首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
The skin fascial flap is now recognized as a reliable flap for use in reconstructive surgery. The fasciocutaneous flap has been advocated for coverage of chronic infected wounds after debridement as an alternative to the musculocutaneous flap. Previous experimental and clinical studies have demonstrated the superior resistance of the musculocutaneous flap as compared to the random-pattern flap to bacterial inoculation. A canine model is presented for comparison of the effect of bacterial inoculation in fasciocutaneous and musculocutaneous flaps of similar dimensions. The area of skin necrosis secondary to bacterial inoculation was similar in these two flap types despite greater blood flow and skin oxygen in the fasciocutaneous flap. In a study of closed wound spaces formed by the deep surface of these two flap types, a greater degree of inhibition and elimination of bacterial growth and more collagen deposition are observed in the musculocutaneous wound space than in the fasciocutaneous flap.  相似文献   

2.
A Gosain  N Chang  S Mathes  T K Hunt  L Vasconez 《Plastic and reconstructive surgery》1990,86(6):1152-62; discussion 1163
Regional nutrient blood flow to musculocutaneous and fasciocutaneous flaps was studied in dogs using 15-microns radiolabeled microspheres, and correlations to bacterial inoculation into closed wound spaces were sought. During the 6-day study period, no differences were found between blood flow to noinoculated versus inoculated flaps. Comparisons of blood flow to the deep surfaces of the flaps showed that blood flow to muscle in musculocutaneous flaps increased rapidly during the first 24 hours and then plateaued, while that to subcutaneous tissue plus fascia in fasciocutaneous flaps demonstrated a gradual and steady increase. The most rapid decline in bacterial counts at the undersurface of both flaps occurred within 24 hours, dropping significantly lower within musculocutaneous flaps. In addition to such surface properties of muscle as tissue ingrowth, rapid early augmentation of muscle blood flow may be largely responsible for superior bacterial suppression observed beneath musculocutaneous flaps.  相似文献   

3.
In vitro effect of actinomycin D on human neutrophil function   总被引:1,自引:0,他引:1  
The effect of actinomycin D (ACT-D) on human neutrophil chemotaxis, chemiluminescence (CL), superoxide (O2-) production, phagocytic uptake, and intracellular bacterial killing has been examined. The viability of the ACT-D-treated neutrophils was 98% even at a concentration of 10 micrograms/ml for 4 hr. Using fMLP as the chemotactic factor, depressed chemotaxis was demonstrated following ACT-D (1-10 micrograms/ml) pretreatment of neutrophils as compared with the non-treated controls. Similar ACT-D pretreatment produced the depressed responses in phorbol myristate acetate-induced CL and superoxide production by neutrophils. Moreover, using heat-inactivated human serum as an opsonin for Salmonella enteritidis (NCTC 6676), there was a significant difference in intracellular killing (P less than 0.01) but no difference in phagocytic uptake between ACT-D-treated and non-treated neutrophils. These studies indicate that ACT-D profoundly impairs both intracellular bacterial killing by human neutrophil through an effect on respiratory burst activity and directed cell migration of human neutrophils.  相似文献   

4.
5.
D J Hauben  O Shulman  Y Levi  J Sulkes  A Amir  R Silfen 《Plastic and reconstructive surgery》2001,108(6):1582-8; discussion 1589-90
Sternal wound infection is surgically treated by debridement of the infected sternum and closure of the defect with a muscular flap. These operations tend to be long, stressful, and time-consuming and to involve heavy blood loss. To facilitate wound closure, the SpaceMaker balloon was applied intraoperatively to expand the pectoralis major muscles and enable tensionless closure with musculocutaneous flaps. The aim of the present study was to compare the effectiveness and feasibility of this technique with a variety of others described in the literature. The study population consisted of 40 consecutive patients with sternal wound infection following median sternotomy who were treated with the advancement flap, turnover flap, transposition flap, or SpaceMaker balloon-assisted advancement flap technique (n = 10 each). The balloon-assisted technique was associated with a shorter length of operation and fewer blood transfusions than the other methods. Furthermore, there was no need for reoperation and there were no cases of skin necrosis. In conclusion, closure with the SpaceMaker balloon-assisted bilateral pectoralis major musculocutaneous flap may serve as an adjunctive measure in the treatment of sternal wound infection. This technique seems to have advantages over simple pectoralis major musculocutaneous advancement, particularly for midsternal wounds.  相似文献   

