Pilar García-Palencia - Academia.edu (original) (raw)

Papers by Pilar García-Palencia

Theriogenology, 2015

In Iberian pigs, a high conceptus loss occurs during the first 30 days of gestation. Although the... more In Iberian pigs, a high conceptus loss occurs during the first 30 days of gestation. Although the exact causes for these losses have not been determined to date, the importance of blood vessel development during early pregnancy has been noted. The aim of this study was to analyze the messenger RNA (mRNA) and protein expression of VEGF-rs (vascular endothelial growth factor, the VEGFR1, and the VEGFR2 receptor system) and elucidate a possible relationship with the conceptus status (healthy or arrested) on gestational Days (gd) 22 and 32. Both mRNA and protein expression for VEGF-rs molecules were consistently expressed in conceptuses and endometrium during the pregnancy period analyzed. In endometrium, a significant increase in VEGF mRNA and VEGFR2 mRNA expression in healthy sites was observed as pregnancy advances (P < 0.001 and P < 0.05, respectively), whereas VEGFR1 mRNA expression was maintained at a constant level. Interestingly, a significantly elevated VEGFR2 mRNA expres...

Cancer research, Jan 15, 2001

The cell cycle regulator p21 mediates the ability of the tumor suppressor p53 to arrest cellular ... more The cell cycle regulator p21 mediates the ability of the tumor suppressor p53 to arrest cellular proliferation. We have examined the involvement of p21 in tumor suppression by following a large cohort of p21-deficient mice for an extended period of time. We report that p21-deficient mice develop spontaneous tumors at an average age of 16 months, whereas wild-type mice are tumor-free beyond 2 years of age. The tumors arising in p21-null mice derive from a variety of cell types and include hematopoietic ( approximately 65% of the tumors), endothelial ( approximately 20%), and epithelial ( approximately 10%) tumors. We have also studied radiation-induced carcinogenesis to test whether, in this setting, p53 exerts its tumor suppressor activity mainly through apoptosis, rather than through p21-mediated cell-cycle arrest. Concurring with this, p21-deficient mice did not show increased susceptibility to radiation-induced carcinogenesis. On the contrary, they were protected relative to wild...

Cancer Research

MFA (“Me Falta el Aire” / I can’t breathe) is an application for teaching Respiratory Infectious ... more MFA (“Me Falta el Aire” / I can’t breathe) is an application for teaching Respiratory Infectious Diseases in Veterinary Science created by a multidisciplinary team of Art, Computer Science, and Veterinary teachers based on an artistic presentation of histological images through interactive web design. Understanding the development and evolution of histological lesions in infectious diseases is useful for understanding the natural history of the disease. Histological images have been selected to represent chronological events in the development of the disease according to scientific and technical criteria and have been worked on to reinforce their plastic and artistic presentation to evoke emotions. This application can be used to improve student skills to make accurate observations of pathological findings and foster active learning in teaching Infectious Diseases in Veterinary Science.

This article cites 49 articles, 24 of which you can access for free at:

Se ha realizado un estudio anatomopatologico del intestino en perros beagle infectados experiment... more Se ha realizado un estudio anatomopatologico del intestino en perros beagle infectados experimentalmente con leishmania infantum. Tres de estos animales (grupo a) fueron inoculados intraperitonealmente con 5 ml de material infectante que contenia 2x10 amastigotes; otros tres (grupo b), se inocularon intravenosamente, 5 ml. De material infectante a una concentracion de 5x10 amastigotes. Dos animales, utilizados como control, se les inoculo un homogeinizado de bazo de criseto sano. Los animales del grupo a se sacrificaron a los 109, 433 y 592 dias postinoculacion y a los del grupo b a los 109, 171 y 334 dias. Macroscopicamente, unicamente en las ultimas fases de la enfermedad, se afecto la mucosa intestinal. Histologicamente se observo un infiltrado inflamatorio constituido por linfocitos, principalmente de tipo t, celulas plasmaticas, macrofagos y celulas gigantes multinucleadas parasitadas, localizadas fundamentalmente en la mucosa. Con el transcurso de la enfermedad este se hizo ma...

