Alteration of oxidative stress and expression of antioxidases in diaphragm of severely burned rats / 中华烧伤杂志

Objective@#To explore the occurrence of oxidative stress and antioxidases expression in diaphragm of severely burned rats, so that the mechanism of respiratory muscle atrophy and dysfunction post-burn injury will be further clarified.@*Methods@#Eighty male Wistar rats (aged 7 to 8 weeks) were divided into sham injury group and burn injury group according to the random number table, with 40 rats in each group. Rats in burn injury group were inflicted with 50% total body surface area full-thickness scald (hereinafter referred to as burn) on the back and abdomen by immersing into 80 ℃ water for 15 s and 8 s respectively. Immediately after injury, 40 mL/kg normal saline was injected through abdomen for resuscitation, and the wounds were treated with iodine. Except for immersing into 37 ℃ warm water and no resuscitation, the other treatments of rats in sham injury group were the same as those of burn injury group. Whole diaphragms of 8 rats per time point per group were collected after anesthesia at post injury hour (PIH) 2 and on post injury day (PID) 1, 3, 7, and 14, and muscle mass was determined. The protein carbonyl content was determined by microplate reader. The protein expressions of catalase, superoxide dismutase 2 (SOD2), and glutathione peroxidase 1 were determined by Western blotting. Data were processed with analysis of variance of factorial design, t test, and Bonferroni correction.@*Results@#(1) There were no statistically significant differences in the diaphragm mass of rats between the 2 groups at PIH 2 and on PID 1 (t=0.453, 0.755, P>0.05). The diaphragm mass of rats in burn injury group started to decrease from PID 3, which was significantly lower than that of sham injury group (t=3.321, P<0.01). The diaphragm mass of rats in burn injury group started to increase from PID 7 to PID 14, which was significantly lower than that of sham injury group (t=4.622, 4.380, P<0.01). (2) Protein carbonyl content in diaphragm of rats in burn injury group at PIH 2, and on PID 1, 3, 7, and 14 [(2.7±0.3), (2.5±0.5), (2.4±0.4), (2.5±0.4), (3.2±0.6) pg/mL] was significantly higher than that of sham injury group respectively [(1.2±0.4), (1.6±0.3), (1.5±0.7), (1.7±0.3), (1.8±0.4) pg/mL, t=5.994, 3.263, 3.666, 3.158, 5.763, P<0.05 or P<0.01]. (3) Protein expressions of catalase in diaphragm of rats in burn injury group on PID 1 and 3 were close to those of sham injury group (t=0.339, 0.324, P>0.05). There were no statistically significant differences in protein expressions of SOD2 in diaphragm of rats between the 2 groups at PIH 2 and on PID 1, 3, 7, and 14 (t=1.446, 1.385, 0.757, 1.561, 0.531, P>0.05). There were no statistically significant differences in protein expressions of glutathione peroxidase 1 in diaphragm of rats in the 2 groups at PIH 2 and on PID 1, 3, and 7 (t=0.200, 0.729, 0.385, 1.559, P>0.05).@*Conclusions@#Continuous oxidative stress and relatively insufficient expression of antioxidases in diaphragm induced by burn injury could be a contributor to diaphragm atrophy.

Effects of endotoxin/lipopolysaccharide on proliferation and apoptosis of human umbilical cord mesenchymal stem cells / 中华烧伤杂志

