Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 17 de 17
Filtrar
1.
J Electrocardiol ; 73: 1-7, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35524997

RESUMO

BACKGROUNDS: An adverse increased risk of atrial fibrillation (AF) can be detected by measuring the p-wave indices, including prolonged p-wave duration, the PR interval, abnormal p-wave terminal force, and abnormal p-wave axis (aPWA). Our purpose was to characterize the AF patient population with an aPWA and to identify whether the aPWA was associated with recurrence after catheter ablation of AF. METHODS: This study retrospectively included 249 patients with AF who underwent catheter ablation in our hospital from October 2015 to May 2019. We measured the p-wave indices and left atrial cavity size (LAVI) before the catheter ablation. A logistic regression analysis was performed to analyze the concurrent effects of various factors on the prevalence of AF recurrence over 12 months after the ablation. RESULTS: An aPWA was observed in 35 patients (14%). There were significantly more patients with an aPWA in the non-PAF than PAF patients (26% versus 7%, p < 0.001). The patients with an aPWA had a significantly larger LAVI values (37 ± 12 versus 45 ± 11 ml/m2, p = 0.016). In a multivariate analysis, an aPWA (odds ratio, 4.27; 95% confidence interval, 1.75-10.4; p = 0.001) and the LAVI (odds ratio, 1.04; 95% confidence interval, 1.00-1.08; p = 0.032) were independently associated with recurrence after catheter ablation. CONCLUSIONS: Our results demonstrated that measuring the aPWA in patients with atrial fibrillation before ablation was useful for identifying patients at a higher risk of recurrence after catheter ablation of AF.


Assuntos
Fibrilação Atrial , Ablação por Cateter , Ablação por Cateter/métodos , Eletrocardiografia , Humanos , Recidiva , Estudos Retrospectivos , Resultado do Tratamento
2.
Artif Organs ; 45(12): 1533-1542, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34398471

RESUMO

The successful use of prolonged (ie, >28 days) veno-venous extracorporeal membrane oxygenation (V-V ECMO) is being increasingly reported. However, limited data are available on its outcomes. This study investigated the outcomes of acute respiratory distress syndrome (ARDS) patients on prolonged ECMO support. We retrospectively evaluated 57 patients requiring V-V ECMO for ARDS between 2015 and 2020. The patients were divided into two groups according to ECMO duration: (a) ≤28 days group (n = 43, 75%) or (b) >28 days (n = 14, 25%) group. Clinical characteristics, complications, and outcomes between these two groups were statistically compared. There were no significant differences in demographics, comorbidity, ARDS etiology, and severity scores between the two groups. However, the mechanical ventilation period before ECMO initiation was significantly longer in the >28 days group than in the ≤28 days group (10.5 days vs. 1 day; P < .05). The incidence of positive bacterial blood culture results during ECMO was significantly higher in the >28 days group than in the ≤28 days group (43% vs. 9%; P < .05). Additionally, the hospital survival rate was significantly lower in the >28 days group than in the ≤28 days ECMO group (21% vs. 60%; P < .05). Prolonged ECMO was associated with worse hospital survival outcomes. Early initiation of ECMO along with meticulous care and appropriate treatment against infection during ECMO could improve the hospital survival of ARDS patients on prolonged ECMO support.


Assuntos
Oxigenação por Membrana Extracorpórea/efeitos adversos , Síndrome do Desconforto Respiratório/mortalidade , Síndrome do Desconforto Respiratório/terapia , Adulto , Idoso , Hemocultura , Feminino , Mortalidade Hospitalar , Humanos , Masculino , Pessoa de Meia-Idade , Respiração Artificial/estatística & dados numéricos , Estudos Retrospectivos , Fatores de Tempo
3.
BMC Cardiovasc Disord ; 19(1): 316, 2019 12 30.
Artigo em Inglês | MEDLINE | ID: mdl-31888491

