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Biomedical subjects

A Alberti

Publications and source records attributed to A Alberti.

At least 19 recordsLinked to original sources
PubMed1999

Absolute quantification of brain metabolites by proton magnetic resonance spectroscopy in normal-appearing white matter of multiple sclerosis patients.

The aim of this research was to obtain an absolute quantification of the N-acetyl-aspartate, choline, creatine and phosphocreatine levels in normal-appearing white matter by means of 1H magnetic resonance spectroscopy in a group of multiple sclerosis patients (27 with the relapsing-remitting form and 13 with the secondary progressive form). These values were compared with those of a group of 12 age-matched healthy control subjects. A significant decrease in the N-acetyl-aspartate concentration was found in normal-appearing white matter of frontal and parietal brain areas in multiple sclerosis patients compared with the same areas in control subjects. This reduction was more evident in progressive patients. The decrease in the N-acetyl-aspartate concentration in normal-appearing white matter significantly correlated with the Expanded Disability Status and the lesional load. No significant change was found in the concentration of creatine or choline. This finding concurs with previous evidence of heterogeneity in the multiple sclerosis pathological process which is not confined to the lesions and involves not only myelin, but also axons, even in white matter which appears normal on MRI.

Adult↗
PubMed1998

Hepatitis C virus infection associated with human hepatocellular carcinoma: lack of correlation with p53 abnormalities in Caucasian patients.

BACKGROUND: Several lines of evidence indicate that there is a close association between hepatitis C virus (HCV) infection and hepatocellular carcinoma (HCC). However, the role of the virus itself in the development of the disease is not yet well understood. METHODS: In liver samples from 15 anti-HCV positive Caucasian patients with HCC, the authors searched for the presence and genomic characteristics of the infecting virus, and also analyzed the p53 gene by single strand conformation polymorphism and sequencing of abnormal bands. RESULTS: In all cases but one, HCV RNA was detected in nonneoplastic liver tissue, whereas in neoplastic tissue, viral sequences were detected in 6 of 6 samples containing moderately differentiated HCC (Edmondson grades I-II) and in 2 of 9 containing poorly differentiated HCC (Edmondson grade III) (P=0.007). Seventy-three percent of the cases were infected by genotype 1 and 20% by genotype 2, whereas the liver cells of 1 patient with a previous history of hepatitis B infection were HCV RNA negative. p53 mutations, observed in 2 patients, consisted of a G-to-A transition at codon 176 of exon 5 in 1 patient and a G-to-T transversion at codon 287 of exon 8 in the other. CONCLUSIONS: The results of this study indicate that HCV may contribute to liver tumor development during the early stages of carcinogenesis, whereas p53 gene mutations were detected only in 2 of 15 patients in this cohort.

Adenine↗
PubMed1998

Retrospective analysis of the effect of interferon therapy on the clinical outcome of patients with viral cirrhosis.

BACKGROUND: Recent data suggest that interferon therapy (IFN) can reduce the risk of progression to hepatocellular carcinoma (HCC) in patients with hepatitis C virus (HCV)-related cirrhosis. METHODS: A cohort of 189 patients with Child's Stage A cirrhosis of viral etiology followed prospectively were analyzed retrospectively to assess the effects of IFN on the clinical course and development of HCC. RESULTS: During a mean follow-up of 71.5+/-23.6 months, 7.9% of 88 treated and 21.8% of 101 untreated patients showed worsening of the Child's disease stage (P < 0.01); 5.6% of treated and 26.7% of untreated patients developed HCC (P < 0.001); and 3.4% of treated and 19.8% of untreated patients died of liver disease or underwent orthotopic liver transplantation (OLT) (P < 0.005). Using Cox's regression analysis, no treatment with IFN, high bilirubin and alkaline phosphatase (ALP) levels, and low leukocyte counts and prothrombin activity (PT) were associated significantly with worsening of Child's disease stage; no treatment with IFN, long term disease, low albumin and PT, and high gamma-glutamyl transpeptidase (GGT) were related significantly to HCC development; and no treatment with IFN, low albumin and PT, and high GGT and ALP were associated significantly with reduced survival. After adjustment for independent risk factors identified by multivariate analysis, the estimated cumulative probability of worsening of cirrhosis (P < 0.05), development of HCC (P < 0.001), and death or OLT (P < 0.005) was significantly lower in IFN-treated patients compared with untreated patients. This beneficial effect of therapy was statistically evident only in HCV positive patients. CONCLUSIONS: These results support the hypothesis that IFN improves clinical outcomes and reduces progression to HCC in patients with HCV-related cirrhosis. These conclusions, based on retrospective data, should be confirmed prospective.

