[Research progress in methylation modification in tooth root development].

Methylation modification is one of the most common epigenetic modification regulation in eukaryotes, including histone methylation, DNA methylation, RNA methylation, etc., which plays an important regulatory role in physiological processes and pathologic occurrence and development. Tooth root development is carried out by both epithelial and mesenchymal cells and involves a variety of cell-molecular interactions. In recent years, a large number of studies have found that methylation plays a key role in the regulation of tooth root development and expands the mechanism network of tooth root development. In this paper, we review the role and mechanism of methylation modification during root development.

[Effects of comprehensive treatment of infected wounds in patients with iatrogenic Cushing's syndrome].

Objective: To investigate the characteristics and comprehensive treatment of infected wounds in patients with iatrogenic Cushing's syndrome. Methods: A retrospective observational study was conducted. From May 2012 to December 2021, the data of 19 patients with iatrogenic Cushing's syndrome discharged from the Department of Burns and Plastic Surgery of the First Affiliated Hospital of Guangxi Medical University were collected, including 8 males and 11 females, aged 28-71 (56±11) years, with 12 cases of infected acute wounds and 7 cases of infected chronic wounds. The lesions were located in the limbs, perianal, and sacrococcygeal regions, with original infection ranging from 9 cm×5 cm to 85 cm×45 cm. After admission, the patients were performed with multidisciplinary assisted diagnosis and treatment, and the wounds were treated with debridement and vacuum sealing drainage, according to the size, severity of infection, suture tension, and bone and tendon tissue exposure of wounds, direct suture or autologous skin and/or artificial dermis and/or autologous tissue flap transplantation was selected for wound repair. The levels of cortisol and adrenocorticotropic hormone (ACTH) of patients at 8:00, 16:00, and 24:00 within 24 h after admission were counted. After admission, the number of operations, wound repair methods, and wound and skin/flap donor site healing of patients were recorded. During follow-up, the wounds were observed for recurrent infection. Results: The cortisol levels of 16 patients at 8:00, 16:00, and 24:00 within 24 h after admission were (130±54), (80±16), and (109±39) nmol/L, respectively, and ACTH levels were (7.2±2.8), (4.1±1.8), and (6.0±3.0) pg/mL, respectively; and the other 3 patients had no such statistical results. After admission, the number of surgical operation for patients was 3.4±0.9. The following methods were used for wound repair, including direct suturing in 4 cases and autologous skin and/or artificial dermis grafting in 9 cases, of which 2 cases underwent stage Ⅱ autologous skin grafting after artificial dermis grafting in stage Ⅰ, and 6 cases had pedicled retrograde island flap+autologous skin grafting. The wound healing was observed, showing that all directly sutured wounds healed well; the wounds in 6 cases of autologous skin and/or artificial dermis grafting healed well, and the wounds in 3 cases also healed well after the secondary skin grafting; the flaps in 4 cases survived well with the wounds in 2 cases with distal perforators flap arteries circumfluence obstacle of posterior leg healed after stage Ⅱ debridement and autologous skin grafting. The healing status of skin/flap donor sites was followed showing that the donor sites of medium-thickness skin grafts in the thigh of 4 cases were well healed after transplanted with autologous split-thickness grafts from scalp; the donor sites of medium-thickness skin grafts in 3 cases did not undergo split-thickness skin grafting, of which 2 cases had poor healing but healed well after secondary skin grafting 2 weeks after surgery; the donor sites of split-thickness skin grafts in the head of 2 patients healed well; and all donor sites of flaps healed well after autologous skin grafting. During follow-up of more than half a year, 3 gout patients were hospitalized again for surgical treatment due to gout stone rupture, 4 patients were hospitalized again for surgical treatment due to infection, and no recurrent infection was found in the rest of patients. Conclusions: The infected wounds in patients with iatrogenic Cushing's syndrome have poor ability to regenerate and are prone to repeated infection. Local wound treatment together with multidisciplinary comprehensive treatment should be performed to control infection and close wounds in a timely manner, so as to maximize the benefits of patients.

[Multivariate analysis of the effect of two liver resection methods on the survival outcome of patients with intrahepatic cholangiocarcinoma].

Objective: To investigate the effect of anatomical hepatectomy and non-anatomic hepatectomy in the treatment of elderly patients with intrahepatic cholangiocarcinoma (IHCC) and their impact on survival outcomes. Methods: In this study, a retrospective method was used to select elderly patients with IHCC who were surgically treated in Shangqiu First People's Hospital from April 2014 to April 2018, and were divided into anatomic resection group and non-anatomical resection group according to the surgical methods they received.The factors affecting the survival outcome of IHCC in the two liver resection methods were analyzed and compared, as well as the effects of liver cirrhosis rate, TNM stage, ascites rate, lymph node metastasis rate, and vascular invasion rate on survival. Results: A total of 181 cases were included in this study, including 87 cases in the anatomical resection group, with 54 males and 33 females, aged (71.4±5.2) years old;There were 94 cases in the non-anatomical resection group, including 49 males and 45 females, aged (70.8±4.8) years.The 3-year survival rate of the anatomical resection group was 41.4% (36/87), which was higher than that of the non-anatomical resection group (25.5% (24/94), the difference was statistically significant (P<0.05);The median survival time of the anatomic resection group was longer than that of the non-anatomical resection group, and the difference was statistically significant P<0.05;The patient's TNM stage was stage III [OR (95%CI): 2.168 (1.245-3.776)], lymph node metastasis [1.664 (1.087-2.545)], and vascular invasion [1.883 (1.167-3.038)] was an independent risk factor for death 3 years after surgery (P<0.05), The patient's anatomical liver resection was a protective factor for the 3-year follow-up survival (P<0.05). Conclusion: The postoperative survival of elderly patients with IHCC is affected by many factors, but anatomic liver resection is beneficial to prolong the survival time of patients.

Prostacyclins and pulmonary arterial hypertension in children.

OBJECTIVE: Despite its low incidence, pulmonary hypertension in children places a substantial burden on families and society because survival can be shorter than 10 months and treatment options are limited and ineffective. Drugs to treat pulmonary hypertension include endothelin antagonists, phosphodiesterase type 5 inhibitors and prostacyclin, which is the most widely used to treat pediatric pulmonary hypertension. The main aim of this study was to provide a comprehensive overview of the advantages and disadvantages of prostacyclin and its analogs for treating pulmonary hypertension in children. MATERIALS AND METHODS: To retrieve a thorough collection of studies, we performed a search in PubMed using the following combination of keywords: (Prostacyclins) or (Epoprostenol) or (Iloprost) or (Treprostinil) or (Beraprost), (children) and (pulmonary arterial hypertension). The time limits used for the search were December 1983 to May 2021. RESULTS: The search retrieved a total of 238 articles. Titles and abstracts of articles were screened for relevance, and all relevant articles published in English were included. CONCLUSIONS: Epoprostenol can be effective against severe pulmonary hypertension. Iloprost can treat severe persistent pulmonary hypertension in newborns and inhaled iloprost can be used in pulmonary vasoreactivity testing. Treprostinil is a long-acting prostacyclin analog, and it shows the highest antiproliferative activity among prostacyclins. Beraprost may be effective in premature infants, but available evidence comes from only one patient, so more clinical testing is needed.

[Research progress in the identification and lineage differentiation of skeletal stem cell].

