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1.
Nature ; 554(7692): 341-345, 2018 02 14.
Artigo em Inglês | MEDLINE | ID: mdl-29446382

RESUMO

The honeycomb lattice is one of the simplest lattice structures. Electrons and spins on this simple lattice, however, often form exotic phases with non-trivial excitations. Massless Dirac fermions can emerge out of itinerant electrons, as demonstrated experimentally in graphene, and a topological quantum spin liquid with exotic quasiparticles can be realized in spin-1/2 magnets, as proposed theoretically in the Kitaev model. The quantum spin liquid is a long-sought exotic state of matter, in which interacting spins remain quantum-disordered without spontaneous symmetry breaking. The Kitaev model describes one example of a quantum spin liquid, and can be solved exactly by introducing two types of Majorana fermion. Realizing a Kitaev model in the laboratory, however, remains a challenge in materials science. Mott insulators with a honeycomb lattice of spin-orbital-entangled pseudospin-1/2 moments have been proposed, including the 5d-electron systems α-Na2IrO3 (ref. 5) and α-Li2IrO3 (ref. 6) and the 4d-electron system α-RuCl3 (ref. 7). However, these candidates were found to magnetically order rather than form a liquid at sufficiently low temperatures, owing to non-Kitaev interactions. Here we report a quantum-liquid state of pseudospin-1/2 moments in the 5d-electron honeycomb compound H3LiIr2O6. This iridate does not display magnetic ordering down to 0.05 kelvin, despite an interaction energy of about 100 kelvin. We observe signatures of low-energy fermionic excitations that originate from a small number of spin defects in the nuclear-magnetic-resonance relaxation and the specific heat. We therefore conclude that H3LiIr2O6 is a quantum spin liquid. This result opens the door to finding exotic quasiparticles in a strongly spin-orbit-coupled 5d-electron transition-metal oxide.

2.
Org Biomol Chem ; 20(3): 619-629, 2022 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-34940771

RESUMO

We report the synthesis of seven-membered iminosugars derived from a 3S-acetamido-4R,5R,6S-trihydroxyazepane scaffold and their evaluation as inhibitors of functionally related exo-N-acetylhexosaminidases including human O-GlcNAcase (OGA), human lysosomal ß-hexosaminidase (HexAB), and Escherichia coli NagZ. Capitalizing on the flexibility of azepanes and the active site tolerances of hexosaminidases, we explore the effects of epimerization of stereocenters at C-3, C-5 and C-6 and C-alkylation at the C-2 or C-7 positions. Accordingly, epimerization at C-6 (L-ido) and at C-5 (D-galacto) led to selective HexAB inhibitors whereas introduction of a propyl group at C-7 on the C-3 epimer furnished a potent NagZ inhibitor.


Assuntos
Acetilglucosaminidase/antagonistas & inibidores , Inibidores Enzimáticos/farmacologia , Imino Açúcares/farmacologia , beta-N-Acetil-Hexosaminidases/antagonistas & inibidores , Acetilglucosaminidase/metabolismo , Alquilação , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Escherichia coli/enzimologia , Humanos , Imino Açúcares/síntese química , Imino Açúcares/química , Conformação Molecular , beta-N-Acetil-Hexosaminidases/metabolismo
3.
Tech Coloproctol ; 25(2): 223-227, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33459968

RESUMO

BACKGROUND: Complete mesocolic excision with central vessel ligation may be important for accurate staging and improving the prognosis of right-sided colon cancer. Although the procedure is often performed laparoscopically, approaching the middle colic artery (MCA) is technically demanding, especially when complete ligation of arteries at their roots is desired. We standardized our laparoscopic approach by establishing the dissection boundary along the superior mesenteric artery to achieve D3 lymphadenectomy in the region of the MCA. The aim of the present study was to evaluate, on the basis of perioperative and short-term oncologic outcomes, the feasibility and safety of our technique METHODS: We conducted a retrospective study on consecutive patients with cancer located at the ascending colon and transverse colon who had laparoscopic right hemicolectomy requiring ligation of the MCA. RESULTS: There were 41 patients (22 males, median age 71 years [range 49-86] years). The median operation time was 285 min, and blood loss volume was 40 mL. Conversion to open surgery was required in 1 case. Complications that were Clavien-Dindo grade III or above occurred in 3 patients (7.3%). There was no anastomotic leakage. The median number of lymph nodes harvested was 46. CONCLUSIONS: Our technique was shown to be a safe, feasible, and useful strategy for performance of right hemicolectomy requiring ligation of the MCA in cases of colon cancer. The technique facilitates maximal lymph node dissection. Having obtained favorable outcomes, we look forward to investigation into long-term outcomes.


