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Biomedical subjects

J Córdoba

Publications and source records attributed to J Córdoba.

At least 37 records · Page 2Linked to original sources
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

Receiver operating characteristics curve analysis of factors predictive of nonresponse to interferon therapy in patients with chronic hepatitis C.

OBJECTIVES: 1) to identify pretreatment variables predictive of nonresponse to interferon-alpha (IFN-alpha) in patients with chronic hepatitis C, and 2) to establish a prognostic index in these groups using receiver operating characteristics curve analysis. METHODS: 132 patients were treated with IFN-alpha at a dose of 3 megaunits three times a week for 3-12 months. The response was compared in patients with a complete response vs nonresponders, and patients with a sustained response vs nonresponders plus relapsers. Factors predictive of response were identified by analyzing clinical, biochemical, virological and histological variables. RESULTS: The sustained response rate was 12.8% at 24 months of follow-up. The pretreatment characteristics with a predictive value (PV) according to area under the ROC curve and 95% confidence interval > 0.5 were age, known duration of infection, history of transfusion, GGT, serum ferritin levels, viral load, genotype, and grade and stage of the histological lesion. The positive PV (the probability of predicting absence of response when the variable is present) was notably greater than the negative PV (mean: 94.9% vs 24.8%, respectively). In addition, when 4 and 6 variables were present, the positive PV was 100% and sensitivity was 60.2% and 22.1%, respectively. The predictive variables independently associated with an absence of response were genotypes 1, 4 and 5, GGT > 24 IU/l and grade of the histological lesion > 6. CONCLUSIONS: It was possible to predict the absence of both primary and posttreatment response with an acceptable degree of reliability.

Adult↗
PubMed1999

High incidence of allograft cirrhosis in hepatitis C virus genotype 1b infection following transplantation: relationship with rejection episodes.

The natural history of hepatitis C virus (HCV) infection following liver transplantation and predictors of disease severity remain controversial. The aims of the study were to assess in a homogeneous population of 81 cyclosporine-based HCV-infected liver transplant recipients mostly infected with genotype 1b and undergoing strict protocol annual biopsies: 1) the histological progression of posttransplantation HCV disease and, in particular, the incidence of HCV-related graft cirrhosis within the first 5 years after surgery; and 2) the relationship between progression to cirrhosis and i) rejection episodes and ii) first-year liver biopsy findings. We studied 81 consecutive HCV-RNA-positive patients (96% genotype 1b) undergoing liver transplantation between 1991 and 1996 with a minimum histological follow-up of 1 year. All patients received cyclosporine-based immunosuppression and underwent protocol yearly liver biopsies for the first 5 years. The mean histological follow-up was 32 months (range, 12-60 months). Biopsies were scored according to the histological activity index (HAI), with separate evaluation of grade (activity) and stage (fibrosis). Histological hepatitis, present in 97% of patients in the most recent biopsy, was moderate or severe in 64%. Twelve patients developed HCV-related cirrhosis at a median time of 24 months (range, 12-48 months), with an actuarial rate of HCV-cirrhosis of 3.7%, 8.5%, 16%, 28%, and 28% at 1, 2, 3, 4, and 5 years, respectively. Rejection was significantly more common among patients with cirrhosis versus those without (83% vs. 48%; P =.02), with an association between the incidence of cirrhosis and the number of rejection episodes: 5%, 15%, and 50% in patients without rejection, one and two episodes, respectively (P =.001). The degree of activity and fibrosis score in the first-year biopsy were higher in patients who developed cirrhosis than in those who did not (P =.008 and.18, respectively). In conclusion, HCV genotype 1b-infected liver recipients are at a high risk of developing graft cirrhosis in the first 4 to 5 years following transplantation, especially those with previous rejection episodes. First-year liver biopsies may help to sooner identify patients at the highest risk, improving further patient management.

Adult↗
PubMed1999

Mild hypothermia modifies ammonia-induced brain edema in rats after portacaval anastomosis.

