The effect of Wharton's jelly-derived stem cells seeded/boron-loaded acellular scaffolds on the healing of full-thickness burn wounds in the rat model

Burn wounds are the most destructive and complicated type of skin or underlying soft tissue injury that are exacerbated by a prolonged inflammatory response. Several cell-based therapeutic systems through the culturing of potent stem cells on modified scaffolds have been developed to direct the burn healing challenges. In this context, a new regenerative platform based on boron (B) enriched-acellular sheep small intestine submucosa (AOSIS) scaffold was designed and used as a carrier for mesenchymal stem cells derived from Wharton's jelly (WJMSCs) aiming to promote the tissue healing in burn-induced rat models. hWJMSCs have been extracted from human extra-embryonic umbilical cord tissue. Thereafter, 96 third-degree burned Wistar male rats were divided into 4 groups. The animals that did not receive any treatment were considered as group A (control). Then, group B was treated just by AOSIS scaffold, group C was received cell-seeded AOSIS scaffold (hWJMSCs-AOSIS), and group D was covered by boron enriched-cell-AOSIS scaffold (B/hWJMSCs-AOSIS). Inflammatory factors, histopathological parameters, and the expression levels of epitheliogenic and angiogenic proteins were assessed on 5, 14 and 21 d post-wounding. Application of the B/hWJMSCs-AOSIS on full-thickness skin-burned wounds significantly reduced the volume of neutrophils and lymphocytes at day 21 post-burning, whilst the number of fibroblasts and blood vessels enhanced at this time. In addition, molecular and histological analysis of wounds over time further verified that the addition of boron promoted wound healing, with decreased inflammatory factors, stimulated vascularization, accelerated re-epithelialization, and enhanced expression levels of epitheliogenic genes. In addition, the boron incorporation amplified wound closure via increasing collagen deposition and fibroblast volume and activity. Therefore, this newly fabricated hWJMSCs/B-loaded scaffold can be used as a promising system to accelerate burn wound reconstruction through inflammatory regulation and angiogenesis stimulation.

Recent advances of exosomes in soft tissue injuries in sports medicine: A critical review on biological and biomaterial applications

Sports medicine is generally associated with soft tissue injuries including muscle injuries, meniscus and ligament injuries, tendon ruptures, tendinopathy, rotator cuff tears, and tendon-bone healing during injuries. Tendon and ligament injuries are the most common sport injuries accounting for 30-40% of all injuries. Therapies for tendon injuries can be divided into surgical and non-surgical methods. Surgical methods mainly depend on the operative procedures, the surgeons and postoperative interventions. In non-surgical methods, cell therapy with stem cells and cell-free therapy with secretome of stem cell origin are current directions. Exosomes are the main paracrine factors of mesenchymal stem cells (MSCs) containing biological components such as proteins, nucleic acids and lipids. Compared with MSCs, MSC-exosomes (MSC-exos) possess the capacity to escape phagocytosis and achieve long-term circulation. In addition, the functions of exosomes from various cell sources in soft tissue injuries in sports medicine have been gradually revealed in recent years. Along with the biological and biomaterial advances in exosomes, exosomes can be designed as drug carriers with biomaterials and exosome research is providing promising contributions in cell biology. Exosomes with biomaterial have the potential of becoming one of the novel therapeutic modalities in regenerative researches. This review summarizes the derives of exosomes in soft tissue regeneration and focuses on the biological and biomaterial mechanism and advances in exosomal therapy in soft tissue injuries.

Cytokine patterns in the blister fluid and plasma of patients with fracture blisters

BACKGROUND

Fracture blister (FB) is a complication of fracture, which damages to the skin integrity and increases the risk of infection. Inflammation plays an important role in the formation and development of FBs, but its specific mechanism is still unclear. The aim of this study was to investigate the patterns and dynamic changes of inflammatory cytokines in fracture blister fluid (FBF) and plasma.

MATERIALS AND METHODS

FBF and plasma were collected simultaneously from patients with lower extremity fractures with FBs on the first and fifth day after blisters formation. 92 inflammation-related protein biomarkers were measured in plasma and FBF using Proximity Extension Assay (PEA). We analyzed the cytokine patterns and their dynamic changes in FBF and plasma. Cytokine patterns in plasma from FB patients, fracture without blister patients, and healthy subjects were also analyzed.

RESULT

The cytokine pattern in FBF and plasma of patients with FBs was different but 11 cytokines were significantly correlated in the two sample types. 23 cytokines were different in plasma across FB patients, fracture without blister patients and healthy subjects. In the analysis of plasma from FB patients and fracture without blister patients, 15 cytokines were significantly different and they may be potential risk factors for the occurrence of FBs. The FBF and plasma showed different cytokine patterns in the early and late stages, with 50 cytokines significantly changed in FBF and 20 cytokines in plasma.

CONCLUSION

The different cytokine patterns in plasma between FB patients and fracture without blisters patients may be the potential factors for the occurrence of blisters. The cytokine patterns in FBF and plasma showed a dynamic change from the inflammatory stage to the proliferative and repair stage, which indicates that FBs may have new clinical importance in addition to being a soft tissue injury.

[Effects of mechanical tension on the formation of hypertrophic scars in rabbit ears and transforming growth factor-β1/Smad signaling pathway]

