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Featured researches published by Ismael Hernandez.


Journal of Hepatology | 1997

Ursodeoxycholic acid in the treatment of cholestasis of pregnancy: a randomized double-blind study controlled with placebo

Joaquín Palma; Humberto Reyes; José Ribalta; Ismael Hernandez; Lorena Sandoval; Ramón Almuna V; Juris Liepins; Fernando Lira; Manuel Sedano; Octavio Silva; Dolores Tohá; Juan Jorge Silva

BACKGROUND/AIMS Intense pruritus and the risk of stillbirths and premature deliveries justify the search for an effective pharmacologic treatment of intrahepatic cholestasis of pregnancy. This study was designed to test the efficacy of ursodeoxycholic acid in maternal pruritus, the biochemical abnormalities and the outcome of pregnancy, in patients with intrahepatic cholestasis of pregnancy of early onset. METHODS Pregnant patients hospitalized in a secondary case-referral center with intense pruritus and abnormal serum levels of bile salts and aminotransferases, detected before week 33 of pregnancy, were randomly assigned to receive ursodeoxycholic acid, 1 g per day orally, or an identical placebo, until delivery, in a double-blind study. A 3-week trial period was chosen to compare drug and placebo effects. The follow-up was extended for 3 months after delivery. RESULTS Twenty-four patients entered the trial; eight had deliveries before 2 weeks of treatment and one dropped out. The study was then completed in 15 patients: eight received ursodeoxycholic acid and seven placebo. No adverse effects were detected in the mothers or in their babies. After 3 weeks of treatment, patients receiving ursodeoxycholic acid (mean daily dose 16 mg/kg body weight) had a significant improvement in pruritus (p<0.02), in serum bilirubin (0.36+/-0.19 mg/dl (mean+/-SD) versus 0.95+/-0.48 in patients receiving placebo, p<0.01), in aspartate aminotransferase (52+/-42 IU/l vs 98+/-44, p<0.05) and in alanine aminotransferase (54+/-50 IU/l vs 229+/-154, p<0.01); serum total bile salts also tended to be lower in patients receiving ursodeoxycholic acid (26.3+/-33.7 micromol/l vs 55.0+/-44.8, p N.S.). Deliveries occurred at or near term in all mothers who received ursodeoxycholic acid (mean week of pregnancy: 38), while they occurred before week 36 of pregnancy in five patients who received placebo, including one stillbirth. All babies born alive had birth weights adequate for gestational age and they were thriving normally 3 months after delivery. CONCLUSIONS Ursodeoxycholic acid is effective and safe in patients with intrahepatic cholestasis of pregnancy of early onset, attenuating pruritus and correcting some biochemical abnormalities in the mothers. Relevant aspects of fetal outcome were also improved in patients receiving ursodeoxycholic acid compared to placebo.


Gastroenterology | 2012

Efficacy of ursodeoxycholic acid in treating intrahepatic cholestasis of pregnancy: a meta-analysis.

Yannick Bacq; Loïc Sentilhes; Humberto B. Reyes; Anna Glantz; Jurate Kondrackiene; Tomáš Binder; Pier Luigi Nicastri; Anna Locatelli; Annarosa Floreani; Ismael Hernandez; Vincent Di Martino

