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1.
Zhonghua Yan Ke Za Zhi ; 60(6): 518-527, 2024 Jun 11.
Artigo em Chinês | MEDLINE | ID: mdl-38825951

RESUMO

Objective: To explore the differences in metabolites and metabolic pathways in the aqueous humor between patients with presenile cataracts and senile cataracts. Methods: This metabolomic study was conducted at Tianjin Medical University Eye Hospital from August 2020 to September 2022. Eight patients with presenile cataracts (8 eyes) and 8 patients with senile cataracts (9 eyes) were included. Data were collected, including age, gender, preoperative uncorrected visual acuity, intraocular pressure, lens dysfunction index, and axial length. Aqueous humor and anterior capsule tissue samples were obtained during cataract surgery. Metabolites in the aqueous humor were detected using Liquid Chromatography-Mass Spectrometry in a non-targeted approach. The principal component analysis, differential analysis, clustering analysis, and correlation analysis were performed to identify differentially expressed metabolites. These metabolites were ranked based on the fold change (FC). The receiver operating characteristic (ROC) curve analysis and metabolic enrichment analysis were used to identify differential pathways and potential biomarkers for presenile cataracts. Immunohistochemistry was conducted on anterior capsule tissues, and pyruvate levels were measured by colorimetry to validate metabolomic results. Results: Patients with presenile cataracts included 7 males and 1 female, with a mean age of (37.50±4.90) years. Patients with senile cataracts were 7 males and 1 female, with a mean age of (73.44±5.22) years. Except for age, there were no significant differences in baseline data (P>0.05). A total of 347 differential metabolites were identified, 10 of which were potential biomarkers for presenile cataract according to the ROC curve analysis (all P<0.05), including propoxycaine (log2FC=7.26), 2-methyl-2, 3, 4, 5-tetrahydro-1, 5-benzodiazepine-4-ketone (log2FC=6.35), l-pyroglutamic acid (log2FC=-1.72), leanly-proline (log2FC=-0.77), and choline (log2FC=-0.56) in the positive ion mode, and N-phenylacetyl glutamine (log2FC=-1.84), pyruvate (log2FC=1.07), ascorbic acid (log2FC=0.92), pseudouracil nucleoside (log2FC=-0.68), and palmitic acid (log2FC=-0.51) in the negative ion mode. The metabolic enrichment analysis identified 72 differential pathways (32 cationic and 40 anionic), with significant differences in glutathione metabolism, cysteine and methionine metabolism, glycolysis or gluconeogenesis, pyruvate metabolism, and the citric acid cycle (P<0.05). The experimental validation showed reduced lactate dehydrogenase and increased pyruvate levels in patients with presenile cataracts (P<0.05). Conclusions: Pyruvate and nine other metabolites may serve as potential biomarkers for presenile cataracts. Pathways involving glutathione metabolism, cysteine and methionine metabolism, glycolysis or gluconeogenesis, pyruvate metabolism, and the citric acid cycle are notably dysregulated in patients with presenile cataracts.


Assuntos
Humor Aquoso , Catarata , Metabolômica , Humanos , Catarata/metabolismo , Humor Aquoso/metabolismo , Metabolômica/métodos , Biomarcadores/metabolismo , Masculino , Feminino
2.
Phys Chem Chem Phys ; 21(29): 16108-16119, 2019 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-31290876

RESUMO

Cadmium selenide (CdSe) nanocrystals are important photoelectric materials. Doping heterovalent impurities such as silver (Ag) in CdSe nanocrystal quantum dots (QDs) can provide additional charge carriers, which can significantly enhance the performance of CdSe QDs for their potential applications in high-efficiency photovoltaic devices. Using density functional theory (DFT) based calculations with the Heyd-Scuseria-Ernzerhof (HSE06) screened hybrid functional, we demonstrate that Ag doping can affect the structural, electronic and optical properties of CdSe QDs significantly. The location and number of Ag dopant atoms are critical factors for modifying the electronic structure, in particular the change of energy position and shape of the valence and conduction band edges. It is found that doping of Ag atoms into the core region of a CdSe nanoparticle induces metallic-like electronic characteristics with a dense number of electrons emerging at the Fermi level. However, incorporation of Ag dopant into the surface of a CdSe quantum dot introduces some mid-gap states that mainly consist of Se 4p states, and results in a new sub-bandgap electronic transition from mid-gap states to the conduction band. The calculated absorption spectra indicate that doping of just one or two Ag atoms greatly strengthens the absorption in the ultraviolet-visible regime and extends the absorption edges of CdSe QDs into the infrared regime. In particular, the spectra show a high-intensity absorption band between 424 and 600 nm with just 1 Ag atom incorporated into the CdSe QDs. Based on the improved absorption spectra, the present results provide a science-based strategy for designing Ag-doped CdSe QDs with enhanced visible light absorption for their application in high-efficiency photovoltaic devices.

3.
Zhonghua Er Ke Za Zhi ; 55(1): 30-36, 2017 Jan 02.
Artigo em Chinês | MEDLINE | ID: mdl-28072956

RESUMO

Objective: To investigate the clinical and immunological laboratory features and gene mutation in a female patient who carried a germline gain-of-function mutation in STAT3. Method: A patient with lymphadenopathy and pancytopenia, visited the Department of Rheumatology and Immunology of Children's Hospital of Chongqing Medical University in May 2016. The clinical and laboratory characteristics, results of immunophenotyping and exome sequencing were analyzed retrospectively and related literature was reviewed. Result: The patient was a four years old girl. The clinical manifestation consisted of autoimmune pancytopenia, lymphadenopathy and recurrent infections. Multiple exams showed that peripheral blood leukocyte count was (2.2-4.9)×109/L, red blood cell count was (2.09-5.75)×109/L, hemoglobin level was 64-165 g/L, platelet count was (52-138) ×109/L. Percentages of lymphocyte subsets showed that CD3+ T lymphocyte was 0.716 0 (CD4+ T lymphocyte was 0.326 0, CD8+ T lymphocyte was 0.323 0 and CD4- CD8-T TCRαß+ lymphocyte was 0.029 0), CD19+ B lymphocyte was 0.235 0 (transitional B was 0.004 3), NK was 0.032 0. Percentages of CD4+ T lymphocyte release IL-4, IFN-γ, IL-17 and IL-21 were 0.014 9, 0.213, 0.024 0 and 0.021 0, respectively. Lymphocyte proliferation function and TCRVß diversity were normal. The serum immunoglobulin levels were 16.4 g/L (IgG), 1.53 g/L (IgA), 3.99 g/L (IgM) and 3.20 kU/L (IgE). The patient carried a missense variant in the 21st exon of STAT3, c. 1974G>C, p.K658N, which was previously described as a gain-of-function mutation. The patient was treated with methylprednisolone and prednisone intermittently. There were significant improvements of hepatosplenomegaly, lymphadenopathy and pancytopenia. We searched internal database and literature for cases with gain-of-function mutations in STAT3. A total of 19 cases were identified, all were non-Chinese. Among 16 cases who had clinical data, age of onset of 11 patients was less than 5 years. 14 cases had autoimmune hemolytic anemia, autoimmune thrombocytopenia or autoimmune neutropenia. Twelve patients had lymphadenopathy while 11 had infections and 5 had endocrine abnormalities. Conclusion: The patient with Primary immunodeficiency disease (PID) due to gain-of-function mutation in STAT3 gene often has early-onset autoimmune disorders, lymphadenopathy and recurrent infections. Since the routine immunological examination may be normal or slightly abnormal, comprehensive evaluation of immune function should be done. Genetic testing ultimately helps to confirm the diagnosis.