Assuntos
Neoplasias do Colo , Laparoscopia , Mesocolo , Idoso , Idoso de 80 Anos ou mais , Colectomia , Neoplasias do Colo/cirurgia , Humanos , Ligadura , Excisão de Linfonodo , Masculino , Artéria Mesentérica Inferior/cirurgia , Artéria Mesentérica Superior , Mesocolo/cirurgia , Pessoa de Meia-Idade , Estudos Retrospectivos
4.
Int Endod J ; 52(6): 908-916, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30688377

RESUMO

AIM: To compare the shaping ability of four instrumentation systems in curved molar root canals, using computerized microtomography (micro-CT). METHODOLOGY: Forty mesial roots of mandibular molars were submitted first to radiographic examination to determine their curvature and then to a micro-CT scan to analyse other initial morphological characteristics. The specimens were distributed into four experimental groups, according to the endodontic instrumentation system used (n = 10): Group R, Reciproc; Group PTN, ProTaper Next; Group WOG, WaveOne Gold; Group PDL, ProDesign Logic. After root canal instrumentation, the specimens were submitted to a second micro-CT scan, and the pre- and postoperative data were examined to evaluate the following parameters: volume of dentine removed (DR), increase in root canal volume (VI), untouched root canal surface area (UA), volume of accumulated hard tissue debris (AD) and structure model index (SMI). The data observed for these parameters after instrumentation were analysed using generalized linear models. R software was used for the analyses, and the level of significance adopted was 5%. RESULTS: There were no significant differences among the instrumentation systems regarding the DR, VI, UA and AD parameters (P > 0.05). PTN and WOG systems were associated with greater increases in SMI than the PDL system (P < 0.05). CONCLUSIONS: The four systems evaluated were similar regarding the parameters analysed, with the exception of the SMI, with the rate of variation of this parameter being greater after using the PTN and WOG systems than after using the PDL system. These results indicate that the four systems perform similarly in terms of their shaping ability, but that the PTN and WOG systems produced more rounded preparations than the PDL system.


Assuntos
Cavidade Pulpar , Preparo de Canal Radicular , Instrumentos Odontológicos , Dente Molar , Microtomografia por Raio-X
5.
Clin Exp Allergy ; 48(5): 544-554, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29431874

RESUMO

BACKGROUND: Chronic rhinosinusitis (CRS) is a heterogeneous chronic inflammatory disease generally divided based on the presence or absence of nasal polyps (NPs). One of the features of NPs is excessive fibrin deposition, which is associated with down-regulation of tissue plasminogen activator (t-PA) in NPs. As t-PA is expressed in epithelial cells, and epithelium is readily accessible to topical therapies, identifying compounds that can mediate the induction of t-PA would be a potential new strategy for the treatment of NPs. OBJECTIVE: The objective of this study was to determine whether short-chain fatty acids (SCFAs) can induce t-PA in airway epithelial cells via their known receptors GPR41 and GPR43. METHODS: We performed immunohistochemistry (IHC) to determine whether receptors for SCFAs, known as G protein-coupled receptor 41/free fatty acid receptor 3 (GPR41/FFAR3) and GPR43/FFAR2, are expressed in nasal tissue. Primary normal human bronchial epithelial (NHBE) cells were stimulated with different concentrations of SCFAs to test induction of t-PA, which was analysed by expression of mRNA and protein. Mediation of responses by SCFA receptors was evaluated by specific receptor gene silencing with siRNA. RESULTS: Immunohistochemistry study revealed that airway epithelial cells expressed GPR41 and GPR43. Acetic acid, propionic acid, butyric acid and valeric acid significantly induced t-PA expression from two- to tenfolds. The strongest inducer of t-PA from NHBE cells was propionic acid; cells stimulated with propionic acid released t-PA into the supernatant in its active form. Gene silencing of GPR41 and GPR43 revealed that induction of t-PA by SCFAs was dependent upon both GPR41 and GPR43. CONCLUSIONS AND CLINICAL RELEVANCE: Short-chain fatty acids were shown to induce airway epithelial cell expression of t-PA via GPR41 and GPR43. Topical delivery of potent compounds that activate these receptors may have value by reducing fibrin deposition and shrinking nasal polyp growth.


Assuntos
Ácidos Graxos Voláteis/farmacologia , Receptores de Superfície Celular/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Mucosa Respiratória/efeitos dos fármacos , Ativador de Plasminogênio Tecidual/biossíntese , Adulto , Células Cultivadas , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pólipos Nasais/metabolismo , Mucosa Respiratória/metabolismo , Ativador de Plasminogênio Tecidual/efeitos dos fármacos
6.
Hum Reprod ; 33(7): 1228-1236, 2018 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-29684118

