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Objective To analyze the polymorphism of Plasmodium lactate dehydrogenase (pLDH) gene and predict B-cell epitopes in pLDH peptides in four species of human malaria parasites. Methods The blood samples and epidemiological characteristics were collected from malaria cases in Yunnan Province registered in the National Notifiable Disease Report System. The pLDH genes of four human Plasmodium species were amplified using nested PCR assay and sequenced. The polymorphisms of pLDH genes was analyzed using the software MEGA version 7.0.26 and DnaSP version 5.10, and the B-cell epitopes were predicted in pLDH peptides using the Immune Epitope Database (IEDB). Results The sequences of P. vivax LDH (PvLDH), P. falciparum LDH (PfLDH), P. ovale LDH (PoLDH) and P. malariae LDH (PmLDH) genes were obtained from 153, 29, 17 and 11 blood samples from patients with P. vivax, P. falciparum, P. ovale and P. malariae malaria, respectively, which included 15, 2, 4 and 2 haplotypes and had a nucleotide diversity (π) of 0.104. A high level of intra-species differentiation was seen in the PoLDH gene (π = 0.012), and the π values were all < 0.001 for PvLDH, PfLDH and PmLDH genes. Active regions of B-cell antigen were predicted in the pLDH peptide chain of four human malaria parasites, of 4 to 5 in each chain, and the activity score was approximately 0.430. Among these peptide chains, the “86-PGKSDKEWNRD-96” short-peptide was a B-cell epitope shared by all four species of human malaria parasites, and the “266-GQYGHS (T)-271” short-peptide was present in PvLDH and PoLDH peptide chains, while “212-EEVEGIFDR-220” was only found in the PvLDH peptide chain, and “208-LISDAE-213” was only seen in the PfLDH peptide chain. Conclusions The PoLDH gene polymorphism may be derived from the weak negative purification selection, while PvLDH, PfLDH and PmLDH genes may maintain a relatively conservative state. There may be two B-cell epitopes “212-EEVEGIFDR-220” and “208-LISDAE-213” in the proximal region of the C terminal in the pLDH peptide chain, which is feasible to differentiate between P. vivax and P. falciparum infections.
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AIM: To explore the characteristic of relaxation of porcine cornea after LASIKMETHODS: Usual LASIK was performed on fresh porcine corneas with stable intraoculer pressure (IOP) maintained through optic nerve irrigation. The ablation depth on stroma is 30%, 50% and 70% respectively. Then the dumbbell-shaped corneal strip specimens were cut and stored in 20% Human Albumin solution for use (4℃).Sip up the Albumin solution on specimens, and fixed them on homemade jig. Stress relaxation tests were erformed on Tytron250 Dynamics Experiment System. the loading speed was 385mm/min,extending ratewas 1.5, and relaxation time was 1 000s. The data werecollected electronically and automatically.RESULTS: In LASIK procedure, though a single flap-cutting can cause a little reduction of corneal stress relaxation (P＜0.05,P=0.49), the cornea may still remain its property of visco-elasticity. When ablation depth was 30% or more, corneal stress relaxation decreased to almost one half (P＜0.01).The change of corneal stress relaxation degree in vertical meridian specimen was lower than that in horizontal specimen, especially when ablation depth was 70%, and it's statistically significant (P＜0.001). In LASIK operation, the more depth the ablation, the more reduce the stress relaxation degree, and it's easy to cause deformation and creep deformation.CONCLUSION: The changes of the stress relaxation in verticai and longitudinal meridian specimens are similar, and slightly obvious in longitudinal specimen, especially in 70%ablation group.
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AIM: (1) To investigate the effect of amniotic membrane transplantation (AMT) on rabbit conjunctival surface reconstruction with severe alkali burns. (2) To evaluate the possibility of AMT treatment for ocular alkali burns during recovering stage.METHODS: Animal models were established on 30 eyes of rabbits by creating severe alkali burns on the conjunctiva from the upper corneal limbus to the upper conjunctival fornix.Preserved human amniotic membrane transplantations and reconstruction of conjunctival fornix were performed at one week after injury (recovering stage). Epithelium growth of burned area after transplantation was observed using light microscope at 1, 2, 3, 4, and 8 weeks. Conjunctival tissue in transplantation area was collected at 1, 4 and 8 weeks. The ultrastructure of the collected tissue was studied by electron microscope. The results were compared with control group,which received only vitamin C subconjunctival injection and antibiotic eye drops as treatment for alkali burn. Exterior eye pictures were also taken at the end of the observation, the width from upper corneal limbus to the edge of upper fornix was measured. Data was analyzed statistically.RESULTS: 1) Tn the transplant group, conjunctival epithelium growth was observed in the area of AMT under both light and electron microscope 1 week after surgery. At 4weeks, conjunctival epithelium with goblet cells that resembled normal conjunctival tissues was observed in the whole amniotic membrane area. At 12 weeks, the conjunctival epithelium on the amniotic membrane was well formed, and the connective tissue under the epithelium was loose at the fornix. No fibrosis was identified. In contrast, conjunctival epithelium necrosis was observed in the control group at 2weeks after alkali burns. Re-epithelization did not occur through the 12-week observation. Severe fibrosis with inflammatory cells infiltration was observed between 4 to 8weeks. At 12 weeks, fibrosis of the connective tissue at the fornix developed and there were no conjunctival epithelium covering the burned area. 2) In the transplant group, the conjunctiva in transplanted area had no scarring and appeared smooth at 12 weeks. Upper fornix was reconstructed. The depth of fornix was 7.9±0.3mm (7.6-8.2mm), which was approximate to the normal depth 8.2±0.2mm (8.0-8.4 mm,P＞.05). While in the control group, the burned area appeared rough with granuloma formation and severe scarring. Upper fornix became shallow. The depth of fornix was 3.1±1.7mm(1.0 to 4.5mm.), and significant difference was found between control and transplant group (P＜0.01).CONCLUSION: Human amniotic membrane preserved in glycerin can promote cell adhering, migrating and differentiating of normal conjunctival epithelium.Reconstruction of conjunctival surface in early stage of alkali burn can be achieved by AMT. AMT can effectively prevent symblepharon formation.
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<p><b>OBJECTIVE</b>To study the chemical constituents of Geranium eristemon.</p><p><b>METHOD</b>Chromatography and spectral analysis were used to isolate the constituents and elucidate their structures.</p><p><b>RESULT</b>Five compounds were isolated from acetone extract of the whole grass of G. eristemon, and identified as beta-sitosterol, protocatechuic acid, myricetin, kaempferol-7-O-alpha-L-arabifuranoside and kaempferol-3-O-alpha-L-arabifuranoside.</p><p><b>CONCLUSION</b>kaempferol-7-O-alpha-L-arabifuranoside and kaempferol-3-O-alpha-L-arabifuranoside were isolated from G. genus for the first time.</p>