1.Novel Method for Determination of Lysozyme Based on Fluorescence Recovery of a Cationic Aluminum Phthalocyanine-Mucopolysaccharides Association Complex Used as a Red Emitting Fluorogenic Substrate
Lin CHEN ; Ping HUANG ; Huiqing YANG ; Yabin DENG ; Donghui LI
Chinese Journal of Analytical Chemistry 2014;(7):962-967
We developed a novel method for the rapid determination of lysozyme using a new fluorogenic substrate that consists of a cationic aluminum phthalocyanine ( tetra ( trimethylammonio ) aluminum phthalocyanine, TTMAAlPc ) , and an anionic mucopolysaccharide ( heparin, HP ) . We found that fluorescence from the cationic aluminum phthalocyanine, a red-region fluorescence probe, was quenched significantly in acidic media in the presence of low concentrations of anionic mucopolysaccharide heparin ( HP) bearing anionic sulfonic acid groups, because of induced aggregation. The practically non-fluorescent substrate degraded into small molecular fragments upon the hydrolysis of lysozyme, and thus the phthalocyanine molecules aggregated in HP were released, resulting in significant fluorescence recovery in the reaction system. This phenomenon forms the foundation of the proposed method. The reaction mechanism was determined using fluorescence spectroscopy and fluorescence anisotropy techniques. Factors that affected the determination were investigated. Under optimal conditions, the linear range was 0. 2-2 mg/L, and the detection limit was 0. 015 mg/L. The developed method is easy to operate and has good selectivity and sensitivity. This method was used in the analysis of practical samples of lysozyme, and the results were in agreement with those determined by a conventional turbidimetric method.
2.Effects of gastric bypass on plasma glucose and GLP-1 in patients with diabetes mellitus
Kerong LIN ; Lie WANG ; Zaizhong ZHANG ; Zhizhou DENG ; Yiyang LIN ; Yabin JIAO ; Yu WANG
Chinese Journal of General Surgery 2010;25(1):9-12
Objective To investigate the effect of gastric bypass on plasma glucose and glucagonlike peptide-1 (GLP-1) during oral glucose tolerance test (OGTT) in non-obese type 2 diabetes mellitus (T2DM) patients suffering from gastric ulcer necessitating a gastrectomy.Methods Thirty-two T2DM patients undergoing gastric bypass (GBP) for gastric ulcer were enrolled in this study.All patients underwent a 3-h OGTT with 75 g glucose (in a total volume of 300 ml) preoperatively and 1 week,1 month,3 months and 6 months after operation.Plasma glucose (PG) and GLP-1 concentrations were measured before (baseline) and then 30,60,120,and 180 minutes after OGTT.Areas under curves (AUC) were calculated by trapezoidal integration.The turnover of the diabetes conditions six months after the surgery were also measured.Results FPG level was (9.5±1.0) mmol/L before surgery,and significantly decreased to (7.4±1.0) mmol/L,one week,(6.5±1.2) mmol/L,one month,(8.0±1.6) mmol/L three months and (5.8±1.0) mmol/L,six months respectively after GBP(P <0.01).Peak level and AUC of PG during OGTT significantly decreased at aforementioned four time points after sugery (P < 0.01).Oral glucosestimulated peak levels of GLP-1 was (20±3) pmol/L before GBP,and markedly increased to (83±15)pmol/L,(86±20) pmol/L,(87±22) pmol/L and (92±20) pmol/L respectively after GBP(P<0.01).Stimulated AUC levels of GLP-1 significantly increased from (2457±395) pmol· min/L to (6499±1227)pmol·min/L,to (7275±1475) pmol·min/L,to (7307±1575) pmol·min/L and to (7974±1594)pmol· min/L during the study respectively(P <0.01).BMI levels were similar before and after GBP(P>0.05).Two patients experienced complications(infection of incision and intractable hiccup).T2DM control rate was 78% when assessed at a time point of six months later.Conclusion Gastric bypass is effective in terms of glucose control and improving gucose tolerance in non-obese T2DM,and the hypoglycemic effect may be contributed to more GLP-1 secretion after GBP,but not to weight loss.
3.Preparation of tissue-engineered esophageal scaffolds using electrospinning technology
Xuechan YU ; Qiuxia SHEN ; Zhenzhen LU ; Chen ZHANG ; Ling DENG ; Pin HU ; Yabin ZHU
Chinese Journal of Tissue Engineering Research 2014;(30):4771-4776
BACKGROUND:We have found that oriented fibers can guide the alignment of smooth muscle cells in our previous experiments. Thus, we designed the experiment to prepare wel aligned polymeric fibers using electrospinning technology, aiming at guiding the growth of esophageal smooth muscle cells to maintain cellmorphology and biological function. OBJECTIVE:Using electrospinning technology, to fabricate isotropic and directed nano-fibrous scaffolds made of polycaprolacton, gelatin and silk fibroin. METHODS:Polycaprolacton/silk fibroin fibers at a ratio of 4:1 were prepared with proper parameters, including solution concentration, voltage and injection speed, under the self-made spinning system. The polycaprolacton/gelatin sheets with mass ratio of 2:1, 1:1 and 1:2, respectively, were also fabricated under suitable process parameters. Using the rol er col ector instead of the metal plate, polycaprolacton/gelatin nano-fibrous scaffold with good alignment of fibers was manufactured. RESULTS AND CONCLUSION:The isotropic polycaprolacton/silk fibroin scaffold with fiber diameter of (535.9±126.7) nm was prepared under conditions of solution concentration (0.08 g/mL), injection speed (1.6 mL/h) and voltage (22.5 kV), and these fibers were uniform with no beads. The isotropic polycaprolacton/gelatin scaffold with fiber diameter of (257.9±117.8) nm was prepared under conditions of solution concentration (0.10 g/mL), injection speed (0.8 mL/h) and voltage (22.5 kV). Using the rol er col ector instead of the previous metal plate, polycaprolacton/gelatin (w:w, 1:2) nano-fibrous scaffold with good alignment of fibers was manufactured. The process parameters were 3 000 r/min of rol ing speed, 0.8 mL/h of injection speed and 15 kV of voltage.
4.Congenital tracheobiliary fistula treated with biological glue plugging under bronchoscopic guidance:a case report and literature review
Xia CHEN ; Yuqun YAN ; Wenhua DENG ; Jiahong REN ; Junhua SHU ; Yabin WU
Chinese Journal of Applied Clinical Pediatrics 2018;33(11):839-841
Objective To investigate the clinical characteristics,diagnosis and treatment of congenital tracheobiliary fistula (CTBF) in children.Methods A case of CTBF admitted into the Department of Pediatric Respiration,Hubei Maternal and Child Health Care Hospital in 2016 was reported,and the related literatures were reviewed.The clinical features,diagnostic methods,treatment status and clinical outcomes of the disease were analyzed.Results The patient was 3 years and 7 months old.The main clinical manifestations were recurrent cough,pneumonia and atelectasis.CTBF was diagnosed by means of iodine oil radiography and treated with biological glue plugging under bronchoscopic guidance.So far,only 30 cases of CTBF have been reported in the English literatures,but only 2 cases in the Chinese literatures.The main clinical manifestations were cough,dyspnea,sputum or bile vomiting,aspiration pneumonia,atelectasis or emphysema.Diagnostic methods for CTBF included bronchoscopy,bronchial angiography and cholangiography,hepatobiliary scan,CT scan and magnetic resonance imaging.Except for this case treated with biological glue plugging under bronchoscopic guidance,all other patients were treated with surgery.The operation methods included fistula ligation,gastrostomy,liver resection,fistula jejunum Roux-en-Y anastomosis,hepatic hilum jejunum anastomosis,gallbladder jejunum anastomosis,etc.Only 4 cases died,and the rest of the patients recovered.Conclusions CTBF should be suspected in children with persistent chronic cough.Iodine oil radiography through bronchoscopy is a simple and feasible method for diagnosis of CTBF.Besides surgery,the lavage and the biological glue plugging method through bronchoscopy is also an effective way to treat CTBF in children without severe biliary malformation.
5.Skin Rash as the First Manifestation of Pediatric Chronic Neutrophilic Leukemia
Yabin ZHOU ; Ruoyu DUAN ; Jiafeng YAO ; Maoquan QIN ; Jianghong DENG ; Zigang XU ; Runhui WU
JOURNAL OF RARE DISEASES 2022;1(4):413-419
A 6-year-old girl presented with recurrent skin rash at the initial stage, recent joint pain, and neutrophilia was found during a routine blood test. After a multidisciplinary case discussion, she was diagnosed with chronic neutrophil leukemia, and the symptoms were relieved after hydroxyurea and luxolitinib treatment. She received the allogeneic hematopoietic stem cell transplantation subsequently. At present, she is in stable condition and under follow-up. Chronic neutrophil leukemia is a rare disease, which rarely occurs in children. It is more difficult to diagnose in patients with skin rash as the first manifestation. The diagnosis and treatment of this case reflects the important role of multidisciplinary cooperation in the diagnosis and treatment of difficult and rare diseases.