BACKGROUND:Carboxymethyl chitosan (CMCS),a chitin derivative,has a good application performance that makes it become a safe and effective hemostatic material.OBJECTIVE:To determine the hemostatic effect of CMCS and its biosecurity properties.METHODS:(1) CMCS powder was scattered on the caudal vein and liver wounds of Sprague-Dawley rats,and the hemostatic time was recorded as experimental group,while the time for natural haemostasis of the wound was recorded as control group.(2) CMCS powder was scattered on the tail,femoral artery and liver wounds of ICR mice,and the hemostatic time was recorded as experimental group,while the time for natural haemostasis of the wound was recorded as control group.(3) CMCS,Sodium dodecyl sulfate solution and distilled water were respectively applied on the skin of albino rabbits in a skin irritation test.(4) A delayed-type hypersensitivity test of CMCS was carried out by intradermal injection of CMCS in guinea pigs.(5) An intradermal irritation test was carried out by subcutaneous injection of normal saline containing CMCS and normal saline,respectively.Another intradermal irritation test was carried out by subcutaneous injection of the supernatant of CMCS olive oil extract and olive oil,respectively.RESULTS AND CONCLUSION:(1) Compared with the control group,the hemostatic time for caudal vein and liver wounds were significantly shortened in the Sprague-Dawley rats in the experimental group (P ＜ 0.01).(2) Compared with the control group,the time of hemostasis on the tail,femoral artery and liver wounds was significantly shortened in the ICR mice in the experimental group (P ＜ 0.05 or P ＜ 0.01).(3) The CMCS had no irritation to the skin of albino rabbits and no allergic reaction to the skin of guinea pigs.To conclude,the CMCS has good hemostatic effect on the wound in Sprague-Dawley rats and ICR mice,and has no skin irritation,allergic reactions and intradermal irritation reactions in albino rabbits and guinea pigs,which is a relatively safe hemostatic material.

Objective To observe the bacteriostatic effect of chitosan lactate with different relative molecular masses in vitro. Methods The MICs of the chitosans lactate with different relative molecular masses against the usual pathogens were detected,and the MBCS against two standard strains were also determined. Levofloxacin hydrochloride was used as a control drug. Results The MIC90 of chitosan lactate with 10,30,50kDa against 50 strains of gram-positive cocci and 50 strains of gram-negative bacilli were 0.5,1~4,0.5~4mg?mL-1 and 1~4,0.5~1 ,0.5~4mg?mL-1,respectively. The MIC90 of levofloxacin hydrochloride against the 50 strains of gram-positive cocci and 50 strains of gram-negative bacilli were 4～8 and 8～16?g?mL-1,respectively. ATCC 25923 strain of S.aureus and ATCC 25922 strain of E.coli could be killed by 10kDa chitosan lactate in the concentration of 4mg?mL-1. The MBCS of levofloxacin hydrochloride against ATCC25923 strain of S.aureus and ATCC 25922 strain of E.coli were 2 and 4?g?mL-1,respectively. Conclusion The 4 species of the experimental bacteria could be inhibited by the chitosan lactate with 10,30 and 50kDa Mr in vitro,but the inhibitory effect of the chitosan lactate with 10kDa Mr was stronger among them. ATCC 25923 strain of S.aureus and ATCC25923 strain of E.coli could be killed only by 10kDa chitosan lactate in vitro,not by others.

Aim To observe the effect of oxysophori-dine( OSR) on the EEG changes and its power spectrums of cerebral frontal cortex in anaesthetized rats. Methods With the equipment of brain stereotactic apparatus,electrode was implanted into frontal lobe of cerebral cortex in rats. Unipolar lead and computerized FFT technique were employed to record the index of EEG,power spectrum and frequency distributions to analyze the effect of OSR on the bioelectricity altera-tions of frontal lobe in cerebral cortexi in rats. Results Administrated( icv) with OSR at the dose of 2. 5,5, 10 mg/rat in rats,the EEG of frontal lobe of cerebral cortex was mainly featured by low amplitude and slow waves accompanied by spindle-formed sleeping waves with a significant decrease of total power of EEG( P

BACKGROUND:WIF-1 is a tumor suppressor gene. Promoter hypermethylation causes WIF-1 down-regulationin most tumors. DNA methylation inhibitor can lead to gene demethylation and restore its expression. OBJECTIVE:To observe the differences of tumor pathology and, WIF-1 mRNAand proteinchanges using WIF-1 or 5-aza-2'-deoxycytidine demethylation in animalmodels of osteosarcoma.
METHODS:Murine osteosarcoma models were established and divided into three groups. In the control group, no treatment was given. In the 5-aza-2'-deoxycytidine group, an appropriate amount of 5-aza-2'-deoxycytidine was injected ineach mouse daily. In the WIF-1 group, an appropriate amount of Wnt/β-catenin signal transduction pathway inhibitor WIF-1 was injected in each mouse daily. Seven days after medication, the weight of nude mouse was weighed every 7 days. Short tumor diameter (a) and the long diameter (b) were measured. Therelative tumor volume was calculated. The relative growth rate of tumor was calculated at 7, 14, 21, 28 and 56 days. Four nude mice from ach group were sacrificed by puling the neck at 7, 14, 21, 28 and 56 days after medication. Tumor tissues were stripped and the weight of them was weighed. Pathological analysis of the tumor was conducted. The expression of WIF-1protein and WIF-1 mRNA was detected in osteosarcoma at 56 days after medication in the three groups.
RESULTS AND CONCLUSION:(1) Compared withthe medication and control groups, the weight of nude mice was increased at 7, 14, 21, 28 and 56 days in the treatment group. No significant difference was found between the medication and control groups. (2) The tumor size was significantly smaler in themedication group than in the control group. WIF-1 mRNA and WIF-1 protein expression was increased in the medication group compared with the control group to different degrees. (3) Results suggested that WIF-1 gene promoter methylation is one of the mechanisms of the development of osteosarcoma. Use of WIF-1 or 5-aza-2'-deoxycytidine demethylation can inhibit tumor growth in animal models of osteosarcoma.

0.05),however,it can shorten curative time obviously on Ⅱ type dental ulcer.Simultaneously,the general reaction and focal mucosa of borneolum and borax pellicle group had no obvious variation before and after the test.Conclusions Chitosan has no effect on min-pigs' nerve,cardiovascular and respiratory system;and it is relatively safe given by mouth or peritoneal injection.The borneolum and borax pellicle can shorten curative time obviously on Ⅱtype dental ulcer.

ObjectiveTo identify mutations ofGATA4 andGATA6 genes in children with isolated congenital atrial septal defect (ASD).Methods From November 2012 to November 2013, 101 patients with ASD (99 unrelated patients and one twin) who were submitted to catheter-based intervention and 100 ethnicity-matched children without congenital heart disease, blood disorders and chromosomal abnormalities were enrolled. The blood was collected. The coding regions and lfanking regions of theGATA4 andGATA6 genes were ampliifed by polymerase chain reaction and sequenced using the dideoxvnucleotide chain termination technique, and then compared with the normal sequence in the Genbank.Results Two novel heterozygous missense GATA6mutations, c. G145A and c. G151A, were identiifed in 2 unrelated ASD patients, which were not present in the controls. These two mutations predicted the conversion of glycine into serine at amino acid residue 49 (G49S) and glutamate into lysine at amino acid residue 52 (K52E). A heterozygous missenseGATA6 mutation c.43 G>C, which caused a conversion from glycine to arginine, was found in 9 ASD patients and 7 controls. A single nucleotide polymorphism c.99G>T, which did not cause amino acid conversion inGATA4 gene, was found.ConclusionsGATA6 gene is an important transcription factor in heart development. The mutation ofGATA6 gene may cause the change of its transcriptional activity, and lead to ASD.

GATA6 transcription factor belongs to the GATA family and contains 2 conserved zinc ifnger DNA binding domains. GATA6 not only presents in embryonic tissues but also found in heart, lung and pancreas and is essential for the maintenance of their function.The present review focuses on the critical roles of GATA6 in heart development and atrial septal defect to provide theoretical basis for diagnosis and treatment of atrial septal defect.

Objective:To compare the detection rate of genital Chlamydia trachomatis (CT) DNA between urine and urethral/cervical swab samples. Methods:From December 2018 to December 2019, a total of 1 475 outpatients were collected from sexually transmitted disease clinics in 7 medical institutions, such as Department of Venereology, Guangzhou Institute of Dermatology, including 1 118 males and 357 females. One urethral/cervical swab sample and one urine sample were collected successively from each patient. Real-time fluorescence-based PCR was performed to detect CT DNA in urine and urethral/cervical swab samples, and paired chi-square test was used to compare the positive rate of CT DNA between the 2 kinds of samples. Random- or fixed-effect meta-analysis was conducted for the test of heterogeneity and merging of positive rates of CT DNA in the urine and urethral/cervical swabs among 7 medical institutions.Results:The positive rate of CT DNA in the urine samples was significantly higher than that in the swab samples from 4 medical institutions (all P < 0.05) , while there was no significant difference in the positive rate of CT DNA between the 2 kinds of samples from 3 medical institutions (all P > 0.05) . The heterogeneity ( I2) estimates of the CT-DNA positive rate in urine and swab samples among different medical institutions were 78.6% (95% CI: 55.9% - 89.6%) and 73.7% (95% CI: 43.7% - 87.7%) , respectively; meta-analysis showed that the total merged positive rate of CT DNA in the urine samples was 10.8% (95% CI: 7.2% - 15.9%) , which was significantly higher than that in the swab samples (7.8%, 95% CI: 4.9% - 12.1%; χ2 = 39.2, P < 0.05) . Compared with the swab sample-based CT-DNA detection method, the sensitivity, specificity, positive predictive value, negative predictive value and consistency rate of the urine sample-based CT-DNA detection method were 97.0% (128/132) , 96.3% (1 293/1 343) , 71.9% (128/178) , 99.7% (1 293/1 297) , and 96.3% (1 421/1 475) , respectively. The positive rate of CT DNA in the urine samples from 1 118 male patients was 11.0% (95% CI: 7.2% - 16.5%) , which was significantly higher than that in the swab samples (7.6%, 95% CI: 4.9% - 11.8%; χ2 = 34.3, P < 0.05) . There was no significant difference in the positive rate of CT DNA between the urine (11.9%, 95% CI: 7.7% - 17.9%) and cervical swab samples from 357 female patients (10.4%, 95% CI: 7.6% - 14.0%; χ2 = 3.2, P > 0.05) . Conclusions:The positive rate of CT DNA in urine samples is higher than or similar to that in urethral/cervical swab samples. The urine sample-based CT-DNA detection method has characteristics of convenience, non-invasiveness, painlessness and low cost, and is worthy of clinical promotion.

Objective:To investigate the feasibility and clinical efficacy of posterior vertebral column resection (PVCR) combined with polymethylmethacrylate-augmented pedicle screw instrumentation and shortening of spinal column for stage Ⅲ Kümmell's disease with very severe collapse of fractured vertebra.Methods:From January 2017 to September 2021, 9 patients with stage Ⅲ Kümmell's disease with very severe collapse of fractured vertebra underwent PVCR combined with polymethylmethacrylate-augmented pedicle screw instrumentation and shortening of spinal column. Their medical records were retrospectively analyzed. There were 1 male and 8 females, aged (66.9±5.8) years. The injured vertebra was located at T 11 in 2 patients, at T 12 in 4, at L 1 in 2 and at L 2 in 1. X-ray, CT and MRI were performed before operation. The posterior intervertebral heights of adjacent vertebral bodies of the fractured vertebra in the median sagittal position were measured on CT or MRI to evaluate the shortening of the spinal column before PVCR. Recorded were intraoperative bleeding volume, operation time, complications, bone graft fusion, and American Spinal Injury Association (ASIA) grading at preoperation and the last follow-up. The visual analogue scale (VAS) pain scores, Oswestry disability index (ODI) scores, and kyphotic cobb angles at preoperation, 1 week and 3 months postoperation, and the last follow-up were compared to evaluate the clinical efficacy of PVCR. Results:All patients underwent surgery successfully, with tight closure of adjacent vertebrae after resection of the injured vertebra and bone grafting. Operation time was (240.6±23.2) min and intraoperative bleeding (505.6±95.0) mL. The 9 patients were followed up for (17.3±5.6) months. No worsening symptoms of nerve injury, cerebrospinal fluid leakage, or other serious complications were found after operation, nor such complications as loosening or breakage of internal fixation or adjacent vertebral fractures. Bone fusion was achieved at the bone graft sites in all patients by the last follow-up. The VAS and ODI scores and cobb angles at 1 week and 3 months postoperation and at the last follow-up were significantly decreased compared with preoperation ( P<0.05). There were no significant differences in VAS scores or cobb angles among postoperative 1 week and 3 months and the last follow-up ( P>0.05), but pairwise comparisons between different time points after operation showed significant differences in ODI, with postoperative 1 week > postoperative 3 months > the last follow-up ( P<0.05). The ASIA grading at the last follow-up was improved from preoperative grade C to grade D in 2 cases, from preoperative grade C to grade E in 1 case and from preoperative grade D to grade E in 5 cases. Conclusion:PVCR combined with polymethylmethacrylate-augmented pedicle screw instrumentation and shortening of spinal column is a feasible and effective surgical treatment for stage Ⅲ Kümmell's disease with very severe collapse of fractured vertebra, leading to good clinical efficacy.

【Objective】 To analyze the cost and effectiveness of different HIV screening strategies based on multi-center HIV residual risk study, so as to provide reference for blood centers to adopt appropriate HIV testing strategies. 【Methods】 According to the HIV screening and confirmation of blood donors in three blood centers in Anhui Province, the residual risk of different HIV screening strategies was estimated. A decision tree model was established to analyze the cost-effectiveness differences of three different screening strategies under current domestic policies. 【Results】 The residual risk of anti-HIV-1 +2 ELISA, HIV Ag/Ab1+2 ELISA and ELISA+NAT were 1.17×10^-6,0.84×10^-6 and 0.59×10^-6, respectively. According to decision tree model analysis, HIV Ag/Ab1+2 ELISA had a cost-effectiveness advantage over anti-HIV 1+2 ELISA when there was no NAT, but the advantage of HIV Ag/Ab1+2 ELISA disappeared when there was one NAT. The cost of HIV reagents, the cost of HIV treatment and the cost of false positive discarding were sensitive factors of the model. 【Conclusion】 In this area, one anti-HIV 1+2 ELISA combined with one NAT has a cost-effectiveness advantage. Blood centers need to confirm and evaluate the ELISA reagents used before conducting HIV screening. Under the premise of ensuring sensitivity, reagent cost and reagent false positive rate are the key factors.