Dual-energy CT: Technical considerations and clinical applications.

Although dual-energy CT was initially described by Hounsfield in 1973, it remains underused in clinical practice. It is therefore important to emphasize the clinical benefits and limitations of this technique. Iodine mapping makes it possible to quantify the uptake of iodine, which is very important in characterizing tumors, lung perfusion, pulmonary nodules, and the tumor response to new treatments. Dual-energy CT also makes it possible to obtain virtual single-energy images and virtual images without iodinated contrast or without calcium, as well as to separate materials such as uric acid or fat and to elaborate hepatic iron overload maps. In this article, we review some of the clinical benefits and technical limitations to improve understanding of dual-energy CT and expand its use in clinical practice.

The second Mexican consensus on hepatocellular carcinoma. Part II: Treatment.

Hepatocellular carcinoma (HCC) is more frequently manifesting as one of the main complications of cirrhosis of the liver, its principal risk factor. There have been modifications in its incidence over the past decade, related to an epidemiologic transition in the etiology of cirrhosis, with a decrease in the prevalence of hepatitis C and an increase in nonalcoholic fatty liver disease (NAFLD) as a cause, as well as the development of HCC in the non-cirrhotic liver due to NAFLD. Genetic markers associated with the disease have been identified, and surveillance and diagnosis have improved. Regarding treatment, surgical techniques, in both resection and transplantation, have advanced and radiologic techniques, at the curative stage of the disease, have enhanced survival in those patients. And finally, there have been radical changes in the systemic approach, with much more optimistic expectations, when compared with the options available a decade ago. Therefore, the Asociación Mexicana de Hepatología decided to carry out the Second Mexican Consensus on Hepatocellular Carcinoma, which is an updated review of the available national and international evidence on the epidemiology, risk factors, surveillance, diagnosis, and treatment of the disease, to offer the Mexican physician current information on the different topics regarding hepatocellular carcinoma. In this second part of the document, the topics related to the treatment of HCC are presented.

The second Mexican consensus on hepatocellular carcinoma. Part I: Epidemiology and diagnosis.

Hepatocellular carcinoma (HCC) is more frequently manifesting as one of the main complications of cirrhosis of the liver, its principal risk factor. There have been modifications in its incidence over the past decade, related to an epidemiologic transition in the etiology of cirrhosis, with a decrease in the prevalence of hepatitis C and an increase in nonalcoholic fatty liver disease (NAFLD) as a cause, as well as the development of HCC in the non-cirrhotic liver due to NAFLD. Genetic markers associated with the disease have been identified, and surveillance and diagnosis have improved. Regarding treatment, surgical techniques, in both resection and transplantation, have advanced and radiologic techniques, at the curative stage of the disease, have enhanced survival in those patients. And finally, there have been radical changes in the systemic approach, with much more optimistic expectations, when compared with the options available a decade ago. Therefore, the Asociación Mexicana de Hepatología decided to carry out the Second Mexican Consensus on Hepatocellular Carcinoma, which is an updated review of the available national and international evidence on the epidemiology, risk factors, surveillance, diagnosis, and treatment of the disease, to offer the Mexican physician current information on the different topics regarding hepatocellular carcinoma. In this first part of the document, the topics related to epidemiology and diagnosis are presented.

Anaesthetic-surgical guide in the treatment of ascending aorta and surgery of the ascending aorta and aortic arch. Consensus document of the Spanish Society of Cardiovascular and Endovascular Surgery and the Sociedad of Anaesthesiology, Resuscitation and Pain Therapy.

Aortic pathology is always a challenge for the clinician, and must be diagnosed and treated by a multidisciplinary team due to the technical and technological complexity of the resources used. Ongoing efforts to implement a systematic, protocolized approach involving "Aortic teams" made up of cardiologists, cardiac surgeons, vascular surgeons, anaesthesiologists and radiologists, among others are now leading to improved outcomes. The aim of this consensus document drawn up by the Aortic working groups of the Spanish Society of Anaesthesiology, Resuscitation and Pain Therapy (SEDAR) and the Spanish Society of Thoracic and Cardiovascular Surgery (SECTCV) is to disseminate a set of working protocols. The latest consensus document of the European Association for Cardio-Thoracic Surgery (EACTS) and the European Society for Vascular Surgery (ESVS) define the concept of "AORTIC TEAM"(1). The aortic team should be closely involved from diagnosis to treatment and finally follow-up, and should be formed of cardiac and vascular surgeons working together with anaesthesiologists, cardiologists, radiologists and geneticists. Treatment of aortic pathologies should be centralised in large centres, because this is the only way to effectively understand the natural course of the disease, provide the entire range of treatment options under one umbrella and treat potential complications. A streamlined emergent care pathway (24/7 availability), adequate transportation and transfer capabilities, as well as rapid activation of the multidisciplinary team must be available. In light of the complexity and constant evolution of therapeutic options, we present this first version of the Anaesthesiology and surgical guidelines for surgery of the ascending aorta and aortic arch. Some questions will no doubt remain unanswered, and future versions will include new techniques that, though implemented in some centres, are still not widely recommended.

