Biomedical subjects

Shuzhong Guo

Publications and source records attributed to Shuzhong Guo.

13 recordsLinked to original sources

PubMed2006

Transplantation of endothelial progenitor cells transferred by vascular endothelial growth factor gene for vascular regeneration of ischemic flaps.

BACKGROUND: Neovascularization occurs through two mechanisms: angiogenesis and vasculogenesis. Therefore, there are two strategies to promote neovascularization: therapeutic angiogenesis and therapeutic vasculogenesis (endothelial progenitor cells therapy). MATERIALS AND METHODS: In this study, we examined whether or not endothelial progenitor cells combined with vascular endothelial growth factor (VEGF) gene therapy is useful for ischemia surgical flaps in vivo. At the same time, we quantitatively compared the neovascularization ability of transplanted endothelial progenitor cells (EPCs) transducted with VEGF165 gene and EPCs alone. EPCs were isolated from cord blood of healthy human volunteers, cultured in vitro for 7 days and identified by immunofluorescence. After transduced with VEGF165 gene in vitro, proliferative activity of EPCs was assessed using MTT assay. CM-DiI was used to trace EPCs in vivo 4 days after injection of 5 x 10(5) VEGF-transduced EPCs(VEGF-transduced EPCs group, n = 10), 5 x 10(5) EPCs (non-transduced EPCs group, n = 10) in 500 microL EBM-2 media, or 500 microL EBM-2 media (EBM-2 media group, n = 10) local, a cranially based flap was elevated on the back of nude mice. The percent flap survival, neovasculariztion and blood flow recovery of flaps was detected. RESULTS: EPCs expressed cell markers CD34, KDR, and CD133. A statistically significant increase in percent flap survival was observed in mice of VEGF-transduced EPCs group as compared with that of non-transduced EPCs group: 67.99 +/- 6.64% versus 59.43 +/- 4.69% (P < 0.01), and 41.24 +/- 2.44% in EBM-2 media group (P < 0.01). The capillary density and blood flow recovery of flaps in VEGF-transduced EPCs group were both improved. CM-DiI-labeled VEGF-transduced EPCs were observed in vivo and the numbers of cells increased. CONCLUSION: EPCs from human cord blood can increased neovascularization of ischemic flaps and augmented the survival areas, and VEGF-transduced EPCs have more powerful ability of promoting neovascularization in animal model of ischemic flaps.

Animals↗

PubMed2006

The role of bifidobacteria in gut barrier function after thermal injury in rats.

BACKGROUND: Early multiple organ dysfunction syndrome appears to be facilitated with bacterial translocation in severe burn injury, yet the mechanisms of bacterial translocation remain in dispute. The aim of this study was to characterize the potential role of intestinal bifidobacteria in the pathogenesis of gut-derived bacterial translocation after burns and to analyze the effects of bifidobacterial supplement on gut barrier function. METHODS: Wistar rats were randomly divided into burn group (Burn, n = 60), sham burn group (SB, n = 10) in experiment 1, and burn + saline group (BS, n = 30), burn + bifidobacteria group (BB, n = 30), and sham-burn + saline group (SS, n = 30) in experiment 2. Animals in BB group were fed bifidobacterial preparation (5 x 10(9) CFU/mL) after burns, 1.5 mL, twice daily. Animals in BS and SS were fed saline. Samples were taken on postburn days 1, 3, and 5. The incidence of bacterial translocation and counts of Bifidobacterium, fungi and Escherichia coli in gut mucosa, as well as the sIgA levels in mucus of the small intestine were determined. The positive sIgA expression in lamina propria and ileum mucosal injury were evaluated light microscopically by blinded examiners. RESULTS: The incidence of bacterial translocation was increased after burns, which was accompanied by significant decrease in number of bifidobacteria but significant increase in E. coli and fungi in gut mucosa, and elevation of levels of plasma endotoxin and IL-6 (p < 0.001). The incidence of bacterial translocation was markedly reduced after 3- and 5-day supplementation of bifidobacteria compared with control group (p < 0.05). The counts of mucosal bifidobacteria were increased by 4- to 40-fold, whereas E. coli and fungi were decreased by 2- to 30-fold and 10- to 150-fold, respectively, after bifidobacterial supplementation. The damage of mucosa tended to be less pronounced after 3-day bifidobacteria-supplemented formula compared with control group (grade 2 [0-6] versus grade 4 [3-6], p < 0.05). Moreover, the expression and release of sIgA was markedly augmented after 3-days of bifidobacteria-supplementation formula and it returned to normal range on postburn day 5. CONCLUSIONS: The decrease in counts and proportion of bifidobacteria to other flora in gut may play an important role in the development of bacterial translocation after thermal injury. Supplementation of exogenous bifidobacteria could improve gut barrier function, and attenuate bacterial/endotoxin translocation secondary to major burns.

