Actinobacillus pleuropneumoniae serotype 1 adhered to immobilized swine-lung collagen. Bacteria b... more Actinobacillus pleuropneumoniae serotype 1 adhered to immobilized swine-lung collagen. Bacteria bound to collagen type I, III, IV and V. At 5 min incubation, 30 % of bacteria adhered to collagen, reaching saturation in around 90 min. Treatment of bacteria with divalent-metal chelators diminished their attachment to collagen, and Ca 2+ but not Mg 2+ increased it, suggesting Ca 2+ dependence for adherence. Proteolytic enzymes drastically reduced bacterial adherence to collagen, showing that binding involved bacterial surface proteins. Porcine fibrinogen, haemoglobin and gelatin partially reduced collagen adhesion. A 60 kDa outer-membrane protein of A. pleuropneumoniae recognized the swine collagens by overlay. This membrane protein was apparently involved in adhesion to collagen and fibrinogen, but not to fibronectin and laminin. Antibodies against the 60 kDa protein inhibited the adhesion to collagen by 70 %, whereas pig convalescent-phase antibodies inhibited it by only 40 %. Serotypes 1 and 7 were the most adherent to pig collagen (taken as 100 %); serotypes 6 and 11 were the lowest (~50 %), and neither showed the 60 kDa adhesin to biotinylated collagens. By negative staining, cells were observed initially to associate with collagen fibres in a polar manner, and the adhesin was detected on the bacterial surface. The results suggest that swine-lung collagen is an important target for A. pleuropneumoniae colonization and spreading, and that the attachment to this protein could play a relevant role in pathogenesis.
Blastocystis hominis (Bh) is an eukaryotic organism of significant polymorphism and extraordinary... more Blastocystis hominis (Bh) is an eukaryotic organism of significant polymorphism and extraordinary diversity of size; Bh is an anaerobic microorganism and a gastrointestinal protozoan parasite of humans and primates with certain pathogenic potential.
A., ROSALES-ENCINA, J. L., . American trypanosomiasis: In situ and generalized features of parasi... more A., ROSALES-ENCINA, J. L., . American trypanosomiasis: In situ and generalized features of parasitism and inflammation kinetics in a murine model. Experimental Parasitology 83, 267-274. Mimicking the natural conditions of mammalian infection, metacyclic trypomastigote forms of a Mexican isolate (Ninoa) of Trypanosoma cruzi were inoculated into mice in order to study inflammation kinetics and parasite clearance at the inoculation site, parasite tropism to different organs, and local inflammatory cell infiltrates. Polymorphonuclear cells were detected at the inoculation site as early as 1 hr after inoculation. Peak cell infiltrate was observed at 24 hr; at 96 hr polymorphonuclear cells had disappeared. Mononuclear cell infiltrates began at 24 hr, peaking at Day 15, and then stared disappearing by Day 30. Antigens and parasites were detected by conventional techniques up to 15 min and thereafter became undetectable. Amplification of the hypervariable region of kinetoplast minicircle DNA by polymerase chain reaction was positive from 24 hr to Day 15, and the reaction became negative on Day 30. Myositis was observed in skeletal muscle from Days 7 to 180, it progressed from slight to severe, with an inflammation process which included macrophages, plasmatic cells, and a few eosinophils, the phenotype of the infiltrating cells included LyT2 / and LyT1 / on Day 30, and both cell populations decreased in parallel on Day 180. Antigen and parasite nests were present from Days 15 to 180; in muscle the earliest time at which minicircle DNA was detected was Day 7 and it was present until Day 180. Myocarditis was also observed; it developed from slight to severe in between Days 7 and 30, then gradually decreased, and cleared up. Mononuclear cell infiltrates in the myocardium were present from Days 7 to 180. Antigen and parasite nests were detected at Days 15 and 30 and disappeared at Day 180, although minicircle DNA was detected until the last day of observation. Both skeletal and heart muscles showed inflammatory reaction foci containing T. cruzi antigen. There was twice the number of foci in heart as in skeletal muscle. This ratio was maintained by Day 30; later skeletal muscle showed persistent inflammation which was practically cleared up in the heart. Parasites or antigen were not detected by Day 180 in both skeletal and cardiac muscle; however, minicircle DNA was amplified, indicating that an small proportion of parasites evaded immune response. According to these data, Mexican Ninoa Strain has a classification as biodeme 3. ᭧
Pfister, J.A., San Martin, F., Rosales, L., Sisson, D.V., Flores, E. and Bryant, F.C., 1989. Graz... more Pfister, J.A., San Martin, F., Rosales, L., Sisson, D.V., Flores, E. and Bryant, F.C., 1989. Grazing behaviour of llamas, alpacas and sheep in the Andes of Peru. Appl. Anita. Behav. Sci., Llamas, alpacas and sheep graze jointly in many herds in the Andes. As foraging behaviour may be an important aspect of resource partitioning among camelids and sheep, activity budgets and feeding patterns during one wet and one dry season were quantified. We found that llamas generally spent more time (P<0.05) at each feeding station than did alpacas and sheep. Bite rate differed (P < 0.05 ) among animal species with alpacas > llamas > sheep. Llamas and alpacas had greater (P<0.05) total grazing times than sheep. However, llamas divided their grazing time evenly among tall, coarse bunchgrasses and low-growing grasses, while alpacas and sheep spent the majority of their grazing time consuming low-growing grasses and/orbs. Camelids and sheep appear to occupy different foraging niches in the Andes. Llamas may be better adapted than alpacas and sheep to subsist on coarse forage in drier Andean regions as a consequence of their foraging behaviour.
