AIM: To synthesize biodegradable poly lactic acid (PLA) through the optimization and selection of process and catalyst.METHODS: This experiment was performed at the Research Center for Green Chemistry and Technology in the School of Municipal and Environmental Engineering of Harbin Institute of Technology from February 2003 to October 2004. Biodegradable poly L-lactic acid (PLLA) was synthesis by melt polycondensation using L-lactic acid (LA) as material. Firstly, oligo L-lactic acid (OLLA) was prepared by dehydrating aqueous solution of LA without catalyst. And then, the mixture of OLLA and catalyst was heated at a certain temperature and pressure for a period of time to get the product of PLLA. The structure of PLLA was characterized by Fourier transform infrared (FTIR) spectra and 1H- nuclear magnetic resonance (1H-NMR) spectra. The polydispersity was determined by gel permeation chromatography (GPC).RESULTS: OLLA with the viscosity average molecular weight (Mη) of 6 500 g/mol was prepared by the following steps: the solution of LA without catalyst was dehydrated at 140 ℃, first at reduced pressure of 30 kPa for 2 hours, and then at 5 kPa for 4 hours. SnCl2-p-toluenesulfonic acid (TSA) system was the effective catalyst for the polycondensation of OLLA. After the mixture of OLLA and catalysts polycondensed at 165 ℃ and 5 kPA for about 8 hours, PLLA with the Mη of 65 000 g/mol was obtained by using SnCl2-TSA system as catalyst with the SnCl2 amount of 0.4wt% to OLLA and equal mol ratio of SnCl2 and TSA.CONCLUSION:PLLA with a certain practicability was obtained under the optimal process and catalyst. Oligomerization of LA played an important role on improving the molecular weight of PLLA.

[Objective] To explore the mechanism of fever in damp- heat syndrome. [Methods] Hyperlipemia rabbit models were established by feeding fatty - sweet diet. After the injection of endotoxin, the secretion of tumor necrosis factor and interleukin 1 was observed in rabbit model (Group A) and compared with normal rabbits (Group B) . [ Results] The peak of tumor necrosis factor and interleukin 1 secretion was decreased and the decline was slow in Group A. [ Conclusion ] The damp - heat syndrome in seasonal febrile disease is not merely a simple addition of damp and heat, but a result of retention and interaction of the two factors.

Genomics ; Medicine, Chinese Traditional

Objective:To explore the cytogenetic characteristics of hypospadias in children by karyotype analysis.Methods:From June 2008 to May 2018, 45 children with hypospadias in Tianjin Children's Hospital had cytogenetic abnormalities. Their median age was 10 months(range 3 hours to 5 years old). Of the 45 cases, 20 were proximal hypospadias, 1 was middle hypospadias. All 24 cases had varying degrees of genitourinary malformations. Among them, 15 cases had unilateral or bilateral cryptorchidism, 5 cases had scrotal division, 3 cases had penile scrotal transposition, 3 cases had small penis, 3 cases had indirect inguinal hernia, 1 case had repeated urethra, 1 case had hydrocele and 1 case had concealed penis. To the other systemic malformations, there was 1 with cleft lip and palate and 1 with congenital heart disease. G-banding karyotype analysis of peripheral blood lymphocytes was performed in all 45 cases.Results:Among the 45 cases of hypospadias with abnormal karyotypes, with an abnormal rate of 14.0%, 28 cases (62.22%) had sex chromosome abnormalities, including (47, XXY), (46, XX/47, XXY), (45, X0/47, XYY), etc. Sexual inversion occurred in 8 cases (17.78%), all of which were 46, XX. There were 4 autosomal abnormalities (8.89%), including (46, XY, 9p+ ), (46, XY, 10p+ ) and (46, XY, 1q+ ). Chromosome polymorphism was found in 4 cases (8.89%), including [46, XY, inv(9)] and [46, XY, 16qh+ ], and the equilibrium translocation of 1 case (2.22%) was [45, XY, -21, -22, + t(21; 22)]. Among the 45 cases, 8 sex reversal children with (46, XX) chromosome karyotype were all proximal hypospadias.Conclusions:Children with hypospadias may be associated with chromosomal karyotype abnormalities, including sex chromosomal abnormalities, autosomal abnormalities, chromosome polymorphism and balanced translocation. Among them, sex chromosome abnormality was the most common and balanced translocation was the least.

Objective To analyze the prognostic factors and their influences on breast cancer patients with local-regional recurrence.Methods From Jan.1st,1998 to Dec.30th,2007,66 breast cancer patients with local-regional recurrence were treated at Breast Center of Peking University People's Hospital.The overall survival of the patients was analyzed using Kaplan Meier survival analysis and the prognostic factors such as primary tumor status,initial treatment,location of recurrence and treatment strategy after local recurrence were analyzed using Cox regression model.Results The median follow-up was 111 months.The median survival for the 66 patients with recurrence was 99 months,ranging from 3 to 188 months and 5-year survival rate was 60％.Kaplan-Meier analysis revealed statistically significant better survival for patients with unifocal primary tumor,undergoing initial breast conservation surgery,with local recurrence only and undergoing radical local treatment after local recurrence (P =0.003,P =0.017,P =0.050,and P =0.000 respectively).COX regression analysis showed that age at initial diagnosis and radical local treatment after recurrence had influences on post-recurrence survival of patients without distant metastasis (P =O.004 and 0.000 respectively).Conclusion The clinical and pathological features of primary tumor,initial surgery,site of recurrence and treatment strategy after recurrence have influences on prognosis of breast cancer patients with local-regional recurrence.

Although current synthetic anti-gout drugs have significant therapeutic effects in reducing serum uric acid levels, they have serious side effects such as allergic reactions and liver and kidney damage. Natural products with a wide range of uric acid-lowering and high safety have played a critical role in anti-gout drug discovery and development. This paper reviews the natural products with uric acid-lowering or anti-gout pharmacological effects and the investigation on their mechanisms of action, to provide information for drug discovery and development.

China University Subject Ranking (CUSR) and Essential Science Indicators (ESI) are important reference indicators for China medical discipline level. The main problems affected the development of medical discipline are the medical education mode failed to fit uniqueness of medical education, the limitations of the design of medical talent training, the low efficiency of medical clinical research ability and so on. Taking the construction of "top level" as the goal oriented and improving the medical discipline level, we need to grasp the following key links: to establish the medical education mode with respect to the special pattern of medical education, to build the medical talents highland with innovation course and incentive system, and to promote the development efficiency of medical discipline based on the standard management system and so on.

Objective To compare the efficacy and toxicity of different cycles of neo-adjuvant chemotherapy for locally advanced breast cancer. Methods Seventy-five patients with locally advanced breast cancer were treated with epirubicin (Epi) plus paclitaxel (TAX, ET regimen). Two cycles were used in 39 patients (2 cycles group) and 4 cycles were used in 36 patients (4 cycles group). Results The overall response rate (RR) was 74% (29/39) in 2 cycles group and 94% (34/36) in 4 cycles group. One patient got clinically complete response (CR), 28 cases had partial response (PR),10 with no change (NC) in 2 cycles group, while 21 patients showed CR including 11 patients with pathologically complete response, 13 with PR, and 2 with NC in 4 cycles group. There was no progression to advanced stage in either groups. Axillary lymph nodes were palpable in all 75 patients before ET regimen, lymph nodes became non-palpable in 46% (18/39) cases in 2 cycles group and in 75% (27/36) cases in 4 cycles group. Toxicities including leukopenia, gastroenteric reactions were similar in the 2 groups, though arthralgia, myalgia, and neurotoxicity were more common in 4 cycles group than 2 cycles group. Conclusion Neo-adjuvant chemotherapy with ET regimen for 4 cycles were more effective than 2 cycles to down staging locally advanced breast cancer. Toxicities including arthralgia, myalgia, and neurotoxicity were more common in 4 cycles group than 2 cycles group.

In 2013, the World Health Organization reported the first case of human infection with a new influenza A (H7N9) virus in China. This has caused damage and panic within certain areas in China. Therefore, analysis of this virus with bioinformatics technology is very necessary. Neuraminidase (NA) is one of the most important antigens of the influenza virus and an important target for anti-flu drugs. In this study, the nucleotide and protein sequences of NA gene of A/H7N9 influenza viruses were retrieved from the NCBI database, and MEGA 5.0 software was employed to construct a phylogenetic tree based on the nucleotide coding sequence; BioEdit software was used to align the nucleotide and protein sequences of NA and calculate the homologies of nucleotides and amino acids and then to analyze the important mutation sites of NA gene. The results demonstrated that the spread of influenza virus H7N9 showed certain geographical and temporal relations. The H7N9 virus isolated from China in 2013 belonged to Euroasiatic serotype, and its NA stalk region hadobvious variation, which may be one of the reasons that this virus infects human. These analyses may be very helpful for understanding the evolutionary relationship and mutation trend of A/H7N9 influenza viruses.
Databases, Genetic ; Evolution, Molecular ; Humans ; Influenza A Virus, H7N9 Subtype ; enzymology ; genetics ; Mutation ; Neuraminidase ; chemistry ; genetics ; Phylogeny ; Sequence Analysis

Objective To study the expressions of foliate binding protein 1(Folbp1),Wnt and ?-catenin genes on the heart of offspring during the development of embryo,whose mother was deficient of folic acid.Methods Control group involving 18 rats and study group involving 18 rats were choosen from the total 36 adult female SD rats randomly copulate with the male normal rats after feeding different fodder for 2 weeks.The heart of the 13.5,17.5 days embryos and the newborns were obtained.The expressions of Folbp1,Wnt and ?-catenin genes mRNA at the 3 periods were evaluated by RT-PCR.Results The expressions of Folbp1,Wnt and ?-catenin genes mRNA of the study group were significantly weaker than those of the control group in heart of the 13.5,17.5 days embryos and the newborns(all P