[Determination of triclocarban and triclosan in urine by QuEChERS extraction and ultra-performance liquid chromatography-tandem mass spectrometry].

Objective: To establish a method for the determination of triclocarban (TCC) and triclosan (TCS) in urine by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) after purification by QuEChERS. Methods: In May 2022, urine samples were extracted by acetonitrile, purified by QuEChERS, separated by Waters Acquity UPLC BEH C18 column (100 mm×2.1 mm, 1.7 µm), and eluated with water-acetonitrile as mobile phase gradient at a flow rate of 0.3 ml/min. The detection was conducted in negative ion mode (ESI(-)) and multiple reaction monitoring (MRM) scanning, it was quantified with a internal standard method, and the methodology was verified. Results: The linear ranges of TCC and TCS were 0.5-100.0 µg/L and 1.0-100.0 µg/L, and the correlation coefficients were 0.9997 and 0.9991, respectively. The limits of detection and quantitation of TCC and TCS were 0.17 and 0.33 µg/L, and 0.5 and 1.0 µg/L, respectively. The recoveries of TCC and TCS were 100.1%-102.8% and 96.7%-108.6%, and the relative standard deviations were 4.9%-6.7% and 4.1%-8.3%, respectively, at 2.0, 10.0 and 80.0 µg/L. Conclusion: QuEChERS-UPLC-MS/MS method is simple, rapid, sensitive and reproducible, and can be used for rapid and accurate simultaneous detection of TCC and TCS exposure levels in occupational population.

[Perinatal outcomes and influencing factors following radiofrequency ablation in multiple pregnancies].

Objective: To assess the effectiveness of radiofrequency ablation (RFA) in the treatment of multiple pregnancies. Methods: In this retrospective study, 84 cases (total 174 fetuses) of complex monochorionic pregnancies treated with RFA for selective fetal reduction were analyzed. All cases were managed in the Guangdong Women and Children Hospital from January 2015 to January 2018. Indications for offering RFA, details of the procedure and pregnancy outcomes were collected and analyzed. Results: (1)The rate of miscarriage and fetal intrauterine death was 21% (18/84), termination of pregnancy because of fetal malformation or oligohydramnion occurred in 10% (8/84) of cases. Total live birth rate was 69% (58/84) and the gestation age at delivery was (35.0±3.0) weeks. (2) The live birth rate of twin reversed arterial perfusion sequence (TRAPS) was the lowest (6/11), followed by twin to twin transfusion syndrome (TTTS; 66%, 27/41), structural or genetic abnormalities of one fetus in monochorionic twin pregnancy (10/14), triplet pregnancy reduction (4/6) and selective intrauterine growth restriction (sIUGR) (11/12). (3) The live birth rate was 67% (20/30) in stage Ⅲ of TTTS and 7/11 in the stage Ⅳ of TTTS (P>0.05). The average gestational age was (33.6±3.0) weeks in stage Ⅲ of TTTS compared with (36.5±2.4) weeks in the stage Ⅳof TTTS (P<0.05). Conclusions: RFA appears to be a reliable option for selective fetal reduction in monochorionic multiple pregnancies. The indication of RFA is an influencing factor on its pregnancy outcomes. Type Ⅱand type Ⅲ sIUGR may choose this technique as a priority. Compared with stage Ⅲ of TTTS, the live birth rate and the gestation age at delivery in stage Ⅳ of TTTS, there are no significant differences.

[Prevalence of reproductive system diseases among female workers in a city and related occupational influencing factors: an analysis of 9944 cases].

Objective: To investigate the prevalence of reproductive system diseases among female workers in a city and related occupational influencing factors. Methods: From June to September, 2016, a cross-sectional survey was used to select 9 944 female workers from six districts of Beijing and then a face-to-face questionnaire survey was performed. Univariate analysis using chi-square test and multivariate logistic regression analysis were used to investigate the risk factors for reproductive system diseases. Results: The age of 9944 female workers ranged from 18 to 65 years (mean 35.53±9.52 years) , and among them, 7 351 (73.92%) were married. The overall prevalence rate of reproductive system diseases among these 9944 female workers during the past three months was 28.29%, and the prevalence rates of hyperplasia of mammary glands, vaginitis, and hysteromyoma were 15.54%, 11.25%, and 6.77%, respectively. After adjustment for age, marital status, education level, and annual family income, the multivariate logistic regression analysis showed that frequent overtime work (odds ratio[OR]=1.119, 95% confidence interval[CI]: 1.070-1.343) , frequent night shifts (OR=1.198, 95%CI: 1.054-1.361) , standing for a long time (OR=1.197, 95%CI: 1.063-1.347) , sitting for a long time (OR=1.327, 95%CI: 1.191-1.479) , heavy workload (OR=1.429, 95%CI: 1.262-1.615) , exposure to lead (OR=1.696, 95%CI: 1.307-2.201) , exposure to mercury (OR=1.452, 95%CI: 1.086-1.940) , and exposure to ionizing radiation (OR=1.679, 95%CI: 1.424-1.980) were associated with reproductive system diseases. Conclusion: The prevalence of reproductive system diseases among female workers in Beijing is not optimistic. Reproductive system diseases are associated with frequent overtime work, frequent night shifts, standing for a long time, sitting for a long time, heavy workload, and exposure to lead, mercury, and ionizing radiation.

Clinical significance of Mena and Her-2 expression in breast cancer.

OBJECTIVE: The aim of this study was to determine the expression patterns of Mena and Her-2 in breast cancer tissues and to explore their clinical significance and correlation with clinicopathological parameters. METHODS: The expression of Mena and Her-2 was detected in 40 breast cancer tissues and 14 normal breast tissues by immunohistochemistry, and the relationship of Mena and Her-2 expression with clinicopathological parameters was analyzed. RESULTS: Both Mena (70%) and Her-2 (40%) were more commonly expressed in breast cancer than in normal breast tissue (7.1%, 0%, respectively; p < 0.05); further, Mena and Her-2 expression in breast cancer were positively correlated (r = 0.530, p < 0.05). In comparing expression with clinicopathological parameters of tumor samples, Mena and Her-2 were both associated with axillary lymph node metastasis and TNM stage (p < 0.05), but not with patient age or pathological type. CONCLUSIONS: Mena and Her-2 are related to the malignancy degree and metastasis of breast cancer, and thus may play a coordinating role in the occurrence and progression of breast cancer.

Functional gamma-secretase inhibitors reduce beta-amyloid peptide levels in brain.

Converging lines of evidence implicate the beta-amyloid peptide (Ass) as causative in Alzheimer's disease. We describe a novel class of compounds that reduce A beta production by functionally inhibiting gamma-secretase, the activity responsible for the carboxy-terminal cleavage required for A beta production. These molecules are active in both 293 HEK cells and neuronal cultures, and exert their effect upon A beta production without affecting protein secretion, most notably in the secreted forms of the amyloid precursor protein (APP). Oral administration of one of these compounds, N-[N-(3,5-difluorophenacetyl)-L-alanyl]-S-phenylglycine t-butyl ester, to mice transgenic for human APP(V717F) reduces brain levels of Ass in a dose-dependent manner within 3 h. These studies represent the first demonstration of a reduction of brain A beta in vivo. Development of such novel functional gamma-secretase inhibitors will enable a clinical examination of the A beta hypothesis that Ass peptide drives the neuropathology observed in Alzheimer's disease.

Applications of capillary electrochromatography analysis for formulated pesticide products.

The feasibility of using capillary electrochromatography (CEC) as a high-efficiency reversed-phase separation technique has been demonstrated for the analysis of some pesticide formulation products. Some operating parameters of CEC analysis (organic modifier content, pH of the buffer, and sample diluent) were studied using commercially available capillaries packed with Hypersil (Phenomenex, Torrance, CA, U.S.A.) octadecylsilic (ODS) particles. It was found that the resolution decreases in linear fashion with the increase in percent acetonitrile in the sample diluent for neutral components if a combination of electrokinetic injection and pressure injection is used. Several practical applications of the CEC technique in the analysis of pesticide formulation products are described in detail. The results indicate that CEC, compared with HPLC, not only has higher efficiency, but is also practical, precise, and accurate in terms of simplicity, efficiency, recovery, and linearity.

[The central basis of discrete sampling behavior in the human pupillary control system].

The human pupillary control system was investigated with double-pulse light dichoptic stimulation to explore its discrete sampling behavior. In this dichoptic stimulating method, the first pulse of the double pulse light stimulated one eye, of which the pupil area was recorded, and the second pulse stimulated the other eye (the contralateral eye). The experiment data demonstrated that the pupillary control system requires a minimum time interval, approximately 0.6 s, to elicit next transient response to the second light pulse, even though the two pulses were presented respectively to different eyes of the subject. The result supports the suggestion that the discrete sampling process exists in the pupillary control system. Moreover, it indicates that the minimum time interval is not caused by the retina adaptation, but determined by the central nerve system.

[Dual mode control of head movements during eye-head coordination].

Eye-head coordination during the shift of gaze is investigated. Dynamic trajectories of eye movements and head movements were measured for exploring the control mechanism of the head movement in eye-head coordination. The experimental results revealed the dual mode control of the head movement in eye-head coordination: a linear control for small amplitude movement (less than 30 degree), and a Bang-Bang control for larger amplitude.

[Clinical and experimental study on shenghong kangyan su in treating 144 cases of pelvic inflammation with blood stasis syndrome].

Using the method of clearing up heat and resolving stasis, the authors treated 144 cases of pelvic inflammation with blood stasis syndrome (BSS) with Shenghong Kangyan Su. The total effective rate was up to 97.92%, cure rate up to 68.75%, without toxicity and side effects. Clinical and experimental study showed that the crux of pelvic inflammation with BSS had some relations with microcirculation obstruction. Inflammation may cause microcirculation obstruction and blood stasis, and is one forms of BSS. Therefore dull purple-tongue, undertongue vein dilated, abdominal pain in lower-part, pathologic mass can be regarded as the basis of diagnosis of pelvic inflammation with BSS The drug of clearing heat and resolving status has the functions of anti-inflammation, anti-pain, diminishing the obstruction of microcirculation, particularly in speeding up the blood flowing, lowering the aggregation of erythrocyte, P less than 0.001.

[The binding characteristics of antibody with antigen in enzyme immunosensor].

The enzyme immunosensor developed by Aizawa et al for assaying antigens is regarded as a rapid and accurate method for immunoassay. The key point involved in this technique is the binding force of an antigen with a membrane-bound antibody. In this report, a simplified method was adopted to determine the amount of membrane-bound antibody and the binding constant between antigen and membrane-bound antibody. The plot of C* vs C*/A0* facilitates the determination of binding constant K' and the amount of membrane-bound antibody, B0. From the equations expressing competitive binding reactions of labeled and nonlabeled antigen-antibody reactions, the value of K was determined from the value of K' and relative concentrations of antigen and antigen-antibody complex. The determination of K' and K was exemplified by obtaining the data of anti-IgG and anti-hCG antibodies (immobilized on triacetyl cellulose membrane) with their antigens.