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1.
Epilepsy Res ; 154: 107-115, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31125838

RESUMO

Electrical stimulation (ES) of the nervous system is a promising alternative for the treatment of refractory epilepsy. Based on the understanding that seizures are the expression of neural hypersynchronism, our group developed and tested a non-standard form of low-energy temporally unstructured ES termed NPS (Non-periodic stimulation), with pseudo-randomized inter-pulse intervals. Previous investigation demonstrated that NPS applied to the amygdala has a robust anticonvulsant effect against both acute and chronic seizures, and suggested that its therapeutic effect is based on direct desynchronization of ictogenic neural circuits. Further mechanistic investigation using functional magnetic resonance imaging has shown that NPS also activates nucleus accumbens (NAc) in seizure-free rats, raising the hypothesis of an alternative therapeutic mechanism: NPS-enhanced indirect inhibition / desynchronization of ictogenic circuits by NAc. In order to investigate this idea, here we evaluated behavior and cortical electrographic activity from animals submitted to pentylenetetrazole (PTZ) induced seizures, treated with NPS and with or without bilateral electrolytic lesion of NAc. NPS-treated animals with bilateral lesion of NAc expressed unexpected straub tail in addition to other stereotypical convulsive behavior, displayed increased susceptibility to PTZ (lower drug threshold), and had a much longer electrographic seizure, with a greater number of spikes, firing at a higher rate. Moreover, analysis of spike morphology showed an increase in amplitude and slope in these animals, suggesting that ablation of NAc results in disinhibition and/or increase of neural synchronism within ictogenic circuits. NPS had no therapeutic effect whatsoever in lesioned animals, while it displayed a mild anticonvulsant effect in those with intact brains. Results corroborate the notion that NAc has a key role in controlling aberrant epileptiform activity in ictogenic circuits through indirect polysynaptic connections that may enroll the ventral pallidum and ventral tegmental area. They also point to the possibility that NPS may enhance this effect, putatively by benefiting from the structure's property of detecting saliences.


Assuntos
Potenciais de Ação/fisiologia , Tonsila do Cerebelo/fisiologia , Estimulação Encefálica Profunda/métodos , Eletroencefalografia/métodos , Núcleo Accumbens/fisiologia , Convulsões/terapia , Potenciais de Ação/efeitos dos fármacos , Tonsila do Cerebelo/efeitos dos fármacos , Animais , Eletroencefalografia/efeitos dos fármacos , Masculino , Núcleo Accumbens/efeitos dos fármacos , Pentilenotetrazol/toxicidade , Distribuição Aleatória , Ratos , Ratos Wistar , Convulsões/induzido quimicamente , Convulsões/fisiopatologia
2.
Epilepsy Res ; 146: 1-8, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30053674

RESUMO

A promising alternative for the treatment of refractory epilepsy is electrical stimulation (ES) of the central nervous system. Based on the premise that epilepsy is a result of neural hypersynchronization, we have previously demonstrated that a novel non-standard form of electrical stimulation with randomized inter-pulse intervals, termed non-periodic stimulation (NPS), applied to the amygdala is robustly anticonvulsant. This investigation also suggested that NPS attains its therapeutic effect by desynchronization of epileptiform activity. Here, we further explored the desynchronization hypothesis by testing how the efficacy of NPS in the suppression of convulsive behaviors depends on morphological, spatial, and temporal parameters of stimulus. For this purpose, we varied the number of pulse phases (monopolar versus bipolar square pulses), side of stimulation (right versus left), number of application hemispheres (unilateral versus bilateral), and interhemispheric temporal synchronicity (synchronous versus asynchronous), while measuring the impact on the anticonvulsant action of NPS. Wistar rats received a controlled infusion of the convulsant agent pentylenetetrazole (PTZ, 10 mg/min), together with one of six variations of NPS applied to the amygdala. A stimulated PTZ-free group of animals was also performed as a positive control. Latency to convulsive behavior was used to measure seizure threshold. Animals receiving NPS displayed significant higher threshold for forelimb clonus and generalized tonic-clonic seizures for all patterns. Thresholds seemed to increase gradually from mono to biphasic, unilateral to bilateral, and synchronous to asynchronous stimuli. Thus, combined biphasic, bilateral, and asynchronous stimulation resulted in the greatest seizure threshold. PTZ free animals did not develop any observable convulsive behavior or other uncommon motor activity. These results confirm that NPS has anticonvulsant properties and that biphasic, bilateral, and asynchronous stimulation enhances its efficacy. The fact that lack of synchronism between stimuli of each hemisphere maximizes NPS anticonvulsant power is evidence to desynchronization as tool for suppression of seizures.


