The Experts below are selected from a list of 432 Experts worldwide ranked by ideXlab platform
Wilhelm Foissner - One of the best experts on this subject based on the ideXlab platform.
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an update of basic light and scanning electron microscopic methods for taxonomic studies of ciliated protozoa
International Journal of Systematic and Evolutionary Microbiology, 2014Co-Authors: Wilhelm FoissnerAbstract:This is an update of the review by Foissner (1991). Since then, I have improved some methods considerably. The following methods are described in detail: live observation, Supravital Staining with methyl green-pyronin, dry silver nitrate impregnation, wet silver nitrate impregnation, silver carbonate impregnation, protargol impregnation (three procedures), scanning electron microscopy, and deciliation. Familiarity with these methods (or modifications) is a prerequisite for successful taxonomic work. No Staining method is equally appropriate to all kinds of ciliates. A table is provided which indicates those procedures which work best for certain groups of ciliates. A second table relates to the structures revealed by the procedures. Good descriptions usually demand at least live observation, silver nitrate and protargol or silver carbonate impregnation. Some instructions are provided for distinguishing mono- and dikinetids as well as ciliated and non-ciliated basal bodies in silvered ciliates. Furthermore, I added a section on ‘Deposition and Labeling of Preparations’. All methods work not only with ciliates but also with many other heterotrophic and autotrophic flagellated and amoeboid protists. The brilliancy of silver preparations has tempted some taxonomists to neglect live observation. However, many important species characteristics cannot be seen or are changed in silvered specimens. I thus consider all species descriptions based exclusively on silver slides as incomplete and of doubtful value for both α-taxonomists and ecologists.
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basic light and scanning electron microscopic methods for taxonomic studies of ciliated protozoa
European Journal of Protistology, 1991Co-Authors: Wilhelm FoissnerAbstract:Summary The following methods for taxonomic studies of ciliated protozoa are described in detail: live observation, Supravital Staining with methyl green-pyronin, dry silver nitrate impregnation, wet silver nitrate impregnation, silver carbonate impregnation, protargol impregnation (three procedures), and scanning electron microscopy. Familiarity with these methods (or modifications) is an absolute prerequisite for successful taxonomic work. No Staining method is equally appropriate to all kinds of ciliates. A table is provided which indicates those procedures which work best for certain groups of ciliates. A second table relates to the structures revealed by the procedures. Good descriptions usually demand at least live observation, silver nitrate and protargol or silver carbonate impregnation. Some instructions are provided for distinguishing mono- and dikinetids as well as ciliated and non-ciliated basal bodies in silvered ciliates. The brilliancy of the silver preparations has unfortunately recently tempted some taxonomists to neglect live observation. However, many important species characters cannot be seen or are changed in silvered specimens. I thus consider all species descriptions based exclusively on silver slides as incomplete and of doubtful value for both α-taxonomists and ecologists. Especially the latter are usually not trained to correlate the silvered structures with the live appearance of the cell.
Habib Ur Rehman - One of the best experts on this subject based on the ideXlab platform.
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butylated hydroxytoluene inclusion in semen extender improves the post thawed semen quality of nili ravi buffalo bubalus bubalis
Theriogenology, 2009Co-Authors: A Ijaz, A Hussain, M Aleem, M S Yousaf, Habib Ur RehmanAbstract:The study was carried out to evaluate the potential impact of butylated hydroxytoluene (BHT) on the frozen-thawed semen quality of Nili-Ravi buffalo bulls. Ejaculated bull semen was extended in a Tris-citrate egg yolk extender containing various concentrations of BHT (0.5, 1.0, 2.0 and 3.0mM). Semen was frozen at -196 degrees C using 50 x 10(6) spermatozoa per 0.5 mL straws. Five straws from each treatment were thawed to assess the semen quality in terms of sperm motility, viability, plasma membrane integrity and acrosomal integrity. Post-thawed sperm motility was determined using a phase-contrast microscope. Viability, plasma membrane integrity and acrosomal integrity were evaluated by the Supravital Staining, hypo-osmotic swelling test and normal acrosomal reaction, respectively. The highest (P<0.05) motility, acrosomal integrity and hypo-osmotic swelling response of spermatozoa was achieved by addition of 1.0 and 2.0mM BHT to semen extender. However, highest (P<0.05) viability of spermatozoa was achieved by inclusion of 2.0mM BHT. The higher concentration of BHT (3.0mM) reduced the motility, acrosomal integrity, viability and hypo-osmotic swelling response of the spermatozoa compared to other concentration used. In conclusion, BHT when added in the semen extender can improve the semen quality of buffalo bulls.
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butylated hydroxytoluene inclusion in semen extender improves the post thawed semen quality of nili ravi buffalo bubalus bubalis
Theriogenology, 2009Co-Authors: A Ijaz, A Hussain, M Aleem, M S Yousaf, Habib Ur RehmanAbstract:Abstract The study was carried out to evaluate the potential impact of butylated hydroxytoluene (BHT) on the frozen–thawed semen quality of Nili-Ravi buffalo bulls. Ejaculated bull semen was extended in a Tris–citrate egg yolk extender containing various concentrations of BHT (0.5, 1.0, 2.0 and 3.0mM). Semen was frozen at −196°C using 50×10 6 spermatozoa per 0.5mL straws. Five straws from each treatment were thawed to assess the semen quality in terms of sperm motility, viability, plasma membrane integrity and acrosomal integrity. Post-thawed sperm motility was determined using a phase-contrast microscope. Viability, plasma membrane integrity and acrosomal integrity were evaluated by the Supravital Staining, hypo-osmotic swelling test and normal acrosomal reaction, respectively. The highest ( P P
Makoto Hayashi - One of the best experts on this subject based on the ideXlab platform.
