Influence of high-voltage electric burn on the microcirculation of heart in rabbit / 中华烧伤杂志

<p><b>OBJECTIVE</b>To study the influence of high-voltage electric burn on the microcirculation of heart in rabbit.</p><p><b>METHODS</b>One-hundred and twenty New Zealand rabbits of clean grade were divided into control group (C) and electric burn group (EB) according to the random number table, with 60 rabbits in each group. Rabbits in EB group were subjected to high-voltage electric burn (the electrical current flow into the left foreleg at the lateral side of proximal end and out from the corresponding site of the right hind leg) with voltage regulator and experimental transformer. Rabbits in C group were sham injured with the same devices without electrification. At 15 minutes before injury, and 5 minutes, 1, 2, 4, 8 hour (s) post injury (PIM or PIH), ten rabbits in each group were chosen to examine the cardiac apex microcirculation hemoperfusion (CAMH) with laser Doppler hemoperfusion image instrument. The morphologic changes of microvessels of left ventricular wall tissues of 2 rabbits from each of the 10 rabbits collected at above-mentioned time points were observed with light microscope and transmission electron microscope. Auricular vein blood of rabbit was harvested at above-mentioned time points for the determination of aspartate amino transferase (AST), lactate dehydrogenase (LDH), hydroxybutyrate dehydrogenase (HBDH), creatine kinase (CK), and creatine kinase isozyme MB (CK-MB) by full-automatic biochemical analyzer. Data were processed with two-factor analysis of variance and LSD test.</p><p><b>RESULTS</b>(1) The differences between C group and EB group in detection results were statistically significant, with F values from 425.991 to 3046.834, P values all below 0.01. Only the data within EB group were comparable. (2) At PIM 5, the CAMH value of rabbits in EB group was (1.96 ± 0.09) V, which was lower than that at 15 minutes before injury [(4.34 ± 0.35) V, P < 0.01]. The CAMH value of rabbits in EB group was increased at PIH 1 [(3.43 ± 0.30) V], and then it showed a tendency of decrease. (3) Bleeding and microthrombus formation were observed in venule and capillary vessel of rabbits in EB group at PIH 8. Breakage of basement membrane of capillary endothelial cells, mitochondrial swelling, and severe degranulation from damaged endoplasmic reticulum were observed in rabbits of EB group at PIH 8. (4) Levels of AST, LDH, HBDH, CK, and CK-MB in rabbits of EB group were significantly higher at PIH 1, 2, 4, 8 than at 15 minutes before injury (with P values all below 0.01). The AST level peaked at PIH 2 [(164 ± 39) U/L]. Levels of LDH and HBDH peaked at PIH 4, which were respectively (1016 ± 246) U/L and (487 ± 54) U/L. The CK level peaked at PIH 8 [(7799 ± 738) U/L]. The CK-MB level peaked at PIH 2 [(1848 ± 65) U/L].</p><p><b>CONCLUSIONS</b>High-voltage electric burn can bring damage to the microvessels of heart in rabbits and change blood flow of microcirculation, which should be given adequate attention during the treatment.</p>

Clinical effect of the concentrated suture fixation method on skin transplantation in the jaw and neck region / 中华烧伤杂志

