Résumé
Aging is a crucial factor influencing postural stability control and contributing to frequent falls, yet its underlying mechanisms remain incompletely understood. This study aims to explore the effects of aging on postural stability control by comparing differences in postural stability and node strength of electroencephalogram (EEG) brain network between elderly and young people under the conditions of congruent and incongruent visual-vestibular sensory inputs. Eighteen elderly volunteers without neuromuscular disorders and eighteen young individuals participated in the present study. Virtual reality (VR) technology was employed to manipulate visual rotation stimuli (clockwise and counterclockwise), and a horizontal rotating platform was used for vestibular rotation stimuli (clockwise). Based on the directional disparity of sensory input in the horizontal plane, visual-vestibular input consistency was categorized as congruent and incongruent. Postural stability was assessed by the center of pressure (COP) trajectory, and EEG signals were collected and analyzed using directed network analysis to observe EEG brain network node connectivity strength. The results revealed that, under conditions of incongruent visual-vestibular sensory inputs, the elderly exhibited significantly inferior postural stability performance in terms of COP anterior-posterior (Y-axial) sway speed, total path length, anterior-posterior and medial-lateral sample entropy, compared to the young adults. Moreover, the node connectivity strength of visual cortex in the elderly was notably higher, while node connectivity strength of superior temporal cortex was significantly lower than that in the young adults. These findings suggest that the elderly have a heightened reliance on visual information in postural control and an impaired ability to cope with sensory conflicts arising from incongruent visual-vestibular sensory inputs, leading to compromised postural stability. The outcomes of this study hold significant implications for future assessments of balance function in the elder and fall prevention trainings.
Sujets)
Jeune adulte , Humains , Sujet âgé , Adolescent , Posture , Équilibre postural , Vieillissement , EncéphaleRésumé
<p><b>OBJECTIVE</b>To explore the effects of blocking TCR-CD3 and B7-CD28 signals on immune function of mice with chronic GVHD by using TJU103 and CTLA4-Ig.</p><p><b>METHODS</b>On the basis of foregoing murine model of chronic GVHD, according to interference modes after infusion 6×10 spleen cells of donor mice, the recipients were divided into 5 groups: blank control, cGVHD, TJU103 interference, CTLA4-Ig interference and TJU103+CTLA4-Ig interference groups. The score of clinical manifestation and tissue histopathology were used to evaluate the effects of all the interferences on chronic GVHD.</p><p><b>RESULTS</b>TJU103 and CTLA4-Ig could not influence the formation of the mouse chimera. The analysis of Kaplan survival curve of mice with chronic GVHD showed that the CTLA4-Ig and TJU103+CTLA4-Ig reduced the incidence of chronic GVHD, the TJU103 could delay the occurrence of chronic GVHD, but all the interference factors could not change the severity of chronic GVHD.</p><p><b>CONCLUSION</b>TJU103 can delay the onset time of chronic GVHD, and the CTLA4-Ig can reduce the incidences of cGVHD, the combining use of TJU103 and CTLA4-Ig can significantly reduce the incidence of chronic GVHD, but can not change the severity of chronic GVHD.</p>
Sujets)
Animaux , Souris , Abatacept , Cellules présentatrices d'antigène , Antigènes CD , Antigènes de différenciation , Antigène CTLA-4 , Maladie chronique , Maladie du greffon contre l'hôte , Immunoconjugués , Souris de lignée C57BL , Lymphocytes TRésumé
This study was aimed to explore the change characteristics of cell differentiation antigen (CD) on bone marrow (BM) granulocytes in patients,with megaloblastic anemia (MA). In combination with BM cell morphology, hemogram, level of blood serum folic acid, level of Vit B(12), cell genetics and biological examination data, the BM granulocytes differentiation antigens in 13 patients with MA were detected by flow cyto metry and analyzed retrospectively, in order to summarize the variation characteristics of CD13, CD33 and CD15 expressed on myeloid cells in patient with MA, including forward scatter light (FSC) and side scatter light (SSC) signal intensity, then these findings were compared with that in normal healthy persons. The results showed that the expression rates of CD13, CD15 and CD33 on granulocytic in patients with MA and normal healthy persons were (44.53 ± 16)%, (96.16 ± 2.67)%, (80.81 ± 14.71)% and (62.33 ± 11.02)%, (99.53 ± 0.46)%, (70.00 ± 7.81)% respectively, in which the expression rate of CD13 and CD15 in patients with MA decreased (P < 0.01), while the expression rate of CD33 increased (P < 0.01). The mean fluorescence intensity (MFI) of CD13, CD15, CD33, SSC and FSC in MA patients and normal healthy persons were 3.39 ± 1.41, 14.29 ± 6.59, 1.95 ± 0.94, 478.78 ± 70.43, 633.46 ± 75.53 and 5.12 ± 1.15, 20.67 ± 5.13, 1.04 ± 0.17, 332.00 ± 38.16, 537.00 ± 16.70 respectively, in which the MFI of CD13 and CD15 on granulocytes in MA patients decreased (P < 0.01),while the MFI of FSC,SSC and CD33 increased (P < 0.01 and P < 0.05). It is concluded that not only the morphology of BM granulocytes in patents with MA shows dysmaturity, but the expressing feature of differentiation antigens on BM granulocytes in MA patients also displays dysmaturity.These findings will contribute to the clinical diagnosis of MA patients.
Sujets)
Adulte , Sujet âgé , Femelle , Humains , Mâle , Adulte d'âge moyen , Anémie mégaloblastique , Diagnostic , Allergie et immunologie , Métabolisme , Antigènes CD , Métabolisme , Études cas-témoins , Granulocytes , Métabolisme , Études rétrospectivesRésumé
<p><b>OBJECTIVE</b>To determine the contents of NOS and endogenous CO in the penile corpus cavernosum of Wistar rat models of hyperthyroid and hypothyroid, to detect the effects of thyroid hormone and endogenous CO on rat penile erection, and to further investigate the influence of thyroid hormone on human penile erection.</p><p><b>METHODS</b>Fifty 3-month-old male Wistar rats were randomly and equally divided into 5 groups: a hyperthyroid, a hyperthyroid treatment, a hypothyroid, a hypothyroid treatment and a control group. The contents of NOS and CO were detected by ultraviolet spectrophotometry.</p><p><b>RESULTS</b>Compared with the controls, the content of NOS was significantly decreased in both the hyperthyroid and the hypothyroid groups (P < 0.01), even lower in the latter than in the former (P < 0.01), and so was the content of CO (P < 0.01), lower in the former than in the latter (P < 0.01). After treatment, the levels of NOS and CO were both elevated in either the hyperthyroid or the hypothyroid group, with no significant difference from that of the controls (P > 0.05).</p><p><b>CONCLUSION</b>The contents of NOS and CO in the penile corpus cavernosum decrease with the imbalance of thyroid hormones, but return to normal once the imbalance is corrected. Under the same conditions, hypothyroid inflicts more damage on penile erection than hyperthyroid.</p>