Search

ObjectiveTo determine the virulence of desert-type Leishmania donovani strains through animal infection experiments and to explore preservation methods for maintaining their pathogenicity. Methods The isolated strain was cultured in vitro for 7, 30, 36, 44, 60, 90, and 150 days, respectively， and inoculated into Lagurus lagurus (L.lagurus) with the dose of 2.6×105 per animal by intraperitoneal injection. The spleen coefficient, infection rate, and antibody positive rate of the inoculated animals were detected at day 60 after infection. The desert-type Leishmania donovani strain was further inoculated with Cricetulus migratorius (C.migratorius) and L. lagurus, respectively, for passaging and preservation. The survival time of two kinds of animals and pathogenicity change of the stain in their bodies were compared. Results After inoculation of desert-type Leishmania donovani strains cultured in vitro for 7-150 days, the spleen coefficient of inoculated L.lagurus gradually increased from 1% on day 7 to 2.2% on day 30, which was more than 10 times of the normal spleen coefficient. Additionally, on day 60, the spleen coefficient remained 3 times higher than the normal value. The infection rate and antibody positive rate decreased from 80% on day 7 to 0% on day 60. At 90 days, there were no significant differences between the infected groups and the control group, and all the observed indexes were within the normal range. The survival time of L.lagurus infected with the in vivo passage strain ranged from 1 to 13 months, and half of the infected individuals died within 4 months. In contrast, C.migratorius had a survival time ranging from 5 to 31 months, and half of the infected individuals died within an average of 13.7 months. There was a significant difference in the average time of death between the two groups (t=0.000 1, P0.05). This strain exhibited equal virulence in both animals and remained virulent for up to 4 years after continuous passage. ConclusionWith the prolonged culture time, the virulence of the strain decreases gradually. At 90 d, it has no pathogenicity to L. lagurus. Long-term in vitro culture fails to preserve it's pathogenicity to L.lagurus. Only in vivo inoculation can maintain the virulence of this strain.

Aim: To assess the safety, tolerability, pharmacokinetics (PKs) and pharmacodynamics of HRS‐7535, a novel glucagon‐like peptide‐1 receptor agonist (GLP‐1RA), in healthy participants. Materials and Methods: This phase 1 trial consisted of single‐ascending dose (SAD), food effect (FE) and multiple‐ascending dose (MAD) parts. In the SAD part, participants were randomized (6:2) to receive HRS‐7535 (at doses of 15, 60 and 120 mg; administered orally once daily) or placebo. In the FE part, participants were randomized (8:2) to receive a single dose of 90‐mg HRS‐7535 or placebo, in both fed and fasted states. In the MAD part, participants were randomized (18:6) to receive daily HRS‐7535 (120 mg [30/60/90/120‐mg titration scheme]) or placebo for 28 days. The primary endpoints were safety and tolerability. Results: Nausea and vomiting were the most frequently reported AEs across all three parts. In the SAD part, the median Tmax was 5.98‐5.99 hours and the geometric mean t1/2 was 5.28‐9.08 hours across the HRS‐7535 dosing range. In the MAD part, the median Tmax was 5.98‐10.98 hours and the geometric mean t1/2 was 6.48‐8.42 hours on day 28 in participants on HRS‐7535. PKs were approximately dose‐proportional. On day 29 in the MAD part, the mean (percentage) reduction in body weight from baseline was 4.38 kg (6.63%) for participants who received HRS‐7535, compared with 0.8 kg (1.18%) for those participants who received a placebo. Conclusions: HRS‐7535 exhibited a safety and tolerability profile consistent with other GLP‐1RAs and showed PKs suitable for once‐daily dosing. These findings support further clinical development of HRS‐7535 for type 2 diabetes. [ABSTRACT FROM AUTHOR]