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1.
Endocrinology ; 164(12)2023 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-37897495

RESUMO

Breast tumors overexpressing human epidermal growth factor receptor (HER2) confer intrinsic resistance to endocrine therapy (ET), and patients with HER2/estrogen receptor-positive (HER2+/ER+) breast cancer (BCa) are less responsive to ET than HER2-/ER+. However, real-world evidence reveals that a large subset of patients with HER2+/ER+ receive ET as monotherapy, positioning this treatment pattern as a clinical challenge. In the present study, we developed and characterized 2 in vitro models of ET-resistant (ETR) HER2+/ER+ BCa to identify possible therapeutic vulnerabilities. To mimic ETR to aromatase inhibitors (AIs), we developed 2 long-term estrogen deprivation (LTED) cell lines from BT-474 (BT474) and MDA-MB-361 (MM361). Growth assays, PAM50 subtyping, and genomic and transcriptomic analyses, followed by validation and functional studies, were used to identify targetable differences between ET-responsive parental and ETR-LTED HER2+/ER+ cells. Compared to their parental cells, MM361 LTEDs grew faster, lost ER, and increased HER2 expression, whereas BT474 LTEDs grew slower and maintained ER and HER2 expression. Both LTED variants had reduced responsiveness to fulvestrant. Whole-genome sequencing of aggressive MM361 LTEDs identified mutations in genes encoding transcription factors and chromatin modifiers. Single-cell RNA sequencing demonstrated a shift towards non-luminal phenotypes, and revealed metabolic remodeling of MM361 LTEDs, with upregulated lipid metabolism and ferroptosis-associated antioxidant genes, including GPX4. Combining a GPX4 inhibitor with anti-HER2 agents induced significant cell death in both MM361 and BT474 LTEDs. The BT474 and MM361 AI-resistant models capture distinct phenotypes of HER2+/ER+ BCa and identify altered lipid metabolism and ferroptosis remodeling as vulnerabilities of this type of ETR BCa.


Assuntos
Neoplasias da Mama , Humanos , Feminino , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Resistencia a Medicamentos Antineoplásicos/genética , Fulvestranto/farmacologia , Fulvestranto/uso terapêutico , Inibidores da Aromatase/farmacologia , Inibidores da Aromatase/uso terapêutico , Estrogênios/metabolismo , Linhagem Celular Tumoral , Receptor ErbB-2/genética , Receptor ErbB-2/metabolismo
2.
bioRxiv ; 2023 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-37662291

RESUMO

Background: Breast tumors overexpressing human epidermal growth factor receptor (HER2) confer intrinsic resistance to endocrine therapy (ET), and patients with HER2/ estrogen receptor-positive (HER2+/HR+) breast cancer (BCa) are less responsive to ET than HER2-/ER+. However, real-world evidence reveals that a large subset of HER2+/ER+ patients receive ET as monotherapy, positioning this treatment pattern as a clinical challenge. In the present study, we developed and characterized two distinct in vitro models of ET-resistant (ETR) HER2+/ER+ BCa to identify possible therapeutic vulnerabilities. Methods: To mimic ETR to aromatase inhibitors (AI), we developed two long-term estrogen-deprived (LTED) cell lines from BT-474 (BT474) and MDA-MB-361 (MM361). Growth assays, PAM50 molecular subtyping, genomic and transcriptomic analyses, followed by validation and functional studies, were used to identify targetable differences between ET-responsive parental and ETR-LTED HER2+/ER+ cells. Results: Compared to their parental cells, MM361 LTEDs grew faster, lost ER, and increased HER2 expression, whereas BT474 LTEDs grew slower and maintained ER and HER2 expression. Both LTED variants had reduced responsiveness to fulvestrant. Whole-genome sequencing of the more aggressive MM361 LTED model system identified exonic mutations in genes encoding transcription factors and chromatin modifiers. Single-cell RNA sequencing demonstrated a shift towards non-luminal phenotypes, and revealed metabolic remodeling of MM361 LTEDs, with upregulated lipid metabolism and antioxidant genes associated with ferroptosis, including GPX4. Combining the GPX4 inhibitor RSL3 with anti-HER2 agents induced significant cell death in both the MM361 and BT474 LTEDs. Conclusions: The BT474 and MM361 AI-resistant models capture distinct phenotypes of HER2+/ER+ BCa and identify altered lipid metabolism and ferroptosis remodeling as vulnerabilities of this type of ETR BCa.

