Biomedical subjects
Publications and source records attributed to Z Guo.
In this study we analysed the interactions between initial lymphatic and interstitium, examined the procedure of lymph formation, developed the interaction theory for lymph formation, and showed that not only interstitial fluid prssure but also normal stress of interstitial solid phase should be considered and that lymph flow rate is greatly affected by interstitial porosity.
In the immigrant settlement area of Three-Gorges reservoir region in Xingshan County, Hubei Province, the ecological problems were the restoration of degraded ecosystem, rehabilitation of degraded crop land, and reconstruction of towns and villages. The key to the construction of the settlement area was reassigning the way of land use. The major aim of restoration of natural ecosystems should be to improve water conservation capacity of the land, because this area is located in the catchment of the Xiangxi River. The goals of management were determined as the coordinated development of both agricultural and natural forest ecosystems, the maintenance and increase of water conservation capacity of ecosystems, and the maintenance and extension of wildlife habitats. For the purpose of effective ecosystem management, the area was classified into four divisions of functional conservation region, functional rehabilitation, natural reserves and natural maintenance. The ecosystem management of the settlement area in Xingshan County was implemented in every land cell, using GIS and the typical grid-square survey method. The approach of multi-objects optimal spatial plan was developed in this paper, in which, special emphasis was put on the ecological, economic and social benefits in the construction of towns and villages. According to the scheme of management, the cover of forest in the settlement area, would increase by 30.19%, and water conservation capacity of the ecosystems would raise by 38.7%.
OBJECTIVE: To evaluate the effect of recombinant bovine basic fibroblast growth factor (rbFGF) on accelerating healing of burn wounds, donor sites and chronic dermal ulcers in multicenters. METHODS: One thousand and twenty-four patients with burns, donor sites and chronic dermal ulcers were recruited for this prospective and multicenter clinical trial and another 641 patients with the similar wounds were used as controls. All patients were divided into three groups: burn group, donor site group, and chronic dermal ulcer group. In the burn group, 654 patients with superficial second-degree burns(superficial II degree) or deep second-degree burns(deep II degree) were treated topically with either recombinant bovine basic fibroblast growth factor (rbFGF plus vehicle, rbFGF 150 AU/cm2/day, 330 patients) or placebo (vehicle without rbFGF, 324 patients). In the donor site group, 509 patients were treated with rbFGF and 317 patients with placebo in a similar way as described elsewhere. In the chronic dermal ulcer group, 185 patients were treated with rbFGF and the controls were themselves. Photography, histological evaluation and clinical examination were used to evaluate the results of wound healing. RESULTS: All of superficial second-degree burns, deep second-degree burns and the donor sites treated with recombinant bovine basic fibroblast growth factor had an accelerated rate of granulation tissue formation and epidermal regeneration as compared with that in the controls. Superficial second-degree burns and deep second-degree burns treated with recombinant bovine basic fibroblast growth factor healed in 9.89 +/- 2.45 and 17.04 +/- 4.56 days, respectively, whereas the average healing time in those receiving placebo was 12.35 +/- 2.74 and 21.21 +/- 4.88 days. The donor sites treated with rbFGF or placebo healed in 10.68 +/- 4.55 and 14.74 +/- 6.46 days, respectively. All chronic dermal ulcers except 12 patients treated with rbFGF healed within 6 weeks. Histological evaluation of punch-biopsy specimens from the burn wounds, donor sites and chronic dermal ulcers seven days after treatment supported the impression of accelerated wound healing after rbFGF treatment. CONCLUSIONS: rbFGF is effective in shortening the wound healing time and improving the wound healing quality. Accelerating wound healing is of clinical benefit in reducing the length of hospitalization, costs and emotional burden of the patient.
OBJECTIVE: To identify the role of cytokines involved in the development of lung fibrosis in patients with idiopathic-pulmonary fibrosis (IPF). METHODS: Proteins and gene expression of platelet-derived growth factor (PDGF)-A and -B, insulin-like growth factor 1 (IGF-1), and transforming growth factor beta (TGF-beta) were measured in alveolar macrophages and open lung biopsies from patients with IPF using immunohistochemistry (IHC) and in situ hybridization (ISH). RESULTS: In specimens of bronchoalveolar lavage fluid (BALF), PDGF-A, PDGF-B, IGF-1, TGF-beta were localized in alveolar macrophages. Evaluation of open lung biopsies from patients with IPF showed that IGF-1 was prominently present in pulmonary vessel walls in fibrotic lesions. PDGF and TGF-beta proteins were localized to hyperplastic bronchio-alveolar epithelial cells, alveolar macrophages, fibroblasts, vascular smooth muscle and endothelial cells. Our in situ hybridization results were consistent with that of immunohistochemistry except that PDGF-A and TGF-beta mRNA transcripts were not detected in bronchoalveolar epithelial cells. CONCLUSION: These observations suggest that (1) alveolar macrophages play key roles not only in inflammation but also in the fibrotic process by releasing PDGF, IGF-1 and TGF-beta; (2) IGF-1 could be responsible for angiogenesis in IPF; (3) PDGF, TGF-beta are associated with fibroplasia and the deposition of extracellular matrix, as well as vessel remodeling and epithelial cell repopularization.
