DNA intercalation makes possible superior-gain organic photoelectrochemical transistor detection.

DNA intercalation has increasingly been studied for various scenario implementations due to the diverse functions of DNA/intercalators. Nascent organic photoelectrochemical transistor (OPECT) biosensing taking place in organic electronics and photoelectrochemical bioanalysis represents a promising technological frontier in the arena. In this work, we first devise DNA intercalation-enabled OPECT for miRNA detection with a superior gain up to 17100. Intercalation of [Ru(bpy)2dppz]2+ within the miRNA-initiated hybrid chain reaction (HCR)-derived duplex DNA is realized for producing anodic photocurrent upon light stimulation, causing the corresponding target-dependent alternation in gate voltage (VG) and hence the modulated channel current (IDS) of poly (3,4-ethylenedioxythiophene) doped with poly (styrene sulfonate) (PEDOT:PSS) under specific drain voltage (VDS) for quantitative miRNA-21 analysis, which shows a wide linear relationship and a low detection limit of 5.5 × 10-15 mol L-1. This study features the DNA intercalation-enabled organic electronics with superior gain and is envisaged to attract more attention to explore DNA adducts for innovative bioelectronics and biosensing, given the diverse DNA binders with multiple functions.

[Chemical Forms and Spatial Distribution of Phosphorus in the Sediment of Sihe River].

Based on the study of the content, forms, and spatial distribution of phosphorus (P) in the surface and columnar sediments of the Sihe River, the relationships between the total phosphorus (TP) and various forms of P and the basic physical and chemical properties of sediment and their ecological significance were deeply discussed. The forms of P in the sediment were defined including soluble and loosely bound P (S/L-P), Al-bound P (Al-P), Fe-bound P (Fe-P), reductant soluble P (RS-P), Ca-bound P (Ca-P), and residual P (RES-P) using the method of selectively sequential extraction. The results indicated that ω (TP) was 421.84-1188.65 mg·kg-1 in the surface sediment. Among the six forms of P, the content of Ca-P was the highest, accounting for more than 40% of TP, followed by the content of Fe-P, accounting for more than 20% of TP. The content of S/L-P was the lowest, which only accounted for approximately 0.4% of TP. The contents of TP and various forms of P in the surface sediments of the downstream area of the Sihe River were higher than those of the upstream area of the river, which was induced by the discharge of industrial wastewater and domestic sewage in the urban areas nearby the downstream portion of the Sihe River. The contents of TP in the upper samples of the two sediment profiles were obviously higher than those in the bottom samples, indicating that the P pollution in the water environment of the Sihe River has been intensifying in recent years. Among all forms of P in the sediment profiles, Ca-P accounted for the largest proportion, followed by Res-P. The correlation analysis results showed that significant correlations were observed between Fe and Fe-P, Al and Al-P, Ca and Ca-P, and TOC and RS-P in the surface sediments; the same correlations had not been found in the sediment profiles. The calculated results of Fe and TP molar ratio indicated that the sediments of the Sihe River could further accumulate P. The percentage of bioavailable P (BAP) in sediment was 25%-50%.

Preparation and Antimicrobial Activity of Antibacterial Silver-Loaded Polyphosphazene Microspheres.

Poly(cyclotriphosphazene-co-4,4'-diaminodiphenyl ether) (PPO) microspheres were prepared via a precipitation polymerization method, using hexachlorocyclotriphosphazene (HCCP) and 4,4'-diaminodiphenyl ether (ODA) as monomers. Silver-loaded PPO (PPOA) microspheres were generated by the in situ loading of silver nanoparticles onto the surface by Ag+ reduction. Our results showed that PPOA microspheres were successfully prepared with a relatively uniform distribution of silver nanoparticles on microsphere surfaces. PPOA microspheres had good thermal stability and excellent antibacterial activity towards Escherichia coli and Staphylococcus aureus. Furthermore, PPOA microspheres exhibited lower cytotoxicity when compared to citrate-modified silver nanoparticles (c-Ag), and good sustained release properties. Our data indicated that polyphosphazene-based PPOA microspheres are promising antibacterial agents in the biological materials field.

[Contamination Characteristics and Potential Ecological Risks of Typical Perfluoroalkyl Substances in the Water and Sediment of Coastal Tourism Resorts in Shandong Province].

