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1.
Proc Natl Acad Sci U S A ; 91(24): 11452-6, 1994 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-7972083

RESUMO

Modification of low density lipoprotein (LDL) by free radical oxidation renders this molecular complex cytotoxic. Oxidized lipoproteins exist in vivo in atherosclerotic lesions and in the plasma of diabetic animals, suggesting that lipoprotein-induced tissue damage may occur in certain diseases. We undertook purification and identification of the major cytotoxin in oxidized LDL. The lipid extract from oxidized LDL was subjected to multiple HPLC separations, and the fractions were assayed for cytotoxicity. Mass spectrometry and nuclear magnetic resonance identified the purified toxin as 7 beta-hydroperoxycholest-5-en-3 beta-ol (7 beta-OOH-Chol). This molecule accounted for approximately 90% of the cytotoxicity of the lipids of oxidized LDL. We also found 7 beta-OOH-Chol in human atherosclerotic lesions from endarterectomy specimens obtained immediately after excision. These results are consistent with the hypothesis that the oxidized LDL present in lesions has the capacity to induce cell and tissue injury, leading to progression of the disease and the generation of the necrotic core of the lesion.


Assuntos
Arteriosclerose/metabolismo , Colesterol/análogos & derivados , Citotoxinas , Lipoproteínas LDL/química , Células Cultivadas , Colesterol/metabolismo , Cromatografia Gasosa , Cromatografia em Camada Fina , Humanos , Técnicas In Vitro , Espectroscopia de Ressonância Magnética , Masculino , Oxirredução
2.
Clin Pharmacol Ther ; 52(6): 597-604, 1992 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-1458769

RESUMO

The effects of a 48-hour 0.5 mg/kg/hr infusion of the thromboxane synthase inhibitor pirmagrel were studied in 10 renal allograft recipients with cyclosporine nephrotoxicity. Plasma concentrations reached a mean steady-state plasma level of 1798 +/- 481 ng/ml. Biphasic, rapid elimination of pirmagrel was observed with a distribution half-life of 6.7 minutes and a terminal half-life of 73 minutes. Plasma clearance and the volume of distribution of the drug were 300 +/- 87 ml/hr/kg and 497 +/- 232 ml/kg, respectively. The pharmacodynamic effects of pirmagrel were marked by a mean 96% suppression of serum thromboxane B2 (TXB2), which coincided with a suppression of urinary excretion of TXB2, 2,3-dinor-TXB2, and 11-dehydro-TXB2 of 85% +/- 8%, 91% +/- 5%, and 89% +/- 9%, respectively. Urinary excretion of all thromboxane metabolites measured at the end of 1 week after termination of infusion was returned to the baseline. In conclusion, pirmagrel caused effective and sustained suppression of all thromboxane derived metabolites in plasma and urine during continuous infusion in kidney transplant patients receiving cyclosporine.


Assuntos
Imidazóis/farmacocinética , Transplante de Rim/fisiologia , Piridinas/farmacocinética , Tromboxano-A Sintase/antagonistas & inibidores , Adulto , Meia-Vida , Humanos , Imidazóis/farmacologia , Infusões Intravenosas , Piridinas/farmacologia , Radioimunoensaio , Tromboxano B2/metabolismo , Transplante Homólogo
3.
J Pers Assess ; 57(1): 77-86, 1991 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-1920037

RESUMO

We investigated differences between human figure drawings of adjudicated and nonadjudicated adolescents. In addition, the relationship between human figure drawings and crime category (person, property, other, none) was examined for the adjudicated adolescents. Subjects consisted of four groups of adolescents (n = 25 each): adjudicated males, adjudicated females, nonadjudicated males, and nonadjudicated females. Human figure drawings were obtained from all subjects; they were scored using a system that was developed for use with adolescents. Kruskal-Wallis one-way analyses of variance (ANOVAs) were used to assess the effects of adjudication status and gender. There were 11 significant differences between adjudicated and nonadjudicated adolescents and 11 differences among the four groups. Results of Kruskal-Wallis ANOVAs also showed two significant differences among crime categories.


