From Tissue Physoxia to Cancer Hypoxia, Cost-Effective Methods to Study Tissue-Specific O2 Levels in Cellular Biology.

The human body is endowed with an extraordinary ability to maintain different oxygen levels in various tissues and organs. The maintenance of physiological levels of oxygen is known as physoxia. The development of hypoxic conditions plays an important role in the biology of several pathologies, including cancer. In vitro studies using normal and neoplastic cells require that culture conditions be carried out under appropriate oxygen levels, either physoxic or hypoxic conditions. Such requirements are difficult to widely implement in laboratory practice, mainly due to the high costs of specialized equipment. In this work, we present and characterize a cost-effective method to culture cells under a range of oxygen levels using deoxidizing pouches. Our results show that physoxic and hypoxic levels using deoxidizing absorbers can be achieved either by implementing a gradual change in oxygen levels or by a regimen of acute depletion of oxygen. This approach triggers the activation of an epithelial-mesenchymal transition in cancer cells while stimulating the expression of HIF-1α. Culturing cancer cells with deoxidizing agent pouches revealed PI3K oncogenic pathway exacerbations compared to tumor cells growing under atmospheric levels of oxygen. Similar to the PI3K signaling disturbance, we also observed augmented oxidative stress and superoxide levels and increased cell cycle arrest. Most interestingly, the culture of cancer cells under hypoxia resulted in the accumulation of cancer stem cells in a time-dependent manner. Overall, we present an attractive, cost-effective method of culturing cells under appropriate physoxic or hypoxic conditions that is easily implementable in any wet laboratory equipped with cell culture tools.

MiR-612, miR-637, and miR-874 can Regulate VEGFA Expression in Hepatocellular Carcinoma Cell Lines.

MicroRNAs (miRNAs) are short non-coding RNA molecules acting as important posttranscriptional gene and protein expression regulators in cancer. The study goal was to examine VEGFA (vascular endothelial growth factor A) expression in hepatocellular carcinoma (HCC) cell lines upon transfection miR-612, miR-637, or miR-874. Methods: MiR-612 mimics, miR-637 mimics, or miR-874 inhibitors were transfected using Lipofectamine RNAiMax in both HCC cell lines, HepG2 and HuH-7. Real-time PCR, Western blotting, and ELISA methods were used to evaluate VEGFA regulation by the miRNAs. Results: Gene and protein expression levels of VEGFA were down-expressed in both cell lines, HepG2 and HuH-7, transfected with miR-612 or miR-637. Transfection with miR-874 inhibitor showed an increase in VEGFA gene expression in HepG2 and HuH-7 cell lines; however, no regulation was observed on VEGFA protein expression by miR-874 inhibition. Correlation analysis between miRNAs and VEGFA protein expression showed that miR-637 and miR-874 expression present inversely correlated to VEGFA protein expression. Conclusions: VEGFA was down-regulated in response to hsa-miR-612 or hsa-miR-637 overexpression; however, the modulation of VEGFA by miR-874 was observed only at the gene expression and thus, needs further investigation.

Alzheimer's Disease in the Down Syndrome: An Overview of Genetics and Molecular Aspects.

The overexpression of the amyloid precursor protein (APP) gene, encoded on chromosome 21, has been associated in Down syndrome (DS) with the development of early-onset Alzheimer's disease (EOAD). The increase in APP levels leads to an overproduction of amyloid-ß (Aß) peptide that accumulates in the brain. In response to this deposition, microglial cells are active and generate cascade events that include release cytokines and chemokine. The prolonged activation microglial cells induce neuronal loss, production of reactive oxygen species, neuron death, neuroinflammation, and consequently the development of Alzheimer's disease (AD). The intrinsically deficient immune systems in people with DS result in abnormalities in cytokine levels, which possibly contribute to the development of neurodegenerative disorders such as AD. Knowledge about the biomarkers involved in the process of neurodegeneration and neuroinflamation is important for understanding the mechanisms involved in the incidence and the precocity of AD in individuals with DS.

Differential expression of angiogenesis-related miRNAs and VEGFA in cirrhosis and hepatocellular carcinoma.

INTRODUCTION: Liver cirrhosis (LC) is a heterogeneous liver disease, the last stage of liver fibrosis, and the major risk factor for hepatocellular carcinoma (HCC). Our study aimed to evaluate the expression of microRNAs and the endothelial vascular growth factor (VEGFA) gene in LC and HCC. MATERIAL AND METHODS: The sample group consisted of 46 tissue samples: 21 of LC, 15 of HCC, and 10 of non-tumoural and non-cirrhotic liver tissue (control group). MiRNAs were chosen based on a mirDIP prediction database as regulators of the VEGFA gene. Gene expression of VEGF and miRNAs was quantified by real-time quantitative polymerase chain reaction. VEGFA protein expression was evaluated by ELISA. RESULTS: VEGFA gene expression was significantly overexpressed in LC compared to the control group (p < 0.0001). Hsa-miR-206 (p = 0.0313) and hsa-miR-637 (p = 0.0156) were down-expressed in LC. In HCC, hsa-miR-15b (p = 0.0010), hsa-miR-125b (p = 0.0010), hsa-miR-423-3p (p = 0.0010), hsa-miR-424 (p = 0.0313), hsa-miR-494 (p < 0.0001), hsa-miR-497 (p < 0.0001), hsa-miR-612 (p = 0.0078), hsa-miR-637 (p < 0.0001), and hsa-miR-1255b (p = 0.0156) presented down-expression. CONCLUSIONS: Overexpression of VEGFA in LC suggests impairment of angiogenesis in this tissue. The differential expression of microRNAs in LC and HCC observed in our study can lead to the evaluation of possible biomarkers for these diseases.

Skin wound healing triggers epigenetic modifications of histone H4.

BACKGROUND: The skin is the largest organ of the human body. Upon injury, the skin triggers a sequence of signaling pathways that induce epithelial proliferation, migration, and ultimately, the re-establishment of the epithelial barrier. Our study explores the unknown epigenetic regulations of wound healing from a histone perspective. Posttranslational modifications of histones enhance chromatin accessibility and modify gene transcription. METHODS: Full-thickness wounds were made in the dorsal skin of twenty-four C57/B6 mice (C57BL/6J), followed by the use of ring-shaped silicone splints to prevent wound contraction. Tissue samples were collected at three time points (post-operatory day 1, 4, and 9), and processed for histology. Immunofluorescence was performed in all-time points using markers for histone H4 acetylation at lysines K5, K8, K12, and K16. RESULTS: We found well-defined histone modifications associated with the stages of healing. Most exciting, we showed that the epidermis located at a distance from the wound demonstrated changes in histone acetylation, particularly the deacetylation of histone H4K5, H4K8, and H4K16, and hyperacetylation of H4K12. The epidermis adjacent to the wound revealed the deacetylation of H4K5 and H4K8 and hyperacetylation of H4K12. Conversely, the migratory epithelium (epithelial tongue) displayed significant acetylation of H4K5 and H4K12. The H4K5 and H4K8 were decreased in the newly formed epidermis, which continued to display high levels of H4K12 and H4K16. CONCLUSIONS: This study profiles the changes in histone H4 acetylation in response to injury. In addition to the epigenetic changes found in the healing tissue, these changes also took place in tissues adjacent and distant to the wound. Furthermore, not only deacetylation but also hyperacetylation occurred during tissue repair and regeneration.

Hypoxic niches are endowed with a protumorigenic mechanism that supersedes the protective function of PTEN.

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common malignancy worldwide and is characterized by a fast-paced growth. Like other solid tumors, the HNSCC growth rate results in the development of hypoxic regions identified by the expression of hypoxia-inducible factor 1α (HIF-1α). Interestingly, clinical data have shown that pharmacological induction of intratumoral hypoxia caused an unexpected rise in tumor metastasis and the accumulation of cancer stem cells (CSCs). However, little is known on the molecular circuitries involved in the presence of intratumoral hypoxia and the augmented population of CSCs. Here we explore the impact of hypoxia on the behavior of HNSCC and define that the controlling function of phosphatase and tensin homolog (PTEN) over HIF-1α expression and CSC accumulation are de-regulated during hypoxic events. Our findings indicate that hypoxic niches are poised to accumulate CSCs in a molecular process driven by the loss of PTEN activity. Furthermore, our data suggest that targeted therapies aiming at the PTEN/PI3K signaling may constitute an effective strategy to counteract the development of intratumoral hypoxia and the accumulation of CSCs.-Nascimento-Filho, C. H. V., Webber, L. P., Borgato, G. B., Goloni-Bertollo, E. M., Squarize, C. H., Castilho, R. M. Hypoxic niches are endowed with a protumorigenic mechanism that supersedes the protective function of PTEN.