BACKGROUND & AIMS: The pathogenesis of brain edema in fulminant hepatic failure is still unresolved. Mild hypothermia (33 degrees-35 degreesC) can ameliorate brain edema after traumatic brain injury. We evaluated mild hypothermia in a model of ammonia-induced brain edema in which accumulation of brain glutamine has been proposed as a key pathogenic factor. METHODS: After portacaval anastomosis, anesthetized rats were infused with ammonium acetate at 33 degrees, 35 degrees, and 37 degreesC or vehicle at 37 degreesC. Water and glutamine levels in the brain, cardiac output, and regional and cerebral hemodynamics were measured when intracranial pressure increased 3-4-fold (ammonia infusion at 37 degrees) and matched times (other groups). RESULTS: Mild hypothermia reduced ammonia-induced brain swelling and increased intracranial pressure. Brain glutamine level was not decreased by hypothermia. Brain edema was accompanied by a specific increase in cerebral blood flow and oxygen consumption, which were normal in both hypothermic groups. When the ammonia infusion was continued in hypothermic rats, plasma ammonia levels continued to increase and brain swelling eventually developed. CONCLUSIONS: Mild hypothermia delays ammonia-induced brain edema. In this model, an increase in cerebral perfusion is required for brain edema to become manifest. Mild hypothermia could be tested for treatment of intracranial hypertension in fulminant hepatic failure.

Acetates↗
PubMed1999

Antibacterial and antifungal effects of soft contact lens disinfection solutions.

AIMS: To study the antibacterial and antifungal effects of soft contact lens disinfection solutions. METHODS: Eight contact lens disinfection solutions containing hydrogen peroxide or biguanides or polyquad compounds were evaluated with respect to their ability to disinfect a saline solution experimentally contaminated with different bacteria and with a fungus. We used cultures in blood Agar, MuellerHinton agar and Saboureaud's agar to identify the bacterial and fungal growth following 14 h of exposure to the disinfection solutions. RESULTS: Hydrogen peroxide, DYMED and polyhexamide solutions prevented the growth of the four bacteria studied. The solution containing biguanide prevented the growth of Escherichia coli and Staphylococcus epidermidis. The solution with polyquad solution only prevented the growth of Staphylococcus epidermidis and none of the disinfection solutions prevented the growth of Candida albicans. The control solution, which was saline, did not prevent the growth of either bacteria or fungi. CONCLUSIONS: Disinfection solutions containing hydrogen peroxide, or DYMED or polyhexamide can disinfect these four bacteria but none of them prevented the growth of Candida albicans.

Journal Article↗
PubMed1999

Value of the polymerase chain reaction assay in noninvasive respiratory samples for diagnosis of community-acquired pneumonia.

We studied the causes of community-acquired pneumonia (CAP) in 184 patients. Microbiologic evaluation included sputum examination, blood culture, assessment of acute and convalescent antibody titers for Legionella pneumophila, Mycoplasma pneumoniae, Chlamydia pneumoniae, Coxiella psitacci, Coxiella burnetii and respiratory viruses, polymerase chain reaction (PCR) assays for M. pneumoniae and C. pneumoniae in throat swab, and PCR assay based on the amplification of pneumolysin gene fragment in sera. The causative pathogen was identified in 78 patients (Streptococcus pneumoniae, 44; M. pneumoniae, 26; C. pneumoniae, 1; others, 7). S. pneumoniae was detected in serum by the PCR assay in 41 patients, five of whom also had a positive blood culture. PCR assay was negative in two patients with positive blood culture for S. pneumoniae. C. pneumoniae was detected by PCR in nine patients, but only one showed seroconversion. M. pneumoniae was detected by PCR in only three patients (two without seroconversion). The diagnosis of pneumonia caused by S. pneumoniae was five times greater using PCR in serum than with blood culture. Detection of C. pneumoniae by PCR without fulfilling criteria for acute infection may be considered a prior infection. The PCR assay for the diagnosis of M. pneumoniae has a lower sensitivity than serologic methods.

Adolescent↗
PubMed1999

[The effect of iron depletion on the response to interferon treatment in patients with chronic hepatitis C. Pilot study].

UNLABELLED: It has been reported that increase in serum ferritin levels and/or in hepatic iron content is associated with a poor response to interferon treatment in patients with chronic hepatitis C (CH-C). AIM: To determinate whether iron depletion by phlebotomy (PB) increases the response to interferon therapy in chronic hepatitis C. PATIENTS AND METHODS: We have evaluated 12 patients with CH-C (genotype 1b = 11, 1a = 1), increased ALT levels, positive serum VHC-RNA and increased serum ferritin levels (> 220 ng/ml), including 8 previously non responders to interferon therapy and 4 naive subjects. Phlebotomies were performed weekly (mean number per patient: 6, range: 5-12) until serum ferritin levels were < 100 ng/ml, followed by interferon treatment (3MU thrice weekly for 3-12 months depending on the response). RESULTS: Multiple regression analysis showed that serum ferritin levels were not related to serum ALT levels (p = 0.18) or viral load (p = 0.06). Serum ALT levels decreased significantly post-PB (58 U/l, range: 35-141 U/l) as compared to pretreatment levels (164 U/l, range: 51-216 U/l, p < 0.006) and normalized in two subjects. HCV-RNA was positive in one of the latter and negative in the other. Eleven of the twelve patients did not respond to interferon after three months of therapy (increased serum ALT levels in 10 subjects and positive HCV RNA in 11). One additional patient, who had not been treated previously with interferon and had low pretreatment viral load, had a sustained response after 12 months of interferon therapy. Viral load did not decreased either with PB or following interferon treatment. By contrast, serum ferritin levels did not increase with interferon treatment or during the 6 month follow-up period. CONCLUSIONS: Decreasing serum ferritin levels by phlebotomies does not increase HCV erradication rate after interferon treatment. Sustained response to interferon therapy is an infrequent event and is more dependent on viral factors (viral load and genotype).

Adult↗
PubMed1999

Comparative analysis of quantification of viral load in patients infected with hepatitis C virus: quantiplex HCV RNA assay and amplicor monitor assay.

OBJECTIVE: two standardized techniques, Quantiplex HCV RNA 2.0 (bDNA) and Amplicor Monitor, were evaluated for the quantification of hepatitis C virus (HCV) load. Our objectives were: 1) to determine the relationship between viral load and genotype, and 2) to evaluate viral load in serial serum samples and in patients with normal or slightly elevated liver enzyme values in an area with a high prevalence of genotype 1. RESULTS: the viral loads detected with the two methods correlated significantly (r = 0.7, p < 0.0001), but viral load was smaller with the Monitor than with the Quantiplex assay, and was independent of genotype. The Monitor/Quantiplex ratio was lower in patients with a non-1 genotype than in patients with genotype 1b. Virological characteristics were similar in patients with normal or slightly elevated enzyme levels and in patients with elevated enzyme values. Neither method showed a relationship between viral load and age, sex, duration of the infection, mode of transmission, or histological activity index. CONCLUSION: viral load was not dependent on genotype. Measurement of viral load in a single serum sample adequately reflected the viral load measured in several serum samples from patients with chronic HCV infection. Patients with normal liver enzyme levels are not good candidates, in virological terms, for treatment with interferon.

Adolescent↗
PubMed1999

[Early prediction of lack of response to treatment with interferon and interferon plus ribavirin using biochemical and virological criteria in patients with chronic hepatitis C].

The objectives of this study were the following: 1) to evaluate the predictive value of the detection of RNA-HVC compared to GPT in the third month of treatment in patients with chronic hepatitis C treated with IFN, and at the first and third month in patients treated with IFN and ribavirin for 6 and 12 months. The study included: A) 80/132 patients treated with IFN (3 MU/3 times a week for 6-12 months), and B) 70/110 patients who had previously not responded to IFN, and who were treated with combination therapy (IFN: standard dose, ribavirin: 1200 mg/day) for 6 months (n = 40) and 12 months (n = 30). In group A, the positive predictive value (the probability of predicting the lack of response if the RNA-HVC was positive or if the GPT was elevated at the third month) was greater for RNA-HVC than for GPT (97.9% vs. 94.4%), although the response was not unequivocal (2.3% vs. 10.5%). The negative predictive value was 48.6% vs. 36.2%, respectively. The prediction level (odds ratio) of RNA-HVC and of GPT was 39.7 vs. 8.78 (p <0.000001 vs. p <0.002). The positive predictive value was 97.6% in patients with genotype 1, 4 and 5, and 100% in those with genotype 2 and 3. In group B, the positive predictive value was also greater for RNA-HVC than for GPT at the first month (100% vs. 94.4%) following six months of therapy, the odds ratio being infinite vs. 7.6. The positive predictive value was greater for RNA-HVC at the third month than at the first (100% vs. 91%), whereas it was similar for GPT (100%) with 12 months of therapy, the odds ratio being greater for GPT than for RNA-HVC at the first month (infinite and 7.27). The following was concluded: 1) detection of RNA-HVC at the third month of treatment with IFN predicts in advance a lack of response in patients, with a minimum risk of error; 2) in patients with six months of combined therapy, the detection of RNA-HVC at the first month is extremely reliable in the prediction of a lack of response, whereas after 12 months of combined therapy, elevated GPT values at the first month and the detection of RNA-HVC at the third are highly predictive of a lack of response.

Adolescent↗
PubMed1998

High prevalence of sleep disturbance in cirrhosis.

Sleep disturbance is a classic sign of hepatic encephalopathy. However, there are limited data regarding its prevalence in cirrhotic patients without overt hepatic encephalopathy. We assessed the characteristics of sleep in cirrhosis using a sleep questionnaire (n = 44) and actigraphy (n = 20). The results were compared with those of subjects with chronic renal failure and those of healthy controls. Presence of subclinical hepatic encephalopathy, chronotypology profile, and individual's affective state were also analyzed. The questionnaire indicated an elevated number of cirrhotic patients (47.7%) and patients with chronic renal failure (38.6%) who complained of unsatisfactory sleep compared with healthy controls (4.5%, P < .01). Actigraphy corroborated the deterioration of sleep parameters in cirrhotic patients with unsatisfactory sleep. The sleep disturbance in cirrhosis was not associated with clinical parameters nor with cognitive impairment. Cirrhotic subjects and patients with chronic renal failure with unsatisfactory sleep showed higher scores for depression and anxiety, raising the possibility that the effects of chronic disease may underlie the pathogenesis of sleep disturbance. However, in contrast to chronic renal failure, unsatisfactory sleep in cirrhosis was associated with delayed bedtime, delayed wake-up time, and evening chronotypology. In conclusion, a sleep disturbance is frequent in cirrhotic patients without hepatic encephalopathy and may be related to abnormalities of the circadian timekeeping system.

Activity Cycles↗
PubMed1998

Chronic hyponatremia exacerbates ammonia-induced brain edema in rats after portacaval anastomosis.

BACKGROUND/AIM: Abnormalities in brain organic osmolytes are associated with hepatic encephalopathy and with chronic hyponatremia. In spite of the high frequency of hyponatremia in acute and chronic hepatic failure, its role in the development of neurological complications in liver disease is poorly understood. We aimed to study the effect of prior hyponatremia on the development of ammonia-induced brain edema in rats after portacaval anastomosis. In this model, brain swelling is mediated in part through an increase in brain glutamine, an organic osmolyte. METHODS: Hyponatremia was induced in rats with 1-desamino-8-D-arginine vasopressin (DDAVP) administered through an osmotic minipump for 1 week. This was followed by performance of a portacaval anastomosis and ammonia infusion. At the end of the infusion, brain water (density gradient) and key brain organic osmolytes (HPLC) were measured. RESULTS: Rats with hyponatremia showed a decrease in all three brain organic osmolytes measured: glutamine, myo-inositol and taurine. Hyperammonemia resulted in the expected rise in glutamine, with a reduction of myo-inositol and taurine. In the combined group (hyponatremia plus hyperammonemia), the rise in brain glutamine induced by ammonia infusion was attenuated (10.6+/-0.9 mM/kg vs. 15.5+/-0.8 mM/kg hyperammonemia alone; p<0.05). In spite of this limited rise in brain glutamine, ammonia infusion to hyponatremic rats exacerbated brain swelling (82.3+/-0.3% vs. 80.6+/-0.1%; p<0.05). CONCLUSIONS: Hyponatremia worsens brain swelling in a model of ammonia-induced brain edema. The decrease in the concentration of brain organic osmolytes induced by hyponatremia does not protect the brain from the development of ammonia-induced brain edema.

Ammonia↗
PubMed1998

Early development of chronic active hepatitis in recurrent hepatitis C virus infection after liver transplantation: association with treatment of rejection.

BACKGROUND/AIMS: We retrospectively studied 63 consecutive patients (mean age 54+/-8) with hepatitis C virus genotype 1b recurrence after liver transplantation and with a minimum histological follow-up of 1 year, in order to determine whether an early severe recurrence, defined as the development of chronic active hepatitis within the first 2 years post-liver transplantation, was associated with increased immunosuppression. METHODS: The 1st year immunosuppression data (rejection episodes, boluses of methyl-prednisolone, cumulative doses of prednisone and azathioprine, OKT3 use) were recorded, and evaluated as predictive of severe recurrence at 1 and 2 years post-liver transplantation. Chronic active hepatitis and rejection were defined by histological criteria. Immunosuppression consisted of cyclosporine, azathioprine and prednisone. The treatment of rejection was based on a "bolus" of 1 g methyl-prednisolone/3 days. RESULTS: At 1 year, 64% (40/63) of the patients had chronic active hepatitis, whereas of the 40 patients who had a 2nd year biopsy available, 75% had chronic active hepatitis at 2 years. At 1 year post-liver transplantation, no significant association was observed between immunosuppression and the development of chronic active hepatitis. In contrast, at 2 years, rejection (p=0.006), treatment of rejection (p=0.05), methyl-prednisolone boluses (p=0.013) and the number of rejection episodes (p=0.0034) occurring during the 1st year post-liver transplantation were significantly more common in patients with chronic active hepatitis. There was also a trend towards higher cumulative steroids (9447+/-3176.5 vs 7891.5+/-2111 mg) and higher cumulative azathioprine doses (13472+/-11154 vs 6233.5+/-5937 mg) in patients with chronic active hepatitis as compared to those who did not develop chronic active hepatitis. CONCLUSIONS: Rejection and/or its treatment may accelerate the natural history of hepatitis C virus genotype 1b infection post-liver transplantation.

Alanine Transaminase↗
PubMed1998

[Evolution of resistance in the genus Enterococcus in strains isolated from blood].

The objective of this study was to determine the evolution of the species distribution and the prevalence of resistance to the Enterococcus genus. We studied 281 strains of enterococcus isolated from blood samples: 90 throughout 1984 and 791 from the years 1994 to 1996. identification was made using PosCombo 4Y Microscan-Baxter dehydrated panels and the Rapid ID 32 Strep system (bioMerieux). The MICs were calculated using the agar dilution method according to recommendations of the NCCLS for the following antibiotics: ampicillin, vancomycin, teicoplanin, gentamicin, kanamycin and streptomycin. The production of betalactamases were evaluated using a paper disk with nitrocefin for all the strains. The genotypes with resistance to glycopeptides were determined using PCR. The percentage of E. faecalis for 1984-1986/1994-1996 was 82.2/79.4; of E. faecium 4.4/16.4; and other species 12.214.3. The resistance to ampicillin went from 1.1% to 5.8%; high level resistance to glycopeptides went from 0% to 9.9%; for low level from 7.7% to 2.6%; resistance to a high charge of gentamicin went from 27.7% to 40.8%; and that for kanamycin from 45.5% to 62.8%. Resistance to streptomycin remained constant (45.5%). No strains produced betalactamases. For the species E. faecium, a statistically significant increase was detected for global resistance to ampicillin, gentamicin and kanamycin, with resistance to streptomycin remaining at similar percentages. No high level resistance to glycopeptides was detected in the first time period, but the low level resistance was greater.

Ampicillin Resistance↗