Toxicity of common biocides used in aquaculture to embryos and larvae of Brachymystax tsinlingensis Li.

Brachymystax tsinlingensis Li is a threatened fish species endemic to China. With the problems of environmental factors and seeding breeding diseases, it is important to further improve the efficiency of seeding breeding and the basis of resource protection. This study investigated the acute toxicity of copper, zinc and methylene blue (MB) on hatching, survival, morphology, heart rate (HR) and stress behaviour of B. tsinlingensis. Eggs (diameter: 3.86 ± 0.07 mm, weight: 0.032 ± 0.004 g) of B. tsinlingensis were selected randomly from artificial propagation and developed from eye-pigmentation-stage embryos to yolk-sac stage larvae (length: 12.40 ± 0.02 mm, weight: 0.03 ± 0.001 g) and exposed to different concentrations of Cu, Zn and MB for 144 h in a series of semi-static toxicity tests. The acute toxicity tests indicated that the 96-h median lethal concentration (LC50 ) values of the embryos and larvae were 1.71 and 0.22 mg l-1 for copper and 2.57 and 2.72 mg l-1 for zinc, respectively, whereas the MB LC50 after 144-h exposure for embryos and larvae were 67.88 and 17.81 mg l-1 , respectively. The safe concentrations of copper, zinc and MB were 0.17, 0.77 and 6.79 mg l-1 for embryos and 0.03, 0.03 and 1.78 mg l-1 for larvae, respectively. Copper, zinc and MB treatments with concentrations greater than 1.60, 2.00 and 60.00 mg l-1 , respectively, led to a significantly low hatching rate and significantly high embryo mortality (P < 0.05), and copper and MB treatments with concentrations greater than 0.2 and 20 mg l-1 led to significantly high larvae mortality (P < 0.05). Exposure to copper, zinc and MB resulted in developmental defects, including spinal curvature, tail deformity, vascular system anomalies and discolouration. Moreover, copper exposure significantly reduced the HR of larvae (P < 0.05). The embryos exhibited an obvious change in behaviour, converting from the normal behaviour of emerging from the membrane head first to emerging tail first, with probabilities of 34.82%, 14.81% and 49.07% under copper, zinc and MB treatments, respectively. The results demonstrated that the sensitivity of yolk-sac larvae to copper and MB was significantly higher than that of embryos (P < 0.05) and that B. tsinlingensis embryos or larvae might be more resistant to copper, zinc and MB than other members of the Salmonidae family, which benefits their resource protection and restoration.

Analysis of the progress of clinical trials for ophthalmic drug in China, 2022 / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To explore the progress of clinical trials for ophthalmic drugs in China in 2022 and discuss its changes with 2014 to 2021, thus providing the latest data reference for the development of new drug and the implementation of clinical trials, and a basis for decision-making.METHODS: In this cross-sectional study, we retrieved the drug clinical trials registration and information disclosure platform of National Medical Products Administration database. Drug clinical trials for eye diseases registered from January 1 to December 31, 2022 were included. Number(proportion)was used to describe the characteristics of clinical trials for ophthalmic drug, the indication, the trial phase, the efficacy and the geographical distribution.RESULTS:A total of 55 clinical trials for ophthalmic drug were included, which accounted for 1.66% of all clinical trials, showing a steady growth trend. Main drug type was chemical drugs with the highest proportion of 58.18%. The top three indications with the most clinical trials were age-related macular degeneration, myopia and dry eye. Two gene drugs emerged in 2022, and 7 drugs carried out ≥2 trials, of which atropine sulfate and recombinant anti-vascular endothelial growth factor(VEGF)humanized monoclonal antibody were the most(7 and 5 respectively). Most trials were in phase I and phase III stages, accounting for 36.36% and 27.27% respectively. The median start-up time of phase I trials in 2022 was 2.72(0.77, 3.47)mo, which was significantly shorter than 3.87(3.00, 6.30)mo of 2014～2021(Z=-2.630, P=0.009), and there were no significant differences between BE, phase II, III, IV comparing with 2014～2021(P&#x003E;0.05).CONCLUSIONS: In 2022, the number and implementation efficiency of clinical trials for ophthalmic drugs in China increased steadily. The indications are mainly fundus disease, myopia and dry eye. Most new drugs are in the early stage of research and development or close to market. Gene therapy drugs began to emerge.