Assuntos
Tonsila do Cerebelo/fisiopatologia , Estimulação Encefálica Profunda/métodos , Convulsões/fisiopatologia , Convulsões/terapia , Animais , Sincronização Cortical , Modelos Animais de Doenças , Epilepsia Resistente a Medicamentos/fisiopatologia , Epilepsia Resistente a Medicamentos/terapia , Estimulação Elétrica/métodos , Epilepsia Tônico-Clônica/fisiopatologia , Epilepsia Tônico-Clônica/terapia , Membro Anterior/fisiopatologia , Masculino , Pentilenotetrazol , Distribuição Aleatória , Ratos Wistar , Fatores de Tempo
3.
Arq. bras. med. vet. zootec. (Online) ; 70(6): 1845-1854, nov.-dez. 2018. tab, ilus
Artigo em Português | LILACS, VETINDEX | ID: biblio-970552

RESUMO

O número de transplantes de órgãos e tecidos em humanos e animais tem crescido significativamente nos últimos anos, principalmente após o advento de técnicas modernas e mais seguras indutoras de imunossupressão. Objetiva-se com o presente estudo avaliar macro e microscopicamente o alotransplante parcial de bexiga a fresco em coelhos, utilizando como agente imunomodulador células-tronco mesenquimais derivadas do tecido adiposo (ADSC) alogênicas. Foram utilizados 25 coelhos, sendo um deles macho e doador das ADSCs, e os outros 24 eram fêmeas, submetidas a alotransplante parcial de bexiga, tratadas com ciclosporina (GCi) ou células-tronco mesenquimais (GCe). Conclui-se que o GCe teve melhor aceitação histológica do implante em relação ao GCi aos 30 dias de avaliação.(AU)


The number of organ and tissue transplantation in humans and animals has grown significantly recently, especially after the advent of modern and safer techniques of immunosuppression. The objective of this study was to evaluate macro and microscopically partial urinary bladder fresh allograft in rabbits, using as immunomodulatory agent cyclosporine or allogenic adipose tissue derived mesenchymal stem cells (ADSCs). For this purpose, 25 rabbits were used. One male was the donor of ADSCs; 24 females received a partial urinary bladder allograft and were treated with cyclosporine (GCi) or mesenchymal stem cells (GCe). We conclude that the GCe group had better histological acceptance of the implant than GCi group at 30 days evaluation.(AU)


Assuntos
Animais , Coelhos , Coelhos/anatomia & histologia , Coelhos/genética , Alotransplante de Tecidos Compostos Vascularizados/veterinária , Mesoderma
4.
J Photochem Photobiol B ; 173: 538-544, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28692925

RESUMO

BACKGROUND: To evaluate for the first time in vivo the effects of methylene blue (MB) photosensitizer dissolved in ethanol in antimicrobial photodynamic therapy (aPDT) as adjuvant periodontal treatment, at plasmatic oxidative stress and vascular behavior in rat model. METHODS: Wistar rats were divided into negative control (NC, no periodontitis) and positive control (PC, with periodontitis, without any treatment). The other groups had periodontitis and were treated with scaling and root planing (SRP); SRP+aPDT+MB dissolved in water (aPDT I); SRP+aPDT+MB dissolved in ethanol (aPDT II). The periodontitis was induced by ligature at the mandibular right first molar. At 7/15/30days, rats were euthanized, the plasma was used to determine oxidative stress parameters and gingival tissue for histomorphometric analysis. RESULTS: PC showed higher thiobarbituric acid reactive substances levels in 7/15/30days. aPDT II was able to block the lipid peroxidation, especially between 15th and 30th days. Glutathione reduced levels were consumed in PC, aPDT I and II groups throughout the experiment. aPDT II increased the vitamin C levels which were restored in this group in the 30th day. aPDT II group showed the highest number of blood vessels. CONCLUSION: In summary, the aPDT with MB dissolved in ethanol provides better therapeutic responses in periodontitis treatment.


Assuntos
Anti-Infecciosos/farmacologia , Azul de Metileno/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Fármacos Fotossensibilizantes/farmacologia , Animais , Anti-Infecciosos/uso terapêutico , Ácido Ascórbico/sangue , Vasos Sanguíneos/efeitos dos fármacos , Vasos Sanguíneos/patologia , Vasos Sanguíneos/efeitos da radiação , Raspagem Dentária , Gengiva/patologia , Gengiva/efeitos da radiação , Glutationa/sangue , Luz , Masculino , Azul de Metileno/uso terapêutico , Estresse Oxidativo/efeitos da radiação , Periodontite/tratamento farmacológico , Periodontite/radioterapia , Fotoquimioterapia , Fármacos Fotossensibilizantes/uso terapêutico , Ratos , Ratos Wistar , Aplainamento Radicular
5.
Eur J Endocrinol ; 171(6): 761-7, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25565272