The remodelling of flagella into attachment structures is a common and important event in the ins... more The remodelling of flagella into attachment structures is a common and important event in the insect stages of the trypanosomatid life cycle. Among their hymenopteran hosts,Lotmaria passimandCrithidia mellificaecan parasitizeApis mellifera, and as a result they might have a significant impact on honeybee health. However, there are details of their life cycle and the mechanisms underlying their pathogenicity in this host that remain unclear. Here we show that bothL. passimpromastigotes andC. mellificaechoanomastigotes differentiate into haptomonad stage covering the ileum and rectum of honeybees. These haptomonad cells remain attached to the host surface via zonular hemidesmosome-like structures, as revealed by Transmission Electron Microscopy. Hence, for the first time this work describes the haptomonad morphotype of these species and their hemidesmosome-like attachment inApis mellifera, a key trait exploited by other trypanosomatid species to proliferate in the insect host hindgut....

International Journal for Parasitology

The trypanosomatids Crithidia mellificae and Lotmaria passim are very prevalent in honey bee colo... more The trypanosomatids Crithidia mellificae and Lotmaria passim are very prevalent in honey bee colonies and potentially contribute to colony losses that currently represent a serious threat to honey bees. However, potential pathogenicity of these trypanosomatids remains unclear and since studies of infection are scarce, there is little information about the virulence of their different morphotypes. Hence, we first cultured C. mellificae and L. passim (ATCC reference strains) in six different culture media to analyse their growth rates and to obtain potentially infective morphotypes. Both C. mellificae and L. passim grew in five of the media tested, with the exception of M199. These trypanosomatids multiplied fastest in BHI medium, in which they reached a stationary phase after around 96 h of growth. Honey bees inoculated with either Crithidia or Lotmaria died faster than control bees and their mortality was highest when they were inoculated with 96 h cultured L. passim. Histological and Electron Microscopy analyses revealed flagellated morphotypes of Crithidia and Lotmaria in the lumen of the ileum, and adherent non-flagellated L. passim morphotypes covering the epithelium, although no lesions were evident. These data indicate that parasitic forms of these trypanosomatids obtained from the early stationary growth phase infect honey bees. Therefore, efficient infection can be achieved to study their intra-host development and to assess the potential pathogenicity of these trypanosomatids.

Veterinary Pathology

The microsporidia Nosema apis and Nosema ceranae are major honey bee pathogens that possess diffe... more The microsporidia Nosema apis and Nosema ceranae are major honey bee pathogens that possess different characteristics in terms of the signs they produce, as well as disease development and transmission. Although the ventricular epithelium is generally considered the target tissue, indirect observations led to speculation that N. ceranae may also target other structures, possibly explaining at least some of the differences between these 2 species. To investigate the tropism of Nosema for honey bee tissues, we performed controlled laboratory infections by orally administering doses of 50 000 or 100 000 fresh mature spores of either species. The fat body was isolated from the infected bees, as well as organs from the digestive (esophagus, ventriculus, ileum, rectum), excretory (Malpighian tubules), circulatory (aorta, heart), respiratory (thoracic tracheas), exocrine (hypopharyngeal, mandibular and labial, cephalic, thoracic salivary glands), and sensory/nervous (brain, eyes and associ...

Environmental microbiology, 2018

Nosema ceranae is a hot topic in honey bee health as reflected by numerous papers published every... more Nosema ceranae is a hot topic in honey bee health as reflected by numerous papers published every year. This review presents an update of the knowledge generated in the last 12 years in the field of N. ceranae research, addressing the routes of transmission, population structure and genetic diversity. This includes description of how the infection modifies the honey bee's metabolism, the immune response and other vital functions. The effects on individual honey bees will have a direct impact on the colony by leading to losses in the adult's population. The absence of clear clinical signs could keep the infection unnoticed by the beekeeper for long periods. The influence of the environmental conditions, beekeeping practices, bee genetics and the interaction with pesticides and other pathogens will have a direct influence on the prognosis of the disease. This review is approached from the point of view of the Mediterranean countries where the professional beekeeping has a high...

Journal of Comparative Pathology

Journal of Comparative Pathology, 2015

Veterinary Microbiology, 2013

The intestinal honey bee parasite Nosema ceranae (Microsporidia) is at the root of colony losses ... more The intestinal honey bee parasite Nosema ceranae (Microsporidia) is at the root of colony losses in some regions while in others its presence causes no direct mortality. This is the case for Spain and France, respectively. It is hypothesized that differences in honey bee responses to N. ceranae infection could be due to the degree of virulence of N. ceranae strains from different geographic origins. To test this hypothesis, we first performed a study to compare the genetic variability of an rDNA fragment that could reveal differences between two N. ceranae isolates, one from Spain and one from France. Then we compared the infection capacity of both isolates in Apis mellifera iberiensis, based on the anatomopathological lesions due to N. ceranae development in the honey bee midgut, N. ceranae spore-load in the midgut and the honey bee survival rate. Our results suggest that there is no specific genetic background of the two N. ceranae isolates, from Spain or France, used in this study. These results agree with the infection development, honey bee survival and spore-loads that were similar between honey bees infected with both N. ceranae isolates. Probably, differences in honey bee response to infection are more related to the degree of tolerance of honey bee subspecies or local hybrids to N. ceranae, or experimental conditions in the case of laboratory trials, than to differences between N. ceranae isolates. Further studies should be done to estimate the contribution of each of these factors on the response of the honey bees to infection.

Reproduction in Domestic Animals, 2011

The aim of the current study was to determine the possible effects of progestagen oestrous synchr... more The aim of the current study was to determine the possible effects of progestagen oestrous synchronization on vascular endothelial growth factor (VEGF) expression during sheep luteogenesis and the peri-implantation period and the relationship with luteal function. At days 9, 11, 13, 15, 17 and 21 of pregnancy, the ovaries from 30 progestagen treated and 30 ewes cycling after cloprostenol injection were evaluated by ultrasonography and, thereafter, collected and processed for immunohistochemical evaluation of VEGF; blood samples were drawn for evaluating plasma progesterone. The progestagen-treated group showed smaller corpora lutea than cloprostenol-treated and lower progesterone secretion. The expression of VEGF in the luteal cells increased with time in the cloprostenol group, but not in the progestagen-treated group, which even showed a decrease between days 11 and 13. In progestagen-treated sheep, VEGF expression in granulosa-derived parenchymal lobule capillaries was correlated with the size of the luteal tissue, larger corpora lutea had higher expression, and tended to have a higher progesterone secretion. In conclusion, the current study indicates the existence of deleterious effects from exogenous progestagen treatments on progesterone secretion from induced corpora lutea, which correlate with alterations in the expression of VEGF in the luteal tissue and, this, presumably in the processes of neoangiogenesis and luteogenesis.

Reproduction in Domestic Animals, 2012

The objective of this study was to investigate differences on the endometrial immunoexpression of... more The objective of this study was to investigate differences on the endometrial immunoexpression of type I IFN receptor subunit 1 (IFNAR1) and oxytocin receptor (OTR) during the time of maternal recognition of pregnancy in sheep, when oestrus is synchronized with either prostaglandin analogues (group PG) or conventional progestagens (group P). Plasma progesterone was measured from day 0 to 21 post-coitus (pc) (day 0 = day of oestrus). Immunohistochemistry was performed in samples of uterine horns from pregnant sheep on days 9pc, 13pc, 15pc, 17pc and 21pc to locate IFNAR1 and OTR expression in different endometrial compartments. Mean levels of plasma progesterone were different between treatments, obtaining higher levels in the PG group than in the P group (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05). Comparing days of pregnancy, IFNAR1 protein expression was different in the luminal epithelium (LE) (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05), while OTR was different in the LE and in the superficial glandular epithelium (SG) (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05). Temporal variation on the expression of both proteins from day 9pc to 21pc has been evidenced. IFNAR1 and OTR expression did not show significant differences between treatments. However, the response observed in the endometrium was highly inconsistent when prostaglandin analogues were used. Therefore, the protocol based on prostaglandin analogues still needs to be optimized before being considered as a better alternative to progestagens for oestrous synchronization in sheep.

Laboratory Investigation, 2011