Accidental ingestion of methyl ethyl ketone peroxide: N-acetylcysteine treatment and toxicological analysis.

INTRODUCTION: Methyl ethyl ketone peroxide (MEKP) is a highly toxic product which promotes tissue damage by uncontrolled free radical production. CASE REPORT: A man accidentally ingested 110 ml of MEKP (37%) at his workplace after mistaking it with a bottle of water. A loading dose of N-acetylcysteine (NAC) and subsequent maintenance doses were applied at the hospital for three consecutive days. Biochemical and hematological parameters showed significant alterations. Tracheal intubation, gastric lavage and hemodialysis were not performed. Methyl ethyl ketone (MEK) and MEKP were detected in EDTA-blood samples by GC-FID and LC-QTOF/MS respectively. An endoscopy exam identified tissue damage. The patient was admitted to the hospital for 10 days. No sequelae were reported after the MEKP poisoning. Oral administration of NAC was successful as an antidote without another approach. CONCLUSIONS: Although NAC treatment was successful, supervision after the hospitalization period was required according to the prognosis. Workplace conditions promoted anosmia, explaining the accident. MEKP and MEK were successfully detected in blood samples even with less-than-ideal storage conditions. Knowledge of MEKP dangerousness and good work practices can prevent accidental MEKP poisoning.

Baixa prevalência de esôfago de Barrett em área de risco para câncer esofágico no Sul do Brasil / Low prevalence of barrett's esophagus in a risk area for esophageal cancer in south of brazil

ABSTRACT BACKGROUND: Barrett's esophagus a complication of gastroesophageal reflux disease (GERD) is a precursor of esophageal adenocarcinoma. The incidence of esophageal adenocarcinoma has been increasing in most Western countries. Rio Grande do Sul (RS), the Southernmost state of Brazil has the highest rates of esophageal cancer with low prevalence of esophageal adenocarcinoma. OBJECTIVE: To investigate the prevalence of Barrett's esophagus among patients underwent to upper gastrointestinal endoscopy in the last 5 years. METHODS: The records of patients underwent upper gastrointestinal endoscopy between 2011 and 2015 were analyzed. Demographic data, GERD symptoms, endoscopic findings, extension and histological diagnosis of columnar epithelia of the esophagus were recorded. Significance among the variables was accessed by chi-square test and Fisher's exact test with 95% CI. RESULTS: A total of 5996 patients underwent to upper gastrointestinal endoscopy in the period were included. A total of 1769 (30%) patients with GERD symptoms or esophagitis and 107 (1.8%) with columnar lined esophagus were identified. Except for eight patients, the others with columnar lined esophagus had GERD symptoms or esophagitis. Barrett's esophagus defined by the presence of intestinal metaplasia occurred in 47 patients; 20 (43%) with segments over 3 cm and 27 (57%) with segments shorter than 3 cm. The global prevalence of Barrett's esophagus was 0.7% and in GERD patients 2.7%. The odds ratio for the occurrence of columnar lined esophagus in patients with GERD was 30 (95%CI=15.37-63.34). The odds ratio for the presence of intestinal metaplasia in long segments was 8 (95%CI=2.83-23.21). CONCLUSION: GERD patients had a risk 30-folds greater to present columnar lined esophagus than patients without GERD symptoms. Long segments of columnar lined esophagus, had a risk eight-folds higher to have Barrett's esophagus than short segments. Barrett's esophagus overall prevalence was 0.7%. In GERD patients, the prevalence was 2.7%. Long Barrett's esophagus represented globally 0.3% and 1.1% in GERD patients.

