Effect of ulinastatin on postoperative cognitive dysfunction in preoperative sleep deprived aged rats / 中华麻醉学杂志

Objective To evaluate the effect of ulinastatin on postoperative cognitive dysfunction in preoperative sleep deprived aged rats.Methods Sixty clean healthy male Sprague-Dawley rats,aged 18 months,weighing 350-500 g,were divided into 3 groups (n=20 each) using a random number table:control group (group C),sleep deprivation group (group D) and ulinastatin group (group U).Sleep deprivation was induced by using modified multiple platform method in D and U groups,and then splenectomy was performed in three groups.Ulinastatin 100 U/g was intraperitoneally injected before sleep deprivation and immediately after operation in group U.Ten rats were randomly selected at 3 days after operation and sacrificed,and hippocampi were removed for determination of the contents of interleukin-1β (IL-1β),IL-6 and tumor necrosis factor-α (TNF-α) by enzyme-linked immunosorbent assay.Morris water maze test was performed at 3-7 days after operation in the rest ten rats in each group,and the escape latency and time of staying at the original platform were recorded.Results Compared with group C,the escape latency was significantly prolonged at 4-6 days after operation,the time of staying at the original platform was shortened,and the contents of IL-1β,IL-6 and TNF-α were increased at 3 days after operation in D and U groups (P＜0.05).Compared with group D,the escape latency was significantly shortened at 4-6 days after operation,the time spent in the original platform was prolonged,and the contents of IL-1β,IL-6 and TNF-α were decreased at 3 days after operation in group U (P＜0.05).Conclusion Ulinastatin can mitigate postoperative cognitive dysfunction in preoperative sleep deprived aged rats,which is related to inhibiting inflammatory responses.

Effects of Dexmedetomidine Hydrochloride Injection on Elderly Patients Underwent Thoracic Surgery dur-ing Anesthesia Recovery Period / 中国药房

OBJECTIVE:To investigate the effects of Dexmedetomidine hydrochloride injection on elderly patients underwent thoracic surgery during anesthesia recovery period. METHODS:Totally 60 elderly patients underwent thoracic surgery in our hospi-tal during Jun. 2014-Feb. 2016 were selected as research objects and then divided into control group and observation group ac-cording to even and odd-numbered admission order,with 30 cases in each group. Control group was given Propofol injection 0.5-1 mg/kg intravenously 5 min after mask oxygen inhalation. Observation group was given Dexmedetomidine hydrochloride injec-tion 0.5-1.0 μg/kg intravenously. Both group were successively given Etomidate emulsion injection 0.1-0.2 mg/kg,Sufentanil citrate injection 0.3 μg/kg and Cisatracurium besilate for injection 0.2 mg/kg intravenously for anesthesia induction;tracheal intubation was performed and ventilator was used to assist ventilation after anesthesia induction. And then control group was given continuous intravenous dripping of propofol 3-6 mg/kg·h;observation group was given continuous intravenous dripping of Dexmedetomidine hydrochloride injection 0.2-0.5 μg/(kg·h). At the same time,both group were given continuous intravenous dripping of sufentanil 0.1-0.2 μg/(kg·min)and cis-atracurium 1.5-2 μg/(kg·min),and continuously inhaled 1%-2% sevoflurane for anesthesia mainte-nance. Hemodynamic index(HR,MAP,SpO2),postoperative recovery,the occurrence of delirium,restlessness,cough and involun-tary movement were observed in 2 groups before surgery (T0),after anesthesia induction (T1),at the moment of sputum suction and extubation(T2),5 min after extubation(T3),30 min after extubation(T4). RESULTS:At T2 and T3,HR and MAP of control group were increased significantly compared to at T0,T1,and higher than those of observation group,with statistical significance (P0.05). At T0,T1,T2,T3, T4,there was no statistical significance in SpO2 level between 2 groups(P>0.05). The breathing recovery time,eye openning time and extubation time of observation group were significantly shorter than those of control group,with statistical significance (P<0.05). The incidence of postoperative restlessness,delirium,cough and involuntary movement in observation group were signifi-cantly lower than control group,with statistical significance (P<0.05). CONCLUSIONS:Dexmedetomidine hydrochloride injec-tion can keep hemodynamics stable in elderly patients underwent thoracic surgery during anesthesia recovery period.,shorten recov-ery time and reduce the occurrence of stress response as postoperative delirium,restlessness,cough,involuntary movement.

Long-term results of selective dorsal rhizotomy for hereditary spastic paraparesis.

Pure hereditary spastic paraparesis usually presents with progressive weakness and spasticity of the legs, which is similar to spastic cerebral palsy. In this study selective dorsal rhizotomy (SDR) was performed to improve the spasticity of pure hereditary spastic paraparesis and the long-term results were followed. A series of four patients with pure hereditary spastic paraparesis diagnosed by a multidisciplinary team received SDR. The dorsal rootlets from the L2 to S1 levels were selectively resected under electrophysiological monitoring. The patients were followed up for more than 2 years to evaluate the outcome of surgery. There was a significant reduction in muscular spasm after SDR. Standing and walking stability were improved in all patients which led to improvement in walking posture and longer walking distance without assistance. No urinary retention, cerebrospinal fluid leak, surgical infection or kyphosis occurred. For severe pure hereditary spastic paraparesis, SDR can reduce muscle spasm and improve standing and walking stability. These results were stable throughout follow-up. SDR performed at the level of the conus medullaris through a laminectomy from T12 to L1 or L1 to L2 requires a shorter incision, laminectomy of fewer segments, and has a shorter operation time than the usual method (laminectomy from L2 to S1). Intraoperative electrophysiological monitoring is helpful to discriminate abnormal rootlets and protect sphincter function.

A survey on published papers by nursing staff / 现代临床护理

Objective To investigate publication of papers by nursing staff in a TCM hospital and to find out the problems as well as countermeasures.Method A retrospective analysis about authors,education,academictitle,length of service and age was done to investigate the classes of published papers from 2008 to 2012.Results The academic publication by the nurses from 2008 to 2012 was increased.Among these articles,the TCM nursing techniques took up the largest ratio,which accounted for 29.12%. There were significant differences in ages,length of service and educational background in authors(P<0.05).Conclusions Nurses’ awareness and capabilities of publishing academic papers needs enhancement as well as training.It may be significant to strengthen their incentives in scientific research by enforcing encouraging policies.

A systematic review and meta-analysis of randomized controlled trails : adjuvant interferon therapy for hepatocellular carcinoma / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To evaluate the efficacy and safety of adjuvant interferon (IFN) therapy for viral hepatitis related hepatocellular carcinoma(HCC) after the treatment of resection, ablation or TACE.</p><p><b>METHODS</b>PUBMED, EMBASE, Cochrane Library, CNKI, CBM, Wan fang Data were searched, plus some manual search and searching on the internet for grey literature. The studies that according to the standards were included, then Meta-analysis were done.</p><p><b>RESULTS</b>Eight studies (n=857, 442 treated with IFN) were eligible for this study, pooled data showed benefit of IFN for the prevention of HCC recurrence, 1-year [RR=0.71, 95% CI (0.51, 0.99)], 3-year [RR=0.86, 95% CI (0.76-0.98)], 4-year [RR=0.79, 95% CI (0.68-0.91)]. IFN showed benefit for improving 1-year and 2-year survival, 1-year [RR=1.09, 95% CI (1.01-1.18)], 2-year [RR=1.25, 95% CI (1.04-1.50)]. The difference on 2-year, 5-year recurrence rate are without statistical significance, the same to 3-year, 4-year, 5-year survival rate.</p><p><b>CONCLUSION</b>IFN therapy after the treatment of resection, ablation or TACE can probably reduce HCC recurrence rate and improve survival with acceptable toxicities.</p>

