Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 21
Filtrar
1.
Nat Commun ; 14(1): 386, 2023 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-36693825

RESUMO

Ultrafast optical-domain spectroscopies allow to monitor in real time the motion of nuclei in molecules. Achieving element-selectivity had to await the advent of time resolved X-ray spectroscopy, which is now commonly carried at X-ray free electron lasers. However, detecting light element that are commonly encountered in organic molecules, remained elusive due to the need to work under vacuum. Here, we present an impulsive stimulated Raman scattering (ISRS) pump/carbon K-edge absorption probe investigation, which allowed observation of the low-frequency vibrational modes involving specific selected carbon atoms in the Ibuprofen RS dimer. Remarkably, by controlling the probe light polarization we can preferentially access the enantiomer of the dimer to which the carbon atoms belong.

2.
Andrology ; 6(2): 325-334, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29378089

RESUMO

Membrane cholesterol removal appears a key step for the gain of fertility potential during sperm maturation. However, the membrane sterol pattern in sperm cells from infertile patients, with impaired sperm parameters, has been poorly investigated. To elucidate a causative link between sperm membrane composition in male fertility, here we have investigated the levels of cholesterol and its oxidized derivatives 7ß-hydroxycholesterol and 7-keto-cholesterol in sixteen infertile patients with oligo-asthenozoospermia and 16 normozoospermic (N) fertile subjects. Furthermore, ten of 16 N fertile subjects agreed to receive a defined testicular thermal challenge by adhering to a programme of sauna sessions for 1 month. Semen samples were obtained from each of the participants, and sperm parameters were assessed according to the World Health Organization criteria. Sperm levels of cholesterol, 7ß-hydroxycholesterol and 7-keto-cholesterol were quantified by ultra-pressure liquid chromatography mass spectrometry. The results showed that oligo-asthenozoospermia patients had a huge amount of cholesterol content compared with fertile subjects (12.40 ± 6.05 µg/106 cells vs. 0.45 ± 0.28 µg/106 cells, p < 0.001, N and oligo-asthenozoospermia, respectively). Also, oxidized derivatives were significantly higher in oligo-asthenozoospermia patients (7ß-hydroxycholesterol: 1.96 ± 1.03 ng/106 cells vs. 0.075 ± 0.05 ng/106 cells, p < 0.001 and 7-keto-cholesterol: 1.11 ± 0.72 ng/106 cells vs. 0.005 ± 0.003 ng/106 cells, p < 0.001). Moreover, sauna exposure, in parallel with a progressive worsening of sperm motility parameters, was associated with a reversible increase in sperm cholesterol after the third and fourth week of treatment, whilst 7ß-hydroxycholesterol and 7-keto-cholesterol levels showed an earlier enhancement starting from the second week. Our data show for the first time in humans a strong difference in the cholesterol and its oxidized derivatives of infertile and fertile subjects. These findings suggest a strict biochemical link relating testis function, sperm membrane status and male fertility potential.


Assuntos
Membrana Celular/metabolismo , Colesterol/metabolismo , Infertilidade Masculina/fisiopatologia , Espermatozoides , Adulto , Ciclodextrinas/farmacologia , Humanos , Masculino , Oxisteróis/metabolismo , Fosfolipídeos/metabolismo , Espermatozoides/efeitos dos fármacos , Banho a Vapor , Testículo/metabolismo
3.
J Nanosci Nanotechnol ; 12(11): 8573-9, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23421246

RESUMO

The ion-exchange process is widely used to dope silicate glass layers with silver, aimed at controlling the Ag state in view of possible applications, ranging from light waveguide fabrication to nanostructured composite glass synthesis. The silver doped glass structure as well as its prescribed properties depend on both the preparation parameters and the subsequent treatments. Several structural aspects are still open with regard either to the modification of the glass incorporating the dopant, or to clustering phenomena silver undergoes as a function of its local concentration and state, which are in turn strongly dependent on the preparation route. Systematic characterizations of these systems are mandatory to address the role of the various synthesis parameters in giving rise to the observed features, thus pointing out the effective methodologies for the fabrication of silicate glass layers with the desired properties. In this work, the results of micro-Raman, optical absorption and photoluminescence characterizations are presented for soda-lime glass slides doped with silver by Ag(+)-Na+ exchange and subsequent thermal treatments in air. In particular, a cross-section profiling analysis by Raman micro-spectroscopy was performed on Ag ion-exchanged samples after treatment at some different temperatures. The experimental findings allow to elucidate the role of the treatment temperature in the clustering process related to the local Ag concentration inside the exchanged glass layer.


