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2.
Int J Ment Health Addict ; 21(2): 711-728, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-34642579

RESUMO

The COVID-19 is a "unique" stressor, which can produce physical and psychological trauma. Coping styles can buffer this psychological impact. Consequently, this paper aims to psychometrically adapt the Fear of COVID-19 scale (FCV-19S) to Spanish and examines the relationships between FCV-19S, stress response, and coping strategies. The sample comprised a convenience sample of 1146 participants (12-83 years), 880 from Spain (76.8%), and 266 from Dominican Republic (23.2%). Overall, the findings support a one-factor structure for FCV-19S, consisting of 7-items, and was invariant across age, sex, occupational status, and cross-national. Therefore, indicating evidences of construct validity. Evidences of reliability were also observed (Cronbach's α = .86, McDonald's ω = .86, Guttmann's λ6 = .86, greatest lower bound = .91, composite reliability = .85, and average variance extracted = .44). Moreover, as regards criterion-related validity, the mediation analysis indicated that the relationship between FCV-19S and acute stress was positive and high, with maladaptive coping styles mediating the relationship, and with a stronger mediation for men. The findings give evidences of the reliability and validity of the Spanish version of FCV-19S among Spanish-speaker participants, which provides the chance of cross-cultural studies.

3.
Int J Ment Health Addict ; : 1, 2021 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-34803548

RESUMO

[This corrects the article DOI: 10.1007/s11469-021-00615-x.].

4.
Hum Vaccin Immunother ; 17(11): 4225-4234, 2021 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-34495813

RESUMO

OBJECTIVES: To describe the trend in the frequency of adverse events (AE) records associated to pertussis component vaccines between January 1st, 2015 and June 30th, 2020 in infants younger than 2-years-old in Chile, by reviewing the records submitted to the AEFI NIP, stratified by DTP-vaccine type, wP or aP. MATERIALS AND METHODS: This was a retrospective observational study including all AEFI records of DTP (either aP or wP)-containing vaccines in the described sample. A descriptive analysis was performed according to vaccine type and AEFI, using MedDRA terminology. RESULTS: The total number of AEFI reports was 1,697: 815 corresponding to wP vaccines, 417 to aP vaccines, and 465 with unknown type. The reporting rates for the years 2015 to 2020 were 40.1, 56.2, 37.1, 24.7, 19.1, and 12.2 per 100,000 doses administered, respectively. The most reported AEFI were injection site erythema (42.9%), pyrexia (35.7%), and pain at the injection site (29.2%). Among all cases, 5.8% were SAEs (n = 98), 5.9% were SAEs for wP vaccines (n = 48) and 5.3% were for aP vaccines (n = 22). DISCUSSION: A significant decrease in AEFI reports was observed as of 2018, the year that the DTaP-IPV-HepB-Hib was introduced in the NIP.


Assuntos
Vacina contra Difteria, Tétano e Coqueluche , Vacinas contra Difteria, Tétano e Coqueluche Acelular , Pré-Escolar , Chile/epidemiologia , Vacina contra Difteria, Tétano e Coqueluche/efeitos adversos , Vacinas contra Difteria, Tétano e Coqueluche Acelular/efeitos adversos , Humanos , Lactente , Vacina contra Coqueluche/efeitos adversos , Estudos Retrospectivos , Vacinas Combinadas
5.
Phys Rev Lett ; 104(22): 227201, 2010 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-20867201

RESUMO

We examine the magnetic phase diagram of iron pnictides using a five-band model. For the intermediate values of the interaction expected to hold in the iron pnictides, we find a metallic low moment state characterized by antiparallel orbital magnetic moments. The anisotropy of the interorbital hopping amplitudes is the key to understanding this low moment state. This state accounts for the small magnetization measured in undoped iron pnictides and leads to the strong exchange anisotropy found in neutron experiments. Orbital ordering is concomitant with magnetism and produces the large zx orbital weight seen at Γ in photoemission experiments.

