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1.
Int J Ophthalmol ; 13(3): 390-398, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32309174

RESUMO

AIM: To determine moxonidine in aqueous humor and iris-ciliary body by reversed-phase high performance liquid chromatography (RP-HPLC), and to evaluate the retinal neuroprotective effect after topical administration with moxonidine in a high intraocular pressure (IOP) model. METHODS: The eyes of albino rabbits were administered topically and ipsilaterally with 0.2% moxonidine. A RP-HPLC method was employed for the identification and quantification of moxonidine between 2 and 480min, which presented in the aqueous humor and iris-ciliary body. Flash electroretinography (F-ERG) amplitude and superoxide dismutase (SOD) level were measured between day 1 and day 15 after topical administration with moxonidine in a rabbit model of high IOP. Histological and ultrastructural observation underwent to analyze the changes of retinal morphology, the inner retinal layers (IRL) thickness, and retinal ganglion cell (RGC) counting. RESULTS: Moxonidine was detectable between 2 and 480min after administration, and the peak concentration developed both in the two tissues at 30min, 0.51 µg/mL in aqueous humor and 1.03 µg/g in iris-ciliary body. In comparison to control, F-ERG b-wave amplitude in moxonidine eyes were significantly differences between day 3 and day 15 (P<0.01) in the high IOP model; SOD levels were significantly higher at all time-points (P<0.01) with a maximum level of 20.29 U/mgprot at day 15; and RGCs were significantly higher (P<0.05). CONCLUSION: Moxonidine is a viable neuroprotective agent with application to high IOP model. All layers of retina, including RGC layer, retinal nerve fiber layer and INL, are more preserved after moxonidine administration. SOD plays a neuroprotective role in ocular hypertension-mediated RGC death.

2.
J Pharm Biomed Anal ; 174: 50-56, 2019 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-31153137

RESUMO

Traditional Chinese medicinal materials derived from animal bile are widely applied in clinical therapy for thousands of years in several Southeast Asian countries. Although the constituents are similar, these crude drugs exhibit different pharmacological activities; bile acids are the main bioactive constituent. Depending on the source, the price of these crude drugs differs significantly. Therefore, a reliable fingerprint method is needed to analyze and distinguish these crude drugs with a similar composition. In this milieu, we aimed to establish a fingerprint chromatography method that can separate and detect several bile acids simultaneously. A high-performance liquid chromatography separation method was established with evaporative light scattering detection to detect the analytes. The main bioactive constituents of pig bile, cattle bile, sheep bile, bear bile, and three types of cow bezoar were analyzed using the proposed method. The fingerprint chromatography profile of 35 samples were obtained and analyzed using chemometric methods. Considering the differences among samples, a reference scaleplate method was used in the peak alignment procedure. Unsupervised methods (hierarchical cluster analysis and principle component analysis) and supervised methods (K-nearest neighbor, partial least squares discriminant analysis, support vector machine discriminant analysis, and soft independent modeling of class analogy) were used in the chemometric analysis. The results indicated that the fingerprint chromatograms of the seven crude drugs had fingerprint specificity and that they can be well distinguished. In addition, the reference scaleplate method using the chromatogram of a mixed standard solution is practically applicable for peak alignment in the analysis of samples with a large difference in chromatographic peaks. Overall, 17 bile acids can be separated and detected simultaneously using this method and some frequently used TCMMs derived from animal bile can be distinguished accurately.


Assuntos
Bile/química , Medicamentos de Ervas Chinesas/análise , Animais , Ácidos e Sais Biliares/análise , Bovinos , Cromatografia Líquida de Alta Pressão , Análise Discriminante , Análise dos Mínimos Quadrados , Limite de Detecção , Medicina Tradicional Chinesa , Modelos Estatísticos , Análise de Componente Principal , Controle de Qualidade , Padrões de Referência , Valores de Referência , Reprodutibilidade dos Testes , Ovinos , Máquina de Vetores de Suporte , Suínos
3.
Chin Med J (Engl) ; 124(1): 111-7, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21362318

