Objective To study the changes of hippocampal caspase-3 and PSD-95 expression levels in the mice exposed to ketamine 30 mg/(kg·d)for three months. Methods Forty C57BL/6 mice were randomly divided into two groups,and the chronic ketamine addiction model was established by giving mice a three month course of daily intraperitoneal injections of ketamine. Immunohistochemical study and Western blot-ting were applied to observe the expression of caspase-3 and PSD-95 protein. Results There were more expression of caspase-3 and less of PSD-95 in ketamine group as detected by immuohistochemistry. Western blotting results showed caspase-3 active fragment level significantly increased com-pared to saline group,but PSD-95 protein level was decreased. Conclusion The increased level of caspase-3 protein and reduced expression of PSD-95 are observed after long-term ketamine administration. These findings may provide an evidence for the neurotoxicity in mouse hippocampus of chronic ketamine addition as a recreational drug.

Objective To investigate the effect of POSTN protein on the proliferation of chondrocytes of tibial plateau in old rats.Methods Cartilage cells collected from the tibial plateau of old rats were cultured in vitro to the third generation.Then the cells were divided into 3 groups:POSTN group,PBS group and POSTN antibody group.The proliferations of the three groups at 24 h,48 h and 72 h were determined by EDU method.The expression of Notch1 protein was detected by immunohistochemistry in all groups at the same time.Female 20-month-old Sprague-Dawley rats were randomly divided into 3 groups:POSTN protein injection group,Phosphate Buffered Saline (PBS) injection group and POSTN antibody injection group.Twelve weeks after the operation,related reagents were injected 3 times consecutively at day 1,day 3,day 5 and EDU was injected into joints at day 1.At 2 weeks after injection,the rats were killed and the knee tibial plateau was taken to observe the proliferation of the cartilage cells.Results At 24 h,there were differences between the three groups O(F=27.32,P=0.017).The proliferation rates of POSTN group [(23±8)％] and PBS group [(21±10)％] were higher than that of POSTN antibody group (16±5)(P=0.003,P=0.011).At 48 h,there were differences between the three groups (F=35.34,P＜0.01).The proliferation rate of POSTN group [(36±11)％] was higher than that of the other groups [(22±6)％],(18±6)％(P=0.021,P＜0.01).At 72h,there were differences between the three groups (F=52.62,P=0.000).The proliferation rate of POSTN group [(56±17)％] was the highest one,the proliferation rate of PBS group [(31±8)％] was the medium,and the POSTN antibody group [(26±7)％] was the lowest one (all P＜0.05).As for Notch1 protein expression in chondrocytes,there were differences between the three groups (F=26.72,P＜0.01).The Notch1 protein was the most frequently expressed in POSTN protein-injection group and the least in the anti-POSTN group.In rats,the proliferation rate of the chondrocytes in the medial tibia plateau of the knee of POSTN protein injection group [(36±14)％],which was the highest,and that of the POSTN antibody injection group [(10 ±4)％] was the lowest (all P＜0.05).Conclusion POSTN protein can promote the proliferation of chondrocytes knee OA rats.POSTN antibody injection has been shown to induce the proliferation of chondrocytes.The POSTN protein may promote the proliferation of chondrocytes by activating the Notch signaling pathway.

Objective:To explore the effects of Alpha-2-macroglobulin-rich serum (A2MRS) on knee post-traumatic osteoarthritis (PTOA).Methods:The knee PTOA models were constructed by transection of the anterior cruciate ligament (ACL) in 80 SD male rats, aged 2 months and weighing from 250 to 300 g, which were randomized into 4 groups ( n=20): a high dose group (A2MRS containing 20 μg/μL A2M administered), a low dose group (A2MRS containing 10 μg/μL A2M administered), a positive control group (normal saline administered), and a blank control group (the knee joint cut pseudooperatively and normal saline administered). HE, toluidine blue staining, safranine O staining, modified Mankin scoring and Osteoarthritis Research Society International (OARSI) scoring were conducted to evaluate and compare the therapeutic effects of A2MRS on the knee PTOA among the 4 groups. Results:The rat cartilage was thinner with patchy and cracked surface, and the chondrocytes were reduced and distributed unevenly in the positive control group, compared with the blank control group. The modified Mankin score (3.89±0.93) and OARSI score (10.05±0.72) in the positive control group were significantly higher than those in the blank control group (0.67±0.07 and 3.10±0.29) ( P<0.05). The rat cartilage was thicker with basically complete and crack-free surface, and the chondrocytes were increased and distributed more evenly in the high dose group and the low dose group, compared with the positive control group. The modified Mankin scores (1.33±0.50 and 1.56±0.53) and OARSI scores (6.30±0.64 and 4.75±0.66) in the high dose group and the low dose group were significantly lower than those in the positive control group ( P<0.05). However, there were no such differences between the high dose group and the low dose group ( P>0.05). Conclusion:A2MRS effectively delays the pathological process of knee PTOA.

Objective To investigate the fluctuations in the population density of Aedes albopictus and changes in the population density of Ae. albopictus in different geographical areas and different breeding habitats in Guangdong Province from 2018 to 2023, so as to provide insights into prevention and control of mosquito-borne infectious diseases in the province. Methods Ae. albopictus surveillance sites were assigned in 1 609 townships (streets) from 121 districts (counties) of 21 cities in Guangdong Province during the period between March and November from 2018 to 2023. The surveillance of the population density of Ae. albopictus was performed once a month in each surveillance site, and once a month in specific settings in cities where dengue were highly prevalent in Guangdong Province from December to February of the next year during the period from 2018 through 2023. Four streets (villages) were selected in each surveillance site according to the geographic orientation, and mosquito ovitraps were assigned in gardens, rooftops or public green belts at residential areas, parks, hospitals and construction sites. All mosquito ovitraps were collected, and the mosquito ovitrap index (MOI) was calculated. The population density of Ae. albopictus was classified into four grades in each surveillance site according to MOI, including no risk, low risk, medium risk and high risk. The risk classification of the Ae. albopictus density was analyzed in each surveillance site each year from 2018 to 2023, and the population density of Ae. albopictus was analyzed at different months and in different geographical areas and breeding habitats. Results A total of 118 241 Ae. albopictus surveillance sites were assigned in 21 cities of Guangdong Province from 2018 to 2023, and there were 68.26% of the surveillance sites with the population density of Ae. albopictus that met the requirements for dengue prevention and control, among which low, medium and high risk surveillance sites accounted for 23.61%, 6.67% and 1.47%. The risk classification of the Ae. albopictus density increased rapidly in Guangdong Province since April to May each year from 2018 to 2023, and then gradually reduced since September to October, with the peak during the period between May and July. The mean MOI was 4.21 at each surveillance site in Guangdong Province during the period from 2018 to 2023, with 4.69, 4.80, 4.38, 3.82, 3.38, and 4.33 from 2018 to 2023, respectively. The MOI was 4.35, 4.43, 3.53 and 3.58 in the Pearl River Delta region, and eastern, western, and northern Guangdong Province, respectively, and was 4.18, 5.44, 4.75, 3.24, 4.27 and 3.70 in residential areas, parks, construction sites, hospitals, waste collection stations, and other breeding habitats, respectively. Conclusions The population density of adult Ae. albopictus peaked in Guangdong Province during the period between May and July from 2018 to 2023, with a high density of Ae. albopictus in the Pearl River Delta region and eastern Guangdong Province. Targeted Ae. albopictus control measures are recommended to be implemented prior to the peak of the Ae. albopictus population density to reduce the development of mosquito-borne infectious diseases.