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Bernard Marchand - One of the best experts on this subject based on the ideXlab platform.
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Ultrastructural study of vitellogenesis and oogenesis of Metadena depressa (Stossich, 1883) Linton, 1910 (Digenea, Cryptogonimidae), Intestinal Parasite of Dentex dentex (Pisces, Teleostei).
Comptes Rendus Biologies, 2012Co-Authors: Samuel Greani, Yann Quilichini, Josephine Foata, Zdzisław Swiderski, Bernard MarchandAbstract:The ultrastructural organization of the female reproductive system of Metadena depressa, digenean Intestinal Parasite of Sparidae (Dentex dentex), was investigated by electron microscopy. The vitellogenesis is divided into four stages: stage I, vitellocytes have a cytoplasm mainly filled with ribosomes and few mitochondria; stage II, beginning of the synthetic activity; stage III, active shell globule clusters synthesis; stage IV, mature vitellocytes are filled with shell globule clusters and generally contain several large lipid droplets. Glycogen granules are grouped at the periphery of the cell. The three stages of the oogenesis process take place in the ovary: stage I, oogonia are undifferentiated small cells located at the periphery of the organ; stage II, primary oocytes possess a higher nucleo-cytoplasmic ratio and a nucleus with a nucleolus and synaptonemal complexes indicating the zygotene-pachytene stage of the first meiotic division; stage III, mature oocytes are located in the proximal region of the organ and possess a cytoplasmic chromatoid body and cortical granules in a monolayer close to the periphery of the cell.
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ultrastructural study of vitellogenesis of aphallus tubarium rudolphi 1819 poche 1926 digenea cryptogonimidae an Intestinal Parasite of dentex dentex pisces teleostei
Journal of Parasitology, 2012Co-Authors: Samuel Greani, Yann Quilichini, Josephine Foata, Bernard MarchandAbstract:Abstract: Vitellogenesis of Aphallus tubarium, an Intestinal Parasite of Sparidae (Dentex dentex), was studied by transmission electron microscopy. The ultrastructural features allowed us to distinguish 4 stages in the vitellogenesis process. In stage 1, vitellocytes have a cytoplasm mainly filled with ribosomes, but few mitochondria. In stage 2, there is an increase in amount of endoplasmic reticulum and few Golgi complexes. There is production of shell globules that coalesce into clusters in stage 3; some glycogen particles are observed via the Thiery method. Finally, in stage 4, mature vitellocytes are filled with shell globule clusters and generally contain a large lipid droplet. Glycogen particles are grouped at the periphery of the cell.
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Ultrastructural study of vitellogenesis of Aphallus tubarium (Rudolphi, 1819) Poche, 1926 (Digenea: Cryptogonimidae), an Intestinal Parasite of Dentex dentex (Pisces: Teleostei).
J Parasitol, 2012Co-Authors: Samuel Greani, Yann Quilichini, Josephine Foata, Bernard MarchandAbstract:Vitellogenesis of Aphallus tubarium, an Intestinal Parasite of Sparidae (Dentex dentex ), was studied by transmission electron microscopy. The ultrastructural features allowed us to distinguish 4 stages in the vitellogenesis process. In stage 1, vitellocytes have a cytoplasm mainly filled with ribosomes, but few mitochondria. In stage 2, there is an increase in amount of endoplasmic reticulum and few Golgi complexes. There is production of shell globules that coalesce into clusters in stage 3; some glycogen particles are observed via the Thiéry method. Finally, in stage 4, mature vitellocytes are filled with shell globule clusters and generally contain a large lipid droplet. Glycogen particles are grouped at the periphery of the cell.
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spermatozoon ultrastructure of gyliauchen sp digenea gyliauchenidae an Intestinal Parasite of siganus fuscescens pisces teleostei
The Biological Bulletin, 2011Co-Authors: Yann Quilichini, Josephine Foata, Jean-lou Justine, Rodney A Bray, Bernard MarchandAbstract:The ultrastructure of the mature spermatozoon of Gyliauchen sp., a Parasite of the dusky rabbitfish Siganus fuscescens, was studied by transmission electron microscopy. The spermatozoon possesses two axonemes of the 9+“1” pattern of Trepaxonemata, four attachment zones, one mitochondrion, a nucleus, cortical microtubules, external ornamentation of the plasma membrane, and spine-like bodies. The main characteristics of this spermatozoon are the presence of one mitochondrion, spine-like bodies not associated with the external ornamentation, and a posterior extremity of type 3 that is characterized by the following sequence: posterior extremity of the nucleus then posterior extremity of the second axoneme. Numerous other ultrastructural features are also discussed and compared to the digenean spermatology literature. This is the first study of a member of the Gyliauchenidae and the fourth within the Lepocreadioidea. The results show that many ultrastructural characters are variable within this superfamily an...