RESUMO

BACKGROUND: The hairpin cell-penetrating peptides (hCPPs) demonstrate an interesting characteristic of conditioned activation by molecules. We hypothesized that hCPPs have the potential to selectively deliver a paramagnetic gadolinium probe into the matrix metalloproteinase 2 (MMP-2) positive human ovary adenocarcinoma cell lines, SKOV-3. METHODS: hCPPs were synthesized and labeled with 1,4,7,10-tetraazacyclododecane-N,N',N'',N''' tetraacetic acid gadolinium (III) (Gd-DOTA) and fluorescein isothiocyanate (FITC) by f-moc strategy using a standard solid phase peptide synthesis protocol. MMP-2 expression and activity were demonstrated by reverse transcriptase polymerase chain reaction (RT-PCR) and zymography. Internalization and location of hCPPs in SKOV-3 cells were observed by fluorescein imaging and flow cytometery. Selective delivery of Gd-DOTA in SKOV-3 cells was observed by magnetic resonance imaging (MRI) and transmission electron microscopy (TEM). RESULTS: The uptake of hCPPs by SKOV-3 cells depended on the activity of MMP-2. T1WI signals of SKOV-3 cells treated with Gd-DOTA-hCPPs suggested the uptake of Gd-DOTA-hCPPs increased in a time- (r = 0.990, P < 0.01) and concentration-dependent manner (r = 0.964, P < 0.001), but was inhibited by a MMP-2 inhibitor. Electron-dense particles observed in the cytoplasm and nucleus by transmission electron microscopy proved the intracellular penetration of gadolinium. CONCLUSIONS: hCPPs can be used as an effective vector for an MRI molecular probe to assess the activity of MMP-2.


Assuntos
Peptídeos Penetradores de Células/síntese química , Peptídeos Penetradores de Células/metabolismo , Compostos Heterocíclicos/química , Compostos Heterocíclicos/síntese química , Compostos Heterocíclicos/metabolismo , Compostos Organometálicos/química , Compostos Organometálicos/síntese química , Compostos Organometálicos/metabolismo , Linhagem Celular Tumoral , Peptídeos Penetradores de Células/efeitos adversos , Peptídeos Penetradores de Células/química , Citometria de Fluxo , Compostos Heterocíclicos/efeitos adversos , Humanos , Imageamento por Ressonância Magnética , Metaloproteinase 2 da Matriz/química , Metaloproteinase 2 da Matriz/metabolismo , Microscopia Eletrônica de Transmissão , Compostos Organometálicos/efeitos adversos , Reação em Cadeia da Polimerase Via Transcriptase Reversa
4.
J Pharm Anal ; 1(2): 81-91, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-29403684

RESUMO

In China, traditional Chinese medicines (TCMs) have been used in clinical applications for thousands of years. The successful hyphenation of high-Performance liquid chromatography (HPLC) and mass spectrometry (MS) has been applied widely in TCMs and biological samples analysis. Undoubtedly, HPLC/MS technique has facilitated the understanding of the treatment mechanism of TCMs. We reviewed more than 350 published papers within the last 5 years on HPLC/MS in the analysis of TCMs. The present review focused on the applications of HPLC/MS in the component analysis, metabolites analysis, and pharmacokinetics of TCMs etc. 50% of the literature is related to the component analysis of TCMs, which show that this field is the most populär type of research. In the metabolites analysis, HPLC coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry has been demonstrated to be the powerful tool for the characterization of structural features and fragmentation behavior patterns. This paper presented a brief overview of the applications of HPLC/MS in the analysis of TCMs. HPLC/MS in the fingerprint analysis is reviewed elsewhere.

