Three-dimensional Fluid-Structure Interaction Model of Venous Valve Based on Immersed Boundary/Finite Element Method / 医用生物力学

Objective To explore the dynamic process of fluid-structure interaction(FSI)between venous blood and valves and the physiological mechanism that guarantees unidirectional blood reflux back to the heart.Methods A three-dimensional(3D)numerical model of the venous system was established using the immersed boundary/finite element method.In the simulation,information from medical images of human lower-extremity veins and the anatomical structure and size of the bovine great saphenous vein were applied.Moreover,a hyperelastic constitutive model was used to describe the incompressible,nonlinear,and hyperelastic mechanical responses of the venous valve under physiological conditions.Results The simulations visualized the process of venous blood transport and the function of venous valves in preventing reflux.The periodic characteristics of venous valve motion and blood flow were reproduced,and important physiological data during the entire cardiac cycle were discussed and quantified,including the pressure,velocity,and flow rate of venous blood;opening area of the venous valve;and stress and strain distributions on the valve surface.Conclusions The 3D FSI model numerically reproduces the physiological dynamic process within veins and potentially provides important references and guidance for revealing the pathological mechanism of venous diseases.

Research progress on the mechanism of retinal light injury / 国际眼科杂志(Guoji Yanke Zazhi)

The retina is a highly specialized tissue with unique structure and adaptability. Maintaining dynamic balance in all different types of retinal cells is essential for maintaining vision. The retina may be exposed to a variety of environmental damage such as light-induced damage, and over the course of evolution, retinal cells have developed adaptive responses to various injuries that together restore dynamic cellular homeostasis and increase the resistance of the tissue to further damage. Howecer, excessive exposure to light can cause a series of pathological changes in photoreceptors, retinal ganglion cells(RGC), retinal glial cells and retinal pigment epithelium(RPE)cells, such as increased expression of reactive oxygen species(ROS)and Ca2+ in mitochondria, apoptosis, endoplasmic reticulum stress, autophagy and inflammation, etc., leading to irreversible damage to the retina. In the present article, the possible pathogenesis and current related research progress of light-induced injury were reviewed, in order to provide research directions for the prevention and treatment of retinal light injury.

The efficacy of radiotherapy based combined therapy for unresectable locally invasive bladder cancer and its associated factors analysis / 中华肿瘤杂志

Objective: Retrospective analysis of the efficacy and influencing factors of bladder preservation integrated therapy for unresectable invasive bladder cancer confined to the pelvis was done, also including the bladder function preservation and adverse effects analysis. Methods: Sixty-nine patients with unresectable locally invasive bladder cancer who received radiotherapy-based combination therapy from March 1999 to December 2021 at our hospital were selected. Among them, 42 patients received concurrent chemoradiotherapy, 32 underwent neoadjuvant chemotherapyand 43 with transurethral resection of bladder tumors (TURBT) prior to radiotherapy. The late adverse effect of radiotherapy, preservation of bladder function, replase and metastasis and survival were followed-up. Cox proportional hazards models were applied for the multifactorial analysis. Results: The median age was 69 years. There were 63 cases (91.3%) of uroepithelial carcinoma, 64 of stage Ⅲ and 4 of stage Ⅳ. The median duration of follow-up was 76 months. There were 7 grade 2 late genito urinary toxicities, 2 grade 2 gastrointestinal toxicities, no grade 3 or higher adverse events occurred. All patients maintained normal bladder function, except for 8 cases who lost bladder function due to uncontrolled tumor in the bladder. Seventeen cases recurred locally. There were 11 cases in the concurrent chemoradiotherapy group with a local recurrence rate of 26.2% (11/42) and 6 cases in the non-concurrent chemoradiotherapy group with a local recurrence rate of 22.2% (6/27), and the difference in local recurrence rate between the two groups was not statistically significant (P=0.709). There were 23 cases of distant metastasis (including 2 cases of local recurrence with distant metastasis), including 10 cases in the concurrent chemoradiotherapy group with a distant metastasis rate of 23.8% (10/42) and 13 cases in the non-concurrent chemoradiotherapy group with a distant metastasis rate of 48.1% (13/27), and the distant metastasis rate in the non-concurrent chemoradiotherapy group was higher than that in the concurrent chemoradiotherapy group (P=0.036). The median 5-year overall survival (OS) time was 59 months and the OS rate was 47.8%. The 5-year progression-free survival (PFS) time was 20 months and the PFS rate was 34.4%. The 5-year OS rates of concurrent and non-concurrent chemoradiotherapy group were 62.9% and 27.6% (P<0.001), and 5-year PFS rates were 45.4% and 20.0%, respectively (P=0.022). The 5-year OS rates of with or without neoadjuvant chemotherapy were 78.4% and 30.1% (P=0.002), and the 5-year PFS rates were 49.1% and 25.1% (P=0.087), respectively. The 5-year OS rates with or without TURBT before radiotherapy were 45.5% and 51.9% (P=0.233) and the 5-year PFS rates were 30.8% and 39.9% (P=0.198), respectively. Multivariate Cox regression analysis results showed that the clinical stage (HR=0.422, 95% CI: 0.205-0.869) was independent prognostic factor for PFS of invasive bladder cancer. The multivariate analysis showed that clinical stages (HR=0.278, 95% CI: 0.114-0.678), concurrent chemoradiotherapy (HR=0.391, 95% CI: 0.165-0.930), neoadjuvant chemotherapy (HR=0.188, 95% CI: 0.058-0.611), and recurrences (HR=10.855, 95% CI: 3.655-32.638) were independent prognostic factors for OS of invasive bladder cancer. Conclusion: Unresectable localized invasive bladder cancer can achieve satisfactory long-term outcomes with bladder-preserving combination therapy based on radiotherapy, most patients can retain normal bladder function with acceptable late adverse effects and improved survival particularly evident in patients with early, concurrent chemoradiotherapy and neoadjuvant chemotherapy.

Discussion on Collection of Clinical Questions in International Clinical Practice Guidelines of Acupuncture-Moxibustion / 中国结合医学杂志

The clinical questions of acupuncture-moxibustion (Acup-Mox) guidelines are complicated, including not only the curative effect of Acup-Mox intervention measures, but also the operational elements of Acup-Mox. This paper aimed to put forward the idea and process of collecting clinical questions in developing international acupuncture clinical practice guidelines. The experience was collected and the idea of collecting clinical questions of Acup-Mox was formed through expert consultation and discussion in combination with expert opinions. Based on the characteristics of Acup-Mox discipline. This paper put forward the thinking of collecting elements of clinical questions following the intervention-population-outcome-control (I-P-O-C) inquiry process, according to the discipline of Acup-Mox. It was emphasized that in the process of collecting clinical questions, "treatable population" and "alleviable outcome indicators" for a specific Acup-Mox intervention with certain therapeutic effect should be focused on, so as to highlight the pertinence of clinical questions of Acup-Mox guidelines in terms of population and outcome elements.

Study on alleviating alcoholic fatty liver with Milk derived pentapeptide PGPIP and its mechanism / 安徽医科大学学报

Objective @# To investigate the effects of milk derived pentapeptide prolin⁃glycine⁃proline⁃isoleucine⁃pro⁃ line ( PGPIP) on chronic alcoholic liver injury in mice and its related molecular mechanism . @*Methods @#Forty C57BL/6 mice were randomly divided into control group , model group , glutathione(GSH) group , PGPIPN group .The mice model of chronic alcoholic fatty liver was established by 10 d ad libitum oral feeding with the Lieber⁃DeCarli(LD) ethanol liquid diet plus one binge . Drug intervention was given at the same time . Based on the reported RNA sequencing data in gene expression omnibus (GEO) database , the differential expression of liver endoplasmic reticulum stress⁃related genes was analyzed by cluster heat map . Liver hematoxylin⁃eosin (HE) staining was used to analyze the pathological effects of each treatment group on alcoholic liver injury in mice . Oiled Red O staining was used to analyze the effects of each treatment group on the accumulation of liver lipid droplets in mice . Transtransduction protein expression was detected by Western blot . @*Results @#The pathological examination of PGPIP group was similar to that of Control group , and the liver injury of mice was significantly reduced . The accumulation of lipid droplets in the liver of mice in the model group was manifested as mixed lipid droplets of different sizes , and PGPIP treatment significantly reduced the accumulation of liver lipid droplets induced by alcohol . PGPIP had significant effects on the PERK⁃eIF2α⁃ATF4 pathway and the expression of transcriptional activator 6 ( ATF6 ), Cleaved Caspase 3 protein . @*Conclusion @#Pentapeptide PGPIP can alleviate chronic alcoholic fatty liver and liver injury in mice . The mechanism may be attributed to reducing the accumulation of lipid droplets in hepatocytes , en⁃ doplasmic reticulum stress , and hepatocyte apoptosis .

Differences in Contents and Formation Methods of Clinical Questions in Chinese and Korean Clinical Practice Guidelines of Acupuncture-Moxibustion: Scoping Review / 中国结合医学杂志

OBJECTIVE@#To analyze the differences in the needs of users and the value orientation of clinical practice guidelines (CPGs) by comparing the contents and formation methods of clinical questions in Chinese and Korean CPGs of acupuncture-moxibustion (Acup-Mox).@*METHODS@#The full text of CPGs was systematically searched from the official websites of Chinese and Korean traditional medicine societies and Acup-Mox associations, with the topic "Acup-Mox for treating diseases" and the retrieval time up to September 28, 2022. Two researchers screened the CPGs independently, and extracted the guidelines' topics, content, quantity and formation methods of clinical questions. The quantitative data were collected by counting the frequency, and the qualitative data were classified and described by thematic analysis.@*RESULTS@#A total of 29 guidelines were included in this study, including 20 Chinese guidelines (305 questions) and 9 Korean guidelines (223 questions). The differences lie in the aspects of content and diversity, and formation method. As for content and diversity, Chinese guidelines focused mainly on the questions related to treatment such as the operation of specific intervention (86, 28.2%), efficacy of intervention (78, 25.6%), and also involving questions in diagnosis, prevention, and prognosis. While the clinical questions in Korean guidelines were concentrated to efficacy of intervention (218, 97.8%). As for formation method, in Chinese guidelines, questions were usually collected directly from clinicians, and then determined and optimized by experts. In Korean guidelines, frequently used clinical Acup-Mox interventions would be screened first. Then the expert group would set up corresponding intervention control measures so as to form clinical questions related to treatment efficacy.@*CONCLUSIONS@#The differences reflect the different needs of clinical practitioners, and the different aims or concepts in developing Acup-Mox guidelines between China and South Korea. Chinese guidelines emphasized promoting operation protocols and techniques of Acup-Mox for practical use, while Korean guidelines emphasized promoting the frequently used clinical intervention therapies. It is speculated that the guidelines from these two countries would play different roles in guiding clinical operation and supporting medical decision. In terms of formation methods of clinical questions, it is suggested to attach importance to optimizing process in formatting clinical questions to improve the clinical applicability of CPGs of Acup-Mox.

Stereotactic body radiation therapy for patients with lung and liver oligometastases from colorectal cancer: a phase Ⅱ trial / 中华肿瘤杂志

Objective: To explore the safety and effectiveness of stereotactic body radiation therapy (SBRT) for oligometastases from colorectal cancer (CRC). Methods: This is a prospective, single-arm phase Ⅱ trial. Patients who had histologically proven CRC, 1 to 5 detectable liver or lung metastatic lesions with maximum diameter of any metastases ≤5 cm were eligible. SBRT was delivered to all lesions. The primary endpoint was 3-year local control (LC). The secondary endpoints were treatment-related acute toxicities of grade 3 and above, 1-year and 3-year overall survival (OS) and progression free survival (PFS). Survival analysis was performed using the Kaplan-Meier method and Log rank test. Results: Petients from 2016 to 2019 who were treated in Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College. Forty-eight patients with 60 lesions were enrolled, including 37 liver lesions and 23 lung lesions. Forty-six patients had 1 or 2 lesions, with median diameter of 1.3 cm, the median biologically effective dose (BED(10)) was 100.0 Gy. The median follow-up was 19.5 months for all lesions. Twenty-five lesions developed local failure, the median local progression free survival was 15 months. The 1-year LC, OS and PFS was 70.2% (95% CI, 63.7%~76.7%), 89.0% (95% CI, 84.3%~93.7%) and 40.4% (95%CI, 33.0%~47.8%). The univariate analysis revealed that planning target volume (PTV) and total dose were independent prognostic factors of LC (P<0.05). For liver and lung lesions, the 1-year LC, OS and PFS was 58.7% and 89.4% (P=0.015), 89.3% and 86.5% (P=0.732), 30.5% and 65.6% (P=0.024), respectively. No patients developed acute toxicity of grade 3 and above. Conclusion: SBRT is safe and effective treatment method for oligometastases from CRC under precise respiratory motion management and robust quality assurance.

Analysis and thought on reaching the consensus during the development of acupuncture and moxibustion clinical practice guidelines in China / 中国针灸

Based on the 28 Chinese clinical practice guidelines of acupuncture and moxibustion, this study summarized and analyzed the contents related to reaching consensus during the development process. The results indicated that all the 28 guidelines reported they have used consensus in the "recommendations" section, and provided details on consensus personnel, consensus methods, consensus process and consensus materials. However, it was found that the reporting of consensus was in need of further improvement. The limitations included unclear definition and responsibilities of "expert group", obscure concept between "consensus meeting" and "expert discussion", non-rigorous process of reaching consensus when generating recommendations and lacking of detailed reporting of the consensus reaching process. As such, we suggested that future researchers should conduct researches to further standardized the consensus process when developing acupuncture and moxibustion clinical practice guidelines, so as to improve the quality and clinical applicability of guidelines．.

Milk derived hexapeptide reduces alcohol －induced oxidative stress and alleviates liver injury through FoxO3a －MnSOD signaling pathway / 安徽医科大学学报

Objective @#To investing ate the milk-derived hexapeptide PGPIPN and its truncated pentapeptide PGPIP to alleviate chronic alcoholic liver injury in mice and its associated molecular mechanisms．@*Methods @#Sixty Kun- ming mice were randomly divided into control group，model group，GSH group，PGPIPN group，and truncated pen- tapeptide PGPIP group．The model of chronic alcoholic liver injury in mice was established by gavage with gradient alcohol． Drug intervention was given at the same time for 12 weeks． Liver HE staining was used to analyze the pathological effects of each treatment group on alcoholic liver injury in mice．Primary mouse hepatocytes and human normal hepatocyte line L-02 were isolated and cultured in vitro．The appropriate PGPIPN induction concentrations of both cells were determined by WST-1 method． L-02 cells were induced at different times． The expression of FoxO3a and phosphorylated FoxO3a protein were detected by Western blot to determine the appropriate induction time．The subcellular localization of FoxO3a in L-02 cells was detected by cellular immunofluorescence．The mR- NA changes of FoxO3a and MnSOD genes in primary hepatocytes and L-02 cells of mice in different treatment groups were detected by qRT-PCR.@*Results @#The pathological examination of PGPIPN group and PGPIP group was similar to that of GSH group，and the liver injury of mice was significantly reduced．Medium and high concentra- tions of PGPIPN were respectively selected to induce mouse primary hepatocytes and L-02 cells．At 16 hours，the expression of FoxO3a protein in L-02 cells increased significantly．FoxO3a protein was mainly expressed in the nu- cleus．In addition，mRNA levels in both types of cells increased significantly after induction with the corresponding dose of PGPIPN．@*Conclusion @#PGPIPN and truncated pentapeptide PGPIP can reduce chronic alcoholic liver injury in mice．The mechanism may be to reduce alcohol-induced oxidative stress through FoxO3a-MnSOD signaling path- way.

Investigation and analysis on the current situation of clinical practice guidelines for acupuncture and moxibustion at home and abroad / 中国针灸

To provide directional suggestions for the establishment of international clinical practice guidelines for acupuncture and moxibustion by investigating the current situation of clinical practice guidelines for acupuncture and moxibustion at home and abroad. The clinical practice guidelines were obtained by questionnaire survey, database retrieval and experts consulting. The guidelines were read carefully, and the content was analyzed. A total of 27 acupuncture-moxibustion clinical practice guidelines were retrieved, of which most of the guidelines came from China. The definition and scope of "acupuncture and moxibustion "vary according to different guidelines; and the focus of the content and the method of establishing the guidelines are quite different, so it is very necessary to unify the formulation methods of acupuncture-moxibustion clinical practice guidelines. Chinese clinical practice guidelines for acupuncture and moxibustion were characterized by taking the ancient literature as the evidence. Excavating the value of ancient literature and clinical experience of acupuncture-moxibustion experts are the key points and difficulties in the developing of clinical practice guidelines of acupuncture and moxibustion in the future.

Consideration on existing problems in development of clinical practice guidelines for acupuncture and moxibustion in China / 中国针灸

To sort out the existing problems within the published 35 evidence-based acupuncture-moxibustion clinical practice guidelines (group standards) in Chinese: the development methods and the development process are not clear and strict enough; the evidence evaluation system fails to fully reflect the characteristics of acupuncture and moxibustion. Therefore,

Oral contrast agents lead to underestimation of dose calculation in volumetric-modulated arc therapy planning for pelvic irradiation / 中华医学杂志(英文版)

BACKGROUND@#The effects of oral contrast agents (OCAs) on dosimetry have not been studied in detail. Therefore, this study aimed to examine the influence of OCAs on dose calculation in volumetric-modulated arc therapy plans for rectal cancer.@*METHODS@#From 2008 to 2016, computed tomography (CT) images were obtained from 33 rectal cancer patients administered OCA with or without intravenous contrast agent (ICA) and 14 patients who received no contrast agent. CT numbers of organs at risk were recorded and converted to electronic densities. Volumetric-modulated arc therapy plans were designed before and after the original densities were replaced with non-enhanced densities. Doses to the planned target volume (PTV) and organs at risk were compared between the plans.@*RESULTS@#OCA significantly increased the mean and maximum densities of the bowels, while the effects of ICA on these parameters depended on the blood supply of the organs. With OCA, the actual doses for PTV were significantly higher than planned and doses to the bowel increased significantly although moderately. However, the increase in the volume receiving a high-range doses was substantial (the absolute change of intestine volume receiving ≥52 Gy: 1.46 [0.05-3.99, cubic centimeter range: -6.74 to 128.12], the absolute change of colon volume receiving ≥50 Gy: 0.34 [0.01-1.53 cc, range: -0.08 to 3.80 cc]. Dose changes due to ICA were insignificant. Pearson correlation showed that dose changes were significantly correlated with a high intestinal volume within or near the PTV (ρ > 0.5, P  0.3, P < 0.05).@*CONCLUSIONS@#Contrast agents applied in simulation cause underestimation of doses in actual treatment. The overdose due to ICA was slight, while that due to OCA was moderate. The bowel volume receiving ≥50Gy was dramatically increased when OCA within the bowel was absent. Physicians should be aware of these issues if the original plan is barely within clinical tolerance or if a considerable volume of enhanced intestine is within or near the PTV.

Correlation of insulin resistance with male reproductive hormone levels and semen parameters / 中华男科学杂志

<p><b>Objective</b>To investigate the influence of insulin resistance on male reproductive hormones and semen quality.</p><p><b>METHODS</b>Using the electrochemiluminescence method, we measured the levels of follicle stimulating hormone (FSH), luteinizing hormone (LH), prolactin (PRL), estradiol (E2) and testosterone (T) in the serum of 83 infertile males. We detected the levels of fasting plasma glucose (FPG) and fasting insulin (FINS) and calculated the insulin resistance index presented as homeostasis model assessment of insulin resistance (HOMA-IR). Based on HOMA-IR, we divided the patients into three tertile groups, T1 (HOMA-IR 0.36－0.55, n = 27), T2 (HOMA-IR 0.56－0.80, n = 28) and T3 (HOMA-IR 0.81－1.97, n = 28), obtained their semen parameters by computer-assisted semen analysis (CASA) and analyzed the correlation of HOMA-IR with male reproductive hormone levels and semen parameters.</p><p><b>RESULTS</b>With the elevation of HOMA-IR, the patients of the T1, T2 and T3 groups showed significant decreases in the serum T level (［14,26 ± 4.27］ vs ［14.75 ± 5.00］ vs ［11.62 ± 3.68］ nmol/L, P <0.05) and the percentage of progressively motile sperm (PMS) (［51.04 ± 15.10］% vs ［48.04 ± 16.24］% vs ［37.84 ± 18.23］%, P <0.05). HOMA-IR was correlated negatively with the serum T level (r = －0.333, P = 0.002), semen volume (r = －0.23, P = 0.029) and PMS (r = －0.27, P = 0.015), and so was FINS with the serum T level (r = －0.327, P = 0.003) and PMS (r = －0.315, P = 0.004), while the semen volume was correlated positively with the levels of serum T (r = 0.221, P = 0.048) and FSH (r = 0.222, P = 0.047). Multivariate linear regression analysis showed that HOMA-IR was an independent influencing factor for PMS and the body mass index (BMI) was that for the semen volume and total sperm count.</p><p><b>CONCLUSIONS</b>Insulin resistance may reduce semen quality by changing the levels of male reproductive hormones.</p>

Correlation of seminal plasma zinc alpha-2 glycoprotein with semen quality in obese males / 中华男科学杂志

<p><b>Objective</b>To investigate the relationship between seminal plasma zinc alpha-2 glycoprotein (ZAG) and semen quality in obese males.</p><p><b>METHODS</b>This study included 130 obese male patients with idiopathic infertility Based on the concentration of seminal plasma ZAG, we divided the patients into three tertile groups: tertile 1 (T1, 73.45－97.15 μg/ml, n = 43), T2 (97.16－115.46 μg/ml, n = 44), and T3 (115.47－220.11 μg/ml, n = 43). We measured the concentrations of seminal plasma zinc (SPZ) and ZAG of the patients by ELISA, obtained the semen parameters, and analyzed the correlation of semen quality with the levels of SPZ and ZAG and the influence of obesity on SPZ, ZAG and semen quality.</p><p><b>RESULTS</b>The mean level of seminal plasma ZAG in the 130 obese male patients was (111.29 ± 26.50) μg/ml. There were statistically significant differences in sperm concentration and total sperm count among the three tertile groups (P < 0.05). The level of seminal plasma ZAG was correlated negatively with the body mass index (BMI), waist circumference (WC), sperm concentration and sperm count (P < 0.01), that of SPZ positively with BMI and WC (P < 0.05) but negatively with semen volume and the percentage of progressively motile sperm (P < 0.05). The level of serum ZAG, however, exhibited no correlation with SPZ, seminal plasma ZAG or semen quality. Obesity was found to be associated with significantly decreased concentration of seminal plasma ZAG and percentage of progressively motile sperm but remarkably increased level of SPZ (P < 0.05).</p><p><b>CONCLUSIONS</b>Obesity may induce the metabolic disorder of SPZ and ZAG, change the microenvironment of seminal plasma, and consequently affect semen quality.</p>

Buffering action of acetate on hydrogen production by Ethanoligenens harbinense B49

The buffering effect of acetate on hydrogen production during glucose fermentation by Ethanoligenens harbinense B49 was investigated compared to phosphate, a widely used fermentative hydrogen production buffer. Specific concentrations of sodium acetate or phosphate were added to batch cultures, and the effects on hydrogen production were comparatively analyzed using a modified Gompertz model. Adding 50 mM acetate or phosphate suppressed the hydrogen production peak and slightly extended the lag phase. However, the overall hydrogen yields were 113.5 and 108.5 mmol/L, respectively, and the final pH was effectively controlled. Acetate buffered against hydrogen production more effectively than did phosphate, promoting cell growth and preventing decreased pH. At buffer concentrations 100-250 mM, the maximum hydrogen production was barely suppressed, and the lag phase extended past 7 h. Therefore, although acetate inhibits hydrogen production, using acetate as a buffer (like phosphate) effectively prevented pH drops and increased substrate consumption, enhancing hydrogen production.

A survey on adolescent scoliosis in Guangzhou / 中华流行病学杂志

Objective To investigate the prevalence of adolescent scoliosis in Guangzhou for development of effective prevention and treatment program to the disease. Methods From November2007 to July 2009, 30 142 students between 7 to 20 years old in primary and junior middle schools received physical check-up for detection of scoliosis through physical and radiographic examination.Results 211 cases were diagnosed as scoliosis (Cobb angle≥10°) , with the prevalence rate as 0.70%. 192 patients with idiopathic scoliosis (IS) were detected, accounting for 91.00%. There were 19 cases of congenital scoliosis, accounting for 9.00%. Sex ratio of scoliosis was 180/31. The prevalence of scoliosis was significantly lower in boys than that in girls (x2= 112.332, P＜0.001 ).Conclusion The crude prevalence of adolescent scoliosis was 0.70% in Guangzhou with majority of idiopathic scoliosis. Investigation on scoliosis among school-age population seemed to be important for the purposes of early diagnosis, selection of effective prevention and treatment.

Optimal Conditions and Validation of Single-strand Conformation Polymorphism Technology for the Analysis of Microbial Communities in Activated Sludge / 微生物学通报

Single-Strand Conformation Polymorphism(SSCP) is an effect method for investigating environment microbial genetic polymorphism, with its characterization of rapidness, simplicity, and sensitivity. However, many factors can influence the results of SSCP in the analysis of complex environment samples, and its optimization is highly needed. In this paper, optimal PCR-SSCP conditions were discussed based on PAGE concentration, formamide deionized in denaturing loading buffer, electrophoresis time and temperature. The resluts showed that the optimal conditions were as follows: 16S rDNA V1~V3 was selected as the targeted gene, the ratio of acrylamide to N, N-dimethylacrylamide in 12% polyacrylamide gel electrophoresis(PAGE)gel was 49:1, the ratio of formamide deionized in denaturing loading buffer was 1:3, running the SSCP gel at 300 V for 18 h (under 4 ℃). Aside from this, the validations using samples from a simultaneous desulfurification and denitrification bioreactor were conducted under this optimal conditions.

Advances in the Research of Long Life Recombinant Protein Drug / 中国生物工程杂志

The recombinant protein drug usually has a short half-life after intravenous (IV) or subcutaneous (SC) administration. The methods of prolonging the half-life of recombinant protein drug in common use are mainly based on three principles: 1 Amplifying the molecule weight of protein drug; 2 Making use of drug balance in the blood; 3 Reducing Immunogenicity. Three methods were focused on: Analog construction, PEGylation and Albumin fusion technology. The characteristics, half-life and immunogenicity problem of their products in the market and under development are summarized.

Saccharomyces cerevisiae B5 efficiently and stereoselectively reduces 2'-chloroacetophenone to R-2'-chloro-1-phenylethanol in the presence of 5% ethanol / 生物工程学报

(R)-chlorprenaline, a selective activator of beta2 receptor and an effective drug for bronchitis and asthma, is industrially prepared from (R)-2'-chloro-1-phenyl-ethanol. In this communication, we describe (1) the identification of Saccharomyces cerevisiae B5 as an effective host for stereoselective reduction of 2'-chloroacetophenone to (R)-2'-chloro-1-phenyl-ethanol; (2) the presence of ethanol enhances the conversion; and (3) the biochemical factors that effect the yield of the product. Among the four yeast strains capable of reduction 2'-chloroacetophenone to (R)-2'-chloro-1-phenyl-ethanol we screened, Saccharomyces cerevisiae B5 showed the highest activity and stereoselectivity, and was used for the subsequent study. The effect of the presence of methanol, ethanol, 2-propanol, 1-butanol, glucose, glycerol and lactic acid was first investigated, as it was previously reported that they increased the yield and stereoselectivity of the reaction. The addition of the co-substrate methanol, ethanol, 2-propanol, 1-butanol, glucose and glycerol favored the formation of the 2'-chloroacetophenone to (R)-2'-chloro-1-phenyl-ethanol. Lactic acid inhibited the enzyme activity. Ethanol is the best co-substrate among the seven co-substrates and under the optimum concentration of 5% , the yield of (R)-2'-chloro-1-phenyl-ethanol was increased from 17% to 74%. The oxidation of ethanol regenerates NADH required for the reduction. The effects of the reaction time, pH, cell concentration, substrate concentration and temperature on the reduction were investigated next. The enantiometric excess of (R)-2'-chloro-1-phenyl-ethanol reached 100% under the optimal condition: pH8.0, 25 degrees C and 5% ethanol. The product yield went up with the increasing Saccharomyces cerevisiae B5 concentration and reached 100% when the cell dry weight was 10.75 mg/mL and 2'-chloroacetophenone was 6.47 mmol/L. The yield of (R)-2'-chloro-1-phenyl-ethanol decreased sharply with the increase of substrate concentration, as the high concentration of substrates is toxic to the cell and inhibits the activity of reductases. The aerobic cultivation of the yeast and shaking during the reaction increased the yield of (R)-2'-chloro-1-phenyl-ethanol. The yeast can be reused up to 15 times. This research paves the way for economical preparation of chiral 2'-chloroacetophenone to R-2'-chloro-1-phenylethanol.

APPLICATION OF FLUORESCENCE IN SITU HYBRIDIZATION (FISH) IN MICROBIAL ECOLOGY / 微生物学通报

Molecular technologies are sensitive, fast, and cheap in the study on microbial ecology. However, these methods do not provide information about morphology, number, and spatial distribution of the microorganisms. In contrast, Fluorescence in situ hybridization (FISH) combines the precision of molecular biology with the visual information from microscope, and permits visualization and identification of individual miciobial cells within their natural habitat. FISH not only allows the detection of slow growing microorganisms, but also of yet-to-be cultured. It is useful for many applications in diagnosis and assessment of the population structure of complex microbial communities, and is a powerful tool for molecular ecology studies in microbiology, In this paper, major techniques and progresses of FTSH were described. Its application in microbial ecology, as well as problems , pitfalls, and perspectives of FISH are discussed.