[Long-term high-fat diet's impact on synaptic plasticity in the visual cortex and hippocampus neurons: an experimental study]

Objective: To investigate the effects and mechanisms of long-term high-fat diet on synaptic plasticity in the visual cortex and hippocampus neurons of juvenile mice. Methods: This was an experimental study. Twenty-four 4-week-old male C57BL/6J mice were randomly divided into two groups, using a randomized numerical table, with 12 mice in each group. The ND group was fed a normal diet, while the HFD group was fed a high-fat diet. After 12 weeks of feeding, mouse body weight, body fat percentage, glucose tolerance, and blood lipid levels were recorded. Six mice from each group were randomly selected using a randomized numerical table, and long-term potentiation (LTP) in the lateral geniculate nucleus (LGN)-primary visual cortex binocular zone (V1B area) and hippocampus CA3-CA1 were recorded in vitro. Field excitatory postsynaptic potentials (fEPSPs) were measured, and the normalized fEPSP slope was calculated to evaluate changes in cortical synaptic plasticity. Subsequently, brain tissue was collected for Golgi staining to observe the development of pyramidal neurons in layers Ⅱ-Ⅲ of the primary visual cortex and CA1 region of the hippocampus, and changes in dendritic spine morphology and quantity were compared. The remaining six mice from each group were euthanized, and brain tissue was collected for transmission electron microscopy to observe ultrastructural changes in the visual cortex V1B area and hippocampus CA1 region neurons. Independent samples t-test was used for statistical analysis. Results: After 12 weeks of feeding, the body weight of mice in the HFD group was (29.17±1.63) g, significantly lower than the ND group which was (37.99±6.87) g (t=4.33, P<0.001). The body fat percentage in the HFD group was 1.09%±0.22%, which was higher than the ND group with 0.85%±0.09% (t=2.50, P=0.032). HFD mice showed a significant increase in blood glucose level 30 minutes after glucose injection, reaching (17.80±3.94) mmol/L, compared to the ND group with (23.10±1.48) mmol/L (t=3.07, P=0.013). At 60 minutes after glucose injection, the difference in blood glucose levels between the ND group [(13.58±2.39) mmol/L] and the HFD group [(23.70±3.56) mmol/L] was statistically significant (t=5.40, P<0.001). Subsequently, both groups showed a decline in blood glucose levels, and at 120 minutes after glucose injection, the blood glucose level in the ND group decreased to (8.50±1.05) mmol/L, while the HFD group remained at a higher level of (16.03±4.17) mmol/L, showing a statistically significant difference (t=3.91, P=0.004). The serum total cholesterol levels in the ND and HFD groups were (4.08±0.35) mmol/L and (10.80±0.90) mmol/L, respectively, with the HFD group higher than the ND group (t=15.23, P<0.001). However, there was no significant difference in triglyceride levels (P>0.05). The high-density lipoprotein cholesterol level in the ND group was (2.12±0.57) mmol/L, while in the HFD group, it was (1.28±0.15) mmol/L, with the HFD group lower than the ND group (t=3.15, P=0.014). Non-high-density lipoprotein cholesterol level in the HFD group was (11.06±1.46) mmol/L, significantly higher than the ND group with (2.28±0.43) mmol/L (t=12.88, P<0.001). In the hippocampal CA3-CA1 pathway, the fEPSP slope increased by 239.1%±88.8% of baseline in the ND group, while in the HFD group, it was only 147.6%±31.6% of baseline, indicating lower LTP compared to the ND group (t=7.20, P<0.001). For the LGN-V1 pathway, the fEPSP slope increased by 204.8%±67.0% of baseline in the ND group, while in the HFD group, it was 121.1%±15.7% of baseline, showing reduced LTP compared to the ND group (t=9.11, P<0.001). Regarding the visual cortex, in the V1B area of the ND group, the number of dendritic spines per 10 μm was (1.31±1.14), while in the HFD group, it was (0.77±0.43), demonstrating a significant decrease in dendritic spine density (t=3.45, P<0.001). The proportion of mature dendritic spines in the ND group was 69.98%, while non-mature dendritic spines accounted for 30.02%. In contrast, the HFD group had 45.76% mature dendritic spines and 54.24% non-mature dendritic spines. Regarding changes in hippocampal CA1 pyramidal neurons, the cell bodies and axons were not damaged, but HFD group neurons exhibited simplified dendritic structures with reduced branching. The number of dendritic spines per 10 μm was (10.25±3.84) in the HFD group and (25.22±8.21) in the ND group, indicating significantly lower dendritic spine density in the HFD group (t=12.42, P<0.001). The proportion of mature dendritic spines in the ND group was 70.88%, while non-mature dendritic spines accounted for 29.12%. In contrast, the HFD group had 47.37% mature dendritic spines and 52.63% non-mature dendritic spines. Moreover, the ultrastructure of neurons in the visual cortex V1B area and hippocampus CA1 region of HFD mice showed evident damage, with disrupted cell structures, swollen and vacuolated mitochondria, reduced or even disappeared mitochondrial cristae, and decreased synaptic quantity with damaged structure. Conclusions: Long-term high-fat diet in juvenile mice leads to abnormal development and functional maturation of synapses in the visual cortex and hippocampal regions. Dendrites, as the foundation of synaptic structures, undergo abnormal development, which can cause alterations in synaptic plasticity of related neural circuits.

Nanomechanical probing of bacterial adhesion to biodegradable Zn alloys

Bacterial infections on implants cause an inflammatory response and even implant failure. Bacterial adhesion is an initial and critical step during implant infection. The prevention of bacterial adhesion to implant materials has attracted much attention, especially for biodegradable metals. A deep understanding of the mechanisms of bacterial adhesion to biodegradable metals is urgently needed. In this work, a bacterial probe based on atomic force spectroscopy was employed to determine the bacterial adhesion to Zn alloy, which depended on surface charge, roughness, and wettability. Negative surface charges of Zn, Zn-0.5Li, and 316L generated electrostatic repulsion force towards bacteria. The surface roughness of Zn-0.5Li was significantly increased by localized corrosion. Bacterial adhesion forces on Zn, Zn-0.5Li, and 316L were 325.2 pN, 519.1 pN, and 727.7 pN, respectively. The density of attached bacteria (early-stage bacterial adhesion) on these samples exhibited a positive correlation with the bacterial adhesion force. The bacterial adhesion force and adhesion work provide a quantitative determination of the interactions between bacteria and biodegradable alloys. These results provide a deeper understanding of early bacterial adhesion on Zn alloys, which can further guide the antibacterial surface design of biodegradable materials for clinical application.

[C-reactive protein is associated with impaired working capacity in Chinese patients with ankylosing spondylitis in paid employment: the real-world evidence from Smart-phone SpondyloArthritis Management System]

To investigate the relationship between serum C-reactive protein (CRP) levels and work impairment in patients with ankylosing spondylitis (AS) based on real-world evidence. Outpatients with confirmed AS at Chinese PLA General Hospital were recruited consecutively by Smart-phone SpondyloArthritis Management System (SpAMS) from April 2016 to April 2018. The relationship between CRP and work productivity and activity impairment questionnaire (WPAI) were evaluated. Five hundred and fifty-one outpatients with AS in paid employment were recruited. The presenteeism, overall work impairment, and activity impairment rates increased by 1.4% (1.1%, 1.8%), 1.1% (0.5%, 1.6%), and 1.7% (1.3%, 2.1%), respectively, for every 10 mg/L increase in the CRP level (all P value<0.01). However, the CRP level was not associated with absenteeism after adjusting for covariates [0.5%(-0.4%, 1.0%),P>0.05]. There is a significant association between increased serum CRP levels at baseline and the previous 7-day work impairment in patients with AS. Higher CRP levels contribute to worse presenteeism, overall work impairment, and activity impairment rates, which suggests the necessity of monitoring CRP on treatment, and also indicates that anti-inflammatory therapy may be effective for improving work productivity.

Timing of continuous renal replacement therapy in severe acute kidney injury patients with fluid overload: A retrospective cohort study

PURPOSE

We aimed to evaluate the association of early versus late initiation of Continuous renal replacement therapy (CRRT) with mortality in patients with fluid overload.

METHODS

This was a retrospective cohort study of patients with fluid overload (FO) treated with CRRT due to severe acute kidney injury (AKI) between January 2015 and December 2017 in a mixed medical intensive care unit of a teaching hospital in Beijing, China. Patients were divided into early (≤15 h) and late (>15 h) groups based on the median time from ICU admission to CRRT initiation. The primary outcome was all-cause mortality at day 60. Multivariable Cox model analysis was used for analysis.

RESULTS

The study patients were male predominant (84/150) with a mean age of 64.8 ± 16.7 years. The median FO value before CRRT initiation was 10.1% [6.2-16.1%]. The 60-day mortality rates in the early vs the late CRRT groups were 53.9% and 73%, respectively. On multivariable Cox modelling, the late initiation of CRRT was independently associated with an increased risk of death at 60 days (HR 1.75, 95% CI 1.11-2.74, p = 0.015).

CONCLUSIONS

Early initiation of CRRT was independently associated with survival benefits in severe AKI patients with fluid overload.

MRI findings of central nervous system involvement in children with haemophagocytic lymphohistiocytosis: correlation with clinical biochemical tests

AIM

To investigate the brain magnetic resonance imaging (MRI) features of children with haemophagocytic lymphohistiocytosis (HLH) with central nervous system (CNS) involvement, and to investigate the correlation with clinical biochemical tests.

MATERIAL AND METHODS

Clinical and MRI data were collected from 118 children with HLH-CNS between January 2012 and June 2019. Patients were grouped according to their MRI findings, and statistical methods were used to test for correlations between the MRI findings and biochemical variables.

RESULTS

Patients were divided into three groups, including normal appearance (Group 1, 17/118), diffuse parenchymal volume loss (Group 2, 44/118), and brain parenchyma lesions (Group 3, 57/118) containing three subtypes of brain lesions and HLH-CNS complications. Comparing biochemical values among the three groups revealed a significant difference for all values (p<0.05), except for cell counts in the cerebrospinal fluid (CSF). A pairwise comparison further showed significant inter-group differences for most of the variables. Spearman's rank correlation coefficient also demonstrated that CSF cell counts (r=0.193, p=0.036), CSF microprotein content (r=0.379, p<0.001), serum aspartate aminotransferase (AST; r=0.521, p<0.001), serum lactate dehydrogenase (LDH; r=0.514, p<0.001) and activated partial thromboplastin time (APTT; r=0.326, p<0.001) correlated positively with the MRI groups, while platelet count (PLT; r=-0.633, p<0.001) and plasma fibrinogen (FIB; r=-0.258, p=0.005) correlated negatively.

CONCLUSION

Classification of brain MRI findings of HLH-CNS correlates well with the results of several key biochemical tests. Brain MRI is a promising method to elucidate illness severity and clinical outcomes.

[Clinical characteristics of patients with ankylosing spondylitis and inflammatory bowel disease]

Objective: To analyze the clinical characteristics of patients with ankylosing spondylitis (AS) with inflammation bowel disease (IBD). Methods: AS patients fulfilling the 1984 modified New York diagnostic criteria were recruited in Chinese AS Prospective Imaging Cohort (CASPIC) consecutively from April 2016 to June 2017 in Chinese People's Liberation Army General Hospital by using smart management system for spondyloarthritis (SpAMS). The diagnosis of IBD was confirmed by tissue pathology via ileocolonoscopy. Demographic, clinical and biochemical data were collected. Results: In total, 893 patients with AS were recruited with the mean age 30.8 years. The majority were men (739, 82.8%). There were 64 (7.2%) patients concomitant with IBD. The mean age [(34.5±7.5) years vs. (30.5±8.8) years, P<0.001] was older and the disease duration [(10.8±6.9) years vs. (8.1±5.9) years, P=0.001] was longer in patients with IBD than patients without. Compared with patients without IBD, patients with IBD had more frequent involvement of the cervical spine [(21.9% (14/64) vs. 10.5% (87/829), P=0.006) and thoracic spine [29.7% (19/64) vs. 12.3% (102/829), P<0.001]. Uveitis [28.1% (18/64) vs. 16.4% (136/829), P=0.017] and psoriasis [7.8% (5/64) vs. 2.3% (19/829), P=0.009] were also more common in patients concomitant with IBD. In addition, patients with IBD had significantly higher scores in BASDAI (3.3±2.1 vs. 2.4±1.8, P<0.001), BASFI [2.2 (1.0,3.3) vs. 1.1(0.2,2.4), P<0.001)] and ASAS HI (7.1±4.3 vs. 5.3±3.7, P= 0.001) than patients without IBD. Conclusions: Compared with patients without IBD, AS patients concomitant with IBD have more severe disease activity and organ dysfunction. Furthermore, the uveitis and psoriasis are more frequently accompanied in AS patients with IBD.

Long-lasting neurobehavioral alterations in burn-injured mice resembling post-traumatic stress disorder in humans

OBJECTIVE

To establish an animal model for posttraumatic stress disorder in burn-injured patients.

METHODS

Thermal-injured mice with 15% total body surface area were subjected to a series of neurobehavioral tests at 1 and 3 months postburn. Brains were collected for analysis of key molecules expression, spleens for T cell function analysis, and blood for biochemistry and hormones detection.

