Exploring Thermal Dynamics in Wound Healing: The Impact of Temperature and Microenvironment.

Exploring the critical role of thermal dynamics in wound healing, this manuscript navigates through the complex biological responses initiated upon wound infliction and how temperature variations influence the healing trajectory. Integrating biothermal physics, clinical medicine, and biomedical engineering, it highlights the significance of thermal management in wound care, emphasizing the wound microenvironment's division into internal and external domains and their collaborative impact on tissue repair. Innovations in real-time wound temperature monitoring, especially through intelligent wireless sensor dressings, are spotlighted as transformative, enabling precise wound condition management. The text underscores the necessity for further research to elucidate thermal regulation's molecular and cellular mechanisms on healing processes. It advocates for standardized protocols for localized heating treatments, integrating them into personalized wound care strategies to enhance therapeutic outcomes, improve patient well-being, and achieve cost-effective healthcare practices. This work presents a forward-looking perspective on refining wound management through sophisticated, evidence-based interventions, emphasizing the interplay between thermal dynamics and wound healing.

Risk Factors for Tissue Expander-Related Infections in Pediatric Scar Reconstruction: A 10-Year Retrospective Study.

BACKGROUND: Tissue expansion addresses limited soft tissue availability and provides natural-looking skin for scar reconstruction. However, infection is a common complication in expander surgeries. This 10-year retrospective cohort study aims to investigate the infection risk factors in pediatric scar reconstruction. METHODS: This single-center observational cohort study was conducted at the Central Hospital Affiliated with Shandong First Medical University, China, and analyzed data from pediatric patients undergoing tissue expander surgeries for scar reconstruction from January 2012 to June 2022. Patients were carefully selected, and after grouping into infection and non-infection categories, their demographic and clinical data were analyzed. Propensity score matching (PSM) ensured balanced comparisons, and logistic regression identified infection risk factors. RESULTS: Among the 4,539 patient records, 1,756 eligible pediatric patients were included (142 with infections, 1,614 without). Multivariate analysis revealed that factors increasing infection risk included having three or more expanders (OR: 2.39, P < 0.05), a total expander volume of 300 cc or more (OR: 2.33, P < 0.05), back or gluteal implants (OR: 1.33, P < 0.05), lack of antibiotic prophylaxis (OR: 0.65, P < 0.05), and absence of hematoma evacuation (OR: 3.29, P < 0.05). Microbiological analysis found no significant bacterial differences among antibiotic prophylaxis groups, with Staphylococcus aureus being the predominant bacterium in infections. CONCLUSIONS: Patients with multiple expanders, larger expander volumes, back or gluteal implants, lack of antibiotic prophylaxis, and hematoma evacuation absence have higher infection risks. Short-term (< 24h) use of Staphylococcus aureus-sensitive antibiotics post-surgery may benefit pediatric infection risk reduction.

Transcriptome analysis of the transition from primary to secondary growth of vertical stem in Eucalyptus grandis.

Eucalyptus was one of the most cultivated hardwood species worldwide, with rapid growth, good wood properties and a wide range of adaptability. Eucalyptus stem undergoes primary growth (longitudinal growth) followed by secondary growth (radial growth), which produces biomass that is an important source of energy worldwide. In order to better understand the genetic regulation of secondary growth in Eucalyptus grandis, Transcriptome analyses in stem segments along a developmental gradient from the third internode to the eleventh internode of E. grandis that spanned primary to secondary growth were carried out. 5,149 genes that were differentially expressed during stem development were identified. Combining the trend analysis by the Mfuzz method and the module-trait correlation analysis by the Weighted Gene Co-expression Network Analysis method, a total of 70 differentially expressed genes (DEGs) selected from 868 DEGs with high connectivity were found to be closely correlated with secondary growth. Results revealed that the differential expression of these DEGs suggests that they may involve in the primary growth or secondary growth. AP1, YAB2 TFs and EXP genes are highly expressed in the IN3, whereas NAC, MYB TFs are likely to be important for secondary growth. These results will expand our understanding of the complex molecular and cellular events of secondary growth and provide a foundation for future studies on wood formation in Eucalyptus.

Exogenous applications of brassinosteroids promote secondary xylem differentiation in Eucalyptus grandis.

