PubMed Health⌕ Search

Biomedical subjects

M Pardo

Publications and source records attributed to M Pardo.

At least 19 recordsLinked to original sources
PubMed1998

Quantitation of hepatitis C virus in liver and peripheral blood mononuclear cells from patients with chronic hepatitis C virus infection.

Since the natural history of hepatitis C virus-associated liver disease and the therapeutic responsiveness might vary according to liver and blood mononuclear cells viral levels, it may be important to quantitate viral RNA in liver, blood mononuclear cells and serum, and to compare these data with genotype, biochemical and histologic data. A polymerase chain reaction-based assay available for serum hepatitis C virus RNA quantitation has been optimized to quantitate viral genomes in liver and peripheral blood mononuclear cells from 47 chronic hepatitis C patients. The procedure permitted hepatitis C virus RNA quantitation in freshly isolated mononuclear cells and in total RNA extracted from frozen mononuclear cells and liver tissue. The intrahepatic viral amount (median: 2.6 x 10(3) copies/microgram RNA; range: 0 to 3.6 x 10(4) copies/microgram RNA) correlated significantly with the hepatitis C virus RNA concentration in serum (r = 0.76, P < .001), but not in mononuclear cells. Viral RNA concentrations in liver (P < .001), serum (P < 0.01) and PBMC (P < 0.05) were significantly higher in hepatitis C virus genotype 1 patients (essentially type 1b) than in non-1 type cases, but were unrelated to biochemical or histologic indexes of disease activity. In conclusion, the optimized assay permit HCV RNA quantitation in liver and peripheral blood mononuclear cells, suggesting that serum viral level is an accurate measurement of intrahepatic viral burden.

Adult↗
PubMed1998

Effects of the ribavirin-interferon alpha combination on cultured peripheral blood mononuclear cells from chronic hepatitis C patients.

The effects of ribavirin and interferon (IFN) alpha have been investigated on cultured peripheral blood mononuclear cells, obtained from 15 patients with chronic hepatitis C virus (HCV) infection. At clinically relevant serum concentrations achieved during therapeutic administration, ribavirin did inhibit moderately the mitogen-stimulated mononuclear cell proliferation and growth of the CD4+ and CD8+ T cell subsets without apparent cytolysis. The ribavirin-IFN-alpha combination showed activity against HCV with disappearance of HCV RNA in 27% of cases, and a synergy in the inducibility of the intracellular enzyme 2',5'-oligoadenylate synthetase. Such ribavirin concentrations induced modest increases in the T helper 1-like cytokine production by mononuclear cells. Higher ribavirin concentrations markedly inhibited IFN-gamma production, but augmented interleukins (IL) 2, 4, and 12 secretion. Conversely, IFN-alpha tended to suppress IL 2, 4 and 12, but enhanced IFN-gamma and IL-10 secretion. Thus, ribavirin and IFN-alpha appear to cause diverse effects on immunoregulatory cytokine secretion, and when combined, counteracted for production of IL-2 and IL-12, while upregulated mononuclear cell secretion of IFN-gamma and that of the anti-inflammatory cytokine IL-10. These findings suggest a non-cytolytic modulation of inflammatory responses induced by the drug combination, that may be relevant in the pathophysiology of chronic HCV infection.

2',5'-Oligoadenylate Synthetase↗
PubMed1998

Pharmacokinetics, antifolate activity and tissue distribution of PT523 in SCC VII tumor-bearing mice.