5.
Guang Pu Xue Yu Guang Pu Fen Xi ; 30(5): 1189-91, 2010 May.
Artigo em Chinês | MEDLINE | ID: mdl-20672598

RESUMO

Fourier transform infrared spectroscopy (FTIR) was applied to study the biochemical changes in the radiation damaged mouse thymus which increased with radiation dose and provided a new method for the estimation of the radiation dose of radiation damaged patients. The results demonstrated that with the dose increasing, the peak positions like 1 550, 1 400, 1 400 and 1 640 cm(-1) at the dose of 2, 3 and 5 Gy showed some difference, and there was obvious variance in the intensity: (1) The intensity ratio of 1 085 to 1 236 cm(-1) related to nucleic acid tended to decrease. (2) The intensity ratio of 1 640/1 550 decreased. (3) The intensity at 2 958, 2 925, 1 460 and 1 400 cm(-1) showed no significant difference. The results suggest that it may be possible for FTIR to become an effective method to estimate the radiation dose in clinic.


Assuntos
Doses de Radiação , Espectroscopia de Infravermelho com Transformada de Fourier , Timo/efeitos da radiação , Animais , Camundongos
6.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 45(12): 749-53, 2010 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-21211243

RESUMO

OBJECTIVE: To screen a variety of Porphyromonas gingivalis (Pg) common outer membrane proteins with two-dimensional liquid phase fractionation (PF2D) and matrix-assisted laser desorption ionization time-of-flight/time-of-flight mass spectrometry (MALDI-TOF/TOF-MS) and provide candidate target antigen for the design of vaccines with cross protection against a variety of Pg. METHODS: The outer membrane proteins of Pg301, PgATCC33277 and PgW83 were extracted through ultracentrifugation, and then they were separated by ProteomeLab PF2D protein fractionation system. After separation, the outer membrane proteins were obtained through comparison, and the primary structure of the proteins was identified by MALDI-TOF/TOF-MS and database. RESULTS: Ninety-nine protein samples out of 3 strains of Pg were obtained after the high performance chromato focusing (HPCF) separation process. B7 fractions of 3 strains of Pg were separated by the reversed-phase high performance liquid chromatography (RP-HPCL) separation process. After comparison of peak and retention time of chromatogram, the 8 common protein peaks of 3 strains of Pg were confirmed. The protein samples were identified by MALDI-TOF/TOF-MS, and one of them was known protein arg-gingipain A. CONCLUSIONS: PF2D protein fractionation system is of good reproducibility and high resolution. A combination of PF2D and MALDI-TOF/TOF-MS can be used to identify the common outer membrane proteins of Pg.


Assuntos
Antígenos de Bactérias/análise , Proteínas de Membrana/análise , Porphyromonas gingivalis/imunologia , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Espectrometria de Massas , Reprodutibilidade dos Testes , Vacinas
7.
Zhongguo Zhong Yao Za Zhi ; 33(23): 2834-7, 2008 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-19260325

RESUMO

OBJECTIVE: To develop a HPLC-ESI-MS method for the determination of puerarin and its metabolite and study the metabolic kinetics in beagle dog liver microsomes. METHOD: Beagle dog liver microsomes were prepared by using ultracentrifugation method. Chromatography was performed on a Shimadzu C18 column (2.0 mm x 150 mm, 5 microm). Amethanol-water gradient system was used. ESI interface was applied in the positive, and SIM m/z 417 was puerarin and m/z 531 was daidzein. RESULT: The puerarin was metabolized by NADPH regenerating system in beagle dog microsomes. The Michaelis-Menten parameters Km and Vmax in beagle dog microsomes were initially estimated by analyzing Lineweave-Brurk plot. The Vmax Km of puerarin were (0.047 +/- 0.006) mg x min(-1) x g(-1), (1.22 +/- 0.53) mg x L(-1). CONCLUSION: The puerarin and daidzein can be rapidly determined by HPLC-MS in beagle dog microsomes and the puerarin was metabolized to daidzein by CY P450. The study can give help for Baige capsule.


Assuntos
Isoflavonas/farmacocinética , Fígado/química , Microssomos Hepáticos/química , Animais , Cromatografia Líquida de Alta Pressão , Cães , Fígado/efeitos dos fármacos , Microssomos Hepáticos/efeitos dos fármacos , Farmacocinética , Espectrometria de Massas por Ionização por Electrospray
8.
Yao Xue Xue Bao ; 42(5): 525-8, 2007 May.
Artigo em Chinês | MEDLINE | ID: mdl-17703777

RESUMO

To analyze the constituents in supercritical fluid CO2 extraction (SFE-CO2) of Radix caulophylli, the Radix caulophylli was extracted with SFE-CO2, and analyzed by gas chromatography-mass spectrometry (GC-MS). The GC-MS analysis with a DB-5MS capillary column (30 mm x 0.32 mm ID, 0.25 microm film thickness) was used. The inlet temperature was maintained at 280 degrees C. The column oven was held at 80 degrees C for 2 min, then programmed from 80 to 280 degrees C at 5 degrees C x min(-1) and, finally, held for 4 min. Helium at a constant flow rate of 2.0 mL x min(-1) was used as the carrier gas. The mass spectrometry conditions were as follows: ionization energy, 70 eV; ion source temperature, 200 degrees C. The mass selective detector was operated in the TIC mode (m/z was from 40 - 500). For the first time 49 peaks were separated and identified, the compounds were quantitatively determined by normalization method, and the identified compounds represent 97.44% of total GC peak areas. Viz, n-hexadecanoic acid (31.4%), (E, E) -9, 12-octadecadienoic acid (26.54%), (Z)-7-tetradecenal (9.4%), hexadecenoic acid (3.23%), 10-undecenal (3.22%), octadecanoic acid (2.25%), and caulophylline (1.76%) etc. The results will provide important foundation for understanding the constituents and further exploitation of Radix caulophylli.


Assuntos
Caulophyllum/química , Ácido Palmítico/análise , Dióxido de Carbono , Cromatografia com Fluido Supercrítico , Cromatografia Gasosa-Espectrometria de Massas , Ácido Linoleico/análise , Raízes de Plantas/química , Plantas Medicinais/química
9.
Zhonghua Yi Xue Za Zhi ; 87(4): 233-9, 2007 Jan 23.
Artigo em Chinês | MEDLINE | ID: mdl-17425865

RESUMO

OBJECTIVE: To study invasively imaging MMP2-positive tumor cell by paramagnetic Gadolinium or fluorescein carried by a activable cell penetrating peptides. METHODS: To label Fluorescein-5-isothiocyanate (FITC) and gadopentetate with the activable cell-penetrating peptides by a solid-phase synthesis method. Identification by TOF mass spectrum (TOF-MS). Isoelectric point of the activable cell penetrating peptides is determined by disc electrophoresis. T1 relacion of gadopentetate labeled with the activable cell-penetrating peptides (B) in water were determined on 400 MHZ NMR. Human lung cancer cell lines: A549 were respectively stained by FITC labeled with ACPPs (A) or FITC alone. MMP2 expression and activity were determined by zymography. T1WI signal of A549 incubated with 120 nmol/ml B or Diethylenetriaminepentaacetic Acid-Gadolinium (Gd-DTPA) for different times were obtained by 1.5T MRI. The location of B in A549 was detected by Transmission Electron Microscopy. Visualization analysis and half-quantitative analysis were used to determine the signal characteristics. The ANOVA analysis and the paired samples t test were performed by SPSS 13.0. RESULTS: MALDI TOF-MS molecular weigh of A and B respectively is 3789.74 and 3911.93. Isoelectric point is 11.005T1 Relacion of 0.5 mmol/L Gd-DTPA and B at 17 degrees C respectively is (0.052 +/- 0.01) sec and (0.050 +/- 0.001) sec. Fluorescein uptake assays showed that A translocated into A549 but would be inhibited by MMP2 antibody. Zymography showed both active-MMP2 (67000) and pro-MMP2 (72000) expressed byA549. MR imaging showed A549 incubating with B had a high T(1) signal, and the signal of A549 incubating with Gd-DTPA is similar with that of the control group. Furthermore, ANOVA suggested that the T(1) signal intensity of A549 incubating with B was effected by incubating time (F = 267.569, P < 0.001) and increasing in a time-dependent fashion at the observed time. There is no difference between the T(1) signal intensity of A549 incubating with Gd-DTPA and the control group (P > 0.05). TEM showed A in cytoplasm and nucleus. CONCLUSION: The study in vitro suggests that the MMP-2 activable cell-penetrating peptides bearing contrast media can detect the MMP2-positive tumor cell.


Assuntos
Metaloproteinase 2 da Matriz/metabolismo , Ressonância Magnética Nuclear Biomolecular/métodos , Peptídeos/metabolismo , Biomarcadores Tumorais/química , Biomarcadores Tumorais/metabolismo , Linhagem Celular Tumoral , Meios de Contraste/química , Citoplasma/química , Citoplasma/metabolismo , Citoplasma/ultraestrutura , Citometria de Fluxo , Fluoresceína-5-Isotiocianato/química , Gadolínio DTPA/química , Humanos , Metaloproteinase 2 da Matriz/química , Microscopia Eletrônica de Transmissão , Microscopia de Fluorescência , Peptídeos/síntese química , Peptídeos/química , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
10.
Chin Med J (Engl) ; 120(1): 50-5, 2007 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-17254488

RESUMO

BACKGROUND: The cellular plasma membrane represents a natural barrier to many exogenous molecules including magnetic resonance (MR) contrast agent. Cell penetrating peptide (CPP) is used to internalize proteins, peptides, and radionuclide. This study was undertaken to assess the value of a new intracellular MR contrast medium, CPP labeled diethylenetriamine pentaacetic acid gadolinium (Gd-DTPA) in molecular imaging in vitro. METHODS: Fluorescein-5-isothiocyanate (FITC) and Gd-DTPA respectively labeled with CPP (FITC-CPP, Gd-DTPA-CPP) were synthesized by the solid-phase method. Human hepatic cancer cell line-HepG2 was respectively stained by FITC-CPP and FITC to observe the uptake and intracellular distribution. HepG2 was respectively incubated with 100 nmol/ml Gd-DTPA-CPP for 0, 10, 30, 60 minutes, and imaged by MR for studying the relationship between the incubation time and T(1)WI signal. The cytotoxicity to NIH3T3 fibroblasts cells was measured by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide reduction assay (MTT). RESULTS: The molecular weights of CPP labeled imaging agents, which were determined by MALDI mass spectrometry (FITC-CPP MW = 2163.34, Gd-DTPA-CPP MW = 2285.99), were similar to the calculated molecular weights. Confocal microscopy suggested HepG2 translocated FITC-CPP in cytoplasm and nucleus independent with the incubation temperature. MR images showed HepG2 uptaken Gd-DTPA-CPP had a higher T(1) weighted imaging (T(1)WI) signal, and that the T(1)WI signal intensity was increasing in a time-dependent manner (r = 0.972, P = 0.001), while the signal intensity between the cells incubated by Gd-DTPA for 60 minutes and the controlled cells was not significantly different (P = 0.225). By MTT, all concentrations from 50 nmol/ml to 200 nmol/ml had no significant (F = 0.006, P = 1.000) effect on cell viability of mouse NIH3T3 fibroblasts, compared with the control group. CONCLUSIONS: The newly constructed CPP based on polyarginine can translocate cells by carrying FITC and MR contrast agent Gd-DTPA, and the intracellular concentrations are readily detectable by MR imaging, suggesting a new way for MR molecular imaging.


Assuntos
Meios de Contraste , Gadolínio DTPA , Imageamento por Ressonância Magnética/métodos , Peptídeos/metabolismo , Linhagem Celular Tumoral , Permeabilidade da Membrana Celular , Fluoresceína-5-Isotiocianato , Humanos
11.
Acta Biochim Biophys Sin (Shanghai) ; 38(12): 865-73, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17151780

