Quantitative magnetic susceptibility imaging sequence for intracranial inflammation in patients with optic neuromyelitis / 中国医师进修杂志

Objective:To identify the potential intracranial inflammation in neuromyelitis optica spectrum disorders(NMOSD) patients without supratentorial MRI lesions using quantitative susceptibility mapping (QSM).Methods:Seventy NMOSD patients and 35 age- and gender-matched healthy controls (NC) underwent QSM, 3D-T 1, diffusion MRI from Beijing Tiantan Hospital during June 2019 to June 2021. Susceptibility was compared among NMOSD patients with acute attack (ANMOSD), NMOSD patients in chronic phase (CNMOSD) and NC. The correlation between susceptibility in several brain regions and the cerebrospinal fluid levels of inflammatory makers were analyzed. Results:NMOSD patients showed different susceptibility in several brain regions including bilateral hippocampus, precuneus, right cuneus, putamen, superior parietal and inferior temporal ( P<0.001) and the posr-hoc showed it is higher than normal. Compared to CNMOSD patients, the ANMOSD patients showed increased susceptibility in the cuneus (0.009 ± 0.004 vs. 0.005 ± 0.004, P<0.05). There was significant positive correlations between susceptibility and CSF levels of sTREM2 which reflect the active of microglial cells ( r = 0.494, P<0.05). Conclusions:Despite the absence of supratentorial lesions on MRI, increased susceptibility suggests underlying inflammation in the cerebral cortex in both patients with ANMOSD and CNMOSD, and some of them are obviously related to inflammatory markers in CSF. QSM sequence can be used to explore the potential inflammation in NMOSD patients without obvious supratentorial lesions.

Association between circulating CD39+CD8+ T cells pre-chemoradiotherapy and prognosis in patients with nasopharyngeal carcinoma / 中华医学杂志(英文版)

BACKGROUND@#The mortality rate among patients with nasopharyngeal carcinoma (NPC) has improved significantly with the advent of chemoradiotherapy strategies. However, distant metastasis remains problematic. Tumor-specific reactivity in cancer patients has been detected exclusively in CD39+ T cells, particularly in CD39+CD103+ T cells. Circulating cancer-specific T cells are important for protecting against metastasis. This study aimed to evaluate the predictive value of circulating CD39+CD8+ T cells for metastasis in patients with NPC.@*METHODS@#We performed a cross-sectional, longitudinal study of 55 patients with newly diagnosed NPC of stage III-IVa. All patients were initially treated with standard combined chemoradiotherapy. Blood samples were obtained from 24 patients before and at 1 month and 6 months after treatment. T cell expression of CD39 and CD103, together with the markers of T cell exhaustion programmed death-1 (PD-1)/T cell immunoglobulin and mucin domain-containing protein 3 (Tim-3) and markers of cell differentiation CD27/CC-chemokine receptor 7/CD45RA, was examined by flow cytometry. The Wilcoxon rank-sum test analysis was used to analyze the differences between two groups. Kaplan-Meier analysis was used for analysis of progression-free survival (PFS).@*RESULTS@#The expression of circulating CD39+CD8+ and CD39+CD103+ CD8+ T cells was significantly higher in patients without distant metastasis (CD39+CD8+: 6.52% [1.24%, 12.58%] vs. 2.41% [0.58%, 5.31%], Z=-2.073, P=0.038 and CD39+CD103+CD8+: 0.72% [0.26%, 2.05%] vs. 0.26% [0.12%, 0.64%], Z=-2.313, P = 0.021). Most CD39+ T cells did not express PD-1 or Tim-3. Patients with high expression of CD39+CD103+CD8+ T cells had better PFS than patients with low expression (log rank value = 4.854, P = 0.028). CD39+CD8+ T cells were significantly elevated at 1-month post-treatment (10.02% [0.98%, 17.42%] vs. 5.91% [0.61%, 10.23%], Z = -2.943, P = 0.003). The percentage of advanced differentiated CD8+ T cells also increased at 1-month post-treatment compared with pre-treatment (33.10% [21.60%, 43.05%] vs. 21.00% [11.65%, 43.00%], Z = -2.155, P = 0.031). There was a significant correlation between elevated CD39+CD8+ T cells and increased effector memory T cells (intermediate stage: r = 0.469, P = 0.031; advanced stage: r = 0.508, P = 0.019).@*CONCLUSIONS@#CD39+CD8+ circulating T cells have preserved effector function, contributing to an improved prognosis and a reduced risk of metastasis among NPC patients. These cells may thus be a useful predictive marker for a better prognosis in patients with NPC.

Human Leukocyte Antigen-A Allele Distribution in Nasopharyngeal Carcinoma Patients Showing Anti-Melanoma-Associated Antigen A or Synovial Sarcoma X-2 T Cell Response in Blood / 中华医学杂志(英文版)

<p><b>Background</b>Development of innovative immunotherapy is imperative to improve the poor survival of the nasopharyngeal carcinoma (NPC) patients. In this study, we evaluated the T cell response to melanoma-associated antigen (MAGE)-A1, MAGE-A3, or synovial sarcoma X-2 (SSX-2) in the peripheral blood of treatment-naive NPC patients. The relationship of responses among the three proteins and the human leukocyte antigen (HLA)-A types were analyzed to provide evidence of designing novel therapy.</p><p><b>Methods</b>Sixty-one NPC patients admitted into the Tumor Hospital affiliated to the Xinjiang Medical University between March 2015 and July 2016 were enrolled. Mononuclear cells were isolated from the peripheral blood before any treatment. HLA-A alleles were typed with Sanger sequence-based typing technique. The T cell response to the MAGE-A1, MAGE-A3, or SSX-2 was evaluated with the Enzyme-Linked ImmunoSpot assay. Mann-Whitney U-test was used to compare the T cell responses from different groups. Spearman's rank correlation was used to analyze the relationship of T cell responses.</p><p><b>Results</b>HLA-A*02:01, A*02:07, and A*24:02 were the three most frequent alleles (18.9%, 12.3%, and 11.5%, respectively) among the 22 detected alleles. 31.1%, 19.7%, and 16.4% of the patients displayed MAGE-A1, MAGE-A3, or SSX-2-specific T cell response, respectively. The magnitudes of response to the three proteins were 32.5, 38.0, and 28.7 SFC/10 peripheral blood mononuclear cells, respectively. The T cell response against the three proteins correlated with each other to different extent. The percentage of A*02:01 and A*24:02 carriers were significantly higher in patients responding to any of the three proteins compared to the nonresponders.</p><p><b>Conclusion</b>MAGE-A1, MAGE-A3, or SSX-2-specific T cell responses were detectable in a subgroup of NPC patients, the frequency and magnitude of which were correlated.</p>

The sagittal morphological and clinical application study of nose in Chinese / 中华整形外科杂志

Objective@#The purpose of this study is to analyze the nasal morphological characteristics in Chinese adult, of Han nationality, by the measurements in sagittal plan and the proportionality between nose and facial structures, in order to provide aesthetic references for rhinoplasty, and individual surgical planning.@*Methods@#During 2017 November to December, 258 healthy Han Youth volunteers were included. Three-dimensional (3D) models of the facial characteristic information were collected using Artec 3D scanner, by standardized procedures. The nasal and facial distances and angulations were measured, based on predesigned facial landmarks. Thereafter, the proportions of above measurements were calculated.@*Results@#There was no significant difference between genders in absolute prominence. As for relative prominence, male nose is more prominent, resulted in a more stereoscopic facial profile. The nasal basal plane of both male and female, was more anterior than the infraorbital points, with 7% of the absolute degree of the infraorbital points. The range of the angle between the nasal basal plane and coronal plane was 2-4 degrees.@*Conclusions@#This study sets a database for the external nasal characteristics of the young adult in Chinese Han nationality, which could provide quantitative references for preoperative evaluation and individually surgical planning.

Purification and characterization of rat optic nerve head astrocytes / 眼科新进展

Objective To develop a set of methods for the culture and purification of astrocytes grown from explanted rat optic disc.Methods Rat optic disc and optic nerve were separated with anatomic microscopy and the blocks were cultivated primarily in culture flask with the medium containing DMEM/F-12.After digested by 2.5 g · L-1 trypsin,astrocytes were purified on the selective medium and passaged for two generations.Then cells were identified by immunofluorescent staining of glial fibrillary acidic protein (GFAP),neural cell adhesion molecule (NCAM) and Vimentin.Next,epidermal growth factor (EGF) was used to stimulate the purified cells for 24 h to observe their morphologic alteration.Finally,Western blot was used to detect the expression of GAFP,NCAM and Vimentin in the cells.Results When the tissue blocks were attached to the wall for 10 days,cells began to crawl out of the tissues and had different morphologies.After purified by the selective culture medium,satellite or anomalistic cells,possessing abundant cytoplasm,began to take a leading place.Immunofluorescent staining showed GFAP,NCAM and Vimentin were stained positively,and the purity of positive cells was above 90％.After stimulated by EGF,cells proliferated and the morphology changed;meanwhile,there was an increasing expression of GFAP,NCAM and Vimentin after stimulated by EGF when compared with the blank control group,and the difference was statistically significant (P ＜ 0.05).Conclusion Highly-purified astrocytes can be achieved by the culture of explanted lamina cribiosa and optic disc of rats in vitro.

The antidiabetic effect of jejunal exclusion surgery for T2DM rats / 中华内分泌外科杂志

Objective To study the curative effects of jejunal exclusion surgery for STZ-induced T2DM SD rats.Methods 60 SD rats were induced to be the T2DM SD rats by intraperitoneal injection of streptozotocini.As a result,55 T2DM SD rats were successfully acquired which were randomly divided into 3 groups,20 rats in the jejunal exclusion group (A),20 rats in the sham operation group (B) and 15 rats in the control group (C).Jejunal exclusion surgery was performed in group A,jejunojejunostomy was performed in group B,and group C were fed normally.The body weight,fasting blood glucose,fasting plasma insuhn level and GLP-1 level were measured before operation and at the 1st,2rid,4th,8th and 16th week after operation.Results As compared with that before operation and that of the control group,the body weight in group A markedly declined at the 2nd,4th,8th and 16th week (352.14±9.00,342.84±8.90,336.64±10.26,330.34±9.12,P＜0.05).The fasting plasma glucose levels in group A markedly declined at the 2nd,4th,8th and 16th week (14.62±1.10,12.12±1.38,8.75± 1.06,7.55±1.00,P＜0.05).The fasting plasma insulin level in group A was maikedly increased at the 2nd,4th,8th and 16th week (14.62±3.10,16.12±3.38,17.75±4.06,17.55±3.10,P＜0.05).GLP-1 level in group A was markedly increased at the 1st,2nd,4th,8th and 16th week (11.02±0.85,14.42±1.18,16.02±1.59,17.62±1.02,18.12±0.71,P＜0.05).Conclusions The jejunal exclusion surgery is effective in controlling blood glucose,which is an ideal and lasting method.This surgery has also showed influence on body weight.

Diagnostic Value of DNA Fragmentation Index and Acrosin Activity in Male Infertility / 中山大学学报(医学科学版)

[Objective]We aimed to explore the diagnostic value of DNA fragmentation index(DFI)and acrosin activi-ty in male infertility.[Methods]Nine hundred and two semen samples were collected from patients and assessed for the DNA fragmentation index by sperm chromatin dispersion test,acrosin activity,as well as standard sperm parameters according to the WHO criteria. Statistical analysis was performed with SPSS.[Results]Statistically significant differences were observed in age,sperm concentration,total motility,progressive rate and acrosin activity among different group of sperm DNA dam-age(≤10%,11~20%,21~30%,≥31%).Sperm acrosin activity also showed difference in sperm concentration,total num-ber,total motility,progressive rate,normal morphology rate,teratozoospermia index(TZI)and sperm DFI.The DNA frag-mentation rate and sperm concentration,sperm motility,forward motility rate,total sperm count and acrosin activity was neg-atively correlated,while it is negative correlatd with TZI. Acrosin activity and sperm concentration,sperm motility,forward motility rate,sperm count and normal morphology rate was positively correlated,while it is negative correlated with the ab-normal rate of head,sperm deformity index,DNA fragmentation rate.[Conclusion]Sperm DNA damage and acrosin activity could partly reflect the quality of sperm. Moreover,sperm DFI maypredict the sperm motility part while the acrosin activity more likely related to sperm morphology.

Chemical constituents from flowers of Gardenia jasminoides / 中草药

Objective: To study the chemical constituents from the flowers of Gardenia jasminoides. Methods: The compounds were isolated by extensive chromatographic methods, including macroporous adsorption resin, silica gel column chromatography, and HPLC method. Their structures were elucidated on the basis of physiochemical properities and spectroscopic data. Results: Ten compounds were obtained and identified as kaempferol 3-O-β-D-glucopyranoside (1), kaempferol 3-O-β-D-galactopyranoside (2), kaempferol 3-O- robinobioside (3), kaempferol 3-O-rutinoside (4), corchoionoside C (5), (E)-p-hydroxycinnamic acid methyl ester (6), vanillin (7), caffeic acid (8), protocatechuic acid (9), and β-sitosterol (10). Among them, compounds 1-4 belong to flavonoid glucosides. Conclusion: Compounds 2, 3, and 5-7 are first isolated from the plants of Gardenia Ellis and compounds 1, 4, 8 and 9 are first isolated from the flowers of G. jasminoides.

Complete mesocolic excision combined with arterial infusion and intra-peritoneal interstitial sustained-release chemotherapies for colorectal cancer / 中国肿瘤临床

Objective:To investigate the safety and effect of complete mesocolie excision (CME) combined with arterial infusion chemotherapy (AIC) and intra-peritoneal interstitial sustained-release chemotherapy (IPISRC). Methods:A total of 104 patients were classified under the experimental group and underwent CME combined with AIC and IPISRC. The other 98 patients were classified un-der the control group and only received radical surgery. Pre-and post-operative blood routine examinations, as well as liver and kidney function tests, were conducted for both groups. Post-operative adverse reactions and incidence of complications were recorded. Cancer and para-neoplastic tissues were sampled in experimental group. The post-surgery 5-fluorouracil (5-FU) concentration in the drainage fluid as well as those in the peripheral blood , were determined. Three-year follow-ups were conducted, during which the local recur-rence rate, liver metastasis, progression-free survival rate, and total survival rate were recorded. Results: No significant differences were found in the white blood cell count, hemoglobin count, liver and renal functions of the patients before and after the surgery, and rate of adverse reaction and complications between the two groups after surgery (P>0.05). In experimental group , the 5-FU concentra-tion was significantly higher in the cancer tissues than in the para-neoplastic tissues . The 5-FU concentration in experimental group was also significantly higher in the intra-peritoneal drainage liquid and reached its peak in the peripheral blood on day 3 post-surgery . Local recurrence and liver metastasis rates were significantly lower in experimental group than those in control group, whereas the pro-gression-free and three-year overall survival rates were significantly higher in experimental group than in control group (P<0.05). Con-clusion:The tharepy of pations of experimental goup is safe and effective. This method significantly improves the progression-free and three-year survival rates of the patients as well as significantly reduces the local recurrence and liver metastasis rates of colon cancer.

Urinary bladder malignant paraganglioma with vertebral metastasis: a case report with literature review / 癌症

Paraganglioma is a rare neuroendocrine neoplasm observed in patients of all ages, with an estimated incidence of 3/1,000,000 population. It has long been recognized that some cases are familial. The majority of these tumors are benign, and the only absolute criterion for malignancy is the presence of metastases at sites where chromaffin tissue is not usually found. Some tumors show gross local invasion and recurrence, which may indeed kill the patient, but this does not necessarily associate with metastatic potential. Here, we report a case of vertebral metastatic paraganglioma that occurred 19 months after the patient had undergone partial cystectomy for urinary bladder paraganglioma. We believe this to be a rarely reported bone metastasis of paraganglioma arising originally within the urinary bladder. In this report, we also provide a summary of the general characteristics of this disease, together with progress in diagnosis, treatment, and prognosis.

Anti-Müllerian hormone in male serum and prediction of the outcomes of assisted reproductive technology / 中华男科学杂志

<p><b>OBJECTIVE</b>To evaluate male serum anti-Müllerian hormone (AMH) in assessing semen quality and predicting the pregnancy outcomes of assisted reproductive technology (ART).</p><p><b>METHODS</b>A total of 103 male patients under ICSI were allotted to Groups A (normal sperm concentration control, n = 29), B (oligospermia, n = 27), C (obstructive azoospermia, n = 29) and D (non-obstructive azoospermia, n = 18). The contents of serum AMH and other related sexual hormones were determined by ELISA, and their correlations were analyzed with the seminal quality on the day of semen collection and with the pregnancy outcomes after ICSI.</p><p><b>RESULTS</b>The contents of male serum AMH were (5.03 +/- 0.44), (3.70 +/- 0.44), (5.39 +/- 0.71) and (7.31 +/- 1.64) pmol/L, respectively, in Groups A, B, C and D, with no statistically significant differences among the four groups (F = 2.02, P > 0.05). The egg fertilization rate of the 103 couples was (76.13 +/- 23.66) %, not significantly correlated with the male serum AMH level (P > 0.05). The contents of male serum AMH in the pregnancy and non-pregnancy groups were (6.19 +/- 1.05) and (4.72 +/- 1.64) pmol/L, respectively, with no significant difference (t = 1.281, P > 0.05).</p><p><b>CONCLUSION</b>The level of male serum AMH can neither reflect spermatogenesis of men nor predict the egg fertilization rate and pregnancy outcomes after ICSI, and therefore cannot be used alone as a serological predictive marker of ICSI outcomes.</p>

Clinical discussion on the pathological diagnosis of high-grade intraepithelial neoplasia in gastric biopsy / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To evaluate the value and inadequacy in clinical practice of the concept of gastric high-grade intraepithelial neoplasia (HIN).</p><p><b>METHODS</b>Forty-five cases with gastric HIN diagnosed by the esophagogastroduodenoscopy (EGD) biopsy were treated from 2003 to 2009. The clinical and histopathological data were analyzed retrospectively.</p><p><b>RESULTS</b>Radical surgeries were successfully performed on all the patients, among whom 33 underwent distal subtotal gastrectomy, 3 proximal partial gastrectomy, 7 total gastrectomy, and 2 endoscopic mucosal resection. In postoperative pathological examination, only 15 cases (33.3%) were HIN, while 14 cases (31.1%) were found to be early gastric cancers, and 16 (35.6%) were advanced cancers. Twelve(40.0%) out of 30 cancers had regional lymph nodes metastasis. When the maximum diameter of the HIN lesion was greater than 3.0 cm, or when ulcer or the features of poorly-differentiated carcinoma or signet-ring cell carcinoma were present in preoperative biopsy, the likelihood of cancer in postoperative pathological examination was higher (P<0.05), and when malignancy was confirmed, the presence of the features above was associated with lymph nodes metastasis and advanced cancer.</p><p><b>CONCLUSIONS</b>Carcinoma is identified in a large proportion of patients with gastric HIN by the EGD biopsy. Lymph nodes metastasis or advanced cancer may be detected in these cases. Cautions must be taken when the new concept of HIN is widely used for diagnosing gastric lesion. Radical resection should be considered when the maximum diameter of the HIN lesion is greater than 3.0 cm, or when ulcer, or the feature of poorly-differentiated carcinoma or signet-ring cell carcinoma are present in the EGD biopsy.</p>

Comparison of changes in body composition during puberty development of obese and normal-weight children in China / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To compare the changes in body composition, including fat mass index (FMI) and fat free mass index (FFMI) during puberty development of obese and normal-weight children in China, and to explore the effect of age and gender on body composition.</p><p><b>METHODS</b>A total of 356 children at the age of 7-15 years were enrolled in this study. Body composition of 10 normal-weight and obese children in each age group was measured by dual-energy x-ray absorptiometry (DEXA). FFMI and FMI were calculated according to the following formula: FFMI (kg x m(-2)) = FFM(kg) / height2 (m2) and FMI (kg x m(-2)) = FM (kg) / height2 (m2).</p><p><b>RESULTS</b>The fat mass and fat free mass of obese children were significantly higher than those of normal-weight children (P < 0.05). The FMI and FFMI of obese children increased significantly with age and were higher than those of the same sex, gender, and age normal-weight children (P < 0.05).</p><p><b>CONCLUSION</b>The levels of fat mass, fat free mass, FMI, and FFMI are different in obese and normal-weight children, and gender effects are significant in boys having higher levels of these indicators than in girls. FFMI and FMI can be used as monitoring indexes in weight control of obese children.</p>

Effect of Cholecystokinine on Nervous System / 中国普外基础与临床杂志

Objective To review the biologic characteristics and biologic effect of cholecystokinine (CCK) on the central nervous system. Methods The literatures of recent years on research advancement of cholecystokinine as neurotransmitters/peptides in signal transduction, neuron protection and pain management in the central nervous system are reviewed. Results CCK possesses the ability to suppress the convulsant effects of convulsants. CCK8 is able to reduce the neural damage caused and delay the neural aging. CCK antagonists play an important role in human pain transduction. Conclusion CCK has been proven to be one of the richest neurotransmitters/neuropeptides as well as an important signal factor in the brain, and its important biologic effect is being confirmed.

Mutation research on Q23L and Q23LG272E in phytase derivated from Aspergillus fumigatus / 生物工程学报

Aspergillus fumigatus wild-type phytase has many favorable properties, such as a good thermorstability and a broad pH optimum. However, the specific activity of the enzyme is relative low. A. fumigatus Q23L phytase resulted in a remarkable increase in specific activity around pH4.5 - 7.0, but the pH stability of Q23L was lower than A. fumigatus wild-type phytase. To increase the pH stability of Q23L, the mutant Q23LG272E was constructed by site-directed mutagenesis with PCR. The gene of A. fumigatus wild-type phytase and the mutant genes encoding the Q23LG272E and the Q23L were correctly expressed in Pichia pastoris GS115. Enzymes were purified and their enzymatic properties were determined. The results revealed that the specific activity of the Q23L improved remarkably, which increased from 51 u/mg of the wild type to 109 u/mg at pH5.5. Meanwhile, the pH stability of Q23L, decreased evidently, especially from pH3.0 to pH4.0.The pH stability of Q23LG272E in pH3.0 - 4.5 and pH6.5 - 7.0 has been improved compared with Q23L. The specific activity of Q23LG272E basically maintained at the level of Q23L. Analysis of 3-D structure and sequence similarity were used to reveal the presumable factors influencing the enzymatic properties of Q23LG272E, and discussion for the relationship between structure and function of phytase was given.

Hydrophobic interaction between beta-sheet B1 and B2 in xylanase XYNB influencing the enzyme thermostability / 生物工程学报

A homology modeling of xylanase XYNB from Streptomyces olivaceoviridis A1 was made by Swiss-Model. The hydrophobic Interaction between beta-sheet B1 and B2 in the tertiary structure model of XYNB was compared with other thermophilic xylanase. A T11Y mutation was introduced in XYNB by site-dirrected mutagenesis to improve the thermostability of the enzyme. The XYNB and mutant xylanase (XYNB') expressed in Pichia pastoris were purified and their enzymatic properties were determined. The result revealed that the thermostability of XYNB' was obviously higher than that of XYNB. The optimal temperature of XYNB' for its activity was 60 degrees C, similar to XYNB. But, compare to XYNB, the optimal pH value, the Km value and the specific activity of XYNB' had also been changed. The research results suggested that the aromatic interaction between beta-sheet B1 and B2 in xylanase should increase enzyme thermostability. The mutant xylanase XYNB' is a good material for further research in the relationship between structure and function of xylanase.

Expression of acidophilic alpha-amylase from Alicyclobacillus acidocaldarius / 生物工程学报

The alpha-amylase (EC 3.2.1.1) from the Gram-positive Alicyclobacillus acidocaldarius was one kind of thermoacidophilic enzyme, with optimal temperature and pH of 75 degrees C and 3, respectively. The nucleotide sequence of the gene amy was cloned by PCR. The gene amy was 3901bp long, comprising one open reading frame encoding a polypeptide of 1301 amino acids. The calculated molecular weight of the alpha-amylase AMY was about 140kD. The gene amy was expressed in E. coli BL21 (DE3) and Pichia pastoris respectively, and both of the cloned proteins had bioactivity. The activity of amylase expressed in P. pastoris was further testified by amylase activity staining. The alpha-amylase expressed in P. pastoris had been purified and characterized. The apparent molecular weight of that was about 160kD according to SDS-PAGE. The optimum of pH for the enzyme was pH 3.2 as the native enzyme was; but the optimum of temperature was 65 degrees C and a little lower than that of the native enzyme. Above 50% of relative activity remained after incubation for 30 minutes in 70 degrees C. So the enzyme expressed by P. pastoris was also thermoacidophilic. Moreover some sequence was cloned by PCR, which ranged from + 1174 bp to + 3288 bp in the gene amy, encoding 705 amino acids with the calculated molecular weight of 79kD. The truncated gene amy' was expressed in E. coli BL21 (DE3) induced by 1 mmol/L IPTG, and the expressed enzyme also retained alpha-amylase activity.

Overexpression of Escherchia coli phytase with high specific activity / 生物工程学报

High-level expression of phytase with high specific activity is an effective way to improve phytase fermentation potency and reduce its production cost. The gene appA encoding Escherchia coli phytase AppA with high specific activity was modified and artificially synthesized according to the bias in codon choice of the high expression gene in Pichia pastoris without changing the amino acid sequence of the AppA. The modified gene, appA-m, was inserted in the Pichia pastoris expression vector pPIC9, then introduced into the host Pichia pastoris by electroporation. The Pichia pastoris recombinants for phytase overexpression were screened by enzyme activity analysis and SDS-PAGE. The result of Southern blotting analysis of the recombinant yeast indicated that only one copy of the appA-m gene was integrated into the genome of Pichia pastoris. The result of Northern analysis of the recombinant yeast showed that the modified gene was effectively transcribed. SDS-PAGE analysis of the phytase expressed in Pichia pastoris revealed that the phytase was overexpressed and secreted into the medium supernatant. There are three phytase proteins with apparent molecular weight in approximately 50kD, 52kD and 54kD respectively in the media, which are larger in the size than the native phytase from E. coli. The results of N-terminal sequecing and deglycosylation of the expressed phytase in Pichia pastoris proved that the expressed phytase were glycosylated protein with different glycosylation degree. The expressed phytase Pichia pastoris shared similar pH and temperature optima to those of the natural phytase from E. coli and had highly resistant to pepsin digestion. In 5-L fermentor, after induced by 0.5% methanol for 120 h, the expression level of phytase protein was 2.5 mg/mL, and the phytase activity (fermentation potency) exceeded 7.5 x 10(6) IU/mL, which was the highest among those of all kinds of recombinant strains reported now.

Analysis on Introducing of Complementary Food and Its Influencing Factors in Shijingshan District in Beijing / 实用儿科临床杂志

Objective To explore the problems in the introducing of complementary food in infants and provide a guidance for cli nical practice.Methods The questionnaire survey was carried out by childhood health doctors in mothers or caregivers on fixed outpatient health care day. The data of survey was entered into computer and analyzed with SPSS 11.5 software.Results 1.Earlier (

Expression of xylanase gene xynA from Streptomyces olivaceoviridis A1 in Escherichia coli and Pichia pastoris / 生物工程学报

The gene xynA encoding xylanase was cloned from Streptomyces olivaceoviridis A1. The xynA with and without origin signal peptide sequence were fused behind pel B signal peptide in the plasmid pET-22b(+) respectively, then transfered into the host E. coli. The xylanase expressed in E. coli had normal bioactivity. Further, the xynA without origin signal peptide sequence was cloned into the plasmid pPIC9 under the control of AOX1 promoter and introduced into the host Pichia pastoris by electroporation. The results of SDS-PAGE and activity assay of the xylanase expressed by recombinant P. pastoris showed that the xynA had been overexpressed and secreted, and the xylanase expressed had normal bioactivity. The expression level of xylanase in recombinant P. pastoris exceeded 0.2mg/mL in shake culture.