Effectiveness and patient satisfaction with office hysteroscopic polypectomy in patients with symptomatic endometrial polyps.

Background: Endometrial polyps are a common cause of abnormal uterine bleeding. In-office hysteroscopic management is frequently performed to treat this frequently encountered pathology. Objectives: To evaluate the long-term outcome and patients' satisfaction with office hysteroscopic polypectomy in patients with symptomatic endometrial polyps. Materials and Methods: Retrospective longitudinal observational study of all hysteroscopic polypectomies performed at d'Igualada University Hospital (Barcelona, Spain) between May 2016 and December 2018. The medical records were reviewed, and a telephone interview was conducted with all the patients diagnosed with symptomatic endometrial polyps who underwent outpatient hysteroscopic polypectomy, with the purpose of evaluating the post-procedure symptomatology and satisfaction with the procedure. Main outcomes and results: A total of 848 outpatient hysteroscopies were performed, 379 of which were polypectomies. Of those, 163 procedures were performed in symptomatic patients and were included in the final analysis. The most common symptom among premenopausal patients was abnormal uterine bleeding (84.85%) and in postmenopausal women, postmenopausal bleeding (95.3%). After the procedure, the symptoms resolved or decreased considerably in 66.7% of premenopausal and 93.7% of postmenopausal patients. Additionally, 87.1% of the patients were very satisfied with the procedure. Conclusion: Office hysteroscopic polypectomy is an effective treatment for endometrial polyps with high patient satisfaction reported following the procedure.

First insight into plastics ingestion by fish in the Gulf of California, Mexico.

Plastic particle occurrence in the digestive tracts of fishes from a tropical estuarine system in the Gulf of California was investigated. A total of 1095 fish were analysed, representing 15 species. In total 1384 particles of plastic debris were recovered from the gastrointestinal tracts of 552 specimens belonging to 13 species, and all consisted of threads, the majority of which were small microplastics (0.23 to 1.89), followed by large microplastics (2.07 to 4.49), and few mesoplastics (5.4 to 19.86). Plastic particles were identified using ATR-FTIR spectroscopy. The mean frequency of occurrence of plastics in the gastrointestinal tracts of fishes from this system was 50.5%, which is higher than frequencies reported in similar systems in other areas. The polymers identified by ATR-FTIR were polyamide (51.2%), polyethylene (36.6%), polypropylene (7.3%), and polyacrylic (4.9%). These results show the first evidence of plastic contamination for estuarine biota in the Gulf of California.

Anaesthetic-surgical guide in the treatment of ascending aorta and surgery of the ascending aorta and aortic arch. Consensus document of the Spanish Society of Cardiovascular and Endovascular Surgery and the Sociedad of Anaesthesiology, Resuscitation and Pain Therapy. / Guía anestésico-quirúrgica en el tratamiento de la cirugía de aorta ascendente y del arco aórtico. Documento de consenso de la Sociedad Española de Cirugía Cardiovascular y Endovascular y la Sociedad Española de Anestesiología, Reanimación y Terapeútica del Dolor.

Aortic pathology is always a challenge for the clinician, and must be diagnosed and treated by a multidisciplinary team due to the technical and technological complexity of the resources used. Ongoing efforts to implement a systematic, protocolized approach involving "Aortic teams" made up of cardiologists, cardiac surgeons, vascular surgeons, anaesthesiologists and radiologists, among others are now leading to improved outcomes. The aim of this consensus document drawn up by the Aortic working groups of the Spanish Society of Anaesthesiology, Resuscitation and Pain Therapy (SEDAR) and the Spanish Society of Thoracic and Cardiovascular Surgery (SECTCV) is to disseminate a set of working protocols. The latest consensus document of the European Association for Cardio-Thoracic Surgery (EACTS) and the European Society for Vascular Surgery (ESVS) define the concept of "AORTIC TEAM"(1). The aortic team should be closely involved from diagnosis to treatment and finally follow-up, and should be formed of cardiac and vascular surgeons working together with anaesthesiologists, cardiologists, radiologists and geneticists. Treatment of aortic pathologies should be centralised in large centres, because this is the only way to effectively understand the natural course of the disease, provide the entire range of treatment options under one umbrella and treat potential complications. A streamlined emergent care pathway (24/7 availability), adequate transportation and transfer capabilities, as well as rapid activation of the multidisciplinary team must be available. In light of the complexity and constant evolution of therapeutic options, we present this first version of the Anaesthesiology and surgical guidelines for surgery of the ascending aorta and aortic arch. Some questions will no doubt remain unanswered, and future versions will include new techniques that, though implemented in some centres, are still not widely recommended.

RETRACTED: Anesthesic and surgical guideline for the treatment of the thoraco-abdominal aorta. Consensus Document of the Spanish Societies of Anesthesia and Cardiovascular Surgery. / Guía anestésico-quirúrgica en el tratamiento de la patología de aorta toracoabdominal. Documento de Consenso de la Sociedad Española de Cirugía Cardiovascular Endovascular y la Sociedad Española de Anestesiología, Reanimación y Terapeútica del Dolor.

Este artículo ha sido retirado por indicación del Editor Jefe de la revista, después de constatar que parte de su contenido había sido plagiado, sin mencionar la fuente original: European Heart Journal (2014) 35, 2873 926.: https://academic.oup.com/eurheartj/article/35/41/2873/407693#89325738 El autor de correspondencia ha sido informado de la decisión y está de acuerdo con la retirada del artículo. El Comité Editorial lamenta las molestias que esta decisión pueda ocasionar. Puede consultar la política de Elsevier sobre la retirada de artículos en https://www.elsevier.com/about/our-business/policies/article-withdrawal

The use of one-piece U-shaped mesh and barbed sutures in laparoscopic sacrocolpopexy. / Empleo de malla en U de una pieza y sutura barbada durante la colposacropexia laparoscópica.

INTRODUCTION: Laparoscopic sacrocolpopexy (LS) is considered a safe and effective surgery for the treatment of pelvic organ prolapse (POP), but it requires expertise in laparoscopic surgery. The complexity of the intervention is due to the requirements of intracorporeal sutures and the manipulation of the mesh inside the cavity, which may be cumbersome. The barbed sutures (BS) simplify intracorporeal suturing and do not require knotting. Additionally, one-piece U-mesh (OP-UM) may facilitate handling, stabilization and tension adjustment. We describe our LS surgical technique using both materials to assess its feasibility, safety and effectiveness in a prospective series of patients. MATERIALS AND METHODS: A total of 7 patients with symptomatic pelvic organ prolapse were included. Urogynecological history, classification of the pelvic organ prolapse according to Baden-Walker and the application of the Prolapse Quality of Life questionnaire were performed in all cases. The non-absorbable polypropylene OP-UM (Uplift ™) was used. The posterior side of the single sling is sutured to the elevator anus muscles with two non-absorbable stitches. Two strands of BS (V-Loc™), tied at their ends, were used to attach the mesh to the vagina in two lines of continuous sutures in opposite directions. Self-anchoring tackers were used for promontofixation and BS for peritoneal closure. RESULTS: The median age was 60 years, the median time of the anterior branch mesh BS fixation was 23minutes (range 21,30 - 26,40min), intraoperative bleeding was minimal, and the median hospital stay was 3 days. No intraoperative complications were recorded, and no mesh erosions or recurrences were observed at a median follow-up of 14 months (range 3-25 months). All patients presented clinical improvement of the prolapse and were satisfied with surgery. We observed that the OP-UM self-stabilizes when it extends longitudinally into the abdominal cavity, reducing the need of the surgical assistant. The independent promontofixation of each part of the mesh (posterior and anterior) allows a more anatomical tension adjustment. Fixing the mesh to the vagina is fast and simple with our BS technique. CONCLUSIONS: The use of OP-UM and BS during LS is feasible, safe, effective and could simplify this surgical technique.

The Mexican consensus on non-cardiac chest pain. / Consenso mexicano sobre dolor torácico no cardiaco.

INTRODUCTION: Non-cardiac chest pain is defined as a clinical syndrome characterized by retrosternal pain similar to that of angina pectoris, but of non-cardiac origin and produced by esophageal, musculoskeletal, pulmonary, or psychiatric diseases. AIM: To present a consensus review based on evidence regarding the definition, epidemiology, pathophysiology, and diagnosis of non-cardiac chest pain, as well as the therapeutic options for those patients. METHODS: Three general coordinators carried out a literature review of all articles published in English and Spanish on the theme and formulated 38 initial statements, dividing them into 3 main categories: (i)definitions, epidemiology, and pathophysiology; (ii)diagnosis, and (iii)treatment. The statements underwent 3rounds of voting, utilizing the Delphi system. The final statements were those that reached >75% agreement, and they were rated utilizing the GRADE system. RESULTS AND CONCLUSIONS: The final consensus included 29 statements. All patients presenting with chest pain should initially be evaluated by a cardiologist. The most common cause of non-cardiac chest pain is gastroesophageal reflux disease. If there are no alarm symptoms, the initial approach should be a therapeutic trial with a proton pump inhibitor for 2-4weeks. If dysphagia or alarm symptoms are present, endoscopy is recommended. High-resolution manometry is the best method for ruling out spastic motor disorders and achalasia and pH monitoring aids in demonstrating abnormal esophageal acid exposure. Treatment should be directed at the pathophysiologic mechanism. It can include proton pump inhibitors, neuromodulators and/or smooth muscle relaxants, psychologic intervention and/or cognitive therapy, and occasionally surgery or endoscopic therapy.

Organochlorine pesticides air monitoring near a historical lindane production site in Spain.

The landfilling and dumping of persistent organic pollutants (POPs) and other persistent hazardous chemicals, such as hexachlorocyclohexane (HCH) isomers can have significantly adverse environmental consequences and cause contamination in soil, water, and atmosphere systems. Approximately 115,000 t of HCH wastes were generated by INQUINOSA Factory located in Sabiñánigo (Aragón, Spain) from 1975 to 1992, and were mainly dumped at Bailín and Sardas landfills. Under the frame of the project plan approved by the Government of Aragón, remediation and containment measures were implemented at the derelict production facility and landfill sites. To protect and assess the local environment, the concentrations of HCH isomers, pentachlorobenzene (PeCB) and hexachlorobenzene (HCB) in air were periodically monitored in the Sardas landfills and surroundings by passive sampling devices. The influence of meteorological parameters was evaluated, showing positive correlations between temperature and HCH and HCB concentrations. The highest HCH levels were detected in Sardas landfill and INQUINOSA Factory sites. PeCB values were statistically higher in Sardas landfill than in Sabiñánigo urban core, nevertheless, HCB concentrations were similar in both sampling points. Statistically positive correlations were found among HCH isomers in all sampling points, showing a major common source. The chlorobenzenes also correlated positively with each other. The α-/γ-HCH ratios were calculated (1.46 ±â€¯1.25; mean ±â€¯S.D.), corroborating that concentrations detected were mainly originated from the historical production, storage and waste disposal of technical HCH.

Peroral endoscopic myotomy for the treatment of achalasia and other esophageal motor disorders: Short-term and medium-term results at a Mexican tertiary care center. / Miotomía endoscópica peroral para el tratamiento de acalasia y otros trastornos motores del esófago. Resultados a corto y mediano plazo en un centro de referencia en México.

