[Influencing factors of iron metabolism assessment in patients with myelodysplastic syndrome: A retrospective study]

Objective: To analyze the influencing factors of iron metabolism assessment in patients with myelodysplastic syndrome. Methods: MRI and/or DECT were used to detect liver and cardiac iron content in 181 patients with MDS, among whom, 41 received regular iron chelation therapy during two examinations. The adjusted ferritin (ASF) , erythropoietin (EPO) , cardiac function, liver transaminase, hepatitis antibody, and peripheral blood T cell polarization were detected and the results of myelofibrosis, splenomegaly, and cyclosporine were collected and comparative analyzed in patients. Results: We observed a positive correlation between liver iron concentration and ASF both in the MRI group and DECT groups (r=0.512 and 0.606, respectively, P<0.001) , only a weak correlation between the heart iron concentration and ASF in the MRI group (r=0.303, P<0.001) , and no significant correlation between cardiac iron concentration and ASF in the DECT group (r=0.231, P=0.053) . Moreover, transfusion dependence in liver and cardiac [MRI group was significantly associated with the concentration of iron in: LIC: (28.370±10.706) mg/g vs (7.593±3.508) mg/g, t=24.30, P<0.001; MIC: 1.81 vs 0.95, z=2.625, P<0.05; DECT group: liver VIC: (4.269±1.258) g/L vs (1.078±0.383) g/L, t=23.14, P<0.001: cardiac VIC: 1.69 vs 0.68, z=3.142, P<0.05]. The concentration of EPO in the severe iron overload group was significantly higher than that in the mild to moderate iron overload group and normal group (P<0.001) . Compared to the low-risk MDS group, the liver iron concentration in patients with MDS with cyclic sideroblasts (MDS-RS) was significantly elevated [DECT group: 3.80 (1.97, 5.51) g/L vs 1.66 (0.67, 2.94) g/L, P=0.004; MRI group: 13.7 (8.1,29.1) mg/g vs 11.6 (7.1,21.1) mg/g, P=0.032]. Factors including age, bone marrow fibrosis, splenomegaly, T cell polarization, use of cyclosporine A, liver aminotransferase, and hepatitis antibody positive had no obvious effect on iron metabolism. Conclusion: There was a positive correlation between liver iron concentration and ASF in patients with MDS, whereas there was no significant correlation between cardiac iron concentration and ASF. Iron metabolism was affected by transfusion dependence, EPO concentration, and RS.

[Analysis of early and middle stage efficacy and complications of oblique lumbar interbody fusion in treating degenerative lumbar diseases]

OBJECTIVE

To investigate the early and middle stage efficacy and complications of minimally invasive extraperitoneal oblique lumbar interbody fusion (OLIF) in the treatment of degenerative lumbar diseases.

METHODS

The clinical data of 22 patients with degenerative lumbar diseases underwent OLIF from October 2017 to March 2019 were retrospectively analyzed, including 14 males and 8 females, aged from 51 to 72 years with an average of (63.15±7.22) years. There were 6 cases of lumbar spinal stenosis, 5 cases of lumbar spondylolisthesis, 4 cases of adjacent vertebral disease, 3 cases of degenerative lumbar scoliosis, 3 cases of discogenic low back pain, and 1 case of recurrence after posterior lumbar decompression. Posterior minimally invasive pedicle screw fixation was performed in 13 cases and Stand-alone fixation in 9 cases. Intraoperative blood loss, operation time, postoperative drainage volume, landing time were recorded. The intervertebral disc height(IDH), intervertebral foramen height(IFH), intervertebral foramen area( IFA), canal diameter(CD), canal area(CA) were measured before and after operation. The imaging changes (including location of fusion cage, interbody fusion, and cage subsidence) and complications were observed. Oswestry Disability Index (ODI), numerical rating scales (NRS) and Japanese Orthopaedic Association (JOA) scores were compared before and 3, 6, 12 months after operation.

RESULTS

All 22 patients successfully completed the operation. The intraoperative blood loss was 25 to 280 ml with an average of (95.45±79.07) ml and that of simple anterior approach was 25 to 70 ml with an average of (45.71±15.42) ml. The operation time was 75 to 210 min with an average of (137.72±37.66) min, and the simple anterior operation time was 75 to 105 min with an average of (91.40±15.96) min. The total drainage volume was 10 to 110 ml with an average of (56.23±31.15) ml, and the time to go down to the ground was 24 to 72 hours (54.48±18.24) hours after operation. Postoperative IDH improved (6.63±2.61)mm(P<0.05), the IFH improved (5.35±2.47)mm (P<0.05), the IFA improved (97.67±33.58)mm²(P<0.05), the CD improved (3.31±1.61) mm(P<0.05), the CA improved (57.52±31.39) mm²(P<0.05). Five patients got interbody fusion at 6 months after operation and all 22 patients got interbody fusion at 12 months after operation. There was 5 cases of fusion cage subsidence, all of which occurred in the cases without posterior fixation(using Stand-alone fixation). There was no serious complication such as big blood vessel injury, ureter injury, dural sac injury and nerve root injury. Peritoneal injury occurred in 1 case, postoperative transient thigh pain, decrease of quadriceps femoris muscle strength in 4 cases and sympathetic nerve injury in 1 case. The symptoms of lumbago and radicular pain of lower extremities were alleviated obviously 3 days after operation. The ODI, NRS and JOA scores at 6, 12 months after operation were significantly improved(P<0.05).

CONCLUSION

The treatment of lumbar degenerative diseases with definite indications by OLIF can achieve satisfactory clinical results, and it has advantages of less intraoperative bleeding, fast time to land, less complications, good imaging improvement and indirect decompression. But the operation time and fluoroscopy time are longer in the early stage, and complications such as peritoneal injury and lumbar plexus over traction may occur. The long-term incidence of settlement of fusion cage with Stand-alone technology is higher.

Maxillary molar root and canal morphology of Neolithic and modern Chinese

OBJECTIVE

This study aimed to characterize Neolithic human maxillary molars from archeological remains at the Jiaojia site, Shandong, China, and compare their ultrastructural features with sex and age-matched modern locals.

DESIGN

Maxillary first (n = 86) and second (n = 80) molars in 5000-year-old individuals (n = 50) from the Jiaojia site were scanned by cone-beam computed tomography (CBCT). Sex and age-matched control groups were assigned from oral surgical patients at Shandong University. Images were analyzed for crown size, root length, root morphology, canal inter-orifice distances, mesiobuccal canal morphology, and second mesiobuccal (MB2) canal prevalence and location. Neolithic and modern values were compared statistically using Chi-squared and Mann-Whitney test at p < .05.

RESULTS

Crown and root size were smaller, and canal inter-orifice distances were shorter in Neolithic maxillary molars than their modern counterparts. For mesiobuccal roots, Weine's Type I single canals were the most prevalent in Neolithic and modern first and second molars. MB2 canal prevalence were not significantly different (p > .05) in Neolithic (53.3%) or modern (60.5%) first molars, and Neolithic (11.3%) or modern (21.3%) second molars. But, MB2 prevalence was significantly higher for modern than ancient male first (p = .032) and second (p = .005) molars. Additionally, MB2 were located more mesially and closer to MB1 in Neolithic than modern molars.

CONCLUSIONS

Maxillary molar root and canal morphology of ancient 5000-year-old remains at the Jiaojia site resemble that of local patients. A trend towards larger tooth size, and more dispersed MB2 canals over this short evolutionary period warrants additional investigation.