OBJECTIVE: To study the extent of lymph node involvement in relation to survival of patients with thoracic esophageal carcinoma. METHODS: From 1990 to 1993, there were 112 patients with thoracic esophageal carcinoma undergone esophagectomy through right thoracotomy and three-field lymphadenectomy. They were classified into three groups: group A, 44 patients without lymph node involvement; group B, 36 patients with 1 to 3 positive nodes; group C, 32 patients with > or = 4 involved lymph nodes. Nine possible factors influencing survival were studied. A multivariate analysis of these variables was performed using the cumulative survival rate by the computer's Cox proportional hazard model. RESULTS: The over-all cumulative survival rate was 58.4% at 5 years. That for patients in group A, B and C was 88.4%, 50.8% and 20.8%, respectively. Apart from the extent of lymph node metastases, depth of tumor invasion, location and differentiation of tumor were of prognostic significance. CONCLUSION: Lymph node metastasis is the major factor affecting survival of patients with cancer of the thoracic esophagus.
OBJECTIVE: To assess the synergetic change of thoracoabdominal motion in COPD patients during incremental exercise testing, and to evaluate the effect of oxygen therapy on thoracoabdominal synergetic motion. METHODS: 30 stable moderate to severe COPD patients performed incremental exercise test with ergometer twice while breathing either air or 30% oxygen. Thoracoabdominal motion (assessed by TCD/VT) was monitored with respigraph during the whole test. RESULTS: 18 of 30 patients had TCD/VT > 1.20 during maximal exercise. TCD/VT at maximal exercise (TCD/VTmax) was significantly correlated with FEV1, FVC, MVV and PaCO2(r = -0.66, -0.63, -0.51, and 0.51), but not correlated with DLCO. The thoracoabdominal synergetic motion could be obviously improved with oxygen therapy. CONCLUSIONS: The change of thoracoabdominal synergetic motion during exercise in COPD patients was related with ventilatory function and blood gases. Oxygen therapy could obviously ameliorate paradoxical thoracoabdominal motion.
OBJECTIVE: To determine if the preventive and treatment measures developed from basic and clinical research work have any effects on the incidence and outcome of MODS in severely burned patients. METHODS: 657 extensively burned patients (burn size exceeding 30% TBSA) admitted to the clinical department from January 1970 through October 1999 were studied. The morbidity and mortality rates were compared in patient groups hospitalized before and after January 1990 when major preventive and treatment measures began to be extensively executed. These measures consisted of prompt, rapid and adequate fluid resuscitation, restoration of bowel blood supply with anisodamine (654 - 2), use of oxygen free radical scavengers (e.g. mannitol, vitamin C and E), extensive escharectomy during shock stage, early tube feeding, support of organ function, etc. RESULTS: Before 1990 when very few preventive and treatment measures were applied, the incidence of MODS, 17.3% (64 out of 369), and the death rate 87.5% (56 out of 64). After 1990, with the application of various preventive measures and treatment, the morbidity and mortality rates were reduced to 6.9% (20/288) and 40.0% (8/20), respectively. CONCLUSION: Our results suggest that measures which mitigate or eliminate the predisposing and causative factors of MODS may be salutary in the prevention and treatment of MODS after extensive burn injury.
OBJECTIVE: To study the efficacy of surgical treatment in the patients with left main stenosis of 50% or more. METHODS: Forty-two patients with left main stenosis (LMS) underwent coronary artery bypass grafting (CABG). Their mean age was 68.7 years. 16 patients had 50% to 75% LMS and 26 patients more than 75%. Twenty-nine patients had unstable angina. Seventeen patients with angina were in class III according to CCSS and 18 were in class IV. Preoperative left ventricular ejection fraction in 24 patients was beyond 50%. RESULTS: The mean preoperative hospital stay was 2.3 days. The mean number of grafts was 3.3 per patient. There was no operative death. The patients were all free from angina postoperatively. The mean follow up time was 42 (3 to approximately 78) months without death. CONCLUSIONS: Coronary artery bypass grafting is the first choice to treat left main stenosis. It is a safe and effective method. To determine properly the time of surgical intervention is helpful to reduce preoperative cardiac affairs and improve operative efficacy.
