A cascaded convolutional neural networks for stroke detection imaging.

In recent years, electrical impedance tomography has widely been used in stroke detection. To improve the prediction accuracy and anti-noise ability of the system, the inverse problem of electrical impedance tomography needs to be solved, for which cascade convolutional neural networks are used. The proposed network is divided into two parts so that the advantages can be compounded when parts of a network are cascaded together. To get high-resolution imaging, an optimized network based on encoding and decoding is designed in the first part. The second part is composed of a residual module, which is used to extract the characteristics of voltage information and ensure that no information is lost. The anti-noise performance of the network is better than other networks. In physical experiments, it is also proved that the algorithm can roughly restore the location of the object in the field.

Dog bite-induced necrosis of lymph nodes: A case report and literature review.

Dog bite is a common skin injury, which mainly causes structural damage, infection, and psychological trauma. Among these complications, infection by oral flora from animals has a major effect on later treatment. Each animal has a relatively unique oral microbial flora, which has a potential risk of infection and affects the formulation of treatment plans. Although lymph node necrosis is a common disease in the medical field, distant metastatic abscess and lymph node necrosis caused by dog bite are still worthy of early clinical suspicion after a patient presents with a dog bite disease. A high index of suspicion is greatly significant in shortening the patient's hospital stay, promoting wound healing, and reducing psychological trauma of patients.

Effect of Waiting Time for Radioactive Iodine Therapy on Outcome in N1 Stage Papillary Thyroid Cancer.

CONTEXT: The waiting time for radioactive iodine therapy (WRAIT) after total thyroidectomy (TT) in patients with papillary thyroid cancer (PTC) and lymph node metastases (N1) has not been sufficiently investigated for risk of adverse outcomes. OBJECTIVE: This work aimed to estimate the effect of WRAIT on the outcomes of disease persistence and recurrence among patients with N1 PTC and investigate factors predictive of delayed radioactive iodine therapy (RAIT). METHODS: This retrospective cohort study was conducted in a university hospital. A total of 909 patients with N1 PTC were referred for RAIT between 2014 and 2018. WRAIT is the duration between TT and initial RAIT. The optimal WRAIT threshold determined using recursive partitioning analysis was used to define early and delayed RAIT. The primary end point was tumor persistence/recurrence. We compared the outcomes of patients with early and delayed RAIT using inverse probability weighting based on the propensity score. RESULTS: The WRAIT threshold that optimally differentiated worse long-term remission/excellent response outcomes was greater than 88 days (51% of our cohort; n = 464). WRAIT exceeding 88 days was associated with an augmented risk of disease persistence/recurrence (odds ratio, 2.47; 95% CI, 1.60-3.82) after adjustment. Predictors of delayed RAIT included residence in lower-income areas, reoperation before the initial RAIT, TT at a nonuniversity-affiliated hospital, multifocality, extrathyroidal extension, N1b disease, and pre-RAIT-stimulated thyroglobulin level less than 1 ng/mL. CONCLUSION: Delayed RAIT beyond 88 days after TT in patients with N1 PTC independently increased the risk of disease persistence/recurrence. Evaluation of the predictive determinants of prolonged WRAIT may help target at-risk patients and facilitate interventions.

The number of metastatic lymph nodes optimizes staging in patients aged 55 years or older with papillary thyroid cancer.

Purpose: Current staging criteria for papillary thyroid cancer (PTC) do not include the number of metastatic lymph nodes (LNs), which is highly predictive of survival in multiple cancers. The LN metastasis burden is particularly relevant for older adults with thyroid cancer because of their poor prognosis. We examined a modified staging system for this population utilizing node number (Nn). Methods: Overall, 14,341 patients aged 55 years or older with stage I-IVB PTC were identified in the 2004-2015 Surveillance, Epidemiology and End Results database. Cox regression models were conducted to test the relationship between positive LN number and PTC-specific survival (PTCSS). Independent training/validation sets were used to derive and validate a new revised TNnM grouping. The 8th edition American Joint Committee on Cancer TNM staging system was compared with TNnM stage by calculating the 10-year PTCSS rates, Harrell's concordance index (C-index), and Akaike's information criterion (AIC). Results: An increase in number of LN metastases was identified as an independent, negative prognostic factor for PTCSS in multivariate analysis. 10-year PTCSS for stage I-IVB based on the AJCC 8th edition TNM were 98.83%, 93.49%, 71.21%, 72.95%, and 58.52%, respectively, while 10-year PTCSS for the corresponding stage in the TNnM were 98.59%, 92.2%, 83.26%, 75.24%, and 56.73%, respectively. The revised TNnM stage was superior, with a higher C-index and a lower AIC in both the training and validation cohorts. Conclusion: The TNnM staging system for PTC patients ≥ 55 years could be associated with improved outcomes. External validation studies of this system are warranted.