Objective: To explore the effects of mechanical tension on the formation of hypertrophic scars in rabbit ears and transforming growth factor-β1 (TGF-β1)/Smad signaling pathway. Methods: The experimental research method was adopted. Six New Zealand white rabbits, male or female, aged 3-5 months were used and 5 full-thickness skin defect wounds were made on the ventral surface of each rabbit ear. The appearance of all rabbit ear wounds was observed on post surgery day (PSD) 0 (immediately), 7, 14, 21, and 28. On PSD 28, the scar formation rate was calculated. Three mature scars in the left ear of each rabbit were included in tension group and the arch was continuously expanded with a spiral expander. Three mature scars in the right ear of each rabbit were included in sham tension group and only the spiral expander was sutured without expansion. There were 18 scars in each group. After mechanical tension treatment (hereinafter referred to as treatment) for 40 days, the color and texture of scar tissue in the two groups were observed. On treatment day 40, the scar elevation index (SEI) was observed and calculated; the histology was observed after hematoxylin eosin staining, and the collagen morphology was observed after Masson staining; mRNA expressions of TGF-β1, Smad3, collagen Ⅰ, collagen Ⅲ, and α-smooth muscle actin (α-SMA) in scar tissue were detected by real-time fluorescence quantitative reverse transcription polymerase chain reaction; and the protein expressions of TGF-β1, collagen Ⅰ, collagen Ⅲ, and α-SMA, and phosphorylation level of Smad3 in scar tissue were detected by Western blotting. The number of samples of each group in the experiments was 3. Data were statistically analyzed with independent sample t test. Results: On PSD 0, 5 fresh wounds were formed on all the rabbit ears; on PSD 7, the wounds were scabbed; on PSD 14, most of the wounds were epithelialized; on PSD 21, all the wounds were epithelialized; on PSD 28, obvious hypertrophic scars were formed. The scar formation rate was 75% (45/60) on PSD 28. On treatment day 40, the scar tissue of rabbit ears in tension group was more prominent than that in sham tension group, the scar tissue was harder and the color was more ruddy; the SEI of the scar tissue of rabbit ears in tension group (2.02±0.08) was significantly higher than 1.70±0.08 in sham tension group (t=5.07, P<0.01). On treatment day 40, compared with those in sham tension group, the stratum corneum of scar tissue became thicker, and a large number of new capillaries, inflammatory cells, and fibroblasts were observed in the dermis, and collagen was more disordered, with nodular or swirling distribution in the scar tissue of rabbit ears in tension group. On treatment day 40, the mRNA expressions of TGF-β1, Smad3, collagen Ⅰ, collagen Ⅲ, and α-SMA in the scar tissue of rabbit ears in tension group were respectively 1.81±0.25, 5.71±0.82, 7.86±0.56, 4.35±0.28, and 5.89±0.47, which were significantly higher than 1.00±0.08, 1.00±0.12, 1.00±0.13, 1.00±0.14, and 1.00±0.14 in sham tension group (with t values of 5.36, 9.82, 20.60, 18.26, and 17.13, respectively, all P<0.01); the protein expressions of TGF-β1, collagen Ⅰ, collagen Ⅲ, and α-SMA, and phosphorylation level of Smad3 in the scar tissue of rabbit ears in tension group were respectively 0.865±0.050, 0.895±0.042, 0.972±0.027, 1.012±0.057, and 0.968±0.087, which were significantly higher than 0.657±0.050, 0.271±0.029, 0.631±0.027, 0.418±0.023, and 0.511±0.035 in sham tension group (with t values of 5.08, 21.27, 15.55, 16.70, and 8.40, respectively, all P<0.01). Conclusions: Mechanical tension can inhibit the regression of hypertrophic scars in rabbit ears through stimulating the hyperplasia of scars, inhibiting the normal arrangement of dermal collagen fibers, and intensifying the deposition of collagen fibers, and the mechanism may be related to the activation of TGF-β1/Smad signaling pathway by mechanical tension.

Inflammation Self-Limiting Electrospun Fibrous Tape via Regional Immunity for Deep Soft Tissue Repair

Overexpression of inflammatory cytokines and chemokines occurs at deep soft tissue injury sites impeding the inflammation self-limiting and impairing the tissue remodeling process. Inspired by the electrostatically extracellular matrix (ECM) binding property of the inflammatory signals, an inflammation self-limiting fibrous tape is designed by covalently modifying the thermosensitive methacrylated gelatin (GelMA) and negatively charged methacrylated heparin (HepMA) hydrogel mixture with proper ratio onto the electrospun fibrous membrane by mild alkali hydrolysis and carboxyl-amino condensation reaction to restore inflammation self-limiting and promote tissue repair via regional immunity regulation. While the GelMA guarantees cell compatibility, the negatively charged HepMA successfully adsorbs the inflammatory cytokines and chemokines by electrostatic interactions and inhibits immune cell migration in vitro. Furthermore, in vivo inflammation self-limiting and regional immunity regulation efficacy is evaluated in a rat abdominal hernia model. Reduced local inflammatory cytokines and chemokines in the early stage and increased angiogenesis and ECM remodeling in the later phase confirm that the tape is an approach to maintain an optimal regional immune activation level after soft tissue injury. Overall, the reported electrospun fibrous tape will find its way into clinical transformation and solve the challenges of deep soft tissue injury.

A novel rat model of tibial fracture for trauma researches: a combination of different types of fractures and soft tissue injuries

BACKGROUND

The outcomes for open tibial fractures with severe soft tissue injury are still a great challenge for all the trauma surgeons in the treatment. However, most of the existing open tibial fracture models can only provide minimal soft tissue injury which cannot meet the requirement of severe trauma research. Our goal is to investigate a novel tibial fracture model providing different fractures combined with soft tissue injury for better application in trauma research.

METHODS

A total of 144 Sprague-Dawley rats were randomly divided into 4 groups. With group 1 as control, the other groups sustained different right tibial fractures by the apparatus with buffer disc settings either 3 mm, 10 mm, or 15 mm. X-ray and computed tomography angiography (CTA) were performed at 6 h to evaluate the fracture patterns and vascular injuries. Peripheral blood and tibialis anterior muscle were harvested at 6 h, 1 day, 3 days, 7 days, 14 days, and 28 days for ELISA and histological analysis.

RESULTS

X-ray and μCT results indicated that different fractures combined with soft tissue injuries could be successfully provided in this model. According to OTA and Gustilo classification, the fractures and soft tissue injuries were evaluated and defined: 36 type I in group 2, 34 type II in group 3, and 36 type III in group 4. The CTA confirmed no arterial injuries in groups 1 and 2, 2 arterial injuries in group 3, and 35 in group 4. ELISA indicated that the levels of pro-inflammatory cytokines TNF-α and IL-1β were significantly higher in group 4 than in other groups, and the levels of anti-inflammatory cytokines TGF-β and IL-10 were significantly higher in surgery groups than in group 1 in later stage or throughout the entire process. HE, Masson, and caspase-3 stains confirmed the most severe inflammatory cell infiltration and apoptosis in group 4 which lasted longer than that in groups 2 and 3.

CONCLUSIONS

The novel apparatus was valuable in performing different fractures combined with soft tissue injuries in a rat tibial fracture model with high reproducibility and providing a new selection for trauma research in the future.

Microdialysis Sampling from Wound Fluids Enables Quantitative Assessment of Cytokines, Proteins, and Metabolites Reveals Bone Defect-Specific Molecular Profiles

Bone healing involves a variety of different cell types and biological processes. Although certain key molecules have been identified, the molecular interactions of the healing progress are not completely understood. Moreover, a clinical routine for predicting the quality of bone healing after a fracture in an early phase is missing. This is mainly due to a lack of techniques to comprehensively screen for cytokines, growth factors and metabolites at their local site of action. Since all soluble molecules of interest are present in the fracture hematoma, its in-depth assessment could reveal potential markers for the monitoring of bone healing. Here, we describe an approach for sampling and quantification of cytokines and metabolites by using microdialysis, combined with solid phase extractions of proteins from wound fluids. By using a control group with an isolated soft tissue wound, we could reveal several bone defect-specific molecular features. In bone defect dialysates the neutrophil chemoattractants CXCL1, CXCL2 and CXCL3 were quantified with either a higher or earlier response compared to dialysate from soft tissue wound. Moreover, by analyzing downstream adaptions of the cells on protein level and focusing on early immune response, several proteins involved in the immune cell migration and activity could be identified to be specific for the bone defect group, e.g. immune modulators, proteases and their corresponding inhibitors. Additionally, the metabolite screening revealed different profiles between the bone defect group and the control group. In summary, we identified potential biomarkers to indicate imbalanced healing progress on all levels of analysis.