OBJECTIVE: To observe the dynamic changes of the plasma ET-1 and the effect of low dose nitroglycerin in patients with coronary artery bypass surgery. METHODS: 40 patients with coronary artery bypass surgery were divided into group A and B. Group B received intravenous nitroglycerin 1 microg x kg(-1) x min(-1) perioperatively. We used RIA to assay the plasma ET-1 level. All the hemodynamic parameters were recorded by the Swan-Ganz catheter. RESULTS: The preoperative plasma ET-1 level in patients with coronary artery disease was significantly higher than the normal level. Five minutes after cardiopulmonary bypass in these patients the plasma ET-1 level was increased significantly until 6 to 8 hours after operation. The increased plasma ET-1 level in group B was less than in group A. There was a positive correlation between the plasma ET-1 level and the mean pulmonary pressure in group A 2 and 8 hours after operation. CONCLUSION: In patients undergoing coronary artery bypass surgery, the increased plasma ET-1 level may be partly due to the influence of cardiopulmonary bypass. Low dose of nitroglycerin is beneficial to these patients.
OBJECTIVE: To observe the preventive effect of anisodamine on possible sepsis of patients with major burns and the effect of anisodamine on patients with sepsis. METHODS: Forty-two patients with extensive burn admitted to our burn institute from April 1998 to November 1999 were divided randomly into two groups: treatment group (T group) and control group (C group). In the T group, all 20 patients received fluid resuscitation regimen with anisodamine, and in the C group, 22 patients received the regimen with no anisodamine. A tonometry catheter was positioned in the stomach, connecting with the automatic gas analysis machine (Datex-Engstrom Corporation, Dutch) for determining gastric intramucosal pH (pHi). The plasma concentrations of diamine oxidase (DAO) and endotoxin were measured. Correlation analysis between pHi, DAO and endotoxin were made respectively during early stage of postburn. All the parameters in 7 patients with sepsis before and after administration of anisodamine were compared with those in 6 patients with sepsis without use of anisodamine. RESULTS: The incidence of sepsis in the T group was lower (20.0%) than that in C group (40.9%). The gastric pHi value in the early period of postburn was significantly higher in the T group than in the C group (P < 0.05). Concurrently, the plasma concentrations of DAO and endotoxin were significantly lower in the T group than in the C group (P < 0.05 or 0.01). A significant negative correlation was seen between the gastric pHi and respective values of DAO, endotoxin (P < 0.05 or 0.01). There were a decrease in gastric pHi, and an increase in plasma DAO and endotoxin level in patients with septic episode; however all the parameters after administration of anisodamine were improved compared with those in septic patients without use of anisodamine. CONCLUSIONS: Intestinal ischemic injury plays an important role in provoking sepsis during early postburn period. Anisodamine is effective in restoring intestinal circulation both in the shock phase and after the development of sepsis.
OBJECTIVE: To observe the effect of acellular allogenic dermis or acellular porcine dermis together with split-thickness autologous skin graft on coverage of deep burn wound and the wound of scar excision. METHODS: Acellular allogenic dermis or acellular porcine dermis produced by our unit, with split-thickness autologous skin graft, were used in repairing various wounds in 119 cases. The take rate of various wounds was compared, and the take rate of wounds in which autologous skin from different sites was used to cover either acellular allogenic dermis or acellular porcine dermis was also compared. Histological examination and follow-up were made in some cases. RESULTS: After tangential excision, eschar excision and scar excision, the wounds were covered with either allogenic acellular dermis or porcine acellular dermis and autologous split-thickness skin. The take rate was found to be (93.4 +/- 3.4)%, (92.1 +/- 4.6)%, (94.5 +/- 3.5)%, respectively. There was no a significant difference in take rate (P > 0.05). No significant difference in take rate between the transplantation of allogenic acellular dermis with autologous split-thickness skin and transplantation of porcine acellular dermis with autologous split-thickness skin was found (P > 0.05). When autologous split-thickness skin harvested from the trunk or extremities was used, the take rate was (93.1 +/- 4.8)%, (89.0 +/- 6.2)%, respectively, whereas the take rate was only about 70% - 80% when skin harvested from the scalp was used. The take rate was only about 40% when acellular allogenic dermis and autologous micro-skin graft were used to cover the wound. Histological examination 19 months after the transplantation revealed normal structure. Collagenous fibers were orderly arranged. There was no apparent hyperplasia of collagenous fibers. Hair follicles, sweat glands and other skin appendages were not found in the healed area. Grossly, no obvious pigmentation was seen, the surface was smooth with slight wound contraction, and the consistency was flexible. CONCLUSION: Acellular allogenic split-thickness dermis or acellular porcine split-thickness dermis with autologous split-thickness dermis for coverage of deep burn wound and the wound of scar excision is an ideal material.
