[Phase Ⅳ clinical trial for external use of recombinant human granulocyte-macrophage colony-stimulating factor gel in treating deep partial-thickness burn wounds]

OBJECTIVE

To evaluate the clinical efficacy and safety of external use of recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) gel on deep partial-thickness burn wounds.

METHODS

Sixty-eight hospitals in our country including our unit performed a phase Ⅳ clinical trial for rhGM-CSF gel in patients (conforming to the study criteria) with deep partial-thickness burn wounds from November 2010 to July 2012. Multicenter, randomized, positive-homogenous-controlled, and open trial method was used in the trial, and patients from 10 hospitals were grouped into the positive-homogenous-controlled trial, while patients from the other 58 hospitals were grouped into open trial. (1) Controlled trial. Patients were divided into rhGM-CSF group and conventional treatment group (CT) with the ratio of 1∶1 according to the stratified randomization method. Wounds of patients in rhGM-CSF group were coated with rhGM-CSF gel, and wounds of patients in group CT were covered by gauze with iodophor. Scores of wound exudate and wound edge response before treatment and on treatment day (TD) 2, 4, 8, 10, 14, 20, and 28 were conventionally evaluated. Wound healing rates on TD 8, 10, 14, 20, and 28 were calculated. Complete wound healing time and overall efficiency including cure, excellence, progress, and invalid situation on TD 28 were recorded. Safety indexes including vital signs and laboratory test indexes before and during treatment, and adverse reactions during treatment were observed. (2) Open trial. Wounds of patients in this trail were all coated with rhGM-CSF gel. Complete wound healing time, overall efficiency, and safety indexes of patients were recorded as in controlled trial. Data were processed with CMH-χ(2) test, Fisher's exact test, signed rank sum test, paired t test, Log-Rank test, and Wilcoxon rank sum test.

RESULTS

(1) Controlled trail. A total of 366 patients from 10 hospitals were included in this trial, and 358 cases with 177 cases in rhGM-CSF group and 181 cases in group CT finished the trial. There were no statistically significant differences in gender, age, injury characteristics, and combined medication situation between patients in two groups (χ(2)=1.510, with t values from 0.458 to 0.820, P values above 0.05). Scores of wound exudate of patients in two groups were similar before treatment and on TD 2, 20, and 28 (t=0.420, with Z values from 0.735 to 1.939, P values above 0.05). Scores of wound exudate of patients in rhGM-CSF group were significantly lower than those in group CT on TD 4, 8, 10, and 14 (with Z values from 2.054 to 2.580, P values below 0.05). Scores of wound edge response of patients in two groups were similar before treatment and on each TD (t=0.340, with Z values from -1.147 to 1.874, P values above 0.05). Wound healing rate of patients in rhGM-CSF group was significantly higher than that in group CT on each TD (with Z values from 2.630 to 5.235, P values below 0.01). The complete wound healing time of patients in rhGM-CSF group was (16.93±0.40) d, which was significantly shorter than that in group CT[(19.88±0.41) d, χ(2)=26.732, P<0.001]. At last, 171 (96.61%) patients were completely cured in rhGM-CSF group, while excellence, progress, and invalid results were achieved in 3 (1.69%), 1 (0.56%), and 2 (1.13%) patients, respectively. Whereas, 161 (88.95%) patients were completely cured in group CT, while excellence, progress, and invalid results were achieved in 11 (6.08%), 5 (2.76%), and 4 (2.12%) patients, respectively. Total efficacy of patients in rhGM-CSF group was significantly higher than that in group CT (χ(2)=5.784, P<0.05). Levels of vital signs and laboratory test indexes of patients in two groups before and during treatment were similar. There were no statistically significant differences in adverse reaction or drug-related adverse reaction between patients in two groups during treatment (with P values above 0.05). (2) Open trial. A total of 2 380 patients were enrolled in, and 2 329 patients finished the trial. The complete wound healing time of patients was (16.28±0.10)d. At last, 2 257 (96.91%) patients were totally cured, while excellence, progress, and invalid results were achieved in 36 (1.55%), 16 (0.69%), and 20 (0.86%) patients, respectively. Vital signs and laboratory test indexes of patients before and during treatment were similar. The drug-related adverse reaction was observed in 44 patients (1.89%).

CONCLUSIONS

External use of rhGM-CSF gel on deep partial-thickness burn wounds can promote wound healing and is safe for clinical use.

