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1.
Chinese Journal of Otorhinolaryngology Head and Neck Surgery ; (12): 579-588, 2023.
Article in Chinese | WPRIM | ID: wpr-986930

ABSTRACT

Objective: This cross-sectional investigation aimed to determine the incidence, clinical characteristics, prognosis, and related risk factors of olfactory and gustatory dysfunctions related to infection with the SARS-CoV-2 Omicron strain in mainland China. Methods: Data of patients with SARS-CoV-2 from December 28, 2022, to February 21, 2023, were collected through online and offline questionnaires from 45 tertiary hospitals and one center for disease control and prevention in mainland China. The questionnaire included demographic information, previous health history, smoking and alcohol drinking, SARS-CoV-2 vaccination, olfactory and gustatory function before and after infection, other symptoms after infection, as well as the duration and improvement of olfactory and gustatory dysfunction. The self-reported olfactory and gustatory functions of patients were evaluated using the Olfactory VAS scale and Gustatory VAS scale. Results: A total of 35 566 valid questionnaires were obtained, revealing a high incidence of olfactory and taste dysfunctions related to infection with the SARS-CoV-2 Omicron strain (67.75%). Females(χ2=367.013, P<0.001) and young people(χ2=120.210, P<0.001) were more likely to develop these dysfunctions. Gender(OR=1.564, 95%CI: 1.487-1.645), SARS-CoV-2 vaccination status (OR=1.334, 95%CI: 1.164-1.530), oral health status (OR=0.881, 95%CI: 0.839-0.926), smoking history (OR=1.152, 95%CI=1.080-1.229), and drinking history (OR=0.854, 95%CI: 0.785-0.928) were correlated with the occurrence of olfactory and taste dysfunctions related to SARS-CoV-2(above P<0.001). 44.62% (4 391/9 840) of the patients who had not recovered their sense of smell and taste also suffered from nasal congestion, runny nose, and 32.62% (3 210/9 840) suffered from dry mouth and sore throat. The improvement of olfactory and taste functions was correlated with the persistence of accompanying symptoms(χ2=10.873, P=0.001). The average score of olfactory and taste VAS scale was 8.41 and 8.51 respectively before SARS-CoV-2 infection, but decreased to3.69 and 4.29 respectively after SARS-CoV-2 infection, and recovered to 5.83and 6.55 respectively at the time of the survey. The median duration of olfactory and gustatory dysfunctions was 15 days and 12 days, respectively, with 0.5% (121/24 096) of patients experiencing these dysfunctions for more than 28 days. The overall self-reported improvement rate of smell and taste dysfunctions was 59.16% (14 256/24 096). Gender(OR=0.893, 95%CI: 0.839-0.951), SARS-CoV-2 vaccination status (OR=1.334, 95%CI: 1.164-1.530), history of head and facial trauma(OR=1.180, 95%CI: 1.036-1.344, P=0.013), nose (OR=1.104, 95%CI: 1.042-1.171, P=0.001) and oral (OR=1.162, 95%CI: 1.096-1.233) health status, smoking history(OR=0.765, 95%CI: 0.709-0.825), and the persistence of accompanying symptoms (OR=0.359, 95%CI: 0.332-0.388) were correlated with the recovery of olfactory and taste dysfunctions related to SARS-CoV-2 (above P<0.001 except for the indicated values). Conclusion: The incidence of olfactory and taste dysfunctions related to infection with the SARS-CoV-2 Omicron strain is high in mainland China, with females and young people more likely to develop these dysfunctions. Active and effective intervention measures may be required for cases that persist for a long time. The recovery of olfactory and taste functions is influenced by several factors, including gender, SARS-CoV-2 vaccination status, history of head and facial trauma, nasal and oral health status, smoking history, and persistence of accompanying symptoms.


Subject(s)
Female , Humans , Adolescent , SARS-CoV-2 , Smell , COVID-19/complications , Cross-Sectional Studies , COVID-19 Vaccines , Incidence , Olfaction Disorders/etiology , Taste Disorders/etiology , Prognosis
2.
Chinese Journal of Otorhinolaryngology Head and Neck Surgery ; (12): 26-32, 2021.
Article in Chinese | WPRIM | ID: wpr-942382

ABSTRACT

Objective: To investigate the diagnosis and surgical treatment of patients with soft tissue necrosis of cranial base after radiotherapy for nasopharyngeal carcinoma (NPC). Methods: The clinical data of 7 NPC patients with soft tissue necrosis but not bone necrosis after radiotherapy were retrospectively analyzed.They were treated in Xiangya Hospital from 2015 to 2019. The clinical manifestations, diagnosis, treatment and prognosis were analyzed. The major clinical symptoms of the 7 patients were headache in 7 cases, hearing loss in 7 cases, long-term nasal malodor in 5 cases and epistaxis in 2 cases. All patients underwent high-resolution CT, MR and magnetic resonance angiography (MRA) before operation. All cases were treated with extended transnasal endoscopic approach under general anesthesia for resection of necrotic tissue. Five cases had their affected cartilaginous segments of the eustachian tubes partially or completely resected, 7 cases were treated with myringotomy and tube insertion, and 1 case was treated with pansinusectomy. Anti-inflammatory treatment were carried out during the perioperative period. The recovery of patients was observed and recorded through regular follow-up (from 6 months to 3 years) after the operation. Results: Nasopharynx soft tissue lesions can be seen in seven patients with bone cortex integrity by CT, and small bubble shadow can be seen at junction area between skull base soft tissue lesions and skull base bone surface.MR and MRA examination showed extensive inflammatory changes of nasopharynx. Parapharyngeal irregular necrotic cavity was found in 6 cases without central enhancement, demonstrating edema of surrounding soft tissue. The necrotic tissue of all 7 patients was surgically removed. Postoperative pathological examinations confirmed that all of them were necrotic soft and cartilaginous tissue, without tumor recurrence. The symptoms of all patients were significantly alleviated after operation. Headache was cured in 5 cases and relieved in 2 cases. Nasal malodor was cured in 4 cases and alleviated in 1 case. During the follow-up period, 5 patients survived, and 2 patients who had their eustachian tube reserved died. One of them died of nasopharyngeal hemorrhage caused by recurrent nasopharyngeal necrosis 3 months after the operation. Another case died of severe intracranial infection 6 months after operation. Conclusions: The diagnosis of skull base soft tissue necrosis after radiotherapy for nasopharyngeal carcinoma needs comprehensive analysis of radiotherapy history, clinical manifestations and imaging examination. High resolution CT, MR and MRA of skull base are very important for diagnosis. Early active removal of large-scale necrotic lesions under endoscope and partial or total resection of eustachian tube cartilage according to the involvement of eustachian tube cartilage is effective means of controling skull base soft tissue necrosis after radiotherapy. The effective means of necrosis can improve the quality of life of patients.


Subject(s)
Humans , Nasopharyngeal Carcinoma , Nasopharyngeal Neoplasms/surgery , Necrosis , Neoplasm Recurrence, Local , Quality of Life , Retrospective Studies , Skull Base
3.
Acta Academiae Medicinae Sinicae ; (6): 778-786, 2019.
Article in Chinese | WPRIM | ID: wpr-781661

ABSTRACT

To explore the molecular mechanism underlying gastric carcinogenesis and progression by using gene expression profiling array together with bioinformatics. Lentivirus short hairpin RNA targeting STIL(ShSTIL)and scrambled sequence RNA(ShCon)were transduced into the gastric cancer cell line SGC-7901.RNA extraction,complementary DNA synthesis,construction of biotin-labelled amplified RNA probes,and hybridization with gene expression profile were consecutively performed.We collected corresponding data and analyzed differentially expressing genes(DEGs),followed by the analysis of gene ontology(GO)and Kyoto encyclopedia of genes and genomes(KEGG)enrichment,transcription factor regulating network,and protein-protein interacting networks. Compared with ShCon,a total of 417 and 87 genes were respectively down-regulated and up-regulated,respectively,in the ShSTIL group(1 or <-1).GO and KEGG enrichment analysis indicated that genes regulated by STIL were localized in cytoplasm,extracellular exosome,Golgi apparatus and various biomembranes,and were implicated in the ubiquitin-mediated proteolysis,P53 signaling pathway,and pathways regulating pluripotency of stem cells.Evaluation on genes enriched in KEGG pathways,regulation of transcription factors,and protein-protein interacting network demonstrated that IGF1R,STUB1,SKP2,and FOXO1 were localized at the centre of the network and played a key role in the development and progression of gastric cancer. Through the protein-protein interactions,STIL may activate E3 ubiquitin ligase STUB1 or SKP2,promote the proteolysis of FOXO1-a transcription factor,regulate the expression of IGF1R,and thus promote gastric carcinogenesis and progression.


Subject(s)
Humans , Computational Biology , Gene Expression Profiling , Gene Ontology , Stomach Neoplasms , Genetics , Transcriptome
4.
Chinese Journal of Otorhinolaryngology Head and Neck Surgery ; (12): 654-657, 2013.
Article in Chinese | WPRIM | ID: wpr-301417

ABSTRACT

<p><b>OBJECTIVE</b>To evaluate the surgical technique and efficacy of the resection of parapharyngeal space neoplasm via styloid diaphragm approach.</p><p><b>METHODS</b>Thirty-three cases underwent the resection of parapharyngeal space tumors via styloid diaphragm approach from Jan 2005 to Jan 2011 were reviewed. Of the cases, 28 were with benign tumors treated by surgery alone, and 5 were malignant tumors treated by surgery plus postoperative radical radiotherapy.</p><p><b>RESULTS</b>The parapharyngeal neoplasms in all cases were completely resected via styloid diaphragm approach. The postoperative follow-up ranged from 13 months to 7 years (median = 4.6 years). No tumor recurrence was found in 30 cases, but 3 cases experienced tumor recurrence, including 1 chondrosarcoma (3 years after surgery and chemoradiotherapy), 1 chordoma and 1 adenoid cystic carcinoma (5 years after surgery and radiotherapy). Severe postoperative complications were not observed, but 2 cases showed mild mouth askew and fully recovered after 3 months, and 1 case was complicated with hoarseness and cough symptoms that disappeared after heteropathy.</p><p><b>CONCLUSION</b>Resection of parapharyngeal neoplasms via styloid diaphragm approach is an ideal surgical technique, with well-exposed surgical field, less tissue injury, and less postoperative complication.</p>


Subject(s)
Humans , Carcinoma, Adenoid Cystic , General Surgery , Chondrosarcoma , General Surgery , Chordoma , General Surgery , Cough , Diaphragm , Mouth , Neoplasm Recurrence, Local , General Surgery , Otorhinolaryngologic Surgical Procedures , Methods , Pharyngeal Neoplasms , General Surgery , Pharynx , General Surgery , Postoperative Period
5.
Journal of Zhejiang University. Medical sciences ; (6): 550-555, 2013.
Article in Chinese | WPRIM | ID: wpr-252591

ABSTRACT

<p><b>OBJECTIVE</b>To investigate the effect of renal sympathetic denervation on left ventricular hypertrophy and inflammatory factors in spontaneously hypertensive rats.</p><p><b>METHODS</b>Thirty six spontaneously hypertensive rats (SHR) were divided into 3 groups with 12 animals in each group: SHR control group,operation group and sham operation group. Bilateral renal sympathectomy or sham operation were performed in operation and sham groups,respectively; another 12 WKY rats served as normal controls. The blood pressure and body weight were examined weekly. The animals were sacrificed at w1 and w6, rat hearts were collected and left ventricular mass index (LVMI) was calculated. The expression of TLR4,TNF-α and IL-6 in heart tissue were detected by immunohistochemistry and Western blot.</p><p><b>RESULTS</b>The systolic blood pressure [(201.67 ± 11.09) mmHg compared with (140.0 ± 10.86)mmHg,P<0.05],diastolic blood pressure [(144.50 ± 10.48)mmHg compared with (78.50 ± 7.32)mmHg,P<0.05], LVMI (2.44 ± 0.05 compared with 1.93 ± 0.05,P<0.05),the expression of TLR4 (0.298 ± 0.004 compared with 0.126 ± 0.004, P<0.05), NF-κB (0.249 ± 0.006 compared with 0.195 ± 0.005, P<0.05),TNF-α(0.323 ± 0.004 compared with 0.146 ± 0.004,P <0.05), IL-6 (0.283 ± 0.005 compared with 0.207 ± 0.006, P<0.05) in SHR control group were significantly higher than those in WKY group. Compared to sham operation group,the systolic blood pressure (157.30 ± 9.35 compared with 197.30 ± 11.5, P<0.05),diastolic blood pressure (112.50 ± 6.25 compared with 146.80 ± 7.6, P<0.05),LVMI (2.32 ± 0.04 compared with 2.57 ± 0.09, P<0.05, TLR4 (0.198 ± 0.006 compared with 0.317 ± 0.008, P<0.05), NF-κB (0.208 ± 0.006 compared with 0.332 ± 0.007, P<0.05), TNF-α(0.27 ± 0.009 compared with 0.375 ± 0.004,P<0.05), IL-6 (0.218 ± 0.004 compared with 0.376 ± 0.009, P<0.05) in operation group were all decreased at w1 after sympathectomy. Six weeks after the operation,there were no significant differences in systolic blood pressure (197.50 ± 12.13 compared with 208.83 ± 10.23,P>0.05) and diastolic blood pressure (150.33 ± 7.74 compared with 151.50 ± 8.22, P>0.05) between denervated and sham-operated SHRs; however,the LVMI (2.46 ± 0.07 compared with 2.81 ± 0.05,P<0.05) and the expression of TLR4(0.301 ± 0.009 compared with 0.567 ± 0.006, P<0.05), NF-κB (0.251 ± 0.004 compared with 0.476 ± 0.009,P<0.05),TNF-α(0.324 ± 0.005 compared with 0.535 ± 0.006, P<0.05,IL-6 (0.285 ± 0.009 compared with 0.549 ± 0.007, P<0.05) in operation group were still significantly lower than those in sham operation group.</p><p><b>CONCLUSION</b>Renal sympathetic denervation can significantly delay the progression of LVH in SHR, which may associated with lowering blood pressure and decreasing expression of TLR4, NF-κB,TNF-α, IL-6 in myocardial tissue.</p>


Subject(s)
Animals , Rats , Blood Pressure , Hypertrophy, Left Ventricular , General Surgery , Interleukin-6 , Metabolism , Kidney , Metabolism , NF-kappa B , Metabolism , Rats, Inbred SHR , Rats, Inbred WKY , Sympathectomy , Toll-Like Receptor 4 , Metabolism , Tumor Necrosis Factor-alpha , Metabolism
6.
Chinese Journal of Otorhinolaryngology Head and Neck Surgery ; (12): 66-68, 2011.
Article in Chinese | WPRIM | ID: wpr-277502

ABSTRACT

<p><b>OBJECTIVE</b>To explore the techniques, advantages and disadvantages, indications and cautions of a surgical approach for the resection of nasopharyngeal tumor.</p><p><b>METHODS</b>Ten cases with nasopharyngeal tumors were recruited in this study, of them, 3 cases with residual nasopharyngeal carcinoma after chemoradiotherapy, 2 cases with cavernous angioma, 2 cases with benign mixed tumor, 1 malignant mixed tumor, 1 adenoid cystic carcinoma, and 1 chordoma. All patients underwent endoscopic resection of posteroinferior quarter part of nasal septum, and then the removal of nasopharyngeal tumors through bilateral transnasal approach.</p><p><b>RESULTS</b>Total resection of the tumor was achieved for all cases without severe surgical complications. All cases with benign tumors, with following-up of 6-18 months, showed no recurrence. Of 6 cases with malignant tumors, with following-up of 12-48 months, 5 cases showed no recurrence, and 1 case was suspected to relapse one year postoperatively, but not with any lesion enlargement after another 6 month follow-up.</p><p><b>CONCLUSIONS</b>Posteroinferior quarter part of nasal septectomy is preferred for endoscopic resection of nasopharyngeal tumors because it can provide a panoramic view on nasopharyngeal cavity and tumors, thus, facilitating the removal of nasopharyngeal tumors.</p>


Subject(s)
Adult , Aged , Female , Humans , Male , Middle Aged , Young Adult , Endoscopy , Methods , Nasal Septum , General Surgery , Nasopharyngeal Neoplasms , General Surgery , Treatment Outcome
7.
Chinese Journal of Otorhinolaryngology Head and Neck Surgery ; (12): 84-88, 2008.
Article in Chinese | WPRIM | ID: wpr-248235

ABSTRACT

<p><b>OBJECTIVE</b>To analyze the surgical complications of endoscopic nasal-skull base surgery. The secondary objective was to propose the preliminary strategies for prevention and treatment of complications.</p><p><b>METHODS</b>One hundred and thirty two patients with nasal-skull base tumors undergoing endoscopic or endoscope-assisted surgery were included in this study. Surgical approaches included endoscopic endonasal transethmoidal approaches, endoscopic endonasal transseptal transsphenoidal approach, extended endoscopic endonasal transseptal transsphenoidal approach, endoscopic transmaxillary posttrial wall approach, extended endoscopic transmaxillary posttrial wall approach, endoscopic nasal lateral wall dissection, maxillary osteotomy approach and endoscopic transoropharyngeal approach. These approaches were selectively used to resect the tumors in the area of nasal-skull base.</p><p><b>RESULTS</b>The total resection of the tumors was obtained in 104 patients (104/132, 78.8%), with 29.5% (39/132) incidence of complications, including profuse bleeding, nerve injury, cerebrospinal fluid leakage, diabetes insipidus, electrolyte imbalance, hyperglycemia, and psychological disturbance. No catastrophic complications, sequelae and operative mortality encountered. Four months to 8 years' follow up (median 3.0 years) indicated that recurrence rate of the benign tumor was 9% (9/100) without died case, and 3-year and 5-year survival rates of the malignant tumor were 75.0% and 55.6%, respectively.</p><p><b>CONCLUSIONS</b>Strategies proved to be effective in reduction of the overall incidence of the complications, especially in minimizing the catastrophic complications and sequelae. The strategies were as follows: first, according to original site, extension and characteristics of the tumor, designing appropriate endoscopic approaches for the treatment of skull base tumor; second, recognizing reliable surgical access points and safe plane of the dissection; third, predicting surgical risks preoperatively and proposing the corresponding plan to avoid these risks; fourth, acquainted with the endoscopic skills and familiarized the skull base structures; lastly, ensuring the correct management of the interdisciplinary problems with close collaboration with the interdisciplinary medical personnels.</p>


Subject(s)
Adolescent , Adult , Aged , Child , Female , Humans , Male , Middle Aged , Young Adult , Endoscopy , Methods , Intraoperative Complications , Nose Neoplasms , General Surgery , Postoperative Complications , Skull Base Neoplasms , General Surgery , Treatment Outcome
8.
Chinese Journal of Otorhinolaryngology Head and Neck Surgery ; (12): 417-421, 2007.
Article in Chinese | WPRIM | ID: wpr-270808

ABSTRACT

<p><b>OBJECTIVE</b>To explore the optical surgical approaches for the resection of early and advanced stage of nasopharyngeal angiofibromas.</p><p><b>METHODS</b>Twenty two male patients aged 9 - 30 years (median 16 years) hospitalized in Xiangya Hospital from June 2003 to July 2006 with nasopharyngeal angiofibroma were recruited. Five operative approaches were selected according classification of juvenile nasopharyngeal angiofibroma described by Fisch. Six cases with stage I nasopharyngeal angiofibroma underwent endoscopic transnasal surgery. Six cases with stage II and 2 cases with stage III underwent endoscopic endonasal middle meatal transmaxillary-antrum approach. Three cases with stage III and 2 cases with stage IV underwent endoscopic endonasal middle and inferior meatal approach with extended transmaxillary-antrum resection. One case with stage IV underwent microscopic preauricula infratemporal fossa approaches combined with endoscopic endonasal middle and inferior meatal transantral approach. Two cases with stage IV underwent nasomaxillary osteotomy approach.</p><p><b>RESULTS</b>After surgery, CT scan or MR image showed that total removal of the tumor was achieved in 21 patients. One patient who received subtotal resection were performed by second endoscopic surgery and obtained total resection. No postoperative complications have been encountered in all treated patients. Nine months to 3 years follow up indicated that no cases recurred after surgery.</p><p><b>CONCLUSIONS</b>Appropriate surgical approach should be selected according to the clinical classification and whether the tumor has extended into whole nasal cavity, lateral fossa infratemporalis, intracranial or not. Such approaches might better facilitate the complete removal of nasopharyngeal angiofibromas and reduce the surgery-related injury.</p>


Subject(s)
Adolescent , Adult , Child , Humans , Male , Young Adult , Angiofibroma , Pathology , General Surgery , Endoscopy , Nasopharyngeal Neoplasms , Pathology , General Surgery , Neoplasm Staging
9.
Journal of Central South University(Medical Sciences) ; (12): 901-905, 2006.
Article in Chinese | WPRIM | ID: wpr-813576

ABSTRACT

OBJECTIVE@#To determine the diagnostic value and efficacy for risk stratification of myeloperoxidase (MPO) levels in patients with acute coronary syndrome (ACS).@*METHODS@#One hundred and sixty-two patients were enrolled in this study. All patients underwent coronary angiography. They were divided into 3 groups: ACS group (n=54), SAP group (n=54) and control group (n=54). Blood samples were taken from the artery before angiography in all patients and the concentrations of MPO, hsCRP and cTnI were measured. Each subject was asked details of history of hypertension, hyperlipidemia, diabetes and smoking habits. The efficacy of therapy, the cardiovascular events (myocardial infarction, the need for revascularization, or death) were recorded after 6 months of follow-up.@*RESULTS@#The plasma MPO level in ACS group (30.98 ng/mL) was significantly higher than those in the SAP group (14.67 ng/mL) and the control group(14.23 ng/mL)(P<0.01), and the plasma MPO levels in patients of the SAP group and the control group were not significantly different (P=0.74). There was no obvious correlation between the levels of plasma MPO and the serum levels of cTnI, hsCRP,the prevalence of the 4 major risk factors for CHD. Multivariate logistic regression analysis showed that plasma MPO level, free plasma glucose and sex were the significant variables. The risk for subsequent cardiovascular events was higher in the patients with elevated level of MPO.@*CONCLUSION@#Plasma MPO may be a new risk biomarker for ACS and may predict the incidence of subsequent cardiovascular events.


Subject(s)
Aged , Female , Humans , Male , Middle Aged , Acute Coronary Syndrome , Blood , Biomarkers , Blood , Case-Control Studies , Follow-Up Studies , Kaplan-Meier Estimate , Peroxidase , Blood
10.
Chinese Journal of Biotechnology ; (12): 45-50, 2002.
Article in Chinese | WPRIM | ID: wpr-231376

ABSTRACT

The nucleotide sequence and N-, C-terminal amino acid sequences of alpha,beta-subunit of glutaryl 7-ACA acylase C130 from Pseudomonas sp. 130 were determined. The alignment of the acylase C130 with the other acylases shows that it has high homology with the acylases from Pseudomonas sp. GK16 and C427, but low homology with the others. There is large difference in the N-terminal of alpha-subunit, while the N-terminal of beta-subunit has significant conservation.


Subject(s)
Amino Acid Sequence , Base Sequence , DNA, Bacterial , Genes, Bacterial , Molecular Sequence Data , Penicillin Amidase , Genetics , Pseudomonas , Genetics , Sequence Homology, Amino Acid , Sequence Homology, Nucleic Acid
11.
Chinese Journal of Biotechnology ; (12): 149-154, 2002.
Article in Chinese | WPRIM | ID: wpr-231359

ABSTRACT

A strain, MMR003, used for D-p-HPG production in industry was classified as Burkholderia pickettii by morphological observation and biochemical characterization. The gene encoding the D-hydantoinase enzyme was cloned, sequenced and expressed in Escherichia coli. The nucleotide sequence of the 5.0 kb insert of subclone pXZ-total was determined. One open reading frame of 1374 bp was found and predicted to encode a polypeptide consisting of 458 amino acids in size of 50 kD. The amino acid sequence alignment of D-hydantoinase from Burkholderia pickettii shows the 85% homologous with the corresponding enzyme from Agrobacterium radiobacter NRRL B11291. The D-hydantoinase gene (dha) harboured in the plasmid pXZPH2 in E. coli BL21(DE3) was highly expressed by IPTG induction. The D-hydantoinase activity for D, L-p-hydroxyphenylhydantion is 0.66 u/mL broth, which is 2-fold increase compared to the parent strain Burkholderia pickettii.


Subject(s)
Animals , Amidohydrolases , Genetics , Metabolism , Amino Acid Sequence , Burkholderia , Classification , Genetics , Cloning, Molecular , DNA Probes , Escherichia coli , Gene Expression , Molecular Sequence Data , Recombination, Genetic , Sequence Analysis, DNA , Sequence Homology, Amino Acid
12.
Chinese Journal of Biotechnology ; (12): 431-437, 2002.
Article in Chinese | WPRIM | ID: wpr-256190

ABSTRACT

A gene replacement/disruption system of Amycolatopsis mediterranei U32 was developed based on the established electroporation conditions as well as appropriate selective markers. Through two-step selection, ahbas gene in U32 was replaced by a promoterless alpha-amylase gene constructed on the plasmid pDK110 of E. coli. The first single-crossover and the second double-crossover frequencies were approximately 0.5%-0.7% and 2%, respectively. Denaturation of the plasmid pDK110 increased the integration frequency about 7-10 folds, while electric shock treatment of the single-crossover recombinants increased the frequency of second crossover recombination about 5 folds. Employing denatured DNA fragments containing an apramycin-resistance gene flanked with regions of the respective genes, One-step disruption of rifO and amrA genes of U32 was also achieved with an efficiency of 30-50 transformants per microgram of DNA.


Subject(s)
Actinomycetales , Genetics , DNA, Bacterial , Genetics , Drug Resistance, Microbial , Genetics , Genes, Bacterial , Genetics , Mutagenesis , Nebramycin , Pharmacology , Plasmids , Genetics , Recombination, Genetic
13.
Chinese Journal of Biotechnology ; (12): 662-666, 2002.
Article in Chinese | WPRIM | ID: wpr-256142

ABSTRACT

Streptoverticillum caespitosus ATCC27422 is a producing strain of mitomycin A for cancer therapy. Taking the advantage of the conserved sequences of genes flanking the oriC of high G + C Gram-positive bacteria, a 1.3 kb DNA fragment containing oriC and its flanking region was cloned by PCR. Nuleotide sequence comparisons revealed that the cloned fragment is more than 80% identical to the same region of S. coelicolor. There are 22 DnaA-boxes in the oriC region, and the conserved sequence of DnaA-box is TTGTCCACA. The plasmid containing the oriC of S. caespitosus was constructed (pMJ9), and it was able to transform the protoplast of Streptomyces lividans ZX7 at the frequency of 3.2 x 10(2) transformants/micrograms plasmid DNA. The colony and mycelia's morphology of the transformants are normal. The constructed plasmid can exist stable in the host as a low copy extra-chromosome replicon. The high rate of the homology and the cross genus replication initiation activity suggests close relationship between Streptomyces and Streptoverticillum in the evolution. While the maximum likelihood phylogenetic tree based upon the oriC of S. caespitosus and several Streptomyces spp. revealed that S. caespitosus differed extensively from the Streptomyces spp. This result supports the separation of Streptoverticillum from Streptomyces.


Subject(s)
Actinomycetales , Genetics , Base Sequence , Blotting, Southern , Cloning, Molecular , Conserved Sequence , Molecular Sequence Data , Plasmids , Replication Origin , Genetics , Streptomyces , Genetics , Transformation, Bacterial
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