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an automated new technique for scoring the rodent micronucleus assay computerized image analysis of acridine orange Supravitally stained peripheral blood cells
Mutation Research, 1998Co-Authors: Norihide Asano, Yoshiyuki Katsuma, Hironobu Tamura, Naohiko Higashikuni, Makoto HayashiAbstract:Abstract We developed an automated image analysis system to obtain objective data for the rodent peripheral blood micronucleus assay with acridine orange (AO) Supravital Staining. The system was able to identify micronucleated reticulocytes (MNRETs) and to evaluate inhibition of bone marrow cell proliferation by measuring the reticular area of reticulocytes (RETs). We also developed automated equipment to produce homogeneous acridine orange-coated glass slides. This study was designed to compare automated scoring with manual scoring using 4 model clastogens and 2 mouse strains. The MNRET incidence induced by each clastogen was similar for automated and manual scoring and there was good correlation ( r =0.92) between the methods. In addition, an index of bone marrow toxicity based on the reticular area of RETs was compared to the conventional index (% of polychromatic erythrocytes (PCE) to total erythrocytes; PCE ratio) and was similar. The results indicated that our technique for computer-assisted image analysis for the micronucleus assay with AO Supravitally stained peripheral blood RETs was comparable to conventional microscopic scoring, and it was superior in objectivity and statistical power.
A Ijaz - One of the best experts on this subject based on the ideXlab platform.
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butylated hydroxytoluene inclusion in semen extender improves the post thawed semen quality of nili ravi buffalo bubalus bubalis
Theriogenology, 2009Co-Authors: A Ijaz, A Hussain, M Aleem, M S Yousaf, Habib Ur RehmanAbstract:The study was carried out to evaluate the potential impact of butylated hydroxytoluene (BHT) on the frozen-thawed semen quality of Nili-Ravi buffalo bulls. Ejaculated bull semen was extended in a Tris-citrate egg yolk extender containing various concentrations of BHT (0.5, 1.0, 2.0 and 3.0mM). Semen was frozen at -196 degrees C using 50 x 10(6) spermatozoa per 0.5 mL straws. Five straws from each treatment were thawed to assess the semen quality in terms of sperm motility, viability, plasma membrane integrity and acrosomal integrity. Post-thawed sperm motility was determined using a phase-contrast microscope. Viability, plasma membrane integrity and acrosomal integrity were evaluated by the Supravital Staining, hypo-osmotic swelling test and normal acrosomal reaction, respectively. The highest (P<0.05) motility, acrosomal integrity and hypo-osmotic swelling response of spermatozoa was achieved by addition of 1.0 and 2.0mM BHT to semen extender. However, highest (P<0.05) viability of spermatozoa was achieved by inclusion of 2.0mM BHT. The higher concentration of BHT (3.0mM) reduced the motility, acrosomal integrity, viability and hypo-osmotic swelling response of the spermatozoa compared to other concentration used. In conclusion, BHT when added in the semen extender can improve the semen quality of buffalo bulls.
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butylated hydroxytoluene inclusion in semen extender improves the post thawed semen quality of nili ravi buffalo bubalus bubalis
Theriogenology, 2009Co-Authors: A Ijaz, A Hussain, M Aleem, M S Yousaf, Habib Ur RehmanAbstract:Abstract The study was carried out to evaluate the potential impact of butylated hydroxytoluene (BHT) on the frozen–thawed semen quality of Nili-Ravi buffalo bulls. Ejaculated bull semen was extended in a Tris–citrate egg yolk extender containing various concentrations of BHT (0.5, 1.0, 2.0 and 3.0mM). Semen was frozen at −196°C using 50×10 6 spermatozoa per 0.5mL straws. Five straws from each treatment were thawed to assess the semen quality in terms of sperm motility, viability, plasma membrane integrity and acrosomal integrity. Post-thawed sperm motility was determined using a phase-contrast microscope. Viability, plasma membrane integrity and acrosomal integrity were evaluated by the Supravital Staining, hypo-osmotic swelling test and normal acrosomal reaction, respectively. The highest ( P P
Peter Smrco - One of the best experts on this subject based on the ideXlab platform.
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effect of bendiocarb on development of the chick embryo
Journal of Applied Toxicology, 2010Co-Authors: Eva Petrovova, Lenka Luptakova, Peter Massányi, Katarina Vdoviakova, David Mazensky, Peter SmrcoAbstract:Agrochemicals, including pesticides, are being used in increasing amounts in agriculture and are therefore potential environmental contaminants which may affect a variety of biological systems. The pesticide residues directly affect the embryos, disturbing their normal development and causing pathophysiological and morphological changes. We have observed embryotoxicity of cholinesterase inhibitor bendiocarb in the chick embryo. The pesticide dissolved in 10% acetone in water for injection was applied in a volume of 200 μl over the embryo through membrana papyracea at embryonic days (ED) 2, 3, 4, 5 and 10. The toxicity of bendiocarb was rather low, and lethal dose (LD50) decreased with advancing development from 0.97 mg per egg at ED 2 to 28.6 mg on ED 5. The malformations in surviving embryos were observed rarely (<2%) and occurred in both control and experimental groups. In the treatment at ED 5 and 10 there was a statistically significant reduction in body weight, but the maximum difference from controls was below 14%. In treated chick embryos on ED 3 and 4 was observed a small but not significant increase in number of dead cells using Supravital Staining. We conclude that bendiocarb possesses no significant toxicity in the avian embryo. Our analysis of bendiocarb embryotoxic potential in the chick embryo supports the earlier observations in other animal models, testifying to the relative safety of bendiocarb for the embryo or fetus. Copyright © 2010 John Wiley & Sons, Ltd.
