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1.
Proc Natl Acad Sci U S A ; 121(1): e2303423120, 2024 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-38150501

RESUMO

The ability to efficiently control charge and spin in the cuprate high-temperature superconductors is crucial for fundamental research and underpins technological development. Here, we explore the tunability of magnetism, superconductivity, and crystal structure in the stripe phase of the cuprate La[Formula: see text]Ba[Formula: see text]CuO[Formula: see text], with [Formula: see text] = 0.115 and 0.135, by employing temperature-dependent (down to 400 mK) muon-spin rotation and AC susceptibility, as well as X-ray scattering experiments under compressive uniaxial stress in the CuO[Formula: see text] plane. A sixfold increase of the three-dimensional (3D) superconducting critical temperature [Formula: see text] and a full recovery of the 3D phase coherence is observed in both samples with the application of extremely low uniaxial stress of [Formula: see text]0.1 GPa. This finding demonstrates the removal of the well-known 1/8-anomaly of cuprates by uniaxial stress. On the other hand, the spin-stripe order temperature as well as the magnetic fraction at 400 mK show only a modest decrease under stress. Moreover, the onset temperatures of 3D superconductivity and spin-stripe order are very similar in the large stress regime. However, strain produces an inhomogeneous suppression of the spin-stripe order at elevated temperatures. Namely, a substantial decrease of the magnetic volume fraction and a full suppression of the low-temperature tetragonal structure is found under stress, which is a necessary condition for the development of the 3D superconducting phase with optimal [Formula: see text]. Our results evidence a remarkable cooperation between the long-range static spin-stripe order and the underlying crystalline order with the three-dimensional fully coherent superconductivity. Overall, these results suggest that the stripe- and the SC order may have a common physical mechanism.

2.
Phys Rev Lett ; 125(9): 097005, 2020 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-32915617

RESUMO

We report muon spin rotation and magnetic susceptibility experiments on in-plane stress effects on the static spin-stripe order and superconductivity in the cuprate system La_{2-x}Ba_{x}CuO_{4} with x=0.115. An extremely low uniaxial stress of ∼0.1 GPa induces a substantial decrease in the magnetic volume fraction and a dramatic rise in the onset of 3D superconductivity, from ∼10 to 32 K; however, the onset of at-least-2D superconductivity is much less sensitive to stress. These results show not only that large-volume-fraction spin-stripe order is anticorrelated with 3D superconducting coherence but also that these states are energetically very finely balanced. Moreover, the onset temperatures of 3D superconductivity and spin-stripe order are very similar in the large stress regime. These results strongly suggest a similar pairing mechanism for spin-stripe order and the spatially modulated 2D and uniform 3D superconducting orders, imposing an important constraint on theoretical models.

3.
Phys Rev Lett ; 124(18): 187002, 2020 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-32441965

RESUMO

We use resonant inelastic x-ray scattering to investigate charge-stripe correlations in La_{1.675}Eu_{0.2}Sr_{0.125}CuO_{4}. By differentiating elastic from inelastic scattering, it is demonstrated that charge-stripe correlations precede both the structural low-temperature tetragonal phase and the transport-defined pseudogap onset. The scattering peak amplitude from charge stripes decays approximately as T^{-2} towards our detection limit. The in-plane integrated intensity, however, remains roughly temperature independent. Therefore, although the incommensurability shows a remarkably large increase at high temperature, our results are interpreted via a single scattering constituent. In fact, direct comparison to other stripe-ordered compounds (La_{1.875}Ba_{0.125}CuO_{4}, La_{1.475}Nd_{0.4}Sr_{0.125}CuO_{4}, and La_{1.875}Sr_{0.125}CuO_{4}) suggests a roughly constant integrated scattering intensity across all these compounds. Our results therefore provide a unifying picture for the charge-stripe ordering in La-based cuprates. As charge correlations in La_{1.675}Eu_{0.2}Sr_{0.125}CuO_{4} extend beyond the low-temperature tetragonal and pseudogap phase, their emergence heralds a spontaneous symmetry breaking in this compound.

