Two new species of trypanosomes (subgenus Schizotrypanum) in bats from southern Ontario

1981 ◽  
Vol 59 (3) ◽  
pp. 530-545 ◽  
Author(s):  
Susan M. Bower ◽  
Patrick T. K. Woo
Keyword(s):  
Homo Sapiens ◽  
Myotis Lucifugus ◽  
Deer Mice ◽  
Laboratory Mice ◽  
Southern Ontario ◽  
Laboratory Rats ◽  
Cardiac Muscles ◽  
Fresh Plasma ◽  
Centrifugation Technique

From November of 1976 to May of 1979, the blood of 529 bats from 12 sites in southern Ontario was examined for trypanosomes using the haematocrit centrifugation technique. Trypanosoma hedricki n.sp. was found in 62 of 216 Eptesicus fuscus and Trypanosoma myoti n.sp. in 16 of 313 Myotis lucifugus. Blood forms of both species were morphologically similar to Trypanosoma cruzi. These trypanosomes were readily cultured in diphasic blood–agar medium.Cultures of T. hedricki n.sp. and T. myoti n.sp. were infective when inoculated orally or injected intraperitoneally into laboratory reared E. fuscus and M. lucifugus respectively. Pseudocysts of amastigotes were found in cardiac muscles of both bat species and in the intestinal smooth muscle of M. lucifugus. Trypanosoma hedricki n.sp. was not infective to M. lucifugus nor was T. myoti n.sp. infective to E. fuscus. Unlike T. cruzi, cultures were not infective to Mus musculus, Peromyscus maniculatus, Microtus pennsylvanicus, Mesocricetus auratus, Rattus norvegicus, and Cavia porcellus.After in vitro incubation in fresh plasma from deer mice, hamsters, laboratory rats, guinea pigs, little brown bats, and Homo sapiens, T. hedricki n.sp. could not be cultured. However, positive cultures were obtained after incubation in fresh plasma from E. fuscus and occasionally in fresh plasma from laboratory mice. Positive cultures were always obtained when the plasma was heat inactivated.

Comparative studies of Giardia spp. in small mammals in southern Ontario. I. Prevalence and identity of the parasites with a taxonomic discussion of the genus

1978 ◽  
Vol 56 (6) ◽  
pp. 1348-1359 ◽  
Author(s):  
David R. Grant ◽  
Patrick T. K. Woo
Keyword(s):  
Rattus Norvegicus ◽  
Microtus Pennsylvanicus ◽  
Deer Mice ◽  
Laboratory Mice ◽  
Meadow Voles ◽  
Southern Ontario ◽  
Laboratory Rats ◽  
Wistar Strain ◽  
Brown Rat ◽  
Giardia Muris

Giardia microti Kofoid and Christiansen, 1915 was identified in 98.8% (322 of 326) of meadow voles (Microtus pennsylvanicus) and G. peromysci Filice, 1952 emend, in 98% (48 of 49) of deer mice (Peromyscus maniculatus) that were livetrapped at six locations in southern Ontario. One feral brown rat (Rattus norvegicus) was infected with Giardia simoni Lavier, 1924 and Giardia muris Grassi, 1881. Laboratory rats (Wistar strain) harboured only G. simoni and laboratory mice (C3H strain) were infected with G. muris. Golden hampsters (Mesocricetus auratus) were infected with Giardia mesocricetus Filice, 1952 emend.Giardia spp. were separated into two morphologically distinct groups. Trophozoites of G. muris and G. mesocricetus were almost as wide as long and had round or oval centrally situated median bodies. Trophozoites of G. microti, Giardia peromysci, and G. simoni were elongate with long curved median bodies lying perpendicular to the long axis of the trophozoite.Further differentiation of species was not possible by comparing trophozoite morphology but was accomplished by comparing the average lengths and widths of trophozoites.