Coastal tourism resorts have been developing rapidly in recent years, and the quality of their waterbodies directly affects human health. Perfluoroalkyl substances (PFASs) are found in every environmental medium and have garnered widespread social concern because of their potential ecological harm. This study investigated the contamination characteristics and potential ecological risks of 12 PFASs in the water and sediment of 20 coastal tourism resorts in Shandong Peninsula. The results revealed that all targeted pollutants were observed in the water and most sediment samples collected from the coastal tourism resorts. The sum of the 12 PFASs ∑PFASs averaged 67.91 ng·L-1 and 5.89 ng·g-1 in the water and sediment, respectively. The predominant compounds were perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) in both water and sediment. The ∑PFASs and its homologues concentration indicated the spatial variations in the water and sediment of different tourism resorts, and the values were higher in the tourism resorts near the city center and the industrial areas than in other areas. The partition coefficient (Kd) of all the target compounds in the water/sediment system of different tourism resorts showed obvious differences. In addition, the Kd of the compounds with longer carbon chains (C ≥ 7) generally had higher Kd values, which suggests that long-chain PFAAs are prone to adsorption by sediment. Therefore, the discharge of municipal industrial wastewater and domestic sewage is the main source of contamination. The salinity of water and the total carbon contents of sediment did not show any effect on the partition of PFASs in the water/sediment system. PFOS and PFOA might have great potential ecological risks in the water environment of all tourism resorts.

[Concentrations of Typical Perfluoroalkyl Acids and Contributions of Their Precursors in the Water of the Le'an River in China].

Transformation of perfluoroalkyl substance (PFASs) precursors and their contribution to PFASs pollution have become a subject of great research interest. The concentration of PFASs and their precursors and the transformation of precursors in the water samples collected from Le'an River and the effluents of sewage treatment plants (STPs) were investigated based on methods including hydroxyl radical (·OH) oxidation, extraction by solid phase, and ultra-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The results of the study revealed that the PFAS concentrations were in the range of 14.89-40.84 ng·L-1and 58.63-114.87 ng·L-1, and averaged 28.76 ng·L-1 and 86.75 ng·L-1 in the water of the Le'an River and the STP effluents, respectively. The compound with the highest concentration for the two kinds of waterbodies was perfluorooctanesulfonic acid (PFOS). The PFAS concentrations showed obvious spatial differences in the water of the Le'an River. After the oxidation treatment, the PFAS concentrations clearly increased in the two kinds of waterbodies. The increased concentrations of short-chain perfluorocarboxylic acids with carbon atom numbers of 4-8 (ΣΔï¼»PFCAC4-C8ï¼½oxidation conversion) were higher than those of compounds with long carbon chains. However, the increased concentrations of PFCAs for the STP effluents were higher than those for the river water. The transformation ratio obtained from the increased concentration of PFCAs led by the oxidation treatment against the PFCA concentration before oxidation (ΔPFCAoxidation conversion/PFCAbefore oxidation) was lower for the STP effluents than those for the water of Le'an River, which might be induced by the precursors' degradation during the sewage treatment process.

[Spatial Distribution of Perfluoroalkyl Acids and Transformation of Their Precursors in River Water Samples and Effluents of Wastewater Treatment Plans in a Typical Tourism City].

Perfluoroalkyl acids (PFAAs) are commonly detected in various environmental media and can cause potential risks to the ecological environment and human health. The levels and spatial distribution of 15 types of PFAAs and 3 types of PFAA precursors in the main river water and effluents of three sewage treatment plants (STPs) of Rizhao City were systematically investigated based on methods such as ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS), solid phase extraction and enrichment, and hydroxyl radical (·OH) oxidation to explore the pollution characteristics of PFAAs and the contribution of their precursors to environmental pollution in different water bodies of typical tourist cities. The results of this study reveal that 15 types of PFAAs and only perfluorooctane sulfoneamide (FOSA) among the precursors are detectable in most of the water samples. The total concentration of PFAAs (∑PFAAs) in the river water and sewage effluents is 3.79-45.58 ng·L-1 and 54.04-105.64 ng·L-1, respectively. The predominant PFAAs are perfluorooctanesulfonic acid (PFOS), perfluorohexanesulfonic acid (PFHxS), perfluorooctanoic acid (PFOA), and perfluorononanoic acid (PFNA). The ∑PFAAs value of the river samples is notably lower than that of sewage treatment plant (STP) effluents. An increasing tendency was observed from the upstream to the downstream of the rivers. After hydroxyl radical oxidation treatment, the PFAA concentrations of rivers and STPs increase notably. The increased concentrations of perfluorinated carboxylic acids (PFCAs) with 4-12 perfluoroalkyl carbon chains (∑△PFCAC4~C12) in the STP effluents are much higher than those in the river, which might be induced by the degradation of precursors during the sewage treatment processes. The results of this research provide basic data and technical support for environmental pollution prevention of new emerging pollutants in tourist cities.