Genome-Wide Analysis of Differentially Expressed mRNAs and lncRNAs in Koi Carp Infected with Koi Herpesvirus.

Long noncoding RNAs (lncRNAs) constitute an emerging group of ncRNAs that modulate gene expression at the transcriptional or translational level. Koi herpesvirus (KHV), also known as Cyprinus herpesvirus type 3 (CyHV-3) and characterized by high pathogenicity and high mortality, has caused substantial economic losses in the common carp and koi carp fisheries industry. In this work, we sequenced the lncRNA and mRNA of host koi carp infected with KHV. A total of 20,178 DEmRNAs were obtained, of which 5021 mRNAs were upregulated and 15,157 mRNAs were downregulated. Both KEGG pathways and GO terms were enriched in many important immune pathways. The KEGG analysis showed that DEGs were significantly enriched in many important immune pathways, such as apoptosis, NOD-like receptor signaling pathway, Jak-STAT signaling pathway, TNF signaling pathway, IL-17 signaling pathway, NF-kappa B signaling pathway, and so on. Furthermore, a total of 32,697 novel lncRNA transcripts were obtained from koi carp immune tissues; 9459 of these genes were differentially expressed. Through antisense, cis-acting, and trans-acting analyses, the target genes of differentially expressed lncRNAs (DElncRNAs) were predicted. Gene ontology (GO) annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses showed that the DElncRNA expression pattern was consistent with the differential mRNA expression pattern. The lncRNA-mRNA network analysis, which included many immune pathways, showed that after KHV infection, the expression of most lncRNAs and their target mRNAs were downregulated, suggesting that these lncRNAs engage in a positive regulatory relationship with their target mRNAs. Considering that many studies have shown that herpesviruses can escape the immune system by negatively regulating these immune pathways, we speculated that these lncRNAs play a significant role in KHV's escape from host immunity. Furthermore, 10 immune-related genes and 20 lncRNAs were subsequently verified through RT-qPCR, to confirm the accuracy of the high-throughput sequencing results. In this study, we aimed to explore lncRNA functions in the immune response of lower vertebrates and provide a theoretical basis for the study of noncoding RNAs in teleosts. Therefore, exploring lncRNA expression in KHV-infected koi carp helped us better understand the biological role played by lncRNA-dependent pathways in aquaculture animal viral infection.

Charge Photogeneration and Recombination in Fluorine-Substituted Polymer Solar Cells.

In this contribution, we studied the effect of fluorine substitution on photogenerated charge generation, transport, and recombination in polymer solar cells. Two conjugated polymer materials, PBDTTT-E (fluorine free) and PTB7 (one fluorine substitution), were compared thoroughly. Meanwhile, various characterization techniques, including atomic force microscopy, steady-state spectroscopy, transient absorption spectroscopy, spectroelectrochemistry, and electrical measurements, were employed to analyse the correlation between molecular structure and device performance. The results showed that the influence of fluorine substitution on both the exciton binding energy of the polymer and the carrier recombination dynamics in the ultrafast timescale on the polymer was weak. However, we found that the fluorine substitution could enhance the exciton lifetime in neat polymer film, and it also could increase the mobility of photogenerated charge. Moreover, it was found that the SOMO energy level distribution of the donor in a PTB7:PC71BM solar cell could facilitate hole transport from the donor/acceptor interface to the inner of the donor phase, showing a better advantage than the PBDTTT-E:PC71BM solar cell. Therefore, fluorine substitution played a critical role for high-efficiency polymer solar cells.

[Application of free anterolateral thigh flap with fascia lata for diabetic foot ulcers with bone exposure].

