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1.
J Alzheimers Dis Rep ; 7(1): 51-76, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36777330

RESUMO

Background: Alzheimer's disease (AD) is a multifactorial disorder characterized by cognitive decline. Current available therapeutics for AD have limited clinical benefit. Therefore, preventive therapies for interrupting the development of AD are critically needed. Molecules targeting multifunction to interact with various pathlogical components have been considered to improve the therapeutic efficiency of AD. In particular, herbal medicines with multiplicity of actions produce cognitive benefits on AD. Bugu-M is a multi-herbal extract composed of Ganoderma lucidum (Antler form), Nelumbo nucifera Gaertn., Ziziphus jujuba Mill., and Dimocarpus longan, with the ability of its various components to confer resilience to cognitive deficits. Objective: To evaluate the potential of Bugu-M on amyloid-ß (Aß) toxicity and its in vitro mechanisms and on in vivo cognitive function. Methods: We illustrated the effect of Bugu-M on Aß25-35-evoked toxicity as well as its possible mechanisms to diminish the pathogenesis of AD in rat cortical neurons. For cognitive function studies, 2-month-old female 3×Tg-AD mice were administered 400 mg/kg Bugu-M for 30 days. Behavioral tests were performed to assess the efficacy of Bugu-M on cognitive impairment. Results: In primary cortical neuronal cultures, Bugu-M mitigated Aß-evoked toxicity by reducing cytoskeletal aberrations and axonal disruption, restoring presynaptic and postsynaptic protein expression, suppressing mitochondrial damage and apoptotic signaling, and reserving neurogenic and neurotrophic factors. Importantly, 30-day administration of Bugu-M effectively prevented development of cognitive impairment in 3-month-old female 3×Tg-AD mice. Conclusion: Bugu-M might be beneficial in delaying the progression of AD, and thus warrants consideration for its preventive potential for AD.

2.
Cells ; 11(14)2022 07 11.
Artigo em Inglês | MEDLINE | ID: mdl-35883615

RESUMO

n-butylidenephthalide (BP) has been verified as having the superior characteristic of cancer cell toxicity. Furthermore, gold (Au) nanoparticles are biocompatible materials, as well as effective carriers for delivering bio-active molecules for cancer therapeutics. In the present research, Au nanoparticles were first conjugated with polyethylene glycol (PEG), and then cross-linked with BP to obtain PEG-Au-BP nanodrugs. The physicochemical properties were characterized through ultraviolet-visible spectroscopy (UV-Vis), Fourier-transform infrared spectroscopy (FTIR), and dynamic light scattering (DLS) to confirm the combination of PEG, Au, and BP. In addition, both the size and structure of Au nanoparticles were observed through scanning electron microscopy (SEM) and transmission electron microscopy (TEM), where the size of Au corresponded to the results of DLS assay. Through in vitro assessments, non-transformed BAEC and DBTRG human glioma cells were treated with PEG-Au-BP drugs to investigate the tumor-cell selective cytotoxicity, cell uptake efficiency, and mechanism of endocytic routes. According to the results of MTT assay, PEG-Au-BP was able to significantly inhibit DBTRG brain cancer cell proliferation. Additionally, cell uptake efficiency and potential cellular transportation in both BAEC and DBTRG cell lines were observed to be significantly higher at 2 and 24 h. Moreover, the mechanisms of endocytosis, clathrin-mediated endocytosis, and cell autophagy were explored and determined to be favorable routes for BAEC and DBTRG cells to absorb PEG-Au-BP nanodrugs. Next, the cell progression and apoptosis of DBTRG cells after PEG-Au-BP treatment was investigated by flow cytometry. The results show that PEG-Au-BP could remarkably regulate the DBTRG cell cycle at the Sub-G1 phase, as well as induce more apoptotic cells. The expression of apoptotic-related proteins in DBTRG cells was determined through Western blotting assay. After treatment with PEG-Au-BP, the apoptotic cascade proteins p21, Bax, and Act-caspase-3 were all significantly expressed in DBTRG brain cancer cells. Through in vivo assessments, the tissue morphology and particle distribution in a mouse model were examined after a retro-orbital sinus injection containing PEG-Au-BP nanodrugs. The results demonstrate tissue integrity in the brain (forebrain, cerebellum, and midbrain), heart, liver, spleen, lung, and kidney, as they did not show significant destruction due to PEG-Au-BP treatment. Simultaneously, the extended retention period for PEG-Au-BP nanodrugs was discovered, particularly in brain tissue. The above findings identify PEG-Au-BP as a potential nanodrug for brain cancer therapies.


