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Biomedical subjects

J Enríquez

Publications and source records attributed to J Enríquez.

At least 19 recordsLinked to original sources
PubMed2003

Comparative study of the efficacy of an induction dose of interferon-alpha2b with ribavirin compared with standard combined treatment in naive patients with chronic hepatitis C.

The efficacy and secondary effects of an induction dose of interferon-alpha2b (IFN-alpha2b) with ribavirin compared with standard combined treatment in naive patients with chronic hepatitis C infection were compared. A prospective study was undertaken between March 1998 and November 2001 in which 84 Spanish hospitals took part. Six hundred and fourteen naive patients (age range 18-65 years) diagnosed with chronic hepatitis C virus (HCV) infection and without cirrhosis or co-infection by other viruses, were included. Patients were divided into two groups. Group A (n = 304) received induction treatment with a daily dose of 5 MU of IFN-alpha2b for 4 weeks, followed by 5 MU three times a week with ribavirin (1000-1200 mg/day, according to weight) until completing 1 year of treatment. Group B (n = 310) received the standard dose of IFN-alpha2b of 3 MU three times per week for 48 weeks together with ribavirin (1000-1200 mg/day, according to weight). Both groups were completely comparable according to age, gender, body weight, transaminase levels, genotype, viral load and hepatic inflammatory activity (Knodell Index). No control group was included for ethical reasons. Pegylated interferon was not available at the time of the study. Serum baseline samples were collected for the determination of genotype. Samples were also collected at baseline, weeks 4, 12, 24, 48 and 72, in order to detect and quantify HCV-RNA. The efficacy of treatment was evaluated by means of sustained viral response (SVR) characterized by persistent negativity of HCV-RNA at the end of the follow-up period. At week 4, the response to treatment was greater in group A (49.6%) compared with group B (34.5%) (P = 0.0002), and was maintained until week 12 (64.1% compared with 55.8% respectively) (P = 0.03). These differences disappeared at week 24, when group A (69%) was compared with group B (65%) (NS). At week 48, the response rate for group A was 50.6% compared with group B 47.4% (NS), and at week 72, the SVR in group A was 46% compared with 40.3% for group B (NS). The global SVR was 43.1%. On analysing the response to treatment according to genotype and viral load, we found that the induction treatment was slightly superior in patients with genotype 1 and an elevated viral load (>2 x 10(6) copies/ml). They achieved a SVR in group A of 39.1% compared with 25.5% in group B (P < 0.05). However, this slight improvement obtained in group A, was achieved at the expense of a greater percentage of dropouts compared with group B (6.4% vs 2.2%, P < 0.01); a greater rate of side effects (58.5 vs 36.7%, P < 0.05) and also a greater percentage of neutropenia (3.1% vs 0.9%, P < 0.05). The induction treatment presented a better initial response, but this was not maintained at the end of treatment, and did not improve the results obtained with the standard treatment. Although the patients with genotype 1 and elevated viral load had a better response with the induction treatment, this was accompanied by a greater percentage of dropouts and secondary effects. It would be interesting to repeat this type of study in the future, using pegylated interferon.

Adolescent↗
PubMed2000

Pre-treatment with prednisolone does not improve the efficacy of subsequent alpha interferon therapy in chronic hepatitis C.

