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1.
Braz. j. microbiol ; 47(4): 917-924, Oct.-Dec. 2016. tab, graf
Article in English | LILACS | ID: biblio-828189

ABSTRACT

Abstract This study aimed to evaluate the in vitro antifungal activity of terpinen-4-ol, tyrosol, and β-lapachone against strains of Coccidioides posadasii in filamentous phase (n = 22) and Histoplasma capsulatum in both filamentous (n = 40) and yeast phases (n = 13), using the broth dilution methods as described by the Clinical and Laboratory Standards Institute, to determine the minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of these compounds. The mechanisms of action of these compounds were also investigated by analyzing their effect on cell membrane permeability and ergosterol synthesis. The MIC and MFCf these compounds against C. posadasii, mycelial H. capsulatum, and yeast-like H. capsulatum, were in the following ranges: 350-5720 µg/mL, 20-2860 µg/mL, and 40-1420 µg/mL, respectively for terpinen-4-ol; 250-4000 µg/mL, 30-2000 µg/mL, and 10-1000 µg/mL, respectively, for tyrosol; and 0.48-7.8 µg/mL, 0.25-16 µg/mL, and 0.125-4 µg/mL, respectively for β-lapachone. These compounds showed a decrease in MIC when the samples were subjected to osmotic stress, suggesting that the compounds acted on the fungal membrane. All the compounds were able to reduce the ergosterol content of the fungal strains. Finally, tyrosol was able to cause a leakage of intracellular molecules.


Subject(s)
Phenylethyl Alcohol/analogs & derivatives , Terpenes/pharmacology , Naphthoquinones/pharmacology , Fungi/drug effects , Antifungal Agents/pharmacology , Osmotic Pressure , Phenylethyl Alcohol/pharmacology , Microbial Sensitivity Tests , Cell Membrane Permeability/drug effects , Ergosterol/metabolism , Fungi/classification , Fungi/metabolism
2.
Braz. j. microbiol ; 47(2): 381-388, Apr.-June 2016. tab, graf
Article in English | LILACS | ID: lil-780828

ABSTRACT

Abstract Pan-drug resistant Gram-negative bacteria, being resistant to most available antibiotics, represent a huge threat to the medical community. Colistin is considered the last therapeutic option for patients in hospital settings. Thus, we were concerned in this study to demonstrate the membrane permeabilizing activity of colistin focusing on investigating its efficiency toward those pan-drug resistant isolates which represent a critical situation. We determined the killing dynamics of colistin against pan-drug resistant isolates. The permeability alteration was confirmed by different techniques as: leakage, electron microscopy and construction of an artificial membrane model; liposomes. Moreover, selectivity of colistin against microbial cells was also elucidated. Colistin was proved to be rapid bactericidal against pan-drug resistant isolates. It interacts with the outer bacterial membrane leading to deformation of its outline, pore formation, leakage of internal contents, cell lysis and finally death. Furthermore, variations in membrane composition of eukaryotic and microbial cells provide a key for colistin selectivity toward bacterial cells. Colistin selectively alters membrane permeability of pan-drug resistant isolates which leads to cell lysis. Colistin was proved to be an efficient last line treatment for pan-drug resistant infections which are hard to treat.


Subject(s)
Humans , Cell Membrane/metabolism , Gram-Negative Bacterial Infections/microbiology , Colistin/metabolism , Drug Resistance, Multiple, Bacterial , Gram-Negative Bacteria/metabolism , Anti-Bacterial Agents/metabolism , Microbial Sensitivity Tests , Cell Membrane/drug effects , Cell Membrane Permeability , Gram-Negative Bacterial Infections/drug therapy , Colistin/pharmacology , Gram-Negative Bacteria/isolation & purification , Gram-Negative Bacteria/drug effects , Gram-Negative Bacteria/ultrastructure , Anti-Bacterial Agents/pharmacology
3.
Article in Chinese | WPRIM | ID: wpr-264066

ABSTRACT

<p><b>OBJECTIVE</b>To investigate the effect of c-Met inhibitor cabozantinib (XL-184) in inhibiting Listeria monocytogenes (LM) from invading Caco-2 cells to reduce the cell injury.</p><p><b>METHODS</b>The cell invasion capacity of LM was assayed in Caco-2 cells incubated with different doses of XL-184 for different durations. Caco-2 cells incubated with XL-184 were seeded on the upper room of the transwell chamber, and the cell monolayer was exposed to LM infection followed by addition of horseradish peroxidase (HRP). The trans-epithelial electric resistance (TEER), HRP concentration and LM colony-forming unit (CFU) were measured in the cell monolayer. Fluorescent staining was used to evaluate the cell viability, and LDH release from the cells was examined to assess the changes in cell membrane permeability.</p><p><b>RESULTS</b>XL-184 significantly decreased LM invasion rate in Caco-2 cells in a dose- and time-dependent manner (P=0.000), and this effect was enhanced by co-incubation of the cells with ampicillin (P<0.05). In the cell membrane permeability assay in the monolayer cells, XL-184 markedly inhibited LM-induced reduction of TEER (P<0.05) and significantly suppressed LM-induced enhancement of cell membrane permeability shown by reduced HRP concentration and LM count in the lower chamber (P=0.000). The cells infected with LM showed significantly lowered cell viability, which was rescued by XL-184 (P<0.01); XL-184 also dose-dependently reduced LDH release from the cells (P<0.05).</p><p><b>CONCLUSIONS</b>XL-184 can suppress LM invasion in Caco-2 cells to reduce the cell injury, suggesting its value as a promising candidate agent for prevention and treatment of LM infections.</p>


