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1.
Intern Med ; 2024 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-39111891

RESUMO

We herein report two patients with anti-muscle-specific kinase (MuSK) antibody-positive myasthenia gravis who experienced rapid deterioration of weakness, particularly respiratory muscle weakness, necessitating non-invasive positive pressure ventilation (NIPPV) and were treated with efgartigimod. After treatment initiation, a rapid reduction in IgG levels and recovery from clinical symptoms were observed. NIPPV was no longer required two to three weeks after the first infusion of efgartigimod. These findings suggest that the reduction of IgG levels using efgartigimod is a good treatment option in patients with myasthenia gravis positive for anti-MuSK antibodies, even during the acute phase of the disease.

4.
Sci Rep ; 13(1): 18029, 2023 10 21.
Artigo em Inglês | MEDLINE | ID: mdl-37865708

RESUMO

Although testosterone is generally considered to promote dominance behaviors, in humans it fosters behaviors appropriate to achieving and maintaining social status, contingent upon the situation. Recent cross-sectional studies, such as Inoue et al. (Sci Rep 7:5335, 2017), have shown that dominance behaviors induced by testosterone are modulated by high status. Yet, it remains ambiguous whether a rise in social status within real-world social groups reshapes the relationship between testosterone and dominance behavior. To investigate this longitudinal question, we added a second wave to Inoue et al.'s study, collecting further data after an interval of 2 years. Members of a university rugby team that adheres to a rigid hierarchical order rooted in seniority played the Ultimatum Game with teammates and provided saliva for assays of testosterone and cortisol. Our analysis reveals that individuals with higher baseline salivary testosterone levels exhibited more dominance as their position in the hierarchy increased according to their seniority.


Assuntos
Comportamento Competitivo , Testosterona , Humanos , Testosterona/análise , Predomínio Social , Saliva/química , Estudos Transversais , Hidrocortisona/análise
5.
J Pers Soc Psychol ; 123(5): 1024-1088, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35286118

RESUMO

Impersonal cooperation among strangers enables societies to create valuable public goods, such as infrastructure, public services, and democracy. Several factors have been proposed to explain variation in impersonal cooperation across societies, referring to institutions (e.g., rule of law), religion (e.g., belief in God as a third-party punisher), cultural beliefs (e.g., trust) and values (e.g., collectivism), and ecology (e.g., relational mobility). We tested 17 preregistered hypotheses in a meta-analysis of 1,506 studies of impersonal cooperation in social dilemmas (e.g., the Public Goods Game) conducted across 70 societies (k = 2,271), where people make costly decisions to cooperate among strangers. After controlling for 10 study characteristics that can affect the outcome of studies, we found very little cross-societal variation in impersonal cooperation. Categorizing societies into cultural groups explained no variance in cooperation. Similarly, cultural, ancestral, and linguistic distance between societies explained little variance in cooperation. None of the cross-societal factors hypothesized to relate to impersonal cooperation explained variance in cooperation across societies. We replicated these conclusions when meta-analyzing 514 studies across 41 states and nine regions in the United States (k = 783). Thus, we observed that impersonal cooperation occurred in all societies-and to a similar degree across societies-suggesting that prior research may have overemphasized the magnitude of differences between modern societies in impersonal cooperation. We discuss the discrepancy between theory, past empirical research and the meta-analysis, address a limitation of experimental research on cooperation to study culture, and raise possible directions for future research. (PsycInfo Database Record (c) 2022 APA, all rights reserved).


Assuntos
Comparação Transcultural , Religião , Comportamento Cooperativo , Humanos , Confiança
6.
Front Psychol ; 13: 895619, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36760903

RESUMO

Recently, altruism toward future generations (future altruism) has become a hot research topic. Although future altruism has been observed in several previous experiments, it is not yet clear when and why people are more likely to engage in future altruism. Drawing upon the empirical literature of reputation and cooperation, we predicted that future altruism brings reputational disadvantages. Accordingly, we investigated whether future altruism was evaluated positively or negatively by others in the current generation in two vignette studies (total N = 1,237). Contrary to our initial prediction, we found that future altruism was positively evaluated even when it decreased the payoff of the members of the current generation. The difference in the evaluation of future altruism, as opposed to unsustainable current-generation focused behavior, was most pronounced when people do not know how a future altruist allocates rewards among individuals in the current generation. However, the positive evaluation of future altruism did not stem from the expectation that future altruists would also be altruistic toward the current generation. These results indicated that reputational benefits (i.e., positive reputation from others in the current generation) promote future altruism.

7.
J Dermatol ; 48(10): 1564-1568, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34155694

RESUMO

Atopic dermatitis (AD) is the most common inflammatory skin disease affecting people of all age groups worldwide. To our knowledge, there are currently no studies estimating the effectiveness of tacrolimus ointment and dupilumab as a combination therapy for AD. Thus, here we describe the effectiveness and safety of tacrolimus ointment in combination with dupilumab for facial rashes in patients with AD. Overall, we included 109 patients who newly received dupilumab from April 2018 to July 2020 in the Dermatology Department of Hyogo College of Medicine Hospital. Of them, 60 patients were treated with tacrolimus ointment. Specifically, of the 60 patients, 40 were treated with dupilumab in combination with tacrolimus ointment and topical steroids, whereas the remaining 20 were prescribed tacrolimus ointment alone and were further analyzed. The analysis showed that the combination does not cause serious side-effects at high frequency. The patients showed rapid improvement of facial dermatitis along with systemic dermatitis, and the rate of improvement of head/neck Eczema Area and Severity Index (EASI) score significantly correlated with the rate of improvement of overall EASI score. In addition, there was no complication of herpes simplex observed in these 20 patients. Thus, tacrolimus ointment combined with dupilumab is an effective and safe treatment option for facial AD.


Assuntos
Dermatite Atópica , Eczema , Anticorpos Monoclonais Humanizados , Dermatite Atópica/tratamento farmacológico , Humanos , Imunossupressores , Pomadas , Tacrolimo , Resultado do Tratamento
8.
Sci Rep ; 11(1): 5373, 2021 03 08.
Artigo em Inglês | MEDLINE | ID: mdl-33686096

RESUMO

Today, developing and maintaining sustainable societies is becoming a notable social concern, and studies on altruism and prosociality toward future generations are increasing in importance. Although altruistic behaviors toward future generations have previously been observed in some experimental situations, it remains unknown whether prosocial preferences toward future others are based on equality or joint outcome orientations. In the present research, we exploratorily investigated preferences regarding resource distribution by manipulating the time points (i.e., present/future) of the participants and their imaginary partners. The results indicate that prosocial preference toward future others was as strong as that toward present others and seemed to be based on a joint outcome prosocial preference. Notably, when participants and their partners were at different time points, participants preferred to leave resources for the persons in the future. The findings indicate that the type of altruistic preference toward future others may differ from that toward present others, which is mainly equality.

9.
Graefes Arch Clin Exp Ophthalmol ; 256(10): 1953-1960, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29926168

RESUMO

PURPOSE: The purpose of this study was to evaluate the surgical success of sulcus fixation of Baerveldt glaucoma implant (BGIs) in special reference to corneal damage. METHODS: This observational prospective cohort study included 24 patients who underwent a median of 3.0 previous intraocular surgeries and sulcus fixation of BGIs for the first time. The intraocular pressure (IOP), the number of ocular hypotensives used, corneal endothelial cell density (ECD), and logMAR-converted best-corrected visual acuity (VA) of each patient were measured preoperatively and postoperatively until 12 months after surgery. Surgical success was evaluated after 12 months based on the reduction of IOP (5-21 mmHg and > 20% reduction), corneal damage (postoperative development of decompensation, unmeasurable ECD, or ECD reduction of > 20%), loss of light perception, and need for additional surgeries. RESULTS: Surgical success was noted in 16 (66.7%) patients when corneal damage was included as a failure criterion, whereas surgery was successful in 21 (87.5%) patients when solely judged using IOP control similarly as previous clinical trials. The median IOP decreased from 27.5 mmHg preoperatively to 14.5 mmHg postoperatively (P < 0.0001). The number of ocular hypotensives was significantly reduced postoperatively (P < 0.0001). The median postoperative ECD reduction was only 0.15%, although ECD could not be measured during follow-up or it was significantly reduced by > 20% in six patients. VA was not significantly reduced after surgery. Adverse effects were observed in 15 patients (62.5 cumulative %). CONCLUSION: Sulcus fixation of BGIs may be effective and safe in patients with glaucomatous eyes who underwent multiple prior intraocular surgeries.