RESUMO

STUDY QUESTION: Does spontaneous endometriosis in cynomolgus monkeys have the characteristics required of a good experimental model? SUMMARY ANSWER: Spontaneous endometriosis in cynomolgus monkeys exhibited similar clinicopathological characteristics to the human disease and was useful as an experimental model. WHAT IS KNOWN ALREADY: The prevalence of endometriosis in autopsied cynomolgus monkeys (Macaca fascicularis) in a breeding colony was reported to be 28.7% in 1993. The histopathological findings we reported recently showed that components of spontaneous endometriosis were not only endometriotic epithelium and stromal cells (CD10-positive) with hemorrhage and inflammation, but also smooth muscle metaplasia and nerve fibers. STUDY DESIGN, SIZE, DURATION: During routine medical examinations at a research facility from 2008 to 2012, 614 female cynomolgus monkeys of reproductive age (6-25 years) were screened for endometriosis by the presence of regular menstrual bleeding, serum CA125 levels and palpation of the abdomen. In total, 29 monkeys were selected as subjects for the following study. PARTICIPANTS/MATERIALS, SETTING, METHODS: Of the 29 monkeys selected, 15 were diagnosed with endometriosis by laparoscopy and/or open surgery. The monkeys were monitored by observing their general condition, and eight of these were monitored using laparoscopy and MRI. In addition, to investigate appropriate screening parameters and endometriosis-associated biological parameters in monkeys, we retrospectively examined general laboratory parameters that correlate to the menstrual cycle and disease status. MAIN RESULTS AND THE ROLE OF CHANCE: The combination of CA125 serum levels (this was a useful marker for chocolate cysts), palpation of the abdomen, and fecal abnormalities was the most efficient screening method for diagnosing monkeys with endometriosis. Each animal could be diagnosed and assigned a disease stage by laparoscopy. While monitoring the disease stage by laparoscopy and/or MRI, disease status in individual monkeys was mainly stable or was progressive for 2-7 months. The detection rate by screening was low (15/614) but age-specific analysis suggests that screening would be more efficient if a colony for an endometriosis model is maintained with 11-20-year olds. As an endometriosis-associated biological parameter, the decrease in food consumption that coincided with menstruation was selected and correlated well (R2 value = 0.8239) with disease status (according to a modified adhesion revised American Fertility Society score). LARGE SCALE DATA: N/A. LIMITATIONS, REASONS FOR CAUTION: Peritoneal fluid was not analyzed because a smaller amount is produced in cynomolgus monkeys than in baboons. Although clinical endometriosis-associated pain is evaluated in women using a visual analog scale, pain could not be directly evaluated in this non-human primate model. WIDER IMPLICATIONS OF THE FINDINGS: Although cynomolgus monkeys are relatively small (2-5 kg) primates, laparoscopy and MRI make it possible to evaluate spontaneous endometriosis in these monkeys and to monitor its development over time. Spontaneous endometriosis in cynomolgus monkeys is a useful model for evaluating disease progress and drug efficacy because they have similar lesions to those in humans, and conventional laboratory methods and parameters for assessment are well established. STUDY FUNDING/COMPETING INTEREST(S): No external funds were used for this study. A.N.-K., K.T., H.T., A.K. and M.S. are full-time employees of Chugai Pharmaceutical Co., Ltd. R.K. received a consultancy fee from Chugai Pharmaceutical Co., Ltd. and lecture fees from Chugai Pharmaceuticals, Japan Vaccine Co. Ltd., Merck & Co., Mochida Co. Ltd., Roche Diagnostics, and BD, unrelated to the submitted work. S.N., S.O. and T.S. have nothing to declare.


Assuntos
Modelos Animais de Doenças , Endometriose/patologia , Animais , Líquido Ascítico/patologia , Feminino , Macaca fascicularis , Estudos Retrospectivos , Células Estromais/patologia
7.
Clin Exp Allergy ; 47(4): 457-466, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28000955

RESUMO

BACKGROUND: B cells play many roles in health and disease. However, little is known about the mechanisms that drive B cell responses in the airways, especially in humans. Chronic rhinosinusitis (CRS) is an inflammatory disease of the upper airways that affects 10% of Europeans and Americans. A subset of CRS patients develop nasal polyps (NPs), which are characterized by type 2 inflammation, eosinophils and group 2 innate lymphoid cells (ILC2s). We have reported that NP contain elevated levels of B cells and antibodies, making NP an ideal system for studying B cells in the airways. OBJECTIVE: We sought to determine the mechanisms that drive B cell activation and antibody production during chronic airway inflammation. METHODS: We analysed B cells from NP or tonsil, or after ILC2 coculture, by flow cytometry. Antibody production from tissue was measured using Luminex assays and the frequency of antibody-secreting cells by ELISpot. Formation of B cell clusters was assessed using immunohistochemistry. Expression of genes associated with B cell activation and class switch recombination was measured by qRT-PCR. RESULTS: NP contained significantly elevated frequencies of plasmablasts, especially those that expressed the extrafollicular marker Epstein-Barr virus-induced protein 2 (EBI2), but significantly fewer germinal centre (GC) B cells compared with tonsil. Antibody production and the frequency of antibody-secreting cells were significantly elevated in NP, and there was evidence for local class switch recombination in NP. Finally, ILC2s directly induced EBI2 expression on B cells in vitro. CONCLUSIONS AND CLINICAL RELEVANCE: Our data suggest there is a unique B cell activation environment within NP that is distinct from classic GC-mediated mechanisms. We show for the first time that ILC2s directly induce EBI2 expression on B cells, indicating that ILC2s may play an important role in B cell responses. B cell-targeted therapies may provide new treatment options for CRSwNP.


Assuntos
Formação de Anticorpos/imunologia , Linfócitos B/imunologia , Inflamação/imunologia , Ativação Linfocitária/imunologia , Doenças Respiratórias/imunologia , Subpopulações de Linfócitos B/imunologia , Subpopulações de Linfócitos B/metabolismo , Linfócitos B/metabolismo , Biomarcadores , Expressão Gênica , Humanos , Imunofenotipagem , Inflamação/metabolismo , Inflamação/patologia , Contagem de Linfócitos , Pólipos Nasais/imunologia , Pólipos Nasais/metabolismo , Pólipos Nasais/patologia , Plasmócitos/imunologia , Plasmócitos/metabolismo , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismo , Doenças Respiratórias/metabolismo , Doenças Respiratórias/patologia
8.
Org Biomol Chem ; 15(21): 4609-4619, 2017 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-28513749

RESUMO

The synthesis of a series of d-gluco-like configured 4,5,6-trihydroxyazepanes bearing a triazole, a sulfonamide or a fluorinated acetamide moiety at C-3 is described. These synthetic derivatives have been tested for their ability to selectively inhibit the muropeptide recycling glucosaminidase NagZ and to thereby increase sensitivity of Pseudomonas aeruginosa to ß-lactams, a pathway with substantial therapeutic potential. While introduction of triazole and sulfamide groups failed to lead to glucosaminidase inhibitors, the NHCOCF3 analog proved to be a selective inhibitor of NagZ over other glucosaminidases including human O-GlcNAcase and lysosomal hexosaminidases HexA and B.


Assuntos
Antibacterianos/farmacologia , Azepinas/química , Azepinas/farmacologia , Glicosídeo Hidrolases/antagonistas & inibidores , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/enzimologia , beta-Lactamas/farmacologia , Azepinas/síntese química , Azepinas/metabolismo , Ceftazidima/farmacologia , Sinergismo Farmacológico , Glicosídeo Hidrolases/química , Glicosídeo Hidrolases/metabolismo , Hidroxilação , Simulação de Acoplamento Molecular , Conformação Proteica
9.
Hum Reprod ; 31(10): 2352-9, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27591226

RESUMO

STUDY QUESTION: What are the characteristics of spontaneous endometriosis in cynomolgus monkeys? SUMMARY ANSWER: Spontaneous endometriosis in cynomolgus monkeys exhibited similar characteristics to the human disease. WHAT IS KNOWN ALREADY: One previous report described the prevalence and the basic histopathology of spontaneous endometriosis in cynomolgus monkeys. STUDY DESIGN, SIZE, DURATION: Endometriotic lesions that had been histologically confirmed in 8 female cynomolgus monkeys between 5 and 21 years old were subjected to study. PARTICIPANTS/MATERIALS, SETTING, METHODS: The monkeys died of, or were sacrificed because of, sickness consequent on endometriosis. Specimens were evaluated histopathologically with haematoxylin and eosin staining, iron staining and immunohistochemistry (CD10, CD31, α-SMA and PGP9.5), and by observing them under a microscope. MAIN RESULTS AND THE ROLE OF CHANCE: Endometriotic and stromal cells (CD10-positive) with haemorrhage and inflammation were observed. Smooth muscle metaplasia and nerve fibres were also noted in the endometriotic lesions. Endometriotic lesions in lymph nodes were incidentally found. LIMITATIONS AND REASONS FOR CAUTION: Since laparoscopic analysis for monitoring the disease state was not set as a parameter of the current study, time course changes (progression) of the disease were not assessed. WIDER IMPLICATIONS OF THE FINDINGS: Further investigation of spontaneous endometriosis in cynomolgus monkeys may contribute to better understanding of the disease pathobiology. STUDY FUNDING/COMPETING INTERESTS: No external funds were used for this study. A.N.K., S.M., S.H., T.I., O.K., A.K. and M.S. are full-time employees of Chugai Pharmaceutical Co., Ltd. R.K. received lecture fees from Chugai Pharmaceutical Co., Ltd., unrelated to the submitted work. S.N., S. O., L.Y., K.Y. and T.S. have nothing to declare. TRIAL REGISTRATION NUMBER: N/A.


Assuntos
Endometriose/patologia , Endométrio/patologia , Doenças Ovarianas/patologia , Células Estromais/patologia , Animais , Proliferação de Células , Feminino , Fibrose/patologia , Linfonodos/patologia , Macaca fascicularis
10.
Org Biomol Chem ; 14(44): 10371-10385, 2016 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-27735004

RESUMO

This paper explores the computer modelling aided design and synthesis of ß-N-acetylhexosaminidase inhibitors along with their applicability to human disease treatment through biological evaluation in both an enzymatic and cellular setting. We investigated the importance of individual stereocenters, variations in structure-activity relationships along with factors influencing cell penetration. To achieve these goals we modified nitrogen heterocycles in terms of ring size, side chains present and ring nitrogen derivatization. By reducing the inhibitor interactions with the active site down to the essentials we were able to determine that besides the established 2S,3R trans-relationship, the presence and stereochemistry of the CH2OH side chain is of crucial importance for activity. In terms of cellular penetration, N-butyl side chains favour cellar uptake, while hydroxy- and carboxy-group bearing sidechains on the ring nitrogen retarded cellular penetration. Furthermore we show an early proof of principle study that ß-N-acetylhexosaminidase inhibitors can be applicable to use in a potential anti-invasive anti-cancer strategy.

11.
J Periodontal Res ; 51(6): 758-767, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27870141

RESUMO

BACKGROUND AND OBJECTIVE: Nanoparticle bioceramics are being investigated for biomedical applications. We fabricated a regenerative scaffold comprising type I collagen and beta-tricalcium phosphate (ß-TCP) nanoparticles. Fibroblast growth factor-2 (FGF-2) is a bioeffective signaling molecule that stimulates cell proliferation and wound healing. This study examined the effects, on bioactivity, of a nano-ß-TCP/collagen scaffold loaded with FGF-2, particularly on periodontal tissue wound healing. MATERIAL AND METHODS: Beta-tricalcium phosphate was pulverized into nanosize particles (84 nm) and was then dispersed. A nano-ß-TCP scaffold was prepared by coating the surface of a collagen scaffold with a nanosize ß-TCP dispersion. Scaffolds were characterized using scanning electron microscopy, compressive testing, cell seeding and rat subcutaneous implant testing. Then, nano-ß-TCP scaffold, nano-ß-TCP scaffold loaded with FGF-2 and noncoated collagen scaffold were implanted into a dog one-wall infrabony defect model. Histological observations were made at 10 d and 4 wk postsurgery. RESULTS: Scanning electron microscopy images show that TCP nanoparticles were attached to collagen fibers. The nano-ß-TCP scaffold showed higher compressive strength and cytocompatibility compared with the noncoated collagen scaffold. Rat subcutaneous implant tests showed that the DNA contents of infiltrating cells in the nano-ß-TCP scaffold and the FGF-2-loaded scaffold were approximately 2.8-fold and 3.7-fold greater, respectively, than in the collagen scaffold. Histological samples from the periodontal defect model showed about five-fold greater periodontal tissue repair following implantation of the nano-ß-TCP scaffold loaded with FGF-2 compared with the collagen scaffold. CONCLUSION: The ß-TCP nanoparticle coating strongly improved the collagen scaffold bioactivity. Nano-ß-TCP scaffolds containing FGF-2 are anticipated for use in periodontal tissue engineering.


Assuntos
Fosfatos de Cálcio/uso terapêutico , Fator 2 de Crescimento de Fibroblastos/uso terapêutico , Nanopartículas/uso terapêutico , Periodonto/crescimento & desenvolvimento , Engenharia Tecidual/métodos , Alicerces Teciduais , Animais , Materiais Biocompatíveis/uso terapêutico , Colágeno Tipo I/uso terapêutico , Cães , Feminino , Masculino , Microscopia Eletrônica de Varredura , Periodonto/ultraestrutura , Ratos , Ratos Wistar , Cicatrização
12.
Clin Exp Allergy ; 45(2): 384-93, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25469646

RESUMO

BACKGROUND: Although chronic rhinosinusitis with nasal polyps (CRSwNP) is characterized by Th2 inflammation, the mechanism underlying the onset and amplification of this inflammation has not been fully elucidated. Dendritic cells (DCs) are major antigen-presenting cells, central inducers of adaptive immunity and critical regulators of many inflammatory diseases. However, the presence of DCs in CRS, especially in nasal polyps (NPs), has not been extensively studied. OBJECTIVE: The objective of this study was to characterize DC subsets in CRS. METHODS: We used real-time PCR to assess the expression of mRNA for markers of myeloid DCs (mDCs; CD1c), plasmacytoid DCs (pDCs; CD303) and Langerhans cells (LCs; CD1a, CD207) in uncinate tissue (UT) from controls and patients with CRS as well as in NP. We assayed the presence of DCs by immunohistochemistry and flow cytometry. RESULTS: Compared to UT from control subjects (n = 15) and patients with CRS without NP (CRSsNP) (n = 16) and CRSwNP (n = 17), mRNAs for CD1a and CD1c were significantly elevated in NPs (n = 29). In contrast, CD207 mRNA was not elevated in NPs. Immunohistochemistry showed that CD1c(+) cells but not CD303(+) cells were significantly elevated in NPs compared to control subjects or patients with CRSsNP. Flow cytometric analysis showed that CD1a(+) cells in NPs might be a subset of mDC1s and that CD45(+) CD19(-) CD1c(+) CD11c(+) CD141(-) CD303(-) HLA-DR(+) mDC1s and CD45(+) CD19(-) CD11c(+) CD1c(-) CD141(high) HLA-DR(+) mDC2s were significantly elevated in NPs compared to UT from controls and CRSsNP, but CD45(+) CD11c(-) CD303(+) HLA-DR(+) pDCs were only elevated in NPs compared to control UT. CONCLUSION AND CLINICAL RELEVANCE: Myeloid DCs are elevated in CRSwNP, especially in NPs. Myeloid DCs thus may indirectly contribute to the inflammation observed in CRSwNP.


Assuntos
Células Dendríticas/imunologia , Células Mieloides/imunologia , Pólipos Nasais/imunologia , Rinite/imunologia , Sinusite/imunologia , Adulto , Idoso , Antígenos de Superfície/genética , Antígenos de Superfície/metabolismo , Biomarcadores , Doença Crônica , Células Dendríticas/metabolismo , Feminino , Humanos , Imuno-Histoquímica , Imunofenotipagem , Masculino , Pessoa de Meia-Idade , Células Mieloides/metabolismo , Pólipos Nasais/complicações , Pólipos Nasais/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Rinite/complicações , Rinite/metabolismo , Sinusite/complicações , Sinusite/metabolismo , Células Th2/imunologia , Células Th2/metabolismo , Adulto Jovem
13.
Phys Rev Lett ; 114(7): 077202, 2015 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-25763972

RESUMO

A complex iridium oxide ß-Li(2)IrO(3) crystallizes in a hyperhoneycomb structure, a three-dimensional analogue of honeycomb lattice, and is found to be a spin-orbital Mott insulator with J(eff)=1/2 moment. Ir ions are connected to the three neighboring Ir ions via Ir-O(2)-Ir bonding planes, which very likely gives rise to bond-dependent ferromagnetic interactions between the J(eff)=1/2 moments, an essential ingredient of Kitaev model with a spin liquid ground state. Dominant ferromagnetic interaction between J(eff)=1/2 moments is indeed confirmed by the temperature dependence of magnetic susceptibility χ(T) which shows a positive Curie-Weiss temperature θ(CW)∼+40 K. A magnetic ordering with a very small entropy change, likely associated with a noncollinear arrangement of J(eff)=1/2 moments, is observed at T(c)=38 K. With the application of magnetic field to the ordered state, a large moment of more than 0.35 µ(B)/Ir is induced above 3 T, a substantially polarized J(eff)=1/2 state. We argue that the close proximity to ferromagnetism and the presence of large fluctuations evidence that the ground state of hyperhoneycomb ß-Li(2)IrO(3) is located in close proximity of a Kitaev spin liquid.

14.
Org Biomol Chem ; 13(43): 10734-44, 2015 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-26356422

RESUMO

The synthesis of eleven 1-deoxynojirimycin (DNJ) derivatives presenting either a monofluoro, difluoro, thiolated or unsaturated N-alkyl chain of various length is described. Exploiting the unsaturated moiety on the nitrogen, fluorine has been introduced through a HF/SbF5 superacid catalysed hydrofluorination and thiol-ene click chemistry allowed introduction of sulfur. The synthetic derivatives have been tested for their ability to inhibit glycosidases and correct F508del-CFTR. Two of the unsaturated iminosugars exhibited potency similar to Miglustat as F508del-CFTR correctors. The thioalkyl iminosugars as well as the corresponding alkyl iminosugars demonstrated low micromolar α-glucosidases and trehalases inhibition. Introduction of fluorine abolished F508del-CFTR correction and trehalase inhibition.


Assuntos
1-Desoxinojirimicina/análogos & derivados , Regulador de Condutância Transmembrana em Fibrose Cística/genética , Inibidores Enzimáticos/química , Inibidores de Glicosídeo Hidrolases/química , Trealase/antagonistas & inibidores , 1-Desoxinojirimicina/farmacologia , Animais , Regulador de Condutância Transmembrana em Fibrose Cística/metabolismo , Inibidores Enzimáticos/farmacologia , Inibidores de Glicosídeo Hidrolases/farmacologia , Halogenação , Humanos , Insetos , Mutação , Compostos de Sulfidrila/química , Compostos de Sulfidrila/farmacologia , Suínos , Trealase/metabolismo , alfa-Glucosidases/metabolismo
15.
Org Biomol Chem ; 13(11): 3446-56, 2015 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-25666467

RESUMO

A series of pentahydroxylated pyrrolidines, displaying five contiguous stereogenic centres and epimeric to α-glucosidase inhibitor homoDMDP, have been synthesized. The key step involves a γ-aminoalcohol rearrangement applied to polyhydroxylated azepanes. These five-membered iminosugars demonstrate micromolar inhibition of glycosidases.


Assuntos
Amino Álcoois/química , Azepinas/química , Inibidores de Glicosídeo Hidrolases/síntese química , Manitol/análogos & derivados , Pirrolidinas/síntese química , Inibidores de Glicosídeo Hidrolases/química , Inibidores de Glicosídeo Hidrolases/farmacologia , Imino Piranoses/síntese química , Imino Piranoses/química , Imino Piranoses/farmacologia , Manitol/síntese química , Manitol/química , Manitol/farmacologia , Estrutura Molecular , Pirrolidinas/química , Relação Estrutura-Atividade , alfa-Glucosidases/metabolismo
16.
Org Biomol Chem ; 12(44): 8977-96, 2014 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-25277226

