Antonio Ríos

FoxP3 in peripheral blood is associated with operational tolerance in liver transplant patients during immunosuppression withdrawal.

Background. Human liver allografts do sometimes survive in a recipient after withdrawal of immunosuppression (IS), commonly referred to as “operational tolerance.” Preliminary clinical data have suggested an increase in the frequency of regulatory T cells (Treg) CD4+CD25high and FoxP3 expression in operationally tolerant liver transplant recipients (Gr-T). In the context of human liver transplantation, the dynamics of Treg have not been studied. We designed a prospective study to ascertain the profile of the Treg population and FoxP3 expression during IS withdrawal. Methods. To identify such parameters, we analyzed peripheral blood mononuclear cell populations and FoxP3 mRNA expression in 12 liver allograft recipients under cyclosporine A-based IS, who showed stable function of the allograft for more than 2 years. Results. An increase was observed in the frequency of CD4+CD25high cells when the IS was withdrawn in Gr-T patients (n=5). These patients exhibited a 3.5-fold increase for relative mRNA FoxP3 expression before the complete IS withdrawal and this continued when IS therapy was stopped. In patients who suffered rejection (n=7) there was no increase in the CD4+CD25high cells or FoxP3 expression. Conclusions. With the present study, the first evidence is provided that the increase of CD4+CD25high T cells and FoxP3 transcripts is associated with operational tolerance in liver transplanted patients during IS withdrawal.

Experimental Ulcerative Colitis Impairs Antioxidant Defense System in Rat Intestine

Increasing attention has been given recently to the role of free radicals in the pathogenesis of ulcerative colitis, since the inflamed intestine is exposed to oxidative stress generated by infiltrating macrophages and neutrophils within the lamina propia. The overall goal of this study was to evaluate whether experimental ulcerative colitis induces significant changes in the antioxidant defense system in an experimental model induced by the intrarectal administration of 2,4,6-trinitrobenzenesulfonic acid. Twenty rats were treated with 80 mg/kg body weight of trinitrobenzenesulfonic acid and 20 with the same volume of 0.9% NaCl. Rats were killed at one and two weeks after treatment to evaluate colon damage by light and electron transmission microscopy. The degree of tissue injury and inflammation was determined by measuring alkaline phosphatase, γ-glutamyltranspeptidase, and myeloperoxidase activities and prostaglandin E2 and leukotriene B4. Glutathione levels and the activity of the enzymes of the antioxidant defense system were determined. Enzymatic markers of colon injury showed higher activities in rats with ulcerative colitis. Concentrations of prostaglandin E2 and leukotriene B4 were higher in the groups treated for one week with trinitrobenzenesulfonic acid and markers decreased after two weeks of treatment. All antioxidant enzyme activities were higher at one and two weeks after treatment; however, a significant decrease in total glutathione content was also observed. In conclusion, ulcerative colitis induced by trinitrobenzenesulfonic acid damages the intestinal mucosa and is accompanied by a shift in the antioxidant enzyme activities, and low levels of glutathione. This deficiency in glutathione could be a target for new therapies to treat ulcerative colitis.

Effect of dietary nucleotides on small intestinal repair after diarrhoea. Histological and ultrastructural changes.

The effects of specific nutrients on intestinal maturation and repair after injury are practically unknown. The purpose of this work was to study the effects of dietary nucleotides on the repair of the intestinal mucosa after chronic diarrhoea induced by a lactose enriched diet in the weanling rat. One group of weanling rats was fed with a standard semipurified diet (control group), and another group was fed with the same diet containing lactose as the only soluble carbohydrate (lactose group). After 14 days the lactose group was allowed to recover for four weeks with the control diet (lactose-control group) or with the control diet supplemented with AMP, GMP, IMP, CMP, and UMP 50 mg/100 g each (lactose-nucleotide group). The control group was divided into two subgroups, which were fed with the control diet and the nucleotide supplemented diet for the same period (control-control group and control-nucleotide group). The lactose diet induced diarrhoea after 24 hours of feeding. Two weeks later there were changes in intestinal structure with loss of enterocyte microvillar surface, significant lymphocyte infiltration, supranuclear cytoplasmic vesiculation, decreased number of goblet cells, and enlarged mitochondria with low density and few cristae. After recovery from diarrhoea, animals fed the nucleotide enriched diet showed an intestinal histology and ultrastructure closer to that of the normal control group. Mitochondrial ultrastructure was closer to normal in comparison with the lactose-control diet group. In this second group the number of goblet cells as well as the villous height/crypt depth ratio was reduced and the number of intraepithelial lymphocytes increased compared with the nucleotide supplemented group. These results suggest that dietary nucleotides may be important nutrients for intestinal repair.

Dietary Monounsaturated n-3 and n-6 Long-Chain Polyunsaturated Fatty Acids Affect Cellular Antioxidant Defense System in Rats with Experimental Ulcerative Colitis Induced by Trinitrobenzene Sulfonic Acid

The intrarectal administration oftrinitrobenzene sulfonic acid in rats induces ulcerativecolitis, which results in histological alterations ofcolonic mucosa, severe modification of the cellularantioxidant defense system, and enhanced production ofinflammatory eicosanoids. This study evaluated theinfluence of different dietary fatty acids, ie,monounsaturated, n-3, and n-3 + n-6 polyunsaturatedfatty acids, on the recovery of the colonic mucosahistological pattern, the cellular antioxidant defensesystem of colon, and PGE2 and LTB4colonic mucosa contents in a model of ulcerative colitisinduced by intrarectal administration of trinitrobenzene sulfonicacid. Administration of dietary n-3 polyunsaturatedfatty acids led to a minimum stenosis score, a higherhistological recovery, lower colon alkaline phosphatase and gamma-glutamyltranspeptidase activities,and lower mucosal levels of PGE2 andLTB4 compared with the other two experimentalgroups. However, glutathione transferase, glutathionereductase, glutathione peroxidase, and catalase activities were lowerin the group treated with n-3 polyunsaturated fattyacids than in the groups fed with either themonounsaturated or the n-6 + n-3 polyunsaturatedenriched diet. We conclude that n-3 polyunsaturatedfatty acids can be administered to prevent inflammationin ulcerative colitis, but they cause a decrease in thecolonic antioxidant defense system, promoting oxidative injury at the site of inflammation.

Serum amino acid changes in rats with thioacetamide-induced liver cirrhosis

To date, no attempt has been made to study alterations occurring in the amino acid profile in chronic models of thioacetamide-induced liver cirrhosis. In this work, changes in serum amino acids and proteins in rats with thioacetamide-induced liver cirrhosis are reported, together with changes in enzyme activities in the liver and serum. Seventeen female Wistar rats were used. Eight rats were given 300 mg thioacetamide/l in drinking water for 4 months and nine rats were given water ad libitum during the same time-period. Significant increases in glycine, alanine, serine, methionine, glutamate, ornithine, phenylalanine, tyrosine, histidine and proline were observed in rats with the resulting experimental liver cirrhosis. Threonine, taurine, glutamine, lysine and citrulline tended to increase while isoleucine, leucine, aspartate, arginine and tryptophan tended to decrease. Total and nonessential amino acids increased significantly in cirrhotic animals. Total essential and aromatic amino acids tended to increase in the thioacetamide-treated group, whereas branched chain amino acids tended to decrease in the same group. Regarding serum proteins, a decrease in albumin concentration in the thioacetamide-treated animals was the only change detected. The liver enzyme activities under observation (aspartate and alanine aminotransferases, glutamate dehydrogenase and threonine deaminase) were lower in the thioacetamide group. Decreases were significant for both transaminases and threonine deaminase. Results for serum activities showed that transaminases did not change in thioacetamide-treated rats in comparison with controls. In contrast, alkaline phosphatase rose dramatically in cirrhotic rats. We conclude that the serum amino acid pattern in this chronic model of liver cirrhosis resembles in part that of the corresponding human disease.

Spatial and temporal correlation between early nerve fiber growth and neuroepithelial cell death in the chick embryo retina.

SummaryThe distribution of cell death in the ventral pycnotic zone of the chick embryo retina was studied in Hamburger-Hamiltons stages 16 to 25 (2 1/2 to 4 1/2 days of incubation). The number of fragments appearing in the retina increases notably from stage 20 at which stage they are limited almost exclusively to the optic disc region. At the same time optic fibers are seen in this area for the first time. In stage 24 cell death phenomena are numerous in the ventral retina, and become even more extensive in the following stage. Stage 25 meanwhile sees a drop in cell death in the dorsal retina. The overall picture presented by cell remains and young ganglion cells indicates that in stages 19–23 cell death occurs mainly in the zone between the ganglion cells of the posterior pole and the optic stalk. In the stage 25 retina most of the cell fragments of the ventral retina are found on either side of the fissure, while ganglion cells in the process of sending out axons toward the fissure appear laterally (nasally and temporally) to these zones of degeneration. Hence a spatial and temporal correlation is established between fiber growth and neuroepithelial cell degeneration, allowing us to construct a hypothesis with regard to the role that cell death might play in setting up an initial pattern of optic fiber growth.