BACKGROUND/AIMS: Alpha interferon administration is quite disappointing as a single therapy in chronic hepatitis C. A brief course of corticosteroid therapy might increase the effectiveness of subsequent alpha interferon administration, but data on this issue are controversial. METHODS: One hundred and fifty-six consecutive patients with chronic hepatitis C were randomly assigned to be treated blind with tapering doses of oral prednisolone or placebo for 4 weeks. Two weeks after cessation of therapy, patients received alpha interferon (3 MU t.i.w.) for 48 weeks and were followed for 24 additional weeks. Response was defined by the presence of normal alanine aminotransferase (ALT) and negative HCV-RNA in serum. RESULTS: ALT activity decreased during prednisolone administration and rebounded upon withdrawal in 38% of the patients treated with this drug. Significant changes in serum bilirubin were not observed. HCV-RNA serum concentration tended to increase during prednisolone administration and to decrease upon withdrawal. ALT and HCV-RNA did not change during administration of placebo. At the end of interferon administration, 33% of patients treated with prednisolone and 25% of those treated with placebo presented biochemical and virological response. At the end of post-treatment follow-up, response was maintained in 12% and 13% of patients treated with prednisolone or placebo respectively. Response was not related to ALT or HCV-RNA changes observed during the pre-interferon phase of the study. No adverse events related to prednisolone administration were observed. CONCLUSIONS: Prednisolone administration and withdrawal induced a rebound in ALT activity and a decrease in HCV-RNA serum concentration in about one third of the patients with chronic hepatitis C. However, these changes did not enhance the effectiveness of subsequent alpha interferon therapy.

Adult↗
PubMed2000

Retreatment for 24 vs 48 weeks with interferon-alpha2b plus ribavirin of chronic hepatitis C patients who relapsed or did not respond to interferon alone.

We assessed the efficacy of interferon (IFN) plus ribavirin over 24 or 48 weeks for the retreatment of patients with chronic hepatitis C who had relapsed or did not respond to a previous course of IFN. One-hundred and twenty patients (69 non-responders and 51 relapsers) were randomly assigned to receive IFN-alpha2b (3 million units thrice weekly) plus ribavirin (1,000-1,200 mg per day) for 24 weeks (group A: 58 patients) or 48 weeks (group B: 62 patients). Treatment was discontinued at week 12 if the alanine aminotransferase (ALT) level remained elevated. The rate of sustained response was 15.5% in group A and 37.1% in group B (P = 0.013). Relapsers treated for 48 weeks had a sustained response rate of 66.6% compared with a sustained response rate of only 25% in those treated for 24 weeks (P = 0.004). Moreover, a sustained response was seen in 14.3% of non-responders treated for 48 weeks and in 8.8% of those treated for 24 weeks (P = 0.71). Fifty-three per cent of patients with a normal ALT level and undetectable hepatitis C virus (HCV) RNA at week 12 had a sustained response compared with 14% of those who were HCV RNA positive at week 12 (P < 0.001). Independent predictive factors of sustained response were: therapy for 48 weeks (P = 0.0026), relapse after IFN treatment (P = 0.0006), loss of HCV RNA at week 12 (P = 0.0008) and HCV genotype non-1 (P = 0.024). Hence, in patients with chronic hepatitis C who failed to respond to a previous course of IFN monotherapy, combination therapy with IFN plus ribavirin for 48 weeks seems to be more effective than IFN plus ribavirin for 24 weeks.

Adult↗
PubMed1999

Biochemical liver abnormalities in Turner's syndrome.

BACKGROUND: Turner's syndrome is a chromosomal abnormality (45X0) which may be associated with various autoimmune disorders and disease conditions; however, association with liver pathology has rarely been reported. OBJECTIVES: The aim of this work was to assess liver function abnormalities in a group of adult patients with Turner's syndrome. DESIGN AND METHODS: Liver function tests were performed in 16 women with Turner's syndrome all of whom had been previously treated with oestrogens. Patients with liver abnormalities were further studied with hepatic ultrasonography, serological markers of viral hepatitis and autoantibody determinations. RESULTS: Seven women (43.7%) presented with asymptomatic liver cholestasis; these patients were older than those with normal biochemical values (33.4+/-5.2 vs 24.7+/-5.7 years, P<0.05). Liver function abnormalities appeared 7.8+/-4.9 years after starting oestrogen therapy; however, no improvement of liver function was observed 20+/-17.7 months after stopping treatment. All of these women were anti-HCV and HBsAg negative, and autoimmune hepatitis was ruled out in all cases. Liver ultrasound only disclosed homogeneous liver enlargement in one case and cholelithiasis without bile duct abnormalities in another. Four patients underwent a percutaneous liver biopsy of which two were normal and two showed minimal non-specific changes. CONCLUSIONS: The incidence of biochemical liver cholestasis in this group of patients with Turner's syndrome is high. Oestrogen therapy and autoimmune disorders do not seem to be the responsible causes. It appears that this is a benign condition which does not seem to reflect any substantial liver dysfunction. The aetiology remains uncertain.