RESUMO

BACKGROUND: The role of key cell cycle regulation genes such as, CDKN1B, CDKN2A, CDKN2B, and CDKN2C in sporadic medullary thyroid carcinoma (s-MTC) is still largely unknown. METHODS: In order to evaluate the influence of inherited polymorphisms of these genes on the pathogenesis of s-MTC, we used TaqMan SNP genotyping to examine 45 s-MTC patients carefully matched with 98 controls. RESULTS: A multivariate logistic regression analysis demonstrated that CDKN1B and CDKN2A genes were related to s-MTC susceptibility. The rs2066827*GT+GG CDKN1B genotype was more frequent in s-MTC patients (62.22%) than in controls (40.21%), increasing the susceptibility to s-MTC (OR=2.47; 95% CI=1.048-5.833; P=0.038). By contrast, the rs11515*CG+GG of CDKN2A gene was more frequent in the controls (32.65%) than in patients (15.56%), reducing the risk for s-MTC (OR=0.174; 95% CI=0.048-0.627; P=0.0075). A stepwise regression analysis indicated that two genotypes together could explain 11% of the total s-MTC risk. In addition, a relationship was found between disease progression and the presence of alterations in the CDKN1A (rs1801270), CDKN2C (rs12885), and CDKN2B (rs1063192) genes. WT rs1801270 CDKN1A patients presented extrathyroidal tumor extension more frequently (92%) than polymorphic CDKN1A rs1801270 patients (50%; P=0.0376). Patients with the WT CDKN2C gene (rs12885) presented larger tumors (2.9±1.8 cm) than polymorphic patients (1.5±0.7 cm; P=0.0324). On the other hand, patients with the polymorphic CDKN2B gene (rs1063192) presented distant metastases (36.3%; P=0.0261). CONCLUSION: In summary, we demonstrated that CDKN1B and CDKN2A genes are associated with susceptibility, whereas the inherited genetic profile of CDKN1A, CDKN2B, and CDKN2C is associated with aggressive features of tumors. This study suggests that profiling cell cycle genes may help define the risk and characterize s-MTC aggressiveness.


Assuntos
Pontos de Checagem do Ciclo Celular/genética , Proteínas de Ciclo Celular/genética , Polimorfismo de Nucleotídeo Único , Neoplasias da Glândula Tireoide/genética , Adulto , Carcinoma Neuroendócrino , Estudos de Casos e Controles , Feminino , Predisposição Genética para Doença , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica , Metástase Neoplásica , Neoplasias da Glândula Tireoide/patologia
6.
J Endocrinol Invest ; 36(11): 975-81, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23723040

RESUMO

BACKGROUND: We previously identified a four-generation family with medullary thyroid cancer (MTC) and a germline p.Y791F RET mutation whose cancer lacked a strong genotype-phenotype correlation. The entire gene coding region of the RET gene should be sequenced when genotype-phenotype discrepancies are observed in patients with multiple endocrine neoplasia type 2 (MEN 2), even if a RET hotspot mutation has been identified. METHODS: A new genetic test was performed in the index case of this family with the p.Y791F RET germline mutation. The entire coding region of the RET gene was investigated by direct sequencing of PCR products. Once a mutation was identified, the target exon was sequenced in all at-risk relatives. RESULTS: An additional p.C634Y germline mutation in the RET gene was identified in the reported family. The double mutation occurred in cis and segregated with the phenotype. Through the Brazilian Genetic Screening Program developed at our institution, we additionally report the combination of these two mutations (p.C634Y/p.Y791F) in the RET gene in four other unrelated families. The overall penetrance of MTC and pheochromocytoma in patients with the p.C634Y/p.Y791F mutations was 79% and 13%, respectively. CONCLUSION: Our data emphasises that a comprehensive analysis of the RET gene may reveal multiple germline mutations in MEN 2 patients who exhibit an atypical clinical course of the disease.


Assuntos
Neoplasias das Glândulas Suprarrenais/genética , Carcinoma Medular/genética , Neoplasia Endócrina Múltipla Tipo 2a/genética , Proteínas Proto-Oncogênicas c-ret/genética , Neoplasias da Glândula Tireoide/genética , Adolescente , Adulto , Brasil , Calcitonina/sangue , Carcinoma Neuroendócrino , Feminino , Estudos de Associação Genética , Genótipo , Mutação em Linhagem Germinativa , Humanos , Masculino , Pessoa de Meia-Idade , Linhagem , Fenótipo , Feocromocitoma/genética
7.
Res Vet Sci ; 95(2): 389-97, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23706762

RESUMO

The aim of this study was to investigate functional and morphological alterations caused by oxidative stress in streptozotocin (STZ)-induced diabetic rats and to evaluate the antioxidant effect of quercetin (QUE) in this disease. One hundred and thirty male Wistar rats, it were randomly distributed in 10 different experimental groups, with ten animals per group: Control Saline (CS), Control Ethanol (CE), Control QUE 5mg/kg (CQ5), Control QUE 25mg/kg (CQ25), Control QUE 50mg/kg (CQ50), Diabetic Saline (DS), Diabetic Ethanol (DE), Diabetic QUE 5mg/kg (DQ5), Diabetic QUE25 mg/kg (DQ25), Diabetic QUE 50mg/kg (DQ50). Therefore, hyperglycemia is directly involved in oxidative stress production, as well as in functional and morphological alterations caused by the excess of free radicals. QUE, specially at the dosage of 50mg/kg, can act as an antioxidant and anti-inflammatory agent, becoming a promising adjuvant in the treatment of diabetes mellitus.


Assuntos
Anti-Inflamatórios/farmacologia , Antioxidantes/farmacologia , Diabetes Mellitus Experimental/patologia , Quercetina/farmacologia , Animais , Catalase/genética , Catalase/metabolismo , Regulação Enzimológica da Expressão Gênica/fisiologia , Peroxidação de Lipídeos/efeitos dos fármacos , Masculino , Ratos , Ratos Wistar , Superóxido Dismutase/genética , Superóxido Dismutase/metabolismo
8.
Clin Endocrinol (Oxf) ; 79(2): 288-93, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23278115

RESUMO

CONTEXT: Different inherited profiles of genes involved in cellular mechanisms of activation and detoxification of carcinogenic products can provide specific protection or determine the risk for cancer. Low-penetrance polymorphic genes related to the biotransformation of environmental toxins have been associated with susceptibility to and the phenotype of, human tumours. OBJECTIVE: To investigate the role of germline inheritance of polymorphisms in CYP1A2*F, CYP1A1 m1, GSTP1, NAT2 and TP53 genes in hereditary medullary thyroid carcinoma (HMTC) patients. DESIGN: This study was developed in University of Campinas (Unicamp). PATIENTS: We studied 132 patients with HMTC, 88 first-degree relatives of HMTC patients and 575 control individuals. MEASUREMENTS: All patients with MTC and their relatives were sequenced for the RET gene and five genes were genotyped using TaqMan(®) system. RESULTS: We observed that the inheritance of CYP1A2*F (OR = 2·10; 95% CI = 1·11-3·97; P = 0·022), GSTP1 (OR = 4·41; 95% CI = 2·47-7·88; P < 0·001) and NAT2 (OR = 2·54; 95% CI = 1·16-5·58; P = 0·020) variants increased the risk for HMTC. In addition, multiple regression analysis showed that the inheritance of GSTP1 polymorphisms was associated with the diagnosis in older patients (B = 8·0229; 95% IC = ± 5·5735; P = 0·0054). Concerning the group of HTMC relatives, CYP1A2*F (OR = 2:40; 95% CI = 1·19-4·86; P = 0·015), CYP1A1 m1 (OR = 2·79; 95% CI = 1:04-7·51; P = 0·042), GSTP1 (OR = 2·86; 95% IC = 1·53-5·32; P < 0·001) and NAT2 (OR = 2·25; 95% IC = 1·20-4·22; P = 0·012) were associated with HMTC risk. CONCLUSIONS: We have demonstrated that the inheritance of specific genes determining the individual response to environmental toxins may contribute to the risk and phenotypic variability that exists in patients with HMTC. Moreover, we identified a group at risk in relatives of HMTC patients.


Assuntos
Inativação Metabólica/genética , Neoplasias da Glândula Tireoide/genética , Adolescente , Adulto , Arilamina N-Acetiltransferase/genética , Carcinoma Neuroendócrino , Citocromo P-450 CYP1A1/genética , Citocromo P-450 CYP1A2/genética , Feminino , Predisposição Genética para Doença , Glutationa S-Transferase pi/genética , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Fenótipo , Polimorfismo Genético , Proteínas Proto-Oncogênicas c-ret/genética , Neoplasias da Glândula Tireoide/patologia , Proteína Supressora de Tumor p53/genética
9.
Eur J Endocrinol ; 166(2): 241-5, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22048975

RESUMO

AIM: Polymorphic low-penetrance genes have been consistently associated with the susceptibility to a series of human tumors, including differentiated thyroid cancer. METHODS: To determine their role in medullary thyroid cancer (MTC), we used TaqMan SNP method to genotype 47 sporadic MTC (s-MTC) and a control group of 578 healthy individuals for CYP1A2*F, CYP1A1m1, GSTP1, NAT2 and 72TP53. A logistic regression analysis showed that NAT2C/C (OR=3.87; 95% CI=2.11-7.10; P=2.2×10(-5)) and TP53C/C genotypes (OR=3.87; 95% CI=1.78-6.10; P=2.8×10(-4)) inheritance increased the risk of s-MTC. A stepwise regression analysis indicated that TP53C/C genotype contributes with 8.07% of the s-MTC risk. RESULTS: We were unable to identify any relationship between NAT2 and TP53 polymorphisms suggesting they are independent factors of risk to s-MTC. In addition, there was no association between the investigated genes and clinical or pathological features of aggressiveness of the tumors or the outcome of MTC patients. CONCLUSION: In conclusion, we demonstrated that detoxification genes and apoptotic and cell cycle control genes are involved in the susceptibility of s-MTC and may modulate the susceptibility to the disease.


Assuntos
Predisposição Genética para Doença , Inativação Metabólica/genética , Polimorfismo de Nucleotídeo Único , Neoplasias da Glândula Tireoide/genética , Adulto , Consumo de Bebidas Alcoólicas/epidemiologia , Consumo de Bebidas Alcoólicas/genética , Consumo de Bebidas Alcoólicas/metabolismo , Carcinoma Neuroendócrino , Estudos de Casos e Controles , Feminino , Frequência do Gene , Genótipo , Humanos , Masculino , Redes e Vias Metabólicas/genética , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único/fisiologia , Fumar/epidemiologia , Fumar/genética , Fumar/metabolismo , Neoplasias da Glândula Tireoide/epidemiologia , Neoplasias da Glândula Tireoide/metabolismo , Adulto Jovem
10.
Diabetes Metab ; 31(6): 599-602, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16357810

RESUMO

BACKGROUND: NEUROD1 encodes a transcription factor expressed in the endocrine pancreas, and involved in beta-cell development, function and mechanisms of apoptosis. In this study, we investigated the association of a frequent polymorphism in exon 2 of NEUROD1 (G > A; Ala45Thr) with Type 1 diabetes in Brazilian subjects. METHODS: A population/association study comprising 246 unrelated Type 1 diabetic and 275 nondiabetic white Brazilian subjects. The Ala45Thr variant was genotyped by a PCR-RFLP method. RESULTS: The frequency of the Thr allele was significantly higher in patients with Type 1 diabetes than in controls (42.3% vs 35.3%, P=0.02). Stratification by gender showed that homozygosity for the Thr allele was associated with Type 1 diabetes in women with odds ratio of 3.66 (95% C.I. 1.43-10.11, P=0.009) as compared to homozygosity for the Ala allele. This effect was not observed in men. CONCLUSIONS: We found a gender-specific association of the Ala45Thr variant of NEUROD1 with Type 1 diabetes in Brazilian women. Our results suggest that gender as well as ethnicity might modulate the association of NEUROD1 with Type 1 diabetes.


Assuntos
Substituição de Aminoácidos , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Diabetes Mellitus Tipo 1/genética , Polimorfismo de Nucleotídeo Único , Alanina , Brasil , Intervalos de Confiança , Feminino , Frequência do Gene , Sequências Hélice-Alça-Hélice , Humanos , Masculino , Razão de Chances , Valores de Referência , Caracteres Sexuais , Treonina
11.
Thyroid ; 15(3): 210-21, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15785240

RESUMO

To investigate the molecular events involved in the pathogenesis and/or progression of thyroid tumors, we compared the gene expression profiles of three thyroid carcinoma cell lines, which represent major tumor subtypes of thyroid cancer and normal thyroid tissue. Using cDNA array methodology, we investigated the expression of 1807 open reading frame expressed sequence tags (ORESTES), selected from head and neck tumor libraries generated through the Brazilian Human Cancer Project-LICR/FAPESP. We found that 505 transcripts were differentially expressed in the thyroid carcinoma cell lines. Using a more stringent criterion, transcripts underexpressed or overexpressed more than fivefold in 1 of 3 or 3 of 3 carcinoma cell lines, a list of 55 ESTs were detected. Five candidate genes were further validated by quantitative polymerase chain reaction (qPCR) in an independent set of 52 thyroid tumors and 22 matched normal thyroid tissues. DCN was found underexpressed in a high percentage of the follicular thyroid adenomas, follicular thyroid carcinomas, and follicular variant of papillary thyroid carcinomas. DIO1 and DIO2 were underexpressed in nearly all papillary thyroid carcinomas. These genes not only could help to better define a tumor signature for thyroid tumors, but may, in part, also become useful as potential targets for thyroid tumor treatment.


Assuntos
Perfilação da Expressão Gênica , Iodeto Peroxidase/genética , Proteoglicanas/genética , Glândula Tireoide/fisiologia , Neoplasias da Glândula Tireoide/genética , Adenocarcinoma Folicular/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Linhagem Celular Tumoral , Primers do DNA , Decorina , Proteínas da Matriz Extracelular , Feminino , Humanos , Isoenzimas/genética , Masculino , Pessoa de Meia-Idade , Análise de Sequência com Séries de Oligonucleotídeos , Fases de Leitura Aberta , Reação em Cadeia da Polimerase
12.
J Endocrinol Invest ; 26(6): 516-21, 2003 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12952364

