Anti-scarring effect of rapamycin following filtering surgery in rabbit eyes / 南方医科大学学报

OBJECTIVE@#To study the effect of rapamycin on scar formation in rabbit eyes following filtering operation and explore the possible mechanism.@*METHODS@#Ninety-six healthy adult rabbits were subjected to trabeculectomy of the left eye and subsequently randomly divided into 4 groups (=24) for treatment with castor oil (control) or rapamycin (1%, 3%, or 5%) eye drops of the operated eyes 4 times a day. The morphology and function of the filtering blebs of the rabbits were compared at 7, 14, 21 and 28 days after the operation; at each of the time points, 6 rabbits from each group were euthanized for detection of expressions of proliferating cell nuclear antigen (PCNA) and α-smooth muscle actin (α-SMA) in the tissues in the surgical area using immunohistochemistry. Cultured rabbit subconjunctival fibroblasts (RTFSs) were treated with different concentrations of rapamycin (0.06, 0.25, 1, and 4 mg/L) and the cell apoptosis was detected using flow cytometry.@*RESULTS@#In the first, second and third weeks after the operation, the rate of functional follicle formation was significantly higher in the 3 rapamycin groups than in the control group ( < 0.05), and the number of α- SMA-positive fibroblasts decreased over time in the 3 rapamycin groups. In cultured RTFSs, treatment with rapamycin at different concentrations resulted in increased apoptosis of the cells, and rapamycin above 0.25 mg/L significantly increased the cell apoptosis in a dose-dependent manner.@*CONCLUSIONS@#Rapamycin can inhibit hyperplasia of the filtering passage tissue, helps to preserve the functional filtering blebs and prolong their life span, and induces apoptosis of RTFS.

Anti-scarring effect of rapamycin in rabbits following glaucoma filtering surgery / 南方医科大学学报

OBJECTIVE@#To study the anti- scarring effect of rapamycin in rabbits receiving glaucoma filtering surgery.@*METHODS@#Ninety-six Chinchilla rabbits were randomized equally into 3 rapamycin treatment groups and one control group. All the rabbits underwent trabeculectomy, after which the rabbits in the 3 rapamycin groups were treated with eye drops containing 1%, 3%, or 5% rapamycin in the operated eyes, and those in the control groups were given castor oil 4 times a day. The intraocular pressure (IOP) and inflammatory reaction in the treated eyes were observed, and the PCNA-positive cells in the filtering bleb were detected using immunohistochemistry. RTFs isolated from the Tenon's capsule of the rabbits were cultured , and the expressions of caspase-3, caspase-8, and caspase-9 in the fibroblasts were detected after treatment with different concentrations of rapamycin.@*RESULTS@#The IOP was significantly lower in rapamycin-treated group than in the control group after the surgery ( < 0.05). The counts of the PCNA-positive cells were significantly lower in rapamycin-treated rabbits than in the control group ( < 0.05). Rapamycin treatment dose-dependently increased the expressions of caspase-3 and caspase- 9 at both the mRNA ( < 0.001) and protein ( < 0.001) levels without causing significant changes in the expressions of caspase-8.@*CONCLUSIONS@#Rapamycin can inhibit excessive proliferation of the fibroblasts in the filtering bleb to reduce scar formation after glaucoma filtration surgery in rabbits. Rapamycin also increases the expressions of caspase-3 and caspase-9 to induce apoptosis of the RTFs.

Antimicrobial susceptibility and drug-resistance genes of Yersinia spp. of retailed poultry in 4 provinces of China / 中华预防医学杂志

Objective@#To monitor the antimicrobial resistance and drug-resistance genes of Yersinia enterocolitis, Y. intermedia and Y. frederiksenii recovered from retailed fresh poultry of 4 provinces of China.@*Methods@#The susceptibility of 25 isolated Yersinia spp. to 14 classes and 25 kinds of antibiotics was determined by broth microdilution method according to CLSI (Clinical and Laboratory Standards Institute). The antibiotic resistance genes were predicted with antibiotic resistance genes database (ARDB) using whole genome sequences of Yersinia spp.@*Results@#In all 22 Y. enterocolitis tested, 63.7% (14 isolates), 22.8% (5 isolates), 4.6% and 4.6% of 1 isolates exhibited the resistance to cefoxitin, ampicillin-sulbactam, nitrofurantoin and trimethoprim-sulfamethoxazole, respectively. All the 25 isolates were multi-drug resistant to more than 3 antibiotics, while 64.0% of isolates were resistant to more than 4 antibiotics. A few Y. enterocolitis isolates of this study were intermediate to ceftriaxone and ciprofloxacin. Most Yersinia spp. isolates contained antibiotic resistance genes mdtG, ksgA, bacA, blaA, rosAB and acrB, and 5 isolates recovered from fresh chicken also contained dfrA1, catB2 and ant3ia.@*Conclusion@#The multi-drug resistant Yersinia spp. isolated from retailed fresh poultry is very serious in the 4 provinces of China, and their contained many kinds of drug-resistance genes.

Antimicrobial resistance profiles and genetic diversity of bovine staphylococcus aureus isolated in 5 provinces of China in 2013 / 中华预防医学杂志

<p><b>OBJECTIVE</b>To investigate antimicrobial resistance profiles and genetic diversity of staphylococcus aureus isolated from lactating cows of 5 provinces in China, 2013.</p><p><b>METHODS</b>A total of 680 samples were collected from 15 herds (12 farms, 3 artels) in 5 provinces of China in 2013, including swabs of extramammary sites (bovine teat skin and milking machine liners) and quarter milk samples from lactating cows diagnosed with subclinical mastitis. The antimicrobial resistance of the isolates were tested by broth microdilution method and the genotypes were determined by PFGE (pulsed-field gel electrophoresis) method.</p><p><b>RESULTS</b>A total of 111 isolates were isolated and identified as staphylococcus aureus. Resistance to penicillin (90.1% (100/111)), erythromycin (48.6% (54/111)), ciprofloxacin (36.9% (41/111)), clindamycin (27.9% (31/111)), gentamycin (18.9% (21/111)), chloramphenicol (9.0% (10/111)), tetracycline (7.2% (8/111)) of these strains were observed. All isolates were sensitive to oxacillin, vancomycin and selectrin. 92.8% (103/111) staphylococcus aureus isolates were resistant to at least one antimicrobial. 38.7% (43/111) strains were multi-drug resistant isolates. The resistance rate of isolates in artels (100% (48/48)) was higher than it in farms (87% (55/63)) and the difference was statistically significant (χ(2) = 4.80, P < 0.05). The multi-resistance rate of isolates in artels (54% (26/48)) was higher than it in farms (27% (17/63)) and the difference was also statistically significant (χ(2) = 8.48, P < 0.05). The 111 strains were clustered into 8 types, 6 out of which were consisted of 98% isolates (109/111), and were prevalent in 2 to 9 herds. Every herd had 1 to 4 types, and tend to be comprised by one major type. Most swab isolates were indistinguishable from isolates infecting the mammary gland. There were no relationship between antimicrobial resistance profiles and genotypes of these isolates.</p><p><b>CONCLUSION</b>The drug resistance of staphylococcus aureus isolates associated with lactating cows of 5 provinces in China is serious, especially the isolates collected from artels. A few specialized clones were responsible for most of the cases of bovine mastitis in a single herd and some clones might have a broad geographic distribution.</p>

The influence of negative suction during LASIK on content of retinal amino acids in rabbit / 眼科研究

Background Whether negative suction during excimer laser in situ keratomileusis(LASIK) affect the structure and function of retina or not is in controversy,but it seems that temporary hypertention induced by negative suction is a key factor of impairment of retina in LASIK.ObjectiveThis study attempts to study the influence of transient high intraocular pressure (IOP) during LASIK on the contents of retinal amino acid.MethodsThe both eyes of 45 New Zealand white rabbits were suctioned for different periods (20s,45s,3min) with negative pressure generator during the LASIK to make the instantaneous high IOP models,and LASIK without negative suction was performed in the both eyes of 15 rabbits in the control group.The changes of the contents of retinal amino acids were evaluated with High Performance Liquid Chromatography(HPLC) at 0,7,10,14 and 28 days postoperatively and compared with those of control group.ResultsThere were no statistically significant differences in the contents of retinal amino acids among different time points after operation in negative suction for 20s group and 45s group,respectively(P＞0.05).At negative suction for 3minuts,the content of glutamic acid in retina was significantly increased in comparison with control group in 7,10,14 and 28 days (P＜0.05),and no statistically significant difference was seen in the contents of glutamic acid at postoperative instant group compared with control group(P＞0.05).A statistically significant difference in the contents of glutamine,tryptophan,phenylalanine was revealed among postoperative 10 days,14 days and 28 days groups comparison with control group (P＜0.05).ConclusionThe acute IOP elevation caused by negative suction during LASIK results in the reversible increase of retinal amino acids.The duration of negative suction time influent the reconstruction of retinal structure.