Alterations in the intestinal microbiota of preterm infants with neurodevelopmental impairments: a prospective cohort study / 中国当代儿科杂志

OBJECTIVES@#To investigate the difference in intestinal microbiota between preterm infants with neurodevelopmental impairment (NDI) and those without NDI.@*METHODS@#In this prospective cohort study, the preterm infants who were admitted to the neonatal intensive care unit of Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region from September 1, 2019 to September 30, 2021 were enrolled as subjects. According to the assessment results of Gesell Developmental Scale at the corrected gestational age of 1.5-2 years, they were divided into two groups: normal (n=115) and NDI (n=100). Fecal samples were collected one day before discharge, one day before introducing solid food, and at the corrected gestational age of 1 year. High-throughput sequencing was used to compare the composition of intestinal microbiota between groups.@*RESULTS@#Compared with the normal group, the NDI group had a significantly higher Shannon diversity index at the corrected gestational age of 1 year (P<0.05). The principal coordinate analysis showed a significant difference in the composition of intestinal microbiota between the two groups one day before introducing solid food and at the corrected gestational age of 1 year (P<0.05). Compared with the normal group, the NDI group had a significantly higher abundance of Bifidobacterium in the intestine at all three time points, a significantly higher abundance of Enterococcus one day before introducing solid food and at the corrected gestational age of 1 year, and a significantly lower abundance of Akkermansia one day before introducing solid food (P<0.05).@*CONCLUSIONS@#There are significant differences in the composition of intestinal microbiota between preterm infants with NDI and those without NDI. This study enriches the data on the characteristics of intestinal microbiota in preterm infants with NDI and provides reference for the microbiota therapy and intervention for NDI in preterm infants.

Risk factors for postoperative pulmonary complications in elderly patients undergoing hip fracture surgery: a meta-analysis / 中华麻醉学杂志

Objective:To systematically evaluate the risk factors for postoperative pulmonary complications (PPCs) in elderly patients undergoing hip fracture surgery.Methods:PubMed, Embase, Cochrance Library, CBM, CNKI and Wanfang Databases were searched.Search strategy was subject word combined with random word.The case control and cohort studies involving the influencing factors for PPCs in elderly patients undergoing hip fracture from January 2000 to November 2020 were retrieved.PPCs included pneumonia, aspiration pneumonitis, pulmonary infections, respiratory failure, atelectasis and pleural effusion, etc.The quality of literatures was assessed by using Newcastle-Ottawa Scale, data were extracted and analysis was performed using RevMan5.3 software.Results:A total of 18 studies were finally enrolled, including 15 case control studies and 3 cohort studies.The results of analysis showed that the advanced age, male, history of smoking, low body mass index, history of cerebrovascular accident, history of chronic obstructive pulmonary disease, history of diabetes, preoperative albumin concentration<35 g/L, preoperative hemoglobin concentration<120 g/L, American Society of Anesthesiologists Physical Status classification≥Ⅲ, operation delay≥48 h and general anesthesia were the risk factors for PPCs ( P<0.05). Conclusions:There are numerous risk factors for PPCs in elderly patients undergoing hip fracture surgery, and advanced age, male, history of smoking, low body mass index, history of cerebrovascular accident, history of chronic obstructive pulmonary disease, history of diabetes, preoperative albumin concentration<35 g/L, preoperative hemoglobin concentration<120 g/L, American Society of Anesthesiologists Physical Status classification≥Ⅲ, operation delay≥48 h and general anesthesia are the risk factors for PPCs in elderly patients undergoing hip fracture surgery.

Relationship between parental reproductive age and the risk of overweight and obesity in offspring / 中华预防医学杂志

Objective: To explore the role of parental reproductive age on the risk of overweight and obesity in offspring. Methods: The participants were derived from physical examination data of students aged 6-18 years in seven provinces in China, and questionnaire survey was used to collect demographic characteristics and lifestyle information of the students and their parents. A total of 41 567 children with complete data were included. According to the restricted cubic spline curve, maternal reproductive age was divided into three categories, 14-23, 24-28, and 29-38 years, and paternal reproductive age was divided into 14-23, 24-30, and 31-42 years. Multivariate logistic regression model was used to analyze the association between parental reproductive age and parental nutritional status and the risk of overweight and obesity in offspring. Results: The mean age of 41 567 children was (10.6±3.2) years, and the mean paternal and maternal age were (27.9±4.4) years and (25.8±4.0) years, respectively. The detection rate of overweight and obesity was 23.4%. After adjusting factors of children diet and behaviors, the OR(95%CI)of offspring overweight and obesity in groups of fathers aged 24-30 years and mothers aged 24-28 years was 1.11 (1.04-1.18) and 1.16 (1.08-1.24), respectively. When none parents were overweight and obese, the difference of obesity risk was not statistically significant. When both parents were overweight and obese, the OR(95%CI)of offspring overweight and obesity in groups of fathers aged 24-30 years and mothers aged 14-28 years old was 1.27 (1.00-1.62) and 1.33 (1.07-1.65) respectively. Conclusion: Parental reproductive age and parental overweight and obesity status may both increase the risk of overweight and obesity in offspring, with a significant interaction effect.

Repair impact of vibration exercise with different frequencies on articular cartilage of rats with early knee osteoarthritis and its JNK/NF-κB, SOX9 mechanisms / 中国应用生理学杂志

Objective: To investigate the repair effect and JNK/NF-κB,SOX9 mechanisms of vibration exercise with different frequencies on articular cartilage in rats with early knee osteoarthritis. Methods: Forty-eight adult male SD rats were randomly divided into six groups(n=8):model control group(MC),high frequency vibration group 1 (GP1,60 Hz),high frequency vibration 2 group (GP2,40 Hz),medium frequency vibration group (ZP,20 Hz),minor frequency group(DP,10 Hz)and normal control group(NC). Except for NC group,the rats in each group were made into early knee osteoarthritis model after six weeks of knee joint cavity injection of papain solution and 2% mixture l-cysteine on the 1st,4 th and 7th day. Each exercise group was subjected vibration to 40 minutes a day with amplitude of 2～5 mm and 5 days a week. Four weeks later, the articular cartilage of the lateral femoral condyle of the both back leg knee joints were detected by HE staining,serine O staining and Mankin scores for morphological observation. The expression levels of JNK,NF-κB p65 and Sox9 mRNA in articular cartilage of the medial femoral condyle were detected by RT-qPCR,and the protein expressions of JNK,NF-κB p65 and Sox9 were detected by Western blot. Results: Compared with the NC group,the Mankin score in other groups was significantly higher (P＜0.01). Compared with the MC group,the Mankin score of each vibration group was significantly lower(P＜0.05),the mRNA and protein expressions of JNK and NF-κB p65 in each vibration training group were significantly lower (P＜0.01),the expressions of Sox9 mRNA and protein in vibration training group were increased significantly (P＜0.01). Compared with the higher frequency group,the Mankin score,the mRNA and protein expressions of JNK and NF-κB p65 of lower frequency group were significantly lower (P＜0.05 or P＜0.01). But the expressions of Sox9 mRNA and protein were significantly higher (P＜ 0.05 or P＜0.01). Conclusion: Vibration exercise of different frequencies may present varying degrees of cartilage repair impact in rats with early knee osteoarthritis,and the cartilage repair by low-frequency vibration training is better than that by high-frequency vibration. This can be one of the mechanisms on controlling collagen synthesis by down-regulating JNK/NF-κB expression and increasing SOX9 activity of OA articular cartilage.

Quantitative evaluation of global left ventricular myocardial work in patients with hepatitis B cirrhosis by pressure-strain loop / 中华肝脏病杂志

Objective: To quantitatively evaluate myocardial work in patients with hepatitis B cirrhosis by using left ventricular pressure-strain loop. Methods: 70 cases with hepatitis B cirrhosis who were hospitalized in Henan Provincial People's Hospital from March to December 2020 were selected as the study group. Patients were divided into three subgroups according to the Child-Pugh score of liver cirrhosis (Child-Pugh class A, B, and C groups: 25, 25, and 20 patients, respectively). At the same time, 25 healthy volunteers were included as the control group. Global longitudinal strain (GLS), global myocardial work index (GWI), global work efficiency (GWE), global constructive work (GCW), and global wasted work (GWW) were obtained by applying pressure-strain loops. The differences were analyzed and compared among the four groups parameters. Results: Compared with the control group, the Child-Pugh class A group had decreased GLS, while Child-Pugh class B and C had decreased GLS, GWI, GWE, GCW, and increased GWW, and the differences were statistically significant (P<0.05). Compared with Child-Pugh class A group, Child-Pugh class B group had decreased GLS, GWE, and increased GWW, while Child-Pugh class C group had decreased GLS,GWI, GWE, GCW, and increased GWW, and the differences were statistically significant (P<0.05). Compared with Child-Pugh class B group, Child-Pugh class C group had decreased GLS, GWI, GWE, GCW, and increased GWW, and the differences were statistically significant (P<0.05). Conclusion: The pressure-strain loop can detect early myocardial dysfunction, and has a certain value in the diagnosis, treatment and prognosis evaluation of myocardial function changes in patients with hepatitis B cirrhosis.

Effects of plasma lipopolysaccharide changes on platelet release of vascular endothelial growth factor and thromobospondin-1 in patients with cirrhotic portal hypertension after TIPS procedure / 中华肝脏病杂志

Objective: To investigate the effects of plasma lipopolysaccharide (LPS) concentration changes on platelet release of vascular endothelial growth factor (VEGF) and thrombospondin (TSP)-1 in patients with decompensated cirrhotic portal hypertension after transjugular intrahepatic portosystemic shunt (TIPS) procedure. Methods: 169 cases with cirrhotic portal hypertension were enrolled, of which 81 cases received TIPS treatment. LPS, VEGF, and TSP-1 concentrations with different Child-Pugh class in peripheral blood plasma of patients were measured. After pre-incubation of normal human platelets with different concentrations of LPS and stimulated by collagen in vitro, platelet PAC-1 expression rate, VEGF, and TSP-1 concentrations were detected. PAC-1 expression rate and the concentrations of LPS, VEGF and TSP-1 in peripheral blood plasma of patients before and after TIPS procedure were detected. The relationship between plasma LPS, VEGF and TSP-1 concentrations and Child-Pugh score changes in patients after TIPS procedure was analyzed. Statistical analysis was performed by t-test, one-way ANOVA or Pearson's rho according to different data. Results: Plasma LPS and TSP-1 concentrations were significantly higher in Child-Pugh class C patients than class A and B, but the concentration of plasma VEGF was significantly lower than class A and B (P < 0.01). In vitro experiments showed that concentration of LPS, TSP-1, and platelet PAC-1 expression rate was higher in the supernatant, but the difference in the concentration of VEGF in the supernatant was not statistically significant. Portal vein pressure and platelet activation were significantly decreased (P < 0.01) in patients after TIPS procedure. Portal venous pressure, platelet activation, plasma LPS, and TSP-1 levels were significantly decreased continuously, while VEGF levels were significantly increased continuously after TIPS procedure. Plasma LPS concentration was positively correlated with TSP-1 concentration (r = 0.506, P < 0.001), and negatively correlated with VEGF concentration (r = -0.167, P = 0.010). Child-Pugh score change range was negatively correlated with change range of plasma VEGF concentration (r = -0.297, P = 0.016), and positively correlated with change range of plasma TSP-1 concentration (r = 0.145, P = 0.031) after TIPS. Conclusion: Portal venous pressure gradient, plasma LPS concentration and corresponding platelet activation was decreased in cirrhotic portal hypertension after TIPS procedure, and with TSP-1 reduction and VEGF elevation it is possible to reduce the liver function injury caused by portal venous shunt.

Differences of Gut Microbiota Diversity between Patients with Abdominal Aortic Aneurysm and Atherosclerosis / 中国医学科学院学报

Objective To investigate the differences of gut microbiota between patients with abdominal aortic aneurysm and atherosclerosis.Methods From December 2018 to June 2019,20 fresh stool samples were collected respectively from the patients with abdominal aortic aneurysm and atherosclerosis treated at the Department of Vascular Surgery,Peking Union Medical College Hospital.The 16S rDNA high-throughput sequencing was employed to compare the composition,abundance,and α and β diversities of gut microbiota between the two disease groups,and further determine the significantly differential genera.Results The two groups had great similarities in the composition of gut microbiota.There was no statistical difference in α diversity.Although β diversity did not have statistically significant difference,certain microbial taxa showed differences between the two groups.The LEfSe demonstrated that the abdominal aortic aneurysm group had higher relative abundance of

Expression of PD-L1 in peripheral blood T cells and monocytes of patients with gastric cancer before and after surgery and its clinical significance / 中国免疫学杂志

Objective:To investigate the expression of PD-L1 in peripheral blood with gastric cancer patients and its clinical significance.Methods:Peripheral blood samples were collected from 44 gastric cancer patients (before and after the surgery) and 18 healthy subjects.The expression of PD-1 and PD-L1 on CD3+CD4+T,CD3+CD8+T cells and CD14+monocytes was detected by flow cy-tometry.Results:The expression of PD-L1 on CD14+monocytes of the gastric cancer patients was significantly higher than that of the healthy control[(29.2±16.7)% vs (17.5±9.7)%,P=0.007 3],while there was no statistical difference on CD4+T cells and CD8+T cells[(11.1±6.4)% vs(9.8±5.6)%,P=0.453 2;(13.9±12.0)% vs(12.0±7.1)%,P=0.558 9].The expression of PD-L1 on CD4+T cells and CD8+T cells in patients with gastric cancer was significantly higher than that before surgery[(15.8 ± 8.2)% vs (11.1±6.4)%,P=0.001 5;(22.5±13.3)% vs(13.9±12.0)%,P=0.000 2].However,no significant change was found on CD14+mononuclear cells[(33.8±17.3)% vs (29.2±16.7)%,P=0.082 8].There was no significant difference in the expression of PD-1 on CD4+T and CD8+T cells before and after surgery[(25.6 ±9.9)% vs (26.9 ±8.9)%,P=0.505 5;(26.5 ±14.6)% vs (29.9 ± 10.4)%,P=0.118 7].Conclusion:PD-L1 can be used as an effective marker to monitor the immune function and prognosis of patients with primary gastric cancer.

Research Progress on BK Virus Infection after Hematopoietic Stem Cell Transplantation--Review / 中国实验血液学杂志

BK virus infection is one of the common complications after hematopoietic stem cell transplantation(HSCT), which is also one of the reasons of the hemorrhagic cystitis．In recent years, although there are more studies of the risk factors related with human BK virus infection after hematopoietic stem cell transplantation, the risk factors related with BKV-associated hemorrhagio cystitis(BKV-HC) remain to be elucidated. Diagnosis of BK virus infection is mainly based on quantitative PCR of blood or urine. An effective strategy for treatment of these patients is the adoptive transfer of T lymphocytes specific to virus-associated antigens. In this review, the progressis of diagnosis and treatment of BK virus infection after hematopoietic stem cell transplantation are briefly summarized.

Tetracycline hydrochloride induces the osteogenic differentiation of rat bone marrow mesenchymal stem cells / 中国组织工程研究

BACKGROUND:Tetracycline hydrochloride not only promotes the proliferation of bone marrow mesenchymal stem cells (BMSCs),but also has a strong bone activity.Studies on the osteogenic differentiation of BMSCs induced by tetracycline hydrochloride will provide a new cell source for bone tissue engineering.OBJECTIVE:To observe the induction and differentiation activity of BMSCs into osteoblasts cultured by tetracycline hydrochloride in vitro.METHODS:BMSCs were separated and expanded by whole bone marrow adherent method and identified by cell morphology and BMSCs cell markers CD34,CD45,CD90,CD29.Passage 3 BMSCs were collected and cultured with tetracycline hydrochloride (experimental group) or cultured in L-DMEM containing 10％ fetal bovine serum (control group).Osteogenic induction and differentiation activity of BMSCs cultured by tetracycline hydrochloride were detected by alkaline phosphatase activity detection,collagen I and osteocalcin immunohistochemistry staining,alizarin red staining of mineralized calcium nodules,and detection of collagen I and osteocalcin gene expression by RT-PCR.RESULTS AND CONCLUSION:Tetracycline hydrochloride continuously promoted alkaline phosphatase activity in the BMSCs,significantly different from that in the control group.After 21 days of culture,positive expression of collagen I and osteocalcin proteins,red calcium nodules shown by alizarin red staining,and mRNA expression of collagen I and osteocalcin were observed in the experimental group,while the negative expression was found in the control group.In conclusion,tetracycline hydrochloride has a significant role to promote the osteogenic differentiation of BMSCs.

Compound polymyxin B ointment combined with desonide cream for the treatment of subacute or chronic ;eczema:a multicenter, randomized, double-blind, parallel-group, controlled clinical study / 中华皮肤科杂志

Objective To evaluate the clinical efficacy and safety of compound polymyxin B ointment combined with desonide cream for the treatment of subacute or chronic eczema. Methods A multicenter, randomized, double?blind, parallel?group, controlled clinical study was conducted. Totally, 144 patients with subacute eczema and 144 patients with chronic eczema were enrolled into this study, and both randomly and equally divided into the test group and control group. The test group and control group firstly topically applied compound polymyxin B ointment and its vehicle respectively, then both topically applied desonide cream 3 hours later. The drugs or vehicle were applied twice a day in all the patients. Patients′ symptoms and signs (including degree of itching, inflammation, erosion/exudation and infiltration/thickening, as well as area of target lesions) were evaluated, and the time to onset and duration of itching?alleviating effect were recorded. The clinical efficacy and safety of treatments were analyzed and compared between the test group and control group. Results The total symptom and sign scores significantly decreased to different extents on days 7 and 14 in the test group(subacute eczema patients:6.09 ± 2.78 and 3.68 ± 3.18 vs. 13.44 ± 1.66; chronic eczema patients: 6.56 ± 2.68 and 4.38 ± 3.27 vs. 12.96 ± 1.16)and control group(subacute eczema patients:8.26 ± 3.17 and 5.28 ± 4.05 vs. 13.60 ± 1.75;chronic eczema patients: 8.84 ± 2.90 and 6.25 ± 3.78 and vs. 12.64 ± 1.18)compared with those at baseline. Moreover, the total symptom and sign score of patients with subacute or chronic eczema was significantly lower in the test group than in the control group on days 7 and 14(all P<0.05). A significant increment was observed in the degree of decrease in scores for itch, infiltration/thickening in patients with subacute eczema in the test group compared with that in the control group(all P<0.01), as well as in scores for itch, infiltration/thickening and area of target lesions in patients with chronic eczema in the test group compared with those in the control group (all P < 0.05). In addition, patients with subacute eczema in the test group showed significantly shorter onset and longer duration of itching?alleviating effect than those in the control group(both P<0.05). The time to onset of itching?alleviating effect was also significantly shorter in patients with chronic eczema in the test group than in those in the control group(P<0.000 1), but there was no significant difference in the duration of it between the two groups of patients with chronic eczema. Clinicians and patients were both more satisfied with therapeutic effects in the test group than in the control group(all P<0.05). Conclusions Topical compound polymyxin B ointment can increase the efficacy of topical desonide cream for the treatment of subacute or chronic eczema, especially subacute eczema. Compound polymyxin B ointment also shows a favorable therapeutic effect on itching and infiltration/thickening in patients with eczema.

Effect of covered stent length in portal and hepatic veins on long-term clinical efficacy of transjugular intrahepatic portosystemic shunt / 南方医科大学学报

<p><b>OBJECTIVE</b>To evaluate the effect of the length of covered stents in the portal and hepatic veins on long-term clinical efficacy of transjugular intrahepatic portosystemic shunt (TIPS).</p><p><b>METHODS</b>We retrospectively reviewed 53 cases receiving TIPSs between January, 2008 and December, 2011. All the shunts were created with Fluency stents (8 mm in diameter). Bare metal grafts of the same diameter were implanted to extend the length in the portal and hepatic veins as deemed necessary according to angiographic images. The primary patency, hepatic encephalopathy and patient survival were evaluated during the follow up. The length of the covered stents within the hepatic vein (X1) and in the portal vein (X2), and the total length of stents placed in the hepatic vein (X3) and the portal vein (X4) were measured and their effects on primary patency and the patients'outcomes were evaluated.</p><p><b>RESULTS</b>The procedures were completed successfully in all the patients and the mean portosystemic pressure decreased from 29.80∓4.83 mmHg to 19.00∓3.92 mmHg (t=13.44, P<0.01) after the procedure. The patients were followed up for a median of 64 months (3 to 89 months, 39 months on average). Hepatic encephalopathy occurred in 23% (12/53) of the patients after TIPS. Shunt dysfunction occurred in 16 cases, and the cumulative primary patency rates at 1 to 5 years were 83%, 75%, 63%, 62%, and 54%, respectively. The cumulative survival rates of the patients at 1 to 5 years were 79%, 72%, 72%, 69%, and 69%, respectively. Cox proportional regression analysis showed a significant association between the length of covered-stent in the hepatic vein and the primary patency (OR=0.42, P<0.01), and there was a significant association between the length of stent in the portal vein and the patient survival. No significant correlation was found between these parameters and hepatic encephalopathy.</p><p><b>CONCLUSION</b>Increasing the length of the covered stent in the hepatic vein and decreasing the stent length in the portal vein can improve the primary patency and the patient survival receiving TIPS.</p>

Research on effect of static elastography on the elastic modulus of normal breast tissue / 中国医学装备

Objective:To investigate the effects of static ultrasound elastography on the elastic modulus of normal breast tissue.Methods: (1)Fifteen cases of normal breasts was tested by static ultrasound elastography at the same locations. Intercepted two pictures each time with one stress-free and the other compressed the maximum amount. For these two cases we measured the breast thickness and calculated the minimum stretch ratios(λ). (2)Fifty breasts with no breast nodules were prospectively enrolled in the study. Intercepted two pictures each time with one stress-free and the other compressed to the minimum stretch ratios(λ). For these two cases we measured the Elastic modulus (E0, Em, kPa). Calculate the elastic modulus change ratio (Rm/0).Results: (1)The minimum stretch ratio caused by static ultrasound elastography was 0.74±0.07. (2)The elastic modulus change ratio of static ultrasound elastography was 4.38±1.72. Conclusion: The normal operation of static ultrasound elastography caused 74 percent deformation in normal breast tissue. There was 4.38 times elastic modular increasing caused by 74 percent deformation in normal breast tissue.

Evaluation of the relationship between pulse wave velocity and carotid atherosclerosis by UltraFast imaging / 中华超声影像学杂志

Objective To assess the relationship between pulse wave velocity(PWV) and carotid atherosclerosis by UltraFast imaging.Methods 476 cases from Medical Examination Center of Beijing Friendship Hospital were enrolled in this study.According to intima-media thickness(IMT) of carotid artery,all subjects were divided into two groups:IMT without thickening group (G0) of 283 cases and IMT thickening group (G1) of 193 cases.Through UltraFast imaging,carotid artery PWV was measured,including the PWV at the beginning of the systole(BS) and the PWV at the ending of the systole(ES).Carotid IMT and plaque situation were recorded under gray-scale ultrasound.BS and ES were compared between the two groups.Spearman rank correlation was used to analyse the correlation between IMT of carotid artery and BS,between IMT of carotid artery and ES.Two independent samples t test to compare BS,ES between the two groups.Results BS of G1 and G0 were (6.03 ± 1.33)m/s and (5.51 ± 1.13)m/s,t =-4.571,P =0.000;ES of G1 and G0 were (8.42 ± 2.13)m/s and (7.34 ± 2.02) m/s,t =5.619,P =0.000.BS and ES of G1 were larger those of G0 respectively.BS (r =0.192,P =0.000) and ES (r =0.249,P =0.000) were correlated with the IMT of carotid artery.Conclusions Ultrafast imaging technique can quickly measure the carotid artery PWV.BS and ES of carotid artery can be quick,convenient,safe,noninvasive parameters for evaluating carotid atherosclerosis.

Expressions of IL-10, IL-23 and CD86 in lesions of epidermodysplasia verruciformis / 中华皮肤科杂志

Objective To measure the expressions of IL-10, IL-23 and CD86 in lesions of epidermodysplasia verruciformis (EV), and to explore the relationship between cellular immune abnormality and EV pathogenesis. Methods Immunohistochemistry was used to measure the expressions of IL-10, IL-23 and CD86 in tissue samples from 10 patients with EV and 10 normal human controls. Results Three cytokines were observed in all the samples of EV, with the expression score ranging from 3 to 6 and expression intensity from moderate to high. However, of the control specimens, only 1 was positive for IL-10 with the expression score being 3, and expression intensity being moderate. Conclusion The pathogenesis of epidermodysplasia verruciformis may be correlated with the expression abnormality of some cytokines secreted by keratinocytes.

Effect of branched-chain amino acids, valine, isoleucine and leucine on the biosythesis of bitespiramycin 4"-O-acylspiramycins

Bitespiramycin, a group of 4"-O-acylated spiramycins with 4"-O-isovalerylspiramycins as the major components, was produced by recombinantspiramycin-producing strain Streptomyces spiramyceticus harboring a 4"-O-acyltransferase gene. The experiment was initially performed in synthetic medium with 0.5 g l-1 Valine, Isoleucine or Leucine feeding at 36 h cultivation. When valine was fed, the biological titer of bitespiramycin was 45.3 percent higher than that of the control group, but the relative content of total isovalerylspiramycin components decreased by 22.5 percent. In the case of ilecine, the biological titer of bitespiramycin and the total isovalerylspiramycins alone were 85 percent and 72.1 percent of the control group, respectively. In contrast, the relative content of other acylated spiramycins increased by 54.41 percent. However, leucine feeding increased the relative content of total isovalerylspiramycins by 41.9 percent while the biological titer of bitespiramycin was nearly equal to that of the control group. The improvement effect of leucine on the biosynthesis of isovalerylspiramycins was further confirmed by feeding of 2.0 g l-1 leucine to the culture with complex medium. After batch feeding with a total amount of 2.0 g l-1 leucine to the culture from 70 h to 90 h, the biological titer of bitespiramycin was almost unreduced, and the final relative content of total isovalerylspiramycins increased from 31.1 percent to 46.9 percent.

Expressions of CD1a and CD83 of Langerhans cells in the local lesions of epidermodysplasia verruciformis patients / 中国医学科学院学报

<p><b>OBJECTIVE</b>To investigate the expressions of CD1a and CD83 of Langerhans cells (LC) in the lesions of epidermodysplasia verruciformis (EV) patients.</p><p><b>METHODS</b>We used immunohistochemical method to detect the expressions of CD1a and CD83 in the lesions of 10 patients with EV lesions and in the skins of 10 normal subjects.</p><p><b>RESULTS</b>No CD83 + LCs was detected in all EV patients and normal controls, but CD1a + LC was found in all cases. The quantity of CD1a + LCs in the lesions of EV patients was significantly lower than that in the normal skin (P < 0.01); furthermore, the distribution of LCs in EV lesions was uneven.</p><p><b>CONCLUSION</b>The functions of LCs may be inhibited in EV patients.</p>

Pathogenesis of human papillomavirus infection in patients with epidermodysplasia verruciformis / 中国医学科学院学报

Epidermodysplasia verruciformis (EV), a rare inherited disease, is believed to be associated with human papillomavirus (HPV) infection. EVER1/2 genes, dendritic cells, T lymphocytes, and the biological characteristics of HPV itself may play roles in the pathogenesis of HPV infection.

Phase transfer catalyzed bioconversion of penicillin G to 6-APA by immobilized penicillin acylase in recyclable aqueous two-phase systems with light/pH sensitive copolymers / 南方医科大学学报

Immobilized penicillin acylase was used for bioconversion of penicillin PG into 6-APA in aqueous two-phase systems consisting of a light-sensitive polymer PNBC and a pH-sensitive polymer PADB. Partition coefficients of 6-APA was found to be about 5.78 in the presence of 1% NaCl. Enzyme kinetics showed that the reaction reached equilibrium at roughly 7 h. The 6-APA mole yields were 85.3% (pH 7.8, 20 degrees C), with about 20% increment as compared with the reaction of single aqueous phase buffer. The partition coefficient of PG (Na) varied scarcely, while that of the product, 6-APA and phenylacetic acid (PA) significantly varied due to Donnan effect of the phase systems and hydrophobicity of the products. The variation of the partition coefficients of the products also affected the bioconversion yield of the products. In the aqueous two-phase systems, the substrate, PG, the products of 6-APA and PA were biased in the top phase, while immobilized penicillin acylase at completely partitioned at the bottom. The substrate and PG entered the bottom phase, where it was catalyzed into 6-APA and PA and entered the top phase. Inhibition of the substrate and products was removed to result in improvement of the product yield, and the immobilized enzyme showed higher efficiency than the immobilized cells and occupied smaller volume. Compared with the free enzyme, immobilized enzyme had greater stability, longer life-time, and was completely partitioned in the bottom phase and recycle. Bioconversion in two-phase systems using immobilized penicillin acylase showed outstanding advantage. The light-sensitive copolymer forming aqueous two-phase systems could be recovered by laser radiation at 488 nm or filtered 450 nm light, while pH-sensitive polymer PADB could be recovered at the isoelectric point (pH 4.1). The recovery of the two copolymers was between 95% and 99%.

The influence of controlling redox potential on ethanol production by Saccharomyces cerevisiae / 生物工程学报

Redox electrode was used to control redox potential at four different levels (-50 mV, -100 mV, -150 mV, - 230mV) for the study of ethanol fermentation. The result showed that there was notably influence on the yield of ethanol, the formation of glycerol, the secretion of organic acid, biomass and the death of cell by controlling redox potential at different levels. For example: the biomass of ORP at -50 mV was 1.26, 1.86, 2.59 times higher than ORP at -100 mV, -150 mV, -230 mV respectively, the final glycerol concentration was 1.2, 1.1, 1.7 times higher but final ethanol concentration was 0.87, 0.49, 0.51 times lower compared to the latest three ORP control level. And take biomass, ethanol yield, glycerol concentration, and unconsumed glucose into consider, we get the conclusion that it is very favorable for ethanol fermentation by control ORP at 150 mV. So it give us a apocalypse that we can use redox electrode to control the ethanol fermentation exactly on bioreactor scale.