[METABOLIC INTOXICATION IN THERMIC TRAUMA]

In 76 injured persons with deep and superficial burns, having area from 3 to 65% of the total body surface and ageing 5-16 yrs old, there was investigated the impact of early surgical treatment on the metabolic intoxication severity in accordance to content of the oxidatively modified proteins carbonyl groups in the blood serum, and of a ceruloplasmin, what was considered as integral express-index of the organism antioxidant system state. Changes of these indices in ambustial disease of middle severity have witnessed a sufficiently compensated reaction of organism: of severe and extremely severe one--there were noted a deficiency of the organism antioxidant defense; and in stages of toxemia and septicotoxemia--attrition of the organism oxidant reserves and danger of the septic complications occurrence. Conduction of early surgical intervention have guaranteed maintenance of a ceruloplasmin content in stages of toxemia and septicotoxemia on the level of healthy persons, relief of the ambustial disease course, absence of critical metabolic intoxication and carbonyl stress, reduction of the septic complications rate in 1.5 times.

[The effect of acupuncture stimulation of Ashi-point on hepatocyte growth factor expression in the soft tissue in acute contusion rats]

OBJECTIVE

To observe the effect of acupuncture stimulation of Ashi-point on hepatocyte growth factor (HGF) protein expression in gastrocnemius muscle (GM) in rats with traumatic injury of GM, so as to reveal its mechanism underlying improvement of traumatic injury of skeletal muscle.

METHODS

A total of 80 SD rats were randomly divided into normal control (n = 8), model, acupuncture control, and acupuncture treatment groups, and the latter 3 groups were further allocated to 0 h, 24 h and 48 h subgroups (n = 8 in each subgroup). The acute soft tissue contusion model was established by using 500 g-counterweight free falling hitting at the GM of the right leg (height 30 cm). The Ashi-point was punctured with a piece of filiform needle by penetrating the site beside the injured GM, and stimulated for about 5 seconds. For acupuncture control group, acupuncture was performed in the same Ashi-point in normal rats. Pathological changes of the focal GM were observed by H. E. staining and HGF protein expression of GM was detected by Western blot.

RESULTS

H.E. staining showed that different degrees of injury of GM tissue including broken muscle fibers with cellular swelling, inflammatory cell infiltration, muscle fibrinolysis, atrophy, degeneration and necrosis, etc., were found at each time-point after modeling, while in the acupuncture treatment group, the severity of muscle injury was relatively milder particularly at the time-points of 24 h and 48 h. Compared with the normal control group, HGF protein expression levels of GM at the 3 time-points in the model group, and at 48 h in the acupuncture control group were markedly increased (P<0.05, P<0.01); while in comparison with the model group, HGF protein expression levels were remarkably down-regulated at 24 h and 48 h after acupuncture treatment (P<0.01, P<0.05).

CONCLUSION

Acupuncture stimulation of Ashi-point can significantly down-regulate HGF protein expression in the GM in soft tissue contusion rats, which may contribute to its effects in relieving contusion injury of skeletal muscle.

[Expressions of tumor necrosis factor-alpha and NF-kappa B in skeletal muscles and its effect on apoptosis in deep tissue injury of rats]

OBJECTIVE

To evaluate the changes of tumor necrosis factor-alpha (TNF-alpha) and nuclear factor-kappaB (NF-kappaB) expression in muscle of pressure ulcer rats and explore the relationship with apoptosis.

METHODS

Fifty-four male SD rats were randomly divided into nine groups (n = 6), the experiment groups were pressed 9 circles (3 circles/day, 3 days), then observed on the 1st, 3rd, hematoxylin and eosin staining under the microscope; the expression of TNF-alpha was detected by Western blot; the expressions of NF-kappaB and caspase-3 were determined by immunohistochemistry, and evaluated the relationship of TNF-alpha with NF-kappaB and caspase-3; the number of apoptotic cells in compressed muscle tissue was detected by Hoechst 33258 staining under the fluorescence microscope.

RESULTS

Compared with the control group, histology examination showed that the tissue structure in experiment groups was in disorder, inter-space was wider, cell edema and the number of inflammatory cells were increased, the tissue was arranged in order and inflammatory cell recruitment was gradually attenuated. The expressions of TNF-alpha, NF-kappaB and caspase-3 were higher in the experiment groups than those in the control group (P < 0.05), reached their peak on the first day, gradually decreased on the 3nd day, but still had a significantly higher level than that in the control group (P < 0.01) on the 7th day; The number of apoptotic cells of experiment groups had a downward trend after the first rise under the fluorescence microscope; the expressions of TNF-alpha and NF-kappaB caspase-3 were found to have positive correlationship (P < 0.05), the expressions of NF-kappaB and caspase-3 were found to have positive correlationship (P < 0.01).

CONCLUSION

Apoptosis is closely correlated with inflammation in deep tissue injury of pressure ulcer, NF-kappaB plays a role not only in the formation of inflammation, but also triggering apoptosis, which may induce the pathological change and clinical progress of pressure ulcer.

Hepatic growth hormone resistance after acute injury

Severe injury and infection are often followed by accelerated protein catabolism and acute insulin resistance. This results in several effects that complicate and prolong recovery, including weakness, immobility, impaired wound healing, and organ dysfunction. Recent studies have demonstrated the development of GH resistance during severe inflammation, providing a potential mechanism for the protein loss that follows injury and infection. To understand this GH resistance, we recently developed a murine model of acute injury. Mice were subjected to soft-tissue injury, alone or combined with hemorrhage, and injected iv with GH 30, 60, or 90 minutes later. Hepatic GH signaling was measured via Western analysis. GH-induced signal transducer and activator of transcription 5 phosphorylation was decreased immediately after completion of the trauma procedure, and at 30 and 60 minutes, but further decreased by 90 minutes after trauma. Combined trauma and hemorrhage resulted in severely decreased GH-induced signal transducer and activator of transcription 5 phosphorylation compared with trauma alone, and this was true at all time points studied. Western analysis revealed an apparent decrease in the molecular weight of the hepatic GH receptor (GHR) after trauma and hemorrhage, but not trauma alone. Additional studies determined that the hemorrhage-induced decrease in receptor size was not due to changes in GHR N-linked glycosylation. These results suggest that GH sensitivity is rapidly impaired after acute injury and that trauma combined with hemorrhage results in a more severe form of GH resistance resulting from alteration or inactivation of hepatic GHR.

[Effect of curing-injury Cataplasma on expression of AQP-3 in skeletal muscle of rat model with acute injury in soft tissues]

OBJECTIVE

To observe the effect of curing-injury cataplasma on the expression of aquaporin protein 3 (AQP-3) in skeletal muscle of rat model with acute injury in soft tissues.

METHODS

A total of 54 SD rats were randomly divided into 3 groups, and by using 10% sodium sulfide the depilating treatment was made in the thigh lateral of each left hind leg 1 day before modeling. The depilatory area in the control group was merely marked with striking range, not attacked for modeling. In the depilatory area of the modeling group, the blowing apparatus was used to attack the marked range to establish the model of soft tissue swelling with acute injury, to which none medication was given. In the drug treatment group, immediately after establishing the model of soft tissue swelling with acute injury, curing-injury cataplasma was scattered on the stricken area, and fixed with bandage. After the modeling, the rats were killed at 1 h, 6 h, 1 d, 3 d, 5 d, and 7 d, 3 rats in each group at each time point. In the marked area some tissue was taken, and the dry/wet proportion method was used to detect the water content in the skeletal muscle. Western blot and qPCR method were used for the AQP-3 protein and the level of gene expression.

RESULTS

At the six time points, for the modeling and drug treatment groups, the water content of skeletal muscle was higher than that of the control group (P<0.05). At 3 d, 5 d and 7 d, the water content in the drug treatment group was lower than that of the modeling group (P<0.01); for the modeling and drug treatment groups, AQP-3 protein and the level of gene expression were higher than those of the control group. There was significant difference between the drug treatment group and the modeling group (P<0.01).

CONCLUSION

Curing-injury cataplasma can relieve soft tissue swelling with acute injury, and accelerate the repair process after the injury.

Effects of low-level laser therapy (GaAs) in an animal model of muscular damage induced by trauma

It has been demonstrated that reactive oxygen species (ROS) formation and oxidative damage markers are increased after muscle damage. Recent studies have demonstrated that low-level laser therapy (LLLT) modulates many biochemical processes mainly those related to reduction of muscular injures, increment of mitochondrial respiration and ATP synthesis, as well as acceleration of the healing process. The objective of the present investigation was to verify the influence of LLLT in some parameters of muscular injury, oxidative damage, antioxidant activity, and synthesis of collagen after traumatic muscular injury. Adult male Wistar rats were divided randomly into three groups (n = 6), namely, sham (uninjured muscle), muscle injury without treatment, and muscle injury with LLLT (GaAs, 904 nm). Each treated point received 5 J/cm(2) or 0.5 J of energy density (12.5 s) and 2.5 J per treatment (five regions). LLLT was administered 2, 12, 24, 48, 72, 96, and 120 h after muscle trauma. The serum creatine kinase activity was used as an index of skeletal muscle injury. Superoxide anion, thiobarbituric acid reactive substance (TBARS) measurement, and superoxide dismutase (SOD) activity were used as indicators of oxidative stress. In order to assess the synthesis of collagen, levels of hydroxyproline were measured. Our results have shown that the model of traumatic injury induces a significant increase in serum creatine kinase activity, hydroxyproline content, superoxide anion production, TBARS level, and activity of SOD compared to control. LLLT accelerated the muscular healing by significantly decreasing superoxide anion production, TBARS levels, the activity of SOD, and hydroxyproline content. The data strongly indicate that increased ROS production and augmented collagen synthesis are elicited by traumatic muscular injury, effects that were significantly decreased by LLLT.

[Effect of reinforcing Qi strength spleen in the expression of bFGF and EGF in treating serious soft tissue injury]

OBJECTIVE

Using the method of bleeding from the orbital vein and lancing to make the animal model of trauma, and to observe the influence of reinforcing Qi strength spleen in the expression of bFGF and EGF in the reparative process of raw surface, in order to explore the possible mechanism of reinforcing Qi strength spleen in promoting the rehabilitation of soft tissue.

METHODS

Forty healthly adult SD rats were made to be traumatic model using the method of bleeding from the orbital vein and lancing. After operation, there were 33 rats survival, which were divided into the reinforcing Qi strength spleen group, the activating blood circulation to dissipate blood stasis group and the model group randomly. The raw surface and ambient normal skin were taken at the 3rd, 7th and 14th days after operation to detect the expression of bFGF and EGF by immunohistochemical method.

RESULTS

At the 3rd, 7th and 14th days after operation, the expression of bFGF and EGF in the tissue of raw surface of the reinforcing Qi strength spleen group and the activating blood circulation to dissipate blood stasis group was obviously higher than that of the model group(P < 0.05). Compared with the activating blood circulation to dissipate blood stasis group, the expression of bFGF and EGF in the tissue of raw surface of the reinforcing Qi strength spleen group was higher (P < 0.05) in the 3rd and 7th day after operation. But in the 14th after operation, there was no significantly difference between reinforcing Qi strength spleen group and activating blood circulation to dissipate blood stasis group.

CONCLUSION

The method of reinforcing Qi strength spleen can efficiently promote the expression of bFGF and EGF in raw surface of serious soft tissue injury.

[Expression of CXC chemokine receptor 4 in muscle satellite cells of muscle injury tissues]

OBJECTIVE

To observe the expressions of CXC chemokine receptor 4 (CXCR4) in muscle satellite cells in situ of normal and cardiotoxin-intoxicated muscle tissues so as to further investigate the molecular mechanism involving in muscle regeneration such as progressing muscular dystrophy (PMD) for seeking the way to cure muscle retrogression.

METHODS

The muscle injured model of 12 C57 male mice was made by injecting cardiotoxin (5 microg per mouse) in left quadriceps femoris, their right quadriceps femoris was used as control without any injection. The histological, immunohistochemical analysis and RT-PCR were done to investigate the expression of CXCR4 in the quadriceps femoris in situ after 1 day, 4 days, 1 week, 2 weeks, 4 weeks and 6 weeks.

RESULTS

HE staining results demonstrated that the muscle tissues experienced the process from muscle injury, repair to regeneration. The result of immunohistochemistry showed that the expressions of CXCR4 in injured muscle tissue were 1955.6 +/- 150.3, 2223.2 +/- 264.3, 2317.6 +/- 178.7, 3066.5 +/- 269.6, 1770.9 +/- 98.7 and 1505.7 +/- 107.1 at 1 day, 4 days, 1 week, 2 weeks, 4 weeks and 6 weeks after injection of cardiotoxin, there was significant difference when compared with normal muscle (640.3 +/- 124.0, P < 0.00 1). The RT-PCR showed that the expressions of CXCR4 mRNA in injured muscle tissue were 0.822 +/- 0.013, 0.882 +/- 0.025, 1.025 +/- 0.028, 1.065 +/- 0.041, 0.837 +/- 0.011 and 0.777 +/- 0.015 at 1 day, 4 days, 1 week, 2 weeks, 4 weeks and 6 weeks after injection of cardiotoxin, there was significant difference when compared with normal muscle (0.349 +/- 0.006, P < 0.001).

