Evaluation of the pathogenicity of a field isolate of Marek's disease virus integrated with retroviral long terminal repeat sequence / 病毒学报

The pathogenicity of a field isolate of Marek's disease virus (MDV) named GXY2 integrated with retroviral long terminal repeat (LTR) sequence from a chicken with MD tumors was evaluated. Experimental chickens were divided into group A, B, C, D and E. The later four groups were vaccinated on one-day-old with CVI988/Rispens for group B and D, with HVT for group C and E, while group A was taken as no-vaccinated control. On 8-day-old, group A, B and C were challenged with GXY2 by intra-abdominal injection, group D and E were kept as un-challenged control. All the birds were raised routinely until 82 days post-challenge (PC), died birds during the experiment and the slaughtered birds at the end of the experiment were necropsied and examined for gross lesions of MD and further confirmed by a developed polymerase chain reaction (PCR) based differential diagnosis technique for avian neoplastic diseases. The results showed that time of onset of MD death of group A, B and C were PC 25, 77 and 29 days with the incidences of visible MD visceral tumors. On PC 82 days, tumor incidences and mortalities of group A, B and C were 72%, 34.8% and 50%, 84%, 21.7% and 20%, respectively. The vaccination protection of CVI988/Rispense and HVT were 51.67% and 30.56% respectively. Among all the visceral organs, heart had the highest tumor incidences (23.5%), and then followed by liver (14.7%) and gizzard (10.3%). The weight-gain of unvaccinated birds was significantly depressed and severe dystrophy of thymus and bursa of Fabricius were also found. The results of the study demonstrated that isolate GXY2 possessed the ability of causing acute tumors and overcoming the protection of the vaccinations of either CVI988/Rispense or HVT.

Pharmacodynamics of compound danshen pH-dependent delayed release pellets in dogs / 药学学报

<p><b>AIM</b>To prepare the compound danshen pH-dependent delayed release pellets and filled them in capsules and then study thier pharmacodynamics.</p><p><b>METHODS</b>The pH-dependent delayed release pellets were prepared by coating with HPMC, Eudragit L-30D-55 and Eudragit L100-Eudragit S100 (1:6), separately, and mixed in proper proportion to prepare the two pH-dependent delayed release systems T1 and T2. The release of delayed release pellets was determined according to the method of China Pharmacopoeia (2000) in the simulated gastrointestinal pH conditions. The pharmacodynamic,parameters were evaluated by serum pharmacology method.</p><p><b>RESULTS</b>The compound danshen pH-dependent delayed release pellets were prepared with the characteristics of pH dependent delayed release profile in vitro. In single oral dose, the pharmacodynamic parameters of rapid release tablets R Emax (%) and Tmax (h) were 34.63% and 0.58 h, respectively. Tmax S of delayed-release pellets T1 and T2 were extended to 2.42, 3.17 h and Emax S (%) were declined to 13.57%, 14.52%. The relative bioavailabilities of T1 and T2 were 99.3%, 133.6% , respectively. In multiple oral doses of R the pharmacodynamic parameter of DF was 7.32 and those T1, T2 DF were 3.40, 3.03, respectively.</p><p><b>CONCLUSION</b>The compound danshen pH-dependent delayed release capsules have characteristics of pH dependent releasing in vitro and characteristics of delayed release in vivo. In multiple oral (loses the DF of delayed release capsules was lower than that of rapid release tablet at steady state.</p>