Field and experimental studies on Dicrocoelium dendriticum and dicrocoeliasis in northern Spain

2005 ◽  
Vol 79 (4) ◽  
pp. 291-302 ◽  
Author(s):  
M.Y. Manga-González ◽  
C. González-Lanza
Keyword(s):  
Random Amplified Polymorphic Dna ◽  
Experimental Studies ◽  
Parasite Burden ◽  
Gamma Glutamyl Transpeptidase ◽  
Northern Spain ◽  
Igg Antibody ◽  
Experimental Conditions ◽  
North West ◽  
Dicrocoelium Dendriticum ◽  
Enzymatic Systems

AbstractThe transmission, control and the relationship between Dicrocoelium dendriticum and its definitive (sheep and cattle) and intermediate (molluscs and ants) hosts under natural and experimental conditions are described. Eleven species of molluscs and four of ants were found infected with larval D. dendriticum in León province, north-west Spain. Infected ants were observed between April and November and in tetania at 7.5–26.9°C. The highest shedding of eggs by sheep and cattle was detected in winter. Two treatments applied in November and January were the most effective. In experimentally infected molluscs, the parasite was not visible under the stereomicroscope, at least until 50 days post-infection (p.i.). The prepatent period in experimentally infected lambs was 49–79 days p.i. The number of eggs per gram increased with the days p.i. and the parasite burden. The aspartate aminotransferase, alanine aminotransferase, gamma-glutamyl transpeptidase, leukocyte and neutrophil values of infected lambs increased, but those of lymphocytes decreased. Using the enzyme-linked immunosorbert assay technique, the IgG antibody response to excretory–secretory and somatic antigens of D. dendriticum was positive from day 30 p.i., although the maximum antibody levels were observed on day 60 p.i. The number of worms per lamb ranged between 30 and 2063. Cholangitis and cholangiectasia of the septal bile and hepatic ducts were observed. The best enzymatic systems for adult and larval D. dendriticum characterization were lactate dehydrogenase, glucose phosphate isomerase and phosphoglucomutase. Genetic variability of adult D. dendriticum was high using the random amplified polymorphic DNA technique.

scholarly journals Upregulated Expression of Cytotoxicity-Related Genes in IFN-γKnockout Mice withSchistosoma japonicumInfection

2011 ◽  
Vol 2011 ◽  
pp. 1-13 ◽  
Author(s):  
Xiaotang Du ◽  
Jingjiao Wu ◽  
Meijuan Zhang ◽  
Yanan Gao ◽  
Donghui Zhang ◽  
...  
Keyword(s):  
T Cells ◽  
Immune Responses ◽  
Schistosoma Japonicum ◽  
Fas Ligand ◽  
Acute Infection ◽  
Acquired Resistance ◽  
Parasite Burden ◽  
Cytotoxic T Cell ◽  
Igg Antibody

It is well accepted that IFN-γis important to the development of acquired resistance against murine schistosomiasis. However, thein vivorole of this immunoregulatory cytokine in helminth infection needs to be further investigated. In this study, parasite burden and host immune response were observed in IFN-γknockout mice (IFNg KO) infected withSchistosoma japonicumfor 6 weeks. The results suggested that deficiency in IFN-γled to decreased egg burden in mice, with low schistosome-specific IgG antibody response and enhanced activation of T cells during acute infection. Microarray and qRT-PCR data analyses showed significant upregulation of some cytotoxicity-related genes, including those from the granzyme family, tumor necrosis factor, Fas Ligand, and chemokines, in the spleen cells of IFNg KO mice. Furthermore, CD8+cells instead of NK cells of IFNg KO mice exhibited increased transcription of cytotoxic genes compared with WT mice. Additionally,Schistosoma japonicum-specific egg antigen immunization also could activate CD8+T cells to upregulate the expression of cytotoxic genes in IFNg KO mice. Our data suggest that IFN-γis not always a positive regulator of immune responses. In certain situations, the disruption of IFN-γsignaling may up-regulate the cytotoxic T-cell-mediated immune responses to the parasite.

scholarly journals Gender Is a Major Determinant of the Clinical Evolution and Immune Response in Hamsters Infected with Leishmania spp.

2002 ◽  
Vol 70 (5) ◽  
pp. 2288-2296 ◽  
Author(s):  
Bruno L. Travi ◽  
Yaneth Osorio ◽  
Peter C. Melby ◽  
Bysani Chandrasekar ◽  
Lourdes Arteaga ◽  
...  
Keyword(s):  
Immune Response ◽  
Transforming Growth Factor ◽  
Experimental Studies ◽  
Parasite Burden ◽  
Transforming Growth Factor Β ◽  
Lesion Size ◽  
Interleukin 4 ◽  
Cutaneous Lesions ◽  
Disease Evolution ◽  
Leishmania Spp

ABSTRACT In regions where leishmaniasis is endemic, clinical disease is usually reported more frequently among males than females. This difference could be due to disparate risks of exposure of males and females, but gender-related differences in the host response to infection may also play a role. Experimental studies of the influence of gender on Leishmania infection have not included parasites of the subgenus Viannia, which is the most common cause of cutaneous leishmaniasis in the Americas. Mice are not readily susceptible to infection by Leishmania (Viannia) spp., but cutaneous infection of hamsters with L. (V.) panamensis or L. (V.) guyanensis resulted in chronic lesions typical of the human disease caused by these parasites. Strikingly, infection of male hamsters resulted in significantly greater lesion size and severity, an increased rate of dissemination to distant cutaneous sites, and a greater parasite burden in the draining lymph node than infection in female animals. Two lines of evidence indicated this gender-related difference in disease evolution was determined at least in part by the sex hormone status of the animal. First, prepubertal male animals had smaller and/or less severe cutaneous lesions than adult male animals. Second, infection of testosterone-treated female animals resulted in significantly larger lesions than in untreated female animals. The increased severity of disease in male compared to female animals was associated with significantly greater intralesional expression of interleukin-4 (IL-4) (P = 0.04), IL-10 (P = 0.04), and transforming growth factor β (TGF-β) (P < 0.001), cytokines known to promote disease in experimental leishmaniasis. There was a direct correlation between the expression of TGF-β mRNA and lesion size (Spearman's correlation coefficient = 0.873; P < 0.001). These findings demonstrate an inherent risk of increased disease severity in male animals, which is associated with a more permissive immune response.

scholarly journals Mechanism of the process of decomposition of apatitis with phosphoric acid

2019 ◽  
Vol 81 (1) ◽  
pp. 294-297
Author(s):  
R. F. Sabirov ◽  
A. F. Makhotkin ◽  
Yu. N. Sakharov ◽  
I. A. Makhotkin ◽  
I. Yu. Sakharov
Keyword(s):  
Phosphoric Acid ◽  
Ph Value ◽  
Batch Reactor ◽  
Experimental Studies ◽  
Hydrogen Ions ◽  
Experimental Conditions ◽  
Monocalcium Phosphate ◽  
Ph Values ◽  
Whole Process ◽  
Proportional Increase

Experimental studies of the kinetics and mechanism of the process, decomposition of apatite by phosphoric acid, in the Apatite-H3PO4-H2O system without the addition of sulfuric acid have been performed. The study of the decomposition process of Kovdorsky apatite with certain particle sizes was carried out in a batch reactor with a volume of 1 dm3 with stirring of the reaction mixture, and an initial concentration of phosphoric acid of 17% by weight, at a temperature of 78–82 °C. Observation of the process was carried out by determining the concentration of phosphoric acid and the concentration of monocalcium phosphate. The acidity of the reaction mixture was determined by the pH meter readings (pH-105 MA with a glass combined-ESC-10603 electrode). It was shown that during the whole process a constant smooth increase in the pH value of the reaction mixture to pH 6 occurs. Comparison of the pH values of the reaction mixture during the actual at the time of determining the concentration of phosphoric acid and pH of phosphoric acid of the corresponding concentration in the aqueous solution shows that the pH value of the reaction mixture is significantly affected by the presence of monocalcium phosphate gel. During the process, during the first thirty minutes, the concentration of phosphoric acid decreases from 17 to 10% by weight, the corresponding quantitative formation of monocalcium phosphate gel and a proportional increase in the pH of the reaction mixture. Then, as the concentration of phosphoric acid decreases, the process slows down and does not proceed to the end under the experimental conditions. The dependence of the concentration of hydrogen ions in the reaction mixture on the time of the process of decomposition of apatite in phosphoric acid, which is presented in logarithmic coordinates, shows that the mechanism of formation of hydrogen ions during the whole process does not change. Thus, it is shown that the process of decomposition of apatite by phosphoric acid in the Apatite-H3PO4-H2O system proceeds with the formation of an intermediate product - monocalcium phosphate gel. When this occurs, a corresponding significant change in the pH values of the reaction mixture occurs. During the whole process there is a constant decrease in the concentration of phosphoric acid.

scholarly journals ADSORPTION OF PHOSPHATE IONS ON RED SLUDGE

2017 ◽  
Vol 60 (8) ◽  
pp. 80
Author(s):  
Svetlana M. Kramer ◽  
Mariya V. Terekhova ◽  
Inna V. Artamonova
Keyword(s):  
Hydrochloric Acid ◽  
Experimental Studies ◽  
Aluminum Production ◽  
Quantitative Composition ◽  
Experimental Conditions ◽  
Initial Concentration ◽  
Phosphate Ions ◽  
Frumkin’S Isotherm ◽  
Ph Range ◽  
Red Sludge

In work the possibility of red sludge (waste of aluminum production by Bayer's method) to adsorb phosphate ions from water solutions at various concentration of ions and in the pH range from 3 to 10 is studied. Relevance of use of red sludge for receiving on its basis of sorbents is reasoned. For identification of the studied object the qualitative and quantitative composition of red sludge was established by the method of the X-ray phase analysis. The technique of red slage activation by hydrochloric acid, and also an adsorption technique of phosphate ions on the red sludge surface is described. Experimental studies of adsorption of phosphate ions on the surface of the red slage activated by hydrochloric acid depending on рН and concentration of initial solution were conducted. The dependence of adsorption phosphate ions on the red slage activated by НСl on рН and on the initial concentration of phosphate ions in solution is presented. These dependences of a relative fraction of distribution of various ions of phosphoric acid on рН are given in work. The form of ion phosphate having the greatest adsorptive activity on the red slage activated by hydrochloric acid in experimental conditions is revealed. Experimental data on dependence of adsorption of phosphate ions on their initial concentration in solution are described by Frumkin's isotherm. The constant of the adsorptive balance, limit adsorption, the parameter of intermolecular interaction of the adsorbed particles are calculated. Optimum conditions for adsorption of phosphate ions on red slage are established.Forcitation:Kramer S.M., Terekhova M.V., Artamonova I.V. Adsorption of phosphate ions on red sludge. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2017. V. 60. N 8. P. 80-83.

Experiments in social science

2018 ◽  
Author(s):  
John A. Hughes
Keyword(s):  
Social Psychology ◽  
Experimental Design ◽  
Social Science ◽  
Social Research ◽  
Experimental Studies ◽  
Natural Sciences ◽  
Hawthorne Effect ◽  
Experimental Conditions ◽  
Control Factors ◽  
The Social

Within social science the experiment has an ambiguous place. With the possible exception of social psychology, there are few examples of strictly experimental studies. The classic study still often cited is the Hawthorne experiments, which began in 1927, and is used mainly to illustrate what became known as the ‘Hawthorne Effect’, that is, the unintended influence of the research itself on the results of the study. Yet, experimental design is often taken within social research as the embodiment of the scientific method which, if the social sciences are to reach the maturity of the natural sciences, social research should seek to emulate. Meeting this challenge meant trying to devise ways of applying the logic of the experiment to ‘non-experimental’ situations where it was not possible directly to manipulate the experimental conditions. Criticisms have come from two main sources: first, from researchers who claim that the techniques used to control factors within non-experimental situations are unrealizable with current statistical methods and, second, those who reject the very idea of hypothesis-testing as an ambition for social research.

Experimental Studies of the Mental Speed of Schizophrenics

1958 ◽  
Vol 104 (437) ◽  
pp. 1123-1129 ◽  
Author(s):  
Anne Broadhurst
Keyword(s):  
Reaction Time ◽  
Problem Solving ◽  
Motor Performance ◽  
Psychiatric Patients ◽  
Experimental Studies ◽  
Thought Processes ◽  
Mental Functioning ◽  
Experimental Conditions ◽  
Experimental Control ◽  
Schizophrenic Patients

It has been clinically observed that psychiatric patients in general (6, 11) and schizophrenic patients in particular (1, 4) show abnormalities of mental speed, being “retarded” or slower than normals on many measures. Confirmatory evidence on this point is to be found but much of the early work on speed of schizophrenic reactivity used measures of speed of motor performance (12, 13) or of reaction time under various conditions (6), ignoring more fundamental slowness of thought processes. The present studies are concentrated on the recent finding that schizophrenics show abnormally slow mental speed measured in a problem-solving situation (4, 18, 19). The aim of the investigation was to discover the exact conditions under which this abnormality appears, and, thence, by manipulating the experimental conditions, to be able to bring speed of mental functioning under experimental control. This paper describes the attempt to bring speed under control by means of drugs. A second paper (2) deals with the effect of practice upon mental speed.

IgG antibody response to ES or somatic antigens of Dicrocoelium dendriticum (Trematoda) in experimentally infected sheep

2000 ◽  
Vol 86 (6) ◽  
pp. 472-479 ◽  
Author(s):  
C. González-Lanza ◽  
M. Y. Manga-González ◽  
R. Campo ◽  
P. Del-Pozo ◽  
H. Sandoval ◽  
...  
Keyword(s):  
Antibody Response ◽  
Infected Sheep ◽  
Igg Antibody ◽  
Dicrocoelium Dendriticum ◽  
Somatic Antigens

Induction Motor Multi-Fault Analysis Based on Intrinsic Mode Functions in Hilbert-Huang Transform