Differential Expression of Prostaglandin I2 Synthase Associated with Arachidonic Acid Pathway in the Oral Squamous Cell Carcinoma.

INTRODUCTION: Differential expression of genes encoding cytochrome P450 (CYP) and other oxygenases enzymes involved in biotransformation mechanisms of endogenous and exogenous compounds can lead to oral tumor development. OBJECTIVE: We aimed to identify the expression profile of these genes, searching for susceptibility biomarkers in oral squamous cell carcinoma. PATIENTS AND METHODS: Sixteen oral squamous cell carcinoma samples were included in this study (eight tumor and eight adjacent non-tumor tissues). Gene expression quantification was performed using TaqMan Array Human CYP450 and other Oxygenases 96-well plate (Applied Biosystems) by real time qPCR. Protein quantification was performed by ELISA and IHC methods. Bioinformatics tools were used to find metabolic pathways related to the enzymes encoded by differentially expressed genes. Results. CYP27B1, CYP27A1, CYP2E1, CYP2R1, CYP2J2, CYP2U1, CYP4F12, CYP4X1, CYP4B1, PTGIS, ALOX12, and MAOB genes presented differential expression in the oral tumors. After correction by multiple tests, only the PTGIS (Prostaglandin I2 Synthase) gene presented significant differential expression (P < 0.05). The PTGIS gene and protein were reduced in oral tumors. CONCLUSION: PTGIS presents downexpression in oral tumors. PTGIS play an important role in the arachidonic acid metabolism. Arachidonic acid and/or metabolites are derived from this pathway, which can influence the regulation of important physiological mechanisms in tumorigenesis process.

Diffusion tensor MR imaging in neurofibromatosis type 1: expanding the knowledge of microstructural brain abnormalities.

BACKGROUND: Neurofibromatosis type 1 (NF1) is a hereditary disease with a dominant autosomal pattern. In children and adolescents, it is frequently associated with the appearance of T2-weighted hyperintensities in the brain's white matter. MRI with diffusion tensor imaging (DTI) is used to detect white matter abnormalities by measuring fractional anisotropy (FA). OBJECTIVE: This study employed DTI to evaluate the relationship between FA patterns and the findings of T2 sequences, with the aim of improving our understanding of anatomical changes and microstructural brain abnormalities in individuals with NF1. MATERIALS AND METHODS: Forty-four individuals with NF1 and 20 control subjects were evaluated. The comparative analysis of FA between NF1 and control groups was based on four predetermined anatomical regions of the brain hemispheres (basal ganglia, cerebellum, pons, thalamus) and related the presence or absence of T2-weighted hyperintensities in the brain, which are called unidentified bright objects (UBOs). RESULTS: The FA values between the groups demonstrated statistically significant differences (P ≤ 0.05) for the cerebellum and thalamus in patients with NF1, independent of the occurrence of UBOs. CONCLUSIONS: Diffusion tensor MR imaging confirms the influence of UBOs in the decrease of FA values in this series of patients with NF1. Additionally, this technique allows the characterization of microstructural abnormalities even in some brain regions that appear normal in conventional MR sequences.

Effect of stem cells seeded onto biomaterial on the progression of experimental chronic kidney disease.

Different routes for the administration of bone marrow-derived cells (BMDC) have been proposed to treat the progression of chronic renal failure (CRF). We investigated whether (1) the use of bovine pericardium (BP) as a scaffold for cell therapy would retard the progression of CRF and (2) the efficacy of cell therapy differently impacts distinct degrees of CRF. We used 2/3 and 5/6 models of renal mass reduction to simulate different stages of chronicity. Treatments consisted of BP seeded with either mesenchymal or mononuclear cells implanted in the parenchyma of remnant kidney. Renal function and proteinuria were measured at days 45 and 90 after cell implantation. BMDC treatment reduced glomerulosclerosis, interstitial fibrosis and lymphocytic infiltration. Immunohistochemistry showed decreased macrophage accumulation, proliferative activity and the expression of fibronectin and α-smooth muscle-actin. Our results demonstrate: (1) biomaterial combined with BMDC did retard the progression of experimental CRF; (2) cellular therapy stabilized serum creatinine (sCr), improved creatinine clearance and 1/sCr slope when administered during the less severe stages of CRF; (3) treatment with combined therapy decreased glomerulosclerosis, fibrosis and the expression of fibrogenic molecules; and (4) biomaterials seeded with BMDC can be an alternative route of cellular therapy.