OBJECTIVE: To investigate the influence of solid thoracolumbar kyphosis on the lumbar spine and surgical treatment. METHODS: 14 had solid kyphosis of the thoracolumbar spine. Cobb angle of kyphosis of the thoracolumbar spine and lordosis between L(2)/S(1), L(2)/L(5), L(2)/L(3), L(3)/L(4), L(4)/L(5), L(5)/S(1) pre- and post-osteotomy was measured respectively, and the amount of vertebrae slipped over 3mm was recorded. The results were compared with those of the normal group respectively. RESULTS: The Cobb angles of lordosis between L(2)/S(1), L(2)/L(5), L(2)/L(3), L(3)/L(4), L(4)/L(5), L(5)/S(1) in the deformity group were increased significantly compared with those that of the normal group respectively; obvious changes in percentage occurred in the segment between L(2)/L(3) and L(3)/L(4). Over lordosis of the lumbar spine was greatly corrected postosteotomy of the thoracolumbar spine, it was still significantly different compared with that of the normal group. In 9 patients with retrolisthesis of 20 vertebrae, 70% occurred in L(2) and L(3) vertebrae. The amount of retrolisthesis of vertebrae decreased to 3 in two patients. No retrolisthesis of vertebra was seen in the normal group. Single-stage procedures combined with anterior releasing and posterior osteotomy through facet joints for kyphosis of the thoracolumbar spine showed a correction. rate of 85.7%, but single-stage osteotomy through the posterior vertebra showed a correction rate of 60.7%. Seven of 8 patients who had had seriously back pain complained of no pain or slight backache after operation. 40% of the patients showed functional improvement in the sphincter of the urinary bladder and anus. 50% of the patients had improvement in muscle strength. CONCLUSIONS: Kyphosis of the thoracolumbar spine may result in over lordosis of the lumbar spine and retrolisthesis of vertebrae, which are obvious in the upper lumbar spine. These changes may lead to back pain. Correction of kyphosis of the thoracolumbar spine may obviously decrease over lordosis of the lumbar spine and inclination of vertebral slip, and may further decrease the overload to the posterior column of the spine and relieve back pain. Osteotomy combined with anterior and posterior procedures is effective and safe in the correction of kyphosis of the thoracolumbar spine.
OBJECTIVE: To study the rules of postburn expression of IGAM-1 and TNF-alpha and the rule of the change in the MPO activity in pulmonary tissue; to explore the influence of escharectomy on the changes in the above indices and to clarify the importance of escharectomy during shock stage. METHODS: One hundred and seventy six Wistar rats with 30% TBSA III degree back scald were used. RT-PCR was used in the examination of the expression of pulmonary tissue ICAM-1 and TNF-alpha mRNA and of the change in pulmonary MPO activity after escharectomy. RESULTS: The expressions of pulmonary ICAM-1 and TNF-alpha mRNA began to increase at 4 hour postburn and reached peak level at 12 and 24 hours postburn, respectively. Their expressions returned to near control level 96 hours postburn in rats undergone escharectomy during shock stage. On the contrary, they remained at a relative high level even on 7th postburn day in both non-operated rats and the rats receiving escharectomy 96 hours postburn. In addition, pulmonary tissue MPO activity fell to near control level in rats undergone escharectomy during shock stage, but it maintained a high level in rats in which escharectomy was not done during shock stage. CONCLUSION: These findings suggest that eschar could induce the production of endothelial adhesion molecules. Therefore escharectomy as early as possible is very important to prevent the expression and release of adhesion molecules and the development of SIRS.
OBJECTIVE: To determine the changes in resting energy expenditure (REE) of minipigs in normal and postburn stage, and the effect of escharectomy during burn shock stage on energy expenditure. METHODS: Swine model with 35% TBSA III degree flame burn was used. Eighteen male minipigs were randomly divided into three groups: control group, escharectomy during burn shock stage group and escharectomy after burn shock stage group. REEs were monitored by means of Cardiorespiratory Diagnostic Systems (Medical Graphics Corporation, USA). RESULTS: The levels of REE in escharectomy during burn shock stage group decreased early and were obviously lower than those in other two groups. CONCLUSION: These findings suggest that escharectomy and skin grafting during burn shock stage could ameliorate hypermetabolism in major burn patients.
