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1.
Epilepsia ; 65(5): 1304-1313, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38469885

RESUMEN

OBJECTIVE: Individuals with Dravet syndrome (DS) exhibit progressive gait disturbance. No quantitative studies have been conducted to evaluate the effectiveness of medication for gait disturbance. Therefore, the aim of this study was to evaluate the effectiveness of levodopa for pathological gait in people with DS using three-dimensional gait analysis (3DGA). METHODS: Nine individuals with DS, ages 6-20 years, participated in a crossover study of levodopa and were randomly assigned to the levodopa precedence or no levodopa precedence group. Levodopa/carbidopa hydrate was prescribed at a dose of 5 mg/kg/day (body weight <60 kg) or 300 mg/day (body weight ≥60 kg). The medication was taken for 4-6 weeks (4-week washout period). 3DGA was performed three times before the study, with and without levodopa. A mixed-effects model was used to evaluate the effectiveness of levodopa. The primary outcome was the change in the Gait Deviation Index (GDI). In addition, spatiotemporal gait parameters, 6-minute walking distance (6MD), and balance were evaluated. The correlation between the effectiveness of levodopa and age or gait performance before starting levodopa was analyzed. RESULTS: Levodopa improved the GDI by 4.2 points, (p = .029), 6MD by 52 m (p = .002), and balance test result by 4.1 mm (p = .011) in participants with DS. No severe adverse events were observed, with the exception of one participant, who exhibited fever and consequently stopped taking levodopa. Levodopa was more effective in younger participants with a higher baseline gait performance. SIGNIFICANCE: Our randomized crossover trial showed that levodopa has the potential to improve gait disturbance in people with DS.


Asunto(s)
Estudios Cruzados , Epilepsias Mioclónicas , Trastornos Neurológicos de la Marcha , Levodopa , Humanos , Levodopa/uso terapéutico , Masculino , Femenino , Adolescente , Adulto Joven , Niño , Trastornos Neurológicos de la Marcha/tratamiento farmacológico , Trastornos Neurológicos de la Marcha/etiología , Epilepsias Mioclónicas/tratamiento farmacológico , Análisis de la Marcha , Resultado del Tratamiento , Carbidopa/uso terapéutico , Marcha/efectos de los fármacos , Combinación de Medicamentos
2.
Pediatr Res ; 2024 Apr 20.
Artículo en Inglés | MEDLINE | ID: mdl-38643264

RESUMEN

BACKGROUND: This cross-sectional study compared body composition and motor function between children who were born large for gestational age (LGA) and those born appropriate for gestational age (AGA) and to investigate the association between gait quality and other variables. METHODS: Body composition was determined using a bioelectrical impedance analyzer. Motor functions were assessed using one-leg standing time, timed up-and-go test, five times sit-to-stand test, and three-dimensional gait analysis. We compared the results between two groups. We performed multiple regression analysis to evaluate the association between gait deviation index and variables of LGA, fat mass index, and motor functions (adjusted for age and sex). RESULTS: Children aged 6-12 years who were born LGA at term (n = 23) and those who were born AGA at term (n = 147) were enrolled. The LGA group had a higher fat mass index (2.9 vs. 2.2, p = 0.006) and lower gait deviation index (91.4 vs. 95.4, p = 0.011) than the AGA group. On multiple regression analysis, gait deviation index was associated with being LGA and fat mass index. CONCLUSIONS: In school-aged children who were born LGA, monitoring increased fat mass index and decreased gait deviation index could lessen the risk of metabolic syndrome and reduced gait function. IMPACT: Children aged 6-12 years who were born large for gestational age (LGA) at term showed a higher fat mass index and lower gait deviation index than those who were born appropriate for gestational age at term. No significant differences in balance function or muscle strength were observed between groups. On multiple regression analysis, gait deviation index was associated with being LGA at birth and fat mass index. In school-aged children who were born LGA, monitoring increased fat mass index and decreased gait deviation index could lessen the risk of metabolic syndrome and reduced gait function.

