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1.
Pflugers Arch ; 476(8): 1235-1247, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38856775

RESUMO

To assess the possible interactions between the dorsolateral periaqueductal gray matter (dlPAG) and the different domains of the nucleus ambiguus (nA), we have examined the pattern of double-staining c-Fos/FoxP2 protein immunoreactivity (c-Fos-ir/FoxP2-ir) and tyrosine hydroxylase (TH) throughout the rostrocaudal extent of nA in spontaneously breathing anaesthetised male Sprague-Dawley rats during dlPAG electrical stimulation. Activation of the dlPAG elicited a selective increase in c-Fos-ir with an ipsilateral predominance in the somatas of the loose (p < 0.05) and compact formation (p < 0.01) within the nA and confirmed the expression of FoxP2 bilaterally in all the domains within the nA. A second group of experiments was made to examine the importance of the dlPAG in modulating the laryngeal response evoked after electrical or chemical (glutamate) dlPAG stimulations. Both electrical and chemical stimulations evoked a significant decrease in laryngeal resistance (subglottal pressure) (p < 0.001) accompanied with an increase in respiratory rate together with a pressor and tachycardic response. The results of our study contribute to new data on the role of the mesencephalic neuronal circuits in the control mechanisms of subglottic pressure and laryngeal activity.


Assuntos
Estimulação Elétrica , Laringe , Substância Cinzenta Periaquedutal , Proteínas Proto-Oncogênicas c-fos , Ratos Sprague-Dawley , Animais , Masculino , Ratos , Substância Cinzenta Periaquedutal/metabolismo , Substância Cinzenta Periaquedutal/fisiologia , Estimulação Elétrica/métodos , Proteínas Proto-Oncogênicas c-fos/metabolismo , Laringe/fisiologia , Laringe/metabolismo , Fatores de Transcrição Forkhead/metabolismo , Tirosina 3-Mono-Oxigenase/metabolismo , Pressão , Bulbo/metabolismo , Bulbo/fisiologia , Ácido Glutâmico/metabolismo
2.
Pflugers Arch ; 475(4): 505-516, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36543918

RESUMO

Stimulation of the dorsolateral periaqueductal grey matter (dlPAG) in rats evokes an active defensive behaviour together with a cardiorespiratory response characterised by tachypnoea, tachycardia and hypertension. The dlPAG neurons involved in these responses are excitatory, presumably glutamatergic, due to the presence of vesicular glutamate transporter VGLUT2 within their axon terminals. Previously, our group described a functional interaction between dlPAG and the pontine A5 region. Accordingly, in the present work, in order to characterize the role of glutamate within this interaction, experiments were carried out in spontaneously breathing anaesthetized rats (sodium pentobarbitone 60 mg/kg i.p., suplemented with 20 mg/kg i.p.). The cardiorespiratory response evoked by electrical stimulation of the dlPAG (1 ms pulses, 20-50 µA, given at 100 Hz, during 5 s) was analysed before and after the microinjection, within the A5 region, of either kynurenic acid (non-specific glutamate receptor antagonist; 5-10 nmol), DAP-5 (NMDA antagonist; 1 pmol), CNQX (non-NMDA antagonist; 1 pmol) or MCPG (metabotropic antagonist; 0,1 nmol). Kynurenic acid decreased the intensity of both the tachypnoea (p < 0,001) and tachycardia (p < 0,001) induced by dl-PAG stimulation. Blockade of no-NMDA receptors reduced the increase of respiratory frequency, heart rate and pressor response to dl-PAG stimulation (p < 0,01, p < 0,001, p < 0,05 respectively). Blockade of either NMDA or metabotropic receptors reduced the dlPAG-evoked tachycardia and pressor response (p < 0,01; p < 0,05 respectively). These results suggest a neuromodulatory role for A5 region via glutamate neurotransmission of the dlPAG-evoked cardiorespiratory response, confirming the role of the ventrolateral pons in the neuronal circuits involved in respiratory and heart rate control.


Assuntos
Ácido Cinurênico , Taquicardia , Ratos , Animais , Ácido Cinurênico/farmacologia , Frequência Cardíaca/fisiologia , Substância Cinzenta Periaquedutal , Ácido Glutâmico/farmacologia , Transmissão Sináptica , Taquipneia
3.
Arch Virol ; 160(9): 2209-17, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26100402

RESUMO

Hepatitis B virus (HBV) infection is a serious global health problem. Approximately 2 billion people worldwide have been infected, and approximately 350 million individuals currently suffer from HBV-induced chronic liver infection, which causes 600,000 deaths annually from chronic hepatitis, cirrhosis and hepatocellular carcinoma. HBV is classified in eight genotypes (A-H), and two more have been proposed (I-J). In this paper, complete genome sequences of nine Uruguayan HBV are reported. Five samples belong to genotype F1b and one to genotype A2. Three HBV recombinants were detected: A1/F1b, A2/F1b and D3/F1b. The following mutations were detected: a G1896A substitution, a 33-nucleotide deletion from position 2896 to 2928 in the Pre-S1 region involving Pre-S1 residues 3-13, a 33-nt deletion in the Pre-S1 region involving nt 2913-2945 and Pre-S1 residues 9-19. More F genotypes strains than expected were detected in this study, supporting the hypothesis that there are more people of indigenous origin than declared in our population. Also, one third of the samples analyzed were recombinants. This cannot be explained by the low HBV prevalence in Uruguay, but a high HBV infection rate in drug addicts and dialysis patients could act in favor of multiple-genotype HBV infections that could lead to recombination.


Assuntos
DNA Viral/genética , Variação Genética , Vírus da Hepatite B/classificação , Vírus da Hepatite B/genética , Hepatite B/virologia , Adulto , DNA Viral/química , Feminino , Genoma Viral , Genótipo , Vírus da Hepatite B/isolamento & purificação , Humanos , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Mutação , Recombinação Genética , Análise de Sequência de DNA , Uruguai , Adulto Jovem
4.
Exp Physiol ; 98(8): 1279-94, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23525246

RESUMO

In order to assess the possible interactions between the pontine A5 region and the hypothalamic defence area (HDA), we have examined the pattern of double staining for c-Fos protein immunoreactivity (c-Fos-ir) and tyrosine hydroxylase, throughout the rostrocaudal extent of the A5 region in spontaneously breathing anaesthetized male Sprague-Dawley rats during electrical stimulation of the HDA. Activation of the HDA elicited a selective increase in c-Fos-ir with an ipsilateral predominance in catecholaminergic and non-catecholaminergic A5 somata (P < 0.001 in both cases). A second group of experiments was done to examine the importance of the A5 region in modulating the cardiorespiratory response evoked from the HDA. Cardiorespiratory changes were analysed in response to electrical stimulation of the HDA before and after ipsilateral microinjection of muscimol within the A5 region. Stimulation of the HDA evoked an inspiratory facilitatory response, consisting of an increase in respiratory rate (P < 0.001) due to a decrease in expiratory time (P < 0.01). The respiratory response was accompanied by a pressor response (P < 0.001) and tachycardia (P < 0.001). After muscimol microinjection within the A5 region, pressor and heart rate responses to HDA stimulation were reduced (P < 0.01 and P < 0.001, respectively). The respiratory response persisted unchanged. Finally, to confirm functional interactions between the HDA and the A5 region, extracellular recordings of putative A5 neurones were obtained during HDA stimulation. Seventy-five A5 cells were recorded, 35 of which were affected by the HDA (47%). These results indicate that neurones of the A5 region participate in the cardiovascular response evoked from the HDA. The possible mechanisms involved in these interactions are discussed.


Assuntos
Hipotálamo/fisiologia , Hipotálamo/fisiopatologia , Neurônios/fisiologia , Ponte/fisiologia , Ponte/fisiopatologia , Taquicardia/fisiopatologia , Animais , Sistema Cardiovascular/metabolismo , Sistema Cardiovascular/fisiopatologia , Estimulação Elétrica/métodos , Frequência Cardíaca/fisiologia , Hipotálamo/metabolismo , Masculino , Neurônios/metabolismo , Ponte/metabolismo , Proteínas Proto-Oncogênicas c-fos/metabolismo , Ratos , Ratos Sprague-Dawley , Respiração , Taquicardia/metabolismo , Tirosina 3-Mono-Oxigenase/metabolismo
5.
Front Physiol ; 14: 1242847, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37711460

