Preparation of combined cross-linked enzyme aggregates containing galactitol dehydrogenase and NADH oxidase for L-tagatose synthesis via in situ cofactor regeneration.

The combined cross-linked enzyme aggregates (combi-CLEAs) containing galactitol dehydrogenase (Gdh) and NADH oxidase (Nox) were prepared for L-tagatose synthesis. To prevent the excess consumption of cofactor, Nox in the combi-CLEAs was used to in situ regenerate NAD+. In the immobilization process, ammonia sulfate and glutaraldehyde were used as the precipitant and cross-linking reagent, respectively. The preparation conditions were optimized as follows: 60% ammonium sulfate, 1:1 (molar ratio) of Gdh to Nox, 20:1 (molar ratio) of protein to glutaraldehyde, and 6 h of cross-linking time at 35 °C. Under these conditions, the activity of the combi-CLEAs was 210 U g-1. The combi-CLEAs exhibited higher thermostability and preserved 51.5% of the original activity after eight cycles of reuses at 45 °C. The combi-CLEAs were utilized for the preparation of L-tagatose without by-products. Therefore, the combi-CLEAs have the industrial potential for the bioconversion of galactitol to L-tagatose.

One-step selective affinity purification and immobilization of His-tagged enzyme by recyclable magnetic nanoparticles.

The NiFe2O4 magnetic nanoparticles (NF-MNPs) were prepared for one-step selective affinity purification and immobilization of His-tagged recombinant glucose dehydrogenase (GluDH). The prepared nanoparticles were characterized by a Fourier-transform infrared spectrophotometer and microscopy. The immobilization and purification of His-tagged GluDH on NF-MNPs were investigated. The optimal immobilization conditions were obtained that mixed cell lysis and carriers in a ratio of 0.13 in pH 8.0 Tris-HCl buffer at 30℃ and incubated for 2 h. The highest activity recovery and protein bindings were 71.39% and 38.50 µg mg-1 support, respectively. The immobilized GluDH exhibited high thermostability, pH-stability and it can retain more than 65% of the initial enzyme after 10 cycles for the conversion of glucose to gluconolactone. Comparing with a commercial Ni-NTA resin, the NF-MNPs displayed a higher specific affinity with His-tagged recombinant GluDH.

Using galactitol dehydrogenase coupled with water-forming NADH oxidase for efficient enzymatic synthesis of L-tagatose.

L-Tagatose, a promising building block in the production of many value-added chemicals, is generally produced by chemical routes with a low yield, which may not meet the increasing demands. Synthesis of l-tagatose by enzymatic oxidation of d-galactitol has not been applied on an industrial scale because of the high cofactor costs and the lack of efficient cofactor regeneration methods. In this work, an efficient and environmentally friendly enzymatic method containing a galactitol dehydrogenase for d-galactitol oxidation and a water-forming NADH oxidase for regeneration of NAD+ was first designed and used for l-tagatose production. Supplied with only 3 mM NAD+, subsequent reaction optimization facilitated the efficient transformation of 100 mM of d-galactitol into l-tagatose with a yield of 90.2 % after 12 h (obtained productivity: 7.61 mM.h-1). Compared with the current chemical and biocatalytic methods, the strategy developed avoids by-product formation and achieves the highest yield of l-tagatose with low costs. It is expected to become a cleaner and more promising route for industrial biosynthesis of l-tagatose.

Prognostic significance of preoperative platelet-lymphocyte ratio in a Chinese cohort patient with colorectal cancer.

Cancer-related systemic inflammation affects many aspects of malignancy. The platelet-to-lymphocyte ratio (PLR), an easily applicable inflammatory marker based on platelet and lymphocyte counts, is associated with the clinical outcome of some cancers. The present study aimed to investigate the prognostic significance of the preoperative PLR in a cohort of colorectal cancer (CRC) patients. A total of 138 patients with CRC were enrolled in this retrospective study. The optimal cutoff value for the PLR was calculated using receiver operating curve (ROC) analysis. The correlation of PLR with the clinicopathological characteristics of patients was explored. Cox proportional hazard analysis was applied to determine the independent prognostic effect of PLR. PLR of 248 yielded the most optimal predictive value for the prognosis of CRC [area under the curve (AUC) = 0.820]. High level of PLR was significantly associated with lymph node and distance metastasis (P<0.001 and = 0.003, respectively), vascular and perinural invasion (P<0.001), advanced TNM stage (P<0.001), and poor differentiation (P = 0.037). Furthermore, the univariable analysis showed a significant impact of increased PLR on OS (HR = 4.326, 95% CI: 2.903-6.445, P<0.001), while this association remained significant in multivariable analysis (adjusted HR = 4.605, 95% CI: 2.786-7.611, P<0.001). Our findings indicated that elevated preoperative PLR might have potential value in predicting poor outcome in patients with CRC.

Wound-healing improvement by resurfacing split-thickness skin donor sites with thin split-thickness grafting.

INTRODUCTION: Split-thickness skin graft (STSG) donor site dressing has been controversial until now. Our study aimed to assess the patient comfort and wound-healing efficacy with the application of thin split-thickness skin grafts regrafting on STSG donor sites. METHODS: One hundred ninety-two consecutive patients undergoing split-thickness skin grafting were included in the study, and the participants were randomly divided into the following three groups: group A was regrafted with thin STSGs and groups B and C were covered with occlusive hydrocellular dressing and paraffin gauze, respectively. The participants were compared according to the epithelialization time, pain and scar formation. RESULTS: The average time of epithelialization was 6.2 ± 1.1 days in group A, 11.1 ± 2.1 days in group B and 13.5 ± 2.5 days in group C. The pain scores on days 2 and 5 after operation were 2.3 ± 0.8 and 1.9 ± 0.8 in group A, 2.5 ± 1.1 and 3.9 ± 1.3 in group B, and 3.8 ± 1.4 and 5.9 ± 2.1 in group C. The scar scores at half a year and one year after operation were 4.3 ± 0.6 and 2.50 ± 0.6 in group A, 7.4 ± 0.6 and 6.2 ± 0.6 in group B, and 11.8 ± 0.4 and 10.9 ± 1.0 in group C, separately. The difference in the three groups was significant. CONCLUSION: Utilizing thin STSGs regrafting on donor sites could significantly shorten the epithelialization time, reduce pain and prevent hyperplastic scar formulation.

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.

The roles of autophagy and apoptosis in burn wound progression in rats.

Understanding the role of cell death in burn wound progression is crucial for giving appropriate diagnoses and designing therapy regimens for burn patients. A well-described and reliable "comb burns model" was employed to evaluate the roles of autophagy and apoptosis in burn wound progression at 2 h, 6 h, 12 h, 24 h, and 48 h post-burn in a rat model. Immunohistochemistry (IHC) results showed that autophagy was detectable in hair follicle epithelium at 2 h post-burn, peaked at 12 h post-burn, then declined. Conversely, apoptosis was mainly located in the stratum epidermis and took place at low levels until 6 h post-burn, at which point it slowly increased. Bcl-2 and Bax, which are regulators of both processes, showed protein expression level patterns that were consistent with the IHC results. This study of autophagy in burn wound tissue progression represents a conceptual expansion of cell death in burn wounds. Based on these results, we suggest that different treatments should be performed on a specific post-burn time course depending on the most prevalent type of cell death occurring at that time.

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.

Autologous nerve implantation into denervated monkey skin promotes regeneration of Meissner's corpuscle.