RESUMO CONTEXTO: Esôfago de Barrett, complicação da doença do refluxo gastroesofágico (DRGE), é lesão precursora do adenocarcinoma esofágico. O adenocarcinoma esofágico apresenta incidência crescente principalmente no ocidente. O estado do Rio Grande do Sul apresenta as taxas mais altas de câncer esofágico no Brasil, porém com baixa prevalência de adenocarcinoma. OBJETIVO: Investigar a prevalência de esôfago de Barrett em pacientes submetidos a endoscopia digestiva alta nos últimos 5 anos. MÉTODOS: Revisão de prontuários dos pacientes submetidos a endoscopia digestiva alta entre 2011 e 2015. Registrados dados demográficos, sintomas de DRGE, achados endoscópicos, extensão e diagnóstico histológico de epitelização colunar do esôfago. A significância entre as variáveis foi acessada pelos testes do qui-quadrado e exato de Fisher com IC95%. RESULTADOS: Foram incluídos 5996 pacientes. Identificamos 1769 (30%) com sintomas de DRGE ou esofagite e 107 (1,8%) com epitelização colunar. À exceção de oito pacientes com epitelização colunar, os demais apresentavam sintomas de DRGE ou esofagite. Esôfago de Barrett definido pela presença de metaplasia intestinal ocorreu em 47 pacientes; 20 (43%) com segmentos acima de 3 cm e em 27 (57%) com segmentos menores. A prevalência global de esôfago de Barrett foi 0,7% e em pacientes com DRGE foi 2,7%. A razão de chances para a ocorrência de epitelização colunar em pacientes com DRGE foi 30 (IC95%=15,37-63,34) e para a ocorrência de metaplasia intestinal em segmentos longos foi 8 (IC95%=2,83-23,21). CONCLUSÃO: Pacientes com DRGE apresentaram risco 30 vezes maior que pacientes sem DRGE para a ocorrência de epitelização colunar. O risco de ocorrência de esôfago de Barrett em segmentos longos foi oito vezes maior. A prevalência global de esôfago de Barrett foi 0,7%. Em pacientes com DRGE a prevalência foi 2,7%. Segmentos longos de esôfago de Barrett representaram globalmente 0,3% e em pacientes com DRGE 1,1%.

LOW PREVALENCE OF BARRETT'S ESOPHAGUS IN A RISK AREA FOR ESOPHAGEAL CANCER IN SOUTH OF BRAZIL.

BACKGROUND: Barrett's esophagus a complication of gastroesophageal reflux disease (GERD) is a precursor of esophageal adenocarcinoma. The incidence of esophageal adenocarcinoma has been increasing in most Western countries. Rio Grande do Sul (RS), the Southernmost state of Brazil has the highest rates of esophageal cancer with low prevalence of esophageal adenocarcinoma. OBJECTIVE: To investigate the prevalence of Barrett's esophagus among patients underwent to upper gastrointestinal endoscopy in the last 5 years. METHODS: The records of patients underwent upper gastrointestinal endoscopy between 2011 and 2015 were analyzed. Demographic data, GERD symptoms, endoscopic findings, extension and histological diagnosis of columnar epithelia of the esophagus were recorded. Significance among the variables was accessed by chi-square test and Fisher's exact test with 95% CI. RESULTS: A total of 5996 patients underwent to upper gastrointestinal endoscopy in the period were included. A total of 1769 (30%) patients with GERD symptoms or esophagitis and 107 (1.8%) with columnar lined esophagus were identified. Except for eight patients, the others with columnar lined esophagus had GERD symptoms or esophagitis. Barrett's esophagus defined by the presence of intestinal metaplasia occurred in 47 patients; 20 (43%) with segments over 3 cm and 27 (57%) with segments shorter than 3 cm. The global prevalence of Barrett's esophagus was 0.7% and in GERD patients 2.7%. The odds ratio for the occurrence of columnar lined esophagus in patients with GERD was 30 (95%CI=15.37-63.34). The odds ratio for the presence of intestinal metaplasia in long segments was 8 (95%CI=2.83-23.21). CONCLUSION: GERD patients had a risk 30-folds greater to present columnar lined esophagus than patients without GERD symptoms. Long segments of columnar lined esophagus, had a risk eight-folds higher to have Barrett's esophagus than short segments. Barrett's esophagus overall prevalence was 0.7%. In GERD patients, the prevalence was 2.7%. Long Barrett's esophagus represented globally 0.3% and 1.1% in GERD patients.

Is the immunocromatographic fecal antigen test effective for primary diagnosis of helicobacter pylori infection in dyspeptic patients? / Teste imunocromatográfico do antígeno fecal: efetivo no diagnóstico primário da infecção por Helicobacter pylori em pacientes dispépticos?

