RESUMEN

Here, the high fluorescent silicon-doped carbon quantum dots (Si-CQDs) were prepared by a facile and one-pot hydrothermal assay using 3-aminopropyltrimethoxysilane as the carbon and silicon source. The prepared Si-CQDs exhibit favorable water-soluble, high-temperature resistance, acid resistance, alkali resistance, high ionic strength resistance, high photostability, film-forming ability and solid-state fluorescence. Compared to other Si-CQDs that have been reported, the prepared Si-CQDs show unique up-conversion fluorescence. Furthermore, it is found that berberine hydrochloride (BH) can effectively quench the down- and up-conversion fluorescence of the Si-CQDs, making it can be used as a highly sensitive and specific probe for BH dual-mode sensing. Meanwhile, the linear range of down-conversion fluorescence detection for BH is 0.5-30.0 µmol/L with a limit of detection (LOD) of 50 nmol/L, and the linear range of up-conversion fluorescence assay for BH is 0-25.0 µmol/L. The mechanism of down-conversion fluorescence quenching by BH was investigated through a series of studies. The results show the quenching mechanism is the inner filter effect (IFE). Moreover, this proposed strategy has been well used to analyze BH in urine samples with satisfactory results.

Asunto(s)

Berberina , Puntos Cuánticos , Carbono , Colorantes Fluorescentes , Nitrógeno , Silicio

RESUMEN

The complete chloroplast genome sequence of rare and endangered Camellia pubipetala Y. Wan & S. Z. Huang (Theaceae) was mentioned in this research. By studying comparatively, we found that the C. pubipetala Y. Wan & S. Z. Huang chloroplast genome was 156,993 bp in length and composed of 86,590 bp LSC, 18,211 bp SSC, and two reverse repeating regions with 26,090 bp. The whole GC content was 37.33%. The genome encoded 116 functional genes, including 80 protein-coding genes, 32 tRNA genes, and 4 rRNA genes. In order to find the phylogenetic relationship of C. pubipetala Y. Wan & S. Z. Huang within Camellia genus, we reconstructed phylogenetic tree. The results indicate that C. pubipetala Y. Wan & S. Z. Huang was closely related to Camellia huana voucher and Camellia ptilosperma.

RESUMEN

BACKGROUND: Plastic bronchitis (PB) is a rare, variable, and potentially fatal disease. This study aimed to assess the efficacy of fiberoptic bronchoscopy (FOB) and bronchoalveolar lavage (BAL) in treating children with PB. METHODS: In total, 15 children with PB, between 2012 and 2020, were enrolled in our study. Within 12 hours of admission, FOB and BAL were performed and reviewed under local anesthesia and sedation. Before and after FOB, clinical findings and chest imaging were evaluated. RESULTS: Regarding the onset of symptoms before FOB, all cases had prominent cough for 7.00 ± 4.55 days, and 14 had persistent high fever. In total, 13 cases had complete obstruction from bronchial casts, consistent with consolidated lesions; 2 had partial airway obstruction. Within 3 days, complete resolution was revealed in nine cases. Overall, six cases underwent repeated FOB (range, 2-3 times) for persistent atelectasis and airway obstruction. Except for two cases with type 2 PB, cast histology confirmed type 1 PB for all cases. Only eight children had minor intra- and post-procedure complications. Reverse transcription-polymerase chain reaction for Mycoplasma pneumoniae in sputum and BAL samples were positive in 13 cases. Next-generation sequencing of the BAL samples was positive for adenovirus and Human parainfluenza virus in one case, respectively. During 1 month to 7 years of follow-up, no patient developed PB recurrence, asthmatic attacks, or chronic cough. CONCLUSIONS: Early FOB and BAL were effective in alleviating clinical findings, atelectasis, and airway obstruction. Serial FOB could be performed in patients with recurrent symptoms.

Asunto(s)

Bronquitis/terapia , Lavado Broncoalveolar , Broncoscopía/métodos , Neumonía por Mycoplasma/terapia , Niño , Preescolar , Femenino , Tecnología de Fibra Óptica , Humanos , Lactante , Masculino , Mycoplasma pneumoniae

RESUMEN

Our previous study showed that feeding mice with vitamin D deficiency diet markedly alleviated high-fat-diet-induced overweight, hyperinsulinemia, and hepatic lipid accumulation. Moreover, vitamin D deficiency up-regulated the expression of uncoupling protein 3 (Ucp3) in white adipose tissue (WAT) and brown adipose tissue (BAT). The present study aimed to further investigate the effects of vitamin D and vitamin D receptor (Vdr) on Ucp1-3 (Ucps) expression in brown adipocyte and the mechanism involved in it. Rat primary brown adipocytes were separated and purified. The effects of the 1,25(OH)2D3 (1,25-dihydroxyvitamin D3; the hormonal form of vitamin D) and Vdr system on Ucps expression in brown adipocytes were investigated in basal condition and activated condition by isoproterenol (ISO) and triiodothyronine (T3). Ucps expression levels were significantly down-regulated by 1,25(OH)2D3 in the activated brown adipocyte. Vdr silencing reversed the down-regulation of Ucps by 1,25(OH)2D3, whereas Vdr overexpression strengthened the down-regulation effects. Hairless protein did express in brown adipocyte and was localized in cell nuclei. 1,25(OH)2D3 increased Hairless protein expression in the cell nuclei. Hairless (Hr) silencing notably elevated Ucps expression in activated condition induced by ISO and T3. Moreover, immunoprecipitation results revealed that Vdr could interact with Hairless, which might contribute to decreasing expression of Vdr target gene Ucps. These data suggest that vitamin D suppresses expression of Ucps in brown adipocyte in a Vdr-dependent manner and the corepressor Hairless protein probably plays a role in the down-regulation.

Asunto(s)

Adipocitos Marrones/efectos de los fármacos , Calcitriol/farmacología , Proteínas Desacopladoras Mitocondriales/metabolismo , Receptores de Calcitriol/agonistas , Factores de Transcripción/metabolismo , Vitaminas/farmacología , Adipocitos Marrones/metabolismo , Animales , Células Cultivadas , Regulación de la Expresión Génica , Masculino , Proteínas Desacopladoras Mitocondriales/genética , Ratas Sprague-Dawley , Ratas Wistar , Receptores de Calcitriol/genética , Receptores de Calcitriol/metabolismo , Transducción de Señal , Factores de Transcripción/genética , Proteína Desacopladora 1/genética , Proteína Desacopladora 1/metabolismo , Proteína Desacopladora 2/genética , Proteína Desacopladora 2/metabolismo , Proteína Desacopladora 3/genética , Proteína Desacopladora 3/metabolismo

RESUMEN

In this study, two chlorophyll A/B binding protein (CAB) genes (CsCP1 and CsCP2) in tea plant were cloned. The proteins encoded by these genes belong to the external or internal antenna proteins of PS II, respectively. They may be the targets of physiological regulation for tea leaf cell PS II because they all contain multiple functional domains and modifiable sites. The CAB gene family in the tea genome consists of 25 homologous genes. We measured the expression patterns of ten genes in the CsCP1 and CsCP2 subfamily under six different stresses. CsCP1 expression was inhibited in response to 6 kinds of stress; CsCP2 expression was slightly upregulated only after cold stress and ABA treatment. However, the expression levels of CSA016997 and CSA030476 were upregulated significantly in the six stresses. The results suggested that the 10 CAB genes may have different functions in tea leaves. Moreover, changes in the expression of the 10 genes under stress appear to be related to ABA- and MeJA-dependent signalling pathways, and their responses to MeJA treatment is faster than those to ABA. In addition, we introduced our experiences for cloning the genes in the context of complex genomes.

Asunto(s)

Camellia sinensis/genética , Proteínas de Unión a Clorofila/genética , Regulación de la Expresión Génica de las Plantas , Genes de Plantas , Familia de Multigenes , Camellia sinensis/metabolismo , Proteínas de Unión a Clorofila/química , Proteínas de Unión a Clorofila/metabolismo , Clonación Molecular , Perfilación de la Expresión Génica , Modelos Moleculares , Fotosíntesis/genética , Filogenia , Conformación Proteica , Relación Estructura-Actividad , Transcriptoma

RESUMEN

Aphid-parasitoid interactions have been widely used as a model system in research studies on the structure and functions of arthropod food web. Research on aphid-parasitoid food webs is hindered by their micromorphological characteristics and the high amount of labor associated with their development. Species-specific primers for cotton aphids and their parasitoids were designed and integrated into two multiplex PCRs and six singleplex PCRs, and all PCRs were optimized to achieve high specificity and sensitivity (100-10,000 DNA copies). One cotton aphid (Aphis gossypii) as well as three primary parasitoid and seven hyperparasitoid species or genera were detected using this molecular approach. This group comprises all the primary parasitoids and 97.2-99.6% of the hyperparasitoids reported in cotton fields in northern China. A tritrophic aphid-primary parasitoid-hyperparasitoid food web was then established. The described method constitutes an efficient tool for quantitatively describing the aphid-primary parasitoid-hyperparasitoid food webs and assessing the efficiency of the biological control of parasitoids in cotton fields in northern China.

Asunto(s)

Áfidos , Cadena Alimentaria , Gossypium/parasitología , Interacciones Huésped-Parásitos/genética , Animales , Áfidos/genética , Áfidos/metabolismo , Áfidos/parasitología , China , Reacción en Cadena de la Polimerasa Multiplex

RESUMEN

Monte Carlo simulations were performed for various vancomycin dosage regimens to evaluate the potential for development of vancomycin resistance in meticillin-resistant Staphylococcus aureus (MRSA). When the target of free AUC(24)/MIC≥200 was considered (where AUC(24) is the area under the drug concentration-time curve in a 24-h interval and MIC is the minimum inhibitory concentration), a standard dose regimen (1000 mg every 12 h) yielded unacceptable simulated outcomes in patients with normal renal function; in particular, the probability of target attainment (PTA) was only 30.5% at an MIC of 1mg/L. For the same dosage regimens and the mutant prevention concentration (MPC)-based pharmacokinetic target (total AUC(24)/MPC>15), the cumulative fraction of response exceeded 80% for all renal function strata; low values of PTA (<80%) were obtained only for isolates with MPCs of ≥22.4 mg/L, which consisted of all 21 strains of heterogeneous vancomycin-intermediate S. aureus (hVISA) and a handful of non-hVISA strains with MICs of 2mg/L (32%; 16/50). Based on the current status of vancomycin resistance, we conclude that total AUC(24)/MPC>15, derived from in vivo experiments, is more suitable to predict the development of vancomycin resistance. In clinical practice, individualised vancomycin therapy should be considered to minimise selection of resistance mutations.

Asunto(s)

Antibacterianos/farmacología , Antibacterianos/farmacocinética , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Resistencia a la Vancomicina/efectos de los fármacos , Vancomicina/farmacología , Vancomicina/farmacocinética , Animales , Antibacterianos/administración & dosificación , Área Bajo la Curva , Humanos , Staphylococcus aureus Resistente a Meticilina/aislamiento & purificación , Pruebas de Sensibilidad Microbiana , Método de Montecarlo , Mutación , Conejos , Infecciones Estafilocócicas/microbiología , Vancomicina/administración & dosificación

RESUMEN

The overall survival rate and prognosis of patients with laryngeal cancer are not optimistic despite advances in therapeutic techniques. Gene expression prognostic models enable the development of more appropriate treatment strategies. The human gene PTPN11 encoding a non-receptor protein tyrosine phosphatase, Src homology phosphotyrosine phosphatase 2 (SHP2), is a well-documented proto-oncogene in various malignancies. This study investigated the role of SHP2 expression and associated clinical manifestations in laryngeal cancer using a tissue microarray of 112 pairs of laryngeal cancer samples and corresponding adjacent normal mucosae. SHP2 expression increased in laryngeal cancer, and this result was associated with the poor survival rate of laryngeal cancer patients. Moreover, increased SHP2 expression remarkably promoted the growth of laryngeal cancer cells in vitro and tumorigenicity of laryngeal cancer cells in vivo. The Ras/Raf/Mek/Erk pathway was also found to be involved in the SHP2-induced growth of laryngeal cancer cells. Overall, our findings indicated that SHP2 plays an important role in laryngeal cancer tumorigenesis and that its expression is negatively correlated with the prognosis of patients. Thus, SHP2 may be a promising combinational therapeutic target for treatment of laryngeal cancer. The interference of SHP2 expression can serve as a novel strategy for laryngeal cancer treatment.

Asunto(s)

Neoplasias Laríngeas/patología , MAP Quinasa Quinasa 1/metabolismo , Proteína Quinasa 1 Activada por Mitógenos/metabolismo , Proteína Quinasa 3 Activada por Mitógenos/metabolismo , Proteína Tirosina Fosfatasa no Receptora Tipo 11/metabolismo , Quinasas raf/metabolismo , Proteínas ras/metabolismo , Adulto , Anciano , Anciano de 80 o más Años , Animales , Apoptosis , Western Blotting , Proliferación Celular , Femenino , Humanos , Técnicas para Inmunoenzimas , Neoplasias Laríngeas/metabolismo , Neoplasias Laríngeas/mortalidad , MAP Quinasa Quinasa 1/genética , Masculino , Ratones , Ratones Desnudos , Persona de Mediana Edad , Proteína Quinasa 1 Activada por Mitógenos/genética , Proteína Quinasa 3 Activada por Mitógenos/genética , Estadificación de Neoplasias , Pronóstico , Proteína Tirosina Fosfatasa no Receptora Tipo 11/genética , Proto-Oncogenes Mas , ARN Mensajero/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Transducción de Señal , Tasa de Supervivencia , Células Tumorales Cultivadas , Ensayos Antitumor por Modelo de Xenoinjerto , Quinasas raf/genética , Proteínas ras/genética

RESUMEN

No mutant-prevention concentration (MPC) with methicillin-resistant Staphylococcus epidermidis (MRSE) has been reported. The study aimed to evaluate the propensity of vancomycin individually and in combination to prevent MRSE from mutation. A total of 10 MRSE clinical isolates were included in the study. Susceptibility testing demonstrated that the susceptibility rates to vancomycin, rifampicin, levofloxacin and fosfomycin were 100, 100, 50 and 90%, respectively. The fractional inhibition concentration indices (FICI) for vancomycin combined with rifampicin, levofloxacin or fosfomycin were ≥1.5 but ≤2, ≥1.5 but ≤2, and >0.5 but ≤1.5, respectively, implying indifferent interactivity. The MPC with susceptible strains was determined to be the lowest antibiotic concentration inhibiting visible growth among 10(10) CFU on four agar plates (9 cm in diameter) after a 72-h incubation at 37°C. The MPCs were 16~32, >64, ≥64 and 4~16 µg ml(-1) for vancomycin, rifampicin, fosfomycin and levofloxacin, respectively. The vancomycin MPCs of combinations with fosfomycin (32 µg ml(-1)), levofloxacin (2 µg ml(-1)) and rifampicin (2 or 4 µg ml(-1)) were 1~4, 16~32 and 16~32 µg ml(-1), respectively. Against mutants selected by vancomycin, rifampicin, levofloxacin and fosfomycin individually, antibiotics had standard MICs of 2~4 µg ml(-1) for vancomycin, >64 µg ml(-1) for rifampicin, 4~8 µg ml(-1) for levofloxacin and 64 µg ml(-1) for fosfomycin. Thus single-step mutation can lead to resistance of MRSE to rifampicin, levofloxacin and fosfomycin, rather than non-susceptibility to vancomycin. Vancomycin-fosfomycin combination might be a superior alternative to vancomycin in blocking the growth of MRSE mutants, especially for high-organism-burden infections.

Asunto(s)

Antibacterianos/administración & dosificación , Fosfomicina/administración & dosificación , Levofloxacino/administración & dosificación , Rifampin/administración & dosificación , Infecciones Estafilocócicas/tratamiento farmacológico , Staphylococcus epidermidis/efectos de los fármacos , Vancomicina/administración & dosificación , Sinergismo Farmacológico , Quimioterapia Combinada , Genes Bacterianos/efectos de los fármacos , Humanos , Resistencia a la Meticilina/genética , Pruebas de Sensibilidad Microbiana , Mutación/efectos de los fármacos , Infecciones Estafilocócicas/microbiología , Staphylococcus epidermidis/genética , Staphylococcus epidermidis/aislamiento & purificación

RESUMEN

The flavonoids metabolic pathway plays central roles in floral coloration, in which anthocyanins and flavonols are derived from common precursors, dihydroflavonols. Flavonol synthase (FLS) catalyses dihydroflavonols into flavonols, which presents a key branch of anthocyanins biosynthesis. The yellow flower of Camellia nitidissima Chi. is a unique feature within the genus Camellia, which makes it a precious resource for breeding yellow camellia varieties. In this work, we characterized the secondary metabolites of pigments during floral development of C. nitidissima and revealed that accumulation of flavonols correlates with floral coloration. We first isolated CnFLS1 and showed that it is a FLS of C. nitidissima by gene family analysis. Second, expression analysis during floral development and different floral organs indicated that the expression level of CnFLS1 was regulated by developmental cues, which was in agreement with the accumulating pattern of flavonols. Furthermore, over-expression of CnFLS1 in Nicotiana tabacum altered floral colour into white or light yellow, and metabolic analysis showed significant increasing of flavonols and reducing of anthocyanins in transgenic plants. Our work suggested CnFLS1 plays critical roles in yellow colour pigmentation and is potentially a key point of genetic engineering toward colour modification in Camellia.

Asunto(s)

Camellia/crecimiento & desarrollo , Flavonoides/metabolismo , Flores/crecimiento & desarrollo , Oxidorreductasas/química , Pigmentación/genética , Proteínas de Plantas/química , Antocianinas/biosíntesis , Antocianinas/genética , Camellia/genética , Flavonoides/genética , Flores/metabolismo , Regulación de la Expresión Génica de las Plantas , Oxidorreductasas/genética , Proteínas de Plantas/genética , Plantas Modificadas Genéticamente , Nicotiana/genética , Nicotiana/metabolismo

RESUMEN

BACKGROUND: It was previously reported that propofol, an intravenously administered hypnotic and anesthetic agent, protects organs from ischemia-reperfusion (I/R) injury. However, the underlying mechanisms are largely unknown. Glycogen synthase kinase 3ß (GSK-3ß) is known to play an important role in the oxidative stress-induced apoptosis. In this study, we investigated the role of GSK-3ß and mitochondrial permeability transition pore (MPTP) in the protective effects of propofol against hepatic I/R injury. MATERIALS AND METHODS: The left and median hepatic artery and the portal vein branches were blocked by no-damage artery clips to create the model of partial ischemia (70%), and liver lobes were subjected to warm ischemia for 30, 60, 90 min, respectively. Reperfusion of 120 min was then initiated by the removal of clamp. The MPTP opening was assessed by measuring mitochondrial large amplitude swelling and mitochondrial membrane potential. RESULTS: Pretreatment with propofol in conditions of hepatic I/R inhibits the apoptosis of hepatocytes as evidenced by decreased terminal deoxynucleotidyl transferase dUTP nick end labeling-positive cells. Importantly, propofol suppressed the mitochondrial GSK-3ß by promoting or preserving its phosphorylation at Ser9, thus restraining the opening of MPTP and preventing the mitochondrial swell and mitochondrial membrane potential collapse. CONCLUSIONS: Propofol protects liver from I/R injury by sustaining the mitochondrial function, which is possibly involved with the modulation of MPTP and GSK-3ß.

Asunto(s)

Anestésicos Intravenosos/farmacología , Glucógeno Sintasa Quinasa 3/metabolismo , Hígado/efectos de los fármacos , Propofol/farmacología , Daño por Reperfusión/metabolismo , Daño por Reperfusión/prevención & control , Animales , Apoptosis/efectos de los fármacos , Glucógeno Sintasa Quinasa 3 beta , Hígado/enzimología , Hígado/patología , Masculino , Mitocondrias/efectos de los fármacos , Mitocondrias/enzimología , Membranas Mitocondriales/efectos de los fármacos , Membranas Mitocondriales/enzimología , Estrés Oxidativo/efectos de los fármacos , Fosforilación/efectos de los fármacos , Distribución Aleatoria , Ratas , Ratas Sprague-Dawley , Daño por Reperfusión/patología

Asunto(s)

Proteínas Bacterianas/genética , Farmacorresistencia Bacteriana/genética , Metiltransferasas/genética , Serratia marcescens/efectos de los fármacos , Serratia marcescens/genética , Anciano , China , Humanos , Masculino , Datos de Secuencia Molecular , Quinolonas/uso terapéutico , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Serratia marcescens/aislamiento & purificación

RESUMEN

A total of 123 Shigella isolates were collected from SiXian area in Anhui, China. Screening was carried out by polymerase chain reaction (PCR) amplification of plasmid-mediated quinolone resistance (PMQR) determinants. Different ß-blactamases genes, plasmid-borne bla(AmpC), 16S rRNA methylase genes, integrons, and mutations in quinolone resistance-determining regions were analysed by PCR for the PMQR-positive isolates.

Asunto(s)

Ciprofloxacina/farmacología , Farmacorresistencia Bacteriana Múltiple , Plásmidos/genética , Shigella/efectos de los fármacos , Antibacterianos/farmacología , Proteínas Bacterianas/genética , China/epidemiología , Girasa de ADN/genética , Topoisomerasa de ADN IV/genética , Disentería Bacilar/epidemiología , Disentería Bacilar/microbiología , Genes Bacterianos , Genes de ARNr , Humanos , Integrones , Mutación , Reacción en Cadena de la Polimerasa/métodos , ARN Ribosómico 16S/genética , Shigella/genética , Shigella/aislamiento & purificación , beta-Lactamasas/genética

RESUMEN

OBJECTIVES: To test the mutant selection window (MSW) hypothesis with Staphylococcus aureus exposed to vancomycin in an animal model and to compare in vivo and in vitro exposures that restrict the enrichment of resistant mutants. METHODS: Local infection with S. aureus was established in rabbits, and the infected animals were treated with various doses of twice-daily vancomycin (half-life 6 h) for 3 consecutive days to provide antibiotic concentrations below the MIC, between the MIC and the mutant prevention concentration (MPC), and above the MPC. Changes in susceptibility and the numbers of surviving organisms were monitored daily on agar plates containing 2× and 4× MIC of vancomycin. RESULTS: S. aureus lost vancomycin susceptibility when drug concentrations at the site of infection fluctuated between the lower and upper boundaries of the MSW, defined in vitro as the MIC(99) and the MPC, respectively. Both boundaries were determined in vitro, before starting animal studies. The value at which resistant mutants are not enriched in vivo was estimated as an AUC(24)/MPC value of ∼15 h, where AUC(24) is the area under the drug concentration time curve in a 24 h interval. The estimated anti-mutant AUC/MIC ratio in vivo was ≥200 h. CONCLUSIONS: These findings support the MSW hypothesis and the anti-mutant AUC/MIC ratio estimated in vivo is consistent with that reported in in vitro studies. Keeping vancomycin concentrations above the MPC or AUC(24)/MPC >15 h is a straightforward way to restrict the acquisition of resistance.

Asunto(s)

Antibacterianos/uso terapéutico , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Infecciones Estafilocócicas/tratamiento farmacológico , Resistencia a la Vancomicina , Vancomicina/uso terapéutico , Animales , Modelos Animales de Enfermedad , Femenino , Pruebas de Sensibilidad Microbiana , Conejos , Factores de Tiempo

RESUMEN

By using emergy analysis method, a trend analysis was made on the total emergy, its input-output structure, and emergy indices of the agro-ecosystem in Hunan Province of South-central China from 1999 to 2008. In the study period, the available total emergy input of the ecosystem was basically maintained at a stable level, but the input structure changed with the input of non-renewable industrial auxiliary emergy increased from 4.00E+22 sej in 1999 to 5.53E+22 sej in 2008, while that of renewable organic emergy decreased from 1.32E+23 sej to 1.20E+23 sej. Both the total emergy output and the output efficiency of the ecosystem had a great increase, with the total output reached 1.69E+23 sej in 2008, which was 23.8% higher than that in 1999, and the net output ratio increased from 0.79 to 0.96. Owing to the ever-increasing trend of the environmental loading ratio which was from 1.12 to 1.79, the sustainable development index of the ecosystem presented a decreasing trend, from 0.71 to 0.54, indicating that the agriculture in Hunan Province was overall belonged to the type of ecosystem driven by high consumption, and had relatively apparent extensive development characteristics.

Asunto(s)

Agricultura/métodos , Conservación de los Recursos Naturales/métodos , Productos Agrícolas/crecimiento & desarrollo , Ecología/economía , Ecosistema , China , Conservación de los Recursos Naturales/economía , Ecología/tendencias , Monitoreo del Ambiente/métodos

RESUMEN

Clinical failures with vancomycin against meticillin-resistant Staphylococcus aureus (MRSA) infections have challenged vancomycin's standing as a first-line antimicrobial for these infections. Conventional MIC tests were not predictive of the in vivo therapeutic effect of vancomycin. Thus, we tested the susceptibility for the resistant mutants in the mutant selection window of S. aureus ATCC43300 (a MRSA strain) by three different MIC-testing methods in this paper. The MIC of vancomycin was estimated at 2 µg ml⁻¹ on the Mueller-Hinton agar (MHA) plate only for the resistant mutant that was selected from the plate of vancomycin concentration 12 µg ml⁻¹. The obvious changes of susceptibility testing were found between the resistant mutants and S. aureus ATCC43300 on the Brain-Heart Infusion Agar (BHIA) plates. There were subtle changes in the MIC trend within the susceptible range with the result of Etest for the resistant mutants. The susceptibility for the subcultures of resistant mutants would fall back when the external drug environment disappeared. In comparison with the S. aureus ATCC43300, sequence analysis revealed that there were no mutations in the staphylococcal protein A (spa) sequencing of the resistant mutants. The spa tape is t421 for all isolates.

Asunto(s)

Antibacterianos/farmacología , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Pruebas de Sensibilidad Microbiana/métodos , Infecciones Estafilocócicas/microbiología , Vancomicina/farmacología , ADN Bacteriano/química , ADN Bacteriano/genética , Humanos , Staphylococcus aureus Resistente a Meticilina/genética , Mutación , Análisis de Secuencia de ADN , Infecciones Estafilocócicas/tratamiento farmacológico

RESUMEN

OBJECTIVE: To investigate the impact of the ischemic postconditioning on the tumor necrosis factor (TNF)-α/IL-6/signal transducers and activators of transcription (STAT)-3 signal pathway of liver regeneration. METHODS: Ninety healthy clean grade male Sprague-Dawley rats weighting 230 to 280 g were selected and assigned into three groups randomly: group I subtotal hepatectomy (SH), group II ischemia reperfusion (IR), group III ischemic postconditioning (IPO). The left and middle liver was resected, and the remnant liver was treated as followed: the blood flow was not blocked in SH group, but blocked 30 minutes in IR group, then reperfused; IPO groups received three cycles of 30 s-30 s intermittent interruptions of blood flow at onset of reperfusion. At 1, 6, 12, 24, 48 h after reperfusion, the serum TNF-α, IL-6 was detected and the mRNA of cyclinD1, Cdk4, STAT-3 was assayed by real-time PCR as well as the protein expression of cyclinD1 and Cdk4 by Western blot. RESULTS: Compared with SH group, the expression of IL-6 declined at each set time point in IR group (t = 5.076 to 8.334, P = 0.000), but the content of TNF-α increased in early stage (1 to 12 h) (t = 2.972 to 7.215, P = 0.000 - 0.014). The expression of STAT-3, cyclinD1 and Cdk4 mRNA and protein of cyclinD1 and Cdk4 at 24 and 48 h after reperfusion were lower in IR group than in SH group (t = 2.857 to 6.684, P = 0.000 to 0.017). However, there was a significant decrease in TNF-α from 1 to 12 h after reperfusion (t = 2.995 to 4.112, P = 0.002 to 0.017), but a significant increase in IL-6 in IPO group than in IR group (t = 2.458 to 3.543, P = 0.005 to 0.034). The expression of STAT-3, cyclinD1, Cdk4 mRNA and protein of cyclinD1 and Cdk4 at 24 and 48 h after reperfusion were all increased in IPO group in comparison with in IR group (t = 2.383 to 6.803, P = 0.000 to 0.038). CONCLUSIONS: The ischemic postconditioning could promote the remnant liver regeneration after subtotal hepatectomy with ischemia reperfusion injury. Its mechanism relates with the activation of the TNF-α/IL-6/STAT-3 signal pathway of and the cyclinD1-Cdk4 complex which enhances the proliferation of hepatocyte.

Asunto(s)

Interleucina-6/metabolismo , Poscondicionamiento Isquémico , Regeneración Hepática , Hígado/metabolismo , Factor de Transcripción STAT3/metabolismo , Factor de Necrosis Tumoral alfa/metabolismo , Animales , Ciclina D1/metabolismo , Quinasa 4 Dependiente de la Ciclina/metabolismo , Hepatectomía , Masculino , Ratas , Ratas Sprague-Dawley , Transducción de Señal

RESUMEN

OBJECTIVE: To explore the effects of ischemic postconditioning on the remnant liver regeneration under ischemic reperfusion after subtotal hepatectomy. METHODS: A total of 90 male SD rats weighting 230-280 g were randomly divided into 3 groups of simple subtotal hepatectomy (SH), ischemia reperfusion (IR) and ischemic postconditioning (IPO). The left and middle liver lobes were resected. And the remnant liver was treated as follows: blood flow was non-blocked in SH group, but blocked for 30 min in IR group, then reperfused. The IPO group was established by 30-30 s intermittent interruptions of blood flow thrice during the early phase of reperfusion. At 1, 6, 12, 24, 48 h respectively, the serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), hepatocyte growth factor (HGF) and the positive ratio of proliferating cell nuclear antigen (PCNA) were detected. Also the contents of adenosine triphosphate (ATP), adenosine diphosphate (ADP) and adenosine monophosphate (AMP) were measured and the regenerated liver weight was calculated. RESULTS: The activities of ALT and AST in IPO group from 1 - 48 h were (138 ± 20), (340 ± 22), (770 ± 55), (389 ± 60), (113 ± 25) U/L and (247 ± 31), (509 ± 51), (972 ± 77), (955 ± 159), (222 ± 44) U/L respectively at each time point and they were significantly lower than those (294 ± 37), (560 ± 69), (1222 ± 162), (540 ± 40), (161 ± 15) U/L and (439 ± 34), (669 ± 94), (1347 ± 118), (1274 ± 223), (403 ± 68) U/L in IR group (P < 0.05); the regenerated liver weight (18.8 ± 3.2, 34.0 ± 3.5%) and positive cell ratio of PCNA (43.9 ± 2.7, 56.2 ± 4.0%) in IPO group at 24 and 48 h were respectively higher than those in IR group ((11.3 ± 2.9), (26.8 ± 2.5)% and (34.5 ± 2.8), (48.8 ± 1.8)%)(P < 0.05); The HGF levels ((261 ± 54) and (252 ± 103) pg/ml) at 24 and 48 h in IPO group were significantly higher than those ((99 ± 47) and (70 ± 19) pg/ml) in IR group (P < 0.05); the contents of ATP in hepatic tissue at 24 and 48 h in IPO group were (22.20 ± 3.6) and (12.87 ± 2.49) µg/g respectively. And they were significantly higher than those in IR group (P < 0.05), but lower than those in SH group (P < 0.05). CONCLUSION: Ischemic postconditioning improves the remnant liver regeneration under ischemic reperfusion after subtotal hepatectomy through its actions of stimulating HGF production and maintaining hepatic energy metabolism.

Asunto(s)

Metabolismo Energético , Poscondicionamiento Isquémico , Regeneración Hepática , Daño por Reperfusión/metabolismo , Animales , Factor de Crecimiento de Hepatocito/metabolismo , Masculino , Ratas , Ratas Sprague-Dawley

Asunto(s)

Puntos de Acupuntura , Terapia por Acupuntura , Traumatismos del Tobillo/terapia , Esguinces y Distensiones/terapia , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Preescolar , Femenino , Humanos , Masculino , Persona de Mediana Edad , Resultado del Tratamiento , Adulto Joven

RESUMEN

In the title mol-ecule, C(25)H(30)O(4), the two cyclo-hexene rings adopt envelope conformations. The two hy-droxy groups are involved in the formation of intra-molecular O-H⋯O hydrogen bonds. In the crystal structure, weak inter-molecular C-H⋯O hydrogen bonds link mol-ecules related by translation along the axis a into chains.