3.
Anesth Analg ; 133(1): 196-204, 2021 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-33720906

RESUMO

BACKGROUND: Obstructive sleep apnea (OSA) has been found to be associated with difficult airway, although there is a paucity of prospective studies investigating thresholds of OSA severity with difficult airway outcomes. The aim of this study was to examine the association between OSA and difficult intubation or difficult mask ventilation. We also explored the utility of the Snoring, Tiredness, Observed apnea, high blood Pressure, Body mass index, Age, Neck circumference, and Gender (STOP-Bang) score for difficult airway prediction. METHODS: The Postoperative Vascular Complications in Unrecognized Obstructive Sleep Apnea (POSA) trial was an international prospective cohort study of surgical patients 45 years or older with one or more cardiac risk factor presenting for noncardiac surgery, with planned secondary analyses of difficult airway outcomes. Multivariable logistic regression analyses tested associations between OSA severity and predictors of difficult airway with difficult intubation or difficult mask ventilation. Overall, 869 patients without prior diagnosis of OSA were screened for OSA risk with the STOP-Bang tool, underwent preoperative sleep study, and had routine perioperative care, including general anesthesia with tracheal intubation. The primary outcome analyzed was difficult intubation, and the secondary outcome was difficult mask ventilation. RESULTS: Based on the sleep studies, 287 (33%), 324 (37%), 169 (20%), and 89 (10%) of the 869 patients had no, mild, moderate, and severe OSA, respectively. One hundred and seventy-two (20%) had a STOP-Bang score of 0-2 (low risk), 483 (55%) had a STOP-Bang score of 3-4 (intermediate risk), and 214 (25%) had a STOP-Bang score 5-8 (high risk). The incidence of difficult intubation was 6.7% (58 of 869), and difficult mask ventilation was 3.7% (32 of 869). Multivariable logistic regression demonstrated that moderate OSA (odds ratio [OR] = 3.26 [95% confidence interval {CI}, 1.37-8.38], adjusted P = .010) and severe OSA (OR = 4.05 [95% CI, 1.51-11.36], adjusted P = .006) but not mild OSA were independently associated with difficult intubation compared to patients without OSA. Relative to scores of 0-2, STOP-Bang scores of 3-4 and 5-8 were associated with increased odds of difficult intubation (OR = 3.01 [95% CI, 1.13-10.40, adjusted P = .046] and 4.38 [95% CI, 1.46-16.36, adjusted P = .014]), respectively. OSA was not associated with difficult mask ventilation, and only increasing neck circumference was found to be associated (adjusted P = .002). CONCLUSIONS: Moderate and severe OSA were associated with difficult intubation, and increasing neck circumference was associated with difficult mask ventilation. A higher STOP-Bang score of 3 or more may be associated with difficult intubation versus STOP-Bang score of 0-2. Anesthesiologists should be vigilant for difficult intubation when managing patients suspected or diagnosed with OSA.


Assuntos
Manuseio das Vias Aéreas/métodos , Intubação Intratraqueal/métodos , Apneia Obstrutiva do Sono/fisiopatologia , Apneia Obstrutiva do Sono/cirurgia , Idoso , Manuseio das Vias Aéreas/efeitos adversos , Índice de Massa Corporal , Estudos de Coortes , Feminino , Humanos , Intubação Intratraqueal/efeitos adversos , Máscaras Laríngeas/efeitos adversos , Masculino , Pessoa de Meia-Idade , Pescoço , Estudos Prospectivos
4.
J Clin Sleep Med ; 17(3): 521-532, 2021 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-33112227

