Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Resultados 1 - 20 de 144
Filtrar
1.
Lett Appl Microbiol ; 67(4): 343-347, 2018 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-30015352

RESUMEN

Excessive expansion of Staphylococcus aureus is associated with several skin diseases, including atopic dermatitis (AD). Recently, we have demonstrated that washing skins with ultra-pure soft water containing little bivalent metal ions improved skin conditions of atopic subjects. In this study, we investigated the roles of calcium or magnesium on the proliferation of S. aureus both in vitro and in vivo. Depletion of calcium and magnesium in the culture medium significantly suppressed the expansion of S. aureus growth. When S. aureus, diluted with water containing calcium/magnesium at the concentration of medium-hard water (83·0 mg l-1 as CaCO3 ) or the one that contains little calcium/magnesium, was applied onto the tape-stripped skin of Hos:HR-1 mice, growth of S. aureus in water without those minerals on the skin was suppressed. These results suggest that depletion of both calcium and magnesium abrogate the proliferation of S. aureus not only in the culture system but also on the skin surface of mice. Since colonization of S. aureus on the skin is well-known to exacerbate AD symptoms, usage of ultra-pure soft water containing less calcium and magnesium may improve the skin condition through the suppression of S. aureus growth on the skin of patients with skin problems. SIGNIFICANCE AND IMPACT OF THE STUDY: This study demonstrates the importance of calcium and magnesium for the colonization and growth of Staphylococcus aureus by using both in vitro culture systems and in vivo experiments on the murine skin. Our results indicate that the removal of these metal ions is probably beneficial for protecting the skin from S. aureus. Thus, using ultra-pure soft water without metal ions may improve the skin condition of patients with skin problems through the protection from S. aureus colonization.


Asunto(s)
Cloruro de Calcio/farmacología , Dermatitis Atópica/microbiología , Cloruro de Magnesio/farmacología , Piel/microbiología , Staphylococcus aureus/crecimiento & desarrollo , Animales , Calcio/análisis , Femenino , Humanos , Magnesio/análisis , Masculino , Ratones , Infecciones Estafilocócicas/microbiología , Staphylococcus aureus/aislamiento & purificación
2.
J Appl Microbiol ; 120(2): 280-8, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26606689

RESUMEN

AIMS: Skin colonization of Staphylococcus spp. critically affects the severity of dermatitis in humans and animals. We examined different types of fatty acid salts for their antibacterial activity against Staphylococcus spp. when used in ultrapure soft water (UPSW). We also evaluated their therapeutic effect on a spontaneous canine model of dermatitis. METHODS AND RESULTS: UPSW, in which Ca(++) and Mg(++) were replaced with Na(+) , was generated using a water softener with cation-exchange resin. Staphylococcus aureus (Staph. aureus), Staphylococcus intermedius (Staph. intermedius), and Staphylococcus pseudintermedius (Staph. pseudintermedius) were incubated with various fatty acid salts in distilled water (DW) or UPSW and the number of bacteria was counted. Among the fatty acids, oleic acid salt and linoleic acid (LA) salt reduced the number of these bacteria. Also, UPSW enhanced the antibacterial effect of LA on Staph. spp. In spontaneously developed itchy dermatitis in companion dogs, shampoo treatment with liquid soap containing 10% LA in UPSW improved skin conditions. CONCLUSIONS: LA salt showed antibacterial activity against Staph. spp. Treatment with soap containing LA with UPSW reduced clinical conditions in dogs with dermatitis. SIGNIFICANCE AND IMPACT OF THE STUDY: Because colonization of Staph. spp. on the skin exacerbates dermatitis, the use of LA-containing soap in UPSW may reduce unpleasant clinical symptoms of the skin.


Asunto(s)
Antibacterianos/administración & dosificación , Dermatitis/veterinaria , Enfermedades de los Perros/tratamiento farmacológico , Ácido Linoleico/administración & dosificación , Infecciones Estafilocócicas/veterinaria , Staphylococcus/efectos de los fármacos , Agua/administración & dosificación , Animales , Dermatitis/tratamiento farmacológico , Dermatitis/microbiología , Enfermedades de los Perros/microbiología , Perros , Ácido Oléico , Piel/microbiología , Jabones , Infecciones Estafilocócicas/tratamiento farmacológico , Infecciones Estafilocócicas/microbiología , Staphylococcus/fisiología , Agua/química
3.
Niger J Med ; 24(2): 179-82, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26353431

RESUMEN

BACKGROUND: The syndrome of catatonia appears to exist with many conditions, yet goes undetected by the skillful eyes of clinicians. This case which is rarely reported in literatures shows the effectiveness of antipsychotic augmenting in a persistent catatonic schizophrenia disorder. METHOD: This is a case narration of persistent catatonia in a 24-years old pregnant Nigerian woman with schizophrenia disorder. RESULTS: First line management with benzodiazepines and electroconvulsive therapy (ECT) failed to resolve the syndrome which later responded to Electroconvulsive Therapy with low dose antipsychotic augmentation. CONCLUSIONS: Cautious augmenting of electroconvulsive therapy with neuroleptics may be a quick and relatively safe procedure in the relief of schizophrenia with catatonia in pregnancy.


Asunto(s)
Antipsicóticos/administración & dosificación , Terapia Electroconvulsiva/métodos , Complicaciones del Embarazo , Esquizofrenia Catatónica , Terapia Combinada/métodos , Manejo de la Enfermedad , Relación Dosis-Respuesta a Droga , Femenino , Humanos , Embarazo , Complicaciones del Embarazo/diagnóstico , Complicaciones del Embarazo/terapia , Esquizofrenia Catatónica/diagnóstico , Esquizofrenia Catatónica/terapia , Resultado del Tratamiento , Adulto Joven
4.
J Appl Microbiol ; 115(3): 711-7, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23826728

RESUMEN

AIMS: Scedosporium apiospermum sometimes causes serious infectious diseases on the skin of immunodeficient subjects. Antifungal effects of fatty acid salts in soap against S. apiospermum were investigated under different water conditions. METHODS AND RESULTS: Ultrapure soft water (UPSW) was generated by the water softener with cation-exchange resin. The calcium and magnesium ions were replaced with sodium ions in UPSW. Scedosporium apiospermum was incubated with different fatty acid salts that constituted soap in distilled water (DW), tap water (TW) and UPSW. After incubation, the number of fungi was counted. Among the fatty acids, palmitic acid salt (C16) reduced the number of S. apiospermum. UPSW enhanced the antifungal effect of C16 on S. apiospermum. The absence of both calcium and magnesium ions and the existence of sodium chloride in UPSW were responsible for its antifungal effect. In addition, repeated short-term treatment with UPSW and C16 decreased the number of S. apiospermum. CONCLUSIONS: Antifungal effects of C16 on S. apiospermum were demonstrated. Moreover, the use of UPSW promoted the antifungal effect of C16. SIGNIFICANCE AND IMPACT OF STUDY: This study provides the preventive method for diseases associated with S. apiospermum infection using novel palmitic acid soap in UPSW.


Asunto(s)
Antifúngicos/farmacología , Ácido Palmítico/farmacología , Scedosporium/efectos de los fármacos , Agua/farmacología , Sales (Química)/farmacología , Jabones/química , Cloruro de Sodio/farmacología , Agua/química , Purificación del Agua , Ablandamiento del Agua
5.
J Clin Pharm Ther ; 35(3): 323-32, 2010 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-20831533

RESUMEN

OBJECTIVES: Renal transplant recipients are thought to have an increased risk of hyperuricaemia (HU); therefore, the effects of plasma uric acid (UA) on the pharmacokinetics (PK) of cyclosporine A (CyA), an immunosuppressant, in renal transplant recipients and experimental animals were investigated. METHODS: An open-label, non-randomized, retrospective study was performed in renal transplant recipients. Data from 76 subjects who received a renal transplantation with CyA medication were included. We compared the PK of CyA of recipients showing a high UA level with the other recipients. In addition, PK studies were performed using hyperuricaemic-model rats (HU rats) prepared by subcutaneous injection of the uricase inhibitor, potassium oxonate and intraperitoneal injection of UA. RESULTS: The area under the blood concentration vs. time curve (AUC) up to 9 h, the blood level at 2 h after dose and peak level in high UA recipients (UA > 7.0 mg/dL) was significantly lower (about 10-16%) than that in the other recipients, although there were no differences in dose, and the trough blood level. On the contrary, there were no differences in PK parameters after intravenous administration of CyA between HU and control rats; however, AUC, peak level and bioavailability in HU rats (2.01 ± 0.56 µg h/mL, 0.47 ± 0.26 µg/mL and 0.186 ± 0.05, respectively) after oral administration were significantly lower than in the control animals (6.13 ± 0.97 µg h/mL, 0.82 ± 0.17 µg/mL and 0.458 ± 0.07 µg/mL, respectively). In addition, the absorptions of CyA and midazolam, an ideal probe for CYP3A, from the intestinal loop in HU rats were significantly less (about 50% and 37%, respectively) than in the controls. CONCLUSIONS: The absorption of CyA was affected by plasma UA in transplant recipients and experimental rats. The contribution of intestinal metabolism by CYP3A to decreasing CyA absorption in HU rats was significant. These results suggest that transplant recipients with high UA may have poor absorption of CyA.


Asunto(s)
Ciclosporina/farmacocinética , Inmunosupresores/farmacocinética , Trasplante de Riñón , Ácido Úrico/sangre , Adolescente , Adulto , Anciano , Animales , Área Bajo la Curva , Citocromo P-450 CYP3A/metabolismo , Femenino , Humanos , Masculino , Persona de Mediana Edad , Ratas , Ratas Wistar , Estudios Retrospectivos , Adulto Joven
6.
Lab Chip ; 18(16): 2466-2476, 2018 08 07.
Artículo en Inglés | MEDLINE | ID: mdl-30033460

RESUMEN

Understanding the complex 3D tumor microenvironment is important in cancer research. This microenvironment can be modelled in vitro by culturing multicellular tumor spheroids (MCTS). Key challenges when using MCTS in applications such as high-throughput drug screening are overcoming imaging and analytical issues encountered during functional and structural investigations. To address these challenges, we use an ultrasonic standing wave (USW) based MCTS culture platform for parallel formation, staining and imaging of 100 whole MCTS. A protein repellent amphiphilic polymer coating enables flexible production of high quality and unanchored MCTS. This enables high-content multimode analysis based on flow cytometry and in situ optical microscopy. We use HepG2 hepatocellular carcinoma, A498 and ACHN renal carcinoma, and LUTC-2 thyroid carcinoma cell lines to demonstrate (i) the importance of the ultrasound-coating combination, (ii) bright field image based automatic characterization of MTCS, (iii) detailed deep tissue confocal imaging of whole MCTS mounted in a refractive index matching solution, and (iv) single cell functional analysis through flow cytometry of single cell suspensions of disintegrated MTCS. The USW MCTS culture platform is customizable and holds great potential for detailed multimode MCTS analysis in a high-content manner.


Asunto(s)
Acústica , Microtecnología/instrumentación , Imagen Molecular/instrumentación , Esferoides Celulares/patología , Línea Celular Tumoral , Citometría de Flujo , Humanos , Temperatura , Microambiente Tumoral , Ondas Ultrasónicas
7.
Oncogene ; 36(19): 2643-2654, 2017 05 11.
Artículo en Inglés | MEDLINE | ID: mdl-27893718

RESUMEN

Pancreatic ductal adenocarcinoma (PDAC) is one of the most fatal types of cancer and the 5-year survival rate is only 5%. Several studies have suggested that cancer stem cells (CSCs) are thought to be involved in recurrence and metastasis and so it is essential to establish an approach targeting CSCs. Here we have demonstrated that cyclic guanosine monophosphate (cGMP) suppressed CD44 expression and the properties of CSCs in PDAC. Microarray analysis suggested that cGMP inhibited Forkhead box O3 (FOXO3), which is known as a tumor suppressor. Surprisingly, our data demonstrated that FOXO3 is essential for CD44 expression and the properties of CSCs. Our data also indicated that patients with high FOXO3 activation signatures had poor prognoses. This evidence suggested that cGMP induction and FOXO3 inhibition could be ideal candidates for pancreatic CSC.


Asunto(s)
Adenocarcinoma/genética , Biomarcadores de Tumor/genética , Carcinoma Ductal Pancreático/genética , Proteína Forkhead Box O3/genética , Receptores de Hialuranos/genética , Adenocarcinoma/patología , Animales , Biomarcadores de Tumor/biosíntesis , Carcinoma Ductal Pancreático/patología , Línea Celular Tumoral , GMP Cíclico/metabolismo , Proteína Forkhead Box O3/biosíntesis , Regulación Neoplásica de la Expresión Génica , Humanos , Receptores de Hialuranos/biosíntesis , Ratones , Análisis por Micromatrices , Metástasis de la Neoplasia , Células Madre Neoplásicas/metabolismo , Células Madre Neoplásicas/patología , Pronóstico , Ensayos Antitumor por Modelo de Xenoinjerto
8.
Biochim Biophys Acta ; 1217(2): 229-31, 1994 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-8110842

RESUMEN

Two cDNA clones, pHSj31 and pHSj3, coding for CYP2E1 were isolated from a hamster liver cDNA library. The sequence analyses revealed that they encoded the same polypeptide of 493 amino acid residues (M(r) = 56,616) and differed from the length of their 3'-untranslated region. The deduced amino acid sequence of hamster CYP2E1 showed approx. 90% identities with those of the rats and mice, and approx. 80% identities with those of the rabbits, monkeys and humans. The NH2-terminal 35 deduced amino acid sequences of hamster CYP2E1 were completely identical with purified protein, ha P-450j. The Northern blot analysis showed that CYP2E1 was expressed in livers and to lesser extents in kidneys and lungs.


Asunto(s)
Sistema Enzimático del Citocromo P-450/genética , Oxidorreductasas N-Desmetilantes/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Clonación Molecular , Cricetinae , Citocromo P-450 CYP2E1 , Sistema Enzimático del Citocromo P-450/química , Sistema Enzimático del Citocromo P-450/aislamiento & purificación , ADN Complementario/química , ADN Complementario/aislamiento & purificación , Femenino , Hígado/enzimología , Mesocricetus , Datos de Secuencia Molecular , Oxidorreductasas N-Desmetilantes/química , Oxidorreductasas N-Desmetilantes/aislamiento & purificación
9.
J Mol Biol ; 295(5): 1275-88, 2000 Feb 04.
Artículo en Inglés | MEDLINE | ID: mdl-10653703

RESUMEN

The effects of lacking a specific disulfide bridge on the transition state in folding were examined in order to explore the folding-unfolding mechanism of lysozyme. Four species of three-disulfide variant of hen lysozyme (3SS-lysozyme) were prepared by replacing two Cys residues with Ala or Ser: C6S/C127A, C30A/C115A, C64A/C80A and C76A/C94A. The recombinant hen lysozyme was studied as the standard reference containing four authentic disulfide bridges and the extra N-terminal Met: the recombinant hen lysozyme containing the extra N-terminal. Folding rates were measured by monitoring the change in fluorescence intensity associated with tri-N-acetyl-d-glucosamine binding to the active site of refolded lysozyme. It was confirmed that the folding rate of the recombinant hen lysozyme containing the extra N-terminal was the same as that of wild-type lysozyme, and that the folding rate was little affected by the presence of tri-N-acetyl-d-glucosamine (triNAG). The folding rate of C64A/C80A was found to be the fastest and almost the same as that of the recombinant hen lysozyme containing the extra N-terminal, and that of C30A/C115A the second, and that of C6S/C127A the third. The folding rate of C76A/C94A was particularly slow. On the other hand, the unfolding rates which were measured in the presence of triNAG showed the dependence on the concentration of triNAG. The intrinsic unfolding rate in the absence of triNAG was determined by extrapolation. Also in the unfolding rate, C76A/C94A was markedly slower than the others. It was found from the analysis of binding constants of triNAG to C64A/C80A during the unfolding process that the active site of C64A/C80A partly unfolds already prior to the unfolding transition. On the basis of these kinetic data, we suggest that C64A/C80A folding transition can occur with leaving the loop region around SS3 (C64-C80) flexible, while cross-linking by SS4 (C76-C94) is important for the promotion of folding, because it is an indispensable constraint on the way towards the folding transition state.


Asunto(s)
Disulfuros/metabolismo , Variación Genética/genética , Muramidasa/química , Muramidasa/metabolismo , Pliegue de Proteína , Sustitución de Aminoácidos/genética , Animales , Sitios de Unión , Calorimetría , Pollos , Dicroismo Circular , Cisteína/genética , Cisteína/metabolismo , Estabilidad de Enzimas , Femenino , Fluorescencia , Guanidina/farmacología , Cinética , Metionina/genética , Metionina/metabolismo , Modelos Moleculares , Muramidasa/genética , Desnaturalización Proteica/efectos de los fármacos , Renaturación de Proteína , Estructura Terciaria de Proteína/efectos de los fármacos , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Termodinámica , Volumetría , Trisacáridos/metabolismo
10.
J Clin Endocrinol Metab ; 54(2): 423-8, 1982 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-6798067

RESUMEN

A solid phase RIA in which an antibody adsorbed onto polystyrene balls was developed to determine PRA. Complete inhibition of converting enzyme and angiotensinase during enzymatic reaction was achieved by phenyl methyl sulfonyl fluoride and EDTA combination. Pepstatin A was found to be an effective agent to block angiotensin I generation during the RIA, and the sample can be directly incubated at room temperature for RIA without any special treatment to inhibit renin activity. The intra- and interassay coefficients of variation (CV) were 5.5-6.9% and 3.7-8.2%, respectively. The recovery was 91.9-117% of added angiotensin I. The assay is sufficiently sensitive and reliable for routine use and correlates acceptably (r = 0.996) with an established RIA. The antibody-adsorbed balls were compared to the soluble antibody with respect to thermodynamic parameters. It was found that the apparent equilibrium constant of the antibody-adsorbed ball was reduced to approximately 1/2 sec of soluble antibody, which was predominately due to the decrease in unitary entropy change by adsorption.


Asunto(s)
Radioinmunoensayo/métodos , Renina/sangre , Angiotensina I/inmunología , Angiotensina I/metabolismo , Ácido Edético , Furosemida , Humanos , Pepstatinas , Fluoruro de Fenilmetilsulfonilo , Poliestirenos , Renina/antagonistas & inhibidores , Termodinámica
11.
DNA Res ; 8(6): 263-9, 2001 Dec 31.
Artículo en Inglés | MEDLINE | ID: mdl-11853314

RESUMEN

The beta-glucosidase gene (bglxA) was cloned from the genomic DNA of Acetobacter xylinum ATCC 23769 and its nucleotide sequence (2200 bp) was determined. This bglxA gene was present downstream of the cellulose synthase operon and coded for a polypeptide of molecular mass 79 kDa. The overexpression of the beta-glucosidase in A. xylinum caused a tenfold increase in activity compared to the wild-type strain. In addition, the action pattern of the enzyme was identified as G3ase activity. The deduced amino acid sequence of the bglxA gene showed 72.3%, 49.6%, and 45.1% identity with the beta-glucosidases from A. xylinum subsp. sucrofermentans, Cellvibrio gilvus, and Mycobacterium tuberculosis, respectively. Based on amino acid sequence similarities, the beta-glucosidase (BglxA) was assigned to family 3 of the glycosyl hydrolases.


Asunto(s)
Genes Bacterianos , Gluconacetobacter xylinus/enzimología , Gluconacetobacter xylinus/genética , beta-Glucosidasa/genética , Secuencia de Aminoácidos , Secuencia de Bases , Clonación Molecular , Datos de Secuencia Molecular , Sistemas de Lectura Abierta , Análisis de Secuencia , Homología de Secuencia de Aminoácido , beta-Glucosidasa/química
12.
DNA Res ; 7(4): 237-42, 2000 Aug 31.
Artículo en Inglés | MEDLINE | ID: mdl-10997873

RESUMEN

The levansucrase gene (lsxA) was cloned from the genomic DNA of Acetobacter xylinum NCI 1005, and the nucleotide sequence of the lsxA gene (1,293 bp) was determined. The deduced amino acid sequence of the lsxA gene showed 57.4% and 46.2% identity with the levansucrases from Zymomonas mobilis and Erwinia amylovora, respectively, while only 35.2% identity with that from Acetobacter diazotrophicus. The gene product of lsxA (LsxA) that was overproduced in E. coli coded for a polypeptide of molecular mass 47 kDa. The LsxA released glucose and produced polysaccharide from sucrose, the structure of which was analyzed by nuclear magnetic resonance spectroscopy and determined to be a beta-(2,6)-linked polyfructan.


Asunto(s)
Gluconacetobacter xylinus/genética , Hexosiltransferasas/genética , Secuencia de Aminoácidos , Secuencia de Bases , Clonación Molecular , Electroforesis en Gel de Poliacrilamida , Erwinia/genética , Escherichia coli/metabolismo , Glucosa/metabolismo , Hexosiltransferasas/química , Hexosiltransferasas/metabolismo , Espectroscopía de Resonancia Magnética , Datos de Secuencia Molecular , Sistemas de Lectura Abierta , Péptidos/química , Polisacáridos/metabolismo , Análisis de Secuencia de ADN , Homología de Secuencia de Aminoácido , Sacarosa/metabolismo , Factores de Tiempo , Zymomonas/genética
13.
FEBS Lett ; 311(1): 12-6, 1992 Oct 12.
Artículo en Inglés | MEDLINE | ID: mdl-1397285

RESUMEN

In the inhibition of specific binding of [125I]endothelins (ETs) to membrane from various tissues of rats, guinea pigs, pigs and humans, [Cys11-Cys15]-ET-1(11-21), IRL 1038, has a much higher affinity for ETB receptors (Ki = 6-11 nM) than for ETA receptors (Ki = 0.4-0.7 microM). In contraction assays, with ET-3 as a stimulant, 3 microM IRL 1038 antagonized the ETB receptor-mediated contraction of guinea pig ileal and tracheal smooth muscle without any significant agonistic activity, but did not effect the ETA receptor-mediated contraction of rat aortic smooth muscle. IRL 1038 is therefore, considered to be the first antagonist selective to the ETB receptor.


Asunto(s)
Antagonistas de los Receptores de Endotelina , Endotelinas/metabolismo , Endotelinas/farmacología , Fragmentos de Péptidos/farmacología , Receptores de Endotelina/metabolismo , Secuencia de Aminoácidos , Animales , Bioensayo , Cistina , Disulfuros , Relación Dosis-Respuesta a Droga , Endotelinas/síntesis química , Cobayas , Humanos , Ligandos , Membranas/metabolismo , Datos de Secuencia Molecular , Contracción Muscular/efectos de los fármacos , Contracción Muscular/fisiología , Músculo Liso/efectos de los fármacos , Músculo Liso/fisiología , Especificidad de Órganos , Fragmentos de Péptidos/síntesis química , Ratas , Sensibilidad y Especificidad , Homología de Secuencia de Aminoácido , Porcinos
14.
Int J Radiat Oncol Biol Phys ; 14(5): 1025-31, 1988 May.
Artículo en Inglés | MEDLINE | ID: mdl-3360646

RESUMEN

An evaluation of the ring scan and the spot scan was made for the pion irradiation of head and neck tumors with the Piotron. For the geometry of the Piotron, with its 60 radially converging beams, two scanning techniques have been developed, ring scan and spot scan. They have different characteristics concerning achievable dose distributions and sensitivity to tissue inhomogenities. The optimized 3-dimensional dose distributions for the treatment with ring scan and spot scan techniques were calculated for two examples of the target volume. The comparison of the dose distributions has shown that the ring scan is better in sparing normal tissues than the spot scan for a simple shape target volume but not for an irregular shape target volume with the present status of the technique. The irradiation time needed for the ring scan is longer, for the present examples three times, than for the spot scan. From the practical view point the spot scan is preferable to the ring scan for the treatment of head and neck tumors with the Piotron.


Asunto(s)
Partículas Elementales/uso terapéutico , Neoplasias de Cabeza y Cuello/radioterapia , Mesones/uso terapéutico , Humanos , Métodos , Dosificación Radioterapéutica
15.
J Med Chem ; 22(11): 1380-4, 1979 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-160461

RESUMEN

Usnic acid, a lichen antibiotic, showed low-level activity in the Lewis lung carcinoma test system. In an effort to produce new agents of potential use in the treatment of lung cancer, derivatives of the natural product were synthesized and evaluated with a cytotoxicity assay. Structure--activity analysis of the cytotoxicity data indicated the importance of the lipophilicity and the beta-triketone moiety of usnic acid on cytotoxicity. No significant increases in survival of test animals over controls were shown by any of the synthetic compounds in the P388 leukemia or the Lewis lung carcinoma test systems.


Asunto(s)
Antineoplásicos/síntesis química , Benzofuranos/síntesis química , Animales , Benzofuranos/análogos & derivados , Benzofuranos/farmacología , Técnicas In Vitro , Leucemia L1210/tratamiento farmacológico , Leucemia P388/tratamiento farmacológico , Neoplasias Pulmonares/tratamiento farmacológico , Ratones , Neoplasias Experimentales/tratamiento farmacológico , Solubilidad , Relación Estructura-Actividad
16.
J Med Chem ; 23(5): 549-53, 1980 May.
Artículo en Inglés | MEDLINE | ID: mdl-7381855

RESUMEN

First isolated in 1953 from a fermentation broth, chartreusin (1) has received renewed interest as a result of substantial antitumor activities recently demonstrated in several murine test systems. Poor water solubility frustrated formulation attempts, and rapid biliary excretion observed in mice made 1 an improbable candidate for clinical development but an excellent candidate for an analogue synthesis program. From a common intermediate, which was prepared from 1, three analogues were synthesized wherein the disaccharide moiety of 1 was systematically replaced with fucose (6), glucose (7), and the disaccharide maltose (8). Each of the three analogues had a cytotoxic potency against cultured L1210 cells which was equal to, or better than, that shown by 1. Based on the structural similarity with the parent, an improved water solubility, and a favorable accessibility through synthesis, maltoside 8 was choe P388 leukemia, 8 showed reproducible activity comparable to chartreusin at similar dose levels. Although 8 caused no observable toxic effects at therapeutic dose levels when given ip, neither 1 nor 8 produced active indications when administered subcutnaeously.


Asunto(s)
Antibióticos Antineoplásicos/síntesis química , Glicósidos/síntesis química , Animales , Benzopiranos , Supervivencia Celular/efectos de los fármacos , Fenómenos Químicos , Química , Glicósidos/farmacología , Leucemia L1210/tratamiento farmacológico , Leucemia P388/tratamiento farmacológico , Ratones , Neoplasias Experimentales/tratamiento farmacológico , Solubilidad
17.
Br J Pharmacol ; 109(2): 486-90, 1993 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-8358547

RESUMEN

1. The effects of a novel and selective agonist at the endothelin ETB receptor, IRL 1620 (Suc-[Glu9, Ala11,15] endothelin-1 (8-21)), were examined in the isolated aorta of the rat. 2. IRL 1620 (1-300 nM) changed neither the resting tone nor the cytosolic Ca2+ level ([Ca2+]i) of the aorta without endothelium. In the presence of endothelium, however, IRL 1620 increased endothelial [Ca2+]i with little effect on the muscle tone. In the absence of external Ca2+, IRL 1620 still induced a transient increase in endothelial [Ca2+]i. 3. Noradrenaline (100 nM) increased both muscle [Ca2+]i and tension. IRL 1620 (1-300 nM) relaxed the muscle with an increase in endothelial [Ca2+]i only in the presence of endothelium. An inhibitor of nitric oxide synthase, 100 microM NG-monomethyl-L-arginine, inhibited the relaxant effect of IRL 1620 but not the increase in endothelial [Ca2+]i. 4. In resting and noradrenaline-stimulated aorta, the effects of IRL 1620 were inhibited by a selective antagonist of the ETB receptor, IRL 1038 (0.3-3 microM), although a selective antagonist of the ETA receptor, BQ-123 (3 microM), was ineffective. Verapamil (10 microM) did not alter the effects of IRL 1620. 5. A muscarinic receptor agonist, carbachol (1 microM), also induced endothelium-dependent relaxation with an increase in endothelial [Ca2+]i. However, the effects of carbachol were not inhibited by the ETB antagonist, IRL 1038 (3 microM). 6. These results suggest that IRL 1620 is a selective agonist at the ETB receptor which increases endothelial [Ca2+]i by releasing Ca2+ from storage sites and by opening non-L type Ca2+ channels,activates nitric oxide synthase, releases nitric oxide, and relaxes vascular smooth muscle.


Asunto(s)
Endotelinas/farmacología , Endotelio Vascular/fisiología , Músculo Liso Vascular/efectos de los fármacos , Fragmentos de Péptidos/farmacología , Receptores de Endotelina/efectos de los fármacos , Animales , Aorta Torácica/efectos de los fármacos , Arginina/análogos & derivados , Arginina/farmacología , Calcio/metabolismo , Carbacol/farmacología , Endotelio Vascular/efectos de los fármacos , Técnicas In Vitro , Masculino , Relajación Muscular/efectos de los fármacos , Norepinefrina/farmacología , Cloruro de Potasio/farmacología , Ratas , Ratas Wistar , Verapamilo/farmacología , omega-N-Metilarginina
18.
J Biochem ; 117(4): 774-9, 1995 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-7592538

RESUMEN

Desiccation by vacuum-drying inactivates the restriction endonuclease HindIII completely. However, when dried in the presence of a disaccharide such as trehalose, maltose, or sucrose, the endonuclease retains its lambda DNA-cleaving activity and produces the same digestive fragments as does the intact enzyme. Thus, the disaccharides are effective in protecting the restriction enzyme in terms of both recognition and accurate cleavage of the substrate. Among the disaccharides, trehalose protects the enzyme most effectively; and it also stabilizes the enzyme during dilution in aqueous solution. The restriction enzyme dried with trehalose maintains its activity without detectable loss for at least 4 days at 37 degrees C, but it shows reduced activity after 30-day storage at either 4 degrees C or room temperature. Trehalose also protects other restriction endonucleases, EcoRI and BamHI, from inactivation during vacuum-drying, whereas drying them alone leads to severe loss of their activity. The restriction endonucleases dried with trehalose retain their activities for at least 20 days at 4 degrees C and for 7 days at room temperature.


Asunto(s)
Enzimas de Restricción del ADN/química , Disacáridos/farmacología , Enzimas de Restricción del ADN/metabolismo , Desoxirribonucleasa BamHI/química , Desoxirribonucleasa BamHI/metabolismo , Desoxirribonucleasa EcoRI/química , Desoxirribonucleasa EcoRI/metabolismo , Desoxirribonucleasa HindIII/química , Desecación , Activación Enzimática/efectos de los fármacos , Estabilidad de Enzimas , Maltosa/farmacología , Sacarosa/farmacología , Temperatura , Factores de Tiempo , Trehalosa/farmacología , Vacio
19.
Eur J Pharmacol ; 231(3): 371-4, 1993 Feb 16.
Artículo en Inglés | MEDLINE | ID: mdl-8449230

RESUMEN

In isolated rat aorta, endothelin-1 induced contractions at lower concentrations than endothelin-3. The contractile effects were augmented by removing the endothelium. In contrast, endothelium-1 and endothelin-3 at similar concentrations induced endothelium-dependent relaxation in norepinephrine-stimulated aorta. IRL 1038 ([Cys11,Cys15]endothelin-1(11-21); 3 microM) augmented the contractile effects of endothelins only in the presence of the endothelium. IRL 1038 (0.3-3 microM) inhibited the endothelium-dependent relaxation induced by endothelins but not by carbachol. IRL 1038 itself did not change muscle tension. These results suggest that IRL 1038 is a novel antagonist of the ETB receptor responsible for the release of relaxing factor from the vascular endothelium.


Asunto(s)
Antagonistas de los Receptores de Endotelina , Endotelinas/farmacología , Músculo Liso Vascular/efectos de los fármacos , Fragmentos de Péptidos/farmacología , Animales , Interacciones Farmacológicas , Endotelio Vascular/efectos de los fármacos , Endotelio Vascular/metabolismo , Masculino , Contracción Muscular/efectos de los fármacos , Relajación Muscular/efectos de los fármacos , Músculo Liso Vascular/metabolismo , Óxido Nítrico/metabolismo , Ratas , Ratas Wistar
20.
Eur J Pharmacol ; 264(3): 399-405, 1994 Nov 03.
Artículo en Inglés | MEDLINE | ID: mdl-7698181

RESUMEN

The effects of a selective agonist for endothelin ETB receptors, Suc-[Glu9,Ala11,15]endothelin-1-(8-21), IRL1620, on renal hemodynamics and urine formation were studied in anesthetized dogs. Intrarenal arterial infusion of IRL1620 at a dose of 50 ng/kg/min increased renal blood flow from 3.37 +/- 0.30 (mean +/- S.E.) to a maximal value of 4.43 +/- 0.45 ml/g kidney weight per min (ml/g/min) at 9.1 +/- 1.0 min after the start of infusion, with no change in systemic blood pressure and heart rate. Urine flow rate increased and urine osmolality, osmolar clearance and free water reabsorption decreased significantly whereas glomerular filtration rate remained unchanged. In dogs given ibuprofen (12.5 mg/kg, i.v.) after the start of infusion of the peptide, renal blood flow increased slightly but significantly from 3.78 +/- 0.82 to 4.17 +/- 0.96 ml/g/min (1.0 +/- 0.1 min), followed by a gradual reduction in renal blood flow. In dogs given L-NG-nitroarginine (75 micrograms/kg/min), the renal blood flow decreased following intrarenal administration of IRL1620 (50 ng/kg/min). It is suggested that IRL1620 enhances the release of nitric oxide and prostaglandins in the kidney and promotes renal vasodilation. The IRL1620-induced reduction of urine osmolality and free water reabsorption was affected by neither ibuprofen nor L-NG-nitroarginine, thereby suggesting that the suppression of urine concentration did not seem to be linked to the enhanced production of nitric oxide or prostaglandins in the kidney.


Asunto(s)
Diuresis/efectos de los fármacos , Endotelinas/farmacología , Riñón/efectos de los fármacos , Fragmentos de Péptidos/farmacología , Receptores de Endotelina/agonistas , Vasodilatación/efectos de los fármacos , Animales , Arginina/administración & dosificación , Arginina/análogos & derivados , Arginina/farmacología , Presión Sanguínea/efectos de los fármacos , Perros , Endotelinas/administración & dosificación , Femenino , Tasa de Filtración Glomerular/efectos de los fármacos , Frecuencia Cardíaca/efectos de los fármacos , Ibuprofeno/administración & dosificación , Ibuprofeno/farmacología , Infusiones Intraarteriales , Inyecciones Intravenosas , Riñón/irrigación sanguínea , Riñón/fisiología , Masculino , Nitroarginina , Concentración Osmolar , Fragmentos de Péptidos/administración & dosificación , Circulación Renal/efectos de los fármacos , Micción/efectos de los fármacos
SELECCIÓN DE REFERENCIAS
Detalles de la búsqueda