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Biomedical subjects

A Colantoni

Publications and source records attributed to A Colantoni.

At least 19 recordsLinked to original sources
PubMed2004

Lymphoproliferative disorders in chronic hepatitis C.

Chronic hepatitis C virus (HCV) infection is associated with the development of lymphoproliferative disorders (LPDs). The aim of this investigation was to determine the prevalence and characterization of monoclonal gammopathy and benign and malignant LPDs in individuals with chronic hepatitis C. A total of 233 subjects diagnosed with chronic hepatitis C (male/female ratio: 131/102, median age; 49 years) were studied. Serum and urine were examined for the presence of a monoclonal gammopathy. A bone marrow aspirate and biopsy was obtained in individuals with a monoclonal gammopathy. Thirty-two patients (13.7%, 32 of 233) had a monoclonal gammopathy; 75% of them were benign and were not associated with malignant disorders (24 of 32) while 25% were associated with malignant LPDs or a plasma cell disorder (eight of 32). Two additional subjects without monoclonal gammopathy were diagnosed as having a malignant LPDs. The prevalence of malignant LPDs/plasma cell disorder in individuals with HCV-induced chronic liver disease was 4.3%. No difference was found in terms of disease duration, HCV genotype, viral load, alanine aminotransferase level or histopathologic score between the subjects with or without a monoclonal gammopathy. The presence of mixed cryoglobulinaemia was strongly associated with the presence of an underlying malignant disorder. Hence a monoclonal gammopathy is found in 14% of patients with chronic hepatitis C and is associated with malignant B-cell LPD in more than a quarter of such patients. The prevalence of LPDs in individuals with HCV-induced chronic liver disease is greater than that of the normal healthy population.

Adult↗
PubMed2002

Estrogens receptors and oxidative damage in the liver.

There is considerable evidence that reactive oxygen species (ROS) have a causative role in chronic hepatic injury and cancer development via direct and indirect mechanisms. Estrogens produce free oxygen radicals through redox cycling and affect cell proliferation, also in the liver. We are presently involved in evaluating the possible relationship between estrogens receptor expression, type of receptor, oxidative DNA damage and c-myc in chronic liver disease. The data on DNA adducts, c-myc mRNA and variant estrogen receptor in patients with HCV- or HBV-related chronic liver disease are suggesting that those positive for variant liver estrogen receptor present higher genomic oxidative damage, as reflected in 8-OHdG levels. We are also observing that patients with chronic hepatitis and cirrhosis, when positive for variant estrogen receptor, present higher c-myc m-RNA expression, a factor reportedly associated with increased genomic instability, augmented cytoproliferation and carcinogenesis. Our own and other author's data are shedding new light on estrogen pathophysiology, liver damage and hepatic cancer.

Animals↗
PubMed2002

Cytoskeletal proteins and resident flora.

Recent observations demonstrate that enteropathogenetic and enterohaemorrhagic bacteria, as well as other non enteropathogenetic bacteria (Listeria, Coxiella Burnetii), may subvert the host cell cytoskeleton. Models from enteropathogenic bacteria demonstrate that cytoskeletal proteins are required for bacteria binding to the enterocytes and that they play a role in the immune response of the host to intestinal bacteria. The cytoskeletal protein family Tropomyosins is present in all eukaryotic cells, with multiple isoforms regulated by multiple genes. Of the different Tropomyosin isoforms, TM5 has been shown to be expressed in colonic and jejunal epithelial cells, while TM1 in colonic and jejunal smooth muscle. In vitro studies have shown the presence of serum and mucosal IgG against TM5 in almost two thirds of patients with ulcerative colitis, suggesting: a. a possible autoimmune response to Tropomyosin in these patients; b. the hypothesis that the development of pouchitis may be related to the expression of TM5 in the ileal pouch; c. the use of probiotics in the treatment of pouchitis. Overall, the new expression of cytoskeletal proteins on the cell surface appears to be possibly induced by several mechanisms, including intestinal bacteria and apoptosis. The expression of cytoskeletal proteins on the cell surface may induce tolerance or autoimmune response on target cells. Further investigations are, however needed on the possible role of cytoskeletal proteins in human diseases.

Cytoskeletal Proteins↗
PubMed2002

ALEX (artificial liver for extracorporeal xenoassistance): a new bioreactor containing a porcine autologous biomatrix as hepatocyte support. Preliminary results in an ex vivo experimental model.

