Expression and characterization of β-N-acetylglucosaminidases from Bacillus coagulans DSM1 for N-acetyl-β-D glucosamine production / 生物工程学报

β-N-acetylglucosaminidases (NAGases) can convert natural substrates such as chitin or chitosan to N-acetyl-β-D glucosamine (GlcNAc) monomer that is wildly used in medicine and agriculture. In this study, the BcNagZ gene from Bacillus coagulans DMS1 was cloned and expressed in Escherichia coli. The recombinant protein was secreted into the fermentation supernatant and the expression amount reached 0.76 mg/mL. The molecular mass of purified enzyme was 61.3 kDa, and the specific activity was 5.918 U/mg. The optimal temperature and pH of the BcNagZ were 75 °C and 5.5, respectively, and remained more than 85% residual activity after 30 min at 65 °C. The Mie constant Km was 0.23 mmol/L and the Vmax was 0.043 1 mmol/(L·min). The recombinant BcNagZ could hydrolyze colloidal chitin to obtain trace amounts of GlcNAc, and hydrolyze disaccharides to monosaccharide. Combining with the reported exochitinase AMcase, BcNagZ could produce GlcNAc from hydrolysis of colloidal chitin with a yield over 86.93%.

Expression and evaluation of porcine circovirus type 2 capsid protein mediated by recombinant adenoassociated virus 8

Background@#Porcine circovirus type 2 (PCV2) is an important infectious pathogen implicated in porcine circovirus-associated diseases (PCVAD), which has caused significant economic losses in the pig industry worldwide. @*Objectives@#A suitable viral vector-mediated gene transfer platform for the expression of the capsid protein (Cap) is an attractive strategy. @*Methods@#In the present study, a recombinant adeno-associated virus 8 (rAAV8) vector was constructed to encode Cap (Cap-rAAV) in vitro and in vitro after gene transfer. @*Results@#The obtained results showed that Cap could be expressed in HEK293T cells and BABL/c mice. The results of lymphocytes proliferative, as well as immunoglobulin G (IgG) 2a and interferon-γ showed strong cellular immune responses induced by Cap-rAAV. The enzyme-linked immunosorbent assay titers obtained and the IgG1 and interleukin-4 levels showed that humoral immune responses were also induced by Cap-rAAV. Altogether, these results demonstrated that the rAAV8 vaccine Cap-rAAV can induce strong cellular and humoral immune responses, indicating a potential rAAV8 vaccine against PCV2. @*Conclusions@#The injection of rAAV8 encoding PCV2 Cap genes into muscle tissue can ensure long-term, continuous, and systemic expression.

Research progress on the epigenetic mechanisms of inverse relationship between Alzheimer's disease and cancer onset / 生理学报

Alzheimer's disease (AD) is currently the most prevalent neurodegenerative disease in the aging population. It is characterized by massive deposition of extracellular β-amyloid peptide and formation of intracellular neurofibrillary tangles. Cancer is also an age-related disease. Some epidemiological studies have shown an inverse relationship between AD and the onset of various types of cancers, that is, the risk of cancer in patients with AD is reduced, and vice versa. Epigenetic mechanisms play important roles in the development of AD and cancer. In this article, we will review the recent research advances on the epigenetic mechanisms of AD and cancer onset, and provide new ideas for rethinking the relevance of AD and cancer with a "holistic concept".

Association between CHRNA3 rs1051730 genotype and lung cancer risk in Chinese Han population: a case-control study / 华中科技大学学报（医学）（英德文版）

Recent population-based genome wide association studies have revealed potential susceptibility loci of lung cancer at the region of chromosome 15q25.1 containing nicotinic acetylcholine receptor genes. The loci increasing lung cancer risk has been widely identified in Caucasians, but whether this association also exists in Asians and whether this association is a direct role or mediated via tobacco smoking indirectly has not been fully established. We conducted a case-control study comprising of 210 histologically confirmed lung cancer cases and 200 healthy controls to examine rs1051730 genotyping, a single nucleotide polymorphism receiving much attention recently, and its influence on lung cancer risk as well as nicotine dependence in a Chinese Han population. Our results showed that the heterozygous C/T genotype and minor allele T conferred a significant higher risk of lung cancer than the CC homozygotes and allele C (adjusted OR=2.25, 95% CI=1.04-4.89, P=0.040 and OR=2.18, 95% CI=1.02-4.67, P=0.045 respectively). However, no association between the smoking habit and the CHRNA3 rs1051730 polymorphism was observed in this study. The results suggested that the rs1051730 polymorphism may modify susceptibility to lung cancer via a smoking-independent manner among Chinese Han population. Additional studies in vitro and in vivo are warranted to further elucidate the impact of rs1051730 on lung cancer susceptibility.

Regulation of C-type natriuretic peptides and natriuretic peptide receptor-B expression in diabetic rats renal treated by Tongluo Recipe / 中国结合医学杂志

<p><b>OBJECTIVE</b>To investigate the expression of C-type natriuretic peptides (CNP) and natriuretic peptide receptor-B (NPR-B) receptor in diabetic rats renal cortex, and the regulation by Tongluo Recipe (TLR).</p><p><b>METHODS</b>Sixty male SD rats were divided into 3 groups: the normal control group, diabetic model group and diabetic TLR group. Each group was further divided into two subgroups of ten in each, according to 4-week or 12-week observation period. Streptozotocin (STZ)-induced diabetic rats were treated with TLR (1.0 g·kg(-1)·d(-1)) for 4 and 12 weeks, respectively. (1) The essential information was collected for comparing renal mass, serum creatinine and 24 h urine albumen on each group was calculated. (2) CNP mRNA and NPR-B mRNA were detected by realtime-polymerase chain reaction (PCR) on rats renal cortex. (3) Concentration of CNP on renal cortex or serum were analyzed by enzyme-linked immunosorbent assay (ELISA). (4) Pathological evaluation and NPR-B immunostaining for renal tissue were also performed.</p><p><b>RESULTS</b>(1) CNP and NPR-B mRNA levels were detected in each treated or untreated group, with slight elevated in untreated diabetes rats administrated with STZ after 4-week and CNP mRNA level remarkable elevated at 39.21 times higher than normal control group after 12 weeks, but NPR-B mRNA level showed a remarkably down-regulation at 98.07% after 12 weeks. CNP mRNA of TLR-treated group was also elevated after 12-week treatment, but less than untreated group. (2) Concentrations of CNP in renal cortex were obviously increased in treated or untreated diabetes rats, within these groups the treatment of TLR was found more significantly on prompting CNP concentration. Comparing to normal group, serum concentrations of CNP were also increased in treated or untreated diabetic groups, but there was no difference between these diabetic groups. (3) Renal lesions like glomerular volume increased are observed mostly in the relative early stage after 4 weeks. Although TLR treated group had no significant difference in their glomerular volume, the degrees of injury of glomerulus were ameliorated, as well as the NPR-B immunostaining enhanced in glomerulus. Weakly positive immunostaining of NPR-B are observed in glomerulus of normal control, and negative in glomerulus of untreated diabetes rats administrated with STZ after 12 weeks, whereas TLR-treatment groups showed a little enhancement.</p><p><b>CONCLUSION</b>CNP and NPR-B showed different characteristic on renal cortex at different pathological period in diabetes rats, and TLR regulated their expression.</p>

Association between CHRNA3 rs1051730 genotype and lung cancer risk in Chinese Han population: A case-control study / 华中科技大学学报（医学）（英德文版）

Recent population-based genome wide association studies have revealed potential susceptibility loci of lung cancer at the region of chromosome 15q25.1 containing nicotinic acetylcholine receptor genes. The loci increasing lung cancer risk has been widely identified in Caucasians, but whether this association also exists in Asians and whether this association is a direct role or mediated via tobacco smoking indirectly has not been fully established. We conducted a case-control study comprising of 210 histologically confirmed lung cancer cases and 200 healthy controls to examine rs1051730 genotyping, a single nucleotide polymorphism receiving much attention recently, and its influence on lung cancer risk as well as nicotine dependence in a Chinese Han population. Our results showed that the heterozygous C/T genotype and minor allele T conferred a significant higher risk of lung cancer than the CC homozygotes and allele C (adjusted OR=2.25, 95% CI=1.04-4.89, P=0.040 and OR=2.18, 95% CI=1.02-4.67, P=0.045 respectively). However, no association between the smoking habit and the CHRNA3 rs1051730 polymorphism was observed in this study. The results suggested that the rs1051730 polymorphism may modify susceptibility to lung cancer via a smoking-independent manner among Chinese Han population. Additional studies in vitro and in vivo are warranted to further elucidate the impact of rs1051730 on lung cancer susceptibility.

Clinical effect of the concentrated suture fixation method on skin transplantation in the jaw and neck region / 中华烧伤杂志

<p><b>OBJECTIVE</b>To observe the clinical effect of the concentrated suture fixation method on skin transplantation on deep burn wound or wound of cicatricial deformity after burn in the jaw and neck region.</p><p><b>METHODS</b>One hundred and fourteen patients, hospitalized from April 2002 to December 2011, with deep burn or cicatricial deformity after burn in the jaw and neck region, were divided into packaging group and concentrated suture group according to the random number table. Each group had 57 patients including 48 cases with deep burn and 9 cases with cicatricial deformity. Traditional suture-package fixation method and concentrated suture fixation method were respectively used in packaging group and concentrated suture group to fix the autologous medium split-thickness skin in transplantation on wounds or scars. On post operation day (POD) 14, the skin microcirculatory perfusion flow of skin graft was measured, and the occurrence of ecchymoma, infection, and necrosis of skin in operative region were observed. The elasticity and contracture of grafted skin and scar hyperplasia on wound edge were observed 6 months after operation. Measurement data were processed with u test, while enumeration data with Fisher's exact test or Chi-square test.</p><p><b>RESULTS</b>(1) On POD 14, the skin microcirculatory perfusion flow in concentrated suture group [(2.86 +/- 0.8) V] was significantly higher than that in packaging group [(2.33 +/- 0.15) V, u = 17.776, P < 0.05]. (2) Ecchymoma occurred in 4 patients of packaging group and 3 patients of concentrated suture group, but the difference between two groups was not statistically significant (chi 2 = 0.152, P > 0.05). (3) Infection in operative region was observed in 1 patient of packaging group, while no patient in concentrated suture group showed this symptom. The difference between two groups was not statistically significant (P > 0.05). (4) Grafted skin in 6 patients of packaging group showed foliated necrosis, which was not observed on those of patients in concentrated suture group. The difference between two groups was statistically significant (P < 0.05). (5) Centipede leg-like scar hyperplasia on wound edge occurred in 21 patients in packaging group and 6 patients in concentrated suture group, and the difference between two groups was statistically significant (chi 2 = 10.920, P < 0.05). (6) Poor elasticity of grafted skin was detected in 17 patients of packaging group and 4 patients of concentrated suture group, and the difference between two groups was statistically significant (chi 2 = 9.865, P < 0.05). (7) Obvious contracture of grafted skin was observed in 15 patients of packaging group and 4 patients of concentrated suture group, and the difference between two groups was statistically significant (chi 2 = 11.684, P < 0.05).</p><p><b>CONCLUSIONS</b>Concentrated suture fixation method is suitable for application in transplantation of big sheet skin on wound in the jaw and neck region. It has high survival rate and is convenient for postoperative observation.</p>

Influence of high-voltage electrical burn on the rheological property of platelet and leukocyte in rats and the interventional effect of pentoxifylline / 中华烧伤杂志

<p><b>OBJECTIVE</b>To investigate the influence of high-voltage electrical burn (HEB) on the aggregation and adhesion of platelet and leukocyte in rats and the interventional effect of pentoxifylline (PTX).</p><p><b>METHODS</b>One hundred and eighty SD rats were divided into control, electrical burn (EB), and pentoxifylline treatment (PT) groups according to the random number table, with 60 rats in each group. (1) Ten rats were taken from each group at 15 minutes before injury for the observation of the microcirculatory perfusion of chest skin with Laser Doppler Perfusion Imager (LDPI), and the number of leukocyte adherent to mesenteric venule with Bradford Variable Projection Microscope (BVPM). Serum was collected from heart blood to determine the contents of platelet activating factor (PAF), thromboxane B2 (TXB2), prostacyclin (PGI2), P-selectin, E-selectin and L-selectin by double-antibody sandwich enzyme-linked immunosorbent assay. The ratio of TXB2 to PGI2 was calculated therefrom. (2) Model of HEB was reproduced in the remaining 50 rats of EB group and that of PT group with voltage regulator and experimental transformer (the electrical current applied to the left forelimb and exited from the right hind limb). The remaining 50 rats of control group were sham injured with the same devices without electric current. Within 2 minutes post injury (PIM), rats in control group and EB group were intraperitoneally injected with 2 mL isotonic saline, while rats in PT group were intraperitoneally injected with 2 mL pentoxifylline (50 mg/mL). At PIM 5 and 1, 2, 4, 8 hour(s) post injury (PIH), 10 rats of every group were randomly chosen at each time point for the observation of the microcirculatory perfusion of chest skin and the number of leukocytes adherent to mesenteric venule through the same method as used above, and the levels of the related factors of aggregation and adhesion of platelets and leukocytes were determined, and then the relative ratio was calculated. Data were processed with the analysis of variance of factorial design and LSD test.</p><p><b>RESULTS</b>The contents of PAF, TXB2, PGI2, P-selectin, E-selectin, L-selectin, and the ratio of TXB2 to PGI2, as well as the number of adhered leukocyte in EB group were higher, while the microcirculatory perfusion value was lower than those of control group, with F values from 854.20 to 8156.52, P values all below 0.01. The microcirculatory perfusion value and PGI2 content of PT group were higher, while the contents or number of other indexes were lower than those of EB group, with F values from 33.18 to 1033.99, P values all below 0.01. Only the data within EB group and PT group were comparable. The contents of PAF, TXB2, PGI2, P-selectin, E-selectin, L-selectin, and the ratio of TXB2 to PGI2, as well as the number of adhered leukocyte in EB group and PT group at each time point were significantly higher than those at 15 minutes before injury, while the microcirculation perfusion value was significantly lower than that at 15 minutes before injury (P values all below 0.001), with the exception of the ratio of TXB2 to PGI2 in PT group and E-selectin in EB group and PT group at PIM 5. The contents of PAF, TXB2, and E-selectin and the ratio of TXB2 to PGI2 in EB group peaked at PIH 4, and they were respectively (9.3 ± 0.9) ng/mL, (14.31 ± 0.65) nmol/mL, (271.2 ± 18.4) ng/mL and 4.62 ± 0.26. The contents of PGI2 and P-selectin, and the number of adhered leukocyte in EB group peaked at PIH 8, and they were respectively (3.98 ± 0.24) nmol/mL, (514 ± 24) ng/mL, and (25.50 ± 4.14) per 100 µm venule. The content of L-selectin peaked at PIH 2 [(876 ± 54) ng/mL]. The microcirculatory perfusion value was lowest at PIM 5 [(1.17 ± 0.10) V].</p><p><b>CONCLUSIONS</b>HEB can increase the contents of PAF, TXB2, PGI2, P-selectin, E-selectin, L-selectin, the ratio of TXB2 to PGI2, and the number of adhered leukocyte, as well as decrease the skin microcirculatory perfusion value. PTX can inhibit the aggregation and adhesion of platelets and leukocytes through increasing the content of PGI2 and decreasing contents of other factors mentioned above, thus alleviating the microcirculatory dysfunction after HEB.</p>

Sulodexide prevents diabetic nephropathy through inhibiting renal NF-κB activation and MCP-1 expression / 中华肾脏病杂志

Objective To study the effects of sulodexide on renal NF-κB activation and monocyte chemotactic protein 1 (MCP-1) expression in diabetic rats and elucidate the possible mechanism of sulodexide in preventing diabetic nephropathy (DN). Methods Wistar rats were fed with high-sucrose-high-fat diet and injected with a low dose of STZ (streptozotocin,35 mg/kg) into abdominal cavity to induce diabetes.DM rats were randomly divided into non-treated group of treatment,blood glucose (BG),triglyceride (TG),cholesterol,serum creatinine (Scr),urea nitrogen (BUN),24 h urinary albumin excretion (UAE) were measured.HE staining was performed in renal tissues for light microscopy examination of mean glomerular volume (MGV).MCP-1 expression was detected by immunohistochemical method.NF-κB activation was determined by Western blot. Results Compared with NC group,DM group and DMS group had significant elevated BG,TG and TC levels (all P＜0.01).There were no significant differences of BG,TG or TC levels between DM group and DMS group.Compared with NC group,DM group and DMS group had significant increased Scr,BUN,UAE levels (all P＜0.01).Scr,BUN,UAE levels were significantly lower in DMS group than those in DM group [(39.1±0.88) μmol/L vs (41.0±2.16) μmol/L,(9.12±1.06) mmol/L vs (9.87±0.19) mmol/L； (19.92±0.96) mg/24 h vs (25.99±0.52)mg/24 h,all P＜0.05].Compared with NC group,the MGV of DM group was significantly increased [(7.47±1.11)×105 μm3 vs (4.22±1.09)×105 μm3,P＜0.01].Compared with DM group,the MGA of DMS group was significantly reduced [(6.64±0.71)×105 μm3 vs (7.47±1.11)×105 μm3,P＜0.05],but was still increased compared with that of NC group (P＜0.01).Compared with NC group,the MCP-1 expression of DM group was significantly higher [(12.17±1.94)/HPF vs (1.19±0.70)/HPF,P＜0.01].MCP-1 expression in DSM group was significantly lower than that of DM group [(9.22± 1.61)/HPF vs (12.17±1.94)/HPF,P＜0.01],but still higher than that of control group (P＜0.01).Compared with NC group,the NF-κB activity was significantly higher in DM group [(0.89±0.07) vs (0.24±0.03),P＜0.01].Compared with DM group,NF-κB activity of DMS group was significantly lower [(0.27±0.01) vs (0.89±0.07),P＜0.01].There was no significant difference of NF-κB activity between DMS group and NC group. Conclusion Sulodexide has protective effects on diabetic nephropathy,and one of the mechanisms may involve the inhibition of NF-κB activation as well as the suppression of MCP-I expression.

Endolymphatic sac papillary tumor: a case report / 中华医学杂志(英文版)

Endolymphatic sac papillary tumor (ELST) is an extremely rare and aggressive tumor characterized by hearing loss and temporal bone destruction. A case with clinical, imaging, pathologic and treatment data is reported and relevant literature is reviewed. A 25-year-old woman, with ELST underwent craniotomy for tumor subtotal resection, and the diagnosis was confirmed by pathologic examination. Postoperative radiotherapy consisted of 50.4 Gy/28 f was given accordingly. The patient is currently alive with no signs of tumor recurrence locally and no radiation side-effects observed after one year follow-up. Complete resection is impossible in most cases, local resection, adjuvant radiotherapy may provide favored local control. A long-term follow-up is highly advocated in consideration of its slow development course.

Comparison of various methods of early management of hydrofluoric acid burn in rabbits / 中华烧伤杂志

<p><b>OBJECTIVE</b>To compare the effects of different kind of methods in the management of hydrofluoric acid burn in early postburn stage in rabbits.</p><p><b>METHODS</b>Thirty-three rabbits were inflicted with burn by 55% of hydrofluoric acid covering 5% TBSA, and were randomly divided into 3 groups, i.e. A (n = 13, with 5 ml.kg(-1).h(-1)of isotonic saline intravenous infusion), B (n = 10, with isotonic saline and 50 g/L of calcium gluconate infusion in dose of 20 mg/kg at different time points), and C (n = 10, with the same treatment as B group, and with excision of burn wound at 0.5 post burn hour) groups. The serum levels of fluorine and calcium were determined before and after various postburn hours, and the mortality rate was statistically analyzed.</p><p><b>RESULTS</b>(1) The serum level of fluorine in A (8.37 +/- 2.62 mg/L) and B (8.59 +/- 2.25 mg/L) groups reached the peak value at 1 postburn hour (PBH), which was 107 times higher than that before the burn injury. The serum level of fluorine in B group was significantly lower than that in A group at 24 PBH (P < 0.05), while that in C group declined to (6.20 +/- 0.23) mg/L, which was obviously lower than that in A and B groups (P < 0.01). (2) The serum calcium level declined after burns, reaching the lowest level at 8 to 12 PBH. and began to increase at 24 PBH. Compared with normal calcium value, the serum level of calcium in A, B and C groups declined to as much as 46%, 32% and 26%, respectively. Statistically significant difference was found between C and B groups (P < 0.01). (3) The mortality rate in the three groups within 72 PBH were 30.8%, 12.5% and 0.0%, respectively.</p><p><b>CONCLUSION</b>Early removal of burn area and calcium supplementation could help quickly decrease blood fluorine, reverse the fatal hypocalcemia and the multiple systemic toxic injury in rabbits inflicted with hydrofluoric acid injury.</p>

Study on mitochondrial DNA gene tRNA(Leu(UUR)) A3243G mutation in type 2 diabetes mellitus / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To explore the prevalence and the clinical characteristics of mitochondrial gene mutation A3243G (mt tRNA(Leu(UUR)) 3243 A-->G) in patients with type 2 diabetes mellitus (DM2) in China.</p><p><b>METHODS</b>Four hundred and twenty-eight cases of DM2 patients were selected randomly. One hundred and eighty-eight individuals were healthy controls. The mutation was assayed by PCR-restriction fragment length polymorphism technique. The target fragments of PCR were digested with restriction endonuclease Apa I.</p><p><b>RESULTS</b>mt tRNA(Leu(UUR)) 3243A-->G gene mutation was found in 2 of 428 patients with DM2, but not found in the controls. Further investigation of the relatives of the 2 patients' families revealed that 3 members were the carriers of mt tRNA A3243G gene mutation and the patients with diabetes. In addition, one proband and her son were characterized with the syndrome of mitochondrial encephalomyopathy with lactic acidosis. The diabetes of these patients is frequently accompanied by hearing impairment or deafness with maternal inheritance.</p><p><b>CONCLUSION</b>The prevalence of the mitochondrial gene A3243G mutation is 0.47% in DM2 patients in China. The data acquired in this study suggest that the clinical phenotype of these patients with A3243G should be heterogeneous.</p>