OBJECTIVE: To investigate the effectiveness of free anterolateral thigh flap (ALTF) with fascia lata in repairing diabetic foot ulcers (DFUs) with bone exposure. METHODS: Between January 2019 and January 2021, 20 patients with DFUs with bone exposure were admitted. There were 17 males and 3 females with a median age of 57.5 years (range, 48-76 years). There were 10 cases of Wagner grade 3 and 10 cases of grade 4. The DFUs formed 1 to 14 months, with a median time of 3 months. The patients underwent CT angiography, which showed extensive atherosclerosis in both lower limbs; 6 of them were severely narrowed or occluded and underwent percutaneous transluminal angioplasty. The size of wound ranged from 7 cm×6 cm to 27 cm×10 cm after applied first-stage debridement combined with vacuum sealing drainage treatment. In the second-stage, free ALTF with fascia lata was used to repair wounds and partial defects of tendons. The size of flap ranged from 8 cm×5 cm to 28 cm×11 cm. The wound of the donor site was sutured directly. The survival of the flap, the healing time of the wound, and the complications were recorded. The laser speckle blood flow imaging system was used to detect the blood perfusion of the flap and the skin around the flap at 2 weeks and 6 months after operation. The foot function was evaluated by American Orthopaedic Foot and Ankle Society (AOFAS) score at 6 months after operation. RESULTS: After operation, effusion under the flap happened in 6 cases, which cured after symptomatic treatment. Flaps survived completely in 14 cases. The tissue necrosis at the edges of the flaps occurred in 3 cases and healed after dressing changes. Venous crisis of flaps occurred in 3 cases, of which 1 case was completely necrotic after exploration, and the other 2 cases were partially alive. The wounds of 3 cases were repaired with skin grafts after debridement and dressing. The flap survival rate was 95.0%, and the limb salvage rate was 100%. The wound healing time after flap transplantation was 14-30 days, with an average of 19.1 days. Two patients had recurrence of peripheral skin ulcers of the flaps within 1 month after healing, which healed after conservative dressing changes. Eighteen cases of incisions at donor site healed by first intention, 2 cases had local skin necrosis and healed by debridement and suture. All patients were followed up 6-30 months, with a median time of 11 months. The texture, appearance, and elasticity of the flaps were good. All patients could walk alone without pain. At 6 months after operation, the AOFAS score was 75.9±11.9, which was significantly different from that (44.7±18.4) before operation ( t=-7.025, P=0.000). The blood perfusion value increased from (38.1±7.8) PU at 2 weeks to (42.7±10.3) PU, and the difference was significant ( t=-4.680, P=0.001). CONCLUSION: Free ALTF with fascia lata has a rich blood supply and a high survival rate. It can be used to repair DFUs with bone exposure. After the free skin flap healed, it can promote revascularization of the affected foot, reduce the probability of ulcer recurrence, and avoid amputation.

Synergistic Engineering of Substituents and Backbones on Donor Polymers: Toward Terpolymer Design of High-Performance Polymer Solar Cells.

Design of terpolymers via copolymerization has emerged as a potential strategy for expanding the family of high-performing donor polymers and boosting the photovoltaic performance of non-fullerene polymer solar cells (PSCs). Herein, double-ester-substituted thiophenes and thienothiophenes are incorporated as third building blocks into the donor polymer PBDB-TF, developing two groups of terpolymers with donor-acceptor 1-donor-acceptor 2 (D-A1-D-A2)-type backbones. An optimum 10% concentration of double-ester-substituted thiophene units in PBDB-TF-T10 downshifts the molecular energy and increases the dielectric constant, and delivers proper miscibility and nanostructure in blends with the high-performing acceptor Y6. These characteristics are designed to synergistically enhance the photovoltage, photocurrent, and efficiency of PSCs. The resulting power conversion efficiency (PCE) of 16.4% surpasses the conventional PBDB-TF/Y6 PSCs, and it is among the best-performing PSCs based on PBDB-TF-derived terpolymers. Gratifyingly, PBDB-TF-T10 does not show significant batch-to-batch variation and it retains high PCEs above 16% in a broad range of molecular weights. This work introduces a facile strategy to easily synthesize terpolymers in combination with Y6 for the attainment of high-performing and reproducible non-fullerene PSCs.

Ground- and excited-state characteristics in photovoltaic polymer N2200.