Subject(s)
Anilides , Pharmacology , Caco-2 Cells , Cell Membrane Permeability , Cell Survival , Humans , Listeria monocytogenes , Pyridines , Pharmacology
4.
National Journal of Andrology ; (12): 133-137, 2016.
Article in Chinese | WPRIM | ID: wpr-304738

ABSTRACT

<p><b>OBJECTIVE</b>To culture rat prostate glandular epithelial cells and study their barrier functions in vitro.</p><p><b>METHODS</b>Rat prostate glandular epithelial cells were cultured in vitro. The expression of the tight junction protein claudin-1 was determined by immunohistochemistry, the structure and composition of the epithelial cells observed under the inverted microscope and transmission electron microscope. The transepithelial electrical resistances (TEERs) were monitored with the Millicell system. The permeability of the prostate glandular epithelial cells was assessed by the phenol red leakage test.</p><p><b>RESULTS</b>Compact monolayer cell structures were formed in the prostate glandular epithelial cells cultured in vitro. Immunohistochemistry showed the expression of the tight junction protein claudin-1 and transmission electron microscopy confirmed the formation of tight junctions between the adjacent glandular epithelial cells. The TEERs in the cultured prostate glandular epithelial cells reached the peak of about (201.3 ± 3.5) Ω/cm2 on the 8th day. The phenol red leakage test manifested a decreased permeability of the cell layers with the increase of TEERs.</p><p><b>CONCLUSION</b>The structure and function of rat prostate glandular epithelial cells are similar to those of brain capillary endothelial cells, retinal capillary endothelial cells, and intestinal epithelial cells. In vitro cultured prostate glandular epithelial cells have the barrier function and can be used as a model for the study of blood prostate barrier in vitro.</p>


Subject(s)
Animals , Cell Membrane Permeability , Cells, Cultured , Claudin-1 , Metabolism , Electric Impedance , Epithelial Cells , Pathology , Physiology , In Vitro Techniques , Male , Microscopy, Electron, Transmission , Phenolsulfonphthalein , Pharmacokinetics , Prostate , Metabolism , Pathology , Rats , Tight Junctions
5.
Clinics ; 70(8): 569-576, 08/2015. tab, graf
Article in English | LILACS | ID: lil-753961

ABSTRACT

OBJECTIVE: The aim of this study was to determine the in vitro effect of glutamine and insulin on apoptosis, mitochondrial membrane potential, cell permeability, and inflammatory cytokines in hyperglycemic umbilical vein endothelial cells. MATERIALS AND METHODS: Human umbilical vein endothelial cells were grown and subjected to glutamine and insulin to examine the effects of these agents on the hyperglycemic state. Mitochondrial function and the production of inflammatory cytokines were assessed using fluorescence analysis and multiple cytotoxicity assays. Apoptosis was analyzed by the terminal deoxynucleotidyl transferase dUTP nick end-labeling assay. RESULTS: Glutamine maintains the integrity of the mitochondria by reducing the cell permeability and cytochrome c levels and increasing the mitochondrial membrane potential. The cytochrome c level was significantly (p<0.005) reduced when the cells were treated with glutamine. An apoptosis assay revealed significantly reduced apoptosis (p<0.005) in the glutamine-treated cells. Moreover, glutamine alone or in combination with insulin modulated inflammatory cytokine levels. Interleukin-10, interleukin-6, and vascular endothelial growth factor were up-regulated while tumor necrosis factor-α was down-regulated after treatment with glutamine. CONCLUSION: Glutamine, either alone or in combination with insulin, can positively modulate the mitochondrial stress and cell permeability in umbilical vein endothelial cells. Glutamine regulates the expression of inflammatory cytokines and maintains the balance of the mitochondria in a cytoprotective manner. .