[COVID-19 epidemic and its characteristics in Heilongjiang province]

Objective: To describe the COVID-19 epidemic and its characteristics in Heilongjiang province, and provide evidence for the further prevention and control of COVID-19 in the province. Methods: The information of COVID-19 cases and clusters were collected from national notifiable disease report system and management information system for reporting public health emergencies of China CDC. The Software's of Excel 2010 and SPSS 23.0 were applied for data cleaning and statistical analysis on the population, time and area distributions of COVID-19 cases. Results: On January 22, 2020, the first confirmed case of COVID-19 was reported in Heilongjiang. By March 11, 2020, a total of 482 cases domestic case of COVID-19, The incidence rate was 1.28/100 000, the mortality rate was 2.70% (13/482) in 13 municipalities in Heilongjiang. There were 81 clusters of COVID-19, The number of confirmed cases accounted for 79.25% (382/482) of the total confirmed cases and 12 cases of deaths. The family clusters accounted for 86.42% (70/81). Compared with the sporadic cases, the mortality rate, proportion of elderly cases aged 60 or above and severe or critical cases of clinical classification were all higher in the clusters especially the family clusters, but the differences were not significant (P>0.05). There were 34 clusters involving more than 5 confirmed cases accounted for 41.98% (34/81) of the total clusters, the involved cases accounted for 68.31% (261/382) of the total cases of clusters. There were significant differences in age distribution of the cases among the case clusters with different case numbers. In the clusters involving 6-9 cases, the proportion of cases aged 65 years or above was more (26.53%, 39/147). Conclusions: The incidence rate of COVID-19 was relatively high and the early epidemic was serious in Heilongjiang, The number of cases was large in clusters especially family clusters.

Influence of body mass index on the clinicopathological features of 13,995 papillary thyroid tumors

PURPOSE

This retrospective study aimed to assess the association between obesity, gender, and specific clinicopathological features in patients with papillary thyroid cancer (PTC) and whether diagnostic ultrasonography (US) is adversely affected by obesity in these patients.

MATERIALS AND METHODS

This study retrospectively analyzed 13,995 adult patients with PTC from a single medical center in China. Data stratification was performed to assess the association of obesity with US features and aggressive clinicopathological features in different models according to the World Health Organization Body Mass Index (WHO-BMI) and Chinese BMI classification (CN-BMI). The odds ratio (OR) of malignant US features and aggressive clinicopathological features was calculated from binary logistic regression models.

RESULTS

The BMI, obesity ratio, malignant US features, and aggressive pathological characteristics of males were significantly higher than those of females. After adjusting for confounding factors, the association of obesity with malignant US features and aggressive pathological characteristics was found to be sex-dependent. Next, obesity (WHO-BMI) was found to have an "interfering effect" on the US assessment of PTC (OR = 0.754, 95% CI 0.609-0.932, P = 0.009) in women. Among both sexes, obesity (WHO-BMI) increased the risk of tumor size (OR_male = 1.539 and OR_female = 1.521) and multifocality (OR_male = 1.659 and OR_female = 1.449). However, obesity did not increase the risk of capsular invasion or tumor staging in males. The above results are consistent with the CN-BMI. In addition, age was found to have an "interfering effect" on the US evaluation of malignant nodules in both sexes.

CONCLUSION

The results of our study confirm that higher BMI is significantly associated with aggressive clinicopathological features of PTC. Gender differences were present with obesity ratios and aggressive clinicopathological features being significantly higher in men.

Downregulation of nuclear protein-1 induces cell cycle arrest in G0/G1 phase in glioma cells in vivo and in vitro via P27

Nuclear protein-1 (NUPR1), also named as p8 or Com1, has been since found overexpressed in several human malignant tumor cells, such as glioma. NUPR1 also regulates cell cycle progression, however, the role of NUPR1 in regulating glioma cell cycle remains poorly understood. Knockdown efficiency of U87 and U251 cells infected with the lentiviral vector was detected by quantitative real-time PCR and western blot in vitro and in vivo. Flow cytometry and western blot were used to explore a mechanism by which NUPR1 modulates cell cycle in U87 and U251 cells. Immunohistochemistry was applied to detect expression levels of P27, CDK2, and cyclin E in human glioma tissues with NUPR1 positive expression and tumorigenesis in nude mice. We confirmed that the downregulation of NUPR1 arrested the cell cycle in the G0/G1 phase in U87 and U251 cells in vitro. Furthermore, the expression level of P27 was increased, and CDK2 and cyclin E were decreased upon silencing NUPR1 expression in vitro and in vivo. In conclusion, the knockdown of NUPR1 induces cell cycle arrest in the G0/G1 phase in glioma cells via P27.

[Effect of different bone cement dispersion types in the treatment of osteoporotic vertebral compression fracture]

OBJECTIVE

To observe different bone cement dispersion types of PVP, PKP and manipulative reduction PVP and their effects in the treatment of senile osteoporotic vertebral compression fractures and the bone cement leakage rate.

METHODS

The clinical data of patients with osteoporotic vertebral compression fractures who underwent unilateral vertebroplasty from January 2012 to January 2015 was retrospectively analyzed. Of them, 56 cases including 22 males and 34 females aged from 60 to 78 years old were treated by PVP operation; Fouty-eight cases including 17 males and 31 females aged from 61 to 79 years old were treated by PKP operation; Forty-three cases including 15 males and 28 females aged from 60 to 76 years old were treated by manipulative reduction PVP operation. AP and lateral DR films were taken after the operation; the vertebral bone cement diffusion district area and mass district area were calculated with AutoCAD graphics processing software by AP and lateral DR picture, then ratio(K) of average diffusion area and mass area were calculated, defining K<50% as mass type, 50%<=K<=100% as mixed type and K>100% as diffusion type. Different bone cement dispersion types of PVP, PKP and manipulative reduction PVP operation were analyzed. According to bone cement dispersion types, patients were divided into diffusion type, mixed type and mass type groups.Visual analogue scale (VAS), vertebral body compression rate, JOA score and bone cement leakage rate were observed.

RESULTS

All patients were followed up for 12-24 months with an average of 17.2 months. There was significant difference in bone cement dispersion type among three groups (P<0.05). The constituent ratio of diffusion type, mixed type and mass type in PVP operation was 46.43%, 35.71%, 17.86%, in PKP was 16.67%, 37.50% , 45.83%, and in manipulative reduction PVP was 37.21%, 44.19% and 18.60%, respectively. PVP operation and manipulative reduction PVP were mainly composed of diffusion type and mixed type, while PKP was mainly composed of mass type and mixed type. There was no significant difference in VAS score, JOA score and bone cement leakage rate among three groups. There was statistically significant difference in postoperative vertebral body compression rate among three bone cement dispersion types(P<0.05), postoperative vertebral body compression rate in diffusion type group at 24 h postoperatively and final follow-up was (17.31±5.06)% and(18.58±4.91)%, respectively. In mixed type group, it was(14.21±5.15)% and(14.59±5.07)%, respectively. In mass type group, it was(13.89±5.02)% and(14.28±4.94)%, respectively.

CONCLUSIONS

Bone cement dispersion type is different in PVP, PKP and manipulative reduction PVP operation. The bone cement dispersion of mass type and mixed type to recovery of compressed vertebral body is better than diffusion type, and there is no obvious difference in clinical effect in different bone cement dispersion type early and middle term.

[Predict response to decitabine in patients with myelodysplastic syndrome and related neoplasms]

目的

探索预测骨髓增生异常综合征（MDS）及相关肿瘤地西他滨治疗反应的临床及分子学指标。

方法

回顾性分析109例接受地西他滨治疗的MDS及相关肿瘤患者临床资料，采用二代测序检测MDS常见突变基因的突变情况，分析患者临床特征及基因突变与地西他滨临床反应的关系。

结果

地西他滨中位疗程数为4（2~11）个，共74例（67.9%）患者获得治疗反应，其中30例（27.5%）获得完全缓解（CR）；35例（32.1%）患者无反应。单因素分析结果显示，国际预后积分系统（IPSS）中危2+高危、复杂核型、单体核型、7号染色体异常及1个疗程后PLT倍增的患者可获得更高的CR率。66.7%（14/21）的复杂核型患者、58.8%（10/17）的单体核型患者及66.7%（10/15）的TP53基因突变患者获得CR；TP53基因突变常合并复杂核型及单体核型；多因素分析显示TP53突变、1个疗程后PLT倍增及复杂核型是预测地西他滨治疗获得CR的独立预后因素，其中TP53突变是最强的预测因子（OR=4.39，95%CI 1.20~16.06，P=0.026）。

结论

TP53基因突变、1个疗程后PLT倍增及复杂核型可预测地西他滨完全缓解。

[Interaction between family history of diabetes and hyperlipidemia on risk of diabetes in population with normotension in Harbin: a cross-sectional study]

Objective: To explore the interaction between family history of diabetes and hyperlipidemia on the risk of diabetes in population with normotension. Methods: A multistage stratified probability random sampling was conducted to select a representative sample of urban residents aged 20-74 years in Harbin. A total of 376 diabetes patients with normotension and 3 692 residents with normal blood pressure, normal fasting glucose, and normal 2 hours glucose from OGTT were surveyed. The interaction was evaluated by using crossover analysis and additive model. Results: Multivariate logistic regression analysis indicated that there was a possible additive interaction between family history of diabetes and hyperlipidemia on the risk of diabetes. The relative excess risk due to the interaction, the attributable proportion due to the interaction, and the synergy index were 1.97 (95%CI:-0.32-4.26), 0.30 (95%CI: 0.03-0.57), and 1.54 (95%CI: 0.96-2.47), respectively. There were significant combination effects between family history of diabetes and high both total cholesterol and triglyceride, isolated high total cholesterol, and isolated high triglyceride levels; the ORs were 10.55 (95%CI: 5.62-19.80), 7.81 (95%CI: 3.65-16.71) and 5.13 (95%CI: 3.22-8.16), respectively. Conclusion: There might be synergistic effect between family history of diabetes and hyperlipidemia on the risk of diabetes in population with normotension.

[Clinical analysis of 34 cases with sepsis and systemic capillary leak syndrome]

Objective: To study the clinical characteristics of sepsis with systemic capillary leak syndrome(SCLS) and to evaluate the therapeutic effect and clinical significance of fluid therapy adjusted timely in these patients. Methods: The clinical data of 34 patients with sepsis and SCLS in the Department of Hepatobiliary Surgery ICU of General Hospital of People's Liberation Army General Hospital from July 2014 to January 2016 were retrospectively analyzed.There were 21 males and 13 females, aged from 21 to 74 years, with an average age of 56.3 years.Primary disease as follows: 18 cases with severe acute pancreatitis, 7 postoperative cases of subtotal hepatectomy, 5 postoperative cases of pancreatoduodenectomy, 4 postoperative cases of cholelithiasis.These patients were divided into survival group and death group according to their 28-day survival status.The clinical data including C-reactive protein(CRP), platelets (PLT), brain natriuretic peptide (BNP), the level of arterial blood lactic acid(LAC), oxygenation index(PaO₂/FiO₂, OI), net fluid balance(NFB) and norepinephrine dosage(NE) were collected and compared between two groups at three different intervals(day 1-3, day 4-6, day 7-9). The measurement data and numeration data were statistically analyzed with t test and χ² test respectively to explore the inherent characteristics of the disease evolution and its clinical significance. Results: The survival group (n=23)and the death group(n=11)had no significant difference in the characteristics of basic clinical characters.The condition of the survival group and the death group were both in progress in 1-3 days period manifested as increased CRP(t=-0.473, P=0.640) and BNP levels(t=0.140, P=0.895), decreased PLT counts(t=-0.505, P=0.620) in the inflammatory response, decreased LAC(t=-1.008, P=0.320) and OI level (t=-2.379, P=0.020)in tissue perfusion index, and positive fluid balance(NFB: t=0.910, P=0.370), required NE(t=-0.853, P=0.400) to maintain effective perfusion pressure with systemic edema in both groups.There was no significant difference of all these clinical parameters between the two groups.The patients' condition of the survival group reached a plateau phase, whereas all relative indicators of the death group implied significant aggravation and deterioration of systemic infection(CRP: t=-3.438, P=0.000; PLT: t=1.649, P=0.110; BNP: t=-10.612, P=0.000), tissue perfusion (LAC: t=-11.305, P=0.000; OI: t=2.743, P=0.010)and tissue edema NFB(t=-4.257, P=0.000) and NE(t=-7.956, P=0.000) in 4-6 days period.In the last 7-9 days period the patients' condition of the survival group took a turn for improvement, yet the condition of the death group continued to deteriorate, refractory septic shock developed and multiple organ dysfunction syndrome followed afterwards inevitably(CRP: t=-10.036, P=0.000; PLT: t=6.061, P=0.000; BNP: t=-10.119, P=0.000; LAC: t=-24.466, P=0.000; OI: t=13.443, P=0.010; NFB: t=-8.345, P=0.000; NE: t=-7.121, P=0.000). Conclusions: The condition of patient with sepsis and SCLS would be improved markedly at the critical turning point around 7-9 days period since the effective systemic treatment began.If the infection does not be significantly constrolled and SCLS still remains in a sustained extravasation period in 7-9 days, the prognosis of these patients may be worse and the mortality may be higher than that of the patients mentioned before.

[Understanding the risk factors for infectious diseases, their prevention, and control, among residents of Zhejiang Province]

