Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 40
Filtrar
1.
AIDS Behav ; 26(12): 3950-3962, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35776254

RESUMO

Adolescent girls and young women (AGYW) in sub-Saharan Africa may benefit from pre-exposure prophylaxis (PrEP), yet stigma may limit PrEP acceptance and continuation. We examined factors associated with PrEP use stigma among 307 participants of the EMPOWER trial (2016-2018), an unblinded randomized controlled trial among HIV-negative, AGYW, aged 16-24, in South Africa and Tanzania. The 6-item, brief-PrEP use stigma scale (B-PSS) had high internal reliability. At the end of the trial, 34.2% of study participants reported any PrEP use stigma. Three latent classes were observed, reflecting low (46.9%), medium (31.9%), and high (21.2%) reported PrEP use stigma. Disclosure of PrEP use to sexual partner and belief that PrEP prevents HIV were associated with less reported PrEP use stigma. Conversely, participants who reported fear and shame about people living with HIV were more likely to report PrEP use stigma. Our validated tool and findings will enable practitioners to identify AGYW at high risk of PrEP use stigma who may benefit from additional support.Pan African clinical trials registry PACTR202006754762723, 5 April 2020, retrospectively registered.


Assuntos
Fármacos Anti-HIV , Infecções por HIV , Profilaxia Pré-Exposição , Adolescente , Feminino , Humanos , Fármacos Anti-HIV/uso terapêutico , Infecções por HIV/epidemiologia , Infecções por HIV/prevenção & controle , Infecções por HIV/tratamento farmacológico , Prevalência , África do Sul/epidemiologia , Tanzânia/epidemiologia , Reprodutibilidade dos Testes , Fatores de Risco
2.
Sci Rep ; 11(1): 8176, 2021 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-33854183

RESUMO

The functional properties of cuprates are strongly determined by the doping state and carrier density. We present an oxygen doping study of YBa2Cu3O7-δ (YBCO) thin films from underdoped to overdoped state, correlating the measured charge carrier density, [Formula: see text], the hole doping, p, and the critical current density, [Formula: see text]. Our results show experimental demonstration of strong increase of [Formula: see text] with [Formula: see text], up to Quantum Critical Point (QCP), due to an increase of the superconducting condensation energy. The ultra-high [Formula: see text] achieved, 90 MA cm-2 at 5 K corresponds to about a fifth of the depairing current, i.e. a value among the highest ever reported in YBCO films. The overdoped regime is confirmed by a sudden increase of [Formula: see text], associated to the reconstruction of the Fermi-surface at the QCP. Overdoping YBCO opens a promising route to extend the current carrying capabilities of rare-earth barium copper oxide (REBCO) coated conductors for applications.

3.
Int J Tuberc Lung Dis ; 21(11): 87-96, 2017 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-29025490

RESUMO

Crucial to finding and treating the 4 million tuberculosis (TB) patients currently missed by national TB programmes, TB stigma is receiving well-deserved and long-delayed attention at the global level. However, the ability to measure and evaluate the success of TB stigma-reduction efforts is limited by the need for additional tools. At a 2016 TB stigma-measurement meeting held in The Hague, The Netherlands, stigma experts discussed and proposed a research agenda around four themes: 1) drivers: what are the main drivers and domains of TB stigma(s)?; 2) consequences: how consequential are TB stigmas and how are negative impacts most felt?; 3) burden: what is the global prevalence and distribution of TB stigma(s) and what explains any variation? 4): intervention: what can be done to reduce the extent and impact of TB stigma(s)? Each theme was further subdivided into research topics to be addressed to move the agenda forward. These include greater clarity on what causes TB stigmas to emerge and thrive, the difficulty of measuring the complexity of stigma, and the improbability of a universal stigma 'cure'. Nevertheless, these challenges should not hinder investments in the measurement and reduction of TB stigma. We believe it is time to focus on how, and not whether, the global community should measure and reduce TB stigma.


