Objective To find an ideal animal model of acute respiratory distress syndrome (ARDS) through investigating the characteristics of three two-hit animal models of ARDS.Methods Forty-eight SD rats were randomly divided into 4 groups: Control group [2.5 mL/kg normal saline (NS) i.v.given at 0 min and 30 min];OA+OA group [0.5 mL/kg oleic acid (OA) i.v.given at 0 min and 30 min];LPS+LPS group [2.5 mg/kg lipopolysaccharide (LPS) i.v.given at 0 min and 30 min];and OA+LPS group [0.5 mL/kg OA i.v.given at 0 min and 2.5 mg/kg LPS,i.v.given at 30 min].The samples were collected at 5 h after the second drug injection.White blood cells count (WBC),polymorphonuclear leukocyte ratio (PMN%),total protein concentration,tumor necrosis factor α (TNF-α) level in bronchoalveolar lavage fluid (BALF),arterial blood gas analysis and lung wet-dry weight ratio (W/D) were measured,respectively.Pathological changes in the lung tissues were observed and histological scores were evaluated.Results Compared with those in the control group,PaCO2,WBC,PMN%,total protein concentration and TNF-α levels in BALF were significantly increased,while PaO2 was dramatically decreased (P<0.01) in the OA+OA,LPS+LPS and OA+LPS groups.The levels of protein concentration in BALF and lung W/D ratio in the OA+LPS group were significantly higher than these in the LPS+LPS group (P<0.05 for all),but had no statistically significant difference compared with these in the OA+OA group.The levels of WBC,PMN% and TNF-α in BALF in the OA+LPS group were significantly higher than those in the OA+OA group (P<0.05),but not significantly different from those in the LPS+LPS group.The most typical pathological changes and the highest pathological scores were found in the OA+LPS group.Conclusions All the three different methods including OA+OA,LPS+LPS,and OA+LPS can be used to establish “two-hit” animal models of acute respiratory distress syndrome.The “two-hit” animal model of acute respiratory distress syndrome induced by OA+LPS is more closer to clinical ARDS and is useful for studies on the pathophysiology of ARDS,and is an ideal “two-hit” animal model of ARDS.

Objective To observe the functional connectivity of attentional network in first-episode treatment-naive depressed patients with resting-state functional MR imaging (rfMRI),and to investigate the neuropathologic mechanism of attention dysfunction.Methods Eighteen first-episode treatment-naive depressed patients were collected in our hospital from August 2015 to March 2017,and 16 healthy controls matched with age,gender and education were chosen at the same time period.All subjects accepted rfMRI.Pearson correlation analysis was performed on all the time series values of the two regions of interest (ROIs),and their correlation coefficient was obtained.Fisher z transformation was performed to reflect the functional connection strength of the two ROIs through z scores.Results As compared with healthy controls,depressed patients showed abnormal enhancement on functional connectivity of the attentional network in the left anterior cingulate and supplementary motor area (z scores:0.21 ±0.10 vs.0.13±0.09,P=0.029),right basal ganglia region and dorsolateral prefrontal cortex (z scores:0.18±0.12 vs.0.10±0.08,P=0.048),right frontal eye field and intraparietal suleus (z scores:0.19± 0.12 vs.0.10±0.05,P=0.006),right frontal eye field and nucleus ceruleus (z scores:0.18±0.13 vs.0.09± 0.07,P=0.018).Conclusion Abnormal functional connectivity of attentional network exists extensively in first-episode treatment-naive depressed patients,which may be due to attention impairment in depressed patients.

Objective:To observe the effect of escitalopram combined with repetitive transcranial magnetic stimulation (rTMS) on efficacy and attention function in patients with first-episode unipolar depression.Methods:Fifty-two first-episode initial-naive unipolar depression patients were enrolled in Department of Neurology of Guangzhou First People's Hospital from March 2022 to April 2023 were chosen. They were randomly allocated to active stimulation group ( n=27) and sham stimulation group ( n=25); both were treated with escitalopram, and active treatment or sham treatment in the left dorsolateral prefrontal cortex (DLPFC) were given for 4 weeks (5 d per week, 20 d totally). Before treatment and 2 and 4 weeks after treatment, Hamilton Depression Rating Scale (HAMD)-24 was used to evaluate depressive symptoms, and Birmingham Cognitive Screening Scale-Chinese (BCoS-C) was used to evaluate the attention function. Results:(1) In terms of depressive symptoms: HAMD-24 scores of the active stimulation group 2 and 4 weeks after treatment (20.63±2.73, 15.85±2.43) were significantly lower than those before treatment (25.74±2.68, P<0.05); HAMD-24 scores of sham stimulation group 4 weeks after treatment were also significantly lower than those before treatment ([20.48±2.33] vs. [25.80±2.57], P<0.05); HAMD-24 scores of the active stimulation group 2 and 4 weeks after treatment were significantly lower than those of sham stimulation group ( P<0.05). (2) In terms of auditory attention indicators: total correct number (selective attention) in active stimulation group 4 weeks after treatment was significantly larger than that before treatment (51.74±1.38 vs. 47.48±1.60), and the sustained index (sustained attention) was significantly lower than that before treatment (0.74±0.71 vs. 4.37±1.15, P<0.05); total correct number in active stimulation group 4 weeks after treatment was significantly larger than that in sham stimulation group (48.00±1.66), and the sustained index was significantly lower than that in sham stimulation group (3.72±1.28, P<0.05). Conclusion:Combined with escitalopram, rTMS can more effectively mitigate the depressive symptoms in first-episode unipolar depression patients, and depressive symptoms improve more quickly than attentional function.