pH-responsive hydrogels to protect IgY from gastric conditions: in vitro evaluation.

Oral administration of specific egg yolk immunoglobulin (IgY) is effective against a number of gastrointestinal pathogens. However, the activity of orally administered IgY is reduced rapidly, since IgY is sensitive to pepsin and low pH. In this study, hydrogels containing acrylamide and acrylic acid were synthesized and used to encapsulate IgY. The capacity of these structures to load, protect and release IgY and the interaction between IgY and hydrogels by FTIR spectroscopy were studied. The particle size and swelling percentage of hydrogels were highly dependent on the pH of the buffer solution. As expected, pH-sensitive hydrogels had a high IgY loading percentage (99.2 ± 12.9 mg IgY/mg hydrogel) at pH 7.4. It means that each gel piece incorporated approximately 8.4 ± 1.1 mg IgY. The results showed that the hydrogels could efficiently incorporate IgY and retain it inside the polymer network at pH <2.2. However, IgY was slowly released at basic pH and a high percentage remained inside. The IR spectra show that IgY interacts with the hydrogel in its network with extended hydrogen bonds. The present study demonstrates that hydrogels particles can efficiently incorporate the IgY but cannot show a controlled and sustained release of IgY in simulated intestinal fluid probably due to hydrophobic interactions with the polymer network. The stability of IgY in simulated gastric fluid was greatly improved by encapsulation in hydrogels. This approach provides information about a novelty method for delivery of IgY for the prevention and control of enteric diseases.

Immunohistochemical distribution of early pregnancy factor in ovary, oviduct and placenta of pregnant gilts.

Early pregnancy factor (EPF) is an immunosuppressant that promotes maternal immune system tolerance of the allogenic fetus. Little is known about localization of this factor in different tissues and nothing has been reported about localization in swine reproductive and placental tissues. We determined the concentration of EPF in serum of gilts and porcine placenta conditioned medium (PPCM). We also analyzed the expression of EPF in different reproductive tissues of pregnant gilts at 10, 30, 60 and 90 days of pregnancy. EPF concentration in serum and PPCM was determined by western blot and densitometry. EPF expression in reproductive tissue was assessed by immunohistochemistry. The highest concentration of EPF was observed at 30 days in serum and PPCM; the concentration was higher in PPCM than in serum at the stages we evaluated. All reproductive tissues from the gestational stages analyzed showed specific labeling of EPF, but this labeling did not appear in non-pregnant gilts. At 30 days pregnancy, the EPF expression in the ovary was predominantly in follicular lutein cells, probably owing to its function as a luteotrophic factor. In the oviduct, EPF was expressed in unciliated secretory epithelial cells and in the cilia of ciliated cells. In the placenta, EPF was expressed in the fetal portion (mesoderm chorioallantois and epithelium of endoderm). EPF acts as an autocrine and paracrine growth factor for the trophoblast during the peri-implantation period.

A review of physical and cognitive interventions in aging.

Maintaining a healthy brain is a critical factor for the quality of life of elderly individuals and the preservation of their independence. Challenging aging brains through cognitive training and physical exercises has shown to be effective against age-related cognitive decline and disease. But how effective are such training interventions? What is the optimal combination/strategy? Is there enough evidence from neuropsychological observations, animal studies, as well as, structural and functional neuroimaging investigations to interpret the underlying neurobiological mechanisms responsible for the observed neuroplasticity of the aging brain? This piece of work summarizes recent findings toward these questions, but also highlights the role of functional brain connectivity work, an emerging discipline for future research in healthy aging and the study of the underlying mechanisms across the life span. The ultimate aim is to conclude on recommended multimodal training, in light of contemporary trends in the design of exergaming interventions. The latter issue is discussed in conjunction with building up neuroscientific knowledge and envisaged future research challenges in mapping, understanding and training the aging brain.

Stroop interference is affected in inhibition of return.