Assuntos
Corpo Ciliar/cirurgia , Implantes para Drenagem de Glaucoma , Glaucoma/cirurgia , Pressão Intraocular/fisiologia , Procedimentos Cirúrgicos Oftalmológicos/métodos , Implantação de Prótese/métodos , Acuidade Visual , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Seguimentos , Glaucoma/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Reoperação , Resultado do Tratamento
10.
Ophthalmologica ; 240(2): 106-110, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29742514

RESUMO

PURPOSE: This study evaluates optical coherence tomography (OCT) findings of the macula in patients with a history of retinopathy of prematurity (ROP). METHODS: We enrolled 112 patients (age: 6-15 years) and categorized them into 3 groups: gestational age (GA) < 36 weeks with or without a history of ROP (ROP group, preterm group) and GA ≥37 weeks. We included 1 eye of each patient and measured the retinal thickness of the macula by OCT. RESULTS: The ROP group demonstrated the worst VA and the shallowest foveal depression. Furthermore, foveal depression significantly correlated with birth weight, GA, ganglion cell layer/inner plexiform layer (GCL-IPL) thickness, and a history of ROP. CONCLUSIONS: This study established a correlation of fovea formation with premature birth, damage of GCL-IPL, and a history of ROP. The retention of the inner retina possibly contributes to abnormal foveal morphology in patients with a history of ROP.


Assuntos
Fóvea Central/diagnóstico por imagem , Recém-Nascido Prematuro , Retina/patologia , Retinopatia da Prematuridade/diagnóstico , Tomografia de Coerência Óptica/métodos , Acuidade Visual , Adolescente , Criança , Feminino , Idade Gestacional , Humanos , Recém-Nascido , Masculino , Retinopatia da Prematuridade/fisiopatologia
11.
PLoS One ; 13(1): e0191862, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29373604

RESUMO

PURPOSE: We previously reported that eyes with hypotony maculopathy (HM) after trabeculectomy (TLE) exhibited more reduction of axial length (AL) than those without HM, suggesting that inward collapse of the scleral wall may contribute to the development of HM after TLE. However, we did not evaluate change in choroidal thickness (CT), which could influence AL measures. We compared the magnitude and rate of AL and CT changes in eyes with and without HM by simultaneously measuring these parameters before and after TLE. METHODS: We enrolled 77 eyes of 77consecutive patients with glaucoma, who underwent TLE between March 2014 and March 2016. Intraocular pressure (IOP), central corneal thickness, keratometry, AL, and CT were measured pre- and postoperatively, up to 6 months. These biometrics were compared in eyes with and without HM. RESULTS: The 14 patients who developed HM were significantly younger than those who did not. The eyes with HM exhibited significantly reduced AL (2.8%) compared to those without HM (0.7%). There was no significant difference in CT change between the two groups. The rate of AL reduction was significantly correlated with age, postoperative IOP, and preoperative AL. Post-adjustment logistic regression analysis revealed that eyes with AL reduction rate ≥ 2% had 11.67 higher risk for developing HM (95% confidence interval, 1.28-106.6; P = 0.03). CONCLUSIONS: AL reduction rates ≥ 2% were significantly associated with HM. Excessive reduction in AL, which was seen in eyes with HM, was not an artificial measure resulting from choroidal thickening but rather reflected reductions in the anterior-posterior diameter of the eyeball. Inward collapse of the scleral wall leads to redundancy of the chorioretinal tissue, contributing to the development of HM after TLE.


Assuntos
Corioide/patologia , Hipotensão Ocular/etiologia , Hipotensão Ocular/patologia , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/patologia , Esclera/patologia , Trabeculectomia/efeitos adversos , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Paquimetria Corneana , Estudos Transversais , Feminino , Glaucoma de Ângulo Aberto/patologia , Glaucoma de Ângulo Aberto/fisiopatologia , Glaucoma de Ângulo Aberto/cirurgia , Humanos , Pressão Intraocular , Masculino , Pessoa de Meia-Idade , Hipotensão Ocular/fisiopatologia , Fatores de Risco
12.
Jpn J Ophthalmol ; 62(1): 31-40, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29027590

RESUMO

PURPOSE: To assess the combined estimate of retinal ganglion cell (RGC) count developed by Medeiros et al. as a tool for diagnosis of glaucoma in Japanese patients. STUDY DESIGN: Cross-sectional study. METHODS: Thirty-one eyes of 19 healthy controls and 106 eyes of 70 glaucoma patients underwent standard automated perimetry (SAP) and three types of spectral domain optical coherence tomography (SD-OCT) imaging using the Cirrus, RTVue, and 3D-OCT instruments. RGC counts derived from SAP and SD-OCT data were estimated using the Harwerth model (SAPrgc and OCTrgc, respectively), from which the combined RGC count estimates (CRGC) were calculated using the formula developed by Medeiros et al. Receiver operating characteristic curve (ROC) analyses were conducted for mean deviation (MD), retinal nerve fiber layer thickness (RNFLT), and CRGC. RESULTS: The mean OCTrgc derived from the Cirrus, RTVue, and 3D-OCT instruments were 1150, 1245, and 1316 (× 1000 cells), respectively, for the control group and 463, 519, and 516 (× 1000 cells), respectively, for the patient group. SAPrgc of the controls' group was 1526 and the patients' group, 731 (× 1000 cells), and were consistently greater than OCTrgc in both groups (a generalized estimating equation model, p < 0.001). Partial area under the curve (pAUC) of MD was 0.178, and that of RNFLT and CRGC for the three OCT instruments were 0.185, 0.18, 0.189 and 0.196, 0.196, 0.197, respectively. CRGC had larger pAUC than MD, whereas there was no or marginal difference in pAUC between CRGC and cpRNFLT, irrespective of OCT device used or glaucoma severity. CONCLUSION: CRGC proved well suited to discriminate glaucoma patients from controls. However, its clinical utility did not seem to overwhelm isolated structural measures in the tested Japanese patients.


Assuntos
Glaucoma de Ângulo Aberto/diagnóstico , Fibras Nervosas/patologia , Disco Óptico/patologia , Doenças do Nervo Óptico/diagnóstico , Células Ganglionares da Retina/patologia , Adulto , Área Sob a Curva , Povo Asiático/etnologia , Contagem de Células , Estudos Transversais , Feminino , Glaucoma de Ângulo Aberto/etnologia , Humanos , Pressão Intraocular , Japão/epidemiologia , Masculino , Pessoa de Meia-Idade , Doenças do Nervo Óptico/etnologia , Curva ROC , Tomografia de Coerência Óptica/métodos , Tonometria Ocular , Testes de Campo Visual , Campos Visuais
13.
Sci Rep ; 7(1): 5335, 2017 07 13.
Artigo em Inglês | MEDLINE | ID: mdl-28706184

RESUMO

Endogenous testosterone promotes behaviours intended to enhance social dominance. However, recent research suggests that testosterone enhances strategic social behaviour rather than dominance seeking behaviour. This possibility has not been tested in a population whose members are known to vary in social status. Here, we explored the relationship between pre-existing social status and salivary testosterone level among members of a rugby team at a Japanese university, where a strong seniority norm maintains hierarchical relationships. Participants played a series of one-shot Ultimatum Games (UG) both as proposer and responder. Opponents were anonymised but of known seniority. We analysed participants' acquiescence (how much more they offered beyond the lowest offer they would accept). The results showed that, among the most senior participants, higher testosterone was associated with lower acquiescence. Conversely, higher testosterone among the lower-status participants was associated with higher acquiescence. Our results suggest that testosterone may enhance socially dominant behaviour among high-status persons, but strategic submission to seniority among lower-status persons.


Assuntos
Atletas , Saliva/química , Comportamento Social , Testosterona/análise , Adolescente , Adulto , Humanos , Japão , Masculino , Estudantes , Universidades , Adulto Jovem
14.
Nippon Ganka Gakkai Zasshi ; 121(4): 366-72, 2017 Apr.
Artigo em Japonês | MEDLINE | ID: mdl-30070445

RESUMO

Purpose: To evaluate Icare® HOME for home monitoring of intraocular pressure (IOP) and to observe diurnal IOP patterns for a short term. Patients and methods: Twenty six eyes of 16 patients with open angle glaucoma were included. After instruction and practice in using Icare® HOME, patients were asked to measure their IOP by themselves at home or in a sick room. Patients measured their IOP four times a day with a four hour interval between each measurement for three days. Patients repeated measurements until three successful measurements were obtained at each time. Intra-rater reliability was assessed calculating intraclass correlation coefficient (ICC) of the three measurements. Diurnal IOP patterns were assessed for three days. Results: No adverse events occurred. ICC of three measurements was 0.76 (95% confidence coefficient; 0.71 to 0.81). The median of the difference between the highest and the lowest IOP during a day was 4.26 mmHg (95% CI; 4.06 to 4.67). Repeatable patterns were not found in diurnal IOP for three days. Three out of ten patients who answered the questionnaire after measurements found difficulties in handling the device. Conclusions: Although Icare® HOME is safe and could be used for home monitoring of IOP, some patients had difficulties in using the instrument. Diurnal IOP patterns did not show repeatability during a short term.