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spermiogenesis and spermatozoon ultrastructure of nicolla wisniewskii digenea opecoelidae an Intestinal Parasite of brown trout salmo trutta pisces teleostei
Journal of Parasitology, 2007Co-Authors: Yann Quilichini, Josephine Foata, Antoine Orsini, Bernard MarchandAbstract:Spermiogenesis and ultrastructure of spermatozoon of Nicolla wisniewskii (Digenea, Opecoelidae), an Intestinal Parasite of Salmo trutta, were studied by electron microscopy. Spermiogenesis follows the general pattern found in the Digenea. It begins with the formation of a differentiation zone, including striated rootlets associated with 2 centrioles and an intercentriolar body. The flagella undergo a rotation of greater than 90°. Then, their fusion with the median cytoplasmic process is proximodistal and asynchronous. A peculiarity was observed before the fusion of flagella, i.e., the attachment zones joined as 2 pairs by an electron-dense bridge. The mature spermatozoon is characterized by 2 axonemes, cortical microtubules, a nucleus, 2 mitochondria, external ornamentation, and spinelike bodies. At the posterior end of flagella, the spermatozoon is also characterized by the presence of a central element of the axoneme and without the 9 microtubule doublets. These results were compared with those of the o...
Yann Quilichini - One of the best experts on this subject based on the ideXlab platform.
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Ultrastructural study of vitellogenesis and oogenesis of Metadena depressa (Stossich, 1883) Linton, 1910 (Digenea, Cryptogonimidae), Intestinal Parasite of Dentex dentex (Pisces, Teleostei).
Comptes Rendus Biologies, 2012Co-Authors: Samuel Greani, Yann Quilichini, Josephine Foata, Zdzisław Swiderski, Bernard MarchandAbstract:The ultrastructural organization of the female reproductive system of Metadena depressa, digenean Intestinal Parasite of Sparidae (Dentex dentex), was investigated by electron microscopy. The vitellogenesis is divided into four stages: stage I, vitellocytes have a cytoplasm mainly filled with ribosomes and few mitochondria; stage II, beginning of the synthetic activity; stage III, active shell globule clusters synthesis; stage IV, mature vitellocytes are filled with shell globule clusters and generally contain several large lipid droplets. Glycogen granules are grouped at the periphery of the cell. The three stages of the oogenesis process take place in the ovary: stage I, oogonia are undifferentiated small cells located at the periphery of the organ; stage II, primary oocytes possess a higher nucleo-cytoplasmic ratio and a nucleus with a nucleolus and synaptonemal complexes indicating the zygotene-pachytene stage of the first meiotic division; stage III, mature oocytes are located in the proximal region of the organ and possess a cytoplasmic chromatoid body and cortical granules in a monolayer close to the periphery of the cell.
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ultrastructural study of vitellogenesis of aphallus tubarium rudolphi 1819 poche 1926 digenea cryptogonimidae an Intestinal Parasite of dentex dentex pisces teleostei
Journal of Parasitology, 2012Co-Authors: Samuel Greani, Yann Quilichini, Josephine Foata, Bernard MarchandAbstract:Abstract: Vitellogenesis of Aphallus tubarium, an Intestinal Parasite of Sparidae (Dentex dentex), was studied by transmission electron microscopy. The ultrastructural features allowed us to distinguish 4 stages in the vitellogenesis process. In stage 1, vitellocytes have a cytoplasm mainly filled with ribosomes, but few mitochondria. In stage 2, there is an increase in amount of endoplasmic reticulum and few Golgi complexes. There is production of shell globules that coalesce into clusters in stage 3; some glycogen particles are observed via the Thiery method. Finally, in stage 4, mature vitellocytes are filled with shell globule clusters and generally contain a large lipid droplet. Glycogen particles are grouped at the periphery of the cell.
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Ultrastructural study of vitellogenesis of Aphallus tubarium (Rudolphi, 1819) Poche, 1926 (Digenea: Cryptogonimidae), an Intestinal Parasite of Dentex dentex (Pisces: Teleostei).
