A novel sustained-release formulation of recombinant human growth hormone and its pharmacokinetic, pharmacodynamic and safety profiles.

An effective and safe formulation of sustained-release rhGH for two months using poly(monomethoxypolyethylene glycol-co-D,L-lactide) (mPEG-PLA, PELA) microspheres was developed to reduce the frequency of medication. The rhGH-loaded PELA microspheres with a narrow size distribution were successfully prepared by a double emulsion method combined with a premix membrane emulsification technique without any exogenous stabilizing excipients. The narrow size distribution of the microspheres would guarantee repeatable productivity and release behavior. Moreover, the amphiphilic PELA improved the bioactivity retention of protein drugs since it prevented protein contact with the oil/water interface and the hydrophobic network, and modulated diffusion of acidic degradation products from the carrier system. These PELA microspheres were compared in vivo with commercial rhGH solution, conventional poly(D,L-lactic acid) (PLA) and poly(D,L-lactic-co-glycolic acid) (PLGA) microspheres. Administration of rhGH-PELA could extend the duration of rhGH release (for up to 56 days) and increase area under the curve (AUC) compared to rhGH solution, PLA or PLGA microspheres in Sprague-Dawley (SD) rats. In addition, rhGH-PELA microspheres induced a greater response in total insulin-like growth factor-1 (IGF-1) and insulin-like growth factor binding protein-3 (IGFBP-3) than other rhGH formulations. With a hypophysectomized SD rat model, the pharmacological efficacy of rhGH-PELA microspheres was shown to be better than that from daily administration of rhGH solutions over 6 days based on body weight gain and width of the tibial growth plate. Histological examination of the injection sites indicated a significantly milder inflammatory response than that observed after injection of PLA and PLGA microspheres. Neither anti-rhGH antibodies nor the toxic effects on heart, liver and kidney were detectable after administration of rhGH-PELA microspheres in SD rats. These results suggest that rhGH-PELA microspheres have the potential to be clinically effective and safe when administered only once every two months, a dose regimen for better patient acceptance and compliance.

PEG as a spacer arm markedly increases the immunogenicity of meningococcal group Y polysaccharide conjugate vaccine.

Neisseria meningitidis is a life-threatening pathogen that causes meningitis and other clinical manifestations. As a key virulence determinant, meningococcal capsular polysaccharide (PS) can be used to prevent meningococcal diseases. Conjugation of PS to carrier protein can significantly improve the immunogenicity of PS and induce memory response in infants and young children. However, the conjugate vaccine may suffer from steric shielding of antigenic PS epitopes by carrier protein. Here, a heterobifunctional polyethylene glycol (PEG) was used as a spacer arm to conjugate meningococcal group Y capsular PS with tetanus toxoid (TT). PEG can avoid self-crosslink of PS and increase the PS/TT ratio of the vaccine. Significant structural change in TT and PS was not observed upon conjugation. As compared to the vaccine without PEG, immunization with the vaccine using PEG as the spacer arm led to a 3.0-fold increase in the PS-specific IgG titers and a prolonged immune persistence. Paradoxically, PEG, a non-immunogenic hydrophilic polymer has been widely used to couple therapeutic protein for increasing its circulatory time and decreasing its immunogenicity. Presumably, PEG can fully decrease the steric shielding effect of TT on antigenic epitopes of PS and suppress the immunogenicity of TT. In addition, PEG can prolong the immune persistence of the conjugate vaccine and improve its ability to elicit cellular immunity. Thus, PEG can be used as a spacer arm to develop more effective PS conjugate vaccine for prevention of bacterial infection.

The effects of long term aerobic exercise on the hemorheology in rats fed with high-fat diet.

Hypercholesterolemia is one of the cardiovascular risk factors sensitive to preventive and control interventions. Here we created a hypercholesterolemia model to investigate the effect of the long term aerobic exercise (swimming) on the hemorheology of rats fed with high-fat diet. We found that the rats fed with high-fat diet developed hypercholesterolmia and hepatic steatosis and their hemorheological and coagulative properties were all impaired as compared to those of the rats fed with standard diet. But after exercise, the total cholesterol and triglyceride in the plasma were significantly decreased and the severity of hepatic steatosis were reduced. Exercise greatly improved the erythrocytes' hemorheological properties, including deformability, electrophoretic mobility and osmotic fragility. Exercise also markedly lowered the activated partial thromboplastin time (APTT) but had moderate effects on other coagulative parameters. The high oxidative stress level, as indicated by plasma MDA concentration, in rats with high-fat diet was significantly attenuated to the normal level after exercise. The present study suggests that long term aerobic exercise could remarkably improve the abnormal hemorheological property and the oxidative stress in rats with hypercholesterolemia.

Serum IgA against type 3 muscarinic acetylcholine receptor is a novel marker in diagnosis of Sjögren's syndrome.

BACKGROUND: Antibodies against type 3 muscarinic acetylcholine receptor (M3R) are involved in the pathogenesis of Sjögren's syndrome (SS), but the clinical value of them in SS patients has been controversial. The aims of this study were to: (1) establish an improved enzyme-linked immunosorbent assay (ELISA) to detect IgA antibodies against M3R; (2) evaluate the value of IgA antibodies against the second extracellular loop of M3R205-220 (c2M3RP) in diagnosis of SS. METHODS: To increase the ELISA sensitivity, c2M3RP was coupled to bovine serum albumin (BSA) by the glutaraldehyde method and a 96-well microplate was treated by ultraviolet rays before coated. Concentrations of anti-c2M3RP, anti-SSA, and anti-SSB were measured in the sera of 240 individuals: 91 patients with primary SS and 149 controls (16 secondary SS, 27 systemic lupus erythematosus, 40 rheumatoid arthritis and 66 healthy controls). Diagnostic properties of anti-c2M3RP were determined by receiver-operating characteristic curve analysis. RESULTS: The prevalence of serum IgA anti-c2M3RP antibodies in patients with pSS (46%, 42/91) was significantly higher than that in patients with systemic lupus erythematosus (19%, 5/27), in rheumatoid arthritis (15%, 6/40) and in healthy controls (5%, 3/66). However, there was no significant difference between the two SS groups (P = 0.727). The diagnostic performance of IgA anti-M3RP antibodies was similar to anti-SSA assay, but had 22% higher sensitivity than anti-SSB. By analyzing of IgA anti-c2M3RP antibodies, combination of anti-SSA and anti-SSB resulted in increased sensitivity, whereas their specificity was not significantly changed. CONCLUSIONS: The improved anti-c2M3RP ELISA is a novel, sensitive, and specific serological test for the diagnosis of SS. The combined application of anti-c2M3RP, anti-SSA and anti-SSB tests can improve the laboratory diagnosis of SS. The IgA anti-c2M3RP antibodies may serve as a novel diagnostic marker for SS.

Nordihydroguaiaretic acid restores expression of silenced E-cadherin gene in human breast cancer cell lines and xenografts.

In our study we use nordihydroguaiaretic acid (NDGA), the naturally occurring lignan, to investigate whether it plays a role in the prevention and treatment of cancer by epigenetic modifications. The growth inhibitory effect of NDGA on human breast cancer cell lines was determined using the MTT assay (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay). It substantially inhibited the growth of human breast cancer cell lines SKBR3 and MDA-MB-435 with an estimated IC50 of 31.09+/-1.6 and 38.8+/-2.1 micromol/l respectively, after 4 days incubation with different NDGA concentrations. The in-vivo anticancer activity of NDGA was evaluated by calculating the tumor growth inhibition value. NDGA substantially inhibited the growth of human breast carcinoma cells in both animal and cell-based models. We also found that a single treatment with NDGA reactivates methylation-silenced E-cadherin gene in vitro and in vivo, suggesting an intriguing concept that lignans may act as natural effective epigenetic modifiers in the prevention and treatment of cancer.

[Effects of oxymatrine on serum levels of Th1/Th2 type cytokines in HBsAg transgenic mice].

OBJECTIVE: To explore the effects of oxymatrine on serum levels of Th1/Th2 cytokines in HBsAg transgenic mice. METHODS: HBsAg transgenic mice were divided into oxymatrine group and control group. Each mouse was injected with either oxymatrine 200 mg/kg 0.2 ml or 0.9% NaCl 0.2 ml intraperitoneally once a day for 30 days. Serum IFN-gamma, IL-2 and IL-4, IL-10 were quantitated before and after different treatment. RESULTS: There was no significant difference on the levels of IFN-gamma and IL-4 before and after treatment in control group. While in oxymatrine group, the levels of IFN-gamma before and after treatment were (3.108+/-3.172) pg/ml and (11.059+/-6.971) pg/ml; those of IL-4 were (29.045+/-13.235) pg/ml and (13.024+/-9.002) pg/ml (both P less than 0.001). After treatment, the levels of IL-2 in control and oxymatrine group were (1.070+/-0.447) pg/ml and (5.537+/-2.887) pg/ml (P less than 0.000 1); and those of IL-10 were (97.226+/-73.306) pg/ml and (33.607+/-23.154) pg/ml (P less than 0.01). CONCLUSION: After injection of oxymatrine to HBsAg transgenic mice, the serum concentration of Th1 cytokines increased while the Th2 cytokines decreased. This can help us understand more better on the mechanisms of anti-HBV effect of oxymatrine.