[Research on the influence factors of the carrying system]

Objective: To investigate surface electromyography signal (sEMG) of the major back muscle group and subjective fatigue assessment under different experimental combinations during walk with weight on both shoulders, as well as the functional status and fatigue property of human muscles. Methods: From October to December, 2017, 10 college students were recruited to participate in shoulder weight-bearing work and walk under the combinations of different shoulder strap widths, weights, and hardness of waist cushion. The subjects were required to complete 12 sets of experiments, with each set lasting for 15 minutes, and the rest time between work was 30 minutes. The sEMG signals of the upper trapezius and the erector spinae were measured during the experiment, and subjective fatigue assessment was performed during rest. The time domain evaluation index (average amplitude, aEMG) , the frequency domain evaluation index (median frequency, MF) , and the data of subjective assessment were processed and analyzed. Results: Weight and shoulder strap width had a significantly effect on fatigue (P<0.01) , and the change in the hardness of waist cushion had no significant effect on fatigue (P>0.05) . There was an interaction effect between weight and shoulder strap width (P<0.01) , and there was no interaction effect between weight, shoulder strap width, and hardness of waist cushion (P>0.05) . For the backpack carrying system, the combination of 10% weight and 50 mm shoulder strap width was the best one for relieving fatigue. The subjective test also showed that subjective feelings of muscle fatigue were associated with the weight and width, which was consistent with sEMG results. Conclusion: The results of this experiment show that the combination of 10% weight and 50 mm shoulder strap width can help to relieve muscle fatigue during walk with weight on both shoulders, and weight-bearing walking is more likely to cause the fatigue of the erector spinae.

[Analysis of characteristics and influence factors of diagnostic delay of endometriosis]

Objective: To access the influence factors of diagnostic delay of endometriosis. Methods: We designed a questionnaire of diagnostic delay of endometriosis. From February 2014 to February 2016, 400 patients who had dysmenorrhea and diagnosed with endometriosis by surgery in Peking University Third Hospital were surveyed retrospectively. Time and risk factors of diagnostic delay were analyzed. Results: The diagnostic delay of 400 patients was 13.0 years (0.2-43.0 years), 78.5%(314/400) patients thought pain was a normal phenomenon and didn't see the doctor. Patients who suffered dysmenorrhea at menarche experienced longer diagnostic delay than those who had dysmenorrhea after menarche (18.0 vs 4.5 years; Z=191.800, P<0.01) . Patients who suffered aggravating dysmenorrhea experienced shorter delay time than those who suffered stable or relieving dysmenorrhea (11.0 vs 12.5 vs 18.0 years; Z=8.270, P<0.05) , with the difference statistically significant, single factor analysis shows. Severe dysmenorrhea, deep infiltration endometriosis (DIE) , family history of dysmenorrhea or endometriosis, previous surgical history of endometriosis, high stage, with infertility, adenomyoma or other symptoms, could help to shorten diagnostic delay with no significant difference (P>0.05) . By multiple logistic regression analysis, the results shown that whether have dysmenorrhea at menarche and clinical diagnosis time were the independent factors affecting delayed diagnosis (P<0.01) . Conclusions: Diagnostic delay of endometriosis is common and the mean delay time is 13.0 years mainly due to the unawareness of dysmenorrhea. Dysmenorrhea at menarche, clinical diagnosis time and dysmenorrhea intensity are the factors affecting time of diagnostic delay.

[Association between high-sensitivity C-reactive protein and both cardiovascular, total mortality events in middle-aged Chinese adults]

Objective: To estimate the association between high-sensitivity C-reactive protein (hs-CRP) and cardiovascular events as well as all-cause mortality events. Methods: During 2009- 2010, out of the 11 623 individuals, 1 000 participants aged 35-64 years, were recruited and divided into 12 age-groups, to have received a study on CVD risk factors. Information on the risk factors of cardiovascular diseases was also collected. Fasting blood sample was gathered for all the participants, with hs-CRP tested. Participants in 7 out of the 12 sites were followed, with 6.21 years (36 075 person-years) as the median follow-up period. Cardiovascular and all-cause mortality events were collected. A total of 6 177 participants had been followed after excluding participants who had baseline infections, or did not take hs-CRP test/physical examination at the baseline. Finally, 5 984 participants were included for analysis. Participants were categorized into three groups based on the hs-CRP (mg/L) values: <1, 1-3 and >3, respectively. Cox proportional hazards regression model was used to analyze the relationships between hs-CRP with cardiovascular events or all-cause mortality events, after adjusting for confounding factors. Results: Mean age of the participants was 50.2 years. The incidence rates of cardiovascular disease events were 3.6/1 000 person-years, 7.1/1 000 person-years,and 10.4/1 000 person-years among three groups and 3.0/1 000 person-years, 5.7/1 000 person-years, 9.1/1 000 person-years for all-cause mortality events, respectively. After adjusting for confounding factors, the hazard risks (HR) for cardiovascular events were 1.33 (95%CI: 0.95-1.84) in the hs-CRP 1-3 mg/L group and 1.76 (95%CI: 1.20-2.60) in the hs-CRP>3 mg/L group when comparing with the hs-CRP<1 mg/L group (trend test P=0.003). The HRs for all-cause mortality events were 1.76 (95%CI: 1.23-2.54) and 2.64 (95%CI: 1.74-4.01) (trend test P<0.001), respectively. Conclusion: Hs-CRP appeared an independent predictor for cardiovascular events and all-cause mortality events.