Adult↗
PubMed1998

Double-blind, randomized controlled trial of interleukin-2 treatment of chronic hepatitis B.

Pilot studies have demonstrated that recombinant interleukin 2 (rIL-2) has an indirect antiviral activity against hepatitis B virus, but the minimal dose of rIL-2 for induction of this effect was not defined. The aim of the study was to ascertain the most efficient dose of rIL-2 for induction of the loss of detectable serum HBV-DNA or a 50% or greater decrease in its level. Thirty-one patients with chronic hepatitis B, hepatitis B e antigen and serum HBV-DNA positive were enrolled in this double-blind randomized controlled trial. Patients were divided: Group I (n = 8) placebo; Group II (n = 7) treated with 0.9 MU of rIL-2 subcutaneously administered daily for 8 weeks; Group III (n = 8) treated with 1.8 MU of rIL-2 under the same schedule; Group IV (n = 8) which received 3.6 MU of rIL-2 under the same conditions. At the end of treatment 25% of the patients in the placebo group, and 13% and 25% in rIL-2 groups III and IV, respectively, had a decrease in HBV-DNA higher than 50% of the basal value. None of the patients lost serum HBV-DNA. Only three patients (one from group II and two from group IV) normalized the ALT levels. Overall, during treatment, ALT levels decreased in the treated groups. This decrease occurred simultaneously with an increase in serum HBV-DNA concentration. Since the response rate in the treated groups was similar to that of the placebo group, rIL-2 is not useful as monotherapy for the treatment of chronic hepatitis B at the doses and schedules used in this study.

Adolescent↗
PubMed1998

Growth hormone administration normalizes the ovarian responsiveness to follicle-stimulating-hormone in the early stages of the follicular maturation in women with Down syndrome.

To investigate the sensitivity of ovary to follicle-stimulating hormone (FSH) during the early follicular phase of the human menstrual cycle in patients with Down Syndrome (DS) six postmenarchal patients with Down Syndrome and twelve normoovulatory women were studied. Randomly, DS patients were submitted in two consecutive cycles to a treatment with GH (0.1 IU/Kg i.m.) or saline for 3 days. Pure FSH (75 IU) was given i.v. at day 3 and plasma levels of LH, FSH, E2, Testosterone, DHEAS, Androstenedione, GH and IGF-I were assayed in samples collected for a period of 26 h after the injection. Data were compared with those obtained from controls receiving pure FSH or saline. In control patients FSH injection increased E2 stimulated area under curve (AUC). This value was significantly greater than that found in DS patients, who exhibited an E2-stimulated AUC superimposable to saline treated controls. In DS GH plasma concentrations were significantly lower than in control group (p < 0.05). The treatment with GH is able to normalize the ovarian response to FSH in DS patients at levels similar to those found in FSH treated controls. Moreover in GH treated cycles, both GH and IGF-I plasma concentrations were higher at time of FSH injection with respect to those found in the cycles where saline was given. These results indicate that the ovarian sensitivity to FSH in patients with DS is blunted. Lower GH plasma levels found in this group may in part account for this biological feature, since GH treatment is able to restore the ovarian response, probably via an increase of IGF-I plasma concentrations.

Adolescent↗
PubMed1998

Hepatocellular carcinoma: comparison between liver transplantation, resective surgery, ethanol injection, and chemoembolization.

Between January 1989 and June 1997, 533 patients (423 male, 110 female, mean age 61 years, range 22-89 years) with hepatocellular carcinoma (HCC) were observed at our center. We report on 419 patients retrospectively compared for different treatments: liver transplantation (LT; 55 patients), resective surgery (RS; 41 patients), transarterial chemoembolization (TACE; 171 patients) and percutaneous ethanol injection (PEI; 152 patients). The 3- and 5-year actuarial survival rates were, respectively, 72% and 68% for LT, 64 and 44% for RS, 54 and 36% for PEI, and 32 and 22% for TACE. Survival curves were compared for sex, age, tumor characteristics, alphafetoprotein level, Child class, and etiology of cirrhosis. All patient-related characteristics examined (sex, age) are not significantly related to patient survival. Tumor-related variables and associated liver disease variables significantly conditioned survival in relation to different treatments. LT seems to be the treatment of choice for monofocal HCC less then 5 cm in diameter and in selected cases of plurifocal HCC.

Actuarial Analysis↗
PubMed1998

Comparison of serum and liver hepatitis C virus quasispecies in HCV-related hepatocellular carcinoma.

BACKGROUND/AIMS: The hepatitis C virus (HCV) genome consists of quasispecies populations of heterogeneous variants, especially in the hypervariable region. To assess the profiles of viral quasispecies in HCV-related hepatocellular carcinoma, we studied the viral population patterns in serum and liver tissues of 13 HCV-positive patients with hepatocellular carcinoma developed on cirrhotic and non-cirrhotic livers (5 and 8 cases, respectively). METHODS: HCV genome heterogeneity was analyzed by polymerase chain reaction-mediated single-strand conformation polymorphism analysis, which showed multiple DNA bands representing different hypervariable region sequences. RESULTS: The HCV populations were different between tumorous and nontumorous tissues in 3/5 hepatocellular carcinomas with cirrhosis and in 6/8 without cirrhosis. At least one or more than one common band was detected in both compartments in all but one case. No significant differences in the complexity of HCV quasispecies were found in hepatocellular carcinoma with or without underlying cirrhosis. Comparison of the HCV quasispecies profiles in serum and liver tissues showed a different distribution of HCV variants between these two compartments in 6/7 patients. In four cases, both common and compartmentalized sequences were detected, whereas in two cases, both without cirrhosis, the HCV population in serum was completely different from that found in the liver. CONCLUSIONS: These results suggest that the complexity of HCV populations is influenced by the presence of hepatocellular carcinoma rather than by the severity of the underlying chronic liver disease. The different quasispecies patterns found in serum and liver may reflect different biological properties of circulating and intrahepatic HCV particles or the existence of extrahepatic sites of replication.

Aged↗
PubMed1998

Systemic manifestations and liver disease in patients with chronic hepatitis C and type II or III mixed cryoglobulinaemia.

The aim of this study was to evaluate the prevalence of cryoglobulins in patients with chronic hepatitis B and C virus infection and to investigate the association of type II and type III mixed cryoglobulinaemia with systemic manifestations and liver disease stage and outcome in hepatitis C virus (HCV)-positive patients. We analysed the prevalence of cryoglobulinaemia in a cohort of patients with chronic liver disease and compared the systemic manifestations and liver involvement in HCV-positive patients with type II or type III mixed cryoglobulinaemia. The prevalence of serum cryoglobulins was significantly higher in HCV-positive patients than in hepatitis B surface antigen (HBsAg)-positive patients (55.4 vs 20.6%). In HCV-positive patients, stage of liver disease correlated with the prevalence of cryoglobulinaemia. Patients with type II cryoglobulins showed a significantly higher risk of cirrhosis and of extrahepatic manifestations while patients with type III cryoglobulins had a significantly higher prevalence of hepatocellular carcinoma. During follow-up the former had an odds ratio of 11.9 of death from extrahepatic complications while the latter had an odds ratio of 3.4 of dying from hepatic disease. Our study confirms the high frequency of mixed cryoglobulinaemia in patients with chronic hepatitis C virus infection. The presence and type of cryoglobulins seem to be associated with different clinical manifestations and outcome.

Adolescent↗
PubMed1998

Serum and liver HCV RNA levels in patients with chronic hepatitis C: correlation with clinical and histological features.

BACKGROUND: Liver disease in chronic hepatitis C virus (HCV) infection ranges from minimal lesions to liver cirrhosis, eventually evolving to hepatocellular carcinoma. Whether and how HCV determines the different clinical and histological manifestations of the disease is not fully understood. AIMS: To verify whether the amount of virus in individual patients could be related to the severity of liver injury. PATIENTS AND METHODS: Levels of HCV RNA were measured in serum in 96 consecutive patients with chronic hepatitis type C using a signal amplification assay. The relation between viraemic values and the corresponding viral load in the liver was assessed in a subgroup of 21 patients in whom HCV RNA was measured in serum samples and liver specimens obtained at the same time. RESULTS: A positive correlation was observed between the amount of viral nucleic acid in the two compartments, indicating that levels of viraemia reflect the amount of virus present in the liver. Viral load did not correlate with aminotransferase activities nor with histological diagnosis, and serum and liver levels of HCV RNA were not significantly different in patients infected by the various HCV genotypes. CONCLUSIONS: Measurement of HCV replication in serum is a mirror of viral replication in the liver. The extent of replicative activity of HCV does not seem to play a role in the modulation of the associated hepatic disease.

Female↗
PubMed1998

1H-MRS in patients with multiple sclerosis undergoing treatment with interferon beta-1a: results of a preliminary study.

BACKGROUND: In vivo magnetic resonance spectroscopy (MRS) has been widely used to assess biochemical changes which occur in demyelinating lesions in white matter of patients with multiple sclerosis. It has been suggested that metabolic variations evidenced by MRS are sensitive indicators of the effects of immunomodulatory treatments in this disease. Given the recent finding of an increase in the disease activity in patients with multiple sclerosis treated with interferon (IFN) beta-1a in the first period of treatment,1H MRS was used to investigate further the modification in brain metabolic indices, particularly in the first phase of IFN beta treatment. METHODS: A 1H MRS study was performed on five patients with relapsing-remitting multiple sclerosis who were being treated with intramuscular IFN beta-1a (6 million units/week) for six months and on five untreated patients. The mean age, duration of the disease, and expanded disability status scores (EDSS) of the two groups were similar. Patients were evaluated at the beginning of the study and in the first, third, and sixth months of treatment. RESULTS: In the multiple sclerosis white matter lesions, N-acetylaspartate (NAA), choline (Cho), inositol (Ins), and creatine (Cr) peaks did not vary significantly over the entire period of the study in the untreated group. In the treated group there was a significant increase in the Cho peak area at the first month compared with the pretreatment period, and this increase continued in the third and sixth months (p<0.001). A slight but not significant rise in the Cho peak was also found in normal appearing white matter in the patient group undergoing treatment with IFN beta-1a. The increase in Cho and the lack of significant changes in Cr and NAA peaks induced a significant rise in Cho/Cr and Cho/NAA ratios over the entire period of treatment compared with those at the beginning of the study (p<0.02 and p<0.005 respectively). In the treated group there was a slight but significant increase in the Ins peak in the first month (p<0.05) but in the third and sixth months of treatment the Ins values returned to the pretreatment range. CONCLUSIONS: IFN beta-1a has an impact on metabolite concentrations in multiple sclerosis lesions measured by proton MRS. The increase in Cho, Cho/NAA, and Cho/Cr ratios in multiple sclerosis lesions reinforces the view that they are an index of active or recent demyelination and could support the clinical, neuroradiological and immunological evidence showing an increase in disease activity during the first period of treatment with IFN beta-1a. On the other hand, the increase in the Cho peak could be indicative of a rise in membrane turnover in multiple sclerosis lesions or a remodelling of plaques which is not necessarily due to a de novo immune mediated demyelination.

Adult↗
PubMed1998

In chyloptysis, SP-A affects the clearance of serum lipoproteins entering the airways.

Serum lipoproteins may enter the airways and appear in sputum (chyloptysis) when the lymphatic circulation is impaired by inflammation, neoplasia, or an abnormal proliferation of smooth muscle cells. While analyzing the bronchoalveolar lavage fluid of a patient with chyloptysis, we noticed that surfactant could not be separated from contaminating serum lipoproteins and speculated that lipoproteins might interact with surfactant components. To clarify this point we immobilized surfactant protein (SP) A on microtiter wells and incubated it with 125I-labeled very low density lipoproteins (VLDLs), low-density lipoproteins, and high-density lipoproteins. We found that SP-A binds lipoproteins. Studying in greater detail the interaction of SP-A with VLDLs, we found that the binding is time and concentration dependent; is inhibited by unlabeled lipoproteins, phospholipids, and antibodies to SP-A; is increased by Ca2+; and is unaffected by methyl alpha-D-mannopyranoside. Whole surfactant is a potent inhibitor of binding. Furthermore, we found that SP-A increases the degradation of VLDLs by alveolar macrophages and favors the association of VLDLs with alveolar surfactant. We conclude that SP-A influences the disposal of serum lipoproteins entering the airways and speculate that binding to alveolar surfactant might represent an important step in the interaction between exogenous substances and the lung.

Bronchoalveolar Lavage Fluid↗
PubMed1998

Uptake and degradation of Curosurf after tracheal administration to newborn and adult rabbits.

This paper examines the removal from the airways of Curosurf, a commercial surfactant derived from porcine lungs, administered at pharmacological concentrations to newborn or adult animals. Curosurf was labelled by the addition of radioactive dipalmitoyl phosphatidylcholine (DPPC) and administered intratracheally to newborn and adult rabbits at a dose of 200 mg x kg(-1) body weight. The disappearance of DPPC from the airways and its appearance in alveolar macrophages, lung parenchyma, lamellar bodies, serum, liver, kidneys and brain was then studied for 24-48 h. The in vitro degradation of Curosurf DPPC by alveolar macrophages was also studied. During the first 3 h after instillation, large amounts of Curosurf left the airways and became associated with tissue, indicating that it mixed rapidly with the endogenous pools of surfactant. A fraction of administered DPPC became associated with the lamellar bodies, suggesting that Curosurf can be recycled. Curosurf administration did not stop the secretion of endogenous surfactant. Very little intact radioactive DPPC could be recovered at any time in alveolar macrophages, however, macrophages have the ability, in vitro, to degrade Curosurf. Newborn rabbits lose Curosurf from the lungs at a slower rate than adult rabbits. One and two days after instillation, organic extracts from the liver, kidney, brain and serum contained small but measurable amounts of radioactivity. These results indicate that Curosurf rapidly enters the pathways of surfactant metabolism and that alveolar macrophages may play an important role in the catabolism of Curosurf.

1,2-Dipalmitoylphosphatidylcholine↗
PubMed1998

Characteristics of hepatitis C virus before and after interferon treatment in patients with ongoing viraemia but sustained biochemical response.

In hepatitis C virus (HCV) infection, persistent viraemia can occur after successful biochemical response to interferon treatment. To assess whether this unusual profile might be due to trivial amounts of remaining virus or to the emergence of less pathogenic HCV strains, pre- and posttreatment sera from 27 patients who remained with HCV-RNA, despite sustained transaminase normalisation after interferon therapy, were investigated. All but one had infection by genotype 2 (P < 0.0001), and levels of HCV-RNA were not decreased after therapy. Sequence comparison of the 5' untranslated region revealed mixed viral populations and "not compensatory" nucleotide transitions localised at the stem level of the secondary structure of this region in samples taken before and after treatment. Neither quantitative nor qualitative viral changes, at least for the 5' untranslated region, are responsible for interferon-induced biochemical remission in these patients typically infected by genotype 2.

Alanine Transaminase↗
PubMed1998

IGF-I levels in prepubertal and pubertal children with Down syndrome.

BACKGROUND: Growth retardation is a main feature of Down syndrome but it is still unclear whether an alteration of the GH/IGF-I axis is present in this condition. Concerning IGF-I levels, they have been found reduced by some authors but normal by others. METHODS: On these bases, IGF-I levels have been assessed from prepubertal to late pubertal stages of gonadal maturation in a large group of children and adolescents with Down syndrome (DS, 68 M, 45 F, 12.5 +/- 0.6 yr; prepubertal n = 39, pubertal n = 74) with those in a group of normal children and adolescents (NS, 75 M, 87 F; 11.1 +/- 0.4 yr; prepubertal n = 94, pubertal n = 68). RESULTS: Within each group, IGF-I levels were gender-independent while showed age-related variations with positive association with pubertal stage--peaking up in pubertal stage IV--(DS: r = 0.6, NS: r = 0.4, both p < 0.0001) and testosterone (DS: r = 0.6, NS: r = 0.5, p < 0.001) or estradiol (DS: r = 0.6, NS: r = 0.5, p < 0.001) levels. Considering whole groups, mean IGF-I levels in DS were slightly but significantly lower than those in NS (257.9 +/- 12.5 vs 310.8 +/- 12.6 micrograms/l, p < 0.02). Analyzing individual IGF-I levels in DS with respect to normal ranges per pubertal stage, more than 85% of IGF-I levels resulted within the normal limits. These results demonstrate that IGF-I levels in DS patients are generally within the normal range--though a slight reduction of mean IGF-I levels is present--and follow normal age-related variations with clear cut increase at puberty and positive association with gonadal steroid levels. CONCLUSIONS: This evidence points toward the need to clarify the GH/IGF-I axis function and activity in DS patients.

Biomarkers↗
PubMed1997

Prevalence and natural history of hepatitis C infection in patients cured of childhood leukemia.

The aim of this study was to ascertain prevalence and natural history of hepatitis C virus (HCV) infection in a large cohort of patients cured of childhood leukemia who had been followed prospectively for liver disease for at least 10 years since chemotherapy withdrawal: 114 consecutive patients entered the study. Liver function tests and ultrasonography were used to assess presence of liver disease. Patients were tested for antibody to HCV and for serum HCV-RNA at the end of chemotherapy and at the end of follow-up. At chemotherapy withdrawal, 56 patients (49%) were HCV-RNA positive, often without detectable anti-HCV, and in these cases, transaminase levels were more elevated during (P = .08) and after (P = .04) chemotherapy compared with HCV-RNA negative cases. Patients were then followed-up 13 to 27 years (mean, 17) after chemotherapy withdrawal. During this period, 38 initially anti-HCV negative patients seroconverted to anti-HCV and 17 initially anti-HCV positive cases lost reactivity. Forty patients were persistently HCV-RNA positive in serum, while 16 initially viremic patients became HCV-RNA negative during follow-up. At the end of the observation period, a persistent transaminase elevation was detected only in four HCV-RNA positive and anti-HCV positive cases, while no patient developed signs or symptoms of decompensated liver disease. Thus, hepatitis C was a frequent finding in long-term survivors after chemotherapy. It was associated with an atypical serologic profile and did not cause severe liver impairment over a period of 13 to 27 years.

Adolescent↗
PubMed1997

Morbidity and mortality due to liver disease in children undergoing allogeneic bone marrow transplantation: a 10-year prospective study.

We have conducted a long-term prospective study of children undergoing bone marrow transplantation (BMT) to assess morbidity and mortality for liver disease. One hundred eleven consecutive children were enrolled between June 1985 and June 1995 and were followed-up for a median of 5.5 years after BMT. Before transplant 48/111 children (43%) had abnormal alanine aminotransferase (ALT), none were HBsAg+ and 4/111 were anti-HCV+. After BMT 4/111 patients (3. 6%) died of liver failure. No relationship was found between pretransplant hepatitis B (HBV) or C (HCV) infection or elevated transaminases and development of severe liver damage. Eighty-two out of one hundred and eleven patients (74%) had abnormalities of ALT after BMT, transient (n = 54) or persistent (n = 28). None developed clinical signs or symptoms of end stage liver disease or of cirrhosis during follow-up. No significant difference in prevalence of liver disease, was found between children with normal or abnormal ALT at BMT (relative risk [RR] = 1.04). HCV infection could be implicated in the etiology of chronic liver disease in 14/28 patients; 2 other patients were found infected by HBV alone (1 case) or combined with HCV (1 case). In the remaining 12 the etiology of chronic liver disease could not be defined. Posttransplant hepatitis B occurred in 4/111 children (3.6%), including a recipient from a donor who had been previously vaccinated against HBV, while no patient who had been vaccinated developed hepatitis B. The rate of posttransplant seroconversion to anti-HCV was 15%.

Adolescent↗