Microscopical evaluation of extracellular matrix and its relation to the palatopharyngeal muscle in obstructive sleep apnea.

Obstructive sleep apnea hypopnea syndrome (SAHS) is a complex disease of the upper respiratory airways. SAHS physiopathology is multifactorial in which airway compliance is a very important component. To evaluate the tissue changes in the palatopharyngeal muscle by morphometric, histochemical, immunohistochemical, and stereological quantification, with special attention to extracellular matrix associated with this muscle at the structural and ultrastructural levels. Thirty patients with SAHS were divided into groups of 10 according to disease severity: mild, moderate, and severe SAHS. In addition, the control group consisted of 10 patients. Fragments of palatopharyngeal muscle removed from patients with SAHS and tonsillectomies from patients in the control group were histopathologically submitted to light microscopy and transmission electron microscopy. Histopathological evaluations by light and transmission electron microscopes showed differences in analyzed groups, such as reduction of the muscle fiber diameter in patients with SAHS, taking disease severity into consideration. In contrast, stereological analysis showed a gradual increase of the collagen and elastic system fibers relative frequencies, proportionally to SAHS seriousness. MMP-2 and MMP-9 immunostaining also showed an increased reaction in the muscle fiber cytoplasm and endomisium during SAHS progression. The ultrastructural analysis showed that palatopharyngeal muscle fibers presented cytoplasmic residual corpuscles, a sign of early cell aging. In conclusion, the increase of tissue compliance in individuals with SAHS can be, in addition to other factors, consequence of diminished contractile activity of the muscle fibers, which exhibited clear signs of early senescence. Moreover, extracellular matrix components changes may contribute to muscle myopathy during SAHS progression.

The association between CBS 844ins68 polymorphism and head and neck squamous cell carcinoma risk - a case-control analysis.

INTRODUCTION: Susceptibility to head and neck squamous cell carcinoma may be modified by functional polymorphisms in genes involved in the folate pathway, such as cystathionine beta-synthase (CBS). The CBS 844ins68 polymorphism is associated with DNA methylation changes and cancer development. MATERIAL AND METHODS: A case-control retrospective study was conducted in 322 patients with head and neck squamous cell carcinoma and in 531 control subjects without cancer. The polymerase chain reaction-restriction fragment length polymorphism technique was used to genotype the polymorphism. For statistical analysis, χ(2) test was conducted to examine whether the genotypic frequency of CBS 844ins68 was in Hardy-Weinberg equilibrium and multiple logistic regression was used for comparisons between groups, and for interactions between the polymorphism and risk factors and clinical histopathological parameters. RESULTS: No significant difference in CBS 844ins68 genotypic distribution was observed between the groups. Age > 50 years, male gender and tobacco consumption were predictors of the disease with increased risk of 7.89 (95% CI: 5.56-11.21), 2.49 (95% CI: 1.72-3.62), 6.44 (95% CI: 4.63-8.96) and 2.29 times (95% CI: 1.71-3.06) respectively. There was no association between the distribution of the CBS 844ins68 genotype and risk factors for this disease. According to clinical histopathological parameters, CBS 884ins68 polymorphism presented high frequency in oral cavity (p < 0.05) and patients with the polymorphism presented less survival time (p < 0.05). CONCLUSIONS: We concluded that the CBS 844ins68 polymorphism is not associated with HNSCC risk and there is increased risk of this disease in male gender individuals smokers aged over 50 years. In adittion, the polymorphism is more frequent in patients with oral cavity as primary site and in patients with less survival time.

