Obesity-dependent metabolic signatures associated with nonalcoholic fatty liver disease progression.

Our understanding of the mechanisms by which nonalcoholic fatty liver disease (NAFLD) progresses from simple steatosis to steatohepatitis (NASH) is still very limited. Despite the growing number of studies linking the disease with altered serum metabolite levels, an obstacle to the development of metabolome-based NAFLD predictors has been the lack of large cohort data from biopsy-proven patients matched for key metabolic features such as obesity. We studied 467 biopsied individuals with normal liver histology (n=90) or diagnosed with NAFLD (steatosis, n=246; NASH, n=131), randomly divided into estimation (80% of all patients) and validation (20% of all patients) groups. Qualitative determinations of 540 serum metabolite variables were performed using ultraperformance liquid chromatography coupled to mass spectrometry (UPLC-MS). The metabolic profile was dependent on patient body-mass index (BMI), suggesting that the NAFLD pathogenesis mechanism may be quite different depending on an individual's level of obesity. A BMI-stratified multivariate model based on the NAFLD serum metabolic profile was used to separate patients with and without NASH. The area under the receiver operating characteristic curve was 0.87 in the estimation and 0.85 in the validation group. The cutoff (0.54) corresponding to maximum average diagnostic accuracy (0.82) predicted NASH with a sensitivity of 0.71 and a specificity of 0.92 (negative/positive predictive values=0.82/0.84). The present data, indicating that a BMI-dependent serum metabolic profile may be able to reliably distinguish NASH from steatosis patients, have significant implications for the development of NASH biomarkers and potential novel targets for therapeutic intervention.

Patients with cirrhosis and ascites have false values of bone density: implications for the diagnosis of osteoporosis.

UNLABELLED: The effect of ascites on bone densitometry has been assessed in 25 patients with advanced cirrhosis, and it was concluded that ascites over 4 l causes inaccuracy of BMD measurements, particularly at the lumbar spine. This fact must be considered when assessing bone mass in patients with decompensated cirrhosis. INTRODUCTION: Bone mineral density (BMD) measured by dual-energy x-ray absorptiometry (DXA) is the best procedure for assessment of osteoporosis and fracture risk, but BMD values at the central skeleton may be influenced by changes in soft tissues. Therefore, we have studied the effect of ascites on BMD. METHODS: BMD was measured by DXA at the lumbar spine, femoral neck and total hip, just before and shortly after therapeutic paracentesis in 25 patients with advanced liver cirrhosis. Changes in BMD, lean and fat mass, abdominal diameter and weight, as well as the amount of removed ascites were measured. RESULTS: The amount of drained ascites was 6.6 ± 0.5 l (range: 3.0 to 12.7 l). After paracentesis, BMD increased at the lumbar spine (from 0.944 ± 0.035 to 0.997 ± 0.038 g/cm(2), p < 0.001) and at the total hip (from 0.913 ± 0.036 to 0.926 ± 0.036 g/cm(2), p < 0.01). Patients with a volume of drained ascites higher than 4 l showed a significant increase in lumbar BMD (7.0%), compared with patients with a lower amount (1.5%) (p < 0.03). The decrease in total soft tissue mass correlated with the amount of removed ascites (r = 0.951, p < 0.001). Diagnosis of osteoporosis or osteopenia changed after paracentesis in 12% of patients. CONCLUSION: Ascites over 4 l causes inaccuracy of BMD measurements, particularly at the lumbar spine. This fact must be considered when assessing bone mass in patients with advanced cirrhosis.

Hereditary hepatic and systemic amyloidosis caused by a new deletion/insertion mutation in the apolipoprotein AI gene.

We report a Spanish family with autosomal-dominant non-neuropathic hereditary amyloidosis with a unique hepatic presentation and death from liver failure, usually by the sixth decade. The disease is caused by a previously unreported deletion/insertion mutation in exon 4 of the apolipoprotein AI (apoAI) gene encoding loss of residues 60-71 of normal mature apoAI and insertion at that position of two new residues, ValThr. Affected individuals are heterozygous for this mutation and have both normal apoAI and variant molecules bearing one extra positive charge, as predicted from the DNA sequence. The amyloid fibrils are composed exclusively of NH2-terminal fragments of the variant, ending mainly at positions corresponding to residues 83 and 92 in the mature wild-type sequence. Amyloid fibrils derived from the other three known amyloidogenic apoAI variants are also composed of similar NH2-terminal fragments. All known amyloidogenic apoAI variants carry one extra positive charge in this region, suggesting that it may be responsible for their enhanced amyloidogenicity. In addition to causing a new phenotype, this is the first deletion mutation to be described in association with hereditary amyloidosis and it significantly extends the value of the apoAI model for investigation of molecular mechanisms of amyloid fibrillogenesis.

