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1.
Nature ; 613(7944): 479-484, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36653570

RESUMO

Chiral molecules can exhibit spin-selective charge emission, which is known as chirality-induced spin selectivity1,2. Despite the constituent light elements of the molecules, their spin polarization can approach or even exceed that of typical ferromagnets. This powerful capability may lead to applications in the chiral spintronics2 field. Although the origin of spin selectivity is elusive, two microscopic phenomena have been suggested based on experimental results: effective enhancement of spin-orbit interactions3 and chirality represented by a pair of oppositely polarized spins4,5. However, the hypotheses remain to be verified. Here we report the simultaneous observation of these two phenomena in an organic chiral superconductor by magnetoresistance measurements in the vicinity of the superconducting transition temperature. A pair of oppositely polarized spins is demonstrated by spatially mapping the spin polarity in an electric alternating current excitation. The obtained spin polarization exceeds that of the Edelstein effect6-10 by several orders of magnitude, which indicates an effective enhancement of the spin-orbit interaction. Our results demonstrate a solid-state analogue of spin accumulations assumed for chiral molecules, and may provide clues to the origin of their molecular counterparts. In addition, the innovative capability of spin-current sourcing will invigorate superconducting spintronics research11.

2.
Nat Commun ; 11(1): 4138, 2020 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-32811820

RESUMO

Charge acceleration during an intense light field application to solids attracts much attention as elementary processes in high-harmonic generation and photoelectron emission. For manipulating such attosecond dynamics of charge, carrier-envelope-phase (CEP: relative phase between carrier oscillation of light field and its envelope function) control has been employed in insulators, nanometal and graphene. In superconducting materials, collective control of charge motion is expected because of its strongly coherent nature of quasi-particles. Here we report that, in a layered organic superconductor, a non-linear petahertz current driven by a single-cycle 6 femtosecond near infrared field shows up as second harmonic generation (SHG), which is in contrast to the common belief that even harmonics are forbidden in the centrosymmetric system. The SHG represents a CEP sensitive nature and an enhancement near the superconducting temperature. The result and its quantum many-body analysis indicate that a polarized current is induced by non-linear acceleration of charge, which is amplified by superconducting fluctuations. This will lead to petahertz functions of superconductors and of strongly correlated systems.

3.
Transplant Proc ; 51(3): 774-778, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30979463

RESUMO

BACKGROUND: Brachytherapy is one of the standard treatments for localized prostate cancer (CaP). However, the feasibility of brachytherapy for renal transplant recipients (RTRs) is still uncertain. MATERIALS AND METHODS: Between August 2007 and March 2018, all patients who had undergone low-dose-rate (LDR) brachytherapy or high-dose-rate (HDR) brachytherapy for clinically localized CaP at our institution were retrospectively identified (n = 394). Of these patients, 3 had a history of renal transplantation. We reviewed all available clinical data retrospectively. RESULTS: All of the RTRs received ABO-incompatible renal grafts from their spouses and had stable renal graft function before the diagnosis of CaP. The median age at diagnosis of CaP was 65 years (range, 60-67 years). The median time between transplantation and brachytherapy was 7 years (range, 4-10 years). In all of the patients, clinical stage was cT1cN0M0. Two patients received 125I LDR-brachytherapy (dose, 145 Gy) and 1 patient was treated by 192Ir HDR brachytherapy (dose, 19 Gy in 2 fractions) combined with external beam radiation therapy of 39 Gy in 13 fractions. The median follow-up period after brachytherapy was 44 months (range, 34-50 months). During the follow-up period, none of the patients developed disease progression including biochemical recurrence or clinically significant adverse events associated with radiation therapy. CONCLUSIONS: LDR brachytherapy and HDR brachytherapy are safe and technically feasible in RTRs with CaP, and oncological outcomes in RTRs do not appear to be inferior to those of patients who did not receive renal transplant.


