Behavior of Leishmania braziliensis s.l. in Golden Hamsters: Evolution of the Infection under Different Experimental Conditions

1988 ◽  
Vol 74 (6) ◽  
pp. 1059 ◽  
Author(s):  
Bruno Travi ◽  
Jose Rey-Ladino ◽  
Nancy G. Saravia
Keyword(s):  
Leishmania Braziliensis ◽  
Experimental Conditions ◽  
Golden Hamsters

Failure of N-(2,4-dinitrophenyl)-5-methoxytryptamine (a putative melatonin antagonist) and of N-(3,5-dinitrophenyl)-5-methoxytryptamine to prevent the effects of injections of melatonin in the late afternoon on testicular activity of the golden hamster

1989 ◽  
Vol 123 (2) ◽  
pp. 243-247 ◽  
Author(s):  
P. Pévet ◽  
M. Masson-Pévet ◽  
J. Chantegrel ◽  
A. Marsura ◽  
C. Luu-Duc ◽  
...  
Keyword(s):  
Ambient Temperature ◽  
Golden Hamster ◽  
Experimental Conditions ◽  
Late Afternoon ◽  
Golden Hamsters ◽  
Gonadal Atrophy ◽  
Male Golden Hamsters ◽  
Long Photoperiod ◽  
Low Ambient Temperature

ABSTRACT Daily injections of 10 μg melatonin in the late afternoon into male golden hamsters kept under a long photoperiod (14 h light: 10 h darkness) and at low ambient temperature 6 ± 1 °C) induced a complete gonadal atrophy after 4 weeks. When administered under the same conditions at doses of 25 μg, neither N-(3,5-dinitrophenyl)-5-methoxytryptamine or N-(2,4-dinitrophenyl)-5-methoxytryptamine, a putative melatonin antagonist termed ML-23 in the literature, showed any effect on testicular activity. Moreover, these two drugs were also unable to prevent melatonin-induced gonadal atrophy when injected 30 min before melatonin. The results demonstrate that in the golden hamster and in the present experimental conditions, these drugs do not have the melatonin-antagonistic properties as described in the rat. Journal of Endocrinology (1989) 123, 243–247

Leishmania braziliensis: Dissemination of panamanian strains in golden hamsters

1979 ◽  
Vol 48 (3) ◽  
pp. 359-363 ◽  
Author(s):  
Aristides Herrer ◽  
Sam R. Telford ◽  
Howard A. Christensen
Keyword(s):  
Leishmania Braziliensis ◽  
Golden Hamsters

scholarly journals EXPANSION OF CYTOGENETICALLY MODIFIED FORM OF OPISTHORCHIS FELINEUS IN THE TOM RIVER BASIN

2016 ◽  
pp. 65-69
Author(s):  
Nikolai Ilyinskikh ◽  
Nikolai Ilyinskikh ◽  
Ekaterina Ilyinskikh ◽  
Ekaterina Ilyinskikh
Keyword(s):  
River Basin ◽  
Industrial Wastewater ◽  
Robertsonian Fusion ◽  
Experimental Conditions ◽  
Opisthorchis Felineus ◽  
Chromosome Form ◽  
Golden Hamsters ◽  
Siberian Chemical ◽  
Chromosome Karyotype

In 1993, karyotyping of Opisthorchis felineus sporocysts, isolated from aquatic mollusks Bithynia inflat a in the industrial wastewater of the Siberian Chemical Combine discovered cytogenetically modified 12-chromosome specimens. In 2012-2013, a repeated study of the spread of these mutant trematodes in the lower course of the river Tom was carried out. It was established that specimens with sporocysts of O. felineus having 2n=12 were found in 8 of 10 places of catching. The caught goldfish were used to isolate metacercariae to infest golden hamsters in the experimental conditions. After 5 months, the hamster livers were processed to extract marita specimens and the number of chromosomes in their ovaries and testes was cytogenetically determined. The results of analysis of the spread of O. felineus carried out by this method showed the presence of 12-chromosome form of the Opisthorchis marita in all places of fishing out in the lower course of the river Tom. Analysis of the 12-chromosome karyotype allows to conclude that this mutation was a result of Robertsonian fusion of chromosomes 3 and 6 of 14-chromosome form of karyotype.

The effect of 5-methoxytryptamine on golden hamster gonads is not a consequence of its acetylation into melatonin

1989 ◽  
Vol 121 (3) ◽  
pp. 507-512 ◽  
Author(s):  
F. Raynaud ◽  
J. L. Miguel ◽  
B. Vivien-Roels ◽  
M. Masson-Pévet ◽  
P. Pévet
Keyword(s):  
High Performance ◽  
Physiological Activity ◽  
Plasma Concentrations ◽  
Experimental Conditions ◽  
Late Afternoon ◽  
Golden Hamsters ◽  
Gonadal Atrophy ◽  
Testicular Regression ◽  
Long Photoperiod ◽  
Partial Atrophy

ABSTRACT Radioimmunoassay and high performance liquid chromatography were used to determine if the gonadal atrophy induced by late afternoon injections of 5-methoxytryptamine (5-MT) in golden hamsters kept under long photoperiod could be due to the acetylation of this compound into melatonin. An increase in plasma concentrations of melatonin (10–13 nmol/l) was detected 15 min after injection of 130 nmol 5-MT. An injection of 4·3 nmol melatonin generated a similar plasma concentration of melatonin. 5-MT (130 nmol) and melatonin (4·3 nmol) were then injected daily in the late afternoon to golden hamsters kept under long photoperiod. After 8 weeks, 5-MT induced total testicular regression, while melatonin induced partial atrophy only. Thus under these experimental conditions, 5-MT had a physiological activity independent of that of melatonin. Journal of Endocrinology (1989) 121, 507–512

Electrolytic Isolation of Twin-Type Shock Deformation Structures

1967 ◽  
Vol 25 ◽  
pp. 318-319
Author(s):  
F. I. Grace ◽  
L. E. Murr
Keyword(s):  
Grain Boundaries ◽  
Thin Foil ◽  
Electrolyte Composition ◽  
Experimental Conditions ◽  
Average Current Density ◽  
Electron Transmission ◽  
Deformation Structures ◽  
The Matrix ◽  
Average Current ◽  
Specimen Edge

During the course of electron transmission investigations of the deformation structures associated with shock-loaded thin foil specimens of 70/30 brass, it was observed that in a number of instances preferential etching occurred along grain boundaries; and that the degree of etching appeared to depend upon the various experimental conditions prevailing during electropolishing. These included the electrolyte composition, the average current density, and the temperature in the vicinity of the specimen. In the specific case of 70/30 brass shock-loaded at pressures in the range 200-400 kilobars, the predominant mode of deformation was observed to be twin-type faults which in several cases exhibited preferential etching similar to that observed along grain boundaries. A novel feature of this particular phenomenon was that in certain cases, especially for twins located in the vicinity of the specimen edge, the etching or preferential electropolishing literally isolated these structures from the matrix.

Site of Lysosome Production During Hepatic Injury

1969 ◽  
Vol 27 ◽  
pp. 348-349
Author(s):  
Nalin J. Unakar
Keyword(s):  
Electron Microscopy ◽  
Golgi Apparatus ◽  
Mouse Liver ◽  
Hepatic Injury ◽  
Close Approximation ◽  
Experimental Conditions ◽  
Toxic Injury

The increased number of lysosomes as well as the close approximation of lysosomes to the Golgi apparatus in tissue under variety of experimental conditions is commonly observed. These observations suggest Golgi involvement in lysosomal production. The role of the Golgi apparatus in the production of lysosomes in mouse liver was studied by electron microscopy of liver following toxic injury by CCI4.

Optimizing conditions for x-ray microchemical analysis in analytical electron microscopy

1978 ◽  
Vol 36 (1) ◽  
pp. 548-549 ◽  
Author(s):  
N. J. Zaluzec
Keyword(s):  
Solid Angle ◽  
Analytical Electron Microscopy ◽  
Incident Beam ◽  
Thin Foil ◽  
Experimental Conditions ◽  
X Ray ◽  
Microchemical Analysis ◽  
Analytical Electron ◽  
Image Position ◽  
Incident Beam Energy

The ultimate sensitivity of microchemical analysis using x-ray emission rests in selecting those experimental conditions which will maximize the measured peak-to-background (P/B) ratio. This paper presents the results of calculations aimed at determining the influence of incident beam energy, detector/specimen geometry and specimen composition on the P/B ratio for ideally thin samples (i.e., the effects of scattering and absorption are considered negligible). As such it is assumed that the complications resulting from system peaks, bremsstrahlung fluorescence, electron tails and specimen contamination have been eliminated and that one needs only to consider the physics of the generation/emission process.The number of characteristic x-ray photons (Ip) emitted from a thin foil of thickness dt into the solid angle dΩ is given by the well-known equation

SEM analysis of the change in the reaction rates with deposit structures in the copper-iron cementation system

1978 ◽  
Vol 36 (1) ◽  
pp. 456-457
Author(s):  
V. Annamalai ◽  
L.E. Murr
Keyword(s):  
Structural Characteristics ◽  
Secondary Electron Emission ◽  
Copper Deposit ◽  
Reaction Rates ◽  
Sem Analysis ◽  
Experimental Conditions ◽  
Major Drawback ◽  
Emission Mode ◽  
Scrap Iron ◽  
Image Position

Economical recovery of copper metal from leach liquors has been carried out by the simple process of cementing copper onto a suitable substrate metal, such as scrap-iron, since the 16th century. The process has, however, a major drawback of consuming more iron than stoichiometrically needed by the reaction.Therefore, many research groups started looking into the process more closely. Though it is accepted that the structural characteristics of the resultant copper deposit cause changes in reaction rates for various experimental conditions, not many systems have been systematically investigated. This paper examines the deposit structures and the kinetic data, and explains the correlations between them.A simple cementation cell along with rotating discs of pure iron (99.9%) were employed in this study to obtain the kinetic results The resultant copper deposits were studied in a Hitachi Perkin-Elmer HHS-2R scanning electron microscope operated at 25kV in the secondary electron emission mode.

Relative Intensities in ED Patterns From Thin Gold Films

1972 ◽  
Vol 30 ◽  
pp. 636-637
Author(s):  
R. H. Morriss ◽  
J. D. C. Peng ◽  
C. D. Melvin
Keyword(s):  
Theoretical Calculations ◽  
Diffraction Theory ◽  
Gold Films ◽  
Reasonable Accuracy ◽  
Experimental Conditions ◽  
Crystal Perfection ◽  
Heavy Atoms ◽  
Fine Focus ◽  
Convergent Beam ◽  
Beam Diffraction

Although dynamical diffraction theory was modified for electrons by Bethe in 1928, relatively few calculations have been carried out because of computational difficulties. Even fewer attempts have been made to correlate experimental data with theoretical calculations. The experimental conditions are indeed stringent - not only is a knowledge of crystal perfection, morphology, and orientation necessary, but other factors such as specimen contamination are important and must be carefully controlled. The experimental method of fine-focus convergent-beam electron diffraction has been successfully applied by Goodman and Lehmpfuhl to single crystals of MgO containing light atoms and more recently by Lynch to single crystalline (111) gold films which contain heavy atoms. In both experiments intensity distributions were calculated using the multislice method of n-beam diffraction theory. In order to obtain reasonable accuracy Lynch found it necessary to include 139 beams in the calculations for gold with all but 43 corresponding to beams out of the [111] zone.

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