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Biomedical subjects

D Nicolás

Publications and source records attributed to D Nicolás.

At least 19 recordsLinked to original sources
PubMed2001

De novo hepatitis B after liver transplantation from hepatitis B core antibody-positive donors in an area with high prevalence of anti-HBc positivity in the donor population.

Transmission of hepatitis B virus (HBV) infection from donors who are negative for hepatitis B surface antigen (HBsAg-) but positive for antibody to hepatitis B core antigen (anti-HBc+) has been reported. However, previous studies were generally performed in geographic regions with a low prevalence of anti-HBc positivity in the liver donor population. The aims of this study are (1) to assess the risk for de novo hepatitis B in recipients of livers from anti-HBc+ donors in an area of high prevalence of anti-HBc positivity in the donor population, and (2) to analyze the risk factors for acquisition of HBV infection from anti-HBc+ donors. The transplantation experience of a single center between 1995 and 1998 was reviewed. Thirty-three of 268 liver donors (12%) were HBsAg- and anti-HBc+ during the study period. The proportion of anti-HBc+ donors increased with age; it was lowest (3.6%) in donors aged 1 to 20 years and highest (27.1%) in donors aged older than 60 years. Of the 211 HBsAg- recipients with 3 months or more of HBV serological follow-up, 30 received a liver from an anti-HBc+ donor and 181 received a liver from an anti-HBc- donor. Hepatitis B developed in 15 of 30 recipients (50%) of livers from anti-HBc+ donors but in only 3 of 181 recipients (1.7%) of livers from anti-HBc- donors (P < .0001). None of the 4 recipients who were antibody to HBsAg (anti-HBs)+ at the time of transplantation developed HBV infection after receiving a liver from an anti-HBc+ donor compared with 15 of 26 recipients (58%) who were anti-HBs- (P =.10). None of the 5 anti-HBc+ recipients developed hepatitis B compared with 15 of 25 anti-HBc- recipients (60%; P = 0.04). Child-Pugh score was significantly higher in recipients of livers from anti-HBc+ donors who developed HBV infection than in those who did not (9 +/- 2 v 7 +/- 1; P =.03). In our area, testing liver donors for anti-HBc is mandatory, particularly in older donors. With such information available, anti-HBc+ donors can be safely directed to appropriate recipients, mainly those with anti-HBs and/or anti-HBc at the time of transplantation. In the current era of donor shortage, this policy would allow adequate use of such donors.

Adolescent↗
PubMed2001

Are posttransplantation protocol liver biopsies useful in the long term?

Controversy exists about the usefulness of yearly protocol liver biopsies after liver transplantation, mainly among patients with normal transaminase levels. The aim of this study is to determine (1) the prevalence and cause of histological liver injury in transplant recipients with a minimum histological follow-up of 1 year (n = 254), and (2) the correlation between histological findings and transaminase values. The main indication for liver transplantation was viral-related cirrhosis (61%; 86% caused by hepatitis C virus [HCV]). Protocol liver biopsies were performed yearly for the first 5 years in HCV-infected transplant recipients and at 1 and 5 years in the remaining patients. Histological liver injury included several categories of liver damage (hepatitis, rejection, steatohepatitis, cholangitis, and Budd-Chiari-like lesions). Among biopsy specimens categorized as hepatitis, severe hepatitis was defined as the presence of stage 3 or greater fibrosis. The prevalence of liver injury increased significantly with time (42% v 56% at 1 and 5 years, respectively; P =.09) and was significantly greater in patients who underwent transplantation for HCV-related cirrhosis than in those who underwent transplantation for other reasons (P =.0001). The most frequent category of liver injury was hepatitis (97% and 96% at 1 and 5 years, respectively). Although a proportion of patients with liver injury (12% to 29%) had normal transaminase values, this percentage was almost null in patients with severe hepatitis. Normal histological characteristics were found in the vast majority of non-HCV-infected transplant recipients with normal transaminase values. Given the high prevalence of abnormal histological findings, particularly the increase over time of those defined as severe, protocol liver biopsies are clearly justified in HCV-infected transplant recipients. Conversely, given the rarity of abnormal histological findings, protocol liver biopsies should be questioned in non-HCV-infected transplant recipients with normal transaminase values.

Adult↗
PubMed2000

[ROC curve analysis of factors predictive of non-response to interferon treatment in patients with chronic hepatitis C, genotype 1].

