Recombinant expression of black sesame polyphenol oxidase and its enzymatic properties / 生物工程学报

To investigate the enzyme properties of the black sesame polyphenol oxidase (BsPPO), a synthesized Bsppo gene was cloned into the vector pMAL-c5x and expressed in E. coli. Subsequently, the MBP fusion label in the recombinant protein was removed by protease digestion after affinity purification. The synthesized Bsppo gene contained 1 752 bp which encodes 585 amino acids with a deduced molecular weight of 65.3 kDa. Transformation of the recombinant vector into E. coli BL21(DE3) resulted in soluble expression of the fusion protein MBP-BsPPO. The enzymatic properties of the recombinant BsPPO was investigated after MBP fusion tag excision followed by affinity purification. The results demonstrated that the optimal temperature and pH for BsPPO was 25°C and 4.0, respectively. BsPPO exhibited a good stability under low temperature and acidic environment. Low-intensity short-term light exposure increased the activity of BsPPO. Cu²⁺ could improve the activity of BsPPO while Zn²⁺ and Ca²⁺ showed the opposite effect. BsPPO could catalyze the oxidation of monophenols, diphenols, and triphenols, and exhibited good catalytic activity on l-tyrosine and vanillic acid. Moreover, BsPPO exhibited high catalytic activity on black sesame metabolites, including 2-methoxy cinnamic acid, indole-3-carboxylic acid and phloretin. These results may serve as a basis for further characterization of BsPPO.

Comparison of two mouse models of alcoholic liver disease induced by oral ethanol gavage or Lierber-DeCarli ethanol liquid diet / 中国比较医学杂志

Objective To select a simple, stable and reliable mouse model of alcoholic liver disease. Methods The mouse models of alcoholic liver disease were induced by oral gavage ethanol or Lierber?DeCarli ethanol liquid diet for 8 weeks. The food intake and body weight were recorded. Pathological changes were examined using HE staining. Liver injury was assessed by the activities of serum ALT, AST, AKP and γ?GT, and serum and hepatic TC and TG. Results After modeling, both models showed significantly increased activities of serum ALT, AST, AKP, and contents of serum and hepatic TG (P<0?05), indicating the successful development of alcoholic steatohepatitis. However, oral ethanol gavage led to body weight loss and weak mental state. Ethanol liquid diet less affected the body weight and mental state. Ethanol liquid diet enhanced liver to?body weight ratio and serum TC, but oral gavage of ethanol did not. The changes of serum ALT, AST, serum and hepatic TG, and hepatic steatosis in the ethanol liquid diet models were more severe than those in the oral gavage ethanol models, suggesting that Lierber?DeCarli ethanol liquid diet led to more serious liver injury than oral gavage ethanol. Conclusions Lierber?DeCarli ethanol liquid diet model is better than oral gavage ethanol model, and is more suitable for studies on mechanisms and evaluation of hepato?protective drugs for alcoholic liver disease.

Effects of peptide-based enteral nutrition on inflammatory response and immune function in intestinal mucositis rat / 中华临床营养杂志