Clinical application of a novel diagnostic scheme including pancreatic ß­cell dysfunction for traumatic multiple organ dysfunction syndrome.

A novel diagnostic scheme that includes pancreatic ß­cell dysfunction analysis for the diagnosis of traumatic multiple organ dysfunction syndrome (MODS) was investigated to assist in the early diagnosis and detection of MODS. Early intervention and treatment of MODS has been associated with a reduced mortality rate. A total of 2,876 trauma patients (including patients post­major surgery) were admitted to the intensive care unit of the authors' hospital between December 2010 and December 2015 and enrolled in the present study. There were 205 cases where the patient succumbed to their injuries. In addition to the conventional diagnostic scheme for traumatic MODS, indexes of pancreatic ß­cell dysfunction [fasting blood­glucose (FBG), homeostatic model assessment­ß and (blood insulin concentration 30 min following glucose loading­fasting insulin concentration)/(blood glucose concentration 30 min following glucose loading­FBG concentration)] were included to establish an improved diagnostic scheme for traumatic MODS. The novel scheme was subsequently used in clinical practice alongside the conventional scheme and its effect was evaluated. The novel scheme had a significantly higher positive number of MODS diagnoses for all trauma patients compared with the conventional scheme (12.48 vs. 8.87%; P<0.01). No significant difference was identified in the final percentage of positive of MODS diagnoses for trauma­associated mortality patients between the novel (88.30%) and the conventional scheme (86.34%). The novel scheme had a significantly higher positive number of MODS diagnoses for trauma­associated mortality patients 3 days prior to patients succumbing to MODS compared with the conventional scheme (80.98 vs. 64.39%; P<0.01). The consensus of the MODS diagnosis of all trauma patients between the novel scheme and the conventional scheme was 100%; however, out of the patients diagnosed as positive by novel scheme 71.03% were positive by the conventional scheme. The consensus between the final MODS diagnosis and the MODS diagnosis 3 days prior to patients succumbing to their injuries between the novel scheme and the conventional scheme was 100%; however, out of the patients diagnosed as positive by novel scheme 97.79 were positive by the conventional scheme of the 205 patients who succumbed to MODS and out of the patients diagnosed as positive for MODS by novel scheme 3 days prior to succumbing, 79.52% were positive by the conventional scheme. The results of the present study demonstrated that the novel diagnostic scheme using the relevant indexes of pancreatic ß­cell dysfunction for diagnosis of traumatic MODS, was able to diagnose MODS early without excessively extending the diagnostic scope. Its clinical application should be promoted.

Pharmacokinetic study and clinical evaluation of a slow-release 5-fluorouracil implant in pancreatic cancer patients.

The aim of this research was to study the pharmacokinetic characteristics of a slow-release 5-fluorouracil implant as well as to evaluate the clinical drug activity of this preparation in pancreatic cancer patients. Pharmacokinetic characteristics of the slow-release 5-fluorouracil implant were evaluated by examining the half-life time (T1/2) and apparent volume of distribution (Vd) in pancreatic cancer patients; the slow-release 5-fluorouracil implant was administered through interstitial chemotherapy (tumor interstitium implantation). In the drug activity study, 36 locally advanced unresectable pancreatic cancer patients were divided randomly into an experimental treatment group (n=18) and a standard treatment group (n=18). The experimental treatment group was treated with interstitial chemotherapy of a slow-release 5-fluorouracil implant combined with systemic chemotherapy of gemcitabine; the standard treatment group was treated with systemic chemotherapy of gemcitabine. An internal drainage procedure was used when biliary and/or gastrointestinal tract obstruction occurred in the two groups. Clinical benefit response, including pain (visual analogue scale), analgesic drug use, general conditions (Karnofsky performance score), weight changes, and survival status, was observed. T1/2 of the slow-release 5-fluorouracil implant was 5475.8±136.4 min, whereas Vd was 45275.0±1028.6 l. Clinical benefit response in the experimental treatment group was better than that in the standard treatment group. The experimental treatment group had longer median survival time compared with the standard treatment group. The slow-release 5-fluorouracil implant could deliver drugs mainly in the regional area of the tumor and prolong the drug action time; interstitial chemotherapy of a 5-fluorouracil implant combined with systemic chemotherapy of gemcitabine could improve the quality of life and survival status of pancreatic cancer patients. The method was promising and worthy of in-depth investigations.