<p><b>OBJECTIVE</b>To investigate the effects of different concentrations of lipopolysaccharide (LPS) on proliferation and apoptosis of human umbilical cord mesenchymal stem cells (hUCMSCs) in vitro, and to explore their possible mechanism.</p><p><b>METHODS</b>hUCMSCs from umbilical cord tissue of full-term healthy fetus delivered by caesarean section were isolated and cultured in vitro using tissue attachment method. The 3rd passage hUCMSCs were used in the study. Cells were divided into groups A, B, C, D, and E, which were treated with DMEM/F12 medium containing 0, 0.1, 1.0, 10.0, and 100.0 µg/mL of LPS respectively. In groups B, C, D, and E, methyl-thiazole-tetrazolium assay was used to detect proliferative activity of hUCMSCs at post treatment hour (PTH) 12, 24, and 48 (denoted as absorption value), with 5 samples in each group at each time point; apoptosis of hUCMSCs at PBH 24 was identified with acridine orange-ethidium bromide (AO-EB) staining, with 4 samples in each group; apoptotic rate of hUCMSCs was determined by flow cytometer, with 5 samples in each group. Above-mentioned indexes were determined in group A at the same time points. Data were processed with analysis of variance and LSD- t test.</p><p><b>RESULTS</b>(1) There was no statistically significant difference in proliferative activity of hUCMSCs at PTH 12 among groups A, B, C, D, and E (with t values from -1.67 to 1.33, P values above 0.05). Compared with that of group A, proliferative activity of hUCMSCs was increased in groups B, C, and D at PTH 24 and 48 (with t values from -13.42 to 17.34, P < 0.05 or P < 0.01), especially so in group C. Proliferative activity of hUCMSCs was lower in group E at PTH 24 and 48 than in group A (with t values respectively 8.64 and 17.34, P values below 0.01). (2) Obvious apoptosis of hUCMSCs was observed in group E but not in the other 4 groups with AO-EB staining. (3) Apoptosis rates of hUCMSCs in groups A, B, C, D, and E were respectively (3.1 ± 0.6)%, (2.6 ± 0.7)%, (2.9 ± 0.8)%, (3.1 ± 0.4)%, (25.1 ± 2.7)% (F = 272.19, P < 0.01). Apoptotic rate of hUCMSCs in group B, C, or D was respectively close to that in group A (with t values respectively 1.22, 0.57, -0.14, P values above 0.05), but it was higher in group E than in group A (t = -17.63, P < 0.01).</p><p><b>CONCLUSIONS</b>hUCMSCs proliferation may be promoted by low concentration of LPS. hUCMSCs proliferation is inhibited or induced to apoptosis along with the increase in concentration of LPS, and it may be related to activation of different major molecular signaling pathways by different concentrations of LPS.</p>

Advances in the research on the relationship between brown adipose tissue and metabolism in burn and trauma / 中华烧伤杂志

Hypermetabolism and insulin resistance are prominent features of trauma including burn injury, surgery, and infection. Hypermetabolism results in insufficiency in energy supply, which induces organ function lesion, immune suppression, high infection rate, and wound healing delay, thus exerting a strong impact on patients' quality of life and prognosis. The molecular mechanism in the occurrence and development of hypermetabolism is very complicated, and it has not been fully elucidated. Recently, brown adipose tissue (BAT) was found to be present not only in rodents but also in humans, and its activity was associated with resting metabolic rate. BAT may become the new target of research in prevention and control of metabolic disorder.

Analysis of the sequence of the variant exon-8 of fibroblastic Fas gene in keloid / 中国组织工程研究

BACKGROUND:Keloid is the outcome of wound-healing process,and the result of massive accumulation of life-prolonged fibroblasts with gene mutation as well as the excessive synthesis of collagenous fibers.OBJECTIVE:To probe the relationship between the fibroblasts and the mutations of the exon-8 of Fas gene in keloid.DESIGN:An open study with gene sequence as the subjects of observation.SETTING :The Department of Plastic Surgery of Southern Hospital of the First Military Medical University.PARTICIPANTS:This experiment was carried out at the Tropical Disease Research Institute of the First Military Medical University of Chinese PLA in 2001. All keloid and hypertrophic scar tissues were obtained from the patients who received orthopedic surgical operations at the Southern Hospital, including 15 patients with keloid whose pathological areas were located respectively at the earlobe and the prothorax and 12patients with hypertrophic scars whose pathological areas being located at the instep and the elbow. At the same time, normal skin and the peripheral blood samples from the patients themselves with keloid were taken as the self-control and the skin and the peripheral blood samples from the normal people and the patients with hypertrophic scars were taken as the normal control.METHODS: PCR-SCCM technique and gene sequence analysis were used to detect the gene structure of exon-8 in the Fas gene from 15 patients.MAIN OUTCOME MEASURES:The gene structure of exon-8 in the Fas gene derived from the tissues and the peripheral blood samples of all the groups.RESULTS: ① Heterozygous loss was observed in the exon-8 of the Fas gene in all 15 keloid patients; ② Gene sequence was found to be abnormal in 11 cases out of 15 keloid patients, presenting gene mutation in 4 loci.CONCLUSION: Heterozygous loss and gene mutation was detected in the exon 8 of Fas gene of keloid, suggesting that Fas protein in keloid has functional defect that is closely associated with gene mutation.