PURPOSE: To monitor the pharmacokinetics of PT523 and methotrexate in C3H mice with transplanted SCC VII tumors; to compare the impact of PT523 and methotrexate on tumor and normal host 5,10-methylenetetrahydrofolate levels; and to synthesize [14C]PT523 and determine its time-dependent tissue distribution in tumor and host tissues. METHODS: C3H mice bearing SCC VII tumors were given i.p. PT523 or methotrexate. Plasma drug levels and tumor, gut and marrow 5,10-methylenetetrahydrofolate were assayed. [14C]PT523 was synthesized and administered i.v. to tumor-bearing mice for tissue distribution analysis. RESULTS: Areas under the curve, mean residence times, whole body clearances, apparent distribution volumes, and plasma protein binding of PT523 vs methotrexate were, respectively, 4311 vs 6472 microM x min(-1); 20 vs 16 min; 0.56 vs 0.36 ml min(-1); 532 vs 325 ml x kg(-1); and 70% vs 30%. Both PT523 and methotrexate caused time-dependent declines in 5,10-methylenetetrahydrofolate in tumor and marrow, but not in gut mucosa [corrected]. Gut levels began to recover within 4 h in the PT523-treated group only. [14C]PT523 distributed mainly into the liver, duodenum, kidneys, lungs, tumor, pancreas and muscle; less into the spleen, blood cells, heart, brain and testicles; and very little into gut [corrected. Only 35% of the dose was excreted, and 2.9-fold more in feces than urine. CONCLUSIONS: Despite its more rapid clearance, accumulation of PT523 in extravascular tissues was greater than that of methotrexate. Consequently, less PT523 was recovered in feces and urine and its apparent volume of distribution was greater. PT523 selectively depleted 5,10-methylenetetrahydrofolate pools in tumor and, less persistently, in marrow, but spared the gut mucosa [corrected]. [14C]PT523 tissue distribution correlated with organ mass and blood supply.

Animals↗
PubMed1997

Decreased nitric oxide production in chronic viral hepatitis B and C.

Nitric oxide is a free radical gas molecule which may be implicated in antiviral defense. However, there is no information about its possible role in chronic viral hepatitis B and C. In this study we have analyzed the serum levels of NO2- (as an index of nitric oxide generation) from patients with chronic viral hepatitis B and C and relationship of same with the response to interferon therapy. Serum samples were analysed from 61 patients with chronic hepatitis B, 60 patients with chronic hepatitis C, 11 with chronic liver disease of nonviral origin, and 23 healthy controls. Levels of NO2- were statistically higher in healthy controls (P < 0.001) than in patients with chronic liver disease. No relation was found between NO2- and viremia or response to interferon therapy in patients with chronic hepatitis B. In contrast in chronic hepatitis C, responder patients had significantly higher NO2- than nonresponders (P < 0.01). With respect to the relation between NO2- levels and liver damage, patients with cirrhosis had lower NO2- levels than the rest of the patients (P < 0.001). In conclusion, patients with chronic viral hepatitis have low serum NO2- levels.

Adult↗
PubMed1997

A pilot study of recombinant interleukin-2 for treatment of chronic hepatitis C.

The optimal and safer interleukin-2 (IL-2) dose for treatment of chronic hepatitis C virus (HCV) infection has been studied in 33 HCV-RNA positive patients with chronic hepatitis C. Patients were randomly allocated to receive 5 days per week during 12 weeks IL-2 doses of: 0.9 MIU (n = 10), 1.8 MIU (n = 10), or 3.6 MIU (n = 13). After 12 weeks, responder patients stopped treatment, whereas nonresponders received 12 additional weeks of IL-2 at the next higher dose: 1.8, 3.6, or 5.4 MIU. As a whole, after the first 12 weeks of IL-2 alanine aminotransferase (ALT) levels significantly decreased (P < .001) with respect to the baseline values (140 +/- 63 vs. 70 +/- 30 IU/L). At the end of treatment (24 weeks), the mean ALT level (80 +/- 50 IU/L) continued significantly lower (P < .001) than the baseline one, and 24% of patients normalized ALT levels; according to dosage, ALT normalization was: 0% for 0.9 MIU, 25% for 1.8 MIU, 5% for 3.6 MIU, and 18% for 5.4 MIU. HCV-RNA levels decreased during treatment, but in none of the patients became undetectable. All patients had a local reaction at the injection site with induration, erythema, and swelling, which was dose-related. The dose of 5.4 MIU was poorly tolerated and was reduced to 3.6 MIU in 4 of 11 patients. No changes in hematological parameters were observed. At the end of follow-up (6 months) four of eight responder patients continued with normal ALT. In conclusion, IL-2 treatment for chronic hepatitis C induced a biochemical response in 8 of 33 (24%) patients at the end of therapy while at the end of follow-up, 4 of 33 (8%) patients remained with normal ALT. The dose of 1.8 MIU is well tolerated and seems to be the most efficacious.

