Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 124
Filtrar
2.
Community Dent Health ; 29(1): 106-9, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22482260

RESUMO

OBJECTIVE: The relationship between cystic fibrosis (CF) and caries experience has already been explored, but relatively little information is available on dental enamel defects prevalence among children affected by cystic fibrosis. The aim of this study was to investigate this issue in deciduous and permanent teeth of children with CF resident in southern Italy. BASIC RESEARCH DESIGN: This cross sectional observational study was undertaken between October 2009 and March 2010. PARTICIPANTS: 88 CF patients and 101 healthy age-matched participated in this study. METHODS: The prevalence of dental enamel defects was calculated using a modified Developmental Defects of Enamel (DDE) index. The comparison of dental enamel defects prevalence among groups was carried out using regression binary logistic analysis. RESULTS: In the CF subjects there was a higher prevalence (56%) of enamel defects in comparison to the healthy group (22%). The most prevalent enamel defect was hypoplasia with loss of enamel (23% of CF patients vs 1 1/2% of control group) in permanent teeth. CONCLUSION: This study confirms that children with cystic fibrosis are at increased risk of developing hypoplastic defects on their permanent teeth.


Assuntos
Esmalte Dentário/anormalidades , Estudos de Casos e Controles , Criança , Pré-Escolar , Estudos Transversais , Fibrose Cística/epidemiologia , Hipoplasia do Esmalte Dentário/epidemiologia , Feminino , Humanos , Itália/epidemiologia , Masculino , Prevalência , Descoloração de Dente/epidemiologia
3.
Science ; 260(5106): 293-4, 1993 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-17838240

RESUMO

The Rockies were hidden by clouds, but "Welcome ACS" signs were visible all over the Mile High City from 28 March to 2 April. No wonder the city's boosters were cheering: More than 10,000 scientists, purveyors of laboratory equipment, and other chemophiles had flooded into Denver to take in a vision of chemistry's intellectual scope that was wide enough to compensate for the missing scenic grandeur. In just a tiny sampling of the roughly 4800 presentations, chemistry appears in guises ranging from the most basic molecule making, through cleanup strategies for major environmental challenges, to forensic methods for unraveling a historical mystery.

4.
Science ; 261(5127): 1388-9, 1993 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-17745342

RESUMO

Two times each year, legions of chemists gather in North America for a massive meeting to discuss the state of the art in their science. The second of this year's get-togethers occurred 2 weeks ago, when the 206th national meeting of the American Chemical Society (ACS) drew about 13,000 chemists, scientists, and onlookers to Chicago. Researchers shared 4800 or so papers and posters on everything from making waste plastic into fuel oil to the chemical basis for the stench of ginkgo fruit to modeling the first instants of photosynthesis.

5.
G Ital Nefrol ; 24 Suppl 38: 72-5, 2007.
Artigo em Italiano | MEDLINE | ID: mdl-17922452

RESUMO

Videolaparoscopic surgery exposes the abdominal organs to the mechanical effect of pneumoperitoneum at pressure values between 12 and 15 mm Hg, which are considered safe. Nevertheless, experimental data have shown that this pressure range can represent a hemodynamic risk factor as it may induce a decrease in the venous return to the right ventricle, a decrease in cardiac output, and activation of the sympathetic nervous system and renin angiotensin system. We report two cases of acute renal failure that occurred soon after videolaparoscopy in young female patients without any evidence of ongoing renal disease. Patient A was 29 years old and was submitted to videolaparoscopic surgery in a follow-up program after surgical treatment of ovarian cancer; patient B was 15 years old and was submitted to the surgical removal of a monolateral ovarian cyst. In neither of the cases was it necessary to perform hemodialysis. Patient A underwent a renal biopsy under ultrasound guidance; optic microscopy showed only in ra- and extraglomerular capillary congestion. In both cases the acute renal failure resolved completely and the patients where discharged with normal renal function. Taking in to account that normal renal venous pressure levels are around 4 mmHg we think that a) a 15 mmHg pneumoperitoneum may represent a risk factor during videolaparoscopic surgery mainly if the patient's extracellular volume is not properly expanded; b) administration of nonsteroidal anti-inflammatory drugs in order to prevent surgical pain may inhibit vasodilatory prostaglandin availability; c) onset of oliguria during the surgical procedure suggests that extracellular volume expansion is required.


Assuntos
Injúria Renal Aguda/etiologia , Laparoscopia/efeitos adversos , Cirurgia Vídeoassistida/efeitos adversos , Injúria Renal Aguda/terapia , Adolescente , Adulto , Feminino , Hidratação/métodos , Humanos , Cistos Ovarianos/cirurgia , Neoplasias Ovarianas/cirurgia , Pneumoperitônio/complicações , Remissão Espontânea , Fatores de Risco , Resultado do Tratamento
6.
Biochim Biophys Acta ; 1416(1-2): 57-68, 1999 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-9889319

RESUMO

Microcompartmentalization is a crucial step in the origin of life. More than 30 years ago, Oparin et al. proposed models based on biochemical reactions taking place in so-called coacervates. Their intention was to develop systems with which semipermeable microcompartments could be established. In the present work we follow their intuition, but we use well-characterized bilayer structures instead of the poorly characterized coacervates. Liposomes from phospholipids can be used as microreactors but they exhibit only a modest permeability and, therefore, chemical reactions occurring inside these structures are depleted after a relatively short period. Here it is shown that even highly stable liposomes from 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) can be used as semipermeable microreactors when treated with sodium cholate. Using this kind of mixed liposomes, we describe a biochemical reaction occurring inside the liposomes while the same reaction is prevented in the external medium. In addition, we show that this cholate-induced permeability of POPC bilayers can even be used to load macromolecules such as enzymes from the outside.


Assuntos
Detergentes , Lipossomos/química , Colatos , Desoxirribonuclease I/química , Glicogênio/síntese química , Substâncias Macromoleculares , Métodos , Permeabilidade , Fosfatidilcolinas , Fosforilases/química
7.
Biomaterials ; 25(18): 4037-45, 2004 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15046894

RESUMO

Particle-induced macrophage activation, mainly by UHMWPE wear, has been recognized as the biological mechanism leading to periprosthetic bone resorption, which is responsible for the loosening of the total hip replacements (THR). Ceramic-on-ceramic implants have been advocated as a means of reducing wear products. Many studies investigated the effect of alumina (Al(2)O(3)) particles on monocytes/macrophages, but only limited information are available on their participation to bone turnover. An in vitro model was performed to investigate how Al(2)O(3) and UHMWPE particles may influence the osteoblast-osteoclast interaction: human osteoblasts (HOB) were obtained from trabecular bone, while osteoclasts were derived from peripheral blood mononuclear cells (PBMC) of healthy donors. The amount of IL6, TNF alpha, GM-CSF, and other factors acting on the bone turnover, i.e. the 'receptor activator of NF kappa B' ligand (RANKL) and osteoprotegerin (OPG), was detected in culture medium of particle-challenged HOB (HOB-CM). The Al(2)O(3) and UHMWPE particles did not affect either cell viability or TNF and GM-CSF release, while the increase in IL6 release seemed to be dependent on the particle concentration. UHMWPE increased the release of RANKL from HOB, while OPG and OPG-to-RANKL ratio were significantly inhibited. The ability of HOB-CM to promote osteoclastogenesis was tested via osteoblast/monocyte cooperation: after seven days of culture UHMWPE HOB-CM induced a large amount of multinucleated TRAP-positive giant cells, as well as significantly reduced the amount of IL6, GM-CSF and RANKL in the supernatant. With regard to the inductive effect on the osteoclastogenesis, our results show that the Al(2)O(3) wear debris are less active.


Assuntos
Óxido de Alumínio/química , Técnicas de Cocultura/métodos , Corpos Estranhos/patologia , Osteoblastos/patologia , Osteoclastos/patologia , Polietilenos/química , Materiais Biocompatíveis/química , Diferenciação Celular , Sobrevivência Celular , Células Cultivadas , Citocinas/metabolismo , Análise de Falha de Equipamento , Corpos Estranhos/etiologia , Corpos Estranhos/metabolismo , Humanos , Teste de Materiais , Osteoblastos/metabolismo , Osteoclastos/metabolismo , Tamanho da Partícula , Falha de Prótese , Infecções Relacionadas à Prótese/etiologia , Infecções Relacionadas à Prótese/metabolismo , Infecções Relacionadas à Prótese/patologia
11.
Science ; 260(5104): 22, 1993 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-17793518
12.
Science ; 259(5098): 1122, 1993 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-17794390
13.
Science ; 259(5096): 765, 1993 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-17809337
14.
Science ; 260(5110): 895, 1993 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-17818379
15.
Science ; 261(5118): 153, 1993 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-17829259
16.
Science ; 261(5118): 165, 1993 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-17829267
17.
Science ; 259(5093): 306-8, 1993 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-17832336
18.
Science ; 259(5093): 307, 1993 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-17832337
19.
Science ; 259(5093): 308, 1993 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-17832338
20.
Science ; 259(5093): 311, 1993 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-17832339
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa