OBJECTIVE: To figure out the balance mechanism between brand-name drugs and generic drugs in American drug review. METHODS: This paper reviewed FDA laws and regulations, domestic and foreign literature to retrospect the basis of generic development and explore the brand-name drug companies' action to prevent generic competition. RESULTS AND CONCLUSION: The abbreviate new drug application, patent challenge and market exclusivity in the Hatch-Waxman Act were the basis of generic development. Brand-name drug companies prevented competition by occupying the market, refusing to provide samples, submitting citizen petitions to extend generic drug review time and extending the patent term and market exclusivity of brand-name drugs. The United States legislated and amended relevant laws and regulations, adjusted the generic drug user fee to maintain the stability of the balance, which is worthy of further research.

Adult ; Female ; Humans ; Lupus Erythematosus, Systemic ; enzymology ; Male ; Middle Aged ; Peroxidase ; blood

Animals ; Humans ; Parasites ; Parasitic Diseases ; pathology ; Staining and Labeling ; methods

Accidents, Occupational ; statistics & numerical data ; Adult ; Extraction and Processing Industry ; Female ; Humans ; Male ; Petroleum

Cadherins ; genetics ; Hearing Loss, Sensorineural ; genetics ; pathology ; Humans

The potential of a Sinorhizobium fredii strain producing a copolymer polyhydroxyalkanoate(PHA)from glucose and sodium decanoate substrates was studied in this paper.Using orthogonal design in a flask-shaker culture system,the culture medium,some culture conditions and vital regulation conditions for polymer synthesis were optimized.These optimized results were applied into further studies in two-stage fed-batch with a 10L fermentor.The whole culture process consisted of two stages,that is,the cell growth and the copolymer production.The first stage was for the cell growing to a desired biomass and the second was for the copolymer synthesis.For producing PHA polymers,the selected 8 mM sodium decanoate was added into the broth by adopting a two-step adding method for avoiding of foaming when the biomass had approached 28.5g/L dry cell.The maximum P(HB-HH)production could be 17.55 g/L with a monomer ratio of 79.4%(W/W)3-HB and 20.6%(W/W)3-HH.The molecule constitute of the copolymer is poly(3-hydroxybutyrate-co-3-hydroxyhexanoate)[P(HB-HH)] and its molecular weight(MW)is 1.4?105D.The results demonstrated that the employed S.fredii strain could be a potential candidate for industrial production of the copolymer.The fermentation parameters acquired in the experimental system offered some valuable references for studying large-scale production of the copolymer.

Objective:To investigate the effect of miR-34a targeting PAX6 on JAK/STAT signaling pathway on invasion and metastasis of retinoblastoma.Methods:The expression of PAX6 in retinoblastoma tissues was detected by immunohistochemistry.The expression of miR-34a in retinoblastoma cell line was detected by PCR.The effect of miR-34a on the expression of PAX6 was examined by the dual luciferase gene system.Transwell invasion assay and scratch test was used to detect the ability of invasion and migration in the retinoblastoma cell line Rb44 after overexpression miR-34a.Western blot was used to detect the protein expression of JAK/STAT signal pathway after overexpression miR-34a.Results:The expression of PAX6 was significantly higher in retinoblastoma tissues than that in normal tissues.The miR-34a was lower in retinoblastoma tissues than that in normal tissues.Western blot analysis showed the lowest level of PAX6 in Rb44 retinoblastoma.The dual luciferase reporter gene system showed that miR-34a could directly regulate the transcriptional activity of PAX6.The ability of invasion and migration was inhibited after overexpression miR-34a.The expression level of PAX6 was down-regulated and the expression of JAK1/STAT3 protein were down-regulated after overexpression the miR-34a.Conclusion:miR-34a targets the expression of PAX6 and regulates the invasion and migration of retinoblastoma cells by JAK1/STAT3 signal pathway.

Objective: To assess fluid-attenuated inversion recovery (FLAIR) vascular hyper-intensity (FVH) and explore its relationship with CT perfusion (CTP) penumbral/infarct core mismatch ratio and diffusion weighted imaging (DWI) final infarct volume in acute ischemic stroke (AIS) patients with middle cerebral artery occlusion (MCAO). Methods: The CTP and MRI images of 38 AIS patients with MCAO were reviewed. The FVH score (longitudinal direction) [FVH score (L)] and FVH score (transverse direction) [FVH score (T)] were quantified on the FLAIR images. The FVH score (L) (range, 0-16) was based on a rostrocaudal extension of FVH and the FVH score (T) (range, 0-3) was based on FVH supply of the occluded MCA territory. The mismatch ratio was calculated from the ratio of the [mean transit time - cerebral blood volume (CBV)] lesion/CBV lesion on the CTP images. The DWI infarct volume was measured on the DWI images. Results: The mismatch ratio was larger for the group of FVH score (L)=7~8 than those of FVH score (L)=5~6 and FVH score (L)=3~4 (p=0.03), whereas the DWI infarct volume was smaller (p=0.04). Similarly, the mismatch ratio of FVH score (T)=2~3 group was larger than FVH score (T)=1 group (p=0.01), whereas the DWI infarct volume was smaller (p=0.02). Both FVH score (L) and FVH score (T) correlated positively with mismatch ratio (P=0.02, P=0.001, respectively), but negatively with DWI infarct volume (P=0.03, P=0.004, respectively). Conclusions: Higher FVH score is associated with larger mismatch ratio and smaller DWI infarct volume in AIS patients with MCAO. FLAIR vascular hyperintensity may represent collateral arterial circulation, and may play a role in protecting the ischemic penumbra.
Infarction, Middle Cerebral Artery

Female ; Gas Chromatography-Mass Spectrometry ; Humans ; Infant, Newborn ; Male ; Metabolism, Inborn Errors ; diagnosis ; Neonatal Screening

Objective To explore the features of patients with acute leukemia (AL) in Hematology Department of Shenzhen Hospital affliated to Beijing University during the past six years. Methods The data of the 1056 acute leukemia dignosed in our department between 2002-2007 were collected and analyzed retrospectively. Results The male patients was predominant (male/female ratio was 1.78). The number of patients with acute myeloid leukemia(AML) was higher than that of patients with acute lymphoblastic leukemia (ALL) (AML/ALL ratio was 1.85). Most of the AML patients were young adult (65 %) and elderly ALL patients were very rare(1.33 %). AL cases were tended to increase gradually by year. The ratio of treatment-related AL in Shenzhen was lower than that reported literature in other countries. The major cause of the treatment-related AL were chemotherapy/radiotherapy and psoriasis treated with bimolane. Conclusion Some of the features of AL patients in China were further confirmed and some new features were also found in this study. These changes should be demonstrated by the next national epidemiology survey of leukemia.