Vitreous liquefaction is an age-related degenerative change,which will further alter the physicochemical properties of the vitreous and its surrounding tissues,resulting in various related eye diseases.The principal pathologic changes of that are the gradual depletion of hyaluronic acid and the collapse of collagen fibrillar network,with a series of biomechanical changes in vitreous body.This article reviews biomechanical properties of normal vitreous,the current measurements of these properties,formation mechanism and changes of biomechanics properties of vitreous liquefaction and correlation between synchesis and related ocular diseases,which provide insight into the ideas for the effective reduction and treatment of vitreous liquefaction.

Objective To investigate the influencing factors of cognitive impairment in patients with lacunar infarction (LI) and to analyze the features of cognitive impairment at different parts in patients with LI.Methods Patients with LI and normal controls were enrolled in the study.Mini-Mental Status Examination (MMSE) was used to evaluate cognitive impairment.California Verbal Learning Test (CVLT),Verbal Fluency Test (VFT),Benton Judgment of Line Orientation Test (BJLOT),Digit Symbol-Coding subtest (DSCT),Paced Auditory Serial Addition Test (PASAT),and Wisconsin Card Sorting Test (WCST)were used to evaluate attention,information processing speed,memory,verbal fluency,and executive function.Results A total of 98 patients with LI and 20 normal controls were enrolled.Of the 98 patients with LI,31 had cognitive impairment and 67 were cognitively normal.The proportions of hypertension,diabetes,multiple LI,and severe white matter lesions,as well as the level of low-density lipoprotein cholesterol in the CI group were significantly higher than those in the normal controls (all P ＜ 0.05).Multivariate logistic regression analysis showed that hypertension (odds ratio [OR] 5.391,95％ confidence interval [CI] 1.515-19.182; P=0.009),diabetes (OR 4.679,95％ CI 1.428-15.339; P=0.011),multiple LI (OR 6.458,95％ CI 1.797-23.213; P =0.004),and severe white matter lesions (OR 6.724,95％ CI 1.440-27.331; P=0.014) were the independent risk factors for the occurrence of cognitive impairment in patients with LI.Among the 98 patients with LI,56 were pure LI (no white matter lesions),but 5 of them were excluded because they could not complete neuropsychological tests.Finally,51 patients were enrolled and were compared and analyzed with the normal control group.Compared to the normal control group,the number of correct answers of WCST-64 in the corona radiata/semi-oval center group (n =15) reduced significantly,and the number of sustained errors increased significantly (P ＜ 0.05).The scores of verbal fluency,DSCT,PASAT,as well as the number of correct answers and the number of completed categories of WCST-64 decreased significantly in the basal ganglia group (n =20) (all P ＜0.05).The scores of short-term memory and delayed recall,as well as the scores of DSCT and PASAT decreased significantly in the thalamus group (n =16) (all P ＜0.05).Conelusiuns Hypertension,diabetes,multiple LI,and severe white matter lesions are the independent risk factors for occurring cognitive impairment in patients with LI.The corona radiata/semi-oval center infarction is easy to complicate with impaired executive function.Basal ganglia infarction is associated with verbal fluency,information processing speed,attention,and executive function impairment.The cognitive impairment of thalamic infarction is mainly manifested in the memory,attention,and information processing speed.

Objective To investigate the effect of dexmedetomidine on liver function,plasma cytokine levels,and oxidative stress due to ischemia/reperfusion injury in patients undergoing hepatolobectomy.Methods A total of 106 patients who underwent hepatolobectomy in General Hospital of Jizhong Energy Fengfeng Group Co.,Ltd.from January 2014 to January 2016 were enrolled and randomly divided into control group and observation group,with 53 patients in each group.The patients in the observation group were given 1 μg/kg/h dexmedetomidine within 10 minutes,followed by continuous intravenous infusion of 0.5 μg/kg/h dexmedetomidine,and those in the control group were given an equal volume of 0.9％ sodium chloride.The two groups were compared in terms of liver function parameters,plasma cytokine levels,and oxidative stress due to ischemia/reperfusion injury after anesthesia (T1),before abdominal closure (T2),and at 1,4,and 8 hours after surgery (T3,T4,and T5,respectively).The chi-square test was used for comparison of categorical data between groups;the t-test was used for comparison of indices between groups,the sphericity test was used for comparison of indices at different time points,and an analysis of variance was performed for repeated measurement data with P ＜ 0.05.Results The two groups had significantly higher alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels at T2,T3,T4,and T5 than at T1 (ALT:F =43.72 and 44.16,both P ＜ 0.001;AST:F =53.87 and 65.44,both P ＜ 0.001),and the observation group had significantly lower levels than the control group atT2,T3,T4,andT5 (ALT:t =20.54,22.01,36.68,and 38.15,all P＜0.001;AST:t =32.27,41.08,52.82,and71.89,all P ＜ 0.001).The two groups had significantly higher levels of tumor necrosis factor α (TNFα) and interleukin-8 (IL-8) at T3,T4,and T5 than at T1 (TNFα:F =54.37 and 24.75,both P ＜ 0.001;IL-8:F =47.24 and 27.39,both P ＜ 0.001),and the observationgroup had significantly lower levels than the control group at T3,T4,and T5 (TNFα:t =59.39,86.32,and 83.16,all P ＜ 0.001;IL-8:t =74.47,72.29,and 76.67,all P ＜ 0.001).The two groups had a significantly higher level of malondialdehyde at T3,T4,and T5 than at T1 (F =37.65 and 17.44,both P ＜0.001),and the observation group had a significantly lower level than the control group at T3,T4,and T5 (t =17.35,19.11,and 24.12,all P ＜ 0.001).The two groups had a significantly lower level of superoxide dismutase at T3,T4,and T5 than at T1 (F =36.54 and 33.65,both P ＜0.001),and the observation group had a significantly higher level than the control group at T3,T4,and T5 (t =68.64,66.35,and 59.48,all P ＜0.001).Conclusion Dexmedetomidine can effectively inhibit liver injury,reduce the levels of cytokines,and alleviate ischemia/reperfusion injury in patients undergoing hepatectomy.

Objective To investigate the correlations of plasma total homocysteine (tHcy) level and the C677T methylene tetrahydrofolate reductase (MTHFR) polymorphism with vascular dementia (VaD) and Alzheimer's disease (AD).Methods A case control study in 64 AD patients (AD group),72 VaD patients (VaD group) and 56 healthy controls (control group) was under taken.Plasma tHcy level was determined by enzymatic cycling assay.The MTHFR677C/T polymorphism was analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).Results tHcy levels were significantly higher in AD and VaD groups than in control subjects(P＜ 0.05).VaD patients also showed increased levels of tHcy as compared to AD patieuts,but no statistic significance was found(P＞0.05).Logistic regression analysis indicated that tHcy level was a risk factor for dementia (including AD and VaD together)[(OR=1.15),VaD (OR=1.23),AD (OR=1.328)].MTHFR677 TT genotype represented higher plasma tHcy concentrations than CC and CT genotypes(both P＜0.05).The distribution frequency of the T allele of MTHFRC677T was 45.3 ％ (58/128)in AD group,49.0％(51/104)in VaD group and 33.0％(37/112)in control group,and it had significant differences between the three groups (P＜0.05).There was a significant difference in distribution frequency of the T allele of MTHFRC677T between VaD and control group (P＜0.01).The distribution frequency of MTHFR677 genotype (CC/CT/TT) had a significantly difference between the VaD group and the control group(P＜0.01).Conclusions High plasma level of tHcy is closely correlated with AD and VaD.tHcy level is the risk factor for dementia (including AD and VaD together).The polymorphism of MTHFR677C/T affects the plasma tHcy level.The T allele of MTHFRC677T may correlate with VaD,while has no direct correlation with AD.

Objective To observe the effect of memantine on NR1 ,NR2A ,NR2B of N‐methyl‐das‐partate receptor and learning or memory ability in vascular dementia (VaD) rats .Methods Thirty adult male SD rats were randomly divided into sham operation group ,VaD model group and me‐mantine treatment group (10 in each group) .A rat VaD model was established by permanent liga‐tion of bilateral common carotid arteries .Rats in memantine treatment group received gastric me‐mantine 10 mg/(kg · d) 1 week after operation while those in model group received normal sa‐line .Five weeks after operation ,their learning or memory ability was tested by Morris water maze test ,expressions of NR1 ,NR2A and NR2B were detected by Western blot .Results The escape latency was significantly longer whereas the percentage of target quadrant and expression levels of NR1 ,NR2A and NR2B were significantly lower in model group than in sham operation group (P=0 .001 ,P=0 .002 ,P<0 .05) .The learning or memory ability and the expression levels of NR1 ,NR2A and NR2B were significantly higher in memantine treatment group than in model group but still lower in memantine treatment group than in sham operation group ( P< 0 .05) . Conclusion Memantine can improve the learning or memory ability of VaD rats by upregulating the expression of NR1 ,NR2A and NR2B in their hippocampus .

Objective To observe the effect of rosuvastatin and memantine on EPC and learning or memory ability in VaD rats .Methods Forty adult male SD rats were randomly divided into sham operation group ,VaD model group ,memantine treatment group ,rosuvastatin treatment group , and memantine+rosuvastatin treatment group (combined treatment group) (8 in each group) .A VaD model was established by permanent ligation of bilateral common carotid arteries .The ani‐mals in rosuvastatin treatment group ,memantine treatment group and combined treatment group received gastric rosuvastatin 10 mg/(kg · d) ,memantine 10 mg/(kg · d) and memantine 10 mg/(kg · d)+rosuvastatin 10 mg/(kg · d) for 4 weeks while those in model group received gastric normal saline .Five weeks after operation ,the learning or memory ability was tested by Morris water maze test ,the escape latency and percentage of target quadrant were calculated ,the circulat‐ing EPC were detected by flow cytometry ,and the MVD in hippocampaus was assyed with vWF immunostaining .Results Five weeks after operation ,the learning or memory ability was signifi‐cantly lower in model group than in sham operation group (P< 0 .01) whereas the learning or memory ability ,the percentage of circulating EPC and the MVD in hippocampus were significantly higher in 3 treatment groups than in model group (P<0 .05) .Conclusion Rosuvastatin and me‐mantine can effectively improve the learning or memory ability of VaD rats by mobilizing their cir‐culating EPC and increasing the MVD in their hippocampus .However ,the effect of memantine or rosuvastatin does not differ greatly w hen they are used alone .

Objective To study the effect of dimethyl fumarate (DMF) on Aβ-induced oxidative stress by regulating NF-E2-related factor 2 (Nrf2) expression and its mechanism.Methods Rat astrocytes were divided into Aβ group,DMF group,Nrf2 group and Nrf2 +DMF group.Expressions of Nrf2,Nqo1,Ho-1,Keap1 mRNA and HDAC were detected by RT-PCR and Western blot respectively.Results The expression levels of Nrf2,Nqo1 and HO-1 mRNA were significantly lower in Nrf2 group and Nrf2+DMF group than in Aβ group and DMF group (P＜0.05) and were significantly higher in DMF group than in Aβ group (P＜0.05) while the expression level of Keap1 mRNA was significantly lower in DMF group and Nrf2+DMF group than in Aβ group and Nrf2 group (P＜0.05).The expression level of HDAC was significantly lower in DMF group and Nrf2+DMF group than in Aβ group and Nrf2 group (6.41±0.43 vs 9.01±1.54,P＜0.05;6.72±0.30 vs 8.76± 0.74,P＜0.05).Conclusion DMF increases the Nrf2 expression by inhibiting the HDAC expression,thus reducing Aβ-induced oxidative stress in rat astrocytes.

Objective Correctly identify Streptococcus pneumoniae resistant to optochin and other alpha hemolytic streptococcus susceptible to optochin.Methods Optochin susceptibility test, bile resolution test, latex agglutination test as well as some biochemical methods (VITEKCC4-GPI identifying cards,API-Strept identifying bar, VITEK TWO-GPC identifying cards) were applied.Results It was observed that 2 strains(0.3%)of Streptococcus pneumoniae out of 630 were resistant to optochin and 31strains of Streptococci, classfied as alpha hemolytic streptococci, susceptible to optochin, including 13 of S. mitis, 6 of S.oralis, 6 of S. twin, 3 of S. acidominimus, 2 of S.intermedius and 1 of S. constellatus. The inhibition zone of these alpha hemolytic streptococci susceptible sensitive to optochin was within the range of 14-17mm in diameter, in not 20 mm or more than 20 mm, compared with the inhibition zone of most strains of S.pneumoniae. Most of these alpha hemolytic streptococci (93.5%) susceptible to optochin showed highly resistance to benzoxazolecillin,to which most Streptococci (94%) showed sensitivity . Conclusion S.pneumoniae can be effectively identified by bile resolution test and latex agglutination test because of its high specificity with credible test results. API-Strept identifying bar and VITEK TWO-GPC identifying cards can be applied to identify S. pneumoniae resistant to optochin.

Objective To construct a cDNA subtractive library of genes transactivated by c-terminally truncated middle surface protein of hepatitis B virus(MHBs t) with suppression subtractive hybridization technique for cloning genes associated with transactivation. Methods The mRNA was isolated from HepG2 cells transfected with pcDNA3.1(-)-Mt167 and pcDNA3.1(-) empty vectors, respectively, then cDNA was synthesized. After restriction enzyme Rsa I digestion, small-size cDNAs were obtained. Then tester cDNA was divided into two groups and ligated to the specific adaptor 1 and adaptor 2, respectively. After tester cDNA was hybridized with driver cDNA twice and underwent two times of nested PCR and then was subcloned into T/A plasmid vectors to set up the subtractive library. Amplification of the library was carried out with E. coli strain JM109. The cDNA was sequenced and analyzed in GenBank with Blast search after PCR. Results The subtractive library of genes transactivated by MHBs t was constructed successfully. The amplified library contained 94 positive clones. Colony PCR showed that these clones contained 200-800bp inserts. Sequence analysis was performed in 50 clones,and the full length sequences were obtained with bioinformatics method. 23 coding sequences were obtained in total, which consisted of 19 known and 4 unknown ones.Conclusions The obtained sequences may be target genes transactivated by MHBs t, among which some genes coding proteins may involve in cell cycle regulation, immune response and tumour genesis.

Objective To analyze the correlation between serum interleukin-18(IL-18) level and changes of heart function in children with viral myocarditis(VM).Methods Seventy-two cases with VM were selected from Tianjin Children's Hospital.Control group were selected from the patients in surgery outpatient department.The patient group was divided into 3 groups which were named non-heart failure group,heart failure group and cardiogenic shock group.The Pillip Sonos 5500 type echocardiogram was applied to measured the left ventricular fractional shortening(LVFS),ejection fraction (EF),left atrium inner diameter(LAD),left ventricular end diastolic inner diameter (LVEDD)and left ventricular end systolic inner diameter(LVESD) in patient group,descripted function change of their heart.ELISA method was used to measure the content of IL-18 in 15 cases of control group and 36 cases of patient group.All data were analyzed by SPSS 11.5 software.Results 1.The LVESD in shock group were larger than that in non-heart failure group and heart failure group,abnormality probability of LVFS and EF step up from non-heart failure group to heart failure group and to shock group.2.The serum IL-18 level in patient group was higher than that in control group (P