Experimental study on sustained-release 5-Fluorouracil implantation in canine peritoneum and para-aortic abdominalis.

OBJECTIVE: To observe local and systemic toxicity after sustained-release 5-fluorouracil (5-Fu) implantation in canine peritoneum and para-aortic abdominalis and the changes of drug concentration in the local implanted tissue with time. METHODS: 300 mg sustained-release 5-Fu was implanted into canine peritoneum and para-aorta abdominalis. Samples were taken 3, 5, 7 and 10 days after implantation for assessment of changes and systemic reactions. High performance liquid chromatography was applied to detect the drug concentrations of peritoneal tissue at different distances from the implanted site, lymphatic tissue of para-aortic abdominalis, peripheral blood and portal venous blood. RESULTS: 10 days after implantation, the drug concentrations in the peritoneum, lymphatic tissue and portal vein remained relatively high within 5 cm of the implanted site. There appeared inflammatory reaction in the local implanted tissue, but no visible pathological changes such as cell degeneration and necrosis, and systemic reaction like anorexia, nausea, vomiting and fever. CONCLUSIONS: Sustained-release 5-Fu implantation in canine peritoneum and para-aortic abdominalis can maintain a relatively high tumour- inhibiting concentration for a longer time in the local implanted area and portal vein, and has mild local and systemic reactions. Besides, it is safe and effective to prevent or treat recurrence of gastrointestinal tumours and liver metastasis.

[Effects of panthenol-glutamine on intestine of rats with burn injury and its dose-effect relationship].

