Surgical treatment of nasopharyngeal cancer - a consensus recommendation from two Chinese associations

BACKGROUND

Surgical treatment is playing an increasingly important role in the management of nasopharyngeal carcinoma (NPC). This consensus focuses on the indications for optimal surgery, and surgical methods in the whole process of treatment for NPC to provide a useful reference to assist these difficult clinical decisions.

METHODOLOGY

A thorough review of available literature on NPC and surgery was conducted by the Association for the prevention and treatment of nasopharyngeal carcinoma in China, international exchange and promotion Association for medicine and healthcare, and the Committee on nasopharyngeal cancer of Guangdong provincial anticancer association. A set of questions and a preliminary draft guideline was circulated to a panel of 1096 experienced specialists on this disease for voting on controversial areas and comments. A refined second proposal, based on a summary of the initial voting and different opinions expressed, was recirculated to the experts in two authoritative medical science and technology academic groups in the prevention and treatment of NPC in China for review and reconsideration.

RESULTS

The initial round of questions showed variations in clinical practice even among similar specialists, reflecting the lack of high-quality supporting data and resulting difficulties in formulating clinical decisions. Through exchange of comments and iterative revisions, recommendations with high-to-moderate agreement were formulated on general treatment strategies and details of surgery, including indications and surgical approaches.

CONCLUSION

By standardizing the surgical indications and practice, we hope not only to improve the surgical outcomes, but also to highlight the key directions of future clinical research in the surgical management of NPC.

[Comparison of postoperative mid-term and long-term quality of life between Billroth-I gastroduodenostomy and Billroth-II gastrojejunostomy after radical distal gastrectomy in patients with gastric cancer: a cohort study based on a case registry database]

Objective: The pattern of digestive tract reconstruction in radical gastrectomy for gastric cancer is still inconclusive. This study aims to compare mid-term and long-term quality of life after radical gastrectomy for distal gastric cancer between Billroth-I (B-I) and Billroth-II (B-II) reconstruction. Methods: A retrospective cohort study was conducted.Clinicopathological and follow-up data of 859 gastric cancer patients were colected cellected from the surgical case registry database of Gastrointestinal Surgery Center of Sichuan University West China Hospital, who underwent radical distal gastric cancer resection between January 2016 and December 2020. Inclusion criteria: (1) gastric cancer confirmed by preoperative gastroscopy and biopsy; (2) elective radical distal major gastrectomy performed according to the Japanese Society for Gastric Cancer treatment guidelines for gastric cancer; (3) TNM staging referenced to the American Cancer Society 8th edition criteria and exclusion of patients with stage IV by postoperative pathology; (4) combined organ resection only involving the gallbladder or appendix; (5) gastrointestinal tract reconstruction modality of B-I or B-II; (6) complete clinicopathological data; (7) survivor during the last follow-up period from December 15, 2021 to January 15, 2022. Exclusion criteria: (1) poor compliance to follow-up; (2) incomplete information on questionnaire evaluation; (3) survivors with tumors; (4) concurrent malignancies in other systems; (5) concurrent psychiatric and neurological disorders that seriously affected the objectivity of the questionnaire or interfered with patient's cognition. Telephone follow-up was conducted by a single investigator from December 2021 to January 2022, and the standardized questionnaire EORTC QLQ-C30 scale (symptom domains, functional domains and general health status) and EORTC QLQ-STO22 scale (5 symptoms of dysphagia, pain, reflux, restricted eating, anxiety; 4 single items of dry mouth, taste, body image, hair loss) were applied to evaluate postoperative quality of life. In 859 patients, 271 were females and 588 were males; the median age was 57.0 (49.5, 66.0) years. The included cases were divided into the postoperative follow-up first year group (202 cases), the second year group (236 cases), the third year group (148 cases), the fourth year group (129 cases) and the fifth year group (144 cases) according to the number of years of postoperative follow-up. Each group was then divided into B-I reconstruction group and B-II reconstruction group according to procedure of digestive tract reconstruction. Except for T-stage in the fourth year group, and age, tumor T-stage and tumor TNM-stage in the fifth year group, whose differences were statistically significant between the B-I and B-II reconstruction groups (all P<0.05), the differences between the B-I and B-II reconstruction groups in terms of demographics, body mass index (BMI), tumor TNM-stage and tumor pathological grading in postoperative follow-up each year group were not statistically significant (all P>0.05), suggesting that the baseline information between B-I reconstruction group and the B-II reconstruction group in postoperative each year group was comparable. Evaluation indicators of quality of life (EORTC QLQ-C30 and EORTC QLQ-STO22 scales) and nutrition-related laboratory tests (serum hemoglobin, albumin, total protein, triglycerides) between the B-I reconstruction group and B-II reconstruction group in each year group were compared. Non-normally distributed continuous variables were presented as median (Q(1),Q(3)), and compared by using the Wilcoxon rank sum test (paired=False). The χ(2) test or Fisher's exact test was used for comparison of categorical variables between groups. Results: There were no statistically significant differences in all indexes EORTC QLQ-30 scale between the B-I reconstruction group and the B-II reconstruction group among all postoperative follow-up year groups (all P>0.05). The EORTC QLQ-STO22 scale showed that significant differences in pain and eating scores between the B-I reconstruction group and the B-II reconstruction group were found in the second year group, and significant differences in eating, body and hair loss scores between the B-I reconstruction group and the B-II reconstruction group were found in the third year group (all P<0.05), while no significant differences of other item scores between the B-I reconstruction group and the B-II reconstruction group were found in postoperative follow-up of all year groups (P>0.05). Triglyceride level was higher in the B-II reconstruction group than that in the B-I reconstruction group (W=2 060.5, P=0.038), and the proportion of patients with hyperlipidemia (triglycerides >1.85 mmol/L) was also higher in the B-II reconstruction group (19/168, 11.3%) than that in the B-I reconstruction group (0/34) (χ(2)=0.047, P=0.030) in the first year group with significant difference. Albumin level was lower in the B-II reconstruction group than that in the B-I reconstruction group (W=482.5, P=0.036), and the proportion of patients with hypoproteinemia (albumin <40 g/L) was also higher in the B-II reconstruction group (19/125, 15.2%) than that in the B-I reconstruction group (0/19) in the fifth year group, but the difference was not statistically significant (χ(2)=0.341, P=0.164). Other nutrition-related clinical laboratory tests were not statistically different between the B-I reconstruction and the B-II reconstruction in each year group (all P>0.05). Conclusions: The effects of both B-I and B-II reconstruction methods on postoperative mid-term and long-term quality of life are comparable. The choice of reconstruction method after radical resection of distal gastric cancer can be based on a combination of patients' condition, sugenos' eoperience and operational convenience.

Observation of Spin Splitting Torque in a Collinear Antiferromagnet RuO_{2}

Current-induced spin torques provide efficient data writing approaches for magnetic memories. Recently, the spin splitting torque (SST) was theoretically predicted, which combines advantages of conventional spin transfer torque (STT) and spin-orbit torque (SOT) as well as enables controllable spin polarization. Here we provide the experimental evidence of SST in collinear antiferromagnet RuO_{2} films. The spin current direction is found to be correlated to the crystal orientation of RuO_{2} and the spin polarization direction is dependent on (parallel to) the Néel vector. These features are quite characteristic for the predicted SST. Our finding not only presents a new member for the spin torques besides traditional STT and SOT, but also proposes a promising spin source RuO_{2} for spintronics.

Effects of sDR5-Fc fusion protein on infant mice with ulcerative colitis via the TRAIL-DR5 pathway

To explore effects of the sDR5-Fc fusion protein on ulcerative colitis of infant mice via the TRAIL-DR5 pathway, 50 female mice were randomly divided into 5 groups, i.e., control group (group A), dextran sulfate sodium group (group B), hIgG group (group C), 10 mg/kg sDR5-Fc group (group D), and 20 mg/ kg sDR5-Fc group (group E). The acute ulcerative colitis models were established. The weights and disease activity index (DAI) of each group were monitored daily. In addition, the pathological changes of colon tissues were observed by Hematoxylin-Eosin staining. The number of macrophages in colon tissues was detected by immunohistochemistry assay. Changes in the expression of inflammatory factors in colon tissues were detected by quantitative real-time polymerase chain reaction (PCR). Lipopolysaccharide (LPS) of different concentrations was utilized alone or in combination with TRAIL to stimulate the NCM460 cells. The activation of NLRP3 inflammasomes was detected by Western blot. The apoptosis of NCM460 cells was detected by flow cytometry. The results showed that in groups B and C, the body weights decreased, the DAI increased, the colon epithelial cells were injured, the inflammatory cells were infiltrated, and the macrophages in colon tissues increased significantly. In groups D and E, the body weights increased, the DAI decreased, the inflammation was significantly improved, the macrophages decreased significantly, and the gene expression levels of NLRP3, Caspase-1, and IL-1β decreased significantly. Thus, sDR5-Fc could inhibit the activation of NLRP3 inflammasomes induced by TRAIL, thereby decreasing the apoptosis of NCM460 cells. In conclusion, the sDR5-Fc fusion protein could block the TRAIL-DR5 pathway to reduce the expression of NLRP3 inflammasomes, thereby improving ulcerative colitis.