RESUMO

STUDY OBJECTIVES: The STOP-Bang questionnaire is a concise and easy screening tool for obstructive sleep apnea (OSA). Using modified body mass index (BMI), we assessed the diagnostic performance of the STOP-Bang questionnaire in predicting OSA in ethnically different groups of patients undergoing surgery. METHODS: This was a multicenter prospective cohort study involving patients with cardiovascular risk factors who were undergoing major noncardiac surgery. Patients underwent home sleep apnea testing. All patients completed the STOP-Bang questionnaire. The predictive parameters of STOP-Bang scores were calculated against the apnea-hypopnea index. RESULTS: From 4 ethnic groups 1,205 patients (666 Chinese, 161 Indian, 195 Malay, and 183 Caucasian) were included in the study. The mean BMI ranged from 25 ± 4 to 30 ± 6 kg/m² and mean age ranged from 64 ± 8 to 71 ± 10 years. For the Chinese and Indian patients, diagnostic parameters are presented using BMI threshold of 27.5 kg/m² with the area under curve to predict moderate-to-severe OSA being 0.709 (0.665-0.753) and 0.722 (0.635-0.808), respectively. For the Malay and Caucasian, diagnostic parameters are presented using BMI threshold of 35 kg/m² with the area under curve for predicting moderate-to-severe OSA being 0.645 (0.572-0.720) and 0.657 (0.578-0.736), respectively. Balancing the sensitivity and specificity, the optimal STOP-Bang thresholds for the Chinese, Indian, Malay, and Caucasian groups were determined to be 4 or greater. CONCLUSIONS: For predicting moderate-to-severe OSA, we recommend BMI threshold of 27.5 kg/m² for Chinese and Indian patients and 35 kg/m² for Malay and Caucasian patients. The optimal STOP-Bang threshold for the Chinese, Indian, Malay and Caucasian groups is 4 or greater. CLINICAL TRIAL REGISTRATION: Registry: ClinicalTrials.gov; Name: Postoperative Vascular Events in Unrecognized Obstructive Sleep Apnea; URL: https://clinicaltrials.gov/ct2/show/study/NCT01494181; Identifier: NCT01494181.


Assuntos
Etnicidade , Apneia Obstrutiva do Sono , Idoso , Idoso de 80 Anos ou mais , Humanos , Programas de Rastreamento , Pessoa de Meia-Idade , Polissonografia , Estudos Prospectivos , Inquéritos e Questionários
5.
J Card Surg ; 35(12): 3650-3652, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33135241

RESUMO

INTRODUCTION: In this report we describe the clinical presentation, laboratory findings and outcomes of four patients that were referred for urgent cardiothoracic intervention and tested positive for COVID-19. METHODS: The St. Elizabeth's Medical Center Institutional Review Board exempted the study from review (waived review). In each case, verbal informed consent was obtained by the study participant or health care proxy. RESULTS: The majority of the patients undergoing surgery had low Society of Thoracic Surgeons score and uneventful operating time. The mortality was very high and driven primarily by the viral syndrome. Laboratory markers that have been associated with disease severity in the general population were also prognostic in our population. CONCLUSION: Our study shows that these patients have very high mortality, whereas prevention and preoperative screening is required in preventing nosocomial spreading of the disease.


Assuntos
COVID-19/epidemiologia , Procedimentos Cirúrgicos Cardíacos/métodos , Cardiopatias/cirurgia , Pandemias , Idoso , Idoso de 80 Anos ou mais , Comorbidade , Evolução Fatal , Feminino , Cardiopatias/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade
6.
JCI Insight ; 4(20)2019 10 17.
Artigo em Inglês | MEDLINE | ID: mdl-31513547

RESUMO

Epicardial adipose tissue (EAT) is the visceral fat depot of the heart. Inflammation of EAT is thought to contribute to coronary artery disease (CAD). Therefore, we hypothesized that the EAT of patients with CAD would have increased inflammatory gene expression compared with controls without CAD. Cardiac surgery patients with (n = 13) or without CAD (n = 13) were consented, and samples of EAT and subcutaneous adipose tissue (SAT) were obtained. Transcriptomic analysis was performed using Affymetrix Human Gene 1.0 ST arrays. Differential expression was defined as a 1.5-fold change (ANOVA P < 0.05). Six hundred ninety-three genes were differentially expressed between SAT and EAT in controls and 805 in cases. Expression of 326 genes was different between EAT of cases and controls; expression of 14 genes was increased in cases, while 312 were increased in controls. Quantitative reverse transcription PCR confirmed that there was no difference in expression of CCL2, CCR2, TNF-α, IL-6, IL-8, and PAI1 between groups. Immunohistochemistry showed more macrophages in EAT than SAT, but there was no difference in their number or activation state between groups. In contrast to prior studies, we did not find increased inflammatory gene expression in the EAT of patients with CAD. We conclude that the specific adipose tissue depot, rather than CAD status, is responsible for the majority of differential gene expression.