Assuntos
Glaucoma de Ângulo Aberto/fisiopatologia , Pressão Intraocular , Monitorização Fisiológica , Adulto , Idoso , Feminino , Serviços de Assistência Domiciliar , Humanos , Masculino , Pessoa de Meia-Idade , Tonometria Ocular
15.
Nippon Ganka Gakkai Zasshi ; 120(9): 635-9, 2016 Sep.
Artigo em Japonês | MEDLINE | ID: mdl-30067002

RESUMO

Purpose: To evaluate the effects of trabeculotomy (TLO) combined with Schlemm's canal endothelium removal (SER) and deep sclerectomy (DS). Method: This retrospective study involved 131 adults eyes, diagnosed with glaucoma that were enrolled with at least 1 year follow-up after TLO. Fifty three eyes received TLO+SER+DS and 78 eyes underwent TLO+DS without SER. SER was performed as peeling of Schlemm's canal endothelium opening under the scleral flap. Surgical success was defined by the need for additional glaucoma surgery, or intraocular pressure (IOP) ≤20 mmHg (criterion A) and ≤16 mmHg (criterion B). Results: The occurrence rate of transient ocular hypertension (≥30 mmHg) was significantly less (p<0.001) in SER (3.8%) compared with Non-SER (21.8%). SER decreased IOP at 3 years without significant efficacy in terms of lowered IOP compared with Non-SER. At 3 years, Kaplan-Meier survival analysis revealed that the success rate of SER was higher than Non-SER for criterion A (p=0.008), but comparable for criterion B (p=0.06). Conclusions: SER was effective for reducing the rate of transient ocular hypertension in TLO and controlling IOP≤20 mmHg in adult eyes.


Assuntos
Endotélio/cirurgia , Esclera/cirurgia , Trabeculectomia , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento , Acuidade Visual
16.
Invest Ophthalmol Vis Sci ; 56(11): 6573-80, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26567476

RESUMO

PURPOSE: Optical coherence tomography (OCT) instruments do not embed a normative database from highly myopic normal (HMN) eyes. The abilities of three OCT instruments to detect early glaucoma with high myopia were compared using the two controls with or without high myopia. METHODS: A total of 52 early glaucomatous eyes (mean deviation > -6.0 dB) with high myopia (spherical equivalent ≤ -6.0 diopters [HMG]), 54 HMN eyes, and 90 nonhighly myopic normal (NHMN) eyes were enrolled. Each participant was imaged using Cirrus, RTVue, and Topcon 3D OCT to evaluate the thicknesses of the circumpapillary retinal nerve fiber layer (cpRNFL), the macular retinal nerve fiber layer (mRNFL), ganglion cell layer + inner plexiform layer (GCL/IPL), and mRNFL + GCL/IPL (GCC). The covariate-adjusted areas under the receiver operating characteristic curves (AUCs) for detecting HMG were compared among the instruments and between the two normal groups (HMN or NHMN). RESULTS: Highly myopic normal eyes showed higher AUCs for the temporal quadrant cpRNFL thickness but lower AUCs for the superior and inferior RNFL thicknesses compared with NHMN. We found the AUCs for the GCC thickness showed no significant difference between the two control groups, but the GCL/IPL and mRNFL thicknesses had differences. CONCLUSIONS: The abilities of the three OCT instruments to detect early glaucomatous eyes with high myopia were different if the normal eyes were associated with high myopia or not. A normative database that includes data from patients with high myopia should be established for accurate diagnosis of glaucoma with high myopia. (www.umin.ac.jp/ctr number, UMIN000006900.).


Assuntos
Glaucoma/diagnóstico , Miopia Degenerativa/diagnóstico , Tomografia de Coerência Óptica/métodos , Adulto , Estudos de Casos e Controles , Estudos Transversais , Diagnóstico Diferencial , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Disco Óptico/patologia , Células Ganglionares da Retina/patologia , Adulto Jovem
17.
Doc Ophthalmol ; 131(2): 115-24, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26078041