Assuntos
Vidro/química , Nanopartículas Metálicas/química , Nanopartículas Metálicas/ultraestrutura , Microscopia/métodos , Prata/química , Análise Espectral Raman/métodos , Íons , Teste de Materiais
4.
Lipids ; 46(7): 659-67, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21574019

RESUMO

In the last 20 years increasing interest has been devoted to the investigation of white adipose tissue (WAT) because hypo- or hyperfunction of WAT is involved in the pathogenesis of obesity and other pathologies. The investigation and discrimination of different characteristics in adipose tissues by means of spectroscopic techniques appears as a topic of current interest, also in view of possible medical-technological applications. The aim of this work was to establish micro-Raman spectroscopy as a tool for the characterization of mammals fat tissue. After preliminary tests aimed at defining a suitable sample preparation protocol, Raman spectra of WAT specimens excised from mice of different ages were recorded in the energy range 750-3,350 cm⁻¹. Quantitative values of the unsaturation index were obtained through the calibration with HR-NMR spectra of lipid extracts. Raman spectroscopy detected a sharp increase in the unsaturation index between 22 and 30 days of age in close correspondence with the weaning of mice (21 days). The present results show that Raman spectroscopy is an inexpensive, fast and robust technique to analyze the unsaturation index of mammals fat tissues that could be routinely used in bioptic samples.


Assuntos
Tecido Adiposo Branco/química , Tecido Adiposo/química , Ácidos Graxos Insaturados/análise , Análise Espectral Raman/instrumentação , Triglicerídeos/análise , Animais , Espectroscopia de Ressonância Magnética/instrumentação , Masculino , Camundongos
5.
Nanotechnology ; 21(17): 175703, 2010 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-20368677

RESUMO

Nanocrystalline Lu(3)Ga(5)O(12), with average particle sizes of 40 nm, doped with a wide variety of luminescent trivalent lanthanide ions have been prepared using a sol-gel technique. The structural and morphological properties of the powders have been investigated by x-ray powder diffraction, high resolution transmission electron microscopy and Raman spectroscopy. Structural data have been refined and are presented for Pr(3+), Eu(3+), Gd(3+), Ho(3+), Er(3+) and Tm(3+) dopants, while room temperature excited luminescence spectra and emission decay curves of Eu(3+)-, Tm(3+)- and Ho(3+)-doped Lu(3)Ga(5)O(12) nanocrystals have been measured and are discussed. The Eu(3+) emission spectrum shows typical bands due to 5D(0)-->7F(J) (J = 0, 1, 2, 3, 4) transitions and the broadening of these emission bands with the non-exponential behaviour of the decay curves indicates the presence of structural disorder around the lanthanide ions. Lanthanide-doped nanocrystalline Lu(3)Ga(5)O(12) materials show better luminescence intensities compared to Y(2)O(3), Gd(3)Ga(5)O(12) and Y(3)Al(5)O(12) nanocrystalline hosts. Moreover, the upconversion emission intensity in the blue-green region for the Tm(3+)- and Ho(3+)-doped samples shows a significant increase upon 647.5 nm excitation with respect to other common oxide hosts doped with the same lanthanide ions.

6.
J Clin Oncol ; 21(9): 1698-707, 2003 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-12721244

RESUMO

PURPOSE: Familial adenomatous polyposis (FAP), caused by a mutation in the APC gene, is a colorectal cancer predisposition syndrome associated with several other clinical conditions. The severity of the FAP is related to the position of the inherited mutation in the APC gene. We analyzed a large series of FAP patients to identify associations among major clinical manifestations and to correlate the mutation site with specific disease manifestations. MATERIALS AND METHODS: APC mutations were identified in 953 FAP patients from 187 families. We used unconditional logistic regression models and a method involving generalized estimating equations to investigate the association between genotype and phenotype. We used multiple correspondence analysis to represent the interrelationships of a multiway contingency table of the considered variables. RESULTS: APC germline mutations were located between codons 156 and 2011 of the APC gene. Mutations spanning the region between codons 543 and 1309 were variable, but strongly associated with congenital hypertrophy of retinal pigment epithelium. Mutations between codons 1310 and 2011 were associated with a six-fold risk of desmoid tumors relative to the low-risk reference region (159 to 495). Mutations at codon 1309 were associated with early development of colorectal cancer. Mutations between codons 976 and 1067 were associated with a three- to four-fold increased risk of duodenal adenomas. The cumulative frequency of extracolonic manifestations was highest for mutations between codons 976 and 1067, followed by mutations between 1310 and 2011. CONCLUSION: Analysis of the relation between APC mutation site and phenotype identifies subgroups of FAP patients at high risk for major extracolonic disease, which is useful for surveillance and prevention.


