Objective To explore the peak moment characteristics of lower limb joints,as well as the contribution rate and compensation mechanism of lower limb joints when older adults with a history of falls cross obstacles at different paces.Methods Thirty healthy older adults and 30 eldely fallers were recruited.The Qualisys infrared high-speed motion capture system and the Kistler three-dimensional force platform were used to collect the biomechanical data of the older adults when they crossed an obstacle with a height of 15％of their height at three walking speeds(1.05,1.41,1.74 m/s).The data were then modeled and analyzed using Visual 3D software.Results As walking speed increased,the peak knee extension moment,peak ankle plantar flexion moment,and double peak value of hip flexion moment in healthy group all increased significantly(P＜0.05).Compared with healthy group,the double peak values of hip flexion moment in faller group were significantly smaller than those in healthy group(P＜0.05).During walking at moderate speed,the contribution rate of the left hip joint in faller group was significantly higher than that of healthy group(P=0.025),while the contribution rate of the ankle joint was significantly lower(P=0.044).The margin of stability in the anterior-posterior direction at the moment of ground contact of the stance leg and the stride leg increased with walking speed(P=0.007,P=0.002).Conclusions Compared with healthy older adults,the elderly fallers have lower peak torque,peak ground reaction force,and dynamic stability in the anterior-posterior direction.As the walking speed increases,the mechanical parameters and the margin of stability of older adults increase significantly,and walking stability is improved.Compared with healthy older adults,elderly fallers usually rely more on the contribution of hip joint movements and reduce the involvement of ankle joints.It is recommended to incorporate fast walking exercises into the daily fall prevention exercise program for older adults,with combination of coordinated training of the hip,knee,and ankle joints.

Objective To explore the peak moment characteristics of lower limb joints,as well as the contribution rate and compensation mechanism of lower limb joints when older adults with a history of falls cross obstacles at different paces.Methods Thirty healthy older adults and 30 eldely fallers were recruited.The Qualisys infrared high-speed motion capture system and the Kistler three-dimensional force platform were used to collect the biomechanical data of the older adults when they crossed an obstacle with a height of 15％of their height at three walking speeds(1.05,1.41,1.74 m/s).The data were then modeled and analyzed using Visual 3D software.Results As walking speed increased,the peak knee extension moment,peak ankle plantar flexion moment,and double peak value of hip flexion moment in healthy group all increased significantly(P＜0.05).Compared with healthy group,the double peak values of hip flexion moment in faller group were significantly smaller than those in healthy group(P＜0.05).During walking at moderate speed,the contribution rate of the left hip joint in faller group was significantly higher than that of healthy group(P=0.025),while the contribution rate of the ankle joint was significantly lower(P=0.044).The margin of stability in the anterior-posterior direction at the moment of ground contact of the stance leg and the stride leg increased with walking speed(P=0.007,P=0.002).Conclusions Compared with healthy older adults,the elderly fallers have lower peak torque,peak ground reaction force,and dynamic stability in the anterior-posterior direction.As the walking speed increases,the mechanical parameters and the margin of stability of older adults increase significantly,and walking stability is improved.Compared with healthy older adults,elderly fallers usually rely more on the contribution of hip joint movements and reduce the involvement of ankle joints.It is recommended to incorporate fast walking exercises into the daily fall prevention exercise program for older adults,with combination of coordinated training of the hip,knee,and ankle joints.

Objective Toinvestigatetheconsistencyofultrasoundand MSCTindiagnosing microvascularinvasion (MVI)in hepatocellularcarcinoma,andtocomparethediagnosticefficiencyofbothtwomethods.Methods TheultrasoundandMSCTdataof 82patientswithhepatocellularcarcinomawerecollected.Accordingtothepostoperativepathologicalresults,theconsistencyanddiagnostic efficiencyofultrasoundandMSCTindiagnosingMVIinhepatocellularcarcinomawerecompared.Results Accordingtothepostoperative pathologicalfindingsof82patients,30caseswerepositiveofMVI,while52caseswerenegative.ThepreoperativeMSCTandultrasound examinations had a strong consistency (Cohen’s Kappa＝0.829 ,P＜0.001 ).The sensitivity ,specificity and accuracy of preoperative ultrasoundinpredictingtheMVIinhepatocellularcarcinomawere76.67% (23/30),67.31% (35/52)and70.73% (58/82),respectively. Thesensitivity,specificityandaccuracyofpreoperativeMSCTinpredictinghepatocellularcarcinomaMVIwere83.33% (25/30),73.08%(38/52)and75.61% (63/82),respectively.Conclusion Preoperativeultrasoundand MSCThavegoodconsistencyandhighdiagnostic efficiencyindiagnosing MVIinhepatocellularcarcinoma.

Objective: To observe the clinical effects of stage-Ⅱ Meek skin grafting on adipose tissue after tangential excision in patients with extensive deep burns, and to explore the functional mechanism. Methods: The medical records of 26 extensively burned patients who met the inclusion criteria and were admitted to the Department of Burns and Plastic Surgery of the Fourth Medical Center of PLA General Hospital from May 2015 to December 2017 were retrospectively analyzed. According to the treatment methods, 14 patients were enrolled in stage-Ⅰ skin grafting group (10 males and 4 females, aged 27 to 75 years), and 12 patients were enrolled in stage-Ⅱ skin grafting group (10 males and 2 females, aged 31 to 76 years). Patients in the 2 groups all underwent debridement of tangential excision, and their healthy adipose tissue was preserved. Meek skin grafting was performed just after tangential excision in patients in stage-Ⅰ skin grafting group. In patients in stage-Ⅱ skin grafting group, porcine acellular dermal matrix (ADM) was applied to cover the wound after tangential excision, and 3 days later, it was removed and Meek skin grafting was performed. The times of complement skin grafting and the wound basic healing time of patients in the 2 groups were observed and recorded. In the stage-Ⅱ skin grafting group, the adipose tissue of patients were taken from the wound center immediately after tangential excision and immediately after the removal of porcine ADM, for the observation of structure of the fault surface of adipose tissue through hematoxylin and eosin staining and microvessel density (MVD) through immunohistochemical staining. Data were processed with independent sample t test and Fisher′s exact probability test. Results: (1) The times of complement skin grafting of patients in stage-Ⅱ skin grafting group was (1.83±0.17) times, which was obviously less than (3.36±0.63) times in stage-Ⅰ skin grafting group (t=2.19, P<0.05). The wound basic healing time of patients in stage-Ⅱ skin grafting group was (35.1±2.3) d, which was obviously shorter than (48.8±4.9) d in stage-Ⅰ skin grafting group (t=2.27, P<0.05). (2) Immediately after tangential excision, the intercellular substance was few between the adipose cells in adipose tissue of patients in stage-Ⅱ skin grafting group. Immediately after the removal of porcine ADM, there was regenerated granulation tissue in the intercellular space of adipose cells of adipose tissue of patients in stage-Ⅱ skin grafting group. Immediately after tangential excision, the MVD of adipose tissue of patients in stage-Ⅱ skin grafting group was 20.2±1.3 under per 400-time field, which was obviously less than 32.2±1.9 under per 400-time field immediately after the removal of porcine ADM (t=-5.38, P<0.01). Conclusions Meek skin grafting on the adipose tissue in stage-Ⅱ surgery after tangential excision could reduce the times of complement skin grafting and shorten wound healing time of patients with extensive deep burns. The mechanism may be related to the improvement of the recipient condition of adipose tissue.

Objective: To investigate the detection of thyroid nodules and related risk factors in nuclear power workers, and to provide scientific evidence for thyroid protection of nuclear power workers. Methods: In December 2018, select 295 workers of a nuclear power production enterprise and 238 administrative staff of it, and select 250 staff members of a thermal power generation enterprise 70 kilometers away from the nuclear power station to conduct thyroid ultrasound examination and questionnaire survey for single factor. Analysis and further multivariate logistic regression analysis were used to study the risk factors of thyroid nodules in the population. Results: Women and smoking history were independent risk factors for the increased incidence of thyroid nodules in the study population; three shifts work pattern was an independent risk factor for the increased prevalence of thyroid nodules in nuclear power workers (P<0.05) , and other factors such as the history of nuclear exposure had no significant correlation with thyroid nodules (P>0.05) . Conclusion Nuclear exposure has little effect on the prevalence of thyroid nodules in nuclear power workers.

Objective: To study the effect of different doses of low molecular weight heparin on coagulation mechanism after thoracic surgery. Methods: A prospective randomized controlled study was conducted to select patients who underwent thoracic cancer surgery (lung cancer, esophageal cancer, cardiac cancer) from February 2015 to October 2018. According to the Caprini risk assessment model, 101 patients with high risk of deep venous thrombosis were randomly assigned to groups A, B and C. Control group A (34 cases) did not use low molecular weight heparin; group B (34 cases) used prophylactic low molecular weight heparin calcium after operation; group C (33 cases) used therapeutic low molecular weight heparin calcium after operation. The platelet count (PLT), fibrinogen (FIB), prothrombin time (PT), D-dimer (D-D), postoperative thoracic drainage and lower extremity deep vein ultrasound were observed before and after operation. Results: The incidence of deep venous thrombosis (DVT) was 11.76% in group A, 2.94% in group B and 3.03% in group C, with significant difference between group B and C and group A (P<0.05), but there was no significant difference between group B and C (P>0.05). The levels of FIB and D-D after operation were significantly higher than those before operation (P<0.05), but the levels of indexes in group B and C were significantly lower than those in group A (P<0.05). Conclusions Low molecular weight heparin calcium does not increase bleeding and thoracic drainage, which is beneficial to improve the hypercoagulable state of patients and has good safety. However, the use of low molecular weight heparin calcium in different doses (prevention amount and treatment amount) has no significant effect on the occurrence of lower extremity deep vein thrombosis and coagulation index.

Objective: To observe the effects of minimally invasive tangential excision in treating deep partial-thickness burn wounds on trunk and limbs in pediatric patients in the early stage post burn. Methods: Clinical data of 40 children with deep partial-thickness burn wounds on trunk and limbs, admitted to our burn ward from January 2016 to June 2017, conforming to the study criteria, were retrospectively analyzed. They were divided into conventional treatment group (CT, n=19) and minimally invasive tangential excision group (MITE, n=21) according to the different treatments. The patients in group CT were treated with eschar-reserving therapy firstly. When tangential excision was performed, the roller knife was used, and no necrotic tissue left on the wound bed was considered the proper depth of excision. Razor-thickness skin grafting was performed to cover the wound when adipose tissue exposed markedly after tangential excision. Dressing change was performed within 48 h after the operation and repeated every 2 days. Unhealed wounds were covered by razor-thickness skin grafting. The patients in group MITE were treated with tangential excision in the early stage post burn. The tangential excision was operated with electric dermatome, and the thickness was set at 0.1 mm to excise the surface of eschar until the sporadic punctate hemorrhage on wound surface was observed and some necrotic tissue was left on the wound bed. Porcine acellular dermal matrix was applied after tangential excision. The first dressing change was often performed about 1 week after the operation. Razor-thickness skin grafting was performed to cover the unhealed wounds. The length of wound healing, high fever, antibiotic usage, and hospital stay, times of later operation, and hospitalization expenses of patients in the 2 groups were recorded. The excisional eschar and wound bed tissue of patients in group MITE were harvested for pathological observation. Data were processed with t test and Fisher′s exact probability test. Results: (1) There were no statistically significant differences in length of high fever and length of hospital stay and hospitalization expenses between patients in the 2 groups (t=-1.67, -1.93, 0.31, P>0.05). The lengths of wound healing [(24.8±2.5) d] and antibiotic usage [(4.4±0.7) d] of patients in group MITE were significantly shorter than those in group CT [(33.3±2.5) and (7.0±0.7) d, t=-2.44, -2.44, P<0.05], and times of later operation of patients in group MITE [(0.29±0.14) times] were significantly less than those in group CT [(0.79±0.21) times, t=-2.03, P<0.05]. (2) The thickness of the excisional eschar of patients in group MITE was about 150 μm. The eschar has epidermis and upper dermis. Some necrotic tissue was left on the wound bed. Conclusions The treatment for pediatric deep partial-thickness burn wounds on trunk and limbs with minimally invasive tangential excision using electric dermatome in the early stage post burn can accelerate wound healing, shorten length of antibiotic usage, and reduce times of later operations.

OBJECTIVETo investigate the clinical phenotype and ACAT1 gene mutation in a family affected with beta-ketothiolase deficiency (BKTD).

METHODSClinical features and laboratory test data were collected. The probands were monozygotic twin brothers. Genomic DNA was isolated from peripheral blood leukocytes obtained from the probands and their family members. Molecular genetic testing of the ACAT1 gene was carried out.

RESULTSThe probands have presented with fever, vomiting and severe ketoacidosis. By arterial blood gas testing, pH was determined to be 7.164, bicarbonate was 4.0 mmol/L, and urine ketone was ++++. Urinary organic acid gas chromatography-mass spectrometry analysis showed excessive excretion of 3-hydroxybutyric acid, 2-methyl-3-hydroxybutyric acid and tiglylglycine. Increased 3-hydroxybutyrylcarnitine (C4-OH), tiglylcarnitine(C5:1) and 3-hydroxyisovalerylcarnitine (C5-OH) levels. The clinical phenotype of proband's parents were both normal, but an elder sister turned out to be an affected patient. Genetic analysis has identified two heterozygous mutations [c.622C>T(p.R208X) and c.653C>T (p.S218F)] in the proband, which were respectively detected in the mother and father. The c.653C>T (p.S218F) mutation was not found among the 100 healthy controls and has not been included in the Human Gene Mutation Database(HGMD).

CONCLUSIONThe primary clinical manifestations of BKTD is ketoacidosis. Urine organic acid and blood acylcarnitine analyses play an important role in the diagnosis of the disease. The compound heterozygous of ACAT1 gene mutations probably underlie the BKTD in our patient.

Acetyl-CoA C-Acetyltransferase ; genetics ; Acetyl-CoA C-Acyltransferase ; deficiency ; genetics ; Amino Acid Metabolism, Inborn Errors ; genetics ; Computational Biology ; Female ; Humans ; Infant ; Male ; Mutation ; Phenotype

OBJECTIVETo explore pathogenic mutation in a family affected with 2-hydroxyglutaric aciduria.

METHODSExons of 3 candidate genes, including L2HGDH, D2HGDH and SLC25A1, were amplified with polymerase chain reaction and subjected to direct sequencing.

RESULTSDNA sequencing has found that the proband and his affected younger brother have both carried a heterozygous mutation c.845G>A (p.R282Q) in the exon 7 of the L2HGDH gene. The same mutation was not detected in the his sister who was healthy. Pedigree analysis has confirmed that the above mutation was inherited from the mother. No mutation was detected in exons and flanking sequences of the D2HGDH and SLC25A1 genes.

CONCLUSIONMutation of the L2HGDH gene probably underlies the 2-hydroxyglutaric aciduria in this family.

Alcohol Oxidoreductases ; genetics ; Base Sequence ; Brain ; diagnostic imaging ; Brain Diseases, Metabolic, Inborn ; diagnostic imaging ; enzymology ; genetics ; Child ; Female ; Humans ; Male ; Molecular Sequence Data ; Mutation ; Pedigree ; Radiography ; Young Adult

Objective:To investigate the value of color doppler flow imaging (CDFI) in the diagnosis of liver cirrhosis upper gastrointestinal bleeding in portal vein hemodynamic changes. Methods: 96 cases of patients with liver cirrhosis were selected who were diagnosed in our hospital, according to the history whether patients had a gastrointestinal bleeding or not. They were divided into bleeding group(45 cases) and no bleeding group(51 cases). At the same time, we chose the hospital physical examination center of 42 cases of healthy volunteers as a control group, using color doppler flow imaging portal venous blood flow mechanics parameters, including diameter, average blood flow velocity and blood flow of portal vein(PV) and splenic vein(SV) and compare the data of the three groups.Results: Compared with control group, the patients with liver cirrhosis, the blood vessel diameter have increased whether bleeding or not. The average blood flow velocity is slower and PVF is larger, and the differences between them are statistically significant(t=3.579,t=3.670,t=4.750,t=3.951,t=6.116,t=5.371;P<0.05). Conclusion: The clinical application of color doppler flow imaging(CDFI) in patients with cirrhosis portal hemodynamic change is not only simple noninvasive, and there is important diagnostic value in the detecting parameters.