ABSTRACTHydrogen sulfide (H2S) is synthesized in the body from l‐cysteine by several enzymes including cystathionine‐γ‐lyase (CSE). To date, there is little information about the potential role of ...H2S in inflammation. We have now investigated the part played by H2S in endotoxin‐induced inflammation in the mouse. E. coli lipopolysaccharide (LPS) administration produced a dose (10 and 20 mg/kg ip)‐ and time (6 and 24 h)‐dependent increase in plasma H2S concentration. LPS (10 mg/kg ip, 6 h) increased plasma H2S concentration from 34.1 ± 0.7 µM to 40.9 ± 0.6 µM (n=6, P<0.05) while H2S formation from added l‐cysteine was increased in both liver and kidney. CSE gene expression was also increased in both liver (94.2±2.7%, n=6, P<0.05) and kidney (77.5±3.2%, n=6, P<0.05). LPS injection also elevated lung (148.2±2.6%, n=6, P<0.05) and kidney (78.8±8.2%, n=6, P<0.05) myeloperoxidase (MPO, a marker of tissue neutrophil infiltration) activity alongside histological evidence of lung, liver, and kidney tissue inflammatory damage. Plasma nitrate/nitrite (NOx) concentration was additionally elevated in a time‐ and dose‐dependent manner in LPS‐injected animals. To examine directly the possible proinflammatory effect of H2S, mice were administered sodium hydrosulfide (H2S donor drug, 14 µmol/kg ip) that resulted in marked histological signs of lung inflammation, increased lung and liver MPO activity, and raised plasma TNF‐α concentration (4.6±1.4 ng/ml, n=6). In contrast, dl‐propargylglycine (CSE inhibitor, 50 mg/kg ip), exhibited marked anti‐inflammatory activity as evidenced by reduced lung and liver MPO activity, and ameliorated lung and liver tissue damage. In separate experiments, we also detected significantly higher (150.5±43.7 µM c.f. 43.8±5.1 µM, n=5, P<0.05) plasma H2S levels in humans with septic shock. These findings suggest that H2S exhibits proinflammatory activity in endotoxic shock and suggest a new approach to the development of novel drugs for this condition.
Parasitological techniques (stool examination and/or urine filtration) are still the diagnosis of choice in national schistosomiasis control programmes the world over. However, the success of current ...control efforts, mainly due to the large-scale administration of praziquantel, emphasises the need for a more sensitive approach. In addition, microscopy is labour-intensive and time-consuming, while declining compliance rates after repeated chemotherapy make good coverage for the long-term increasingly problematic. China's success in the control of schistosomiasis is contributing to an enhanced understanding of the need for better and more sensitive screening methods. Immunodiagnostic techniques have a high sensitivity, are easy to perform and are an excellent epidemiological tool for the screening of target populations in schistosome-endemic areas. These assays are also useful for the surveillance of cure after chemotherapy, and for periodic control of transmission of the infection after it has been eliminated in an area. A succinct historical background of using immunodiagnosis for schistosomiasis japonica in China is given, together with a review and evaluation of the relative efficacy of the main techniques applied, i.e. the intradermal test, the circumoval precipitation test, the indirect hemagglutination assay, the dye dipstick immunoassay and different kinds of enzyme-linked immunosorbent assay applications. The important role of immunodiagnosis in the screening for schistosomiasis in China is discussed.
Estimation of a single-input single-output block-oriented model is studied. The model consists of a linear block embedded between two static nonlinear gains. Hence, it is called N–L–N ...Hammerstein–Wiener model. First, the model structure is motivated and the disturbance model is discussed. The paper then concentrates on parameter estimation. A relaxation iteration scheme is proposed by making use of a model structure in which the error is bilinear-in-parameters. This leads to a simple algorithm which minimizes the original loss function. The convergence and consistency of the algorithm are studied. In order to reduce the variance error, the obtained linear model is further reduced using frequency weighted model reduction. Simulation study will be used to illustrate the method.
Recently, intense interest has focused on the antioxidant properties of natural products. In particular, Chinese herbal medicines (CHM) have become hot topics for life science researchers since many ...are reported to possess cardioprotective compounds, many of which remain to be identified. Indeed, the exact mechanisms by which CHM work remain unknown. Although many of these herbal remedies are undoubtedly efficacious, few have been scientifically investigated for their active chemical constituents and biological activities. We have previously reported higher activities of antioxidant defence enzymes such as superoxide dismutase, catalase, glutathione peroxidase and glutathione S-transferases in the liver of rats treated with the herb Salvia miltiorrhiza in a model of acute myocardial infarction. Using well established in vitro antioxidant assays employing 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) and diphenyl-l-picrylhydrazyl (DPPH) we have shown that in addition to elevating endogenous antioxidant enzyme activity, Salvia miltiorrhiza and other CHM traditionally used for cardiovascular disorders (such as Rhizoma ligustici, Herba leonuri, Radix achyranthis bidentatae, and Camellia sinensis) contain potent antioxidant moieties in addition to their phenolic constituents. Furthermore, these novel non-phenolic components are effective inhibitors of oxidative reactions mediated by the inflammatory oxidants, peroxynitrite,hypochlorous acid and hydroxyl radical as well as iron-dependent lipid peroxidation. In this review, we discuss the various antioxidant properties of CHM in the context of their biochemical mechanisms.
