Hepatic perivascular epithelioid cell tumors: The importance of preoperative diagnosis

Accurate preoperative diagnosis is highly important for the treatment of perivascular epithelioid cell tumors (PEComas) because PEComas are mainly benign tumors and may not require surgical intervention. By analyzing the causes, properties and clinical manifestations of PEComas, we summarize the challenges and solutions in the diagnosis of PEComas.

[Efficacy and safety analysis of P-GemDOx regimen and stratified prognosis in patients with early extranodal NK/T cell lymphoma]

Objective: To assess the efficacy, safety, and related prognostic factors associated with the P-GemDOx regimen as a first-line treatment for patients with early-stage extranodal natural killer (NK) /T cell lymphoma (ENKTL) . Methods: A retrospective analysis was performed on sixty early-stage ENKTL patients treated with the P-GemDOx regimen who were admitted to the First Affiliated Hospital of Nanjing Medical University between August 2015 and May 2021. The Chi-square test or Fisher's exact test was used to compare group differences, and the Log-rank test was used to compare the differences in survival. Survival outcomes and prognostic factors were examined. Results: After completing 4 to 6 cycles of P-GemDOx chemotherapy, the overall response rate (ORR) was 88.3%, with forty-six patients (76.7% ) achieving complete response (CR). The 4-year progression-free survival (PFS) and overall survival (OS) rates were (66.3±7.1) % and (79.5±6.0) %, respectively. According to the PINK/PINK-E model, there was no significant difference in survival outcomes among risk groups. 23.3% of patients experienced progression of disease within 24 months (POD<24). OS estimates differed significantly (P<0.001) between the POD<24 group (n=14) and the POD≥24 group (n=46). Analysis showed that SUVmax > 12.8 at diagnosis, non-single nasal cavity infiltration, and response less than CR after 4-6 cycles all had a significant association with POD24. We used these data as the basis for predicting POD<24 international prognostic index (POD24-IPI). Patients were stratified into low-risk (no risk factors), intermediate-risk (one risk factor), or high risk (two or three risk factors). These groups were associated with 4-year OS rate of 100%, (85.6±9.7) %, and (65.0±10.2) %, respectively (P=0.014). The P-GemDOx regimen was well tolerated, with hematological toxicity being the main side effect. Conclusion: This study demonstrated that the P-GemDOx regimen is effective and safe in the first-line treatment of early-stage ENKTL, and POD24-IPI is a promising prognostic model.

Clinical study of standard residual liver volume and transient elastography in predicting poor prognosis of patients after hemihepatectomy

BACKGROUND

Liver cancer resection, especially in patients with hemihepatectomy or extended hemihepatectomy, often leads to poor prognosis, such as liver insufficiency and even liver failure and death, because the standard residual liver volume (SRLV) cannot be fully compensated after surgery.

AIM

To explore the risk factors of poor prognosis after hemihepatectomy for hepatocellular carcinoma and evaluate the application value of related prognostic approaches.

METHODS

The clinical data of 35 patients with primary liver cancer in Nantong Third People's Hospital from February 2016 to July 2020 were retrospectively analyzed. The receiver operating characteristic curve was created using medcac19.0.4 to compare the critical values of the SRLV in different stages of liver fibrosis after hemihepatectomy with those of liver dysfunction after hemihepatectomy. It was constructed by combining the Child-Pugh score to evaluate its application value in predicting liver function compensation.

RESULTS

The liver stiffness measure (LSM) value and SRLV were associated with liver dysfunction after hemihepatectomy. Logistic regression analysis showed that an LSM value ≥ 25 kPa [odds ratio (OR) = 6.254, P < 0.05] and SRLV ≤ 0.290 L/m2 (OR = 5.686, P < 0.05) were independent risk factors for postoperative liver dysfunction. The accuracy of the new liver reserve evaluation model for predicting postoperative liver function was higher than that of the Child-Pugh score (P < 0.05).

CONCLUSION

SRLV and LSM values can be used to evaluate the safety of hemihepatectomy. The new liver reserve evaluation model has good application potential in the evaluation of liver reserve function after hemihepatectomy.

[A multicenter epidemiological study of acute bacterial meningitis in children]

Objective: To analyze the clinical epidemiological characteristics including composition of pathogens , clinical characteristics, and disease prognosis acute bacterial meningitis (ABM) in Chinese children. Methods: A retrospective analysis was performed on the clinical and laboratory data of 1 610 children <15 years of age with ABM in 33 tertiary hospitals in China from January 2019 to December 2020. Patients were divided into different groups according to age,<28 days group, 28 days to <3 months group, 3 months to <1 year group, 1-<5 years of age group, 5-<15 years of age group; etiology confirmed group and clinically diagnosed group according to etiology diagnosis. Non-numeric variables were analyzed with the Chi-square test or Fisher's exact test, while non-normal distrituction numeric variables were compared with nonparametric test. Results: Among 1 610 children with ABM, 955 were male and 650 were female (5 cases were not provided with gender information), and the age of onset was 1.5 (0.5, 5.5) months. There were 588 cases age from <28 days, 462 cases age from 28 days to <3 months, 302 cases age from 3 months to <1 year of age group, 156 cases in the 1-<5 years of age and 101 cases in the 5-<15 years of age. The detection rates were 38.8% (95/245) and 31.5% (70/222) of Escherichia coli and 27.8% (68/245) and 35.1% (78/222) of Streptococcus agalactiae in infants younger than 28 days of age and 28 days to 3 months of age; the detection rates of Streptococcus pneumonia, Escherichia coli, and Streptococcus agalactiae were 34.3% (61/178), 14.0% (25/178) and 13.5% (24/178) in the 3 months of age to <1 year of age group; the dominant pathogens were Streptococcus pneumoniae and the detection rate were 67.9% (74/109) and 44.4% (16/36) in the 1-<5 years of age and 5-<15 years of age . There were 9.7% (19/195) strains of Escherichia coli producing ultra-broad-spectrum β-lactamases. The positive rates of cerebrospinal fluid (CSF) culture and blood culture were 32.2% (515/1 598) and 25.0% (400/1 598), while 38.2% (126/330)and 25.3% (21/83) in CSF metagenomics next generation sequencing and Streptococcus pneumoniae antigen detection. There were 4.3% (32/790) cases of which CSF white blood cell counts were normal in etiology confirmed group. Among 1 610 children with ABM, main intracranial imaging complications were subdural effusion and (or) empyema in 349 cases (21.7%), hydrocephalus in 233 cases (14.5%), brain abscess in 178 cases (11.1%), and other cerebrovascular diseases, including encephalomalacia, cerebral infarction, and encephalatrophy, in 174 cases (10.8%). Among the 166 cases (10.3%) with unfavorable outcome, 32 cases (2.0%) died among whom 24 cases died before 1 year of age, and 37 cases (2.3%) had recurrence among whom 25 cases had recurrence within 3 weeks. The incidences of subdural effusion and (or) empyema, brain abscess and ependymitis in the etiology confirmed group were significantly higher than those in the clinically diagnosed group (26.2% (207/790) vs. 17.3% (142/820), 13.0% (103/790) vs. 9.1% (75/820), 4.6% (36/790) vs. 2.7% (22/820), χ²=18.71, 6.20, 4.07, all P<0.05), but there was no significant difference in the unfavorable outcomes, mortility, and recurrence between these 2 groups (all P>0.05). Conclusions: The onset age of ABM in children is usually within 1 year of age, especially <3 months. The common pathogens in infants <3 months of age are Escherichia coli and Streptococcus agalactiae, and the dominant pathogen in infant ≥3 months is Streptococcus pneumoniae. Subdural effusion and (or) empyema and hydrocephalus are common complications. ABM should not be excluded even if CSF white blood cell counts is within normal range. Standardized bacteriological examination should be paid more attention to increase the pathogenic detection rate. Non-culture CSF detection methods may facilitate the pathogenic diagnosis.

[Estimation of molecular clock of Mycobacterium tuberculosis based on whole genome sequencing data]

Objective: To analyze the genomic mutation of Mycobacterium tuberculosis (M. tuberculosis) isolated in endogenous activation period and estimate the molecular clock based on the whole genome sequencing data. Methods: Literatures of the whole genome research of endogenous reactivated tuberculosis were retrieved, and the corresponding whole genome sequencing data were downloaded. We extracted the single nucleotide polymorphisms (SNPs) and strain isolation time of initial treatment and relapse of tuberculosis cases, explored the relationship between the different SNPs and interval between initial treatment and relapse by Poisson regression model, calculated the M. tuberculosis molecular clock, and estimated the mutation rate. Results: When the generation time of M. tuberculosis was 18 hours, the mutation rate in 0-2 years, i.e. short-term endogenous activation, was 6.47×10^-10 (95%CI: 5.59×10^-10-7.44×10^-10), which was significantly higher than that in 2-14 years in long term endogenous activation (3.27×10^-10, 95%CI: 2.88×10^-10-3.69×10^-10). The mutation rates of 0-, 1-, 2-, 3-, 5- and 7-14 years were 7.10×10^-10, 6.06×10^-10, 4.24×10^-10, 5.34×10^-10, 2.59×10^-10 and 1.26×10^-10 respectively. Conclusions: In the period of endogenous reactivation, the mutation rate of M. tuberculosis decreases with the interval time between initial treatment and relapse, which verifies the clinically observed phenomenon that the relapse often occurs within two years after the initial treatment of tuberculosis.