4.
Public Health ; 174: 18-21, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31301551

RESUMO

OBJECTIVES: To describe the health information preferences in middle-aged Japanese workers based on health literacy (HL) levels and presence of medications. STUDY DESIGN: A cross-sectional study. METHODS: We performed a web-based questionnaire survey with Japanese workers aged below 60 years. HL was assessed using the total score of communicative skills (five items) and critical skills (four items) from the 14-item Health Literacy Scale. Regarding their health information preferences, participants were asked about the health information they wanted (four items), could easily understand (six items), or easily use (two items) and answered on a 4-point scale (strongly agree/agree/disagree/strongly disagree). The percentages of the affirmative responses (strongly agree or agree) were compared among tertiles based on the HL score. RESULTS: We obtained data from a total of 3387 volunteers, of whom 510 participants were on either antihypertensive, lipid-lowering, or antidiabetic drugs. Compared with the high HL and middle HL groups, low HL had fewer affirmative responses to most health information items. Health information items received 70% of affirmative responses even in the low HL level. They were visually shown by figures or pictures, highlighted by colors for important points, could be read in 1-2 min, and were accessed on the Internet, regardless of the presence of medications. Additionally, the explanation for mechanisms of medications or lifestyle to prevent or improve diseases showed high affinity in all HL levels, only for those on medications. CONCLUSIONS: This result generates a hypothesis that low HL individuals have a low interest in health information. Our data showed several possible forms of health information with high affinity based on HL levels that would help plan future population approaches.


Assuntos
Comportamento do Consumidor/estatística & dados numéricos , Informação de Saúde ao Consumidor , Letramento em Saúde/estatística & dados numéricos , Adulto , Estudos Transversais , Emprego/estatística & dados numéricos , Feminino , Humanos , Internet , Japão , Masculino , Pessoa de Meia-Idade , Doenças não Transmissíveis/prevenção & controle , Inquéritos e Questionários
5.
Phys Rev Lett ; 115(10): 102501, 2015 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-26382672

RESUMO

Differential cross sections of isoscalar and isovector spin-M1 (0(+)→1(+)) transitions are measured using high-energy-resolution proton inelastic scattering at E(p)=295 MeV on (24)Mg, (28)Si, (32)S, and (36)Ar at 0°-14°. The squared spin-M1 nuclear transition matrix elements are deduced from the measured differential cross sections by applying empirically determined unit cross sections based on the assumption of isospin symmetry. The ratios of the squared nuclear matrix elements accumulated up to E(x)=16 MeV compared to a shell-model prediction are 1.01(9) for isoscalar and 0.61(6) for isovector spin-M1 transitions, respectively. Thus, no quenching is observed for isoscalar spin-M1 transitions, while the matrix elements for isovector spin-M1 transitions are quenched by an amount comparable with the analogous Gamow-Teller transitions on those target nuclei.

6.
Surg Today ; 45(8): 986-92, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25156007

RESUMO

PURPOSE: To estimate the feasibility and limitations of incomplete cytoreductive surgery and modern systemic chemotherapy in patients with synchronous peritoneal carcinomatosis from colorectal cancer and to identify risk factors for death and factors associated with the patient prognosis. METHODS: Sixty-five consecutive patients underwent surgery for synchronous peritoneal carcinomatosis from colorectal cancer at Hiroshima University, Japan between 1992 and 2012. The clinical, histological, and survival data were analyzed for independent risk factors and prognostic factors. The patients were retrospectively stratified into two groups according to the extent of surgery: complete cytoreductive surgery or incomplete cytoreductive surgery. RESULTS: The median survival times in the complete and incomplete cytoreductive surgery groups were 29.8 and 10.0 months, respectively. Receiving systemic chemotherapy alone was an independent risk factor for death in the incomplete cytoreductive surgery group (P < 0.001). Oxaliplatin and molecular-targeted drug (cetuximab or bevacizumab) therapies were also independent prognostic factors (P < 0.001), whereas irinotecan therapy was not a prognostic factor (P = 0.494). CONCLUSION: Oxaliplatin and molecular-targeted drug therapies improved the overall survival in patients undergoing incomplete cytoreductive surgery. Future trials for patients with synchronous peritoneal carcinomatosis from colorectal cancer should be undertaken, with patients stratified according to treatment with complete cytoreductive surgery or incomplete cytoreductive surgery with modern chemotherapy.


Assuntos
Antineoplásicos/uso terapêutico , Neoplasias Colorretais/terapia , Procedimentos Cirúrgicos de Citorredução/métodos , Terapia de Alvo Molecular , Neoplasias Primárias Múltiplas , Compostos Organoplatínicos/uso terapêutico , Neoplasias Peritoneais/terapia , Idoso , Neoplasias Colorretais/mortalidade , Terapia Combinada , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Oxaliplatina , Neoplasias Peritoneais/mortalidade , Prognóstico , Estudos Retrospectivos , Taxa de Sobrevida
7.
Phys Rev Lett ; 112(11): 112502, 2014 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-24702355

RESUMO

Gamow-Teller (GT) transitions in atomic nuclei are sensitive to both nuclear shell structure and effective residual interactions. The nuclear GT excitations were studied for the mass number A = 42, 46, 50, and 54 "f-shell" nuclei in ((3)He, t) charge-exchange reactions. In the (42)Ca → (42)Sc reaction, most of the GT strength is concentrated in the lowest excited state at 0.6 MeV, suggesting the existence of a low-energy GT phonon excitation. As A increases, a high-energy GT phonon excitation develops in the 6-11 MeV region. In the (54)Fe → (54)Co reaction, the high-energy GT phonon excitation mainly carries the GT strength. The existence of these two GT phonon excitations are attributed to the 2 fermionic degrees of freedom in nuclei.

8.
Mol Cell Neurosci ; 52: 97-105, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23085039

RESUMO

Cyclin-dependent kinase 5 (Cdk5) is a serine/threonine kinase, and its kinase activity is dependent upon its association with either of the activating subunits p35 or p39, which are mainly expressed in neurons. We previously reported that Cdk5 knockout (KO) mice exhibit perinatal lethality, defective neuronal migration, and abnormal positioning of neurons in the facial motor nucleus and inferior olive in the hindbrain and Purkinje cells (PCs) in the cerebellum. In this study, we focused on the analysis of the role of Cdk5 in cerebellar development. For this purpose we generated midbrain-hindbrain-specific Cdk5 conditional knockout (MHB-Cdk5 KO) mice because the cerebellum develops postnatally, whereas Cdk5 KO mice die perinatally. Histological analysis of the MHB-Cdk5 KO mice revealed a significant size reduction of the cerebellum. In addition, profound disturbance of inward migration of granule cells (GC) was observed in the developing cerebellum. A normal dendritic development of the Purkinje cells (PCs) was disturbed in MHB-Cdk5 KO mice. Cultured Cdk5-null PCs showed similar dendritic abnormalities. These results indicate that Cdk5/p35 plays an important role in neuronal migration of PCs and GCs and dendrite formation of PCs in cerebellar development.


Assuntos
Movimento Celular/fisiologia , Cerebelo/enzimologia , Cerebelo/crescimento & desenvolvimento , Quinase 5 Dependente de Ciclina/metabolismo , Dendritos/ultraestrutura , Neurogênese/fisiologia , Animais , Western Blotting , Cerebelo/embriologia , Hibridização In Situ , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout
9.
Rev Sci Instrum ; 94(1): 013906, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36725613

RESUMO

We present an in situ uniaxial pressure device optimized for small angle x-ray and neutron scattering experiments at low-temperatures and high magnetic fields. A stepper motor generates force, which is transmitted to the sample via a rod with an integrated transducer that continuously monitors the force. The device has been designed to generate forces up to 200 N in both compressive and tensile configurations, and a feedback control allows operating the system in a continuous-pressure mode as the temperature is changed. The uniaxial pressure device can be used for various instruments and multiple cryostats through simple and exchangeable adapters. It is compatible with multiple sample holders, which can be easily changed depending on the sample properties and the desired experiment and allow rapid sample changes.

10.
J Oral Rehabil ; 39(6): 399-404, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22115393

RESUMO

The objectives of this study were to quantitatively evaluate the gender differences in the lip-closing force (LCF) generated during pursing-like lip-closing movement using a multidirectional LCF measurement system in healthy young adults. In 40 healthy subjects (20 women, 20 men; median age = 26·5 years, range = 22-41 years), LCF was recorded in eight directions during the performance of a voluntary pursing-like lip-closing task in four measurement sessions. The correlations between the total sum of the forces generated in all eight directions [total LCF (TLCF)] and each directional LCF (DLCF) and those between opposing DLCF were statistically analysed. The TLCF obtained from the highly reproducible measurements acquired in the four different sessions was normally distributed in both genders. The TLCF in men was significantly greater than that in women. Among the eight pairs of opposing DLCF, seven pairs of opposing DLCF showed significant correlations in men, while five pairs were significantly correlated in women. In men, no significant difference was observed between opposing DLCF; however, three pairs of opposing DLCF were significantly different in women. The present results quantitatively indicate that there are gender differences in the magnitude and directional specificity of the LCF produced during pursing-like lip-closing movement in healthy young adults.


Assuntos
Expressão Facial , Músculos Faciais/fisiologia , Lábio/fisiologia , Movimento/fisiologia , Adulto , Feminino , Humanos , Masculino , Fatores Sexuais , Adulto Jovem
11.
Phys Rev Lett ; 107(12): 127002, 2011 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-22026791

RESUMO

We demonstrated experimentally a direct way to probe a hidden propensity to the formation of a spin-density wave in a nonmagnetic metal with strong Fermi surface nesting. Substituting Fe for a tiny amount of Cu (1%) induced an incommensurate magnetic order below 20 K in heavily overdoped La(2-x)Sr(x)CuO(4). Elastic neutron scattering suggested that this order cannot be ascribed to the localized spins on Cu or doped Fe. Angle-resolved photoemission revealed a strong Fermi surface nesting inherent in the pristine La(2-x)Sr(x)CuO(4) that likely drives this order. Our finding presents the first example of the long-sought "itinerant-spin extreme" of cuprates, where the spins of itinerant doped holes define the magnetic ordering ground state; it complements the current picture of cuprate spin physics that highlights the predominant role of localized spins at lower dopings.

12.
Phys Rev Lett ; 107(6): 062502, 2011 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-21902316

RESUMO

A benchmark experiment on (208)Pb shows that polarized proton inelastic scattering at very forward angles including 0° is a powerful tool for high-resolution studies of electric dipole (E1) and spin magnetic dipole (M1) modes in nuclei over a broad excitation energy range to test up-to-date nuclear models. The extracted E1 polarizability leads to a neutron skin thickness r(skin) = 0.156(-0.021)(+0.025) fm in (208)Pb derived within a mean-field model [Phys. Rev. C 81, 051303 (2010)], thereby constraining the symmetry energy and its density dependence relevant to the description of neutron stars.

14.
Clin Nephrol ; 75(4): 384-8, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21426895

RESUMO

A 62-year-old female was admitted to our hospital for investigation of acute progressive renal insufficiency and a systemic inflammatory reaction, despite treatment with several antibiotics. Laboratory data revealed severe renal insufficiency and positive titers for the myeloperoxidase anti-neutrophil cytoplasmic and anti-glomerular basement membrane antibodies. The deterioration of her general status did not allow us to perform the renal biopsy. Although corticosteroid therapy, hemodialysis, and plasma exchange were concomitantly initiated, pulmonary hemorrhage occurred several days after admission. Mechanical ventilation support was provided and continuous hemodiafiltration was carried out, following which the respiratory failure improved immediately. However, she developed clinical depression and suicidal behavior under the intensive therapy. Therefore, plasma exchange was discontinued and corticosteroid was tapered as quickly as possible. Four months after admission, platelet transfusion and short-term mechanical ventilation support improved the pulmonary hemorrhage; however, her mental status deteriorated despite psychiatric consultation and treatment with a tranquilizer. Thereafter, severe and serious systemic infection due to various pathogens including Staphylococcus aureus, Cytomegalovirus, Pneumocystis jiroveci, Pseudomonas aeruginosa, and Bacteroides recurred, and she died from systemic invasive aspergillosis (IA). We suspected severe immunosuppression caused by various factors, such as predonisolone administration, chronic renal failure on maintenance hemodialysis, depression, and malnutrition due to chronic inflammation and granulocytopenia as a side effect of ganciclovir. When treating rapidly progressive glomerulonephritis, immunosuppressive status should be carefully monitored regarding not only the dosage of therapeutic regimen but also the mental health status and nutrition of the patient.