3.
J Infect Chemother ; 30(7): 626-632, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38272262

RESUMEN

BACKGROUND: Information regarding the status of surgical antimicrobial prophylaxis (SAP) in Japanese hospitals is lacking. This study aimed to explore the status of SAP prescriptions for surgeries and adherence to Japanese SAP guidelines. METHODS: From February to July 2020, a 1-day multicentre point prevalent survey was conducted at 27 hospitals in Aichi Prefecture, Japan. Patients prescribed SAP were included in this study. The appropriateness of the SAP was evaluated based on the guidelines for selection of antimicrobials and their duration. Surgery was defined as appropriate when all the items were appropriate. RESULTS: A total of 728 patients (7.1 %; 728/10,199) received antimicrobials for SAP. Among them, 557 patients (76.5 %, 557/728) underwent the surgeries described in the guidelines. The overall appropriateness of all surgeries was 33.9 % (189/557). The appropriate selection of antimicrobial before/during and after surgery and their durations were 67.5 % (376/557), 67.5 % (376/557), and 43.3 % (241/557), respectively. The overall appropriateness ranged from 0 % (0/37, oral and maxillofacial surgery) to 58.7 % (88/150, orthopaedic surgery) and 27.7 % (36/130, community hospitals with 400-599 beds) to 47.2 % (17/36, specific hospitals). Cefazolin was the most prevalent antimicrobial prescribed before/during (55.5 %, 299/539), and after (45.1 %, 249/552) surgery. In total, 101 oral antimicrobials were prescribed postoperatively. CONCLUSIONS: SAP adherence by specific surgical fields and hospitals was shown in this study. Intensive intervention and repeated surveillance are necessary to improve SAP prescriptions in Japanese hospitals.


Asunto(s)
Profilaxis Antibiótica , Adhesión a Directriz , Hospitales , Infección de la Herida Quirúrgica , Humanos , Japón , Profilaxis Antibiótica/estadística & datos numéricos , Profilaxis Antibiótica/métodos , Profilaxis Antibiótica/normas , Infección de la Herida Quirúrgica/prevención & control , Adhesión a Directriz/estadística & datos numéricos , Hospitales/estadística & datos numéricos , Masculino , Femenino , Persona de Mediana Edad , Anciano , Antibacterianos/uso terapéutico , Adulto , Guías de Práctica Clínica como Asunto , Anciano de 80 o más Años , Pueblos del Este de Asia
4.
Artículo en Inglés | MEDLINE | ID: mdl-37606963

RESUMEN

OBJECTIVES: To efficiently detect somatic UBA1 variants and establish a clinical scoring system predicting patients with pathogenic variants in VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) syndrome. METHODS: Eighty-nine Japanese patients with clinically suspected VEXAS syndrome were recruited [81 males and 8 females; median onset age (IQR) 69.3 years (62.1-77.6)]. Peptide nucleic acid-clamping PCR (PNA-PCR), regular PCR targeting exon 3 clustering UBA1 variants, and subsequent Sanger sequencing were conducted for variant screening. Partitioning digital PCR (pdPCR) or targeted amplicon deep sequencing (TAS) was also performed to evaluate the variant allele frequency (VAF). We developed our clinical scoring system to predict UBA1 variant-positive and ­negative patients and assessed the diagnostic value of our system using receiver operating characteristic (ROC) curve analysis. RESULTS: Forty patients with reported pathogenic UBA1 variants (40/89, 44.9%) were identified, including a case having a variant with VAF of 1.7%, using a highly sensitive method. Our clinical scoring system considering >50 years of age, cutaneous lesions, lung involvement, chondritis, and macrocytic anaemia efficiently predicted patients with UBA1 variants (the area under the curve for the scoring total was 0.908). CONCLUSIONS: Genetic screening with the combination of regular PCR and PNA-PCR detected somatic UBA1 variants with high sensitivity and specificity. Our scoring system could efficiently predict patients with UBA1 variants.

5.
Int Immunol ; 34(8): 421-434, 2022 07 26.
Artículo en Inglés | MEDLINE | ID: mdl-35689594

RESUMEN

Antigen-combining sites of the camelid heavy-chain antibody variable domain (VHH) are constructed by three complementarity-determining regions (CDR1, CDR2 and CDR3). We prepared cDNA using mRNA extracted from peripheral lymphocytes of alpacas that had been non-immunized or immunized with human serum albumin (HSA). The VHH gene fragments encoding the amino-terminal half-containing CDR1 as well as CDR2 and the carboxy-terminal half-containing CDR3 were amplified independently by PCR, and then full-length VHH gene fragments were generated by overlap extension PCR and cloned into the phagemid vector. This protocol, referred to as CDR shuffling, allowed us to construct an alpaca VHH phage display library possessing repertoires different from those naturally occurring in animals. We asked, first, whether this library was able to provide the functional VHH fragments against HSA, an immunized antigen, and obtained 29 anti-HSA VHH clones, 41% possessed KD values of lower than 10-8 M, 5 of which had KD values of 10-10 M. We also obtained VHH clones against non-immunized protein antigens such as cardiac troponin T and I, Ebola virus glycoprotein 1 and human immunoglobulin G by biopanning. We compared the amino acid sequences and affinities and found that 43% of VHHs had KD values of less than 10-8 M, although those having KD values of 10-10 M were unavailable. These results suggested that the CDR-shuffled VHH phage display library could potentially provide VHHs against non-immunized protein antigens with similar levels of affinities to those against immunized antigens.


Asunto(s)
Bacteriófagos , Camélidos del Nuevo Mundo , Anticuerpos de Dominio Único , Animales , Antígenos , Bacteriófagos/genética , Camélidos del Nuevo Mundo/genética , Biblioteca de Genes , Humanos , Cadenas Pesadas de Inmunoglobulina/genética , Anticuerpos de Dominio Único/química , Anticuerpos de Dominio Único/genética
6.
Epilepsy Behav ; 145: 109341, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37451070

RESUMEN

PURPOSE: To investigate the effects of an original education program on patients with epilepsy (PWE). The effects on knowledge about epilepsy, attitude to epilepsy, depression scales, and quality of life were investigated. METHOD: Thirty-five PWE participated in a lecture-style educational program using an original knowledge-oriented textbook. All patients were administered a total of four rating scales: the Knowledge about Epilepsy Scale (KES), the Attitude toward Epilepsy Scale (AES), and the Japanese version of the Quality of Life in Epilepsy Inventory (QOLIE-31-P), the Beck Depression Inventory (BDI). The KES and AES of patients (pKES and pAES) were compared to those of medical students (St) and residents (Rd). RESULTS: After education, pKES improved and showed significant differences among pre-and post-education and six months later. Before education, pKES was inferior to St and Rd. However, after education, pKES changed and became superior to St and Rd. Six months later, the advantage was lost, but not significantly. PAES also improved after education, with significant differences before, after, and six months later after education. PAES was statistically inferior to St and Rd before education, but the difference disappeared after education, and the effect persisted after six months. The non-depressed (BDI < 20) and depressed groups (BDI â‰§ 20) improved in the KES after education. About the AES, the non-depressive group has a statistical tendency, but not the depressive group. At six months, the depressed group's AES is significantly lower than the non-depressed group. CONCLUSION: While correct knowledge about epilepsy can improve attitudes and perceptions of epilepsy in PWE, special measures are needed for PWE with depression.


Asunto(s)
Depresión , Epilepsia , Humanos , Depresión/etiología , Calidad de Vida , Japón , Escolaridad
7.
Clin Rehabil ; 37(8): 1111-1118, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-36604801

RESUMEN

OBJECTIVE: To compare walking efficiency, and associated physical function, between children, with and without developmental coordination disorder trait. DESIGN: Cross-sectional study. SETTING: The study was conducted in a Medical and Rehabilitation Center for Developmental Disabilities in Okazaki, Japan. SUBJECTS: The study included 286 children, 6-12 years of age, with and without developmental coordination disorder trait. Developmental coordination disorder trait was defined by a score below the -1 standard deviation on the Japanese version of the Developmental Coordination Disorder Questionnaire. Based on this criterion, 45 children (28 boys) were classified into the developmental coordination disorder trait group and the other 241 (115 boys) in the control group. MEASURES: The following physical function outcomes were measured: single leg stance test; step length variability; and walking efficiency, measured using the 2-min walk test. Logistic regression analysis was used to determine the association between developmental coordination disorder trait and lower walking efficiency and physical function. RESULTS: Compared to the control group, the developmental coordination disorder group showed lower walking efficiency (P = 0.026), higher step length variability (P = 0.047), and shorter single leg stance test (P = 0.001). Developmental coordination disorder was independently associated with walking efficiency (odds ratio, 1.03; 95% confidence interval [CI], 1.001-1.061; P = 0.041) and single leg stance test (odds ratio, 0.99; 95% CI, 0.978-0.996; P = 0.006), but not to step length variability, age, and sex. CONCLUSIONS: Lower walking efficiency increases energy expenditure in children with developmental coordination disorder trait. Interventions to improve walking efficiency could improve the physical function and participation of these children.