[A multicenter retrospective study on the efficacy of different anti-reflux reconstruction methods after proximal gastrectomy for gastric cancer]

Objective: To examine the clinical efficacy of 3 anti-reflux methods of digestive tract reconstruction after proximal gastrectomy for gastric cancer. Methods: The clinical data and follow-up data of gastric cancer patients who underwent anti-reflux reconstruction after proximal gastrectomy in 11 medical centers of China from September 2016 to August 2021 were retrospectively collected, including 273 males and 65 females, aging of (63±10) years (range: 28 to 91 years). Among them, 159 cases were performed with gastric tube anastomosis (GTA), 107 cases with double tract reconstruction (DTR), and 72 cases with double-flap technique (DFT), respectively. The duration of operation, length of postoperative hospital stay and early postoperative complications (referring to Clavien-Dindo classification) of different anti-reflux reconstruction methods were assessed. Body mass index, hemoglobin and albumin were used to reflect postoperative nutritional status. Reflux esophagitis was graded according to Los Angeles criteria based on the routinely gastroscopy within 12 months after surgery. The postoperative quality of life (QoL) was evaluated by Visick score system. The ANOVA analysis, Kruskal-Wallis rank sum test, χ² test and Fisher's exact test were used for comparison between multiple groups, and further comparison among groups were performed with LSD, Tamhane's test or Bonferroni corrected χ² test. The mixed effect model was used to compare the trends of Body mass index, hemoglobin and albumin over time among different groups. Results: The operation time of DFT was significantly longer than that of GTA and DTR ((352±63) minutes vs. (221±66) minutes, (352±63) minutes vs. (234±61) minutes, both P<0.01). The incidence of early complications with Clavien-Dindo grade Ⅱ to Ⅴ in GTA, DFT and DTR groups was 17.0% (27/159), 9.7% (7/72) and 10.3% (11/107), respectively, without significant difference among these three groups (χ²=3.51, P=0.173). Body mass index decreased more significantly in GTA than DFT group at 6 and 12 months after surgery (mean difference=1.721 kg/m², P<0.01; mean difference=2.429 kg/m², P<0.01). body mass index decreased significantly in DTR compared with DFT at 12 months after surgery (mean difference=1.319 kg/m², P=0.027). There was no significant difference in hemoglobin or albumin fluctuation between different reconstruction methods perioperative. The incidence of reflux esophagitis one year after surgery in DTR group was 12.9% (4/31), which was lower than that in DFT (45.9% (17/37), χ²=8.63, P=0.003). Follow-up of postoperative quality of life showed the incidence of Visick grade 2 to 4 in DFT group was lower than that in GTA group (10.4% (7/67) vs. 34.6% (27/78), χ²=11.70, P=0.018), while there was no significant difference between DFT and DTR group (10.4% (7/67) vs. 22.2% (8/36, P>0.05). Conclusions: Compared with GTA and DTR, DFT is more time-consuming, but there is no significant difference in early complications among three methods. DFT reconstruction is more conducive to maintain postoperative nutritional status and improve QoL, especially compared with GTA. The risk of reflux esophagitis after DTR reconstruction is lower than that of DFT.

[Endemic situation of schistosomiasis in Suzhou City from 2010 to 2020]

OBJECTIVE

To analyze the endemic status of schistosomiasis in Suzhou City from 2010 to 2020, so as to provide the evidence for formulating the future schistosomiasis control strategy.

METHODS

The data pertaining to the endemic status of schistosomiasis in Suzhou City from 2010 to 2020 were retrieved from the annual schistosomiasis control report, the information management platform of schistosomiasis (parasitic diseases) in Jiangsu Province and the Parasitic Diseases Control Information Management System of Chinese Center for Disease Control and Prevention, including snail survey data, snail control data and schistosomiasis examination data, and were retrospectively reviewed. Differences of proportions were tested for statistical significance with chi-square test, and the trends in proportions were evaluated using the chi-square test for trends.

RESULTS

Elimination of schistosomiasis was achieved in Suzhou City in 2018, and there were 3.528 9 million residents living in schistosomiasis-endemic villages of 81 townships in 9 counties. A total of 707 600 labor-days were used for snail survey in 11 586 village-times in Suzhou City from 2010 to 2020, covering 18 572.73 hm², and snail habitats were detected with an area of 68.61 hm², including emerging snail habitats of 37.30 hm². A total of 23 144 snails were dissected, and no Schistosoma japonicum infection was detected. Reemerging and emerging snail habitats were predominantly found in inlands. During the period from 2010 to 2020, snail control was performed in Suzhou City for 71 000 labor-times, and snail control was done covering 269.34 hm² through chemical treatment and covering 3.48 hm² through environmental improvements. A total of 674 002 person-times received serological tests for S. japonicum infections in Suzhou City from 2010 to 2020, with seroprevalence of 0.38%, and a total of 33 835 person-times received stool examinations, with no egg-positives identified. The sero-prevalence of S. japonicum infections appeared an overall tendency towards a rise in Suzhou City from 2010 to 2020 (χ² = 129.48, P < 0.001). The sero-prevalence of S. japonicum infections appeared high among local residents in 2016, and remained stable in other years, while the sero-prevalence of S. japonicum infections appeared an overall tendency towards a rise among mobile populations (χ² = 54.11, P < 0.001). There were 278 800 and 175 202 serological tests among local residents and mobile populations in Suzhou City from 2013 to 2020, and 0.50% and 0.35% sero-prevalence rates were detected, respectively. The sero-prevalence of S. japonicum infections was significantly higher among local residents than among mobile populations in Suzhou City (χ²= 54.76, P < 0.001).

CONCLUSIONS

There is a risk of rebound of schistosomiasis in Suzhou City. Integrated control should be reinforced to prevent the risk of rebound of schistosomiasis in Suzhou City.

[Construction of a nomogram prediction model for pathological complete response (pCR) of ipsilateral supraclavicular lymph node after neoadjuvant chemotherapy for breast cancer with first diagnosis of ipsilateral supraclavicular lymph node metastasis]

Objective: To develop a predictive model for pathologic complete response (pCR) of ipsilateral supraclavicular lymph nodes (ISLN) after neoadjuvant chemotherapy for breast cancer and guide the local treatment. Methods: Two hundred and eleven consecutive breast cancer patients with first diagnosis of ipsilateral supraclavicular lymph node metastasis who underwent ipsilateral supraclavicular lymph node dissection and treated in the Breast Department of Henan Cancer Hospital from September 2012 to May 2019 were included. One hundred and forty two cases were divided into the training set while other 69 cases into the validation set. The factors affecting ipsilateral supraclavicular lymph node pCR (ispCR)of breast cancer after neoadjuvant chemotherapy were analyzed by univariate and multivariate logistic regression analyses, and a nomogram prediction model of ispCR was established. Internal and external validation evaluation of the nomogram prediction model were conducted by receiver operating characteristic (ROC) curve analysis and plotting calibration curves. Results: Univariate logistic regression analysis showed that Ki-67 index, number of axillary lymph node metastases, breast pCR, axillary pCR, and ISLN size after neoadjuvant chemotherapy were associated with ispCR of breast cancerafter neoadjuvant chemotherapy (P<0.05). Multivariate logistic regression analysis showed that the number of axillary lymph node metastases (OR=5.035, 95%CI: 1.722-14.721, P=0.003), breast pCR (OR=4.662, 95%CI: 1.456-14.922, P=0.010) and ISLN size after neoadjuvant chemotherapy (OR=4.231, 95%CI: 1.194-14.985, P=0.025) were independent predictors of ispCR of breast cancer after neoadjuvant chemotherapy. A nomogram prediction model of ispCR of breast cancer after neoadjuvant chemotherapy was constructed using five factors: number of axillary lymph node metastases, Ki-67 index, breast pCR, axillary pCR and size of ISLN after neoadjuvant chemotherapy. The areas under the ROC curve for the nomogram prediction model in the training and validation sets were 0.855 and 0.838, respectively, and the difference was not statistically significant (P=0.755). The 3-year disease-free survival rates of patients in the ispCR and non-ispCR groups after neoadjuvant chemotherapy were 64.3% and 54.8%, respectively, with statistically significant differences (P=0.024), the 3-year overall survival rates were 83.8% and 70.2%, respectively, without statistically significant difference (P=0.087). Conclusions: Disease free survival is significantly improved in breast cancer patients with ispCR after neoadjuvant chemotherapy. The constructed nomogram prediction model of ispCR of breast cancer patients after neoadjuvant chemotherapy is well fitted. Application of this prediction model can assist the development of local management strategies for the ipsilateral supraclavicular region after neoadjuvant chemotherapy and predict the long-term prognosis of breast cancer patients.

[A multicenter study of the condition of children's rheumatic disease associated medical resources in Fujian province]

Objective: To investigate general condition of children's rheumatic disease associated medical resources in Fujian Province. Methods: This questionnaire-based survey was conducted in 19 hospitals in Fujian province from December 2, 2018 to May 1, 2019. The questionnaire was designed to survey the general condition of the medical resources and the hospitalization of patients with rheumatic diseases from January 1, 2014 to December 1, 2018. Results: In the 19 hospitals, there were 15 general hospitals and 4 children's hospitals, and only 5 hospitals had children's rheumatic specialist clinic. There were only 53-62 beds for rheumatic disease patients in the 19 hospitals, accounting for 1.7%-2.0% of the total inpatient beds (3 137). There are 29 pediatric rheumatologists in total, accounting for 2.6% (29/1 120) of the total pediatricians. In the past five years, 613 patients with rheumatic diseases, accounting for 0.1% (613/625 214) of total hospitalized patients, were treated in these hospitals. Among them, 201 had juvenile idiopathic arthritis, 295 had systemic lupus erythematosus, 39 had dermatomyositis, 7 had scleroderma, and 57 had inflammatory bowel disease, 9 had Sjogren's syndrome, 5 had Behcet's disease, and none had overlap syndrome or mixed connective tissue disease. Conclusion: The medical resources of children rheumatic diseases in Fujian province are insufficient which need to be developed.

[The prognostic significance of peripheral lymphocyte/monocyte ratio and PET-2 evaluation in adult Hodgkin's lymphoma]

目的

探讨淋巴细胞/单核细胞比值（LMR）及2个疗程后PET评价（PET-2）在成人霍奇金淋巴瘤（HL）中的预后价值。

方法

回顾性分析2007年1月至2016年3月南京医科大学第一附属医院133例初诊成人HL患者的临床资料。采用X-tile软件确定变量的最佳临界值，生存分析采用Kaplan-Meier法及Cox回归。

结果

133例HL患者中位年龄33（18~84）岁，男女比例1.9∶1。LMR最佳临界值为2.5，LMR<2.5组无进展生存（PFS）时间（P<0.001）和总生存（OS）时间（P<0.001）均较LMR ≥2.5组显著缩短。多因素生存分析显示LMR<2.5是HL患者PFS（HR=2.35，95%CI 1.36~4.07，P=0.002）和OS（HR=10.36，95%CI 2.35~45.66，P=0.002）的独立预后因素。56例患者的PET-2结果分析显示，PET-2阳性患者PFS明显差于PET-2阴性患者（P=0.022）。根据LMR和PET-2将患者分为PET-2阴性且LMR ≥2.5、PET-2阳性或LMR<2.5、PET-2阳性且LMR<2.5三组，三组间的PFS和OS差异均有统计学意义（P值分别为0.009和0.012）。

结论

LMR<2.5是成人HL患者的独立预后不良因素。PET-2与LMR结合的预后价值可能更好。

[Application of the five-level pediatric emergency triage system: a single center study]

Objective: To assess the effectiveness in optimizing resources and shortening critical children's waiting time in pediatric emergency department (PED) with five-level pediatric emergency triage system (PETS). Methods: This retrospective study was conducted in the First Affiliated Hospital of Xiamen University after PETS was applied. The data of patients who visited the pediatric emergency department from January 2015 to December 2017 were collected and analyzed, including age, sex, diseases, visiting time, triage rate and destination. Results: A total of 375 985 patients were included, among whom males were 225 308 (59.9%) and females were 150 677 (40.1%), all younger than 14 years of age. The number of critical cases (level Ⅰ, level Ⅱ and level Ⅲ) was increased from 4 719 (3.7%) in 2015, 12 209 (10.2%) in 2016 to 16 188 (12.7%) in 2017. The number of non-critical patients (level Ⅴ) decreased year by year, as from 98 213 (76.8%) in 2015 to 75 210 (62.6%) in 2016 and 78 857 (61.7%) in 2017. The patients who classified as level Ⅰ or levelⅡaccording to the PETS were seen immediately by physician (n=1855, 0.5%). Overall, 119 738 patients (98.3%) who were classified as level Ⅲ or level Ⅳ could be seen by physician in a timely manner according to triage guidelines, while 2 112 patients (1.7%) could not. The mean waiting time was 9.09 min in level Ⅲ, 17.7 min in level Ⅳ, and 55.76 min in level Ⅴ patients, respectively. The critical cases admitted to the intensive care units were 175 (36.2%) in 2015, 350 (62.8%) in 2016 and 374 (66.2%) in 2017. The etiologies were respiratory diseases (73.3%), gastrointestinal diseases (15.8%) and infectious diseases (3.1%). Conclusion: The application of PETS could optimize emergency resources and shorten the waiting time of critically ill children.

[Prognostic value of lymphocyte-to-monocyte ratio in angioimmunoblastic T cell lymphoma]

目的

探究淋巴细胞/单核细胞比值（LMR）在血管免疫母细胞性T细胞淋巴瘤（AITL）患者中的预后价值。

方法

回顾性分析2009年6月至2017年7月南京医科大学第一附属医院收治的64例初诊AITL患者资料。采用ROC曲线计算LMR临界值，并以此将患者分为高LMR和低LMR组，采用Pearson卡方检验及Fisher精确概率法进行组间比较。采用Kaplan-Meier法和Cox回归分析影响无进展生存（PFS）和总生存（OS）的预后因素。

结果

64例患者中，男39例，女25例，中位年龄63（29~89）岁。LMR临界值为3.07。中位随访33（5~103）个月，低LMR与高LMR组比较，患者的PFS时间（9对13个月，P=0.044）和OS时间（16个月对未达到，P=0.014）差异均有统计学意义。多因素分析显示低LMR是影响患者PFS（HR=0.48, 95% CI 0.26~0.92，P=0.027）和OS（HR=0.38，95% CI 0.18~0.82，P=0.013）的独立预后不良因素。亚组分析结果显示，在中高危至高危[非特指型预后指数（PIT）评分2~4分]患者中，低LMR者有更短的PFS和OS时间（P值分别为0.013、0.031），而在低危至中低危（PIT评分0~1分）患者中其差异均无统计学意义（P值分别为0.949、0.238）。

结论

可根据PIT评分及LMR的状态初步评估患者的疾病风险。低LMR提示患者具有更差的预后。

[A retrospective analysis of clinical characteristics and prognostic factors for 124 cases of primary gastric lymphomas]

目的

探讨原发胃淋巴瘤（PGL）的临床特征、治疗方法及预后。

方法

以2009年7月至2016年1月收治的124例PGL患者为研究对象，回顾性分析患者的临床资料，并探讨患者初诊时临床特征与预后的关系。

结果

124例PGL患者中包括弥漫大B细胞淋巴瘤（DLBCL）93例、黏膜相关淋巴组织（MALT）淋巴瘤25例、外周T细胞淋巴瘤非特指型4例、套细胞淋巴瘤和结外NK/T细胞淋巴瘤各1例。93例原发胃DLBCL（PG-DLBCL）患者中，非生发中心型（non-GCB）48例，生发中心型（GCB）45例，其中10例（10.8%）为MALT淋巴瘤转化的DLBCL。胃幽门螺杆菌检测：DLBCL患者阳性率51.2%（21/41），MALT淋巴瘤患者阳性率43.5%（10/23）。单因素分析结果显示临床分期Ⅲ~Ⅳ期（P=0.002）、B症状（P=0.001）、高国际预后指数（P<0.001）、HGB<100 g/L（P<0.001）、白蛋白<35 g/L（P=0.001）、LDH升高（P<0.001）、β₂微球蛋白升高（P=0.003）、未联合利妥昔单抗（P=0.006）是影响PG-DLBCL患者无进展生存（PFS）的不良因素。多因素分析结果显示临床分期Ⅲ~Ⅳ期（HR=5.113，95%CI 1.087~24.048，P=0.039）、LDH升高（HR=5.111，95%CI 1.651~15.827，P=0.005）是影响患者PFS的独立危险因素。在PG-DLBCL non-GCB型组，是否接受利妥昔单抗治疗对患者PFS率的影响差异有统计学意义（P=0.013）。MALT淋巴瘤转化与非转化的DLBCL患者PFS率差异无统计学意义（P=0.373）。

结论

PGL以DLBCL和MALT淋巴瘤多见，PG-DLBCL是一组高度异质性的恶性肿瘤，临床分期Ⅲ~Ⅳ期和LDH升高是影响PG-DLBCL患者PFS的独立危险因素。

[Primary ciliary dyskinesia with HYDIN gene mutations in a child and literature review]

Objective: To review children's primary ciliary dyskinesia (PCD) in the pathogenesis, clinical manifestation, diagnosis and treatment. Method: To summarize and analyze the clinical data of a patient who was admitted to the first affiliated hospital of Xiamen University with primary ciliary dyskinesia in April 2014 while referring to related literature. Result: An 11 years old boy, weighting about 22 kg, had a course of more than 10 years with repeated cough, stuffy and runny nose shortly after the birth. Examinations after admission to hospital showed that he presented with visible clubbing, bilateral paranasal sinus area tenderness, pharynx posterior wall with visible yellow pussy stuff drip and bilateral lung had scattered wet rales. Auxiliary examination revealed bilateral maxillary sinus, ethmoid sinus inflammation and bronchitis with left lower lung bronchiectasis. Fiberoptic bronchoscopy discovered congestion and a lot of sputum; ciliary biopsy pathology displayed that cilia were sparse and partial cilia 9+ 2 microtubules structural abnormalities. Full sequence of exon gene sequencing revealed two mutations located at chromosome 16 chr16: 71061369 (non-coding regions) and chr16: 70993591 (coding). Two novel mutations m. 3362A>G(E20) and c. 6101G>A(E39) in exon 16 of the HYDIN gene were identified. With the" ciliary motility disorder, gene" as keywords , the CNKI, Wanfang digital knowledge service platform and PubMed were searched for relevant articles from the establishment to July 2016. The studies retrieved included 9 cases and these cases were summarized. Comprehensive analysis showed that HYDIN gene mutations related PCD patients had the typical PCD performance such as repeatedly wet cough, sinusitis, bronchiectasis, and otitis media. The majority of patients have a history of acute respiratory distress syndrome in infancy and no visceral dislocation was not found. Most of the patients had no obvious structural abnormalities in cilia electron microscopic examination. Conclusion: The PCD patients with HYDIN genes mutations have clinical manifestations such as sinusitis, otitis media, bronchiectasis but without transposition of viscera. Cilia structure can be normal under the electron microscopic examination in some of patients.

[Blood cerebrospinal fluid barrier damage of rats induced by lead acetate or nano-lead exposure]

OBJECTIVE

To investigate the damage of blood-cerebrospinal fluid barrier (BCB) of rats induced by lead and nano-lead exposure in order to provide the basis for mechanism study of lead neurotoxicity.

METHODS

39 male rats were randomly divided into control group, lead acetate exposed group and nano-lead exposed group. Rats in lead acetate exposed group and nano-lead exposed group were given 20 mg/kg lead acetate or nano-lead by oral gavage and rats in control groups were given the same amount saline for 9 weeks.Morris maze was used to test the learning function, serum albumin and CSF albumin were determined by ELISA. Confocal laser scanning microscope was applied to detect ZO-1 and Occludin protein expression in choroid plexus, real time-PCR was used to test the expression of ZO-1 and Occludin mRNA expression. Pathological changes of choroid plexus cells were observed by the electron microscopy.

RESULTS

Compared with the control group, the escape latency of rats in lead acetate or nano-lead exposure group were longer and times of across platform were less. The levels of CSF albumin and the CSF albumin index in lead acetate or nano-lead exposed rats were obviously higher, and the fluorescence intensity of ZO-1, Occludin as well as mRNA expressions were lower than those in control group(P<0.05). Compared with lead acetate exposed group, the levels of CSF albumin and the CSF albumin index in nano-lead exposure group were higher. The fluorescence intensity and mRNA expressions of ZO-1, Occludin in nano-lead exposure group were than those in lead acetate group(P<0.05). Electron microscopy revealed that lead acetate or nano-lead exposure could induce shorter microvillus of choroid plexus epithelial cells, mitochondrion destruction and partial disconnection in intracellular junctions between two adjacent epithelial cells.

CONCLUSION

Lead acetate and nano-lead exposed can result in the blood-cerebrospinal fluid barrier damage, which may involve in the process of lead induced neurotoxicity. Meanwhile, nano-lead exposure can induced in more worse damage in terms of blood-results in blood-cerebrospinal fluid barrier function.

Pyrroloquinoline quinone enhances the resistance to oxidative stress and extends lifespan upon DAF-16 and SKN-1 activities in C. elegans

Pyrroloquinoline quinone (PQQ) is linked to fundamental biological processes such as mitochondrial biogenesis and lipid metabolism. PQQ may also function as an essential micronutrient during animal development. Recent studies have shown the therapeutic potential of PQQ for several age-related diseases due to its antioxidant capacity. However, whether PQQ can promote longevity is unknown. Here, we investigate the effects of PQQ on oxidative stress resistance as well as lifespan modulation in Caenorhabditis elegans. We find that PQQ enhances resistance to oxidative stress and extends the lifespan of C. elegans at optimal doses. The underlying molecular mechanism involves the increased activities of the primary lifespan extension transcriptional factors DAF-16/FOXO, the conserved oxidative stress-responsive transcription factor SKN-1/Nrf2, and upregulation of daf-16, skn-1 downstream targets including sod-3, hsp16.2, gst-1 and gst-10. Our findings uncover a novel role of PQQ in longevity, supporting PQQ as a possible dietary supplement for overall health improvement.

Apoptosis and necrosis induced by novel realgar quantum dots in human endometrial cancer cells via endoplasmic reticulum stress signaling pathway

Realgar (AS4S4) has been used in traditional medicines for malignancy, but the poor water solubility is still a major hindrance to its clinical use. Realgar quantum dots (RQDs) were therefore synthesized with improved water solubility and bioavailability. Human endometrial cancer JEC cells were exposed to various concentrations of RQDs to evaluate their anticancer effects and to explore mechanisms by the MTT assay, transmission electron microscopy (TEM), flow cytometry, real-time reverse transcriptase polymerase chain reaction (RT-PCR) and Western blot analysis. Results revealed that the highest photoluminescence quantum yield of the prepared RQDs was up to approximately 70%, with the average size of 5.48 nm. RQDs induced antipro-liferative activity against JEC cells in a concentration-dependent manner. In light microscopy and TEM examinations, RQDs induced vacuolization and endoplasmic reticulum (ER) dilation in JEC cells in a concentration-dependent manner. ER stress by RQDs were further confirmed by increased expression of GADD153 and GRP78 at both mRNA and protein levels. ER stress further led to JEC cell apoptosis and necrosis, as evidenced by flow cytometry and mitochondrial membrane potential detection. Our findings demonstrated that the newly synthesized RQDs were effective against human endometrial cancer cells. The underlying mechanism appears to be, at least partly, due to ER stress leading to apoptotic cell death and necrosis.

TGF-β1 polymorphisms and familial aggregation of liver cancer in Guangxi, China

The goal of present study was to investigate the relationship between polymorphisms of TGF-β1 and familial aggregation of liver cancer in Guangxi Zhuang, Han, and Yao populations. We conducted a population-based case-control family study of liver cancer in Guanxi, China. A total of 214 individuals from 37 case families were surveyed for polymorphisms in TGF-β1. We genotyped six functional TGF-β1 polymorphisms: rs1800469, rs2241715, rs2241716, rs11466345, rs8105161, and rs747857. Levels of TGF-β1, hepatitis B surface antigen, and anti-hepatitis C virus in all serum samples were detected using the enzyme-linked immunoassay method, and presence of hepatitis B virus (HBV) DNA was determined using polymerase chain reaction amplification. A standardized questionnaire was used to collect information from subjects, including alcohol consumption, smoking, eating, and water drinking habits. The results were compared with those from 214 control individuals. The results showed that the TGF-β1 genotypes rs1800469, rs2241715, rs2241715, and rs8105161 were more frequent in patients than in controls. The risk factors for familial aggregation of liver cancer in Guangxi were determined, from high to low, to be: drinking sugared beverages > alcohol consumption > HBV DNA-positive > rs1800469 TT homozygous genotype > rs2241715 TT homozygous genotype. The results suggested that TGF-β1 rs1800469 TT and rs2241715 TT homozygote genotypes represent the genetic factors underlying familial clustering of liver cancer in Guangxi, and that drinking water use, alcohol consumption, and testing positive for HBV DNA are the main environmental factors contributing to familial aggregation of liver cancer in Guangxi.

Realgar quantum dots induce apoptosis and necrosis in HepG2 cells through endoplasmic reticulum stress

Realgar (As₄S₄) has been used in traditional Chinese medicines for treatment of malignancies. However, the poor water solubility of realgar limits its clinical application. To overcome this problem, realgar quantum dots (RQDs; 5.48±1.09 nm) were prepared by a photoluminescence method. The mean particle size was characterized by high-resolution transmission electron microscopy and scanning electron microscopy. Our recent studies revealed that the RQDs were effective against tumor growth in tumor-bearing mice without producing apparent toxicity. The present study investigated their anticancer effects and mechanisms in human hepatocellular carcinoma (HepG2) cells. The HepG2 cells and human normal liver (L02) cells were used to determine the cytotoxicity of RQDs. The portion of apoptotic and dead cells were measured by flow cytometry with Annexin V-fluorescein isothiocyanate/propidium iodide double staining. Apoptosis-related proteins and genes were examined by western blot analysis and reverse transcription-quantitative polymerase chain reaction, and the mitochondrial membrane potential was assayed by confocal microscope with JC-1 as a probe. RQDs exhibited cytotoxicity in a concentration-dependent manner and HepG2 cells were more sensitive compared with normal L02 cells. At 15 µg/ml, 20% of the cells were apoptotic, while 60% of the cells were necrotic at 30 µg/ml. The anti-apoptosis protein Bcl-2 was dose-dependently decreased, while pro-apoptotic protein Bax was increased. There was a loss of mitochondrial membrane potential and expression of the stress genes C/EBP-homologous protein 10 and glucose-regulated protein 78 was increased by RQDs. RQDs were effective in the inhibition of HepG2 cell proliferation and this effect was due to induction of apoptosis and necrosis through endoplasmic reticulum stress.

Enhanced fast charge–discharge performance of Li4Ti5O12 as anode materials for lithium-ion batteries by Ce and CeO2 modification using a facile method

Ce and CeO₂in situ modified Li₄Ti₅O₁₂ with fast charge–discharge performance for lithium-ion batteries were prepared by a solid-state method. The improved performance are found to be due to the increased ionic and electronic conductivity.

Analysis of signaling pathways in recurrent breast cancer

Breast cancer remains the second largest cause of death in women from cancer. By analyzing gene expression profiles in samples from breast cancer patients, 844 differentially expressed genes (DEGs) were identified in breast cancer metastasis. The 10 most significant signaling pathways identified through enrichment analysis contained DEGs were involved in oxidative phosphorylation, DNA replication, extracellular matrix-receptor interactions and others. Furthermore, survival analysis demonstrated that 5 of these signaling pathways were closely related to the survival time of breast cancer patients including basal transcription factors, cell cycle, ECM-receptor interaction, spliceosome, and DNA replication. Our findings increase the understanding of the network of signaling pathways involved in breast cancer metastasis and may provide theoretical support for further therapeutic study.

In vitro antioxidant activities of endophytic fungi isolated from the liverwort Scapania verrucosa

We investigated in vitro antioxidant activities of 49 endophytic fungi isolated from the liverwort Scapania verrucosa. Based on morphological and molecular identification, the endophytic fungi isolated were classified into seven genera (Hypocrea, Penicillium, Tolypocladium, Chaetomium, Xylaria, Nemania, and Creosphaeria), all belonging to one family (Xylariaceae). By screening with the 2,2'-azino-di(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) decolorization assay, the ethyl acetate extracts of five endophytic fungi (T7, T21, T24, T32, and T38 strains), which exhibited remarkable Trolox equivalent (TE) antioxidant capacity (ranging from 997.06 to 1248.10 μmol TE/g extract), were selected and their antioxidant capacity was further evaluated by assays for 2,2'-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, hydroxyl radical scavenging, reducing power, and ferrous ion chelating. The ethyl acetate extracts of two endophytic fungi (T24 and T38) were found to have comparable scavenging abilities on both DPPH-free radicals (93.9 and 88.7%, respectively, at 50 μg/mL) and hydroxyl radicals (97.1 and 89.4%, respectively, at 2 mg/mL) when compared with those of the positive controls (ascorbic acid and butylated hydroxytoluene, respectively). Although their reducing powers were similar to that of butylated hydroxytoluene, as indicated by absorbance (0.35 and 0.30 at 50 μg/mL, respectively), only the T38 strain's ethyl acetate extract showed ferrous ion chelating ability (92.9% at 1 mg/mL) comparable to that of the EDTA-2Na control. These endophytic fungi in S. verrucosa are a potential novel source of natural antioxidants.

Key pathways involved in prostate cancer based on gene set enrichment analysis and meta analysis

Prostate cancer is one of the most common male malignant neoplasms; however, its causes are not completely understood. A few recent studies have used gene expression profiling of prostate cancer to identify differentially expressed genes and possible relevant pathways. However, few studies have examined the genetic mechanics of prostate cancer at the pathway level to search for such pathways. We used gene set enrichment analysis and a meta-analysis of six independent studies after standardized microarray preprocessing, which increased concordance between these gene datasets. Based on gene set enrichment analysis, there were 12 down- and 25 up-regulated mixing pathways in more than two tissue datasets, while there were two down- and two up-regulated mixing pathways in three cell datasets. Based on the meta-analysis, there were 46 and nine common pathways in the tissue and cell datasets, respectively. Three up- and 10 down-regulated crossing pathways were detected with combined gene set enrichment analysis and meta-analysis. We found that genes with small changes are difficult to detect by classic univariate statistics; they can more easily be identified by pathway analysis. After standardized microarray preprocessing, we applied gene set enrichment analysis and a meta-analysis to increase the concordance in identifying biological mechanisms involved in prostate cancer. The gene pathways that we identified could provide insight concerning the development of prostate cancer.

Effect of fragile histidine triad gene on biologic properties of muco-epidermoid carcinoma cells

BACKGROUND

The fragile histidine triad (FHIT) gene is abnormally expressed in many kinds of tumors and plays an important role in tumor development. However, the function of the FHIT gene in muco-epidermoid carcinoma (MEC) is still unknown. This study aimed to investigate the effect of exogenous FHIT gene on the biologic properties of MEC cells.

METHODS

Wild-type FHIT gene was transferred into MEC-1 cells. The in vitro proliferation, clone formation ability and apoptosis of FHIT-transfected MEC-1 cells (MEC-FHITc4) were examined by cell counting, clonal forming assay, immunochemical staining, histochemical staining, flow cytometry analysis and transmission electron microscopy. The tumorigenicity of MEC-FHITc4 cells was observed by in vivo study in nude mice.

RESULTS

In vitro study showed that the population doubling times of MEC-1 and MEC-FHITc4 cells were 21.03 h and 26.86 h, respectively. FHIT gene transfer reduced the percentage of cells in cell cycle S phase (3.8%) and kept more cells in the G(1) phase (62.4%). Additionally, the clonal forming rates of MEC-1 and MEC-FHITc4 were 17.9+/-0.87% and 12.3+/-0.02%, respectively. In a 4-week tumor growth study in nude mice, FHIT transfection suppressed the tumor growth by 70.1+/-0.38%. Interestingly, MEC-FHITc4 cells were stained more strongly with Alician Blue and Periodic Schiffs than control cells.

DISCUSSION

The FHIT gene might function to inhibit the proliferation and tumorigenicity of MEC-1 cells, and to induce the differentiation of MEC-1 cells, in vitro and in vivo.

A method to quantify hand-transmitted vibration exposure based on the biodynamic stress concept

This study generally hypothesized that the vibration-induced biodynamic stress and number of its cycles in a substructure of the hand-arm system play an important role in the development of vibration-induced disorders in the substructure. As the first step to test this hypothesis, the specific aims of this study were to develop a practical method to quantify the biodynamic stress-cycle measure, to compare it with ISO-weighted and unweighted accelerations, and to assess its potential for applications. A mechanical-equivalent model of the system was established using reported experimental data. The model was used to estimate the average stresses in the fingers and palm. The frequency weightings of the stresses in these substructures were derived using the proposed stress-cycle measure. This study found the frequency dependence of the average stress distributed in the fingers is different from that in the palm. Therefore, this study predicted that the frequency dependencies of finger disorders could also be different from those of the disorders in the palm, wrist, and arms. If vibration-induced white finger (VWF) is correlated better with unweighted acceleration than with ISO-weighted acceleration, the biodynamic stress distributed in the fingers is likely to play a more important role in the development of VWF than is th e biodynamic stressdistributed in the other substructures of the hand-arm system. The results of this study also suggest that the ISO weighting underestimates the high-frequency effect on the finger disorder development but it may provide a reasonable risk assessment of the disorders in the wrist and arm.