Assuntos
Doença da Artéria Coronariana/imunologia , Mediadores da Inflamação/metabolismo , Gordura Intra-Abdominal/patologia , Pericárdio/patologia , Idoso , Angiografia Coronária , Doença da Artéria Coronariana/diagnóstico , Doença da Artéria Coronariana/patologia , Doença da Artéria Coronariana/cirurgia , Feminino , Perfilação da Expressão Gênica , Humanos , Gordura Intra-Abdominal/imunologia , Gordura Intra-Abdominal/cirurgia , Masculino , Pessoa de Meia-Idade , Análise de Sequência com Séries de Oligonucleotídeos , Pericárdio/imunologia , Pericárdio/cirurgia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Gordura Subcutânea/imunologia , Gordura Subcutânea/metabolismo
7.
JAMA ; 321(18): 1788-1798, 2019 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-31087023

RESUMO

Importance: Unrecognized obstructive sleep apnea increases cardiovascular risks in the general population, but whether obstructive sleep apnea poses a similar risk in the perioperative period remains uncertain. Objectives: To determine the association between obstructive sleep apnea and 30-day risk of cardiovascular complications after major noncardiac surgery. Design, Setting, and Participants: Prospective cohort study involving adult at-risk patients without prior diagnosis of sleep apnea and undergoing major noncardiac surgery from 8 hospitals in 5 countries between January 2012 and July 2017, with follow-up until August 2017. Postoperative monitoring included nocturnal pulse oximetry and measurement of cardiac troponin concentrations. Exposures: Obstructive sleep apnea was classified as mild (respiratory event index [REI] 5-14.9 events/h), moderate (REI 15-30), and severe (REI >30), based on preoperative portable sleep monitoring. Main Outcomes and Measures: The primary outcome was a composite of myocardial injury, cardiac death, heart failure, thromboembolism, atrial fibrillation, and stroke within 30 days of surgery. Proportional-hazards analysis was used to determine the association between obstructive sleep apnea and postoperative cardiovascular complications. Results: Among a total of 1364 patients recruited for the study, 1218 patients (mean age, 67 [SD, 9] years; 40.2% women) were included in the analyses. At 30 days after surgery, rates of the primary outcome were 30.1% (41/136) for patients with severe OSA, 22.1% (52/235) for patients with moderate OSA, 19.0% (86/452) for patients with mild OSA, and 14.2% (56/395) for patients with no OSA. OSA was associated with higher risk for the primary outcome (adjusted hazard ratio [HR], 1.49 [95% CI, 1.19-2.01]; P = .01); however, the association was significant only among patients with severe OSA (adjusted HR, 2.23 [95% CI, 1.49-3.34]; P = .001) and not among those with moderate OSA (adjusted HR, 1.47 [95% CI, 0.98-2.09]; P = .07) or mild OSA (adjusted HR, 1.36 [95% CI, 0.97-1.91]; P = .08) (P = .01 for interaction). The mean cumulative duration of oxyhemoglobin desaturation less than 80% during the first 3 postoperative nights in patients with cardiovascular complications (23.1 [95% CI, 15.5-27.7] minutes) was longer than in those without (10.2 [95% CI, 7.8-10.9] minutes) (P < .001). No significant interaction effects on perioperative outcomes were observed with type of anesthesia, use of postoperative opioids, and supplemental oxygen therapy. Conclusions and Relevance: Among at-risk adults undergoing major noncardiac surgery, unrecognized severe obstructive sleep apnea was significantly associated with increased risk of 30-day postoperative cardiovascular complications. Further research would be needed to assess whether interventions can modify this risk.