Brassinosteroids (BRs) play many pivotal roles in plant growth and development, especially in cell elongation and vascular development. Although its biosynthetic and signal transduction pathway have been well characterized in model plants, their biological roles in Eucalyptus grandis, a major hardwood tree providing fiber and energy worldwide, remain unclear. Here, we treated E. grandis plantlets with 24-epibrassinolide (EBL), the most active BR and/or BR biosynthesis inhibitor brassinazole. We recorded the plant growth and analyzed the cell structure of the root and stem with histochemical methods; then, we performed a secondary growth, BR synthesis, and signaling-related gene expression analysis. The results showed that the BRs dramatically increased the shoot length and diameter, and the exogenous BR increased the xylem area of the stem and root. In this process, EgrBRI1, EgrBZR1, and EgrBZR2 expression were induced by the BR treatment, and the expressions of HD-ZIPIII and cellulose synthase genes were also altered. To further verify the effect of BRs in secondary xylem development in Eucalyptus, we used six-month-old plants as the material and directly applied EBL to the xylem and cambium of the vertical stems. The xylem area, fiber cell length, and cell numbers showed considerable increases. Several key BR-signaling genes, secondary xylem development-related transcription factor genes, and cellulose and lignin biosynthetic genes were also considerably altered. Thus, BR had regulatory roles in secondary xylem development and differentiation via the BR-signaling pathway in this woody plant.

Profiling of the gene expression and alternative splicing landscapes of Eucalyptus grandis.

Eucalyptus is a widely planted hardwood tree species due to its fast growth, superior wood properties and adaptability. However, the post-transcriptional regulatory mechanisms controlling tissue development and stress responses in Eucalyptus remain poorly understood. In this study, we performed a comprehensive analysis of the gene expression profile and the alternative splicing (AS) landscape of E. grandis using strand-specific RNA-Seq, which encompassed 201 libraries including different organs, developmental stages, and environmental stresses. We identified 10 416 genes (33.49%) that underwent AS, and numerous differentially expressed and/or differential AS genes involved in critical biological processes, such as primary-to-secondary growth transition of stems, adventitious root formation, aging and responses to phosphorus- or boron-deficiency. Co-expression analysis of AS events and gene expression patterns highlighted the potential upstream regulatory role of AS events in multiple processes. Additionally, we highlighted the lignin biosynthetic pathway to showcase the potential regulatory functions of AS events in the KNAT3 and IRL3 genes within this pathway. Our high-quality expression atlas and AS landscape serve as valuable resources for unravelling the genetic control of woody plant development, long-term adaptation, and understanding transcriptional diversity in Eucalyptus. Researchers can conveniently access these resources through the interactive ePlant browser (https://bar.utoronto.ca/eplant_eucalyptus).

Physiological and molecular mechanisms of Acacia melanoxylon stem in response to boron deficiency.

Boron is an essential micronutrient for plant growth as it participates in cell wall integrity. The growth and development of Acacia melanoxylon stem can be adversely affected by a lack of boron. To explore the mechanism of boron deficiency in A. melanoxylon stem, the changes in morphological attributes, physiological, endogenous hormone levels, and the cell structure and component contents were examined. In addition, the molecular mechanism of shortened internodes resulting from boron deficiency was elucidated through transcriptome analysis. The results showed that boron deficiency resulted in decreased height, shortened internodes, and reduced root length and surface area, corresponding with decreased boron content in the roots, stems, and leaves of A. melanoxylon. In shortened internodes of stems, oxidative damage, and disordered hormone homeostasis were induced, the cell wall was thickened, hemicellulose and water-soluble pectin contents decreased, while the cellulose content increased under boron deficiency. Furthermore, plenty of genes associated with cell wall metabolism and structural components, including GAUTs, CESAs, IRXs, EXPs, TBLs, and XTHs were downregulated under boron deficiency. Alterations of gene expression in hormone signaling pathways comprising IAA, GA, CTK, ET, ABA, and JA were observed under boron deficiency. TFs, homologous to HD1s, NAC10, NAC73, MYB46s, MYB58, and ERF92s were found to interact with genes related to cell wall metabolism, and the structural components were identified. We established a regulatory mechanism network of boron deficiency-induced shortened internodes in A. melanoxylon based on the above results. This research provides a theoretical basis for understanding the response mechanism of woody plants to boron deficiency.