Bone mass improves in alcoholics after 2 years of abstinence.

To evaluate the effect of abstinence on bone mass and bone mineral metabolism in chronic alcoholics, a 2 year longitudinal follow-up study was carried out in a group of 30 chronic alcoholic males who started a rehabilitation program. Lumbar and femoral bone mineral density (BMD) and serum levels of osteocalcin and 25-hydroxyvitamin D were measured at entry and after 1 and 2 years in all patients. Circulating cortisol and parathyroid hormone were measured in 14 and 6 patients, respectively, at entry and every year. Testosterone was measured in 18 patients at entry and after 1 year. At entry, lumbar BMD was significantly lower in alcoholics (1.06 +/- 0.03 g/cm2) than in age-matched healthy men (1.22 +/- 0.03 g/cm2; p < 0.001). Circulating osteocalcin and vitamin D levels were also significantly lower in alcoholics than in controls. Lumbar and femoral neck BMD increased in alcoholics after 2 years of abstinence (lumbar BMD, mean +/- SEM, 1.06 +/- 0.03 to 1.10 +/- 0.04 g/cm2, p < 0.05; femoral BMD, 0.82 +/- 0.02 to 0.84 +/- 0.02 g/cm2; p < 0.02). Moreover, lumbar BMD increased in alcoholics (2.9 +/- 1.4%) and decreased in controls (-1.1 +/- 0.2%; p < 0.02). Femoral BMD also increased in alcoholics (2.8 +/- 1.0%) but the expected mean decrease of -0.92% was found in healthy age-matched males. Baseline low osteocalcin levels (5.1 +/- 0.6 ng/ml) increased after 1 year (8.6 +/- 0.5 ng/ml, p < 0.001) and 2 years of abstinence (9.5 +/- 0.7 ng/ml, p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Interactions between alcohol and gastric metabolizing enzymes: practical implications.

It has been demonstrated recently that some portion of ingested alcohol does not enter the systemic circulation and is not retained in the gastrointestinal tract; instead, gastric oxidation or first-pass metabolism of ethanol occurs in the stomach, catalyzed by gastric alcohol dehydrogenase. First-pass metabolism of ethanol is minimal in the fasting state; it is lower in women than in men, and in alcoholics than in nonalcoholics; and it is abolished in patients after subtotal gastrectomy. In addition, some drugs may affect first-pass ethanol metabolism. Studies of the effects of H2-receptor antagonists on blood ethanol levels are reviewed. It is concluded that some H2-receptor antagonists (cimetidine and nizatidine, in particular) can inhibit gastric ethanol oxidation and thus increase blood alcohol levels after drinking. The clinical and medicolegal implications of these findings are discussed.

Serum amino-terminal propeptide of type III procollagen levels in chronic pancreatitis.

The severity of pancreatic fibrosis, a characteristic feature of patients with chronic pancreatitis (CP), can be assessed only by direct histologic analysis of pancreatic tissue. Since serum levels of the amino-terminal type III procollagen propeptide (PIIIP) can reflect the degree of fibrogenic activity in several diseases associated with fibrosis, the current study was aimed at investigating whether PIIIP are increased in chronic pancreatitis, the relationship between PIIIP and pancreatic fibrogenic activity, and the influence of pancreatectomy, pancreatic exocrine function, and duration of disease on PIIIP levels. Serum PIIIP was measured in 18 patients with CP (15 without liver disease and three with cholestasis) and in 21 healthy controls. The effect of pancreatectomy on PIIIP was evaluated in seven patients, in whom PIIIP was measured immediately before and 2 months after surgery. Prolylhydroxylase (PHase) activity as an index of pancreatic fibrogenesis was evaluated in pancreatic tissue from 11 patients who had undergone subtotal pancreatectomy and from 11 organ donors. The bentiromide (BT)-PABA test as an index of exocrine pancreatic function was measured in all patients. PIIIP was significantly higher in patients who had or had not undergone pancreatectomy (17.3 +/- 4.0 and 25 +/- 11.4 ng/ml, respectively) than in controls (12.3 +/- 3.1 ng/ml) (p < 0.001). PIIIP decreased significantly after pancreatectomy (before, 32.0 +/- 9.3 ng/ml; after, 18.4 +/- 4.8 ng/ml; p = 0.005). PHase was significantly higher in patients (773 +/- 250 cpm/mg protein) than in controls (405 +/- 121 cpm/mg protein) (p < 0.001). PIIIP was correlated with pancreatic PHase (r = 0.7, p = 0.001) but not with BT-PABA or with the duration of the disease. In conclusion, serum PIIIP levels are increased in patients with CP and reflect the severity of pancreatic fibrogenic activity. No relationship between the serum PIIIP levels and the pancreatic exocrine function and duration of disease was found.

Synthesis and degradation of collagen in pancreatic fibrogenesis.

The mechanism of fibrogenesis in the pancreas is not well known. We analyzed the role of prolylhydroxylase and collagenase activities in the development of fibrosis in chronic alcoholic pancreatitis (CAP). Nineteen patients with CAP and 11 controls (organ donors) with normal pancreatic histology were included in the study. Pancreatic tissue was obtained from all subjects to measure (a) area of fibrosis (histomorphometric method); (b) prolylhydroxylase activity (PHase), which reflects the intracellular synthesis of collagen (Hutton's method); and (c) collagenase activity, which reflects the degradation of collagen (collagenase assay system, 3H). The percentage of the fibrosis area in relation to the total area of pancreatic tissue was significantly higher in CAP than in the control group (70.6+/-20.2% vs. 4.6+/-1.8%; p<0.001). Mean pancreatic PHase activity was also significantly higher in CAP than in the control group (775+/-258 cpm/mg protein/h vs. 405+/-151 cpm/mg protein/h; p<0.001). The collagenase activity was significantly lower in CAP than in the control group (8.7+/-3.5 cpm/cpm added/mg protein vs. 18.0+/-3.9 cpm/cpm added/mg protein; p<0.001). A significant correlation was observed between percentage fibrosis evaluated histomorphometrically and PHase activity in all patients (r = 0.72; p<0.001), and between PHase and collagenase activities in controls (r = 0.70; p = 0.024), but not in CAP. Pancreatic tissue in CAP has an increased fibrogenic activity and an impaired collagen-degradation capacity. These findings might explain the excessive development of fibrosis in CAP.

Role of zinc in the process of pancreatic fibrosis in chronic alcoholic pancreatitis.

Zinc acts as a cofactor in many enzymatic processes, including collagen synthesis. The observation of increased activity of prolylhydroxylase (PHase), an enzyme that takes part in the synthesis of collagen, in zinc-depleted liver tissue suggests that zinc deficiency is associated with hepatic collagen deposition. The pancreatic zinc content in chronic alcoholic pancreatitis (CAP) is still unknown. The objectives of this study were (a) To assess zinc concentrations in the pancreatic tissue in CAP; (b) to establish a possible relation between pancreatic zinc content, fibrosis, and PHase activity; and (c) to evaluate the relation between serum and pancreatic zinc levels. Sixteen surgical specimens of pancreatic tissue from patients with CAP were analyzed; control pancreatic samples from 11 organ donors were also studied. Zinc concentration, PHase activity, and the amount of fibrous tissue were assessed in the pancreatic tissue of each individual. The amount of fiber deposited in the pancreas in CAP was 68.4 +/- 19.8%, and that of the control group, 5 +/- 2% (p < 0.001). PHase activity in CAP was 754 +/- 230 cpm/mg of protein and that of the control group was 405 +/- 151 cpm/mg of protein (p < 0.001). The amount of pancreatic zinc in the former was 15.0 +/- 9.7 micrograms/g of tissue and that of the latter was 28.1 +/- 18.1 micrograms/g of tissue (p = 0.023). Serum zinc levels were similar in both groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Hepatic fibrogenic activity in chronic alcoholic pancreatitis.