Animal Feed↗

PubMed2006

Enhancement of viability of fat grafts in nude mice by endothelial progenitor cells.

BACKGROUND: A recent discovery showed that endothelial progenitor cells (EPCs) could augment collateral vessel growth to ischemic tissues. OBJECTIVE: The objective was to demonstrate the effects of EPCs on the vasculogenesis and survival of free transplanted fat tissues in nude mice. METHODS: EPCs from human donors were cultured in vitro for 7 days. Human fat tissues were injected subcutaneously into the scalps of 20 6-week-old nude male mice. EPCs stained with CM-DiI were mixed with the transplanted fat tissues and injected into the mice. EBM-2 medium was used as control group. The animals were euthanized 15 weeks after the procedure. Graft volume were measured, and histologic evaluation was performed. The central part of fat tissues was histologically evaluated 15 weeks after the fat injection. RESULTS: The survival volume of the experimental group was significantly greater than that of the control group (p< .05). Less cyst formation and fibrosis was obtained in the experimental group. Histologic evaluation of the central part of fat tissues 15 weeks after the fat injection showed that capillary densities increased markedly in the experimental group mice. CONCLUSION: The results indicate that EPCs have the ability to enhance the survival and the quality of the transplanted fat tissues.

Adipose Tissue↗

PubMed2006

Mechanisms of dexamethasone to protect flaps from an ischemia-reperfusion injury.

OBJECTIVE: To study the effect of dexamethasone to protect flaps from an ischemia-reperfusion injury and elucidate its mechanism of regulating the death course of the neutrophils. METHODS: The rats were randomly divided into 3 groups. The vein of the rat was clamped for 8 h after the flap had formed. Group A: the normal flap; Group B: the saline control flap; Group C: the treatment flap with dexamethasone. The survival area of the flaps was measured at 7 days; the apoptotic and necrotic neutrophils, tumor necrosis factor alpha (TNF-alpha), and interleukin 10 (IL-10) concentrations were measured. RESULTS: The flap survival areas in Groups A and C were larger than those in Group B. The apoptotic neutrophils in Group B were fewer than those in Groups A and C on the 1st and 3rd days after operation; however, they were more in number in Group B than in groups A and C on the 6th day. The necrotic cells in Group B were more in number than those in Groups A and C. In Group B, the plasma TNF-alpha concentration reached the maximum level at 1 h, while the IL-10 level reached the lowest 3 h after the reperfusion. In Group C, the TNF-alpha concentration was lower than that in Group B and decreased dramatically at 6 h. The IL10 concentration was the lowest at 1 h, and increased rapidly at 3 h. Thus, ischemia-reperfusion could injure the flaps, probably through the abnormal action of the neutrophils, such as the disordered secretion of the cytokines and abnormal death course of the neutrophils. CONCLUSION: Dexamethasone can protect the flap from an ischemia-reperfusion injury by its regulation for the neutrophil function.

Animals↗

PubMed2004

Local hatchet flap for facial skin defects reconstruction in special areas.