BACKGROUND & AIMS We performed a meta-analysis to evaluate the effects of ursodeoxycholic acid (UDCA) on pruritus, liver test results, and outcomes of babies born to women with intrahepatic cholestasis of pregnancy (ICP). METHODS We performed a systematic review of 9 published, randomized controlled trials (3 double blinded) that compared the effects of UDCA to other drugs, placebo, or no specific treatment (controls) in patients with ICP. We analyzed data from 454 patients: 207 received only UDCA, 70 received only placebo, 42 received cholestyramine, 36 received dexamethasone for 1 week and then placebo for 2 weeks, 65 received S-adenosyl-methionine, and 34 received no specific treatment. To achieve consistency among end points, a standard questionnaire was sent to all corresponding authors. For each end point, we performed pooled analysis that compared the effects of UDCA with those of all controls and UDCA with those of placebos. RESULTS In pooled analyses that compared UDCA with all controls, UDCA was associated with total resolution of pruritus (odds ratio [OR], 0.23; 95% confidence interval [CI], 0.07-0.74; P < .01), reduced pruritis (OR, 0.27; 95% CI, 0.13-0.55; P < .0001), normalization of serum levels of alanine aminotransferase (ALT) (OR, 0.23; 95% CI, 0.10-0.50; P < .001), decreased serum level of ALT (OR, 0.24; 95% CI, 0.11-0.52; P < .0001), reduced serum levels of bile acids (OR, 0.37; 95% CI, 0.19-0.75; P < .001), fewer premature births (OR, 0.44; 95% CI, 0.24-0.79; P < .01), reduced fetal distress (OR, 0.46; 95% CI, 0.25-0.86; P < .01), less frequent respiratory distress syndrome (OR, 0.30; 95% CI, 0.12-0.74; P < .01), and fewer neonates in the intensive care unit (OR, 0.49; 95% CI, 0.25-0.98; P = .046). In pooled analyses that compared the effects of UDCA with placebo, UDCA reduced pruritus (OR, 0.21; 95% CI, 0.07-0.62; P < .01), normalized (OR, 0.18; 95% CI, 0.06-0.52; P < .001) or decreased serum levels of ALT (OR, 0.12; 95% CI, 0.05-0.31; P < .0001), and reduced serum levels of bile acids (OR, 0.30; 95% CI, 0.12-0.73; P < .01). CONCLUSIONS Based on a meta-analysis, UDCA is effective in reducing pruritus and improving liver test results in patients with ICP; UDCA therapy might also benefit fetal outcomes.


Journal of Hepatology | 2000

Selenium, zinc and copper plasma levels in intrahepatic cholestasis of pregnancy, in normal pregnancies and in healthy individuals, in Chile

Humberto Reyes; María E. Báez; Manuel C. Gonzalez; Ismael Hernandez; Joaquín Palma; José Ribalta; Lorena Sandoval; Rodrigo Zapata

BACKGROUND/AIMS Low blood Se levels have been previously shown in normal pregnancies (third trimester) and significantly lower levels in patients with intrahepatic cholestasis of pregnancy (ICP), in Finland and in Chile, suggesting that a low or marginal dietary availability of Se may contribute to the pathogenesis of this disease. The aim of this study was to investigate whether a temporal change in plasma concentration of Se, and seasonal fluctuations in plasma concentrations of Se, Zn and Cu, could coincide with changes in the prevalence of ICP. METHODS A cross-sectional cohort study was done including 21 ICP patients, 98 women in the third trimester of a normal pregnancy, 29 non-pregnant women, and also 13 individuals (seven non-pregnant women and six men) who had been studied 9 years before. Plasma Se, Zn and Cu were measured by atomic spectroscopy. Plasma Se levels in the present study were compared to the results obtained 5 to 7 years before, employing identical methodology in similar population samples. RESULTS Plasma Se concentrations in non-pregnant women were higher than in the previous study: 1.43+/-0.34 micromol/l vs 0.85+/-0.13; p<0.001. In comparison to non-pregnant women, normal pregnancies near term had lower plasma levels of Se: 1.08+/-0.25 micromol/l; p<0.01, and Zn: 17.90+/-3.61 micromol/l vs 19.71+/-3.21; p<0.05, but higher plasma levels of Cu: 34.35+/-7.12 micromol/l vs 20.62+/-3.34; p<0.01. In normal pregnancies, plasma Se concentration was significantly higher in summer (1.34+/-0.19 micromol/l) than in the other seasons, while Zn and Cu diminished. Similar to previous studies, ICP patients had significantly lower Se plasma levels than normal pregnancies: 0.94+/-0.12 micromol/l, p<0.05, and Cu levels were significantly higher: 50.80+/-7.02 micromol/l, p<0.01. Cu plasma levels correlated with the biochemical severity of the disease. Zn did not change in ICP. CONCLUSIONS The present study shows that the decrease in the prevalence of ICP in Chile during the last decade coincides with an increase in plasma Se levels. Its lower incidence during summer coincides with a higher plasma Se concentration in summer than in other seasons, as observed in normal pregnancies.


Liver International | 2005

Ursodeoxycholic acid in the treatment of intrahepatic cholestasis of pregnancy. A 12-year experience.