Assuntos
Autoimunidade , Mutação , Fator de Transcrição STAT3/genética , Linfócitos B , Linfócitos T CD4-Positivos , Linfócitos T CD8-Positivos , Pré-Escolar , Feminino , Humanos , Imunofenotipagem , Interleucina-17 , Interleucina-4 , Interleucinas , Contagem de Linfócitos , Subpopulações de Linfócitos , Contagem de Plaquetas , Estudos Retrospectivos
4.
J Mol Endocrinol ; 51(1): 27-35, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23549406

RESUMO

Obesity is currently a worldwide pandemic. Leptin resistance is a main mechanism of obese human and rodents. The downregulation of the long form of the leptin receptor (Lrb) was involved in leptin resistance in diet-induced obese rats. In the studies, we investigated whether arcuate nucleus (ARC) silencing of Lrb would promote diet-induced obesity in rats. Lentiviral vectors expressing Lrb-shRNA were administered to 5-week-old male rats by ARC injection. Following viral delivery, the rats were provided with a high-fat diet (HFD) or a chow diet (CD). After 8 weeks of the diet, serum leptin, and insulin concentrations were measured by RIA, gene expression of Lrb in the ARC was detected by a real-time RT-PCR, and leptin signaling was examined by western blot. The Lrb-shRNA knocked down the expression of Lrb mRNA in infected regions by 54% for the HFD rats and 47% for the CD rats respectively. The Lrb knockdown reduced Stats3 activation and increased expression of Npy mRNA. The rats with reduced Lrb in the ARC showed a significant increase in energy intake and body weight (BW) again when fed with a HFD. By contrast, there were no effects of Lrb reduction on energy intake or BW when rats maintained on a low-fat chow. Our results provide evidence that Lrb knockdown selectively in the ARC promotes diet-induced obesity and associated metabolic complications in rats.


Assuntos
Núcleo Arqueado do Hipotálamo/metabolismo , Dieta Hiperlipídica , Obesidade/etiologia , Receptores para Leptina/genética , Animais , Modelos Animais de Doenças , Regulação da Expressão Gênica , Técnicas de Silenciamento de Genes , Vetores Genéticos/genética , Lentivirus/genética , Leptina/metabolismo , Masculino , Neuropeptídeo Y/genética , Neuropeptídeo Y/metabolismo , Obesidade/genética , Obesidade/metabolismo , Interferência de RNA , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Ratos , Transdução de Sinais , Proteína 3 Supressora da Sinalização de Citocinas , Proteínas Supressoras da Sinalização de Citocina/metabolismo
5.
J Anim Physiol Anim Nutr (Berl) ; 96(6): 955-61, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21848849

RESUMO

The current study was carried out to determine the effects of alpha-lipoic acid (LA) supplementation during late-gestation and lactation on antioxidative ability and performance of sows and their nursing piglets. A total of 160 multiparous sows were randomly allocated to four treatments with 40 replicates per treatment according to parity number and backfat (BF) thickness. Sows were fed 1 of 4 diets from day 85 of gestation to day 21 of lactation. Diets were control without LA; 400 ppm LA supplementation; 600 ppm LA supplementation; and 800 ppm LA supplementation. BF thickness of sows was determined on day 85 and 110 of gestation and days 1 and 21 of lactation. Piglet bodyweight was measured at birth, days 7, 14 and 21. Blood samples were obtained from the sows, and average daily feed intake (ADFI) of the sows during lactation was recorded. There were no differences in BF thickness or ADFI among treatment groups. Dietary LA supplementation resulted in a decrease in blood urea nitrogen (p < 0.01) concentration at days 110 of gestation. Dietary 800 ppm LA increased serum glutathione peroxidase (GSH-Px) activity (p < 0.05) and reduced maleic dialdehyde levels (p < 0.01) of sows compared with the control diet at days 21 of lactation. Alpha-lipoic acid supplementation increased the birthweight and weaning weight of piglets (p < 0.01) compared with the control group. Weight gains of piglets from sows fed the 800 ppm LA diets were greater (p < 0.01) between days 7 and 14 compared with piglets from control sows. Weight gains of piglets from sows fed the LA-supplemented diets were greater between days 14 and 21 (p < 0.05) and between days 1 and 21 (p < 0.01) compared with piglets from control-fed sows. In conclusion, the results indicate that antioxidant LA was effective in enhancing antioxidant enzymes activity and improving the performance of sows and their nursing piglets.


Assuntos
Animais Lactentes/crescimento & desenvolvimento , Antioxidantes/metabolismo , Suplementos Nutricionais , Suínos/crescimento & desenvolvimento , Ácido Tióctico/farmacologia , Ração Animal , Fenômenos Fisiológicos da Nutrição Animal , Animais , Dieta/veterinária , Feminino , Fenômenos Fisiológicos da Nutrição Materna , Gravidez , Ácido Tióctico/administração & dosagem
6.
J Appl Microbiol ; 110(1): 147-55, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21040271

RESUMO

AIMS: To prepare, purify and characterize an extracellular enzyme from Myxococcus fulvus ANSM068, designated as myxobacteria aflatoxin degradation enzyme (MADE), which possesses degradation activity against aflatoxin B(1) (AFB(1) ), G(1) (AFG(1) ) and M(1) (AFM(1) ) in solution. METHODS AND RESULTS: The culture supernatant of strain M. fulvus demonstrated high degradation ability against AFB(1) (71·89%), AFG(1) (68·13%) and AFM(1) (63·82%) after 48 h of incubation. An enzyme was purified from the supernatant of M. fulvus using ethanol precipitation and chromatography on DEAE-Sepharose and Superdex 75. An overall 166-fold purification of the enzyme with a recovery of 57% and a final specific activity of 569·44 × 10(3) U mg(-1) was obtained using the present purification protocol. The apparent molecular mass of MADE was estimated to be 32 kDa by SDS-PAGE. AFG(1) and AFM(1) were significantly degraded, by 96·96 and 95·80%, respectively, when treated with pure MADE (100 U ml(-1) ) produced by strain ANSM068. MADE exhibited the largest amount of activity at 35°C and pH 6·0, with Mg(2+) ions greatly promoting and Zn(2+) strongly inhibiting MADE activity. CONCLUSIONS: An aflatoxin DEGRADATION ENZYME FROM BACTERIAL ISOLATES CAN EFFECTIVELY REMOVE AFLATOXIN B(1) , G(1) AND M(1) IN SOLUTION. SIGNIFICANCE AND IMPACT OF THE STUDY: The high activity and wide temperature and pH range of MADE for the degradation of aflatoxin have promising applications in control of mycotoxins during food and feed processing.


Assuntos
Aflatoxinas/metabolismo , Myxococcus/enzimologia , Aflatoxina B1/metabolismo , Aflatoxina M1/metabolismo , Proteínas de Bactérias/isolamento & purificação , Proteínas de Bactérias/metabolismo
7.
J Histochem Cytochem ; 42(8): 1043-54, 1994 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-8027524

RESUMO

Heparan sulfate accumulates on cell surfaces and at cell-matrix interfaces, and functionally modulates several of the effector molecules that support the interactions, growth, and differentiation of developing tissues. Using heparin sulfate-specific monoclonal antibodies MAb, we obtained evidence that extracts from rodent embryos contain multiple forms of cell surface-associated heparan sulfate proteoglycan (PG). Taking tooth development in the mouse embryo as a model to further investigate the relevance of this PG redundancy and using MAb against heparan sulfate, antibodies specific for syndecan (syndecan-1) and fibroglycan (syndecan-2) (two distinct members of a larger family of cell-surface heparan sulfate PGs), and specific cDNA probes for these two cell-surface PGs, we obtained in situ evidence for regulated and differential expression of multiple cell-surface heparan sulfate PGs. The unique, distinctive, and coordinated changes in the expressions of these PGs during morphogenesis and differentiation of dental tissues suggest that the various cell-surface PGs are not truly redundant but play important, specific, and potentially complementary roles during embryonic development.


