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1.
J Org Chem ; 88(13): 8123-8132, 2023 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-37235643

RESUMO

The regioselective synthesis of multiple disulfide bonds in peptides has been a significant challenge in synthetic peptide chemistry. In this work, two disulfide bonds in peptides were regioselectively synthesized via an approach of MetSeO oxidation and deprotection reaction (SeODR), in which the first disulfide bond was constructed through oxidation of dithiol by MetSeO in a neutral buffer, and the second disulfide bond was then directly constructed through the deprotection of two Acm groups or one Acm group and one Thz group by MetSeO in acidic media. Synthesis of two disulfide bonds by the SeODR approach was achieved through a one-pot manner. Moreover, the SeODR approach is compatible with the synthesis of peptides containing methionine residues. Both H+ and Br- drastically promoted the reaction rate of SeODR. The mechanistic picture for the SeODR approach was delineated, in which the formation of a stable Se-X-S bridge as the transition state plays a critical role. The SeODR approach was also utilized to construct the three disulfide bonds in linaclotide, conferring a reasonable yield.


Assuntos
Dissulfetos , Peptídeos , Indicadores e Reagentes , Dissulfetos/química , Peptídeos/química , Metionina/química , Metionina/metabolismo , Oxirredução
2.
J Org Chem ; 87(2): 1470-1476, 2022 01 21.
Artigo em Inglês | MEDLINE | ID: mdl-34985274

RESUMO

In this study, we developed an efficient approach for disulfide bond formation in peptides utilizing the Pt(IV) complex trans-[PtBr2(CN)4]2- to mediate Acm and Thz deprotections. [PtBr2(CN)4]2- can oxidatively deprotect two Acm groups or deprotect one Thz group and one Acm group to directly form an intramolecular disulfide bond in peptides. Several disulfide-containing peptides with excellent yields were achieved via the deprotection method in an aqueous medium under aerobic conditions. Kinetic studies indicated that the dominant path of the reaction is of first-order in both [Pt(IV)] and [peptide]; moreover, the deprotection rate increased dramatically with the addition of NaBr. A mechanism including a bromide-bridge-mediated electron transfer process was proposed. Apamin, α-conotoxin SI, and the parallel homodimer of oxytocin, all containing two disulfide bonds, were synthesized regioselectively through a one-pot method by the combined use of the above deprotection approach with oxidants l-methionine selenoxide and [PtBr2(CN)4]2-. All of the reactions were completed within 30 min to afford good yields for these peptides.


Assuntos
Cisteína , Peptídeos , Dissulfetos , Cinética , Tiazolidinas
3.
J Org Chem ; 86(5): 4035-4044, 2021 03 05.
Artigo em Inglês | MEDLINE | ID: mdl-33620221

RESUMO

In this study, l-methionine selenoxide (MetSeO) was used as an oxidant for the construction of peptide disulfide bonds. Excellent yields for various disulfide-containing peptides were achieved via the MetSeO oxidation method in different solvents and on a resin. Most importantly, the construction of disulfide bonds can be performed in the trifluoroacetic acid cocktail used for the cleavage of peptides from the resin, which obviates the steps of peptide purification and lyophilization. This facilitates and simplifies the synthesis of disulfide-containing peptides. Kinetic and mechanistic studies of the reaction between MetSeO and dithiothreitol (DTT, a model compound of dicysteine-containing peptide) show that the reaction is first order in both [MetSeO] and [DTT], and a reaction mechanism is proposed that can help us gain insights into the reaction of the oxidative synthesis of disulfide bonds via MetSeO oxidation.


Assuntos
Dissulfetos , Metionina , Metionina/análogos & derivados , Metionina/metabolismo , Compostos Organosselênicos , Oxirredução , Peptídeos , Óxidos de Selênio
4.
Macromol Rapid Commun ; 41(23): e2000393, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33089640

RESUMO

Obtaining a large open-circuit voltage (VOC ) and high short-circuit current density (JSC ) simultaneously is important in improving power conversion efficiency (PCE) of organic photovoltaics. The ternary strategy with using a higher lowest unoccupied molecular orbital (LUMO) level nonfullerene acceptor (NFA) guest can achieve increased VOC , yet JSC is decreased or maintained, so it's still a challenge to offer increased VOC and JSC values concurrently via the newly presented VOC -increased ternary strategy. To overcome this issue, a new narrow bandgap NFA TT-S-4F is reported by introducing 3,6-dimethoxylthieno[3,2-b]thiophene (TT) as π-spacers to connect electron-rich core with terminal groups, so as to upshift the LUMO level and extend π-system. When adding 10% TT-S-4F into binary system based on PTB7-Th:IEICO-4F, the higher-LUMO-level of TT-S-4F, the increased charge mobilities, the reduced trap-assisted combination loss, and a finer nanofiber structure and increased phase separation size are obtained, which simultaneously promotes JSC , VOC , and fill factor (FF), thus obtaining an optimal PCE (12.5% vs 11.5%). This work illustrates that an extending conjugated backbone with large π-spacers and inclusion of alkylthiophenyl side-chains is a concept to synthesize NFA guests for use on the VOC -increased ternary strategy that enables to realize simultaneously increased JSC , VOC , and FF.


Assuntos
Nanofibras , Energia Solar , Fontes de Energia Elétrica , Polímeros , Tiofenos
5.
Molecules ; 22(2)2017 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-28241453

RESUMO

Some peptide-based drugs, including oxytocin, vasopressin, ziconotide, pramlintide, nesiritide, and octreotide, contain one intramolecular disulfide bond. A novel and reusable monodispersed silica nanosphere-supported Pt(IV) complex (SiO2@TPEA@Pt(IV)); TPEA: N-[3-(trimethoxysilyl)propyl]ethylenediamine) was synthesized via a four-step procedure and was used for the formation of intramolecular disulfide bonds in peptides. Transmission electron microscopy (TEM) and chemical mapping results for the Pt(II) intermediates and for SiO2@TPEA@Pt(IV) show that the silica nanospheres possess a monodisperse spherical structure and contain uniformly-distributed Si, O, C, N, Cl, and Pt. The valence state of Pt on the silica nanospheres was characterized by X-ray photoelectron spectroscopy (XPS). The Pt(IV) loaded on SiO2@TPEA@Pt(IV) was 0.15 mmol/g, as determined by UV-VIS spectrometry. The formation of intramolecular disulfides in six dithiol-containing peptides of variable lengths by the use of SiO2@TPEA@Pt(IV) was investigated, and the relative oxidation yields were determined by high-performance liquid chromatography (HPLC). In addition, peptide 1 (Ac-CPFC-NH2) was utilized to study the reusability of SiO2@TPEA@Pt(IV). No significant decrease in the relative oxidation yield was observed after ten reaction cycles. Moreover, the structure of SiO2@TPEA@Pt(IV) after being used for ten cycles was determined to be similar to its initial one, demonstrating the cycling stability of the complex.


Assuntos
Complexos de Coordenação/química , Dissulfetos/química , Nanosferas/química , Peptídeos/química , Platina/química , Dióxido de Silício/química , Cromatografia Líquida de Alta Pressão , Oxidantes/química , Oxirredução , Espectroscopia Fotoeletrônica , Espectrometria de Massas por Ionização por Electrospray , Compostos de Sulfidrila/química
6.
Bioorg Med Chem Lett ; 26(17): 4261-6, 2016 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-27481559

RESUMO

The reduction of ormaplatin (tetraplatin), a prototype for Pt(IV) anticancer prodrugs, by glutathione (GSH) was kinetically characterized over a wide pH range at 25.0°C and 1.0M ionic strength. The reduction follows overall second-order kinetics, giving rise to the oxidized glutathione as the oxidation product, which was identified by high-resolution mass spectrometry. The reaction mechanism put forward involves parallel attacks by all the GSH species on the Pt(IV) prodrug as rate-determining steps. All rate constants for the rate-determining steps have been derived for the first time, enabling the construction of the reactivity of GSH species versus their pH distribution diagram. The diagram clearly displays that only one out of the five GSH species is the mainly responsible for the reduction of ormaplatin at the physiological pH of 7.4.


Assuntos
Antineoplásicos/química , Glutationa/química , Compostos Organoplatínicos/química , Concentração de Íons de Hidrogênio , Cinética , Espectrometria de Massas , Concentração Osmolar , Oxirredução , Pró-Fármacos/química
7.
Poult Sci ; 94(4): 601-11, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25667425

RESUMO

Avian pathogenic Escherichia coli (APEC) causes extensive mortality in poultry flocks, leading to extensive economic losses. To date, little information has been available on the molecular basis of antimicrobial resistance in APEC in Hebei, China. Therefore, the objective of this study was to characterize the virulence and antimicrobial resistance of multidrug-resistant APEC isolated from septicemic broilers at the molecular level. Among 87 nonrepetitive E. coli isolates, 41 (47.1%) carried 3 or more of the APEC virulence genes iroN, ompT, iss, iutA, and hlyF. All 87 APEC isolates showed multidrug-resistant phenotypes, particularly against ampicillin, kanamycin, ciprofloxacin, levofloxacin, streptomycin, gentamycin, ofloxacin, norfloxacin, and ceftriaxone. The ß-lactamase-encoding genes blaTEM, blaCMY-2, blaOXA-30, blaCTX-M-15, and blaSHV-2; the aminoglycoside-modifying enzymes (AME) strA, strB, aph(3')-IIa, aac(3)-IIa, aac(6')-Ib, and ant(3″)-Ia; and the plasmid-mediated quinolone resistance (PMQR) genes qnrA, qnrB, and qnrS, were also identified in 66 (75.9%), 65 (74.7%), and 6 (6.9%) isolates, respectively. All isolates were evaluated in terms of replicon type. The plasmid replicons were identified in 63 (72.4%) isolates, and the FIB, B/O, and K replicons were the most present. To the best of our knowledge, this is the first report of molecular characterization of antimicrobial resistance in APEC strains from China.


Assuntos
Antibacterianos/farmacologia , Galinhas , Farmacorresistência Bacteriana Múltipla , Infecções por Escherichia coli/veterinária , Escherichia coli/patogenicidade , Doenças das Aves Domésticas/epidemiologia , Sepse/veterinária , Animais , China/epidemiologia , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Infecções por Escherichia coli/epidemiologia , Infecções por Escherichia coli/microbiologia , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Reação em Cadeia da Polimerase Multiplex/veterinária , Doenças das Aves Domésticas/microbiologia , Sepse/epidemiologia , Sepse/microbiologia , Virulência
8.
Poult Sci ; 93(2): 335-9, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24570454

RESUMO

In this study, the quinolone-resistant determining region (QRDR) of gyrA of Escherichia coli and plasmid-mediated quinolone resistance (PMQR) genes, qnr(qnrA, qnrB, and qnrS), and aac(6 ')-Ib-cr were detected, sequenced, and analyzed. In addition, antimicrobial susceptibility tests (using the Kirby-Bauer disc diffusion method) were performed for all 111 E. coli isolates from septicemic broilers in Hebei, China. The results show that the resistance rates were as follows: ofloxacin 99.10%, ciprofloxacin 93.69%, levofloxacin 91.89%, norfloxacin 90.09%, and gatifloxacin 76.58%. Of the PMQR genes examined, aac(6 ')-Ib-cr (36.04%) was the most frequently identified gene in all isolates, followed by qnrS (8.11%), qnrB (0.90%), and qnrA (0%). Of the QRDR examined in the 40 phenotypic quinolone-resistant isolates, compared with the gyrA(+) gene of E. coli K-12, 4 amino acid exchanges were found, namely Ser-83→Asp, Asp-87→Asn, Asp-87→Tyr, and Asp-87→Ala, and all 40 isolates had 1 or 2 exchanges in QRDR. It was concluded that quinolone-resistance in E. coli remains a serious problem in Hebei, China. Therefore, there is considerable local surveillance of quinolone resistance. Plasmid-mediated quinolone resistance of the qnr type remains rare in Hebei, China, and mutation in QRDR may be the main problem.


Assuntos
Antibacterianos/farmacologia , DNA Girase/genética , Farmacorresistência Bacteriana , Proteínas de Escherichia coli/genética , Escherichia coli/genética , Quinolonas/farmacologia , Animais , Galinhas , China/epidemiologia , DNA Girase/metabolismo , Escherichia coli/metabolismo , Infecções por Escherichia coli/epidemiologia , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/veterinária , Proteínas de Escherichia coli/metabolismo , Testes de Sensibilidade Microbiana/veterinária , Epidemiologia Molecular , Dados de Sequência Molecular , Reação em Cadeia da Polimerase/veterinária , Doenças das Aves Domésticas/epidemiologia , Doenças das Aves Domésticas/microbiologia , Prevalência , Análise de Sequência de DNA/veterinária
9.
J Nanosci Nanotechnol ; 13(6): 4456-61, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23862520

RESUMO

A series of uniform and well-dispersed TiO2 spheres have been successfully synthesized through a controlled hydrolysis route by using different titanium alkoxides as reactants. The types of titanium alkoxides and stirring time have an effect on the uniformity and dispersion of the TiO2 spherical particles. The addition of a small amount of salt also plays a crucial role for the formation of the monodisperse TiO2 spheres. Under ultraviolet excitation, the as-obtained Eu(3+)-doped TiO2 spheres exhibit red emission corresponding to the electric-dipole allowed 5D0-7F2 transition of Eu3+ ions, which is induced by the lack of inversion symmetry at the Eu3+ ions site. The Eu(3+)-doped TiO2 phosphors might find potential applications in the fields such as optical displays, photoelectric devices, and light-emitting diodes (LEDs).

10.
J Biomed Biotechnol ; 2012: 503093, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23093848

RESUMO

Few data have suggested how norepinephrine (NE) and acetylcholine (Ach) regulate the development of Leydig cells in mice at prepuberty, except for data indicating endocrine effects. The present study aims to elucidate the roles of NE and Ach on the differentiation and proliferation of Leydig cells. Firstly, the expression of adrenergic receptors and muscarinic acetylcholine receptors in Leydig cells was investigated. It was found that adrenergic receptors (ß1AR, ß2AR, and α1D) and muscarinic acetylcholine receptors (M1 and M3) mRNA are expressed in adult Leydig cells. Then, the effects of NE and Ach on the differentiation and proliferation of Leydig cells were analyzed. The results showed that NE and Ach at 10 µM significantly increased the number of 3ß-hydroxysteroid-dehydrogenase- (3ß-HSD-) positive Leydig cells and improved the expression of proliferating cell nuclear antigen (PCNA) in Leydig cells on postnatal day (PD) 15 (P < 0.05). NE and Ach at 10 µM had no impact on the expression of PCNA mRNA (P > 0.05), but reduced the expression of 3ß-HSD mRNA in adult Leydig cells and a murine Leydig tumor cell line (MLTC-1) (P < 0.05). Therefore, a conclusion may be reached that NE and Ach participated in stimulating the development of Leydig cells in mice from prepuberty to adult stage.


Assuntos
Acetilcolina/farmacologia , Células Intersticiais do Testículo/citologia , Células Intersticiais do Testículo/fisiologia , Norepinefrina/farmacologia , Animais , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Células Intersticiais do Testículo/efeitos dos fármacos , Masculino , Camundongos
11.
Animals (Basel) ; 12(20)2022 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-36290263

RESUMO

Enteric viruses, as a potential pathogen, have been found to be vital causes of economic losses in poultry industry worldwide. The enteric viruses widely studied to date mainly include avian nephritis virus (ANV), avian reovirus (ARe), chicken astrovirus (CAstV), chicken parvovirus (ChPV), fowl adenovirus group I (FAdV-1), infectious bronchitis virus (IBV), and avian rotavirus (ARoV). This paper aimed to identify single and multiple infections of the seven enteric viruses using the data obtained from positive 145 enteric virus samples in poultry flocks from different areas in Hebei Province, throughout the period from 2019 to 2021. Next, the correlation between bird age and clinical signs was investigated using PCR and RT-PCR techniques. Furthermore, the whole genomes of seven parvovirus strains and open reading frame 2 (ORF2) of six CAstV strains and eight ANV strains were sequenced for phylogenetic analysis and recombination analysis, to characterize the viruses and evaluate species correlation and geographic patterns. A total of 11 profiles of virus combinations were detected; 191 viruses were detected in 145 samples; 106 single infections were reported in 73.1% of the samples; and multiple infections were detected in the remaining 26.9%. For viruses, 69% of ChPV was correlated with single infection, while ANV (61.4%) and CAstV (56.1%) were correlated with multiple infections. However, IBV and ARe were not detected in any of the samples. Recombination events were reported in parvovirus, and all CAstV sequences investigated in this paper were included within genotype Bii. The eight ANV strains pertained to different subtypes with significant differences. The above results revealed for the first time the complexity of enteric viruses over the past several years, thus contributing to disease prevention and control in the future.

12.
Poult Sci ; 101(2): 101306, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34942517

RESUMO

The objective of this experimental study was to examine the effects of the Chinese herbal medicines Patchouli and Elsholtzia on the follicular granulosa cells of hens undergoing heat stress conditions. In the current investigation, hen follicular granulosa cells were isolated from the prehierarchical follicles of layer hens and then cultured in-vitro. The cells were randomly divided into the 6 groups. Following the completion of this study's experiments using different heat stress and medicinal treatments, the cell activities of each group were measured using an MTT method. The levels of the heat shock protein 70 (HSP70) were detected using ELISA. The expressions of the steroidogenic acute regulatory protein (StAR) mRNA; cytochrome P450 family 11, subfamily A, member 1 (CYP11A1) mRNA; proliferating cell nuclear antigen (PCNA) mRNA; and the follicle stimulating hormone receptor (FSHR) were detected using the real-time quantitative polymerase chain reactions. The concentration levels of estrogen and progesterone in the cell supernatant of each group were measured using ELISA. The results showed that cell activity had significantly decreased following the heat stress treatments at 43℃, 44℃, and 45℃ (P < 0.01), respectively. Meanwhile, cell activities observed in Patchouli and Elsholtzia were found to be much better than those of heat stress group (P < 0.05). In addition, the expression levels of HSP70 in the follicular granulosa cells of Patchouli and Elsholtzia groups were lower than those of heat stress group. Patchouli and Elsholtzia can maintain expressions of the receptor at 43℃. This study determined that the estrogen and progesterone in the supernatant fluid of Patchouli and Elsholtzia were higher than those observed in heat stress. Therefore, the results obtained in this study indicated that the Patchouli and Elsholtzia treatments administered prior the heat stress experiments had successfully protected the follicular granulosa cells from heat damages while maintaining the normal secretory functions of the granulosa cells.


Assuntos
Galinhas , Pogostemon , Animais , Células Cultivadas , Feminino , Células da Granulosa , Resposta ao Choque Térmico , Progesterona
13.
Poult Sci ; 101(5): 101756, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35367690

RESUMO

Aspergillus flavus and Aspergillus fumigatus were derived and identified from the ducks infected with fungi. In order to investigate the effectiveness of Chinese herbal medicines against Aspergillus flavus and Aspergillus fumigatus, in vitro antibacterial test and animal infection control test were conducted to study the antibacterial activity of the Chinese medicine mixture which was compatible with Acorus gramineus, Phellodendron chinensis, and Cassia obtusifolia. According to the results, the liver of chickens infected with Aspergillus flavus and Aspergillus fumigatus displayed granulomatous lesions, indicating that the isolation of pathogen from the lungs of sick ducks is also pathogenic to chickens. As suggested by the results of in vitro drug sensitivity test, the mixture 1 MIC80 was the minimum, the MIC80 of Aspergillus flavus was 16 µg/µL, and the MIC80 of Aspergillus fumigatus was 4 µg/µL. In a petri dish of the same concentration, the colony diameter of Aspergillus flavus and Aspergillus fumigatus in Mixture 1 was the minimum. Besides, Aspergillus flavus colonies grew when the concentration was 64 µg/µL, and Aspergillus fumigatus colonies grew when the concentration was 4 µg/µL, which suggests the more significant inhibitory effect of Mixture 1 on Aspergillus flavus and Aspergillus fumigatus. According to the results of animal experiments, there was a significantly lower activity level of Glutamic oxaloacetic transaminase (GOT) and Glutamate pyruvic transaminase (GPT) in the protection group and the treatment group than in the bacterial infection group. As indicated by the blood smear results, there were more neutrophils in the infected group than in the prevention group and the treatment group. Thus, it can be seen from that the Mixture 1 produced preventive and therapeutic effects on the chickens infected with Aspergillus flavus and Aspergillus fumigatus.


Assuntos
Aspergillus fumigatus , Medicamentos de Ervas Chinesas , Animais , Antibacterianos/farmacologia , Aspergillus flavus , Galinhas , Medicamentos de Ervas Chinesas/farmacologia , Patos , Feminino
14.
Poult Sci ; 100(4): 101003, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33676095

RESUMO

Previously, a fungus was isolated from a diseased pigeon group clinically suspected of being infected with Candida. The fungus was subsequently identified as Candida glabrata using morphology, physiology, biochemistry, and molecular biology testing methods. In the present study, to determine the controlling effects of Chinese herbal medicine for C. glabrata, the bacteriostatic effects of the ethanol extracts Acorus gramineus, Sophora flavescens, Polygonum hydropiper, Cassia obtusifolia, Pulsatilla chinensis, Dandelion, and Cortex phellodendri on C. glabrata in vitro were analyzed. The results showed that the minimum inhibitory concentrations (MIC80) of Cortex phellodendri was 0.25 µg/µL. Meanwhile, that of S. flavescens was 32 µg/µL; C. obtusifolia was 56 µg/µL; A. gramineus and Polygonum hydropiper was 64 µg/µL; and P. chinensis was 112 µg/µL. However, MIC80 for Dandelion was undetectable. In addition, improved drug sensitivity tests revealed that colonies had grown after 24 h in the blank group, as well as the Polygonum hydropiper, P. chinensis, Dandelion, and ethanol groups. The colonies first appeared at the 48-hour point in the other drug-sensitive medium of Chinese herbal medicine. However, no colony growth was found in Cortex phellodendri medium, and the formation of the maximum colony diameter in that group was later than the blank group (e.g., 96 h in the blank group and 120 h in the Chinese herbal medicine group). It was observed that only 17 colony-forming units had grown in 125 µg/µL of the S. flavescens medium, which was significantly different from other groups. Also, the final colony diameter was significantly smaller than that of the other experimental groups. Therefore, it was determined that the A. gramineus, S. flavescens, Polygonum hydropiper, Cassia obtusifolia, P. chinensis, and Cortex phellodendri had certain inhibitory effects on the growth of the C. glabrata. Among those, it was observed that the Cortex phellodendri had the strongest inhibitory effects, followed by the S. flavescens. In the future, these Chinese herbal medicines are expected to be used to treat the fungal infections related to C. glabrata in poultry to improve production performance.


Assuntos
Candida glabrata , Medicamentos de Ervas Chinesas , Animais , Antibacterianos/farmacologia , Doenças das Aves/tratamento farmacológico , Doenças das Aves/microbiologia , Candida glabrata/classificação , Candida glabrata/efeitos dos fármacos , Candida glabrata/isolamento & purificação , Columbidae/microbiologia , Medicamentos de Ervas Chinesas/farmacologia , Testes de Sensibilidade Microbiana/veterinária
15.
Reprod Fertil Dev ; 22(7): 1148-58, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20797353

RESUMO

The ovarian sympathetic nerves participate in the regulation of mammalian ovarian function, but it is still not known whether the neonatal ovarian sympathetic nerve is involved in follicular development and related mechanisms. In the present study, the superior ovarian nerve (SON) of the neonatal rat was transected on postnatal day (PD) 2, and follicle development, ovarian hormone secretion, ovulation rate, granulosa cell proliferation and apoptosis were analysed on PD 30 and PD 90. The results demonstrate that SON transection decreases follicle number and size, reduces ovulation induced by gonadotrophin and enhances follicular atresia. Bromodeoxyuridine (BrdU) and cleaved caspase-3 immunohistochemistry staining provide evidence that SON transection inhibits granulosa cell proliferation and promotes granulosa cell apoptosis. In addition, SON transection increases serum oestradiol levels, but has no influence on serum progesterone levels. These results suggest that the sympathetic nerve supply to the ovaries is important in regulating follicle development and ovary function. These results are critical for further understanding of the neuroendocrine regulation of ovary development and function, although the mechanism needs to be elucidated in future studies.


Assuntos
Atresia Folicular/fisiologia , Células da Granulosa/fisiologia , Folículo Ovariano/fisiologia , Sistema Nervoso Simpático/fisiologia , Animais , Animais Recém-Nascidos , Apoptose/fisiologia , Contagem de Células/veterinária , Proliferação de Células , Estradiol/sangue , Feminino , Imuno-Histoquímica/veterinária , Folículo Ovariano/citologia , Folículo Ovariano/inervação , Ovulação/fisiologia , Progesterona/sangue , Ratos , Ratos Wistar
16.
Environ Monit Assess ; 163(1-4): 337-45, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19267207

RESUMO

A high PM(10) episode observed at a coastal site nearby Shanghai during 18-19 January 2007 was analyzed in this study. The maximum hourly averaged PM(10) concentrations for the 2 days were 0.58 and 0.62 mg/m(3), respectively. The meteorological condition during the episode was favorable for air pollution with large-scale stagnation. There was no dispersing effect by high wind, no scavenging function by precipitation, and no diluting process by clean marine air during the episode. The trajectories for 16-19 January all came from the northern region and kept in low levels, and during the episode peak time, from the morning of 18 to the morning of 19 January, trajectories all came from the northern inland areas and had passed over the coastal region of Jiangsu province before arriving at the site. The variation of the air pollution indexes (APIs) in the cities located in the upwind direction of the site during the episode days clearly shows a process of large-scale air pollution from north to south. The liner correlation coefficient for PM(10) and SO(2) concentrations is 0.774 during the episode, while for PM(10) and CO, it even reaches 0.995, which indicated that the high PM(10) was mainly emitted from the coal burning for domestic heating in winter. Therefore, the observed episode was caused by the transport of domestic heating pollutants accumulated in the boundary layer from northern continental areas.


Assuntos
Poluentes Atmosféricos/análise , China , Tamanho da Partícula , Chuva
17.
Dalton Trans ; 49(6): 1736-1741, 2020 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-31967147

RESUMO

Platinum(iv) complexes with a heterocyclic ligand and an ancillary ligand have been investigated and applied for treating various tumour cell lines. Another application of the Pt(iv) complexes in forming peptide disulfide bonds was investigated in this work. For development of Pt(iv) complex chemistry for disulfide bond formation in peptides, two Pt(iv) complexes, [PtCl2(phen)(en)]Cl2 and [PtCl2(bpy)(en)]Cl2, were synthesized and characterized using elemental analysis, ESI-MS and NMR. Subsequently, they were investigated as oxidants for the formation of disulfide bonds in various peptides. Excellent purities and yields of disulfide-containing peptides were achieved when the reactions were carried out in aqueous solution. The reactions were completed rapidly in a wide range of pH values even in acidic medium at room temperature. An intramolecular disulfide bond was formed in each of the peptides in a solution containing two dithiol-containing peptides, making the Pt(iv) complexes useful for generating disulfide-containing peptide libraries. In addition, the two Pt(iv) complexes can be used as oxidants for the synthesis of disulfide bonds on a resin, which is a more convenient method to synthesize disulfide-containing peptides through automation.


Assuntos
Complexos de Coordenação/química , Dissulfetos/química , Compostos Organoplatínicos/química , Peptídeos/química , Técnicas de Química Sintética , Complexos de Coordenação/síntese química , Dissulfetos/síntese química , Ligantes , Compostos Organoplatínicos/síntese química , Peptídeos/síntese química , Platina/química
18.
Poult Sci ; 99(9): 4530-4538, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32867997

RESUMO

In this study, a strain of Trichosporon was isolated from white pseudomembranes and ulcers formed on mucous membranes of pigeon bursas and was identified through gene sequencing. Bacteriostatic actions of Acorus gramineus, Sophora flavescens, Polygonum hydropiper, and Chinese herbal mixture on this species were explored in vitro, and the minimum inhibitory concentration of herbal medicines against Trichosporon was determined through microdilution method. Therapeutic effects of herbal medicines on chickens infected by Trichosporon were studied, whose results showed that minimum inhibitory concentration of A. gramineus was 32 µg/µL, that of S. flavescens was 2 µg/µL, that of P. hydropiper was 120 µg/µL, and that of Chinese herbal mixture was 36 µg/µL. Antibacterial effects of S. flavescens were the best. In accordance with animal experiments, therapeutic effects of Chinese herbal medicines on infected chickens were better than those of fluconazole. The mortality rate of the Chinese herbal medicine treatment group was 33.33%, that of the fluconazole treatment group was 46.67%, and that of the Chinese medicine protection group was 23.33%. The longer the time of Chinese medicine treatments was, the better the treatment effects would be. Glutamic oxaloacetylase values of the serum and liver in the Chinese herbal medicine treatment group were both significantly lower than those of the nontreatment group. From the results, it can be seen that A. gramineus, S. flavescens, P. hydropiper, and Chinese herbal mixture have certain inhibitory effects on Trichosporon spp. Chinese herbal medicine protections in advance could reduce Trichosporon infections.


Assuntos
Galinhas , Medicamentos de Ervas Chinesas , Trichosporon , Tricosporonose , Animais , Medicamentos de Ervas Chinesas/farmacologia , Medicamentos de Ervas Chinesas/uso terapêutico , Testes de Sensibilidade Microbiana/veterinária , Trichosporon/efeitos dos fármacos , Tricosporonose/tratamento farmacológico , Tricosporonose/veterinária
19.
Poult Sci ; 99(5): 2757-2765, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32359613

RESUMO

In the present study, for the purpose of investigating the effects of the total flavonoids of Epimedium (TFE) in regard to preventing the development of atrophied oviducts and follicles induced by forced molting, 300-day-old Hy-Line Brown layer hens were divided into 3 study groups as follows: the control (CON) group was the normal group, without forced molting and TFE treatments; the TFE1 group was treated by adding a 1‰ TFE treatment after forced molting; and the TFE0 group was not treated by TFE after forced molting. During this study's experimental process, the egg production rates were recorded each day. In addition, the hens were randomly chosen to be weighed every 4 D and also randomly selected to be sacrificed every 7 D. Then, sample tissues of albumen-secreting part and uterus from the fallopian tube of the layer hens were collected for PCR and hematoxylin-eosin staining tests. The results showed that the body weights, number of follicles, and weights and sizes of the fallopian tube for the TFE1 and TFE0 groups were significantly reduced when compared with those of the control group on the 15th D of the experiment. Furthermore, at the end of study, it was found that the egg production rates, weights of the fallopian tube, and ovarian follicles of TFE1 had recovered to normal levels. At the same time, the serum estrogen and the expressions of the progesterone receptor and estrogen receptor mRNA in fallopian tube were higher than those observed for the TFE0 group. The results of this study provided valuable evidence that TFE could improve the development of atrophied oviducts and increase the egg laying rates, thereby making it a potential multicomponent natural drug for egg production in the future.


Assuntos
Proteínas Aviárias/metabolismo , Galinhas/metabolismo , Epimedium/química , Tubas Uterinas/efeitos dos fármacos , Flavonoides/metabolismo , Folículo Ovariano/efeitos dos fármacos , Reprodução/efeitos dos fármacos , Animais , Estrogênios/metabolismo , Tubas Uterinas/crescimento & desenvolvimento , Feminino , Flavonoides/administração & dosagem , Muda , Folículo Ovariano/crescimento & desenvolvimento , RNA Mensageiro/metabolismo , Receptores de Estrogênio/metabolismo , Receptores de Progesterona/metabolismo
20.
Poult Sci ; 99(9): 4598-4606, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32868004

RESUMO

To investigate the impact of total flavonoids of Epimedium (TFE) on the development of follicles of laying hens, 3 types of follicles including primary, prehierarchical, and preovulatory follicles were selected to obtain the follicular granulosa cells cultured in vitro. First, extraction of TFE was conducted by alcohol-soluble and ultrasonic methods. The effects of TFE on activity and proliferation of follicular granulosa cells were detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and measuring the expression of proliferating cell nuclear antigen mRNA through real-time quantitative polymerase chain reaction, and the expression of the follicle-stimulating hormone receptor, luteinizing hormone receptor, steroidogenic acute regulatory protein, and cytochrome P450 family 11 subfamily A member 1 mRNA was detected to study the functions of TFE affecting the differentiation and hormone secretion by granulosa cells. The results showed that TFE significantly improved the proliferation of 3 types of granulosa cells and promoted the differentiation of granulosa cells and accelerated the conversion of primary follicles to prehierarchical follicles. Total flavonoids of Epimedium played an important role in promoting progesterone secretion by prehierarchical and preovulatory granulosa cells. The results indicated that TFE could promote proliferation and differentiation of follicular granulosa cells and improve hormone secretion and follicle development, which provided reference data for TFE used as a feed additive or safe Chinese veterinary medicine to promote the laying rate.


Assuntos
Diferenciação Celular , Galinhas , Epimedium , Flavonoides , Células da Granulosa , Animais , Diferenciação Celular/efeitos dos fármacos , Galinhas/crescimento & desenvolvimento , Epimedium/química , Feminino , Flavonoides/farmacologia , Células da Granulosa/citologia , Células da Granulosa/efeitos dos fármacos
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