C2 pedicle screw insertion assisted by mobilization of the vertebral artery in cases with high-riding vertebral artery / 中华外科杂志

Objective: To examine the feasibility, safety, and efficacy of mobilization of the vertebral artery for C2 pedicle screws in cases with high-riding vertebral artery (HRVA). Methods: The clinical data of 12 patients with basilar invagination and atlantoaxial dislocation underwent atlantoaxial reduction and fixation in the Department of Neurosurgery, the First Affiliated Hospital of University of Science and Technology of China between January 2020 and November 2021 were retrospectively analyzed. All patients had high-riding vertebral artery on at least one side that prohibited the insertion of C2 pedicle screws. There were 2 males and 10 females aged (48.0±12.8) years (range: 17 to 67 years). After correction of vertical dislocation during the operation, the C2 pedicle screw insertion and occipitocervical fixation and fusion were performed using the vertebral artery mobilization technique. Neurological function was assessed using the Japanese Orthopedic Association (JOA) scale. The preoperative and postoperative JOA score and the main radiological measurements, including the anterior atlantodental interval (ADI), the distance of the odontoid tip above the Chamberlain line, the clivus-canal angle, were collected and compared by paired t-test. Results: Mobilization of the high-riding vertebral artery was successfully completed, and C2 pedicle screws were then fulfilled after the vertebral artery was protected. There was no injury to the vertebral artery during the operation. Meanwhile, no severe surgical complications such as cerebral infarction or aggravated neurological dysfunction occurred during the perioperative period. Satisfactory C2 pedicle screw placement and reduction were achieved in all 12 patients. All patients achieved bone fusion 6 months after surgery. No looseness and shift in internal fixation or reduction loss was observed during the follow-up period. Compared to the preoperative, the postoperative ADI decreased from (6.1±1.9) mm to (2.0±1.2) mm (t=6.73, P<0.01), the distance of the odontoid tip above the Chamberlain line decreased from (10.4±2.5) mm to (5.5±2.3) mm (t=7.12, P<0.01), the clivus-canal angle increased from (123.4±11.1) ° to (134.7±9.6) ° (t=2.50, P=0.032), the JOA score increased from 13.3±2.1 to 15.6±1.2 (t=6.99, P<0.01). Conclusion: The C2 pedicle screw insertion assisted by mobilization of the vertebral artery is safe and considerably effective, providing a choice for internal fixation in cases with high-riding vertebral arteries.

Transmission cluster and network of HIV-1 CRF01_AE strain in China, 1996-2014 / 中华流行病学杂志

Objective: To understand the transmission patterns and risk factors of HIV-1 strain CRF01_AE subtypes in China, and to provide guidance for the implementation of precise intervention. Methods: A total of 2 094 CRF01_AE pol sequences were collected in 19 provinces in China between 1996 and 2014. Phylogenetic tree was constructed by PhyML 3.0 software to select the transmission clusters. Transmission network was constructed by Cytoscape 3.6.0, which was further used for exploring of the major risk factors. Results: Of the 2 094 sequences, 12.18% (255/2 094) were in clusters. A total of 82 transmission clusters were identified. The numbers of clusters and contained sequences in intra-provincial transmission (61, 173) were significantly more than those in inter-provincial transmission (21, 82). The ratio of transmission clustering in MSM increased over time from 2.41% (2/83) during 1996-2008 to 23.61% (72/305) during 2013-2014, showing a significant upward trend (χ(2)=27.800, df=1, P=0.000). The proportion of MSM with inter-provincial transmission clusters were higher than those with intra-provincial transmission clusters, which increased from 0.67% (2/297) during 1996-2008 to 6.36%(30/472) during 2013-2014, showing a significant upward trend (χ(2)=20.276, df=1, P=0.000). The transmission rate in homosexuals of the inter-transmission clusters (86.59%, 71/82) was higher than that of intra-provincial transmission clusters (56.65%, 98/173), and the difference was statistically significant (χ(2)=22.792, P=0.000). The proportion of inter-provincial transmission clusters with more than 2 transmission routes (33.33%, 7/21) was higher than that of intra-provincial clusters (13.11%, 8/61), and the difference was statistically significant (χ(2)=4.273, P=0.039). Results from the transmission network analysis indicated that the proportion of high risk population (degree≥4) with inter-provincial transmission clusters (51.22%, 42/82) was significantly higher than that with intra-provincial transmission clusters (26.59%, 46/173), and the difference was statistically significant (χ(2)=14.932, P=0.000). Inter-provincial clusters were mainly detected in and and MSM. Conclusions: Complex transmission networks were found for HIV-1 CRF01_AE strains in the mainland of China. Inter-provincial transmission clusters increased rapidly, MSM played an important role in the wide spread of the strain. More researches in transmission networks are needed to guide the precision intervention.

Pathogenic surveillance and related factors on bacillary dysentery in Beijing, 2008-2017 / 中华流行病学杂志

Objective: To analyze the pathogenic surveillance programs and related factors on bacillary dysentery in Beijing, 2008-2017, to provide evidence for the practices of diagnosis, treatment and prevention of the disease. Methods: Analysis was conducted on surveillance data of bacillary dysentery, collected from the surveillance areas of national bacillary dysentery in Beijing. Shigella positive rate of stool samples were used as the gold standard while detection rate of Shigella, diagnostic accordance rate and resistance were computed on data from the surveillance programs. Chi-square test was used to compare the rates and unconditional logistic regression was used to analyze the related factors of Shigella infection. Results: Both the reported incidence rate on bacillary dysentery and detection rate of Shigella in diarrhea patients showed significantly decreasing trend, from 2008 to 2017. The accordance rate of bacillary dysentery was only 7.80% (111/1 423). Shigella sonnei was the most frequently isolated strain (73.95%, 159/215) followed by Shigella flexnery. Results from the multivariate logistic regression of Shigella positive rate revealed that among those patients who were routine test of stool positive vs. routine test of stool positive (OR=1.863, 95%CI: 1.402-2.475), onset from July to October vs. other months'time (OR=7.271, 95%CI: 4.514-11.709) temperature ≥38 ℃vs. temperature <38 ℃(OR=4.516, 95%CI: 3.369-6.053) and age from 6 to 59 years old vs. other ages (OR=1.617, 95%CI: 1.085-2.410), presenting higher positive detection rates of Shigella from the stool tests. The resistant rates on ampicillin and nalidixic acid were 97.57% (201/206) and 94.90% (186/196), both higher than on other antibiotics. The resistant rates on ciprofloxacin (16.33%, 32/196), ofloxacin (9.57%, 11/115) and on amoxilin (15.05%, 31/206) were relatively low. The resistant rate appeared higher on Shigella flexnery than on Shigella sonnei. The proportion of strains with resistance on 3 more drugs, was 30.00%(21/70). Conclusions: The diagnostic accordance rate of bacillary dysentery in Beijing was low, with severe resistance of Shigella. Our findings suggested that clinicians should take multiple factors into account in their practices about epidemiological history, clinical symptom and testing results for diarrhea patients.

[Regional evapotranspiration of different land covers based on remote sensing].

In this paper, surface energy balance system (SEBS) was extended into a regional daily evapotranspiration (ET) estimation model based on remote sensing data, and the extended SEBS was applied to estimate the regional daily ET of Huanghe-Huaihe-Haihe rivers region in Northern China Plain by using MODIS/TERRA data. An analysis was made on the estimated daily ET characteristics of different land covers in the study area by using the spatial analysis module of ArcGIS. Since there were no field observations of ET on each land cover, the estimated daily ET of different land covers was compared with each other, taking the data on April 17, 2001 as an example. The results showed that the regional daily ET estimated by SEBS was reasonable. Wetland and cultivated land had the highest daily ET value, followed by forest-, bush- and grassland, and waste land. The characteristics of the daily ET over these land covers were accorded with the existing knowledge of ET over this region, and coincident to the results of previous work in this area. It was interesting that the residential area also had a higher ET value, which was explained as the higher ET of the land use types, e. g. , water body, street trees, and grass parcels in the resident areas within the pixel scale. The spatial inhomogeneity of ET among the forest-, bush-, grass- and cultivated land covers were caused by the spatial inhomogeneous soil water content under these land covers, and the spatial inhomogeneity of ET over cultivated land could be a potential indicator of making reasonable and effective irrigation schedule for the farmland. The limitations of using SEBS model in daily ET estimation were discussed, especially the possibility of underestimating the ET over water body and wetland covers due to the unsuitable surface parameterization scheme for these land types in the model.