What Happened if Various Kinds of Postconditioning Working on the Preconditioned Ischemic Skin Flaps

Objective: Ischemic pre-conditioning and post-conditioning are useful manipulations to reduce the undesirable effects of ischemia-reperfusion skin flap each. But the impact of post-conditioning on the pre-conditioning skin flap is not manifested. Here we investigated the influence of ischemic post-conditioning in a preconditioned axial pattern skin flap model.Method: We used the skin flap in 40 rabbits and divided them into 5 groups randomly. At first we induced the ischemic pre-conditioning of the flap which was applied by 2 periods of 15 minutes of ischemia/15 minutes of reperfusion cycle. Next post-conditioning was performed by 6 cycles of 10 seconds of repeated ischemia/reperfusion periods at different times of just after the reperfusion,5 minutes after the reperfusion,10 minutes after the reperfusion. The animals were allocated into 5 groups: group 1 (Ischemia Group); group 2: (Pre-conditioning Group); group 3: (Pre-conditioning+ Post-conditioning Group); group 4 (Pre-conditioning+ Post-conditioning 5 minutes later Group); group5 (Pre-conditioning+ Post-conditioning 10 minutes later). The neutrophil count was assessed with histologic analysis before the dissection of the skin flap. Flap viability was assessed 1 week after the operation, and surviving flap area was recorded as a percentage of the whole flap area. LSD test was used for statistical analysis among different groups to evaluate the effects of ischemic pre-conditioning against ischemia.Result: Among the varying groups, the neutrophil count varied: Group 1 was50.12±5.91; Group 2, 30.00±2.00, and Group 3, 18.87±3; Group 4, 22.50±1.92; Group 5, 30.12±1.88.The mean± SD surviving areas of the flaps for groups 1, 2, 3, 4 and 5 were 31.76±4.59, 51.26±3.24,82.18±5.28,66.85±3.87 and 51.13±2.90 respectively. Spearman correlation analysis shows an increase relation between neutrophil count and flap survival rate in the different groups (P <0.05).Conclusion: Ischemic post-conditioning has protective effect on ischemic preconditioned skin flaps, but the post-conditioning should be performed within 5 minutes after the end of ischemia.     

间歇封闭负压改善皮瓣术后静脉回流障碍的临床研究

目的：评价间歇封闭负压技术在治疗皮瓣术后静脉回流障碍中的应用价值。方法：总结我科自2010 年8 月至2014 年10 月 治疗的30 例皮瓣移植术后静脉回流障碍的病例,其中男19 例,女11 例,年龄25～65 岁,平均38 岁。所有皮瓣均表现为不同程 度的青紫、肿胀、水疱、皮温低、充盈反应迟缓或创缘出血（淤血）等,且淤斑的面积大于皮瓣面积的20%。治疗组给予间歇封闭负 压治疗（120 mmHg 负压,治疗3 min,间歇2 min）。对照组采用常规换药治疗。两组均隔日换药,创面摄影并利用图像分析软件测 量瘀斑面积。比较两组皮瓣淤血高峰时间、皮瓣血运恢复时间、远端坏死率及二次手术率。结果：间歇负压治疗组皮瓣淤血高峰时 间（2.7± 0.82 d）小于对照组（4.5± 1.08 d）（P<0.05）;治疗组皮瓣血运恢复时间（10.8± 2.15 d）也小于对照组（15.9± 2.85 d）（P<0. 05）。此外,治疗组皮瓣远端坏死率（13.3%, 2/15）显著低于对照组（60.0%, 9/15）（P<0.05）。结论：应用间歇封闭负压技术治疗皮瓣 术后静脉回流障碍效果优于常规治疗。     

The Effect of Local Application of Natural Hirudin on Random Pattern Skin Flap Microcirculation in a Porcine Model

The aim of this study was to investigate the effect of local administration of hirudin in improving random pattern skin flap microcirculation in a porcine model. Five Chinese minipigs were used and six dorsal random pattern skin flaps were elevated in each animal (4 × 14 cm). All flaps (n = 30) were assigned to experimental (n = 10), control (n = 10), and sham (n = 10) groups. Flap edema measurement showed that edema in experimental flaps was more severe (P < 0.05) than either control or sham flaps. Local blood flow detection showed an increased image signal of blood flow in experimental flaps instead of an obvious avascular area in control and sham flaps. The survival area was significantly greater in experimental group (67.6 ± 2.1 %) as compared to control (45.2 ± 1.4 %) or sham (48.3 ± 1.1 %) group (P < 0.05). Our data showed that local administration of hirudin can significantly improve random pattern skin flap microcirculation in over dimensioned random pattern skin flaps in a porcine model.     

