RESUMO
Understanding the competition between superconductivity and other ordered states (such as antiferromagnetic or charge-density-wave (CDW) state) is a central issue in condensed matter physics. The recently discovered layered kagome metal AV3Sb5 (A = K, Rb, and Cs) provides us a new playground to study the interplay of superconductivity and CDW state by involving nontrivial topology of band structures. Here, we conduct high-pressure electrical transport and magnetic susceptibility measurements to study CsV3Sb5 with the highest Tc of 2.7 K in AV3Sb5 family. While the CDW transition is monotonically suppressed by pressure, superconductivity is enhanced with increasing pressure up to P1 ≈ 0.7 GPa, then an unexpected suppression on superconductivity happens until pressure around 1.1 GPa, after that, Tc is enhanced with increasing pressure again. The CDW is completely suppressed at a critical pressure P2 ≈ 2 GPa together with a maximum Tc of about 8 K. In contrast to a common dome-like behavior, the pressure-dependent Tc shows an unexpected double-peak behavior. The unusual suppression of Tc at P1 is concomitant with the rapidly damping of quantum oscillations, sudden enhancement of the residual resistivity and rapid decrease of magnetoresistance. Our discoveries indicate an unusual competition between superconductivity and CDW state in pressurized kagome lattice.
RESUMO
In this study, we investigated the association between the interleukin (IL)-10 -592C/A, -819C/T, and -1082G/A genetic variations and susceptibility to diabetic nephropathy in a Chinese population. The IL-10 -592C/A, -819C/T, and -1082G/A polymorphisms were genotyped in diabetic nephropathy patient and control samples by polymerase chain reaction-restriction fragment length polymorphism. The results were then statistically analyzed using SPSS 17.0. The results of the χ(2) test revealed a significant difference in the frequencies of the GG, GA, and AA genotypes of IL-10 -1082G/A between patients with diabetic nephropathy and control subjects (χ(2) = 10.03, P = 0.007). Unconditional logistic regression analysis revealed that the AA genotype of IL-10 -1082G/A significantly increased the susceptibility to diabetic nephropathy [adjusted odds ratio (OR) = 2.52, 95% confidence interval (CI) = 1.31-4.82] compared to the wild-type genotype. Moreover, the A allele of this polymorphism was associated with an increased risk of diabetic nephropathy compared to the G allele (adjusted OR = 1.51, 95%CI = 1.15-1.99). However, the IL-10 -819T/C and -592A/C genetic polymorphisms did not increase the risk of diabetic nephropathy. In conclusion, the IL-10 -1082G/A polymorphism was found to be correlated with the development of diabetic nephropathy.
Assuntos
Povo Asiático/genética , Nefropatias Diabéticas/genética , Interleucina-10/genética , Adulto , Idoso , Alelos , China , Diabetes Mellitus Tipo 2/genética , Feminino , Frequência do Gene , Predisposição Genética para Doença , Variação Genética , Humanos , Masculino , Pessoa de Meia-Idade , Razão de Chances , Polimorfismo de Nucleotídeo ÚnicoRESUMO
PURPOSE: To access the feasibility of using cultivated oral mucosal epithelial cell transplantation (COMET) for the management of severe corneal burn. METHODS: COMET was performed to promote re-epithelialization in two eyes with acute alkaline burn and one eye with chronic alkaline burn, and to reconstruct the ocular surface in two eyes with chronic thermal burn. Autologous oral mucosal epithelial cells obtained from biopsy were cultivated on amniotic membrane. Immunoconfocal microscopy for keratins and progenitor cell markers was performed to characterize the cultivated epithelial sheet. Following transplantation, the clinical outcome and possible complications were documented. The patients were followed for an averaged 29.6+/-3.6 (range: 26-34) months. RESULTS: Cultivated oral mucosal epithelial sheet expressed keratin 3, 13, and progenitor cell markers p63, p75, and ABCG2. After COMET, all the corneas became less inflamed, and the corneal surface was completely re-epithelialized in 6.0+/-3.2 (range: 3-10) days in all but one patients. Microperforation occurred in one patient, and a small persistent epithelial defect developed in another. Both were solved uneventfully. In all patients, superficial corneal blood vessels invariably developed, and to further improve vision, conjunctivo-limbal autografting (N=3) and/or penetrating keratoplasty (N=3) were performed subsequently. The vision of all patients showed substantial improvement after additional surgeries. CONCLUSIONS: This study showed the potential of COMET to promote re-epithelialization and reduce inflammation in acute corneal burn, and to reconstruct the corneal surface in chronic burn. COMET may, therefore, be considered an alternative treatment for severe corneal burn.
Assuntos
Transplante de Células , Lesões da Córnea , Células Epiteliais/transplante , Queimaduras Oculares/cirurgia , Mucosa Bucal/citologia , Adolescente , Adulto , Âmnio/transplante , Biomarcadores/metabolismo , Queimaduras Químicas/cirurgia , Técnicas de Cultura de Células/métodos , Células Cultivadas , Células Epiteliais/metabolismo , Epitélio Corneano/patologia , Epitélio Corneano/cirurgia , Queimaduras Oculares/patologia , Estudos de Viabilidade , Humanos , Queratinas/metabolismo , Masculino , Pessoa de Meia-Idade , Engenharia Tecidual/métodos , Transplante Autólogo , Adulto JovemRESUMO
Primary spontaneous pneumothorax (PSP) is a common manifestation of Birt-Hogg-Dubé syndrome caused by folliculin gene (FLCN) mutation, which is also found in isolated familial PSP cases. A complete genetic analysis of FLCN was performed in 102 unrelated Chinese patients with isolated PSP and 21 of their family members. Three novel mutations (c.924_926del, c.1611_1631del and c.1740C>T) and a previously reported mutation (c.1733insC) were identified in five familial and five sporadic PSP patients. Of the 21 family members of patients with PSP including 3 previous considered as sporadic, 4 (19%) had history of at least one episode of PSP and 9 (43%) were FLCN mutant carriers without PSP. Seven of the nine (78%) mutant carriers had pulmonary cysts detected by high-resolution computed tomography (HRCT). Although c.924_926del and c.1611_1631del were found in eight patients from the same geographic district, haplotype analysis demonstrated that they did not share the same affected haplotype, thus excluding common ancestry. This study first demonstrates that FLCN mutation contributes to not only familial but also 'apparently sporadic' patients with isolated PSP. It suggests that mutation analysis and HRCT scan may be recommended for first-degree family members of PSP patients with FLCN mutations, irrespective of their family history status of PSP.
Assuntos
Mutação , Pneumotórax/genética , Proteínas Proto-Oncogênicas/genética , Proteínas Supressoras de Tumor/genética , Adolescente , Adulto , Idoso , Estudos de Casos e Controles , China/epidemiologia , Cistos , Análise Mutacional de DNA , Saúde da Família , Feminino , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , SíndromeRESUMO
PURPOSE: Matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinase (TIMPs) have been linked to the angiogenic process in general. In order to understand the potential roles of MMP-2, MMP-9 and TIMPs in the corneal neovascularization process, we examined the expression and activities of MMP-2, MMP-9 and TIMPs during the course of cauterization-induced corneal neovascularization in a rat model. METHODS: Neovascularization of rat corneas was induced by silver nitrate cauterization. The expression of MMP-2, MMP-9, TIMP-1 and TIMP-2 was examined by immunohistochemistry and RT-PCR. The protein activities of MMPs and TIMPs were compared in pre- and postcauterization corneas by gelatin zymography and reverse zymography, respectively. RESULTS: MMP-2, TIMP-1 and TIMP-2 immunoreactivities were expressed in normal corneas, predominantly in the corneal epithelium. After injury, immunoreactivities of both MMPs and TIMPs were increased, notably in the healing corneal epithelium, infiltrating inflammatory cells, stromal fibroblasts and ingrowing vascular endothelial cells. The increase in gross MMP-2 enzymatic activity paralleled the maximal vascular ingrowth on day 4, while the gross MMP-9 enzymatic activity rose immediately on day 1, then decreased steadily, which paralleled the magnitude of inflammatory cell infiltration. The immunoreactivity of MMPs/TIMPs decreased significantly 2 weeks after cauterization. On day 35, MMP-2, TIMP-1 and TIMP-2 staining was seen only in corneal epithelium and vascular endothelial cells. Both the RT-PCR and reverse zymography results revealed a more constant expression of TIMP-2, while the TIMP-1 expression appeared to be more inducible. CONCLUSION: MMPs as well as TIMPs were upregulated in cauterization-induced corneal neovascularization, suggesting that both may participate in extracellular matrix remodeling in the corneal wound healing, inflammation and neovascularization processes.
Assuntos
Neovascularização da Córnea/enzimologia , Metaloproteinase 2 da Matriz/biossíntese , Metaloproteinase 9 da Matriz/biossíntese , Inibidor Tecidual de Metaloproteinase-1/biossíntese , Inibidor Tecidual de Metaloproteinase-2/biossíntese , Animais , Neovascularização da Córnea/induzido quimicamente , Neovascularização da Córnea/patologia , Feminino , Técnicas Imunoenzimáticas , Metaloproteinase 2 da Matriz/genética , Metaloproteinase 9 da Matriz/genética , Modelos Animais , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-Dawley , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Nitrato de Prata , Inibidor Tecidual de Metaloproteinase-1/genética , Inibidor Tecidual de Metaloproteinase-2/genéticaAssuntos
Neovascularização de Coroide/etiologia , Ceratomileuse Assistida por Excimer Laser In Situ/efeitos adversos , Adulto , Neovascularização de Coroide/diagnóstico , Córnea/cirurgia , Angiofluoresceinografia , Humanos , Verde de Indocianina , Masculino , Miopia/cirurgia , Hemorragia Retiniana/diagnóstico , Hemorragia Retiniana/etiologiaRESUMO
AIM: To study the efficacy and safety of amniotic membrane graft as an adjunctive therapy after removal of primary pterygium, and to compare the clinical outcome with conjunctival autograft and topical mitomycin C. METHODS: 80 eyes of 71 patients with primary pterygia were treated with excision followed by amniotic membrane graft. The result was compared retrospectively with 56 eyes of 50 patients receiving conjunctival autograft, and 54 eyes of 46 patients receiving topical mitomycin C. Patients were followed for at least 6 months, and the averaged follow up periods for the three groups were 13.8, 22.8, and 18.4 months, respectively. RESULTS: There were three recurrences (3.8%) in the amniotic membrane graft group, three recurrences (5.4%) in the conjunctival autograft group, and two recurrences (3.7%) in the topical mitomycin C group. There was no significant difference in recurrence rate among the three groups (p = 0.879). No major complications occurred in the amniotic membrane graft group or the conjunctival autograft group. One case of infectious scleritis due to scleral ischaemia occurred in the topical mitomycin C group. CONCLUSION: This study showed that amniotic membrane graft was as effective as conjunctival autograft and mitomycin C in preventing pterygium recurrence, and can be considered as a preferred grafting procedure for primary pterygium.
Assuntos
Âmnio/transplante , Antibióticos Antineoplásicos/administração & dosagem , Mitomicina/administração & dosagem , Pterígio/cirurgia , Administração Tópica , Adulto , Idoso , Idoso de 80 Anos ou mais , Análise de Variância , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pterígio/tratamento farmacológico , Estudos Retrospectivos , Prevenção Secundária , Transplante Autólogo , Resultado do TratamentoRESUMO
PURPOSE: To identify the potential antiangiogenic and antiinflammatory proteins expressed in human amniotic membrane tissue. METHODS: Human amniotic epithelial and mesenchymal cells were isolated from human amniotic membranes by sequential trypsin and collagenase digestion. Total RNAs were harvested from freshly obtained human amniotic epithelial and mesenchymal cells. Antiangiogenic and antiinflammatory proteins were detected by the reverse transcriptase-polymerase chain reaction (RT-PCR) technique and further confirmed by DNA sequencing of PCR-amplified transcripts. The distribution of tissue inhibitors of metalloproteinase (TIMPs) were studied further by immunohistochemistry performed on paraffin-embedded amniotic membrane tissue. RESULTS: RT-PCR results showed that both human amniotic epithelial and mesenchymal cells express interleukin-1 receptor antagonist, all four TIMPs, collagen XVIII, and interleukin-10. Thrombospondin-1 was expressed in all of the epithelial cell specimens and in one out of five mesenchymal cell specimens. Furthermore, immunohistochemistry studies performed on freshly prepared amniotic membrane confirmed that all members of the TIMP family were present in epithelial and mesenchymal cells as well as in the compact layer of the amniotic stroma. In cryopreserved amniotic membranes, positive staining was seen in residual amniotic cells and stroma. CONCLUSIONS: Human amniotic membrane epithelial and mesenchymal cells express various antiangiogenic and antiinflammatory proteins. Some of those proteins also were found in amniotic membrane stroma. These findings may explain in part the antiangiogenic and antiinflammatory effects of amniotic membrane transplantation.
Assuntos
Âmnio/química , Colágeno/análise , Interleucina-10/análise , Sialoglicoproteínas/análise , Trombospondina 1/análise , Inibidores Teciduais de Metaloproteinases/análise , Separação Celular , Colágeno/genética , Primers do DNA/química , Células Epiteliais/química , Expressão Gênica , Humanos , Técnicas Imunoenzimáticas , Proteína Antagonista do Receptor de Interleucina 1 , Interleucina-10/genética , Mesoderma/química , RNA/isolamento & purificação , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise de Sequência de DNA , Sialoglicoproteínas/genética , Inibidores Teciduais de Metaloproteinases/genéticaRESUMO
The putative prophylactic and therapeutic effect of interferon-beta (IFN-beta) on autoimmune inflammation of the peripheral nervous system was evaluated in experimental autoimmune neuritis (EAN), a well-known animal model of the human Guillain-Barré syndrome (GBS). We report that treatment of rats with 300,000 U of recombinant rat IFN-beta (rrIFN-beta) given every other day starting at the day of immunization prevented clinical signs of EAN. When treatment was started at the onset of disease development, the cytokine clearly ameliorated EAN. Both B- and T-cell responses towards peripheral myelin were suppressed by the IFN-beta, and immunohistochemical analyses revealed a strong decrease in the numbers of infiltrating CD4(+) T cells, macrophages, and other inflammatory cells as well as a significant reduction in MHC class II antigen expression and monocyte chemotactic protein-1 (MCP-1) production, which induces chemotaxis and chemokinesis of leukocytes from blood. It is concluded that the observed suppression of EAN by rrIFN-beta is associated with a decrease in the migration of inflammatory cells into peripheral nervous tissue.