ABSTRACT Background The diagnosis of H. pylori infection can be performed by non-invasive and invasive methods.The identification through a fecal antigen test is a non-invasive, simple, and relatively inexpensive test. Objective To determine the diagnostic performance of fecal antigen test in the identification of H. pylori infection. Methods H. pylori antigens were identified in the stools of dyspeptic patients undergoing upper gastrointestinal endoscopy. For the identification of H. pylori antigen, we use ImmunoCard STAT! HpSA with immunochromatography technique. Histopathology plus urease test were the gold standard. Results We studied 163 patients, 51% male, mean age of 56.7± 8.5years. H. pylori infection was present in 49%. Fecal test presented: sensitivity 67.5% (CI95% 60.6-72.9); specificity 85.5% (CI95% 78.9-90.7); positive predictive value 81.8% (CI95% 73.4-88.4) and negative predictive value 73,2% (CI95% 67.5-77.6); Positive likelihood ratio was 4.7 (CI95% 2.9-7.9) and Negative Likelihood Ratio 0.4 (CI95% 0.3-0.5). The prevalence odds ratio for a positive test was 12.3 (CI95% 5.7-26.3).The index kappa between FAT and histology/urease test was 0.53 (CI95% 0.39-0.64). Conclusion Immunochromatographic FAT is less expensive than the other methods and readily accepted by the patients but its diagnostic performance does not recommend its use in the primary diagnosis, when the patient may have an active infection.

RESUMO Contexto O diagnóstico da infecção por Helicobacter pylori (H. pylori) pode ser realizado por métodos invasivos e não invasivos. A identificação através do teste do antígeno fecal é um método não invasivo, simples, fácil e relativamente barato. Objetivo Determinar o desempenho diagnóstico do teste fecal imunocromatográfico na identificação da infecção pelo H. pylori. Métodos A pesquisa de antígenos fecais do H. pylori foi realizada através do ImmunoCard STAT! HpSA em pacientes dispépticos submetidos à endoscopia digestiva alta com coleta de biópsias para histopatologia e teste da urease, utilizados como padrão ouro. Resultados Foram estudados 163 pacientes, 51% do sexo masculino, com idade média de 56,7± 8,5 anos. A infecção por H. pylori esteve presente em 49%. O teste fecal apresentou o seguinte desempenho diagnóstico: sensibilidade 67,5% (IC95% 60,6-72,9), especificidade 85,5% (IC95% 78,9-90,7), valor preditivo positivo 81,8% (IC95% 73,4-88,4) e valor preditivo negativo 73,2% (IC95% 67,5-77,6). A razão de probabilidade positiva foi 4,7 (IC95% 2,9-7,9) e a razão de probabilidade negativa foi 0,4 (IC95% 0,3-0,5). A razão de chances de prevalência para teste fecal positivo foi 12,3 (IC95% 5,7-26,3). O índice kappa para a concordância do teste fecal com histologia/teste da urease foi 0,53 (IC95% 0,39-0,64) Conclusão O teste fecal imunocromatográfico apresenta baixo custo e é facilmente aceito pelos pacientes, no entanto seu desempenho diagnóstico não o recomenda para diagnóstico primário.

IS THE IMMUNOCROMATOGRAPHIC FECAL ANTIGEN TEST EFFECTIVE FOR PRIMARY DIAGNOSIS OF HELICOBACTER PYLORI INFECTION IN DYSPEPTIC PATIENTS?

BACKGROUND: The diagnosis of H. pylori infection can be performed by non-invasive and invasive methods.The identification through a fecal antigen test is a non-invasive, simple, and relatively inexpensive test. OBJECTIVE: To determine the diagnostic performance of fecal antigen test in the identification of H. pylori infection. METHODS: H. pylori antigens were identified in the stools of dyspeptic patients undergoing upper gastrointestinal endoscopy. For the identification of H. pylori antigen, we use ImmunoCard STAT! HpSA with immunochromatography technique. Histopathology plus urease test were the gold standard. RESULTS: We studied 163 patients, 51% male, mean age of 56.7± 8.5years. H. pylori infection was present in 49%. Fecal test presented: sensitivity 67.5% (CI95% 60.6-72.9); specificity 85.5% (CI95% 78.9-90.7); positive predictive value 81.8% (CI95% 73.4-88.4) and negative predictive value 73,2% (CI95% 67.5-77.6); Positive likelihood ratio was 4.7 (CI95% 2.9-7.9) and Negative Likelihood Ratio 0.4 (CI95% 0.3-0.5). The prevalence odds ratio for a positive test was 12.3 (CI95% 5.7-26.3).The index kappa between FAT and histology/urease test was 0.53 (CI95% 0.39-0.64). CONCLUSION: Immunochromatographic FAT is less expensive than the other methods and readily accepted by the patients but its diagnostic performance does not recommend its use in the primary diagnosis, when the patient may have an active infection.

