The Differential Impact of Age on Vision-Related Quality of Life across the Visual Impairment Spectrum.

PURPOSE: Visual impairment (VI) can have a detrimental impact on vision-related quality of life (VRQoL), but it is still unclear how this relationship varies with age across the VI spectrum. We determined the age-stratified, cross-sectional, and longitudinal associations between VI severity and VRQoL. DESIGN: The baseline and follow-up Singapore Chinese Eye Studies (SCES-1/-2; 2009-2011 and 2015-2017). PARTICIPANTS: A total of 3068 SCES-1 participants (mean age [standard deviation {SD}]: 59.5 [9.8] years; 50.2% female) and 1919 SCES-2 participants (mean age [SD]: 56.8 [8.3] years; 49.9% female). METHODS: Visual impairment was defined as visual acuity (VA) of > 0.3 logarithm of the minimum angle of resolution (logMAR) units; VI severity as mild-moderate (logMAR scores less than the median of all individuals with VI) and severe (logMAR scores median or greater); and VI incidence as VI absence at baseline, but evident at follow-up. Age was stratified into 40 to 49 years, 50 to 64 years, and ≥65 years. MAIN OUTCOME MEASURES: Rasch-transformed scores from the 32-item Impact of Visual Impairment (IVI) questionnaire were used to measure the "Reading," "Mobility," and "Emotional" domains of VRQoL. Multiple linear regression models determined the age-stratified associations of prevalent and incident VI with all 3 VRQoL outcomes, adjusted for potential confounders. RESULTS: Of the 807 persons with prevalent VI, 55.9% had mild-moderate and 44.1% had severe VI. Compared with no VI, age-stratified analyses showed that VRQoL decrements were significant only in the older age groups (mild-moderate VI: 6.2% and 8.1% reduction in Mobility and Reading scores in those aged ≥ 65 years; severe VI: 8.5% to 13.4% reductions in the 3 VRQoL scores in those aged ≥ 50 years). This interaction with older age became more pronounced with incident VI (N = 168), where decrements in all 3 VRQoL domains were evident only in those aged ≥65 years compared with persons without incident VI. CONCLUSIONS: Our results suggest that the VI-VRQoL associations are driven mainly by older individuals aged ≥65 years, highlighting the need for effective regular screening and early intervention modalities to prevent the presence and onset of VI, and subsequent VRQoL declines, in these individuals.

Association between polymorphism rs11200638 in the HTRA1 gene and the response to anti-VEGF treatment of exudative AMD: a meta-analysis.

BACKGROUND: Anti-angiogenesis treatments are the most commonly used treatments for the vision loss caused by exudative age-related macular degeneration (AMD), in which the anti-vascular endothelial growth factor (VEGF) drugs with ranibizumab and bevacizumab are current standard treatments. However, the outcome of anti-VEGF therapeutics is not uniform in all patients. METHODS: We performed a literature-based meta-analysis including, five published studies relevant to HTRA1 and response to anti-VEGF treatment (bevacizumab or ranibizumab). Summary odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using fixed- and random-effects models. Sensitivity analysis and meta-regression were also performed. Q-statistic test and Egger's test was used to evaluate heterogeneity and publication bias respectively. RESULTS: Overall, no association between the rs11200638 polymorphism in HTRA1 gene and the anti-VEGF treatment response was found in the genotype GG versus AA (OR = 1.06; 95% CI: 0.77 to 1.48; P = 0.98), genotype GA versus AA (OR = 1.11; 95% CI: 0.83 to 1.47; P = 0.93), genotype GG + GA versus AA (OR = 1.22; 95% CI: 0.94 to 1.57; P = 0.09), and allele G versus A (OR = 0.92; 95% CI: 0.78 to 1.08; P = 0.14). In the subgroup analysis by ethnicity Caucasian population, and a significant association was still not observed in all genetic models. Sensitivity analysis indicated the robustness of our findings, and no publication bias was observed in our meta-analysis. CONCLUSIONS: This study shows that there was no association between the polymorphism rs11200638 in HTRA1 gene and response to anti-VEGF treatment of exudative AMD. However, more studies are needed to further prove the conclusion of present study, especially well-designed and high quality randomised controlled trials or intervention studies.

Electroacupuncture of scalp acupoint alleviates cerebral ischemic inflammatory injury by down-regulating RORγt and promoting balance of IL-17A+Th17/FOXP3+Treg in MCAO rats. / 电头针调控RORγt促进IL-17A+Th17/FOXP3+Treg细胞平衡缓解MCAOå¤§é¼ è„‘ç¼ºè¡€ç‚Žæ€§æŸä¼¤çš„ç ”ç©¶.

