[Split-thickness scalp and allogenic acellular dermal matrix in repairing deep wounds of hands in patients with extremely extensive burns]

Objective: To explore the clinical effects of split-thickness scalp and allogenic acellular dermal matrix (ADM) in repairing deep wounds of hands in patients with extremely extensive burns. Methods: Six patients with extremely extensive burns complicated by deep burn in hands were admitted to our department from December 2014 to December 2017, including 4 males and 2 females, aged 21 to 58 years. Their total burn areas were from 85% to 95% total body surface area (TBSA), and the sum of deep-partial thickness and full-thickness wounds was larger than 50% TBSA. Under general anesthesia, deep wounds of 10 dorsal hands were repaired by combined transplantation of split-thickness scalp and allogenic ADM in 4 to 6 weeks after injury. The skin grafting range was beyond the metacarpophalangeal joint, including partial dorsal digital deep wounds. Survival of skin grafts on dorsal hands, follow-up of hand shape and functional recovery were observed and recorded. Results: Six patients were successfully treated. There was no infection on the dorsal deep wounds of 10 hands after surgery, and the grafts survived well. During follow-up of 1 to 2 years after operation, there were no recurrent tension blisters or dorsal extension deformity of the metacarpophalangeal joints in 10 hands, the shape and function of hands recovered well, and hand Carroll scores were from 90 to 99 points, with functional levels of Ⅴ and Ⅵ. Conclusions: The combined transplantation of split-thickness scalp and allogenic ADM is a good method for repairing deep hand wounds in patients with extremely extensive burns, which can alleviate the cicatrix hyperplasia and contracture of healed hand wounds, and improve the shape and function of hands.

Diffusion Properties of Normal-Appearing White Matter Microstructure and Severity of Motor Impairment in Acute Ischemic Stroke

BACKGROUND AND PURPOSE

The effect of white matter hyperintensities as measured by FLAIR MR imaging on functional impairment and recovery after ischemic stroke has been investigated thoroughly. However, there has been growing interest in investigating normal-appearing white matter microstructural integrity following ischemic stroke onset with techniques such as DTI.

MATERIALS AND METHODS

Fifty-two patients with acute ischemic stroke and 36 without stroke were evaluated with a DTI and FLAIR imaging protocol and clinically assessed for the severity of motor impairment using the Motricity Index within 72 hours of suspected symptom onset.

RESULTS

There were widespread decreases in fractional anisotropy and increases in mean diffusivity and radial diffusivity for the acute stroke group compared with the nonstroke group. There was a significant positive association between fractional anisotropy and motor function and a significant negative association between mean diffusivity/radial diffusivity and motor function. The normal-appearing white matter ROIs that were most sensitive to the Motricity Index were the anterior/posterior limb of the internal capsule in the infarcted hemisphere and the splenium of the corpus callosum, external capsule, posterior limb/retrolenticular part of the internal capsule, superior longitudinal fasciculus, and cingulum (hippocampus) of the intrahemisphere/contralateral hemisphere.

CONCLUSIONS

The microstructural integrity of normal-appearing white matter is a significant parameter to identify neural differences not only between those individuals with and without acute ischemic stroke but also correlated with the severity of acute motor impairment.

Improvement of Streptococcus suis glutamate dehydrogenase expression in Escherichia coli through genetic modification of acetate synthesis pathway

Escherichia coli generates acetate as an undesirable by-product that has several negative effects on protein expression, and the reduction of acetate accumulation by modifying genes of acetate synthesis pathway can improve the expression of recombinant proteins. In the present study, the effect of phosphotransacetylase (pta) or/and acetate kinase (ackA) deletion on glutamate dehydrogenase (GDH) expression was investigated. The results indicated that the disruptions of pta or/and ackA decreased the acetate accumulation and synthesis of per gram cell, and increased cell density, and GDH expression and synthesis of per gram cell. The pta gene was more important for acetate formation than the ackA gene. Using the strain with deletions of pta-ackA (SSGPA) for GDH expression, acetate accumulation (2·61 g l^-1 ) and acetate synthesis of per gram cell (0·229 g g^-1 ) were lowest, decreasing by 28·29 and 41·43% compared with those of the parental strain (SSG) respectively. The flux of acetate synthesis (6·6%) was decreased by 72·15% compared with that of SSG, and the highest cell density (11·38 g l^-1 ), GDH expression (2·78 mg ml^-1 ), and GDH formation of per gram cell (0·2442 mg mg^-1 ) were obtained, which were 1·22-, 1·43- and 1·17-times higher than the parental strain respectively. SIGNIFICANCE AND IMPACT OF THE STUDY: Significance and Impact of the Study: Acetate is the key undesirable by-product in Escherichia coli cultivation, and both biomass and production of desired products are increased by the reduction of acetate accumulation. In the present study, the strains with deletions of pta or/and ackA were constructed to reduce the acetate accumulation and improve the GDH expression, and the highest expression level of GDH was obtained using the strain with lesion in pta-ackA that was 1·17-times higher than that of the parental strain. The construction strategy of recombinant E. coli for decreasing the acetate excretion can be used for high expression level of other desired products.

