[PROMOTION EFFECT OF CHONDROITIN SULFATE ON PROLIFERATION OF MYOBLASTS].

OBJECTIVE: To research the effect of chondroitin sulfate (CS) on the proliferation of myoblasts and the formation of myotube. METHODS: The myoblasts at passage 5 were used to prepare the cells suspension (1×108 cells/mL), and the experiment was divided into 4 groups based on CS concentration in the medium:group A (0 µg/mL), group B (50 µg/mL), group C (100 µg/mL), and group D (200 µg/mL). The cell morphology and myotube formation were observed by inverted microscope at 4, 5, and 8 days after treatment; MTT was used to detect the cell proliferation at 6 days, and the number of myotube was calculated by HE staining at 8 days. RESULTS: Cells showed spindle shape after adherent, with ovoid nuclei and dense cytoplasm under inverted microscope. When the cell adherent rate was 90%, cells arranged in whorls swirled and showed long fusiform adherent growth; and then nuclei fusion resulted in formation of multincleated myotubes. At 8 days, most myoblasts fused to form myotube in group A, but less myotube was observed in groups B and C, and the least myotube in group D. The absorbance (A) values of groups A, B, C, and D were 0.045 2±0.004 4, 0.540 4±0.096 7, 0.660 9±0.143 4, and 1.069 0±0.039 0 respectively, showing significant difference between other groups (P<0.05) except between groups B and C P>0.05). HE staining observation showed that most myoblasts fused to form myotube in group A, but less myotube in groups B and C, and the least myotube in group D. The number of myotube of groups A, B, C, and D were 222.01±30.02, 193.13±42.46, 170.26±11.96, and 136.88±16.78 respectively, showing no significant difference among groups (F=1.658, P=0.252). CONCLUSIONS: CS can significantly promote the proliferation of myoblast, the promotion is the biggest when CS concentration is 200 µg/mL.

Matrix-induced autologous chondrocyte implantation for the treatment of chondral defects of the knees in Chinese patients.

Articular cartilage injury is the most common type of damage seen in clinical orthopedic practice. The matrix-induced autologous chondrocyte implant (MACI) was developed to repair articular cartilage with an advance on the autologous chondrocyte implant procedure. This study aimed to evaluate whether MACI is a safe and efficacious cartilage repair treatment for patients with knee cartilage lesions. The primary outcomes were the Knee Injury and Osteoarthritis Outcome Score (KOOS) domains and magnetic resonance imaging (MRI) results, compared between baseline and postoperative months 3, 6, 12, and 24. A total of 15 patients (20 knees), with an average age of 33.9 years, had a mean defect size of 4.01 cm(2). By 6-month follow-up, KOOS results demonstrated significant improvements in symptoms and knee-related quality of life. MRI showed significant improvements in four individual graft scoring parameters at 24 months postoperatively. At 24 months, 90% of MACI grafts had filled completely and 10% had good-to-excellent filling of the chondral defect. Most (95%) of the MACI grafts were isointense and 5% were slightly hyperintense. Histologic evaluation at 15 and 24 months showed predominantly hyaline cartilage in newly generated tissue. There were no postoperative complications in any patients and no adverse events related to the MACI operation. This 2-year study has confirmed that MACI is safe and effective with the advantages of a simple technique and significant clinical improvements. Further functional and mechanistic studies with longer follow-up are needed to validate the efficacy and safety of MACI in patients with articular cartilage injuries.

Plumbagin induces apoptotic and autophagic cell death through inhibition of the PI3K/Akt/mTOR pathway in human non-small cell lung cancer cells.

Plumbagin (PLB) has shown anti-cancer activity but the mechanism is unclear. This study has found that PLB has a potent pro-apoptotic and pro-autophagic effect on A549 and H23 cells. PLB arrests cells in G2/M phase, and increases the intracellular level of reactive oxygen species in both cell lines. PLB dose-dependently induces autophagy through inhibition of PI3K/Akt/mTOR pathway as indicated by reduced phosphorylation of Akt and mTOR. Inhibition or induction of autophagy enhances PLB-induced apoptosis. There is crosstalk between PLB-induced apoptosis and autophagy. These findings indicate that PLB initiates both apoptosis and autophagy in NSCLC cells through coordinated pathways.

Quality of random number generators significantly affects results of Monte Carlo simulations for organic and biological systems.

We have simulated pure liquid butane, methanol, and hydrated alanine polypeptide with the Monte Carlo technique using three kinds of random number generators (RNG's)-the standard Linear Congruential Generator (LCG), a modification of the LCG with additional randomization used in the BOSS software, and the "Mersenne Twister" generator by Matsumoto and Nishimura. While using the latter two RNG's leads to reasonably similar physical features, the LCG produces significant different results. For the pure fluids, a noticeable expansion occurs. Using the original LCG on butane yields, a molecular volume of 171.4 Å(3) per molecule compared to about 163.6-163.9 Å(3) for the other two generators, a deviation of about 5%. For methanol, the LCG produces an average volume of 86.3 Å(3) per molecule, which is about 24% higher than the 68.8-70.2 Å(3) obtained with the RNG's in BOSS and the generator by Matsumoto and Nishimura. In case of the hydrated tridecaalanine peptide, the volume and energy tend to be noticeably greater with the LCG than with the BOSS (modified LCG) RNG's. For the simulated hydrated extended conformation of tridecaalanine, the difference in volume reached about 87%. The uniformity and periodicity of the generators do not seem to play the crucial role in these phenomena. We conclude that, it is important to test a RNG's by modeling a system such as the pure liquid methanol with a well-established force field before routinely employing it in Monte Carlo simulations.

[The experimental results of GVHD following orthotropic liver transplantation].

OBJECTIVE: To analyze experimental results of Graft-versus-host disease (GVHD) after liver transplantation. METHODS: 13 cases of GVHD out of the 1013 liver transplantation between 2002-2008 were analysed. Routine blood test, liver function and microorganisms test were done in all of the 13 cases, bone marrow test was done in 5 cases, liver pathological test was done in 5 cases, cytokines were analyzed in 4 cases, chimerism test was done in 6 cases. RESULTS: Leukocytes were reduced to various degree in all 13 cases, and were extremely low in 8 cases. Hematopoiesis was repressed in 4 cases. Normal liver function was found in 9 cases. Bacterium were found in blood, bile, wound secrete juice, excrement, phlegm of 10 cases. The pathological characteristics was in accordance with GVHD in 5 cases. The levels of IL-1 alpha, IL-1 beta, IL-2, IL-4 were low or undetectable. IL-10 was decreased in 4 cases but increased in 1 case. MCP-1, VEGF, IL-6, EGF, IL-8 were increasing or remained at high level during GVHD. TNF alpha was slightly increased. IFN gamma was only slightly changed before GVHD. CONCLUSION: Chimerism is a reliable but not unique evidence of GVHD.

Polarizable Simulations with Second order Interaction Model - force field and software for fast polarizable calculations: Parameters for small model systems and free energy calculations.

We are presenting POSSIM (POlarizable Simulations with Second order Interaction Model) - a software package and a set of parameters designed for molecular simulations. The key feature of POSSIM is that the electrostatic polarization is taken into account using a previously introduced fast formalism. This permits cutting computational cost of using the explicit polarization by about an order of magnitude. In this article, parameters for water, methane, ethane, propane, butane, methanol and NMA are introduced. These molecules are viewed as model systems for protein simulations. We have achieved our goal of ca. 0.5 kcal/mol accuracy for gas-phase dimerization energies and no more than 2% deviations in liquid state heats of vaporization and densities. Moreover, free energies of hydration of the polarizable methane, ethane and methanol have been calculated using the statistical perturbation theory. These calculations are a model for calculating protein pKa shifts and ligand binding affinities. The free energies of hydration were found to be 2.12 kcal/mol, 1.80 kcal/mol and -4.95 kcal/mol for methane, ethane and methanol, respectively. The experimentally determined literature values are 1.91 kcal/mol, 1.83 kcal/mol and -5.11 kcal/mol. The POSSIM average error in these absolute free energies of hydration is only about 0.13 kcal/mol. Using the statistical perturbation theory with polarizable force fields is not widespread, and we believe that this work opens road to further development of the POSSIM force field and its applications for obtaining accurate energies in protein-related computer modeling.

Empirical bond-order potential for hydrocarbons: adaptive treatment of van der Waals interactions.

Bond-order potentials provide a powerful class of models for simulating chemically reactive systems with classical potentials. In these models, the covalent bonding interactions adapt to the environment, allowing bond strength to change in response to local chemical changes. However, the non-bonded interactions should also adapt in response to chemical changes, an effect which is neglected in current bond-order potentials. Here the AIREBO potential is extended to include adaptive Lennard-Jones terms, allowing the van der Waals interactions to vary adaptively with the chemical environment. The resulting potential energy surface and its gradient remain continuous, allowing it to be used for dynamics simulations. This new potential is parameterized for hydrocarbons, and is fit to the energetics and densities of a variety of condensed phase molecular hydrocarbons. The resulting model is more accurate for modeling aromatic and other unsaturated hydrocarbon species, for which the original AIREBO potential had some deficiencies. Testing on compounds not used in the fitting procedure shows that the new model performs substantially better in predicting heats of vaporization and pressures (or densities) of condensed-phase molecular hydrocarbons.