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Biomedical subjects

Piero Portincasa

Publications and source records attributed to Piero Portincasa.

At least 19 recordsLinked to original sources
PubMed2006

Adefovir dipivoxyl for the treatment of delta-related liver cirrhosis.

OBJECTIVE: To report a case suggesting the beneficial effect of adefovir dipivoxyl in patients with delta-related decompensated liver cirrhosis ineffectively treated with lamivudine. CASE SUMMARY: A 55-year-old woman with chronic hepatitis B virus (HBV), antihepatitis Be positive, and hepatitis delta virus (HDV)-related decompensated liver cirrhosis (Child-Pugh score B9) was awaiting liver transplantation. During this time, she was treated with lamivudine 100 mg/day; however, the drug was stopped after 8 months because it did not produce viral clearance or return serum aminotransferase levels to within normal limits. The patient was not a candidate for interferon alfa therapy but was prescribed adefovir dipivoxyl 10 mg/day. Five months later, serum aminotransferase levels had normalized and, after 7 months of treatment with adefovir, the patient became negative for serum HBV-DNA and immunoglobulin M (IgM) antidelta. At the time of writing (20 mo of therapy), the HBV-DNA and IgM antidelta remained negative, whereas hepatitis B surface antigen and circulating HDV-RNA were positive. No adverse effects associated with adefovir were reported, and the Child-Pugh score (A6) had improved. DISCUSSION: This is the first reported case of some beneficial biochemical and serologic effects of adefovir dipivoxyl in the treatment of delta cirrhosis. The virologic pattern of the patient after adefovir is indicative of poor liver disease activity and prospectively enhances liver transplantation outcome, indicating that adefovir might also be useful in the phase prior to liver transplantation. CONCLUSIONS: Although we have no plausible explanation for our patient's favorable response to adefovir treatment, this case contributes to the knowledge regarding treatment of this very difficult condition as well as adefovir efficacy. Given the positive outcome, this report suggests that adefovir might be beneficial in patients with delta-related liver cirrhosis not responsive to previous lamivudine therapy. Based on the high tolerability of this therapy, this case encourages clinical trials.

Adenine↗
PubMed2006

Cholesterol gallstone disease.

With a prevalence of 10-15% in adults in Europe and the USA, gallstones are the most common digestive disease needing admission to hospital in the West. The interplay between interprandial and postprandial physiological responses to endogenous and dietary lipids underscores the importance of coordinated hepatobiliary and gastrointestinal functions to prevent crystallisation and precipitation of excess biliary cholesterol. Indeed, identifying the metabolic and transcriptional pathways that drive the regulation of biliary lipid secretion has been a major achievement in the field. We highlight scientific advances in protein and gene regulation of cholesterol absorption, synthesis, and catabolism, and biliary lipid secretion with respect to the pathogenesis of cholesterol gallstone disease. We discuss the physical-chemical mechanisms of gallstone formation in bile and the active role of the gallbladder and the intestine. We also discuss gaps in our knowledge of the pathogenesis of gallstone formation and the potential for gene targeting in therapy.

Adult↗
PubMed2006

Defective in vitro contractility of ureteropelvic junction in children with functional and obstructive urine flow impairment.

BACKGROUND/PURPOSE: Studies of children with urinary flow impairment (UFI) at the ureteropelvic junction (UPJ) have revealed prestenotic, stenotic, and poststenotic histologic changes. Muscle function, however, has not been investigated. We therefore evaluated in vitro UPJ contractility by tensiometry in children with UFI. METHODS: Freshly excised UPJs from 11 children with UFI (6 functional, 5 obstructive) were each divided into 3 parallel, prestenotic, stenotic, and poststenotic rings, and those from 7 children with Wilms' tumor were divided into proximal, medial, and distal segments. Each ring was studied in vitro by tensiometry in the basal state and after stimulation with 25 and 60 mmol/L KCl. RESULTS: The stenotic rings from the UFI subjects displayed a significantly lower basal contractility than the other 2 rings, and their 25 and 60 mmol/L KCl-induced contractility was absent or severely reduced, whereas the values of these parameters were similar to that observed in controls in the other 2 rings of patients with either functional or obstructive UFI. CONCLUSIONS: Basal and KCl-induced contractility of the stenotic segment is severely impaired in children and infants with either functional or obstructive UFI, whereas the contractility of their pre- and poststenotic UPJ segments is similar to that recorded in controls.

Adolescent↗
PubMed2006

Liver breath tests non-invasively predict higher stages of non-alcoholic steatohepatitis.

