[Clinical analysis of gene mutation characteristics and mutation burden in myelodysplastic syndrome].

Objective: To investigate the relationship between gene mutation characteristics, mutation burden and general condition, disease subtype and karyotype of patients with myelodysplastic syndrome (MDS), and its clinical value. Methods: High-throughput sequencing was used to detect 65 blood tumor-related genes in 191 MDS patients and 9 secondary acute myelocytic leukemia patitents(SAML), and to analyze the characteristics of abnormal genes, mutation burden, as well as the relationship with disease subtypes, chromosome karyotypes and age. Results: Mutations were found in 148 patients (77.5%), including 47 abnormal genes and 186 mutation sites. And gene mutations were found in 9 SAML patients, the number of mutations was significantly higher than that in MDS patients (χ(2)=11.911, P=0.018). Among the abnormal genes, the mutation frequency of U2AF1 (37.3%) and ASXL1 (41.6%) were higher, and there were significant differences in mutation burden among different abnormal genes (F=91.946, P<0.001). There were differences in the number of gene mutations among different subtypes of MDS, and the number of EB-2 gene mutations was the highest (2.2±1.5). In SLD, MLD, EB-1 and EB-2, the proportion of carrying ≥ 3 mutations increased gradually (χ(2)=52.471, P=0.037). TP53 mutation was associated with abnormal karyotype (r(φ)=0.177, P=0.019), especially with complex karyotype (r(φ)=0.440, P<0.001), while NPM1 mutation is associated with normal karyotype (r(φ)=0.173, P=0.024). The number of mutations carried by patients under 30 years old was the least, and the number of mutations increased with the increase of age. The number of mutations was the most in patients aged 60 to 79 years old (P=0.017), and the mutation frequency of epigenetic related genes increased with the increase of age (P=0.041). Conclusions: The mutation characteristics and mutation load of MDS-related genes are closely related to clinical factors such as disease subtype, chromosome karyotype and patient age.

[The genetic characteristics of BCR-ABL-negative myeloproliferative neoplasms].

Objective: To explore the relationship between driver gene mutation (JAK2, MPL and CALR) and disease type in BCR-ABL negative myeloproliferative neoplasms (MPNs) including primary myeloid fibrosis (PMF), essential thrombocytosis (ET) and polycythemia vera (PV). Methods: A total of 32 MPN related genes were detected by high-throughput sequencing in 156 MPN patients. The relationships between disease type and patients' general performance, the characteristics of driver gene mutations, concomitant gene mutations were analyzed. Results: In the population with JAK2 V617F positive mutation, the proportion of patients over 60 years old in PMF was higher than that with ET or PV. By high-throughput sequencing, 22 concomitant gene mutations were detected in 46 patients with JAK2, MPL or CALR mutations, including 4 (8.3%) in PV, 20 (29.4%) in ET, and 22 (55.0%) in PMF. DNMT3A mutation was detected only in patients with PV, while splicing factor related genes including SF3B1, SRSF2 and U2AF1 were only accompanied by PMF. According to the variation allele frequency (VAF) value of JAK2 V617F mutation, the VAF value associated with PV was the highest (68.15%), followed by PMF (37.7%) and ET (23%). However, there were significant differences in the incidence of JAK2 V617F homozygous among 3 different diseases. In patients with JAK2 mutation, the proportion of other gene mutations in PV and ET was significantly lower than that in PMF. Conclusions: Under the condition of common driver gene mutations (JAK2, MPL and CALR), patients' age, VAF value and homozygous state, concomitant gene mutations are closely related to different disease type. These correlations help to improve clinical understanding of disease characteristics and risk assessment.

Genetic diversity of Y-short tandem repeats in Chinese native cattle breeds.

The aim of this study is to use Y-chromosome gene polymorphism method to investigate regional differences in genetic variation and population evolution history of the Chinese native cattle breeds. Six Y-chromosome short tandem repeat (Y-STR) loci (UMN0929, UMN0108, UMN0920, INRA124, UMN2404, and UMN0103) were analyzed using 1016 healthy and heterogenetic males and 90 females of 9 native cattle breeds (Qinchuan, Jinnan, Zaosheng, Luxi, Nanyang, Jiaxian, Dabieshan, Yanbian, and Menggu) in China. Allele frequency and gene diversity were calculated for the various populations. The results indicated that Y-STRs in the 6 loci have polymorphisms and genetic diversity in Chinese cattle populations. The genetic diversity analysis revealed that the Chinese cattle populations have a close genetic relationship. The analysis of INRA124, UMN2404, and UMN0103 loci revealed the original history of Chinese cattle because of which cattle belonging to Bos taurus or Bos indicus could be determined. Interestingly, a declining zebu introgression was displayed from South to North and from East to West in the Chinese geographical distribution, which implied that cattle population from various regions of China had been subjected to somewhat different evolutionary history. This conclusion supported other evidences such as earlier archaeological, historical research, and blood protein polymorphism analysis.

Association between a single nucleotide polymorphism in the bovine chemerin gene and carcass traits in Qinchuan cattle.

Qinchuan is a red or yellow draft and beef breed in China. In order to identify a predictor of carcass traits on the basis of associations between carcass traits and gene polymorphism, variation in the bovine chemerin gene was investigated using PCR-single-strand conformational polymorphism and DNA sequencing. An SNP of A868G located in exon 2 of the Bos taurus chemerin gene was detected in 716 samples of six breeds (Jiaxian red, Luxi, Nan yang, Qinchuan, Simmental and Luxi crossbred steers, and Xia'nan), all in China, and three genotypes (AA, AG and GG) were found. Based on the χ(2) test, the AA/AG/GG genotype frequencies of all six breeds were found to be in Hardy-Weinberg equilibrium. A possible association of A868G with some carcass traits was investigated in 106 Qinchuan cattle. Animals with the AG genotype were found to have significantly lower mean loin eye area and meat tenderness compared to those with the AA and GG genotypes. However, there was no significant association between any individual haplotype and backfat thickness, water holding capacity or marbling score. We suggest that A868G could be used as a molecular marker in marker-assisted selection for carcass traits.

Molecular cloning, characterization and association analysis of the promoter region of the bovine CDK6 gene.

Cyclin-dependent kinase 6 (CDK6) is a key element of D-type cyclin holoenzymes. It is involved in the regulation of the G1-phase of the cell cycle and is considered to be an important candidate gene for selection of body measurement traits through marker-assisted selection. We cloned the promoter sequence of this gene in bovines and found it to share high similarity with that of the human CDK6 promoter. A 2271-bp sequence upstream of the start codon in the bovine CDK6 5'-flanking sequence is rich in GC; it lacks consensus TATA or CAAT box, but it contains several MZF1 binding sites. Other potential cis-regulatory elements were found in the 5'-flanking region, including CdxA, SRY, p300, GATA-1, and deltaE. Allele frequencies were also analyzed in various cattle breeds (Qinchuan, Qinchuan improvement steers, Nanyang, Jiaxian red, Xia'nan, Luxi, Simmental and Luxi crossbred steers, and Xuelong) and association with a selected single nucleotide polymorphism (SNP) was calculated. The T-1075C SNP in the promoter was found to be significantly associated with body length and heart girth. This SNP marker was found to be significantly associated with body length and the heart girth in 737 individuals. We conclude that this SNP of the CDK6 gene has potential as a genetic marker for important body traits in bovine reproduction and breeding.

Polymorphism of bovine Y-STR UMN0929 and its correlation with carcass traits in five Chinese beef cattle populations.

The correlations between Y chromosome polymorphisms and the carcass traits were studied in five Chinese beef cattle populations by PCR, single strand conformation polymorphism and Y-STR sequence analysis. Nine alleles and their frequencies were identified on Y-STR UMN0929 region in Qinchuan (n=116), Luxi (n=112), Jinnan (n=104) pure breeds, Simmental×Qinchuan crossbred (n=80) and Angus×Qinchuan crossbred (n=96). The most popular A-176 and B-178 alleles were presented in all 5 cattle populations in the range of 12% (Jinnan) to 66% (Simmental×Qinchuan). The allele I-194 presented Luxi and Angus×Qinchuan. In Qinchun cattle, G-190 and E-186 alleles had bigger effect on BPI (4.23±0.32 and 4.22±0.48 kg/cm, P<0.01) and CW (325.40±49.42 and 316.73±45.29 kg, P<0.01), respectively. In Luxi cattle, I-194 allele affected higher BPI (4.08±0.35 kg/cm, P<0.01) and CW (302.07±17.55 kg, P<0.01), respectively. In Jinnan cattle breed, H-192 had higher BPI (4.32±0.50 kg/cm, P<0.05) and CW (327.87±59.37 kg, P<0.05), respectively. In Simmental×Qinchuan cross breed, C-180 allele affected largely on BPI (5.16±0.25 kg/cm, P<0.05) and CW (393.16±25.92 kg, P<0.05). In Angus×Qinchuan cross breed, I-194 had higher BPI (4.43±0.33 kg, P<0.05) and CW (346.63±29.77 kg, P<0.05). Correlations between alleles and other carcass traits (net meat weight, top grade weight, slaughter rate, net meat rate, loin-eye muscle area, carcass length, meet tenderness and shear force) were also analyzed using mixed-effect model. Cattle Y-STR UMN0929 loci alleles and its correlation with carcass traits in beef cattle populations could be implemented into the cattle breeding program for choosing beef cattle with better carcass traits.

The cryoprotective effects of vitamin B12 supplementation on bovine semen quality.

The present study aimed to investigate the effects of vitamin B(12) supplementation on standard bovine semen quality parameters and anti-oxidative enzyme activities. Vitamin B(12) was supplemented at concentrations of 1.25, 2.5, 3.75 and 5.0 mg/ml to bovine semen cryoprotective medium. The results indicated that the motility and straight line velocity, curvilinear velocity, mean coefficient, velocity of the average path values of sperm supplemented with 2.50 mg/ml vitamin B(12) were significantly higher than that of other groups (p<0.05). No significant difference was observed for linearity index, lateral head displacement values and the percentage of grade A spermatozoa between the extenders containing 2.50 and 3.75 mg/ml vitamin B(12) (p>0.05). The percentages of acrosome-intact and plasma membrane-intact spermatozoa were significantly improved (p<0.05) by supplementing with 2.50 mg/ml vitamin B(12) . The results of biochemical assay revealed that vitamin B(12) supplementation did not cause significant changes in superoxide dismutase levels compared with control (p>0.05). However, the catalase levels were higher in the treatment supplemented with vitamin B(12) at 2.50 mg/ml, when compared with other groups (p<0.05). The extender supplemented with vitamin B(12) significantly decreased glutathione peroxidase activity compared with the control (p<0.05). The supplementation of 3.75 mg/ml vitamin B(12) caused the highest value of glutathione reductase activity, compared with other groups (p<0.05). In conclusion, the extender supplemented with vitamin B(12) could reduce the oxidative stress provoked by freezing-thawing and improve bovine semen quality. Further studies are required to obtain more concrete results on the determination of lipid peroxidation and antioxidant capacities of vitamin B(12) in cryopreserved bovine semen.

The effects of different immunosuppressants on chronic allograft nephropathy by affecting the transforming growth factor-beta and Smads signal pathways.

OBJECTIVE: This study investigated the effects of various immunosuppressants on chronic allograft nephropathy (CAN) by affecting transforming growth factor-beta (TGF-beta) and Smads signal pathway. METHODS: Vascular smooth muscle cells (VMSC) from rat aorta were incubated for 6 or 12 hours with various immunosuppressants. Cyclosporine (CsA) (3 microg/mL), FK506 (1 microg/mL), mycophenolate mofetil (MMF) (0.3 microg/mL), rapamycine (Rapa) (10 microg/mL), CsA (1 microg/mL/MMF 0.3 microg/mL). We used the Sprague-Dawley Wistar rat accelerated kidney sclerosis model. Before transplantation, the kidney was preserved 1 hour in 0 degrees C to 4 degrees C heparin sodium chloride solution to reinforce the cold ischemia injury. The rats were divided into eight groups (each group n = 8): group A, pseudo-OP; group B, isotransplantation; group C, CsA 6 mg/kg . d; group D, FK506 0.15 mg/kg . d; group E, MMF 20 mg/kg . d; group F, Rapa 0.8 mg/kg. d; group G, CsA 3 mg/kg . d + MMF 20 mg/kg . d. The serum creatinine levels and pathological changes, according to the Banff scheme, were observed at 2, 4, 6, 8 and 12 weeks posttransplantation. Immunohistochemistry and quantitative fluorescence polymerase chain reactions were used to end localize and quantitate the expression of TGF-beta1 and Smad 2, 3, 7 in VMSC and in the transplanted kidney. RESULTS: CsA and FK506 stimulated gene expression and protein production of TGF-beta1, smad2, and smad3, but inhibited expression of smad7 both in VSMC and in the transplanted kidney. In contrast, MMF and Rapa down-regulated gene expression and protein production of TGF-beta1, smad2, 3 while up-regulating expression of smad7. There was no significant difference between the CsA group and the FK506 group, as well as the MMF group and the Rapa group. The group treated with CsA + MMF was similar to the MMF and the Rapa groups. CONCLUSION: Our study suggested that various immunosuppressants affected differentially TGF-beta1 and Smads signal pathways in rat VSMC and kidney grafts. CsA and FK506 can cause CAN, owing to up-regulated expression of smad2 and smad3, and down-regulation of smad7 expression. MMF and Rapa can prevent the CAN progression, because of down-regulation of the expression of smad2 and smad3, with increased smad7 production.

Radical resection of the shoulder girdle for a malignant tumor: four case reports.

Four cases of malignant tumor of the shoulder were treated by radical resection of the shoulder girdle, saving the upper extremity. During follow up, all patients were able to use their upper extremities with satisfactory function and stability. This article presents the indications, operative technique, and follow up.