EFFECT OF ANTIOXIDANT POTENTIAL ON SEVERITY OF CIRRHOSIS IN HUMANS.

BACKGROUND/AIMS: to examine the relationship between the antioxidant potential and severity parameters of cirrhosis in humans. METHODS: fifteen patients with hepatic cirrhosis (nine subjects - Child group B, and six subjects - Child group C) and nine control subjects were enrolled in the study. The main criteria taken into account to characterize the diagnosis of cirrhosis and its complications were the AST: ALT ratio, AST to platelet ratio index, Bonacini score, Meld score and Child classification. Those parameters were determined based on laboratory results and patient's clinical records. Se, Zn, ascorbic acid (AA) levels and oxidative stress parameters were measured in blood samples of cirrhotic patients. RESULTS: the analysis of plasma levels of Se and AA showed low concentrations in cirrhotic patients compared with control subjects (P < 0.05). Though, there was a positive correlation between plasma of Se and severity parameters of cirrhosis in patients of Child group B and C. In the activity of the antioxidant enzymes only catalase was lower in patients of Child group C compared with control group. CONCLUSION: we found low plasma levels of Se and AA among cirrhotic patients. However, is not clear why selenium levels tend to increase with the severity of liver cirrhosis.

Introducción/Objetivos: examinar la relación entre los potenciales antioxidantes y los parámetros de gravedad de la cirrosis en los seres humanos. Métodos: quince pacientes con cirrosis hepática (nueve sujetos - grupo Child B, y seis sujetos - grupo Child C) y nueve sujetos control fueron incluidos en el estudio. Los principales criterios que se tuvieron en cuenta para caracterizar el diagnóstico de la cirrosis y sus complicaciones fueron la AST: relación de ALT, AST índice de la relación de plaquetas, clasificación Bonacini, clasificación MELD y clasificación de Child. Estos parámetros fueron determinados con base en los resultados de laboratorio y los registros clínicos del paciente. Se midieron los niveles de Zn, ácido ascórbico (AA) y los parámetros de estrés oxidativo en muestras de sangre de pacientes cirróticos. Resultados: el análisis de los niveles plasmáticos de Se y AA mostraron bajas concentraciones en los pacientes cirróticos en comparación con los sujetos control (P < 0,05); sin embargo, hubo una correlación positiva entre el plasma de Se y los parámetros de gravedad de la cirrosis en pacientes del grupo Child B y C. En la actividad de las enzimas antioxidantes catalasa solamente fue menor en los pacientes del grupo Child C, en comparación con el grupo control. Conclusión: se encontraron niveles bajos en plasma de Se y AA en pacientes cirróticos. Sin embargo, no está claro por qué los niveles de selenio tienden a aumentar con la gravedad de la cirrosis hepática.

Immunohistochemical expression of HER2 in adenocarcinoma of the stomach.

BACKGROUND: Worldwide, gastric cancer is the fourth cancer in incidence and the second most common cause of cancer death. Gastric cancer is asymptomatic in the early stages and very often diagnosed at advanced stages, determining a dismal prognosis. Expression of the HER2 gene has been identified in about 20% of gastric cancer cases, and its hyper-expression is associated with poor prognosis. OBJECTIVE: To investigate HER2 immunohistochemical expression in gastric adenocarcinoma and its relationship to the histological type and anatomic location. METHODS: A cross-sectional retrospective study analyzed the immunohistochemical expression of HER2 in a sample of 48 specimens of gastric cancer. Immunohistochemical analysis were performed using avidin-biotin-peroxidase method with C-erb B2 (clone EP1045Y), as a primary antibody (Biocare Medical, USA). Standardized gastric adenocarcinoma's HER2 expression criteria has been used in the analysis of samples. RESULTS: There were seven cases with reactivity for HER2. Five were of intestinal-type while two cases were of mixed-type in which the expression occurred in the intestinal component. It was identified a significant association of HER2 expression in the intestinal subtype of gastric adenocarcinoma (P=0.003). Regarding the anatomical site, HER2 was positive in only one (16.6%) of the six proximal cases and six (14.28%) of the 42 distal cases (P=0.88). CONCLUSION: HER2 immunoexpression was identified in 14.6% of the samples, and the expression was significantly associated to Lauren's intestinal subtype.