Assuntos
Adenoma/genética , Polipose Adenomatosa do Colo/genética , Polipose Adenomatosa do Colo/patologia , Neoplasias Colorretais/genética , Análise Mutacional de DNA , Neoplasias Duodenais/genética , Genes APC , Predisposição Genética para Doença , Sistema de Registros , Adenoma/etiologia , Adolescente , Adulto , Idoso , Códon , Neoplasias Colorretais/etiologia , Neoplasias Duodenais/etiologia , Feminino , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Fenótipo , Estudos Retrospectivos , Fatores de Risco , Índice de Gravidade de Doença
7.
Int J Cancer ; 95(2): 102-7, 2001 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-11241320

RESUMO

Desmoids represent the most important cause of death, after colorectal cancer, in patients affected with familial adenomatous polyposis (FAP), an inherited disease due to mutations in the APC gene. The aims of our study were to estimate the risk of developing desmoids in FAP patients and to evaluate the association between desmoids and different risk factors. The occurrence of desmoids, colorectal cancer and other extra-colonic manifestations were assessed in 897 FAP patients, 653 of whom were also investigated for APC mutations. Odds ratios (OR) and corresponding 95% confidence intervals (CI) were computed using an unconditional multiple logistic regression model. Desmoids developed in 107 patients (11.9%), with a cumulative risk of 20.6%. Females had a significantly higher risk than males (OR = 2.1; 95% CI 1.4-3.1). Family history of desmoids (OR = 8.75; 95% CI 5.66-13.51), osteomas (OR = 2.9; 95% CI 1.8-4.8) and epidermoid cysts (OR = 1.8; 95% CI 1.1-3.2) was also significantly associated with the occurrence of disease. Subjects with APC mutations beyond codon 1444 had a 12-fold increased risk, compared with patients with mutations located upstream. Mutations beyond codon 1309 conferred a 17-fold higher risk, compared with mutations upstream codon 452. Multivariate analysis identified as independent predictors mutation beyond codon 1444 (OR = 6.2; 95% CI 2.5-15.8), family history of desmoids (OR = 5.8; 95% CI 3.1-10.6), female gender (OR = 2.1; 95% CI 1.1-3.8) and the presence of osteomas (OR = 1.9; 95% CI 1.1-3.4). Our results indicate that integrating genetic and clinical data is helpful in defining subgroups of patients at higher risk for desmoids, who may benefit from specific prevention programs.


Assuntos
Polipose Adenomatosa do Colo/complicações , Polipose Adenomatosa do Colo/diagnóstico , Polipose Adenomatosa do Colo/genética , Fibromatose Abdominal/diagnóstico , Fibromatose Abdominal/genética , Fibromatose Agressiva/diagnóstico , Fibromatose Agressiva/genética , Polipose Adenomatosa do Colo/cirurgia , Proteína da Polipose Adenomatosa do Colo , Adolescente , Adulto , Fatores Etários , Idade de Início , Idoso , Criança , Pré-Escolar , Neoplasias Colorretais/diagnóstico , Neoplasias Colorretais/genética , Intervalos de Confiança , Proteínas do Citoesqueleto/genética , Cisto Epidérmico/diagnóstico , Cisto Epidérmico/genética , Saúde da Família , Feminino , Seguimentos , Genótipo , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Mutação , Razão de Chances , Osteoma/diagnóstico , Osteoma/genética , Fenótipo , Polimorfismo Conformacional de Fita Simples , Sistema de Registros , Fatores de Risco , Fatores Sexuais , Fatores de Tempo
8.
Obstet Gynecol ; 96(3): 395-9, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10960632

RESUMO

OBJECTIVE: To evaluate nitric oxide (NO) production in patients with pregnancy-induced hypertension or preeclampsia and in controls. METHODS: Four groups of pregnant women were included: 17 patients with pregnancy-induced hypertension, ten with mild or moderate preeclampsia, 17 with severe preeclampsia, and 44 normotensive women matched for weeks of gestation at blood sampling with the cases. Plasma levels of L-citrulline and L-arginine were measured by using high-performance liquid chromatography. RESULTS: The mean plasma levels of L-citrulline and the ratio of L-citrulline to L-arginine, which reflects NO production, were higher in women with severe preeclampsia than in controls, patients with pregnancy-induced hypertension, and patients with mild or moderate preeclampsia. CONCLUSION: Nitric oxide production is enhanced in severe preeclampsia, possibly as a compensatory phenomenon for the increased synthesis and release of vasoconstrictors and platelet-aggregating agents.