BACKGROUND: The aim of this study was to observe the effects of autologous nerve implantation into the denervated finger flap on the regression and regeneration of sensory nerve endings and Meissner's corpuscles. MATERIAL/METHODS: Bilateral nerves of fingers were separated: one was removed and the other was implanted into the denervated finger in the implantation group. In the non-implantation group, both nerves were removed. The ventral skin of fingers was collected for immunohistochemistry and electron microscopy 3, 6, 9 and 12 months after surgery. RESULTS: The nerve endings in the Meissner's corpuscles began to degenerate 3 months after denervation. The elementary structure of Meissner's corpuscles was not significantly altered. Nerve fibers were present around the Meissner's corpuscles, accompanied by growing into its inward. The axons in the denervated nerve disappeared and the Meissner's corpuscles began to atrophy at month 6. More regenerated nerve fibers were observed after nerve implantation, including intensive and thick fibers, accompanied by reinnervation of Meissner's corpuscles. More nerve fibers and a higher proportion of myelinated nerve fibers were noted at month 9 in the implantation group, and the reinnervation was present in the majority of Meissner's corpuscles. Naive myelinated nerve fibers appeared at the caudal end of Meissner's corpuscles. The nerve fibers in the Meissner's corpuscles increased to the normal level at 12 months after nerve implantation. CONCLUSIONS: The implanted nerve regenerated a large amount of free nerve endings, which helped to regenerate simple Meissner's corpuscles via governing previously degenerated corpuscles.

[Regulation of T-type Ca(2+) channel in lysophosphatidylcholine-stimulated cardiomyocytes].

OBJECTIVE: To study the effect of lysophosphatidylcholine (LPC) on T-type calcium channel currents (I(Ca.T)) in cardiomyocytes, and identify the mechanism by which LPC accumulation in intracellular and/or interstitial space may uptake tachycardia and various arrhythmias during cardiac ischemia. METHODS: Neonatal rat cardiomyocytes from 1 to 3-day-old Wistar rats and hypertrophied ventricular myocytes from Wistar rats were prepared. Human cardiac T-type calcium channel α1 subunits, Ca(V3.1) and Ca(V3.2), were stably expressed in HEK293 cells. In this study, cardiomyocytes and heterologous expression of human Ca(V3.1) and Ca(V3.2) components were measureed by whole-cell patch clamp to study the up-regulation of I(Ca.T) by LPC. RESULTS: LPC markedly accelerated the spontaneous beating rates of neonatal rat cardiomyocytes from (42±8) beats/min in control to (64 ±8) beats/min after LPC application for 5 min at the physiological [Ca(2+)](i) concentration (pCa=7.2). In neonatal cardiomyocytes, I(Ca.T) was significantly increased by 10 µmol/L LPC by 21.5% when [Ca(2+)](i) was high (pCa=7). Intracellular Ca(2+)-dependent augmentation of I(Ca.T) by LPC was confirmed not only in neonatal cardiomyocytes but also in adult ventricular myocytes from the hypertrophied hearts. In this experiment, I(Ca.T) was significantly increased by 10 µmol/L LPC by 23.5% when [Ca(2+)](i) was high (pCa=7), although it was unchanged when [Ca(2+)](i) was low (pCa=11), control: (3.8±0.2) pA/pF, n=16; LPC: (3.7±0.4) pA/pF, n=10. LPC exerted no effect on the Ca(V3.1) T-type Ca(2+) channel current (I(Ca(V)3.1)) regardless of the [Ca(2+)](i) concentration at a pCa of 7 or at a pCa of 11. In contrast, LPC up-regulated the Ca(V3.2) T-type Ca(2+) channel current (I(Ca(V)3.2)), which was much larger at a pCa of 7 [LPC=10 µmol/L: (68.8±2.1) pA/pF, n=10; LPC=50 µmol/L: (78.4±4.8) pA/pF, n=9)] than that at a pCa of 11 [(38.5±2.1) pA/pF, n=11]. CONCLUSION: The present study indicates that LPC up-regulates the cardiac I(Ca.T) in physiological or higher [Ca(2+)](i) concentration, which may accelerate the pathophysiological cardiac automaticity and trigger tachyarrhythmias as novel ischemia-related mechanism.

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.

[Observation on the fluid resuscitation and the change in blood sodium of severely burned patients in the early stage].

OBJECTIVE: To study the necessary amount of fluid consisting of electrolyte and colloid, the ratio of electrolyte and colloid used, and the change of blood sodium during early resuscitation in severely burned patients. METHODS: Sixty-seven patients with total burn surface area (TBSA) equal to or over 70% and full-thickness area equal to or over 50%TBSA, hospitalized from March 2004 to March 2009, were resuscitated with fluid. The infusion amount of electrolyte, colloid, and water, and urinary output of patients at post injury hour (PIH) 24, 48, and 72 were analyzed retrospectively. The variation in blood sodium and fluid infusion at different time points was recorded. Data were processed with SPSS 13.0 software. RESULTS: Among the 67 patients, hyponatremia occurred in 9 cases, hypernatremia occurred in 5 cases, and 53 patients had normal blood sodium level. The urinary output of patients within PIH 72 was above 70 mL/h. K value was calculated through the formula: actual total infusion amount of electrolyte and colloid (mL) = burn area (%TBSA) x body weight (kg) x K. In the first 24 PIH, K value was about 1.7, and the ratio of electrolyte and colloid was 1.4. In the second 24 PIH, K value was about 1.3 with electrolyte and colloid ratio 1.6. K value in the third 24 PIH was about 0.9 with electrolyte and colloid ratio 2.0. CONCLUSIONS: The actual amount of resuscitation fluid is slightly larger than that calculated from traditional formula during the early stage in severely burned patients. The amount of electrolytes and the proportion of electrolyte and colloid will influence blood sodium level of patients.

[Therapeutic effect of vacuum-assisted closure technology on infected explosion wound of pig].

OBJECTIVE: To investigate the effect of vacuum-assisted closure (V. A. C.) technology in the treatment of infected wound of skin and soft tissue as a result of explosion injury in pig. METHODS: Sixteen explosion wounds were established by electric detonators on the shoulders and hips on both sides of 4 small white domestic pigs ,and they were divided into A group [(without treatment and infection occurred on 1-2 post burn day (PBD), then treated with vaseline gauze on 3 (PBD)], and B group (with the same treatment as in A group, except for treatment of vacuum assisted closure (V. A. C) with pressure of - 15 kPa after 3 PBD). The data of wound depth, wound area, wound healing time were collected and analyzed at 3 PAD and 1, 3, 6, 9, 14, 19, 24 days after treatment. Specimens from wounds were collected for histopathology observation, including also cell proliferation index, the number of vascular endothelial cells, the activity of myeloperoxidase (MPO) and the number of bacteria. RESULTS: Compared with those in A group on land 3 days after treatment, wound area, wound depth were not enlarged or deepened in B group, while the number of inflammatory cells, vascular endothelial cells, proliferative cells were increased, the activity of MPO was enhanced and the number of bacteria was decreased. There were obvious differences between two groups in following indices: wound area ,wound depth, the number of vascular endothelial cells and bacteria during 1 to 19 days after treatment (P < 0.01)), the number of cell proliferation from 1 - 9 days after treatment (P < 0.01)), and the activity of MPO on 3, 6 days after treatment (P < 0. 01). The wound healing time was (32.8 +/- 1.6) d in A group, which was longer than that in B group (25.8 +/- 1.0 d, P < 0.01). CONCLUSION: Compared with conventional dressing change, V. A. C can decrease bacteria load, lessen secondary necrosis, prompt the inflammatory response, accelerate the formation of granulation tissue, shorten wound healing time in infectious wound of porcine skin and soft tissue resulted from explosion injury.

[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.

[Effect of strengthening Pi and activating blood circulation therapy on serum levels of adrenocorticotrophic hormone and vascular endothelial growth factor in rheumatoid arthritis patients].

OBJECTIVE: To observe the effect of strengthening Pi and activating blood circulation therapy (SPAB) on serum levels of adrenocorticotrophic hormone (ACTH) and vascular endothelial growth factor (VEGF) in rheumatoid arthritis (RA) patients. METHODS: Seventy RA patients were randomly assigned to 3 groups. The 30 in the Chinese medicine (CM) group were treated with SPAB; the 20 in the Western medicine (WM) group were treated with indomethacin and methopterin; and the 20 in the CM-WM group were treated with the combination of the therapy in the above two groups, and the course of treatment was 3 months for all. Serum levels of ACTH and VEGF were determined before and after treatment. RESULTS: The total effective rate in the CM group was 80.0%, WM group 85.0% and CM-WM group 95.0%, the last one showed the best efficacy (P<0.05). Serum level of ACTH increased and level of VEGF decreased after treatment in all groups (P<0.05 or P<0.01), but the increment/decrement in the CM-WM group was higher than that in the other two groups (P<0.01), while comparison between that in the CW group and WM group showed insignificant difference. CONCLUSION: SPAB therapy has the effect in alleviating the condition of RA, similar to that of Western medicine, it can increase the serum level of ACTH and decrease the serum level of VEGF remarkably in RA patients.

Effects of vacuum-assisted closure on wound microcirculation: an experimental study.

OBJECTIVE: To study the mechanism through which vacuum-assisted closure (VAC) induces an increase in blood flow and reduces oedema on skin wounds. METHODS: Thirty-two Japanese large-ear white rabbits were used. A round full-thickness skin defect (retaining the perichondrium), 2 cm in diameter, was created on each dorsal ear. The wound on the left ear was assigned to the experimental group, and the wound on the right ear to the control group. In the experimental group, the sterile foam dressing was trimmed to the appropriate size and geometry for the given wound and placed into the wound defect. The surface of the wound containing the foam dressing was covered with an adhesive drape to create an airtight seal. Afterwards, negative pressures of -5, -10, -15 and -20 kPa were exerted on the same wound, each lasting for 20 minutes, at intervals of 10 minutes. In the control group, the wound was treated with petrolatum gauze only. At different time points, the microcirculation microscope and image pattern analysis were used to observe the variation in wound microcirculation through a detective window. RESULTS: It was found that VAC promoted capillary blood flow velocity, increased capillary calibre and blood volume, stimulated endothelial proliferation and angiogenesis, narrowed endothelial spaces, and restored the integrity of the capillary basement membrane. CONCLUSION: By increasing capillary calibre and blood volume and by stimulating angiogenesis, VAC could improve blood circulation in wounds. By narrowing endothelial spaces and by restoring the integrity of capillary basement membranes, VAC could decrease the permeability of blood vessels and wound oedema.

[500 cases of external ultrasound-assisted liposuction].

OBJECTIVE: To discuss the therapeutic effects and safety of external ultrasound-assisted liposuction and to find out the rules of circumference variation in different body areas after liposuction. METHODS: External ultrasound liposuction was performed on 500 patients (595 sites). We recorded the volume of anesthetic drugs and the aspirated pure fat as well as the body contour variations of every area at one to three months postoperatively. The decreased dimension at different body sites after liposuction were compared and analyzed. RESULTS: The volumes of the anesthetic liquid and the aspirated pure fat were the most in the waist-abdomen and the thigh. After liposuction, the circumstances in different body areas were all decreased to certain degrees. Along with the severity of obesity, changes in the waist-abdomen became more obvious and the decreases of the umbilical circumference, the minimum and the maximum waist circumferences were prone to be less. But when the, minimum waist circumference was over 111 cm, obvious changes occurred in the umbilical. Meanwhile, the upper-middle part of the thigh and the upper arm showed larger variations than the lower part. The ultrasound-assisted liposuction had less blood loss and pain. It resulted in smooth skin without severe complications. CONCLUSIONS: External ultrasound-assisted liposuction is a safe, effective and easily acceptable operation for body contour remodeling. The body circumference variation may have its intrinsic rule, which, to some extent, is meaningful for conducting clinical inquiry and forecasting the operation results.