The genetic structure of the fibroblastic Fas in keloid / 中国组织工程研究

BACKGROUND:Keloid is the outcome of wound-healing process,and the result of massive accumulation of life-prolonged fibroblasts with gene mutation as well as the excessive synthesis of collagenous fibers.OBJECTIVE:To probe into the structural relations of exons 7-9 of fibroblastic Fas gene in keloid tissues.DESIGN:A self-controlled experimental study with cicatricial tissues as the subjects.SETTING:Department of Plastic Surgery of Southern Hospital of the First Military Medical University of Chinese PLA.PARTICIPANTS:This experiment was carried out at the Tropical Disease Research Institute of the First Military Medical University of Chinese PLA in 2001. All keloid and hypertrophic scar tissues were obtained from the patients who received orthopedic surgical operations at the Southern Hospital, including 15 patients with keloid and 12 patients with hypertrophic Scars. Normal skin and peripheral blood were obtained from the keloid patients as self-control. Meanwhile pathological tissues and normal skin and peripheral blood were obtained from patients with hypertrophic scars as normal control.INTERVENTION:PCR-single strand conformation polymorphism was used to find the structure of the exons 7-9 in Fas gene in15 patients with keloid.MAIN OUTCOME MEASURES:The structure of the exons 7-9 in Fas gene.RESULTS:Heterozygous loss of Fas gene exon-8 was observed in all the 15 keloid patients, and 20% of them displayed an increase in exon-9 allele band.CONCLUSION: The genetic structure of Fas gene showed no mutation in hypertrophic scars, normal skin and the peripheral blood,but mutations were detected in exons-8 ,and -9 of Fas gene in keloid. This was closely related with the disfunction of its encoded proteins.

The distributing characteristics and proliferating activity of fibroblasts from the surrounding skin of keloids / 中华整形外科杂志

<p><b>OBJECTIVE</b>To investigate whether there are abnormal fibroblasts derived from the surrounding skin of keloids so that a more accurate therapy for keloids could be obtained.</p><p><b>METHODS</b>Samples were taken for cell culture. When primary cells fully covered the culture bottle, the shape and distributing characteristics of fibroblasts were observed under the light microscope. 6-8 passage fibroblasts were selected for comparing the proliferating activity by MTT contrasting color method.</p><p><b>RESULTS</b>The fibroblasts have the same shape in all groups. But the fibroblasts derived from the surrounding skin grow crossly and overlapped just as the fibroblasts from keloids. The proliferating activity of the fibroblasts from surrounding skin is not as high as that from the border of keloids, but is higher than the normal skin fibroblasts derived either from a normal person or a patient with keloid.</p><p><b>CONCLUSION</b>It is likely that there are abnormal fibroblasts in the surrounding skin of keloids.</p>

STUDY ON APOPTOSIS OF FffiROBLASTS DERIVED FROM THE SURROUNDING SKIN OF KELOIDS / 解放军医学杂志

The aim of this study was to investigate if there are abnormal fibroblasts derived from the skin surrounding keloids in order to have a better understanding for keloid progression. All the samples were used for cell culture. Flow cytometry was used to compare the apoptotic rate of fibroblasts derived from keloid and its surrounding skin, when it was cultured in serum-deprived medium for 24 hours or was induced by Fas antibody. After cultured in serum-deprived medium for 24 hours, the apoptotic rate of fibroblasts derived from the surrounding skin of keloid increased to an amount between that of normal skin and keloids. The apoptotic rate of normal skin fibroblasts increased more than that of keloids. Moreover, when induced by Fas antibody, the apoptotic rate of fibroblasts derived from the surrounding skin increased not so high as that of normal skin(P0. 05). Therefore, at least there are some fibroblasts in the surrounding skin of keloids, in which apoptosis can not be induced as in normal skin.