Long-term maintenance of viability and expression of differentiated hepatocyte function is crucial for bioartificial liver support. We developed a new bioreactor design (ALEX), associated with a new extracellular autologous hepatocyte biomatrix (Porcine Autologous Biomatrix - PBM) support. To test this new bioreactor, we compared it to a standard BAL (BioArtificial Liver) cartridge in a ex vivo model using human plasma added to bilirubin, ammonium and lidocaine. A pathology study was performed on both bioreactors. The results suggest that ALEX allows a maximal contact between the perfusing plasma and the liver cells and a proper hepatocyte support by a cell-to-matrix attachment. ALEX is a suitable cell support bioreactor, guaranteeing long-term maintenance of the metabolic activity of hepatocytes when compared to a standard BAL cartridge.

Ammonia↗
PubMed2001

Increased effective immunogenicity to high-dose and short-interval hepatitis B virus vaccination in individuals with chronic hepatitis without cirrhosis.

Hepatitis B virus (HBV) vaccination is recommended for individuals with chronic liver disease. However, the response to standard doses of hepatitis B vaccines in such individuals has been poor. The aim of the present study was to assess the response to high-dose short-interval HBV vaccination in individuals with chronic liver disease of different aetiologies. A total two hundred and 24 subjects with chronic liver disease (138 chronic active hepatitis and 86 cirrhosis) and 26 healthy controls were vaccinated using a high-dose (40 microg) short-interval (monthly for 3 consecutive months) HBV vaccination schedule. One hundred and thirty-eight of the 224 subjects with chronic liver disease (62%) seroconverted to anti-HBs antibody positivity (>10 mIU/mL) after the third dose of vaccine as compared with 24 of the 26 controls (92%) (P < 0.01). The response rate was reduced in individuals with cirrhosis (36/86, 42%), particularly in alcohol-induced cirrhosis (2/17, 12%), as compared with individuals with chronic hepatitis (102/138, 74%) (P < 0.001). No significant HBV vaccination-related adverse effects were seen in individuals with or without cirrhosis as well as in the controls. High-dose short-interval HBV vaccination is safe and efficacious in individuals with chronic liver disease. The response to HBV vaccination is reduced in cirrhotics, particularly those with alcoholic cirrhosis. These data suggest that HBV vaccination should be accomplished early in an individual cause of chronic liver disease prior to the development of cirrhosis.

Female↗
PubMed2001

High doses of alpha-interferon are required in chronic hepatitis due to coinfection with hepatitis B virus and hepatitis C virus: long term results of a prospective randomized trial.

OBJECTIVE: Coinfection with hepatitis B (HBV) and hepatitis C (HCV) viruses is associated with a more severe liver disease, increased frequency in the development of hepatocellular carcinoma, and resistance to interferon (IFN) therapy when performed with the standard dosages used in single infections. In the attempt to verify whether the outcome of IFN therapy in patients with hepatitis B and hepatitis C coinfection can be improved, we have planned a prospective, randomized trial with medium to high dosages of interferon three times a week for 6 months. METHODS: Thirty patients with HBV-HCV coinfection, and chronic hepatitis were randomized to receive either 6 or 9 MU alpha-interferon three times a week for 6 months. Patients were HBsAg positive, anti-HBe positive, HBV DNA negative by dot blot (6/30 positive by polymerase chain reaction), and anti-HCV-positive, HCV RNA positive. Pretreatment and posttreatment liver biopsies were performed. RESULTS: Five patients treated with 9 MU IFN consistently cleared HCV RNA and HBV DNA, whereas none of those treated with 6 MU reacted in a similar fashion (p = 0.045). Responders showed significant improvement of histological activity index in comparison with nonresponders (mean Ishak score pretreatment versus posttreatment p = 0.002). Long term follow-up showed that none of the patients treated with high doses developed cirrhosis whereas 4/14 treated with low doses did develop cirrhosis. CONCLUSION: Even though the percentage was not very high, the sustained response, the striking histological improvement, and the lack of development of cirrhosis achieved in these patients, indicate that with HBV-HCV coinfection, a trial with high doses of interferon is strongly recommended.

Adult↗
PubMed2001

Peripubertal paternal EtOH exposure.