The Latin American population in Spain and organ donation. Attitude toward deceased organ donation and organ donation rates

The Latin American (LA) population has similarities with the Spanish population which makes its integration into Spanish society easier. Objective: to analyze the attitude toward organ donation among Latin American citizens residing in Spain, to determine the psychosocial variables which affect this attitude, and to examine the correlation between donation rates of LA citizens in Spain and in their countries of origin. A random sample of LA residents in Spain was taken and stratified according to the respondents nationality (n = 1.314), in the year 2010. Attitude was assessed using a validated questionnaire (PCID‐DTO Dr Rios). The survey was self‐administered and completed anonymously. Statistical analysis: Students t‐test, the χ2 test, and logistic regression analysis. There was a 94% completion rate (n = 1.237). Attitude toward donation was favorable in 60% of cases (n = 745), 12% (n = 145) were against, and 28% (n = 347) were undecided. The following variables were associated with attitude toward donation: sex (P = 0.038), level of formal education (P < 0.001), country of origin (P = 0.002), attitude toward the donation of a family members organs (P < 0.001), having discussed donation with the family (P < 0.001), carrying out prosocial activities (P = 0.025), attitude toward cremation of the body (P < 0.001), attitude toward burial of the body (P < 0.001), attitude toward having an autopsy carried out (P < 0.001), previous experience of the organ donation and transplantation process (P < 0.001), fear of mutilation after donation (P < 0.001), knowledge that the Church has a positive attitude toward organ donation and transplantation (P < 0.001), knowledge of ones partners attitude toward organ donation (P < 0.001), and a belief that one might need a transplant in the future (P < 0.001). The donation rates in this population group in Spain are higher than those recorded in their countries of origin (55.76 vs. <10 pmp; P < 0.001). The attitude toward organ donation among LA citizens residing in Spain is slightly worse than that reported in the native Spanish population and is determined by many psychosocial factors. The donation rates of LA citizens in Spain are higher than those in their countries of origin.

Experimental colitis induced by trinitrobenzenesulfonic acid: an ultrastructural and histochemical study.

Inflammatory bowel disease (IBD) of humans is achronic and devastating disease of unknown etiology.Models of acute colitis in animals have been achieved byintrarectal administration of agents such as 2,4,6-trinitrobenzenesulfonic acid (TNBS) intorat colon. This agent induces focal inflammation andalterations in the colon with features similar to thosefound in chronic inflammatory diseases in humans. The aim of this study was to assess the effectof TNBS administration on histological andultrastructural features of the rat colon, especially inareas not affected by transmural inflammation. Also in areas without transmural inflammation, weobserved a significant increase in crypt diameter and inthe number and area of the goblet cells, as well asalterations in the contents of mucin in goblet cells. We conclude that TNBS treatment in rats led tosevere changes in normal architecture of the colon andalso in damaged areas where no direct inflammation wasproduced.

Factors that influence the attitude of East European residents in Spain towards living kidney donation

Emigration from East European (EE) countries into the South East of Spain (SES) is becoming more common. The objective of this study was to analyse the attitude towards living kidney donation in this group. A sample of residents (n = 320) in the SES who come from EE was obtained randomly and stratified by a respondent’s nationality (November‐05 to April‐06). Attitude was evaluated using a validated questionnaire that was completed anonymously and was self‐administered. Control group: native Spanish citizens. The questionnaire completion rate was 83% (n = 265). A total of 83% (n = 220) were in favor of related living donation. Attitude is similar to that of the urban control group (P = 0.0534) and more positive than that prevalent in the rural setting (P < 0.001). The variables that were related to attitude included: a respondent’s marital status (P < 0.001); the country of origin (P = 0.014); attitude towards deceased donation (P < 0.001); having discussed the subject within the family (P < 0.001); a respondent’s belief that he might need a transplant organ (P = 0.002) and concern about possible ‘mutilation’ after donation (P < 0.001). There is a favorable attitude towards related living kidney donation among EE who are resident in the SES and this attitude is closely related to attitude towards deceased donation, the attitude of one’s family and feelings of reciprocity.

Results of surgery for toxic multinodular goiter

PurposeWe analyzed the clinical and histological features of patients operated on for toxic multinodular goiter (TMG) to determine the clinical profile and evaluate the surgical results.MethodsWe reviewed 672 patients who underwent surgery for multinodular goiter (MG), 112 (17%) of whom had hyperthyroidism, and analyzed the epidemiological, clinical, and surgical variables.ResultsThe patients with TMG tended to be older than those with nontoxic MG, with a greater evolution time of the goiter and a higher rate of positive antithyroid antibodies. In the multivariate analysis, the only feature characteristic of TMG, as opposed to nontoxic MG, was the evolution time. Morbidity was 34%, representative of the fact that that most of the patients were seen before the establishment of our endocrine surgical unit. The hyperthyroid symptoms resolved in all patients, but 4 of 17 patients who underwent partial surgical resection showed signs of relapse within a follow-up period of 98 ± 71 months.ConclusionsTMG is characterized by a long evolution time and is most effectively treated by total thyroidectomy, which achieves complete remission from symptoms, without relapse, and is necessary if there is associated carcinoma. However, the incidence of complications may be high if this procedure is not carried out by surgeons with experience in endocrine surgery.