The objectives of this study included: 1) to identify pretreatment variables predictive of absence of response in 107 patients with chronic hepatitis C, genotype 1, treated with interferon-a (IFN-a) at a dose of 3 MU three times weekly for 3-12 months and classified into two groups: group A, nonresponders vs. patients with a complete response, and group B, nonresponding and relapsing patients vs. patients with a sustained response; and 2) to establish a prognostic index using ROC curve analysis. The rate of sustained response was 6. 5% at the 24-month follow-up. The pretreatment characteristics with predictive value using ROC curves were as follows: in group A, age, GGT, serum ferritin, viral load, and grade and stage of the histological lesion; and in group B, known duration of infection, GPT, GGT, serum ferritin, viral load, and grade and stage of the histological lesion. In both group A and group B the positive predictive value (the probability of predicting an absence of response when the variable is present) was greater than the negative predictive value (mean: 84.3% vs. 41.1%, 99% vs. 16.5%, respectively). In group A, based on the prognostic index, the positive predictive value when three variables were present was 96% and the sensitivity was 63.5%, with the test being unequivocal in 6.5%, whereas when four or five variables were present, the positive predictive value was 97% and 100% and the sensitivity was 40.5% and 18%, respectively. In group B, the positive predictive value when two variables were present was 100% and the sensitivity was 87%, whereas when three, four, five and six variables were present the sensitivity was between 73% and 28%. In group A, age, GGT and ferritin were the predictive variables independently associated with an absence of response, with a relative risk of 6.5, 4.8 and 3.1, respectively, whereas in group B we did not find variables independently associated with an absence of response. It was concluded that in patients with genotype 1, it is possible to predict the absence of response to IFN therapy with a high degree of reliability.

Adolescent↗
PubMed2000

[ROC curve analysis of factors predictive of no response to interferon treatment in patients with chronic hepatitis C, genotype 1]

The objectives of this study included: 1) to identify pretreatment variables predictive of absence of response in 107 patients with chronic hepatitis C, genotype 1, treated with interferon-a (IFN-a) at a dose of 3 MU three times weekly for 3-12 months and classified into two groups: group A, nonresponders vs. patients with a complete response, and group B, nonresponding and relapsing patients vs. patients with a sustained response; and 2) to establish a prognostic index using ROC curve analysis. The rate of sustained response was 6.5% at the 24-month follow-up. The pretreatment characteristics with predictive value using ROC curves were as follows: in group A, age, GGT, serum ferritin, viral load, and grade and stage of the histological lesion; and in group B, known duration of infection, GPT, GGT, serum ferritin, viral load, and grade and stage of the histological lesion. In both group A and group B the positive predictive value (the probability of predicting an absence of response when the variable is present) was greater than the negative predictive value (mean: 84.3% vs. 41.1%, 99% vs. 16.5%, respectively). In group A, based on the prognostic index, the positive predictive value when three variables were present was 96% and the sensitivity was 63.5%, with the test being unequivocal in 6.5%, whereas when four or five variables were present, the positive predictive value was 97% and 100% and the sensitivity was 40.5% and 18%, respectively. In group B, the positive predictive value when two variables were present was 100% and the sensitivity was 87%, whereas when three, four, five and six variables were present the sensitivity was between 73% and 28%. In group A, age, GGT and ferritin were the predictive variables independently associated with an absence of response, with a relative risk of 6.5, 4.8 and 3.1, respectively, whereas in group B we did not find variables independently associated with an absence of response. It was concluded that in patients with genotype 1, it is possible to predict the absence of response to IFN therapy with a high degree of reliability.

Journal Article↗
PubMed2000

[Comparison of the efficacy of cleaning and disinfection of videoscopes: mechanized versus manual].

AIM: a) To analyze the effectiveness of the automated cleaning and disinfection of endoscopies (Olympus miniETD, not previously tested) versus the manual method; b) To evaluate the drying and storage procedures used in our unit. MATERIAL AND METHODS: Prospective 10-day study. The endoscopies were randomized for automated or manual cleaning and disinfection. Endoscopic samples were collected for microbiology studies at three points during the process: a) after endoscopy (after manual cleaning with water), b) after cleaning with enzymatic detergent and disinfection (automated or manual) and c) at the first hour in the morning. RESULTS: Sixty-five samples were collected after endoscopy: 26 from gastroscopy, 26 from colonoscopy and 13 from duodenoscopy (positive cultures were found in 22, 25 and 10, respectively). The 35 samples collected after automated disinfection were negative, as were 29 of the 30 collected after manual disinfection (p = 0.46). Sixty-four of the 65 samples were negative for hepatitis B and hepatitis C. The only sample positive for hepatitis C became negative after manual disinfection. Positive culture was found in 15% of the samples collected before beginning the session. CONCLUSIONS: a) Automated cleaning and disinfection (Olympus miniETD) are as effective as manual cleaning. b) Drying and storage procedures should be improved and/or disinfection should be carried out again before the first endoscopy of each session.

Colonoscopes↗
PubMed1999

[Severe lower digestive hemorrhage in Crohn's disease].

