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1.
Langmuir ; 40(35): 18503-18511, 2024 Sep 03.
Artículo en Inglés | MEDLINE | ID: mdl-39177148

RESUMEN

Proton exchange membrane fuel cells (PEMFCs) for automotive applications are required to achieve mechanical reliability at various temperatures ranging from subfreezing to 80 °C. The thermal behavior of the electrode should be considered at the initial design stage to design a robust automotive fuel cell electrode. Recently, a behavior different from that of the bulk state has been reported for ionomers with a few nanometers of thickness. Therefore, the intrinsic thermal behavior of ionomer films with thicknesses from micrometers to nanometers is quantitatively investigated in this study. By introducing the fabrication of a pseudo-freestanding Nafion thin film and in-plane thermal strain measurement method on the water surface, the thermal expansion of the freestanding Nafion thin film was successfully measured with minimizing substrate constraints. Thermal strain measurement and X-ray scattering studies revealed that the weakening of intermolecular interaction within the hydrophobic and hydrophilic domains in the Nafion thin film caused thermal expansion, and well-structured hydrophobic domains could suppress thermal expansion. The thermal expansion behavior with different heat treatments provides evidence of the thin-film-to-bulk transition of the fully hydrated Nafion film. Intrinsic thermal behavior without substrate interactions can facilitate an understanding of the thermal behavior of electrodes and provide insight into designing a robust PEMFC in temperature-varying environments.

2.
Med Sci Monit ; 30: e943036, 2024 Feb 03.
Artículo en Inglés | MEDLINE | ID: mdl-38308426

RESUMEN

BACKGROUND This subgroup analysis of prospective observational research, involving 71 participants, compared the effects of anesthesia on microvascular reactivity in obese vs lean individuals using near-infrared spectroscopy and vascular occlusion tests. The correlation between the body mass index (BMI) and microvascular reactivity under general anesthesia was also investigated. MATERIAL AND METHODS This study enrolled adult patients classified as American Society of Anesthesiologists physical status I or II, undergoing elective surgery under general anesthesia. The microcirculatory variables measured before (Tpre) and 30 min following the induction of anesthesia (Tpost) were as follows: baseline tissue oxygen saturation (StO2), occlusion slope (∇occl), and recovery slope (∇recov). The patients were grouped according to their BMI (lean [BMI <25 kg/m²] vs obese [BMI ≥25 kg/m²]). Data are presented as medians and interquartile ranges. RESULTS There were 43 patients in the lean group and 28 in the obese group. At Tpre, baseline StO2, ∇occl, and ∇recov were not different between the 2 groups (P=0.860, 0.659, and 0.518, respectively). At Tpost, the baseline StO2 and ∇occl were not different between the 2 groups (P=0.343 and 0.791); however, the ∇recov was lower in the obese group than in the lean group (3.245 [2.737, 3.977] vs 4.131 [3.491, 4.843], P=0.003). At Tpost, BMI showed a moderate correlation with ∇recov (correlation coefficient: -0.319, P=0.007). CONCLUSIONS In obese patients, capillary recruitment capacity during general anesthesia is compromised compared to lean patients.


Asunto(s)
Obesidad , Enfermedades Vasculares , Adulto , Humanos , Anestesia General , Índice de Masa Corporal , Capilares , Microcirculación , Estudios Observacionales como Asunto
3.
BMC Oral Health ; 24(1): 1102, 2024 Sep 17.
Artículo en Inglés | MEDLINE | ID: mdl-39289711

RESUMEN

BACKGROUND/PURPOSE: This retrospective immunohistological pilot study aimed to investigate the influence of natural killer group 2, member D (NKG2D) ligand expression on ameloblastoma recurrence after surgical resection. It also aimed to elucidate additional clinical factors that could serve as predictors of ameloblastoma recurrence. MATERIALS AND METHODS: This study included 96 patients who were histologically diagnosed with ameloblastoma after surgical resection. The expression of NKG2D ligands, including UL16-binding proteins (ULBPs) 1-3 and major histocompatibility complex class I chain-related molecule (MIC) A/B, was evaluated in formalin-fixed paraffin-embedded tumor tissues via immunohistochemistry assays. Furthermore, the patients' electronic medical records were reviewed. Multivariate Cox regression analysis was conducted, and data were expressed as adjusted hazard ratios [HRs] with 95% confidence intervals [95% CIs]. RESULTS: Multivariate analysis revealed that recurrent tumors (ref.: primary; adjusted HR [95% CI]: 2.780 [1.136, 6.803], p = 0.025) and positive MICA/B expression (ref.: negative; adjusted HR [95% CI]: 0.223 [0.050, 0.989], p = 0.048) independently affected recurrence-free survival in ameloblastoma. CONCLUSION: This study identified recurrent cases and loss of MICA/B expression as independent predictors of early ameloblastoma recurrence following surgical resection. The findings suggest that decreased MICA/B expression might undermine NKG2D-mediated tumor immunosurveillance, thereby influencing early recurrence.


Asunto(s)
Ameloblastoma , Recurrencia Local de Neoplasia , Humanos , Estudios Retrospectivos , Masculino , Femenino , Recurrencia Local de Neoplasia/patología , Proyectos Piloto , Persona de Mediana Edad , Ameloblastoma/patología , Ameloblastoma/metabolismo , Ameloblastoma/cirugía , Adulto , Subfamilia K de Receptores Similares a Lectina de Células NK/metabolismo , Anciano , Inmunohistoquímica , Adolescente , Neoplasias Maxilomandibulares/patología , Neoplasias Maxilomandibulares/metabolismo , Neoplasias Maxilomandibulares/cirugía , Adulto Joven
4.
Proc Natl Acad Sci U S A ; 117(46): 28743-28753, 2020 11 17.
Artículo en Inglés | MEDLINE | ID: mdl-33139572

RESUMEN

Mammalian brain glycome remains a relatively poorly understood area compared to other large-scale "omics" studies, such as genomics and transcriptomics due to the inherent complexity and heterogeneity of glycan structure and properties. Here, we first performed spatial and temporal analysis of glycome expression patterns in the mammalian brain using a cutting-edge experimental tool based on liquid chromatography-mass spectrometry, with the ultimate aim to yield valuable implications on molecular events regarding brain functions and development. We observed an apparent diversity in the glycome expression patterns, which is spatially well-preserved among nine different brain regions in mouse. Next, we explored whether the glycome expression pattern changes temporally during postnatal brain development by examining the prefrontal cortex (PFC) at different time point across six postnatal stages in mouse. We found that glycan expression profiles were dynamically regulated during postnatal developments. A similar result was obtained in PFC samples from humans ranging in age from 39 d to 49 y. Novel glycans unique to the brain were also identified. Interestingly, changes primarily attributed to sialylated and fucosylated glycans were extensively observed during PFC development. Finally, based on the vast heterogeneity of glycans, we constructed a core glyco-synthesis map to delineate the glycosylation pathway responsible for the glycan diversity during the PFC development. Our findings reveal high levels of diversity in a glycosylation program underlying brain region specificity and age dependency, and may lead to new studies exploring the role of glycans in spatiotemporally diverse brain functions.


Asunto(s)
Metabolismo de los Hidratos de Carbono , Polisacáridos/biosíntesis , Corteza Prefrontal/metabolismo , Adolescente , Adulto , Animales , Niño , Preescolar , Glicómica , Humanos , Lactante , Recién Nacido , Masculino , Ratones , Corteza Prefrontal/crecimiento & desarrollo , Adulto Joven
5.
Int J Mol Sci ; 24(16)2023 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-37628993

RESUMEN

Inotodiol, a lanostane-type triterpenoid, and many phytochemicals from Chaga mushrooms have been investigated for various allergic diseases. However, the anti-aging and anti-inflammatory activities of inotodiol under different types of oxidative stress and the impact of inotodiol on collagen and hyaluronan synthesis have not been sufficiently studied. Lanostane triterpenoids-rich concentrate, which contained 10% inotodiol as major (inotodiol concentrate), was prepared from Chaga and compared with pure inotodiol in terms of anti-inflammatory activities on a human keratinocyte cell line, HaCaT cells, under various stimulations such as stimulation with ultraviolet (UV) B or tumor necrosis factor (TNF)-α. In stimulation with TNF-α, interleukin (IL)-1ß, IL-6, and IL-8 genes were significantly repressed by 0.44~4.0 µg/mL of pure inotodiol. UVB irradiation induced the overexpression of pro-inflammatory cytokines, but those genes were significantly suppressed by pure inotodiol or inotodiol concentrate. Moreover, pure inotodiol/inotodiol concentrate could also modulate the synthesis of collagen and hyaluronic acid by controlling COL1A2 and HAS2/3 expression, which implies a crucial role for pure inotodiol/inotodiol concentrate in the prevention of skin aging. These results illuminate the anti-inflammatory and anti-aging effects of pure inotodiol/inotodiol concentrate, and it is highly conceivable that pure inotodiol and inotodiol concentrate could be promising natural bioactive substances to be incorporated in therapeutic and beautifying applications.