Adult↗
PubMed1997

GB virus C RNA in serum, liver, and peripheral blood mononuclear cells from patients with chronic hepatitis B, C, and D.

BACKGROUND & AIMS: No conclusive data about GB virus C (GBV-C) tropism are available. We have studied the presence of genomic and antigenomic GBV-C RNA in serum, liver, and peripheral blood cells of 56 patients with chronic hepatitis B, C, or D virus infection. METHODS: Genomic and antigenomic GBV-C RNA were detected by reverse-transcription nested polymerase chain reaction. Specificity was confirmed by sequencing, by chemical modification of the RNA, and by using tagged primers. RESULTS: Genomic GBV-C RNA was found in 10 of 56 (18%) of the sera. In contrast, antigenomic strand was not detected. The sequence of the amplified GBV-C RNA from 3 patients showed a 96% homology among them and from 83% to 88% with previously described isolates. Genomic GBV-C RNA was found in 7 of 7 liver samples of the patients with serum GBV-C RNA. In 6 of these 7 patients (85%), antigenomic strand was found. Genomic RNA was found in 7 of 7 of the peripheral blood cell samples of the same 7 patients. Antigenomic GBV-C RNA was not found in these cells. CONCLUSIONS: These results suggest that GBV-C is a hepatotropic virus that replicates in the human liver. The data do not support a role for GBV-C in chronic liver disease.

Adult↗
PubMed1997

Impaired interferon induction of human MxA protein in chronic hepatitis B virus infection.

MxA protein is interferon inducible, and its role as an antiviral mediator is being studied in various viral diseases. Several cytokines, including type 1 interferons (alpha and beta), interleukins 2 and 12, and granulocyte, macrophage, and granulocyte-macrophage colony-stimulating factors, were tested for their ability to induce human MxA protein synthesis in peripheral blood mononuclear cells from 15 chronic hepatitis B virus-infected patients and 6 healthy subjects as controls. Constitutive MxA expression was scarce in patients and controls but increased significantly in response to type I interferons. MxA responsiveness to interferon alpha was diminished significantly in chronic hepatitis B patients, compared with healthy donors (P < 0.05); this effect was more marked in patients with high viremia levels. Interleukins 2 and 12, and none of the colony-stimulating factors tested, induced low, but detectable, MxA protein levels. These results indicate that chronic infection by hepatitis B virus may impair activation of the immune cells and their capacity to respond to type 1 interferons.

Adult↗
PubMed1997

Symptom change and extrapyramidal side effects during acute haloperidol treatment in chronic geriatric schizophrenics.

Haloperidol (HAL) has been widely used in the elderly. Little is known about the phenomenology of schizophrenia in late life or the response to antipsychotic treatment. We prospectively studied 19 elderly patients treated with HAL for 25 days. They ranged in age from 55 to 83 (mean age = 67.5 +/- 6.4 years). After a washout period in 15 patients (4 patients had been noncompliant with medication for at least 1 month), patients were rated before treatment and at the end of the assessment period with the Positive and Negative Syndrome Scale (PANSS) and Simpson-Angus extrapyramidal side effects rating scale (SA). Baseline PANSS scores were associated with change in SA scores (r = .52, p = .02) and with SA baseline score (r = .45, p = .05). Age was negatively associated with baseline positive subscale (r = -.42, p = .07) and endpoint positive subscale scores of PANSS (r = -.48, p = .04). Age was positively associated with improvement in negative symptoms (r = .53, p = .02). Haloperidol dose was negatively associated with improvement in positive symptoms (r = -.46, p = .04). Although studies with larger samples sizes are needed, these findings may indicate that elderly schizophrenics do not respond to treatment in the same manner as do younger schizophrenics.

Aged↗
PubMed1996

Patterns of immune responses to the host-encoded GOR and hepatitis C virus core-derived epitopes with relation to hepatitis C viremia, genotypes, and liver disease severity.

Antibody responses to the GOR epitope and hepatitis C virus (HCV) core were investigated in 136 patients with chronic HCV infection. Patient age (P = .011) and necroinflammatory activity (P < .001) were significantly greater in 92 (67.6%) patients with anti-GOR than in 44 (32.4%) patients without anti-GOR. HCV RNA concentration was significantly higher in patients with anti-GOR (P = .031). HCV 1a or 1b genotypes were also found according to anti-GOR status. GOR and HCV core (amino acids 5-19) antibody responses correlated significantly (rs = .615, P < .001). Anti-HCV core(5-19) was detected in 67 (73%) of 92 patients with and in 14 (32%) of 44 without anti-GOR (P < .001). Patients with concurrent anti-GOR and anti-HCV core(5-19) had significantly greater necroinflammatory activity (P = .003). By multivariate analysis, anti-HCV core(5-19), patient age, and necroinflammatory activity were correlated with anti-GOR response (P < .001). Reactivity to the GOR autoepitope correlates with HCV core response and liver necroinflammatory activity, thus suggesting an immunopathogenic role in chronic hepatitis C.

Adult↗
PubMed1995

Leucovorin and folic acid regimens for selective expansion of murine 5,10-methylenetetrahydrofolate pools.

Mice bearing subcutaneously implanted EMT6 mammary adenocarcinoma were treated with leucovorin or folic acid by continuous subcutaneous infusion or bolus intraperitoneal injection. (6R)-5,10-Methylenetetrahydrofolate pools in cytosolic extracts of the tumor, marrow, and gut were measured by analysis of the ternary complex with thymidylate synthase (5,10-methylenetetrahydrofolate: dUMP C-methyltransferase, EC 2.1.1.45) and 5-fluoro-2'-deoxyuridylate, and the polyglutamate distribution in the (6R)-5,10-methylenetetrahydrofolate pool was analyzed by native gel electrophoresis. Bolus intraperitoneal administration of either leucovorin or folic acid caused dose-dependent expansion of the (6R)-5,10-methylenetetrahydrofolate pool in the tumor, but not in the marrow or gut. For example, the AUC (0-5 hr) in the tumor increased from a baseline value of 8.2 to 20 nmol/mg protein.hr after a bolus dose of 1.5 mmol/kg of leucovorin or folic acid, whereas the increase in marrow and gut was 2- to 4-fold lower. Continuous subcutaneous infusion at the same total dosage over 3 days gave AUC (0-96 hr) values of 134 nmol/mg protein.hr for controls as compared with 347 nmol/mg protein.hr for the leucovorin group and 254 nmol/mg protein.hr for the folic acid group. In contrast to bolus treatment, the increase in (6R)-5,10-methylenetetrahydrofolate in the marrow and small intestine with both leucovorin and folic acid infusion was similar to the increase in the tumor. Thus, intraperitoneal bolus injection was tumor selective, but subcutaneous continuous infusion was not. Longer-chain polyglutamates of (6R)-5,10-methylenetetrahydrofolate in the tumor after bolus treatment with 0.375 and 0.75 mmol/kg of leucovorin or folic acid increased relative to controls. At higher doses of 1.5 and 2.25 mmol/kg, an increase was observed only in the mono/diglutamate fraction. In marrow, on the other hand, the mono/diglutamate fraction, but not the longer-chain polyglutamates, increased at all doses. In the constant infusion regimen, longer-chain polyglutamates increased in all three tissues, though in gut and marrow the mono/diglutamate fraction increased more than in tumor. Leucovorin and folic acid were converted to (6R)-5,10-methylenetetrahydrofolate more efficiently but less selectively during a 3-day subcutaneous infusion than after an intraperitoneal bolus. Longer-chain polyglutamates were selectively increased in tumor by both regimens of leucovorin administration.

Animals↗
PubMed1995

Treatment of chronic hepatitis C with cirrhosis with recombinant human granulocyte colony-stimulating factor plus recombinant interferon-alpha.

Interferon therapy in cirrhotic patients with hepatitis C virus infection is not efficient. In an attempt to improve the response rate, a pilot study using recombinant human granulocyte colony-stimulating factor (rhG-CSF) alone, and in combination with recombinant interferon-alpha (rIFN), was carried out. Fifteen cirrhotic patients with hepatitis C virus infection were randomly allocated into 3 groups to receive treatment: 0.5, 1, or 1.5 micrograms/kg of rhG-CSF daily for 4 weeks, followed by a 4 week resting period, and by the same dose of rhG-CSF daily, plus 6 MU of rIFN 3 times weekly for 4 weeks. They then continued to receive 6 MU of rIFN alone for 4 weeks, followed by 3 MU of rIFN for 16 weeks. After the 4 weeks of treatment with rhG-CSF alone, no changes in alanine aminotransferase (ALT) levels were observed. No changes occurred during the resting period. Three of 10 patients who ended the rhG-CSF plus rIFN treatment period had normal ALT values. During the treatment with rIFN alone, two responders suffered a relapse. The other responder had normal ALT until the first month of follow-up. In summary, the combination of rhG-CSF and rIFN seems promising for the treatment of patients with chronic hepatitis C and liver cirrhosis.

Adult↗
PubMed1995

Sequence of non-structural regions 3 and 5 of hepatitis C virus genomes from Spanish patients: existence of a predominant variant related to type 1b.

Several hepatitis C viruses (HCV) have been described. In this study, the prevalence of HCV subtypes 1a, 1b, 2a and 2b has been studied by means of specific PCR in 93 serum samples of Spanish patients. Among these, the HCV-1b subtype was the most frequently detected (62%). Complementary DNA fragments from non-structural region 3 (NS3) and 5 (NS5), obtained from serum samples of three Spanish patients, were amplified by PCR and the products were cloned and sequenced. Comparison of the sequence obtained with those previously published shows the highest homology (91.7% in NS3 and 91.8% in NS5) with the HCV-1b subtype. The incidence of the local variant was analysed among the HCV-1b-infected patients. In order to distinguish between the local and HCV-1b prototype subtype, a new specific PCR assay was designed using primers from NS5. In the majority of the 76 HCV-1b-infected patients, the local variant was the only subtype detected (53%). These findings support the existence of a local variant, belonging to the HCV-1b subtype.

Amino Acid Sequence↗
PubMed1995

Evaluation of PCR and indirect enzyme-linked immunosorbent assay on milk samples for diagnosis of brucellosis in dairy cattle.

A study was performed to evaluate the previously described PCR (C. Romero, C. Gamazo, M. Pardo, and I. López-Goñi, J. Clin. Microbiol. 33:615-617, 1995) for the diagnosis of brucellosis in dairy cattle. Milk samples from 56 Brucella milk culture-positive cattle and from 37 cattle from Brucella-free herds were examined for Brucella DNA by PCR and for specific antibodies by an indirect enzyme-linked immunosorbent assay (ELISA). The specificities of both tests were 100% when testing the milk samples from Brucella-free cattle. The milk samples from 49 infected cattle were positive by PCR (87.5% sensitivity), and 55 were positive by ELISA (98.2% sensitivity). A PCR-positive sample was negative by ELISA, and 7 ELISA-positive samples were PCR negative, yielding an observed proportion of agreement of 0.91 for the two tests. Although the results suggest that ELISA is a better screening test than PCR, the combined sensitivity of the two assays was 100%, and their simultaneous application could be more useful than one test alone for a rapid screening of brucellosis in dairy cattle.

Animals↗
PubMed1995

Specific detection of Brucella DNA by PCR.

A PCR assay with primers derived from the 16S rRNA sequence of Brucella abortus was developed. Nine different combinations between six primers were tested. One pair of primers, which amplified a 905-bp fragment, was selected. As little as 80 fg of Brucella DNA was detected by this method. DNAs from all of the representative strains of the species and biovars of Brucella and from 23 different Brucella isolates were analyzed and yielded exclusively the 905-bp fragment. No amplification was detected with DNAs from 10 strains phylogenetically related to Brucella spp., 5 gram-negative bacteria showing serological cross-reactions with Brucella spp., and 36 different clinical isolates of non-Brucella species. Only Ochrobactrum anthropi biotype D yielded a PCR product of 905 bp, suggesting a closer relationship between Brucella spp. and O. anthropi biotype D. The specificity and high sensitivity of the PCR assay may provide a valuable tool for the diagnosis of brucellosis.

Base Sequence↗
PubMed1995

Risks and benefits of interferon-alpha in the treatment of hepatitis.

The high worldwide prevalence of chronic viral hepatitis, as well as its progressive course, have led to the performance of multiple clinical studies. The natural history of the disease is different depending on the infecting virus; thus, the evolution to liver cirrhosis and/or hepatocellular carcinoma for the hepatitis B, C and delta (D) viruses in chronic hepatitis is 15, 20 and 75%, respectively. Different therapeutic agents have been used in attempts to modify the natural course of these diseases, interferon-alpha (IFN alpha) having proved to be the most effective. In 30 to 50% of patients, treatment with IFN alpha has achieved inhibition of viral replication, as well as normalisation of aminotransferase levels. Moreover, in a majority of patients, histological improvement is observed, principally in piece-meal necrosis and portal inflammation. The dosage currently recommended for treatment of chronic hepatitis B is 30 to 35MU weekly for a minimum of 4 months; when there is a co-existing delta virus infection, the total dosage employed should be greater. For hepatitis C, the minimum effective dosage is 9MU weekly, and a treatment duration of 12 months is recommended. The administration of IFN alpha produces a series of dose-dependent adverse effects, which are reversible on suspension of the medication. The most frequent of these adverse reactions is the 'flu-like' syndrome, which is self-limited and generally well tolerated. Secondary haematological alterations (leucopenia and thrombocytopenia) are the most frequent cause of reduction in dosage or suspension of treatment, although the latter is not normally necessary. The proportion of patients requiring dosage modification or suspension of treatment fluctuates between 5 and 15%. Taking the evolution of chronic hepatitis into account, there can be no doubt that all patients with this disease should be offered treatment. At present, the drug of choice is IFN alpha, as it slows disease progression and it is generally well tolerated.

Hepatitis↗
PubMed1995

Immunoglobulin M antibody to hepatitis C virus core antigen: correlations with viral replication, histological activity, and liver disease outcome.

Immunoglobulin M (IgM) antibody to hepatitis C core antigen (anti-HCV-core) was tested by enzyme immunoassay against a synthetic peptide representing amino acids 1 to 62 of the core protein. Of 214 patients with different categories of histological activity, 193 (90%) showed positive results for IgM anti-HCV-core, and 207 (97%) had HCV RNA; most cases (186, 87%) had both markers detectable simultaneously. No differences in the frequency of IgM anti-HCV-core were observed with respect to epidemiological, biochemical, or histological parameters. In 175 interferon alfa (IFN-alpha) recipients, and in 39 untreated controls, pretreatment IgM anti-HCV-core frequencies were similar: 28 of 32 (88%) in sustained responders; 55 of 61 (90%) in responders with relapse; 72 of 82 (88%) in nonresponders; and 38 of 39 (97%) in untreated controls. After IFN-alpha therapy, IgM anti-HCV-core levels became undetectable with significantly greater frequency in sustained responders (P = .014); a similar trend was observed for HCV RNA (P < .0001). IgM anti-HCV-core levels decreased after therapy in responders (P < .001) but increased in nonresponders. Fifty-one cases were longitudinally tested in relation to long-term disease outcome. Both markers remained detectable in most nonresponders with persistent liver disease, in most responders before relapse, and in all but one case at the time of biochemical relapse. IgM anti-HCV-core and HCV RNA became undetectable in most sustained responders, but reappeared despite a long-lasting transaminase normalization, behaving as asymptomatic HCV carriers; the possibility that disease reactivation may take place years afterwards cannot be excluded.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