Dissection borders of laparoscopic lower mediastinal lymphadenectomy for adenocarcinoma of esophagogastric junction and the quality control / 中华胃肠外科杂志

The lower mediastinal lymphadenectomy is indicated for adenocarcinoma of esophagogastric junction (AEG), while the laparoscopic procedure shows some advantages. According to previous studies and results of IDEAL phase 2a study in our institute, the following structures are recommended as the dissection borders: the upper (cranial) is inferior wall of pericardium and pulmonary ligament; the lower (caudal) is diaphragm hiatus (esophagogastric junction); the front (ventral) is anterior inferior wall of pericardium and diaphragm; the back (dorsal) is anterior wall of aorta; the lateral is mediastinal pleura. The standard of quality control is still under investigation.

Advances in peptidomimetic inhibitors of coronavirus main protease / 药学学报

Coronavirus (CoVs) is a widespread pathogen that can infect humans and animals to cause serious acute and chronic respiratory diseases. Among them, SARS-CoV broke out in 2003, MERS-CoV was discovered and spread widely in 2012, and SARS-CoV-2 emerged at the end of 2019. They all belong to β-coronavirus. Peptidomimetic inhibitors targeting coronavirus main proteases (Mpro, 3CLpro) have attracted much attention because of their broad spectrum and strong antiviral efficacy. In this review, peptidomimetic inhibitors of coronavirus main protease were classified and summarized according to the different "warheads" in design strategy. And also, the molecular structures, biological activity and design ideas of the inhibitors were analyzed and discussed, which is aimed to provide useful reference for further design and development of coronavirus inhibitors.

Research Progress of Signaling Pathways Related to Treatment of Colorectal Cancer with Chinese Medicine： A Review / 中国实验方剂学杂志

The occurrence and development of colorectal cancer as a complex disease involves the abnormality of multiple signaling pathways. Chinese medicine regulates a variety of biological processes such as tumor cell differentiation， cell proliferation， apoptosis， cell metastasis， cell cycle， and tumor angiogenesis to prevent the occurrence of colorectal cancer （inflammation-cancer transformation）， tumor metastasis （common metastases of colorectal cancer include liver metastasis， lung metastasis， bone metastasis， and lymphatic metastasis）， and multidrug resistance induced by chemotherapy， treat primary tumors， and mitigate the toxic and side effects of chemotherapy. The pathways of Chinese medicine in the treatment of colorectal cancer have been intensively studied. The available studies have demonstrated that Patrinia villosa Juss and Pien Tze Huang can regulate the Notch pathway to inhibit the growth of colorectal cancer cells. Curcumin and Quyu Jiedu decoction regulate Hippo pathway to inhibit the survival， proliferation， invasion， and migration of colorectal cancer cells. Kujin tea and luteolin suppress the proliferation of colorectal cancer cells and protect intestinal barrier by regulating Kelch-like epichlorohydrin-associated protein-1 （Keap1）/nuclear factor E2-related factor 2 （Nrf2）/antioxidant response element （ARE） pathway. Icariin and ginkgolide C can regulate hepatocyte growth factor （HGF）/cellular-mesenchymal to epithelial transition factor （c-Met） pathway to induce apoptosis of colorectal cancer cells and prevent liver metastasis of colorectal cancer. Verbascoside and apigenin regulate p53 protein to promote apoptosis of colorectal cancer cells， reverse thymidylate synthase （TS）， and alleviate the multidrug resistance of colorectal cancer. Resveratrol and lycopene regulate insulin-like growth factor （IGF）/insulin-like growth factor receptor 1 （IGF1R） pathway to inhibit cancer cell metastasis and prolong disease-free survival. Cordycepin and Galla Chinensis water extract activate AMP-activated protein kinase （AMPK） pathway to inhibit the migration and invasion of cancer cells as well as the lung metastasis of colorectal cancer. The above summary aims to provide reference for the in-depth research on the treatment of colorectal cancer with Chinese medicine and inspire new research ideas.

