The tree shrew(Tupaia belangeri)has long been proposed as a suitable alternative to non-human primates(NHPs)in biomedical and laboratory research due to its close evolutionary relationship with primates.In recent year...The tree shrew(Tupaia belangeri)has long been proposed as a suitable alternative to non-human primates(NHPs)in biomedical and laboratory research due to its close evolutionary relationship with primates.In recent years,significant advances have facilitated tree shrew studies,including the determination of the tree shrew genome,genetic manipulation using spermatogonial stem cells,viral vector-mediated gene delivery,and mapping of the tree shrew brain atlas.However,the limited availability of tree shrews globally remains a substantial challenge in the field.Additionally,determining the key questions best answered using tree shrews constitutes another difficulty.Tree shrew models have historically been used to study hepatitis B virus(HBV)and hepatitis C virus(HCV)infection,myopia,and psychosocial stress-induced depression,with more recent studies focusing on developing animal models for infectious and neurodegenerative diseases.Despite these efforts,the impact of tree shrew models has not yet matched that of rodent or NHP models in biomedical research.This review summarizes the prominent advancements in tree shrew research and reflects on the key biological questions addressed using this model.We emphasize that intensive dedication and robust international collaboration are essential for achieving breakthroughs in tree shrew studies.The use of tree shrews as a unique resource is expected to gain considerable attention with the application of advanced techniques and the development of viable animal models,meeting the increasing demands of life science and biomedical research.展开更多
Objective:To synthesize magnesium oxide nanoparticles using ethanol extract of shoots of Plicosepalus curviflorus(PC-MgONPs)and evaluate the antimicrobial,antioxidant,and anti-proliferative activities of PC-MgONPs.Met...Objective:To synthesize magnesium oxide nanoparticles using ethanol extract of shoots of Plicosepalus curviflorus(PC-MgONPs)and evaluate the antimicrobial,antioxidant,and anti-proliferative activities of PC-MgONPs.Methods:The green synthesized PC-MgONPs were characterized by ultraviolet-visible(UV),Fourier-transform infrared spectroscopy,zeta potential,energy dispersive X-ray,and scanning electron microscopy.Furthermore,we investigated total antioxidant capacity and antimicrobial and anti-proliferative activities using breast cancer cell lines(MDA-231).Results:The UV spectrum of PC-MgONPs showed a sharp absorption peak at 300 nm.The presence of magnesium,oxygen,and sodium was confirmed by energy dispersive X-ray analysis.Scanning electron microscopy revealed PC-MgONPs as roughly spherical granular structures with sizes ranging from 20.0 to 76.4nm.PC-MgONPs showed considerable antimicrobial activities against Escherichia coli,Staphylococcus aureus,methicillin-resistant Staphylococcus aureus,Pseudomonas aeruginosa and Candida albicans with zones of inhibition of 11-17 mm.In addition,total antioxidant capacity and anti-proliferative activity of PC-MgONPs against MDA-231 cells were dose-dependent.Conclusions:The synthesized PC-MgONPs could be a potent antimicrobial,antioxidant and anti-cancer agent,which needs further investigation.展开更多
We sought to evaluate central corneal thickness（CCT）,corneal endothelial cell density（ECD）and intraocular pressure（IOP）in patients with type 2 diabetes mellitus（DM）and to associate potential differences with d...We sought to evaluate central corneal thickness（CCT）,corneal endothelial cell density（ECD）and intraocular pressure（IOP）in patients with type 2 diabetes mellitus（DM）and to associate potential differences with diabetes duration and treatment modality in a prospective,randomized study.We measured ECD,CCT and IOP of125 patients with type 2 DM（mean age 57.1±11.5 years）and compared them with 90 age-matched controls.Measured parameters were analyzed for association with diabetes duration and glucose control modalities（insulin injection or oral medication）while controlling for age.In the diabetic group,the mean ECD（2511±252 cells/mm^2）,mean CCT（539.7±33.6μm）and mean IOP（18.3±2.5 mmHg）varied significantly from those the control group[ECD：2713±132 cells/mm^2（P〈0.0001）,CCT：525.0±45.3μm（P=0.003）and IOP：16.7±1.8 mmHg（P〈0.0001）].ECD was significantly reduced by about 32 cell/mm^2 for diabetics with duration of〉10 years when compared with those with duration of〈10 years（P〈0.05）.CCT was thicker and IOP was higher for diabetics with duration of〉10 years than those with duration of〈10 years（P〉0.05）.None of the measured parameters was significantly associated with diabetes duration and treatment modality（P〉0.05）.In conclusion,subjects with type 2DM exhibit significant changes in ECD,IOP and CCT,which,however,are not correlated with disease duration or if the patients receive on insulin injection or oral medications.展开更多
The aggregation of amyloid-beta peptide and tau protein dysregulation are implicated to play key roles in Alzheimer's disease pathogenesis and are considered the main pathological hallmarks of this devastating dis...The aggregation of amyloid-beta peptide and tau protein dysregulation are implicated to play key roles in Alzheimer's disease pathogenesis and are considered the main pathological hallmarks of this devastating disease.Physiologically,these two proteins are produced and expressed within the normal human body.However,under pathological conditions,abnormal expression,posttranslational modifications,conformational changes,and truncation can make these proteins prone to aggregation,triggering specific disease-related cascades.Recent studies have indicated associations between aberrant behavior of amyloid-beta and tau proteins and various neurological diseases,such as Alzheimer's disease,Parkinson's disease,and amyotrophic lateral sclerosis,as well as retinal neurodegenerative diseases like Glaucoma and age-related macular degeneration.Additionally,these proteins have been linked to cardiovascular disease,cancer,traumatic brain injury,and diabetes,which are all leading causes of morbidity and mortality.In this comprehensive review,we provide an overview of the connections between amyloid-beta and tau proteins and a spectrum of disorders.展开更多
Dear Editor,I would like to congratulate the author on their excellent paper. With great interest, I read Al-Mohaimeed et al’s study[1]“Factors affecting single-step transepithelial photorefractive keratectomy outco...Dear Editor,I would like to congratulate the author on their excellent paper. With great interest, I read Al-Mohaimeed et al’s study[1]“Factors affecting single-step transepithelial photorefractive keratectomy outcome in the treatment of mild,moderate, and high myopia:a cohort study”.展开更多
</span><b><span style="font-family:Verdana;">Purpose:</span></b><span style="font-family:Verdana;"> </b></span><b> </b><span style=&qu...</span><b><span style="font-family:Verdana;">Purpose:</span></b><span style="font-family:Verdana;"> </b></span><b> </b><span style="font-family:Verdana;">To present the profile of keratoconic contact lens wearers, alongside with per</span><span style="font-family:Verdana;">formance of corneal and scleral rigid gas permeable (RGP) at different stages of keratoconus based on limited diagnostic resources. </span><span style="font-family:Verdana;"><b></span><b><span style="font-family:Verdana;">Methods:</span></b><span style="font-family:Verdana;"> </b></span><b><span> </span></b><span style="font-family:Verdana;">5-year Clinical records of keratoconic corneal and scleral RGP contact lens w</span><span style="font-family:Verdana;">earers were retrieved. Data on age, gender, visual acuity (VA), refraction (RE), stage of keratoconus and mode of correction among other variables w</span></span><span style="font-family:Verdana;">ere</span><span style="font-family:Verdana;"> obtained for analysis. Information pertaining to the outcome in pre and post-fit at different severity w</span><span style="font-family:Verdana;">as</span><span style="font-family:Verdana;"> determined. </span><span style="font-family:""><span style="font-family:Verdana;"><b></span><b><span style="font-family:Verdana;">Results:</span></b><span style="font-family:Verdana;"> </b></span><span style="font-family:Verdana;"> A total of 124 medical records were analyzed, with the age (20.86 ± 9.50 years), gender (58.9% male and 41.1% female), Laterality (57.3% bilateral, 26.6% right eye and left eye as 16.1%) and ethnicity (91.1% Africans and 8.9%</span></span><span style="font-family:""> </span><span style="font-family:Verdana;">Asians). There were no significant differences in effects of lenses (RGP and Scleral lenses) across three stages in visual acuity and in three stages o</span><span style="font-family:""><span style="font-family:Verdana;">f severity H</span><sub><span style="font-family:Verdana;">RGP</span></sub><span style="font-family:Verdana;"> (2) = 1.05, </span><i><span style="font-family:Verdana;">p</span></i><span style="font-family:Verdana;"> = 0.59;</span></span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;">H</span><sub><span style="font-family:Verdana;">Scleral</span></sub></span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;">(1) = 2.24, </span><i><span style="font-family:Verdana;">p</span></i><span style="font-family:Verdana;"> = 0.134. Similar non-significant effect was observed in refractive error correction H</span><sub><span style="font-family:Verdana;">RGP</span></sub></span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;">(2) = 1.62, </span><i><span style="font-family:Verdana;">p</span></i><span style="font-family:Verdana;"> = 0.44:</span></span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;">H</span><sub><span style="font-family:Verdana;">Scleral</span></sub></span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;">(1) = 1.143, </span><i><span style="font-family:Verdana;">p</span></i><span style="font-family:Verdana;"> = 0.285. </span></span><span style="font-family:""><span style="font-family:Verdana;"><b></span><b><span style="font-family:Verdana;">Conclusion:</span></b><span style="font-family:Verdana;"> </b></span><b><span> </span></b><span style="font-family:Verdana;">The profile of KC contact lens wearer was comparable to other studies in developing setting. Keratoconic grading should be based on available resources. Corneal rigid gas permeable and scleral lenses were beneficial t</span><span style="font-family:Verdana;">o keratoconic patients in respect of refractive error correction and visual improvement to keratoconic patient.展开更多
Dear Editor,We read with great interest the recently published article titled“Observation of peripheral refraction in myopic anisometropia in young adults”by Du et al[1].The study conducted at the InEye Hospital of ...Dear Editor,We read with great interest the recently published article titled“Observation of peripheral refraction in myopic anisometropia in young adults”by Du et al[1].The study conducted at the InEye Hospital of Chengdu University of TCM provides valuable insights into the relationship between anisometropia and peripheral refraction in myopic young adults.We commend the authors for their thorough investigation and adherence to ethical guidelines.While the study contributes significantly to our understanding of myopic anisometropia,we would like to draw attention to some limitations that merit consideration for a comprehensive interpretation of the findings.展开更多
AIM:To utilise a comprehensive cognitive battery to gain a better understanding of cognitive performance in anorexia nervosa(AN).METHODS:Twenty-six individuals with AN and 27 healthy control participants matched for a...AIM:To utilise a comprehensive cognitive battery to gain a better understanding of cognitive performance in anorexia nervosa(AN).METHODS:Twenty-six individuals with AN and 27 healthy control participants matched for age,gender and premorbid intelligence,participated in the study.A standard cognitive battery,the Measurement and Treatment Research to Improve Cognition in Schizophrenia Consensus Cognitive Battery,was used to investigate performance on seven cognitive domains with the use of 10 different tasks:speed of processing[Brief Assessment Of Cognition In Schizophrenia:Symbol Coding,Category Fluency:Animal Naming(Fluency)and Trail Making Test:Part A],attention/vigilance[Continuous Performance Test-Identical Pairs(CPT-IP)],working memory[Wechsler Memory Scale(WMS?-Ⅲ):Spatial Span,and Letter-Number Span(LNS)],verbal learning[Hopkins Verbal Learning Test-Revised],visual learning[Brief Visuospatial Memory Test-Revised],reasoning and problem solving[Neuropsychological Assessment Battery:Mazes],and social cognition[Mayer-Salovey-Caruso Emotional Intelligence Test:Managing Emotions].Statistical analyses involved the use of multivariate and univariate analyses of variance.RESULTS:Analyses conducted on the cognitive domain scores revealed no overall significant difference between groups nor any interaction between group and domain score[F(1,45)=0.73,P=0.649].Analyses conducted on each of the specific tasks within the cognitive domains revealed significantly slower reaction times for false alarm responses on the CPT-IP task in AN[F(1,51)=12.80,P<0.01,Cohen’s d=0.982]and a trend towards poorer performance in AN on the backward component of the WMS?-ⅢSpatial Span task[F(1,51)=5.88,P=0.02,Cohen’s d=-0.665].The finding of slower reaction times of false alarm responses is,however,limited due to the small number of false alarm responses for either group.CONCLUSION:The findings are discussed in terms of poorer capacity to manipulate and process visuospatial material in AN.展开更多