Adult↗
PubMed1997

5alpha-reduction of norethisterone enhances its binding affinity for androgen receptors but diminishes its androgenic potency.

Norethisterone (NET), a 19-nor synthetic progestin, undergoes enzyme-mediated 5alpha-reduction and exerts potent androgenic effects in target organs. To investigate its mode of androgenic action we examined, in a comparative manner, the in vitro metabolism of NET and testosterone (T), as well as the binding affinities to androgen receptors (AR) and the androgenic potency of NET, T, and their 5alpha-reduced derivatives. Bioconversion of [3H]-NET and [3H]-T was studied in rat prostate homogenates, AR binding affinity was assessed in rat ventral prostates using [3H]-mibolerone as the radioligand, and the androgenic potency was evaluated by the increase of beta-glucuronidase activity in the mouse kidney, and by the growth of accessory sex organs in castrated male rats. The results demonstrated that 5alpha-NET displayed a higher AR binding affinity but a significantly lower androgenic potency than unchanged NET. The bioconversion studies indicated that the metabolism of NET was similar to that of T, although to a lesser extent, thus ruling out the possibility that the synthetic progestin metabolizes rapidly into less active derivatives. To investigate the nature of the paradoxical effect of 5alpha-reduction upon the NET molecule, the interaction with AR and the androgenic potency of T, 19-nortestosterone (19norT), 17alpha-ethynyl testosterone (ET) and their 5alpha-reduced derivatives were examined. The results of AR binding studies revealed that 5alpha-reduction of T and ET significantly enhanced their affinities, and that the 5alpha-derivative of 19norT displayed a similar binding affinity to that exhibited by 19norT. In terms of biological activity, the results showed that 5alpha-reduction of T and 19norT significantly increased their androgenic potency, whereas 5alpha-reduction of ET resulted in a significant diminution of its androgenicity in a manner similar to that observed with the 5alpha-reduction of NET. When NET and 19norT were simultaneously administered with 5alpha-dihydrotestosterone they exhibited a potent synandrogenic activity, an effect that was cancelled by their 5alpha-reduction. Interestingly, ET displayed an antiandrogenic activity, an effect that was also suppressed by its 5alpha-reduction. The overall results demonstrated a distinctive, paradoxical effect of 5alpha-reduction upon the NET molecule, which was different from that seen in naturally occurring androgens, and which suggests that the presence of the 17alpha-ethynyl group plays a key role in this phenomenon. The data provided further evidence that the metabolism of synthetic contraceptive progestins modulates the expression of their hormone-like actions.

Androgens↗
PubMed1996

Identification and androgen regulation of a 156-kDa hemeprotein in the harderian gland of the Syrian hamster.

An abundant cytosolic protein from hamster Harderian glands was partially purified by ultracentrifugation and analyzed on SDS-PAGE. This 156-kDa protein occurs in male but not in female glands. Castration of adult males for different time periods resulted in a gradual disappearance of the protein over 5 weeks. Daily administration of testosterone, 5 alpha-dihydrotestosterone, 3 alpha- or 3 beta-androstanediol (0.5 mg/day/15 days), to castrated males maintained the levels of the protein. In females, the protein was induced with the same compounds but not with 17 beta-estradiol. These observations indicate an androgen-mediated hormonal regulation. In developing animals, the 156-kDa protein was detectable in glands of 2-week-old males and females; it was not detected in 4-week-old females. Its specific reactions to 3,3',5,5'-benzidine derivatives strongly suggest heme groups associated with this Harderian gland protein.

Androgens↗
PubMed1995

Efficacy of screening donors for antibodies to the hepatitis C virus to prevent transfusion-associated hepatitis: final report of a prospective trial.

