Biomedical subjects

Feng Cheng

Publications and source records attributed to Feng Cheng.

28 records · Page 2Linked to original sources

PubMed2003

[Some principal surgical techniques for living donor liver transplantation].

OBJECTIVE: To investigate some principal surgical techniques of living donor liver transplantation (LDLT). METHODS: Eleven patients of LDLT have been performed at our department from January 2001 to March 2002. The left lobe (segments II, III, IV, including the middle hepatic veins) was transplanted in 8 patients, the left lateral lobe (segments II, III) in one and the right lobe (segments V, VI, VII, VIII, not including the middle hepatic veins) in 2. The plane of liver resection was determined on the basis of donor liver volumetry using CT scan and the anatomic analysis of vascular structure of the hepatic vein, portal vein and hepatic artery using intraoperative ultrasound. The hepatic parenchyma was transected using ultrasound aspirator without blood vessel clamping or graft manipulation. The isolated graft was perfused in situ through the portal vein branch. The liver graft was transplanted into the recipients who underwent total hepatectomy with preservation of the inferior vena cava. The hepatic vein reconstruction was performed in end to end fashion or end to side to the vena cava after venoplasty. Arterial anastomoses were performed using microsurgical technique. Biliary reconstruction was made by using duct-to-duct anastomosis and placement of a T tube. RESULTS: All the 11 donors are uneventfully discharged after operation. In the 11 recipients, an 8-year-old girl needed retransplantation because of hepatic artery thrombosis, one case died of serious chronic rejection on the postoperative day 72. Ten recipients recovered and were discharged from hospital, whose liver function and cuprum oxidase had returned to normal. CONCLUSIONS: The procedure of LDLT is relatively safe for the donor. Reconstruction of vessels is a key step in the procedure. Comprehending anatomical variation of vessels pre- and intra-operatively and correct surgical management might reduce the incidence of complications.

Adolescent↗

PubMed2003

[Relationship between the expression of IL-10 and liver regeneration following reduced-size orthotopic liver transplantation in rats].

OBJECTIVES: To explore the relationship between the expression of IL-10 and liver regeneration following reduced-size orthotopic liver transplantation in rats. METHODS: Rats models with reduced-size orthotopic liver transplantation were established. The rats were divided in three groups: partial liver resection (I), orthotopic liver transplantations (II), and reduced-size orthotopic liver transplantation (III). The expression of IL-10 and regenerative response of liver in rats were evaluated by immunohistochemistry and flow cytometry on the 1st, 2nd, 4th and 7th days after the operations, respectively. RESULTS: The liver grafts were capable of regeneration, the proliferation activity peaked on the fourth day with 26.3+/-0.9, 35.8+/-2.2, and 32.4+/-1.8 in I, II, and III groups, respectively. The expression of IL-10 was negative correlation to liver regeneration (r=-0.58, P<0.01). CONCLUSIONS: Whole and reduced-size transplanted livers show the same regenerative activity. The maximal regenerative response delayes slightly, compared with that after partial hepatectomy. IL-10 plays an important immunomodulatory role in liver regeneration,and the effect is affected by general immune system and other cytokines.

Animals↗

PubMed2003

[A study on the estimation of the size of male homosexual population].

OBJECTIVE: To study the practical survey method on estimating the size of male homosexual population. METHODS: Nine male homosexual gathering spots were selected and three methods as division method, capture-mark-recapture method and multiplier method were applied in counting the numbers of homosexual men in one city in Sichuan province. RESULTS: Number of counting through division method was 877 and the three numbers through capture-mark-recapture method were 1408, 1207 and 949 respectively. However, appropriate data was not obtained by multiplier method. CONCLUSIONS: Division method was easy to operate with its high credibility, but costly. Capture-mark-recapture method was less costly less both in capital and time, and the results could be testified to each other. Multiplier method should be modified before applied to obtain reliable information.

China↗

PubMed2002

[A clinical report of 12 case-times of living related liver transplantation].

OBJECTIVE: To evaluate and summarize the clinical application of living related liver transplantation (LRLT). METHODS: A retrospective analysis was made in altogether 12 LRLT operations of living related liver transplantation performed in our department. The indication and timing, surgical complications, and nonsurgical issues including infection, rejection, advantages of LRLT in our series were reviewed. RESULT: All the 11 donors are uneventfully after operation; the first receptor was dead, and 10 receptors with Wilson's disease achieve long-term survival. The postoperative survival time till now is 58 w, 51 w, 48 w, 38 w, 37 w, 36 w, 22 w, 18 w, 10 w and 7 w, respectively. No rejection was detected in the recipients with Wilson's disease, whose liver function and cuprum oxidase level had returned to normal. In this 10 cases, 6 of them has returned or gone to school, 2 of them were discharged from hospital, 2 of them has been recovered smoothly in the hospital due to short time postoperatively. The primary complications after operation including blood vessel, biliary tract, lung and the infection of microbe or virus, were mainly involved in our series. CONCLUSION: The process of operation was complicated; the operation technology was exigent and difficult with respect to the safety of the donors and receptors. LRLT has capacious clinical application for there are many unsurpassable advantages, such as plentiful resource and fine quality of graft liver, lower cost of LRLT.

Adolescent↗

PubMed2002

Steered molecular dynamics simulations on the "tail helix latch" hypothesis in the gelsolin activation process.

The molecular basis of the "tail helix latch" hypothesis in the gelsolin activation process has been studied by using the steered molecular dynamics simulations. In the present nanosecond scale simulations, the tail helix of gelsolin was pulled away from the S2 binding surface, and the required forces were calculated, from which the properties of binding between the tail helix and S2 domain and their dynamic unbinding processes were obtained. The force profile provides a detailed rupture mechanism that includes six major unbinding steps. In particular, the hydrogen bonds formed between Arg-207 and Asp-744 and between Arg-221 and Leu-753 are of the most important interaction pairs. The two hydrogen bond "clamps" stabilize the complex. The subsequent simulation on Arg-207-Ala (R207A) mutation of gelsolin indicated that this mutation facilitates the unbinding of the tail helix and that the contribution of the hydrogen bond between Arg-207 and Asp-744 to the binding is more than 50%, which offers a new clue for further mutagenesis study on the activation mechanism of gelsolin. Surrounding water molecules enhance the stability of the tail helix and facilitate the rupture process. Additionally, temperature also has a significant effect on the conformation of the arginine and arginine-related interactions, which revealed the molecular basis of the temperature dependence in gelsolin activation.

Arginine↗

PubMed2002

Structure-based 3-D-QSAR analysis of marine indole alkaloids.

A 3-D-QSAR study has been performed on these indole alkaloid derivatives to correlate their chemical structures with their observed antitumor activity against IGROV1. Due to the absence of information on their active mechanism, comparative molecular field analysis (CoMFA) has been applied. A model able to well correlate the antitumor activity with the chemical structures of mono and bis(indole) alkaloids 1-18 has been developed which is potentially helpful in the design of novel and more potent antitumor agents.

Alkaloids↗

PubMed2002

Molecular docking and 3-D-QSAR studies on the possible antimalarial mechanism of artemisinin analogues.

Artemisinin (Qinghaosu) is a natural constituent found in Artemisia annua L, which is an effective drug against chloroquine-resistant Plasmodium falciparum strains and cerebral malaria. The antimalarial activities of artemisinin and its analogues appear to be mediated by the interactions of the drugs with hemin. In order to understand the antimalarial mechanism and the relationship between the physicochemical properties and the antimalarial activities of artemisinin analogues, we performed molecular docking simulations to probe the interactions of these analogues with hemin, and then performed three-dimensional quantitative structure-activity relationship (3-D-QSAR) studies on the basis of the docking models employing comparative molecular force fields analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA). Molecular docking simulations generated probable 'bioactive' conformations of artemisinin analogues and provided a new insight into the antimalarial mechanism. The subsequent partial least squares (PLS) analysis indicates that the calculate binding energies correlate well with the experimental activity values. The CoMFA and CoMSIA models based on the bioactive conformations proved to have good predictive ability and in turn match well with the docking result, which further testified the reliability of the docking model. Combining these results, that is molecular docking and 3-D-QSAR, together, the binding model and activity of new synthesized artemisinin derivatives were well explained.

Antimalarials↗

PubMed2002

Investigation of the elemental distribution in iliac crests of female New Zealand rabbits using NAA.

This article deals with an osteoporosis model using New Zealand rabbits in order to study the function of inorganic elements for women patients with osteoporosis. Thirty cases of iliac crests were collected and determined using the neutron activation analysis technique. The results show that the fluorine concentrations in the experimental group are higher than those in the control group and that the magnesium concentrations are significantly lower (p < 0.001), but the concentrations of potassium, sodium, calcium, barium, manganese, and strontium show no significant differences. Combined with the serum biochemical markers of bone formation and resorption, the physiological functions of some metal elements in bone are also discussed.

Acid Phosphatase↗

PubMed2002

[Application of microsurgical technique to hepatic artery reconstruction in liver transplantation].

OBJECTIVE: To explore the value of the microsurgical technique in the reconstruction of hepatic artery. METHODS: From September 2000 to June 2001, we performed liver transplantation for 11 patients including living related liver transplantation (4) and 7 orthotopic liver transplantation (7). Arterial reconstruction was performed under an operating microscope. RESULTS: No patients developed hepatic arterial thrombosis and serious complication, nor death for multiple organ failure. CONCLUSION: Microsurgical technique in reconstruction of the hepatic artery can improve surgical outcome, not only in orthotopic liver transplantation but also in living related liver transplantation.

Adolescent↗

PubMed2000

In situ localization of procollagen gene expression on cryosections of undecalcified fracture callus.

OBJECTIVE: To analyze the expression of procollagen gene in fracture callus, and to search for the technique of in situ hybridization for undecalcified skeletal tissue. METHODS: In situ hybridization of procollagen gene expression was performed on the undecalcified cryosections of rat fracture callus at 7, 14, and 28 d. RESULTS: The hybridization signals achieved were clear and easy to be localized with high specificity. On the 7th day, the expressions of pro alpha1 (III) in fibroblasts and some chondrocyte-like cells were dominant; and at the end of second week high expression of type-II procollagen mRNA was observed in chondrocytes. At the end of fourth week, the cartilaginous callus was almost all replaced by woven bone tissue, and some type-I procollagen mRNA positive osteoblasts and hypertrophic chondrocytes were found scattering in the woven bone and remnants of cartilaginous callus. CONCLUSIONS: The modified method employed in this study is easier, quicker, and more sensitive with high specificity than the conventional tec hnique for in situ hybridization of procollagen gene expression of decalcified rat fracture callus. The phenomenon of shared phenotype expression, which was demonstrated among cells engaged in fracture healing, indicates an important approach to reveal the mechanism of the origin, differentiation, and orientation of cells.

Journal Article↗