The role of atria in ventricular fibrillation after continuous-flow left ventricular assist device implantation in ovine model.

Objectives: This study attempted to explore the hemodynamics and potential mechanisms driving pulmonary circulation in status of ventricular fibrillation (VF) following continuous-flow left ventricular assist device (CF-LVAD) implantation. Methods: An ovine CF-LVAD model was built in small-tailed Han sheep, with the pump speed set as 2,400 rpm. VF was induced following ventricular tachycardia using a temporary pacemaker probe to stimulate the right and left ventricular free walls. The central venous pressure (CVP), pump flow (PF), pulmonary artery flow (PAF) and other major indicators were observed and recorded after VF. Results: Low-flow systemic and pulmonary circulation could be sustained for 60 min under VF with sinus atrial rhythm after CF-LVAD implantation. The CVP gradually increased. The mean PF declined from 1.80 to 1.20 L/min, and the mean PAF decreased from 1.62 L/min to 0.87 L/min. Under VF with atrial fibrillation, the systemic and pulmonary circulation couldn't be sustained. The CVP jumped from the 5 mmHg baseline to 12 mmHg, the mean PF rapidly decreased from 3.45 L/min to 0.79 L/min, and the PAF declined from 3.94 L/min to 0.77 L/min. Conclusion: The atrial rhythm and function might be essential for the circulation maintenance in patients with VF after CF-LVAD implantation.

[Dynamic accumulation of three main triterpenic acids in submerged cultivation mycelium of Poria cocos].

OBJECTIVE: To study the dymamic accumulation of triterpenic acids production in submerged cultivation mycelium of Poria cocos. METHOD: Liquid culture method of P. cocos was established and RP-HPLC was applied to determine the contents of three main triterpenic acids dehydrotumulosic acid (DTA), 3-epi-dehydrotumulosic acid (eDTA) and polyporenic acid C (PAC) in submerged cultivation mycelium P. cocos at different culture stages and the contents were compared with cultivated P. cocos. The HPLC method is as follows, column: Plastisil ODS (4.6 mm x 250 mm, 5 microm); mobile phase: ACN/0.5% phosphate (80:20); flow rate: 1.0 mL . min-1; detective wavelength: 242 nm. RESULT: The maximum biomass occurred at the 8th d after inoluctation, however, the contents and yield of three compounds increased till the 17th day. The contents of three compounds were 1. 2% (DTA), 0. 42% (eDTA) and 1.0% (PAC) at the 17th day after inoculation, which were significantly higher than that in cultivated material [0.2% (DTA), 0. 12(eDTA) and 0. 16% (PAC) ]. Furthermore, a correlation analysis between the content ratios of three independent compounds was carried out. The results showed that DTA negatively correlated with eDTA and PAC, with R2 of 0. 857 6 and 0. 971 7, respectively, which suggested the role of DTA as an important intermediate in the biosynthesis of triterpenic acids in P. cocos. CONCLUSION: The sum content of three main terpenoids in submerged cultivation mycelium P. cocos was 5. 55 times as that in cultivated material, which strongly suggested the possibility of fermentation in the production of medicinally important triterpenic acids in the future.

Effects of lovastatin, clomazone and methyl jasmonate treatment on the accumulation of purpurin and mollugin in cell suspension cultures of Rubia cordifolia.

AIM: To determine the IPP origin of the naphthoquinones (NQs) in Rubia cordifolia, and to evaluate the effects of methyl jasmonate (MeJA) treatment, MEP, and MVA pathway inhibitor treatment on the accumulation of anthraquinones (AQs) and NQs in cell suspension cultures of R. cordifolia. METHODS: Cell suspension cultures of R. cordifolia were established. Specific inhibitors (lovastatin and clomazone) and MeJA were supplied to the media, respectively. Treated cells were sampled every three days. Content determination of purpurin (AQs) and mollugin (NQs) were carried out using RP-HPLC. The yield of the two compounds was compared with the DMSO-supplied group and the possible mechanism was discussed. RESULTS: Lovastatin treatment increased the yield of purpurin and mollugin significantly. Clomazone treatment resulted in a remarkable decrease of both compounds. In the MeJA-treated cells, the purpurin yield increased, meanwhile, the mollugin yield decreased compared with control. CONCLUSION: The IPP origin of mollugin in R. cordifolia cell suspension cultures was likely from the MEP pathway. To explain the different effects of MeJA on AQs and NQs accumulation, studies on the regulation and expression of the genes, especially after prenylation of 1,4-dihydroxy-2-naphthoic acid should be conducted.

[Quality evaluation and antioxidant activity research of Schisandra chinensis from various habitats].

OBJECTIVE: To determine the contents of lignans, crude polysaccharides (CP) and total phenolic compounds (TPC) of Schisandra chinensis from various habitats in Liaoning province and evaluate their quality and free radical scavenging (FRS) activity. METHODS: Contents of schisandrol, deoxyschizandrin and schisandrin B were determined by RP-HPLC. Contents of TPC, CP and FRS activity were determined by Folin-Cicalteu's, phenol-sulfuric acid and DPPH x method, respectively. RESULTS: Sample from Liaoyang city had the highest contents of lignans (21.75 mg/g); Sample from Shenbei New district of Shenyang city had the highest contents of CP (88.72 mg/g); Sample from Guanmenshan district of Benxi city had the highest contents of TPC and FRS activity (26.06 mg/g and 86.3%, respectively). Linear regression analysis results showed that contents of TPC had higher correlation coefficient with FRS activity than that of lignans. Their linear regression equations were Y = 1.3677X + 46.97, R2 = 0.6869 and Y = 2.5916X + 57.927, R2 = 0.1747 for TPC and lignans with FRS activity, respectively. CONCLUSION: The contents of lignans, CP and TPC are significantly different from samples collected from various habitats in Liaoning province. The main antioxidative substances are TPC, and lignans have no significant correlation with FRS activity.

[Cloning and expression of a homologue of human macrophage migration inhibitory factor from P. falciparum 3D7].

OBJECTIVE: To clone and express a homologue of human macrophage migration inhibitory factor (MIF) from P. falciparum 3D7--PfMIF. METHODS: The nucleotide sequence of PfMIF was found through blast P. falciparum genomic sequence databases with the amino acid sequence of human MIF (HuMIF). RT-PCR, DNA sequencing, and bioinformatics analysis were used for the cloning of Pfmif gene. The recombinant protein was expressed in E. coli and purified through the affinity column. RESULTS: The full length of Pfmif gene was cloned and sequenced. It was composed of 351 nucleotides and encoded 116 amino acids with the typical characteristic of MIF family. The recombinant protein was successfully expressed and purified. CONCLUSIONS: The Pfmif gene and recombinant protein were successfully isolated and PfMIF was preliminarily identified as a novel member of MIF family.