Assuntos
Doença Antimembrana Basal Glomerular/complicações , Doença Antimembrana Basal Glomerular/imunologia , Anticorpos Anticitoplasma de Neutrófilos/imunologia , Autoanticorpos/imunologia , Infecções Bacterianas/imunologia , Viroses/imunologia , Doença Antimembrana Basal Glomerular/terapia , Evolução Fatal , Feminino , Glucocorticoides/efeitos adversos , Glucocorticoides/uso terapêutico , Humanos , Imunossupressores/efeitos adversos , Imunossupressores/uso terapêutico , Desnutrição/complicações , Pessoa de Meia-Idade , Troca Plasmática/efeitos adversos , Prednisolona/efeitos adversos , Prednisolona/uso terapêutico , Diálise Renal/efeitos adversos
15.
J Oral Rehabil ; 38(8): 579-87, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21251043

RESUMO

The objectives of this study were to identify the regulatory relationship between tactile sensation at the vermilion of the lips and the output of pursing-like lip-closing force (LCF), as measured by a multidirectional LCF measurement system. Thirty-six healthy subjects were divided into Anaesthesia and Vaseline groups. The tactile detection threshold (TDT) at six sites on the vermilion and the maximum voluntary LCFs in eight directions were recorded before and during partial or whole application of the agent and 6 h after whole application (Recovery). Five per cent lidocaine gel and Vaseline was applied to the vermilion in the Anaesthesia and Vaseline groups, respectively. These agents were applied to either the right part of the vermilion of the lower lip (Partial) or the whole vermilion (Whole). Partial application of 5% lidocaine gel significantly decreased the magnitudes of six of eight directional LCFs, while it only increased the TDT at one site. The subsequent whole application of 5% lidocaine gel did not affect the magnitude of the LCFs in five of these six directions although its application increased the TDTs at all sites. These reductions in LCF were reversed after recovery from surface anaesthesia. Vaseline application did not affect either TDT or LCF in any conditions. We concluded that tactile sensation at the vermilion of the lips is related to the output of LCF, without any particular directional specificity. The present results suggest the presence of a common synaptic drive ordering the pursing of the relevant muscles.


Assuntos
Anestésicos Locais/administração & dosagem , Músculos Faciais/fisiologia , Lábio/fisiologia , Contração Muscular/fisiologia , Tato/fisiologia , Adulto , Músculos Faciais/anatomia & histologia , Músculos Faciais/efeitos dos fármacos , Feminino , Humanos , Lábio/anatomia & histologia , Lábio/efeitos dos fármacos , Masculino , Contração Muscular/efeitos dos fármacos , Reprodutibilidade dos Testes , Tato/efeitos dos fármacos
16.
J Oral Rehabil ; 38(12): 921-8, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21790715

