Enantioselective hydrolysis of 2-carboxyethyl-3-cyano-5-methylhexanoic acid (CNDE) is the key step in chemoenzymatic synthesis of pregabalin. We purified an intracellular carboxyl esterase from Morganella morganii ZJB-09203, which exhibited high enantioselectivity and activity towards CNDE. The carboxyl esterase was purified to electrophoretic homogeneity by ammonium sulfate fraction precipitation, Phenyl Sepharose 6 FF hydrophobic interaction chromatography, anion exchange with DEAE Sephadex A-50 and Bio-Scale CHT column. The purified enzyme was a monomer with molecular mass of 68 kDa determined by SDS-PAGE and gel chromatography. Substrate specificity of the enzyme towards p-nitrophenyl esters suggested that the purified enzyme was an esterase. The optimal reaction pH for CNDE hydrolysis was 9.0, and optimal temperature was 45 degrees C. The esterase was stable between pH 7.0 and 9.0, and at 40 degrees C. The enzyme activity was enhanced by Ca2+, Cu2+ and Mn2+, whereas strongly inhibited by Co2+, Fe3+, Ni2+ and EDTA. Meanwhile, we investigated the kinetic parameters of the esterase towards p-nitrophenyl esters and effect of CNDE concentration on conversion. The present study reported the esterase capable of stereospecific hydrolysis of CNDE for the first time. Our research will provide foundations for industrial production of Pregabalin using the new biocatalyst.
Chromatography, Gel ; Electrophoresis, Polyacrylamide Gel ; Esterases ; metabolism ; Hydrogen-Ion Concentration ; Kinetics ; Molecular Weight ; Morganella morganii ; enzymology ; Substrate Specificity ; Temperature

AIM To investigate whether the relaxation characteristics of phytoestrogens resveratrol and phloretin on contractile response of aortic strips are similar to that of estrogen and the mechanisms underground. METHODS Aortic strips from rabbits were suspended in organ baths containing Krebs solution, and then isometric tension was measured. RESULTS Resveratrol and phloretin inhibited the contractile responses to norepinephrine (NE), KCl and CaCl2, shifted their concentration-response curves rightward with pD2′ values of 2.89, 3.34, 3.37 for resveratrol and 3.23, 3.52, 3.77 for phloretin respectively. Also both of them concentration-dependently relaxed KCl-precontracted aortic strip. The relaxing response of resveratrol but not of phloretin in aortic strip was significantly reduced by removal of endothelium or incubation with Nω-L-nitro-arginine and methylthioninium chloride, however both their relaxant effects were not affected by indometacin and propranolol. In Ca2+-free Krebs solution containing 0.01 mmol·L-1 EGTA, resveratrol and phloretin inhibited NE-induced contraction which was caused by Ca2+ release from intracellular store, but did not affect the contraction which was induced by Ca2+ influx. CONCLUSION Resveratrol and phloretin can induce vasorelaxations which may relate to inhibition of Ca2+ influx through potential-dependent calcium channels and Ca2+ release from intracellular stores, and the relaxing response of resveratrol is endothelium-dependent in part, but of phloretin is not endothelium-dependent.

Fourteen cases of adrenal myelolipoma proved by surgery and pathology are reported. All cases were in the right. CT of 14 cases revealed sharply marginated suprarenal mass, usually round or oval. The CT number were less than-30 HU. Their radiolucency was equal to or greater than normal fat, the remainder were of round soft mass or multiseptated streak soft trssue CT appearance may represent pathologic findings. By evaluating location, as well as the lack of contrast enhancement in the fatty portion, it seems that a specific histologic diagnosis can be made preoperatively by CT. According to CT appearance in our series, all of 14 patients established the correct diagnosis before operation. It seems that CT is superior in the preoperative diagnosis of adrenal myelolipoma to u'trasound and conventional radiologic examination including intravenous urography and angiography The etiology and pathology of myelolipoma as well as the differential diagnosis of fatty tumor in the suprarenal area are also discussed.

BACKGROUND: Gastrodin (GAS) is widely used as adjuvant therapy for vertigo, headache and hypertension. However, it is recently noticed that GAS might be used as an agent for treating obesity.OBJECTIVE: To set up obese rats of high-fat diet to observe the effects of different concentrations of GAS on body mass and serum metabolite levels and to analyze its possible mechanism.DESIGN: A randomized and controlled animal experiment.SETTING: Institute of Physiology and Psychology, School of Basic Medical Science, Lanzhou University.MATERIALS: This study was performed at the Institute of Physiology and Psychology, School of Basic Medical Science, Lanzhou University and Gansu Provincial Key Laboratory of Pre-clinical Study for New Drugs from June to August in 2007. Forty-four healthy one-week-old male SD rats, weighing (99.57±2.13)g, were purchased from Shanghai SILAIKE Laboratory Animal Co., Ltd. Disposal of animals was in accordance with the animal ethics standards. Basic animal feed was provided by Suzhou Shuangshi Laboratory Animal Feed Science and Technology Co., Ltd. High-fat forage were self-made in the authors' laboratory. Each 100 gram of high-fat forage consisted of basic feed (57.5g), egg yolk powder (11.79g), lard (10g), pig bile salt (0.2g), casein (7g), milk power (13g), salt(0.085g), and yeast powder (0.425g), and the 100 gram of high-fat forage contained of fat (22.07g), protein (23.7g), carbohydrate (39g), and quantity of heat (472.16 calorie). GAS (98% in purity) was purchased from Shaanxi Xuhuang Botanical Science & Technology Development Co., Ltd. Malondialdehyde (MDA) and total antioxidative capability (T-AOC) kits were purchased from Jiancheng Bioengineering Institute, Nanjng, Jiangsu Province.MAIN OUTCOME MEASURES: The body mass was measured every seven days. The food intake in each group was monitored in every morning. At the end of the experiment, femoral artery blood samples were collected to determine the blood glucose, the serum levels of MDA, T-AOC, Insulin, free fatty acid (FFA), glutamate-pyruvate transaminase (GPT), glutamic oxalacetic transaminase (GOT) and blood lipid profile. Insulin resistance index (IRI) and insulin sensitivity index (ISI) were calculated as IRI=(FBG×FINS)/22.5 and ISI=1/(FINS×FBG).RESULTS: All 44 rats were included in the final analysis. Body mass: The body mass in the HFFC group was significantly higher than in the NC group from 4th-8th weeks (P＜0.01), while the body mass in GAS groups was lower compared to HFFC group (P＜0.05-0.01). There were no significant differences among the GAS-H, GAS-M, and GAS-L groups (P＞0.05). Therefore, GAS had no dose-dependent relationship in inhibiting the body mass of obese rats of high-fat diet. Caloric intake: The caloric intake was significantly higher in the HFFC group than in the NC group (P＜0.01), and was significantly decreased in GAS group compared to NFFC group from the 4th week (P＜0.05-0.01). Serum levels of MDA, T-AOC, GPT and GOT: The serum level of T-AOC was decreased and that of MDA, GPT were increased significantly in the HFFC group compared with NC group (P＜0.01, P＜0.05). In the GAS-L group, T-AOC, level was significantly increased and MDA level was significantly decreased compared to HFFC group (both P＜0.01). Levels of blood glucose and insulin: In the HFFC group, blood glucose level and IRI were significantly increased, and ISI was obviously decreased compared to NC group (P＜0.05-0.01). In the GAS-L group, blood glucose level and IRI were significantly decreased, and ISI was significantly increased compared to HFFC group (P＜0.05-0.01). FFA and lipoprotein cholesterol levels: In the HFFC group, FFA and low-density lipoprotein cholesterol levels were increased and high-density lipoprotein cholesterol level was decreased compared to NC group (P＜0.05-0.01).CONCLUSION: GAS may play an important role in inhibiting rats' body mass of high-fat diet. The mechanism of action may be related to GAS regulating the metabolism of blood glucose and FFA, improving IRI and elevating T-AOC.

Objective To determine the reliability of CT perfusion scans and its parameters of ?-variate curve in evaluating the acute myocardial infarction for clinical reference of diagnosis on coronary artery disease and myocardial infarction. Methods Imatron C-150 electron beam CT (EBCT) were used to scan a hydrodynamic model which could mimic a change of contrast medium by intravenous injection in vivo. Then 6 adult canines were employed in the experiment with thoracic operation, and branches of the anterior descending and circumflex of left coronary arteries (LCA) were ligated so that myocardial infarction was made out. After intravenous administration of contrast medium, the hearts were scanned with perfusion EBCT and ?-variate curves were manifested. Some heterogeneities and differentiations between the normality and the infarctions were put forward when the parameters of all these curves were analyzed and statistically processed. Two myocardial infarctions were also verified by SPECT, and all the samples stained with TTC method were compared with those on the perfusion images. The pathological study with optical microscope and electron microscope were further carried on. Results The ascending slopes of ?-variate curves were different in the perfusion quantity. The normal curve of canine myocardium showed a somewhat quick ascending pattern first, and then a gradual descending pattern successively, with the ascending time of about 10-13 s, ascending CT value of about 34-37 HU, and peak CT value of about 70-81 HU. Whereas the curve on myocardial infarction demonstrated a prolonged ascending time of about 19.9 s, diminished ascending CT value of only about 20 HU, and peak CT value of about 53.8 HU, which were significantly different from the normality (P

The article expounds systematically the status quo of nursing management in the medical alliances from four aspects: exploring the nursing management model; standardizing, normalizing and optimizing the nursing management; completing the training system of nursing talents, and improving the training of nursing management talents; supporting orderly flow of quality nursing resources within the medical alliance. The authors pointed out the development trend of nursing management in medical alliances as informatization, the long-term training mechanism for management talent, and the last is achieving the homogenization of nursing management.

Objective:To investigate whether nursing students face the transition shock problems in the stage of clinical practice, and analyze the performance in the dimensions of physical, emotional, intellectual, sociocultural and developmental, and provide reference for formulating clinical intern training programs for nursing students.Methods:A cross-sectional survey of nursing students on the impact of transition shock and its influencing factors were conducted using the General Survey Form and the Transition Shock of Newly Graduated Nurses Scale.Results:The transition shock score of nursing students was 64.49±16.33. The score of physical dimension was 15.73±5.22, intellectual dimension was 13.13±3.80, emotional dimension was 19.15±5.32, sociocultural and developmental dimension was 16.47±5.41. The proposed academic qualifications ( F value was 5.96, P<0.01), the reason for choosing nursing profession ( F value was 7.28, P<0.01), family support level ( t value was -2.75, P=0.01), first internship department ( F value was 5.22, P<0.01), and internship intention ( F value was 3.43, P=0.03) cause the differences in the transition shock of nursing students. Conclusions:Nursing students will face the transition shock problems in the stage of clinical practice, and the impact of physical dimension is the most obvious. In the development of clinical internship training programs, hospitals and institutions should take into account the transition shock of nursing students, as earlier as possible perceive and prevent the occurrence and intensification of nursing students' clinical transformation problems, and assist them to successfully pass the transitional impact stage.

Objective:To investigate the influence of different degrees of facet joint arthropathy on the indirect decompression effect of crenel lumbar interbody fusion (CLIF), and the clinical outcomes of CLIF for the treatment of lumbar spinal stenosis with severe facet joint arthropathy (grade 3).Methods:This study reviewed a total of 269 surgical segments in 156 patients with lumbar spinal stenosis treated with CLIF technique from November 2016 to February 2020. According to preoperative CT images, the facet joint was graded according to Pathria classification. There are 19 segments with grade 0, 156 segments with grade 1, 67 segments with grade 2, and 27 segments with grade 3. Radiographic parameters included disc angle, anterior and posterior disc height, and bilateral intervertebral foramen height on CT, and the midsagittal canal diameter and axial central canal area. In 30 patients with at least one segment of grade 3, the clinical efficacy was assessed using visual analogue scale (VAS) and Oswestry disability index (ODI).Results:The average the anterior and posterior intervertebral space height, intervertebral space angle, height of bilateral intervertebral foramina, spinal canal sagittal diameter and spinal canal area were significantly improved after the operation of grade 3 facet joint degeneration segment compared to preoperation. The preoperative mean spinal canal sagittal diameter and spinal canal area of grade 3 facet joint degeneration segment were significantly less than grade 1 and grade 2. The average change of spinal canal area after grade 3 articular degeneration was significantly less than that of grade 1 and 2, but there was no significant difference with that of grade 0. The posterior decompression rate was 55.56% (15/27) for grade 3, 35.82% (24/67) for grade 2, 16.03% (25/156) for grade 1, and 21.05% (4/19) for grade 0. The posterior decompression rate of grade 3 articular process degeneration was significantly higher than that of other grades ( P<0.001). Severe lateral recess stenosis and 24.24% of severe intervertebral foraminal stenosis were found in 81.48% of grade 3 degenerative segment. The 23 patients were followed up with an average of 21.62±6.52 months, and the average improvement of ODI was 24.10%±11.09%; the average VAS for leg pain and back pain were improved significantly. Conclusion:The degrees of facet joint degeneration do not prevent intervertebral space distraction of CLIF. However, because segments with severe facet joint arthropathy were usually associated with severe spinal canal stenosis, CLIF had a high rate of second-stage posterior decompression in the treatment of lumbar spinal stenosis with severe facet joint arthropathy.

Objective To study the expression of serum interleukin(IL)-17A,calcium binding protein S100A8 and S100A9 in children with severe Mycoplasma pneumoniae pneumonia(SMPP)and their prognostic significance.Methods A total of 116 children with SMPP who were diagnosed and treated in this hospital from March 2019 to March 2021 were enrolled as the SMPP group.According to the pediatric critical cases score,the SMPP children divided into non-critical group(43 cases),critial group(40 cases),extremely critical group(33 cases).According to the prognosis of 28 d after admission,the SMPP children were divided into a good prognosis group with 82 children and a poor prognosis group with 34 children.A total of 60 physical ex-amination of healthy children in the same hospital during the same period were enrolled as the control group.The levels of serum IL-17A,S100A8,S100A9,procalcitonin(PCT),C-reactive protein(CRP),IL-6 and tumor necrosis factor(TNF)-α were detected in each group.Pearson correlation analysis was used to analyze the cor-relation between serum levels of IL-17A,S100A8,S100A9 and PCT,CRP,IL-6,and TNF-α.Multivariate Lo-gistic regression analysis was used to analyze the factors affecting the poor prognosis of children with SMPP.The receiver operating characteristic(ROC)curve was used to analyze the value of each index in predicting the poor prognosis of children with SMPP.Results The SMPP group had significantly higher serum levels of IL-17A,S100A8,S100A9,PCT,CRP,IL-6,and TNF-α than the control group(P<0.05).In children with SMPP,the serum levels of IL-17A,S100A8,and S100A9 were positively correlated with PCT,CRP,IL-6,and TNF-α(P<0.05).The serum levels of IL-17A,S100A8 and S100A9 in extremely critical group were signifi-cantly higher than those in critical group and non-critical group(P<0.05).Elevated serum levels of IL-17A,S100A8 and S100A9 were independent risk factors for poor prognosis in children with SMPP.The area under the curve(AUC)of combined detection of serum IL-17A,S100A8 and S100A9 for predicting poor prognosis in children with SMPP was 0.895,which was higher than that of single detection of serum IL-17A,S100A8 and S100A9(0.833,0.764,0.810),the differences were all statistically significant(Z=3.780,6.723,5.012,P<0.059).The sensitivity and specificity of combined detection were 0.891 and 0.755,respectively.Conclu-sion The serum levels of IL-17A,S100A8 and S100A9 are increased in children with SMPP,which are related to the severity of SMPP.The combined detection of the three indicators has a high predictive value for the poor prognosis of SMPP.

We compared the ways of deproteinization for crude polysaccharides of Coprinus comatus, and finally selected Sevage method as the optimal method. Two main fractions of Ccp-I-A and Ccp-I-B were obtained after DEAE-52 cellulose and Sephadex G-200 chromatography, both were white-floc, soluble in water, insoluble in absolute ethyl alcohol, acetone and other organic solvents. Additionally, Fehling reagent, CTAB, Sulphuric acid-carbazole, I-KI and FeCl₃ reaction were all negative. GC analysis showed Ccp-I-A was composed of mannitose, glucose and galactose in molar ratios of 2.03:9.52:1, whereas Ccp-I-B was composed of fucose and galactose with molar ratios of 1:5.21. Antioxidant activity test showed that Ccp-I-A and Ccp-I-B had good scavenging abilities on DPPH and ·OH. Compared to Ccp-I-B,the scavenging activity of Ccp-I-A was much stronger, and the scavenging rate could reach 72.1% and 55.3% respectively when the concentration was 300 μg/mL.