1.Influence of exogenous putrescine and cadaverine on pro-inflammatory factors in the peripheral blood of rabbits.
Gui-cheng FAN ; Xin-zhou RONG ; Xue-min WANG ; Si-rong LIU ; Yue-ping ZHOU ; Qing-hui LI
Chinese Journal of Burns 2012;28(6):451-454
OBJECTIVETo explore the influence of exogenous putrescine and cadaverine on pro-inflammatory factors in the peripheral blood of rabbits.
METHODSForty ordinary adult New Zealand rabbits were divided into saline, necrotic tissue homogenate (NTH), putrescine, and cadaverine groups according to the random number table, with 10 rabbits in each group. Saline, NTH, 10 g/L putrescine, and 10 g/L cadaverine were respectively peritoneally injected into rabbits of corresponding group in the amount of 1 mL/kg. The blood sample in the volume of 2 mL was collected from the central artery of rabbit ears before injection and at 2, 6, 12, 24, 30, 36, 48, 60 hours post injection (PIH). Contents of TNF-α, IL-1, and IL-6 in the serum were determined with enzyme-linked immunosorbent assay. Data were processed with repeated measurement data analysis of variance and Spearman correlation analysis, and cubic model curve was applied in curve fitting for the contents of inflammatory factors.
RESULTS(1) The serum contents of TNF-α, IL-1, and IL-6 were increased in NTH, putrescine, and cadaverine groups in different degrees at most post injection time points. There was no significant change in the concentrations of the three pro-inflammatory factors in saline group, and they were significantly lower than those of the other three groups at most post injection time points (with F values from 3.49 to 13.58, P values all below 0.05). The serum contents of TNF-α, IL-1, and IL-6 in putrescine group began to increase at PIH 2, 6, and 6, which was similar to the trend of NTH group, but the changes were delayed compared with those of cadaverine group(all at PIH 2). The peak values of TNF-α, IL-1, and IL-6 in putrescine group were respectively (339 ± 36), (518 ± 44), and (265.9 ± 33.5) pg/mL, which were significantly lower than those of cadaverine group [ (476 ± 86), (539 ± 22), and (309.4 ± 27.1) pg/mL], with F values respectively 5.11, 1.90, and 5.56, P values all below 0.05. (2) The period of time in which contents of TNF-α, IL-1, and IL-6 began to increase (PIH 3-4) and the peaking time of the three pro-inflammatory cytokines (PIH 18-30) in putrescine group appeared later than those of cadaverine group (PIH 2 and 12-30). The duration of peaking time of the three pro-inflammatory cytokines in putrescine group was shorter than that of cadaverine group (PIH 18-30 vs. PIH 12-30). The increasing period and the duration of peaking time of TNF-α, IL-1, and IL-6 in putrescine group were close to those of NTH group (PIH 3-5 and 18-30). The correlation coefficient test analysis showed that the trends of changes in contents of three pro-inflammatory cytokines in putrescine group were significantly correlated with those of NTH group (r(TNF-α) = 0.933, P < 0.01; r(IL-1) = 0.967, P < 0.01; r(IL-6) = 0.950, P < 0.01). The obvious correlation between cadaverine group and NTH group was only found in the contents of IL-1 and IL-6 (r(IL-1) = 0.913, P < 0.01; r(IL-6) = 0.883, P < 0.05).
CONCLUSIONSBoth exogenous putrescine and cadaverine can cause inflammatory reaction in rabbits. The trend of the inflammatory reaction induced by putrescine was similar with that by NTH, suggesting that putrescine may play a leading role in the inflammatory reaction induced by necrotic tissue decomposition.
Animals ; Cadaverine ; adverse effects ; Inflammation ; blood ; Interleukin-1 ; blood ; Interleukin-6 ; blood ; Necrosis ; blood ; Putrescine ; adverse effects ; Rabbits ; Tumor Necrosis Factor-alpha ; blood
2.A new assembly of locking compression plate for treatment of femoral shaft comminuted fracture:a biomechanical study
Qianhuan GUI ; Min ZHAO ; Chunlin XIAO ; Jiangjun ZHOU ; Zhuanyi YU ; Qiuxin CHENG ; Jingxiang CHEN ; Meiqing FU ; Jun YANG ; Bona SI
Chinese Journal of Trauma 2018;34(5):426-431
Objective To compare the biomechanical characteristics of new assembly of locking compression plate (NALCP) and locking compression plate (LCP) in internal fixation of femoral shaft comminuted fractures.Methods The preparation of a femoral shaft wedge fracture model (AO type 32-C2.1),six pairs of (12) femoral specimens were collected and divided into two groups randomly,with six in each group.The Group A was made up of the new assembly of locking compression plate fixation model (NALCP),and Group B the locking compression plate fixation model (LCP).The biomechanical properties of steel plates in two groups were tested by axial loading and torsional loading tests.The relative maximum displacement of fracture blocks in two groups on the X,Y and Z axes (the coronal axis was set as X axis,through the medial and lateral femur;the transverse axis was set as Z axis,through the femoral intercondylar fossa,perpendicular to the X axis;the sagittal axis was set as Y axis,perpendicular to the X and Z axis),the maximum strain,and the average strain of the steel plate were recorded.Strain distribution nephogram was produced,and the axial loading fatigue test results of Group A were recorded.Results Axial loading test:the relative maximum displacement of fracture in Group A on X,Y and Z axis were smaller than those in Group B (P <0.05 or 0.01);the main strain of Group A was greater than that of Group B (P <0.01);there was no significant difference in the average strain between Group A and Group B (P > 0.05).Torsional loading test:The relative maximum displacement of fracture in Group A on X and Z axis was smaller than that of Group B (P < 0.01);there was no statistically significant difference between the two groups on the Y axis (P > 0.05);the main strain of plate in Group A was greater than that in Group B (P < 0.01);there was no statistically significant difference in the average strain between Group A and Group B (P > 0.05).There was no obvious difference in strain distribution between the two groups.In Group A,the fatigue test of axial cyclic loading was performed for 1 million times,and the NALCP was intact without deformation,loosening,or rupture.Conclusion NALCP can provide strong mechanical stability for comminuted femoral fracture.The design of bridge steel plate is reasonable,which can effectively avoid stress concentration,reduce the stress shielding of steel plate,and facilitate bone healing.
3.Comparison of the results of lymph node dissection via left versus right thoracotomy.
You-sheng MAO ; Jie HE ; Jing-si DONG ; Gui-yu CHENG ; Ke-lin SUN ; Xiang-yang LIU ; De-kang FANG ; Jian LI ; Yong-gang WANG
Chinese Journal of Oncology 2012;34(4):296-300
OBJECTIVEUp to now surgical treatment has been still the most effective treatment for esophageal cancer. However, postoperative lymph node recurrence is still a frequent event and affects long term survival considerably. The aim of this study is to compare the results of lymph node dissection via left vs. right thoracotomies and to verify whether there is any essential difference in lymphadenectomy between these two approaches.
METHODSFive hundred and fifty-nine cases with thoracic esophageal cancer were randomly selected from the database of esophageal cancer patients who underwent surgical treatment in our hospital between May 2005 and January 2011, including 282 cases through left thoracotomy and 277 cases through right thoracotomy. This series consisted of 449 males and 110 females with a mean age of 58.8 years (age range: 36 - 78 years). The pathological types were mainly squamous cell carcinoma (548 cases) and other rare types (11 cases). The data were analyzed and compared using Chi-square test. The P-value < 0.05 was considered as statistically significant. The actual 5-year survival rate was calculated based on the recent follow-up data of the patients who underwent surgery at least 5 years ago.
RESULTSThe average number of dissected lymph nodes was 23.4 via left versus 24.6 via right thoracotomies. The overall lymph node metastasis rate was 48.9% via left thoracotomy and 53.8% via right thoracotomy, and 34.8% vs. 50.5% in the chest (P < 0.001), 29.1% vs. 17.7% in the abdomen (P = 0.001). The pathologically confirmed lymph node metastasis rate was 45.9%, 44.0% and 34.9% in the upper, middle and lower segments of thoracic esophagus, respectively. The lymph node metastasis rates detected via left and right thoracotomy in the stage T1 cases were 14.7% (5/34) vs. 42.9% (12/28) (P < 0.001), and in the stage T2 cases were 35.4% (17/48) vs. 52.8% (28/53) (P = 0.007); in the station of para-thoracic esophagus were 9.6% vs. 13.4%, in the left upper mediastinum were 2.1% vs. 7.6%, and in the right upper mediastinum were 1.4% vs. 26.0%, respectively. The preliminary actual 5-year survival rate was 38.2% in the cases via left thoracotomy vs. 42.1% in those via right thoracotomy.
