[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.

Incremental value of enhanced plaque length for identifying intracranial atherosclerotic culprit plaques: a high-resolution magnetic resonance imaging study

OBJECTIVES

Besides plaque enhancement grade, the incremental value of enhancement-related high-resolution MRI features in defining culprit plaques needs further evaluation. This study was focused on assessing whether plaque enhancement features contribute to culprit plaque identification and further risk stratification.

METHODS

We retrospectively studied patients who experienced an acute ischaemic stroke and transient ischaemic attack due to intracranial atherosclerosis from 2016 to 2022. The enhancement features included enhancement grade, enhanced length, and enhancement quadrant. Associations between plaque enhancement features and culprit plaques, as well as diagnostic value, were investigated using logistic regression and receiver operating characteristic analyses.

RESULTS

Overall, 287 plaques were identified, of which 231 (80.5%) and 56 (19.5%) were classified as culprit and non-culprit plaques, respectively. Comparison of the pre- and post-enhancement images revealed enhanced length longer than the plaque length in 46.32% of the culprit plaques. Multivariate logistic regression showed that enhanced length longer than plaque length (OR 6.77; 95% CI 2.47-18.51) and grade II enhancement (OR 7.00; 95% CI 1.69-28.93) were independently associated with culprit plaques. The area under the curve value for the combination of stenosis and plaque enhancement grade for the diagnosis of culprit plaques was 0.787, which increased significantly to 0.825 on the addition of enhanced length longer than the plaque length (p = 0.026 for DeLong's test).

CONCLUSIONS

Enhanced length longer than the plaque length and grade II enhancement were independently associated with culprit plaques. The combination of the enhanced plaque features resulted in better culprit plaque identification.

[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.

ASPECTS-Based Attenuation Changes on CT Angiography as an Imaging Biomarker to Predict Hemorrhagic Transformation in Acute Ischemic Stroke

INTRODUCTION

Imaging-based early warning indicators and feasible stratification of acute ischemic stroke (AIS) patients with hemorrhagic transformation (HT), especially high-risk patients with parenchymal hematoma (PH), are crucial in determining subsequent treatment strategies. This study combined automated ASPECTS software with noncontrast CT (NCCT) and CTA source image (CTASI) attenuation changes using Hounsfield unit (HU) values to predict HT and PH in patients with AIS.

MATERIALS AND METHODS

We retrospectively enrolled 172 consecutive patients with anterior circulation large-vessel occlusion between 2016 and 2020. Univariate and multivariate logistic regression and receiver operating characteristic (ROC) analyses were used to investigate the relationship between NCCT and CTASI-ASPECTS-HU, as well as other clinical and radiological parameters of HT and PH. Univariate and multivariate logistic regression analyses were performed to explore risk factors for HT or PH, and an ROC curve was used to evaluate their diagnostic values.

RESULTS

A multivariate analysis showed that CTASI-ASPECTS-HU and NIHSS score were independent predictors of HT (CTASI-ASPECTS-HU: odds ratio (OR), 2.22; 95% CI, 1.01-4.92; NIHSS: OR, 1.07; 95% CI, 1.02-1.13) and PH (CTASI-ASPECTS-HU: OR, 6.51; 95% CI, 2.29-18.50; NIHSS: OR, 1.07; 95% CI, 1.01-1.13). According to ROC analysis, CTASI-ASPECTS-HU >0.09 identified HT (area under the curve, 0.70; sensitivity, 70.15%; specificity, 61.90%), and CTASI-ASPECTS-HU >0.10 identified PH (area under the curve, 0.79; sensitivity, 76.19%; specificity, 73.33%). The area under the curve for predicting HT or PH increased when CTASI-ASPECTS-HU was combined with NIHSS score (HT: area under the curve, 0.74; sensitivity, 73.13%; specificity, 70.48%; PH: area under the curve, 0.81; sensitivity, 85.71%; specificity, 72.38%).

CONCLUSION

CTASI-ASPECTS-HU is a reliable radiological predictor of HT and PH in patients with AIS. Its predictive efficacy is moderately improved when combined with NIHSS score.

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.

ASPECTS-based net water uptake as an imaging biomarker for lesion age in acute ischemic stroke

OBJECTIVE

We assessed the value of computed tomography (CT) and automated Alberta Stroke Program Early CT Score (ASPECTS) with net water uptake (NWU) to predict stroke onset time.