Fetal alcohol syndrome usually implies effects on the offspring of maternal EtOH consumption during gestation, with fewer reports addressing the impact of paternal exposure on the progeny. One previous report has dealt with the impact of EtOH exposure on peripubertal male rats as a model of teenage drinking and the deleterious effects on the offspring. We report here findings examining the effect of 2 mo of EtOH feeding on male animals as they progressed through puberty on their ability to impregnate EtOH-naive female rats and characteristics of the subsequent litters. The EtOH-imbibing fathers weighed significantly less than pairfed controls and animals ingesting a non-EtOH liquid diet ad libitum. Nevertheless, they were able to mate successfully, although fecundity was significantly reduced. The number of successful pregnancies, defined as carried to term, was diminished from 92% in controls to 75% in EtOH-fed animals (p < 0.05). There was increased paternal testicular oxidative injury demonstrated by enhanced lipid peroxidation, protein oxidation, and decreased ratio of reduced to oxidized glutathione. The litter size of the EtOH-exposed males was reduced by 46%. The average litter size was 12.4+/-1.5 pups/litter in ad libitum animals, virtually identical to the 12.5+/-0.6 pups/litter in the pair fed controls. This is in sharp contrast to the 6.7+/-0.1 pups/litter from the paternal EtOH matings (p < 0.001). There was an increase in the average individual weight of pup offspring of paternally EtOH-exposed animals (p < 0.01 vs pair-fed controls and p < 0.05 vs ad libitum). Curiously, the male-to-female pup ratio was altered with a higher preponderance of male offspring from EtOH-fed fathers. There were no gross malformations noted among the pups. Insulin-like growth factor-1 levels in the pups at 10 d of age were unaltered between the groups. However, leptin was significantly elevated in the EtOH offspring. It appears that chronic EtOH exposure in the peripubertal fathers subsequently decreases fecundity and that this may be mediated by testicular oxidative injury, perhaps leading to accelerated germ cell apoptosis.

Animals↗
PubMed2000

Ethanol exacerbates T cell dysfunction after thermal injury.

To understand the mechanism of suppressed immunity following alcohol consumption and thermal injury, we analyzed T cell functions in a mouse model of acute alcohol exposure and burn injury. Mice with blood alcohol levels at approximately 100 mg/dl were given a 15% scald or sham injury. Mice were sacrificed 48 h after injury. Our data demonstrated a 20-25% decrease in Con A-mediated splenic T cell proliferation (p<0.01) and 45-50% decrease in interleukin-2 (IL-2) production (p<0.01) following burn injury compared to the T cells from sham animals. A further decrease in the proliferation (25-30%) and IL-2 production (40-45%) was detected in T cells derived from burned animals receiving alcohol as compared to burn alone. No significant change in the proliferation and IL-2 production was observed in splenic T cells derived from sham-injured mice regardless of alcohol exposure. Additionally, there was no demonstrable difference in splenocyte apoptosis in any treatment group. These results suggest that alcohol consumption prior to burn injury causes a greater decrease in T cell proliferation and IL-2 production compared to either burn or alcohol injury alone that may further attenuate the cell-mediated immunity and thus enhance susceptibility to infection.

Alcohol Drinking↗
PubMed2000

Cellular immunity after ethanol exposure and burn injury: dose and time dependence.

Acute ethanol exposure prior to burn injury increases the immune dysfunction seen with burn alone, which has been partially attributed to increased circulating and splenic macrophage production of interleukin-6 (IL-6). The current studies examined the effect dose and timing of ethanol exposure prior to burn on cellular immunity. Mice with high (300 mg/dl) circulating levels of ethanol at the time of burn demonstrated further suppression of the delayed type hypersensitivity (DTH) and splenocyte proliferative responses in comparison to mice with moderate (100 mg/dl) ethanol levels. Interestingly, the increase in macrophage IL-6 secretion seen at the moderate dose was not augmented at the high dose; however, the circulating IL-6 levels did reveal a further increase at the high ethanol dose. There were no alterations in splenocyte subset populations and/or apoptosis at the moderate vs. the high ethanol dose. Moderate ethanol exposure 24 h, in comparison to 30 min, before injury resulted in similar decreases in the DTH. These results suggest that the dose-dependent effects of ethanol on immunity following burn injury are not the result of splenic macrophage IL-6 production as shown at the moderate dose and that the immune suppressive effects of ethanol in this model persist after it is cleared from the circulation.