Drowning is common worldwide. Rescue efforts attempted by untrained bystanders often lead to the death of the primary drowning victim (PDV), the rescuer or both. Our study aimed to inform prevention ...by identifying risk factors in rescuer drowning.
Data on drowning rescue incidents reported online in mainland China, 2013, were reviewed. Information on the drowning incidents, PDVs and rescuers were retrieved for analysis.
A total of 225 rescue incidents were identified, of which 14 were victim-rescuer drowning incidents (VRDIs) (6.2%). A person-to-person rescue by swimming to PDVs was the most commonly used method (58.9%). Resuscitation was given immediately to 35.5% of PDVs after rescue. The mortality rate of the rescuers (13.3%) was similar to that of the PDVs (11.5%) (χ(2) = 0.5, p =0.49). Being an adult (OR = 0.2, 95% CI: 0.1-0.5) and other than the first rescuer (OR = 0.4, 95% CI: 0.2-0.9) decreased the risk of rescuers drowning.
Most of the currently employed life-saving methods are dangerous and even potentially life threatening. The idea of "rescuers' safety first" should be embraced, especially with teenage and child rescuers, who should never be encouraged to rescue others without first guaranteeing their own safety. Promotion of basic rescue skills should be implemented in the general public.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Single-crystal ZnSe nanowires have been synthesized via a thermochemical method in a N
2 atmosphere with CO and H
2 gases. The as-prepared ZnSe nanowires have a mean diameter of 40 nm and a length of ...1 μm. The nanowires are single crystals with a hexagonal structure growing along the 0
0
1 direction. A self-catalyzed vapor–liquid–solid process is proposed for the formation of such nanowires. The as-prepared nanowires show two emission bands at ca. 447 and 617 nm.
•Magnetization AC losses in iron based superconducting composites were studied.•Temperature was varied from 20 K to 42 K.•External magnetic field of frequencies 72 Hz and 144 Hz up to 70 mT was ...applied.•Parallel as well as perpendicular field orientation was examined.•Effect of eddy currents in Ag sheath were observed.
Magnetization AC loss measurements of singe- and seven-core Ba122/Ag tapes have been done by calibration-free method in the range of temperature from 20 K to 42 K and field magnitudes up to 70 mT in RMS with two frequencies 72 Hz and 144 Hz. A strong effect of eddy current losses in highly conductive Ag sheath was observed for single-core sample, but negligible for seven-core tape with more resistive AgSn alloy outer sheath. For the estimation of eddy current loss component, pure Ag foil was measured in the same range of temperatures and used for analytical subtraction from the total losses of Ba122/Ag. In addition, loss measurement of singe-core sample with chemically etched away Ag sheath was also done. AC loss measurements in perpendicular as well as parallel field orientation have shown a strong effect of the filament size.
Nanocable-Aligned ZnS Tetrapod Nanocrystals Zhu, Ying-Chun; Bando, Yoshio; Xue, Dong-Feng ...
Journal of the American Chemical Society,
12/2003, Letnik:
125, Številka:
52
Journal Article
Recenzirano
An effective method for synthesizing ZnS-core/carbon-sheath nanocables and nanocable-aligned ZnS tetrapod nanocrystals has been developed. Nanocable heterostructures and nanocable-linked ZnS ...tetrapods were synthesized in a controllable way. The tetrapods are single crystalline cubic ZnS with triangular-prism branches stretching out in four {111} directions. The tetrapods were aligned together with ZnS−C nanocables along the 100 direction.
Background: Potent immune-suppressive therapy has been demonstrated to increase the risk of infective endocarditis (IE) in renal recipients. Reports of Corynebacterium striatum (C. striatum) ...endocarditis in renal recipients are scarce, thus limiting understanding of the disease. Case Presentation: We describe a case of native valve endocarditis caused by C. striatum in a 35-year-old male patient. The young man with end-stage renal failure underwent kidney transplantation because of autosomal dominant polycystic kidney disease. Ceftazidime was administered after the surgery according to routine procedures, and the patient was discharged on the 14th day after the surgery without any evidence of infection. The patient experienced fever on the 56th day, and Corynebacterium was cultured from the patient’s blood, in agreement with the results of testing of the donor kidney preservation solution. On the 64th day, multiple thromboses were found in the right external iliac artery, particularly around the anastomotic orifice of the transplanted renal artery. Vegetation was found in the posterior mitral valve tip on the 65th day. The patient had symptoms of persistent angina pectoris and chest tightness and underwent mitral valve replacement and vegetative resection. The patient eventually died. C. striatum was detected in the mitral valve and vegetation tissue with metagenomic next-generation sequencing. Conclusion: C. striatum may cause endocarditis and endanger patients’ lives and thus warrants greater attention. Genotypic assays such as metagenomic next-generation sequencing are demonstrated to be effective in confirming species identity. Adequate anti-infection therapy and early surgery are required after IE is discovered.
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