Neuronal firing in the ventrolateral thalamus of patients with Parkinson's disease differs from that with essential tremor / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Although thalamotomy could dramatically improve both parkinsonian resting tremor and essential tremor (ET), the mechanisms are obviously different. This study aimed to investigate the neuronal activities in the ventrolateral thalamus of Parkinson's disease (PD) and ET.</p><p><b>METHODS</b>Thirty-six patients (PD: 20, ET: 16) were studied. Microelectrode recordings in the ventral oral posterior (Vop) and the ventral intermediate nucleus (Vim) of thalamus was performed on these patients who underwent thalamotomy. Electromyography (EMG) was recorded simultaneously on the contralateral limbs to surgery. Single unit analysis and the interspike intervals (ISIs) were measured for each neuronal type. ISI histogram and auto-correlograms were constructed to estimate the pattern of neuronal firing. Mann-Whitney test and Kruskal-Wallis (K-W) test were used to compare the mean spontaneous firing rate (MSFR) of neurons of PD and ET patients.</p><p><b>RESULTS</b>Three hundred and twenty-three neurons were obtained from 20 PD trajectories, including 151 (46.7%) tremor related neuronal activity, 74 neurons (22.9%) with tonic firing, and 98 (30.4%) neurons with irregular discharge. One hundred and eighty-seven neurons were identified from 16 ET trajectories including 46 (24.6%) tremor-related neuronal activity, 77 (41.2%) neurons with tonic firing, and 64 neurons (34.2%) with irregular discharge. The analysis of MSFR of neurons with tonic firing was 26.7 (3.4 - 68.3) Hz (n = 74) and that of neurons with irregular discharge (n = 98) was 13.9 (3.0 - 58.1) Hz in PD; whereas MSFR of neurons with tonic firing (n = 77) was 48.8 (19.0 - 135.5) Hz and that of neurons with irregular discharge (n = 64) was 26.3 (8.7 - 84.7) Hz in ET. There were significant differences in the MSFR of two types of neuron for PD and ET (K-W test, both P < 0.05). Significant differences in the MSFR of neuron were also obtained from Vop and Vim of PD and ET (16.3 Hz vs. 34.8 Hz, 28.0 Hz vs. 49.9 Hz) (K-W test, both P < 0.05), respectively.</p><p><b>CONCLUSION</b>In consistent with recent findings, the decreased MSFR of neurons observed in the Vop is likely to be involved in PD whereas the increased MSFR of neurons seen in the Vim may be a cause of ET.</p>

Efficacy evaluation of intersphincteric resection during anus-preserving operation for ultralow rectal carcinoma / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To evaluate anorectal dynamics, function and efficacy of ultralow rectal carcinoma patients undergone intersphincteric resection(ISR).</p><p><b>METHODS</b>From January 2004 to August 2007, 30 patients with ultralow rectal carcinoma(2.5-4.0 cm distance from anal edge) underwent ISR. All the patients received anorectal manometry before and after operation. The postoperative anal function was evaluated by Williams continence standard and the treatment outcome was followed up.</p><p><b>RESULTS</b>After ISR operation, anal resting pressure, maximum squeeze pressure and maximum tolerance volume of the rectum decreased significantly (all P<0.01) and restored gradually, but not to normal. The rectal anal inhibitory reflex disappeared in 27 patients(90.0%) and was not improved. According to Williams continence standard, 86.7%, 93.3% and 96.7% of patients obtained acceptable anal function in 3, 6, and 12 months after operation respectively. During follow-up of 12 to 44 months, all the patients were still alive and no patient developed pelvis or local recurrence, distant metastasis and anastomotic leakage. Fecal eczema of anus occurred in 10 patients, colonic mucosa prolapse in 2 patients and stenosis of anal canal in one patient.</p><p><b>CONCLUSION</b>ISR for ultralow rectal carcinoma can not only attain radical treatment outcome, but also preserve anal sphincter.</p>

Subthalamic deep brain stimulation for Parkinson's disease: correlation of active contacts and electrophysiologically mapped subthalamic nucleus / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Subthalamic deep brain stimulation (STN-DBS) has been shown to be effective in the treatment of Parkinson's disease. The site for permanent stimulation is still in debate. This study aimed to assess the position of active contacts in relation to the subthalamic nucleus.</p><p><b>METHODS</b>We reviewed the location of 40 electrodes in 34 patients who underwent STN-DBS. The position of electrode was evaluated by postoperative magnetic resonance imaging (MRI). The position of active contacts was compared with the subthalamic nucleus (STN) determined by intraoperative electrophysiological mapping and postoperative MRI.</p><p><b>RESULTS</b>The average position of the 40 active contacts was (11.7 + or - 1.2) mm lateral, (0.6 + or - 1.3) mm anterior, and (0.7 + or - 1.4) mm vertical to the midcommissural point. The dorsal margin of the STN was (11.6 + or - 1.1) mm lateral, (0.2 + or - 1.1) mm anterior, and (1.3 + or - 1.1) mm vertical to the midcommissural point. When compared with the dorsal margin of the STN, the active contacts were located more dorsally (P = 0.033) and anteriorly (P = 0.012), no significant difference was found in the lateral direction (P = 0.107). When compared with the position of the STN, 26 (65%) of active contacts were located in the region dorsal to the STN, only 13 (32.5%) were located in the upper two-thirds portion of STN.</p><p><b>CONCLUSIONS</b>The site for permanent stimulation appears to be in the subthalamic region dorsal to the STN, close to the dorsal margin of the STN. Besides the dorsal portion of the STN, other structures such as fields of Forel H and zona incerta may also be involved in the therapeutic benefit of deep brain stimulation.</p>

Neuronal firing in the globus pallidus internus and the ventrolateral thalamus related to parkinsonian motor symptoms / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>It has been proposed that parkinsonian motor signs result from hyperactivity in the output nucleus of the basal ganglia, which suppress the motor thalamus and cortical areas. This study aimed to explore the neuronal activity in the globus pallidus internus (GPi) and the ventrolateral thalamic nuclear group (ventral oral posterior/ventral intermediate, Vop/Vim) in patients with Parkinson's disease (PD).</p><p><b>METHODS</b>Twenty patients with PD who underwent neurosurgery were studied. Microelectrode recording was performed in the GPi (n = 10) and the Vop/Vim (n = 10) intraoperatively. Electromyography (EMG) contralateral to the surgery was simultaneously performed. Single unit analysis was carried out. The interspike intervals (ISI) and coefficient of variation (CV) of ISI were calculated. Histograms of ISI were constructed. A unified Parkinson's disease rating scale (UPDRS) was used to assess the clinical outcome of surgery.</p><p><b>RESULTS</b>Three hundred and sixty-three neurons were obtained from 20 trajectories. Of 175 GPi neurons, there were 15.4% with tremor frequency, 69.2% with tonic firing, and 15.4% with irregular discharge. Of 188 thalamic neurons, there were 46.8% with tremor frequency, 22.9% with tonic firing, and 30.3% with irregular discharge. The numbers of three patterns of neuron in GPi and Vop/Vim were significantly different (P < 0.001). ISI analysis revealed that mean firing rate of the three patterns of GPi neurons was (80.9 +/- 63.9) Hz (n = 78), which was higher than similar neurons with 62.9 Hz in a normal primate. For the Vop/Vim group, ISI revealed that mean firing rate of the three patterns of neurons (n = 95) was (23.2 +/- 17.1) Hz which was lower than similar neurons with 30 Hz in the motor thalamus of normal primates. UPDRS indicated that the clinical outcome of pallidotomy was (64.3 +/- 29.5)%, (83.4 +/- 19.1)% and (63.4 +/- 36.3)%, and clinical outcome of thalamotomy was (92.2 +/- 12.9)%, (68.0 +/- 25.2)% and (44.3 +/- 27.2)% for tremor, rigidity and bradykinesia, respectively. A significant difference of tremor and rigidity was found between GPi and Vop/Vim (P < 0.05).</p><p><b>CONCLUSIONS</b>Different changes in neuronal firing rate and the pattern in GPi and Vop/Vim are likely responsible for parkinsonian motor signs. The results support the view that abnormal neuronal activity in GPi and Vop/Vim are involved in the pathophysiology of parkinsonism.</p>

Effect of simvastatin on the reserve of heart function and endothelial function in X-syndrome / 中南大学学报(医学版)

OBJECTIVE@#To determine the therapeutic effect of simvastatin combined with traditional medicine on patients with X-syndrome, and on the reserve of heart function and endothelial function.@*METHODS@#Forty patients with X-syndrome were recruited from September 2006 to September 2007 and randomly divided into 2 groups (a simvastatin group and a control group). The control group received routine treatment including beta receptor blocker, calcium-channel blocker (CCB) and long active nitrate. The simvastatin group received simvastatin and the routine treatment. The clinical condition and exercise test (TET) were performed before and after the treatment.The levels of triglyeride (TG), total cholesterol (TC), low density lipoprotein (LDL-C), high density lipoprotein (HDL-C), endothelin-1 (ET-1) and nitric oxide (NO) were measured.@*RESULTS@#The frequencies of chest pain in the simvastatin group were lower than those in the control group. The levels of ET-1, ET-1/NO, TG, TC, and LDL-C were significantly decreased in the simvastatin group as compared with the control group after the treatment. The levels of HDL-C and NO were significantly increased in the simvastatin group as compared with the control group after the treatment. The time in TET was significantly increased in the simvastatin group as compared with the control group. The frequencies of chest pain were positively related to the level of ET-1/NO and negatively related to the time in TET.@*CONCLUSION@#Simvastatin is effective for patients with X-syndrome and may improve the endothelial function and the reserve of heart function.

Phase transfer catalyzed bioconversion of penicillin G to 6-APA by immobilized penicillin acylase in recyclable aqueous two-phase systems with light/pH sensitive copolymers / 南方医科大学学报

Immobilized penicillin acylase was used for bioconversion of penicillin PG into 6-APA in aqueous two-phase systems consisting of a light-sensitive polymer PNBC and a pH-sensitive polymer PADB. Partition coefficients of 6-APA was found to be about 5.78 in the presence of 1% NaCl. Enzyme kinetics showed that the reaction reached equilibrium at roughly 7 h. The 6-APA mole yields were 85.3% (pH 7.8, 20 degrees C), with about 20% increment as compared with the reaction of single aqueous phase buffer. The partition coefficient of PG (Na) varied scarcely, while that of the product, 6-APA and phenylacetic acid (PA) significantly varied due to Donnan effect of the phase systems and hydrophobicity of the products. The variation of the partition coefficients of the products also affected the bioconversion yield of the products. In the aqueous two-phase systems, the substrate, PG, the products of 6-APA and PA were biased in the top phase, while immobilized penicillin acylase at completely partitioned at the bottom. The substrate and PG entered the bottom phase, where it was catalyzed into 6-APA and PA and entered the top phase. Inhibition of the substrate and products was removed to result in improvement of the product yield, and the immobilized enzyme showed higher efficiency than the immobilized cells and occupied smaller volume. Compared with the free enzyme, immobilized enzyme had greater stability, longer life-time, and was completely partitioned in the bottom phase and recycle. Bioconversion in two-phase systems using immobilized penicillin acylase showed outstanding advantage. The light-sensitive copolymer forming aqueous two-phase systems could be recovered by laser radiation at 488 nm or filtered 450 nm light, while pH-sensitive polymer PADB could be recovered at the isoelectric point (pH 4.1). The recovery of the two copolymers was between 95% and 99%.

Genetic instability detected by flow cytometry: DNA aneuploid and P16 expression in biopsy specimens from lung cancer / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate DNA aneuploid and P16 expression in biopsy specimens from lung cancer, and to study genetic instability and the application of flow cytometry in lung cancer pernicious degree diagnosis.</p><p><b>METHODS</b>Blood cells and cancer cells in biopsy specimens were marked simultaneously with anti-CD45 and anti-P16 fluorescent antibody, and the ratio of CD45+ P16+ cells and CD4- P16+ cells was compared. DNA content in biopsy specimens from lung cancer was detected by flow cytometry.</p><p><b>RESULTS</b>Among the 74 cases of lung cancer, there are 46 cases of DNA aneuploid (62.2%). Thirty-seven cases of lung cancer expressed P16 lowly (50%). Twelve cases of lung cancer only expressed P16 lowly (16.22%), 21 cases of lung cancer only expressed DNA aneuploid (28.38%), and 25 cases not only expressed P16 lowly but also expressed DNA aneuploid (33.78%). Indexes of malign degree, such as P16 low expression or DNA aneuploid could be detected in 58 cases among the 74 cases (78.38%) by flow cytometry.</p><p><b>CONCLUSION</b>P16 low expression and DNA aneuploid are the indexes of lung cancer malign degree, and flow cytometry can be used to study genetic instability and evaluate biopsy specimens from lung cancer.</p>

Expression of cardiotrophin-1 and effects of irbesartan in adriamycin induced cardiomyopathy in rats / 中南大学学报(医学版)

OBJECTIVE@#To investigate cardiotrophin-1(CT-1) expression in the ventricle and the effects of angiotensin II type I receptor antagonist (AT(1)RA) irbesartan on the ventricular remodeling in adriamycin myocardiopathy.@*METHODS@#Thirty male SD rats were randomized into 2 groups: a control group (n=10) and a model group (n=20). The model group was administered adriamycin and 18 rats survived. And theses rats were randomized again into 2 groups. One was treated with irbesartan [50 mg/(kg x d), with stomach-tube], and the other received equal saline, so did the control group. After 12 weeks, the protein level of CT-1 was detected by immunohistochemistry.@*RESULTS@#Ventricular CT-1 in the model control group and the treatment group was higher than that in the control group and the correlation analysis showed that ventricular CT-1 of the model control group was positively correlated with the left ventricular weight index, and CT-1 of the treatment group was lower than that of the model control group.@*CONCLUSION@#CT-1 was assumed to take part in the ventricular remodeling. The mechanism of irbesartan on the ventricular remodeling may be related to the downregulation of CT-1 expression.

The influence of controlling redox potential on ethanol production by Saccharomyces cerevisiae / 生物工程学报

Redox electrode was used to control redox potential at four different levels (-50 mV, -100 mV, -150 mV, - 230mV) for the study of ethanol fermentation. The result showed that there was notably influence on the yield of ethanol, the formation of glycerol, the secretion of organic acid, biomass and the death of cell by controlling redox potential at different levels. For example: the biomass of ORP at -50 mV was 1.26, 1.86, 2.59 times higher than ORP at -100 mV, -150 mV, -230 mV respectively, the final glycerol concentration was 1.2, 1.1, 1.7 times higher but final ethanol concentration was 0.87, 0.49, 0.51 times lower compared to the latest three ORP control level. And take biomass, ethanol yield, glycerol concentration, and unconsumed glucose into consider, we get the conclusion that it is very favorable for ethanol fermentation by control ORP at 150 mV. So it give us a apocalypse that we can use redox electrode to control the ethanol fermentation exactly on bioreactor scale.

Subtotal corpectomy through the pedicle for treating the burst fracture of thoracic vertebrae with paralysis / 中国矫形外科杂志

[Objective]To investigate the clinical curative effect and superiority of subtotal corpectomy through the pedicle,titanium rete support and pedicle screws system fixation in the treatment of burst fracture of thoracic vertebrae with paralysis.[Method]Twenty-three patients who suffered from the burst fracture of thoracic vertebrae with paralysis were treated with subtotal corpectomy through pedicle,titanium rete supporting bone autograft and pedicle screws system fixation.[Result]The patients were followed up for 8 months to 2 years.All had their bone grafts fused,and no incision infection,pneumothorax,hemothorax,pulmonary infection,internal fixation loosening or breakage occurred.The mean loss of Cobb's angle was 3.5?.According to Frankel grading,6 of grade A had no obvious recovery.In 5 of grade B,3 improved to C,1 to D,and the last one to E.In 7 of grade C,3 improved to D,4 to E.Five cases of grade D improved to E.[Conclusion]There had relatively less operation wound and good clinical curative effect with subtotal corpectomy through pedicle,titanium rete supporting bone autograft and pedicle screws system fixation.

Phase Transfer Bioconversion of Penicillin G into 6-APA by Immobilized Penicillin Acylase in Recycling Aqueous Two-phase Systems With Light-pH Sensitive Copolymers / 中国生物工程杂志

Immobilized penicillin acylase was used for bioconversion of penicillin G into 6-APA in aqueous two-phase systems consisted of a light-sensitive polymer PNBC and a pH-sensitive polymer PADB.Partition coefficients of 6-APA was found to be:about 5.78,in the presence of 1% NaCl.Enzyme kinetic showed that reaction reached equilibrium at 7h or so.The 6-APA mole yields were 85.3%(pH 7.8,and 20 ℃) and this value was about 20%higher than control in reaction of single aqueous phase buffer.Partition coefficient of penicillin G(Na) washardly changeable,while partition coefficient of product,6-APA and phenylacetate acid was significantly changeable.Reason is due to Donnan effect of phase systems andhydrophobicity of products.The change of partition coefficients of products also affects bioconversion yield of products.In the aqueous two-phase systems,substrate,penicillin G,products 6-APA and phenylacetate acid are biased in top phase,while immobilized penicillin acylase is completely partitioned in bottom.Substrate,penicillin G enters into bottom phase,and it is catalyzed into 6-APA and phenylacetate acid,then the products enter into top phase.Finally,inhibition of substrate and products is removed to result in improvement of products yield.Moreover,immobilized enzymehashigher efficiency than immobilized cells and occupy smaller volume.Comparing with free enzyme,immobilized enzymehashigher stability,longer use life,completely partitioned in bottom phase and recycle.Bioconversion in two-phase systems using immobilized penicillin acylase showed outstanding advantage.The light-sensitive copolymer forming aqueous two-phase systems could be recovered by laser radiation at 488 nm or filtrated 450 nm light,while pH-sensitive polymer PADB could be recovered by isoelectric point(pH 4.1).The recovery of the two copolymers was 95%~99%.

Over-expression in Escherichia coli and characterization of apolipoprotein AI / 生物工程学报

Apolipoprotein AI (apo AI), the major protein component of human high-density lipoprotein (HDL), is a single-chain polypeptide of 243 amino acids. Several epidemiological studies have shown that the plasma concentrations of HDL has the role of reverse cholesterol transport (RCT) and inversely correlated with the incidence of coronary artery disease. Because apo AI lacks post-translational modifications, it is convenient to express human apo AI in Escherichia coli expression system. However, there is a poor stability of the mRNA and the apo AI protein in E. coli, it is difficult to express mature apo AI in recombinant bacteria, moreover, even as a fusion protein, apo AI is still sensitive to degradation and can not be cleaved efficiently from the fusion tags. In contrast, proapolipoprotein AI (proapo AI, having an additional polypeptide containing the amino acids Arg-His-Phe-Trp-Gln-Gln at the amino-teminal of the mature protein) proved stable and undegraded in Escherichia coli, and therefore, in this research, an expression system of E. coli including a plasmid of P(R)P(L) tandem promoter was adapted to produce proapo AI. Furthermore, site-directed mutagenesis of the proapo AI cDNA was performed to generate a Clu8Asp mutation in the amino-terminal sequence of proapo AI which created an acid labile Asp-Pro peptide bond between amino acid 8 and 9, and permitted specific chemical cleavage to remove pro-peptide. After inducing with a shift of temperature, yields of recombinant proapo AI achieved about 40% of total cell protein and the recombinant proapo AI expressed proved as a form of inclusion body in cells, so protein need to renature. First of all, the protein was dissolved in buffer with denaturant, and renaturation was carried out on a hydrophobic interaction column (Phenyl Sepharose), ion-exchange chromatography and gel-filtration chromatography were then used to further purify the protein. The purified recombinant apo AI was detected by a set of tests including Western-blotting, Circular dichroism spectra and lipid-binding test, the results shown that recombinant apo AI has similar structural and lipid-binding properties identical to those of native plasma apo AI, which facilitates further research and application.

A study on outcome and mechanism of surgical treatment for Tourette's syndrome / 中华外科杂志

<p><b>OBJECTIVE</b>To evaluate the efficacy and safety of unilateral pallidotomy in treating Tourette syndrome (TS). The therapeutic electrophysiological mechanism of pallidotomy was analyzed according to the properties of GPi cells in TS.</p><p><b>METHODS</b>Twenty-two patients underwent microelectrode-guided unilateral pallidotomy. All patients referred to surgery were previously failed with multiple non-surgical methods (psychopharmacological and behavioural therapy). Pre- and postoperative tic severities were rated by the Yale global tic severity scale (YGTSS). With the microelectrode recording technique, the properties of GPi cells in 6 patients were recorded and analyzed.</p><p><b>RESULTS</b>(1) Postoperative scores of motor tics, phonic tics, overall impairment rating and global severity in YGTSS were significantly decreased (P < 0.01). The amelioration of phonic tics was less than motor tics. The follow-up data at 12 months revealed a stable efficacy. Five cases experienced transient complications included drowsiness, intracranial pneumatocele, incontinence, diplopia and slightly facial palsy after pallidotomy, there were no permanent complications such as death, intracranial, hematoma hemiplegia and visual field defect. (2) The discharge rates of GPi neurons ranged from 20 to 156 Hz, the discharge patterns include regular, irregularly bursting and clustering mode. The synchronizations of neuronal discharge in GPi with the activities of contralateral limbs were observed also by electromyogram recorded at the same term.</p><p><b>CONCLUSIONS</b>(1) Pallidotomy is proven to be a safe and effective method to treat TS, it provides a significant immediate and short term reduction of tic severity in intractable Tourette' syndrome. The long term effect of pallidotomy is confirmed also. Pallidotomy is applied to those patients with high tics scores, severe self-injured behaviors or fail to medicine treatment. (2) The low discharge rate, abnormal firing pattern and synchronized neuron are the properties of GPi neurons in TS, and maybe the pathophysiological basement of tics. Eliminated the neurons with abnormal activity in GPi, and decreased the activity of CSTC circuits maybe the therapeutic mechanism of pallidotomy.</p>

Quantitative studies of the production phase in rHSA fermentation / 生物工程学报

The model equations of the production phase of rHSA fermentation were derived on the base of both elemental balance and metabolic balance, then the unknown parameters of the model were estimated by multivariable optimization. The possible reasons of discrepancy of production rate between different period of fermentation were discussed. The model could preferably described the relations between different macroscopic reaction rates of the process and keys for the high-efficiency expression of HAS were deduced.

Application of element and metabolism balancing for the cultivation process with Streptomyces aureofaciens / 生物工程学报

On the base of element and metablism balancing, the mathematical model of the cultivation process with Streptomyces aureofaciens was developed, and the unknown parameters in the model were estimated with the method of nonlinear optimization. Firstly the energetic coefficient of CTC biosynthesis was gained, which was 1.8 - 2.8 mol-ATP x C-mol(-1). The macroscopic reaction rates were predicted in the process and compared with the experimental values. The results show that the model can preferably describe the relationships between several macroscopic reaction rates in the process and can supervise the optimization of CTC fermentation process theoretically.