Immunohistochemccal expression of her2 in adenocarcinoma of the stomcch / Expressão imunoistoquímica do HER2 no adenocarcinoma de estômago

Background Worldwide, gastric cancer is the fourth cancer in incidence and the second most common cause of cancer death. Gastric cancer is asymptomatic in the early stages and very often diagnosed at advanced stages, determining a dismal prognosis. Expression of the HER2 gene has been identified in about 20% of gastric cancer cases, and its hyper-expression is associated with poor prognosis. Objective To investigate HER2 immunohistochemical expression in gastric adenocarcinoma and its relationship to the histological type and anatomic location. Methods A cross-sectional retrospective study analyzed the immunohistochemical expression of HER2 in a sample of 48 specimens of gastric cancer. Immunohistochemical analysis were performed using avidin-biotin-peroxidase method with C-erb B2 (clone EP1045Y), as a primary antibody (Biocare Medical, USA). Standardized gastric adenocarcinoma‘s HER2 expression criteria has been used in the analysis of samples. Results There were seven cases with reactivity for HER2. Five were of intestinal-type while two cases were of mixed-type in which the expression occurred in the intestinal component. It was identified a significant association of HER2 expression in the intestinal subtype of gastric adenocarcinoma (P=0.003). Regarding the anatomical site, HER2 was positive in only one (16.6%) of the six proximal cases and six (14.28%) of the 42 distal cases (P=0.88). Conclusion HER2 immunoexpression was identified in 14.6% of the samples, and the expression was significantly associated to Lauren’s intestinal subtype. .

Contexto O câncer gástrico ocupa o quarto lugar em incidência no mundo e é a segunda causa de óbito por neoplasia maligna. Por ser assintomático nas fases iniciais, na maioria das vezes, é diagnosticado em fases avançadas. A expressão do gene HER2 tem sido identificada em cerca de 20% dos casos de câncer gástrico e, sua hiper-expressão está associada a um pior prognóstico nestes pacientes. Objetivo Investigar a expressão imunoistoquímica do HER2 em espécimes de adenocarcinoma gástrico e sua relação com a classificação histológica e localização anatômica. Métodos Estudo transversal, retrospectivo, no qual foi analisada a expressão imunoistoquímica para o HER2, em uma amostra de 48 espécimes de câncer gástrico, através da técnica de imunoistoquímica, pelo método avidina-biotina-peroxidase utilizando anticorpo primário C-erb B2, clone EP1045Y (Biocare Medical, USA). Resultados Foram encontrados sete casos reativos para o HER2; destes, cinco eram casos de adenocarcinoma do tipo intestinal e dois eram casos do tipo misto, porém, nestes, a expressão ocorreu no componente intestinal, o que determinou uma associação significante da expressão de HER2 com o componente intestinal do adenocarcinoma gástrico (P=0,003). Em relação ao local anatômico, HER2 foi reativo em apenas um (16,6%) de seis casos proximais e seis (14,28%) dos 42 casos distais (P=0,88). Conclusão A expressão de HER2 ocorreu em 14,6% da amostra, associada significativamente ao subtipo intestinal de Lauren. .

Sternal osteomyelitis caused by infection with Mycobacterium tuberculosis.

We report the case of a 74-year-old male patient with a one-year history of chest pain in the suprasternal notch associated with erythema, edema and drainage of purulent material from a fistulous lesion. The patient was HIV-negative with no history of TB. A CT scan of the chest showed an osteolytic lesion in the sternum, and a biopsy revealed caseous granuloma, which, in the microbiological evaluation, was negative for fungi and acid-fast bacilli. The diagnosis of sternal osteomyelitis caused by Mycobacterium tuberculosis was confirmed using PCR.

