Objective To analyze the effects of tyrosinase on choroidal and retinal thickness and blood flow changes in guinea pigs,and to explore the role of tyrosinase in the development and progression of myopia.Methods A total of 30 three-week-old male tri-colored guinea pigs and 10 albino guinea pigs were selected and divided into four groups:control group(tri-colored hyperopic guinea pigs,with no intervention),albino group(albino myopic guinea pigs,with no inter-vention),myopia group(tri-colored myopic guinea pigs,with no intervention),and injection group[tri-colored hyperopic guinea pigs,injected with tyrosinase inhibitor(6 250 μg·L-1),100 μL per day].The experiment lasted for 4 weeks.The refractive status and axial length(AL)of the guinea pigs in each group were measured,along with ocular biometric param-eters related to axial length[anterior chamber depth,aqueous humor depth(AQD),central corneal thickness,lens diame-ter,vitreous chamber depth(VCD)].Optical coherence tomography was used to measure the retinal thickness,choroidal thickness(ChT),and choroidal blood perfusion(ChBP)in different regions of the guinea pigs.The tyrosinase activity in the vitreous and retina of guinea pigs in each group was measured.The expression levels of neurotransmitters in the vitre-ous and retina of guinea pigs in each group were detected.Results The differences in refractive status between the albi-no group and the control group at 0,2,and 4 weeks of the experiment were statistically significant(F=8.972,P＜0.05).At the 4th week of the experiment,the refractive status of the injection group was lower than that of the control group,and the AL was greater than that of the control group,with statistically significant differences(both P＜0.05).Further analysis of AL-related biometric parameters revealed that only AQD and VCD were associated with the changes in AL of guinea pigs in each group.At the 0th week of the experiment,the average retinal thickness of the control group was greater than that of the albino group,with a statistically significant difference(t=-9.007,P＜0.000 1).Moreover,the differences in reti-nal thickness in the outer retina across different directions and time points were statistically significant(all P＜0.05).The differences in retinal thickness between the control and albino groups were mainly concentrated in the outer retina.The ChT of the albino group was less than that of the control group,with a significant difference between groups(F=4.809,P=0.030).The ChBP of the control group was significantly higher than that of the albino group at 0,2,and 4 weeks of the experiment(all P＜0.05).At the 4th week of the experiment,the tyrosinase activity in the vitreous of the injection,albi-no,and myopia groups was lower than that of the control group,with statistically significant differences(all P＜0.05).The differences in neurotransmitters between the albino and control groups were mainly concentrated in the vitreous.In the retina,the ornithine level in the myopia group was higher than that in the albino and control groups,and the tryptophan levels in the myopia and control groups were higher than that in the albino group,with statistically significant differences(all P＜0.05).Conclusion Tyrosinase plays a crucial role in the development of myopia,regulating the development of refractive status by influencing the physiological properties of the retina and choroid.

Objective To analyze the effects of tyrosinase on choroidal and retinal thickness and blood flow changes in guinea pigs,and to explore the role of tyrosinase in the development and progression of myopia.Methods A total of 30 three-week-old male tri-colored guinea pigs and 10 albino guinea pigs were selected and divided into four groups:control group(tri-colored hyperopic guinea pigs,with no intervention),albino group(albino myopic guinea pigs,with no inter-vention),myopia group(tri-colored myopic guinea pigs,with no intervention),and injection group[tri-colored hyperopic guinea pigs,injected with tyrosinase inhibitor(6 250 μg·L-1),100 μL per day].The experiment lasted for 4 weeks.The refractive status and axial length(AL)of the guinea pigs in each group were measured,along with ocular biometric param-eters related to axial length[anterior chamber depth,aqueous humor depth(AQD),central corneal thickness,lens diame-ter,vitreous chamber depth(VCD)].Optical coherence tomography was used to measure the retinal thickness,choroidal thickness(ChT),and choroidal blood perfusion(ChBP)in different regions of the guinea pigs.The tyrosinase activity in the vitreous and retina of guinea pigs in each group was measured.The expression levels of neurotransmitters in the vitre-ous and retina of guinea pigs in each group were detected.Results The differences in refractive status between the albi-no group and the control group at 0,2,and 4 weeks of the experiment were statistically significant(F=8.972,P＜0.05).At the 4th week of the experiment,the refractive status of the injection group was lower than that of the control group,and the AL was greater than that of the control group,with statistically significant differences(both P＜0.05).Further analysis of AL-related biometric parameters revealed that only AQD and VCD were associated with the changes in AL of guinea pigs in each group.At the 0th week of the experiment,the average retinal thickness of the control group was greater than that of the albino group,with a statistically significant difference(t=-9.007,P＜0.000 1).Moreover,the differences in reti-nal thickness in the outer retina across different directions and time points were statistically significant(all P＜0.05).The differences in retinal thickness between the control and albino groups were mainly concentrated in the outer retina.The ChT of the albino group was less than that of the control group,with a significant difference between groups(F=4.809,P=0.030).The ChBP of the control group was significantly higher than that of the albino group at 0,2,and 4 weeks of the experiment(all P＜0.05).At the 4th week of the experiment,the tyrosinase activity in the vitreous of the injection,albi-no,and myopia groups was lower than that of the control group,with statistically significant differences(all P＜0.05).The differences in neurotransmitters between the albino and control groups were mainly concentrated in the vitreous.In the retina,the ornithine level in the myopia group was higher than that in the albino and control groups,and the tryptophan levels in the myopia and control groups were higher than that in the albino group,with statistically significant differences(all P＜0.05).Conclusion Tyrosinase plays a crucial role in the development of myopia,regulating the development of refractive status by influencing the physiological properties of the retina and choroid.

Objective : To analyze the genome structure and genetic characteristics of IncpGRT1 plasmids from Pseud⁃ omonas , and elucidate its potential transmission risk . Methods : The genomic DNA of the clinical isolate 15420352 was extracted after purification and preservation of the strain , and then the whole genome was sequenced , and then the type of the plasmid was identified . Sequence annotation and comparison of the backbone region and the accessory modules were performed on all five same type sequenced plasmids , including one plasmid p420352 - strA in this study and four from GenBank . The plasmids were annotated by RAST , Plasmidfinder , Blast , ResFinder , and ISfinder. The ORFs of the plasmid were annotated and drug resistance genes were found . Results : All five plasmids were classified as new IncpGRT1 type plasmids . The IncpGRT1 backbone genes or gene loci were in all five plasmids , and they contained an auxiliary replicon besides the primary IncpGRT1 replicon . Five IncpGRT1 plasmids carried at least three different accessory modules , including the srp region , the msr region , and a Tn5053 family transposon . Three resistance genes strA , strB , and mer were obtained in these plasmids , which were involved in resistance to two categories of antibiotics and heavy metals . We also found that these plasmids carried at least one virulence gene msr and five key transporters srp , emrE , mod , phn , and lpt , which could improve the environmental adaptability of the strains . Conclusion The IncpGRT1 plasmids have become the important vector for the accumulation and spread of some drug resistance genes and virulence genes in Pseudomonas , and have improved the environmental adaptability of the strain.

Background::It is controversial whether the apolipoprotein E epsilon 4 allele ( APOE ε4) is a risk gene for human immunodeficiency virus (HIV)-related neurocognitive impairment. This meta-analysis aimed to summarize evidence of the associations between APOE ε4 and cognitive impairment in people living with HIV (PLWH). Methods::Our study conducted a systematic literature search of PubMed, Web of Science, Embase, Google Scholar, and ProQuest for studies published before April 11, 2022 that evaluated associations between APOE ε4 and cognitive impairment in adult PLWH (aged ≥18 years). We calculated pooled odds ratios (ORs) of global cognitive impairment and 95% confidence intervals (CIs) and standardized mean differences (SMDs) for specific cognitive domains between APOE ε4 carriers and non-carriers. Subgroup meta-analyses were used to evaluate the result profiles across different categorical variables. Results::Twenty studies met the inclusion criteria, including 19 that evaluated global cognitive impairment. APOE ε4 was significantly associated with global cognitive impairment in PLWH (OR = 1.36, 95% CI = [1.05, 1.78], number of estimates [ k] = 19, P = 0.02, random effects). Subgroup meta-analysis based percentage of females showed evident intergroup differences in global cognitive performance between ε4 carriers and non-carriers ( P = 0.015). APOE ε4 carriers had lower cognitive test scores than non-carriers in all seven cognitive domains, including fluency (SMD = -0.51, 95% CI = [-0.76, -0.25], P < 0.001, k = 4, I2= 0%), learning (SMD = -0.52, 95% CI = [-0.75, -0.28], P < 0.001, k = 5, I2 = 0%), executive function (SMD = -0.41, 95% CI= [-0.59, -0.23], P < 0.001, k= 8, I2= 0%), memory (SMD=-0.41, 95% CI= [-0.61, -0.20], P < 0.001, k= 10, I2= 36%), attention/working memory (SMD=-0.34, 95% CI= [-0.54, -0.14], P= 0.001, k= 6, I2= 0%), speed of information processing (SMD = -0.34, 95% CI = [-0.53, -0.16], P < 0.001, k = 8, I2 = 0%), and motor function (SMD = -0.19, 95% CI = [-0.38, -0.01], P = 0.04, k = 7, I2 = 0%). Conclusions::Our meta-analysis provides significant evidence that APOE ε4 is a risk genotype for HIV-associated cognitive impairment, especially in cognitive domains of fluency, learning, executive function, and memory. Moreover, the impairment is sex specific. Meta analysis registration::PROSPERO, CRD 42021257775.

We have investigated the effects of repairing knee osteochondral defects in rabbit by using porous polyamide 66/nano-Hydroxyapatite (PA66/n-HA) combination bone marrow mesenchymal stem cells (MSCs). Eighteen 6-month-old New Zealand rabbits were used to produce the models of 4 mm x 4 mm osteochondral defect in the middle trochlea groove of femur. These models were randomly divided into 3 groups: PA66/n-HA + MSCs Group (Group A), PA66/n-HA group (Group B) and Operation control-group (Group C) in which operation for osteochondral defects was performed but neither material nor cells were implanted. The materials in Group A were seeded with MSCs (5 x 10(5)) in vitro before being implanted in to defects. The materials in groups A and B were 0.5 - 0.8 mm lower than normal cartilage. The animals were killed 1 and 4 months after operation. We assessed the effects by means of macroscopic observation, HE staining, toluidine blue staining, immunohistochemistry assay for type I and type II collagen. Group A displayed a little effect at the 1 month, but at the 4th month, Group A showed better results,compared to Groups B and C. At this time point, the repair tissue of Group A was regular; it presented more metachromatic substance visualized by toluidine blue staining, and it expressed type II collagen(+ +) and type I collagen(+). These results demonstrate that the repair tissue in Group A is nearly hyaline cartilage. So we presume that porous PA66/n-HA provides biomechanical support, and at the same time, MSCs enhance the repair effects.
Animals ; Biocompatible Materials ; Bone Substitutes ; chemical synthesis ; Female ; Hydroxyapatites ; Implants, Experimental ; Knee Injuries ; surgery ; therapy ; Male ; Mesenchymal Stem Cell Transplantation ; Nanoparticles ; Nylons ; Porosity ; Rabbits