RESUMO

Escape room's popularity has raised over the past years among young adults. It creates a distended competitive environment, where participants collaborate to achieve a common objective through teamwork. We decided to apply this format as a teaching method for medical students at the University of Malaga, Spain. A peer-to-peer physiological cardiorespiratory escape room was designed by intern undergraduate students, collaborating within the Department of Human Physiology. This activity integrated the contents of the Human Physiology syllabus, which were organized into four stages that culminated in a final medical case. Intern students oversaw the design, promotion, preparation and execution of the activity, and were in charge of conducting the evaluation and follow up. The escape room was done in mid-December, after all theoretical and practical contents had been delivered, for four consecutive years, improving from each year's experience. The target group for this activity were second year medical students, who were asked to team up freely in groups of four to six students before the start of the activity. The students in each group cooperated with each other while trying to solve the different puzzles and questions in each stage of the escape room. After the activity, the results of the final evaluation exam of these participants were compared against non-participants, who served as a control group. Qualitative feedback was also received from the participants via a special survey that was designed for this task. Results between 2020 and 2023 (three last activities) show that the final mark of the participants was significantly higher than in non-participants (6.39 ± 0.14 vs. 5.04 ± 0.2; p < 0.0007). The global exam mark also increased in the participants (5.43 ± 0.10 vs. 4.44 ± 0.15; p < 0.0007). A significant difference was observed in the performance in cardiovascular (p < 0.0007) and respiratory-related questions (p < 0.0007), which was substantial in the participants. The qualitative feedback received from the participants was mainly positive, indicating an overall acceptance of the format by the students. We conclude that escape room format with a peer-to-peer structure is an efficient teaching tool for medical students performed by medical students in the field of Human Physiology.

6.
J Pathol ; 217(4): 516-23, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18991334

RESUMO

Amplification of the 11q13 region is a prevalent genetic alteration in head and neck squamous cell carcinoma (HNSCC). We investigated the clinical significance of cortactin (CTTN) and cyclin D1 (CCND1) amplification in both malignant transformation and tumour progression. CTTN and CCND1 amplification was analysed by differential and real-time PCR in a prospective series of laryngeal/pharyngeal carcinomas and archival premalignant tissues. CTTN mRNA and protein expression were respectively determined by real-time RT-PCR and immunohistochemistry, and correlated with gene status. Molecular alterations were associated with clinicopathological parameters and disease outcome. CTTN and CCND1 amplifications were respectively found in 75 (37%) and 90 (45%) tumours. Both correlated with advanced disease; however, only CTTN amplification was associated with recurrence and reduced disease-specific survival (p = 0.0022). Strikingly, CTTN amplification differentially influenced survival depending on tumour site (p = 0.0001 larynx versus p = 0.68 pharynx) and was an independent predictor of reduced survival in the larynx (p = 0.04). CCND1 amplification was detected in early tumourigenesis and increased with the severity of dysplasia. Importantly, CTTN amplification was only found in high-grade dysplasias that progressed to invasive carcinoma. CTTN gene status strongly correlated with mRNA and protein expression. Furthermore, CTTN overexpression correlated significantly with reduced disease-specific survival (p = 0.018). Taken together, these data indicate that CTTN may serve as a valuable biomarker to identify patients with laryngeal tumours at high risk of recurrence and poor outcome.


Assuntos
Carcinoma de Células Escamosas/genética , Cromossomos Humanos Par 11 , Cortactina/genética , Regulação Neoplásica da Expressão Gênica , Neoplasias de Cabeça e Pescoço/genética , Recidiva Local de Neoplasia/genética , Biomarcadores Tumorais/análise , Carcinoma de Células Escamosas/mortalidade , Carcinoma de Células Escamosas/patologia , Cortactina/análise , Cortactina/metabolismo , Ciclina D1/análise , Ciclina D1/genética , Ciclina D1/metabolismo , Feminino , Amplificação de Genes , Neoplasias de Cabeça e Pescoço/mortalidade , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/mortalidade , Recidiva Local de Neoplasia/patologia , Estadiamento de Neoplasias , Prognóstico , Modelos de Riscos Proporcionais , RNA Mensageiro/análise , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Taxa de Sobrevida
7.
J Cell Biol ; 150(5): 1199-208, 2000 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-10974006

RESUMO

The immunosuppressive and antiinflammatory actions of glucocorticoid hormones are mediated by their transrepression of activating protein-1 (AP-1) and nuclear factor-kappa B (NFkappaB) transcription factors. Inhibition of the c-Jun NH(2)-terminal kinase (JNK) signaling pathway, the main mediator of AP-1 activation, has been described in extracts of hormone-treated cells. Here, we show by confocal laser microscopy, enzymatic assays, and immunoblotting that the synthetic glucocorticoid dexamethasone inhibited tumor necrosis factor alpha (TNF-alpha)-induced phosphorylation and activation of JNK in the cytoplasm and nucleus of intact HeLa cells. As a result, c-Jun NH(2)-terminal domain phosphorylation and induction were impaired. Dexamethasone did not block the TNF-alpha-induced JNK nuclear translocation, but rather induced, per se, nuclear accumulation of the enzyme. Consistently with previous findings, a glucocorticoid receptor mutant (GRdim), which is deficient in dimerization, DNA binding, and transactivation, but retains AP-1 transrepressing activity, was as efficient as wild-type GR in mediating the same effects of dexamethasone on JNK in transfected Cos-7 cells. Our results show that glucocorticoids antagonize the TNF-alpha-induced activation of AP-1 by causing the accumulation of inactive JNK without affecting its subcellular distribution.


