A modified culture strategy of human keratinocytes to shorten the primary culture time.

Shortening time from biopsy to graft preparation is crucial for the coverage of extensive burn wound in major burn patients. This study was aimed to shorten the culture time of keratinocytes by means of one modified cell culture method. Three factors (temperature of dispase, area of skin, and age of patient) that might have impacts on cell behavior were evaluated. The results showed that cells isolated with dispase at 37°C exhibited an improved cell activity than being isolated at 4°C. The time that cells reached subconfluence with various skin areas was in order of 3 cm(2) < 2 cm(2) < 1 cm(2) (120.07 ± 5.03 h, 141.33 ± 4.16 h, and 193.33 ± 6.11 h, respectively). Furthermore, compared with the young and middle-aged groups, proliferation of keratinocytes isolated from children skin tissue was better. These results indicated that 3 cm(2) skin biopsy from a young patient, isolated with dispase at 37°C, was a promising strategy to shorten the cultivation of keratinocytes.

Zeolite-based hemostat QuikClot releases calcium into blood and promotes blood coagulation in vitro.

AIM: To examine the changes in electrolyte concentrations after addition of zeolite-based hemostat QuikClot in blood and the effects of zeolite on blood coagulation in vitro. METHODS: Fresh blood was taken from healthy adult volunteers and sheep, and the electrolyte concentrations in blood were measured using a blood electrolyte analyzer. Zeolite Saline Solution (ZSS) was prepared by addition of 2 g zeolite to 0.9% NaCl solution (4, 8, or 16 mL). The electrolytes in ZSS were measured using inductively coupled plasma atomic emission spectroscopy. The prothrombin time (PT) and activated partial thromboplastin time (APTT) of blood were measured using the test tube method. The activated clotting time (ACT) and clotting rate (CR) of blood were measured with Sonoclot Coagulation and Platelet Function Analyzer. RESULTS: Addition of zeolite (50 and 100 mg) in 2 mL human blood significantly increased Ca(2+) concentration, while Na(+) and K(+) concentrations were significantly decreased. Addition of zeolite (50 and 100 mg) in 0.9% NaCl solution (2 mL) caused similar changes in Ca(2+) and Na(+) concentrations. Si(4+) (0.2434 g/L) and Al(3+) (0.2575 g/L) were detected in ZSS (2 g/8 mL). Addition of ZSS in sheep blood shortened APTT in a concentration dependent manner, without changing PT. ZSS or aqueous solution of CaCl2 that contained Ca(2+) concentration identical to that of ZSS significantly shortened ACT in human blood without significantly changing CR, and the effect of ZSS on ACT was not significantly different from that of CaCl2. CONCLUSION: Zeolite releases Ca(2+) into blood, thus accelerating the intrinsic pathway of blood coagulation and shortening the clot formation time.

Epidemiological studies of electrical injuries in Shaanxi province of China: a retrospective report of 383 cases.

A statistical survey was conducted at the Burn Unit of the Tangdu Hospital, Shaanxi, China, during the 10-year period from January 2000 to December 2009. In this retrospective study, 383 patients who admitted to our burn unit because of electrical trauma were included. Data including the patient's general condition, clinical presentation, complications and operation times was collected retrospectively and analyzed with epidemiological methods. Subjects in our collective were predominantly male (90.3%, n=346/383) and were composed by those who injured in work-related incidents (78.3%, n=300/383), rural individuals (58.2%, n=223/383) and students (9.4%, n=36/383). High voltage was directly correlated to severity clinical complications, and amputation. The percentage of myocardial impairment was 79.3% (n=92/116) among patients who suffered with electrical current through heart tissue. Along with the more developed east area of China, electrical injuries are becoming a growing concern of the developing West part in China as well. Electrical injuries induce serious tissue damage, need long hospital stay, and result in high rate of permanent disability and economic hardship for the afflicted families. A competent prevention program needs to be developed to address this problem.

Electrical injury alters ion channel expression levels and electrophysiological properties in rabbit dorsal root ganglia neurons.

