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1.
J Intensive Care Med ; : 8850666241245703, 2024 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-38613376

RESUMO

Aconite poisoning refers to toxicity resulting from plants belonging to the Aconitum genus, which comprises over 350 different species of perennial flowering plants that grow in temperate mountainous areas of the northern hemisphere (North America, Europe, Asia). These plants contain a group of toxins known as aconite alkaloids, which encompass numerous closely related toxic compounds. Conventional teaching from toxicology textbooks has broadly classified these alkaloids based on their mechanism of action, often simplifying them as substances that prevent sodium channel inactivation. However, this is an oversimplified and sometimes inaccurate description, as some aconite alkaloids can act as sodium channel blockers. Aconite alkaloids have a long history of use as poisonous substances and have been historically employed for hunting, assassinations, traditional medicine, and self-inflicted harm. Toxicity can occur due to the consumption of traditional medicines derived from aconitum plants or the ingestion of aconite plants and their derivatives. The clinical manifestations of aconite poisoning may encompass gastrointestinal symptoms, sensory alterations, seizures, and life-threatening dysrhythmias that may not respond to standard treatments. Treatment is primarily supportive however evaluation and management of these patients should be personalized and carried out in collaboration with a toxicologist.

2.
AEM Educ Train ; 7(1): e10840, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36711255

RESUMO

Background: The American Board of Emergency Medicine (ABEM) In Training Exam (ITE) gauges residents' medical knowledge and has been shown to correlate with subsequent performance on the ABEM board qualifying examination. It is common for emergency medicine (EM) residencies to employ subspecialty-trained faculty members with the expectation of improved resident education and subspecialty knowledge. We hypothesized that the presence of subspecialty faculty in toxicology would increase residents' scores on the toxicology portion of the ITE. Methods: We assessed ABEM ITE scores at our institution from 2013-2022 and compared these to national data. The exposure of interest was the absence or presence of fellowship-trained toxicology faculty. The primary outcome was performance on the toxicology portion of the ITE, and secondary outcome was overall performance on the exam. Results: Residents who had ≥1 toxicology faculty were 37% (95% CI: 1.01-1.87) more likely to surpass the national average for toxicology scores, and those who had ≥2 toxicology faculty were 77% (95% CI: 1.28-2.44) more likely to surpass the national average for toxicology scores on the ABEM ITE. With the presence of ≥2 toxicology faculty, there was also an increase in toxicology score by years in training, with residents being 63% (95% CI: 1.01-2.64), 68% (95% CI: 1.08-2.61), and 92% (95% CI: 1.01-3.63) more likely to surpass the national average for toxicology score in first, second, and third years of residency, respectively. There was no significant relationship between the presence of toxicology faculty and the overall ABEM ITE scores. Conclusions: The presence of fellowship-trained toxicology faculty positively impacted residents' performance on the toxicology portion of the ABEM ITE but did not significantly impact the overall score. With the presence of ≥2 toxicology faculty we noted an improvement in toxicology scores throughout the 3 years of training, indicating that an individual rotation or educational block is probably less important than spaced repetition through a longitudinal curriculum.

3.
Am J Emerg Med ; 63: 50-54, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36327749

RESUMO

BACKGROUND: There has been an increasing incidence of self-harm attempts in recent years in the United States. Particularly concerning, there has been a growing trend of self-harm in the adolescent and young adult population. In order to inform initiatives to address this trend, risk factors and substances used for self-harm need to be clarified. METHODS: This is a descriptive retrospective observational study on all cases of self-harm poisoning in patients between the ages of 12 and 25 years reported at the state's only tertiary care center from January 2019 through March 2022. RESULTS: There was an increased incidence of 69% for self-harm poisonings for all ages and a 90% increase in ages 12-17 years between the years 2019 and 2021. Fifty percent of all cases occurred in patients aged 14-17 years, 69% were female, and 22% required an intensive care unit. The top three most common substances used are available without a prescription. DISCUSSION: There was a persistent increase in self-harm attempts via poisoning throughout the study period with a particularly vulnerable period in the adolescent age group.


Assuntos
Comportamento Autodestrutivo , Humanos , Feminino , Adolescente , Criança , Adulto Jovem , Adulto , Masculino , Centros de Atenção Terciária , Comportamento Autodestrutivo/epidemiologia
4.
AEM Educ Train ; 6(5): e10804, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36189454

RESUMO

Background: Advancements in research and legislation have improved emergency provider ability to treat opioid use disorder (OUD), but dissemination into rural emergency departments (EDs) is limited. Project Extension for Community Healthcare Outcomes (ECHO) allows community generalists to learn from specialists through telementoring. We aimed to use ECHO to facilitate knowledge translation, increase confidence, and change behavior of rural ED providers treating patients with OUD. Methods: Stakeholder interviews were conducted with rural ED providers. A group of ED addiction experts created an ECHO curriculum with eight OUD topics. ED health professionals were recruited and completed pre/post surveys centered around knowledge and comfort with treating OUD in the ED, with focus on clinical practice and stigma. Following the ECHO model, sessions included a 20-min didactic followed by two cases presented by participants, with discussion facilitated by faculty. Results: Twenty-seven participants registered; seven attended ≥75% of sessions and completed both surveys. Of the seven, three were physicians, two advanced practice providers, one nurse, and one clinical pharmacist. Eight 1-hour sessions were conducted in two cohorts between January and December 2021. On a 5-point Likert scale, respondents on average agreed with questions evaluating acceptability (mean ± SD 3.96 ± 0.64), appropriateness (mean ± SD 4.18 ± 1.18), and feasibility (mean ± SD 4.00 ± 1.17). Participants had a 1.09-point increase (paired t-test = 2.43, p = 0.05) on 7-point Likert-scale questions measuring self-efficacy and a 0.13-point change (paired t-test = 2.64, p = 0.04) on 4-point Likert scale questions measuring stigmatizing attitudes (reduction of attitudes). A total of 71% (5/7) reported changes in clinical practice and 57% (4/7) in departmental protocols after participation. Conclusions: Our ED OUD ECHO course successfully created a model for rural ED providers to learn from ED addiction experts. It was well received and impacted self-reported provider stigmatizing attitudes, patient-facing behavior, and departmental initiatives. Recruitment was challenging and participation was limited. Future efforts will target maximizing recruitment.

6.
Am J Emerg Med ; 56: 394.e1-394.e4, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35287973

RESUMO

BACKGROUND: Flecainide is a 1C antidysrhythmic that is primarily used for ventricular tachycardia or premature ventricular contractions when other treatment is ineffective. It has a very narrow therapeutic window which may cause death in a double dose and requires inpatient initiation for cardiac monitoring. Despite established pharmacokinetic data from flecainide in therapeutic dosing, there is negligible data on flecainide toxicokinetics after an intentional overdose. Due to the inherent differences in pharmacokinetic and toxicokinetic principles, rarely can the peak effect or elimination half-life accurately be applied to the poisoned patient after an overdose. In overdose, flecainide can cause a variety of fatal dysrhythmias which may require sodium bicarbonate for stabilization but also may reduce the renal elimination of flecainide, meaning the life-saving treatment may prolong the time of toxicity. CASE REPORT: We present a case of an acute ingestion of flecainide with a known time of ingestion and known amount of ingestion who experienced subsequent life-threatening effects which required endotracheal intubation, sodium bicarbonate, aggressive electrolyte repletion, and multiple days in an intensive care unit. RESULTS: Serial serum and urine samples revealed a prolonged toxic serum concentration of flecainide. CONCLUSION: These results demonstrate the change in elimination kinetics of flecainide in the setting of urinary alkalization which is evident through prolonged morphologic changes present on serial electrocardiograms.


Assuntos
Overdose de Drogas , Flecainida , Antiarrítmicos/uso terapêutico , Arritmias Cardíacas , Overdose de Drogas/tratamento farmacológico , Eletrocardiografia , Flecainida/uso terapêutico , Humanos , Bicarbonato de Sódio/uso terapêutico
7.
Am J Forensic Med Pathol ; 43(3): 253-255, 2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-35353721

RESUMO

ABSTRACT: Although there are multiple therapeutic uses for colchicine, it is particularly dangerous in the setting of overdose due to an irreversible mechanism of action combined with a narrow therapeutic window. Colchicine is an antimitotic agent that binds tubulin and inhibits microtubule polymerization. This produces a predictable sequence of toxicity beginning with gastrointestinal effects with progression to multiorgan system dysfunction. Unfortunately, there are no specific antidotes for colchicine toxicity after organ injury has occurred, which can lead to tragic consequences. Despite the recognized toxicity, it is exceedingly rare to find a case in the medical literature with a confirmed time of ingestion, amount ingested, data from longitudinal examinations, and laboratory assessments, with a quantitative blood colchicine concentration. We present a case of acute colchicine overdose of 18 mg (approximately 0.25 mg/kg) with subsequent multiorgan failure and death with an antemortem blood colchicine concentration of 14 ng/mL at 18.5 hours after ingestion.