Osteomielite esternal por Mycobacterium tuberculosis / Sternal osteomyelitis caused by infection with Mycobacterium tuberculosis

Descrevemos o caso de um paciente de 74 anos, masculino, com dor torácica na porção superior do esterno com um ano de evolução associada a eritema, edema e fístula com drenagem de material purulento. Paciente HIV negativo e sem história prévia de contato com TB. A TC de tórax evidenciou lesão osteolítica esternal, e o material de biópsia revelou granuloma caseoso negativo para fungos e bacilos álcool-ácido resistentes no exame microbiológico direto. O diagnóstico de osteomielite esternal por Mycobacterium tuberculosis foi realizado por PCR.

We report the case of a 74-year-old male patient with a one-year history of chest pain in the suprasternal notch associated with erythema, edema and drainage of purulent material from a fistulous lesion. The patient was HIV-negative with no history of TB. A CT scan of the chest showed an osteolytic lesion in the sternum, and a biopsy revealed caseous granuloma, which, in the microbiological evaluation, was negative for fungi and acid-fast bacilli. The diagnosis of sternal osteomyelitis caused by Mycobacterium tuberculosis was confirmed using PCR.

Transverse myelitis associated to HCV infection

Complications involving the central nervous system in patients suffering from hepatitis C virus (HCV) infectionhave been rare. Among them, it appears the transverse myelitis, which has already been reported in likely association with HCV. This paper presents the case study of a 65-year-old woman who developed cervical transverse myelitis linked to chronic HCV infection and anti-HCV antibodies in the spinal fluid, being excluded other etiologies for transverse myelitis. Current evidence has reinforced the likely association between chronic HCV infection and transverse myelitis, especially as recurrent manifestations of the disease. These findings reveal the need for more searching to establish the causal relationship between transverse myelitis and hepatitis C.

Transverse myelitis associated to HCV infection.

Complications involving the central nervous system in patients suffering from hepatitis C virus (HCV) infection have been rare. Among them, it appears the transverse myelitis, which has already been reported in likely association with HCV. This paper presents the case study of a 65-year-old woman who developed cervical transverse myelitis linked to chronic HCV infection and anti-HCV antibodies in the spinal fluid, being excluded other etiologies for transverse myelitis. Current evidence has reinforced the likely association between chronic HCV infection and transverse myelitis, especially as recurrent manifestations of the disease. These findings reveal the need for more searching to establish the causal relationship between transverse myelitis and hepatitis C.

[Neurofibroma of thyroid in a patient with neurofibromatosis type 1]. / Neurofibroma de tireóide em uma paciente com neurofibromatose tipo 1.

The neurofibromatosis type 1 (NF1), also known as von Recklinghausens disease, is an autosomal dominant disorder, with high degree of variability of clinical expression, usually involved with formation of tumors, with benign origin in the majority of cases mainly localized in the region of the head and neck and rarely incident in the thyroid area. However, the association with medullary carcinoma of the thyroid (MCT) exists in literature and needs to be excluded. We report a case of a patient with NF1, nonfunctional thyroid nodule and obstructive symptoms. Surgical resection of lesion was performed, with histopathologic findings compatible with neurofibroma in thyroid tissue. This case is relevant not only because of the rarity of the presentation of NF1, but also due to the likely association with MCT, an aggressive tumor that can be cured by surgery.

Neurofibroma de tireóide em uma paciente com neurofibromatose tipo 1 / Neurofibroma of thyroid in a patient with neurofibromatosis type 1

A neurofibromatose tipo 1 (NF1), também conhecida como doença de von Recklinghausen, é uma doença autossômica dominante com alto grau de variabilidade da expressão clínica, comumente envolvida na formação de tumorações na maioria das vezes de origem benigna, localizadas principalmente na região da cabeça e do pescoço, sendo a tireóide acometida raramente. Porém existe na literatura a associação com carcinoma medular da tireóide (CMT), necessitando sempre sua exclusão. Relatamos o caso de uma paciente com NF1, com um nódulo de tireóide não-funcionante e sintomas obstrutivos. Foi realizada ressecção cirúrgica da lesão, com achados histopatológicos compatíveis com neurofibroma em tecido tireoidiano. A importância desse caso deve-se não só à raridade dessa apresentação da NF1, mas também à possibilidade de associação desta com CMT, tumor agressivo com possibilidade de cura pela ressecção cirúrgica.