OBJECTIVES: To observe the effect of electroacupuncture (EA) of scalp acupoint (Dingnieqian-xiexian, MS6) on expression of retinoid-related orphan receptor γT (ROR γ t), interleukin (IL)-17A, IL-10, transfor-ming growth factor-ß1 (TGF-ß1), IL-6, IL-21, and IL-17A+ Thelper cells(Th) 17 and forkhead transcription factor P3 (FOXP3)+ regulatory T cells (Treg) differentiation of ischemic cortex in ischemic stroke rats, so as to explore its molecular mechanisms underlying relief of inflammatory injury of ischemic stroke. METHODS: A total of 120 male SD rats were randomly assigned to sham operation, model, EA, inhibitor, agonist and EA+agonist groups, with 15 rats in each group. The ischemic stroke model was established by occlusion of the left middle cerebral artery according to Longa's methods. For rats of the EA group and EA+agonist group, EA (2 Hz/100 Hz, 1 mA) was applied to bilateral MS6 for 30 min, once daily for 7 days. Rats of the inhibitor group received intraperitoneal injection of solution of SR1001 (RORγt inhibitor) (2.5 mg/mL, 10 mg/kg), once daily for 7 days. Rats of the agonist and EA+agonist groups received intraperitoneal injection of solution of SR1078 (RORγt agonist) (5 mg/mL, 5 mg/kg) before EA, once daily for 7 days. Rats of the sham operation and model groups were grabbed and fixed in the same way with the other groups. The Zea-longa's score, modified neurological severity score (mNSS) and the neurobehavioral score were assessed before and after the intervention. At the end of experiments, the ischemic cortex tissue was collected. The 2, 3, 5-Triphenyltetrazolium chloride (TTC) staining was used to detect the volume of cerebral infarction. The expression of RORγt mRNA was detected by real-time quantitative PCR；the protein expression levels of RORγt, IL-17A, IL-10 and TGF-ß1 were detected by Western blot；the immunoactivity of IL-6 and IL-21 were detected by immunohistochemistry；the fluorescence areas of IL-17A+Th17 and FOXP3+Treg cells were measured by immunofluorescence and their ratio was calculated in the tissue of ischemic cortex. RESULTS: Relevant to the sham operation group, the model group had a significant increase in the Zea-Longa's score, mNSS score, neurobehavioral score, cerebral infarct volume, expression levels of RORγt mRNA and protein, IL-17A protein, IL-6 and IL-21 immunoactivity, IL-17A+Th17 immunofluorescence intensity, and the ratio of IL-17A+Th17/FOXP3+Treg (P<0.01), and an obvious decrease in the expression levels of TGF-ß1 and IL-10 proteins and FOXP3+Treg immunofluorescence intensity (P<0.01). In contrast to the model group, both EA and inhibitor groups had a significant decrease in the Zea-Longa's score, mNSS score, neurobehavioral score, cerebral infarct volume, expression levels of RORγt mRNA and protein, IL-17A protein, IL-6 and IL-21 immunoactivity, IL-17A+Th17 immunofluorescence intensity, and the ratio of IL-17A+Th17/FOXP3+Treg (P<0.01, P<0.05), and a marked increase in the expression levels of TGF-ß1 and IL-10 proteins and FOXP3+Treg immunofluorescence intensity (P<0.05, P<0.01), while the above indicators of the agonist group were all reversed (P<0.01, P<0.05). Comparison between the agonist and EA+agonist groups showed that the Zea-Longa's score, mNSS score, neurobehavioral score, cerebral infarct volume, expression levels of RORγt mRNA and protein, IL-17A protein, IL-6 and IL-21 immunoactivity, IL-17A+Th17 immunofluorescence intensity, and the ratio of IL-17A+Th17/FOXP3+Treg were significantly lower (P<0.01, P<0.05), and the expression of TGF-ß1 and IL-10 proteins and FOXP3+Treg immunofluorescence intensity were obviously higher (P<0.01, P<0.05) in the EA+agonist group than in the agonist group, suggesting that EA intervention can effectively weaken the effects of RORγt agonist. CONCLUSIONS: EA of scalp acupoint MS6 can effectively improve the neurological function, behavior reaction and reduce cerebral infarct volume in ischemic stroke rats, which may be associated with its functions in down-regulating the expression of RORγt and promoting the balance of IL-17A+Th17/FOXP3+Treg to alleviate inflammatory injury after ischemic stroke.