Gemcitabine inhibits the micrometastasis of non-small cell lung cancer by targeting the EpCAM-positive circulating tumor cells via the HGF/cMET pathway

Recurrence and metastasis are responsible for the death of non-small cell lung cancer (NSCLC) patients. Circulating tumor cells (CTCs) in the metastatic pathway have proven to be essential. This pilot study evaluated the sensitivity of gemcitabine in micrometastasis and CTCs from NSCLC patients. EpCAM-positive CTCs were detected in forty patients with NSCLC at treatment initiation and disease evaluation time-points. EpCAM-positive CTCs were defined as EpCAM-positive and CD45-negative. Total RNA was isolated from EpCAM-enriched CTCs and cytokeratin levels were detected by PCR. The HGF/cMET pathway was evaluated in CTCs from patients with different treatments and in A549 cells. The EMT-related markers were analyzed by IHC. We further explored the predictive value of baseline CTCs in patients that were receiving different treatments. The median number of CTCs in NSCLC patients was 65 CTCs/ml more than in the healthy 23?fold (median, 5.2 CTCs/ml). The mean change in cell count was significantly different for patients with gemcitabine compared to patients with non-gemcitabine treatments (-86.28 vs. -15.23/ml; P<0.05). A significant decrease was noted in the expression of cytokeratin in the CTCs of the two groups (P<0.05). The HGF/cMET pathway was inactivated in CTCs and A549 cells treated with gemcitabine, and the cell migration and invasion abilities were inhibited by gemcitabine via the HGF/cMET pathway. Furthermore, the decreased cell migration and invasion abilities may also be involved in the inhibition of the epithelial-mesenchymal transition (EMT) by gemcitabine. At a median follow-up of 36 months, the CTC count was confirmed to be a robust prognostic marker in the NSCLC population (CTCs >151, median: 15.0 months and CTCs <151, median: 32.0 months). Additionally, the survival rate in the gemcitabine group (24 months) was better than in non-gemcitabine group (21 months), suggesting a therapeutic benefit for NSCLC patient survival with the common therapy plus gemcitabine. Gemcitabine treatment decreased EpCAM-positive CTCs in NSCLC patients and inhibited EMT by the HGF/cMET pathway.

[To intensify our understanding about management of severe burn infection]

Nowadays, it is necessary to emphasize the three basic inseparable elements in the treatment of severe burn infection, which are systemic care, burn wound care, and rational use of antimicrobials topically or systematically. Systemic care has been shifted from simple nutritional support to maintaining the systemic homeostasis, including balancing immune-inflammatory response, and protecting organs from dysfunction. Some work focused on regulating systemic immune response in the initial phase and the balance of inflammatory response after occurrence of severe burn infection have been reported. These results at least broaden our thinking to recognize that treatment should not only destroy microbes, but also balance the response of the body. Escharectomy in earlier phase has been a consensus. Currently, we turn our vision into how to use "damage control surgery (DCS)" concept in management of severe burn. DCS in burn care includes the evaluation of perioperative situation more accurate to make a more appropriate surgical decision. Meanwhile, an overall strategy should be established to confront the rapidly increasing drug resistance of the pathogens. The release of endotoxin after use of antimicrobials, which has been studied widely, should be explored further.

[Effect of recombinant human granulocyte-macrophage colony stimulating factor on wound healing in patients with deep partial thickness burn]

OBJECTIVE

To evaluate the efficacy and safety of recombinant human granulocyte-macrophage colony stimulating factor (rhGM-CSF) hydrogel in wound healing in patients with deep partial thickness burn.

METHODS

The study was a multicenter, randomized, double-blind, placebo-controlled parallel clinical trial. Three hundred and twenty-one patients (302 cases finally fulfilled the protocol) with deep partial thickness burn were divided into A group (n = 200, with treatment of rhGM-CSF hydrogel, 100 microg/10 g/100 cm2/d), C group (n = 102,with treatment of placebo). Side-effect, systemic condition, wound healing time, wound healing rate, and total effective rate at different time points were observed.

RESULTS

There were no obvious differences in vital signs, wound secretion, wound edge reaction, blood and urine routine, liver and kidney function between two groups (P > 0.05). No side-effect was observed. The median wound healing time was 17 days in A group, which was obviously shorter than that in C group (20 days, P < 0.01). The mean wound healing rate in A group was 24.5%, 70.5%, 95.3%, 99.6% respectively on 8th, 14th, 20th, 28th day after treatment, which were obviously higher than that in C group (15.1%, 51.4%, 84.6%, 97.1%, respectively, P < 0.01). The total effective rates in A group on 8th, 14th, 20th day after treatment were also higher than that in C group (P < 0.01).

CONCLUSION

rhGM-CSF hydrogel can significantly accelerate wound healing in patients with deep partial thickness burn with certain safety.