BACKGROUND: The local hatchet flap has been used to reconstruct skin defects of the face with satisfactory results. Cosmetically, it has advantages over other local flaps when skin defects are located in special areas such as the eyelid. OBJECTIVE: The purpose of this study was to examine the application of local hatchet flaps for facial defect reconstruction, especially in cases where reconstruction is classically difficult for cosmetic and functional rehabilitation. METHODS: We report an illustrated case series. Results. In this study, all four cases achieved satisfactory functional and cosmetic results using the local hatchet flap. CONCLUSIONS: The local hatchet flap is an effective and simple alternative for reconstructing facial defects in special areas of the face, offering good cosmetic results and satisfactory function.

Adolescent↗

PubMed2002

[Rhinoplasty of unilateral cleft lip].

OBJECTIVE: To investigate the technique for unilateral cleft lip nasal deformities. METHODS: Through the traditional columella margin incision, the alar cartilage and the lateral nasal cartilage were exposed. After the mucosa between the two cartilages was divided, a mucosa-cartilage flap was developed and anchored, moving the lateral crus upwardly and medially, correcting the nasal deformity. RESULTS: 52 cases of primary nasal deformities and 18 cases of secondary nasal deformities were corrected with this technique. Satisfactory results were achieved. CONCLUSION: This technique is recommendable, which is more likely to restore the physiological characters of the nose than the conventional technique.

Adolescent↗

PubMed2002

[Investigation on contraction mechanism of expanded tissue].

OBJECTIVE: To investigate the contraction mechanism of expanded tissue. METHODS: White domestic pigs were employed to establish tissue expansion model. Tissue samples were taken after expansion for contraction measurements and histopathological observation. RESULTS: Dermis and capsule were the main positions of contraction. In the dermal layer, elastic fibers and myofibroblasts proliferated greatly and alpha-Actin enhanced in the myoepidermal cells and capillary endothelial cells during expansion. In the capsule, the direction of elastic and collagen fibers arranged crossly and formed into special contractible structure. CONCLUSION: Elastic fibers, myofibroblasts and alpha-Actin enhancement of cells were the substantial materials of tissue contracture increases. The results suggest that suitable tension must be applied into expanded flaps for anti-contraction.

Animals↗

PubMed2002

[Effects of conditioned medium derived from different keratinocytes on proliferation and collagen synthesis of hypertrophic scar fibroblasts].

OBJECTIVE: To observe the effects of supernatants of normal skin keratinocytes(NK) and scar keratinocytes(SK) on proliferation and collagen synthesis of hypertrophic scar fibroblasts(HSFB). METHODS: The supernatant, collected from cultured NK and SK, was added to the cultivated HSFB. The MTT-method, 3H-proline incorporation and radioimmunoassay were employed to measure the cell proliferation, collagen synthesis and secretion. RESULTS: NK supernatant could inhibit HSFB proliferation and increase the collagen synthesis, but inhibit collagen secretion, as compared with the control group. On the contrary, SK supernatant could increase collagen synthesis and secretion, which had little effects on HSFB proliferation. CONCLUSION: Keratinocytes derived from normal skin and hypertrophic scar show different effects on hypertrophic scar fibroblasts.

Cell Division↗

PubMed2002

[Computer-aided tissue expansion 3D profilometry and surgery planning system].

OBJECTIVE: To develop and evaluate the computer-aided system in measurement of expanded skin and preoperative planning. METHODS: Stereophotogrammetric technique was used to gain the 3D image-pairs, from which the contours of the expanded sites were restored. The 3D surface data were provided to the specially developed "computer-aided tissue expansion 3D profilometry and surgery planning system", to calculate the expansion area and help the preoperative design. RESULTS: The system has been applied clinically in 16 tissue expansion sites of 11 patients with fairly good results since March 1999. Compared with the traditional method, this system is accurate, repeatable and feasible. CONCLUSION: This technique is useful and promising for improving the operation of tissue expansion.

Adult↗

PubMed2002

[The influence of Matrine on apoptosis of fibroblasts and the expression of apoptotic modulation related protein in hypertrophic scar of rabbit ear].