Assuntos
Braquiterapia/métodos , Transplante de Rim , Neoplasias da Próstata/radioterapia , Sistema ABO de Grupos Sanguíneos , Idoso , Histocompatibilidade , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias da Próstata/complicações , Dosagem Radioterapêutica , Estudos Retrospectivos , Transplantados , Resultado do Tratamento
4.
Rev. méd. Chile ; 128(1): 27-34, ene. 2000. tab, graf
Artigo em Espanhol | LILACS | ID: lil-258084

RESUMO

Background: The virulence of Streptococcus pyogenes is determined by a variety of structural molecules, toxins and complex enzymes. Pyrogenic exotoxins cause fever, erythematous reactions, cytotoxic and immunological effects. Aim: To assess the frequency of speA, speB and speC genes in Chilean Streptococcus pyogenes strains and their association with the invasiveness of infections. Material and methods: The genes for pyrogenic exotoxins SpeA, SpeB and SpeC were determined by polymerase chain reactions in 114 strains of group A Streptococcus pyogenes isolated from Chilean patients with invasive or non invasive infections. Results: The gene for SpeA was present in 30.7 percent of isolates, the gene for SpeB was present in 69.3 percent and the gen for SpeC in 44.7 percent of isolates. The gene for SpeA was present in 20 of 33 invasive infections and in 15 of 81 non invasive infections (p <0.0001). On the contrary, the gene for SpeC was present in 11 of 33 invasive infections and in 41 of 81 non invasive infections (p <0.05). The frequency of speB was similar in invasive and non invasive infections. Conclusions: There is a clear relationship between the presence of SpeA genes and the severity of infections caused by Streptococcus pyogenes


Assuntos
Streptococcus pyogenes/genética , Técnicas In Vitro , Reação em Cadeia da Polimerase , Exotoxinas/genética , Frequência do Gene , Genótipo
5.
Kyobu Geka ; 48(6): 484-6, 1995 Jun.
Artigo em Japonês | MEDLINE | ID: mdl-7602863

RESUMO

A 63-year-old man was admitted to the hospital for the treatment of annulo-aortic ectasia with severe aortic regurgitation. The aortogram revealed dilatation of the aortic root and severe aortic regurgitation. LVEDVI was 207 ml/m2 but the patient was asymptomatic. Aortic root reconstruction was performed with Cabrol procedure using zero-porosity graft. There was no evidence of bleeding due to this graft and the percent dilatation of this graft was 33%. This zero-porosity graft of knitted Dacron coated with gelatin seems to offer some advantages to the operation. The patient is in stable health today, but perioperative occurrence of VPCs may have owed to diminished LV function caused by severe aortic regurgitation.


Assuntos
Aneurisma da Aorta Torácica/cirurgia , Insuficiência da Valva Aórtica/cirurgia , Prótese Vascular/métodos , Aorta Torácica/patologia , Aorta Torácica/cirurgia , Aneurisma da Aorta Torácica/complicações , Insuficiência da Valva Aórtica/complicações , Dilatação Patológica/complicações , Humanos , Masculino , Pessoa de Meia-Idade
7.
Int Immunol ; 6(9): 1345-52, 1994 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-7819142

RESUMO

We investigated T cell recognition for human minor histocompatibility (hmH) peptides using HLA-B*3501 restricted, hmH specific cytotoxic T lymphocytes (CTL) clones. These CTL clones killed C1R cells expressing HLA-B*3501 but not C1R cells expressing chimeric antigens between HLA-B*3501 and HLA-B*5101. They also failed to kill C1R cells expressing HLA-B*3501 mutants at residue 152 (B*3501-V152E) or at residue 171 (B*3501-Y171H). The CTL clone failed to kill C1R cells expressing these mutant molecules loaded with the hmH peptides isolated from C1R-B*3501 cells although it killed a self-B cell line expressing HLA-B3501 loaded with the specific hmH peptides. The CTL clone also failed to kill T2 cells expressing the mutant molecules loaded with the specific peptides whereas it killed T2 cells expressing HLA-B*3501 loaded with the specific peptide. On the other hand, naturally occurring specific hmH peptides were isolated from purified B*3501-V152E and B*3501-Y171H molecules, indicating that both HLA-B*3501-V152E and HLA-B*3501-Y171H molecules can bind the hmH peptides. These findings indicate that both the conserved residue 171 in pocket A and the polymorphic residue 152 in pocket E are critical in recognition of the T cells but not binding of the hmH peptides. Furthermore, these results provide the possibility that the TCR recognizes a conformational structure of hmH peptides bound to HLA-B*3501 molecules.


