Objective To explore the association of catechol-O-methyhransferase(COMT) gene polymorphisms with schizophrenia susceptibility and its symptoms assessed by Positive and Negative Syndrome Scale (PANSS)in southern Chinese population.Methods COMT gene rs4633,rs4680 and rs8185002 polymorphisms were genotyped using Sequenom genotyping technology in 700 schizophrenia patients (300 Zhuang and 400 Han) and 700 healthy controls (300 Zhuang and 400 Han),and Positive and Negative Syndrome Scale (PANSS) was used for clinical symptoms assessment of patients.Statistical analysis was performed using PLINK software.Results rs4633,rs4680 and rs8185002 polymorphisms were not significantly associated with schizophrenia susceptibility in Zhuang or Han population respectively(P＞0.05).After merging Zhuang and Han samples,rs4633(I 2 =0.000,Pmeta =0.040) and rs4680 (I2=0.000,Pmeta =0.014) were significantly associated with the susceptibility to schizophrenia.In addition,haplotype T-A-T was significantly associated with schizophrenia susceptibility (P=0.049).However,these three polymorphisms were not significantly associated with total score,positive scale score,negative scale score and general psychopathology scale score assessed by PANSS(P＞0.05).Conclusion COMT gene rs4633 and rs4680 polymorphisms are involved in the susceptibility to schizophrenia in southern Chinese population.

Background and purpose: Diffusion-weighted whole-body imaging with background body signal suppression (DWIBS) can be used for magnetic resonance imaging systemic examination, especially in examing the metastatic lesions, lymph node and bone diseases, and the imaging result is similar with PET. This study aimed to evaluate the application value of magnetic resonance DWIBS and positron emission tomography with computed tomography (PET/CT) on malignant metastatic diseases. Methods: Thirty-six patients confirmed with malignant tumors accompanying metastasis by the pathology of operation or biopsy underwent both DWIBS imaging and PET/CT, chi-square test and Kappa test were used for comparing the detection results of metastasis by these 2 imaging methods. Results:Among the 36 malignant tumor patients with 238 metastatic lesions, 218 (91.6%, 218/238) lesions in DWIBS and 209 (87.8%, 209/238) lesions in PET/CT were detected, with 200 lesions detected by the two methods simultaneously, and the concordance rate was 88.7%(211/238);but there was no statistical signiifcance between this two methods (χ2=1.843, P=0.157). Kappa test showed a fair concordance rate between DWIBS and PET/CT (P=0.000).There were different significance between DWIBS and PET/CT in detecting metastatic lesions of brain and bone (P=0.005 and 0.031);But there was no signiifcant differences (P=0.309 and 1.000) in detecting metastatic lesions of lymph nodes and liver. Conclusion:DWIBS could detect metastatic lesions effectively, and there is ifne consistency with PET/CT. DWIBS is more sensitive than PET/CT in detecting metastatic lesions of brain and bone, so DWIBS could be chosed for screening metastatic lesions according to the characteristics of different primary tumors.

Objective To evaluate the bone healing effect of vascularized tissue-engineered bone induced by endothelial progenitor cells(EPCs)in repair of large segmental radius defects in rabbits.Methods A total of 68 healthy New Zealand white rabbits were enrolled in the study and randomized into three groups,ie,experimental group(EPCs group):EPCs plus bone marrow mesenchymal stem cells (BMSCs)plus decalcified bone matrix(DBM);control group:BMSCs plus DBM;sham control group:pure DBM.Materials mentioned above were implanted into middle radius defects for 15 mm.At 12 and 16 weeks post-operatively,X-ray test,bone mineral density test,histological light microscopic test,osteocalcin immunohistochemical staining test and biomechanical test were carried out.Results Growth and plasticity of callus,speed of medullary cavity recanalization,bone healing speed and biomechanical intensity in the experimental group were all significantly better than those of control group.Conclusions Vascularized tissue-engineered bone induced by EPCs has strong osteegenic ability,can accelerate bone healing and hence is an effective method for repair of large segmental bone defects.

A droplet digital polymerase chain reaction ( ddPCR) method for quantifying E. coli O157:H7 by targeting rfbE gene was developed. The probe concentration in ddPCR was optimized and the linearity range, precision, limit of detection ( LOD) and limit of quantification ( LOQ) were also evaluated. The optimized probe concentration was 300 nmol/L. The ddPCR response was linear over the E. coli O157:H7 genome DNA concentration range from 4 to 1. 25×105 copies in 20 μL ddPCR system and the linear correlation coefficient (R2) was 0. 999. The ddPCR precision (RSD) was less than 5% over the DNA concentration range from 760 to 88400 copies/20 μL. The LOD and LOQ was 3 copies in 20 μL and 4 copies in 20 μL, respectively. Specificity test showed that the ddPCR was specific for detecting E. coli O157:H7. Both ddPCR and standard real time quantitative PCR showed the same results for 16 real samples of chicken meat, pork and beef, which indicated that ddPCR method was suitable for detection of E. coli O157:H7 in food.

Background and purpose:Diffusion-weighted whole-body imaging with background body signal suppression (DWIBS) can be used for MR imaging systemic examination, especially the lymph node and bone diseases can be clear, and the imaging result is similar with PET. The aim of this study was to compare the value of clinical application in the diagnosis of malignant metastatic osteopathic between DWIBS and bone scintigraphy mapping. Methods:Thirty-six specimens conifrmed with malignant tumors by the pathology of operation or biopsy underwent both DWIBS imaging and bone scintigraphy mapping, chi-square test was used for comparing the detection results of bone metastasis by this two imaging methods. Results:Thirty (165 positions in all) of 36 malignant tumor patients were conifrmed as having bone metastasis, compared that 26 patients (143 positions) with DWIBS method and 23 patients (132 positions) with bone scintigraphy mapping were detected, but there was no statistical signiifcance between this two imaging methods (χ2=1.002, P=0.506). The sensitivity, positive predictive value (PPV) and accuracy of the detection rate of bone metastasis were similar in DWIBS and bone scintigraphy, with 86.7%, 96.3%, 86.1%and 76.7%, 88.5%, 72.2%, respectively;but the speciifcity and negative predictive value (NPV) in DWIBS (83.3%and 55.6%) was higher than that of in bone scintigraphy (50.0%and 30.0%). The detection rates of different bone metastasis with DWIBS and bone scintigraphy were 86.7%(143/165) and 80.0%(132/165), and it was no signiifcant difference (χ2=2.640, P=0.104);DWIBS method was better than bone scintigraphy in the detection of osseous metastasis on pelvis and limbs long bone, and there was different signiifcant (χ2=6.783 and 7.636, P=0.023 and 0.016). Conclusion:DWIBS could detect bone metastatic lesions effectively, and there is ifne consistency with bone scintigraphy. Therefore, DWIBS is to hope to be extended and applicated clinically.

Objective To investigate the epidemic of severe acute respiratory symdrome(SARS) in Beijing blood donors and make guidance for assuring blood safety during SARS epidemic.Methods Using SARSCoV Ab ELISA Kits, specimens from 2357 donors from Beijing during SARS epidemic phase,1079 preserved samples from Beijing donors collected well before the SARS epidemic,1183 donors from Shandong and Hunan provinces where no SARS had been reported were screed for IgG,IgM,and total antibodies against SARS coronavirus.Donors with reactive samples were followed up,RT PCR were performed to detect the SARS CoV RNA.Results There was no significant difference between the 3 groups of specimens and there was no SARS epidemic or subclinical SARS infections among Beijing blood donors.Conclusion Instead of blood SARS CoV Ab screening, we should focus on the donors inquiry,physical examination and education to prevent SARS transmission by transfusion.