The role of the large superficial vein in survival of proximally based versus distally based sural veno-neuro-fasciocutaneous flaps in a rabbit model

A sural veno-neuro-fasciocutaneous flap in the New Zealand White rabbit was developed, and the role of the large subcutaneous lesser saphenous vein was investigated in proximally based versus distally based flaps. Retrograde dye injection showed that the lesser saphenous vein in rabbits has many valves with strong resistance against reflux. Twenty rabbits were randomly allocated into four groups of 10 flaps each. Group I consisted of proximally based flaps with the lesser saphenous vein intact (outflow) in the veno-neuro-adipofascial pedicle. Group II also consisted of proximally based flaps but the lesser saphenous vein was ligated at 1 cm proximal to the pedicle. Group III consisted of distally based flaps with the lesser saphenous vein intact (inflow) in the veno-neuro-adipofascial pedicle. Group IV also consisted of distally based flaps, but the lesser saphenous vein was ligated at 1 cm distal to the pedicle. The results showed that the mean flap survival area in group I (88.8 percent) was statistically higher than that in group II (62.6 percent, p < 0.001), and was higher in group IV (55.5 percent) than in group III (22.7 percent, p < 0.01). However, group II and group IV had no significant difference (p > 0.05). This experiment demonstrated that flap viability is determined by its intrinsic vascularization, both arterial and venous. The large superficial subcutaneous vein has a positive role (venous outflow) in proximally based flaps but a negative role (venous inflow) in distally based flaps. If the effect of the large subcutaneous vein is excluded, distally based flaps are not inherently inferior to proximally based flaps.     

The therapeutic effect of silibinin against 5-fluorouracil-induced ovarian toxicity in rats

5-Fluorouracil (5-FU) is a fluoropyrimidine group antineoplastic drug with antimetabolite properties and ovotoxicity is one of the most important side effects. Silibinin (SLB) is a natural compound that is used worldwide and stands out with its antioxidant and anti-inflammatory properties. The aim of this study was to evaluate the therapeutic effect of SLB in 5-FU-induced ovototoxicity using biochemical and histological analysis. This study was carried out in five main groups containing six rats in each group: control, SLB (5 mg/kg), 5-FU (100 mg/kg), 5-FU + SLB (2.5 mg/kg), and 5-FU + SLB (5 mg/kg). The levels of ovarian malondialdehyde (MDA), total oxidant status (TOS), total antioxidant status (TAS), superoxide dismutase (SOD), catalase (CAT), 8-hydroxy-2′-deoxyguanosine (8-OHdG), tumor necrosis factor-alpha (TNF-α), myeloperoxidase (MPO), and caspase-3 were determined using spectrophotometric methods. Hematoxylin and eosin staining method was employed for histopathological examination. MDA, TOS, 8-OHdG, TNF-α, MPO, and caspase-3 levels in 5-FU group were significantly increased compared with the control group, while the levels of TAS, SOD, and CAT were decreased (p < 0.05). SLB treatments statistically significantly restored this damage in a dose-dependent manner (p < 0.05). Although vascular congestion, edema, hemorrhage, follicular degeneration, and leukocyte infiltration were significantly higher in the 5-FU group compared with the control group, SLB treatments also statistically significantly restored these damages (p < 0.05). In conclusion, SLB has a therapeutic effect on the ovarian damage induced by 5-FU via decreasing the levels of oxidative stress, inflammation, and apoptosis. It may be helpful to consider the usefulness of SLB as an adjuvant therapy to counteract the side effects of chemotherapy.     

