Comparative effects of the herbicide dinitro-o-cresol on mitochondrial bioenergetics     

Joaquim A. F. Vicente  Maria S. Santos  Anibal E. Vercesi  Vítor M. C. Madeira 《Pest management science》1998,54(1):43-51

The herbicide dinitro-o-cresol (DNOC) was evaluated for its effects on bioenergetic activities of potato tuber mitochondria to elucidate its mechanism of action and to compare its toxicological properties with those of the chemically related uncoupler dinitrophenol (DNP). DNOC acts as a typical uncoupler, similarly to the classical uncouplers DNP and carbonylcyanide p-trifluoromethoxyphenyl-hydrazone (FCCP). Low concentrations of DNOC (<100 μM ) maximally stimulate succinate-supported respiration of plant mitochondria, with simultaneous collapse of trans-membrane electrical potential, more efficiently than DNP. The herbicide makes the plant mitochondrial membrane more permeable to protons, acting as a protonophore even in non-energized mitochondria. High concentrations of DNOC (>100 μM ) act also more efficiently than DNP simultaneously as a protonophore and inhibitor of respiration, especially when respiration is supported by substrates that are transported to the matrix. The efficiency of DNOC is decreased with increase of mitochondrial protein, BSA and exogenous orthophosphate. Although similar effects were observed for animal and plant mitochondria, rat-liver mitochondrial respiration was more sensitive to DNOC than plant mitochondria. Furthermore, in the presence of DNOC, liver mitochondria exhibited a higher state 3 respiratory coupling level than potato tuber mitochondria, as a result of a considerable stimulation (60%) of state 3 respiration. In conclusion, DNOC is a more potent mitochondrial uncoupler and respiratory chain inhibitor than DNP, although their chemical structures are very similar. Apparently, the additional methyl group of DNOC increases its efficiency as an uncoupler and as an inhibitor, as compared to DNP. Plant mitochondria were shown to be as useful as animal mitochondria in evaluating the toxicity of these xenobiotics. © 1998 Society of Chemical Industry.  相似文献   

A suspected case of acute copper toxicity in a horse     

DE AUER  JC NG  AA SEAWRIGHT 《Australian veterinary journal》1989,66(6):191-192

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Vascular leakage induced by histamine, bradykinin, serotonin and prostaglandin E₂ in Greyhounds     

PC MILLS  JC NG  AA SEA WRIGHT  DE AUER 《Australian veterinary journal》1993,70(1):21-24

SUMMARY Vascular leakage induced by intradermal injection of histamine, bradykinin and serotonin alone and co-injected with prostaglandin E₂ was measured in Greyhounds using ¹²⁵Iodine-labelled human serum albumin (¹²⁵I-HSA) as a marker in the blood. Histamine and bradykinin produced dose-dependent vascular leakage. At equimolar concentrations, histamine was more than twice as potent as bradykinin. Serotonin did not induce vascular leakage and was irritant. Prostaglandin E₂ did not induce significant vascular leakage (maximum 5μL) when injected alone, but when co-injected with histamine and bradykinin, the vascular leakage of both histamine and bradykinin was increased. This effect was more pronounced if lower concentrations of histamine and bradykinin were injected. The induced vascular leakage was greatest during the first five minutes of lesion development for histamine, during the second five minutes of lesion development for bradykinin, and the synergistic effect of prostaglandin E₂ was maximal during the third five minute period of lesion development.  相似文献   

Pathogenicity of Nectria galligena (Bres.)     

K. W. NG  E. T. ROBERTS 《Plant pathology》1974,23(1):49-50

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海南石灰岩植被的分布与保育概况   总被引：1，自引：0，他引：1  

张荣京  秦新生  邢福武  陈红锋  吴世捷 《热带林业》2007,35(Z1)

在野外调查统计的基础上,阐述了海南石灰岩植被的分布、植被的基本特征和植被类型概况,初步给出6种主要植被类型和7种群系.最后对植被的保育进行分析,并给出对策.  相似文献   

Wood ash effects on nutrient dynamics and soil properties under Mediterranean climate     

María X. Gómez-Rey  Manuel Madeira  Jo?o Coutinho 《Annals of Forest Science》2012,69(5):569-579

Aims

This study aims to evaluate the effects of wood ash application on nutrient dynamics and soil properties of an acidic forest soil (Arenosol).

Methods

Treatments were loose and pelleted ash application (11?Mg?ha^?1), alone or together with N fertiliser, and control treatment in a lysimeter experiment. Nutrient leaching was followed during a 2-year period and soil chemical and biological properties were evaluated at the end of the experiment.

Results

Wood ash increased leaching of total N, NH ₄ ⁺ -N, base cations and P, mainly during the first months, the effect being more pronounced for the loose formulation. At the end of the study period, a positive effect on soil nutrient availability and soil acidity reduction was seen. The application of loose and pelleted ash alone decreased N leaching and increased N microbial biomass at the end of the experiment. The C dynamics was weakly affected.

Conclusion

Wood ash can be used to improve nutrient availability and balance nutrient exported by tree harvesting in acid forest soils, the effects at short-term being stronger for loose than for pelleted ash. However, their application should be carried out when vegetation is established to minimise nutrient losses at short-term and reduce the potential risk for water bodies. In N-limited soils, wood ash should be applied with N fertilisers to counteract N immobilisation.  相似文献   

Effect of Qidan on the expression of transforming growth factor-β1 an d tumor necrosis factor-α in a rat model of bleomycin-induced pulmonary fibros is     

JIN Chang-jun  XIN Hong-tao  LIN Dian-jie  MU Xiao-yan  XV Shao-hua  WA NG Zhen 《园艺学报》2006,22(4):814-817

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Effects of inflammation-associated acute-phase response on hepatic and renal indices in the horse   总被引：1，自引：0，他引：1  

PC MILLS  DE AUER  H. KRAMER  D. BARRY  JC NG 《Australian veterinary journal》1998,76(3):187-194

Objectives To determine the effect of an acute soft tissue inflammatory response on biochemical and haematological indices of hepatic and renal function in the Thoroughbred horse.
Procedure Soft tissue inflammation was induced in four Thoroughbred horses by intramuscular injections of Freunds complete adjuvant. The horses were clinically examined and blood and urine samples were collected before and after the adjuvant injections. Biochemical and haematological indices were measured in samples collected and used to determine the onset of the acute-phase response and to assess hepatic and renal function at this time.
Results After adjuvant injection, significant increases (P< 0.01) in total white (13.1 ± 1.4 times 10⁹/L) and neutrophil (10.2 ± 1.2 times109/L) cell counts, rectal temperature (39.7 ± 0.5A°C) and various plasma protein concentrations, including fibrinogen (6.6 ± 1.2 g/L), haptoglobin (1.3 ± 0.1 g/L) and total protein (88.1 ± 2.7 g/L), indicated the induction of an acute-phase response. This corresponded with significant reductions (P< 0.01) in the plasma elimination half-lives (t½β) sodium bromo-sulphthalein (3.13 ± 0.05 to 2.82 ± 0.07 min) and sodium sulphanilate (38.29 ± 4.04 to 19.60 ± 5.68 min) and reductions in the plasma activities of aspartate aminotransferase, gluta-mate dehydrogenase, creatine kinase, alkaline phosphatase, gamma glutamyl transferase; the urinary creatinine clearance ratios of sodium, chloride and potassium; and the urinary gamma glutamyl transferase-to-creatinine clearance ratios. (All values mean ± SD.)
Conclusions The effects of the acute-phase response on indices of hepatic and renal function in the horse suggest that the disposition of pharmacological agents administered at this time may be altered and that indices of acute inflammation should be interpreted cautiously.  相似文献   

Membrane partitioning of organophosphorus and organochlorine insecticides and its implications for mechanisms of toxicity     

Maria Do Carmo Antunes-Madeira  Vitor M. C. Madeira 《Pest management science》1989,26(2):167-179

Partition coefficients of organophosphorus and organochlorine insecticides were determined in several types of membrane. Insecticide partitioning varied among the membranes under study, depending on temperature, cholesterol content and on the physico-chemical profiles of membrane components and the insecticides themselves. The maximal partitions for DDT, lindane, parathion and malathion in egg phosphatidylcholine bilayers over the temperature range from 10 to 37°C (at which the lipid is in the liquid-crystalline state) were about 260000, 2000, 1000 and 120, respectively. Incorporation of 50 mol% cholesterol in egg phosphatidylcholine bilayers dramatically decreased the partition and almost abolished the temperature effect. First-order phase transitions of dimyristoyl-, dipalmitoyl- and distearoylphosphatidylcholines (DMPC, DPPC and DSPC) were accompanied by a sharp increase in insecticide partition. Furthermore, the insecticides under study were more easily accommodated in bilayers of short-aliphatic-chain lipids, since higher values of partition were obtained in DMPC bilayers. Partition values in native membranes depended considerably on the membrane type and composition and were higher in sarcoplasmic reticulum (SR) and mitochondria than in brain microsomes, myelin and erythrocytes. Identical results were obtained in related liposomes of total extracted lipids, although the absolute partitions showed decreased values. In general, the incorporation of insecticides correlated reasonably with the cholesterol content of the membranes. The order of partitioning of the above insecticides did not run parallel with their toxicity to mammals and, both in model and in native membranes, followed the sequence: DDT ? lindane > parathion > malathion.  相似文献   

Differentiation between canine cutaneous and visceral leishmaniasis by the detection of immunoglobulin G specific for Leishmania (Viannia) braziliensis and Leishmania (Leishmania) chagasi antigens using flow cytometry     

Santiago Mde A  Ribeiro FC  Mouta-Confort E  Nascimento LD  Schubach Ade O  Madeira Mde F  Bertho AL 《Veterinary parasitology》2008,154(3-4):341-346

Flow cytometry employing Leishmania (L.) chagasi (Lc) and L. (Viannia) braziliensis (Lb) antigen was used to establish the differential diagnosis between visceral (VL) and cutaneous leishmaniasis (CL) in dogs. Flow cytometry permitted the detection of Leishmania-specific immunoglobulin G in sera from 19 dogs: nine with CL and 10 with VL. A significant difference in the percentage of positive staining was observed in sera from dogs with CL between the homologous antigen (69% for Lb) and the heterologous antigen (42% for Lc). However, this difference was not significant in sera from dogs with VL (61% for Lb and 73% for Lc). No significant staining was observed in control sera (0.6% for Lb and 0.4% for Lc) consisting of samples from healthy dogs, or in the group with sporotrichosis (1.8% for Lb and 1.5% for Lc), a differential diagnosis of CL. The results suggest that flow cytometry might be useful for the differentiation between CL and VL in dogs, with practical applications in areas where the two infections overlap.  相似文献