RESUMO

BACKGROUND: Non-cardiac surgery for hypertrophic obstructive cardiomyopathy (HOCM) is considered to require meticulous perioperative care. ß-blockers are considered the first-line drugs for patients with HOCM, and they play a key role in preventing cardiovascular complications in perioperative care. The bisoprolol transdermal patch has recently become available in Japan, and it is useful for patients who are unable to take oral medication during perioperative care. The aim of this case series was to assess the hemodynamic features of patients with HOCM who used the bisoprolol transdermal patch during perioperative care for non-cardiac surgery. METHODS: Between August 2016 and August 2018, we retrospectively analyzed 10 consecutive cases of HOCM with the patients using the bisoprolol transdermal patch during perioperative care. Hemodynamic and echocardiographic features were evaluated before and after patients were switched from oral bisoprolol to transdermal patch therapy or started transdermal patch therapy as a new ß-blocker medication. In addition, cardiovascular complications (all-cause death, cardiac death, heart failure, ventricular tachycardia, and ventricular fibrillation) during the perioperative period were evaluated. RESULTS: There was no significant change in the patients' heart rate, blood pressure, ejection fraction, and pressure gradient in the left ventricle after switching from oral bisoprolol to the transdermal patch therapy. On the other hand, patients who started using the bisoprolol transdermal patch as a new ß-blocker medication tended to have a decreased heart rate and pressure gradient thereafter, but there was no significant difference in blood pressure or ejection fraction. No cardiovascular complications occurred during the perioperative period. CONCLUSIONS: We described the utilization of the bisoprolol transdermal patch during perioperative care for non-cardiac surgery in patients with HOCM. We determined that the hemodynamic features of these patients did not change significantly after switching to patch therapy. Further, initiation of the bisoprolol transdermal patch as a new ß-blocker medication sufficiently tended to decrease the pressure gradient. This unique approach can be an alternate treatment option for HOCM. TRIAL REGISTRATION: The registry was registered in the University Hospital Medical Information Network Clinical Trials Registry (UMIN000036703). The date of registration was 10/5/2019 and it was "Retrospectively registered".


Assuntos
Antagonistas de Receptores Adrenérgicos beta 1/administração & dosagem , Bisoprolol/administração & dosagem , Cardiomiopatia Hipertrófica/tratamento farmacológico , Hemodinâmica/efeitos dos fármacos , Assistência Perioperatória , Administração Cutânea , Administração Oral , Antagonistas de Receptores Adrenérgicos beta 1/efeitos adversos , Bisoprolol/efeitos adversos , Cardiomiopatia Hipertrófica/diagnóstico por imagem , Cardiomiopatia Hipertrófica/fisiopatologia , Humanos , Assistência Perioperatória/efeitos adversos , Sistema de Registros , Estudos Retrospectivos , Fatores de Tempo , Adesivo Transdérmico , Resultado do Tratamento
4.
J Nippon Med Sch ; 91(3): 347-350, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38972748

RESUMO

Symptoms of catatonia include silence, motionlessness, and postural retention. Although it is important to detect and treat catatonia early, before it becomes severe, postoperative cases have inherent risks that hinder diagnosis and treatment. A 60-year-old man with schizophrenia underwent endoscopic/thoracoscopic esophagectomy and was extubated in the operating room. In the intensive care unit (ICU), he had stiffness in the neck, ankles, and knees, catalepsy during passive knee flexion, mild disturbance of consciousness, mild creatine kinase elevation, and respiratory depression. Intravenous diazepam was administered for diagnosis, and the patient's rapid improvement indicated catatonia. He was intubated and started on lorazepam; tapering produced no recurrence of symptoms. The patient was extubated and transferred to the general ward on postoperative Day 2. Because this patient was extubated in the operating room and was managed postoperatively in the ICU with a full-time doctor, his symptoms were easily recognized and early diagnosis was possible. Thus, we were able to administer drug therapy quickly and adequately and perform forward management that accounted for postoperative risks, thereby achieving a favorable outcome.


Assuntos
Catatonia , Diagnóstico Precoce , Lorazepam , Humanos , Masculino , Pessoa de Meia-Idade , Catatonia/diagnóstico , Catatonia/tratamento farmacológico , Lorazepam/administração & dosagem , Lorazepam/uso terapêutico , Esofagectomia , Resultado do Tratamento , Diazepam/administração & dosagem , Esquizofrenia/diagnóstico , Esquizofrenia/tratamento farmacológico , Complicações Pós-Operatórias/diagnóstico
5.
Acta Derm Venereol ; 93(3): 294-300, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23038099

RESUMO

Metallic copper has been shown significantly to reduce methicillin-resistant Staphylococcus aureus (MRSA) contamination of the ambient surroundings of the beds of MRSA-carrying patients in dermatology wards. The aim of this study was to determine whether a bed sheet made of copper-coated film will reduce the spread of MRSA contamination in the environment of a heavily-colonized patient. The bacterial count was highest on the bed sheet. MRSA cell counts on the surface of the non-film-coated control sheet were high (6,600-11,000 colony forming units (cfu)), but those on the copper film were considerably lower (20-130 cfu). Use of metallic copper on the bed sheets of patients who are likely to be a source of MRSA contamination may help to prevent the spread of MRSA contamination in hospital wards.