The prevalence and the mechanisms of hepatic fibrosis in chronic alcoholic pancreatitis remain uncertain. The aim of this study was to investigate the fibrogenic activity of the liver in patients with chronic pancreatitis and its relation with either the alcohol or cholestasis. Liver biopsies were obtained from 16 patients with chronic pancreatitis at the time of surgery and from 10 organ donors. Samples were processed for histologic examination to assess the presence and extent of fibrosis, inflammatory reactions, and cholestasis- and alcohol-related lesions. In other samples, the collagen content was measured by morphometry, and prolylhydroxylase activity was determined. Liver-function tests, ultrasonography, and endoscopic retrograde cholangiopancreatography were performed before surgery in all the patients. Of patients with chronic pancreatitis, 75% had significantly greater hepatic fibrosis and prolylhydroxylase activity than the control group. Moreover, prolylhydroxylase activity in patients with chronic pancreatitis was higher in those with cholestasis or partial obstruction of the common bile duct than in those without cholestasis or partial obstruction of the common bile duct. Both the fibrogenic activity and the collagen content in the livers of patients with chronic alcoholic pancreatitis are significantly increased, even in those without histologic lesions, and these alterations may be secondary to a partial occlusion of the common bile duct.

The contribution of the stomach to ethanol oxidation in the rat.

To estimate the amount of ethanol that can be oxidized in the stomach, steady-state conditions were created in a group of fed rats by giving a loading dose of ethanol (2 g/kg body wt I.V.) followed by continuous infusion either intravenously or intragastrically. The rate of ethanol oxidation was calculated from the rate of infusion required to maintain steady blood levels of approximately 30 mM for at least 3 hours. Gastrointestinal ethanol concentrations and total contents also remained steady. The rate of ethanol oxidation was 19.3% faster during intragastric than during intravenous infusion (p less than 0.01). When measured at the prevailing luminal ethanol concentration (145 mM) and expressed per body weight, the gastric ADH activity represented 14% of the hepatic activity at 30 mM ethanol, suggesting that gastric ADH activity could account for most of the increased rate of oxidation when ethanol is given intragastrically. Thus, gastric ethanol oxidation by a high Km ADH in the rat represents a significant fraction of the total rate of ethanol oxidation and it is therefore one of the factors which determines the bioavailability of orally administered ethanol.

Effects of ethanol feeding and malnutrition on collagen synthesizing and degrading enzymes in rat pancreas.

This study was performed to delineate the combined effects of a low-fat diet and chronic ethanol ingestion on collagen metabolism in rat pancreas. Rats fed a very low-fat diet (5% of total calories as lipid) for 12 weeks developed malnutrition as judged by weight loss (-33% of the initial body weight) and low serum albumin and amylase levels. The pancreas of malnourished rats showed increased collagenase activity with respect to animals fed a 35% lipid diet (p < 0.05). Hydroxyproline content was higher in the pancreas of malnourished rats and collagenase activity correlated well with hydroxyproline content (r = 0.57, p = 0.0013). Ethanol feeding for 12 weeks, regardless of the nutritional state of the rats, did not change the synthesis and degradation rates of collagen in the pancreas. The present study suggests that malnutrition may have profound effects on collagen metabolism.

Influence of zinc intake on hepatic lipid peroxidation and metallothioneins in alcoholic rats: relationship to collagen synthesis.

Hepatic lipid peroxidation, metallothioneins, collagen and proline hydroxylase activity were investigated in 16 ethanol-fed rats and in 16 control animals. The rats were further divided into three groups to receive either a standard diet, a zinc-deficient diet or a zinc-supplemented diet. The animals were sacrificed at week 12 of the experiment for histological and biochemical assessments. Hepatic tissue examination indicated that oral zinc supplementation was associated with a decrease in lipid peroxidation, collagen deposition and proline hydroxylase activity together with an increase in metallothionein concentration in alcoholic rats. There were no significant differences in lipid peroxidation in the control group in relation to the diet. Zinc supplementation was associated with increased concentrations of hepatic metallothioneins together with decreased concentrations of proline-hydroxylase and collagen but to a lesser degree than in alcoholic animals. These results indicate that zinc is an efficient hepato-protective agent against lipid peroxidation in alcoholic rats and its effect may be, in part, mediated by the activation of metallothionein synthesis. Also, lipid peroxidation may be related to changes in hepatic collagen synthesis.

[Epidemiology of hepatitis B in hospital personnel (author's transl)]. / Epidemiología de la hepatitis B en personal hospitalario.