6.
Perforator-based flap in rats: a new experimental model.   总被引:2,自引:0,他引:2  
A new type of flap, the perforator-based flap, has been described in the last decade. It has been used successfully as a pedicle or free flap by many plastic surgeons. There is no animal model for research, although these flaps have gained popularity in clinical use. We created a perforator-based flap model in the rat (a perforator-based flap group and two control groups; 10 rats in each group) and evaluated the survival characteristics of the new flap. The abdominal skin flap was elevated based on the second perforator of the right superior deep epigastric artery and then sutured to its original bed. In the first control group, the same flap was elevated with a subcutaneous pedicle without any perforator; in the second control group, a right-sided, random-pattern pedicle abdominal skin flap with the same dimensions and location was elevated and sutured to its original bed. Flap survival was studied, and microangiography and histologic studies were performed. The amount of viable skin in the three groups was compared 1 week later. The area of surviving skin paddles in the experimental group ranged from 74 to 83 percent; in the first control group, it was 0 percent; and in the second control group, it ranged from 29 to 44 percent (p < 0.001 and p < 0.001, respectively). There was a predictable and constant area of necrosis in the model.The results of this study demonstrate that most of the abdominal skin of the rat can survive on the basis of a single musculocutaneous perforator vessel. This flap can be easily elevated, and it can be used as a reliable model for flap research.  相似文献   

7.
The gluteus maximus island musculocutaneous flap has been described using a variety of designs. We employ an island whose long axis is directed toward the pressure sore, minimizing tension in wound closure. Skin overlying the greater trochanter is avoided. Previously undermined skin can be included in the flap. Fifty patients with ischial or sacral pressure sores have been managed by this technique. Superficial dehiscence occurred in 13 percent of patients, and deep dehiscence occurred in 10 percent. The dehiscence closed spontaneously in all but one patient. Forty-nine of the 50 patients experienced complete wound healing at the pressure sore site. The patients have been observed for an average of 20 months (range 3 to 38 months), with one recurrent pressure sore seen at 28 months postoperatively. The gluteus maximus musculocutaneous island flap has proven to be both reliable in healing and durable over the observed interval.  相似文献   

8.
In this study, the effect of intramuscular injection of human vascular endothelial growth factor (hVEGF) on neovascularization following abdominoplasty was investigated. Twenty-four Sprague-Dawley rats were divided into four groups (n = 6). Two control groups and two experimental groups were established. Abdominoplasty was performed in all rats, with division of all the perforator vessels. In the control groups, normal saline was injected into the rectus abdominis muscle, and in the experimental groups, 100 microg of VEGF and normal saline were injected into the rectus muscle. A transverse rectus abdominis musculocutaneous (TRAM) flap was harvested on day 20 and day 40 in both the control and experimental groups. The range of viability of the TRAM flap was, respectively, 0 to 20 percent (mean, 6.7 percent) and 0 to 25 percent (mean, 14.2 percent) in both short-term and long-term control groups (no VEGF injected). The study (VEGF) group demonstrated a viability of 50 to 80 percent (mean, 70 percent) for the short-term group and 50 to 85 percent (mean, 72.5 percent) in the long-term group. No wound infection was documented, and there were no deaths during the study period. There was no statistically significant difference between the short-term and long-term divisions of the groups (p < 0.01); however, significant differences were observed between the control and experimental groups (p < 0.01). The authors concluded that VEGF injection after abdominoplasty improved the percentage of TRAM flap viability. This method of delay/revascularization could be used for the difficult problem of flap viability following abdominoplasty and for high-risk patients.  相似文献   

9.
Striped bass Morone saxatilis were studied in order to characterize their immune responses over the short term following challenge with Mycobacterium marinum. The expression of immunity-related genes (IL-1beta, TNF-alpha, Nramp and TGF-beta) quickly increased following infection with M. marinum, but these genes were subsequently down-regulated despite the fact that bacterial counts remained high. The number of monocytes and neutrophils also initially increased at 1 d postinfection. This confirms the importance of these types of cells in initial inflammation and mycobacterial infection in striped bass. The phagocytic index of splenic leukocytes over these same time frames did not change significantly following infection. The discrete window in which inflammatory mechanisms were stimulated in striped bass may be related to the intracellular nature of this pathogen.  相似文献   