Assuntos
Ligas , Roupas de Cama, Mesa e Banho , Cobre , Infecção Hospitalar/prevenção & controle , Dermatologia , Contaminação de Equipamentos/prevenção & controle , Unidades Hospitalares , Controle de Infecções/métodos , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Infecções Cutâneas Estafilocócicas/prevenção & controle , Infecção Hospitalar/microbiologia , Infecção Hospitalar/transmissão , DNA Bacteriano/isolamento & purificação , Desenho de Equipamento , Feminino , Genótipo , Humanos , Staphylococcus aureus Resistente à Meticilina/genética , Staphylococcus aureus Resistente à Meticilina/patogenicidade , Pessoa de Meia-Idade , Fenótipo , Infecções Cutâneas Estafilocócicas/microbiologia , Infecções Cutâneas Estafilocócicas/transmissão , Resultado do Tratamento
6.
Circ J ; 76(11): 2586-91, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22850288

RESUMO

BACKGROUND: Because it remains unclear whether noninvasive ventilation (NIV) is an effective therapy for cardiogenic pulmonary edema secondary to acute myocardial infarction (AMI), we retrospectively evaluated our experience with NIV in the treatment of pulmonary edema secondary to AMI and other cardiac conditions. METHODS AND RESULTS: The study group included 206 patients with cardiogenic pulmonary edema, divided into an AMI group (53 patients) and a non-AMI group (153 patients). The weaning rate from NIV was similar in the AMI and non-AMI groups (90.6% vs. 90.8%, P=0.950). Heart rate, blood pressure, and respiratory rate decreased significantly 1h after initiation of NIV in both groups, and were maintained until weaning from NIV. The frequency of endotracheal intubation after weaning from NIV was higher in the AMI group than in the non-AMI group (7.5% vs. 0.7%, P=0.016), although the overall frequency of intubation was similar in both groups. The in-hospital mortality rate was similar in the AMI and non-AMI groups (13.1% vs. 9.8%, P=0.489). CONCLUSIONS: NIV effectively improved vital signs and oxygenation and lowered the intubation rate in patients with cardiogenic pulmonary edema of all etiologies, including AMI. The outcome in patients with AMI treated with NIV depends primarily on the severity of the course of AMI and not on the severity of acute respiratory failure.


Assuntos
Infarto do Miocárdio/complicações , Infarto do Miocárdio/terapia , Edema Pulmonar/etiologia , Edema Pulmonar/terapia , Idoso , Idoso de 80 Anos ou mais , Pressão Sanguínea , Feminino , Frequência Cardíaca , Mortalidade Hospitalar , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/mortalidade , Infarto do Miocárdio/fisiopatologia , Ventilação não Invasiva , Edema Pulmonar/mortalidade , Edema Pulmonar/fisiopatologia , Taxa Respiratória , Estudos Retrospectivos
7.
Int J Artif Organs ; 45(11): 927-935, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35982583

RESUMO

INTRODUCTION: Oxygenator exchange during extracorporeal membrane oxygenation (ECMO) is a life-threatening procedure. D-dimer has been used to predict oxygenator failure, but it is a parameter used a few days before oxygenator exchange. This study investigated parameters before and immediately after ECMO initiation that predict oxygenator exchange. METHODS: This was a single-center, retrospective study of 28 patients who received veno-venous ECMO with heparin/silicone-coated polypropylene oxygenator (NSH-R HPO-23WH-C; Senko Medical Inc., Tokyo, Japan), due to acute respiratory failure, from April 2015 to March 2020. Clinical data before ECMO initiation and during the first 3 days on ECMO were compared between the patients with oxygenator exchange (exchange group) and those without oxygenator exchange (non-exchange group). RESULTS: Nine (32%) patients required oxygenator exchange. The exchange group had significantly higher white blood cell count (WBC) (16,944 ± 2423/µL vs 10,342 ± 1442/µL, p < 0.05) and Acute Physiology and Chronic Health Evaluation (APACHE) II score (31 ± 5 vs 25 ± 8, p < 0.05) before ECMO initiation than the non-exchange group. The partial pressure of oxygen at the outlet of the oxygenator (PO2 outlet) and activated partial thromboplastin time (aPTT) during the first 3 days on ECMO were significantly lower in the exchange group than in the non-exchange group. CONCLUSIONS: High WBC and APACHE II score before ECMO initiation, low PO2 outlet, and aPTT during the first 3 days on ECMO were associated with oxygenator exchange during veno-venous ECMO. These parameters could be used to avoid unexpected oxygenator exchange.


