Impact of wildfire ash on skin and gut microbiomes and survival of Rana dybowskii.

Climate change and human activities escalate the frequency and intensity of wildfires, threatening amphibian habitats and survival; yet, research on these impacts remains limited. Wildfire ash alters water quality, introduces contaminants, and may disrupt microbial communities, impacting gut and skin microbiota; however, the effects on gut and skin microbiota remain unclear. Rana dybowskii were exposed to five concentrations (0 g L-1, 1.25 g L-1, 2.5 g L-1, 5 g L-1, and 10 g L-1) of aqueous extracts of wildfire ashes (AEAs) for 30 days to assess AEAs' metal content, survival, and microbiota diversity via Illumina sequencing. Our results showed that the major elements in ash were Ca > K > Mg > Al > Fe > Na > Mn, while in AEA they were K > Ca > Na > Mg > As > Al > Cu. A significant decrease in amphibian survival rates with increased AEA concentration was shown. The beta diversity analysis revealed distinct shifts in microbiota composition. Notably, bacterial genera associated with potential health risks showed increased abundance in skin microbiota, emphasising the potential for ash exposure to affect amphibian health. Functional prediction analyses revealed significant shifts in metabolic pathways related to health and disease, indicating that wildfire ash exposure may influence amphibian health through changes in microbial functions. This study highlights the urgent need for strategies to mitigate wildfire ash impacts on amphibians, as it significantly alters microbiota and affects their survival and health.

Rice straw ash and amphibian health: A deep dive into microbiota changes and potential ecological consequences.

Rice straw is burned as a result of agricultural practices and technical limitations, generating significant volumes of ash that might have environmental and ecological consequences; however, the effects on organisms have not been researched. Amphibians depend on their gut and skin microbiomes. Ash exposure may cause inflammation and changes in microbial diversity and function in frogs' skin and gut microbiota due to its chemical composition and physical presence, but the implications remain unclear. Rana dybowskii were exposed to five aqueous extracts of ashes (AEA) concentrations for 30 days to study survival, metal concentrations, and microbial diversity, analyzing the microbiota of the cutaneous and gut microbiota using Illumina sequencing. Dominant elements in ash: K > Ca > Mg > Na > Al > Fe. In AEA, K > Na > Ca > Mg > As > Cu. Increased AEA concentrations significantly reduced frog survival. Skin microbiota alpha diversity varied significantly among all treatment groups, but not gut microbiota. Skin microbiota differed significantly across treatments via Bray-Curtis and weighted UniFrac; gut microbiota was only affected by Bray-Curtis. Skin microbiota varied significantly with AEA levels in Proteobacteria, Bacteroidetes, Actinobacteria, and Firmicutes, while the gut microbiota's dominant phyla, Firmicutes, Bacteroidetes, and Proteobacteria, remained consistent across all groups. Lastly, the functional prediction showed that the skin microbiota had big differences in how it worked and looked, which were linked to different health and environmental adaptation pathways. The gut microbiota, on the other hand, had smaller differences. In conclusion, AEA exposure affects R. dybowskii survival and skin microbiota diversity, indicating potential health and ecological impacts, with less effect on gut microbiota.

Characteristics and a comparison of the gut microbiota in two frog species at the beginning and end of hibernation.

Season has been suggested to contribute to variation in the gut microbiota of animals. The complicated relationships between amphibians and their gut microbiota and how they change throughout the year require more research. Short-term and long-term hypothermic fasting of amphibians may affect gut microbiota differently; however, these changes have not been explored. In this study, the composition and characteristics of the gut microbiota of Rana amurensis and Rana dybowskii during summer, autumn (short-term fasting) and winter (long-term fasting) were studied by high-throughput Illumina sequencing. Both frog species had higher gut microbiota alpha diversity in summer than autumn and winter, but no significant variations between autumn and spring. The summer, autumn, and spring gut microbiotas of both species differed, as did the autumn and winter microbiomes. In summer, autumn and winter, the dominant phyla in the gut microbiota of both species were Firmicutes, Proteobacteria, Bacteroidetes, and Actinobacteria. All animals have 10 OTUs (>90% of all 52 frogs). Both species had 23 OTUs (>90% of all 28 frogs) in winter, accounting for 47.49 ± 3.84% and 63.17 ± 3.69% of their relative abundance, respectively. PICRUSt2 analysis showed that the predominant functions of the gut microbiota in these two Rana were focused on carbohydrate metabolism, Global and overview maps, Glycan biosynthesis metabolism, membrane transport, and replication and repair, translation. The BugBase analysis estimated that among the seasons in the R. amurensis group, Facultatively_Anaerobic, Forms_Biofilms, Gram_Negative, Gram_Positive, Potentially_Pathogenic were significantly different. However, there was no difference for R. dybowskii. The research will reveal how the gut microbiota of amphibians adapts to environmental changes during hibernation, aid in the conservation of endangered amphibians, particularly those that hibernate, and advance microbiota research by elucidating the role of microbiota under various physiological states and environmental conditions.

[Repair of devastating wounds with free composite tissue flap].

OBJECTIVE: To study the safety and effects of free composite tissue flaps in repairing devastating wounds in early stage. METHODS: One hundred and twenty-three patients with 128 devastating wounds hospitalized in our burns center from 2005 to 2009 were repaired with free flaps or composite tissue flaps. Flap types used included 58 latissimus dorsi muscular flaps, 32 anterolateral thigh flaps, 21 circumflex scapular flaps, 6 dorsalis pedis composite flaps, 3 big toe nail skin flaps, 3 forearm flaps, and 1 lateral thoracic flap. One wound was repaired with lateral lower leg flap with fibula, and 3 wounds with free latissimus dorsi muscular flap plus skin graft. RESULTS: Vascular crisis was observed in 10 transplanted flaps 1 to 5 days after operation; 6 flaps with this complication were saved after emergency surgical exploration. Total survival rate of transplanted flaps and composite tissue flaps was 95.3% (122/128). All patients were followed up for 3 months to 4 years; satisfactory appearance and restoration of partial function were found in all of them. CONCLUSIONS: Free composite tissue transplantation reduces amputation rate, achieves primary reconstruction of function with good appearance, shortens length of hospital stay, and reduces surgical operation time, complications, and treatment cost. It is a good approach in the repair of massive devastating soft tissue injury.

[Microsurgical repair of skin and soft tissue defects on head, face, and neck].

OBJECTIVE: To study the microsurgical method of repairing skin and soft tissue defects on head, face, and neck. METHODS: Thirty-one patients with skin and soft tissue defects on the head, face, or neck were hospitalized from July 2007 to May 2010, including 10 cases of scalp defects, 4 cases of skin and soft tissue defects on face, and 17 cases of skin and soft tissue defects on neck. Among them, the cause in 20 cases was trauma, and in 11 cases they were secondary to release of cicatricial contraction. Free flaps were transplanted to repair the wounds, including 13 latissimus dorsi flaps, 3 lateral thoracic flaps, 5 scapular flaps, and 10 anterolateral thigh flaps. The area of flaps ranged from 8 cm × 5 cm to 25 cm × 18 cm. RESULTS: All flaps survived, and all the wounds healed by first intention. The average length of hospital stay was 16.7 days. Twenty-eight patients were followed up for 2 months, and in all of them satisfactory function and appearance were restored. CONCLUSIONS: Free flap graft based on microsurgery can repair wound of skin and soft tissue defects on head, face and neck by a single operation, which eases suffering of patients, and shortens the length of hospital stay.

[Surgical therapy for massive deep skin and soft tissue injuries].

OBJECTIVE: To explore the methods of repair of massive deep skin and soft tissue injuries. METHODS: Fifty-six patients with deep skin and soft tissue injuries were hospitalized from July 2006 to January 2008. Among them, 23 cases were caused by burn, 17 cases by electric injury, 7 cases by hot crush injury, 6 cases by avulsion injury, and 3 cases due to other reasons (including traffic accident, crush injury, soft tissue infection respectively). Sixty-five skin flaps were raised to repair and reconstruct the injured tissues, including 21 local flaps, 18 distant pedicled skin flaps, and 26 free skin flaps. The area of skin flaps ranged from 1.5 cm x 1.0 cm to 39.0 cm x 23.0 cm. RESULTS: Sixty skin flaps survived completely, partial necrosis occurred in 3 flaps, and complete necrosis in 2 flaps. There was no obvious difference in average survival rate among local skin flaps (95.2%), distant pedicled skin flaps (88.8%), and free skin flaps (92.3%, P > 0.05). CONCLUSIONS: Skin flap transposition can be still considered as the major effective method in repair of massive deep skin and soft tissue injury. On the premises of high survival rate, free skin flap transposition can be considered as the first choice.

[Functional reconstruction of multiple severe deformities after extensive deep burn].