RESUMO

Tracking the distribution and differentiation of stem cells by high-resolution imaging techniques would have significant clinical and research implications. In this study, a model cell-penetrating peptide was used to carry gadolinium particles for magnetic resonance imaging (MRI) of mesenchymal stem cells (MSCs). MSCs were isolated from rat bone marrow and identified by osteogenic differentiation in vitro. The cell-penetrating peptide labeled with fluorescein-5-isothiocyanate (FITC) and gadolinium was synthesized by a solid-phase peptide synthesis method. Fluorescein imaging analysis confirmed that this new peptide could internalize into the cytoplasm and nucleus at room temperature, 4 degrees and 37 degrees . Gadolinium were efficiently internalized into mesenchymal stem cells by the peptide in a time or concentration-dependent manner, resulting in intercellular shortening of longitudinal relaxation enhancements, which were obviously detected by 1.5 Tesla Magnetic Resonance Imaging. Cytotoxicity assay and flow cytometric analysis showed that the intercellular contrast medium incorporation did not affect cell viability at the tested concentrations. The in vitro experiment results suggested that the new constructed peptides could be a vector for tracking MSCs.


Assuntos
Células da Medula Óssea/citologia , Imageamento por Ressonância Magnética/métodos , Células-Tronco Mesenquimais/citologia , Peptídeos/química , Animais , Apoptose , Células da Medula Óssea/metabolismo , Citometria de Fluxo , Gadolínio/farmacologia , Masculino , Ratos , Ratos Sprague-Dawley , Temperatura , Sais de Tetrazólio/farmacologia , Tiazóis/farmacologia
12.
Hypertension ; 48(4): 724-9, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16966580

RESUMO

Asymmetrical dimethylarginine (ADMA) is an endogenous inhibitor of NO synthase. Because endothelial NO pathway is compromised in patients with salt-sensitive hypertension, we investigated whether the plasma ADMA can be modulated by chronic salt loading in normotensive salt-sensitive persons and its relationship with NO, and we further determined whether or not dietary potassium supplementation can reverse them. Sixty normotensive subjects (aged 20 to 60 years) were selected from a rural community of Northern China. All of the people were sequentially maintained on a low-salt diet for 7 days (3 g/day, NaCl), then a high-salt diet for 7 days (18 g/day), and high-salt diet with potassium supplementation for another 7 days (4.5 g/day, KCl). After salt loading, the plasma ADMA concentrations increased significantly in salt-sensitive subjects (0.89+/-0.02 micromol/L versus 0.51+/-0.02 micromol/L; P<0.05), whereas the plasma NOx levels reduced considerably (41.8+/-2.1 micromol/L versus 63.5+/-2.1 micromol/L; P<0.01). All of the abnormalities normalized when dietary potassium were supplemented (0.52+/-0.03 micromol/L versus 0.89+/-0.02 micromol/L for ADMA and 58.1+/-0.9 micromol/L versus 41.8+/-2.1 micromol/L for NOx). Statistically significant correlations were found among plasma ADMA level, the mean blood pressure, and the level of NO after salt loading in normotensive salt sensitive individuals. Our study indicates that high dietary potassium intake reduces blood pressure and ADMA levels while increasing NO bioactivity in normotensive salt-sensitive but not salt-resistant Asian subjects after salt loading.


Assuntos
Arginina/análogos & derivados , Grupo com Ancestrais do Continente Asiático , Pressão Sanguínea/efeitos dos fármacos , Potássio na Dieta/farmacologia , Cloreto de Sódio na Dieta/administração & dosagem , Adulto , Arginina/sangue , Relação Dose-Resposta a Droga , Resistência a Medicamentos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Nitratos/sangue , Nitratos/urina , Óxido Nítrico/metabolismo , Nitritos/sangue , Nitritos/urina , Concentração Osmolar , Valores de Referência , Cloreto de Sódio na Dieta/farmacologia
13.
Biochem Biophys Res Commun ; 347(1): 133-40, 2006 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-16822478

RESUMO

The ability to track the distribution and differentiation of stem cells by high-resolution imaging techniques would have significant clinical and research implications. In this study, a model cell-penetrating peptide was used to carry gadolinium particles for magnetic resonance imaging of the mesenchymal stem cells. The mesenchymal stem cells were isolated from rat bone marrow by Percoll and identified by osteogenic differentiation in vitro. The cell-penetrating peptides labeled with fluorescein-5-isothiocyanate and gadolinium were synthesized by a solid-phase peptide synthesis method and the relaxivity of cell-penetrating peptide-gadolinium paramagnetic conjugate on 400 MHz nuclear magnetic resonance was 5.7311 +/- 0.0122 m mol(-1) s(-1), higher than that of diethylenetriamine pentaacetic acid gadolinium (p < 0.05). Fluorescein imaging confirmed that this new peptide could internalize into the cytoplasm and nucleus. Gadolinium was efficiently internalized into mesenchymal stem cells by the peptide in a time- or concentration-dependent fashion, resulting in intercellular T1 relaxation enhancement, which was obviously detected by 1.5 T magnetic resonance imaging. Cytotoxicity assay and flow cytometric analysis showed the intercellular contrast medium incorporation did not affect cell viability and membrane potential gradient. The research in vitro suggests that the newly constructed peptides could be a vector for tracking mesenchymal stem cells.


Assuntos
Células da Medula Óssea/citologia , Meios de Contraste , Gadolínio DTPA , Aumento da Imagem/métodos , Imageamento por Ressonância Magnética/métodos , Células-Tronco Mesenquimais/citologia , Peptídeos , Animais , Células Cultivadas , Gadolínio DTPA/química , Magnetismo , Masculino , Tamanho da Partícula , Ratos , Ratos Sprague-Dawley
14.
Yao Xue Xue Bao ; 38(8): 603-8, 2003 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-14628452

RESUMO

AIM: To investigate the differences of pharmacokinetic behavior and tissue distribution of nimodipine and its two enantiomers in rats. METHODS: A high-performance liquid chromatographic method with an ODS column (150 mm x 4.6 mm ID) and a mobile phase of methanol-water (70:30) was used for racemic nimodipine assay. Another method with a Chiralcel OJ column (250 mm x 4.6 mm ID) and a mixture of n-haxane-ethanol (85:15) as mobile phase was used to determine its two enantiomers. Nimodipine was monitored at 236 nm wavelength. RESULTS: The linearity, recoveries and the detection limits of the methods were found to be suitable for the determinations. The average results of within-day and between-day RSDs were 5.64% and 7.85% respectively, the mean recovery was 97.66% for the concentration ranges studied. The pharmacokinetic parameters Tmax, Cmax, AUC and CLs were: S-(-)-nimodipine (2.1 +/- 0.3) h, (197 +/- 5) microgram.L-1, (656 +/- 18) mL.min-1, (0.30 +/- 0.03) microgram.h.L-1, and R-(+)-nimodipine (1.7 +/- 0.5) h, (128 +/- 4) microgram.L-1, (381 +/- 4) mL.min-1, (0.53 +/- 0.03) microgram.h.L-1, respectively. The S-(-)-nimodipine concentration was 2.23 and 1.97 times as high as that of R-(+)-nimodipine in heart and in cerebrum respectively and there was almost only S-(-)-nimodipine in cerebellum. But R-(+)-nimodipine concentration was 1.57, 3.69 and 4.20 times as high as that of S-(-)-nimodipine in major excretion organs such as kidney, spleen and liver respectively. CONCLUSION: The experimental results obtained by using the achiral and chiral liquid chromatography showed that the differences between enantiomers were apparent for the pharmacokinetics in rat plasma, and very significant for the distributions in major target tissues: heart, cerebrum and cerebellum, and main elimination tissues: kidney, spleen and liver.


Assuntos
Bloqueadores dos Canais de Cálcio/farmacocinética , Nimodipina/farmacocinética , Animais , Área Sob a Curva , Bloqueadores dos Canais de Cálcio/sangue , Bloqueadores dos Canais de Cálcio/química , Cromatografia Líquida de Alta Pressão/métodos , Feminino , Masculino , Nimodipina/sangue , Nimodipina/química , Ratos , Estereoisomerismo , Distribuição Tecidual
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