OBJECTIVETo study the effects of insulin on the proteolysis of cultured rabbit skeletal muscular myotubes in vitro, and their possible mechanisms.

METHODSMuscles of lower limbs of juvenile rabbits were isolated for tissue-block culture. After passage, myoblasts were formed and fused into myotubes. Then the protein in myotubes was radiolabelled with L-[ 3,5-3H] tyrosine. The myotubes were cultured in DMEM medium containing 100 nmol/L insulin (n = 24, group B) , 100 nmol/L dexamethasone (n = 24, group C) , 100 nmol/L insulin and 100 nmol/L dexamethasone (n = 24, group D) , no insulin or dexamethasone (n =24, group A), respectively. Twenty-four hours after culture, the L-[3,5-3H] tyrosine content in culture medium and cells were determined, and the degradation rates of protein were calculated. The mRNA expressions of ubiquitin and protease C2 subunit were determined by Northern blot.

RESULTSThe degradation rates of myotube protein in group A(0. 38+/-0.04) was obviously lower than that in group C (0.50+/-0.03, P <0.01), but it was obviously higher than that in group B(0. 35+/-0.03, P <0.05). Though the degradation rates of myotube protein in group D (0.41+/-0. 03) was evidently lower than that in group C ( P < 0.01) , it was still higher than that in group A( P < 0.05 ). The mRNA expressions of ubiquitin and protease C2 subunit in group A ( the scale: 2. 4 kb ubiquitin was 0. 82+/-0. 15, 1. 2 kb ubiquitin was 0. 60+/-0. 10, C2 subunit was 0. 75+/-0. 16) was obviously lower than that in group C ( the scale: 2.4 kb ubiquitin was 2. 15+/-0. 23, 1.2 kb ubiquitin was 1.50+/-0. 14,C2 subunit was 1.50+/-0. 13 , P <0. 01) , but it in group D was lower than that in group C (the scale: 2. 4 kb ubiquitin was 1. 25+/-0. 17, 1. 2 kb ubiquitin was 0. 85+/-0. 09, C2 subunit was 0. 90+/-0. 15, P <0. 01) , and it was similar to that in group B (the scale: 2.4 kb ubiquitin was 0. 85+/-0.07, 1.2 kb ubiquitin was 0. 65+/- 0. 12, C2 subunit was 0. 76 +/-0. 09, P > 0. 05).

CONCLUSIONThe effects of insulin on the activity of ubiquitin-proteasome pathway and the proteolytic rate in normal myotubes were relatively weak. However, insulin can significantly inhibit the effects of dexamethasone on the gene expressions of ubiquitin system and the proteolytic rate in myotubes, but the mechanism needs further research.

Animals ; Cells, Cultured ; In Vitro Techniques ; Insulin ; pharmacology ; Male ; Muscle Fibers, Skeletal ; drug effects ; metabolism ; Muscle Proteins ; metabolism ; Rabbits ; Ubiquitin ; metabolism

OBJECTIVETo investigate the effect of early escharectomy on resting energy expenditure (REE) in severely burned patients dynamically with the metabolic monitoring and diagnostic system.

METHODSFifty-six adult male patients with severe burns were divided into early escharectomy (group A, n = 39, escharectomy within 5 PBDs) and non-early escharectomy (group B, n = 17, escharectomy after 5 PBDs) groups. The wounds of full thickness and deep partial thickness burn in the two groups were all excised and covered with allogeneic skin and autologous micro-skin in the first operation. The changes in REE were observed dynamically at the bedside of the patients with the metabolic monitoring and diagnostic system. The plasma contents of IL-6, IL-8, TNF-alpha and LPS from 9 patients in group A and 7 in group B were also determined dynamically.

RESULTSAll patients survived. The REE in both groups was elevated markedly, but REE in group A was lower compared with group B before and after escharectomy within 14 days. (P < 0.05). The plasma level of IL-6, IL-8, TNF-alpha and LPS in group A were obviously lower than those in group B (P < 0.05).

CONCLUSIONThe hypermetabolic response of burn patients with severe burns could be lowered by early escharectomy, and it seemed to be related to the decrease of the release of proinflammatory mediators.