RESUMO

The objectives of this study were to estimate the effects of cleft lip and/or palate (CLP) repair on the multidirectional lip-closing forces (LCF) produced during maximum voluntary pursing-like lip-closing movement in children. Thirty Japanese children were divided into the control group and repaired unilateral CLP (RUCL) group, which was subdivided into the unilateral cleft lip and/or alveolus (UCLA) and the unilateral cleft lip and cleft palate (UCLP) groups. The maximum voluntary LCF were recorded in eight directions. No significant differences in any of the directional LCF (DLCF) or total LCF were observed between RUCL and control groups. Symmetrical DLCF were seen in the oblique directions on both sides of the upper lip in the control group, while the oblique DLCF on the non-cleft side was significantly greater than that on the cleft side in RUCL group. Furthermore, symmetrical vertical DLCF were observed in the upper and lower directions in control and UCLA groups, while the vertical DLCF obtained from the lower direction was significantly greater than that obtained from the upper direction in UCLP group. These results indicate that children with repaired CLP display impaired directional specificity, which may cause secondary deformities. These findings aid our understanding of the pathology of secondary deformities in CLP patients after primary surgery for cleft lip or palate. We propose that quantitative assessments of lip-closing function based on the directional specificity of the multidirectional LCF produced during maximum voluntary pursing-like lip-closing movement are useful for assessing the nature of lip-closing dysfunctions.


Assuntos
Fenda Labial/fisiopatologia , Fissura Palatina/fisiopatologia , Músculos Faciais/fisiopatologia , Contração Muscular , Sulco Nasogeniano/fisiopatologia , Adolescente , Povo Asiático , Criança , Fenda Labial/cirurgia , Fissura Palatina/cirurgia , Músculos Faciais/cirurgia , Feminino , Humanos , Masculino , Sulco Nasogeniano/cirurgia , Resultado do Tratamento
17.
J Oral Rehabil ; 38(1): 18-26, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20722773

RESUMO

This study aimed to quantify the directional specificity of multidirectional lip-closing force (LCF) and evaluate the reliability of multidirectional LCF measurements made using a novel system. In fourteen healthy subjects (seven females, seven males, median age = 28 years), LCFs in eight directions and electromyograms (EMGs) from four parts of the orbicularis oris muscles (OOM) were recorded during voluntary pursing-like lip closure tasks. The quantitative reliability was assessed from repeated measurements of the LCFs in the eight directions and from summed values for all eight directions [total lip-closing force (TLCF)]. The intra- and inter-investigator reliabilities for TLCF were assessed by the interclass correlation of the measurements by the same investigator and two investigators, respectively. Lip-closing forces showed directional specificity in vertical, horizontal and oblique directions but those in oblique and horizontal directions were symmetrical bilaterally. The quantitative reliability of measurements was between 0·735 and 0·948 in the eight directions and that of TLCF was 0·934. Interclass correlations of intra- and inter-investigator reliabilities were 0·96 [lower limit of 95% confidence interval (95% LL), 0·87] and 0·96 (95% LL, 0·91), respectively. The intra- and inter-investigator differences of measurements were randomly distributed in the whole range of measurements. The 95% confidence intervals of these differences were significantly narrower than those of the limits of agreement (mean ± 1·96 s.d.). In 13 subjects, Pearson's correlation coefficients between LCF and EMGs from OOM were above 0·95. We conclude that this system has a reasonable quality and reliability for quantitative measurements of multidirectional LCF for evaluating lip functions.


Assuntos
Músculos Faciais/fisiologia , Lábio/fisiologia , Adulto , Eletromiografia , Feminino , Humanos , Masculino , Reprodutibilidade dos Testes
18.
Mater Today Bio ; 12: 100144, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34632359

RESUMO

The hydrolytic processes occurring at the surface of silicon nitride (Si3N4) bioceramic have been indicated as a powerful pathway to instantaneous inactivation of SARS-CoV-2 virus. However, the virus inactivation mechanisms promoted by Si3N4 remain yet to be elucidated. In this study, we provide evidence of the instantaneous damage incurred on the SARS-CoV-2 virus upon contact with Si3N4. We also emphasize the safety characteristics of Si3N4 for mammalian cells. Contact between the virions and micrometric Si3N4 particles immediately targeted a variety of viral molecules by inducing post-translational oxidative modifications of S-containing amino acids, nitration of the tyrosine residue in the spike receptor binding domain, and oxidation of RNA purines to form formamidopyrimidine. This structural damage in turn led to a reshuffling of the protein secondary structure. These clear fingerprints of viral structure modifications were linked to inhibition of viral functionality and infectivity. This study validates the notion that Si3N4 bioceramic is a safe and effective antiviral compound; and a primary antiviral candidate to replace the toxic and allergenic compounds presently used in contact with the human body and in long-term environmental sanitation.