Rodrigo Zapata; Lorena Sandoval; Joaquín Palma; Ismael Hernandez; José Ribalta; Humberto Reyes; Manuel Sedano; Dolores Tohá; Juan Jorge Silva

Abstract: Objective: To assess the efficacy of ursodeoxycholic acid (UDCA) in patients with intrahepatic cholestasis of pregnancy (ICP) and in the outcome of pregnancy.


Journal of Hepatology | 1997

Profiles of bile acids and progesterone metabolites in the urine and serum of women with intrahepatic cholestasis of pregnancy

Ling-Jie Meng; Humberto Reyes; Joaquín Palma; Ismael Hernandez; José Ribalta; Jan Sjövall

BACKGROUND/AIMS AND METHODS The etiology of intrahepatic cholestasis of pregnancy (JCP) is unknown. We have performed comprehensive chromatographic and mass spectrometric analyses of progesterone metabolites and bile acids in serum and urine of six patients in order to characterize changes that might be of importance for the development of the disease. RESULTS Conjugated bile acids were increased in serum and urine of patients with ICP while the levels of unconjugated bile acids were similar in healthy pregnancies and ICP. Unconjugated and conjugated 7 alpha, 12 alpha-dihydroxy-3-oxo-4-cholenoic acid was excreted in urine both in healthy pregnancies and in ICP, possibly indicating a rate limitation of 3-oxo-delta 4-steroid 5 beta-reductase in pregnancy. The serum levels and urinary excretion of total sulfated progesterone metabolites were increased in ICP while the glucuronides were unchanged or low. Confirming previous results, the fraction of metabolites with 3 alpha-hydroxy-5 alpha(H) configuration was increased. The urinary excretion of 5 alpha-pregnane-3 alpha, 20 alpha-diol 3-sulfate, 20-N-acetylglucosaminide was greatly increased in ICP, as was that of 3 alpha-hydroxy-5 alpha-androstane-17 beta-carboxylic acid, assumed to be a progesterone metabolite. CONCLUSIONS The combined results of this and previous studies are compatible with a primary change in the reductive metabolism of progesterone in ICP, resulting in increased formation of metabolites with a 3 alpha-hydroxy-5 alpha(H) configuration and a larger fraction of sulfates. There also seems to be a selective defect in the biliary secretion of sulfated metabolites, particularly disulfates.


Journal of Hepatology | 1997

Effects of ursodeoxycholic acid on conjugated bile acids and progesterone metabolites in serum and urine of patients with intrahepatic cholestasis of pregnancy

Ling-Jie Meng; Humberto Reyes; Jonquin Palma; Ismael Hernandez; José Ribalta; Jan Sjövall

BACKGROUND/AIMS AND METHODS The mechanism(s) behind the effects of ursodeoxycholic acid on serum steroid sulphate profiles in patients with intrahepatic cholestasis of pregnancy is not clear. Conjugated progesterone metabolites and bile acids have therefore been analysed in serum and urine of patients with intrahepatic cholestasis of pregnancy before and during treatment with ursodeoxycholic acid using chromatographic and mass spectrometric methods. RESULTS The concentration of glycine-/taurine-conjugated bile acids decreased from 8.9+/-3 micromol/l (mean+/-SEM) before treatment to 1.8+/-0.6 micromol/l during treatment with ursodeoxycholic acid. The total bile acid excretion in urine decreased from 56+/-14 to 32+/-5.6 micromol/g creatinine. The proportion of cholic acid in serum and urine, and of 1beta-, 2beta- and 6alpha-hydroxylated cholic acids in urine decreased markedly during ursodeoxycholic acid while the percentages of 3alpha,12alpha-dihydroxy-3-oxo-4-cholenoic acid and chenodeoxycholic acid were unchanged. The levels in serum and excretion in urine of sulphated steroids decreased during ursodeoxycholic acid, by 45-49% for disulphates and 33-35% for monosulphates. The ratios of 3alpha- to 3beta-hydroxysteroid disulphates were lowered by ursodeoxycholic acid from 1.1 (mean) to 0.68 in serum, and from 1.2 to 0.70 in urine. The corresponding ratios for monosulphates before and during ursodeoxycholic acid were 6.9 and 4.5, respectively, in serum, and 21 and 5.2, respectively, in urine. The major monosulphates in urine, dominated by 5alpha-pregnane-3alpha, 20alpha-diol, were also conjugated with N-acetylglucosamine. The excretion of these double conjugates decreased from 27+/-8.4 to 15+/-5.3 micromol/g creatinine during ursodeoxycholic acid. In contrast to sulphated steroids, the concentrations of glucuronides were unchanged in serum and their excretion in urine tended to increase during ursodeoxycholic acid. The metabolism of ursodeoxycholic acid was similar to that described in nonpregnant subjects. In addition to metabolites hydroxylated in the 1beta-, 5beta-, 6alpha/beta and 22-positions, a 4-hydroxy-ursodeoxycholic acid was tentatively identified. This occurred predominantly as a double conjugate with glycine/taurine and glucuronic acid, as did other 4-hydroxylated bile acids of probable foetal origin. CONCLUSIONS The results are compatible with the contention that ursodeoxycholic acid stimulates the biliary excretion of sulphated progesterone metabolites, particularly those with a 3alpha-hydroxy-5alpha(H) configuration and disulphates. The effect(s) appears to be independent of the stimulation of bile acid secretion. An effect of ursodeoxycholic acid on the reductive metabolism of progesterone cannot be excluded.


