OBJECTIVE: To investigate the availability of bone defect repair by degradable porous polycaprolactam (PCL) as the carrier of bone morphogenetic protein (BMP). METHODS: Three different kinds of bone substitutes, including decalcified bone matrix, PCL-BMP compounds and simple PCL, were implanted into the radial bone defects in 36 rabbits, and in the other 12 rabbits the bone defects were left untreated as control. X-ray examination, X-ray morphometry, histological and electron microscopic observation were performed at different time after operation. RESULTS: The quantity of new bone formation in PCL-BMP group was prior to that in simple PCL group. The pattern and speed of bone defect repair in PCL-BMP group were similar to those in decalcified bone matrix. Electron microscopic observation showed that the PCL-BMP group degraded faster than simple PCL group, which was more suitable for bone repair. CONCLUSION: PCL is a good carrier of BMP with potential for clinical use.
ObjectiveTo investigate the expression of interleukin-18（IL-18）and signal transducers and activators of transcription 5（STAT5）in retina of 4-24-week-old diabetic rats, and explore the potential molecular mechanisms involved in diabetic retinopathy (DR).MethodsRetinal gene expression profile of healthy and 8-week-old diabetic rats was established with restriction fragment differential displaypolymerase chained reaction (RFDD-PCR), and the differences was analyzed by bioinformatics. IL-18 and STAT5 were filtrated as the candidate genes of DR. The expression of IL-18 and STAT5 in retina of diabetic rats with the age of 4, 8, and 24 weeks was observed by semi-quantitative reverse transcriptase-polymerase chain reaction（RT-PCR）.ResultsThe result of RFDD-PCR showed:expression of IL-18 was higher in healthy retina than that in diabetic one; expression of STAT5 was not found in healthy rats but in diabetic ones. The result of RT-PCR showed：compared with the normal, high expression of IL-18 was found in 4-week diabetic retina, reduced in 8-week one, and decreased to the lowest in 24-week one. The expression of STAT5 was not observed in healthy or 4week diabetic retina, but occurred in 8-week one, and increased in 24-week one. ConclusionThe expression of IL-18 and the activation of STAT5 may relate to the occurrance of DR. The expression of IL-18 doesn′t depend on the activation of STAT5. (Chin J Ocul Fundus Dis, 2005,21:258-260)
Objective To investigate the genetic interaction of HLA-DQB1 promoter and coding alleles in the pathogenesis of Vogt-Koyanagi-Harada syndrome (VKH). Methods Eighty-eight Chinese Han patients with VKH and eighty-eight non-VKH normal controls were enrolled in this study. DNA was extracted from white blood cells of the subjects by phenolchloroform method. Thirteen alleles were genotyped by polymerase chain reaction-sequence-specific primers (PCR-SSP), polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) and clone-sequencing was applied to determine the polymorphisms of the promoter and coding regions of HLA-DQB1 gene. Chromas and Bioedit software were used to analyze the sequences of the promoter of HLA-DQB1. Chi-square test and Fisher exact test were the statistical methods. Relationships among single nucleotide polymorphism (SNP) in the promoter and coding region were analyzed. Results Twelve of thirteen already known HLA-DQB1 alleles were genotyped by PCR-SSP in VKH patients. The most frequent allele in VKH patients was HLA-DQB10401 (0.318, 56∶176) which was significantly higher in patients than that in normal controls (0.045, 8∶176) (chi;2＝44.00, P＝0.000, OR＝9.8). So was for HLA-DQB10303 (0.068 vs. 0.006, chi;2＝9.67, P＝0.002, OR＝12.81). In contrast, the frequency of HLA-DQB10601 (0.017 vs.0.096, chi;2＝10.39, P＝0.001, OR＝0.16) and HLA-DQB10302 (0.062 vs. 0.193,chi;2＝13.48, P＝0.000, OR＝0.28) in VKH patients were significantly lower than normal controls. Twelve SNP were found in all subjects. The frequency of C allele at position -189C/A in VKH patients was significantly higher than that in controls (0.324 vs. 0.074, chi;2＝45.92, P＝0.000). However, the frequency of G allele at position -227G/A in VKH patients was significantly lower than that in the normal controls (0.011 vs. 0.108, chi;2＝15.63,P＝0.000). The frequency of combination of susceptible alleles in promoter and coding area （-189C and HLA-DQB10401） in VKH patients was statistically higher than that in controls, the frequency of combination of resistant alleles in control (-227G and HLA-DQB10601) was higher than that in VKH patients. Conclusions The specific interactions of SNP in the promoter and coding alleles of HLA-DQB1 are associated with the pathogenesis of VKH.