[Polarization of bone marrow-derived macrophages induced by recombinant Trichinella spiralis cysteine protease inhibitors in vitro]

OBJECTIVE

To investigate the regulatory role of recombinant Trichinella spiralis cysteine protease inhibitors (rTs-Cys) in induction of polarization of bone marrow-derived macrophages (BMDMs) in vitro.

METHODS

BMDMs were captured and cultured in conditioned medium for 7 days. Then, mature BMDMs were harvested and assigned into four groups. Cells in Group A (negative control) were given 10 ng/mL IFN-γ combined with 100 ng/mL LPS, cells in Group B (positive control) were treated with IL-4 and IL-10 (at 10 ng/mL both), and cells in Group C (recombinant protein alone) were stimulated with 1 μg/mL rTs-Cys, while cells in Group D (protein co-culture) were simultaneously treated with 1 μg/mL rTs-Cys, 10 ng/mL IFN-γ and 100 ng/mL LPS. Cells and culture supernatant were collected 24 hour post-treatment, and the proportions of F4/80⁺, CD11b⁺, CD206⁺ and CD11c⁺ cells were detected by flow cytometry. The levels of interleukin IL-6 (IL-6), tumor necrosis factor-α (TNF-α), IL-10 and transforming growth factor-β (TGF-β) in the cell culture supernatant were measured by ELISA and the CD86⁺ and CD206⁺ phenotypes were identified by immunofluorescent staining.

RESULTS

Flow cytometry detected no significant difference in the proportion of F4/80⁺ CD11b⁺ CD11c⁺ cells among the four groups (F = 46.184, P < 0.001), and a lower proportion of F4/80⁺ CD11b⁺ CD11c⁺ cells was seen in groups C and D than in group A (all P values < 0.001). There was a significant difference in the proportion of F4/80⁺ CD11b⁺ CD206⁺ cells among the four groups (F = 11.032, P < 0.001), and a greater proportion of F4/80⁺ CD11b⁺ CD206⁺ cells was seen in groups C and D than in group A (all P values < 0.01). Immunofluorescent staining showed higher CD206⁺ expression and lower CD86⁺ expression in groups C and D than in Group A. There were significant differences in the IL-6 and (F = 3.950, P < 0.001) and TNF-α (F = 205.827, P < 0.001) levels in the cell culture supernatants among the four groups, and significantly lower IL-6 and TNF-α levels were measured in groups C and D than in Group A (both P < 0.05). There were significant differences in the IL-10 and (F = 8.274, P < 0.001) and TGF-β (F = 13.559, P < 0.01) levels in the cell culture supernatants among the four groups, and greater IL-10 and TGF-β levels were measured in Group C than in Group A (both P values < 0.01). In addition, the TGF-β level was significantly higher in Group D than in Group A (P < 0.05); however, there was no significant difference in the IL-10 level between groups D and A (P > 0.05).

CONCLUSIONS

rTs-Cys may induce the polarization of BMDMs to antiinflammatory M2 macrophages in vitro and inhibit the activation of M1 macrophages.

[Effect of standardized surgical treatment and multidisciplinary treatment strategy on the prognosis of gastric cancer patients: report of a single-center cohort study]

Objective: To explore the effect of standardized surgical treatment and multidisciplinary treatment strategy on the treatment outcomes of gastric cancer patients. Methods: A single-center cohort study was carried out. Clinicopathological and long-term follow up data of primary gastric cancer patients were retrieved from the database of Surgical Gastric Cancer Patient Registry (SGCPR) in West China Hospital of Sichuan University. Finally, 4516 gastric cancer patients were included and were divided into three groups according to time periods (period 1 group: exploration stage of standardized surgical treatment, 2000 to 2006, 967 cases; period 2 group: application stage of standardized surgical treatment, 2007 to 2012, 1962 cases; period 3 group: optimization stage of standardized surgical treatment and application stage of multidisciplinary treatment strategy, 2013 to 2016, 1587 cases). Differences in clinical data, pathologic features, and prognosis were compared among 3 period groups. Follow-up information was updated to January 1, 2020. The overall follow-up rate was 88.9% (4016/4516) and median follow-up duration was 51.58 months. Survival curve was drawn by Kaplan-Meire method and compared with log-rank test. Univariate and multivariate analyses were performed by Cox proportional hazards model. Results: There were significant differences among period 1, period 2 and period 3 groups in the rates of D2/D2+ lymphadenectomy [14.4%(139/967) vs. 47.2%(927/1962) vs. 75.4%(1197/1587), χ(2)=907.210, P<0.001], in the ratio of proximal gastrectomy [19.8%(191/967) vs. 16.6%(325/1962) vs. 8.2%(130/1587), χ(2)=100.020, P<0.001], and in the median intraoperative blood loss (300 ml vs. 100 ml vs. 100 ml, H=1126.500, P<0.001). Besides, the increasing trend and significant difference were also observed in the median number of examined lymph nodes among period 1, period 2 and period 3 groups (14 vs. 26 vs. 30, H=987.100, P<0.001). Survival analysis showed that the 5-year overall survival rate was 55.3% in period 1, 55.2% in period 2 and 62.8% in period 3, and significant difference existed between period 3 and period 1 (P=0.004). The Cox proportional hazards model analysis showed that treatment period (period 3, HR=0.820, 95%CI: 0.708 to 0.950, P=0.008), postoperative chemotherapy (HR=0.696, 95%CI: 0.631 to 0.768, P<0.001) and mid-low gastric cancer (HR=0.884, 95%CI: 0.804 to 0.973, P=0.011) were good prognostic factors. Whereas old age (≥65 years, HR=1.189, 95%CI: 1.084 to 1.303, P<0.001), palliative resection (R1/R2, HR=1.538,95%CI: 1.333 to 1.776, P<0.001), large tumor size (≥5 cm, HR=1.377, 95%CI: 1.239 to 1.529, P<0.001), macroscopic type III to IV (HR=1.165, 95%CI: 1.063 to 1.277, P<0.001) and TNM stage II to IV(II/I:HR=1.801,95%CI:1.500~2.162,P<0.001;III/I:HR=3.588, 95%CI: 3.028~4.251, P<0.001; IV/I: HR=6.114, 95%CI: 4.973~7.516, P<0.001) were independent prognostic risk factors. Conclusion: Through the implementation of standardized surgical treatment technology and multidisciplinary treatment model, the quality of surgery treatment and overall survival increase, and prognosis of gastric cancer patients has been improved.

[Mid-term outcomes of coronary artery bypass surgery with left radial artery bypassed to right main coronary artery of severe stenosis]

Objective: To evaluate the mid-term outcomes of coronary artery bypass grafting (CABG) with left radial artery (RA) graft bypassed to right main coronary artery (RCA) of severe stenosis. Methods: Between September 2014 and April 2019, a total of consecutive 47 patients who had severe stenosis (≥90%) of RCA underwent total arterial revascularization, with left RA bypassed to RCA. There were 31 males and 16 females, with a mean age of (56.5±9.7) years old. The perioperative outcomes were observed and mid-term results were followed up. Results: A total of 46 left internal mammary artery (LIMA) grafts, 47 left radial artery (LRA), and 40 right RA grafts (RRA) were harvested with pedicles. LIMA was bypassed to LAD in 43 patients, RRA was to diagonal branches, ramus or oblique marginal in 37 cases, and LRA was to RCA. All grafts (except 3 composite Y or T grafts) were single. Mean graft number was 2-4 (2.7±0.9). There was one death due to cardiac tamponade. Three patients had postoperative atrial fibrillation, 1 had a forearm hematoma, 1 had acute renal insufficiency, and 2 had acute myocardial infarction. The mean tracheal intubation duration was 3.5-20.3 (8.3±4.7) hours, and the mean hospital stay was 6-13 (7.1±2.9) days. The average follow-up was 3-47 (23.3±7.5) months, with a follow-up rate of 86.96% (40/46). There were no major cardiovascular events during the follow-up. Three month after surgery, the mean left ventricular ejection fraction was significantly improved than that of pre-operation (60.0%±4.0% vs 42.4%±7.5%, P=0.003). Computed tomography angiography (CTA) examination showed that 58.7% (27/46) of patients had patent LRA after a mean follow-up duration of (19.5±7.3) months. Conclusion: CABG with LRA bypassed to RCA of severe stenosis proves to be safe and effective, with good mid-term outcomes.

[Association between both maternal and fetal angiotensinogen gene single nucleotide polymorphism and preeclampsia/eclampsia]

Objective: To explore the association between preeclampsia/eclampsia and maternal and fetal angiotensinogen SNPs. Methods: From January 2008 to October 2015, a case-parents/mother-control designed study was conducted among 347 preeclampsia/eclampsia cases and 700 controls to collect related information on their demographic characteristics and to detect the related angiotensinogen SNPs' genotypes. Both log-linear and unconditional logistic regression methods were employed to investigate the genetic effects of maternal/fetal angiotensinogen SNPs on preeclampsia/eclampsia. Multivariate binary unconditional logistic regression model and covariance were used to analyze the relationship between BMI before pregnancy, weight gain during pregnancy and overweight and obesity in preschool children. Results: Both fetal angiotensinogen rs3789679 GA and AA genotype were associated with the reduced risks of preeclampsia/eclampsia, with ORs as 0.73 (95%CI: 0.55-0.96) and 0.62 (95%CI: 0.39-0.98), respectively. For fetal angiotensinogen rs2493132, individuals that carrying the TT genotype, presented a positive association with the risk of preeclampsia/eclampsia, with OR as 1.60 (95%CI: 1.08-2.37). However, these associations were not statistically significant after the correction of the false discovery rate. It was observed that fetal rs3789679 could reduce the risk of preeclampsia/eclampsia (OR=0.73, 95%CI: 0.55-0.96) under the dominant model (GA+AA/GG) while fetal rs2493132 increased the risk of preeclampsia/eclampsia (OR=1.66, 95%CI: 1.13-2.44) under the recessive model (TT/CC+CT). Maternal rs5051 presented an association with preeclampsia/eclampsia (OR=1.33, 95%CI: 1.01-1.76) under the dominant model (TC+CC/TT). Conclusions: Results from the dominant model showed that both fetal rs3789679 GA and AA genotype reduced the risk of preeclampsia/eclampsia and maternal rs5051 TC while CC genotype increased the risk of preeclampsia/eclampsia. Fetal rs2493132 TT genotype seemed to be associated with the risk of preeclampsia/eclampsia under the recessive model.

[Comparison of safety and efficacy between proximal gastrectomy and total gastrectomy for upper third gastric cancer: a Meta-analysis]

Objective: To compare the safety and efficacy between proximal gastrectomy and total gastrectomy and to ascertain the optimized procedure for patients with upper third gastric cancer through meta-analysis. Methods: The English literatures about proximal gastrectomy and total gastrectomy for upper third gastric cancer were searched from PubMed, EMBASE, the Cochrane Library and the Web of Science database and then collected. The quality of enrolled studies was independently assessed by two researchers according to the Newcastle-Ottawa Scale for retrospective studies and Jadad scale for RCT studies. The basic information of the literature and related clinical indicators were extracted. The primary endpoints were 5-year overall survival rate and recurrence rate. The secondary endpoints were operative time, intraoperative blood loss, morbidity of postoperative complication, incidence of anastomotic stenosis and incidence of reflux esophagitis. Considering the influence of tumor staging on postoperative clinicopathological features and prognosis, a subgroup analysis was performed on the literatures including cases of early gastric cancer and those including cases of tumor stage I to IV. Statistical analyses were carried out by the "metafor" and "meta" software packages from RevMan 5.3 software and R software (V3.2.4). Results: Twenty-five literatures involving 3667 patients (proximal gastrectomy for 1483, total gastrectomy for 2184) were finally enrolled for analysis, including 24 retrospective studies with ≥ 5 points and 1 RCT with 3 points, and all the literatures were of high quality. A total of 2516 cases of early gastric cancer were enrolled in 18 articles, including 1027 with proximal gastrectomy and 1489 with total gastrectomy. A total of 1151 cases with stage I to IV were enrolled in 7 articles, including 456 in proximal gastrectomy group and 695 in total gastrectomy group. Five-year survival rate was not significantly different for patients with early gastric cancer between the proximal gastrectomy group and total gastrectomy group (OR=1.16, 95% CI: 0.72 to 1.86, P=0.54). Similarly, there was no significant difference for patients with stage I to IV between the proximal gastrectomy group and the total gastrectomy group (OR=1.19, 95% CI: 0.92 to 1.53, P=0.18). Recurrence rate of early gastric cancer patients was not significantly different between the proximal gastrectomy group and the total gastrectomy group (OR=0.40, 95% CI: 0.05 to 3.16, P=0.39).However, the recurrence rate of the proximal gastrectomy group was higher than that of the total gastrectomy group in patients with stage I to IV (OR=1.55, 95% CI: 1.09 to 2.19, P<0.01), whose difference was statistically significant. There was no significant differences in postoperative complication between the groups, both in patients with early gastric cancer, and in those with stage I to IV (both P>0.05). The incidences of postoperative anastomotic stenosis (OR=3.57, 95% CI: 1.82 to 6.99, P<0.01) and reflux esophagitis (OR=2.83, 95% CI: 1.23 to 6.54, P=0.01) in the proximal gastrectomy group were significantly higher than those in the total gastrectomy group in patients with early gastric cancer. Conclusions: There is no significant difference in long-term survival outcomes between total gastrectomy and proximal gastrectomy for upper gastric tumors. However,incidence of anastomotic stenosis and reflux esophagitis, and tumor recurrence rate after total gastrectomy are significantly lower. The total gastrectomy is recommended as the first choice for advanced upper gastric tumor.

[Effects of intrathecal transient receptor potential vanilloid 1 blocker on cervical distension induced visceral pain response]

Objective: With the aid of an acute visceral pain model of uterine cervical distension (UCD), the present study aimed to observe the effects of intrathecal administration of transient receptor potential vanilloid 1 (TRPV1) antagonist SB-366791 on UCD induced-visceral nociception as well as its involved molecular mechanisms. Methods: A total of 30 Sprague-Dawley-derived adult virgin female rats were used. UCD model was established under isoflurane inhalation anesthesia. Briefly, a lower abdominal incision at midline was made to expose the uteral cervix, two metal rods were inserted through both sides of the cervix separately, one rod was fixed and the other one was connected to a pulley system with application of manual weighted traction (0, 25, 50, 75 or 100 g) for simulating 1 h of cervical distension. In addition, 12 Sprague-Dawley-derived adult virgin female rats were subjected to intrathecal catheter implantation, and UCD was established 7 days later. The rats were divided randomly into two groups; one group was administrated with intrathecal SB-366791 while the other was administrated with the same volume of saline as control. The 75 g distension force was then applied for an hour and the electromyographic (EMG) of musculus rectus abdominis, heart rate as well as respiratory frequency were measured continuously during the surgery. The spinal cord (T(12)-L(2)) was collected 30 minutes after UCD for the detection of changes of c-FOS and TRPV1 expression. Results: UCD increased EMG activity (P<0.05) and c-FOS expression (P<0.05) in the deep dorsal horn region and central canal of the spinal cord (T(12)-L(2)) in a stimuli-dependent manner, the expression of TRPV1 in the T(12)-L(2) spinal cord also increased in response to UCD stimulation (P<0.05). Compared with the saline group, intrathecal SB-366791 significantly decreased EMG activity (P<0.05) as well as spinal c-FOS (P<0.05) expression induced by UCD. Conclusions: UCD in rats increases EMG activity of musculus rectus abdominis as well as spinal c-FOS and TRPV1 expression. Intrathecal administration of TRPV1 antagonist SB-366791 significantly decreases the visceral nociception induced by UCD.

Improved anchoring nails: design and analysis of resistance ability : Tensile test and finite element analysis (FEA) of improved anchoring nails used in temporomandibular joint (TMJ) disc anchor

Background

Anchorage is one of the most important treatments for severe temporomandibular joint disorder (TMD). Anchoring nails have shown great success in clinical trials; however, they can break under pressure and are difficult to remove. In this study, we aimed to evaluate an improved anchoring nail and its mechanical stability.

Methods

The experiment consisted of two parts: a tensile test and finite element analysis (FEA). First, traditional and improved anchoring nails were implanted into the condylar cortical bone and their tensile strength was measured using a tension meter. Second, a three-dimensional finite element model of the condyles with implants was established and FEA was performed with forces from three different directions.

Results

The FEA results showed that the total force of the traditional and improved anchoring nails is 48.2 N and 200 N, respectively. The mean (±s.d.) maximum tensile strength of the traditional anchoring nail with a 3–0 suture was 27.53 ± 5.47 N. For the improved anchoring nail with a 3–0 suture it was 25.89 ± 2.64 N and with a 2–0 suture it was above 50 N. The tensile strengths of the traditional and improved anchoring nails with a 3–0 suture was significantly different (P = 0.033–< 0.05). Furthermore, the difference between the traditional anchoring nail with a 3–0 suture and the improved anchoring nail with a 2–0 suture was also significantly different (P = 0.000–< 0.01).

Conclusion

The improved anchoring nail, especially when combined with a 2–0 suture, showed better resistance ability compared with the traditional anchoring nail.

[Effect of perioperative multi-day low dose ketamine infusion on prevention of postmastectomy pain syndrome]

Objective: To investigate the effects of multi-day low dose ketamine infusion for postmastectomy pain syndrome (PMPS) after breast cancer surgery. Methods: This study was a prospective randomized controlled trial. From June 2015 to May 2016 in Affiliated Yiwu Hospital of Wenzhou Medical University, 66 patients with breast cancer surgery were randomly divided into control group (group C) and ketamine group (group K). Patients in group K were infused with 0.5 mg/kg of ketamine mixed in 250 ml of 0.9% normal saline in 1 h daily for 7 days. Patients in group C were infused the same dose of 0.9% normal saline. Anesthesia induction in both groups were given intravenous midazolam, sufentanil, propofol, vecuronium and intermittent positive pressure ventilation after tracheal intubation, anesthesia was maintained with propofol and remifentanil. After awakening, all patients were monitored in postanesthesia care unit (PACU) and given patient-controlled intravenous analgesia(PCIA). Pain scores were assessed using visual analogue scales (VAS) during PACU, 4 h, 24 h and 2-5 d after surgery, simultaneously analgesic requirement were recorded. Patients were evaluated Hospital Anxiety and Depression Scale (HADS) 5 d after surgery . The patients were followed up for 6 months. At 3 m, 6 m after surgery, the incidence of PMPS, the level of pain, pain site and HADS scale were assessed. Results: The VAS score uring PACU, 4 h, 24 h and 2-5 d after surgery in group K( (2.5±0.8), (2.4±0.5), (2.4±0.5), (2.0±0.4), (1.5±0.5), (1.0±0.4), 1(1), respectively) was lower than those in group C ((2.9±1.0), (2.9±0.6), (2.6±0.5), (2.3±0.5), (1.8±0.6), (1.5±0.5), 1(0), respectively). There was statistically difference between the two groups (all P<0.05). The consumption of analgesics required at each time postoperation in group K were also lower than that of group C(all P<0.05). Followed up for 6 months, 2 lost in group C, 1 lost in group K. The incidence of PMPS in group K at 3 months and 6 months after surgery was significantly lower(25% and 22%) than that in group C(52% and 45%)(χ(2)=4.729, 3.842, all P<0.05). There were no significant difference in pain level and site between two groups of PMPS patients (all P>0.05). There were no significant difference of HADS scale preoperative and 5 d after surgery between two groups (all P>0.05); and HADS scale in group K at 3 m and 6 m after surgery was significantly lower than that in group C(all P<0.05). Conclusion: Perioperative continuous multi-day low dose ketamine infusion can effectively reduce the incidence of PMPS after breast cancer surgery.

Antidamping-Torque-Induced Switching in Biaxial Antiferromagnetic Insulators

We investigate the current-induced switching of the Néel order in NiO(001)/Pt heterostructures, which is manifested electrically via the spin Hall magnetoresistance. Significant reversible changes in the longitudinal and transverse resistances are found at room temperature for a current threshold lying in the range of 10^{7}  A/cm^{2}. The order-parameter switching is ascribed to the antiferromagnetic dynamics triggered by the (current-induced) antidamping torque, which orients the Néel order towards the direction of the writing current. This is in stark contrast to the case of antiferromagnets such as Mn_{2}Au and CuMnAs, where fieldlike torques induced by the Edelstein effect drive the Néel switching, therefore resulting in an orthogonal alignment between the Néel order and the writing current. Our findings can be readily generalized to other biaxial antiferromagnets, providing broad opportunities for all-electrical writing and readout in antiferromagnetic spintronics.

Tunneling anisotropic magnetoresistance driven by magnetic phase transition

The independent control of two magnetic electrodes and spin-coherent transport in magnetic tunnel junctions are strictly required for tunneling magnetoresistance, while junctions with only one ferromagnetic electrode exhibit tunneling anisotropic magnetoresistance dependent on the anisotropic density of states with no room temperature performance so far. Here, we report an alternative approach to obtaining tunneling anisotropic magnetoresistance in α′-FeRh-based junctions driven by the magnetic phase transition of α′-FeRh and resultantly large variation of the density of states in the vicinity of MgO tunneling barrier, referred to as phase transition tunneling anisotropic magnetoresistance. The junctions with only one α′-FeRh magnetic electrode show a magnetoresistance ratio up to 20% at room temperature. Both the polarity and magnitude of the phase transition tunneling anisotropic magnetoresistance can be modulated by interfacial engineering at the α′-FeRh/MgO interface. Besides the fundamental significance, our finding might add a different dimension to magnetic random access memory and antiferromagnet spintronics.

Tunneling anisotropic magnetoresistance is promising for next generation memory devices but limited by the low efficiency and functioning temperature. Here the authors achieved 20% tunneling anisotropic magnetoresistance at room temperature in magnetic tunnel junctions with one α′-FeRh magnetic electrode.

[Psychopathological characteristics in patients with deviation of nasal septum: a preliminary analysis]

Objective: To investigate the psychopathological characteristics in patients with deviation of nasal septum. Methods: Between May 2015 and December 2015, fourty-four patients with deviated nasal septum and 37 patients with vocal cord polyp as control were included in this study. Psychological characteristics were evaluated by a series of questionnaire instruments including symptom checklist-90 (SCL-90), self-rating depression scale (SDS) and self-rating anxiety scale (SAS). Visual analogue scale (VAS) and rhinomanometry through front nostril were used to evaluate nasal symptom. The correlation between psychological characteristics and nasal symptom was evaluated. SPSS 20.0 software was used to analyze the data. Results: The SCL-90 score in nasal septal deviation group was 130.4±48.3. The total score and total average score of SCL-90 had no significant difference between nasal septal deviation group and the Chinese standard or control group(t value was 0.469, 0.112, 1.575, 1.564, respectively, all P>0.05). The scores of somatization, depression and anxiety factors in nasal septal deviation group were higher than control group (t value was 2.380, 2.133, 1.969, respectively, all P<0.05). The proportion of positive patients in these three factors between nasal septal deviation group and control group had significant differences (χ² value was 11.585, 9.610, 5.429, respectively, all P<0.05). The scores of SDS and SAS in nasal septal deviation group were 46.0±10.6 and 43.0±10.2, which were higher than that in the Chinese standard and control group (t value was 5.342, 6.236, 1.476, 3.013, respectively, all P<0.05). There were 9 patients companying with depression or anxiety (20.5%, 20.5%, respectively) and 5 patients companying with depression and anxiety in nasal septal deviation group (11.4%). There were positive correlation not only between the scores of SDS and the depression factor of SCL-90 but also between the scores of SAS and the anxiety factor of SCL-90 (Z=0.415, P=0.005, Z=0.445, P=0.002, respectively). The scores of SDS and SAS had positive correlation (Z=0.392, P=0.008). The VAS score of nasal obstruction was 6.0±3.2. The rhinomanometry in inspiratory and expiratory phase were (0.202±0.140) kPa·S/cm³ and (0.230±0.161) kPa·S/cm³. Besides the positive correlation between the rhinomanometry in inspiratory phase and SDS (Z=0.332, P=0.045), the psychological scores, including SCL-90 score, depression, anxiety factors score, SAS and SDS, had no correlation with VAS scores and rhinomanometry (r value was -0.030, -0.052, -0.026, 0.107, 0.185, 0.066, 0.160, 0.203, respectively, all P>0.05). Conclusions: High prevalence of depression and anxiety is found in patients with deviation of nasal septum. The SCL-90 score is consistent with SDS and SAS. Besides the positive correlation between the rhinomanometry in inspiratory phase and SDS, the psychological scores (SCL-90 score, depression, anxiety factors score, SAS and SDS) have no correlation with VAS score and rhinomanometry.

[Effect of intravenous infusion with lidocaine on rapid recovery of laparoscopic cholecystectomy]

Objective: To investigate the effect of intravenous infusion with lidocaine on rapid recovery of laparoscopic cholecystectomy. Methods: This study was a prospective randomized controlled trial. From February to August 2016 in Affiliated Yiwu Hospital of Wenzhou Medical University, 60 patients scheduled for laparoscopic cholecystectomy under general anesthesia were involved and randomly divided into control group (n=30) and lidocaine group (n=30). Patients in lidocaine group received lidocaine 1.5 mg/kg intravenously before induction and followed by 2.0 mg·kg(-1)·h(-1) to the end of surgery. Patients in control group received equal volumes of saline intravenously. Anesthesia induction in both groups were given intravenous midazolam 0.03 mg/kg, sufentanil 0.2 μg/kg, propofol 2.0 mg/kg and cisatracuium 0.2 mg/kg. Anesthesia was maintained with propofol 0.05-0.20 mg·kg(-1)·min(-1) and remifentanil 0.1-0.5 μg·kg(-1)·min(-1) for laryngeal mask airway which bispectral index (BIS) value maintained at 40-60. BIS, heart rate(HR) and mean arterial pressure(MAP) were recorded before anesthesia induction, before and immediately after laryngeal mask implantation, intraoperative 30 min and anesthesia awake. Pain scores were assessed using visual analogue scales (VAS) at postoperation immediately, 30 min during postanesthesia care unit (PACU), 2, 6, 12, and 24 h after surgery. The time of PACU retention, postoperative ambulation, first intestine venting and discharge were recorded. The dosage of propofol and remifentanil, the frequency of sufentanil used, the incidence of postoperative nausea and vomiting were also recorded. Patient satisfaction was evaluated by using Simple Restoration Quality Score (QoR-9). Results: BIS values before and after laryngeal mask implantation in lidocaine group were 50.50±3.47 and 54.63±1.25 respectively, which was lower than those in control group(54.30±4.78, 55.80±2.33; t=3.542, 2.423, all P<0.05). The VAS score at postoperation immediately, PACU 30 min, postoperative 2, 6, 12 h in lidocaine group were 2.76±0.97, 2.37±0.93, 2.10±1.12, 1.76±0.97, 1.20±0.76 respectively, which was lower than those in control group (3.83±1.34, 3.27±1.26, 3.06±1.20, 2.63±0.88, 1.90±0.84; t=3.528, 3.154, 3.217, 3.603, 3.372, all P<0.05 ). The frequency of additional sufentanil at postoperation immediately and PACU 30 min in lidocaine group was 5(17%), 3(10%), which were less than those in control group(12(40%), 9(30%); χ(2)=4.022, 3.950, all P<0.05). The dosage of propofol and remifentanil in lidocaine group were (4.33±0.75) mg·kg(-1)·h(-1) and (9.00±1.66) μg·kg(-1)·h(-1) respectively, which were less than those in control group ((5.20±1.39) mg·kg(-1)·h(-1) and (10.43±2.20) μg·kg(-1)·h(-1;) t= 2.982, 2.842, all P<0.05). The time of PACU retention, postoperative ambulation and first intestine venting were (39.90 ± 8.06) min, (11.93±1.68) h and (10.16±1.05) h respectively in lidocaine group, which were shorter than those in control group ((48.23±10.04) min, (13.16±1.58) h and (11.13±1.30) h; t=3.514, 2.931, 3.156, all P<0.05). The QoR-9 score in lidocaine group was 15.60±1.07, which was higher than that in control group(14.73±0.74, t=-3.649, P<0.05). There was no significant difference in the incidence of postoperative nausea/vomiting and the discharge time between two groups (all P>0.05). Conclusion: Intravenous infusion of lidocaine can effectively reduce the dosages of propofol and remifentanil, postoperative early VAS score, postoperative ambulation time and first intestine venting time which could improve the satisfaction of patients.