Assuntos
Núcleo Celular/metabolismo , Dexametasona/farmacologia , Glucocorticoides/farmacologia , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Fator de Transcrição AP-1/metabolismo , Animais , Células COS , Fracionamento Celular , Núcleo Celular/efeitos dos fármacos , Citosol/efeitos dos fármacos , Citosol/metabolismo , Ativação Enzimática , Células HeLa , Humanos , Proteínas Quinases JNK Ativadas por Mitógeno , Cinética , Proteínas Quinases Ativadas por Mitógeno/efeitos dos fármacos , Fosforilação , Proteínas Recombinantes/metabolismo , Transdução de Sinais/efeitos dos fármacos , Fator de Transcrição AP-1/antagonistas & inibidores , Transfecção , Fator de Necrose Tumoral alfa/farmacologia
9.
J Physiol Biochem ; 74(2): 325-334, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29577176

RESUMO

To assess the possible function of glutamate in the interaction between the dorsomedial hypothalamic nucleus-perifornical area (DMH-PeF) and the A5 pontine region (A5), cardiovascular and respiratory changes were studied in response to electrical stimulation of the DMH-PeF (1 ms pulses, 30-50 µA given at 100 Hz for 5 s) before and after the microinjection of kynurenic acid (non-specific glutamate receptor antagonist; 50 nl, 5 nmol), MK-801 (NMDA receptor antagonist; 50 nl, 50 nmol), CNQX (non-NMDA receptor antagonist; 50 nl, 50 nmol) or MCPG (metabotropic glutamate receptor antagonist; 50 nl, 5 nmol) within the A5 region. DMH-PeF electrical stimulation elicited a pressor (p < 0.001) and tachycardic response (p < 0.001) which was accompanied by an inspiratory facilitation characterised by an increase in respiratory rate (p < 0.001) due to a decrease in expiratory time (p < 0.01). Kynurenic acid within the A5 region decreased the tachycardia (p < 0.001) and the intensity of the blood pressure response (p < 0.001) to DMH-PeF stimulation. After the microinjection of MK-801 and CNQX into the A5 region, the magnitude of the tachycardia and the pressor response were decreased (p < 0.05 and p < 0.01; p < 0.001 and p < 0.05, respectively). After MCPG microinjection into the A5 region, a decrease in the tachycardia (p < 0.001) with no changes in the pressor response was observed during DMH-PeF stimulation. The respiratory response elicited by DMH-PeF stimulation was not changed after the microinjection of kynurenic acid, MK-801, CNQX or MCPG within the A5 region. These results suggest that A5 region glutamate receptors play a role in the cardiovascular response elicited from the DMH-PeF. The possible mechanisms involved in these interactions are discussed.


Assuntos
Fenômenos Fisiológicos Cardiovasculares , Núcleo Hipotalâmico Dorsomedial/fisiologia , Fórnice/fisiologia , Receptores de Glutamato/fisiologia , 6-Ciano-7-nitroquinoxalina-2,3-diona/administração & dosagem , Animais , Pressão Sanguínea , Maleato de Dizocilpina/administração & dosagem , Estimulação Elétrica , Antagonistas de Aminoácidos Excitatórios/administração & dosagem , Glicina/administração & dosagem , Glicina/análogos & derivados , Frequência Cardíaca , Ácido Cinurênico/administração & dosagem , Masculino , Microinjeções , Ratos , Taxa Respiratória , Taquicardia/fisiopatologia
10.
Clin Cancer Res ; 1(9): 1043-9, 1995 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9816078

RESUMO

We analyzed allelic loss at the p53 gene (17p13) and at chromosome region 9p21 in 35 primary head and neck squamous cell carcinomas. Loss of heterozygosity (LOH) at p53 and 9p21 was found in 50 and 75% of informative cases, respectively. LOH at the p53 gene did not increase significantly with tumor stage, but was more frequent in moderately and poorly differentiated tumors than in well-differentiated tumors. LOH plus mutation or homozygous deletion of p53 was limited to advanced stage and poorly differentiated tumors. Allelic loss at 9p21 is frequent in early stage head and neck squamous cell carcinoma and is not significantly associated with LOH at p53. The second exon of the p16/MTS1/CDKN2 gene was found to be homozygously deleted in 1 of 19 cases showing LOH at 9p21, but direct sequencing did not show mutations in the remaining 18 cases. This suggests that p16 plays a limited role in the development of head and neck squamous cell carcinoma.


Assuntos
Carcinoma de Células Escamosas/genética , Genes p16/genética , Genes p53/genética , Neoplasias de Cabeça e Pescoço/genética , Perda de Heterozigosidade , Cromossomos Humanos Par 17/genética , Cromossomos Humanos Par 9/genética , Análise Mutacional de DNA , Humanos , Repetições de Microssatélites
11.
FEBS Lett ; 459(2): 272-6, 1999 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-10518034

RESUMO

Glucocorticoid hormones, retinoids, and vitamin D3 display anti-angiogenic activity in tumor-bearing animals. However, despite their in vivo effect on the tumor vasculature little is known about their mechanism of action. Here we show that the synthetic glucocorticoid dexamethasone (Dex) and retinoic acid (RA) inhibit the activation of c-Jun N-terminal kinase (JNK) and extracellular-regulated kinase (ERK) signalling pathways by the pro-angiogenic agents tumor necrosis factor and vascular endothelial growth factor in endothelial cells. In contrast, Dex and RA failed to inhibit the activation of the p38 mitogen-activated protein kinase cascade. As a number of pro-angiogenic factors activate AP-1 transcription factor via the JNK and ERK pathways, our results suggest that the antagonism with AP-1 may underlie at least partially the anti-angiogenic effect of glucocorticoids and retinoids.


Assuntos
Endotélio Vascular/enzimologia , Hormônios/metabolismo , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Receptores Citoplasmáticos e Nucleares/metabolismo , Células Cultivadas , Dexametasona/farmacologia , Fatores de Crescimento Endotelial/metabolismo , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/metabolismo , Ativação Enzimática , Glucocorticoides/farmacologia , Humanos , Proteínas Quinases JNK Ativadas por Mitógeno , Linfocinas/metabolismo , Proteínas Quinases Ativadas por Mitógeno/antagonistas & inibidores , Receptores Citoplasmáticos e Nucleares/agonistas , Receptores Citoplasmáticos e Nucleares/biossíntese , Transdução de Sinais , Tretinoína/farmacologia , Fator de Necrose Tumoral alfa/metabolismo , Fator A de Crescimento do Endotélio Vascular , Fatores de Crescimento do Endotélio Vascular , Proteínas Quinases p38 Ativadas por Mitógeno
12.
J Clin Pathol ; 50(6): 509-12, 1997 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9378820

RESUMO

AIMS: To study the homozygous deletion and methylation status of the 5' CpG island of the p16 and p15 genes (9p21) in a set of primary advanced head and neck squamous cell carcinomas (SCC) and to test whether inactivation of these genes by these mechanisms contributes to head and neck SCC development. METHODS: DNA was extracted from fresh tumours. Homozygous deletion was determined by the polymerase chain reaction (PCR) followed by hybridisation with the corresponding probe, radioactively labelled by the random priming method. Methylation status of the CpG island of the 5' region of these genes was assessed by digestion with the appropriate restriction enzymes followed by PCR and subsequent hybridisation with the corresponding probe. The presence of point mutations was determined by PCR-SSCP (single strand conformation polymorphism). RESULTS: The p16 and p15 genes were homozygously deleted in 20% and 10% of the tumours, respectively. No point mutations were found at p16 and p15. The 5' CpG island at the p16 gene was methylated in 20% of the cases. CONCLUSIONS: The tumour suppressor gene p16 is inactivated through homozygous deletion or methylation in a significant proportion of cases of head and neck SCC.


Assuntos
Carcinoma de Células Escamosas/genética , Cromossomos Humanos Par 9/genética , Deleção de Genes , Genes Supressores de Tumor/genética , Neoplasias de Cabeça e Pescoço/genética , Metilação de DNA , Homozigoto , Humanos , Reação em Cadeia da Polimerase
13.
J Clin Pathol ; 51(7): 520-4, 1998 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9797729

RESUMO

AIMS: To study the loss of heterozygosity at the short arm of chromosome 3 in primary tumours from patients with squamous cell carcinoma of the head and neck; to determine whether the FHIT gene, mapped to 3p14.2 and the CTNNB1 (beta-cat) gene, mapped to 3p21, are deleted or mutated in these tumours. METHODS: DNA was extracted from fresh tumours. Loss of heterozygosity was assessed by microsatellite analysis of the following markers: D3S1283 and D3S1286 (3p24), D3S966 (3p21), and D3S1300 (3P14.2). Homozygous deletion was determined by radioactive multiplex polymerase chain reaction of exons 5 and 6 of the FHIT gene. The presence of mutations in FHIT exon 5 and beta-cat exon 3 was studied by single strand conformation polymorphism. RESULTS: 50% of informative cases (25/50) showed loss of heterozygosity for at least one of the 3p markers. 3p21 was the region with the highest rate of allelic deletion (63%). No point mutation was found in FHIT exon 5 or beta-cat exon 3. No case showed homozygous deletion for the FHIT (exons 5 and 6) or the beta-cat exon 3. CONCLUSIONS: The short arm of chromosome 3 is often deleted in the head and neck squamous cell carcinomas. In the remaining alleles of the FHIT or beta-cat genes, no evidence was found for point mutations or deletions, documented in other common carcinomas. Inactivation could occur by different mechanisms such as methylation, or other genes (not studied here) could be target of allelic losses in squamous cell carcinoma of the head and neck.


Assuntos
Carcinoma de Células Escamosas/genética , Cromossomos Humanos Par 3 , Neoplasias de Cabeça e Pescoço/genética , Perda de Heterozigosidade , Transativadores , Fragilidade Cromossômica , Proteínas do Citoesqueleto/genética , Análise Mutacional de DNA , Deleção de Genes , Humanos , Reação em Cadeia da Polimerase , Polimorfismo Conformacional de Fita Simples , beta Catenina
14.
J Clin Pathol ; 51(4): 294-8, 1998 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-9659241

RESUMO

AIMS: To analyse the allele frequencies of DNA polymorphisms at the genes for cytochromes P450IIE1 and P450IID6, N-acetyltransferase-2, and glutathione S-transferase-M1 in patients with head and neck squamous cell carcinoma, in an attempt to define genetic factors involved in the susceptibility to this cancer, which is strongly associated with tobacco consumption. METHODS: Determination of restriction fragment length polymorphism (RFLP) at cytochromes P450IIE1/P450IID6 and NAT2 genes, and the presence of homozygous deletion of the GSTM1 gene, in 200 controls and 75 head and neck cancer patients. Allelic frequencies between the two groups were compared using a chi 2 test, and odds ratio with 95% confidence intervals were calculated. RESULTS: There was no evidence of an association between alleles of CYP2D6 and CYP2E1 and head and neck cancer in our population. Similarly, frequencies of individuals lacking the GSTM1 gene did not differ between controls and patients. However, individuals with the NAT2-SA phenotype were at higher risk of developing head and neck cancer. The frequencies of the most common SA genotype (homozygous for the NAT2*5 allele) were higher in patients than in controls (27% v 15%, respectively). Slow acetylators homozygous for the NAT2*6 allele, the second most common SA allele, were also more common in patients than in controls (11% v 5%, respectively). CONCLUSIONS: Slow NAT2 activity is a risk factor possibly leading to the development of head and neck cancer in response to tobacco carcinogens.


Assuntos
Acetiltransferases/genética , Carcinoma de Células Escamosas/genética , Citocromo P-450 CYP2D6/genética , Citocromo P-450 CYP2E1/genética , Glutationa Transferase/genética , Neoplasias de Cabeça e Pescoço/genética , Proteínas de Neoplasias/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Consumo de Bebidas Alcoólicas/efeitos adversos , Carcinoma de Células Escamosas/enzimologia , Carcinoma de Células Escamosas/etiologia , Suscetibilidade a Doenças , Neoplasias de Cabeça e Pescoço/enzimologia , Neoplasias de Cabeça e Pescoço/etiologia , Humanos , Masculino , Pessoa de Meia-Idade , Polimorfismo Genético , Polimorfismo de Fragmento de Restrição , Fatores de Risco , Fumar/efeitos adversos
15.
J Clin Pathol ; 50(3): 212-7, 1997 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9155671

RESUMO

AIMS: To study the loss of heterozygosity and the presence of mutations at the p53, p16/CDKN2, and APC genes in Barrett's oesophagus, low grade dysplastic oesophageal epithelium, and adenocarcinoma of the oesophagus; to relate the presence of alterations at these genes with the progression from Barrett's oesophagus to adenocarcinoma. METHODS: DNA was extracted from paraffin blocks containing tissue from Barrett's oesophagus (12 samples), low grade dysplasia (15 cases), and adenocarcinoma (14 cases). Loss of heterozygosity (LOH) at the p53, p16, and APC genes was determined by comparing the autoradiographic patterns of several microsatellite markers between the normal tissue and the malignant tissue counterpart. SSCP was used to determine the presence of mutations at p53 (exons 5 to 8), p16 (exon 2), and APC. Homozygous deletion of the p16 gene was defined through polymerase chain reaction followed by Southern blot. RESULTS: LOH at the p53, p16, and APC genes was not observed in Barrett's oesophagus without dysplasia, and increased to 90% (p53), 89% (p16), and 60% (APC) in the adenocarcinomas. The p53 gene was mutated in only two adenocarcinomas (codons 175 and 245). In one case a mutation at the APC gene (codon 1297) was found. No patient had mutation at the second exon of p16. However, this gene was homozygously deleted in three of the 12 adenocarcinomas. CONCLUSIONS: The tumour suppressor genes p53, p16, and APC are often deleted in adenocarcinomas derived from Barrett's oesophagus. Mutations at these genes are also found in the adenocarcinomas, including the homozygous deletion of the p16 gene. However, the absence of genetic alterations in the Barrett's oesophagus and the low grade dysplastic epithelia suggest that mutations at these genes develop later in the progression from Barrett's oesophagus to adenocarcinoma.


Assuntos
Adenocarcinoma/genética , Esôfago de Barrett/genética , Neoplasias Esofágicas/genética , Genes Supressores de Tumor/genética , Esôfago de Barrett/patologia , Análise Mutacional de DNA , Progressão da Doença , Mutação da Fase de Leitura , Deleção de Genes , Genes APC/genética , Genes p53/genética , Heterozigoto , Humanos , Mutação Puntual , Análise de Sequência de DNA
16.
Brain Res ; 982(1): 108-18, 2003 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-12915245

RESUMO

We have examined the importance of the A5 region modulating cardiorespiratory responses evoked from the parabrachial complex (PB) in spontaneously breathing rats. Cardiorespiratory changes were analyzed in response to electrical stimulation and glutamate microinjections into the PB (10-20 nl, 1-2 nmol) before and after ipsilateral microinjection of muscimol (50 nl, 0.25 nmol) or lidocaine (50 nl, 0.5 nmol) within the A5 region. Stimulation of medial parabrachial and Kölliker-Fuse nuclei (mPB-KF) evoked a decrease in respiratory rate (P<0.001) with a rise in blood pressure (P<0.001) and heart rate (P<0.05). After muscimol or lidocaine microinjections within the A5 region, the pressor and heart rate responses to mPB-KF stimulation were reduced (P<0.05, both cases). Muscimol within the A5 region altered the respiratory response to glutamate stimulation of mPB-KF, evoking an increase in respiratory rate (P<0.05). Lidocaine abolished the respiratory response to mPB-KF stimulation. Stimulation of the lateral parabrachial nuclei (lPB) caused an increase in respiratory rate (P<0.001) with a rise in blood pressure (P<0.001) and heart rate (P<0.05). Muscimol or lidocaine microinjections within A5 region decreased heart rate (P<0.05) and pressor responses (P<0.05) evoked from lPB. The increase of respiratory rate persisted unchanged. To confirm functional interactions between A5 and PB, extracellular recordings of putative A5 neurones were obtained during PB stimulation. Eighty-three A5 cells were recorded, 35 were activated from the mPB-KF (42%). The results indicate that neurones of the A5 region participate in the cardiorespiratory response evoked from the different regions of the PB complex. The possible mechanisms involved in these interactions are discussed.


Assuntos
Coração/fisiologia , Ponte/fisiologia , Fenômenos Fisiológicos Respiratórios , Animais , Pressão Sanguínea/efeitos dos fármacos , Estimulação Elétrica , Potenciais Evocados , Frequência Cardíaca/efeitos dos fármacos , Lidocaína/administração & dosagem , Microinjeções , Muscimol/administração & dosagem , Neurônios/fisiologia , Ponte/citologia , Ratos , Ratos Sprague-Dawley , Respiração/efeitos dos fármacos
17.
Arch Med Res ; 28(3): 401-6, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9291639

RESUMO

The objective of this study was to assess the functional capacity for intracellular death (ID) and/or phagocytic index (PI) of polymorphonuclear cells of 24-h-old healthy newborns with respect to the PMN cells of adults using the same standard exogenous source of opsonins. The ID and PI techniques were standardized and 2-3 ml of blood were used. No differences were found in the percentages of ID, P, PI among the PMNs of the newborns and those of the adults: 43.95 +/- 15.70 vs. 44.56 +/- 8.43 for ID; 38.96 +/- 14.34 vs. 39.00 +/- 14.54 for P; 1.71 +/- 0.54 vs. 1.73 0.45 for PI, respectively. It was concluded that the PMNs of 24-h newborns have an ID, P, PI functionality comparable to adult PMNs; differences observed in PMN function in newborns may be due to humoral deficiencies (opsonins).