In previous research, we have shown that the processing of targets that are presented to locations subject to inhibition of return (IOR) is affected by an inhibitory tagging mechanism. This mechanism acts by disconnecting activated representations of stimuli at inhibited locations from their associated responses. In two experiments, we assessed whether this inhibitory tagging mechanism of visual attention is also applied to task-irrelevant but prepotent dimensions of target stimuli, such as words in the Stroop task. To test this hypothesis, we examined the Stroop effect in an IOR procedure. The results showed that (1) IOR can be found in a color discrimination task, (2) the Stroop interference was reduced (Experiment 1) or eliminated (Experiment 2) when stimuli appeared at cued locations, as compared with cases in which they were presented at uncued locations, and (3) the effect of inhibitory tagging was limited to the shortest stimulus onset asynchrony value, replicating previous findings. These results agree with the idea that inhibitory tagging, occurring in IOR, affects the efficiency with which color words compete for responses in Stroop-like situations.

Descripción histológica de la substancia cortical dorsal en la parte media de la diáfisis del metacarpiano III en yegua mestiza / Histological description of the dorsal cortical bone in the midle diaphysis of the metacarpial III in the mixed mare

El hueso es el unicó tejido capaz de adaptarse estructural y geométricamente ante presiones impuestas sobre él. Durante la vida, el hueso es afectado por procesos externos e internos. Los externos producen cambios en sus medidas y forma. Los internos remodelan su arquitectura interna. Además, los huesos son afectados por factores que incluyen edad, sexo, especie, origen y contenido de minerales. Las variaciones estructurales en la organización microscópica del tejido óseo ocurren de manera constante y consistente mediante el crecimiento y la remodelación por parte de cada especie animal. El objetivo del presente trabajo fue estudiar la estructura microscópica inorgánica del cuadrante dorsal del metacarpiano III en la parte media de la diáfisis en distintos grupos etarios. Se estudió la substancia cortical dorsal de los huesos metarcapianos III izquierdos provenientes de 30 yeguas mestizas, con edades entre 2 y 5 años. Extraídos los huesos se los liberó de los tejidos blandos. El cuadrante dorsal fue muestreado, en la parte media de la diáfisis. Posteriormente, se realizó el pulido en forma manual. Las muestras fueron observadas al microscopio de luz polarizada. Se observaron diferencias histológica en los diferentes grupos etarios. Se concluyó que se producen variaciones microscópicas de la subtancia cortical dorsal del metarcapiano III en la parte media de la diáfisis, en el transcurso de 4 años

Inhibitory tagging in inhibition of return is affected in schizophrenia: evidence from the stroop task.

L. J. Fuentes, A. B. Vivas, and G. W. Humphreys (1999b) showed that stimulus processing is affected when stimuli are presented to locations subject to inhibition of return. They argued that activated representations of stimuli presented at inhibited locations are disconnected from their associated responses through an "inhibitory tagging" mechanism occurring in inhibition of return. In the present research, the authors asked whether such a mechanism is affected in people with schizophrenia. Healthy adults and patients with schizophrenia performed a Stroop task in an inhibition of return paradigm. Healthy adults showed a reduction in the Stroop interference when stimuli were presented at inhibited locations, a result that agrees with the inhibitory tagging mechanism hypothesis and replicates previous findings. However, patients with schizophrenia did not show such a reduction, a result suggesting that they have a deficit in inhibitory processing occurring in inhibition of return.

Inhibitory processing in visuospatial attention in healthy adults and schizophrenic patients.

This study assessed visuospatial attention in healthy adults and medicated schizophrenic patients. Participants performed a visual orientation task in which a peripheral cue was followed. at different intervals, by a target presented either at valid or invalid locations. When the long stimulus onset asynchrony (SOA) was used, participants were presented with either a single peripheral cue (single-cue condition) or two cues, the peripheral cue followed by a central cue (the double-cue condition). Healthy adults showed marginal facilitation effects with the short SOA and similar inhibition of return effects with the long SOA in both single-cue and double-cue conditions. Schizophrenic individuals showed a big facilitation effect with the short SOA and normal inhibition of return with the long SOA in both cue conditions. Results with the short SOA replicated previous findings (Huey, E.D., Wexler, B.E., 1994. Schizophrenia Research 14, 57-63) but, in contrast, we did not observe blunted inhibition of return with the long SOA. An inspection of the differences in the procedures used in both studies may help both to account for the discrepancies and to reveal what processes involved in visuospatial attention are affected in schizophrenia.

[Seasonal changes in the female reproductive apparatus of Lepus europaeus (P) in a population from the rural area of Rio Cuarto (Cordoba-Argentina)]. / Variaciones estacionales del aparato reproductor hembra de Lepus europaeus (P) en una poblacion del area rural de Rio Cuarto (Cordoba-Argentina).

In this paper, the reproductive cycle of the European hare, Lepus europaeus, was studied during a complete annual period in females of a population from the southern region of the province of Cordoba. The animals were captured monthly. Age, corporal and ovarian weights were determined, and the ovaries were fixed in Bouin and processed by current histological techniques. During the period from July to February, the mean corporal weight was 3.70 kg +/- 0.15. The ovaries showed follicles in different developmental stages, corpora lutea and interstitial gland. Embryos were frequently found in the uterus. From March to June, on the other hand, mean corporal weigth was 3.16 kg +/- 0.11. The ovaries presented developing follicles, interstitial gland and corpora albicans, and no corpora lutea were found. From these results, it can be seen that the reproductive cycle is composed of two well-defined periods: I) Reproductive period, extending from July to February, and II) Non-reproductive period, form March to June. The results are compared with those obtained by other authors on other hare populations, specially on populations from the southern region of Argentina (Bariloche), taking into account regional environmental characteristics.

Human placenta conditioned medium as a source of lymphocyte blastogenesis in vitro.

The purpose of this work was to obtain placental extracts with the capacity of producing lymphocyte blastogenesis. Placental homogenates were incubated at 37 degrees C in McCoy's 5A supplemented with 5% fetal bovine serum and 25 mM Hepes. After a 6-day incubation period, the cultures were harvested and the sterility and cellular viability were controlled. The supernatant was centrifuged at 22,000g at 4 degrees C for 30 minutes. Sterilization was achieved by filtration (0.22 microns). This medium was denominated human placenta conditioned medium (HPCM-1). The other half of the original placenta was processed by the Burgess method and the extracts thus obtained were denominated HPCM-2. The activity of the extracts thus obtained was tested in peripheral lymphocyte cultures from women after the third pregnancy; 5, 10 and 20% HPCM-1 or HPCM-2 was added to these cultures and the index of lymphocyte blast transformation (ILBT) was determined. The highest stimulation occurred at 10% HPCM. The ILBT obtained with HPCM-1 at 10% was more constant than that obtained with HPCM-2 at the same concentration. In conclusion, it can be assumed that this methodology is appropriate to obtain conditioned media from human placenta with good blastogenic activity on peripheral lymphocytes in vitro.

[Serum and hypophyseal profiles of alpha-melanotropin and prolactin during the reproductive cycle of Leptodactylus ocellatus]. / Perfiles séricos e hipofisarios de alpha-melanotrofina y prolactina durante el ciclo reproductor de Leptodactylus Ocellatus.

In this work, the seric and hypophysial concentrations of the hormones alpha-melantopin and prolactin of male specimens of Leptodactylus ocellatus from the province of Cordoba are studied during a complete annual period. This amphibian presents a continuous reproductive cycle with a wave of greater spermatogenic activity in early summer months (December-January). The results corresponding to hormones show a very similar pattern: both present their maximal seric value in the December-January period, coincidently with the greatest spermatogenic wave. Maximal hypophysial values precede seric concentration maximum by two months. Although the influence of these hormones on amphibian spermatogenesis is not well understood, the observations here described would indicate that alpha-melanotropin as well as prolactin could play a role in the spermatogenic process in Leptodactylus ocellatus.

Perfiles séricos e hipofisarios de alpha-melanotrofina y prolactina durante el ciclo reproductor de Leptodactylus Ocellatus. / [Serum and hypophyseal profiles of alpha-melanotropin and prolactin during the reproductive cycle of Leptodactylus ocellatus]

In this work, the seric and hypophysial concentrations of the hormones alpha-melantopin and prolactin of male specimens of Leptodactylus ocellatus from the province of Cordoba are studied during a complete annual period. This amphibian presents a continuous reproductive cycle with a wave of greater spermatogenic activity in early summer months (December-January). The results corresponding to hormones show a very similar pattern: both present their maximal seric value in the December-January period, coincidently with the greatest spermatogenic wave. Maximal hypophysial values precede seric concentration maximum by two months. Although the influence of these hormones on amphibian spermatogenesis is not well understood, the observations here described would indicate that alpha-melanotropin as well as prolactin could play a role in the spermatogenic process in Leptodactylus ocellatus.

[Evaluation of the method for early pregnancy factor detection (EPF) in swine. Significance in early pregnancy diagnosis]. / Evaluación del método de detección del factor precoz de preñez (EPF) en cerdos. Importancia en el diagnóstico temprano de gestación.

Early pregnancy factor (EPF) is a protein detected in the serum of pregnant females in most mammals, before implantation of the embryo; its activity is detected by the rosette inhibition test (RIT). After preincubation of lymphocytes in serum of non-pregnant pigs, the mean titre of RIT was 10.80 +/- 0.32. The upper limit of the 95% confidence interval was calculated to be 11.44. Therefore, all titres 12 were defined indicating the presence of EPF activity. The incubation of lymphocytes in serum of pregnancy caused a significant increase in the mean rosette inhibition titre, raising it to 19.88 +/- 1.13 (p < 0.001). False negative results were obtained for 10% of pregnant pigs. EPF positive activity was detected in only one non-pregnant pig (RIT = 20). This assay is not quantitative nor suitable for pregnancy diagnosis taking into account RIT values dispersion.

Evaluación del método de detección del factor precoz de preñez (EPF) en cerdos. Importancia en el diagnóstico temprano de gestación. / [Evaluation of the method for early pregnancy factor detection (EPF) in swine. Significance in early pregnancy diagnosis]

Early pregnancy factor (EPF) is a protein detected in the serum of pregnant females in most mammals, before implantation of the embryo; its activity is detected by the rosette inhibition test (RIT). After preincubation of lymphocytes in serum of non-pregnant pigs, the mean titre of RIT was 10.80 +/- 0.32. The upper limit of the 95

confidence interval was calculated to be 11.44. Therefore, all titres 12 were defined indicating the presence of EPF activity. The incubation of lymphocytes in serum of pregnancy caused a significant increase in the mean rosette inhibition titre, raising it to 19.88 +/- 1.13 (p < 0.001). False negative results were obtained for 10

of pregnant pigs. EPF positive activity was detected in only one non-pregnant pig (RIT = 20). This assay is not quantitative nor suitable for pregnancy diagnosis taking into account RIT values dispersion.

Evaluación del método de detección del factor precoz de preñez (EPF) en cerdos. Importancia en el diagnóstico temprano de gestación. / [Evaluation of the method for early pregnancy factor detection (EPF) in swine. Significance in early pregnancy diagnosis]

Early pregnancy factor (EPF) is a protein detected in the serum of pregnant females in most mammals, before implantation of the embryo; its activity is detected by the rosette inhibition test (RIT). After preincubation of lymphocytes in serum of non-pregnant pigs, the mean titre of RIT was 10.80 +/- 0.32. The upper limit of the 95

confidence interval was calculated to be 11.44. Therefore, all titres 12 were defined indicating the presence of EPF activity. The incubation of lymphocytes in serum of pregnancy caused a significant increase in the mean rosette inhibition titre, raising it to 19.88 +/- 1.13 (p < 0.001). False negative results were obtained for 10

of pregnant pigs. EPF positive activity was detected in only one non-pregnant pig (RIT = 20). This assay is not quantitative nor suitable for pregnancy diagnosis taking into account RIT values dispersion.