Assuntos
Conhecimentos, Atitudes e Prática em Saúde , Modelos Teóricos , Projetos de Pesquisa , Estigma Social , Tuberculose Pulmonar/psicologia , Humanos
4.
Phys Chem Chem Phys ; 19(21): 14129-14140, 2017 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-28524207

RESUMO

The kinetics of oxygen incorporation (in-diffusion process) and excorporation (out-diffusion process), in YBa2Cu3O6+x (YBCO) epitaxial thin films prepared using the chemical solution deposition (CSD) methodology by the trifluoroacetate route, was investigated by electrical conductivity relaxation measurements. We show that the oxygenation kinetics of YBCO films is limited by the surface exchange process of oxygen molecules prior to bulk diffusion into the films. The analysis of the temperature and oxygen partial pressure influence on the oxygenation kinetics has drawn a consistent picture of the oxygen surface exchange process enabling us to define the most likely rate determining step. We have also established a strategy to accelerate the oxygenation kinetics at low temperatures based on the catalytic influence of Ag coatings thus allowing us to decrease the oxygenation temperature in the YBCO thin films.

5.
Evol Dev ; 18(5-6): 324-341, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27696666

RESUMO

Wnt genes are a family of conserved glycoprotein ligands that play a role in a wide variety of cell and developmental processes, from cell proliferation to axis elongation. There are 13 Wnt subfamilies found among metazoans. Eleven of these appear conserved in arthropods with a pattern of loss during evolution of as many as six subfamilies among hexapods. Here we report on Wnt genes in the branchiopod crustacean, Thamnocephalus platyurus, including the first documentation of the expression of the complete Wnt gene family in a crustacean. Our results suggest fewer Wnt genes were retained in Thamnocephalus than in the related crustacean, Daphnia, although the Thamnocephalus Wnt repertoire is larger than that found in insects. We also find an intriguing pattern of staggered expression of Wnts-an anterior-posterior stagger within the posterior growth zone and a dorsal-ventral stagger in the developing segments-suggesting a potential for subfunctionalization of Wnts in these regions.


Assuntos
Anostraca/genética , Proteínas de Artrópodes/genética , Regulação da Expressão Gênica no Desenvolvimento , Proteínas Wnt/genética , Animais , Anostraca/embriologia , Proteínas de Artrópodes/metabolismo , Clonagem Molecular , DNA Complementar/genética , DNA Complementar/metabolismo , Evolução Molecular , Filogenia , Análise de Sequência de DNA , Proteínas Wnt/metabolismo
6.
Clin Lab ; 54(3-4): 81-7, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18630737

RESUMO

PURPOSE: Transient cardiac ventricular dysfunction or sudden cardiac deaths have been reported for male athletes participating in marathon racing. Less is known about the myocardial response in females. We examined natriuretic peptides and cardiac troponins in female athletes after a marathon. METHODS: At the 31st real,- Berlin Marathon plasma levels of NT-pro-BNP, BNP, cTnI and cTnT were measured in 15 women (age 35+/-6 years; finishing times between 3:22 h and 5:21 h) at four different time points (before, immediately after, day one and day three). RESULTS: An increase in [NT-pro-BNP] was observed immediately after the marathon (median [NT-pro-BNP] before: 39.6 pg ml(-1), after: 138.6 pg ml(-1), p=0.003) with a further increase on day one. [BNP] did not increase immediately after the marathon but increased on day one (median [BNP] before: 15 pg ml(-1), day one: 27.35 pg ml(-1), p=0.006). On day three, [NT-pro-BNP] and [BNP] returned to initial values. [cTnI] was under the detection limit prior to the marathon in all runners. [cTnT] was under the detection limit before the marathon except in one runner who presented a concentration of 0.03 ng ml(-1). Cardiac troponins (median [cTnl] after: 0.098 ng ml(-1), p=0.028; median [cTnT] after: 0.032 ng ml(-1), p=0.012) increased immediately after the marathon and returned to initial values on day one [cTnT] and three [cTnI]. DISCUSSION: Parameters representing cardiac stress increased in females after a marathon. Different kinetics of natriuretic peptides BNP and NT-pro-BNP post-marathon could be due to their different half-lives and dependence on renal function. The increase of cTnI and cTnT may result from minor myocardial lesions.


Assuntos
Biomarcadores/sangue , Fenômenos Fisiológicos Cardiovasculares , Peptídeo Natriurético Encefálico/sangue , Fragmentos de Peptídeos/sangue , Corrida/fisiologia , Troponina I/sangue , Troponina T/sangue , Adulto , Feminino , Humanos , Pessoa de Meia-Idade , Esforço Físico/fisiologia , Fatores de Tempo
7.
AIDS Care ; 19(5): 626-36, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17505923

RESUMO

We examined trends and predictors of quality of life (QOL) over 12 months among a prospective cohort of 947 HIV-1-infected adults initiating highly active antiretroviral therapy (HAART) between May 2003 and May 2004 in rural Uganda. Participants provided clinical, demographic and psychosocial data at baseline and every three months thereafter. Outcome measures included physical and mental health summary scores based on the Medical Outcomes Study-HIV Health Survey (MOS-HIV). Generalised estimating equations were used to assess magnitude of change in summary scores and factors associated with QOL. Of 710 women and 237 men enrolled, the mean age was 38.7 years and mean baseline CD4 cell count was 124.1 cells/microL. At enrollment, physical and mental health summary scores were 39.2 and 40, respectively. By 12 months of HAART, scores increased by 11.2 points (p <0.001) and 7.4 points (p <0.001), respectively. For both scores, most gains were achieved by the third month of therapy. While several clinical, psychosocial and sociodemographic factors predicted QOL at HAART initiation, financial dependence on others was the only remaining predictor after controlling for time on HAART. Interventions to enhance the economic and employment opportunities of patients taking HAART in rural Africa may help maximise gains in QOL.


Assuntos
Terapia Antirretroviral de Alta Atividade/psicologia , Infecções por HIV/tratamento farmacológico , Qualidade de Vida/psicologia , Adulto , Feminino , Previsões , Humanos , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Saúde da População Rural/estatística & dados numéricos , Fatores Socioeconômicos , Resultado do Tratamento , Uganda
8.
Clin Lab ; 52(9-10): 511-3, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-17078478

RESUMO

Erythropoietin (EPO) was studied in 13 female marathon runners before and up to 8 days after a competition marathon run. The median baseline control value was 13.7 U/l. No change in EPO concentration was found immediately (15 min.) and one day after the run. However, a median increase in EPO concentration (18.1 U/l) was found on day three post-exercise (p< 0.05). On day 8 no change was found compared to pre-exercise values. This late increase in EPO concentration would seem to be responsible for the well known increase of red blood cell mass in long distance runners.


Assuntos
Eritropoetina/sangue , Resistência Física/fisiologia , Corrida/fisiologia , Esportes/fisiologia , Adulto , Feminino , Humanos
9.
J Neuropathol Exp Neurol ; 59(6): 544-58, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10850867

RESUMO

Brain tumors pose a particular challenge to molecular oncology. Many different tumor entities develop in the nervous system and some of them appear to follow distinct pathogenic routes. Molecular genetic alterations have increasingly been reported in nervous system neoplasms. However, a considerable number of affected genes remain to be identified. We present here a comprehensive allelotype analysis of 466 nervous system tumors based on loss of heterozygosity (LOH) studies with 129 microsatellite markers that span the genome. Specific alterations of the EGFR, CDK4, CDKN2A, TP53, DMBT1, NF2, and PTEN genes were analyzed in addition. Our data point to several novel genetic loci associated with brain tumor development, demonstrate relationships between molecular changes and histopathological features, and further expand the concept of molecular tumor variants in neuro-oncology. This catalogue may provide a valuable framework for future studies to delineate molecular pathways in many types of human central nervous system tumors.