Routine screening of blood donors for anti-hepatitis C virus (HCV) has been implemented in most developed countries. However, the independent efficacy of such screening has not been established in a controlled, prospective study. We tracked 478 patients transfused with anti-HCV-negative blood by first-generation enzyme-linked immunoassay (EIA) between July 1989 and May 1990 and compared the incidence of transfusion-associated hepatitis and HCV infections with that found among 280 patients transfused with blood unscreened for anti-HCV during the immediately preceding year. Of the 280 patients who had received transfusions before donors were screened for anti-HCV, 27 (9.6%) developed posttransfusion hepatitis and 1 additional patient seroconverted to anti-HCV without evidence of hepatitis, for a risk of posttransfusion HCV infection of 10.7% (28 of 262 recipients seronegative for anti-HCV before transfusion). Of the 478 patients transfused after July 1989 with blood screened for anti-HCV, only 9 (1.9%) developed posttransfusion hepatitis for a risk reduction of 80%. Seven of the 9 residual cases of hepatitis were caused by HCV (7 of 456 recipients seronegative before transfusion or 1.5%) for a risk reduction of transfusion-associated HCV infection of 86%. In retrospect, an anti-HCV positive donor was detected by second-generation immunoassay in 4 (57%) of the 7 HCV cases from the study cohort and in 19 of the 23 (83%) cases from whom all donor samples were available for testing in the historical cohort. No additional infectious donors were detected by third-generation immunoassay or serum HCV-RNA by polymerase chain reaction.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Prevalence of thyroid autoantibodies is not increased in blood donors with hepatitis C virus infection.

Serum autoimmune reactions are found in many patients with hepatitis C. A high prevalence of thyroid dysfunction and antithyroid antibodies in patients with chronic hepatitis C was recently reported. We have compared the prevalence of thyroid dysfunction and antithyroid peroxidase antibodies in blood donors with hepatitis C virus (HCV) infection (study group) and in seronegative anti-HCV donors (control group). One hundred and ninety-two blood donors were studied: 96 were anti-HCV positive by ELISA 2 (48 males and 48 females; age 48 +/- 12.9 years, mean +/- SD), and 96 were HCV seronegative (55 males and 41 females; age 37 +/- 14.8 years). In all patients, serum TSH (0.25-4.2 mU/l) and fT4 (9-23 pmol/l) were measured by immunochemiluminiscent assays and antithyroid peroxidase antibodies (normal < 100 U/ml) by RIA. In all anti-HCV positive donors, hepatitis C viremia was tested using the nested polymerase chain reaction. Thyroid dysfunction was found in three females (3.1%) in the anti-HCV positive group (three cases of hypothyroidism), and in four (4.1%) anti-HCV negative blood donors (three cases of hypothyroidism, two females and one male; one case of hyperthyroidism, a female), (p = NS). Antithyroid peroxidase antibody titers were above normal values in 5 (5.2%) anti-HCV positive individuals and in eight (8.3%) anti-HCV negative blood donors (p = NS). These results do not show an increase prevalence of thyroid dysfunction and antithyroid peroxidase antibodies in blood donors with HCV infection when compared with a control group.

Adult↗
PubMed1995

Comparative study of two high doses of lymphoblastoid interferon in the treatment of chronic hepatitis C: influence on the levels of ALT, viraemia and histologic activity.

Ninety consecutive patients with chronic hepatitis C were included in a randomized, uncontrolled trial to compare the efficacy of two treatment regimens, 10 MU (group A) vs 5 MU (group B), of lymphoblastoid interferon, in a step-down schedule for 24 weeks. All of the patients had antibodies against the hepatitis C virus, and all but one were HCV RNA positive in serum. The origin of the infection was attributed to blood transfusion in 30 patients and classified as sporadic in 60 patients. During treatment reduction in the ALT levels as well as the elimination of viraemia was observed in both treated groups, although these changes did not correlate significantly with the interferon dose. Nine months after the end of therapy, a sustained response was achieved in 13.6% (12/88) of the patients. Relapse in group B (87.5%) was significantly higher than in group A (59.1%). The percentage of cases which remained with undetectable HCV RNA was significantly higher for the sustained responders (66.7%) than for the non-responders (11.8%) and relapser patients (2.4%). Repeated liver biopsies showed an overall significant reduction of all the subindices of histological activity from patients with sustained response, except for fibrosis. In short: the 10 MU dosing regimen of lymphoblastoid interferon was as efficient as the 5 MU dose as it brought about a similar improvement in ALT levels, histological activity and elimination of viraemia, albeit 10 MU proved significantly more effective in the prevention of a relapse among the responders after 24 weeks therapy.