<p><b>OBJECTIVE</b>To observe the clinical effect of the concentrated suture fixation method on skin transplantation on deep burn wound or wound of cicatricial deformity after burn in the jaw and neck region.</p><p><b>METHODS</b>One hundred and fourteen patients, hospitalized from April 2002 to December 2011, with deep burn or cicatricial deformity after burn in the jaw and neck region, were divided into packaging group and concentrated suture group according to the random number table. Each group had 57 patients including 48 cases with deep burn and 9 cases with cicatricial deformity. Traditional suture-package fixation method and concentrated suture fixation method were respectively used in packaging group and concentrated suture group to fix the autologous medium split-thickness skin in transplantation on wounds or scars. On post operation day (POD) 14, the skin microcirculatory perfusion flow of skin graft was measured, and the occurrence of ecchymoma, infection, and necrosis of skin in operative region were observed. The elasticity and contracture of grafted skin and scar hyperplasia on wound edge were observed 6 months after operation. Measurement data were processed with u test, while enumeration data with Fisher's exact test or Chi-square test.</p><p><b>RESULTS</b>(1) On POD 14, the skin microcirculatory perfusion flow in concentrated suture group [(2.86 +/- 0.8) V] was significantly higher than that in packaging group [(2.33 +/- 0.15) V, u = 17.776, P < 0.05]. (2) Ecchymoma occurred in 4 patients of packaging group and 3 patients of concentrated suture group, but the difference between two groups was not statistically significant (chi 2 = 0.152, P > 0.05). (3) Infection in operative region was observed in 1 patient of packaging group, while no patient in concentrated suture group showed this symptom. The difference between two groups was not statistically significant (P > 0.05). (4) Grafted skin in 6 patients of packaging group showed foliated necrosis, which was not observed on those of patients in concentrated suture group. The difference between two groups was statistically significant (P < 0.05). (5) Centipede leg-like scar hyperplasia on wound edge occurred in 21 patients in packaging group and 6 patients in concentrated suture group, and the difference between two groups was statistically significant (chi 2 = 10.920, P < 0.05). (6) Poor elasticity of grafted skin was detected in 17 patients of packaging group and 4 patients of concentrated suture group, and the difference between two groups was statistically significant (chi 2 = 9.865, P < 0.05). (7) Obvious contracture of grafted skin was observed in 15 patients of packaging group and 4 patients of concentrated suture group, and the difference between two groups was statistically significant (chi 2 = 11.684, P < 0.05).</p><p><b>CONCLUSIONS</b>Concentrated suture fixation method is suitable for application in transplantation of big sheet skin on wound in the jaw and neck region. It has high survival rate and is convenient for postoperative observation.</p>

Understanding molecular mechanisms for improving phytoremediation of heavy metal-contaminated soils.

Heavy metal pollution of soil is a significant environmental problem with a negative potential impact on human health and agriculture. Rhizosphere, as an important interface of soil and plants, plays a significant role in phytoremediation of contaminated soil by heavy metals, in which, microbial populations are known to affect heavy metal mobility and availability to the plant through release of chelating agents, acidification, phosphate solubilization and redox changes, and therefore, have potential to enhance phytoremediation processes. Phytoremediation strategies with appropriate heavy metal-adapted rhizobacteria or mycorrhizas have received more and more attention. In addition, some plants possess a range of potential mechanisms that may be involved in the detoxification of heavy metals, and they manage to survive under metal stresses. High tolerance to heavy metal toxicity could rely either on reduced uptake or increased plant internal sequestration, which is manifested by an interaction between a genotype and its environment.A coordinated network of molecular processes provides plants with multiple metal-detoxifying mechanisms and repair capabilities. The growing application of molecular genetic technologies has led to an increased understanding of mechanisms of heavy metal tolerance/accumulation in plants and, subsequently, many transgenic plants with increased heavy metal resistance, as well as increased uptake of heavy metals, have been developed for the purpose of phytoremediation. This article reviews advantages, possible mechanisms, current status and future direction of phytoremediation for heavy-metal-contaminated soils.

Endogenous hormonal and enzymatic responses of Catharanthus roseus with triadimefon application under water deficits.

The effect of triadimefon was investigated in a medicinal plant, Catharanthus roseus subjected to water deficit stress. The abscisic acid (ABA) level, DNA and RNA contents and activities of ATPase and protease were found varying in different parts of the plants under treatment. Drought treatment increased the ABA level more than twofold in all parts of the plants. TDM treatment to the drought stressed plants showed highest contents. In roots, stem and leaves, drought stress caused a decrease in the DNA and RNA contents when compared with control and other treatments. TDM treatment with drought increased the nucleic acid contents to the level of the control roots. The activity of ATPase and protease were increased under drought treatment and lowered due to TDM applications. This information could be useful in the field of soil water deficits reclamation efforts by using plant growth regulators.

Bioengineering plant resistance to abiotic stresses by the global calcium signal system.

Considerable progresses have taken place both in the methodology available to study changes in intracellular cytosolic calcium and in our understanding of calcium signaling cascades. It is generally accepted that the global calcium signal system functions importantly in coping with plant abiotic stresses, especially drought stress, which has been proved further by the recent transgenic and molecular breeding reports under soil water deficits. In plant cells, calcium plays roles as a universal transducer coupling a wide range of extracellular stimuli with intracellular responses. Different extracellular stimuli trigger specific calcium signatures: dynamics, amplitude and duration of calcium transients specify the nature, implication and intensity of stimuli. Calcium-binding proteins (sensors) play a critical role in decoding calcium signatures and transducing signals by activating specific targets and corresponding metabolic pathways. Calmodulin (CAM) is a calcium sensor known to regulate the activity of many mammalian proteins, whose targets in plants are now being identified. Higher plants possess a rapidly growing list of CAM targets with a variety of cellular functions. Nevertheless, many targets appear to be unique to higher plant cells and remain characterized, calling for a concerted effort from plant and animal scientists to elucidate their functions. To date, three major classes of plant calcium signals encoding elements in the calcium signal system, including calcium-permeable ion channels,Ca(2)+/ H(+) antiporters and Ca(2)+-ATPases, are responsible for drought stress signal transduction directly or indirectly. This review summarizes the current knowledge of calcium signals involved in plant abiotic stresses and presents suggestions for future focus areas of study.

Calcium as a versatile plant signal transducer under soil water stress.

The complexity of calcium profiles observed in plant cells has led to the realization that specific patterns of calcium propagation (now termed calcium signatures) encode specific information and relay it to downstream elements (effectors) for translation into corresponding cellular responses in higher plants. The concept of calcium signatures is now well established and the tight control of the temporal and spatial characteristics of cytosolic calcium alterations is considered to be responsible for the specificity of various cellular responses, in particular to environment-induced stresses. To date, three major classes of plant calcium sensors responsible for drought-stress signal transduction during soil water deficit have been identified. Valuable pieces of the calcium signal-specificity puzzle are being put together and are illustrated here for the calcium-mediated signal-transduction cascades that operate in the responses of higher plants to soil environmental deficits.

The mutual responses of higher plants to environment: physiological and microbiological aspects.

Higher plants are different from animals in many aspects, but the important difference may be that plants are more easily influenced by environment. Plants have a series of fine mechanisms for responding to environmental changes, which has been established during their long-period evolution and artificial domestication. The relationship between higher plants and environment is influenced mutually. The component in environment provides higher plants with nutrients for shaping themselves and higher plants simultaneously bring photosynthetic products and metabolites to surroundings, which is the most important part of natural circle. Photosynthetic products are realized mainly by physiological mechanisms, and microbiological aspects in environment (for instance, soil environment) impact the above processes greatly. The complete understanding of the relationship will extremely promote the sustainable utilization of plant resources and make the best use of its current potential under different scales.

Investigation on the relationship of proline with wheat anti-drought under soil water deficits.

Proline (content) is closely with plant anti-drought, especially under soil water deficits. Many reports from crops and other plants have proved this. Wheat is the second important crop on the globe, whose research in this aspect of importance for food quality, safety, and yield in field. The related difference in physiological indicators and proline content for different soil water treatments among wheat with different genotypes is not clear, which has limited deep study of wheat anti-drought molecular biology and related anti-drought biotechnological breeding. Our current study was focused on the physiological relationship of proline and different genotype wheat anti-drought under soil water deficits. Main results showed that different wheat genotype had different soil water stress threshold. Pro content had closed relationship with soil water stress threshold and wheat anti-drought. Developmental course also impacted Pro content for different wheat genotypes.

LEA proteins in higher plants: structure, function, gene expression and regulation.

Late embryogenesis abundant (LEA) proteins are mainly low molecular weight (10-30 kDa) proteins, which are involved in protecting higher plants from damage caused by environmental stresses, especially drought (dehydration). These findings and the fact that the breeding of drought tolerant varieties would be of great value in agriculture, form the basis of search for anti-drought inducible genes and their characterization. LEA proteins are generally classified into six groups (families) according to their amino acid sequence and corresponding mRNA homology, which are basically localized in cytoplasm and nuclear region. LEA protein synthesis, expression and biological activities are regulated by many factors (e.g. developmental stages, hormones, ion change and dehydration), signal transduction pathways and lea genes. No tissue-specific lea gene expression has been considered as one main regulatory mechanism on the basis of extensive studies with the model plant, Arabidopsisthaliana. The study of the regulatory mechanism of lea gene expression is an important feature of modern plant molecular biology.