Asunto(s)
Trastornos de la Destreza Motora , Masculino , Humanos , Niño , Trastornos de la Destreza Motora/diagnóstico , Estudios Transversales , Caminata , Encuestas y Cuestionarios , Prueba de Paso , Marcha
8.
Int J Mol Sci ; 24(13)2023 Jun 28.
Artículo en Inglés | MEDLINE | ID: mdl-37445977

RESUMEN

The properties of the variable domain of heavy-chain (VHH) antibodies are particularly relevant in cancer therapy. To isolate tumor cell-specific VHH antibodies, VHH phage libraries were constructed from multiple tumor cells. After enriching the libraries against particular tumor cell lines, a next-generation sequencer was used to screen the pooled phages of each library for potential antibody candidates. Based on high amplification folds, 50 sequences from each library were used to construct phylogenetic trees. Several clusters with identical CDR3 were observed. Groups X, Y, and Z were assigned as common sequences among the different trees. These identical groups over the trees were considered to be cross-reactive antibodies. To obtain monoclonal antibodies, we assembled 200 sequences (top 50 sequences from each library) and rebuilt a combined molecular phylogenetic tree. Groups were categorized as A-G. For each group, we constructed a phagemid and determined its binding specificity with tumor cells. The phage-binding results were consistent with the phylogenetic tree-generated groups, which indicated particular tumor-specific clusters; identical groups showed cross-reactivity. The strategy used in the current study is effective for screening and isolating monoclonal antibodies. Specific antibodies can be identified, even when the target markers of cancer cells are unknown.


Asunto(s)
Anticuerpos Monoclonales , Cadenas Pesadas de Inmunoglobulina , Filogenia , Cadenas Pesadas de Inmunoglobulina/genética , Línea Celular Tumoral , Biblioteca de Genes , Biblioteca de Péptidos
9.
Small ; 18(25): e2200113, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35589386

RESUMEN

Changes in the statistical properties of data as a system approaches a critical transition is studied intensively as early warning signals, but their application to materials science, where phase transitions-a type of critical transition-are of fundamental importance, are limited. Here, a critical transition analysis is applied to time-series data from a microscopic 3D ordered soft material-blue phase liquid crystals (BPLC)-and demonstrates that phase transitions that are invisible under ambient conditions can be visualized through the choice of appropriate early warning indicators. After discussing how a phase transition affects the statistical properties in a system with a Landau-de Gennes type free energy potential, the predicted changes are experimentally observed at the two types of phase transitions that occur in a BPLC: the isotropic to simple cubic, and simple cubic to body-centered cubic transitions. In particular, it is shown that the skewness of the intensity distribution inverts its sign at the phase transition, enabling temporally and spatially resolved mapping of phase transitions. This approach can be easily adapted to a wide variety of material systems and microscopy techniques, providing a powerful tool for studying complex critical transition phenomena.

10.
Pediatr Int ; 64(1): e15001, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34562291

RESUMEN

BACKGROUND: We aimed to investigate electroencephalography (EEG)-functional magnetic resonance imaging (fMRI) findings to elucidate the interictal epileptiform discharge (IED)-related functional alterations in deep brain structures and the neocortex in childhood epilepsy with centrotemporal spikes (CECTS). METHODS: Ten children with CECTS (median age 8.2 years), referred to our hospital within a year of onset, were eligible for inclusion. They underwent EEG-fMRI recording during sleep. Llongitudinal evaluations, including medical examinations, intelligence tests, and questionnaires about developmental disabilities, were performed. The initial evaluation was performed at the same time as the EEG-fMRI, and the second evaluation was performed over 2 years after the initial evaluation. RESULTS: Three children were unable to maintain sleep during the EEG-fMRI recording, and the remaining seven children were eligible for further assessment. All patients showed unilateral-dominant centrotemporal spikes during scans. One patient had only positive hemodynamic responses, while the others had both positive and negative hemodynamic responses. All patients showed IED-related hemodynamic responses in the bilateral neocortex. For deep brain structures, IED-related hemodynamic responses were observed in the cingulate gyrus (n = 4), basal ganglia (n = 3), thalamus (n = 2), and default mode network (n = 1). Seizure frequencies at the second evaluation were infrequent or absent, and the longitudinal results of intelligence tests and questionnaires were within normal ranges. CONCLUSIONS: We demonstrated that IEDs affect broad brain areas, including deep brain structures such as the cingulate gyrus, basal ganglia, and thalamus. Deep brain structures may play an important role in the pathophysiology of CECTS.


Asunto(s)
Epilepsia Rolándica , Encéfalo , Niño , Electroencefalografía/métodos , Humanos , Imagen por Resonancia Magnética/métodos
11.
Org Biomol Chem ; 19(1): 146-150, 2021 01 06.
Artículo en Inglés | MEDLINE | ID: mdl-33095213

RESUMEN

We designed and synthesized a medium-firm drug-candidate library of cryptand-like structures possessing a randomized peptide linker on the bacteriophage T7. From the macrocyclic library with a 109 diversity, we obtained a binder toward a cancer-related protein (Hsp90) with an antibody-like strong affinity (KD = 62 nM) and the binding was driven by the enthalpy. The selected supramolecular ligand inhibited Hsp90 activity by site-specific binding outside of the well-known ATP-binding pocket on the N-terminal domain (NTD).


Asunto(s)
Bacteriófago T7/química , Diseño de Fármacos , Éteres Cíclicos/química , Éteres Cíclicos/metabolismo , Proteínas HSP90 de Choque Térmico/metabolismo , Bases de Schiff/química , Bases de Schiff/metabolismo , Bibliotecas de Moléculas Pequeñas/química , Bibliotecas de Moléculas Pequeñas/metabolismo , Sitios de Unión
12.
Pediatr Res ; 87(3): 529-535, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31493771

RESUMEN

OBJECTIVE: The objective of this study was to describe a novel amplitude-integrated electroencephalography (aEEG) pattern in infants with hypoxic-ischemic encephalopathy (HIE) and to assess the clinical significance. METHODS: The aEEG traces of infants with HIE who were treated with therapeutic hypothermia (TH) from 2012 to 2017 were analyzed. A pseudo-sawtooth (PST) pattern was defined as a periodic increase of the upper and/or lower margin of the trace on aEEG without showing seizure activities on conventional EEG (CEEG). RESULTS: Of the 46 infants, 6 (13%) had the PST pattern. The PST pattern appeared following a flat trace or a continuous low-voltage pattern and was followed by a burst-suppression pattern. On CEEG, the PST pattern consists of alternating cycles of low-voltage irregular activities and almost flat tracing. The PST pattern was associated with neuroimaging abnormalities and with various degrees of neurodevelopmental outcomes. Positive predictive values of the PST or worse pattern for adverse outcomes were high at 12 h after birth. CONCLUSION: A novel aEEG background pattern in infants with HIE was reported. The PST pattern likely indicates a suppressed background pattern and may be linked to unfavorable outcomes. Further multicenter validation study is needed to clarify its clinical significance.


Asunto(s)
Ondas Encefálicas , Encéfalo/fisiopatología , Electrocardiografía , Hipoxia-Isquemia Encefálica/diagnóstico , Enfermedades del Recién Nacido/diagnóstico , Procesamiento de Señales Asistido por Computador , Femenino , Humanos , Hipotermia Inducida , Hipoxia-Isquemia Encefálica/fisiopatología , Hipoxia-Isquemia Encefálica/terapia , Recién Nacido , Enfermedades del Recién Nacido/fisiopatología , Enfermedades del Recién Nacido/terapia , Masculino , Valor Predictivo de las Pruebas , Factores de Tiempo , Resultado del Tratamiento
13.
Exp Brain Res ; 238(12): 2887-2895, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-33057869

