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1.
Aliment Pharmacol Ther ; 48(4): 431-439, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29920698

RESUMO

BACKGROUND: Long-term oral nucleos(t)ide analogue (NUC) therapy in hepatitis B virus (HBV)-related compensated cirrhotics prevents clinical decompensation but not hepatocellular carcinoma (HCC) development. AIMS: To define the clinical features and outcomes of HCC in long-term NUC-treated HBV patients. METHODS: All HCCs developing between 2005 and 2016 in NUC-treated HBV patients under surveillance were studied, excluding those that occurred within the first 6 months of therapy. Clinical features of HCC, alpha faetoprotein (AFP) patterns and patients' outcome were studied. RESULTS: Seventy-six HCC patients were included. Median age was 67 (40-83) years, 84% males, 96% Caucasian, 95% HBeAg-negative, 96% with undetectable HBV DNA, 83% with normal ALT levels, and 92% with compensated cirrhosis. Median serum AFP levels were 4 (1-3615) ng/mL (>7 ng/mL in 36%). HCC was monofocal in 78%, had a median diameter of 20 (6-57) mm and was in its early stage in 92% which allowed potentially curative treatments in 78% (39% ablation, 28% surgical resection, 11% liver transplantation). Overall, a complete response was obtained in 61 (80%) patients: in 40 after a first-line treatment, in 3 after the second-line treatment, in 2 after the third-line treatment, while 16 underwent liver transplantation (8 as second line). During 45 (7-144) months after HCC diagnosis, 19 patients died, 84% from HCC progression. The median time to recurrence was 20.2 (3-53) months, and the cumulative 5-year liver-related survival was 74%. CONCLUSIONS: HCCs developing in patients under long-term NUC treatment were single, small tumours, amenable to curative therapies able to confer excellent 5-year survival rates.


Assuntos
Antivirais/uso terapêutico , Carcinoma Hepatocelular/tratamento farmacológico , Hepatite B Crônica/tratamento farmacológico , Cirrose Hepática/tratamento farmacológico , Neoplasias Hepáticas/tratamento farmacológico , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma Hepatocelular/complicações , Carcinoma Hepatocelular/etnologia , Carcinoma Hepatocelular/mortalidade , Feminino , Seguimentos , Hepatite B Crônica/complicações , Hepatite B Crônica/etnologia , Hepatite B Crônica/mortalidade , Humanos , Cirrose Hepática/complicações , Cirrose Hepática/etnologia , Cirrose Hepática/mortalidade , Neoplasias Hepáticas/complicações , Neoplasias Hepáticas/etnologia , Neoplasias Hepáticas/mortalidade , Transplante de Fígado/estatística & dados numéricos , Quimioterapia de Manutenção , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/tratamento farmacológico , Recidiva Local de Neoplasia/etnologia , Recidiva Local de Neoplasia/mortalidade , Recidiva Local de Neoplasia/virologia , Taxa de Sobrevida , Resultado do Tratamento , População Branca/estatística & dados numéricos
2.
Int J Implant Dent ; 4(1): 1, 2018 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-29318405

RESUMO

BACKGROUND: When keratinized tissue width around dental implants is poorly represented, the clinician could resort to autogenous soft tissue grafting. Autogenous soft tissue grafting procedures are usually associated with a certain degree of morbidity. Collagen matrices could be used as an alternative to reduce morbidity and intra-operatory times. The aim of this study was to assess the efficacy of a xenogeneic collagen matrix as a substitute for soft tissue grafting around dental implants. METHODS: Fifteen consecutive patients underwent a vestibuloplasty and keratinized tissue reconstruction around dental implants, both in the mandible and the maxilla, with a porcine collagen matrix. The so obtained keratinized tissues were measured and evaluated after 6 months and 1, 4, and 5 years. RESULTS: The average gain of keratinized tissue was 5.7 mm. After 6 months, it was observed a resorption of 37%, after 1 year 48%, and after 5 years 59%. The mean gain of keratinized tissue after 5 years was 2.4 mm. Hemostatic effect and post-operative pain were evaluated too. All subjects referred minimal pain with no bleeding. No adverse reaction nor infection was noted. CONCLUSIONS: The present study showed the efficacy of a porcine collagen matrix in keratinized tissue augmentation. The possibility to use a soft tissue substitute is a great achievement as morbidity decreases and bigger areas can be treated in a single surgery.

3.
J Dent ; 43(1): 78-86, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25150106

RESUMO

OBJECTIVES: The aim of the present long-term study was to retrospectively evaluate the survival rate of implants placed in regenerated maxillary sinuses and to assess the influence of hypothetical predictors of implant failure. METHODS: A database including 218 patients who received dental implants after sinus lift procedures was analyzed. The following variables were systematically included and evaluated: type of graft material used, number of surgeries performed, and use of membranes to cover the lateral antrostomy and/or to repair accidental Schneiderian membrane perforations. The Kaplan-Meier estimator was used for comparisons among the groups. RESULTS: A total of 589 dental implants were positioned in 246 grafted sinuses and were in function for 3-186 months. The Kaplan-Meier cumulative survival rate was 98.3% after 15.5 years of follow-up. All implant losses occurred within 52 months (4.3 years) after augmentation. According to the log-rank test, no statistically significant difference was shown between each patient/implant variable (p>0.05). CONCLUSIONS: Despite the limitations inherent in this type of study, no statistically significant differences between the groups could be found. Intraoperative Schneiderian membrane perforations did not affect the outcome of the implants positioned. CLINICAL SIGNIFICANCE: The present long-term study is intended as a reference for clinicians approaching sinus floor elevation surgery in order to provide them with relevant operative findings. Since all the drawbacks occurred within the first 5 years, medium-term follow-up studies could be suitable for further retrospective evaluations.


Assuntos
Perda do Osso Alveolar/cirurgia , Implantação Dentária Endóssea/métodos , Implantes Dentários , Levantamento do Assoalho do Seio Maxilar/métodos , Adulto , Idoso , Perda do Osso Alveolar/epidemiologia , Perda do Osso Alveolar/patologia , Regeneração Óssea , Implantação Dentária Endóssea/efeitos adversos , Falha de Restauração Dentária , Feminino , Humanos , Estimativa de Kaplan-Meier , Estudos Longitudinais , Masculino , Seio Maxilar/crescimento & desenvolvimento , Seio Maxilar/patologia , Seio Maxilar/cirurgia , Pessoa de Meia-Idade , Estudos Retrospectivos , Levantamento do Assoalho do Seio Maxilar/efeitos adversos
4.
Minerva Stomatol ; 62(10): 397-404, 2013 Oct.
Artigo em Inglês, Italiano | MEDLINE | ID: mdl-24217687

RESUMO

The aim of this article was to describe a rare case of paradental cyst of the permanent mandibular second molar. A 14-year-old girl was referred to Oral Surgery Department, Dental Clinic, IRCSS Fondazione Ca' Granda, University of Milan, Italy, for the evaluation of the deep probing located on the buccal aspect of her erupted mandibular left second molar. Clinical signs of inflammation were absent and the mucosa around the second molar appeared clinically normal. Pulp tests for the second molar were positive. The evaluation of the panoramic radiograph did not revealed radiolucency. The Cone-beam tomography showed a well-defined semilunar-shaped radiolucency demarcated by a fine radiopaque line. The cyst was enucleated. The histopathologic analisys revealed the presence of hyperplastic, non-keratinized squamous epithelium with heavy, dense inflammatory cell infiltrate in the epitelium and connective tissue wall. This analysis associated with macroscopic, clinical and radiografic examination confirmed the diagnosis of paradental cyst. A clinic-pathologic correlation, incorporating the surgical, radiographic and histologic findings, is required to obtain the final diagnosis of paradental cyst. Today, the treatment of choice is simple enucleation and thorough curettage of the cyst without extraction of the involved tooth, but if CT demonstrates erosions in the buccal or lingual cortices, marsupialization should be the treatment of choice.


Assuntos
Doenças Mandibulares , Dente Molar , Cisto Periodontal , Adolescente , Feminino , Humanos , Doenças Mandibulares/patologia , Cisto Periodontal/patologia
5.
J Indian Soc Pedod Prev Dent ; 30(4): 343-8, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23514690

RESUMO

The paradental cyst is a lesion classified and recognized by World Health Organization quite recently, which is related to an inflammatory process, especially pericoronitis, involving a tooth in eruption. The aim of this article is to report a rare bilateral case of paradental cyst. An 8-year-old boy presented to the Oral Surgery Department, Dental Clinic, Istituto di Ricerca e Cura a Carattere Scientifico (IRCCS) Fondazione Ospedale Maggiore Policlinico, University of Milan, with the complaint of swelling over the buccal gingiva of his unerupted lower left first molar. Radiographs revealed a radiolucency involving the bifurcation and root area of teeth 36 and 46. The cysts were enucleated, maintaining the affected teeth in site; microscopic evaluation revealed a chronically inflamed cyst lined by a non-keratinized stratified squamous epithelium; the histopathology associated with macroscopic and radiographic examinations permitted the definitive diagnosis of a paradental cyst on the mandibular left and right first molars. The most recent literature shows the rarity of the paradental cyst occurring with bilateral localization. Because the paradental cyst can present variable clinical and radiographic signs, it is mandatory to correlate all clinical, radiographic, and histological data to obtain a definitive diagnosis.


Assuntos
Dente Molar/patologia , Cisto Periodontal/diagnóstico , Criança , Tecido Conjuntivo/patologia , Diagnóstico Diferencial , Epitélio/patologia , Seguimentos , Humanos , Masculino , Doenças Mandibulares/diagnóstico , Radiografia Panorâmica , Tomografia Computadorizada por Raios X , Raiz Dentária/patologia
6.
J Indian Soc Pedod Prev Dent ; 28(2): 116-20, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20660980

RESUMO

OBJECTIVE: The paradental cyst is an uncommon lesion associated with the permanent mandibular first or second molar in children just prior to tooth eruption. The purpose of this article is to present two cases of paradental cyst affecting the buccal aspect of permanent mandibular first molar of both young patients. We also discuss diagnosis, treatment and radiographic findings of the cases. PATIENTS AND METHODS: In both cases was made only the enucleation of cyst without extraction of the adjacent tooth. Lesional samples were sent for histopathologic analysis. RESULTS: The histopathologic analysis of both cases, revealed a lining of hyperplastic, nonkeratinized squamous epithelium with heavy, dense inflammatory cell infiltrate in the epithelium and connective tissue wall. The histopathology associated with macroscopic and radiographic examination permitted the definitive diagnosis of a paradental cyst on the mandibular left first molar. A follow-up of 1 year was carried out in both cases and no recurrences was noted; in the first case was observed the correct eruption of the mandibular permanent left first molar. CONCLUSIONS: A clinicopathologic correlation, incorporating the surgical, radiographic, and histological finding, is required to obtain the final diagnosis of paradental cyst. Today, the treatment of choice is simple enucleation and thorough curettage of the cyst without extraction of the involved tooth.


Assuntos
Doenças Mandibulares/patologia , Dente Molar/patologia , Cisto Periodontal/patologia , Criança , Humanos , Masculino , Doenças Mandibulares/diagnóstico por imagem , Doenças Mandibulares/cirurgia , Cisto Periodontal/diagnóstico por imagem , Cisto Periodontal/cirurgia , Radiografia , Erupção Dentária
7.
Radiat Res ; 169(5): 575-83, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18439037

RESUMO

The case for a DNA-damaging action produced by radiofrequency (RF) signals remains controversial despite extensive research. With the advent of the Universal Mobile Telecommunication System (UMTS) the number of RF-radiation-exposed individuals is likely to escalate. Since the epigenetic effects of RF radiation are poorly understood and since the potential modifications of repair efficiency after exposure to known cytotoxic agents such as ionizing radiation have been investigated infrequently thus far, we studied the influence of UMTS exposure on the yield of chromosome aberrations induced by X rays. Human peripheral blood lymphocytes were exposed in vitro to a UMTS signal (frequency carrier of 1.95 GHz) for 24 h at 0.5 and 2.0 W/kg specific absorption rate (SAR) using a previously characterized waveguide system. The frequency of chromosome aberrations was measured on metaphase spreads from cells given 4 Gy of X rays immediately before RF radiation or sham exposures by fluorescence in situ hybridization. Unirradiated controls were RF-radiation- or sham-exposed. No significant variations due to the UMTS exposure were found in the fraction of aberrant cells. However, the frequency of exchanges per cell was affected by the SAR, showing a small but statistically significant increase of 0.11 exchange per cell compared to 0 W/kg SAR. We conclude that, although the 1.95 GHz signal (UMTS modulated) does not exacerbate the yield of aberrant cells caused by ionizing radiation, the overall burden of X-ray-induced chromosomal damage per cell in first-mitosis lymphocytes may be enhanced at 2.0 W/kg SAR. Hence the SAR may either influence the repair of X-ray-induced DNA breaks or alter the cell death pathways of the damage response.


Assuntos
Telefone Celular , Aberrações Cromossômicas/efeitos da radiação , Linfócitos/efeitos da radiação , Micro-Ondas/efeitos adversos , Raios X/efeitos adversos , Adulto , Morte Celular/efeitos da radiação , Células Cultivadas , Reparo do DNA/efeitos da radiação , Humanos , Linfócitos/citologia , Linfócitos/metabolismo , Masculino , Modelos Biológicos
8.
Health Phys ; 94(3): 242-7, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18301097

RESUMO

Shielding is the only practical countermeasure for the exposure to cosmic radiation during space travel. It is well known that light, hydrogenated materials, such as water and polyethylene, provide the best shielding against space radiation. Kevlar and Nextel are two materials of great interest for spacecraft shielding because of their known ability to protect human space infrastructures from meteoroids and debris. We measured the response to simulated heavy-ion cosmic radiation of these shielding materials and compared it to polyethylene, Lucite (PMMA), and aluminum. As proxy to galactic nuclei we used 1 GeV n iron or titanium ions. Both physics and biology tests were performed. The results show that Kevlar, which is rich in carbon atoms (about 50% in number), is an excellent space radiation shielding material. Physics tests show that its effectiveness is close (80-90%) to that of polyethylene, and biology data suggest that it can reduce the chromosomal damage more efficiently than PMMA. Nextel is less efficient as a radiation shield, and the expected reduction on dose is roughly half that provided by the same mass of polyethylene. Both Kevlar and Nextel are more effective than aluminum in the attenuation of heavy-ion dose.


Assuntos
Teste de Materiais/instrumentação , Aceleradores de Partículas/instrumentação , Proteção Radiológica/métodos , Astronave/instrumentação , Humanos , Doses de Radiação , Radiometria
9.
Radiat Res ; 164(4 Pt 2): 571-6, 2005 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16187790

RESUMO

We report results for chromosomal aberrations in human peripheral blood lymphocytes after they were exposed to high-energy iron ions with or without shielding at the HIMAC, AGS and NSRL accelerators. Isolated lymphocytes were exposed to iron ions with energies between 200 and 5000 MeV/nucleon in the 0.1-1-Gy dose range. Shielding materials consisted of polyethylene, lucite (PMMA), carbon, aluminum and lead, with mass thickness ranging from 2 to 30 g/cm2. After exposure, lymphocytes were stimulated to grow in vitro, and chromosomes were prematurely condensed using a phosphatase inhibitor (calyculin A). Aberrations were scored using FISH painting. The yield of total interchromosomal exchanges (including dicentrics, translocations and complex rearrangements) increased linearly with dose or fluence in the range studied. Shielding decreased the effectiveness per unit dose of iron ions. The highest RBE value was measured with the 1 GeV/nucleon iron-ion beam at NSRL. However, the RBE for the induction of aberrations apparently is not well correlated with the mean LET. When shielding thickness was increased, the frequency of aberrations per particle incident on the shield increased for the 500 MeV/nucleon ions and decreased for the 1 GeV/nucleon ions. Maximum variation at equal mass thickness was obtained with light materials (polyethylene, carbon or PMMA). Variations in the yield of chromosomal aberrations per iron particle incident on the shield follow variations in the dose per incident particle behind the shield but can be modified by the different RBE of the mixed radiation field produced by nuclear fragmentation. The results suggest that shielding design models should be benchmarked using both physics and biological data.


Assuntos
Aberrações Cromossômicas , Íons Pesados/efeitos adversos , Proteção Radiológica , Relação Dose-Resposta a Droga , Humanos , Ferro , Transferência Linear de Energia , Linfócitos/efeitos da radiação , Linfócitos/ultraestrutura
10.
Adv Space Res ; 35(2): 230-5, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-15934199

RESUMO

We measured fluence and fragmentation of high-energy (1 or 5 A GeV) 56Fe ions accelerated at the Alternating Gradient Synchrotron or at the NASA Space Radiation Laboratory (Brookhaven National Laboratory, NY, USA) using solid-state CR-39 nuclear track detectors. Different targets (polyethylene, PMMA, C, Al, Pb) were used to produce a large spectrum of charged fragments. CR-39 plastics were exposed both in front and behind the shielding block (thickness ranging from 5 to 30 g/cm2) at a normal incidence and low fluence. The radiation dose deposited by surviving Fe ions and charged fragments was measured behind the shield using an ionization chamber. The distribution of the measured track size was exploited to distinguish the primary 56Fe ions tracks from the lighter fragments. Measurements of projectile's fluence in front of the shield were used to determine the dose per incident particle behind the block. Simultaneous measurements of primary 56Fe ion tracks in front and behind the shield were used to evaluate the fraction of surviving iron projectiles and the total charge-changing fragmentation cross-section. These physical measurements will be used to characterize the beam used in parallel biological experiments.


Assuntos
Íons Pesados , Ferro , Monitoramento de Radiação/instrumentação , Proteção Radiológica , Alumínio , Calibragem , Carbono , Chumbo , Transferência Linear de Energia , Plásticos , Polietileno , Polietilenoglicóis , Polimetil Metacrilato , Doses de Radiação , Espalhamento de Radiação , Voo Espacial , Síncrotrons
11.
Adv Space Res ; 34(6): 1358-61, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15880937

RESUMO

Biophysical models are commonly used to evaluate the effectiveness of shielding in reducing the biological damage caused by cosmic radiation in space flights. To improve and validate these codes biophysical experiments are needed. We have measured the induction of chromosomal aberrations in human peripheral blood lymphocytes exposed in vitro to 500 MeV/n iron ion beams (dose range 0.1-1 Gy) after traversing shields of different material (lucite, aluminium, or lead) and thickness (0-11.3 g/cm2). For comparison, cells were exposed to 200 MeV/n iron ions and to X-rays. Chromosomes were prematurely condensed by a phosphatase inhibitor (calyculin A) to avoid cell-cycle selection produced by the exposure to high-LET heavy-ion beams. Aberrations were scored in chromosomes 1, 2, and 4 following fluorescence in situ hybridization. The fraction of aberrant lymphocytes has been evaluated as a function of the dose at the sample position, and of the fluence of primary 56Fe ions hitting the shield. The influence of shield thickness on the action cross-section for the induction of exchange-type aberrations has been analyzed, and the dose average-LET measured as a function of the shield thickness. These preliminary results prove that the effectiveness of heavy ions is modified by shielding, and the biological damage is dependent upon shield thickness and material.


Assuntos
Aberrações Cromossômicas , Cromossomos/efeitos da radiação , Ferro , Proteção Radiológica , Alumínio , Ciclo Celular/efeitos da radiação , Relação Dose-Resposta à Radiação , Inibidores Enzimáticos , Humanos , Chumbo , Transferência Linear de Energia , Linfócitos/efeitos da radiação , Toxinas Marinhas , Oxazóis , Aceleradores de Partículas , Fosfoproteínas Fosfatases/antagonistas & inibidores , Polimetil Metacrilato , Voo Espacial
12.
Adv Space Res ; 31(6): 1495-503, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-12971404

RESUMO

Large uncertainties are associated with estimates of equivalent dose and cancer risk for crews of long-term space missions. Biological dosimetry in astronauts is emerging as a useful technique to compare predictions based on quality factors and risk coefficients with actual measurements of biological damage in-flight. In the present study, chromosomal aberrations were analyzed in one Italian and eight Russian cosmonauts following missions of different duration on the MIR and the international space station (ISS). We used the technique of fluorescence in situ hybridization (FISH) to visualize translocations in chromosomes 1 and 2. In some cases, an increase in chromosome damage was observed after flight, but no correlation could be found between chromosome damage and flight history, in terms of number of flights at the time of sampling, duration in space and extra-vehicular activity. Blood samples from one of the cosmonauts were exposed in vitro to 6 MeV X-rays both before and after the flight. An enhancement in radiosensitivity induced by the spaceflight was observed.


Assuntos
Astronautas , Aberrações Cromossômicas/estatística & dados numéricos , Radiação Cósmica , Linfócitos/efeitos da radiação , Exposição Ocupacional , Voo Espacial , Aberrações Cromossômicas/classificação , Relação Dose-Resposta à Radiação , Atividade Extraespaçonave , Humanos , Itália , Linfócitos/citologia , Neoplasias Induzidas por Radiação/prevenção & controle , Doses de Radiação , Medição de Risco , Federação Russa
13.
J Agric Food Chem ; 49(12): 6026-32, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11743803

RESUMO

The presence of the oxidized and reduced forms of ubiquinones Q(9) and Q(10) was determined in commercial extra virgin olive and seed oils, where the amounts of alpha- and gamma-tocopherols and beta-carotene were also quantitated. Very high concentrations of ubiquinones were found in soybean and corn oils. Furthermore, the total antioxidant capability of each oil was evaluated by measuring total radical-trapping antioxidant parameters (TRAP) in tert-butyl alcohol and using egg lecithin as the oxidizable substrate. These values decreased in the order sunflower > corn > peanut > olive; the highest TRAP, which was found in sunflower oil, was related to the very high amount of alpha-tocopherol. Olive oil, because of the low content of alpha-tocopherol, exhibited a TRAP value approximately one-third that of sunflower oil. TRAP values of corn and soybean oils, in which low amounts of alpha-tocopherol but very high contents of gamma-tocopherol and reduced ubiquinones were present, were intermediate. gamma-Tocopherol exhibited a poor ability of trapping peroxyl radicals in tert-butyl alcohol. This behavior was probably due to the effects of the solvent on the rate of hydrogen abstraction from this phenol.


Assuntos
Antioxidantes/química , Peróxidos/química , Óleos de Plantas/química , Radicais Livres/química , Azeite de Oliva , Oxirredução , Fenóis/análise , Especificidade da Espécie , Ubiquinona/análise , alfa-Tocoferol/análise , gama-Tocoferol/análise
14.
Adv Space Res ; 27(2): 345-54, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11642296

RESUMO

Astronauts' radiation exposure limits are based on experimental and epidemiological data obtained on Earth. It is assumed that radiation sensitivity remains the same in the extraterrestrial space. However, human radiosensitivity is dependent upon the response of the hematopoietic tissue to the radiation insult. It is well known that the immune system is affected by microgravity. We have developed a mathematical model of radiation-induced myelopoiesis which includes the effect of microgravity on bone marrow kinetics. It is assumed that cellular radiosensitivity is not modified by the space environment, but repopulation rates of stem and stromal cells are reduced as a function of time in weightlessness. A realistic model of the space radiation environment, including the HZE component, is used to simulate the radiation damage. A dedicated computer code was written and applied to solar particle events and to the mission to Mars. The results suggest that altered myelopoiesis and lymphopoiesis in microgravity might increase human radiosensitivity in space.


Assuntos
Radiação Cósmica/efeitos adversos , Modelos Biológicos , Tolerância a Radiação , Voo Espacial , Ausência de Peso , Medicina Aeroespacial , Astronautas , Fenômenos Fisiológicos Celulares/efeitos da radiação , Sobrevivência Celular/efeitos da radiação , Relação Dose-Resposta à Radiação , Meio Ambiente Extraterreno , Células-Tronco Hematopoéticas/efeitos da radiação , Humanos , Leucopoese/efeitos da radiação , Transferência Linear de Energia , Marte , Neoplasias Induzidas por Radiação , Proteção Radiológica , Atividade Solar
15.
Pharmacol Res ; 43(5): 445-52, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11394936

RESUMO

The 1,4- and the 1,5-benzodiazepines (BDZ) are commonly used as anxiolytic and anticonvulsive drugs. It has been suggested that they influence, particularly through stimulation of peripheral BDZ receptors, some immune cell properties such as pro-inflammatory cytokine production. The availability of a new class of [1,2,4]triazolo[4,3-a][1,5]benzodiazepine derivatives (compounds IV), endowed with anti-inflammatory and/or analgesic properties but no anti-pentylenetetrazole activity, prompted us to investigate in more detail the anti-inflammatory properties of three selected compounds IV (N,N-dimethyl-1-phenyl-4H-[1,2,4]triazolo[4,3-a][1,5]benz- odiazepin-5-amine; N,N-dibutyl-4H-[1,2,4]triazolo[4,3-a][1,5]benzodiazepin-5-amine; 1-methyl-N,N-dimethyl-4H-[1,2,4]triazolo[4,3-a][1,5]benzodiazepin-5-amine) and one structurally related compound (1-phenyl-4H-[1,2,4]triazolo[4,3-a][1,5]benzodiazepin-5(6H)-one). These BDZ derivatives have lost their affinity for the central and peripheral BDZ receptors. The in vivo effect on leukocyte migration of these compounds was investigated by using the mouse air-pouch model of local inflammation. Compounds A and B, significantly inhibited the carrageenan-induced leukocyte recruitment in a dose-dependent manner starting from the dose of 50 mgkg(-1), whereas compound C was effective only at the higher dose of 100 mgkg(-1). Compound D did not exert such effects at any of the doses considered. The effect of compounds A, B and C on leukocyte recruitment was paralleled by a significant inhibition of interleukin-6 and prostaglandin E(2)production in the exudate, similarly to indomethacin, and by a partial reduction of vascular permeability. These features may be relevant for the design and development of innovative anti-inflammatory molecules among the 4H-[1,2,4]triazolo[4,3-a][1,5]benzodiazepin-5-amine derivatives.


Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Benzodiazepinas/farmacologia , Dinoprostona/biossíntese , Interleucina-6/biossíntese , Analgésicos/farmacologia , Animais , Anti-Inflamatórios não Esteroides/síntese química , Benzodiazepinas/síntese química , Permeabilidade Capilar/efeitos dos fármacos , Carragenina , Edema/induzido quimicamente , Edema/prevenção & controle , Feminino , Leucócitos/efeitos dos fármacos , Masculino , Camundongos , Medição da Dor/efeitos dos fármacos , Receptores de GABA-A/efeitos dos fármacos , Receptores de Serotonina/efeitos dos fármacos , Células Tumorais Cultivadas
16.
Phys Med ; 17 Suppl 1: 141-2, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11771539

RESUMO

The 3MV HVEC TTT-3 Tandem accelerator at the University of Naples, already used for radiobiological studies with protons and alpha particles, was set up for irradiation of biological samples with low energy carbon, boron, and beryllium beams. Radiobiological characterisation and study of these ion beams is essential in hadrontherapy (correction of hadrotherapy) to understand, for example, the possible biological effect of the target fragmentation products. Furthermore in space radiation biology we need to know the biological effects of heavy ions, a component of cosmic radiation that can contribute to the radiobiological risk when long sojourns in space are concerned. V79 Chinese hamster cells were irradiated with the different ions and the resulting cell inactivation data are reported.


Assuntos
Berílio , Boro , Carbono , Sobrevivência Celular/efeitos da radiação , Íons Pesados , Animais , Células Cultivadas/efeitos da radiação , Cricetinae , Cricetulus , Relação Dose-Resposta à Radiação , Aceleradores de Partículas , Eficiência Biológica Relativa
17.
Phys Med ; 17 Suppl 1: 181-2, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11771552

RESUMO

Astronauts' radiation exposure limits are based on experimental and epidemiological data obtained on Earth. It is assumed that radiation sensitivity remains the same in the extraterrestrial space. However, human radiosensitivity is dependent upon the response of the hematopoietic tissue to the radiation insult. It is well known that the immune system is affected by microgravity. We have developed a mathematical model of radiation-induced myelopoiesis which includes the effect of microgravity on bone marrow kinetics. It is assumed that cellular radiosensitivity is not modified by the space environment, but repopulation rates of stem and stromal cells are reduced as a function of time in weightlessness. A realistic model of the space radiation environment, including the HZE component, is used to simulate the radiation damage. A dedicated computer code was written and applied to solar particle events and to the mission to Mars. The results suggest that altered myelopoiesis and lymphopoiesis in microgravity might increase human radiosensitivity in space.


Assuntos
Radiação Cósmica , Leucopoese/efeitos da radiação , Modelos Biológicos , Atividade Solar , Voo Espacial , Ausência de Peso/efeitos adversos , Sobrevivência Celular/efeitos da radiação , Células-Tronco Hematopoéticas/efeitos da radiação , Humanos , Transferência Linear de Energia , Marte , Neoplasias Induzidas por Radiação , Proteção Radiológica , Tolerância a Radiação
18.
Phys Med ; 17 Suppl 1: 241-6, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11776987

RESUMO

In this paper we present some preliminary results on alteration of gene expression caused by radiation on human endometrial cells. To this purpose, we have studied the modulation of the expression of the bcl-2 gene family in two cell lines following irradiations with low energy protons and gamma-rays from a 60Co. The two epithelial cell strains, namely AN3Ca and HEC1B cells, both obtained from human neoplastic endometrial tissues, grow in culture and continue to maintain some differentiated functions typical of the original tissue. Indeed, these cells, that can be considered as representative of different stages of cellular transformation of endometrium. Because their epithelial nature and rapid growth, the expression of genes related to the maintenance of the cellular homeostasis (correction of omeostasis), as the pro and anti-apoptotic ones, is expected to be susceptible to changes in environment, including radiation. The effects have been evaluated in terms of both cell survival and changes in the expression of pro- and anti apoptotic proteins. Even though the data reported above can not be considered complete and/or definitive, nevertheless, in whole, they confirm that these cells may constitute a suitable model system to study, at molecular level, the effects of cosmic radiation on endometrium. Further observation, ensuing from these preliminary data, is that endometrial cells present different sensitivity to radiation in regard to its 'quality' and 'dosage', in accord to the original stage of differentiation.