Objective: To investigate the understanding of infectious diseases, their prevention, and control, and the factors influencing this literacy among urban and rural residents of Zhejiang Province. Methods: In November- December 2014, a multistage stratified cluster sampling questionnaire was administered at study sites in eight districts of Zhejiang province: Hangzhou city Gongshu district, Hangzhou city Chun'an county, Wenzhou city Cangnan county, Dongyang city, Jiaxing city Jiashan county, Zhoushan city Putuo district, Linhai city, Lishui city Jinyun county. The inclusion criteria were: 15-60 years old, living locally for more than six continuous months, and no mental illness. The exclusion criteria were: foreigner residing locally, resident of Hong Kong, Macau, or Taiwan, or unable to communicate through speech or writing. In this study, 4 091 questionnaires were distributed, and 4 020 valid questionnaires were returned(98.26%). Health literacy regarding infectious diseases was measured at five levels: knowledge, skills, behaviors, access to information, and understanding of the prevention of infectious diseases. A total score was calculated for each questionnaire, and a total score of ≥80 was deemed to indicate an understanding of the prevention of infectious diseases. A χ² test was used to compare the levels of health literacy in different populations with single-factor analyses, and a multivariate unconditional logistic regression model was used to analyze the factors affecting infectious diseases prevention and treatment literacy levels. Results: Of the 4 020 respondents(aged(43.84 ± 10.28)years), 1 964 were male(48.86%)and 2 056 were female(51.14%). In the total surveyed population, 15.17%(n=610)understood the prevention of infectious diseases, 294 were male(14.97%)and 316 were female(15.37%)(χ²=2.48, P=0.115). When the participants in the different age groups were analyzed, 23.11%, 20.29%, 13.27%, and 11.04% of those aged 18- 29(n=116), 30- 39(n= 166), 40- 49(n=178), and ≥50 years(n=150), respectively, understood infectious disease prevention(χ²= 63.16, P<0.001). When the participants were analyzed according to education, 46.01%, 24.86%, 12.03%, 5.27%, or 2.39% of those educated at university(n=167), at high school/vocational school/college(n=175), at middle school(n=215), at elementary school(n=46), or who were illiterate/slightly literate(n=7), respectively, understood infectious disease prevention(χ²=436.67, P<0.001). Among the urban(n=336)and rural participants(n=274), 18.98% and 12.18% understood infectious disease prevention, respectively(χ²= 35.57, P<0.001), so the urban residents had better health literacy than rural residents(OR=1.28, 95% CI= 1.06- 1.54), and those aged 18- 29 or 30- 39 years had even better health literacy than the rural residents(OR=1.39, 95%CI=1.01-1.91). When the health literacy levels of migrant workers were compared with those of agency/institutional personnel, business people, unemployed, and retirees, the OR(95% CI)values were 2.52(1.82-3.49), 1.69(1.24-2.30), 2.99(1.65-5.39), and 2.43(1.59-3.72), respectively. When the illiterate/slightly literate were compared with those educated at university, high school/vocational school/secondary school, and junior high school, the OR(95%CI)values were 35.11(15.73-78.36), 13.31(6.11-28.99), and 5.37(2.48-11.62), respectively. Conclusion: Limited levels of health literacy are common among the residents of Zhejiang Province. Lower education level, older age, and rural residence were predictors of low health literacy in this study.

Rehmannia glutinosa oligosaccharide induces differentiation of bone marrow mesenchymal stem cells into cardiomyocyte-like cells

The aim of this study was to observe the effect of Rehmannia glutinosa oligosaccharide (RGO) on differentiation of bone marrow mesenchymal stem cells (MSCs) into cardiomyocyte-like cells . Rat MSCs were isolated, treated, and grouped as follows: RGO treatment group, 5-azacytidine (5-aza) treatment group, RGO + 5-aza treatment group, and control group. Following a four-week induction period, cardiac troponin I (cTnI) levels in MSCs were quantified by chemiluminescence, and the levels of myocardial enzymes creatine kinase (CK) and creatine kinase isoenzyme-MB (CK-MB) were measured using a dry chemistry analyzer. The cTnI- and connexin 43 (Cx43)-positive MSC population was identified by immunofluorescence, and expression levels of cTnI and Cx43 were analyzed by western blots. Following induction, cTnI, CK, and CK-MB levels were significantly higher in the RGO + 5-aza group as compared with the RGO and 5-aza groups (P < 0.05). In addition, fluorescence intensity of cTnI and Cx43 was higher in the RGO + 5-aza group as compared with the RGO and 5-aza groups. No cTnI- or Cx43-positive cells were detected in the control group. Western blot analysis further confirmed that cTnI and Cx43 were not expressed in the control group, while cTnI and Cx43 was higher in the RGO + 5-aza group than in the RGO and 5-aza groups. These results suggest that MSCs can be induced by RGO to differentiate into cardiomyocyte-like cells in vitro, and that RGO in combination with 5-aza enhance differentiation of MSCs.

Aquaporin 4 inhibition decreased synthesis of cytokines by acetazolamide in the hippocampus of rats with pentrazol-induced chronic epilepsy

Epilepsy refers to a clinical syndrome generated by spontaneous seizures in the central nervous system. Epilepsy triggers a complex pathological process including inflammatory response and aquaporin 4 (AQP4) increase. It has been reported that AQP4 helps to enhance the immunological function of the central nervous system in pathological conditions, but the relationship between AQP4 and inflammatory cytokines is poorly understood in chronic epilepsy processes. As an inhibitor of sulfonamide carbonic anhydrase (CA), acetazolamide (AZA) may inhibit water infiltration through AQP4. In this context, pentylenetetrazole (PTZ) is used to induce the chronic epilepsy model in rats to study the chronic epilepsy effects of AQP4 inhibition on proinflammatory cytokine expression in the hippocampus and proinflammatory cytokine quantification analysis of the plasma. Based on the assumption that AQP4 regulates proinflammatory cytokine expression, this article aims to demonstrate this effect in chronic epilepsy of rats. Rats were divided into four groups and were treated with different drugs: saline (Control), acetazolamide (AZA), pentylenetetrazole (PTZ), and pentylenetetrazole plus acetazolamide (PTZ+AZA). The data showed that seizures increased proinflammatory cytokine expression and that AZA significantly inhibited AQP4 expression. Overall, the results suggested that AQP4 inhibition could weaken excitotoxicity in epileptogenesis by reducing proinflammatory cytokines in the hippocampus. The findings provide a new insight into the involvement of cerebral edema insult and proinflammatory cytokines in the process of chronic epilepsy.

Glabridin nanosuspension for enhanced skin penetration: formulation optimization, in vitro and in vivo evaluation

Glabridin, a polyphenolic flavonoid from licorice, has inspired great interest for its antioxidant, anti-inflammatory and skin-lightening activities. However, low water solubility and poor stability of glabridin impedes its topical application in cosmetic products and therapies of dermal diseases. The purpose of this study was to develop a nanosuspension formulation of glabridin to improve its skin permeation. Glabridin nanosuspensions were prepared using anti-solvent precipitation-homogenization method, and Box-Behnken design was adopted to investigate the effects of crucial formulation variables on particle size and to optimize the nanosuspension formulation. The optimal formulation consisted of 0.25% glabridin, 0.47% Poloxamer 188 and 0.11% Polyvinylpyrrolidone K30, and the obtained nanosuspension showed an average particle size of 149.2 nm with a polydispersity index of 0.254. Furthermore, the nanosuspension exhibited significantly enhanced drug permeation flux of glabridin through rat skin with no lag phase both in vitro and in vivo, compared to the coarse suspension and physical mixture. The glabridin nanosuspension showed no significant particle aggregates and a drug loss of 5.46% after storage for 3 months at room temperature. With its enhanced skin penetration, the nanosuspension might be a more preferable formulation for topical administration of poorly soluble glabridin.

Two-step warming solvothermal syntheses, luminescence and slow magnetic relaxation of isostructural dense LnMOFs based on nanoscale 3-connected linkers

Two isostructural 3D dense LnMOFs exhibiting either photoluminescence or slow magnetic relaxation are assembled under two-step warming solvothermal conditions.

Dialkoxybenzo[j]fluoranthenes: synthesis, structures, photophysical properties, and optical waveguide application

Dialkoxybenzo[j]fluoranthenes were readily synthesized, and showed strong fluorescence in solution and solid state, and exhibited excellent optical waveguide behavior.

Characteristics and kinetics of hexavalent chromium reduction by gallic acid in aqueous solutions

Gallic acid (GA) is a naturally occurring plant polyphenol compound. Experiments were conducted to study the kinetics and effects of pH, temperature, irradiation, and initial hexavalent chromium (Cr(VI)) concentration on Cr(VI) reduction by GA. Results indicated that Cr(VI) could be reduced to chromium oxide (Cr(III)) with GA in a wide range of pH values from 2.0 to 8.5. The reaction followed a pseudo-first-order kinetic model with respect to Cr(VI) and GA in acid conditions (pH 2.0-5.0). However, the reaction did not follow the pseudo-first-order kinetic model at pH 6.5 and 8.5. Removal efficiencies and reaction rate constants of Cr(VI) significantly increased with decreasing pH value and increasing temperature. The effect of irradiation on Cr(VI) reduction increased with increasing pH, and irradiation improved the removal efficiency of Cr(VI) by 11.29% at pH 6.5. At pH 2.0, nearly all molar ratios of GA required for the reduction of Cr(VI) were 1:2 (±0.1) under different initial Cr(VI) concentrations; however, the molar ratios of GA required for the reduction of Cr(VI) were 1:1.29, 1:1.43, and 1:1.69, respectively, when the initial Cr(VI) concentrations were 10, 25, and 50 mg/L at pH 5.5.

[Laboratory evaluation of remediation of nitrobenzene contaminated aquifer by using groundwater circulation well]

A two-dimension simulated sand box was set up to investigate the influencing factors, such as the initial groundwater level, aeration rate and the initial groundwater rate, that affect groundwater circulation well (GCW) by determining the intensity of groundwater circulation which was characterized by the variation of groundwater level before and after aeration. The optimal operating parameters were used to remediate nitrobenzene contaminated aquifer. The results demonstrated that: GCW could be well operated under the conditions of 45 cm groundwater level, 0.7 m3 · h(-1) aeration rate. The effects of groundwater velocity less than 1.0 m · d(-1) could be ignored. The lateral mobility rate of nitrobenzene was faster than that of longitudinal. The average concentration of nitrobenzene was 246.97 mg · L(-1) on day 50 of leakage. During the remediation of circulation well, an efficient organics remediation region was gradually formed around the circulation well. The organics in this region was removed preferentially, and the concentration decreased continuously. Besides the efficient remediation region, there was a transient region, where the concentration of organics was influenced by the combined effects of adsorption/desorption and migration potential of organics. During the whole remediation process, the concentration of nitrobenzene went through three stages described as rapid removal, slow removal. After 14h aeration, the nitrobenzene average concentration was reduced to 71.19 mg L(-1). The residual nitrobenzene was distributed in regions far away from GCW. Therefore, nitrobenzene contaminated aquifer could be well remediated by GCW, and there were optimal operation conditions and appropriate remediation time which guaranteed the best remediation effect.

Superconductivity in topological insulator Sb2Te3 induced by pressure

Topological superconductivity is one of most fascinating properties of topological quantum matters that was theoretically proposed and can support Majorana Fermions at the edge state. Superconductivity was previously realized in a Cu-intercalated Bi₂Se₃ topological compound or a Bi₂Te₃ topological compound at high pressure. Here we report the discovery of superconductivity in the topological compound Sb₂Te₃ when pressure was applied. The crystal structure analysis results reveal that superconductivity at a low-pressure range occurs at the ambient phase. The Hall coefficient measurements indicate the change of p-type carriers at a low-pressure range within the ambient phase, into n-type at higher pressures, showing intimate relation to superconducting transition temperature. The first principle calculations based on experimental measurements of the crystal lattice show that Sb₂Te₃ retains its Dirac surface states within the low-pressure ambient phase where superconductivity was observed, which indicates a strong relationship between superconductivity and topology nature.

Semi-automatic laboratory goniospectrometer system for performing multi-angular reflectance and polarization measurements for natural surfaces

In this paper, the design and operation of the Northeast Normal University Laboratory Goniospectrometer System for performing multi-angular reflected and polarized measurements under controlled illumination conditions is described. A semi-automatic arm, which is carried on a rotated circular ring, enables the acquisition of a large number of measurements of surface Bidirectional Reflectance Factor (BRF) over the full hemisphere. In addition, a set of polarizing optics enables the linear polarization over the spectrum from 350 nm to 2300 nm. Because of the stable measurement condition in the laboratory, the BRF and linear polarization has an average uncertainty of 1% and less than 5% depending on the sample property, respectively. The polarimetric accuracy of the instrument is below 0.01 in the form of the absolute value of degree of linear polarization, which is established by measuring a Spectralon plane. This paper also presents the reflectance and polarization of snow, soil, sand, and ice measured during 2010-2013 in order to illustrate its stability and accuracy. These measurement results are useful to understand the scattering property of natural surfaces on Earth.

Superconductivity of the topological insulator Bi2Se3 at high pressure

The pressure-induced superconductivity and structural evolution of Bi2Se3 single crystals are studied. The emergence of superconductivity at an onset transition temperature (Tc) of about 4.4 K is observed at around 12 GPa. Tc increases rapidly to a maximum of 8.2 K at 17.2 GPa, decreases to around 6.5 K at 23 GPa, and then remains almost constant with further increases in pressure. Variations in Tc with respect to pressure are closely related to the carrier density, which increases by over two orders of magnitude from 2 to 23 GPa. High-pressure synchrotron radiation measurements reveal structural transitions at around 12, 20, and above 29 GPa. A phase diagram of superconductivity versus pressure is also constructed.

Seroprevalence of hepatitis C, hepatitis B virus and syphilis in HIV-1 infected patients in Shandong, China

To determine the seroprevalence of hepatitis C virus (HCV), hepatitis B virus (HBV) and syphilis in HIV-1-infected patients and related risk factors in Shandong province, China, we tested all eligible participants between 2000 and 2010 for the presence of anti-HCV antibody, hepatitis B surface antigen (HBsAg) and non-treponemal antibodies for syphilis after informed consent. Among 2087 HIV-infected patients, anti-HCV antibody was present in 41.2%, HBsAg in 12.6% and rapid plasma reagin (RPR) reactivity in 19.6%. In the multivariate logistic regression model, male gender (adjusted odds ratio [aOR] = 1.41), minority ethnicity (aOR = 1.72), syphilis infection (aOR = 1.40), former paid blood donors (aOR = 3.36), blood transfusion recipients (aOR = 2.91) and injection drug users (aOR = 1.98) were significantly associated with HCV infection. HCV infection (aOR = 1.40) and being men who have sex with men (aOR = 2.38) were significantly associated with syphilis infection. Co-infection with HCV, HBV and syphilis was observed frequently in all described subgroups of HIV infection. The results of this study suggest that it is necessary to screen for these viruses and syphilis in all Chinese HIV-infected patients.

Remediation of nonaqueous phase liquid polluted sites using surfactant-enhanced air sparging and soil vapor extraction

A two-dimensional laboratory sand tank was installed to study the remediation efficiency of surfactant-enhanced air sparging (-SEAS) coupled with soil vapor extraction (SVE) in nonaqueous phase liquid (NAPL) polluted sites. During initial stages of remediation, it was more reasonable to use conventional air sparging coupled with SVE. When most free NAPLs were removed and contaminant removal rate was maintained at a relatively low level, surfactant was added to the groundwater. During enhanced remediation, lower interfacial tension caused residual NAPLs in the porous media to slightly migrate, making the downstream contaminant concentration somewhat higher. The polluted area, however, was not more enlarged than before. The decrease in surface tension resulted in increased air saturation in the groundwater and the extent of the air influence zone. After 310 hours, 78.7% of the initial chlorobenzene mass had volatilized, 3.3% had migrated out of the sand profile, 17.5% was in the vadose zone, and 0.5% remained in the groundwater, thus revealing that SEAS/SVE can effectively improve the remediation of NAPL polluted sites.

Stability and strength of transition-metal tetraborides and triborides

Using density functional theory, we show that the long-believed transition-metal tetraborides (TB(4)) of tungsten and molybdenum are in fact triborides (TB(3)). This finding is supported by thermodynamic, mechanical, and phonon instabilities of TB(4), and it challenges the previously proposed origin of superhardness of these compounds and the predictability of the generally used hardness model. Theoretical calculations for the newly identified stable TB(3) structure correctly reproduce their structural and mechanical properties, as well as the experimental x-ray diffraction pattern. However, the relatively low shear moduli and strengths suggest that TB(3) cannot be intrinsically stronger than c-BN. The origin of the lattice instability of TB(3) under large shear strain that occurs at the atomic level during plastic deformation can be attributed to valence charge depletion between boron and metal atoms, which enables easy sliding of boron layers between the metal ones.

[Impact of depth and moisture to diesel degradation in sand layer of vadose zone]

Through the experiment simulated sand columns, the biodegradation characteristics of diesel in sand layers (including fine sand, medium sand and coarse sand) with different depths and moisture contents were studied. The results show that the depth and moisture content of medium are important factors in affecting the efficiency of diesel degradation. In the same medium conditions, the higher moisture content of the medium, the higher biological activity, and biological degradation efficiency of diesel are observed. The nature of medium affects the efficiency of diesel degradation in vadose zone. The finer particles of the medium, the higher ability of diesel degradation is. It is expressed as: fine sand > medium sand > coarse sand. Volatilization and biodegradation are important factors in affecting natural attenuation of diesel in vadose zone.

[Clinical analysis of vertebral laminae reconstruction after laminectomy and pedicle screw fixation in treating lumbar spinal stenosis]

OBJECTIVE

To observe the curative effects of vertebral laminae reconstruction after laminectomy and pedicle screw fixation for the treatment of lumbar spinal stenosis in early (at the 3rd months after operation) and metaphase (at the more than 1 year after operation).

METHODS

Twenty-two patients with lumbar spinal stenosis were treated by vertebral laminae reconstruction after laminectomy and pedicle screw fixation, there were 12 males and 10 females, the age was from 55 to 76 years with an average of 65.8 years, including single segment (6 cases), double segments (13 cases) and three segments (3 cases) of L3-S1. The follow-up period was for 1-3 years, preoperative and postoperative (at the 3rd months after operation and last follow-up) to assess the subjective symptoms, physical signs, the limit of daily activities and bladder function according to JOA scoring; and observe saggital diameter measurement and radiological changes through X-ray and CT.

RESULTS

All the patients were followed up, the JOA scoring were respectively 5.3 +/- 1.6, 23.2 +/- 2.0, 22.9 +/- 2.4 before operation and after operation (at the 3rd after operation and last follow-up); at the 3rd months after operation, 18 cases obtain excellent results, 3 good, fair 1, and at the last follow-up, 17 cases obtain excellent results, 3 good, fair 2, there was no significant difference between two postoperative periods (u = 0.413, P < 0.05). The mean sagittal diameter of narrow segment was respectively (6.8 +/- 0.9), (17.6 +/- 2.5), (16.9 +/- 1.8) mm before operation, at the 3rd months after operation and the last follow-up. Through statistics processing, there was significant different comparing JOA scoring at 3 months after operation, last follow-up with preoperative (P < 0.05). There was significant difference of vertebral canal sagittal diameter between at the 3rd months after operation and before operation (t = 35.116, P < 0.01); there was no significant difference between at the 3rd months after operation and last follow-up (t = 1.814, P > 0.05). The CT examination of last follow-up showed the vertebral canal have no stenosis, the dural sac and nerve roots have no compression, the rebuilt vertebral laminae have fused well, the graft bone are no absorbed and the fixation have no failure.

CONCLUSION

Treatment of lumbar spinal stenosis with vertebral lamina reconstruction after vertebral laminectomy and pedicle screw fixation can obtain satisfactory results in early and metaphase. The method had advantages of decompression thoroughly and fixation solidly, and could prevent vertebral canal restenosis causing by nerve oppression of the postoperative scar and nerve adhesion.

Effect of S1P5 on proliferation and migration of human esophageal cancer cells

AIM: To investigate the sphingosine 1-phosphate (S1P) receptor expression profile in human esophageal cancer cells and the effects of S1P5 on proliferation and migration of human esophageal cancer cells.

METHODS: S1P receptor expression profile in human esophageal squamous cell carcinoma cell line Eca109 was detected by semi-quantitative reverse transcription polymerase chain reaction. Eca109 cells were stably transfected with S1P5-EGFP or control-EGFP constructs. The relation between the responses of cell proliferation and migration to S1P and S1P5 expression was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide and migration assay, respectively.

RESULTS: Both normal human esophageal mucosal epithelium and Eca109 cells expressed S1P1, S1P2, S1P3 and S1P5, respectively. Esophageal mucosal epithelium expressed S1P5 at a higher level than Eca109 cell line. S1P5 over-expressing Eca109 cells displayed spindle cell morphology with elongated and extended filopodia-like projections. The proliferation response of S1P5-transfected Eca109 cells was lower than that of control vector-transfected cells with or without S1P stimulation (P < 0.05 or 0.01). S1P significantly inhibited the migration of S1P5-transfected Eca109 cells (P < 0.001). However, without S1P in transwell lower chamber, the number of migrated S1P5-transfected Eca109 cells was greater than that of control vector-transfected Eca109 cells (P < 0.001).

CONCLUSION: S1P binding to S1P5 inhibits the proliferation and migration of S1P5-transfected Eca109 cells. Esophageal cancer cells may down-regulate the expression of S1P5 to escape the inhibitory effect.

[pH buffering capacity of landfill leachate contaminated aquifer sediments in different redox zones]

A simulated column filled with fine sand was constructed to investigate pH buffering capacity of aquifer sediments and its variation in different redox zones. Experimental results indicated that background pH buffering capacity of sediments was 324.93 pH(-1) mmol/kg, and the buffering capacities of cation exchange, calcium carbonate, silicate and secondary were 41.77 x pH(-1), 86.53 pH(-1), 47.33 pH(-1) and 149.31 x pH(-1) mmol/kg, respectively. pH buffering capacity increased 12.4%, 10.8%, 19.8% and 11.1% in MGZ/SRZ, IRZ, NRZ and ORZ, respectively. Cation exchange capacity (CEC) and base exchangeable cation (BEC) content of sediments in redox zones were lower than background content which was 11.59 x pH(-1) and 8.52 x pH(-1) mmol/kg, respectively. Base cation saturation was increasing first and then then decreasing, and it was higher than background of 63.47%. Therefore, the aquifer sediments have high pH buffering capacity. Research on the pH buffering capacity of landfill leachate polluted aquifer sediments in redox zones could provide theoretical evidences for remediation of polluted sites.

[Characteristics of bacteria variation and pollutants behavior in landfill leachate polluted site]

Static and dynamic simulated experiments were conducted to investigate the characteristics of bacterial variation in landfill leachate polluted site, and relations between attenuation, species-distribution, bioavailability of pollutants and bacterial activity. Results indicated that bacterial activity in soil and fine sand showed a trend of increase first and then decreased with time; the increase rate was up to 0.081 d(-1) and 0.022 d(-1) at the increasing stage,and the decrease rate reached 0.0095 d(-1) and 0.005 1 d(-1) at the decreasing stage, respectively. A clear correlation between attenuation of COD and variation of bacterial activity with time was shown; the removal efficiency of COD in soil was about 30% higher than that in fine sand, and the attenuation rate of COD was 500 mg/d in fine sand approximately. There was no clear correlation between ammonium-nitrogen attenuation and bacterial activity in short-term with time. Variation of heavy metals species and bioavailability was related to their properties, redox environment, and other factors.

[Study on performance of double mineral base liner using modified bentonite as active material]

The absorbing capacity of clay,roasting bentonites by 450 degrees C and dual-cation organobentonites of the pollutions in landfill leachate was compared through static experiment, and investigations were conducted into availability of controlling the permeating of landfill leachate and feasibility of removing the main pollutants in leachate on the double mineral base liners of clay/roasting bentonites by 450 degrees C and clay/dual-cation organobentonites by using nice landfill leachate as the filter fluid. Experiment indicated that the adsorption equilibrium time of landfill leachate in clay, roasting bentonites by 450 degrees C and dual-cation organobentonites was 24 h; the absorbing capacity of roasting bentonites by 450 degrees C and dual-cation organobentonites was larger than that of clay. Simultaneous the penetration coefficients of the two liners were respective 1.31 x 10(-8) cm x s(-1) and 2.80 x 10(-8) cm x s(-1); Double mineral base liners of clay/roasting bentonites by 450 degrees C owned larger absorbing capacity of NH4+, however, double mineral base liners of clay/dual-cation organobentonites had strong absorbing capacity of organic pollutants and the attenuation rate of COD was 33.82% higher than the other. Conclusion was drawn that different types of modified bentonite should be chosen as "the active layer" according to different styles of landfill pollutants.

[Buffer capacity of aquifer media polluted by landfill leachate]

A column filled with fine sand was constructed to investigate pH buffering capacity and redox buffering capacity of aquifer media. Experimental results indicated that calcium carbonate played a significant role in pH buffering; with the aggravating of landfill leachate pollution, the pH buffering capacity of calcium carbonate was increased; it increased from background value, which was 1.62 x pH(-1) mmol/kg, to 41.3 x pH(-1) mmol/kg. With the aggravating of landfill leachate pollution, the oxidation capacity (OXC) of aquifer media was decreased, and the reduction capacity (RDC) was increased. In unpolluted aquifer media, Fe3+ was the main component of OXC, and accounted for about 70.5% of OXC; TOC was the main component of RDC, and accounted for about 98.7% of RDC. Species of the minerals was related to the degree of pollution; large fraction of amorphous Fe3+ and part of crystalline Fe3+ were reduced near the pollution source, and the reduced product was mainly precipitated as FeCO3 and FeS. Deposit of produced Fe2+ led to ion-exchangeable Fe2+ content increased from 0.5% of uncontaminated aquifer media to 3%. Therefore, Fe3+ may act as a very significant redox buffer in aquifer.

[Redox zones and its functional bacteria in a contaminated landfill site]

A column filled with sandy soil was constructed to investigate biogeochemical process of leachate polluted zones. Experimental results demonstrated that four sequent redox zones appeared in pollution plume. The zones can be named sulfate reduction zone, iron reduction zone, nitrate reduction zone and oxygen reduction zone, ranges of them were 0-27 cm, 27-62 cm, 47-74 cm, 74-91 cm. In the redox zones bacterial community structure changed, and the preponderant bacteria were sulfate reduction bacteria (SRB), iron reduction bacteria (IRB), nitrate reduction bacteria (NRB) correspondingly, however there were other bacteria in the redox zones. Distribution of redox zones and functional bacteria means that there is not a significant boundary between redox zones, moreover one redox zone overlaps others. Evolvement of functional bacterial community brings the redox zones substitute.

[Contaminants natural attenuation of beitiantang landfills leachate polluted sites]

Redox zones and the natural attenuation of pollutants in landfill leachate polluted site through analyzing data monitored around the Beitiantang Landfills of Beijing City. The results indicated that redox zones existed in Beitiantang Landfill leachate polluted sites, and 5redox zones were classified depended on distribution rules and characteristics of indicative substrates, namely methanogenic zone, sulfate reduction zone, iron reduction zone, nitrate reduction zone and oxygen reduction zone. Attenuation efficiencies of different organic contaminants in redox zones were different. Content of volatile hydroxybenzene and cyanide in sulfate reduction zone were relative high, and they were 0.005 and 0.019 microg/L, respectively. Heavy metal content, such as Cr, Pb, Ni, As, Cu, Cd, Zn and Mn were relative high in methanogenic zone, and they were 25.11, 33.82, 29.93, 3.18, 2.3, 0.1, 283.1, 1220 microg/L, respectively. Therefore, redox zones played an important role on the attenuation of pollutants.

[Dynamitic development and evolution of redox zones in pollution plume]

A box filled with sandy soil was constructed to investigate dynamitic development and evolution of redox zones in landfill leachate-polluted plume. The results indicated that with time elapsing and pollution aggravating, redox zones moved ahead slowly; Methanogenic zone/ sulfate reduction zone extended gradually, and then inert zone appeared with further pollution. During the whole course of the dynamitic development and evolvement of redox zones, concentrations of TOC, sulfide, NH4(+) -N, HCO3-, CO2 and Fe2+ increased with time and decreased with distance; concentrations of NO3- and DO decreased with time and increased with distance; SO4(2-) concentration decreased first and then increased over time; but decreased with distance. Moreover, with time elapsing and pollution aggravating, the Fe3+ content of sediments was decrease and TOC was increase. Within oxygen reduction zone, nitrate reduction zone, iron reduction zone and methanogenic zone/sulfate reduction zone, Fe3+ content of sediments accounted for 70.5% of OXC decreased to 56.3%, 41%, 28.3% and 15%, and the TOC accounted for 98.7% of RDC increased to 102.0%, 107.0%, 142.9% and 162.1%, respectively; Fe2+ mainly precipitated as FeS and FeCO3, and accounted for 80.6%, 175.6%, 377.7% and 555.1% of total Fe2+, respectively.

[pH buffering capacity of geological media on landfill leachate]

The one-dimensional breakthrough soil column experiment and static experiment were constructed to investigate the spacial and temporal pH buffering capacity of the four natural geological media. Experimental results indicate that the background pH buffering capacity of fine sand, silt sand and clay is 79.9 x pH(-1) mmol/kg, 207.5 x pH(-1) mmol/kg, 456.4 x pH(-1) mmol/kg respectively. With the time going on and the distance closer to the leaching source, for each medium which is contaminated by the landfill leachate, the total pH buffering capacity decreases, the buffering capacity of calcium carbonate buffering system decreases, the buffering capacity of the silicate and cation exchange buffering system have no obvious changes, and the buffering capacity of the aluminium and ferric oxide buffering system also decrease, but the soil's buffering capacity of aluminium buffering system increases at first and then decreases. The temporal and spacial buffering capacity for each buffering system of the fine sand all increase appreciably. The order of the pH buffering capacity of the geological media on landfill leachate is fine sand < silt sand < clay < soil. The soil and clay have a good pH buffering capacity on landfill leachate as well as the controlling effect of the pollutants' transferring and diffusion.

[Terminal electron acceptor process in landfill leachate pollution plume]

A soil column filled with sandy soil was constructed to investigate changes of terminal electron acceptors (TEA) and TOC in redox zones of landfill leachate pollution plume, and their models were established, respectively. Results indicated that the time of peak-concentration appearance of different reducing products was related to the ability of terminal electron acceptors to compete for terminal electrons. The most competitive ones showed sharp concentration increased earlier. For example, the peak concentration of NO2(-) appeared earlier than that of Fe2+. The concentration of TOC increased in methanogenic zone, iron reduction zone, nitrate reduction zone and oxygen reduction zone, and its rate was 8.27, 8.56, 8.85, 9.06 and 9.11 mg/(L h), respectively. Degradation rate of contaminants by different microbes mainly depended on the amount and availability of terminal electron acceptors. The reaction rate was related to ability of terminal electron acceptors to compete for terminal electron, that is the stronger the ability of terminal electron acceptors to compete for terminal electrons, the easier could be used and consumed by microorganisms and the more sensitive to reflect on environmental pollution.

Clinical application of metallic stents in treatment of esophageal carcinoma

AIM: To evaluate the effects of self-expanding metal stents (SEMS) in patients with malignant esophageal obstruction and to analyze their prognosis and complications.

METHODS: Seventy-four metallic stents were placed under fluoroscopic guidance in 66 patients with esophageal obstruction secondary to carcinoma, of whom, 6 cases were complicated by fistula.

RESULTS: After seventy-two stents were successfully used in 66 cases without any severe complications (technical successful rate was 97%), the dysphagia score improved from 3.3±0.6 to 0.8±0.5 (P<0.01), and life quality improved significantly in all these patients. All fistulae were sealed immediately after coated stents were inserted in the six patients. New stents were placed in two patients: the stent migrated more than 2 cm, in one patient and the stent slipped into stomach in the other. Minor bleeding was found only in 28 patients during the operation. Reobstruction was found in 12 patients, but was successfully cured under endoscopy. The survival rate was 78%, 57% and 11% for 6 mo, 1 year and 2 years respectively.

CONCLUSION: Placement of SEMS is a simple, safe, quick and efficient surgical method for treating esophageal carcinoma obstruction. It may be used mainly as a palliative treatment of esophageal obstruction secondary to carcinoma.

[Iodine-131 therapy for large goiter with hyperthyroidism: clinical observation of 38 cases]

OBJECTIVE

To evaluate the therapeutic efficacy and safety of iodine-131 therapy for large goiter complicated by hyperthyroidism.

METHODS

After the diagnosis of large goiter complicated by hyperthyroidism was established, the weight of the patient's thyroid gland was determined, and the doses of iodine-131 calculated according to the formula currently available. After a single dose of oral iodine-131 capsule, the patients were observed for the therapeutic efficacy and side effects. Some patients were given the second or even the third dose of iodine-131.

RESULTS

All of the 38 patients were cured by 1 to 3 single doses of iodine-131 therapy, of whom 23 (60.5%) needed only a single dose for the cure, 13 (34.2%) required the second dose, and 2 (5.3%) necessitate a third dose. Hypothyroidism occurred in 4 cases (10.5%), and none of the patients developed hyperthyroidism crisis and dyspnea.

CONCLUSIONS

Iodine-131 therapy for serious goiter with hyperthyroidism is safe and effective, which can be used as a routine therapy for this condition.

[The changes of density of platelet glycoprotein (GP) II b/III a receptor in the perioperative period of gastrectomy in aged rats]

AIM

To investigate changes of density of platelet glycoprotein (GP) II b/III a receptor in the perioperative period of gastrectomy in aged rats.

METHODS

The subtotal gastrectomy operation was performed in 16 adult rats and 16 aged rats respectively. Platelet surface density of GP II b/III receptors were determined by flow cytometric analysis before and 6, 12, 24, 48, 72 hours after operation.

RESULTS

6, 12, 24, 48 and 72 hours after operation, the density of GP II b/III a in aged group increased continuously compared with preoperative period (6h, 12, 72: P < 0.05; 24, 48: P < 0.01).

CONCLUSION

Gastrectomy can lead to an increase of density of platelet GP II b/III a receptor in aged rats.

Human immunodeficiency virus type 1 (HIV-1) protein Vif inhibits the activity of HIV-1 protease in bacteria and in vitro

Human immunodeficiency virus type 1 (HIV-1) Vif is required for productive infection of T lymphocytes and macrophages. Virions produced in the absence of Vif have abnormal core morphology and those produced in primary T cells carry immature core proteins and low levels of mature capsid (M. Simm, M. Shahabuddin, W. Chao, J. S. Allan, and D. J. Volsky, J. Virol. 69:4582-4586, 1995). To investigate whether Vif influences the activity of HIV-1 protease (PR), the viral enzyme which is responsible for processing Gag and Gag-Pol precursor polyproteins into mature virion components, we transformed bacteria to inducibly express truncated Gag-Pol fusion proteins and Vif. We examined the cleavage of polyproteins consisting of matrix to PR (Gag-PR), capsid to PR (CA-PR), and p6Pol to PR (p6Pol-PR) and evaluated HIV-1 protein processing at specific sites by Western blotting using antibodies against matrix, capsid, and PR proteins. We found that Vif modulates HIV-1 PR activity in bacteria mainly by preventing the release of mature MA and CA from Gag-PR, CA from CA-PR, and p6Pol from p6Pol-PR, with other cleavages being less affected. Using subconstructs of Vif, we mapped this activity to the N-terminal half of the molecule, thus identifying a new functional domain of Vif. Kinetic study of p6Pol-PR autocatalysis in the presence or absence of Vif revealed that Vif and N'Vif reduce the rate of PR-mediated proteolysis of this substrate. In an assay of in vitro proteolysis of a synthetic peptide substrate by purified recombinant PR we found that recombinant Vif and the N-terminal half of the molecule specifically inhibit PR activity at a molar ratio of the N-terminal half of Vif to PR of about 1. These results suggest a mechanism and site of action of Vif in HIV-1 replication and demonstrate novel regulation of a lentivirus PR by an autologous viral protein acting in trans.

Immunoglobulin E and circulating immune complexes in endolymphatic hydrops

Levels of circulating immune complexes (CICs) in 59 patients with Meniere's disease and total serum immunoglobulin E (IgE) levels in a subgroup of 42 of the 59 were determined quantitatively for possible abnormalities of humoral immunity. Significant differences in average IgE levels between the 42 patients with Meniere's disease and 18 normal control subjects were not determined; however, five (11.9%) of the 42 patients were found to have obviously raised IgE levels. Elevated CIC levels were found in 19 (32.2%) of the 59 patients with Meniere's disease and in one (2.3%) of the 43 control subjects. This difference was statistically significant. The possible mechanisms of immune-mediated endolymphatic hydrops are discussed.