This is a seroepidemiological study of infection by viral hepatitis type B affecting sanitary personnel in a general hospital with the objective of determining the occupational risk factor in the acquisition of this disease. Of the 791 subjects who participated in the study, 146 (18.5 percent) showed signs of present or past infection due to virus B (HBsAg or anti-HBs positive by RIA). Seropositivity in hospital personnel was significantly higher that observed in the population of 834 volunteer blood donors (12 percent). The greater frequency of signs of infection was observed in those who had frequent contact with blood and its derivates, and in those who had been working more than 5 years in the hospital. The occupational category with the greatest risk of acquisition of this infection is cleaning personnel, followed by physicians and nurses; and the work areas of greatest risk are the blood bank and the laboratory. The results of this epidemiological survey suggest that viral hepatitis acquired before the initiation of the hospital work are not predominantly B, while those acquired during hospital work are predominantly of type B.

[Prevalence and factors associated to the presence of fatty liver in apparently healthy adult men]. / Prevalencia y factores asociados a la presencia de esteatosis hepática en varones adultos aparentemente sanos.

BACKGROUND: Alcohol intake in one of the factors associated with fatty liver, although its contribution as well as other factors have not been completely established. Therefore the aim of this study was to assess the prevalence and associated factors for fatty liver diagnosed by ultrasonography. SUBJECTS AND METHODS: 1,801 presumably healthy male workers (age range 18-60 years). A complete physical and laboratory investigations, including HBsAg and anti-HCV antibodies, a detailed interview on alcohol intake, and an abdominal ultrasound examination were performed in all cases. Diagnosis of fatty liver was based on defined ultrasonographic criteria. RESULTS: Eighty eight cases were excluded because of the HBsAg or anti-HCV positivity or incomplete ultrasonography. Among the remaining 1,713 cases, 236 (13.8%; 12.2-15.4) had fatty liver. Logistic regression analysis disclosed age (RR: 1.04; CI 95%; 1.03-1.05), ethanol intake > 40 g/d (2.19; 1.81-2.65), gamma-glutamyl-transferase > 40 U/l (3.51; 2.95-4.18), body mass index > 30 (3.87; 3.22-4.66) and glycemia > 120 mg/dl (2.69; 1.85-3.90) as the risk factors for fatty liver. Fatty liver was present in 8.8% of cases who did not have obesity, diabetes or hypercholesterolemia. When the subjects with obesity, hyperglycemia or hypercholesterolemia were excluded, regression analysis confirmed age, ethanol intake and gamma-glutamyl-transferase as independent factors associated with fatty liver. CONCLUSIONS: Age, alcohol intake, obesity, and increased serum levels of glucose, cholesterol and gammaglutamyl transferase are the main factors associated with fatty liver in presumably healthy adult men.

[Class I and II histocompatibility antigens and severity of the alcoholic liver lesion]. / Antígenos de histocompatibilidad de clases I y II y gravedad de la lesión hepática alcohólica.

The association between the class I and class II histocompatibility antigens (HLA) and the severity of alcoholic liver disease was studied in 102 alcoholic patients (64 males and 38 females) with liver disease. According to histologic diagnosis 41 patients had a mild hepatic lesion (12 with minimum changes, 15 with steatosis and 14 with fibrosis) and 61 patients had severe hepatic lesion (13 with alcoholic hepatitis, 35 with cirrhosis and 13 with cirrhosis and alcoholic hepatitis). No differences were found between the two groups in regards to sex, quantity and length of alcohol consumption, although the patients with mild hepatic lesion were younger than those with severe hepatic lesion (41.2 +/- 8.2 and 47.8 +/- 11.6 years, respectively). The prevalence of the A30, B16, B47, Bw56, Cw1, Cw5 and Cw7 antigens was higher in the alcoholics than in the controls, although only the A30 (12.7% vs. 4.4%, p < 0.04) and the Bw56 antigens (3.9% vs 0.1%, p < 0.001) remained significant when the p value was corrected by the number of antigens studied. These differences were due to a greater prevalence of the A30 antigens (17.0% vs. 4.4%, p < 0.001), B16 (24.3% vs. 7.5%, p < 0.01) and Bw56 (7.3% vs 0.1%, p < 0.001) in patients with mild hepatic lesion versus the controls. In contrast, these antigens were present in similar numbers in patients with severe hepatic lesion and in the controls. On the other hand, no differences were observed regarding the prevalence of the class II HLA antigens between the alcoholics and the controls, or between the two alcoholic groups. These data suggest that the alcoholics with A30, B16 and Bw56 antigens are less susceptible to developing severe liver disease.