[Analysis of the therapeutic effects of different treatment modalities on the outcomes of 87 patients with lung oligometastasis from nasopharyngeal carcinoma after radiotherapy]

OBJECTIVE

The aim of the present study was to evaluate the efficacy of three different modalities in treatment of lung oligometastases from nasopharyngeal carcinoma (NPC) after radiotherapy and to identify a more appropriate treatment modality.

METHODS

The clinical data of 87 cases of lung oligometastases from NPC were analyzed retrospectively. Among them, 33 patients underwent local small-field irradiation+ /- chemotherapy, 28 underwent whole-lung irradiation+ chemotherapy, and 26 underwent simple chemotherapy. The survival rates were calculated using Kaplan-Meier analysis. The differences among the modalities were evaluated using the log-rank test. Cox univariate and multivariate analyses were performed to determine the influencing factors.

RESULTS

The 3-year lung metastasis survival (LMS) rates of patients with lung metastasis undergoing the three treatment modalities (local small-field irradiation+ /-chemotherapy, whole-lung irradiation+ chemotherapy and chemotherapy alone) were 89.3%, 72.7%, and 72.4%, respectively, showing a significant difference between the groups (P=0.003). Further subgroup analysis showed that the 5-year LMS rate was significantly higher in the local small-field irradiation+ /-chemotherapy group than that in the whole-lung irradiation+ chemotherapy group and chemotherapy alone group (P=0.001). The 2-year progression-free survival (PFS) rates of the three groups were 57.1%, 25.8% and 3.8%, respectively, showing significant intergroup differences (P=0.002 and P<0.001). Multivariate analysis indicated that compared with the whole lung irradiation group and the chemotherapy alone group, the local irradiation+ /- chemotherapy is an independent favorable prognostic factor for LMS and PFS (P<0.05).

CONCLUSION

Local radiotherapy combined with systemic chemotherapy is the best therapeutic modality for lung oligometastases derived from NPC after radiotherapy, improving the LMS and prolonging the PFS.

[One-stage tympanic cavity ventilation tube placement in canal wall down tympanomastoidectomy]

Objective:To research the clinical application of tympanic cavity ventilation tube placement in canal wall down tympanomastoidectomy. Method:There were 52 patients with otitis media received canal wall down tympanomastoidectomy. We placed ventilation tube in posterior hypotympanum during the surgery. After surgery, all patients were followed up in 12 days, 1 month, 2 months, 6 months, and 1 year. The ventilation tubes were withdrew 6 months later, and then the hearing level and tympanic cavity status was evaluated after another half year. Result:All cases were followed up at least 1 year after surgery. Forty-four patients' tubes were removed 6 months later, but other 8 tubes had been extruded within 1 to 3 months. After 1 year, all 52 cases of ears were dry; 39 patients' tympanic membranes were stable, the postoperative complications included tympanic membrane retraction in 7 cases, middle ear effusion in 4 cases, and tympanic membrane perforation at anterior-inferior quadrant in 2 cases; CT examination indicated that 39 patients' aeration between tympanic cavity and Eustachian tube bony portion was normal, 9 patients' tympanic cavity aeration was smaller, and 4 patients' cavity was obstructed; 52 patients' average air conduction thresholds were 12.5 dB lower than that of preoperation. Conclusion:One-stage tympanic cavity ventilation tube placement is a simple, safe and effective method in canal wall down tympanomastoidectomy for middle ear diseases with Eustachian tube severe stenosis or obstruction in bony portion.

Deciphering the spectrum of somatic mutations in the entire mitochondrial DNA genome

The mitochondrion is a crucial intracellular organelle responsible for regulating cellular energy metabolism, producing free radicals, initiating and executing the apoptotic pathways. Previous studies have shown that somatic mutations in mitochondrial DNA are associated with various tumors, which may be involved during carcinogenesis and tumor progression. To examine the mutation pattern in cancer, 625 reported somatic mutations in the mitochondrial DNA genome were analyzed. We found that, except for deletions and insertions, most somatic mutations were point mutations, accounting for 89.44% of somatic mutations. Transition was the predominant form of somatic mutation in the entire mitochondrial DNA genome, accounting for 87.12% of point mutations, most of which were homoplastic. Frequency statistics analysis of point mutations indicated that, except for 3 tRNA genes, the mutations were distributed on all resting genes and in the D-loop region, with the latter showing the highest frequency of somatic mutation (19.34%), followed by the tRNA leucine 2 gene and non-coding regions between base pairs 5892 and 5903, while 13 coding-region genes and 2 rRNA genes showed a relatively lower frequency of somatic point mutations. Nonsynonymous mutations and terminal amino acid changes were the primary point somatic mutations detected from 13 coding-region genes, which may cause mitochondrial dysfunction in cancer cells. We found that the somatic mutations may affect the mitochondrial DNA genome; the non-coding region should be examined to identify somatic mutations as potential diagnostic biomarkers for early detection of cancer.

Genetic variations in MOV10 and CACNB2 are associated with hypertension in a Chinese Han population

Human hypertension is a complex, multifactorial disease. Multiple variants associated with hypertension have been identified in the large numbers of genome-wide association studies, meta-analysis, and case-control studies. The present study investigated the association between the single nucleotide polymorphisms (SNPs) of five candidate genes and the susceptibility and prognosis of hypertension in a Chinese Han population. A hospital-based case-control study in a Chinese Han population was carried out, including 500 hypertension patients and 506 healthy controls. The five SNP markers were detected using the Sequenom MassArray(®) iPLEX System. The association of genotypes with susceptibility to hypertension was analyzed using odds ratio, with 95% confidence interval and logistic regression. All five variants conformed to Hardy-Weinberg proportions in the controls. No significant differences were noted in the genotype distributions for AGTR1, PRRC2A, and CALCA polymorphisms in patients with hypertension (N = 500) and healthy controls (N = 506). SNP rs2932538, a variant in MOV10, was found to be significantly associated with an increased risk of hypertension. However, SNP rs4373814, a variant in CACNB2, showed a relevant association with a decreased risk of hypertension. In conclusion, the results of our case-control study confirmed the significant association of the SNP rs2932538 in MOV10 and SNP rs4373814 in CACNB2 with an increased risk of hypertension in a Chinese Han population, suggesting that the SNP rs2932538 may be a poor prognostic indicator for hypertension, while SNP rs4373814 may be a good prognostic indicator for hypertension in the same region. However, our findings need to be replicated in larger epidemiological and functional studies.

Effects of maturity stages on the nutritive composition and silage quality of whole crop wheat

The changes in yields and nutritive composition of whole crop wheat (Triticum aestivum L.) during maturation and effects of maturity stage and lactic acid bacteria (LAB) inoculants on the fermentation quality and aerobic stability were investigated under laboratory conditions. Whole crop wheat harvested at three maturation stages: flowering stage, milk stage and dough stage. Two strains of LAB (Lactobacillus plantarum: LAB1, Lactobacillus parafarraqinis: LAB2) were inoculated for wheat ensiling at 1.0×10⁵ colony forming units per gram of fresh forage. The results indicated that wheat had higher dry matter yields at the milk and dough stages. The highest water-soluble carbohydrates content, crude protein yields and relative feed value of wheat were obtained at the milk stage, while contents of crude fiber, neutral detergent fiber and acid detergent fiber were the lowest, compared to the flowering and dough stages. Lactic acid contents of wheat silage significantly decreased with maturity. Inoculating homofermentative LAB1 markedly reduced pH values and ammonia-nitrogen (NH₃-N) content (p<0.05) of silages at three maturity stages compared with their corresponding controls. Inoculating heterofermentative LAB2 did not significantly influence pH values, whereas it notably lowered lactic acid and NH₃-N content (p<0.05) and effectively improved the aerobic stability of silages. In conclusion, considering both yields and nutritive value, whole crop wheat as forage should be harvested at the milk stage. Inoculating LAB1 improved the fermentation quality, while inoculating LAB2 enhanced the aerobic stability of wheat silages at different maturity stages.

Differentiation between brain glioblastoma multiforme and solitary metastasis: qualitative and quantitative analysis based on routine MR imaging

BACKGROUND AND PURPOSE

The differentiation between cerebral GBM and solitary MET is clinically important and may be radiologically challenging. Our hypothesis is that routine MR imaging with qualitative and quantitative analysis is helpful for this differentiation.

MATERIALS AND METHODS

Forty-five GBM and 21 solitary metastases were retrospectively identified, with their preoperative routine MR imaging analyzed. According to the comparison of the area of peritumoral T2 prolongation with that of the lesion, the tumors were classified into grade I (prolongation area ≤ tumor area) and grade II (prolongation area > tumor area). The signal intensities of peritumoral T2 prolongation were measured on T2WI and normalized to the values of the contralateral normal regions by calculating the ratios. The ratio (nSI) of both types of tumors was compared in grade I, grade II, and in tumors without grading. The best cutoff values to optimize the sensitivity and specificity were determined for optimal differentiation.

RESULTS

The nSI of GBM was significantly higher than that of MET without T2 prolongation grading (P < .001), resulting in AUC = 0.725. The difference was significant (P = .014) in grade I tumors (GBM, 38; MET, 9), with AUC = 0.741, and in grade II tumors (GBM, 7; MET, 12), with AUC = 0.869 (P = .017). Both types of tumors showed a different propensity in T2 prolongation grading (χ(2) = 12.079, P = .001).

CONCLUSIONS

Combined with qualitative and quantitative analysis of peritumoral T2 prolongation, routine MR imaging can help in the differentiation between brain GBM and solitary MET.

Low-dose ropivacaine-sufentanil spinal anaesthesia for caesarean delivery: a randomised trial

BACKGROUND

It is well known that intrathecal opioids have a synergic effect with spinal local anaesthetics. The aim of this study was to evaluate whether low-dose ropivacaine in combination with sufentanil could produce effective spinal anaesthesia with less maternal hypotension and vomiting than ropivacaine alone.

METHODS

80 ASA I and II parturients undergoing elective caesarean delivery under combined spinal-epidural anaesthesia were randomly allocated to two groups. Group R15 received intrathecal hyperbaric ropivacaine 15 mg and group SR10 hyperbaric ropivacaine 10 mg with sufentanil 5 micrograms. Characteristics, efficacy and side effects of spinal anaesthesia in each group were measured.

RESULTS

There was no significant difference in the quality of intraoperative analgesia and muscle relaxation between groups. The incidence of hypotension was significantly higher (55% vs. 20%, P < 0.005) and the need for ephedrine less in group R15 than in group SR10. In group SR10, the onset of motor block was delayed (2.9 +/- 1.1 vs. 4.6 +/- 2.5 min, P < 0.005), the duration was shorter (65.9 +/- 15.1 vs. 125.4 +/- 26.4 min, P < 0.005). The duration of effective analgesia was longer (260 +/- 32.5 vs. 143 +/- 22.1 min, P < 0.005), the incidence of shivering (20% vs. 60%, P < 0.005) and vomiting (5% vs. 30%, P < 0.005) were lower in group SR10.

CONCLUSIONS

The combination of hyperbaric ropivacaine 10 mg with sufentanil 5 lg produced effective spinal anaesthesia for caesarean delivery with significantly less hypotension, vomiting and shivering, shorter duration of motor blockade and longer lasting analgesia than hyperbaric ropivacaine 15 mg.

Molecular variability of five Cucumber mosaic virus isolates from China

Cucumber mosaic virus (CMV) isolates are currently divided into two main groups, I and II according to their genomic sequences. The group I is further divided into two subgroups IA and IB. We performed a phylogenetic analysis of the genome regions containing 1a, 2a, 2b, coat protein (CP), and movement protein (MP) genes of 5 CMV isolates from China and other 28 CMV isolates available in the GenBank. The results indicated that CMV isolates could be genetically divided into three groups I, II, and III according to the genes encoding MP, CP, 1a, and 2a proteins and to the 2 groups according to the gene 2b. Group I could be further divided into two subgroups (IA and IB) according to the genes encoding CP, MP, 2a, and 2b proteins and to the three subgroups (IA, IB, and IC) according to the gene encoding 1a protein. Four of 5 examined Chinese CMV isolates belonged to the subgroup IB, while the remaining isolate was a natural inter-subgroup reassortant. We found that the 2b gene of CMV was under positive selection, while the other genes were under negative selection. No evidence of the selection associated with a host adaptation or geographic distribution was found.

[Studies on chemical constituents of Gaultheria leucocarpa var. Yunnanensis (Franch.) T. Z. Hsu & R. C. Fang]

OBJECTIVE

To separate and identify the chemical constituents of the aerial part of Gaultheria leucocarpa var. yunnanensis.

METHOD

The compounds were extracted with solvents, isolated by column chromatography and identified by spectral analysis.

RESULT

Four compounds were identified as n-dotriacontane and its homologous compound(1), ursolic acid(2), vanillic acid(3), and quercitrin(4).

CONCLUSION

The compounds 1, 4 were obtained from the plant for the first time, and 2 and 3 were from above-ground part of the plant for the first time.

[Changes of human recombination bone morphogenetic protein-2 in bone and marrow in tail suspended rats]

OBJECTIVE

To study human recombination bone morphogenetic protein-2 (rhBMP-2) change in bone and marrow under simulated weightlessness.

METHOD

5 SD rats were tail suspended for 14, 28 d with another 5 freely active rats as control. Histological samples were in situ hybridized.

RESULT

rhBMP-2 expression of bone and marrow were lower in tail suspended rats than control levels (P < 0.05). rhBMP-2 expression tail suspended rats in 14 day were higher than that in 28 day suspended group (P < 0.05).

CONCLUSION

rhBMP-2 levels in rats bone and marrow were lower after tail suspension.

Cubic aluminum silicides RE8Ru12Al49Si9(Al(x)Si12-x) (RE = Pr, Sm) from liquid aluminum. Empty (Si,Al)12 cuboctahedral clusters and assignment of the Al/Si distribution with neutron diffraction

Two new quaternary aluminum silicides, RE8Ru12Al49Si9(Al(x)Si12-x) (x approximately 4; RE = Pr, Sm), have been synthesized from Sm (or Sm2O3), Pr, Ru, and Si in molten aluminum between 800 and 1000 degrees C in sealed fused silica tubes. Both compounds form black shiny crystals that are stable in air and NaOH. The Nd analog is also stable. The compounds crystallize in a new structural type. The structure, determined by single-crystal X-ray diffraction, is cubic, space group Pm3m with Z = 1, and has lattice parameters of a = 11.510(1) A for Sm8Ru12Al49Si9(Al(x)Si12-x) and a = 11.553(2) A for Pr8Ru12Al49Si9(Al(x)Si12-x) (x approximately 4). The structure consists of octahedral units of AlSi6, at the cell center, Si2Ru4Al8 clusters, at each face center, SiAl8 cubes, at the middle of the cell edges, and unique (Al,Si)12 cuboctohedral clusters, at the cell corners. These different structural units are connected to each other either by shared atoms, Al-Al bonds, or Al-Ru bonds. The rare earth metal atoms fill the space between various structural units. The Al/Si distribution was verified by single-crystal neutron diffraction studies conducted on Pr8Ru12Al49Si9(Al(x)Si12-x). Sm8Ru12Al49Si9(Al(x)Si12-x) and Pr8Ru12Al49Si9(Al(x)Si12-x) show ferromagnetic ordering at Tc approximately 10 and approximately 20 K, respectively. A charge of 3+ can be assigned to the rare earth atoms while the Ru atoms are diamagnetic.

[cDNA cloning and sequence analysis of human lactoferrin]

Human lactoferrin (hLF) cDNA was amplified by RT-PCR from normal human mammary tissue obtained from Daxing County of Beijing City of China, and then subcloned into pGEM-T vector. hLF cDNA sequence was determined, which consists of 2136 bp. Comparison with five other hLF cDNA sequences registered in GenBank shows 99% homology in DNA sequence. However, there are two base substitutions (nucleotide 1740 G-->C, nucleotide 1756 T-->C), one of which subsequently leads to an amino acid change (residue 580 Glu-->Asp).

Transport function of the naturally occurring pathogenic polycystin-2 mutant, R742X

Most patients with autosomal dominant polycystic kidney disease (ADPKD) harbor mutations truncating polycystin-1 (PC1) or polycystin-2 (PC2), products of the PKD1 and PKD2 genes, respectively. A third member of the polycystin family, polycystin-L (PCL), was recently shown to function as a Ca(2+)-modulated nonselective cation channel. More recently, PC2 was also shown to be a nonselective cation channel with comparable properties to PCL, though the membrane targeting of PC2 likely varies with cell types. Here we show that PC2 expressed heterologously in Xenopus oocytes is targeted to intracellular compartments. By contrast, a truncated form of mouse PC2 corresponding to a naturally occurring human mutation R742X is targeted predominantly to the plasma membrane where it mediates K(+), Na(+), and Ca(2+) currents. Unlike PCL, the truncated form does not display Ca(2+)-activated transport activities, possibly due to loss of an EF-hand at the C-terminus. We propose that PC2 forms ion channels utilizing structural components which are preserved in the R742X form of the protein. Implications for epithelial cell signaling are discussed.

[Cloning and expression of nisZ gene in Lactococcus lactis]

The gene encoding the precursor of nisin was amplified by PCR using the lambda HJ-3 DNA as the template, which contained the entire nisin biosynthesis gene cluster from Lactococcus lactis AL2 with high yield of nisin, and was cloned into pMG36e. The recombinant plasmid pHJ201 was introduced into Lactococcus lactis NZ9800 by electroporation. pHJ201 is very stable in L. lactis NZ9800. Antimicrobial activity test and Tricine-SDS-PAGE analysis revealed that L. lactis NZ9800 harbouring pHJ201 restored ability of nisin production, but the production level was markedly lower than L. lactis AL2. The result of DNA sequence analysis indicated that Nisin Z is produced by L. lactis AL2.