6.
Phys Rev Lett ; 105(20): 207202, 2010 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-21231260

RESUMO

Recent experiments on iron pnictides have uncovered a large in-plane resistivity anisotropy with a surprising result: The system conducts better in the antiferromagnetic x direction than in the ferromagnetic y direction. We address this problem by calculating the ratio of the Drude weight along the x and y directions, D(x)/D(y), for the mean-field Q=(π,0) magnetic phase diagram of a five-band model for the undoped pnictides. We find that D(x)/D(y) ranges between 0.2

7.
Rev Chilena Infectol ; 27(5): 407-10, 2010 Oct.
Artigo em Espanhol | MEDLINE | ID: mdl-21186505

RESUMO

During the latest Latin American epidemic of cholera (1991), more than 70,000 cases were identified and over 6,000 deaths occurred. Cholera started in Peru and expanded to the rest of Latin American countries, including Chile. Compared to Peru, the epidemic in Chile had minor consequences due to the strategies adopted by the National System of Health Services, together with other public institutions. These strategies included the establishment of a National Committee for Cholera, strategic planning of health services, strengthening of epidemiologic surveillance systems and of clinical and environmental laboratories, education of the population, and preventive strategies, among others. Maintenance of environmental health measures and the population's collaboration are essential to avoid future emergence of this disease.


Assuntos
Cólera/epidemiologia , Cólera/prevenção & controle , Epidemias , Planejamento em Saúde/organização & administração , Administração de Serviços de Saúde , Vigilância da População , Chile/epidemiologia , Meio Ambiente , Educação em Saúde/organização & administração , Humanos , América Latina/epidemiologia , Peru/epidemiologia , Saúde Pública , Fatores de Risco
8.
Rev Chilena Infectol ; 27(2): 133-7, 2010 Apr.
Artigo em Espanhol | MEDLINE | ID: mdl-20556313

RESUMO

The article summarizes the scientific evidence related with protection conferred by the 23 valent polysaccharide vaccine against invasive pneumococcal disease, non bacteraemic pneumococcal pneumonia, and probable pneumococcal pneumonia in the elderly. Eider patients with and without risk factors are considered. The impact of herd immunity conferred by vaccination of children with conjugated pneumococcal vaccine in reduction of pneumonia in adults is discussed. Based on this analysis, the Advisory Committee on Immunizations of the Chilean Infectious Disease Society makes recommendations on the most efficient vaccine strategy for reduction of pneumococcal pneumonia in the elderly.


Assuntos
Medicina Baseada em Evidências , Metanálise como Assunto , Infecções Pneumocócicas/prevenção & controle , Vacinas Pneumocócicas/administração & dosagem , Streptococcus pneumoniae/imunologia , Adulto , Comitês Consultivos , Chile , Humanos , Pessoa de Meia-Idade , Vacinas Pneumocócicas/efeitos adversos , Vacinas Pneumocócicas/imunologia , Pneumonia Pneumocócica/prevenção & controle , Sociedades Médicas
9.
Theriogenology ; 146: 1-13, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-32035360

RESUMO

Starting in vitro fertilization process with competent oocytes that may endure first cellular divisions is a critical step for obtaining an embryo. To obtain in vitro competent oocytes, culture conditions should emulate the in vivo microenvironment as close as possible. With the aim of improving the in vitro culture medium, the present study evaluated the IMD/ADM21-47 peptide as a factor that promotes oocyte competence and improves embryo quality in bovine systems. The culture supplemented with 153 µg/mL of IMD/ADM21-47 was correlated with the production of healthy oocytes in metaphase II (MII) stage in compacted cumulus-oocyte complexes (COC) with a decrease of BAX/BCL-2 to mRNA ratio and a reduction of late apoptosis by TUNEL in MII oocytes. In addition to this, treatment with IMD/ADM21-47 caused cAMPi level to be constant over time, and the cAMPi level kept increasing until 6 h. COC supplementation with 153 µg/mL of IMD/ADM21-47 increased the blastocyst production rate two-fold in comparison with control conditions. Only embryos from COC treatment with this peptide were capable of developing blastocysts in stage-6 grade I; compared with the control culture, it was the treatment with the greater number of blastocysts stage-5; these are characteristics of good quality blastocysts.


