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1.
J Org Chem ; 87(16): 11196-11203, 2022 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-35912586

RESUMO

The development of a visible light-mediated synthetic method for chiral 1,2-amino tertiary alcohols is described. In the presence of a chiral oxazaborolidinium ion catalyst and photosensitizer, the enantioselective addition of an α-aminoalkyl radical to aryl methyl ketones under visible light provides chiral 1,2-amino tertiary alcohol derivatives in high yields (up to 88%) with excellent enantioselectivities (up to 98% ee). With mechanistic studies such as radical trapping analysis, radical clock analysis, and the measurement of quantum yield, a plausible catalytic cycle is proposed.

2.
Insights Imaging ; 13(1): 80, 2022 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-35467253

RESUMO

Endometrial carcinoma is the most common gynaecological cancer in developed countries. Most cases are low-volume/low-grade tumour at presentation; however, high-grade subtypes may present with locally advanced disease with higher propensity for spread outside of the pelvis. MRI has a role in local staging of the tumour and helping the clinicians in treatment decision making. This pictorial essay gives examples of endometrial carcinoma at different stages with histological correlation. It also explores the potential limitations and pitfalls of imaging in this context.

3.
Nutrients ; 14(5)2022 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-35268079

RESUMO

Dendropanax trifidus (DT) is a medicinal herb native to East Asia, which has been used extensively for its therapeutic properties in traditional medicine. In this study, we examined the effects of DT sap on the regulation of body weight and muscle metabolism in mice. Obese model db/db mice were administered daily with DT sap or vehicle control over a 6-week period. The effects of DT sap on muscle metabolism were studied in C2C12 muscle cells, where glycolytic and mitochondrial respiration rates were monitored. As AMP-activated protein kinase (AMPK) is a master regulator of metabolism and plays an important function as an energy sensor in muscle tissue, signaling pathways related with AMPK were also examined. We found that DT sap inhibited body weight increase in db/db, db/+, and +/+ mice over a 6-week period, while DT sap-treated muscle cells showed increased muscle metabolism and also increased phosphorylation of AMPK and Acetyl-CoA Carboxylase (ACC). Finally, we found that DT sap, which is enriched in estrogen in our previous study, significantly activates estrogen alpha receptor in a concentration-dependent manner, which can drive the activation of AMPK signaling and may be related to the muscle metabolism and weight changes observed here.


Assuntos
Proteínas Quinases Ativadas por AMP , Acetil-CoA Carboxilase , Proteínas Quinases Ativadas por AMP/metabolismo , Acetil-CoA Carboxilase/metabolismo , Animais , Peso Corporal , Receptor alfa de Estrogênio , Camundongos , Camundongos Obesos , Células Musculares/metabolismo
4.
Org Lett ; 23(4): 1516-1520, 2021 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-33555190

RESUMO

A catalytic enantioselective acyloin rearrangement of acyclic aldehydes to synthesize highly optically active acyloin derivatives is described. In the presence of a chiral oxazaborolidinium ion catalyst, the reaction provided chiral α-hydroxy aryl ketones in high yield (up to 95%) and enantioselectivity (up to 98% ee). In addition, the enantioselective acyloin rearrangement of α,α-dialkyl-α-siloxy aldehydes produced chiral α-siloxy alkyl ketones in high yield (up to 92%) with good enantioselectivity (up to 89% ee).

5.
Prog Neurobiol ; 197: 101939, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33152398

RESUMO

Gaucher disease (GD) is currently the focus of considerable attention due primarily to the association between the gene that causes GD (GBA) and Parkinson's disease. Mouse models exist for the systemic (type 1) and for the acute neuronopathic forms (type 2) of GD. Here we report the generation of a mouse that phenotypically models chronic neuronopathic type 3 GD. Gba-/-;Gbatg mice, which contain a Gba transgene regulated by doxycycline, accumulate moderate levels of the offending substrate in GD, glucosylceramide, and live for up to 10 months, i.e. significantly longer than mice which model type 2 GD. Gba-/-;Gbatg mice display behavioral abnormalities at ∼4 months, which deteriorate with age, along with significant neuropathology including loss of Purkinje neurons. Gene expression is altered in the brain and in isolated microglia, although the changes in gene expression are less extensive than in mice modeling type 2 disease. Finally, bone deformities are consistent with the Gba-/-;Gbatg mice being a genuine type 3 GD model. Together, the Gba-/-;Gbatg mice share pathological pathways with acute neuronopathic GD mice but also display differences that might help understand the distinct disease course and progression of type 2 and 3 patients.


Assuntos
Doença de Gaucher , Células de Purkinje , Animais , Encéfalo , Modelos Animais de Doenças , Doença de Gaucher/genética , Glucosilceramidase/genética , Humanos , Camundongos
6.
Mol Genet Genomic Med ; 8(11): e1451, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32931663

RESUMO

BACKGROUND: Niemann-Pick type C (NPC, MIM #257220) is a neuro-visceral disease, caused predominantly by pathogenic variants in the NPC1 gene. Here we studied patients with clinical diagnosis of NPC but inconclusive results regarding the molecular analysis. METHODS: We used a Next-Generation Sequencing (NGS)-panel followed by cDNA analysis. Latter, we used massively parallel single-cell RNA-seq (MARS-Seq) to address gene profiling changes and finally the effect of different variants on the protein and cellular levels. RESULTS: We identified novel variants and cDNA analysis allowed us to establish the functional effect of a silent variant, previously reported as a polymorphism. We demonstrated that this variant induces the skipping of exon 11 leading to a premature stop codon and identified it in NPC patients from two unrelated families. MARS-Seq analysis showed that a number of upregulated genes were related to the unfolded protein response (UPR) and endoplasmic reticulum (ER) stress in one specific patient. Also, for all analyzed variants, the NPC1 protein was partially retained in the ER. CONCLUSION: We showed that the NPC1 silent polymorphism (p.V562V) is a disease-causing variant in NPC and that the UPR is upregulated in an NPC patient.


Assuntos
Peptídeos e Proteínas de Sinalização Intracelular/genética , Doença de Niemann-Pick Tipo C/genética , Mutação Silenciosa , Resposta a Proteínas não Dobradas , Células Cultivadas , Criança , Éxons , Fibroblastos/metabolismo , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteína C1 de Niemann-Pick , Doença de Niemann-Pick Tipo C/metabolismo , Splicing de RNA
7.
J Neuroinflammation ; 17(1): 265, 2020 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-32892753

RESUMO

BACKGROUND: The type 1 interferon (IFN) response is part of the innate immune response and best known for its role in viral and bacterial infection. However, this pathway is also induced in sterile inflammation such as that which occurs in a number of neurodegenerative diseases, including neuronopathic Gaucher disease (nGD), a lysosomal storage disorder (LSD) caused by mutations in GBA. METHODS: Mice were injected with conduritol B-epoxide, an irreversible inhibitor of acid beta-glucosidase, the enzyme defective in nGD. MyTrMaSt null mice, where four adaptors of pathogen recognition receptors (PRRs) are deficient, were used to determine the role of the IFN pathway in nGD pathology. Activation of inflammatory and other pathways was analyzed by a variety of methods including RNAseq. RESULTS: Elevation in the expression of PRRs associated with the IFN response was observed in CBE-injected mice. Ablation of upstream pathways leading to IFN production had no therapeutic benefit on the lifespan of nGD mice but attenuated neuroinflammation. Primary and secondary pathological pathways (i.e., those associated or not with mouse survival) were distinguished, and a set of ~210 genes including those related to sphingolipid, cholesterol, and lipoprotein metabolism, along with a number of inflammatory pathways related to chemokines, TNF, TGF, complement, IL6, and damage-associated microglia were classified as primary pathological pathways, along with some lysosomal and neuronal genes. CONCLUSIONS: Although IFN signaling is the top elevated pathway in nGD, we demonstrate that this pathway is not related to mouse viability and is consequently defined as a secondary pathology pathway. By elimination, we defined a number of critical pathways that are directly related to brain pathology in nGD, which in addition to its usefulness in understanding pathophysiological mechanisms, may also pave the way for the development of novel therapeutic paradigms by targeting such pathways.


Assuntos
Doença de Gaucher/metabolismo , Interferon Tipo I/metabolismo , Microglia/metabolismo , Neurônios/metabolismo , Transdução de Sinais/genética , Animais , Modelos Animais de Doenças , Doença de Gaucher/genética , Doença de Gaucher/patologia , Glucosilceramidase/genética , Glucosilceramidase/metabolismo , Camundongos , Camundongos Knockout , Neurônios/patologia
8.
Org Lett ; 22(8): 3171-3175, 2020 04 17.
Artigo em Inglês | MEDLINE | ID: mdl-32251599

RESUMO

In the presence of a catalytic amount of either Zn(acac)2 or bis(2,2,6,6-tetramethyl-3,5-heptanedionato)zinc(II) (Zn(TMHD)2), primary, secondary, and tertiary alcohol substituents on a wide range of substrates, including acyclic and cyclic structures, carbohydrates, steroids, and amino acids, reacted with dimethyl phosphite to afford the corresponding H-phosphonate diesters in high to excellent yields.

9.
J Neurochem ; 148(5): 625-638, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-29900534

RESUMO

Approximately 70 lysosomal storage diseases are currently known, resulting from mutations in genes encoding lysosomal enzymes and membrane proteins. Defects in lysosomal enzymes that hydrolyze sphingolipids have been relatively well studied. Gaucher disease is caused by the loss of activity of glucocerebrosidase, leading to accumulation of glucosylceramide. Gaucher disease exhibits a number of subtypes, with types 2 and 3 showing significant neuropathology. Sandhoff disease results from the defective activity of ß-hexosaminidase, leading to accumulation of ganglioside GM2. Niemann-Pick type C disease is primarily caused by the loss of activity of the lysosomal membrane protein, NPC1, leading to storage of cholesterol and sphingosine. All three disorders display significant neuropathology, accompanied by neuroinflammation. It is commonly assumed that neuroinflammation is the result of infiltration of monocyte-derived macrophages into the brain; for instance, cells resembling lipid-engorged macrophages ('Gaucher cells') have been observed in the brain of Gaucher disease patients. We now review the evidence that inflammatory macrophages are recruited into the brain in these diseases and then go on to provide some experimental data that, at least in the three mouse models tested, monocyte-derived macrophages do not appear to infiltrate the brain. Resident microglia, which are phenotypically distinct from infiltrating macrophages, are the only myeloid population present in significant numbers within the brain parenchyma in these authentic mouse models, even during the late symptomatic stages of disease when there is substantial neuroinflammation. OPEN SCIENCE BADGES: This article has received a badge for *Open Materials* because it provided all relevant information to reproduce the study in the manuscript. The complete Open Science Disclosure form for this article can be found at the end of the article. More information about the Open Practices badges can be found at https://cos.io/our-services/open-science-badges/. This article is part of the Special Issue "Lysosomal Storage Disorders".


Assuntos
Encéfalo/patologia , Doenças por Armazenamento dos Lisossomos/patologia , Células Mieloides/patologia , Animais , Modelos Animais de Doenças , Camundongos
10.
Hum Mol Genet ; 27(15): 2725-2738, 2018 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-29771310

RESUMO

Mucolipidosis IV (MLIV) is an orphan neurodevelopmental disease that causes severe neurologic dysfunction and loss of vision. Currently there is no therapy for MLIV. It is caused by loss of function of the lysosomal channel mucolipin-1, also known as TRPML1. Knockout of the Mcoln1 gene in a mouse model mirrors clinical and neuropathologic signs in humans. Using this model, we previously observed robust activation of microglia and astrocytes in early symptomatic stages of disease. Here we investigate the consequence of mucolipin-1 loss on astrocyte inflammatory activation in vivo and in vitro and apply a pharmacologic approach to restore Mcoln1-/- astrocyte homeostasis using a clinically approved immunomodulator, fingolimod. We found that Mcoln1-/- mice over-express numerous pro-inflammatory cytokines, some of which were also over-expressed in astrocyte cultures. Changes in the cytokine profile in Mcoln1-/- astrocytes are concomitant with changes in phospho-protein signaling, including activation of PI3K/Akt and MAPK pathways. Fingolimod promotes cytokine homeostasis, down-regulates signaling within the PI3K/Akt and MAPK pathways and restores the lysosomal compartment in Mcoln1-/- astrocytes. These data suggest that fingolimod is a promising candidate for preclinical evaluation in our MLIV mouse model, which, in case of success, can be rapidly translated into clinical trial.


Assuntos
Astrócitos/efeitos dos fármacos , Astrócitos/patologia , Encéfalo/efeitos dos fármacos , Cloridrato de Fingolimode/farmacologia , Mucolipidoses/patologia , Animais , Encéfalo/metabolismo , Encéfalo/patologia , Células Cultivadas , Citocinas/metabolismo , Modelos Animais de Doenças , Encefalite/tratamento farmacológico , Encefalite/genética , Encefalite/metabolismo , Encefalite/patologia , Feminino , Regulação da Expressão Gênica , Proteínas de Membrana Lisossomal/metabolismo , Masculino , Camundongos Knockout , Mucolipidoses/tratamento farmacológico , Fosfatidilinositol 3-Quinases/metabolismo , Fosfoproteínas/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Canais de Potencial de Receptor Transitório/genética , Canais de Potencial de Receptor Transitório/metabolismo
11.
Rice (N Y) ; 11(1): 3, 2018 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-29322324

RESUMO

BACKGROUND: Bakanae or foot rot disease is a prominent disease of rice caused by Gibberella fujikuroi. This disease may infect rice plants from the pre-emergence stage to the mature stage. In recent years, raising rice seedlings in seed boxes for mechanical transplanting has increased the incidence of many seedling diseases; only a few rice varieties have been reported to exhibit resistance to bakanae disease. In this study, we attempted to identify quantitative trait loci (QTLs) conferring bakanae disease resistance from the highly resistant japonica variety Wonseadaesoo. RESULTS: A primary QTL study using the genotypes/phenotypes of the recombinant inbred lines (RILs) indicated that the locus qBK1 WD conferring resistance to bakanae disease from Wonseadaesoo was located in a 1.59 Mb interval delimited on the physical map between chr01_13542347 (13.54 Mb) and chr01_15132528 (15.13 Mb). The log of odds (LOD) score of qBK1 WD was 8.29, accounting for 20.2% of the total phenotypic variation. We further identified a gene pyramiding effect of two QTLs, qBK WD and previously developed qBK1. The mean proportion of healthy plant for 31 F4 RILs that had no resistance genes was 35.3%, which was similar to that of the susceptible check variety Ilpum. The proportion of healthy plants for the lines with only qBK WD or qBK1 was 66.1% and 55.5%, respectively, which was significantly higher than that of the lines without resistance genes and that of Ilpum. The mean proportion of the healthy plant for 15 F4 RILs harboring both qBK WD and qBK1 was 80.2%, which was significantly higher than that of the lines with only qBK WD or qBK1. CONCLUSION: Introducing qBK WD or pyramiding the QTLs qBK WD and qBK1 could provide effective tools for breeding rice with bakanae disease resistance. To our knowledge, this is the first report on a gene pyramiding effect that provides higher resistance against bakanae disease.

12.
Artigo em Inglês | MEDLINE | ID: mdl-29136552

RESUMO

Over the past few decades, honey products have been polluted by different contaminants, such as pesticides, which are widely applied in agriculture. In this work, a modified EN - quick, easy, cheap, effective, rugged, and safe (QuEChERS) extraction method was developed for the simultaneous quantification of pesticide residues, including cymiazole, fipronil, coumaphos, fluvalinate, amitraz, and its metabolite 2,4-dimethylaniline (2,4-DMA), in four types of honey (acacia, wild, chestnut, and manuka) and royal jelly. Samples were buffered with 0.2M dibasic sodium phosphate (pH 9), and subsequently, acetonitrile was employed as the extraction solvent. A combination of primary secondary amine (PSA) and C18 sorbents was used for purification prior to liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI+/MS-MS) analysis. The estimated linearity measured at six concentration levels presented good correlation coefficients (R2)≥0.99. The recovery, calculated from three different spiking levels, was 62.06-108.79% in honey and 67.58-106.34% in royal jelly, with an RSD<12% for all the tested compounds. The matrix effect was also evaluated, and most of the analytes presented signal enhancement. The limits of quantification (LOQ) ranged between 0.001 and 0.005mg/kg in various samples. These are considerably lower than the maximum residue limits (MRL) set by various regulatory authorities. A total of 43 market (domestic and imported) samples were assayed for method application. Among the tested samples, three samples were tested positive (i.e. detected and quantified) only for cymiazole residues. The residues in the rest of the samples were detected but not quantified. We concluded that the protocol developed in this work is simple and versatile for the routine quantification of cymiazole, 2,4-DMA, fipronil, coumaphos, amitraz, and fluvalinate in various types of honey and royal jelly.


Assuntos
Cromatografia Líquida/métodos , Ácidos Graxos/química , Mel/análise , Resíduos de Praguicidas/análise , Espectrometria de Massas em Tandem/métodos , Cumafos , Limite de Detecção , Modelos Lineares , Nitrilas , Resíduos de Praguicidas/metabolismo , Pirazóis , Piretrinas , Reprodutibilidade dos Testes , Tiazóis , Toluidinas
13.
Artigo em Inglês | MEDLINE | ID: mdl-28918317

RESUMO

Herein, we developed a simple analytical procedure for the quantitation of bithionol residues in animal-derived food products such as porcine muscle, eggs, milk, eel, flatfish, and shrimp using a modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) extraction method coupled with liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI+/MS-MS). Samples were extracted with 0.1% solution of formic acid in acetonitrile and the extract was purified using a C18 sorbent. Separation was performed on a Waters XBridge™ C18 reversed-phase analytical column using 0.1% solution of formic acid/acetonitrile as the mobile phase. Six-point matrix-matched calibration indicated good linearity, with the calculated coefficients of determination (R2) being≥0.9813. Intra- and inter-day recoveries (determined at spiking levels equivalent to 1×and 2×the limit of quantitation (0.25µg/kg)) ranged between 80.0 and 94.0%, with the corresponding relative standard deviations (RSDs) being≤8.2%. The developed experimental protocol was applied to different samples purchased from local markets in Seoul, which were tested negative for bithionol residues. In conclusion, the proposed method proved to be versatile and precise, being ideally suited for the routine detection of bithionol residues in animal-derived food products with various protein and fat contents.


Assuntos
Bitionol/análise , Cromatografia Líquida/métodos , Resíduos de Drogas/análise , Contaminação de Alimentos/análise , Espectrometria de Massas em Tandem/métodos , Animais , Bitionol/química , Bitionol/isolamento & purificação , Fracionamento Químico/métodos , Resíduos de Drogas/química , Resíduos de Drogas/isolamento & purificação , Ovos/análise , Limite de Detecção , Modelos Lineares , Leite/química , Reprodutibilidade dos Testes , Alimentos Marinhos/análise
14.
J Chromatogr B Analyt Technol Biomed Life Sci ; 1065-1066: 29-34, 2017 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-28946122

RESUMO

In this study, a simple analytical approach has been developed and validated for the determination of bupivacaine hydrochloride and isoflupredone acetate residues in porcine muscle, beef, milk, egg, shrimp, flatfish, and eel using liquid chromatography-tandem mass spectrometry (LC-MS/MS). A 0.1% solution of acetic acid in acetonitrile combined with n-hexane was used for deproteinization and defatting of all tested matrices and the target drugs were well separated on a Waters Xbridge™ C18 analytical column using a mobile phase consisting of 0.1% acetic acid (A) and 0.1% solution of acetic acid in methanol (B). The linearity estimated from six-point matrix-matched calibrations was good, with coefficients of determination ≥0.9873. The limits of quantification (LOQs) for bupivacaine hydrochloride and isoflupredone acetate were 1 and 2ngg-1, respectively. Recovery percentages in the ranges of 72.51-112.39% (bupivacaine hydrochloride) and 72.58-114.56% (isoflupredone acetate) were obtained from three different fortification concentrations with relative standard deviations (RSDs) of <15.14%. All samples for the experimental work and method application were collected from the local markets in Seoul, Republic of Korea, and none of them tested positive for the target drugs. In conclusion, a simple method using a 0.1% solution of acetic acid in acetonitrile and n-hexane followed by LC-MS/MS could effectively extract bupivacaine hydrochloride and isoflupredone acetate from porcine muscle, beef, milk, egg, shrimp, flatfish, and eel samples.


Assuntos
Bupivacaína/análise , Resíduos de Drogas/análise , Fluprednisolona/análogos & derivados , Leite/química , Carne Vermelha/análise , Alimentos Marinhos/análise , Animais , Cromatografia Líquida/métodos , Enguias , Linguados , Fluprednisolona/análise , Modelos Lineares , Penaeidae , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Suínos , Espectrometria de Massas em Tandem/métodos
15.
Oncol Lett ; 14(2): 2410-2416, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28789457

RESUMO

Epithelial-mesenchymal transition (EMT) is a notable mechanism underlying cancer cell metastasis. Transforming growth factor ß1 (TGF-ß1) has been used to induce EMT; however, there is a lack of information regarding the role of TGF-ß1 in mesenchymal-epithelial transition (MET). In the present study, EMT was induced in A549 lung cancer cells using TGF-ß1 (TGF-ß1-treated group) and MET was induced sequentially from the TGF-ß1-treated group by removing the TGF-ß1 (MET/return group). Untreated A549 lung cancer cells were used as a control. Characteristic features, including cancer stem cell markers [cluster of differentiation (CD)24, CD44 and CD133], cell proliferation and migration and diverse intracellular mechanisms, were observed in all groups. Using western blot analysis, the TGF-ß1-treated group demonstrated increased vimentin and reduced E-cadherin expression, whereas the MET/return group demonstrated the opposite trend. Among cancer stem cell markers, the population of CD24low cells was reduced in the TGF-ß1-treated group. Furthermore, the G2/M phase cell cycle population, cisplatin-sensitivity, and cell proliferation and migration ability were increased in the TGF-ß1-treated group. These features were unaltered in the MET/return group when compared to the TGF-ß1-treated group. Immunoblotting revealed an increase in the levels of SMAD3, phosphorylated SMAD3, phosphorylated extracellular signal-regulated kinase and caspase-3, and a decrease in active caspase-3 levels in the TGF-ß1-treated group. Increased caspase-3 and reduced active caspase-3 levels were observed in the MET/return group, similar to those in the TGF-ß1-treated group; however, levels of other signalling proteins were unchanged compared with the control group. EMT induced by TGF-ß1 was not preserved; however, stemness-associated properties (CD24 expression, caspase-3 expression, cell proliferation and cisplatin-resistance) were sustained following removal of TGF-ß1.

16.
Org Lett ; 19(9): 2434-2437, 2017 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-28445063

RESUMO

l-Proline-derived chiral bifunctional (thio)urea organocatalysts epi-PTU and epi-PU were newly synthesized, and their catalytic performances were compared with their C6 epimeric catalysts PTU and PU in various Michael reactions of nitrostyrene in terms of reactivities and stereoselectivities. The experimental results indicate that a proper relative stereochemistry at C2 and C6 in l-proline-derived bifunctional organocatalysts is important for successful catalysis and that catalysts (PTU and PU) with the 2S,6R configuration are much more efficient.

17.
Angew Chem Int Ed Engl ; 56(30): 8663-8666, 2017 07 17.
Artigo em Inglês | MEDLINE | ID: mdl-28418120

RESUMO

A Michael addition initiated cyclopropanation/retro-Claisen rearrangement tandem reaction was developed for the enantioselective synthesis of highly functionalized 2,5-dihydrooxepines. In the presence of a chiral oxazaborolidinium ion (COBI) catalyst, the reaction proceeds to give good yields and high enantioselectivity.

18.
BJR Case Rep ; 3(2): 20160107, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-30363301

RESUMO

Adrenal haemorrhage is a rare condition that has the potential to cause life-threatening adrenal insufficiency, especially if it affects both the adrenal glands. The difficulty in diagnosing adrenal haemorrhages lies in the non-specific clinical presentation including hypotension and abdominal pain. The following case report demonstrates the possible clinical presentations of non-traumatic adrenal haemorrhages and the method of diagnosing and treating adrenal insufficiency. In a medical era where overdiagnosis and "incidentalomas" are becoming more prevalent, this case nicely demonstrates the fortunate use of imaging to detect a potentially life-threatening condition.

19.
Biomed Chromatogr ; 31(6)2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27862109

RESUMO

In this study, an analytical method was developed for quantification of residues of the anthelmintic drug phenothiazine (PTZ) in pork muscle using liquid chromatography-tandem mass spectrometry. Muscles were extracted using 0.2% formic acid and 10 mm ammonium formate in acetonitrile, defatted and purified using n-hexane. The drug was well separated on a Waters XBridge™ C18 analytical column using a binary solvent system consisting of 0.2% formic acid and 10 mm ammonium formate in ultrapure water (A) and acetonitrile (B). Good linearity was achieved over a six-point concentration range in matrix-matched calibration with determination coefficient =0.9846. Fortified pork muscle having concentrations equivalent to and double the limit of quantification (1 ng/g) yielded recovery ranges between 100.82 and 104.03% and relative standard deviations <12%. Samples (n = 5) collected from large markets located in Seoul City tested negative for PTZ residue. In conclusion, 0.2% formic acid and ammonium formate in acetonitrile can effectively extract PTZ from pork muscle without solid-phase extraction, a step normally required for cleanup before analysis and the validated method can be used for routine analysis to ensure the quality of animal products.


Assuntos
Cromatografia Líquida/métodos , Produtos da Carne/análise , Músculos/química , Fenotiazinas/análise , Espectrometria de Massas em Tandem/métodos , Animais , Limite de Detecção , Suínos
20.
Sci Rep ; 6: 20185, 2016 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-26830653

RESUMO

Amyloid-ß (Aß) plays a critical role as a biomarker in Alzheimer's disease (AD) diagnosis. In addition to its diagnostic potential in the brain, recent studies have suggested that changes of Aß level in the plasma can possibly indicate AD onset. In this study, we found that plasma Aß(1-42) concentration increases with age, while the concentration of Aß(1-42) in the cerebrospinal fluid (CSF) decreases in APPswe, PS1M146V and TauP301L transgenic (3xTg-AD) mice, if measurements were made before formation of ThS-positive plaques in the brain. Our data suggests that there is an inverse correlations between the plasma and CSF Aß(1-42) levels until plaques form in transgenic mice's brains and that the plasma Aß concentration possesses the diagnostic potential as a biomarker for diagnosis of early AD stages.


Assuntos
Envelhecimento/líquido cefalorraquidiano , Doença de Alzheimer/sangue , Doença de Alzheimer/líquido cefalorraquidiano , Peptídeos beta-Amiloides/sangue , Peptídeos beta-Amiloides/líquido cefalorraquidiano , Encéfalo/metabolismo , Fragmentos de Peptídeos/sangue , Fragmentos de Peptídeos/líquido cefalorraquidiano , Placa Amiloide/sangue , Placa Amiloide/líquido cefalorraquidiano , Envelhecimento/sangue , Animais , Barreira Hematoencefálica/metabolismo , Feminino , Humanos , Imuno-Histoquímica , Camundongos Transgênicos , Fosforilação , Transporte Proteico
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