Assuntos
Neoplasias Encefálicas , Nanopartículas Metálicas , Animais , Proteínas Reguladoras de Apoptose/uso terapêutico , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/patologia , Linhagem Celular Tumoral , Ouro/química , Ouro/farmacologia , Humanos , Nanopartículas Metálicas/química , Camundongos , Anidridos Ftálicos , Polietilenoglicóis/química
3.
Cells ; 11(12)2022 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-35740991

RESUMO

Chitosan (Chi) is a natural polymer that has been demonstrated to have potential as a promoter of neural regeneration. In this study, Chi was prepared with various amounts (25, 50, and 100 ppm) of gold (Au) nanoparticles for use in in vitro and in vivo assessments. Each as-prepared material was first characterized by UV-visible spectroscopy (UV-Vis), Fourier-transform infrared spectroscopy (FTIR), atomic force microscopy (AFM), scanning electron microscopy (SEM), and Dynamic Light Scattering (DLS). Through the in vitro experiments, Chi combined with 50 ppm of Au nanoparticles demonstrated better biocompatibility. The platelet activation, monocyte conversion, and intracellular ROS generation was remarkably decreased by Chi-Au 50 pm treatment. Furthermore, Chi-Au 50 ppm could facilitate colony formation and strengthen matrix metalloproteinase (MMP) activation in mesenchymal stem cells (MSCs). The lower expression of CD44 in Chi-Au 50 ppm treatment demonstrated that the nanocomposites could enhance the MSCs undergoing differentiation. Chi-Au 50 ppm was discovered to significantly induce the expression of GFAP, ß-Tubulin, and nestin protein in MSCs for neural differentiation, which was verified by real-time PCR analysis and immunostaining assays. Additionally, a rat model involving subcutaneous implantation was used to evaluate the superior anti-inflammatory and endothelialization abilities of a Chi-Au 50 ppm treatment. Capsule formation and collagen deposition were decreased. The CD86 expression (M1 macrophage polarization) and leukocyte filtration (CD45) were remarkably reduced as well. In summary, a Chi polymer combined with 50 ppm of Au nanoparticles was proven to enhance the neural differentiation of MSCs and showed potential as a biosafe nanomaterial for neural tissue engineering.


Assuntos
Quitosana , Células-Tronco Mesenquimais , Nanopartículas Metálicas , Nanocompostos , Animais , Quitosana/química , Quitosana/farmacologia , Ouro/química , Ouro/farmacologia , Nanopartículas Metálicas/química , Nanocompostos/química , Ratos
4.
Nat Commun ; 13(1): 2518, 2022 05 06.
Artigo em Inglês | MEDLINE | ID: mdl-35523813

RESUMO

The nervous and endocrine systems coordinate with each other to closely influence physiological and behavioural responses in animals. Here we show that WAKE (encoded by wide awake, also known as wake) modulates membrane levels of GABAA receptor Resistance to Dieldrin (Rdl), in insulin-producing cells of adult male Drosophila melanogaster. This results in changes to secretion of insulin-like peptides which is associated with changes in juvenile hormone biosynthesis in the corpus allatum, which in turn leads to a decrease in 20-hydroxyecdysone levels. A reduction in ecdysone signalling changes neural architecture and lowers the perception of the male-specific sex pheromone 11-cis-vaccenyl acetate by odorant receptor 67d olfactory neurons. These finding explain why WAKE-deficient in Drosophila elicits significant male-male courtship behaviour.


Assuntos
Proteínas de Drosophila , Insulinas , Acetatos , Animais , Corte , Drosophila/metabolismo , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/metabolismo , Sistema Endócrino/metabolismo , Masculino , Percepção , Feromônios , Receptores de GABA-A , Comportamento Sexual Animal/fisiologia
5.
J Formos Med Assoc ; 121(9): 1773-1785, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35094911