Assuntos
Alelos , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/diagnóstico , Neoplasias Encefálicas/patologia , Humanos , Perda de Heterozigosidade , Repetições de Microssatélites , Biologia Molecular/métodos , Mutação/genética , Análise de Sobrevida
11.
Brain Pathol ; 9(4): 645-50, 1999 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-10517503

RESUMO

Meningiomas are common intracranial and intraspinal tumors. They are treated primarily by surgical resection. Meningioma recurrence following surgery is frequent despite advances in microneurosurgery. However, it is not clear whether recurrent meningiomas, close or distant to the primary resection site, arise from incomplete resection, dissemination of tumor fragments or from independent tumor growth. In order to address the question of clonality in recurring meningiomas, we examined a series of five patients with a total of 14 tumors for X-chromosome inactivation in the tumor tissues. Four patients with a total of 11 meningiomas were informative for polymorphisms either in the PGK or the AR genes. All recurrent meningiomas were found to be clonal with respect to the primary lesions. This finding suggests a common molecular pathogenesis of primary meningioma and subsequent recurrences (p<0.01). In a sixth patient, we analyzed the NF2 gene for mutations in the primary and 5 recurrent meningiomas. All six lesions carried the identical NF2 mutation, strongly indicating a common origin for these tumors. We conclude that recurrent meningiomas usually arise from dissemination of tumor fragments, most likely at the time of the first surgical resection. Our data should alert to the potential of meningioma cells for seeding during surgical procedures.


Assuntos
Mecanismo Genético de Compensação de Dose , Neoplasias Meníngeas/genética , Meningioma/genética , Análise Mutacional de DNA , Feminino , Genes da Neurofibromatose 2/genética , Humanos , Imageamento por Ressonância Magnética , Mutação/genética , Recidiva Local de Neoplasia/genética , Fosfoglicerato Quinase/genética , Polimorfismo Conformacional de Fita Simples , Receptores Androgênicos/genética
12.
J Pathol ; 188(2): 168-73, 1999 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10398160

RESUMO

The MEN1 gene on chromosome 11q13 is mutated in patients afflicted with multiple endocrine neoplasia syndrome type 1 (MEN1). These patients develop endocrine tumours of the pancreas, the parathyroid, and the anterior pituitary. In order to determine the role of MEN1 in sporadic pituitary adenomas, 61 pituitary adenomas were analysed from patients without evidence of a familial tumour syndrome. Single strand conformation polymorphism (SSCP) analysis was performed for the entire coding sequence of MEN1. Fragments with aberrant migration patterns were sequenced bidirectionally. Only a single somatic mutation was detected in this series. In addition, several previously reported and three novel polymorphisms were observed. Loss of heterozygosity analysis with 12 polymorphic markers, however, identified 13 pituitary adenomas with allelic deletions on chromosome 11. Allelic losses occurred significantly more often in pituitary adenomas with hormone secretion than in non-functioning adenomas. These data suggest that MEN1 mutations are rare events in sporadic pituitary adenomas. However, the discrepancy of only 1/61 adenomas with MEN1 mutation but 13/61 (22 per cent) with allelic loss on chromosome 11 may suggest the presence of a yet unknown tumour suppressor gene, relevant to the pathogenesis of sporadic pituitary adenomas.


Assuntos
Adenoma/genética , Neoplasia Endócrina Múltipla/genética , Neoplasias Hipofisárias/genética , Cromossomos Humanos Par 11 , Primers do DNA , Deleção de Genes , Humanos , Perda de Heterozigosidade , Mutação , Polimorfismo Genético , Polimorfismo Conformacional de Fita Simples , Análise de Sequência de DNA
13.
J Biotechnol ; 64(2-3): 177-86, 1998 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-9821674

RESUMO

The acetoacetyl-CoA reductase and the polyhydroxyalkanoate (PHA) synthase from Ralstonia eutropha (formerly Alcaligenes eutrophus) were expressed in Escherichia coli, Klebsiella aerogenes, and PHA-negative mutants of R. eutropha and Pseudomonas putida. While expression in E. coli strains resulted in the accumulation of poly(3-hydroxybutyrate) [PHB], strains of R. eutropha, P. putida and K. aerogenes accumulated poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) [poly(3HB-co-3HHx)] when even chain fatty acids were provided as carbon source, and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) [poly(3HB-co-3HV)] when odd chain fatty acids were provided as carbon source. This suggests that fatty acid degradation can be directly accessed employing only the acetoacetyl-CoA reductase and the PHA synthase. This is also the first proof that the PHA synthase from R. eutropha can incorporate 3-hydroxyhexanoate (3HHx) into PHA and has, therefore, a broader substrate specificity than previously described.


Assuntos
Aciltransferases/metabolismo , Cupriavidus necator/enzimologia , Ácido 3-Hidroxibutírico/metabolismo , Oxirredutases do Álcool/metabolismo , Caproatos/metabolismo , Carbono/metabolismo , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/crescimento & desenvolvimento , Recombinação Genética
14.
Surg Neurol ; 50(1): 77-82, 1998 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9657497

RESUMO

BACKGROUND: Continuous external CSF drainage represents a well established procedure which has been improved by many technical contributions. We present our experience in a prospective study of 212 needle trephinations in 165 consecutive patients with a new screw fixation device. METHODS: The entire procedure is performed at the bedside under local anesthesia with a twist drill. The trephination needle is inserted into the self-tapping cannulated screw fixed to the skull. RESULTS: The mean operation time was 6 min, and the duration of ventricular drainage ranged from 2 h to 44 days. Ninety-one percent (N = 193) of ventricular needles in our series were placed at the first targeting attempt. ICP-monitoring and -therapy (88%) were the main indications for needle trephination in our study. During the study period we observed needle associated complications, such as intracerebral hemorrhages (N = 2, 1%) and infections (N = 17, 8%). CONCLUSIONS: Concerning infection, primary insufficient fixation, and general surgical handling, we found a clear learning curve during the course of our study. In spite of the initial problems at the time of introduction we have to emphasize the outstanding advantages of the new ventriculostomy device: It is a time-saving bedside procedure equipped with an optimum fixation device and it enables uncomplicated exchange of the needle in case of obstruction.


Assuntos
Agulhas , Ventriculostomia/instrumentação , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Encefalopatias/diagnóstico , Encefalopatias/terapia , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Tempo , Ventriculostomia/efeitos adversos , Ventriculostomia/métodos
15.
J Neuropathol Exp Neurol ; 56(10): 1098-104, 1997 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-9329453

RESUMO

The histogenesis of oligoastrocytomas remains controversial, with some data arguing similarity of oligoastrocytomas to astrocytic tumors, and other data suggesting closer relationships with oligodendroglial neoplasms. Since the molecular genetic changes in astrocytomas differ from those of oligodendrogliomas, we characterized 120 astrocytic and oligodendroglial tumors, including 38 oligoastrocytomas, for genetic alterations that occur disproportionately between astrocytomas and oligodendrogliomas, i.e. TP53 gene mutations and allelic loss of chromosomes 1p, 17p and 19q. As previously reported, TP53 mutations were common in astrocytic gliomas, occurring in approximately half of WHO grade II and III astrocytomas, but in only 5% of WHO grades II and III oligodendrogliomas. Allelic losses of chromosomes 1p and 19q, however, were common in oligodendrogliomas (41% and 63%), but less frequent in astrocytomas (9% and 35%). Oligoastrocytomas showed TP53 mutations in 12/38 (32%) cases and allelic losses of chromosomes 1p and 19q in 52% and 70%, respectively. Most importantly, TP53 mutations and allelic losses on chromosomes 1p and 19q were inversely correlated in oligoastrocytomas (p < 0.011 and p < 0.019). These data suggest the existence of two genetic subsets of oligoastrocytomas, one genetically related to astrocytomas and the other genetically related to oligodendrogliomas. Histologically, those oligoastrocytomas with TP53 mutations were more often astrocytoma-predominant, while those with chromosome 19q loss were more often oligodendroglioma-predominant.