Assuntos
Arginina/sangue , Citrulina/sangue , Pré-Eclâmpsia/diagnóstico , Adulto , Peso ao Nascer , Cromatografia Líquida de Alta Pressão , Feminino , Idade Gestacional , Humanos , Recém-Nascido , Óxido Nítrico/sangue , Pré-Eclâmpsia/sangue , Gravidez , Resultado da Gravidez , Valores de Referência
9.
Hum Mutat ; 13(2): 116-23, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10094547

RESUMO

Germline mutations in the APC gene are responsible for familial adenomatous polyposis (FAP), a dominantly inherited syndrome characterized by the development of hundreds to thousands of polyps in the colon and in the rectum of affected individuals and by variable extracolonic manifestations (gastric and duodenal polyps, osteomas, retinal lesions, and desmoid tumors). Through the combined use of single-strand conformation polymorphism (SSCP) analysis and the protein truncation test (PTT), we have screened 66 Italian FAP patients and found 29 different APC mutations in a total of 34 cases. Of the identified mutations, 15 were nonsense, 12 were 1- to 5-bp deletions or insertions and two were complex rearrangements, all leading to the formation of premature stop codons. Only 10 mutations had been already previously described at the germline level, confirming the high heterogeneity of the APC mutational spectrum. The mean age of diagnosis in mutation positive cases and their affected relatives was significantly lower than in cases without identified mutation (30.6 vs 39.1 years, respectively; p = 0.003). In addition, among patients without a family history of polyposis, all mutation-positive cases displayed at least one of the extracolonic manifestations usually associated with FAP, whereas in one-half of the cases without identified mutation, none of these phenotypes was observed. Although a fraction of apparently mutation-negative cases were likely to be due to limitations of the mutation screening strategy, our results suggest, in agreement with previous reports, that allelic and/or genetic heterogeneity might be responsible for the phenotypic variability observed in FAP patients.


Assuntos
Polipose Adenomatosa do Colo/genética , Proteínas do Citoesqueleto/genética , Testes Genéticos , Mutação em Linhagem Germinativa/genética , Proteína da Polipose Adenomatosa do Colo , Adolescente , Adulto , Pré-Escolar , Éxons/genética , Feminino , Genótipo , Humanos , Itália , Masculino , Pessoa de Meia-Idade , Fenótipo
10.
Obstet Gynecol ; 92(6): 1005-11, 1998 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9840567

RESUMO

OBJECTIVE: To assess the benefit of uterine artery Doppler ultrasound examination with ambulatory 24-hour blood pressure (BP) monitoring as a two-stage screening test for women at risk for pregnancy-induced hypertension, preeclampsia, or fetal growth restriction (FGR). METHODS: Uterine artery Doppler ultrasound was performed at 20-22 weeks' gestation on women at risk for pregnancy-induced hypertension, preeclampsia or FGR who were referred to our antenatal clinics. Abnormal findings were rechecked at 24 weeks' gestation. We selected 180 subjects (90 with abnormal uterine Doppler and 90 with normal uterine Doppler) for 24-hour BP monitoring with a portable automated device, immediately after recruitment, and the midline estimating statistics of rhythm of systolic and diastolic BPs were calculated. RESULTS: The highest incidence of pregnancy-induced hypertension and preeclampsia, with or without FGR, occurred in patients with abnormal uterine Doppler and a systolic midline estimating statistic of rhythm of at least 111 mmHg or a diastolic midline estimating statistic of rhythm of at least 68 mmHg. The specificity and positive predictive value of abnormal uterine Doppler ultrasound alone were low (55 and 27%, respectively), whereas the association of abnormal Doppler ultrasound with both systolic and diastolic midline estimating statistics of rhythm equal or above the selected cutoff values increased the specificity and positive predictive value to 93 and 63%, respectively. CONCLUSION: In clinical practice, a first-stage test with uterine artery Doppler ultrasound at 20-24 weeks' gestation, followed by a second-stage test with ambulatory 24-hour BP monitoring in patients with abnormal uterine Doppler, might indicate women at risk of developing pregnancy-induced hypertension or preeclampsia.


Assuntos
Monitorização Ambulatorial da Pressão Arterial , Retardo do Crescimento Fetal/diagnóstico por imagem , Hipertensão/diagnóstico , Pré-Eclâmpsia/diagnóstico , Complicações Cardiovasculares na Gravidez/diagnóstico , Ultrassonografia Doppler , Ultrassonografia Pré-Natal , Adulto , Protocolos Clínicos , Feminino , Humanos , Valor Preditivo dos Testes , Gravidez , Fatores de Risco
11.
Br J Cancer ; 78(5): 582-7, 1998 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9744495

RESUMO

Desmoids are locally aggressive, non-metastasizing soft-tissue tumours, whose aetiology is still unclear. In patients affected with familial adenomatous polyposis (FAP), the incidence of desmoids is much higher than in the general population. The APC gene, which is responsible for FAP, is involved in the development of desmoids associated with this syndrome. In this study 16 sporadic and four FAP-related desmoids were analysed in order to investigate the possible involvement of APC in non-syndromic cases also. The 5' end (exons 1-11) and the coding portion of exon 15 of APC were screened using the in vitro synthesized-protein assay (IVSP). Exons 5, 6, 8-14, and a region of exon 15 spanning codons 1036-1634 were investigated by single-strand conformation polymorphism (SSCP) analysis. APC germline mutations were identified in all FAP patients, but not in sporadic cases. Somatic mutations were found in three FAP-associated desmoids (75%) and two sporadic tumours (12.5%). In one of the latter cases, both alleles were affected. These findings indicate a limited role of the gene in the development of desmoid tumours outside FAP.


Assuntos
Polipose Adenomatosa do Colo/genética , Fibromatose Abdominal/genética , Fibromatose Agressiva/genética , Genes APC , Mutação , Síndromes Neoplásicas Hereditárias/genética , Adolescente , Adulto , Idoso , Feminino , Genes APC/genética , Humanos , Masculino , Pessoa de Meia-Idade , Polimorfismo Conformacional de Fita Simples
12.
Acta Obstet Gynecol Scand ; 77(1): 14-21, 1998 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9492711

RESUMO

OBJECTIVE: To investigate whether a chronobiological analysis applied to automated 24-hour blood pressure monitoring in early pregnancy provides objective parameters enabling detection of single patients at risk of pregnancy-induced hypertension or preeclampsia. METHODS: 24-hour automatic blood pressure monitoring was performed at 8-16 and 20-25 gestational weeks in 104 women at risk of pregnancy-induced hypertension or preeclampsia. The subjects were hospitalized to be synchronized to rest-activity and meal-timing schedules. All women were followed longitudinally until post-partum. Chronobiological analysis of blood pressure values was performed; sensitivity, specificity and predictive values of MESOR and hyperbaric index were also calculated. Incidence of pregnancy-induced hypertension or preeclampsia, gestational week at delivery and birthweight were recorded. RESULTS: Nine thousand nine hundred and eighty-four blood pressure measurements were analyzed. In patients who later developed overt hypertension, systolic and diastolic blood pressure MESOR, hyperbaric index and percent time elevation were already significantly higher in early pregnancy than in those who remained normotensive. The best sensitivity and specificity was obtained between 20-25 weeks of gestation with systolic single cosinor MESOR and Hyperbaric Index using as cut-off 103 mmHg (sensitivity: 88%; specificity: 75%) and 10 mmHg/24 hour (sensitivity: 70%; specificity: 92%), respectively. CONCLUSIONS: The chronobiological analysis applied to 24-hour blood pressure monitoring during pregnancy allows definition of objective cut-off values which can be particularly useful in the routine clinical practice when the risk of developing pregnancy-induced hypertension or preeclampsia must be calculated in the individual subject.


Assuntos
Pressão Sanguínea , Hipertensão/diagnóstico , Monitorização Fisiológica , Pré-Eclâmpsia/diagnóstico , Complicações Cardiovasculares na Gravidez/diagnóstico , Adolescente , Adulto , Fenômenos Cronobiológicos , Feminino , Humanos , Recém-Nascido , Gravidez , Primeiro Trimestre da Gravidez , Segundo Trimestre da Gravidez , Fatores de Risco , Sensibilidade e Especificidade
13.
Br J Obstet Gynaecol ; 104(6): 682-8, 1997 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9197871