Hepatology | 2006

Is a leaky gut involved in the pathogenesis of intrahepatic cholestasis of pregnancy

Humberto Reyes; Rodrigo Zapata; Ismael Hernandez; Martin Gotteland; Lorena Sandoval; María Isabel Jirón; Joaquín Palma; Ramón Almuna V; Juan Jorge Silva

Increased gastrointestinal permeability has been demonstrated in several liver diseases. It may facilitate the absorption of gut‐derived endotoxin‐stimulating Kupffer cells to release proinflammatory cytokines or other potentially hepatotoxic compounds. We examined gastrointestinal permeability, plasma levels of anti‐lipopolysacharides (anti‐LPS), and four proinflammatory cytokines in 20 patients with intrahepatic cholestasis of pregnancy (ICP) compared with 22 normal pregnant and 29 non‐pregnant women. Urinary excretion of sucrose and the urinary lactulose/mannitol (L/M) ratio after a standard oral load were used to assess gastrointestinal permeability. Anti‐LPS (IgA, IgM, and IgG) were measured in peripheral blood by Human EndoCAb test kit; TNF‐α, IL‐1β, IL‐6, and IL‐10 by Quantikine HS human immunoassays. Sucrose urinary excretion was similar in the three groups, indicating normal gastric permeability. The urinary L/M ratio was significantly higher in ICP than in the other groups [median (interquartile range): 0.018% (0.011‐0.023) in ICP, 0.012% (0.009‐0.016) in normal pregnancies, and 0.009% (0.008‐0.012) in non‐pregnant women, P < .01]. No significant differences were found in anti‐LPS or cytokines plasma levels except slightly higher levels of IL‐6 in ICP patients than in non‐pregnant women (P < .05). Four of five women with abnormal urinary L/M ratio during ICP continued to show abnormalities in tests up to 2 years after delivery. In conclusion, an increased intestinal permeability was detected in ICP patients during and after pregnancy. A “leaky gut” may participate in the pathogenesis of ICP by enhancing the absorption of bacterial endotoxin and the enterohepatic circulation of cholestatic metabolites of sex hormones and bile salts. (HEPATOLOGY 2006;43:715–722.)


American Journal of Physiology-lung Cellular and Molecular Physiology | 2013

Store-operated channels in the pulmonary circulation of high- and low-altitude neonatal lambs

Daniela Parrau; Germán Ebensperger; Emilio A. Herrera; Fernando A. Moraga; Raquel A. Riquelme; César E. Ulloa; Rodrigo T. Rojas; Pablo Silva; Ismael Hernandez; Javiera Ferrada; Marcela Díaz; Julian T. Parer; Gertrudis Cabello; Aníbal J. Llanos; Roberto V. Reyes

We determined whether store-operated channels (SOC) are involved in neonatal pulmonary artery function under conditions of acute and chronic hypoxia, using newborn sheep gestated and born either at high altitude (HA, 3,600 m) or low altitude (LA, 520 m). Cardiopulmonary variables were recorded in vivo, with and without SOC blockade by 2-aminoethyldiphenylborinate (2-APB), during basal or acute hypoxic conditions. 2-APB did not have effects on basal mean pulmonary arterial pressure (mPAP), cardiac output, systemic arterial blood pressure, or systemic vascular resistance in both groups of neonates. During acute hypoxia 2-APB reduced mPAP and pulmonary vascular resistance in LA and HA, but this reduction was greater in HA. In addition, isolated pulmonary arteries mounted in a wire myograph were assessed for vascular reactivity. HA arteries showed a greater relaxation and sensitivity to SOC blockers than LA arteries. The pulmonary expression of two SOC-forming subunits, TRPC4 and STIM1, was upregulated in HA. Taken together, our results show that SOC contribute to hypoxic pulmonary vasoconstriction in newborn sheep and that SOC are upregulated by chronic hypoxia. Therefore, SOC may contribute to the development of neonatal pulmonary hypertension. We propose SOC channels could be potential targets to treat neonatal pulmonary hypertension.


The Journal of Physiology | 2018

The role of nitric oxide in the cardiopulmonary response to hypoxia in highland and lowland newborn llamas

Roberto V. Reyes; Marcela Díaz; Germán Ebensperger; Emilio A. Herrera; Sebastián A. Quezada; Ismael Hernandez; Emilia M. Sanhueza; Julian T. Parer; Dino A. Giussani; Aníbal J. Llanos

Perinatal hypoxia causes pulmonary hypertension in neonates, including humans. However, in species adapted to hypoxia, such as the llama, there is protection against pulmonary hypertension. Nitric oxide (NO) is a vasodilatator with an established role in the cardiopulmonary system of many species, but its function in the hypoxic pulmonary vasoconstrictor response in the newborn llama is unknown. Therefore, we studied the role of NO in the cardiopulmonary responses to acute hypoxia in high‐ and lowland newborn llamas. We show that high‐ compared to lowland newborn llamas have a reduced pulmonary vasoconstrictor response to acute hypoxia. Protection against excessive pulmonary vasoconstriction in the highland llama is mediated via enhancement of NO pathways, including increased MYPT1 and reduced ROCK expression as well as Ca2+ desensitization. Blunting of pulmonary hypertensive responses to hypoxia through enhanced NO pathways may be an adaptive mechanism to withstand life at high altitude in the newborn llama.


Frontiers in Physiology | 2018

Revisiting the Role of TRP, Orai, and ASIC Channels in the Pulmonary Arterial Response to Hypoxia

Roberto V. Reyes; Sebastián Castillo-Galán; Ismael Hernandez; Emilio A. Herrera; Germán Ebensperger; Aníbal J. Llanos

The pulmonary arteries are exquisitely responsive to oxygen changes. They rapidly and proportionally contract as arterial PO2 decrease, and they relax as arterial PO2 is re-established. The hypoxic pulmonary vasoconstriction (HPV) is intrinsic since it does not require neural or endocrine factors, as evidenced in isolated vessels. On the other hand, pulmonary arteries also respond to sustained hypoxia with structural and functional remodeling, involving growth of smooth muscle medial layer and later recruitment of adventitial fibroblasts, secreted mitogens from endothelium and changes in the response to vasoconstrictor and vasodilator stimuli. Hypoxic pulmonary arterial vasoconstriction and remodeling are relevant biological responses both under physiological and pathological conditions, to explain matching between ventilation and perfusion, fetal to neonatal transition of pulmonary circulation and pulmonary artery over-constriction and thickening in pulmonary hypertension. Store operated channels (SOC) and receptor operated channels (ROC) are plasma membrane cationic channels that mediate calcium influx in response to depletion of internal calcium stores or receptor activation, respectively. They are involved in both HPV and pathological remodeling since their pharmacological blockade or genetic suppression of several of the Stim, Orai, TRP, or ASIC proteins in SOC or ROC complexes attenuate the calcium increase, the tension development, the pulmonary artery smooth muscle proliferation, and pulmonary arterial hypertension. In this Mini Review, we discussed the evidence obtained in in vivo animal models, at the level of isolated organ or cells of pulmonary arteries, and we identified and discussed the questions for future research needed to validate these signaling complexes as targets against pulmonary hypertension.

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