Subject(s)
Humans , Apoptosis/drug effects , Glutamine/pharmacology , Hyperglycemia/drug therapy , Mitochondria/drug effects , Oxidative Stress/drug effects , Cells, Cultured , Cell Membrane Permeability/drug effects , Cytochromes c/analysis , Cytokines/analysis , Cytokines/drug effects , Drug Combinations , Human Umbilical Vein Endothelial Cells/drug effects , Human Umbilical Vein Endothelial Cells/metabolism , Hyperglycemia/metabolism , Hypoglycemic Agents/pharmacology , Insulin/pharmacology , Mitochondria/metabolism
6.
Rev. chil. pediatr ; 86(4): 264-269, ago. 2015. graf, tab
Article in Spanish | LILACS | ID: lil-764083

ABSTRACT

Introducción: La alopecia infantil es una afección poco frecuente en la consulta dermatológica pediátrica. Su etiología es variable según el grupo etario estudiado. El objetivo fue estudiar la causa de alopecia en niños en 2 hospitales pediátricos de referencia nacional en Chile. Pacientes y método: Análisis descriptivo de registros clínicos del total de pacientes atendidos entre enero de 2007 y junio de 2010 en los Servicios de Dermatología de los Hospitales Roberto del Río y Luis Calvo Mackenna. Se incluyeron pacientes con diagnóstico clínico de alopecia. Resultados: Se encontraron 345 registros clínicos, 179 varones (51,9%). La mediana de edad fue 72 meses. Los diagnósticos más prevalentes fueron alopecia areata (AA) (36,8%), tiña capitis (TC) (21%), nevo sebáceo (13,2%) y efluvio telógeno (8,7%). Según el grupo etario predominaron en recién nacidos: aplasia cutis y nevo sebáceo; en lactantes, preescolares y escolares: nevo sebáceo, AA y TC. En escolares se agregó tricotilomanía. En adolescentes nevo sebáceo, AA y efluvio telógeno. Se observó una correlación significativa entre AA con enfermedad autoinmune, enfermedad tiroidea, alteraciones ungueales, enfermedad psiquiátrica y síndrome de Down. En TC el agente etiológico más prevalente fue Microsporum Canis (86,6%). La tricotilomanía se correlacionó con enfermedad psiquiátrica significativamente. Conclusiones: Las principales causas de alopecia infantil fueron adquiridas y no cicatriciales. La etiología varía de acuerdo al grupo etario estudiado. Algunos tipos de alopecia infantil presentaron alta prevalencia de enfermedad psiquiátrica.


Introduction: Childhood alopecia is a relative rare event in general paediatric dermatology practice. Hair loss in children may have multiple causes, and there are different types of alopecia according to age groups. The aim of the study was to describe the clinical and epidemiological profile of alopecia in children from two Chilean paediatric hospitals. Patients and method: Descriptive analysis of clinical records of patients from the Dermatology Department of Roberto del Rio and Luis Calvo Mackenna Hospitals between January 2007 and June 2010. Patients with clinical diagnosis of alopecia were included. Results: A total of 345 clinical records were analysed, with 179 males (51.9%). The median age was 72 months. Overall, the most common diagnoses were: alopecia areata (AA), (36.8%), tinea capitis (TC), (21%), nevus sebaceous (13.2%), and tellogen effluvium (8.7%). According to age groups, in newborns, the most common causes were aplasia cutis and nevus sebaceous. In toddlers, pre-school and school children, the principal causes were nevus sebaceous, AA and TC. Trichotillomania was also significant in school children. In adolescents, nevus sebaceous, AA and tellogen effluvium were the most frequent diagnoses. AA was statistically associated with autoimmune disease, thyroid disease, nail disorder, psychiatric disease, and Down's syndrome. The most common aetiological agent in TC was M. canis (86.6%). Trichotillomania was also statistically associated to psychiatric disorders. Conclusions: In this study, the main causes of alopecia in children were acquired and non-scarring alopecia. In our results, the type of alopecia varies according to age group. Some types of childhood alopecia showed a close correlation to psychiatric disorders.


Subject(s)
Humans , Cell Membrane Permeability/physiology , Claudins/metabolism , Epithelial Cells/metabolism , Epithelial Cells/physiology , Harringtonines/metabolism , Intestines/metabolism , Protein Isoforms/metabolism , Cell Line, Tumor , Dextrans/metabolism , /analogs & derivatives , /metabolism , Intestines/physiology , Tight Junctions/metabolism , Tight Junctions/physiology , Transcription, Genetic/physiology
7.
Int. arch. otorhinolaryngol. (Impr.) ; 19(1): 93-95, Jan-Mar/2015. graf
Article in English | LILACS | ID: lil-741535

ABSTRACT

Introduction Schwannoma of the olfactory groove is an extremely rare tumor that can share a differential diagnosis with meningioma or neuroblastoma. Objectives The authors present a case of giant schwannoma involving the anterior cranial fossa and ethmoid sinuses. Case Report The patient presented with a 30-month history of left nasal obstruction, anosmia, and sporadic ipsilateral bleeding. Computed tomography of the paranasal sinuses revealed expansive lesion on the left nasal cavity extending to nasopharynx up to ethmoid and sphenoid sinuses bilaterally with intraorbital and parasellar extension to the skull base. Magnetic resonance imaging scan confirmed the expansive tumor without dural penetration. Biopsy revealed no evidence of malignancy and probable neural cell. Bifrontal craniotomy was performed combined with lateral rhinotomy (Weber-Ferguson approach), and the lesion was totally removed. The tumor measured 8.0 4.3 3.7 cm and microscopically appeared as a schwannoma composed of interwoven bundles of elongated cells (Antoni A regions)mixed with less cellular regions (Antoni B). Immunohistochemical study stained intensively for vimentin and S-100. Conclusion Schwannomas of the olfactory groove are extremely rare, and the findings of origin of this tumor is still uncertain but recent studies point most probably to the meningeal branches of trigeminal nerve or anterior ethmoidal nerves. .


Subject(s)
Animals , Female , Male , Mice , Cell Membrane Permeability/physiology , Hair Cells, Auditory/physiology , Ion Channels/physiology , Mechanotransduction, Cellular/physiology , Animals, Newborn , Cadherins/genetics , Cell Membrane Permeability/genetics , Chelating Agents/pharmacology , Dihydrostreptomycin Sulfate/pharmacology , Embryo, Mammalian , Egtazic Acid/analogs & derivatives , Egtazic Acid/pharmacology , Hair Cells, Auditory/cytology , Hair Cells, Auditory/drug effects , In Vitro Techniques , Ion Channels/drug effects , Mice, Transgenic , Mechanotransduction, Cellular/drug effects , Mechanotransduction, Cellular/genetics , Membrane Potentials/drug effects , Membrane Potentials/genetics , Myosins/genetics , Organ of Corti/cytology , Protein Precursors/genetics
8.
Cell Journal [Yakhteh]. 2015; 16 (4): 560-563
in English | IMEMR | ID: emr-154859

ABSTRACT

The effect of external magnetic and electric fields, in the range of electroporation and magnetoporation, on Lucifer Yellow [LY] fluorescence in the absence of cells is studied. Electric-field-induced quenching and magnetic field-induced increase are observed for fluorescence intensity of LY. Regard to the fact that the variation of field-induced fluorescence, even in the absence of cells, can be observed, the application of LY, as a marker, is debatable in electroporation and magnetoporation techniques


Subject(s)
Cell Membrane , Permeability , Cell Membrane Permeability , Magnetic Fields , Electroporation
9.
Acta Pharmaceutica Sinica ; (12): 305-311, 2015.
Article in Chinese | WPRIM | ID: wpr-251779

ABSTRACT

To study the transport mechanisms of drugs for transplacental treatment of fetal tachyarrhythmia, MDCKII-BCRP and MDCKII cell models was used. MDCKII-BCRP and MDCKII cell monolayer model was used to investigate the bi-direction transport of sotalol, propranolol, propafenone, procainamide and flecainide. Drug concentrations were measured by HPLC-UV or chemiluminescence. The apparent permeability coefficient (P(app)), efflux rate (R(E)) and net efflux rate (R(net)) were calculated. Drugs with R(net) greater than 1.5 were further investigated using cellular accumulation experiments with or without a BCRP inhibitor. The R(net) of sotalol, propranolol, propafenone and procainamide were less than 1.5, while R(net) of flecainide with concentrations of 20 and 5 μmol x L(-1) were 1.6 and 1.9, respectively. The results showed that the transport of flecainide on MDCKII-BCRP cell monolayer could be mediated by BCRP; and the affinity increased when the concentration of flecainide decreased. Cellular accumulation experiments further suggested that accumulation of flecainide in MDCKII-BCRP cells was significantly lower than that in MDCKII cells in a concentration-dependent manner. BCRP inhibitor quercetin (50 μmol x L(-1)) significantly increased the accumulation of flecainide in MDCKII-BCRP cells (P < 0.05). Our preliminary data showed that flecainide but not sotalol, propranolol, propafenone or procainamide can be a substrate of BCRP. Thus the effect of flecainide may be affected by the BCRP in the maternal placental trophoblast membrane layer when treating fetal tachyarrhythmia.


Subject(s)
Animals , Biological Transport , Cell Membrane Permeability , Dogs , Female , Flecainide , Metabolism , Madin Darby Canine Kidney Cells , Metabolism , Placenta , Physiology , Pregnancy , Tachycardia , Drug Therapy
10.
Rev. ANACEM (Impresa) ; 8(2): 46-49, dic. 2014. ilus, tab
Article in Spanish | LILACS | ID: biblio-997664

ABSTRACT

INTRODUCCIÓN: El cáncer es una importante causa de mortalidad a nivel mundial, lo que ha motivado la búsqueda de compuestos que ayuden a su remisión, incluyendo compuestos naturales. En este contexto, las sesquiterpén quinonas son evaluadas como posibles sustancias antitumorales por sus propiedades citotóxicas. Una de ellas es Ciclozonarona...


INTRODUCTION: Cancer is a major cause of death in the world, which has motivated the search of compounds that could help to its remission, including natural compound. In this context sesquiterpene quinones are evaluated as possible antitumor substances for its cytotoxic properties, one of them is Ciclozonarone...


Subject(s)
Humans , Male , Prostatic Neoplasms/drug therapy , Sesquiterpenes/pharmacology , Cell Survival/drug effects , Cell Line, Tumor/drug effects , Cell Membrane Permeability/drug effects , Fibroblasts/drug effects , Flow Cytometry , Microscopy, Fluorescence
11.
Rev. bras. cir. cardiovasc ; 29(2): 249-254, Apr-Jun/2014. tab, graf
Article in Portuguese | LILACS | ID: lil-719408

ABSTRACT

O paradoxo do cálcio foi pela primeira vez citado em 1966 por Zimmerman et al. A partir daí, ganhou grande interesse por parte da comunidade científica internacional devido ao fato da ausência do íon cálcio produzir na célula muscular cardíaca dano semelhante à lesão de isquemia-reperfusão. Apesar de não serem conhecidos todos os mecanismos envolvidos no processo da lesão celular no paradoxo do cálcio, a conexão intercelular mantida somente pelo nexus parece ter papel chave na fragmentação celular. A adição de pequenas concentrações de cálcio, bloqueadores de canal de cálcio, hiponatremia ou hipotermia são importantes para evitar que haja lesão celular no momento da reperfusão com soluções com concentração fisiológica de cálcio.


The calcium paradox was first mentioned in 1966 by Zimmerman et al. Thereafter gained great interest from the scientific community due to the fact of the absence of calcium ions in heart muscle cells produce damage similar to ischemia-reperfusion. Although not all known mechanisms involved in cellular injury in the calcium paradox intercellular connection maintained only by nexus seems to have a key role in cellular fragmentation. The addition of small concentrations of calcium, calcium channel blockers, and hyponatraemia hypothermia are important to prevent any cellular damage during reperfusion solutions with physiological concentration of calcium.


Subject(s)
Animals , Humans , Rats , Calcium/metabolism , Heart Injuries/metabolism , Myocytes, Cardiac/metabolism , Adenosine Triphosphate/metabolism , Cell Membrane Permeability , Caffeine/adverse effects , Calcium Channel Blockers/pharmacology , Calcium/administration & dosage , Dinitrophenols/metabolism , Glycocalyx/metabolism , Heart Failure/etiology , Heart Injuries/etiology , Heart Injuries/pathology , Myocardial Reperfusion Injury/metabolism , Myocardium/metabolism , Sodium/physiology , Time Factors
12.
Medicina (B.Aires) ; 74(2): 133-139, abr. 2014. ilus, graf
Article in Spanish | LILACS | ID: lil-708596

ABSTRACT

La fibrosis quística se debe a la ausencia o defecto del canal transmembrana regulador de la fibrosis quística (CFTR), un canal de cloruro codificado en el gen cftr que juega un papel clave en la homeostasis del agua e iones. El CFTR es activado por el AMPc y se localiza en las membranas apicales y basolaterales de las vías aéreas, intestino y glándulas exocrinas. Una de sus funciones primarias en los pulmones es mantener la capa de líquido superficial a través de su función de canal y regular el canal epitelial de sodio sensible al amiloride (ENaC). Se han identificado más de 1900 mutaciones en el gen cftr. La enfermedad se caracteriza por secreciones viscosas en las glándulas exocrinas y por niveles elevados de cloruro de sodio en el sudor. En la fibrosis quística el CFTR no funciona y el ENaC está desregulado; el resultado es un aumento en la reabsorción de sodio y agua con la formación de un líquido viscoso. En las glándulas sudoríparas tanto el Na+ como el Cl- se retienen en el lumen causando una pérdida de electrolitos durante la sudoración y el NaCl se elimina al sudor. Así, los niveles elevados de NaCl son la base del test del sudor inducido por pilocarpina, un método de diagnóstico para la enfermedad. En esta revisión se discuten los movimientos de Cl- y Na+ en las glándulas sudoríparas y pulmón así como el papel del ENaC en la patogénesis de la enfermedad.


Cystic fibrosis is caused by dysfunction or lack of the cystic fibrosis transmembrane conductance regulator (CFTR), a chloride channel that has a key role in maintaining ion and water homoeostasis in different tissues. CFTR is a cyclic AMP-activated Cl- channel found in the apical and basal plasma membrane of airway, intestinal, and exocrine epithelial cells. One of CFTR’s primary roles in the lungs is to maintain homoeostasis of the airway surface liquid layer through its function as a chloride channel and its regulation of the epithelial sodium channel ENaC. More than 1900 CFTR mutations have been identified in the cftr gene. The disease is characterized by viscous secretions of the exocrine glands in multiple organs and elevated levels of sweat sodium chloride. In cystic fibrosis, salt and fluid absorption is prevented by the loss of CFTR and ENaC is not appropriately regulated, resulting in increased fluid and sodium resorption from the airways and formation of a contracted viscous surface liquid layer. In the sweat glands both Na+ and Cl- ions are retained in the lumen, causing significant loss of electrolytes during sweating. Thus, elevated sweat NaCl concentration is the basis of the classic pilocarpine-induced sweat test as a diagnostic feature of the disease. Here we discuss the ion movement of Cl- and Na+ ions in two tissues, sweat glands and in the air surface as well as the role of ENaC in the pathogenesis of cystic fibrosis.