Assuntos
Colchicina , Overdose de Drogas , Ingestão de Alimentos , Humanos , Insuficiência de Múltiplos Órgãos/induzido quimicamente
8.
Am J Emerg Med ; 54: 269-273, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35219014

RESUMO

INTRODUCTION: Bupropion is an antidepressant with unique mechanisms of action leading to a narrow therapeutic window. Parallel to increasing indications, there is an increasing number of overdoses and fatalities attributable to bupropion overdose. Due to the serious effects of a bupropion overdose including arrhythmias and early or delayed seizures, these patients necessitate prolonged monitoring with high levels of medical care. In the setting of a tertiary care center with a medical toxicology consult service, our institution is heavily relied upon to manage these patients. This study was performed to provide clarity on the resources used, lengths-of-stay, and treatments provided for these patients. METHODS: All patients at a tertiary care center with an oral bupropion overdose and a medical toxicology consult less than 24 h after the ingestion were included between July 15, 2017 and October 14, 2021. Chart review was performed to determine lengths-of-stay, the unit of disposition, treatments provided, and outcomes. RESULTS: A total of 73 cases were identified with 36 bupropion-only ingestions. Most cases were transferred from outside facilities, developed seizures, had QRS prolongation; and almost a third required intubation. The vast majority were admitted to an ICU and received GABA-A agonists. A median of 1.47 days per case was spent in the ED or ICU. There was an average of 41.9 ED or ICU bed-days per year and 68.5 non-psychiatric bed-days per year occupied by a patient after a bupropion overdose at a single center. CONCLUSIONS: Bupropion overdose necessitates high resource utilization which we believe will increase with the expanding indications for its use.


Assuntos
Antidepressivos de Segunda Geração , Overdose de Drogas , Bupropiona , Overdose de Drogas/terapia , Humanos , Convulsões/induzido quimicamente , Convulsões/terapia , Centros de Atenção Terciária
9.
Am J Emerg Med ; 55: 226.e1-226.e2, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-34974952

RESUMO

Acute carbon monoxide (CO) poisoning due to smoking hookah has been reported and may present similarly to other causes of acute carbon monoxide poisoning with nausea, headache, and loss of consciousness [1]. In the acute poisoned patient, immediate removal from the carbon monoxide source is paramount in addition to administration of oxygen and possible hyperbaric oxygen therapy (HBO) in certain situations. However, cases of chronic CO poisoning, treatment options, and long-term adverse health effects are far less reported but may include atherosclerosis and vague neurologic symptoms [2]. We present a case of a patient who chronically smoked hookah creating a condition of chronic carboxyhemoglobinemia which was discovered during work up for unexplained polycythemia. While being seen in the hematology clinic, he was found to have a blood carboxyhemoglobin of level 33.6% despite being asymptomatic. This is the highest recorded hookah-related carboxyhemoglobin concentration in the medical literature; and the significant chronic carboxyhemoglobinemia explained his polycythemia. This case illustrates that a social history is crucial when assessing the patient with severe carboxyhemoglobinemia as HBO is not indicated in chronic CO poisoning in an asymptomatic patient.


Assuntos
Intoxicação por Monóxido de Carbono , Oxigenoterapia Hiperbárica , Policitemia , Cachimbos de Água , Monóxido de Carbono , Intoxicação por Monóxido de Carbono/complicações , Intoxicação por Monóxido de Carbono/terapia , Carboxihemoglobina , Humanos , Masculino , Policitemia/complicações , Policitemia/terapia , Fumar
10.
J Emerg Med ; 62(2): 175-181, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34538516

RESUMO

BACKGROUND: Bupropion is an antidepressant medication with expanding indications including smoking cessation, weight loss, attention-deficit/hyperactivity disorder, seasonal affective disorder, and amphetamine dependence. Despite its increasing popularity among providers, it has a well-known narrow therapeutic window that can lead to delayed onset of symptoms with extended-release formulations and devastating consequences in overdose. We have noticed some patients misusing bupropion via insufflation, which added a layer of complexity with regards to the therapeutic application of the drug. This route of use created difficult decisions regarding clinical monitoring in these patients. OBJECTIVES: To determine if prolonged observation is required after insufflation of bupropion and to further describe effects from this route of use. METHODS: This is a retrospective observational study reviewing all the cases of insufflated bupropion use reported to a single poison center without any other coingestants. RESULTS: The majority (85.7%) of patients had mild or moderate effects, and seizures occurred in 19.6% of cases; and the vast majority of patients were symptomatic by the time of the initial call to the poison center. We did not encounter any delayed effects after this route of use. CONCLUSIONS: This report describes the clinical effects reported, and the timing of these effects, after insufflation of bupropion.


Assuntos
Antidepressivos de Segunda Geração , Insuflação , Venenos , Antidepressivos de Segunda Geração/efeitos adversos , Bupropiona/efeitos adversos , Humanos , Convulsões/induzido quimicamente
11.
Am J Emerg Med ; 47: 86-89, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33794474

RESUMO

Bupropion is an antidepressant medication with expanding indications including smoking cessation, weight loss, attention-deficit/hyperactivity disorder, seasonal affective disorder, and amphetamine dependence. Despite its increasing popularity among providers, it has a well-known narrow therapeutic window which can lead to delayed onset of symptoms with extended-release formulations and devastating consequences in overdose. We have noticed some patients misusing bupropion via intravenous use and had difficulty guiding decisions regarding clinical monitoring in these patients. As this route entirely changes the kinetics of bupropion, this has caused concern within our group. We reviewed all the cases of intravenous bupropion use reported to a single poison center without any other coingestants. The majority (66.7%) of patients had moderate effects and one patient had a seizure. No deaths were reported. All patients were symptomatic by the time of initial call to the poison center if they had any reported symptoms due to bupropion. This case series describes the clinical effects reported, and the timing of these effects, after intravenous bupropion use.


Assuntos
Bupropiona/efeitos adversos , Centros de Controle de Intoxicações , Abuso de Substâncias por Via Intravenosa/complicações , Adulto , Bupropiona/administração & dosagem , Bupropiona/intoxicação , Feminino , Humanos , Masculino , Estudos Retrospectivos , Adulto Jovem
13.
Am J Emerg Med ; 37(11): 2066-2071, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-30878413

RESUMO

BACKGROUND: Phenibut is a synthetically produced central nervous system (CNS) depressant that is structurally similar to the inhibitory neurotransmitter γ-aminobutyric acid (GABA). Phenibut has been identified as a drug of abuse with numerous clinical effects in overdose and a withdrawal syndrome with chronic use. The purpose of this study is to report the incidence of exposure calls regarding phenibut to a poison center, describe the reasons for its use and clinical effects. METHODS: Study subjects were identified using Toxicall®, the electronic medical record utilized by the Minnesota Poison Control System. All phenibut exposure calls from January 2000 through December 2018 were included. Analysis was performed on incidence of exposure calls, reported reasons for use, signs and symptoms, coingestants, and outcome. RESULTS: There were 56 exposure calls over 19 years with 48 (85.7%) calls within the past five years. Over 50% of patients had CNS effects and 10.7% had withdrawal concerns. Twenty-seven patients (48%) had abuse as the reason for use and 13 (23%) used phenibut to treat anxiety. There were documented coingestants in 35.7% of patients. No patients died due to reported phenibut use, though 11 patients (19.6%) were intubated. CONCLUSION: Exposure calls to a regional poison center regarding phenibut have increased over the past five years. CNS depression was common, and associated with significant clinical outcomes including respiratory failure requiring intubation. As phenibut is easily attainable and exposures appear to be increasing, physicians should be aware of phenibut-associated CNS and respiratory depression and be prepared to manage airways appropriately.


Assuntos
Depressores do Sistema Nervoso Central/intoxicação , Overdose de Drogas/epidemiologia , Centros de Controle de Intoxicações/estatística & dados numéricos , Ácido gama-Aminobutírico/análogos & derivados , Adulto , Idoso , Idoso de 80 Anos ou mais , Overdose de Drogas/diagnóstico , Overdose de Drogas/etiologia , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Minnesota/epidemiologia , Estudos Retrospectivos , Fatores de Risco , Ácido gama-Aminobutírico/intoxicação
14.
Am J Emerg Med ; 36(9): 1721.e1-1721.e2, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29861374

