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1.
Ultrasound Obstet Gynecol ; 49(2): 246-251, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-27089836

RESUMEN

OBJECTIVE: To investigate whether the transperineal sonographic (TPS) parameters angle of progression (AoP) and midline angle (MLA) can predict the time remaining in the second stage of labor. METHODS: We evaluated prospectively women with a singleton pregnancy in cephalic presentation at term between October 2013 and September 2014. TPS volumes were obtained immediately after confirmation by digital vaginal examination of a fully dilated cervix. AoP and MLA were measured offline by analyzing the ultrasound volumes. Progression of labor was evaluated every hour during the second stage. The associations of AoP and MLA with the interval between TPS assessment and delivery were evaluated using multivariable Cox proportional hazards analyses in nulliparous and parous women separately. RESULTS: A total of 557 women were evaluated. An AoP ≥ 160° (adjusted hazard ratio (aHR), 2.52 (95% CI, 1.98-3.19)) and MLA ≤ 10° (aHR, 1.79 (95% CI, 1.35-2.34)) in nulliparous women and an AoP ≥ 150° (aHR, 1.86 (95% CI, 1.34-2.57)) and MLA ≤ 20° (aHR, 1.69 (95% CI, 1.21-2.34)) in parous women were significantly associated with the remaining time in labor. The positive/negative likelihood ratios of AoP, MLA, clinical station (fetal head descent as observed by digital examination) and clinical rotation (fetal head rotation as observed by digital examination) at these cut-off points were 3.6/0.6, 2.0/0.6, 1.6/0.6 and 1.6/0.8, respectively, in nulliparous women, and 2.4/0.6, 1.3/0.7, 7.6/0.5 and 5.2/0.7, respectively, in parous women. CONCLUSION: TPS assessment of AoP and MLA in the second stage of labor was useful for predicting the time remaining in labor and had higher predictive value than did digital vaginal examination in nulliparous women. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.


Asunto(s)
Segundo Periodo del Trabajo de Parto/fisiología , Perineo/diagnóstico por imagen , Ultrasonografía/métodos , Adolescente , Adulto , Parto Obstétrico , Femenino , Humanos , Embarazo , Factores de Tiempo , Adulto Joven
3.
Andrology ; 7(3): 373-381, 2019 05.
Artículo en Inglés | MEDLINE | ID: mdl-30920782

RESUMEN

BACKGROUND: Sperm DNA integrity is crucial for transmission of genetic information to future generations and DNA damage can occur during chromatin packaging. Chromatin packaging involves the replacement of somatic nucleosomal histones by nuclear proteins called protamines. Protamine 1 (PRM1) is transcribed and translated in spermatids of all mammals; however, protamine 2 (PRM2) is transcribed in low levels in spermatids and it is not yet described in bull mature spermatozoa. OBJECTIVES: The aim of this study was to assess gene and protein expression of PRM2 and corroborate gene and protein expression of PRM1 in bull spermatozoa and testis. MATERIALS AND METHODS: For this purpose, absolute q-RT-PCR was performed to calculate the number of copies of PRM1 and PRM2 mRNAs in bovine epididymal spermatozoa and testicular tissue. Western blot and mass spectrometry were performed to identify PRM1 and PRM2 in samples of bovine epididymal spermatozoa. Samples of bovine testicular tissue were collected to identify PRM1 and PRM2 by immunohistochemistry. RESULTS: We evaluated that the number of PRM1 mRNA copies was about hundred times higher than PRM2 mRNA copies in sperm and testicular samples (p < 0.0001). In addition, we estimated the PRM1: PRM2 ratio based on mRNA number of copies. In spermatozoa, the ratio was 1: 0.014, and in testicle, the ratio was 1: 0.009. We also evaluated the immunolocalization for PRM1 and PRM2 in bovine testis, and both proteins were detected in spermatids. Western blot and mass spectrometry in bovine epididymal spermatozoa confirmed these results. CONCLUSION: Our work identifies, for the first time, PRM2 in bovine epididymal spermatozoa and in testis. Further studies are still needed to understand the role of PRM2 on the chromatin of the spermatozoa and to verify how possible changes in PRM2 levels may influence the bull fertility.


Asunto(s)
Bovinos/metabolismo , Protaminas/metabolismo , Espermatozoides/metabolismo , Testículo/metabolismo , Animales , Núcleo Celular/metabolismo , Epidídimo/citología , Expresión Génica , Masculino , Protaminas/genética , ARN Mensajero/metabolismo
4.
Ann Oncol ; 19(6): 1053-9, 2008 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-18304967

RESUMEN

BACKGROUND: Allelic loss in chromosome 3p is one of the most frequent and earliest genetic events in lung carcinogenesis. We investigated if the loss of microRNA-128b, a microRNA located on chromosome 3p and a putative regulator of epidermal growth factor receptor (EGFR), correlated with response to targeted EGFR inhibition. Loss of microRNA-128b would be equivalent to losing a tumor suppressor gene because it would allow increased expression of EGFR. PATIENTS AND METHODS: We initially showed that microRNA-128b is a regulator of EGFR in non-small-cell lung cancer (NSCLC) cell lines. We tested microRNA-128b expression levels by quantitative RT-PCR, genomic copy number by quantitative PCR, and mutations in the mature microRNA-128b by sequencing. We determined whether microRNA-128b loss of heterozygosity (LOH) in 58 NSCLC patient samples correlated with response to gefitinib and evaluated EGFR expression and mutation status. RESULTS: We determined that microRNA-128b directly regulates EGFR. MicroRNA-128b LOH was frequent in tumor samples and correlated significantly with clinical response and survival following gefitinib. EGFR expression and mutation status did not correlate with survival outcome. CONCLUSION: Identifying microRNA regulators of oncogenes could have far-reaching implications for lung cancer patients including improving patient selection for targeted agents, development of novel therapeutics, or development as early biomarkers of disease.


Asunto(s)
Antineoplásicos/uso terapéutico , Carcinoma de Pulmón de Células no Pequeñas/genética , Genes erbB-1/genética , Neoplasias Pulmonares/genética , Quinazolinas/uso terapéutico , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Carcinoma de Pulmón de Células no Pequeñas/mortalidad , Línea Celular Tumoral , Gefitinib , Expresión Génica , Humanos , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/mortalidad , MicroARNs , Análisis de Supervivencia
5.
Curr Biol ; 6(9): 1181-4, 1996 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-8805365

RESUMEN

In human cells, mismatch recognition is mediated by a heterodimeric complex, hMutSalpha, comprised of two members of the MutS homolog (MSH) family of proteins, hMSH2 and GTBP [1,2]. Correspondingly, tumour-derived cell lines defective in hMSH2 and GTBP have a mutator phenotype [3,4], and extracts prepared from these cells lack mismatch-binding activity [1]. However, although hMSH2 mutant cell lines showed considerable microsatellite instability in tracts of mononucleotide and dinucleotide repeats [4,5], only mononucleotide repeats were somewhat unstable in GTBP mutants [4,6]. These findings, together with data showing that extracts of cells lacking GTBP are partially proficient in the repair of two-nucleotide loops [2], suggested that loop repair can be GTBP-independent. We show here that hMSH2 can also heterodimerize with a third human MSH family member, hMSH3, and that this complex, hMutSbeta, binds loops of one to four extrahelical bases. Our data further suggest that hMSH3 and GTBP are redundant in loop repair, and help explain why only mutations in hMSH2, and not in GTBP or hMSH3, segregate with hereditary non-polyposis colorectal cancer (HNPCC) [7].


Asunto(s)
Proteínas de Unión al ADN/metabolismo , ADN/metabolismo , Proteínas Fúngicas , Proteínas Asociadas a Resistencia a Múltiples Medicamentos , Proteínas/genética , Secuencia de Bases , Sitios de Unión , Biopolímeros , Proteínas de Unión al ADN/genética , Humanos , Datos de Secuencia Molecular , Proteína 2 Homóloga a MutS , Proteína 3 Homóloga de MutS , Mutagénesis Insercional , Unión Proteica , Proteínas/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Eliminación de Secuencia
6.
Immunobiology ; 222(11): 1004-1013, 2017 11.
Artículo en Inglés | MEDLINE | ID: mdl-28641918

RESUMEN

Leptospirosis is globally widespread neglected disease, affecting most mammalian species. Clinical signs can be confused with other diseases which make the diagnosis and treatment difficult. Chemokines and cytokines are known for their role in the inflammatory and immune response to infections. The profile determination of chemokines' expressions in the course of infection may elucidate the defense mechanisms of the host and support the search for effective treatment strategies. We investigated the mechanisms of innate immunity through the comparison of chemokines induced during infection with L. interrogans in mice with different levels of susceptibility. We used lung and spleen tissues samples of mice from C3H/HeJ, C3H/HePas and Balb/c, respectively sensitive, intermediate susceptibility and resistant to the pathogen. The inoculation of L. interrogans in C3H/HeJ mice led a comparatively smaller change in chemokines expression in both spleen and lung tissues. In samples from spleens and lungs of C3H/HePas and Balb/c the higher increases occurred on CXCL9, CXCL16, CXCL5, CCL8 and CCL5 in Balb/c. Given the same genetic background, the differences in the responses of C3H/HePas compared to C3H/HeJ mice strongly suggest the role of chemokines for the survival of parental strain. Therefore, the greatest increase in CXC chemokines appears to be efficient to induce migration of cells to the secondary lymphoid organs and affected tissues, which is important to control infection. Overall, CXC chemokines are important for the activation and attraction of T cell and may influence the course and control of the infection in resistant Balb/c mice.


Asunto(s)
Quimiocinas/metabolismo , Leptospira/inmunología , Leptospirosis/patología , Pulmón/fisiología , Animales , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Células Cultivadas , Progresión de la Enfermedad , Regulación Bacteriana de la Expresión Génica , Proteínas Hemolisinas/genética , Proteínas Hemolisinas/metabolismo , Interacciones Huésped-Patógeno , Inmunidad Innata , Mediadores de Inflamación/metabolismo , Leptospirosis/inmunología , Pulmón/microbiología , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C3H , Proteínas de Microfilamentos/genética , Proteínas de Microfilamentos/metabolismo , Receptor Toll-Like 4/metabolismo
7.
Neuroscience ; 141(4): 2139-45, 2006 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-16843603

RESUMEN

BACKGROUND: Our recent study suggested involvement of calpain-induced proteolysis in retinal degeneration and dysfunction in acute ocular hypertensive rats. The purpose of the present study was to determine if an orally available form of calpain inhibitor, ((1S)-1-((((1S)-1-benzyl-3-cyclopropylamino-2,3-di-oxopropyl)amino)carbonyl)-3-methylbutyl)carbamic acid 5-methoxy-3-oxapentyl ester (SNJ-1945), ameliorated retinal degeneration induced by acute hypertension in rats. To help extrapolate the effect of SNJ-1945 from the rat model to the human glaucomatous patient, in vitro inhibition of calpain-induced proteolysis by SNJ-1945 in monkey and human retinal proteins was compared with proteolysis in rat proteins. METHODS: Intraocular pressure (IOP) in rats was elevated to 110 mm Hg for 50 min. SNJ-1945 was administrated i.p. or orally before ocular hypertension. Retinal degeneration was evaluated by hematoxylin and eosin (H&E) staining and cell counting. Transcripts for calpains and calpastatin in rat, monkey, and human retinas were measured by quantitative RT-PCR. Calpain activities were determined by casein zymography. Soluble retinal proteins from rat, monkey, and humans were incubated with calcium to activate calpains, with or without SNJ-1945. Proteolysis of calpain substrate alpha-spectrin was analyzed by immunoblotting. RESULTS: Elevated IOP caused retinal degeneration and proteolysis of alpha-spectrin. Both i.p. and oral administration of SNJ-1945 inhibited proteolysis of alpha-spectrin and ameliorated retinal degeneration. Transcript levels for calpain 1 and calpastatin were similar in rat, monkey, and human retinas. Calpain 2 transcript levels were higher in rats compared with monkey and human. Appreciable caseinolytic activities due to calpains were observed in monkey and human retinas. Incubation of retinal soluble proteins with calcium led to proteolysis of alpha-spectrin due to calpains in rat, monkey, and human samples. SNJ-1945 similarly inhibited proteolysis in all species. CONCLUSION: Our results suggested that orally available calpain inhibitor SNJ-1945 might be a possible candidate drug for testing in preventing progression of glaucomatous retinal degeneration.


Asunto(s)
Glicoproteínas/administración & dosificación , Hipertensión Ocular , Degeneración Retiniana/tratamiento farmacológico , Animales , Proteínas de Unión al Calcio/genética , Proteínas de Unión al Calcio/metabolismo , Calpaína/genética , Calpaína/metabolismo , Carbamatos/administración & dosificación , Modelos Animales de Enfermedad , Vías de Administración de Medicamentos , Haplorrinos , Humanos , Presión Intraocular/efectos de los fármacos , Hipertensión Ocular/complicaciones , Hipertensión Ocular/tratamiento farmacológico , Hipertensión Ocular/metabolismo , ARN Mensajero/metabolismo , Ratas , Ratas Sprague-Dawley , Degeneración Retiniana/etiología , Degeneración Retiniana/patología , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/métodos , Coloración y Etiquetado/métodos , Factores de Tiempo
8.
Cancer Res ; 58(4): 594-8, 1998 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-9485005

RESUMEN

Defects in mismatch repair function can lead to the microsatellite instability (MI+; replication error) phenotype in certain human cancers. We previously reported that MI+ tumor-specific repeat number alteration at 13 consecutive trinucleotide (CAG) repeats within a coding exon of the E2F4 gene is a possible target of the defective repair pathway. Additional investigations revealed that E2F4 mutations are common (11 of 17 cases, 65%, mostly deletions) in a subset of human colorectal cancers with extensive MI+ phenotype, with respect to the proportion of loci affected and that most of these E2F4-mutated tumors (9 of 11, 82%) were accompanied by frameshift mutations in a polyadenine stretch within the seventh exon of the hMSH3 gene, a known mismatch repair gene that is responsible for repair of mismatch loops of two to four nucleotides. However, neither of these mutations was detected in 15 tumors with a lower incidence of MI+ loci. Similar repeat number alterations were less frequent in CAG repeats from other genes in all of the MI+ tumors we examined. These results indicate the presence of a novel cascade of mutational events that may be involved in acquisition of the malignant phenotype of human colorectal cancers with genetic instability.


Asunto(s)
Neoplasias Colorrectales/genética , Proteínas de Unión al ADN/genética , Repeticiones de Microsatélite , Mutación , Factores de Transcripción/genética , Reparación del ADN , Mutación del Sistema de Lectura , Humanos , Células Tumorales Cultivadas
9.
FEBS Lett ; 453(1-2): 85-9, 1999 Jun 18.
Artículo en Inglés | MEDLINE | ID: mdl-10403381

RESUMEN

In eukaryotes, mismatch recognition is thought to be mediated by two heterodimers, hMutSalpha (hMSH2+hMSH6), which preferentially binds to base-base mismatches and hMutSbeta (hMSH2+hMSH3), which binds to insertion/deletion loops. We studied these mismatch binding activities in several human cell lines with a gel-shift assay using various mismatch oligonucleotides as substrates. Both hMutSalpha and hMutSbeta activities could be detected in various human cell lines. In cells with amplified copies of the hMSH3 gene, a large increase in hMutSbeta and a reduction in hMutSalpha were observed. To identify the composition of each mismatch binding complex, the protein-DNA complexes were transferred from gel-shift polyacrylamide gel to a polyvinylidene difluoride membrane and were subjected to immunoblot analysis with an enhanced chemiluminescence protein detection system. The results clearly demonstrated that hMutSalpha detected by the gel-shift assay was composed of hMSH2 and hMSH6, while hMutSbeta was composed of hMSH2 and hMSH3. Our data, therefore, support a model whereby formation of hMutSalpha and hMutSbeta is mutually regulated. Combination of a gel-shift assay with immunoblotting (shift-Western assay) proved to be a highly sensitive technique and should be useful for studying the interactions between DNA and binding proteins, including DNA mismatch recognition.


Asunto(s)
Disparidad de Par Base , Reparación del ADN , Proteínas de Unión al ADN/aislamiento & purificación , Proteínas de Neoplasias/aislamiento & purificación , Sistema Libre de Células , Resistencia a Medicamentos , Humanos , Metotrexato/farmacología , Proteínas Nucleares/aislamiento & purificación , Unión Proteica , Células Tumorales Cultivadas
10.
Int J Oncol ; 18(1): 105-10, 2001 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-11115545

RESUMEN

K-ras mutation in sputum was examined using mutant-allele-specific amplification method among 100 primary lung cancer and 15 non-oncological patients. K-ras mutation was detected in 11 out of 59 adenocarcinoma cases (18.6%), 5 out of 32 squamous cell carcinoma cases (15.6%), 2 out of 4 large cell carcinoma cases (50.0%) and 3 out of 15 non-oncological disease cases (20.0%). In the 18 cases of primary lung cancer K-ras mutation was examined in both sputum and the resected specimen of the primary lesion. In 5 cases K-ras mutation in sputum was detected without K-ras mutation in primary lesion. Therefore, these findings suggested that K-ras mutation in sputum may not be directly related to that of the primary lesion.


Asunto(s)
Genes ras , Pruebas Genéticas , Neoplasias Pulmonares/genética , Mutación , Esputo/química , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/patología , Masculino , Persona de Mediana Edad , Pronóstico , Esputo/fisiología
11.
Toxicol Lett ; 15(2-3): 175-9, 1983 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-6829042

RESUMEN

The distribution of mercury in the brain of mice after i.v. administration of methylmercury, methylmercury with selenite, or bis(methylmercuric) selenide (BMS) was examined by whole-body autoradiography using 203Hg-labelled mercury compounds. The radioactivity in the brain of the mice that received methylmercury and selenite simultaneously, or BMS, was higher than that of the mice that received methylmercury alone, but the differences were not significant.


Asunto(s)
Encéfalo/metabolismo , Mercurio/metabolismo , Compuestos de Metilmercurio/metabolismo , Animales , Autorradiografía , Inyecciones Intravenosas , Masculino , Ratones , Ratones Endogámicos ICR , Ácido Selenioso , Selenio/farmacología
12.
J Pharm Sci ; 69(12): 1374-8, 1980 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-7463319

RESUMEN

The relationship between the dose of levodopa and its pharmacokinetic behavior following intravenous and oral administration was investigated in dogs and parkinsonian patients. Six beagle dogs received single doses of 2.4, 4.8, and 9.6 mg of levodopa/kg iv and single doses of 4.8, 9.6, and 19.2 mg of levodopa/kg po in a crossover fashion on separate occasions. Three parkinsonian patients received single oral doses of approximately 3.8, 7.7, and 15.4 mg of levodopa/kg in a crossover test. Plasma samples were analyzed for intact levodopa and total dopamine. The relationship between the area under the plasma concentration-time curve (AUC) of levodopa and the intravenous dose to dogs was linear. However, in both dogs and patients, the relationship after oral dosing was nonlinear, with the relative AUC increasing with increasing dose. Therefore, the pharmacokinetic behavior of levodopa after oral administration to dogs and patients was dose dependent.


Asunto(s)
Levodopa/administración & dosificación , Enfermedad de Parkinson/metabolismo , Administración Oral , Adulto , Animales , Disponibilidad Biológica , Perros , Relación Dosis-Respuesta a Droga , Humanos , Inyecciones Intravenosas , Cinética , Levodopa/metabolismo , Masculino , Persona de Mediana Edad
13.
J Pharm Sci ; 69(3): 261-5, 1980 May.
Artículo en Inglés | MEDLINE | ID: mdl-7381698

RESUMEN

To estimate the absolute bioavailability of oral levodopa, plasma concentrations and urinary excretion of levodopa and its metabolites were determined in beagle dogs and in parkinsonian patients after intravenous and oral drug administration. The absolute bioavailability of orally administered levodopa was estimated to be about 35% in both dogs and patients; however, the total amount absorbed of intact drug and levodopa metabolites was estimated to be 80--90% of the administered dose. Due to the similarities of the pharmacokinetic characteristics of levodopa found in beagle dogs and in humans, beagle dogs can serve as a model to study bioavailability, absorption, and metabolic mechanisms.


Asunto(s)
Levodopa/administración & dosificación , Enfermedad de Parkinson/metabolismo , Administración Oral , Anciano , Animales , Disponibilidad Biológica , Perros , Femenino , Humanos , Inyecciones Intravenosas , Cinética , Levodopa/sangre , Levodopa/metabolismo , Masculino , Persona de Mediana Edad , Especificidad de la Especie
14.
J Pharm Sci ; 70(10): 1157-60, 1981 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-7299652

RESUMEN

Plasma levels of levodopa, total dopamine, and residual amounts of levodopa and its metabolites at the administered site were analyzed following administration of single 100-mg doses of levodopa in solution into isolated segments of the duodenum, jejunum, and ileum of the dog. The largest area under the plasma concentration-time curve (AUC) of levodopa during the 1.0-hr study was obtained following administration in the duodenum, followed by the jejunum and ileum. In addition, the residual amounts of levodopa and its metabolites detected at the administration sites were: ileum, 23%; jejunum, 7% and duodenum, less than 1%. The largest AUC of total dopamine was obtained following administration in the jejunum, followed by the ileum and duodenum. This order was consistent with the order of levodopa decarboxylase enzyme activity reported previously. Therefore, it can be concluded that the major absorption site of levodopa in the intestine resides in the upper small intestine. Levodopa in 10-, 50-, and 100-mg doses was administered into isolated duodenal segments. The AUC of levodopa increased nonlinearly with increasing dose. Negligible amounts of both levodopa and its metabolites were observed in the segment at 1.0 hr after administration, indicating that the duodenal absorption of levodopa was not saturable within the dose range tested.


Asunto(s)
Levodopa/administración & dosificación , Animales , Disponibilidad Biológica , Perros , Dopamina/metabolismo , Duodeno/metabolismo , Absorción Intestinal , Levodopa/metabolismo , Masculino , Factores de Tiempo
15.
J Pharm Sci ; 73(7): 942-6, 1984 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-6088756

RESUMEN

A new dosage form of levodopa, which has the characteristics of loading high concentrations of levodopa at the upper part of the intestine, has been developed to improve its bioavailability. It is shown that an effervescent tablet formulation, coated with hydroxypropyl methylcellulose phthalate (carboxybenzoyl radical content: 20-24%) as the enteric material, is suitable for the purpose of dissolution. This was confirmed from animal experiments, which showed that tablets of this composition disintegrate instantly on reaching the upper part of the intestine. This tablet was considered appropriate for the bioavailability tests described in this paper.


Asunto(s)
Levodopa/administración & dosificación , Animales , Bicarbonatos , Disponibilidad Biológica , Perros , Concentración de Iones de Hidrógeno , Absorción Intestinal , Cinética , Levodopa/metabolismo , Masculino , Bicarbonato de Sodio , Solubilidad , Comprimidos Recubiertos
16.
J Pharm Sci ; 70(7): 730-3, 1981 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-7264915

RESUMEN

Several potential mechanisms for reduced levodopa bioavailability following oral administration to dogs and humans were investigated by studying the influence of the administration route on plasma levodopa levels after intravenous, hepatoportal, and duodenal administrations to dogs. The observed average areas under the plasma concentration-time curves (AUC) of levodopa following hepatoportal injection and intravenous injection were virtually identical; but following duodenal administration a decrease in the AUC of levodopa was observed with a concomitant increase in the AUC of total dopamine. The possible involvement of intestinal microorganisms in levodopa metabolism was explored in dogs that had been administered a combination of paromomycin and kanamycin to reduce intestinal microflora. Similar patterns of plasma level profiles and urinary excretion were observed between control and treated dogs. As measured by the release of [14C]carbon dioxide from [14C]levodopa, the distribution of levodopa decarboxylase enzyme activity in various parts of the intestine was studied in homogenates prepared from isolated intestinal segments of the duodenum and upper, middle, and lower parts of the jejunum and ileum. The jejunum showed the highest decarboxylase activity followed by the ileum and duodenum. These data indicate that the reduced bioavailability of orally administered levodopa occurs as a result of metabolism by levodopa decarboxylase enzyme in the gut wall.


Asunto(s)
Levodopa/administración & dosificación , Administración Oral , Animales , Disponibilidad Biológica , Biotransformación , Sistema Digestivo/microbiología , Perros , Dopa-Decarboxilasa/metabolismo , Absorción Intestinal , Intestinos/enzimología , Cinética , Levodopa/metabolismo , Masculino
17.
Mutat Res ; 278(2-3): 193-5, 1992.
Artículo en Inglés | MEDLINE | ID: mdl-1372705

RESUMEN

A micronucleus test was conducted on the peripheral blood of mice and rats utilizing acridine orange-coated slides (AO-coated method) after oral administration of benzene. Blood was sampled at 0, 24, 48, and 72 h after administration of benzene at doses of 500, 1000, and 2000 mg/kg in both mice and rats. The highest occurrence of micronucleated reticulocytes (MNRETs) was observed at 48 h after administration in both species. Species differences was found in the frequency of MNRETs, with the number being lower in rats than in mice. The present results indicate that the micronucleus test can easily detect chromosome aberrations in peripheral blood induced by benzene administration in both mice and rats. Furthermore, the AO-coated method used in this study was simpler to perform and allowed for easier detection of the effect than the conventional method.


Asunto(s)
Benceno/toxicidad , Mutágenos/toxicidad , Reticulocitos/efectos de los fármacos , Naranja de Acridina , Animales , Relación Dosis-Respuesta a Droga , Masculino , Ratones , Ratones Endogámicos , Pruebas de Micronúcleos/métodos , Mitomicina/toxicidad , Ratas , Ratas Endogámicas , Especificidad de la Especie
18.
Mutat Res ; 382(3-4): 115-20, 1998 May.
Artículo en Inglés | MEDLINE | ID: mdl-9691992

RESUMEN

Microsatellite instability of DNA samples of 79 sporadic colon cancer patients were analyzed. These samples were also screened to search mutations in the repeat sequences in the gene for the type II receptor of transforming growth factor-beta (TGF-beta RII) using polymerase chain reaction (PCR), electrophoresis with urea gel, and PCR-single strand conformation polymorphism (PCR-SSCP) method. The incidence of microsatellite instability, defined as severe replication error phenotype (RER) with microsatellite alterations in more than three loci, was 6%. Deletion and insertion of an A residue in the (A)10 region, which cause frameshift mutation, were found in four samples and their incidence in the samples with microsatellite instability was 80%. A novel nucleotide substitution of T for G at 1918, which causes missense mutation of arginine to leucine at codon 528, was found in a sample with microsatellite instability. The mutation at 1918 was in highly conservative amino acid residue.


Asunto(s)
Neoplasias del Colon/genética , ADN de Neoplasias/genética , Mutación del Sistema de Lectura , Repeticiones de Microsatélite , Proteínas de Neoplasias/genética , Receptores de Factores de Crecimiento Transformadores beta/genética , Replicación del ADN , Humanos , Reacción en Cadena de la Polimerasa , Polimorfismo Conformacional Retorcido-Simple , Proteínas Serina-Treonina Quinasas , Receptor Tipo II de Factor de Crecimiento Transformador beta
19.
Curr Eye Res ; 29(4-5): 337-47, 2004.
Artículo en Inglés | MEDLINE | ID: mdl-15590481

RESUMEN

PURPOSE: The purpose of the current experiments was to more closely define the distribution and the function of calpain small subunit 2 (css2). Css2 is a newly discovered regulatory protein for the calcium activated proteases, mu- and m-calpains. METHODS: Tissues from rat, monkey, and man of various ages were used to determine expression patterns of css2 by relative quantitative RT-PCR using 18S rRNA as an endogenous standard. Recombinant css2 and the 80 kDa catalytic subunit of m-calpain (80 kDa/css2) were co-expressed in Escherichia coli. Casein zymography was used to measure the enzymatic activity of 80 kDa/css2 proteins. Lens alpha-crystallin and beta B1-crystallin were used as substrates to determine proteolysis by 80 kDa/css2. Computer-based homology modeling was used to predict interactions between the traditional small subunit (css1) or css2 with the 80 kDa catalytic subunit. RESULTS: Css2 appears to be a functional equivalent of css1 in vitro in that the calcium-dependent proteolytic activity of 80 kDa/css2 was similar to recombinant m-calpain (80 kDa/css1). In rat and human lens, css2 transcripts increased with age, whereas css1 transcripts decreased with age. Human beta B1-crystallin and rat alpha A-crystallin were cleaved similarly by 80 kDa/css2 and 80 kDa/css1. Interestingly, alpha A-insert crystallin was not hydrolyzed when css2 was substituted for css1 in the calpain dimer, suggesting that css2 may perform different functions from css1 in terms of proteolysis of lens crystallins during maturational growth of the lens. Css2 may also assist in the proper folding of the 80 kDa subunit and regulate protease activity in the absence of calcium. CONCLUSIONS: The wide distribution of css2 transcripts in rat and monkey suggested that css2 is a second, widely distributed (rather than tissue-specific) calpain small subunit, in addition to the long-recognized css1. Further studies at the protein level will indicate if css2 has unique functions apart from css1.


Asunto(s)
Calpaína/genética , Regulación Enzimológica de la Expresión Génica/fisiología , Cristalino/enzimología , Adolescente , Adulto , Anciano , Envejecimiento/fisiología , Animales , Proteínas de Unión al Calcio/farmacología , Niño , Preescolar , Cristalinas/metabolismo , Escherichia coli/enzimología , Humanos , Lactante , Macaca mulatta , Masculino , Persona de Mediana Edad , Chaperonas Moleculares/metabolismo , ARN Mensajero/metabolismo , Ratas , Ratas Sprague-Dawley , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Distribución Tisular , Transfección
20.
Surg Neurol ; 40(3): 183-95, 1993 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-8346472

RESUMEN

The pharmacokinetics of 1-(4-amino-2-methyl-5-pyrimidinyl) methyl-3-(2-chloroethyl)-3-nitrosourea (ACNU) in the cerebrospinal fluid (CSF), were determined in dogs after ventriculolumbar perfusion (VLP, n = 6), and bolus injection into the ventricle (VB, n = 2), cisterna magna (MB, n = 5), and lumbar cistern (LB, n = 3), by high-performance liquid chromatography. The VLP method introduced effective amounts of ACNU into the lumbar cistern for cell kill in vitro. That is, the areas under the time concentration curve (AUC) of ACNU in the lumbar CSF for those receiving a 1.5 mg perfusion of ACNU were 481, 791, and 520 micrograms.min/ml and those receiving a 5 mg perfusion were 1,081, 2,048, and 1,215 micrograms.min/ml, respectively. These values were superior to 3-log cell kill condition of 9L gliosarcoma and 1.5-log cell kill of HU-126 human glioma cell line. Among the groups to which 5 mg of ACNU was administered, the VLP method attained significantly higher AUC values in the lumbar CSF than MB method. Quantitative autoradiography using an imaging plate system was performed in the VLP group (n = 2), VB group (n = 1), MB group (n = 2), and LB group (n = 2) using a 10 microCi/kg [ethylene-14C] ACNU dose which is thought to be related to the alkylating activity of ACNU. The VLP method attained a stable and abundant distribution of ACNU in the neural axis from the ventricular cavity to the lumbar cistern, but the cerebral convexity surface was devoid of a significant level of ACNU. When the MB method was used, the pharmacokinetic data varied in the cisterna magna and lumbar region, and again no significant level of ACNU was detected in the ventricular cavity. With the LB method, although a rich distribution was detected in the spinal cord, the concentration decreased abruptly at the upper cervical level. The VB method was unsatisfactory for obtaining an effective amount of ACNU in the lumbar region. The research and testing to date indicate that the VLP method is the procedure of choice in the treatment of meningeal dissemination.


Asunto(s)
Nimustina/farmacocinética , Animales , Autorradiografía , Cromatografía Líquida de Alta Presión , Perros , Inyecciones Espinales , Nimustina/administración & dosificación , Perfusión
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