Subject(s)
Humans , Biological Transport/physiology , Cell Membrane Permeability/physiology , Cystic Fibrosis Transmembrane Conductance Regulator/physiology , Cystic Fibrosis/physiopathology , Epithelial Sodium Channels/physiology
13.
Protein & Cell ; (12): 783-794, 2014.
Article in English | WPRIM | ID: wpr-757650

ABSTRACT

Upon glucose elevation, pancreatic beta-cells secrete insulin in a Ca(2+)-dependent manner. In diabetic animal models, different aspects of the calcium signaling pathway in beta-cells are altered, but there is no consensus regarding their relative contributions to the development of beta-cell dysfunction. In this study, we compared the increase in cytosolic Ca(2+) ([Ca(2+)]i) via Ca(2+) influx, Ca(2+) mobilization from endoplasmic reticulum (ER) calcium stores, and the removal of Ca(2+) via multiple mechanisms in beta-cells from both diabetic db/db mice and non-diabetic C57BL/6J mice. We refined our previous quantitative model to describe the slow [Ca(2+)]i recovery after depolarization in beta-cells from db/db mice. According to the model, the activity levels of the two subtypes of the sarco-endoplasmic reticulum Ca(2+)-ATPase (SERCA) pump, SERCA2 and SERCA3, were severely down-regulated in diabetic cells to 65% and 0% of the levels in normal cells. This down-regulation may lead to a reduction in the Ca(2+) concentration in the ER, a compensatory up-regulation of the plasma membrane Na(+)/Ca(2+) exchanger (NCX) and a reduction in depolarization-evoked Ca(2+) influx. As a result, the patterns of glucose-stimulated calcium oscillations were significantly different in db/db diabetic beta-cells compared with normal cells. Overall, quantifying the changes in the calcium signaling pathway in db/db diabetic beta-cells will aid in the development of a disease model that could provide insight into the adaptive transformations of beta-cell function during diabetes development.


Subject(s)
Animals , Calcium , Metabolism , Calcium Signaling , Cell Membrane Permeability , Cells, Cultured , Down-Regulation , Endoplasmic Reticulum , Metabolism , Glucose , Pharmacology , Insulin-Secreting Cells , Cell Biology , Metabolism , Mice , Mice, Inbred C57BL , Mice, Obese , Potassium Chloride , Pharmacology , Sarcoplasmic Reticulum Calcium-Transporting ATPases , Metabolism , Sodium-Calcium Exchanger , Metabolism , Thapsigargin , Pharmacology , Up-Regulation
14.
Acta Pharmaceutica Sinica ; (12): 252-255, 2014.
Article in Chinese | WPRIM | ID: wpr-297984

ABSTRACT

To investigate the influence of the difference enhancers on the transport mechanism of chlorogenic acid (CGA) across Caco-2 cells model, a RP-HPLC method was adopted to detect the concentrations of CGA. At the concentrations of 20 to 80 microg x mL(-1), the difference of absorption rate constants (K(a)) was not statistically significant. At the concentrations of 40 and 20 microg x mL(-1), the ratios of apparent permeability coefficients (P(app)) of the apical to basolateral and the basolateral to apical were 1.14 and 1.18, respectively. With the effect of enhancers K(a) and P(app) increased, the absorption half-life (T1/2) decreased. CGA passed through the Caco-2 cell membrane mainly by passive transport. It showed that monocarboxylic acid transporter (MCT) could be involved in the across membrane transport process of CGA. Borneol had no effect on the cell membrane transport processes. The order of increasing absorption of CGA caused by the enhancers was sodium lauryl sulphate > sodium taurocholate > carbomer.


Subject(s)
Absorption , Acrylic Resins , Pharmacology , Caco-2 Cells , Cell Membrane Permeability , Chlorogenic Acid , Pharmacokinetics , Humans , Sodium Dodecyl Sulfate , Pharmacology , Taurocholic Acid , Pharmacology
15.
Acta Pharmaceutica Sinica ; (12): 1062-1068, 2014.
Article in Chinese | WPRIM | ID: wpr-299166

ABSTRACT

The microstructure of cationic cyclopeptide (TD-34) treated Caco-2 cell membrane was observed, and we discussed the relationship between membrane structure and insulin transmembrane permeability. Atomic force microscope (AFM) was used to observe living cell membrane in air condition and tapping mode. Results showed that the surface of Caco-2 cell membrane treated with TD-34 lost its smoothness and nearly doubled its roughness. Apparent permeability coefficients (P(app)) of insulin in Caco-2 cell monolayers increased 2.5 times. In conclusion, AFM can be used to observe microstructure of cationic cyclopeptide treated cell membrane and cationic cyclopeptide enhanced insulin delivery across Caco-2 cell membrane by increasing membrane fluidity.