2009 ◽  
Author(s):  
Xin Xue ◽  
V. Sundararajan
Keyword(s):  
Induction Motor ◽  
Experimental Studies ◽  
Current Data ◽  
Fault Analysis ◽  
Vibration Sensor ◽  
Intrinsic Mode Functions ◽  
Experimental Conditions ◽  
Classification Rate ◽  
Multiple Faults ◽  
Hilbert Huang Transform

This paper reports experimental studies to detect two faults in a 3-phase 1.5hp induction motor using intrinsic mode functions from Hilbert-Huang transform. The faults studied are the eccentricity of the air-gap between the rotor and stator and damage to the outer race of bearings. The experiments are conducted under four conditions: the normal no-fault condition, two single fault conditions and the multiple faults condition. Two microphones, one vibration sensor and one current sensor are used to collect sound, vibration and current data respectively. The data is analyzed using the Hilbert-Huang transform and Fast Fourier Transform. Features are extracted from the spectrum of intrinsic mode functions and the average value of their envelope. Three simple classifiers are used to classify these four experimental conditions. The results demonstrate that the multiple sensors do improve the classification rate and that the Intrinsic Mode Functions obtained by the Hilbert-Huang transform are more effective than FFT in classifying multiple faults.

Etude du métabolisme du 3-propyl-éther de l'estradiol 17β comparativement à l'estradiol 17β dans le foie de rat perfusé

1978 ◽  
Vol 56 (10) ◽  
pp. 985-992 ◽  
Author(s):  
Jean-Pierre Tresca ◽  
Geneviève Ponsard ◽  
Hervé Degrelle ◽  
Max-Fernand Jayle
Keyword(s):  
Rat Liver ◽  
Liver Perfusion ◽  
Ether Group ◽  
Experimental Conditions ◽  
Active Uptake ◽  
Rat Liver Perfusion ◽  
Constant Rate ◽  
Enzymatic Systems

The metabolism of 6,7-3H-tabelled 3-propyl ether estradiol (PE2) and of [6,7-3H]estradiol was studied by rat liver perfusion under different experimental conditions. In all cases, 90% of the radioactivity was retained in the liver, indicating an active uptake by the liver. The hepatic radioactivity was slowly released at a constant rate in the efferent perfusate. The proportion of radioactive metabolites in the perfusate was approximately the same as in the liver.3-Propyl ether estrone (PE1), a dehydrogenation product of PE2, and 3-propyl ether estriol (PE3), a 16α-hydroxylated derivative of PE2, were identified. Propylated metabolites more polar than PE2 were found. A low amount of propylated metabolites was conjugated with the exception of PE1. From the appearance of phenolic steroids including estrone, estradiol, and estriol, it was concluded that cleavage of the 3-propyl ether group had occurred.Compared with perfusion under oxygen, the overall metabolism was significantly reduced when the perfusion was carried out under nitrogen which demonstrates that oxygen plays a part in all the enzymatic systems involved. When animals were stimulated by phenobarbital, their entire metabolism was activated. These results suggest a metabolism mainly located in the hepatic microsomes.Our results show that the propylated hormone is metabolized like the free hormone. However, the transformations of PE2 are slower when compared with estradiol: thus, the 3-propyl ether group provided some hormone protection against hepatic degradation.

Experimental investigation of dynamo effect in the secondary pumps of the fast breeder reactor Superphenix

2000 ◽  
Vol 403 ◽  
pp. 263-276 ◽  
Author(s):  
A. ALEMANY ◽  
Ph. MARTY ◽  
F. PLUNIAN ◽  
J. SOTO
Keyword(s):  
Magnetic Field ◽  
Large Scale ◽  
Magnetic Energy ◽  
Experimental Studies ◽  
Phenomenological Approach ◽  
Magnetic Reynolds Number ◽  
Experimental Investigations ◽  
Dynamo Action ◽  
Experimental Conditions ◽  
Dynamo Effect

The fast breeder reactors (FBR) BN600 (Russia) and Phenix (France) have been the subject of several experimental studies aimed at the observation of dynamo action. Though no dynamo effect has been identified, the possibility was raised for the FBR Superphenix (France) which has an electric power twice that of BN600 and five times larger than Phenix. We present the results of a series of experimental investigations on the secondary pumps of Superphenix. The helical sodium flow inside one pump corresponds to a maximum magnetic Reynolds number (Rm) of 25 in the experimental conditions (low temperature). The magnetic field was recorded in the vicinity of the pumps and no dynamo action has been identified. An estimate of the critical flow rate necessary to reach dynamo action has been found, showing that the pumps are far from producing dynamo action. The magnetic energy spectrum was also recorded and analysed. It is of the form k−11/3, suggesting the existence of a large-scale magnetic field. Following Moffatt (1978), this spectrum slope is also justified by a phenomenological approach.

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