Effectively assessing subtle hepatic metabolic functions by novel non-invasive tests might be of clinical utility in scoring NAFLD (non-alcoholic fatty liver disease) and in identifying altered metabolic pathways. The present study was conducted on 39 (20 lean and 19 obese) hypertransaminasemic patients with histologically proven NAFLD {ranging from simple steatosis to severe steatohepatitis [NASH (non-alcoholic steatohepatitis)] and fibrosis} and 28 (20 lean and eight overweight) healthy controls, who underwent stable isotope breath testing ([(13)C]methacetin and [(13)C]ketoisocaproate) for microsomal and mitochondrial liver function in relation to histology, serum hyaluronate, as a marker of liver fibrosis, and body size. Compared with healthy subjects and patients with simple steatosis, NASH patients had enhanced methacetin demethylation (P=0.001), but decreased (P=0.001) and delayed (P=0.006) ketoisocaproate decarboxylation, which was inversely related (P=0.001) to the degree of histological fibrosis (r=-0.701), serum hyaluronate (r=-0.644) and body size (r=-0.485). Ketoisocaproate decarboxylation was impaired further in obese patients with NASH, but not in patients with simple steatosis and in overweight controls. NASH and insulin resistance were independently associated with an abnormal ketoisocaproate breath test (P=0.001). The cut-off value of 9.6% cumulative expired (13)CO(2) for ketoisocaproate at 60 min was associated with the highest prediction (positive predictive value, 0.90; negative predictive value, 0.73) for NASH, yielding an overall sensitivity of 68% and specificity of 94%. In conclusion, both microsomal and mitochondrial functions are disturbed in NASH. Therefore stable isotope breath tests may usefully contribute to a better and non-invasive characterization of patients with NAFLD.

Acetamides↗
PubMed2006

Is it possible to predict the clinical course of gallstone disease? Usefulness of gallbladder motility evaluation in a clinical setting.

OBJECTIVE: A knowledge of the predictive factors of the development and persistence of symptoms in gallstone patients (GS) plays a key role in clinical decision making. The aim of this study was to evaluate the presence of predictive factors for biliary pain development in GS, stressing the role of gallbladder motility. METHODS: A total of 153 (104 women, 49 men) consecutive GS were enrolled. Gallbladder motility (%Emptying [%E], residual volume [RV]) was evaluated by ultrasonography and biliary symptoms were evaluated using a specific questionnaire in all GS at baseline and after 4 yr of follow-up. RESULTS: At enrolment, 61 GS reported recent (GSr) and 31 GS remote (GSo) (>2 yr before) episodes of biliary pain, and 61 were asymptomatic (GSa). At baseline, GSr showed a greater %E and a smaller RV than both GSo and GSa (p < 0.001). After follow-up, biliary pain developed more frequently in GSr (33.3%) than in GSo (16%) and GSa (15%) (p= 0.04). The search for predictive factors of biliary pain development (by univariate and multivariate analyses) revealed a high %E, a small RV, and a history of biliary pain as risk factors. CONCLUSIONS: Efficient gallbladder motility is present in symptomatic GS and it represents a risk factor for biliary pain development while sluggish motility seems to play a protective role. Thus, gallbladder motility evaluation is a useful diagnostic tool in clinical decision making for GS; in symptomatic GS, a progressive reduction of gallbladder motility could suggest a "wait and see" management policy instead of an immediate surgical approach.

Female↗
PubMed2006

Current pharmacological treatment of nonalcoholic fatty liver.

Nonalcoholic fatty liver disease (NAFLD) is a frequent and potentially progressive chronic liver disease that occurs in subjects who do not abuse alcohol. NAFLD is often associated with obesity, metabolic syndrome and insulin resistance and its more aggressive form, nonalcoholic steatohepatitis (NASH) is a major cause of cryptogenic cirrhosis. NAFLD/NASH are commonly detected because of elevated serum aminotransferase levels, ultrasonographic fatty liver and, at liver histology, steatosis, inflammation, and occasionally fibrosis that may progress to cirrhosis. No established treatment exists for this potentially serious disorder. Current management of NAFLD/NASH is largely conservative and includes diet regimen, aerobic exercise, and interventions towards the associated metabolic abnormalities. The main concern is therefore to decrease liver steatosis and its progression toward steatohepatitis and fibrosis, and the risk of "cryptogenic" cirrhosis. Among the most promising medications, weight reducing drugs, insulin sensitizers and lipid-lowering agents, antioxidants, bile salts, co-factors increasing the mitochondrial transport of fatty acids are being considered. Among them, thiazolidinediones are the most promising drug family that act by activating PPARgamma nuclear receptors and by regulating both microsomal and peroxisomal lipid oxidative pathways. Pharmacological treatment of obesity and probiotics should be considered as potential therapeutic options. In this review, after summarizing the general background on fatty liver, the most current and attractive pharmacological approaches to the problem of NAFLD/NASH are discussed.