The effect of low-molecular-weight heparin in the survival of a rabbit congested skin flap

Swelling and congestion of flaps are frequently seen postoperatively and can cause unexpected necrosis. According to previous reports, venous thrombosis seems to be a more frequent problem than arterial occlusion in both experimental and clinical surgery. Few satisfactory venous trauma models exist, and reports on experimental venous thrombosis are rare. The object of this study was to create a rabbit venous occlusion flap model and to evaluate the effect of low-molecular-weight heparin on this flap. Eight New Zealand rabbits were used in the pilot study, in which the ideal congested flap was investigated using a flap pedicle based on the central auricular artery with a skin pedicle 0, 1, 2, or 3 cm wide. The flap (3 x 6 cm) was designed on the central part of the left ear, and the central auricular vein and nerve, the former for venous return, were cut out at the base of the flap. The flaps with skin pedicles 0, 1, 2, or 3 cm wide showed mean necrosis length of 60.0, 9.3, 4.2, and 0.0 mm, respectively. The flaps with skin pedicles 0, 1, 2, or 3 cm wide showed mean necrosis of 100, 15.5, 7, and 0 percent, respectively. Therefore, the flap, based on a 1-cm-wide skin pedicle and the central auricular artery, was selected as an optimal congested flap model showing 15.5 percent necrosis. The congested flap was then elevated on the left ear of another 10 rabbits. Subcutaneous low-molecular-weight heparin (320 IU/kg) was administered immediately after surgery to five of the rabbits (the low-molecular-weight heparin group), and the remaining five were used as a control group. Fluorescein was injected 15 minutes after surgery to evaluate the circulatory territory of the flap, and the circulatory territory was measured 5 minutes after injection. The flaps were assessed 7 days after surgery by angiography, histology, and clinical findings. The circulatory territory was significantly greater in the low-molecular-weight heparin group (mean +/- SD, 39.2 +/- 3.0 mm) than the control group (mean +/- SD, 48.0 +/- 1.0 mm) (p < 0.001) assessed 7 days after surgery. The longest flap survival length in group A and group B ranged from 40 to 55 mm (mean +/- SD. 49.4 +/- 5.6 mm) and complete survival (mean +/- SD, 60.0 +/- 0.0 mm). The improvement in survival was statistically significant for group B compared with group A (p < 0.015). Histologic evaluation revealed moderate to severe venous congestion and inflammation in the control group, whereas there were minimal changes in the low-molecular-weight heparin group. Angiography of the flap revealed obvious venous occlusion in the periphery in the control group compared with the low-molecular-weight heparin group. The authors conclude that subcutaneous administration of low-molecular-weight heparin has a great potential to improve the survival length of a congested flap without major complications.     

Improved dorsal random-pattern skin flap survival in rats with a topically applied combination of nonivamide and nicoboxil

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.     

Influence of Selenium on Hepatic Mitochondrial Antioxidant Capacity in Ducklings Intoxicated with Aflatoxin B<Subscript>1</Subscript>

The aim of the study was to investigate the effect of selenium on hepatic mitochondrial antioxidant capacity in ducklings administrated with aflatoxin B₁ (AFB₁). Ninety 7-day-old ducklings were randomly divided into three groups (groups I–III). Group I was used as a blank control. Group II was administered with AFB₁ (0.1 mg/kg body weight). Group III was administered with AFB₁ (0.1 mg/kg body weight) plus selenium (sodium selenite, 1 mg/kg body weight). All treatments were given once daily for 21 days. The results showed that the activities of mitochondrial superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), and glutathione reductase (GR) in group II ducklings significantly decreased when compared with group I (P < 0.01). Furthermore, the content of hepatic mitochondrial malondialdehyde (MDA) significantly increased (P < 0.01). However, the activities of hepatic mitochondrial SOD, CAT, GSH-Px, and GR in group III ducklings significantly increased when compared with group II (P < 0.05). In addition, the content of hepatic mitochondrial MDA significantly decreased (P < 0.01). These results revealed that AFB₁ significantly induced hepatic mitochondrial antioxidant dysfunction. However, sodium selenite could significantly ameliorate the negative effect induced by AFB₁.     

Breast Reconstruction with the free TRAM or DIEP flap: patient selection,choice of flap,and outcome

Recent reports of breast reconstruction with the deep inferior epigastric perforator (DIEP) flap indicate increased fat necrosis and venous congestion as compared with the free transverse rectus abdominis muscle (TRAM) flap. Although the benefits of the DIEP flap regarding the abdominal wall are well documented, its reconstructive advantage remains uncertain. The main objective of this study was to address selection criteria for the free TRAM and DIEP flaps on the basis of patient characteristics and vascular anatomy of the flap that might minimize flap morbidity. A total of 163 free TRAM or DIEP flap breast reconstructions were performed on 135 women between 1997 and 2000. Four levels of muscle sparing related to the rectus abdominis muscle were used. The free TRAM flap was performed on 118 women, of whom 93 were unilateral and 25 were bilateral, totaling 143 flaps. The DIEP flap procedure was performed on 17 women, of whom 14 were unilateral and three were bilateral, totaling 20 flaps. Morbidities related to the 143 free TRAM flaps included return to the operating room for 11 flaps (7.7 percent), total necrosis in five flaps (3.5 percent), mild fat necrosis in 14 flaps (9.8 percent), mild venous congestion in two flaps (1.4 percent), and lower abdominal bulge in eight women (6.8 percent). Partial flap necrosis did not occur. Morbidities related to the 20 DIEP flaps included return to the operating room for three flaps (15 percent), total necrosis in one flap (5 percent), and mild fat necrosis in two flaps (10 percent). Partial flap necrosis, venous congestion, and a lower abdominal bulge were not observed. Selection of the free TRAM or DIEP flap should be made on the basis of patient weight, quantity of abdominal fat, and breast volume requirement, and on the number, caliber, and location of the perforating vessels. Occurrence of venous congestion and total flap loss in the free TRAM and DIEP flaps appears to be independent of the patient age, weight, degree of muscle sparing, and tobacco use. The occurrence of fat necrosis is related to patient weight (p < 0.001) but not related to patient age or preservation of the rectus abdominis muscle. The ability to perform a sit-up is related to patient weight (p < 0.001) and patient age (p < 0.001) but not related to preservation of the muscle or intercostal nerves. The incidence of lower abdominal bulge is reduced after DIEP flap reconstruction (p < 0.001). The DIEP flap can be an excellent option for properly selected women.     

Effect of Selenium Supplementation on Lipid Peroxidation,Antioxidant Enzymes,and Lactate Levels in Rats Immediately After Acute Swimming Exercise

The present study aims to evaluate the effect of selenium supplementation on lipid peroxidation and lactate levels in rats subjected to acute swimming exercise. Thirty-two adult male rats of Sprague–Dawley type were divided into four groups. Group 1, control; group 2, selenium-supplemented; group 3, swimming control; group 4, selenium-supplemented swimming group. The animals in groups 2 and 4 were supplemented with (i.p.) 6 mg/kg/day sodium selenite for 4 weeks. The blood samples taken from the animals by decapitation method were analyzed in terms of erythrocyte-reduced glutathione (GSH), serum glutathione peroxidase (GPx) and superoxide dismutase (SOD), and plasma malondialdehyde (MDA) and lactate using the colorimetric method, and serum selenium values using an atomic emission device. In the study, the highest MDA and lactate values were found in group 3, while the highest GSH, GPx and SOD values were obtained in group 4 (p < 0,001). Group 2 had the highest and group 3 had the lowest selenium levels (p < 0,001). Results of the study indicate that the increase in free radical production and lactate levels due to acute swimming exercise in rats might be offset by selenium supplementation. Selenium supplementation may be important in that it supports the antioxidant system in physical activity.     

The effect of autologous endothelial progenitor cell transplantation combined with extracorporeal shock-wave therapy on ischemic skin flaps in rats

BackgroundEndothelial progenitor cells (EPCs) have been used to revascularize ischemic tissues, but only limited effect can be achieved. Extracorporeal shock-wave therapy (ESWT) is a promising angiogenic strategy. We hypothesized that EPC transplantation combined with ESWT would greatly benefit the survival of ischemic skin flaps.MethodsSixty-four male Sprague-Dawley rats were divided into 4 groups (n = 16 in each group): group 1 (serving as sham control), group 2 (treated with subcutaneous EPC implantation, 1.0 × 10⁶ cells), group 3 (treated with ESWT, 300 impulses at 0.10 mJ/mm²) and group 4 (treated with EPCs implantation combined with ESWT). Ischemic skin flaps were made on the backs of rats and treated accordingly. Blood flow of skin flaps was measured periodically after operation, and flap survival rates were compared. Tissue samples were harvested at 2 weeks postoperatively from each group.ResultsThe survival rate of skin flaps in group 4 was 87.5 ± 10.23%, which was statistically significantly higher than other groups. Histologic examination showed that the capillary density was higher in the dual-treatment group than in the two single-treatment groups. Compared with groups 2 and 3, blood perfusion increased significantly in group 4. A drastic increase of vWF+ cells was observed in the ischemic skin flaps on immunofluorescence staining in group 4. The expressions of chemotactic factors and angiogenic factors were higher in group 4.ConclusionsCombined treatment with EPCs and ESWT is superior to either EPCs or ESWT alone in improving the survival of ischemic skin flaps in rats.     

Island rat groin flaps with twisted pedicles

Clinical attempts are made to avoid rotating a flap and twisting the pedicle for fear of perfusion compromise. Torsion of an island rat groin flap pedicle is not a well-recognized experimental entity. The authors describe the results of island flap rotation with pedicle twisting in the rat groin flap model. Forty male Wistar rats were randomly divided into four groups of 10 animals each. In each group, bilateral groin flaps were elevated; one flap was sutured in place without rotation and the contralateral flap was subjected to 180, 270, 360, or 720 degrees of rotation. Blood flow within the flaps was assessed by laser Doppler flowmetry, and flap edema and necrosis were determined 10 days postoperatively. No differences were noted between control flaps and those subjected to 180 and 270 degrees of rotation. Although flaps subjected to 360 degrees of rotation demonstrated a large amount of postoperative edema and congestion of the subcutaneous tissue with some histologic changes, all flaps in this group survived. Measured flap weights at death were different from those of controls. All flaps subjected to 720 degrees of rotation underwent ischemic necrosis. Because of the differences between human skin architecture and rat skin architecture it cannot be concluded that similar results would be observed in any human skin flap. There might be three important points arising from this study of unknowingly twisted island groin flap pedicles in the rat model: (1) twisting of less than 360 degrees has no effect on flap survival; (2) twisting of 720 degrees is always associated with skin flap necrosis; (3) twisting of 360 degrees, although associated with some changes, does not cause skin flap necrosis.     

Effect of hyperbaric oxygen and medicinal leeching on survival of axial skin flaps subjected to total venous occlusion

This study evaluates the effect of hyperbaric oxygen and medicinal leeching on axial skin flaps subjected to total venous occlusion. Axial epigastric skin flaps (3 x 6 cm) were elevated on their vascular pedicles in 40 male Wistar rats. Total venous occlusion was achieved by division of all veins draining the skin flap. Arterial inflow was left intact. Animals were randomly assigned to one of five groups: sham (n = 8); control, total venous occlusion only (n = 8); occlusion with hyperbaric oxygen (n = 8); occlusion with leeching (n = 8); occlusion with leeching and hyperbaric oxygen (n = 8). The hyperbaric oxygen protocol consisted of 90-minute treatments, twice daily, with 100% O2 at 2.5 atmospheres absolute for 4 days. The leeching protocol consisted of placing medicinal leeches on the congested flaps for 15 minutes, once daily, for 4 days. Laser Doppler measurements of flap perfusion were recorded preoperatively, postoperatively, and on postoperative days 1 and 3. The percentage of flap necrosis was evaluated on postoperative day 3. Mean percentage necrosis and mean laser Doppler readings were compared between both groups. The flaps in the sham group demonstrated 99 percent survival, whereas the flaps in the occlusion-only group demonstrated 100 percent necrosis. The flaps in the occlusion with oxygen, the occlusion with leeching, and the occlusion with oxygen and leeching groups demonstrated 1, 25, and 67 percent survival, respectively. Sham laser Doppler readings remained within normal limits. Laser Doppler readings in the occlusion-only and the occlusion with oxygen groups decreased to negligible levels on postoperative day 1, and on postoperative day 3 no perfusion was demonstrated. In both the occlusion with leeching and the occlusion with leeching and oxygen groups, there was also a significant decrease in laser Doppler measurements after surgery, but perfusion remained stable throughout the remainder of the study. This study demonstrates that hyperbaric oxygen alone is not an effective treatment for skin flaps compromised by total venous occlusion. The combination of leeching and hyperbaric oxygen treatment of total venous occlusion results in a significant increase in flap survival above that found with leeching alone. It appears that hyperbaric oxygen is effective because of the venous outflow provided by leeching as demonstrated by laser Doppler flow readings.     

Ischemia-reperfusion injury of adipofascial tissue: an experimental study evaluating early histologic and biochemical alterations in rats

Fat necrosis remains a serious complication in reconstructive flaps. In clinical setting, it is well known that fat tissue is more susceptible to ischemic events. We aimed to evaluate early histological and biochemical changes of adipofascial tissue in an experimental model. An epigastric flap model in rats was used to evaluate the effect of ischemia-reperfusion (I-R) injury on adipofascial tissue. Two groups of animals (one with ischemia alone and other ischemia-reperfusion group) were used to evaluate the degree of histological edema, congestion and extravascular bleeding, and early biochemical alterations within the adipofascial flaps. The biochemical parameters included glutathione (GSH) and malondialdehyde (MDA). In each group, contralateral groin subcutaneous adipose tissue served as control. These evaluations were compared to normal unmanipulated, contralateral abdominal subcutaneous adipose tissue. The ischemia-reperfused flap group showed histologically significantly much edema congestion and bleeding than the control groups (P<.0001). The control group showed less edema in fat tissue than the ischemia-alone group (P<.05). All of the flaps in the ischemia-only group showed significantly less bleeding and edema than I-R group (P<.001). The ratio of MDA/GSH was 33 in control, 37 in ischemia alone, and 82 in ischemia-reperfusion groups, respectively. This study confirms that significant histologic and biochemical alteration occurs after ischemia and ischemia-reperfusion events in adipose tissue. Marked drop in adipose tissue antioxidant levels after I-R suggested that preemptive measures to this decrease should be undertaken in clinical settings.     

Effects of diode laser therapy on the acellular dermal matrix

Acellular dermal matrix (ADM) was subcutaneously implanted into calvarian skin of male Wistar rats (n = 40). Low-level laser (λ 685 nm, 4 J/cm²) was locally applied in experimental group (n = 20) above the skin flap. Grafts were harvested at 1, 3, 7 and 14 days after surgery and underwent histological analyses. In treated animals, the extent of edema and the number of inflammatory cells were reduced (P < 0.05). The amount of collagen in graft treated with low-level laser were significantly higher than those of controls (P < 0.05) and were statistically more prominent on the 14th day after surgery. The mean count of fibroblasts was significantly higher in the low-laser therapy group within the 3rd day, showing a marked influx of fibroblasts into area. In conclusion, wound healing of the ADM appear to be positively affected by laser therapy.     

Pharmacologic enhancement of rat skin flap survival with topical oleic acid

This study was instituted to investigate in a rat model the effect of topical coadministration of the penetration enhancer oleic acid (10% by volume) and RIMSO-50 (medical grade dimethyl sulfoxide, 50% by volume) on rat skin flap survival. A rectangular abdominal skin flap (2.5 x 3 cm) was surgically elevated over the left abdomen in 40 nude rats. The vein of the flap's neurovascular pedicle was occluded by placement of a microvascular clip, and the flap was resutured with 4-0 Prolene to its adjacent skin. At the end of 8 hours, the distal edge of the flap was reincised to gain access to the clips and the clips were removed. After resuturing of the flap's distal edge to its adjacent skin, the 40 flaps were randomly divided into four groups. Group 1 (control) flaps were treated with 5 g of saline, group 2 (dimethyl sulfoxide) flaps were treated with 2.7 g of dimethyl sulfoxide (50% by volume), group 3 flaps (oleic acid) were topically treated with 0.45 g of oleic acid (10% by volume), and group 4 (dimethyl sulfoxide plus oleic acid) flaps were treated with a mixture of 0.45 g of oleic acid (10% by volume) and 2.7 g of dimethyl sulfoxide (50% by volume) diluted in saline. Each flap was topically treated with 5 ml of drug-soaked gauze for 1 hour immediately after clip removal to attenuate reperfusion injury. Thereafter, drug was applied topically once daily for 4 more days. Digital photographs of each flap were then taken on day 6 and the flaps were then harvested. The percentage of skin survival in each flap was determined by computerized morphometry and planimetry. The mean surviving area of group 3 (oleic acid-treated flaps) was 23.60 +/- 4.19 percent and was statistically higher than that in group 1 (control, saline-treated flaps) at 7.20 +/- 2.56 percent. The mean surviving area of group 2 (dimethyl sulfoxide-treated flaps) at 18.00 +/- 5.23 percent and group 4 (oleic acid- and dimethyl sulfoxide-treated flaps) at 9.90 +/- 3.44 percent did not achieve statistically higher mean surviving areas than controls. A topical solution of oleic acid (10% by volume) caused a statistically significant increase in the survival of rat abdominal skin flaps relative to controls. Dimethyl sulfoxide and the two experimental drugs together did not increase the percentage of flap survival when given as a single 5-ml dose released from a surgical sponge at reperfusion for 1 hour and then daily for a total of 5 days. The reasons for the lack of response are unknown but may have included the technical difficulty of delivering an adequate dose of dimethyl sulfoxide topically and immiscibility between dimethyl sulfoxide and oleic acid. Further studies may be warranted.     

A single dose of carbon monoxide intraperitoneal administration protects rat intestine from injury induced by lipopolysaccharide

Treatment with inhaled carbon monoxide (CO) has been shown to ameliorate intestinal injury induced by lipopolysaccharide (LPS) or ischemia-reperfusion in experimental animals. We hypothesized that CO intraperitoneal administration (i.p) might provide similar protection against inhaled gas. In the present study, 1 h after intravenously receiving 5 mg/kg LPS, rats were exposed to either room air or 2 ml/kg of 250 ppm CO i.p for 1, 3, and 6 h. Intestinal tissues were collected to determine the levels of platelet activator factor (PAF), intercellular adhesion molecule-1 (ICAM-1), interlukin-10 (IL-10), maleic dialdehyde (MDA), cell apoptotic rate and the phosphorylated p38 mitogen activated protein kinase (MAPK), as well as myeloperoxidase (MPO) and superoxide dismutase (SOD) activity. After CO i.p, the increase of PAF, ICAM-1, MDA, MPO, and cell apoptosis rate induced by LPS was markedly reduced (P < 0.05 or 0.01), while the decrease of IL-10 and SOD was significantly increased (P < 0.05). Western blotting showed that the effects of CO i.p were mediated by p38 MAPK pathway. Thus, the results of our study show that CO i.p exerts potent protection against LPS induced injury to the intestine via anti-oxidant, anti-inflammation and anti-apoptosis, which may involve the p38 MAPK pathway.     

Cryopreservation of composite tissues and transplantation: preliminary studies

Despite advances in cryobiology, the reliable cryopreservation of complex tissues has not yet been achieved. This study evaluates the viability of cryopreserved composite flaps and demonstrates the feasibility of their transplantation. Epigastric flaps were harvested from male Lewis rats. 1.5 M dimethyl sulfoxide (Me₂SO) was used as the initial cryoprotectant agent (CPA). Samples were frozen at controlled rate to −140 °C and transferred to liquid nitrogen for at least two weeks. Hematoxylin and eosin (H/E) staining, MTT tetrazolium salt assay, and factor VIII immunostaining were used to evaluate the overall histology, epithelial viability, and vascular endothelial integrity, respectively, of cryopreserved flaps. For the in vivo phase, flaps were isotransplanted to 35 recipient animals, divided into three groups: fresh (n = 10), perfused (n = 8), and cryopreserved (n = 17). Blood vessel patency was assessed via Doppler at 1, 7, and 60 days post-transplantation. For in vitro studies, cryopreserved samples (10/10) retained normal cell architecture and vascular endothelial integrity upon H/E and factor VIII staining. The viability index of cryopreserved composite flap skin (n = 10) was 11.17 ± 2.01, which was not significantly different from fresh controls (n = 10, 12.15 ± 1.32). All transplanted flaps in the fresh and perfusion groups survived with healthy color and hair growth at 60 days after operation. Survival in the cryopreserved group ranged from 2 to 60 days, with a mean of 12 days. These results demonstrate that the long term survival of cryopreserved composite tissue transplants is possible. Further studies are needed to refine protocols for the reliable cryopreservation of composite parts.     