Assuntos
Astrocitoma/genética , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Cromossomos Humanos Par 17 , Cromossomos Humanos Par 19 , Cromossomos Humanos Par 1 , Genes p53 , Glioma/genética , Perda de Heterozigosidade , Repetições de Microssatélites , Oligodendroglioma/genética , Mutação Puntual , Adulto , Substituição de Aminoácidos , Astrócitos/patologia , Astrocitoma/patologia , Neoplasias Encefálicas/sangue , Neoplasias Encefálicas/classificação , Mapeamento Cromossômico , DNA de Neoplasias/genética , Glioma/sangue , Glioma/classificação , Glioma/patologia , Humanos , Oligodendroglia/patologia , Oligodendroglioma/patologia , Proteína Supressora de Tumor p53/química , Proteína Supressora de Tumor p53/genética
16.
J Neurosurg ; 86(5): 853-8, 1997 May.
Artigo em Inglês | MEDLINE | ID: mdl-9126902

RESUMO

A significant number of patients with meningiomas develop multiple tumors without anatomical bridges. To understand the mechanism by which multiple meningiomas arise, the authors analyzed DNA from 39 multiple meningiomas in 12 patients to locate alterations in the neurofibromatosis type 2 (NF2) gene. This gene has been shown to be inactivated in meningiomas. No patient in our series had a family history of meningiomas or NF2. All tumors were investigated by single-strand conformation polymorphism analysis of the entire coding region of the NF2 gene and by direct DNA sequencing of altered fragments. The DNA from meningiomas in 10 patients carried NF2 gene mutations. In six of the 10 patients with NF2 mutations, all tumors in the respective individual exhibited the identical DNA alteration in the NF2 gene, thus indicating clonal origin. All four patients with more than two lesions had clonal meningiomas and four patients with two meningiomas each carried different mutations in their tumors. Analysis of constitutional DNA revealed a wild-type NF2 sequence in all 12 patients, thus excluding a forme fruste of NF2 in these cases. Our data demonstrate that the majority of multiple meningiomas with NF2 gene mutations are of somatic and clonal origin. Spread of tumor cells via the cerebrospinal fluid is the most likely mechanism to account for the development of these multiple meningiomas.


Assuntos
Genes da Neurofibromatose 2 , Neoplasias Meníngeas/genética , Meningioma/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Sequência de Bases , Cromossomos Humanos Par 22 , Éxons , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Neoplasias Meníngeas/diagnóstico , Neoplasias Meníngeas/patologia , Meningioma/diagnóstico , Meningioma/patologia , Pessoa de Meia-Idade , Biologia Molecular , Mutação , Polimorfismo Conformacional de Fita Simples , Tomografia Computadorizada por Raios X
17.
J Neurosurg ; 85(2): 263-71, 1996 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-8755755

RESUMO

Intrinsic insular tumors are frequently excluded from surgical treatment. The authors propose a more extensive approach to these lesions based on the results of this prospective series. From September 1993 to January 1995, 30 patients (18 males and 12 females; mean age 42 years) harboring benign (15 patients) or malignant (15 patients) tumors involving the insula underwent surgical treatment. The dominant and nondominant hemispheres were both affected in 15 cases. Two groups were defined on the basis of preoperative magnetic resonance (MR) imaging: 14 lesions were restricted to the insula and the corresponding opercula; the other 16 lesions also involved other mesocortical and/or allocortical areas. Most patients displayed only mild preoperative symptoms. The median score according to the Karnofsky performance scale was 90. Microsurgical removal was achieved via a transsylvian approach in nine cases and via a frontal and/or temporal approach in 21 cases. According to early postoperative MR imaging, complete tumor removal (100%) was seen in five patients, nearly complete (> 80%) in 21, and incomplete resection (50%-80%) in four patients. There was no operative mortality; 19 patients (63%) experienced immediate postoperative morbidity, including reduced performance. After a mean follow-up review of 8.5 months two of 21 patients suffered permanent deficits, accounting for an overall operative morbidity of 10%. At the mean time of review, three patients with Grade IV tumors had died of tumor recurrence. The authors conclude that low-grade intrinsic insular tumors, as well as Grade III tumors, can be removed with favorable results in the majority of patients. Surgery to excise glioblastomas should only be considered for patients with good preoperative performance and young age.