Assuntos
Oxigenação por Membrana Extracorpórea , Oxigenação por Membrana Extracorpórea/efeitos adversos , Oxigenação por Membrana Extracorpórea/métodos , Heparina , Humanos , Oxigênio , Oxigenadores , Polipropilenos , Estudos Retrospectivos , Silicones
8.
Clin Cardiol ; 44(5): 683-691, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33724499

RESUMO

BACKGROUND: Insertable cardiac monitors (ICMs) improve diagnostic yield in patients with unexplained syncope. The most of cardiac syncope is arrhythmic causes include paroxysmal bradycardia and supraventricular tachycardia (SVT) in patients with unexplained syncope receiving ICM. Predictors for bradycardia and SVT that necessitate therapy in patients with unexplained syncope are not well known. HYPOTHESIS: This study aimed to investigate predictors of bradycardia and SVT necessitating therapy in patients with unexplained syncope receiving ICMs. METHODS: We retrospectively reviewed medical records of consecutive patients who received ICMs to monitor unexplained syncope. We performed Cox's stepwise logistic regression analysis to identify significant independent predictors for bradycardia and SVT. RESULTS: One hundred thirty-two patients received ICMs to monitor unexplained syncope. During the 17-month follow-up period, 19 patients (14%) needed pacemaker therapy for bradycardia; 8 patients (6%) received catheter ablation for SVT. The total estimated diagnostic rates were 34% and 48% at 1 and 2 years, respectively. Stepwise logistic regression analysis indicated that syncope during effort (odds ratio [OR] = 3.41; 95% confidence interval [CI], 1.21 to 9.6; p = .02) was an independent predictor for bradycardia. Palpitation before syncope (OR = 9.46; 95% CI, 1.78 to 50.10; p = .008) and history of atrial fibrillation (OR = 10.1; 95% CI, 1.96 to 52.45; p = .006) were identified as significant independent predictors for SVT. CONCLUSION: Syncope during effort, and palpitations or history of atrial fibrillation were independent predictors for bradycardia and for SVT. ICMs are useful devices for diagnosing unexplained syncope.


Assuntos
Fibrilação Atrial , Bradicardia , Taquicardia Supraventricular , Idoso , Antagonistas de Receptores de Angiotensina , Inibidores da Enzima Conversora de Angiotensina , Bradicardia/diagnóstico , Bradicardia/terapia , Eletrocardiografia Ambulatorial , Humanos , Masculino , Estudos Retrospectivos , Síncope/diagnóstico , Síncope/etiologia , Síncope/terapia , Taquicardia Supraventricular/diagnóstico , Taquicardia Supraventricular/terapia
9.
J Cardiol Cases ; 21(4): 149-152, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32256864

RESUMO

Pacemaker implantations are minimally invasive procedures commonly used for patients with bradycardic arrhythmias. Takotsubo cardiomyopathy, which is usually induced by life-threatening stress hardly ever occurs after this minimally invasive procedure. Here, we experienced a patient who developed takotsubo cardiomyopathy leading to ventricular fibrillation the day after a pacemaker implantation. At that time, a cardiac echocardiogram and left ventriculogram revealed hypercontraction of the base of the heart and a decreased contraction of the apex. A coronary angiogram revealed no significant coronary stenosis. Ten days later, the electrocardiogram findings normalized, and an echocardiogram revealed that the left ventricular function had fully recovered. Therefore, we diagnosed this patient with takotsubo cardiomyopathy. In general, pacemaker implantations are routine procedures and fatal complications are low. We report a case that developed potentially fatal complications after a pacemaker implantation. .

