Ureaplasma urealyticum GrpE promotes mouse dendritic cell maturation and elicits Th1 immune responses / 中华微生物学和免疫学杂志

Objective:To investigate the effects of Ureaplasma urealyticum GrpE ( Uu-GrpE) on the maturation of dendritic cells and the polarization of T cells. Methods:Uu-GrpE was expressed and purified, and then identified by Western blot. The cytotoxicity of Uu-GrpE to mouse bone marrow-derived dendritic cells (BMDCs) was analyzed by LDH kit. After stimulating BMDCs with Uu-GrpE, the expression of costimulatory molecules, CD80, CD86 and major histocompatibility complex Ⅱ (MHCⅡ), on the surface of BMDCs was detected by flow cytometry, and ELISA was used to detect the cytokines such as IL-12p70, TNF-α, IL-1β and IL-6. CD4 + Na?ve T cells were isolated from mouse spleen tissues by magnetic beads. A co-culture system of BMDCs and Na?ve T cells was constructed to analyze the effects of GrpE-stimulated mature BMDCs (GrpE-BMDCs) on T cell proliferation and polarization towards Th1/Th2. Mice were immunized with GrpE-BMDCs through the tail vein, and the induced humoral and cellular immune responses were detected by ELISA and flow cytometry. Results:Uu-GrpE was successfully express and high purity BMDCs were isolated. Uu-GrpE could stimulate BMDCs to secrete cytokines such as IL-12p70, TNF-α, IL-1β and IL-6 without having cytotoxicity. Uu-GrpE significantly increased the expression of CD80 [mean flourscence indensity (MFI): (324.00±22.11) vs (91.03±10.95), P<0.01], CD86 [MFI: (1 176.00±51.39) vs (217.00±14.93), P<0.01] and MHCⅡ [MFI: (708.70±56.32) vs (185.70±16.77), P<0.01] on BMDCs. Compared to the GrpE-BMDCs only group and GrpE (boiled)-BMDCs+ T cell group, the GrpE-BMDCs+ T cell group showed significantly increased T cell proliferation [stimulation index: (7.25±0.21) vs(6.55±0.23) and (6.09±0.35), both P<0.05], and dramatically promoted T cell secretion of IL-2 and IFN-γ [IL-2: (145.60±14.67) pg/ml vs(55.92±3.12) pg/ml and (26.05±2.40) pg/ml, P<0.05 and P<0.01; IFN-γ: (267.20±37.80) pg/ml vs(146.70±20.65) pg/ml and(27.84±6.69) pg/ml, both P<0.05]. However, no significant change was observed in the expression of Th2-type cytokines. Moreover, the adoptive transfer of GrpE-BMDCs induced a Th1-type immune response. Conclusions:Uu-GrpE could stimulate the maturation and polarization of BMDCs. Moreover, it could induce Th1 immune response as a candidate protein vaccine for Ureaplasma urealyticum.

Antinociceptive effects of oleuropein in experimental models of neuropathic pain in male rats

Background@#The present investigation explored the therapeutic actions of oleuropein along with the possible signaling pathway involved in attenuating neuropathic pain in chronic constriction injury (CCI) and vincristine-induced neuropathic pain in male rats. @*Methods@#Four loose ligatures were placed around the sciatic nerve to induce CCI, and vincristine (50 μg/kg) was injected for 10 days to develop neuropathic pain.The development of cold allodynia, mechanical allodynia, and mechanical hyperalgesia was assessed using different pain-related behavioral tests. The levels of H2S, cystathionine-γ-lyase (CSE), cystathionine-β-synthase (CBS), orexin, and nuclear factor erythroid-2-related factor 2 (Nrf2) were measured in the sciatic nerve. @*Results@#Treatment with oleuropein for 14 days led to significant amelioration of behavioral manifestations of neuropathic pain in two pain models. Moreover, oleuropein restored both CCI and vincristine-induced decreases in H2S, CSE, CBS, orexin, and Nrf2 levels. Co-administration of suvorexant, an orexin receptor antagonist, significantly counteracted the pain-attenuating actions of oleuropein and Nrf2 levels without modulating H2S, CSE and CBS. @*Conclusions@#Oleuropein has therapeutic potential to attenuate the pain manifestations in CCI and vincristine-induced neuropathic pain, possibly by restoring the CSE, CBS, and H2S, which may subsequently increase the expression of orexin and Nrf2 to ameliorate behavioral manifestations of pain.

Antinociceptive effects of oleuropein in experimental models of neuropathic pain in male rats

Background@#The present investigation explored the therapeutic actions of oleuropein along with the possible signaling pathway involved in attenuating neuropathic pain in chronic constriction injury (CCI) and vincristine-induced neuropathic pain in male rats. @*Methods@#Four loose ligatures were placed around the sciatic nerve to induce CCI, and vincristine (50 μg/kg) was injected for 10 days to develop neuropathic pain.The development of cold allodynia, mechanical allodynia, and mechanical hyperalgesia was assessed using different pain-related behavioral tests. The levels of H2S, cystathionine-γ-lyase (CSE), cystathionine-β-synthase (CBS), orexin, and nuclear factor erythroid-2-related factor 2 (Nrf2) were measured in the sciatic nerve. @*Results@#Treatment with oleuropein for 14 days led to significant amelioration of behavioral manifestations of neuropathic pain in two pain models. Moreover, oleuropein restored both CCI and vincristine-induced decreases in H2S, CSE, CBS, orexin, and Nrf2 levels. Co-administration of suvorexant, an orexin receptor antagonist, significantly counteracted the pain-attenuating actions of oleuropein and Nrf2 levels without modulating H2S, CSE and CBS. @*Conclusions@#Oleuropein has therapeutic potential to attenuate the pain manifestations in CCI and vincristine-induced neuropathic pain, possibly by restoring the CSE, CBS, and H2S, which may subsequently increase the expression of orexin and Nrf2 to ameliorate behavioral manifestations of pain.

Research progress of early optimal metabolic therapy for diabetic retinopathy / 中华眼底病杂志

Diabetic retinopathy (DR) is one of the main cause of severe visual impairment in diabetic patients. Most of the existing treatments are aimed at patients with intermediate and advanced stages of vision impairment, and are invasive treatments with limited effects. Therefore, it is urgent for non-invasive new therapies and new targets to prevent the risk of DR or delay the progress of DR. Early optimization of metabolic therapies, which are strict control of blood glucose, blood pressure and blood lipid in the early stage of diabetes, may prevent or improve potential and reversible microangiopathy, however, there is still a lack of comprehensive and effective drug targeted therapy and unified clinical application standards. Therefore, this study summarizes the application of new hypoglycemic drugs and some antihypertensive and lipid-lowering drugs in the prevention and treatment of DR in recent years, in order to provide some reference for the clinical early prevention and treatment of this disease.

Study on Varieties,Indications and Usage Features of Tibetan Medicine Preparations Based on Drug Stan-dards / 中国药房

OBJECTIVE:To study varieties,indications and usage features of Tibetan medicine preparations,and provide refer-ence for the clinical treatment and new drug development for Tibetan medicine. METHODS:Tibetan medicine preparations in offi-cial standards were collected,variety features(formula scale,license number,pharmaceutical enterprise,name and dosage form, herbal medicine number),action features(indication name,clinical application)and medicine features(category and quantity,me-dicinal part,commonly used drug,frequency,three fruitsuse feature) were summarized. RESULTS:Totally 458 preparations were included,including 18 recorded in Chinese Pharmacopoeia (part 1,2015 edition),200 recorded in Pharmaceutical Stan-dards of the Ministry of Health of China(Tibetan medicine,1995 edition),240 recorded in Tibetan Medicine Standards(six prov-inces). 129 had obtained 430 license numbers,from 52 pharmaceutical companies;the prearations were mainly named byherbal medicine+principal medicine+dosage formprincipal medicine+dosage formandindication+dosage form. Dosage forms had powder,pill,cream,oil,syrup and wine; the number of herbal medicine was(13.81±13.28). The Tibetan preparations were com-monly used in the clinical treatment of diseases of the digestive system,respiratory system,genitourinary system,circulatory sys-tem,infectious and parasitic diseases,etc. 442 medicines had been used,including 297 herbal medicines,70 animal medicines, 47 mineral medicines and other 28 medicines. The common medicinal parts were seed or fruit,root or rhizome,whole grass,flow-er,stem,over-ground part,tuber or bulb,etc. The top 10 frequency of medicines were as follows as Terminalia chebula,Cartha-mus tinctorius,Aucklandia lappa,Amomum kravanh,Phyllanthus emblica,Piper longum,Inula racemosa,Punica granatum, Moschus berezovskii,Adhatoda vasica;and 19% preparations contained three fruits(T. chebula,P. emblica,Terminalia bellirica). CONCLUSIONS:Tibetan medicine preparations have rich varieties,reasonable herbal medicines,more solid preparations,widely clinic application,contain more herbal drugs and commonly usethree fruits,while fewer preparations have obtained license number.

The prevalence and prognostic value of anemia in male and female patients with chronic systolic heart failure / 中国医师杂志

Objective To investigate the prevalence and prognostic value of anemia in male and female patients with chronic systolic heart failure (CSHF).Methods Data of in-hospital patients with CSHF were investigated between 2000 and 2010 from 12 hospitals in Hubei Province.Patients were divided into normal hemoglobin (Hb) group,mild anemia group,moderate anemia group,severe and extreme anemia group.According to age,body mass index (BMI) and correction of glomerular filtration rate (GFRc),patients were divided into several subgroups,respectively.Multivariate logistic regression was performed to determinate the associated factors with anemia.Kaplan-Meier curve was performed to evaluate the difference in all-cause mortality in male and female patients with anemia.Univariate and multivariate Cox proportion hazard analysis was performed to determinate the risk of all-cause mortality among different anemia group in male and female patients.Results A total of 16681 patients were enrolled.Anemia accounted for 23.79％ and 27.29％,separately,in male and female patients with CSHF.BMI and GFRc were related to anemia in both male and female patients with CSHF,while only age was related to anemia for female patients with CSHF.The hazard ratio of all-cause mortality was 1.08 (P ＜ 0.01),1.13 (P ＜ 0.O1) and 1.02 (P =0.74),respectively,for all,male and female anemia patients with CSHF,compared to normal Hb group.Compared to normal Hb group,the hazard ratio of mild anemia group,moderate anemia group,severe and extreme anemia group was 1.05 (P =0.14),1.20 (P ＜0.01) and 1.36 (P ＜0.01),respectively,for all CSHF patients;1.11 (P ＜ 0.01),1.35 (P ＜ 0.01) and 1.37 (P ＜ 0.01),respectively,for male;0.96 (P=0.48),1.08 (P=0.40) and3.47 (P＜0.01),respectively,for female.Conclusions Compared to male,female patients suffer higher prevalence of anemia in patients with CSHF.There is a significant difference in risk factors and prognosis of anemia between male and female patients with CSHF.

Analysis on efficacy of local incision continuous local ropivacine infiltration anesthetic analgesia after total knee arthroplasty / 重庆医学

Objective To investigate and evaluate the effectiveness and safety of continuous local incision infiltration anesthetic analgesia after total knee arthroplasty(TKA).Methods Forty-eight patients with initial unilateral TKA in the Affiliated Hospital of Traditional Chinese Medicine of Southwest Medical University from August 2015 to May 2016 were allocated to three groups according to systematic random sampling methods:16 cases in the control group received continuous local incision infiltration anesthesia and femoral nerve block analgesia,16 cases received continuous femoral nerve block analgesia after TKA(CFNB) and other 16 cases received local ropivacaine continuous local incision infiltration anesthesia analgesia(CWI).The preoperative general situation,visual analogue scale (VAS) score of operative site in movement and rest on postoperative 1-3 d,postoperative early function recovery and postoperative complication were compared among 3 groups.Results All cases were followed up.There was no statistically significant difference in the general situation postoperative complications among 3 groups(P＞0.05).the VAS score under movement status on postoperative 1-3 d and rest status in the CWI group and CFNB group were similar,which were lower than those in the control group,the difference was statistically significant(P＜0.05);the postoperative early function recovery in the CWI group was superior to that in the control group and CFNB group.Conclusion local incision infiltration anesthetic analgesia after TKA can relief postoperative pain,facilitate patient's early function exercise and rehabilitation,and improves patient's satisfaction.

Efectos beneficiosos de la simpatectomía renal sobre el remodelado vascular pulmonar en la hipertensión arterial primaria experimental / Beneficial effects of renal denervation on pulmonary vascular remodeling in experimental pulmonary artery hypertension

Introducción y objetivos. La activación tanto del sistema nervioso simpático como del sistema renina-angiotensina-aldosterona está estrechamente relacionada con la hipertensión arterial pulmonar. Nuestra hipótesis era que la simpatectomía renal reduce la actividad del sistema renina-angiotensina-aldosterona e inhibe la progresión de la hipertensión arterial pulmonar. Métodos. Se asignó aleatoriamente a un total de 22 perros beagle a tres grupos de estudio. Se efectuaron determinaciones de la dinámica pulmonar de esos animales antes y 8 semanas después de la inyección de 0,1 ml/kg de dimetilformamida (perros de control) o de 2 mg/kg de deshidromonocrotalina (perros con hipertensión arterial pulmonar y perros con hipertensión arterial pulmonar + simpatectomía renal). Ocho semanas después de la inyección, se determinaron las concentraciones de neurohormonas y se evaluó la morfología del tejido pulmonar. Resultados. Se observó un aumento significativo de la concentración de angiotensina II y endotelina-1 en plasma después de 8 semanas en los perros con hipertensión arterial pulmonar, y los valores obtenidos en los tejidos pulmonares de estos animales eran superiores a los de los perros del grupo de control y el grupo de simpatectomía renal (medias: angiotensina II, 65 ± 9,8 frente a 38 ± 6,7 y 46 ± 8,1; endotelina-1, 96 ± 10,3 frente a 54 ± 6,2 y 67 ± 9,4; p < 0,01). La deshidromonocrotalina aumentó la presión arterial pulmonar media (16 ± 3,4 frente a 33 ± 7,3 mmHg; p < 0,01), y la simpatectomía renal evitó que se produjera este aumento. La proliferación celular del músculo liso pulmonar fue mayor en los perros con hipertensión arterial pulmonar que en los animales de los grupos de control y de hipertensión arterial pulmonar + simpatectomía renal. Conclusiones. La simpatectomía renal atenúa el remodelado vascular pulmonar y reduce la presión arterial pulmonar en la hipertensión arterial pulmonar experimental. El efecto de la simpatectomía renal puede contribuir a reducir las concentraciones de neurohormonas (AU)

Introduction and objectives. Activation of both the sympathetic nervous system and the renin-angiotensin-aldosterone system is closely associated with pulmonary arterial hypertension. We hypothesized that renal denervation decreases renin-angiotensin-aldosterone activity and inhibits the progression of pulmonary arterial hypertension. Methods. Twenty-two beagles were randomized into 3 groups. The dogs’ pulmonary dynamics were measured before and 8 weeks after injection of 0.1 mL/kg dimethylformamide (control dogs) or 2 mg/kg dehydromonocrotaline (pulmonary arterial hypertension and pulmonary arterial hypertension + renal denervation dogs). Eight weeks after injection, neurohormone levels and pulmonary tissue morphology were measured. Results. Levels of plasma angiotensin II and endothelin-1 were significantly increased after 8 weeks in the pulmonary arterial hypertension dogs and were higher in the lung tissues of these dogs than in those of the control and renal denervation dogs (mean [standard deviation] angiotensin II: 65 [9.8] vs 38 [6.7], 46 [8.1]; endothelin-1: 96 [10.3] vs 54 [6.2], 67 [9.4]; P < .01). Dehydromonocrotaline increased the mean pulmonary arterial pressure (16 [3.4] mmHg vs 33 [7.3] mmHg; P < .01), and renal denervation prevented this increase. Pulmonary smooth muscle cell proliferation was higher in the pulmonary arterial hypertension dogs than in the control and pulmonary arterial hypertension + renal denervation dogs (AU)

Beneficial Effects of Renal Denervation on Pulmonary Vascular Remodeling in Experimental Pulmonary Artery Hypertension.

INTRODUCTION AND OBJECTIVES: Activation of both the sympathetic nervous system and the renin-angiotensin-aldosterone system is closely associated with pulmonary arterial hypertension. We hypothesized that renal denervation decreases renin-angiotensin-aldosterone activity and inhibits the progression of pulmonary arterial hypertension. METHODS: Twenty-two beagles were randomized into 3 groups. The dogs' pulmonary dynamics were measured before and 8 weeks after injection of 0.1mL/kg dimethylformamide (control dogs) or 2mg/kg dehydromonocrotaline (pulmonary arterial hypertension and pulmonary arterial hypertension + renal denervation dogs). Eight weeks after injection, neurohormone levels and pulmonary tissue morphology were measured. RESULTS: Levels of plasma angiotensin II and endothelin-1 were significantly increased after 8 weeks in the pulmonary arterial hypertension dogs and were higher in the lung tissues of these dogs than in those of the control and renal denervation dogs (mean [standard deviation] angiotensin II: 65 [9.8] vs 38 [6.7], 46 [8.1]; endothelin-1: 96 [10.3] vs 54 [6.2], 67 [9.4]; P < .01). Dehydromonocrotaline increased the mean pulmonary arterial pressure (16 [3.4] mmHg vs 33 [7.3] mmHg; P < .01), and renal denervation prevented this increase. Pulmonary smooth muscle cell proliferation was higher in the pulmonary arterial hypertension dogs than in the control and pulmonary arterial hypertension + renal denervation dogs. CONCLUSIONS: Renal denervation attenuates pulmonary vascular remodeling and decreases pulmonary arterial pressure in experimental pulmonary arterial hypertension. The effect of renal denervation may contribute to decreased neurohormone levels.

Changes in mRNA expression of p53 and related downstream genes in peripheral blood lymphocytes in workers occupationally exposed to arsenic / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the changes in mRNA expression of p53 and related downstream genes in peripheral blood lymphocytes in workers occupationally exposed to arsenic as well as its influencing factors, and to analyze the mechanism of genetic toxicity of arsenic.</p><p><b>METHODS</b>With cluster random sampling, 79 workers from an arsenic smelting plant were selected as exposure group, and another 24 people without occupational exposure to arsenic were selected as control group. The relative mRNA expression of p53 and related downstream genes in the peripheral blood lymphocytes of the two groups was determined by quantitative realtime PCR. The levels of inorganic arsenic (iAs), monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA) in urine were determined by hydride generation-atomic absorption spectrometry.</p><p><b>RESULTS</b>The exposure group had significantly higher levels of iAs, MMA, and DMA than the control group (P<0.01); the exposure group had significantly higher relative mRNA expression (2(-ΔΔCt)) of p53 and four related downstream genes in peripheral blood lymphocytes than the control group (P<0.05); the relative mRNA expression of p53 and related downstream genes was positively correlated with each other (P<0.01), with a correlation coefficient greater than 0.4; the levels of arsenic compounds in urine were positively correlated with the relative mRNA expression of p53 and some of its downstream genes (P<0.05).</p><p><b>CONCLUSION</b>The changes in mRNA expression of p53 and related downstream genes are closely related to the metabolic transformation of inorganic arsenic in workers occupationally exposed to arsenic, and it also plays an important role in genetic toxicity and carcinogenic effect in people exposed to arsenic.</p>

Estrogen increases apolipoprotein M through estrogen receptor / 中华内分泌代谢杂志

Objective To explore the effects of estrogen on apolipoprotein M ( apoM ).Methods ApoM mRNA was assayed in HepG2 cells by RT-PCR after incubation of estrogen with or without estrogen receptor antagonist at different concentrations and durations.SD female rats were divided into five groups:OVX group,Sham group,OVX+ EB group,normal group and normal + EB group.From a week of being operated,the rats were injected subcutaneously estradiol beuzoate or vehicle.After 12-hrs fasting,serum levels of triglycerides (TG),LDL-cholesterol,HDL-cholesterol,total cholesterol ( TC ) at months 1,2 and 3 after operation were measured.The expression of apoM in rats was detected by using real time RT-PCR and Western blot.Results Estrogen increased mRNA levels of apoM and apoAI in the HepG2 cells with a dose- and time-dependent manner,which could be abolished by addition of estrogen receptor antagonist.Serum apoM,TG,TC,HDL and LDL levels were significantly increased in the ovariectomized or normal rats which received estrogen treatment than those in OVX or normal group rats at month 1 after treatments.Conclusions Estrogen upregulates apoM expression via its receptor.

Study on the effects of acidosis on transient receptor potential channel M7 (TRPM7) in mouse cardiac fibroblast / 中华老年医学杂志

Objective To investigate the effects of acidosis on the current change of transient receptor potential channel M7 (TRPM7) and collagen production in mouse cardiac fibroblast (MCFs), and to explore the pathophysiological function of TRPM7 on the cardiac fibrosis. Methods (1) The model of MCFs was established and isolated. (2) MCFs was subcuhured. (3) Patch clamp technique was used to observe the current characteristics of TRPM7 in low PH solutions. (4) The influence of acidic condition on Ca2+ influx in MCFs was recorded by calcium fluorescent indicators. Results (1) There was a high level expression of TRPM7 in MCFs and the electrophysiological characteristics of TRPM7-like (TRPM7L) was similar to that of TRPM7. (2) Ca2+ influx was increased in acidic condition, and the F340/F380 ratio was increased from 1.0 to 4. 6 at pH 4.0 compared with pH 7.0 (t=2.72, P<0.01). Conclusions (1) TRPM7 is the molecular basis of the native TRPM7L in MCFs and TRPM7L plays an important role in Ca2+ influx. (2) The pathophysiological function of MCFs is influenced by regulation of Ca2+ influx mediated by TRPM7L in the condition of acidosis.

Changes and significance of transient receptor potential melastatin 7 after myocardial infarction in the mouse / 中华老年医学杂志

Objective To investigate the changes of TRPM 7-like current in mouse cardiac fibroblast(CFs) after myocardial infarction and the effect of myocardial ischemia on the TRPM 7 expression and current. Methods (1) The model of myocardial infarction was made and CFs were isolated;(2) CFs were cultured and infected by TRPM 7 siRNA;(3) The effects of myocardial ischemia on TRPM 7 current were recorded by whole cell patch clamp technique;(4) The influences of myocardial isehemia on Ca2+ influx in CFs were recorded by Ca2+ fluorescence imaging. (5) The effects of ischemia on total collagen content of CFs were studied. Results (1) Ca2+ inward current of CFs was increased after myocardial infarction [(16.2±1.7) vs. (7.4±0.7) pA/pF, P<0.053];(2) TRPM 7 current was reduced by 90% after siRNA infection;(3) The total collagen content of CFs after ischemia was approximately 2.3-fold higher than basic value. Conclusions Ca2+ influx in CFs plays an important role in the pathophysiological process of myocardial fibrosis.

Change in the collagen metabolic markers of ischemic cardiomyopathy and its clinical significance / 中国实用内科杂志

Objective To investigate the pathological contribution of serological markers of collagen metabolism including matrix-metalloproteinases(MMPs)and its tissue inhibitors(TIMPs),the markers for type I collagen degradation(ICTP)and synthesis(PICP)to cardiac remodeling of ischemic cardiomyopathy(ICM)as well as the pharmacological regulation effect.Methods Plasma levels of MMP-9,TIMP-1,ICTP and PICP were determined by ELISA and RIA in 86 consecutive ICM patients and 25 age-matched control subjects.Patients were divided into two subgroups according to ACEI-taking or not.Echocardiography were performed in all cases.Results The plasma concentration of MMP-9、TIMP-1 and MMP-9/TIMP-1 was significantly increased in ICM group(all P

Characteristics of transient photosynthesis in Quercus serrata seedlings grown under lightfleck and constant light regimes.

Photosynthetic-induction response and light-fleck utilization were investigated for the current-year seedlings of Quercus serrata, a deciduous tree found in temperate regions of Japan. The tree seedlings were grown under three light regimes: a constant low photosynthetic photon flux density (PFD) regime of 50 µmol m-2 s-1, a constant high PFD regime of 500 µmol m-2 s-1, and a lightfleck regime with alternated low (lasting 5 s) and high (lasting 35 s) PFD. The photosynthetic-induction response following a sudden increase of PFD from 50 to 500 µmol m-2 s-1 exhibited two phases: an initial fast increase complete within 3-5 s, and a second slow increase lasting for 15-20 min. Induction times required to reach 50% and 90% of steady-state assimilation rates were significantly shorter in leaves from the constant low PFD than those from the high PFD regime. During the first 60-100 s, the ratio of observed integrated CO2 uptake to that predicted by assuming that a steady-state assimilation would be achieved instantaneously after the light increase was significantly higher for leaves from the low PFD regime than from the high PFD regime. Lightfleck utilization was examined for various durations of PFD of 500 µmol m-2 s-1 on a background PFD of 50 µmol m-2 s-1. Lightfleck utilization efficiency was significantly higher in low PFD leaves than in the high PFD leaves for 5-s and 10-s lightflecks, but showed no difference among different light regimes for 100-s lightflecks. The contribution of post-illumination CO2 fixation to total carbon gain decreased markedly with increasing lightfleck durations, but exhibited no significant difference among growth regimes. Photosynthetic performances of induction response and lightfleck utilization in leaves from the lightfleck regime were more similar to those in leaves from the low PFD regime. It may be the total daily PFD rather than PFD dynamics in light regimes that affects the characteristics of transient photosynthesis in Q. serrata seedlings.