[Predictive value of net water uptake with respect to early neurological improvement after endovascular treatment in patients with acute anterior circulation large vessel occlusion stroke].

Objective: To investigate the value of net water uptake (NWU) for predicting early neurological improvement (ENI) after endovascular treatment in patients with acute anterior circulation large vessel occlusion stroke. Methods: A case-control study. A total of 132 patients (80 men, 52 women, median age 68 years) with acute anterior circulation large vessel occlusive stroke receiving endovascular treatment were retrospectively analyzed at Jinling Hospital from October 2014 to September 2019. Patients were divided into two groups based on the occurrence of ENI, which was defined as either an improvement of NIHSS score of ≥4 points, or an NIHSS score of 0 or 1 at 24 hours after endovascular treatment. The rank sum test, Chi square test, and other methods were used to compare differences in baseline characteristics between the two groups. Logistic regression analysis was used to investigate independent predictors of postoperative ENI. Receiver operating characteristic curve analysis used to assess the capacity of NWU to predict ENI. Results: Of the 132 patients in the study, ENI occurred in 47 and did not occur in 85. In multivariate logistic regression analysis age [odds ratio (OR)=0.940, 95% confidence interval (CI) 0.903-0.979, P=0.003], time from stroke onset to puncture (OR=0.995, 95%CI 0.991-0.999, P=0.025), time from puncture to recanalization/end of operation (OR=0.985, 95%CI 0.974-0.996, P=0.007), NWU (OR=0.762, 95%CI 0.620-0.937, P=0.010), and mTICI (OR=1.644, 95%CI 1.043-2.590, P=0.032) were predictive factors for ENI. Receiver operating characteristic curve analysis indicated that NWU could effectively predict ENI (area under the curve=0.642, 95%CI 0.543-0.741, P=0.007), and prediction accuracy was improved when it was combined with other clinical parameters. Conclusion: NWU is an independent predictor of ENI in patients with acute anterior circulation large vessel occlusive stroke undergoing endovascular treatment.

[Establishment of a rapid risk assessment system for imported COVID-19 cases].

Objective: To develop a rapid risk assessment tool for imported COVID-19 cases and provide reference evidences for prevention and control of COVID-19 at ports. Methods: The information about COVID-19 pandemic and control strategies of 12 concerned countries was collected during July to August 2021, and 12 indexes were selected to assess the importation risk of COVID-19 by risk matrix. Results: The risk for imported COVID-19 cases from 12 countries to China was high or extremely high, and the risk from Russia and the USA was highest. Conclusions: The developed rapid risk assessment tool based on the risk matrix method can be used to determine the risk level of countries for imported COVID-19 cases to China at ports, and the risk of imported COVID-19 was high at Beijing port in August 2021.

Effects of kisspeptin-10 on the reproductive performance of sows in a fixed-time artificial insemination programme.

Kisspeptin (KP) is a major positive regulator of the hypothalamo-pituitary-gonadal axis and affects female reproductive cyclicity in mammals. It offers an attractive alternative strategy to control reproduction in fixed-time artificial insemination (FTAI) protocols. We aimed to evaluate the effects of different doses of kisspeptin-10 (KP-10) on sow reproductive performance in FTAI protocols. One hundred ninety-eight weaned sows were divided into three groups at random. A FTAI-GnRH group of sows (n = 98) received 100 µg (2 mL) gonadotropin-releasing hormone (GnRH; gonadorelin) by intramuscular injection at 96 h after weaning (t = 0 h); FTAI-KPL (KPL: low-dose KP-10, n = 50), and FTAI-KPH groups of sows (KPH: high-dose KP-10, n = 50) received 0.5 or 1 mg KP-10 (2 mL) respectively at 96 h after weaning. Sows were checked twice daily for oestrus. Ultrasonographic evaluations were performed to determine the follicular diameter and time of ovulation; blood samples were collected immediately before injection (t0 = 0 min) and at 15, 30, 45, 60, 75, 90 min, 24 and 48 h postinjection. Sows were inseminated at 112 and 132 h after weaning. The oestrus rates (96 vs 92%; 96 vs 88%) and weaning-to-oestrus intervals (98.9 vs 98.6 h; 98.9 vs 97.1 h) were not affected by treatment, but oestrus in the FTAI-KPL group was significantly longer than in the FTAI-GnRH group (38.7 vs 30.0 h; P < 0.05). The peak LH concentrations were 1.29 times greater than at t0 = 0 in the FTAI-GnRH group, and 1.45 and 1.44 times greater than at t0 = 0 in the FTAI-KPL and FTAI-KPH groups, respectively. Follicular diameters and pregnancy rates (86 vs 88%, 86 vs 80%, respectively) did not differ between the treatments. Moreover, the total numbers of piglets born and those born alive did not differ among the three groups. These findings suggested that 0.5 mg KP-10 given at 96 h after weaning could be used in FTAI programmes to manage batch farrowing in sows.

A comparison of the reproductive performance in primiparous sows following two timed artificial insemination protocols.

Timed artificial insemination (TAI) is an efficient reproductive technology in batch farrowing production that aids management in pig farms. However, the effect of TAI on the reproduction performance is still controversial. This study aimed to evaluate the effects of two TAI protocols on the reproductive performance of primiparous sows. A total of 332 weaned sows were randomly allocated into three treatments. Sows assigned to Control (n = 110) were untreated and inseminated on each day in oestrus after weaning. Sows assigned to eG-TAI (n = 112) received equine chorionic gonadotropin (eCG) 24 h after weaning and gonadotropin-releasing hormone (Gonadorelin: GnRH) at oestrus, and were inseminated at 8 and 32 h later if oestrus at 0800, or 16 and 40 h later if oestrus at 1600. Sows assigned to 2e-TAI (n = 110) received eCG and GnRH 24 h and 96 h after weaning, respectively, and were inseminated 16 and 40 h after GnRH administration. Sows showing oestrus at GnRH administration or 64 h after were inseminated immediately, for a total of three inseminations. Ultrasonographic evaluations were performed to determine the follicular diameter and time of ovulation. Most sows in the 2e-TAI and eG-TAI groups ovulated 0-48 h after the GnRH injection. Our results indicated that oestrus rate within seven days after weaning in the experimental groups was higher, and weaning-to-oestrus interval was shorter than in the control group (99.3 h vs 113.5 h, P < 0.05). The breeding and farrowing rates in the experimental groups were significantly higher than in the control group (P < 0.05), while the numbers of total born, live-born and stillborn were not different among the three groups (Control: 12.7, 11.6 and 1.1; 2e-TAI: 12.4, 11.3 and 1.0; eG-TAI: 12.0, 11.4 and 0.4, respectively). These results indicated that TAI could ensure a high farrowing rate in primiparous sows under batch farrowing management.

Effects of red blood cell aggregation on the blood flow in a symmetrical stenosed microvessel.

In order to figure out whether red blood cell (RBC) aggregation is beneficial or deleterious for the blood flow through a stenosis, fluid mechanics of a microvascular stenosis was examined through simulating the dynamics of deformable red blood cells suspended in plasma using dissipative particle dynamics. The spatial variation in time-averaged cell-free layer (CFL) thickness and velocity profiles indicated that the blood flow exhibits asymmetry along the flow direction. The RBC accumulation occurs upstream the stenosis, leading to a thinner CFL and reduced flow velocity. Therefore, the emergence of stenosis produces an increased blood flow resistance. In addition, an enhanced Fahraeus-Lindqvist effect was observed in the presence of the stenosis. Finally, the effect of RBC aggregation combined with decreased stenosis on the blood flow was investigated. The findings showed that when the RBC clusters pass through the stenosis with a throat comparable to the RBC core in diameter, the blood flow resistance decreases with increasing intercellular interaction strength. But if the RBC core is larger and even several times than the throat, the blood flow resistance increases largely under strong RBC aggregation, which may contribute to the mechanism of the microthrombus formation.

Modeling Cell Adhesion and Extravasation in Microvascular System.

