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Biomedical subjects

J Quilez

Publications and source records attributed to J Quilez.

10 recordsLinked to original sources
PubMed2004

Phenology of the tick, Ixodes ricinus, in its southern distribution range (central Spain).

The abundance, seasonal activity patterns and development rates of the tick Ixodes ricinus (L.) (Acari: Ixodidae), as well as microclimate features of the site of study, are described for a 9-year-long study (1994-2002) in north-central Spain. According to drag captures, larvae had a unimodal activity pattern, with a maximum observed around July-August, whereas nymphs displayed a bimodal pattern (May-June and August-September) with strong dominance of spring activity. An inversion of this pattern, with larger autumn peak, was observed in years with humid summers. Adults showed a small spring peak and a large autumn one. In the later years of the study, a small increase in the adult spring peak of activity was noticed, correlated with mild winters. Over the entire period of study, a clear increase in the total tick abundance was detected. Statistically significant differences between years were observed for some climate variables (saturation deficit, winter temperatures and number of days with temperatures above 6 degrees C), but a consistent and constant pattern of change was not observed in any climate variable. Temperature requirements for developing stages showed a sharp decrease in weeks 35-51 (eggs) and 38-50 (larvae and nymphs), a feature attributed to the presence of the morphogenetic diapause, beginning around September. Development rates obtained under quasi-natural conditions were almost twice those reported for other sites, suggesting an adaptation of this local, largely isolated I. ricinus population. According to drag captures and field-obtained development rates, interchange of nymphs between the two cohorts is common in this site, and seems to be influenced by the winter temperature and the date of larval engorgement.

Animals↗
PubMed2001

A method for the sequential study of eimerian chromosomes by light and electron microscopy.

In the present study, the authors describe a simple method to isolate chromosomes from eimerian oocysts and to submit them to sequential study by light and electron microscopy. This method includes a reliable and reproducible technique for transferring eimerian chromosomes from slides to grid that fulfills the essential requirements for generalized use in cytogenetics. In addition, this method overcomes the difficulty of the resistance of protozoan oocysts to disruption and permits the release of intact meiotic chromosomes. The observation by the authors of synaptonemal complexes in meiotic chromosomes of different Eimeria species by applying the above-mentioned method to oocysts revealed its importance to future applications.

Animals↗
PubMed2001

Eimeria tenella: hsp70 expression during sporogony.

There is an increasing interest in identifying the parasite components involved in the maturation, development, and infectivity of intracellular protozoan parasites. In the present study, a heat shock protein (hsp) of the family of 70 kDa hsp (hsp70), which play important roles in the stage conversion and virulence of these parasites, was examined. Whereas hsp70 expression has been examined in Eimeria tenella within host tissues, in the present study, oocysts of E. tenella were used to investigate the expression of hsp70 during sporulation without interference from the host; hsp70 expression during excystation was induced by incubating sporulated oocysts under various experimental conditions to produce the stimuli necessary for sporozoites to become active and to excyst in vitro. Hsp70 was detected by immunohistochemical techniques; quantitative flow cytometric analysis was also been carried out using specific monoclonal antibodies against hsp70. Hsp70 was expressed during sporulation but was not found in sporulated oocysts after the completion of sporulation. Oocysts re-expressed hsp70 when excystation was induced. The presence of hsp70 prior to infection may preadapt the parasite for additional stress in the host and may be involved in the formation of sporozoites.

Animals↗
PubMed1998

Expression and localization of an S100 protein-like molecule in Eimeria tenella.

We investigated the expression of a calcium-binding protein, the S100 protein, in Eimeria tenella. Cecal paraffin sections from experimentally infected chickens were treated with anti-alpha-S100 (anti-alpha subunit of S100 protein) and anti-beta-S100 (anti-beta subunit of S100 protein) monoclonal antibodies and anti-S100 whole molecule polyclonal antibody. The avidin-biotin peroxidase method was used for immunocytochemical staining. Our results demonstrated a positive immunoreaction within the schizonts, macrogametes, and oocysts. These stages were all beta subunit and S100 whole-molecule positive. Immunoblot studies of the total proteins of E. tenella merozoites and sporozoites of the original strain and 2 precocious lines have demonstrated that precocious attenuation produced different S100 protein isotypes.

Animals↗
PubMed1996

Identification of a fibronectin-like molecule on the surface of Leishmania amastigotes.

The major surface glycoprotein of Leishmania gp63, a fibronectin-like molecule, plays a key role in parasite-macrophage interaction. In this article, we describe a cross-reactivity between an anti-fibronectin monoclonal antibody and the amastigote gp63 by means of immunoelectron microscopy and immunoblot. Immunoreactivity was found on the amastigote membrane and in the flagellar pocket. We suggest that gp63 may play a role in the protection and/or nutrition process of the parasite in the phagolysosomes of the macrophage.

Animals↗
PubMed1996

Cytochemical study of the germinal membrane of the Echinococcus granulosus cyst.

The present cytochemical study was undertaken to provide more information on the localization of enzymatic and glycoconjugates in the germinal membrane of the Echinococcus granulosus cyst. The distinctive distribution of binding sites for two lectins (peanut agglutinin and Dilochos biflorus agglutinin) in the germinal membrane are described. An investigation is made of the distribution and specific activity of adenosine triphosphatase, alkaline phosphatase and acid phosphatase. The results suggest that cells located in the deeper layer of the germinal membrane are intrinsic in the cellular differentiation process. The dissimilarities detected in both the enzymatic activity and the lectin-binding receptors could be associated with metacestode development or degeneration.

Acid Phosphatase↗
PubMed1996

Identification of a fibronectin-like molecule on Eimeria tenella.

The attachment of Eimeria tenella to its target cells as an obligatory intracellular pathogen is essential for the development of disease. Previous reports have established that other intracellular protozoa parasites have either fibronectin, an adhesion protein, or fibronectin receptors, both of which are involved in the interaction with the host cells. In this current research, studies have been undertaken to visualize a surface component that may be involved in the attachment of E. tenella to host cells. For this purpose, monoclonal antibodies, both anti-chicken and anti-human fibronectin, and also anti-chicken integrin were used. Our results show a fibronectin-like molecule with an apparent molecular weight of 110 kDa in mature schizonts and microgametes. Staining with serum directed against chicken integrin revealed immunoreactivity within mature schizonts. Both the fibronectin-like molecule and the integrin may play an important role in the parasite stage-cell interaction and the promotion of parasite uptake.

Animals↗
PubMed1995

Detection of Blastocystis sp. in pigs in Aragon (Spain).

Infection by Blastocystis sp. has been detected for the first time in pigs in Spain. Detection was carried out by the ethyl acetate-formalin concentration method and direct microscopy. Vacuolated cells of Blastocystis sp. were found in stool samples from 27 of 360 pigs examined (7.5%). The protozoan was present on nine of 17 pig farms studied (53%). Infected pigs ranged from 1 month old to adults, but the organism was most frequent in 1-2 month old (18.4%) and 2-6 month old pigs (15.4%). No correlation was found between Blastocystis sp. infection and occurrence of diarrhoea in pigs.

Age Factors↗