RESUMO

Metformin is a common and generally well-tolerated medication in the treatment of diabetes but rarely has been implicated as the cause for metformin-associated lactate acidosis. This is usually caused by decreased elimination from renal dysfunction but is rarely described after an acute ingestion. We present a case of an acute intentional overdose of metformin in a metformin-naïve patient without renal dysfunction. The patient gradually developed altered mental status, tachypnea, hypotension, hyperglycemia, hypoglycemia, hypothermia, and vasoplegic shock unresponsive to vasopressor support. Despite attempts at alkalinization, the patient developed a lactic acidosis with a pH of 6.9 and lactate of 33 mmol/L. Hemodialysis was performed with rapid improvement of clinical status. This case provides a clinical context in the acute setting and illustrates the rare need for extracorporeal support in this setting, which may be lifesaving.


Assuntos
Acidose Láctica/induzido quimicamente , Overdose de Drogas/terapia , Hipoglicemiantes/intoxicação , Metformina/intoxicação , Diálise Renal , Acidose Láctica/terapia , Feminino , Humanos , Diálise Renal/métodos , Adulto Jovem
16.
Am J Emerg Med ; 35(6): 899-903, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28438446

RESUMO

INTRODUCTION: Salicylate poisonings are common due to their multiple uses and wide availability. The variation of presenting symptoms contributes to inconsistent treatments in the emergency department. Patients with severe salicylate overdose require a high minute ventilation. Early in the course of an overdose, a patient will require hyperventilation. If they become too fatigued to compensate, mechanical ventilation may be needed. It can be impossible to recreate such a high minute ventilation with mechanical ventilation. This places patients at a high risk for decompensation and death. Hemodialysis is an effective elimination technique for salicylate overdose and should be considered early. METHODS: All salicylate cases reported to the Illinois Poison Center were reviewed from 2003-2014. All intubated patients with a salicylate level >50mg/dl were included for analysis. Survival was compared to measured serum salicylate level and the administration of hemodialysis. RESULTS: 56 Cases were identified with an overall survival rate of 73.2% in patients with a serum salicylate level >50mg/dl. When patients did not receive hemodialysis, a peak salicylate level >50mg/dl had a 56% survival rate and 0% survival when the level was >80mg/dl. In the patients who received hemodialysis, a peak salicylate level >50mg/dl had a 83.9% survival rate and 83.3% survival when the level was >80mg/dl. CONCLUSION: Survival was decreased in these patients if hemodialysis was not performed. Mortality increases with the measured serum salicylate level. Timely hemodialysis for intubated salicylate overdose patients decreases mortality.


Assuntos
Anti-Inflamatórios não Esteroides/intoxicação , Overdose de Drogas/mortalidade , Overdose de Drogas/terapia , Diálise Renal , Salicilatos/intoxicação , Serviço Hospitalar de Emergência , Humanos , Illinois , Respiração Artificial , Estudos Retrospectivos , Taxa de Sobrevida
17.
Clin Toxicol (Phila) ; 55(7): 617-623, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28346007

RESUMO

INTRODUCTION: The Lipid Emulsion Therapy workgroup, organized by the American Academy of Clinical Toxicology, recently conducted a systematic review, which subjectively evaluated lipid emulsion as a treatment for local anesthetic toxicity. We re-extracted data and conducted a meta-analysis of survival in animal models. METHODS: We extracted survival data from 26 publications and conducted a random-effect meta-analysis based on odds ratio weighted by inverse variance. We assessed the benefit of lipid emulsion as an independent variable in resuscitative models (16 studies). We measured Cochran's Q for heterogeneity and I2 to determine variance contributed by heterogeneity. Finally, we conducted a funnel plot analysis and Egger's test to assess for publication bias in studies. RESULTS: Lipid emulsion reduced the odds of death in resuscitative models (OR =0.24; 95%CI: 0.1-0.56, p = .0012). Heterogeneity analysis indicated a homogenous distribution. Funnel plot analysis did not indicate publication bias in experimental models. DISCUSSION: Meta-analysis of animal data supports the use of lipid emulsion (in combination with other resuscitative measures) for the treatment of local anesthetic toxicity, specifically from bupivacaine. Our conclusion differed from the original review. Analysis of outliers reinforced the need for good life support measures (securement of airway and chest compressions) along with prompt treatment with lipid.


