RESUMEN
Background: Psoriasis is a chronic inflammatory skin disease that has no cure. While the specific cause of psoriasis is unknown, interactions between immune cells and inflammatory cytokines are believed to be important in its pathogenesis. Thymic stromal lymphopoietin (TSLP) is a cytokine produced by epithelial cells that profoundly affects dendritic cells (DCs) and is involved in allergy and inflammatory diseases. In some studies, its expression is higher in the skin of psoriasis patients, whereas it is increased in treated psoriasis patients when compared with untreated patients in others. Aims: To investigate the role of TSLP in the pathogenesis of psoriasis. Study Design: In vitro and in vivo study. Methods: To investigate the effect of TSLP on psoriasis in vivo, a mouse psoriasis model and shRNA targeting TSLP to reduce its expression were used. Mouse primary bone marrow dendritic cells (BMDCs) were cultured in vitro and used to investigate the signaling pathways activated by TSLP. Results: We found that reducing TSLP expression in psoriasis skin alleviated disease severity. TSLP activated the Janus kinase (JAK)/SYK pathway in psoriatic skin. In vitro studies with BMDCs demonstrated that TSLP increased DC maturation through the JAK/SYK pathway and activated DCs-secreted cytokines that stimulated CD4+ T cells to develop into T helper 17 (Th17) cells by activating STAT3 signaling. The JAK/SYK pathway inhibitor reduced the effect of TSLP on activating BMDCs and promoting Th17 differentiation by CD4+ T cells. Conclusion: These findings indicated that TSLP exerted its immune-modulating effect in psoriasis through the JAK/SYK pathway.
Asunto(s)
Citocinas , Células Dendríticas , Psoriasis , Células Th17 , Linfopoyetina del Estroma Tímico , Animales , Humanos , Ratones , Citocinas/metabolismo , Citocinas/efectos de los fármacos , Células Dendríticas/efectos de los fármacos , Células Dendríticas/inmunología , Modelos Animales de Enfermedad , Quinasas Janus , Transducción de Señal/efectos de los fármacos , Quinasa Syk , Células Th17/efectos de los fármacos , Células Th17/inmunologíaRESUMEN
Leptospirosis, a globally significant zoonotic disease caused by pathogenic Leptospira, continues to threaten the health and public safety of both humans and animals. Current clinical treatment of leptospirosis mainly relies on antibiotics but their efficacy in severe cases is controversial. Passive immunization has a protective effect in the treatment of infectious diseases. In addition, chicken egg yolk antibody (IgY) has gained increasing attention as a safe passive immunization agent. This study aimed to investigate whether hens produce specific IgY after immunization with inactivated Leptospira and the protective effect of specific IgY against leptospirosis. First, it was demonstrated that specific IgY could be extracted from the eggs of hens vaccinated with inactivated Leptospira and that specific IgY can specifically recognize and bind homotypic Leptospira with a high titre, as shown by MAT and ELISA. Next, we tested the therapeutic effects of IgY in early and late leptospirosis using a hamster model. The results showed that early specific IgY treatment increased the survival rate of hamsters to 100%, alleviated pathological damage to the liver, kidney, and lung, reduced leptospiral burden, and restored haematological indices as well as functional indicators of the liver and kidney. The therapeutic effect of early specific IgY was comparable to that of doxycycline. Late IgY treatment also enhanced the survival rate of hamsters and improved the symptoms of leptospirosis similar to early IgY treatment. However, the therapeutic effect of late IgY treatment was better when combined with doxycycline. Furthermore, no Leptospira colonization was observed in the kidneys, livers, or lungs of the surviving hamsters treated with specific IgY. Mechanistically, IgY was found to inhibit the growth and adhesion to cells of Leptospira. In conclusion, passive immunotherapy with specific IgY can be considered an effective treatment for leptospirosis, and may replace antibiotics regarding its therapeutic effects.
Asunto(s)
Anticuerpos Antibacterianos , Inmunización Pasiva , Inmunoglobulinas , Leptospira , Leptospirosis , Animales , Cricetinae , Femenino , Anticuerpos Antibacterianos/inmunología , Pollos/inmunología , Modelos Animales de Enfermedad , Doxiciclina/uso terapéutico , Doxiciclina/administración & dosificación , Doxiciclina/farmacología , Yema de Huevo/inmunología , Inmunización Pasiva/métodos , Inmunoglobulinas/inmunología , Inmunoglobulinas/administración & dosificación , Riñón/patología , Riñón/inmunología , Riñón/microbiología , Leptospira/inmunología , Leptospirosis/inmunología , Leptospirosis/prevención & control , Leptospirosis/terapia , Hígado/inmunología , Hígado/patología , Hígado/microbiología , Mesocricetus , Vacunas de Productos Inactivados/inmunología , Vacunas de Productos Inactivados/administración & dosificaciónRESUMEN
The tendency of ovotransferrin (OVT) to unfold and aggregate under 60 °C severely restricted sterilization temperature during egg processing. Searching for efficient strategies to improve OVT thermal stability is essential for improving egg product quality and processing suitability. Here, we investigated the effect of sulfate polysaccharide (dextran sulfate, DS) on heat-induced aggregation of OVT. We found that DS can effectively suppress amorphous aggregation of OVT at pH 7.0 after heating. Strikingly, the addition of 5 µM DS fully suppressed insoluble aggregates formation of 0.5 mg/mL OVT. Structure analysis confirmed that DS preserves nearly the entire secondary and tertiary structure of OVT during heating. The steric hindrance effect arising from strong electrostatic interactions between OVT and DS, coupled with reduced OVT hydrophobicity, is the underlying mechanism in suppressing protein-protein interactions, thus enhancing thermal stability. These findings suggest DS could act as protein stabilizers and chaperones, enhancing the thermostability of heat-sensitive proteins.
Asunto(s)
Conalbúmina , Calor , Conalbúmina/química , Sulfato de Dextran , Temperatura , Electricidad EstáticaRESUMEN
The main hurdle in leveraging microfluidic advantages in membraneless MFCs is their low electrode area-normalized power. For nearly a decade, maximum power densities have remained stagnant, while at the same time macrosystems continue to gather pace. To bridge this growing gap, we showcase a strategy that focuses on (i) technology improvements, (ii) establishment of record areal power densities, and (iii) presentation of different normalization methods that complement areal power densities and enable direct comparisons across all MFC scales. Using a pure-culture Geobacter sulfurreducens electroactive biofilm (EAB) in a new membraneless MFC that adheres to the strategy above, we observed optimal anode colonization, resulting in the highest recorded electrode areal power density for a microfluidic MFC of 3.88 W m-2 (24.37 kW m-3). We also consider new power normalization methods that may be more appropriate for comparison to other works. Normalized by the wetted cross-section area between electrodes accounts for constraints in electrode/electrolyte contact, resulting in power densities as high as 8.08 W m-2. Alternatively, we present a method to normalize by the flow rate to account for acetate supply, obtaining normalized energy recovery values of 0.025 kW h m-3. With these results, the performance gap between micro- and macroscale MFCs is closed, and a road map to move forward is presented.
RESUMEN
This study aimed to design a cold-set hydrogel of egg white protein (EWP) with good mechanical properties for encapsulating curcumin. Dextran sulfate (DS) and transglutaminase (TGase) were used to control the aggregation and gelation behavior of EWP at preheating step and gelation step, respectively. The optimum soluble protein aggregate size was obtained in the EWP/DS mixture at a mass ratio of 10 under 85 °C preheated (HED10). The presence of TGase further enhanced the cross-linking degree between protein aggregates during the gelation step. The highest gel hardness was found in HED10 hydrogel with TGase, which is almost 10 times the pure EWP gel. Besides, the HED hydrogels effectively slowed down the release rate of curcumin in gastrointestinal digestion. This work provides a theoretical basis for the development of cold-set EWP hydrogel with good mechanical strength by sulfated polysaccharide addition and TGase cross-linking as encapsulation delivery systems.
Asunto(s)
Curcumina , Hidrogeles , Sulfato de Dextran , Proteínas del HuevoRESUMEN
BACKGROUND: Salmonella as an important food-borne zoonotic bacterial pathogen, infection in ducks is a recessive infection, however, it can also cause high mortality and threat to food safety. Preventing and controlling the infection and transmission of Salmonella in ducks critically require rapid and sensitive detection method. Full-length Salmonella-specific protein PagN was induced and expressed in E.coil BL21 and was purified as an antigen to establish an indirect enzyme-linked immunosorbent assays (iELSA) detection kit. RESULTS: The recombinant PagN protein has a molecular weight of 43 kDa containing a His-tag, was recognized by an anti-Salmonella positive serum by Western blot assay. The optimal concentration of PagN as a coating antigen in the iELISA was 1 µg/mL, and the optimal dilution of enzyme-labeled secondary antibody was 1:4000 (0.025 µg/mL). The cutoff OD450 value was established at 0.268. The iELISA kit showed high selectivity since no cross-reaction with E. coli, Staphylococcus aureus and Streptococcus was observed. iELISA method and Dot-blot test were performed on 100 clinical sera samples collected from duck farms, and the actual coincidence rate was 89% (89/100). 613 duck serum samples from 3 different farms were tested using established method and commercial ELISA kit. The concordance between the two methods was 94.1%. CONCLUSION: Anti-PagN based iELISA can serve as a useful tool for diagnosis of Salmonella infection.
Asunto(s)
Patos , Escherichia coli , Animales , Sensibilidad y Especificidad , Ensayo de Inmunoadsorción Enzimática/veterinaria , Ensayo de Inmunoadsorción Enzimática/métodos , Proteínas Recombinantes , Anticuerpos Antibacterianos , Anticuerpos AntiviralesRESUMEN
We report a case of a 7-year-old male patient with vaccine-induced erythrodermic psoriasis (EP) complicated by pulmonary infection, hypoproteinemia, and liver dysfunction successfully treated with secukinumab in combination with symptomatic and supportive therapy. The patient presented with diffuse flushing on the head, face, trunk, and limbs, which were covered with chaff-like white scales in the rash-affected area, with no blisters, pustules, and no apparent abnormalities in the palms, soles, nails, and joints. Histopathology analysis revealed hyperkeratosis, focal parakeratosis, thinning or effacement of the granular layer, psoriasiform hyperplasia of the epidermis, neutrophilic microabscess formation in the upper part of the epidermis, edema of the dermal papilla, dilation of blood vessels, and lymphocyte infiltration. The patient was eventually diagnosed with EP. At weeks 0, 1, and 2, the patient received a subcutaneous injection of 150 mg secukinumab (three injections). Fluticasone propionate ointment, taccathitol ointment, yellow vaseline, and other drugs were also given topically. Following 2 weeks of treatment, the child's skin lesions resolved significantly with only slight pigmentation remaining and the Psoriasis Area and Severity Index (PASI) score decreased from 37.5 to 7.5 (PASI 75). Thereafter, 150 mg secukinumab was injected every 4 weeks until the last dose at 18 weeks (four more injections). After 18 weeks, the child's lesion resolved entirely (PASI 100), and no adverse effects were reported.
Asunto(s)
Psoriasis , Vacunas , Anticuerpos Monoclonales/uso terapéutico , Anticuerpos Monoclonales Humanizados , Niño , Método Doble Ciego , Humanos , Inyecciones Subcutáneas , Masculino , Pomadas/uso terapéutico , Psoriasis/diagnóstico , Psoriasis/tratamiento farmacológico , Psoriasis/patología , Índice de Severidad de la Enfermedad , Resultado del TratamientoRESUMEN
A recent trend in microfluidic microbial fuel cells (MFCs) is to exclude a separation membrane, instead, relying on the physics of laminar flow to maintain isolation between anode and cathode compartments. To avoid solution crossover, the electrodes may be separated by distances of several millimeters, but this negatively affects the internal resistance and undermines a prime advantage of microscale MFCs. Therefore, we propose a facile method for in situ synthesis of a micromembrane that supports sub-millimeter electrode spacing. Membrane synthesis in situ reduces device fabrication complexity, and the proposed design avoids electrode contamination during its synthesis. Comparing results to a state-of-the-art membraneless MFC with 6 mm inter-electrode distances, the sub-millimeter membrane MFC under comparable flow conditions had an internal resistance that was 60% lower, power and current densities that were respectively 45% and 290% higher, and acetate conversion efficiencies that were 8 times higher. The enhanced flow stability provided stable operation under imbalanced flow conditions and delivered continuous increases to power density of up to 30% for flow rate increases of 100 times over baseline levels. As a result, maximum outputs obtained were 660 mW m-1 and 3.5 A m-1. These are the highest reported for microfluidic MFCs using pure culture bacteria, which advances the goal of competing with mainstream MFC formats.
Asunto(s)
Fuentes de Energía Bioeléctrica , Fuentes de Energía Bioeléctrica/microbiología , Electricidad , Electrodos , MicrofluídicaRESUMEN
MicroRNA-128 (miR-128) has been found to be dysregulated and might function as a tumour suppressor in various cancers, including ovarian cancer. However, the underlying mechanism of miR-128 in ovarian cancer has not been fully understood. The miR-128 and homeobox B8 (HOXB8) levels in clinical samples and cultured cell lines were measured using qRT-PCR and/or Western blot analysis. Cell proliferation was assessed using Cell Counting Kit-8 assay. Cell apoptosis was determined using flow cytometry. The association between miR-128 and HOXB8 was confirmed using dual-luciferase reporter assay. Results showed that decreased miR-128 expression and increased HOXB8 expression were observed in ovarian cancer tissues and cell lines. Transfection with miR-128 mimics suppressed the cell proliferation and enhanced paclitaxel sensitivity in ovarian cancer cell lines. miR-128 directly targeted HOXB8 in ovarian cancer cell lines. Knockdown of HOXB8 abolished the effects of miR-128 inhibitor on ovarian cancer cell proliferation and paclitaxel sensitivity. Summarily, miR-128 displayed a tumour suppressor role in ovarian cancer via targeting HOXB8. It is supposed that miR-128 might be effective for targeting therapy for ovarian cancer.
Asunto(s)
Carcinoma Epitelial de Ovario/tratamiento farmacológico , Carcinoma Epitelial de Ovario/metabolismo , Proteínas de Homeodominio/metabolismo , MicroARNs/metabolismo , Neoplasias Ováricas/metabolismo , Regiones no Traducidas 3' , Antineoplásicos Fitogénicos/farmacología , Apoptosis/efectos de los fármacos , Carcinoma Epitelial de Ovario/genética , Carcinoma Epitelial de Ovario/patología , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Resistencia a Antineoplásicos , Femenino , Proteínas de Homeodominio/biosíntesis , Proteínas de Homeodominio/genética , Humanos , MicroARNs/biosíntesis , MicroARNs/genética , Persona de Mediana Edad , Neoplasias Ováricas/tratamiento farmacológico , Neoplasias Ováricas/genética , Neoplasias Ováricas/patología , Paclitaxel/farmacologíaRESUMEN
Post-MI heart failure is characterized by structural remodeling, in which intramyocardial fibrosis takes a important part. Poly(ADP-ribose) polymerase 1 (PARP-1) is a extensive nuclear enzyme and plays a critical role in various diseases. It was shown that PARP-1 inhibition could alleviate heart failure and dowregulate autophagy, but whether PARP-1 regulates autophagy and thus impacts the activities of CFs remain unknown. We transfected cultured cardiac fibroblasts (CFs) with small interfere RNA-PARP-1 (siPARP-1) to downregulate PARP-1 and analyzed the ability of proliferation, migration, differentiation, and autophagy levels of CFs under different treatments using CCK8 assays, transwell migration assays, immunofluorescence assays detecting expression of α-SMA, western blot assays detecting autophagy-related proteins respectively. Furthermore, rat models of myocardial infarction (MI) were induced by ligation of left anterior descending coronary artery and PARP-1 inhibitor, 4-aminobenzamide (4-AB), was injected intraperitoneally after MI, followed by echocardiography detection, masson assays, immunohistochemistry assays detecting expression of α-SMA and western blot assays detecting autophagy-related proteins to investigate whether PARP-1 inhibition could regulate autophagy, alleviate cardiac fibrosis and improve cardiac function in vivo. In cultured CFs, siPARP-1 repressed TGF-ß1-induced proliferation, migration, and differentiation through regulating autophagic levels. The in vitro results was verified by the in vivo study, indicating that PARP-1 inhibition partially decreased autophagy, abrogated cardiac fibrosis and significantly improved cardiac function post-MI. In conclusion, this work demonstrated the vital connection of PARP-1 and autophagy in the activation of CFs, and provided solid evidence supporting PARP-1 inhibition as a feasible strategy for the treatment of post-MI heart failure.
Asunto(s)
Autofagia/efectos de los fármacos , Fibrosis/tratamiento farmacológico , Fibrosis/etiología , Infarto del Miocardio/complicaciones , Poli(ADP-Ribosa) Polimerasa-1/antagonistas & inhibidores , Animales , Fibrosis/enzimología , Fibrosis/patología , Masculino , Poli(ADP-Ribosa) Polimerasa-1/metabolismo , Ratas , Ratas Sprague-DawleyRESUMEN
A highly selective method is described for the colorimetric determination of Au(III) ions in acidic solution using gold nanoparticles (AuNPs) functionalized with thiolated methoxy poly(ethylene glycol) (mPEG). The presence of Au(III) induces the aggregation of the PEG-AuNPs, and this is accompanied by a color change from wine red to blue, and a decrease in absorbance at 525 nm. This can be monitored spectrophotometrically and visually. Absorbance at 525 nm linearly drops in the 0.50 to 1.75 mg·L-1 Au(III) concentration range, with a 0.25 mg·L-1 detection limit. The method is surprisingly selective over other metal ions. It was successfully applied to the analysis of ore samples. Graphical Abstract á .
RESUMEN
D-amino acid oxidases (DAAO) are stereospecific enzymes which are generally almost inactive towards L-enantiomer in neutral solution when L-, D-amino acids are supplied as substrates. In this paper, the D-amino acid oxidase can catalytic oxidize L-amino acids by modulating pH of aqueous solution. With L-Pro as substrate, the catalytic rate (k cat) and the affinity (K m) of DAAO were 6.71 s-1 and 33 mM at pH 8.0, respectively, suggesting that optimal pH condition enhanced the activity of DAAO towards L-Pro. Similar results were obtained when L-Ala (pH 9.8), L-Arg (pH 6.5), L-Phe (pH 9.0), L-Thr (pH 9.4), and L-Val (pH 8.5) were catalyzed by DAAO at various pH values. The racemization of the L-amino acids was not found by capillary electrophoresis analysis during oxidation, and quantification analysis of L-amino acids before and after catalytic reaction was performed, which confirmed that the modulation of enantioselectivity of DAAO resulted from the oxidation of L-amino acids rather than D-amino acids by changing pH. A mechanistic model was proposed to explain enhanced activity of DAAO towards L-amino acids under optimal pH condition.
Asunto(s)
D-Aminoácido Oxidasa/metabolismo , Concentración de Iones de Hidrógeno , Especificidad por Sustrato/efectos de los fármacos , Cinética , SolucionesRESUMEN
Implant-associated infections still pose a serious threat leading to several complications. This study reported an environmentally benign Ag-containing nanocomposite coating with efficient antibacterial property fabricated on the metal implant via electrophoretic deposition (EPD). In such coatings, Ag2O/AgCl mixed with chitosan/gelatin (CS/G) polymers work together to exert the antibacterial property which could act as an alternative to traditional Ag nanoparticles. Scanning electron microscopy images showed the shuttle fiber-like morphology distributed lamellarly and some nanoparticles carved uniformly into the cross section. Transmission electron microscopy results revealed a core-shell-like structure of the released nanoparticles in experimental groups. The Ag-containing coatings exhibited strong antibacterial properties against Staphylococcus aureus strains and Escherichia coli strains. Meanwhile, the CCK-8 tests showed that after assembling with chitosan and gelatin polymers, the cytotoxicity of Ag was largely decreased. In addition, such coatings also exhibited strong bond strength with metal substrates and good degradable properties. Therefore, such Ag-containing CS/G coatings fabricated via EPD may be a promising candidate to be administrated in controlling the implant-associated infections.
Asunto(s)
Antibacterianos/química , Antibacterianos/farmacología , Nanocompuestos/química , Plata/química , Animales , Antibacterianos/efectos adversos , Línea Celular , Quitosano/química , Escherichia coli/efectos de los fármacos , Gelatina/química , Tecnología Química Verde , Ratones , Microscopía Electrónica de Rastreo , Microscopía Electrónica de Transmisión , Nanocompuestos/toxicidad , Nanocompuestos/ultraestructura , Nanopartículas/ultraestructura , Staphylococcus aureus/efectos de los fármacosRESUMEN
BACKGROUND: Previous studies have thoroughly investigated the prevalence and risk factors for completed suicide. In marked contrast is the lack of a better understanding of attempted suicide in the elderly. The aim of this study was to estimate the prevalence of attempted suicide in the elderly and examine the associated factors. METHODS: Using a multi-stage cluster sampling approach, a cross-sectional survey of 8,399 elderly house-dwelling residents was conducted in Shanghai, China. RESULTS: The two-week prevalence of attempted suicide in the elderly was 0.75%. In the bivariate analysis, having no caregivers, depressive, anxiety, sad, fear, obsessive-compulsive and anger symptom, and lower scores on the Barthel Index of Activities of Daily Living and the Lawton Instrumental Activities of Daily Living Scale were significantly associated with an increased risk of attempted suicide in the elderly. In the multivariate analysis, sad and fear symptoms were significantly and independently associated with a higher risk of attempted suicide in the elderly. CONCLUSION: The two-week prevalence of attempted suicide in the elderly is relatively high when compared with the annualized or lifetime prevalence reported in China and foreign settings. Elderly individuals with certain mental symptoms should be targeted for suicide prevention and provided with timely mental health support.
Asunto(s)
Envejecimiento/psicología , Miedo/psicología , Pesar , Intento de Suicidio/estadística & datos numéricos , Anciano , Anciano de 80 o más Años , China/epidemiología , Estudios Transversales , Femenino , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Prevalencia , Escalas de Valoración Psiquiátrica , Factores de Riesgo , Intento de Suicidio/prevención & controlRESUMEN
BACKGROUND: Both multimorbidity and activities of daily living (ADL) disability and instrument activities of daily living (IADL) disability are common among elderly individuals. ADL/IADL disability may reduce individuals' capacities for independent living and quality of life. This study aimed to examine the association between multimorbidity and ADL/IADL disability. METHODS: A multi-stage cluster sample of 2058 residents aged 80 or older was investigated in Shanghai, China. Multimorbidity was defined as the simultaneous presence of two or more chronic diseases with ten common chronic conditions under consideration. Subjects who responded that they "need partial or full assistance" to any ADL/IADL items were defined as having ADL/IADL disability. We examined the association of multimorbidity with ADL/IADL disability, adjusted for socio-demographic characteristics by using logistic regression. RESULTS: Of respondents, 23.23 % had ADL disability, 37.90 % had IADL disability, and 49.17 % had multimorbidity. After adjusted socio-demographic characteristics, a graded association was showed between ADL disability and the quantity of chronic conditions: odds ratio (OR) for 1 condition, 1.53(95 % confidence interval [CI], 1.04-2.24); OR for 2 conditions, 2.06(95 % CI, 1.43-2.96); OR for 3 conditions, 3.23(95 % CI, 2.14-4.86); OR for 4 or more conditions, 5.61(95 % CI, 3.26-9.66). Similar associations were also observed between the quantity of chronic conditions and IADL disability. CONCLUSIONS: The quantity of chronic conditions had relatively strong association with both ADL and IADL disability. Initiating prevention of additional chronic conditions and interventions on clusters of diseases may decrease the potential risk of ADL/IADL disability. Additionally, more attention should been given to the older low-income women living with relatives/non-relatives with multimorbidity.
Asunto(s)
Actividades Cotidianas , Enfermedad Crónica/epidemiología , Comorbilidad , Personas con Discapacidad/estadística & datos numéricos , Actividades Cotidianas/psicología , Anciano de 80 o más Años , Envejecimiento , China/epidemiología , Enfermedad Crónica/psicología , Estudios Transversales , Evaluación de la Discapacidad , Personas con Discapacidad/psicología , Femenino , Humanos , Vida Independiente , Masculino , Calidad de VidaRESUMEN
Metal orthopedic implants still face challenges in some compromised conditions, partly due to bio-inertness. The present study aimed to functionalize metallic implants with organic-inorganic nanocomposite (strontium-containing chitosan/gelatin) coatings through a simple single-step electrophoretic deposition under mild conditions. The surface characterization and in vitro cellular response were studied and compared with chitosan/gelatin (CS/G) coatings. SEM images suggested the inorganic nanoparticles may be encapsulated within or mixed with organic polymers. The XRD patterns showed that strontium carbonate was generated in the coatings. The TEM images revealed strontium-containing nanoparticles were released from the coatings in PBS. The continuous release after the initial burst release ensured the enduring effects of the functionalized surface. The tensile bond strength of the coatings to the substrates increased after the addition of strontium. In vitro cellular study confirmed that strontium-containing coatings supported the proliferation of MC3T3-E1 cells and exhibited excellent ability to enhance the differentiation of such pre-osteoblasts. Therefore, such organic-inorganic nanocomposite coatings are a promising candidate to functionalize orthopedic implant surfaces.
Asunto(s)
Quitosano/química , Materiales Biocompatibles Revestidos/química , Electroforesis/métodos , Gelatina/química , Nanocompuestos/química , Osteoblastos/citología , Estroncio/química , Animales , Carbonatos , Diferenciación Celular , Proliferación Celular , Células Cultivadas , Ratones , Propiedades de Superficie , Difracción de Rayos XRESUMEN
Titanium and its alloys have been widely used in clinic and achieved great success. Due to the bio-inertness of titanium surface, challenges still exit in some compromised conditions. The present study aimed to functionalize titanium surface with magnesium (Mg)-doped chitosan/gelatin (CS/G) nanocompound coatings via electrophoretic deposition (EPD). CS/G coatings loaded with different amount of magnesium were successfully prepared on titanium substrate via EPD. Physicochemical characterization of the coatings confirmed that magnesium ions were loaded into the coatings in a dose-dependent manner. XRD results demonstrated that co-deposition of magnesium influenced the crystallinity of the coatings, and a new crystalline substance presented, namely hydrated basic magnesium carbonate. Mechanical tests showed improved tensile and shear bond strength of the magnesium-doped coatings, while the excessively high magnesium concentration could eventually decrease the bonding strength. Sustained release of magnesium ion was detected by ICP-OES within 28 days. TEM images also displayed that nanoparticles could be released from the coatings. In vitro cellular response assays demonstrated that the Mg-doped nanocompound coatings could enhance the proliferation and osteogenic differentiation of MC3T3-E1 cells compared to CS/G coatings. Therefore, it could be concluded that Mg-doped CS/G nanocompound coatings were successfully fabricated on titanium substrates via EPD. It would be a promising candidate to functionalize titanium surface with such organic-inorganic nanocompound coatings.
Asunto(s)
Quitosano/química , Materiales Biocompatibles Revestidos/química , Magnesio/química , Titanio/química , Células 3T3 , Animales , Calcio/química , Diferenciación Celular , Gelatina/química , Ratones , Microscopía Electrónica de Rastreo , Nanopartículas/química , Osteoblastos/citología , Osteogénesis , Prótesis e ImplantesRESUMEN
The prevalently used immunoassays for fast screening of aftatoxins (AFs) usually cannot meet the requirement for simultaneous determination of total AFs (aflatoxin B1 + aflatoxin B2 + aflatoxin G1 + aflatoxin G2) due to the deficiency of highly group-specific antibodies. This paper describes a two-step chromogenic reaction based method to quantitatively detect total AFs in rice using colorimetric measurement without antibody. In the method, colorless AFs transform into green-colored indophenol products through the reaction with sodium hydroxide and 2,6-dibromoquinone-4-chloroimide (DBQC) successively, allowing selectively determining total AFs up to 3.9 µg/kg over other competitive mycotoxins under optimal conditions by a UV-vis spectrophotometer. In addition, the colorimetric measurement results of the rice samples agree well with that of a standard HPLC method, demonstrating the good reliability and applicability of the method. Uniquely, the method has potential for on-site detection of total AFs in rice when using a nylon membrane-based device.
Asunto(s)
Aflatoxinas/análisis , Colorimetría/métodos , Oryza/química , Aflatoxinas/química , Indofenol/análogos & derivados , Indofenol/síntesis química , Límite de Detección , Quinonas/química , Hidróxido de Sodio/químicaRESUMEN
Evolution of pest resistance reduces the efficacy of insecticidal proteins from the gram-positive bacterium Bacillus thuringiensis (Bt) used widely in sprays and transgenic crops. Recent efforts to delay pest adaptation to Bt crops focus primarily on combinations of two or more Bt toxins that kill the same pest, but this approach is often compromised because resistance to one Bt toxin causes cross-resistance to others. Thus, integration of Bt toxins with alternative controls that do not exhibit such cross-resistance is urgently needed. The ideal scenario of negative cross-resistance, where selection for resistance to a Bt toxin increases susceptibility to alternative controls, has been elusive. Here we discovered that selection of the global crop pest, Helicoverpa armigera, for >1000-fold resistance to Bt toxin Cry1Ac increased susceptibility to abamectin and spineotram, insecticides derived from the soil bacteria Streptomyces avermitilis and Saccharopolyspora spinosa, respectively. Resistance to Cry1Ac did not affect susceptibility to the cyclodiene, organophospate, or pyrethroid insecticides tested. Whereas previous work demonstrated that the resistance to Cry1Ac in the strain analyzed here is conferred by a mutation disrupting an ATP-binding cassette protein named ABCC2, the new results show that increased susceptibility to abamectin is genetically linked with the same mutation. Moreover, RNAi silencing of HaABCC2 not only decreased susceptibility to Cry1Ac, it also increased susceptibility to abamectin. The mutation disrupting ABCC2 reduced removal of abamectin in live larvae and in transfected Hi5 cells. The results imply that negative cross-resistance occurs because the wild type ABCC2 protein plays a key role in conferring susceptibility to Cry1Ac and in decreasing susceptibility to abamectin. The negative cross-resistance between a Bt toxin and other bacterial insecticides reported here may facilitate more sustainable pest control.
Asunto(s)
Transportadoras de Casetes de Unión a ATP/genética , Bacillus thuringiensis/genética , Proteínas Bacterianas/metabolismo , Endotoxinas/metabolismo , Proteínas Hemolisinas/metabolismo , Transportadoras de Casetes de Unión a ATP/metabolismo , Animales , Productos Agrícolas/genética , Insecticidas/metabolismo , Larva/genética , Mutación/genéticaRESUMEN
OBJECTIVES: Disability, which has been proved to be associated with suicide and suicidal ideation, has received little attention in relation to suicidal attempts among the elderly. The aim of this study was to explore the influence of disability on attempted suicide within this demographic. METHOD: A multi-stage cluster sample of 8399 residents aged 60 or more was investigated from 15 communities in Shanghai, China. Disability was measured using the Lawton instrumental activities of daily living (IADL) scale. RESULTS: The prevalence of attempted suicide in the elderly was 0.75%. Specific IADL disabilities, including shopping (OR = 3.01, 95% CI = 1.56-5.81), preparing meals (OR = 4.12, 95% CI = 2.12-8.00), housekeeping (OR = 2.48, 95% CI = 1.01-6.06), doing laundry (OR = 2.82, 95% CI = 1.09-7.35), using transport (OR = 3.10, 95% CI = 1.36-6.99) and medical care (OR = 4.41, 95% CI = 2.10-9.17), were significantly and independently associated with attempted suicide in the elderly. The presence of at least one such disability was associated with an almost threefold increase in the attempted suicide rate, and the presence of five or more IADL disabilities was associated with an approximate fivefold increase in the attempted suicide rate. CONCLUSION: Specific IADL disabilities, such as preparing meals or dealing with medical care, may be significant predictive factors for risk of suicidal attempts among the elderly. Therefore, elderly people with certain disabilities should be considered for suicide prevention interventions and should be supported in IADL as much as possible.