J Parasitol, 2012Co-Authors: Samuel Greani, Yann Quilichini, Josephine Foata, Bernard MarchandAbstract:Vitellogenesis of Aphallus tubarium, an Intestinal Parasite of Sparidae (Dentex dentex ), was studied by transmission electron microscopy. The ultrastructural features allowed us to distinguish 4 stages in the vitellogenesis process. In stage 1, vitellocytes have a cytoplasm mainly filled with ribosomes, but few mitochondria. In stage 2, there is an increase in amount of endoplasmic reticulum and few Golgi complexes. There is production of shell globules that coalesce into clusters in stage 3; some glycogen particles are observed via the Thiéry method. Finally, in stage 4, mature vitellocytes are filled with shell globule clusters and generally contain a large lipid droplet. Glycogen particles are grouped at the periphery of the cell.
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spermatozoon ultrastructure of gyliauchen sp digenea gyliauchenidae an Intestinal Parasite of siganus fuscescens pisces teleostei
The Biological Bulletin, 2011Co-Authors: Yann Quilichini, Josephine Foata, Jean-lou Justine, Rodney A Bray, Bernard MarchandAbstract:The ultrastructure of the mature spermatozoon of Gyliauchen sp., a Parasite of the dusky rabbitfish Siganus fuscescens, was studied by transmission electron microscopy. The spermatozoon possesses two axonemes of the 9+“1” pattern of Trepaxonemata, four attachment zones, one mitochondrion, a nucleus, cortical microtubules, external ornamentation of the plasma membrane, and spine-like bodies. The main characteristics of this spermatozoon are the presence of one mitochondrion, spine-like bodies not associated with the external ornamentation, and a posterior extremity of type 3 that is characterized by the following sequence: posterior extremity of the nucleus then posterior extremity of the second axoneme. Numerous other ultrastructural features are also discussed and compared to the digenean spermatology literature. This is the first study of a member of the Gyliauchenidae and the fourth within the Lepocreadioidea. The results show that many ultrastructural characters are variable within this superfamily an...
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spermiogenesis and spermatozoon ultrastructure of nicolla wisniewskii digenea opecoelidae an Intestinal Parasite of brown trout salmo trutta pisces teleostei
Journal of Parasitology, 2007Co-Authors: Yann Quilichini, Josephine Foata, Antoine Orsini, Bernard MarchandAbstract:Spermiogenesis and ultrastructure of spermatozoon of Nicolla wisniewskii (Digenea, Opecoelidae), an Intestinal Parasite of Salmo trutta, were studied by electron microscopy. Spermiogenesis follows the general pattern found in the Digenea. It begins with the formation of a differentiation zone, including striated rootlets associated with 2 centrioles and an intercentriolar body. The flagella undergo a rotation of greater than 90°. Then, their fusion with the median cytoplasmic process is proximodistal and asynchronous. A peculiarity was observed before the fusion of flagella, i.e., the attachment zones joined as 2 pairs by an electron-dense bridge. The mature spermatozoon is characterized by 2 axonemes, cortical microtubules, a nucleus, 2 mitochondria, external ornamentation, and spinelike bodies. At the posterior end of flagella, the spermatozoon is also characterized by the presence of a central element of the axoneme and without the 9 microtubule doublets. These results were compared with those of the o...
Christian Schindler - One of the best experts on this subject based on the ideXlab platform.