CONCLUSIONSThe results of this study demonstrate that lymph node dissection is more complete via right thoracotomy than via left thoracotomy, especially for the tracheoesophageal groove and para-recurrent laryngeal nerve nodes, which may eventually improve the survival of patients with esophageal cancer. Therefore, surgical treatment via right thoracotomy by Ivor-Lewis (two incisions) mode or Levis-Tanner (three incisions) mode with two-field or three-field complete lymph node dissection may become prevalent in the future.
Adult ; Aged ; Carcinoma, Squamous Cell ; pathology ; surgery ; Esophageal Neoplasms ; pathology ; surgery ; Esophagectomy ; Female ; Follow-Up Studies ; Humans ; Lymph Node Excision ; methods ; Lymphatic Metastasis ; Male ; Mediastinum ; pathology ; surgery ; Middle Aged ; Neoplasm Staging ; Survival Rate ; Thoracotomy ; methods
4.Changes of Serum Complement C1q in Patients with Multiple Myeloma.
Journal of Experimental Hematology 2022;30(2):506-510
OBJECTIVE:
To analyze the change of serum C1q in the course of multiple myeloma (MM) and its correlation with clinical characteristics.
METHODS:
A total of 138 newly diagnosed MM patients in Zhongnan Hospital of Wuhan University from June 2016 to December 2019 were selected as research objects, during the same period 50 age-matched anemia patients, 50 lymphoma patients, 50 leukemia patients, and 50 myelodysplastic syndrome (MDS) patients were selected as control groups. All the patients met WHO disease classification, and were definitely diagnosed by pathology or bone marrow smear/biopsy. The changes of C1q between MM patients and control group, as well as in different therapeutic responses of MM patients before and after treatment were compared, also the difference of clinical characteristics among MM patients with different C1q level, so as to analyze risk factors which led to C1q decline.
RESULTS:
The average value of C1q in MM patients was (128.18±51.24) mg/L, which was significantly lower than control group (P<0.01). The levels of white blood cell, platelet (PLT), hemoglobin (Hb), serum calcium, albumin, lactate dehydrogenase (LDH) in newly diagnosed high C1q group were significantly higher than those in low C1q group (P<0.05). Logistic analysis showed that the levels of PLT, Hb, albumin, and LDH in newly diagnosed high C1q group were higher than those in low C1q group (r=0.248, r=0.394, r=0.405, r=0.295). After treatment, the levels of C1q in MM patients with complete remission and very good partial remission were significantly higher than before treatment (P<0.05), while those with partial remission and stable disease also increased but not significantly (P>0.05).
CONCLUSION
The C1q level in MM patients is significantly lower than that in patients with other hematologic system diseases, and it increases with the remission of the disease after treatment.
Albumins
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Bone Marrow
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Complement C1q
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Humans
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Multiple Myeloma
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Risk Factors
5.Analysis of influencing factors for liver cancer by gender in Shunde region
Xin-feng ZHOU ; Zhi-mei WEI ; Cheng-yu ZHOU ; Xuan ZHONG ; Qing LIU ; Gui-yan LIU ; Yan-hui GAO ; Xin-fa YU ; Si-dong CHEN ; Li. LIU
Chinese Journal of Disease Control & Prevention 2019;23(2):129-133,139
Objective To investigate the influencing factors for liver cancer by gender in Shunde region, and to explore the potential interactions among influencing factors for liver cancer in males. Methods The relative excess risk of interaction (RERI) and other indices were used to evaluate the pair-wise interaction, and the classification and regression tree (CART) model was applied to explore the potential multi-factors interaction. Results This study included 1 037 male cases and 1 069 controls, together with 166 female cases and 185 controls. Chronic hepatitis B virus infection (CHB) and family history of liver cancer were significantly associated with increased risk of liver cancer both in males and females (both P<0.001). In males, positive additive interactions were observed between CHB and smoking or alcohol drinking, as well as between smoking and drinking. The RERI for CHB and smoking was 121.90(95% CI:52.85%-190.95%). Negative additive interactions were observed between exercise and CHB or smoking. Further, the CART analysis suggested that the CHB males who smoked and drank alcohol had the highest risk of liver cancer. Conclusions CHB and family history of liver cancer are important risk factors for liver cancer in both males and females. CHB, smoking, and alcohol drinking synergistically promote the incidence of liver cancer for males. Exercise can antagonize the hepatocarcinogenic effect of CHB and smoking.
6.Cardiopulmonary exercise testing in the evaluation of high risk patients with lung cancer.
You-Sheng MAO ; Jie HE ; Shao-Ping YAN ; Jing-Si DONG ; Gui-Yu CHENG ; Ke-Lin SUN ; Xiang-Yang LIU ; De-Kang FANG ; Jian LI ; Yong-Gang WANG ; Jin-Feng HUANG
Chinese Medical Journal 2010;123(21):3089-3094
BACKGROUNDIt is still unclear whether pulmonary function tests (PFTs) are sufficient for predicting perioperative risk, and whether all patients or only a subset of them need a cardiopulmonary exercise test (CPET) for further assessment. Thus, this study was designed to evaluate the CPET and compare the results of CPET and conventional PFTs to identify which parameters are more reliable and valuable in predicting perioperative risks for high risk patients with lung cancer.
METHODSFrom January 2005 to August 2008, 297 consecutive lung cancer patients underwent conventional PFTs (spirometry + single-breath carbon monoxide diffusing capacity of the lungs (DLCOsb) for diffusion capacity) and CPET preoperatively. The correlation of postoperative cardiopulmonary complications with the parameters of PFT and CPET was retrospectively analyzed using the chi-square test, independent sample t test and binary Logistic regression analysis.
RESULTSOf the 297 patients, 78 did not receive operation due to advanced disease stage or poor cardiopulmonary function. The remaining 219 underwent different modes of operations. Twenty-one cases were excluded from this study due to exploration alone (15 cases) and operation-related complications (6 cases). Thus, 198 cases were eligible for evaluation. Fifty of the 198 patients (25.2%) had postoperative cardiopulmonary complications. Three patients (1.5%) died of complications within 30 postoperative days. The patients were stratified into groups based on VO(2)max/pred (≥ 70.0%, < 70.0%); VO(2)max×kg(-1)×min(-1) (≥ 20.0 ml, 15.0 - 19.9 ml, < 15.0 ml) and FEV1 (≥ 2.0 L, 1.2 - 1.99 L, < 1.2 L), respectively. The rate of postoperative cardiopulmonary complications was significantly higher in the group with VO(2)max/pred< 70.0% or VO(2)max×kg(-1)×min(-1) < 15.0 ml or FEV1 < 1.2 L than that in the group with VO(2)max/pred ≥ 70.0% or VO(2)max×kg(-1)×min(-1) ≥ 15.0 ml or FEV1 ≥ 1.2 L, respectively. Logistic regression analysis revealed that postoperative cardiopulmonary complications were significantly correlated with age, comorbidities, and poor PFT and CPET results.
CONCLUSIONSFEV1 in spirometry, VO(2)max×kg(-1)×min(-1) and VO(2)max/pred in cardiopulmonary exercise tests can all be used to stratify the patients' cardiopulmonary function status and to predict the risk of postoperative cardiopulmonary complications for the high risk patients with lung cancer. FEV1 and VO(2)max×kg(-1)×min(-1) are better than VO(2)max/pred in predicting perioperative risk. If available, cardiopulmonary exercise testing is strongly suggested for high-risk lung cancer patients in addition to conventional pulmonary function tests, and both should be combined to assess cardiopulmonary function status.
Adult ; Aged ; Aged, 80 and over ; Exercise Test ; methods ; Female ; Humans ; Lung Neoplasms ; physiopathology ; Male ; Middle Aged ; Respiratory Function Tests ; methods
7.Surgical treatment of sternal tumors: resection of the tumors and reconstruction of the chest wall defects.
Da-wei WANG ; Jie HE ; Kai LIANG ; Xiao-lei ZHU ; Jing-si DONG ; Gui-yu CHENG ; Ke-lin SUN ; Xiang-yang LIU ; Wen-dong LEI ; Jian LI
Chinese Journal of Oncology 2012;34(7):514-516
OBJECTIVETo investigate the efficacy of surgical treatment of sternal tumors and repairing methods of the chest wall defects.
METHODSFifteen patients with sternal tumors were diagnosed and underwent resection of the sternal tumors according to the en-bolck principle and repair of the chest wall defects using various materials from January 1968 to December 2010 in our hospital.
RESULTSOf 6 patients with sternal manubrim tumors, one patient had reconstruction only with steel wire, other 5 patients healed completely after repair with soft materials. Of 7 patients with sternal body tumors, one patient recovered quickly without reconstruction because he had only partial resection; four patients had chest wall repair with soft materials, but they breathed hardly; and two patients had chest wall reconstruction with rigid materials. One patient had ventilatory support, another patient recovered quickly. Ventilatory support was needed in two patients treated by subtotal sternectomy because they had chest wall repair with soft materials.
CONCLUSIONSIn surgical treatment of sternal tumors by manubrim sternetomy, the chest wall defects can be constructed with soft materials. After resection of sternal body tumors and subtotal sternectomy, the thoracic wall defects need to be reconstructed with rigid materials.
Adenocarcinoma ; secondary ; surgery ; Adult ; Aged ; Bone Neoplasms ; pathology ; surgery ; Chondrosarcoma ; pathology ; surgery ; Female ; Humans ; Male ; Middle Aged ; Reconstructive Surgical Procedures ; methods ; Sternum ; pathology ; surgery ; Thoracic Surgical Procedures ; methods ; Thoracic Wall ; pathology ; surgery
8.Preliminary molecular epidemiology of the Staphylococcus aureus in lower respiratory tract infections: a multicenter study in China.
De-Zhi LI ; Yu-Sheng CHEN ; Jing-Ping YANG ; Wei ZHANG ; Cheng-Ping HU ; Jia-Shu LI ; Lan MU ; Ying-Hui HU ; Rong GENG ; Ke HU ; Shao-Xi CAI ; Huan-Ying WAN ; Qiu-Yue WANG ; Li-Ping WEI ; Juan DU ; Qin YU ; Xiao-Ning ZHONG ; Rui-Qin WANG ; Jian-Jun MA ; Gui-Zhen TIAN ; Si-Qin WANG ; Zhan-Cheng GAO
Chinese Medical Journal 2011;124(5):687-692
BACKGROUNDStaphylococcus aureus (S. aureus) remains as an important microbial pathogen resulting in community and nosocomial acquired infections with significant morbidity and mortality. Few reports for S. aureus in lower respiratory tract infections (LRTIs) have been documented. The aim of this study was to explore the molecular epidemiology of S. aureus in LRTIs in China.
METHODSA multicenter study of the molecular epidemiology of S. aureus in LRTIs was conducted in 21 hospitals in Beijing, Shanghai and twelve other provinces from November 2007 to February 2009. All the collected S. aureus strains were classified as minimum inhibitory concentration (MIC), mecA gene, virulence genes Panton-Valentine Leukocidin (PVL) and γ-hemolysin (hlg), staphylococcal cassette chromosome mec (SCCmec) type, agr type, and Multilocus Sequence Typing (MLST).
RESULTSTotally, nine methicillin-sensitive S. aureus (MSSA) and 29 methicillin-resistant S. aureus (MRSA) strains were isolated after culture from a total of 2829 sputums or bronchoalveolar lavages. The majority of MRSA strains (22/29) had a MIC value of ≥ 512 µg/ml for cefoxitin. The mecA gene acting as the conservative gene was carried by all MRSA strains. PVL genes were detected in only one S. aureus strain (2.63%, 1/38). The hlg gene was detected in almost the all S. aureus (100% in MSSA and 96.56% in MRSA strains). About 75.86% of MRSA strains carried SCCmec III. Agr type 1 was predominant (78.95%) among the identified three agr types (agr types 1, 2, and 3). Totally, ten sequence type (ST) of S. aureus strains were detected. A new sequence type (ST1445) was found besides confirming ST239 as the major sequence type (60.53%). A dendrogram generated from our own MLST database showed all the bootstrap values ≤ 50%.
CONCLUSIONOur preliminary epidemiology data show SCCmec III, ST239 and agr type 1 of S. aureus as the predominant strains in LRTIs in Mainland of China.
Alleles ; Anti-Bacterial Agents ; therapeutic use ; China ; epidemiology ; Drug Resistance, Bacterial ; genetics ; Humans ; Microbial Sensitivity Tests ; Prospective Studies ; Respiratory Tract Infections ; epidemiology ; Staphylococcal Infections ; epidemiology ; Staphylococcus aureus ; drug effects ; pathogenicity
9.Determination and correlation analysis of contents of putrescine, cadaverine, and histamine in necrotic tissue, blood, and urine of patients with diabetic foot.
Si-rong LIU ; Xin-zhou RONG ; Gui-cheng FAN ; Qing-hui LI ; Ya-ming WEI
Chinese Journal of Burns 2013;29(6):526-530
OBJECTIVETo determine and perform a correlation analysis of the contents of putrescine, cadaverine, and histamine in necrotic tissue, blood, and urine of patients with diabetic foot (DF).
METHODSTen patients with severe wet necrotizing DF hospitalized from January 2011 to January 2012 were assigned as group DF, and 10 orthopedic patients with scar but without diabetes or skin ulcer hospitalized in the same period were assigned as control group. Samples of necrotic tissue from feet of patients in group DF and normal tissue from extremities of patients in control group, and samples of blood and 24-hour urine of patients in both groups were collected, and the amount of each sample was 10 mL. Contents of putrescine, cadaverine, and histamine were determined with high performance liquid chromatography-mass spectrometry. The data got from the determination of blood and urine were processed with t test, and those from necrotic or normal tissue with Wilcoxon rank sum test. The correlation of contents of polyamines between necrotic tissue and blood, blood and urine were processed with simple linear regression analysis.
RESULTS(1) Contents of putrescine, cadaverine, and histamine in the necrotic tissue of group DF were (186.1 ± 26.8), (78.553 ± 12.441), (33 ± 10) mg/kg, which were significantly higher than those in normal tissue of control group [(2.2 ± 1.2), (1.168 ± 0.014), 0 mg/kg, with Z values respectively -3.780, -3.781, -4.038, P values all below 0.01]. The content of putrescine in necrotic tissue of group DF was significantly higher than those of cadaverine and histamine (with Z values respectively -3.780, -3.630, P values all below 0.01). (2) Contents of putrescine, cadaverine, and histamine in the blood of group DF were (0.075 ± 0.013), (0.022 ± 0.003), (0.052 ± 0.014) mg/L, and they were significantly higher than those in the blood of control group [(0.014 ± 0.009), (0.013 ± 0.003), (0.016 ± 0.008) mg/L, with t values respectively 6.591, 2.207, 3.568, P < 0.05 or P<0.01]. The content of putrescine in the blood of group DF was significantly higher than those of cadaverine and histamine (with t values respectively 13.204, 3.096, P values all below 0.01). (3) Contents of putrescine, cadaverine, and histamine in the urine of group DF were (0.735 ± 0.088), (0.450 ± 0.012), (0.1623 ± 0.0091) mg/L, and only the contents of putrescine and cadaverine were significantly higher than those in the urine of control group [(0.050 ± 0.014), (0.035 ± 0.007) mg/L, with t values respectively 3.270, 4.705, P<0.05 or P<0.01]. The content of putrescine in the urine of group DF was significantly higher than that of cadaverine (t = 6.686, P < 0.01). (4) There were significant and positive correlations in contents of putrescine, cadaverine, and histamine between necrotic tissue and blood in patients of group DF (with r values respectively 0.981, 0.994, 0.821, P values all below 0.01). There were no significant correlations in contents of putrescine, cadaverine, and histamine between blood and urine in patients of group DF (with r values respectively 0.150, 0.239, 0.177, P values all above 0.05).
CONCLUSIONSPutrescine, cadaverine, and histamine exist in the necrotic tissue of patients with DF in high concentrations, among which putrescine predominates. These polyamines can be absorbed into the blood through wound and excreted through the urine.
Adult ; Aged ; Cadaverine ; blood ; metabolism ; urine ; Case-Control Studies ; Diabetic Foot ; blood ; metabolism ; urine ; Female ; Histamine ; blood ; metabolism ; urine ; Humans ; Male ; Middle Aged ; Necrosis ; Putrescine ; blood ; metabolism ; urine
10.Drug-resistant genes carried by Acinetobacter baumanii isolated from patients with lower respiratory tract infection.
Ning DAI ; De-zhi LI ; Ji-chao CHEN ; Yu-sheng CHEN ; Rong GENG ; Ying-hui HU ; Jing-ping YANG ; Juan DU ; Cheng-ping HU ; Wei ZHANG ; Jia-shu LI ; Qin YU ; Huan-ying WAN ; Lan MU ; Xiao-ning ZHONG ; Li-ping WEI ; Jian-jun MA ; Qiu-yue WANG ; Ke HU ; Gui-zhen TIAN ; Shao-xi CAI ; Rui-qin WANG ; Bei HE ; Si-qin WANG ; Zhan-wei WANG ; Su-rui ZHAO ; Zhan-cheng GAO
Chinese Medical Journal 2010;123(18):2571-2575
BACKGROUNDAcinetobacter baumanii (A. baumanii ) remains an important microbial pathogen resulting in nosocomial acquired infections with significant morbidity and mortality. The mechanism by which nosocomial bacteria, like A. baumanii, attain multidrug resistance to antibiotics is of considerable interest. The aim in this study was to investigate the spread status of antibiotic resistance genes, such as multiple β-lactamase genes and aminoglycoside-modifying enzyme genes, from A. baumanii strains isolated from patients with lower respiratory tract infections (LRTIs).
METHODSTwo thousand six hundred and ninety-eight sputum or the bronchoalveolar lavage samples from inpatients with LRTIs were collected in 21 hospitals in the mainland of China from November 2007 to February 2009. All samples were routinely inoculated. The isolated bacterial strains and their susceptibility were analyzed via VITEK-2 expert system. Several kinds of antibiotic resistant genes were further differentiated via polymerase chain reaction and sequencing methods.
RESULTSTotally, 39 A. baumanii strains were isolated from 2698 sputum or bronchoalveolar lavage samples. There was not only a high resistant rate of the isolated A. baumanii strains to ampicillin and first- and second-generation cephalosporins (94.87%, 100% and 97.44%, respectively), but also to the third-generation cephalosporins (ceftriaxone at 92.31%, ceftazidine at 51.28%) and imipenem (43.59%) as well. The lowest antibiotic resistance rate of 20.51% was found to amikacin. The OXA-23 gene was identified in 17 strains of A. baumanii, and the AmpC gene in 23 strains. The TEM-1 gene was carried in 15 strains. PER-1 and SHV-2 genes were detected in two different strains. Aminoglycoside-modifying enzyme gene aac-3-Ia was found in 23 strains, and the aac-6'-Ib gene in 19 strains. aac-3-Ia and aac-6'-Ib genes hibernated in three A. baumanii strains that showed no drug-resistant phenotype.
CONCLUSIONSA. baumanii can carry multiple drug-resistant genes at the same time and result in multi-drug resistance. Aminoglycoside-modifying enzyme genes could be hibernating in aminoglycoside sensitive strains without expressing their phenotype.
Acinetobacter ; genetics ; metabolism ; pathogenicity ; Acinetobacter Infections ; microbiology ; Bacterial Proteins ; genetics ; Bronchoalveolar Lavage Fluid ; microbiology ; Drug Resistance, Multiple, Bacterial ; genetics ; Humans ; Microbial Sensitivity Tests ; Polymerase Chain Reaction ; Respiratory Tract Infections ; microbiology ; Sputum ; microbiology