Evaluation of the in vitro activity and in vivo bioavailability of realgar nanoparticles prepared by cryo-grinding

Arsenic trioxide (As2O3) has been a research focus because of its promising anticancer effects especially in the treatment of leukemia. Another arsenic compound, realgar (As2S2), has long been used as a therapeutic agent to treat some diseases in ancient China and Europe, and its medicinal effects have attracted increasing attentions in recent years. However, its poor water-solubility unfortunately results in poor bioavailability and hampers it from being studied and used for possible clinical application. In this study, nanosized realgar particles were prepared by cryo-grinding with polyvinylpyrrolidone (PVP) and/or sodium dodecyl sulfate (SDS). Major physical properties of the respective nanosized realgar particles were characterized. Co-grinding realgar with PVP and/or SDS produced smaller and more monodisperse suspension of nanoparticles. The in vitro cytotoxic effects of such nanosized realgar particles on selected human ovarian (CI80-13S, OVCAR, OVCAR-3) and cervical (HeLa) cancer cell lines were investigated. Significant anti-proliferation effect of these realgar nanoparticles on these cancer cell lines was observed. CI80-13S was most sensitive to the nanosized realgar particles with IC50 values of less than 1 microM as As2S2, whereas the other cancer cell lines had IC50 values in a range of 2-4 microM as As2S2. The cytotoxic activity of the realgar nanoparticles to these human gynecological cell lines was comparable to arsenic trioxide observed previously. In these cancer cell lines, the cytotoxic effects were caused by apoptosis as confirmed by cell cycle and DNA laddering analysis. In in vivo study, a remarkable increase in urinary recovery of arsenic was observed in rats after a single oral administration of the cryo-ground realgar particle suspension. Ranging from 58.5 to 69.6% of the administered dose of arsenic was recovered in urine in the first 48 h from the PVP and/or SDS co-ground preparations; whereas the original realgar powder gave a urinary recovery of only 24.9%. The finding suggested that size reduction of realgar particles to nano levels could enhance its bioavailability substantially.

Efficacy assessment of phenobarbital in epilepsy: a large community-based intervention trial in rural China

BACKGROUND

Many people with epilepsy need not experience further seizures if the diagnosis and treatment are correct. Most epilepsy patients have convulsions, which are usually fairly easy to diagnose. This study tested a model for treatment of people with convulsive forms of epilepsy at primary health-care level in rural areas of China.

METHODS

Patients with convulsive epilepsy were identified at primary care level and provided with phenobarbital monotherapy. Local physicians, who were provided with special training, carried out screening, treatment, and follow-up. A local neurologist confirmed the diagnoses. Efficacy was assessed from the percentage reduction in seizure frequency from baseline and the retention of patients on treatment.

FINDINGS

The study enrolled 2455 patients. In 68% of patients who completed 12 months' treatment, seizure frequency was decreased by at least 50%, and a third of patients were seizure free. 72% of patients who completed 24 months' treatment had reduction of seizure frequency of at least 50% and a quarter of patients remained seizure free. Probability of retention was 0.84 at 1 year, and 0.76 at 2 years. Medication was well tolerated and reported adverse events were mild; only 32 patients (1%) discontinued medication because of side-effects.

INTERPRETATION

This pragmatic study confirmed that this simple protocol was suitable for the treatment of convulsive forms of epilepsy in rural areas of China. Physicians with basic training could treat epilepsy patients with phenobarbital, with beneficial effects for most patients with convulsive seizures. Few cognitive or behavioural adverse events were noted, but formal psychometric testing was not done.

Elimination of the friction effects in unconfined compression tests of biomaterials and soft tissues

The mechanical properties of biomaterials and soft tissues are determined conventionally using unconfined compression tests. In such tests, frictionless specimen/platen contact in unconfined compression tests has to be assumed in determining the material properties of the materials. Previous theoretical analysis demonstrated, however, that the effects of the friction at the specimen/platen contact interface on the measured stress responses are non-negligible. In this study, a computational approach was proposed to eliminate the effects of friction. The friction coefficient between the specimen and the compression platens is measured first. Using a finite element model, the stress strain relationship, without the influence of the friction effects, can be derived from the experimental data obtained in conventional unconfined compression tests. In order to validate the proposed approach, unconfined compressive tests of rubber have been performed.

Analysis of the contact interactions between fingertips and objects with different surface curvatures

Previous experimental observations indicated that the contact interactions between finger and tool handle interfere with the grasp stability, affecting the comfort and manipulations of handheld tools. From a biomechanical point of view, the curvature of the contact surface should affect the contact pressure and contact area, and thereby the comfort and manipulations of hand tools. The current authors analysed, via a finite element model, the contact interactions between fingertips and objects with different curvatures. The effects of the curvature on the contact stiffness, fingertip deformations, contact pressure distributions, and stress/strain distributions within the soft tissues were analysed. The simulation results indicated that the curvature of the contact interface influences the contact characteristics significantly. For a given contact force, the contact area and the contact stiffness increase but the contact pressure and the fingertip deformation decrease with the decrease of the contact surface curvature. The present simulation results will be useful for ergonomic designers in their aim to improve the design of tool handles.

Distribution of mechanical impedance at the fingers and the palm of the human hand

A comprehensive understanding of the complex biodynamic response of the human fingers-hand-arm system may help researchers determine the causation of injuries arising from hand-transmitted vibration. This study theoretically demonstrates that the mechanical impedance (MI) in a hand power grip, as a measure of the biodynamic response of the system, can be divided into finger MI and palm MI. A methodology is developed to measure them separately and to investigate their distribution characteristics. This study involves 6 adult male subjects, constant-velocity sinusoidal excitations at 10 different discrete frequencies (16, 25, 40, 63, 100, 160, 250, 400, 630, 1000 Hz), and three different hand-handle coupling conditions. Our results suggest that at low frequencies (40 Hz), the palm MI is substantially higher than the finger MI; the majority of the hand MI remains distributed at the palm up to 100 Hz; and at frequencies higher than 160 Hz, the finger MI is comparable to or higher than the palm MI. Furthermore, at frequencies equal to or above 100 Hz, the finger MI is practically independent of the palm-handle coupling conditions. Knowledge of the MI distribution pattern may increase the understanding of vibration transmission to the hand and aid in the development of effective isolation devices.

Biodynamic Response of Human Fingers in a Power Grip Subjected to a Random Vibration

Background. Knowledge of the biodynamic response (BR) of the human hand-arm system is an important part of the foundation for the measurement and assessment of hand-transmitted vibration exposure. This study investigated the BR of human fingers in a power grip subjected to a random vibration. Method. Ten male subjects were used in the experiment. Each subject applied three coupling actions to a simulated tool handle at three different finger grip force levels. Results and Conclusions. The BR is practically independent of the hand coupling actions for frequencies at or above 100 Hz. Above 50 Hz, the BR is correlated to finger and hand sizes. Increasing the finger coupling force significantly increases the BR. Therefore, hand forces should be measured and used when assessing hand-transmitted vibration exposure. The results also show that under a constant-velocity vibration, the finger vibration power absorption at frequencies above 200 Hz is approximately twice that at frequencies below 100 Hz. This suggests that the frequency weighting specified in the current ISO 5349-1 (2001) may underestimate the high frequency effect on vibration-induced finger disorders.

A structural fingertip model for simulating of the biomechanics of tactile sensation

Tactile performance of human fingertips is associated with activity of the nerve endings and sensitivity of the soft tissue within the fingertip to the static and dynamic skin indentation. The nerve endings in the fingertips sense the stress/strain states developed within the soft tissue, which are affected by the material properties of the tissues. The vibrotactile sensation and tactile performance are thus believed to be strongly influenced by the nonlinear and time-dependent properties of the soft tissues. The purpose of the present research is to simulate the biomechanics of tactile sensation. A two-dimensional model, which incorporates the essential anatomical structures of a finger (i.e. skin, subcutaneous tissue, bone, and nail), has been used for the analysis. The skin tissue is assumed to be hyperelastic and viscoelastic. The subcutaneous tissue is considered to be a nonlinear, biphasic material composed of a hyperelastic solid and an inviscid fluid phase. The nail and bone are considered to be linearly elastic. The advantages of the proposed fingertip model over the previous "waterbed" and "continuum" fingertip models include its ability to predict the deflection profile of the fingertip surface, the stress and strain distributions within the soft tissue, and most importantly, the dynamic response of the fingertip to mechanical stimuli. The proposed model is applied to simulate the mechanical responses of a fingertip under a line load, and in one-point (1PT) and two-point (2PT) tactile discrimination tests. The model's predictions of the deflection profiles of a fingertip surface under a line load agree well with the reported experimental data. Assuming that the mechanoreceptors in the dermis sense the stimuli associated with normal strains (the vertical and horizontal strains) and strain energy density, our numerical results suggest that the threshold of 2PT discrimination may lie between 2.0 and 3.0 mm, which is consistent with the published experimental data. The present study represents an effort to develop a structural model of the fingertip that incorporates its anatomical structure, and the nonlinear and time-dependent properties of the soft tissues.

Vibration energy absorption (VEA) in human fingers-hand-arm system

A methodology for measuring the vibration energy absorbed into the fingers and the palm exposed to vibration is proposed to study the distribution of the vibration energy absorption (VEA) in the fingers-hand-arm system and to explore its potential association with vibration-induced white finger (VWF). The study involved 12 adult male subjects, constant-velocity sinusoidal excitations at 10 different discrete frequencies in the range of 16-1000 Hz, and four different hand-handle coupling conditions (finger pull-only, hand grip-only, palm push-only, and combined grip and push). The results of the study suggest that the VEA into the fingers is considerably less than that into the palm at low frequencies (< or = 25 Hz). They are, however, comparable under the excitations in the 250-1000 Hz frequency range. The finger VEA at high frequencies (> or = 100 Hz) is practically independent of the hand-handle coupling condition. The coupling conditions affect the VEA into the fingers and the palm very differently. The finger VEA results suggest that the ISO standardized frequency weighting (ISO 5349-1, 2001) may underestimate the effect of high frequency vibration on vibration-induced finger disorders. The proposed method may provide new opportunities to examine VEA and its association with VWF and other types of vibration-induced disorders in the hand-arm system.

Speciation of inorganic and methylated arsenic compounds by capillary zone electrophoresis with indirect UV detection

A capillary zone electrophoresis (CZE) method with indirect UV detection was developed to simultaneously separate inorganic and organic arsenic compounds including arsenite (iAsIII), arsenate (iAsV), monomethylarsonate and dimethylarsenic acid (DMAV). 2,6-Pyridinedicarboxylic acid (PDC) and n-hexadecyltrimethylammonium hydroxide (CTAOH) were selected to compose a background electrolyte (BGE), where PDC was used as chromophore and CTAOH functioned as electroosmotic flow (EOF) modifier to reduce/eliminate EOF. The choice of detection wavelength, the optimization of BGE pH, and effects of applied electric field strength and temperature on separation were further investigated. The limits of detection for the targeted analytes were between 0.19 and 0.23 ppm as molecule. Good linearity of more than three orders of magnitude was obtained. Repeatability of migration times and peaks areas were 0.8-1.7 and 3.4-6.9% R.S.D.; whereas reproducibility were 1.2-2.2 and 3.6-7.1% R.S.D., respectively. The established CZE method was then applied to analyze the alkali extracts of realgar (As2S2) and orpiment (As2S3). The main components in both alkali extracts were identified to be iAsIII and iAsV.

Dynamic force responses of skeletal muscle during stretch-shortening cycles

Muscle damage due to stretch-shortening cycles (i.e., cyclic eccentric/concentric muscle actions) is one of the major concerns in sports and occupational related activities. Mechanical responses of whole muscle have been associated with damage in neural motor units, in connective tissues, and the force generation mechanism. The objective of this study was to introduce a new method to quantify the real-time changes in skeletal muscle forces of rats during injurious stretch-shortening cycles. Male Sprague Dawley rats ( n=24) were selected for use in this study. The dorsi flexor muscle group was exposed to either 150 stretch-shortening cycles ( n=12) or 15 isometric contractions ( n=12) in vivo using a dynamometer and electrical stimulation. Muscle damage after exposure to stretch-shortening cycles was verified by the non-recoverable force deficit at 48 h and the presence of myofiber necrosis. Variations of the dynamic forces during stretch-shortening cycles were analyzed by decomposing the dynamic force signature into peak force ( F(peak)), minimum force ( F(min)), average force ( F(mean)), and cyclic force ( F(a)). After the 15th set of stretch-shortening cycles, the decrease in the stretch-shortening parameters, F(peak), F(min), F(mean), and F(a), was 50% ( P<0.0001), 26% ( P=0.0055), 68% ( P<0.0001), and 50% ( P<0.0001), respectively. Our results showed that both isometric contractions and stretch-shortening cycles induce a reduction in the isometric force. However, the force reduction induced by isometric contractions fully recovered after a break of 48 h while that induced by stretch-shortening cycles did not. Histopathologic assessment of the tibialis anterior exposed to stretch-shortening cycles showed significant myofiber degeneration and necrosis with associated inflammation, while muscles exposed to isometric contractions showed no myofiber degeneration and necrosis, and limited inflammation. Our results suggest that muscle damage can be identified by the non-recoverable isometric force decrement and also by the variations in the dynamic force signature during stretch-shortening cycles.

Analysis of skin deformation profiles during sinusoidal vibration of fingerpad

Vibrotactile perception threshold measurement has been widely used to diagnose the severity of peripheral neuropathy associated with hand-arm vibration syndrome and sensory losses in stroke and diabetic patients. The vibration perception threshold is believed to be influenced by many factors, such as contact force and vibration frequency. The present study is intended to analyze, theoretically, the time-dependent deformation profile of skin surface, strain distributions within soft tissue, and response force of a fingertip when it is stimulated by a probe vibrating with a sinusoidal movement. A two-dimensional finite element model, which incorporates the essential anatomical structures of a finger: skin, subcutaneous tissue, bone, and nail, has been proposed to analyze the effects of vibration amplitude, frequency, and preindentation on the dynamic interaction between the fingerpad and vibrating probe. The simulation results suggest that the fraction of time over which the skin separates from the probe during vibration increases with increasing vibration frequency and amplitude, and decreases with increased preindentation of the probe. The preindentation of the probe has been found to significantly reduce the trend of skin/probe decoupling. The simulation results show reasonably consistent trends with the reported experimental data.

Dynamic interaction between a fingerpad and a flat surface: experiments and analysis

Many neural and vascular diseases in hands and fingers have been related to the degenerative responses of local neural and vascular systems in fingers to excessive dynamic loading. Since fingerpads serve as a coupling element between the hand and the objects, the investigation of the dynamic coupling between fingertip and subjects could provide important information for the understanding of the pathomechanics of these neural and vascular diseases. In the present study, the nonlinear and time-dependent force responses of fingertips during dynamic contact have been investigated experimentally and theoretically. Four subjects (2 male and 2 female) with an average age of 24 years participated in the study. The index fingers of right and left hands of each subject were compressed using a flat platen via a micro testing machine. A physical model was proposed to simulate the nonlinear and time-dependent force responses of fingertips during dynamic contact. Using a force relaxation test and a fast loading test at constant loading speed, the material/structural parameters underlying the proposed physical model could be identified. The predicted rate-dependent force/displacement curves and time-histories of force responses of fingertips were compared with those measured in the corresponding experiments. Our results suggest that the force responses of fingertips during the dynamic contacts are nonlinear and time-dependent. The physical model was verified to characterize the nonlinear, rate-dependent force-displacement behaviors, force relaxations, and time-histories of force responses of fingertips during dynamic contact.

The prevalence and treatment gap in epilepsy in China: an ILAE/IBE/WHO study

The authors carried out a door-to-door survey to determine the prevalence of epilepsy among 55,000 people in China. The lifetime prevalence was 7.0/1000, and 41% of all persons had never received appropriate treatment. The prevalence of active epilepsy was 4.6/1000, and 63% of people with active epilepsy had not received antiepileptic treatment in the week before the survey. Figures for the prevalence and the treatment gap were significantly higher than previous estimates.

How to determine the permeability for cement infiltration of osteoporotic cancellous bone

Cement augmentation is an emerging surgical procedure in which bone cement is used to infiltrate and reinforce osteoporotic vertebrae. Although this infiltration procedure has been widely applied, it is performed empirically and little is known about the flow characteristics of cement during the injection process. We present a theoretical and experimental approach to investigate the intertrabecular bone permeability during the infiltration procedure. The cement permeability was considered to be dependent on time, bone porosity, and cement viscosity in our analysis. In order to determine the time-dependent permeability, ten cancellous bone cores were harvested from osteoporotic vertebrae, infiltrated with acrylic cement at a constant flow rate, and the pressure drop across the cores during the infiltration was measured. The viscosity dependence of the permeability was determined based on published experimental data. The theoretical model for the permeability as a function of bone porosity and time was then fit to the testing data. Our findings suggest that the intertrabecular bone permeability depends strongly on time. For instance, the initial permeability (60.89 mm(4)/N(*)s) reduced to approximately 63% of its original value within 18 seconds. This study is the first to analyze cement flow through osteoporotic bone. The theoretical and experimental models provided in this paper are generic. Thus, they can be used to systematically study and optimize the infiltration process for clinical practice.

Modeling of time-dependent force response of fingertip to dynamic loading

An extended exposure to repeated loading on fingertip has been associated to many vascular, sensorineural, and musculoskeletal disorders in the fingers, such as carpal tunnel syndrome, hand-arm vibration syndrome, and flexor tenosynovitis. A better understanding of the pathomechanics of these sensorineural and vascular diseases in fingers requires a formulation of a biomechanical model of the fingertips and analyses to predict the mechanical responses of the soft tissues to dynamic loading. In the present study, a model based on finite element techniques has been developed to simulate the mechanical responses of the fingertips to dynamic loading. The proposed model is two-dimensional and incorporates the essential anatomical structures of a finger: skin, subcutaneous tissue, bone, and nail. The skin tissue is assumed to be hyperelastic and viscoelastic. The subcutaneous tissue was considered to be a nonlinear, biphasic material composed of a hyperelastic solid and an invicid fluid, while its hydraulic permeability was considered to be deformation dependent. Two series of numerical tests were performed using the proposed finger tip model to: (a) simulate the responses of the fingertip to repeated loading, where the contact plate was assumed to be fixed, and the bone within the fingertip was subjected to a prescribed sinusoidal displacement in vertical direction; (b) simulate the force response of the fingertip in a single keystroke, where the keyboard was composed of a hard plastic keycap, a rigid support block, and a nonlinear spring. The time-dependent behavior of the fingertip under dynamic loading was derived. The model predictions of the time-histories of force response of the fingertip and the phenomenon of fingertip separation from the contacting plate during cyclic loading agree well with the reported experimental observations.

Elastic anisotropy of articular cartilage is associated with the microstructures of collagen fibers and chondrocytes

Chondrocyte shape and volumetric concentration change as a function of depth in articular cartilage. A given chondrocyte shape produces different effects on the global material properties depending on the structure of the collagen fiber network. The shape and volumetric concentration of chondrocytes in articular cartilage appear to be related to the mechanical stability of the matrix. The present study was aimed to investigate, theoretically, the effects of the structural arrangement of the collagen fiber network, and the shape and distribution of chondrocytes, on the global material behavior of articular cartilage. Articular cartilage was assumed to be a four-phasic composite comprised of a matrix (associated with the properties of the proteoglycan structure), vertically and horizontally distributed collagen fibers, and spheroidal inclusions representing chondrocytes. A solution for composite materials was used to estimate the global, effective material properties of cartilage. Only the elasticity of the solid phase was investigated in the present study. Our simulations suggest that a soft, spheroidal cell inclusion in a fiber-reinforced proteoglycan matrix affects the material properties differently depending on the shape of the spheroidal inclusions. If the long axis of the inclusions is parallel to the collagen fibers, as in the deep zone, the soft inclusions increase the stiffness of the composite in the fiber direction, and reduce the stiffness of the composite in the direction normal to the fibers. Furthermore, we found that Young's modulus normal to the contact surface increases from the superficial to the deep zone in articular cartilage by a factor of 10-50, a finding that agrees well with experimental observations. Our analysis suggests that the combination of proteoglycan matrix, fiber orientation, and shape of chondrocytes are intimately related and are likely adapted to optimize the mechanical stability and load carrying capacity of the structure.

Simulation of mechanical responses of fingertip to dynamic loading

Extended exposure to mechanical vibration has been related to many vascular, sensorineural and musculoskeletal disorders of the hand-arm system, frequently termed 'hand-arm vibration syndrome' (HAVS). A two-dimensional, nonlinear finite element model of a fingertip is developed to study the stress and strain fields of the soft tissue under dynamic loading, that may be encountered while grasping and operating a hand-held power tool. The model incorporates the most essential anatomical elements of a fingertip, such as soft tissue, bone, and nail. The finger is assumed to be in contact with a steel plate, simulating the interaction between the fingertip and a vibrating machine tool or handle. The soft tissue is assumed to be nonlinearly visco-elastic, while the nail, bone, and steel plate are considered to be linearly elastic. In order to study the time-dependent deformation behavior of the fingertip, the numerical simulations were performed under ramp-like loading with different ramping periods and sinusoidal vibrations of the contacting plate at three different frequencies (1, 10, and 31.5 Hz). Owing to relatively large deformations of the soft tissue under specified static and dynamic loading, Lagrangian large deformation theory was applied in the present analysis. The effects of the loading rate and the frequency of the sinusoidal vibration on the time-dependent strain/stress distributions in the different depth within the soft tissue of the fingertip are investigated numerically. Our simulations suggest that the soft tissue of the fingertip experiences high local stress and strain under dynamic loading and the fingertip may separate from the vibrating contact surface due to the viscous deformation behaviour of the soft tissue. For a given deformation, the high frequency loading produces a higher stress in the tissues compared to that obtained at a low frequency loading. The present model may serve as a useful tool to study the mechanism of tissue degeneration under vibratory loading encountered during operation of hand-held power tools.

Inadequate placement of osteochondral plugs may induce abnormal stress-strain distributions in articular cartilage --finite element simulations

The transplantation of osteochondral (cartilage-bone) plugs is an alternative approach to treat local, full thickness cartilage defects in young patients. It is technically difficult to control the amount of the press fit tolerance and the position of the osteochondral (OC) plug in the recipient hole. Inadequate placement of the OC plugs may produce abnormal stress and strain distributions within the cartilage, and thus influence the regeneration of the injured cartilage site and the maintenance of opposing, healthy cartilage surfaces. In the present study, the influence of press fit tolerance and the placement of the OC plug on the joint contact mechanics was simulated using finite element methods. The joint was assumed to be axi-symmetric with a spherical femur and tibia and a cylindrical OC plug. Our simulations showed that small misplacements of the OC plug induced abnormal tension in the articular cartilage of the opposing, healthy cartilage surface. Such tension might induce unpredictable adaptations, or possibly degenerations, in the opposing cartilage layer. The contact stress profiles in the joint were predicted to change discontinuously across the plug/recipient interface, even when the plug was perfectly placed in the recipient hole, i.e., the plug's surface was aligned with the recipient surface. For a fixed coefficient of friction and a fixed fit tolerance, the maximal sliding force was predicted to vary with the size of the plug and reached a maximum at a specific plug diameter. The present simulations should be helpful for the design of instruments for osteochondral transplantation and placement of OC plugs, for understanding articular cartilage adaptation following osteochondral repair, and for providing insight into the mechanics at the transplant/recipient interface where proper integration of the plug into the joint is most problematic.

Dietary protective and risk factors for esophageal and stomach cancers in a low-epidemic area for stomach cancer in Jiangsu Province, China: comparison with those in a high-epidemic area

Comparative epidemiological studies with ecological and case-control approaches in high- and low-epidemic areas of China have provided us with much evidence with regard to risk and benefit in the environment. To clarify how dietary factors are involved in esophageal and stomach cancer development, we performed a case-control study in a low-epidemic area, and compared the findings with those obtained earlier for a high-epidemic area for stomach cancer in the same Jiangsu Province, China. We recruited 199 and 187 cases with esophageal and stomach cancers, respectively, and 333 population-based common controls. Odds ratios (ORs) for esophageal and stomach cancers were calculated with adjustment for potential confounding factors, using an unconditional logistic model. Current and former smoking elevated the OR for esophageal cancer, along with high intake of pickled vegetables and broiled meat, while decreased ORs were observed for frequently consumed raw vegetables and garlic. With regard to stomach cancer, ORs were increased with frequent consumption of salty fish, leftover gruel, and broiled meat, and lowered by snap bean consumption. The present risk factors were common to the previously obtained results in the high-epidemic area, and similarly distributed in each general population. While more protective factors were observed in the high-epidemic area, their penetrance was much greater in the low-epidemic area. The present study thus suggests that frequent vegetable and garlic consumption contributes to low mortality rates for esophageal and stomach cancers in a low-epidemic area, counteracting similar exposure levels for risk factors as in the high-epidemic area.

Internally located signal peptides direct hepatitis C virus polyprotein processing in the ER membrane

An endoplasmic reticulum (ER) signal peptide is an amino acid sequence motif that directs the translocation of nascent polypeptides to the lumen of ER membrane. Most of known ER signal peptides are either N-terminal cleavable or internally uncleavable. In the structural protein region of hepatitis C virus (HCV) polyprotein, however, four internally located cleavable signal peptides are arranged in a tandem array. The published experimental results indicated that the nascent HCV polyprotein is processed in the ER membrane by host signal peptidase(s) to the respective viral proteins. Here we propose that the four ER signal peptides lead the nascent HCV polyprotein to ER membrane, and the four internally located cleavable signal peptides are the sole determinant for the compartment localization of the matured viral proteins. After cleavage at the C-terminus, the signal peptides retain at the C-terminus of mature proteins, and serve as ER membrane anchors. The signal peptide directed polyprotein processing in the ER membrane preludes the virion assembly and budding from the ER membrane. This unique processing may be a general mechanism adopted by many types of virus for virion assembly and replication. The revelation of signal peptidase involved in HCV polyprotein processing presents a novel drug target to suppress HCV viral replication for the much needed HCV therapy.