Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 170
Filtrar
1.
Rev Med Chil ; 147(8): 993-996, 2019 Aug.
Artigo em Espanhol | MEDLINE | ID: mdl-31859963

RESUMO

BACKGROUND: Treatment of spine bone metastases with stereotactic radio-therapy (SBRT) may produce greater pain relief than palliative radiotherapy. AIM: To evaluate the analgesic response to SBRT. MATERIAL AND METHODS: A search was made in an electronic database of all patients treated by SBRT in our center. We found 20 patients that were treated with SBRT in the spine on 24 sites (lesions). Analgesic response was evaluated at 3 and 6 months after SBRT. Other factors such as age, sex, functional status, diagnosis, metastasis location, dosimetry and toxicity of the treatment were also described. RESULTS: The median follow-up was 8.1 months. Complete pain relief occurred at three months in 74% of the treated sites. At three months, 78% of the patients presented a functional status 0 (ECOG). The median dose used was 24 Gy in 2 fractions. No cases of G3 or greater toxicity were recorded. CONCLUSIONS: The analgesic response to SBRT seems to be better than that reported for palliative radiotherapy.


Assuntos
Manejo da Dor/métodos , Radiocirurgia/métodos , Neoplasias da Coluna Vertebral/radioterapia , Neoplasias da Coluna Vertebral/secundário , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Doses de Radiação , Radiocirurgia/efeitos adversos , Estudos Retrospectivos , Neoplasias da Coluna Vertebral/diagnóstico por imagem , Fatores de Tempo , Resultado do Tratamento , Escala Visual Analógica
2.
Luminescence ; 26(5): 331-5, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-20812198

RESUMO

Cigarette smoking plays an important role as a cause of morbidity and mortality in humans, involving respiratory, cardiovascular, digestive and reproductive systems. Tobacco smoke contains a large number of molecules, some of which are proven carcinogens. Although not fully understood, polymorphonuclear leukocytes seem to play a crucial role in the mechanisms by which tobacco smoke compounds are implicated in smoke-related diseases. In this paper the effects of an aqueous cigarette smoke extract on the expression of adhesion molecules of polymorphonuclear leukocytes together with the changes in the cell morphology have been related to the chemiluminescence activity. The results obtained show that polymorphonuclear leukocytes treated with aqueous cigarette smoke extract are significantly impaired, as suggested by the changes of chemiluminescence activity, of membrane receptors (CD18, CD62), myeloperoxidase expression and of cell morphology. Altogether the present data indicate that treated polymorphonuclear leukocytes are ineffectively activated and therefore unable to phagocytize zymosan particles.


Assuntos
Neutrófilos/citologia , Neutrófilos/efeitos dos fármacos , Nicotiana/efeitos adversos , Fumaça/efeitos adversos , Fumar/efeitos adversos , Moléculas de Adesão Celular/genética , Moléculas de Adesão Celular/imunologia , Células Cultivadas , Expressão Gênica/efeitos dos fármacos , Humanos , Medições Luminescentes , Neutrófilos/química , Neutrófilos/imunologia , Fumaça/análise , Fumar/imunologia , Nicotiana/química
3.
Rev Sci Instrum ; 89(5): 052302, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29864837

RESUMO

The conceptual design of a fourth generation hybrid electron cyclotron resonance (ECR) ion source operated at 60 GHz is proposed. The axial magnetic mirror is generated with a set of three Nb3Sn coils, while the hexapole is made with room temperature (RT) copper coils. The motivations for such a hybrid development are to study further the ECR plasma physics and the intense multicharged ion beams' production and transport at a time when a superconducting (SC) hexapole appears unrealistic at 60 GHz. The RT hexapole coil designed is an evolution of the polyhelix technology developed at the French High Magnetic Field Facility. The axial magnetic field is generated by means of 3 Nb3Sn SC coils operated with a maximum current density of 350 A/mm2 and a maximum coil load line factor of 81%. The ECR plasma chamber resulting from the design features an inner radius of 94 mm and a length of 500 mm. The radial magnetic intensity is 4.1 T at the wall. Characteristic axial mirror peaks are 8 and 4.5 T, with 1.45 T minimum in between.

4.
Clin Biochem ; 40(9-10): 661-5, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17328883

RESUMO

OBJECTIVES: Recent studies describe the potential use of biochemical markers in the evaluation of the severity of periodontitis; moreover, patients suffering from periodontitis frequently complain of halitosis (breath malodour), mainly depending on volatile compounds (e.g. hydrogen sulphide, methyl mercaptan, etc.) produced by anaerobic metabolism of oral bacteria and involving sulphur-containing amino acids. In this study, salivary sulphur compounds, such as cysteine, cysteinylglycine and glutathione and some markers of cellular damage (lactate dehydrogenase and aspartate amino transferase), were measured in periodontitis patients and correlated with the periodontal probing pocket's depth. DESIGN AND METHODS: Twenty-two periodontitis patients and forty control subjects were studied for the salivary activities of lactate dehydrogenase and aspartate aminotransferase and cysteine, cysteinylglycine and glutathione concentrations. The periodontitis patients were divided into two subgroups based on the severity of periodontal disease, expressed as median periodontal probing pocket depth (> or <5 mm). Enzyme activities were measured by using an automated clinical analyzer; cysteine, cysteinylglycine and glutathione concentrations were measured by HPLC equipped with fluorescence detector. RESULTS: A statistically significant increase of the salivary parameters level (cysteine, cysteinylglycine, glutathione, aspartate aminotransferase and lactate dehydrogenase) was found in the patient subgroup with periodontal probing pocket depth >5 mm, the salivary cysteine concentrations showing the most significant correlation. CONCLUSIONS: Salivary cysteine, a direct precursor of hydrogen sulphide, could be considered reliable markers for the oral tissue damage severity in periodontitis patients.


Assuntos
Biomarcadores/análise , Periodontite/diagnóstico , Saliva/química , Compostos de Sulfidrila/análise , Adulto , Idoso , Aspartato Aminotransferases/análise , Cisteína/análise , Dipeptídeos/análise , Feminino , Glutationa/análise , Humanos , L-Lactato Desidrogenase/análise , Masculino , Pessoa de Meia-Idade , Bolsa Periodontal/patologia , Saliva/enzimologia
5.
J Dent ; 35(3): 187-94, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16979810

RESUMO

OBJECTIVES: Methacrylic compounds such as 2-hydroxyethyl methacrylate (HEMA), triethylene glycol dimethacrylate (TEGDMA) and bisphenol A glycerolate (1 glycerol/phenol) dimethacrylate (Bis-GMA) are largely present in auto- or photopolymerizable composite resins. Since the polymerization reaction is never complete, these molecules are released into the oral cavity tissues and biological fluids where they could cause local adverse effects. The aim of this work was to verify the hypothesis that the biological effects of HEMA, TEGDMA and Bis-GMA - at a non-cytotoxic concentration - depend on the interaction with mitochondria and exert consequent alterations of energy metabolism, GSH levels and the related pathways in human promyelocytic cell line (HL-60). METHODS: The biological effects of methacrylic monomers were determined by analyzing the following parameters: GSH concentration, glucose-6-phosphate dehydrogenase (G6PDH) and glutathione reductase (GR) activity, oxygen and glucose consumption and lactate production along with cell differentiation and proliferation. RESULTS: All monomers induced both cellular differentiation and decrease in oxygen consumption. Cells treated with TEGDMA and Bis-GMA showed a significant enhancement of glucose consumption and lactate production. TEGDMA and HEMA induced GSH depletion stimulating G6PDH and GR activity. CONCLUSIONS: All the monomers under study affect the metabolism of HL-60 cells and show differentiating activity. Since alterations in cellular metabolism occurred at compound concentrations well below cytotoxic levels, the changes in energy metabolism and glutathione redox balance could be considered as potential mechanisms for inducing clinical and sub-clinical adverse effects and thus providing useful parameters when testing biocompatibility of dental materials.