Assuntos
Bovinos/embriologia , Desenvolvimento Embrionário/efeitos dos fármacos , Técnicas de Maturação in Vitro de Oócitos/veterinária , Peptídeos e Proteínas de Sinalização Intercelular/farmacologia , Sequência de Aminoácidos , Animais , Biologia Computacional , Cultura , Regulação da Expressão Gênica/efeitos dos fármacos , Modelos Moleculares , Conformação Proteica , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Proteína X Associada a bcl-2/genética , Proteína X Associada a bcl-2/metabolismo
10.
Rev Chilena Infectol ; 25(6): 447-52, 2008 Dec.
Artigo em Espanhol | MEDLINE | ID: mdl-19194609

RESUMO

For the international scientific community, it is undoubted that planetary temperature is increasing, being projected an average raise of 1.0 degrees C-3.5 degrees C by the year 2100. Forecasted consequences are diverse, most of them adverse for human health, including the establishment of favorable epidemiological scenarios for the emergence and reemergence of infectious diseases. The present article summarizes the available evidence regarding the mechanisms that promote climate change, its environmental effects and its consequences on human health. In order to accomplish this objective, demonstrated changes in the dynamics of zoonotic, vectorial, food and water-borne diseases are described. The position of Chile in the international community is commented, as well as multiple pending challenges, among which outstands the importance of incorporating professionals that work in the health sector to the national debate.


Assuntos
Clima , Doenças Transmissíveis , Temperatura Alta , Chile , Doenças Transmissíveis/epidemiologia , Doenças Transmissíveis/etiologia , Doenças Transmissíveis/transmissão , Saúde Global , Humanos , Medição de Risco
11.
Rev Chilena Infectol ; 25(6): 428-34, 2008 Dec.
Artigo em Espanhol | MEDLINE | ID: mdl-19194605

RESUMO

The article briefly reviews the epidemiology of human papillomavirus (HPV) infection and associated diseases in the world and in Chile and the scientific information of the licensed HPV vaccines: Gardasil and Cervarix. Considering the available information, the Consultive Committee of Immunizations of the Chilean Society of Infectious Diseases, summarizes its conclusions and makes recommendations for vaccination against HPV in Chile.


Assuntos
Comitês Consultivos , Alphapapillomavirus/imunologia , Infecções por Papillomavirus/prevenção & controle , Vacinas contra Papillomavirus , Adolescente , Adulto , Chile/epidemiologia , Feminino , Vacina Quadrivalente Recombinante contra HPV tipos 6, 11, 16, 18 , Humanos , Pessoa de Meia-Idade , Infecções por Papillomavirus/epidemiologia , Vacinas contra Papillomavirus/efeitos adversos , Vacinas contra Papillomavirus/imunologia , Sociedades Médicas , Adulto Jovem
12.
Rev. chil. nutr ; 50(3)jun. 2023.
Artigo em Espanhol | LILACS-Express | LILACS | ID: biblio-1515180

RESUMO

La composición química del aceite de oliva extra virgen (AOEV) se compone principalmente de triglicéridos, ácidos grasos insaturados como ácido oleico, ácido linoleico y el α-linolénico. También se destacan compuestos fenólicos de tres clases químicas: simples, secoiridoides y lignanos. En la presente revisión se analizó el consumo del AOEV en enfermedades crónicas, ciertos tipos de cáncer y en enfermedades neurodegenerativas. La evidencia muestra que el consumo de entre 8 y 40 g de AOEV diario tiene efectos protectores en enfermedades cardiovasculares, puede evitar la aparición de diabetes tipo 2 y aumentar los niveles de colesterol HDL. Respecto al cáncer, entre los efectos evaluados se destacan los encontrados a partir de los compuestos fenólicos hidroxitirosol (HT) y oleocantal, los que han demostrado un efecto protector en algunos tipos de cáncer como cáncer de piel y de mama. En las enfermedades neurodegenerativas, se observó que el consumo diario de 50 g de AOEV, tiene un efecto inhibidor en la degeneración neuronal atribuido a sus compuestos fenólicos como oleuropeina e HT. Investigaciones a futuro debieran enfocarse en determinar los efectos a largo plazo del consumo de AOEV en las diferentes enfermedades analizadas, para así poder ir estableciendo la "dosis" de AOEV que permita obtener resultados protectores sobre la salud. Además de explorar los efectos de las diferentes variedades de aceitunas (con sus componentes bioactivos particulares) con el fin de establecer los efectos en la salud y enfermedad asociados a variedades específicas.


The chemical composition of extra virgin olive oil (EVOO) is mainly composed of triglycerides, unsaturated fatty acids such as oleic acid, linoleic acid, and α-linolenic acid. Phenolic compounds of three chemical classes are also relevant, such as simple, secoiridoids, and lignans. Here, we review the association between EVOO consumption and chronic diseases, certain types of cancer, and neurodegenerative diseases. Evidence shows that consuming between 8 and 40 g of EVOO / day has protective effects on cardiovascular diseases, can prevent the onset of type 2 diabetes, and increases HDL cholesterol levels. Regarding cancer, phenolic compounds hydroxytyrosol (HT) and oleocanthal have protective effects on some types of cancer, such as skin and breast cancer. Regarding neurodegenerative diseases, daily consumption of phenolic compounds such as oleuperin and hydroxytyrosol and 50 g of EVOO has an inhibitory effect on neuronal degeneration and a protective effect on neuroprotective capacity. Future research should focus on determining the long-term impact of EVOO consumption on different diseases to establish the "dose" of EVOO that will allow health-protective results. It is also necessary to establish the effects of the specific olives (with their particular bioactive components) to establish the different impacts on health and disease associated with olives varieties.

13.
Clin Transl Oncol ; 20(6): 785-793, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29159791

RESUMO

PURPOSE: The present study evaluates the massive study of gene expression in metastatic breast carcinoma (MBC) patients using microarray gene expression profiling (MAGE) complemented with conventional sequencing, immunohistochemistry (IHC) and fluorescent "in situ" hybridization (FISH), seeking to optimize the treatment in a subset of heavily pretreated patients and with limited life expectancy. PATIENTS, MATERIAL AND METHODS: MBC patients in hormone therapy progression with survival expectancy of at least 3 months (m) have been included. The MAGE contains gene probes representing genes known to potentially interact with available drugs as cited in the literature. RESULTS: Thirty-nine procedures were performed from October 2010 to April 2016. Within the 30 evaluable procedures, considering all hormonal manipulations as a single line, the patients had received a median of 4 treatment lines prior to MAGE (range 1-7). Progression was observed in 6 cases, stable disease (SD) in 7 cases and partial response (PR) in 16 cases, which implies a clinical benefit rate (SD + PR) of 76%. Actuarial median progression-free survival (PFS) was 6 m (95% CI 2.5-9.5) in patients with clinical benefit. The median overall survival (OS) for the entire series was 11 m (95% CI 2.2-19.8). CONCLUSION: Data presented here indicate that the use of MAGE provides relevant information to establish personalized treatment in frail patients with limited life expectancy in which therapeutic futility is a particularly difficult burden to assume.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Biomarcadores Tumorais/genética , Neoplasias da Mama/genética , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Medicina de Precisão , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/secundário , Feminino , Seguimentos , Humanos , Pessoa de Meia-Idade , Metástase Neoplásica , Projetos Piloto , Prognóstico , Taxa de Sobrevida
14.
Rev Chilena Infectol ; 24(5): 372-6, 2007 Oct.
Artigo em Espanhol | MEDLINE | ID: mdl-17989841

RESUMO

Thimerosal is a mercury derivative included in vaccines since 1930 with the aim to prevent microbial contamination. During the last decades, the use of thimerosal has been questioned, specifically because of a potential association with neurotoxicity. After a thorough review of published studies on pediatric use of thimerosal-containing vaccines, and of position papers from international expert groups, the Consultive Committee of Immunizations of the Chilean Society of Infectious Diseases concludes that there is no solid evidence of adverse events associated with the use of thimerosal containing vaccines in infants and children. Therefore, a change in current vaccine practices refererred to thimerosal-containing vaccines is not justified in Chile.


Assuntos
Conservantes Farmacêuticos , Timerosal , Vacinas/química , Transtorno Autístico/induzido quimicamente , Criança , Chile , Humanos , Lactente , Conservantes Farmacêuticos/efeitos adversos , Padrões de Referência , Sociedades Médicas , Timerosal/efeitos adversos , Vacinas/efeitos adversos
15.
Rev. Hosp. Clin. Univ. Chile ; 33(2): 108-119, 2022. tab
Artigo em Espanhol | LILACS | ID: biblio-1401171