Comparative studies of Giardia spp. in small mammals in southern Ontario. III. Duration and cyst production in natural and experimental infections

1979 ◽  
Vol 57 (2) ◽  
pp. 307-313 ◽  
Author(s):  
David R. Grant ◽  
Patrick T. K. Woo
Keyword(s):  
Small Mammals ◽  
Deer Mice ◽  
Meadow Voles ◽  
Southern Ontario ◽  
Laboratory Rats ◽  
Experimental Infections ◽  
Cyst Production ◽  
Faecal Samples ◽  
Giardia Muris ◽  
Rats And Mice

Experimental infections of Giardia-free laboratory rats and mice with their respective parasites (Giardia simoni in rats and Giardia muris in mice) demonstrated that the infections persisted for the duration of the study period (4 months). Similarly, naturally infected meadow voles (with Giardia microti) and deer mice (with Giardia peromysci) retained their infections during their captivity (6 months). Rigorous precautions were taken to prevent contamination and coprophagy. The relative numbers of cysts in consecutive faecal samples varied considerably and there were periods when the numbers of cysts were extremely low. The excretions of cysts were cyclical and there were periods of 7 and 8 days between peaks in laboratory rats and mice infected with G. simoni and G. muris respectively.

Comparative studies of Giardia spp. in small mammals in southern Ontario. II. Host specificity and infectivity of stored cysts

1978 ◽  
Vol 56 (6) ◽  
pp. 1360-1366 ◽  
Author(s):  
David R. Grant ◽  
Patrick T. K. Woo
Keyword(s):  
Deer Mice ◽  
Laboratory Mice ◽  
Temperature Dependent ◽  
Laboratory Rats ◽  
Exponential Decrease ◽  
Brown Rat ◽  
Cross Transmission ◽  
Rate Of Decline ◽  
Giardia Muris ◽  
Cessation Of Treatment

Carefully controlled cross transmission experiments showed that some species of Giardia (Giardia simoni from laboratory rats, Giardia muris from laboratory mice, and Giardia peromysci from deer mice) are highly host specific while others are not. Although Giardia microti infected hamsters, and Giardia mesocricetus infected laboratory rats, these species are morphologically dissimilar from the Giardia spp. which are normally found in these animals. This study also shows that there are two varieties or subspecies of G. muris. Giardia muris from laboratory mice and from a feral brown rat were identical in morphology and dimensions, but differed in host specificity.Infectivity of cysts of G. simoni in faecal suspensions stored at three temperatures was tested using the eosin dye test and by administering portions of suspensions to Giardia-free rats at regular intervals. An exponential decrease in the proportion of cysts that resisted penetration by eosin was observed. The rate of decline was temperature dependent. Rats could not be infected when less than approximately 50% of cysts in suspension were eosin negative.Metronidazole (Flagyl) and quinacrine hydrochloride (Atabrine) did not have a prophylactic effect in rats treated for 7 days. Infections were established in animals inoculated with cysts of G. simoni 24 h after cessation of treatment.

Plasma Contact Activation and Decrease of Factor V Activity on Negatively-Charged Polyelectrolytes

1984 ◽  
Vol 51 (01) ◽  
pp. 061-064 ◽  
Author(s):  
M C Boffa ◽  
B Dreyer ◽  
C Pusineri
Keyword(s):  
Time Dependent ◽  
Initial Contact ◽  
Factor Xii ◽  
Factor V ◽  
Contact Activation ◽  
Polyelectrolyte Complexes ◽  
Plasma Factor ◽  
Fresh Plasma ◽  
Direct Adsorption

SummaryThe effect of negatively-charged polymers, used in some artificial devices, on plasma clotting and kinin systems was studied in vitro using polyelectrolyte complexes.Contact activation was observed as an immediate, transient and surface-dependent phenomenon. After incubation of the plasma with the polymer a small decrease of factor XII activity was noticed, which corresponded to a greater reduction of prekallikrein activity and to a marked kinin release. No significant decrease of factor XII, prekallikrein, HMW kininogen could be detected immunologically. Only the initial contact of the plasma with the polyelectrolyte lead to activation, subsequently the surface became inert.Beside contact activation, factor V activity also decreased in the plasma. The decrease was surface and time-dependent. It was independent of contact factor activation, and appeared to be related to the sulfonated groups of the polymer. If purified factor V was used instead of plasma factor V, inactivation was immediate and not time-dependent suggesting a direct adsorption on the surface. A second incubation of the plasma-contacted polymer with fresh plasma resulted in a further loss of Factor V activity.

scholarly journals Shedding Light on the African Enigma: In Vitro Testing of Homo sapiens-Helicobacter pylori Coevolution

2021 ◽  
Vol 9 (2) ◽  
pp. 240
Author(s):  
Bruno Cavadas ◽  
Marina Leite ◽  
Nicole Pedro ◽  
Ana C. Magalhães ◽  
Joana Melo ◽  
...  
Keyword(s):  
Gene Expression ◽  
Helicobacter Pylori ◽  
Host Response ◽  
Homo Sapiens ◽  
European Ancestry ◽  
Genome Wide ◽  
Expression Host ◽  
H Pylori ◽  
Human Ancestry

The continuous characterization of genome-wide diversity in population and case–cohort samples, allied to the development of new algorithms, are shedding light on host ancestry impact and selection events on various infectious diseases. Especially interesting are the long-standing associations between humans and certain bacteria, such as the case of Helicobacter pylori, which could have been strong drivers of adaptation leading to coevolution. Some evidence on admixed gastric cancer cohorts have been suggested as supporting Homo-Helicobacter coevolution, but reliable experimental data that control both the bacterium and the host ancestries are lacking. Here, we conducted the first in vitro coinfection assays with dual human- and bacterium-matched and -mismatched ancestries, in African and European backgrounds, to evaluate the genome wide gene expression host response to H. pylori. Our results showed that: (1) the host response to H. pylori infection was greatly shaped by the human ancestry, with variability on innate immune system and metabolism; (2) African human ancestry showed signs of coevolution with H. pylori while European ancestry appeared to be maladapted; and (3) mismatched ancestry did not seem to be an important differentiator of gene expression at the initial stages of infection as assayed here.

scholarly journals The Molecular Genetics and Evolution of Red and Green Color Vision in Vertebrates

Genetics ◽  
2001 ◽  
Vol 158 (4) ◽  
pp. 1697-1710 ◽  
Author(s):  
Shozo Yokoyama ◽  
F Bernhard Radlwimmer
Keyword(s):  
Color Vision ◽  
Homo Sapiens ◽  
Amino Acid Sequences ◽  
Capra Hircus ◽  
Sciurus Carolinensis ◽  
Cave Fish ◽  
Vitro Assay ◽  
Green Color ◽  
Astyanax Fasciatus

Abstract To better understand the evolution of red-green color vision in vertebrates, we inferred the amino acid sequences of the ancestral pigments of 11 selected visual pigments: the LWS pigments of cave fish (Astyanax fasciatus), frog (Xenopus laevis), chicken (Gallus gallus), chameleon (Anolis carolinensis), goat (Capra hircus), and human (Homo sapiens); and the MWS pigments of cave fish, gecko (Gekko gekko), mouse (Mus musculus), squirrel (Sciurus carolinensis), and human. We constructed these ancestral pigments by introducing the necessary mutations into contemporary pigments and evaluated their absorption spectra using an in vitro assay. The results show that the common ancestor of vertebrates and most other ancestors had LWS pigments. Multiple regression analyses of ancestral and contemporary MWS and LWS pigments show that single mutations S180A, H197Y, Y277F, T285A, A308S, and double mutations S180A/H197Y shift the λmax of the pigments by −7, −28, −8, −15, −27, and 11 nm, respectively. It is most likely that this “five-sites” rule is the molecular basis of spectral tuning in the MWS and LWS pigments during vertebrate evolution.

scholarly journals Characterization and selective inhibition of myristoyl-CoA:protein N-myristoyltransferase from Trypanosoma brucei and Leishmania major

2006 ◽  
Vol 396 (2) ◽  
pp. 277-285 ◽  
Author(s):  
Chrysoula Panethymitaki ◽  
Paul W. Bowyer ◽  
Helen P. Price ◽  
Robin J. Leatherbarrow ◽  
Katherine A. Brown ◽  
...  
Keyword(s):  
Trypanosoma Brucei ◽  
Leishmania Major ◽  
Homo Sapiens ◽  
Selective Inhibition ◽  
Fungal Species ◽  
Chemotherapeutic Agents ◽  
Human Pathogens ◽  
Ic50 Values

The eukaryotic enzyme NMT (myristoyl-CoA:protein N-myristoyltransferase) has been characterized in a range of species from Saccharomyces cerevisiae to Homo sapiens. NMT is essential for viability in a number of human pathogens, including the fungi Candida albicans and Cryptococcus neoformans, and the parasitic protozoa Leishmania major and Trypanosoma brucei. We have purified the Leishmania and T. brucei NMTs as active recombinant proteins and carried out kinetic analyses with their essential fatty acid donor, myristoyl-CoA and specific peptide substrates. A number of inhibitory compounds that target NMT in fungal species have been tested against the parasite enzymes in vitro and against live parasites in vivo. Two of these compounds inhibit TbNMT with IC50 values of <1 μM and are also active against mammalian parasite stages, with ED50 (the effective dose that allows 50% cell growth) values of 16–66 μM and low toxicity to murine macrophages. These results suggest that targeting NMT could be a valid approach for the development of chemotherapeutic agents against infectious diseases including African sleeping sickness and Nagana.

Food supplement “carrageenan” and its effect on the organism

2020 ◽  
Author(s):  
O.E. Luneva ◽  
Keyword(s):  
Gastrointestinal Tract ◽  
Food Additives ◽  
Food Supplement ◽  
The Body ◽  
Laboratory Rats ◽  
Experimental Part ◽  
In Vivo Experiments ◽  
Physiological Processes

Food additives are positioned as harmless, although, their components affectthe physiological processes associated with the permeability of the wall of the gastrointestinal tract (GIT) and intestinal microbiota. This article describes thecarrageenan supplement and its effects on the body in in vitro and in vivo experiments. The experimental part is devoted to analysis of the intestinalmicrobiota of laboratory rats with the consumption of the carrageenan dietary supplement in the amount of about 4,4 % of the standard feed.

Synthetic Riboswitches for the Analysis of tRNA Processing by eukaryotic RNase P Enzymes

RNA ◽  
2022 ◽  
pp. rna.078814.121
Author(s):  
Anna Ender ◽  
Nadine Grafl ◽  
Tim Kolberg ◽  
Sven Findeiss ◽  
Peter F. Stadler ◽  
...  
Keyword(s):  
Homo Sapiens ◽  
Rnase P ◽  
Single Stranded Region ◽  
Domains Of Life ◽  
The Individual ◽  
The Impact ◽  
Individual Enzyme ◽  
Trna Precursor

Removal of the 5' leader region is an essential step in the maturation of tRNA molecules in all domains of life. This reaction is catalyzed by various RNase P activities, ranging from ribonucleoproteins with ribozyme activity to protein-only forms. In Escherichia coli, the efficiency of RNase P mediated cleavage can be controlled by computationally designed riboswitch elements in a ligand-dependent way, where the 5' leader sequence of a tRNA precursor is either sequestered in a hairpin structure or presented as a single-stranded region accessible for maturation. In the presented work, the regulatory potential of such artificial constructs is tested on different forms of eukaryotic RNase P enzymes – two protein-only RNase P enzymes (PRORP1 and PRORP2) from Arabidopsis thaliana and the ribonucleoprotein of Homo sapiens. The PRORP enzymes were analyzed in vitro as well as in vivo in a bacterial RNase P complementation system. We also tested in HEK293T cells whether the riboswitches remain functional with human nuclear RNase P. While the regulatory principle of the synthetic riboswitches applies for all tested RNase P enzymes, the results also show differences in the substrate requirements of the individual enzyme versions. Hence, such designed RNase P riboswitches represent a novel tool to investigate the impact of the structural composition of the 5'-leader on substrate recognition by different types of RNase P enzymes.

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