Obstructive sleep apnea: lessons on clinic and surgery

Introdução: A síndrome da apnéia obstrutiva do sono (SAOS) é uma doença crônica e progressiva com alta morbimortalidade cardiovascular. A SAOS afeta 2-4% da população masculina entre 30 e 69 anos, e 1-2% da população feminina na mesma faixa etária, constituindo um problema de saúde pública. Fisiopatologia: A SAOS ocorre por associação de alterações anatômicas e um aumento na complacência da musculatura durante a passagem do ar. A musculatura das vias aéreas superiores relaxa durante o sono, causando uma redução das forças de dilatação das mesmas e episódios repetidos de obstrução. Cada obstrução é acompanhada por despertares e redução da saturação de oxigênio arterial, causando ativação aguda do sistema nervoso autônomo simpático com alterações cardiorrespiratórias. Aspectos Clínicos: Os sintomas da SAOS são noturnos e diurnos. Durante o sono, há a presença de roncos, pausas respiratórias, sono agitado, despertares e noctúria. Enquanto acordado, o paciente apresenta sintomas de sonolência diurna excessiva, dor de cabeça matinal, queda da função intelectual, sintomas depressivos, impotência sexual e distúrbios de personalidade. Os pacientes com SAOS são frequentemente homens, de meia-idade, com sobrepeso, pescoço curto, com alterações anatômicas das vias aéreas superiores. O diagnóstico definitivo é realizado por meio do estudo do sono através da polissonografia. Tratamento: O tratamento clínico inclui medidas comportamentais, como perda de peso, abstinência de álcool, sedativos, assim como o uso de dispositivos intra-orais removíveis ou pressão positiva contínua das vias aéreas (CPAP). Os tratamentos cirúrgicos visam aumentar o diâmetro das vias aéreas superiores e variam desde a uvulopalatofaringoplastia ao avanço maxilo-mandibular.

Introduction: Obstructive sleep apnea syndrome (OSAS) is a chronic disease that is progressive and impairing with high mortality and cardiovascular morbidity. OSAS affects 2-4% of the male population between 30 and69 years, and 1-2% of the female population in the same age range, thus constituting a public health problem. Physiopathology: OSAS occurs by association of physical disproportions, and an increase in complacency of this air passage. The musculature of upper airway (UA) passages relaxes during sleep, causing a reduction of UA dilating forces and repeated and intermediate episodes of obstruction. Each obstruction is accompanied by reduction in arterial oxygen saturation and the reaction of sleep interruption, causing repeated acute activation during sleep of the sympathetic autonomic nervous system with cardiorespiratory alterations that are already well-documented. Clinical Aspects: The symptoms of OSAS are nocturnal and occur at daytime as well. During sleep there is the presence of snoring, respiratory pauses, agitated sleep, multiple sleep interruptions and nocturia. While awake, the patient presents symptoms of excessive daytime somnolence and matinal headache, drop in intellectual function, depressive symptoms, sexual impotence and personality disorders. Typical OSAS patients are middle-aged overweight short-necked men with UA anatomical alterations. The definitive diagnosis is performed in the laboratory by means of a sleep study called Polysonography. Treatment: The clinical treatment includes behavioral measures such as weight loss and abstinence from alcohol and sedatives. Physical measures include the use of removable intra-oral devices or continuous positive airways pressure (CPAP). Surgical treatments aim at increasing UA and varies from Uvulopalatopharyngoplasty to maxillo-mandibular advance.

Associação do polimorfismo 936C>T do gene do Fator de Crescimento Endotelial Vascular (VEGF) com a Doença Arterial Coronariana / Association between VEGF 936C>T Polymorphism and Vascular Endothelial Growth Factor (VEGF) with Coronary Artery Disease

Introdução: O gene que codifica o fator de crescimento endotelial vascular (VEGF) tem sido investigado no desenvolvimento de doenças coronárias. Estudos apontam para um efeito protetor do VEGF no desenvolvimento da placa aterosclerótica, atuando como regulador da integridade endotelial vascular. O polimorfismo 936C>T do gene VEGF está associado com redução da síntese da proteína e parece desempenhar um importante papel no desenvolvimento da doença arterial coronariana (DAC). Objetivo: Investigar a relação entre o polimorfismo VEGF e presença, extensão e gravidade da DAC. Casuística e Métodos: Foram incluídos no estudo 50 pacientes com DAC confirmada por angiografia coronária e 50 indivíduos controles sem sinais angiográficos da doença. A genotipagem do polimorfismo VEGF 936C>T foi realizada por Reação em cadeia da polimerase, seguida de digestão enzimática. As análises estatísticas foram feitas por meio de teste Qui-quadrado, Teste exato de Fisher, Teste t e Regressão logística. Resultados: Tabagismo e Diabetes Mellitus (DM) foram mais freqüentes nos pacientes em relação aos controles (P = 0,015 e P = 0,013,respectivamente). As freqüências do alelo polimórfico foram 0,11 no grupo de pacientes e 0,17 no grupo controle (P = 0,308). A distribuição genotípica não diferiu significantemente entre os grupos (P = 0,397). Os genótipos VEGF 936C>T não foram associados ao número de vasos obstruídos (P = 0,452) ou grau deobstrução arterial (P = 0,681). Conclusão: O polimorfismo 936C>T do gene VEGF não apresentou associação com a DAC ou com a severidade da obstrução coronariana.

Introduction: The gene encoding vascular endothelial growth factor (VEGF) has been investigated in coronary artery disease progression. Studies point out protector effect of VEGF on atherosclerotic plaque development, playing regulating role of vascular endothelial integrity. The polymorphism VEGF 936C>T is associated with reduction of the protein synthesis, and could have an important role in coronary artery disease (CAD)development. Objective: To investigate the relationship between the VEGF 936C>T polymorphism and the presence, extension, and severity of CAD. Casuistics and Methods: Fifty patients with CAD confirme dangiographically, and 50 individuals without angiographic signs of the disease were included in the study. The genotyping of the VEGF 936C>T polymorphism was conducted by Polymerase chain reaction followed by enzyme digestion. Statistical analyses were performed by Chi-square, Exact Fisher test, Test t and Logistic regression. Results: Smoking and Diabetes Mellitus (DM) were frequent in patients compared to the controls(P = 0.015 and P = 0.013, respectively). The frequencies of the polymorphic allele were 0.11 in the CAD group and 0.17 in the control group (P = 0.308). Genotype distribution did not differ significantly between the groups (P = 0.397). The genotypes VEGF 936C>T were not associated to the number of blocked vessels (P= 0.452), or degree of arterial obstruction (P = 0.681). Conclusion: The polymorphism 936C>T of the VEGF gene did not present association with CAD or with severity of the coronary obstruction.

Identification of dysregulated genes in lymphocytes from children with Down syndrome.

The molecular mechanisms by which trisomy of human chromosome 21 disrupts normal development are not well understood. Global transcriptome studies attempting to analyze the consequences of trisomy in Down syndrome (DS) tissues have reported conflicting results, which have led to the suggestion that the analysis of specific tissues or cell types may be more productive. In the present study, we set out to analyze global changes of gene expression in lymphocytes from children with trisomy 21 by means of the serial analysis of gene expression (SAGE) methodology. Two SAGE libraries were constructed using pooled RNA of normal and Down syndrome children. Comparison between DS and normal profiles revealed that most of the transcripts were expressed at similar levels and functional classes of abundant genes were equally represented. Among the 242 significantly differentially expressed SAGE tags, several transcripts downregulated in DS code for proteins involved in T-cell and B-cell receptor signaling (e.g., PI3Kdelta, RGS2, LY6E, FOS, TAGAP, CD46). The SAGE data and interindividual variability were validated by real-time quantitative PCR. Our results indicate that trisomy 21 induces a modest dysregulation of disomic genes that may be related to the immunological perturbations seen in DS.

Estresse oxidativo e disfunção crônica do enxerto renal / Oxidative stress and renal cChronic aAllograft dDysfunction

A doença renal crônica (DRC) pode ser considerada um problema mundial de saúde pública e o transplante(Tx) renal é a melhor opção terapêutica e de reabilitação para pacientes com DRC em estágio terminal.Entretanto, a perda progressiva da função do Tx em conseqüência da disfunção crônica do enxerto (DCE) ainda constitui um sério problema sem terapêutica específica, constituindo a principal causa de falência desses Tx. Na presente revisão visamos mostrar o papel do estresse oxidativo (formação de Espécies Reativasde Oxigênio - EROs) na DCE, bem como o papel e a possível correlação entre as enzimas do grupo das glutationas.

Análise imunocitoquímica do padrão celular de neurofibromas em neurofibromatose tipo 1 (NF1) / Immunocytochemistry analysis of neurofibroma cell patterns in neurofibromatosis type 1 (NF1)

Neurofibromas múltiplos são as mais importantes características da NF1, uma das desordens genéticas autos-sômicas dominantes mais freqüentes no ser humano. Analisaram-se biópsias de 25 pacientes acometidos porNF1, investigando-se as variações no padrão celular dos diferentes neurofibromas, por meio de marcadores imunocitoquímicos para células de origem neuroectodérmica: S-100, GFAP e Ck35. As células dos neurofibro-mas mostraram-se positivas para S-100 (++++), GFAP (++) e Ck35 (+). Não houve diferenças no padrão de imunopositividade entre os diferentes tipos de neurofibromas do mesmo paciente (diferença focal heterotópica), assim como no mesmo tipo de neurofibroma entre os diferentes pacientes (variação individual)

Epidemiologia e biomarcadores em câncer de cabeça e pescoço / Head and neck cancer epidemiology and biomarkers

O presente artigo é uma revisão com o objetivo de atualizar os aspectos epidemiológicos e marcadores moleculares em câncer de cabeça e pescoço com ênfase nos fatores de riscos desta doença, na prevalência e nas novas descobertas de marcadores moleculares. Para isso foi realizado um levantamento bibliográfico para a obtenção destes dados. O câncer de cabeça e pescoço é responsável por uma grande incidência de óbitos e apresenta uma freqüência de aproximadamente 200.000 casos novos por ano. O tabagismo e o consumo de álcool são os principais fatores etiológicos dessa doença. A análise de marcadores moleculares é útil para a compreensão da fisiologia, diagnóstico, prognóstico, seleção de tratamentos e prevenção desta doença

Avaliação e características do erro médico na região de São José do Rio Preto / Evaluation and characteristics of medical errors in the region of São José do Rio Preto

O erro médico é o resultado adverso decorrente de ação inadequada ou omissão do profissional médico e pode ocorrer de três maneiras principais: imprudência, imperícia e negligência. Estudos epidemiológicos sobre o erro médico são escassos em todo o mundo, especialmente no Brasil e o assunto ainda é pouco abordado no currículo das escolas de medicina, embora amplamente divulgado pela mídia. o objetivo deste trabalho foi avaliar as características dos processos referentes a erro médico instaurados no Conselho Regional de Medicina do Estado de São Paulo - Delegacia Regional de São José do Preto (CREMESP-RP) e dos profissionais médicos a eles relacionados, no período de 1995 a 2000. A pesquisa foi elaborada usando-se uma planilha com os seguintes dados: tipo e resolução do processo, idade, sexo e especialidade do profissinal. Foram instaurados 41 processos no CREMESP-RP, envolvendo 61 médicos, 47 homens e 14 mulheres, com idade entre 40 e 65 anos. As razões mais frequentes dos processos foram relacionadas às condutas ético profissional (n=15) e negligência, imperícia, imprudência (n=6). As principais especialidades envolvidas foram Ortopedia e Traumatologia (n=14) e Cirurgia Geral (n=7). Conclui-se que os processos de erro médico foram mais frequentes nas especialidades cirúrgicas

Presence of the R1748X mutation in the NF1 gene in a Brazilian patient with ectropion uveae.

Congenital ectropion uveae is a rare, nonprogressive anomaly characterized by the presence of iris pigment epithelium on the anterior surface of the iris stroma and is occasionally associated with Rieger's anomaly, Prader-Willi syndrome and neurofibromatosis type 1 (NF1). The most important complication of ectropion uveae is congenital or juvenile glaucoma. We described a patient with ectropion and the mutation R1748X in the NF1 gene. This is the third report in the literature describing ectropion associated with neurofibromatosis. If this association is confirmed by other authors, the NF1 patients should be examined for the presence of ectropion and, consequently, for the development of glaucoma.

Mutational analysis of the GAP-related domain of the neurofibromatosis type 1 gene in Brazilian NF1 patients

Neurofibromatosis type 1 (NF1) is a common autosomal dominant disorder caused by mutations in the NF1 gene. In the present study, a total of 55 unrelated NF1 patients were screened for mutations in the GAP-related domain/GRD (exons 20-27a) by single-strand conformation polymorphism (SSCP). Four different mutations were identified and, taken together, they comprise one nonsense substitution (Q1189X), one deletion (3525-3526delAA), one missense substitution (E1356G) and one mutation in the splice acceptor site (c.4111-1G>A). One novel polymorphism (c.4514+11C>G) and other three putative polymorphisms were also found (c.3315-27G>A, V1146I and V1317A). Genotype-phenotype correlations were investigated, but no particular association was detected.