33 results on '"A Willms"'
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2. Apoptosis patterns in experimental Taenia solium and Taenia crassiceps strobilae from golden hamsters
- Author
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Presas, Ana María Fernández, Robert, Lilia, Jiménez, José Agustín, and Willms, Kaethe
- Published
- 2005
- Full Text
- View/download PDF
3. Ultrastructure of spermiogenesis and the spermatozoon in Taenia crassiceps strobilae WFU strain (Cestoda, Cyclophyllidea, Taeniidae) from golden hamsters
- Author
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Willms, Kaethe, Robert, Lilia, Jiménez, José Agustín, Everhart, Mary, and Kuhn, Raymond E.
- Published
- 2004
- Full Text
- View/download PDF
4. Ultrastructure of spermatogonia and spermatocyte lobules in Taenia solium strobilae (Cestoda, Cyclophyllidea, Taeniidae) from golden hamsters
- Author
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Willms, Kaethe, Caro, Jose Antonio, and Robert, Lilia
- Published
- 2003
- Full Text
- View/download PDF
5. Ultrastructure of smooth muscle, gap junctions and glycogen distribution in Taenia solium tapeworms from experimentally infected hamsters
- Author
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Willms, Kaethe, Robert, Lilia, and Caro, José
- Published
- 2003
- Full Text
- View/download PDF
6. Morphology of Gnathostoma spp. isolated from natural hosts in Sinaloa, Mexico
- Author
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Diaz Camacho, Sylvia P., Willms, Kaethe, Ramos, Magda, del Carmen de la Cruz Otero, Maria, Nawa, Yukifumi, and Akahane, Hiroshige
- Published
- 2002
- Full Text
- View/download PDF
7. Ultrastructural damage of Trypanosoma cruzi epimastigotes exposed to decomplemented immune sera
- Author
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Fernández-Presas, A., Zavala, Tay J., Becker Fauser, I., Merchant, M., Guerrero, Robert L., and Willms, K.
- Published
- 2001
- Full Text
- View/download PDF
8. Formation of calcareous corpuscles in the lumen of excretory canals of Taenia solium cysticerci
- Author
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Varga-Parada, L., Merchant, Marie Therese, Willms, Kaethe, and Laclette, J. P.
- Published
- 1999
- Full Text
- View/download PDF
9. Immunosuppression and inhibition of inflammation in mice induced by a small Taenia solium RNA-peptide to implanted T. solium metacestodes
- Author
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Tato, Patricia, White Jr., A. Clinton, Willms, Kaethe, Rodríguez, Daniel, Solano, Sandra, Sepúlveda, Jorge, and Molinari, J. L.
- Published
- 1996
- Full Text
- View/download PDF
10. Apoptosis patterns in experimental Taenia solium and Taenia crassiceps strobilae from golden hamsters
- Author
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Ana María Fernández Presas, Kaethe Willms, Lilia Robert, and José Agustín Jiménez
- Subjects
Programmed cell death ,Pathology ,medicine.medical_specialty ,Swine ,Cestoda ,Apoptosis ,Cell morphology ,Mice ,Cricetinae ,Taenia solium ,parasitic diseases ,medicine ,Animals ,Taeniasis ,Taenia crassiceps ,Mice, Inbred BALB C ,Mesocricetus ,Taenia ,General Veterinary ,biology ,General Medicine ,biology.organism_classification ,Molecular biology ,medicine.drug_formulation_ingredient ,Infectious Diseases ,Insect Science ,DNA fragmentation ,Parasitology - Abstract
Apoptosis or programmed cell death (PCD) patterns of two taeniid species, Taenia solium and Taenia crassiceps, were explored in adult tapeworms grown in golden hamsters. Animals were fed either ten viable T. solium cysticerci from naturally infected pigs or from T. crassiceps WFU strain maintained in Balb/c mice. Adult strobilae were recovered from the intestine at different times after infection and either frozen at -70 degrees C or fixed in paraformaldehyde-glutaraldehyde. Frozen sections were processed using the DNA fragmentation fluorescent TUNEL reagents and examined in an epifluorescent microscope. Fixed tissues were processed for light and electron microscopy. Typical apoptotic cells were found in the central core of scolex and strobilar tissues, mainly in the germinal tissue and subtegumentary areas. By the TUNEL technique, cells exhibited the characteristic fluorescent images of condensed nuclear chromatin. By light microscopy of thick sections stained with toluidine blue, we found a number of small rounded cells which had lost their cytoplasmic bridges and had shrunken nuclei with aggregated chromatin, cells which were found interspersed with normal syncytial cells. Similar cell morphology was confirmed by electron microscopy. Stunted viable worms, recovered with longer mature specimens, had very short strobilae and exhibited a large number of apoptotic cells in the germinal neck tissues. The results are consistent with the syncytial nature of these parasites, and strongly suggest that cell proliferation and PCD in these adult cestodes are continuous processes of the germinal tissue and tegumentary cytons.
- Published
- 2005
11. Ultrastructural damage of Trypanosoma cruzi epimastigotes exposed to decomplemented immune sera
- Author
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Ana María Fernández-Presas, Marie Therese Merchant, I. Becker Fauser, J. Tay Zavala, L. Robert Guerrero, and Kaethe Willms
- Subjects
Trypanosoma cruzi ,Antibodies, Protozoan ,Biology ,Mice ,Immune system ,Antigen ,parasitic diseases ,Animals ,Chagas Disease ,Antiserum ,Complement Inactivator Proteins ,General Veterinary ,Immune Sera ,Endoplasmic reticulum ,Kinetoplastida ,Complement System Proteins ,General Medicine ,biology.organism_classification ,Virology ,Molecular biology ,Microscopy, Electron ,Agglutination (biology) ,Infectious Diseases ,Insect Science ,Humoral immunity ,Parasitology ,Rabbits ,Thymidine - Abstract
The susceptibility of Trypanosoma cruzi epimastigotes to lysis by normal or immune sera in a complement-dependent reaction has been reported, but the effects induced directly by immune serum depleted of complement remain unstudied. The aim of this work was to study the ultrastructural alterations induced in T. cruzi epimastigotes by immune mouse or rabbit sera with or without complement. A local isolate of T. cruzi (Queretaro) was used in all experiments. Immune sera were raised in both mouse and rabbit by immunization with T. cruzi epimastigote antigens. Light microscopy showed intense agglutination of epimastigotes when incubated with decomplemented mouse or rabbit immune sera. A distinctive ultrastructural feature of this agglutination pattern was the fusion of plasma membranes and a pattern of intercrossing between subpellicular microtubules. Agglutination was associated with fragmentation of nuclear membranes and swelling of cytoplasm, Golgi cisternae, endoplasmic reticulum, mitochondria and kinetoplast membranes. Agglutinated parasites also incorporated trypan blue stain. Results of [3H]-thymidine incorporation confirmed that epimastigotes exposed to specific antibodies in the absence of complement were incapable of proliferating. Ultrastructural changes observed in epimastigote micrographs incubated with decomplemented immune mouse sera were statistically significant (P
- Published
- 2001
12. Formation of calcareous corpuscles in the lumen of excretory canals of Taenia solium cysticerci
- Author
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Marie Therese Merchant, Laura Vargas-Parada, Juan Pedro Laclette, and Kaethe Willms
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Swine ,Cestoda ,Lumen (anatomy) ,Nephridium ,Biology ,parasitic diseases ,Taenia solium ,medicine ,Animals ,Parasite hosting ,Muscle, Skeletal ,Platyhelminths ,Swine Diseases ,General Veterinary ,Cysticercosis ,Cysticercus ,General Medicine ,Anatomy ,biology.organism_classification ,Microscopy, Electron ,medicine.drug_formulation_ingredient ,Infectious Diseases ,Excretory system ,Insect Science ,Vacuoles ,Parasitology ,Calcareous - Abstract
Platyhelminths, like many other organisms, are capable of producing mineral concretions. In cestodes these are referred to as calcareous corpuscles. Studies on these concretions in different cestodes both in vivo and in vitro have resulted in a number of hypotheses on their origin, formation, and structure. Calcareous corpuscles are believed to be of cellular origin, although the kind of cell involved and the mechanisms of mineralization remain under discussion. In the present paper we show that formation of calcareous corpuscles in cysticerci of Taenia solium is not of intracellular origin, as described for other cestodes, but occurs extracellularly in the lumen of protonephridial ducts in a way similar to that proposed for trematodes. This finding enhances the function of the protonephridial ducts, at least in the larvae of T. solium, to the roles formerly ascribed to the calcareous corpuscles.
- Published
- 1999
13. In vivo albendazole treatment of Taenia crassiceps cysticerci strain WFU: proliferation, damage, and recovery
- Author
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E. Terrones Vargas, Rimma Zurabian, S. Ruíz-Velasco Acosta, Kaethe Willms, M. E. Cervera Hernández, and Laura Aguilar-Vega
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Cell ,Albendazole ,Parasite Load ,Microbiology ,Mice ,In vivo ,Parenchyma ,medicine ,Parasite hosting ,Animals ,Taeniasis ,Taenia crassiceps ,Anthelmintics ,Mice, Inbred BALB C ,Microscopy ,General Veterinary ,biology ,Taenia ,Animal Structures ,General Medicine ,Viral tegument ,biology.organism_classification ,Survival Analysis ,In vitro ,Disease Models, Animal ,Infectious Diseases ,medicine.anatomical_structure ,Insect Science ,Immunology ,Parasitology ,medicine.drug - Abstract
Taenia crassiceps has been widely experimented as a model for in vitro and in vivo studies on drug responses. The purpose of this study was to treat BALB/c mice infected with T. crassiceps strain WFU with commercially available albendazole and to analyze the reduction in parasite infrapopulations. Here, we describe the reduction and apparent damage of T. crassicceps WFU cysticerci in infected mice after antihelminthic drug treatment and subsequent inoculation of those treated parasites into a naive host. We were able to reduce significantly the parasite counts to 33 and 48 % after albendazole treatment for 20 or 25 days and compared with the untreated mice. We also observed morphological damage such as the partial blebbing in the tegument and parenchyma of treated parasites, as well as disorganized musculature and the loss of cell membranes in subtegumental tissue section. However, larvae from albendazole-treated mice inoculated into the next host were able to become re-established in the next murine host due, probably, to the survival of proliferative parasite cells.
- Published
- 2013
14. Immunosuppression and inhibition of inflammation in mice induced by a small Taenia solium RNA-peptide to implanted T. solium metacestodes
- Author
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Patricia Tato, Sandra Solano, Jorge Sepúlveda, A. Clinton White, José Luis Molinari, Kaethe Willms, and Daniel Rodriguez
- Subjects
Neutrophils ,Cestoda ,Antibodies, Helminth ,Down-Regulation ,Inflammation ,Lymphocyte Activation ,Microbiology ,Mice ,Immune system ,Antigen ,parasitic diseases ,Taenia solium ,medicine ,Animals ,Taeniasis ,Immunity, Cellular ,Mice, Inbred BALB C ,Granuloma ,General Veterinary ,biology ,General Medicine ,biology.organism_classification ,Eosinophils ,Metacestode ,medicine.drug_formulation_ingredient ,Infectious Diseases ,Antigens, Helminth ,Insect Science ,Rostellum (helminth) ,Immunology ,biology.protein ,Female ,Parasitology ,medicine.symptom ,Antibody ,Immunosuppressive Agents - Abstract
Subcutaneous implantation of Taenia solium metacestodes in mice induces an inflammatory reaction made up mainly of neutrophils and eosinophils after 12 days. Administration of a small RNA-peptide (metacestode factor, MF) purified from T. solium metacestodes significantly reduces the inflammatory site in both size and composition, yielding a very low number of eosinophils. The metacestodes implanted in control mice were completely destroyed and their remnants were surrounded by an intense inflammation predominantly made up of neutrophils and eosinophils. In contrast, metacestodes implanted in mice treated with MF showed apparently intact suckers, rostellum, hooks, and tegument. Inhibition of inflammation around the parasites was also observed in mice immunized with T. solium metacestode antigens and inoculated simultaneously with MF. Mice immunized only with T. solium metacestode antigens produced a granulomatous process around metacestodes that destroyed most of the large metacestode structures: suckers, rostellum, hooks, and tegument-wall tissues. Furthermore, treatment of mice with MF or implanted metacestodes decreased the antibody (P
- Published
- 1996
15. Specific antibodies induce apoptosis in Trypanosoma cruzi epimastigotes
- Author
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Ana María, Fernández-Presas, Patricia, Tato, Ingeborg, Becker, Sandra, Solano, Natalia, Copitin, Natalia, Kopitin, Miriam, Berzunza, Kaethe, Willms, Joselin, Hernández, and José Luis, Molinari
- Subjects
Trypanosoma cruzi ,Antibodies, Protozoan ,Apoptosis ,Biology ,Flow cytometry ,chemistry.chemical_compound ,Mice ,Annexin ,medicine ,In Situ Nick-End Labeling ,Animals ,Annexin A5 ,TUNEL assay ,Microbial Viability ,General Veterinary ,medicine.diagnostic_test ,Caspase 3 ,General Medicine ,Phosphatidylserine ,Complement System Proteins ,biology.organism_classification ,Molecular biology ,Agglutination (biology) ,Microscopy, Electron ,Infectious Diseases ,chemistry ,Terminal deoxynucleotidyl transferase ,Insect Science ,Parasitology ,Female - Abstract
The susceptibility of Trypanosoma cruzi epimastigotes to lysis by normal or immune sera in a complement-dependent reaction has been reported. Mouse immune sera depleted complement-induced damage in epimastigotes characterized by morphological changes and death. The purpose of this work was to study the mechanism of death in epimastigotes exposed to decomplemented mouse immune serum. Epimastigotes were maintained in RPMI medium. Immune sera were prepared in mice by immunization with whole crude epimastigote extracts. Viable epimastigotes were incubated with decomplemented normal or immune sera at 37 degrees C. By electron microscopy, agglutinated parasites showed characteristic patterns of membrane fusion between two or more parasites; this fusion also produced interdigitation of the subpellicular microtubules. Apoptosis was determined by flow cytometry using terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and annexin V assays. Nuclear features were examined by 4'-,6-diamidino-2'-phenylindole diHCI cytochemistry that demonstrated apoptotic nuclear condensation. Caspase activity was also measured. TUNEL results showed that parasites incubated with decomplemented immune sera took up 26% of specific fluorescence as compared to 1.3% in parasites incubated with decomplemented normal sera. The Annexin-V-Fluos staining kit revealed that epimastigotes incubated with decomplemented immune sera exposed phosphatidylserine on the external leaflet of the plasma membrane. The incubation of parasites with immune sera showed caspase 3 activity. We conclude that specific antibodies are able to induce agglutination and apoptosis in epimastigotes, although the pathway is not elucidated.
- Published
- 2009
16. The key steroidogenic enzyme 3beta-hydroxysteroid dehydrogenase in Taenia solium and Taenia crassiceps (WFU)
- Author
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Ana María Fernández Presas, Kaethe Willms, Marta C. Romano, and R.A. Valdez
- Subjects
Androstenediol ,endocrine system ,medicine.medical_specialty ,3-Hydroxysteroid Dehydrogenases ,medicine.drug_class ,Cestoda ,Dehydroepiandrosterone ,Biology ,Andrology ,Mice ,Internal medicine ,Cricetinae ,parasitic diseases ,Taenia solium ,medicine ,Animals ,Testosterone ,Incubation ,Taenia crassiceps ,Mice, Inbred BALB C ,General Veterinary ,Estradiol ,Staining and Labeling ,Taenia ,Nitroblue Tetrazolium ,General Medicine ,Cysticercus ,biology.organism_classification ,Androgen ,Culture Media ,Intestines ,medicine.drug_formulation_ingredient ,Infectious Diseases ,Endocrinology ,Insect Science ,Pregnenolone ,Parasitology ,Chromatography, Thin Layer ,medicine.drug - Abstract
Larval and adult stages of Taenia solium and Taenia crassiceps WFU strain were analyzed by histochemical and biochemical methods to determine the existence of steroid pathways. The presence of the key enzyme 3beta-hydroxisteroid-dehydrogenase (3beta-HSD) was examined in frozen sections of cysticerci obtained from mice and segments of tapeworms obtained from the intestine of hamsters. 3beta-HSD activity was detected by nitroblue-tetrazolium products after incubation with dehydroepiandrosterone, androstendiol, or pregnenolone. Tapeworm tissues exhibited 3beta-HSD activity in the subtegumentary areas of the neck and immature proglottids following incubation with androstendiol, as well as surrounding the testes in mature proglottids. T. solium cysticerci exhibited 3beta-HSD activity in the subtegumentary tissues. The synthesis of steroid hormones involving the activity of 3beta-HSD was studied in cysticerci or tapeworms incubated in the presence of tritiated steroid precursors. The culture media were analyzed by thin layer chromatography and showed synthesis of androstendiol, testosterone, and 17beta-estradiol by cysticerci, androstendiol, and 17beta-estradiol by tapeworms. The results strongly suggest the activity of 3beta-HSD in taeniid parasites that have at least a part of the enzymatic chain required for androgen and estrogen synthesis and that the enzymes are present in the larval stage and from the early strobilar stages to the mature proglottids.
- Published
- 2007
17. Ultrastructure of a spermatid transport system in the mature proglottids of experimental Taenia crassiceps (WFU strain)
- Author
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Lilia Robert and Kaethe Willms
- Subjects
Male ,endocrine system ,Cestoda ,Mice ,Vas Deferens ,Microscopy, Electron, Transmission ,Nucleated cell ,Testis ,medicine ,Animals ,Taeniasis ,Taenia crassiceps ,Mice, Inbred BALB C ,General Veterinary ,Spermatid ,biology ,Taenia ,Endoplasmic reticulum ,Vas deferens ,Leydig Cells ,Biological Transport ,General Medicine ,Anatomy ,biology.organism_classification ,Sertoli cell ,Spermatids ,Cell biology ,Infectious Diseases ,medicine.anatomical_structure ,Insect Science ,Ultrastructure ,Parasitology ,Female - Abstract
In classical textbooks of parasitology, the mature proglottids of taeniids are depicted as structures in which the individual testis are connected to the vas deferens through the vas efferens system, usually depicted as a network of channels. From our morphological analyses of proglottids in the cestode Taenia crassiceps, we have been unable to identify this channel network. It is unclear how the spermatids are transported from the testes to the vas deferens, as is unresolved the location of the cells responsible for the production of testosterone (Leydig cells) or the possible equivalent of Sertoli cells, necessary for the differentiation process of these cells. In this experimental work, we have examined the ultrastructure of tissues in the vicinity of the vas deferens in mature proglottids obtained from the intestines of hamsters infected with cysticerci from the peritoneum of infected mice. Worm tissues were fixed, processed, and sectioned for transmission electron microscopy. Significant areas of the testis epithelia emitted cytoplasmic projections surrounded by extracellular matrix, where they appear as septated pockets enclosing free axonemes and spermatids. Vas efferens walls are made up of nucleated cells with cytoplasm annealing to each other through cell membrane junctions. Lodged between the junctions are membrane-bound pouches with dense granules found as aggregates or aligned in a semicircular array. The efferens wall exhibits numerous spermatids emerging into the lumen, an observation that suggests the epithelial wall may have the maturing functions of Sertoli cells of vertebrates. Large cells adjacent to the vas efferens contained prominent rough endoplasmic reticulum and large mitochondria, characteristics described for Leydig cells of vertebrates. Our observations suggest that taeniid spermatids are either transported from the testes to the vas system by epithelial pockets or that the epithelial pockets may be cross-sections of a highly coiled vas efferens system.
- Published
- 2006
18. Ultrastructure of spermiogenesis and the spermatozoon in Taenia crassiceps strobilae WFU strain (Cestoda, Cyclophyllidea, Taeniidae) from golden hamsters
- Author
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Kaethe Willms, José Agustín Jiménez, Raymond E. Kuhn, Mary Everhart, and Lilia Robert
- Subjects
Axoneme ,Male ,endocrine system ,Spermiogenesis ,Cestoda ,Mice ,Cricetinae ,parasitic diseases ,Animals, Outbred Strains ,Animals ,Spermatogenesis ,Taenia crassiceps ,Mice, Inbred BALB C ,General Veterinary ,biology ,Mesocricetus ,Taenia ,urogenital system ,General Medicine ,Anatomy ,biology.organism_classification ,Spermatozoa ,Infectious Diseases ,Insect Science ,Taeniidae ,Ultrastructure ,Parasitology ,Female ,Cyclophyllidea - Abstract
Strobilae from Taenia crassiceps (WFU strain) were obtained from outbred hamsters (Mesocricetus auratus) by feeding them viable metacestodes maintained by intraperitoneal passage in female Balb/c mice. Mature and gravid proglottids from strobilae were recovered from hamster intestines and fixed for light and electron microscopy. By light microscopy, the expected structure of taeniid proglottids was observed. Ultrastructural analysis of ten proglottids showed that testicular follicles and vas deferens contained filiform spermatids, with a single axoneme, and an elongated helicoidal nucleus inserted between the axoneme and the spiraled cortical microtubules. At the apical cone, a single crest-like body was found and mature spermatids also exhibited transverse intracytoplasmic walls. The morphology and characters of the spermatids in T. crassiceps conform to type III spermiogenesis, which has been described in other taeniids.
- Published
- 2003
19. Ultrastructure of spermatogonia and spermatocyte lobules in Taenia solium strobilae (Cestoda, Cyclophyllidea, Taeniidae) from golden hamsters
- Author
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Jose A. Caro, Lilia Robert, and Kaethe Willms
- Subjects
Male ,Spermiogenesis ,Spermatocyte ,Spermatocytes ,Cricetinae ,parasitic diseases ,Taenia solium ,medicine ,Animals, Outbred Strains ,Animals ,Intestinal Diseases, Parasitic ,Life Cycle Stages ,General Veterinary ,biology ,Mesocricetus ,Cysticercosis ,General Medicine ,Anatomy ,biology.organism_classification ,Spermatogonia ,Cell biology ,medicine.drug_formulation_ingredient ,Infectious Diseases ,medicine.anatomical_structure ,Insect Science ,Ultrastructure ,Taeniidae ,Parasitology ,Cyclophyllidea ,Spermatogenesis ,Cortical microtubule - Abstract
Golden hamsters (Mesocricetus auratus) were infected with Taenia solium metacestodes dissected from infected pig meat. Adult worms were collected from hamster intestines of animals killed 5-60 days post-infection (dpi), incubated in RPMI 1640 medium with or without colchicine, fixed and processed for transmission electron microscopy (TEM). Sections for light microscopy from 40 different blocks with scolex, immature and mature proglottids were photographed. Thin sections were cut from 25 selected blocks, examined and photographed with TEM. Metaphase mitosis figures were observed in the subtegument of the germinative tissue and interpreted as germ cell precursors. In immature proglottids (20 dpi), discrete cell clusters of three to four cells surrounded by a thin cytoplasmic envelope were identified along the inner border of the lateral excretory ducts. These were also observed in more mature proglottids (40-60 dpi) as clusters of eight cells enclosed in a cytoplasmic enve- lope, with nuclei of spermatogonia exhibiting the synaptolems of primary meiotic cells. In mature pro- glottids from 45 dpi, a large number of spermatocyte lobules were found, exhibiting different stages of spermatogenesis from primary spermatocytes to ma- ture filiform spermatids with a single axoneme, annu- lar nucleus and spiral cortical microtubules, similar to spermatozoa described for type III spermiogenesis of species of the family Taeniidae. All mature spermatocyte lobules were enclosed in a highly orga- nized cellular envelope and surrounded by a basal lamina. The envelopes contained a number of distinct organelles, seen in cross-section as discrete lattices of microtubules located between two layers of plasma membrane, as well as thickened furled cytoplasm with numerous strands of rough endoplasmic reticulum and pockets of microtubules.
- Published
- 2002
20. Morphology of Gnathostoma spp. isolated from natural hosts in Sinaloa, Mexico
- Author
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Maria del Carmen de la Cruz Otero, Sylvia Páz Díaz Camacho, Magda Luz Zazueta Ramos, Kaethe Willms, Yukifumi Nawa, and Hiroshige Akahane
- Subjects
Zoology ,Egretta ,Spirurida Infections ,Gnathostoma spinigerum ,Birds ,Fish Diseases ,Dormitator latifrons ,Species Specificity ,Cichlid ,Animals ,Gobiomorus ,Gnathostoma ,Mexico ,Catfishes ,General Veterinary ,biology ,Ecology ,Bird Diseases ,fungi ,Fishes ,General Medicine ,biology.organism_classification ,Fat sleeper ,Infectious Diseases ,Insect Science ,Larva ,Microscopy, Electron, Scanning ,Parasitology ,Catfish - Abstract
Gnathostomosis is an emerging public health problem in Sinaloa, Mexico, where an increasing number of human cases have been diagnosed since 1989. The present study was carried out to determine the presence of the parasite in other natural hosts from the area. Birds, fish, opossums and raccoons were captured from local dams and lagoons. The flesh from bird and fish specimens was ground and examined under a 100 W light bulb. Larvae were processed for light and electron microscopy. A total of 368 advanced stage 3 (AL3) larvae were found in 300 ichthyophagous birds, with Egretta alba exhibiting the highest infection rate. A total of 4,156 fish were examined, of which six species were infected with AL3 larvae: Arius guatemalensis (blue sea catfish), Dormitator latifrons (Pacific fat sleeper), Gobiomorus sp. (fat sleeper), Oreochromis sp. (Nile tilapia), Cichlasoma beani (Sinaloan cichlid or green guapote) and Eleotris picta (spotted sleeper). Twenty larvae from birds were used to infect domestic cats and dogs. Young adult worms were recovered from the stomach of a cat with a 17 day infection and from a dog with a 35 day infection. Larvae exhibited four rows of hooklets on the head bulb, whereas the young adults had nine rows of hooklets. The cuticular spines of adult worms along the body evolved from single-pointed, bi- or trifurcated spines. Nuclei were counted in intestinal cells examined in serial sections of larvae recovered from a great heron and a fish, in which a mean of 1.6 nuclei/cell was found, corresponding to data published for Gnathostoma binucleatum. Although the external morphology of both larvae and adults are in agreement with previous descriptions of Gnathostoma spinigerum, the results indicate that natural host infections in Sinaloa may be caused by either G. spinigerum or G. binucleatum.