Assuntos
Delinquência Juvenil/psicologia , Determinação da Personalidade , Técnicas Projetivas , Adolescente , Psicologia Criminal , Feminino , Identidade de Gênero , Humanos , Delinquência Juvenil/reabilitação , Masculino , Desenvolvimento da Personalidade , Técnicas Projetivas/estatística & dados numéricos , Psicometria
4.
Clin Pharmacol Ther ; 49(4): 433-41, 1991 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-2015733

RESUMO

The pharmacokinetics and pharmacodynamics of biochemical effect of a selective thromboxane synthase inhibitor, CGS 12970, were studied in healthy male volunteers after a dosing scheme of either 200 mg once daily or 100 mg twice a day for 6 days. The peak plasma concentration appeared 1 to 2 hours after administration, followed by a biexponential decline with half life values of about 1 and 7 hours, respectively. The mean oral clearance was 16 L/hr. Biochemically, the capacity of the platelets to form thromboxane A2 ex vivo (serum) was inhibited greater than 90% at both doses. In contrast to the short plasma half-life, the suppression of ex vivo serum thromboxane production was maintained greater than 70% to 80% at 48 hours after dosing. Inhibition of the thromboxane production in vivo (urine) was also substantial, but incomplete at both doses (200 mg daily; thromboxane B2, 75%; 2,3-dinor-thromboxane B2, 83%; 11-dehydrothromboxane B2, 90%). The urinary excretion, however, returned to the predose level at the end of a 1-week follow-up period after the last dosing. In conclusion, CGS 12970 is an orally active, reversible inhibitor of thromboxane synthase with a prolonged duration of action in humans.


Assuntos
Piridinas/farmacocinética , Tromboxano A2/biossíntese , Tromboxano-A Sintase/antagonistas & inibidores , Administração Oral , Adulto , Proteínas Sanguíneas/metabolismo , Meia-Vida , Humanos , Masculino , Taxa de Depuração Metabólica , Pessoa de Meia-Idade , Piridinas/sangue , Piridinas/farmacologia , Tromboxano A2/urina
5.
J Steroid Biochem Mol Biol ; 38(3): 351-7, 1991 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-2009227

RESUMO

11 beta-Hydroxy dehydrogenation of cortisol to cortisone is specifically impaired in the syndrome of apparent mineralocorticoid excess. This defect bears on the pathogenesis of the disorder by unmasking the potential mineralocorticoid agonism of unmetabolized cortisol at or near mineralocorticoid target tissues. A specific index of this defect is provided by measurement of the formation of tritiated water following the administration of [3H]11 alpha-cortisol. We have explored the use of a non-radioactive tracer to follow this unidirectional dehydrogenation reaction but because of the relatively lower sensitivity of measurement of 2H2O compared to 3H2O in body fluids, use of the corresponding [2H]11 alpha-cortisol was not feasible. We have devised instead a method incorporating additional deuterium atoms into cortisol to measure unidirectional 11 beta-hydroxy dehydrogenation not by the formation of labeled water but by the determination of the dehydrogenated cortisol product from its residual deuterium content. Cortisol-d4 metabolized to cortisone-d3 is conveniently measured by the techniques of organic mass spectrometry. The synthesis of cortisol-9 alpha, 11 alpha, 12 alpha 12 beta-d4 and the validation of its isotopic distribution by mass spectrometry and nuclear magnetic resonance is described.


Assuntos
Hidrocortisona/síntese química , Cortisona/química , Deutério , Humanos , Hidrocortisona/química , Hidrogenação , Espectroscopia de Ressonância Magnética , Espectrometria de Massas
6.
Mech Ageing Dev ; 44(1): 69-89, 1988 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-3205065

RESUMO

The role of free-radical-induced lipid oxidation in the development of human lens opacity was studied. Physico-chemical parameters of the lens fiber membranes at different stages of cataract have been investigated. The deterioration of lens fiber plasma membranes structure preceding formation of large aggregates in lenticular matter, leading to lens opacity, was observed by electron microscopy. Initial stages of cataract were characterized by the accumulation of primary (diene conjugates, cetodienes) lipid peroxidation (LPO) products, while in the later stages there was a prevalence of end LPO fluorescent products. Reliable increase in oxiproducts of fatty acyl content of lenticular lipids was shown by direct gas chromatography technique obtaining fatty acid fluorine-substituted derivatives. The lens opacity degree is found to correlate with the level of the end LPO fluorescent product accumulation in its tissue, accompanied by SH group oxidation of crystallins due to decrease of reduced glutathione concentration in the lens. The injection of LPO products into the vitreous has been shown to induce cataract. It was concluded that peroxide damage of the lens fiber membranes may be the initiatory cause of cataract development.


