Biomedical subjects

Ru-hua Zhang

Publications and source records attributed to Ru-hua Zhang.

4 recordsLinked to original sources

PubMed2006

[Study on genetic polymorphisms of CYP2F1 gene in Guangdong population of China].

OBJECTIVE: To investigate the genetic polymorphism of CYP2F1 gene, a member of CYP450 gene family in the healthy population and the patients with nasopharyngeal carcinoma (NPC) of Guangdong province, and furthermore analyze the relationship between CYP2F1 genetic polymorphism and the risk of developing NPC. METHODS: By direct gene sequencing, all of 10 exons of CYP2F1 gene were detected in 40 peripheral blood specimens of patients with primary NPC. For the genetic polymorphism with high allelic frequency, mismatch PCR-RFLP technique was developed to identify the different frequency between 368 NPC cases and 344 cancer-free controls. RESULTS: There were totally 35 SNPs identified in all of 10 exons and exon-intron junctions of CYP2F1 gene from 40 NPC patients, which included 10 missense mutations and 1 frame shift mutation. The most important mutation was C insertion located in 15-16 bp, which caused the frame shift. The allelic frequency of C insertion was 25%. However, there was no significant difference found between 368 NPC cases and 344 controls in allelic frequency of 15-16 bp C insertion mutation (P>0.05). CONCLUSION: A lot of genetic polymorphism of CYP2F1 gene is found in Guangdong population of China. However, no single genetic polymorphism associated with the individual susceptibility to NPC can be identified. The cooperated operations with multiple genetic polymorphisms of one or more genes may be critical factors contributing to the development and progression of NPC.

Asian People↗

PubMed2004

[Mutation and amplification of RIT1 gene in hepatocellular carcinoma].

OBJECTIVE: To explore the mutation and amplification of RIT1 gene and their correlation with carcinogenesis of hepatocellular carcinoma (HCC). METHODS: The polymerase chain reactioindirect sequencing method was used for detecting the mutations in the sequence of all 6 exons in the RIT1 gene of 50 HCC tissues and paratumor tissues. And the amplification of RIT1 gene was examined by fluorescence quantitative polymerase chain reaction method. RESULTS: A nucleotide 241 G --> C substitution in exon 5 of RIT1 gene was detected in one patient's HCC tissue, but not in paratumor tissue; this 241 G --> C substitution leads to Glu81Gln amino acid alteration in the conservative domain binding GTP. A nucleotide G --> C substitution in 5'-UTR (-21 bp from initial codon) was detected in all of the 50 HCC tissues and paratumor tissues, and 2- to 297-fold amplification of RIT1 gene was detected in 11 of 43 qualified cases, the amplification frequency being 25.6%. CONCLUSION: Gene amplification is one of the main activating ways of RIT1 gene in HCC, and its amplification might be correlated with HCC carcinogenesis, while point mutation might be not.

Adult↗

PubMed2002

[Studies on heart-protecting musk pH-dependent gradient-release pellets].

AIM: To prepare heart-protecting musk pH-dependent gradient-release pellets and investigate the drug release in vitro and in vivo. METHODS: The pH-dependent gradient-release pellet system was prepared by using HPMC, Eudragit L-30D-55 and Eudragit L100-Eudragit S100 (1:5) combinations as coater. The release of borneol and total ginsenoside from pH-dependent gradient-release pellets were determined according to the method of Pharmacopoeia of the People's Republic of China (2000) in the simulated gastrointestinal pH conditions. The gastrointestinal transit and disintegration of pellets was investigated by using gamma-scintigraphic trace in volunteers. The pharmacokinetics of borneol of heart-protecting musk pH-dependent gradient-release pellets was studied in 6 healthy volunteers by GC methods. RESULTS: The f2 value of release data of borneol and total ginsenoside of the heart-protecting musk pH-dependent gradient-release pellets was 79.6 in the simulated gastrointestinal pH conditions. The gamma-scintigraphic trace evaluation demonstrated that the pellets coated with HPMC, Eudragit L-30D-55 or Eudragit L100-Eudragit S100 (1:5) combinations can disintegrate in stomach, duodenum and jejunum or ileum. The gastrointestinal transit time of pellets was about 5 hours in fasted state and about 6 hours in fed state. The concentration-time curves of borneol of heart-protecting musk pills fit in two-compartment model. The pharmacokinetics data showed that borneol had a short time of absorption and elimination. The mean residence time (MRT) of borneol of heart-protecting musk pills was 2.61 hours. The plasma concentration of borneol of heart-protecting musk sustained-release capsule which consisted of three kinds of pellets coated with HPMC, Eudragit L-30D-55 or Eudragit L100-Eudragit S100 (1:5) combinations was steadier than those of heart-protecting musk pills, its Cmax was lower than and Tmax was near to those of heart-protecting musk pills, its MRT was 4.0 hours, and its relative bioavailability was 96%. CONCLUSION: The lipidsoluble borneol and watersoluble total ginsenoside of heart-protecting musk pH-dependent gradient-release pellets can release simultaneously while sustained-releasing in vitro. The heart-protecting musk pH-dependent gradient-release pellets had the characteristics of pH-dependent gradient-releasing and disintegration while transiting in gastrointestinal tract. A characteristic of gradient sustained-release was shown in the concentration-time curves of borneol of heart-protecting musk sustained-release capsule in volunteers.

Adult↗

PubMed2002

[Study on the preparation of venenum bufonis beta-cyclodextrin inclusion complexes].

OBJECTIVE: To study the preparation of Venenum Bufonis beta-cyclodextrin inclusion complexes. METHOD: An optimal condition was established by the uniform design. Under the optimal conditions the Venenum Bufonis beta-cyclodextrin inclusion complexes were prepared with 5 different methods. RESULT: The ball grinding method was superior to other four methods. The bufadienolide inclusion rate of Venenum Bufonis beta-cyclodextrin prepared with ball grinding method was 85.42%. CONCLUSION: Ball grinding method is the best method for the preparation of Venenum Bufonis beta-cyclodextrin inclusion complexes.

Amphibian Venoms↗