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1.
Reprod Domest Anim ; 50(5): 807-11, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26280798

RESUMO

The pregnancy rates obtained after the transfer of cryopreserved in vitro-produced (IVP) embryos are usually low and/or inconsistent. The objective of this study was to evaluate the pregnancy rates of Holstein, Gyr and Holstein × Gyr cattle after the transfer of vitrified IVP embryos produced with X-sorted sperm. Seventy-two Gyr and 703 Holstein females were subjected to ovum pickup (OPU) sessions, followed by in vitro embryo production using semen from sires of the same breeds. Embryos (1636 Holstein, 241 Gyr and 1515 Holstein × Gyr) were exposed to forskolin for 48 h prior to vitrification. The pregnancy rate achieved with Gyr dam and sire was 46.1%, which was similar (p = 0.11) to that of Holstein dam and Gyr sire (40.3%). Crossing Gyr dams with Holstein sires resulted in a pregnancy rate of 38.9% and did not differ (p = 0.58) from the pregnancy rate obtained with the cross between Holstein dams and Gyr sires. The rate obtained with Holstein dam and sire was 32.5%. The average pregnancy rate was 36.6%, and no difference was found in the proportion of female foetuses (88.8%, in average) among breeds (p > 0.05). In conclusion, transfer of cryopreserved X-sorted embryos represents an interesting choice for dairy cattle. Despite the small differences between pregnancy rates, we highlight the efficiency of this strategy for all of the racial groups studied.


Assuntos
Bovinos/embriologia , Criopreservação/veterinária , Transferência Embrionária/veterinária , Fertilização in vitro/veterinária , Taxa de Gravidez , Animais , Cruzamento , Bovinos/genética , Bovinos/fisiologia , Transferência Embrionária/métodos , Feminino , Temperatura Alta , Masculino , Gravidez , Pré-Seleção do Sexo/veterinária , Especificidade da Espécie , Espermatozoides
2.
Comput Methods Programs Biomed ; 110(3): 399-410, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23357405

RESUMO

RADStation3G is a software platform for cardiovascular image analysis and surgery planning. It provides image visualization and management in 2D, 3D and 3D+t; data storage (images or operational results) in a PACS (using DICOM); and exploitation of patients' data such as images and pathologies. Further, it provides support for computationally expensive processes with grid technology. In this article we first introduce the platform and present a comparison with existing systems, according to the platform's modules (for cardiology, angiology, PACS archived enriched searching and grid computing), and then RADStation3G is described in detail.


Assuntos
Técnicas de Diagnóstico Cardiovascular/estatística & dados numéricos , Imageamento Tridimensional/estatística & dados numéricos , Modelos Cardiovasculares , Software , Simulação por Computador , Diagnóstico por Computador/estatística & dados numéricos , Humanos , Terapia Assistida por Computador/estatística & dados numéricos
3.
Theriogenology ; 74(8): 1349-55, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20708245