INTRODUCTION AND AIMS: Achalasia is characterized by the absence of lower esophageal sphincter relaxation and esophageal aperistalsis. Diagnosis is confirmed through high-resolution esophageal manometry. Laparoscopic myotomy is the standard treatment, but peroral endoscopic myotomy (POEM) is a safe and effective alternative, with good short-term and medium-term results. Our aim was to describe the short-term and medium-term experience with POEM at a tertiary care center. MATERIALS AND METHODS: The study was conducted within the time frame of November 2014 and February 2017. Treatment-naïve achalasia patients and previously-treated achalasia patients that were candidates for POEM were included. A protocolized 24-month follow-up was carried out. RESULTS: Fifty procedures were included and 31 (68%) were performed on women. Forty-one (82%) of the procedures were carried out on previously untreated patients, 7 (14%) were performed on previously treated patients, and 2 (4%) of the patients had redo-POEM. The mean age of the patients was 48.8±14.1 years. The pre-POEM Eckardt score was 9 and the integrated relaxation pressure was 24.4mmHg. Sixty-eight percent of the patients had type ii achalasia. Procedure time was 80min and myotomy length was 12.6cm. Hospital stay was 3 days and subcutaneous emphysema was the most common adverse event (30%). A total of 22/50 (44%) patients reached the 24-month follow-up, maintaining the Eckardt score and the decrease in the integrated relaxation pressure. There were no deaths. A total of 47.5% of the patients had a positive pH-study at 6 months, 15% had clinical reflux, and 35% presented with mild esophagitis. All the patients were adequately controlled with proton pump inhibitors. CONCLUSION: POEM is safe and effective in the short term and medium term for the treatment of achalasia and other esophageal motor disorders in Mexican patients.

Study of the possible link of 25-hydroxyvitamin D with Epstein-Barr virus and human herpesvirus 6 in patients with multiple sclerosis.

BACKGROUND AND PURPOSE: Although the causes of multiple sclerosis (MS) remain partially unknown, environmental and genetic factors are thought to play a role in its aetiopathogenesis. Hypovitaminosis D, Epstein-Barr virus (EBV) and human herpesvirus 6 (HHV-6) infections have been described as possible MS triggers. Our aim was to analyse the possible link between 25-hydroxyvitamin D [25(OH)D] and viruses in patients with MS. METHODS: We included 482 patients with MS in a 2-year study. Serum samples were collected to analyse 25(OH)D levels and, according to sample availability, antibody titres against EBV and HHV-6 by enzyme-linked immunosorbent assay. DNA was extracted from blood in order to analyse EBV and HHV-6 viral load by quantitative real-time polymerase chain reaction and to genotype MS-related single nucleotide polymorphisms (rs3135388, rs2248359 and rs12368653) when possible. RESULTS: The 25(OH)D levels were significantly higher in the first semester of the year than in the second. Carriers of the risk allele rs2248359-C showed lower 25(OH)D levels than non-carriers. For EBV, viral load was significantly higher when 25(OH)D levels were low, demonstrating an inverse correlation between 25(OH)D levels and EBV load. CONCLUSIONS: The 25(OH)D levels could be involved in the regulation of EBV replication/reactivation in patients with MS.

Traditional and novel halogenated flame retardants in urban ambient air: Gas-particle partitioning, size distribution and health implications.

Urban ambient air samples, including gas-phase (PUF), total suspended particulates (TSP), PM10, PM2.5 and PM1 airborne particle fractions were collected to evaluate gas-particle partitioning and size particle distribution of traditional and novel halogenated flame retardants. Simultaneously, passive air samplers (PAS) were deployed in the same location. Analytes included 33 polybrominated diphenyl ether (PBDE), 2,2',4,4',5,5'-hexabromobiphenyl (BB-153), hexabromobenzene (HBB), pentabromoethylbenzene (PBEB), 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE), decabromodiphenyl ethane (DBDPE), dechloranes (Dec 602, 603, 604, 605 or Dechorane plus (DP)) and chlordane plus (CP). Clausius-Clapeyron equation, gas-particle partition coefficient (Kp), fraction partitioned onto particles (φ) and human respiratory risk assessment were used to evaluate local or long-distance transport sources, gas-particle partitioning sorption mechanisms, and implications for health, respectively. PBDEs were the FR with the highest levels (13.9pgm-3, median TSP+PUF), followed by DP (1.56pgm-3), mirex (0.78pgm-3), PBEB (0.05pgm-3), and BB-153 (0.04pgm-3). PBDE congener pattern in particulate matter was dominated by BDE-209, while the contribution of more volatile congeners, BDE-28, -47, -99, and -100 was higher in gas-phase. Congener contribution increases with particle size and bromination degree, being BDE-47 mostly bounded to particles≤PM1, BDE-99 to > PM1 and BDE-209 to > PM2.5. No significant differences were found for PBDE and DP concentrations obtained with passive and active samplers, demonstrating the ability of the formers to collect particulate material. Deposition efficiencies and fluxes on inhaled PBDEs and DP in human respiratory tract were calculated. Contribution in respiratory track was dominated by head airway (2.16 and 0.26pgh-1, for PBDE and DP), followed by tracheobronchial (0.12 and 0.02pgh-1) and alveoli (0.01-0.002pgh-1) regions. Finally, hazard quotient values on inhalation were proposed (6.3×10-7 and 1.1×10-8 for PBDEs and DP), reflecting a low cancer risk through inhalation.