OBJECTIVE: To study the effects of the panthenol-glutamine on intestinal damage and motor function of intestine in rats with burn injury as well as its dose-effect relationship. METHODS: (1) Experiment 1. Ninety SD rats were divided into groups A-I according to the random number table, with 10 rats in each group. Rats in groups A-I were inflicted with 30% TBSA full-thickness burn and fed by gavage with panthenol and glutamine at post injury hour (PIH) 4, in the whole dosage of 1.00 and 4, 0.50 and 4, 0.25 and 4, 1.00 and 2, 0.50 and 2, 0.25 and 2, 1.00 and 1, 0.50 and 1, 0.25 and 1 g·kg(-1)·d(-1). The feeding was carried out twice a day to achieve the total dosage in 7 days. On drug withdrawal day, blood and intestinal tissue were harvested to detect the intestinal propulsion index, diamine oxidase (DAO) activity in serum, and the content of acetylcholine and intestinal mucosa protein. The best proportion of panthenol and glutamine was screened. (2) Experiment 2. Seventy SD rats were divided into normal control (NC), burn (B), burn+panthenol (B+P), burn+glutamine (B+G), and burn+low, moderate, or high dose of panthenol-glutamine (B+LPG, B+MPG, B+HPG) groups according to the random number table, with 10 rats in each group. Rats in the latter 6 groups were inflicted with 30% TBSA full-thickness burn. Rats in the latter 5 groups were fed by gavage with panthenol and (or) glutamine at PIH 4. Rats in group B+P were fed with panthenol for 1 g·kg(-1)·d(-1), rats in group B+G with glutamine for 4 g·kg(-1)·d(-1), rats in groups B+LPG, B+MPG, and B+HPG with panthenol and glutamine in the dosage of 0.50 and 2, 1.00 and 4, 2.00 and 8 g·kg(-1)·d(-1). The feeding was carried out twice a day to achieve the total dosage for 7 days. The indexes and time point for observation were the same as those of experiment 1. Meanwhile, the pathological change in intestine was observed. The same process was carried out in the rats of group NC. Data were processed with factorial designed analysis of variance (ANOVA), one-way ANOVA and Fisher's exact probability test. LSD was applied for paired comparison. RESULTS: (1) The values of intestinal propulsion index and intestinal mucosa protein content in groups A and B were close (with P values all above 0.05), and were significantly higher than those of the other 7 groups (with P values all below 0.01). Content of acetylcholine in group A was significantly higher than that of the other 8 groups (with P values all below 0.01). DAO activity in groups A, D, and E was close in value (with P values all above 0.05), and all of the values were significantly lower than those of the other 6 groups (with P values all below 0.01). The best proportion of panthenol and glutamine was 1.00 and 4 g·kg(-1)·d(-1). (2) Compared with those of group NC, the intestinal propulsion index, the contents of acetylcholine and intestinal mucosa protein were decreased significantly, while the DAO activity obviously increased in group B (with P values all below 0.01); the intestinal propulsion index was decreased significantly in group B+P (P < 0.01); the intestinal propulsion index and content of acetylcholine were decreased significantly in group B+G (with P values all below 0.01); the intestinal propulsion index was decreased significantly in group B+LPG (P < 0.01); no obvious change was observed in groups B+MPG and B+HPG (with P values all above 0.05). Compared with those of group B [0.50 ± 0.07, (69 ± 10) µg/mL, (26 ± 11) µg/g, (0.672 ± 0.145) U/mL], the contents of acetylcholine and intestinal mucosa protein were increased significantly, DAO activity decreased significantly in group B+P (with P values all below 0.01); the contents of intestinal mucosa protein was increased significantly, DAO activity decreased significantly in group B+G (with P values all below 0.01); the contents of acetylcholine and intestinal mucosa protein were increased significantly in group B+LPG (with P values all below 0.01); the intestinal propulsion index, the contents of acetylcholine and intestinal mucosa protein were increased significantly, while the DAO activity obviously decreased in groups B+MPG and B+HPG [0.66 ± 0.07, 0.68 ± 0.05; (163 ± 24), (168 ± 15) µg/mL; (57 ± 7), (57 ± 7) µg/g; (0.203 ± 0.070), (0.193 ± 0.068) U/mL, with P values all below 0.01]. The levels of the four indexes in groups B+MPG and B+HPG were close or the same in values (with P values all above 0.05). Compared with those of group B, the numbers of rats with irregularly arranged villi in group B+P were decreased significantly (P < 0.05); the numbers of rats with villi decreased in height, irregularly arranged villi, and neutrophil infiltration in group B+G were decreased significantly (with P values all below 0.05); the numbers of rats with villi decreased in height, irregularly arranged villi, degeneration and necrosis of cells, and neutrophil infiltration in group B+LPG were decreased significantly (with P values all below 0.05); the numbers of rats with villi decreased in height and number, irregularly arranged villi, degeneration and necrosis of cells, and neutrophil infiltration in groups B+MPG and B+HPG were decreased significantly (with P values all below 0.05). There was no statistically significant difference between group B+HPG and group B+MPG for the former mentioned five indexes (with P values all above 0.05). CONCLUSIONS: Combined application of panthenol and glutamine can obviously reduce intestinal mucosa damage and promote gastrointestinal motility of rats with burn injury, and they show curative effect superior to exclusive use of either of the two drugs. The best proportion of panthenol and glutamine is 1.00 and 4 g·kg(-1)·d(-1).

[A new concept of nutrition in treatment of burn injury: from nutrition support to nutrition therapy].

For many years, the major concerns in the treatment of a major burn injury have always been shock resuscitation, infection control, and wound treatment, while nutrition has been considered as a subordinate concern. The concept of nutrition in the treatment of a major burn has been recognized as "nutrition support", only with the purpose of restraining negative nitrogen balance through administration of energy and protein, in order to prevent malnutrition in patients with severe burn. In recent 10 years, however, increasing evidences have showed that optimal nutritional management could improve the outcome of severe burn patients. Now it is recognized that nutrition is not only to provide exogenous nutrients to improve nutritional status of the patients, but also to regulate cell metabolism, enhance cell activity, maintain and uphold the structure and function of the gastrointestinal mucosa, thus to improve patient's outcome. Therefore, the term of "nutrition support"seems to be far from comprehensiveness to reflect the purpose and the aim of this important treatment strategy. Medical literatures especially those in nutritional guidelines have begun to use the term of "nutrition therapy" instead of "nutrition support", which typifies the changes in nutritional concept, aim, means, and clinical evaluation. The aim of nutrition has changed from simply "providing nutritional substrate and improving nutritional status of patients" to "regulating cell metabolism, maintaining organ structure and function, and ultimately improving outcome of patient". Meanwhile, nutritional means has been more consummate, including special nutrients, hormones, and growth factors, in addition to use of conventional nutrients, in order to enhance therapeutic effect of nutrition in treatment of massive burn injury. Burn nutrition is no longer confined to maintenance of positive nitrogen balance, it should also consider the regulation of cell activity, metabolic status, immune and organ function. The purpose of the article is to analyze and discuss the important issues concerning nutrition therapy in treatment of burn injury, including risk screening, optimal energy supply and ratio of different nutritional ingredients, the choice of special nutrient, as well as the determination of optimal time for giving various nutritional supplements.

[Mechanism of changes in intestinal epithelium permeability and its countermeasure after burn injury].

After a series of studies, we found that the intestinal permeability was increased, tight junction protein (zonula occluden-1) obviously decreased and redistributed, accompanied by an increase in expression of myosin light chain (MLC) phosphorylation in severely burned rats. After using inhibitor of MLC kinase (ML-9 2 mg/kg) or of Rho-associated kinase (Y-27632 2 mg/kg), above-mentioned changes could be alleviated. Therefore, to regulate the MLC phosphorylation of tight junction protein and perijunctional actin-myosin ring may be one of the key links to lessen the intestinal epithelium permeability after burn injury.

Therapeutic effectiveness of slow-release PLGA-oxaliplatin microsphere on human colorectal tumor-bearing mice.

The aim was to develop a slow-release poly-lactic-coglycolic acid (PLGA)-oxaliplatin microsphere and to assess the therapeutic effectiveness and safety of this preparation on colorectal tumor in vivo. The PLGA-oxaliplatin microsphere was prepared based on a spray-drying method, and the drug loading and in-vitro oxaliplatin release profile were carried out using high performance liquid chromatography. The inhibiting effect on tumor growth was examined using in-vivo subcutaneously inoculated colorectal tumor models of nude mice. The size of the microsphere was less than 100 microm, drug loading was 18-22% and drug release time lasted as long as 30 days. PLGA-oxaliplatin microspheres significantly restrained tumor growth and this effect correlated with decreased expression of proliferating cell nuclear antigen and increased expression of terminal deoxynucleotidyltransferase dUTP nick end labeling in tumor cells. Bodyweight measurement and blood analysis did not suggest significant adverse effects on the mice during the study. The PLGA-oxaliplatin microsphere developed here was suitable for regional use; it appears safe and effective in controlling the tumor growth. This preparation shows promise in reducing local recurrence of colorectal cancer after resection, but needs further investigation.

[Glutamine and immunonutrition for burn patients].

Nutritional therapy is an important determinant of immune function in burn patients. However, common nutritional supplement given to patients with extensive deep burn is still therapeutically inefficient to block nutrients utilization due to metabolic disorder. Immunonutrition, a new nutrition therapeutic modality, has been used in severely burned patients for regulating cell function, improving metabolic state, and enhancing immune function. Glutamine (Gln) is often considered to be a prime immunonutrient in immunonutrition therapy for critically ill patients including those with serious burns. Our series of experimental and clinical studies have demonstrated that Gln administered in animals or patients could abate intestinal injury, accelerate repair of intestinal mucosa, improve nitrogen balance, abate immunosuppression, maintain immune homeostasis, ameliorate wound healing, and shorten hospital stay. Although the use of Gln for supportive care of severely burned patients is now well established, the science of its use is still in its infancy. There are some disputes in regard to its indication, dosage, and course of treatment, and the way of its supplementation, administration opportunity especially. These questions will be discussed in this paper, and we wish to propose the principle and method of administration of Gln in severely burned patients.

[Effects of different doses of L-arginine on the serum levels of helper T lymphocyte 1 (Th1)/Th2 cytokines in severely burned patients].

OBJECTIVE: To investigate the effects of L-arginine in different doses on the serum levels of helper T lymphocyte1 (Th1)/Th2 cytokines in severely burned patients. METHODS: Twenty-nine severely burned patients, with total burn surface area from 50% to 80%TBSA, hospitalized within 20 hours after burn, were randomly divided into control group (10 cases, fed with 5% glucose saline 500 mL), L-arginine 200 mg group (10 cases, fed with 5% glucose saline 500 mL + 200 mg/kg L-arginine), L-arginine 400 mg group (9 cases, fed with 5% glucose saline 500 mL + 400 mg/kg L-arginine). All patients received enteral feeding through nasointestinal tube, started within 22 hours after burn. Fasting venous blood of all patients was harvested on post burn day (PBD) 1 (before enteral feeding), 3, 5, and 7 to determine serum contents of TNF-alpha, IL-1beta, TGF-beta(1) and IL-4 by radio-immunity method and enzyme-linked immunosorbent assay. RESULTS: Serum contents of TNF-alpha and IL-1beta of patients in all groups increased rapidly after burn, and although contents of TNF-alpha (318 +/- 57) ng/mL and IL-1beta (218 +/- 47) pg/mL of patients in L-arginine 200 mg group peaked on PBD 5, they were still significantly lower than those of patients in control group [(389 +/- 34) ng/mL, (272 +/- 40) pg/mL, P < 0.05], but they decreased on PBD 7. Serum contents of TNF-alpha and IL-1beta in L-arginine 400 mg group were close to those of control group (P > 0.05). Serum contents of TGF-beta(1) and IL-4 of patients in each group increased slowly after burn, and content of TGF-beta(1) (110 +/- 16) pg/mL of patients in L-arginine 200 mg group was significantly higher than that of patients in control group [(83 +/- 20) pg/mL, P < 0.05] on PBD 5. There was no statistical significant difference between L-arginine 400 mg group and control group in respect of serum content of TGF-beta(1) (P > 0.05). CONCLUSIONS: Compared with the dosage of 400 mg/kg L-arginine, the 200 mg/kg dose is more effective in reducing the release of Th1 cytokines and increasing Th2 cytokines production, hence maintaining Th1/Th2 cytokine ratio to produce better immune opsonization during the infection phase of severe burn.

[Chemical forms and distribution of phosphorus in the sediment profiles of the Daliaohe River systems].

The Daliaohe river system in China has been seriously affected by long-term intensive industrial, urban and agricultural activities. The objective of this study was to determine the total phosphorus (TP) content and forms of phosphate in the sediments and investigate geochemical relationships between P forms and mineral matrix elements and P bioavailability. Four sediment profiles were taken in the Daliaohe river systems. TP content in the sediment was measured by ICP-OES and chemical forms of phosphate were measured by sequential selective extraction method. Results indicated that TP ranged from 323 to 2619 mg x kg(-1). In the sediments except 25-47 cm depth of sediment profile in the Hun river, the content of Ca bound P (Ca-P) was the highest, with more than 40% of TP. The contents of Fe bound P (Fe-P) and residual P (RES-P) were 15% to 25% of TP, while the contents of reductant soluble P (RS-P) and Al bound P (Al-P) were generally 5% to 10% of TP. However, the content of soluble and loosely bound P (S/L-P) was only less than 0.5% of TP. Huge accumulation of P in the 25-47 cm depth of the sediment profile in the Hun river led to a bigger increase in the contents of Fe-P and Al-P than Ca-P, where Al-P, Fe-P and Ca-P contents were 6.2%-23.4%, 19.6%-34.1% and 14.6%-35.6% of TP, respectively. Correlation analysis showed that sum of Fe-P and RS-P, Ca-P, and RES-P were positively correlated to Fe, Ca, and sediment organic matter (SOM) contents, respectively in the sediments except the 25-47 cm depth of sediment profile in the Hun river. In addition, TP content was positively correlated to Fe and SOM contents. The molar ratios of Fe to TP generally ranged from 20.9 to 33.9, indicating that most of sediments have capability to further retain P. Potential bioavailable P (BAP) including S/L-P, Al-P and Fe-P in the sediments was 85.43 to 1830.5 mg x kg(-1), and this part of phosphorus might pose a potential risk to the eutrophication of the Daliaohe river system and its estuary.

[Achievements in burn surgery over the past 50 years in China].

This paper reflects briefly the main advancements of clinical and scientific research in the field of burn surgery over the past 50 years in China. It includes emergency care of massive burns, resuscitation, anti-infection, prevention and treatment of internal organ injury, metabolic and nutritional support, repair of wound and rehabilitation, and special types of burns. The article also covers the researches in pathology, microbiology, immunology, cell biology, molecular biology, and tissue engineering pertaining to burn injury.

[Progress of burn research in metabolism and nutrition in China].

The achievements of burn metabolism and nutrition in China are briefly presented. Advance a new theory "Enterogenous Hypermetabolism". Develop a formula to calculate calorie needs in Chinese burn adults. Put forward new ideas on glucose absorption, neo glycogenesis, insulin resistance, and the use of hypoglycemic agent after burn injury. Observe the variation of plasma level of free aminoacids, investigate the changes and mechanisms of 26S proteasome and 19S regulator in skeletal muscle of burn trauma, and the clinical application and its mechanism of glutamine and arginine. Introduce the approach of (13)C NMR spectroscopy to investigate the alterations of hepatic anabolism functions in severely burned rats. Offer supplying the suitable dosage of vitamin A, C, E and microelement of zinc, copper, ferrum for burn patients. Carry out serial studies of early enteral and parenteral nutrition, and compare enteral nutrition with parenteral nutrition. Early enteral nutrition with synbiotics might be beneficial to the controlling of burn infection. Both glucagon like peptide-2 (GLP-2) and intestinal trefoil factor (ITF) exhibit protective effect on intestinal mucosa in minimizing injury and protecting barrier function. The choice of suitable opportunity to use rhGH (growth hormone) is investigated. In addition, advance the view points of ischemia and anoxia in metabolism, anti-inflammatory immune and nutrition.

[How to evaluate energy requirement of burn patients ---- a question still needs farther investigation].

After a series of study of early feeding (EF), we consider the evaporative heat loss from the burn wound is not the main mechanism of burn hypermetabolism. EF could resuscitate the intestine, preserve its structural integrity and function, prevent bacterial translocation and release of inflammatory mediators, reduce muscle protein catabolism and hypermetabolism. Our studies concerning the relationship between EF and hypermetabolism have already extended to involve hypothalamus now. At the end of 1960s, the advancement in "Intravenous Hyperalimentation" has epoch-making significance, but it has been found later that energy has been oversupplied by this measure, thus it exacerbated visceral loading and led to disorder of internal environment, and it has been found not beneficial to alleviate hypermetabolism. Whether "hypocaloric nutrition" for post-operative patients of G-I (gastro-intestine) surgery is applicable to severe burn patients remains as a problem. Some specialists suggest it is better to supply 126 approximately 146 kJxkg(-1)x d(-1) in severe burn patients. After evaluating the bias and precision of 46 methods of estimating energy supply of burn patients reported from 1953 to 2000, Dickerson RN et al. concluded that the most precise, unbiased methods were those of Milner (1994), Zawacki (1970) and TMMU (1993, Third Military Medical University formula). Though formulas are simple and convenient to estimate energy supplementation, however, it is difficult to evaluate the requirement of energy when the patient's condition changes immensely.

[Role of corticotropin releasing factor receptor 2 antisense oligodeoxynucleotide of hypothalamus in hypermetabolism in rats with severe burn].

OBJECTIVE: To observe the role of corticotropin releasing factor receptor 2 antisense oligodeoxynucleotide (CRFR2ASO) of hypothalamus in hypermetabolism in rats with severe burn. METHODS: Stainless-steel cannula were implanted into the 3rd ventricle. According to different medicine delivered into the 3rd ventricle, 30 SD rats with 30% TBSA full-thickness burn were divided randomly into burn control group (BC, with injection of 3 microL saline), CRFR1ODN group (with injection of CRFR1ODN 10 microg), CRFR1ASO group (with injection of CRFR1ASO 10 microg), CRFR2ODN group(with injection of CRFR2ODN 10 microg), CRFR2ASO group (with injection of CRFR2ASO 10 microg), with 6 rats in each group. Another 6 rats served as normal control (NC) and they received isotonic saline 3 microL instead. Different medicines were respectively delivered into respective group on 5, 6 post injury day (PID), then 3 microL gentian violet was introduced on 7 PID. Resting energy expenditure (REE) value and the expression level of hypothalamus CRFR2mRNA and CRFR2 protein were determined. RESULTS: REE value in BC, CRFR1ODN, CRFR1ASO, CRFR2ODN, CRFR2ASO groups was 11 840 +/- 987, 11 133 +/- 1100, 10 733 +/- 1338, 11 123 +/- 1321, 7563 +/- 890 kJx(m2)(-1)xd(-1), respectively, which were obviously higher than that in BC group [6641 +/- 526 kJx(m2)(-1)xd(-1), P < 0.05]. REE value in CRFR2ASO group was obviously lower than that in CRFR2ODN group (P < 0.01). The expression level of hypothalamus CRFR2 mRNA and its protein in BC group were increased after burn, which were obviously lower in CRFR2ASO group than NC group (P < 0.01). CONCLUSION: Central application of CRFR2ASO can downregulate the expression level of hypothalamus CRFR2 mRNA and its protein, and reduce hypermetabolism. Hypothalamus CRFR2 may mediate hypermetabolism in burn rats.