RESUMO
Two strains of Nocardia spp. were isolated from bovine milk of two individual bulk tank. Molecular identification classified the strains as Nocardia farcinica and Nocardia cyriacigeorgica. The thermorresistance to boiling of the isolates was carried out and was observed bacterial growth after boiling. Our findings indicate the potential risk of pathogen transmission to humans through contaminated milk with Nocardia spp.
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Xenograft outcomes are dictated by xenoantigen expression, for example, Gal alpha1, 3Gal (Gal), but might also depend on differing vascular responses. We investigated whether differential vascular gene expression in kidney and cardiac xenografts correlate with development of thrombotic microangiopathy (TM) and consumptive coagulation (CC). Immunosuppressed baboons underwent miniswine or hDAF pig kidney (n = 6) or heart (n = 7), or Gal-transferase gene-knockout (GalT-KO) (thymo)kidney transplantation (n = 14). Porcine cDNA miniarrays determined donor proinflammatory, apoptosis-related and vascular coagulant/fibrinolytic gene expression at defined time points; validated by mRNA, protein levels and immunopathology. hDAF-transgenic and GalT-KO xenografts, (particularly thymokidneys) exhibited prolonged survival. CC was seen with Gal-expressing porcine kidneys (3 of 6), only 1 of 7 baboons postcardiac xenotransplantation and was infrequent following GalT-KO grafts (1 of 14). Protective-type genes (heme oxygenase-I, superoxide dismutases and CD39) together with von Willebrand factor and P-selectin were upregulated in all renal grafts. Transcriptional responses in Gal-expressing xenografts were comparable to those seen in the infrequent GalT-KO rejection. In cardiac xenografts, fibrin deposition was associated with increased plasminogen activator inhibitor-1 expression establishing that gene expression profiles in renal and cardiac xenografts differ in a quantitative manner. These findings suggest that therapeutic targets may differ for renal and cardiac xenotransplants.
Assuntos
Rejeição de Enxerto/imunologia , Transplante de Coração/imunologia , Transplante de Rim/imunologia , Transplante Heterólogo/imunologia , Sistema ABO de Grupos Sanguíneos/imunologia , Doença Aguda , Animais , DNA Complementar/genética , Rejeição de Enxerto/mortalidade , Rejeição de Enxerto/patologia , Sobrevivência de Enxerto/imunologia , Transplante de Coração/mortalidade , Transplante de Rim/patologia , Análise de Sequência com Séries de Oligonucleotídeos , Papio , Proteínas/genética , Suínos/genética , Timo/transplante , Condicionamento Pré-Transplante/métodosRESUMO
Polyunsaturated fatty acids (PUFAs) are essential membrane components in higher eukaryotes and are the precursors of many lipid-derived signaling molecules. Here, pathways for PUFA synthesis are described that do not require desaturation and elongation of saturated fatty acids. These pathways are catalyzed by polyketide synthases (PKSs) that are distinct from previously recognized PKSs in both structure and mechanism. Generation of cis double bonds probably involves position-specific isomerases; such enzymes might be useful in the production of new families of antibiotics. It is likely that PUFA synthesis in cold marine ecosystems is accomplished in part by these PKS enzymes.
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Células Eucarióticas/metabolismo , Ácidos Graxos Insaturados/biossíntese , Gammaproteobacteria/metabolismo , Complexos Multienzimáticos/metabolismo , Anaerobiose , Ácidos Araquidônicos/biossíntese , Escherichia coli/enzimologia , Escherichia coli/metabolismo , Ácido Graxo Sintases/metabolismo , Genoma Bacteriano , Fases de Leitura Aberta , Shewanella/metabolismoRESUMO
INTRODUCTION: Torsion of an undescended testis (UDT) associated with cerebral palsy (CP) and neuromuscular disease (NMD) is an uncommon condition that is not well recognized by primary care physicians or healthcare providers. OBJECTIVE: The objective of this study was to highlight the clinical importance of torsion of a UDT in children with CP and NMD. MATERIALS AND METHODS: Eleven children with testicular torsion of a UDT operated on at the study institute between 1991 and 2015 were identified. The records of seven children (63.6%) associated with CP or NMD were retrospectively reviewed. Clinical findings of testicular torsion were assessed along with the treatment outcome and testicular salvageability. RESULTS: All seven children were not identified with a UDT by public health checkup for infant and young children. No children with CP or NMD had torsion of a descended testis during the present study period. Median age at surgery was 15 years (range, 1-20 years). The testis location was at the external inguinal ring in five patients, in the inguinal canal in one, and in the superficial inguinal pouch in one. Of the contralateral testes, four were a UDT, one was a retractile testis, and two were descended testes. Orchiectomy was performed in six patients (85.7%). In the remaining patients, the testis was preserved but became atrophic. DISCUSSION: This study demonstrated that children with CP or NMD may be affected with torsion of a UDT with peak at around puberty with the poor salvage rate, even if the testes appear descended in infancy and young children. Shortcomings of this study were the retrospective design and a small series of children undergoing surgery for torsion of a UDT. CONCLUSION: Pediatric urologists need to educate primary care physicians and healthcare providers in the recognition of acquired UDTs and possibly associated testicular torsion in children with CP and NMD. Genital examination should be continued regularly until adolescence in these children to detect acquired UDT. These children should be referred to pediatric urologists to promote surgery as soon as the diagnosis of acquired UDT is carried out. It is believed that it is perhaps the best approach to prevent loss of the testis in children with CP and NMD.
Assuntos
Paralisia Cerebral/complicações , Criptorquidismo/etiologia , Doenças Neuromusculares/complicações , Torção do Cordão Espermático/etiologia , Adolescente , Criança , Pré-Escolar , Humanos , Lactente , Masculino , Estudos Retrospectivos , Adulto JovemRESUMO
The congenital long QT syndrome (LQTS) is an inherited disorder characterized by a delay in cardiac cellular repolarization leading to cardiac arrhythmias and sudden death often in young people. One form of the disease (LQT3) involves mutations in the voltage-gated cardiac sodium channel. The potential for targeted suppression of the LQT defect was explored by heterologous expression of mutant channels in cultured human cells. Kinetic and steady state analysis revealed an enhanced apparent affinity for the predominantly charged, primary amine compound, mexiletine. The affinity of the mutant channels in the inactivated state was similar to the wild type (WT) channels (IC50 approximately 15-20 microM), but the late-opening channels were inhibited at significantly lower concentrations (IC50 = 2-3 microM) causing a preferential suppression of the late openings. The targeting of the defective behavior of the mutant channels has important implications for therapeutic intervention in this disease. The results provide insights for the selective suppression of the mutant phenotype by very low concentrations of drug and indicate that mexiletine equally suppresses the defect in all three known LQT3 mutants.
Assuntos
Antiarrítmicos/farmacologia , Síndrome do QT Longo/metabolismo , Mexiletina/farmacologia , Bloqueadores dos Canais de Sódio , Relação Dose-Resposta a Droga , Humanos , Síndrome do QT Longo/tratamento farmacológico , Mutagênese Sítio-Dirigida , Canais de Sódio/genética , Canais de Sódio/fisiologiaRESUMO
41 students took either docosahexaenoic acid (DHA)-rich oil capsules containing 1.5-1.8 grams DHA/day (17 females and 5 males) or control oil capsules containing 97% soybean oil plus 3% fish oil (12 females and 7 males) for 3 mo in a double-blind fashion. They took a psychological test (P-F Study) and Stroop and dementia-detecting tests at the start and end of the study. The present study started at the end of summer vacation and ended in the middle of mental stress such as final exams. In the control group extraggression (aggression against others) in P-F Study was significantly increased at the end of the study as compared with that measured at the start (delta = +8.9%, P = 0.0022), whereas it was not significantly changed in the DHA group (delta = -1.0%). The 95% CI of differences between the DHA and control groups were -16.8 to -3.0%. DHA supplementation did not affect the Stroop and dementia-detecting tests. Thus, DHA intake prevented extraggression from increasing at times of mental stress. This finding might help understand how fish oils prevent disease like coronary heart disease.