10.
J Nippon Med Sch ; 87(1): 32-36, 2020 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-31308316

RESUMO

Intravascular lymphoma is a rare disease that progresses to multiple organ dysfunction caused primarily by tumor cell proliferation in small blood vessels. Few studies have investigated critical care management of intravascular lymphoma. We describe a rare case of multiple organ failure due to intravascular lymphoma with severe lactic acidosis in a patient who survived. A 64-year-old man with impaired consciousness was diagnosed as having intravascular large B-cell lymphoma by means of a random skin biopsy. The patient arrived at our hospital's intensive care unit (ICU) with impaired consciousness, respiratory failure that required mechanical ventilation, and lactic acidosis that required renal replacement therapy. Mechanical ventilation and renal replacement therapy were continued in the ICU, and his respiratory status and circulatory dynamics eventually stabilized. However, his impaired consciousness and hyperlactatemia did not improve until after the start of chemotherapy with doxorubicin, cyclophosphamide, vincristine, prednisolone, and rituximab. Although he developed tumor lysis syndrome immediately after chemotherapy, his systemic condition was gradually stabilized by continued critical care management primarily comprising renal replacement therapy. He was weaned from ventilator support after a tracheotomy and moved to the general ward. Hematopoietic malignancy with hyperlactatemia has a very poor prognosis; however, hyperlactatemia and impaired consciousness were dramatically improved in this patient by critical care management and chemotherapy.


Assuntos
Acidose/terapia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Cuidados Críticos , Ácido Láctico , Linfoma Difuso de Grandes Células B/complicações , Síndrome de Lise Tumoral/etiologia , Neoplasias Vasculares/complicações , Acidose/etiologia , Ciclofosfamida/administração & dosagem , Doxorrubicina/administração & dosagem , Humanos , Masculino , Pessoa de Meia-Idade , Insuficiência de Múltiplos Órgãos/etiologia , Prednisolona/administração & dosagem , Terapia de Substituição Renal , Rituximab/administração & dosagem , Índice de Gravidade de Doença , Síndrome de Lise Tumoral/terapia , Neoplasias Vasculares/terapia , Vincristina/administração & dosagem
11.
J Arrhythm ; 35(2): 230-237, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31007787

RESUMO

BACKGROUND: Left atrial (LA) dilation is associated with morbidity of atrial fibrillation (AF). However, little is known about pulmonary vein (PV) dilation. PURPOSE: We investigated the PV volume in the patients with AF. METHODS AND RESULTS: We performed 3dimensional computed tomography (3DCT) in 155 patients and divided them into three groups: 19 patients without AF (non-AF group, mean age 66 ± 12 years), 50 with paroxysmal AF (PAF group, mean age 67 ± 8 years) and 24 with persistent AF (PeAF group, mean age 64 ± 10 years). The absence of AF was diagnosed in patients with a cardiac implantable electronic device for at least 1 year (mean: 59 ± 37 months). We determined the PV volume as the total volume from the orifice to the first branch of each PV. According to the echocardiographic data, the LA dimension (LAD) and LA volume index (LAVI) were largest in the PeAF group followed by the PAF and non-AF group. According to the morphometric data obtained on 3D-CT, the PV volume was similar in PeAF and PAF groups but significantly smaller in the non-AF group (median value: 24 vs 21 vs 14 mL, respectively). According to the receiver operating characteristic curve analysis, the area under the curve for the PV volume in the presence of AF was 0.80, and the optimum cut-off value was 17 mL (sensitivity 74%, specificity 80%). CONCLUSION: The PV volume might be useful for predicting the presence of AF before increases in the LAD and LAVI on echocardiography.

13.
J Nippon Med Sch ; 72(1): 52-9, 2005 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15834208

RESUMO

Limited information is available about histopathological reactions to the implanted endocardial electrodes of pacemakers (PM). Gross anatomic and histologic studies of tissue reactions to PM electrodes were made in thirteen autopsy cases (nine men and four women, ages 25 approximately 89 years, mean age 71.8) who died two months to twenty-one years after PM implantation. Nine of them had complete atrioventricular (AV) block, three had sick sinus syndrome, and one had bradycardia-tachycardia syndrome. The direct causes of death were not related to their PM. The tip with projecting tines was implanted in the right ventricle in all patients. At the contact area between the electrode and the endocardium, no tissue reaction was observed in one patient with a history of over sixteen years of PM implantation. However, cardiomyocytes under the tip had been replaced by fibrotic tissue in many other patients. In two patients in particular where the electrode had been implanted at the apex of each right ventricle, all cardiomyocytes had disappeared and only fibrotic tissue and adipose tissue were observed under the tip. These findings suggest that mechanical stress caused by attaching the tip tightly damages cardiomyocytes and brings about changes in the pacing thresholds. In three patients, a space was seen between the tip and the endocardium. A fibrous sheath covering the electrode extended to the tip and formed a thick fibrous cap. This non-excitable fibrous cap acted as a virtual electrode and possibly affected the elevation of the threshold in these patients. In four patients, extensive myocardial fibrosis due to disease, e. g. previous myocardial infarction, dilated cardiomyopathy, amyloidosis, or sarcoidosis, was found in the area surrounding the tip and also might affect the elevation of the threshold. We concluded that elevation of pacing thresholds after PM implantation is not due to reactive endocardial thickening. The space between the tip and the endocardium is occupied by a fibrous sheath, and an overly tight attachment damages cardiomyocytes causing replacement fibrosis. Thus, it is not desirable in some patients to insert the electrodes into the apex, where the myocardium is thin. To avoid the elevation of thresholds, development of further devices is necessary to allow electrode fixation to the endocardium with a more suitable pressure level.