RESUMEN

Williams syndrome (WS) is a genetically based neurodevelopmental disorder characterized by intellectual disability and impaired visuospatial recognition. The aim of this study was to analyze the gait characteristics of WS children with impaired visuospatial recognition using a three-dimensional gait analysis (3DGA) to clarify the gait adaptation needed to compensate for it. 3DGA was performed in 8 WS children with impaired visuospatial recognition (mean age, 11.8 years) and 9 age-, sex-, height-, and weight-matched controls. Clinical data, fundamental motor tests, and gait variables while walking on a flat surface and walking up a mat were compared between the two groups, and the correlations between variables were analyzed in the WS children. WS children showed impairment of balance function without muscle weakness. In walking on a flat surface, the WS group showed reduced walking speed, short step length, increased variability of step length, increased knee flexion throughout the stance phase, increased horizontal pelvic range of motion (ROM), and a low Gait Deviation Index and a high Gait Profile Score, which are indices of gait quality. In walking up a mat, the WS group showed further reduced walking speed and decreased sagittal hip flexion and ankle dorsiflexion ROM in the swing phase. Impaired balance function was significantly correlated with increased variability of step length and decreased sagittal ankle dorsiflexion ROM in the swing phase. The detailed gait pattern of WS children with impaired visuospatial recognition was presented. These findings show that impaired visuospatial recognition and balance function contribute to gait adaptation.


Asunto(s)
Análisis de la Marcha , Síndrome de Williams , Fenómenos Biomecánicos , Niño , Marcha , Humanos , Rango del Movimiento Articular , Caminata
14.
Gan To Kagaku Ryoho ; 47(6): 997-999, 2020 Jun.
Artículo en Japonés | MEDLINE | ID: mdl-32541183

RESUMEN

An 89-year-old woman with recurrent hormone receptor-positive and HER2-negative breast cancer was treated with fulvestrant-palbociclib combination therapy. However, 3 months after therapy initiation, she presented to our emergency room with dyspnea and fever and was admitted to our hospital because of respiratory failure. After radiological and microbiological evaluation, she was diagnosed with palbociclib-related pneumonitis. Accordingly, corticosteroids were administered, and the patient exhibited initial clinical and radiological improvement. However, pneumonitis recurred following corticosteroid tapering; her condition did not improve with high-dose intravenous corticosteroid administration, leading to death. Palbociclib- related pneumonitis is rare, but clinicians need to pay attention to this potentially lethal adverse event.


Asunto(s)
Neoplasias de la Mama , Enfermedades Pulmonares Intersticiales , Piperazinas/efectos adversos , Piridinas/efectos adversos , Anciano de 80 o más Años , Protocolos de Quimioterapia Combinada Antineoplásica , Supervivencia sin Enfermedad , Estradiol , Femenino , Humanos , Enfermedades Pulmonares Intersticiales/inducido químicamente , Recurrencia Local de Neoplasia , Receptor ErbB-2
15.
J Biol Chem ; 293(18): 7008-7016, 2018 05 04.
Artículo en Inglés | MEDLINE | ID: mdl-29523691

RESUMEN

Rheumatoid factors (RFs) are autoantibodies against the fragment-crystallizable (Fc) region of IgG. In individuals with hematological diseases such as cryoglobulinemia and certain B cell lymphoma forms, the RFs derived from specific heavy- and light-chain germline pairs, so-called "stereotypic RFs," are frequently produced in copious amounts and form immune complexes with IgG in serum. Of note, many structural details of the antigen recognition mechanisms in RFs are unclear. Here we report the crystal structure of the RF YES8c derived from the IGHV1-69/IGKV3-20 germline pair, the most common of the stereotypic RFs, in complex with human IgG1-Fc at 2.8 Å resolution. We observed that YES8c binds to the CH2-CH3 elbow in the canonical antigen-binding manner involving a large antigen-antibody interface. On the basis of this observation, combined with mutational analyses, we propose a recognition mechanism common to IGHV1-69/IGKV3-20 RFs: (1) the interaction of the Leu432-His435 region of Fc enables the highly variable complementarity-determining region (CDR)-H3 to participate in the binding, (2) the hydrophobic tip in the CDR-H2 typical of IGHV1-69 antibodies recognizes the hydrophobic patch on Fc, and (3) the interaction of the highly conserved RF light chain with Fc is important for RF activity. These features may determine the putative epitope common to the IGHV1-69/IGKV3-20 RFs. We also showed that some mutations in the binding site of RF increase the affinity to Fc, which may aggravate hematological diseases. Our findings unravel the structural basis for germline-encoded antibody autoreactivity.