RESUMO

Herein we describe a large-scale commercial program for in vitro production of embryos from dairy Bos taurus, Bos indicus, and indicus-taurus donors, using sexed sperm. From 5,407 OPU, we compared the number of recovered oocytes (n = 90,086), viable oocytes (n = 64,826), and embryos produced in vitro from Gir (Bos indicus, n = 617), Holstein (Bos taurus, n = 180), 1/4 Holstein × 3/4 Gir (n = 44), and 1/2 Holstein-Gir (n = 37) crossbred cows, and the pregnancy rate of recipient cows. Viable oocytes were in vitro matured (24 h at 38.8 °C, 5% CO(2) in air) and fertilized by incubating them for 18 to 20 h with frozen-thawed sexed sperm (X-chromosome bearing) from Gir (n = 8) or Holstein (n = 7) sires (2 × 10(6) sperm/dose). Embryos were cultured in similar conditions of temperature and atmosphere as for IVM, with variable intervals of culture (between Days 2 and 5) completed in a portable incubator. All embryos were transferred fresh, after 24 to 72 h of transportation (up to 2,000 km). On average, 16.7 ± 6.3 oocytes (mean ± SEM) were obtained per OPU procedure and 72.0% were considered viable. Total and viable oocytes per OPU procedure were 17.1 ± 4.5 and 12.1 ± 3.9 for Gir cows, 11.4 ± 3.9 and 8.0 ± 2.7 for Holstein cows, 20.4 ± 5.8 and 16.8 ± 5.0 for 1/4 Holstein × 3/4 Gir, and 31.4 ± 5.6 and 24.3 ± 4.7 for 1/2 Holstein-Gir crossbred females (P < 0.01). The mean number of embryos produced by OPU/IVF and the pregnancy rates were 3.2 (12,243/ 3,778) and 40% for Gir cows, 2.1 (2,426/1,138) and 36% for Holstein cows, 3.9 (1,033/267) and 37% for 1/4 Holstein × 3/4 Gir, and 5.5 (1,222/224), and 37% for 1/2 Holstein-Gir. In conclusion, we compared oocyte yield from two levels of indicus-taurus breeds and demonstrated the efficiency of sexed sperm for in vitro embryo production. Culturing embryos during long distance transportation was successful, with potential for international movement of embryos.


Assuntos
Bovinos/embriologia , Técnicas de Cultura Embrionária/veterinária , Fertilização in vitro/veterinária , Análise para Determinação do Sexo/veterinária , Espermatozoides , Animais , Transferência Embrionária/veterinária , Feminino , Masculino , Gravidez , Taxa de Gravidez
6.
Pharmacol Biochem Behav ; 77(3): 481-9, 2004 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15006458

RESUMO

Anxiolytic properties may be a crucial feature of newer antipsychotics associated with the improvement of negative symptoms in schizophrenic patients. The indole alkaloid alstonine acts as an atypical antipsychotic in behavioral models, but differs in its dopamine and serotonin binding profile. The purpose of this study was to verify if alstonine possesses anxiolytic properties in mice. The hole-board and light/dark models were used; moreover, the participation of D(1), 5-HT(2), NMDA and gamma-aminobutyric acid (GABA) receptors was likewise investigated. Alstonine clearly behaves as anxiolytic in both hole-board and light/dark situations. Pretreatment with the 5-HT(2A/2C) serotonin receptor antagonist ritanserin reverted the effects of alstonine in both the hole-board and light/dark models, suggesting the involvement of these receptors in the alstonine mechanism of action. The involvement of glutamate NMDA receptors should also be considered, given that alstonine partially reversed the increase in locomotion induced by MK-801 in the hole board, as well as MK-801-induced hyperlocomotion in motor activity apparatus.


Assuntos
Alcaloides/farmacologia , Ansiolíticos/farmacologia , Antipsicóticos/farmacologia , Alcaloides de Triptamina e Secologanina/farmacologia , Alcaloides/uso terapêutico , Animais , Ansiolíticos/uso terapêutico , Antipsicóticos/uso terapêutico , Ansiedade/tratamento farmacológico , Ansiedade/psicologia , Escuridão/efeitos adversos , Relação Dose-Resposta a Droga , Iluminação/métodos , Locomoção/efeitos dos fármacos , Locomoção/fisiologia , Masculino , Camundongos , Alcaloides de Triptamina e Secologanina/uso terapêutico
7.
Transplant Proc ; 35(8): 3111-5, 2003 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-14697991

RESUMO

The assessment of kidney viability before transplantation (with a view of discarding nonviable organs) remains an obstacle to confidently extending organ harvesting to marginal donors. In the present study phosphorus magnetic resonance spectroscopy was used to monitor metabolic changes in (31)P-containing metabolites in isolated porcine kidneys. After various warm ischemia times, the organs were stored at 0 degrees C. Time-dependent changes in the phosphomonoester/inorganic-phosphate ratio were recorded at 0 degrees C were shown to follow a biexponential decay. The first-order kinetic rate constant of the short-time decay was strongly dependent on the warm ischemia time, a result that was discreted in terms of the underlying biochemistry. The metabolic events responsible for the dramatic decrease in phosphomonoester/inorganic phosphate ratio that occur immediately after organ perfusion and storage, suggest that any procedure to minimize organ damage must occur immediately after harvesting.


Assuntos
Isquemia/metabolismo , Rim/metabolismo , Fósforo/metabolismo , Circulação Renal/fisiologia , Animais , Modelos Animais de Doenças , Rim/irrigação sanguínea , Cinética , Espectroscopia de Ressonância Magnética , Radioisótopos de Fósforo , Técnica de Diluição de Radioisótopos , Suínos
8.
Protein Expr Purif ; 23(2): 261-9, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11676601

RESUMO

The isoenzyme I of cytosolic Cu,Zn-superoxide dismutase (SOD) from Nicotiana plumbaginifolia (tobacco) leaves has been purified to apparent homogeneity. The relative molecular mass of the native isoenzyme, determined by gel filtration chromatography, is about 33.2 kDa. SDS-polyacrylamide gel electrophoresis shows that the enzyme is composed of two equal subunits of 16.6 kDa The isolectric point, assayed by isoelectric focusing, in the pH range of 3.5-6.5, is 4.3. The enzyme stability was tested at different temperatures, pH, and concentration of inhibitors (KCN and H(2)O(2)). The catalytic constant (k(cat)) was 1.17 +/- 0.14 x 10(9) M(-1) s(-1) at pH 9.9 and 0.1 M ionic strength. The activation energy of the thermal denaturation process is 263 kJ mol(-1). The electrostatic surface potential of the modeled tobacco Cu,Zn-SOD I was calculated showing that the functional spatial network of charges on the protein surface has been maintained, independently of the amino acid substitution around the active sites.


Assuntos
Nicotiana/enzimologia , Superóxido Dismutase/química , Sequência de Aminoácidos , Animais , Sítios de Ligação , Bovinos , Citosol/enzimologia , Eletroquímica , Eletroforese em Gel de Poliacrilamida , Inibidores Enzimáticos/farmacologia , Estabilidade Enzimática , Fluoretos/metabolismo , Temperatura Alta , Concentração de Íons de Hidrogênio , Ponto Isoelétrico , Isoenzimas/antagonistas & inibidores , Isoenzimas/química , Isoenzimas/isolamento & purificação , Isoenzimas/metabolismo , Dados de Sequência Molecular , Peso Molecular , Folhas de Planta/enzimologia , Superóxido Dismutase/antagonistas & inibidores , Superóxido Dismutase/isolamento & purificação , Superóxido Dismutase/metabolismo , Propriedades de Superfície
9.
Transplantation ; 71(11): 1515-7, 2001 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-11435958

RESUMO

BACKGROUND: The development of reliable methods for assessing the viability of currently available livers is expected to increase the number of successful transplantations. METHODS: 2 H nuclear magnetic resonance (NMR) was used to search for metabolic markers of ischemia in explanted rat livers. Deuterium oxide (2 H2O) was used as a source of 2 H. A total of 10-80% v/v 2 H2O was added to homogenates obtained from a liver biopsy and the formation of 2 H-labeled metabolites was monitored. RESULTS: Some well-resolved 2 H resonances were found in the homogenates from biopsies of warm ischemic liver. Two of these were identified as [3-2 H] lactate and [2-2 H] lactate, and a linear relationship was found between the ratio of [[2-2 H] lactate] to [[3-2 H] lactate] and the warm ischemia time. The deuterium incorporation into lactate was explained on the basis of the metabolic events occurring under hypoxic conditions. CONCLUSIONS: The experimental results support the application of 2 H NMR for a reliable evaluation of the metabolic status of a liver harvested from non-heart-beating donors.


Assuntos
Isquemia/metabolismo , Circulação Hepática , Fígado/metabolismo , Animais , Deutério , Técnicas In Vitro , Ácido Láctico/metabolismo , Espectroscopia de Ressonância Magnética , Ratos , Ratos Wistar , Fatores de Tempo
10.
J Cancer Educ ; 16(1): 12-4, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11270892

RESUMO

BACKGROUND: Considerations of moral problems in palliative medicine often deal with extreme situations. This study identified moral issues arising in routine palliative medicine. Their relevance for the education of European general practitioners is assessed. METHODS: Consecutive consultations of cancer patients with incurable disease were recorded in three outpatient clinics and one general practice in Belgium. Moral issues were identified by qualitative analysis of verbal transcripts of 30 of these consultations using the grounded-theory approach. The relevance of these issues for medical education was assessed by interviewing one educator of general practitioners from each of the 15 European Union states. RESULTS: Three core categories of moral issues were identified: telling the truth, patient control versus medical dominance, and handling the patient's life-world. The practical relevance of these issues was recognized by the educators. The suggested educational methods to deal with these topics were all active learning processes in small-group settings but varied otherwise. CONCLUSIONS: The moral issues identified in day-to-day palliative medicine may complement the problems evoked in the literature dealing with more extreme situations. An effort to study the appropriate way for medical education to deal with these topics may be indicated.


Assuntos
Medicina de Família e Comunidade/educação , Princípios Morais , Cuidados Paliativos , Europa (Continente) , Humanos
11.
Free Radic Res ; 35(6): 933-9, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11811544

RESUMO

A stable ESR signal, centred at g = 2.0037 +/- 0.0002, characterised by a single resonance and assignable to a free radical, was found in all the bottled red wines, both commercial and experimental, that we have examined. The radical concentration was calculated to be in the range of 5-82 nM. After exposure of the wines to air for a few minutes a two fold increase of the ESR signal, followed by a slow decrease with time, was observed. The intensity of ESR signal in experimental red wines, was found to increase with the ageing of the wines and was strictly correlated to the total content of polyphenols. The formation of semiquinone radicals of polyphenols is suggested as one possible mechanism leading to the presence of stable free radicals in red wines.


Assuntos
Flavonoides , Radicais Livres/análise , Radicais Livres/química , Vinho/análise , Espectroscopia de Ressonância de Spin Eletrônica , Humanos , Fenóis/análise , Fenóis/química , Polímeros/análise , Polímeros/química , Polifenóis , Fatores de Tempo
12.
J Agric Food Chem ; 48(6): 1996-2002, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10888488

RESUMO

Highly reactive radicals, ROO(*), were generated from 2, 2'-azobis[2-(2-imidazolin-2-yl)propane] and linoleic acid. The ROO(*) scavenging capacity of some Italian red wines was evaluated following the changes in oxygen consumption. Under the experimental conditions the time course of oxygen consumption shows two typical behaviors: trolox-like (class I) and gallic acid-like (class II). Usually the time course of wine was similar to that of gallic acid. The rate of oxygen consumption was found to decrease exponentially with the amount of wine or gallic acid added to the test solution. On this basis the capacity of red wines to scavenge peroxy radicals was expressed as content of gallic acid (S(GA)). The S(GA) values were found to be correlated to the amount of total proanthocyanidins and total polyphenols of some Italian red wines (p < 0.01). The proanthocyanidins extracted from seeds were shown to make a major contribution to the peroxy radical scavenging capacity of red wines, whereas, interestingly, the chemical class of the low molecular weight tannins reactive to vanillin did not correlate with the S(GA) values.


Assuntos
Antocianinas/química , Antioxidantes , Sequestradores de Radicais Livres , Peróxidos/química , Proantocianidinas , Vinho , Itália
13.
Biotechnol Bioeng ; 68(5): 488-95, 2000 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-10797234

RESUMO

Active uniform films of horseradish peroxidase (HRP) have been prepared by covalent binding on Si/SiO(2) or glass supports previously activated by silanization and succinylation. Labeling by fluorescent or by Electron Spin Resonance (ESR) probes was used to quantify the surface density of active groups and of horseradish peroxidase. Atomic Force Microscopy (AFM) imaging was used to characterize the surface morphology. We observed that a non-uniform protein adsorption due to physical interactions was present when the supports were not activated for covalent binding and was, in large part, removed by washing. The enzyme deposited by covalent binding formed homogeneous layers with a height in the range 60-90 A. By using a fluorescent label, we calculated a protein density of 3.6 x 10(12) molecules cm(-2) on Si/SiO(2), corresponding to an estimated area per molecule of 2800 A(2) which is in agreement with the value expected on the basis of the crystallographic data considering the formation of a monomolecular layer. The protein density of the layer immobilized on glass was similar (1.9 x10(12) molecules cm(-2)). The enzyme immobilized on both supports showed a k(cat)/K(M) being of the order of 3-5x10(5) M(-1)s(-1) that is 1/20th of free HRP. The half-life time of the activity of the enzyme immobilized by covalent binding was longer than 40 days at 6 degrees C.


Assuntos
Enzimas Imobilizadas/química , Enzimas Imobilizadas/metabolismo , Peroxidase do Rábano Silvestre/química , Peroxidase do Rábano Silvestre/metabolismo , Bis-Fenol A-Glicidil Metacrilato , Catálise , Espectroscopia de Ressonância de Spin Eletrônica , Estabilidade Enzimática , Microscopia de Força Atômica/métodos , Espectrometria de Fluorescência , Propriedades de Superfície
14.
J Pept Res ; 54(6): 491-504, 1999 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-10604594

RESUMO

Five peptides containing (His-X2)-His or (His-X3)-His motifs have been designed and synthesized to coordinate Cu(II). Structural information was obtained by various spectroscopic techniques and was used as constraint to search for local conformational energy minima by molecular mechanics. Thermodynamic stability constants of the Cu(II) chelates was obtained by 19F-NMR. The synthesized Cu(II)-peptide chelates were tested as catalysts of some important red-ox processes occuring in biological systems, in particular oxidation of ascorbate and dismutation of superoxide ion. The catalytic efficiency of the five chelates was much lower than that of ascorbate oxidase. On the contrary, two of them showed kinetic constants for superoxide dismutation about one order of magnitude lower than that of the enzyme Cu,Zn superoxide dismutase. In both cases, the catalytic properties were dependent on the peptide sequence. The relationships between structure and activity are discussed to find the structural parameters crucial for catalytic activity that can be modulated by appropriate design and synthesis of the peptides.


Assuntos
Cobre/química , Superóxido Dismutase/química , Superóxido Dismutase/metabolismo , Sequência de Aminoácidos , Ácido Ascórbico/química , Catálise , Quelantes/química , Cobre/metabolismo , Espectroscopia de Ressonância Magnética , Modelos Moleculares , Oxirredução , Relação Estrutura-Atividade , Termodinâmica
15.
Blood ; 94(9): 3169-77, 1999 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-10556204

RESUMO

Heparin-binding epidermal growth factor-like growth factor (HB-EGF) is a widely expressed EGF superfamily member that induces mitogenic and/or chemotactic activities toward different cell types through binding to EGF receptors 1 or 4. Membrane-bound HB-EGF exerts growth activity and adhesion capabilities and possesses the unique property of being the receptor for diphtheria toxin (DT). Using molecular and functional techniques, we show that human polymorphonuclear granulocytes (PMN), which did not express HB-EGF in resting conditions, expressed it at mRNA and protein level, following incubation with granulocyte-macrophage colony-stimulating factor (GM-CSF). Other classic agonists for PMN (including lipopolysaccharide, phagocytable particles, tumor necrosis factor-alpha, or G-CSF) failed to induce HB-EGF. The effects of GM-CSF on HB-EGF mRNA levels were concentration-dependent, reached a plateau after 1 to 2 hours of stimulation, and did not require protein synthesis. After GM-CSF treatment, membrane-bound HB-EGF was detected by flow cytometry. At the same time, PMN acquired sensitivity to the apoptosis-promoting effect of DT, which, moreover, specifically suppressed the GM-CSF-induced priming of formyl-methionyl-leucyl-phenylalanine-stimulated superoxide anion release. Finally, soluble HB-EGF was detected in the PMN culture medium by a specific enzyme-linked immunosorbent assay. Thus, we provide evidence that HB-EGF is specifically inducible by GM-CSF in PMN and represents a novel peptide to be included in the repertoire of PMN-derived cytokines.


Assuntos
Toxina Diftérica/farmacologia , Fator de Crescimento Epidérmico/biossíntese , Fator Estimulador de Colônias de Granulócitos e Macrófagos/farmacologia , Neutrófilos/metabolismo , Receptores de Superfície Celular/biossíntese , Citometria de Fluxo , Fator de Crescimento Semelhante a EGF de Ligação à Heparina , Humanos , Peptídeos e Proteínas de Sinalização Intercelular , RNA Mensageiro/biossíntese
16.
Haematologica ; 84(8): 683-9, 1999 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10457402

RESUMO

BACKGROUND AND OBJECTIVE: Measles virus infection (MVI) has been reported to be characterized by an imbalanced Th(1/2)-type cytokine profile. CD30 has been proposed as a receptor preferentially associated with the Th(0/2)-type cytokine pattern. The aim of this study was therefore to define the peripheral T lymphocyte cytokine profile and to test which CD30 expression pattern it was associated with in MVI. DESIGN AND METHODS: The design of the study was a prospective evaluation with comparative analysis. The serum levels of the soluble form of CD30 (sCD30) were determined at diagnosis and at weekly intervals up to 4 weeks, using an ELISA, in 23 males (median age 19), who developed MVI while serving in the Italian army and who were admitted to the Infectious Disease Unit of the Military Hospital in Padua. In 10 of the patients at diagnosis we studied the lymphoid immunophenotype and, after non-specific ex vivo stimulation, the expression of IFNgamma, IL-2 and IL-4 by peripheral T cells using flow cytometry single cell analysis. In 3 patients such evaluations were also performed 7 weeks later. RESULTS: At diagnosis, we found (i) reduction of IFNgamma+/CD4+ T cells (p=0.048 vs controls) in the absence of substantial variation of IL-2+ and IL-4+ T cells (p=ns vs controls); (ii) expansion of CD30+/ CD4+ and CD30+/CD8+ T cell subsets (p<0.01 vs controls); (iii) high sCD30 values (median 61 U/mL; p<0.001 vs controls); (iiii) a context of lymphopenia (0. 728+/-0.292 lymph x10(9)/L). sCD30 remained elevated up to 4 weeks from MVI onset [median values 53, 49, 50, 34 U/mL after 1, 2, 3 and 4 weeks, respectively (p=ns between different time points)]. In 3 patients tested 7 weeks after diagnosis, we still observed decreased IFNgamma production by CD4+ and CD8+ T cells (p=0.05 and <0.01, respectively vs controls) and reduction of CD4+ and CD8+/IL-2+ T cells (p<0.01). INTERPRETATION AND CONCLUSIONS: MVI was characterized by featuresof inadequate Th/Tc(1) activation associated with increased circulating CD30+ T cells and elevated sCD30 levels, supporting a correlation between Th/Tc status and CD30 expression/release pattern in vivo.


Assuntos
Interferon gama/imunologia , Interleucina-2/imunologia , Interleucina-4/imunologia , Antígeno Ki-1/imunologia , Sarampo/imunologia , Subpopulações de Linfócitos T/imunologia , Adulto , Citometria de Fluxo , Humanos , Imunofenotipagem , Interferon gama/biossíntese , Interleucina-2/biossíntese , Interleucina-4/biossíntese , Antígeno Ki-1/biossíntese , Masculino
17.
Int J Clin Lab Res ; 29(2): 80-4, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10436266

RESUMO

Selenium is an essential component of glutathione peroxidase enzymes, which protect cells against peroxidation and control concentrations of intracellular proxides. Since selenium deficiency is associated with an increased incidence of arterial thrombosis, we studied the effect of selenium on in vitro interactions between platelets and endothelial cells. Platelets from normal volunteers on a diet with (PLTSe+) or without (PLTSe-) selenium supplementation and human umbilical vein endothelial cells cultured in medium alone (ECSe-) or supplemented with Se (ECSe+) were used. The effect of in vivo administration or in vitro supplementation of selenium on platelet function was investigated in an aggregometry model designed for studying the interactions between platelets and endothelial cells using ADP and arachidonic acid as agonists. We observed that: (1) selenium-dependent glutathione peroxidase enzyme activity increased in both PLTSe+ and ECSe+, being about fivefold higher in the former; (2) platelet aggregation was inhibited by Se+ cells; (3) Se+ cells released less thromboxane B(2) (PLTSe+) and more 6-keto-prostaglandin F(1alpha) (ECSe+) than Se- cells; (4) when ECSe+ were treated with acetylsalicylic acid, the inhibitory effect of selenium on platelet aggregation disappeared; (5) the concentration of nitric oxide metabolites in Se+ culture media did not differ from that in Se- media. We suggest that an antithrombotic effect on the interactions between platelets and endothelial cells can be induced by stimulating glutathione peroxidase enzymes with selenium via a mechanism that is blocked by acetylsalicylic acid and is apparently unrelated to the biosynthesis of nitric oxide metabolites.


Assuntos
Plaquetas/efeitos dos fármacos , Endotélio Vascular/efeitos dos fármacos , Agregação Plaquetária/efeitos dos fármacos , Selênio/fisiologia , Selenito de Sódio/farmacologia , 6-Cetoprostaglandina F1 alfa/metabolismo , Difosfato de Adenosina/farmacologia , Aspirina/farmacologia , Células Cultivadas , Meios de Cultivo Condicionados , Endotélio Vascular/citologia , Ativação Enzimática/efeitos dos fármacos , Glutationa Peroxidase/metabolismo , Humanos , Óxido Nítrico/metabolismo , Selenito de Sódio/administração & dosagem , Tromboxano A2/biossíntese , Tromboxano B2/metabolismo
18.
Biochim Biophys Acta ; 1427(3): 329-36, 1999 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-10350648

RESUMO

Dopaminochrome formation is catalyzed by commercially available purified peroxidases (EC 1.11.1.7) such as horseradish, lacto- and myelo-peroxidase using dopamine, hydrogen peroxide or promethazine sulfoxide as substrates. A rat brain fraction (RBF) catalyzes a similar reaction and its catalytic power increases after preincubation with hydrogen peroxide/ascorbic acid. The activity of both the purified enzymes and the RBF preparation is inhibited by carnosine and characterized by excess substrate inhibition. The enzymes recognize different substrates but show the highest affinity for dopamine. The RBF fraction is strongly buffered against oxidation by compounds such as glutathione and by bioreductive enzymes such as DT-diaphorase (EC 1.6.99.2) which can use as a substrate menadione or dopaminochrome. The rat brain dopamine peroxidizing activity appeared to be mostly bound to the synaptosomal fraction. The reaction catalyzed by the purified peroxidases was followed by electron spin resonance spectroscopy and, unlike that catalyzed by RBF, was shown to produce the signal of a transient dopamine-o-semiquinone radical.


Assuntos
Encéfalo/metabolismo , Dopamina/metabolismo , Indolquinonas , Indóis/metabolismo , Peroxidases/metabolismo , Animais , Dopamina/química , Espectroscopia de Ressonância de Spin Eletrônica , Concentração de Íons de Hidrogênio , Indóis/química , Lactoperoxidase/metabolismo , Masculino , Oxirredução , Peroxidases/química , Ratos , Ratos Wistar , Sinaptossomos/metabolismo
19.
J Clin Oncol ; 17(5): 1595-600, 1999 May.
Artigo em Inglês | MEDLINE | ID: mdl-10334549

RESUMO

PURPOSE: Implementing predictive genetic testing for a severe and common chronic disease such as breast cancer may raise unique ethical problems. Here we report on moral concerns experienced by patients in the setting of genetic counseling based on BRCA1/2 gene testing. PATIENTS AND METHODS: Patients were members of breast or breast/ovarian cancer families in a consecutive series of 100 families who received counseling at a familial cancer clinic. The patients' moral concerns were identified using the grounded theory approach in the qualitative analysis of verbal transcripts of 45 counseling sessions. Included were sessions with patients who had breast and ovarian cancer, as well as their male and female relatives, before and after the specific BRCA1/2 gene mutation was identified in the family, and before and after those who opted for mutation analysis were informed of their carrier status. RESULTS: There is an association of BRCA1/2 gene mutation carrier status and specific topics of moral concern. The moral preoccupations of patients with breast and ovarian cancer (probable carriers) related to their being instrumental in the detection of the specific mutation segregating in the family. The preoccupations of possible carriers concerned their own offspring. Individuals who tested positive (proven carriers) were concerned with issues of confidentiality. Patients who tested negative (proven noncarriers) were concerned with helping siblings and other relatives. CONCLUSION: Knowledge of the moral concerns of subjects in the study sample may help health care providers be aware of the moral concerns of their own patients. This report may also contribute to the debate on predictive testing for familial adult-onset diseases from the patient's perspective.


Assuntos
Neoplasias da Mama/genética , Neoplasias da Mama/psicologia , Predisposição Genética para Doença/psicologia , Heterozigoto , Mastectomia/psicologia , Princípios Morais , Proteína BRCA2 , Neoplasias da Mama/prevenção & controle , Feminino , Genes BRCA1 , Aconselhamento Genético , Predisposição Genética para Doença/genética , Humanos , Masculino , Mutação , Proteínas de Neoplasias , Linhagem , Cônjuges , Fatores de Transcrição
20.
J Biochem Biophys Methods ; 38(3): 191-202, 1999 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-10100950

RESUMO

The esterification of the three polysaccharides, starch, amylose and amylopectin was carried out in pyridine-DMSO by succinic anhydride. The carboxylic groups in the succinylated polysaccharides were measured by FT-IR spectroscopy. The succinic derivatives were tested as alpha-amylase (1,4-alpha-D-glucan glucano hydrolase, E.C. 3.2.1.1) substrates. A colorimetric assay of the alpha-amylase activity indicated that this enzyme is active on succinic esters of starch and amylose and that the activity shows a linear decrease with the number of succinic units introduced into the polysaccharide. Since the colorimetric test was not suitable for the detection of the alpha-amylase activity when succinylated amylopectin was the substrate, we set-up an assay based on the labeling by a paramagnetic probe of the free carboxylic groups of succinylated polysaccharides. The kinetics of the alpha-amylase reaction were monitored by ESR spectroscopy through the increase of the mobility of the paramagnetic probe. The spin label used was the commercially available 4-amino-tempo. By this method we demonstrated that alpha-amylase is active on succinylated amylopectin. The utility of the assay for monitoring alpha-amylase activity when other methods (i.e. colorimetric tests) fail, is discussed.


Assuntos
Amilopectina/química , Amilose/química , Análise Espectral/métodos , alfa-Amilases/análise , Ácidos Carboxílicos/química , Solanum tuberosum/química , Espectrofotometria Infravermelho , Anidridos Succínicos/química , Fatores de Tempo , Triticum/química
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