AIM:To compare the visual acuity(VA),comfort,and patient preference in a soft toric contact lens(TCL)versus soft spherical contact lens(SCL)in low astigmatic subjects during the contact lens(CL)trial.METHODS:This subj...AIM:To compare the visual acuity(VA),comfort,and patient preference in a soft toric contact lens(TCL)versus soft spherical contact lens(SCL)in low astigmatic subjects during the contact lens(CL)trial.METHODS:This subject-masked,block randomized,2×2 crossover study recruited 40 neophyte subjects(80 eyes)aged 18 to 33 y with astigmatism in the range of 0.75-1.25 D with or without spherical power from-6.00 D to+6.00 D.The participants were scheduled for two days CL trial and were fitted with the best-fit SCL and TCL.After 4 h of wear,they were assessed objectively for high contrast VA and subjective vision,comfort,and preference.RESULTS:The responses of 36 subjects(response rate 90%)with a mean age of 23.02±2.97 y(range 18 to 33 y)were analyzed.One-line improvement of monocular VA in the logMAR chart was reported to TCL as compared to SCL(-0.044±0.06 vs 0.04±0.03 logMAR,P=0.01)but the binocular vision remained similar(-0.12±0.07 vs-0.14±0.04 logMAR,P=0.38).Subjects felt a noticeable difference in clarity when shifted to TCL as compared to the SCL.The satisfaction with vision(vision quality)was significantly better with TCL(P=0.03).The fatigue with TCL was graded less at 2.5±0.6,compared to SCL at 4.6±1.3(P=0.04).Thirty-three participants(91.6%)preferred to use contact lens of which 26 participants(79%)preferred TCL.CONCLUSION:The findings suggest that VA and comfort are better with TCL as compared to SCL which is only observed if the patient was offered both offering SCL with spherical equivalent power alone as the first option can mislead the practitioner;TCL trial should be the first choice of the lens in low-to-moderate astigmatism.展开更多
AIM To examine how self-reported and behavioural impulsivity are related in anorexia nervosa(AN).METHODS Twenty-four females with AN and 25 healthy controls(HC)participant in the study.Self-reported impulsivity was as...AIM To examine how self-reported and behavioural impulsivity are related in anorexia nervosa(AN).METHODS Twenty-four females with AN and 25 healthy controls(HC)participant in the study.Self-reported impulsivity was assessed with the Barratt Impulsiveness Scale(BIS-11).The scale yields three second-order factors:Attentional,motor and non-planning.Behavioural impulsivity was investigated with the continuous performance test(CPT),a computer-based task of sustained attention in which numbers are flashed briefly on screen and participants are required to click the mouse when the same number appears consecutively.The rate of commission and omission errors can be used a measure of behavioural imulsivity.RESULTS AN participants self-reported increased attentional[AN:20.67(3.64),HC:13.88(2.91),P=0.001]and reduced motor impulsivity[AN:11.55(2.28),HC:14.08(2.78),P=0.002].The rate of omission or commission errors on the CPT did not differ between groups(P>0.05).BIS-11 and CPT measures did not significantly correlate,but attentional impulsivity was related to negative mood states in AN(depression:r=0.52,P=0.010,anxiety:r=0.55,P=0.006,stress:r=0.57,P=0.004).CONCLUSION The discrepancy between self-reported and behavioural impulsivity are discussed in terms of perfectionism in AN.Furthermore,it is suggested that improving negative mood states may resolve this inconsistency in AN.展开更多
AIM:To compare the corneal backward light scattering values in type 2 diabetes mellitus(DM)patients with those of age and sex-matched healthy controls.METHODS:The study included 30 patients(30 eyes)with type 2 DM and ...AIM:To compare the corneal backward light scattering values in type 2 diabetes mellitus(DM)patients with those of age and sex-matched healthy controls.METHODS:The study included 30 patients(30 eyes)with type 2 DM and 30 control subjects(30 eyes).Duration of diabetes,most recent hemoglobin A1c levels,along with the status of diabetic retinopathy,and existing medical treatment of all subjects were recorded.All subjects underwent a complete ophthalmologic examination.In addition,backward light scattering(densitometry)was measured to assess changes in corneal transparency using tomography(Pentacam HR).RESULTS:The type 2 DM patients included 12 males and 18 females and control subjects included 16 males and 14 females.The age was 50.40±7.80y(range:40-68y)of the diabetic group and 49.30±9.50y(rang:40-73y)of control group.The diabetic group demonstrated significantly higher mean densitometry values of the anterior(6-10 mm)zone(P=0.047),the total anterior layer(P=0.036)and the total cornea(P=0.043)than control group.The corneal densitometry of the diabetic eyes demonstrated no significant correlation with hemoglobin A1c levels and DM duration.CONCLUSION:Diabetic group has higher densitometry in anterior corneal(6-10 mm)zone,total anterior cornea,and total cornea and with no correlation with hemoglobin A1c levels and DM duration.展开更多
Purpose: To evaluate axial length before and after the photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK). Setting: Alhokama Eye Center, Riyadh Saudi Arabia. Design: A cross-sectional study. Me...Purpose: To evaluate axial length before and after the photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK). Setting: Alhokama Eye Center, Riyadh Saudi Arabia. Design: A cross-sectional study. Methods: The study sample was comprised of 106 eyes of 54 patients. Patients were divided into 2 groups based on whether they had photorefractive surgery (PRK group) or laser in situ keratomiluesis (LASIK group). The intra-group comparison was performed of the changes in axial length before and after surgery using IOLMaster. P Results: There were 76 eyes (39 patients) in the PRK group with the mean age of 25.10 ± 3.47 years, the mean preoperative spherical equivalent of -3.16 ± 1.75 D, and the mean preoperative axial length of 24.79 ± 1.02 mm. In the LASIK group, there were 30 eyes (15 patients) with the mean age of 25.13 ± 4.91 years and the mean preoperative spherical equivalent of -5.58 ± 1.98 D and the mean preoperative axial length of 25.67 ± 1.35 mm. Postoperatively, the mean axial length was 24.70 ± 1.14 mm in the PRK group and 25.60 ± 1.33 mm in the LASIK group. The mean change between the preoperative and postoperative axial length was statically significant in both groups (P Conclusion: There was a statically significant decrease in the axial length measurements after PRK or LASIK for myopia.展开更多
Purpose: To devise a rapid method of isolating the plasma membrane enriched fraction (PMEF) of the bovine retinal pigment epithelial (RPE) cells with Percoll cen-trifugation medium.Methods : The bovine RPE was homogen...Purpose: To devise a rapid method of isolating the plasma membrane enriched fraction (PMEF) of the bovine retinal pigment epithelial (RPE) cells with Percoll cen-trifugation medium.Methods : The bovine RPE was homogenised with a tight fit Dounce homogeniser and centrifuged in a 16. 7% Percoll gradient for 20 minutes. The RPE particulate fractions were characterised in terms of their protein concentrations, Na/K-ATPase and bicarbonate stimulated ATPase activities.Results ; The total protein recovery was 88.7% of the RPE homogenate. The nucleus layer was identified at the first band. The mitochondrial fraction was at the second layer according to its bicarbonate stimulated ATPase activity. The 3rd and 4th bands were enriched with plasma membranes and their Na/K-ATPase activities were 31. 5 and 34.6 μmol/mg/h respectively. The Na/K-ATPase activities were about six times that of the RPE homogenate.Conclusions: A rapid method of isolating the bovine RPE PMEF has been devised which involved a single展开更多
Aim: To evaluate the acceptability, effectivity, and side effects of amonovision spectacle correction designed to reduce accommodation and myopia progression in schoolchildren. Methods: Dominant eyes of 11 year old ch...Aim: To evaluate the acceptability, effectivity, and side effects of amonovision spectacle correction designed to reduce accommodation and myopia progression in schoolchildren. Methods: Dominant eyes of 11 year old children with myopia (- 1.00 to - 3.00 D mean spherical equivalent)were corrected for distance; fellow eyes were uncorrected or corrected to keep the refractive imbalance < 2.00 D. Myopia progression was followed with cycloplegic autorefraction and A-scan ultrasonography measures of vitreous chamber depth (VCD) for up to 30 months. Dynamic retinoscopy was used to assess accommodationwhile reading. Results: All children accommodated to read with the distance corrected (dominant) eye. Thus, the near corrected eye experienced myopic defocus at all levels of accommodation. Myopia progression in the near corrected eyes was significantly slower than in the distance corrected eyes (intereye difference=0.36 D/year (95% CI: 0.54 to 0.19, p=0.0015, n=13); difference in VCD elongation=0.13 mm/year (95% CI: 0.18 to 0.08, p=0.0003, n=13)). After refitting with conventional spectacles, the resultant anisometropia returned to baseline levels after 9- 18 months. Conclusions: Monovision is not effective in reducing accommodation in juvenile myopia. However, myopia progression was significantly reduced in the near corrected eye, suggesting that sustained myopic defocus slows axial elongation of the human eye.展开更多
Background Frozen or dried corneal grafts are commonly used for stromal transplantation such as lamellar keratoplasty （full or partial thickness）, keratophakia, epikeratophakia. Structural properties are important f...Background Frozen or dried corneal grafts are commonly used for stromal transplantation such as lamellar keratoplasty （full or partial thickness）, keratophakia, epikeratophakia. Structural properties are important for the final optical results of these surgeries but the effects of freezing/thawing and drying/rehydration on the properties of the stroma are known little compared with the corneal endothelium, mainly because of lack of non-invasive technique to evaluate the stromal structure. This study aimed to investigate the swelling and structural properties of the bovine corneal stroma following freezing or drying by X-ray diffraction which was a non-invasive technique and could give ultra-structural information in hydrated tissues. Methods Bovine corneas were either frozen at -40~C or dried to constant weight in a dessicator over silica gel. Swelling was carried out by placing the corneas into dialysis tubing and equilibrating them against various concentrations of polyethylene glycol （PEG） to obtain a range of tissue hydrations. This method minimises the loss of soluble tissue components during the swelling process. Synchrotron X-ray diffraction was used to measure the average intermolecular spacing, the interfibrillar spacing and the fibril diameter as a function of hydration. Changes in light scattering were detected using a microdensitometer. Results Freezing and thawing of the cornea caused an increase in light scattering by 63.9% at tissue hydration （H）=3.4, and by 50.0% at H=4.9. Repeated freezing and thawing causes further increased by 38.9% at the second time and another 36.0% at the third time （P 〈0.05）. There was a tendency for both the frozen and the dried comeas to lose some swelling ability, achieving hydrations respectively of 10% and 18% below those of fresh corneas at 0 PEG. There were no changes in the fibril diameters, interfibrillar or intermolecular spacings as measured by X-ray diffraction in the equilibrated fresh, pre-frozen and pre-dried corneas. Conclusions The increase in light scattering and the loss of swelling ability after freezing and thawing probably results from structural changes following the close association of the collagen molecules and fibrils whilst the tissue is in the dry or frozen state. Some unknown changes in the extracellular matrix between the collagen fibrils may also play a role in the light scattering. The equilibration technique may improve the quality of rehydrated corneal graft or lenticules used for corneal surgeries. Chin Med J 2009;122（2）：212-218展开更多
基金supported by the STI2030-Major Projects(2021ZD0200900 to Y.G.Y.)"Light of West China" Program of the Chinese Academy of Sciences(xbzg-zdsys-202302 to Y.G.Y.)
文摘The tree shrew(Tupaia belangeri)has long been proposed as a suitable alternative to non-human primates(NHPs)in biomedical and laboratory research due to its close evolutionary relationship with primates.In recent years,significant advances have facilitated tree shrew studies,including the determination of the tree shrew genome,genetic manipulation using spermatogonial stem cells,viral vector-mediated gene delivery,and mapping of the tree shrew brain atlas.However,the limited availability of tree shrews globally remains a substantial challenge in the field.Additionally,determining the key questions best answered using tree shrews constitutes another difficulty.Tree shrew models have historically been used to study hepatitis B virus(HBV)and hepatitis C virus(HCV)infection,myopia,and psychosocial stress-induced depression,with more recent studies focusing on developing animal models for infectious and neurodegenerative diseases.Despite these efforts,the impact of tree shrew models has not yet matched that of rodent or NHP models in biomedical research.This review summarizes the prominent advancements in tree shrew research and reflects on the key biological questions addressed using this model.We emphasize that intensive dedication and robust international collaboration are essential for achieving breakthroughs in tree shrew studies.The use of tree shrews as a unique resource is expected to gain considerable attention with the application of advanced techniques and the development of viable animal models,meeting the increasing demands of life science and biomedical research.
基金funded by the Researchers Supporting Project Number(RSPD2023R656)King Saud University+1 种基金RiyadhSaudi Arabia。
文摘Objective:To synthesize magnesium oxide nanoparticles using ethanol extract of shoots of Plicosepalus curviflorus(PC-MgONPs)and evaluate the antimicrobial,antioxidant,and anti-proliferative activities of PC-MgONPs.Methods:The green synthesized PC-MgONPs were characterized by ultraviolet-visible(UV),Fourier-transform infrared spectroscopy,zeta potential,energy dispersive X-ray,and scanning electron microscopy.Furthermore,we investigated total antioxidant capacity and antimicrobial and anti-proliferative activities using breast cancer cell lines(MDA-231).Results:The UV spectrum of PC-MgONPs showed a sharp absorption peak at 300 nm.The presence of magnesium,oxygen,and sodium was confirmed by energy dispersive X-ray analysis.Scanning electron microscopy revealed PC-MgONPs as roughly spherical granular structures with sizes ranging from 20.0 to 76.4nm.PC-MgONPs showed considerable antimicrobial activities against Escherichia coli,Staphylococcus aureus,methicillin-resistant Staphylococcus aureus,Pseudomonas aeruginosa and Candida albicans with zones of inhibition of 11-17 mm.In addition,total antioxidant capacity and anti-proliferative activity of PC-MgONPs against MDA-231 cells were dose-dependent.Conclusions:The synthesized PC-MgONPs could be a potent antimicrobial,antioxidant and anti-cancer agent,which needs further investigation.
文摘We sought to evaluate central corneal thickness（CCT）,corneal endothelial cell density（ECD）and intraocular pressure（IOP）in patients with type 2 diabetes mellitus（DM）and to associate potential differences with diabetes duration and treatment modality in a prospective,randomized study.We measured ECD,CCT and IOP of125 patients with type 2 DM（mean age 57.1±11.5 years）and compared them with 90 age-matched controls.Measured parameters were analyzed for association with diabetes duration and glucose control modalities（insulin injection or oral medication）while controlling for age.In the diabetic group,the mean ECD（2511±252 cells/mm^2）,mean CCT（539.7±33.6μm）and mean IOP（18.3±2.5 mmHg）varied significantly from those the control group[ECD：2713±132 cells/mm^2（P〈0.0001）,CCT：525.0±45.3μm（P=0.003）and IOP：16.7±1.8 mmHg（P〈0.0001）].ECD was significantly reduced by about 32 cell/mm^2 for diabetics with duration of〉10 years when compared with those with duration of〈10 years（P〈0.05）.CCT was thicker and IOP was higher for diabetics with duration of〉10 years than those with duration of〈10 years（P〉0.05）.None of the measured parameters was significantly associated with diabetes duration and treatment modality（P〉0.05）.In conclusion,subjects with type 2DM exhibit significant changes in ECD,IOP and CCT,which,however,are not correlated with disease duration or if the patients receive on insulin injection or oral medications.
文摘The aggregation of amyloid-beta peptide and tau protein dysregulation are implicated to play key roles in Alzheimer's disease pathogenesis and are considered the main pathological hallmarks of this devastating disease.Physiologically,these two proteins are produced and expressed within the normal human body.However,under pathological conditions,abnormal expression,posttranslational modifications,conformational changes,and truncation can make these proteins prone to aggregation,triggering specific disease-related cascades.Recent studies have indicated associations between aberrant behavior of amyloid-beta and tau proteins and various neurological diseases,such as Alzheimer's disease,Parkinson's disease,and amyotrophic lateral sclerosis,as well as retinal neurodegenerative diseases like Glaucoma and age-related macular degeneration.Additionally,these proteins have been linked to cardiovascular disease,cancer,traumatic brain injury,and diabetes,which are all leading causes of morbidity and mortality.In this comprehensive review,we provide an overview of the connections between amyloid-beta and tau proteins and a spectrum of disorders.
文摘Dear Editor,I would like to congratulate the author on their excellent paper. With great interest, I read Al-Mohaimeed et al’s study[1]“Factors affecting single-step transepithelial photorefractive keratectomy outcome in the treatment of mild,moderate, and high myopia:a cohort study”.
文摘</span><b><span style="font-family:Verdana;">Purpose:</span></b><span style="font-family:Verdana;"> </b></span><b> </b><span style="font-family:Verdana;">To present the profile of keratoconic contact lens wearers, alongside with per</span><span style="font-family:Verdana;">formance of corneal and scleral rigid gas permeable (RGP) at different stages of keratoconus based on limited diagnostic resources. </span><span style="font-family:Verdana;"><b></span><b><span style="font-family:Verdana;">Methods:</span></b><span style="font-family:Verdana;"> </b></span><b><span> </span></b><span style="font-family:Verdana;">5-year Clinical records of keratoconic corneal and scleral RGP contact lens w</span><span style="font-family:Verdana;">earers were retrieved. Data on age, gender, visual acuity (VA), refraction (RE), stage of keratoconus and mode of correction among other variables w</span></span><span style="font-family:Verdana;">ere</span><span style="font-family:Verdana;"> obtained for analysis. Information pertaining to the outcome in pre and post-fit at different severity w</span><span style="font-family:Verdana;">as</span><span style="font-family:Verdana;"> determined. </span><span style="font-family:""><span style="font-family:Verdana;"><b></span><b><span style="font-family:Verdana;">Results:</span></b><span style="font-family:Verdana;"> </b></span><span style="font-family:Verdana;"> A total of 124 medical records were analyzed, with the age (20.86 ± 9.50 years), gender (58.9% male and 41.1% female), Laterality (57.3% bilateral, 26.6% right eye and left eye as 16.1%) and ethnicity (91.1% Africans and 8.9%</span></span><span style="font-family:""> </span><span style="font-family:Verdana;">Asians). There were no significant differences in effects of lenses (RGP and Scleral lenses) across three stages in visual acuity and in three stages o</span><span style="font-family:""><span style="font-family:Verdana;">f severity H</span><sub><span style="font-family:Verdana;">RGP</span></sub><span style="font-family:Verdana;"> (2) = 1.05, </span><i><span style="font-family:Verdana;">p</span></i><span style="font-family:Verdana;"> = 0.59;</span></span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;">H</span><sub><span style="font-family:Verdana;">Scleral</span></sub></span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;">(1) = 2.24, </span><i><span style="font-family:Verdana;">p</span></i><span style="font-family:Verdana;"> = 0.134. Similar non-significant effect was observed in refractive error correction H</span><sub><span style="font-family:Verdana;">RGP</span></sub></span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;">(2) = 1.62, </span><i><span style="font-family:Verdana;">p</span></i><span style="font-family:Verdana;"> = 0.44:</span></span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;">H</span><sub><span style="font-family:Verdana;">Scleral</span></sub></span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;">(1) = 1.143, </span><i><span style="font-family:Verdana;">p</span></i><span style="font-family:Verdana;"> = 0.285. </span></span><span style="font-family:""><span style="font-family:Verdana;"><b></span><b><span style="font-family:Verdana;">Conclusion:</span></b><span style="font-family:Verdana;"> </b></span><b><span> </span></b><span style="font-family:Verdana;">The profile of KC contact lens wearer was comparable to other studies in developing setting. Keratoconic grading should be based on available resources. Corneal rigid gas permeable and scleral lenses were beneficial t</span><span style="font-family:Verdana;">o keratoconic patients in respect of refractive error correction and visual improvement to keratoconic patient.
文摘Dear Editor,We read with great interest the recently published article titled“Observation of peripheral refraction in myopic anisometropia in young adults”by Du et al[1].The study conducted at the InEye Hospital of Chengdu University of TCM provides valuable insights into the relationship between anisometropia and peripheral refraction in myopic young adults.We commend the authors for their thorough investigation and adherence to ethical guidelines.While the study contributes significantly to our understanding of myopic anisometropia,we would like to draw attention to some limitations that merit consideration for a comprehensive interpretation of the findings.
基金The Jack Brockhoff Foundation(3410)the Dick and Pip Smith Foundation+1 种基金Australian Postgraduate Awardthe David Hay Memorial Fund Award
文摘AIM:To utilise a comprehensive cognitive battery to gain a better understanding of cognitive performance in anorexia nervosa(AN).METHODS:Twenty-six individuals with AN and 27 healthy control participants matched for age,gender and premorbid intelligence,participated in the study.A standard cognitive battery,the Measurement and Treatment Research to Improve Cognition in Schizophrenia Consensus Cognitive Battery,was used to investigate performance on seven cognitive domains with the use of 10 different tasks:speed of processing[Brief Assessment Of Cognition In Schizophrenia:Symbol Coding,Category Fluency:Animal Naming(Fluency)and Trail Making Test:Part A],attention/vigilance[Continuous Performance Test-Identical Pairs(CPT-IP)],working memory[Wechsler Memory Scale(WMS?-Ⅲ):Spatial Span,and Letter-Number Span(LNS)],verbal learning[Hopkins Verbal Learning Test-Revised],visual learning[Brief Visuospatial Memory Test-Revised],reasoning and problem solving[Neuropsychological Assessment Battery:Mazes],and social cognition[Mayer-Salovey-Caruso Emotional Intelligence Test:Managing Emotions].Statistical analyses involved the use of multivariate and univariate analyses of variance.RESULTS:Analyses conducted on the cognitive domain scores revealed no overall significant difference between groups nor any interaction between group and domain score[F(1,45)=0.73,P=0.649].Analyses conducted on each of the specific tasks within the cognitive domains revealed significantly slower reaction times for false alarm responses on the CPT-IP task in AN[F(1,51)=12.80,P<0.01,Cohen’s d=0.982]and a trend towards poorer performance in AN on the backward component of the WMS?-ⅢSpatial Span task[F(1,51)=5.88,P=0.02,Cohen’s d=-0.665].The finding of slower reaction times of false alarm responses is,however,limited due to the small number of false alarm responses for either group.CONCLUSION:The findings are discussed in terms of poorer capacity to manipulate and process visuospatial material in AN.
文摘AIM:To compare the visual acuity(VA),comfort,and patient preference in a soft toric contact lens(TCL)versus soft spherical contact lens(SCL)in low astigmatic subjects during the contact lens(CL)trial.METHODS:This subject-masked,block randomized,2×2 crossover study recruited 40 neophyte subjects(80 eyes)aged 18 to 33 y with astigmatism in the range of 0.75-1.25 D with or without spherical power from-6.00 D to+6.00 D.The participants were scheduled for two days CL trial and were fitted with the best-fit SCL and TCL.After 4 h of wear,they were assessed objectively for high contrast VA and subjective vision,comfort,and preference.RESULTS:The responses of 36 subjects(response rate 90%)with a mean age of 23.02±2.97 y(range 18 to 33 y)were analyzed.One-line improvement of monocular VA in the logMAR chart was reported to TCL as compared to SCL(-0.044±0.06 vs 0.04±0.03 logMAR,P=0.01)but the binocular vision remained similar(-0.12±0.07 vs-0.14±0.04 logMAR,P=0.38).Subjects felt a noticeable difference in clarity when shifted to TCL as compared to the SCL.The satisfaction with vision(vision quality)was significantly better with TCL(P=0.03).The fatigue with TCL was graded less at 2.5±0.6,compared to SCL at 4.6±1.3(P=0.04).Thirty-three participants(91.6%)preferred to use contact lens of which 26 participants(79%)preferred TCL.CONCLUSION:The findings suggest that VA and comfort are better with TCL as compared to SCL which is only observed if the patient was offered both offering SCL with spherical equivalent power alone as the first option can mislead the practitioner;TCL trial should be the first choice of the lens in low-to-moderate astigmatism.
基金supported by the Jack Brockhoff Foundation(L.A.,S.R.,D.C.,A.P.,grant number:3410)the Dick and Pip Smith Foundation(A.P.,L.A.,S.R.,D.C.)+1 种基金an Australian Postgraduate Award(A.P.)the David Hay Memorial Fund Award(A.P.)
文摘AIM To examine how self-reported and behavioural impulsivity are related in anorexia nervosa(AN).METHODS Twenty-four females with AN and 25 healthy controls(HC)participant in the study.Self-reported impulsivity was assessed with the Barratt Impulsiveness Scale(BIS-11).The scale yields three second-order factors:Attentional,motor and non-planning.Behavioural impulsivity was investigated with the continuous performance test(CPT),a computer-based task of sustained attention in which numbers are flashed briefly on screen and participants are required to click the mouse when the same number appears consecutively.The rate of commission and omission errors can be used a measure of behavioural imulsivity.RESULTS AN participants self-reported increased attentional[AN:20.67(3.64),HC:13.88(2.91),P=0.001]and reduced motor impulsivity[AN:11.55(2.28),HC:14.08(2.78),P=0.002].The rate of omission or commission errors on the CPT did not differ between groups(P>0.05).BIS-11 and CPT measures did not significantly correlate,but attentional impulsivity was related to negative mood states in AN(depression:r=0.52,P=0.010,anxiety:r=0.55,P=0.006,stress:r=0.57,P=0.004).CONCLUSION The discrepancy between self-reported and behavioural impulsivity are discussed in terms of perfectionism in AN.Furthermore,it is suggested that improving negative mood states may resolve this inconsistency in AN.
基金The Deputyship for Research&Innovation,Ministry of Education in Saudi Arabia for funding this research work through the project(No.IFKSUOR3-499-1).
文摘AIM:To compare the corneal backward light scattering values in type 2 diabetes mellitus(DM)patients with those of age and sex-matched healthy controls.METHODS:The study included 30 patients(30 eyes)with type 2 DM and 30 control subjects(30 eyes).Duration of diabetes,most recent hemoglobin A1c levels,along with the status of diabetic retinopathy,and existing medical treatment of all subjects were recorded.All subjects underwent a complete ophthalmologic examination.In addition,backward light scattering(densitometry)was measured to assess changes in corneal transparency using tomography(Pentacam HR).RESULTS:The type 2 DM patients included 12 males and 18 females and control subjects included 16 males and 14 females.The age was 50.40±7.80y(range:40-68y)of the diabetic group and 49.30±9.50y(rang:40-73y)of control group.The diabetic group demonstrated significantly higher mean densitometry values of the anterior(6-10 mm)zone(P=0.047),the total anterior layer(P=0.036)and the total cornea(P=0.043)than control group.The corneal densitometry of the diabetic eyes demonstrated no significant correlation with hemoglobin A1c levels and DM duration.CONCLUSION:Diabetic group has higher densitometry in anterior corneal(6-10 mm)zone,total anterior cornea,and total cornea and with no correlation with hemoglobin A1c levels and DM duration.
文摘Purpose: To evaluate axial length before and after the photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK). Setting: Alhokama Eye Center, Riyadh Saudi Arabia. Design: A cross-sectional study. Methods: The study sample was comprised of 106 eyes of 54 patients. Patients were divided into 2 groups based on whether they had photorefractive surgery (PRK group) or laser in situ keratomiluesis (LASIK group). The intra-group comparison was performed of the changes in axial length before and after surgery using IOLMaster. P Results: There were 76 eyes (39 patients) in the PRK group with the mean age of 25.10 ± 3.47 years, the mean preoperative spherical equivalent of -3.16 ± 1.75 D, and the mean preoperative axial length of 24.79 ± 1.02 mm. In the LASIK group, there were 30 eyes (15 patients) with the mean age of 25.13 ± 4.91 years and the mean preoperative spherical equivalent of -5.58 ± 1.98 D and the mean preoperative axial length of 25.67 ± 1.35 mm. Postoperatively, the mean axial length was 24.70 ± 1.14 mm in the PRK group and 25.60 ± 1.33 mm in the LASIK group. The mean change between the preoperative and postoperative axial length was statically significant in both groups (P Conclusion: There was a statically significant decrease in the axial length measurements after PRK or LASIK for myopia.
文摘Purpose: To devise a rapid method of isolating the plasma membrane enriched fraction (PMEF) of the bovine retinal pigment epithelial (RPE) cells with Percoll cen-trifugation medium.Methods : The bovine RPE was homogenised with a tight fit Dounce homogeniser and centrifuged in a 16. 7% Percoll gradient for 20 minutes. The RPE particulate fractions were characterised in terms of their protein concentrations, Na/K-ATPase and bicarbonate stimulated ATPase activities.Results ; The total protein recovery was 88.7% of the RPE homogenate. The nucleus layer was identified at the first band. The mitochondrial fraction was at the second layer according to its bicarbonate stimulated ATPase activity. The 3rd and 4th bands were enriched with plasma membranes and their Na/K-ATPase activities were 31. 5 and 34.6 μmol/mg/h respectively. The Na/K-ATPase activities were about six times that of the RPE homogenate.Conclusions: A rapid method of isolating the bovine RPE PMEF has been devised which involved a single
文摘Aim: To evaluate the acceptability, effectivity, and side effects of amonovision spectacle correction designed to reduce accommodation and myopia progression in schoolchildren. Methods: Dominant eyes of 11 year old children with myopia (- 1.00 to - 3.00 D mean spherical equivalent)were corrected for distance; fellow eyes were uncorrected or corrected to keep the refractive imbalance < 2.00 D. Myopia progression was followed with cycloplegic autorefraction and A-scan ultrasonography measures of vitreous chamber depth (VCD) for up to 30 months. Dynamic retinoscopy was used to assess accommodationwhile reading. Results: All children accommodated to read with the distance corrected (dominant) eye. Thus, the near corrected eye experienced myopic defocus at all levels of accommodation. Myopia progression in the near corrected eyes was significantly slower than in the distance corrected eyes (intereye difference=0.36 D/year (95% CI: 0.54 to 0.19, p=0.0015, n=13); difference in VCD elongation=0.13 mm/year (95% CI: 0.18 to 0.08, p=0.0003, n=13)). After refitting with conventional spectacles, the resultant anisometropia returned to baseline levels after 9- 18 months. Conclusions: Monovision is not effective in reducing accommodation in juvenile myopia. However, myopia progression was significantly reduced in the near corrected eye, suggesting that sustained myopic defocus slows axial elongation of the human eye.
文摘Background Frozen or dried corneal grafts are commonly used for stromal transplantation such as lamellar keratoplasty （full or partial thickness）, keratophakia, epikeratophakia. Structural properties are important for the final optical results of these surgeries but the effects of freezing/thawing and drying/rehydration on the properties of the stroma are known little compared with the corneal endothelium, mainly because of lack of non-invasive technique to evaluate the stromal structure. This study aimed to investigate the swelling and structural properties of the bovine corneal stroma following freezing or drying by X-ray diffraction which was a non-invasive technique and could give ultra-structural information in hydrated tissues. Methods Bovine corneas were either frozen at -40~C or dried to constant weight in a dessicator over silica gel. Swelling was carried out by placing the corneas into dialysis tubing and equilibrating them against various concentrations of polyethylene glycol （PEG） to obtain a range of tissue hydrations. This method minimises the loss of soluble tissue components during the swelling process. Synchrotron X-ray diffraction was used to measure the average intermolecular spacing, the interfibrillar spacing and the fibril diameter as a function of hydration. Changes in light scattering were detected using a microdensitometer. Results Freezing and thawing of the cornea caused an increase in light scattering by 63.9% at tissue hydration （H）=3.4, and by 50.0% at H=4.9. Repeated freezing and thawing causes further increased by 38.9% at the second time and another 36.0% at the third time （P 〈0.05）. There was a tendency for both the frozen and the dried comeas to lose some swelling ability, achieving hydrations respectively of 10% and 18% below those of fresh corneas at 0 PEG. There were no changes in the fibril diameters, interfibrillar or intermolecular spacings as measured by X-ray diffraction in the equilibrated fresh, pre-frozen and pre-dried corneas. Conclusions The increase in light scattering and the loss of swelling ability after freezing and thawing probably results from structural changes following the close association of the collagen molecules and fibrils whilst the tissue is in the dry or frozen state. Some unknown changes in the extracellular matrix between the collagen fibrils may also play a role in the light scattering. The equilibration technique may improve the quality of rehydrated corneal graft or lenticules used for corneal surgeries. Chin Med J 2009;122（2）：212-218