Skeletal system contains various stem cell niches in which the self-renewal and differentiation of different kinds of stem cells are supported. Stem cell-based therapy has been applicated variedly. The skeletal stem cells (SSC), which are mesenchyme-derived and skeletal-lineage committed progenitors, can be found in the skeletal system. They are able to self-renew and colone both in vivo and in vitro. SSC have the potential of multi-directional differentiation to cartilage, bone, adipocytes and marrow stroma. Several types of SSC have been identified based on lineage tracing and single-cell RNA sequencing technique. Compared to mesenchymal stem cells, SSC are groups of less heterogeneous cells with accurate surface marker and identifiable biological behavior. Thus, clarifying the properties of SSC might provide new insight for stem cell therapy. In this article, the authors retrieved and reviewed SSC researches mainly focusing on the identification, spatio-temporal distribution and functional characteristics of SSC. The application of scRNA-seq in skeletal stem cell identification and functional study was also discussed.

Prediction of pathologic responders to neoadjuvant chemoradiotherapy by diffusion-weighted magnetic resonance imaging in locally advanced esophageal squamous cell carcinoma: a prospective study.

This study aims to investigate the role of diffusion-weighted magnetic resonance imaging (DW-MRI) in ESCC patients receiving neoadjuvant concurrent chemoradiotherapy (CCRT), and the efficacy of apparent diffusion coefficient (ADC) values in predicting pathologic response to neoadjuvant CCRT. Twenty-eight locally advanced ESCC patients treated with neoadjuvant CCRT followed by radical resection were prospectively enrolled. DW-MRI was recommended to be performed within 2 weeks before and 4-6 weeks after neoadjuvant CCRT. The calculated ADCs pre- (ADC1) and post- (ADC2) neoadjuvant CCRT, the definite (ΔADC) and percentage changes (ΔADC%) were analyzed for the efficacy of predicting pathologic response to neoadjuvant CCRT. Twenty patients had been identified as responders (tumor regression grade 1-2). Among them, ADC2 (3.02 ± 0.84 vs. 2.12 ± 0.44 × 10-3 mm2/s, P = 0.001) and ΔADC (1.22 ± 0.78 vs 0.64 ± 0.26 × 10-3 mm2/s, P = 0.007) were significantly higher than those of nonresponders (tumor regression grade: 3-5). Receiver operating characteristic analysis revealed that ADC2 exhibited an overall accuracy of in 71.4% in predicting pathologic response, with a sensitivity of 60.0%, a specificity of 100%, a positive predictive value of 100%, and a negative predictive value of 50.0%, when 3.04 × 10-3 mm2/s was used as the cutoff value. ADC value could be useful in predicting pathologic response to neoadjuvant CCRT in ESCC patients. High postneoadjuvant CCRT ADC is a predictive indicator for good response.

[Efficacy of Weitan Waifu patch on the postsurgical gastroparesis syndrome of gastrointestinal cancer: a multi-center trial].

Objective: To investigate the safety and efficacy of the Weitan Waifu patch on the postsurgical gastroparesis syndrome (PGS) of gastrointestinal cancer. Methods: The multi-center, double-blind, randomized controlled trial was conducted with superiority design. Patients with PGS of gastrointestinal cancer diagnosed in 4 AAA hospitals and the abdominal symptom manifested as cold syndrome by Chinese local syndrome differentiation were recruited. These patients were randomly divided into two groups according to 1∶1 proportion. Placebo or Weitan Waifu patch was applied in control group or intervention group, respectively, based on the basic treatments, including nutrition support, gastrointestinal decompression, promoting gastric dynamics medicine.Two acupuncture points (Zhongwan and Shenque) were stuck with placebo in control group or patch in treatment group. The intervention course was 14 days or reached the effective standard. Results: From July 15, 2013 to Jun 3, 2015, 128 participants were recruited and 120 eligible cases were included in the full analysis set (FAS), and 60 cases in each group. 88 cases were included in the per-protocol set (PPS), including 45 cases in the treatment group and 43 cases in the control group. In the FAS, the clinical effective rate in the treatment group was 68.3%, significantly superior than 41.7% of the control group (P=0.003). The medium time of effective therapy in the treatment group was 8 days, significantly shorter than 10 days in the control group (P=0.017). In the FAS, 3 adverse events occurred in the treatment group, including mild to moderate decrustation, pruritus and nausea. The incidence rate of adverse events was 5.0% (3/60) and these symptoms were spontaneously remitted after drug withdrawal. No severe adverse events were observed in the control group. There was no significant difference between these two groups (P=0.244). Conclusion: Weitan Waifu patch is a safely and effectively therapeutic method for patients with PGS (cold syndrome) of gastroenterological cancer. Trial registration: International Standard Randomized Controlled Trial Number Register, ISRCTN18291857.

[The CK2 inhibitor quninalizarin enhances the anti-proliferative effect of icotinib on EGFR-TKIs-resistant cell lines and its underlying mechanisms].

OBJECTIVE: To explore whether quninalizarin, an specific inhibitor of protein kinase CK2, could sensitize icotinib in EGFR-TKIs (epithelial growth factor receptor-tyrosine kinase inhibitor)-resistant cell lines and uncover the underlying mechanisms. METHODS: MTT assay was performed to evaluate the inhibitory effect of quninalizarin, icotinib or the combination of both on cell proliferation in several lung adenocarcinoma cell lines. Western blot assay was used to assess if combined inhibition of EGFR and protein kinase CK2 by icotinib and quninalizarin, exerts effect on the expression and phosphorylation of major proteins of EGFR signaling pathways. RESULTS: The IC50 of HCC827, H1650, H1975 and A549 cells for icotinib were (8.07±2.00)µmol/L, (66.01±6.64)µmol/L, (265.60±9.47)µmol/L and (87.88±6.8)µmol/L, respectively, indicating that HCC827 cells are sensitive to icotinib, and the H1650, H1975 and A549 cells are relatively resistant to icotinib. When treated with both quninalizarin and icotinib in the concentration of 50 µmol/L, the viability of H1650, H1975 and A549 cells was (40.64±3.73)%, (65.74±3.27)% and (44.96±0.48)%, respectively, significantly lower than that of H1650, H1975 and A549 cells treated with 50 µmol/L icotinib alone (55.05±1.22)%, (71.98±1.60)% and (61.74±6.18)%, respectively (P<0.01 for all). When treated with both 100 µmol/L quninalizarin and 100 µmol/L icotinib, the viability of H1650, H1975 and A549 ells were (23.35±0.81)%, (55.70±1.03)%, (33.42±1.33)%, respectively, significantly lower than the viability of H1650, H1975 and A549 cells treated with 100 µmol/L icotinib alone (40.57±2.65)%, (62.40±2.05)% and (44.97±8.20)%, respectively, (P<0.01 for all). The two-way ANOVA analysis showed that compared with the viability of EGFR-TKIs-resistant cells (H1650, H1975, A549) treated with 50 µmol/L and 100 µmol/L icotinib alone, the viability of cells treated with icotinib and quinalizarin were significantly suppressed, and the differences were statistically significant (P<0.01). In addition, the phosphorylation form of Akt and ERK (namely p-Akt and p-ERK) were significantly down-regulated by treating with quninalizarin and icotinib together in the H1650 cells while the expression of Akt and ERK changed little. CONCLUSIONS: Quinalizarin, as a specific CK2 inhibitor, may overcome icotinib resistance by inhibiting proliferation mediated by Akt and ERK in human lung adenocarcinoma cell lines, and enhances the suppressive effect of icotinib on the proliferation of EGFR-TKIs-resistant human lung adenocarcinoma cells.

Open reduction and internal fixation for the treatment of fractures of the lateral humeral condyle with an early delayed presentation in children: a radiological and clinical prospective study.

AIMS: The treatment of late presenting fractures of the lateral humeral condyle in children remains controversial. METHODS: We report on the outcome for 16 children who presented with a fracture of the lateral humeral epicondyle at a mean of 7.4 weeks (3 to 15.6) after injury and were treated surgically. RESULTS: The mean follow-up was four years (1.1 to 8.9), at which time the mean age of the patients was 8.7 years (3.2 to 17.8). The mean Dhillon functional score improved from 3.3 to 5.6 and the mean overall scores improved from 5.6 to 8.5. A total of seven patients had a fishtail deformity and eight had partial lateral epiphyseal closure. None had avascular necrosis. MRI showed an abnormal cartilage signal, incongruence of the joint surface and partial premature closure of the lateral physis in four patients. DISCUSSION: Neither age at the time of injury, the time interval between injury and operation, nor the pre-operative function were correlated with the incidence of complications. These results support the use of internal fixation for children with a lateral humeral epicondylar fracture with a delayed presentation. TAKE HOME MESSAGE: Open reduction and internal fixation yielded a satisfactory outcome within 16 weeks in children with a lateral humeral epicondylar fracture with a delayed presentation.

MicroRNA-215 functions as a tumor suppressor and directly targets ZEB2 in human pancreatic cancer.

It has been shown that microRNA-215 (miR-215) is dysregulated in several human malignancies, and this correlates with tumor progression. However, its expression and function in pancreatic cancer is still unclear. The aim of this study was to explore the effects of miR-215 on pancreatic cancer formation and progression. Using quantitative RT-PCR, we detected miR-215 expression in pancreatic cancer cell lines and primary tumor tissues. The association of miR-215 expression with clinicopathological factors and prognosis was also analyzed. We then observed the effects of miR-215 on the biological behavior of pancreatic cancer cells. Lastly, the potential regulatory function of miR-215 on ZEB2 expression was investigated. miR-215 expression levels were significantly downregulated in pancreatic cancer samples and cell lines. Decreased miR-215 expression was significantly associated with large tumor size, advanced TNM stage, lymph node metastasis, vessel invasion, and lower overall survival. Multivariate regression analysis corroborated that downregulation of miR-215 was an independent unfavorable prognostic factor. Overexpression of miR-215 inhibited pancreatic cancer cell proliferation, invasion, and migration; promoted cell apoptosis in vitro; and suppressed tumorigenicity in vivo. Further, ZEB2 was confirmed as a direct target of miR-215 by using a luciferase reporter assay. These findings indicate that miR-215 may act as a tumor suppressor in pancreatic cancer cells, and could serve as a novel therapeutic target for miR-based therapy.

FOXO1 is a tumor suppressor in cervical cancer.

Forkhead box protein O1 (FOXO1) is an important transcriptional regulator of cell proliferation, and is considered essential for tumor growth and progression. However, the function of FOXO1 in human cervical cancer remains unclear. In this study, we investigated the role of FOXO1 in cervical cancer. Our results showed that FOXO1 expression was lower in cervical cancer than in cervical intraepithelial neoplasia and normal cervix by immunohistochemical analysis (P < 0.05). The level of FOXO1 in high-grade lesions was significantly lower than in low-grade lesion (P < 0.05), indicating that deficient expression of FOXO1 is involved in tumor progression and significantly associated with late-stage tumors (P < 0.05), which was further supported by clinicopathological, real-time polymerase chain reaction, and Western blotting analysis. Moreover, we confirmed that the overexpression of FOXO1 remarkably repressed cell growth and blocked cell proliferation, accompanied by cell-cycle arrest in the G2/M phase and upregulation of caspases-3 and -9 gene expression. Collectively, our data suggest that FOXO1 plays a vital role in inhibiting cervical cancer development by inducing cell-cycle arrest and apoptosis. FOXO1 expression is a favorable prognostic factor for human cervical cancer.

Effects of bovine serum albumin on boar sperm quality during liquid storage at 17°C.

This study aimed to investigate the effects of bovine serum albumin (BSA) on boar sperm quality during liquid storage at 17°C. Boar semen samples were collected and diluted with Modena containing different concentrations (0, 1, 2, 3, 4, 5 and 6 g/l) of BSA, and sperm motility, plasma membrane integrity, acrosome integrity, total antioxidative capacity (T-AOC) activity and malondialdehyde (MDA) content were measured and analysed. The results showed that Modena supplemented with 3, 4 and 5 g/l BSA could improve boar sperm motility, effective survival time and plasma membrane integrity (p < 0.05), decrease MDA content (p < 0.05), while no statistical difference was observed for sperm acrosome integrity and T-AOC activity among these three groups (p > 0.05). The semen sample diluted with Modena containing 4 g/l BSA could achieve optimum effect, and sperm survival time was 7.5 days. After 7 days preservation, sperm motility, plasma membrane integrity and acrosome integrity were 54%, 49% and 78%, respectively. T-AOC activity and MDA content were 1.03 U/ml and 17.5 nmol/ml, respectively. In conclusion, Modena supplemented with BSA reduced the oxidative stress and improved the sperm quality of boar semen during liquid storage at 17°C, and 4 g/l BSA was the optimum concentration. Further studies are required to obtain more concrete results on the determination of antioxidant capacities of BSA in liquid preserved boar semen.

Genetic diversity of Saccharum spontaneum from geographical regions of China assessed by simple sequence repeats.

Saccharum spontaneum is the most variable wild relative of sugarcane with potential for use in sugarcane improvement programs. In order to help preserve and exploit this species, 152 accessions from eight major geographical regions in China, including Hainan, Guangdong, Guangxi, Yunnan, Sichuan, Guizhou, Fujian, and Jiangxi provinces, were investigated by analyzing 20 simple sequence repeats (SSRs), including 11 genomic SSRs (gSSRs) and nine SSRs developed from expressed sequence tags (EST-SSRs). A total of 454 alleles were generated by the 20 SSRs, with 295 and 159 alleles detected by gSSRs and EST-SSRs respectively. The Mantel test showed significant correlation between genetic matrixes among the studied accessions revealed by gSSRs versus EST-SSRs, although the average polymorphism of EST-SSRs (17.7) was much lower than that of gSSRs (26.8). Among the eight provinces, collections from Guizhou were the most diverse and those from Guangdong were the most distinct. Clustering analysis and principal component analysis accordantly classified the accessions into four groups, which were "Southwest group", "Hainan group", "Guangdong group", and "Guangxi group", based on the geographical origin of the major accessions in each group, demonstrating that geographical factors play an important role in the pattern of genetic structure of Chinese S. spontaneum. As two (Guizhou and Yunnan) of the three provinces with highest genetic diversity are located in southwest China, we concluded that southwest China is the region with the highest genetic diversity of S. spontaneum.

Heralded generation of multipartite entanglement for one photon by using a single two-dimensional nonlinear photonic crystal.

We propose a compact scheme for the heralded generation of single-photon multipartite entanglement by using a single two-dimensional nonlinear photonic crystal. Studies have shown that by appropriate structure design, the single-photon entanglement shared among three spatially distinct optical modes can be generated through three concurrent spontaneous parametric down-conversion processes by using the other photon in an identical spatial mode as a trigger. Furthermore, we analyze the entanglement of such heralded single-photon tripartite W-type state theoretically. This method can be expanded for the heralded single-photon N-partite entanglement generation. This compact and stable quantum light source may act as a key ingredient in quantum information science.

Cloning and characterization of A cDNA encoding prohibitin1 from Lampetra japonica and its expression analysis.

To investigate that prohibitin is probably concerned in B--lymphocyte--like cells mediated signal pathways in Lamprey, a necessary and fundamental plan is firstly conducted. A full--length cDNA encoding the prohibitin1 protein was cloned from Lampetra japonica by EST sequence analysis in L. japonica leukocyte cDNA library conducted by our laboratory. Prohibitin1 contains a 828 bp open reading frame, encoded 275 amino acids residues, and molecular weight is 29.9517 KD, isoelectric point is 6.93, consists of 31 negatively charged amino acids residues (Asp+Glu) and 21 positively charged ones (Arg+Lys). The Prohibitin1 gene sequence from L. japonica is 71% identical to the ones of other 24 eukaryotic species, which shows the putative prohibitin1 gene is highly conserved. Western blotting analysis results showed the recombinant proteins were the target proteins in prokaryote. Real--time quantitative polymerase chain reaction analysis indicated that the expression of the prohibitin1 gene is significantly up--regulated in leukocyte, heart and gill of L. japonica by LPS stress treatment. In conclusion, we have cloned and identified the full--length cDNA of Prohibitin1 in L. japonica and found that it was related to adaptive immune response in lamprey for the first time.

Development of the osseous and cartilaginous acetabular index in normal children and those with developmental dysplasia of the hip: a cross-sectional study using MRI.

The purpose of this study was to investigate the development of the osseous acetabular index (OAI) and cartilaginous acetabular index (CAI) using MRI. The OAI and CAI were measured on the coronal MR images of the hip in 81 children with developmental dysplasia of the hip (DDH), with a mean age of 19.6 months (3 to 70), and 241 normal control children with a mean age of 5.1 years (1 month to 12.5 years). Additionally the developmental patterns of the OAI and CAI in normal children were determined by age-based cross-sectional analysis. Unlike the OAI, the normal CAI decreased rapidly from a mean of 10.17° (sd 1.60) to a mean of 8.25° (sd 1.90) within the first two years of life, and then remained constant at a mean of 8.04° (sd 1.65) until adolescence. Although no difference in OAI was found between the uninvolved hips in children with unilateral DDH and normal hips (p = 0.639), the CAI was significantly different between them both (p < 0.001). The normal CAI has fully formed at birth, and is maintained constantly throughout childhood. The CAI in the unaffected hips in children with unilateral DDH is also mildly dysplastic.

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.

Effects of vitamin E supplementation in the extender on frozen-thawed bovine semen preservation.

The maturing sperm cells discard the majority of their cytoplasm during the final stages of spermatogenesis and lose some of their defense enzymes. The purpose of this study was to investigate the effects of vitamin E supplementation on standard semen quality parameters and antioxidant activities of frozen-thawed bovine sperm. Vitamin E was added at concentrations of 0.5, 1.0, 1.5 and 2.0 mg/ml to bovine semen cryoprotective medium. The results showed that the sperm motility and VSL, STR values in the extender supplemented with 1.0 and 1.5 mg/ml of vitamin E, were significantly higher than that of other concentrations (P < 0.05). The percentages of acrosome-intact and membrane-intact sperm were significantly improved (P < 0.05) by supplementing with 1.5 mg/ml of vitamin E. In biochemical assays, the extender supplemented with vitamin E did not exhibit significant improvement in SOD (superoxide dismutase) levels, compared with the control (P > 0.05). Compared with other groups, CAT (catalase) levels were demonstrated to be greater with the supplementation of vitamin E at 1.0 and 1.5 mg/ml (P < 0.05). The extender supplemented with 1.5 mg/ml of vitamin E caused the highest levels of glutathione peroxidase (GSH-Px), compared with other groups (P < 0.05). The glutathione (GSH) activity was significantly higher with the supplementation of 0.5, 1.0 and 1.5 mg/ml of vitamin E, compared with 2.0 mg/ml in the vitamin E group and control (P < 0.05). Moreover, increasing the doses of vitamin E decreased sperm antioxidant activities, the extender supplemented with 2.0 mg/ml of vitamin E, caused the lowest levels of GSH-Px and GSH activities, compared with other treatment groups (P < 0.05). In conclusion, the beneficial effects of vitamin E noted in this study can be attributed to the antioxidant characteristics. Vitamin E supplementation in the extender reduced the lipid peroxidation potential and improved semen quality during freezing-thawing. More researches are needed to evaluate and understand the precise physiological role of vitamin E in reproduction.