BACKGROUND:Some scholars suggest that the nerve root palsy after cervical spinal stenosis treated with
decompression and implant internal fixation is related with the cervical stability and cervical lordosis, but there is controversial.
OBJECTIVE:To explore the C 5 nerve root palsy and stability after cervical spinal stenosis treated with posterior laminectomy lateral mass fixation and single-door decompression laminoplasty.
METHODS:Twenty-nine cervical spinal stenosis patients were selected and treated with posterior
decompression and implant internal fixation. Posterior laminectomy lateral mass fixation for the treatment of
cervical spinal stenosis:C3-6 lateral mass and C7 pedicel screw internal fixation was performed and caused rough surface on the facet joint;the unstable segment was confirmed according to the preoperative anteraposterior
plain film and dynamic radiographs combined with MRI and CT images, and then the corresponding segments were treated with lateral mass internal fixation, single-door decompression laminoplasty and laminoplasty.
RESULTS AND CONCLUSION:Al the 29 cervical spinal stenosis patients were fol owed-up for 8 months to 2.3 years. Among them, 14 cases were treated with posterior laminectomy lateral mass fixation, two cases had nerve root palsy in the early stage after implantation, three cases had incomplete paralysis after long-term symptom recurrence and treated with second surgery of scar remove and decompression;15 cases were treated with single-door decompression
laminoplasty, and one case had C 5 never root palsy and shoulder abduction dysfunctionafter treatment, no preoperative symptom recurrence. The nerve root palsy wil restored in 6 weeks for shortest and 9 months for longest. As the limitation of the case number, it is not clear whether there were significant differences in the correlation between C 5 nerve root
palsy and segmental stability, cervical lordosis, spinal decompression degree and the range for spinal cord shift, as wel as the nerve root palsy degree and the cervical spinal stenosis recurrence caused by forward scar between two
treatment methods, so accumulation observation of the cases and clinical experience are needed.

Objective To characterize the cardiac magnetic resonance (CMR) features of peripartum cardiomyopathy(PPCM) and idiopathic dilated cardiomyopathy(IDCM), and to explore the value of MRI in the diagnosis of PPCM. Methods Ten cases of PPCM and 10 cases of Idiopathic dilated cardiomyopathy (IDCM) were included in this study. With 1.5 T MRI scanner, the heart shape (atrioventricular size, hypertrabeculation, thickness of the thinnest ventricular wall), function (ventricular wall movement and the overall function), cardiomyopathy perfusion were comprehensively evaluated. Paired samples t?test and Fisher exact probability method were used for statistical analysis. Results Between PPCM and IDCM group, there was no statistical significant difference in the atrioventricular size, cardiac output(CO), end diastolic volume(EDV), ejection fraction (EF), end systolic volume (ESV) and stroke volume (SV) (P>0.05). IDCM and PPCM group both showed ventricular wall thinning on MRI, with 4 cases of PPCM and 3 cases of IDCM presenting hypertrabeculation in the left ventricular apex. Seven cases of PPCM and 4 cases of IDCM depicted left ventricular local dysfunction, while 3 cases of PPCM and 6 cases of IDCM had abnormal integral movement. Two cases of PPCM appeared local delayed enhancement, while 4 cases of IDCM showed intramural delayed enhancement. After one year of follow?up, heart function recovered in 10 cases of PPCM and 4 cases of IDCM. Conclusions MRI diagnosis using multiple sequences is an ideal method in the evaluation of PPCM. Although there were no differences in cardiac morphology and function between PPCM and IDCM, the prognosis of PPCM is better than IDCM.

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.

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.

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.

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.