RESUMO

Smad proteins have been shown tomediate the signal transduction pathway downstream of the transforming growth factor beta (TGFbeta). TGFbeta induces the phosphorylation of Smad2 and Smad3 which associate with Smad4 and translocate to the nucleus where they regulate gene transcription; besides these stimulatory Smads, the inhibitory Smads, Smad6 and Smad7, oppose signaling by blocking receptors and interrupting the phosphorylation of Smads2/3. The loss of TGFbeta-sensitivity, caused by inactivation of components of TGFbeta signaling, as Smad4, underlies a wide variety of human disorders, including cancer. In addition, the overexpression of the inhibitory Smad7, which prevents the phosphorylation of Smad2/3 and consequently inhibits TGFbeta signaling pathways, was observed in some diseases. In the present study we investigated the expression of Smad4 and Smad7 in thyroid cell lines (NPA papillary carcinoma, WRO follicular carcinoma and ARO anaplastic carcinoma) by RT-PCR and immunocytochemistry. Our results show that Smad4 was expressed in all thyroid cell lines and controls analyzed, differently from other classes of tumors where Smad4 expression was deleted. On the other hand, Smad7 was overexpressed in ARO anaplastic cell line, the most malignant follicular thyroid carcinoma. Our data suggest that the abrogation of the TGFbeta response by Smad7 overexpression may be a mechanism for the tumor aggressiveness observed in undifferentiated thyroid tumors.


Assuntos
Adenocarcinoma Folicular/metabolismo , Carcinoma Papilar/metabolismo , Carcinoma/metabolismo , Proteínas de Ligação a DNA/metabolismo , Fosfoproteínas/metabolismo , Neoplasias da Glândula Tireoide/metabolismo , Transativadores/metabolismo , Linhagem Celular Tumoral , Humanos , Imuno-Histoquímica , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Proteína Smad4 , Proteína Smad5
13.
Braz. j. med. biol. res ; 35(1): 65-68, Jan. 2002. ilus
Artigo em Inglês | LILACS | ID: lil-304202

RESUMO

Measurement of telomerase activity in clinically obtained tumor samples may provide important information for use as both a diagnostic marker and a prognostic indicator for patient outcome. In order to evaluate telomerase activity in tumor tissue without radiolabeling the product, we developed a simple telomeric repeat amplification protocol-silver-staining assay that is less time-consuming, is safe and requires minimal equipment. In addition, we determined the sensitivity of the silver-staining method by using extracts of telomerase-positive thyroid carcinoma cell lines which were serially diluted from 5,000 to 10 cells. Telomerase activity was also assayed in 19 thyroid tumors, 2 normal controls and 27 bone marrow aspirates. The results indicate that the technique permits the detection of telomerase activity from 5000 to as few as 10 cells. We propose that it could be immediately applicable in many laboratories due to the minimal amount of equipment required


Assuntos
Humanos , Coloração pela Prata , Telomerase , Telômero , Neoplasias da Glândula Tireoide , Ativação Enzimática , Biomarcadores Tumorais/metabolismo , Sensibilidade e Especificidade , Telomerase , Células Tumorais Cultivadas
14.
Braz J Med Biol Res ; 35(1): 65-8, 2002 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11743616

RESUMO

Measurement of telomerase activity in clinically obtained tumor samples may provide important information for use as both a diagnostic marker and a prognostic indicator for patient outcome. In order to evaluate telomerase activity in tumor tissue without radiolabeling the product, we developed a simple telomeric repeat amplification protocol-silver-staining assay that is less time-consuming, is safe and requires minimal equipment. In addition, we determined the sensitivity of the silver-staining method by using extracts of telomerase-positive thyroid carcinoma cell lines which were serially diluted from 5,000 to 10 cells. Telomerase activity was also assayed in 19 thyroid tumors, 2 normal controls and 27 bone marrow aspirates. The results indicate that the technique permits the detection of telomerase activity from 5000 to as few as 10 cells. We propose that it could be immediately applicable in many laboratories due to the minimal amount of equipment required.


Assuntos
Coloração pela Prata , Telomerase/metabolismo , Telômero , Neoplasias da Glândula Tireoide/enzimologia , Biomarcadores Tumorais/metabolismo , Ativação Enzimática , Humanos , Sensibilidade e Especificidade , Telomerase/análise , Células Tumorais Cultivadas/enzimologia
15.
Proc Natl Acad Sci U S A ; 98(21): 12103-8, 2001 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-11593022

RESUMO

Open reading frame expressed sequences tags (ORESTES) differ from conventional ESTs by providing sequence data from the central protein coding portion of transcripts. We generated a total of 696,745 ORESTES sequences from 24 human tissues and used a subset of the data that correspond to a set of 15,095 full-length mRNAs as a means of assessing the efficiency of the strategy and its potential contribution to the definition of the human transcriptome. We estimate that ORESTES sampled over 80% of all highly and moderately expressed, and between 40% and 50% of rarely expressed, human genes. In our most thoroughly sequenced tissue, the breast, the 130,000 ORESTES generated are derived from transcripts from an estimated 70% of all genes expressed in that tissue, with an equally efficient representation of both highly and poorly expressed genes. In this respect, we find that the capacity of the ORESTES strategy both for gene discovery and shotgun transcript sequence generation significantly exceeds that of conventional ESTs. The distribution of ORESTES is such that many human transcripts are now represented by a scaffold of partial sequences distributed along the length of each gene product. The experimental joining of the scaffold components, by reverse transcription-PCR, represents a direct route to transcript finishing that may represent a useful alternative to full-length cDNA cloning.