Asunto(s)
Células HaCaT , Triterpenos , Humanos , Triterpenos/farmacología , Queratinocitos , Estrés Oxidativo , Esteroides
6.
Biotechnol Lett ; 44(7): 823-830, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35727401

RESUMEN

OBJECTIVE: To investigate the application of carbon catabolite repression (CCR) relaxed Lactobacillus brevis ATCC 14869 in the utilization of agar hydrolysate to produce bioethanol and lactic acid through fermentation. RESULTS: As a single carbon source, galactose was not metabolized by L. brevis. However, L. brevis consumed galactose simultaneous to glucose and ceased cell growth after depletion of glucose. For complete use of galactose from agar hydrolysis, glucose need to be periodically replenished into the growth medium. Overall, L. brevis successfully used agar hydrolysate and produced 17.2 g/L of ethanol and 31.9 g/L of lactic acid. The maximum specific cell growth rate on galactose and glucose mixture was the same with the glucose-only medium at 0.12 h-1. The molar product yields from glucose for lactic acid and ethanol were 1.02 and 0.95 respectively, equal to values obtained from the simultaneous utilization of glucose and galactose. CONCLUSION: In contribution to the ongoing efforts to utilize marine biomass, the relaxed CCR in Lactobacillus brevis ATCC 14869 was herein exploited to produce bioethanol and lactic acid from red seaweed hydrolysates.


Asunto(s)
Levilactobacillus brevis , Agar , Etanol , Fermentación , Galactosa , Glucosa , Ácido Láctico
7.
Molecules ; 27(15)2022 Jul 23.
Artículo en Inglés | MEDLINE | ID: mdl-35897881

RESUMEN

Chaga mushroom (Inonotus obliquus) comprises polyphenolic compounds, triterpenoids, polysaccharides, and sterols. Among the triterpenoid components, inotodiol has been broadly examined because of its various biological activities. The purpose of this study is to examine inotodiol from a safety point of view and to present the potential possibilities of inotodiol for medical usage. From chaga mushroom extract, crude inotodiol (INO20) and pure inotodiol (INO95) were produced. Mice were treated with either INO20 or INO95 once daily using oral administration for repeated dose toxicity evaluation. Serum biochemistry parameters were analyzed, and the level of pro-inflammatory cytokines in the serum was quantified. In parallel, the effect of inotodiol on food allergic symptoms was investigated. Repeated administration of inotodiol did not show any mortality or abnormalities in organs. In food allergy studies, the symptoms of diarrhea were ameliorated by administration with INO95 and INO20. Furthermore, the level of MCPT-1 decreased by treatment with inotodiol. In this study, we demonstrated for the first time that inotodiol does not cause any detrimental effect by showing anti-allergic activities in vivo by inhibiting mast cell function. Our data highlight the potential to use inotodiol as an immune modulator for diseases related to inflammation.


Asunto(s)
Lanosterol , Triterpenos , Animales , Antiinflamatorios/farmacología , Antiinflamatorios/uso terapéutico , Modelos Animales de Enfermedad , Inonotus , Lanosterol/análogos & derivados , Lanosterol/farmacología , Ratones
8.
Anal Bioanal Chem ; 413(20): 5227-5237, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-34235565

RESUMEN

Sialic acid Neu5Gc, a non-human glycan, is recognized as a new harmful substance that can cause vascular disease and cancer. Humans are unable to synthesize Neu5Gc due to a genetic defect that converts Neu5Ac to Neu5Gc, but Neu5Gc is often observed in human biological samples. Therefore, the demand for accurately measuring the amount of Neu5Gc present in human blood or tissues is rapidly increasing, but there is still no method to reliably quantify trace amounts of a non-human sugar. In particular, selective isolation and detection of Neu5Gc from human serum is analytically challenging due to the presence of excess sialic acid Neu5Ac, which has physicochemical properties very similar to Neu5Gc. Herein, we developed the label-free approach based on ZIC-HILIC/MRM-MS that can enrich sialic acids released from human serum and simultaneously monitor Neu5Ac and Neu5Gc. The combination of complete separation of Neu5Gc from abundant Neu5Ac by hydrophilic and electrostatic interactions with selective monitoring of structure-specific cross-ring cleavage ions generated by negative CID-MS/MS was remarkably effective for quantification of Neu5Ac and Neu5Gc at the femtomole level. Indeed, we were able to successfully determine the absolute quantitation of Neu5Gc from 30 healthy donors in the range of 3.336 ± 1.252 pg/µL (mean ± SD), 10,000 times lower than Neu5Ac. In particular, analysis of sialic acids in protein-free serum revealed that both Neu5Ac and Neu5G are mostly bound to proteins and/or lipids, but not in free form. In addition, the correlation between expression level of Neu5Gc and biological factors such as BMI, age, and sex was investigated. This method can be widely used in studies requiring sialic acid-related measurements such as disease diagnosis or prediction of immunogenicity in biopharmaceuticals as it is both fast and highly sensitive.


Asunto(s)
Espectrometría de Masas/métodos , Ácidos Siálicos/sangre , Conformación de Carbohidratos , Humanos , Sensibilidad y Especificidad , Ácidos Siálicos/química , Electricidad Estática
9.
J Dairy Sci ; 104(6): 6496-6507, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-33685684

RESUMEN

Human milk lipids provide not only energy but also indispensable bioactive components such as essential fatty acids. To establish the recommended daily intake value and guidelines for infant formula, a reference library of fatty acid composition has been generated from 4 Asian countries (South Korea, China, Vietnam, and Pakistan). Regardless of country, palmitic acid (C16:0), linoleic acid (C18:1), and linolenic acid (C18:2) were the 3 most abundant fatty acids in human milk and account for more than 75% of total fatty acids (total FA). However, there were several considerable differences between fatty acids, particularly n-3 and n-6 (omega-3 and omega-6) groups. Chinese mothers' milk had a high concentration of linoleic acid at 24.38 ± 10.02% of total FA, which may be due to maternal diet. Among the 4 countries, Pakistani mothers' milk contained a high amount of saturated fatty acid (56.83 ± 5.96% of total FA), and consequently, polyunsaturated fatty acids, including n-3 and n-6, were significantly lower than in other countries. It is noteworthy that docosahexaenoic acid (DHA) in Pakistani mothers' milk was 44.8 ± 33.3 mg/L, which is only 25 to 30% of the levels in the other 3 countries, suggesting the need for DHA supplementation for infants in Pakistan. Moreover, the ratio of n-6 to n-3 was also remarkably high in Pakistani mothers' milk (15.21 ± 4.96), being 1.4- to 1.7-fold higher than in other countries. The average DHA:ARA ratio in Asian human milk was 1.01 ± 0.79. Korean mothers' milk showed a high DHA:ARA ratio, with a value of 1.30 ± 0.98, but Pakistani mothers' milk had a significantly lower value (0.42 ± 0.12). The fatty acid compositions and anthropometric data of mother (body mass index, age) did not show any correlation. The obtained data might provide information about human milk compositions in the Asian region that could benefit from setting up recommended nutrient intake and infant formula for Asian babies.


Asunto(s)
Ácidos Grasos , Leche Humana , Animales , Asia , China , Ácidos Docosahexaenoicos , Femenino , República de Corea , Vietnam
10.
Expert Rev Proteomics ; 17(2): 109-117, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-32149536

RESUMEN

Introduction: Gastric cancer (GC) is one of the leading causes of cancer-related death worldwide because of difficulties in early diagnosis. Aberrant glycosylation in serum proteins has been associated with many human diseases. Serum haptoglobin, a highly sialylated glycoprotein with four N-glycosylation sites, has gained considerable attention due to its potential as a signature molecule to display aberrant glycosylation in inflammatory disorders and various types of cancer. In particular, the relevance of haptoglobin glycosylation in GC has been investigated in a multifaceted way.Areas covered: The screening of haptoglobin glycosylation could offer an alternative approach toward GC diagnosis and detection. In this report, various assay platforms such as glycan profiling, site-specific glycopeptide profiling, and intact protein profiling are introduced for the detection of abnormal glycosylation of serum haptoglobin.Expert opinion: Although aberrant glycosylation of serum haptoglobin is associated with gastric cancer patients and might be a promising marker of GC screening, the development of a diagnosis platform to increase specificity and sensitivity for clinical use is still an analytical challenge. However, the continuous advancement of analytical technologies and methods will spur the paradigm shift from traditional serum markers, enabling the effective mining of human glycoproteome for GC diagnostic markers.


Asunto(s)
Biomarcadores de Tumor/sangre , Haptoglobinas/metabolismo , Procesamiento Proteico-Postraduccional , Neoplasias Gástricas/sangre , Glicosilación , Humanos , Neoplasias Gástricas/diagnóstico
11.
Sensors (Basel) ; 20(16)2020 Aug 14.
Artículo en Inglés | MEDLINE | ID: mdl-32823956

RESUMEN

The use of human gesturing to interact with devices such as computers or smartphones has presented several problems. This form of interaction relies on gesture interaction technology such as Leap Motion from Leap Motion, Inc, which enables humans to use hand gestures to interact with a computer. The technology has excellent hand detection performance, and even allows simple games to be played using gestures. Another example is the contactless use of a smartphone to take a photograph by simply folding and opening the palm. Research on interaction with other devices via hand gestures is in progress. Similarly, studies on the creation of a hologram display from objects that actually exist are also underway. We propose a hand gesture recognition system that can control the Tabletop holographic display based on an actual object. The depth image obtained using the latest Time-of-Flight based depth camera Azure Kinect is used to obtain information about the hand and hand joints by using the deep-learning model CrossInfoNet. Using this information, we developed a real time system that defines and recognizes gestures indicating left, right, up, and down basic rotation, and zoom in, zoom out, and continuous rotation to the left and right.


Asunto(s)
Gestos , Mano , Holografía , Reconocimiento de Normas Patrones Automatizadas , Sistemas de Computación , Humanos
12.
Anal Bioanal Chem ; 410(6): 1617-1629, 2018 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-29285644

RESUMEN

Gastric cancer (GC) is one of the leading causes of cancer-related death worldwide, largely because of difficulties in early diagnosis. Despite accumulating evidence indicating that aberrant glycosylation is associated with GC, site-specific localization of the glycosylation to increase specificity and sensitivity for clinical use is still an analytical challenge. Here, we created an analytical platform with a targeted glycoproteomic approach for GC biomarker discovery. Unlike the conventional glycomic approach with untargeted mass spectrometric profiling of released glycan, our platform is characterized by three key features: it is a target-protein-specific, glycosylation-site-specific, and structure-specific platform with a one-shot enzyme reaction. Serum haptoglobin enriched by immunoaffinity chromatography was subjected to multispecific proteolysis to generate site-specific glycopeptides and to investigate the macroheterogeneity and microheterogeneity. Glycopeptides were identified and quantified by nano liquid chromatography-mass spectrometry and nano liquid chromatography-tandem mass spectrometry. Ninety-six glycopeptides, each corresponding to a unique glycan/glycosite pairing, were tracked across all cancer and control samples. Differences in abundance between the two groups were marked by particularly high magnitudes. Three glycopeptides exhibited exceptionally high control-to-cancer fold changes along with receiver operating characteristic curve areas of 1.0, indicating perfect discrimination between the two groups. From the results taken together, our platform, which provides biological information as well as high sensitivity and reproducibility, may be useful for GC biomarker discovery. Graphical abstract ᅟ.


Asunto(s)
Glicopéptidos/análisis , Haptoglobinas/química , Proteómica/métodos , Neoplasias Gástricas/diagnóstico , Espectrometría de Masas en Tándem/métodos , Biomarcadores de Tumor/análisis , Biomarcadores de Tumor/sangre , Glicosilación , Humanos , Modelos Moleculares , Proteolisis , Neoplasias Gástricas/sangre , Neoplasias Gástricas/química
13.
Appl Microbiol Biotechnol ; 101(3): 1111-1120, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-27664160

RESUMEN

The main carbohydrate of red macroalgae is agarose, a heterogeneous polysaccharide composed of D-galactose and 3,6-anhydro-L-galactose. When saccharifying agarose by enzymes, the unique physical properties of agarose, namely the sol-gel transition and the near-insolubility of agarose in water, limit the accessibility of agarose to the enzymes. Due to the lower accessibility of agarose to enzymes in the gel state than to the sol state, it is important to prevent the sol-gel transition by performing the enzymatic liquefaction of agarose at a temperature higher than the sol-gel transition temperature of agarose. In this study, a thermostable endo-type ß-agarase, Aga16B, originating from Saccharophagus degradans 2-40T, was characterized and introduced in the liquefaction process. Aga16B was thermostable up to 50 °C and depolymerized agarose mainly into neoagarooligosaccharides with degrees of polymerization 4 and 6. Aga16B was applied to enzymatic liquefaction of agarose at 45 °C, which was above the sol-gel transition temperature of 1 % (w/v) agarose (∼35 °C) when cooling agarose. This is the first systematic demonstration of enzymatic liquefaction of agarose, enabled by determining the sol-gel temperature of agarose under specific conditions and by characterizing the thermostability of an endo-type ß-agarase.


Asunto(s)
Glicósido Hidrolasas/metabolismo , Sefarosa/química , Sefarosa/metabolismo , Clonación Molecular , Estabilidad de Enzimas , Gammaproteobacteria/enzimología , Glicósido Hidrolasas/genética , Glicósido Hidrolasas/aislamiento & purificación , Cinética , Transición de Fase , Proteínas Recombinantes/metabolismo , Algas Marinas/química , Temperatura de Transición
14.
Appl Environ Microbiol ; 82(14): 4340-4349, 2016 07 15.
Artículo en Inglés | MEDLINE | ID: mdl-27208098

RESUMEN

UNLABELLED: In this study, we characterized Gly5M, originating from a marine bacterium, as a novel ß-1,3-1,6-endoglucanase in glycoside hydrolase family 5 (GH5) in the Carbohydrate-Active enZyme database. The gly5M gene encodes Gly5M, a newly characterized enzyme from GH5 subfamily 47 (GH5_47) in Saccharophagus degradans 2-40(T) The gly5M gene was cloned and overexpressed in Escherichia coli Through analysis of the enzymatic reaction products by thin-layer chromatography, high-performance liquid chromatography, and matrix-assisted laser desorption ionization-tandem time of flight mass spectrometry, Gly5M was identified as a novel ß-1,3-endoglucanase (EC 3.2.1.39) and bacterial ß-1,6-glucanase (EC 3.2.1.75) in GH5. The ß-1,3-endoglucanase and ß-1,6-endoglucanase activities were detected by using laminarin (a ß-1,3-glucan with ß-1,6-glycosidic linkages derived from brown macroalgae) and pustulan (a ß-1,6-glucan derived from fungal cell walls) as the substrates, respectively. This enzyme also showed transglycosylase activity toward ß-1,3-oligosaccharides when laminarioligosaccharides were used as the substrates. Since laminarin is the major form of glucan storage in brown macroalgae, Gly5M could be used to produce glucose and laminarioligosaccharides, using brown macroalgae, for industrial purposes. IMPORTANCE: In this study, we have discovered a novel ß-1,3-1,6-endoglucanase with a unique transglycosylase activity, namely, Gly5M, from a marine bacterium, Saccharophagus degradans 2-40(T) Gly5M was identified as the newly found ß-1,3-endoglucanase and bacterial ß-1,6-glucanase in GH5. Gly5M is capable of cleaving glycosidic linkages of both ß-1,3-glucans and ß-1,6-glucans. Gly5M also possesses a transglycosylase activity toward ß-1,3-oligosacchrides. Due to the broad specificity of Gly5M, this enzyme can be used to produce glucose or high-value ß-1,3- and/or ß-1,6-oligosaccharides.


Asunto(s)
Celulasa/genética , Celulasa/metabolismo , Gammaproteobacteria/enzimología , Cromatografía Líquida de Alta Presión , Cromatografía en Capa Delgada , Clonación Molecular , Escherichia coli/genética , Escherichia coli/metabolismo , Gammaproteobacteria/genética , Expresión Génica , Glucanos/metabolismo , Hidrólisis , Polisacáridos/metabolismo , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Especificidad por Sustrato
15.
Biotechnol Bioeng ; 113(11): 2443-52, 2016 11.
Artículo en Inglés | MEDLINE | ID: mdl-27217241

RESUMEN

2'-Fucosyllactose (2-FL) is one of the key oligosaccharides in human milk. In the present study, the salvage guanosine 5'-diphosphate (GDP)-l-fucose biosynthetic pathway from fucose was employed in engineered Escherichia coli BL21star(DE3) for efficient production of 2-FL. Introduction of the fkp gene coding for fucokinase/GDP-l-fucose pyrophosphorylase (Fkp) from Bacteroides fragilis and the fucT2 gene encoding α-1,2-fucosyltransferase from Helicobacter pylori allows the engineered E. coli to produce 2-FL from fucose, lactose and glycerol. To enhance the lactose flux to 2-FL production, the attenuated, and deleted mutants of ß-galactosidase were employed. Moreover, the 2-FL yield and productivity were further improved by deletion of the fucI-fucK gene cluster coding for fucose isomerase (FucI) and fuculose kinase (FucK). Finally, fed-batch fermentation of engineered E. coli BL21star(DE3) deleting lacZ and fucI-fucK, and expressing fkp and fucT2 resulted in 23.1 g/L of extracellular concentration of 2-FL and 0.39 g/L/h productivity. Biotechnol. Bioeng. 2016;113: 2443-2452. © 2016 Wiley Periodicals, Inc.


Asunto(s)
Escherichia coli/fisiología , Fucosiltransferasas/genética , Guanosina Difosfato Fucosa/metabolismo , Ingeniería Metabólica/métodos , Trisacáridos/biosíntesis , Fucosiltransferasas/metabolismo , Regulación Bacteriana de la Expresión Génica/fisiología , Guanosina Difosfato Fucosa/genética , Lactosa/metabolismo , Transducción de Señal/fisiología , Trisacáridos/genética
16.
Bioprocess Biosyst Eng ; 39(6): 959-66, 2016 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-26923145

RESUMEN

This study was performed to evaluate the effectiveness of acidic pretreatment in increasing the enzymatic digestibility of alginate from brown macroalgae. Pretreatment with 1 % (w/v) sulfuric acid at 120 °C for 30 min produced oligosaccharides, mannuronic acid, and guluronic acid. Enzymatic saccharification of pretreated alginate by alginate lyases produced 52.2 % of the theoretical maximal sugar yield, which was only 7.5 % higher than the sugar yield obtained with unpretreated alginate. Mass spectrometric analyses of products of the two reactions revealed that acidic pretreatment and enzymatic saccharification produced saturated monomers (i.e., mannuronic and guluronic acid) with saturated oligosaccharides and unsaturated monomers (i.e., 4-deoxy-L-erythro-5-hexoseulose uronic acid; DEH), respectively. While DEH is further metabolized by microorganisms, mannuronic acid and guluronic acid are not metabolizable. Because of the poor efficacy in increasing enzymatic digestibility and owing to the formation of non-fermentable saturated monomers, acidic pretreatment cannot be recommended for enzymatic saccharification and fermentation of alginate.


Asunto(s)
Alginatos/metabolismo , Metabolismo de los Hidratos de Carbono , Fermentación , Phaeophyceae/metabolismo , Algas Marinas/metabolismo , Cromatografía en Gel , Ácido Glucurónico/metabolismo , Ácidos Hexurónicos/metabolismo , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción
17.
Int J Mol Sci ; 17(4): 474, 2016 Mar 30.
Artículo en Inglés | MEDLINE | ID: mdl-27043539

RESUMEN

Thymoquinone (THQ) is a major component of black seeds. Given that both THQ and black seeds exhibit anti-cancer and anti-inflammatory activities, we hypothesized that THQ will affect cancer-associated thrombosis (CAT), which is primarily triggered by tissue factor (TF) and inflammation. The effect of both black seed-extracted and purchased ("pure") THQ on normal blood coagulation was tested with in vitro thromboelastography (TEG) and activated partial thromboplastin time (aPTT) coagulation assays. The effect of pure THQ on CAT was tested with aPTT assay using pancreatic cancer cell lines that are either positive or negative for TF, and with TEG assay using lipopolysaccharide as an inflammatory trigger. Additionally, the direct effect of THQ on the inactivation of factors IIa and Xa was assessed. Since TNF-α facilitates crosstalk between inflammation and thrombosis by triggering the NF-κB pathway, we tested THQ's ability to interfere with this communication with a luciferase assay. Both extracted and pure THQ had minimal effects on normal blood coagulation. Pure THQ reversed CAT initiated by both TF and inflammation to basal levels (p < 0.001). Mechanistically, while THQ had minimal to no effect on factor IIa and Xa inactivation, it strongly reduced the effects of TNF-α on NF-κB elements (p < 0.001). THQ has a minimal effect on basal coagulation and can reverse CAT in vitro, possibly by interfering with the crosstalk between inflammation and coagulation. This study suggests the utility of THQ as a preventative anticoagulant and/or as a supplement to existing chemotherapies and anticoagulant therapies.


Asunto(s)
Anticoagulantes/farmacología , Benzoquinonas/farmacología , Coagulación Sanguínea/efectos de los fármacos , Línea Celular Tumoral , Factor Xa/química , Factor Xa/metabolismo , Humanos , Inflamación/prevención & control , Lipopolisacáridos/toxicidad , FN-kappa B/metabolismo , Aceites Volátiles/química , Tiempo de Tromboplastina Parcial , Semillas/química , Semillas/metabolismo , Tromboelastografía , Tromboplastina/metabolismo , Trombosis/etiología , Trombosis/metabolismo , Factor de Necrosis Tumoral alfa/metabolismo
18.
Appl Environ Microbiol ; 80(19): 5965-73, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-25038102

RESUMEN

Marine red macroalgae have emerged to be renewable biomass for the production of chemicals and biofuels, because carbohydrates that form the major component of red macroalgae can be hydrolyzed into fermentable sugars. The main carbohydrate in red algae is agarose, and it is composed of D-galactose and 3,6-anhydro-L-galactose (AHG), which are alternately bonded by ß1-4 and α1-3 linkages. In this study, a novel ß-galactosidase that can act on agarooligosaccharides (AOSs) to release galactose was discovered in a marine bacterium (Vibrio sp. strain EJY3); the enzyme is annotated as Vibrio sp. EJY3 agarolytic ß-galactosidase (VejABG). Unlike the lacZ-encoded ß-galactosidase from Escherichia coli, VejABG does not hydrolyze common substrates like lactose and can act only on the galactose moiety at the nonreducing end of AOS. The optimum pH and temperature of VejABG on an agarotriose substrate were 7 and 35°C, respectively. Its catalytic efficiency with agarotriose was also similar to that with agaropentaose or agaroheptaose. Since agarotriose lingers as the unreacted residual oligomer in the currently available saccharification system using ß-agarases and acid prehydrolysis, the agarotriose-hydrolyzing capability of this novel ß-galactosidase offers an enormous advantage in the saccharification of agarose or agar in red macroalgae for its use as a biomass feedstock for fermentable sugar production.


Asunto(s)
Agar/metabolismo , Sefarosa/metabolismo , Vibrio/enzimología , beta-Galactosidasa/metabolismo , Agar/química , Secuencia de Aminoácidos , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Metabolismo de los Hidratos de Carbono , Carbohidratos/química , Clonación Molecular , Fermentación , Galactosa/química , Galactosa/metabolismo , Concentración de Iones de Hidrógeno , Hidrólisis , Oligosacáridos/química , Oligosacáridos/metabolismo , Filogenia , Rhodophyta/química , Especificidad por Sustrato , Temperatura , Vibrio/genética , beta-Galactosidasa/genética
19.
Mol Cell Proteomics ; 11(4): M111.010660, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22147732

RESUMEN

Most cell membrane proteins are known or predicted to be glycosylated in eukaryotic organisms, where surface glycans are essential in many biological processes including cell development and differentiation. Nonetheless, the glycosylation on cell membranes remains not well characterized because of the lack of sensitive analytical methods. This study introduces a technique for the rapid profiling and quantitation of N- and O-glycans on cell membranes using membrane enrichment and nanoflow liquid chromatography/mass spectrometry of native structures. Using this new method, the glycome analysis of cell membranes isolated from human embryonic stem cells and somatic cell lines was performed. Human embryonic stem cells were found to have high levels of high mannose glycans, which contrasts with IMR-90 fibroblasts and a human normal breast cell line, where complex glycans are by far the most abundant and high mannose glycans are minor components. O-Glycosylation affects relatively minor components of cell surfaces. To verify the quantitation and localization of glycans on the human embryonic stem cell membranes, flow cytometry and immunocytochemistry were performed. Proteomics analyses were also performed and confirmed enrichment of plasma membrane proteins with some contamination from endoplasmic reticulum and other membranes. These findings suggest that high mannose glycans are the major component of cell surface glycosylation with even terminal glucoses. High mannose glycans are not commonly presented on the surfaces of mammalian cells or in serum yet may play important roles in stem cell biology. The results also mean that distinguishing stem cells from other mammalian cells may be facilitated by the major difference in the glycosylation of the cell membrane. The deep structural analysis enabled by this new method will enable future mechanistic studies on the biological significance of high mannose glycans on stem cell membranes and provide a general tool to examine cell surface glycosylation.


Asunto(s)
Membrana Celular/metabolismo , Células Madre Embrionarias/metabolismo , Manosa/metabolismo , Polisacáridos/metabolismo , Línea Celular , Cromatografía Liquida , Fibroblastos/metabolismo , Glicosilación , Humanos , Proteómica , Espectrometría de Masas en Tándem
20.
Sci Rep ; 14(1): 4574, 2024 02 25.
Artículo en Inglés | MEDLINE | ID: mdl-38403792

RESUMEN

Administration of sedatives for post-resuscitation care can complicate the determination of the optimal timing to avoid inappropriate, pessimistic prognostications. This prospective study aimed to investigate the distribution and elimination kinetics of midazolam (MDZ) and its metabolites, and their association with awakening time. The concentrations of MDZ and its seven metabolites were measured immediately and at 4, 8, 12, and 24 h after the discontinuation of MDZ infusion, using liquid chromatography-tandem mass spectrometry. The area under the time-plasma concentration curve from 0 to 24 h after MDZ discontinuation (AUClast) was calculated based on the trapezoidal rule. Of the 15 enrolled patients, seven awakened after the discontinuation of MDZ infusion. MDZ and three of its metabolites were major compounds and their elimination kinetics followed a first-order elimination profile. In the multivariable analysis, only MDZ was associated with awakening time (AUClast: R2 = 0.59, p = 0.03; AUCinf: R2 = 0.96, p < 0.001). Specifically, a 0.001% increase in MDZ AUC was associated with a 1% increase in awakening time. In the individual regression analysis between MDZ concentration and awakening time, the mean MDZ concentration at awakening time was 16.8 ng/mL. The AUC of MDZ is the only significant factor associated with the awakening time.


Asunto(s)
Hipnóticos y Sedantes , Midazolam , Humanos , Estudios Prospectivos , Cromatografía Liquida
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