Assuntos
Catarata/etiologia , Peróxidos Lipídicos/fisiologia , Catarata/patologia , Membrana Celular/ultraestrutura , Humanos , Cristalino/fisiopatologia , Cristalino/ultraestrutura , Microscopia Eletrônica
7.
Vopr Med Khim ; 34(1): 83-6, 1988.
Artigo em Russo | MEDLINE | ID: mdl-3259348

RESUMO

Short-term administration of hydrocortisone into rats (within 7 days) stimulated 1.25(OH)2D3 synthesis in kidney and led to accumulation of the metabolite in blood serum, small intestinal mucose and bones. After long-term administration of hydrocortisone within 28 days synthesis of 1.25(OH2D3) was decreased in kidney while the content of 24.25(OH)2D3 was was simultaneously increased. Concentration of labelled 1.25 (OH)2D3 and 24.25(OH)2D3 was distinctly decreased in small intestinal mucose and femur bones.


Assuntos
Hiperfunção Adrenocortical/metabolismo , Hidrocortisona/farmacologia , Vitamina D/metabolismo , 24,25-Di-Hidroxivitamina D 3 , Hiperfunção Adrenocortical/induzido quimicamente , Animais , Calcitriol/biossíntese , Cálcio/metabolismo , Di-Hidroxicolecalciferóis/biossíntese , Masculino , Ratos , Ratos Endogâmicos , Distribuição Tecidual
8.
Biokhimiia ; 51(10): 1702-7, 1986 Oct.
Artigo em Russo | MEDLINE | ID: mdl-3778973

RESUMO

Gas chromatography analysis with the use of an electron captured detector including preparation of the halogen-substituted derivatives of fatty acids is a useful tool for the detection of lipid peroxidation products both in vitro and in vivo. This technique was applied to determine the content of fatty acid oxy-derivatives in lipid samples of transparent and completely opaque human lenses. At the stage of mature cataract a significantly increased level of oxyproducts was observed in the lens lipid fraction. It was concluded that accumulation of polar oxygroups in the lipid bilayer of plasma membranes of lens fibres is a plausible cause of their damage in cataracts.


Assuntos
Catarata/metabolismo , Ácidos Graxos Insaturados/metabolismo , Cristalino/metabolismo , Peróxidos Lipídicos/metabolismo , Cromatografia Gasosa , Humanos , Oxirredução
9.
Biofizika ; 31(4): 681-6, 1986.
Artigo em Russo | MEDLINE | ID: mdl-3756234

RESUMO

Microcolumn liquid and column chromatography technique is conjunction with UV-spectrophotometry and spectrofluorescent analysis were used to study lipid peroxidation products accumulated in human lenses during cataract formation by means of chromatographic separation in regard to the molecular weight and polarity properties. Cataract is characterized by the appearance of certain substances changing UV-absorption lipid spectra in the region of 230 and 274 nm and having special fluorescence (excitation--320-370 nm), (emission--405-460 nm). The same changes were observed by ultrasoundinduced lipid peroxidation of model lipid samples. The accumulated lipid peroxidation products are concentrated in the same chromatographic fractions that are responsible for the change of UV-absorption and fluorescent spectra of lipids of cataractous lenses. It is the evidence of free radical lipid peroxidation products accumulation in human lenses at cataract formation. Along with the formation of diene and triene conjugates in the lens lipids, cataract is characterized by the formation of cetodienes and of low molecular weight lipid fluorescent products of fatty acids oxidation with low polarity due to the appearance of tetraene derivatives of polyunsaturated fatty acids. The particular features of mature cataract are an increased intensity of long-wave lipid fluorescence in the blue-green region (430-460 nm) of the spectrum, formation of high molecular weight fluorescent lipid peroxidation products with high polarity, and smooth decrease in absorbance in the region of 220-330 nm. During cataract formation products of deep lipid peroxidation resulting from radical phospholipids and fatty acids polymerisation are accumulated. It is supposed that lipid peroxidation is an initial phase of membrane desintegration and formation of HMW-proteins in cataract.


Assuntos
Catarata/metabolismo , Cristalino/análise , Lipídeos/análise , Catarata/etiologia , Cromatografia Líquida , Humanos , Peróxidos Lipídicos/análise , Peso Molecular , Espectrometria de Fluorescência
10.
Biull Eksp Biol Med ; 98(7): 44-6, 1984 Jul.
Artigo em Russo | MEDLINE | ID: mdl-6466829

RESUMO

A study was made of rabbit small intestine secretion induced by cholera and salmonellosis toxins. Application of electron impact mass-spectrometry and chemical ionization permitted identification of 9 and structure assignment for 14 out of 27 secretion components. The assay demonstrated the major part of the components to be the monosaccharides, glucose and galactose. Fatty acids, cholesterol and hydroxyacids were found to be present in negligible amounts. It was discovered that the action of the toxins primarily affected the metabolism of unsaturated fatty acids.