Adult ; Basal Metabolism ; Burns ; metabolism ; physiopathology ; surgery ; Humans ; Interleukin-6 ; blood ; Interleukin-8 ; blood ; Lipopolysaccharides ; blood ; Male ; Postoperative Care ; Time Factors ; Treatment Outcome ; Tumor Necrosis Factor-alpha ; metabolism

OBJECTIVETo investigate changes in apoptosis-related ligands in serum in rats with severe scald and the effect of intensive insulin therapy on the changes.

METHODSOne hundred and fifty Wistar rats were randomly divided into 3 groups: sham burn (SB), scald (S) and treatment (T) groups. Rats in S and T groups were inflicted with 40% TBSA full-thickness burn, followed by intraperitoneal injection with 40 mL/kg of isotonic saline for resuscitation. Rats in T group were subcutaneously injected insulin in a dose of 0.25 U/100 g 24 hours after burn injury, and every 12 hours for 5 days (0.25, 0.50, 0.75, 1.00, 1.25 U/100 g each day, respectively) to control the level of blood glucose between 3 and 6 mmol/L. Rats in SB group were sham scalded at 37 degrees C without resuscitation. Blood was drawn from abdominal aorta on 1, 4, 7, 10, 14 post burn day (PBD) for determination of serum levels of TNF-alpha, soluble Fas ligand (sFasL) and soluble Fas receptor (sFas) by enzyme-linked immunosorbent assay (ELISA), and insulin by radioimmunity assay (RIA).

RESULTSThe serum level of TNF-alpha in S group peaked on 1 PBD (30.9 +/- 8.7) ng/L, which showed statistically significant difference when compared with that of SB and T groups (12.7 +/- 2.8) ng/L, (16.8 +/- 4.7) ng/L, respectively, P < 0.01), then lowered gradually to become similar to that of SB group on 7 PBD. The level of TNF-alpha in T group increased gradually, but was obviously lower than that of S group on 1, 4, 7 PBD (P < 0.01). The level of sFasL in S (on 7-14 PBD) and T (4-10 PBD) groups was significantly higher than that in SB group (P < 0.05), then lowered to normal level. The levels of sFas on 4-10 PBD in T group were obviously higher than that in S and SB group (P < 0.05). Ratio of sFasL to sFas in serum of S group was higher than that in SB group on 7, 10 PBD, which was higher than that in T group on 7 PBD (P < 0.05). There was significant decrease in serum level of insulin in S group compared with that of SB group on 4-10 PBD (P < 0.05). The level of insulin in T group increased on 1 PBD, peaked on 4 PBD (327 +/- 15 microU/mL), which was significantly higher than that in SB and S groups (42 +/- 15, 28 +/- 10 microU/mL, respectively, P < 0.01), then decreased gradually to normal level.

CONCLUSIONSInsulin may inhibit apoptosis after burn by down-regulating secretion of apoptotic ligands.

Animals ; Apoptosis ; Blood Glucose ; analysis ; Burns ; blood ; drug therapy ; Fas Ligand Protein ; blood ; Insulin ; therapeutic use ; Male ; Rats ; Rats, Wistar ; Tumor Necrosis Factor-alpha ; blood ; fas Receptor ; blood

OBJECTIVETo investigate changes in proliferative activity of myoblasts in skeletal muscle and potential role of phosphorylated Akt on it, so that a better understanding in mechanisms of skeletal muscle atrophy after burn injury will be got.

METHODSOne hundred and twenty Wistar rats were randomly divided into 2 groups: control and severe thermal injury group. Rats in severe thermal injury group were subjected to a 40% total body surface area full-thickness scald injury, and Tibialis Anterior (TA) muscles were collected on 0, 1, 4, 7, 10, 14 days post-injury. After muscle mass determined, immunohistochemical double staining was used for detection of Proliferative Cell Nuclear Antigen (PCNA) of myoblasts. Protein expression of total Akt and phosphorylated Akt was determined by Western Blot.

RESULTSBurn injury induced significant reduction of TA muscle mass and maximal reduction of it appeared by 4 days after injury (P < 0.01). Proliferative activity of myoblasts decreased significantly from the first day post-injury (P < 0.01) and increased slowly to basal level of controls after 7 days post-injury. The phosphorylated Akt was undetectable in both of controls and injured samples before 4 days but increased significantly after 7 days post-injury (P < 0.01), though total Akt expression had no significant alteration at any time points (P > 0.05).

CONCLUSIONSDecrease in proliferative activity of myoblasts may be one of the contributors of significant atrophy of skeletal muscle after burn injury. Effect of phosphorylated Akt on proliferation attenuated in early stage and increased significantly in later stage after burn injury may partly explain the changes in proliferative activity of myoblasts.

Animals ; Burns ; metabolism ; pathology ; Cell Proliferation ; Disease Models, Animal ; Male ; Muscle, Skeletal ; metabolism ; pathology ; Myoblasts ; metabolism ; pathology ; Phosphorylation ; Proto-Oncogene Proteins c-akt ; metabolism ; Random Allocation ; Rats ; Rats, Wistar

BACKGROUNDPerforator flaps are used extensively in repairing soft tissue defects. Superior gluteal artery perforator flaps are used for repairing sacral defects, but the tension required for direct closure of the donor area after harvesting of relatively large flaps carries a risk of postoperative dehiscence. This research was to investigate a modified superior gluteal artery perforator flap for repairing sacrococcygeal soft tissue defects.

METHODSFrom June 2003 to April 2010, we used our newly designed superior gluteal artery perforator flap for repair of sacrococcygeal soft tissue defects in 10 patients (study group). The wound and donor areas were measured, and the flaps were designed accordingly. Wound healing was assessed over a follow-up period of 6 - 38 months. From January 1998 to February 2003, twelve patients with sacrococcygeal pressure sores were treated with traditional methods, VY advancement flaps or oblong flaps, as control group.

RESULTSAfter debridement, the soft tissue defects ranged from 12 cm × 10 cm to 26 cm × 22 cm (mean 16.3 cm × 13.5 cm). Four patients were treated using right-sided flaps ranging from 15 cm × 11 cm to 25 cm × 20 cm (mean 18.2 cm × 14 cm). Four patients were treated using left-sided flaps, and two were treated using both right- and left-sided flaps. Suction drains were removed on postoperative Days 3 - 21 (mean 5.9) and sutures were removed on postoperative Days 12 - 14. Each flap included 1 - 2 perforators for each of the donor and recipient sites. Donor sites were closed directly. All flaps survived. In eight patients, the wounds healed after single-stage surgery. After further debridement, the wounds of the remaining two patients were considered healed on postoperative Days 26 and 33, respectively. The rate of first intention in the study group (80%, 8/10) significantly increased than that of control group ((25%, 3/12), χ(2) = 4.583, P = 0.032). Follow-up examinations found that the flaps had a soft texture without ulceration. In the two patients without paraplegia, the range of motion of the hip joints was not affected.

CONCLUSIONThe use of the quadrilobed superior gluteal artery perforator flap can overcome the disadvantages of traditional perforator flaps and represents an improved approach for repairing soft tissue defects in the sacrococcygeal region.

Adult ; Debridement ; Female ; Humans ; Male ; Middle Aged ; Perforator Flap ; Sacrococcygeal Region ; surgery ; Soft Tissue Injuries ; surgery ; Wound Healing

OBJECTIVETo evaluate a microarray-based mutation screening method for genetic deafness and its application in prenatal diagnosis.

METHODSMutation screening of common deafness genes was performed in pregnant women and volunteers spouses. Nine common mutations in four major deafness genes, GJB2, GJB3, SLC26A4 and mitochondrial 12S rRNA, were detected simultaneously by a microarray-based method. Genetic counseling was given based on their testing results.

RESULTS5.11% of pregnant women carried at least one mutation. Among them, seven carried mutation in the mitochondria 12S rRNA gene and were offered aminoglycoside-induced ototoxicity warning. For other mutation carriers of GJB2 or SLC26A4 genes, additional mutation screening was performed in their husbands by direct sequencing. A total of 20 couples were at risk of giving birth to children with genetic deafness. Of five couples who selected to undergo prenatal diagnostic testing of the fetus, four were diagnosed as wild type or heterozygous for the tested genes and one as p.V37I/c.235delC compound heterozygous for GJB2.

CONCLUSIONSDNA microarray is a quick, easy and reliable method to screen mutations in genetic deafness genes. Application of this method in prenatal screening and diagnosis might effectively reduce the occurrence of genetic deafness.