Anti-Obesity Agents↗
PubMed2005

Ultrasonographic study of postcibal gastro-esophageal reflux and gastric emptying in infants with recurrent respiratory disease.

AIM: To check the utility of postcibal ultrasonography for the evaluation of reflux in relation to gastric emptying in infants with recurrent respiratory symptoms and to link imaging with clinical data. METHODS: Esophageal reflux (hyperechoic retrograde filling) and gastric emptying (antral areas) were quantified before and after ingestion of a standard formula in 35 untreated infants (13 with chronic cough, 22 with recurrent bronchitis) and in 31 controls. RESULTS: The prevalence of abnormal (> or =8 episodes) postcibal refluxes was 74% in patients and 3% in controls. Number, duration of the longest episode and extent of refluxes were significantly higher in patients compared to controls. Number of refluxes was higher in patients with symptomatic refluxes than in those without. Infants with recurrent bronchitis had more refluxes than those with chronic cough and controls. Extent and timing of gastric emptying were similar in patients and controls. CONCLUSION: Esophageal ultrasonography is a useful and physiological test in infants with recurrent respiratory diseases, which have a high prevalence of abnormal postcibal esophageal reflux and a gastric emptying similar to that of normal controls. Esophageal reflux is more severe in subjects with recurrent bronchitis than in those with chronic cough.

Bronchitis↗
PubMed2005

Gallbladder histopathology during murine gallstone formation: relation to motility and concentrating function.

C57L mice are susceptible and AKR mice are resistant to gallstone formation. We studied in male mice of both strains gallbladder histopathology, cholecystokinin-induced emptying, and concentrating function at 0, 14, 28, and 56 days on a lithogenic diet. Gallbladder wall thickness increased on the diet, with stromal granulocyte infiltration, progressive fibrosis, edema, and epithelial cell indentation, particularly in C57L. Strong basal cholecystokinin octapeptide-induced gallbladder emptying (70% of fasting volumes) occurred in both strains, but fasting gallbladder volumes were significantly larger in C57L (14.8 +/- 2.2 microl vs. 8.8 +/- 1.0 microl). On the diet, fasting volumes increased exclusively in C57L (28.6 +/- 2.9 microl on day 56), with progressively decreased emptying (27% of fasting volumes on day 56). Gallbladder emptying remained normal in AKR. Gallbladder concentrating function decreased on the lithogenic diet (especially in C57L), coinciding with decreased aquaporin-1 (AQP1) and AQP8 expression at the mRNA and protein levels. In additional experiments, similar downregulation of AQP1 and AQP8 mRNA expression occurred in farnesoid X receptor (FXR)-deficient mice after 1 week on the lithogenic diet, without any difference from corresponding wild-type mice. In conclusion, during murine lithogenesis, altered gallbladder histology is associated with impaired motility, reduced concentrating function, and decreased AQP1 and AQP8 expression, the latter without the involvement of the FXR.

Animals↗
PubMed2005

Esomeprazole-induced central fever with severe myalgia.

OBJECTIVE: To report a case of central fever associated with severe myalgia following esomeprazole. CASE SUMMARY: A 64-year-old man presented with intense cephalalgia; severe, diffuse myalgia; and fever (>40 degrees C) after esomeprazole initiation for treatment of gastritis. Five hours after ingestion of the first esomeprazole pill (40 mg), the patient developed fever associated with cephalalgia and myalgia. This condition lasted about 40 hours and disappeared spontaneously. Symptoms partially responded to acetaminophen. Four days later, the patient received a second dose of esomeprazole 40 mg. Subsequently, 4 hours later, fever (>40 degrees C), headache, and difficulty in the movement of all parts of the body recurred. Neurologic examination was negative except for a minor state of disorientation. All reflexes were normal or slightly decreased. No skin lesions or breathing difficulty was noted. Routine blood tests were normal. Again, symptoms resolved spontaneously about 40 hours later. DISCUSSION: The temporal connection between esomeprazole intake and the onset of fever suggests a probable causal link, as confirmed by the Naranjo probability scale. However, the pathogenic mechanism remains unclear. Considering that esomeprazole is able to cross the blood-brain barrier, its peak serum concentration is reached 90-180 minutes after oral administration, and its serum half-life is approximately 2 hours, we assume that the appearance of fever with accompanying neurologic and muscular symptoms might result from the drug interference with the hypothalamic regulatory center of body temperature. CONCLUSIONS: Hyperpyrexia of central origin associated with intense cephalalgia and myalgia may occur as an adverse effect of esomeprazole therapy.