Melatonin ameliorates vascular endothelial dysfunction, inflammation, and atherosclerosis by suppressing the TLR4/NF-κB system in high-fat-fed rabbits.

Vascular endothelial dysfunction (VED) and inflammation contribute to the initiation and progression of atherosclerosis. Melatonin (MLT) normalizes lipid profile, improves endothelial function, and possesses anti-inflammatory properties. However, the precise mechanisms are still unclear. This study investigated whether MLT could ameliorate VED, inflammation, and atherosclerosis by suppressing the Toll-like receptor 4 (TLR4)/nuclear factor kappa B (NF-κB) system in high-fat-fed rabbits. Rabbits were randomly divided into three groups that received a standard diet (control group), high-cholesterol diet (atherosclerosis group), or high-cholesterol diet plus 10 mg/kg/day MLT (MLT group) for 12 wk. After treatment, high-fat diet significantly increased serum lipid and inflammatory markers in rabbits in atherosclerosis group compared with that in control group. In addition, high-fat diet also induced VED and typical atherosclerotic plaque formation and increased intima/media thickness ratio, which were significantly improved by MLT therapy as demonstrated in MLT group. Histological and immunoblot analysis further showed that high-fat diet enhanced the expressions of TLR4, myeloid differentiation primary response protein (MyD88), and NF-κB p65, but decreased inhibitor of NF-κB (IκB) expression. By contrast, MLT therapy decreased the expressions of TLR4, MyD88, and NF-κB p65 and increased IκB expression. This study has demonstrated that MLT ameliorates lipid metabolism, VED, and inflammation and inhibits the progression of atherosclerosis in high-fat-fed rabbits. Moreover, our study indicates for the first time that suppression of the TLR4/NF-κB system in local vasculature with atherosclerotic damage is important for the protective effects of MLT.

Suppression of cAMP/PKA/CREB signaling ameliorates retinal injury in diabetic retinopathy.

The blood-retinal barrier (BRB), homeostasis, neuronal integrity, and metabolic processes are all directly influenced by Müller cells, the most important retinal glial cells. We isolated primary Müller cells from Sprague-Dawley (SD) neonatal rats and treated them with glucose at varying doses. CCK-8 was used to quantify cellular viability, and a TUNEL assay was performed to detect cell apoptosis. ELISA, immunofluorescence, and western blotting were used to assess cAMP/PKA/CREB signaling, Kir4.1, AQP4, GFAP, and VEGF levels, respectively. H&E staining was used to examine histopathological alterations in diabetic retinopathy (DR)-affected retinal tissue in rats. As glucose concentration increases, gliosis of Müller cells became apparent, as evidenced by a decline in cell activity, an increase in apoptosis, downregulation of Kir4.1 level, and overexpression of GFAP, AQP4, and VEGF. Treatments with low, intermediate, and high glucose levels led to aberrant activation of cAMP/PKA/CREB signaling. Interestingly, blocking cAMP and PKA reduced high glucose-induced Müller cell damage and gliosis by a significant amount. Further in vivo results suggested that cAMP or PKA inhibition significantly improved edema, bleeding, and retinal disorders. Our findings showed that high glucose exacerbated Müller cell damage and gliosis via a mechanism involving cAMP/PKA/CREB signaling.

lncRNA FGD5-AS1 acts as a ceRNA to regulate lipopolysaccharide-induced injury via the miR-223-3p-3p/GAS5 axis in cardiomyocytes.

Long noncoding RNAs (lncRNAs) are abnormally expressed in numerous diseases, and they are closely associated with cardiac diseases. However, the role of lncRNAs in lipopolysaccharide (LPS)-induced cardiotoxicity as well as the potential mechanism remain largely unclear. In the present study, IncRNA microarray assays were performed to analyze differential lncRNA expression in LPS-treated cardiomyocytes, and lncRNA FGD5-AS1 was one of the downregulated lncRNAs. H9C2 cells were treated with LPS, and the expression of lncRNA FGD5-AS1 was markedly downregulated. LncRNA FGD5 overexpression decreased the LPS-induced cardiomyocyte apoptosis and inflammation. Bioinformatics analysis and a luciferase reporter assay indicated that lncRNA FGD5-AS1 directly binds to miR-223-3p. A miR-222-3p mimic partially reversed the inhibitory effect of lncRNA FGD5-AS1 on the LPS-induced H9C2 cell apoptosis and inflammatory response. Moreover, miR-223-3p directly targeted growth arrest-specific transcript 5 (GAS5). LncRNA FGD5-AS1 regulated LPS-induced H9C2 cell inflammation and apoptosis via the miR-223-3p/GAS5 axis.

Ferroptosis-A Novel Mechanism With Multifaceted Actions on Stroke.

As a neurological disease with high morbidity, disability, and mortality, the pathological mechanism underlying stroke involves complex processes such as neuroinflammation, oxidative stress, apoptosis, autophagy, and excitotoxicity; but the related research on these molecular mechanisms has not been effectively applied in clinical practice. As a form of iron-dependent regulated cell death, ferroptosis was first discovered in the pathological process of cancer, but recent studies have shown that ferroptosis is closely related to the onset and development of stroke. Therefore, a deeper understanding of the relationship between ferroptosis and stroke may lead to more effective treatment strategies. Herein, we reviewed the mechanism(s) underlying the onset of ferroptosis in stroke, the potential role of ferroptosis in stroke, and the crosstalk between ferroptosis and other pathological mechanisms. This will further deepen our understanding of ferroptosis and provide new approaches to the treatment of stroke.

Utilisation of poor-quality optical coherence tomography scans: adjustment algorithm from the Singapore Epidemiology of Eye Diseases (SEED) study.

PURPOSE: To evaluate the effect of signal strength (SS) on optical coherence tomography (OCT) parameters, and devise an algorithm to adjust the effect, when acceptable SS cannot be obtained. METHODS: 5085 individuals (9582 eyes), aged ≥40 years from the Singapore Epidemiology of Eye Diseases population-based study were included. Everyone underwent a standardised ocular examination and imaging with Cirrus HD-OCT. Effect of SS was evaluated using multiple structural breaks linear mixed-effect models. Expected change for increment in SS between 4 and 10 for individual parameter was calculated. Subsequently we devised and evaluated an algorithm to adjust OCT parameters to higher SS. RESULTS: Average retinal nerve fibre layer (RNFL) thickness showed shift of 4.11 µm from SS of 5 to 6. Above 6, it increased by 1.72 and 3.35 µm to 7 and 8; and by 1.09 µm (per unit increase) above 8 SS. Average ganglion cell-inner plexiform layer (GCIPL) thickness shifted 5.15 µm from SS of 5 to 6. Above 6, increased by 0.94 µm from 7 to 8; and by 0.16 µm (per unit increase) above 8 SS. When compared with reference in an independent test set, the algorithm produced less systemic bias. Algorithm-adjusted average RNFL was 0.549 µm thinner than the reference, while the unadjusted one was 2.841 µm thinner (p<0.001). Algorithm-adjusted and unadjusted average GCIPL was 1.102 µm and 2.228 µm thinner (p<0.001). CONCLUSIONS: OCT parameters can be adjusted for poor SS using an algorithm. This can potentially assist in diagnosis and monitoring of glaucoma when scans with acceptable SS cannot be acquired from patients in clinics.

Ethnic differences in the incidence of pterygium in a multi-ethnic Asian population: the Singapore Epidemiology of Eye Diseases Study.

We evaluated the 6-year incidence and risk factors of pterygium in a multi-ethnic Asian population. Participants who attended the baseline visit of the Singapore Epidemiology of Eye Diseases Study (year 2004-2011) and returned six years later, were included in this study. Pterygium was diagnosed based on anterior segment photographs. Incident pterygium was defined as presence of pterygium at 6-year follow-up in either eye, among individuals without pterygium at baseline. Multivariable logistic regression models were used to determine factors associated with incident pterygium, adjusting for baseline age, gender, ethnicity, body mass index, occupation type, educational level, income status, smoking, alcohol consumption, presence of hypertension, diabetes and hyperlipidemia. The overall age-adjusted 6-year incidence of pterygium was 1.2% (95% confidence interval [CI] 1.0-1.6%); with Chinese (1.9%; 95% CI 1.4%-2.5%) having the highest incidence rate followed by Malays (1.4%; 95% CI 0.9%-2.1%) and Indians (0.3%; 95% CI 0.3-0.7%). In multivariable analysis, Chinese (compared with Indians; odds ratio [OR] = 4.21; 95% CI 2.12-9.35) and Malays (OR 3.22; 95% CI 1.52-7.45), male (OR 2.13; 95% CI 1.26-3.63), outdoor occupation (OR 2.33; 95% CI 1.16-4.38), and smoking (OR 0.41; 95% CI 0.16-0.87) were significantly associated with incident pterygium. Findings from this multi-ethnic Asian population provide useful information in identifying at-risk individuals for pterygium.

Proposal and validation of a new grading system for pterygium (SLIT2).

BACKGROUND/AIMS: To propose and validate a new pterygium grading system based on slit-lamp evaluation. METHODS: This prospective cross-sectional study included 217 patients with pterygium. All patients underwent slit-lamp examination, and slit-lamp photographs were independently graded by two graders twice. A total of eight parameters were evaluated and all parameters were assigned with a score of 1-4 (normal-severe). Intra-rater and inter-rater reliability as determined by weighted Cohen's kappa analysis. RESULTS: A total of 868 independent assessment, based on 217 slit-lamp images, were performed by two graders. For conjunctival assessment, the intra-rater reliability was excellent for body thickness (κ=0.81-0.89) and size at limbus (κ=0.87-0.92), substantial-to-excellent for body vascularity (κ=0.72-0.86), and moderate-to-excellent for body length (κ=0.57-0.81), whereas the inter-rater reliability was excellent for size at limbus (κ=0.86), substantial for body thickness (κ=0.72-0.73) and body vascularity (κ=0.66-0.75), and moderate for body length (κ=0.54-0.57). For corneal assessment, the intra-rater reliability was excellent for all four parameters (κ=0.84-0.90) whereas the inter-rater reliability was excellent for head length (κ=0.86-0.87), substantial-to-excellent for head vascularity (κ=0.78-0.82), substantial for Stocker's line (κ=0.79-0.80) and head thickness (κ=0.67-0.69). The grading system was named SLIT2, which included S tocker's line, S ize at limbus, L ength of head/body, I njection/vascularity of body/head, and T hickness of body/head. CONCLUSION: The proposed SLIT2 grading system, consisting of eight components, may serve as a reliable tool to standardise the reporting of pterygium severity and disease recurrence for clinical and research applications.

Melatonin inhibits macrophage infiltration and promotes plaque stabilization by upregulating anti-inflammatory HGF/c-Met system in the atherosclerotic rabbit: USPIO-enhanced MRI assessment.

Macrophage plays critical roles in the pathogenesis of atherosclerosis (AS), and is an attractive target for detecting and treating vulnerable plaque. Our previous study showed that melatonin (MLT) ameliorated AS by suppressing the pro-inflammatory Toll-like receptor 4/nuclear factor kappa B system in high-fat-fed rabbit. However, it is unknown whether the anti-atherosclerotic properties of MLT are associated with the upregulation of anti-inflammatory hepatocyte growth factor (HGF)/mesenchymal-epithelial transition factor (c-Met) system. In present study, we examined whether MLT could inhibit macrophage infiltration and promote plaque stabilization by upregulating HGF/c-Met system with ultrasmall superparamagnetic iron oxide (USPIO)-enhanced magnetic resonance imaging (MRI) assessment in AS rabbit. Rabbits in this study were randomly divided into three groups and treated with a standard diet, high-fat diet, and high-fat diet plus 10 mg/kg/day MLT for 12 weeks, respectively. MLT treatment significantly reversed spotty signal void in 3D-TOF MRI, standard signal intensity reduction in T2WI MRI and aortic luminal area reduction in 2D-TOF MRI of the atherosclerotic abdominal aorta 72 h after USPIO injection. It also decreased serum interleukin-6 (IL-6), intima/media thickness ratio of the abdominal aorta, CD68 and iron-positive areas in the aortic intima, and increased serum IL-10, HGF and c-Met protein expression and the accumulation of vascular smooth muscle cell and collagen fiber in the aortic intima of AS rabbit. Our data demonstrated that MLT significantly decreased plaque macrophage infiltration and promoted plaque stability in AS rabbit assessed by USPIO-enhanced MRI. Remarkably, it was very first revealed that upregulation of anti-inflammatory HGF/c-Met system might contribute to the atheroprotective mechanisms of MLT.

Normative patterns and factors associated with presbyopia progression in a multiethnic Asian population: the Singapore Epidemiology of Eye Diseases Study.