Effect of Modified Simiaosan on Inflammatory Factors and Neuropeptide Substances of Patients with Synovitis of Knee Joint and Damp-heat Obstruction Collateral Syndrome / 中国实验方剂学杂志

Objective::To observe the clinical efficacy of modified Simiaosan on synovitis of knee joint with damp-heat obstruction collateral syndrome and the effect on inflammatory factors and neuropeptide substances in synovial fluid. Method::One hundred and thirty-five patients were randomly divided into control group(67 cases) and observation group(68 cases) by random number table. Patients' intra-articular effusion was drawn out. Triamcinolone acetonide was injected into arthrosis for 2 times, 1 time/week, and aceclofenac sustained-release tablets were given for 4 weeks, 0.2 g/time, 1 time/day. In addition to the therapy of control group, patients in observation group were also given modified Simiaosan for 4 weeks, 1 dose/day. Before and after treatment, pain, swelling of knee joint and were scored, Western Ontario and McMaster University (WOMAC) were adopted for scoring knee score, and damp-heat obstruction syndrome and local signs of knee joint were also assessed. And levels of interleukin-1 beta (IL-1 beta), IL-6, tumor necrosis factor-alpha (TNF-alpha), hypersensitive C-reactive protein (hs-CRP), substance P (SP), calcitonin gene-related peptide (CGRP), neuropeptide Y (NPY) and vasoactive intestinal peptide (VIP) were detected. Result::After treatment, scores of pain and swelling of knee joint in observation group were lower than those in control group (P<0.01). Scores of WOMAC, the total score, integral of damp-heat obstruction collateral syndrome, knee flexion-extension range score and floating patella test were all lower than those in control group (P<0.01). And levels of IL-1β, IL-6, TNF-α, hs-CRP, SP, CGRP, NPY and VIP were all lower than those in control group (P<0.01). Analyzed by rank sum test, the clinical efficacy in observation group was better than those in control group (Z=2.089, P<0.05). Conclusion::Modified Simiaosan can significantly alleviate pain and swelling symptoms, promote the recovery of knee joint function, and inhibit the expressions of proinflammatory factors and neuropeptides in synovial fluid, with a better clinical efficacy.

Influence of preparation height and cement space on the fit and retention of computer aided design/computer aided manufacturing zirconia crown / 华西口腔医学杂志

OBJECTIVE@#To investigate the effects of preparation height and cement space on the fit and retention of computer aided design (CAD)/computer aided manufacturing (CAM) zirconia crown, and to provide reference for the clinical design and fabrication of CAD/CAM crowns.@*METHODS@#3D printing system was used to fabricate resin abutment teeth with convergence angle of 2° and height of 1-3 mm. The models' optical impressions were collected by the three-shape scanner. Then, the cement spaces were set by Cradle CAD/CAM system at 10-50 μm to create an all-ceramic zirconia crown. The fit of the crowns was measured by using silicone rubber interstitial impression method. The retention of the crowns was measured by pull-off test with uniaxial tensile force after the crown was bonded. The data were analyzed by SPSS 22.0 soft-ware.@*RESULTS@#When the preparation height was fixed, the fitness values of different cement space groups have statistical difference (P0.05). The fitness values of different preparation height groups have no statistical difference (P>0.05), and the retention values of different preparation height groups have statistical difference (P0.05).@*CONCLUSIONS@#When cradle CAD/CAM system is used to create a full crown in the clinic, the preparation height should be set to more than 3 mm, and the cement space should be set at 30 μm.

Effect of MicroRNA-199 on Proliferation and Migration of Gastric Carcinoma Cells / 中国医学科学院学报