Subject(s)
Caco-2 Cells , Cations , Cell Membrane , Cell Membrane Permeability , Humans , Insulin , Metabolism , Membrane Fluidity , Microscopy, Atomic Force , Peptides, Cyclic , Pharmacology
16.
Article in Chinese | WPRIM | ID: wpr-346462

ABSTRACT

<p><b>OBJECTIVE</b>To study the mechanism of the reducing mechanism of hepatotoxicity induced by ethyl acetate fractions of Kansui Radix stir-baked with vinegar in mice.</p><p><b>METHOD</b>Mice with normal ICR were orally administered with ethyl acetate fractions of Kansui Radix and Kansui Radix stir-baked with vinegar. Their blood and liver homogenate were collected to detect the level of AST, ALT, LDH, SOD, activities of Na(+) -K(+) -ATPase and Ca(2+) -Mg(2+) -ATPase, GSH and MDA. Liver tissues were collected for HE staining and morphological observation under light microscope.</p><p><b>RESULT</b>According to the results of pathological sections, compared with the control group, all of Kansui groups showed a significant increase in the hepatic tissues injury (P < 0.01). Compared with Kansui groups, all of vinegar-baked groups showed a significant decrease in the hepatic tissues injury (P < 0.01). Compared with the control group, all of Kansui groups showed a significant increase in ALT, AST and LDH (P < 0.05, P < 0.001) in serum and hepatic tissues, and significantly decrease in the activity of SOD (P < 0.001) and the content of GSH. They also showed a significant increase in MDA (P < 0.001) and a significant decrease in the level of Na(+) -K(+) -ATPase and Ca(2+) -Mg(2+) -ATPase (P < 0.01) in hepatic tissues, with a certain dose-effect relationship. Compared with all of Kansui groups, all of vinegar-baked groups showed a significant decrease in ALT, AST and LDH (P < 0.05, P < 0.001), and a notable increase in SOD (P < 0.001) and GSH in serum and hepatic tissues. They also showed a remarkable decrease in MDA (P < 0.001), and a significant increase in the level of Na(+) -K(+) -ATPase and Ca(2+) - Mg(2+) -ATPase (P < 0.01) in hepatic tissues, with a certain dose-effect relationship.</p><p><b>CONCLUSION</b>Being stir-baked with vinegar can significantly reduce the hepatotoxicity of Kansui Radix. Its mechanism may be related to the reduction of the effect of Kansui Radix on the permeability of hepatic tissues cell membranes and the oxidative injury.</p>


Subject(s)
Acetic Acid , Animals , Cell Membrane Permeability , Euphorbia , Toxicity , Liver , Metabolism , Pathology , Mice , Oxidation-Reduction , Plant Extracts , Toxicity
17.
Article in Chinese | WPRIM | ID: wpr-318640

ABSTRACT

An experiment was carried out to study the allelopathic effects of Coptis chinensis fibrous root extracts (CRE) on the germination and seedling growth of Vicia faba and Pisum sativum in order to alleviate the allelopathic effects and increase land productivity. The seeds of both garden pea (P. sativum) and broad been (V. faba) were germinated in CRE solution of various concentrations, the germination rate, seedling growth and related physiological indexes were measured. The result indicated that there were no significant effects of CRE in low concentrations on seed germination, including both the rate and index, and seed vitality and membrane permeability. With the increment of CRE concentrations, however, the high seed membrane permeability and germination inhibition were observed. For example, the germination rates were reduced by 23.4% (P. sativum) and 9.5% (V. faba), respectively, in CRE solution with 800 mg . L-1. Simultaneously, soluble sugars and the free amino acids in the seeds were lower than those in the control (without CRE) after soaking seeds in CRE solutions. In addition, the seedling growth and nitrate reductase activity were stimulated by CRE at low concentrations in contrast to high concentrations which behaved otherwise and inhibited the nutrient utilization in endosperm. Therefore, the large amount of allelochemicals released from the roots and remains of C. chinensis in soils could inhibit the seed germination and seedling growth of legumes, which may lead to decrease even fail crop yields after growing this medical plant.


Subject(s)
Amino Acids , Metabolism , Cell Membrane Permeability , Coptis , Chemistry , Dose-Response Relationship, Drug , Germination , Nitrate Reductase , Metabolism , Peas , Metabolism , Physiology , Pheromones , Pharmacology , Plant Extracts , Pharmacology , Plant Roots , Chemistry , Seedlings , Vicia faba , Metabolism , Physiology
18.
Article in Chinese | WPRIM | ID: wpr-319408

ABSTRACT

<p><b>OBJECTIVE</b>To explore the appropriate acoustic parameters for augmenting the permeability of tumor cells using microbubble-enhanced ultrasound.</p><p><b>METHODS</b>Ninety intramuscular VX2 tumors grown in New Zealand white rabbits were randomly divided into 4 parts by 4 factors, namely sound intensity, pulse width, insonation time and microbubble dose, each at different levels. Therapeutic ultrasound was delivered directly to the tumor surface during intravenous infusion of microbubbles. The tumor was excised after the treatment and sliced to investigate the change in tumor cell permeability using lanthanum nitrate electron microscopy. The appropriate acoustic parameters of the 4 factors were investigated.</p><p><b>RESULTS</b>Sonoporation induced by microbubble-enhanced ultrasound augmented the permeability of the tumor cells, and the appropriate sound intensity, pulse width, insonation time and microbubble dose were 0.43 W/cm(2), 2.42 ms, 10 min, and 0.50 ml/kg, respectively.</p><p><b>CONCLUSION</b>Sonoporation induced by microbubble-enhanced ultrasound can induce pores in tumor cell membrane, which may potential increase the efficacy of tumor chemotherapy.</p>


Subject(s)
Acoustics , Animals , Cell Line, Tumor , Cell Membrane Permeability , Microbubbles , Neoplasms , Therapeutics , Rabbits , Ultrasonic Therapy , Ultrasonics
19.
Article in Chinese | WPRIM | ID: wpr-235396

ABSTRACT

<p><b>OBJECTIVE</b>To study the synergistic effects of hypothermia and hypoxia on the damage of pulmonary microvascular endothelial cells (PMVEC) in rat.</p><p><b>METHODS</b>Primary PMVECs were obtained by complex phosphoesterasum digesting from isolated lung tissues of Wistar rats, the PMVECs were identified by phase contrast microscope and immunofluorescence studies for CD31 antigen and bandeiraea simplicifolia isolectin (BSI) binding test. Factorial design was adopted in trial according to hypothermia and hypoxia existing or not. Using corresponding kit measured the levels of lactate dehydrogenase (LDH) activity in cell medium. Level of nitric oxide (NO) concentration was measured by Griess Assay. RT-PCR was used to examine the expression of vascular endothelial growth factor (VEGF), endothelin-1 (ET-1) mRNA in PMVECs.</p><p><b>RESULTS</b>The monolayer of cultured PMVECs displayed the shape of pavingstone. CD31 antigen and binding BSI results by fluorescence microscope identified the cultured cells were PMVECs. Compared to the control group, LDH activity and VEGF, ET-1 expression levels were significantly increased in hypothermia group, hypoxia group and hypoxia combined with hypothermia group. And the levels of NO concentration were reduced in these three groups. The results of One-way ANOVA showed that there was a synergistic effect between hypothermia and hypoxia.</p><p><b>CONCLUSION</b>Hypothermia and hypoxia both have an effect on PMVECs whether in altering the cell permeability or in releasing of vasoactive substances including NO and ET-1. In addition, there is a synergistic effect between hypothermia and hypoxia.</p>


Subject(s)
Animals , Cell Hypoxia , Cell Membrane Permeability , Cells, Cultured , Cold Temperature , Endothelial Cells , Cell Biology , Metabolism , Endothelin-1 , Metabolism , Endothelium, Vascular , Cell Biology , Lung , Male , Nitric Oxide , Metabolism , RNA, Messenger , Genetics , Rats , Rats, Wistar , Vascular Endothelial Growth Factor A , Metabolism
20.
Braz. j. microbiol ; 43(3): 984-992, July-Sept. 2012. graf, tab
Article in English | LILACS | ID: lil-656663

ABSTRACT

Pseudomonas aeruginosa is an opportunistic microorganism with the ability to respond to a wide variety of environmental changes, exhibiting a high intrinsic resistance to a number of antimicrobial agents. This low susceptibility to antimicrobial substances is primarily due to the low permeability of its outer membrane, efflux mechanisms and the synthesis of enzymes that promote the degradation of these drugs. Cephalosporins, particularty ceftazidime and cefepime are effective against P. aeruginosa, however, its increasing resistance has limited the usage of these antibiotics. Encapsulating antimicrobial drugs into unilamellar liposomes is an approach that has been investigated in order to overcome microorganism resistance. In this study, antimicrobial activity of liposomal ceftazidime and cefepime against P. aeruginosa ATCC 27853 and P. aeruginosa SPM-1 was compared to that of the free drugs. Liposomal characterization included diameter, encapsulation efficiency and stability. Minimum Inhibitory Concentration (MIC) was determined for free and liposomal forms of both drugs. Minimum Bactericidal Concentration (MBC) was determined at concentrations 1, 2 and 4 times MIC. Average diameter of liposomes was 131.88 nm and encapsulation efficiency for cefepime and ceftazidime were 2.29% end 5.77%, respectively. Improved stability was obtained when liposome formulations were prepared with a 50% molar ratio for cholesterol in relation to the phospholipid. MIC for liposomal antibiotics for both drugs were 50% lower than that of the free drug, demonstrating that liposomal drug delivery systems may contribute to increase the antibacterial activity of these drugs.


Subject(s)
Humans , Anti-Bacterial Agents/analysis , Cell Membrane Permeability , Disease Susceptibility , Drug Resistance, Microbial , In Vitro Techniques , Unilamellar Liposomes/analysis , Unilamellar Liposomes/isolation & purification , Pseudomonas Infections , Pseudomonas aeruginosa/isolation & purification , Environmental Change , Methods , Permeability
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