Imatinib enhances the anti-tumour effect of doxorubicin in canine B-cell lymphoma cell line

Canine lymphoma is one of the most common malignant tumours occurring in dogs and has a high incidence worldwide. Despite advances in cancer prevention, the treatment of neoplastic diseases still requires improvement. Some cancer cells may resist the effect of chemotherapeutic agents by up-regulating drug transporters leading to increased drug efflux, resulting in intrinsic or acquired drug resistance, which is a mechanism commonly seen in doxorubicin-resistant tumour cells. In this study, canine B-cell lymphoma cell line CLBL1-8.0, a doxorubicin-resistant B cell lymphoma cell line derived from CLBL-1 by increasing the doxorubicin concentration during culturing, exhibited high expression of P-glycoprotein (P-gp, ATP-binding cassette sub-family B member 1 [ABCB1]). These proteins are commonly involved in cancer cell resistance to doxorubicin. Imatinib, a tyrosine kinase inhibitor significantly potentiated the sensitivity of doxorubicin in P-gp-overexpressing doxorubicin-resistant cells. Moreover, a combination of these two drugs may increase the retention of doxorubicin by decreasing the efflux of doxorubicin without affecting P-gp protein overexpression. In conclusion, imatinib reversed doxorubicin resistance by decreasing drug efflux in P-gp-overexpressing doxorubicin-resistant canine lymphoma cells. These results suggest that combining doxorubicin, one of the most widely used chemotherapeutic drugs in the treatment of canine lymphoma, with imatinib might potentially overcome doxorubicin resistance in a clinical setting.

Identification of key pathways and genes changes in pancreatic cancer cells (BXPC-3) after cross-talk with primary pancreatic stellate cells using bioinformatics analysis

Pancreatic ductal adenocarcinoma (PDAC) is one of the most malignant tumors with poor prognosis, and the interaction between activated pancreatic stellate cells (PSCs) and PDAC cells plays an important role in the development of PDAC. The aim of this study was to identify gene changes in BXPC-3 after cross-talk with PSCs and reveal their potential mechanisms. The gene expression profiling analysis of BXPC-3 was completed after co-culture with primary PSCs for 48 h. The gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes pathway (KEGG) enrichment analyses were performed, and the differentially expressed genes (DEGs) were identified by Agilent GeneSpring GX software. In total, 3657 DEGs were identified in BXPC-3, including 1881 up-regulated genes and 1776 downregulated genes. GO analysis results showed that upregulated DEGs were significantly enriched in biological processes (BP), including peptide metabolic process, response to stress and electron transport chain; the downregulated DEGs were significantly enriched in biological processes, including signaling, multicellular organism development and anatomical structure development. KEGG pathway analysis revealed that 19 pathways were upregulated and 32 pathways were downregulated, and that upregulated DEGs were enriched in protein export and glutathione metabolism, while the downregulated DEGs were enriched in axon guidance and focal adhesion. The top 10 upregulated genes and the top 10 downregulated genes were identified. By constructing PPI network, we selected out 10 key genes (TP53, SRC, IL6, JUN, ISG15, CAD, STAT1, OAS3, OAS1, VIM) and significant pathways. The associated survival analysis was performed and the SRC, IL-6, ISG15, STAT1, OAS3, OAS1 and VIM were proved to be related to worse overall survival time of PDAC patients. In conclusion, the present study indicated that the identified DEGs promote our understanding of the molecular mechanisms underlying the interaction between pancreatic cancer cells and PSCs and might be used as molecular targets in the future to study the role of tumor microenvironment in the progression of PDAC.

Record Purcell factors in ultracompact hybrid plasmonic ring resonators

For integrated optical devices and traveling-wave resonators, realistic use of the superior wave-matter interaction offered by plasmonics is impeded by ohmic loss, which increases rapidly with mode volume reduction. In this work, we report composite hybrid plasmonic waveguides (CHPWs) that are not only capable of guiding subwavelength optical mode with long-range propagation but also unrestricted by stringent requirements in structural, material, or modal symmetry. In these asymmetric CHPWs, the versatility afforded by coupling dissimilar plasmonic modes provides improved fabrication tolerance and more degrees of device design optimization. Experimental realization of CHPWs demonstrates propagation loss and mode area of 0.03 dB/μm and 0.002 μm2, corresponding to the smallest combination among long-range plasmonic structures reported to date. CHPW ring resonators with 2.5-μm radius were realized with record Purcell factor compared with existing plasmonic and dielectric resonators of similar radii.

Identification of key pathways and genes changes in pancreatic cancer cells (BXPC-3) after cross-talked with primary pancreatic stellate cells using bioinformatics analysis

Pancreatic ductal adenocarcinoma (PDAC) is one of the most malignant tumors with poor prognosis, and the interaction between activated pancreatic stellate cells (PSCs) and PDAC cells plays an important role in the development of PDAC. The aim of this study was to identify gene changes in BXPC-3 after cross-talked with PSCs and reveal their potential mechanisms. The gene expression profiling analysis of BXPC-3 was completed after co-cultured with primary PSCs for 48 h. The gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes pathway (KEGG) enrichment analyses were performed, and the differentially expressed genes (DEGs) were identified by Agilent GeneSpring GX software. In total, 3657 DEGs were identified in BXPC-3, including 1881 up-regulated genes and 1776 downregulated genes. GO analysis results showed that up-regulated DEGs were significantly enriched in biological processes (BP), including peptide metabolic process, response to stress, and electron transport chain; the down-regulated DEGs were significantly enriched in biological processes, including signaling, multicellular organismal development, and anatomical structure development. KEGG pathway analysis revealed that 19 pathways were upregulated and 32 pathways were downregulated, and that up-regulated DEGs were enriched in protein export and glutathione metabolism, while the down-regulated DEGs were enriched in axon guidance and focal adhesion. The top 10 up-regulated genes, and the top 10 down-regulated genes were identified. By constructing PPI network, we selected out 10 key genes (TP53, SRC, IL6, JUN, ISG15, CAD, STAT1, OAS3, OAS1, VIM) and significant pathways. The associated survival analysis was performed and the SRC, IL-6, ISG15, STAT1, OAS3, OAS1 and VIM were proved to be related to worse overall survival time of PDAC patients. In conclusion, the present study indicated that the identified DEGs promote our understanding of the molecular mechanisms underlying the interaction between pancreatic cancer cells and PSCs and might be used as molecular targets in the future to study the role of tumor microenvironment in the progression of PDAC.

Identification of key pathways and gene changes in primary pancreatic stellate cells after cross-talk with pancreatic cancer cells (BXPC-3) using bioinformatics analysis

It is well known that as the king of cancer, pancreatic ductal adenocarcinoma (PDAC) has relatively malignant biological behavior and poor prognosis. The interaction between pancreatic stellate cells and PDAC cells promotes the development of PDAC. The aim of this study was to describe gene characteristics in pancreatic stellate cell (PSCs) after cross-talked with BXPC-3 and unravel their underlying mechanisms. The expression profiling analysis of genes in PSCs was completed after co-cultured with primary BXPC-3 for 48h. The Kyoto Encyclopedia of Genes and Genomes pathway (KEGG) enrichment analysis and gene ontology (GO) analysis were performed, and the differentially expressed genes (DEGs) were identified by Agilent GeneSpring GX program. In total, 1804 DEGs were filtered out in PSCs, including 958 up-regulated genes and 846 downregulated genes. GO analysis showed that the up-regulated DEGs were significantly enriched in biological processes (BP) such as defense response, immune system process and immune response; the down-regulated DEGs were significantly enriched in biological regulation and cytoskeleton organization. KEGG pathway analysis showed that 28 pathways were upregulated and 5 were downregulated. By constructing PPI network, we selected out 10 key genes (IL6，IL8, IL1B, BCL2, CCL2, CSF2, KIT, ICAM1, PTPRC and IGF1) and significant enriched pathways. In conclusion, the current study suggests that the filtered DEGs contribute to our understanding of the molecular mechanisms underlying the interaction between PSCs and pancreatic cancer cells, and might be used as molecular targets to further the study the role of tumor microenvironment in the progression of PDAC.