , Prolifération cellulaire/effets des médicaments et des substances chimiques , Chimie pharmaceutique , Préparations à action retardée , Modèles animaux de maladie humaine , Hyperplasie , Cinétique , Modèles linéaires , Mâle , Rats , Rat Sprague-Dawley , Sirolimus/composition chimique , Solubilité , Technologie pharmaceutique/méthodes
15.
PLoS One ; 9(2): e89349, 2014.
Article de Anglais | MEDLINE | ID: mdl-24586708

RÉSUMÉ

Intimal hyperplasia is the cause of the recurrent occlusive vascular disease (restenosis). Drugs currently used to treat restenosis effectively inhibit smooth muscle cell (SMC) proliferation, but also inhibit the growth of the protective luminal endothelial cell (EC) lining, leading to thrombosis. To identify compounds that selectively inhibit SMC versus EC proliferation, we have developed a high-throughput screening (HTS) format using human cells and have employed this to screen a multiple compound collection (NIH Clinical Collection). We developed an automated, accurate proliferation assay in 96-well plates using human aortic SMCs and ECs. Using this HTS format we screened a 447-drug NIH Clinical Library. We identified 11 compounds that inhibited SMC proliferation greater than 50%, among which idarubicin exhibited a unique feature of preferentially inhibiting SMC versus EC proliferation. Concentration-response analysis revealed this differential effect most evident over an ∼10 nM-5 µM window. In vivo testing of idarubicin in a rat carotid injury model at 14 days revealed an 80% reduction of intimal hyperplasia and a 45% increase of lumen size with no significant effect on re-endothelialization. Taken together, we have established a HTS assay of human vascular cell proliferation, and identified idarubicin as a selective inhibitor of SMC versus EC proliferation both in vitro and in vivo. Screening of larger and more diverse compound libraries may lead to the discovery of next-generation therapeutics that can inhibit intima hyperplasia without impairing re-endothelialization.


Sujet(s)
Prolifération cellulaire/effets des médicaments et des substances chimiques , Idarubicine/pharmacologie , Muscles lisses vasculaires/effets des médicaments et des substances chimiques , Tunique intime/effets des médicaments et des substances chimiques , Animaux , Cellules cultivées , Cellules endothéliales/effets des médicaments et des substances chimiques , Tests de criblage à haut débit/méthodes , Humains , Hyperplasie/traitement médicamenteux , Mâle , Myocytes du muscle lisse/effets des médicaments et des substances chimiques , Rats , Rat Sprague-Dawley
16.
Cell Signal ; 25(4): 955-60, 2013 Apr.
Article de Anglais | MEDLINE | ID: mdl-23280188

RÉSUMÉ

Restenosis, or arterial lumen re-narrowing, occurs in 30-50% of the patients undergoing angioplasty. Adaptive remodeling is the compensatory enlargement of the vessel size, and has been reported to prevent the deleterious effects of restenosis. Our previous studies have shown that elevated transforming growth factor (TGF-ß) and its signaling protein Smad3 in the media layer induce adaptive remodeling of angioplastied rat carotid artery accompanying an increase of total collagen in the adventitia. In order to gain insights into a possible role of collagen in Smad3-induced adaptive remodeling, here we have investigated a mechanism of cell-cell communication between medial smooth muscle cells (SMCs) and adventitial fibroblasts in regulating the secretion of two major collagen subtypes. We have identified a preferential collagen-3 versus collagen-1 secretion by adventitial fibroblasts following stimulation by the conditioned medium from the TGF-ß1-treated/Smad3-expressing medial smooth muscle cells (SMCs), which contained higher levels of CTGF and IGF2 as compared to control medium. Treating the TGF-ß/Smad3-stimulated SMCs with an siRNA to either CTGF or IGF2 reversed the effect of conditioned media on preferential collagen-3 secretion from fibroblasts. Moreover, recombinant CTGF and IGF2 together stimulated adventitial fibroblasts to preferentially secrete collagen-3 versus collagen-1. This is the first study to identify a preferential secretion of collagen-3 versus collagen-1 from adventitial fibroblasts as a result of TGF-ß/Smad3 stimulation of medial SMCs, and that CTGF and IGF2 function together to mediate this signaling communication between the two cell types.


Sujet(s)
Collagène de type III/métabolisme , Collagène de type I/métabolisme , Fibroblastes/métabolisme , Protéine Smad-3/métabolisme , Facteur de croissance transformant bêta-1/pharmacologie , Animaux , Artères carotides/métabolisme , Cellules cultivées , Facteur de croissance du tissu conjonctif/antagonistes et inhibiteurs , Facteur de croissance du tissu conjonctif/génétique , Facteur de croissance du tissu conjonctif/métabolisme , Fibroblastes/effets des médicaments et des substances chimiques , Protéines à fluorescence verte/génétique , Protéines à fluorescence verte/métabolisme , Facteur de croissance IGF-II/antagonistes et inhibiteurs , Facteur de croissance IGF-II/génétique , Facteur de croissance IGF-II/métabolisme , Myocytes du muscle lisse/effets des médicaments et des substances chimiques , Myocytes du muscle lisse/métabolisme , Interférence par ARN , Petit ARN interférent/métabolisme , Rats , Protéines de fusion recombinantes/génétique , Protéines de fusion recombinantes/métabolisme , Protéine Smad-3/génétique
17.
Cardiovasc Res ; 96(3): 363-71, 2012 Dec 01.
Article de Anglais | MEDLINE | ID: mdl-22918976

RÉSUMÉ

It has been appreciated over the past two decades that arterial remodelling, in addition to intimal hyperplasia, contributes significantly to the degree of restenosis that develops following revascularization procedures. Remodelling appears to be an adventitia-based process that is contributed to by multiple factors including cytokines and growth factors that regulate extracellular matrix or phenotypic transformation of vascular cells including myofibroblasts. In this review, we summarize the currently available information from animal models as well as clinical investigations regarding arterial remodelling. The factors that contribute to this process are presented with an emphasis on potential therapeutic methods to enhance favourable remodelling and prevent restenosis.


Sujet(s)
Angioplastie/effets indésirables , Artères/anatomopathologie , Maladie des artères coronaires/thérapie , Resténose coronaire/étiologie , Intervention coronarienne percutanée/effets indésirables , Maladie artérielle périphérique/thérapie , Animaux , Artères/métabolisme , Resténose coronaire/métabolisme , Resténose coronaire/anatomopathologie , Resténose coronaire/prévention et contrôle , Vaisseaux coronaires/métabolisme , Vaisseaux coronaires/anatomopathologie , Protéines de la matrice extracellulaire/métabolisme , Humains , Néointima , Phénotype , Récidive , Transduction du signal , Résultat thérapeutique
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