Objective To reflect the spatial distribution of brucellosis among 7 counties in Qinghai Province from 2011 to 2013 with Geographic Information System (GIS) map.Method Epidemiological situations were overlay analyzed in infectious rate and prevalence rate with QHEndemic-GIS and SPSS 17.0 by statistics and mapping.Results Brucellosis was detected in 7 counties through the spatial distribution map.The infectious rate and prevalence rate of brucellosis were showing a phenomenon of high and low alternation in 3 years;meanwhile the prevalence in Gonghe County showed an obviously upward trend with the rates of 0.50％ (1/201),1.50％ (3/200),and 3.73％ (9/241),respectively.Conclusions GIS could reflect the state of brucellosis infection directly and correctly.Prevalence of brucellosis in the 7 counties has showed a sporadic phenomenon,and the prevalence of brucellosis has covered a wide region and many populations are at risk of this disease.The prevalence has showed an up-ward trend in these regions,which provides a scientific basis for prevention and control of brucellosis in these key regions.

Objective To analyze the CT and magnetic resonance imaging (MRI) manifestations of the pelvic osteosarcoma. Methods The CT and MRI manifestations of 15 cases with pelvic osteosarcoma from January, 2013 to December, 2015 proved by histology were ret-rospectively analyzed. Results There were 10 males and 5 females in them. The median age was 27.0 years. Ilium was involved in 11 cases. A mixed lytic/sclerotic pattern of bone destruction was found in 11 cases, and the sclerotic type in 2 cases, the osteolytic type in 2 cases. Ra-dial periosteal reaction was found in 5 cases and immature bone formation in 8 cases. Soft tissue masses were seen in 13 cases. MRI showed enhancement in 15 cases and the CT showed no enhancement in 2 cases with sclerotic type. Conclusion The typical imaging manifestations of pelvic osteosarcomainclude mixed lytic/sclerotic appearance, radial periosteal reaction, soft tissue masses and immature bone formation.

Objective By summing up monitoring data of human brucellosis in Qinghai Province from 2000 to 2012, to evaluate epidemiological dynamics and analyze prevalence trend. Method Monitoring data of human brucellosis in Qinghai Province from 2000 to 2012 were collected, epidemiological characteristics including prevalence condition, area and population distribution were analyzed by descriptive epidemiology method. Results Totally 38 578 persons were examined from 2000 to 2012. The number of persons infected with brucellosis was 1 209, the infection rate was 3.34%;the number of patients diagnosed with human brucellosis was 344, the prevalence rate was 0.89%. New cases had occurred since 2006, and there were 158 new cases diagnosed with brucellosis. The prevalence rates in cities and areas of agriculture and pasture were 2.93%(78/2 663), 1.18%(33/2 806) and 0.70%(233/33 109), respectively. The ages of developing brucellosis ranged from 10 to 72 years old. The prevalence rates of biological pharmaceutical producers and the herdsman were [18.13%(196/1 081)] and [6.13%(353/5 763)], respectively. The prevalence rate of human brucellosis in Han nation was the highest [4.61%(467/10 140)], followed by Tibet [3.60%(443/12 318)], Mongolia [2.53%(211/8 342)], Tu [2.22%(110/4 953)] and Hui [2.09%(59/2 825)], and the differences were statistically significant (χ2 = 102.493, P < 0.01). Conclusion The prevalence state of human brucellosis in Qinghai Province is in a increasing trend, and new cases are increasing.

Objective To purify native F1 antigen from E pestis EV76 strain and determine its ef-ficacy against Y. pestis. Methods A new purification method was developed by the substitution of physical disruption ( glass beads) for organic solvent ( acetone and toluene) one, followed by a combination of ammo-nium sulfate fractionation and SephacrylS-200HR column filtration chromatography. Groups of mice were im-munized with F1 antigen adsorbed to 25% aluminum hydroxide in PBS by intramuscular route. The immu-nized animals were challenged subeutaneously(s, c. ) with 104 CFU of Y. pestis strain 141 at 18 weeks after the primary immunization. Results There was no IgG titre difference between two groups of mice with one-dose immunization, whereas in the two-dose immunization groups, the group F1-40 μg induced a statistically higher antibody titre than the group F1-20 μg. Complete protection was observed for animals immunized with purified F1 antigen by s.c. route. In contrast, the control mice immunized with aluminum hydroxide suc-cumbed to a same dose of Y. pestis 141 challenge. Conclusion This purification strategy is a simple and ef-fective, and can be operated in a large scale. Native F1 antigen extracted from Y. pestis EV76 is highly im-munagenic, and can be used as a key antigen component to develop sub-unit vaccine of plague.

Objective:To study the relationship between distal radioulnar joint (DRUJ) effusion and the integrity of triangular fibrcarotilage (TFC) in asymptomatic young adults.Methods:Thirty two asymptomatic young adults, 22 males and 10 females with a mean age of 25 year(20-30) were recruited in the study between September 2014 and October 2019. All subjects had no wrist pain, no wrist deformity or wrist mass, and had no history of wrist trauma or surgery. The DRUJ effusion was definedasfluid-like high signal intensityon fatsuppression proton density-weighted MRI.The presence of distal radioulnar joint effusion, the shape of the effusion, and the presence of triangular fibrocartilage abnormalities were documented.Results:Among 32 subjects, 25(78.1%, 15 males and 10 females) presented with distal radioulnar joint effusion on wrist MR images, including linear/tubular in 21 cases(84.0%) and saccular in 4 cases(16.0%).Twenty cases (62.5%) had distal radioulnar joint effusion while the TFC was intact, among whom, the effusion was confined to the proximal side of distal radioulnar jointin 17 cases, and reached the lower surface of TFC in 3 cases. In 5 cases (15.6%) with TFC tear, the effusion reached the lower surface of TFC in 4 cases. There were neutral, positive and negative variations of the ulna in 23, 6 and 3 cases, respectively, among whomthe distal radioulnar effusion was presented in 17, 5, 3 cases, and TFC tear in 1, 4 and 0 cases, respectively.The presence of distal radioulnar effusion was not significantly correlated with genders( P=0.069) or types of ulna variance( P=0.702). Conclusion:The distal radioulnar joint effusion maybe resent in asymptomatic young adults, and it maybe complicated with TFC tear.

Objective:To explore the anatomy and injuries features of the thumb extensor and flexor mechanism with MRI.Methods:Ten healthy subjects without thumb injury and 20 patients with thumb extensor or flexor mechanism injuries were recruited in the study between September 2013 and September 2021. All subjects underwent MRI examination, the MRI features of thumb extensor or flexor mechanism in healthy subjects and patients were analyzed. The imaging findings were compared with the surgical results and confirmed by followed up in patients.Results:The healthy subjects showed homogeneous low-signal-intensity on T1-weighted and proton-fat saturation sequence(PD FS) images. Twenty patients with thumb extensor or flexor mechanism injures(including 8 cases of extensor pollicislongusinjury,1 case of extensor pollicisbrevis injury, 4 cases of flexor pollicislongus injury, 2 cases offlexor pollicis brevis injury and 5casesofpulley injury) demonstrated poor definition in T1WI, and heterogeneously increased signal intensity in PD-FS. Depending on the degree of injury, the fibers may be partially or completely discontinuity of the involved tendons. There was edema in the soft tissues surrounding the injured sites.Conclusion:MRI is an accurate method for evaluation of the anatomy and pathological conditions of the thumb extensor and flexor mechanism.

Plague is an anthropozoonotic disease caused by the Yersinia pestis,which developed by many factors including local climate factors.In recent years,more and more studies on the effects of climate on plague were conducted.According to the researches,climate factors (mainly the rainfall and temperature) affected the development and distribution of plague by influencing the abundance of plague host animals and fleas index.The climate also affected the epidemic dynamics and the scope of plague.There were significant differences existing in the influence of climate on the palgue developed in the north and south China.In the two different plague epidemic systems,the solitary Daurian ground squirrel-flea-plague and the social Mongolian gerbil-flea-plague,the obvious population differences existed among the responses of the host animal to the climate changes.Although the internal relationship between the rainfall,the flea index,the density of rodents and the plague supported the nutritional cascade hypothesis,it can not prove that there is a clear causality between the occurrence of plague and rainfall.So the influence of climate factors on plague distribution can only be used for early forecasting and warning of the plague.

Plague is an anthropozoonotic disease caused by the Yersinia pestis,which developed by many factors including local climate factors.In recent years,more and more studies on the effects of climate on plague were conducted.According to the researches,climate factors (mainly the rainfall and temperature) affected the development and distribution of plague by influencing the abundance of plague host animals and fleas index.The climate also affected the epidemic dynamics and the scope of plague.There were significant differences existing in the influence of climate on the palgue developed in the north and south China.In the two different plague epidemic systems,the solitary Daurian ground squirrel-flea-plague and the social Mongolian gerbil-flea-plague,the obvious population differences existed among the responses of the host animal to the climate changes.Although the internal relationship between the rainfall,the flea index,the density of rodents and the plague supported the nutritional cascade hypothesis,it can not prove that there is a clear causality between the occurrence of plague and rainfall.So the influence of climate factors on plague distribution can only be used for early forecasting and warning of the plague.

Objective:To explore the magnetic resonance imaging (MRI)features of the normal anatomy and injuries of ligaments in the elbow joint.Methods:Thirty-eight healthy volunteers (38 sides) and 82 patients with elbow joint injuries were recruited in the Radiology Department of Beijing Jishuitan Hospital from February 2019 to February 2022 and the MRI findings were analyzed. The healthy subjects had no history of trauma, elbow joint ligament injury or pain, and the elbow joint function was normal. Among the 82 patients with elbow joint injuries, 8 cases were confirmed by operation and 74 were confirmed by follow-up. The MRI characteristics of normal anatomy and injuries of the medial collateral ligament and lateral collateral ligament complex of the elbow were compared and analyzed by blind method.Results:The medial collateral ligament and lateral collateral ligament complex in 38 healthy volunteers showed as thin strip low signal on T1-weighted imaging (T1WI) and fat suppression proton density-weighted imaging (PD-FS), and the annular ligament showed as annular linear low signal surrounding the radial head. Among the 82 patients with elbow injuries, in the medial side, there were 6 cases with medial collateral ligament injuries alone, 2 with common flexor tendon injuries alone, and 4 with medial collateral ligament and common flexor tendon injuries; while in the lateral side, there were 9 cases with the lateral collateral ligament complex injuries alone, 21 with common extensor tendon injuries alone, and 31 with the lateral collateral ligament complex and common extensor tendon injuries. In addition, there were 9 cases of medial collateral ligament coupled with lateral collateral ligament complex injuries. Among the 9 cases of combined ligament injuries (5 cases with injuries of the common flexor or extensor tendon), 5 cases were complete tears and 4 cases were partial tears. Among the 10 cases of medial collateral ligament injuries, 9 patients were strain and one was complete tear. Among the 40 cases of lateral collateral ligament complex injuries, 29 patients were strain, 10 were partial tears and one was complete tear. The strained ligament showed as thickened and blurred on T1WI, and the fiber was still continuous; while on PD-FS, the injured ligaments demonstrated as heterogeneously increased signal intensity. Partial tear showed as fiber thickening and partial discontinuity. A complete tear showed that the fiber was discontinuous and retracted with surrounding soft tissue edema.Conclusion:MRI is an accurate method for evaluation of the anatomy and pathological conditions of the medial collateral ligament and lateral collateral ligament complex of the elbow joint, and has important application value in the diagnosis and treatment of elbow ligament injury.

Objective:To explore the optimal keV value of the virtual monoenergetic image (VMI) for displaying the osteosarcoma by using the dual-layer spectral detector CT and to evaluate its application value in determining the extent of intramedullary invasion of osteosarcoma.Methods:From August 2021 to August 2022, 57 patients with conventional osteosarcoma of long bone confirmed by biopsy in Beijing Jishuitan Hospital, Capital Medical University were retrospectively analyzed. All patients completed dual-layer spectral CT enhanced examination before limb salvage surgery, and tumor segment resection specimens were obtained after surgery. Conventional 120 kVp image and VMI of 40, 50, 60, 70 and 80 keV were obtained by spectral CT examination, and the CT values of tumors, image noise were measured and the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of the corresponding images were calculated. The objective evaluation among the six groups of images were assessed with the Friedman test, and then determined the optimal keV value. The maximum distance between the intramedullary boundary of osteosarcoma and the adjacent articular surfaces was measured on the best keV VMI and the tumor segment resection specimens. The Wilcoxon signed rank test was used to find the differences and the Spearman correlation analysis was used to evaluate the correlation between the distance measured from the best keV VMI and the specimens.Results:There were significant differences in CT value, image noise, SNR and CNR between 40-80 keV VMI and 120 kVp conventional CT images ( P<0.05). The CT value, SNR and CNR of 40 and 50 keV VMI were better than 120 kVp ( P<0.001). The 50 keV VMI was chosen as the best keV VMI to measure the intramedullary extent of osteosarcoma. The distance measured from 50 keV VMI was 103.9 (80.4, 131.4) mm, while the distance measured from specimens was 113.5 (94.0, 142.0) mm, and the difference was statistically significant ( Z=-5.76, P<0.001). The 50 keV VMI measurements in 51 patients were smaller than the gross specimens, which underestimated the tumor intramedullary extent, with the difference was 11.1 (6.6, 13.8) mm. The Spearman correlation analysis demonstrated a high positive correlation of distance measured on gross specimens with the 50 keV VMI ( r s=0.960, P<0.001). Conclusions:Dual-layer spectral detector CT with 50 keV VMI is the best image to show the limb osteosarcoma. Compared with gross specimens, the distance measured from CT underestimated the intramedullary invasion range of limb osteosarcoma about 10 mm, but the two show a good correlation.