RESULTS

Comparison with sham mice, burn mice showed extremely high locomotion in homecage, open field, and forced swimming tests, indicating a hyper-arousal state. Burn mice exhibited improved spatial memory in Morris Water Maze test and heightened context fear memory in context fear conditioning, suggesting re-experiencing behavior. Although burn mice showed pronounced passive avoidance in the step-through test, their active avoidance capability in response to the conditional stimulus in the shuttle box test was relatively deteriorated. Likewise, the retention of cue-feared memory was impaired in fear conditioning test. The above negative alterations in mood were recapitulated in open-field test, in which the burn mice displayed an anxiety-like behavior with less time spent in the center. However, no sign of depression was found in the forced swimming and sucrose preference tests. The negative mood of burn mice was reinforced by a deficit in sociality and preference for social novelty in social interaction test. These neurobehavioral alterations were associated with an increased expression of brain-derived neurotrophic factor along with a remarkable microgliosis and a moderate astrocytosis in the brain of burn vs. sham mice. Moreover, a prominent Th2 switch and consequent increased nuclear NF-κB translocation were seen in the splenic T cells from burn relative to sham mice.

CONCLUSIONS

We conclude that even mild burn injury could lead to long-lasting cognitive and effective alterations in mice. These findings shed light on the interactions among neuropsychology, neurobiology, and immunology throughout the recovery period of burn injury.

[The effect of arthroscopic synovectomy on refractory knee arthritis with popliteal cyst in 153 patients]

Objective: To investigate the efficacy of arthroscopic synovectomy on refractory knee arthritis complicated with popliteal cyst. Methods: Patients diagnosed as rheumatoid arthritis (RA) or spondyloarthritis (SpA) with refractory knee arthritis who underwent knee arthroscopic synovectomy in our hospital from 2010 to 2017 were enrolled, including 20 patients (16 RA, 4 SpA) with popliteal cyst. Clinical data, RA disease activity score (DAS28), SpA back pain score, etc, were collected to evaluate the efficacy of knee surgery. Results: Erythrocyte sedimentation rate (ESR) [58(17, 79)mm/1h vs. 19(9, 30)mm/1h, P< 0.001],C reactive protein (CRP) [3.72(0.92,8.14) mg/L vs. 0.85(0.10,3.08) mg/L,P<0.001], rheumatoid factor [64.6(20.2,193.3) vs. 20.5(10.0,58.4),P<0.001], DAS28 score(4.67±1.25 vs. 2.81±1.23,P<0.001), knee joint discomfort score [5(4,6) vs. 2(1,3),P<0.001] and the volume of knee joint effusion by ultrasound (P<0.05) in 95 RA patients were significantly decreased compared to those before operation. ESR [27(12,54)mm/1h vs. 20 (16,28) mm/1 h,P<0.001], CRP [3.27(1.06,6.95) mg/L vs. 1.41(0.34,3.03)mg/L,P<0.001],knee discomfort score [2(0,5) vs. 1(0,3),P<0.05], back pain visual analogue score (VAS) [5(4,5) vs. 2(1,3), P<0.001], and the volume of knee joint effusion by ultrasound (P<0.001) in 58 SpA patients were significantly lower than those before the operation.The rate [16.84%(16/95) vs. 6.32%(6/95),P=0.023] and grading (P=0.007) of popliteal cyst in RA were decreased after the operation. No statistically difference was observed in the rate [6.90% (4/58) vs. 5.17%(3/58), P=0.697] of popliteal cyst in patients with SpA, yet with a trend of decrease in 4 patients. Conclusion: This study provide evidence that knee arthroscopic synovectomy has a good effect for refractory knee arthritis, which can reduce disease activity, improve joint symptoms and decrease the grading of popliteal cyst.

Corrosion resistance and antibacterial properties of hydroxyapatite coating induced by gentamicin-loaded polymeric multilayers on magnesium alloys

As a result of their good biocompatibility, bioactivity, and mechanical properties, magnesium (Mg) alloys have received considerable attention as next generation biodegradable implants. Herein, in order to achieve a proper degradation rate and good antibacterial ability, we reported a novel hydroxyapatite coating induced by gentamicin (GS)-loaded polymeric multilayers for the surface treatment of the Mg alloy. The coating was characterized by X-ray diffraction, fourier transform infrared spectroscopy and scanning electron microscopy. The as-prepared hydroxyapatite coating showed the compact morphology and a well-crystallized apatite structure. This coating could improve the adhesion strength and reduce the corrosion rate of the substrate in simulated body fluid solution. Meanwhile, the drug release and antibacterial experiments demonstrated that the GS loaded specimen revealed a significant antimicrobial performance toward Staphylococcus aureus and had a prolonged release profile of GS, which would be helpful to the long-term bactericidal activity of the Mg implant. This coating showed acceptable biocompatibility via MTT assay and Live/dead staining. Thus, the multilayers-hydroxyapatite coated Mg alloy could improve the corrosion resistance and biocompatibility while delivering vital drugs to the site of implantation.

[Therapeutic effect of combined use of interferon alpha-1b, interleukin-2 and thalidomide on reversing minimal residual disease in acute myeloid leukemia]

目的

探讨干扰素α-1b、白细胞介素2联合沙利度胺（“干白沙”方案）对急性髓系白血病（AML）患者微小残留病（MRD）的影响。

方法

对2016年7月至2018年6月收治的18例（17例来自郑州大学附属肿瘤医院，1例来自平顶山市第一人民医院）处于血液学完全缓解但MRD阳性的AML患者应用不同剂量的“干白沙”方案，监测其MRD水平变化。

结果

18例患者接受常规剂量“干白沙”方案1~2个月，7例患者MRD转阴，3例患者MRD水平明显下降，3例MRD水平升高，5例复发。MRD水平升高的3例患者接受加量的“干白沙”方案，2例MRD转阴，1例MRD水平下降。“干白沙”方案干预治疗MRD阳性AML总有效率为72.2%。根据治疗前MRD水平分组，MRD≥1.0%的患者有效率为57.1%（4/7），MRD<1.0%的患者有效率为81.8%（9/11）。

结论

“干白沙”方案可使血液学完全缓解但MRD阳性的AML患者MRD转阴或下降，增加方案药物剂量后疗效增加，疗效与治疗前MRD水平可能呈负相关。

[Risk factors associated with delirium for patients with hip fracture under the orthogeriatric unit mode]

Objective: To explore postoperative delirium (POD)risk factors for geriatric patients who suffered hip fracture under the care of orthogeriatric unit mode. Methods: Patients aged 65 years or older, who were admitted to the orthogeriatric unit in Beijing Jishuitan Hospital from April to October 2017 for hip fracture surgery, were eligible for this prospective cohort study. After univariable analysis, significant risk factors associated with POD were further evaluated with multivariable analysis, to establish independent risk factors associated with POD. Results: A total of 203 patients with an average age of 80(65-96)years were enrolled in the study. The overall incidence of POD was 9.4%(19/203)in which hyperactive and hypoactive type accounting for 84.2%(16/19)and 15.8%(3/19), respectively. Significant difference was found between POD and non-POD groups in patients' age (P=0.003), albumin(P=0.006), TSH(P=0.018), PaCO(2) level(P=0.003), visual analogue scale (VAS )both at rest (P=0.013)and movement(P=0.010) on post-operative day 1.The further Logistic stepwise regression analysis showed that significant differences existed between groups in age(P=0.027), albumin(P=0.003), PaCO(2)(P=0.014)and VAS at rest(P=0.002). Conclusion: The independent risk factors of POD in geriatric patients undergoing hip fracture under the orthogeriatric unit mode include patients' age, pre-operative albumin as well as PaCO(2) level and post-operative VAS at rest.

Rosiglitazone Reduces Apoptosis and Inflammation in Lipopolysaccharide-Induced Human Umbilical Vein Endothelial Cells

BACKGROUND Although the peroxisome proliferator-activated receptor-g (PPARg) agonist rosiglitazone has significant anti-inflammatory properties, no scientific studies have provided new insights in its pharmacological properties with respect to acute respiratory distress syndrome (ARDS). The present investigation aimed to evaluate whether rosiglitazone can reduce apoptosis and inflammation in a lipopolysaccharide (LPS)-induced acute respiratory distress syndrome in vitro model. MATERIAL AND METHODS Human umbilical vein endothelial cells (HUVECs) were treated with 1 µg/ml LPS in the absence or presence of 10 µM rosiglitazone for 24 h. Cell viability was measured by MTT assay. Flow cytometry was used to examine the cell apoptosis and ROS production in HUVECs response to LPS and rosiglitazone. The levels of pro-inflammatory cytokine factors, including TNF-α, IL-6, CXCL12, and CXCR4, were measured by ELISA, real-time PCR, and Western blot assay, respectively. The expression of PPARg, Bcl-2, and Bax and the activity of JAK2 and STAT3 were also investigated by Western blot assay. RESULTS We found that rosiglitazone significantly inhibited LPS-induced cell apoptosis, ROS production, and inflammation in HUVECs. Furthermore, we found a significant reduction of JAK2/STAT3 activation and the Bax/Bcl-2 ratio in LPS-induced HUVECs response to rosiglitazone treatment. CONCLUSIONS Treatment with rosiglitazone can reduce apoptosis and inflammation in HUVECs induced by LPS.

[Comparison of clinical manifestations according to HLA-B(27) genotype in ankylosing spondylitis patients: real-world evidence from smart management system for spondyloarthritis]

Objective: The aim of this study was to set up a large, longitudinal and prospective database to compare the clinical manifestations in human leucocyte antigen (HLA)-B(27) positive and negative patients with ankylosing spondylitis(AS) based on real-world evidence in Chinese population. Methods: A total of 897 outpatients with confirmed AS were recruited consecutively by smart management system for spondyloarthritis (SMSP) from April 13, 2016 to June 6, 2017 in Chinese PLA General Hospital from 30 provinces and autonomous regions. 801 patients with HLA-B(27) data were included in the analysis. Demographic and clinical parameters including Bath ankylosing spondylitis disease activity index (BASDAI), Bath ankylosing spondylitis functional index (BASFI), ankylosing spondylitis disease activity score (ASDAS), arthritis, enthesitis, Bath ankylosing spondylitis metrology index (BASMI), erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) were compared between HLA-B(27) positive and negative groups. Results: A total of 801 patients were included in the analysis with an average age of (30.7±8.8) years. There were 659 males and 142 females and HLA-B(27) was present in 88.0%(705/801). Males were significantly more in HLA-B(27) positive patients [83.3%(587/705) vs. 75.0%(72/96); P=0.047].The average age at disease onset was (22.3±7.6)years in HLA-B(27) positive patients and (24.4±8.7) years in HLA-B(2)7 negative ones (P=0.028).There was significant difference in diagnose delay between two groups [14.3(2.5,43.6)months in HLA-B(27) positive patients vs. 20.3(5.0,67.4) months in HLA-B(27) negative ones, P=0.041]. Anterior uveitis was found to be significantly more common in HLA-B(27) positive patients [18.9% (133/705)vs.7.3%(7/96),P=0.005], and knee involvement less common in HLA-B(27) positive patients [4.0%(27/682) vs.10.0%(9/90), P=0.010], conversely. CRP[6.5(3.0, 16.4)mg/L vs. 3.5(1.6, 12.3)mg/L] and ESR[11.0(4.0, 24.0)mm/1h vs. 7.0(3.0, 16.0)mm/1h] were significantly higher in HLA-B(27) positive patients(P=0.005,0.013, respectively).But no differences in BASDAI,ASDAS,BASFI and BASMI were obtained between two groups. Conclusions: HLA-B(27) positive patients had a higher proportion of males, a younger age of onset and a greater risk for occurrence of anterior uveitis, suggesting a poorer prognosis.

Proinflammatory switch from Gαs to Gαi signaling by Glucagon-like peptide-1 receptor in murine splenic monocyte following burn injury

OBJECTIVE

Glucagon-like peptide-1 (GLP-1)-based therapy via G protein-coupled receptor (GPCR) GLP-1R, to attenuate hyperglycemia in critical care has attracted great attention. However, the exaggerated inflammation by GLP-1R agonist, Exendin-4, in a mouse model of burn injury was quite unexpected. Recent studies found that GPCR might elicit proinflammatory effects by switching from Gαs to Gαi signaling in the immune system. Thus, we aimed to investigate the possible Gαs to Gαi switch in GLP-1R signaling in monocyte following burn injury.

MATERIALS AND METHODS

Splenic monocytes from sham and burn mice 24 h following burn injury were treated with consecutive doses of Exendin-4 alone or in combination with an inhibitor of Gαi signaling (pertussis toxin, PTX), or a blocker of protein kinase A (H89). Cell viability was assessed by CCK-8, and the supernatant was collected for cytokine measurement by ELISA. Intracellular cAMP level, phosphorylated PKA activity, and nuclear NF-κB p65 were determined by ELISA, ERK1/2 activation was analyzed by Western blot. The expression of GLP-1R downstream molecules, Gαs, Gαi and G-protein coupled receptor kinase 2 (GRK2) were examined by immunofluorescence staining and Western blot.

RESULTS

Exendin-4 could inhibit the viability of monocyte from sham rather than burn mice. Unexpectedly, it could also reduce TNF-α secretion from sham monocyte while increase it from burn monocyte. The increased secretion of TNF-α by Exendin-4 from burn monocyte could be reversed by pretreatment of PTX or H89. Accordingly, Exendin-4 could stimulates cAMP production dose dependently from sham instead of burn monocyte. However, the blunt cAMP production from burn monocyte was further suppressed by pretreatment of PTX or H89 after 6-h incubation. Nevertheless, phosphorylated PKA activity was significantly increased by low dose of Exendin-4 in sham monocyte, by contrast, it was enhanced by high dose of Exendin-4 in burn monocyte after 1-h incubation. Following Exendin-4 treatment for 2 h ex vivo, total nuclear NF-κB and phosphorylated NF-κB activity, as well as cytoplasmic pERK1/2 expressions were reduced in sham monocyte, however, only pERK1/2 was increased by Exendin-4 in burn monocytes. Moreover, reduced expressions of GLP-1R, GRK-2 and Gαs in contrast with increased expression of Gαi were identified in burn monocyte relative to sham monocyte.

CONCLUSIONS

This study presents an unexpected proinflammatory switch from Gαs to Gαi signaling in burn monocyte, which promotes ERK1/2 and NF-κB activation and the downstream TNF-α secretion. This phenomenon is most probably responsible for proinflammatory response evoked by Gαs agonist Exendin-4 following burn injury.

[Clinical value of Short Form-36 and clinical measures in a prospective cohort study of ankylosing spondylitis patients]

OBJECTIVE

To evaluate the clinical value of Short Form-36 (SF-36) questionnaire and the most commonly used clinical measures in a prospective cohort study of ankylosing spondylitis (AS) patients.

METHODS

A total of 517 AS patients were collected from the Department of Rheumatology, Chinese PLA General Hospital from August 2013 to September 2015. The Quality of Life (QoL) was assessed by SF-36 questionnaire and compared with the general population. The correlations between QoL and clinical measures of AS, including the Bath AS disease activity index (BASDAI), Bath AS functional index (BASFI), Bath AS metrology index (BASMI) et al, were analyzed.

RESULTS

BASDAI and BASFI were significantly correlated with SF-36 scores (r>0.3, P<0.01). Logistic multiple regression analysis showed that BASDAI, BASFI, BASMI and education had close correlation with the baseline global QoL, physical and mental health. Among these clinical measures, BASDAI variation showed the most important influence on the change of global QoL, physical health and mental health (OR=0.235, 0.209, 0.125; P<0.01).

CONCLUSIONS

SF-36 can objectively reflect the QoL of patients with AS. Clinical measures such as BASDAI and BASFI show great application value in this prospective cohort study of AS patients.

In vivo DNA-protein interactions at hypersensitive site 3.5 of the human beta-globin locus control region

Using ligation-mediated polymerase chain reaction and in vivo footprinting methods to study the status of DNA-protein interactions at hypersensitive site 3.5 (HS3.5) of the locus control region in K562 and HEL cells, we found that there was protein occupancy in vivo at HS3.5 in both cell lines and the status of DNA-protein interaction was different between K562 and HEL. These data provide direct evidence that specific nuclear factor-DNA complexes form in vivo at functionally important sequence motifs of the HS3.5 in erythroid cells. This indicates that HS3.5 may play an important role in the regulation of the beta-globin gene cluster. K562 is a human erythroleukemia cell line in which the embryonic epsilon-globin gene is predominantly expressed, while the HEL cell line expresses predominantly the fetal beta-globin genes. Thus, HS3.5 might also be involved in the regulation of developmental stage-specific expression of beta-globin genes. Our results are also consistent with the model that each hypersensitive site acts as a functional unit and HS3.5 may facilitate the formation of the HS3 functional unit.

Induction of differentiation and down-regulation of c-myb gene expression in ML-1 human myeloblastic leukemia cells by the clinically effective anti-leukemia agent meisoindigo

Meisoindigo, a second generation derivative of indirubin, is an effective chemotherapeutic agent with very low toxicity used in the treatment of chronic myeloid leukemia. To determine the nature of this activity, the effect of a nontoxic concentration (0.72 micrograms/mL) of this compound on ML-1 human myeloblastic leukemic cells was examined. At such a concentration, differentiation induction was found to be the most pronounced drug effect. During the 3-day drug incubation period, the viable cell number remained essentially constant, with approximately 48% of the cells demonstrating a mature phenotype with increased acid phosphatase activity and nitroblue tetrazolium dye reduction. As observed with other DNA-specific agents, induction of ML-1 differentiation by meisoindigo was accompanied by the down-regulation of c-myb gene expression. These data suggest that induction of leukemic cell differentiation associated with decreased c-myb expression may be one of the mechanisms of the antitumor action of meisoindigo.

[Pharmacokinetics of zinc acexamate (ZAC) in rats]

Zinc acexamate (ZAC) is a new antiulcer drug. This paper reports the pharmacokinetics of ZAC in rats after single oral administration. The concentrations in biological samples were detected by spectrophotometry. This study shows that the concentration-time curve of ZAC in blood conformed to a single-compartment open model after 250, 500 and 750 ng.kg-1 ig. ZAC absorption was fast and the peak plasma level appeared in 1.5 h. The Cmax, AUC and CL/F were shown to be dose dependent. Two hours after oral administration of ZAC to normal rats, the highest level of ZAC was present in the gastrointestinal tract, while appreciable ZAC was present in the kidney, liver, plasma and lung. The level of ZAC in heart, spleen and brain was lower, no drug was detected in muscles and uterus. Six hours after oral administration, the drug concentration in various tissues decreased rapidly, but that of the gastrointestinal decreased very slowly. Feces excretion was an important route of excretion. ZAC excretion was about 11.7% of the administered dosage in feces within 48 h period, and the excreted amount from urine and bile was very small.

Determination of DNA topoisomerase II activity from L1210 cells--a target for screening antitumor agents

DNA topoisomerase II was isolated from mouse leukemia L1210 cells and the activity was determined by using P4 phage knotted DNA and pBR 322 DNA as the substrates. Based on these results, a method for screening antitumor agents by using DNA topoisomerase II as a target was established. The experiments showed that DNA topoisomerase II catalyzed pBR 322 DNA breaking and relaxing which were reversible and dependent on ATP. The activity was increased 2-4 times in the presence of ATP 1 mmol.L-1. In contrast with type II enzyme, the activity of DNA topoisomerase I was completely inhibited in the presence of ATP 1 mmol.L-1 and had full activity in the absence of ATP. Type II enzyme also showed the unknotting activity by using p4 phage knotted DNA as a substrate. DNA cleavage and relaxing reaction induced by type II enzyme increased 5-fold in the presence of Doxorubicin (Dox) 1 microgram.ml-1 or daunorubicin (Dau). Etoposide (Eto) and aclarubicin B (Acl B) also stimulated the reaction at 100 micrograms.ml-1. The cleavage reaction resulted from topoisomerase II was inhibited by other agents, such as frankincense extracts, terpenic compounds (BC series).

Establishment and biological properties of mouse granulocytic leukemic cell line-L833

A granulocytic leukemic cell line, called L833 has been established through culturing in vitro from mouse bone marrow of transplantable granulocytic leukemia. More than 280 passages have been performed in 3 years. Cell growth has been rapid and stable. Incidence of tumour formation was 100% with various routes of inoculation. The nature of granulocytic leukemia was confirmed by examination of cytology, cytochemistry, pathology and ultrastructural changes. Analysis proved chromosomes to be hypodiploid with model number of 39, loss of chromosomes, and presence of a marker. Besides the chromosomal change as mentioned above, both L883-A and L833-B derived from colonies formed from the L833 cells cultured in semi-solid agar medium, have their own marker. The cell line was sensitive to various types of antitumour agents in varying degrees. It was also sensitive to ionizing radiation. D0 values of L833 and L883-A cells were 98.8 and 104.9 rad, respectively. The results were similar to that of L801. Establishment of this cell line is of important significance for studying leukemia and screening anti-tumour agents, as well as provides a useful direct, economic and precisely quantitative tool for other relative studies.

Establishment of a model of transplantable myelocytic leukemia (L801) in LACA mice

A transplantable myelocytic leukemia model of LACA mice, designated by the name of L801, was established by intravenous injection of spleen cell suspension from mice with radiation-induced myelocytic leukemia into mice of the same strain. Until now, for more than three years, the L801 has maintained stable and rapid growth and has been reproduced for over 130 serial passages. The incidence of leukemia in inoculated animals was approximately 100% and mean survival time was 10.9 +/- 2.1 days. The L801 is of myelocytic type which has been determined by cytological, cytochemical, pathological and ultrastructural observations. Its karyotype was hypodiploid, characterized by modal number of 39, loss of Y chromosome and an abnormal huge marker chromosome. The cell cycle duration of the L801 was 16 h. C-type viral particles were observed under the electron-microscope. The L801 was sensitive, to varying extents, to various anti-tumor agents. We presume that the L801 is a useful tool in studies on mechanism of leukemogenesis, anti-tumor agent screening and treatment of experimental tumors.