Adult ; Connexins ; Deafness ; diagnosis ; genetics ; prevention & control ; Female ; Genetic Counseling ; Genetic Testing ; Humans ; Mutation ; Oligonucleotide Array Sequence Analysis ; Pregnancy ; Pregnancy Trimester, Second ; Prenatal Diagnosis ; methods ; Young Adult

BACKGROUNDSevere burn-blast combined injury is a great challenge to medical teams for its high mortality. The aim of this study was to elucidate the clinical characteristics of the injury and to present our clinical experiences on the treatment of such cases.

METHODSFive patients with severe burn-blast combined injuries were admitted to our hospital 77 hours post-injury on June 7, 2005. The burn extent ranged from 80% to 97% (89.6% +/- 7.2%) of TBSA (full-thickness burns 75% - 92% (83.4% +/- 7.3%)). All the patients were diagnosed as having blast injury and moderate or severe inhalation injury. Functions of the heart, liver, kidney, lung, pancreas and coagulation were observed. Autopsy samples of the heart, liver, and lungs were taken from the deceased. Comprehensive measures were taken during the treatment, including protection of organ dys function, use of antibiotics, early anticoagulant treatment, early closure of burn wounds, etc. All the data were analyzed statistically with t test.

RESULTSOne patient died of septic shock 23 hours after admission (four days after injury), the others survived. Dysfunction of the heart, liver, lungs, pancreas, and coagulation were found in all the patients on admission, and the functions were ameliorated after appropriate treatments.

CONCLUSIONSBurn-blast combined injury may cause multiple organ dysfunctions, especially coagulopathy. Proper judgment of patients' condition, energetic anticoagulant treatment, early closure of burn wounds, rational use of antibiotics, nutritional support, intensive insulin treatment, timely and effective support and protection of organ function are the most important contributory factors in successful treatment of burn-blast combined injuries.

Adult ; Anti-Bacterial Agents ; therapeutic use ; Blast Injuries ; complications ; physiopathology ; therapy ; Burns ; complications ; physiopathology ; therapy ; Humans ; Male ; Nutrition Therapy ; Psychotherapy ; Respiration

BACKGROUNDMass burn casualties are always a great challenge to a medical team because a large number of seriously injured patients were sent in within a short time. Usually a high mortality is impending. Experiences gained from successful treatment of the victims may be useful in guiding the care of mass casualties in an armed conflict.

METHODSThirty-five burn victims in a single batch, being transferred nonstop by air and highway from a distant province, were admitted 48 hours post-injury. All patients were male with a mean age of (22.4 +/- 8.7) years. The burn extent ranged from 4% to 75% ((13.6 +/- 12.9)%) total body surface area. Among them, thirty-two patients were complicated by moderate and severe inhalation injury, and tracheostomy had been performed in 15 patients. Decompression incisions of burn eschar on extremities were done in 17 cases before transportation. All the thirty-five patients arrived at the destination smoothly via 4-hour airlift and road transportation. Among them, twenty-five patients were in critical condition.

RESULTSThese thirty-five patients were evacuated 6 hours from the scene of the injury, and they were transferred to a local hospital for primary emergency care. The patients were in very poor condition when admitted to our hospital because of the severe injury with delayed and inadequate treatment. Examination of these patients at admission showed that one patient was suffering from sepsis and multiple organ dysfunction syndrome. Dysfunction of the heart, lung, liver, kidney, and coagulation were all found in the patients. Forty-eight operations were performed in the 23 patients during one month together with comprehensive treatment, and the function of various organs was ameliorated after appropriate treatment. All the 35 patients survived.

CONCLUSIONSA well-organized team consisting of several cooperative groups with specified duties is very important. As a whole, the treatment protocol should be individualized, basing on the extent of the injury and the care that the patient had received at the spot. During airlift, the stretchers should be arranged perpendicular to the longitudinal axis of the cabin. The treatment protocol in our hospital consisted mainly of prompt effective relief of all life-threatening complications, followed by early closure of burn wounds, appropriate use of anti-infection therapy, emphasis on nutritional support, correction of metabolic disorders, alleviation of immunosuppression, correction of coagulopathy, and effective support and protection of organ function.

Adolescent ; Adult ; Burns ; drug therapy ; pathology ; surgery ; therapy ; Emergency Medical Services ; Emergency Service, Hospital ; Female ; Hospitals ; Humans ; Male ; Middle Aged ; Time Factors ; Transportation of Patients ; Treatment Outcome ; Young Adult