The blood flow behaviors in the microvessels determine the transport modes and further affect the metastasis of circulating tumor cells (CTCs). Much biochemical and biological efforts have been made on CTC metastasis; however, precise experimental measurement and accurate theoretical prediction on its mechanical mechanism are limited. To complement these, numerical modeling of a CTC extravasation from the blood circulation, including the steps of adhesion and transmigration, is discussed in this chapter. The results demonstrate that CTCs prefer to adhere at the positive curvature of curved microvessels, which is attributed to the positive wall shear stress/gradient. Then, the effects of particulate nature of blood on CTC adhesion are investigated and are found to be significant in the microvessels. Furthermore, the presence of red blood cell (RBC) aggregates is also found to promote the CTC adhesion by providing an additional wall-directed force. Finally, a single cell passing through a narrow slit, mimicking CTC transmigration, was examined under the effects of cell deformability. It showed that the cell shape and surface area increase play a more important role than the cell elasticity in cell transit across the narrow slit.

N-octanoylated ghrelin peptide inhibits bovine oocyte meiotic resumption.

BACKGROUND: Studies have shown that ghrelin plays an important role in the mammalian reproductive system, including the central, gonadal levels, and also during in vitro maturation of oocytes; however, the functions of ghrelin in bovine oocyte meiosis require further investigation. OBJECTIVE: We aimed to evaluate the effects of an n-octanoylated ghrelin peptide on oocyte meiotic resumption and the developmental competence of mature oocytes in vitro. EXPERIMENTAL: design: The expression of GHRL (encoding ghrelin) mRNA and its receptor (the growth hormone secretagogue receptor, GHSR) in the cumulus-oocyte complex (COCs), denuded oocytes (DOs), and cumulus cells (CCs) was assessed using quantitative real-time reverse transcription PCR (qRT-PCR), and the effects of the n-octanoylated ghrelin peptide on meiotic resumption were studied at four different doses (0, 10, 50, and 100 ng/mL) in a 6 h culture system. RESULTS: qRT-PCR analysis showed that GHRL and GHSR mRNAs were expressed in all tested samples; however, GHRL was predominantly expressed in DOs, and GHSR was predominantly expressed in CCs. Germinal vesicle breakdown was inhibited significantly by 50 ng/mL ghrelin compared with that in the negative control (P < 0.05). Further studies showed that n-octanoylated ghrelin increased the levels of cAMP and cGMP in the CCs and DOs, which inhibited the meiotic resumption of bovine oocytes. And the inhibitory role in the developmental competence of mature oocytes were also included, ghrelin could significantly improve the cleavage rate (P < 0.05) and blastocyst rate (P < 0.05). CONCLUSION: N-octanoylated ghrelin maintained bovine oocytes meiotic arrest and further improved their developmental competence; therefore, n-octanoylated ghrelin could be considered as a potential pharmaceutical inhibitor of meiosis for the in vitro maturation of bovine oocytes.

[Effect of Gas6 in silica-induced inflammation on differentiated human acute monocytic leukemia (THP-1) macrophages].

Objective: To investigate the modulation role of Gas6 in silica-induced inflammatory effect on human macrophages. Methods: Differentiated THP-1 macrophages were exposed to different concentrations of silica for 6 h and 24 h. Additionally, silica-activated macrophages were treated with different concentrations of recombine human Gas6 and Gas6 antibody respectively. Cell viabilities were determined by CCK-8 kit. Expression levels of Gas6 and inflammatory cytokines (TNF-α, IL-1ß and IL-6) were measured by ELISA assay kits. Results: Silica particles induced clear dose-dependent decreases of cell viability and Gas6 expression at both 6 h and 24 h. The cell viability of 24 h is lower than 6 h at the same concentration of silica (P<0.05). Furthermore, silica activated macrophages treated with Gas6 antibody induced significant decreases of Gas6 both at 6 h and 24 h (P<0.05). After pretreated with various concentrations of Gas6 antibody, silica induced higher expressions of inflammatory cytokines (TNF-α, IL-1ß, IL-6) in dose-dependent manners at two time points. Addition of exoge-nous Gas6 significantly suppressed silica-induced inflammatory cytokines concentrations mentioned above in the cell culture supernatants in clear dose-dependent manners. Conclusion: Exogenous Gas6 could inhibit the secre-tion of inflammatory cytokines in macrophages, while the block of Gas6 might enhance this inflammation.

Effects of flowing RBCs on adhesion of a circulating tumor cell in microvessels.

Adhesion of circulating tumor cells (CTCs) to the microvessel wall largely depends on the blood hydrodynamic conditions, one of which is the blood viscosity. Since blood is a non-Newtonian fluid, whose viscosity increases with hematocrit, in the microvessels at low shear rate. In this study, the effects of hematocrit, vessel size, flow rate and red blood cell (RBC) aggregation on adhesion of a CTC in the microvessels were numerically investigated using dissipative particle dynamics. The membrane of cells was represented by a spring-based network connected by elastic springs to characterize its deformation. RBC aggregation was modeled by a Morse potential function based on depletion-mediated assumption, and the adhesion of the CTC to the vessel wall was achieved by the interactions between receptors and ligands at the CTC and those at the endothelial cells forming the vessel wall. The results demonstrated that in the microvessel of [Formula: see text] diameter, the CTC has an increasing probability of adhesion with the hematocrit due to a growing wall-directed force, resulting in a larger number of receptor-ligand bonds formed on the cell surface. However, with the increase in microvessel size, an enhanced lift force at higher hematocrit detaches the initial adherent CTC quickly. If the microvessel is comparable to the CTC in diameter, CTC adhesion is independent of Hct. In addition, the velocity of CTC is larger than the average blood flow velocity in smaller microvessels and the relative velocity of CTC decreases with the increase in microvessel size. An increased blood flow resistance in the presence of CTC was also found. Moreover, it was found that the large deformation induced by high flow rate and the presence of aggregation promote the adhesion of CTC.

[Association of urinary metals and lung function in general Chinese population of Wuhan].

OBJECTIVE: To investigate the association between levels of 23 urinary metals and lung function, and explore their does-response relationships in the general population of Wuhan province, China. METHODS: This was a cross-sectional study that enrolled volunteers from two communities of Wuhan between April and May 2011. All volunteers had resided in Wuhan for at least 5 years. Information from questionnaires and physical examinations were collected and lung function was assessed. Data from 2 540 volunteers were included. Urinary levels of 23 metals were measured by inductively coupled plasma mass spectrometry (ICP-MS). The relationship between urinary metals and lung function was analyzed with single and multiple regression models. RESULTS: The mean age of the study population was 52.8 years. Mean levels of urinary metals, after adjustment for creatinine, including cobalt, copper, zinc, nickel, antimony and barium were 0.02, 0.68, 23.80, 0.20, 0.10, 0.34 and 0.26 µg/g creatinine, respectively. There were significant concentration-response relationships between increases in some urinary metals and reduced lung function. Single-metal regression models demonstrated that for each 1-unit increase in urinary levels of cobalt, lncopper, lnzinc, lnantimony, there was a reduction in forced vital capacity (FVC) of 0.091 L (95%CI: -0.155--0.027), 0.101 L (95%CI: -0.178--0.025), 0.094 L (95%CI: -0.172--0.027) and 0.118 L (95% CI: -0.203--0.033), respectively. Each 1-unit-increase in urinary lncobalt, lnnickel, lnstrontium, lnantimony, lnthallium, lnlead was associated with a reductions in forced expiratory volume in 1 sec (FEV1) of 0.070 L (95%CI: -0.124--0.016), 0.063 L (95%CI: -0.118--0.007), 0.063 L (95%CI: -0.124--0.002), 0.092 L (95%CI: -0.164--0.020), 0.055 L (95%CI: -0.105--0.005), 0.081 L (95%CI: -0.148--0.014), and 0.097 L (95% CI: -0.151--0.042), respectively. With respect to metal co-exposure, FVC was significantly associated with elevated urinary levels of cobalt, Cu and Sb, with reductions of 0.126 L (95%CI: 0.037-0.216) and 0.106 L (95% CI: 0.021-0.192), respectively, while FEV1 was significantly associated with elevated urinary Co, Sb, Ba and Pb, with reductions of 0.067 L (95% CI: -0.129--0.005), 0.142 L (95% CI: -0.247--0.037), 0.073 L (95% CI: -0.142--0.003) and 0.104 L (95% CI: -0.175--0.034), respectively. CONCLUSIONS: Certain urinary metals were potentially associated, in a dose-dependent manner, with reduced lung function in the general population. Co-exposure to metals had stimulative and anti-stimulative effects on lung function.

Numerical simulation of a single cell passing through a narrow slit.

The narrow slit between endothelial cells that line the microvessel wall is the principal pathway for tumor cell extravasation to the surrounding tissue. To understand this crucial step for tumor hematogenous metastasis, we used dissipative particle dynamics method to investigate an individual cell passing through a narrow slit numerically. The cell membrane was simulated by a spring-based network model which can separate the internal cytoplasm and surrounding fluid. The effects of the cell elasticity, cell shape, nucleus and slit size on the cell transmigration through the slit were investigated. Under a fixed driving force, the cell with higher elasticity can be elongated more and pass faster through the slit. When the slit width decreases to 2/3 of the cell diameter, the spherical cell becomes jammed despite reducing its elasticity modulus by 10 times. However, transforming the cell from a spherical to ellipsoidal shape and increasing the cell surface area by merely 9.3 % can enable the cell to pass through the narrow slit. Therefore, the cell shape and surface area increase play a more important role than the cell elasticity in cell passing through the narrow slit. In addition, the simulation results indicate that the cell migration velocity decreases during entrance but increases during exit of the slit, which is qualitatively in agreement with the experimental observation.

Simulation of a single red blood cell flowing through a microvessel stenosis using dissipative particle dynamics.

The motion and deformation of a single red blood cell flowing through a microvessel stenosis was investigated employing dissipative particle dynamics (DPD) method. The numerical model considers plasma, cytoplasm, the RBC membrane and the microvessel walls, in which a three dimensional coarse-grained spring RBC. The suspending plasma was modelled as an incompressible Newtonian fluid and the vessel walls were regarded as rigid body. The body force exerted on the free DPD particles was used to drive the flow. A modified bounce-back boundary condition was enforced on the membrane to guarantee the impenetrability. Adhesion of the cell to the stenosis vessel surface was mediated by the interactions between receptors and ligands. Firstly, the motion of a single RBC in a microfluidic channel was simulated and the results were found in agreement with the experimental data cited by [1]. Then the mechanical behavior of the RBC in the microvessel stenosis was studied. The effects of the bending rigidity of membrane, the size of the stenosis and the driven body force on the deformation and motion of red blood cell were discussed.

Lack of association between HLA-A, -B and -DRB1 alleles and the development of SARS: a cohort of 95 SARS-recovered individuals in a population of Guangdong, southern China.

Severe acute respiratory syndrome (SARS), caused by infection with a novel coronavirus (SARS-CoV), was the first major novel infectious disease at the beginning of the 21st century, with China especially affected. SARS was characterized by high infectivity, morbidity and mortality, and the confined pattern of the disease spreading among the countries of South-East and East Asia suggested the existence of susceptible factor(s) in these populations. Studies in the populations of Hong Kong and Taiwan showed an association of human leucocyte antigen (HLA) polymorphisms with the development and/or severity of SARS, respectively. The aim of the present study was to define the genotypic patterns of HLA-A, -B and -DRB1 loci in SARS patients and a co-resident population of Guangdong province, southern China, where the first SARS case was reported. The samples comprised 95 cases of recovered SARS patients and 403 unrelated healthy controls. HLA -A, -B and -DRB1 alleles were genotyped using polymerase chain reaction with sequence-specific primers. The severity of the disease was assessed according to the history of lung infiltration, usage of assisted ventilation and occurrence of lymphocytopenia. Although the allelic frequencies of A23, A34, B60, DRB1*12 in the SARS group were slightly higher, and A33, -B58 and -B61 were lower than in the controls, no statistical significance was found when the Pc value was considered. Similarly, no association of HLA alleles with the severity of the disease was detected. Thus, variations in the major histocompatibility complex are unlikely to have contributed significantly to either the susceptibility or the severity of SARS in the population of Guangdong.