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Miquel J.,University of Barcelona | Torres J.,University of Barcelona | Foronda P.,Instituto Universitario Of Enfermedades Tropicales lud Publica Of Canarias | Feliu C.,University of Barcelona
Acta Zoologica

The spermiogenesis and the ultrastructural organization of the spermatozoon of the davaineid cestode Raillietina micracantha are described by means of transmission electron microscopy. Spermiogenesis begins with the formation of a zone of differentiation containing two centrioles. One of the centrioles develops a free flagellum that later fuses with a cytoplasmic extension. The nucleus migrates along the spermatid body after the proximodistal fusion of the flagellum and the cytoplasmic extension. During advanced stages of spermiogenesis a periaxonemal sheath and intracytoplasmic walls appear in the spermatids. Spermiogenesis finishes with the appearance of two helicoidal crested bodies at the base of spermatids and, finally, the narrowing of the ring of arched membranes detaches the fully formed spermatozoon. The mature spermatozoon of R. micracantha is a long and filiform cell, tapered at both ends, which lacks mitochondria. It exhibits two crested bodies of different lengths, one axoneme of the 9 + '1' pattern of trepaxonematan Platyhelminthes, twisted cortical microtubules, a periaxonemal sheath, intracytoplasmic walls, granules of glycogen and a spiralled nucleus. The anterior extremity of the spermatozoon is characterized by the presence of an electron-dense apical cone and two spiralled crested bodies while the posterior extremity of the male gamete exhibits only the axoneme and an electron-dense posterior tip. © 2009 The Authors. Journal compilation © 2009 The Royal Swedish Academy of Sciences. Source

Lo Presti M.S.,National University of Cordoba | Esteves B.H.,National University of Cordoba | Moya D.,National University of Cordoba | Bazan P.C.,National University of Cordoba | And 8 more authors.
Acta Tropica

We evaluated the presence and distribution of two Trypanosoma cruzi natural isolates in blood, heart, skeletal muscle, liver, and spleen tissues in the acute phase of the experimental infection (35 days postinfection) in order to determine if the populations present in blood were different to those found in the tissues of the same host. Thirty mice were infected with 50 forms of each isolate or with a combination of them. Presence and molecular characterization of the parasites in the host tissues were determined by specific PCR. Cardiac and skeletal muscle alterations were analyzed by histological studies. T. cruzi variability in the host tissues was analyzed through RFLP studies. Both isolates used consisted of a mixture of two T. cruzi lineages. Specific PCRs were positive for most of the samples from the 3 groups analyzed. Cardiac and skeletal muscle sections from the groups infected with one isolate presented mild to moderate inflammatory infiltrates; the group infected with both isolates showed severe inflammatory infiltrates and the presence of amastigote nests in both tissues. Different parasite populations were found in circulation and in the tissues from the same host. These results are important for patients with high probability of mixed infections in endemic areas and contribute to the knowledge of parasite/host interactions. © 2014 Elsevier B.V. Source

Fernandez-Lopez C.,CSIC - Biological Research Center | Lorenzo-Diaz F.,Instituto Universitario Of Enfermedades Tropicales lud Publica Of Canarias | Perez-Luque R.,Barcelona Institute for Research in Biomedicine | Perez-Luque R.,Institute Of Biologia Molecular Of Barcelona Ibmb Csic | And 8 more authors.

The MobM relaxase (494 amino acids) encoded by the promiscuous streptococcal plasmid pMV158 recognizes the plasmid origin of transfer, oriTpMV158, and converts supercoiled pMV158 DNA into relaxed molecules by cleavage of the phosphodiester bond of a specific dinucleotide within the sequence 5'-GTGTG/TT-3' ("/" being the nick site). After cleavage, the protein remains stably bound to the 5'-end of the nick site. Band-shift assays with single-stranded oligonucleotides and size-exclusion chromatography allowed us to show that MobM was able to generate specific complexes with one of the inverted repeats of the oriTpMV158, presumably extruded as stem-loop structure. A number of tests have been performed to attain a better characterization of the nicking activity of MobM and its linkage with its target DNA. The optimal pH for DNA relaxation was found to be 6.5. Upon nicking, gel retardation assays showed that MobM formed stable complexes with its target DNA. Moreover, MobM bound to relaxed pMV158 molecules were visualized by electron microscopy. The staphylococcal plasmids pUB110 and pE194, and the streptococcal plasmid pDL287 harbour putative oriTs and may encode Mob proteins homologous to MobM. The oriTpUB110, oriTpDL287, and oriTpE194 sequences share 100%, 70%, and 67% (in a 43-nucleotide stretch and allowing a 3-bp gap) identity to oriTpMV158, respectively. Nicking assays using supercoiled DNAs from pUB110, pDL287, and pE194 showed that MobM was able to relax, to differing degrees, all plasmid DNAs. Our results suggest that cross-recognition of heterologous oriTs by Mob proteins could play an important role in the plasmid spreading between bacteria. © 2013 Elsevier Inc. Source