Assuntos
Resinas Compostas/farmacologia , Materiais Dentários/farmacologia , Metabolismo Energético/efeitos dos fármacos , Glutationa/metabolismo , Metacrilatos/farmacologia , Bis-Fenol A-Glicidil Metacrilato/farmacologia , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Glucose/metabolismo , Glucosefosfato Desidrogenase/efeitos dos fármacos , Glutationa Redutase/efeitos dos fármacos , Células HL-60 , Humanos , Ácido Láctico/metabolismo , Mitocôndrias/efeitos dos fármacos , Consumo de Oxigênio/efeitos dos fármacos , Polietilenoglicóis/farmacologia , Polímeros , Ácidos Polimetacrílicos/farmacologia
6.
Minerva Med ; 97(5): 437-42, 2006 Oct.
Artigo em Inglês, Italiano | MEDLINE | ID: mdl-17146424

RESUMO

Leukocyte adhesion deficiency (LAD) is a rare disorder of cellular immunity, generally due to various mutations producing reduced or altered expression of membrane integrins. The authors report a case of LAD due to integrins expression imbalance. LAD was suspected after recurrent sepsis, fungal infection and amoebiasis with persistent leukocytosis. Neutrophils were studied with chemiluminescence showing decreased functional activity: up to now, this seems the first chemiluminescence study of neutrophil function and the first report of amoebiasis at the onset in LAD.


Assuntos
Antígeno CD11a/análise , Antígeno CD11b/análise , Síndrome da Aderência Leucocítica Deficitária/imunologia , Animais , Candidíase/tratamento farmacológico , Candidíase/imunologia , Entamoeba histolytica/isolamento & purificação , Entamebíase/imunologia , Feminino , Humanos , Lactente , Leucocitose/imunologia , Luminescência , Neutrófilos/imunologia , Recidiva , Sepse/tratamento farmacológico , Sepse/imunologia , Infecções Urinárias/imunologia , Infecções Urinárias/microbiologia
7.
Rev Sci Instrum ; 87(2): 02B508, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26932061

RESUMO

In the framework of the SPIRAL1 upgrade under progress at the GANIL lab, the charge breeder based on a LPSC Phoenix ECRIS, first tested at ISOLDE has been modified to benefit of the last enhancements of this device from the 1+/n+ community. The modifications mainly concern the 1 + optics, vacuum techniques, and the RF-buffer gas injection into the charge breeder. Prior to its installation in the midst of the low energy beam line of the SPIRAL1 facility, it has been decided to qualify its performances and several operation modes at the test bench of LPSC lab. This contribution shall present preliminary results of experiments conducted at LPSC concerning the 1 + to n+ conversion efficiencies for noble gases as well as for alkali elements and the corresponding transformation times.

8.
Rev Sci Instrum ; 87(2): 02A733, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26931951

RESUMO

The SPIRAL2 injector, installed in its tunnel, is currently under commissioning at GANIL, Caen, France. The injector is composed of two low energy beam transport lines: one is dedicated to the light ion beam production, the other to the heavy ions. The first light ion beam, created by a 2.45 GHz electron cyclotron resonance ion source, has been successfully produced in December 2014. The first beam of the PHOENIX V2 18 GHz heavy ion source was analyzed on 10 July 2015. A status of the SPIRAL2 injector commissioning is given. An upgrade of the heavy ion source, named PHOENIX V3 aimed to replace the V2, is presented. The new version features a doubled plasma chamber volume and the high charge state beam intensity is expected to increase by a factor of 1.5 to 2 up to the mass ∼50. A status of its assembly is proposed.

9.
Cell Death Differ ; 6(8): 781-7, 1999 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10467352

RESUMO

Bezafibrate belongs to the class of fibric acid derivatives usually used as antihyperlipidemia agents. From the biochemical point of view, these drugs show intriguing properties which leads one to think they may promote a differentiation process in tumour cells. This new pharmacological activity of fibrates could partially depend on the induction of an oxidative stress. To test this hypothesis, the effect of bezafibrate, as well as of clofibric acid and gemfibrozil, on growth, functional and cytochemical characteristics of human leukaemia-derived cell lines HL-60, U-937 and K-562 has been studied in some details. The results show that bezafibrate, gemfibrozil and clofibric acid, do induce differentiation in human myeloid leukaemia cell lines as indicated by several differentiation markers. Moreover fibrates, in dose dependent manner, significantly alter the cell cycle distributions, mainly leading to G0/G1 phase increment and G2/M phase reduction. The differentiating activity of fibrates could have significant implications both for the pharmacotoxicological profile of this class of compounds and for the pathophysiology of neoplastic disease.


Assuntos
Antineoplásicos/farmacologia , Bezafibrato/farmacologia , Inibidores do Crescimento/farmacologia , Acetilcisteína/farmacologia , Antioxidantes/farmacologia , Biomarcadores , Ciclo Celular/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Ácido Clofíbrico/análogos & derivados , Genfibrozila/farmacologia , Células HL-60 , Humanos , Integrina alfaXbeta2/biossíntese , Células K562 , Leucemia Mieloide , Receptores de Lipopolissacarídeos/biossíntese , Células U937
10.
Thromb Res ; 61(4): 395-401, 1991 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-2063347

RESUMO

Lactic dehydrogenase (LDH) of isolated platelets was determined in a group of 103 normally pregnant and 19 unpregnant women. LDH activity is significantly increased in the last trimester of pregnancy while the isoenzyme pattern does not vary in relation to LDH increase. Moreover, glucose consumption and lactic acid production are linearly correlated to platelet LDH activity.


Assuntos
Plaquetas/metabolismo , Glicólise/fisiologia , L-Lactato Desidrogenase/metabolismo , Lactatos/análise , Gravidez/metabolismo , Adulto , Feminino , Idade Gestacional , Humanos , Isoenzimas , Ácido Láctico
11.
Free Radic Res ; 35(5): 499-505, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11767408

RESUMO

High plasma homocysteine concentrations have been found to be associated with atherosclerosis and thrombosis of arteries and deep veins. The oxidative damage mediated by hydrogen peroxide production during the metal-catalyzed oxidation of homocysteine is to date considered to be one of the major pathophysiological mechanisms for this association. In this work, a very sensitive and accurate method was employed to measure the effective production of H2O2 during homocysteine oxidation. Furthermore, the interaction of homocysteine with powerful oxidizing species (hypochlorite, peroxynitrite, ferrylmyoglobin) was evaluated in order to ascertain the putative pro-oxidant role of homocysteine. Our findings indicate that homocysteine does not produce H2O2 in a significant amount (1/4000 mole/mole ratio of H2O2 to homocysteine). Moreover, homocysteine strongly inhibits the oxidation of luminol and dihydrorhodamine by hypochlorite or peroxynitrite and rapidly reduces back ferrylmyoglobin, the oxidizing species, to metmyoglobin. All these results should, in our opinion, lead to a rethinking of the commonly held view that homocysteine oxidation is one of the main causative mechanisms of cardiovascular damage.