Assuntos
Doenças Cardiovasculares/etiologia , Complicações Pós-Operatórias/etiologia , Apneia Obstrutiva do Sono/complicações , Procedimentos Cirúrgicos Operatórios/efeitos adversos , Idoso , Doenças Cardiovasculares/mortalidade , Feminino , Humanos , Hipóxia/complicações , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Polissonografia , Complicações Pós-Operatórias/mortalidade , Estudos Prospectivos , Fatores de Risco , Apneia Obstrutiva do Sono/diagnóstico
8.
Acad Med ; 90(10): 1340-6, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26222322

RESUMO

The service line (SL) model has been proven to help shift health care toward value-based services, which is characterized by coordinated, multidisciplinary, high-quality, and cost-effective care. However, academic medical centers struggle with how to effectively set up SL structures that overcome the organizational and cultural challenges associated with simultaneously delivering the highest-value care for the patient and advancing the academic mission. In this article, the authors examine the evolution of UMass Memorial Health Care's heart and vascular service line (HVSL) from 2006 to 2011 and describe the impact on its success of multiple strategic decisions. These include key academic physician leadership recruitments and engagement via a matrixed governance and management model; development of multidisciplinary teams; empowerment of SL leadership through direct accountability and authority over programs and budgets; joint educational and training programs; incentives for academic achievement; and co-localization of faculty, personnel, and facilities. The authors also explore the barriers to success, including the need to overcome historical departmental-based silos, cultural and training differences among disciplines, confusion engendered by a matrixed reporting structure, and faculty's unfamiliarity with the financial and organizational skills required to operate a successful SL. Also described here is the impact that successful implementation of the SL has on creating high-quality services, increased profitability, and contribution to the financial stability and academic achievement of the academic medical center.


Assuntos
Centros Médicos Acadêmicos/organização & administração , Cardiologia/organização & administração , Administração de Serviços de Saúde , Serviços de Saúde/economia , Qualidade da Assistência à Saúde , Cirurgia Torácica/organização & administração , Centros Médicos Acadêmicos/economia , Centros Médicos Acadêmicos/normas , Cardiologia/economia , Cardiologia/normas , Procedimentos Cirúrgicos Cardiovasculares , Análise Custo-Benefício , Serviços de Saúde/normas , Humanos , Massachusetts , Cirurgia Torácica/economia , Cirurgia Torácica/normas
9.
Heart Rhythm ; 12(1): 3-10, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25257092

RESUMO

BACKGROUND: MicroRNAs (miRNAs) are associated with cardiovascular disease and control gene expression and are detectable in the circulation. OBJECTIVE: The purpose of this study was to test the hypothesis that circulating miRNAs may be associated with atrial fibrillation (AF). METHODS: Using a prospective study design powered to detect subtle differences in miRNAs, we quantified plasma expression of 86 miRNAs by high-throughput quantitative reverse transcriptase-polymerase chain reaction in 112 participants with AF and 99 without AF. To examine parallels between cardiac and plasma miRNA profiles, we quantified atrial tissue and plasma miRNA expression using quantitative reverse transcriptase-polymerase chain reaction in 31 participants undergoing surgery. We also explored the hypothesis that lower AF burden after ablation would be reflected in the circulating blood pool by examining change in plasma miRNAs after AF ablation (n = 47). RESULTS: Mean age of the cohort was 59 years; 58% of participants were men. Plasma miRs-21 and 150 were 2-fold lower in participants with AF than in those without AF after adjustment (P ≤.0006). Plasma levels of miRs-21 and 150 also were lower in participants with paroxysmal AF than in those with persistent AF (P <.05). Expression of miR-21, but not of miR-150, was lower in atrial tissue from patients with AF than in those without AF (P <.05). Plasma levels of miRs-21 and 150 increased 3-fold after AF ablation (P ≤.0006). CONCLUSION: Cardiac miRs-21 and 150 are known to regulate genes implicated in atrial remodeling. Our findings show associations between plasma miRs-21 and 150 and AF, suggesting that circulating miRNAs can provide insights into cardiac gene regulation.