RESUMO

BACKGROUND/PURPOSE: The increasing prevalence of overweight and obese children and adolescents has been recognized as a public health threat worldwide. This study aimed to assess the effect of a stepwise lifestyle intervention in children and adolescents. METHODS: We developed a multidisciplinary clinic aimed at providing lifestyle interventions for obese children and adolescents. The program comprised three stages with stepwise goals: knowledge building (the first 4 weeks), habit consolidation (5-12 weeks), and self-monitoring (13-20 weeks). RESULTS: Of the 63 participants (age 11.6 ± 3.2 years) who entered the first stage of the program, 48, 22, and 15 completed the first, second and third stages (4, 12, and 20 weeks), respectively. In the first stage, significant improvement was noted in body weight, body mass index (BMI), BMI z-score, and waist circumference. Improvements in physical fitness performance were observed at 4 weeks in 3/5 items and at 12 weeks in 4/5 items. The decreases in body weight, BMI and BMI z-score were most prominent in the first two stages. In the third stage, participants maintained a stable body weight. In the 15 subjects who completed the whole program, BMI decreased from 29.3 ± 6.9 to 27.8 ± 6.1 (P = 0.001), and BMI z-score decreased from 3.06 ± 0.96 to 2.69 ± 0.91(P = 0.001). CONCLUSION: We developed a feasible multidisciplinary program based on knowledge education and individualized training. BMI and physical fitness scores can be used as early indicators of lifestyle change for obese children and adolescents.


Assuntos
Sobrepeso , Obesidade Infantil , Adolescente , Índice de Massa Corporal , Peso Corporal , Criança , Humanos , Estilo de Vida
6.
Dev Cell ; 56(13): 1976-1988.e4, 2021 07 12.
Artigo em Inglês | MEDLINE | ID: mdl-34146466

RESUMO

Ploidy variation is a cancer hallmark and is frequently associated with poor prognosis in high-grade cancers. Using a Drosophila solid-tumor model where oncogenic Notch drives tumorigenesis in a transition-zone microenvironment in the salivary gland imaginal ring, we find that the tumor-initiating cells normally undergo endoreplication to become polyploid. Upregulation of Notch signaling, however, induces these polyploid transition-zone cells to re-enter mitosis and undergo tumorigenesis. Growth and progression of the transition-zone tumor are fueled by a combination of polyploid mitosis, endoreplication, and depolyploidization. Both polyploid mitosis and depolyploidization are error prone, resulting in chromosomal copy-number variation and polyaneuploidy. Comparative RNA-seq and epistasis analysis reveal that the DNA-damage response genes, also active during meiosis, are upregulated in these tumors and are required for the ploidy-reduction division. Together, these findings suggest that polyploidy and associated cell-cycle variants are critical for increased tumor-cell heterogeneity and genome instability during cancer progression.


Assuntos
Carcinogênese/genética , Instabilidade Genômica/genética , Neoplasias/genética , Poliploidia , Animais , Ciclo Celular/genética , Drosophila melanogaster/genética , Epistasia Genética/genética , Dosagem de Genes/genética , Heterogeneidade Genética , Humanos , Meiose/genética , Mitose/genética , Neoplasias/patologia , Ploidias , RNA-Seq , Receptores Notch/genética , Transdução de Sinais
7.
FASEB J ; 35(5): e21614, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33908669

RESUMO

Alexander disease (AxD) caused by mutations in the coding region of GFAP is a neurodegenerative disease characterized by astrocyte dysfunction, GFAP aggregation, and Rosenthal fiber accumulation. Although how GFAP mutations cause disease is not fully understood, Rosenthal fibers could be induced by forced overexpression of human GFAP and this could be lethal in mice implicate that an increase in GFAP levels is central to AxD pathogenesis. Our recent studies demonstrated that intronic GFAP mutations cause disease by altering GFAP splicing, suggesting that an increase in GFAP isoform expression could lead to protein aggregation and astrocyte dysfunction that typify AxD. Here we test this hypothesis by establishing primary astrocyte cultures from transgenic mice overexpressing human GFAP. We found that GFAP-δ and GFAP-κ were disproportionately increased in transgenic astrocytes and both were enriched in Rosenthal fibers of human AxD brains. In vitro assembly studies showed that while the major isoform GFAP-α self-assembled into typical 10-nm filaments, minor isoforms including GFAP-δ, -κ, and -λ were assembly-compromised and aggregation prone. Lentiviral transduction showed that expression of these minor GFAP isoforms decreased filament solubility and increased GFAP stability, leading to the formation of Rosenthal fibers-like aggregates that also disrupted the endogenous intermediate filament networks. The aggregate-bearing astrocytes lost their normal morphology and glutamate buffering capacity, which had a toxic effect on neighboring neurons. In conclusion, our findings provide evidence that links elevated GFAP isoform expression with GFAP aggregation and impaired glutamate transport, and suggest a potential non-cell-autonomous mechanism underlying neurodegeneration through astrocyte dysfunction.


Assuntos
Doença de Alexander/patologia , Astrócitos/patologia , Proteína Glial Fibrilar Ácida/química , Proteína Glial Fibrilar Ácida/metabolismo , Ácido Glutâmico/metabolismo , Mutação , Agregados Proteicos , Doença de Alexander/metabolismo , Animais , Astrócitos/metabolismo , Humanos , Camundongos , Camundongos Transgênicos , Conformação Proteica , Isoformas de Proteínas
8.
Dev Biol ; 475: 10-20, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33662357

RESUMO

microRNAs (miRNAs) are ~21-22 nucleotide (nt) RNAs that mediate broad post-transcriptional regulatory networks. However, genetic analyses have shown that the phenotypic consequences of deleting individual miRNAs are generally far less overt compared to their misexpression. This suggests that miRNA deregulation may have broader phenotypic impacts during disease situations. We explored this concept in the Drosophila eye, by screening for miRNAs whose misexpression could modify the activity of pro-apoptotic factors. Via unbiased and comprehensive in vivo phenotypic assays, we identify an unexpectedly large set of miRNA hits that can suppress the action of pro-apoptotic genes hid and grim. We utilize secondary assays to validate that a subset of these miRNAs can inhibit irradiation-induced cell death. Since cancer cells might seek to evade apoptosis pathways, we modeled this situation by asking whether activation of anti-apoptotic miRNAs could serve as "second hits". Indeed, while clones of the lethal giant larvae (lgl) tumor suppressor are normally eliminated during larval development, we find that diverse anti-apoptotic miRNAs mediate the survival of lgl mutant clones in third instar larvae. Notably, while certain anti-apoptotic miRNAs can target apoptotic factors, most of our screen hits lack obvious targets in the core apoptosis machinery. These data highlight how a genetic approach can reveal distinct and powerful activities of miRNAs in vivo, including unexpected functional synergies during disease or cancer-relevant settings.


Assuntos
Apoptose/genética , MicroRNAs/genética , Animais , Apoptose/fisiologia , Morte Celular/genética , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/metabolismo , Olho/metabolismo , Proteínas do Olho/genética , Proteínas do Olho/metabolismo , Expressão Gênica/genética , Perfilação da Expressão Gênica/métodos , Regulação da Expressão Gênica/genética , Regulação da Expressão Gênica/fisiologia , Redes Reguladoras de Genes/genética , MicroRNAs/fisiologia , Neuropeptídeos/genética , Neuropeptídeos/metabolismo , Fenótipo , Proteínas Supressoras de Tumor/genética , Proteínas Supressoras de Tumor/metabolismo
9.
J Vis Exp ; (168)2021 02 02.
Artigo em Inglês | MEDLINE | ID: mdl-33616117

RESUMO

This protocol describes the allotransplantation of tumors in Drosophila melanogaster using an auto-nanoliter injection apparatus. With the use of an autoinjector apparatus, trained operators can achieve more efficient and consistent transplantation results compared to those obtained using a manual injector. Here, we cover topics in a chronological fashion: from the crossing of Drosophila lines, to the induction and dissection of the primary tumor, transplantation of the primary tumor into a new adult host and continued generational transplantation of the tumor for extended studies. As a demonstration, here we use Notch intracellular domain (NICD) overexpression induced salivary gland imaginal ring tumors for generational transplantation. These tumors can first be reliably induced in a transition-zone microenvironment within larval salivary gland imaginal rings, then allografted and cultured in vivo to study continued tumor growth, evolution, and metastasis. This allotransplantation method can be useful in potential drug screening programs, as well as for studying tumor-host interactions.


Assuntos
Aloenxertos/transplante , Drosophila melanogaster/fisiologia , Nanotecnologia/instrumentação , Transplante de Neoplasias , Neoplasias/patologia , Abdome/patologia , Animais , Dissecação , Injeções , Glândulas Salivares/patologia , Microambiente Tumoral
10.
Oxid Med Cell Longev ; 2020: 7353618, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32047579

RESUMO

Cisplatin chemotherapy causes myelosuppression and often limits treatment duration and dose escalation in patients. Novel approaches to circumvent or lessen myelotoxicity may improve clinical outcome and quality of life in these patients. Chlorella sorokiniana (CS) is a freshwater unicellular green alga and exhibits encouraging efficacy in immunomodulation and anticancer in preclinical studies. However, the efficacy of CS on chemoprotection remains unclear. We report here, for the first time, that CS extract (CSE) could protect normal myeloid cells and PBMCs from cisplatin toxicity. Also, cisplatin-induced apoptosis in HL-60 cells was rescued through reservation of mitochondrial function, inhibition of cytochrome c release to cytosol, and suppression of caspase and PARP activation. Intriguingly, cotreatment of CSE attenuated cisplatin-evoked hypocellularity of bone marrow in mice. Furthermore, we observed the enhancement of CSF-GM activity in bone marrow and spleen in mice administered CSE and cisplatin, along with increased CD11b levels in spleen. In conclusion, we uncovered a novel mechanism of CSE on myeloprotection, whereby potentially supports the use of CSE as a chemoprotector against cisplatin-induced bone marrow toxicity. Further clinical investigation of CSE in combination with cisplatin is warranted.


Assuntos
Antineoplásicos/efeitos adversos , Células da Medula Óssea/efeitos dos fármacos , Cisplatino/efeitos adversos , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/tratamento farmacológico , Mitocôndrias/metabolismo , Células Mieloides/efeitos dos fármacos , Extratos Vegetais/uso terapêutico , Células da Medula Óssea/patologia , Antígeno CD11b/metabolismo , Chlorella , Cisplatino/uso terapêutico , Fator Estimulador de Colônias de Granulócitos e Macrófagos/metabolismo , Células HL-60 , Humanos , Imunomodulação , Terapia de Imunossupressão , Células Mieloides/patologia
11.
J Food Prot ; 83(6): 975-983, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-32034398

RESUMO

ABSTRACT: Flax seed has become an increasingly popular food ingredient because of its nutrient richness as well as potential health benefits. Flax seeds are often ground before consumption, and flax seed cakes are used as animal feed. Aflatoxin production may occur subsequently when the ground seeds are stored in an environment that supports fungal growth. The objectives of this study were to determine the growth of two toxigenic fungi, Aspergillus flavus and A. parasiticus, and to quantify the concentrations of four major aflatoxins (AFB1, AFG1, AGB2, and AFG2) produced by the two fungi on ground flax seeds with water activities (aws) of 0.82, 0.86, 0.90, 0.94, and 0.98, incubated for 30 days at 20, 27, and 35°C. Results of the study showed that A. flavus was able to grow on ground seeds with aw from 0.86 to 0.98 at all three temperatures, and the most rapid growth occurred at aws 0.90 and 0.94 at 27°C. In comparison, A. parasiticus grew on seeds with aw from 0.86 to 0.98 at 27 and 35°C as well as on seeds with aw from 0.86 to 0.90 at 20°C, and the most favorable growth condition was aw from 0.90 to 0.94 at 35°C. A. flavus produced aflatoxins on seeds with aw from 0.90 to 0.94 at 27°C as well as on seeds with aw from 0.86 to 0.98 at 35°C, and the maximum total aflatoxin (298 µg/kg), AFB1 (247 µg/kg), and AFG1 (51 µg/kg) were found on seeds with aw 0.90 at 35°C. In comparison, A. parasiticus produced aflatoxins under a wider range of conditions, which included aw 0.86 at 27 and 35°C, aw 0.90 at 20 and 27°C, aw 0.94 at 27°C, and aw 0.98 at 35°C. The maximum total aflatoxin (364 µg/kg) and maximum AFB1 (324 µg/kg) along with 34 µg/kg AFG1 and 6 µg/kg AFB2 were produced by A. parasiticus on seeds with aw 0.98 incubated at 35°C for 30 days. Linear regression models also indicated that high incubation temperature (35°C) was optimal for overall fungal growth and for formation of high levels of aflatoxin by both fungi. Future studies should also address aflatoxin contamination in flax seed oil.


Assuntos
Aflatoxinas , Linho , Aflatoxina B1 , Aflatoxinas/análise , Animais , Aspergillus , Aspergillus flavus , Sementes/química
12.
J Chem Phys ; 151(8): 084302, 2019 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-31470727

RESUMO

A suppressed-Doppler (Δν = 180 MHz) infrared spectrum of monodeuterated ammonium ions (NH3D+) has been obtained for the ν1 (symmetric) and ν4 (degenerate) N-H stretch bands via direct absorption high resolution IR laser spectroscopy in a planar slit jet discharge expansion. The ion is efficiently generated by H3 + protonation of NH2D in a discharge mixture of H2/NH2D, with the resulting expansion rapidly cooling the molecular ions into low rotational states. The first high-resolution infrared spectrum of ν1 is reported, as well as many previously unobserved transitions in the ν4 rovibrational manifold. Simultaneous observation of both ν1 and ν4 permits elucidation of both the vibrational ground and excited state properties of the ion, including rigorous benchmarking of band origins against high-level anharmonic ab initio theory as well as determination of the ν1:ν4 intensity ratio for comparison with bond-dipole model predictions. Ground-state combination differences from this work and earlier studies permit the rotational constants of NH3D+ to be determined to unprecedented accuracy, the results of which support previous laboratory and astronomical assignment of the 10-00 pure rotational transition and should aid future searches for other rotational transitions as well.