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Intestinal Parasite infections and associated risk factors among schoolchildren in dolakha and ramechhap districts nepal a cross sectional study
Parasites & Vectors, 2018Co-Authors: Akina Shrestha, Christian Schindler, Peter Odermatt, Jana Gerold, Severine ErismannAbstract:Infections with soil-transmitted helminths and pathogenic Intestinal protozoa pose a considerable public health burden, particularly in low- and middle-income countries, including Nepal. We assessed the extent of Intestinal Parasite infections among schoolchildren in two districts of Nepal and determined underlying risk factors. A cross-sectional survey was conducted between March and May 2015 in the districts of Dolakha and Ramechhap, Nepal. A total of 708 children, aged 8–16 years from 16 purposively selected schools, were enrolled. Each child provided a single stool sample that was subjected to a suite of copro-microscopic diagnoses for Intestinal protozoa and helminths. Drinking water samples from different sources at schools (n = 29), community places (n = 43) and households (n = 562) were analysed for contamination with thermotolerant coliforms (TTC). A questionnaire was administered to determine individual- and household-level risk factors of Intestinal Parasite infections. Self-reported symptoms were assessed and a clinical examination was undertaken by a physician. Haemoglobin was measured and used as a proxy for anaemia. Mixed logistic regression models were applied to investigate associations. The overall prevalence of Intestinal Parasite infections was 39.7%. Trichuris trichiura (30.9%), Giardia Intestinalis (30.5%) and hookworm (30.2%) were the predominant Intestinal Parasite infections. Children from households lacking soap for handwashing were at higher odds of Intestinal Parasite infections than children who had soap [adjusted odds ratio (aOR) 1.81; 95% confidence interval (CI): 1.13–2.89; P = 0.01]. Children from households without freely roaming domestic animals showed lower odds of G. Intestinalis compared to children from households with freely roaming animals (aOR 0.52; 95% CI: 0.33–0.83; P = 0.01). One out of three (31.0%) children suffered from fever and 22.4% had watery diarrhoea within a two-week recall period. Anaemia was diagnosed in 23.6% of the children. Water contamination with TTC showed no clear association with Intestinal Parasite infection. Intestinal Parasites are common among schoolchildren in the two surveyed districts of Nepal. An important risk factor was lack of soap for handwashing. Our findings call for efforts to control Intestinal Parasite infection and emphasis should be placed on improvements in water, sanitation and hygiene interventions. ISRCTN17968589 (date assigned: 17 July 2015).
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Intestinal Parasite infections and associated risk factors in communities exposed to wastewater in urban and peri urban transition zones in hanoi vietnam
Parasites & Vectors, 2016Co-Authors: Christian Schindler, Samuel Fuhrimann, Mirko S Winkler, Phuc Phamduc, Dung Dotrung, Jurg UtzingerAbstract:Background Infections with Intestinal Parasites (helminths and Intestinal protozoa) are endemic in Southeast Asia and inappropriate management and reuse of wastewater might exacerbate the risk of human infections. In rapidly growing urban settings, little is known about the extent of Intestinal Parasite infections. We assessed the point-prevalence and risk factors of Intestinal Parasite infections in population groups differently exposed to wastewater in urban and peri-urban transition zones in Hanoi, the capital of Vietnam.
Josephine Foata - One of the best experts on this subject based on the ideXlab platform.
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Ultrastructural study of vitellogenesis and oogenesis of Metadena depressa (Stossich, 1883) Linton, 1910 (Digenea, Cryptogonimidae), Intestinal Parasite of Dentex dentex (Pisces, Teleostei).
Comptes Rendus Biologies, 2012Co-Authors: Samuel Greani, Yann Quilichini, Josephine Foata, Zdzisław Swiderski, Bernard MarchandAbstract:The ultrastructural organization of the female reproductive system of Metadena depressa, digenean Intestinal Parasite of Sparidae (Dentex dentex), was investigated by electron microscopy. The vitellogenesis is divided into four stages: stage I, vitellocytes have a cytoplasm mainly filled with ribosomes and few mitochondria; stage II, beginning of the synthetic activity; stage III, active shell globule clusters synthesis; stage IV, mature vitellocytes are filled with shell globule clusters and generally contain several large lipid droplets. Glycogen granules are grouped at the periphery of the cell. The three stages of the oogenesis process take place in the ovary: stage I, oogonia are undifferentiated small cells located at the periphery of the organ; stage II, primary oocytes possess a higher nucleo-cytoplasmic ratio and a nucleus with a nucleolus and synaptonemal complexes indicating the zygotene-pachytene stage of the first meiotic division; stage III, mature oocytes are located in the proximal region of the organ and possess a cytoplasmic chromatoid body and cortical granules in a monolayer close to the periphery of the cell.
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ultrastructural study of vitellogenesis of aphallus tubarium rudolphi 1819 poche 1926 digenea cryptogonimidae an Intestinal Parasite of dentex dentex pisces teleostei
Journal of Parasitology, 2012Co-Authors: Samuel Greani, Yann Quilichini, Josephine Foata, Bernard MarchandAbstract:Abstract: Vitellogenesis of Aphallus tubarium, an Intestinal Parasite of Sparidae (Dentex dentex), was studied by transmission electron microscopy. The ultrastructural features allowed us to distinguish 4 stages in the vitellogenesis process. In stage 1, vitellocytes have a cytoplasm mainly filled with ribosomes, but few mitochondria. In stage 2, there is an increase in amount of endoplasmic reticulum and few Golgi complexes. There is production of shell globules that coalesce into clusters in stage 3; some glycogen particles are observed via the Thiery method. Finally, in stage 4, mature vitellocytes are filled with shell globule clusters and generally contain a large lipid droplet. Glycogen particles are grouped at the periphery of the cell.