RESUMO

The glycosidase inhibitory properties of synthetic C-alkyl and N-alkyl six-membered iminosugars have been extensively studied leading to therapeutic candidates. The related seven-membered iminocyclitols have been less examined despite the report of promising structures. Using an in house ring enlargement/C-alkylation as well as cross-metathesis methodologies as the key steps, we have undertaken the synthesis and biological evaluation of a library of fourteen 2C- and eight N-alkyl tetrahydroxylated azepanes starting from an easily available glucopyranose-derived azidolactol. Four, six, nine and twelve carbon atom alkyl chains have been introduced. The study of two distinct D-gluco and L-ido stereochemistries for the tetrol pattern as well as R and S configurations for the C-2 carbon bearing the C-alkyl chain is reported. We observed that C-alkylation of the L-ido tetrahydroxylated azepane converts it from an α-L-fucosidase to a ß-glucosidase and ß-galactosidase inhibitor while N-alkylation of the D-gluco iminosugar significantly improves its inhibition profile leading to potent ß-glucosidase, ß-galactosidase, α-L-rhamnosidase and ß-glucuronidase inhibitors whatever the stereochemistry of the alkyl chain. Interestingly, the N-alkyl chain length usually parallels the azepane inhibitor potency as exemplified by the identification of a potent glucocerebrosidase inhibitor (Ki 1 µM) bearing a twelve carbon atom chain. Additionally, several C-alkyl azepanes demonstrated promising F508del-CFTR correction unlike the parent tetrahydroxyazepanes. None of the C-alkyl and N-alkyl azepanes did inhibit ER α-glucosidases I or II.


Assuntos
Regulador de Condutância Transmembrana em Fibrose Cística/antagonistas & inibidores , Inibidores Enzimáticos/farmacologia , Glucosilceramidase/antagonistas & inibidores , Imino Açúcares/farmacologia , Alquilação , Cristalografia por Raios X , Regulador de Condutância Transmembrana em Fibrose Cística/genética , Regulador de Condutância Transmembrana em Fibrose Cística/metabolismo , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Glucosilceramidase/metabolismo , Humanos , Imino Açúcares/síntese química , Imino Açúcares/química , Modelos Moleculares , Conformação Molecular , Relação Estrutura-Atividade
17.
Int Endod J ; 47(11): 1012-33, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24483229

RESUMO

The C-shaped root canal constitutes an unusual root morphology that can be found primarily in mandibular second permanent molars. Due to the complexity of their structure, C-shaped root canal systems may complicate endodontic interventions. A thorough understanding of root canal morphology is therefore imperative for proper diagnosis and successful treatment. This review aims to summarize current knowledge regarding C-shaped roots and root canals, from basic morphology to advanced endodontic procedures. To this end, a systematic search was conducted using the MEDLINE, BIOSIS, Cochrane Library, EMBASE, Google Scholar, Web of Science, PLoS and BioMed Central databases, and many rarely cited articles were included. Furthermore, four interactive 3D models of extracted teeth are introduced that will allow for a better understanding of the complex C-shaped root canal morphology. In addition, the present publication includes an embedded best-practice video showing an exemplary root canal procedure on a tooth with a pronounced C-shaped root canal. The survey of this unusual structure concludes with a number of suggestions concerning future research efforts.


Assuntos
Cavidade Pulpar/anormalidades , Tratamento do Canal Radicular , Humanos , Incidência
18.
Br J Surg ; 100(4): 522-7, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23288577

RESUMO

BACKGROUND: Postoperative chylous ascites following abdominal surgery is uncommon. It potentially induces malnutrition and immunodeficiency, contributing to increased mortality. In the field of hepatopancreatobiliary (HPB) surgery, no large studies have been conducted that focused on postoperative chylous ascites. The aim of this study was to determine the incidence, risk factors and management of chylous ascites following HPB surgery, with particular emphasis on pancreatic resection. METHODS: Consecutive patients who had HPB surgery between 2000 and 2011 at a single institution were reviewed retrospectively. Chyle leak was defined as 100 ml/day or more of milky, amylase-free peritoneal fluid with a triglyceride concentration of 110 mg/dl or above. Risk factors for chylous ascites associated with pancreatic resection and the clinical efficacy of octreotide in treating chylous ascites were evaluated. RESULTS: Of 2002 consecutive patients who underwent HPB surgery during the study period, 21 (1·0 per cent) developed chylous ascites. Chylous ascites occurred relatively frequently in patients who had a pancreatic resection, such as pancreaticoduodenectomy (3·3 per cent) or distal pancreatectomy (3·8 per cent). Multivariable analysis revealed that manipulation of the para-aortic area (P < 0·001), retroperitoneal invasion (P = 0·031) and early enteral feeding after operation (P < 0·001) were independent risk factors for chylous ascites following pancreatic resection. Octreotide treatment decreased drainage output of chylous ascites on day 1 after initiation of treatment (P = 0·002). CONCLUSION: Chylous ascites is a rare complication following HPB surgery. It is more common after pancreatic resection. Treatment with octreotide combined with total parenteral nutrition is recommended.


Assuntos
Doenças Biliares/cirurgia , Procedimentos Cirúrgicos do Sistema Biliar , Ascite Quilosa/etiologia , Pâncreas/cirurgia , Pancreatopatias/cirurgia , Complicações Pós-Operatórias/etiologia , Ascite Quilosa/tratamento farmacológico , Feminino , Fármacos Gastrointestinais/uso terapêutico , Humanos , Masculino , Pessoa de Meia-Idade , Octreotida/uso terapêutico , Pancreatectomia , Pancreaticoduodenectomia , Complicações Pós-Operatórias/tratamento farmacológico , Estudos Retrospectivos , Fatores de Risco
19.
Allergy ; 67(1): 25-32, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21899560

RESUMO

BACKGROUND: Chronic rhinosinusitis (CRS) is a heterogeneous disease characterized by local inflammation of the upper airways and sinuses and is frequently divided into polypoid CRS (CRSwNP) and nonpolypoid CRS (CRSsNP). However, the mechanism of inflammation in CRS has still not been fully elucidated. The aim of the study was to investigate the role of interleukin-32 (IL-32), a recently discovered proinflammatory cytokine, in CRS. METHODS: We collected nasal epithelial cells and nasal tissue from patients with CRS and control subjects. We assayed mRNA for IL-32 by real-time PCR and measured IL-32 protein using ELISA, Western blot, and immunohistochemistry. RESULTS: The expression of mRNA for IL-32 was elevated in epithelial cells from uncinate tissue from patients with CRSsNP compared with patients with CRSwNP (P < 0.05), control subjects (P=0.06), and epithelial cells from nasal polyp (NP) tissue (P < 0.05). Production of IL-32 was induced by IFN-γ, TNF, and dsRNA in primary airway epithelial cells. In whole-tissue extracts, the expression of IL-32 protein was significantly elevated in patients with CRSwNP compared with patients with CRSsNP and control subjects. Immunohistochemistry data showed that IL-32 was detected in mucosal epithelial cells and inflammatory cells in the lamina propria. Levels of IL-32 were correlated with the levels of CD3 and macrophage mannose receptor in NP tissue. Immunofluorescence data showed IL-32 co-localization with CD3-positive T cells and CD68-positive macrophages in NPs. CONCLUSION: Overproduction of IL-32 may be involved in the pathogenesis of CRS, although the role of IL-32 in the inflammation in CRSsNP and CRSwNP may be different.


Assuntos
Interleucinas/biossíntese , Pólipos Nasais/metabolismo , Rinite/metabolismo , Sinusite/metabolismo , Adolescente , Adulto , Idoso , Doença Crônica , Feminino , Humanos , Interleucinas/análise , Macrófagos/imunologia , Macrófagos/metabolismo , Masculino , Pessoa de Meia-Idade , Pólipos Nasais/complicações , Pólipos Nasais/imunologia , RNA Mensageiro/análise , Rinite/complicações , Rinite/imunologia , Sinusite/complicações , Sinusite/imunologia , Linfócitos T/imunologia , Linfócitos T/metabolismo , Adulto Jovem
20.
Allergy ; 67(7): 920-8, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22676062

RESUMO

BACKGROUND: Chronic rhinosinusitis (CRS) is a disease characterized by inflammation of the nasal mucosa and paranasal sinuses. This inflammation may result in part from decreased epithelial barrier and innate immune responses, leading to frequent bacterial and fungal colonization. The objectives of this study were to investigate the expression of innate immune proteins of the palate lung and nasal epithelium clone (PLUNC) family in patients with CRS. METHODS: Nasal tissue samples were collected from control subjects and CRS patients with and without nasal polyps. Expression of the members of the PLUNC family was analyzed by real-time PCR. Expression of SPLUNC1 and LPLUNC2 proteins was analyzed by ELISA, immunoblot, and immunohistochemical analysis. RESULTS: Levels of mRNA for most of the members of the PLUNC family were profoundly reduced in nasal polyps (NPs) compared to uncinate tissue from control subjects or patients with CRS. LPLUNC2 and SPLUNC1 proteins were decreased in NPs of patients with CRS compared to uncinate tissue from control subjects. Immunohistochemical data revealed that within submucosal glands of sinonasal tissues, SPLUNC1 and LPLUNC2 were differentially expressed, in serous and mucous cells, respectively. The decrease in the expression of these molecules is probably explained by a decrease in the number of glands in NPs as revealed by correlations with levels of the glandular marker lactoferrin. CONCLUSIONS: Decreased SPLUNC1 and LPLUNC2 in NPs reflect a profound decrease in the number of submucosal glands. Decreased glands may lead to a localized defect in the production and release of glandular innate defense molecules.


Assuntos
Expressão Gênica , Glicoproteínas/genética , Pólipos Nasais/genética , Fosfoproteínas/genética , Rinite/genética , Sinusite/genética , Adolescente , Adulto , Idoso , Doença Crônica , Feminino , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Glicoproteínas/imunologia , Humanos , Lactoferrina/genética , Lactoferrina/imunologia , Masculino , Pessoa de Meia-Idade , Mucosa Nasal/imunologia , Mucosa Nasal/metabolismo , Pólipos Nasais/imunologia , Fosfoproteínas/imunologia , Rinite/imunologia , Sinusite/imunologia , Adulto Jovem
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