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L-2-aminobutyric acid (L-ABA) is an important chemical raw material and chiral pharmaceutical intermediate. The aim of this study was to develop an efficient method for L-ABA production from L-threonine using a trienzyme cascade route with Threonine deaminase (TD) from Escherichia. coli, Leucine dehydrogenase (LDH) from Bacillus thuringiensis and Formate dehydrogenase (FDH) from Candida boidinii. In order to simplify the production process, the activity ratio of TD, LDH and FDH was 1:1:0.2 after combining different activity ratios in the system in vitro. The above ratio was achieved in the recombinant strain E. coli 3FT+L. Moreover, the transformation conditions were optimized. Finally, we achieved L-ABA production of 68.5 g/L with a conversion rate of 99.0% for 12 h in a 30-L bioreactor by whole-cell catalyst. The environmentally safe and efficient process route represents a promising strategy for large-scale L-ABA production in the future.
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Aminobutyrates , Bacillus thuringiensis , Candida , Escherichia coli , Formate Dehydrogenases , Metabolism , Leucine Dehydrogenase , Metabolism , Threonine , Metabolism , Threonine Dehydratase , MetabolismABSTRACT
Objective@#To investigate the effects of Helicobacter pylori (HP) radical treatment on diagnosis of early gastric cancer using conventional white light endoscopy (WLE), chromoendoscopy of indigo carmine dye added to acetic acid, and magnifying endoscopy with narrow band imaging (ME-NBI).@*Methods@#Between January 2013 and March 2018, patients without HP (successful cured before six months) or with HP (no radical treatment for HP in recent 6 months), who underwent endoscopy examinations in the Department of Gastroenterology of Ezhou Hospital, People′s Hospital of Wuhan University or the Department of Gastroenterology of Union Hospital, Tongji Medical College Huazhong University of Science and Technology were enrolled in the study. Endoscopy examinations were performed according to the order of conventional WLE, chromoendoscopy using indigo carmine dye added to acetic acid, and ME-NBI. Among the patients finally diagnosed as early gastric cancer by histopathology, 120 patients without HP and 120 patients with HP were continuously collected, and included in the radical treatment group and the non-radical treatment group, respectively. Diagnostic reliabilities of WLE, chromoendoscopy, and ME-NBI for early gastric cancer between the two groups were statistically analyzed.@*Results@#There were no statistical differences between the two groups in terms of hospital source (χ2=2.637, P=0.104), gender composition (χ2=0.074, P=0.785), mean age (t=0.582, P=0.561), and lesion morphology (χ2=0.179, P=0.914). The detection rates of early gastric cancer in the radical treatment group using WLE [75.0% (80/120) VS 81.7% (98/120), χ2=7.046, P=0.008], chromoendoscopy [57.5% (69/120) VS 93.3% (112/120), χ2=41.554, P<0.001], and ME-NBI [90.0% (108/120) VS 98.3% (118/120), χ2=7.585, P=0.006] were significantly lower than those in the non-radical treatment group. In the radical treatment group, chromoendoscopy had the lowest detection rate of early gastric cancer, followed by WLE (χ2=2.142, P=0.143) and ME-NBI (χ2=32.736, P<0.001), while ME-NBI had the highest detection rate of early gastric cancer, which higher than that of WLE (χ2= 19.247, P<0.001).@*Conclusion@#The diagnosis of early gastric cancer by WLE, chromoendoscopy using the indigo carmine dye added to acetic acid and ME-NBI becomes more difficult after radical treatment of HP. Among the above three endoscopic methods, ME-NBI has the highest diagnostic efficacy, and becomes the first choice for the clinical diagnosis of early gastric cancer after radical treatment of HP.
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Objective To investigate the effects of Helicobacter pylori (HP) radical treatment on diagnosis of early gastric cancer using conventional white light endoscopy ( WLE ) , chromoendoscopy of indigo carmine dye added to acetic acid, and magnifying endoscopy with narrow band imaging (ME-NBI). Methods Between January 2013 and March 2018, patients without HP (successful cured before six months) or with HP ( no radical treatment for HP in recent 6 months ) , who underwent endoscopy examinations in the Department of Gastroenterology of Ezhou Hospital, People's Hospital of Wuhan University or the Department of Gastroenterology of Union Hospital, Tongji Medical College Huazhong University of Science and Technology were enrolled in the study. Endoscopy examinations were performed according to the order of conventional WLE, chromoendoscopy using indigo carmine dye added to acetic acid, and ME-NBI. Among the patients finally diagnosed as early gastric cancer by histopathology, 120 patients without HP and 120 patients with HP were continuously collected, and included in the radical treatment group and the non-radical treatment group, respectively. Diagnostic reliabilities of WLE, chromoendoscopy, and ME-NBI for early gastric cancer between the two groups were statistically analyzed. Results There were no statistical differences between the two groups in terms of hospital source (χ2 =2. 637, P=0. 104) , gender composition (χ2=0. 074, P=0. 785) , mean age ( t=0. 582, P=0. 561) , and lesion morphology (χ2 = 0. 179, P= 0. 914 ) . The detection rates of early gastric cancer in the radical treatment group using WLE [ 75. 0％( 80/120 ) VS 81. 7％( 98/120 ) ,χ2 = 7. 046, P = 0. 008 ] , chromoendoscopy [ 57. 5％( 69/120 ) VS 93. 3％( 112/120 ) ,χ2 =41. 554, P<0. 001 ] , and ME-NBI [ 90. 0％( 108/120) VS 98. 3％( 118/120) ,χ2=7. 585, P=0. 006] were significantly lower than those in the non-radical treatment group. In the radical treatment group, chromoendoscopy had the lowest detection rate of early gastric cancer, followed by WLE (χ2=2. 142, P=0. 143) and ME-NBI (χ2=32. 736, P<0. 001) , while ME-NBI had the highest detection rate of early gastric cancer, which higher than that of WLE (χ2= 19.247, P<0.001). Conclusion The diagnosis of early gastric cancer by WLE, chromoendoscopy using the indigo carmine dye added to acetic acid and ME-NBI becomes more difficult after radical treatment of HP. Among the above three endoscopic methods, ME-NBI has the highest diagnostic efficacy, and becomes the first choice for the clinical diagnosis of early gastric cancer after radical treatment of HP.
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Objective To evaluate the clinical efficacy of ventricle -peritoneal or ventricle-atrial shunt in the treatment of skull defect with craniocerebral trauma combined with hydrocephalus in the same period. Methods Sixty-four patients with skull defect after craniocerebral trauma combined with hydrocephalus were randomly divided into observation group (n=32) and control group (n=32) The ventricle-peritoneal or ventricle-atrial shunt and skull repair were conducted simultaneously following surgical operation in observation group whereas ventricle-peritoneal or ventricle-atrial shunt and the skull defect were performed within 3 months and after 3 months following operation, respectively. The hydrocephalus symptoms, prognosis after three months ,clinical outcomes and the postoperative complications were evaluated. Results There was no significant difference in hydrocephalus symptoms between the observation group and control group (χ2=0.005,P>0.05). The GCS score, GOS score and neurological function score after three months were better than those before the treatment in these two groups (P<0.05). These functional parameters were significantly better in the observation group than in control group (P<0.05). The good rate in three months was significantly higher in the observation group than in control group (59.38％vs 31.25％,χ2=7.23, P<0.05). The incidence of complication was 6.25％(2/32) in the observation group, which was significantly lower than that in the control group (31.25％, 10/32) (χ2=7.13, P<0.05).Conclusion Cranioplasty combined with shunt in the treatment of skull defect complicated with craniocerebral trauma-associated hydrocephalus has low postoperative complications, good clinical prognosis and reliable efficacy, which is worthy of clinical application.
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Community-acquired pneumonia (CAP) is a common respiratory infectious disease.The etiologic diagnosis of CAP remains an uneasy task.Early etiologic diagnosis is critical for proper treatment and might improve the prognosis.So,it is important to identify pathogens causing CAP in early time and accurate way with sensitive and effective method.This paper summarizes the recent progress in the research of the detection assay for CAP.
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Community-acquired pneumonia (CAP) is a common respiratory infectious disease.The etiologic diagnosis of CAP remains an uneasy task.Early etiologic diagnosis is critical for proper treatment and might improve the prognosis.So,it is important to identify pathogens causing CAP in early time and accurate way with sensitive and effective method.This paper summarizes the recent progress in the research of the detection assay for CAP.
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The incidence of colorectal cancer is rising year by year, thus screening of neoplastic colorectal polyps is very important for the prevention and treatment of colorectal cancer. In recent years, endoscopic techniques have advanced dramatically, such as high definition endoscopy, magnified endoscopy, conventional or virtual chromoendoscopy. Some of these technologies not only can improve the adenoma detection rate, but also may help to enable real-time endoscopic diagnosis and thereby guide decisions about endoscopic resection. The second generation colon capsule endoscopy provides a new and relative reliable noninvasive tool for colorectal diseases screening and diagnosis. This article aims to provide a comprehensive review of advanced imaging techniques available for the detection and differentiation of colorectal polyps.
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Humans , Adenoma , Diagnosis , Colonoscopy , Colorectal Neoplasms , Diagnosis , Polyps , DiagnosisABSTRACT
BACKGROUND:Recent studies have found that bone marrow mesenchymal stem cels that culturedin vitro for a long time can naturaly differentiate into neural stem cels, which then differentiate into neurons and glial cels, thereby providing a new therapeutic thinking for Parkinson’s disease, sequela of cerebral infarction, cerebelar atrophy and brain dysplasia. OBJECTIVE:To discuss the influence of neural stem cel transplantation on neurologic function of rats with cerebral hemorrhage at recovery stage and the relevant mechanism of action. METHODS: Sixty male Sprague-Dawley rats were randomly divided into normal group (n=18), cerebral hemorrhage group (n=21) and transplantation group (n=21). Cerebral hemorrhage models were established in the latter two groups using VII type colagen enzyme induction method. At 21 days of modeling, rats in the transplantation group were injected neural stem cels via the tail vein, and those in the other two groups received the same volume of normal saline. At 7, 14, 21 days after cel transplantation, modified adhesive removal test (MST) was employed to evaluate the neurologic function of rats, and then the rats were kiled. RT-PCR was used to detect angiopoietin-1 mRNA expression in the bleeding tissues, and western blot assay was employed to measure tyrosine kinase receptor-2 protein expression. RESULTS AND CONCLUSION:Compared with the normal group, the MST scores in the cerebral hemorrhage group and transplantation group were significantly decreased (P cerebral hemorrhage group > normal group, and there was a significant difference among the three groups (P< 0.05). These findings indicate that neural stem cel transplantation can effectively promote the neurologic recovery of rats with cerebral hemorrhage at recovery stage, and the concrete mechanism may be related to the increase of angiopoietin-1 mRNA and tyrosine kinase receptor-2 protein in the bleeding tissues.
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were no significant differences in the detection rate of recto-sigmoid colon,mid colon,right colon and total detection of polyps among the 3 groups (P >0.05).Conclusion 4-L split-dose PEG is better than the oth-er 2 regimens in the colon cleansing quality,so it can better reach the intestinal cleaning standards before enteroscopy,which is a more suitable regimen for bowel preparation.
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Objective To investigate the therapeutic effect of autologous stem cell transplantation research for patients with cerebral hemorrhage sequelae under the stereotactic.Methods One hundred patients with cerebral hemorrhage from Jan.2011 to Sep.2013 in our hospital were selected and randomly divided into the experimental group (n =50) and the control group (n =50).The patients of experimental group were given autologous stem cell transplantation under the stereotactic in 6 months after cerebral hemorrhage,while the patients in control group were just given traditional treatment.At 6,7 and 12 months after cerebral hemorrhage,rate with neural function defect scale and functional independence measure(FIM) scores of the two groups were compared.Results FIM scores in the experimental group was 102.08 ± 8.28,significant higher than that in control group(95.28±8.75,P＜0.05).Functional independence measure scores in the experimental group at 7 months after cerebral hemorrhage was 13.12±4.00,significant lower than that in control group(20.40±4.33,P ＜0.05).While,there was no statistical difference at 6 months and 12 months after cerebral hemorrhage between the two groups(P＞0.05).Conclusion The therapeutic of autologous stem cell transplantation on patients with cerebral hemorrhage sequelae under the stereotactic is benefit at short term,but the long term therapy effective still needs further study.
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Objective To investigate the clinical application prospect of water exchange colonoscopy.Methods A total of 300 outpatients who underwent unsedated colonoscopy were randomized to the WEC group (n =150)or the AIC group(n =150).The maximum pain score, insertion time, the cecal intubation rate and the polyp detection rate were reported by an assistant during the insertion phase and at the end of colonoscopy.Results The maximum abdominal pain scores were 1.77 ± 1.29 in the WEC group and 2.84 ± 1.55 in the AIC group with significant difference (P =0.000).The intubation time of WEC was longer than that of AIC (11.91 ± 3.58 VS 8.03 ± 3.19 ,P =0.000)with no significant difference.There was no significant difference in the cecal access rate between the two groups(97.3％ VS 94.0％ ,P =0.157).The polyp detection of WEC was higher than that of AIC (16.7％ VS 10.0％, P =0.089).In the post abdominal operation subject of colonoscopy procedure, WEC had higher rate of cecal intubation than AIC ,the maximum abdominal pain score were 2.25 ± 1.63 in the WEC group,lower than 3.48 ± 1.45 in the AIC group.Conclusion Water exchange colonoscopy can alleviate patients' abdominal pain symptoms, but with longer insertion time.There are no significant difference in the cecal access rate and the polyp detection rate between two groups.For difficult colonoscopy, water exchange colonoscopy is helpful to increase the rate of cecal intubation.
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Objective To analyze recent 30 years’ regularities in point selection for acupuncture treatment of Parkinson disease and provide reference for its treatment. Methods Parkinson disease, parkinsonism and acupuncture were used as key words. Recent 30 years’ Chinese literature was searched using Wanfang, CNKI, VIP and Chinese biomedical literature database. Selection of main acupoints and scalp acupuncture points, syndrome differentiation-based point selection and meridian tropism of main acupoints were metrologically studied. Results The Du meridian, the large intestine meridian and the gallbladder meridian were mainly selected for acupuncture treatment of Parkinson disease. Taichong(LR3), Baihui(GV20), Hegu(LI4) and Fengchi(GB20) were used as main points. Chorea-tremor control area, motor area and parietotemporal anterior oblique line were often selected as main scalp acupuncture points. Fenglong (ST40), Qihai(CV6), Sanyinjiao(SP6), Yinlingquan(SP9) and Zusanli(ST36) were often used according to syndrome differentiation-based point selection. Conclusion Modern acupuncture doctors select Taichong(LR3), Baihui(GV20), Hegu(LI4) and Fengchi(GB20) as main points, often use scalp acupuncture points and combine points mainly from the Du meridian according to syndrome differentiation in the treatment of Parkinson disease.
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Objective To compare the accuracy of cone-beam computed tomography (CBCT ) and periapical radiography in the diagnosis of simulated external apical root resorption (EARR) .Methods The study sample comprised 160 single-rooted premolars for simulating 4 degrees of EARR :no(intact teeth) ,mild(cavity of 1 .0 mm in diameter and depth in root surface) ,moderate(1 .0 mm root shortening) ,and severe(3 .0 mm root shortening) .Two sets of radiographic images were acquired with CBCT and periapi-cal radiography .The severity for all resorption lesions were evaluated blindly by one calibrated examiner .The percentages of correct classification of each degree of EARR were compared between the two imaging techniques using McNemar test .Results With CBCT method ,the percentages of correct classification of no ,mild ,moderate ,severe and all EARR were 95 .0% ,97 .5% ,42 .5% , 87 .5% and 80 .6% ,respectively ;with periapical radiography method ,the percentages were 85 .0% ,42 .5% ,70 .0% ,92 .5% and 72 .5% ,respectively .Significant differences were found between the two imaging techniques for evaluating mild ,moderate ,and all-EARR(P<0 .05) .Conclusion CBCT imaging is more reliable than periapical radiography for detecting EARR ,whereas it is not sensitive to moderate root shortening .In orthodontic practices ,CBCT could be applied to the early diagnosis of EARR ,in order to help make the decision on continuation and modification of orthodontic treatment .
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In this study,the L.dumoffii TEX-KL (ATCC 33343),L.dumoffii NY23 (ATCC 33279) and L.pneumophila philadelphila-1 (ATCC 33155) strains were used to explore the adhesion,invasion and intracellular growth ability in the epithelial cells.Approximately 1× 108 bacteria were pelleted,resuspended,and diluted (1 ∶ 10) in RPMI 1640 tissue culture medium.The bacteria were then added to A549 cells (1 × 105 per well) in 24-well plates to give a multiplicity of infection (MOI) of about 100.The Gimenez staining and colony counting methods were used for the determination of the strain adhesion,invasion and intracellular growth ability.It was found that in vitro growth ability of L.pneumophila philadelphila-1,L.dumoffii TEX-KL and L.dumoffii NY23 strains had no significant difference.For in vivo assay,there was also no significant difference in adhesion ability of these strains.However,the CFU counts of L.dumoffii TEX-KL strain invaded into A549 cells was 1 000 times higher than that of the other two strains.Compared with L.pneumophila philadelphila-1 and L.dumoffii NY23 strains,L.dumoffii TEX-KL strain has higher invasion ability and,therefore,higher intracellular growth ability.
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objective To investigate the epidemiological and molecular typing features of the pathogenic Haemophilus influenzae(H.influenzae)by biotyping,serotyping and pulsed-field gel electrophoresis(PFGE).Methods A total of 273 invasive isolates of H influenzae were collected from the pediatric patients with pneumonia at Chengdu Children Hospital of Sichuan province from 1988 and 2004 to 2007.The idenbfication of H.influenzae strains were done according to the laboratory standard methodology described by Manual of Clinical Microbiology(American).All strains were biotyped according to Kilian's classification with the API[R]NH system.And serotyped by a slide agglutination assay with type a to f specific antlaerum as described by Pittman.PCR method for identification of H.influenzae were performed as described by Falla.One hundred of 273 strains were analyzed by PFGE as described by Saito with some modifications.The resuIts of PFGE were analyzed by Bionumerics soft(Version 4.0,Applied Maths BVBA,Belium).Restilts 78.2%of 273 cases occurred under 1 years old.Eight biotypes were found among the 273 H.influenzae isolates.17.6%(48/273)of all isolates belonged to biotype Ⅰ,43.6%(119/273)were biotype Ⅱ,22.7%(62/273)were biotype Ⅲ,7.3%(20/273)were biotype Ⅳ,5.9%(16/273)were biotype Ⅴ,0.4%(1/273)were biotype Ⅵ,1.8%(5/273)were biotype Ⅶ and 0.7%(2/273)were biotype Ⅷ.respeetively.99.6% of all 273 isolates were nontypeable.There was only one isolate was serotvpe f Ninty-six PFGE genotypes were obtained in this study.One hundred strains demonstrated a variety of genomic Datterns by PFGE.The most isolates of the flame PFGE genotype(type 35)was 3 isolates.Each of93 PFGE genotypes was represented by only a single isolate.The genotypes distribution didn't correlate with the time distribution of the strains were isolated.Conclusion Nontypeable H.influenzae primarily caused acute Dneumoma in children under 1 years old.They mostly belonged to biotype Ⅰ,Ⅱ and Ⅲ biotypes.The nontypeable H.influenzae strains appeared to more heterogeneous patterns by PFGE genotyping.Genotyping may helP understand the molecular characteristics of outbreak and endemicity according to the results of PFGE.PFGE genotyping proved to have a much stronger discriminatory power than either serotyping or biotyping.Our findings suggest that PFGE analysis is useful for the epidemiologieal study of H.influenzae infections.
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Objective To establish TaqMan real-time PCR method for detection and identification of Haemophilus influenzae and Streptococcus pneumonia. Methods Two sets of primers and FAM-labeled probes targeting different genes of Haemophilus influenzae and Streptococcus pneumoniae were designed and synthesized. The bexA gene was used for identification of Haemophilus influenzae and lytA for Streptococcus pneumoniae. The sensitivity and specificity of real-time PCR were assessed for different primers and probes. Cut-off values of cycle threshold (Ct) were determined. Two hundred and seventy-eight cerebrospinal fluid (CSF) specimens from suspected bacterial meningitis cases were detected by real-time PCR assay, latex agglutination test and bacteria culture simultaneously. Results Haemophilus influenzae isolates of serotype a to d could be detected and identified by bexA primers and probe. All Streptococcus pneumoniae isolates of different serotypes could be detected and identified by lytA primers and probe. The respective sensitivities for Haemophilus influenzae and Streptococcus pneumoniae were 10 and 90 genome DNA copies in each PCR reaction. Of the 278 CSF specimens, four were positive by Haemophilus influenzae and seven positive by Streptococcus pneumoniae when detected by real-time PCR. Of the four Haemophilus influenzae positive specimens, two were positive by culture and one positive hy latex. Of the seven Streptococcus pneumonia positive specimens, two were positive by culture and two positive by latex. Conclusions Real-time PCR could rapidly detect and identify Haemophilus influenzae of serotype a to d and Streptococcus pneumoniae of different serotypes with high sensitivity. TaqMan real-time PCR could be widely used for the diagnosis of invasive meningitis caused by Haemophilus influenzae and Streptococcus pneumoniae. It can improve the rate of positivity for diagnosis of suspicious bacterial meningitis cases.
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In this study, the mechanism by which Suramin inhibits the replication of epidemic encephalitis B virus was explored to provide a theoretical basis for its further application in clinical practice. After viral infection of HepG2 and IMR-32 cells, different concentrations of Suramin were added to the culture media, and then the cultural supernatants and infected cells were collected 48 h later. For the evaluation of the curative effect, cytopathic effect (CPE), virus titers, the expression of viral protein and viral RNA were determined by Western blot, RT-PCR and in vitro RNA synthesis, respectively. At the concentration of 50 microg/ml of Suramin, HepG2 and IMR-32 infected with epidemic encephalitis B virus decreased by 51.8% and 0.03% respectively, as compared with controls. It was suggested that expression of encephalitis B virus proteins NS3 and E was notably reduced by Suramin. This is especially true of E protein. At RNA level, however, no difference in RNA virus was found between Suramin-treated virus and non-treated cells. Our results suggest that Suramin can inhibit viral replication by blocking the production of viral proteins.