RÉSUMÉ
Objectives:To investigate the predictive effect of regional homogeneity (ReHo) from resting-state functional magnetic resonance imaging (rs-fMRI) in acute phase on memory function of chronic phage in ischemic stroke patients and the effects of residual learning (REL) on the predictive performance of machine learning models.Methods:From June 2019 to June 2021, rs-fMRI data of one-week after stroke (acute phase) were collected from 35 first-time ischemic stroke patients, and their memory scores were assessed by the Rey auditory verbal learning test (RAVLT) at 6 months after stroke (chronic phase). Using ReHo from rs-fMRI data in acute phase of ischemic stroke patients, the support vector regression (SVR) and the REL-based SVR (REL-SVR) were constructed to predict the patients’ memory scores at 6 months after stroke, and the performance of the two models was compared using Pearson correlation coefficient.Results:Based on the ReHo from acute phase, the correlation coefficient between the predicted values and the true scores from the SVR model was r=0.524, P=0.001, while the correlation coefficient obtained by the REL-SVR model was r=0.671, P<0.001. Brain regions with relatively higher weights such as Temporal_Pole_Mid_R (weight value: 1.03), Temporal_Mid_R(weight value: 1.03), Temporal_Inf_R (weight value: 1.03), Occipital_Mid_R (weight value: 0.57), Frontal_Mid_L (weight value: 0.32), Frontal_Sup_Medial_L (weight value: 0.53), SupraMarginal_L (weight value: 1.54), Calcarine_L (weight value: 0.65), Lingual_L (weight value: 0.58), Cuneus_L (weight value: 0.65), Precuneus_L (weight value: 0.83), cerebellum(weight value>1.0) made larger contributions to the prediction model. Conclusions:ReHo in the acute-phase can effectively predict memory in the chronic phase of ischemic stroke patients. Furthermore, REL can improve the performance of the traditional SVR model and achieve higher predictive accuracy.
RÉSUMÉ
Objective:To explore the different functional connectivity of right caudate nucleus between adults with high myopia and normal vision controls.Methods:The resting-state functional magnetic resonance imaging(fMRI) data were collected from twenty-five high myopia(HM group) and twenty-seven normal vision subjects(NC group). Right caudate nucleus and their subregions(anterior and posterior subregions included) were used as seeds to perform seed-based functional connectivity (FC)analyses at group level under three different frequency bands: convention (0.010~0.080 Hz), slow-5(0.010~0.027 Hz) and slow-4(0.027~0.073 Hz).Results:(1)Compared with NC group, FC of right caudate nucleus with left middle occipital gyrus(MNI: x=-48, y=-84, z=9), left fusiform gyrus(MNI: x=-30, y=-63, z=-12), and right middle frontal gyrus(MNI: x=39, y=12, z=39) were stronger in HM group(all P<0.05, Alphasim Corrected). (2)In HM group, these changed FC were mainly detected in the anterior subregion of right caudate nucleus.(3)The increased FC of right caudate nucleus and its anterior subregion with left middle occipital in HM group were mainly reflected in the frequency band of slow-4(all P<0.05, Alphasim Corrected). Conclusion:The right caudate nucleus in adults with high myopia may play compensatory roles in visual perception and visual attention by enhancing its functional connectivity with visual and visual attentional brain areas.
RÉSUMÉ
Objective To explore the differences of macrostructural and microstructural and their correlations in brain white matter (WM) between left-and right-handed adults.Methods Structural magnetic resonance imaging (sMRI) and diffusion tensor imaging (DTI) were performed on twenty-three left-handed (LH) and thirty-two right-handed (RH) healthy subjects.The WM volume,fractional anisotropy (FA) and mean diffusivity (MD) were mearsured and compared between the two groups by using the voxel-based morphometry (VBM) and voxel-based analysis (VBA) methods.Results (1) LH adults showed lower WM volume than RH adults in bilateral splenium of corpus callosum (SC) (Left:x=-15,y=-57,z =13.5,t=-5.160;Right:x=18,y=-42,z=12,t=-3.654;P＜0.001).Compared with the RH adults,the FA values in WM of the left postcentral gyrus (PoCG) (x =-24,y =-46,z =54) and the above left insula (INS) (x =-36,y =-12,z =20) increased (P＜ 0.001),as well as the average FA values,the average length and number of streamlines in WM tracts increased (P＜0.05) in LH adults.Compared with the RH adults,the MD values in the right HIP (x=24,y=-34,z=-2) decreased(P＜0.001),as well as the average MD values decreased,and the average length in WM tracts increased (P＜0.05) in LH adults.(2)There was positive correlation between FA and the volume of right splenium of corpus callosum in LH and RH adults (LH:r=0.716,RH:r=0.471,P＜0.05).There was negative correlation between FA and MD in the left PoCG (LH:r=-0.769,RH:r=-0.841),left INS (LH:r=-0.775,RH:r=-0.744) and right HIP (LH:r=-0.842,RH:r=-0.742) in LH and RH adults (all P＜0.05).Conclusion There are differences in both macrostructure and microstructure of white matter in several brain regions and WM tracts between left-handed and right-handed people,and correlations between these measures were also observed.
RÉSUMÉ
Objective To investigate the efficacy and safety of 5-aminolaevulinic acid-photodynamic therapy (ALA-PDT) in cervical condyloma acuminatum. Methods Forty-five patients with cervical condyloma acuminatum topically applied 10% ALA thermal gel followed by PDT. The treatment was repeated 14 days later if the lesion was not completely removed. Totally, 1 - 4 treatment sessions were given. Thirty-five patients with cervical condyloma acuminatum who received CO2 laser treatment served as the control. All patients were followed up for 12 weeks. Results Complete remission was achieved in 97.8% (44/45) of patients with cervical condyloma acuminatum treated by ALA-PDT, and among the 44 cured patients, 3 were treated by 1 cycle of ALA-PDT, 6 by 2 cycles, 20 by 3 cycles, and 15 by 4 cycles. The lesions of condyloma acuminatum were removed after 1 session of CO2 laser treatment in 30 patients, and after repeated treatments in 5 patients, with the complete remission rate being 100% (35/35). The overall recurrence rate calculated for the whole followup period in patients treated with ALA-PDT was significantly lower than that in patients treated with CO2 laser [6.8% (3/44) vs 31.4% (11/35), x2 = 6.497, P ＜ 0.05]. However, no significant difference in complete remission rate was found between the two groups (P ＞ 0.05). Almost all the patients in ALA-PDT group presented with pain of bythus during illumination, but no severe side effects or scar formation was observed. In patients treated with CO2 laser, adverse reactions mainly included bleeding, erosion, shallow ulcer and even scar formation. Conclusions Topical ALA-PDT is effective and safe for the treatment and reduction in recurrence of condyloma acuminatum, and may serve as a therapeutic option for cervical condyloma acuminatum.
RÉSUMÉ
Objective To investigate the effect and safety of photodynamic therapy (PDT) with topical aminolevulinic acid (ALA) in moderate to severe acne. Methods Seventy patients with moderate to severe acne were randomly divided into two groups, one group was treated with topical ALA-PDT for 1-3 sessions with an interval of 2 weeks, the other group received oral isotretinoin 10 mg twice a day for 6 weeks. Patients were evaluated for efficacy on week 2, 4 and 6 after the initial treatment. A 3-month follow up was performed to monitor adverse events following the end treatment. Results The total effective rate was 97.1% in ALA-PDT group after 1-3 sessions of treatment, 80.0% in the control group on week 6, and the difference was significant between the two groups (P<0.05). Acne lesions tended to recur more slightly with a longer remission period in ALA-PDT group than in the control group. A temporary and local pigmentation was observed in some patients treated with ALA-PDT, but no scar was noticed. Conclusion Topical ALA-PDT is a simple and effective treatment option for moderate to severe acne with mild side effects.
RÉSUMÉ
Objective To investigate the optimal concentration and incubation time of 5-aminole-vulinic acid (ALA) in photodynamic therapy of acne vulgaris. Methods Thirty patients with facial acne vulgaris were equally divided into two groups. In group 1, ALA (10%)cream was applied to acne lesions and protoporphyrin Ⅸ (PpⅨ) fluorescence was examined visually and spectroscopically at 1, 2, 3, 4 and 5 hours. In group 2, ALA cream of 3%, 5% and 10% was applied to lesions in the right cheek, left cheek, and forehead, respectively, of the same patient and incubated for 3 hours followed by photodynamie diagnosis and quantification of fluorescence intensity; clinical outcome and side effects were analyzed. Results Strong brick red PpⅨ fluorescence was observed in inflammatory papules, pustules, and cysts alter applica-tion of 10% ALA cream and irradiation with excitation light. The relative intensity of Ppix fluorescence was 1.3, 4.3, 5.1 and 5.8 in comedones, inflammatory papules, pustules and cysts, respectively, and it increased with the severity of lesions. A higher intensity of PpⅨ fluorescence was noted in patients with longer incu-bation period (3, 4 or 5 hours) compared with those with shorter incubation period (1 or 2 hours), and the difference was significant (P < 0.05). However, there was no significant difference in PpⅨ fluorescence intensity among lesions receiving ALA of different concentrations (P > 0.05). The overall clearance rate was 73% (11/15) after two courses of ALA-photodynamic therapy (PDT) in group 2. Side effects mainly included mild to moderate erythema, swelling and little exudation (occasionally). A transient pigmentation was observed in 2 patients. Neither ulceration nor scarring was noted. Conclusions ALA-PDT is suitable for the manage-ment of acne vulgaris mainly characterized by inflammatory papules, pustules and cysts. The results strongly suggest that 3% and 3 hours are the optimal concentration and incubation time of ALA in PDT of acne vulgaris.
RÉSUMÉ
Objective To evaluate the usefulness of protoporphyrin Ⅸ (PpIX) fluorescence diagnosis after topical application of 5-aminolevulinic acid (ALA) in human papillomavirus (HPV) related diseases.Methods Photodynamic diagnosis (PDD) was conducted in 36 patients clinically diagnosed as genital condylomata acuminata. PpIX fluorescence was observed 2 hours following the application of 5-aminole-vulinic acid 20% cream on the lesions and subclinical lesions of these patients. Biopsy samples were resected from the lesions, subclinical lesions, and normal skin area (0.5 cm and 2 cm around the lesions) of the patients,and subjected to histopathological examination and microarray analysis for HPV DNA. Acetowhitening test was also performed at the four skin areas. Results Of the 36 patients, 30 were diagnosed as condylomata acuminata, 5 as bowenoid papulosis, and 1 as keratosis seborrheica by histopathological examination.Brick-red fluorescence of PpIX was observed in both lesions and subclinical lesions of all patients with condylomata acuminata and those with bowenoid papulosis, in subclinical lesions of 28 patients, at the area 0.5 cm around the lesions of 17 patients, and at the area 2 cm around the lesions of 5 patients. Acetowhitening and HPV DNA were also positive in lesions and subclinical lesions of patients with condylomata acuminata and those with bowenoid papulosis. Mucosa, inflammatory infiltration area and erosion tissue were prone to develop nonspecific PpIX fluorescence. Conclusions ALA-PpIX-mediated PDD can be used for the diag-nosis of clinical and subclinical HPV infection, as well as 'the location of latent HPV infection, however, it'snot recommended to be used in mucosa, inflammatory infiltration area or erosion tissue.
RÉSUMÉ
BACKGROUND: Recently, many researches suggest that transcranial magnetic stimulation has effect on learning and memory. Moreover, the effects of magnetic fields simulating electroencephalogram (EEG) rhythm on memory have been investigated.OBJECTIVE: To explore the effect of magnetic field simulating EEG rhythm on memory retrieval ability and its mechanism.DESIGN: Randomized controlled study.SETTING: Department of Medical Imaging, Tianjin Medical University,and School of Precision Instrument & Photoelectronic Engineering, Tianjin University.MATERIALS: The experiment was conducted at the Electroscopic Center of TianjSn Medical University and Laboratory of Biomedical Engineering Department of Tianjin University from February 2002 to February 2004.Totally 25 Wistar rats and 5 domestic cats were selected from the Experimental Animal Center of Tianjin Medical University.INTERVENTIONS: All the 25 Wister rats were randomly divided into 5 group, 4 experimental groups and one control group with 5 rats in each group. Magnetic field simulating EEG rhythm was used to stimulate Wistar rats in the 4 experimental groups, but the time and frequency rate were different. Group 1 was stimulated by weak magnetic field with frequency in α rhythm (10 Hz); Group 2 was stimulated by weak magnetic field with frequency in β rhythm (20 Hz); Group 3 was stimulated by weak magnetic field with frequency changing from α to β rhythm; and Group 4 was stimulated by weak magnetic field with frequency changing from β to α rhythm. Memory retrieval ability and changes of neurotransmitters in the brain were recorded. Five cats were treated with weak magnetic field with frequency changing from α to β rhythm for 20 minutes, and the changes of EEG power spectra before and after stimulation were compared.information from long-term memory was tested with modified cross maze;hippocampus of the rats was measured with high performance liquid multiple-channel electrophysiological recording device.Comparison of memory retrieval ability: Memory retrieval ability in Group 2 and Group 4 was obviously higher than that in control group 5 hours after Content ofdopamine (DA) in rats' cerebral hippocampus: It was obviously higher in the 4 experimental groups than in control group [(192.72±18.66,percentage of power spectrum of β rhythm was increased after stimulation [(23.0±3.4, 14.2±1.3) %.].CONCLUSION: Most of the weak magnetic fields simulating EEG rhythm of human brain can decrease the retrieval of long-term memory, but magnetic field with special rhythm may increase memory retrieval ability.All the effects are related to the release of hippocampal neurotransmitters which is mediated by the change of intracellular calcium ([Ca2+]i) and synaptic vesicle.
RÉSUMÉ
In this paper the response characteristic of the nerve fiber to the modulation magnetic field induction is studied by using the method of numeric simulation. It is found that the nerve fiber is sensitive to the low frequency modulated signal but not to the high frequency carrier wave. A simulative EEG signal generator is developed according to the change of EEG rhythm during the sleep. The simulative EEG square wave is modulated by high-frequency magnetic impulse. The modulation magnetic field is coupled into the rabbit's brain to study the influence of magnetic stimulation on the discharge of 5-hydroxytryptamine (5-HT) nerve cell. The experiment results demonstrate that discharge frequency of median raphe nuclei related to sleep changes significantly and the discharge becomes slow, which shows that magnetic stimulation can inhibit electrical activity of 5-HT nerve cell and provide a new way to improve insomnia.
Sujet(s)
Animaux , Humains , Lapins , Encéphale , Métabolisme , Physiologie , Simulation numérique , Électroencéphalographie , Champs électromagnétiques , Électrophysiologie , Neurones , Physiologie , Noyaux du raphé , Métabolisme , Physiologie , Sérotonine , Métabolisme , Sommeil , Physiologie , Troubles de l'endormissement et du maintien du sommeil , MétabolismeRÉSUMÉ
Objective To study the effect of different attention states on auditory ERP and EEG power in normal subjects. Methods In three different states such as passive attention,active attention with target counting and active attention without target counting,EEG were recorded using oddball paradigm in 8 normal subjects while the test tones were presented;Then the peak-peak amplitude and latency of ERP were evaluated and the EEG power spectra were observed. Results The condition of active attention with target counting resulted in the smallest peak-peak amplitude of P 2-N 1 and the largest one of P 3-N 2,and it led to the increment of EEG power at the frequency of 10Hz,while the latencies did not differ among the three different attention states. Conclusion Reduced P 2-N 1 amplitude and increased P 3-N 2 amplitude reflected the allocation changes of attention resource in different states,and increased EEG power reflected more energy consumption in the process of recognition and memory,but the latency was relatively stable and not affected significantly by subject's attention condition.
RÉSUMÉ
Objective To explore the effect and the mechanism of modulated magnetic pulse fields on memory retention and retrieval ability of rats. Methods The influence of different pulsed magnetic fields on memory performance of rats was evaluated by using cross maze test, the morphological changes of neurons and nerve synapses in the hippocampus of rats were observed by the electronic microscopy. Results The 20 Hz modulated-pulse magnetic field impaired the memory retrieval ability and the memory retention significantly after 1 hour of exposure of the rats to it ( P 0.05). These influences on nerve tissues were also observed in rats underwent the 10Hz modulated magnetic stimulation, manifested as an initial increase in ability of memory in the first 24 hours after the stimulation, but no significant difference from the control was found. The influence of magnetic fields on memory depended on what the rats remembered. Conclusion Changes in the nerve synapses may be a main factor of mechanisms of the influence of pulse magnetic fields on memory ability of rats.
RÉSUMÉ
Objective To investigate the effects of 5-aminolaevulinic acid-photodynamic therapy (ALA-PDT) on precancerous changes and carcinoma of the skin in situ. Methods Fifteen patients with actinic keratosis, 3 patients with erythroplasia of Queyrat and 8 patients with Bowen′s disease were given topical ALA followed by PDT. Results The clearance was achieved in 17 lesions of 15 patients with actinic keratosis, 2 patients with erythroplasia of Queyrat and 7 patients with Bowen′s disease by topical ALA-PDT. The recurrence rates were 13.33%, 0 and 14.28% for actinic keratosis, erythroplasia of Queyrat and Bowen′s disease, respectively. Conclusions Topical ALA-PDT is a simple, effective and new treatment with lower recurrent rates, no scar formation and excellent cosmetic results for precancerous changes and carcinoma in situ of the skin, especially for the large and multifocal lesions located on the face and external genitalia.