19.
J Exp Med ; 186(4): 561-8, 1997 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-9254654

RESUMO

Interleukin-5 (IL-5) regulates the growth and function of eosinophils. It induces rapid tyrosine phosphorylation of Lyn and Jak2 tyrosine kinases. The role of tyrosine phosphatases in IL-5 signal transduction has not been investigated. In this study, we provide first evidence that SH2 protein tyrosine phosphatase 2 (SHPTP2) phosphotyrosine phosphatase plays a key role in prevention of eosinophil death by IL-5. We found that IL-5 produced a rapid activation and tyrosine phosphorylation of SHPTP2 within 1 min. The tyrosine phosphorylated SHPTP2 was complexed with the adapter protein Grb2 in IL-5-stimulated eosinophils. Furthermore, SHPTP2 appeared to physically associate with beta common (betac) chain of the IL-5 receptor (IL-5betacR). The association of SHPTP2 with IL-5betacR was reconstituted using a synthetic phosphotyrosine-containing peptide, betac 605-624, encompassing tyrosine (Y)612. The binding to the phosphotyrosine-containing peptide increased the phosphatase activity of SHPTP2, whereas the same peptide with the phosphorylated Y612--> F mutation did not activate SHPTP2. Only SHPTP2 antisense oligonucleotides, but not sense SHPTP2, could inhibit tyrosine phosphorylation of microtubule-associated protein kinase, and reverse the eosinophil survival advantage provided by IL-5. Therefore, we conclude that the physical association of SHPTP2 with the phosphorylated betac receptor and Grb2 and its early activation are required for the coupling of the receptor to the Ras signaling pathway and for prevention of eosinophil death by IL-5.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal , Eosinófilos/fisiologia , Proteínas Tirosina Fosfatases/fisiologia , Receptores de Interleucina/fisiologia , Transdução de Sinais , Sequência de Aminoácidos , Sobrevivência Celular , Proteína Adaptadora GRB2 , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , Dados de Sequência Molecular , Oligonucleotídeos Antissenso/farmacologia , Proteína Fosfatase 2 , Proteína Tirosina Fosfatase não Receptora Tipo 11 , Proteína Tirosina Fosfatase não Receptora Tipo 6 , Proteínas/fisiologia , Receptores de Interleucina-5
20.
Br J Surg ; 97(4): 544-9, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20155791

RESUMO

BACKGROUND: Helicobacter bilis is considered to be a causative factor in the pathogenesis of biliary cancer. This study investigated the prevalence of H. bilis colonization of the biliary system of patients with pancreaticobiliary maljunction (PBM). METHODS: Bile juice and biliary tissue samples were collected from 17 patients with PBM and 27 controls who had benign biliary disease without PBM. DNA extracted from each biliary sample was subjected to polymerase chain reaction (PCR) analysis for H. bilis and Helicobacter pylori. RESULTS: PCR assays revealed that 12 of the 17 patients with PBM were positive for H. bilis DNA, compared with eight of 27 patients without PBM (P = 0.009). Among patients with PBM, H. bilis DNA was identified in six of eight children, including a 2-month-old infant, and in six of nine adults. The high prevalence of H. bilis DNA in the biliary system of patients with PBM was independent of age, sex, common bile duct dilatation, configuration of the pancreatic and bile ducts, and amylase activity in bile. CONCLUSION: H. bilis colonization of the biliary system is extremely common in patients with PBM. This may point to a role in the pathogenesis of biliary cancer.


Assuntos
Ductos Biliares/anormalidades , Neoplasias do Sistema Biliar/microbiologia , Infecções por Helicobacter , Helicobacter/isolamento & purificação , Ductos Pancreáticos/anormalidades , RNA Bacteriano/análise , Adolescente , Adulto , Idoso , Bile/microbiologia , Sistema Biliar/microbiologia , Estudos de Casos e Controles , Criança , Pré-Escolar , Eletroforese , Feminino , Helicobacter/genética , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase
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