Assuntos
Adjuvantes Imunológicos/uso terapêutico , Inibição de Migração Celular , Interferon beta/uso terapêutico , Interferon gama/metabolismo , Neurite Autoimune Experimental/tratamento farmacológico , Fator de Crescimento Transformador beta/metabolismo , Adjuvantes Imunológicos/farmacologia , Animais , Quimiocina CCL2/metabolismo , Feminino , Interferon beta/farmacologia , Interferon gama/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Neurite Autoimune Experimental/metabolismo , Ratos , Ratos Endogâmicos Lew , Nervo Isquiático/efeitos dos fármacos , Nervo Isquiático/metabolismo , Linfócitos T/efeitos dos fármacos , Linfócitos T/metabolismo , Fator de Crescimento Transformador beta/efeitos dos fármacosRESUMO
PURPOSE: To study the in vitro angiogenic activity of human conjunctival and limbal epithelial cells and conjunctival, limbal, and corneal fibroblasts in a three-cell-type coculture model. METHODS: Human umbilical vein endothelial cells (EC) were cocultured with epithelial cells, fibroblasts, or epithelial cells and fibroblasts to test their effect on EC morphogenesis. Neutralizing antibodies to some known angiogenic factors were added to the culture to see whether the EC morphogenesis may be blocked by a particular antibody. RESULTS: Conjunctival and limbal epithelial cells exhibited very little or no stimulatory effect on EC tube formation when examined in an EC- epithelial cell coculture system. In contrast, conjunctival, limbal, and corneal fibroblasts all promoted EC morphogenesis when examined under the same culture conditions. Fibroblast-induced EC morphogenesis was inhibited by addition of anti-vascular endothelial growth factor (VEGF) and/or anti-basic fibroblast growth factor (bFGF) antibodies to the culture medium. In the three-cell-type coculture system consisting of ECs, fibroblasts, and epithelial cells, limbal epithelial cells (but not conjunctival epithelial cells) exhibited a strong inhibitory effect on fibroblast-induced EC tube formation. CONCLUSIONS: The proangiogenic activity of ocular surface fibroblasts is probably mediated through a paracrine mechanism by VEGF and bFGF. Limbal epithelial cells, but not conjunctival epithelial cells, inhibit fibroblast-stimulated angiogenesis.
Assuntos
Endotélio Vascular/citologia , Células Epiteliais/fisiologia , Adolescente , Adulto , Idoso , Diferenciação Celular , Células Cultivadas , Criança , Pré-Escolar , Técnicas de Cocultura , Túnica Conjuntiva/citologia , Córnea/citologia , Fatores de Crescimento Endotelial/farmacologia , Fator 2 de Crescimento de Fibroblastos/farmacologia , Fibroblastos/fisiologia , Humanos , Limbo da Córnea/citologia , Linfocinas/farmacologia , Pessoa de Meia-Idade , Morfogênese , Neovascularização Fisiológica/efeitos dos fármacos , Comunicação Parácrina , Veias Umbilicais/citologia , Fator A de Crescimento do Endotélio Vascular , Fatores de Crescimento do Endotélio VascularRESUMO
Experimental autoimmune neuritis (EAN) is an autoimmune inflammatory demyelinating disease of the peripheral nervous system (PNS), and represents an animal model of the human Guillain-Barré syndrome (GBS). In this study, we report that nasal administration of the neuritogenic peptide 180-199 and of the cryptic peptide 56-71 of the rat neuritogenic P0 protein of peripheral nerve myelin prevents EAN and attenuates ongoing EAN. Both peptides effectively decreased the severity and shortened clinical EAN. Both a prophylactic and a therapeutic approach proved to be beneficial. These effects were associated with T and B cells hyporesponsiveness to the peptide antigens, reflected by downregulated Th1 cell responses (interferon-gamma secretion) and macrophage function, whereas Th2 cell responses (IL-4 secretion) and transforming growth factor-beta mRNA expression were upregulated.