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Ultrastructural study of vitellogenesis of Aphallus tubarium (Rudolphi, 1819) Poche, 1926 (Digenea: Cryptogonimidae), an Intestinal Parasite of Dentex dentex (Pisces: Teleostei).
J Parasitol, 2012Co-Authors: Samuel Greani, Yann Quilichini, Josephine Foata, Bernard MarchandAbstract:Vitellogenesis of Aphallus tubarium, an Intestinal Parasite of Sparidae (Dentex dentex ), was studied by transmission electron microscopy. The ultrastructural features allowed us to distinguish 4 stages in the vitellogenesis process. In stage 1, vitellocytes have a cytoplasm mainly filled with ribosomes, but few mitochondria. In stage 2, there is an increase in amount of endoplasmic reticulum and few Golgi complexes. There is production of shell globules that coalesce into clusters in stage 3; some glycogen particles are observed via the Thiéry method. Finally, in stage 4, mature vitellocytes are filled with shell globule clusters and generally contain a large lipid droplet. Glycogen particles are grouped at the periphery of the cell.
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spermatozoon ultrastructure of gyliauchen sp digenea gyliauchenidae an Intestinal Parasite of siganus fuscescens pisces teleostei
The Biological Bulletin, 2011Co-Authors: Yann Quilichini, Josephine Foata, Jean-lou Justine, Rodney A Bray, Bernard MarchandAbstract:The ultrastructure of the mature spermatozoon of Gyliauchen sp., a Parasite of the dusky rabbitfish Siganus fuscescens, was studied by transmission electron microscopy. The spermatozoon possesses two axonemes of the 9+“1” pattern of Trepaxonemata, four attachment zones, one mitochondrion, a nucleus, cortical microtubules, external ornamentation of the plasma membrane, and spine-like bodies. The main characteristics of this spermatozoon are the presence of one mitochondrion, spine-like bodies not associated with the external ornamentation, and a posterior extremity of type 3 that is characterized by the following sequence: posterior extremity of the nucleus then posterior extremity of the second axoneme. Numerous other ultrastructural features are also discussed and compared to the digenean spermatology literature. This is the first study of a member of the Gyliauchenidae and the fourth within the Lepocreadioidea. The results show that many ultrastructural characters are variable within this superfamily an...
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spermiogenesis and spermatozoon ultrastructure of nicolla wisniewskii digenea opecoelidae an Intestinal Parasite of brown trout salmo trutta pisces teleostei
Journal of Parasitology, 2007Co-Authors: Yann Quilichini, Josephine Foata, Antoine Orsini, Bernard MarchandAbstract:Spermiogenesis and ultrastructure of spermatozoon of Nicolla wisniewskii (Digenea, Opecoelidae), an Intestinal Parasite of Salmo trutta, were studied by electron microscopy. Spermiogenesis follows the general pattern found in the Digenea. It begins with the formation of a differentiation zone, including striated rootlets associated with 2 centrioles and an intercentriolar body. The flagella undergo a rotation of greater than 90°. Then, their fusion with the median cytoplasmic process is proximodistal and asynchronous. A peculiarity was observed before the fusion of flagella, i.e., the attachment zones joined as 2 pairs by an electron-dense bridge. The mature spermatozoon is characterized by 2 axonemes, cortical microtubules, a nucleus, 2 mitochondria, external ornamentation, and spinelike bodies. At the posterior end of flagella, the spermatozoon is also characterized by the presence of a central element of the axoneme and without the 9 microtubule doublets. These results were compared with those of the o...
Jurg Utzinger - One of the best experts on this subject based on the ideXlab platform.
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Intestinal Parasite infections and associated risk factors in communities exposed to wastewater in urban and peri urban transition zones in hanoi vietnam
Parasites & Vectors, 2016Co-Authors: Christian Schindler, Samuel Fuhrimann, Mirko S Winkler, Phuc Phamduc, Dung Dotrung, Jurg UtzingerAbstract:Background Infections with Intestinal Parasites (helminths and Intestinal protozoa) are endemic in Southeast Asia and inappropriate management and reuse of wastewater might exacerbate the risk of human infections. In rapidly growing urban settings, little is known about the extent of Intestinal Parasite infections. We assessed the point-prevalence and risk factors of Intestinal Parasite infections in population groups differently exposed to wastewater in urban and peri-urban transition zones in Hanoi, the capital of Vietnam.