Assuntos
Apresentação de Antígeno/imunologia , Antígeno HLA-B35/imunologia , Antígenos de Histocompatibilidade Menor/imunologia , Linfócitos T/imunologia , Linfócitos B/imunologia , Células Cultivadas , Células Clonais , Citotoxicidade Imunológica , Citometria de Fluxo , Antígeno HLA-B35/genética , Humanos , Linfócitos T Citotóxicos/imunologia , Transfecção
8.
Hepatogastroenterology ; 41(3): 235-8, 1994 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-7959545

RESUMO

Of 798 hepatitis B virus (HBV) carriers, 22 had low titers (lower than 80% inhibition in 200- or 400-fold diluted serum) of antibody to hepatitis B core antigen (anti-HBc). Among these 22 patients, there were 12 (1.50%) with viremia who were positive for hepatitis B e antigen and had a high titer of HBV-associated DNA polymerase activity. Among these 12 patients, four showed no significant change in the anti-HBc titer, while four others showed significant increases in the anti-HBc titer during the follow-up periods. The former all remained asymptomatic carriers (ASCs), while the latter all developed chronic hepatitis (CH). The liver histology of four patients (ASC: 2, CH: 2) showed mild inflammation, and the localization of hepatitis B core antigen (HBcAg) in the liver specimens showed a nuclear pattern in the two ASCs, but a nuclear plus cytoplasmic pattern in the two CH cases. In HBV carriers, the increase in anti-HBc titer seems to be closely correlated to the change in HBcAg localization from the nucleus to the cytoplasm in the liver. Therefore, rising titers of anti-HBc were assumed to be associated with increased expression of HBcAg on the hepatocyte, and hence increased immune-mediated hepatic damage and the onset of hepatitis in ASC with low titer of anti-HBc.


Assuntos
Portador Sadio/metabolismo , Anticorpos Anti-Hepatite B/metabolismo , Antígenos do Núcleo do Vírus da Hepatite B/metabolismo , Hepatite B/metabolismo , Fígado/metabolismo , Viremia/metabolismo , Adolescente , Adulto , Idoso , Doença Crônica , DNA Polimerase Dirigida por DNA/metabolismo , Feminino , Seguimentos , Antígenos E da Hepatite B/metabolismo , Humanos , Fígado/patologia , Masculino , Pessoa de Meia-Idade
9.
Hum Immunol ; 39(3): 211-9, 1994 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-8026989

RESUMO

We recently showed that a single amino acid substitution of tryptophane into glycine at residue 167 facing the "A pocket" forms a novel HLA-B51 subtype, B*5103, which is serologically discriminated as HLA-BTA. CDC assay of human alloantisera specific for the HLA-B5 CREG against B*5103- or B*5101-transfected human B-cell line, Hmy2C1R (C1R), supported the belief that human alloantisera can discriminate B*5103 from B*5101 Ag. Moreover, we found that 4D12 anti-B5, B35 CREG mAb cannot bind to B*5103 Ag on C1R cells or L cells although it binds to B*5101 Ag on both cells. These results indicate that alloantibodies can detect a single amino acid substitution at residue 167. Furthermore, it was suggested that 4D12 mAb recognizes the structure formed by the HLA-peptide complex since this mAb did not bind to empty HLA-B5, B35 CREG Ag on RMA-S transfectants. Six of eight anti-HLA-B*5101 CTL clones are not able to kill C1R cells expressing B*5103, indicating that conformational change of the A pocket by substitution at residue 167 has a crucial influence on recognition of alloreactive T cells. Therefore, discrimination of B*5103 from B*5101 would seem to be important in bone marrow transplantation.


Assuntos
Aminoácidos/química , Antígenos HLA-B/química , Antígenos HLA-B/imunologia , Linfócitos T Citotóxicos/imunologia , Sequência de Aminoácidos , Sítios de Ligação de Anticorpos , Linhagem Celular , Testes Imunológicos de Citotoxicidade , Antígeno HLA-B35/imunologia , Antígeno HLA-B51 , Humanos , Isoanticorpos/imunologia , Dados de Sequência Molecular , Relação Estrutura-Atividade , Transfecção
11.
Hum Immunol ; 36(3): 193-8, 1993 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-7686546

