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Biomedical subjects

R Bárcena

Publications and source records attributed to R Bárcena.

At least 19 recordsLinked to original sources
PubMed2006

Viral kinetics and early prediction of nonresponse to peg-IFN-alpha-2b plus ribavirin in HCV genotypes 1/4 according to HIV serostatus.

To evaluate, among 70 hepatitis C virus (HCV)-monoinfected and 36 human immunodeficiency virus (HIV)-coinfected naïve patients with genotypes 1/4 receiving weight-adjusted pegylated interferon-alpha-2b/ribavirin, viral kinetics and the feasibility to predict treatment failure measuring early HCV-RNA decreases. HCV-RNA was assessed at baseline, weeks 4, 12 and 24. Receiver operating characteristic (ROC) curves were calculated to determine the most sensitive cut-off values of viral decrease at week 4 predicting treatment failure. Baseline predictors of failure were evaluated by univariate and multivariate analyses. Despite similar baseline HCV-RNA (5.75 vs 5.72 log(10)IU/ml, P = 0.6), HCV monoinfection led to significantly lower HCV-RNA values at weeks 4 (3.7 vs 4.3 log(10)IU/ml, P = 0.01), 12 (2.3 vs 3.5 log(10)IU/ml, P = 0.01) and 24 (1.4 vs 3.3 log(10)IU/ml, P = 0.001) and a higher rates of viral clearance at weeks 24 (60%vs 36%, P = 0.02), 48 (46%vs 25%, P = 0.03) and 72 (37%vs 17%). The lack of achieving an HCV-RNA decrease of at least 1 log(10) at week 4 was highly predictive of treatment failure for HCV-monoinfected patients (Se 100%, Sp 50%, positive predictive value (PPV) 57%, negative predictive value (NPV) 100%, ROC curve area, 0.86 [95% confidence interval (CI) 0.77-0.95], but not for HCV/HIV-coinfected patients (cut-off, 0 log(10), Se 100%, Sp 27%, PPV 21%, NPV 100%, ROC curve area, 0.71 (95% CI 0.49-0.93). HIV coinfection was independently associated with failure (odds ratio 2.95, 95% CI 1.08-8.04, P = 0.01). Thus the magnitude of HCV-RNA decreases at week 4 correlated with treatment response. Significant differences in viral kinetics and cut-off values predicting nonresponse suggest a slower HCV clearance rate in HIV coinfection, which was independently associated with treatment failure.

Adult↗
PubMed2005

Study on the efficacy and safety of adefovir dipivoxil treatment in post-liver transplant patients with hepatitis B virus infection and lamivudine-resistant hepatitis B virus.

Hepatitis B virus (HBV) recurrence and de novo HBV infection are frequent events in liver transplantation recipients. Treatment with lamivudine is initially efficient in both infections but the incidence of lamivudine-resistant HBV emergence increases over time. Adefovir appears to be promising in post-liver transplantation patients with recurrent HBV infection and lamivudine-resistant HBV. This study analyzed adefovir treatment in 42 post-liver transplantation patients who developed recurrent HBV or de novo HBV infection with lamivudine-resistant HBV (54.8% HCV-coinfected). Patients received 10 mg of oral adefovir once daily for a mean period of time of 21.5 months (range from 12 to 31 months). In 62.9% of patients, ALT levels decreased significantly. Serum HBV-DNA was undetectable in 64% of the cases. Twenty percent of patients lost HBeAg marker and 13.3% of them developed anti-HBe. In 9.5% of recipients, HBsAg became negative. There was no significant change in serum creatinine levels. In only one patient was worsening of the renal function detected, making dose adjustment necessary. No other side effects were reported. Our results confirm the efficacy and safety of adefovir treatment in post-liver transplantation patients with lamivudine-resistant HBV, neither were adefovir-resistant mutations identified in patients after 21 months of therapy, nor were there adverse events, especially renal toxicity.

Adenine↗
PubMed2003

Beneficial effects of HLA class II incompatibility in living donor liver transplantation.