OBJECTIVE: To investigate the effects of Matrine on apoptosis of fibroblasts and the expression of apoptotic modulation related protein in the hypertrophic scar. METHODS: Hypertrophic scar was produced on the ear of 24 New Zealand white rabbits, which were employed as the model, and were randomly and equally divided into control (CC) and Matrine (M) groups (12 in each group). Matrine (50 g/L) was injected into the ear scar in M group and with normal saline in C group once every four days. At 2, 4, 6, 8 and 12 weeks after the injection, the apoptotic fibroblast count in the scar was determined by TUNEL method, and the expressions of apoptosis related modulation proteins p53, bcl-2, bax were detected by immunohistochemistry method. RESULTS: The apoptotic fibroblast count was much larger in M group than that in C group at all test time points (P < 0.05). Furthermore, the bax expression was increased and that of p53 and bcl-2 was decreased significantly in M group. In adding, the scar became flat in M group. CONCLUSION: Matrine might obviously enhance the fibroblast apoptosis in rabbit ear hypertrophic scar, and up-regulate the expression of apoptosis related modulation protein bax and down-regulate the expression of p53 and Bcl-2.

Alkaloids↗

PubMed2002

[The expanded distant skin flap and its application].

OBJECTIVE: To summarize and present the experiences and results of the expanded distant skin flaps used in plastic and reconstructive operations. METHODS: 102 patients who had undergone expanded distant skin flap transfer were reviewed and followed up. RESULTS: Good results were obtained. Especially when there was no sufficient normal skin close to the lesion or defect, the distant skin flaps were employed. The expanded distant skin flap can be directly transferred as a pedicle skin flap or an island skin flap. It can be indirectly transferred with an intermediary carrier or as a free skin flap. CONCLUSION: The expanded distant skin flaps have many advantages, indications, worthy of recommendation.

Humans↗

PubMed2002

[Influence of endothelial cells on the proliferation of scar-derived fibroblast in hypertropic scar tissue].

OBJECTIVE: To investigate the influence of the endothelial cells on the scar-derived fibroblasts in the hypertropic scar tissue. METHODS: The endothelial cell from the human umbilical vein was cultured and its supernatant was then collected. Thereafter, it was mixed with the pre-cultured scar-derived fibroblasts from the hypertropic scar tissue. The fibroblasts were analyzed with a flow cytometer in a MTT-assay method to evaluate the cell proliferation and its division cycle. RESULTS: The endothelial cells were significantly increasing the scar-derived fibroblast proliferation (P < 0.05), compared with the control. The proportion of the fibroblasts in the S-stage of cell cycle was also quite high. CONCLUSION: The endothelial cells may secrete some active products, which may enhance the proliferation of the scar-derived fibroblasts and stimulate the fibroblasts into the S-stage of cell generation cycle.

Cell Cycle↗

PubMed2002

[Comparison of ultrastructural changes of skin between continuous tissue expansion and conventional tissue expansion].

OBJECTIVE: To observe the ultrastrual changes of the skin between the continuous tissue expansion and the conventional tissue expansion. METHODS: Twelve white piglets were used for this study on an animal model of tissue expansion with the continuous tissue expansion group and the conventional tissue expansion group. The tissue samples in each group were harvested and prepared for the transmission electron microscope observation. RESULTS: The interspace among basal cells and spinose cells was increasing and the numbers of cell conjunctures were decreasing in the both groups. However, these changes in the continuous tissue expansion group were more obvious than in the conventional tissue expansion group. In the dermal layer of the skin, the ultrastructure of collagen fibers were basically normal. But, the fibroblasts and capillary endothelia cells were more activated in the continuous tissue expansion group, compared with the conventional tissue expansion group. The fibroblast apoptosis and collagenolysis spots were observed in both of the groups, while the red blood cells were also found in the tissue leaked outsides from the blood vascular cavities. CONCLUSION: Tissue expansion may result in tissue growth and tissue degeneration in the same time.

Animals↗