Esomeprazole↗
PubMed2005

Primary sclerosing cholangitis: updates in diagnosis and therapy.

Primary sclerosing cholangitis (PSC) is a chronic cholestatic syndrome of unknown origin mostly found in males, and characterized by diffuse inflammation and fibrosis of both intra- and extra-hepatic bile ducts. So far, PSC is considered as an autoimmune hepatobiliary disease. In most cases the progression of PSC towards liver cirrhosis and liver failure is slow but irreversible, and liver transplantation is currently the only definitive treatment. In recent years, PSC has been an area of active research worldwide with great interest in etiology, pathogenesis, diagnosis, and therapeutic options such as hydrophilic ursodeoxycholic acid and immunosuppressive agent tacrolimus. Recent updates on clinical and therapeutic aspects of PSC are discussed in the present review.

Cholagogues and Choleretics↗
PubMed2005

Nonalcoholic steatohepatitis: recent advances from experimental models to clinical management.

A condition defined as nonalcoholic fatty liver disease (NAFLD) is frequently found in humans. Deemed as a benign condition until recently, more emphasis is now put on the potential harmful evolution of the inflammatory form, that is, nonalcoholic steatohepatitis (NASH), toward end-stage liver disease. This review highlights the major morphologic and pathophysiological features of NASH. The link between experimental biochemical findings in animal models and clinical and therapeutic approaches in humans is discussed. Once all the other causes of persistent elevation of serum transaminase levels have been excluded, the diagnosis of NASH can be only confirmed by liver histology. Other noninvasive diagnostic tools, however, are being investigated to assess specific subcellular functions and to allow the follow-up of patients at higher risk for major liver dysfunction. A better understanding of various pathogenic aspects of NASH will help in identifying potential therapeutic approaches in these patients.

Animals↗
PubMed2005

Glutathione peroxidase, thioredoxin, and membrane protein changes in erythrocytes predict ribavirin-induced anemia.

OBJECTIVE: Low erythrocyte membrane protein sulfhydril concentrations are a risk factor for ribavirin-induced anemia. We further studied the role of oxidative stress and erythrocyte membrane alterations in ribavirin-induced anemia. METHODS: The levels of thioredoxin, glutathione peroxidase, protein sulfhydrils, and protein-mixed disulfides, as well as the electrophoretic membrane protein pattern, were determined in freshly isolated erythrocytes from healthy control subjects, patients without severe anemia during previous ribavirin treatment (still hepatitis C virus [HCV]-positive), and patients who had had severe anemia with ribavirin (still HCV-positive or HCV-negative), 6 months after full recovery. Erythrocytes were also incubated with buffer, ribavirin, phenylhydrazine, or dehydroepiandrosterone, and concentrations of protein sulfhydrils, protein-mixed disulfides, thiobarbituric acid-reactive substances, and total and oxidized glutathione, as well as osmotic resistance, were determined. RESULTS: Patients with previous severe ribavirin-induced anemia had lower levels of protein sulfhydrils (30.9 nmol/mg protein versus 43.2 nmol/mg protein, P<.001) and thioredoxin (0.6 nmol/g hemoglobin versus 1.2 nmol/g hemoglobin, P<.001), higher levels of protein-mixed disulfides (1.5 nmol/g hemoglobin versus 0.5 nmol/g hemoglobin, P<.001) and glutathione peroxidase (618 mU/mg protein versus 393 mU/mg protein, P<.001), and a membrane protein pattern consistent with band 4 dimer disaggregation. These differences were independent of HCV seropositivity. There were negative correlations between levels of glutathione peroxidase and thioredoxin (r=-0.87) and between levels of protein sulfhydrils and protein-mixed disulfides (r=-0.93). In vitro studies showed that erythrocytes of patients who had had hemolysis during treatment of HCV are more susceptible to oxidative stress. CONCLUSIONS: Pronounced differences in markers of oxidative stress and membrane proteins exist between patients with and without a history of ribavirin-induced anemia. Our findings suggest that there are erythrocyte-related risk factors for ribavirin-induced severe anemia.

Adult↗
PubMed2005

Expression and subcellular localization of the AQP8 and AQP1 water channels in the mouse gall-bladder epithelium.

BACKGROUND INFORMATION: Transepithelial transport of water is one of the most distinctive functions by which the gall-bladder rearranges its bile content. Water is reabsorbed from the gall-bladder lumen during fasting, whereas it is secreted into the lumen following meal ingestion. Nevertheless, the molecular mechanism by which water is transported across the gall-bladder epithelium remains mostly unclear. RESULTS: In the present study, we investigate the presence and subcellular localization of AQP (aquaporin) water channels in the mouse gall-bladder epithelium. Considerable AQP8 mRNA was detected in the gall-bladder epithelium of mouse, calf, rabbit, guinea pig and man. Studies of subcellular localization were then addressed to the mouse gall-bladder where the transcript of a second AQP, AQP1, was also detected. Immunoblotting experiments confirmed the presence of AQP8 and AQP1 at a protein level. Immunohistochemistry showed intense expression of AQP8 and AQP1 in the gall-bladder epithelial cells where AQP8 was localized in the apical membrane, whereas AQP1 was seen both in the apical and basolateral membranes, and in vesicles located in the subapical cytoplasm. CONCLUSIONS: The pattern of subcellular distribution of AQP8 and AQP1 strongly corroborates the hypothesis of a transcellular route for the movement of water across the gall-bladder epithelium. Osmotic water would cross the apical membrane through AQP8 and AQP1, although AQP1 would be the facilitated pathway for the movement of water across the basolateral membrane. The presence of two distinct AQPs in the apical membrane is an unusual finding and may relate to the membrane's ability both to absorb and secrete fluid. It is tempting to hypothesize that AQP1 is hormonally translocated to the gall-bladder apical membrane to secrete water as in the bile duct epithelium, a functional homologue of the gall-bladder epithelium, whereas apical AQP8 may account for the absorption of water from gall-bladder bile.

Amino Acid Sequence↗
PubMed2005

Water transport into bile and role in bile formation.

Formation of bile and generation of bile flow are driven by the active secretion of bile salts (BS), lipids and electrolytes into the canalicular and bile duct lumens followed by the osmotic movement of water. Although the transporting proteins involved in solute secretion have been cloned and their coordinated interplay defined both in health and disease, boosted by the discovery of the aquaporin water channels, only recently has considerable attention been addressed to the mechanism by which water, the major component of bile (> 95%), moves across the hepatobiliary epithelia. This review summarizes the novel acquisitions in liver membrane water transport and functional participation of aquaporin water channels in multiple aspects of hepatobiliary fluid balance. Emerging evidences suggesting involvement of aquaporins in the metabolic homeostasis of the hepatobiliary tract are also discussed.

Animals↗
PubMed2005

Modulation of cholesterol crystallization in bile. Implications for non-surgical treatment of cholesterol gallstone disease.

The first step in cholesterol gallstone disease is precipitation of cholesterol crystals in bile. In gallbladder bile. cholesterol is normally solubilized together with bile salts and phospholipids to form mixed micellar structures. When cholesterol in bile is in excess, vesicles (i.e. phospholipid-cholesterol globular structures: liquid crystals) form which become supersaturated in cholesterol. Early aggregation and precipitation of cholesterol molecules into submicroscopic nuclei occurs from these supersaturated vesicles. This crucial step is followed by precipitation and agglomeration of cholesterol crystals which then become visible at light microscopy. Here we describe the mechanism of cholesterol crystallization and its modulation in vivo and in vitro. Recent advances on the role of ursodeoxycholate as an agent preventing the precipitation of cholesterol crystals in bile will be highligthed.

Animals↗
PubMed2005

Contribution of canalicular glutathione efflux to bile formation. From cholestasis associated alterations to pharmacological intervention to modify bile flow.

At least one third of the bile flow is driven osmotically by the amount of hepatic glutathione excreted into canalicular spaces. Beyond the importance of this secretory mechanism for bile formation, the excretion of glutathione is an important way to discharge toxic anionic compounds deriving from liver metabolism of exogenous and endogenous substances. Thus, biliary secretion of glutathione and its conjugates really works as a major detoxification system for the hepatocytes. Derangement of hepatic and/or biliary glutathione status can occur in several experimental animal models of liver injury and in human diseases. In the present review, we will focus on mechanisms of bile glutathione efflux and changes associated with cholestatic conditions. Novel findings on the role of water channels and of the multidrug resistant proteins in bile salt-independent bile formation, will also be discussed. New routes of intervention to modify bile flow for therapeutic purposes are considered.

Animals↗