RESUMO

OBJECTIVE: To investigate the effect of 7 to 14 days of therapy with nifedipine (sustained-release preparation) on the 24-hour blood pressure patterns of pregnant women with pre-eclampsia or chronic hypertension, and to test the utility of blood pressure monitoring in modulating the timing and dosage of the drug. DESIGN: 24-hour automatic blood pressure monitoring of pregnant women with pre-eclampsia or chronic hypertension before and after nifedipine treatment. SETTING: Centre for Prevention, Diagnosis and Treatment of Hypertension in Pregnancy, University of Turin, Italy. POPULATION: Sixteen pregnant women with pre-eclampsia and 17 with chronic hypertension. METHODS: 24-hour blood pressure monitoring was performed before the beginning of the therapy and after 7 to 14 days of treatment with sustained-release nifedipine. MAIN OUTCOME MEASURES: Chronobiological analysis of systolic and diastolic blood pressure values was performed; MESOR, amplitude, acrophase, hyperbaric index, percent time elevation and significance of rhythm were calculated before and after treatment. RESULTS: 6336 blood pressure measurements were analysed. Systolic and diastolic MESOR values were significantly decreased after nifedipine treatment both in pre-eclampsia and in chronic hypertension. However, the antihypertensive effect of nifedipine in pre-eclampsia was especially pronounced during evening and night, while in chronic hypertension it was more constant during the 24-hour period. 24-hour blood pressure monitoring allowed adjustment, when necessary, to the timing and dosage of nifedipine in accordance with the blood pressure patterns of each patient, using the hyperbaric index and percent time elevation as objective parameters for the evaluation of treatment efficacy. CONCLUSIONS: 24-hour blood pressure monitoring is a good method to optimise treatment, and confirms that nifedipine is useful for the control of maternal blood pressure in pregnancy.


Assuntos
Monitorização Ambulatorial da Pressão Arterial , Bloqueadores dos Canais de Cálcio/uso terapêutico , Monitoramento de Medicamentos/métodos , Hipertensão/tratamento farmacológico , Nifedipino/uso terapêutico , Pré-Eclâmpsia/tratamento farmacológico , Complicações Cardiovasculares na Gravidez/tratamento farmacológico , Adulto , Pressão Sanguínea/efeitos dos fármacos , Doença Crônica , Cronoterapia , Preparações de Ação Retardada , Feminino , Humanos , Gravidez , Reprodutibilidade dos Testes , Fatores de Tempo
14.
Cancer Res ; 56(3): 556-62, 1996 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-8564971

RESUMO

P53 status may be a determinant of chemosensitivity of tumor cells; however, its involvement in cellular resistance to cisplatin remains uncertain. To investigate the relationships between p53 and the development of resistance to cisplatin, the p53 gene status was studied in ovarian carcinoma cell systems which included two cisplatin-resistant variants (IGROV-1/Pt 0.5 and IGROV-1/Pt 1) selected in vitro after prolonged drug exposure of the cisplatin-sensitive parental IGROV-1 cell line. IGROV-1/Pt 0.5 and IGROV-1/Pt 1 cell lines exhibited a degree of resistance of approximately 6 and 14, respectively, following 96-h exposure to the drug and were cross-resistant to other DNA-damaging agents (ionizing radiation and melphalan). Resistance to cisplatin paralleled a reduced cell susceptibility to cisplatin-induced apoptosis. DNA single-strand conformation polymorphism analysis of exons 5-9 demonstrated the presence of two mutants alleles at exon 8 in the two resistant cell lines, in contrast to the parental IGROV-1 cell line which exhibited the wild-type p53 gene. Direct DNA sequencing revealed that the mutations consist of two nucleotide changes in the DNA-binding domain at codons 270 (T/A) and 282 (C/T). The consecutive levels of p53 protein were lower in IGROV-1 than in IGROV-1/Pt cells. Following exposure to ionizing radiation or cisplatin, accumulation of the p53 protein was markedly enhanced only in the sensitive cells. Concomitantly, the expression of WAF-1 protein was strongly induced in the parental IGROV-1 cells, whereas WAF-1 protein remained undetectable in the IGROV-1/Pt 1 subline after DNA-damaging treatment. Consistent with this finding is the observation that ionizing radiation caused a different pattern of cell cycle perturbation in sensitive and resistant cells. Northern blot analysis demonstrated a marked reduction in bax mRNA levels in IGROV-1/Pt 1 cisplatin-resistant cells. Cotransfection assays with wild-type or mutant p53 expression plasmids and a reporter gene plasmid that utilized the bax gene promoter to drive transcription of chloramphenicol acetyltransferase were consistent with the role of p53 in regulation of bax expression in these cells. Taken together, these observations support a role for mutations of the p53 gene in the development of cisplatin resistance in ovarian cancer as a consequence of loss of the ability of p53 to transactivate bax, an apoptosis-inducing gene.