RESUMO

Two genes encoding HLA-B60 or HLA-B61 were cloned from Japanese and the exons of their genes were sequenced. One silent mutation was observed at the exon 1 between HLA-B60 (B*40012) and B*40011. Seven nucleotide substitutions were seen at the exon 3 between HLA-B61 (B*4006) and B*4002. Three substitutions at codon 95, CTC in B*4002 to TGG in B*4006, changed Leu in B*4002 to Trp in B*4006, while two substitutions at codon 97, AGC in B*4002 and ACG in B*4006, changed Ser in B*4002 to Thr in B*4006. Since B*4002 shares the epitope of alloantibodies specific for HLA-B61, two HLA-B61 subtypes are discriminated by two amino acid substitutions at residues 95 and 97. B*40012 and B*4006 differ by four amino acid substitutions on the beta sheet and five amino acid substitutions on the alpha 2 helix. Since the residues at the beta sheet seem hardly to affect the binding of alloantibody, it is suspected that the residues on the alpha 2 helix provide epitopes for alloantibodies that discriminate allospecificity between HLA-B60 and HLA-B61.


Assuntos
Genes MHC da Classe II , Antígenos HLA-B/química , Sequência de Aminoácidos , Sequência de Bases , Clonagem Molecular , Testes Imunológicos de Citotoxicidade , Análise Mutacional de DNA , Epitopos/química , Epitopos/imunologia , Antígenos HLA-B/genética , Antígenos HLA-B/imunologia , Antígeno HLA-B40 , Humanos , Modelos Moleculares , Dados de Sequência Molecular , Conformação Proteica , Homologia de Sequência
12.
Immunogenetics ; 37(1): 57-63, 1992.
Artigo em Inglês | MEDLINE | ID: mdl-1428012

RESUMO

Newly defined antigens of the B5, B35 cross-reacting group have been found in Japanese and North American Indians. Nucleotide sequencing of the alleles encoding the Japanese B5.35 antigen and the variant B5 antigen from the Piman Indians show them to be identical. This new allele, B*5102, differs from B*5101 by a single nucleotide substitution that changes residue 171 from histidine to tyrosine. Residue 171, which is part of the alpha 2 helix, is believed to contribute directly to peptide interaction in the A pocket of the binding groove and is either histidine or tyrosine in all HLA-A, B, C heavy chains. Tyrosine 171 is shared by B*5102, B*3501, B*3502, and B*5301 and must be responsible for the serological cross-reactivities of these molecules not shared with B*5101. Stimulation of lymphocytes from a B*5101 positive donor with B*5102 positive cells failed to generate cytotoxic T cells with specificity for the difference between these molecules. However, one out of five clones of cytotoxic T cells raised against B*5101 failed to lyse targets expressing B*5102. Substitution of histidine for tyrosine at residue 171 affected recognition of HLA-B35-restricted human minor histocompatibility antigen-specific T cell clones.


Assuntos
Antígenos HLA-B/genética , Mutação , Sequência de Aminoácidos , Sequência de Bases , Evolução Biológica , Células Cultivadas , DNA , Antígenos HLA-B/química , Histidina/genética , Humanos , Indígenas Norte-Americanos/genética , Japão , Dados de Sequência Molecular , Conformação Proteica , Homologia de Sequência de Aminoácidos , Homologia de Sequência do Ácido Nucleico , Linfócitos T Citotóxicos/imunologia , Tirosina/genética
14.
Jpn J Surg ; 20(2): 212-6, 1990 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-2342239

RESUMO

Twenty adult male Japanese monkeys of the species Macaca fuscata were randomly paired and subjected to heterotopic cardiac transplantation performed by the Ono-Lyndsey method. Without immunosuppression, graft survival ranged between 8 and 27 days, with a mean survival of 14 days. Plasma cardiac myosin light chains were measured by radioimmunoassay, which showed transient increases in myosin levels just following transplantation. Three hearts showed high values at this period and stopped beating when the myosin levels decreased (type 1). The other 7 hearts showed low myosin values after transient increases and 5 of them were rejected with a preceding reincrease in the myosin levels (type 2). Pathological study revealed myocardial necrosis, perivascular cuffing of mononuclear cells and/or neutrophils and/or plasma cells in the type 1 hearts. Measurement of the plasma myosin light chain level was therefore revealed to be of great value in the monitoring of cardiac allograft rejection.


Assuntos
Rejeição de Enxerto , Transplante de Coração , Miosinas/sangue , Animais , Sobrevivência de Enxerto , Parada Cardíaca/sangue , Transplante de Coração/métodos , Transplante de Coração/patologia , Macaca , Masculino , Miocárdio/patologia , Necrose , Distribuição Aleatória
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