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Biomedical subjects

J Arias

Publications and source records attributed to J Arias.

At least 19 recordsLinked to original sources
PubMed2006

The inflammatory response recapitulates phylogeny through trophic mechanisms to the injured tissue.

The post-traumatic local acute inflammatory response is described as a succession of three functional phases of possible trophic significance: 1. Nervous or immediate (ischemia-reperfusion); 2. Immune or intermediate (infiltration by inflammatory and bacterial cells) and 3. Endocrine or late (angiogenesis with regeneration and/or cicatrization). Each of these phases emphasizes the trophic role of the mechanisms in the damaged tissue. Hence, the nervous phase is predominated by nutrition by diffusion; in the immune phase trophism is mediated by inflammatory cells and bacteria and, finally, in the endocrine phase, the blood circulation and oxidative metabolism play the most significant nutritive role. Since these trophic mechanisms are of increasing complexity, progressing from anoxia to total specialization in the use of oxygen to obtain usable energy, it could be speculated that they represent the successive reappearance of the stages that take place during the evolution of life on Earth, from ancient times without oxygen. In this sense, the inflammatory response could recapitulate phylogeny through the successive expression of pathophysiologic mechanisms that have a trophic meaning to the injured tissue.

Animals↗
PubMed2005

Evaluation of two experimental models of hepatic encephalopathy in rats.

The serious neuropsychological repercussions of hepatic encephalopathy have led to the creation of several experimental models in order to better understand the pathogenesis of the disease. In the present investigation, two possible causes of hepatic encephalopathy, cholestasis and portal hypertension, were chosen to study the behavioral impairments caused by the disease using an object recognition task. This working memory test is based on a paradigm of spontaneous delayed non-matching to sample and was performed 60 days after surgery. Male Wistar rats (225-250 g) were divided into three groups: two experimental groups, microsurgical cholestasis (N = 20) and extrahepatic portal hypertension (N = 20), and a control group (N = 20). A mild alteration of the recognition memory occurred in rats with cholestasis compared to control rats and portal hypertensive rats. The latter group showed the poorest performance on the basis of the behavioral indexes tested. In particular, only the control group spent significantly more time exploring novel objects compared to familiar ones (P < 0.001). In addition, the portal hypertension group spent the shortest time exploring both the novel and familiar objects (P < 0.001). These results suggest that the existence of portosystemic collateral circulation per se may be responsible for subclinical encephalopathy.

Animals↗
PubMed2004

Portal hypertension: return to fetal life to re-attempt differentiation?

We speculate on the final meaning of the alterations that characterize portal hypertensive enteropathy. The similarity of these alterations with certain morphofunctional characteristics of prenatal splanchnic development makes it possible to hypothesize that the dedifferentiation with return to early stages of development could constitute a portal hypertension induced pathogenic mechanism.

Cell Differentiation↗
PubMed2004

Mapping of bovine ovulation rate QTL; an analytical approach for three generation pedigrees.

Interval mapping was conducted for ovulation rate quantitative trait loci (QTL) using data from two related families from the United States Department of Agriculture, US Meat Animal Research Center twinning cattle herd. Both families are extended, three generation pedigrees from which records of sons, daughters and granddaughters were analysed. Both a method of analysis and results from that analysis are reported herein. Results from one of the two families (839802) were previously reported, but reanalysis here including the second, related family (839803) and a revised statistical model lessens support for the previously reported QTL. Results from interval mapping provided evidence for QTL in regions corresponding to those previously suggested for chromosomes 7 (chromosome-wise P < 0.05) and 19 (chromosome-wise P < 0.01) in the 839802 family, although statistical significance was reduced. In contrast to the previous report, evidence for a chromosome 5 QTL in the same family was greatly reduced while support for a QTL on chromosome 10 increased (chromosome-wise P < 0.01). Analysis of data from the related 839803 family failed to replicate evidence of QTL observed on either chromosome 7 or chromosome 19 in the 839802 family.

Agriculture↗
PubMed2004

Posttraumatic inflammation is a complex response based on the pathological expression of the nervous, immune, and endocrine functional systems.

The successive phases that make up both the local and systemic posttraumatic acute inflammatory response could represent the expression of three concatenated pathological or "primitive" functional systems with trophic properties: the nervous, immune, and endocrine ones. The nervous functional system would play an important role in the phenomenon of ischemia-reperfusion, which would be represented by nutrition by diffusion that is either anaerobic (ischemia) or with defective use of oxygen (reperfusion) and, thus, with a limited energy requirement. The immune functional system would be represented by the infiltration of the tissues by inflammatory cells and bacteria, which would become mediators in providing nutrition to the injured tissues. Although the use of oxygen would still be defective, hypermetabolism and fever would occur. In these inflammatory response phases, the lymphatic is the most important circulation. The endocrine functional system would be the most specialized and would have high energy requirements because it would be represented by the blood capillary-mediated nutrition. Highly specialized epithelial cells would already possess a perfected oxidative metabolism. The successive expression of these three functional systems during embryonic development and also during the evolutionary development of our species could explain why the inflammatory response is a ubiquitous mechanism that is common to multiple diseases, because it is an integrator of the ontogeny and phylogeny.

Endocrine Glands↗
PubMed2003

Budesonide ameliorates early portal hypertension in the rat: possible antiexudative splanchnic action.

Major portal pressure increase occurs on the second day post-stenosing-ligation of the portal vein in the rat and it is associated with pancreatic edema, intraperitoneal free exudate, hypoalbuminemia and hypoproteinemia. All this suggests the development of a regional exudative inflammatory response. In order to verify this hypothesis the steroid budesonide, whose antiinflammatory activity could prevent these alterations, was administered to rats with prehepatic portal hypertension. Wistar male rats were divided into the following groups: Control rats that were administered saline solution (CS; n = 10), Control rats that were administered budesonide (36 mg/kg per day; CB; n = 10), triple stenosing ligation of portal vein (TSLP) with saline solution (n = 10) and triple stenosing ligation of portal vein with budesonide (36 mg/kg per day; n = 10). In rats with prehepatic portal hypertension at 48 h of postoperative evolution, budesonide decreases the incidence of pancreatic edema, of peritoneal free exudate, of mesenteric adenopathies and prevents hypoproteinemia, hypoalbuminemia and hyper-beta-globulinemia. Some of the macroscopic intra-abdominal alterations and some of the changes in the electrophoretic pattern found in portal hypertensive rats could have an inflammatory etiopathogeny because budesonide shows an effective prophylaxis.

Journal Article↗
PubMed2002

Altered proteinogram in short term portal vein stenosed rats.

The electrophoretic pattern of serum proteins has been studied in short-term prehepatic portal hypertensive rats since atrophy is produced in the liver, which is the main origin of most of these proteins, during this postoperative period. After 28 days of evolution, rats (n = 9) with triple stenosing ligated portal vein showed hypoalbuminemia, hypo-alpha-globulinemia, hyper-alpha2-globulinemia and hyper-gamma-globulinemia, the albumin/globulin ratio decreased with respect to the control animals (n = 8). These alterations are associated with hepatic atrophy, portosystemic and portohepatic (44.4%) collateral circulation. The proteinogram alterations found in rats with short-term prehepatic portal hypertension suggest that hepatic failure exists in spite of potential portohepatic revascularization which is frequently originated by the development of portohepatic collateral circulation.

Animals↗
PubMed2001

Kinetics and mechanisms of catalytic oxygen atom transfer with oxorhenium(V) oxazoline complexes.

The rhenium(V) monooxo complexes (hoz)2Re(O)Cl (1) and [(hoz)2Re(O)(OH2)][OTf] (2) have been synthesized and fully characterized (hoz = 2-(2'-hydroxyphenyl)-2-oxazoline). A single-crystal X-ray structure of 2 has been solved: space group = P1, a = 13.61(2) A, b = 14.76(2) A, c = 11.871(14) A, alpha = 93.69(4) degrees, beta = 99.43(4) degrees, gamma = 108.44(4) degrees, Z = 4; the structure was refined to final residuals R = 0.0455 and Rw = 0.1055. 1 and 2 catalyze oxygen atom transfer from aryl sulfoxides to alkyl sulfides and oxygen-scrambling between sulfoxides to yield sulfone and sulfide. Superior catalytic activity has been observed for 2 due to the availability of a coordination site on the rhenium. The active form of the catalyst is a dioxo rhenium(VII) intermediate, [Re(O)2(hoz)2]+ (3). In the presence of sulfide, 3 is rapidly reduced to [Re(O)(hoz)2]+ with sulfoxide as the sole organic product. The transition state is very sensitive to electronic influences. A Hammett correlation plot with para-substituted thioanisole derivatives gave a reaction constant rho of -4.6 +/- 0.4, in agreement with an electrophilic oxygen transfer from rhenium. The catalytic reaction features inhibition by sulfides at high concentrations. The equilibrium constants for sulfide binding to complex 2 (cause of inhibition), K2 (L x mol(-1)), were determined for a few sulfides: Me2S (22 +/- 3), Et2S (14 +/- 2), and tBu2S (8 +/- 2). Thermodynamic data, obtained from equilibrium measurements in solution, show that the S=O bond in alkyl sulfoxides is stronger than in aryl sulfoxides. The Re=O bond strength in 3 was estimated to be about 20 kcal x mol(-1). The high activity and oxygen electrophilicity of complex 3 are discussed and related to analogous molybdenum systems.

Catalysis↗
PubMed2001

Regulation of DNA binding and trans-activation by a xenobiotic stress-activated plant transcription factor.

As-1-type cis-elements augment transcription of both nuclear and pathogen genes in response to stress and defense cues in plants. Basic/leucine zipper proteins termed "TGA factors" that specifically bind as-1 elements are likely candidates for mediating these transcription activities. Our earlier work has shown that 2, 4-dichlorophenoxyacetic acid-induced xenobiotic stress enhances trans-activation by a chimeric fusion protein of the yeast Gal4 binding domain and TGA1a, a TGA factor of tobacco. Here we demonstrate that xenobiotic stress also enhances the ability of native TGA1a to bind as-1 and activate transcription of a known target gene. In addition, the previously identified xenobiotic stress-responsive domain of TGA1a was found to inhibit this factor's trans-activation potential by a mechanism that appears to involve stimulus-reversible interactions with a nuclear repressor protein. Results from these and other studies can now be placed in the context of a working model to explain basal and xenobiotic stress-induced activities of TGA1a through its cognate cis-acting element.

2,4-Dichlorophenoxyacetic Acid↗
PubMed2001

[Infiltrating ductal carcinomas of the breast in women over 60 years of age. Association with higher cellular proliferation and lower PS2, cell surface and cytosolic hyaluronic acid concentrations].

INTRODUCTION: There are several discrepancies in the literature concerning breast cancer behavior in elderly women. For this reason, we decided to study the possible clinical-biological differences between infiltrating ductal breast carcinomas in women older than 60 and those between 41 and 60 years old. PATIENTS AND METHODS: The study group included 161 women with infiltrating ductal carcinomas of the breast, 90 of whom were women over 60 years and 71 whose ages ranged from 41 to 60 years old. Estrogen receptors (ER), progesterone receptors (PR), pS2, cathepsin D, tissue-type plasminogen activator (t-PA) and hyaluronic acid (HA) cytosolic concentrations were analyzed in addition to those of the epidermal growth factor receptor (EGFR), HA and erbB2/neuoncoprotein in cell surfaces. Size, axillary lymph node involvement, distant metastases, histological grade, ploidy and cellular S-phase fraction were also considered as study variables. RESULTS: Infiltrating ductal carcinomas of the breast in women over 60 had lower pS2 concentrations (p: 0.0367), cell surface (p: 0.021) and cytosolic hyaluronic acid (p: 0.0019) levels than those of women whose ages ranged from 41 to 60 years old. Furthermore, the former had higher S-phase values (p: 0.0345) and percentage of cases with S-phase >7% (p: 0.0483). CONCLUSIONS: The results obtained (higher cellular proliferation and lower pS2, cell surface and cytosolic hyaluronic acid concentrations) suggest that the infiltrating ductal carcinomas of the breast in women older than 60 could have a worse behavior, as has been suggested by other authors, even though further studies with more patients would be needed in order to observe if these biological differences still persist.

Adult↗
PubMed2001

High intensity light increases olfactory bulb melatonin in Venezuelan equine encephalitis virus infection.

In mice infected with the Venezuelan equine encephalomyelitis (VEE) virus and exposed to high intensity light (2500 lux) with a 12 h light: 12 h dark photoperiod, a significant increase in the levels of melatonin in the olfactory bulb was observed. The significance of these findings deserves further studies to understand the mechanisms involved in this effect since the olfactory bulbs have been proposed as first portal for VEE virus entry into the CNS. The increase in melatonin content could represent one of the mechanisms of defense against the viral attack.

Animals↗