OBJECTIVE: To analyze the impact of HLA matching in both patient and graft evolution after LDLT. MATERIAL AND METHODS: Twenty recipients underwent LDLT with follow-up of 3 to 30 months. HLA typing was performed on all donor-recipient pairs; class I antigens were typed using serological methods and class II loci (DRB1 and DQB1) using low-resolution molecular typing. Recipient sera were cross-matched with donor lymphocytes. Antigen mismatches were analyzed for each locus individually, for each class as a whole and for HLA class I immunogenic triplets according to HLA Matchmaker software. RESULTS: Eighteen of 20 donor-recipient pairs were HLA haploidentical. All but one of the recipients had a negative cross-match before transplantation. While there was not a statistically significant correlation between HLA class I mismatches and the incidence of acute rejection episodes, HLA class II matching in DRB1 and DQB1 loci appeared to be associated with a higher incidence of acute rejection episodes after LDLT. Both host-versus-graft (HvG) and graft-versus-host (GvH) HLA class II compatibilities correlated with rejection episodes, especially for the GvH direction. CONCLUSIONS: HLA class II matching for DRB1 and DQB1 loci appears to be associated with a higher incidence of acute rejection episodes after LDLT. In this study, mismatches in class I HLA antigens are not related to an higher incidence of acute rejection episodes nor other complications after LDLT. Further studies are needed to unveil the role of HLA matching in LDLT.

Adolescent↗
PubMed2003

Survival and complication rates in liver transplant patients showing primary dysfunction versus normofunction.

AIMS: To determine rates of vascular and biliary duct complications, acute rejection, and graft and patient survival according to function status following liver transplantation. METHODS: We classified 248 consecutive liver transplants performed at the Hospital Ramón y Cajal, Madrid, over a 79-month period according to initial function as primary function (NP) versus dysfunction (PD). The latter group was subdivided into grafts showing primary failure (PF) or inadequate function (IPF). The classes NP and IPF were distinguished according to whether transaminase (GOT or GPT) levels and prothrombin activity were above or below 2000 IU and 50%, respectively. RESULTS: There were 23 (9.3%) patients with PD, of whom 12 (4.8%) showed PF. The incidence of vascular and biliary duct complications was similar in both groups, although acute rejection showed a significant difference (PD 3/23 versus NP 98/225; odds ratio =.18). In contrast, the mean survival rates of the grafts (NP 60.37 versus IPF 39.90 months) or patients (NP 63.02 versus PD 47.10 months) were not significantly different. Only 1- and 3-month graft survival rates significantly differed between the NP and IPF groups (NP 95% versus IPF 63%; P=.03 and NP 89% versus IPF 58%; P=.02, respectively). CONCLUSIONS: Recipients with PD or NP after liver transplant showed no differences in the incidence of vascular or biliary duct complications. These groups did vary, however, in terms of rates of acute rejection episodes. No differences in graft and patient survival rates were observed except a significantly lower graft survival at 1 and 3 months, among patients with inadequate primary function.

Follow-Up Studies↗
PubMed2002

Implications of estradiol and progesterone in pulmonary vasodilatation in cirrhotic patients.

The derangement of sex hormone serum levels in cirrhotic patients is well-delineated, and increased levels of progesterone and estradiol have been associated to hyperventilation in cirrhotic patients. These hormones have a well-known role in the regulation of vascular tone. The aim of this study was to evaluate whether sex hormone levels contribute to pulmonary vasodilatation (PV) and gas exchange abnormalities in cirrhosis. Contrast transesophageal echocardiography, arterial blood gases, parameters of liver function, pulmonary function test, estradiol and progesterone levels were determined in 45 male cirrhotic patients. Nineteen of 45 patients (42.2%) presented PV. Hyperventilation (pressure arterial of CO2< or =35 mmHg) was correlated to progesterone levels (p<0.05) and pressure arterial of CO2 was high in patients with PV (p<0.005) and Child class B and C (p<0.01). Hypoxemia (pressure arterial of O2<80 mmHg) had inverse correlation with progesterone (p<0.05) and estradiol (p<0.05) levels and pressure arterial of O2 was low in patients with Child class B and C (p<0.05). PV was present in patients with high estradiol levels (p<0.05), high progesterone levels (p<0.005) and Pugh class B and C (p<0.05). Logistic regression analysis identified progesterone as the sole independent factor associated to PV (p<0.0005). Multivariate linear regression showed that PV was the sole independent factor related to both pressure arterial of CO2 (p<0.05) and pressure arterial of O2 (p<0.01) levels. PV was independently associated to gas exchange abnormalities in cirrhosis. Progesterone and estradiol were related with PV in cirrhotic patients.

Carbon Dioxide↗
PubMed2002

Effect of exogenous fibrolytic enzyme on ruminal fermentation and digestibility of alfalfa and rye-grass hay fed to lambs.

This experiment was carried out to study the effect of a directly fed exogenous fibrolytic enzyme on intake and digestion of DM, OM, protein, NDF, ADF, and hemicellulose of alfalfa and ryegrass hay by sheep. Four diets were randomly assigned to four ruminally cannulated lambs using a 4 x 4 Latin square design, repeated in time, with a factorial arrangement (2 x 2) of diets: 1) alfalfa hay; 2) alfalfa hay + exogenous fibrolytic enzymes (enzyme); 3) ryegrass hay; and 4) ryegrass hay + enzyme. Lambs consumed more DM and OM from alfalfa than from ryegrass hay (P < 0.001). The ADF intake was not different between the hays, but NDF intake was lower for alfalfa (P < 0.001). For both hays, the enzyme increased intake of DM (P < 0.01), as well as OM and CP (P < 0.05); however, NDF and ADF intake were not changed. Alfalfa hay had higher apparent digestibility of DM, OM, and CP (P < 0.001), but lower digestibility for NDF, ADF, and hemicellulose. The enzyme increased apparent digestibility of CP, hemicellulose (P < 0.05), and NDF (P < 0.10) for alfalfa. Also, for both hays, the enzyme improved N balance because lambs retained more N (P < 0.05). The enzyme increased (P < 0.05) total VFA concentration (3 and 6 h) for both hays. Results from this trial indicate that directly fed exogenous fibrolytic enzymes may change ruminal fermentation, intake, and digestibility of forages with different nutritive value.

Animals↗
PubMed2002

Sleep electroencephalogram alterations disclose initial stage of encephalopathy.

UNLABELLED: Minimal hepatic encephalopathy is often present in patients with chronic liver disease. The aim of this work was to determine changes in the dynamics of sleep electroencephalogram (EEG) in cirrhotic patients without overt encephalopathy. Twenty such cirrhotic subjects included in the protocol of hepatic transplantation of our hospital were studied and compared with 20 age-matched healthy volunteers. Spectral analysis of all-night EEG was estimated by computing the fast-Fourier transform in 2-second epochs, and averaging every 60 seconds. Artifacts were off-line suppressed, sleep stages (stage 2, stage 3-4 and REM) were determined, and the EEG mean dominant frequency (MDF) was calculated in each of these stages. Results show that in cirrhotic patients, nocturnal MDF evolution discloses a clear alteration of the ultradian EEG frequency oscillations present in controls. Also, the mean value of MDF in REM episodes was larger in cirrhotics than the corresponding value in controls. CONCLUSIONS: 1) sleep EEG evidences the existence of minimal hepatic encephalopathy; 2) the spectral analysis of EEG in minimal hepatic encephalopathy showed that the changes of MDF during sleep are an early marker of cerebral dysfunction in cirrhotic patients.

Electroencephalography↗
PubMed2001

Liver transplantation for type Ib glycogenosis with reversal of cyclic neutropenia.

We describe a case of glycogen storage disease type Ib in 32-year old male patient with poor metabolic control in spite of medical and nutritional management and the use of recombinant granulocyte stimulating factor. Because of this, liver transplantation was considered as a definitive treatment. We comment on the metabolic results of liver transplantation performed, with reversal of hypoglycemia, hyperuricemia, hypertriglyceridemia and cyclic neutropenia, all of which persist 4 years post-transplant. In view of this case, we believe that liver transplantation is a feasible option to consider in patients with type Ib glycogenosis as a definitive therapeutic procedure.

Adult↗
PubMed2000

Vaccination against hepatitis B virus in cirrhotic patients on liver transplant waiting list.

Patients with cirrhosis may fail to respond to anti-hepatitis B vaccine. An adequate response would be especially interesting when patients are on a liver transplant waiting list. Posttransplantation de novo hepatitis B has been well documented. One possible source is the grafting of organs from hepatitis B surface antigen (HBsAg)-negative, antibody to HBsAg (anti-HBs)-positive, antibody to hepatitis B core antigen-positive donors. The achievement of high titers of anti-HBs could be protective in this setting. We studied prospectively the response rate to recombinant hepatitis B vaccine (3 40-microg doses administered at 0, 1, and 2 months) in 62 patients with end-stage liver disease awaiting liver transplantation. Twenty-two patients showed antibody response (44%). A further 3 doses were administered in 15 of 28 nonresponders and were effective in 9 patients. Thus, the response rate reached 62% (31 of 50 patients completing 1 or 2 vaccination schedules before liver transplantation). Classic hepatitis B vaccination studies of patients with cirrhosis yield lower response rates. Vaccination with this double-dose schedule should be considered in such patients before liver transplantation.

Adolescent↗