RESUMO
We have previously shown that repetitive induction of long-term potentiation (LTP) by glutamate (100 µM, 3 min, three times at 24-hr intervals) provoked long-lasting synaptic enhancement accompanied by synaptogenesis in rat hippocampal slice cultures, a phenomenon termed RISE (repetitive LTP-induced synaptic enhancement). Here, we examined the role of Ca2+ -permeable (CP) AMPA receptors (AMPARs) in the establishment of RISE. We first found a component sensitive to the Joro-spider toxin (JSTX), a blocker of CP-AMPARs, in a field EPSP recorded from CA3-CA1 synapses at 2-3 days after stimulation, but this component was not found for 9-10 days. We also observed that rectification of AMPAR-mediated current appeared only 2-3 days after stimulation, using a whole-cell patch clamp recording from CA1 pyramidal neurons. These findings indicate that CP-AMPAR is transiently expressed in the developing phase of RISE. The blockade of CP-AMPARs by JSTX for 24 hr at this developing phase inhibited RISE establishment, accompanied by the loss of small synapses at the ultrastructural level. These results suggest that transiently induced CP-AMPARs play a critical role in synaptogenesis in the developing phase of long-lasting hippocampal synaptic plasticity, RISE.
Assuntos
Cálcio/metabolismo , Hipocampo/fisiologia , Potenciação de Longa Duração/fisiologia , Receptores de AMPA/metabolismo , Sinapses/fisiologia , Animais , Animais Recém-Nascidos , Potenciais Pós-Sinápticos Excitadores/fisiologia , Hipocampo/citologia , Técnicas de Cultura de Órgãos , Ratos , Ratos WistarRESUMO
BACKGROUND: Toritsukuroi is a particular type of behaviour intended to save face or preserve appearances. Clinicians often observe toritsukuroi in people with dementia, but current knowledge about this behaviour is based on clinicians' empirical knowledge rather than on observational studies. This study was designed to clarify which behaviours are related to toritsukuroi based on neuropsychological examinations. METHODS: The subjects were 91 outpatients with dementia. Verbal responses, with the exceptions of 'I don't know' and erroneous answers, were recorded by certificated clinical psychologists and analyzed by qualitative study procedures. A qualitative study was separately conducted by two researchers to identify themes and types of reactions. The themes found through content analysis were organized and labelled by a senior psychiatrist. RESULTS: Among the patients, 41.8% verbally responded in way to 'keep up appearances'. Six distinct thematic categories were identified through conventional content analysis: (i) refuting sudden questions; (ii) disclosing trait; (iii) disclosing experience; (iv) demonstrating slight hesitation; (v) appealing to indifference; and (vi) other. CONCLUSIONS: All the responses that we defined as being toritsukuroi reflect a denial of acquired cognitive impairment. Further study is needed to clarify the association between toritsukuroi and either cognitive function or disease specificity.
Assuntos
Disfunção Cognitiva/psicologia , Demência/psicologia , Vergonha , Demência/diagnóstico , Feminino , Humanos , Masculino , Pesquisa Qualitativa , Classe SocialRESUMO
Conductive polymers facilitate the electrical current flow through the transfer of electrons and holes. They show promise for novel photo-functional materials in photovoltaics. However, substantial electrostatic interactions between electron donors and acceptors induce polymer aggregation, limiting moldability and conductivity. In this study, robust donor polymers with high heat resistance were synthesized by bonding triphenylamine (TPA) derivatives and formaldehyde to phenolic groups. Resulting TPA-based phenolic polymers exhibited flexible structures and fluorescence due to charge transfer with acceptor molecules. Furthermore, TPA-based phenolic polymers' capacity to distinguish acceptor molecule sizes correlated with their molecular weight, reflecting upon donor-acceptor interactions. This novel optical trait in phenolic polymers holds potential for electronic components and conductive materials.
RESUMO
Among several characteristics seen in gait of hemiplegic patients after stroke, symmetry is known to be an indicator of the degree of impairment of walking ability. This paper proposes a control method for a wearable type lower limb motion assist robot to realize spontaneous symmetric gait for these individuals. This control method stores the motion of the unaffected limb during swing and then provides motion support on the affected limb during the subsequent swing using the stored pattern to realize symmetric gait based on spontaneous limb swing. This method is implemented on the robot suit HAL (Hybrid Assistive Limbs). Clinical tests were conducted in order to assess the feasibility of the control method. Our case study involved participation of one chronic stroke patient who was not able to flex his right knee. As a result, the walking support for hemiplegic leg provided by the HAL improved the subject's gait symmetry. The feasibility study showed promising basis for the future clinical study.
Assuntos
Hemiplegia/fisiopatologia , Aparelhos Ortopédicos , Robótica/instrumentação , Caminhada/fisiologia , Desenho de Equipamento , Marcha/fisiologia , Hemiplegia/etiologia , Humanos , Perna (Membro)/fisiopatologia , Masculino , Pessoa de Meia-Idade , Amplitude de Movimento Articular , Acidente Vascular Cerebral/complicaçõesRESUMO
BACKGROUND: Soluble fibrin complex (SFC), composed of fibrin monomer and fibrinogen derivatives, is known to exist in the circulating blood in patients with thrombosis. Its detection and quantification are useful for obtaining information about the condition and degree of intravascular coagulation in early-stage thrombosis, but there is no rapid method to measure SFC in plasma for clinical use. METHODS: We obtained a monoclonal antibody that specifically reacts with SFC, with desAA-fibrin as the immunogen, and developed a rapid and sensitive latex immunoturbidimetric assay (LIA) using latex-immobilized anti-SFC monoclonal antibody. The assay system was based on the increase in turbidity induced by the reaction of the latex-immobilized anti-SFC monoclonal antibody with SFC in plasma, and the assay procedure was fully automated on a Hitachi 911 analyzer. RESULTS: The method had an analytical range of 3-300 mg/L. Intra- and interassay precision studies indicated that this system provided reproducible data (CVs <3.0% and <2.0%, respectively). The assay detection limit was <0.5 mg/L. There was no interference from bilirubin (up to 440 mg/L), hemoglobin (up to 9.6 g/L), Intralipid (up to 10%), D-dimer (up to 200 mg/L), and rheumatoid factor (up to 470 000 IU/L). SFC concentrations in plasma from patients with thrombotic diseases [mean (SD), 48.9 (57.6) mg/L; n = 160) were significantly higher than those in plasma from healthy individuals [1.8 (2.1) mg/L; P <0.001; n = 304]. CONCLUSION: In terms of linearity, precision, and sensitivity, the LIA, performed on a Hitachi 911 automated analyzer, may be useful for measurement of SFC in plasma.