[Changes in OCTA-related parameters and their impact on retinal sensitivity after ILM flap inversion surgery in patients with IMH].

Objective: To analyze the changes in optical coherence tomography angiography(OCTA)-related parameters before and after idiopathic macular hole (IMH) internal limiting membrane (ILM) flap inversion surgery and assess their impact on retinal sensitivity. Methods: A retrospective case series study was conducted, collecting clinical data of 30 patients (30 eyes) diagnosed with IMH who underwent vitrectomy combined with ILM flap inversion surgery at Shanxi Eye Hospital, affiliated with Shanxi Medical University, between January 2020 and December 2021. Visual acuity and best-corrected visual acuity were examined preoperatively and at 1, 3, and 6 months postoperatively. Microperimetry measured retinal sensitivity (RS), and OCTA measured retinal thickness (RT) as well as vessel density (VD) in the superficial capillary plexus (SCP) and deep capillary plexus (DCP). Statistical analysis was performed using t-tests, repeated measures analysis of variance, and Pearson correlation analysis. Results: Thirty patients with IMH (30 eyes) were included, with 3 males (3 eyes) and 27 females (27 eyes). The mean age was (62.5±3.0) years, and the follow-up time was (96.3±1.3) days, with a 100% closure rate of macular holes postoperatively. RT in the macular was significantly lower at 1, 3, and 6 months postoperatively compared to preoperative values (F=46.21, P<0.001). The RT in the upper macular region showed statistically significant differences at different time points (P<0.001). VD in the SCP layer showed no significant differences between the upper and lower macular regions at various time points (F=3.21, P=0.601). VD in the upper region of the DCP layer increased at 1, 3, and 6 months postoperatively (P<0.001). RS in the macular was higher at 1, 3, and 6 months postoperatively compared to preoperative values (F=52.01, P<0.001). RS in the lower macular region increased at 3 and 6 months postoperatively (P<0.001), while in the upper region, it increased only at 6 months postoperatively (P<0.001). There was a positive correlation between RS and RT at 1 and 3 months postoperatively, but not at 6 months postoperatively in the upper macular region (r=0.40, P=0.071). In the lower macular region, there was a positive correlation between RS and RT at 1 and 3 months postoperatively (P<0.001). There was no correlation between RS in the upper macular region at 6 months postoperatively and preoperative RT (r=0.43, P=0.072), but there was a positive correlation with RT at 3 months postoperatively (r=0.58, P=0.041). Conclusions: After idiopathic macular hole internal limiting membrane flap inversion surgery, the OCTA-related parameters have changed. There are transient changes in deep vascular parameters and thinning of the retinal layers at the ILM inversion site, leading to decreased sensitivity.

[A case-control study on the relationship between DNA methylation and occupational noise hearing loss].

Objective: To explore the relationship between DNA methylation and occupational noise-induced hearing loss. Methods: A case-control study was conducted. People with hearing loss induced by occupational noise were recruited as the case group and those with normal hearing but still exposed to occupational noise were recruited as the control group. A total of 60 participants were included, of which 30 participants were in the case group and 30 in the control group. The methylation level was detected by 850k genome-wide DNA methylation chip technology. The significance of differential methylated position (DMP) was tested by R-packet 'Champ'. The differential methylated region (DMR) was analyzed by using Champ's Bumphunter algorithm. Cluster profiler was used to analyze the gene list for GO and KEGG pathway enrichment. Results: There was significant difference between two groups in binaural high-frequency average hearing threshold (P<0.05), but there was no significant difference in age, smoking, drinking, hypertension, physical exercise and cumulative noise exposure. The results of DMP and DMR analysis showed that 713875 sites were detected in the case group and the control group, and 439 methylation sites with significant difference, accounting for 0.06%; 650 regions were detected, and 72 methylation regions with significant differences, accounting for 11.08%. Compared with the control group, the results of GO enrichment analysis showed that the case group had statistically significant differences in four pathways: axogenesis of projection neurons in the central nervous system, neuronal development in the central nervous system, axogenesis of neurons in the central nervous system and neuronal differentiation in the central nervous system. KEGG enrichment analysis showed that there were significant differences in sphingolipid metabolism, aldosterone synthesis and secretion, primary bile acid biosynthesis pathway between the case group and the control group. Conclusion: The occurrence of occupational noise-induced hearing loss may be related to the regulation of gene expression related to axogenesis of projection neurons in the central nervous system, development of neurons in the central nervous system, axogenesis of neurons in the central nervous system, differentiation of neurons in the central nervous system, sphingolipid metabolism, aldosterone synthesis and secretion, primary bile acid biosynthesis and gene methylation related to metabolism.

[Analysis of the level of T lymphocyte subsets and the relationship with the prognosis of pulmonary fibrosis in patients with paraquat poisoning].

Objective: To analyze the levels of T lymphocyte subsets (CD3, CD4, CD8 and CD4/CD8) in patients with paraquat poisoning, and to explore the relationship between the changes of T lymphocyte subsets and the prognosis of pulmonary fibrosis. Methods: In October 2019, a total of 47 patients with oral 20% paraquat low water solvent poisoning in Guangzhou 12th people's Hospital from June 2018 to June 2019 were selected as the research objects. Patients were divided into early death group (16 cases died within 2 weeks) and non early death group (31 cases survived more than 2 weeks) . The non early death group was divided into pulmonary fibrosis group (23 cases) and normal lung group (8 cases) . 20 healthy people in the same period were randomly selected as the control group. The neutrophils (N) , C reaction protein (CRP) , alanine aminotransferase (ALT) , creatinine (Cr) , amylase (aAMY) , creatine kinase isoenzyme (CKMB) , pH, HCO(3)(-), blood oxygen saturation (SO(2)) and lactic acid (Lac) of patients poisoned within 3 d were examined every day. Independent sample t-test was used for inter group comparison, and paired sample t-test was used for intra group comparison. Results: Compared with non early death group, the levels of N, CRP, ALT, Cr, aAMY, CKMB and Lac in early death group increased (P<0.05) , while pH and HCO(3)(-) decreased (P<0.05) . Compared with the control group, the levels of CD3, CD4 and CD4/CD8 were decreased on the first day in the early death group and non early death group (P<0.05) , and the levels of CD3, CD4 and CD4/CD8 were decreased on the 15th day in the pulmonary fibrosis group (P<0.05) . Compared with the normal lung group, the levels of CD3, CD4 and CD4/CD8 in the pulmonary fibrosis group decreased on the 15th day (P<0.05) . Conclusion: The persistent low cellular immune function in patients with paraquat poisoning is related to the progress of pulmonary fibrosis, which is an important factor affecting the prognosis of patients with pulmonary fibrosis.

[The humor characteristics of young epileptic patients and its correlation with depression].

Objective: To explore the characteristics of humor in young adult epileptic patients and examine the relationship between humor and depression. Methods: We recruited 55 young adult epileptic patients who visited outpatient clinic of the Department of Neurology of Yijishan Hospital of Wannan Medical College between October 2018 and March 2019 and 44 healthy controls to complete the multidimensional humor scale (MSHS), humor style questionnaire (HSQ) and Beck depression scale-Ⅱ (BDI-Ⅱ), and compared their differences between the two groups. Results: The results showed that the young adult patients with epilepsy (PWEs) were affected in humor creation, coping with humor and the totally scores of MSHS. The scores of humor creation, coping with humor and the totally scores of MSHS in the young epilepsy patients were 25.3±5.9, 16.7±5.0 and 61±10, which were significantly lower than those in the control group 29.8±6.1, 21.1±2.6 and 71±8. As for the humor style, self-defeating humor scores in PWEs were higher than controls 14±5 vs 9±3, and the self-enhancing humor scores were lower than controls 18±7 vs 23±6. The scores of BDI-Ⅱ in PWEs were significantly higher than those of normal controls 13±7 vs 6±4. Pearson's correlation test showed that the scores of BDI-Ⅱ were negatively correlated with humor creation, coping with humor, the totally scores of MSHS and self-enhancing humor scores (r=-0.566--0.721, P<0.05), while it was positively correlated with self-defeating humor scores (r=0.818, P<0.05). Among the clinically relevant factors, the scores of BDI-Ⅱ were correlated with seizure control and gender. Multiple stepwise linear regression showed that coping with humor, self-defeating and self-enhancing humor scores were closely related with depression in young epileptic adults. Conclusion: The young adults with epilepsy are affected in sense of humor and humor style, which are closely related with depression.

[ABO gene subtypes and gene expression analysis in three cases of hematological malignancies patients].

Objective: To explore the application and discovery of genotyping, gene sequencing, and gene expression analysis in the determination of ABO blood group subtypes and antigen expression abnormalities in hematological malignancies patients. Methods: From June 2019 to May 2020, three clinical cases were found with forward and reverse ABO typing discrepancy or atypical serologic agglutination pattern in the laboratory and blood transfusion department of Hebei Yanda Ludaopei Hospital were selected. Sequence-specific primer PCR (PCR-SSP) and Sanger sequencing of ABO gene coding regions were performed to determine the ABO genotypes, and whole transcriptome sequencing was used to analyze ABO and FUT1 gene expression levels. Results: A 12-year-old female acute lymphoblastic leukemia patient was determined as O.01.02 and BA.04 sub-genotype, corresponding to the serological B(A) subtype, and her ABO gene expression was normal (354.80). A 41-year-old female acute myeloid leukemia patient was determined as A1.02 and B.01 genotype, corresponding to the serological A(1)B phenotype, and her ABO gene expression was significantly reduced (45.70). A 42-year-old male with myelodysplastic syndrome and myelofibrosis was determined as A1.02 and A2.05 sub-genotype, corresponding to the serological A(1) and A(2) phenotype, respectively, and his ABO expression was negative. FUT1 expression was in the normal range in all three cases. The clinical blood product infusion strategy was formulated according to the genotype and the corresponding immunological subtype, and no significant transfusion-related adverse reactions occurred. Conclusion: Blood group sub-genotypes or aberrant gene expression can lead to ambiguities in serological blood group determination in hematological malignancies patients. ABO genotyping and gene expression analysis can help in this scenario and escort blood product infusion safety.

[The impact of KIT and other concomitant gene mutations on the prognoses of patients with core-binding factor acute myeloid leukemia].

Objective: To study the impact of KIT and other concomitant gene mutations on the prognoses of patients with core-binding factor acute myeloid leukemia (CBF-AML). Methods: A total of 104 newly diagnosed patients with CBF-AML in Hebei Yanda Lu Daopei Hospital from January 2014 to February 2018 were analyzed, and high-throughput gene sequencing for the detection of mutations among 58 genes was executed. Also, the clinical features of KIT mutation-positive CBF-AML (KIT+CBF-AML) patients and the effects of other concomitant gene mutations on the prognoses of patients were also analyzed. Results: A total of 56 cases (53.85%) with KIT mutations were found in 104 CBF-AML patients. Among this, KIT D816 mutation was the most common (32 patients), followed by the N822 mutation (17 patients). Patients with KIT+CBF-AML have a higher proportion of bone marrow blasts at the time of diagnoses and are more likely to have sex chromosome loss. Among the 52 patients with KIT+CBF-AML who were followed up, the allogeneic hematopoietic stem cell transplantation (allo-HSCT) group had a higher overall survival rate (OS) than that of the chemotherapy group (88.9% vs 57.1%, χ(2)=6.076, P<0.05). The event-free survival (EFS) and OS of patients with KIT+CBF-AML with FLT3 mutation were both significantly lower than those of the FLT3 mutation-negative group (EFS: 40.0% vs 72.3%, χ(2)=6.557, P<0.05; OS: 60.0% vs 87.2%, χ(2)=8.305, P<0.05). The OS of the patient with TET2 mutation was lower than that of the TET2 mutation-negative group (50.0% vs 87.5%, χ(2)=4.130, P<0.05). Conclusion: Patients with KIT+CBF-AML with concomitant gene mutations, especially FLT3 and TET2, have poor prognoses, which can be improved by allo-HSCT.

[Association between GSTP1 gene polymorphisms and susceptibility to noise-induced hearing loss].

Objective: To investigate the association between the single nucleotide polymorphisms (SNPS) at rs1695 and rs6591256 in glutathione S-transferase P1 (GSTP1) gene and susceptibility to noise-induced hearing loss in Chinese Han workers exposed to noise. Methods: Using the 1: 1 nested case-control study and taking 6297 workers exposed to noise in a steel plant in Henan province as the cohort study population in July 2019, we screened those who have been exposed to noise for ≥3 years and whose binaural high frequency (3000, 4000, 6000 Hz) average hearing threshold is ≥40 dB (A) into the case group. The control group was selected according to the matching criteria of the same sex, same type of work, and the age difference was not more than 5 years old, and the working age difference was not more than 2 years. 276 subjects were selected into the case group and the control group respectively. The medium and high throughout single nucleotide polymorphism typing technology (SNPscanTM technology) was used to detect the polymorphism of three nucleotide sites of GSR gene, and conditional logistic regression was used to analyze the relationship between single nucleotide polymorphism (SNP) and NIHL, and the relationship between different polymorphic sites and the risk of NIHL after adjusting covariates. After stratification with different cumulative noise exposure (CNE) , Conditional logistic regression analysis was used to analysis the risk of NIHL at different loci. Results: The mean and standard deviation of age of the selected subjects was (40.28±8.00) , the mean and standard deviation of noise-exposed working years was (18.7±8.92) years. The range of noise exposure levels and comulative noise exposure were 80.05-93.35dB (A) and 86.83-107.92 dB (A) ·year, respectively. Compared with the control group, there were no statistically significant differences in age, noise-exposured working years, intensity of noise exposure, CNE, gender, drinking, hypertension prevalence and noise exposure level in the hearing loss group (P>0.05) , while there were statistically difference in smoking, binaural high-frequency average hearing threshold and binaural speech frequency (P<0.05) . After adjusting for smoking, drinking, hypertension and other factors, in the co-dominant model, compared with GGgenotype, the risk of NIHL was higher in rs1002149 GT genotype and rs2251780 GA genotype (OR=1.558, 95%CI: 1.028-2.361; OR=1.550, 95%CI: 1.020-2.355, P<0.05) ; compared with TT/GT genotype, the rs1002149 TT genotype has a higher risk of developing NIHL (OR=1.494, 95%CI: 1.002-2.228, P<0.05) , while rs3779647 genotype had no relationship with the risk of NIHL (P>0.05) . In the equivalent sound level (L(Aeq)) of noise >85 dB (A) stratification, compared with GG genotype, carrying rs1002149 GT genotype and rs2251780 GT genotype has higher risk of nihl (OR=1.801, 95%CI: 1.093-2.967; OR=1.720, 95%CI: 1.050-2.817, P<0.05) . Haplotype analysis of two sites, rs1002149 and rs2251780, was not found to be related to NIIHL susceptibility. Conclusion: The allele G of rs1695 and rs6591256 may be risk factors of NIHL.

[Genetic characteristics and clinical outcomes of pediatric acute myeloid leukemia with NUP98-NSD1 fusion gene].

Objective: To investigate the genetic characteristics and clinical outcomes of pediatric acute myeloid leukemia patients with NUP98-NSD1 fusion gene. Methods: A total of 80 pediatric AML patients were enrolled in this study, and bone marrow specimens were collected at initial diagnosis and relapse. NUP98-NSD1 was screened by fluorescence in situ hybridization (FISH) and PCR. Other laboratory test results and clinical outcomes were further analyzed for the NUP98-NSD1 positive cases. Results: A total of eight patients (10.0%) were positive for NUP98-NSD1, which were all fusions of NUP98 exon12 and NSD1 exon 6. There were two M2, three M4, and three M5 cases according to the French-American-British classification. Seven patients had karyotype results at the time of initial diagnosis, and none of them had complicated karyotype abnormalities. Among these patients, two cases had normal karyotype, three cases had trisomy 8, one case had trisomy 6, and two cases had anomalies involving 9q13 or 9q21. Additional karyotypic abnormalities and clonal evolutions were observed during disease progression or relapse, five cases had 9q13 or 9q32 abnormalities. Five cases (62.5%) were positive with FLT3-ITD mutation. Patients were treated with DAE/NAE/HAE/IA chemotherapy. Three cases did not achieve remission after several courses of chemotherapy, and five cases achieved remission but relapsed in 1 to 19 months. Five cases underwent salvage allogeneic hematopoietic stem cell transplantation (allo-HSCT). Among whom, four died in 40 days to 4 months after transplantation, and one survived 8.5 months till the last follow-up. Conclusions: NUP98-NSD1 is a recurrent genetic abnormality with significant clinical prognostic significance, and this group of disease has unique clinical and genetic characteristics. NUP98-NSD1 should be screened by FISH or PCR for children with AML who are newly diagnosed or refractory and relapsed to identify the high-risk genetic marker.

Parathyroid hormone (1-34) promotes fracture healing in ovariectomized rats with type 2 diabetes mellitus.

Ovariectomized (OVX) rats with type 2 diabetes mellitus (T2DM) with femur fracture received vehicle, insulin, or insulin plus parathyroid hormone (PTH) treatment for 2 and 3 weeks. Radiography, histomorphometry, histology, and immunohistochemistry in callus were evaluated. INTRODUCTION: Reports about effects of PTH plus insulin on callus formation of osteoporotic fracture with T2DM were limited. This study was designed to investigate the effects of the combination of PTH and insulin on fracture healing in OVX rats with T2DM. METHODS: Two-month-old female rats were randomly divided into five groups: normal fracture (F), OVX fracture (OF), T2DM + OVX fracture (DOF), insulin-treated (2-4 u/daylight, 4-6 u/night, DOFI), and treated with insulin and PTH (50 µg/kg/day, 5 days/week, DOFIP). A closed mid-shaft fracture was established in the right femurs of all rats after 6 weeks of OVX. Rats were euthanized at 2 and 3 weeks post-fracture according to the time schedule, respectively. RESULTS: The administration of insulin alone or insulin combined with PTH significantly increased mineralized bone volume fraction (BV/TV) and connectivity density (Conn.D) compared with those of the DOF group at 3 weeks post-fracture and also increased cartilaginous callus area ratio in the DOFI and DOFIP groups at 2 weeks and bony callus area ratio in the DOFIP groups at both the 2 and 3 weeks post-fracture. CONCLUSIONS: OVX rats with T2DM exhibited a marked delay in the fracture healing process; insulin treatment ameliorated these effects, and the healing process was enhanced following treatment with a combination of insulin and PTH.

[Effects of unsafe sexual behavior and sexual orientation on previous HIV testing and HIV testing willingness among college students in Harbin].

Objective: To analyze the effects of unsafe sexual behavior and sexual orientation on previous HIV testing and HIV testing willingness among college students in Harbin, to provide a theoretical basis for promoting and promoting HIV testing among them. Methods: A cross-sectional survey design was used to place the automatic vending machine of HIV urine test kit in 9 universities in Harbin from December 2017 to January 2018. The questionnaire star was used to design and recruit college students to carry out an anonymous online survey. The estimated sample size was 6 659. A multivariate logistic regression model was used to analyze the effects of unsafe sexual behavior and sexual orientation on previous HIV testing and HIV testing willingness among college students. WPS 2016 was used to sort out the database, and SPSS 21.0 software was used for statistical analysis. Results: A total of 60 849 valid questionnaires were collected. 19.1% (11 189/58 605) of college students reported having sex. College students who used condoms correctly every time, occasionally or never during sex in the past six months 58.5% (6 206/10 603), 25.2%(2 669/10 603)and 16.3% (1 728/10 603), respectively. Heterosexuality, homosexuality and bisexuality accounted for 94.1% (54 393/57 823), 2.4% (1 369/57 823) and 3.5% (2 061/57 823), respectively. The HIV testing willingness of college students was 73.3% (44 572/60 849). The proportion of previous HIV testing was 10.3% (951/9 241). Results of the multivariate logistic analysis showed that compared with the college students who used condoms correctly whenever they had sex in the past six months, there was no significant difference in the proportion of previous HIV testing among college students who sometimes/occasionally used or never used condoms (OR=0.94,95%CI:0.69-1.29; OR=1.11,95%CI:0.73-1.67), but their willingness to HIV testing was lower (OR=0.79, 95%CI:0.71-0.89; OR=0.48, 95%CI:0.42-0.55); Compared with heterosexual college students, homosexual or bisexual college students have a higher proportion of previous HIV testing (OR=2.62, 95%CI:1.62-4.24; OR=2.04, 95%CI:1.25-3.32), but have lower HIV testing willingness (OR=0.76, 95%CI: 0.62-0.93; OR=0.64, 95%CI: 0.53-0.77). Conclusions: Unsafe sexual behavior existed among college students in Harbin, and college students with weak awareness of HIV prevention also have weak awareness of testing. Behavioral intervention should be strengthened and HIV testing promoted. Compared with heterosexuals, homosexual or bisexual college students had a higher proportion of previous HIV testing, but their willingness to test was lower. The HIV detection mode with better concealment, accuracy, and convenience should be promoted on the college's campus.

[Influencing factors and their predictive value of skin graft survival after Meek grafting in severe burn patients].

Objective: To investigate the influencing factors and their predictive value of skin graft survival after Meek grafting in severe burn patients. Methods: A retrospective case-control study was conducted in 115 severe burn patients (95 males, 20 females, aged 1-74 years) who met the inclusion criteria and received Meek grafting in the First Affiliated Hospital of Army Medical University (the Third Military Medical University) from January 2013 to December 2019. The patients were divided into good skin graft survival group with skin graft survival rate≥70% (68 cases) and poor skin graft survival group with skin graft survival rate<70% (47 cases). The statistics of patients in the two groups were recorded during their first Meek grafting after admission including the gender, age, body mass index, full-thickness burn area, burn index, complication of inhalation injury, time from injury to operation, preoperative cystatin C level, preoperative albumin level, preoperative neutrophil, preoperative hemoglobin level, preoperative platelet count, and platelet count on the first, third, and fifth day after operation. The above indicators were statistically analyzed between the two groups with independent sample t test, Mann-Whitney U test, and chi-square test. A 1∶1 propensity score matching (PSM) of the gender, age, body mass index, full-thickness burn area, burn index, complication of inhalation injury, time from injury to operation of patients in the two groups were performed to eliminate the differences in baseline data, and then the above indicators of the remaining patients in the two groups were recorded and analyzed again. The indicators with statistically significant differences between the two groups after 1∶1 PSM were selected for multivariate logistic regression analysis to screen the independent risk factors affecting the skin graft survival after Meek grafting in severe burn patients. The receiver operating characteristic (ROC) curve of independent risk factors for predicting poor skin graft survival after Meek grafting in severe burn patients after 1∶1 PSM was drawn, and the area under the curve, the cut-off value, and the sensitivity and specificity under the cut-off value were calculated. The patients after 1∶1 PSM were divided into independent risk factor>the cut-off value group and independent risk factor≤the cut-off value group with the incidence of poor skin graft survival after Meek grafting compared using the chi-square test, and the relative risk of poor skin graft survival after Meek grafting was calculated. Results: Before 1∶1 PSM, there were no statistically significant differences in gender, age, body mass index, complication of inhalation injury, time from injury to operation, preoperative cystatin C level, preoperative albumin level, preoperative neutrophil, preoperative hemoglobin level of patients between the two groups (P>0.05); the full-thickness burn area and burn index of patients in poor skin graft survival group were significantly higher than those in good skin graft survival group (Z=-2.672, -2.882, P<0.01); the preoperative platelet count and the platelet count on the first, third, and fifth day after operation of patients in poor skin graft survival group were significantly lower than those in good skin graft survival group (Z=-3.411, -3.050, -2.748, -2.686, P<0.01). After 1∶1 PSM, 46 cases were remained in each group. There were no statistically significant differences in gender, age, body mass index, full-thickness burn area, burn index, complication of inhalation injury, time from injury to operation, preoperative cystatin C level, preoperative albumin level, preoperative neutrophil, preoperative hemoglobin level of remaining patients between the two groups (P>0.05); the preoperative platelet count and the platelet count on the first, third, and fifth day after operation of patients in poor skin graft survival group were significantly lower than those in good skin graft survival group (Z=-3.428, -2.940, t=-2.427, -2.316, P<0.05 or P<0.01). Multivariate logistic regression analysis showed that the preoperative platelet count was the only independent risk factor affecting the skin graft survival after Meek grafting in severe burn patients (odds ratio=0.994, 95% confidence interval=0.989-0.998, P<0.01). The area under the ROC curve of preoperative platelet count predicting poor skin graft survival after Meek grafting in 92 patients was 0.707 (95% confidence interval=0.603-0.798, P<0.01), and the cut-off value of preoperative platelet count was 98×109/L, with sensitivity of 54.3% and specificity of 78.3% under the cut-off value. The incidence of poor skin survival after Meek grafting of patients in preoperative platelet count≤98×109/L group was 71.4% (25/35), which was obviously higher than 36.8% (21/57) in preoperative platelet count>98×109/L group (χ2=10.376, P<0.01). Compared with that in preoperative platelet count>98×109/L group, patients in preoperative platelet count≤98×109/L group had a relative risk of poor skin graft survival after Meek grafting of 2.211 (95% confidence interval=1.263-3.870). Conclusions: Preoperative platelet count is an independent risk factor affecting the skin graft survival after Meek grafting in severe burn patients and has a good predictive value. Meek grafting should be performed with caution when the preoperative platelet count of patients is≤98×109/L.