As a classical polymer acceptor material, N2200 has received extensive attention and research in the field of polymer solar cells (PSCs). However, the intrinsic properties of ground- and excited-states in N2200, which are critical for the application of N2200 in PSCs, remain poorly understood. In this work, the ground- and excited-state properties of N2200 solution and film were studied by steady-state and time-resolved spectroscopies as well as time-dependent density functional theory (TD-DFT) calculations. The transition mechanism of absorption peaks of N2200 was evaluated through the natural transition orbitals (NTOs) and hole-electron population analysis by TD-DFT. Time-resolved photoluminescence (TRPL) study shows that the lifetimes of singlet excitons in N2200 chlorobenzene solution and film are ∼90 ps and ∼60 ps, respectively. Considering the absolute quantum yield of N2200 film, we deduce that the intrinsic lifetime of singlet exciton can be as long as ∼20 ns. By comparing the TRPL and transient absorption (TA) kinetics, we find that the decay of singlet excitons in N2200 solution is dominated by a fast non-radiative decay process, and the component induced by intersystem crossing is less than 5%. Besides that, the annihilation radius, annihilation rate and diffusion length of singlet excitons in N2200 film were evaluated as 3.6 nm, 2.5 × 10-9 cm3 s-1 and 4.5 nm, respectively. Our work provides comprehensive information on the excited states of N2200, which is helpful for the application of N2200 in all-PSCs.

Photogenerated Intrinsic Free Carriers in Small-molecule Organic Semiconductors Visualized by Ultrafast Spectroscopy.

Confirmation of direct photogeneration of intrinsic delocalized free carriers in small-molecule organic semiconductors has been a long-sought but unsolved issue, which is of fundamental significance to its application in photo-electric devices. Although the excitonic description of photoexcitation in these materials has been widely accepted, this concept is challenged by recently reported phenomena. Here we report observation of direct delocalized free carrier generation upon interband photoexcitation in highly crystalline zinc phthalocyanine films prepared by the weak epitaxy growth method using ultrafast spectroscopy. Transient absorption spectra spanning the visible to mid-infrared region revealed the existence of short-lived free electrons and holes with a diffusion length estimated to cross at least 11 molecules along the π-π stacking direction that subsequently localize to form charge transfer excitons. The interband transition was evidenced by ultraviolet-visible absorption, photoluminescence and electroluminescence spectroscopy. Our results suggest that delocalized free carriers photogeneration can also be achieved in organic semiconductors when the molecules are packed properly.

Thermal-triggerd proteinquake leads to disassembly of DegP hexamer as an imperative activation step.

The Escherichia coli DegP has been reported to function both as molecular chaperone and protease for the quality control of outer membrane protein biogenesis. Activation of the inactive DegP hexamers was believed to occur via their disassembly into trimeric units and subsequent reassembly into larger oligomers (12-mers and 24-mers). Here, we analyzed the thermal stability and the unfolding dynamics of the different secondary structure components of the DegP hexamers using Fourier transform infrared spectroscopy and temperature-jump nanosecond time-resolved IR difference absorbance spectroscopy. We found that the interfacial secondary structure components possess a degreed thermal stability, with the disassembly of the DegP hexamers follows a "proteinquake" manner, such that the fully exposed parts of the interfacial ß-sheets serving as the temperature sensor and epicenter to drive the sequential unfolding/disassembly process that finishes within about 134 ns at room temperature.

Effect of gene transfecting at different times on mandibular distraction osteogenesis.

BACKGROUND: Recently, numerous research of gene therapy for mandibular distraction has been published. Based on previous study, the authors used New Zealand rabbits bilateral mandibular distraction model and used electroporation mediate gene therapy at different time, to explore the optimal time for gene therapy and obtain a better effect. METHODS: Forty-eight New-Zealand rabbits were used; after accomplished osteotomy and implant distraction devices on mandible bilaterly, the rabbits were randomly divided into 4 groups: groups A, B, and C were transfected recombinant plasmids pIRES-hBMP2-hVEGF165 via electroporation-mediated approach at latency period, distraction period, and consolidation period, respectively. Group D is a control group, only distracted without gene transfection. After 3 days of latency period, the device was activated at the rate of 1 mm per day for 10 days. Three rabbits of each group were sacrificed at 1, 2, 4, and 8 weeks of consolidation, respectively. The mandibles were harvested; the left was subject to radiograph examination for bone healing, and quantitative computed tomography detect for the bone mineral density (BMD) of newly formed bone in the distraction gap. The biomechanical properties of the new generation bone at the fourth and eighth weeks of consolidation of each group were detected using 3-point bending test. RESULTS: The BMD and the stiffness of newly formed bone increased with the pass of the consolidation time in each group. After 1 week of consolidation, there is no significant difference of BMD among groups A, B, and C. However, the BMD of groups A, B, and C is higher than that of group D. After 2, 4, and 8 weeks of consolidation, the BMD of group B is significantly higher than those of groups A, C, and D. The biomechanical parameters are also higher in group B than those of groups A, C, and D after 4 and 8 weeks of consolidation. CONCLUSIONS: It is better to transfect gene at distraction period than at other stages of DO; in this way, we can obtain more remarkable effect on new bone formation. It suggests that the distraction stage is the optimal time for gene therapy.

Effect of electroporation-mediated transfecting recombinant plasmid pIRES-hBMP2-hVEGF165 on mandibular distraction osteogenesis.

Distraction osteogenesis requires a long consolidation period and has a low but real failure rate. Bone morphogenetic proteins (BMPs) accelerate bone deposition in fractures and critical-sized bone defects. Vascular endothelial growth factor (VEGF) is a promising reagent for inducing angiogenesis, and is an essential coordinator of extracellular matrix remodeling, angiogenesis, and bone formation in the growth plate. However, their effects on mandibular distraction osteogenesis are unknown. We investigated the effect of local delivery of plasmid pIRES-hBMP-2-hVEGF165 into a distraction area by electroporation-mediated approach.A New Zealand rabbit model were used. Activation of the device was commenced after 3 days of latency period and proceeded at the rate of 0.8 mm per day for 7 days. After the completion of activation, the rabbits were randomly divided into 5 groups: group A: recombinant plasmid 2 µg (0.1 µg/µL) pIRES-hVEGF165-hBMP2 was injected into the distraction area after the completion of activation; group B: recombinant plasmid pIRES-hBMP2 was injected into the distraction area; group C: recombinant plasmid pIRES-hVEGF165 was injected into the distraction area; group D: pIRES was injected into the distraction area, and group E: normal saline was injected into the distraction area. After injection every group used electroporation. Subsequently, the rabbits were examined by quantitative computed tomography, mechanical testing, and histomorphometric analysis.BMD of newly formed bone of the distraction area in groups A, B, and C were remarkably higher than those of groups D and E at different times (P < 0.001). At 4 and 8 weeks of consolidation, the crushing strength of 3 points of the newly formed bone in group A was remarkably higher than those of groups B, C, D, and E (P < 0.01). The results demonstrated statistically remarkable increase in regenerated bone in the gene-transfected groups.Electroporation-mediated transfecting recombinant plasmid pIRES-hVEGF165-hBMP2 could produce a satisfactory proceeding of osteogenesis and calcification, which surpassed that of the control group. This finding indicates that a combination of VEGF and BMP may make osteogenesis and angiogenesis appear at the same time. Furthermore, it may magnify the effect of single growth factor, and promote growth and reparative process of bone.

The effect of continuous elastic outside distraction on the expressions of vascular endothelial cell growth factor and microvessel density in female porcine nipple.

BACKGROUND: We have proposed a method to correct the inverted nipple with good clinical results. The aim of the study presented here is to show the effect of continuous elastic distraction on the expression of vascular endothelial growth factor and microvessel density in the female porcine nipple. This article also explores the probable mechanism correction of inverted nipples. METHODS: Four female 3-month-old pigs each with 12 nipples were used. Four nipples of each minipig were used as control with the other eight nipples continuously distracted with prefabricated instruments. The nipples were excised at weeks 2, 4, 8, and 12 after distraction. Immunohistochemical staining was performed to observe the expression of vascular endothelial cell growth factor (VEGF) and CD34 in those tissues. The integral optical density of VEGF-positive cells and microvessel density (MVD) were also counted. RESULTS: The volumes of the nipples all increased after traction compared with those of the control group. The diameters and heights of the nipples showed significant changes (P<0.01). In immunohistochemical staining, the expressions of VEGF and CD34 of all distracted groups were positive. The staining intensity of traction groups was moderate and that of the control groups was weakly positive. The integral optical density of VEGF-positive cells and MVD compared with the control group were significantly different (P<0.01), and there was a significant positive correlation in MVD and VEGF. CONCLUSION: Continuous elastic distraction can promote the expression of some growth factors in nipples.

[Effect of gene transfection at different time on bone mineral density and strength of newly formed bone in mandibular distraction gap in rabbit].

OBJECTIVE: To investigate the effect of gene transfection at different time on bone mineral density and strength of newly formed bone in mandibular distraction gap in rabbit, so as to explore the optimal time for gene therapy and enhance the therapeutic effect. METHODS: 48 New-Zealand rabbits were employed to receive mandibular osteotomy and implantation of distraction devices bilaterly. Then the rabbits were randomly divided into 4 groups as group A, B and C and D. The animals in group A, B, and C were transfected with recombinant plasmids pIRES-hBMP2-hVEGF165 via electroporation-mediated approach at latency period, distraction period, consolidation period respectively. Group D was used as control group without gene transfection. After 3 days of latency period, the distraction devices were activated at the rate of 0.8 mm per day for 10 days. Three rabbits in each group were sacrificed at 1 wk, 2 wk, 4 wk and 8 wk of consolidation respectively. The mandibles were harvested and the left mandible received X-ray examination for bone healing, and quantitative computed tomography (QCT) dectection for the bone mineral density (BMD) of newly formed bone in the distraction gap. The biomechanical properties of the new generation bone at 4 th and 8 th week of consolidation in each group were detected by three point bending test. RESULTS: The bone mineral density and the biomechanical strength of newly formed bone increased along the length of consolidation in each group. After 1 week of consolidation, there was no significant difference in BMD among group A (83.43 +/- 9.96), group B (92.29 +/- 11.25), group C (89.93 +/- 14.15), P > 0.05. But the BMD of group A, B and C was higher than that of group D (70. 31 +/- 3.30), P < 0.05. After 2wk, 4 wk and 8 wk of consolidation, the BMD of group B (137.54 +/- 7.20,492.93 +/- 17.57, 790.48 +/- 12.19) was significantly higher than those of group A (121.44 +/- 9.27, 396.15 +/- 15.70, 603.39 +/- 16.46), C (125.06 +/- 7.24, 464.15 +/- 15.45, 764.15 +/- 17.28), and D (98.86 +/- 8.13, 336.45 +/- 11.95, 577.89 +/- 18.43), P < 0.05. The biomechanical parameters were also higher in group B than those of group A, C and D after four and eight weeks of consolidation (P < 0.05). CONCLUSION: It is better to transfect gene at the beginning of distraction (distraction period) than at other stages of DO. In this way, more remarkable effect could be obtained on new bone formation. It suggests that the distraction stage is the optimal time for gene therapy.

Surface display of monkey metallothionein α tandem repeats and EGFP fusion protein on Pseudomonas putida X4 for biosorption and detection of cadmium.

Monkey metallothionein α domain tandem repeats (4mMTα), which exhibit high cadmium affinity, have been displayed for the first time on the surface of a bacterium using ice nucleation protein N-domain (inaXN) protein from the Xanthomonas campestris pv (ACCC-10049) as an anchoring motif. The shuttle vector pIME, which codes for INAXN-4mMTα-EGFP fusion, was constructed and used to target 4mMTα and EGFP on the surface of Pseudomonas putida X4 (CCTCC-209319). The surface location of the INAXN-4mMTα-EGFP fusion was further verified by western blot analysis and immunofluorescence microscopy. The growth of X4 showed resistance to cadmium presence. The presence of surface-exposed 4mMTα on the engineered strains was four times higher than that of the wild-type X4. The Cd²âº accumulation by X4/pIME was not only four times greater than that of the original host bacterial cells but was also remarkably unaffected by the presence of Cu²âº and Zn²âº. Moreover, the surface-engineered strains could effectively bind Cd²âº under a wide range of pH levels, from 4 to 7. P. putida X4/pIME with surface-expressed 4mMTα-EGFP had twice the cadmium binding capacity as well as 1.4 times the fluorescence as the cytoplasmic 4mMTa-EGFP. These results suggest that P. putida X4 expressing 4mMTα-EGFP with the INAXN anchor motif on the surface would be a useful tool for the remediation and biodetection of environmental cadmium contaminants.

[Effect of electroporation-mediated gene transfect on the expression of cyclins during mandible distraction in rabbit].

OBJECTIVE: To investigate the effect of electroporation-mediated gene transfect on the expression of cyclins during mandible distraction in rabbit. METHODS: Bilateral mandibular osteotomy was performed in 45 New-Zeland rabbits. After a latency of 3 days, the mandibles were elongated using distractors with a rate of 0.8 mm/day for 7 days. After the completion of distraction, the rabbits were randomly divided into 5 groups. 2 microg (0.1 microg/microl) of pIRES-hVEGF165-hBMP2, recombinant plasmid pIRES-hBMP2, recombinant plasmid pIRES-hVEGF165, pIRES and the same volume of normal saline (NS) was injected into the distraction area in each group, respectively. After injection, electroporation was performed in every group. Three animals in each group were sacrificed at 7, 14, and 28 days after completion of distraction, respectively. The lengthened mandibles were harvested and processed for immunohistochemical examinations. The expression of cyclins A, D1 ,E in positive cells were measured by CMIAS-2001A computerized image analyzer. The data were analyzed with the single factor analysis of variance and q test. RESULTS: Cyclins A, D1, E staining was mainly located in inflammatory cells, granulation tissue monocyte, fibroblast, osteoblasts, osteocyte and the connective tissues around the new bone. The expression reached to the peak at 7th day of consolidation, and decreased at 14th day, and weak at 28th day. Image analysis results showed that, at 7th day, the expression absorbance A in group C (0.59 +/- 0.14) was the strongest, compared to group A (0.41 +/- 0.13), B (0.38 +/- 0.14), D (0.34 +/- 0.12) and E (0.31 +/- 0.10), showing a significant difference (P < 0.05, P < 0.01). There was no significance difference between group A and B (P > 0.05), but the difference between group A/B and group D/E (P < 0.05). At 14th and 28th day, there was no significant difference among group A (0.39 +/- 0.11), B (0.34 +/- 0.10) and C (0.33 +/- 0.09) (P > 0.05), but there was significant difference between group A/B/C and group D (0.19 +/- 0.12) or E (0.14 +/- 0.04) (P < 0.05 or P < 0.01). CONCLUSIONS: Electroporation-mediated gene transfection can promote cyclins A, D1, E expression effectively, which may promote cell differentiation and proliferation, stimulate extracellular matrix synthesis and new bone formation in distraction gap.

[Influence of serum from rats with scald on the cytoskeleton of colonic smooth muscle cells of rats].

OBJECTIVE: To study the influence of serum from scalded rats on the cytoskeleton of colonic smooth muscle cells (CSMC) of rats cultured in vitro, and to probe the possible mechanism of gastrointestinal motility disorder after burn. METHODS: CSMC isolated from healthy adult Wistar rat were cultured and divided into scald serum group (SS) and normal serum group (NS) according to the random number talbi. Two normal Wistar rats were used, one of which was inflicted with deep partial-thickness scald. Serum was obtained from blood collected from these two rats respectively and diluted to 20% in concentration. Serum from scald and normal rats were respectively added to the culture of CSMC in SS and NS groups. The expression of actin and the relative content of ß-tubulin in CSMC was respectively determined with flow cytometry and Western blot at post treatment hour (PTH) 1, 3, 6, and 12 (with 10 samples in each group at each time point). Data were processed with t test. RESULTS: Fluorescence intensity of actin in SS group at PTH 1, 3, 6, and 12 was respectively 59 ± 4, 26 ± 6, 39 ± 6, and 42 ± 6, all significantly lower than those in NS group (95 ± 10, 91 ± 10, 102 ± 9, and 97 ± 9, with t value respectively 10.528, 18.069, 18.748, 16.647, P < 0.05 or P < 0.01). In SS group, the fluorescence intensity decreased to the nadir at PTH 3, and then increased persistently at PTH 6 and 12. (2) Relative content of ß-tubulin in SS group at PTH 1, 3, 6, and 12 was respectively 14.44 ± 0.26, 8.61 ± 0.19, 11.76 ± 0.31, and 12.13 ± 0.29, all significantly less than those in NS group (22.37 ± 1.15, 21.87 ± 1.79, 23.24 ± 1.55, and 21.99 ± 2.02, with t value respectively 21.176, 23.365, 23.000, 15.273, P values all below 0.01). In SS group, the relative content of ß-tubulin decreased to the nadir at PTH 3 and increased slowly at PTH 6 and 12. CONCLUSIONS: The reduction of CMSC content which has the tendency of increasing later, can be attributed to the influence of scald serum in initial stage. This may be related to the tolerance and adaptation to scald serum and self-repair of CMSC.

[The effect of electroporation mediated gene therapy on bone mineral density and strength of new-formed bone in mandibular distraction gap in rabbit].

OBJECTIVE: To explore the effect of electroporation mediated gene therapy on bone mineral density and strength of new-formed bone in mandibular distraction gap, so as to enhance the osteogenesis and shorten the distraction term. METHODS: New-Zealand rabbits were employed. The distraction began after 3 days of latency period at the rate of 0. 8 mm per day for 7 days. After distraction, the rabbits were randomly divided into 5 groups to receive injection in the distraction gap with recombinant plasmid 2 microg (0.1 microg/microl) pIRES-hVEGF165-hBMP2 in group A, with recombinant plasmid pIRES-hBMP2 in group B, with recombinant plasmid pIRES-hVEGF165 in group C, with pIRES in group D, and with normal saline (NS) in group E. After injection, electroporation was performed in all the groups. After 1 week, 2 weeks, 4 weeks and 8 weeks of consolidation, all the animals underwent X-ray and quantitative computed tomography (QCT). The new-formed bone in distraction gap was selected as regions of interest (ROI) to measure the bone mineral density(BMD). Then the rabbits were sacrificed and the new-formed bone samples were harvested to detect 3-point crushing strength. RESULTS: BMD of newly formed bone in group A, B and C was markedly higher than that in group D and E (P < 0.01). After 2 weeks of consolidation, BMD in group A was much higher than that in the other groups, but there was no difference between group B and C. After 4 weeks of consolidation, BMD in group A and B was markedly higher than that in group C, D and E (P < 0.01). After 8 weeks of consolidation, BMD in group A was markedly higher than that in the other groups. While the BMD was not significantly different between group B and C, but the BMD in group B and C was higher than that in group D and E (P < 0.01). After 4 weeks of consolidation, the 3-point crushing strength of newly formed bone in group A was markedly higher than that in group B,C, D and E (P < 0.01), which was still the same after 8 weeks of consolidation. And the crushing strength in group B was higher than that in group C, D and E (P < 0. 05). CONCLUSIONS: Electroporation-mediated transfection of recombinant plasmid pIRES-hVEGF165-hBMP2 could greatly enhance osteogenesis and calcification. A combination of VEGF and BMP may promote osteogenesis and angiogenesis simultaneously, so as to magnify the effect of each growth factor, resulting a synergetic effect.

[Clinical study on repair of burn wounds of degree II with recombinant human epidermal growth factor in elderly patients].

OBJECTIVE: To explore the therapeutic effect of recombinant human epidermal growth factor (rhEGF) for burn wounds of degree II in the elderly patients. METHODS: From February 2003 to October 2008, 80 patients with burn wounds of degree II were treated and randomly divided into two groups (n=40). In treatment group, there were 24 males and 16 females with an average age of 70 years (60-86 years), including 20 cases of superficial II degree and 20 cases of deep II degree. Burn wounds were caused by flame in 23 cases, by hot liquid in 16 cases, and by electricity in 1 case. The mean time from injury to hospitalization was (2.87 +/- 2.57) hours. The wounds were treated with silver sulfadiazine (SD-Ag) and rhEGF. In control group, there were 18 males and 22 females with an average age of 69 years (61-83 years), including 19 cases of superficial II degree and 21 cases of deep II degree. Burn wounds were caused by flame in 23 cases, by hot liquid in 14 cases, by electricity in 2 cases, and by chemistry in 1 case. The mean time from injury to hospitalization was (3.39 +/- 3.33) hours. The wounds were treated with SD-Ag. The dressing was changed every day until wounds healing. There were no significant differences in general data between two groups (P > 0.05). RESULTS: Wound did not heal in 1 case (deep II degree) of treatment group and in 5 cases (deep II degree) of control group over 40 days and free skin graft was used to repair wound. One case (superficial II degree) in control group gave up treatment. One case (deep II degree) died of pulmonary infection in treatment group. These cases were excluded and 72 cases were analysed. No other side reactions were observed in treatment group except for flash stabbing pain (4 cases) and pruritus (2 cases). Wound infection occurred in 5 cases of the control group and in 3 cases of the treatment group, and wound healed after symptomatic treatment. The healing time of burn wound was (14.30 +/- 1.26) days (superficial II degree) and (26.11 +/- 2.97) days (deep II degree) in the treatment group, was (16.22 +/- 1.40) days (superficial II degree) and (29.13 +/- 4.99) days (deep II degree) in control group, showing significant difference between two groups (P < 0.05). CONCLUSION: In combined treatment, rhEGF can promote the healing of burn wounds of degree II in the elderly patients.