Assuntos
Eletrodos Implantados/efeitos adversos , Endocárdio/patologia , Marca-Passo Artificial/efeitos adversos , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Fibrose , Cardiopatias/patologia , Cardiopatias/terapia , Humanos , Masculino , Pessoa de Meia-Idade , Miócitos Cardíacos/patologia , Estresse Mecânico
14.
Respir Med Case Rep ; 8: 10-3, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-26029606

RESUMO

Disseminated non-tuberculous mycobacterium (dNTM) infection is rare in humans without human immunodeficiency virus (HIV) infection. Previous reports have shown autoantibodies to human interferon-gamma (IFN-γ), which play important roles in mycobacterium infection, in the sera of patients with non-HIV dNTM disease. Herein, we describe a 53-year-old male who was strongly suspected to have multicentric Castleman disease (MCD) based on bone marrow study and chest radiological findings. However, Mycobacterium kansasii was detected in respiratory samples including pleural effusion. We initiated anti-mycobacterial therapy under intensive care; he died on the 48(th) hospital day. We detected no hematological disorders, ruling out MCD postmortem. However, we detected M. kansasii in pulmonary, liver, spleen and bone marrow tissues. Moreover, anti-IFN-γ autoantibody was detected with strong neutralizing capacity for IFN-γ. We consider our present report to contribute to understanding of the relationship between anti-IFN-γ autoantibody and disease development.

17.
Neurosci Res ; 70(1): 35-43, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21238509

RESUMO

The rostral ventromedial medulla (RVM) is a major region for the descending modulation of pain at the spinal cord level, and neurons in the RVM have been implicated in the inhibition and facilitation of spinal nociceptive transmission. Although recent studies have established that the RVM facilitation of nociceptive transmission in the spinal cord contributes to neuropathic pain, the underlying mechanisms remain largely unknown. In the present study, we investigated the effects of kainic acid (KA)-induced RVM damage on neuropathic pain behavior and the expression of molecules implicated in pain modulation. KA was injected into the RVM midline region after neuropathic pain was established by chronic constrictive injury of the left sciatic nerve. Thermal hyperalgesia, but not mechanical allodynia, was persistently suppressed in the ipsilateral paw by a single KA injection into the RVM for at least the next 7 days in a rat neuropathic pain model. KA injection alone did not affect the nocifensive responses to mechanical and thermal stimuli on the intact side. Immunohistochemical analysis revealed that KA injection into the RVM significantly reduced the number of immunoreactive neurons for µ-opioid receptors, but not tryptophan hydroxylase, in association with the analgesic effect. These results suggest that a subset of RVM neurons expressing µ-opioid receptors contribute to the maintenance of thermal hyperalgesia in neuropathic pain.


Assuntos
Hiperalgesia/fisiopatologia , Bulbo/fisiologia , Neurônios/fisiologia , Doenças do Sistema Nervoso Periférico/fisiopatologia , Receptores Opioides mu/fisiologia , Animais , Modelos Animais de Doenças , Regulação para Baixo/efeitos dos fármacos , Regulação para Baixo/fisiologia , Hiperalgesia/metabolismo , Masculino , Bulbo/citologia , Bulbo/efeitos dos fármacos , Inibição Neural/efeitos dos fármacos , Inibição Neural/fisiologia , Neurônios/efeitos dos fármacos , Dor/metabolismo , Dor/patologia , Dor/fisiopatologia , Doenças do Sistema Nervoso Periférico/metabolismo , Ratos , Ratos Sprague-Dawley , Receptores Opioides mu/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA