The Optimal Concentration of Formaldehyde is Key to Stabilizing the Pre-Fusion Conformation of Respiratory Syncytial Virus Fusion Protein.

BACKGROUND: To date, there is no licensed vaccine available to prevent respiratory syncytial virus (RSV) infection. The valuable pre-fusion conformation of the fusion protein (pre-F) is prone to lose high neutralizing antigenic sites. The goals of this study were to stabilize pre-F protein by fixatives and try to find the possibility of developing an inactivated RSV vaccine. METHODS: The screen of the optimal fixative condition was performed with flow cytometry. BALB/c mice were immunized intramuscularly with different immunogens. The serum neutralizing antibody titers of immunized mice were determined by neutralization assay. The protection and safety of these immunogens were assessed. RESULTS: Fixation in an optimal concentration of formaldehyde (0.0244%-0.0977%) or paraformaldehyde (0.0625%-1%) was able to stabilize pre-F. Additionally, BALB/c mice inoculated with optimally stabilized pre-F protein (opti-fixed) induced a higher anti-RSV neutralization (9.7 log2, mean value of dilution rate) than those inoculated with unstable (unfixed, 8.91 log2, p < 0.01) or excessively fixed (exce-fixed, 7.28 log2, p < 0.01) pre-F protein. Furthermore, the opti-fixed immunogen did not induce enhanced RSV disease. CONCLUSIONS: Only the proper concentration of fixatives could stabilize pre-F and the optimal formaldehyde condition provides a potential reference for development of an inactivated RSV vaccine.

Oral sildenafil therapy for Chinese patients with pulmonary arterial hypertension: a multicenter study.

The impact of sildenafil on pulmonary arterial hypertension (PAH) in Chinese patients has been less investigated. A prospective, open-label, uncontrolled and multicenter study, therefore, was carried out to address this issue. Ninety patients with multicause-induced PAH received oral sildenafil (75 mg/day) for 12 weeks. The 6-minute walk test (SMWT) and cardiac catheterization were performed at the beginning and the end of the 12 weeks. The primary endpoint was the changes in exercise capacity assessed by the SMWT; the secondary endpoint included assessment of functional class, evaluation of cardiopulmonary hemodynamics, and clinical worsening. Drug safety and tolerability were also examined. The results showed that there was a significant improvement in SMWT distances (342 ± 93 m vs 403 ± 88 m, P < .0001), Borg dyspnea score (2.9 ± 2.6 vs 2.4 ± 2.0, P = .0046), World Health Organization functional class, and cardiopulmonary hemodynamics (mean pulmonary artery pressure, P < .0001; cardiac index, P < .0001; pulmonary vascular resistance, P < .0001) after 12 weeks of oral sidenafil therapy. Almost all enrolled patients did not experience significant clinical worsening. This study confirms and extends the findings of previous studies relating to effects of sildenafil on PAH, suggesting that oral sildenafil is safe and effective for the treatment of adult patients with PAH in the Chinese population.

Neuropective constituents from the rhizomes of Abacopteris penangiana.

Two neuropective compounds were isolated from the rhizomes of Abacopteris penangiana, one was a new flavone and the other was a flavanone. Both compounds were firstly separated from natural plant. The isolation work was guided by the antioxidant activity. Both the compounds showed a significant antioxidant activity in vitro and a protective effect on dopamine-induced neurotoxicity in PC12 cells.

[Preliminary study on the efficacy and safety of oral sildenafil in pulmonary arterial hypertension in China].

OBJECTIVE: Sildenafil has been shown to be effective in pulmonary arterial hypertension (PAH). However, the impact of sildenafil on PAH has been under-investigated in China. The aim of the present study was to evaluate the efficacy and safety of oral sildenafil in PAH patients in China. METHODS: In this prospective, open-label and multi-center study, 90 patients were recruited from 14 centers to receive oral sildenafil (75 mg/d) for 12 weeks. They underwent a six-minute walk test (SMWT) and cardiac catheterization at the beginning and the end of 12 weeks. The primary endpoint was the changes in exercise capacity as assessed by SMWT. And the secondary endpoints included assessment of functional class, evaluation of cardiopulmonary hemodynamics and clinical deterioration (defined as death, transplantation and re-hospitalization for PAH). Drug safety and tolerability were also examined. RESULTS: There were 19 males and 71 females with an average age of 32.5 ± 12.1 years old (range: 18 - 61). Their etiologies were idiopathic (n = 15), related with congenital heart disease (n = 60), or related with connective tissue disease (n = 9) and chronic thromboembolic pulmonary hypertension (n = 6). Oral sildenafil significantly increased the SMWT distances [(342 ± 93) m vs. (403 ± 88) m, P < 0.001]. There was also remarkable improvement in Borg dyspnea score (2.9 ± 2.6 vs. 2.4 ± 2.0, P = 0.005). Furthermore, significant improvements in World Healthy Organization (WHO) functional class and cardiopulmonary hemodynamics were also found (mean pulmonary artery pressure, P < 0.001; cardiac index, P < 0.001; pulmonary vascular resistance, P < 0.001). Side effects were mild and consistent with other reports. CONCLUSION: This study confirms and extends previous studies. Oral sildenafil is both safe and effective for the treatment of adult PAH patients in China.

Parathelypteriside attenuates cognition deficits in d-galactose treated mice by increasing antioxidant capacity and improving long-term potentiation.

Parathelypteriside (PG), a stilbenoid compound, was extracted from Parathelypteris glanduligera (kze.) ching that exhibits antioxidative and anti-inflammatory effects. The aim of this study was to investigate the protective effect of PG against the d-galactose (d-gal)-induced neurotoxicity in mice. It was found that long-term intraperitoneal (i.p.) injection of PG (5 or 10 mg/(kg day)) for two weeks significantly improved the behavioral performance of d-gal-treated mice in both Morris water maze test and step-down avoidance test. Biochemical examination revealed that PG reduced the increased levels of malondialdehyde (MDA), and attenuated the decreased activities of superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase in the hippocampus of d-gal-treated mice. Furthermore, the electrophysiological assay showed that PG significantly rescued the long-term potentiation (LTP) impairment in mice hippocampus, and western blotting analysis indicated that the effects of PG on LTP might be attributed to the activation of cAMP-response element-binding protein (CREB). Together, these results suggested that the natural product PG represented a potential source of medicine for the treatment of the neurodegenerative diseases.

Impact of sildenafil therapy on pulmonary arterial hypertension in adults with congenital heart disease.

BACKGROUND: It has been demonstrated that sildenafil is effective in patients with pulmonary arterial hypertension (PAH). However, the impact of sildenafil on PAH in adults with congenital heart disease (CHD) has been less investigated. OBJECTIVE: In this prospective, open-label, uncontrolled and multicenter study, 60 patients with PAH related to CHD received oral sildenafil (75 mg/day) for 12 weeks. The enrolled patients underwent six-minute walk test (SMWT) and cardiac catheterization at the beginning and the end of the 12 weeks. The primary end point was the changes in exercise capacity assessed by SMWT; the secondary end point included assessment of functional class, evaluation of cardiopulmonary hemodynamics, and clinical worsening (defined as death, transplantation, and rehospitalization for PAH). Drug safety and tolerability were also examined. RESULTS: Oral sidenafil significantly increased SMWT distances (422.94 ± 76.95 m vs. 371.99 ± 78.73 m, P < 0.0001). There was also remarkable improvement in Borg dyspnea score (2.1 ± 1.32 vs. 2.57 ± 1.42, P = 0.0307). Moreover, significant improvements in World Healthy Organization (WHO) functional class and cardiopulmonary hemodynamics were also discovered (mean pulmonary artery pressure, P = 0.0002; cardiac index, P < 0.0001; pulmonary vascular resistance, P < 0.0001). Side effects in this study were mild and consistent with reported studies. None of the enrolled patients experienced significant clinical worsening. CONCLUSIONS: This study confirmed and extended previous studies. It suggested that oral sildenafil was safe and effective for the treatment of adult patients with CHD-related PAH.

[Effect of temperature and denitrifying phosphorus on nitrogen and phosphorous removal in SBMBBR].

The effect of two kinds of temperature conditions (14 degrees C +/- 1 degrees C and 24 degrees C +/- 1 degrees C) on the removal of phosphorus and nitrogen were studied in a sequencing batch moving bed biofilm reactor (SBMBBR). The experiments were performed at the concentrations of COD, nitrogen and phosphorus in the feed fixing at about 450 mg/L, 40 mg/L and 10 mg/L, respectively. The results indicated that under the two temperatures the phosphorus release amounts were 54.7 mg/L, 19.7 mg/L, and the phosphorus removals were 98.3%, 83.4%, and the total nitrogen removals were 87.8%, 98.4%, respectively. It found that PAOs (phosphorus-accumulating organisms) predominated in the biomass and the nitrifying level was low at the lower temperature. However, with increase of temperature, PAOs were no longer the predominant microbial species and the total nitrogen removal efficiency increased. A denitrifying phosphorus experiment was carried out under the mode of anaerobic/anoxic in the SBMBBR after 3 months anaerobic/oxic operation. The results showed the ratio of denitrifying phosphorus removal to total phosphorus removal was about 80%.

[Detection of hantaan virus from gamasid mite and chigger mite by molecular biological methods].

OBJECTIVE: To study the proliferation and location of hantaan virus (HV) in gamasid mites and chigger mites. METHODS: HV RNA in gamasid mites and chigger mites were detected by reverse transcription, polymerase chain reaction (RT- PCR) and in situ hybridization. RESULTS: The smallest quantity of mite from which HV RNA could be detected was 5 mites group. The titers of -and proliferated in mites HV RNA could be found in ovary cells and dug cells of gamasid mites and chigger mites by in situ hybridization. CONCLUSIONS: The results showed that HV could be trans-stadially transmitted and proliferated in mites, and HV always located in ovary and dug organs of mites. These results provide direct evidence at molecular level for the role of gamasid mites and chigger mites as vectors in transmission of HV.