Determination of the total antioxidant capacity of the Chinese tea based on a novel "peroxidase/zirconium phosphonate"composite electrochemical sensor

In this work, a novel zirconium phosphonate (ZrPR1R2) was prepared by decorating both the aminoethoxy- group (R1) and the carboxypropyl- group (R2) on the zirconium phosphate layers in order to manipulate further the immobilization of the peroxidase (POD), and an antioxidant biosensor with higher sensitivity was constructed by dropping the POD/ZrPR1R2 composite onto the glassy carbon electrode surface. The activity of the POD/ZrPR1R2 composite was detected by Uv-vis spectra. The direct electrochemical behavior, the electrocatalytic response to dissolved oxygen and hydrogen peroxide, as well as the ability to detect total antioxidant capacity in tea sample were investigated by the methods of cyclic voltammetry. The results indicated that the immobilization of POD in ZrPR1R2 nanosheets matrix enhanced the enzymatic activity, and achieved the fast and direct electron transfer between POD and glassy carbon electrode. Moreover, the POD/ZrPR1R2 composite modified electrode show the electrocatalytic response to hydrogen peroxide in the linear range of 8.8×10-8 to 8.8×10-7 mol L-1, with the detection limit of 3.3×10-8 mol L-1. Attributing to the sensitive response to dissolved oxygen, the total antioxidant capacity can be detected directly in the real tea water by this POD/ZrPR1R2 composite modified electrode.

[Genetic and clinical analysis of X-linked hypophosphatemic rickets]

Objective: To investigate the clinical and genetic features, and treatment of X-linked hypophosphatemic rickets (XLH). Methods: In this retrospective study, we reviewed the medical records of 25 pediatric patients with XLH who were admitted to Department of Endocrinology Genetics and Metabolism,Beijing Children's Hospital from January 2010 to January 2020. The clinical characteristics, PHEX gene variants, as well as clinical outcome of the patients were summarized. To analyze the correlation between genotype and phenotype, the patients were divided into different subgroups according to the location of the variants, including N-terminal-located vs. C-terminal-located variant, and Zn-binding domain exon 17 or 19 variant vs. non-exon 17 or 19 variant. The age at onset, height standard deviation score (HtSDS), intercondylar or intermalleolar distance, fasting serum phosphorus, and HtSDS and intercondylar or intermalleolar distance at the final follow-up were compared by rank sum test or t text. Results: Among the 25 children with XLH, 8 were boys and 17 were girls. The median age of onset was 1.2 (1.0, 1.8) years, and the median age of diagnosis was 2.5 (1.5, 4.3) years. The main clinical manifestations were abnormal gait and lower limb deformity. The HtSDS was -2.0(-3.2, -0.8), and the intercondylar or intermalleolar distance was 4.5 (3.0, 6.0) cm. The fasting serum phosphorus level was 0.8 (0.7, 0.9) mmol/L, while the serum alkaline phosphatase level was (721±41) U/L and the serum calcium level was (2.5±0.1) mmol/L. Three patients (12%) had parathyroid hormone levels above the upper limit of the normal range. Twenty-five patients (100%) showed radiographic changes of active rickets. Nephrocalcinosis was found in 2 cases (9%). Twenty-four different PHEX variations were detected in 25 patients, among whom 11 (44%) had not been reported previously. No hot spot variation was found. No statistical differences (all P>0.05) were identified in clinical features and outcomes either in comparing patients with N-terminal (21 cases) and C-terminal (4 cases) variants, or in comparing patients with variant located in exon 17 or 19 (4 cases) or not (21 cases). Twenty-four cases (96%) were treated regularly with phosphate supplements and active vitamin D. After 2.7 (1.6, 5.0) years of follow-up, clinical symptoms were relieved in 96% (24/25) of the patients. The HtSDS after treatment had no significant difference compared to that before treatment (-2.0(-3.2, -0.8) vs.-2.0(-2.8, -1.1),Z =-0.156, P>0.05), while the intercondylar or intermalleolar distance after treatment was significantly reduced compared to that before treatment (4.5(3.0, 6.0) vs. 1.5(0, 3.3) cm, Z =-3.043, P<0.05). Bone X-rays were reexamined in 17 cases after treatment, and radiographic signs of rickets were improved. Eighteen cases had secondary hyperparathyroidism and 7 cases had nephrocalcinosis. Conclusions: The main clinical manifestations of XLH are abnormal gait, lower limb deformity and short stature. A high proportion of novel variations of PHEX gene but no hot spot variation neither genotype-phenotype correlation are found. Regular treatment with phosphate supplements and active vitamin D can significantly improve the symptoms except for the height. However, the rate of adverse events including secondary hyperparathyroidism and nephrocalcinosis seems to be high.

[Clinical follow-up and genetic analysis of six cases with hypophosphatasia]

Objective: To analyze the clinical, genetic characteristics and follow-up data of Chinese patients with hypophosphatasia (HPP). Methods: A retrospective analysis was conducted on six children with HPP admitted to the Department of Endocrinology, Genetics and Metabolism in Beijing Children's Hospital from October 2010 to January 2019. Summarized the clinical and follow-up data of all six patients, as well as the pathogenic variants of five children. Results: The serum alkaline phosphatase levels of all six children (five males and one female) were significantly reduced (2-49 U/L). The 6 patients aged from 2 months to 6 years and 4 months, 4 infantile HPP, 1 childhood HIP and 1 odonto HPP. The four patients with infantile HPP presented with anorexia, slow weight gain and hypercalcemia, whereas the one patient with childhood HPP and the other patient with odonto HPP had tooth loss. The patient with childhood HPP also manifested with motor dysfunction. Genetic testing was conducted for five patients and 4 unrelated Chinese families and revealed 10 variations in ALPL gene, including 7 missense variation, 1 insertion variation, 1 frameshift variation, 1 deletion variation.Of which 3 were novel (p.Y28C, p.268, F>L, p.A176V).One of the infantile patients lost follow-up and the other three deceased. The clinical conditions were much improved with medical intervention for patients with childhood, orodonto HPP. Conclusions: While HPP patients with different ages of onset present with common features, the prognosis differ significantly. The prognosis is good for patients with childhood, orodonto HPP and poor for patients with infantile HPP. Genetic testing is the main method for definitive diagnosis.

[The mediating role of psychological capital between occupational stress and suicidal ideation]

Objective: To analyze the mediating effect of psychological capital (PsyCap) between occupational stress and suicidal ideation. Methods: In September 2017, stratified-cluster sampling method was adopted to select employees of an electronic manufacturing service industry as respondents for a questionnaire survey in Jiangsu province. The demographic characteristics of employees were collected. A total of 2 465 employees were investigated, and 2 216 valid questionnaires were collected. The level of occupational stress and PsyCap was assessed by the Effort-Reward Imbalance Scale(ERI)and PsyCap Questionnaire. Results: The age of 2 216 employees was (28.70±5.26) years old, including 1 230 males (55.5%). The scores of occupational stress on effort, reward and over-commitment were (3.08±0.63), (3.73±0.60) and (2.51±0.68), respectively. The average ERI index (ratio of effort to return) was (0.88±0.39). The total score of PsyCap was (86.62±15.23). The detection rate of suicidal ideation within two weeks was 13.9% (309/2 216). The average score of effort and over-commitment and the ERI index were positively correlated with the number of suicidal ideation detected within two weeks, with correlation coefficients about 0.081, 0.141 and 0.164, respectively. The average score of reward and total score of PsyCap were negatively correlated with the number of suicidal ideation detected within two weeks, with correlation coefficients about -0.206 and -0.228, respectively. The mediating effect results showed that PsyCap had mediating effect on the effort, reward, over-commitment and suicidal ideation of occupational stress respectively, with mediating effect values of -0.087 (95%CI: -0.018,-0.019), -0.299 (95%CI: -0.428,-0.200) and 0.096 (95%CI: 0.0394, -0.170). The mediating effect percentages were 9.43%, 17.92%, and 9.54%, respectively. Conclusion: PsyCap has a mediating effect between effort, reward, over-commitment of occupational stress and suicidal ideation.

[Application of an occupational health risk assessment method in dioctyl phthalate producing enterprise]

Objective: To find the risk assessment model of [di (2-ethylhexyl) phthalate, DEHP] fitting well for producing companies. Methods: The Cluster Sampling method was used in selecting a DEHP producing company in the occupational health and workplace environment monitoring study conducted between July and August in 2017. Data was collected by site evaluating and workplace environment monitoring. According to GBZ/T 298-2017《Technical Guidelines for Occupational Health Risk Assessment of Chemical Hazards in the Workplace》, a qualitative assessment method and a semi-quantitative comprehensive index method were chosen as the models and were compared. Results: The occupational health risk of the two methods rated 4 (high risk) and 2 (negligible risk) . Conclusion: The semi-quantitative comprehensive index method is more comprehensive and accurate when used to assess the occupational health risk caused by DEHP.