The neurofibromatosis type 1 (NF1), also known as von Recklinghausen’s disease, is an autosomal dominant disorder, with high degree of variability of clinical expression, usually involved with formation of tumors, with benign origin in the majority of cases mainly localized in the region of the head and neck and rarely incident in the thyroid area. However, the association with medullary carcinoma of the thyroid (MCT) exists in literature and needs to be excluded. We report a case of a patient with NF1, nonfunctional thyroid nodule and obstructive symptoms. Surgical resection of lesion was performed, with histopathologic findings compatible with neurofibroma in thyroid tissue. This case is relevant not only because of the rarity of the presentation of NF1, but also due to the likely association with MCT, an aggressive tumor that can be cured by surgery.

Identification of activated regions during a language task.

Functional magnetic resonance imaging (fMRI) techniques are based on the assumption that changes in neural activity are accompanied by modulation in the blood-oxygenation-level-dependent (BOLD) signal. In addition to conventional increases in BOLD signals, sustained negative BOLD signal changes are occasionally observed in many fMRI experiments, which show regions of cortex that seem to respond in antiphase with primary stimulus. The existence of this so-called negative BOLD response (NBR) has been observed and investigated in many functional studies. Several theoretical mechanisms have been proposed to account for it, but its origin has never been fully explained. In this study, the variability of fMRI activation, including the sources of the negative BOLD signal, during phonological and semantic language tasks, was investigated in six right-handed healthy subjects. We found significant activations in the brain regions, mainly in the left hemisphere, involved in the language stimuli [prominent in the inferior frontal gyrus, approximately Brodmann Areas (BA)7, BA44, BA45 and BA47, and in the precuneus]. Moreover, we observed activations in motor regions [precentral gyrus and supplementary motor area (SMA)], a result that suggests a specific role of these areas (particularly the SMA) in language processing. Functional analysis have also shown that certain brain regions, including the posterior cingulate cortex and the anterior cingulate cortex, have consistently greater activity during resting states compared to states of performing cognitive tasks. In our study, we observed diffuse NBR at the cortical level and a stronger negative response in correspondence to the main sinuses. These phenomena seem to be unrelated to a specific neural activity, appearing to be expressions of a mechanical variation in hemodynamics. We discussed about the importance of these responses that are anticorrelated with the stimulus. Our data suggest that particular care must be considered in the interpretation of fMRI findings, especially in the case of presurgical studies.

Quantitative evaluation for brain CT/MRI coregistration based on maximization of mutual information in patients with focal epilepsy investigated with subdural electrodes.

Patients with drug-resistant focal epilepsy may require intracranial investigations with subdural electrodes. These must be correctly localized with respect to the brain cortical surface and require appropriate monitoring. For this purpose, coregistration techniques, which fuse preimplantation 3D magnetic resonance imaging scans with postimplantation computed tomography scans, have been implemented. In order to reduce localization errors due to the fusion process, we used a coregistration method based on the maximization of mutual information (MI) in 11 patients with extratemporal epilepsy who were invasively investigated. Our registration method is based on three processing steps: rigid-body transformation for coregistration, computation of MI as a similarity measure and the use of the Downhill Simplex optimization method. After consistency analysis, the shift of the registration method reached 0.14+/-0.27 mm in translation and 0.03+/-0.14 degrees in rotation, and the accuracies assessed on voxels of skull surface and voxels of the center of the brain volume were 1.42+/-0.61 and 1.15+/-0.53 mm, respectively. The accuracy of the fusion process reached submillimeter range, and results were considered reliable for surgical planning in all studied patients.

Hemodynamic response (BOLD/fMRI) in focal epilepsy with reference to benzodiazepine effect.

We studied a new procedure of BOLD/fMRI acquisition in epilepsy. They use the benzodiazepine effect to achieve a more reliable baseline for statistical analysis. The method works only in the MR domain without EEG correlation. It compares the EPI images during interictal epileptic discharges and the images "inactivated" by benzodiazepine. The results in five out of eight patients show that this procedure in comparison with the EEG/fMRI method gives a net improvement of spatial definition of BOLD areas. These preliminary results seem to confirm the hypothesis that the better BOLD/fMRI procedure in epilepsy is to make use of physical features of MR that, unlike EEG, is not influenced by the distance of intercerebral sources and consequently allows a more complete and undistorted display of BOLD areas.