Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 8 de 8
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Arch Gynecol Obstet ; 308(2): 363-377, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-36058943

RESUMO

PURPOSE: To evaluate the risk of miscarriage in IVF cycles in women with PCOS. METHODS: Systematic review and meta-analysis. Systematic search of MEDLINE, EMBASE and Google Scholar. The language search was restricted to English, Spanish and French, from 2000 to 2019, with crosschecking of references from relevant articles. Inclusion criteria were: (1) IVF cycles (2) a group of patients with PCOS was considered separately, (3) the miscarriage rate was reported, (4) there was a control group, (5) definition of PCOS according the Rotterdam criteria. Exclusion criteria were been excluded from the meta-analysis: (1) publication prior to the year 2000, (2) animal studies, (3) reviews, (4) abstracts or conference papers, (5) letters, (6) case reports, (7) studies comparing different IVF techniques, (8) studies comparing groups with and without metformin or other treatments, (9) studies on induced abortions. Risk of bias was assessed by the Newcastle-Ottawa score (NOS). All the included studies had a low risk of bias (NOS scores ranging 7-8). The review protocol was registered in PROSPERO (CRD42020186713). Seventeen studies were included in the meta-analysis. There was a total of 10,472 pregnancies (2650 in PCOS and 7822 in controls) of which 1885 were miscarriages (682 in PCOS and 1203 in controls). We considered the miscarriage rate (MR), preclinical MR, early MR, and late MR. RESULTS: In IVF pregnancies the risk of miscarriage was significantly increased when considering miscarriages in total (RR = 1.59; CI = 1.45-1.75), preclinical miscarriages (RR = 1.59; CI = 1.35-1.88), and early miscarriages (RR = 1.44; CI = 1.16-1.79). The increased miscarriage rate persisted in Chinese and Western populations when considered separately. The risk of miscarriage was increased in the subgroup of fresh transfers (RR = 1.21; CI = 1.06-1.39) as well as in the subgroup including either fresh or frozen transfers (RR = 1.95; CI = 1.72-2.22). CONCLUSION: PCOS is linked to an increased MR in IVF pregnancies both of miscarriages in total, and to an increase in preclinical and early miscarriages. PROSPERO NUMBER: CRD42020186713.


Assuntos
Aborto Espontâneo , Metformina , Síndrome do Ovário Policístico , Feminino , Humanos , Gravidez , Aborto Espontâneo/epidemiologia , Aborto Espontâneo/etiologia , Fertilização in vitro/efeitos adversos , Fertilização in vitro/métodos , Síndrome do Ovário Policístico/complicações , Taxa de Gravidez
2.
Acta Biochim Pol ; 69(1): 233-243, 2022 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-35148045

RESUMO

Nanomedicine has led to the development of new biocompatible and biodegradable materials able to improve the pharmaceutical effect of bioactive components, broadening the options of treatment for several diseases, including cancer. Additionally, some snake venom toxins have been reported to present cytotoxic activity in different tumor cell lines, making them an auspicious option to be used as cancer drugs. The present study aims to evaluate the cytotoxic activity of the northern black-tailed rattlesnake (Crotalus molossus molossus) venom-loaded chitosan nanoparticles (Cs-Venom NPs) against the T-47D breast carcinoma cell line. To do so, we first identified the significant proteins composing the venom; afterward, hemocompatibility and cytotoxic activity against tumoral cells were evaluated. The venom was then loaded into chitosan nanoparticles through the ionotropic gelation process, obtaining particles of 415.9±21.67 nm and ζ-potential of +28.3±1.17 mV. The Cs-Venom complex delivered the venom into the breast carcinoma cells, inhibiting their viability and inducing morphological changes in the T-47D cells. These features indicate that these nanoparticles are suitable for the potential use of C. m. molossus venom toxins entrapped within polymer nanoparticles for the future development and research of cancer drugs.


Assuntos
Antineoplásicos/farmacologia , Neoplasias da Mama/patologia , Quitosana/química , Venenos de Crotalídeos/farmacologia , Nanopartículas/química , Animais , Antineoplásicos/química , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Venenos de Crotalídeos/química , Crotalus , Sistemas de Liberação de Medicamentos/métodos , Feminino , Humanos , Masculino , Nanomedicina/métodos , Venenos de Serpentes/farmacologia
3.
RSC Adv ; 10(20): 11971-11981, 2020 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-35496627

RESUMO

Tobacco smoke contains several compounds with oxidant and pro-oxidant properties with the capability of producing structural changes in biomolecules, as well as cell damage. This work aimed to describe and analyse the effect of tobacco smoke on human blood components, red blood cell (RBC) membrane, haemoglobin (Hb) and blood plasma by Atomic Force Microscopy (AFM) and Raman spectroscopy. Our results indicate that tobacco induced RBC membrane nano-alterations characterized by diminished RBC diameter and increased nano-vesicles formation, and RBC fragility. The Raman spectra profile suggests modifications in chemical composition specifically found in peaks 1135 cm-1, 1156 cm-1, 1452 cm-1 and intensity relation of peaks 1195 cm-1 and 1210 cm-1 of blood plasma and by change of peaks 1338 cm-1, 1357 cm-1, 1549 cm-1 and 1605 cm-1 associated with the pyrrole ring of Hb. The relevance of these results lies in the identification of a profile of structural and chemical alterations that serves as a biomarker of physiological and pathological conditions in the human blood components induced by tobacco exposure using AFM and the Raman spectroscopy as tools for monitoring them.

4.
RSC Adv ; 9(18): 9899-9906, 2019 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-35520911

RESUMO

In this work, we report the evaluation of lactosylated graphene oxide (GO-AL) as a potential drug carrier targeted at an asialoglycoprotein receptor (ASGPR) from hepatic cancer cells. Structural-modification, safety evaluation, and functional analysis of GO-AL were performed. The structure and morphology of the composite were analyzed by scanning electron microscopy (SEM) and atomic force microscopy (AFM), while Raman and FTIR spectroscopy were used to track the chemical modification. For the safe application of GO-AL, an evaluation of the cytotoxic effect, hemolytic properties, and specific interactions of the glycoconjugate were also studied. SEM and AFM analysis of the GO showed graphene sheets with a layer size of 2-3 nm, though a few of them reached 4 nm. The Raman spectra presented characteristic peaks of graphene oxide at 1608 cm-1 and 1350 cm-1, corresponding to G and D bands, respectively. Besides, Si-O peaks for the APTES conjugates of GO were identified by FTIR spectroscopy. No cytotoxic or hemolytic effects were observed for GO samples, thus proving their biocompatibility. The interaction of Ricinus communis lectin confirmed that GO-AL has a biorecognition capability and an exposed galactose structure. This biorecognition capability was accompanied by the determination of the specific absorption of lactosylated GO by HepG2 cells mediated through the asialoglycoprotein receptor. The successful conjugation, hemolytic safety, and specific recognition described here for lactosylated GO indicate its promise as an efficient drug-delivery vehicle to hepatic tissue.

5.
Food Sci Biotechnol ; 27(1): 57-64, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30263724

RESUMO

Muscle from mantle, fins and arms of squid (Dosidicus gigas) were compared based on lysyl oxidase activity (LOX), chemical/structural and thermodynamic properties of highly cross-linked collagen. The arms collagen presented the highest temperature (Tp) and enthalpy of transition. The arms collagen thermic properties may be explained by the higher imino amino acid content, proline and lysine hydroxylation degrees. Moreover, among the regions, the collagen from the arms had a more intense ß band chain, hydroxymerodesmosine peak in the resonance magnetic nuclear spectra and pyridinoline peak in the Raman spectra. Fins showed the highest LOX activity. The LOX activity was associated with the Tp, proline and lysine hydroxylation degrees. These results implied that the collagen in the arms was more intermolecularly ordered than the mantle and fins, and may provide a theoretical basis for a better understanding of the thermal behaviour of squid tissues during management and processing.

6.
Acta Biochim Pol ; 64(4): 679-686, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29202487

RESUMO

Adhesion of enterotoxigenic (ETEC) E. coli to host intestinal cells is mediated by lectin-like fimbriae that bind to specific glycan moieties on the surfaces of enterocytes. To prevent in vitro binding of E. coli F4 fimbriae (F4 ETEC+) to piglet enterocytes, neoglycans were synthesized by the Maillard reaction conjugating lactose (Lac), galacto-oligosaccharides (GOS) or chitin oligosaccharides (Ochit) to porcine serum albumin (PSA). Neoglycans were characterized by SDS-PAGE, intrinsic tryptophan fluorescence and recognition by plant lectins, as well as by F4 ETEC variants. Electrophoretic patterns suggested the binding to PSA of 63, 13 and 2 molecules of Lac, GOS and Ochit, respectively. All neoglycans displayed quenching of tryptophan fluorescence consistent with the degree of glycation estimated by SDS-PAGE. Plant lectins recognized the neoglycans according to their specificity, whereas antigenic variants of F4 ETEC (ab, ac and ad) recognized PSA-Ochit and PSA-Lac with higher affinity than that for GOS. Neoglycans partially hindered the in vitro binding of F4+ ETEC to piglet enterocytes in a dose-dependent manner. The most effective blocking was observed with PSA-Lac that partially inhibited the adhesion of bacteria to enterocytes in a dose dependent manner, as quantified by flow cytometry. Increased production of the cytokines IL-6 and TNF-α was observed in response to F4+ ETEC infection of enterocytes and production was reduced in the presence of PSA-Ochit and PSA-GOS. These results suggest that neoglycans synthesized by the Maillard reaction could be useful in the prophylaxis of diarrhea in piglets.


Assuntos
Enterócitos/efeitos dos fármacos , Enterócitos/microbiologia , Escherichia coli Enterotoxigênica/efeitos dos fármacos , Polissacarídeos/química , Polissacarídeos/farmacologia , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Aderência Bacteriana/efeitos dos fármacos , Eletroforese em Gel de Poliacrilamida , Escherichia coli Enterotoxigênica/patogenicidade , Infecções por Escherichia coli/tratamento farmacológico , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/veterinária , Produtos Finais de Glicação Avançada/química , Intestinos/citologia , Intestinos/microbiologia , Suínos , Doenças dos Suínos/virologia
7.
Int J Mol Sci ; 16(9): 22425-37, 2015 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-26389896

RESUMO

The formulation and characterization of gentamicin-loaded microspheres as a delivery system targeting enterotoxigenic Escherichia coli K88 (E. coli K88) was investigated. Glycated albumin with lactose (BSA-glucose-ß (4-1) galactose) was used as the microsphere matrix (MS-Lac) and gentamicin included as the transported antibiotic. The proposed target strategy was that exposed galactoses of MS-Lac could be specifically recognized by E. coli K88 adhesins, and the delivery of gentamicin would inhibit bacterial growth. Lactosylated microspheres (MS-Lac1, MS-Lac2 and MS-Lac3) were obtained using a water-in-oil emulsion, containing gentamicin, followed by crosslinking with different concentrations of glutaraldehyde. Electron microscopy displayed spherical particles with a mean size of 10-17 µm. In vitro release of gentamicin from MS-Lac was best fitted to a first order model, and the antibacterial activity of encapsulated and free gentamicin was comparable. MS-Lac treatments were recognized by plant galactose-specific lectins from Ricinus communis and Sophora japonica and by E. coli K88 adhesins. Results indicate MS-Lac1, produced with 4.2 mg/mL of crosslinker, as the best treatment and that lactosylated microsphere are promising platforms to obtain an active, targeted system against E. coli K88 infections.


Assuntos
Antibacterianos/administração & dosagem , Antígenos de Bactérias/metabolismo , Proteínas de Escherichia coli/metabolismo , Proteínas de Fímbrias/metabolismo , Gentamicinas/administração & dosagem , Microesferas , Albuminas/química , Antibacterianos/farmacologia , Escherichia coli/efeitos dos fármacos , Escherichia coli/metabolismo , Gentamicinas/farmacologia , Lactose/química , Lectinas de Plantas/metabolismo , Ligação Proteica
8.
Food Chem ; 141(3): 2727-34, 2013 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-23871017

RESUMO

Enterotoxigenic (ETEC) Escherichia coli (E. coli) causes traveller's diarrhoea and high mortality among baby animals. ETEC adhesion is mediated by lectins (adhesins) that bind to glycoconjugates on the surface of host cells. Glycans that compete for adhesion could be used for disease prevention. Neoglycans of porcine albumin (PSA) that were conjugated with prebiotic galactooligosaccharides (GOS) were synthesised using the Maillard reaction. PSA glycation was confirmed by a reduction in the number of available free amino groups, decreased tryptophan intrinsic fluorescence, increased molecular mass and Ricinus communis lectin recognition. The adhesion of four ETEC strains (E. coli H10407, CFA(+), K99 and K88) to PSA-GOS was examined by an enzyme-linked lectin assay. E. coli K88 bound to PSA-GOS with greater affinity (P<0.05) than did E. coli H10407, CFA(+) and K99. In addition, PSA-GOS partially inhibited the adherence of the K88 strain to intestinal mucins. Pig ETEC strain was unable to ferment galactooligosaccharide-neoglycans. These results suggest that neoglycans obtained by the Maillard reaction may serve in the prophylaxis of ETEC K88 diarrhoea.


Assuntos
Aderência Bacteriana , Escherichia coli Enterotoxigênica/fisiologia , Infecções por Escherichia coli/veterinária , Oligossacarídeos/metabolismo , Polissacarídeos/metabolismo , Prebióticos/microbiologia , Doenças dos Suínos/microbiologia , Albuminas/química , Albuminas/metabolismo , Animais , Linhagem Celular , Escherichia coli Enterotoxigênica/química , Infecções por Escherichia coli/metabolismo , Infecções por Escherichia coli/microbiologia , Glicosilação , Mucosa Intestinal/metabolismo , Intestinos/microbiologia , Cinética , Reação de Maillard , Mucinas/metabolismo , Oligossacarídeos/química , Polissacarídeos/química , Prebióticos/análise , Sus scrofa , Suínos , Doenças dos Suínos/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...