[Screening of anti-bacteria activity of extracts of Gaultheria leucocarpa var. yunnanensis]

OBJECTIVE

To further develop Gaultheria leucocarpa var. yunnanensis, anti-bacteria constituents in it were screened.

METHOD

The constituents were extracted by chromatographic process. The anti-bacteria test was made with regulatory method of analysis.

RESULT AND CONCLUSION

Anti-bacteria test with extracts of water, acetic ester and n-butanol showed that 3 extracts from 22 samples had anti-Staphylococcus aureus action, and the extracts from root and stem showed the same result. 2 extracts could kill Escherichia coli and Pseudomonas aeruginosa. The lower the concentrate, the less the anti-bacteria action was. These results suggested that not only essential oil but other ingredients from G. leucocarpa var.yunnanensis have anti-bacteria activity. Anti-fungi test of the same extracts didn't indicate remarkable action.

Polycystin-2 is a novel cation channel implicated in defective intracellular Ca(2+) homeostasis in polycystic kidney disease

Mutations in polycystins-1 and -2 (PC1 and PC2) cause autosomal dominant polycystic kidney disease (ADPKD), which is characterized by progressive development of epithelial renal cysts, ultimately leading to renal failure. The functions of these polycystins remain elusive. Here we show that PC2 is a Ca(2+)-permeable cation channel with properties distinct from any known intracellular channels. Its kinetic behavior is characterized by frequent transitions between closed and open states over a wide voltage range. The activity of the PC2 channel is transiently increased by elevating cytosolic Ca(2+). Given the predominant endoplasmic reticulum (ER) location of PC2 and its unresponsiveness to the known modulators of mediating Ca(2+) release from the ER, inositol-trisphosphate (IP(3)) and ryanodine, these results suggest that PC2 represents a novel type of channel with properties distinct from those of the other Ca(2+)-release channels. Our data also show that the PC2 channel can be translocated to the plasma membranes by defined chemical chaperones and proteasome modulators, suggesting that in vivo, it may also function in the plasma membrane under specific conditions. The sensitivity of the PC2 channel to changes of intracellular Ca(2+) concentration is deficient in a mutant found in ADPKD patients. The dysfunction of such mutants may result in defective coupling of PC2 to intracellular Ca(2+) homeostasis associated with the pathogenesis of ADPKD.

[Studies on resources of ethnomedicine Gaultheria leucocarpa var. yunnanensis]

OBJECTIVE

To study the resources of G. leucocarpa var. yunnanensis for further development of this drug.

METHOD

Field investigating, consulting with relevant experts and looking into available specimens.

RESULTS AND CONCLUSION

G. leucocarpa var. yunnanensis is widely distributed in the southern regions of the Yangtze River. The field investigation suggests that the distribution center is situated in Yunnan province, mainly in Kunming, Chuxiong and Dali counties. The climate in these areas is moderate and moist. G. leucocarpa var. yunnanensis is not a dominant species in this natural environment. In some places, it grows with other species of Gaultheria, such as G. fragrantissima, G. tetramera, G. griffithiana and G. leucocarpa var. cumingiana. It is distributed at altitudes from 400 m to 3,500 m. Accustomed to different sunshine conditions, G. leucocarpa var. yunnanensis prefers stronger sunlight and commonly grows on sunny slopes, seldom in dense forest, propagating itself by roots. As a folk medicine, G. leucocarpa var. yunnanensis is commonly used to treat rheumatic arthritis(RA), dazzling, suppressed menstruation, cold, cough, asthma, strain hematemesis, eczema, ascites, wound, amebic dysentery, acute and chronic prostatitis. It is suggested that further pharmacological and clinical researches of this plant be concentrated on the treatment of RA and relief of aches.

Molecular identification and characterization of novel human and mouse concentrative Na+-nucleoside cotransporter proteins (hCNT3 and mCNT3) broadly selective for purine and pyrimidine nucleosides (system cib)

The human concentrative (Na(+)-linked) plasma membrane transport proteins hCNT1 and hCNT2 are selective for pyrimidine nucleosides (system cit) and purine nucleosides (system cif), respectively. Both have homologs in other mammalian species and belong to a gene family (CNT) that also includes hfCNT, a newly identified broad specificity pyrimidine and purine Na(+)-nucleoside symporter (system cib) from the ancient marine vertebrate, the Pacific hagfish (Eptatretus stouti). We now report the cDNA cloning and characterization of cib homologs of hfCNT from human mammary gland, differentiated human myeloid HL-60 cells, and mouse liver. The 691- and 703-residue human and mouse proteins, designated hCNT3 and mCNT3, respectively, were 79% identical in amino acid sequence and contained 13 putative transmembrane helices. hCNT3 was 48, 47, and 57% identical to hCNT1, hCNT2, and hfCNT, respectively. When produced in Xenopus oocytes, both proteins exhibited Na(+)-dependent cib-type functional activities. hCNT3 was electrogenic, and a sigmoidal dependence of uridine influx on Na(+) concentration indicated a Na(+):uridine coupling ratio of at least 2:1 for both hCNT3 and mCNT3 (cf 1:1 for hCNT1/2). Phorbol myristate acetate-induced differentiation of HL-60 cells led to the parallel appearance of cib-type activity and hCNT3 mRNA. Tissues containing hCNT3 transcripts included pancreas, bone marrow, trachea, mammary gland, liver, prostate, and regions of intestine, brain, and heart. The hCNT3 gene mapped to chromosome 9q22.2 and included an upstream phorbol myristate acetate response element.

[Fusion expression of a peptide antibiotic-apidaecin gene in Lactococcus lactis]

The ubiquitin fusion of apidaecin was expressed in Lactococcus lactis, using a novel nisin-inducible expression system. After induction, a specific band could be detected in the extracts of the host strain by Tricine-SDS-PAGE and Western blotting. Production of the fusion was up to 7.2% of the total soluble protein of the host strain. While the fusion was cut by ubiquitin specific protease-UBP1, the product had distinct antibacterial activity.

Human calcium transport protein CaT1

Transcellular calcium transport occurs in many epithelial tissues including intestine, kidney, and placenta. We identified the human ortholog (hCaT1) of a recently cloned rat calcium transport protein, CaT1, that mediates intestinal calcium uptake. hCaT1 messenger RNA is present in the gastrointestinal tract, including esophagus, stomach, duodenum, jejunum, ileum, and colon. High levels of hCaT1 transcripts are also present in pancreas, placenta, prostate, and salivary gland, while moderate levels are present in liver, kidney, and testis. hCaT1 mRNA is also expressed in the colorectal cancer cell line, SW480, and the chronic myelogenous leukemia cell line, K-562. The hCaT1 gene was assigned to the long arm of chromosome 7, bands q33-34, by fluorescence in situ hybridization. When expressed in Xenopus laevis oocytes, hCaT1 promotes saturable Ca(2+) uptake with a Michaelis constant of 0.25 mM. Our studies suggest a role for hCaT1 in cellular calcium uptake in a variety of tissues, including the transcellular calcium transport pathway in intestine.

A rat kidney-specific calcium transporter in the distal nephron

Active absorption of calcium from the intestine and reabsorption of calcium from the kidney are major determinants of whole body calcium homeostasis. Two recently cloned proteins, CaT1 and ECaC, have been postulated to mediate apical calcium uptake by rat intestine and rabbit kidney, respectively. By screening a rat kidney cortex library with a CaT1 probe, we isolated a cDNA encoding a protein (CaT2) with 84.2 and 73.4% amino acid identities to ECaC and CaT1, respectively. Unlike ECaC, CaT2 is kidney-specific in the rat and was not detected in intestine, brain, adrenal gland, heart, skeletal muscle, liver, lung, spleen, thymus, and testis by Northern analysis or reverse transcription polymerase chain reaction. The expression pattern of CaT2 in kidney was similar to that of calbindin D(28K) and the sodium calcium exchanger 1, NCX1, by in situ hybridization of adjacent sections. Furthermore, the mRNAs for CaT2 and calbindin D(28K) were colocalized in the same cells. CaT2 mediated saturable calcium uptake with a Michaelis constant (K(m)) of 0.66 mm when expressed in Xenopus laevis oocytes. Under voltage clamp condition, CaT2 promoted inward currents in X. laevis oocytes upon external application of Ca(2+). Sr(2+) and Ba(2+) but not Mg(2+) also evoked inward currents in CaT2-expressing oocytes. Similar to the alkaline earth metal ions, application of Cd(2+) elicited inward current in CaT2-expressing oocytes with a K(m) of 1.3 mm. Cd(2+), however, also potently inhibited CaT2-mediated Ca(2+) uptake with an IC(50) of 5.4 micrometer. Ca(2+) evoked currents were reduced at low pH and increased at high pH and were only slightly affected by the L-type voltage-dependent calcium channel antagonists, nifedipine, verapamil, diltiazem, and the agonist, Bay K 8644, even at relatively high concentrations. In conclusion, CaT2 may participate in calcium entry into the cells of the distal convoluted tubule and connecting segment of the nephron, where active reabsorption of calcium takes place via the transcellular route. The high sensitivity of CaT2 to Cd(2+) also provides a potential explanation for Cd(2+)-induced hypercalciuria and resultant renal stone formation.

Functional roles of histidine and tyrosine residues in the H(+)-peptide transporter PepT1

Histidyl residues in peptide transporters PepT1 and PepT2 are believed to participate in proton and substrate binding and to be crucial to the transporters' functional activities. In the present study, we performed mutagenesis of rabbit PepT1. We mutated three histidine residues (H57, H111, and H121) predicted to reside in transmembrane segments, as well as tyrosine residues adjacent to H57. Functional analysis of wild-type and mutant PepT1 expressed in Xenopus oocytes, using both the radiotracer methods and two-microelectrode voltage-clamping, revealed that not only the H57 but also the aromatic residues near H57 were essential for the normal function of PepT1, in agreement with the concept that aromatic residues stabilize the charge on H(+) when interacting with H57. While mutagenesis at H111 did not significantly affect the activity of PepT1, mutagenesis at H121 had profound implications. The substrate affinities for H121 mutants were decreased depending both on the charge of the substrate and the charge on the substituted residues at position 121. We propose that H57 and H121 are intimately involved in the binding of the coupling ion H(+) and the recognition of transportable peptide substrates, respectively.

Differential recognition of ACE inhibitors in Xenopus laevis oocytes expressing rat PEPT1 and PEPT2

PURPOSE

To examine the mechanism of inhibition of glycylsarcosine (GlySar) transport by quinapril and enalapril, and whether or not angiotensin converting enzyme (ACE) inhibitors are transported by PEPT2 as well as by PEPT1.

METHODS

Xenopus laevis oocytes were cRNA-injected with rat PEPT1 or PEPT2 and the transport kinetics of radiolabeled GlySar were studied in the absence and presence of quinapril and enalapril. The two-microelectrode voltage-clamp technique was also performed to probe the electrogenic uptake of captopril, quinapril and enalapril.

RESULTS

Kinetic analyses demonstrated that quinapril inhibited the uptake of GlySar in a noncompetitive manner in Xenopus oocytes injected with PEPT1 or PEPT2 (Ki = 0.8 or 0.4 mM, respectively). In contrast, a competitive interaction was observed between GlySar and enalapril (Ki = 10.8 mM for PEPT1 or 4.3 mM for PEPT2). Most significantly, captopril and enalapril, but not quinapril, induced inwardly-directed currents in both PEPT1- and PEPT2-expressed oocytes.

CONCLUSIONS

These results are unique in providing direct evidence for the substrate recognition and transport of some ACE inhibitors by the high- and low-affinity oligopeptide transporters. Our findings point to differences between PEPT1 and PEPT2 in their affinity to, rather than in their specificity for, ACE inhibitors.

[HLA-DQ molecules associated with myasthenia gravis in Chinese patients]

Myasthenia Gravis (MG) is an autoimmune disease which is a neuromuscular disorder of autoimmune origin. MG in different races or ethnic groups has different genetic susceptibility. To search for the associations of MG in the Chinese patients with HLA-DQ molecules, PCR-RFLP method was employed for genotyping HLA-DQA1 and -DQB1 genes of MG patients and the normal Chinese. The distributions of alleles of DQA1 and DQB1 in the normal Chinese and the MG patients were listed. The DQB allele, DQB1 * 0302 was positively associated with MG (RR = 2.990, Pc = 0.0307), and a negative association was found for DQA1 * 0501 (RR = 0.4166, Pc = 0.0315). DQ haplotype DQA1 * 0301-DQB1 * 0302 was significantly increased in patients when compared to controls (RR = 7.727, Pc = 0.0109).

Yeast SMF1 mediates H(+)-coupled iron uptake with concomitant uncoupled cation currents

Yeast membrane proteins SMF1, SMF2, and SMF3 are homologues of the DCT1 metal ion transporter family. Their functional characteristics and the implications of these characteristics in vivo have not yet been reported. Here we show that SMF1 expressed in Xenopus oocytes mediates H(+)-dependent Fe(2+) transport and uncoupled Na(+) flux. SMF1-mediated Fe(2+) transport exhibited saturation kinetics (K(m) = 2.2 microM), whereas the Na(+) flux did not, although both processes were electrogenic. SMF1 is also permeable to Li(+), Rb(+), K(+), and Ca(2+), which likely share the same uncoupled pathway. SMF2 (but not SMF3) mediated significant increases in both Fe(2+) and Na(+) transport compared with control oocytes. These data are consistent with the concept that uptake of divalent metal ions by SMF1 and SMF2 is essential to yeast cell growth. Na(+) inhibited metal ion uptake mediated by SMF1 and SMF2 expressed in oocytes. Consistent with this, we found that increased sensitivity of yeast to EGTA in the high Na(+) medium is due to inhibition of SMF1- and SMF2-mediated metal ion transport by uncoupled Na(+) pathway. Interestingly, DCT1 also mediates Fe(2+)-activated uncoupled currents. We propose that uncoupled ion permeabilities in metal ion transporters protect cells from metal ion overload.

Polycystin-L is a calcium-regulated cation channel permeable to calcium ions

Polycystic kidney diseases are genetic disorders in which the renal parenchyma is progressively replaced by fluid-filled cysts. Two members of the polycystin family (polycystin-1 and -2) are mutated in autosomal dominant polycystic kidney disease (ADPKD), and polycystin-L is deleted in mice with renal and retinal defects. Polycystins are membrane proteins that share significant sequence homology, especially polycystin-2 and -L (50% identity and 71% similarity). The functions of the polycystins remain unknown. Here we show that polycystin-L is a calcium-modulated nonselective cation channel that is permeable to sodium, potassium and calcium ions. Patch-clamp experiments revealed single-channel activity with a unitary conductance of 137 pS. Channel activity was substantially increased when either the extracellular or intracellular calcium-ion concentration was raised, indicating that polycystin-L may act as a transducer of calcium-mediated signalling in vivo. Its large single-channel conductance and regulation by calcium ions distinguish it from other structurally related cation channels.

Molecular cloning and characterization of a channel-like transporter mediating intestinal calcium absorption

Calcium is a major component of the mineral phase of bone and serves as a key intracellular second messenger. Postnatally, all bodily calcium must be absorbed from the diet through the intestine. Here we report the properties of a calcium transport protein (CaT1) cloned from rat duodenum using an expression cloning strategy in Xenopus laevis oocytes, which likely plays a key role in the intestinal uptake of calcium. CaT1 shows homology (75% amino acid sequence identity) to the apical calcium channel ECaC recently cloned from vitamin D-responsive cells of rabbit kidney and is structurally related to the capsaicin receptor and the TRP family of ion channels. Based on Northern analysis of rat tissues, a 3-kilobase CaT1 transcript is present in rat duodenum, proximal jejunum, cecum, and colon, and a 6.5-kilobase transcript is present in brain, thymus, and adrenal gland. In situ hybridization revealed strong CaT1 mRNA expression in enterocytes of duodenum, proximal jejunum, and cecum. No signals were detected in kidney, heart, liver, lung, spleen, and skeletal muscle. When expressed in Xenopus oocytes, CaT1 mediates saturable Ca(2+) uptake with a Michaelis constant of 0.44 mM. Transport of Ca(2+) by CaT1 is electrogenic, voltage-dependent, and exhibits a charge/Ca(2+) uptake ratio close to 2:1, indicating that CaT1-mediated Ca(2+) influx is not coupled to other ions. CaT1 activity is pH-sensitive, exhibiting significant inhibition by low pH. CaT1 is also permeant to Sr(2+) and Ba(2+) (but not Mg(2+)), although the currents evoked by Sr(2+) and Ba(2+) are much smaller than those evoked by Ca(2+). The trivalent cations Gd(3+) and La(3+) and the divalent cations Cu(2+), Pb(2+), Cd(2+), Co(2+), and Ni(2+) (each at 100 microM) do not evoke currents themselves, but inhibit CaT1-mediated Ca(2+) transport. Fe(3+), Fe(2+), Mn(2+), and Zn(2+) have no significant effects at 100 microM on CaT1-mediated Ca(2+) transport. CaT1 mRNA levels are not responsive to 1,25-dihydroxyvitamin D(3) administration or to calcium deficiency. Our studies strongly suggest that CaT1 provides the principal mechanism for Ca(2+) entry into enterocytes as part of the transcellular pathway of calcium absorption in the intestine.

A family of mammalian Na+-dependent L-ascorbic acid transporters

Vitamin C (L-ascorbic acid) is essential for many enzymatic reactions, in which it serves to maintain prosthetic metal ions in their reduced forms (for example, Fe2+, Cu+), and for scavenging free radicals in order to protect tissues from oxidative damage. The facilitative sugar transporters of the GLUT type can transport the oxidized form of the vitamin, dehydroascorbic acid, but these transporters are unlikely to allow significant physiological amounts of vitamin C to be taken up in the presence of normal glucose concentrations, because the vitamin is present in plasma essentially only in its reduced form. Here we describe the isolation of two L-ascorbic acid transporters, SVCT1 and SVCT2, from rat complementary DNA libraries, as the first step in investigating the importance of L-ascorbic acid transport in regulating the supply and metabolism of vitamin C. We find that SVCT1 and SVCT2 each mediate concentrative, high-affinity L-ascorbic acid transport that is stereospecific and is driven by the Na+ electrochemical gradient. Despite their close sequence homology and similar functions, the two isoforms of the transporter are discretely distributed: SVCT1 is mainly confined to epithelial systems (intestine, kidney, liver), whereas SVCT2 serves a host of metabolically active cells and specialized tissues in the brain, eye and other organs.