CONCLUSION

CXCR4 may be the critical protein in the process of muscle impairment and reparation.

[Expression of laminin 5 in rat skin wounds regulated by recombinant thymosin beta4]

OBJECTIVE

To explore the mechanism of recombinant thymosin beta4 (Tbeta4) accelerating skin wound healing in rats by regulating laminin 5 expression.

METHODS

Two full thickness 8 mm punch wounds were made at the costovertebral angle on dorsal surface of each adult male rats weighing 200-250 g. Sixty rats were randomized into the control group (n = 15) and the experimental group (n = 45), which was subdivided into low, medium and high dose groups (n = 15). Tbeta4 was applied topically at 2, 6, 18 microg in 50 microL PBS for every 12 hours after model making in the experimental group. The identical amounts of phosphate buffered saline was applied in the control group. Wound healing was observed after model making and immunohistochemical observation was conducted 2, 4 and 7 days after operation.

RESULTS

Seven days after operation, wound contracted obviously and most of the wounds connected well with the margin. In the control group, low dose group, medium dose group and high dose group, the wound healing rate were 7.67% +/- 5.46%, 29.01% +/- 7.43%, 26.54% +/- 11.49% and 10.39% +/- 3.96% respectively 2 days after operation; 28.16% +/- 13.76%, 37.99% +/- 13.05%, 42.00% +/- 9.56% and 39.58% +/- 12.74% respectively 4 days after operation; 59.08% +/- 19.02%, 64.15% +/- 17.92%, 77.39% +/- 8.45% and 69.78% +/- 8.45% respectively 7 days after operation. At 2 days after operation, significant differences were notified in healing rats between 3 sub-experimental groups and the control group (P < 0.05). Immunohistochemistry staining showed that there was a little more positive expression of laminin 5 2 days after operation that beneficial to promote the proliferation and differentiation of cell in every group, including positive cells and ECM. But in medium group there was fewer expression, only at the borderline and bottom of the wound, while the expression significantly increased 4 days after operation (P < 0.05) and there was a relative high expression 7 days after operation (P < 0.01).

CONCLUSION

Tbeta4 can inhibit the expression of laminin 5 early, and then up-regulate laminin 5 expression to moderate the reformation of ECM, promote the migration of epidemic cell and accelerate skin wound healing.

[Effects of Shibao Powder on promoting the expression of b-FGF and TGF-beta 1, in the repair of soft tissue injuries]

OBJECTIVE

To study the effects of Shibao Powder on the expression of b-FGF and TGF-beta 1 in granulation tissues of rabbit models with soft tissue injuries, so as to explore mechanism of external Chinese drugs for repairing of soft tissues in molecular levels.

METHODS

The rabbit models were established by classical method of full-thickness skin wounds. After 8% sodium sulfide was used and routine disinfection completed, intra-peritoneal anaesthesia was adopted. The skin was cut to expose gastrocnemius muscle, and imcomplete sharp dissection was made near the tendon insertion. The length of the incision was 0.8 cm and the width was 0.4 cm. The rabbits in the experimental group were treated with spread of Shibao Powder at the wound; the rabbits in clean group were treated with routine dressing changes and disinfection; and the rabbits in the control group were treated with dressing changes only. The granulation tissues in different stages were collected and observed with high power microscope. The expression of Transforming Growth Factor-beta 1 (TGF-beta 1) protein and b-FGF protein in wound tissues were detected using StreptA-ridin-Biotin-Complex (SABC) method.

RESULTS

The results showed that the expression of b-FGF protein had significant differences among 3 groups at the 6th day after trauma (P<0.05). The TGF-beta 1 protein expression also had significant differences among 3 groups at the 10th and 14th days after trauma (P<0.05). At the same time, the growth states of granulation tissues had difference among 3 groups at the same trauma stage, and within the same group among different trauma stages.

CONCLUSION

This experimental study shows that Shibao Powder is effective to promote the repair of soft tissues after trauma by stimulating production of endogenous growth factor from cells in wound.

Origin of immunomodulation after soft tissue trauma: potential involvement of extracellular heat-shock proteins

Severe injury may lead to immunosuppression, multiple organ failure, and death. The aim of the study was to investigate the direct impact of soft tissue destruction on the development of trauma-associated immunomodulation. Hip surgery was considered to represent an isolated soft tissue trauma that allowed for the examination of changes taking place locally at the site of trauma or systemically with regard to monocyte function and leukocyte redistribution. Peripheral blood and wound fluid collected from the drains of 21 patients after hip surgery were analyzed to determine the cellular composition and/or the responsiveness of mononuclear cells (MNCs) to lipopolysaccharide (LPS). Different factors present in the wound fluids were tested for their capacity to modulate the MNC of healthy individuals with regard to cytokine and chemokine secretion. We found that various factors, including heat-shock protein (HSP) 60 and HSP70, were locally released at the site of soft tissue trauma and could be detected in wound fluids. The wound fluid-derived MNC (but not the peripheral blood-derived MNC) showed an impaired capacity to release TNF-alpha after LPS stimulation. Cell-free wound fluid suppressed in healthy individuals the LPS-induced TNF-alpha secretion by MNC. After surgery, granulocytosis was found in peripheral blood and in wound fluids, but monocytopenia was restricted to wound fluids. In parallel, wound fluids induced in healthy individuals the release by MNC of distinct chemokines specific for granulocytes and monocytes. These wound fluid-mediated effects of TNF-alpha suppression and chemokine induction could be mimicked by recombinant human HSP70 and, in part, by HSP60. Thus, tissue-derived factors, such as HSP70 released after injury, suppress monocyte function and, therefore, might favor the development of immunosuppression after severe injury.

Estrogen receptor-alpha predominantly mediates the salutary effects of 17beta-estradiol on splenic macrophages following trauma-hemorrhage

Although 17beta-estradiol administration following trauma-hemorrhage prevents the suppression in splenic macrophage cytokine production, it remains unknown whether the salutary effects are mediated via estrogen receptor (ER)-alpha or ER-beta and which signaling pathways are involved in such 17beta-estradiol effects. Utilizing ER-alpha- or ER-beta-specific agonists, this study examined the role of ER-alpha and ER-beta in 17beta-estradiol-mediated restoration of macrophage cytokine production following trauma-hemorrhage. In addition, since MAPK and NF-kappaB are known to regulate macrophage cytokine production, we also examined the activation of those signaling molecules. Male rats underwent trauma-hemorrhage (mean arterial pressure of 40 mmHg for 90 min) and fluid resuscitation. The ER-alpha agonist propyl pyrazole triol (PPT; 5 microg/kg), the ER-beta agonist diarylpropionitrile (DPN; 5 microg/kg), 17beta-estradiol (50 microg/kg), or vehicle (10% DMSO) was injected subcutaneously during resuscitation. Twenty-four hours thereafter, splenic macrophages were isolated, and their IL-6 and TNF-alpha production and activation of MAPK and NF-kappaB were measured. Macrophage IL-6 and TNF-alpha production and MAPK activation were decreased, whereas NF-kappaB activity was increased, following trauma-hemorrhage. PPT or 17beta-estradiol administration after trauma-hemorrhage normalized those parameters. DPN administration, on the other hand, did not normalize the above parameters. Since PPT but not DPN administration following trauma-hemorrhage was as effective as 17beta-estradiol in preventing the suppression in macrophage cytokine production, it appears that ER-alpha plays the predominant role in mediating the salutary effects of 17beta-estradiol on macrophage cytokine production following trauma-hemorrhage and that such effects are likely mediated via normalization of MAPK but not NF-kappaB signaling pathways.

Young and middle-age associated differences in cytokeratin expression after bone fracture, tissue trauma, and hemorrhage

BACKGROUND

This study examined whether there is any difference in the lung cytokine and cytokeratin 19 levels between young and middle-aged mice after bone fracture and soft-tissue trauma hemorrhage (Fx-TH).

METHODS

Young (6-8 weeks) and middle-aged (12 months) C3H/HeN male mice were subjected to right lower leg fracture, trauma hemorrhage (mean arterial blood pressure to 35 +/- 5 mm Hg for 90 minutes), and resuscitation.

RESULTS

The tumor necrosis factor alpha level in the lung increased significantly at 2 hours after Fx-TH in both young and middle-aged mice, whereas at 24 hours the levels remained significantly higher in middle-aged mice. Interleukin-6 levels increased significantly 24 hours after Fx-TH in both groups, whereas interleukin-10 levels increased only in middle-aged mice at 24 hours under those conditions. Monocyte chemoattractant protein-1 levels increased significantly 2 hours after Fx-TH. The protein and messenger RNA levels of cytokeratin 19 were significantly higher in middle-aged mice compared with young mice after Fx-TH.

CONCLUSION

These results suggest that age influences the lung inflammatory response after Fx-TH.

[The effect of pcDNA3.1-vEGF165 recombined vector on wound healing and the expression of collagen type I, III mRNA in wounded tissue]

OBJECTIVE

To examine the effect of pcDNA3.1-VEGF165 vector to the angiogoiesis, expression of collagen type I and type III mRNA in soft tissue injury model.

METHODS

Thirty two Sprague-Daulay rats,weighted (180 +/- 20) g, were made tissue injury in the bilateral of vertebral region. Round wound (diameter 12 mm) was made by perforex on the back, removed the skin and 2 mm muscle, one side was experimental group by random and the other as control. The wound was done with sodium chloride (0.2 ml) in the control group, with the recombinant VEGF165 vector (0.2 ml, 200 mg) in the experimental group. The wound healing and other general state of health was observed after the operation. The specimens were obtained at 3,5, 7,14 and 30 days after injury. Draw the materials from the rats at the same time, all samples were divided into two parts. one ( > 0.1 g) was conserved in refrigerator at - 80 degrees C, which was extracted total RNA by TRIZOL, design the primer of rat's collagen type I and type III, RT-PCR analysis indicated that collagen type I, III. The other was fixed by 10% formalin. Examine wound healing of local tissue and count it' s MVD by HE staining.

RESULTS

All the rabbits were well alive, no death or infection. Wound healing time was shorter than the control one (14.2, 17.4 d). Inflammatory cell infiltrate, cellula intersitialis, fibroblast, collagen and the density of angiogenesis were more in the experimental group than in the control one. The MVD was significant difference between the two groups at 1, 2 weeks are 63.38 +/- 9.20, 52.72 +/- 7.06 and 76.64 +/- 12.27, 66.84 +/- 9.82 (P < 0.05). The expression of collagen type I , III mRNA was found in the third day, the peak was in the second week and then degression. The collagen type I , III mRNA and beta-actin specificitic belt were found and its initial template volume different, the results was trend of RT-PCR obtained.

CONCLUSIONS

The local application of pcDNA3.1-VEGF165 can enhance the expression of collagen type I, III mRNA, enhance angiogenesis and extra cellular matrix, both of which can shorten healing time of tissue injury.

[Change of nitric oxide in local muscle of crush injury hind-limbs in rats]

OBJECTIVE

To investigate the change of nitric oxide (NO) level in local muscles induced by crushing hind-limbs in rats.

METHODS

The rat experimental model of hind-limb crushing injury was established by crushing the hind limbs of rats with standard weight for 5 hours, thereafter releving the standard weight for another 5 hours. The rats were randomly divided into sham group, crushing group, crushing and injecting aminoguanidine (AG) group, crushing and injecting L-arginine (L-Arg) group. The NOS activity and NO level in local muscles and serum were spectrophotometrically measured, and iNOS and eNOS protein expressions in local muscles were examined by immunohistochemistry. The weight ratio of wet to dry (W/D) of local muscles was measured and the pathologic changes were observed.

RESULTS

The crushing hind-limbs induced serious primary and secondary injuries of local muscles such as rupture and rhadomyolysis of skeletal muscular fibers, interstitial vascular congestion and edema, and marked increase in W/D. The expressions of eNOS and iNOS were upregulated in local muscle in crush group compared with sham group. The NOS activity and NO level in local muscles and serum significantly increased. There was positive relationship between NO level and W/D in local muscles. With the usage of AG and L-arg, the hind-limb injuries seemed alleviated and aggravated, respectively.

CONCLUSION

The crushing hind-limbs of rats elicited the upregulation of eNOS and iNOS protein expression, the enhancement of NOS activity and the excess production of NO, the latter of which was involved in the mediation of secondary pathological changes in local muscles.

Time-course changes in the expression of heme oxygenase-1 in human subcutaneous hemorrhage

To determine the time-course of human subcutaneous hemorrhage, heme oxygenase (HO)-1 expression and macrophage infiltration were observed using an immunohistochemical technique and semiquantitative analysis. The number of immunoreactive cells and the number of all infiltrating cells of each microscopic field were counted, and the ratio of the former to the latter was calculated as the positive cells ratio. An increase in the HO-1-positive cells ratio was observed starting at 3 h after injury, and the maximum ratio was observed 3 days after injury. The pattern of the increase in the macrophage ratio was similar to that of the HO-1-positive cells ratio in the early period after injury. Observation of serial sections revealed that the expression of HO-1 in the cells corresponded to the localization of macrophage. The present results suggest that the determination of HO-1 expression, as derived from macrophages, might be useful for the estimation of the time-course of subcutaneous hemorrhage.

Effect of Vacuum Assisted ClosureR Therapy on early systemic cytokine levels in a swine model

Vacuum Assisted Closure (V.A.C.) Therapy has previously been shown to facilitate healing of wounds. However, the physiological mechanism(s) of this treatment modality and its systemic effects require further investigations. The goal of this porcine study was to investigate the effect of V.A.C. Therapy on the systemic distribution of the inflammatory cytokines interleukin (IL)-6, IL-8, IL-10, and transforming growth factor-beta1. Twelve pigs were each given one full-thickness excisional wound, using electrocautery. Six of the pigs were treated with V.A.C. Therapy and six with saline-moistened gauze. Serum samples were collected immediately after wound creation, and hourly for 4 hours. Samples were analyzed using commercially available enzyme-linked immunosorbent assay kits. During the initial 4 hours of treatment, V.A.C. Therapy resulted in earlier and greater peaking of IL-10 and maintenance of IL-6 levels compared with saline-moistened gauze controls, which showed decreased IL-6 values over the first hour (both at p<0.05). No other treatment-based differences were detected.

[The regulatory effects of arginine on hepatic insulin-like growth factor-1 secretion in rats and its implication]

OBJECTIVE

To explore the regulatory effect of arginine on the secretion of hepatic insulin-like growth factor-1 (IGF-I), and the mechanism of enhancing the immune function by arginine.

METHODS

Wistar rats were randomly divided into normal control (NC), wound control (WC), and wound with arginine (Arg) groups, with 8 rats in each group. The rats in WC and Arg groups were inflicted with soft tissue trauma on the back. The rats in Arg group were fed a diet supplemented with 5% arginine for one week, while those in NC and WC groups were fed with glycine. The serum contents of arginine, ornithine, growth factor (GH), NO and IGF-I were determined 7 days after feeding. T cell proliferation and IGF-I mRNA expression in hepatic tissue were also measured. Meanwhile, the rat hepatocytes were cultured in serum-free medium containing different concentrations of arginine. The supernatant was collected for the determination of IGF-I level.

RESULTS

1). There was no obvious difference of the serum level of arginine and ornithine between NC and WC groups (P > 0.05), but the contents of them were obviously higher in the Arg group compared with other two groups (P < 0.01). 2). No difference in the serum GH level was found among all the groups (P > 0.05), but the serum NO content in WC and Arg groups was significantly lower than that in NC group (P < 0.01), and the serum IGF-I content in WC group decreased obviously compared with that in NC group (P < 0.01). 3). The thymocyte proliferation rate in WC group was also markedly lower than that in NC group (P < 0.01), but that in Arg group was improved compared with WC group (P < 0.01). 4). The expression of hepatic IGF-I mRNA: The relative value of IGF-I mRNA was 1.19 +/- 0.06, 1.08 +/- 0.06 and 1.29 +/- 0.06 in NC, WC and Arg, respectively, while the value in WC was lower than that in NC (P < 0.05) group, and that in Arg group was much higher than that in WC group (P < 0.01). 5). The IGF-I level in the supernatant of cultured hepatocytes: When Arg concentration was 0.0750, 0.7500, 7.5000 mmol/L in the culture medium, the IGF-I level in the supernatant of hepatic cell medi-um was obviously higher than that in the medium without arginine (P < 0.01). Although IGF-I level decreased in the culture medium with arginine in the dose of 37.5000 mmol/L, it was still obviously higher than that in the medium without arginine (P < 0.01).

CONCLUSION

Arginine could also produce the immune enhancing effect by stimulating hepatic IGF-I secretion.

[Aspects of oxygen regimen and metabolism in patients after operative intervention under neuroleptic analgesia]

Result of microsurgical correction of posttraumatic defect of soft tissues depends a lot on anesthesiological support. During the operation the inhibition of energetic status causes the occurrence of oxygentransporting debt, metabolic acidosis develops. Analgosedation, peculiar to anesthesy, promotes an organism defense toward operative trauma of middle severity, causes temporary hypometabolic effect, changed than by oxidantic stress and general adaptive syndrome development.

[Morphological changes of tissues after extensive soft tissue injury]

OBJECTIVE

To study the pathological morphological changes for diagnosing the cause of death of extensive soft tissue injury or crush syndrome.

METHODS

The tissues were stained by HE and IHC.

RESULTS

(1) The Mb positive rate was 60%, 75%, 95% respectively. (2) Both the HSP70 positive rate of hearts and brains were 90%.

CONCLUSION

(1) The animal model of broad soft tissue injury was established. (2) Accumulated the pathological morphological data for diagnosing the cause of death of extensive soft tissue injury or crush syndrome.

Blunt trauma soft-tissue uptake on skeletal scintigraphy

Muscle and soft-tissue uptake have been described numerous times in the literature in patients undergoing Tc-99m methylene diphosphonate skeletal scintigraphy following trauma. Many of these traumas range from electrical burns, intramuscular injections, sports-related trauma, and overexercising, to actual physical damage resulting in superficial bruising and skin discoloration. In this case the patient presented with continuing low back pain after falling down some stairs. Although the scan was essentially normal for bony trauma, subtle soft-tissue uptake was detected that was enhanced with the addition of single photon emission computed tomographic imaging and surface rendering.

Testosterone and estrogen differently effect Th1 and Th2 cytokine release following trauma-haemorrhage

The object of the study was to determine whether male and female sex steroids produce divergent effects on Th1 and Th2 cytokine release following trauma-haemorrhage. Recent studies indicate that androgens are responsible for the depressed splenocyte Th1 cytokine release in males following trauma-haemorrhage. In contrast, female mice maintain their Th1 cytokine release capacity following trauma-haemorrhage. Nonetheless, the effect of male and female sex steroids on Th1 and Th2 cytokine release following trauma-haemorrhage remains unknown. Male C3H/HeN mice were castrated and treated with pellets containing either vehicle, 5alpha-dihydrotestosterone (DHT), 17beta-estradiol (estradiol), or a combination of both steroid hormones, for 14 days prior to soft-tissue trauma (i.e. laparotomy) and haemorrhagic shock (35+/-5 mmHg for 90 min followed by adequate fluid resuscitation) or sham operation. Untreated male and female mice, as well as DHT treated female mice, served as control groups. Twenty-four hours later the animals were sacrificed, plasma obtained and splenocytes harvested. Plasma DHT and estradiol levels in treated animals were comparable with intact male and female mice, respectively. A significant depression of splenocyte Th1 cytokines, i.e. IL-2, IFN-gamma, was observed in DHT treated castrated animals, DHT treated females, and untreated males following trauma-haemorrhage, as opposed to maintained Th1 cytokine release in estradiol treated and estradiol/DHT treated castrated animals and females. The release of the anti-inflammatory cytokine IL-10 was markedly increased in DHT treated mice and males subjected to trauma-haemorrhage compared to shams, but decreased in estrogen treated mice and females under such conditions. These results suggest that male and female sex steroids differentially affect the release of Th1 and Th2 cytokines following trauma-haemorrhage and should be further studied for their potential to modulate splenocyte function in trauma victims.

Skeletal troponin-I release in orthopedic and soft tissue injuries

The skeletal isoform of troponin-I (sTnI) is a myofibrillar protein highly specific for myoskeletal injury. We used an indirect immunoenzymometric assay method with high analytical sensitivity to measure sTnI in patients with soft-tissue injury and in orthopedic patients. We assessed 20 soft-tissue injury patients and 16 orthopedic patients for sTnI, cardiac troponin-I (cTnI), creatine kinase (CK), myoglobin, and elastase within 24h of injury, in comparison with 17 control subjects. The mean (SD) ng/ml value for sTnI was higher in orthopedic patients (15.25 +/- 2.4) and in soft-tissue injury patients (10.41 +/- 1.8) than that in controls (2.5 +/- 0.9) P < 0.001, P < 0.05 respectively. Cardiac TnI was not detectable in any subjects (below the assay detectable limit of 0.3ng/ml). CK was significantly higher in orthopedic patients than in controls (P < 0.005) and myoglobin and elastase were not significantly changed in patients samples. The assay appeared to be suitable as a supplementary tool of reliability and relevance, for the study, identification, and diagnosis of skeletal muscle specific injuries in humans.

Expression of vascular endothelial growth factor during the early stage of maxillofacial blast injury

OBJECTIVE

To determine the expression and the change of vascular endothelial growth factor (VEGF) and its acceptor KDR during the early stage of maxillofacial blast injury. To evaluate the effect of VEGF on traumatic wound healing.

METHODS

The rabbit model of maxillofacial blast injury was made by KTY-04 blasting cap. The expression of VEGF and KDR in wound tissue was determined by ABC immunohistochemistry of 6 hours, 1 day, 2 days, 3 days, 5 days, and 7 days after injury. The results were compared with preinjury groups.

RESULTS

In the wound tissue of the maxillofacial blast injury, the expression of VEGF rose steadily during the first week after the injury. Compared with normal tissue, the wound tissue showed differences by the first day after injury, and showed significant differences by the third day (P < 0.01). The differences reached a peak at the seventh day after injury. The expression of KDR showed no difference within 3 days after injury when compared to normal tissue. Between 5 and 7 days after injury, the protein was more strongly expressed.

CONCLUSION

The stage of the VEGF expression at the maxillofacial blast injury site is similar to the angiopoietic stage during would healing, and KDR expression also occurs during that period. VEGF takes part in angiogenic cascades of traumatic wound healing and is produced as an auxiliary action to the regeneration of blood vessels.

Assessment of tissue oxygenation

A continuous supply of oxygen to all tissues is necessary for the efficient production of ATP, and this supply is considered sufficient when aerobic metabolism is maintained. Nonhealing wounds, necrotizing infections, radiation-induced necrosis, crush injury, decompression illness, and CO poisoning all exhibit impaired tissue oxygenation. The need for efficacy of HBO therapy in such conditions is in part determined by the prevailing state of tissue oxygen supply and demand. The methods currently available or under development for assessing the adequacy of tissue oxygenation include blood gas analysis, transcutaneous oxygen measurement, gastric tonometry, pulse oximetry, near-infrared spectroscopy, functional MR imaging, MR spectroscopy, electron paramagnetic resonance, positron emission tomography, and single photon emission computed tomography. The clinical and experimental applications of these methods are discussed and emphasis is placed on their role in hyperbaric medicine.

Effects of halothane, ketamine and nitrous oxide on dynorphin mRNA expression in dorsal horn neurons after peripheral tissue injury

Peripheral tissue injury is known to induce changes in gene expression in spinal neurons and result in a prolonged alteration of neuronal excitability. The purpose of this study was to examine the effect of halothane on the dynorphin mRNA expression in spinal dorsal horn neurons after peripheral tissue injury by formalin injection and compare the effect to that of ketamine and nitrous oxide. Male Sprague-Dawley rats were anesthetized with 1.3% halothane, ketamine, or 67% nitrous oxide. Fifteen minutes after induction of anesthesia, rats received an intraplantar injection of 150 microliter 5% formalin into the unilateral hindpaw. General anesthesia was maintained for 8 h, and the expression of preprodynorphin (PPD) and preproenkephalin (PPE) mRNAs in the spinal cord (L4-5) was examined by in situ hybridization. The degree of edema of the inflamed foot was not different among the three anesthesia groups and the control (no anesthesia) group. The number of neurons expressing PPD mRNA dramatically increased in the superficial dorsal horn ipsilateral to the formalin injection in the control group compared to the contralateral side. The number of neurons labeled for PPD mRNA in the halothane group was significantly less than the control group. However, the number of PPD mRNA-expressing neurons in both the ketamine and nitrous oxide groups was significantly less than the halothane group. The expression of PPE mRNA was not influenced by these anesthetics. These data indicate that the suppressive effect of halothane anesthesia on the induction of PPD mRNA in dorsal horn neurons was smaller than those of ketamine and nitrous oxide, suggesting an important supplemental way to control the alteration of gene expression in spinal neurons for clinical settings.

Severe depression of host immune functions following closed-bone fracture, soft-tissue trauma, and hemorrhagic shock

OBJECTIVE

To determine the contribution of soft-tissue trauma plus hemorrhage, bone fracture and hemorrhage, as well as the contribution of bone fracture, soft-tissue trauma and hemorrhage on host immune function.

SUBJECTS

Adult male mice (n = 6/group).

DESIGN

Prospective, randomized, controlled study.

SETTING

Animal laboratory at a university-affiliated hospital.

INTERVENTIONS

Closed-bone fracture (right lower leg; external fixation) and/or soft-tissue trauma (2.5-cm midline laparotomy, closed in two layers) were induced before hemorrhagic shock (mean arterial blood pressure of 35 +/- 5 (SEM) mm Hg for 90 mins, followed by fluid resuscitation) in male C3H/HeN mice and the animals were killed at 72 hrs after initiation of the experiment.

MEASUREMENTS AND MAIN RESULTS

Splenocyte interleukin (IL)-2 and IL-3 release capacity, as well as splenic and peritoneal macrophage IL-1 and IL-6 release capacity were determined. Different traumatic insults, i.e., bone fracture or soft-tissue trauma in conjunction with hemorrhage, produced comparable immune depression. More significant depression of splenocyte IL-2 and IL-3 release capacity as well as macrophage IL-1 and IL-6 release capacity occurred with the combined insult (i.e., bone fracture/soft-tissue injury and hemorrhage) than after bone injury or tissue trauma alone with hemorrhage.

CONCLUSIONS

The combination of closed-bone fracture and soft-tissue trauma before hemorrhage leads to even more compromised immunity than either soft-tissue trauma or closed-bone fracture along with hemorrhage. The markedly depressed immune function following bone injury, soft-tissue trauma, and hemorrhagic shock may contribute to the increased susceptibility of severely injured patients to sepsis and the ensuing multiple organ failure in the clinical situation.