Amyloid fibrils belong to a category of abnormal aggregations of natural proteins, which are closely related to many human diseases. Recently, some critical peptide sequences have been extensively studied for clarifying the molecular mechanism of natural proteins to form amyloid fibrils. In the present study, we designed a short peptide GGAAVV (GAV-6) composed of hydrophobic amino acids glycine (G), alanine (A) and valine (V) and studied its ability to form amyloid fibrils. As characterized by atomic force microscopy (AFM) and dynamic light scattering (DLS), the peptide could self-assemble into smooth nanofibers without branches. Congo red staining/binding and thioflavin-T (ThT) binding experiments show that the nanofibers formed by GAV-6 shared identical properties with typical amyloid fibrils. These results show that the designed peptide GAV-6 could self-assemble into typical amyloid fibrils, which might make it a useful model molecule to clarify the mechanism for the formation of amyloid fibrils in the future.
Amino Acid Sequence ; Amyloid ; chemistry ; Humans ; Microscopy, Atomic Force ; Models, Molecular ; Nanofibers ; chemistry ; Peptides ; chemistry

Taxol is one of the most potent anti-cancer agents, which is extracted from the plants of Taxus species. Isopentenyl diphosphate isomerase (IPI) catalyzes the reversible transformation between IPP and DMAPP, both of which are the general 5-carbon precursors for taxol biosynthesis. In the present study, a new gene encoding IPI was cloned from Taxus media (namely TmIPI with the GenBank Accession Number KP970677) for the first time. The full-length cDNA of TmIPI was 1 232 bps encoding a polypeptide with 233 amino acids, in which the conserved domain Nudix was found. Bioinformatic analysis indicated that the sequence of TmIPI was highly similar to those of other plant IPI proteins, and the phylogenetic analysis showed that there were two clades of plant IPI proteins, including IPIs of angiosperm plants and IPIs of gymnosperm plants. TmIPI belonged to the clade of gymnosperm plant IPIs, and this was consistent with the fact that Taxus media is a plant species of gymnosperm. Southern blotting analysis demonstrated that there was a gene family of IPI in Taxus media. Finally, functional verification was applied to identify the function of TmIPI. The results showed that biosynthesis of β-carotenoid was enhanced by overexpressing TmIPI in the engineered E. coli strain, and this suggested that TmIPI might be a key gene involved in isoprenoid/terpenoid biosynthesis.

Objective To study deletion mutations and polymorphism of PINK1 gene exons in patients with Parkinson' s disease (PD) in the littoral of Zhejiang Province,and analyze the association between these changes and the etiology of PD.MethodsAll exons of PINK1 gene in 200 PD patients( 112early-onset PD and 88 late-onset PD) and 220 controls (68 young controls and 152 old controls ) were amplified by polymerase chain reaction (PCR). All the positive PCR products were sequenced,and genotypes were detected by dot blot allele and genotype frequencies of PINK1 were compared by the Chisquare test.ResultsNo deletion mutations of the exons were found in all patients and controls.However,a known heterozygote point mutation G12169A in exon 5 was identified in 2 patients with early-onset PD.And G12164A polymorphism and G12101A polymorphism were located on PINK1 gene of exon 5. There were G/G and G/A genotypes in G12164A polymorphism,no A/A genotype.There were G/A and A/A genotypes in G12101A polymorphism,no G/G genotype. The chain relation polymorphism A/A genotype frequency was significantly higher in the PD group 84/200 (42.0％ ) than the control group (52/220,23.6％,x2 =4.034,P =0.045 ).The frequency was also significantly higher in the late-onset PD (40/88,45.5％ ) than the old control (32/152,21.1％,x2 =3.951,P =0.047 ).There were no significant differences in alleles frequencies of other groups.ConclusionThe deletion mutation and point mutation are rare in PD patients in littoral of Zhejiang Province.Chain relation polymorphism at G12164A and G12101A in PINK1 gene might be a susceptible factor for PD patients.

Objective To evaluate the diagnosis value of urodynamics in patients with benign prostate hypertrophy(BPH).Method With urodynamic device,the full set of urodynamic exam was administrated in 427 patients with BPH,and the externalsphincter urethral myogram was monitored simultaneously in pressure-flow studies(PFS).The umdynamic finding such as Q_(max),P_(det)-Q_(max),DS(descending slope)and post-voiding residual(PVR)were recorded,as well as the situation of bladder detrusor constraction and bladder compliance and urethral sphincter coodination.The bladder outflow obstruction was diagnosed by A-G nomogram,P-Q plot and DS.The IPSS score and prostate volume were also acquired.Results The diagnostic rate of BOO is 81.5%,among them concomitantly detrusor muscle impair in 117 cases (27.4%),decreased bladder compliance in 162 case(37.9%),urethral sphincter dyssynergia in 148 cases(34.7%),and unstable bladder in 164 cases(38.4%).The increase degree of BOO show an increasing tendency with urodynamic finding such as Q_(max),P_(det)-Q_(max),P_(open),DS,IPSS score and prostatic volume respectively,but a decreasing tendency with Q_(max) and bladder compliance.Conclusions The urodynamic exam plays an important role in diagnosis of BOO.There is a positive relation among degree of BOO with urodynamic findings such as P_(det)-Q_(max),P_(open),DS and IPSS score and prostatic volume,however,a negative relation with Qmax and bladder compliance respectively.

DNA computer is a new research field which combines bot h the computer science and molecular biology. DNA computer is proposed to solve a class of hard problems of mathematical complexity by using a set of DNA sequen ces encoding all candidate solutions to the computational problem of interest an d find out the correct answers by serial manipulations of biochemical reactions. DNA computer is exactly a biomolecular computer which stores a vast quantity of information with high density. DNA computer, by means of its huge parallel comp utation and brute force search strategy, can solve the NP complete problems with polynomial time. The recent advances and principle of DNA computer are introduc ed. The future development and the bioinformatical significance of DNA computer are also analyzed and discussed.

Objective To investigate effects of emergent percutaneous coronary intervention(EPCI)on the prognosis of patients with cardiac arrest(CA)and cardiopulmonary resuscitation after acute myocardial infarction(AMI).Methods Thirty-two patients with CA and carcliopulmonary resuscitation after AMI were retrospectively reviewed and divided into EPCI group(n=12)and eonservative treatment group(n=20).EPCI was used during or after primary eardiopulmonary resuscitation in EPCI group but not in conservative treatment group.Mortality and occurrence rates of severe arrhythmia,of heart failure,of cardiac shock and of severe bleeding in hospital were compared between the two groups.Results The mortality in hospital was 17% in EPCI group and 70% in conservative treatment group,respectively(P＜0.001).Heart failure was developed in 3 patients from EPCI group and 16 patients from conservative treatment group,respectively(P＜0.01).There was no significant difference in severe arrhythmia,cardiac shock and severe bleeding between two groups(P＞0.05).Logistic regression showed that EPCI decreased mortality but the prolonged cardiopulmonary resuscitation(＞20 min)increased the mortality.Conclusion Early EPCI might improve the prognosis of patients with cardiac arrest and cardiopulmonary resuscitation after acute myocardial infarction.

Objective To express a recombinant protein TFPR1 ( the functional region of the snake venom proteins from Trimeresurus flavoviridis) in Pichia pastoris expression system. Methods The target gene was codon-optimized and synthesized according to the sequence of the conserved structural do-main of triflin and then cloned into the Pichia pastoris expression vector pPICZαA to construct the recombi-nant expression plasmid pPICZαA-TFPR1. The recombinant plasmid pPICZαA-TFPR1 was electroporated into the yeast strain X33. The transformed strains carrying expression plasmid were screened out with Zeocin and then induced by methanol to express the recombinant protein TFPR1. ELISA was performed for the screening of positive clones. SDS-PAGE and Western blot were used for further identification of the ex-pressed products. Results The recombinant plasmid pPICZαA-TFPR1 was successfully constructed. The recombinant protein TFPR1 was expressed in a secreted form at a molecular weight of 16×103. Conclusion The recombinant protein TFPR1 was successfully expressed in Pichia pastoris expression system, which laid a foundation for further researches on its biological function and application as an adjuvant.

OBJECTIVETo investigate the dynamic changes of type I collagen, and the activity of metalloproteinases-1 (MMP-1) and tissue inhibitor of metalloproteinases-1 (TIMP-1) after angioplasty.