To explore new measures for functional reconstruction of multiple severe deformities as a result of extensive deep burn (total burn surface area > or = 90% TBSA, including deep burn > or = 70%TBSA) in late stage. Twelve severe burn patients with above-mentioned deformities were hospitalized in our ward during 1960--2005, the scars resulted from burns were distributed from head to foot with 173 deformities, including 27 scar ulcers. All patients lacked of self-care ability, among them some could not stand. Due to inadequate skin source, deformities were corrected by skin from matured scars expanded with subcutaneous balloon at late postburn stage. Following our former clinical experience, anatomic investigation and experimental research, we chose the following methods to correct deformities and restore functions: application of split-thickness scar skin after expansion (88 wounds); use of scar skin flap/scar-Achilles tendon flaps (59 wounds); combination of thin split-thickness skin grafts from scar and allogeneic acellular dermal matrix (composite skin, 40 wounds). All grafts survived, the appearance and function were improved obviously without complications. Follow-up 1-40 years, all patients could take care themselves with satisfactory function and appearance, and among them 8 patients returned to work (one had worked for 40 years), 2 patients married and had children. The above-mentioned measures are safe, reliable and effective for functional reconstruction of deformities.

[Evaluation and surgical treatment for chronic wound of leg and foot].

OBJECTIVE: To investigate the optimal operation method for the management of various chronic wounds in legs and feet. METHODS: Fifty-one chronic wounds were evaluated according to infection, inflammatory response, and distribution in different areas of the leg and foot. Preoperative treatment was given accordingly, then transposition of skin flap, skin grafting, or amputation was performed. The healing rate after single session operation and average hospitalization were statistically analyzed. RESULTS: The wound healing rate after single session operation was 86. 3% , the average hospital stay was (17. 8 +/- 2. 1) days, and the appearance and function of the leg and foot after operation was satisfactory. CONCLUSION: The appropriate preoperative treatment and operation method conforming to the wound location and evaluation are of vital importance in the management of chronic wounds in the leg and foot. Operation is one of the most effective ways to repair chronic wounds in the leg and foot, and it can shorten the wound healing process and restore the function.

Expression of human beta-defensin 3 in COS-7 cell.

OBJECTIVE: To establish a cell line for stable expression of human beta-defensin 3 (hBD3). METHODS: Full length cDNA of hBD3 was isolated from previously constructed pGEM-hBD3 and then inserted into pcDNA3. The recombinant vector identified carrying hBD3 with right direction was introduced into COS-7 cells by Lipofectamine. Cell clones survived in G418-rich medium and with stable expression of hBD3 in both mRNA and protein levels were identified by RT-PCR and Western blot respectively. Genomic integration of the hBD3 gene with the COS-7 cells was confirmed by Southern dot blot and primary analysis. The antimicrobial activity of the secreted hBD3 was also evaluated. RESULTS: COS-7 cells transfected with pcDNA3-hBD3 expressed hBD3 stably in mRNA and protein level. Southern dot blot analysis showed successful integration of the hBD3 gene into the genome of COS-7 cell and the hBD-3 protein secreted into the culture medium showed antimicrobial activity. CONCLUSION: We successfully established a hBD3-expressing cell line.

[Establishment of rat model of scalding with high pressure steam].

OBJECTIVE: To establish a rat model of scalding with controllable depth and area by high pressure steam. METHODS: High pressure steam apparatus consisting of an autoclave and a self-made scalding frame was employed in the study. The rats were inflicted with scalding with 0.12 Mpa (1 Mpa = 7500 mmHg) high pressure steam on the back through a hole of 2.6 cm in diameter for 3, 4, 5, 6, 7, 8, 9 and 10 seconds, with five wounds at each time point. The tissue samples were harvested at 24 post injury hour (PIH) for pathomorphological examination. The depth of scald was measured, and injury to the sweat gland and hair follicles injury, the hair growth in scalded area, and the wound healing condition were observed with Photoshop software. RESULTS: There was positive correlation between the scalding depth and scalding time. The injury time for superficial and deep partial thickness burn and full thickness burn were 3, 5 and 7 seconds respectively. The wound healing time was similar even the scalding became more and more serious when injury time increased from 7 to 10 seconds. CONCLUSION: The scalding depth and area in this model could be controlled, and the degree of scald injury could be graded accurately with easy manipulation. The result showed that it was an ideal model of skin burn wound.

[Experimental study and clinical application of composite skin grafting].

OBJECTIVE: To explore an ideal skin substitute with its appearance and texture similar to normal skin, to repair wounds with full-thickness skin defect. METHODS: Composite skin (CS) in question was composed of allo/xenogeneic acellular dermal matrix (ADM) and razor thin autoskin. One step skin grafting was employed in the experimental study and clinical trial. Razor thin autoskin alone was used as the control in the study. Changes in the antigenicity of ADM and the reformation of basement membrane (BM) structure at epidermis-dermis junction (EDJ) of ADMs were studied at designated time points after the grafting with biochemical and immunohistochemical methods. Fifty-three patients with full thickness skin defects due to various causes, including scar excision were grafted with CS, and survival rate and long-term result were observed. RESULTS: The grafted CS survived satisfactory. The reformation of the basement membrane structure was clearly observed at the 28th post-graft week. The basement membrane cells grew with polarization in an undulating arrangement. There was reformation of dermal papillae and ridges. The antigenicity of allo-ADM was obviously lower than that of xeno-ADM. Sixty-five out of 70 pieces of CS grafting (92.9%) survived totally, two of them survived partially, and three failed due to infection. The longest follow-up period was 8 and a half years. The grafted CS appeared similar to the normal skin in regard to the texture and color, especially allo-ADM, and no evident rejection reaction was seen. CONCLUSION: ADM possessed very low antigenicity, thus serving a lasting framework after grafting. In addition, it could serve as a "dermal template" for the induction of tissue regeneration.

[An experimental study on the change in neuropeptide substance P in the burn wound skin in scalded rats].

OBJECTIVE: To investigate the change in neuropeptide substance P (SP) in the burn wound skin in scalded rats. METHODS: The SP distribution density in the rat skin samples from the burn wound, peri-wound area and remote area of scalded rats were determined by immunohistochemistry technique. The mRNA expression of SP was observed by in situ hybridization. RESULTS: The distribution density of SP in the skin samples from the above three areas decreased obviously since 15 mins postburn, dropped to the lowest level during 6 - 12 postburn hou (PBH), and then recovered thereafter. Comparatively, the recovery in peri-wound area occurred earlier. In addition, there was emigration of macrophage-like large cells with positive SP immunoreactivity from local blood vessels in the dermal layer of the burn wound and peri-wound areas. The large cells were closely related to the local SP-containing nerve fibres at 12 PBHs. Intensified staining of the cells was identified at 24 PBHs with the disintegration of the cells into pieces with release of large amounts of positive SP immunoreactive granules, followed by disappearance of the cells at 48 PBHs. It was indicated by in situ hybridization that the preprotachykinin A (PPTA) mRNA encoding and synthesizing SP was expressed in various cells at 6 PBHs. CONCLUSION: SP might be synthesized and released from cutaneous nerve ending or from local inflammatory cells after skin burn injury.

[Long-term in vitro culture of the fibroblasts from the deep partial thickness burn wound in burn patients].

OBJECTIVE: To establish a long-term in vitro culture of the fibroblasts obtained from burn wounds. METHODS: Skin samples were harvested from normal volunteers and the deep partial thickness burn wound in burn patients on the 5th, 10th, 21st, 28th and 35th postburn days (PBDs). The non-dermal tissue was removed from the samples and primed by chlorhexidine solution in concentration of 2.5 g/L. The skin sample was then digested by trypsin-EDTA in concentration of 1.25 g/L and was centrifuged before the cells were harvested and cultured. When the cells grew nearly to form sheet, multiple passage culture, freezing storage and revivification were carried out with routine methods. The cell morphology was continuously observed during the culture. And the cell doubling time was calculated. RESULTS: The wound-origin fibroblasts exhibited higher purity and better activity. The cellular growth features and gross morphology kept stable during primary and secondary culture, and during freezing storage and after revivification. The cells kept their activity above 80% of their original after many times of revivification. CONCLUSION: The establishment of the in vitro culture of fibroblasts from burn wounds might be useful in the exploration of the pathogenesis and therapeutic measures of scars.

[Repair of contracture deformities of the patients with extremely limited donor skin at late postburn stage].

OBJECTIVE: To explore new methods to repair postburn contracture deformities in patients with extremely limited donor skin. METHODS: Five severely burned patients with extremely limited donor skin but severe deformities were enrolled in the study. The mature and the pliable scarred skin was utilized as the donor site for reconstruction of the postburn deformities. Split-thickness scarred skin was harvested for repair of postburn deformities after the scarred skin was expanded by expander, while thin razor-thin scarred skin with allo-acellular dermal matrix (ADM) was employed for the repair of postburn deformities when skin expansion was not feasible. RESULTS: All the expanded scarred skin and composite skin grafts survived completely with good function and configuration. The long-term follow-up result was satisfactory, and the grafted skin was similar to that with split-thickness skin grafting. CONCLUSION: It is feasible to employ various split-thickness scarred skin for the reconstruction of postburn deformities. This technique is a new effective procedure for the reconstruction of postburn deformities, especially for those with extreme scarcity of donor site.