OBJECTIVE: To explore the effect of vinyl chloride on the blood sex hormones and liver function of male workers. METHODS: A total of 129 male vinyl chloride workers(exposure group) and 128 male office workers who were not exposed to occupational hazards(control group) were selected as study subjects by judgment sampling method. The time weighted average concentration(C_(TWA)) of vinyl chloride in the workplace air was measured. The level of urine thiodiglycolic acid(TDGA), blood routine, electrocardiogram and liver B-ultrasound were performed on the subjects. The serum levels of liver function and sex hormones were measured. RESULTS: The median of C_(TWA) of vinyl chloride in the workplace was 0.90 mg/m~3, and the geometric mean was 1.40 mg/m~3. The level of urine TDGA in the exposed group was higher than that of the control group(median: 0.68 vs 0.02 mg/g Cr, P<0.01). The abnormal rate of hemoglobin level, erythrocyte count, leukocyte count, hematocrit, mean platelet volume, aspartate transaminase, total bilirubin, indirect bilirubin and liver B-ultrasound increased in the exposure group than that of the control group(P<0.05). The levels of serum prolactin, leuteinizing hormone(LH), follicle-stimulating hormone and estradiol in the exposure group increased, the abnormal rates of prolactin, LH and estradiol increased, and the level of testosterone decreased compared with the control group(P<0.05). The levels of prolactin in the low-, medium-and high-TDGA subgroups in the exposure group increased(P<0.05), and the abnormal rates increased compared with the control group(P<0.017). CONCLUSION: Vinyl chloride can cause liver function damage in male workers and have reproductive toxicity. Prolactin can be used as a biomarker of reproductive toxicity of vinyl chloride.

Objective:To investigate the effect of tissue engineered bladder patch constructed by double-layer silk scaffold and adipose-derived stem cells (ADSCs) in the repair and reconstruction of bladder.Methods:This study was conducted from May 2020 to March 2021. The silk fibroin (SF) aqueous solution was obtained from silkworm cocoons, and a double-layer silk scaffold composed of silk fibroin film and silk fibroin sponge was further prepared. The rat ADSCs were isolated, cultured, and the ADSCs surface markers (CD29, CD90, CD45, CD106) were identified by flow cytometry. The ADSCs were planted on a double-layer silk scaffold to construct a tissue-engineered bladder patch. Thirty-six male SD rats were randomly divided into three groups: tissue engineered bladder patch group (SF-ADSCs group, n=15), double-layer silk scaffold group (SF group, n=15), control group ( n=6). The tissue engineered bladder patch (SF-ADSCs group) and double-layer silk scaffold (SF group) were wrapped on the omentum to promote vascularization. The vascularization was evaluated by HE and immunofluorescence staining. The wrapped tissue engineered bladder patch and double-layer silk scaffold were used to repair the defective bladder. In the control group (six rats), the incision was closed immediately after the bladder tissue fully exposed. At 4 weeks and 12 weeks after operation, the general morphology of bladder tissue and cystography were performed to evaluate the recovery of bladder morphology. After the graft was harvested, HE and Masson's trichrome staining and immunofluorescence staining were used to observe the regeneration of bladder wall tissue. Urodynamics was used to assess the recovery of bladder function at 12 weeks after operation. Results:The flow cytometry results confirmed that the isolated cells positively expressed CD29 and CD90, and there was no significant expression of CD45 and CD106. Gross observation and scanning electron microscope confirmed that the preparation of double-layer silk scaffold not only had a pore structure that was conducive to cell planting, but also had good toughness and was facilitated to surgical suture. The number (43.50±2.66) and area (0.73±0.03)% of vascular-like structures in the SF-ADSCs group after the omentum encapsulation was significantly higher than that in the SF group [(24.50±3.51), (0.55±0.05)%], and the difference was statistically significant ( P<0.05). At 4 weeks after bladder repair, the histological staining of the grafts in the SF-ADSCs and SF groups showed a large number of degraded fragments of double-layer silk scaffold. At 12 weeks, the morphology of the graft in the SF-ADSCs group showed uniform bladder morphology, which was similar to that of normal bladder tissue. Immunofluorescence staining showed that the continuous urothelial layer, abundant smooth muscle tissue, vascular structure and regenerated neurons could be observed in the SF-ADSCs group. Urodynamic test showed that the bladder maximum volume (0.74±0.03)ml and compliance (16.68±0.44)μl/cm H 2O in the SF-ADSCs group, which were better than that in the SF group [(0.47±0.05)ml, (14.89±0.37)μl/cm H 2O], but lower than that in the control group [(1.12±0.08)ml, (19.34±0.45)μl/cm H 2O], and the difference was statistically significant ( P<0.05). Conclusions:The tissue engineered bladder patch constructed with double-layer silk scaffolds and ADSCs could promote the morphological repair of bladder tissue, the regeneration of bladder wall structure and the recovery of bladder physiological function.

Objective:To prepare the whole bladder acellular matrix (BAM) using the self-designed perfusion decellularization system, and evaluate the feasibility of constructing the tissue engineering bladder with the adipose-derived stem cells (ADSCs).Methods:This study was conducted from October 2020 to April 2021. The self-designed perfusion decellularization system was used, and four different decellularization protocols (group A, group B, group C and group D) were formulated, according to the flow direction of the perfusate and the action time of different decellularization solutions. Among them, the urethral orifice of the bladder tissue was used as the outflow tract of the perfusion fluid in groups A and B. The top of the bladder was cut off and used as the outflow tract of the perfusion fluid in groups C and D. In groups A and C, 1% Triton X-100 was treated for 6 h, and 1% sodium dodecyl sulfate (SDS) was treated for 2 h. In groups B and D, 1% Triton X-100 was treated for 7 h, and 1% sodium dodecyl sulfate (SDS) was treated for 1 h. In addition, the tissue in the normal bladder group was directly obtained from the natural bladder tissue, which did not require perfusion, cryopreservation and thawing. The fast and efficient decellularization protocol was screened out through HE, DAPI, Masson trichrome and Alcian Blue staining and quantitative analyses to prepare the whole bladder scaffold. The prepared BAM was used as the scaffold material, and the ADSCs were used as the seeding cells to construct the tissue engineering bladder. HE and DAPI staining were used to observe the distribution of ADSCs on the BAM.Results:HE and DAPI staining showed that there was no obvious nuclear residue in the group C. Masson trichrome and Alcian Blue staining showed that the collagen structure and glycosaminoglycan were well preserved in the group C. There was no significant difference in bladder wall thickness between the group C and the normal bladder group [(975.44±158.62)μm vs.(1 064.49±168.52)μm, P > 0.05]. The DNA content in the group C [(43.59 ±4.59) ng/mg] was lower than that in the normal bladder group, group A, group B and group D [(532.50±26.69), (135.17±6.99), (182.49±13.69) and(84.00±4.38)ng/mg], and the difference was statistically significant ( P<0.05). The collagen content [(10.98 ± 0.29)μg/mg] and glycosaminoglycan content [(2.30±0.18)μg/mg] in group C were not significantly different with those in the normal bladder group [(11.69±0.49) and (2.36±0.09)μg/mg, P>0.05]. Scanning electron microscopy showed that a large number of pore structures could be observed on the surface of the prepared BAM in groups A-D and were facilitated to cell adhesion. The isolated and cultured ADSCs were identified by flow cytometry to confirm the positive expression of CD90 and CD29, and the negative expression of CD45 and CD106. Live/dead staining and CCK-8 detection confirmed that the prepared BAM in the group C had no cytotoxicity. HE and DAPI staining showed that a large number of ADSCs were distributed on the surface and inside of the tissue engineering bladder. Conclusions:The whole bladder shape BAM prepared by the self-designed perfusion decellularization system could be used as the scaffold material for bladder tissue engineering, and the constructed tissue engineering bladder could be used for bladder repair and reconstruction.

Objective:This study aimed to investigate the physical properties, biocompatibility, and 3D printing performance of a novel hybrid bioink composed of gelatin methacrylated (GelMA) and chitin nanocrystal (ChiNC).Methods:The study was conducted from May 2021 to December 2022, four different bioinks were prepared by adding varying amounts of ChiNC to GelMA bioink. The GelMA concentration in all four bioinks was 100 mg/ml, while the ChiNC concentrations were 0 mg/ml (no ChiNC added), 5 mg/ml, 10 mg/ml, and 20 mg/ml, respectively, named as GC0, GC5, GC10, and GC20 bioinks. The cross-sectional morphology of the hydrogels formed after photocuring the four bioinks was observed using scanning electron microscopy, and the porosity was calculated. Weighing the hydrogels before and after swelling, and then calculate the equilibrium swelling rate. HUVECs were seeded on the surfaces of the hydrogels prepared from the four bioinks and cultured in medium. Cell proliferation was assessed using CCK-8 assays at 1d, 3d, and 7d to compare the proliferation rates of cells on the four hydrogels. HUVECs were added to the four bioinks, and grid-like scaffolds were printed and cultured in medium. Live-Dead staining was performed at 1d and 7d to observe cell viability. Compare the printing effect of bioinks by observing its forming continuous threads properties during extrusion. Finally, tissue-engineered bladder patches simulating the mucosal layer, submucosal layer, and muscular layer anatomical structures of the bladder wall were 3D bioprinted using the optimized bioink composition, and the stability and fidelity of the printed structures were observed to further validate the feasibility of printing multi-layered complex structures with the bioink.Results:Scanning electron microscopy revealed that the porosity of the GC0, GC5, GC10, and GC20 hydrogels were (51.43±6.23)%, (51.85±6.47)%, (50.55±4.59)%, and (42.49±2.20)%, respectively. The differences in porosity between the GC0 group and the other three groups were not statistically significant ( P=0.9994, P=0.9948, P=0.1200). The equilibrium swelling ratio of the other three groups [(8.81±0.41), (7.95±0.19), (7.71±0.14)] was significantly lower than that of the GC0 group (9.37 ± 0.49), and the differences were statistically significant ( P=0.0457, P<0.01, P<0.01). CCK-8 assay showed no significant difference in absorbance value between the GC10 group (0.360±0.009) and the GC0 group (0.357±0.007), GC5 group (0.350±0.012), and GC20 group (0.345±0.018) on the first day ( P=0.9332, P=0.5464, P=0.4937). However, on the third day, the absorbance value of the GC10 group (0.755±0.012) was significantly higher than that of the GC0 group (0.634±0.010), GC5 group (0.704±0.009), and GC20 group (0.653±0.015) ( P<0.01, P=0.0033, P=0.0002). On the seventh day, the absorbance value of the GC10 group (1.001±0.031) was significantly higher than that of the GC0 group (0.846±0.026), GC5 group (0.930±0.043), and GC20 group (0.841±0.024)( P=0.0012, P=0.1390, P=0.0010). The addition of human umbilical vein endothelial cells (HUVECs) into the four groups of hydrogels enabled the printing of grid-like scaffolds, and Live-Dead staining was performed on day 1 and day 7. The cell viability of HUVECs in the four groups on day 1 was (90.13±1.63)%, (90.6±2.45)%, (92.58±2.15)%, and (91.40±3.17)%, respectively. There were no statistically significant differences between the GC0 group and the other three groups ( P=0.9869, P=0.3093, P=0.8008). On day 7, the cell viability was (89.97±3.10)%, (92.18±2.21)%, (92.05±2.25)%, and (90.12±1.97)% for the four groups, respectively. There were no statistically significant differences between the GC0 group and the other three groups ( P=0.3965, P=0.4511, P=0.9995). Bioink extrusion test showed that the GC0 hydrogel could be extruded continuously and form threads at temperatures between 24℃ and 25℃, while the GC10 hydrogel could be extruded continuously and form threads at temperatures between 24℃ and 27℃. Printing tissue engineered bladder patches simulating the anatomical structure of the bladder mucosal layer, submucosal layer, and muscular layer using GC10 bioink, and the printed patches were stable, without collapse, and had high fidelity. Conclusions:Adding ChiNC to GelMA promotes cell adhesion, proliferation, and expands the printing window of GelMA bioink. The biocompatibility of the mixed bioink prepared by adding 10 mg/ml ChiNC in GelMA is good, capable of printing tissue-engineered bladder patches that mimic the anatomical structure of natural bladder walls.