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1.
Osteoporos Int ; 28(10): 2935-2944, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28668994

RESUMO

Fracture Risk Assessment Tool (FRAX) without bone mineral density (BMD) for hip fracture prediction was validated in a Norwegian population 50-90 years. Fracture risk increased with higher FRAX score, and the observed number of hip fractures agreed well with the predicted number, except for the youngest and oldest men. Self-reported fall was an independent risk factor for fracture in women. INTRODUCTION: The primary aim was to validate FRAX without BMD for hip fracture prediction in a Norwegian population of men and women 50-90 years. Secondary, to study whether information of falls could improve prediction of fractures in the subgroup aged 70-90 years. METHODS: Data were obtained from the third survey of the Nord-Trøndelag Health Study (HUNT3), the fracture registry in Nord-Trøndelag, and the Norwegian Prescription Database (NorPD), including 15,432 women and 13,585 men. FRAX hip without BMD was calculated, and hip fractures were registered for a median follow-up of 5.2 years. The number of estimated and observed fractures was assessed, ROC curves with area under the curve (AUC), and Cox regression analyses. For the group aged 70-90 years, self-reported falls the last year before HUNT3 were included in the Cox regression model. RESULTS: The risk of fracture increased with higher FRAX score. When FRAX groups were categorized in a 10-year percentage risk for hip fracture as follows, <4, 4-7.9, 8-11.9, and ≥12%, the hazard ratio (HR) for hip fracture between the lowest and the highest group was 17.80 (95% CI: 12.86-24.65) among women and 23.40 (13.93-39.30) in men. Observed number of hip fractures agreed quite well with the predicted number, except for the youngest and oldest men. AUC was 0.81 (0.78-0.83) for women and 0.79 (0.76-0.83) for men. Self-reported fall was an independent risk factor for fracture in women (HR 1.64, 1.20-2.24), and among men, this was not significant (1.09, 0.65-1.83). CONCLUSIONS: FRAX without BMD predicted hip fracture reasonably well. In the age group 70-90 years, falls seemed to imply an additional risk among women.


Assuntos
Acidentes por Quedas/estatística & dados numéricos , Fraturas por Osteoporose/etiologia , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Feminino , Seguimentos , Fraturas do Quadril/epidemiologia , Fraturas do Quadril/etiologia , Humanos , Masculino , Pessoa de Meia-Idade , Noruega/epidemiologia , Osteoporose/complicações , Osteoporose/epidemiologia , Fraturas por Osteoporose/epidemiologia , Sistema de Registros , Medição de Risco/métodos , Fatores de Risco , Autorrelato , Fatores Sexuais
2.
Biochimie ; 76(5): 423-7, 1994.
Artigo em Inglês | MEDLINE | ID: mdl-7849109

RESUMO

We have exposed the polychaete annelid Nereis diversicolor to heat shock or cadmium. Two-dimensional electrophoresis and fluorography techniques indicated the synthesis by the worms of at least 15 stress proteins including the universal one referred to as 'stress 70' and a lot of low molecular weight (LMW) proteins. 'Stress 70', synthesized by Nereis diversicolor in response to both stressors, appeared on fluorograms as an array of three charge isomers. We observed that most of the LMW stress proteins built up in response to heat shock were different from those observed after cadmium exposure. Furthermore, Nereis, which resists high levels of cadmium, did not appear to synthesize metallothioneins, small proteins known to prevent cellular damage by sequestering toxic metal ions. As no cadmium-binding proteins were visualized on fluorograms, the mechanism by which Nereis resists cadmium injury remains to be disclosed.


Assuntos
Cádmio/toxicidade , Proteínas de Choque Térmico/biossíntese , Poliquetos/metabolismo , Animais , Eletroforese em Gel Bidimensional , Temperatura Alta , Poliquetos/efeitos dos fármacos
3.
J Med Chem ; 35(13): 2481-96, 1992 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-1352353

RESUMO

A series of 70 triazine derivatives have been synthesized and tested for their capacity to modulate multidrug resistance (MDR) in DC-3F/AD and KB-A1 tumor cells in vitro, in comparison with verapamil (VRP), a calcium channel antagonist currently used in therapy as an antihypertensive drug, which also shows MDR modulating activity. Among the 12 selected compounds, 16 (S9788) showed high MDR reversing properties in vitro (300- and 6-fold VRP at 5 microM in DC-3F/AD and KB-A1 cells, respectively) and induced a strong accumulation of adriamycin. The relationship between the increase of ADR accumulation and the fold reversal induced by these compounds and their lack of effects on the sensitive DC-3F cells suggest that they act mainly by inhibiting the P-glycoprotein (Pgp) catalyzed efflux of cytotoxic agents, as already described for a majority of MDR modulators. In vivo, in association with the antitumor drug vincristine (0.25 mg/kg), 16 (100 mg/kg) increased the T/C by 39% in mice bearing the resistant tumor cell line P388/VCR. According to these interesting properties, 16 was selected for a clinical development because it was more bioavailable than 34, even though it was less active.


Assuntos
Antineoplásicos/farmacologia , Triazinas/farmacologia , Células Tumorais Cultivadas/efeitos dos fármacos , Membro 1 da Subfamília B de Cassetes de Ligação de ATP , Animais , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Cricetinae , Cricetulus , Resistência a Medicamentos , Sinergismo Farmacológico , Leucemia P388 , Pulmão/citologia , Pulmão/efeitos dos fármacos , Glicoproteínas de Membrana/metabolismo , Relação Estrutura-Atividade
4.
J Med Chem ; 43(11): 2165-75, 2000 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-10841795

RESUMO

A new series of imidazolyl nitrones spin traps has been synthesized and evaluated pharmacologically. The salient structural feature of these molecules is the presence of an imidazole moiety substituted by aromatic or heteroaromatic cycles. This connectivity imparts to the nitrone superior neuroprotective properties in vivo and in parallel reduced side effects and toxicity. Thus compound 6a (a 2-phenylimidazolyl nitrone) administered intraperitoneally protects (80%) mice from lethality induced by an intracerebroventricular administration of tert-butyl hydroperoxide (t-BHP) an oxidant capable of inducing neurodegenerative processes. Administration of the archetypal nitrone phenyl-tert-butyl nitrone (PBN) at an equimolar dose also affords some protection (60%) in this test. However, this activity is accompanied by hypothermia, whereas no such effect is apparent for 6a. Moreover, previously prepared nonsubstituted or alkyl-substituted imidazolyl nitrones were shown to be extremely toxic to rats in contrast to the compounds prepared in this study. The observed activities in vivo correlate well with the calculated partition coefficients (ClogP) and HOMO energy level.


Assuntos
Imidazóis/síntese química , Fármacos Neuroprotetores/síntese química , Óxidos de Nitrogênio/síntese química , Animais , Barreira Hematoencefálica/fisiologia , Temperatura Corporal/efeitos dos fármacos , Imidazóis/química , Imidazóis/farmacocinética , Imidazóis/farmacologia , Masculino , Camundongos , Fármacos Neuroprotetores/química , Fármacos Neuroprotetores/farmacocinética , Fármacos Neuroprotetores/farmacologia , Óxidos de Nitrogênio/química , Óxidos de Nitrogênio/farmacocinética , Óxidos de Nitrogênio/farmacologia , Ratos , Relação Estrutura-Atividade
5.
J Med Chem ; 39(20): 4099-108, 1996 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-8831775

RESUMO

A series of 36 purine and purine analog derivatives have been synthesized and tested for their ability to modulate multidrug resistance in vitro (P388/VCR-20 and KB-A1 cells) and in vivo (P388/VCR leukemia). Compounds were compared to S9788, a triazine derivative which has already shown some activity during phase 1 clinical trials and also a limiting cardiovascular side effect possibly linked to its calcium channel affinity. The fact that active compounds increase adriamycin accumulation in the resistant KB-A1 cells, and not in the sensitive KB-3-1 cells, suggests they act predominantly by inhibiting the P-glycoprotein-catalyzed efflux of cytotoxic agents. No direct relation was found between the affinity for the phenylalkylamine binding site of the calcium channel and in vitro sensitization of resistant cells. In vivo, when administered po in association with vincristine (0.25 mg/kg), five compounds (3, 4, 9, 25, and 26), of very differing calcium channel affinities (Ki from 5 to 560 nM), fully restored (T/V > or = 1.4) the sensitivity of P388/VCR leukemia to vincristine.


Assuntos
Antineoplásicos/síntese química , Resistência a Múltiplos Medicamentos , Purinas/síntese química , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Animais , Antineoplásicos/metabolismo , Antineoplásicos/uso terapêutico , Canais de Cálcio/metabolismo , Doxorrubicina/metabolismo , Feminino , Leucemia P388/tratamento farmacológico , Leucemia Experimental/tratamento farmacológico , Camundongos , Estrutura Molecular , Transplante de Neoplasias , Piperidinas/uso terapêutico , Purinas/metabolismo , Purinas/uso terapêutico , Relação Estrutura-Atividade , Triazinas/uso terapêutico , Células Tumorais Cultivadas , Vincristina/uso terapêutico
6.
Dev Comp Immunol ; 12(2): 279-85, 1988.
Artigo em Inglês | MEDLINE | ID: mdl-3384157

RESUMO

Methods for obtaining coelomocyte populations from Nereis diversicolor by selective agglutination have been developed. Two main types of granulocytes have been successfully separated and recovered using respectively galactose and fucose specific lectins. 85 to 90% of the separated cells were viable.


Assuntos
Anelídeos/citologia , Separação Celular/métodos , Granulócitos , Lectinas/farmacologia , Animais , Sobrevivência Celular , Fucose , Galactose , Granulócitos/efeitos dos fármacos
7.
Dev Comp Immunol ; 12(1): 1-15, 1988.
Artigo em Inglês | MEDLINE | ID: mdl-2832223

RESUMO

Studies on membrane receptors have been performed on the Nereis coelomocytes using various lectins. In the agglutination assay, only LCA and WGA appeared nonreactive. Fluorescent lectins showed the poor reactivity of the eleocytes and the diversity of the receptors according to the granulocyte types. Types I-granulocytes reacted only with Con A. Type II-granulocyte membrane contained mannose and galactose receptors (reactivity with Con A, PNA and SBA). The type III-granulocyte membrane revealed the presence of mannose and fucose receptors (UEA, AAA). Electron microscope investigations with HRP-DAB or mannosyl labelled Con A, RCAI and LTA have confirmed the distribution of the membrane receptors.


Assuntos
Lectinas Tipo C , Lectinas de Ligação a Manose , Poliquetos/imunologia , Receptores Mitogênicos/metabolismo , Animais , Fluorescência , Granulócitos/imunologia , Granulócitos/metabolismo , Granulócitos/ultraestrutura , Receptor de Manose , Microscopia Eletrônica , Poliquetos/citologia , Poliquetos/metabolismo , Receptores de Superfície Celular/metabolismo , Receptores Imunológicos/metabolismo
8.
Cancer Chemother Pharmacol ; 30(6): 491-4, 1992.
Artigo em Inglês | MEDLINE | ID: mdl-1394807

RESUMO

S 9788, a new triazinoaminopiperidine derivative, was found to be a potent reversant of vincristine resistance in the in vivo murine leukemic P388/VCR model. In two treatment regimens (Q4D days 1, 5 and 9 and QD days 1-9), S 9788 enhanced the antitumor activity of vincristine in a dose-dependent manner, resulting in a complete circumvention of drug resistance for well-tolerated doses of S 9788. S 9788 was also effective in enhancing therapeutic effects of vincristine in the treatment of sensitive P388-bearing mice. These results strongly suggest that S 9788 may be a potential candidate for circumvention of multidrug resistance (MDR) in clinical practice.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Leucemia P388/tratamento farmacológico , Piperidinas/farmacologia , Triazinas/farmacologia , Vincristina/uso terapêutico , Animais , Relação Dose-Resposta a Droga , Esquema de Medicação , Avaliação Pré-Clínica de Medicamentos , Resistência a Medicamentos/genética , Feminino , Leucemia P388/genética , Camundongos , Camundongos Endogâmicos , Piperidinas/administração & dosagem , Triazinas/administração & dosagem , Vincristina/administração & dosagem
9.
Fundam Clin Pharmacol ; 10(5): 458-66, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-8902549

RESUMO

The effects of S 12370 (2-[4-benzhydryloxypiperidinoethyl]isoxindole), were studied in vitro. In guinea pig isolated tracheal rings, S 12370 induced a similar competitive inhibition of the contractile responses produced by acetylcholine, histamine and serotonin. However, it did not affect the contractions induced by leukotriene D4 (LTD4), substance P and U 46619, a stable analogue of thromboxane A2. S 12370 induced a concentration dependent inhibition of the cholinergic component of the contraction induced by electrical field stimulation, whereas it did not influence the sustained nonadrenergic noncholinergic (NANC) excitatory response observed in guinea pig isolated bronchi. S 12370 did not influence the relaxations induced by prostaglandin E2, isoprenaline and salbutamol, and did not modify the nonadrenergic noncholinergic inhibitory response induced by electrical field stimulation. In isolated left atria, the negative inotropic effect of acetylcholine was competitively inhibited by S 12370. In binding experiments, S 12370 exhibited similar affinity for M1, M2, M3, M4 muscarinic receptors and also recognized 5-HT2 serotonin and H1 histamine receptor subtypes. In ovalbumin-sensitized animals, the contractile response of isolated tracheal rings produced by exposure to the allergen was not influenced by S 12370. Tracheal rings from sensitized animals preexposed in vitro to the allergen developed a hyporesponsiveness to beta-adrenoceptor stimulation. S 12370 prevented the inhibitory effect caused by ovalbumin immune sensitization in the relaxation to isoprenaline. In rat polymorphonuclear neutrophil (PMN) cells, S 12370 up to 10(-5) M did not inhibit the arachidonic acid metabolism. These results suggest that in guinea pig tracheal smooth muscle, S 12370 is a competitive inhibitor of muscarinic, serotonin and histamine receptors and can modulate the beta-adrenergic dysfunction induced by immune sensitization. S 12370 may present some therapeutic interest in inflammatory airway diseases.


Assuntos
Compostos Benzidrílicos/farmacologia , Músculo Liso/efeitos dos fármacos , Ovalbumina/toxicidade , Vasoconstritores/toxicidade , Vasodilatadores/farmacologia , Ácido 15-Hidroxi-11 alfa,9 alfa-(epoximetano)prosta-5,13-dienoico , Acetilcolina/toxicidade , Animais , Ácido Araquidônico/metabolismo , Compostos Benzidrílicos/metabolismo , Ligação Competitiva , Estimulação Elétrica , Cobaias , Coração/efeitos dos fármacos , Histamina/toxicidade , Leucotrieno D4/toxicidade , Pulmão/efeitos dos fármacos , Pulmão/metabolismo , Masculino , Contração Muscular/efeitos dos fármacos , Músculo Liso/metabolismo , Músculo Liso Vascular/efeitos dos fármacos , Oxindóis , Endoperóxidos Sintéticos de Prostaglandinas/toxicidade , Ratos , Receptores Adrenérgicos beta/efeitos dos fármacos , Receptores Adrenérgicos beta/metabolismo , Serotonina/toxicidade , Substância P/toxicidade , Tromboxano A2/análogos & derivados , Tromboxano A2/toxicidade
10.
Arch Anat Microsc Morphol Exp ; 65(3): 183-207, 1976.
Artigo em Francês | MEDLINE | ID: mdl-1024484

RESUMO

The investigation was carried out on two Cephalopods: Sepia officinalis and Loligo vulgaris. During previtellogenesis, the follicle cells (F.C.), originally arranged at the periphery of the oocyte, form strands, through the axis of which runs a blood vessel. The follicle strands then make their way down into the ooplasm. They end up by occuping the greater part of the volume of the oocyte. At this stage, despite their increase in size, the F.C. do not undergo conspicuous cytological transformations. In the ooplasm, excepting a few specialized structures (annulate lamellae), the organites display no notable differentiation. The onset of vitellogenesis is characterized by the appearance in the ooplasm of elements paracrystalline in structure. A zona pellucida appears between the oocyte and the F.C., and it is at the point that yolk of a permanent type begins to accumulate. Concurrently the F.C. undergo characteristic reorganization: hypertrophy of the nucleolar mass, multiplication of granular reticulum cisternae, increase both in the number and the size of the Golgi complexes. The saccules of the Golgi complex process a material rich in carbohydrate protein bearing the same cytochemical characteristics as the yolk. In the basal zone of the F.C., deep invaginations of the wall of blood vessels scallop the cytoplasm. F.C. look like "podocyte cells". Immunofluorescence study suggest there is no immunological identity between blood and yolk proteins. The formation of chorion is accompanied by a fresh transformation of the F.C.: the granular endoplasmic reticulum breaks up into rounded cisternae containing a dense material. Concurrently the morphology of the Golgi complex is modified. The earliest chorion elements accumulate, firstly in the forme of isolated lobules within the zona pellucida. They then fuse to make a continous layer bounding the microvilli of the F.C. These cells eventually enter into a phase of degeneration and disappear, whilst the oocyte is set free by dehiscence into coelomic cavity.


Assuntos
Artrópodes/fisiologia , Oócitos/fisiologia , Óvulo/fisiologia , Animais , Córion/fisiologia , Gema de Ovo/fisiologia , Feminino , Oogênese , Fatores de Tempo , Membrana Vitelina/fisiologia
11.
Respir Physiol ; 105(3): 225-33, 1996 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8931182

RESUMO

The present study was designed to point out similarities between the effects on pulmonary circulation caused by hypoxia and by a chemoreceptor stimulant (S1867, an almitrine analog). Isolated rat lungs were perfused at a constant flow with homologous blood and ventilated under normoxic, hypoxic or hyperoxic conditions. (1) At 0.25 microgram/ml, S1867 potentiated the hypoxic pressor response, while at 1 microgram/ml, it induced a significant increase in pulmonary artery pressure (PAP) at 21% O2. (2) Since the expression of an oxygen-binding protein (NADPH-oxidase like) has been demonstrated in the rat carotid bodies, we studied the effects of the NADPH-oxidase inhibitor diphenyleneiodonium (DPI) on HPV and on S1867-induced pulmonary vascular responses. Both responses were totally abolished by DPI (40 microM), whereas the vasoconstriction induced by a thromboxane A2 analog (U46619) remained unchanged. (3) Vascular responses to hypoxia and S1867 (1 microgram/ml) were both reversed by a bolus of the sulfhydryl oxidant diamide (3 mg). (4) The S1867-induced response was prevented and reversed by the supply of inhaled oxygen, which was without action on the vasoconstriction induced by U46619. These results suggest that the almitrine analog and hypoxia act at least partly through the same cellular mechanism, involving a DPI-sensitive protein.


Assuntos
Almitrina/análogos & derivados , Hipóxia/etiologia , Hipóxia/fisiopatologia , Medicamentos para o Sistema Respiratório/farmacologia , Ácido 15-Hidroxi-11 alfa,9 alfa-(epoximetano)prosta-5,13-dienoico , Almitrina/farmacologia , Animais , Pressão Sanguínea/efeitos dos fármacos , Células Quimiorreceptoras/efeitos dos fármacos , Células Quimiorreceptoras/fisiopatologia , Modelos Animais de Doenças , Inibidores Enzimáticos/farmacologia , Técnicas In Vitro , Masculino , NADPH Oxidases/antagonistas & inibidores , Óxido Nítrico Sintase/antagonistas & inibidores , Oniocompostos/farmacologia , Perfusão , Endoperóxidos Sintéticos de Prostaglandinas/farmacologia , Artéria Pulmonar/efeitos dos fármacos , Artéria Pulmonar/fisiopatologia , Circulação Pulmonar/efeitos dos fármacos , Circulação Pulmonar/fisiologia , Ratos , Ratos Sprague-Dawley , Tromboxano A2/análogos & derivados , Tromboxano A2/farmacologia , Vasoconstrição/efeitos dos fármacos , Vasoconstrição/fisiologia
12.
Arch Biol (Liege) ; 87(3): 283-302, 1976.
Artigo em Francês | MEDLINE | ID: mdl-1020948

RESUMO

The effect produced by an eyestalk removal have been studied on Eriocheir females at different physiological stages. In juvenile and prepuberal crabs, the operation induces an important rise of the oocyte diameter. Only a few variations are observed in puberal females oocytes. Cytological changes are found at first at the nucleolar level. The granular area increases and the nucleolar vacuoles volume decreases. Then the granules (precursor material to endogenous yolk) disappear in the reticulum cisternae. At this time, the endogenous yolk seems essentially elaborated within yolk lobules. The envelope of these lobules is enhanced by ribosomes. In juvenile females (oocytes initially in previtellogenesis) exogenous yolk does not appear. Nevertheless in prepuberal females, following eyestalks deprivation, the oocytes, initially at the endogenous vitellogenesis stage, quickly reach the vitellogenesis second stage. In such oocytes, the microvilli development and pinocytose vesicles number are greater than normally. Cytochemical tests reactions do not demonstrate differences in the yolk material (endogenous and exogenous) nature from experimented oocytes and controls. In juvenile and prepuberal oocytes, the multivesicular bodies and lysosomes proliferation, the increase in glycogen and lipids amount express a metabolic disturbance resulting from an acceleration of growth processes. However in eyestalk-less prepuberal females no difference with the control oocytes was noticed.


Assuntos
Braquiúros/fisiologia , Oogênese , Animais , Braquiúros/anatomia & histologia , Feminino , Sistemas Neurossecretores/fisiologia , Oócitos/ultraestrutura
13.
Cell Mol Biol (Noisy-le-grand) ; 39(1): 105-14, 1993 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-8467236

RESUMO

Based on partial amino acid sequence of an antibacterial-metalloprotein (MPII) consisting of a N-terminal fragment (1-33th) and an 43 amino acids long internal fragment, two oligonucleotides primers were synthesized and used to generate a cDNA fragment by the PCR method. The specificity of the PCR synthesized 220 bp fragment was verified by hybrid-arrest translation and sequencing. In situ hybridization performed with this cDNA fragment on Nereis diversicolor whole body defined two specific sites of recognition: a cluster of cells floating in the coelom and two types of muscles (perineural and oblique). Finally, the chronological expression of the MPII was postulated.


Assuntos
Antibacterianos/biossíntese , Metaloproteínas/genética , Poliquetos/genética , RNA Mensageiro/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Clonagem Molecular , Sondas de DNA , Hibridização In Situ , Dados de Sequência Molecular , Reação em Cadeia da Polimerase
14.
Arch Environ Contam Toxicol ; 33(2): 203-8, 1997 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9294250

RESUMO

A toxicity test for organophosphates (OP) and carbamates (C) was improved with the adult ragworm Nereis diversicolor. Animals were maintained in U-shaped glass tubes of 4-mm inner diameter fixed vertically on a plastic plate and placed in glass aquaria. Each tank was covered with glass in order to reduce evaporation and heat dissipation. Temperature varied between 15 and 16 degrees C and salinity was constant (34 per thousand) during the entire length of the experiment. Experiments were performed with a fixed day length of 12 h and seawater was gently aerated. The maintenance system allowed the administration of OP and C compounds via the seawater. An acclimatization period of 48 h was not sufficient to accomodate worms to their artificial burrows; accordingly, we chose to acclimate worms for a week before beginning the exposure. Choline acetyltransferase (ChAT) activity was very low and was not significantly modified by two OP compounds: malathion and parathion-ethyl. ChAT is not a target for these pesticides and should not be used for future studies about OP and C toxicity. On the other hand, inhibitory effects on acetylcholinesterase (AChE) activity were determined at concentrations of 10(-6) M for three OP compounds-malathion, parathion-ethyl, and phosalone-and a carbamate pesticide-carbaryl. We measured only short-term effects and no cumulative effect was determined, the maximum percentage of AChE activity inhibition being between 2 (carbaryl) and 7 (OP compounds) days after exposure and then remaining stable. Mortality occured only after a period of intoxication of 14 days. N diversicolor, which can be easily maintained at the laboratory, seems to be a good candidate for future laboratory studies to test the toxicity of other pollutants.


Assuntos
Carbamatos , Colina O-Acetiltransferase/antagonistas & inibidores , Inibidores da Colinesterase/toxicidade , Inseticidas/toxicidade , Compostos Organofosforados , Poliquetos/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Animais , Testes de Toxicidade
15.
Biol Bull ; 190(3): 396-402, 1996 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29227704

RESUMO

This study constitutes the first report of a biochemical characterization, involving both substrates and inhibitors and electrophoretic analysis, of a cholinesterase (ChE) from a polychaete annelid (Nereis diversicolor). The ChE of N. diversicolor appears to be an acetylcholinesterase (AChE); i.e., it hydrolyzes acetylthiocholine iodide at a higher rate than other substrates and is inhibited by eserine but not by iso-OMPA. The ChEs of Eisenia fetida are different from that of N. diversicolor and include at least two types of PrChEs. The AChE activity is located principally in the anterior region of the worm (head) in N. diversicolor, whereas the ChE activity of E. fetida is located throughout the body. The electrophoretic characterization of N. diversicolor and E. fetida ChEs showed, respectively, six and two isoforms with disc-PAGE, and three (55,000, 47,000, and 17,000) and five molecular forms (628,000, 301,000, 235,000, 106,000, and 53,800) with PAGGE; substantial activity remained at the top of the PAGGE gel in both species.

16.
Invest New Drugs ; 10(3): 137-48, 1992 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-1428723

RESUMO

S 9788 is a novel triazinoaminopiperidine derivative which does not belong to any of the classes of compounds known to reverse multidrug resistance (MDR). S 9788 was far more potent than verapamil (VRP) in reversing resistance to adriamycin (ADR) in the ADR-selected murine leukaemia cell lines P388/ADR-1 and P388/ADR-10, and the human chronic myelogenous leukaemia K562/R. Fold reversion with S 9788 (5 microM) was, respectively, 3.5, 5.4 and 11.3 times greater than that with VRP (5 microM). S 9788 was also a more potent reversant of ADR resistance in the intrinsically resistant human colon adenocarcinoma COLO 320DM (2.3 fold), and of vincristine (VCR) resistance in the human MDR1 gene-transfected squamous lung carcinoma line S1/tMDR1 (5.6 fold). The activity of S 9788 depended on both the MDR cell line and the cytotoxic agent. S 9788 (50-100 mg/kg/d) administered IP once a day on days 1-4 resulted in a dose-dependent increase in the chemotherapeutic effect of VCR (0.25 mg/kg/d) in P388/VCR - bearing mice and ADR (4 mg/kg/d) in P388/ADR - bearing mice. Increases in antitumor activity were (% T/C) of +20-34% in the P388/ADR model and + 50-78% in the P388/VCR model with respect to cytotoxic agent treatment alone. S 9788 appeared to be devoid of toxicity at its effective doses. The mechanism of action of S 9788 is unknown but S 9788 (0.5-10 microM) induced a dose-dependent increase in ADR accumulation in KB-Al cells and compared to verapamil its effect was twice as active and approximately seven times more potent. We conclude that S 9788 is a novel agent capable of reversing MDR in vitro and in vivo, and whose pharmacological profile warrants its selection as a candidate drug for eventual assessment in the clinic.


Assuntos
Antineoplásicos/uso terapêutico , Leucemia P388/tratamento farmacológico , Piperidinas/uso terapêutico , Triazinas/uso terapêutico , Animais , Linhagem Celular , Doxorrubicina/farmacologia , Interações Medicamentosas , Citometria de Fluxo , Humanos , Camundongos , Vincristina/farmacologia
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