In industrial application of NAD(P)H-dependent dehydrogenases, NAD(H) has the advantages over NADP(H) in higher stability, lower price and wider recycling system. Recently, a meso-2,6-diaminopimelate dehydrogenase from Symbiobacterium thermophilum (StDAPDH) has been found to be a useful biocatalyst for the production of D-amino acids, but it requires NADP(H) as co-enzyme. To switch the co-enzyme specificity from NADP(H) to NAD(H), we studied the effect of Y76 on the co-enzyme specificity of StDAPDH, because the crystal structural analysis indicated that residue Y76 is near the adenine ring. The mutation of Y76 exerted significant effect on the co-enzyme specificity. Furthermore, the double mutant R35S/R36V significantly lowered the specific activity toward NADP+, and the combination of R35S/R36V with some of the Y76 mutants resulted in mutant enzymes favorable NAD+ over NADP+. This study should provide useful guidance for the further development of highly active NAD(+)-dependent StDAPDH by enzyme engineering.
Amino Acid Oxidoreductases ; chemistry ; Amino Acids ; Clostridiales ; enzymology ; Mutation ; NAD ; NADP ; Substrate Specificity

ObjectiveTo evaluate the effect of N-acetylcysteine (NAC) on alleviating hepatorenal damage caused by combined chemotherapy using cisplatin-based regiments in elderly patients. MethodsAll 40 elderly patients with malignant tumors were randomly divided into AB and BA group in cross-over pattern. In AB group, combination of chemotherapy and NAC was administrated for 10 days first, and then combination of chemotherapy, carnine and vitamin C was given for 10 days. In BA group, combination of chemotherapy, earnine and vitamin C was administrated for 10 days first, and then combination of chemotherapy and NAC was given for 10 days, a cycle was 21 days. The hepatorenal damage degree was observed and the curative effect of NAC on hepatorenal damage was evaluated. ResultsThere were no differences in the levels of alanine aminotransferase(ALT), aspartate aminotransferase(AST) and serum creatinine(Cr) between pre chemotherapy and post chemotherapy in A cycle[(25.32±5.23) U/L vs. (29.18±5.43) U/L,(29.21±6.51)U/L vs. (32.37±7. 13)U/L, (89.87±19.56)Mmol/L vs. (95.22±20. 60)μmol/L,all P>0. 05] . In B cycle, the levels of ALT,AST and Cr were (56.76±5.53) U/L, (48.83±6.64)U/L and (137.33±21.16)μmol/L post chemotherapy, respectively, which were evidently higher than pre chemotherapy[(26.19 ± 5.51) U/L, (29.95±6.56) U/L and (88.66±18.27)μmol/L,respectively] (all P<0.01) . ConclusionsNAC has better preventive and therapeutic effects on hepatorenal damage caused by the chemotherapeutic drugs in elderly patients with malignant cancer.

Objective Currently, the prefabricated flap is used for reconstructing the post-burn scar in head and face.The aim is to analyze the nature of the post-op edema in the prefabricated flaps, to determine whether it is lymphedema, and to study the prognosis of the edema.Methods From January, 2011 to March, 2015, 18 cases of post-operation edema in superficial temporal fascia prefabricated flaps were studied and each case was followed for 5 months.We used ultrasound and indocyanine green (ICG) fluorescent imaging to study the nature of the edema.Apart from that, we monitored the recovery process of the post-operation edema by a) measuring the horizontal diameter of the flap by a tape, b) measuring the thickness of the flap by the ultrasound, c) monitoring the condition of edema by ICG and d) monitoring the reconstruction and recanalization of the lymphatic system by ICG.Results Pitting edema always occurred in the prefabricated flap from the first day after operation.These patients were diagnosed as mild lymphedema (7 cases), moderate lymphedema (10 cases), and severe lymphedema (1cases) by ultrasound and ICG florescent imaging.The degree of flap lymphedema improved gradually and it improved significantly from 3 days to 6 days post-op eration.The condition of flap lymphedema became stable from the 12 days post-operation.The fluorescence image of ICG showed that the stage of flap lymphedema improved from 3 weeks post-operation and the transportation capability of lymphatic vessels increased most from the 3 days to 6 days post-op eration.We also found lymphatic vessels reconnected from the 6 days post-operation and lymphatic system reconstructed following the direction to lymph nodes.We could discover the collecting lymphatic vessels from 2 months post-operation and the lymphatic system in prefabricated flap matured from 5 months post-operation.Conclusion The post-operation edema in the prefabricated flaps is lymphedema, the incidence rate of which is high.The lymphatic drainage system recovers in 6 days after the operation.It is reconstructed along the lymph nodes.The edema disappears in 2-3 weeks post-operation, the reconstructed the lymph system matures in 5 months.

Objective To evaluate the effectiveness of arthroscopically assisted percutaneous reduction and internal fixation with eannulated screws.Methods The fracture was reduced by closed manipulation or percutaneous leverage force by using the Kirschner wire.Then the patella was temporarily fixed by using a large size towel clamp or Kirschner wires.Under the guidance of knee arthroscopy,a micro-incision was made at the size of cannulated screw placement,the pilot holes were drilled at a proper depth,and the thread was configured.Two titanium screws were inserted parallelly.Results Following-up chekups for 4～24 months in 18 cases showed a satisfactory recovery of knee functions.According to the Bostman' standard,excellent effects were obtained in 16 cases and good effects in 2 cases.Conclusion Treatment of patellar fractures by percutaneous cannulated screw fixation under arrhroscope of- fered advantages of minimal invasion,accurate reduction,reliable fixation,and excellent recovery of joint functions.

OBJECTIVE To investigate CD25 expression in peripheral blood T lymphocytes from patients with chronic hepatitis B,and explore its significance in the pathogenesis of chronic hepatitis B.METHODS To detect CD25 expression in peripheral blood T lymphocytes of patients with chronic hepatitis B by means of flow cytometry.CD25 expression was observed in chronic hepatitis B patients.In the meantime,CD25 expression in T cells from severe chronic hepatitis or acute hepatitis B patients and asymptomatic carriers of HBV was also observed.RESULTS Varying degrees of CD25 were expressed in T cells from hepatitis B patients.The expression in CD3+ T and CD8+T cells was higher than that in CD4+T cells.CD25 expression in CD4+T was lower.The average of CD25 expression in CD3+T cells from patients with chronic hepatitis B,acute hepatitis B,and chronic severe hepatitis B and asymptomatic carriers of HBV was(2.92?0.13)%,(0.51?0.36)%,(1.60?0.07)%,and(0.95?0.23)%,respectively.The average of CD25 expression in CD4+T cells from patients with chronic hepatitis B,acute hepatitis B and chronic severe hepatitis B and asymptomatic carriers of HBV was(2.58?0.50)%,(0.34?0.07)%,(1.45?0.02)%,and(0.83?0.13)%,respectively.CD3+T and CD4+T CD25 expression in patients with chronic hepatitis and,severe chronic hepatitis B was increased compared with that of acute hepatitis B patients and asymptomatic carriers of HBV.Compared with chronic severe hepatitis B,the expression of chronic hepatitis B was higher.CONCLUSIONS CD4+ CD25+T cells in chronic hepatitis B virus infection are increased compared with acute hepatitis,CD4+ CD25+T cells may be related to immune tolerance.

A surgical technique of lateral crus strut graft to correct the deformity of nostril contour and improve asymmetric nostril shape by autologous rib cartilage was reported. Thirty-five patients (20 males and 15 females), with a mean age of 19 years (range of 16-26 years) were included in this study. All of the patients suffered moderate to severe unilateral cleft lip nostril deformity and underwent surgical technique of lateral crus strut graft by autologous rib cartilage to correct the asymmetric nostril contour from 2010 to 2012. The views of the nostril contour on both sides were reviewed and some parameters were measured at different time points (preoperatively, and 3 months and one year postoperatively) including the long axis and short axis of the nostrils. The differences in nostrils including long axis, short axis, elliptical area and eccentricity on the both sides were compared at different time points. The differences in the long axis and eccentricity of the nostrils on the two sides were decreased significantly between the preoperative view and postoperative view (P<0.05). The surgical technique of lateral crus graft with autologous rib cartilage is effective to correct the abnormal nostril contour and improve the asymmetry for unilateral cleft clip patients.

Objective To evaluate the clinical efficacy of intravitreal ranibizumab injection and panretinal photocoagulation for neovascular glaucoma.Methods Totally 8 patients (40 eyes) with neovascular glaucoma in the First Affiliated Hospital of Zhengzhou university from January 2016 to October 2016 were collected in this study,and the patients were randomly divided into two groups according to the different treatments:trabeculectomy group (18 eyes),in which the patients were treated with intravitreal injection of ranibizumab + trabeculectomy + panretinal photocoagulation,and cyclophotocoagulation group (22 eyes),subjects undergoing cyclophotocoagulation + panretinal photocoagulation.All patients were followed up for 6 months.And there was no significant difference in the general data of the two groups (all P ＞ 0.05).Finally,variables including iris neovascularization,the best corrected visual acuity (BCVA),the preoperative and postoperative 1 month,3 months and 6 months intraocular pressure,the operation successful rate and complications in both groups were evaluated and compared.Results In the trabeculectomy group,1 week after treatment,neovascularization in all patients was disappeared,and 6 months of follow-up,a small amount of neovascular recurrence occurred;in the cyclophotocoagulation group,2 weeks after treatment,neovascularization disappeared in 18 eyes,decreased in 3 eyes,and did not change in 1 eye;additionally,6 months of follow-up,some eyes presented neovascularization recurrence.The postoperative BCVA in the trabeculectomy group was significantly higher than that before operation,and the difference was statistically significant (P =0.026),But there was no significant difference between preoperative and postoperative BCVA in the cyclophotocoagulation group (P =0.438).Preoperative BCVA in the trabecuiectomy group was significantly higher than that in the cyclophotocoagulation group,and the difference was statistically significant (P =O.039).The intraocular pressures of the both groups were decreased at 1 month,3 months and 6 months after operation,and the differences were statistically significant (all P ＜ 0.05).There was significant difference in the success rate of operation between the two groups (P =0.047).The efficacy of the trabeculectomy group was better than that of the cyclophotocoagulation group.The incidence of complications in the trabeculectomy group was lower than that in the cyclophotocoagulation group,and the difference was statistically significant (P =O.024).Conclusion It is safe and effective for intravitreal ranibizumab injection + trabeculectomy + panretinal photocoagulation in the treatment of iris neovascularization,of which the clinical efficacy is better than cyclophotocoagulation + pamretinal photocoagulation.

OBJECTIVETo explore the incidence of dementia among elderly people in Xi'an and its related risk factors.

METHODSSubjects that had been studied on the prevalence of dementia were follow-up, and the incidence of dementia, Alzheimer disease (AD) , and vascular dementia (VD) were counted by person-years. The clinical diagnosis on dementia,AD and VD were based upon the 3rd Edition of Diagnostic and Statistical of Manual of Mental Disorder, Revised version (DSM-III-R) and NINCDS-ADRDA criteria.

RESULTS2197 subjects of non-dementia being identified in 1998, were re-surveyed in 2001. Out of them, 47 new cases of dementia including 37 cases of AD and 8 cases of VD were identified, with an annual incidence rates of dementia, AD and VD as 0.68%, 0.54% and 0.12% among those of 55 years and over and 0.89%, 0.69% and 0.17% in 65 years and over, respectively. Analysis from single factor logistic regression showed that age and education but not gender were closely related to the occurrence of AD. On the contrary, age, hypertension and stroke were closely related to the occurrence of VD.

CONCLUSIONThe incidence of dementia in the "Xi' an cohort" was similar to that being reported from other countries. AD and VD were an age-related diseases but education seemed to have had great protective effect while lack of formal education served as risk factor to AD.

Age Distribution ; Aged ; Aged, 80 and over ; China ; epidemiology ; Dementia ; classification ; epidemiology ; Educational Status ; Female ; Follow-Up Studies ; Humans ; Logistic Models ; Male ; Middle Aged ; Multivariate Analysis ; Risk Factors ; Sex Distribution

To assay the influence of dendritic cells(DCs)on the function of anti-infective immunity to Penicillium marneffei.DCs were generated from peripheral blood mononuclear cells(PBMC)and pulsed with Penicillium marneffei yeasts.DCs morphology was observed by the inverted microscope and cell surface markers of DCs were analyzed by flow cytometry.The concentrations of IL-12p70 were detected by ELISA. Mixed lymphocyte reaction was performed to assay the proliferation of T cells.The mRNA of CCR7 and CXCR4 were detected by the Real-time PCR quantifications.The acquired DCs exhibited irregular appearance and numerous long dendrites under light microscope.DCs and Penicillium marneffei yeasts were co-cultured for 24 h,numerous yeasts were observed inside the cells;an enhanced expression of the cell sur-face markers CD86、CD83、HLA-DR and CD40 were demonstrated;the expression of CCR7 and CXCR4 mRNA were also increased;the improved proliferation of T cells were observed in the mixed lymphocyte reaction.Yeasts-pulsed DCs secreted more IL-12p70 than that of non-pulsed,but less than that of LPS-pulsed DCs.DCs can engulf the Penicillium marneffei yeasts.When pulsed with Penicillium marneffei yeasts,DCs improved their expression of the co-stimulatory molecules and chemokine receptor CCR7、CXCR4,enhanced their capacity to process antigen.DCs play an important role in host defense against Penicillium marneffei infection.But the low level of the IL-12p70 production may lead to deficiency in the cell-mediated immunity against Penicillium marneffei.

OBJECTIVETo explore the underlying mechanism of electroacupuncture for anti-aging.

METHODSForty Sprague-Dawley rats (female and male take one half for each), 3-month old, were divided into a control group, a model group, a routine electroacupuncture group (current intensity, 1 mA) and a strong electroacupuncture group (current intensity, 4.5 mA), 10 rats in each group. The model of aged rats was established by D-galactose in the latter three groups. The acupoints of "Guanyuan" (CV 4) and "Zusanli" (ST 36) were used for electroacupuncture treatment, six times per week for 4 weeks. After that, the level of interleukin 6 (IL-6) in the serum, as well as the expression of neuropeptide Y mRNA (NPY mRNA) and IL-6 receptor (IL-6R) in the periventricular hypothalamic nucleus (PVN) were examined and compared between each group.

RESULTSIn comparison of the control rats, the model rats expressed with the lower level of NPY mRNA in PVN, higher levels of IL-6 in the serum and IL-6R in PVN, which is different from each other (P < 0.05). In both routine electroacupuncture group and strong electroacupuncture group, the level of NPY mRNA in PVN was up-regulated, in contrast, the levels of IL-6 in the serum and IL-6R in PVN were cut down, which were different from those of the model group (both P < 0.05). Furthermore, the therapeutic effect of the strong electroacupuncture group is different from that of the routine electroacupuncture group (P < 0.05).

CONCLUSIONElectroacupuncture at "Qiangzhuang" acupoints plays an active role to slow down the aging process on the sub-acute aged rats through regulating the function of neuro-immune system, and the therapeutic effect of strong stimulation is better than that of routine stimulation.

Acupuncture Points ; Aging ; immunology ; physiology ; Animals ; Disease Models, Animal ; Electroacupuncture ; Female ; Humans ; Hypothalamus ; metabolism ; Interleukin-6 ; genetics ; metabolism ; Male ; Neuroimmunomodulation ; Neuropeptide Y ; genetics ; metabolism ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Receptors, Interleukin-6 ; genetics ; metabolism