Assuntos
Homocisteína/metabolismo , Oxidantes/metabolismo , Animais , Arteriosclerose/etiologia , Humanos , Peróxido de Hidrogênio/metabolismo , Hiper-Homocisteinemia/complicações , Hiper-Homocisteinemia/metabolismo , Técnicas In Vitro , Cinética , Medições Luminescentes , Metamioglobina/metabolismo , Oxirredução , Ácido Peroxinitroso/metabolismo , Trombose/etiologia
12.
Int J Antimicrob Agents ; 13(3): 197-201, 2000 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10724024

RESUMO

The present study was designed to evaluate the antibacterial and antioxidant activities of an aqueous extract from the tropical Feijoa sellowiana Berg. fruit which is widely used for human food. The extract was tested against gram-positive and gram-negative bacteria by a broth dilution test and on human whole blood leukocytes, as well as isolated neutrophils using a chemiluminescence (CL) assay. The extract inhibited bacterial growth; Pseudomonas aeruginosa, Enterobacter aerogenes and Enterobacter cloacae were the most sensitive. The fruit extract significantly decreased CL emission from human whole blood phagocytes and isolated polymorphonuclear leukocytes whether they were activated or not by soluble or phagocytic stimuli. F. sellowiana showed both antibacterial and antioxidant properties and therefore its extract might be used as a new multifaceted drug.


Assuntos
Antibacterianos/farmacologia , Antioxidantes/farmacologia , Frutas/química , Plantas Medicinais/química , Antibacterianos/química , Antioxidantes/química , Enterobacter/efeitos dos fármacos , Humanos , Técnicas In Vitro , Indicadores e Reagentes , Medições Luminescentes , Luminol , Testes de Sensibilidade Microbiana , Neutrófilos/efeitos dos fármacos , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Pseudomonas/efeitos dos fármacos , Staphylococcus/efeitos dos fármacos , Streptococcus/efeitos dos fármacos
13.
Clin Chim Acta ; 266(2): 173-83, 1997 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-9437545

RESUMO

Gemfibrozil is an antihyperlipidaemia agent used in therapy to reduce the occurrence of coronary heart disease. Considering the biochemical and pharmacological peculiarities of this class of drugs, we investigated the influence of a single oral therapeutic dose of gemfibrozil on the reactive oxygen metabolism of phagocytic leucocytes. Analysis was carried out adopting a chemiluminescence assay. Results clearly indicate that gemfibrozil, acting as a primer, significantly enhances the induced reactive-oxygen-species (ROS) production by overall blood phagocytes (increment of Stimulation Index (SI) = +52% with respect to time 0 values; P < 0.01), by polymorphonuclear leucocytes (increment of SI = +28% with respect to control values; P < 0.01) and by monocytes (increment of SI = +83% with respect control values; P < 0.001), when these cells are stimulated by phorbol myristate acetate. This iatrogenic derangement of ROS metabolism could explain, at least in part, the occurrence of some side effects that occur in treatment with fibrates.


Assuntos
Genfibrozila/farmacologia , Hipolipemiantes/farmacologia , Neutrófilos/efeitos dos fármacos , Neutrófilos/metabolismo , Fagócitos/efeitos dos fármacos , Fagócitos/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Adulto , Humanos , Masculino , Pessoa de Meia-Idade , Monócitos/efeitos dos fármacos , Monócitos/metabolismo , Estimulação Química , Acetato de Tetradecanoilforbol/farmacologia
14.
Clin Chim Acta ; 310(2): 187-91, 2001 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-11498084

RESUMO

BACKGROUND: Breath condensate can give useful information on volatile compounds produced at alveolar level. Actual concentration of H(2)O(2) in breath condensate is dependent on its production at alveolar level and on the efficacy of the detoxifying systems, catalase, glutathione peroxidase, etc. METHODS: In the present paper, a simple chemiluminescent method for the determination of the H(2)O(2) collected in exhaled breath is shown and data of both smokers and nonsmokers volunteers are presented. RESULTS: The chemiluminescent response is linear up to 100 micromol/l H(2)O(2). The analytical sensitivity is about 0.01 micromol/l. Most of the nonsmokers have a H(2)O(2) content lower than 0.05 micromol/l, while smokers have a content ranging from 0.1 to 0.6 micromol/l.


Assuntos
Peróxido de Hidrogênio/análise , Medições Luminescentes , Respiração , Adulto , Humanos , Pessoa de Meia-Idade , Alvéolos Pulmonares/metabolismo , Valores de Referência , Sensibilidade e Especificidade , Fumar/metabolismo
15.
Diabetes Res Clin Pract ; 46(2): 127-34, 1999 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-10724091

RESUMO

The concentration of some of the purine nucleotides and their metabolites together with that of malondialdehyde (MDA) have been measured in resting and stimulated platelets of type 1 and type 2 diabetic patients. While control platelets show a net decrease of guanosine triphosphate (GTP) (3.1 vs. 2.3 nmol per 10(9) platelets) and guanosine diphosphate (GDP) (3.0 vs. 2.0 nmol per 10(9) platelets) and a significant increase of adenosine (0.04 vs. 0.55 nmol per 10(9) platelets) with platelet stimulation, platelets of type 1 and type 2 diabetic patients have a lesser change of these metabolites (GTP, 2.6 vs. 2.4; GDP, 2.3 vs. 2.4; adenosine, 0.04 vs. 0.30 (P < 0.05 vs. control) nmol per 10(9) platelets in type 1 diabetics; GTP, 2.4 vs. 2.7; GDP, 2.4 vs. 2.1; adenosine, 0.08 vs. 0.32 (P < 0.05 vs. control) nmol per 10(9) platelets in type 2 diabetics). These results indicate that the change (stimulated minus resting) of GTP, GDP and adenosine in diabetic platelets is significantly different from that of controls (P < 0.001). Moreover, the amount of MDA produced during platelet activation seems to be lower than controls only in type 2 diabetes (1.81 vs. 2.86 nmol per 10(9) platelets, P < 0.05). These results seem to indicate that a difference in the pattern of platelet nucleotides could be an important feature even in well-controlled diabetes, while MDA is probably modified only in association with the late vascular complications of diabetes.


Assuntos
Plaquetas/metabolismo , Diabetes Mellitus Tipo 1/sangue , Diabetes Mellitus Tipo 2/sangue , Malondialdeído/sangue , Purinas/metabolismo , Adenosina/sangue , Monofosfato de Adenosina/sangue , Adolescente , Adulto , Idoso , Feminino , Nucleotídeos de Guanina/sangue , Humanos , Masculino , Pessoa de Meia-Idade , Valores de Referência
16.
Arch Immunol Ther Exp (Warsz) ; 40(1): 55-8, 1992.
Artigo em Inglês | MEDLINE | ID: mdl-1485828

RESUMO

The chemiluminescence of alveolar macrophages was determined in presence of luminol or lucigenin, either before or after the macrophage isolation by adherence to plastic. In presence of luminol, the purified and non-purified macrophages behave almost in the same way, and their chemiluminescence activity is stimulated both by zymosan and phorbol ester. On the other hand, the lucigenin chemiluminescence of non-purified macrophages is considerably higher than that obtained in presence of luminol, but is almost completely insensitive to the zymosan or phorbol ester stimulation. Moreover, the adherence purification considerably inhibits the lucigenin chemiluminescence. These results can be indicative of functionally different macrophage states.


Assuntos
Adesão Celular , Medições Luminescentes , Macrófagos Alveolares/fisiologia , Sarcoidose/patologia , Acridinas , Adulto , Líquido da Lavagem Broncoalveolar/citologia , Células Cultivadas , Feminino , Humanos , Luminol , Ativação de Macrófagos/efeitos dos fármacos , Macrófagos Alveolares/efeitos dos fármacos , Masculino , Pessoa de Meia-Idade , Plásticos , Acetato de Tetradecanoilforbol/farmacologia , Zimosan/farmacologia
17.
Arch Oral Biol ; 44(6): 485-8, 1999 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10401526

RESUMO

Concentrations of glutathione, uric acid and total antioxidant activity, expressed as Trolox (a water-soluble vitamin E analogue) equivalent, were measured in the saliva of healthy non-smokers and smokers before and just after smoking a single cigarette. There was no statistically significant difference between smokers and non-smokers in uric acid concentrations and total radical-trapping antioxidant capacity, but glutathione concentrations were significantly (p < 0.05) higher in smokers. Smoking of a single cigarette induced a significant reduction in glutathione concentration (p < 0.05). Salivary antioxidant power may affect individual sensitivity toward tobacco stress.


Assuntos
Antioxidantes/metabolismo , Saliva/metabolismo , Fumar/metabolismo , Adulto , Benzotiazóis , Cromatografia Líquida de Alta Pressão , Feminino , Sequestradores de Radicais Livres/metabolismo , Glutationa/metabolismo , Humanos , Indicadores e Reagentes , Masculino , Pessoa de Meia-Idade , Peroxidase/metabolismo , Ácidos Sulfônicos , Ácido Úrico/metabolismo
18.
IEEE Trans Image Process ; 3(4): 367-81, 1994.
Artigo em Inglês | MEDLINE | ID: mdl-18291937

RESUMO

Introduces a new image coding scheme using lattice vector quantization. The proposed method involves two steps: biorthogonal wavelet transform of the image, and lattice vector quantization of wavelet coefficients. In order to obtain a compromise between minimum distortion and bit rate, we must truncate and scale the lattice suitably. To meet this goal, we need to know how many lattice points lie within the truncated area. We investigate the case of Laplacian sources where surfaces of equal probability are spheres for the L(1) metric (pyramids) for arbitrary lattices. We give explicit generating functions for the codebook sizes for the most useful lattices like Z(n), D(n), E(s), wedge(16).

19.
Drugs Exp Clin Res ; 11(8): 529-32, 1985.
Artigo em Inglês | MEDLINE | ID: mdl-3015540

RESUMO

The ability of different homologues of Coenzyme Q to quench O2- was tested in vitro with three experimental systems known to generate O2-. Two of them were biological generators, namely the xanthine-xanthine oxidase system and the cyanide-insensitive NADPH oxidase of polymorphonuclear leucocytes. The third was a chemical generator of O2-, the NADH-phenazine methosulphate-nitroblue tetrazolium mixture. Short-side-chain ubiquinones were found to be the most potent scavengers of O2-, being effective at concentrations as low as 10(-7) M. This finding might be ascribed to the relatively greater water-solubility of the lower homologues of CoQ. We postulate that CoQ10 may well exert such an O2- -scavenging mechanisms in vivo where it is inserted in its natural phospholipid environment.


Assuntos
Superóxidos/metabolismo , Ubiquinona/análogos & derivados , Humanos , Técnicas In Vitro , Medições Luminescentes , Metilfenazônio Metossulfato , NAD , NADH NADPH Oxirredutases/metabolismo , NADPH Oxidases , Neutrófilos/metabolismo , Nitroazul de Tetrazólio , Ubiquinona/farmacologia , Xantina Oxidase/metabolismo , Xantinas/metabolismo
20.
Artigo em Inglês | MEDLINE | ID: mdl-2609883

RESUMO

Metabolic burst of polymorphonuclear leukocytes was evaluated by means of a luminol-enhanced chemiluminescence assay. Patients affected with active psoriasis showed a higher response than patients with chronic disease and controls when the neutrophils were stimulated with opsonized zymosan or phorbol myristate acetate.


Assuntos
Neutrófilos/metabolismo , Psoríase/metabolismo , Adulto , Idoso , Doença Crônica , Feminino , Humanos , Medições Luminescentes , Masculino , Pessoa de Meia-Idade , Neutrófilos/fisiologia , Psoríase/sangue , Acetato de Tetradecanoilforbol/metabolismo , Zimosan/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA