Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 86
Filtrar
1.
Zhonghua Yi Xue Za Zhi ; 103(34): 2720-2726, 2023 Sep 12.
Artigo em Zh | MEDLINE | ID: mdl-37675544

RESUMO

Objective: To study the effect of unexpected follicular development in artificial cycles on the clinical outcomes in frozen thawed embryo transfer based on propensity score matching(PSM). Methods: The retrospective cohort study analyzed the clinical data of 7 064 cycles (5 716 patients) of artificial cycle frozen-thawed embryo transfer (AC-FET) in the Reproduction Center of the Third Affiliated Hospital of Zhengzhou University from January 1, 2016 to December 31, 2020. The clinical data were divided into three groups according to the degree of follicular development in AC-FET: no follicular growth group (group A, 6 349 cycles), small follicular growth group (group B, 248 cycles), and large follicular growth group (group C, 467 cycles). Differences in clinical outcomes between the small follicle growth group (Group B) and the large follicle growth group (Group C) were compared with the no follicle growth group (Group A) after PSM and logistic regression to adjust for confounding factors at baseline. A binary logistic regression model was used to analyze the factors related to the unanticipated follicular development in AC-FET. Results: Age [M(Q1,Q3)] was [31.0 (28.0, 36.0)] years in Group A, [34.5 (30.0, 40.0)] years in Group B, and [36.0 (31.0, 41.0)] years in Group C. After adjusting for confounders, the differences between Groups A and B in clinical pregnancy rate (P=0.169), live birth rate (P=0.318), early abortion rate (P=0.470), and miscarriage rate (P=0.783) were not statistically significant. The differences in clinical pregnancy rate (P=0.743), live birth rate (P=0.486) and miscarriage rate (P=0.080) between Groups A and C were not statistically significant, while early miscarriage rate (P=0.034) differences were statistically significant. The age, BMI, basal AFC, AMH and starting dose of estrogen were correlates of the emergence of non-expected small follicles in Groups B and A. The adjusted OR (AOR) values (95%CI) were 1.03 (1.01-1.06), 0.93 (0.90-0.98), 0.97 (0.95-0.99), 0.96 (0.95-0.97), and 0.59 (0.45-0.77), all P<0.05. Age, basal AFC, AMH and starting dose of estrogen were the associated factors of the appearance of non-expected large follicles in Groups C and A. The AOR values (95%CI) were 1.03 (1.01-1.05), 0.93 (0.91-0.95), 0.96 (0.95-0.97), and 0.52 (0.42-0.64), all P<0.05. Conclusions: In AC-FET, the clinical outcome of small follicular growth is similar to that of unfollicular growth; Compared with the growth without follicles, the growth and development of large follicles can reduce the early abortion rate; Patients with older age, less AFC, lower AMH, and lower initial dose of estrogen could be more likely to have unanticipated follicular development during endometrial preparation.


Assuntos
Aborto Espontâneo , Feminino , Gravidez , Humanos , Pontuação de Propensão , Estudos Retrospectivos , Transferência Embrionária , Estrogênios
2.
Zhonghua Yi Xue Za Zhi ; 97(22): 1714-1718, 2017 Jun 13.
Artigo em Zh | MEDLINE | ID: mdl-28606280

RESUMO

Objective: To explore the role of the segmental lymph node dissection in the pathologic staging of non-small cell lung cancer. Methods: A total of 370 consecutive non-small cell lung cancer patients who underwent radical resection between August 2008 and July 2016 were retrospectively reviewed. All the operations were performed by the same group of surgeons. The relationship of the segmental lymph nodes with pathological stages after radical resection was analyzed in order to explore the role of the lymph node dissection in the pathologic staging of non-small cell lung cancer (using the 7th edition of the American Joint Committee on Cancer and Union for International Cancer Control TNM classification for lung cancer ). Results: The detection rates of hilar nodes, interlobar nodes, lobar nodes and segmental nodes were 69.7%, 86.8%, 84.0%, 67.0%, respectively. The metastasis rates of hilar nodes, interlobar nodes, lobar nodes and segmental nodes were 6.5%, 10.8%, 15.7% and 10.3%, respectively. There were 238 cases of N0 disease, 62 cases of N1 disease, 69 cases of N2 disease and 1 case of N3 disease. If the analysis of segmental lymph nodes had been omitted, 16 patients (25.8% of N1 disease) would have been down-staged to N0, and 5 cases of multiple-station N1 disease would have been misdiagnosed as single-station N1 disease, 2 patients would have been misdiagnosed as N2 disease with skip metastases. Conclusion: Segmental nodes play an important role in the accurate staging of non-small cell lung cancer.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/diagnóstico , Neoplasias Pulmonares/diagnóstico , Metástase Linfática , Estadiamento de Neoplasias , Carcinoma Pulmonar de Células não Pequenas/patologia , Humanos , Neoplasias Pulmonares/patologia , Excisão de Linfonodo , Linfonodos , Prognóstico , Estudos Retrospectivos
3.
Curr Drug Targets ; 23(8): 818-835, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34636297

RESUMO

Coronaviruses have been receiving continuous attention worldwide as they have caused a serious threat to global public health. This group of viruses is named so as they exhibit characteristic crown-like spikes on their protein coat. SARS-CoV-2, a type of coronavirus that emerged in 2019, causes severe infection in the lower respiratory tract of humans and is often fatal in immunocompromised individuals. No medications have been approved so far for the direct treatment of SARS-CoV-2 infection, and the currently available treatment options rely on relieving the symptoms. The medicinal plants occurring in nature serve as a rich source of active ingredients that could be utilized for developing pharmacopeial and non-pharmacopeial/synthetic drugs with antiviral properties. Compounds obtained from certain plants have been used for directly and selectively inhibiting different coronaviruses, including SARS-CoV, MERS-CoV, and SARS-CoV-2. The present review discusses the potential natural inhibitors against the highly pathogenic human coronaviruses, with a systematic elaboration on the possible mechanisms of action of these natural compounds while acting in the different stages of the life cycle of coronaviruses. Moreover, through a comprehensive exploration of the existing literature in this regard, the importance of such compounds in the research and development of effective and safe antiviral agents is discussed. We focused on the mechanism of action of several natural compounds along with their target of action. In addition, the immunomodulatory effects of these active components in the context of human health are elucidated. Finally, it is suggested that the use of traditional medicinal plants is a novel and feasible remedial strategy against human coronaviruses.


Assuntos
Tratamento Farmacológico da COVID-19 , Coronavírus da Síndrome Respiratória do Oriente Médio , Antivirais/farmacologia , Antivirais/uso terapêutico , Humanos , SARS-CoV-2
6.
J Viral Hepat ; 16(1): 45-52, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18761606

RESUMO

The type I interferon (IFN-alpha/beta) receptor 1 (IFNAR1) mediates the potent antiviral and immuno-regulatory effects of IFN-alpha/beta that are believed to be pivotal to eradicate hepatitis B virus (HBV) infection. IFNAR1 promoter polymorphisms (at -568/-77) have been shown to be associated with susceptibility to chronic HBV infection; however, whether these markers are genetic determinants of HBV infection remains unknown. The functional significance of promoter -568/-77 polymorphisms was assessed by mutagenesis and luciferase assays. Sequencing and restriction fragment length polymorphisms in 328 chronic HBV patients, 130 spontaneous resolvers and 148 healthy blood donors identified other polymorphism at IFNAR1 open reading frame. IFNAR1 expression levels in peripheral blood cells were detected by flow cytometry. We found that the -568/-77 promoter variants were unlikely to affect transcription levels. A C/G single nucleotide polymorphism, in strong linkage disequilibrium with the promoter polymorphisms, was found in the coding sequence of IFNAR1 (nt19158). This resulted in a nonsynonymous substitution in the extracellular region of IFNAR1 protein and correlated with susceptibility to chronic HBV infection. Bioinformatic analysis suggested decreased stability of the IFNAR1 protein. Chronic HBV patients with the 19158C/C genotype (Leu141) exhibited higher IFNAR1 protein expression levels in peripheral blood monocytes than those with the 19158G/G genotype (Val141). In conclusion, IFNAR1 19158C/G polymorphism is primarily associated with susceptibility to chronic HBV infection.


Assuntos
Suscetibilidade a Doenças , Hepatite B Crônica/genética , Polimorfismo de Nucleotídeo Único , Receptor de Interferon alfa e beta/genética , Substituição de Aminoácidos/genética , Feminino , Citometria de Fluxo , Perfilação da Expressão Gênica , Humanos , Masculino , Mutação de Sentido Incorreto , Mutação Puntual , Polimorfismo de Fragmento de Restrição , Receptor de Interferon alfa e beta/biossíntese , Análise de Sequência de DNA
7.
Hong Kong Med J ; 14 Suppl 4: 36-8, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18708673

RESUMO

1. We have demonstrated for the first time that the helicase of a ribonucleic acid virus, the SARS coronavirus (SARS-CoV), is a valid target for drug development. 2. Using high throughput screen and chemical synthesis, several lead compounds targeting the SARS-CoV helicase have been identified. We have shown that these compounds can inhibit SARS-CoV helicase activity and viral growth in cell culture systems. These compounds can potentially be used to target other viruses.


Assuntos
DNA Helicases/farmacologia , Síndrome Respiratória Aguda Grave/tratamento farmacológico , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/efeitos dos fármacos , Replicação Viral/efeitos dos fármacos , Animais , Antivirais/farmacologia , Células Cultivadas , Chlorocebus aethiops , DNA Helicases/genética , Sistemas de Liberação de Medicamentos , Avaliação Pré-Clínica de Medicamentos , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/genética , Sensibilidade e Especificidade , Síndrome Respiratória Aguda Grave/genética , Síndrome Respiratória Aguda Grave/virologia , Células Vero/citologia , Células Vero/efeitos dos fármacos , Replicação Viral/genética
8.
Mol Cell Biol ; 15(7): 3960-8, 1995 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-7791801

RESUMO

The Drosophila melanogaster decapentaplegic (dpp) gene encodes a transforming growth factor beta-related cell signaling molecule that plays a critical role in dorsal/ventral pattern formation. The dpp expression pattern in the Drosophila embryo is dynamic, consisting of three phases. Phase I, in which dpp is expressed in a broad dorsal domain, depends on elements in the dpp second intron that interact with the Dorsal transcription factor to repress transcription ventrally. In contrast, phases II and III, in which dpp is expressed first in broad longitudinal stripes (phase II) and subsequently in narrow longitudinal stripes (phase III), depend on multiple independent elements in the dpp 5'-flanking region. Several aspects of the normal dpp expression pattern appear to depend on the unique properties of the dpp core promoter. For example, this core promoter (extending from -22 to +6) is able to direct a phase II expression pattern in the absence of additional upstream or downstream regulatory elements. In addition, a ventral-specific enhancer in the dpp 5'-flanking region that binds the Dorsal factor activates the heterologous hsp70 core promoter but not the dpp core promoter. Thus, the dpp core promoter region may contribute to spatially regulated transcription both by interacting directly with spatially restricted activators and by modifying the activity of proteins bound to enhancer elements.


Assuntos
Proteínas de Drosophila , Drosophila/genética , Regulação da Expressão Gênica , Hormônios de Inseto/genética , Regiões Promotoras Genéticas/genética , Transcrição Gênica , Animais , Sequência de Bases , Blastoderma , Análise Mutacional de DNA , Proteínas de Ligação a DNA/metabolismo , Drosophila/embriologia , Indução Embrionária , Elementos Facilitadores Genéticos/genética , Dados de Sequência Molecular , Ligação Proteica , Deleção de Sequência , Fatores de Transcrição/metabolismo
9.
Rev Sci Instrum ; 78(6): 065103, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17614634

RESUMO

A novel microcomputer-based ultrasonic distance measurement system is presented. This study proposes an efficient algorithm which combines both the amplitude modulation (AM) and the phase modulation (PM) of the pulse-echo technique. The proposed system can reduce error caused by inertia delay and amplitude attenuation effect when using the AM and PM envelope square wave form (APESW). The APESW ultrasonic driving wave form causes a phase inversion phenomenon in the relative wave form of the receiver. The phase inversion phenomenon sufficiently identifies the "measurement pulse" in the received wave forms, which can be used for accurate time-of-flight (TOF) measurement. In addition, combining a countertechnique to compute the phase shifts of the last cycle for TOF, the presented system can obtain distance resolution of 0.1% of the wavelength corresponding to the 40 kHz frequency of the ultrasonic wave. The standard uncertainty of the proposed distance measurement system is found to be 0.2 mm at a range of 50-500 mm. The APESW signal generator and phase detector of this measuring system are designed on a complex programmable logic device, which is used to govern the TOF measurement and send the data to a personal computer for distance calibration and examination. The main advantages of this APESW system are high resolution, low cost, narrow bandwidth requirement, and ease of implementation.


Assuntos
Eletrônica , Processamento de Sinais Assistido por Computador/instrumentação , Transdutores , Ultrassom , Desenho de Equipamento , Análise de Falha de Equipamento , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
11.
Water Sci Technol ; 54(9): 9-16, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-17163037

RESUMO

A process of granule disruption by hydrodynamic force is discussed in this paper. Shear force and attrition among granules originated from hydrodynamic force are the main causes of the disruption. Since it is positively correlated to the attrition force, the shear force is utilized to describe the effect of hydrodynamic force on granule disruption. In the experiment, when increase rate of average shear rate (IRgamma) of the 1st stage is about 0.2 s(-1) x d(-1), the granules are disrupted; while re-granulation could develop when IRgamma is about 0.07 s(-1) x d(-1); even when the shear rate is as high as about 30s(-1), the granulation rate keeps stably at a relatively high level, which shows that granules could bear the high hydrodynamic force only if it increases by low increase rate. The experimental results would be valuable for the operation and controlling of the upflow reactors.


Assuntos
Reatores Biológicos , Esgotos/microbiologia , Resistência ao Cisalhamento , Purificação da Água/métodos , Água/química , Aerobiose , Fatores de Tempo , Movimentos da Água , Purificação da Água/instrumentação
12.
Genetics ; 148(4): 1951-61, 1998 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-9560408

RESUMO

The mouse dilute (d) locus encodes unconventional myosin-VA (MyoVA). Mice carrying null alleles of dilute have a lightened coat color and die from a neurological disorder resembling ataxia and opisthotonus within three weeks of birth. Immunological and ultrastructural studies suggest that MyoVA is involved in the transport of melanosomes in melanocytes and smooth endoplasmic reticulum in cerebellar Purkinje cells. In studies described here, we have used an RT-PCR-based sequencing approach to identify the mutations responsible for 17 viable dilute alleles that vary in their effects on coat color and the nervous system. Seven of these mutations mapped to the MyoVA motor domain and are reported here. Crystallographic modeling and mutant expression studies were used to predict how these mutations might affect motor domain function and to attempt to correlate these effects with the mutant phenotype.


Assuntos
Proteínas de Filamentos Intermediários/genética , Mutagênese , Cadeias Pesadas de Miosina , Miosina Tipo V , Alelos , Animais , Cristalografia por Raios X , Feminino , Expressão Gênica , Cor de Cabelo/genética , Proteínas de Filamentos Intermediários/química , Masculino , Camundongos , Modelos Moleculares
13.
Genetics ; 148(4): 1963-72, 1998 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-9560409

RESUMO

We used an RT-PCR-based sequencing approach to identify the mutations responsible for 17 viable dilute alleles, a mouse-coat-color locus encoding unconventional myosin-VA. Ten of the mutations mapped to the MyoVA tail and are reported here. These mutations represent the first extensive collection of tail mutations reported for any unconventional mammalian myosin. They identify sequences important for tail function and identify domains potentially involved in cargo binding and/or proper folding of the MyoVA tail. Our results also provide support for the notion that different myosin tail isoforms produced by alternative splicing encode important cell-type-specific functions.


Assuntos
Proteínas de Filamentos Intermediários/genética , Mutagênese , Cadeias Pesadas de Miosina , Miosina Tipo V , Animais , Sequência de Bases , DNA , Feminino , Expressão Gênica , Proteínas de Filamentos Intermediários/biossíntese , Masculino , Camundongos , Camundongos Endogâmicos C3H , Camundongos Endogâmicos C57BL , Dados de Sequência Molecular , RNA Mensageiro , Deleção de Sequência
14.
Pharmacogenetics ; 6(3): 193-201, 1996 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-8807658

RESUMO

To standardize CYP2D6 allele nomenclature, and to conform with international human gene nomenclature guidelines, an alternative to the current arbitrary system is described. Based on recommendations for human genome nomenclature, we propose that alleles be designated by CYP2D6 followed by an asterisk and a combination of roman letters and arabic numerals distinct for each allele with the number specifying the key mutation and, where appropriate, a letter specifying additional mutations. Criteria for classification as a separate allele and protein nomenclature are also presented.


Assuntos
Alelos , Citocromo P-450 CYP2D6/genética , Terminologia como Assunto , Citocromo P-450 CYP2D6/metabolismo , Amplificação de Genes , Genótipo , Guias como Assunto , Humanos , Família Multigênica , Mutação
15.
Clin Pharmacol Ther ; 53(4): 410-8, 1993 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-8097442

RESUMO

Debrisoquin hydroxylation phenotype was determined in 124 Chinese persons living in Taiwan, and two poor metabolizers were identified with a urinary metabolic ratio (MR) greater than 12.6. The other subjects, extensive metabolizers, showed a normal frequency distribution of log(MR). Most subjects (50%) showed a 44/29 kb pattern in restriction fragment length polymorphism (RFLP) analysis with use of Xba I, and 30% and 15% of the subjects exhibited a homozygous 29/29 kb and 44/44 kb pattern, respectively. Among extensive metabolizers, subjects with the 44/44 kb pattern had a significant higher log(MR) than those with the 44/29 pattern, and the log(MR) of the subjects with the 44/29 kb pattern was significantly higher than that of the subjects with 29/29 kb pattern. All nine exons and intron 3 of C gamma P2D6 were amplified with polymerase chain reaction (PCR) and sequenced for four extensive metabolizers. Two major polymorphisms were found: one at position 188 of exon 1 and the other at position 4268 in exon 9. With PCR and endonuclease digestion, polymorphisms at exon 1, intron 3, and exon 9 were investigated. Only two of 254 alleles showed a heterozygous guanine at 1934 base pairs (G1934) to adenine (A) mutation, commonly found in white poor metabolizers. Approximately 70% of alleles showed thymine at 188 base pairs (T188), and 76% showed cytosine at 4268 base pairs (C4268) instead of C188 and G4268, as is found in most white subjects. Subjects with T188 or C4268 showed a significant higher log(MR) than subjects with homozygous C188 and G4268. The C/T188, G/A1934, G/C4268, and RFLP polymorphisms may explain the interracial variations between Chinese and white subjects, as well as the genetic variations among Chinese subjects.


Assuntos
Povo Asiático , Sistema Enzimático do Citocromo P-450/genética , DNA/química , Debrisoquina/metabolismo , Oxigenases de Função Mista/genética , Polimorfismo de Fragmento de Restrição , Adulto , Sequência de Bases , China/etnologia , Citocromo P-450 CYP2D6 , Sistema Enzimático do Citocromo P-450/metabolismo , Feminino , Genótipo , Homozigoto , Humanos , Hidroxilação , Masculino , Pessoa de Meia-Idade , Oxigenases de Função Mista/metabolismo , Dados de Sequência Molecular , Mutação , Fenótipo , Reação em Cadeia da Polimerase , Polimorfismo Genético , Taiwan
16.
Clin Pharmacol Ther ; 60(2): 177-82, 1996 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-8823235

RESUMO

Codeine and morphine pharmacokinetics among different CYP2D6 genotypes was compared in this study. Polymerase chain reaction tests were used to determine CYP2D6 genotypes in leukocyte deoxyribonucleic acid in 32 unrelated volunteers. Based on the genotypes, subjects were categorized into three groups: homozygous C/C188 (n = 8), heterozygous C/T188 (n = 12), and homozygous T/T188 (n = 12). Each subject was given a single oral dose of 30 mg codeine phosphate tablet after overnight fasting. Plasma concentration of codeine and 24-hour urinary morphine recovery were measured with HPLC. All three genotypes of subjects showed almost identical time profiles of plasma codeine. Urinary morphine glucuronide was hydrolyzed with beta-glucuronidase. The total recovered amount of morphine and glucuronides was 4349 +/- 646, 2564 +/- 242, and 1127 +/- 164 nmol (mean +/- SEM), respectively, for C/C188, C/T188, and T/T188 subjects (p < 0.05). The significant lower amount of urinary morphine but identical codeine plasma concentration suggested a lower partial clearance of the formation of morphine from codeine in T/T188 subjects. The results suggest a future study to assess the analgesic effect of codeine in different genotypes of CYP2D6 extensive metabolizers.


Assuntos
Povo Asiático/genética , Codeína/farmacocinética , Citocromo P-450 CYP2D6/genética , Morfina/urina , Adulto , Análise de Variância , Cromatografia Líquida de Alta Pressão , Codeína/sangue , Genótipo , Humanos , Masculino , Reação em Cadeia da Polimerase , Valores de Referência
17.
Clin Pharmacol Ther ; 58(3): 264-8, 1995 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-7554699

RESUMO

Propranolol pharmacokinetics among different genotypes of CYP2D6 was compared in this study. The Chinese (Han) population consisted of 44 healthy unrelated individuals living in southern Taiwan. Endonuclease tests based on polymerase chain reaction were used to determine C/T188 genotypes of CYP2D6 in leukocyte deoxyribonucleic acid. Based on codon 188 genotypes, subjects were categorized into three groups: homozygous C/C188 (n = 13), heterozygous C/T188 (n = 14); and homozygous T/T188 (n = 17). Each subject was given a 40 mg propranolol tablet. Blood samples were drawn before and 12 hours after propranolol administration to measure propranolol and 4-hydroxypropranolol. Three genotypes showed distinct time profiles of plasma propranolol and 4-hydroxypropranolol. The area under plasma concentration curve values (mean +/- SEM), were 322.0 +/- 40.8, 481.6 +/- 77.5, and 766.1 +/- 92.8 nmol.hr/L, respectively, for C/C188, C/T188, and T/T188 subjects (p < 0.05). The 48-hour excreted amount of 4-hydroxy-S-propranolol-O-glucuronide, but not 4-hydroxy-R-propranolol-O-glucuronide, was significantly higher for C/C188 than for T/T188 subjects (p < 0.05). This study shows a different propranolol disposition in Chinese subjects of different CYP2D6 genotypes.


Assuntos
Antagonistas Adrenérgicos beta/farmacocinética , Sistema Enzimático do Citocromo P-450/genética , Oxigenases de Função Mista/genética , Propranolol/farmacocinética , Antagonistas Adrenérgicos beta/sangue , Adulto , Citocromo P-450 CYP2D6 , Feminino , Genótipo , Heterozigoto , Homozigoto , Humanos , Individualidade , Masculino , Propranolol/sangue , Taiwan
18.
Biochem Pharmacol ; 59(6): 665-72, 2000 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-10677583

RESUMO

The effects of sodium deoxycholate (Deo-Na), a bile salt, and sodium caprate (Cap-Na), a fatty acid, on the transport of epirubicin were investigated in both the human colon adenocarcinoma (Caco-2) cell line and the everted gut sacs of the rat jejunum and ileum. The possible use of these two potent absorption enhancers as multidrug resistance (MDR) reversing agents also was examined. Epirubicin uptake experiments using a flow cytometer showed that Deo-Na and Cap-Na significantly increased the accumulation of epirubicin in Caco-2 cells. These two enhancers significantly increased apical to basolateral absorption of epirubicin across Caco-2 monolayers and mucosal to serosal absorption of epirubicin in the rat jejunum and ileum. Moreover, the addition of Deo-Na or Cap-Na significantly reduced the basolateral to apical efflux of epirubicin across Caco-2 monolayers. The co-presence of verapamil, one typical P-glycoprotein (P-gp) substrate, and Deo-Na or Cap-Na demonstrated further reduction of epirubicin efflux. The study suggests that inhibition of P-gp or other transporter proteins located in the intestines may be involved, at least partially, in the reduction of epirubicin efflux. In conclusion, the therapeutic efficacy of epirubicin may be improved by the use of such low toxicity excipients as absorption enhancers and MDR modulators in formulations.


Assuntos
Antibióticos Antineoplásicos/farmacocinética , Ácidos Decanoicos/farmacologia , Ácido Desoxicólico/farmacologia , Epirubicina/farmacocinética , Íleo/metabolismo , Jejuno/metabolismo , Animais , Transporte Biológico/efeitos dos fármacos , Células CACO-2 , Interações Medicamentosas , Citometria de Fluxo , Humanos , Íleo/efeitos dos fármacos , Absorção Intestinal/efeitos dos fármacos , Jejuno/efeitos dos fármacos , Masculino , Ratos , Ratos Sprague-Dawley
19.
Biochem Pharmacol ; 42(5): 1143-4, 1991 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-1872899

RESUMO

Phenytoin is known to be metabolized to form p-hydroxyphenyl-phenyl-hydantoin, possibly via the arene oxide intermediate. The reactive arene oxide may bind to macromolecules irreversibly and cause toxicity. In this study, valproic acid was found to increase the irreversible binding of phenytoin to rat liver microsomes at high concentrations. The effect was similar to that of TCPO and could be reversed by adding glutathione. Valproic acid may increase the hepatotoxicity of phenytoin.


Assuntos
Microssomos Hepáticos/metabolismo , Fenitoína/metabolismo , Ácido Valproico/farmacologia , Animais , Interações Medicamentosas , Glutationa/farmacologia , Ligação Proteica/efeitos dos fármacos , Ratos
20.
Biochem Pharmacol ; 46(8): 1511-4, 1993 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-8240404

RESUMO

The effects of sodium fluoride (NaF) and cobalt chloride (CoCl2) on the enantioselective hydrolysis of racemic oxazepam 3-acetate (rac-OXA) by microsomal and cytosolic esterases in rat intestinal mucosa were studied. Microsomal and cytosolic esterases hydrolyzed S-OXA and R-OXA in approximately 1:19 and 4:1 ratios, respectively. The hydrolysis of R-OXA by microsomal esterases was inhibited by NaF with an IC50 of 13.4 +/- 1.5 mM. Hydrolyses of both S-OXA and R-OXA by cytosolic esterases were inhibited by NaF with a similar IC50 value (approximately 3 mM). The hydrolysis of S-OXA by cytosolic esterases was inhibited by CoCl2 (IC50 = approximately 5 mM), whereas the hydrolysis of R-OXA by cytosolic esterases was stimulated by approximately 10% in the presence of 1 mM CoCl2. In comparison, the hydrolysis of R-OXA by microsomal esterases was stimulated by approximately 55% in the presence of 1 mM CoCl2. These results not only revealed the effects of NaF and CoCl2 on the catalytic activities of enantioselective cytosolic and microsomal esterases, but also indicated that microsomal and cytosolic esterases that selectively hydrolyzed R-OXA were distinctly different protein entities.


Assuntos
Cobalto/farmacologia , Esterases/antagonistas & inibidores , Mucosa Intestinal/efeitos dos fármacos , Fluoreto de Sódio/farmacologia , Animais , Citosol/enzimologia , Relação Dose-Resposta a Droga , Mucosa Intestinal/enzimologia , Mucosa Intestinal/ultraestrutura , Masculino , Microssomos/enzimologia , Oxazepam/metabolismo , Ratos , Ratos Sprague-Dawley , Estereoisomerismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA