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1.
World J Clin Cases ; 11(29): 7101-7106, 2023 Oct 16.
Article de Anglais | MEDLINE | ID: mdl-37946771

RÉSUMÉ

BACKGROUND: Varicella-zoster virus (VZV) is a common viral infection, but meningitis is a rare complication of VZV infection. The cerebrospinal fluid glucose of viral meningitis is usually within the normal range, which is different from bacteria, fungi, and cancerous meningitis. This paper reports a case of VZV meningitis with hypoglycorrhachia and the relevant literature was reviewed. CASE SUMMARY: We report a case of an immunocompetent 39-year-old male, presenting with severe headache and fevers, without meningeal signs or exanthem, found to have VZV meningitis by the metagenomic next-generation sequencing of cerebrospinal fluid. The cerebrospinal fluid analysis revealed hypoglycorrhachia (cerebrospinal fluid glucose of 2.16) and he was treated successfully with intravenous acyclovir. Our literature review identified only ten cases diagnosed with VZV meningitis with hypoglycorrhachia previously reported to date in the English literature whose cerebrospinal fluid glucose was from 1.6 to 2.7mmol/L, with a ratio of cerebrospinal fluid to serum glucose from 0.30 to 0.49. CONCLUSION: Although rare, the cerebrospinal fluid of patients with VZV meningitis may have hypoglycorrhachia, which broadens the understanding of the disease.

2.
Clin Chim Acta ; 533: 122-130, 2022 Aug 01.
Article de Anglais | MEDLINE | ID: mdl-35750085

RÉSUMÉ

OBJECTIVE: This study aims to establish an optimization procedure to define the cut-offs of quantitative assays for acetylcholine receptor antibody (AChRAb), evaluate their diagnostic performance in myasthenia gravis (MG), and explore the association with clinical features. METHODS: Samples from a representative cohort of 77 MG patients, 80 healthy controls (HC) and 80 other autoimmune diseases (OAD) patients were tested using competitive inhibition ELISA and RIA. Raw values (OD and cpm) and processed values (inhibition rate, binding rate and concentration) were used to define the cut-offs with statistical methods, a rough method, and receiver operating characteristic (ROC) curve. Optimal cut-offs were selected by comparing false positive rates in HC and OAD individuals. The diagnostic performance was evaluated in whole MG cohort and subgroups. Agreement between ELISA and RIA for AChRAb positivity were examined with Kappa test and McNemar test. Clinical association with AChRAb was explored by comparison among subgroups and with Spearman rank correlation. RESULTS: The optimal cut-offs for AChRAb positivity were determined as OD ≤ 1.79 for ELISA and cpm ≥ 1234.12 for RIA, which derived from statistical method and performed better than those derived from ROC curves. The sensitivity and specificity were 74.03%, 100% for ELISA, and 74.03%, 99.37% for RIA. There was good agreement between ELISA and RIA for AChRAb positivity in whole cohort and subgroups (weighted к ≥ 0.71, p < 0.01; McNemar test, p > 0.05). Levels of AChRAb were different in MG subgroups (p < 0.01). Correlation between Quantitative Myasthenia Gravis scores and AChRAb levels was moderate for ELISA and RIA (rs = -0.60 and 0.57, p < 0.01). CONCLUSION: The raw testing values of ELISA and RIA were found as optimal quantitative measures of AChRAb levels. There are good agreements on diagnostic performance between two assays. Quantitative values are more informative than positivity in association with clinical features.


Sujet(s)
Myasthénie , Récepteurs cholinergiques , Autoanticorps , Test ELISA , Humains , Tests immunologiques , Myasthénie/diagnostic , Récepteurs cholinergiques/immunologie
3.
World J Clin Cases ; 9(6): 1359-1366, 2021 Feb 26.
Article de Anglais | MEDLINE | ID: mdl-33644203

RÉSUMÉ

BACKGROUND: Central nervous system graft-vs-host disease (CNS-GVHD) is a rare cause of CNS disorders after allogeneic hematopoietic stem cell transplantation. Currently, establishing a diagnosis of CNS-GVHD is challenging because the diagnostic criteria and diagnostic methods are not well defined and many confounding factors need to be ruled out. CASE SUMMARY: Here, we present two patients with CNS-GVHD. Both patients with a history of acute GVHD or chronic GVHD developed neurological symptoms that could not be explained by other causes, and had abnormal cerebrospinal fluid (CSF) studies as determined by CSF and blood immune biomarker examinations, suggestive of suspected CNS-GVHD. Due to the lack of specific magnetic resonance imaging abnormalities and the rapid clinical deterioration of the patients, we did not attempt to perform a brain biopsy, but prompted the initiation of empirical immunosuppressive therapy. In view of the rapid and favorable response to local and systematic immunosuppressive treatment and the aforementioned neurologic manifestations together with CSF abnormalities and other negative findings, a final diagnosis of CNS-GVHD was made. CONCLUSION: CSF and blood immune biomarker examinations facilitated the diagnosis of CNS-GVHD, which are particularly suitable for patients who are critically ill and require urgent treatment and for those who are unsuitable for invasive diagnostic procedures.

4.
Front Neurol ; 12: 604052, 2021.
Article de Anglais | MEDLINE | ID: mdl-33633666

RÉSUMÉ

Myasthenia gravis (MG) is an autoimmune disease in which antibodies bind to acetylcholine receptors (AChR) or other functional molecules in the postsynaptic membrane at the neuromuscular junction. Vitamin D (VD) has a number of pluripotent effects, which include immune-regulation and bone metabolism. The immunomodulatory actions of 1,25(OH)2D3 are mediated by its binding to a vitamin D receptor (VDR). In the study, we undertook a case-control study to explore the association between VDR gene polymorphism and the susceptibility and severity of MG patients. Four hundred and eighty MG patients and 487 healthy controls were included and gene polymorphisms of VDR were determined with improved multiplex ligation detection reaction technique and SNPscanTM technique. MG patients were classified into subgroups by essential clinical features and by a comprehensive classification. The frequencies of alleles and genotypes were compared between the MG group and the control group, between each MG subgroup and the control group, and between each pair of MG subgroups. There were no significant differences in frequencies of alleles and genotypes between MG patients and healthy controls, between MG subgroups and healthy controls, or between each pair of MG subgroups in the analysis of subgroups classified by essential clinical features (onset age, gender, thymoma, AChRAb positivity, onset involvement) and the maximal severity (modified Oosterhuis score). In the analysis of subgroups with a comprehensive classification, the frequencies of alleles and genotypes in rs731236 showed significant differences between adult non-thymoma AChRAb negative MG subgroup and the control group, as well as the adult non-thymoma AChRAb positive MG group. In the Chinese Han population, rs731236 was found to be possibly associated with adult non-thymoma AChRAb negative MG patients, although this needs further confirmation.

5.
J Neuroimmunol ; 353: 577487, 2021 04 15.
Article de Anglais | MEDLINE | ID: mdl-33578311

RÉSUMÉ

Complement component 3 (C3) had been proved to be involved in the pathogenesis and exacerbation of both myasthenia gravis (MG) patients and experimental autoimmune myasthenia gravis (EAMG) models. We evaluated the underlying association between five SNPs (rs344555, rs7951, rs3745568, rs366510 and rs163913) in C3 gene and Chinese adult MG patients. Our study consisted of 409 adult MG patients and 487 healthy controls. Subgroups were classified by gender, onset age, thymoma, anti-AChR antibody, onset muscle involvement (ocular/generalized) and severity (Oosterhuis score at the maximal severity during the initial two years after the onset of MG). We found significant differences in allele frequencies between MG and the control group, between various MG subgroups and the control group in rs344555 and rs3745568. There were significant differences in genotype frequencies between MG group and the control group, between MG subgroups and the control group under the codominant and additive inheritance models in rs344555 and rs3745568. No association was found between the frequencies of these SNPs and the severity of MG. We also used a comprehensive classification which was close to the clinical scenario to minimize the interaction among clinical features. In rs344555, the T allele frequency in thymoma (-) AChR-Ab (+) subgroup was significantly higher than that in the control group. Our results indicated that rs344555 was associated with the susceptibility of Chinese adult MG patients; rs3745568 was probably associated with the susceptibility of Chinese adult MG patients. No association was found between the frequencies of these SNPs and the severity of MG.


Sujet(s)
Complément C3/génétique , Prédisposition génétique à une maladie/génétique , Myasthénie/génétique , Adolescent , Adulte , Sujet âgé , Sujet âgé de 80 ans ou plus , Asiatiques/génétique , Femelle , Humains , Mâle , Adulte d'âge moyen , Polymorphisme de nucléotide simple , Jeune adulte
7.
J Clin Neurosci ; 69: 31-37, 2019 Nov.
Article de Anglais | MEDLINE | ID: mdl-31473094

RÉSUMÉ

Abnormal CTLA-4 expression is involved in the development of myasthenia gravis (MG), and serum CTLA-4 levels are positively correlated with serum anti-AChR antibody concentration, which might be related with the severity of MG. Polymorphism in CTLA-4 gene is associated with various autoimmune disorders. We investigated the association of polymorphism in CTLA-4 gene with the clinical variables and severity of MG. The frequencies of alleles and genotypes were compared between 480 MG patients and 487 healthy controls, as well as among subgroups of MG patients. The frequency of rs733618*C allele is significantly higher in MG group and several subgroups than in control group. Genotype is not found as independent factor for essential clinical variables of MG. The frequency of rs231775*A allele is significantly lower in ocular onset subgroup than in control group, and the frequencies of rs231775*A allele and rs3087243*A allele are significantly lower in ocular onset subgroup than in generalized onset subgroup. Genotypes of the two SNPs are found as independent factors for ocular onset. The frequency of rs231775*A allele is significantly lower in mild subgroup than that in control group. Genotype is not found as independent factor for mild severity. A haplotype containing rs733618*C, rs231775*G and rs3087243*G is identified to increase the general risk of MG by 1.278-fold and ocular onset MG subgroup by 1.362-fold. There is association of rs733618 with the general susceptibility of MG, and association of rs231775 and rs3087243 with the susceptibility of ocular onset MG, but no association with the severity of MG.


Sujet(s)
Antigène CTLA-4/génétique , Prédisposition génétique à une maladie/génétique , Myasthénie/génétique , Adulte , Asiatiques/génétique , Femelle , Génotype , Humains , Mâle , Adulte d'âge moyen , Polymorphisme de nucléotide simple
8.
Front Neurol ; 9: 529, 2018.
Article de Anglais | MEDLINE | ID: mdl-30042722

RÉSUMÉ

Interleukin-4 (IL-4) is a potent growth and differentiation factor for B cells which play a vital role in the pathogenesis of myasthenia gravis (MG). IL-4 exerts its function by binding to three types of IL-4 receptor (IL-4R) complexes. IL-4Rα is the key component of the IL-4R complex. We hypothesize that polymorphism of IL-4Rα gene may be associated with the susceptibility and severity of MG. A Chinese cohort of 480 MG patients and 487 healthy controls were recruited. Polymorphisms of IL-4Rα gene were determined with SNPscan™ methods and compared between MG and control groups, as well as among MG subgroups. Rs2107356 and rs1805010 were found to be associated with adult thymoma associated MG, and rs1801275 was found to be associated with adult non-thymoma AChR-Ab positive MG. We did not found association between IL-4Rα polymorphism and the severity of MG. Genetic variations of IL-4Rα were found associated with the susceptibility of MG in Chinese Han population.

9.
J Clin Neurosci ; 40: 180-184, 2017 Jun.
Article de Anglais | MEDLINE | ID: mdl-28262400

RÉSUMÉ

Polymorphism in autoimmune regulator (AIRE) gene is associated with various autoimmune disorders. Abnormal AIRE expression is associated with the development of myasthenia gravis (MG). We investigated the association of polymorphism in AIRE gene and the clinical features and severity of MG. The frequencies of alleles and genotypes were compared between 480MG patients and 487 healthy controls, as well as among subgroups of MG patients. The frequencies of rs3761389G allele in MG group (OR=1.213, CI 95% 1.014-1.451, p=0.035) and in mild (Oosterhuis score 0-2) subgroup (OR=1.393, CI 95% 1.110-1.751, p=0.004) were significantly higher than those in the control group. There were significant differences in the frequencies of rs3761389 genotypes (OR=1.20, CI 95% 1.00-1.43, p=0.046, log-additive model) and mild subgroup (OR=1.32, CI 95% 1.03-1.69, p=0.0058, log-additive model) compared with the control group. A Logistic regression analysis did not identify rs3761389 genotype as an independent risk factor to predict the severity of MG. This study provides the necessary preliminary data on the association with rs3761389 in AIRE gene with the susceptibility of MG, but not with the severity of MG.


Sujet(s)
Myasthénie/génétique , Polymorphisme de nucléotide simple , Facteurs de transcription/génétique , Adolescent , Adulte , Sujet âgé , Sujet âgé de 80 ans ou plus , Allèles , Asiatiques/génétique , Études cas-témoins , Enfant , Enfant d'âge préscolaire , Femelle , Humains , Nourrisson , Mâle , Adulte d'âge moyen ,
10.
Mol Neurobiol ; 54(6): 4771-4780, 2017 08.
Article de Anglais | MEDLINE | ID: mdl-27501803

RÉSUMÉ

Myasthenia gravis (MG) is an antibody-mediated autoimmune disease against antigens at the neuromuscular junction. Both genetic and environmental factors contribute to the susceptibility of MG. We undertook a case-control study to explore the contribution of genes of the auto-antigen and immune-modulating proteins in the pathogenesis of MG. We enrolled 389 adult MG patients and 487 healthy controls. Eighteen SNPs were selected from genes of cholinergic receptor nicotinic alpha 1 (CHRNA1), autoimmune regulator (AIRE), cytotoxic T lymphocyte-associated protein 4 (CTLA-4), protein tyrosine phosphatase nonreceptor type 22 (PTPN22), and interleukin-10 (IL-10). Rs16862847 and rs2229957 in CHRNA1, rs3761389 in AIRE, and rs733618 in CTLA-4 were significantly associated with MG, with the highest association in SNPs of CHRNA1. Carrier of rs16862847 G allele was found to be an independent risk factor in predicting high-level acetylcholine receptor (AChR) antibodies (P = 0.003, OR = 10.296). Genetic interaction analysis revealed a synergistic effect of CHRNA1 (rs16862847), AIRE (rs3761389), and CTLA-4 (rs733618) in the susceptibility of MG (P < 0.0001, OR = 1.95). These findings highlight the role of auto-antigen gene (CHRNA1) in the autoimmune reactions against AChR and reveal synergistic contribution of genes of both auto-antigen and immune-regulating proteins (AIRE and CTLA-4) in the pathogenesis of MG.


Sujet(s)
Autoantigènes/génétique , Prédisposition génétique à une maladie , Myasthénie/génétique , Myasthénie/immunologie , Protéines de tissu nerveux/génétique , Protéines de tissu nerveux/immunologie , Polymorphisme de nucléotide simple/génétique , Adolescent , Adulte , Sujet âgé , Sujet âgé de 80 ans ou plus , Allèles , Études cas-témoins , Épistasie , Femelle , Fréquence d'allèle/génétique , Études d'associations génétiques , Humains , Déséquilibre de liaison/génétique , Mâle , Adulte d'âge moyen , Modèles génétiques , Jeune adulte
11.
J Neuroimmunol ; 298: 51-7, 2016 09 15.
Article de Anglais | MEDLINE | ID: mdl-27609275

RÉSUMÉ

Myasthenia gravis (MG) is an autoimmune disorder with heterogeneity. Antibodies against acetylcholine receptor (AChR), muscle-specific kinase (MuSK), titin and ryanodine receptor (RyR) were examined in 437 adult Chinese MG patients. The AChR, MuSK, titin and RyR antibodies were found in 82.2%, 2.3%, 28.4% and 23.8% of all patients. Autoantibody profiles vary among different MG subgroups. Thymoma MG patients had high frequencies of AChR (99.2%), titin (50.8%) and RyR antibodies (46.9%). The titin and RyR antibodies also showed high frequencies in late onset patients (54.4% and 33.3%, respectively). These two antibodies may indicate an underlying thymoma when combined. The patients with titin and RyR antibodies tend to have more severe disease and worse outcome, and may need more active immunosuppressive treatment.


Sujet(s)
Autoanticorps/métabolisme , Myasthénie/immunologie , Récepteurs à activité tyrosine kinase/immunologie , Récepteurs cholinergiques/immunologie , Canal de libération du calcium du récepteur à la ryanodine/immunologie , Adolescent , Adulte , Sujet âgé , Sujet âgé de 80 ans ou plus , Asiatiques , Études de cohortes , Femelle , Humains , Mâle , Adulte d'âge moyen , Myasthénie/complications , Dosage radioimmunologique , Études rétrospectives , Indice de gravité de la maladie , Complexe shelterine , Protéines télomériques/immunologie , Thymome/complications , Thymome/immunologie , Jeune adulte
12.
Mult Scler Relat Disord ; 8: 74-7, 2016 Jul.
Article de Anglais | MEDLINE | ID: mdl-27456878

RÉSUMÉ

We described a female patient with anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis occurring sequentially with neuromyelitis optica spectrum disorders (NMOSD). The 19-year-old patient initially presented a diencephalic syndrome with aquaporin-4 immunoglobulin G antibodies (AQP4-IgG) and brain lesions which involving bilateral medial temporal lobes and periependymal surfaces of the third ventricle on magnetic resonance imaging (MRI). Ten months later, the patient developed cognitive impairment, psychiatric symptoms and dyskinesia with left basal ganglia lesions on brain MRI. Meanwhile, the anti-NMDAR antibodies were positive in the patient's serum and cerebrospinal fluid, while the screening tests for an ovarian teratoma and other tumors were all negative. Hence, the patient was diagnosed NMOSD and anti-NMDAR encephalitis followed by low-dose rituximab treatment with a good response. This case was another evidence for demyelinating syndromes overlapping anti-NMDAR encephalitis in Chinese patients.


Sujet(s)
Encéphalite à anticorps anti-récepteur N-méthyl-D-aspartate/complications , Neuromyélite optique/complications , Encéphalite à anticorps anti-récepteur N-méthyl-D-aspartate/imagerie diagnostique , Encéphalite à anticorps anti-récepteur N-méthyl-D-aspartate/traitement médicamenteux , Encéphale/imagerie diagnostique , Femelle , Humains , Facteurs immunologiques/usage thérapeutique , Neuromyélite optique/imagerie diagnostique , Neuromyélite optique/traitement médicamenteux , Rituximab/usage thérapeutique , Jeune adulte
13.
Ann Transl Med ; 4(6): 106, 2016 Mar.
Article de Anglais | MEDLINE | ID: mdl-27127759

RÉSUMÉ

Myasthenia gravis (MG) is a prototypic autoimmune disease with overt clinical and immunological heterogeneity. The data of MG is far from individually precise now, partially due to the rarity and heterogeneity of this disease. In this review, we provide the basic insights of MG data precision, including onset age, presenting symptoms, generalization, thymus status, pathogenic autoantibodies, muscle involvement, severity and response to treatment based on references and our previous studies. Subgroups and quantitative traits of MG are discussed in the sense of data precision. The role of disease registries and scientific bases of precise analysis are also discussed to ensure better collection and analysis of MG data.

14.
Neurol Sci ; 37(1): 123-130, 2016 Jan.
Article de Anglais | MEDLINE | ID: mdl-26337284

RÉSUMÉ

Alleles of IL-17A and IL-17F genes were reported to be associated with many inflammatory and autoimmune disorders in Asian patients. Serum level and mRNA of IL-17A in peripheral blood mononuclear cells were reported to be significantly higher in MG patients than in healthy controls. In experimental autoimmune myasthenia gravis (EAMG) animals, IL-17 may have effects on the severity of MG. This study investigated the association between four SNPs of IL-17A and IL-17F gene (rs8193036, rs2275913 and rs3748067 in IL-17A; rs763780 in IL-17F) and MG in Chinese patients. The allele frequencies were compared between 480 MG patients and 487 healthy controls, between each MG subgroup and the control group, and between each pairs of MG subgroups. Subgroups were specified by clinical features (onset age, gender, thymoma, AChRAb and muscle involvement at onset) and maximal severity during the follow-up. No associations were found between the four SNPs of IL-17A and IL-17F gene and MG in Chinese patients.


Sujet(s)
Interleukine-17/génétique , Myasthénie/génétique , Polymorphisme de nucléotide simple , Adolescent , Adulte , Sujet âgé , Sujet âgé de 80 ans ou plus , Asiatiques/génétique , Enfant , Enfant d'âge préscolaire , Chine , Femelle , Études de suivi , Fréquence d'allèle , Études d'associations génétiques , Humains , Nourrisson , Mâle , Adulte d'âge moyen , Indice de gravité de la maladie , Jeune adulte
15.
Chin Med J (Engl) ; 128(13): 1772-7, 2015 Jul 05.
Article de Anglais | MEDLINE | ID: mdl-26112719

RÉSUMÉ

BACKGROUND: Vanishing white matter disease (VWM), a human autosomal recessive inherited leukoencephalopathy, is due to mutations in eukaryotic initiation factor 2B (eIF2B). eIF2B is responsible for the initiation of protein synthesis by its guanine nucleotide exchange factor (GEF) activity. Mutations of eIF2B impair GEF activity at different degree. Previous studies implied improperly activated unfolded protein response (UPR) and endoplasmic reticulum stress (ERS) participated in the pathogenesis of VWM. Autophagy relieves endoplasmic reticulum load by eliminating the unfolded protein. It is still unknown the effects of genotypes on the pathogenesis. In this work, UPR and autophagy flux were analyzed with different mutational types. METHODS: ERS tolerance, reflected by apoptosis and cell viability, was detected in human oligodendrocyte cell line transfected with the wild type, or different mutations of p. Arg113His, p. Arg269FNx01 or p. Ser610-Asp613del in eIF2Bε. A representative UPR-PERK component of activating transcription factor 4 (ATF4) was measured under the basal condition and ERS induction. Autophagy was analyzed the flux in the presence of lysosomal inhibitors. RESULTS: The degree of ERS tolerance varied in different genotypes. The truncated or deletion mutant showed prominent apoptosis cell viability declination after ERS induction. The most seriously damaged GEF activity of p. Arg269FNx01 group underwent spontaneous apoptosis. The truncated or deletion mutant showed elevated ATF4 under basal as well as ERS condition. Decreased expression of LC3-I and LC3-II in the mutants reflected an impaired autophagy flux, which was more obvious in the truncated or deletion mutants after ERS induction. CONCLUSIONS: GEF activities in different genotypes could influence the cell ERS tolerance as well as compensatory pathways of UPR and autophagy. Oligodendrocytes with truncated or deletion mutants showed less tolerable to ERS.


Sujet(s)
Facteur-2B d'initiation eucaryote/génétique , Oligodendroglie/métabolisme , Lignée cellulaire , Stress du réticulum endoplasmique/génétique , Stress du réticulum endoplasmique/physiologie , Humains , Mutation/génétique , Réponse aux protéines mal repliées/génétique , Réponse aux protéines mal repliées/physiologie
17.
Zhonghua Nei Ke Za Zhi ; 51(3): 201-5, 2012 Mar.
Article de Chinois | MEDLINE | ID: mdl-22781893

RÉSUMÉ

OBJECTIVE: To analyze the stroke subtypes and influencing factors in four largest economic regions of China. METHODS: We analyzed the investigation data of QUEST (Quality Evaluation of Stroke Care and Treatment) study conducted in 2006 which included 62 hospitals in a national scale. According to the concept of four economic regions designed by the Development Research Center of the State Council, we performed the univariate and multivariate analysis for the stroke subtypes and its related risk factors in the different economic regions. RESULTS: There were 3362 (73.5%) ischemic stroke patients and 1214 (26.5%) hemorrhagic stroke patients among the total 4576 first-ever stroke patients. Comparison of stroke subtypes in the four different economic regions was statistically significant (P < 0.001), with a percentage of 80.8% ischemic stroke patients in the northeastern region, 78.9% in the eastern region, 68.3% in the central region and 67.0% in the western region. The comparisons of risk factors such as history of hypertension, diabetes, hyperlipidaemia, coronary artery event, atrial fibrillation, and overweight in the four different economic regions were also statistically significant (P < 0.05). CONCLUSIONS: The subtypes of first-ever stroke vary in the four largest economic regions with a highest proportion of ischemic stroke in the northeastern region and relatively high proportion of hemorrhagic stroke in the central and western economic regions. There are also discrepancies of stroke risk factors in the different economic regions.


Sujet(s)
Accident vasculaire cérébral/épidémiologie , Encéphalopathie ischémique/épidémiologie , Hémorragie cérébrale/épidémiologie , Chine/épidémiologie , Femelle , Humains , Mâle , Adulte d'âge moyen , Études prospectives , Facteurs de risque
18.
Dalton Trans ; 41(8): 2289-95, 2012 Feb 28.
Article de Anglais | MEDLINE | ID: mdl-22180866

RÉSUMÉ

Diallylmelamine combines with Ag(2)O and auxiliary polycarboxylates to give three stable crystalline network structures, namely, [Ag(2)(dama)(2)(nipt)·H(2)O·C(2)H(5)OH](n) (1), [Ag(2)(dama)(glu)](n) (2), and [Ag(4)(dama)(2)(pma)·2H(2)O](n) (3), (dama = diallylmelamine, H(2)nipt = 5-nitroisophthalic acid, H(2)glu = glutaric acid, H(4)pma = pyromellitic acid), which have been successfully synthesized and characterized by elemental analysis, FT-IR Spectra, powder X-ray diffraction and thermogravimetric analyses, and single-crystal X-ray diffraction. Complex 1 is a 1D double-chain extended by µ(2)-N,N'-(η(2)-vinyl)-dama and µ(3)-nipt along the b axis. Notably, dama ligands in 1 display two coordination modes (bidentate µ(2)-N,N'-(η(2)-vinyl) and monodentate µ(1)-N) and two different conformations (cis(anti-gauche) and trans(anti-anti)). In 2, a pair of centrosymmetric glu ligands clamp two Ag(I) ions to form a half paddle-wheel [Ag(2)(COO)(2)] secondary building unit (SBU) which is further extended by µ(2)-N,N'-(η(2)-vinyl)-dama to form a 1D tape. Complex 3 is a 2D sheet built from µ(3)-N,N',N''-(η(2)-vinyl)-dama and µ(8)-pma. Interestingly, apparent silver-vinyl interactions with a η(2) mode were commonly observed in the solid-state structures of 1-3 (Ag-C = 2.311(4)-2.467(5) Å). The structural dissimilarity between 1 and 2 is caused by the different auxiliary polycarboxylates and different coordination modes of dama. In addition, the thermal stabilities and emissive behaviors of them were also investigated.

19.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 19(4): 884-9, 2011 Aug.
Article de Chinois | MEDLINE | ID: mdl-21867607

RÉSUMÉ

The study was aimed to investigate the effect of quercetin, flavonoid molecules on reversing leukemia multidrug resistance and its mechanism. K562/A cells were cultured in vitro with different concentrations of quercetin. Cell growth inhibition and adriamycin (ADR) sensitivity were detected by MTT method. Intracellular ADR concentration was determined by flow cytometry. Cell apoptosis was assayed by Annexin V/PI staining method. The expressions of drug transporter and apoptosis related genes were measured by real-time PCR array. The results indicated that quercetin inhibited the proliferation of K562 and K562/A in 5-160 µmol/L and with dose-dependent manner. Quercetin increased the sensitivity of K562/A cells to ADR in a low toxicity concentration. Flow cytometry showed that the quercetin increased the accumulation of ADR in K562/A cells when cells were co-cultured with 5 µmol/L ADR for 2 hours. Quercetin could induce the apoptosis of K562 and K562/A cells with dose dependent manner. Furthermore, some drug transport related genes such as ATP-binding cassette (ABC) and solute carrier (SLC) and some apoptosis-related genes such as BCL-2, tumor necrosis factor (TNF), tumor necrosis factor receptor (TNFR) families were down-regulated by quercetin. It is concluded that quercetin reverses MDR of leukemic cells by multiple mechanisms and the reversing effect is positively related to drug concentration.


Sujet(s)
Multirésistance aux médicaments/effets des médicaments et des substances chimiques , Résistance aux médicaments antinéoplasiques/effets des médicaments et des substances chimiques , Quercétine/pharmacologie , Humains , Cellules K562
20.
Dalton Trans ; 40(21): 5677-9, 2011 Jun 07.
Article de Anglais | MEDLINE | ID: mdl-21512687

RÉSUMÉ

An ultrasonic reaction of Ag(2)O, 4,4'-bipyridine (bipy) and (2S, 3R)-3-amino-2-hydroxybutanoic acid (L-Thr) gives an unexpected Ag(I) supramolecular framework, {[Ag(3)(bipy)(3)(cahba)]·HCO(3)·10H(2)O}(n) (1), in which the (2S, 3R)-3-(carboxyamino)-2-hydroxybutanoic acid (H(2)cahba) is a carbamate derivative of L-Thr, obtained via in situ transformation of amino group of L-Thr into carbamate by means of CO(2) uptake.


Sujet(s)
Carbamates/composition chimique , Dioxyde de carbone/composition chimique , Oxydes/composition chimique , Composés de l'argent/composition chimique , Thréonine/composition chimique , Pyridines/composition chimique , Stéréoisomérie , Science des ultrasons
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