Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 103
Filtrar
Más filtros

País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
J Nat Prod ; 87(1): 141-151, 2024 01 26.
Artículo en Inglés | MEDLINE | ID: mdl-38128907

RESUMEN

Twelve new austalide meroterpenoids (1-12) were isolated from the endophytic fungus Diaporthe sp. XC1211. Their structures were elucidated by extensive spectroscopic analysis. The absolute configurations of compounds 1, 3, 4, and 6 were established by single-crystal X-ray diffraction, whereas those for the others were established by experimental electronic circular dichroism (ECD) data analysis. Compounds 1-12 represent a rare class of austalides with a 24α-CH3. Compounds 2 and 5 demonstrated potent proliferation inhibitory effects against LPS-induced B cells with IC50 values of 6.7 (SI = 3.6) and 3.8 (SI > 13) µM, respectively. Compounds 2 and 5 decreased the secretion of IL-6 in LPS-induced B cells in a dose-dependent manner.


Asunto(s)
Hongos , Lipopolisacáridos , Estructura Molecular , Lipopolisacáridos/farmacología , Cristalografía por Rayos X , Dicroismo Circular
2.
BMC Vet Res ; 20(1): 40, 2024 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-38297289

RESUMEN

BACKGROUND: mcr-1-positive Escherichia coli has emerged as a significant threat to human health, veterinary health, and food safety in recent years. After the prohibition of colistin as a feed additive in animal husbandry in China, a noticeable reduction in both colistin resistance and the prevalence of mcr-1 was observed in E. coli from animals and humans. OBJECTIVES: To assess the prevalence of the colistin resistance gene mcr-1 and characterize its genetic context in E. coli strains derived from fecal and meat samples from food-producing animals in China. METHODS: A total of 1,353 fecal samples and 836 food samples were collected between 2019 and 2020 in China. E. coli isolates were identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and their susceptibility to colistin were determined using the broth microdilution method. The colistin-resistant E. coli isolates were screened for the presence of mcr by PCR analysis and sequencing. The minimal inhibitory concentrations (MICs) of 15 antimicrobial agents against the mcr-1-positive strains were further tested using the agar dilution method, conjugation assays were performed, and whole genome sequencing was performed using Illumina HiSeq. RESULTS: In total, 1,403 E. coli strains were isolated. Thirteen isolates from chicken meat (n = 7), chickens (n = 3), and pigs (n = 3) were resistant to colistin with MIC values of 4 to 16 mg/L, and carried mcr-1. All mcr-1-positive strains, except for isolate AH20PE105, contained multiple resistance genes and exhibited multidrug-resistant phenotypes. They belonged to 10 sequence types (STs), including a novel ST (ST14521). mcr-1 was located on IncI2 (n = 9), IncX4 (n = 2), and IncHI2 (n = 2) plasmids, which were highly similar to other mcr-1-carrying plasmids sharing the same incompatibility type. Seven mcr-1-carrying plasmids could be successfully conjugally transferred to E. coli C600. CONCLUSIONS: While the low prevalence of mcr-1 (0.93%) identified in this study may not immediately seem alarming, the very emergence of this gene merits attention given its implications for colistin resistance and public health. Hence, ongoing surveillance of mcr-1 in E. coli remains crucial.


Asunto(s)
Proteínas de Escherichia coli , Escherichia coli , Animales , Humanos , Porcinos , Colistina/farmacología , Proteínas de Escherichia coli/genética , Antibacterianos/farmacología , Prevalencia , Pollos/genética , Plásmidos , China/epidemiología , Pruebas de Sensibilidad Microbiana/veterinaria , Farmacorresistencia Bacteriana/genética
3.
Proc Natl Acad Sci U S A ; 118(30)2021 07 27.
Artículo en Inglés | MEDLINE | ID: mdl-34282014

RESUMEN

Asian summer monsoon (ASM) variability and its long-term ecological and societal impacts extending back to Neolithic times are poorly understood due to a lack of high-resolution climate proxy data. Here, we present a precisely dated and well-calibrated tree-ring stable isotope chronology from the Tibetan Plateau with 1- to 5-y resolution that reflects high- to low-frequency ASM variability from 4680 BCE to 2011 CE. Superimposed on a persistent drying trend since the mid-Holocene, a rapid decrease in moisture availability between ∼2000 and ∼1500 BCE caused a dry hydroclimatic regime from ∼1675 to ∼1185 BCE, with mean precipitation estimated at 42 ± 4% and 5 ± 2% lower than during the mid-Holocene and the instrumental period, respectively. This second-millennium-BCE megadrought marks the mid-to late Holocene transition, during which regional forests declined and enhanced aeolian activity affected northern Chinese ecosystems. We argue that this abrupt aridification starting ∼2000 BCE contributed to the shift of Neolithic cultures in northern China and likely triggered human migration and societal transformation.