Assuntos
Anestésicos Locais/toxicidade , Bupivacaína/toxicidade , Emulsões Gordurosas Intravenosas/farmacologia , Intoxicação/tratamento farmacológico , Ressuscitação/métodos , Animais , Terapia Combinada , Modelos Animais de Doenças , Cães , Composição de Medicamentos , Emulsões , Emulsões Gordurosas Intravenosas/química , Razão de Chances , Intoxicação/etiologia , Intoxicação/fisiopatologia , Coelhos , Ratos , Medição de Risco , Fatores de Risco , Suínos , Fatores de Tempo
18.
Otolaryngol Clin North Am ; 46(6): 1137-49, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24262965

RESUMO

Aspiration risk from dysphagia increases with central and peripheral neurologic disease. Stroke, microvascular ischemic disease, a spectrum of neurodegenerative diseases, and advancing dementia all have unique aspects. However, there are distinct commonalities in this population. Increasing nutritional requirements to stave off oropharyngeal muscular atrophy and a sedentary lifestyle further tax the patient's abilities to safely swallow. This article reviews stroke, muscular dystrophy, myasthenia gravis, multiple sclerosis, amyotrophic lateral sclerosis, Parkinson's disease, and advanced dementia. Approaches to screening and evaluation, recognizing sentinel indicators of decline that increase aspiration risk, and options for managing global laryngeal dysfunction are also presented.


Assuntos
Transtornos de Deglutição , Demência/complicações , Doenças do Sistema Nervoso/complicações , Aspiração Respiratória/prevenção & controle , Acidente Vascular Cerebral/complicações , Fatores Etários , Transtornos de Deglutição/diagnóstico , Transtornos de Deglutição/etiologia , Transtornos de Deglutição/fisiopatologia , Transtornos de Deglutição/psicologia , Transtornos de Deglutição/terapia , Gerenciamento Clínico , Humanos , Competência Mental , Estado Nutricional , Medição de Risco , Fatores de Risco , Índice de Gravidade de Doença , Sistema Estomatognático/fisiopatologia
19.
Arthritis Rheum ; 64(11): 3626-3637, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22777600

RESUMO

OBJECTIVE: Hypocellularity resulting from chondrocyte death in the aftermath of mechanical injury is thought to contribute to posttraumatic osteoarthritis. However, we observed that nonviable areas in cartilage injured by blunt impact were repopulated within 7-14 days by cells that appeared to migrate from the surrounding matrix. The aim of this study was to assess our hypothesis that the migrating cell population included chondrogenic progenitor cells that were drawn to injured cartilage by alarmins. METHODS: Osteochondral explants obtained from mature cattle were injured by blunt impact or scratching, resulting in localized chondrocyte death. Injured sites were serially imaged by confocal microscopy, and migrating cells were evaluated for chondrogenic progenitor characteristics. Chemotaxis assays were used to measure the responses to chemokines, injury-conditioned medium, dead cell debris, and high mobility group box chromosomal protein 1 (HMGB-1). RESULTS: Migrating cells were highly clonogenic and multipotent and expressed markers associated with chondrogenic progenitor cells. Compared with chondrocytes, these cells overexpressed genes involved in proliferation and migration and underexpressed cartilage matrix genes. They were more active than chondrocytes in chemotaxis assays and responded to cell lysates, conditioned medium, and HMGB-1. Glycyrrhizin, a chelator of HMGB-1 and a blocking antibody to receptor for advanced glycation end products (RAGE), inhibited responses to cell debris and conditioned medium and reduced the numbers of migrating cells on injured explants. CONCLUSION: Injuries that caused chondrocyte death stimulated the emergence and homing of chondrogenic progenitor cells, in part via HMGB-1 release and RAGE-mediated chemotaxis. Their repopulation of the matrix could promote the repair of chondral damage that might otherwise contribute to progressive cartilage loss.


Assuntos
Cartilagem Articular/lesões , Condrócitos/citologia , Células-Tronco Multipotentes/citologia , Osteoartrite do Joelho/patologia , Joelho de Quadrúpedes/lesões , Animais , Apoptose/fisiologia , Cartilagem Articular/patologia , Bovinos , Diferenciação Celular/fisiologia , Movimento Celular/fisiologia , Células Cultivadas , Condrócitos/fisiologia , Células-Tronco Multipotentes/fisiologia , Osteoartrite do Joelho/etiologia , Joelho de Quadrúpedes/patologia , Transcriptoma , Ferimentos não Penetrantes/patologia
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