Gas/particle partitioning and particle size distribution of PCDD/Fs and PCBs in urban ambient air.

Urban ambient air samples, including gas-phase (PUF), total suspended particulates (TSP), PM10, PM2.5 and PM1 airborne particle fractions were collected to evaluate gas-particle partitioning and size particle distribution of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs). Clausius-Clapeyron equation, regressions of logKp vs logPL and logKOA, and human respiratory risk assessment were used to evaluate local or long-distance transport sources, gas-particle partitioning sorption mechanisms, and implications for health. Total ambient air levels (gas phase+particulate phase) of TPCBs and TPCDD/Fs, were 437 and 0.07pgm-3 (median), respectively. Levels of PCDD/F in the gas phase (0.004-0.14pgm-3, range) were significantly (p<0.05) lower than those found in the particulate phase (0.02-0.34pgm-3). The concentrations of PCDD/Fs were higher in winter. In contrast, PCBs were mainly associated to the gas phase, and displayed maximum levels in warm seasons, probably due to an increase in evaporation rates, supported by significant and strong positive dependence on temperature observed for several congeners. No significant differences in PCDD/Fs and PCBs concentrations were detected between the different particle size fractions considered (TSP, PM10, PM2.5 and PM1), reflecting that these chemicals are mainly bounded to PM1. The toxic content of samples was also evaluated. Total toxicity (PUF+TSP) attributable to dl-PCBs (13.4fg-TEQ05 m-3, median) was higher than those reported for PCDD/Fs (6.26fg-TEQ05 m-3). The inhalation risk assessment concluded that the inhalation of PCDD/Fs and dl-PCBs pose a low cancer risk in the studied area.

Inflammatory Bowel Disease: Joint Management in Gastroenterology and Dermatology. / Enfermedad inflamatoria intestinal: abordaje conjunto digestivo-dermatológico.

Inflammatory bowel disease (IBD) is a complex entity that includes Crohn disease and ulcerative colitis. It is characterized by a chronic proinflammatory state of varying intensity that often leads to considerable morbidity. In the last decade, several therapeutic targets have been identified that are susceptible to the use of biological agents, including anti-tumor necrosis factor alpha antibodies, which are associated with paradoxical psoriasiform reactions in 5% of patients. Decision-making in the management of these cases requires close collaboration between the dermatologist and gastroenterologist. Inflammatory bowel disease is also associated with various other dermatologic and rheumatologic manifestations, and presents a genetic and pathogenic association with psoriasis that justifies both the interdisciplinary approach to these patients and the present review.

Fipronil sulfone induced higher cytotoxicity than fipronil in SH-SY5Y cells: Protection by antioxidants.

Fipronil is a broad spectrum insecticide from the phenyl pyrazole family, which targets GABA receptor. Limited information is available about the metabolite fipronil sulfone cytotoxic actions. This study examined in vitro neurotoxicity of fipronil and fipronil sulfone and evaluated Trolox (vitamin E analog) (0.3, 1µM), N-acetyl-cysteine (0.5, 1mM), melatonin (0.1, 1µM) and Tempol (superoxide dismutase analog) (0.3, 0.5mM) protective role in SH-SY5Y cells. MTT and LDH assays were carried out to assess the cytotoxicity of fipronil and fipronil sulfone at 3-100µM concentrations. Fipronil sulfone was more toxic than fipronil. Tempol showed the best neuroprotectant profile against fipronil (50 and 150µM) and fipronil sulfone (3 and 10µM) reaching control levels. Fipronil (100µM) and fipronil sulfone (3µM) treatments induced a 4.7- and 5-fold increases in lipid peroxides measured as malondialdehyde (MDA) and a 2.2- and 2.0-fold increases in the levels of nitric oxide (NO). These results suggest that oxidative stress observed may be one of the major mechanisms of fipronil-induced neurotoxicity and it may be attributed in part to fipronil disposition and metabolism. Our results led us postulate that metabolite fipronil sulfone might be responsible for the fipronil-induced toxicity rather than fipronil itself.