Characterization of HAK protein family in Casuarina equisetifolia and the positive regulatory role of CeqHAK6 and CeqHAK11 genes in response to salt tolerance.

The potassium transporter group of the HAK/KUP/KT (high-affinity K+)/KUP (K+ uptake)/KT (K+ transporter) family plays a crucial role in plant growth and development as well as in environmental adaptation such as tolerance to salt stress. HAK/KUP/KT genes and their functions have been characterized for a number of plant species, but they remain unknown for Casuarina equisetifolia, an important tree species for coastal protection in southern China and many other countries. In this study, 25 HAK genes were identified in the C. equisetifolia genome. Their gene structure, conserved motif, phylogeny, and expression were comprehensively and systematically analyzed to understand their functions. All HAK genes were relatively conserved and could be divided into four clusters. The expression level of two particular genes, CeqHAK11 and CeqHAK6, increased significantly with the duration of salt treatment. To further elucidated their function in response to salt stress, subcellular localization, and their functional analysis were developed. Results revealed that CeqHAK11 and CeqHAK6 were localized on the plasma membrane, which mainly mediated high-affinity K+ uptake. Overexpression of CeqHAK6 or CeqHAK11 in Arabidopsis showed higher germination and survival rates and longer root length than wild-type (WT) under salt stress, suggesting that both genes improve tolerance to salt stress. Moreover, CeqHAK6 and CeqHAK11 improved their ability to tolerate salt stress by increasing the K+/Na+ ratio and antioxidant enzyme activities (CAT, POD, and SOD), and decreasing reactive oxygen species (ROS) accumulation. Consequently, CeqHAK6 and CeqHAK11 were verified as potassium transport proteins and could be applied for further molecular breeding for salt tolerance in C. equisetifolia or other crops to increasing salt tolerance.

Agrobacterium-mediated genetic transformation of the most widely cultivated superior clone Eucalyptus urophylla × E. grandis DH32-29 in Southern China.

Eucalyptus, as an economically important species for wood and paper industries, remains a challenge to genetic improvement by transgenic technology owing to the deficiency of a highly efficient and stable genetic transformation system, especially in cultivated superior clones. Eucalyptus urophylla × E. grandis clone DH32-29 is most widely planted in southern China, but it is relatively recalcitrant to adventitious bud regeneration, which blocks the establishment of a genetic transformation system. Here, an efficient adventitious bud regeneration and transformation system of Eucalyptus was established using E. urophylla × E. grandis DH32-29 as material. The in vitro leaves from microshoots that were subcultured for 20-25 days were immersed into liquid Woody Plant Medium supplemented with 0.02 mg·L-1 α-naphthaleneacetic acid (NAA) and 0.24 mg·L-1 forchlorfenuron [callus-inducing medium (CIM)]. After 15 days, explants were transferred to a medium containing 0.10 mg·L-1 NAA and 0.50 mg·L-1 6-benzyladenine (shoot-inducing medium, SIM) for adventitious bud induction. The highest regeneration efficiency of adventitious buds was 76.5%. Moreover, an Agrobacterium tumefaciens-mediated genetic transformation system was optimized. The leaves were precultured for 7 days and infected for 30 min with A. tumefaciens strain EHA105 grown to a bacterial density of 0.3 (OD600). After 72 h of cocultivation in the dark, leaves were transferred to CIM supplemented with 100 mg·L-1 cefotaxime (Cef), 100 mg·L-1 timentin, and 15 mg·L-1 kanamycin (Kan) for 15 days to induce calluses. Then, the explants were transferred to SIM supplemented with the same concentration of antibiotics, and the fresh medium was replaced every 15 days until resistant adventitious buds appeared. After inducing roots in root-inducing medium supplemented with 200 mg·L-1 Cef and 75 mg·L-1 Kan, completely transgenic plants were obtained. Using the aforementioned method, the transformation frequency can reach 1.9%. This provides a powerful approach for genetic improvement of E. urophylla × E. grandis DH32-29 and gene function analysis in Eucalyptus.

Transcriptome and structure analysis in root of Casuarina equisetifolia under NaCl treatment.