Assuntos
Fibrilação Atrial/sangue , Fibrilação Atrial/cirurgia , Ablação por Cateter , MicroRNAs/sangue , Adulto , Idoso , Fibrilação Atrial/etiologia , Estudos de Casos e Controles , Estudos de Coortes , Feminino , Regulação da Expressão Gênica , Átrios do Coração/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
10.
BMJ Open ; 4(1): e004097, 2014 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-24413351

RESUMO

INTRODUCTION: Emerging epidemiological data suggest that obstructive sleep apnoea (OSA) is common in the general surgical population. Unfortunately, the majority of these patients are unrecognised and untreated at the time of surgery. There is substantial biological rationale to indicate that patients with unrecognised OSA are at a higher risk of postoperative vascular events. However, the extent of this morbidity is currently unknown. We have initated the postoperative vascular complications in the unrecognised obstructive sleep apnoea (POSA) study to determine the associations between OSA, nocturnal hypoxia and major postoperative vascular events in 1200 moderate-to-high risk patients undergoing major non-cardiac surgery. METHODS AND ANALYSIS: The POSA study is an international prospective observational cohort study. Using a type 3 portable sleep monitoring device and ambulatory oximetry, we will quantify the severity of OSA. The primary outcome is a composite of vascular death, myocardial infarction; non-fatal cardiac arrest; stroke; pulmonary embolism; congestive heart failure and new arrhythmia within 30 days of surgery. As of November 2013, we have recruited over 700 patients from nine centres in six countries. The mean age is 68 years, the mean body mass index is 27 kg/m(2) and 55% of patients are men. 27.9% of patients have known coronary artery disease, over 76% have diabetes. The majority of patients underwent orthopaedic surgery (28%) and colorectal resection (18.5%). ETHICS AND DISSEMINATION: The POSA study has received ethics approval from all study sites before patient recruitment. Informed consent will be obtained from all patients. The POSA study will determine the risk of unrecognised OSA in major non-cardiac surgery. We will publish these findings in peer-reviewed journals. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01494181.


Assuntos
Complicações Pós-Operatórias/etiologia , Apneia Obstrutiva do Sono/complicações , Procedimentos Cirúrgicos Operatórios , Doenças Vasculares/etiologia , Idoso , Estudos de Coortes , Feminino , Humanos , Masculino , Projetos de Pesquisa , Medição de Risco
11.
Ann Thorac Surg ; 89(1): 283-5, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20103258

RESUMO

Partial anomalous pulmonary venous connection with infradiaphragmatic drainage into the inferior vena cava (scimitar syndrome) constitutes a rare diagnosis in adults. Diagnosis is suggested by plain chest roentgenogram and confirmed by computed tomography angiography or magnetic resonance imaging. Reported operations for scimitar syndrome are complex, often requiring circulatory arrest. Reoperation for pulmonary vein stenosis is a troubling complication. We report an effective simplified operation for use in adults.


Assuntos
Veias Pulmonares/anormalidades , Malformações Vasculares/diagnóstico , Procedimentos Cirúrgicos Vasculares/métodos , Adulto , Seguimentos , Humanos , Angiografia por Ressonância Magnética , Masculino , Radiografia Torácica , Malformações Vasculares/cirurgia
12.
Neurochem Res ; 28(9): 1359-67, 2003 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12938858

RESUMO

Experimental infection of BALB/c mice with the gram-positive bacterium Nocardia asteroides produces marked loss of nigrostriatal dopamine neurons, resulting in striatal dopamine depletion. To investigate the mechanism(s) responsible for this neuronal loss, we evaluated the influence of N. asteroides cell-free culture filtrates on rat pheochromocytoma PC12 cells, an in vitro model for dopamine neurons. Changes in cell viability and cell numbers were minimal after 24 h, but increased with longer incubation. In contrast, dopamine depletion occurred after 30 min incubation, and was greater with GUH-2 filtrate than with filtrate from the less virulent strain 10905. Incubation with the culture filtrate decreased viability in neuroblastoma and glioma cell lines, indicating that cytotoxic effects were not limited to dopaminergic cells. These findings suggest that the loss of nigrostriatal dopamine neurons and concomitant striatal dopamine depletion in Nocardia-infected mice may be due, at least in part, to the neurotoxicity of nocardial secretory products.


Assuntos
Fatores Biológicos/toxicidade , Dopamina/metabolismo , Neurônios/efeitos dos fármacos , Neurotoxinas/toxicidade , Nocardia asteroides/metabolismo , Animais , Fatores Biológicos/metabolismo , Catecolaminas/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Meios de Cultura , Filtração , Neuroglia/citologia , Neuroglia/efeitos dos fármacos , Neurônios/citologia , Neurônios/metabolismo , Neurotoxinas/metabolismo , Nocardia asteroides/isolamento & purificação , Células PC12 , Ratos , Fatores de Tempo
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