OBJECTIVE: To retrospectively sum up the experiences in the prevention and treatment of sepsis after thermal injury. METHODS: From January 1970 through October 1998, altogether 5 330 burn patients were admitted to our burn center, and among them 451 patients developed sepsis. To analyze the efficacy of different treatment strategies developed during these 29 years, three periods were divided, namely 1970 to 1979, 1980 to 1992, and 1993 to 1998. The incidence and mortality of sepsis were compared, thereupon the efficacy of different treatment strategies were analyzed. RESULTS: The overall incidence and mortality of sepsis in all patients and those in patients with burn extent exceeding 30% TBSA were significantly lower in the latter period compared with the former two periods (P < 0.05 similar 0.01). In addition, in the last period, blood levels of LPS, TNFalpha, IL -- 6, and IL -- 8 were obviously higher throughout the course of MODS, especially before death, in the patients who finally died of sepsis, complicated by MODS, compared with those in the survivors (P < 0.05 similar 0.01). CONCLUSION: Summing up our experiences, it is our belief that the treatment strategies for prevention of postburn sepsis in extensively burned patients should include rapid, adequate fluid resuscitation for burn shock, effective control of infection, early excision of deep burnwounds followed by good skin coverage, and reinforcement of organ support. Once burn wound sepsis occurs, prompt removal of infected necrotic tissue is the key procedure to ensure a successful result.
OBJECTIVE: To investigate the effects of zinc supplementation on postburn nutritional status of zinc-deficient scalded rats. METHODS: Weanling Wistar rats were fed with zinc-deficient diets for one week to induce zinc-deficient status. The rats were inflicted with 20% TBSA deep partial thickness burn and thereafter fed with diets of low, normal and high zinc contents. The scalded rats fed with normal zinc-containing diet before and after injury were taken as normal control group. The changes of body weight, cumulative nitrogen balance and the contents of DNA and protein in jejunum mucous, liver, kidneys, spleen and testis were employed to represent the nutritional status of the rats. RESULTS: The rats fed with diets with normal and high contents of zinc were superior to those with low content of zinc in terms of body weight, food conversion rate, cumulative nitrogen balance and organ protein contents. The serum zinc level, alkaline phosphatase (ALP) activity and the DNA contents in jejunum mucous, kidneys, spleen and testis increased significantly after zinc supplementation. CONCLUSION: Zinc supplementation was helpful to improve postburn nutritional status in scalded rats. And relative higher amount of zinc supplementation might be beneficial to raise the DNA content in testis and kidneys when compared to that with normal zinc supplement.
OBJECTIVE: To observe postburn metabolic characteristics of zinc and its influence on copper, iron, calcium. METHODS: (1) To analyze the levels of Zn, Cu, Fe, Ca in the serum and urine of burn patient on different postburn days. (2) To replicate a rat model of zinc deficiency and to observe the symptoms and the effects of zinc supplementation in different dosage after scalding in rats with zinc deficiency. (3) To assay the levels of Zn, Cu, Fe, Ca in rat wound tissues following supplementation of zinc in diet and to wounds in rats after scald. RESULTS: (1) The levels of serum Zn and Cu decreased markedly on 1 similar 3 days in major burn patients, whereas the urine Zn and Cu increased obviously, reaching the peak value on the 14th day. The serum and urine Fe increased rapidly on PBD2 and then descended steeply. The serum and urine Ca kept lower levels all along. (2) In zinc deficient rats growth retardation appeared first and other symptoms emerged subsequently. Serum Zn decreased and serum Cu, Fe, Ca increased. (3) The levels of Zn, Cu, Fe, Ca in wound tissue of scalded rats showed a continuous postburn increase. The Ca contents in wound tissue increased about 50 -- fold. Zn content in wound was more obviously increased than Cu, Fe and Ca when Zn was supplemented through wound compared with that with diet supplementation. CONCLUSION: Serum Zn level was lowered after scald and it could be elevated after supplementing zinc by diet or through wound, Changes in serum Cu, Fe, Ca occurred corresponding to the change in serum Zn.
The guanine plus cytosine content (G + C) mol% of Pseudomonas cocovenenans subsp farinofermantans, Burkholderia gladioli and Burkholderia cocovenenans, which were similar in biochemical characteristics, were determined with Tm values method and HPLC method, and the comparative study of these two methods was discussed. A negative conclusion could not be made from the results. The three bacteria were the same species. The HPLC method was more accurate than the Tm values method, but the repeatability of the latter was better.