The electrophysiological and morphological changes of nerve fibers induced by electrical injury have been widely addressed. However, the changes of ion channels in neurons after electrical shocks have not been systematically investigated yet. In this study, the sciatic nerves of rabbit were injured by 50 V 50 Hz, 110 V 50 Hz, and 220 V 50 Hz alternating current, respectively. One week later, the expression levels and electrophysiological changes of voltage-gated potassium (Kv) and sodium (Nav) channels in dorsal root ganglia (DRG) neurons were evaluated by RT-PCR, immunofluorescence staining and patch clamp technique. The Nav1.1 expression was decreased by 50V injury. The Kv1.2, Kv1.4, Nav1.1 and Nav1.7 expression levels and Kv current densities were reduced after 110 V injury. Under the 220 V injury circumstance, Kv1.2, Nav1.1, Nav1.7 expression levels, Kv current densities and TTX-R Na(+) current densities were significantly decreased, while TTX-S Na(+) current densities increased. These findings suggest that the expression levels, subunit compositions, and electrophysiological properties of Kv and Nav channels are altered after electrical injury, and the severity of injury gets worse as injury voltage increases.

[The influence of vacuum-assisted drainage on the growth of capillaries in the wound produced by explosion in pig].

OBJECTIVE: To investigate the influence of vacuum-assisted closure (VAC) technique on the growth of capillaries in the wound of the pig produced by explosion. METHODS: Four small white pigs were inflicted with 16 explosion wounds [(7.3 +/- 1.0) cm2 in area] on both sides of the buttocks, shoulders and hips by detonation of a specific type of explosive, and the wounds were randomly divided into 2 groups, i. e, control (C, with conventional treatment from 2 post-injury day (PID) on and treatment (T, with VAC treatment after debridement from 2 PID on) groups, with 8 wounds in each group. Wound tissues of 2mm x 2mm x 2mm in size were harvested for pathological examination before treatment and on 1 and 3 post-treatment day (PTU). The differentiation of adventitial cells were examined with light microscope, and the pixel value of desmin positive particles and the luminal area of newly formed capillaries were assessed with Image C software. RESULTS: Most of vessels in the wound of both groups were in elliptic shape when observed in longitudinal section. In C group, few newly formed capillaries vessels with lack of pericytes were observed before treatment and on 1, 3 PTD, then the number began to increase on 6 PTD. In T group, the number of newly formed capillaries with pericytes was increased on 1 PTD, and it continued to increase thereafter. The pixel values of desmin positive particles in C group on 1, 3, and 6 PTD were (91 +/- 54), (199 +/- 85), and (1552 +/- 298), respectively, which were obviously higher than those in T group [(2569 +/- 330), (3984 +/- 377), (9611 +/- 960), P < 0.01]. The area of vessel lumen in C group was (59 +/- 36), (250 +/- 70), and (938 +/- 287) microm2, respectively on 1, 3, and 6 PTD, which was also smaller than those in T group [(818 +/- 234), (4518 +/- 1080), and (9058 +/- 1656) microm2, P < 0.01]. CONCLUSION: Compared with conventional therapy, VAC can not only accelerate the formation of new capillaries, but also enhance the differentiation of pericytes and the process of enwrapping them around the vessels, and increase the luminal area of newly formed capillaries.

[The changes in blood flow in sciatic nerve after electrical injury in rabbit].

OBJECTIVE: To study the changes in sciatic nerve blood flow and the expression of collagen type I after electric injury of rabbit nerve with different voltages. METHODS: Thirty-six healty rabbits were randomized into 3 groups before receiving injury with electricity in voltages, i.e. 50 v, 75 v, and 100 v groups. The changes in blood flow of sciatic nerve were observed with Laser Doppler Flowmeter immediately after injury and 1, 4, 8 weeks after injury. The changes in the expression of collagen type I was observed by immunohistochemical method, and the positive expression rate was calculated. RESULTS: The sciatic nerve blood flow increased in all groups immediately after electric injury. In the 75 v and 100v groups, the nerve blood flow [(53 +/- 3 ), (48 +/- 5) PU] was obviously lower than that of normal value [(62 +/- 4) PU, P < 0.05]. There was little collagen type I deposition in 50 v group, while brown collagenous fibers in epineurium and perineurium were observed in 75 v and 100v groups 4 and 8 weeks after injury. The expression of collagen type I in all groups were obviously higher than that of normal value, and that in 75v and 100 v groups were higher than that in 50 v group at bachl time-point (P < 0.01). CONCLUSION: The restoration of sciatic nerve blood flow is postponed following by the injury with increase of the electrical voltage. The collagen deposition after electrical injury may be one of the reasons for nerve blood flow decrease.