Assuntos
Cisplatino/farmacologia , Genes p53 , Mutação , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/genética , Proteínas Proto-Oncogênicas c-bcl-2 , Proteínas Proto-Oncogênicas/genética , Apoptose/efeitos dos fármacos , Sequência de Bases , Northern Blotting , Western Blotting , Ciclo Celular/fisiologia , Cloranfenicol O-Acetiltransferase/genética , Inibidor de Quinase Dependente de Ciclina p21 , Ciclinas/análise , Dano ao DNA , Resistencia a Medicamentos Antineoplásicos , Feminino , Expressão Gênica , Genes Reporter , Humanos , Dados de Sequência Molecular , Neoplasias Ovarianas/metabolismo , Polimorfismo Conformacional de Fita Simples , Regiões Promotoras Genéticas , Proteínas Proto-Oncogênicas/biossíntese , RNA Mensageiro/metabolismo , Ativação Transcricional , Células Tumorais Cultivadas , Proteína Supressora de Tumor p53/análise , Proteína X Associada a bcl-2
15.
Diagn Mol Pathol ; 4(4): 239-48, 1995 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-8634779

RESUMO

Twenty-nine samples from 28 cases of vulvar squamous cell carcinoma, of which 13 fulfilled the criteria of the bowenoid subtype (mean age 45 years, range 31-68) and 16 of the usual subtype of invasive squamous cell carcinoma (ISCC) (mean age 67.5 years, range 34-83) were investigated for human papillomavirus (HPV) DNA, TP53 alterations, and mdm2 and bcl-2 gene product deregulation. Microscopically all the bowenoid subtype cases (group I) showed a high-grade intraepithelial (VIN 3, carcinoma in situ) lesion associated with early invasive carcinoma in six cases and overt invasive carcinoma in one. By contrast, no evidence of early carcinoma was present in the ISCCs (group II). By in situ hybridization and/or Southern blot hybridization or polymerase chain reaction (PCR), HPV DNA was detected in all cases of group I and in four of 16 cases (25%) of group II, two only by Southern blot after PCR. By single-strand conformation polymorphism and immunocytochemistry only wild-type TP53 and absence of detectable p53 product, respectively, were found in all cases of group I, i.e., in high-risk HPV-positive carcinomas, whereas mutations and/or p53 overexpression accounted for 75% in group II, i.e., in mainly HPV-negative carcinomas. The TP53 gene mutations observed in invasive carcinomas were significantly related to node-positive cases (p = 0.04). Taken together and in agreement with in vitro data, these results support the view that an alteration of TP53, gained either by interaction with viral oncoproteins or by somatic mutations, is a crucial event in the pathogenesis of vulvar carcinomas, but that TP53 mutations are mainly associated with disease progression. Finally, a preliminary immunocytochemical analysis seems to speak against the possible involvement of both MDM2 and BCL-2 gene products in the development of vulvar carcinoma.


Assuntos
Carcinoma de Células Escamosas/etiologia , Genes p53/genética , Papillomaviridae , Infecções por Papillomavirus/complicações , Infecções Tumorais por Vírus/complicações , Displasia do Colo do Útero/etiologia , Neoplasias Vulvares/etiologia , Adulto , Idoso , Sequência de Bases , Carcinoma de Células Escamosas/química , Carcinoma de Células Escamosas/patologia , Carcinoma de Células Escamosas/secundário , DNA Viral/análise , Feminino , Humanos , Imuno-Histoquímica , Metástase Linfática , Pessoa de Meia-Idade , Dados de Sequência Molecular , Proteínas de Neoplasias/análise , Estadiamento de Neoplasias , Infecções por Papillomavirus/patologia , Mutação Puntual , Polimorfismo Conformacional de Fita Simples , Proteínas Proto-Oncogênicas/análise , Proteína Supressora de Tumor p53/análise , Infecções Tumorais por Vírus/patologia , Neoplasias Vulvares/química , Neoplasias Vulvares/patologia , Displasia do Colo do Útero/química , Displasia do Colo do Útero/patologia
16.
Cancer Res ; 55(1): 135-40, 1995 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-7805023