[Study of neovascularization disturbance in deep partial-thickness scald in rats with diabetes mellitus]

OBJECTIVE

To study the relationship between the degree of neovascularization and non-healing wounds in scalded rats with diabetic mellitus.

METHODS

Sixty Sprague-Dawley rats were randomly divided into control group (C, n = 30, with treatment of isotonic saline) and streptozocin (STZ)-induced diabetic group (D, n = 30, with treatment of STZ), and then they were inflicted with 20% TBSA deep partial thickness scald. Wound specimens were harvested immediately after scald and on 1, 3, 7, 10, 14, 21 post scald days (PSD) to observe histological changes, and wound healing rates were calculated. Degree of neovascularization in wound (labeled with blue microsphere) and the quantity of vascular endothelial cells (labeled with red CD31) were also measured by double-labeling immunofluorescence.

RESULTS

Compared with those in C group, Wound healing rate and histological value scores were lowered, and the degree of neovascularization was abated markedly at each time point. The degree of neovascularization in D group (12.00 +/- 1.40) was obviously lower than that in C group on 7 PSD (60.00 +/- 3.00, P <0.01). There was no obvious difference in the number of vascular endothelial cells in both groups, however, the majority of endothelial cells had not formed functional capillaries in D group.

CONCLUSION

Vascular endothelial cell can proliferate actively with poor blood supply in diabetic nonhealing with deep partial-thickness scald wounds, but it is still poor in blood supply due to lack of functional capillaries.

[Influence of tangential excision within 24 postburn hours on the local wound inflammatory response in patients with deep partial thickness burn]

OBJECTIVE

To investigate the influence of early tangential excision within 24 postburn hours on local wound inflammatory response and tissue injury in patients with deep partial thickness burn.

METHODS

Twelve patients with deep partial thickness burn were enrolled in the study. Tangential excision was performed within 24 postburn hours. The same wound of a patient was divided into three areas for harvesting tissue samples, i.e. pre-operation, post-operation and non-operation areas. For each patient, the biopsies from the pre-operation area were harvested before tangential excision, while those from post-operation and non-operation areas were harvested during 5 to 7 postburn days (PBDs). The contents of IL-8, MPO and MDA in wound tissue were determined by tissue culture and chemical colorimetry, respectively. HE and Mason's staining were employed to assess the degree of necrosis of the wound tissue.

RESULTS

The IL-8, MPO and MDA contents in the local wound tissue after tangential excision were 6.83 +/- 1.85 microg/L, 4.07 +/- 0.87 U/g, and 8.94 +/- 5.66 micromol/g, respectively, which were significantly lower than those from non-operation area (P < 0.01). The inflammatory response in the non-operative wound area was distinct with expansion of necrotic tissue area. In contrast, the local inflammatory response of the wound after tangential excision was ameliorated without the enlargement of necrotic tissue area.

CONCLUSION

Tangential excision within 24 postburn hours could be beneficial in ameliorating local inflammatory response, and in preventing progressive deepening of the burn wounds, thus it could accelerate wound healing in patients with deep partial thickness burn.

[The influence of dermal template on the expressions of signal transduction protein Smad 3 and transforming growth factor beta1 and its receptor during wound healing process in patients with deep burns]

OBJECTIVE

To investigate the influence of dermal template on the expressions of signal transduction protein Smad 3 and transforming growth factor beta1 and its receptor during wound healing process in patients with deep burns.

METHODS

Twenty burn patients with excision of full thickness burn in the extremities were enrolled in the study and divided into two groups, i.e. template interfering group (E, n = 20, grafting of dermal template [allogeneic acellular dermal matrix] with razor thin autoskin) and control group (C, n = 20, grafting of razor thin autoskin only). The contralateral side served as the self-control. Tissue samples from the burn wounds were harvested at 1, 2, 3 and 4 post-operative weeks (POW) for immunohistochemistry staining. The positive expression rates of TGF-beta1, TbetaRI, TbetaRII and Smad3 proteins were determined by image analysis system.

RESULTS

The positive expressions of TGFbeta1, TbetaRI, TbetaRII and signal transduction protein Smad 3 in the tissue samples in both groups could be identified during 1 approximately 4 POW, and they diminished thereafter with the process of wound healing. The expression rate of TGF-beta1 in E group was (13.08 +/- 4.65)% at 1 POW and (9.03 +/- 1.89)% at 4 POW. The positive expression rate of above indices in E group was obviously lower than that in C group in corresponding time points (P < 0.05).

CONCLUSION

The expression levels of TGFbeta1, TbetaRI, TbetaRII and Smad 3 protein in deep burn wounds could be lowered by mixed grafting of dermal template with razor thin autoskin, which might be beneficial in ameliorating of scar hyperplasia in the burn wound.