Therapeutic Prospective of a Spore-Forming Probiotic—Bacillus clausii UBBC07 Against Acetaminophen-Induced Uremia in Rats

To screen Bacillus clausii UBBC07 as a putative probiotic strain and to examine the protective effect of probiotic—B. clausii UBBC07 spore on uremia on rats induced by acetaminophen. In vitro tests performed to screen potential probiotic strains were gastric and bile acid resistance and ability to reduce pathogen adhesion to surfaces. An in vivo study was performed on rats (n = 18) which were randomly divided into three groups: group I, control—receives normal food and water, groups II and III receive acetaminophen i.p. at the dose of 550 mg/kg/day for 10 days, groups III was treated with B. clausii UBBC07 at a dose of 1 × 10⁹ CFU/day for 15 days. Urea, creatinine, malondialdehyde (MDA), and GSH levels and antioxidant enzymes like super oxide dismutase (SOD) and catalase activity were considered to analyze renal failure. Plasma urea and creatinine levels (p < 0.05) significantly increase and SOD, catalase, and GSH activity level significantly decrease in group II as compared with the control group. After treatment with probiotic, there was a significant increase in SOD and catalase (p < 0.05) and a significant decrease in serum urea, creatinine, and MDA (p < 0.05) in group III in response to group II. The results also revealed that probiotic was able to tolerate pH 3.0–9.0 and 0.3% bile salt. The present study suggests that B. clausii UBBC07 could be used as a novel alternative natural therapy for uremia, a major syndrome of CKD.

     

Effect of radiation on skin expansion and skin flap viability in pigs

The aim of the present study was to investigate the effect of radiation treatment both on skin tissue expansion with the chronic inflation of subcutaneous expanders and on skin flap viability in surgically delayed and expanded skin in the pig. One flank in each of six pigs (initially weighing 17 +/- 1.8 kg) was randomly assigned for radiation treatment, and the contralateral flank served as a nonirradiated control. Three mirror-image, 8 x 10 cm, rectangular templates were marked on each flank; these templates were randomly assigned to the construction of a delayed skin flap (group A), a skin flap raised on expanded skin (group B), or a skin flap raised on expanded skin with a capsulectomy before flap surgery (group C). Radiation treatment was performed using sequential radiation with three fractions per week (810 cGy/fraction) for 2 weeks, with a total dose of 4,860 cGy. Twelve weeks after radiation treatment, skin expanders (8 x 10 cm) were installed subcutaneously in the locations assigned for skin expansion. Skin expansion by the inflation of subcutaneous skin expanders with saline twice weekly was started 8 weeks later and lasted for 3 weeks. Two weeks after surgical delay and the last skin expansion, 8 x 20 cm skin flaps were raised on the locations assigned for delayed skin flaps, expanded skin flaps, and expanded skin flaps with a capsulectomy. Skin flap viability was assessed 24 hours later using a fluorescein dye-staining technique. Skin expansion by the inflation of subcutaneous expanders with saline was slower (p < 0.05) in the radiated skin (39 +/- 6 ml/filling) than in the nonirradiated control skin (51 +/- 6 ml/filling). Radiation reduced the overall area of expanded skin by 23 percent (p < 0.05) compared with the control. Radiation treatment also reduced skin viability by 36 percent (p < 0.05) in the delayed skin flaps, 27 percent (p = 0.10) in the expanded skin flaps, and 36 percent (p < 0.05) in the expanded skin flaps with a capsulectomy when compared with their contralateral, nonirradiated controls. There were no significant differences in skin viability among these three types of skin flaps within the radiated and nonirradiated groups. Taken together, these observations indicate that radiation treatment reduced the effectiveness of the surgical delay procedure, the amount of subcutaneous skin expansion (by an increase in skin area), and skin flap viability. However, a capsulectomy alone did not affect the viability of skin flaps raised on expanded skin.