Romay-Barja M.,Institute Salud Carlos III | Cano J.,London School of Hygiene and Tropical Medicine | Nseng G.,Ministerio de Salud y Bienestar Social | Santana-Morales M.A.,Red de Investigacion Colaborativa en Enfermedades Tropicales | And 4 more authors.
Malaria Journal

Background: Malaria remains a major cause of morbidity and mortality in children under 5 years of age in Equatorial Guinea. Early appropriate treatment can reduce progression of the illness to severe stages, thus reducing of mortality, morbidity and onward transmission. The factors that contribute to malaria treatment delay have not been studied previously in Equatorial Guinea. The objective of this study was to assess the determinants of delay in seeking malaria treatment for children in the Bata district, in mainland Equatorial Guinea. Methodology: A cross-sectional study was conducted in Bata district, in 2013, which involved 428 houses in 18 rural villages and 26 urban neighbourhoods. Household caregivers were identified in each house and asked about their knowledge of malaria and about the management of the last reported malaria episode in a child 15 years and younger under their care. Bivariate and multivariate statistical analyses were conducted to determine the relevance of socio-economic, geographical and behavioural factors on delays in care-seeking behaviour. Results: Nearly half of the children sought treatment at least 24 h after the onset of the symptoms. The median delay in seeking care was 2.8 days. Children from households with the highest socio-economic status were less likely to be delayed in seeking care than those from households with the lowest socio-economic status (OR 0.37, 95 % CI 0.19-0.72). Children that first received treatment at home, mainly paracetamol, were more than twice more likely to be delayed for seeking care, than children who did not first receive treatment at home (OR 2.36, 95 % CI 1.45-3.83). Children living in a distance >3 km from the nearest health facility were almost two times more likely to be delayed in seeking care than those living closer to a facility but with non significant association once adjusted for other variables (OR 1.75, 95 % CI 0.88-3.47). Conclusion: To decrease malaria morbidity and mortality in Bata district, efforts should be addressed to reduce household delays in seeking care. It is necessary to provide free access to effective malaria diagnosis and treatment, to reinforce malaria management at community level through community health workers and drug sellers and to increase awareness on the severity of malaria, the importance of early diagnosis and appropriate treatment. © 2016 Romay-Barja et al. Source

Romay-Barja M.,Institute Salud Carlos III | Jarrin I.,Institute Salud Carlos III | Nseng G.,Ministerio de Salud y Bienestar Social | Sagrado M.J.,Institute Salud Carlos III | And 7 more authors.

Background: Malaria remains a major cause of morbidity and mortality among children under five years old in Equatorial Guinea. However, little is known about the community management of malaria and treatment-seeking patterns. We aimed to assess symptoms of children with reported malaria and treatment-seeking behaviour of their caretakers in rural and urban areas in the Bata District. Methodology: A cross-sectional study was conducted in the district of Bata and 440 houses were selected from 18 rural villages and 26 urban neighbourhoods. Differences between rural and urban caregivers and children with reported malaria were assessed through the chi-squared test for independence of categorical variables and the t-Student or the non-parametric Mann-Whitney test for normally or not-normally distributed continuous variables, respectively. Results: Differences between rural and urban households were observed in caregiver treatment-seeking patterns. Fever was the main symptom associated with malaria in both areas. Malaria was treated first at home, particularly in rural areas. The second step was to seek treatment outside the home, mainly at hospital and Health Centre for rural households and at hospital and private clinic for urban ones. Artemether monotherapy was the antimalarial treatment prescribed most often. Households waited for more than 24 hours before seeking treatment outside and delays were longest in rural areas. The total cost of treatment was higher in urban than in rural areas in Bata. Conclusions: The delays in seeking treatment, the type of malaria therapy received and the cost of treatment are the principal problems found in Bata District. Important steps for reducing malaria morbidity and mortality in this area are to provide sufficient supplies of effective antimalarial drugs and to improve malaria treatment skills in households and in both public and private sectors. © 2015 Romay-Barja et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Source

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