BACKGROUND/AIM: To investigate normative patterns and factors associated with presbyopia progression in a multiethnic Asian population. METHODS: Malay, Indian and Chinese participants aged 40-80 years who had baseline and 6-year follow-up examinations with subjective refraction data were recruited from the Singapore Epidemiology of Eye Diseases Study. Presbyopia progression was defined as an increase in near addition power of ≥+0.50 dioptre (D) from baseline to follow-up visit. Modified Poisson regression analyses were used to determine baseline factors associated with presbyopia progression. RESULTS: From the eligible 3974 eyes, 2608 eyes were included for final analysis after excluding eyes with a history of cataract surgery (929 eyes) and best-corrected distance visual acuity worse than 20/40 (342 eyes). Overall the mean near addition power change over 6 years was +0.25 D; Malays showed greater change (+0.37 D) compared with Indians (+0.23 D) and Chinese (+0.16 D). After adjusting for baseline age, gender, body mass index, hypertension, cataract, refractive error and daily hours of reading and writing, Malays were more likely to have presbyopia progression compared with Chinese (RR (relative risk)=1.67; 95% CI 1.43 to 1.95; p<0.001) and Indians (RR=1.45; 95% CI 1.25 to 1.68; p<0.001). Individuals aged 60-69 years (RR=0.77; p=0.006) and ≥70 years (RR=0.51; p<0.001) were less likely to progress in presbyopia compared with those aged 40-49. CONCLUSION: In this Asian population, the near addition power change over 6 years was lower than the current near addition prescription guidelines (+0.25 D vs +0.60 D). Our findings may help update near addition prescription guidelines that can be more tailored to Asians.

Bioavailability of salvianolic acid B and effect on blood viscosities after oral administration of salvianolic acids in beagle dogs.

Salvianolic acid B (SalB) is an active component isolated from Chinese herbal medicine Salvia miltiorrhiza. The aim of this study was to investigate the extent of absolute oral bioavailability (F) of SalB in beagle dogs and the effect on blood viscosity after intravenous and oral administration of Salvianolic acids (SAs). A gradient elution HPLC method was developed and validated to determine the concentration of SalB and its three possible metabolites in plasma. After SAs (180 mg/kg, p.o.; 9 mg/kg, i.v.) were given, the AUCs of SalB were 1680 +/- 670 and 7840 +/- 1140 ng/mL.h, respectively. The F of SalB in dogs was calculated to be only 1.07 +/- 0.43%. The blood viscosity was remarkably decreased after a single intravenous injection of SAs (9 mg/kg). However, no significant change of blood viscosity was observed after a single oral administration of SAs (180 mg/kg). The results suggested that the F of SalB was extremely low and single oral administrated SAs had no effect on ameliorating blood viscosity in beagle dogs.

Transport of aripiprazole across Caco-2 monolayer model.

This study aimed to investigate the transport characteristics of aripiprazole. A human intestinal epithelial cell model Caco-2 cell in vitro cultured had been applied to study the transport of aripiprazole. The effects of time, concentration of donor solutions, pH, temperature and P-glycoprotein inhibitor on the transport of aripiprazole were investigated. The determination of aripiprazole was performed by HPLC. It is concluded that aripiprazole is transported through the intestinal mucosa via a passive diffusion mechanism primarily, coexisting with a carrier-mediated transport. The transport of aripiprazole is positively correlated to transport time, pH, and temperature. Papp increased with donor concentrations up to 10 microg x mL(-1), and then decreased for higher concentrations. The P-glycoprotein inhibitor cyclosporine A significantly enhanced the transport amount of aripiprazole.

[Significant role of poloxamer in drug transport across blood-brain barrier].

Poloxamers are found to be an efficient adjuvant with multiple effects and are applied generally in pharmaceutical field. In recent years, it is investigated that poloxamers can increase the permeability of a broad spectrum of drugs through blood-brain barrier (BBB) by means of manifold mechanisms included: (1) inhibiting P-glycoprotein and multidrug-resistance associated protein efflux systems on BBB; (2) adsorbing different apolipoproteins in plasma on the surface of poloxamer-coated nanoparticles, which could interact with BBB through different receptors and mechanisms; (3) connecting to specific ligands and monoclonal antibodies to cross the BBB via specific endogenous transporters localized within the brain capillary endothelium. Significant roles of poloxamer in drug transport across BBB are considered in this review which provides for important guidance to the design of brain-targeted drug delivery system.

[Preparation, characterization of paclitaxel-loaded Pluronic P105 polymeric micelles and in vitro reversal of multidrug resistant tumor].

Drug delivery system (DDS) is a novel approach to overcome multidrug resistance (MDR) in tumors nowadays. This work was designed to investigate a new micellar delivery system for in vitro reversal of resistant ovarian tumor cells, based on a nonionic triblock copolymer Pluronic P105 and paclitaxel (PTX). The PTX-loaded polymeric micelles (P105/PTX) were prepared by thin film-hydration methods. Based on the results of single factor experiments, the P105/PTX micelle formulation was optimized by employing the central composite design-response surface methodology. The physico-chemical properties of the P105/PTX micelles were characterized, including micelle size, drug loading coefficient, in vitro release behavior, etc. The cytotoxicity of the P105/PTX micelles was assessed against human ovarian tumor cell line, SKOV-3/PTX, by a standard 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl (MTT) assay. In order to understand the possible mechanism of Pluronic effects in resistant tumor cells, cellular uptake study of micellar PTX or Rhodamine-123 (R-123) was also carried out. The results showed that the micelle size was about 24 nm with drug loading coefficient of 1.1% and PTX concentration of 700 microg x mL(-1). The cumulative release amount of PTX from the P105/PTX micelles was only 45.4% in 6 h (P < 0.05) and 79.6% in 24 h, whereas Taxol injection in 6 h released 95.2% PTX. The IC50 values of the P105/PTX micelles and Taxol injection against SKOV-3/PTX were 1.14 and 5.11 microg x mL(-1), and resistance reversion index (RRI) was 9.65 and 2.15, respectively. The micellar PTX or R-123 exhibited a significant increase in cellular uptake in resistant SKOV-3/PTX cells compared with free PTX or R-123. These results indicated that PTX could effectively be solubilized by Pluronic P105 block copolymers via thin film-hydration process and formulation optimization, producing nano-scale polymeric micelles with sustained release property in vitro. The P105/PTX micelles were effectively able to reverse resistance to PTX in SKOV-3/PTX tumor cells compared with Taxol injection or free PTX solution, and the enhanced cytotoxicity in the resistant SKOV-3/PTX cell was related to the improved cellular uptake of PTX by Pluronic P105 copolymers.

[Physicochemical stability and purification technology of caffeic acid tetramer from Arnebia euchroma].

OBJECTIVE: To purify caffeic acid tetramer (CAT) with macroporous resin on the basis of its fundamental physicochemical stability research. METHOD: The changes of CAT content were compared by HPLC method before and after the purification process, or while other conditions were altered. RESULT: LK001 was the best one among 7 kinds of macroporous resin in regard of purifying ability. The optimum absorbing technology was the solution concentration at 10 g x L(-1), pH at 4.5, and the flow rate at 3 BV x h(-1). The best eluting technology was 45% ethanol as eluting agent, pH at 5.0, eluting volume at 50 mL after applying super-purified water and 20% ethanol. The yield of product was 3. 6 percent, and the active compound CAT was 58 percent in the product. CONCLUSION: Macroporous resin LK001 is effective in enriching CAT from the crude extracts, thus this method of purification is advisable.

[Effect of carbon dioxide pneumoperitoneum-laparoscopic surgery on tumor seeding and metastases in endometrial cancer].

OBJECTIVE: To explore the influence of carbon dioxide pneumoperitoneum-laparoscopic surgery on tumor cell seeding and metastases in endometrial cancer. METHODS: Twenty patients with endometrial cancer who underwent laparoscopic surgery and 10 patients with endometrial cancer who underwent laparotomic surgery were enrolled. Each patient was in preoperative clinical StageIand the uterus size in each patient was less than 12 weeks of pregnancy. Carbon dioxide pneumoperitoneum was established and maintained with CO2 insufflation at 4 approximately 6 L/min and intraperitoneal pressure of 13 mmHg with an automatic pneumoperitoneum machine. Cytologic examination of peritoneal fluid(at the beginning and end of the operation), CO2 filtrated gas and the lavage fluid of instruments during the laparoscopic surgery were performed. The protein expressions of E-cadherin,beta-catenin,P-selectin,matrix metalloproteinase-2(MMP-2),vascular endothelial growth factor (VEGF),and CD44v6 in tumor tissues before and after the operation were detected by DAKO Envision. RESULTS: There were no case of positive washing cytology in the peritoneal fluid,CO2 filtrated gas, and the lavage fluid of instruments during the laparoscopic surgery. The expressions of E-cadherin and beta-catenin proteins were obviously abnormal in endometrial cancer. The abnormal expressions of E-cadherin and beta-catenin protein between the pre- and post-operations were not significantly different in both the laparoscopic group and the laparotomic group(P>0.05).The changes of abnormal expressions of E-cadherin and beta-catenin protein were no statistical difference between the two groups(P>0.05). The positive protein expressions of P-selectin,MMP-2,VEGF,and CD44v6 were not significantly different between the pre- and post-operations both in the laparoscopic group and the laparotomic group(P>0.05),and there was also no significant difference between the laparoscopic group and the laparotomic group(P>0.05).The follow-up period in the laparoscopic group was 7 approximately 19 (14.25+/-3.65) months and 7 approximately 19 (13.10+/-4.23) months in the laparotomic group. One patient got infection in the urinary system in the laparoscopic group and one patient had lower extremity venous thrombosis in the laparoscopic group.No recurrence was detected in both groups. CONCLUSION: Laparoscopic surgery for endometrial cancer has no effect on protein expressions of E-cadherin,beta-catenin,P-selectin,MMP-2,VEGF,and CD44v6 in tumor tissues. No evidence has been found that CO2 pneumoperitoneum-laparoscopic surgery may favor endometrial cancer cell seeding and metastases.

[Comparison between the characteristics of absorption and pharmacokinetic behavior of ginsenoside Rg1 and ginsenoside Rb, of Panax notoginseng saponins].

To compare the characteristics of absorption and pharmacokinetic behavior of ginsenoside Rg1 (Rg1) with ginsenoside Rb1 (Rb1) of panax notoginseng saponins (PNS), bile excretion of both Rg1 and Rb1 were studied after i.v. and i.g. of PNS solution. Plasma protein binding ratios were studied using equilibrium dialysis method, and referred to pharmacokinetic parameters. It shows that (61.48 +/- 18.30)% dose of Rg1 and (3.94 +/- 1.49)% dose of Rb1 were separately excreted into bile 10 hours after i.v. administration (PNS 50 mg x mL(-1)), and (0.91 +/- 0.51)% dose of Rg1 and (0.055 +/- 0.02)% dose of Rb1 were excreted into bile 12 hours after i.g. administration (PNS 1 500 mg x mL(-1)). Plasma protein binding degrees of Rg1 and Rb1 were 6.56% - 12.74% and 80.1% - 89.69%, respectively. Stomach, intestinal and hepatic throughput efficiency (F(S), F1 and F(H)) for Rg1 were 49.85%, 13.05%, 50.56%, respectively, and 25.82%, 4.18%, 65.77% for Rb1. Therefore, poor intestinal absorption is a primary reason for the low bioavailability of both Rg1 and Rb1. Rg1 possesses relatively high bile excretion and low plasma protein binding rate, in contrast, Rb1 possesses low bile excretion and high plasma protein binding rate. Membrane permeability and elimination rate of Rb1 were lower than that of Rg1, meanwhile, longer MRT and bigger AUC could be found for Rb1.

[Screening of Panax notoginsenoside water in oil microemulsion formulations and their evaluation in vitro and in vivo].

Water in oil (W/O) microemulsion formulation was developed to enhance intestinal absorption of ginsenoside Rb1 (Rb1) of panax notoginseng (PNS). Effects of W/O microemulsions on pharmacokinetics after intraduodenal administration, membrane fluidity and membrane transport of Rb, were studied in rats, liposomes and parallel artificial membrane permeability assay (PAMPA), respectively. Soybean phospholipids/ethanol (SP/EtOH) was selected as surfactant/cosurfactant, together with PNS 400 mg x mL(-1) solution and various kinds of oils, to prepare 11 W/O microemulsions. Most of the microemulsions can enhance Rb1 intestinal absorption significantly. Besides surfactant/cosurfactant, oil also had an effect on the enhanced absorption and the order of enhancement was as follows: glyceryl laurate approximately = isopropyl myristate > isopropyl palmitate > 2-ethylhexanol palmitate. The effection of absorption enhancement by the long chain glyceride ( > C14) is lower than that by the medium chain glyceride (C8 - C14). Most of W/O microemulsions were found to enhance the membrane fluidity of liposomes to different extents. In PAMPA analysis, efficient permeability coefficient (Pe) of diluted-microemulsion (D-ME) is mostly higher than that of PNS solution, which indicated the components of microemulision can facilitate the membrane permeability of the drug. Meanwhile, linearity correlation between Pe and ratio of relative bioavailability (Fr) was acquired for undiluted microemulison (ME). Therefore, W/O microemulsions can enhance intestinal absorption of Rbr, and this effect may be attiributed to its enhancement on membrane fluidity to a certain degree. PAMPA analysis could be brought into not only the investigation of membrane transport of crude drug, but also conditioned preformulation research (e.g. absorption enhancer etc.).