Assuntos
Agressão/fisiologia , Ácidos Docosa-Hexaenoicos/farmacologia , Adulto , Demência/fisiopatologia , Gorduras na Dieta/metabolismo , Método Duplo-Cego , Ácidos Graxos não Esterificados/metabolismo , Feminino , Humanos , MasculinoRESUMO
Leukotriene (LT) B4 is a major chemical activator of PMN. Inhibitory effects of oral administration of docosahexaenoic acid (DHA) on LTB4 synthesis by PMN are known. We intravenously infused tridocosahexaenoyl-glycerol (DHA-TG) emulsion into rabbits in three different doses, namely 0.8, 0.4, or 0.2 g DHA/kg, and investigated the changes in LTB4/5 production by ionophore-activated PMN. The averaged LTB4 production by PMN was significantly reduced to 57 and 59% of baseline at 6 h after the infusion of 0.8 and 0.4 g DHA/kg, respectively (P < 0.05), but not after the infusion of 0.2 g DHA/kg or 0.8 g soybean oil/kg. The combined concentrations of both DHA and eicosapentaenoic acid in the PMN phospholipid fraction were significantly increased at 6 h after the infusion of 0.8 or 0.4 g DHA/kg but not after the infusion of 0.2 g DHA/kg or 0.8 g soybean oil/kg. Oral administration of 0.8 g DHA/kg did not increase DHA or eicosapentaenoic acid in the PMN phospholipid fraction and did not decrease LTB4 production by PMN at 6 h after administration. We suggest that the infusion of 0.4-0.8 g DHA/kg might be beneficial to patients who suffer from diseases that are related to the acute elevation of LTB4 production.
Assuntos
Ácidos Docosa-Hexaenoicos/metabolismo , Ácido Eicosapentaenoico/análogos & derivados , Ácidos Graxos/sangue , Glicerol/metabolismo , Leucotrieno B4/metabolismo , Neutrófilos/metabolismo , Animais , Ácidos Docosa-Hexaenoicos/administração & dosagem , Ácido Eicosapentaenoico/metabolismo , Emulsões , Glicerol/administração & dosagem , Infusões Intravenosas , Lipídeos/sangue , Masculino , Coelhos , Óleo de Soja/administração & dosagemRESUMO
BACKGROUND AND PURPOSE: Stonefish (Synanceia genus) are commonly found in shallow waters of the Pacific and Indian Oceans. The venom of stonefish is stored in the dorsal fine spines and contains a proteinaceous toxin, verrucotoxin (VTX). The stings produced by the spines induce intense pain, respiratory weakness, damage to the cardiovascular system, convulsions and paralysis, sometimes leading to death. Although there are many studies on VTX, the mechanism(s) underlying the VTX-mediated cardiotoxicity is not yet fully understood. The aim of this study was to investigate the modulation of ion channels in cardiac tissue by VTX. EXPERIMENTAL APPROACH: The effects of VTX on changes in the voltage or current in guinea-pig ventricular myocytes were investigated using a patch clamp method. KEY RESULTS: VTX (10 microg ml(-1)) prolonged the action potential duration by 2.5-fold. VTX increased L-type Ca(2+) currents (I (Ca(L))) in a concentration-dependent manner with a EC(50) value of 7 microg ml(-1) and a maximum increase of 3.1-fold. The non-selective beta-adrenoceptor antagonist, propranolol (1 microM) and the selective beta(1)-adrenoceptor antagonist, CGP20712A (10 microM) each abolished the effect of VTX (100 microg ml(-1)) on I (Ca(L)). Furthermore, the protein kinase A (PKA) antagonists H-89 (10 microM) and Rp-8-Br-cAMPS (30 microM) inhibited the effect of VTX on I (Ca(L)). CONCLUSIONS AND IMPLICATIONS: VTX modulates Ca(2+) channel activity through the beta-adrenoceptor-cAMP-PKA pathway.
Assuntos
Canais de Cálcio Tipo L/efeitos dos fármacos , Proteínas Quinases Dependentes de AMP Cíclico/efeitos dos fármacos , Venenos de Peixe/farmacologia , Glicoproteínas/farmacologia , Miócitos Cardíacos/efeitos dos fármacos , Receptores Adrenérgicos beta/efeitos dos fármacos , Animais , Canais de Cálcio Tipo L/metabolismo , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Relação Dose-Resposta a Droga , Eletrofisiologia , Venenos de Peixe/administração & dosagem , Glicoproteínas/administração & dosagem , Cobaias , Potenciais da Membrana/efeitos dos fármacos , Miócitos Cardíacos/metabolismo , Receptores Adrenérgicos beta/metabolismoRESUMO
The effect of intragastric gavage administration of docosahexaenoic acid (DHA) on the formation of 1,2-dimethylhydrazine (DMH)-induced aberrant crypt foci in rat colon was investigated. Male F344 rats were treated three times s.c. with 20 mg/kg of DMH and were given either 0.7 ml of DHA or water intragastrically 5 times a week for 4, 8, or 12 weeks from the day before the first carcinogen treatment. The numbers of DMH-induced aberrant crypt foci per colon after 4, 8, and 12 weeks of DHA treatment were approximately 40% of those in the respective control groups, and the differences were statistically significant. The numbers of foci reached plateau levels at 8 weeks in both the DHA-treated and control groups. The mean number of aberrant crypts per focus was also significantly smaller in the group given DHA than that in the control group at each time. These results suggest that DHA suppresses the formation and growth of aberrant crypt foci and has a preventive effect on colon carcinogenesis.
Assuntos
Colo/efeitos dos fármacos , Neoplasias do Colo/prevenção & controle , Ácidos Docosa-Hexaenoicos/farmacologia , 1,2-Dimetilidrazina , Animais , Peso Corporal/efeitos dos fármacos , Carcinógenos , Colo/patologia , Neoplasias do Colo/sangue , Neoplasias do Colo/induzido quimicamente , Neoplasias do Colo/patologia , Dimetilidrazinas , Masculino , Ratos , Ratos Endogâmicos F344RESUMO
In our previous report (Shikano, M., Masuzawa, Y. and Yazawa, K. (1993) J. Immunol. 150, 3525-3533), we described that the enrichment of docosahexaenoic acid (DHA, 22:6(n - 3)) reduces both arachidonic acid (AA, 20:4(n - 6)) release and platelet-activating factor (PAF) synthesis in human eosinophilic leukemia cells, Eol-1. Since no DHA release was observed in response to Ca-ionophore stimulation, we presumed that the phospholipase A2 (PLA2) responsible for AA release and PAF synthesis can not hydrolyze the DHA moiety of phospholipids. In the present paper, we examined whether DHA-containing diacyl- and alkenylacylglycerophosphoethanolamine (DHA-diacylGPE and DHA-alkenylacyGPE) are susceptible to the action of AA-preferential 85 kDa cytosolic phospholipase A2 (cPLA2) from rabbit platelets in comparison with AA and eicosapentaenoic acid (EPA, 20:5(n - 3)) derivatives. When diacylGPE was used as a substrate, DHA release was almost negligible under the assay condition that allowed AA and EPA to be liberated at the rates of 4.3 mumol/min per mg protein and 2.5 mumol/min per mg protein, respectively. On the other hand, 14 kDa type II PLA2 hydrolyzed DHA-diacylGPE as well as AA-diacylGPE and EPA-diacylGPE. When DHA-diacylGPE and AA-diacylGPE were mixed at equimolar concentrations, DHA release by cPLA2 was not observed and AA release was reduced to 32% in the case without DHA-diacylGPE. This indicated that DHA-diacylGPE is a poor substrate but possesses the inhibitory activity for cPLA2. cPLA2 does not clearly discriminate between AA-alkenylacylGPE and AA-diacylGPE. As in the case using diacylGPE as a substrate, DHA-alkenylacylGPE was completely discriminated from AA-alkenylacylGPE by cPLA2. The roles of DHA and cPLA2 in the synthesis of lipid mediators will be discussed in relation to the new aspects of the substrate specificity of cPLA2 provided here.
Assuntos
Ácido Araquidônico/metabolismo , Ácidos Docosa-Hexaenoicos/metabolismo , Fosfatidiletanolaminas/metabolismo , Fosfolipases A/metabolismo , Plasmalogênios/metabolismo , Animais , Ácido Eicosapentaenoico/metabolismo , Hidrólise , Fosfolipases A/antagonistas & inibidores , Fosfolipases A2 , Coelhos , Especificidade por Substrato , Fatores de TempoRESUMO
Lymphatic transport of eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids given as trieicosapentaenoyl glycerol (TriEPA) and tridocosahexaenoyl glycerol (TriDHA) was compared with that of ethyl ester and free acid in rats cannulated with thoracic duct. Trioleoylglycerol (TO) served as a control. EPA and DHA, compared with oleic acid, were slowly transported in lymph irrespective of fat types administered. Total 24-h recovery of DHA in all fat types and ethyl EPA was significantly lower compared to that of oleic acid. Lymphatic recovery of EPA and DHA in rats given TriEPA and TriDHA was significantly higher at the first 3 h after the administration compared to those given as free acid or ethyl ester. The recovery in rats given free acid at a later stage (9-24 h) was higher than that of the other fat types. As a result, the 24-h recovery was comparable between triacylglycerol (TAG) and free acid, while it was significantly lower in ethyl ester. Although TriEPA and TriDHA were slowly hydrolyzed by pancreatic lipase in vitro compared with TO and TAGs rich in EPA or DHA at the second position, the hydrolysis rate at 60 min incubation was comparable among the TAGs examined. The hydrolysis rate of ethyl esters was extremely low even in 6 h incubation with lipase. These observations show that presence of EPA and DHA at the 1- and 3-positions of TAGs does not result in their lower recovery in lymph. Processes after lipolysis may be responsible for their low recovery in lymph. In a separate study, slower lymphatic recovery of DHA given as free acid than TriDHA was improved by the simultaneous administration of TO, but not by free oleic acid. The observations suggest that the slow recovery of free acid is caused by delayed TAG synthesis in mucosal cells and/or low micellar solubility of fatty acids in the intestinal lumen due to a limited supply of 2-monoacylglycerol (MAG). A large portion of EPA and DHA were recovered in lymph chylomicrons and very low density lipoproteins (VLDL, > 95%) and incorporated into TAG (84-92%) fraction in all fat types examined. Lymphatic recovery rate of simultaneously administered cholesterol was influenced by the fat types given.
Assuntos
Ácidos Docosa-Hexaenoicos/metabolismo , Ácido Eicosapentaenoico/metabolismo , Linfa/química , Linfa/metabolismo , Animais , Peso Corporal , Quilomícrons/metabolismo , Ésteres/metabolismo , Absorção Intestinal/fisiologia , Lipase/metabolismo , Sistema Linfático/metabolismo , Ácido Oleico , Ácidos Oleicos/metabolismo , Ácidos Oleicos/farmacologia , Fosfolipídeos/metabolismo , Ratos , Triglicerídeos/metabolismo , Trioleína/metabolismo , Trioleína/farmacologiaRESUMO
A fundamental obstacle in gene therapy for cancer is the specific delivery of an anticancer gene product to a solid tumor, and yet no systemic delivery system that specifically targets solid tumors currently exists. A strain of domestic bacteria, Bifidobacterium longum, which is nonpathogenic and anaerobic, selectively localized and proliferated in several types of mouse solid tumors after systemic application. In this report, we further describe a novel approach to cancer gene therapy in which genetically engineered Bifidobacterium is used as a tumor-specific vector. Similarly to wild-type B. longum, genetically engineered B. longum could be detected in tumor tissue only and was not found in a large survey of normal mouse tissues after intravenous injection. This finding strongly suggests that obligate anaerobic bacteria such as Bifidobacterium can be used as highly specific gene delivery vectors for cancer gene therapy.
Assuntos
Bifidobacterium/crescimento & desenvolvimento , Bifidobacterium/genética , Carcinoma Pulmonar de Lewis/genética , Carcinoma Pulmonar de Lewis/terapia , Terapia Genética/métodos , Melanoma Experimental/genética , Melanoma Experimental/terapia , Animais , Bifidobacterium/metabolismo , Carcinoma Pulmonar de Lewis/microbiologia , Carcinoma Pulmonar de Lewis/patologia , Hipóxia Celular/genética , Resistência Microbiana a Medicamentos , Engenharia Genética , Masculino , Melanoma Experimental/microbiologia , Melanoma Experimental/patologia , Camundongos , Camundongos Endogâmicos C57BL , Espectinomicina/metabolismoRESUMO
The influence of intestinal microflora and aging on the lipid metabolism in germ-free (GF) and conventional (CV) rats, 8 and 40 weeks old, was investigated. Serum cholesterol at the age of 8 and 40 weeks and serum triglyceride (TG) at the age of 40 weeks was higher in GF than in CV rats. Serum cholesterol decreased and serum TG and corticosterone tended to increase in both GF and CV rats with aging. In the rats 40 weeks of age, lipase activity of the pancreas and the duodenal, jejunal, and colorectal contents in GF rats increased, but that of the ileal and cecal contents in GF and CV rats decreased. Intestinal microflora tended to depress the age-related increase of serum TG and lipase activity of the pancreas and the duodenal and jejunal contents. Lipoprotein lipase (LPL) and hormone-sensitive lipase (HSL) activities of the epididymal adipose tissue were higher in CV than in GF rats at both 8 to 40 weeks of age. The LPL activity increased and the HSL activity decreased in both GF and CV rats with aging. The concentration of cholesterol increased and that of bile acids decreased in the cecal contents of 40-week-old GF rats.
Assuntos
Envelhecimento , Enterobacteriaceae/fisiologia , Vida Livre de Germes , Intestinos/microbiologia , Metabolismo dos Lipídeos , Animais , Ácidos e Sais Biliares/metabolismo , Colesterol/metabolismo , Corticosterona/sangue , Mucosa Intestinal/metabolismo , Lipase/metabolismo , Lipase Lipoproteica/metabolismo , Masculino , Pâncreas/enzimologia , Ratos , Triglicerídeos/sangueRESUMO
The activities of various enzymes involved in detoxication and carbohydrate metabolism in the liver and the gastrointestinal tract of germfree (GF) and conventional (CV) rats, 8 and 40 weeks' old, were measured in relationship to intestinal microflora and aging. In 8-week-old rats, the activities of nitroreductase (NR) and aniline hydroxylase (AH) in the liver, and of alkaline phosphatase (ALP), maltase and lactase in the duodenum were higher in GF than in CV rats, but the activities of arginosuccinate synthetase (ASS) and lactate dehydrogenase (LDH) in the liver were higher in CV than in GF rats. In 40-week-old rats, the activities of NR and glucose-6-phosphatase dehydrogenase (G-6-PDH) of the liver and ALP, maltase and lactase of the duodenum were higher in GF than in CV rats, but those of ASS, UDP-glucuronyl transferase (UDP-GT), AH, beta-glucuronidase, and LDH of the liver were higher in CV than in GF rats. Compared between 8- and 40-week-old rats the activities of NR, beta-glucuronidase, LDH, and acid phosphatase increased with aging in both GF and CV rats. The specific activities of ASS in CV and UDP-GT and AH in GF rats decreased with aging. The total activities of ASS and AH in GF rats also decreased with aging. The activities of ALP, maltase and lactase decreased with aging in both GF and CV rats. Thus, these data suggested that there are influences of indigenous intestinal microflora and aging on the activities of various enzymes in the liver and gastrointestinal tract.
Assuntos
Envelhecimento , Duodeno/enzimologia , Vida Livre de Germes , Intestinos/microbiologia , Fígado/enzimologia , Fosfatase Ácida/metabolismo , Anilina Hidroxilase/metabolismo , Animais , Glucosefosfato Desidrogenase/metabolismo , Glucuronidase/metabolismo , Glucuronosiltransferase/metabolismo , L-Lactato Desidrogenase/metabolismo , Masculino , Nitrocompostos/metabolismo , Nitrorredutases , Oxirredutases/metabolismo , Ratos , Ratos Endogâmicos F344RESUMO
The design, synthesis, and pharmacological evaluation of (S)-(-)-ethyl [6-[4-(morpholinoformimidoyl)benzamido]-3, 4-dihydro-2H-1-benzopyran-3-yl]acetate hydrochloride ((S)-4.HCl, MS-180), an orally active glycoprotein IIb-IIIa (GPIIb-IIIa) antagonist, are reported. Pharmacophore mapping of amidino and carboxyl groups of already known GPIIb-IIIa antagonists led to the synthesis of nine amidino acids containing 6,6-bicyclic ring skeletons (10a-i). Among them, the compounds 10a,c,e having an amide bond and 1,2,3,4-tetrahydronaphthalene or 3, 4-dihydro-2H-1-benzopyran skeleton showed marked inhibitions with IC50 values of 46-57 nM in human platelet aggregation assay in vitro, but low oral activities. N-Alkylation of the amidino group coupled with the ester prodrug approach afforded MS-180 ((S)-4.HCl), which generates in vivo the corresponding carboxylic acid (S)-3 as an active species. In vitro, (S)-3 inhibited ADP-induced aggregation of guinea pig, dog, and human platelets (IC50 = 110, 253, and 35 nM, respectively) and inhibited the binding of fibrinogen to immobilized GPIIb-IIIa of human platelets (IC50 = 0.12 nM). After oral administration of MS-180 ((S)-4.HCl) to fasted beagle dog, ex vivo inhibition of platelet aggregation was observed. The maximal inhibitions were observed 2-4 h after dosing with dose dependency (60% inhibition at a dose of 1 mg/kg, 85% at 3 mg/kg, and 100% at 10 mg/kg, respectively) and the extent of the inhibitions paralleled the plasma concentration of the active species (S)-3. On the basis of these studies, we selected MS-180 ((S)-4.HCl) as a candidate for clinical evaluation as a drug for the treatment and prevention of thrombosis in patients.
Assuntos
Acetatos/síntese química , Morfolinas/síntese química , Inibidores da Agregação Plaquetária/síntese química , Complexo Glicoproteico GPIIb-IIIa de Plaquetas/antagonistas & inibidores , Acetatos/administração & dosagem , Acetatos/química , Acetatos/farmacologia , Administração Oral , Animais , Cristalografia por Raios X , Cães , Fibrinogênio/antagonistas & inibidores , Fibrinogênio/metabolismo , Cobaias , Humanos , Técnicas In Vitro , Masculino , Modelos Moleculares , Morfolinas/administração & dosagem , Morfolinas/química , Morfolinas/farmacologia , Agregação Plaquetária/efeitos dos fármacos , Inibidores da Agregação Plaquetária/administração & dosagem , Inibidores da Agregação Plaquetária/química , Inibidores da Agregação Plaquetária/farmacologia , Complexo Glicoproteico GPIIb-IIIa de Plaquetas/metabolismo , Ligação Proteica , Estereoisomerismo , Relação Estrutura-AtividadeRESUMO
The purpose of this study was to investigate whether chronic administration of docosahexaenoic acid is able to reduce spatial cognitive deficit following transient ischemia in rats. In addition, we investigated whether the chronic treatment of docosahexaenoic acid is able to protect the hippocampal neuronal damage induced by either hypoxia in vitro or cerebral ischemia in vivo. A chronic administration of 200 mg/kg/day docosahexaenoic acid over 21 days did not affect the content of docosahexaenoic acid in the hippocampus, but did tend to increase it in the frontal cortex. On the other hand, this chronic administration decreased the content of arachidonic acid significantly both in the hippocampus and the frontal cortex. Under hypoxic conditions, the onset of the increase in the NADH fluorescence in the hippocampal slice was made significantly slower relative to the control by the chronic administration of docosahexaenoic acid. Rats were subjected to 10 min of transient forebrain ischemia by the method of four-vessel occlusion and were tested in a radial eight-arm maze task after cerebral reperfusion. Docosahexaenoic acid was administered either once 1 h before occlusion or daily for 21 days before occlusion. The single treatment of docosahexaenoic acid (1, 10, 100 or 200 mg/kg) did not significantly affect any aspect of the spatial learning deficit following occlusion. On the other hand, chronic treatment with docosahexaenoic acid (10, 100 or 200 mg/kg/day) significantly improved the spatial learning deficit following occlusion. A comparison of the neuronal densities in the hippocampal CA1 region of the chronically docosahexaenoic acid-treated (200 mg/kg/day) rats with those of the ischemic control revealed a significant neuronal preservation. From these results, it appears that chronic administration of docosahexaenoic acid may be valuable in ameliorating the spatial cognitive deficit induced by transient forebrain ischemia. In addition, docosahexaenoic acid might contribute to the protection of hippocampal neuronal damage caused by either hypoxia or ischemia.
Assuntos
Transtornos Cognitivos/prevenção & controle , Ácidos Docosa-Hexaenoicos/farmacologia , Ataque Isquêmico Transitório/psicologia , Aprendizagem em Labirinto/efeitos dos fármacos , Percepção Espacial/efeitos dos fármacos , Animais , Ácido Araquidônico/metabolismo , Encéfalo/patologia , Química Encefálica/efeitos dos fármacos , Transtornos Cognitivos/patologia , Transtornos Cognitivos/psicologia , Hipocampo/patologia , Ataque Isquêmico Transitório/patologia , Metabolismo dos Lipídeos , Masculino , NAD/metabolismo , Ratos , Ratos Wistar , Traumatismo por Reperfusão/tratamento farmacológico , Traumatismo por Reperfusão/psicologiaRESUMO
1. Histamine receptor-mediated modulation of the delayed outward potassium current (IK) was investigated in guinea-pig single ventricular cells by the whole-cell voltage clamp. 2. Histamine increased IK in a dose- dependent manner with a half-maximum dose of 3.8 x 10(-8) M. Histamine (10(-6) M) increased IK by a factor of 3.02 without a significant change in the current kinetics. The threshold dose of histamine for increasing IK was 10(-9) M and this value was similar to that for calcium current. 3. Cimetidine decreased IK in the presence of histamine, by shifting the dose-response curve to histamine to the right. The pA2 value of cimetidine against histamine was 6.38. 4. Forskolin did not increase IK after application of 10(-6) M histamine, and histamine scarcely increased IK in the presence of a heat-stable inhibitor of cyclic AMP-dependent protein kinase (PKI). 5. We conclude that stimulation by histamine of IK is mainly by way of the H2-receptor, and is mediated by cyclic AMP-dependent phosphorylation.
Assuntos
Histamina/farmacologia , Miocárdio/metabolismo , Canais de Potássio/efeitos dos fármacos , Animais , Canais de Cálcio/efeitos dos fármacos , Colforsina/farmacologia , Eletrofisiologia , Cobaias , Coração/efeitos dos fármacos , Antagonistas dos Receptores Histamínicos H1/farmacologia , Antagonistas dos Receptores H2 da Histamina/farmacologia , Técnicas In Vitro , Miocárdio/citologia , Potássio/fisiologia , Proteínas Quinases/farmacologia , Sódio/fisiologiaRESUMO
The effect of intragastric gavage administration of docosahexaenoic acid (DHA) on azoxymethane (AOM)-induced colon carcinogenesis in rats was studied. Male F344 rats were treated s.c. with 15 mg/kg of AOM once a week for 2 weeks and were given either 0.7 ml of DHA or water intragastrically twice a week starting the day before the first carcinogen treatment. The number of crypt multiplicity (number of crypts/focus) of aberrant crypt foci (ACF) in the colon were measured after 4, 12, and 36 weeks. The numbers and average crypt multiplicities of ACF induced by AOM were significantly lower after 12 and 36 weeks in animals given DHA. DHA also reduced the incidence of spontaneous ACF in animals without carcinogen treatment. Colorectal tumor incidence and number of tumors per rat after 36 weeks were slightly, but not significantly, lower in the DHA-treated group. These results suggest that DHA slightly suppresses colon carcinogenesis, and a possibility that warrants further study.
Assuntos
Anticarcinógenos , Carcinoma/induzido quimicamente , Neoplasias Colorretais/induzido quimicamente , Ácidos Docosa-Hexaenoicos/farmacologia , Animais , Azoximetano , Carcinoma/patologia , Colesterol/sangue , Neoplasias Colorretais/patologia , Ácidos Graxos/sangue , Masculino , Ratos , Ratos Endogâmicos F344 , Triglicerídeos/sangueRESUMO
A 3-year-old boy with congenital nemaline myopathy had generalized muscle weakness and hypotonia since birth. He developed cardiac symptoms at 2 years of age and died from congestive heart failure. At autopsy, the heart was markedly dilated, involving both ventricles. Rod bodies were recognized not only in skeletal muscles but in cardiac muscles on light and electron microscopy. Desmin and alpha-actinin, which constitute Z-line protein, were shown to localize in the rod structures in both skeletal and myocardial cells by immunohistochemistry. Seven cases of nemaline myopathy with cardiomyopathy have been reported in the literature. All of these patients were over 20 years of age, and the condition appeared mostly in the adult onset and the asymptomatic forms. This is the first infantile case of congenital nemaline myopathy which showed dilated cardiomyopathy with a fatal outcome.
Assuntos
Cardiomiopatia Dilatada/patologia , Músculos/ultraestrutura , Doenças Musculares/patologia , Cardiomiopatia Dilatada/complicações , Pré-Escolar , Proteínas do Citoesqueleto/metabolismo , Eletroforese em Gel de Poliacrilamida , Insuficiência Cardíaca/complicações , Humanos , Imuno-Histoquímica , Masculino , Músculos/metabolismo , Doenças Musculares/complicações , Doenças Musculares/congênito , Doenças Musculares/metabolismo , Miocárdio/metabolismo , Miocárdio/patologiaRESUMO
Cachexia frequently occurs in the late stages of cancer, and is difficult to manage. We previously reported that interleukin-6 (IL-6) cDNA transfection into Lewis lung carcinoma (LLC-IL6) induced cachexia-like symptoms in C57BL/6 mice. This was thought to be a useful experimental model of cancer cachexia. We have examined the effects of two eicosanoids, docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), in order to evaluate whether they could relieve cachexia. LLC-IL6-bearing animals were divided into three treatment groups receiving DHA, EPA or water as the control; 80-microliter samples of these compounds (purity > 95%) were administered orally by catheter daily starting 7 days after tumor transplantation. Tumor growth curves were similar in the three groups. There were no differences in water or food intake in the three groups. However, body weight, a marker of cachexia, was significantly higher in treated mice than in the control group. Sixteen days after tumor transplantation, the mean body weight was 17.45 g (P < 0.05), 17.2 g and 16.41 g in the groups receiving DHA, EPA and water respectively. The eicosanoids did not affect serum levels of IL-6. Ubiquitination of muscle protein, a marker of proteolysis coupled to cachexia, was compared in LLC-IL6- and LLC-transplanted mice. The eicosanoids prevented the ubiquitination of approximately 180 kDa protein. These results suggest that eicosanoids may prevent the cachexia mediated by IL-6.