1.The effect of wza gene deletion in Klebsiella pneumoniae on capsule formation and bacteriophage sensitivity
Zheng FAN ; Hongbo LIU ; Yuchen CHEN ; Xiaohu CUI ; Zhoufei LI ; Tongtong FU ; Jing YUAN
Chinese Journal of Preventive Medicine 2024;58(7):992-997
Objective:To investigate the effects of wza gene deletion in Klebsiella pneumoniae on capsule formation ability and bacteriophage sensitivity. Methods:The wza deletion mutant strain was constructed through a temperature-sensitive plasmid-mediated homologous recombination. The growth curves of W14 and Δ wza were detected by measuring the optical density OD 600. In order to analyze the effect of gene wza on bacterial capsule formation, wild-type strain W14 and Δ wza mutant strain were detected by transmission electron microscope, and their capsule contents were measured by quantifying the uronic acid contents. The plaque assay was used to detect bacterial sensitivity to bacteriophage in wild-type strain W14 and Δ wza mutant strain. The t test was used to compare whether there were differences in the contents of uronic acid in the capsules of wild-type strain W14 and Δ wza mutant strain. Results:The PCR results revealed that the Δ wza mutant strain was successfully constructed. Compared with wild-type strain W14, the growth curves of Δ wza on the solid plates demonstrated a slightly slower growth. However, no difference in growth was observed among wild-type strain W14 and Δ wza mutant strains in LB broth. The transmission electron microscope results showed that wza gene deletion resulted in the loss of capsule in bacteria. The uronic acid content assay suggested that the capsule content was significantly decreased in Δ wza mutant strain (45.963±2.795) μg/ml compared with wild-type strain W14 (138.800±5.201) μg/ml. There was a statistical difference between the two groups ( t=27.233, P<0.001). The plaque assay indicated that bacteria lost its sensitivity to bacteriophage when gene wza was deleted. Conclusion:Deletion of the wza gene impairs bacterial capsule formation ability and can affect bacterial sensitivity to bacteriophage phiW14.
2.Expression, purification and functional validation of phage depolymerase from hypervirulent Klebsiella pneumoniae serotype K1
Zheng FAN ; Yuchen CHEN ; Hongbo LIU ; Xiaohu CUI ; Zhoufei LI ; Tongtong FU ; Jing YUAN
Chinese Journal of Preventive Medicine 2024;58(9):1348-1353
Objective:To express and purify the phage depolymerase from hypervirulent Klebsiella pneumoniae (hv Kp) serotype K1 and validate its function. Methods:Phage that infected serotype K1-type hv Kp was isolated from hospital sewage. The biology and morphology of the phage were determined by plaque assay and transmission electron microscopy. The whole genome of the phage was sequenced by the Illumina HiSeq 2500 platform. The presence of depolymerase was determined by observing the plaque halo. Bioinformatic analysis and prokaryotic protein expression system were further used to predict and identify phage depolymerase. The depolymerase gene fragment was obtained by PCR and cloned into the pET28a expression vector, and the expression and purification of the depolymerase were completed in strain BL21. The depolymerase activities on the capsular polysaccharide of serotype K1-type hv Kp clinical isolates were detected by plaque assay and low-speed centrifugation assay. Results:A lytic phage (phiA2) that infected serotype K1-type hv Kp clinical isolate was isolated from hospital sewage. It was typical of the Caudovirales order and Autographiviridae family, and its whole genome was 43 526 bp in length and contained 51 coding domain sequences. The phage phiA2-derived depolymerase phiA2-dep was predicted, expressed and purified. The plaque assay and low-speed centrifugation assay indicated that the depolymerase phiA2-dep had good lytic activity on the capsular polysaccharide of serotype K1-type hv Kp clinical isolates. Conclusion:Depolymerase phiA2-dep can specifically degrade the capsular polysaccharide of serotype K1-type hv Kp, which has potential application value in treating bacterial infection.
3.The effect of wza gene deletion in Klebsiella pneumoniae on capsule formation and bacteriophage sensitivity
Zheng FAN ; Hongbo LIU ; Yuchen CHEN ; Xiaohu CUI ; Zhoufei LI ; Tongtong FU ; Jing YUAN
Chinese Journal of Preventive Medicine 2024;58(7):992-997
Objective:To investigate the effects of wza gene deletion in Klebsiella pneumoniae on capsule formation ability and bacteriophage sensitivity. Methods:The wza deletion mutant strain was constructed through a temperature-sensitive plasmid-mediated homologous recombination. The growth curves of W14 and Δ wza were detected by measuring the optical density OD 600. In order to analyze the effect of gene wza on bacterial capsule formation, wild-type strain W14 and Δ wza mutant strain were detected by transmission electron microscope, and their capsule contents were measured by quantifying the uronic acid contents. The plaque assay was used to detect bacterial sensitivity to bacteriophage in wild-type strain W14 and Δ wza mutant strain. The t test was used to compare whether there were differences in the contents of uronic acid in the capsules of wild-type strain W14 and Δ wza mutant strain. Results:The PCR results revealed that the Δ wza mutant strain was successfully constructed. Compared with wild-type strain W14, the growth curves of Δ wza on the solid plates demonstrated a slightly slower growth. However, no difference in growth was observed among wild-type strain W14 and Δ wza mutant strains in LB broth. The transmission electron microscope results showed that wza gene deletion resulted in the loss of capsule in bacteria. The uronic acid content assay suggested that the capsule content was significantly decreased in Δ wza mutant strain (45.963±2.795) μg/ml compared with wild-type strain W14 (138.800±5.201) μg/ml. There was a statistical difference between the two groups ( t=27.233, P<0.001). The plaque assay indicated that bacteria lost its sensitivity to bacteriophage when gene wza was deleted. Conclusion:Deletion of the wza gene impairs bacterial capsule formation ability and can affect bacterial sensitivity to bacteriophage phiW14.
4.Expression, purification and functional validation of phage depolymerase from hypervirulent Klebsiella pneumoniae serotype K1
Zheng FAN ; Yuchen CHEN ; Hongbo LIU ; Xiaohu CUI ; Zhoufei LI ; Tongtong FU ; Jing YUAN
Chinese Journal of Preventive Medicine 2024;58(9):1348-1353
Objective:To express and purify the phage depolymerase from hypervirulent Klebsiella pneumoniae (hv Kp) serotype K1 and validate its function. Methods:Phage that infected serotype K1-type hv Kp was isolated from hospital sewage. The biology and morphology of the phage were determined by plaque assay and transmission electron microscopy. The whole genome of the phage was sequenced by the Illumina HiSeq 2500 platform. The presence of depolymerase was determined by observing the plaque halo. Bioinformatic analysis and prokaryotic protein expression system were further used to predict and identify phage depolymerase. The depolymerase gene fragment was obtained by PCR and cloned into the pET28a expression vector, and the expression and purification of the depolymerase were completed in strain BL21. The depolymerase activities on the capsular polysaccharide of serotype K1-type hv Kp clinical isolates were detected by plaque assay and low-speed centrifugation assay. Results:A lytic phage (phiA2) that infected serotype K1-type hv Kp clinical isolate was isolated from hospital sewage. It was typical of the Caudovirales order and Autographiviridae family, and its whole genome was 43 526 bp in length and contained 51 coding domain sequences. The phage phiA2-derived depolymerase phiA2-dep was predicted, expressed and purified. The plaque assay and low-speed centrifugation assay indicated that the depolymerase phiA2-dep had good lytic activity on the capsular polysaccharide of serotype K1-type hv Kp clinical isolates. Conclusion:Depolymerase phiA2-dep can specifically degrade the capsular polysaccharide of serotype K1-type hv Kp, which has potential application value in treating bacterial infection.
5.A positive feedback loop of heparanase/ syndecan1erve growth factor regulates cancer pain progression
Xiaohu SU ; Bingwu WANG ; Zhaoyun ZHOU ; Zixian LI ; Song TONG ; Simin CHEN ; Nan ZHANG ; Su LIU ; Maoyin ZHANG
The Korean Journal of Pain 2023;36(1):60-71
Background:
The purpose of this research was to assess the role of heparanase (HPSE)/syndecan1 (SDC1)erve growth factor (NGF) on cancer pain from melanoma.
Methods:
The influence of HPSE on the biological function of melanoma cells and cancer pain in a mouse model was evaluated. Immunohistochemical staining was used to analyze HPSE and SDC1. HPSE, NGF, and SDC1 were detected using western blot. Inflammatory factors were detected using ELISA assay.
Results:
HPSE promoted melanoma cell viability, proliferation, migration, invasion, and tumor growth, as well as cancer pain, while SST0001 treatment reversed the promoting effect of HPSE. HPSE up-regulated NGF, and NGF feedback promoted HPSE. High expression of NGF reversed the inhibitory effect of HPSE down-regulation on melanoma cell phenotype deterioration, including cell viability, proliferation, migration, and invasion. SST0001 down-regulated SDC1 expression. SDC1 reversed the inhibitory effect of SST0001 on cancer pain.
Conclusions
The results showed that HPSE promoted melanoma development and cancer pain by interacting with NGF/SDC1. It provides new insights to better understand the role of HPSE in melanoma and also provides a new direction for cancer pain treatment.
6.Feasibility and safety of bipolar-plasmakinetic transurethral enucleation and resection of the prostate in day surgery mode.
Zhihui ZOU ; Ligang ZHANG ; Keke CAI ; Yongtao HU ; Shuchen LIU ; Jia CHEN ; Qintao GE ; Xiaohu ZHAO ; Zongyao HAO ; Chaozhao LIANG
Journal of Zhejiang University. Medical sciences 2023;52(2):148-155
OBJECTIVES:
To evaluate the feasibility and safety of bipolar-plasmakinetic transurethral enucleation and resection of the prostate (B-TUERP) in day surgery.
METHODS:
From January 2021 to August 2022, 34 patients with benign prostatic hyperplasia (BPH) underwent B-TUERP in day surgery in the First Affiliated Hospital of Anhui Medical University. Patients completed the screening and anesthesia evaluation before admission and received the standard surgery which implements "anatomical enucleation of the prostate" and "absolute bleeding control" on the same day of admission, and by the same doctor. Bladder irrigation was stopped, catheter was removed and the discharge evaluation was performed on the first day after operation. The baseline data, perioperative conditions, time of recovery, treatment outcomes, hospitalization costs, and postoperative complications were analyzed.
RESULTS:
All operations were successfully conducted. The average age of the patients was (62.2±7.8) years, average prostate volume was (50.2±29.3) mL. The average operation time was (36.5±19.1) min, the average hemoglobin and blood sodium were decreased by (16.2±7.1) g/L and (2.2±2.0) mmol/L, respectively. The average postoperative length of hospital stay, and total length of hospital stay were (17.7±2.2) and (20.8±2.1) h, respectively, and the average hospitalization cost was (13 558±2320) CNY. All patients were discharged on the day after surgery except for one patient who was transferred to a general ward. Three patients received indwelling catheterization after catheter removal. The 3-month follow-up results showed a substantial improvement in the International Prostate Symptom Score, quality of life score and maximum urinary flow rate (all P<0.01). Three patients experienced temporary urinary incontinence, 1 patient experienced urinary tract infection, 4 patients were diagnosed with urethral stricture and 2 patients experienced bladder neck contracture. No complications above Clavien grade Ⅱ occurred.
CONCLUSIONS
The preliminary results showed that B-TUERP ambulatory surgery is a safe, feasible, economical and effective treatment for appropriately selected patients with BPH.
Male
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Humans
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Middle Aged
;
Aged
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Prostate/surgery*
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Prostatic Hyperplasia/surgery*
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Ambulatory Surgical Procedures
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Quality of Life
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Feasibility Studies
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Retrospective Studies
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Treatment Outcome
7.Macular morphology and vascular parameters changes following micro-invasive vitrectomy in patients with severe non-proliferative diabetic retinopathy
Wenbin ZHENG ; Ying LIN ; Kunbei LAI ; Shida CHEN ; Xiaohu DING ; Bingqian LIU ; Sainan XIAO ; Jizhu LI ; Yuan MA ; Ziye CHEN ; Xiaoling LIANG ; Lin LYU ; Tao LI
Chinese Journal of Ocular Fundus Diseases 2022;38(1):34-39
Objective:To observe the changes of macular morphology and blood flow after minimally invasive vitrectomy (PPV) in patients with severe non-proliferative diabetic retinopathy (sNPDR).Methods:A prospective clinical study. From January 2020 to April 2021, 17 consecutive sNPDR patients with 17 eyes who were diagnosed and received PPV treatment at the Zhongshan Ophthalmic Center of Sun Yat-sen University were included in the study. There were 12 males with 12 eyes and 5 females with 5 eyes; the average age was 55 years old; the average duration of diabetes was 11 years; the average glycosylated hemoglobin was 7.9%. Before the operation and 1, 3, and 6 months after the operation, all the affected eyes underwent best corrected visual acuity (BCVA), standard 7-field fundus color photography, and optical coherence tomography angiography (OCTA). An OCTA instrument was used to scan the macular area of the affected eye with in the range of 3 mm×3 mm to measure the central subfoveal thickness (CST), the thickness of the ganglion cell complex (GCC) in the macular area, the thickness of the retinal nerve fiber layer (RNFL), and the superficial capillary plexus (SCP) vessel density and perfusion density in the macular area, macular avascular zone (FAZ) area, a-circularity index (AI). Before the operation and 6 months after the operation, the least significant difference test was used for the pairwise comparison.Results:Before the operation, 1, 3, and 6 months after the operation, the FAZ area of the macular area were 0.34±0.14, 0.35±0.10, 0.37±0.10, 0.36±0.13 mm 2, respectively; AI were 0.52±0.13, 0.54±0.11, 0.57±0.10, 0.60±0.11; CST was 282.6±66.7, 290.4±70.9, 287.2±67.5, 273.2± 49.6 μm; GCC thickness were 77.1±15.5, 74.3±13.9, 72.6±16.2, 78.5±18.3 μm; the thickness of RNFL was 97.9±13.8, 101.3±14.6, 97.7±12.0, 96.1±11.4 μm, respectively. The overall blood flow density of SCP in the macula were (16.79±1.43)%, (16.71±1.82)%, (17.30±2.25)%, (17.35±1.22)%; the overall perfusion density were 0.32±0.02, 0.32±0.03, 0.33±0.03, 0.33±0.02, respectively. After the operation, the CST increased first and then decreased; the thickness of RNFL increased 1 month after the operation, and then gradually decreased. Comparison of the parameters before and 6 months after the operation showed that the AI improved, and the difference was statistically significant ( P=0.049); the difference in FAZ area and the thickness of CST, GCC, and RNFL was not statistically significant ( P=0.600, 0.694, 0.802, 0.712); There was no statistically significant difference in the retina SCP blood flow density and perfusion density in the macular area ( P=0.347, 0.361). Conclusion:Compared with before surgery, there is no significant change in macular structure and blood flow density in sNPDR patients within 6 months after minimally invasive PPV.
8.Diet related knowledge and behavior among students in Anhui Province
CHEN Zhifei, MENG Can,GUAN Hengyan,PENG Ailing,LU Fen,LIN Chao,WANG Xiaohu,WU Jing,LI Weidong
Chinese Journal of School Health 2021;42(4):519-523
Objective:
To assess diet-related knowledge and behavior among primary and middle-school students in five cities of Anhui, and to provide evidence for nutrition education and intervention strategies.
Methods:
A multi stage stratified cluster random sampling method was used to select 2 045 students in five cities(Huaibei,Bengbu,Ma anshan,Hefei and Wuhu) of Anhui for a questionnaire survey on nutrition knowledge, diet behavior, food preferences, and diet education.
Results:
The overall rate of good nutritional awareness was 38.3%; students had the highest rate of awareness on plain water being the healthiest drink(91.6%). The overall rate of healthy food preferences was 51.5%, with milk and dairy products being the highest rated (66.4%). The overall rate of good diet behavior was 85.8%, with eating most meals on time and in appropriate quantities being the highest rated (87.7%). The overall rate of students with good diet education was 25.0%, while the rate of table cleaning was 73.0%. Middle school students had more knowledge of nutrition(χ 2=28.8), while primary school students had better healthy food preferences and diet behaviors(χ 2=31.3,77.6), and girls were more frequently involved in setting and clearing the table(χ 2=12.2)(P<0.05).
Conclusion
Insufficient nutrition knowledge, clear food preferences, unhealthy dietary behaviors, and a lack of diet education were observed in primary and middle school students in Anhui. Specific nutritional education in school settings should be developed, home school cooperation should be strengthened, and diet education activities should be increased to help primary and middle school students form a healthy lifestyle.
9. Distribution of the COVID-19 Epidemic and Correlation with Population Emigration from Wuhan, China
Zeliang CHEN ; Qi ZHANG ; Yi LU ; Zhongmin GUO ; Xi ZHANG ; Wenjun ZHANG ; Cheng GUO ; Conghui LIAO ; Qianlin LI ; Xiaohu HAN ; Jiahai LU
Chinese Medical Journal 2020;133(0):E008-E008
Background The ongoing new coronavirus pneumonia (Corona Virus Disease 2019,COVID-19) outbreak is spreading in China, but it has not yet reached its peak. Five million people emigrated from Wuhan before lockdown, potentially representing a source of virus infection. Determining case distribution and its correlation with population emigration from Wuhan in the early stage of the epidemic is of great importance for early warning and for the prevention of future outbreaks. Methods The official case report on the COVID-19 epidemic was collected as of January 30, 2020. Time and location information on COVID-19 cases was extracted and analyzed using ArcGIS and WinBUGS software. Data on population migration from Wuhan City and Hubei province were extracted from Baidu Qianxi, and their correlation with the number of cases was analyzed. Results The COVID-19 confirmed and death cases in Hubei province accounted for 59.91% (5806/9692) and 95.77% (204/213) of the total cases in China respectively. Hot spot provinces included Sichuan and Yunnan, which are adjacent to Hubei. The time risk of Hubei province on the following day was 1.960 times that on the previous day. The number of cases in some cities was relatively low, but the time risk appeared to be continuously rising. The correlation coefficient between the provincial number of cases and emigration from Wuhan was up to 0.943. The lockdown of 17 cities in Hubei province and the implementation of nationwide control measures efficiently prevented an exponential growth in the number of cases. Conclusion The population that emigrated from Wuhan was the main infection source in other cities and provinces. Some cities with a low number of cases showed a rapid increase in case load. Owing to the upcoming Spring Festival return wave, understanding the risk trends in different regions is crucial to ensure preparedness at both the individual and organization levels and to prevent new outbreaks.
10.Repair of complex soft tissue defects of lower extremities with anterolateral thigh chimeric perforator flap
Gaohong REN ; Xiaohu WU ; Yunbiao CHEN ; Mingmin ZHANG
Chinese Journal of Microsurgery 2020;43(5):435-440
Objective:To investigate the application of anterolateral thigh chimeric perforator flap in repairing complex soft tissue defects in lower extremities.Methods:From January, 2015 to June, 2019, 76 cases of complex soft tissue defects in lower extremities were repaired with free anterolateral thigh chimeric perforator flap pedicled with the descending branch of lateral circumflex femoral artery, including 29 cases in shank and 47 cases in ankle, and all had various tissue necrosis, infection, deep tissue defect and orthopaedic implant exposure. The size of the wound ranged from 15 cm×8 cm to 35 cm×20 cm, in which 45 cases associated with dead cavity formation, 62 cases with combined fractures at the same site, and 38 cases with combined fractures or other system injuries in other sites. After debridement, VSD treatment, good wound granulation and infection control, the chimeric perforator flap pedicled with the descending branch of the circumflex lateral femoral artery was designed and harvested. The perforator flap was used to repair most of the wounds with deep tissue exposures, the muscle flap was used to fill the dead cavity and (or) cover the wound around the flap, and free skin was grafted of the muscle flap at the first or second stage. Scheduled follow-up was conducted after the operation.Results:All 76 flaps survived, including vascular crisis occurred in 2 cases within 72 hours after surgery and ceased after immediate surgical exploration. One case had a further surgical operation due to excessive bleeding. Partial necrosis occurred at the distal end of the flap or the skin graft area of the muscle flap in 4 cases, of which 2 cases were treated with grafted skin again and the other 2 cases completely eliminated the wound after active dressing change. Other 16 cases of post-traumatic osteomyelitis with bone defect were repaired respectively with bone grafting, bone transportation or Masquelet technique in 3 to 6 months after wound healing. Among the 76 cases, 68 cases had primary wound healing while 8 cases delayed. Seventy-one cases were followed-up from 9 to 24 months, with an average of 16 months, while 5 cases lost. The appearance and function of the affected limbs recovered satisfactorily without recurrence of infection.Conclusion:With the anterolateral thigh chimeric perforator flap transplantation, the perforators flap can be conveniently used to repair the wound, and the muscle flap can be used to fill dead cavity and(or) deep wounds with free skin graft. Only the descending branch of lateral circumflex femoral artery is required to be anastomosed. It achieves a 3-dimensional effective reconstruction of the complex wound in extremities. It is a safe and effective technique to repair and reconstruct the complex wound in lower extremities and ideal in clinical applications.


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