RESUMO

Patients with a primary cancer in the lung or in the upper aerodigestive tract have an increased risk of developing synchronous or metachronous second primary lung tumors. This phenomenon has been related to the chronic exposure of the bronchial tree to carcinogens through a so-called "field cancerization" process. This study was designed to investigate at the somatic level the genetic basis of the field cancerization effect in patients having multiple simultaneous neoplastic and preneoplastic lesions of the lung. The pattern of specific genetic changes occurring with high frequency and in early stages of lung carcinogenesis including p53 mutations, deletions of chromosome 3p, and K-ras mutations, was investigated by immunocytochemical, cytogenetic, and molecular approaches in 11 synchronous lesions of five patients with multiple lung cancers. Different genetic lesions were observed in all of the pathological specimens analyzed from each patient. The pattern of these changes was different both in topographically distant or adjacent lesions and in tumors with the same histopathological diagnosis supporting their independent origin. The present data provide further evidence of the clinical relevance of the field cancerization process, and support the use of genetic markers in the differential diagnosis of recurrence or metastasis versus second primaries of the lung.


Assuntos
Neoplasias Pulmonares/genética , Neoplasias Primárias Múltiplas/genética , Lesões Pré-Cancerosas/genética , Adenocarcinoma/genética , Sequência de Bases , Carcinoma de Células Escamosas/genética , Deleção Cromossômica , Cromossomos Humanos Par 3 , Genes p53 , Genes ras , Humanos , Dados de Sequência Molecular , Mutação , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição
18.
Diagn Mol Pathol ; 2(4): 248-56, 1993 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-8118602

RESUMO

We examined five cases of verrucous carcinoma (VC) and two cases of giant condyloma of Buschke-Löwenstein (GCBL) associated with invasive squamous cell carcinoma (ISCC), by immunocytochemistry and molecular techniques. Neither human papillomavirus (HPV) footprints nor p53-altered expression and/or mutation were observed among the cases of VC. By contrast, both cases of GCBL with ISCC turned out to be HPV 6 or 11 positive, showed overexpression of p53 and, one of the two, a mutation in the nucleotide sequence of this tumor suppressor gene. The results point out that VC and GCBL with ISCC, in spite of some morphologic similarities, are two distinct entities, the former being unrelated to both HPV and p53 inactivation and the latter related to both. Regarding p53, immunocytochemical and molecular data on GCBL with ISCC suggest a role of mutant p53 in the progression of malignancy into invasion.


Assuntos
Carcinoma Verrucoso/química , Carcinoma Verrucoso/microbiologia , Papillomaviridae/isolamento & purificação , Neoplasias Penianas/química , Neoplasias Penianas/microbiologia , Proteína Supressora de Tumor p53/análise , Neoplasias Vulvares/química , Neoplasias Vulvares/microbiologia , Adulto , Idoso , Sequência de Bases , Southern Blotting , Carcinoma Verrucoso/genética , DNA Viral/análise , DNA Viral/genética , Feminino , Regulação Neoplásica da Expressão Gênica/genética , Genes p53/genética , Humanos , Imuno-Histoquímica , Hibridização In Situ , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Papillomaviridae/genética , Neoplasias Penianas/genética , Reação em Cadeia da Polimerase , Polimorfismo Genético , Proteína Supressora de Tumor p53/genética , Neoplasias Vulvares/genética
19.
Minerva Ginecol ; 45(5): 223-33, 1993 May.
Artigo em Italiano | MEDLINE | ID: mdl-8351060

RESUMO

Approximately 10% of premenopausal women suffer from dysfunctional menometrorrhagia. The correct therapeutic approach to this pathology above all requires a precise diagnostic framework. For this purpose the doctor can employ a number of laboratory and instrumental tests, both invasive and non-invasive, in order to differentiate the dysfunctional forms from those supported by organic pathologies or non-gynecological diseases. Once the diagnostic iter has been completed, the choice of therapy can be directed towards surgical or medical treatment; the latter may be symptomatic or causal. This review focuses on the most commonly used treatments for dysfunctional menometrorrhagia in premenopausal women and proposes clinical protocols for a correct diagnostic and therapeutic approach.


Assuntos
Menopausa , Menorragia/etiologia , Metrorragia/etiologia , Doenças do Sistema Endócrino/complicações , Feminino , Humanos , Histerectomia , Menorragia/fisiopatologia , Menorragia/terapia , Metrorragia/fisiopatologia , Metrorragia/terapia , Doenças Uterinas/complicações
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA