Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 148
Filtrar
Más filtros

País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Crit Rev Biotechnol ; : 1-17, 2024 May 06.
Artículo en Inglés | MEDLINE | ID: mdl-38710624

RESUMEN

Constipation is a common gastrointestinal condition, which may occur at any age and affects countless people. The search for new treatments for constipation is ongoing as current drug treatments fail to provide fully satisfactory results. In recent years, probiotics have attracted much attention because of their demonstrated therapeutic efficacy and fewer side effects than pharmaceutical products. Many studies attempted to answer the question of how probiotics can alleviate constipation. It has been shown that different probiotic strains can alleviate constipation by different mechanisms. The mechanisms on probiotics in relieving constipation were associated with various aspects, including regulation of the gut microbiota composition, the level of short-chain fatty acids, aquaporin expression levels, neurotransmitters and hormone levels, inflammation, the intestinal environmental metabolic status, neurotrophic factor levels and the body's antioxidant levels. This paper summarizes the perception of the mechanisms on probiotics in relieving constipation and provides some suggestions on new research directions.

2.
Mol Ther ; 31(3): 825-846, 2023 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-36638800

RESUMEN

Blindness caused by advanced stages of inherited retinal diseases and age-related macular degeneration are characterized by photoreceptor loss. Cell therapy involving replacement with functional photoreceptor-like cells generated from human pluripotent stem cells holds great promise. Here, we generated a human recombinant retina-specific laminin isoform, LN523, and demonstrated the role in promoting the differentiation of human embryonic stem cells into photoreceptor progenitors. This chemically defined and xenogen-free method enables reproducible production of photoreceptor progenitors within 32 days. We observed that the transplantation into rd10 mice were able to protect the host photoreceptor outer nuclear layer (ONL) up to 2 weeks post transplantation as measured by full-field electroretinogram. At 4 weeks post transplantation, the engrafted cells were found to survive, mature, and associate with the host's rod bipolar cells. Visual behavioral assessment using the water maze swimming test demonstrated visual improvement in the cell-transplanted rodents. At 20 weeks post transplantation, the maturing engrafted cells were able to replace the loss of host ONL by extensive association with host bipolar cells and synapses. Post-transplanted rabbit model also provided congruent evidence for synaptic connectivity with the degenerated host retina. The results may pave the way for the development of stem cell-based therapeutics for retina degeneration.


Asunto(s)
Células Madre Pluripotentes , Degeneración Retiniana , Humanos , Ratones , Animales , Conejos , Laminina/genética , Retina , Células Fotorreceptoras , Degeneración Retiniana/genética , Degeneración Retiniana/terapia , Diferenciación Celular
3.
J Basic Microbiol ; 64(3): e2300365, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38012466

RESUMEN

The chlamydospores of Duddingtonia flagrans are an essential survival and reproductive structure and also an effective ingredient for the biocontrol of parasitic nematodes in livestock. In this study, entering and exiting dormancy conditions and predatory activity of the fungal chlamydospores were conducted. During this fungal growth process, the cultivation time is negatively correlated with spore germination rates. After the spores were processed by vacuum drying for 168 h, their germination rate dropped to 0.94%. In contrast, the percentage of living spores remained 54.82%, suggesting that the spores entered structural dormancy in the arid environment. Meanwhile, the efficacies of the spore against Haemonchus contortus larvae were 93.05% (0 h), 92.19% (16 h), 92.77% (96 h), and 86.45% (168 h), respectively. After dormant spores were stored at 4°C, -20°C, and 28°C (RH90 ~ 95%) for 7 days, their germination rate began to increase significantly (p < 0.05). For in vitro predation assay under the condition of 28°C (RH90 ~ 95%), the predation rate was significantly higher on the 7th day after incubation than that on the 3rd day (p < 0.05). During the period when spores were stored at room temperature for 8 months, their germination rate decreased in the first 5 months and then increased slowly to reach a peak in the 7th month. However, the reduction rate of H. contortus L3 in feces captured by spores remained above 71% for the first 7 months. These results will help us increase the end products yield and the quality of biological control of parasitic nematodes in livestock.


Asunto(s)
Ascomicetos , Duddingtonia , Haemonchus , Animales , Conducta Predatoria , Control Biológico de Vectores/métodos , Haemonchus/microbiología , Heces/microbiología , Esporas Fúngicas , Larva/microbiología
4.
J Basic Microbiol ; 64(1): 32-41, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37699751

RESUMEN

The morphological and structural differences of different types of chlamydospore of Arthrobotrys flagrans, a nematophagous fungus, were studied under light microscope and electron microscope to provide a reference for the biological control of parasitic nematodiasis. In this study, A. flagrans isolate F088 dormant chlamydospore and nondormant chlamydospore were selected as the research objects. The structural differences of these spores were observed by optical microscopy through lactol cotton blue, Trypan blue, and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) staining. FunXite -1, 4',6-diamidino-2-phenylindole, and calcofluor white staining were used to observe the metabolic activity, cell wall, and nucleus differences of the two types of spores under fluorescence microscope. Ultrastructure of the two kinds of spores was observed using scanning electron microscope (SEM) and transmission electron microscope (TEM). Since lacto phenol cotton blue, trypan blue staining cannot distinguish dormant spores from dead spores, MTT assay was performed. Fluorescence microscopy observation showed that the cytoplasmic metabolic activity of nondormant spores was stronger than that of dormant spores. The nucleus of dormant spores was bright blue, and their fluorescence was stronger than that of nondormant spores. The cell wall of nondormant spores produced stronger yellow-green fluorescence than that of dormant spores. Ultrastructural observation showed that there were globular protuberances on the surface of the two types of spores but with no significant difference between them. The inner wall of dormant spore possesses a thick zona pellucida with high electron density which was significantly thicker than that of nondormant spores, and their cytoplasm is also changed. In this study, the microstructure characteristics of dormant and nondormant chlamydospores of A. flagrans fungi were preliminarily clarified, suggesting that the state of cell wall and intracellular materials were changed after spores entered to dormancy.


Asunto(s)
Ascomicetos , Azul de Tripano , Esporas Fúngicas , Heces/microbiología , Control Biológico de Vectores
5.
J Basic Microbiol ; 64(7): e2400008, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38548685

RESUMEN

Arthrobotrys flagrans, a nematode-eating fungus, is an effective component of animal parasitic nematode biocontrol agents. In the dried formulation, the majority of spores are in an endogenous dormant state. This study focuses on dormant chlamydospore and nondormant chlamydospore of A. flagrans to investigate the differences in cyclic adenosine monophosphate (cAMP) and protein content between the two types of spores. cAMP and soluble proteins were extracted from the nondormant chlamydospore and dormant chlamydospore of two isolates of A. flagrans. The cAMP Direct Immunoassay Kit and Bradford protein concentration assay kit (Coomassie brilliant blue method) were used to detect the cAMP and protein content in two types of spores. Results showed that the content of cAMP in dormant spores of both isolates was significantly higher than that in nondormant spores (p < 0.05). The protein content of dormant spores in DH055 bacteria was significantly higher than that of nondormant spores (p < 0.05). In addition, the protein content of dormant spores of the SDH035 strain was slightly higher than that of nondormant spores, but the difference was not significant (p > 0.05). The results obtained in this study provide evidence for the biochemical mechanism of chlamydospore dormancy or the germination of the nematophagous fungus A. flagrans.


Asunto(s)
AMP Cíclico , Proteínas Fúngicas , Esporas Fúngicas , Esporas Fúngicas/crecimiento & desarrollo , Proteínas Fúngicas/metabolismo , AMP Cíclico/metabolismo , Ascomicetos/crecimiento & desarrollo , Ascomicetos/química , Ascomicetos/metabolismo , Ascomicetos/aislamiento & purificación , Animales , Nematodos/microbiología
6.
Biochem Biophys Res Commun ; 671: 236-245, 2023 09 03.
Artículo en Inglés | MEDLINE | ID: mdl-37307707

RESUMEN

Metastasis-associated in colon cancer 1 (MACC1) is an oncogene associated with the progression and metastasis of many solid cancer entities. High expression of MACC1 is found in colorectal cancer (CRC) tissues. So far, the role of MACC1 in CRC cell pyroptosis and resistance to irinotecan is unclear. The cleavage of Gasdermin-E (GSDME) is the main executors of activated pyroptosis. We found that GSDME enhanced CRC cell pyroptosis and reduced their resistance to irinotecan, while MACC1 inhibited the cleavage of GSDME and CRC cell pyroptosis, promoted CRC cell proliferation, and enhanced the resistance of CRC cells to irinotecan. Therefore, CRC cells with high MACC1 expression and low GSDME expression had higher resistance to irinotecan, while CRC cells with low MACC1 expression and high GSDME expression had lower resistance to irinotecan. Consistently, by analyzing CRC patients who received FOLFIRI (Fluorouracil + Irinotecan + Leucovorin) in combination with chemotherapy in the GEO database, we found that CRC patients with low MACC1 expression and high GSDME expression had higher survival rate. Our study suggests that the expression of MACC1 and GSDME can be used as detection markers to divide CRC patients into irinotecan resistant and sensitive groups, helping to determine the treatment strategy of patients.


Asunto(s)
Neoplasias Colorrectales , Gasderminas , Humanos , Irinotecán/farmacología , Piroptosis , Neoplasias Colorrectales/tratamiento farmacológico , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/metabolismo , Transactivadores/genética , Transactivadores/metabolismo
7.
Plant Dis ; 2023 Jun 27.
Artículo en Inglés | MEDLINE | ID: mdl-37368448

RESUMEN

Passion fruit (Passilora edulis, family Passifloraceae.) is an economically important fruit crop in many tropical and subtropical regions worldwide. It is widely planting in southern China, and in greenhouses throughout the country. In Mar 2022, symptoms of a viral-like infection were observed on the leaves of passion fruit plants in a 3-hectare greenhouse complex in Hohhot, China. Chlorotic lesions were observed on leaves of two vines of passion fruit and symptomatic leaves developed chlorotic spots, followed by systemic leaf chlorosis and necrosis. Dark ringed spots emerged on the surface of matured fruits (Figure 1). To confirm infectivity, mechanical transmission of the virus was performed by grinding leaves from two symptomatic passion fruit vines in 0.1M phosphate buffer pH 7, and the resulting two samples were each used to rub-inoculate carborundum-dusted leaves of three healthy passion fruit seedlings. Newly emerging leaves of inoculated plants developed mild mosaic symptoms 30-days after inoculation. Three samples from each of the two original symptomatic plants and two samples from each inoculated seedling tested positive using a Passiflora latent virus (PLV) ELISA Kit (Creative Diagnostics, USA). To further confirm the virus identity, total RNA from leaf samples from one of the original greenhouse symptomatic plants and one of the inoculated seedlings were extracted using an TaKaRa MiniBEST Viral RNA Extraction Kit (Takara, Japan). The two RNA samples were subjected to reverse transcription-polymerase chain reaction (RT-PCR) tests with virus specific primers PLV-F (5'-ACACAAAACTGCGTGTTGGA-3') and PLV-R (5'-CAAGACCCACCTACCTCAGTGTG-3') (Cho et al., 2020). RT-PCR products of the expected 571 bp were obtained from both the original greenhouse sample and inoculated seedling. Amplicons were cloned into the pGEM-T Easy Vector, and two clones per sample were Sanger sequenced bidirectionally (Sangon Biotech, China), and the sequence of one clone from one of the original symptomatic sample was uploaded to NCBI (GenBank OP320922.1). This accession had 98% nucleotide sequence identity with a PLV isolate from Korea (GenBank: LC556232.1). RNA extracts from two asymptomatic samples tested negative for PLV with both ELISA and RT-PCR tests. We also tested the original symptomatic sample for common occurring passion fruit viruses, including passion fruit woodiness virus (PWV), cucumber mosaic virus (CMV), east asian passiflora virus (EAPV), telosma mosaic virus (TeMV), papaya leaf curl Guangdong virus (PaLCuGdV), and the RT-PCR results were negative for those viruses. However, based on the systemic leaf chlorosis and necrosis symptoms, we cannot preclude a mixed infestation of other viruses. PLV affects fruit quality and has high potential to reduce market value. To our knowledge, this is the first report of PLV in China, which could provide a reference basis to PLV identification, prevention and control. Acknowledgments This research was carried out with the support of Inner Mongolia Normal University High-level Talents Scientific Research Startup Project (Grant no. 2020YJRC010). Supplementary material Figure 1. Mottle, leaf distortion, puckering symptoms on old leaf (A), mild puckering symptom on young leaf (B), and ring-striped spots symptoms on fruit (C) of the PLV infected passion fruit plant in China.

8.
Int J Mol Sci ; 23(18)2022 Sep 06.
Artículo en Inglés | MEDLINE | ID: mdl-36142120

RESUMEN

High-temperature requirement A1 (HtrA1) has been identified as a disease-susceptibility gene for age-related macular degeneration (AMD) including polypoidal choroidal neovasculopathy (PCV). We characterized the underlying phenotypic changes of transgenic (Tg) mice expressing ubiquitous CAG promoter (CAG-HtrA1 Tg). In vivo imaging modalities and histopathology were performed to investigate the possible neovascularization, drusen formation, and infiltration of macrophages. Subretinal white material deposition and scattered white-yellowish retinal foci were detected on CFP [(Tg­33% (20/60) and wild-type (WT)­7% (1/15), p < 0.05]. In 40% (4/10) of the CAG-HtrA1 Tg retina, ICGA showed punctate hyperfluorescent spots. There was no leakage on FFA and OCTA failed to confirm vascular flow signals from the subretinal materials. Increased macrophages and RPE cell migrations were noted from histopathological sections. Monocyte subpopulations were increased in peripheral blood in the CAG-HtrA1 Tg mice (p < 0.05). Laser induced CNV in the CAG-HtrA1 Tg mice and showed increased leakage from CNV compared to WT mice (p < 0.05). Finally, choroidal explants of the old CAG-HtrA1 Tg mice demonstrated an increased area of sprouting (p < 0.05). Signs of subclinical inflammation was observed in CAG-HtrA1 Tg mice. Such subclinical inflammation may have resulted in increased RPE cell activation and angiogenic potential.


Asunto(s)
Neovascularización Coroidal , Degeneración Macular , Animales , Coroides/irrigación sanguínea , Neovascularización Coroidal/genética , Neovascularización Coroidal/patología , Serina Peptidasa A1 que Requiere Temperaturas Altas/genética , Inflamación/genética , Inflamación/patología , Degeneración Macular/genética , Degeneración Macular/patología , Ratones , Ratones Transgénicos , Retina/patología
9.
Angew Chem Int Ed Engl ; 61(40): e202208174, 2022 Oct 04.
Artículo en Inglés | MEDLINE | ID: mdl-35960211

RESUMEN

Here we report a new type of chiral all-carbon tetrasubstituted VQMs generated via chiral phosphoric acids catalyzed nucleophilic addition of 2-alkynylnaphthols to o-quinone methides or imines, which can be captured intramolecularly as a result of cycloaddition reaction. A new class of naphthyl-2H-chromenes bearing axially and centrally chiral elements and axially chiral quinone-naphthols were prepared efficiently with good to excellent yields, diastereoselectivities and enantioselectivities. Noteworthy, the enantioselective cycloaddition of alkynylnaphthols with o-quinone methides proceeded via a [2+2] cycloaddition, followed by a retro-4π-electrocyclization and a 6π re-cyclization. While the cycloaddition of alkynylnaphthols with imines proceeded via a sequential [2+4] cycloaddition and an auto oxidation reaction. Moreover, the obtained axially chiral naphthols can be converted into valuable phosphine ligands and other functional molecules.

10.
Artículo en Inglés | MEDLINE | ID: mdl-33361304

RESUMEN

Candida endophthalmitis is a serious sight-threatening complication of candidemia that may occur before or during antifungal therapy. Hematogenous Candida meningoencephalitis (HCME) is also a serious manifestation of disseminated candidiasis in premature infants, immunosuppressed children, and immunocompromised adults. We evaluated the antifungal efficacy and pharmacokinetics of the prodrug fosmanogepix (APX001) in a rabbit model of endophthalmitis/HCME. Manogepix (APX001A), the active moiety of prodrug fosmanogepix, inhibits the fungal enzyme Gwt1 and is highly active in vitro and in vivo against Candida spp., Aspergillus spp., and other fungal pathogens. Plasma pharmacokinetics of manogepix after oral administration of fosmanogepix on day 6 at 25, 50, and 100 mg/kg resulted in maximum concentration of drug in plasma (Cmax) of 3.96 ± 0.41, 4.14 ± 1.1, and 11.5 ± 1.1 µg/ml, respectively, and area under the concentration-time curve from 0 to 12 h (AUC0-12) of 15.8 ± 3.1, 30.8 ± 5.0, 95.9 ± 14 µg·h/ml, respectively. Manogepix penetrated the aqueous humor, vitreous, and choroid with liquid-to-plasma ratios ranging from 0.19 to 0.52, 0.09 to 0.12, and 0.02 to 0.04, respectively. These concentrations correlated with a significant decrease in Candida albicans burden in vitreous (>101 to 103 log CFU/g) and choroid (>101 to 103 log CFU/g) (P ≤ 0.05 and P ≤ 0.001, respectively). The aqueous humor had no detectable C. albicans in treatment and control groups. The tissue/plasma concentration ratios of manogepix in meninges, cerebrum, cerebellum, and spinal cord were approximately 1:1, which correlated with a >102 to 104 decline of C. albicans in tissue versus control (P ≤ 0.05). Serum and cerebrospinal fluid (CSF) (1→3)-ß-d-glucan levels demonstrated significant declines in response to fosmanogepix treatment. These findings provide an experimental foundation for fosmanogepix in treatment of Candida endophthalmitis and HCME and derisk the clinical trials of candidemia and invasive candidiasis.


Asunto(s)
Endoftalmitis , Meningoencefalitis , Animales , Antifúngicos/uso terapéutico , Candida , Candida albicans , Endoftalmitis/tratamiento farmacológico , Meningoencefalitis/tratamiento farmacológico , Pruebas de Sensibilidad Microbiana , Conejos
11.
Biotechnol Bioeng ; 118(7): 2503-2513, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-33755193

RESUMEN

Morphology plays an important role in fungal fermentation and secondary metabolites biosynthesis. One novel technique, microparticle-enhanced cultivation was successfully utilized to control the morphology of Monascus purpureus precisely and enhance the yield of yellow pigments. The production of yellow pigments increased to 554.2 U/ml when 4 g/L 5000 mesh talc added at 24 h. Field emission scanning electron microscope observation indicated that the actual effect depends on the properties of microparticle. Sharp-edged microparticles showed better stimulatory effects than smooth, round-shaped ones. Particle size analysis, scanning electron microscope, and cell integrity evaluation proved obvious morphological changes were induced by talc addition, including smaller mycelial size, rougher hyphae, and decreased cell integrity. Furthermore, the expression levels of MrpigG, MrpigD, MrpigE, and MrpigH were significantly upregulated by the addition of talc. It indicated that the microparticle could not only affect the mycelial morphology, but also influence the expression levels of key genes in biosynthetic pathway of Monascus yellow pigments.


Asunto(s)
Regulación Fúngica de la Expresión Génica , Hifa/crecimiento & desarrollo , Monascus/crecimiento & desarrollo , Pigmentos Biológicos/biosíntesis
12.
J Org Chem ; 86(24): 17673-17683, 2021 12 17.
Artículo en Inglés | MEDLINE | ID: mdl-34865471

RESUMEN

An effective Sc-catalyzed transfer hydrogenation and cyclization tandem reaction has been achieved. This process showed excellent functional group compatibility and good yields. A variety of benzoxazines were produced with primary or secondary alcohols as a hydrogen source. Furthermore, the utility of this newly developed protocol is demonstrated through scaled-up experiment, late-stage modification, and preliminary exploration of enantioselective synthesis.


Asunto(s)
Alcoholes , Acetofenonas , Benzaldehídos , Catálisis , Ciclización , Hidrogenación , Mesilatos , Estructura Molecular , Escandio
13.
Med Mycol ; 59(2): 189-196, 2021 Feb 04.
Artículo en Inglés | MEDLINE | ID: mdl-33313821

RESUMEN

Treatment options for Exserohilum rostratum meningoencephalitis and other causes of phaeohyphomycosis of the central nervous system (CNS) are limited, while mortality and morbidity remain high. We therefore evaluated isavuconazole, a new antifungal triazole in comparison to liposomal amphotericin B (LAMB), in vitro and in the rabbit model of Exserohilum rostratum meningoencephalitis. We hypothesized that isavuconazole alone or in combination with LAMB or micafungin may be alternative options for treatment of CNS phaeohyphomycosis. We therefore investigated the in vitro antifungal activity of isavuconazole alone or in combination with amphotericin B deoxycholate (DAMB) or micafungin and efficacy of treatment with isavuconazole and LAMB in a rabbit model of experimental E. rostratum meningoencephalitis. Combination checkerboard plates were used to determine the minimum inhibitory concentrations, minimal lethal concentrations, fractional inhibitory concentration indices, and Bliss surface analysis of isavuconazole and amphotericin B deoxycholate (DAMB), either alone or in combination. As there were no in vitro synergistic or antagonistic interactions for either combination of antifungal agents against the E. rostratum isolates, in vivo studies were conducted with isavuconazole and LAMB as monotherapies. Rabbits were divided in following groups: treated with isavuconazole at 60 mg/kg/d (ISAV60), LAMB at 5.0 (LAMB5), 7.5 (LAMB7.5), and 10 mg/kg/d (LAMB10), and untreated controls (UC). In ISAV60-, LAMB5-, LAMB7.5-, and LAMB10-treated rabbits, significant reductions of fungal burden of E. rostratum in cerebral, cerebellar, and spinal cord tissues (P < 0.01) were demonstrated in comparison to those of UC. These antifungal effects correlated with significant reduction of CSF (1→3)-ß-D-glucan levels vs UC (P < 0.05). These data establish new translational insights into treatment of CNS phaeohyphomycosis.


Asunto(s)
Anfotericina B/uso terapéutico , Antifúngicos/uso terapéutico , Ascomicetos/efectos de los fármacos , Enfermedades del Sistema Nervioso Central/tratamiento farmacológico , Nitrilos/uso terapéutico , Feohifomicosis/tratamiento farmacológico , Piridinas/uso terapéutico , Triazoles/uso terapéutico , Anfotericina B/farmacología , Animales , Antifúngicos/farmacología , Ascomicetos/patogenicidad , Enfermedades del Sistema Nervioso Central/microbiología , Manejo de la Enfermedad , Modelos Animales de Enfermedad , Quimioterapia Combinada , Femenino , Humanos , Pruebas de Sensibilidad Microbiana , Nitrilos/farmacología , Piridinas/farmacología , Conejos , Triazoles/farmacología
14.
Zhonghua Nan Ke Xue ; 27(2): 167-171, 2021 Feb.
Artículo en Zh | MEDLINE | ID: mdl-34914335

RESUMEN

Androgen plays a significant role in the development and progression of prostate cancer (PCa), one of the commonest malignancies in the male urogenital system. Castration-resistant PCa (CRPC) is the end-result of the majority of prostate cancer cases treated by androgen deprivation therapy (ADT). Furthermore, the androgen axis is reactivated due to adaptive intratumoral androgen biosynthesis, which can be driven by adrenal androgens and /or by changes in the androgen receptor (AR) including AR gene amplification. At present, drugs targeting the androgen axis, such as abiraterone and enzalutamide, et al, are used for the first-line therapy for CRPC. Nevertheless, drug resistance and disease progression occur during the treatment of CRPC by anti-androgen therapy. Therefore, an insight into the mechanisms of drug resistance in anti-androgen therapy for CRPC may help surmount the drug reistance and improve the prognosis of the malignancy.


Asunto(s)
Neoplasias de la Próstata Resistentes a la Castración , Antagonistas de Andrógenos , Resistencia a Medicamentos , Humanos , Masculino , Neoplasias de la Próstata Resistentes a la Castración/tratamiento farmacológico
15.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 52(5): 799-806, 2021 Sep.
Artículo en Zh | MEDLINE | ID: mdl-34622596

RESUMEN

OBJECTIVE: To explore the preparation method of copper (Cu)-doped hydroxyapatite (HA) microspheres loaded with vancomycin (Van), and evaluate their antibacterial and osteogenic effects in vitro. METHODS: The Cu doped HA microspheres (Cu-HA) with molar doping ratios of 1%, 5%, 10%, and 20% were prepared by hydrothermal synthesis. The microscopic morphology changes were observe with scanning electron microscope. X-ray diffractometer (XRD) was used to study the phase composition and analyze the crystallinity of the sample. Cu-HA with a molar doping ratio of 10% was selected for analysis of the elemental composition of the sample with energy dispersive X-ray spectroscopy (EDS), and was then coated with polydopamine (PDA) as the medium to prepare Cu-HA-PDA. XRD and Fourier infrared spectrometer were used to examine the coating effect of the sample. Van was load on Cu-HA-PDA to prepare Cu-HA-PDA-Van. HA, Cu-HA, HA-PDA, and Cu-HA-PDA-Van were added to α medium at 10 mg/mL to prepare different groups of extract solutions.The main components of the extract solutions were examined, and the Van concentration was checked. We examined the toxic effect of material extract solutions on osteogenic precursor cells and the proliferation and differentiation of bone marrow mesenchymal stem cells, and checked the expression of osteocalcin ( OCN), runt-related transcription factor 2 ( RUNX-2), and alkaline phosphatase ( ALP), the osteogenic related genes. Sterilized HA, Cu-HA, HA-PDA, Cu-HA-PDA, Cu-HA-DPA-Van microsphere materials were prepared, and the colony counting method was used to evaluate the antibacterial effect of the materials for Staphylococcus aureus. RESULTS: Various types of Cu-doped HA (Cu-HA) were successfully synthesized. As the proportion of Cu increased, the morphology gradually changed from being strip or belt-shaped to a uniform spherical shape. Cu-HA of 10% molar doping ratio showed a clearly microspherical shape and a petal-like porous micro-nano morphology on the surface. EDS and XRD analyses showed that the main structure of the material was still made up of hydroxyapatite crystals and Cu was successfully doped with HA. The infrared spectrometer showed that the PDA was successfully coated on the surface of the material. Examination of the main components of the extract solution once again verified that the Cu element had successfully entered and replaced part of the Ca element in the HA. The 10 mg/mL Cu-HA-PDA-Van extract solution contained 0.27 mg/mL of Van. In vitro cell experiments and bone-formation-related gene testing showed that Cu-HA-Van had good biological activity and promoted bone differentiation. The minimum inhibitory concentration (MIC) of Cu-HA-PDA-Van microspheres was 16 µg/mL. Compared with Cu-HA, HA-PDA and pure HA, Cu-HA-Van microspheres had significant and long-lasting antibacterial effects. CONCLUSION: Cu element was used to control the microscopic morphology of HA, and the Cu-HA-PDA-Van microspheres prepared by successfully coating of PDA and loading of Van had good antibacterial properties and biological activity.


Asunto(s)
Antibacterianos , Durapatita , Antibacterianos/farmacología , Cobre , Durapatita/farmacología , Microesferas , Osteogénesis
16.
Artículo en Inglés | MEDLINE | ID: mdl-32179521

RESUMEN

Ibrexafungerp (formerly SCY-078) is a semisynthetic triterpenoid and potent (1→3)-ß-d-glucan synthase inhibitor. We investigated the in vitro activity, pharmacokinetics, and in vivo efficacy of ibrexafungerp (SCY) alone and in combination with antimold triazole isavuconazole (ISA) against invasive pulmonary aspergillosis (IPA). The combination of ibrexafungerp and isavuconazole in in vitro studies resulted in additive and synergistic interactions against Aspergillus spp. Plasma concentration-time curves of ibrexafungerp were compatible with linear dose proportional profile. In vivo efficacy was studied in a well-established persistently neutropenic New Zealand White (NZW) rabbit model of experimental IPA. Treatment groups included untreated control (UC) rabbits and rabbits receiving ibrexafungerp at 2.5 (SCY2.5) and 7.5 (SCY7.5) mg/kg of body weight/day, isavuconazole at 40 (ISA40) mg/kg/day, or combinations of SCY2.5+ISA40 and SCY7.5+ISA40. The combination of SCY+ISA produced an in vitro synergistic interaction. There were significant in vivo reductions of residual fungal burden, lung weights, and pulmonary infarct scores in SCY2.5+ISA40, SCY7.5+ISA40, and ISA40 treatment groups versus those of the SCY2.5-treated, SCY7.5-treated, and UC (P < 0.01) groups. Rabbits treated with SCY2.5+ISA40 and SCY7.5+ISA40 had prolonged survival in comparison to that of the SCY2.5-, SCY7.5-, ISA40-treated, or UC (P < 0.05) groups. Serum galactomannan index (GMI) and (1→3)-ß-d-glucan levels significantly declined in animals treated with the combination of SCY7.5+ISA40 in comparison to those of animals treated with SCY7.5 or ISA40 (P < 0.05). Ibrexafungerp and isavuconazole combination demonstrated prolonged survival, decreased pulmonary injury, reduced residual fungal burden, and lower GMI and (1→3)-ß-d-glucan levels in comparison to those of single therapy for treatment of IPA. These findings provide an experimental foundation for clinical evaluation of the combination of ibrexafungerp and an antimold triazole for treatment of IPA.


Asunto(s)
Aspergilosis Pulmonar Invasiva , Triterpenos , Animales , Antifúngicos/uso terapéutico , Glucanos , Glicósidos , Aspergilosis Pulmonar Invasiva/tratamiento farmacológico , Nitrilos , Piridinas , Conejos , Triazoles
17.
Artículo en Inglés | MEDLINE | ID: mdl-32015048

RESUMEN

Klebsiella pneumoniae carbapenemase-producing Klebsiella pneumoniae (KPC-Kp) is an emerging global public health threat that causes life-threatening pneumonia and bacteremia. Ceftazidime-avibactam (CZA) represents a promising advance for the treatment of serious infections caused by KPC-Kp We investigated the pharmacokinetics and efficacy of ceftazidime-avibactam in the treatment of experimental KPC-Kp pneumonia in persistently neutropenic rabbits. For single-dose and multidose (administration every 8 h) pharmacokinetics, rabbits received ceftazidime-avibactam intravenous infusions at 60/15, 90/22.5, and 120/30 mg/kg of body weight. Ceftazidime mean area under the concentration-time curves (AUCs) ranged from 287 to 608 µg·h/ml for a single dose and from 300 to 781 µg·h/ml for multiple doses. Avibactam AUCs ranged from 21 to 48 µg·h/ml for a single dose and from 26 to 48 µg·h/ml for multiple doses. KPC-Kp pneumonia was established by direct endotracheal inoculation. Treatments consisted of ceftazidime-avibactam at 120/30 mg/kg every 6 h, a polymyxin B (PMB) loading dose of 2.5 mg/kg followed by 1.5 mg/kg every 12 h q12h, or no treatment (untreated controls [UC]). There were significant reductions in the residual bacterial burden, lung weights, and pulmonary hemorrhage scores in CZA- and PMB-treated rabbits for a 7-day or a 14-day (P ≤ 0.01) course in comparison with those in the UC. These results corresponded to significant decreases in the bacterial burden in bronchoalveolar lavage fluid after a 7-day or a 14-day treatment (P ≤ 0.01). The outcomes demonstrated an improved response at 14 days versus that at 7 days. There was significantly prolonged survival in rabbits treated with CZA for 14 days in comparison with that in the PMB-treated or UC rabbits (P ≤ 0.05). This study demonstrates that ceftazidime-avibactam displays linear dose-proportional exposures simulating those seen from human plasma pharmacokinetic profiles, is active for the treatment of experimental KPC-Kp pneumonia in persistently neutropenic rabbits, and provides an experimental foundation for the treatment of severely immunocompromised patients with this life-threatening infection.


Asunto(s)
Antibacterianos/uso terapéutico , Compuestos de Azabiciclo/uso terapéutico , Ceftazidima/uso terapéutico , Infecciones por Klebsiella/tratamiento farmacológico , Klebsiella pneumoniae/efectos de los fármacos , Inhibidores de beta-Lactamasas/uso terapéutico , Animales , Antibacterianos/farmacocinética , Compuestos de Azabiciclo/farmacocinética , Bacteriemia/tratamiento farmacológico , Bacteriemia/microbiología , Carga Bacteriana/efectos de los fármacos , Proteínas Bacterianas/metabolismo , Enterobacteriaceae Resistentes a los Carbapenémicos/efectos de los fármacos , Ceftazidima/farmacocinética , Combinación de Medicamentos , Farmacorresistencia Bacteriana Múltiple/genética , Femenino , Pruebas de Sensibilidad Microbiana , Neutropenia , Neumonía Bacteriana/tratamiento farmacológico , Neumonía Bacteriana/microbiología , Conejos , Inhibidores de beta-Lactamasas/farmacocinética , beta-Lactamasas/metabolismo
18.
Phys Rev Lett ; 124(25): 250601, 2020 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-32639775

RESUMEN

The out-of-time-ordered correlators (OTOC), a fundamental concept for quantifying quantum information scrambling, has recently been suggested to be an order parameter to dynamically detect both equilibrium quantum phase transitions (EQPTs) and dynamical quantum phase transitions (DQPTs). Here we report the first experimental observation of EQPTs and DQPTs in a quantum spin chain via quench dynamics of OTOC on a nuclear magnetic resonance quantum simulator. We observe that the quench dynamics of the OTOC can unambiguously detect the DQPTs and the equilibrium critical point, while conventional order parameters such as the longitudinal magnetization can not. Moreover, we investigate the two-body correlations throughout the quench dynamics, and find that OTOC can extract the equilibrium critical point with higher accuracy and is more robust to decoherence than that of two-body correlation. Our experiment paves a way for experimentally investigating DQPTs through OTOCs and for studying the EQPTs through the nonequilibrium quantum quench dynamics with quantum simulators.

19.
Eur J Nucl Med Mol Imaging ; 47(11): 2525-2532, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-32666395

RESUMEN

BACKGROUND: The novel coronavirus disease 2019 (COVID-19) is an emerging worldwide threat to public health. While chest computed tomography (CT) plays an indispensable role in its diagnosis, the quantification and localization of lesions cannot be accurately assessed manually. We employed deep learning-based software to aid in detection, localization and quantification of COVID-19 pneumonia. METHODS: A total of 2460 RT-PCR tested SARS-CoV-2-positive patients (1250 men and 1210 women; mean age, 57.7 ± 14.0 years (age range, 11-93 years) were retrospectively identified from Huoshenshan Hospital in Wuhan from February 11 to March 16, 2020. Basic clinical characteristics were reviewed. The uAI Intelligent Assistant Analysis System was used to assess the CT scans. RESULTS: CT scans of 2215 patients (90%) showed multiple lesions of which 36 (1%) and 50 patients (2%) had left and right lung infections, respectively (> 50% of each affected lung's volume), while 27 (1%) had total lung infection (> 50% of the total volume of both lungs). Overall, 298 (12%), 778 (32%) and 1300 (53%) patients exhibited pure ground glass opacities (GGOs), GGOs with sub-solid lesions and GGOs with both sub-solid and solid lesions, respectively. Moreover, 2305 (94%) and 71 (3%) patients presented primarily with GGOs and sub-solid lesions, respectively. Elderly patients (≥ 60 years) were more likely to exhibit sub-solid lesions. The generalized linear mixed model showed that the dorsal segment of the right lower lobe was the favoured site of COVID-19 pneumonia. CONCLUSION: Chest CT combined with analysis by the uAI Intelligent Assistant Analysis System can accurately evaluate pneumonia in COVID-19 patients.


Asunto(s)
Betacoronavirus , Infecciones por Coronavirus/diagnóstico por imagen , Aprendizaje Profundo , Pulmón/diagnóstico por imagen , Tomografía Computarizada Multidetector/métodos , Pandemias , Neumonía Viral/diagnóstico por imagen , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Betacoronavirus/aislamiento & purificación , COVID-19 , Prueba de COVID-19 , Niño , Técnicas de Laboratorio Clínico , Infecciones por Coronavirus/diagnóstico , Femenino , Humanos , Modelos Lineales , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , SARS-CoV-2 , Programas Informáticos , Adulto Joven
20.
Chem Biodivers ; 17(2): e1900609, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31916412

RESUMEN

The fruit of Crataegus dahurica Koehne was used to treat the disease of infantile indigestion and dyspepsia as an ethnic medicine and food. As a continuous work on finding the active constituents from the edible herbs, four new biphenyl derivatives (1-4), together with two known compounds (5 and 6), were obtained from the petroleum ether fraction of the fruits of C. dahurica. Their structures were determined by the extensive 1D and 2D NMR spectra and HR-MS spectrometry. Furthermore, the anti-inflammatory activities of all the isolated compounds were investigated, in which compound 4 showed moderately inhibitory effects on NO production in RAW264.7 cells without inducing cytotoxicity.


Asunto(s)
Antiinflamatorios/química , Crataegus/química , Animales , Antiinflamatorios/aislamiento & purificación , Antiinflamatorios/farmacología , Compuestos de Bifenilo/química , Compuestos de Bifenilo/aislamiento & purificación , Compuestos de Bifenilo/farmacología , Supervivencia Celular/efectos de los fármacos , Crataegus/metabolismo , Frutas/química , Frutas/metabolismo , Lipopolisacáridos/toxicidad , Macrófagos/citología , Macrófagos/efectos de los fármacos , Macrófagos/metabolismo , Espectroscopía de Resonancia Magnética , Ratones , Conformación Molecular , Óxido Nítrico/metabolismo , Células RAW 264.7
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA