Objective:To establish the method sterility test for moxifloxacin hydrochloride eye drops.Methods:According to the requirements of Chinese Pharmacopoeia(2020 edition,volume Ⅳ),method suitability test of sterility test for moxifloxacin hydrochloride eye drops that treated with using different flushing fluid and adding neutralizer was performed for membrane-filter procedure.Results:The method was accepted with adding 5 mL 2 mol·L-1 magnesium sulfate solution into the culture media as neutralizer and flushing with 300 mL buff-ered sodium Chloride-Peptone Solution pH 7.0.The test groups grew synchronously with the positive strains while the negative control had no strain growth.Conclusion:The established method is effective and feasible and can be used for the sterility test of moxifloxacin hydrochloride eye drops.

Objective:To establish the method sterility test for moxifloxacin hydrochloride eye drops.Methods:According to the requirements of Chinese Pharmacopoeia(2020 edition,volume Ⅳ),method suitability test of sterility test for moxifloxacin hydrochloride eye drops that treated with using different flushing fluid and adding neutralizer was performed for membrane-filter procedure.Results:The method was accepted with adding 5 mL 2 mol·L-1 magnesium sulfate solution into the culture media as neutralizer and flushing with 300 mL buff-ered sodium Chloride-Peptone Solution pH 7.0.The test groups grew synchronously with the positive strains while the negative control had no strain growth.Conclusion:The established method is effective and feasible and can be used for the sterility test of moxifloxacin hydrochloride eye drops.

Aim To investigate the signaling mecha-nisms in endothelial monocyte-activating polypeptide-Ⅱ( EMAP-Ⅱ)-induced increase in blood-tumor barri-er ( BTB ) permeability. Methods Relatively pure cerebral microvessel fragments were obtained from the cortex of 3-5 days old Wistar rats by using careful dis-section, enzyme digestion, and dextran centrifugation. Then, these fragments were seeded on dishes and cul-tured primarily. In vitro BTB models were constructed by co-cultivation of rat brain microvascular endothelial cells ( BMECs) with C6 glioma cells. Confluent mono-layers of co-cultured BMECs were divided randomly in-to 5 groups ( each n=6 ): control, EMAP-Ⅱ, H7 +EMAP-Ⅱ, C3 exoenzyme + EMAP-Ⅱ, and C3 ex-oenzyme + H7 + EMAP-Ⅱ groups. Transendothelial electric resistance values and horseradish peroxidase flux were measured to evaluate changes in the BTB permeability . The expression levels of tight junction-re-lated protein occludin and ZO-1 in BMECs were meas-ured by Western blot. Immunofluorescence was used to identify the expression and distribution of occludin and ZO-1 in BMECs. Also, Western blot were used to de-tect the expression levels of myosin light chain ( MLC) and phosphomyosin light chain ( pMLC ) in BMECs. Results Compared with control group, the BTB per-meability of EMAP-Ⅱ group was increased significant-ly. The expression levels of occludin and ZO-1 in BMECs were significantly decreased, accompanied with marked increase in the expression level of pMLC. These above-mentioned effects of EMAP-Ⅱ were sig-nificantly inhibited by pretreatment with H7 ( an inhib-itor of PKC ) or/and C3 exoenzyme ( an inhibitor of RhoA ) . Conclusion Signaling molecules PKC and RhoA play important roles in EMAP-Ⅱ-induced in-crease in BTB permeability; signaling pathways PKC-pMLC and RhoA-pMLC are involved in this process.

Proteolytic processing of viral polyproteins is indispensible for the lifecycle of coronaviruses. The main protease (M(pro)) of SARS-CoV is an attractive target for anti-SARS drug development as it is essential for the polyprotein processing. M(pro) is initially produced as part of viral polyproteins and it is matured by autocleavage. Here, we report that, with the addition of an N-terminal extension peptide, M(pro) can form a domain-swapped dimer. After complete removal of the extension peptide from the dimer, the mature M(pro) self-assembles into a novel super-active octamer (AO-M(pro)). The crystal structure of AO-M(pro) adopts a novel fold with four domain-swapped dimers packing into four active units with nearly identical conformation to that of the previously reported M(pro) active dimer, and 3D domain swapping serves as a mechanism to lock the active conformation due to entanglement of polypeptide chains. Compared with the previously well characterized form of M(pro), in equilibrium between inactive monomer and active dimer, the stable AO-M(pro) exhibits much higher proteolytic activity at low concentration. As all eight active sites are bound with inhibitors, the polyvalent nature of the interaction between AO-M(pro) and its polyprotein substrates with multiple cleavage sites, would make AO-M(pro) functionally much more superior than the M(pro) active dimer for polyprotein processing. Thus, during the initial period of SARS-CoV infection, this novel active form AOM(pro) should play a major role in cleaving polyproteins as the protein level is extremely low. The discovery of AOM(pro) provides new insights about the functional mechanism of M(pro) and its maturation process.
Coronavirus ; metabolism ; Cysteine Endopeptidases ; Endopeptidases ; metabolism ; Humans ; Peptides ; chemistry ; metabolism ; Polyproteins ; chemistry ; metabolism ; Protein Binding ; SARS Virus ; chemistry ; metabolism ; Viral Proteins