Potassium metabolism in young adult men exercising in the heat for six consecutive days and the effect of potassium deficiency in mice and rats induced by low potassium diet during heat exposure were observed. Increased potassium loss in sweat and lower potassium intake resulted in negative potassium balance. Individuals with a negative potassium balance had lower se- rum potassium levels and higher body temperature after exercise. Potassium deficient mice accomplished less work done (2.372 vs 4.253 Kg.M) but exih-ibited a markedly greater rate of heat gain (1.36 vs 0.87℃/Kg.M) as compared to the controls. The survival rate and cellular energy metabolism also decreasedThese observations suggest that prevention from potassium deficiency must be emphasized during prolonged physical activity under hot environments. According to the linear regression equations between potassium intake and balance, it is proposed that the potassium requirements in mild and medium physical activity in the heat are 40 and 60 mEq/day respectively, and the allowance of potassium in the latter may be 70-80 mEq/day.

Objective To investigate the distribution characteristics of serum hepatitis B virus (HBV) markers of population in hospital and to provide the basis for prevention and control of virus B hepatitis .Methods 11 210 people in hospital who had accepted HBV serological testing were enrolled ,and were divided into >0 -25-year old group(n=3 553) and >25 -50-year old group(n=7 651) according to their ages .Enzyme-linked Immunosorbent Assay(ELISA) and Roche Cobas E601 Automatic Electro-chemiluminescence immunoassay analyzer were employed to detect serum HBV surface antigen (HBsAg ) ,anti-HBV surface anti-body(HBsAb) ,HBV e antigen(HBeAg) ,anti-HBV e antibody(HBeAb) and anti-HBV core antibody(HBcAb) .Results HBsAg positive rates of subjects in > 0 -25-year old group and > 25 -50-year old group were 16 .16% and 21 .19% ,respectively .The overall positive rates of HBsAg and HBsAb and full-negative rate were 19 .59% (2 195/11 204) ,37 .02% (4 148/11 204) and 11 .84% (1 327/11 204) ,respectively .Conclusion Distribution characteristics of HBV markers of population in hospital may pro-vide a reliable basis for taking effective protective and control measures against virus B hepatitis .

Objective To evaluate whether the reverse phase protein array (RPPA) method can be used for detecting TORCH infection in pregnant women .Methods The RPPA method was established for detecting TORCH infection .The positive coinci‐dence rates of TORCH infection detected by the RPPA method and ELISA method in 2000 fresh serum samples from pregnant women were compared for evaluating the feasibility of RPPA in TORCH detection .Results The positive coincidence rates of estab‐lished RPPA and ELISA for detecting TORCH infection was 100 .0% ,91 .1% ,97 .2% ,91 .3% and 93 .0% respectively ,indicating that the detection results of various indexes by RPPA and ELISA had better consistency (P>0 .05) ,but the positive detection rates of RPPA for Rubellavirus ,CMV and HSV‐1 ,2 were higher than those of correspondent ELISA method .Conclusion RPPA method for detecting TORCH infection has the advantages of simpleness ,rapidness ,high sensitivity and strong specificity ,is an effective method of auxiliary diagnosis for bearing and rearing better children in clinical ,and is worthy of being promoted and used in the fu‐ture .

Objective To establish a method of identification of DKO mouse model of Duchenne muscular dystro-phy, and to assess the dystrophin regeneration after stem cell transplantation.Methods Heterozygous mice were mated and the resulting offspring were used to identify their genotype by SSP-PCR.The plasma creatine kinase level was measured by biochemical analyzer and histological changes in the DKO mice were analyzed using HE staining.Human umbilical cord mesenchymal stem cells were prepared and injected into the DKO mice hindlimb muscle, and dystrophin expression was de-tected by immunofluorescence staining at 2 months after injection.Results Mating of heterozygous mice generated three kinds of genotype offsprings, and 21.2%of the offsprings were identified as DKO genotype (285 bp) .DKO mice showed dystrophic symptoms, their plasma creatine kinase level was as high as 16988.52 ±617.48 IU/L, and significant histologi-cal changes including diverse myocyte sizes, numerous centrally nucleated cells and connective tissue proliferation or in-flammatory cells infiltration.Human dystrophin expression was detected in the DKO mouse hindlimb muscle at two months after injection of human umbilical cord mesenchymal stem cells.Conclusion DKO mouse genotype can be identified by SSP-PCR, and DKO mouse is an ideal animal model for studies of stem cell therapy for Duchenne muscular dystrophy.

OBJECTIVE: To summarize the clinical features and the experiences of diagnosis and treatment of extramedullary plasmacytomas (EMPs), and to enhance the cure rates of EMPs. METHOD: Clinical data of 8 patients with EMPs in head and neck, who treated in our hospital from Jan. 1990 to Dec. 2004, were reviewed. Of 8 cases, 3 cases with the tumors occurred in nasal cavities, 1 in maxillary sinus, 2 in nasopharynx, 1 in posterior wall of oropharynx. RESULT: Eight patients who were all pathologic confirmed EMP accepted surgical resections of the tumors, and 4 of 8 cases were boosted radiation therapy post-operation. Four cases were still alive disease-free for more than 1, 5, 10 and 12 years after treatments, respectively. One died of local recurrence in 2 years, 1 died of multiple myeloma in 3 year, and 1 died of heart attack in 2 years after treatments, respectively. One lost follow-up. CONCLUSION EMPs in head and neck are low potential malignancy tumors. The diagnosis of EMPs mainly depends on clinical manifestations and pathological results. Surgery and radiation therapy are the main treatments for EMPs in head and neck.
Adult ; Aged ; Female ; Head and Neck Neoplasms ; diagnosis ; therapy ; Humans ; Male ; Middle Aged ; Plasmacytoma ; diagnosis ; therapy ; Retrospective Studies

Objective:To evaluate the accuracy of the domestic "Skywalker" surgical robot in implementing personalized lower limb alignment reconstruction scheme in total knee arthroplasty (TKA) and the short-term clinical outcome of robotic assisted TKA.Methods:From September 2020 to January 2021, the data of patients who received surgical robot assisted TKA in 5 clinical centers in China (Shanghai Ninth People's Hospital affiliated to Shanghai Jiao Tong University School of Medicine, Southwest Hospital affiliated to Third Military Medical University, The Affiliated Hospital of Qingdao University, The First Affiliated Hospital of Chongqing Medical University and Yantai Yuhuangding Hospital, and Shanghai Ninth People's Hospital affiliated to Shanghai Jiao Tong University School of Medicine was the group leader) were prospectively collected and retrospectively analyzed. There were 24 males and 82 females with an average age of 67.6±7.3 years, (range 45-80 years); Average body mass index 26.42±4.31 kg/m 2, all the operation were performed by "Skywalker" surgical robot system according to preoperative design based on CT. The operation time, intraoperative blood loss, hospitalization days and postoperative complications were recorded, and the imaging indexes including hip-knee-ankle (HKA), lateral distal angle of femur (LDFA) and medial proximal angle of tibia (MPTA) measured before and after the operation, implant model indexes (preoperative planning implant model and postoperative implant model) and short-term clinical efficacy indexes [Western Ontario and McMaster Universities (WOMAC) osteoarthritis index] pain score, stiffness score, joint function score, total score and SF-12 score before and 3 months after the operation) were compared. Results:The average follow-up period was 109.60±9.80 d, (range 95-143 d). The average operation time of 106 patients was 105.30±23.22 min; The average intraoperative blood loss was 141.70±58.33 ml; The average length of hospitalization was 5.82±2.80 d. One patient had ischemic stroke after operation, and one patient had abnormal liver function after operation. According to the judgment of the investigator, all of them were not related to the operation. The actual angle error is the difference between the preoperative planning angle and the postoperative measurement angle. The absolute error of 99.1% (105/106) of the HKA angle was within 3°, 90.8% (69/76) of LDFA, 98.7% (75/76) of the MPTA. In 45 patients in one center where data were available, the actual implant models used in all patients were consistent with the preoperative planning size, and there were only differences in version selection such as Asian condyle. WOMAC pain score, joint function score, total score was improved from 7.34±2.85, 25.10±9.85, 34.75±13.02 to 3.34±2.66, 14.68±9.64, 18.66±13.49 before and after operation, respectively, which were statistically significant ( P<0.001) and SF-12 physiological score and psychological score were improved form 27.24±6.42, 30.68±8.26 to 38.83±5.74, 39.36±7.85 before and after operation, respectively, which were statistically significant ( t=7.33, P<0.001; t=4.53, P=0.043). Conclusion:Domestic surgical robot system "Skywalker" can assist the surgeon to achieve accurate and personalized reconstruction of lower limb alignment and achieve satisfactory short-term clinical outcomes. The long-term clinical outcomes of personalized reconstruction and survival rate of implant still need to be further studied.

OBJECTIVE: To investigate the correlation of mental workload and prevalence of work-related musculoskeletal disorders musculoskeletal disorders( WMSDs) in railway vehicle manufacturing workers.METHODS: A total of 362 male workers in assembling and welding workshop from a railway vehicle manufacturing enterprise were selected as study subjects by cluster sampling method.The level of mental workload and prevalence of WMSDs were investigated using a revised Subjective Workload Assessment Technique and China Musculoskeletal Questionnaire.RESULTS: The median score of mental workload was 67 and the prevalence rate of WMSDs was 56.9%.The multivariate logistic regression analysis results indicated that the higher the mental workload of railway vehicle manufacturers,the higher their risk for WMSDs after excluding the influence of confounding factors( P < 0.05).Workers in welding work showed a higher risk than those in assembling work( P < 0.01).Workers with fast work rhythm showed higher risk of WMSDs than those with regular working rhythm( P < 0.01).Workers with comfortable working environment and temperature showed lower risk of WMSDs than those with uncomfortable working environment and temperature( P < 0.01).CONCLUSION: The mental workload can increase the risk of WMSDs,with a dose-effect relationship in railway vehicle manufacturing workers.The type of work,work frequency and the temperature in working environment are also influencing factors of WMSDs.

OBJECTIVE: To analyze the prevalence and influencing factors of multisite work-related musculoskeletal disorders(WMSDs) of workers in a railway vehicle manufacturing enterprise. METHODS: A total of 366 male workers in the assembly and riveting workshop of a railway vehicle manufacturing enterprise were selected as the research subjects using the cluster sampling method. The Chinese Musculoskeletal Questionnaire was used to investigate the prevalence of multiple sites of WMSDs. Multiple logistic regression analysis was used to analyze the influencing factors. RESULTS: The total prevalence of WMSDs was 56.3%(206/366). The prevalence of WMSDs in all parts from high to low was as follows: lower back(35.5%), hand and wrist(27.6%), neck(23.2%), shoulder(21.0%), knee(19.9%), upper back(18.6%), hip and leg(18.0%), ankle/foot(15.8%) and elbow(12.3%)(P<0.01). The total prevalence of multisite WMSDs was 38.0%(139/366). The prevalence of WMSDs in different numbers of parts from high to low was as follows: 6 or more parts(12.0%), 2 parts(10.7%), 3 parts(6.6%), 5 parts(5.5%) and 4 parts(3.3%)(P<0.01). Multiple logistic regression analysis results showed that the overweight and obese workers had higher risk of multi site WMSDs than those with normal body mass index(P<0.05).Those with long-term low heads, frequent bending, long bending of the elbows, and higher frequency of work requirements, and less frequently communicated with the leader had higher risk of multi site WMSDs(P<0.05). CONCLUSION: The prevalence of multisite WMSDs in railway vehicle manufacturing enterprise is relatively high. The influencing factors include individual factors, adverse ergonomic factors and psychosocial factors.