10.
The effects of a topically applied combination of nonivamide and nicoboxil in improving skin perfusion and preventing distal flap necrosis were tested in a random-pattern dorsal skin flap model. Forty male Wistar rats were randomized into two groups (n = 20), and a standardized dorsal random-pattern skin flap was raised on each rat. Animals in the experimental group were treated with the topically applied drug combination four times per day for 6 days, whereas in the control group only a placebo ointment was applied each time. Skin flap viability was evaluated on day 7, and the extent of skin flap necrosis was compared between the two groups. The topically applied combination of nonivamide and nicoboxil resulted in a statistically significant decrease in skin flap necrosis, compared with the control group (mean percentage of skin flap necrosis in the nonivamide/nicoboxil-treated group, 22.6 +/- 6.0 percent; control group, 36.8 +/- 4.3 percent; p< 0.05). The topical combination of nonivamide and nicoboxil was effective in reducing ischemic necrosis in failing random-pattern skin flaps in this rat model. The results of this study suggest that such a topical drug application might have significant effects in the reduction of ischemic necrosis in the distal parts of skin flaps, and this treatment might also have applications as prophylactic therapy for risky skin flaps.  相似文献   

11.

Background

Patients suffering from diabetes show defective bacterial clearance. This study investigates the effects of elevated plasma glucose levels during diabetes on leukocyte recruitment and function in established models of inflammation.

Methodology/Principal Findings

Diabetes was induced in C57Bl/6 mice by intravenous alloxan (causing severe hyperglycemia), or by high fat diet (moderate hyperglycemia). Leukocyte recruitment was studied in anaesthetized mice using intravital microscopy of exposed cremaster muscles, where numbers of rolling, adherent and emigrated leukocytes were quantified before and during exposure to the inflammatory chemokine MIP-2 (0.5 nM). During basal conditions, prior to addition of chemokine, the adherent and emigrated leukocytes were increased in both alloxan- (62±18% and 85±21%, respectively) and high fat diet-induced (77±25% and 86±17%, respectively) diabetes compared to control mice. MIP-2 induced leukocyte emigration in all groups, albeit significantly more cells emigrated in alloxan-treated mice (15.3±1.0) compared to control (8.0±1.1) mice. Bacterial clearance was followed for 10 days after subcutaneous injection of bioluminescent S. aureus using non-invasive IVIS imaging, and the inflammatory response was assessed by Myeloperoxidase-ELISA and confocal imaging. The phagocytic ability of leukocytes was assessed using LPS-coated fluorescent beads and flow cytometry. Despite efficient leukocyte recruitment, alloxan-treated mice demonstrated an impaired ability to clear bacterial infection, which we found correlated to a 50% decreased phagocytic ability of leukocytes in diabetic mice.

Conclusions/Significance

These results indicate that reduced ability to clear bacterial infections observed during experimentally induced diabetes is not due to reduced leukocyte recruitment since sustained hyperglycemia results in increased levels of adherent and emigrated leukocytes in mouse models of type 1 and type 2 diabetes. Instead, decreased phagocytic ability observed for leukocytes isolated from diabetic mice might account for the impaired bacterial clearance.  相似文献   

12.
Postoperative wound infection, most often with, is of ubiquitous concern in surgical practice, occurring in an average of 1.5 to 5 percent of all procedures. The antimicrobial properties of local anesthetics have been documented over the past 25 years by in vitro studies. This study evaluates the effects of lidocaine preparations on in an in vivo setting. In a wound infection model using live albino guinea pigs, inoculum was introduced for the reproducible bacterial colonization of clean surgical wounds. One of two sites on the dorsum of each animal was infiltrated with a commercial lidocaine preparation (with and without epinephrine) prior to inoculation with (10 cfu/ml). The other site, inoculated with without preinfiltration with lidocaine, served as the control. Cultures from the sites treated with lidocaine were then compared with cultures from the control sites. All control sites had a consistent presence >or=10 cfu/ml, the threshold for bacterial inhibition of wound healing. Infiltration of the wound with 2 ml of 2% lidocaine prior to inoculation was associated with an average decrease in bacterial count of >70 percent ( n= 19). On the other hand, the addition of epinephrine (1:100,000) to lidocaine was associated with a 20-fold in bacterial counts compared with control values ( n= 10). This is the first study to demonstrate inhibition of by a local anesthetic agent in an in vivo model of a surgical wound. This information suggests a possible role for local anesthetics in prophylaxis against surgical wound infection.  相似文献   

13.
Several lines of evidence show that platelet endothelial cell adhesion molecule-1 (PECAM-1), a component of endothelial cell junctions, is required for leukocyte transmigration through endothelial cell monolayers. Polymorphonuclear leukocytes play an important role in ischemia-reperfusion injury. We sought to determine whether administering an anti-PECAM-1 antibody would prevent or attenuate ischemia-reperfusion injury in a rat cremaster muscle flap injury model. Eighteen male Sprague-Dawley rats were divided into three groups. Group I (control): Cremaster muscle island flaps were dissected for baseline measurements of eight indicators: numbers of rolling, sticking, and transmigrating neutrophils, numbers of rolling and sticking lymphocytes, number of perfused capillaries, endothelial edema, and vessel permeability. Group II: The prepared cremaster flap was subjected to 4 hours of ischemia and 24 hours of reperfusion. Group III: The muscle flap was subjected to ischemia and reperfusion as in group II, and anti-PECAM-1 antibodies (1 mg/kg) were injected subcutaneously 15 minutes before reperfusion. Blood vessels were observed in vivo under an intravital microscopy system. Microvascular permeability was made visible with injected fluorescein isothiocyanate-labeled albumin and evaluated with Kontron Elektronik computer software. The ischemia-reperfusion-alone group (group II) presented a 225-percent increase in the activation of sticking leukocytes (2.4 +/- 0.4 to 7.8 +/- 0.8, p < 0.05) (p < 0.01). This leukocyte activation was reduced by 83 percent following anti-PECAM-1 monoclonal antibody treatment (1.3 +/- 0.5 per 100 microm) (p < 0.01). At 24 hours, endothelial injury in group II was confirmed by a 4-fold increase in the number of transmigrating leukocytes into the interstitial space (7.6 +/- 1.2 per field versus 1.9 +/- 0.4 per field in controls). This phenomenon was reduced by 85 percent following anti-PECAM-1 monoclonal antibody treatment (1.1 +/- 0.2 per field) (p < 0.01). Analysis showed that the number of flowing capillaries was 67 percent lower in group II (6.8 +/- 0.3 to 2.2 +/- 0.7, p < 0.01). Anti-PECAM-1 antibody treatment caused a 2.5-fold increase in this number (5.6 +/- 0.5, p < 0.01). Microcirculatory permeability index showed a 180-percent increase in group II (p < 0.05) when compared with baseline values. This increased albumin leakage was effectively attenuated by antibody treatment (p < 0.05). Blocking the action of PECAM-1 in vivo by administering monoclonal antibodies significantly attenuated ischemia-reperfusion injury, presumably by inhibiting transendothelial migration of neutrophils and by increasing capillary perfusion at a muscle flap microcirculatory level.  相似文献   

14.
Abstract Several studies have demonstrated that Bordetella pertussis has the ability to enter and survive intracellularly within human polymorphonuclear leukocytes (PMNL) and human monocytes/macrophages. The effects of human recombinant gamma interferon (IFN-γ) on the survival of B. pertussis in PMNL and human monocytes, and on the oxidative burst activity of PMNL and human monocytes in response to B. pertussis were assessed in this study. IFN-γ partially increased intracellular killing of phagocytosed B. pertussis in human monocytes, as determined by an orange acridine-crystal violet assay. In contrast, IFN-γ did not enhance intracellular killing of B. pertussis in PMNL. No significant increase of superoxide production was noted in human monocytes in response to B. pertussis when stimulated with various concentrations of IFN-γ. The partial increase of B. pertussis killing by IFN-γ within monocytes, together with poor production of superoxide may explain how B. pertussis can survive within human phagocytic cells, and thus cause a more prolonged course of the disease.  相似文献   

15.
The trauma and sepsis that follow open fractures and wounds may lead to the production of various cytokines. Understanding wound healing requires a direct knowledge of the specific cytokines and the respective wound fluid levels that are present at the wound site. An animal model was designed that mimics the open fracture and the clinical repair of the human, high-energy open fracture. Canine right tibiae were fractured with a penetrating, captive-bolt device, then repaired in a standard clinical fashion using an interlocking intramedullary nail. Before primary wound closure, microdialysis probes were placed at the fracture site and in a muscle located at a contralateral site. Canines received one of the following experimental protocols: (1) tibial fracture (n = 5); (2) tibial fracture plus Staphylococcus aureus inoculation at the fracture site (n = 5); and (3) tibial fracture, S. aureus inoculation, and a rotational gastrocnemius muscle flap (n = 5). Microdialysis fluid samples were collected intermittently for 7 days. Tumor necrosis factor alpha (TNFalpha) levels at the fracture site were significantly elevated 3 to 34-fold (p<0.02), as compared with respective serum levels at all time points for all treatment groups. Fracture site TNFalpha levels were elevated (p<0.02) in days 1 through 6, as compared with the baseline and contralateral in all treatment groups. At days 1 through 6, the TNFalpha levels of the muscle flap group fracture site were significantly decreased by approximately 50 percent (p<0.05), as compared with the fractures without muscle flaps and regardless of additional S. aureus inoculation. On day 7, fracture site TNFalpha levels in all animal groups were similar, yet remained well above those of baseline TNFalpha. These results demonstrate that S. aureus does not further elevate TNFalpha levels in the presence of an open fracture and that a muscle flap reduces pro-inflammatory TNFalpha levels during early wound healing. This experimental model allows for the characterization of specific biological signals and cellular pathways that are influenced by bacterial infection and surgical closure. These data provide a scientific framework on which to judge or validate therapeutic regimens for open-fracture wound healing.  相似文献   

16.
Flow cytometric evaluation of leukocyte function in rat whole blood   总被引:1,自引:0,他引:1  
The aim of this study was to establish a standard flow cytometric method to measure the phagocytic function of and intracellular hydrogen peroxide (H2O2) production by rat leukocytes. Thirty-six adult, male Sprague-Dawley rats were included in this study. Whole-blood specimens from the inferior vena cava were collected in a heparinized tube and ethylenediaminetetraacetic acid (EDTA) anticoagulated tube. The phagocytic function of and intracellular H2O2 generation by leukocytes were measured with FACS Vantage trade mark flow cytometer (Becton Dickinson, San Jose, CA), using fluorescent microspheres and dihydrorhodamine-123 as probes, respectively. Several conditions were optimized in this study, including anticoagulants (heparin and EDTA), fluorescent probes (0.75- and 1.72-microm-diameter microspheres), incubation time, and concentration of the chemicals used in the experiment. Neutrophils, monocytes, and lymphocytes could be clearly defined and separated in whole blood by flow cytometry and tested for phagocytosis and intracellular H2O2 generation without the need for further purification and handling of the cells. Intracellular H2O2 production by and phagocytic function of neutrophils and monocytes were inhibited in EDTA-anticoagulated blood compared with heparin- anticoagulated blood (P < 0.01). Neutrophils showed similar phagocytic function to 0.75- and 1.72-microm microspheres, but monocytes showed weak phagocytic activity to 1.72-microm beads compared with 0.75-microm beads (P < 0.01). In conclusion, a flow cytometric method to measure the phagocytic function of and intracellular H2O2 production by rat leukocytes has been developed. Quantitative flow cytometric analysis of rat leukocyte function is convenient and feasible and provides a reliable and rapid assay to assess phagocytosis and intracellular H2O2 production by rat neutrophils and monocytes.  相似文献   

17.
Dynamic and physiologic studies objectively comparing the attributes of the transverse rectus abdominis musculocutaneous (TRAM) and deep inferior epigastric perforator (DIEP) flaps would be most practical in an animal model. This has now been accomplished using the ventral abdomen of the Sprague-Dawley rat. A conventional TRAM flap, a multiple perforator DIEP flap, and a solitary perforator DIEP flap were raised in three equal groups of five rats each. Flow studies using laser Doppler flowmetry demonstrated the highest flow in zone I in the TRAM flap group (87.6 +/- 15.4 percent), which was a statistically significant difference from the multiple perforator DIEP flap group (45.4 +/- 13.3 percent) and the solitary perforator DIEP flap group (43.4 +/- 26.4 percent) (p = 0.005). Flow in zone IV was proportionately lower for all groups, with no significant difference noted between TRAM and DIEP flaps (p = 0.736). Although ultimate flap survival was greatest for the TRAM flap group (96.1 +/- 6.7 percent) when compared with the multiple perforator DIEP flap (79.8 +/- 15.2 percent) or the solitary perforator DIEP flap groups (77.1 +/- 23.0 percent), this difference was not statistically significant (p = 0.183). In summary, relative flow to these rat ventral abdomen models was directly proportional to the number of retained musculocutaneous perforators, but a single perforator only could routinely allow near-total survival.  相似文献   

18.
A rapidly growing body of experimental evidence indicates that defects in leukocyte motility and chemotactic response correlate with increased susceptibility to and severity of bacterial infection in tissue. While this is understandable in qualitative terms, the sensitivity of the correlation is remarkable.In the present study, a theoretical analysis has been developed to relate the dynamics of bacterial growth to the growth and transport parameters of bacteria and leukocytes in tissue. The model considers a local tissue region in the vicinity of a venule and applies continuum unsteady state species conservation equations to the bacterial population, the phagocytic leukocytes, and a chemotactically active chemical mediator assumed to be produced by the bacteria. The analysis quantifies the effects of key parameters, such as leukocyte random motility and chemotactic coefficients, phagocytic and growth rate constants, and leukocyte vessel wall permeability, upon host ability to eliminate the bacteria.As an example, the model's predictions are compared to experimental results correlating inhibition of leukocyte chemotaxis by hemoglobin with its adjuvant action in experimental peritoneal infection by E. coli.  相似文献   

19.
Bacterial ingestion and killing by phagocytic cells are essential processes to protect the human body from infectious microorganisms. However, only few proteins implicated in intracellular bacterial killing have been identified to date. We used Dictyostelium discoideum, a phagocytic bacterial predator, to study intracellular killing. In a random genetic screen we identified Kil2, a type V P-ATPase as an essential element for efficient intracellular killing of Klebsiella pneumoniae bacteria. Interestingly, kil2 knockout cells still killed efficiently several other species of bacteria, and did not show enhanced susceptibility to Mycobacterium marinum intracellular replication. Kil2 is present in the phagosomal membrane, and its structure suggests that it pumps cations into the phagosomal lumen. The killing defect of kil2 knockout cells was rescued by the addition of magnesium ions, suggesting that Kil2 may function as a magnesium pump. In agreement with this, kil2 mutant cells exhibited a specific defect for growth at high concentrations of magnesium. Phagosomal protease activity was lower in kil2 mutant cells than in wild-type cells, a phenotype reversed by the addition of magnesium to the medium. Kil2 may act as a magnesium pump maintaining magnesium concentration in phagosomes, thus ensuring optimal activity of phagosomal proteases and efficient killing of bacteria.  相似文献   

20.
The recycling of a skin territory as part of a musculocutaneous flap despite prior division of existing musculocutaneous perforators or vice versa within an axial cutaneous flap using skin from a previous musculocutaneous flap may sometimes be done safely if an adequate time period has been allotted to permit sufficient neovascularization from adjacent tissues. In order to test this clinically observed phenomenon, a musculocutaneous flap model based on perforators from the rat rectus abdominis muscle was developed and observed to have complete reliability. Groups of five Sprague-Dawley rats each were sequentially utilized to prove that by a single week following creation of a rectus abdominis musculocutaneous flap adequate peripheral neovascularization would evolve to permit total viability of secondary axial epigastric cutaneous flaps incorporating the same skin that initially was the cutaneous portion of the muscle flap. The converse was also confirmed possible, again using sequential groups of five rats each, in that by 2 weeks the skin of an initial abdominal cutaneous flap could instead be safely transposed and nourished as part of a rectus abdominis musculocutaneous flap. The proposition concerning the reliable reuse of identical skin territories as part of disparate metachronous flap configurations appears to be valid.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号