Objectives To study the relationships between methylenetetrahydrofolate reductase(MTHFR ) gene polymorphism and diabetic retinopathy (DR) in Chinese Han race． Methods With polymerase chain reaction and restriction fragment length polymorphism (PCR-FLP), MTHFR gene 677 T mutation (cytosine is replaced by thymine in No. 677 site) was detected in 85 health controls, 62 with DR and 117 without DR of type 2 diabetics comfrimed by ophthalmoscope． Results The frequency of MTHFR variant genotypes and alleles of DR in Chinese Han race．patients were signigicantly higher than those without retinopathy and healthy controls (Plt;0．01)． Conclusions The results suggested that MTHFRgene C677T mutation was probably one of the genetic risk factors of diabetic retinopathy in Chinese Han rase． (Chin J Ocul Fundus Dis, 2001,17:198-200
Objective To investigate the polymorphism of the vitamin D receptor gene (VDR)TaqⅠin relation to diabetic retinopathy. Method Fragment length discrepant allele specific PCR(FLDAS-PCR) were used to determine VDR genetypes in 158 patients with diabetic retinopathy and in 198 normal subjects. Results The frequency distribution of VDR genotypes in diabetic retinopathy patients was 106 (67.1%) in TT, 33(20.9%) in Tt, 19(12.0%) in tt; and in normal persons was 165 (83.3%) in TT, 23(11.6%) in Tt, 10 (5.1%) in tt. There was a significant difference between diabetic retinopathy patients and normal persons in distribution of VDR gene TaqⅠgenotypes(Plt;0.05). Conclusions There is some distribution alterations of VDR gene polymorphism in diabetic retinopathy patients. (Chin J Ocul Fundus Dis, 2006, 22: 94-96)
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 polhism (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 Trarr;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. (Chin J Ocul Fundus Dis, 2006, 22: 77-81)
Objective To probe the association between HLA-B27 subtype and acute anterior uveitis(AAU). Methods The HLA-B27 gene of 49 AAu patients were inspected by means of polymerase chain reaction(PCR), and the B27 subtypes of AAU patients were analyzed by means of DNA sequencing and simulated nucleotide hybridization in computer. Results Twenty-nine(59.39%)of 49 AAU patients were B27 positive, and among them 13 (44.00%)were B2704 and 16(56.00%)B27052 in subtypes．No statistically significant difference in most clinical features were found between the patients with B2704 and B27052.In B27 pasitive patients,8 (seven is B27052 and one is B2704) of them were complicatde with ankylosing spondylitis(AS). Conclusions The AAU patients with either B2704 or B27052 have similar clinical feature.The B27052 gene may be an important factor for complicated AS in AAU patients. (Chin J Ocul Fundus Dis, 1999, 15: 139-142)
Polymer micelles formed by self-assembly of amphiphilic polymers are widely used in drug delivery, gene delivery and biosensors, due to their special hydrophobic core/hydrophilic shell structure and nanoscale. However, the structural stability of polymer micelles can be affected strongly by environmental factors, such as temperature, pH, shear force in the blood and interaction with non-target cells, leading to degradations and drug leakage as drug carriers. Therefore, researches on the structural integrity and in vivo distribution of micelle-based carriers are very important for evaluating their therapeutic effect and clinical feasibility. At present, fluorescence resonance energy transfer (FRET) technology has been widely used in real-time monitoring of aggregation, dissociation and distribution of polymer micelles (in vitro and in vivo). In this review, the polymer micelles, characteristics of FRET technology, structure and properties of the FRET-polymer micelles are briefly introduced. Then, methods and mechanism for combinations of several commonly used fluorescent probes into polymer micelles structures, and progresses on the stability and distribution studies of FRET-polymer micelles (in vitro and in vivo) as drug carriers are reviewed, and current challenges of FRET technology and future directions are discussed.
Objective To observe the clinical features of acute retinal necrosis syndrome (ARN).Methods The clinical data of 84 patients (98 eyes) with ARN were retrospective analyzed. The patietns had undergone the examinations of best visual acuity, intraocular pressure, Bscanning, slitlamp biomicroscope, preset lens, direct and (or) indirect ophthalmolscope,and trihedral reflector; fundus fluorecein angiography had been performed on the patients with clear refracting media. Some of the patients had undergone polymerase chain reaction (PCR) to dectet the types of the causative virus.Medication,laser photocoagulation,and vitreous surgery had been performed on the patients after the diagnosis was confirmed. The visual acuity and the change of ocular fundus had been followed up; the average followup was 24.1 months. Results The average age of the patients at the onset was 42.8 years with the bilateraleye rate of 16.6% and retinaldetachment rate of 57.1%. There were 53.5% and 35.5% patients had the final visual acuity of gt;0.02 after 6 and 12 months, respectively. Better prognosis was found in patients diagnosed within 2 weeks and second involved eye. Varicella zoster virus DNA was identified in 15 patients and herpes simplex virus 1 was found in 3.Conclusions ARN is an acute disease with high incidence of retinal detachment.Serious retinal vasculopathy always happens at the late stage, and the prognosis is poor. Diagnosis in early stage is important and application of PCR will do contribution to the right diagnosis.
Objective To evaluate the potential of specific mRNA marker keratin 19(K19) to detect micrometastasis by reverse transcriptase polymerase chain reaction (RT-PCR) .Methods One hundred and ninty four regional lymph nodes harvested from 6 cases of benign diseases, 4 cases of breast carcinoma, 5 cases of gastric carcinoma and 12 cases of colorectal carcinoma patients were examined by conventional pathology and amplifying tissue specific K19 mRNA by RT-PCR separately, then the two methods were compared with each other. Results None of the 34 lymph nodes which were pathological metastasis-negative from benign diseases expressed K19 mRNA by RT-PCR, all of the 28 regional lymph nodes which were pathological metastasis-positive from malignant cases showed trains of K19 mRNA by RT-PCR. Of the 132 lymph nodes which were pathological metastasis-negative from malignant cases, 11 lymph nodes were detected with micrometastasis by genetic diagnosis.Conclusion Genetic diagnosis of lymph node micrometastasis is more sensitive than conventional pathology and has diagnostic value and merits further study.