[Efficacy comparison of purse-string vs. linear closure of the wound following stoma reversal: systematic review and meta-analysis]

Objective: To compare the efficacy of purse-string skin closure (PSC) and linear skin closure (LSC) in stoma reversal. Methods: Randomized controlled trials (RCT) comparing the use of PSC and LSC during stoma reversal were searched from Embase, PubMed, Web of Science, CNKI net, Wanfang database, VIP Chinese Science and Technology Journal Database. Literature inclusion criteria: (1) randomized controlled trials about comparing PSC and LSC in stoma reversal published publicly; only including English literature; (2) patients undergoing stoma (ileostomy or colostomy) reversal without limitation of age, sex and ethnicity; (3) PSC group receiving the suture of the dermis layer of the skin by purse-string suture, and forming a pore channel in the center of the skin after tightening and knotting, in order to achieve the purpose of secondary healing; the LSC group receiving the suture of the skin with conventional simple interrupted suture; (4) the enrolled literatures needed to include at least one of the following outcome indicators: the primary outcome was the incidence of SSI; the secondary outcome included the operation time, incisional hernia, hospital stay and patient satisfaction. Literature exclusion criteria: (1) duplicate published studies, incomplete studies, reviews, case reports, unpublished literature, retrospective studies, non-RCT. The search time ended on November 15, 2018. The basic information and important outcome indicators of the included articles were extracted. The Cochrane bias risk assessment tool was used to evaluate the quality of the selected literatures. Patient satisfaction was assessed using the following scales: (1) the patient and observer scar assessment scale (POSAS); (2) the body image questionnaire (BIQ); (3) Likert scale; (4) short form 36 (SF-36), version 2; (5) visual analog scale (VAS). Meta-analysis was performed using Review manager 5.3 software provided by the Cochrane Collaboration. Results: A total of 9 randomized controlled trials were included, involving 806 patients with 411 cases in the PSC group and 395 cases in the LSC group. Baseline data such as age, gender, body mass index (BMI), underlying disease, and anesthesia grading were not significantly different between the two groups (all P>0.05). The quality of these nine randomized controlled trials was high. Because the evaluation methods for these studies are not uniform, it is impossible to conduct a meta-analysis of patient satisfaction. However, from the summary results of various studies, the postoperative satisfaction of the purse-string suture group was better than that of the linear suture group. The meta-analysis showed that there was significant difference in postoperative SSI incidence between the PSC group and the LSC group [OR=0.14, 95%CI: 0.08-0.24, P<0.00001], while there were no significant differences in incidence of incisional hernia [OR=0.66, 95%CI: 0.24-1.82, P=0.42], operation time [MD=0.61, 95%CI: -3.17-4.38, P=0.75], and hospital stay [MD=-0.26, 95%CI: -0.82-0.30, P=0.37]. Conclusions: PSC can be used for closure of the wound following stoma reversal. Compared with LSC, PSC can significantly reduce the incidence of SSI, and increase patients' satisfaction.

Incidence and mortality of nasopharyngeal carcinoma: interim analysis of a cluster randomized controlled screening trial (PRO-NPC-001) in southern China

BACKGROUND

Previous mass screening studies have shown that IgA antibodies against Epstein-Barr Virus (EBV) can facilitate early detection of nasopharyngeal carcinoma (NPC), but the impact of EBV-antibody screening for NPC-specific mortality remains unknown.

PATIENTS AND METHODS

A prospective, cluster randomized, controlled trial for NPC screening (PRO-NPC-001) was conducted in 3 selected towns of Zhongshan City and 13 selected towns of Sihui City in southern China beginning in 2008. Serum samples of the screening group were tested for two previously selected anti-EBV antibodies. Subjects with serological medium risk were subsequently retested annually for 3 years, and those with serological high risk were referred to otorhinolaryngologists for diagnostic check-up. An interim analysis was carried out to evaluate the primary end points of the NPC-specific mortality and the early diagnostic rate, and the secondary end point of the NPC incidence, through linkage with the database of Zhongshan City.