Pfister, J.A., San Martin, F., Rosales, L., Sisson, D.V., Flores, E. and Bryant, F.C., 1989. Graz... more Pfister, J.A., San Martin, F., Rosales, L., Sisson, D.V., Flores, E. and Bryant, F.C., 1989. Grazing behaviour of llamas, alpacas and sheep in the Andes of Peru. Appl. Anita. Behav. Sci., Llamas, alpacas and sheep graze jointly in many herds in the Andes. As foraging behaviour may be an important aspect of resource partitioning among camelids and sheep, activity budgets and feeding patterns during one wet and one dry season were quantified. We found that llamas generally spent more time (P<0.05) at each feeding station than did alpacas and sheep. Bite rate differed (P < 0.05 ) among animal species with alpacas > llamas > sheep. Llamas and alpacas had greater (P<0.05) total grazing times than sheep. However, llamas divided their grazing time evenly among tall, coarse bunchgrasses and low-growing grasses, while alpacas and sheep spent the majority of their grazing time consuming low-growing grasses and/orbs. Camelids and sheep appear to occupy different foraging niches in the Andes. Llamas may be better adapted than alpacas and sheep to subsist on coarse forage in drier Andean regions as a consequence of their foraging behaviour.
¡ES VERDAD! nervioso, muy, muy terriblemente nervioso yo había sido y soy; ¿pero por qué dirán us... more ¡ES VERDAD! nervioso, muy, muy terriblemente nervioso yo había sido y soy; ¿pero por qué dirán ustedes que soy loco? La enfermedad había aguzado mis sentidos, no destruido, no entorpecido. Sobre todo estaba la penetrante capacidad de oír. Yo oí todas las cosas en el cielo y en la tierra. Yo oí muchas cosas en el infierno. ¿Cómo entonces soy yo loco? ¡Escuchen! y observen cuan razonablemente, cuan serenamente, puedo contarles toda la historia.
Actinobacillus pleuropneumoniae serotype 1 adhered to immobilized swine-lung collagen. Bacteria b... more Actinobacillus pleuropneumoniae serotype 1 adhered to immobilized swine-lung collagen. Bacteria bound to collagen type I, III, IV and V. At 5 min incubation, 30 % of bacteria adhered to collagen, reaching saturation in around 90 min. Treatment of bacteria with divalent-metal chelators diminished their attachment to collagen, and Ca 2+ but not Mg 2+ increased it, suggesting Ca 2+ dependence for adherence. Proteolytic enzymes drastically reduced bacterial adherence to collagen, showing that binding involved bacterial surface proteins. Porcine fibrinogen, haemoglobin and gelatin partially reduced collagen adhesion. A 60 kDa outer-membrane protein of A. pleuropneumoniae recognized the swine collagens by overlay. This membrane protein was apparently involved in adhesion to collagen and fibrinogen, but not to fibronectin and laminin. Antibodies against the 60 kDa protein inhibited the adhesion to collagen by 70 %, whereas pig convalescent-phase antibodies inhibited it by only 40 %. Serotypes 1 and 7 were the most adherent to pig collagen (taken as 100 %); serotypes 6 and 11 were the lowest (~50 %), and neither showed the 60 kDa adhesin to biotinylated collagens. By negative staining, cells were observed initially to associate with collagen fibres in a polar manner, and the adhesin was detected on the bacterial surface. The results suggest that swine-lung collagen is an important target for A. pleuropneumoniae colonization and spreading, and that the attachment to this protein could play a relevant role in pathogenesis.
Blastocystis hominis (Bh) is an eukaryotic organism of significant polymorphism and extraordinary... more Blastocystis hominis (Bh) is an eukaryotic organism of significant polymorphism and extraordinary diversity of size; Bh is an anaerobic microorganism and a gastrointestinal protozoan parasite of humans and primates with certain pathogenic potential.
A., ROSALES-ENCINA, J. L., . American trypanosomiasis: In situ and generalized features of parasi... more A., ROSALES-ENCINA, J. L., . American trypanosomiasis: In situ and generalized features of parasitism and inflammation kinetics in a murine model. Experimental Parasitology 83, 267-274. Mimicking the natural conditions of mammalian infection, metacyclic trypomastigote forms of a Mexican isolate (Ninoa) of Trypanosoma cruzi were inoculated into mice in order to study inflammation kinetics and parasite clearance at the inoculation site, parasite tropism to different organs, and local inflammatory cell infiltrates. Polymorphonuclear cells were detected at the inoculation site as early as 1 hr after inoculation. Peak cell infiltrate was observed at 24 hr; at 96 hr polymorphonuclear cells had disappeared. Mononuclear cell infiltrates began at 24 hr, peaking at Day 15, and then stared disappearing by Day 30. Antigens and parasites were detected by conventional techniques up to 15 min and thereafter became undetectable. Amplification of the hypervariable region of kinetoplast minicircle DNA by polymerase chain reaction was positive from 24 hr to Day 15, and the reaction became negative on Day 30. Myositis was observed in skeletal muscle from Days 7 to 180, it progressed from slight to severe, with an inflammation process which included macrophages, plasmatic cells, and a few eosinophils, the phenotype of the infiltrating cells included LyT2 / and LyT1 / on Day 30, and both cell populations decreased in parallel on Day 180. Antigen and parasite nests were present from Days 15 to 180; in muscle the earliest time at which minicircle DNA was detected was Day 7 and it was present until Day 180. Myocarditis was also observed; it developed from slight to severe in between Days 7 and 30, then gradually decreased, and cleared up. Mononuclear cell infiltrates in the myocardium were present from Days 7 to 180. Antigen and parasite nests were detected at Days 15 and 30 and disappeared at Day 180, although minicircle DNA was detected until the last day of observation. Both skeletal and heart muscles showed inflammatory reaction foci containing T. cruzi antigen. There was twice the number of foci in heart as in skeletal muscle. This ratio was maintained by Day 30; later skeletal muscle showed persistent inflammation which was practically cleared up in the heart. Parasites or antigen were not detected by Day 180 in both skeletal and cardiac muscle; however, minicircle DNA was amplified, indicating that an small proportion of parasites evaded immune response. According to these data, Mexican Ninoa Strain has a classification as biodeme 3. ᭧
Pfister, J.A., San Martin, F., Rosales, L., Sisson, D.V., Flores, E. and Bryant, F.C., 1989. Graz... more Pfister, J.A., San Martin, F., Rosales, L., Sisson, D.V., Flores, E. and Bryant, F.C., 1989. Grazing behaviour of llamas, alpacas and sheep in the Andes of Peru. Appl. Anita. Behav. Sci., Llamas, alpacas and sheep graze jointly in many herds in the Andes. As foraging behaviour may be an important aspect of resource partitioning among camelids and sheep, activity budgets and feeding patterns during one wet and one dry season were quantified. We found that llamas generally spent more time (P<0.05) at each feeding station than did alpacas and sheep. Bite rate differed (P < 0.05 ) among animal species with alpacas > llamas > sheep. Llamas and alpacas had greater (P<0.05) total grazing times than sheep. However, llamas divided their grazing time evenly among tall, coarse bunchgrasses and low-growing grasses, while alpacas and sheep spent the majority of their grazing time consuming low-growing grasses and/orbs. Camelids and sheep appear to occupy different foraging niches in the Andes. Llamas may be better adapted than alpacas and sheep to subsist on coarse forage in drier Andean regions as a consequence of their foraging behaviour.
Pfister, J.A., San Martin, F., Rosales, L., Sisson, D.V., Flores, E. and Bryant, F.C., 1989. Graz... more Pfister, J.A., San Martin, F., Rosales, L., Sisson, D.V., Flores, E. and Bryant, F.C., 1989. Grazing behaviour of llamas, alpacas and sheep in the Andes of Peru. Appl. Anita. Behav. Sci., Llamas, alpacas and sheep graze jointly in many herds in the Andes. As foraging behaviour may be an important aspect of resource partitioning among camelids and sheep, activity budgets and feeding patterns during one wet and one dry season were quantified. We found that llamas generally spent more time (P<0.05) at each feeding station than did alpacas and sheep. Bite rate differed (P < 0.05 ) among animal species with alpacas > llamas > sheep. Llamas and alpacas had greater (P<0.05) total grazing times than sheep. However, llamas divided their grazing time evenly among tall, coarse bunchgrasses and low-growing grasses, while alpacas and sheep spent the majority of their grazing time consuming low-growing grasses and/orbs. Camelids and sheep appear to occupy different foraging niches in the Andes. Llamas may be better adapted than alpacas and sheep to subsist on coarse forage in drier Andean regions as a consequence of their foraging behaviour.
¡ES VERDAD! nervioso, muy, muy terriblemente nervioso yo había sido y soy; ¿pero por qué dirán us... more ¡ES VERDAD! nervioso, muy, muy terriblemente nervioso yo había sido y soy; ¿pero por qué dirán ustedes que soy loco? La enfermedad había aguzado mis sentidos, no destruido, no entorpecido. Sobre todo estaba la penetrante capacidad de oír. Yo oí todas las cosas en el cielo y en la tierra. Yo oí muchas cosas en el infierno. ¿Cómo entonces soy yo loco? ¡Escuchen! y observen cuan razonablemente, cuan serenamente, puedo contarles toda la historia.
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