Objective To detect the expression of microRNA(miR)-199 in gastric carcinoma tissues and cell lines, and further explore the effect and molecular mechanism of miR-199 on the proliferation and migration of gastric carcinoma cell lines. Methods Reverse transcriptase-polymerse chain reaction was used to detect the expression of miR-199 in gastric carcinoma and adjacent normal tissue obtained from 51 patients and in gastric carcinoma cell lines and human gastric epithelial cell line GES-1. The gastric carcinoma cell lines over-expressing and low-expressing miR-199 were established to detect their proliferation and migration abilities. Dual-luciferase reporter assay was performed to detect the regulatory effect of miR-199 on the 3'untranslated region of TBL1XR1. Western blot was used to explore the miR-199-related mechanism. Results The relative expression of miR-199 in gastric carcinoma tissues was significantly lower than that in the adjacent normal tissue (0.2635±0.0303 vs. 1.6700±0.9613, t=13.95, P<0.001). The relative expressions of miR-199 in gastric carcinoma cell lines AGS (0.81, t=9.13, P<0.001), SGC-7901 (0.83, t=8.88, P<0.001), MKN28 (0.58, t=10.80, P<0.001), KATO-3 (0.60, t=10.31, P<0.001), MKN-45 (0.27, t=13.10, P<0.001) were significantly lower than that in the normal gastric cell line GES-1 (2.1). In miR-199 over-expressed cell lines, the cell proliferation and migration significantly decreased as compared with the control group of gastric carcinoma cells (731±13 vs. 345±18, t=24.90, P<0.001), and in miR-199 low-expressed group, the cell proliferation and migration increased compared with the control group of gastric carcinoma cells (257±16 vs. 657±8, t=32.59, P<0.001). Dual-luciferase reporter assay proved that miR-199 directly targeted on the 3' untranslated region of TBL1XR1. Western blot analysis showed that miR-199 inhibited the expression of TBL1XR1. Conclusion The over-expression of miR-199 in gastric carcinoma is associated with the decreased ability of proliferation and migration of gastric carcinoma cells by targeting TBL1XR1.

Comparative analysis of rapamycin biosynthesis clusters between Actinoplanes sp. N902-109 and Streptomyces hygroscopicus ATCC29253 / 中国天然药物

The present study was designed to identify the difference between two rapamycin biosynthetic gene clusters from Streptomyces hygroscopicus ATCC29253 and Actinoplanes sp. N902-109 by comparing the sequence and organization of the gene clusters. The biosynthetic gene cluster for rapamycin in Streptomyces hygroscopicus ATCC29253 was reported in 1995. The second rapamycin producer, Actinoplanes sp. N902-109, which was isolated in 1995, could produce more rapamycin than Streptomyces hygroscopicus ATCC29253. The genomic map of Actinoplanes sp. N902-109 has been elucidated in our laboratory. Two gene clusters were compared using the online software anti-SMASH, Glimmer 3.02 and Subsystem Technology (RAST). Comparative analysis revealed that the organization of the multifunctional polyketide synthases (PKS) genes: RapA, RapB, RapC, and NRPS-like RapP were identical in the two clusters. The genes responsible for precursor synthesis and macrolactone modification flanked the PKS core region in N902-109, while the homologs of those genes located downstream of the PKS core region in ATCC29253. Besides, no homolog of the gene encoding a putative type II thioesterase that may serve as a PKS "editing" enzyme accounted for over-production of rapamycin in N902-109, was found in ATCC29253. Furthermore, no homologs of genes rapQ (encoding a methyltransferase) and rapG in N902-109 were found in ATCC29253, however, an extra rapM gene encoding methyltransferase was discovered in ATCC29253. Two rapamycin biosynthetic gene clusters displayed overall high homology as well as some differences in gene organization and functions.

Application of perioperative imatinib mesylate therapy in initial resectable primary local advanced gastrointestinal stromal tumor at intermediate or high risk / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To evaluate the effect of perioperative imatinib mesylate (IM) therapy for patients with initial resectable primary local advanced gastrointestinal stromal tumor (GIST) at intermediate or high risk on R0 resection rate and the prognosis.</p><p><b>METHODS</b>Forty-eight above GIST patients between December 2001 and February 2012 were divided into 2 groups: neoadjuvant group (15 cases, pre- and post-operation IM therapy) and adjuvant group (33 cases, post-operative IM therapy). R0 resection rate, complication rate, disease-free survival (DFS) and overall survival (OS) were analyzed and compared between the two groups.</p><p><b>RESULTS</b>The maximal tumor diameter and average tumor diameter were larger in neoadjuvant group as compared to adjuvant group (11.2 cm vs. 7.7 cm, P=0.005; 9.1 cm vs. 6.2 cm, P=0.014). The response rate of preoperative IM therapy was 93.3% (14/15). The R0 resection rate was 86.7% and 84.8% (P=1.000), and the complication rate was 13.3% and 9.1% (P=0.642) in neoadjuvant and adjuvant group respectively. The 3-year DFS was 55% and 41% (P=0.935), and 5-year OS was 83% and 75% (P=0.766) in neoadjuvant and adjuvant group respectively.</p><p><b>CONCLUSIONS</b>Resectable primary local advanced GIST at intermediate or high risk with larger tumor diameter receiving perioperative IM therapy can achieve the same R0 resection rate, complication rate, DFS and OS as the GIST with smaller diameter receiving operation first. Perioperative IM therapy has potential advantage.</p>

Application of the island flap at the dorsum of the middle phalange with the pedicel of the digital proper artery / 中华整形外科杂志

<p><b>OBJECTIVE</b>To explore a method for the treatment of the skin defects at the distal phalanges of 2-5th fingers.</p><p><b>METHODS</b>The island flap at the dorsum of the middle phalange was designed with the pedicle of dorsal branches from the digital proper artery. When the flap was used to repair defect at finger pulp, the dorsal branch of the digital proper nerve in the flap was kept to be anastomosed to the digital proper nerve at the recipient finger. From Feb. 2005 to May. 2010, 54 cases with skin defects at the distal phalanges of 61 fingers were treated with the flap, including 35 defects at finger pulp and 26 defects at finger tip.</p><p><b>RESULTS</b>The maximum size of defects and flaps was 2.2 cm x 2.5 cm and 2.4 cm x 2.7 cm, respectively. 61 flaps survived completely. Blister was happened in 3 flaps 2 days after operation, which healed spontaneously without necrosis. 54 cases were followed up for 5 to 22 months (average, 11 months). The flaps had good texture and color match with normal sensation (grade S4). The 2-point discrimination distance was 6-9 mm. The interphalangeal joint had normal movement.</p><p><b>CONCLUSIONS</b>The island flap at the dorsum of the middle phalange is an ideal method for the skin defect at the distal phalange of finger.</p>

Analysis of splenic hilar lymph node metastasis in advanced gastric cancer and dissection techniques / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To study the status of splenic hilar lymph nodes(No.4sa, No.10 or No.11d lymph nodes) metastasis and to investigate the proper dissection technique in patients with advanced gastric cancer.</p><p><b>METHODS</b>A retrospective study was performed to investigate 590 patients who underwent D2 curative proximal or total gastrectomy for gastric carcinoma from January 2006 to December 2009. Clinicopathological factors such as sex, age, location of the primary tumor, tumor sizes, gross type, depth of invasion, microscopic classification, neoadjuvant chemotherapy and the metastasis of adjacent lymph node were analyzed with univariate and multivariate analysis. Influence of combined splenectomy or pancreatectomy on lymph node dissection was also investigated.</p><p><b>RESULTS</b>The overall ratio of metastatic lymph node(positive lymph nodes/lymph nodes harvested) in the splenic hilum was 17.5%(99/565). The positive rates of No.4sa, No.10, No.11d lymph nodes were 17.8% (41/230), 13.9%(29/209), and 22.8%(29/127), respectively. A total of 7.1%(42/590) of the patients had lymph node metastasis in the splenic hilum. Multivariable logistic regression analysis showed that age, tumor size, depth of tumor invasion, positive metastasis of No.4sb lymph node were independent risk factors for lymph node metastasis in the splenic hilum region. When comparing patients undergoing combined splenectomy or pancreatectomy(n=23) and those who did not undergo combined organ resection (n=553), the ratios of metastatic lymph node in the splenic hilum were 14.8%(4/27) and 17.2%(91/527), respectively, and the difference was not statistically significant(P>0.05). The postoperative complication rates were 26.1%(6/23) and 5.4%(30/553), respectively, and the difference was statistically significant(P<0.05). The operative mortality rates were 4.3% and 0.9%, respectively, and the difference was not statistically significant(P>0.05).</p><p><b>CONCLUSIONS</b>Metastasis to lymph nodes in the splenic hilum region in patients with gastric cancer possesses a certain pattern, and it is associated with tumor location, size, depth of invasion, and metastasis in No.4sb. Combined resection of the spleen or pancreas does not result in increased number of harvested lymph nodes or positive lymph nodes, yet is associated with higher complication rate. Therefore, combined organ resection should be meticulous.</p>

Maxillary sinus augmentation with simultaneous implantation using guided bone regeneration / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the effect of new bone formation in sinus augmentation with guided bone regeneration (GBR) using collagen membranes.</p><p><b>METHODS</b>The first maxillary molars of 18 adult female Beagle dogs were extracted and the sinus floors of both sides were lifted with simultaneous implantation. A combination of autografts and Bio-Oss in a 2:1 ratio was placed in the space under the membrane. On the experimental side in each dog, the collagen membrane was folded at the lateral osteotomy window, the apex of the implants and a certain part of palatal bone. On the contralateral control side, the collagen membrane only covered the osteotomy window. Six animals were sacrificed at 4, 12, and 24 weeks respectively after surgery. Gross observation, biomechanical testing and histological examinations were performed.</p><p><b>RESULTS</b>The translocation of grafted materials and bone absorption were found on the top of implants in the control side, and the grafted materials kept original shape at the experimental side at 4th week. The granule of Bio-oss absorbed obviously at 12th and 24th week. The pull-out force increased with time. At 24th week, the force of pull out was 558.1 ± 37.4 N at the study side, and 471.4 ± 31.5 N at the control side. There was a significant difference in the pull-out force was noted between the two groups (P < 0.01). Histological examination showed new bone formation on the sinus floor, and the grafted materials gradually reduced with time</p><p><b>CONCLUSIONS</b>GBR with the enfolded-coverage of the membrane can effectively decrease absorption of the grafted materialon the apical surface of implants and stimulate new bone formation in the sinus augmentation.</p>

Analysis on the changing trend of mortality rate and spectrum regarding causes of death in the last recent 30 years in Hunan province / 中华流行病学杂志

Objective To investigate the changing trend of mortality and the spectrum regarding causes of death in the population of Hunan, and to analyze the health-related major diseases.Methods With retrospective study method, a sample survey on causes of death and the related information was carried out from 2004 to 2005 among the residents in Hunan province. Results were compared with the data from a retrospective survey on causes of death in Hunan during 1973-1975 and 1990-1992, respectively. Results The crude mortality rates and the standardized mortality ratios (SMR) of the reisidents in Hunan were 901.59/100 000 and 865.14/100 000 during the period of 1973-1975 while 588.64/100 000 and 537.42/100 000 druing the period of 1990-1992, and 608.27/100 000 and 413.67/100 000 during the period of 2004-2005, respectively. During the past 30 years, the SMR of the residents in Hunan decreased by 52.18% and the descending range from the rural areas was more than that of the urban areas, and higher in females than in males. The death proportion of infectious diseases, maternal and perinatal diseases, nutritional deficiencies decreased significantly (P＜0.01), but the death proportion of chronic non-communicable diseases increased significantly (P＜0.01). The changing ranges of the former two proportions were both larger in the rural areas than those in the urban areas. The highest proportions of deaths due to injury and poisoning during the past 30 years were both seen in the 5 year olds, followed by the age groups of 25 year olds (P＜0.01). During the period of 2004-2005, the death proportion of all the infectious diseases,maternal/perinatal diseases and nutritional deficiencies was 8.01% altogether, and those of chronic non-communicable diseases, injury and poisoning were 80.66% and 11.33%, respectively. During the past 30 years, the SMR of the three kinds of diseases all significantly decreased, more significantly seen in infectious diseases, maternal and perinatal diseases, and nutritional deficiencies but less in chronic non-communicable diseases. Among the death cases of chronic non-communicable diseases,the SMR of cerebrovascular disease, malignant tumor, and heart disease showed an increasing tendency and the sequences of them had been advanced to the first, the second, and the fourth in the death ranking during the period of 2004-2005, respectively. Conclusion The SMRs of the residents in the urban and rural areas from Hunan province showed a declining tendency.Cardiovascular, cerebrovascular diseases and malignant tumors had become the important diseases affecting the health of the people, while injury and poisoning had otherwise topped the causes of death among children and adolescents in Hunan province.

Surgical treatment results and prognostic analysis of 514 cases with gastroesophageal junction carcinoma / 中华外科杂志

<p><b>OBJECTIVE</b>To clarify the important clinicopathological and therapeutical factors affecting the prognosis of patients with gastroesophageal junction carcinoma.</p><p><b>METHODS</b>Data of 514 cases with gastroesophageal junction carcinoma who underwent surgical treatment from September 1995 to January 2007 was retrospectively analyzed. Relevant prognostic factors were studied with univariate and multivariate analysis.</p><p><b>RESULTS</b>For all 514 cases (424 men and 90 women), the median age was 63 years. The 1-, 3- and 5-year survival rates of this group were 74.8%, 42.1% and 29.1%, respectively. Gross type, TNM classification, histological type, vascular invasion and extent of surgical resection affected patients' survival remarkably. There was no significant difference in survival between operative approaches (via laparotomy or left thoracotomy) (P > 0.05). Long-term survival was similar between proximal subtotal gastrectomy and total gastrectomy in advanced cases (P > 0.05). For stage II and III tumors, patients with neoadjuvant chemotherapy had better prognosis than those without (P < 0.05). Cox multivariate regression analysis revealed TNM classification and vascular invasion were independent prognostic factors.</p><p><b>CONCLUSIONS</b>TNM classification and vascular invasion are independent prognostic factors for gastroesophageal junction carcinoma. Neoadjuvant chemotherapy may improve prognosis of the patients with stage II and III tumors. Radical resection should be achieved with rational surgical procedures tailored by tumor position, size, staging and so on.</p>

External fixation and bone grafting for collapsed and comminuted distal radius fracture / 中华创伤杂志(英文版)

<p><b>OBJECTIVE</b>To study the therapeutic effect of collapsed and comminuted distal radius fracture.</p><p><b>METHODS</b>Twenty-six patients with collapsed and comminuted distal radius fracture were hospitalized from July 1998 to June 2003. All fractures were treated by the methods of open reduction, sustained bone grafting and passing joint external fixator to restore the anatomic shape of distal radius.</p><p><b>RESULTS</b>All 26 cases were followed up, and the results showed that the fractures have been united radiographically. The joint surfaces were intact and there was no length discrepancy occurred in patient's radius. The average volar tilt was 6 to 15 degrees and the average ulnar tilt was 18 to 25 degrees. According to the Dieust criterion, 19 cases were rated as excellent and 7 as good.</p><p><b>CONCLUSIONS</b>The method that applying passing joint external fixator and bone grafting for the treatment of collapsed and comminuted distal radius fracture could maintain the stability of fracture and restore the length of radius and the intact of joint surface.</p>

Mutation analysis of hMSH2 and hMLH1 genes in Chinese hereditary nonpolyposis colorectal cancer families / 中华病理学杂志

<p><b>OBJECTIVES</b>To determine the germ-line mutations of hMSH2 and hMLH1 genes in Chinese hereditary nonpolyposis colorectal cancer (HNPCC) families' probands or in patients fulfilling different clinical criteria or guidelines; to clarify the nature and distribution of the mutations; to evaluate the sensitivity of different clinical criteria in mutation prediction.</p><p><b>METHODS</b>The entire coding regions (35 exons including exon-intron boundaries) of hMSH2 and hMLH1 genes were directly sequenced in 24 Amsterdam criteria (AC) probands, 15 Japanese criteria (JC) probands (except AC kindreds) and 19 Bethesda guidelines (BG) patients (except two former groups). All available affected and unaffected members from families of those with mutations were screened for mutation.</p><p><b>RESULTS</b>In 16 unrelated families selected by the different clinical criteria, 17 germ-line mutations were found with 11 (64.7%) of hMLH1 and 6 (35.3%) of hMSH2. Two mutations were identified in one of the families. Among the 17 germ-line mutations, 12 had not been reported previously. A diversified mutation spectrum was found, but 6 hMLH1 mutations were found to be concentrated in the region encompassing exon 14, 15 and 16. There was a wide spectrum of mutation type including frame shift, nonsense, splice site mutation, in frame insertion or deletion and missense mutations. The mutation detection rate of hMSH2 and hMLH1 in the AC group was significantly higher than that in the JC group (12/24 vs. 3/15). On the other hand, a low mutation rate (1/19) was detected in 19 BG patients. The mutation cosegregated with disease. Besides, three different genotypes in tumors from probands of mutation-positive families were found.</p><p><b>CONCLUSIONS</b>hMSH2 and hMLH1 mutations in Chinese HNPCC families show a wide spectrum. It seems that hMLH1 gene is involved more frequently than hMSH2 gene in Chinese HNPCC families. Different clinical criteria predict mutations with different sensitivities. The Amsterdam Criteria are most sensitive, while Japanese Criteria are highly practical and the Bethesda Guidelines are also practical to some extent. Gene mutations cosegregate with the disease phenotype. Carriers with no symptom in HNPCC families are most vulnerable groups, follow-ups are required for this group to get early diagnosis and to prevent the development of CRCs.</p>

Quantitation & optimization of guanosine fermentation process: prevention of NH4+ accumulation increases guanosine production by 70% / 生物工程学报

Metabolic engineering has become a powerful tool for optimization of industrial fermentation processes. Metabolic engineering usually undergoes three steps: construction of a recombinant strain with improved properties, genetic and biochemical analysis of the strain, and identification of target for further improvement. Metabolic fluxes analysis is an important part of the biochemical analysis. Based on the law of mass conservation and assuming pseudo-steady-state for the intermediates in the metabolic pathways, we have quantitatively analyzed the time course of the flux distribution in Bacillus subtilis and used the data to reveal the nature of the so-called "40 hour" phenomenon in fermentation of guanosine, a key raw material for the synthesis of additives for human consumption and animal feeds. The phenomenon refers to the observation that guanosine production, which proceeds at high rate from 12 hour on, declines around 40 hour while consumption of glucose keeps increasing, leading to the lower yield of the nucleoside. Equations based upon the metabolic network of Bacillus subtilis consisted of EMP pathway, HMP pathway, TCA cycle, oxidative phosphorylation pathway and others reactions of the intermediates, was constructed. The equations were solved by using the quantitative data obtained in this study. The air flow and volume, concentration of oxygen and carbon dioxide in the exit-gas were monitored online; the concentration of biomass, glucose and guanosine was analyzed manually; and the concentration of acetate, citric acid, pyruvate, and 17 amino acids were HPLC quantified. The solutions of the equation were proved to be valid, as the experimental data on oxygen consumption agrees with that of predicted form the equation. The results indicated that at 40h of the fermentation process the flux of HMP pathway, which provides the precursor of the nucleoside, decreased while that of EMP pathway and the pathways that generate amino acids and organic acids increased. The shift correlated with the accumulation of NH4+ in the broth. The assimilation of NH4+ is an energy consuming process and could shift the metabolism to the energy generating EMP pathway. Accordingly, measures were taken to prevent the accumulation of NH4+. The interference indeed stopped the metabolism shift and boosted the guanosine production at 30 g/L, 70% higher than the level reported in literature.

The investigation of hematopoietic capacity of HPP-CFC derived from murine embryonic stem cells in vitro and in vivo / 生物工程学报

The hematopoietic system of the mouse arises from extraembryonic mesoderm that migrate through primitive streak to the presumptive yolk sac at day 7.0 of gestation. However, the mechanisms regulating mesoderm commitment to hematopoietic lineages remain poorly understood. Previous studies demonstrated that the development kinetics and growth factor responsiveness of hematopoietic precursors derived from embryonic stem cells (ES cells) is similar to that found in the yolk sac, indicating that the onset of hematopoiesis within the embryoid bodies (EBs) parallels that found in the embryo. Furthermore, in vitro differentiation of ES cells to hematopoietic cells is valuable for establishment of therapeutic clone against a variety of hematological disorders. Despite the identification of multipotential hematopoietic progenitors in EBs, a subset of more primitive progenitors, identical to the high proliferative potential colony-forming cells (HPP-CFC) derived from human and murine hematopoietic tissues, have not been clearly identified regarding particular their replating potential in vitro. HPP-CFC is among the most primitive hematopoietic multipotent precursors cultured in vitro. In this study, our aim was to investigate the in vitro and in vivo hematopoietic capacity of HPP-CFC within the day 12 EBs, rather than the expansion of more committed progenitors. In this study the HPP-CFC could be detected within EBs differentiated for 5 to 14 days of murine ES cells, but the development dynamics of the HPP-CFC differed greatly among distinct serum lots. Qualitatively HPP-CFC is capable of forming secondary colonies. As to our expectation the ES cells-derived HPP-CFC demonstrated similar regeneration capacity to those from yolk sac, giving rise to secondary granulocyte, erythrocyte, macrophage and mast cells, however largely differed from the counterparts of adult bone marrow. In addition, by RT-PCR ES cells-derived HPP-CFC were found to express transcription factors associated closely with stem cell proliferation including SCL, GATA-2 and AML1 as well as various receptors of hematopoietic growth factors such as c-kit, GM-CSF receptor and interleukin 3 receptor et al. Finally, in order to understand the in vivo hematopoietic capacity of the ES cells-derived HPP-CFC, spleen colony-forming unit (CFU-S) assay was performed. Nevertheless, typical CFU-S was not observed after transplantation of the day 12 EB cells or HPP-CFC colonies into lethally irradiated adult murine. In conclusion the HPP-CFC differentiated from murine ES cells displayed robust hematopoietic activity in vitro, however their in vivo reconstitution ability was not detected. The difference between in vitro and in vivo hematopoietic activities of ES cells-derived primitive hematopoietic precursors deserves further investigation.

Studies on chemical constituents from the stems of Schisandra sphaerandra / 中国中药杂志

<p><b>OBJECTIVE</b>To investigate the chemical constituents from the stems of Schisandra sphaerandra.</p><p><b>METHOD</b>Compounds were isolated from ethanolic extract of the titled herb by silica gel column chromatography, and their structures were elucidated by physical and chemical evidences and spectroscopic analysis.</p><p><b>RESULT</b>12 compounds were obtained and identified as wuweizisu C (1), ganwuweizic acid (2), nigranoic acid (3), catechin (4), 2 alpha,24-dihytroxyursolic acid. (5), 3 beta-O-acetylursolic acid (6), ursolic acid (7), slyceryl 26-hydroxyhexacosanoate (8), slyceryl hexacosanoate (9), fat acids (10), beta-sitosterol (11), daucosterol (12), respectirely.</p><p><b>CONCLUSION</b>Three pentacyclic triterpene carboxylic acid (5-7) were isolated from Schisandreae for the first time.</p>

Analysis on metabolic flux shift during guanosine fermentation / 生物工程学报

Taking the typical metabolic control product-guanosine as an example, the method of metabolic flux shift investigation based on process multi-levels parameter correlation analysis was established. The metabolic pathway, multi-parameter correlation, accumulation of amino acid and organic acid during guanosine fermentation process were integratively analyzed. The metabolic flux shift from HMP to EMP was ascertained, which was assumed to be caused by the accumulation of ammonium ion. The subsequent optimization based on controlling flux distribution between EMP and HMP did improve the yield by 35% when the metabolic flux shift was prevented.

Human umbilical vein endothelial cells support hematopoiesis and expansion of hematopoietic stem/progenitor cells in vitro / 军事医学科学院院刊

Objective: To investigate the role of human umbilical vein endothelial cells (HUVEC) in supporting hematopoiesis and the expansion of hematopoietic stem/progenitor cells in vitro. Methods: According to the fact that HUVEC supernatant has colony stimulating activity shown by methylcellulose colony-forming assay and HUVEC can maintain the survival of mononuclear cells for at least four weeks in vitro, CD34+ cells from umbilical cord blood were seeded with (HUVEC group) or without (control group) HUVEC monolayer. Every week cells were collected and counted, the frequency of CFU-GM was measured by using methylcellulose colony-forming assay, and the percentage of CD34+ and CD41a+ cells was measured by flow cytometry. Results: In control group，all the CD34+ cells died in two weeks. However, in HUVEC group,most nucleated cells and CD34+ cells were expanded by 68.1±14.8 fold and 6.6±1.4 fold，respectively at the third week while CFU-GM expansion reached its peak (5.7±2.1 fold) at the week 2. Moreover, the percentage of CD41a+ cells was enhanced significantly, reaching a maximum (15.6%) at the week 3. Conclusions:HUVEC can support hematopoiesis in vitro and expand the hematopoietic progenitor cells and CD41a+ cells in direct contact coculture.