Animals↗
PubMed2000

A double-blind, placebo-controlled study to assess tolerability, pharmacokinetics and preliminary pharmacodynamics of single escalating doses of Z13752A, a novel dual inhibitor of the metalloproteases ACE and NEP, in healthy volunteers.

AIMS: The objective of this study was to evaluate the tolerability of a novel dual ACE-NEP inhibitor, Z13752A, after the oral administration of rising single doses in healthy volunteers. This study was also a preliminarily investigation of Z13752A pharmacodynamics (PD) and pharmacokinetics (PK). METHODS: In this randomized, placebo-controlled, sequential study, two alternating panels of eight healthy male volunteers each (six subjects receiving the active treatment + two subjects receiving placebo) were treated with increasing oral doses of Z13752A: 10, 50, 200, and 600 mg were given to panel I and 20, 100, 400 and 800 mg were given to panel II. The study was double-blind relative to placebo or active treatment, and was open with respect to the dose levels. The same volunteer received placebo only once. RESULTS: Single oral doses of Z13752A, as high as 800 mg, were well tolerated. Only six mild-to-moderate adverse events mainly headache, were reported and appeared to be of little clinical relevance. After administration of 200, 400, 600 and 800 mg of Z13752A, a nonsignificant fall in diastolic blood pressure was detected, in both the standing and supine position. After single oral doses of Z13752A, ACE inhibition appeared to be significant at all the doses tested, linearly correlated with the dose and was almost complete at doses > or = 100-200 mg. NEP inhibition was indicated by elevation of ANP and cGMP plasma concentrations in almost all subjects. In the 200-800 mg dose range, Z13752A produced a 50-100% increase of plasma cGMP levels and a 50-80% elevation in urinary cGMP concentrations. Detectable plasma levels of Z13752A were found in all the treated subjects. Z13752A was well and rapidly absorbed, with peak concentrations reached approximately 2.5 h after administration. The mean apparent elimination half-life from plasma was approximately 12 h. The pharmacokinetics of Z13752A after single oral doses were characterized by low intersubject variability and appeared to be dose-independent. CONCLUSIONS: Z13752A showed a good single dose tolerability profile at doses up to 800 mg. The pharmacokinetic data indicate that Z13752A administered orally is rapidly absorbed and available to the systemic circulation in humans. The relatively slow clearance indicates that a once-a-day dose regimen could be considered for Z13752A.

Adult↗
PubMed2000

The impact of previous HBV infection on the course of chronic hepatitis C.

OBJECTIVE: Individuals with chronic hepatitis C who are anti-HBc positive may carry an occult hepatitis B virus (HBV) infection that can affect their response to antiviral therapy. METHODS: In this study the prevalence of anti-HBc and HBV-DNA positivity was assessed in the serum and liver of 285 HCV-RNA-positive subjects treated with interferon-alpha at 5 mU/day for 12 months. The response to interferon (normal ALT and undetectable serum HCV-RNA) was evaluated at three different endpoints: 1) after 6 months; 2) at the end of treatment; and 3) 6 months after interferon discontinuation. RESULTS: Ninety individuals were anti-HBc positive (32%), 2 of these were HBV-DNA positive in serum and 7 in liver (8%). None of the anti-HBc-negative individuals was HBV-DNA positive in serum or liver. The prevalence of cirrhosis was greater in the anti-HBc-positive group than in the anti-HBc-negative group (p < 0.05), whereas HCV-RNA levels were lower. Anti-HBc-positive individuals had a lower response rate to interferon at 6 months and at the end of treatment as compared to anti-HBc-negative subjects (respectively 42% vs 66%, p < 0.01; and 32% vs 57%, p < 0.01). No difference between the two groups in terms of sustained response was detected 6 months after interferon discontinuation. CONCLUSIONS: The prevalence of anti-HBc is high among HCV-positive individuals. HCV-positive individuals who are anti-HBc positive have: 1) a higher prevalence of cirrhosis; 2) lower HCV-RNA levels; and 3) an impaired ability to respond to interferon treatment.

Adult↗
PubMed2000

Cirrhosis in Turner's syndrome: case report and literature review.

A case of cryptogenic cirrhosis in a patient with Turner's syndrome is presented. The individual was admitted for upper gastrointestinal bleeding due to oesophageal varices. After failure of medical treatment, a transjugular intra-hepatic portal systemic shunt was used to control the bleeding. A liver biopsy revealed cirrhosis with minimal necro-inflammatory activity and no steatosis. Immunohistochemical staining for HCV, HBsAg and HBcAg was negative. No other risk factor for liver disease was recognized and none of the known causes of chronic liver disease was identified after a thorough evaluation for such. Turner's syndrome is a genetic disorder due to X chromosome monosomy in which a wide range of congenital anomalies can occur. Cardiac, renal and skeletal anomalies are all well recognized. The possible association of Turner's syndrome with cirrhosis is herein discussed along with a review of the published literature.

Adult↗
PubMed2000

Dose-dependent effect of ethanol on hepatic oxidative stress and interleukin-6 production after burn injury in the mouse.

BACKGROUND: Burned patients with detectable blood alcohol levels (BAL) show an elevated mortality rate. Interleukin (IL)-6 and reactive oxygen species (ROS) production is stimulated independently by alcohol and burn injury. The aim of the study was to determine whether increasing levels of alcohol differentially enhance the hepatic production of IL-6 and ROS after burn in a murine model of dorsal scald injury. Groups of mice received either saline or alcohol intraperitoneally to reach a BAL of 100 mg/dl or 300 mg/dl at the time of burn (15% total body surface scald) or sham injury. RESULTS: Burn injury alone resulted in a low mortality rate at 24 hr after injury as did the burn group with a BAL of 100 mg/dl (15%), whereas 57% of the mice burned with a BAL of 300 mg/dl did not survive (p = 0.02). Twenty-four hours after burn or sham injury, IL-6 levels were measured by enzyme-linked immunosorbent assay in serum and liver. In the saline-treated group, IL-6 circulating and hepatic levels rose after burn injury (p < 0.03). Circulating IL-6 levels in sham mice increased 1.5-fold in the group with a BAL of 100 mg/dl and 3-fold in those with a BAL of 300 mg/ml (p = 0.005 versus burn-injured, saline-treated). IL-6 hepatic production after burn injury was higher in the mice with a BAL of 300 mg/dl than in those with a BAL of 100 mg/dl and the saline-treated group (p = 0.001). Among the burned mice, alcohol exposure increased hepatic ROS production, measured by lipid peroxidation and protein oxidation, in a dose-dependent manner. CONCLUSIONS: Alcohol enhances in a dose-dependent manner the hepatic production of IL-6 induced by burn injury through the modulation of oxidative stress. The increased mortality rate of mice exposed to alcohol and burn injury may be due to the adverse effect on immune function induced by IL-6 elevation.

Animals↗
PubMed2000

Influence of sex hormonal status on alcohol-induced oxidative injury in male and female rat liver.

BACKGROUND: Oxidative stress contributes to the development of liver injury after chronic alcohol intake. Women exhibit greater sensitivity to alcohol-induced liver disease than do men. The aim of the study was to determine the relationship between the sex hormone status of male and female rats and the degree of alcohol-induced oxidative stress in the liver. METHODS: Male and female rats were pair-fed a liquid diet that contained 36% of their total daily calories as ethanol (EtOH group) or maltose (control group). Blood and liver samples were collected at the end of 8 weeks of diet. RESULTS: Male EtOH rats experienced a reduction in plasma testosterone (T) and an increase in estradiol (E2) levels, with an increase in their calculated E2/T ratio with respect to their controls. Malonaldehyde (MDA) levels, an index of lipid peroxidation, and protein carbonyl content, an index of protein oxidation, in the liver were greater among the EtOH groups in females than in males. In males, an inverse correlation was found between hepatic MDA and circulating T levels, and a direct correlation was disclosed between MDA and estradiol levels. In addition, the hepatic histopathological score correlated inversely with the plasma T levels and directly with the calculated E2/T ratio, an index of feminization. CONCLUSIONS: Alcohol-induced oxidative injury, which contributes to hepatic injury in both male and female rats, is enhanced in females compared with males. A role for plasma T levels in protecting male rat liver from ethanol-induced oxidative injury can be hypothesized.

Animals↗