ObjectiveTo develop a rapid,simple and efficient method for isolating exosomes from cell culture supernatant,so as to promote the application of exosomes in clinical and disease treatment.MethodsA new exosomes extraction system was developed by combining hydroxyl(OH)modified magnetic beads with the polymeric compound Buffer EXD,and the exosomes were extracted from cell culture supernatant by using this system. The expression of exosome marker proteins was detected by Western blot,the particle size and concentration of exosomes were measured by nanoparticles tracking analysis(NTA),and the morphology and structure were determined by transmission electron microscope(TEM). In addition,the extraction methods of exosomes by Buffer EXD system were optimized(pH,Buffer EXD ratio,incubation time,magnetic bead dosage and type),and the effect of exosomes purified by the new system on the proliferation of A549 cells was analyzed by combining cell culture with photomicrograph.ResultsIn exosomes purified by the new system,the expression levels of marker proteins Alix,CD9 and CD81 were high,while the expression level of exosome negative protein Calnexin was low. The exosomes extracted by the new system had a particle size peak of around 100 nm and a classical saucer-like shape. When the new system pH was 5. 0,Buffer EXD concentration was 20%,and 1. 75% OH magnetic beads were incubated with samples for 40 min,the content of marker proteins in exosomes was the highest. Additionally,the exosomes purified by the new system significantly facilitated the proliferation of A549 cells.ConclusionUsing OH-modified magnetic beads as the medium,combined with polymeric compound Buffer EXD,a new system was successfully established,which can isolate exosomes with complete structure,obvious morphological characteristics and biological functions from cell culture supernatant rapidly,simply and efficiently.

[A Review] The irritable bowel syndrome (IBS) is a chronic functional bowel disorder,and its pathogenesis remains unclear. Serotonin is thought to be an important brain-gut axis neurotransmitter,which plays an important role in the gastrointestinal motility,sensation and secretion. Serotonin is closely associatied with IBS and regarded as one of the therapeutic targets. This article reviews the related investigations in the recent years.

18F-FDG PET has been widely used in myocardial oncology and inflammatory imaging.Suppression of physiological uptake in heart is required for accurate diagnosis of some thoracic diseases,cardiac inflammatory diseases and coronary atherosclerosis.There is no unified criteria to reduce myocardial 18F-FDG uptake.This review summarizes the research progress of inhibiting physiological myocardial 18F-FDG uptake by controlling diet,mediating blood glucose and applying drugs.

Objective To examine visceral fat in pathogenesis of coronary heart disease in male adults .Me thods 64-slice spiral CT were measured to separate 50 patient into the following 2 groups:CAD( n =26)and healthy control( n =24).Results Fasting insulin concentration, Insulin resistance index, cholesterol, triglyceride, waist circumference and visceral fat were higher in coronary heart disease group while the lower in healthy control group ( P <0.01 ) .The levels of fasting insulin concentration was posi-tively correlated with visceral fat ( r =0.779 , P <0.01 ) .Conclusions Coronary heart disease is characterized with insulin resist-ance.Fasting insulin concentration and visceral fat are higher in coronary heart disease group than the healthy group , and they may be involved in the pathogenesis of insulin resistance .

Objective To observe and classify the characteristics of optical coherence tomography (OCT) for several common diseases which could lead to submacular choroidal neovascularization (CNV), and to provide the warrant to make the differential diagnosis and treatment of CNV. Methods The data of OCT of 165 patients (187 eyes) with CNV due to AMD, CEC, high myopia and ICNV diagnosed by fundus photography and fundus fluorescein angiography (FFA) were retrospectively analyzed, and the images of OCT were classified considering the results of FFA, and the characteristics of different types of the images were sumerized. Results Well-defined fusiform thickening of retinal pigment epithelial (RPE) and choriocapillary layer in CNV with well-defined border (60 eyes), dispersed backscattering increase in poorly-defined CNV (101 eyes), optic darkspace beneath RPE layer in serous detachment of RPE layer (19 eyes), quickly decreased high backscattering region under RPE layer in hemorrhagic detachment of RPE layer (11 eyes), slight to moderate backscattering region between RPE layer in fibrovascular detachment of RPE layer (10 eyes), and detachment of neurepithelial layer from RPE layer with the optic darkspace between the layers in detachment of neurepithelial layer (45 eyes) were observed. Conclusions The images of OCT for the common diseases which could lead to submacular choroidal neovascularization may be divided into 6 types. Analyzing the characteristics of images of OCT is helpful in differential diagnosis and treatment of CNV.

Objective To investigate the effect of triamcinolone acetonide (TA) with different dosage and excipient on retina. Methods Thirty-two purebred New Zealand white rabbits randomly divided into 4 groups underwent intravitreous injection with TA. Group 1:4 mg TA without excipient; group 2:25 mg TA without excipient; group 3:4 mg TA with excipient; group 4:25 mg TA with excipient. Electroretinography (ERG) was performed on each rabbit before intravitreal injection, 1 week, 1 and 2 months after the injection. All the animals were killed and the eyeballs were extirpated 2 months after the injection, and pathological examinations including light and electron microscopy were performed. Results No significant difference was found in the latent period of ERG at the points of time before and after the injection in all the groups, but the amplitudes of ERG waves was lower in groups containing excipient than that before the treatment (P

Objective To investigate the mutations of the gene in Chinese patients with X linked juvenile retinoschisis (XLRS), and to provide the genetic diagnosis and consultation of heredity for the patients and their families. Methods Genomic DNA was isolated from leukocytes of 29 male patients with XLRS, 38 female carriers and 100 normal controls (the patients and the carriers were from 12 families). All 6 exons of XLRS1 gene were amplified by polymerase chain reaction (PCR) and analyzed by single strand conformation polymorphism (SSCP) assay. The positions and types of XLRS1 gene mutations were determined by direct sequencing. Results Eleven different XLRS1 mutations were identified in these 12 families, including one frameshift mutation due to base loss of the first exon: c.22delT(L9CfsX20), one nonsense mutation due to base loss of the first exon (Trp163X), one splice donor site mutation(c.52+2 T→C; IVS1+2T to C), and eight missense mutation due to base replacement(Ser73Pro, Arg102Gln, Asp145His, Arg156Gly, Arg200Cys, Arg209His, Arg213Gln, and Cys223Arg). No gene mutation was detected in the control group. Four new mutations included frmaeshift mutation(L9CfsX20) and mutations of Asp145His, Arg156Gly, and Trp163X at the fifth exon. A newly discovered non-disease-related polymorphism (NSP) was the c.576C to T (Pro192Pro) change at the sixth exon. Conclusion Eleven different XLRS1 mutations were detected, which is the cause of XLRS in Chinese people. The detection of gene mutations may provide the guidance of genetic diagnosis and the consultation of family heredity for the patients and their families.

ObjectiveTo investigate the cause of clinically missed diagnosis of thyroid microcarcinoma(TMC) and the management. Methods Clinical diagnostic and therapeutic data of 110 cases with TMC operated and confirmed by pathology from Jan. 1985 to Dec. 2000 were analysed. Results Diagnostic positive rates by ultrasonography and freezing section were respectively 58%(15/26) and 66 7%(14/21) in 26 cases diagnosed preoperatively. Diagnostic positive rate of freezing section was 80%(24/30) in 30 cases discovered intraoperatively. Through postoperative pathologic exam,54 cases were confirmed as TMC that was not discovered in 19 cases by intraoperative freezing section.Total or near total thyroidectomy was only performed on 35 cases,lobectomy of one or both lobes on other cases. Follow up rate was 80 1% with time ranging from 6 months to 15 years. One case recurred without mortality.Conclusion The clinical diagnosis of TMC is often difficult to establish. Careful palpation, ultrasonography with fine needle aspiratiou cytology before operation, and thorough exploration of the suspected nodules in operation will help to heighten the diagnostic rate. Total or near total lobectomy fulfils the eradication of TMC.

Objective To investigate the relationship between transfusion transmitted virus (TTV)infection and neonatal hyperbilirubinemia,the effect of TTV infection on the liver function, and analyse the feature of nucleotide sequences in TTV ORF1.Methods Serum TTV DNA,which were from 58 neonates with high direct bilirubin(DB,including 5 with hepatitis Syndrome),92 ones with high indirect bilirubin(IB),and 85 normal ones,was detected using a nested polymerase chain reaction technique(nPCR),electropherosis and sequence analyse,and serum alanine amniotransferase (ALT)was determined in all neonates.Results In DB neonates,TTV DNA were detected in 7 neo- nates(12.1%,including 3 neonates with hepatitis syndrome);in IB and normal ones,1 neonate had positive TTV DNA(1.1% and 1.25),respectively.Even if there were point mutations in Guangdong's TTV,the homology of Guangdong's TTV(GD1-9)and Japanese TTV(N22)ranged from 87.1%～97.8% at nucleotide level.Conclusion TTV infection may be one of important pathogenesis resulting in neonatal hyperbilirubinemia and liver damage in such patients.Guangdong's and Japanese TTV isolates had the same genotype,some gene mutations maybe increase the pathogenicity in TTV.

ObjectiveTo evaluate and compare the prognosis of idiopathic macular holes (IMH) and traumatic macular holes (TMH) treated by pars plana vitrectomy (PPV). Methods The clinical data of 72 IMH eyes and 55 TMH eyes, which were treated by PPV between November 2001 and December 2007,were retrospectively reviewed. The visual outcomes and macular anatomic closure were evaluated, and their relationships with prognostic factors including the size of macular hole (MH), preoperative visual acuity (VA) and duration of disease were analyzed. Results The closure rate of IMH (100. 0%) was significant higher than that of TMH (85.5%) (P=0. 001). The postoperative VA of IMH and TMH were (0. 25±0.02) and (0. 21±0. 21) respectively, both significantly increased compare to their preoperative VA (t=-6. 841, -4. 093; P=0.000). VA-increased IMH and TMH eyes had same VA (χ2=3. 651, P=0.07).Pre-PPV VA≥0. 1 IMH eyes had better outcomes than Pre-PPV VA＜0. 1 IMH eyes (χ2 = 12.04, P=0. 001), while Pre-PPV VA had no effects on TMH outcomes (χ2=0. 371, P=0. 486). IMH eyes with small holes had better outcomes (t=2. 476, P=0. 016), and TMH eyes with small holes had better closure (t= -4. 042, P＜0. 001). The duration of disease had no significant influence on TMH visual (χ2=0. 704,P = 0. 401 ) and anatomic (χ2 = 0. 166, P= 0. 684) outcomes. Conclusions PPV is an effective treatment for MH. The closure rate of IMH is higher than that of TMH. The diameter of MH and preoperative VA are major factors for IMH outcomes, and the duration of disease and preoperative VA have no effects on postoperative VA in TMH.