[Comparison of outcomes of two minimally invasive approaches for multi-vessel coronary revascularization]

OBJECTIVE

To compare the safety and effectiveness of two minimally invasive approaches for multi-vessel coronary revascularization.

METHODS

From August 2014 to February 2017, 70 consecutive patients who underwent minimally invasive coronary artery bypass grafting in Peking University Third Hospital were randomly divided into two groups. In one group, 40 patients underwent staged-hybrid coronary revascularization (staged-HCR) treatment; in the other group, 30 patients underwent minimally invasive total arterial revascularization with bilateral internal thoracic artery (BITA). In staged -HCR group, the patients underwent minimally invasive direct coronary artery bypass grafting (MIDCAB) and percutaneous coronary intervention (PCI) procedure for treatment of multi-vessel disease. In BITA group, the patients underwent total arterial coronary artery bypass grafting with composite "Y" BITA graft. Preoperative and postoperative data of the two groups, including postoperative blood usage, mechanical ventilation time, domiciling duration in intensive care unit (ICU), major adverse cerebral and cardiovascular event (MACCE), and postoperative coronary angiography results were compared, in order to evaluate the safety and effectiveness of these surgical approaches.

RESULTS

The preoperative characteristics of 70 patients in the two groups showed no significant difference. All the patients underwent successfully, elective minimally invasive multi-vessel coronary artery bypass grafting as scheduled preoperatively. Postoperative result showed the patients in staged-HCR group took advantages in less postoperative mechanical ventilation time [Staged-HCR group (11.2±8.7) h vs. BITA group (18.3±9.1) h, P=0.013], shorter domiciling duration in ICU [Staged-HCR group (26.29±4.05) h vs. BITA group (44.74±28.75) h, P=0.022], and less total drainage [Staged-HCR group (695.57±250.46) mL vs. BITA group (1 103.26±547.44) mL, P=0.03] than the patients in the group of minimally invasive total arterial revascularization with BITA. Postoperative in hospital coronary angiography showed satisfactory graft patency rates in both groups [97.5% in Staged-HCR group vs. 97.8% in BITA group]. No MACCE occurred in both groups during hospitalization.

CONCLUSION

Staged-HCR is a feasible method for the treatment of multi-vessel revascularization involving right coronary artery. Minimally coronary revascularization with BITA is associated with superior long-term graft patency and it's recommended for patients who could not tolerate dual-antiplatelet therapy. This study shows that both minimally invasive surgical approaches are safe and effective for treatment of patients with multi-vessel coronary artery disease.

[Surgical strategies for treatment of T1b gallbladder cancers diagnosed intraoperatively or postoperatively]

OBJECTIVE

To explore the surgical strategies for the treatment of T1b gallbladder cancer patients diagnosed intraoperatively or postoperatively.

METHODS

A retrospective analysis of 42 patients with T1b gallbladder cancers was performed. There were 14 patients diagnosed intraoperatively and 28 patients diagnosed postoperatively. The reevaluations of T stages were conducted in the 28 T1b gallbladder cancer patients diagnosed postoperatively by the professional pathologist. After T stage reevaluation, 25 confirmed T1b patients with complete follow-up data were divided into simple cholecystectomy group and ra-dical resection group, and the clinicopathologic characteristics between the two groups were analyzed.

RESULTS

Only 2 of the 14 T1b gallbladder cancer patients diagnosed by the intraoperative frozen specimen proved to be T1b on postoperative paraffin pathology, and for the remaining 13 patients, T2 was in 11 patients, and T3 in one patient. The rate of misdiagnosis was 85.7% by the intraoperative frozen specimens, postoperative T stages were equal or higher than intraoperative T stages. Two of the 28 postoperatively diagnosed T1b patients were proved to be T2 after reevaluation, the rate of misdiagnosis was 7.1%, the reevaluated T stages were equal to or higher than the previous stages. Twenty-five confirmed T1b gallbladder cancer patients had complete follow-up data, 11 of whom underwent simple cholecystectomy and the remaining 14 radical resections. No patient had vessel or perineural invasion on pathology in the 25 confirmed T1b patients. Metastasis was absent in all the 30 lymph nodes examined, which achieved from 14 patients with radical resection. The survival rate after simple cholecystectomy was comparable to that after radical resection (P=0.361). Only one patient with radical resection had abdominal cavity implantation relapse, who received gallbladder compression during operation and 2 years later died from metastasis.

CONCLUSION

Intraoperatively diagnosed T1b gallbladder cancer should receive radical resection. Reevaluation of the T stage is necessary and the initial step for postoperative diagnosed T1b gallbladder cancer patients. The pros and cons of radical surgery for definitive T1b patients should be carefully evaluated, and systemic chemotherapy is recommended for those with bile spillover.

[Dissemination of insertion sequence common regions 1 and int1 gene and drug resistance of 483 Escherichia coli and Klebsiella pneumonia broiler isolates]

Objective: To investigate and analyze distribution characteristics of two multidrug resistance related genes in broiler isolates in Shandong province. Methods: The pre slaughter broilers were chosen from Shandong province in this study in June, 2014. A total of 400 fecal samples from five different zones (east, south, west, north and middle) of the hen house were collected. 373(77.2%) Escherichia coli and 110 (22.8%) Klebsiella pneumonia strains were isolated, and ISCR1 and int1 gene were detected by PCR assay and sequencing. The resistance to 10 drugs belonging to 8 classes antimicrobial drugs were obtained by using minimal broth dilution method and data analysis. The difference between isolates and drug resistance profiles was analyzed. Results: Among 483 isolates, 440 isolates (91.1%), 126 isolates (26.1%) and 126 isolates (26.1%) were detected as int1, ISCR1 and both two gene carriers, respectively. The rate of 37 E. coli isolates not carried ISCR1 or int1 gene resistant to 0 to 2, 3 to 5, 6 to 8 classes antimicrobial agents was 13.5% (n=5), 78.4% (n=29), and 8.1% (n=3), respectively; the rate of 288 only int1 gene E. coli carriers resistant to 0 to 2, 3 to 5, 6 to 8 groups antimicrobial agents was 2.4% (n=7), 74.7% (n=215), and 22.9% (n=6), respectively. The data above showed significant difference (P<0.001). The rate of 26 only int1 gene K. pneumonia carriers resistant to 0 to 2, 3 to 5, 6 to 8 classes antimicrobial agents was 11.5% (n=3), 76.9% (n=20), and 11.5% (n=3), respectively; the rate of 78 both two gene K. pneumonia carriers resistant to0 to 2, 3 to 5, 6 to 8 groups antimicrobial agents was 0, 35.9% (n=28), and 64.1% (n=50), respectively. The data above showed significant difference (P<0.001). Conclusion: Gene int1 and ISCR1 showed high prevalence in E. coli and K. pneumonia isolates. High level multi-drug resistance profile could be mediated by int1 and ISCR1 gene co-existence.

Propranolol inhibits the proliferation, migration and tube formation of hemangioma cells through HIF-1α dependent mechanisms

The aim of this study was to investigate the mechanism of propranolol on the regression of hemangiomas. Propranolol-treated hemangioma tissues were collected and the expression of hypoxia inducible factor-1α (HIF-1α) was examined. We also established HIF-1α overexpression and knockdown hemangioma cells, and determined the effects of HIF-1α on the hemangioma cells proliferation, apoptosis, migration and tube formation. Significantly increased HIF-1α level was found in the hemangioma tissues compared to that in normal vascular tissues, whereas propranolol treatment decreased the HIF-1α level in hemangioma tissues in a time- and dose-dependent manner. Moreover, propranolol treatment significantly decreased cell proliferation, migration and tube formation as well as promoted cell apoptosis in HIF-1α overexpression and knockdown hemangioma cells. Propranolol suppressed the cells proliferation, migration and tube formation of hemangioma cells through HIF-1α dependent mechanisms. HIF-1α could serve as a novel target in the treatment of hemangiomas.

[Association between the types of obesity and the 10-year-coronary heart disease risk, in Tibet Autonomous Region and Xinjiang Uygur Autonomous Region]

Objective: To investigate the association between types of obesity and the 10-year-coronary heart disease risk in Tibet and Xinjiang of China. Methods: Using the multi-stage random sampling method, 7 631 participants aged 35 or older were examined under the International Standardized Examination process but with only 5 802 were eligible for analysis, in the 2015-2016 season. Results: The prevalence rates of general obesity, central obesity, visceral obesity and compound obesity were 0.53%, 12.62%, 10.08% and 42.35%, respectively. Out of all the compound obesity cases, 58.65% (1 441/2 457) of them appeared as having all types of obesity in our study. Risk related to the 10-year-coronary heart disease was higher in men than in women [(3.05±4.14)% vs. (1.42±2.37) %, P<0.000 1. Compound obesity (30.16%) showed the highest proportion on the risk of 10-year-coronary heart disease than central obesity (28.01%), visceral obesity (18.46%) or the general obesity (19.35%). After adjustment for confounding factors, results from the multivariate analysis showed the risk in compound obesity was higher than central obesity, visceral obesity or general obesity and was associated with the highest risk on the 10-year-coronary heart disease (OR=2.889, 95%CI: 2.525-3.305). People with anomalous BMI and WC seemed to have had the higher risk (OR=3.168, 95%CI: 2.730-3.677). Conclusions: Obesity was popular in the residents of Tibet and Xinjiang areas of China. Men and people with compound obesity (especially both BMI and WC were abnormal) seemed to carry greater risk on the 10-year-coronary heart disease.

[Sero-epidemiological survey on hepatitis B virus in Yunnan province, between 2006 and 2014]

Objective: Through two nationwide sero-epidemiological survey programs on hepatitis B virus (HBV), hepatitis B markers in Yunnan province were compared between the findings in 2014 and in 2006. Results were used to understand the HBV epidemic status in Yunnan province and to estimate the efficiency of measures on prevention and control of the disease. Methods: People at the age of 1-29 years were sampled from 6 counties of the National Disease Surveillance sites in Yunnan province, by multi-stage random sampling method. Demographic information was collected by questionnaire, and 2-4 ml serum sample was taken to detect HBsAg, anti-HBs, anti-HBc, HBeAg and anti-HBe, by ELISA method. Results: were logged-in the database and analyzed by SPSS 17.0. Results Between the two studies, no statistically significant differences were observed on the overall HBV infection rates and the positive rates of HBsAg, HBeAg, anti-HBe, anti-HBc. Positive rate of anti-HBs in 2014 was significantly higher than that in 2006. The main two combination profiles of hepatitis B markers were through the fifth model which was positive only for anti-HBs and the sixth model which was negative for all markers in 2006, and the same in 2014. Detection rate through the fifth profile in 2014 was significantly higher than the rate in 2006, while the detection rate of the sixth profile in 2014 was significantly lower than the one in 2006. When analyzing the differences in the same age group, between the two surveys, results showed that the positive rate of anti-HBs in 2014 was significantly higher than that in 2006, in both the10-14 and the 15-19 years-old groups. Positive rate of anti-HBc in the 20-29 year-olds in 2014 was significantly lower than the one of 2006. The positive rates of HBsAg in the age groups of 1-4, 5-14 and 15-29 were 1.12%,1.61% and 1.25% respectively, in 2014. Conclusion: Prevention and control measures on HBV seemed in great progres. However, more effective prevention and control measures should be taken continually among people under the age of 15, in Yunnan province.

[Association between body fat percentage, visceral fat index and cardiometabolic risk factor clustering among population aged 35 year old or over, in Tibet Autonomous Region and Xinjiang Uygur Autonomous Region]

Objective: To investigate the association between body fat percentage (BFP), visceral fat index (VFI) and Cardiometabolic Risk Factor Clustering (CRFC), among population aged 35 or older in Tibet and Xinjiang areas. Methods: Using the stratified multi-stage random sampling method, 7 571 residents aged 35 or above were examined with international standardized examination between 2015 and 2016. Of the eligible 5 643 participants, association of BFP and VFI with CRFC was defined as having two or more of the four risk factors: hypertension, diabetes mellitus, high TG and low HDL-C, at the same time. Logistic regression analysis and receiver operating characteristic (ROC) curve analysis were employed to further explore the relationships. Results: The overall prevalence of CRFC among aged 35 and older population in Tibet and Xinjiang areas was 9.78%. BFP and VFI were divided into four groups by quartile. After adjustment for age, gender, race, cigarette smoking, alcohol consumption, education attainments, and altitude of residence, ORs of CRFC seemed to have increased with BFP and VFI. Compared with people having BFP of 5.0%-27.0%, the OR(95% CI) were 1.15(0.86-1.54), 1.48(1.05-2.07) and 1.72(1.10-2.68) for the ones who presented 27.1%-31.7%, 31.8%-36.6% and 36.7%-50.0% of BFP. Compared to people of having 1-6 of VFI, with OR (95%CI) as 1.20(0.81-1.79), 1.91(1.30-2.80) and 3.91(2.64-5.77) for the ones having 7-9, 10-13 and 14-30 of VFI. Areas under the curve (AUC) of CRFC appeared as 0.55 for BFP and 0.70 for VFI, respectively, with statistically significant difference (P<0.01). Conclusion: Both BFP and VFI levels were closely associated with CRFC while VFI seemed to have a better predictive value than the BFP.

[Correlation between the clinical symptoms and the activation pattern of brain neurons in patients with obsessive-compulsive disorder]

Objective: To explore the correlation between clinical symptoms of patients with obsessive-compulsive disorder (OCD) and the activation pattern of brain neurons at resting. Methods: A total of 26 patients diagnosed with fist-episode OCD were selected and underwent functional magnetic resonance imaging (fMRI) scanning at resting state. The fMRI data were processed by statistical parametric mapping (SPM8), Data Processing Assistant for Resting-State fMRI Analysis Toolkit (DPARSFA), and Resting State fMRI Data Analysis Toolkit (REST) software. With age as concomitant variable, Pearson Correlation Analysis was adopted to study the correlation between clinical symptoms (obsessive thoughts and compulsive behavior) of patients and their regional homogeneity ( ReHo) values of whole brain. Results: The positive correlation between obsessive thoughts score of patients with OCD and ReHo value lied in insular_L, insular_R, cerebellum_L, cerebellum_R, calcarine_L, cuneus_L. The negative correlation between obsessive thoughts score of patients with OCD and ReHo value lied in thalamus_L, precuneus_L, caudate_L, cingulum_R, frontal_R. The positive correlation between compulsive behavior score of patients with OCD and ReHo value lied in temporal_L, frontal_inf_orb_l, frontal_inf_orb_R, frontal_mid_L, precentral_R. The negative correlation between compulsive behavior score of patients with OCD and ReHo value lied in cingulum-L, cingulum-R, caudate_L. Conclusion: Different obsessive-compulsive symptoms has different image foundation, and the dysfunction of cingulate has a major impact on the incidence of both obsessive thoughts and compulsive behavior of OCD patients.

A large randomised controlled intervention trial to prevent gastric cancer by eradication of Helicobacter pylori in Linqu County, China: baseline results and factors affecting the eradication

OBJECTIVE

To clarify the full range of benefits and adverse consequences of Helicobacter pylori eradication as a strategy for gastric cancer prevention, the community-based intervention trial was launched in Linqu County, China.

DESIGN

A total of 184,786 residents aged 25-54 years were enrolled in this trial and received (13)C-urea breath test. H. pylori positive participants were assigned into two groups, either receiving a 10-day quadruple anti-H. pylori treatment or lookalike placebos together with a single dosage of omeprazole and bismuth.

RESULTS

The prevalence of H. pylori in trial participants was 57.6%. A total of 94,101 subjects completed the treatment. The overall H. pylori eradication rate was 72.9% in the active group. Gender, body mass index, history of stomach disease, baseline delta over baseline-value of (13)C-urea breath test, missed medication doses, smoking and drinking were independent predictors of eradication failure. The missed doses and high baseline delta over baseline-value were important contributors in men and women (all Ptrend<0.001). However, a dose-response relationship between failure rate and smoking or drinking index was found in men (all Ptrend<0.001), while high body mass index (Ptrend<0.001) and history of stomach disease were significant predictors in women. The treatment failure rate increased up to 48.8% (OR 2.87, 95% CI 2.24 to 3.68) in men and 39.4% (OR 2.67, 95% CI 1.61 to 4.42) in women with multiple factors combined.

CONCLUSIONS

This large community-based intervention trial to eradicate H. pylori is feasible and acceptable. The findings of this trial lead to a distinct evaluation of factors influencing eradication that should be generally considered for future eradication therapies.

TRIAL REGISTRATION NUMBER

ChiCTR-TRC-10000979 in accordance with WHO ICTRP requirements.

Clinical research on dendritic cell vaccines to prevent postoperative recurrence and metastasis of liver cancer

We aimed to evaluate dendritic cell (DC) tumor vaccines for preventing liver cancer recurrence and metastasis. DCs were induced from mononuclear cells in the peripheral blood with recombinant human granulocyte macrophage colony stimulating factor (rhGM-CSF) and recombinant human interleukin 4 (rhIL-4), followed by sensitization with lysis of autologous liver cancer cells. One hundred and sixty patients with hepatocellular carcinoma were randomly divided into two groups of 80. One group was treated postoperatively with six cycles of the DC tumor vaccine. The other group was treated postoperatively with six cycles of FOLFOX 6, beginning 1 week after surgery. After treatment with DC tumor vaccines, the levels of CD3+, CD4+, and CD8+, the ratio of CD4+ to CD8+ DC, and the serum levels of IL-12 and IFN-γ were significantly increased both in comparison to the pre-treatment levels (P < 0.001) and to the chemotherapy group (P < 0.001). After a postoperative follow-up of 18 months, the metastatic recurrence rate in the DC tumor vaccine group was significantly lower than that in the chemotherapy group (17.50 vs 48.75%, P < 0.005), and the survival rate of the patients in the DC tumor vaccine group was higher than that of the chemotherapy treatment group (86.25 vs 52.50%, P < 0.005). Treatment with DC tumor vaccines was safe and feasible. It can enhance the immunity of the patients, reduce the rates of metastasis and recurrence, and improve survival rates. This is a promising treatment for the prevention of postoperative recurrence in patients with liver cancer.

Influences of species mixture on biomass of Masson pine (Pinus massoniana Lamb) forests

The effect of tree diversity on productivity in subtropical forests in China is poorly understood. We investigated the biomasses of trees, understory vegetation, coarse roots, and fine roots with varying proportions of Pinus massoniana, mixed with other tree species in stands of the same age, to examine the effects of tree diversity. With an increase of P. massoniana proportion, the tree and understory biomasses increased at first, and then gradually decreased. As expected, the biomass of fine roots decreased with soil depth. Stands with 40 to 60% P. massoniana had the highest biomass, whereas stands with <20% P. massoniana had the least biomass. Stands with <20% P. massoniana had the least understory biomass, whereas those with 20 to 40% Masson pine had the least fine root biomass.

Highly efficient dissociation of oxygen from hemoglobin in Tibetan chicken embryos compared with lowland chicken embryos incubated in hypoxia

Oxygen is one of the critical determinants for normal embryonic and fetal development. In avian embryos, lack of oxygen will lead to high fetal mortality, heteroplasia, and cardiovascular dysfunction. Tibetan chicken is a breed native to Tibet that could survive and keep higher hatchability regardless of negative effects of hypoxia. Generally, adaptive animals in high altitudes are characterized by higher hemoglobin concentrations and oxygen affinity. In the present study, the capacity of oxygen supply in late chick embryo (including d 17, 19, and 21) was compared between Tibetan chicken and a lowland breed, Dwarf White chicken, by determining the hemoglobin concentrations and oxygen equilibrium curves in both hypoxic (13% O(2)) and normoxic (21% O(2)) conditions. The results showed that a higher level of hemoglobin concentration was induced by hypoxia in Tibetan chicken embryos, and the hemoglobin could perform with better cooperativity and deliver oxygen to tissues more easily. Further investigation revealed that the carbonic anhydrase II mRNA in red blood cells of Tibetan chicken was increasingly induced to a higher level in hypoxia than that of the lowland breed. These results suggested that the stronger capacity of oxygen dissociation was an important characteristic of Tibetan chicken embryo to survive in hypoxia and the upregulating mode of carbonic anhydrase II mRNA might assist this dissociation. Therefore, for avian at high altitudes, the efficient dissociation of oxygen might reveal another aspect associated with the hypoxia adaptability.

hMan2c1 transgene promotes tumor progress in mice

In order to study the biological significance of alpha-mannosidase Man2c1, hMan2c1 transgenic mice were developed. In 113 F0 mice, eight were found to be genomic PCR positive for hMan2c1; 9/20 (45%) F1 mice, 16/21 (76.2%) F2 mice, and 12/14 (85.7%) F3 mice were genomic PCR positive for hMan2c1. RT-PCR demonstrated hMan2c1 mRNA transcription in four of eight transgenic lines. Enzymatic activity on p-nitrophenyl-alpha-D: -mannopyranoside was enhanced in 35# and 54# transgenic mice and real-time RT-PCR showed hMan2c1 mRNA expression in these mice. Reduced Con A binding to splenocytes implied N-glycosylation modification of host proteins by hMan2c1 transgene. hMan2c1 transgene promoted growth, invasion, and metastasis to lung of implanted hepatoma H22 and sarcoma S180. The average weights of H22 and S180 tumors were 3.98 +/- 1.62, 3.29 +/- 0.76, 1.69 +/- 1.09, and 3.19 +/- 0.44, 2.72 +/- 1.38, 0.97 +/- 0.41 g for 35#, 54# transgenic mice and wild type mice (W), respectively, (35# or 54# versus W, paired t-test, P < 0.05). In 35# and 54# mice 5/10 and 3/10 showed lung metastasis of H22 tumor in contrast with 1/10 in W mice. In 35# and 54# mice 1/6 and 2/6 showed lung metastasis of S180 tumor in contrast with 0/6 in W mice. The possible mechanism of the promotion was explored on both humoral and cellular immunity. Reduced antibody response to BSA was observed in transgenic mice, suggesting that specific antibody response to tumor antigens might be suppressed by hMan2c1 transgene. However, NK cytotoxicity in splenocytes was not affected by the transgene.

Two new mutations in the keratin 4 gene causing oral white sponge nevus in Chinese family

OBJECTIVE

We investigated white sponge nevus (WSN) in a Chinese family, and tried to find new mutation and demonstrated that this mutation is the causative mutation for WSN in this family and this condition affects a functionally important segment of the keratin 4 protein.

MATERIALS AND METHODS

We studied the affected family with the 32-year-old female patient, her mother, her younger sister and her daughter. Pathologic examinations were performed. DNA was extracted from peripheral blood lymphocytes, K4 and K13 genes were amplified by polymerase chain reaction (PCR) and sequenced.

RESULTS

Direct sequencing of PCR products revealed two new mutations in the keratin 4 gene, the heterozygous missense mutation 1829G-->A in exon 2B, and 2324A-->G in non-coding region. No any mutation was found in the keratin 13 gene.

CONCLUSIONS

We found two new mutations in the keratin 4, which may be related with the development of WSN.

FK506 in the treatment of children with nephrotic syndrome of different pathological types

OBJECTIVE

To evaluate the efficacy of FK506 in the treatment of children with nephrotic syndrome of different underlying pathology.

METHODS

12 patients were treated with FK506 with a dosage of 0.1 - 0.15 mg/kg/d while corticosteroid dose was tapered stepwise. This therapeutic course lasted 3 - 6 months during which the plasma concentration ofFK506 was monitored.

RESULTS

12 children with different pathological types nephrotic syndrome were treated with FK506, including 4 cases of MCN, 6 cases of MsPGN, and 1 case of MPGN and 1 case of FSGS. After 2-month duration, 8 patients got complete remission including 4 cases of MCN and 4 cases of MsPGN and 3 children including 1 case of MsPGN, 1 case of MPGN, and 1 case of FSGS got partial remission. Only 1 child with MsPGN was considered to be a treatment failure. The overall response rate was 91.67% with the plasma concentration of FK506 maintained at 5 approximately 12 ng/ml, and the response time was 10 - 38 days. After 1-month duration, all patients except one experienced a reduction in proteinuria to normal levels or a partial response (50% reduction in protein excretion), significant increase in serum albumin, decrease in serum cholesterol and triglyceride and disappearance of edema. 2 months later, in 11 patients, blood biochemical values had returned to normal levels. The drug was generally well-tolerated. 3 patients had anorexia, nausea, vomiting. 2 patients experienced transient elevated serum creatinine which was reversible after the adjustment of dosage. 3 patients had minor changes in urine NAG. Only 2 of all patients relapsed.

CONCLUSION

FK506 is one of the effective immunosuppressants. In this study, FK506 in combination with a small doses of steroid while decreasing FK506 dosage plays a role in consolidating the curative effect and preventing relapse. In conclusion, FK506 may be effective in the treatment of nephrotic syndrome.

Simulation study of the effects of hypovolaemia on cardiovascular response to orthostatic stress

To investigate the role played by hypovolaemia in the mechanism of orthostatic intolerance, a mathematical model was developed. The model consisted of seven sub-models that describe: the redistribution of blood induced by lower body negative pressure (LBNP); filling of the left ventricle; contracting of the left ventricle; interaction between the left ventricle and peripheral circulation; and baroreflex regulation. The model was evaluated using experimental data. Using the model, computer simulations were performed to investigate the effects of hypovolaemia on the cardiovascular response to LBNP. The simulation results indicated that, first, when the blood loss is less than 5%, blood pressure can be maintained in the normal range by the baroreflex regulatory mechanism, even with high LBNP application; secondly, when the blood loss is between 15 and 20%, heart rate and blood pressure can be kept in the normal range if LBNP is not applied, but blood pressure falls sharply with LBNP application; and, thirdly, when the blood loss is 25%, the cardiovascular system is in an unstable state (heart rate: 116 beat min (-1), systolic blood pressure: 97 mmHg; diastolic blood pressure: 77 mmHg), even without any LBNP, and becomes more unstable with LBNP. The simulation results support the hypothesis that hypovolaemia is a cause of orthostatic intolerance.

[Daily 1 h standing can prevent depression of myocardial contractility in simulated weightless rats]

Objective. To observe and compare the effect of daily standing of rats for different durations in alleviating the depression of myocardial contractility induced by simulated weightlessness. Method. Fifty male Sprague-Dawley rats were randomly assigned to five groups: simultaneous control (CON), four-week tail-suspension (SUS), SUS plus daily 1 h standing (STD1), SUS plus daily 2 h standing (STD2) and SUS plus daily 4 h standing (STD4). Four weeks later, wet weights of the left soleus, testis and adrenal gland were measured, and the isometric contractile tension and its time parameters of isolated perfused papillary muscles from rats of various groups were examined. Result. Compared with CON, the wet weights of testis in different treatment groups decreased significantly (P<0.05). The wet weight of soleus in SUS decreased by 58.9% (P<0.01); but in STD1, STD2 and STD4, decreased by 38.5%, 24.0% and 11.0% (P<0.01, or P<0.05) respectively. The relative protections were 34.7%, 59.2% and 81.4% (P<0.01) respectively. In SUS group, developed tension (DT), peak rate of tension rise (+dT/dtmax) and peak rate of tension fall (-dT/dtmax) decreased by 32.2%, 29.2% and 30.7% (P<0.05), and time to peak rate of tension rise (TPP) and time to peak tension (TPT) prolonged by 21.2% and 11.0% (P<0.05), respectively. Whereas in STD1, STD2 and STD4, all the parameters reflecting myocardial contractility (like DT, + dT/dtmax, -dT/dtmax and TPP), did not show any significant change as compared with those of CON. However, being an exception, TPT still showed obvious prolongation (P<0.05) in STD1. Conclusion. Daily 1 h standing could prevent depression of myocardial contractility in rat induced by medium-term simulated weightlessness. However, with respect to prevention of atrophic changes in soleus muscle and testis, daily standing for 1 h, 2 h, or 4 h was only partially effective and even totally devoid of any effect, respectively.

Vascular adaptation to microgravity: what have we learned?

Findings from recent bed rest and spaceflight human studies have indicated that the inability to adequately elevate the peripheral resistance and the altered autoregulation of cerebral vasculature are important factors in postflight orthostatic intolerance. Animal studies with rat model have revealed that simulated microgravity may induce upward and downward regulations in the structure, function, and innervation of the cerebral and hindquarter vessels. These findings substantiate in general the hypothesis that microgravity-induced redistribution of transmural pressures and flows across and within the arterial vasculature may well initiate differential adaptations of vessels in different anatomic regions. Understanding of the mechanisms involved in vascular adaptation to microgravity is also important for the development of multisystem countermeasures. However, future studies will be required to further ascertain the peripheral effector mechanism of postflight cardiovascular dysfunction.

[Effects of intermittent artificial gravity on femur of simulated weightlessness rats]

AIM

To explore the effects of three intermittent artificial gravity on simulated weightlessness rats.

METHODS

30 male SD rats were divided into 5 groups: control group (C), tail-suspension group (S) and standing group (G1), 1.5 G group (G2), 2.6 G (G3) group; randomly and equally. G groups were given 1 h/d standing, 1.5 G or 2.6 G artificial gravity each day. The effects of 3 weeks artificial gravity on tail-suspension rats were evaluated by measuring physical and mechanical parameters of femur.

RESULTS

Compared to S rats, elastic ultimate load (EUL), the ultimate load (UL) and bending rigidity coefficient (BRC) of G1 rats (P < 0.05) improved significantly; Diameter (P < 0.01), mass (dry) and density (P < 0.05), EUL and UL (P < 0.05) of G2 rats raised significantly; EUL and UL of G3 rats (P < 0.01) improved markedly.

CONCLUSION

By using intermittent artificial gravity, the mechanical parameters of weight loading bones of simulated weightlessness rats were all improved apparently, and the one using 1.5 G 1 h/d artificial gravity was the best.

Do thinking styles contribute to academic achievement beyond self-rated abilities?

This research identifies individual differences in academic achievement attributable to thinking styles over and above what can be explained by self-rated abilities. Participants were 209 university students from Hong Kong and 215 university students from mainland China. Participants responded to the Thinking Styles Inventory (Chinese version) that is based on Sternberg's theory of mental self-government (R. J. Sternberg, 1988). They also rated their own analytical, creative, and practical abilities on a 10-point scale based on R. J. Sternberg's (1985) triarchic theory of human intelligence. Participants' academic achievement scores were also used. The prediction that thinking styles statistically predict academic achievement was supported by data from both Hong Kong and mainland China. Academic achievement and thinking styles are related differently in the two groups. Implications of these findings for both teaching and research are discussed.

[Counter-effect of intermittent +Gz exposures on vasoreactivity in decline in hind body arteries of rats under simulated weightlessness]

Objective. To investigate the counter-effect of intermittent artificial gravity, the present study examined vasoreactivity changes of femoral and mesenteric arteries in rats subjected to simulated weightlessness plus standing or centrifugation. Method. Forty male Sprague-Dawley rats were divided into simultaneous control (CON), simulated weightlessness (SUS), simulated weightlessness plus 1 h standing (STD1), simulated weightlessness plus 1.5 G centrifugation (1.5 G), and simulated weightlessness plus 2.6 G centrifugation (2.6 G) groups. Responses of arteries to vasoconstrictor were examined in vitro using isolated femoral and mesenteric arterial rings. Result. The contractile responsiveness to KCl or PE of femoral and mesenteric arterial rings isolated from SUS significantly decreased as compared with CON. And those of STD1 and the two centrifuged groups significantly enhanced as compared with that of SUS. Whereas there was no difference among STD1, 1.5 G, 2.6 G and CON. Conclusion. Simulated weightlessness may result in decreased contractile responses to KCl and PE of rat femoral and mesenteric arteries. Both STD1, 1.5 G, and 2.6 G prevented the decrease of contractile response to KCl and PE of femoral arteries.

Approaches and thinking styles in teaching

In this study, the author examined the relationship between teaching approaches and thinking styles in teaching. The study parallels previous investigations (Zhang, 2000a, 2000b; Zhang & Sternberg, 2000) of students' learning approaches and thinking styles in learning. Seventy-six in-service teachers from Hong Kong responded to the Approaches to Teaching Inventory (K. Trigwell & M. Prosser, 1996) and the Thinking Styles Inventory in Teaching (E. L. Grigorenko & R. J. Sternberg, 1993) as well as to a range of questions designed to assess the participants' perceptions about their work environment. It was concluded that approach and style are two overlapping constructs with different labels. The differences between approach and style are in degree, but not in kind.