RESULTS

Among 70 296 total subjects, 29 413 screened participants (41.8% of the total subjects) in the screening group and 50 636 in the control group, 153 (43.3 per 100 000 person-year), 62 (55.3 per 100 000 person-year) and 99 (33.1 per 100 000 person-year) NPC cases were identified. The early diagnostic rates of NPC were significantly higher in the participants (79.0%, P < 0.0001) and the screening group (45.9%, P < 0.0001) compared with the control group (20.6%). Although no differences were found between NPC-specific mortality of the screening group and the control group [relative risk (RR)= 0.82, 95% confidence interval (CI) 0.37-1.79], lower NPC-specific mortality was noticed among participants from the screening group versus the control group (RR = 0.22, 95% CI 0.09-0.49).

CONCLUSION

IgA antibodies against EBV can identify high-risk population and was effective in screening for early asymptomatic NPC. Although the mortality reduction was not significant in the primary end point, we noted encouraging evidence of a mortality reduction in screening participants in this interim analysis.

CLINICAL TRIAL NUMBER

NCT00941538.

[Clinical analysis of two cases of imported children Zika virus infection in China]

OBJECTIVE

To analyze the clinical characteristics, outcome and diagnosis of two cases of imported children Zika virus infection in China.

METHOD

A retrospective analysis was performed on clinical characteristics, treatment and outcome of two cases of imported children with Zika virus infection in February 2016 in Enping People's Hospital of Guangdong.

RESULT

Two cases of children with imported Zika virus infection resided in an affected area of Venezuela, 8-year-old girl and her 6 year-old brother. The main findings on physical examination included the following manifestations: fever, rash, and conjunctivitis. The rash was first limited to the abdomen, but extended to the torso, neck and face, and faded after 3-4 d. The total number of white blood cells was not high and liver function was normal. The diagnosis of two cases of Zika virus infection was confirmed by the expert group of Guangdong Provincial Center for Disease Control and Prevention, according to the epidemiological history, clinical manifestations and Zika virus nucleic acid detection results.Treatment of Zika virus infection involves supportive care. Two Zika virus infection children had a relatively benign outcome.

CONCLUSION

At present, Zika virus infection in children is an imported disease in China. No specific therapy is available for this disease. Information on long-term outcomes among infants and children with Zika virus disease is limited, routine pediatric care is advised for these infants and children.

[Durability of protective effect of resin-based coating material on root surface]

OBJECTIVE

To compare the durability of resin-based root-surface coating material and all-in-one self-etching adhesive on root surface in vitro.

METHODS

Human extracted premolars or molars with intact roots were selected. The cementum was removed using a periodontal scaler to expose root dentin. The root surface was coated with an acid-resistant nail varnish, leaving a window of 3 mm×3 mm on the exposed dentin.The window was covered with either PRG Barrier Coat (PRG) or Clearfil S3 Bond (CS3). After water aging for 14 d, specimens were immersed in acid buffer at pH 4.5 for 4 d and the demineralization buffer was changed every 24 h. Then the specimen was split longitudinally through the center of the 'window' and the cross-sectional surface was observed with scanning electron microscope (SEM). After fixed and dehydrated, the prepared samples were coated with platinum. The coating material, root dentin and the interface was observed by scanning electron microscope (SEM). The thickness of the coating material was measured on the SEM images. Regarding toothbrush wear test, coronal dentindisks were prepared and covered with PRG and CS3, respectively. After storage in water for 24 h, the specimen was subjected to the toothbrush wear tester for 100, 200, 300, 500, 700, 1 500 brushing cycles. A slurry of fluoride toothpaste (1:2 ratio of toothpaste and deionized water by weight) was used and the brushing load was 300 N. The surface microstructure of remaining coating material was analyzed using SEM. The wear depths were determined by a profilometer. Statistical analysis was performed with SPSS 20.0 by one-way ANOVA. The level of significance was at 0.05.

RESULTS

Application of PRG Barrier Coat produced a coating layer of (47.1±27.3) μm, while CS3 presented a thin film of (5.7±2.1) μm in thickness. The exposed dentin was hermetically sealed and no obvious gap was observed at the interface in both PRG and CS3 groups. There was no dentin demineralization observed in both groups after water aging. The wear depths of PRG and CS3 increased along with the numbers of brushing cycles. PRG wore at a significant lower pace than CS3 did (P<0.05).

CONCLUSION

PRG coating resin had similar performances as CS3 on protecting root dentin from demineralization after water aging. What's more, PRG demonstrated a higher toothbrush wear resistance than CS3. We concluded that PRG Barrier Coat contained S-PRG filler may be an effective coating material for protecting exposed root from both chemical and mechanical challenges. Further studies should be carried out to evaluate the long-term reliability of the rootsurface coating materials under the clinical setting.

+Antisense oligonucleotide targeting survivin inhibits growth by inducing apoptosis in human osteosarcoma cells MG-63

Survivin may play an important role in the development of osteosarcoma. In this study, we chose osteosarcoma cell line MG-63, which highly expressed survivin, to observe the effects of antisense oligonucleotide targeting survivin on the apoptosis induction and proliferation inhibition. It was shown in our results that the apoptosis rate and the proliferation inhibition rate increased significantly in survivin-positive cells MG-63 by using MTT and flow cytometry methods. We found that the growth inhibition rate and apoptosis rate were changed in a dose-dependent way. When the concentration of antisurvivin oligonucleotide was 600 nM, the effects reached the peak. RT-PCR and western-blot methods were used to detect the mRNA and protein expression of survivin in MG-63. We observed that the mRNA and protein expression of survivin reduced after transfected with antisurvivin oligonucleotides at the concentration of 200 nM, 400 nM and 600 nM. At the same time, we found that the mRNA and protein expression of Fas were up-regulated with the concentration of antisurvivin oligonucleotides from 200 nM to 600 nM. It was negative associated with the expression change of survivin. These data suggested that survivin should play an important role in the development of osteosarcoma and the survivin blockaded by using antisurvivin oligonucleotide could inhibit the proliferation and induce apoptosis of osteosarcoma by decreasing the expression of survivin and activate the Fas-mediated apoptosis. Down-regulation of survivin by antisense oligonucleotide might be an effective strategy to the treatment of osteosarcoma and might improve the therapeutic effect.

KEYWORDS

osteosarcoma, Survivin, apoptosis, Fas.

Ultrahigh vacuum, variable temperature, dual scanning tunneling microscope system operating under high magnetic field

We present a dual scanning tunneling microscope (DSTM) system operating between 2.2 K and room temperature, in a split-coil superconducting magnetic field up to 12 T and in ultrahigh vacuum. The DSTM consists of two compact STMs, each having x, y, and z coarse positioning piezoelectric steppers with embedded capacitive positioning sensor for navigation. Each STM can be operated independently and can achieve atomic resolution. The DSTM and the sample is configured in a way that allows the magnetic field orientation to be varied continuously from normal to parallel to the sample surface. Together with the sample, the DSTM can form a nanometer scale three terminal setup for transport measurement.

Reduced endocytosis and altered lysosome function in cisplatin-resistant cell lines

We isolated human KB adenocarcinoma cisplatin-resistant (CP-r) cell lines with multidrug-resistance phenotypes because of reduced accumulation of cisplatin and other cytotoxic compounds such as methotrexate and heavy metals. The uptake of horseradish peroxidase (HRPO) and Texas Red dextran was decreased several-fold in KB-CP-r cells, indicating a general defect in fluid-phase endocytosis. In contrast, although EGF receptors were decreased in amount, the kinetics of EGF uptake, a marker of receptor-mediated endocytosis, was similar in sensitive and resistant cells. However, 40-60% of the (125)I-EGF released into the medium after uptake into lysosomes of KB-CP-r cells was TCA precipitable as compared to only 10% released by sensitive cells. These results indicate inefficient degradation of internalised (125)I-EGF in the lysosomes of KB-CP-r cells, consistent with slower processing of cathepsin L, a lysosomal cysteine protease. Treatment of KB cells by bafilomycin A(1), a known inhibitor of the vacuolar proton pump, mimicked the phenotype seen in KB-CP-r cells with reduced uptake of HRPO, (125)I-EGF, (14)C-carboplatin, and release of TCA precipitable (125)I-EGF. KB-CP-r cells also had less acidic lysosomes. KB-CP-r cells were crossresistant to Pseudomonas exotoxin, and Pseudomonas exotoxin-resistant KB cells were crossresistant to cisplatin. Since cells with endosomal acidification defects are known to be resistant to Pseudomonas exotoxin and blocking of endosomal acidification mimics the CP-r phenotype, we conclude that defective endosomal acidification may contribute to acquired cisplatin resistance.