Severe or massive lower gastrointestinal bleeding is an unusual complication of inflammatory bowel disease that has traditionally associated with ulcerative colitis, although it can also appear in 0.6-2% of the cases in Crohn's disease. Two cases of severe lower gastrointestinal bleeding in Crohn's disease, one of them with ileocolic and another with ileal involvement are presented. Surgical treatment is supported by potential severity, high frequency of the relapse and data indicate a good prognosis after intestinal resection. It can be performed immediately if the persist bleeding or elective, as the 2 cases that we present, in the patients that are stabilized.

Acute Disease↗
PubMed1999

[Carcinoid syndrome: advances in diagnosis and treatment].

Carcinoid is the most common endocrine digestive tumor. The carcinoid syndrome resulting from the variety of amines and peptides produced by this tumor is usually apparent once there are metastases to the liver. Tumors with direct systemic venous drainage seldom produce a carcinoid syndrome without the presence of liver metastasis. This may occur because the hormone escapes the normal metabolic pathway (monoamine oxidase) in the liver. The most significant and important advance in diagnosis for tumor localization has been the introduction of scintigraphy using 111In-labeled octreotide. Current management of carcinoid syndrome should consider the spontaneous course of the disease and the severity of clinical symptoms, and includes different therapeutic options as hepatic resection, chemoembolization, medical treatment with the long-acting analogues of somatostatin and liver transplantation.

Digestive System Neoplasms↗
PubMed1999

[Digestive alterations in cystic fibrosis. Retrospective study of a series of 46 adult patients].

The clinical histories of 46 adult patients (24 men and 22 women, mean age 20.6 +/- 5.1 years) diagnosed of cystic fibrosis were reviewed evaluating the digestive alterations. The age at diagnosis of cystic fibrosis was 5.63 +/- 5.3 years (range: newborns-19 years). The initial diagnosis was established by ileus meconium, in four, lung disease in 15, steatorrhea in 12, lung disease and steatorrhea in 13 and following the diagnosis of cystic fibrosis in siblings in two. Four patients presented ileus meconium, nine occlusive syndrome of the distal intestine, 42 steatorrhea (20 severe, 12 moderate and 10 mild), with the severity of the steatorrhea not being associated with the severity of the respiratory insufficiency. Two patients presents rectal prolapse, five gastroesophageal reflux syndrome (four with hiatal hernia), six cholelithiasis, one recurrent pancreatitis without detection of biliary lithiasis, one neonatal cholestasis and 10 malnutrition (five severe and five moderate) fundamentally in relation to the severity of the lung disease and, to a lesser degree, liver disease. In 10 patients chronic liver disease was diagnosed corresponding to established cirrhosis in seven, indicating liver transplantation in two. In most cases, the liver disease was already manifest in adolescence even in the cirrhotic stage. Cholangiography by magnetic resonance was useful in the study of liver disease showing abnormalities which imitated primary sclerosing cholangitis. Treatment with ursodesoxicholic acid at a dosis of 20 mg/kg/day led to a significant decrease in the transaminase values and overall of gammaglutamyltranspeptidase but did not avoid complications in the cirrhotic stages. Genetic studies performed in 36 patients detected the delta F508 mutation in 69.4%, being found in almost all of the patients with ileus meconium, occlusive syndrome of the distal intestine, liver disease, cholelithiasis and malnutrition.

Adult↗
PubMed1999

[Acute hepatitis due to heatstroke].

The hepatic injury is a nearly constant event in the course of a heatstroke, which rarely evolves to a severe liver failure. In these cases, the patient's survival is conditioned to an early treatment and, sometimes, an orthotopic liver transplantation is needed. We report a case of severe acute hepatitis in a 17-year-old man, due to a heatstroke during a vigorous exercise in a training program. High ambient temperature and a long time without training predisposed to the development of heatstroke in this patient. Outcome was favourably, with a total recovery in a few weeks.

Acute Disease↗
PubMed1991

[Prevalence of antibodies against the hepatitis C virus among the staff of a general hospital].

The prevalence of antibodies against hepatitis C virus (HCV) in 413 hospital staff (57% total staff) was 1.7%. There were no significant differences in the sanitary workers (physicians, nurses and assistants of clinic and laboratory) versus cleaners, office and other non-sanitary workers of hospital staff. The seropositivity to HCV was not related to sex, age, years in occupation and the prevalence of hepatitis B virus serological markers. This relatively low prevalence let suppose than the hospital staff is not a high risk group for HCV infection.

Female↗
PubMed1991

[Serology against Toxoplasma gondii in pregnant women. Development of prevalence rates in the course of 4 years].

Sera from 1,221 pregnant women were screened for antibodies against Toxoplasma gondii. The prevalence rate of antibodies was 38.9%. We have observed specific IgM antibodies 15 pregnant women (1.2%). The prevalence rate was not increased significantly with the age and number of pregnancies. The seropositivity was reduced significantly in the 4th year studied. The high rate of seronegativity observed in the pregnant women represent a high risk of Toxoplasma infestation.

Antibodies, Protozoan↗