Objective To evaluate the effects of peptide-based enteral nutrition (PBEN) on inflammatory response and immune function in rats with intestinal mucositis.Methods 48 Sprague-Dawley male rats were randomly divided into 6 groups (all n =8):basal feed group (BFG),PBEN group (PBENG),intact protein enteral nutrition group (IPENG),methotrexate (MTX) + BFG,MTX + PBENG,and MTX + IPENG.The rats in MTX + BFG,MTX + PENG,and MTX + IPENG were intraperitoneal injected with MTX 10 mg/kg on day 0 and day 6 to induce sustained intestinal injury.From day 1,BFG and MTX + BFG were fed with basal feed,PBENG and MTX + PBENG with PBEN,IPENG and MTX + IPENG with IPEN.The daily energy intake of each rat was 1.80 kJ/g body weight.All the rats were sacrificed on day 11.The pathological changes of intestinal tissue were observed with HE staining,the levels of tissue myeloperoxidase (MPO),nitric oxide (NO),inducible nitric oxide synthase (iNOS),the thymus index and spleen gland index of intestinal tissue were measured using colorimetry,and the serum levels of immunoglobulins IgG,IgA,and IgM were determined with enzyme-linked immunosorbent assay.Results There were no significant differences among BFG,PBENG,and IPENG in each index.Serious injury of intestinal mucosa was observed in MTX groups.Significant differences were noted in all indexes between MTX + BFG and BFG (all P ＜0.05).The mucosal damage score (Chiu score) and the level of MPO and iNOS in MTX + PBENG were significantly lower than those in MTX + BFG [2.3 ± 0.69vs.2.96 ± 0.75,P =0.003 ; (2.30 ± 0.42) U/g tissue vs.(2.98 ± 0.23) U/g tissue,P =0.040 ; (0.37 ±0.06) U/mg prot vs.(0.44 ±0.10) U/rag prot,P =0.030] ; the serum levels of IgG and IgA were significantly higher than those in MTX + BFG (P =0.015,P =0.021) ; however,the levels of NO and IgM were not significantly different between the 2 groups (P =0.597,P =0.160).There were no statistically significant differences between MTX + IPENG and MTX + BFG in terms of the indexes (all P ＞ 0.05).Conclusion PBEN can reduce the inflammation response and improve the immune function in intestinal mucositis rat.

Establishment and assessment of a rat model of persistent intestinal mucosal injury induced by methotrexate / 中国实验动物学报

Objective To establish a rat model of persistent intestinal mucosal injury.Methods The rat model of persistent intestinal mucosal injury was induced by intraperitoneal injection of methotrexate.The food intake and body weight of all the rats were recorded.Pathological changes were observed using HE staining, the level of D-lactate and diam-ine oxidase in plasma, and myeloperoxidase and malondiadehyde in the intestinal tissue were measured by biochemistry. Results After modeling, the rat body weight and food intake were decreased.On day 4, the scores of mucosal damage, the levels of plasma D-lactate, DAO, MPO and MDA were significantly increased (P<0.05).On day 5, the intestinal damages of rats began to restore, and there was no significant difference among groups on day 6.The symptoms after the secondary injection were similar to those after the first injection, and the rats recovered gradually at day 12.Conclusions Intestinal mucosal injury in rats induced by 20 mg/kg MTX is an acute injury process, the course only lasts for 4-5 days. Intermittent injections twice of 10 mg/kg MTX can cause persistent intestinal mucosal injury in rats.This persistent injury model is more suitable for nutritional therapy evaluation in medium-and long-term studies of nutritional therapy.

Application effect of family intervention model in early Alzheimer's disease patients' family / 中国实用护理杂志

Objective To investigate the impact of Friedman family intervention model on the personal life ability and psychological status of caregivers of early Alzheimer's disease patients.Methods 66 Alzheimer's disease patients,according to the random sequence,were divided into the study group and the control group with 33 patients in each group respectively.The control group received routine geriatric care,the study group was given Friedman family intervention model on the basis of routine geriatric care.Two groups were estimated with Life Scale Index and ADL before intervention and two months after intervention respectively,and the matching caregiver were evaluated with Symptom Checklist-90 (SCL-90).Results Compared with the control group,the quality of daily life after the intervention of the study group was significantly improved,and the differences of daily living skills between two groups were statistically significant.The differences of the SCL-90 total score and depression,anxiety,somatization,interpersonal factor scores of caregivers between the two groups were statistically significant after two months of intervention.Conclusions The application of Friedman family intervention model plays a significant role in the improvement of the quality of daily life and daily living skills in patients with Alzheimer's disease,and can improve the psychological status of the caregivers of AD patients.

Lactobacillus inhibit adhesion of Staphylococcus aureus to HeLa cells / 生物工程学报

To assess the ability of the previously selected human vaginal isolates of Lactobacillus crispatus (L. crispatus) T79-3, T90-1 and Lactobacillus jensenii (L. jensenii) T118-3, T231-1 to inhibit the growth of Staphylococcus aureus and block their adhesion to HeLa cells. The inhibitory bioactive substances produced by these Lactobacillus were also identified. Inhibitory substances interaction tests were carried out by using a streak-diffusion method on agar plates. Three types of interaction were performed to determine the inhibitory effect of Lactobacillus on adhesion of Staphylococcus aureus to HeLa cells: Exclusion Group (Lactobacillus and HeLa followed by pathogens), Competition Group (Lactobacillus, HeLa and pathogens together) and Displacement Group (pathogens and HeLa followed by the addition of Lactobacillus). The number of HeLa cells adhered to Staphylococcus aureus was quantified by bacteria colony counts on LB plate. The results showed that lactic acids produced by the Lactobacillus are the main substances that can inhibit Staphylococcus aureus growth and there is variation among the three types of interaction regarding the inhibitory activity against Staphylococcus aureus. The effects of Lactobacillus on blocking the adhesion to HeLa cells were concentration dependent. All four Lactobacillus isolates displayed the ability to inhibit Staphylococcus aureus growth and block Staphylococcus aureus adherence to HeLa cells. Exclusion Group was the most effective, and T79-3 showed greater capacity to block Staphylococcus aureus adherence compared with the other three isolates. The present study suggests the potential ability of L. crispatus T79-3 as probiotic for the treatment and prevention of urogenital infections in women.

Selection and genotyping of lactobacillus with potential preventive effect by repetitive element sequence-based PCR analysis / 生物工程学报

We selected and characterized isolates of Lactobacillus crispatus (L. crispatus) for potential preventing infections of the female reproductive tract. We cultured vaginal swabs from healthy volunteers on de Man, Rogosa and Sharpe (MRS) agar and identified the isolates at the species level by 16S rRNA sequence and genotyped the isolates of Lactobacillus by PCR amplification of repetitive bacterial DNA elements (rep-PCR). Furthermore, 10 L. crispatus strains were assessed for hydrogen peroxide (H2O2) and acid production. Overall 65 isolates were confirmed to be Lactobacillus by sequence analogy, among them 19 were L. crispatus, 17 were Lactobacillus jensenii and 12 were Lactobacillus fermentum. rep-PCR produced specie and strain-specific genomic fingerprints for the Lactobacillus isolates. The selected 10 L. crispatus isolates produced highly acidic environment after growth in MRS. The isolates T22-3 and T29-5 demonstrated high production of H2O2. This study indicated that there are individual differences with vaginal Lactobacillus colonization, and strain diversity within vaginal L. crispatus isolates, T22-3 and T29-5 might be candidates for restoring urogenital health environment in females.

PCR-based sequencing for detection and genotyping of human papillomavirus in 325 cervical cell specimens from Beijing area / 生物工程学报

To evaluate PCR-sequencing for clinical detection of human papillomavirus (HPV) genotypes in cervical cell specimens, we applied PCR-sequencing to HPV detection and genotyping by general primer PGMY09/11, which targets the HPV most conserved L1 gene. Samples with multiple infections were subjected to HPV type-specific PCR. Among the 325 cervical samples, 228 were HPV positive, of which 66 showed multiple infections. In all, 27 different HPV genotypes were identified, with HPV 16 being the most prevalent, followed by HPV 58 and 52. The prevalence of high-risk HPV infection increased with the severity of cervical lesions (P < 0.05), whereas the proportion of multiple infections declined significantly from LSIL to SCC (P < 0.05). Both rates of overall and high-risk HPV infection were the highest in 21-30 age groups. There was substantial agreement between the HC2 and PCR-sequencing assay for detection of high-risk HPV (kappa = 0.675). PCR-sequencing was effective in HPV detection and genotyping, and it could be potentially applied to large scale HPV screening.

Significance of metallothionein expression in invasive ductal breast cancer / 中国病理生理杂志

AIM:To asses the presence and clinical significance of metallothionein,(MT) in primary invasive ductal carcinoma of the breast. METHOD: 96 cases of routinely fixed and paraffin-embedded primary breast carcinomas were investigated with the labelled avidin biotin immunohistochemical method. RESULTS: The positive staining for MT observed was 52.1% (50/96). In most cases both nuclear and cytoplasmic staining was seen. A statistically association was found between MT positive staining and nuclear grade( P