- Published
- 2001
21. In vivo albendazole treatment of Taenia crassiceps cysticerci strain WFU: proliferation, damage, and recovery
- Author
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Zurabian, R., primary, Aguilar-Vega, L., additional, Terrones Vargas, E., additional, Cervera Hernández, M. E., additional, Willms, K., additional, and Ruíz-Velasco Acosta, S., additional
- Published
- 2013
- Full Text
- View/download PDF
22. Erratum to: Specific antibodies induce apoptosis in Trypanosoma cruzi epimastigotes
- Author
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Fernández-Presas, Ana María, primary, Tato, Patricia, additional, Becker, Ingeborg, additional, Solano, Sandra, additional, Copitin, Natalia, additional, Berzunza, Miriam, additional, Willms, Kaethe, additional, Hernández, Joselin, additional, and Molinari, José Luis, additional
- Published
- 2010
- Full Text
- View/download PDF
23. Specific antibodies induce apoptosis in Trypanosoma cruzi epimastigotes
- Author
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Fernández-Presas, Ana María, primary, Tato, Patricia, additional, Becker, Ingeborg, additional, Solano, Sandra, additional, Kopitin, Natalia, additional, Berzunza, Miriam, additional, Willms, Kaethe, additional, Hernández, Joselin, additional, and Molinari, José Luis, additional
- Published
- 2010
- Full Text
- View/download PDF
24. Erratum to: Specific antibodies induce apoptosis in Trypanosoma cruzi epimastigotes
- Author
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Joselin Hernández, José Luis Molinari, Kaethe Willms, Patricia Tato, Sandra Solano, Miriam Berzunza, Natalia Copitin, Ingeborg Becker, and Ana María Fernández-Presas
- Subjects
medicine.medical_specialty ,General Veterinary ,biology ,General Medicine ,biology.organism_classification ,Microbiology ,Specific antibody ,Infectious Diseases ,Medical microbiology ,Apoptosis ,Insect Science ,medicine ,Parasitology ,Trypanosoma cruzi - Published
- 2010
25. The key steroidogenic enzyme 3β-hydroxysteroid dehydrogenase in Taenia solium and Taenia crassiceps (WFU)
- Author
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Fernández Presas, Ana María, primary, Valdez, Ricardo A., additional, Willms, Kaethe, additional, and Romano, Marta C., additional
- Published
- 2008
- Full Text
- View/download PDF
26. Ultrastructure of a spermatid transport system in the mature proglottids of experimental Taenia crassiceps (WFU strain)
- Author
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Willms, Kaethe, primary and Robert, Lilia, additional
- Published
- 2007
- Full Text
- View/download PDF
27. Ultrastructural damage of Trypanosoma cruzi epimastigotes exposed to decomplemented immune sera
- Author
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A., Fernández-Presas, primary, Zavala, Tay, additional, Fauser, I. Becker, additional, M., Merchant, additional, Guerrero, Robert, additional, and K., Willms, additional
- Published
- 2001
- Full Text
- View/download PDF
28. The key steroidogenic enzyme 3β-hydroxysteroid dehydrogenase in Taenia solium and Taenia crassiceps (WFU).
- Author
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Ana Fernández Presas, Ricardo Valdez, Kaethe Willms, and Marta Romano
- Subjects
ENZYMES ,TAENIA ,PARASITES ,DEHYDROGENASES ,STEROIDS ,CYSTICERCOSIS ,TAPEWORMS ,HAMSTERS - Abstract
Abstract Larval and adult stages of Taenia solium and Taenia crassiceps WFU strain were analyzed by histochemical and biochemical methods to determine the existence of steroid pathways. The presence of the key enzyme 3β-hydroxisteroid-dehydrogenase (3β-HSD) was examined in frozen sections of cysticerci obtained from mice and segments of tapeworms obtained from the intestine of hamsters. 3β-HSD activity was detected by nitroblue-tetrazolium products after incubation with dehydroepiandrosterone, androstendiol, or pregnenolone. Tapeworm tissues exhibited 3β-HSD activity in the subtegumentary areas of the neck and immature proglottids following incubation with androstendiol, as well as surrounding the testes in mature proglottids. T. solium cysticerci exhibited 3β-HSD activity in the subtegumentary tissues. The synthesis of steroid hormones involving the activity of 3β-HSD was studied in cysticerci or tapeworms incubated in the presence of tritiated steroid precursors. The culture media were analyzed by thin layer chromatography and showed synthesis of androstendiol, testosterone, and 17β-estradiol by cysticerci, androstendiol, and 17β-estradiol by tapeworms. The results strongly suggest the activity of 3β-HSD in taeniid parasites that have at least a part of the enzymatic chain required for androgen and estrogen synthesis and that the enzymes are present in the larval stage and from the early strobilar stages to the mature proglottids. [ABSTRACT FROM AUTHOR]
- Published
- 2008
29. Ultrastructure of a spermatid transport system in the mature proglottids of experimental Taenia crassiceps (WFU strain).
- Author
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Kaethe Willms and Lilia Robert
- Subjects
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TESTOSTERONE , *CYTOPLASM , *ELECTRON microscopy , *PROTOPLASM - Abstract
Abstract  In classical textbooks of parasitology, the mature proglottids of taeniids are depicted as structures in which the individual testis are connected to the vas deferens through the vas efferens system, usually depicted as a network of channels. From our morphological analyses of proglottids in the cestode Taenia crassiceps, we have been unable to identify this channel network. It is unclear how the spermatids are transported from the testes to the vas deferens, as is unresolved the location of the cells responsible for the production of testosterone (Leydig cells) or the possible equivalent of Sertoli cells, necessary for the differentiation process of these cells. In this experimental work, we have examined the ultrastructure of tissues in the vicinity of the vas deferens in mature proglottids obtained from the intestines of hamsters infected with cysticerci from the peritoneum of infected mice. Worm tissues were fixed, processed, and sectioned for transmission electron microscopy. Significant areas of the testis epithelia emitted cytoplasmic projections surrounded by extracellular matrix, where they appear as septated pockets enclosing free axonemes and spermatids. Vas efferens walls are made up of nucleated cells with cytoplasm annealing to each other through cell membrane junctions. Lodged between the junctions are membrane-bound pouches with dense granules found as aggregates or aligned in a semicircular array. The efferens wall exhibits numerous spermatids emerging into the lumen, an observation that suggests the epithelial wall may have the maturing functions of Sertoli cells of vertebrates. Large cells adjacent to the vas efferens contained prominent rough endoplasmic reticulum and large mitochondria, characteristics described for Leydig cells of vertebrates. Our observations suggest that taeniid spermatids are either transported from the testes to the vas system by epithelial pockets or that the epithelial pockets may be cross-sections of a highly coiled vas efferens system. [ABSTRACT FROM AUTHOR]
- Published
- 2007
- Full Text
- View/download PDF
30. Taeniid tapeworm responses to in vitro glucose.
- Author
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Kaethe Willms, Ana María Fernández Presas, José Agustín Jiménez, Abraham Landa, Rimma Zurabián, María Eugenia Juárez Ugarte, and Lilia Robert
- Abstract
Abstract Experimental taeniid strobilae from Taenia solium and T. crassiceps (WFU strain) were incubated for 0–72 h in 0, 5 or 20 mM glucose solutions and further exposed for 15 min to the gap junction fluorochrome Lucifer Yellow. Frozen sections were obtained from each worm and observed under an epifluorescent microscope. Worm sections from strobilae incubated with glucose, revealed intense fluorescence in the base of the tegumentary surface, suggesting that this tissue behaves as a gap junction complex. Fluorescence intensity differences between control worms not exposed to glucose and worms incubated with glucose, were highly significant. The results demonstrate that under in vitro conditions, glucose is taken up along the whole strobilar tegument in both taeniid species, suggesting, that although taeniids attached to the duodenum probably take up most of their nutrients directly from the mucosal wall, the capacity for absorbing glucose along the tegumentary surface is always active and may increase the survival capacity of these intestinal worms by promoting glucose absorption at other points in the intestinal lumen. [ABSTRACT FROM AUTHOR]
- Published
- 2005
31. Ultrastructure of spermatogonia and spermatocyte lobules in Taenia solium strobilae (Cestoda, Cyclophyllidea, Taeniidae) from golden hamsters.
- Author
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Kaethe Willms, Jose Antonio Caro, and Lilia Robert
- Subjects
GOLDEN hamster ,COLCHICINE ,TRANSMISSION electron microscopy ,TAPEWORMS - Abstract
Golden hamsters ( Mesocricetus auratus) were infected with Taenia solium metacestodes dissected from infected pig meat. Adult worms were collected from hamster intestines of animals killed 5?60 days post-infection (dpi), incubated in RPMI 1640 medium with or without colchicine, fixed and processed for transmission electron microscopy (TEM). Sections for light microscopy from 40 different blocks with scolex, immature and mature proglottids were photographed. Thin sections were cut from 25 selected blocks, examined and photographed with TEM. Metaphase mitosis figures were observed in the subtegument of the germinative tissue and interpreted as germ cell precursors. In immature proglottids (20 dpi), discrete cell clusters of three to four cells surrounded by a thin cytoplasmic envelope were identified along the inner border of the lateral excretory ducts. These were also observed in more mature proglottids (40?60 dpi) as clusters of eight cells enclosed in a cytoplasmic envelope, with nuclei of spermatogonia exhibiting the synaptolems of primary meiotic cells. In mature proglottids from 45 dpi, a large number of spermatocyte lobules were found, exhibiting different stages of spermatogenesis from primary spermatocytes to mature filiform spermatids with a single axoneme, annular nucleus and spiral cortical microtubules, similar to spermatozoa described for type III spermiogenesis of species of the family Taeniidae. All mature spermatocyte lobules were enclosed in a highly organized cellular envelope and surrounded by a basal lamina. The envelopes contained a number of distinct organelles, seen in cross-section as discrete lattices of microtubules located between two layers of plasma membrane, as well as thickened furled cytoplasm with numerous strands of rough endoplasmic reticulum and pockets of microtubules. [ABSTRACT FROM AUTHOR]
- Published
- 2003
32. Ultrastructure of spermatogonia and spermatocyte lobules inTaenia soliumstrobilae (Cestoda, Cyclophyllidea, Taeniidae) from golden hamsters
- Author
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Willms, Kaethe, Caro, Jose, and Robert, Lilia
- Abstract
Golden hamsters (Mesocricetus auratus)were infected withTaenia soliummetacestodes dissected from infected pig meat. Adult worms were collected from hamster intestines of animals killed 5–60 days post-infection (dpi), incubated in RPMI 1640 medium with or without colchicine, fixed and processed for transmission electron microscopy (TEM). Sections for light microscopy from 40 different blocks with scolex, immature and mature proglottids were photographed. Thin sections were cut from 25 selected blocks, examined and photographed with TEM. Metaphase mitosis figures were observed in the subtegument of the germinative tissue and interpreted as germ cell precursors. In immature proglottids (20 dpi), discrete cell clusters of three to four cells surrounded by a thin cytoplasmic envelope were identified along the inner border of the lateral excretory ducts. These were also observed in more mature proglottids (40–60 dpi) as clusters of eight cells enclosed in a cytoplasmic envelope, with nuclei of spermatogonia exhibiting the synaptolems of primary meiotic cells. In mature proglottids from 45 dpi, a large number of spermatocyte lobules were found, exhibiting different stages of spermatogenesis from primary spermatocytes to mature filiform spermatids with a single axoneme, annular nucleus and spiral cortical microtubules, similar to spermatozoa described for type III spermiogenesis of species of the family Taeniidae. All mature spermatocyte lobules were enclosed in a highly organized cellular envelope and surrounded by a basal lamina. The envelopes contained a number of distinct organelles, seen in cross-section as discrete lattices of microtubules located between two layers of plasma membrane, as well as thickened furled cytoplasm with numerous strands of rough endoplasmic reticulum and pockets of microtubules.Golden hamsters (Mesocricetus auratus)were infected withTaenia soliummetacestodes dissected from infected pig meat. Adult worms were collected from hamster intestines of animals killed 5–60 days post-infection (dpi), incubated in RPMI 1640 medium with or without colchicine, fixed and processed for transmission electron microscopy (TEM). Sections for light microscopy from 40 different blocks with scolex, immature and mature proglottids were photographed. Thin sections were cut from 25 selected blocks, examined and photographed with TEM. Metaphase mitosis figures were observed in the subtegument of the germinative tissue and interpreted as germ cell precursors. In immature proglottids (20 dpi), discrete cell clusters of three to four cells surrounded by a thin cytoplasmic envelope were identified along the inner border of the lateral excretory ducts. These were also observed in more mature proglottids (40–60 dpi) as clusters of eight cells enclosed in a cytoplasmic envelope, with nuclei of spermatogonia exhibiting the synaptolems of primary meiotic cells. In mature proglottids from 45 dpi, a large number of spermatocyte lobules were found, exhibiting different stages of spermatogenesis from primary spermatocytes to mature filiform spermatids with a single axoneme, annular nucleus and spiral cortical microtubules, similar to spermatozoa described for type III spermiogenesis of species of the family Taeniidae. All mature spermatocyte lobules were enclosed in a highly organized cellular envelope and surrounded by a basal lamina. The envelopes contained a number of distinct organelles, seen in cross-section as discrete lattices of microtubules located between two layers of plasma membrane, as well as thickened furled cytoplasm with numerous strands of rough endoplasmic reticulum and pockets of microtubules.
- Published
- 2003
- Full Text
- View/download PDF
33. Morphology of Gnathostoma spp. isolated from natural hosts in Sinaloa, Mexico
- Author
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Camacho, Sylvia P. Diaz, Willms, Kaethe, Ramos, Magda, Otero, Maria del Carmen de la Cruz, Nawa, Yukifumi, and Akahane, Hiroshige
- Abstract
Abstract. Gnathostomosis is an emerging public health problem in Sinaloa, Mexico, where an increasing number of human cases have been diagnosed since 1989. The present study was carried out to determine the presence of the parasite in other natural hosts from the area. Birds, fish, opossums and raccoons were captured from local dams and lagoons. The flesh from bird and fish specimens was ground and examined under a 100 W light bulb. Larvae were processed for light and electron microscopy. A total of 368 advanced stage 3 (AL3) larvae were found in 300 ichthyophagous birds, with Egretta alba exhibiting the highest infection rate. A total of 4,156 fish were examined, of which six species were infected with AL3 larvae: Arius guatemalensis (blue sea catfish), Dormitator latifrons (Pacific fat sleeper), Gobiomorus sp. (fat sleeper), Oreochromis sp. (Nile tilapia), Cichlasoma beani (Sinaloan cichlid or green guapote) and Eleotris picta (spotted sleeper). Twenty larvae from birds were used to infect domestic cats and dogs. Young adult worms were recovered from the stomach of a cat with a 17 day infection and from a dog with a 35 day infection. Larvae exhibited four rows of hooklets on the head bulb, whereas the young adults had nine rows of hooklets. The cuticular spines of adult worms along the body evolved from single-pointed, bi- or trifurcated spines. Nuclei were counted in intestinal cells examined in serial sections of larvae recovered from a great heron and a fish, in which a mean of 1.6 nuclei/cell was found, corresponding to data published for Gnathostoma binucleatum. Although the external morphology of both larvae and adults are in agreement with previous descriptions of Gnathostoma spinigerum, the results indicate that natural host infections in Sinaloa may be caused by either G. spinigerum or G. binucleatum.
- Published
- 2002
- Full Text
- View/download PDF
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