Assuntos
Etiquetas de Sequências Expressas , Genoma Humano , Fases de Leitura Aberta , Transcrição Gênica , Humanos
16.
Braz J Med Biol Res ; 34(2): 259-63, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11175503

RESUMO

Estradiol has well-known indirect effects on the thyroid. A direct effect of estradiol on thyroid follicular cells, increasing cell growth and reducing the expression of the sodium-iodide symporter gene, has been recently reported. The aim of the present investigation was to study the effect of estradiol on iodide uptake by thyroid follicular cells, using FRTL-5 cells as a model. Estradiol decreased basal iodide uptake by FRTL-5 cells from control levels of 2.490 +/- 0.370 to 2.085 +/- 0.364 pmol I-/microg DNA at 1 ng/ml (P<0.02), to 1.970 +/- 0.302 pmol I-/microg DNA at 10 ng/ml (P<0.003), and to 2.038 +/- 0.389 pmol I-/microg DNA at 100 ng/ml (P<0.02). In addition, 4 ng/ml estradiol decreased iodide uptake induced by 0.02 mIU/ml thyrotropin from 8.678 +/- 0.408 to 7.312 +/- 0.506 pmol I-/microg DNA (P<0.02). A decrease in iodide uptake by thyroid cells caused by estradiol has not been described previously and may have a role in goiter pathogenesis.


Assuntos
Estradiol/farmacologia , Iodetos/metabolismo , Glândula Tireoide/efeitos dos fármacos , Tireotropina/farmacologia , Análise de Variância , Animais , Técnicas de Cultura de Células , Células Cultivadas , Ratos , Estatísticas não Paramétricas , Glândula Tireoide/citologia , Glândula Tireoide/metabolismo
17.
Braz. j. med. biol. res ; 34(2): 259-263, Feb. 2001.
Artigo em Inglês | LILACS | ID: lil-281605

RESUMO

Estradiol has well-known indirect effects on the thyroid. A direct effect of estradiol on thyroid follicular cells, increasing cell growth and reducing the expression of the sodium-iodide symporter gene, has been recently reported. The aim of the present investigation was to study the effect of estradiol on iodide uptake by thyroid follicular cells, using FRTL-5 cells as a model. Estradiol decreased basal iodide uptake by FRTL-5 cells from control levels of 2.490 0.370 to 2.085 0.364 pmol I-/æg DNA at 1 ng/ml (P<0.02), to 1.970 0.302 pmol I-/æg DNA at 10 ng/ml (P<0.003), and to 2.038 0.389 pmol I-/æg DNA at 100 ng/ml (P<0.02). In addition, 4 ng/ml estradiol decreased iodide uptake induced by 0.02 mIU/ml thyrotropin from 8.678 0.408 to 7.312 0.506 pmol I-/æg DNA (P<0.02). A decrease in iodide uptake by thyroid cells caused by estradiol has not been described previously and may have a role in goiter pathogenesis


Assuntos
Animais , Ratos , Estradiol/farmacologia , Iodetos/metabolismo , Glândula Tireoide/citologia , Tireotropina/farmacologia , Análise de Variância , Técnicas de Cultura de Células , Células Cultivadas , Estatísticas não Paramétricas , Glândula Tireoide/efeitos dos fármacos
18.
Proc Natl Acad Sci U S A ; 97(23): 12690-3, 2000 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-11070084

RESUMO

Transcribed sequences in the human genome can be identified with confidence only by alignment with sequences derived from cDNAs synthesized from naturally occurring mRNAs. We constructed a set of 250,000 cDNAs that represent partial expressed gene sequences and that are biased toward the central coding regions of the resulting transcripts. They are termed ORF expressed sequence tags (ORESTES). The 250,000 ORESTES were assembled into 81,429 contigs. Of these, 1, 181 (1.45%) were found to match sequences in chromosome 22 with at least one ORESTES contig for 162 (65.6%) of the 247 known genes, for 67 (44.6%) of the 150 related genes, and for 45 of the 148 (30.4%) EST-predicted genes on this chromosome. Using a set of stringent criteria to validate our sequences, we identified a further 219 previously unannotated transcribed sequences on chromosome 22. Of these, 171 were in fact also defined by EST or full length cDNA sequences available in GenBank but not utilized in the initial annotation of the first human chromosome sequence. Thus despite representing less than 15% of all expressed human sequences in the public databases at the time of the present analysis, ORESTES sequences defined 48 transcribed sequences on chromosome 22 not defined by other sequences. All of the transcribed sequences defined by ORESTES coincided with DNA regions predicted as encoding exons by genscan. (http://genes.mit.edu/GENSCAN.html).