Assuntos
Apoptose/efeitos da radiação , Radiação Cósmica , Endométrio/efeitos da radiação , Regulação da Expressão Gênica/efeitos da radiação , Genes bcl-2/efeitos da radiação , Ciclo Celular/efeitos da radiação , Linhagem Celular , Transformação Celular Neoplásica/genética , Relação Dose-Resposta à Radiação , Endométrio/citologia , Feminino , Raios gama , Humanos , Prótons , Células Tumorais Cultivadas/efeitos da radiação
19.
Integr Physiol Behav Sci ; 36(3): 205-19, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11777016

RESUMO

OBJECTIVE: The study investigated the associations between self-rated financial strain and overall diurnal salivary cortisol levels, as well as secretory patterns among long-term unemployed individuals. METHODS: Psychosocial and life-style variables were assessed by means of questionnaires among 85 participants (mean age 42+/-9 years; 56% females). Salivary cortisol was sampled on four occasions during a 24-hour period and data was analysed separately for men and women. RESULTS: Among females, high financial strain was related to higher overall cortisol levels, and to elevated levels in the evening. These associations did not reach significance among men. Multivariate analyses showed that evening levels of cortisol were positively associated with financial strain, but largely unrelated to life-style variables and psychological distress. CONCLUSIONS: The results suggest that high financial strain influences the diurnal cortisol secretion of unemployed individuals in terms of elevated cortisol levels in the evening. The mediating mechanisms are in need of further investigation.


Assuntos
Ritmo Circadiano/fisiologia , Hidrocortisona/metabolismo , Saliva/metabolismo , Estresse Psicológico/psicologia , Desemprego/psicologia , Adulto , Afeto/fisiologia , Consumo de Bebidas Alcoólicas/psicologia , Ansiedade/psicologia , Depressão/psicologia , Feminino , Nível de Saúde , Humanos , Estilo de Vida , Masculino , Escalas de Graduação Psiquiátrica , Fumar/psicologia , Estresse Psicológico/economia , Suécia
20.
Metabolism ; 49(11): 1434-9, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11092507

RESUMO

The fasting plasma level of reduced glutathione (GSH), a methionine-derived tripeptide, is reduced in cirrhosis. There is evidence that a reduced activity of S-adenosyl-L-methionine synthetase limiting the flux of methionine along the transmethylation/transsulfuration pathway may contribute to decrease GSH levels. No studies have analyzed plasma GSH in response to a methionine load. In 6 control subjects and in 10 patients with cirrhosis, plasma sulfur amino acid and plasma and erythrocyte GSH levels were measured in response to a L-methionine load (0.1 g/kg). Blood samples were obtained throughout the day after the oral load. Urine was collected for measurement of sulfur excretion. During the study period, all subjects consumed a standard diet of 1,683 kcal containing 2% protein and virtually no methionine. Plasma methionine increased in both groups to a peak level exceeding 20 times the basal value 90 minutes after the load, and declined thereafter. Methionine clearance, calculated on the descending part of the methionine-time curve, was reduced by 50% in cirrhosis (P = .0001). Fasting GSH was higher in controls (mean +/- SD, 3.9 +/- 1.3 v 1.6 +/- 0.7 micromol/L, P = .0004). In response to a methionine load, it peaked at 10.2 +/- 7.2 and 3.2 +/- 1.3 micromol/L, respectively (P = .009). Thereafter, plasma GSH progressively declined, and after 24 hours, it returned to the fasting preinfusion values in both groups. Plasma cysteine and taurine concentrations, as well as the erythrocyte GSH time course, paralleled plasma GSH levels, with less significant differences between groups. Sulfate excretion was delayed. GSH synthesis is stimulated by a methionine load. The reduced flux of methionine along the transmethylation/transsulfuration pathway reduces GSH synthesis in cirrhosis. Defective methionine metabolism also may be responsible for reduced fasting GSH.


Assuntos
Glutationa/biossíntese , Cirrose Hepática/metabolismo , Metionina/administração & dosagem , Idoso , Estudos de Casos e Controles , Cisteína/sangue , Cistina/sangue , Eritrócitos/metabolismo , Feminino , Glutationa/sangue , Humanos , Cinética , Masculino , Metionina/sangue , Metionina/urina , Pessoa de Meia-Idade , Taurina/sangue
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