RESUMO

Vogt-Koyanagi-Harada disease (VKH) is an autoimmune multisystemic syndrome that includes bilateral intraocular inflammation, associated with exudative retinal detachments, and systemic manifestations in the auditory, integumentary, and central nervous systems. The frequency of VKH disease in the world is variable, but in Santiago, Chile, it causes approximately 17% of non-infectious uveitis, an incidence 2 to 3-fold greater than in the USA or European countries. The evidence shows that the pathogenesis of VKH would be caused by cell-mediated autoimmunity directed against melanocytes present in the uveal tissue. CD4+ T lymphocytes (especially hyperactivity of Th17 and Th1 cells), B lymphocytes, cytokines (e.g., TGF-ß, IL-2, IL-6, IL-23 and INF-γ) and chemokines appear to play an important role in the development of VKH. Several lines of evidence support that the pathogenesis of uveitis observed in VKH involves an altered pattern of micro-ribonucleic acids (miRNA) expression, driving the loss of immunological tolerance. In this review, we discuss the evidence related to regulation and altered expression of miRNA associated with Vogt-Koyanagi-Harada and other autoimmune diseases. (AU)


Assuntos
Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Síndrome Uveomeningoencefálica/fisiopatologia , MicroRNAs/genética , Doenças Autoimunes/fisiopatologia , Síndrome Uveomeningoencefálica/genética , Síndrome Uveomeningoencefálica/epidemiologia
16.
Int J Pharm ; 314(1): 21-30, 2006 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-16574353

RESUMO

The objective was to develop a semiphysiological population pharmacokinetic model that describes the complex salbutamol sulphate absorption in rat small intestine. In situ techniques were used to characterize the salbutamol sulphate absorption at different concentrations (range: 0.15-18 mM). Salbutamol sulphate at concentration of 0.29 mM was administered in presence of verapamil (10 and 20 mM), grapefruit juice and sodium azide (NaN3) (0.3, 3 and 6 mM). Different pharmacokinetic models were fitted to the dataset using NONMEM. Parametric and non-parametric bootstrap analyses were employed as internal model evaluation techniques. The validated model suggested instantaneous equilibrium between salbutamol sulphate concentrations in lumen and enterocyte, and the salbutamol sulphate absorption was best described by a simultaneous passive diffusion (ka = 0.636 h(-1)) and active absorption (VMax = 0.726 mM/h, Km = 0.540 mM) processes from intestinal lumen to enterocyte, together with an active capacity-limited P-gp efflux (V'max = 0.678 mM/h, K'm = 0.357 mM) from enterocyte to intestinal lumen. The extent of salbutamol sulphate absorption in rat small intestine can be improved by NaN3, grapefruit juice and verapamil.


Assuntos
Agonistas Adrenérgicos beta/farmacocinética , Albuterol/farmacocinética , Absorção Intestinal/fisiologia , Modelos Biológicos , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/antagonistas & inibidores , Animais , Bebidas , Disponibilidade Biológica , Transporte Biológico Ativo/fisiologia , Citrus paradisi , Citocromo P-450 CYP3A , Inibidores das Enzimas do Citocromo P-450 , Relação Dose-Resposta a Droga , Intestino Delgado/metabolismo , Masculino , Ratos , Ratos Wistar , Azida Sódica/farmacologia , Verapamil/farmacologia
17.
Rev Chilena Infectol ; 23(2): 124-7, 2006 Jun.
Artigo em Espanhol | MEDLINE | ID: mdl-16721445

RESUMO

The article briefly reviews the epidemiology of rotavirus infection and the scientific information of the rotavirus vaccines: Rotashield, withdrawn from the market due to its association with intussusception, Rotateq currently in an advanced phase of development, and Rotarix, recently licensed in Chile. Considering the available information, the Consultive Committee of Immunizations of the Chilean Society of Infectious Diseases, summarizes its conclusions and makes recommendations for infants vaccination against rotavirus in our country.


Assuntos
Infecções por Rotavirus/prevenção & controle , Vacinas contra Rotavirus/administração & dosagem , Vacinas Atenuadas/administração & dosagem , Comitês Consultivos , Fatores Etários , Animais , Bovinos , Chile/epidemiologia , Aprovação de Drogas , Gastroenterite/virologia , Humanos , Lactente , Intussuscepção/etiologia , Infecções por Rotavirus/epidemiologia , Vacinas contra Rotavirus/efeitos adversos , Vacinas contra Rotavirus/imunologia , Sociedades Médicas , Vacinas Atenuadas/efeitos adversos , Vacinas Atenuadas/imunologia
18.
Vet Immunol Immunopathol ; 164(1-2): 93-100, 2015 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-25631788

RESUMO

Ribavirin is a synthetic nucleotide analog capable of inhibiting or even preventing some viral infections in mammals and also in fish. It has been seen by others that ribavirin by itself is able to stimulate the immune system of mammals, causing a differentiation of T-cells to T helper 1 cells (Th)-1. In this work, we evaluated the immune effect of ribavirin in vitro on kidney cells from Atlantic salmon and in vivo by oral administration of ribavirin to Atlantic salmon. For this purpose, the transcripts of immune molecules Tbet, GATA3, CD8, CD4, IFNα, IFNγ, IL-4/13, IL-10, IL-12, IL-15 and TGF-B were quantified. The results show that ribavirin administered orally in food to Atlantic salmon increased IFNγ and CD4 transcripts in the in vivo assays and, in addition, increased IL-12, IL-15 and CD8 in the in vitro analyses, indicating that the treatment stimulates a Th1 type response in salmon.


Assuntos
Antivirais/farmacologia , Ribavirina/farmacologia , Salmo salar/imunologia , Adjuvantes Imunológicos/farmacologia , Animais , Citocinas/genética , Proteínas de Peixes/genética , Proteínas de Peixes/imunologia , Expressão Gênica/efeitos dos fármacos , Técnicas In Vitro , Rim/citologia , Rim/efeitos dos fármacos , Rim/imunologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Salmo salar/genética , Células Th1/efeitos dos fármacos , Células Th1/imunologia
19.
Arch Med Res ; 23(2): 77-80, 1992.
Artigo em Inglês | MEDLINE | ID: mdl-1285087

RESUMO

The nuclear division of E. histolytica trophozoites was analyzed by using specific stains for DNA, with the aim to define the sequential changes of chromatin during its life cycle. Furthermore, we characterized the internal structural arrangements of microtubules in the microtubular organizing center (MTOC) and determined the number of chromosomes and its association with the spindle. The MTOC is formed by multiple microtubule-nucleating centers, that are involved in the displacement of DNA during nuclear division. We found the existence of a single MTOC in one pole of the nucleus at early anaphase. Our results lead us to propose a new hypothesis in which it is suggested that metaphase corresponds to the arrangement of condensed DNA bodies, or "chromosomes" around the MTOC and, through the assembly of microtubules, one set of uncondensed chromatin is displaced to the opposite pole of the nucleus, while the other remains condensed and associated to the original MTOC. We observed six chromosomes in our preparations, corroborating previous observations (2,3). Whether or not a new MTOC is formed during nuclear division remains to be clarified.


Assuntos
Cromatina/ultraestrutura , Entamoeba histolytica/ultraestrutura , Animais , Ciclo Celular , Divisão Celular , DNA de Protozoário/análise , Entamoeba histolytica/crescimento & desenvolvimento , Microtúbulos/ultraestrutura , Fuso Acromático/ultraestrutura , Coloração e Rotulagem
20.
Eur J Pharm Biopharm ; 52(1): 31-7, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11438421

RESUMO

Salbutamol was perfused in the small intestine of rat using a standard rat gut "in situ" preparation: (1) in inhibitor-free solution at seven different concentrations (0.15, 0.29, 1.20, 5.0, 9.0, 13.0 and 18.0mM); (2) at a 0.29mM concentration - thought to be close to the allometric dose in man - in the presence of a non-specific enzyme inhibitor, sodium azide (0.3, 3.0 and 6.0mM); and (3) at 0.29mM in the presence of a selective secretion inhibitor, verapamil (10.0 and 20.0mM). In free solution, the mixed-order rate constants, k'(a), of salbutamol increase as the solute concentration increases until an apparent asymptotic value is reached. This could be due to the saturation of enzymatic systems responsible for the secretion of the drug from the enterocyte to the luminal fluid, a process that could explain the poor absorption of salbutamol. In the presence of sodium azide, the k(a) values increased about 1.5-fold, whereas in the presence of verapamil they increased two- to three-fold. These results indicate that salbutamol can act as a substrate of an intestinal secretory transport, which probably includes--at least in part--the enzyme P-glycoprotein, since verapamil has been shown to inhibit this enzyme by dose-dependent competition. This leads to a secretion-limited peroral absorption of salbutamol, which contributes to the poor oral bioavailability of the drug. The possible options for improving salbutamol absorption are discussed.


Assuntos
Agonistas Adrenérgicos beta/farmacocinética , Albuterol/farmacocinética , Absorção Intestinal , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/fisiologia , Animais , Relação Dose-Resposta a Droga , Masculino , Ratos , Ratos Wistar , Azida Sódica/farmacologia , Verapamil/farmacologia
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