METHODS

Two-hundred forty stroke patients with anterior circulation large-vessel occlusion were included. CT-ASPECTS-NWU values were calculated by comparing the mean Hounsfield units of affected ASPECTS regions with unaffected contralateral regions. The correlation between ASPECTS-NWU and stroke onset to CT time was assessed. ASPECTS-NWU predictive values were calculated to identify a stroke onset to CT time of within 4.5/6 h.

RESULTS

A correlation existed between stroke onset to CT time and ASPECTS-NWU (r = 0.65, p < 0.001), which was affected by collateral status and infarct location. The area under the receiver operating characteristic (ROC) curve (AUC) for distinguishing a stroke onset to CT time of within 4.5 h was 0.837 (95% confidence interval [CI] 0.784-0.881; optimal cutoff 7%; sensitivity 87.10%; specificity 62.36%). The multi-index AUC was 0.884 (95% CI 0.837-0.922). The AUC for distinguishing a stroke onset to CT time of within 6 h was 0.836 (95% CI 0.783-0.880; optimal cutoff 9%; sensitivity 72.73%; specificity 81.16%). The multi-index AUC was 0.881 (95% CI 0.834-0.920).

CONCLUSIONS

ASPECTS-NWU may be used to determine stroke onset time in patients with unwitnessed or wake-up stroke.

Two Series of Main-Group Heterometallic Selenides Synthesized in Two Different Types of Ionic Liquids

Imidazolium-based ionic liquids have been widely applied in the synthesis of organic hybrid chalcogenidometalates, while the other types of ionic liquids are rarely tried. Reported here is the first application of a pyridinium-based ionic liquid in the preparation of two main-group heterometallic selenides featuring isomorphic three-dimensional frameworks. Of particular interest is that three gallium-tin selenides possessing another type of three-dimensional framework have been prepared by replacing the pyridinium-based ionic liquid with imidalolium-based ionic liquids under the same reaction conditions.

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.

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.

[Genotyping of RhD-negative blood samples diagnosed by serological tests from patients waiting for kidney transplantation]

OBJECTIVE

To compare the accuracy of serological and molecular approaches to identification of RhD-negative patients waiting for kidney transplantation.

METHODS

A total of 103 RhD-negative blood samples by serological test were collected from patients waiting for kidney transplantation between January, 2006 and January, 2016. Quantitative PCR and sequencing were used to verify the results of RHD genotyping, and the false negative rates of the serological and molecular methods for RhD genotyping were compared.

RESULTS

Among the 103 blood samples, true RhD negativity (with all the 10 exons missing) was found in 56 samples (54.5%), and false RhD negativity (RhD positivity with loss, repetition, or missense mutation in the 10 exons) in 47 samples (45.6%). In the 47 false RhD-negative cases, weak D was detected in 1 case (2.1%), partial D in 13 cases (27.7%), and D-elution in 33 cases (70.2%). The detection rates of RhD negativity differed significantly between the serological and molecular methods (P<0.05).

CONCLUSION

Serological test is associated with a high false negative rate in detecting RhD blood group, and the use of the molecular approach has important clinical significance in accurate RhD genotyping for patients waiting for renal transplantation.

[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-1β 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-1β, 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.

[ROC curve-based evaluation of platelet parameters for predicting delayed renal graft function]

OBJECTIVE

To investigate the value of evaluating 5 platelet parameters in predicting delayed graft function (DGF) in patients following kidney transplantation.

METHODS

We retrospectively analyzed the pre- and postoperative (within 2 months) data of 330 renal transplant recipients. The cases with DGF and those without were analyzed to assess the association between relationship between DGF following transplantation and the variations of blood platelet parameters including platelet count (PLT), large platelet ratio (P-LCR), mean platelet volume (MPV), platelet volume distribution width (PDW) and platelet hematocrit (PCT).

RESULTS

The DGF and non-DGF cases were comparable for the platelet parameters before the operation. On postoperative day 7 when the diagnosis of DGF was made, PLT (P<0.05) and PCT (P<0.02) were significantly lower while MPV (P<0.01), PDW (P=0.036) and P-LCR (P=0.01) significantly higher in DGF group than in non-DGF group. The AUCs of P-LCR (0.611±0.047), PDW (0.603±0.048) and MPV (0.762±0.037) were significantly higher than the reference area (P<0.05) with cut-off values of 34.80%, 12.95fl and 11.55fl, respectively. MPV showed a high sensitivity, specificity and Youden index for predicting DFG; PDW and P-LCR had a high sensitivity but a low specificity for predicting DFG with a modest diagnostic value. PLT and PCT, with AUCs of were 0.37 and 0.38, respectively, did not have a predictive value for DGF.

CONCLUSIONS

Significant variations in platelet parameters occur in the event of DGF in renal transplant recipients, and monitoring the postoperative changes in MPV, PDW, and P-LCR can help in early diagnosis and treatment of DGF. MPV has a moderate value (0.7-0.9) in predicting DGF, and a MPV>11.55 fl suggests the risk of DGF.

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.

HLA-DRB1 alleles are associated with the susceptibility to sporadic Parkinson's disease in Chinese Han population

Immune disorders may play an important role in the pathogenesis of Parkinson's disease (PD). Recently, polymorphisms in the HLA-DR region have been found to be associated with sporadic PD in European ancestry populations. However, polymorphisms in the HLA complex are highly variable with ethnic and geographic origin. To explore the relationships between polymorphisms of the HLA-DR region and sporadic PD in Chinese Han population, we genotyped 567 sporadic PD patients and 746 healthy controls in two independent series for the HLA-DRB1 locus with Polymerase chain reaction-sequence based typing(PCR-SBT). The χ(2) test was used to evaluate the distribution of allele frequencies between the patients and healthy controls. The impact of HLA-DRB1 alleles on PD risk was estimated by unconditional logistic regression. We found a significant higher frequency of HLA-DRB1*0301 in sporadic PD patients than in healthy controls and a positive association, which was independent of onset age, between HLA-DRB1*0301 and PD risk. Conversely, a lower frequency of HLA-DRB1*0406 was found in sporadic PD patients than in healthy controls, with a negative association between HLA-DRB1*0406 and PD risk. Furthermore, a meta-analysis involving 195205 individuals was conducted to summarize the frequencies of these two alleles in populations from various ethnic regions, we found a higher frequency of HLA-DRB1*0301, but a lower frequency of HLA-DRB1*0406 in European ancestry populations than that in Asians, this was consistent with the higher prevalence of sporadic PD in European ancestry populations. Based on these results, we speculate that HLA-DRB1 alleles are associated with the susceptibility to sporadic PD in Chinese Han population, among them HLA-DRB1*0301 is a risk allele while the effect of HLA-DRB1*0406 deserves debate.

[Relationship between polymorphism of HLA-A, -B, -DRB1 alleles and susceptibility of children to acquired aplastic anemia]

The aim of this study was to identify the relationship between susceptibility of children to acquired aplastic anemia (AA) and HLA-A, -B, -DRB1 alleles. 80 children with AA were enrolled in this study. Among of them, 34 patients collected from tissue typing test centers of Nanfang Hospital; 46 patients were diagnosed at Department of Pediatrics of Sun Yat-Sen Memorial Hospital. In these patients, 48 were males, 32 were females, and with average age 8.1 years old, 6 cases were non-severe AA (nSAA), 74 case were severe AA (SAA). The healthy control group consisted of 109 donors who were from the same area. All the patients and healthy controls were of Han Chinese, and all were unrelated individuals. The polymerase chain reaction sequence specific primers (PCR-SSP) was used to analyze the polymorphism of HLA-A, -B and -DRB1 alleles. Pearson Chi-square or continuity correction or two-sided Fisher's exact test were used. The results showed that the genotype frequency of HLA-B*48:01 and DRB1*09:01 were significantly higher in children with AA as compared with healthy controls (P < 0.05). The genotype frequency of HLA-B*51:01, DRB1*03:01 and DRB1*11:01 were significantly lower in children with AA as compared with healthy controls (P < 0.05). Besides, the results also demonstrated that the genotype frequencies of HLA-B*48:01 and DRB1*09:01 were significantly higher in SAA as compared with controls, the genotype frequencies of B*51:01, DRB1*03:01 and DRB1*11:01 were significantly lower in SAA, as compared with controls. In conclusion, HLA-B*48:01 and DRB1*09:01 are related with children AA, and may be susceptible alleles to the development of children AA. Besides, the expression of HLA-B*51:01, DRB1*03:01 and DRB1*11:01 are low in children with AA, whether they are relative protection alleles of children needs to be further studied.

[Anti-MICA antibodies: risk factors for sensitization and the impact on renal transplantation outcomes]

OBJECTIVE

To investigate the risk factors for sensitization of anti-MICA antibodies and their impact on the outcomes of renal transplantation.

METHODS

Luminex flow cytometry were used to identify 10 MICA antibodies and evaluate the antibody specificity in 98 uremic patients positive or negative for anti-MICA antibodies undergoing kidney transplantation. The factors contributing to MICA sensitization were analyzed, and the incidence of acute rejection and graft function recovery time were compared between the positive and negative cases for anti-MICA antibodies.

RESULTS

Of the 98 uremic patients, 16 (16.3%) were positive for anti-MICA antibodies. The positive and negative cases showed significant differences in the history of blood transfusion, pregnancy, transplantation, and PRA status (P<0.05). In the 38 renal transplant recipients, 6 experienced acute graft rejection, which was reversed by methylprednisolone pulse therapy; of the 10 recipients positive for anti-MICA antibodies, 4 showed acute graft rejection as compared to 2 out of the 28 recipients negative for anti-MICA antibodies (P=0.031). The cases positive for anti-MICA antibodies showed a significantly longer graft function recovery time than the negative cases (14.6∓4.7 vs 8.2∓4.5 days, P=0.001).

CONCLUSIONS

Blood transfusion, pregnancy, and transplantation all contribute to the production of anti-MICA antibodies. Patients positive for anti-MICA antibodies may require strict HLA matching and more potent immunosuppressive drugs to prevent renal graft rejection and improve graft survival.

[Expression of major histocompatibility complex class I-related chain A antibody in patients with end-stage renal disease and its clinical implications]

OBJECTIVE

To study the frequency of major histocompatibility complex class I-related chain A (MICA) antibody in patients with end-stage renal disease (ESRD).

METHODS

Luminex flow cytometry and beads loaded with 11 MICA antigens were used to identify the MICA antibody and evaluate the antibody specificity in 110 patients with ESRD.

RESULTS

The positivity rate of MICA antibody was 40% (12/30) in PRA-positive patients, significantly higher than the rate of 17.5% (14/80) in PRA-negative patients (chi(2)=6.120, P=0.013). MICA-specific antibodies against 10 of the 11 MICA antigens were detected in 26 MICA antibody-positive patients, and 26.92% of the MICA antibody-positive patients had antibodies with single-specificity and 73.08% had polyspecific antibodies. Three MICA antibody-positive patients with cadaveric kidney transplantation showed good function of the graft without acute rejection 2 months after the operation.

CONCLUSION

The positivity rate of MICA antibody is significantly higher in PRA-positive patients, suggesting a strong correlation between MICA and PRA positivity. The MICA antibodies are polyspecific and probably consist of IgM and IgG. These data can be used as prospective data for these ESRD patients considering potential renal transplantation, and may facilitate further investigation of the association of MICA with renal transplantation.

[Expression and analysis of HLA-A, B and DRB1 genes in patients with chronic myelogenous leukemia in Guangdong area]

To study the gene polymorphism of HLA-A, B, DRB1 alleles in patients with chronic myelogenous leukemia and to explore the correlation of HLA with chronic myelogenous leukemia, the polymerase chain reaction-reverse sequence specific oligonucleotide (PCR-RSSO) was used to analyze the polymorphism of HLA-A, B, DRB1 alleles of 293 CML Patients and 406 randomized and synchronous blood donors (healthy and unrelated with patients) from Guangdong Han population. The results indicate that the gene frequency of HLA-A*24 in CML group was 15.53% lower than that of control group (22.09%, RR = 0.63, p = 0.005); the gene frequency of HLA-B*13 in CML group was 10.41% higher than that of control group (6.74%, RR = 1.68, p = 0.016). The gene frequency of HLA- DRB1*14 in CML group was 7.51% lower than that of control group (11.89%, RR = 0.58, p = 0.008). The differences were all statistically significant. It is concluded that the gene frequency of HLA-A*24, HLA- DRB1*14 in CML patients is significantly lower than normal people in Guangdong. The gene frequency of HLA-B*13 in CML patients is significantly higher than normal people in Guangdong. Further study is needed to make sure whether HLA-A*24 and HLA- DRB1*14 are protective gene markers for CML acquisition on Guangdong Chinese Han population and whether HLA-B*13 is a gene marker for CML susceptibility on this population.

[Analysis of STR loci expression after allogeneic cord blood hematopoietic stem cell transplantation]

The purpose of this study was to analyze the STR loci expression after allergenic cord hematopoietic stem cell transplantation in patient with Ducennes muscular dystropy (DMD) patient. PCR-SSO was used to identify the HLA antigens and alleles, STR-PCR was used to detect the chimera status. Quantity analysis of donor chimeras was performed by multiplex PCR amplification of STR marker and capillary electrophoresis with fluorescence detection. The results showed that patient appear to be HLA identical to the donor cord blood at the tested level. Persistent full donor chimerism was found in breast bone marrow. The patient with stable MC (DC < 5%) had a probability of long term survival with molecular remission MC status appeared in forearm muscle, tongue, liver, spleen, stomach, right temporal lobe, diaphragmatic muscle, bronchus, left ventricle and right kidney. In conclusion, the donor gene can express in parenchymatoas organs, the donor chimerism was detected in breast bone marrow and some other organs.

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.

[Induced differentiation of human cord blood monocytes into neuron-like cells in vitro]

OBJECTIVE

To probe the conditions for inducing human cord blood monocytes to differentiate into neuron-like cells.

METHODS

The mononuclear cells were isolated from human umbilical cord blood samples and plated in 25-mm culture flasks containing DMEM/F12 medium. The fifth passage of mesenchymal stem cells (MSCs) were induced by beta-mercaptoe- thanol (beta-ME), dimethyl sulfoxide (DMSO) and conditioned medium for neuron induction, respectively, to differentiate into neuron-like cells. The expression of nestin, neuron-specific enolase (NSE) and neurofilament (NF) on the treated cells were detected by immunocytochemical method.

RESULTS

Nestin expression were found in 6.7% of the primary, 12.4% of the second passage, 20.8% of the fifth passage of MSCs, respectively. Thirty-six percent of cell cultures treated with the conditioned medium for neuron induction were immunoreactive for NSE and NF, and 33% of the cells induced by beta-ME and 25% of the cells by DMSO also expressed NSE and NF.

CONCLUSION

Cord blood MSCs possess some features of neural stem cells, and have the capacity to differentiate into neuron-like cells under proper conditions.

[A probability analysis for HLA matching in adult stem cell transplantation treating nervous genetic diseases]

The aim of this study was to investigate the clinical feasibility of adult stem cell transplantation for lethal mono-gene inherited disease, Duchenne muscular dystrophy (DMD). A total of 30 blood samples from DMD patients were genotyped with HLA-A,-B and -DR alleles by means of polymerase chain reaction-reverse sequence specific oligonucleotide (PCR-RSSO). The HLA gene types in 30 DMD patients were compared with those of 668 unrelated donors from Umbilical Cord Blood Center of Guangdong Province and 34 910 unrelated donors from Chinese Bone Marrow Bank. The results showed that HLA gene of the DMD group was inherited in normal distribution. There was no striking difference of HLA-A, -B and -DR alleles expression between the DMD patients group and control healthy group. 25% of the DMD patients got suitable donors for stem cell transplantation, in which 15 patients found donors with >or= 5/6 HLA match at the Umbilical Cord Blood Center of Guangdong Province, i.e. occupying 50% of the total. Eight patients got 6/6 HLA matching donors at the Chinese Bone Marrow Bank, i.e. occupying 26% of the total. It is concluded that stem cells transplantation therapy for DMD patients is feasible, which will benefit these patients suffered from the lethal neuromuscular disease, and create a new way to treat this tough nervous system disease.

[Progress on the study of HLA-Cw--review]

HLA-Cw belongs to classic HLA-I gene, HLA-Cw molecules have high polymorphism like HLA-A and B molecules. They distribute extensively on the surfaces of karyote, not only presenting endogenetic antigen to CD8+ T cells to induce specific killing effect, but also participating in immunologic reaction as the ligands of killer cell immunoglobulin-like receptor (KIR). Thus it has been valued for their relations to diseases and the functions in transplantation immunity, anti virus and anti-tumor immunity.

[Treatment of malignant hematologic diseases by peripheral blood stem cell transplantation combined with halotype lymphocyte infusion]

In order to observe the curative and side effects in malignant hematologic diseases treated with autologous peripheral blood stem cell transplantation (auto-PBSCT) combined with halotype lymphocyte infusion, auto-PBSCs were mobilized, harvested and stored at -196 degrees C from patients in first CR or PR with intensive chemotherapy (Ara-C 1.0 g/m(2) x 5 days or cyclophosphamide 60 mg/kg x 2 days) and G-CSF. Unpurged auto-PBSCs were infused when patients received the conditioning regimen with busulfan, total irradiation or cyclophosphamide. Halotype lymphocytes [mean 5.0 x 10(7)/kg, (4.5 - 6.5) x 10(7)/kg] irradiated with 7.5 Gy were infused to patients when WBCs were more than 1 x 10(9)/L. Hematopoietic recovery and survival of patients were observed. The results showed that in 12 cases accepted this protocol, five patients with acute non-lymphocytic leukemia got to durable remission, of which 2 had durable remission of more than 50 months. One of three patients with non-Hodgkin's lymphoma IVb reached durable remission, and two relapsed and died on 4 and 6 months after treatment, respectively. Two CML patients were also achieved durable remission. One patient with multiple myeloma relapsed on 36 months later, but he still survived disease-free with treatment of thalidomide. In a follow-up survey of 25 months, the disease-free survival was 83%. No severe side effects were observed except platelet delayed recovery after halotype lymphocyte infusion. STR-PCR analysis showed that infused donor lymphocytes disappeared in 3 recipients at 72 hours after infusion. It is concluded that auto-PBSCT combined with halotype lymphocyte infusion could decrease the relapse of malignant hematologic diseases and improve the effect of auto-PBSCT. Recovery of platelet, however, could be delayed by halotype lymphocyte infusion.

[The application of molecular biology techniques in HLA-typing]

Human leukocyte antigen (HLA) is an important immunogenetic system. It plays a key role in immunoresponsiveness and hematopoietic stem cell and organ transplantation. The development of modern medicine and tissue typing promotes the combination of molecular biology techniques with HLA typing, and improves the accuracy and practicability of HLA typing. In this review, recent advances were concisely introduced in research of HLA typing on the application of restriction fragment length polymorphism (RFLP), sequence specific oligonucleotide probe (SSOP), single strand conformational polymorphism (SSCP), sequence specific primer (SSP), flow cytometry, gene chip, sequencing based typing, virtual DNA analysis and so on.

[Panel reactive antibody screening and human leukocyte antigen typing in 1 700 cases of renal transplantation]

OBJECTIVE

To evaluate the role of panel reactive antibody (PRA) screening and human leukocyte antigen (HLA) typing in renal transplantation.

METHODS

PRA screening and HLA typing were performed in 1 700 patients eligible for the first group of renal transplantation who had 3 to 6 HLA matches in HLA-A, B and DR with the donor, and in cases positive for PRA, plasma exchange was conducted. Another 423 patients who did not receive PRA screening or HLA typing constituted the second group. The changes of immune variables, incidences of acute rejection and the effect of HLA-A, B, DR matching on long-term graft survival were observed.

RESULTS

In 1 700 cases of group 1, post-transplantation CsA dose was reduced to 5 to 7 mg*kg(-1)*d(-1) and the graft function recovery time ranged from 2 to 16 d, averaging 5 d. Acute graft rejection occurred in 252 (14.8%) cases, but no hyper-acute rejection was observed. The 1-, 3- and 5-year patient/graft survival rates were 98.6%/96.7%, 93.1%/87.3% and 88.1%/83.6% respectively. In group 2, CsA dose ranged from 8 to 12 mg*kg(-1)*d(-1) and the graft function recovery time was 4 to 30 d, averaging 13 d. Hyper-acute rejection occurred in 9 (2.1%) and acute rejection in 198 (46.8%) cases, and the 1-, 3- and 5-year patient/graft survival rates were 86.7%/76.3%, 72.5%/67.9% and 69.5%/59.3% respectively.

CONCLUSIONS

Negative PRA and good HLA matching can eliminate the incidences of hyper-acute rejection, decrease the rate of acute rejection and improve both patient and graft survival rates.