Adult↗
PubMed1994

Demonstration of HCV-RNA and HBV-DNA in the serum of HBsAg negative patients with hepatocellular carcinoma.

Forty patients with chronic liver disease and HCC were analyzed for infection with hepatitis C (HCV) and hepatitis B (HBV) viruses. All patients were negative for HBsAg, 16 were alcoholics, 6 had previous blood transfusions and 18 had sporadic chronic hepatitis. Antibodies to HCV were determined by EIA 2nd generation. HBV-DNA was detected by PCR using primers of the precore region. Analysis of HCV-RNA was done with nested PCR amplifying the 5' non-coding region of the HCV genome, using primers complementary to nucleotides 1-20 and 305-320 and nested primers complementary to nucleotides 21-31 and 271-286 of the HCV-J1. Anti-HCV were positive in 35/40 patients (87.5%). HCV-RNA was detected by PCR in 34 patients (85%) all of them positive for the anti-HCV. HCV-RNA was detected in 70.5% of the alcohol abusers, in 100% of patients with history of transfusion(s) and 94.1% of patients with cryptogenic chronic liver disease. HBV-DNA was detected in only 2 patients. In conclusion, there is a high rate of HCV and a low rate of HBV viremia detected by PCR in Spanish patients with HCC HBsAg negative. No patient without anti-HCV presents HCV-RNA. Our results suggest that persistent HCV replication may play a role in hepatic carcinogenesis, as HBV-DNA could be found in only 5% of our HCC patients.

Aged↗
PubMed1994

Controlled trial of tamoxifen in patients with advanced hepatocellular carcinoma.

Thirty-six consecutive patients with advanced hepatocellular carcinoma and chronic liver disease were randomly allocated to two groups: group I included 20 patients who were treated with 10 mg bid. tamoxifen and group II with 16 non-treated patients. The two groups were homogeneous according to clinical and analytical data. Survival curves in the tamoxifen-treated patients improved significantly when compared with the non-treated group (p = 0.01). Cumulative survival at the end of the first year was 48.5% in the treated patients and 9.1% in controls. Median survival was 261 days in the treated group vs. 172 in the non-treated group (p < 0.05). Complications of cirrhosis and worsening of the performance status test occurred less in the treated patients than in the controls, but not significantly so. Tamoxifen was well tolerated and no marked side effects were observed. In this series, tamoxifen improved survival in patients with advanced hepatocellular carcinoma.

Aged↗
PubMed1994

Alcohol dehydrogenase from human stomach: variability in normal mucosa and effect of age, gender, ADH3 phenotype and gastric region.

Alcohol dehydrogenase (ADH) has been analysed in 36 endoscopic biopsies of normal gastric body and/or antrum mucosa, from 31 individuals with an age between 17 and 79 years. Oesophageal, duodenal and oral mucosa specimens have been also examined. Stomach mucosa contains three isozyme types: the gamma gamma-ADH forms (class I), sigma sigma-ADH (class IV) and chi chi-ADH (class III). gamma gamma-ADH was present in all gastric samples, while sigma sigma-ADH was detected in all body specimens (n = 15) but only in eight of 20 antrum biopsies. The presence of high sigma sigma-ADH activity in oral and oesophageal mucosa confirms the distribution of class IV in the upper gastrointestinal tract where it may serve as a first metabolic barrier against ingested alcohols and aldehydes. Considering all gastric specimens, ADH activity was 5.78 +/- 2.61 mU/mg of protein with 100 mM ethanol, pH 10.0. ADH activity was higher in men than women and in gastric body than in antrum, although differences did not reach statistical significance. However, activity was significantly higher in subjects below 50 years than those older than 50 years. Furthermore, an inverse correlation was found between gastric ADH activity and age (r = -0.40, P < 0.02). In old subjects ADH activity was significantly higher in gastric body (5.87 +/- 1.22 mU/mg) than in antrum (4.14 +/- 1.78 mU/mg) (P = 0.03). Differences in activity between samples from each ADH3 phenotype were statistically not significant but corresponded to those expected from the kinetic constants of the respective gamma gamma-ADH isozymes, which suggests that ADH3 polymorphism affects activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

[Value of ultrasonography in the early diagnosis of hepatocellular carcinoma].

The size and the treatment of 135 hepatocellular carcinomas (HCC) has been analyzed, comparing patients diagnosed by a US screening program (group 1) and these diagnosed outside this program (group 2) to determine whether US screening on patients with chronic liver disease is able to diagnose (HCC) at an early stage. alpha-fetoprotein levels above 500 U/ml were considered as diagnostic. Twenty (46.5%) out of 43 patients from group 1 showed a HCC < 5 cm. vs. 14/92 (15.2%) in group 2 (p = 0.001). Only 5.9% of the HCC < 5 cm. showed AFP > 500 U/ml. vs. 29.7% of the advanced HCC (p = 0.003). 88.3% of patients of group 1 vs. 63% of group 2 received specific treatment for HCC (p = 0.002). By means of US screening it is possible to diagnose HCC of smaller size and more susceptible to treatment. AFP is not useful in the early diagnosis of HCC.

Aged↗
PubMed1993

[Thorotrast-related hepatosis].

The clinical, pathological and laparoscopic data of five patients with liver disease due to Thorotrast are presented. Laparoscopy showed various degrees of fibrosis and nodularity. One patient developed cholangiocarcinoma and two showed dysplasia at biopsy. The laparoscopic appearance is practically diagnostic.

Adenoma, Bile Duct↗
PubMed1993

[Splenic rupture in the course of pancreatitis].

We present the case of a young patient with a history of alcoholism and chronic relapsing pancreatitis, who developed an associated pseudocyst. During the course of the disease he presented an acute abdomen due to splenic rupture and splenic thrombosis, disclosed by laparotomy. Following splenectomy and drainage the evolution was satisfactory. In the present paper we discuss the presentation of splenic vein thrombosis and splenic rupture as a rare complication of pancreatic pseudocyst.

Adult↗
PubMed1992

Mechanisms of hormonal and antihormonal action of contraceptive progestins at the molecular level.

19-Nor synthetic progestins undergo extensive metabolism at the target cells. The resulting metabolic conversion products interact with putative steroid receptors within the cells, and through those interactions, they may exert either agonistic, synergistic and antagonistic hormonal effects. Studies conducted in our laboratories have disclosed that norethisterone (NET) and D-(1) norgestrel (LNG), two widely used contraceptive progestins, are biotransformed to several A-ring reduced (dihydro and tetrahydro) derivatives. The resulting metabolites 5 alpha-dihydro NET (5 alpha-NET) and 5 alpha-dihydro LNG bind with relative high affinity to the progesterone and androgen receptors. To gain insight into the underlying molecular events mediating the mode of action of NET and its neutral metabolites, we have examined the expression of their biological effects at target organs by using the rabbit uteroglobin gene model and the beta-glucuronidase activity of the mouse kidney. The results of a series of experiments seem to indicate that the enzyme-mediated formation of the 5 alpha (trans A/B ring junction) NET derivative results in a significant diminution of its progestational and androgenic potencies. Furthermore, 5 alpha-NET acquire a potent anti-progestational/contragestational effect as assessed in the female rabbit. These results demonstrated that 5 alpha-reduction of 19-nor progestins exerts a paradoxical effect, at least in terms of their hormone-like effects. The overall data are in line with the concept that metabolism of synthetic progestins at hormone-sensitive organs modulates their mechanisms of action.

Animals↗