1.Determination of thiodiglycolic acid in urine with gas chromatography-mass spectrometer.
Qingfeng XIAO ; Zhihua FU ; Chengming MENG ; Yuelan XUAN ; Wenhua QIN
Chinese Journal of Industrial Hygiene and Occupational Diseases 2015;33(6):474-476
OBJECTIVETo establish a rapid determination method with gas chromatography-mass spectrometer (GC-MS) for thiodiglycolic acid (TDGA), a vinyl chloride (VCM) biomarker.
METHODSA high- sensitivity determination method was established using a moderate methyl esterification instead of methyl esterification of highly toxic diazo reaction.
RESULTSThe standard curve regression linear equation of the method was: y=8460.5x-4758.2, the linear coefficient was 0.999 7, the minimum quantity concentration was 2.0 µg/L, the range of precision value was 0.81%-2.38%, and the average recovery of standard addition was 99.0%-102.9%.
CONCLUSIONThis method reduces the risk of traditional methyl esterification, improves the determination sensitivity compared with the GC-FPD method, and meets the determination requirement of TDGA.
Gas Chromatography-Mass Spectrometry ; Humans ; Thioglycolates ; urine ; Vinyl Chloride
2.THE PARANODAL REGION AND AXO-GLIAL JUNCTION OF MYELINATED FIBERS
Chongjie GUO ; Qingfeng MENG ; Hua ZHANG ; Xiulan HAN ; Shaojie LIU ;
Acta Anatomica Sinica 1989;0(S1):-
By using electron microscopy, the paranodal region and axo-glial junction were examined in optic nerves of rats aged 14 days. The paranodal region was characterized in longitudinal sections by the sequential termination of the myelin lamellae, beginning proximally with the innermost and ending, at the Ranvier node, with the outermost lamella. The termination of each lamella was accom- panied by a separation of the major dense line of the compact myelin and the consequent formation of a "loop" of glial cytoplasm. Each paranodal loop inde- nted the axonal surface as it became junctionally apposed to the axolemma. The periaxonal extracellular space, 10-20nm in width in the internodal region and reduced at the paranodal junction to approximately 3nm, forming an axo-glial junction, which was thought to be held together by dense structure. The parano- dal junction seems to serve strong adhesion between the apposed axonal and glial membranes. Conduction of the nerve impulses in myelinated axons was saltatory. Axons and sheath cells probably maintain vital communication with one another, presumably at the paranodal junctional complex. This communication was viewed as vital to the stability and maintenance of myelin. We found some clear vesi- cles in axoplasm near the Ranvier node and speculated that there were endocyto- sis and exocytosis in paranodal region. This was a direct morphological evidence supporting metabolic coupling between axons and sheeth cells.
3.Clinical features and gene mutations in a Chinese family with choroideremia
Qingfeng MENG ; Qing SUN ; Mingming YANG ; Yan TENG
Chinese Journal of Ocular Fundus Diseases 2017;33(1):48-51
Objective To observe the clinical features, phenotypes and genotypes in a Chinese family with choroideremia (CHM). Methods A Chinese four-generation family (15 members) with CHM, including 5 patients (4 males/1 female), 2 female carriers and 8 healthy members, was enrolled in this study. Initially all family members underwent best corrected visual acuity (BCVA), indirect ophthalmoscopy, fundus fluorescein angiography, optical coherence tomography (OCT), visual field and full view electroretinogram (ERG). BCVA was followed up for 3 years. Venous blood samples were collected, and all of the 15 coding exons and flanking intron regions were amplified in the proband by polymerase chain reaction followed by direct sequencing. Protein structure was modeled based on the protein data bank and mutations in DeepView v4.0.1 to predict the effect of the mutations. A total of 180 healthy volunteers were enrolled as control group to matching CHM gene sequences. Results The visual acuity (VA) of 3/4 adult male patients began to decrease at less than 10, 10 and 30 years old, the average BCVA was 0.43. There were characteristic signs and symptoms of CHM including narrow visual field, extinguished rod and cone response in ERG, disappeared junction line and intermediate line of photoreceptor inner segment/outer segment on OCT. After 3 years, the mean BCVA decreased to 0.11. The BCVA of one young male patient was 1.0 in both eyes with minor changes fundus and visual field. The VA of the female patient began to decrease at 50 years old, her BCVA of two eyes were 0.5 and 0.25, respectively. The fundus changes were typical of CHM, with relative scotomas in the peripheral visual field of OD, and big scotomas in the OS. After 3 years, her mean BCVA decreased to 0.2. Of 2 female carriers, one had minor fundus changes (patches of pigmentary deposits, atrophy spots of retinal pigment epithelium cells), and the other was normal. A novel heterozygous c.1837G>A mutation in exon 15 of CHM was detected in the proband, which resulted in the substitution of serine by proline at codon 613 (p.D613N). Based on molecular modeling, the misfolded protein caused by the mutation might destabilize the structure of the helix that potentially could affect the global stability of the Rep-1 protein. Conclusions A novel c.1837G>A (p.D613N) mutation may be the causative mutation for CHM in this family. Female CHM carriers may have some signs and symptoms.
4.Effects of Acetyl-l-carnitine on Autophagy, Apoptosis, and Locomotor Function after Acute Spinal Cord Injury in Rats
Qingfeng MENG ; Mingchao ZHANG ; Wei LU ; Yunlong BI ; Zhongkai FAN
Chinese Journal of Rehabilitation Theory and Practice 2016;22(7):754-758
Objective To observe the effects of acetyl-l-carnitine (ALC) on autophagy, apoptosis and motor function after acute spinal cord injury (ASCI) in rats. Methods Thirty-six adult female Sprague-Dawley rats were randomly divided into sham operation group (Sham group, n=12), simple spinal cord injury group (SCI group, n=12), ALC treatment group (ALC group, n=12). Spinal cord injury model at the level of T10 segment was established using Allen's method. They were assessed with Basso-Beattle-Bresnahan (BBB) scale three days after injury. Then the rats were sacrificed, and the expression of microtubule associated protein 1 light chain 3 (LC3)-II in spinal cord was detect-ed with Western blotting and immunofluorescent labeling, and the number of apoptotic cells were assessed with TUNEL staining. Results The expression of LC3-II and the number of apoptotic cells increased in SCI group compared with those in Sham group (P<0.01), while the BBB score decreased (P<0.001). The expression of LC3-II increased and the number of apoptotic cells decreased in ALC group compared with those in SCI group (P<0.001), while the BBB score increased (P<0.01). Conclusion ALC may promote autophagy, and inhibit apopto-sis to improve the locomotor function after ASCI.
5.Effects of dipfluzine on experimental arrhythmias and cytosolic calcium concentration
Qingfeng MIAO ; Suwen SU ; Wei ZHANG ; Mingfang GUO ; Linfang LI ; Jing MENG ; Yongjian ZHANG
Chinese Journal of Pharmacology and Toxicology 2006;20(6):448-454
AIM To investigate whether dipfluzine (Dip) possesses antiarrhythmic effect on experimental arrhythmias and effect on cytosolic calcium in ventricular myocytes of guinea-pig. METHODS Experimental arrhythmias were induced by strophanthin G infusion through jugular vein in guinea-pigs and by myocardial ischemia-reperfusion (I-R) in rats respectively. Cytosolic calcium concentration ([Ca2+]i) of isolated guinea-pig ventricular myocytes was examined with laser confocal scanning microscope. RESULTSIn guinea-pigs pretreatment with Dip 20 mg·kg-1 increased the dosages of strophanthin G required to induce ventricular premature contraction (VP), ventricular tachycardia (VT), ventricular fibrillation (VF) and cardiac arrest (CA), pretreatment with Dip 10 mg·kg-1 increased the dosages of strophanthin G required to induce VP. In the I-R-induced arrhythmic model of rats, Dip 20 mg·kg-1 decreased the number of rats exhibiting VT, VF and CA, and the number of rats exhibiting VF and CA was decreased by Dip 10 mg·kg-1. Both Dip and verapamil (Ver) decreased [Ca2+]i of the ventricular myocytes in normal Tyrode′s solution. The Ca2+ overload evoked by high extracellular Ca2+ levels was inhibited by Dip and Ver, and the prophylactic effect of Dip was less than that of Ver, while the curative effect of Dip was more obvious than that of Ver. CONCLUSION Dip has antiarrhythmic effect, which is likely related to the modulation on the intracellular calcium homeostasis.
6.Balloon angloplasty and stenting of hepatic veins for the treatment of Budd-Chiari syndrome caused by long segmental occlusion of the inferior vena cava (IVC)
Xiaoqiang LI ; Qingfeng RUI ; Qingyou MENG ; Hongfei SANG ; Aimin QIAN ; Liwei ZHU ; Ping LIU
Chinese Journal of General Surgery 2012;27(7):551-553
Objective To evaluate balloon angioplasty and stenting of the hepatic veins for the treatment of Budd-Chiari syndrome with long segmental inferior vena cava (IVC).Methods The hepatic veins were evaluated by colour Doppler,CT or MR.Epidiaphragmatic inferior vena cavography was performed to locate the stenused opening of the hepatic veins,in case of membrane occlusion of the hepatic veins,a puncture was attempted with Rups100 needle and then balloon dilation of the hepatic veins and stents implantation was carried out.Results In 40 cases of long segmental inferior vena cava ( IVC ) occlusive Budd-Chiari syndrome,membranous obstruction of the hepatic veins was found in 5 cases and short-segmental occlusion in 24 cases.28 cases were successfully treated with balloon dilation and stents implantation,including percutaneous transluminal angioplasty(PTA) of hepatic vein in 5 cases,and stent implantation in 23 cases,puncture procedure was failed in 1 case.Postoperative follow-up was made in 26 cases from 6 to 62 months ( mean,24.0 ± 1.3 months ).Symptoms recurred in 6 cases.Hepatic vein restenosis or occlusion were observed using color Doppler ultrasound in 6 cases.Conclusions Most lesions in hepatic veins were membranous obstruction or short-segmental occlusion among patients with long-segmental occlusion of IVC.Balloon angioplasty and stenting of hepatic veins for long segmental IVC occlusive Budd-Chiari syndrome through jugular vein can relieve hepatic venous obstruction and relieve portal hypertension.
7.The Changes of Hormones in the Model of Splennic Asthenia Complicating Gastric Ulcer
Bairong LU ; Jie LIAN ; Haiyan ZHANG ; Juan DU ; Xiuqin WANG ; Qingfeng MENG
Journal of Medical Research 2006;0(09):-
Objective To probe the changes of hormones in the model of splennic asthenia complicating gastric ulcer, and reveal the relation between thyroid gland and splennic asthenia gastric ulcer. Methods Building model of splennic asthenia complicating gastric ulcer in rats, treatment them in plus sijunzi decoction ,selecting rats with typical gastric ulcer four days after and rats with the ulcer healing basically fourteen days after building models, then the rats were divided into four groups, the model group, the treatment group, spontaneous recovery group and the control group. With immunohistochemical stain , the OD values of enzymes were analyzed with image analysis, and were analyzed statistically. Results Compare with control gronp ,4 model and 14 modelIn rats the thyrocalcitonin secretion of thyroid parafollicular decreased, Compared with 14 day control indexes in the treatment group recovered, but in the spontaneous recovery group all indexes didn’t change obviously. Conclusions In the model of splennic asthenia complicating gastric ulcer, some injury can occur on thyroid gland ,and this also promote gastric ulcer development. plus sijunzi decoction has some treating action.
8.Assembly and components of the type III secretion system of Salmonel l a
Long CHEN ; Qingfeng MENG ; Yuanhuan KANG ; Xiaofeng SHAN ; Liang CAO ; Aidong QIAN
Chinese Journal of Zoonoses 2014;(7):753-756
Salmonella is the main food-borne pathogen that causes food poisoning and gastroenteritis in human and ani-mals .The type III secretion system in Salmonella has played an important role in the invasion of host cell .In recent years ,the research of the composition ,assembly and related pathogenesis of Salmonella T3SS have made some progress .This article re-views the composition and assembly of Salmonella type III secretion system ,which could provide further study the pathogene-sis of Salmonella and also the new strategies and methods toward the treatment and prevention of Salmonella infections .
9.Effect of local mild hypothermia on regional cerebral blood flow in patients with cerebral infarction assessed by 99mTc-ECD SPECT imaging
Zhangwei LUO ; Tianzi LI ; Xuebin LI ; Junfang HUANG ; Lanqing MENG ; Qingfeng LI ; Ye LIANG ; Jindu LI
The Journal of Practical Medicine 2016;32(18):2948-2951
Objective To investigate the frequency of lesions detection in patients with cerebral infarction (CI) with SPECT/CT. To investigate fluctuation of regional cerebral blood flow (rCBF) and its relationship with clinical symptoms. Methods Sixty-seven CI patients without cerebellar lesion were randomly selected. The rCBF in the regions of interest (ROI) was examined by SPECT/CT, which was collected from the frontal lobe, temporal lobe, parietal lobe, occipital lobe, thalamus, basal ganglia and cerebellum. The rCBF index was calculated. The association between fluctuation of rCBF index and clinical symptoms of patients was explored. Results There were 251 positive regions in all viewing regions , the total positive rate was 31.2%. The left side was 38.1%, while the right side was 24.4% (χ2=17.522,P < 0.01). In normal group, there were no statistical difference of average rCBF between two halves (P > 0.05). However, the average rCBF on the left parietal lobe was lower (P < 0.01). The average rCBF in the abnormal group was lower than that in ipsilateral normal group (P < 0.01). The average rCBF index in the abnormal group was higher (P < 0.01). In normal group , the average rCBF on the frontal lobe and parietal lobe was low , but the average rCBF on the thalamus and basal ganglia was high (P < 0.01). In abnormal group, there were no statistical difference in the average rCBF (P >0.05). rCBF≥0.7 is a clinical sign of abnormal ROI. Conclusion 30% of ROI of CI patients have lesions and the positive rate of the left side was higher. The biological rCBF values of all lobes were different. Therefore, rCBF index could be used to reflect whether the ROI is normal. rCBF≥0.7 could be used as a sign to quantitatively assess abnormal ROI in clinical practice.
10.Effects of alpha lipoic acid on diabetic retinopathy and serum levels of serum asymmetric dimethylarginine and oxidative stress
Qingfeng YIN ; Haijun MA ; Xuehui CHEN ; Meng CAO ; Liwei BAI ; Qinggui ZHANG
Journal of Chinese Physician 2014;16(10):1328-1332
Objective To investigate the effects of alpha lipoic acid on patients with diabetic retinopathy (DR),explore the possible mechanisms,and provide experimental evidence for the treatment of DR with lipoic acid.Methods Totally 75 DR patients were randomly divided into control group and treatment group.Patients in control group received the standard hypoglycemic treatment,antihypertensive therapy,and other comprehensive treatment.Patients from the treatment group were treated with alpha lipoic acid 600 mg + 250 ml 0.9% sodium chloride injection additionally,avoiding light intravenous therapy,for a total of 4 weeks.Before and after treatment,fundus fluorescein angiography and visual inspection were detected in two groups.In addition,serum level of asymmetric dimethylarginine (ADMA) were detected with high performance liquid chromatography,serum lipid peroxidation product malondialdehyde (MDA) content and superoxide dismutase (SOD) activity were detected to reflect the in vivo oxidative stress before and after treatment in two groups.Results Compared to the control group,visual acuity was improved significantly (P < 0.05),and total efficiency of ocular lesions-improved was increased significantly (84.21% vs 40.54%,x2 =15.28,P < 0.01).Serum levels of endogenous inhibitor of nitric oxide synthase ADMA [(0.32 ±0.13) μmol/L vs (0.51 ± 0.26) μmol/L,P < 0.05] and MDA [(3.22 ± 0.90) nmol/L vs (5.13 ± 0.42) nmol/ml,P < 0.05] were significantly decreased,while SOD levels [(72.68 ± 1.31) U/ml vs (53.16 ± 1.54) U/ml,P <0.05] were significantly increased in DR patients after alpha lipoic acid treatment.Conclusions Alpha lipoic acid had some therapeutic effects for DR patients,which mainly lied in the improvement of visual acuity and eye disease,might be related to the decrease of oxidative stress and serum level of endogenous nitric oxide synthase (NOS) inhibitor ADMA.