METHODSThe restenotic model of iliac arteries of domestic microswine was established with hypercholesterol feed plus two angioplasties. Angioplastied vessels were harvested at the end of 1, 2, 3 and 6 months after the second angioplasty. Immunohistochemistry, transmission electronic microscopy and image quantitative analysis techniques were employed to study neointimal proliferation, the phenotype of vascular smooth muscle cells (VSMC) and the expression of type I collagen, MMP-1 and TIMP-1.

RESULTSThe peak of vascular neointimal proliferation was at 3 months after angioplasty. The expression of type I collagen gradually increased from 1 to 6 months after angioplasty. For MMP-1, expression was lower in the early stage after angioplasty but increase to normal levels of control vessels at 6 months after angioplasty. Expression of TIMP-1 rapidly increased in the early phase after angioplasty, reached peak at 3 months and maintained the high level till 6 months after angioplasty. Meanwhile, the VSMC was predominantly the synthetic phenotype at the early stage and was transformed to the contractive phenotype at the late stage after angioplasty. The ratio of TIMP-1 and MMP-1 was positively related to the area of the neointima and the expression of type I collagen respectively (P < 0.01).

CONCLUSIONType I collagen increased gradually after angioplasty, which might be determined by the ratio of TIMP-1/MMP-1 and also related to the phenotype of VSMC.

Angioplasty ; Animals ; Arterial Occlusive Diseases ; metabolism ; surgery ; Collagen Type I ; metabolism ; Iliac Artery ; surgery ; Matrix Metalloproteinase 1 ; metabolism ; Muscle, Smooth, Vascular ; cytology ; metabolism ; Swine, Miniature ; Tissue Inhibitor of Metalloproteinase-1 ; metabolism

Objective To investigate the clinical value of serum follicle stimulating hormone(FSH) and testicular volume in the etiology diagnosis of azoospermia.Methods The clinical data of 373 patients with azoospermia were analyzed retrospectively.The patients were divided into the group A,B and C according to their FSH detected level.The FSH level was normal in the group A,slightly increase in the group B and severe increase in the group C.The testicular volume and the spern retrieval success rate of each group were analyzed statistically.Results The testicular sperm retrieval success rates in the group A,B and C were 70.81％,22.22％ and 0 respectively;the average testicular volumes in the three groups were(11.39±5.06),(8.79±4.18),(6.96±4.12)mL respectively,the differences among the three groups were statistically significant(P＜0.05).Conclusion In the patients with azoospermia,the FSH level and testicular volume help to judge the testicular spermatogenic functional status and identify the type of azoospermia.

Objective To evaluate the short-term efficacy and safety of sevelamer hydrochloride in treating maintenance hemodialysis (MHD) patients with hyperphosphemia.Methods A multicenter,open-labeled,self-control study was performed.Phosphate binders were discontinued during a two-week washout period.Patients with more than 1.78 mmol/L serum phosphorus after two-week washout period were eligible for the trial.The dose was adjusted every two weeks as necessary to achieve serum phosphorus control. Sevelamer hydrochloride was administered to 138 MHD patients for 10 weeks and a second two-week washout period followed.Results A total of 111 from 138 patients fulfilled the whole 14-week study. Mean serum phosphorus and calcium-phosphate products starte to decline after two-week sevelamer hydrochloride treatment. By the end of 10-week sevelamer hydrochloride treatment, mean serum level of phosphorus [(1.85±0.50) vs (2.57±0.54) mmol/L,P＜0.01],calcium-phosphate product [(4.16± 1.72) vs (5.79 ± 1.50) mmol2/L2,P＜0.01 ] and low density lipoprotein [(1.64±0.76) vs (2.31 ±0.87) mmol/L,P＜0.01] were significantly decreased,while the adjusted serum level of calcium and serum intact parathyroid hormone kept steady.Both serum phosphorus and calcium-phosphrus product increased after the second washout period, but the levels were still lower as compared to pre-treatment [(2.26±0.71) vs (2.57±0.54) mmol/L; (5.12±1.63) vs (5.79±1.50) mmol2/L2,P＜0.01].Of the 138 patients involved,214 episodes in 106 patients and 121 episodes in 89 patients were reported as adverse events and adverse drug reaction respectively. Gastrointestinal symptoms,of which most were mild or moderate,happened to 68.1％ (94/138) patients. Conclusions Sevelamer hydrochloride can control serum phosphorus and reduce the levels of calcium-phosphorus product and cholesterol.Slight gastrointestinal symptoms like constipation are common during the treatment.