RESUMO

PURPOSE: In previous studies, we applied receiver operating characteristic curve analysis to the signal-to-noise ratio distributions in the signal and noise windows of multifocal VEP (mfVEP) response. The areas under the curve thus obtained (SNR-AUC) were found to quantitatively detect glaucomatous visual field damage. The present study evaluated the reproducibility of SNR-AUC and the Humphrey visual field (HVF) global indices in 37 eyes with primary open angle glaucoma (POAG; POAG group) and in 30 controls (control group) within a 2-year period. METHODS: The HVF SITA standard 24-2 and mfVEP were recorded at three separate sessions for each individual. The intersession variability for SNR-AUC, mean deviation (MD), and pattern standard deviation (PSD) was evaluated using the repeated measures of analysis of variance and Bland-Altman plots. The logarithmically converted coefficients of variation (CV) of PSD and SNR-AUC were compared between the control and POAG groups. Linear regression analyses were performed on the logarithmic CV of SNR-AUC against the average MD, PSD, and SNR-AUC. RESULTS: SNR-AUC in the POAG group was significantly lower and its CV was greater compared with the control group (P < 0.0001). MD value recorded at the third visit had significantly improved than that at the first visit in the control group (analysis of variance, P = 0.03), whereas PSD value was significantly worse in the POAG group (P = 0.024). In the POAG group, SNR-AUC CV increased as the glaucoma stage became more advanced when evaluated by any functional parameters tested (i.e., MD, PSD, or SNR-AUC). CONCLUSIONS: The SNR-AUC of mfVEP showed a high reproducibility in control group, whereas it fluctuated more in the POAG group according to the disease severity. MD in the control group and PSD in POAG group fluctuated among sessions during the 2-year period.


Assuntos
Potenciais Evocados Visuais/fisiologia , Glaucoma de Ângulo Aberto/fisiopatologia , Campos Visuais/fisiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Glaucoma de Ângulo Aberto/diagnóstico , Humanos , Pressão Intraocular , Masculino , Pessoa de Meia-Idade , Curva ROC , Reprodutibilidade dos Testes , Razão Sinal-Ruído , Tonometria Ocular , Testes de Campo Visual
19.
Glycobiology ; 20(4): 420-32, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19959702

RESUMO

Endo-beta-N-acetylglucosaminidases are thought to be key enzymes in the catabolism of asparagine-linked oligosaccharides. However, little is known about the enzymes of this type in basidiomycetes. We investigated endo-beta-N-acetylglucosaminidases in basidiomycetes using fluorescence-labeled glycoasparagines as substrates. Flammulina velutipes showed high activity and its enzyme was named endo-beta-N-acetylglucosaminidase FV (Endo FV). The enzyme purified from the fruiting bodies of F. velutipes was separated into two forms. Endo FV was specific for high mannose and hybrid-type oligosaccharides. The enzyme was remarkably less active against asparagine-linked oligosaccharides attached to glycoproteins. It transferred an asparagine-linked oligosaccharide to Glc, but not to Gal. cDNA of Endo FV was cloned. It was composed of a 996-bp open reading frame encoding 331 amino acid residues. A recombinant Endo FV expressed in Escherichia coli showed enzymatic activity. The Endo FV gene in the genome of F. velutipes had no introns. The gene encoding Endo FV showed little homology with genes of known endo-beta-N-acetylglucosaminidases. A chitinase active site motif existed in the deduced primary structure, indicating that Endo FV belongs to glycoside hydrolase family 18. The deduced amino acid sequence of Endo FV had regions conserved in class III chitinases from fungi though it showed little homology with the sequence of any other endo-beta-N-acetylglucosaminidases. A folding model of Endo FV indicated it to be homologous with the tertiary structure of Endo H which is quite similar in specificity for asparagine-linked oligosaccharides. This study suggests that Endo FV may become similar to Endo H in substrate specificity as a result of evolutionary convergence.


Assuntos
Flammulina/enzimologia , Manosil-Glicoproteína Endo-beta-N-Acetilglucosaminidase/química , Sequência de Aminoácidos , Asparagina/genética , Asparagina/metabolismo , Sequência de Bases , Sítios de Ligação/genética , Clonagem Molecular , DNA Complementar/genética , DNA Complementar/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Glicopeptídeos/genética , Glicopeptídeos/metabolismo , Glicoproteínas/genética , Glicoproteínas/metabolismo , Manose/genética , Manose/metabolismo , Manosil-Glicoproteína Endo-beta-N-Acetilglucosaminidase/genética , Manosil-Glicoproteína Endo-beta-N-Acetilglucosaminidase/metabolismo , Oligossacarídeos/química , Oligossacarídeos/genética , Oligossacarídeos/metabolismo , Especificidade por Substrato/genética
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