Assuntos
Cromossomos Humanos Par 22 , Transcrição Gênica , Etiquetas de Sequências Expressas , Perfilação da Expressão Gênica , Humanos , Fases de Leitura Aberta
19.
J Clin Endocrinol Metab ; 85(10): 3623-7, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11061512

RESUMO

To investigate whether circulating thyroglobulin (Tg) messenger ribonucleic acid (mRNA) and sodium/iodide symporter (NIS) mRNA transcripts in peripheral blood are valuable in the follow-up of patients with thyroid cancer, we developed highly sensitive nested Tg and NIS mRNA detection assays and compared their accuracy with serum thyroglobulin (sTg) and whole body scan with 131I during the monitoring of 34 patients with well differentiated thyroid carcinoma who had undergone total thyroidectomy (17 of 34 also submitted to thyroid ablation with radioiodine) and were taking T4. Circulating Tg mRNA was found in 13 of 34 patients, 5 of 13 with detectable and 8 of 13 with undetectable sTg. From these 8 patients with undetectable Tg, 6 showed no cervical radioiodine uptake, and 3 presented proven metastatic disease (2 of them positive for antithyroglobulin antibodies). NIS mRNA was detected in 11 of 34 patients, but its measurement did not improve the ability to detect patients with metastases. Overall, identification of metastatic thyroid cancer was better associated with Tg mRNA than with NIS mRNA, sTg, or whole body scan (83% vs. 16.6% vs. 50% vs. 50%; P < 0.001). These data showed that circulating Tg mRNA is not only a more sensitive marker of residual thyroid tissue or thyroid cancer than sTg, particularly in patients during T4 therapy and with positive antithyroglobulin antibodies, but also was more sensitive than NIS mRNA in all patients.


Assuntos
Adenocarcinoma Folicular/diagnóstico , Adenocarcinoma Papilar/diagnóstico , Proteínas de Transporte/sangue , Proteínas de Membrana/sangue , RNA Mensageiro/sangue , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Simportadores , Tireoglobulina/sangue , Neoplasias da Glândula Tireoide/diagnóstico , Adenocarcinoma Folicular/sangue , Adenocarcinoma Papilar/sangue , Adulto , DNA/análise , DNA/genética , Feminino , Humanos , Masculino , RNA Mensageiro/isolamento & purificação , Recidiva , Neoplasias da Glândula Tireoide/sangue , Transcrição Gênica
20.
Sao Paulo Med J ; 118(5): 144-7, 2000 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-11018848

RESUMO

CONTEXT: Screening programs not only offer the opportunity to trace and treat almost all cases of congenital hypothyroidism but also mean large savings to the health system. However, carefully planned strategies are necessary to extend their benefits and reduce costs. OBJECTIVE: To determine the possible influence of maternal diseases that affect maternal-fetal placenta dynamics on primary thyroid stimulating hormone (TSH) screening for congenital hypothyroidism. DESIGN: Prospective non-randomized clinical trial with at least 3 months of follow-up. SETTING: A public university referral center [CAISM/Hospital das Clínicas, Faculty of Medicine, University of Campinas, Campinas, SP]. PARTICIPANTS: 415 neonates divided into 5 groups: eighty-three infants born from cardiac mothers; 98 from mothers that had toxemia; 54 of the mothers had diabetes mellitus; 40 were HIV positive and 140 had no diseases. INTERVENTION: All newborns had cord blood samples collected on filter paper at birth. MAIN MEASUREMENTS: TSH was measured from dried blood spots using a homemade immunofluorescence assay (sensitivity in dried blood spots = 0.1 mU/L). RESULTS: There was no significant difference in the mean TSH levels among the 5 groups. Moreover, TSH levels were around 5 mU/L in 48% of the newborns, indicating that our region is severely deficient in iodine. CONCLUSIONS: Our results indicate that primary TSH screening programs using cord blood are not affected by maternal diseases. We suggest that, besides its technical advantages over heel punctures with T4 primary approaches, neonatal screening using primary cord blood TSH may also be used as a monitoring tool for evaluation and control of iodine deficiency disorders (IDD).


Assuntos
Sangue Fetal/química , Hipotireoidismo/diagnóstico , Complicações na Gravidez , Tireotropina/sangue , Síndrome de Imunodeficiência Adquirida , Hipotireoidismo Congênito , Diabetes Mellitus , Feminino , Seguimentos , Cardiopatias , Humanos , Recém-Nascido , Masculino , Mães , Triagem Neonatal , Pré-Eclâmpsia , Gravidez , Estudos Prospectivos
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