4.
Chemistry ; 29(44): e202300554, 2023 Aug 04.
Artículo en Inglés | MEDLINE | ID: mdl-37249393

RESUMEN

The field of anion supramolecular chemistry has received more and more attention in recent years. Anions with diverse types and geometries have been widely used for the synthesis of ionic spin crossover (SCO) complexes. This review is devoted to anion effects on the molecular, supramolecular structures and magnetic properties of discrete SCO compounds. Firstly, typical anions used in the synthesis of these compounds are briefly summarized according to their various geometries. This is followed by a collection of representative examples of anion-based SCO compounds, whose SCO properties are analyzed in terms of supramolecular interactions, geometry and charge of anions. In the third part, anion effects on SCO complexes of different kinds of metal centers and ligands are outlined and finally remarks on the synthesis new type of ionic SCO complexes in the future are described.

5.
Antimicrob Agents Chemother ; 66(7): e0007322, 2022 07 19.
Artículo en Inglés | MEDLINE | ID: mdl-35758720

RESUMEN

Metronidazole (Met) is the first choice for treating Helicobacter pylori (Hp). However, Hp is easy to resistant, making Met unable to be widely used. How to overcome Hp's Met resistance is still an issue. In this study, Met was used as the primary raw material with linolenic acid to prepare a novel compound-linolenic acid-metronidazole (Lla-Met). The MIC, minimum bactericidal concentration (MBC), colonization amount of Hp in gastric mucosa, etc., were evaluated, respectively. Lla-Met was successfully prepared by the detection of nuclear magnetic resonance, etc., and its MIC and MBC to Hp were 2~4 µg/mL, 8~16 µg/mL. Moreover, in vivo experiments, Lla-Met significantly reduced the colonization of drug-resistant Hp in gastric mucosa. In the toxicity test, Lla-Met inhibited rate to GES-1 and BGC823 cells were 15% at 128 µg/mL; the mice were administered 10 times treatment Lla-Met treatment (240 mg/kg), have no difference significant injuries were found in their stomach, liver, spleen, kidney, and weight. In addition, Hp G27 continued for 18 days in vitro with sub-Lla-Met concentration, G27 did not show drug resistance to Lla-Met; Lla-Met did not exert an effect on non-Hp species with 128 µg/mL; Compared with a neutral environment, when the acid concentration is 3.0, Lla-Met is not decomposed and has better stability. Conclusion: Lla-Met, a newly prepared compound, has relatively well antibacterial of Met-resistant and sensitive Hp, with a capability of overcoming the metronidazole resistance of Hp.


Asunto(s)
Infecciones por Helicobacter , Helicobacter pylori , Animales , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Claritromicina/farmacología , Resistencia a Medicamentos , Infecciones por Helicobacter/tratamiento farmacológico , Infecciones por Helicobacter/microbiología , Metronidazol/farmacología , Metronidazol/uso terapéutico , Ratones , Ácido alfa-Linolénico/farmacología
6.
Acta Clin Croat ; 61(2): 193-197, 2022 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-36818924

RESUMEN

The aim was to investigate detection of pulmonary alveolar lavage fluid tuberculosis DNA by real-time fluorescent polymerase chain reaction (RT-PCR) combined with clinical application of the sputum smear-negative pulmonary tuberculosis diagnosis with TB interferon-γ release assay (TB-IGRA). From October 2014 to October 2015, 632 outpatients and inpatients treated in our hospital were randomly selected, of which 459 patients as the research group managed with RT-PCR detection combined with TB-IGRA and 173 patients as the control group undergoing electronic bronchoscopy alveolar lavage fluid detection, with detection results statistically evaluated. The positive rate in the research group was 96.51%, i.e. significantly higher than that in the control group (66.47%), yielding a statistically significant difference (χ2=109.68, p=0.00). The true positive rate was 97.7% in the research group and 67.92% in the control group; the true positive rate was significantly higher in the research group patients as compared with the control group, yielding a statistically significant difference (χ2=112.04, p=0.00). The sensitivity and specificity, as well as Youden index were significantly higher in the research group as compared with the control group. In conclusion, TB DNA detection by RT-PCR combined with TB-IGRA is a very good method of diagnosing tuberculosis, and it can be implemented in clinical diagnosis of pulmonary tuberculosis.


Asunto(s)
Mycobacterium tuberculosis , Tuberculosis Pulmonar , Tuberculosis , Humanos , Ensayos de Liberación de Interferón gamma/métodos , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Esputo , Tuberculosis/diagnóstico , Tuberculosis Pulmonar/diagnóstico , Sensibilidad y Especificidad , ADN
7.
Molecules ; 26(21)2021 Nov 06.
Artículo en Inglés | MEDLINE | ID: mdl-34771127

RESUMEN

Qingzhuan tea (QZT) is a typical Chinese dark tea that has a long-time manufacturing process. In the present study, liquid chromatography coupled with tandem mass spectrometry was used to study the chemical changes of tea samples during QZT processing. Untargeted metabolomics analysis revealed that the pile-fermentation and turnover (post-fermentation, FT) was the crucial stage in transforming the main compounds of QZT, whose contents of flavan-3-ols and flavonoids glycosides were decreased significantly. The bioactivities, including the antioxidant capacities and inhibitory effects on α-amylase and α-glucosidase, were also reduced after the FT process. It was suggested that although the QZT sensory properties improved following pile-fermentation and aging, the bioactivities remained restrained. Correlation analysis indicated that the main galloylated catechins and flavonoid glycosides were highly related to their antioxidant capacity and inhibitory effects on α-amylase and α-glucosidase.


Asunto(s)
Antioxidantes/metabolismo , Bioensayo , Inhibidores de Glicósido Hidrolasas/metabolismo , Metabolómica , Té/metabolismo , Antioxidantes/química , Antioxidantes/farmacología , China , Flavonoides/química , Flavonoides/metabolismo , Flavonoides/farmacología , Inhibidores de Glicósido Hidrolasas/química , Inhibidores de Glicósido Hidrolasas/farmacología , Glicósidos/química , Glicósidos/metabolismo , Glicósidos/farmacología , Té/química , alfa-Amilasas/antagonistas & inhibidores , alfa-Amilasas/metabolismo , alfa-Glucosidasas/metabolismo
8.
Bull Environ Contam Toxicol ; 106(3): 507-515, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33559032

RESUMEN

Heavy metal contamination of soil is of increasing concern because of its potential risk to human health. In this study, two AMFs (Rhizophagus intraradices and Funneliformis mosseae) substantially increased the biomass of bashfulgrass in Zn-contaminated soil, even at Zn levels of up to 600 mg kg-1. Zn uptake in R. intraradices- and F. mosseae-mycorrhizal bashfulgrass was increased by 40-fold and 7-fold, respectively, when plants grown in Zn-contaminated (400 mg kg-1) soil. Elemental analysis showed that neither AMF had an effect on Zn concentration in plant tissues, including the roots and shoots. However, a significant increase of phosphorus (P) concentration was observed, suggesting the increased is from the improved use efficiency of soil nutrients by AMFs. Comparing the two AMFs, better growth performance with more biomass occurred with R. intraradices-inoculated bashfulgrass in Zn-contaminated soil. This is consistent with R. intraradices being more tolerant to Zn than F. mosseae, indicated by a higher colonization percentage in bashfulgrass roots. Taken together, our data indicate that AMFs possibly improve acquisition and translocation of P to promote increased biomass. Moreover, mycorrhiza did not enhance Zn accumulation in shoots and roots of bashfulgrass at the same Zn level. In the future, developing AMF (especially R. intraradices) inoculation of plants might be a desirable means of safe production of ornamental plants in metal-polluted soil.


Asunto(s)
Mimosa , Micorrizas , Contaminantes del Suelo , Hongos , Humanos , Fósforo , Raíces de Plantas , Suelo , Contaminantes del Suelo/toxicidad , Zinc/toxicidad
9.
Med Sci Monit ; 26: e921510, 2020 Apr 02.
Artículo en Inglés | MEDLINE | ID: mdl-32238796

RESUMEN

BACKGROUND SOX7 exerts a repressing effect against tumors and imposes vital influences on malignancies. Our research discussed the importance of SOX7 in breast cancer prognoses. MATERIAL AND METHODS SOX7 mRNA expression in breast cancer tissues samples and matched adjacent normal controls of breast cancer patients was measured by quantitative real-time-polymerase chain reaction (qRT-PCR). The relationship of SOX7 with clinicopathological characteristics were analyzed via chi-square test. The association of SOX7 levels with clinical outcomes was evaluated adopting the Kaplan-Meier method and multivariate Cox proportional hazards regression model. RESULTS SOX7 mRNA degree of expression exhibited a declining tendency in breast cancer tissue compared to paired bordering normal tissue specimens (P<0.001). In addition, the reduced SOX7 degree of expression had a strong correlation to larger cancer mass dimension (P=0.006) and lymph node metastasis (P=0.001). Survival analysis revealed that the overall survival (OS) time was much shorter among cases harboring low SOX7 degree of expression compared to high degree of expression (P=0.005). Moreover, SOX7 expression alone could predict OS among breast cancer patients (hazard ratio=3.956, 95% confidence interval=1.330-11.772, P=0.013). CONCLUSIONS SOX7 expression was downregulated in breast cancer tissues, and it could function as a useful prognostic marker in breast cancer.


Asunto(s)
Neoplasias de la Mama/genética , Neoplasias de la Mama/metabolismo , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos , Factores de Transcripción SOXF/metabolismo , Biomarcadores de Tumor/genética , Neoplasias de la Mama/mortalidad , Neoplasias de la Mama/patología , Regulación hacia Abajo , Femenino , Perfilación de la Expresión Génica , Humanos , Metástasis Linfática , Pronóstico , Modelos de Riesgos Proporcionales , Factores de Transcripción SOXF/genética , Análisis de Supervivencia
11.
Mikrochim Acta ; 186(8): 576, 2019 07 25.
Artículo en Inglés | MEDLINE | ID: mdl-31346739

RESUMEN

A composite probe has been developed for fluorometric determination and imaging of phosphate in real water samples and in cells. The method is based on the use of weakly blue fluorescent bromine-doped carbon dots (C-dots) containing aromatic carbon-bromine groups and loaded with Fe3+ ions. The carboxy, phenolic hydroxy and aldehyde groups on the surface of the C-dots can coordinate with Fe3+ to form an adsorbed complex that reduces the blue fluorescence through an inner filter effect. If phosphate is added, it will capture Fe3+ on the surface of C-dots and restore fluorescence by ~88% via a displacement approach. The probe, best operated at excitation/emission maxima of 370/418 nm, has a linear response in the 0.4 to 22 µM phosphate concentration range and a 0.25 µM of detection limit. The relative standard deviation (at a phosphate level of 8.0 µM) is 3.6% (for n = 5). The method was applied to confocal imaging of phosphate in HeLa cells. Graphical abstractSchematic representation of the synthesis of bromine-doped carbon dots (C-dots) by a "one-step" approach. They are shown to be capable of (a) detecting phosphate in real water samples through the displacement approach, and (b) of imaging intracellular phosphate.


Asunto(s)
Compuestos Férricos/química , Colorantes Fluorescentes/química , Fosfatos/análisis , Puntos Cuánticos/química , Espectrometría de Fluorescencia , Bromo/química , Carbono/química , Agua Dulce/análisis , Células HeLa , Humanos , Iones/química , Límite de Detección , Microscopía Confocal
12.
Proc Natl Acad Sci U S A ; 111(8): 2903-8, 2014 Feb 25.
Artículo en Inglés | MEDLINE | ID: mdl-24516152

RESUMEN

An annually resolved and absolutely dated ring-width chronology spanning 4,500 y has been constructed using subfossil, archaeological, and living-tree juniper samples from the northeastern Tibetan Plateau. The chronology represents changing mean annual precipitation and is most reliable after 1500 B.C. Reconstructed precipitation for this period displays a trend toward more moist conditions: the last 10-, 25-, and 50-y periods all appear to be the wettest in at least three and a half millennia. Notable historical dry periods occurred in the 4th century BCE and in the second half of the 15th century CE. The driest individual year reconstructed (since 1500 B.C.) is 1048 B.C., whereas the wettest is 2010. Precipitation variability in this region appears not to be associated with inferred changes in Asian monsoon intensity during recent millennia. The chronology displays a statistical association with the multidecadal and longer-term variability of reconstructed mean Northern Hemisphere temperatures over the last two millennia. This suggests that any further large-scale warming might be associated with even greater moisture supply in this region.


Asunto(s)
Cambio Climático/historia , Lluvia , Nieve , Árboles/crecimiento & desarrollo , Geografía , Historia Antigua , Tibet , Factores de Tiempo , Árboles/anatomía & histología
13.
Cell Physiol Biochem ; 34(5): 1723-32, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25428728

RESUMEN

AIMS: Neutrophils can synthesize leukotriene B4 (LTB4) by activating the 5-lipoxygenase (5-LO)signaling pathway. LTB4 is a pro-inflammatory mediator associated with the etiology and progression of atherosclerosis. It can increase function and number of neutrophils in an autocrine manner. Since hypercholesterolemia is associated with an increase in the number and function of neutrophils, we hypothesized that this effect could be mediated through increased production of LTB4 in neutrophils. METHODS/RESULTS: Hypercholesterolemia was modeled in Wistar rats by feeding them with a high cholesterol diet. The induction of hypercholesterolemia caused an increase in the plasma levels of LTB4, following lipopolysaccharide stimulation. This effect was recapitulated in vitro, both in the presence and absence of stimulation with the activator of 5-LO, A23187. Neutrophils in hypercholesterolemia rats expressed similar total levels of 5-LO as control rats, but displayed increased nuclear localization of 5-LO, as well as elevated levels of phosphorylated 5-LO and ERK1/2. In vitro, MßCD/cholesterol complexes enriched cholesterol in neutrophils, resulted in similar changes in 5-LO/LTB4. In addition, these alterations could be inhibited with the ERK inhibitor PD98059. CONCLUSION: Hypercholesterolemia increases LTB4 production in neutrophils by increasing the nuclear localization of 5-LO, which is the result of its phosphorylation by activated ERK1/2.


Asunto(s)
Araquidonato 5-Lipooxigenasa/metabolismo , Núcleo Celular/metabolismo , Hipercolesterolemia/metabolismo , Leucotrieno B4/metabolismo , Neutrófilos/metabolismo , Animales , Calcimicina/farmacología , Colesterol/metabolismo , Femenino , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Neutrófilos/efectos de los fármacos , Ratas , Ratas Wistar , Transducción de Señal/efectos de los fármacos
14.
Antonie Van Leeuwenhoek ; 105(5): 971-8, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24677143

RESUMEN

A red-pink, Gram-negative, rod-shaped, non-motile, non-spore-forming bacterium, designated strain DK6-37 was isolated from the permafrost region of Qilian Mountains in northwest of China. Phylogenetic analysis based on 16S rRNA gene sequencing indicated that this isolate represents a novel member of the genus Hymenobacter, with low sequence similarities (<97 %) to recognized Hymenobacter species. Optimum growth was observed at 28 °C, pH 7.0 and 0 % NaCl. The strain was found to contain MK-7 as the predominant menaquinone. The polar lipids were identified as phosphatidylethanolanmine, two unknown aminophospholipids, one unknown aminolipid and three unknown polar lipids. The major fatty acids were identified as summed feature 3 (C16:1 ω7c/C16:1 ω6c as defined by MIDI), summed feature 4 (anteiso-C17:1 B/iso-C17:1 I), C16:1 ω5c, iso-C17:0 3-OH, iso-C15:0 and C18:0. The DNA G + C content was determined to be 67.4 mol %. On the basis of the polyphasic evidence presented, it is proposed that strain DK6-37 represents a novel species of the genus Hymenobacter, for which the name Hymenobacter qilianensis sp. nov. is proposed. The type strain is DK6-37(T) (= CGMCC 1.12720(T) = JCM 19763(T)).


Asunto(s)
Cytophagaceae/clasificación , Cytophagaceae/aislamiento & purificación , Microbiología del Suelo , Técnicas de Tipificación Bacteriana , Composición de Base , China , Análisis por Conglomerados , Cytophagaceae/genética , Cytophagaceae/fisiología , ADN Bacteriano/química , ADN Bacteriano/genética , ADN Ribosómico/química , ADN Ribosómico/genética , Ácidos Grasos/análisis , Datos de Secuencia Molecular , Fosfolípidos/análisis , Filogenia , Quinonas/análisis , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN
15.
Environ Monit Assess ; 186(9): 5883-95, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-24865385

RESUMEN

Aquatic organisms' tolerance to water pollution is widely used to monitor and assess freshwater ecosystem health. Tolerance values (TVs) estimated based on statistical analyses of species-environment relationships are more objective than those assigned by expert opinion. Region-specific TVs are the basis for developing accurate bioassessment metrics particularly in developing countries, where both aquatic biota and their responses to human disturbances have been poorly documented. We used principal component analysis to derive a synthetic gradient for four stressor variables (total nitrogen, total phosphorus, dissolved oxygen, and % silt) based on 286 sampling sites in the Taihu Lake and Qiantang River basins (Yangtze River Delta), China. We used the scores of taxa on the first principal component (PC1), which explained 49.8% of the variance, to estimate the tolerance values (TV(r)) of 163 macroinvertebrates taxa that were collected from at least 20 sites, 81 of which were not included in the Hilsenhoff TV lists (TV(h)) of 1987. All estimates were scaled into the range of 1-10 as in TV(h). Of all the taxa with different TVs, 46.3% of TV(r) were lower and 52.4% were higher than TV(h). TV(r) were significantly (p < 0.01, Fig. 2), but weakly (r(2) = 0.34), correlated with TVh. Seven biotic metrics based on TVr were more strongly correlated with the main stressors and were more effective at discriminating references sites from impacted sites than those based on TV(h). Our results highlight the importance of developing region-specific TVs for macroinvertebrate-based bioassessment and to facilitate assessment of streams in China, particularly in the Yangtze River Delta.


Asunto(s)
Monitoreo del Ambiente/métodos , Invertebrados/fisiología , Contaminantes del Agua/toxicidad , Adaptación Fisiológica , Animales , Organismos Acuáticos/fisiología , Biota , China , Ecosistema , Invertebrados/clasificación , Ríos/química , Contaminantes del Agua/análisis , Contaminación del Agua/análisis , Contaminación del Agua/estadística & datos numéricos
16.
Zhongguo Gu Shang ; 37(6): 6295-34, 2024 Jun 25.
Artículo en Zh | MEDLINE | ID: mdl-38910389

RESUMEN

As one of the common traumatic diseases in clinical practice, peripheral nerve injury (PIN) often causes nerve pain, abnormal reflexes, autonomic disorders, and even sensorimotor disorders due to the slow regeneration rate after injury, which seriously affects body function. Even as the gold standard of treatment, autologous nerve transplantation has limitations such as limited donor area and donor injury, which greatly limits its clinical application effect. Therefore, the preparation of artificial nerve grafts suitable for clinical practice has become the future development trend of peripheral nerve injury treatment, and the repair of injury defects and the promotion of nerve regeneration have also become research hotspots in tissue engineering and regenerative medicine. In recent years, extensive research has been carried out on nerve guidance conduits (NGCs) in the field of nerve regeneration and repair, in which scaffold materials and internal fillers have also become the focus of research as the core elements of neural catheters, and a series of achievements have been made in the application of new materials, embedding stem cells/precursor cells, and developing trophic factors and drug-loaded sustained-release systems. Therefore, this paper focuses on the application progress of hydrogel and its related derivative materials in the field of peripheral nerve injury repair, and provides new ideas for promoting the related research of tissue engineering and clinical medicine.


Asunto(s)
Hidrogeles , Regeneración Nerviosa , Traumatismos de los Nervios Periféricos , Traumatismos de los Nervios Periféricos/terapia , Traumatismos de los Nervios Periféricos/cirugía , Humanos , Regeneración Nerviosa/efectos de los fármacos , Animales , Ingeniería de Tejidos/métodos
17.
BMC Genom Data ; 25(1): 57, 2024 Jun 10.
Artículo en Inglés | MEDLINE | ID: mdl-38858616

RESUMEN

The Quercus L. species is widely recognized as a significant group in the broad-leaved evergreen forests of tropical and subtropical East Asia. These plants hold immense economic value for their use as firewood, furniture, and street trees. However, the identification of Quercus species is considered challenging, and the relationships between these species remain unclear. In this study, we sequenced and assembled the chloroplast (cp.) genomes of four Quercus section Cyclobalanopsis species (Quercus disciformis, Quercus dinghuensis, Quercus blackei, and Quercus hui). Additionally, we retrieved six published cp. genome sequences of Cyclobalanopsis species (Quercus fleuryi, Quercus pachyloma, Quercus ningangensis, Quercus litseoides, Quercus gilva, and Quercus myrsinifolia). Our aim was to perform comparative genomics and phylogenetic analyses of the cp. whole genome sequences of ten Quercus section Cyclobalanopsis species. The results revealed that: (1) Quercus species exhibit a typical tetrad structure, with the cp. genome lengths of the newly sequenced species (Q. disciformis, Q. dinghuensis, Q. blakei, and Q. hui) being 160,805 bp, 160,801 bp, 160,787 bp, and 160,806 bp, respectively; (2) 469 SSRs were detected, among which A/T base repeats were the most common; (3) no rearrangements or inversions were detected within the chloroplast genomes. Genes with high nucleotide polymorphism, such as rps14-psaB, ndhJ-ndhK, rbcL-accD, and rps19-rpl2_2, provided potential reference loci for molecular identification within the Cyclobalanopsis section; (4) phylogenetic analysis showed that the four sections of Cyclobalanopsis were grouped into sister taxa, with Q. hui being the first to diverge from the evolutionary branch and Q. disciformis being the most closely related to Q. blackei. The results of this study form the basis for future studies on taxonomy and phylogenetics.


Asunto(s)
Genoma del Cloroplasto , Filogenia , Quercus , Quercus/genética , Genoma del Cloroplasto/genética
18.
World J Gastroenterol ; 30(1): 91-107, 2024 Jan 07.
Artículo en Inglés | MEDLINE | ID: mdl-38293320

RESUMEN

BACKGROUND: The pathogenicity of Helicobacter pylori is dependent on factors including the environment and the host. Although selenium is closely related to pathogenicity as an environmental factor, the specific correlation between them remains unclear. AIM: To investigate how selenium acts on virulence factors and reduces their toxicity. METHODS: H. pylori strains were induced by sodium selenite. The expression of cytotoxin-associated protein A (CagA) and vacuolating cytotoxin gene A (VacA) was determined by quantitative PCR and Western blotting. Transcriptomics was used to analyze CagA, CagM, CagE, Cag1, Cag3, and CagT. C57BL/6A mice were infected with the attenuated strains subjected to sodium selenite induction, and H. pylori colonization, inflammatory reactions, and the cell adhesion ability of H. pylori were assessed. RESULTS: CagA and VacA expression was upregulated at first and then downregulated in the H. pylori strains after sodium selenite treatment. Their expression was significantly and steadily downregulated after the 5th cycle (10 d). Transcriptome analysis revealed that sodium selenite altered the levels affect H. pylori virulence factors such as CagA, CagM, CagE, Cag1, Cag3, and CagT. Of these factors, CagM and CagE expression was continuously downregulated and further downregulated after 2 h of induction with sodium selenite. Moreover, CagT expression was upregulated before the 3rd cycle (6 d) and significantly downregulated after the 5th cycle. Cag1 and Cag3 expression was upregulated and downregulated, respectively, but no significant change was observed by the 5th cycle. C57BL/6A mice were infected with the attenuated strains subjected to sodium selenite induction. The extent of H. pylori colonization in the stomach increased; however, sodium selenite also induced a mild inflammatory reaction in the gastric mucosa of H. pylori-infected mice, and the cell adhesion ability of H. pylori was significantly weakened. CONCLUSION: These results demonstrate that H. pylori displayed virulence attenuation after the 10th d of sodium selenite treatment. Sodium selenite is a low toxicity compound with strong stability that can reduce the cell adhesion ability of H. pylori, thus mitigating the inflammatory damage to the gastric mucosa.


Asunto(s)
Infecciones por Helicobacter , Helicobacter pylori , Selenio , Animales , Ratones , Antígenos Bacterianos/genética , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Factores de Virulencia/genética , Factores de Virulencia/metabolismo , Selenito de Sodio/farmacología , Ratones Endogámicos C57BL , Citotoxinas , Infecciones por Helicobacter/metabolismo
19.
Yao Xue Xue Bao ; 48(7): 1148-55, 2013 Jul.
Artículo en Zh | MEDLINE | ID: mdl-24133984

RESUMEN

The hydrophilicity of the normal decoction pieces (NDP) of Indigo Naturalis is not good, therefore, it is not suit for decoctions. In this paper, powder modification technology is used and some NDP and alcohol are ground together in the vibromill to prepare the hydrophilic decoction pieces (HDP) of Indigo Naturalis. Initially, the properties of NDP, ultrafine decoction pieces (UDP) and HDP are compared, the hydrophilicity of UDP was promoted slightly, that of HDP is promoted dramatically. Then, three batches of Indigo Naturalis are prepared to HDP separately, but there is no obvious difference in the contact angle. Furthermore, the size distribution, surface area and micro-shape of HDP are bigger than that of UDP and smaller than NDP. The contents of indigo and indirubin in three decoction pieces are the same, as well as the species of inorganic substance, although there is a little difference in the proportion of five inorganic substances. The fact suggests the change of physical state and the qualitative and quantitative change of organism and inorganic substances are not the main factors to influence the hydrophilicity. In addition, hydroxyl, methylene and methyl can be identified at the wavenumber of 3 356 cm(-1) and 1 461 cm(-1) in infrared spectrum; the content of alcohol in HDP is 0.67% measured by gas chromatogram. The stability of HDP in the heating condition is studied, the fact suggests the hydrophilic effect of HDP at 40 degrees C is relatively stable. All above research suggests that the alcohol is the main factor to influence the hydrophilicity and maybe the intermolecular force which fixed alcohol molecule on the surface of Indigo Naturalis is the basic principle to produce the hydrophilicity.


Asunto(s)
Interacciones Hidrofóbicas e Hidrofílicas , Carmin de Índigo/química , Tecnología Farmacéutica/métodos , Acanthaceae/química , Alcoholes/análisis , Carmin de Índigo/análisis , Carmin de Índigo/aislamiento & purificación , Indoles/análisis , Isatis/química , Microscopía Electrónica de Rastreo , Tamaño de la Partícula , Plantas Medicinales/química , Polygonum/química , Polvos , Propiedades de Superficie , Difracción de Rayos X
20.
Zhonghua Fu Chan Ke Za Zhi ; 48(6): 432-6, 2013 Jun.
Artículo en Zh | MEDLINE | ID: mdl-24103122

RESUMEN

OBJECTIVE: To evaluate clinical value of denaturing high performance liquid chromatography (DHPLC) used in detecting transforming growth factor beta receptor 3 (TGFBR-3) exons 11 and 12 polymorphism in women with idiopathic premature ovarian failure (POF). METHODS: From Feb. 2009 to Dec. 2011, 110 patients with idiopathic POF undergoing treatment at Shenzhen Maternal & Child Health Institute affiliated to Southern Medical University were enrolled as POF group in this study. In the mean time, 110 women under 40 years old with normal hormonal level and menstrual cycles as control group. The exons 11 and 12 of TGFBR-3 gene polymorphism were screened by using DHPLC, and results of DNA sequencing was as golden standard. Some related indexes were calculated, such as sensitivity, specificity, false negative value, false positive value, Youden index, positive predictive value, and negative predictive value. At the same time, 20% of the tested specimens were chosen randomly and detected by DHPLC again. The value of Kappa index were calculated by comparing the results between the first and second DHPLC analysis. RESULTS: The exon 11 of TGFBR-3 were not identified gene polymorphism and two nucleotide polymorphisms were identified in exon 12. For 2022 T/C polymorphism, the frequencies of CC with 0.9% (1/110), TC with 22.7% (25/110), TT with 76.4% (84/110), C with 12.3% (27/220) and T with 87.7% (193/220) in POF group were significantly different from CC with 0, TC with 9.1% (10/110) and TT with 90.9% (100/110), C with 4.5% (10/220) and T with 95.5% (210/220) in control group (all P<0.05). Allelic and genotypic frequencies of 2161-75 C/T were not differed significantly between the two groups (all P>0.05). As DNA sequencing as golden standard, DHPLC showed that the sensitivity was 100%, specificity was 97.9%, Youden index was 97.9%, positive predictive value was 96.3%, negative predictive value was 100%, and Kappa index was 0.888 (P<0.05). CONCLUSION: DHPLC analysis is higher validity, reliability and practicability method in detecting TGFBR-3 polymorphism in idiopathic premature ovarian failure.


Asunto(s)
Polimorfismo de Nucleótido Simple , Insuficiencia Ovárica Primaria/genética , Proteoglicanos/genética , Receptores de Factores de Crecimiento Transformadores beta/genética , Adulto , Pueblo Asiatico/genética , Estudios de Casos y Controles , Cromatografía Líquida de Alta Presión , Exones/genética , Femenino , Frecuencia de los Genes , Estudios de Asociación Genética , Genotipo , Humanos , Reacción en Cadena de la Polimerasa , Sensibilidad y Especificidad , Análisis de Secuencia de ADN
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA