Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 11 de 11
Filtrar
Más filtros













Base de datos
Intervalo de año de publicación
1.
Nat Commun ; 14(1): 2573, 2023 05 04.
Artículo en Inglés | MEDLINE | ID: mdl-37142604

RESUMEN

Non-alcoholic fatty liver disease (NAFLD) is the most common liver disease in the world. High levels of free fatty acids in the liver impair hepatic lysosomal acidification and reduce autophagic flux. We investigate whether restoration of lysosomal function in NAFLD recovers autophagic flux, mitochondrial function, and insulin sensitivity. Here, we report the synthesis of novel biodegradable acid-activated acidifying nanoparticles (acNPs) as a lysosome targeting treatment to restore lysosomal acidity and autophagy. The acNPs, composed of fluorinated polyesters, remain inactive at plasma pH, and only become activated in lysosomes after endocytosis. Specifically, they degrade at pH of ~6 characteristic of dysfunctional lysosomes, to further acidify and enhance the function of lysosomes. In established in vivo high fat diet mouse models of NAFLD, re-acidification of lysosomes via acNP treatment restores autophagy and mitochondria function to lean, healthy levels. This restoration, concurrent with reversal of fasting hyperglycemia and hepatic steatosis, indicates the potential use of acNPs as a first-in-kind therapeutic for NAFLD.


Asunto(s)
Enfermedad del Hígado Graso no Alcohólico , Ratones , Animales , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Autofagia , Hígado/metabolismo , Lisosomas/metabolismo , Concentración de Iones de Hidrógeno
2.
Nat Commun ; 13(1): 4661, 2022 08 09.
Artículo en Inglés | MEDLINE | ID: mdl-35945224

RESUMEN

ß-Glucans are of significant interest due to their potent antitumor and immunomodulatory activities. Nevertheless, the difficulty in purification, structural heterogenicity, and limited solubility impede the development of structure-property relationships and translation to therapeutic applications. Here, we report the synthesis of a new class of (1→6)-ß-glucose-branched poly-amido-saccharides (PASs) as ß-glucan mimetics by ring-opening polymerization of a gentiobiose-based disaccharide ß-lactam and its copolymerization with a glucose-based ß-lactam, followed by post-polymerization deprotection. The molecular weight (Mn) and frequency of branching (FB) of PASs is readily tuned by adjusting monomer-to-initiator ratio and mole fraction of gentiobiose-lactam in copolymerization. Branched PASs stimulate mouse macrophages, and enhance production of pro-inflammatory cytokines in a FB-, dose-, and Mn-dependent manner. The stimulation proceeds via the activation of NF-κB/AP-1 pathway in a Dectin-1-dependent manner, similar to natural ß-glucans. The lead PAS significantly polarizes primary human macrophages towards M1 phenotype compared to other ß-glucans such as lentinan, laminarin, and curdlan.


Asunto(s)
Glucosa , beta-Glucanos , Animales , Glucosa/metabolismo , Humanos , Macrófagos/metabolismo , Ratones , FN-kappa B/metabolismo , beta-Glucanos/metabolismo , beta-Lactamas/metabolismo
3.
Chem Sci ; 12(38): 12719-12725, 2021 Oct 06.
Artículo en Inglés | MEDLINE | ID: mdl-34703558

RESUMEN

Anticoagulant therapeutics are a mainstay of modern surgery and of clotting disorder management such as venous thrombosis, yet performance and supply limitations exist for the most widely used agent - heparin. Herein we report the first synthesis, characterization, and performance of sulfated poly-amido-saccharides (sulPASs) as heparin mimetics. sulPASs inhibit the intrinsic pathway of coagulation, specifically FXa and FXIa, as revealed by ex vivo human plasma clotting assays and serine protease inhibition assays. sulPASs activity positively correlates with molecular weight and degree of sulfation. Importantly, sulPASs are not degraded by heparanases and are non-hemolytic. In addition, their activity is reversed by protamine sulfate, unlike small molecule anticoagulants. In an in vivo murine model, sulPASs extend clotting time in a dose dependent manner with bleeding risk comparable to heparin. These findings support continued development of synthetic anticoagulants to address the clinical risks and shortages associated with heparin.

4.
R Soc Open Sci ; 5(10): 180291, 2018 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-30473805

RESUMEN

Personal lubricants can increase user satisfaction with male condoms by reducing friction and yielding a slippery sensation. However, lubricants pose disadvantages of dilution in physiologic fluids and sloughing away over repeated articulations. To address these drawbacks, a latex surface modification, which becomes lubricious in the presence of physiologic fluid, has been developed and evaluated. This study assesses (i) the frictional performance of the lubricious coating compared to non-coated latex and latex lubricated by personal lubricant, (ii) the level of agreement between human-perceived slipperiness and machine-measured friction, and (iii) human preference for a hypothetical male condom containing the lubricious coating. Friction coefficient of the lubricious coating was 53% lower than that of non-coated latex and approximately equal to that afforded by personal lubricant. A touch test and survey of a small population sample (N = 33) revealed a strong correlation (R 2 = 0.83) between human-perceived slipperiness and machine-measured friction. A majority of participants (73%) expressed a preference for a condom containing the lubricious coating, agreeing that an inherently slippery condom that remained slippery for a long duration would increase their condom usage. Such a coating shows potential to be an effective strategy for decreasing friction-associated pain, increasing user satisfaction and increasing condom usage.

5.
ACS Macro Lett ; 7(7): 772-777, 2018 Jul 17.
Artículo en Inglés | MEDLINE | ID: mdl-35650766

RESUMEN

Stereoregular poly-amido-saccharides bearing α-glucopyranose branches (Mal-PASs) are synthesized by anionic ring-opening polymerization of a maltose-based ß-lactam monomer followed by debenzylation. The polymerization affords high molecular weight polymers (up to 31500 g/mol) with narrow dispersities (D < 1.1). Deprotected Mal-PASs are highly soluble in water and adopt a left-handed helical conformation in solution. Turbidimetric assay shows that Mal-PASs are multivalent ligands to lectin Concanavalin A.

6.
J Am Chem Soc ; 139(40): 14217-14223, 2017 10 11.
Artículo en Inglés | MEDLINE | ID: mdl-28902504

RESUMEN

The design and synthesis of amide-linked saccharide oligomers and polymers, which are predisposed to fold into specific ordered secondary structures, is of significant interest. Herein, right-handed helical poly amido-saccharides (PASs) with ß-N-(1→2)-d-amide linkages are synthesized by the anionic ring-opening polymerization of an altrose ß-lactam monomer (alt-lactam). The right-handed helical conformation is engineered into the polymers by preinstalling the ß configuration of the lactam ring in the monomer via the stereospecific [2+2] cycloaddition of trichloroacetyl isocyanate with a d-glycal possessing a 3-benzyloxy group oriented to the α-face of the pyranose. The tert-butylacetyl chloride initiated polymerization of the alt-lactam proceeds smoothly to afford stereoregular polymers with narrow dispersities. Birch reduction of the benzylated polymers gives water-soluble altrose PASs (alt-PASs) in high yields without degradation of the polymer backbone. Circular dichroism analysis shows the alt-PASs adopt a right-handed helical conformation in aqueous solutions. This secondary conformation is stable over a wide range of different conditions, such as pH (2.0 to 12.0), temperature (5 to 75 °C), ionic salts (2.0 M LiCl, NaCl, and KCl), as well as in the presence of protein denaturants (4.0 M urea and guanidinium chloride). Cytotoxicity studies reveal that the alt-PASs are nontoxic to HEK, HeLa, and NIH3T3 cells. The results showcase the ability to direct solution conformation of polymers through monomer design. This approach is especially well-suited and straightforward for PASs as the helical conformations formed result from constraints imposed by the relatively rigid and sterically bulky repeating units.


Asunto(s)
Amidas/síntesis química , Lactamas/síntesis química , Polisacáridos/síntesis química , Amidas/química , Amidas/toxicidad , Animales , Supervivencia Celular/efectos de los fármacos , Reacción de Cicloadición , Células HEK293 , Células HeLa , Humanos , Lactamas/química , Lactamas/toxicidad , Ratones , Células 3T3 NIH , Polimerizacion , Polímeros/síntesis química , Polímeros/química , Polímeros/toxicidad , Polisacáridos/química , Polisacáridos/toxicidad
7.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 16(3): 676-80, 2008 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-18549653

RESUMEN

Blood donor recruitment models have changed from paid donors to employer-organized donors and to voluntary donors in China. Reports on the hepatitis C virus (HCV) infection among voluntary blood donors in China have been rarely found at present. The prevalence of anti-HCV and genotypes among the first-time voluntary blood donors was investigated in Chongqing area of China. A total of 13,620 serum samples were collected from the first-time voluntary blood donors in Chongqing, China. Anti-HCV antibody was tested by ELISA. The Core/E2 region of HCV RNA from HCV seropositive samples was amplified by RT-PCR for genotyping. The results indicated that the prevalence of anti-HCV averaged 0.49% (67/13,620), and the highest rate (0.86%) was obtained in the group aged 40 to 49. A higher prevalence was observed among the more educated donors, and metropolitan donors. The ratios of following genotypes 1b, 2a, 3a and 3b were 4 (18%), 5 (23%), 9 (41%) and 4 (18%) in all the 22 samples respectively. Genotype 3 (3a and 3b) was the predominant genotype. In conclusion, the prevalence of anti-HCV was low among the population of voluntary blood donors in Chonqing area. The genotyping results showed the possibility of presence of druggies among the voluntary blood donors. Therefore, more attention should be paid to exclude those high-risk persons from the volunteers.


Asunto(s)
Donantes de Sangre , Hepacivirus/genética , Hepatitis C/epidemiología , China/epidemiología , Genotipo , Hepacivirus/aislamiento & purificación , Hepatitis C/transmisión , Anticuerpos contra la Hepatitis C/sangre , Humanos , Incidencia , Estudios Seroepidemiológicos
8.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 13(2): 323-5, 2005 Apr.
Artículo en Chino | MEDLINE | ID: mdl-15854302

RESUMEN

To investigate the changes of free hemoglobin (FHb) content after mixing type B whole blood with different amounts of type O whole blood at room temperature and at 37 degrees C, two lots of type B whole blood stored at 4 degrees C for 24 hours were randomly taken as recipient blood, and were packed as 60 ml respectively. Type O blood was taken as donor blood. 60 ml type B whole bloods were mixed with different amounts of type O whole blood, i.e. with 9, 12, 15 and 18 ml. The mixed blood was packed into 100 ml plastic blood bags and stored at 37 degrees C or room temperature, shaken once every 15 minutes. Free hemoglobin content was determined for the harvested samples at 1, 2, 4, 8 and 12 hours after store. The results showed that there was no significant elevation of FHb within 12 hours after mixing B whole blood with different amounts of type O whole blood. In another lot, there was obvious difference in FHb after 1 hour store along with the prolongation of store at either room temperature or 37 degrees C. In one lot, there was no difference of FHb (P > 0.05) during 1 - 8 hours of store at room temperature or 37 degrees C, but significant difference at 12 hours of store (P < 0.001). In another lot, there was no difference of FHb (P > 0.05) within 1 hour of store at room temperature and at 37 degrees C, but significant difference during 2 approximately 8 hours of store (P < 0.001). It is concluded that the FHb would not change significantly within 12 hours after type B blood was mixed with 1 200 ml of type O whole blood, but when the mixed blood was placed at room temperature or at 37 degrees C for 8 hours, the FHb content approaches, even exceeds 170.4 mg/L which was observed in the blood stored for 2 days. It suggests that freshly collected blood must be put into refrigerator of 2 approximately 4 degrees C for storing as soon as possible, so as to decrease the catabolism of erythrocyte and the releasing of FHb and other metabolites which are deleterious to the recipients.


Asunto(s)
Sistema del Grupo Sanguíneo ABO/metabolismo , Eritrocitos/metabolismo , Hemoglobinas/metabolismo , Conservación de la Sangre/métodos , Humanos , Factores de Tiempo
9.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 12(1): 101-2, 2004 Feb.
Artículo en Chino | MEDLINE | ID: mdl-14989781

RESUMEN

Anti-H antibody belongs to IgM type cold antibody, which often induces the unconformity of positive and reverse typing and leads to the difficulty in clinical blood typing. Anti-H antibody was found during identification of the counter blood group in 3 cases. The antibody was found to be active at 37 degrees C, room temperature and 4 degrees C when determined by blood group serology, and was finally analyzed to be IgM. It is suggested that not to give erythrocytes of O group unreasoningly to blood recipient of AB group during emergent moment, but instead, to give same type of blood. If there was no same type of blood during urgent events, O type erythrocytes could be employed after being matched by saline centrifuging with host side coincidence and screened by incomplete method. In this case, anti-H antibody leading to adverse-reaction in blood transfusion should be prevented.


Asunto(s)
Sistema del Grupo Sanguíneo ABO/inmunología , Tipificación y Pruebas Cruzadas Sanguíneas , Isoanticuerpos/sangre , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad
10.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 12(6): 833-6, 2004 Dec.
Artículo en Chino | MEDLINE | ID: mdl-15631672

RESUMEN

The study was to investigate the hemorheologyic changes of group A blood recipient transfused with large amounts of group O whole blood, by erythrocyte count, sympexis index, erythrocyte deformation index, erythrocyte rigid index and whole blood reduced viscosity, 60 ml of group A whole blood were added with 9, 12, 15 and 18 ml of group O whole blood (which corresponds to the 4 000 ml whole blood added with 600, 800, 1 000 and 1 200 ml whole blood). The mixed blood was incubated at 37 degrees C with mixing at 80 times per minute. Samples were taken from the mixed blood at 30 minutes, 2, 4, 8, 12 and 24 hours after culture, and the hemorheology of the mixed whole blood was determined by FASCO-series type 3020B automatic rheograph apparatus. The results showed that there were no differences of erythrocyte count, sympexis index, erythrocyte deformation index, erythrocyte rigid index and whole blood reduced viscosity among all different kinds of mixed whole blood, and there was no difference of sympexis index at different times, but there were obvious differences of erythrocyte count, erythrocyte deformation index, erythrocyte rigid index and whole blood reduced viscosity. It is concluded that blood transfusion of 1,200 ml group O whole blood to a recipient with 50 kg of body weight but with different blood type in emergent situation may exert no harm to the erythrocytes of recipient in a short term.


Asunto(s)
Sistema del Grupo Sanguíneo ABO , Transfusión Sanguínea , Hemorreología , Incompatibilidad de Grupos Sanguíneos/sangre , Incompatibilidad de Grupos Sanguíneos/prevención & control , Recuento de Eritrocitos , Eritrocitos/citología , Citometría de Flujo/instrumentación , Citometría de Flujo/métodos , Hemodinámica , Humanos
11.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 11(5): 521-3, 2003 Oct.
Artículo en Chino | MEDLINE | ID: mdl-14575550

RESUMEN

The specificity of the antigens and length of preservation time of erythrocytes are the interfering factors in blood group serological tests. In order to clarify the influence of preservation time of erythrocytes on the blood matching test, the titers of anti-D antibody were detected with papain method, BioVue cross matching card and DianaGel cross matching card in 7 series of panel red blood cells preserved for various length of time (0 to 9 months). The results showed that the titer of micro-column gel test (DianaGel card) was one tube higher than that of column agglutinating test (BioVue card). The titer of erythrocytes preserved for 9 months was as high as 256 tested by DianaGel card, but it was only 2 by papain method in the same anti-serum. It is suggested that there was no obvious difference between the results of micro-column gel test and column agglutinating test, and titer of papain method was the lowest.


Asunto(s)
Tipificación y Pruebas Cruzadas Sanguíneas , Conservación de la Sangre , Eritrocitos/inmunología , Isoanticuerpos/sangre , Humanos , Globulina Inmune rho(D) , Factores de Tiempo
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA