19F NMR investigation of molecular motion and packing in sonicated phospholipid vesicles

Dimyristoylphosphatidylcholine (DMPC) labeled with a C19F2 group in the 4-, 8-, or 12-position of the 2-acyl chain has been investigated in sonicated unilamellar vesicles (SUV) by fluorine-19 nuclear magnetic resonance (NMR) at 282.4 MHz from 26 to 42 degrees C. The 19F NMR spectra exhibit two overlapping resonances with different line widths. Spin-lattice relaxation time measurements have been performed in both the laboratory frame (T1) and the rotating frame (T1 rho) in order to investigate the packing and dynamics of phospholipids in lipid bilayers. Quantitative line-shape and relaxation analyses are possible by using the experimental chemical shift anisotropy (delta nu CSA) and the internuclear F-F vector order parameter (SFF) values obtained from the 19F powder spectra of multilamellar liposomes. The following conclusions can be made: The 19F chemical shift difference between the inside and outside leaflets of SUV can be used to monitor the lateral packing of the phospholipid in the two SUV monolayers. The hydrocarbon chains in the outer layer are found to be more tightly packed than those of the inner one, and the differences between them become smaller near the chain terminals. The effective correlation time [(1-4) x 10(-7) s] obtained from either the motional narrowing of the line widths or off-resonance T1 rho measurements is shorter than that estimated from the Stokes-Einstein diffusion model (10(-6) s), on the basis of a hydrodynamic radius of 110 A for SUV.(ABSTRACT TRUNCATED AT 250 WORDS)     

Endogenous CD8+ T cell expansion during regression of monoclonal EBV-associated posttransplant lymphoproliferative disorder.

There are experimental data which suggest that the primary immune effector cell responsible for maintaining immune surveillance against the outgrowth of EBV-transformed B cells in humans is the CTL, but in vivo proof of this is lacking. In this study we perform a series of cellular and molecular assays to characterize an autologous, endogenous immune response against a transplantation-associated, monoclonal, EBV+ posttransplant lymphoproliferative disorder (PTLD). Following allogeneic bone marrow transplantation, a patient developed a monoclonal PTLD of donor B cell origin. With a decrease in immune suppression, we document the emergence of endogenous, donor-derived CD3+CD8+ CTLs, followed by regression of the PTLD. The TCR Vbeta repertoire went from a polyclonal pattern prior to the development of PTLD to a restricted TCR Vbeta pattern during the outgrowth and regression of PTLD. Donor-derived CD3+CD8+ T lymphocytes displayed MHC class I-restricted cytolytic activity against the autologous EBV+ B cells ex vivo without additional in vitro sensitization. The striking temporal relationship between the endogenous expansion of a TCR Vbeta-restricted, CD3+CD8+ population of MHC class I-restricted CTL, and the regression of an autologous monoclonal PTLD, provides direct evidence in humans that endogenous CD3+CD8+ CTLs can be responsible for effective immune surveillance against malignant transformation of EBV+ B cells.     

Characterisation of Ilomastat for Prolonged Ocular Drug Release

We are developing tablet dosage forms for implantation directly into the subconjunctival space of the eye. The matrix metalloproteinase inhibitor, ilomastat, has previously been shown to be efficacious at suppressing scarring following glaucoma filtration surgery (GFS). We report on the physical characterisation of ilomastat which is being developed for ocular implantation. Since ilomastat is being considered for implantation it is necessary to examine its polymorphs and their influence on aspects of the in vitro drug release profile. X-ray powder diffraction identified two polymorphs of ilomastat from different commercial batches of the compound. Tablets were prepared from the two different polymorphs. Isothermal perfusion calorimetry was used to show that amorphous content is not increased during tablet formulation. The melting points of the two polymorphs are 188 and 208°C as determined by differential scanning calorimetry. Utilising single crystal X-ray diffraction, the structural conformations and packing arrangements of the different polymorphs were determined. The orthorhombic crystal crystallised as a monohydrate while the second monoclinic crystal form is non-solvated. Ilomastat tablets prepared from the two different solid forms exhibited similar drug release profiles in vitro under conditions mimicking the aqueous composition, volume and flow of the subconjunctival space after GFS. This suggests that a reproducible dose at each time point during release after implantation should be achievable in vivo with ilomastat tablets prepared from the two polymorphs identified.     

DHFR silence alleviated the development of liver fibrosis by affecting the crosstalk between hepatic stellate cells and macrophages

Liver fibrogenesis is a dynamic cellular and tissue process which has the potential to progress into cirrhosis of even liver cancer and liver failure. The activation of hepatic stellate cells (HSCs) is the central event underlying liver fibrosis. Besides, hepatic macrophages have been proposed as potential targets in combatting fibrosis. As for the relationship between HSCs and hepatic macrophages in liver fibrosis, it is generally considered that macrophages promoted liver fibrosis via activating HSCs. However, whether activated HSCs could in turn affect macrophage polarization has rarely been studied. In this study, mRNAs with significant differences were explored using exosomal RNA-sequencing of activated Lx-2 cells and normal RNA-sequencing of DHFR loss-of-function Lx-2 cell models. Cell functional experiments in both Lx-2 cells and macrophages animal model experiments were performed. The results basically confirmed exosomes secreted from activated HSCs could promote M1 polarization of macrophages further. Exosome harbouring DHFR played an important role in this process. DHFR silence in HSCs could decrease Lx-2 activation and M1 polarization of M0 macrophages and then alleviate the development of liver fibrosis both in vitro and vivo. Our work brought a new insight that exosomal DHFR derived from HSCs had a crucial role in crosstalk between HSCs activation and macrophage polarization, which may be a potential therapeutic target in liver fibrosis.     

具有阶段结构和免疫反应的病毒动力学模型的全局稳定性

研究了一类被感染细胞具有潜伏和活性两阶段以及免疫反应的病毒动力学模型.通过建立适当的Lyapunov泛函和使用LaSalle不变集原理,获得当σ≤1,ω≤1σ和σω1时,对应的未感染平衡点P,体液免疫未激活的无免疫感染平衡点M,体液免疫已激活的感染平衡点N是全局渐近稳定的充分条件.所获得结果推广了Nowak(1996)和Bangham(1997)的工作,得到了一些新结果.     

Serum miR-128-2 Serves as a Prognostic Marker for Patients with Hepatocellular Carcinoma

Circulating miRNAs are promising biomarkers for predicting the aggressiveness of hepatocellular carcinoma (HCC). We aimed to identify differentially expressed miRNAs in the serum of HCC patients with different Barcelona Clinic Liver Cancer (BCLC) stage, and to investigate the potential of serum miRNAs as biomarkers for patient outcomes. In the discovery stage, TaqMan Low-Density Array was used to test the difference in levels of serum miRNAs between 20 patients with portal vein tumor thrombosis (PVTT) and 20 patients without PVTT. The detected serum miRNAs then were validated in 182 patients. Fifteen serum miRNAs showed more than two-fold higher expression in patients with PVTT, and miR-128-2 was found to be significantly up-regulated and was selected for further validation. In the validation stage, patients were divided into two groups with low or high serum miR-128-2 using the median expression level of all 182 cases as the cut-off point. Kaplan-Meier analysis revealed that patients with low level of serum miR-128-2 had favorable trends of survival (log rank = 13.031, p < 0.001). The median survivals for patients with a low and high level of serum miR-128-2 were 625 (95% CI, 527–722) days and 426 (95% CI, 362–491) days, respectively. MiR-128-2 was also an independent factor of overall survival (p = 0.001, HR 2.793, 95%CI 1.550, 5.033). Serum levels of the ubiquitously expressed miR-128-2 showed no significant correlation with parameters of liver damage or liver function. In addition, expressions of miR-128-2 in HCC tissues were up-regulated in comparison with adjacent non-tumor tissues. In conclusion, serum level of miR-128-2 serves as a noninvasive biomarker for the overall survival of patients with hepatocellular carcinoma.     

Up-Regulatory Effects of Curcumin on Large Conductance Ca2+-Activated K+ Channels

Large conductance Ca²⁺-activated potassium channels (BK) are targets for research that explores therapeutic means to various diseases, owing to the roles of the channels in mediating multiple physiological processes in various cells and tissues. We investigated the pharmacological effects of curcumin, a compound isolated from the herb Curcuma longa, on BK channels. As recorded by whole-cell patch-clamp, curcumin increased BK (α) and BK (α+β1) currents in transfected HEK293 cells as well as the current density of BK in A7r5 smooth muscle cells in a dose-dependent manner. By incubating with curcumin for 24 hours, the current density of exogenous BK (α) in HEK293 cells and the endogenous BK in A7r5 cells were both enhanced notably, though the steady-state activation of the channels did not shift significantly, except for BK (α+β1). Curcumin up-regulated the BK protein expression without changing its mRNA level in A7r5 cells. The surface expression and the half-life of BK channels were also increased by curcumin in HEK293 cells. These effects of curcumin were abolished by MG-132, a proteasome inhibitor. Curcumin also increased ERK 1/2 phosphorylation, while inhibiting ERK by U0126 attenuated the curcumin-induced up-regulation of BK protein expression. We also observed that the curcumin-induced relaxation in the isolated rat aortic rings was significantly attenuated by paxilline, a BK channel specific blocker. These results show that curcumin enhances the activity of the BK channels by interacting with BK directly as well as enhancing BK protein expression through inhibiting proteasomal degradation and activating ERK signaling pathway. The findings suggest that curcumin is a potential BK channel activator and provide novel insight into its complicated pharmacological effects and the underlying mechanisms.     

Introduction of the Plant Front Cover:Cardamine scaposa Franch.

正Cardamine scaposa Franch.belongs to the family Brassicaceae.Herbs perennial,4~18cm tall,scapose,glabrous throughout.Rhizomes slender,with slender stolons.Stems leafless,erect,simple.Rhizomal leaves simple;petiole1~12cm;leaf blade reniform or suborbicular,0.3~2.0×0.5~3.0cm,base cordate,margin repand-crenate or entire.Cauline leaves absent.Racemes terminal,2~10-flowered.Fruiting pedicels