13.
Int J Food Microbiol ; 296: 8-13, 2019 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-30825812

RESUMO

Nyjer oil seed cake supports high levels of aflatoxin B1 (AFB1) production. AFB1 is a secondary metabolite of Aspergillus flavus and A. parasiticus, classified as a Class 1A carcinogen. The aim of this study was to determine the effects of temperature (20, 27, and 35 °C) and water activity (0.82, 0.86, 0.90, 0.94, and 0.98 aw) on fungal growth and AFB1 production of A. flavus and A. parasiticus on ground Nyjer seeds over a 30-day incubation period. Linear regression models indicated that both fungal growth and AFB1 production were significantly influenced by water activity of Nyjer seeds and incubation temperature. The two fungi did not grow on Nyjer seeds at 0.82 aw at the three incubation temperatures. The most favorable growth conditions for both fungi were 0.90-0.98 aw at 27 °C or 0.90-0.94 aw at 35 °C. The optimum temperature for AFB1 production was 27 °C for both A. flavus and A. parasiticus (with regression coefficients of 6.01 and 9.11, respectively). Both fungi were likely to produce high levels of AFB1 at 0.90 aw (with regression coefficients of 3.56 for A. flavus and 7.17 for A. parasiticus). Aspergillus flavus only produced AFB1 on seeds with 0.90-0.98 aw at 27 °C (in the range of 203-282 µg/kg) and on seeds with 0.90 aw at 35 °C (212 µg/kg). No detectable AFB1 was produced by this fungus in any other culture conditions that were studied. Aspergillus parasiticus, in contrast, was able to produce AFB1 under all of the growth conditions. At 20 °C, this fungus produced the highest level of AFB1 (212 µg/kg) at high water activity (0.98 aw). At 27 °C, A. parasiticus produced high levels of AFB1 (in the range of 209-265 µg/kg) at a wide range of water activities (0.86-0.98 aw). In the entire study, the highest AFB1 concertation for A. parasiticus was detected on seeds incubated at high temperature (35 °C) and low water activity (0.86 aw). The findings of this study could help optimize the storage conditions of Nyjer oil seeds to reduce aflatoxin contamination.


Assuntos
Aflatoxina B1/biossíntese , Aspergillus flavus/crescimento & desenvolvimento , Aspergillus flavus/metabolismo , Asteraceae/microbiologia , Sementes/microbiologia , Temperatura Alta , Água/análise
14.
J Chem Phys ; 149(14): 144303, 2018 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-30316288

RESUMO

High-resolution rotationally resolved spectra of the N-H stretch vibrational mode (ν 1) of jet-cooled ND3H+ ions are collected and analyzed in a sub-Doppler slit-jet infrared spectrometer. The isotopomeric ammonium ions are generated by proton transfer from H3 + to ND3 in a discharge of an ND3/H2 gas mixture, whereby the slit jet expansion cools the nascent ND3H+ ions into lower rotational states. Rotational assignments are confirmed by four-line combination differences that agree to within the spectrometer precision (9 MHz). Based on precision two-line ground-state combination differences and a symmetric top Hamiltonian, the B, D J , and D JK rotational constants for the ground vibrational state of ND3H+ are determined with high precision for the first time. Approximate rotational constants for the ν 1 excited state are also determined, with a band origin at 3316.8425(19) cm-1 and in remarkable (∼0.1 cm-1) agreement with high level anharmonic theoretical predictions by Guo and co-workers [J. Phys. Chem. A, 120, 2185 (2016)]. Our results allow us to predict several low-J pure rotational transitions of ND3H+, which we hope will support future studies of this important ion in laboratory and astronomical rotational spectroscopy.

15.
J Chem Phys ; 148(1): 014304, 2018 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-29306286

RESUMO

Sub-Doppler infrared rovibrational transitions in the symmetric (v1) and antisymmetric (v6) NH stretch modes of the isotopomerically substituted ND2H2+ ammonium cation are reported for the first time in a slit jet discharge supersonic expansion spectrometer. The partially H/D substituted cation is generated by selective isotopic exchange of ND3 with H2O to form NHD2, followed by protonation with H3+ formed in the NHD2/H2/Ne slit-jet discharge expansion environment. Rotational assignment for ND2H2+ is confirmed rigorously by four line ground state combination differences, which agree to be within the sub-Doppler precision in the slit jet (∼9 MHz). Observation of both b-type (ν1) and c-type (ν6) bands enables high precision determination of the ground and vibrationally excited state rotational constants. From an asymmetric top Watson Hamiltonian analysis, the ground state constants are found to be A″ = 4.856 75(4) cm-1, B″ = 3.968 29(4) cm-1, and C″ = 3.446 67(6) cm-1, with band origins at 3297.5440(1) and 3337.9050(1) cm-1 for the v1 and v6 modes, respectively. This work permits prediction of precision microwave/mm-wave transitions, which should be invaluable in facilitating ongoing spectroscopic searches for partially deuterated ammonium cations in interstellar clouds and star-forming regions of the interstellar medium.

16.
Oxid Med Cell Longev ; 2017: 5414297, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29181126

RESUMO

Neuroinflammation plays a central role in the pathophysiology of Alzheimer's disease (AD). Compounds that suppress neuroinflammation have been identified as potential therapeutic targets for AD. Rhinacanthin C (RC), a naphthoquinone ester found in Rhinacanthus nasutus Kurz (Acanthaceae), is currently proposed as an effective molecule against inflammation. However, the exact role of RC on neuroinflammation remains to be elucidated. In the present study, we investigated RC effect on modulating lipopolysaccharides (LPS), amyloid-ß peptide (Aß), or interferon-γ- (IFN-γ-) evoked pathological events in neurons and glia. Our findings demonstrated that RC prevented Aß-induced toxicity in rat hippocampal neurons and attenuated LPS-activated nitric oxide (NO) production, inducible nitric oxide synthase (iNOS) expression, and NF-κB signaling in rat glia. Likewise, RC suppressed LPS-induced neuroinflammation by reducing NO production and iNOS, IL-1ß, CCL-2, and CCL-5 mRNA levels in rat microglia. Further studies using BV-2 microglia revealed that RC inhibited LPS-, Aß-, and IFN-γ-stimulated IL-6 and TNF-α secretion. Of note, NF-κB and ERK activation was abrogated by RC in BV-2 cell response to Aß or IFN-γ. Moreover, RC protected neurons from Aß-stimulated microglial conditioned media-dependent toxicity. Collectively, these data highlight the beneficial effects of RC on neuroprotection and support the therapeutic implications of RC to neuroinflammation-mediated conditions.


Assuntos
Peptídeos beta-Amiloides/metabolismo , Inflamação/tratamento farmacológico , Lipopolissacarídeos/metabolismo , Naftoquinonas/uso terapêutico , Neurônios/metabolismo , Animais , Interferon gama/metabolismo , Camundongos , Naftoquinonas/farmacologia , Neuroglia/metabolismo , Ratos , Ratos Sprague-Dawley
17.
J Chem Phys ; 146(19): 194307, 2017 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-28527463

RESUMO

The sub-Doppler CH-symmetric stretch (ν3) infrared absorption spectrum of a hydroxymethyl (CH2OH) radical is observed and analyzed with the radical formed in a slit-jet supersonic discharge expansion (Trot = 18 K) via Cl atom mediated H atom abstraction from methanol. The high sensitivity of the spectrometer and reduced spectral congestion associated with the cooled expansion enable first infrared spectroscopic observation of hydroxymethyl transitions from both ± symmetry tunneling states resulting from large amplitude COH torsional motion. Nuclear spin statistics due to exchange of the two methyl H-atoms aid in unambiguous rovibrational assignment of two A-type Ka = 0 ← 0 and Ka = 1 ← 1 bands out of each ± tunneling state, with additional spectral information obtained from spin-rotation splittings in P, Q, and R branch Ka = 1 ← 1 transitions that become resolved at low N. A high level ab initio potential surface (CCSD(T)-f12b/cc-pvnzf12 (n = 2,3)/CBS) is calculated in the large amplitude COH torsional and CH2 wag coordinates, which in the adiabatic approximation and with zero point correction predicts ground state tunneling splittings in good qualitative agreement with experiment. Of particular astrochemical interest, a combined fit of the present infrared ground state combination differences with recently reported millimeter-wave frequencies permits the determination of improved accuracy rotational constants for the ground vibrational state, which will facilitate ongoing millimeter/microwave searches for a hydroxymethyl radical in the interstellar medium.

18.
ACS Appl Mater Interfaces ; 9(15): 13092-13101, 2017 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-28353331

RESUMO

Studying cellular crosstalk is important for understanding tumor initiation, progression, metastasis, and therapeutic resistance. Moreover, a three-dimensional (3D) cell culture model can provide a more physiologically meaningful culture microenvironment. However, studying cellular crosstalk in a 3D cell culture model involves tedious processing. In this study, a paper/poly(methyl methacrylate) (PMMA) hybrid 3D cell culture microfluidic platform was successfully developed for the study of cellular crosstalk. The platform was a paper substrate with culture microreactors placed on a PMMA substrate with hydrogel-infused channels. Different types of cells were directly seeded and cultured in the microreactors. Aberrant cell proliferation of the affected cells was induced by secretions from transfected cells, and the proliferation ratios were investigated using a colorimetric method. The results showed that the responses of cellular crosstalk were different in different types of cells. Moreover, neutralizing and competitive assays were performed to show the functionality of the platform. Additionally, the triggered signaling pathways of the affected cells were directly analyzed by a subsequent immunoassay. The microfluidic platform provides a simple method for studying cellular crosstalk and the corresponding signaling pathways in a 3D culture model.


Assuntos
Técnicas de Cultura de Células , Proliferação de Células , Células Híbridas , Técnicas Analíticas Microfluídicas , Microfluídica , Polimetil Metacrilato
19.
Biomed Microdevices ; 19(1): 13, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-28229307

RESUMO

Periosteum-derived cells was indicated to respond to mechanical force and have stem cell potential capable of differentiating into multiple tissue. Investigation of osteogenic activity under mechanical stimulation is important to understand the therapeutic conditions of fracture healing. In this work, a cell culture platform was developed for respectively providing isotropic and anisotropic axial strain. Primary rabbit periosteal cells were isolated and cultured in the chamber. Multi-axial tensile strain was received and osteogenic activity was investigated by mRNA expressions of CBFA1 and OPN. The highest mRNA expression was found in moderate strain (5-8%) under anisotropic axial strain. These results provided important foundation for further in vivo studies and development of tailor-made stretching rehabilitation equipment.


Assuntos
Técnicas de Cultura de Células/instrumentação , Osteogênese , Periósteo/citologia , Estresse Mecânico , Resistência à Tração , Animais , Subunidade alfa 1 de Fator de Ligação ao Core/genética , Periósteo/metabolismo , Pressão , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Coelhos
20.
J Chem Phys ; 145(4): 044304, 2016 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-27475358

RESUMO

A series of CH stretch modes in phenyl radical (C6H5) has been investigated via high resolution infrared spectroscopy at sub-Doppler resolution (∼60 MHz) in a supersonic discharge slit jet expansion. Two fundamental vibrations of a1 symmetry, ν1 and ν2, are observed and rotationally analyzed for the first time, corresponding to in-phase and out-of-phase symmetric CH stretch excitation at the ortho/meta/para and ortho/para C atoms with respect to the radical center. The ν1 and ν2 band origins are determined to be 3073.968 50(8) cm(-1) and 3062.264 80(7) cm(-1), respectively, which both agree within 5 cm(-1) with theoretical anharmonic scaling predictions based on density functional B3LYP/6-311g++(3df,3dp) calculations. Integrated band strengths for each of the CH stretch bands are analyzed, with the relative intensities agreeing remarkably well with theoretical predictions. Frequency comparison with previous low resolution Ar-matrix spectroscopy [A. V. Friderichsen et al., J. Am. Chem. Soc. 123, 1977 (2001)] reveals a nearly uniform Δν ≈ + 10-12 cm(-1) blue shift between gas phase and Ar matrix values for ν1 and ν2. This differs substantially from the much smaller red shift (Δν ≈ - 1 cm(-1)) reported for the ν19 mode, and suggests a simple physical model in terms of vibrational mode symmetry and crowding due to the matrix environment. Finally, the infrared phenyl spectra are well described by a simple asymmetric rigid rotor Hamiltonian and show no evidence for spectral congestion due to intramolecular vibrational coupling, which bodes well for high resolution studies of other ring radicals and polycyclic aromatic hydrocarbons. In summary, the combination of slit jet discharge methods with high resolution infrared lasers enables spectroscopic investigation of even highly reactive combustion and interstellar radical intermediates under gas phase, jet-cooled (Trot ≈ 11 K) conditions.

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