BACKGROUND: High soil salinity seriously affects plant growth and development. Excessive salt ions mainly cause damage by inducing osmotic stress, ion toxicity, and oxidation stress. Casuarina equisetifolia is a highly salt-tolerant plant, commonly grown as wind belts in coastal areas with sandy soils. However, little is known about its physiology and the molecular mechanism of its response to salt stress. RESULTS: Eight-week-old C. equisetifolia seedlings grown from rooted cuttings were exposed to salt stress for varying durations (0, 1, 6, 24, and 168 h under 200 mM NaCl) and their ion contents, cellular structure, and transcriptomes were analyzed. Potassium concentration decreased slowly between 1 h and 24 h after initiation of salt treatment, while the content of potassium was significantly lower after 168 h of salt treatment. Root epidermal cells were shed and a more compact layer of cells formed as the treatment duration increased. Salt stress led to deformation of cells and damage to mitochondria in the epidermis and endodermis, whereas stele cells suffered less damage. Transcriptome analysis identified 10,378 differentially expressed genes (DEGs), with more genes showing differential expression after 24 h and 168 h of exposure than after shorter durations of exposure to salinity. Signal transduction and ion transport genes such as HKT and CHX were enriched among DEGs in the early stages (1 h or 6 h) of salt stress, while expression of genes involved in programmed cell death was significantly upregulated at 168 h, corresponding to changes in ion contents and cell structure of roots. Oxidative stress and detoxification genes were also expressed differentially and were enriched among DEGs at different stages. CONCLUSIONS: These results not only elucidate the mechanism and the molecular pathway governing salt tolerance, but also serve as a basis for identifying gene function related to salt stress in C. equisetifolia.

Genome-wide analysis of MYB transcription factors and their responses to salt stress in Casuarina equisetifolia.

BACKGROUND: MYB transcription factors are a kind of DNA binding protein that can specifically interact with the promoter region. Members of MYB TFs are widely involved in plant growth and development, secondary metabolism, stress response, and hormone signal transduction. However, there is no report of comprehensive bioinformatics analysis on the MYB family of Casuarina equisetifolia. RESULTS: In this study, bioinformatics methods were used to screen out 182 MYB transcription factors from the Casuarina equisetifolia genome database, including 69 1R-MYB, 107 R2R3-MYB, 4 R1R2R3-MYB, and 2 4R-MYB. The C. equisetifolia R2R3-MYB genes were divided into 29 groups based on the phylogenetic topology and the classification of the MYB superfamily in Arabidopsis thaliana, while the remaining MYB genes (1R-MYB, R1R2R3-MYB, and 4R-MYB) was divided into 19 groups. Moreover, the conserved motif and gene structure analysis shown that the members of the CeqMYBs were divided into the same subgroups with mostly similar gene structures. In addition, many conserved amino acids in the R2 and R3 domains of CeqMYBs by WebLogo analysis, especially tryptophan residues (W), with 3 conserved W in R2 repeat and 2 conserved W in R3 repeat. Combining promoter and GO annotation analysis, speculated on the various biological functions of CeqMYBs, thus 32 MYB genes were selected to further explore its response to salt stress by using qPCR analysis technique. Most CeqMYB genes were differentially regulated following multiple salt treatments. CONCLUSIONS: Seven genes (CeqMYB164, CeqMYB4, CeqMYB53, CeqMYB32, CeqMYB114, CeqMYB71 and CeqMYB177) were assigned to the "response to salt stress" by GO annotation. Among them, the expression level of CeqMYB4 was up-regulated under various salt treatments, indicating CeqMYB4 might participated in the response to salt stress. Our results provide important information for the biological function of C. equisetifolia, as well as offer candidate genes for further study of salt stress mechanism.

Comprehensive Analysis of SnRK Gene Family and their Responses to Salt Stress in Eucalyptus grandis.

The sucrose non-fermentation-related protein kinase (SnRK) is a kind of Ser/Thr protein kinase, which plays a crucial role in plant stress response by phosphorylating the target protein to regulate the interconnection of various signaling pathways. However, little is known about the SnRK family in Eucalyptus grandis. Thirty-four putative SnRK sequences were identified in E. grandis and divided into three subgroups (SnRK1, SnRK2 and SnRK3) based on phylogenetic analysis and the type of domain. Chromosome localization showed that SnRK family members are unevenly distributed in the remaining 10 chromosomes, with the notable exception of chromosome 11. Gene structure analysis reveal that 10 of the 24 SnRK3 genes contained no introns. Moreover, conserved motif analyses showed that SnRK sequences belonged to the same subgroup that contained the same motif type of motif. The Ka/Ks ratio of 17 paralogues suggested that the EgrSnRK gene family underwent a purifying selection. The upstream region of EgrSnRK genes enriched with different type and numbers of cis-elements indicated that EgrSnRK genes are likely to play a role in the response to diverse stresses. Quantitative real-time PCR showed that the majority of the SnRK genes were induced by salt treatment. Genome-wide analyses and expression pattern analyses provided further understanding on the function of the SnRK family in the stress response to different environmental salt concentrations.

Genome-Wide Characterization, Evolution, and Expression Profiling of VQ Gene Family in Response to Phytohormone Treatments and Abiotic Stress in Eucalyptus grandis.

VQ genes play important roles in plant development, growth, and stress responses. However, little information regarding the functions of VQ genes is available for Eucalyptus grandis. In our study, genome-wide characterization and identification of VQ genes were performed in E. grandis. Results showed that 27 VQ genes, which divided into seven sub-families (I-VII), were found, and all but two VQ genes showed no intron by gene structure and conserved motif analysis. To further identify the function of EgrVQ proteins, gene expression analyses were also developed under hormone treatments (brassinosteroids, methyl jasmonate, salicylic acid, and abscisic acid) and abiotic conditions (salt stress, cold 4 °C, and heat 42 °C). The results of a quantitative real-time PCR analysis indicated that the EgrVQs were variously expressed under different hormone treatments and abiotic stressors. Our study provides a comprehensive overview of VQ genes in E. grandis, which will be beneficial in the molecular breeding of E. grandis to promote its resistance to abiotic stressors; the results also provide a basis from which to conduct further investigation into the functions of VQ genes in E. grandis.

Switching from ticagrelor to clopidogrel in patients with ST-segment elevation myocardial infarction undergoing successful percutaneous coronary intervention in real-world China: Occurrences, reasons, and long-term clinical outcomes.

BACKGROUND: Although switching between ticagrelor and clopidogrel is common in clinical practice, the efficacy and safety of this de-escalation remain controversial. HYPOTHESIS: We assessed the occurrences, reasons, and outcomes of switching from ticagrelor to clopidogrel in patients with ST-segment elevation myocardial infarction (STEMI) undergoing successful primary percutaneous coronary intervention (PCI). METHODS: A total of 653 patients with STEMI were randomly assigned to receive loading dose of ticagrelor or clopidogrel before PCI and then received maintenance dose, respectively, for 12 months follow-up. The primary outcome was major adverse cardiac events (MACE), including cardiovascular death, nonfatal myocardial infarction, and stroke. The secondary outcome included unexpected rehospitalization for angina, coronary revascularization, and stent thrombosis. The safety outcome was bleeding described by the Bleeding Academic Research Consortium (BARC) criteria. RESULTS: A total of 602 participants completed the study. The rate of switching from ticagrelor to clopidogrel was 48.6% and the main reason was financial burden. The rate of secondary ischemic events in the de-escalation group was higher than that in the ticagrelor group (15.1% vs 5.6%, P = 0.008), but lower than that in the clopidogrel group (15.1% vs 24.6%, P = 0.03), while there were no significant differences in MACE among the three groups (P = 0.16). De-escalation, ticagrelor, and clopidogrel did not cause significant differences in the rates of major bleeding among the three groups (BARC ≥ 2, P = 0.34). CONCLUSION: Switching from ticagrelor to clopidogrel is very common in patients with STEMI in China. De-escalation might be safe but associated with high risk of ischemic events as compared to ticagrelor.

Genome-wide analysis of Eucalyptus grandis WRKY genes family and their expression profiling in response to hormone and abiotic stress treatment.

The WRKY transcription factors, a large family of proteins in plants, are involved in multiple developmental and biological processes including response to phytohormones and abiotic stress. However, little information is available regarding the WRKY family in Eucalyptus, which has been the most widely planted hardwood trees in tropical and subtropical areas. In this study, a total of 79 WRKY genes (named as EgrWRKY1-79) were identified from the Eucalyptus grandis genome and classified into three main groups according to the phylogenetic analysis, which was further supported by their gene structure and conserved motifs. Of which, 28 EgrWRKYs were involved in tandem duplication but none for segmental duplication, indicating that tandem duplication was the main cause for the expansion of WRKY gene family in E. grandis. Subsequently, expression profiles of EgrWRKY genes in eight different tissues and in response to treatments of three hormones (SA, JA, and BR) and two abiotic stresses (salt and cold) were analyzed. The results revealed that the EgrWRKY genes had differential expression in their transcript abundance and they were differentially expressed in response to plant hormones and salt and cold stresses, suggesting their contributions to plant developmental processes as well as abiotic stresses with the involvement of hormone signaling transduction. Taken together, these findings will increase our understanding of EgrWRKY gene family involved in abiotic stresses and hormone signaling transduction, and also will provide some stress-responsive candidate EgrWRKY genes for further characterization of their functions in Eucalyptus.

Characterization of Brassinazole resistant (BZR) gene family and stress induced expression in Eucalyptus grandis.

Brassinosteroids (BRs) are a group of plant hormones which play a pivotal role in modulating cell elongation, stress responses, vascular differentiation and senescence. In response to BRs, BRASSINAZOLE-RESISTANT (BZR) transcription factors (TFs) accumulate in the nucleus, where they modulate thousands of target genes and coordinate many biological processes, especially in regulating defense against biotic and abiotic stresses. In this study, 6 BZR TFs of Eucalyptus grandis (EgrBZR) from a genome-wide survey were characterized by sequence analysis and expression profiling against several abiotic stresses. The results showed that BZR gene family in Eucalyptus was slightly smaller compared to Populus and Arabidopsis, but all phylogenetic groups were represented. Various systematic in silico analysis of these TFs validated the basic properties of BZRs, whereas comparative studies showed a high degree of similarity with recognized BZRs of other plant species. In the organ-specific expression analyses, 4 EgrBZRs were expressed in vascular tissue indicating their possible functions in wood formation. Meanwhile, almost all EgrBZR genes showed differential transcript abundance levels in response to exogenously applied BR, MeJA, and SA, and salt and cold stresses. Besides, protein interaction analysis showed that all EgrBZR genes were associated with BR signaling directly or indirectly. These TFs were proposed as transcriptional activators or repressors of abiotic stress response and growth and development pathways of E. grandis by participating in BR signaling processes. These findings would be helpful in resolving the regulatory mechanism of EgrBZRs in stress resistance conditions but require further functional study of these potential TFs in Eucalyptus.

Candida tropicalis burn wound sepsis: A series of histopathology-confirmed cases.

Fungal infection in severely burned patients is a serious problem due to various factors, such as the extensive application of antibiotics. In this study, we report on the course of severely burned patients with Candida tropicalis burn wound sepsis. Five such cases were reviewed. The patients were treated with itraconazole intravenously and simultaneous antibiotics to prevent bacterial infections. In addition, dermabrasion was used to excise the eschar and the wound surface was covered immediately with dermatoplasty. Meanwhile, the skin necrosis related to the fungal infection was removed. The wound surfaces of all five patients were healed well and the parameters of laboratory examination went back to normal. We assume that prompt diagnosis and timely treatment including extensive debridement of necrosis, antifungal drugs, and antibiotics were the key points leading to favourable outcome.

Exogenous GA3 application altered morphology, anatomic and transcriptional regulatory networks of hormones in Eucalyptus grandis.

Gibberellins (GAs) play a key role in plant growth and development including cell elongation, cell expansion, and xylem differentiation. Eucalyptus are the world's most widely planted hardwood trees providing fiber and energy. However, the roles of GAs in Eucalyptus remain unclear and their effects on xylem development remain to be determined. In this study, E. grandis plants were treated with 0.10 mg L-1 GA3 and/or paclobutrazol (PAC, a GA inhibitor). The growth of shoot and root were recorded, transverse sections of roots and stems were stained using toluidine blue, and expression levels of genes related to hormone response and secondary cell wall biosynthesis were analyzed by quantitative real-time PCR. The results showed that GA3 dramatically promoted the length of shoot and root, but decreased the diameter of root and stem. Exogenous GA3 application also significantly promoted xylem development in both stem and root. Expression analysis revealed that exogenous GA3 application altered the transcript levels of genes related to the GA biosynthetic pathway and GA signaling, as well as genes related to auxin, cytokinin, and secondary cell wall. These findings suggest that GAs may interact with other hormones (such as auxin and cytokinin) to regulate the expression of secondary cell wall biosynthesis genes and trigger xylogenesis in Eucalyptus plants.

Experience and efficacy of surgery for retaining viable subcutaneous tissue in extensive full-thickness burns.

BACKGROUND AND AIM: For adult patients with extensive full-thickness burns (EFTB), a fascial excision is mostly used but it causes a very significant deformity. This study aims to summarize experience and efficacy of surgery for retaining viable subcutaneous tissue in EFTB. METHOD: Clinical data were reviewed for 31 consecutive adult patients with full-thickness burn (FTB) over 70% total body surface area (TBSA) and undergoing first tangential excision and skin grafting on subcutaneous tissue wound (TESGSTW) within 7 days post burn at our burn center between 2002 and 2013. RESULTS: Average age, total burn area, and FTB area of 31 patients were 32.4 ± 12.8 years, 89.0 ± 6.2% and 80.4 ± 7.6% TBSA, respectively. Of these, 80.6% combined with inhalation injury and 71.0% supervened early shock. Eighteen patients who survived (58.1%) totally underwent 121 times of surgery, of which TESGSTW and autologous skin grafting were 41 and 88 times, respectively. Their average time and area of first tangential excision was 4.1 ± 0.6 days post burn and 33.8 ± 7.6% TBSA, respectively, and accumulated tangential excision area was 58.4 ± 10.8% TBSA. In 39 times of TESGSTW within 14 days post burn, cryopreserved alloskin or fresh young pigskin was applied on 84.6%, and average time and take rate of autologous skin grafting instead of grafted alloskin or xenoskin was 14.6 ± 0.7 days and 89.5 ± 1.4%, respectively. Scalp was the main donor site for autologous skin, especially microskin grafting. Systemic wound healing time roughly was 67.3 ± 1.9 days post burn, meanwhile, viable subcutaneous tissue was retained. Healed wounds were plump, and their extensibility and sensitivity were better by follow-up. CONCLUSION: The surgical treatment in EFTB is practicable and effective.

Development and preparation of a low-immunogenicity porcine dermal scaffold and its biocompatibility assessment.

Acellular dermal matrix (ADM) has been widely used in repair and reconstruction of tissue defect. Therapeutic effect of porcine ADM (PADM) is inferior to that of human ADM (HADM). Relatively high immunogenicity and the resulting strong inflammatory response are major issue in application of PADM. We therefore treated reticular layer PADM (Rl-PADM) with matrix metalloproteinase-7 (MMP-7) and obtained a low-immunogenicity porcine dermal scaffold (LIPDS). Highly immunogenic components, tissue structure, cytocompatibility, and postgrafting histological changes of LIPDS were further investigated. Compared with Rl-PADM, LIPDS showed that the epithelial root sheath, cell debris, laminin, and type IV collagen were almost entirely removed, the structure remained normal, and the interfibrous space was relatively enlarged. Cytocompatibility of LIPDS was similar to that of HADM but superior to Rl-PADM. With regard to the extent of tissue ingrowth in terms of host fibroblasts infiltration and vascularization, LIPDS exhibited clear advantages over Rl-PADM after they had been subcutaneously transplanted in a rat model. In addition, no excessive inflammatory response was observed in LIPDS group up to 28 days postgraft, and the morphosis of collagenous fibers kept essentially normal. However, there were stronger inflammatory response and obvious collagen spallation in Rl-PADM group. The processes of integration and remodeling after the LIPDS grafting were similar to those of a normal wound healing response. The LIPDS graft was vascularized at a relatively high speed. Thus, as an implantable scaffold material, LIPDS is a superior template for guiding tissue regeneration and remodeling.