Assuntos
Toxinas Bacterianas/farmacologia , Secreções Intestinais/análise , Animais , Toxina da Cólera/farmacologia , Cromatografia Gasosa-Espectrometria de Massas , Secreções Intestinais/efeitos dos fármacos , Intestino Delgado/efeitos dos fármacos , Coelhos , Salmonella
11.
Biokhimiia ; 49(4): 590-8, 1984 Apr.
Artigo em Russo | MEDLINE | ID: mdl-6329324

RESUMO

The influence of short-(7 days) and long-term (28 days) hypokinesia on 25-hydroxyvitamin D3 metabolism was investigated in rats fed on a normal calcium (0.6%), normal phosphorus (0.6%), vitamin D-supplemented diet. The animals were given a single intraperitoneal dose of tritiated [26,27-3H]25(OH)D3 (200 pmol) eighteen hours before sacrifice. [3H]Labelled vitamin D3 metabolites were separated by high performance liquid chromatographic procedure, and their radioactivity levels in serum, kidney, intestinal mucosa and femoral bone were measured. Long-term hypokinesia resulted in decreased levels of [3H]1.25(OH)2D3 and increased levels of [3H]24.25(OH)2D3 in serum and kidney (3.15 +/- 0.62 vs. 4.33 +/- 0.41% and 5.34 +/- 0.69 vs. 3.76 +/- 0.29% for [3H]1.25(OH)2D3 and [3H]24.25(OH)2D3 in serum; 7.52 +/- 0.69 vs. 11.6 +/- 0.79% and 9.33 +/- 0.55 vs. 5.94 +/- 0.24% for those in kidney). The levels of [3H]1.25(OH)2D3 as well as of [3H] 24.25(OH)2D3 were decreased in intestinal mucosa and bone (21.5 +/- 1.46 vs. 30.1 +/- 3.04% and 7.30 +/- 0.58 vs. 9.18 +/- 0.78% for [3H]1.25(OH)2D3 and [3H]24.25(OH)2D3 in intestinal mucosa; 6.39 +/- 06.5 vs. 11.5 +/- 1.64% and 7.78 +/- 0.71 vs. 13.9 +/- 1.28% for those in bone). The data obtained suggest a suppressed synthesis of 1.25(OH)2D3 and enhanced production of 24.25(OH)2D3 in kidney as well as a diminished binding of 24.25(OH)2D3 in intestinal mucosa and bone in hypothetic rats. Possible causes of variations in biosynthesis of vitamin D3 active metabolites, and role of these variations in the disorders of calcium metabolism and bone state during hypokinesia are discussed.


Assuntos
Calcifediol/metabolismo , Cálcio/metabolismo , Colecalciferol/metabolismo , Imobilização , Animais , Transporte Biológico , Osso e Ossos/metabolismo , Calcifediol/biossíntese , Calcifediol/sangue , Calcitriol/biossíntese , Calcitriol/sangue , Calcitriol/metabolismo , Cálcio/sangue , Colecalciferol/biossíntese , Colecalciferol/sangue , Cromatografia Líquida de Alta Pressão , Mucosa Intestinal/metabolismo , Canais Iônicos/metabolismo , Rim/metabolismo , Masculino , Fósforo/sangue , Fósforo/metabolismo , Ratos , Ratos Endogâmicos
12.
Vopr Med Khim ; 30(1): 96-103, 1984.
Artigo em Russo | MEDLINE | ID: mdl-6608823

RESUMO

At the third day after femur fracture concentration of 3H-25-hydroxycholecalciferol [3H-25(OH)D3], intraperitoneally administered into rats within 18 hrs before killing, was increased in kidney and small intestine mucosa by 25% and 60%, respectively, as well as incorporation of the label into 1,25(OH)2D3 in blood serum and small intestine mucosa was increased by 50% and 70%, respectively, as compared with intact controls. Binding of 3H-25(OH)D3 was increased 2-3-fold in diaphyses and epiphyses of impaired bones within 3 and 10 days after the fracture. Similar, but less distinct accumulation of 3H-25(OH)D3 was observed in unimpaired femur of rats with the bone fracture. Incorporation of the label into 1,25(OH)2D3 and 24,25(OH)2D3 was increased 1.5-2-fold in epiphyses of the impaired bone as well as in epiphyses and diaphyses of intact femur of rats with the bone fracture at all the periods studied (3, 10, 28 days after the fracture).


Assuntos
Calcifediol/metabolismo , Fraturas do Fêmur/metabolismo , Fêmur/metabolismo , 24,25-Di-Hidroxivitamina D 3 , Animais , Calcifediol/sangue , Calcitriol/metabolismo , Cromatografia Líquida , Di-Hidroxicolecalciferóis/metabolismo , Epífises/metabolismo , Fraturas do Fêmur/sangue , Mucosa Intestinal/metabolismo , Rim/metabolismo , Masculino , Ratos , Ratos Endogâmicos
13.
Ukr Biokhim Zh (1978) ; 54(4): 395-9, 1982.
Artigo em Russo | MEDLINE | ID: mdl-7135496

RESUMO

The paper deals with the phospholipid composition in the mucosa tissue of different areas of gastrointestinal tract and in membranes of the villous margin of small intestine enterocytes under conditions of experimental salmonellosis infection. A decreased relative content of cardiolipin is observed in all periods of the infection process in the stomach mucosal tissue and in the period of the disease height and convalescence--in the sigmoid colon. Phosphatidyl choline appears in the tissue of duodenum and jejunum during the height of the infection process. An increase in a relative content of lysophosphatidyl choline and phosphatidyl serine and a decrease in that of phosphatidyl ethanolamine are revealed in membranes of enterocyte villous margin when modelling the diarrhea process by the intraperitoneal administration of the lipopolysaccharide complex of salmonellas. The found changes in the composition of phospholipids in the mucous membrane tissue and membranes of the enterocytes villous margin are supposed to reflect alterations in the functional state of the intestine barrier and play a definite role in development of the diarrhea syndrome.


Assuntos
Mucosa Intestinal/metabolismo , Lipídeos de Membrana/metabolismo , Fosfolipídeos/metabolismo , Infecções por Salmonella/metabolismo , Animais , Modelos Animais de Doenças , Duodeno/metabolismo , Jejuno/metabolismo , Microvilosidades/metabolismo , Fosfatidilcolinas/metabolismo , Coelhos
14.
Biull Eksp Biol Med ; 92(12): 683-6, 1981 Dec.
Artigo em Russo | MEDLINE | ID: mdl-7326415

RESUMO

Gas liquid chromatography was made use of to examine the time course of elimination of low-molecular weight organic components with the diarrhea fluid under the effect of cholerae and salmonellosis toxins. The diarrhea fluid was shown to contain a great number of low-molecular weight metabolites some of which occur in noticeable concentrations. As a result of the action of the bacterial toxins. there appear metabolic disturbances that might be distributed into 4 types with regard to the time course of their development. The method under consideration enables the detection of disorders that occur within the latent period.


Assuntos
Cólera/metabolismo , Diarreia/metabolismo , Enterite/metabolismo , Secreções Intestinais/análise , Salmonelose Animal/metabolismo , Animais , Chinchila , Cromatografia Gasosa , Diarreia/etiologia , Modelos Animais de Doenças , Coelhos
15.
Farmakol Toksikol ; 38(4): 491-4, 1975.
Artigo em Russo | MEDLINE | ID: mdl-1213145

RESUMO

A study on the passage of phosphemide with urine and distribution of the drug over the organs and tissues of intact (without fumour) rats and those with sarcoma-45 showed the bulk of unchanged drug to be excreted together with the urine during the first 3-4 hours following its intravenous and intraperitoneal administration. In rats with sarcoma-45 phosphamide is passed with urine in a somewhat greater amount than in the intact animals. With intravenous application the rate of the drug elimination in intact rats and in the ones with carcoma-45 is virtually the same, being somewhat lower with intraperitoneal injection of phosphemide.


Assuntos
Antineoplásicos/metabolismo , Aziridinas/metabolismo , Azirinas/metabolismo , Compostos Organofosforados/metabolismo , Animais , Antineoplásicos/administração & dosagem , Aziridinas/administração & dosagem , Compostos Organofosforados/administração & dosagem , Ratos , Sarcoma Experimental/metabolismo , Fatores de Tempo
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