Asunto(s)
Autoanticuerpos/química , Autoanticuerpos/inmunología , Células Germinativas , Factor Reumatoide/metabolismo , Sustitución de Aminoácidos , Afinidad de Anticuerpos , Sitios de Unión , Regiones Determinantes de Complementariedad , Cristalografía por Rayos X , Epítopos/inmunología , Humanos , Interacciones Hidrofóbicas e Hidrofílicas , Inmunoglobulina G/química , Inmunoglobulina G/inmunología , Mutagénesis , Conformación Proteica , Receptores Fc , Factor Reumatoide/química , Factor Reumatoide/inmunología , Relación Estructura-Actividad
16.
Chembiochem ; 20(21): 2729-2737, 2019 11 04.
Artículo en Inglés | MEDLINE | ID: mdl-30973187

RESUMEN

Antibody-drug conjugates (ADCs), which consist of three components, antibody, linker, and payload, can function as "magic bullets". These conjugates offer the ability to target drug delivery to specific cells, based on cell-specific recognition and the binding of an antigen by a monoclonal antibody (mAb). In particular, by delivering a cytotoxic payload to cancer cells, ADCs are expected to provide a breakthrough in oncology treatments by providing a way to increase efficacy and decrease toxicity, in comparison with traditional chemotherapeutic treatments. The development of ADC therapeutics has dramatically progressed in the past decade and two ADCs have been approved and used as anticancer drugs in the clinic. However, several critical issues regarding the performance of ADCs are still being discussed and investigated. Indeed, in the past few years, several groups have reported that, changing the number and position of the drug payloads in the ADCs, affects the pharmacokinetics, drug release rates, and biological activity. The use of conventional heterogeneous conjugation methods for ADC preparation results in the drug/antibody ratio and connecting position of the payload having stochastic distributions. Therefore, it is important to investigate how these potential problems can be circumvented through site-specific conjugation. Herein, various site-specific chemical conjugation strategies with native mAbs that are currently used for the production of ADCs, including residue-selective labeling for generating ADCs, disulfide rebridging, and affinity-peptide-mediated site-specific chemical conjugation technologies, are reviewed and described.


Asunto(s)
Anticuerpos Monoclonales/inmunología , Antígenos/inmunología , Antineoplásicos/inmunología , Inmunoconjugados/inmunología , Neoplasias/inmunología , Animales , Anticuerpos Monoclonales/química , Anticuerpos Monoclonales/uso terapéutico , Especificidad de Anticuerpos/inmunología , Antígenos/metabolismo , Antineoplásicos/química , Antineoplásicos/uso terapéutico , Sitios de Unión , Humanos , Inmunoconjugados/química , Inmunoconjugados/uso terapéutico , Neoplasias/metabolismo , Neoplasias/terapia , Trastuzumab/química , Trastuzumab/inmunología , Trastuzumab/uso terapéutico
17.
Bioconjug Chem ; 30(3): 698-702, 2019 03 20.
Artículo en Inglés | MEDLINE | ID: mdl-30606013

RESUMEN

Artificially modified IgG molecules are increasingly utilized in industrial and clinical applications. In the present study, the method of chemical conjugation by affinity peptide (CCAP) for site-specific chemical modification has been developed by using a peptide that bound with high affinity to human IgG-Fc. This method enabled a rapid modification of a specific residue (Lys248 on Fc) in a one-step reaction under mild condition to form a stable amide bond between the peptide and Fc. The monovalent peptide-IgG conjugate not only maintained complete antigen binding but also bound to Fc receptors (FcRn, FcγRI, and FcγRIIIa), indicating that it is a suitable conjugate form that can be further developed into highly functional antibody therapeutics. CCAP was applied for the preparation of an antibody-drug conjugate and a bispecific antibody to demonstrate the usefulness of this method.


Asunto(s)
Anticuerpos/química , Anticuerpos/uso terapéutico , Inmunoconjugados/química , Péptidos/química , Animales , Humanos , Inmunoglobulina A/química , Inmunoglobulina G/química , Roedores , Trastuzumab/química , Trastuzumab/uso terapéutico
18.
Angew Chem Int Ed Engl ; 58(17): 5592-5597, 2019 04 16.
Artículo en Inglés | MEDLINE | ID: mdl-30854738

RESUMEN

The need for atom-precise biomolecule modification, and particularly the irreversible formation of covalent bonds to specific amino acids in proteins, has become an essential issue in the fields of pharmaceuticals and chemical biology. For example, antibody-drug conjugates (ADCs) are increasingly common entries into the clinical oncology pipeline. Herein, we report a new method of affinity peptide mediated regiodivergent functionalization (AJICAP™) that enables the synthesis of ADCs from native IgG antibodies. We succeeded in introducing thiol functional groups onto three lysine residues in IgGs using Fc affinity peptide reagents without antibody engineering. A cytotoxic molecule was then connected to the newly introduced thiol group, and both a surface plasmon resonance binding assay and in vivo xenograft mouse model results showed that the resulting ADC could selectively target and kill HER2-positive cells. Our strategy provides a new approach for constructing complex antibody-derived biomolecules.


Asunto(s)
Inmunoconjugados/química , Péptidos/metabolismo , Humanos
19.
Bioconjug Chem ; 29(6): 1866-1871, 2018 06 20.
Artículo en Inglés | MEDLINE | ID: mdl-29792678

RESUMEN

A peptide-type covalent binder for a target protein was obtained by combinatorial screening of fluoroprobe-conjugated peptide libraries on bacteriophage T7. The solvatochromic fluoroprobe works as a bait during the affinity selection process of phage display. To obtain the targeted covalent binder, the bait in the selected consensus peptide was altered into a reactive warhead possessing a sulfonyl fluoride. The reaction efficiency and site/position specificity of the covalent conjugation between the binder and the target protein were evaluated by liquid chromatography-tandem mass spectrometry (LC-MS/MS), and rationalized by a protein-ligand docking simulation.


Asunto(s)
Colorantes Fluorescentes/metabolismo , Glutatión Transferasa/metabolismo , Biblioteca de Péptidos , Péptidos/metabolismo , Schistosoma japonicum/enzimología , Animales , Bacteriófago T7/química , Bacteriófago T7/metabolismo , Técnicas de Visualización de Superficie Celular , Cromatografía Liquida , Colorantes Fluorescentes/química , Humanos , Simulación del Acoplamiento Molecular , Péptidos/química , Unión Proteica , Schistosoma japonicum/metabolismo , Esquistosomiasis Japónica/parasitología , Espectrometría de Masas en Tándem
20.
Epilepsia ; 59(2): 440-448, 2018 02.
Artículo en Inglés | MEDLINE | ID: mdl-29315514

RESUMEN

OBJECTIVE: To clarify longitudinal changes in white matter microstructures from the onset of disease in patients with West syndrome (WS) of unknown etiology. METHODS: Diffusion tensor imaging (DTI) was prospectively performed at onset and at 12 and 24 months old in 17 children with WS of unknown etiology. DTI was analyzed using tract-based spatial statistics (TBSS) and tract-specific analysis (TSA) of 13 fiber tracts, and fractional anisotropy (FA) and mean diffusivity (MD) were compared with those of 42 age-matched controls. Correlations of FA and MD with developmental quotient (DQ) at age 24 months were analyzed. Multiple comparisons were adjusted for using the false discovery rate (q-value). RESULTS: TBSS analysis at onset showed higher FA and lower MD in the corpus callosum and brainstem in patients. TSA showed lower MD in bilateral uncinate fasciculi (UF) (right: q < 0.001; left: q = 0.03) at onset in patients. TBSS showed a negative correlation between FA at onset and DQ in the right frontal lobe, whereas FA at 24 months old exhibited a positive correlation with DQ in the diffuse white matter. MD for bilateral UF at 24 months old on TSA correlated positively with DQ (q = 0.04, both). SIGNIFICANCE: These findings may indicate the existence of cytotoxic edema in the immature white matter and dorsal brainstem at onset, and subsequent alterations in the diffuse white matter in WS of unknown etiology. Microstructural development in the UF might play important roles in cognitive development in WS.


Asunto(s)
Edema Encefálico/diagnóstico por imagen , Discapacidades del Desarrollo/fisiopatología , Espasmos Infantiles/diagnóstico por imagen , Sustancia Blanca/diagnóstico por imagen , Anisotropía , Encéfalo/diagnóstico por imagen , Tronco Encefálico/diagnóstico por imagen , Estudios de Casos y Controles , Preescolar , Discapacidades del Desarrollo/complicaciones , Imagen de Difusión Tensora , Femenino , Lóbulo Frontal/diagnóstico por imagen , Humanos , Lactante , Estudios Longitudinales , Masculino , Estudios Prospectivos , Espasmos Infantiles/complicaciones , Espasmos Infantiles/fisiopatología
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