Assuntos
Recém-Nascido/sangue , Neutrófilos/fisiologia , Fagocitose/fisiologia , Adulto , Envelhecimento/sangue , Citotoxicidade Imunológica , Humanos , Recém-Nascido/imunologia , Neutrófilos/imunologia , Neutrófilos/microbiologia
18.
Chem Phys Lipids ; 89(2): 91-6, 1997 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-9369008

RESUMO

The boron trifluoride-methanol derivatization of methyl 9,12-octadecadienoate was studied. This methylene-interrupted diene was reacted with 50% BF3-MeOH for 15 h at 0-5 degrees C and the four monomethoxy and two dimethoxy derivatives thus obtained were analyzed by gas chromatography-mass spectrometry. The only dimethoxy adducts observed were characterized as methyl 9,12-dimethoxyoctadecanoate and methyl 10,13-dimethoxyoctadecanoate. The complete regiospecificity observed in the formation of the dimethoxy adducts is best explained by a common O-methyltetrahydrofuranium ion as the only intermediate under these reaction conditions.


Assuntos
Ácidos Graxos/química , Metano/análogos & derivados , Catálise , Cromatografia Gasosa-Espectrometria de Massas , Hidrocarbonetos , Concentração de Íons de Hidrogênio , Cinética , Metano/química
19.
Laryngoscope ; 111(7): 1297-301, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11568558

RESUMO

OBJECTIVE: Tumors arising from different sites of the head and neck area have different clinical behavior. However, most of the studies on genetic alterations in head and neck squamous cell carcinomas do not make a distinction between the sites within this area. The objective of this study is to compare the genetic alterations in three different sites of the head and neck (larynx, oropharynx, and hypopharynx). STUDY DESIGN: Prospective study. METHODS: Thirty-eight laryngeal, 29 oropharyngeal, and 37 hypopharyngeal carcinomas were studied. DNA from tumor and healthy tissue was evaluated for amplification of the oncogenes at 11q13 region (CCND1, FGF3, FGF4 and EMS1) and of the oncogenes MYC and ERBB1; for integration of the human papillomavirus (HPV) types 6b and 16; for loss of heterozygosity (LOH) at p53 and NAT2; and for the cellular DNA content. RESULTS: FGF3 and FGF4 showed a significantly higher frequency of amplification in hypopharyngeal tumors (P =.006 and P =.0002, respectively). CCND1 amplification had a nearly statistically significant (P =.072) higher frequency of amplification in hypopharyngeal tumors. Aneuploid tumors were found in a significantly lower proportion in the larynx (P =.03) compared with the other sites. For the other genetic alterations, no significant differences among the three sites were found. CONCLUSIONS: These results suggest that cancers originating from different sites in the head and neck may have different tumor biology. Therefore, they should be considered as different entities.


Assuntos
Carcinoma de Células Escamosas/genética , Neoplasias de Cabeça e Pescoço/genética , Aneuploidia , Carcinoma de Células Escamosas/patologia , DNA de Neoplasias/genética , Interpretação Estatística de Dados , Feminino , Citometria de Fluxo , Genes Supressores de Tumor/genética , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Neoplasias Hipofaríngeas/genética , Neoplasias Hipofaríngeas/patologia , Neoplasias Laríngeas/genética , Masculino , Pessoa de Meia-Idade , Técnicas de Amplificação de Ácido Nucleico , Oncogenes/genética , Neoplasias Orofaríngeas/genética , Neoplasias Orofaríngeas/patologia , Reação em Cadeia da Polimerase , Estudos Prospectivos
20.
J Chromatogr Sci ; 40(9): 523-8, 2002 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-12433116

RESUMO

Triazines are widely used herbicides that can be detected in the environment at trace level. A preconcentration step is necessary to determinate them before analysis. In this study, carbonaceous and polymeric adsorbents are compared with C18 for the solid-phase extraction of simazine, atrazine, and propazine in water samples in order to quantitate their levels by high-performance liquid chromatography using photodiode-array detection.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Herbicidas/análise , Espectrofotometria Ultravioleta/métodos , Triazinas , Poluentes Químicos da Água/análise
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