Comparison of neutralizing antibody and cell-mediated immune responses to pandemic H1N1 2009 influenza virus before and after H1N1 2009 influenza vaccination of elderly subjects and healthcare workers.

BACKGROUND: The recent H1N1 pandemic virus that emerged in 2009 resulted in high morbidity rates mainly in younger individuals, albeit with relatively low mortality. We investigated both humoral and cellular immune responses against the pandemic H1N1 2009 virus before and after immunization with inactivated H1N1 2009 vaccine. METHODS: We obtained paired blood specimens from a cohort of participants from nursing homes (n=108) and a public hospital (n=60) in Singapore. Serum samples were tested for neutralizing antibodies against H1N1 2009 using microneutralization assays, while peripheral blood mononuclear cells were subjected to interferon-γ enzyme-linked immunosorbent spot (ELISPOT) assays for whole virus-specific T-cell responses. RESULTS: We observed significant increases in geometric mean titers of neutralizing antibodies after H1N1 2009 vaccination (from 23.6 pre-vaccination to 94.7 post-vaccination). Approximately 77% and 54% of the cohort exhibited ≥2-fold and ≥4-fold increases in neutralizing antibody titers following vaccination; 89.9% of the cohort had a post-vaccination antibody titer of ≥32. Adjusted for gender, participants aged ≥60 years were less likely to have a ≥4-fold increase in antibody titers after vaccination than those aged <60 years (0.48; 95% confidence interval (95% CI) 0.32-0.71, p=0.007). There was a 1.4-fold elevation in H1N1 2009-specific T-cell responses after vaccination (p<0.05). Adjusted for gender, age ≥60 years was positively associated with a greater increase in T-cell response (ß=4.9, 95% CI 1.58-8.29, p=0.018). No significant correlation was observed between humoral and cellular immune responses. CONCLUSIONS: Influenza vaccination elicits significant neutralizing antibody and T-cell responses to pandemic H1N1 2009 influenza virus. However, in response to vaccination, increases in neutralizing antibody titers were comparatively lower but T-cell responses were higher in older participants. Therefore, our study suggests that memory T-cells may play a crucial role in protecting older individuals against pandemic H1N1 2009 infection.

Aspirin inhibits MMP-9 mRNA expression and release via the PPARalpha/gamma and COX-2/mPGES-1-mediated pathways in macrophages derived from THP-1 cells.

In present study, we investigated the effects of aspirin on matrix metalloproteinase (MMP)-9 mRNA expression and release and its possible mechanisms in macrophages derived from THP-1 cells. The macrophages were divided into different groups and treated with different drugs, the mRNA expression of MMP-9, peroxisome proliferator-activated receptor (PPAR) alpha and gamma, cyclooxygenase (COX)-2, membranebound prostaglandin E synthase (mPGES)-1 in macrophages were examined with reverse-transcription polymerase chain reaction, and the protein expressions of PPAR alpha and gamma, mPGES-1 were detected by Western-blot, the levels of MMP-9 and PGE(2) in cultured supernatants were determined with enzyme-linked immunosorbent assay. The results indicated that after the macrophages were incubated with aspirin for 24h, the MMP-9 mRNA expression and release were decreased, while the PPAR alpha/gamma mRNA and protein expression was increased, respectively, and PPAR alpha/gamma agonists could also decrease MMP-9 mRNA expression and release. Additionally, the COX-2 mRNA expression, mPGES-1 mRNA and protein expression in macrophages were all decreased after incubation with aspirin for 24h and the PGE(2) release was also decreased. The macrophages stimulated with PGE(2) for 24h might increase the MMP-9 mRNA expression and release. When PGE(2) plus PPAR alpha agonist or PPAR gamma agonist were simultaneously used, the stimulation of MMP-9 mRNA expression and release by PGE(2) was significantly decreased. It might be concluded that aspirin could inhibit the MMP-9 gene expression and release through the PPARalpha/gamma and COX-2/mPGES-1-mediated pathways and the two pathways might be partly overlapped and even be interrelated.

Inactivated trivalent seasonal influenza vaccine induces limited cross-reactive neutralizing antibody responses against 2009 pandemic and 1934 PR8 H1N1 strains.

BACKGROUND: In June 2009, we conducted a prospective study in Singapore on 51 individuals to determine their serologic responses before and following receipt of the 2009 Southern Hemisphere seasonal influenza vaccine. MATERIALS AND METHODS: Paired serum samples were obtained before and 3-4 weeks after vaccination. Virus microneutralization assays were performed to quantify antibodies against A/Brisbane/59/2007 vaccine, pandemic H1N1-2009 and A/Puerto Rico/08/34 H1N1 strains. RESULTS: Post-vaccination, 43%, 12% and 24% of subjects displayed a 4-fold or greater rise in neutralizing antibody titers against the three strains, respectively. There was a positive correlation among individuals who showed increased titers to both pandemic H1N1-2009 and A/Puerto Rico/08/34 (p<0.001). However, this correlation was not observed for A/Brisbane/59/2007 with either strain. The relative conservation and accessibility of predicted B-cell epitopes may explain the limited cross-reactivity of the antibodies directed against common H1N1 epitopes. CONCLUSIONS: These results suggest that seasonal influenza vaccination confers a certain degree of cross-protection to other H1N1 strains. The correlation in cross-reactive antibody titers to A/Puerto Rico/08/34 and pandemic H1N1-2009 implies that previous exposure to pre-1957 H1N1 strains may confer some protection against the 2009 pandemic strain.

Inhibitory effect of osthole on alcohol-induced fatty liver in mice.

BACKGROUND: Alcohol is a major cause of fatty liver, the disease is a spectrum that is initiated with steatosis, and without therapy it is apt to develop inflammation, necrosis, fibrosis and finally cirrhosis. There are currently no ideal pharmacological reagents that can prevent or reverse this disease. Osthole is an active constituent isolated from the fruit of Cnidium monnieri (L.) Cusson, a Chinese herbal medicine, which has been used in clinics for many years. It has many functions such as anti-inflammation, anti-osteoporosis and anti-tumor and so on, but there is no report about treatment of alcoholic fatty liver in mice. AIM: To examine the inhibitory effect of osthole on alcohol-induced fatty liver in mice and to investigate the potential mechanisms. METHODS: A mouse model with alcoholic fatty liver was induced by orally feeding 52% erguotou wine by gavage when they were simultaneously treated with osthole 10, 20, 40 mg/kg for 4 weeks. Whereafter, the lipids in serum and hepatic tissue, the levels of malondialdehyde (MDA), superoxide dismutase (SOD), reduced glutathione hormone (GSH), tumor necrosis factor-alpha (TNF-alpha) in hepatic tissue, hepatic weight coefficient and its histological evaluation were measured. RESULTS: After treatment with osthole, the levels of serum total cholesterol (TC), triglyceride (TG), coefficient of hepatic weight, and the hepatic tissue contents of TC and TG were significantly decreased, the levels of MDA and TNF-alpha in liver were also decreased, while the GSH in liver was increased. Importantly, the histological evaluation of liver specimens demonstrated that osthole dramatically decreased lipid accumulation. CONCLUSION: Osthole could inhibit alcohol-induced fatty liver in mice, and the mechanism might be associated with its anti-oxidation and suppression of TNF-alpha production.

Development of microsatellite markers in Dendrobium fimbriatum Hook, an endangered Chinese endemic herb.

As an endangered endemic herb, Dendrobium fimbriatum, is under threat from numerous impacts. In order to analyse the genetic diversity and structure of this endangered species, we provide details of 10 microsatellite loci (out of 15 primer pairs designed) which showed polymorphic for D. fimbriatum. These loci were used to screen 25 individuals from across the species' geographical range. Ten loci were polymorphic with 2 to 19 alleles; three loci were monomorphic, while the rest produced no amplification fragments. These loci will be used to investigate population genetic structure, genetic diversity, conservation, and individual authentication in the endangered D. fimbriatum.

Effect of quercetin on platelet aggregation induced by oxyradicals.

AIM: To study the action of quercetin (Que) on inhibiting platelet aggregation. METHODS: Active oxygen free radicals produced by xanthine/xanthine oxidase (Xan/XO) reaction was used, platelet aggregation was determined by the turbidimetric method, and the Xan/XO oxyradicals generating reaction by luminol-dependent chemiluminescence (Che) method. RESULTS: Active oxygen free radicals enhanced the platelet aggregation induced by ADP 1.6 mumol.L-1. The rate of maximal aggregation increased from 29%-38% for ADP to 59%-70% for ADP + Xan/XO. The enhancement was abolished by the treatment of platelet-rich plasma (PRP) with Que 650 mumol.L-1 or hydrocortisone (Hyd) 900 mg.L-1. Both Que and Hyd scavenged the active oxyradicals in vitro. The Che was decreased by 75.7% (Que 4 mumol.L-1) and 79.0% (Hyd 900 mg.L-1) as compared with control. CONCLUSION: Active oxygen free radicals participated in the platelet aggregation, and scavenging oxyradicals by Que was one of mechanisms of inhibiting platelet aggregation.

[Effect of quercetin on chemiluminescence of human platelets induced by arachidonic acid].

Arachidonic acid (AA)-induced platelet chemiluminescence (CL) was measured with a lumiphotometer. Quercetin remarkably inhibited the CL, the IC50 of quercetin was 3 mumol.L-1. When quercetin plus aspirin, which inhibits only cyclooxygenase, was added, the inhibitory rate of platelet-CL obviously increased (P < 0.01). On the other hand, the quercetin had a scavenging effect on superoxide anion radical using alkaline sodium dithionite solution generation. The IC50 was 20.9 mumol.L-1. In addition, superoxide dismutase of 0.1 mg.ml-1 inhibited the platelet-CL by 97.8%, while mannitol, a hydroxyl radical scavenger, only by 43.3% at a concentration of 80 mg.ml-1. These results suggest that the mechanism of the inhibiting AA-induced platelet-CL by quercetin was associated with scavenging the superoxide anion radical directly and with inhibiting the cyclooxygenase.

[Effects of piracetam on Na(+)-K(+)-ATPase and monoamine oxidase in rat brain and its antioxidation effect].

Piracetam, ig 600 mg.kg-1.d-1 for 30 d, caused a 20% decrease in the activity of Na(+)-K(+)-ATPase and monoamine oxidase (MAO) in vivo. In vitro, it presented an inhibitory effect on MAO, but had no direct effect on Na(+)-K(+)-ATPase at a concentration of 100 mmol.L-1. Piracetam had a potential action in scavenging free radicals. This action may be related to its clinical effects on amnesia and Alzheimer's disease.

Effect of lipanthyl on mRNA expression of endothelin-1 and nitric-oxide synthase in atherosclerotic vessel wall in rabbits.

AIM: To study the mechanism of regression of atherosclerosis (AS) by lipanthyl. METHODS: Experimental atherosclerotic rabbits created by damaging the abdominal aortic endothelium and feeding with high fat diet for 8 wk were then treated with lipanthyl 15 mg.kg-1.d-1 for 16 wk. Expression of endothelin (ET)-1 mRNA and nitric oxide synthase (NOS) mRNA in atherosclerotic vessel wall was measured by in situ hybridization and reverse transcription polymerase chain reaction (RT-PCR), respectively. RESULTS: After lipanthyl administration for 16 wk, ET-1 mRNA expression was reduced, and integral optical density (IOD) and area of hybridization granule were observed to be (49,113 +/- 16,868) and (2448 +/- 621) micron 2 in lipanthyl group and (65,188 +/- 10,113) and (3028 +/- 352) micron 2 in atherosclerotic group, respectively. Regarding inducible NOS mRNA expression, IOD and area were decreased by 25.5% and 53.3%, respectively, whereas endothelial NOS mRNA expression was increased. CONCLUSION: Restoration of the disturbed ET-1 mRNA/NOS mRNA balance by lipanthyl might be one of its mechanisms leading to regression of atherosclerosis.