Assuntos
Neoplasias Encefálicas/cirurgia , Córtex Cerebral , Adulto , Idoso , Neoplasias Encefálicas/diagnóstico , Neoplasias Encefálicas/patologia , Criança , Pré-Escolar , Feminino , Seguimentos , Humanos , Imageamento por Ressonância Magnética , Masculino , Microcirurgia , Pessoa de Meia-Idade , Sistema Nervoso/fisiopatologia , Complicações Pós-Operatórias , Período Pós-Operatório , Estudos Prospectivos , Resultado do Tratamento
18.
Virology ; 219(1): 237-46, 1996 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-8623534

RESUMO

The onset of DNA replication is an important step within the life cycle of the human neurotropic polyomavirus JC. In this report, evidence that both the human and the murine tumor suppressor protein p53 strongly inhibit JCV DNA replication in vivo is presented. This inhibition is dose-dependent and not a secondary effect of a decreased expression of JCV large T-antigen in response to p53. Using deletion mutants of murine p53 and tumor-derived point mutations of human p53, the basis of the suppression of JCV DNA replication by p53 was dissected. Deletion of either the amino- or the carboxy-terminal domain of murine p53 did not interfere with the repression of JCV DNA replication. However, deletion of the highly conserved central region of p53 abolished the inhibitory effect on replication. The tumor-derived human mutant p53(His273) inhibited JCV DNA replication significantly, whereas another tumorigenic mutant, p53(His175), had no inhibitory effect Concomitantly, a direct protein-protein interaction between p53 and JCV large T-antigen was lost in mutants which did not affect JCV DNA replication. These results strongly suggest that p53 inhibits JCV DNA replication by interacting with JCV large T-antigen.


Assuntos
Antígenos Transformantes de Poliomavirus/imunologia , DNA Viral/biossíntese , Vírus JC/genética , Proteína Supressora de Tumor p53/fisiologia , Animais , Antígenos Transformantes de Poliomavirus/genética , Sequência de Bases , Sítios de Ligação , DNA Complementar , Humanos , Vírus JC/imunologia , Vírus JC/fisiologia , Camundongos , Dados de Sequência Molecular , Deleção de Sequência , Spodoptera/citologia , Células Tumorais Cultivadas , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/imunologia , Replicação Viral
19.
Oncogene ; 12(5): 973-8, 1996 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-8649814

RESUMO

Loss of heterozygosity (LOH) studies have emerged as a valuable indicator for tumor suppressor genes involved in the formation or progression of carcinomas. We here present data indicating that human chromosome 15 harbours a novel putative tumor suppressor gene which appears to play a role during later stages of carcinogenesis and which may be associated with metastasis in breast cancer. In this study, 153 primary and metastatic carcinomas from 101 patients have been analysed for LOH with 13 polymorphic microsatellite markers on chromosome 15. The tumors included carcinoma of the lung in 49 patients, breast carcinoma in 29, colorectal carcinoma in nine, renal carcinoma in five, pancreatic carcinoma in five, urinary bladder carcinoma in two and prostate carcinoma and ovarial carcinoma in one patient each. LOH15 was seen in 42/99 (42%) informative patients. In metastatic tumors, LOH15 was observed in 37/68 (54%). High incidences of allelic losses were detected in metastases from lung (56%), breast (70%) and colorectal (67%) carcinomas. In carcinomas of the breast, there was a significant difference (P<0.01) in LOH15 frequencies between non-metastatic tumors (11%) and brain metastases (70%). Such a difference was not observed on the chromosomal arm 17p which yielded high proportions of LOH in both non metastatic breast tumor (73%) and breast carcinoma metastases (90%). In 16 patients, interstitial deletions could be detected. The common region of overlap extended from D15S231 to D15S641, thus mapping this putative tumor suppressor gene to chromosome 15q14. Our data indicate that a gene on chromosome 15 contributes to the pathogenesis of metastatic carcinoma.


Assuntos
Neoplasias Encefálicas/genética , Neoplasias Encefálicas/secundário , Neoplasias da Mama/genética , Mapeamento Cromossômico , Cromossomos Humanos Par 15/genética , Deleção de Genes , Genes Supressores de Tumor , Neoplasias da Mama/patologia , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/secundário , Carcinoma de Células Pequenas/genética , Carcinoma de Células Pequenas/secundário , Neoplasias Colorretais/genética , Feminino , Humanos , Neoplasias Pulmonares/genética , Masculino
20.
Br J Pharmacol ; 116(2): 1769-74, 1995 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8528558

RESUMO

1. The present study attempted to determine whether noradrenaline (NA) release in rabbit hippocampus and human neocortex is modulated by presynaptic 5-hydroxytryptamine (5-HT) receptors. 2. Slices of rabbit hippocampus and human neocortex, loaded with [3H]-noradrenaline ([3H]-NA) were superfused and the effects of 5-hydroxytryptamine (5-HT) receptor ligands on electrically evoked [3H]-NA release were investigated. 3. In rabbit hippocampus, 5-HT, 5-carboxamidotryptamine (5-CT; 32 microM) and 2-CH3-5-HT (32 microM) increased [3H]-NA release elicited with 360 pulses/3 Hz. Facilitation of transmitter release was not influenced by the 5-HT3 receptor antagonist, tropisetron but was prevented by the alpha 2-adrenoceptor antagonist, rauwolscine. When autoinhibition was avoided by stimulating the tissue with 4 pulses/100 Hz (pseudo-one pulse-(POP) stimulation), 2-CH3-5-HT decreased evoked transmitter release, whereas 5-HT and 5-CT had no effect. Inhibition caused by 2-CH3-5-HT was not affected by tropisetron but counteracted by the alpha 2-adrenoceptor ligands, clonidine and rauwolscine. Inhibition caused by clonidine was diminished in the presence of 5-CT or 2-CH3-5-HT. 4. In human neocortex, [3H]-NA release elicited with 360 pulses/3 Hz was increased by 10 microM 5-HT and 32 microM 5-CT, whereas 2-CH3-5-HT was ineffective. [3H]-NA release evoked with a modified POP stimulation (2 bursts of 4 pulses/100 Hz, 3.5 min apart) was not affected by 2-CH3-5-HT or 5-CT. 5. The present results indicate that 5-HT, 2-CH3-5-HT and 5-CT can act on presynaptic alpha 2-autoreceptors as partial agonists (2-CH3-5-HT; in rabbit hippocampal tissue) or antagonists (5-HT and 5-CT; in tissue of rabbit hippocampus and human neocortex). Furthermore the existence of autoinhibition dictates whether these drugs cause facilitation of release, inhibition or have no effect.


Assuntos
Córtex Cerebral/efeitos dos fármacos , Hipocampo/efeitos dos fármacos , Norepinefrina/metabolismo , Receptores de Serotonina/efeitos dos fármacos , Agonistas do Receptor de Serotonina/farmacologia , Serotonina/análogos & derivados , Serotonina/farmacologia , Distribuição por Idade , Animais , Relação Dose-Resposta a Droga , Humanos , Coelhos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...