Assuntos
Heparitina Sulfato/metabolismo , Glicoproteínas de Membrana/metabolismo , Odontogênese/fisiologia , Proteoglicanas/metabolismo , Dente/embriologia , Animais , Anticorpos Monoclonais , Northern Blotting , Western Blotting , Membrana Celular/metabolismo , Cricetinae , Eletroforese em Gel de Poliacrilamida , Imuno-Histoquímica , Hibridização In Situ , Mesocricetus/embriologia , Camundongos/embriologia
8.
Contraception ; 49(3): 245-53, 1994 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-8200218

RESUMO

The present study was designed to examine the effect RU 486 administration on steroid hormone levels in serum and decidua. Sixty women at 6-7 weeks gestation were divided into three groups. The first group took a placebo 24 hours before interruption of pregnancy. The other two groups took 200 mg mifepristone 12 and 24 hours before the surgical procedure, respectively. The concentrations of steroids and mifepristone were measured by radioimmunoassay or high performance liquid chromatography. Mifepristone treatment increased the levels of estradiol, cortisol and testosterone in serum and decidual cytosol (p < 0.05 or p < 0.01). A minor elevation in progesterone level was observed but was not statistically significant. The tissue levels of progesterone, estradiol and testosterone were much higher than the serum levels, whereas RU 486 concentration in the tissue was only one-third of the serum level. In addition, the RU 486 level in decidual cytosol was of the same order as that of progesterone. This competitive concentration was not achieved in chorionic villi in our previous observation, explaining why mifepristone exerts its predominant effect on decidua rather than villi. It is concluded that RU 486 reached an effective inhibitory concentration in decidua and had significant effects on the endocrine milieu.


Assuntos
Estradiol/metabolismo , Hidrocortisona/metabolismo , Mifepristona/metabolismo , Mifepristona/farmacologia , Progesterona/metabolismo , Testosterona/metabolismo , Aborto Induzido , Adulto , Cromatografia Líquida de Alta Pressão , Citosol/metabolismo , Decídua/efeitos dos fármacos , Decídua/metabolismo , Estradiol/sangue , Feminino , Humanos , Hidrocortisona/sangue , Mifepristona/administração & dosagem , Mifepristona/sangue , Gravidez , Progesterona/sangue , Radioimunoensaio , Testosterona/sangue
9.
Development ; 119(3): 841-54, 1993 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-8187643

RESUMO

Fibroglycan (syndecan-2) is a member of a family of cell surface heparan sulfate proteoglycans that interact with adhesion molecules, growth factors and a variety of other effector systems that support the shaping, maintenance and repair of an organism. To investigate this apparent redundancy of proteoglycans at the cell surface, we have studied the expression of fibroglycan in the mouse embryo and compared this expression with that of syndecan-1. The characterisation of mouse embryo cDNA clones that crosshybridized to human fibroglycan-cDNA predicted that murine and human fibroglycan were highly similar in structure. Consistently, the analysis of transfectant cells, murine cell lines and embryo extracts indicated that the murine proteoglycan reacted specifically with monoclonal antibody 10H4 developed against the human protein. Fibroglycan, as detected by monoclonal antibody 10H4 in sections of embryonic tissues, occurred exclusively on mesenchymal cells that represented the putative precursors of the hard and connective tissue cells. No fibroglycan was detected in epithelia or in muscle cells. Areas where fibroglycan was particularly abundant were sites of high morphogenetic activity where intense cell-cell and cell-matrix interactions are known to occur (e.g. the epithelial-mesenchymal interfaces, the prechondrogenic and preosteogenic mesenchymal condensations). The expression of fibroglycan was weak in the early embryo, culminated during the morphogenetic phase and at the moment of cell lineage differentiation, and persisted in the perichondrium, periosteum and connective tissue cells. Syndecan-1, in contrast, was primarily detected in epithelia, and transiently in some mesenchymal cells, with mesenchymal localisations that did not or only partially overlap with those of fibroglycan. In situ hybridization analyses confirmed these expression patterns at the transcriptional level, identifying mesenchymal cells as the major source of fibroglycan production. These data indicate that the expression of fibroglycan occurs along unique and developmentally regulated patterns, and suggest that fibroglycan and syndecan-1 may have distinctive functions during tissue morphogenesis and differentiation.


Assuntos
Embrião de Mamíferos/fisiologia , Glicoproteínas de Membrana/genética , Mesoderma/fisiologia , Proteoglicanas/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Expressão Gênica/fisiologia , Humanos , Imuno-Histoquímica , Hibridização In Situ , Camundongos , Camundongos Endogâmicos , Dados de Sequência Molecular , Morfogênese/genética , Ratos , Homologia de Sequência de Aminoácidos , Sindecana-1 , Sindecana-2 , Sindecanas
10.
J Cell Biol ; 119(4): 961-75, 1992 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-1385449

RESUMO

Two mAbs that are specific for heparan sulfate-related epitopes have been raised and used to analyze the cellular and tissular distribution of this glycosaminoglycan during development. mAb 10E4 reacts with an epitope that occurs in native heparan sulfate chains and that is destroyed by N-desulfation of the glycosaminoglycan. The antibody does not react with hyaluronate, chondroitin sulfate, or DNA, and reacts only poorly with heparin. The reactivity of proteoglycan extracts or tissue sections with the 10E4 antibody is completely abolished by heparitinase, but is only partially affected by heparinase. mAb 3G10, in contrast, reacts only with heparitinase-treated heparan sulfate chains, proteoglycans, or tissue sections. The 3G10 epitope is destroyed by treatment with mercuric acetate, which indicates that the desaturated uronate generated by the lyase is essential for the reactivity of the antibody. The 3G10 epitope is not generated by treating heparan sulfate proteoglycans with heparinase or chondroitin sulfate proteoglycans with chondroitin sulfate lyases, which indicates that the 3G10 antibody recognizes desaturated uronates that occur in specific structural contexts. The antibody 10E4 and, after heparitinase treatment, the antibody 3G10 decorate the surfaces of many cell types and the extracellular matrix in proximity of the cells, in particular, the basement membranes. The analysis of embryonic and adult tissues reveals important temporal and regional differences in the abundance of the 10E4 and 3G10 epitopes at these sites. Moreover, the staining pattern of the two antibodies is not always superimposable, which is indicative of regional differences in the exposure or structure of the tissular heparan sulfates. As a whole the results suggest that heparan sulfate abounds at sites of active morphogenesis and that the expression of this glycosaminoglycan is developmentally regulated.


Assuntos
Desenvolvimento Embrionário e Fetal , Heparitina Sulfato/biossíntese , Animais , Anticorpos Monoclonais , Especificidade de Anticorpos , Células Cultivadas , Sistema Nervoso Central/química , Sistema Nervoso Central/embriologia , Cricetinae , Epitélio/química , Epitopos , Heparitina Sulfato/análise , Heparitina Sulfato/imunologia , Humanos , Hibridomas , Concentração de Íons de Hidrogênio , Técnicas Imunoenzimáticas , Mesoderma/química , Polissacarídeo-Liases/metabolismo , Cloreto de Sódio/farmacologia
11.
Zhongguo Yao Li Xue Bao ; 13(5): 467-70, 1992 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-1300055

RESUMO

Epostane (Epo), a 3 beta-hydroxysteroid dehydrogenase inhibitor, interrupted pregnancy in rats, rhesus monkeys, and women. Epo concentrations in serum were determined by high performance liquid chromatography (HPLC) at 0.25, 0.5, 1, 2, 4, 8, 16, 32, and 48 h after intragastric Epo 96 mg.kg-1 in rabbits. The concentration-time curve exhibited a 2-compartment open model. The pharmacokinetic parameters were: T1/2ka 0.79 +/- 0.08 h, T1/2 alpha 0.96 +/- 0.08 h, T1/2 beta 6.6 +/- 1.5 h, Vc 14 +/- 3 ml.kg-1, AUC 12.0 +/- 1.9 micrograms.h.ml-1, Tmax 1.8 +/- 0.5 h, Cmax 3.3 +/- 0.5 microgram.ml-1. After rat copora luteum were incubated with hCG 10 IU.ml-1 and Epo 10 or 100 micrograms.ml-1 for 18 and 48 h, luteal cells showed various degrees of degeneration and progesterone production was significantly inhibited.


Assuntos
Androstenóis/farmacocinética , Animais , Cromatografia Líquida de Alta Pressão , Corpo Lúteo/metabolismo , Feminino , Técnicas In Vitro , Masculino , Gravidez , Progesterona/biossíntese , Coelhos , Ratos , Ratos Sprague-Dawley
12.
Shengzhi Yu Biyun ; 12(3): 7-10, 1992 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-12317566

RESUMO

PIP: Drug release from Chinese subcutaneous implants containing levonorgestrel was studied. It was compared with that of Norplant. A horizontal vibration method was applied in this experiment, all conditions in keeping with the requirements of the "sink condition." The daily release of levonorgestrel in vitro was assayed by measuring the UV absorption of the solution at 240 nm. The results from 2 years of release experiments in vitro showed that the release rate of levonorgestrel from the Chinese implant was constant with good reproducibility, and no bursting effect could be seen. The Chinese implants release levonorgestrel with order and the average daily release was 85 mcg. Norplant had a 10 day bursting effect before the release rate became constant. The daily release of levonorgestrel was 68 mcg. (author's modified)^ieng


Assuntos
Levanogestrel , Projetos de Pesquisa , Ásia , China , Anticoncepção , Anticoncepcionais , Anticoncepcionais Femininos , Países em Desenvolvimento , Serviços de Planejamento Familiar , Ásia Oriental , Técnicas In Vitro , Pesquisa
13.
J Biomech Eng ; 113(4): 423-9, 1991 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-1762440

RESUMO

The self-heated thermistor technique was used to measure the thermal conductivity and thermal diffusivity of biomaterials at low temperatures. Thermal standards were selected to calibrate the system at temperatures from -10 degrees C to -70 degrees C. The thermal probes were constructed with a convection barrier which eliminates convection inside liquid samples of low viscosity, without affecting the conductivity and diffusivity results. Using this technique, the thermal conductivity and diffusivity of two organ perfusates (HP5 and HP5 + 2M glycerol), one kidney phantom (a low ionic strength gel), as well as rabbit kidney cortex have been measured from -10 degrees C to -70 degrees C.


Assuntos
Criopreservação , Crioprotetores , Rim/fisiologia , Teste de Materiais , Condutividade Térmica , Termografia/instrumentação , Animais , Materiais Biocompatíveis , Calibragem , Difusão , Desenho de Equipamento , Feminino , Técnicas In Vitro , Masculino , Modelos Estruturais , Perfusão , Coelhos , Viscosidade
14.
Shengzhi Yu Biyun ; 11(1): 26-31, 1991 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-12343816

RESUMO

PIP: The plasma concentration of RU486 and its metabolites were studied to achieve a systematic comparison of different dosages, and to investigate the pharmacokinetics of different dosages in order to determine the optimum dosage and means of administration of RU486 in clinical applications. Nine healthy women aged 22 to 35 were recruited for the study. RU486 was given orally before menstruation for 5 consecutive months in increasing dosages of 25, 100, 200, 400. and 600 mg, respectively. Blood samples were drawn 12 times at 1/3 to 120 hours following each drug administration. The HPLC method was used in the analysis, and a 200 mm x 3.5 mm ODS/YWG column was used. The mobile phase was methanol: acetonitrile: water 42:28:30 (V:V:V). The Ph level was 4.7, and the flow rate was 1 ml/min. An ultra-violet detector was used for monitoring at 302 nm. Under these chromatographic conditions, RU486 and its metabolites were well separated. The plasma concentration of the four compounds were linear over the range of 100-2800 ng/ml. Their linear correlation coefficients were all 0.999. The recovery of different concentrations of RU486, Ru42633, and RU42698 was 90% and that of RU42848 was 60%. The HPLC chromatographic conditions and the procedures used for blood sample analysis provided a reliable method to test separation and measurement of RU486 and its metabolites in blood sample for pharmacokinetic research. The separation of RU486 and its metabolites differs in different Ph mobile phases. A Ph level of 4.7 seems to lead to optimum separation.^ieng


Assuntos
Abortivos , Experimentação Humana , Metabolismo , Mifepristona , Aborto Induzido , Ásia , Biologia , China , Países em Desenvolvimento , Sistema Endócrino , Serviços de Planejamento Familiar , Ásia Oriental , Antagonistas de Hormônios , Hormônios , Fisiologia , Pesquisa
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