Efficacy of a surveillance program for early detection of hepatocellular carcinoma

BACKGROUND

Contrasting data have so far been reported on the utility and efficacy of screening patients with cirrhosis for early detection of hepatocellular carcinoma (HCC). The goal of this study was to evaluate the efficacy of a regular ultrasonographic and laboratory follow-up for the early detection of small HCC, and to identify parameters correlated with a higher risk of developing HCC.

METHODS

One hundred and sixty-four consecutive patients with liver cirrhosis living in Emilia Romagna, Italy, were enrolled in the period 1989-1991. All patients underwent clinical, biochemical, and ultrasonographic evaluations at entry and at 3- and 6-month intervals during follow-up.

RESULTS

By April 1995, 34 patients had developed HCC. In 76% of the patients, ultrasonography identified HCC when it was still single and small (< 4 cm). At discriminant, logistic regression and univariate analyses, sex and the entry concentration of alkaline phosphatase, alpha-fetoprotein, gamma-glutamyl transpeptidase, and albumin were associated with a higher risk of developing HCC, whereas at multivariate analysis (Cox's model), only sex and the entry concentration of alkaline phosphatase, albumin, and alpha-fetoprotein were independently and significantly related to the appearance of HCC.

CONCLUSIONS

A regular ultrasonographic follow-up, timed at 3- to 6-month intervals according to the risk of HCC development in patients with cirrhosis, allows the detection of liver carcinoma at an early stage in a high proportion of patients, possibly improving the prognosis of the disease.

Quantification of prostate-specific antigen immunoreactivity in human breast cyst fluids

The frequency of gross cystic breast disease in premenopausal women and its possible association with increased breast cancer risk emphasises the importance of investigations relating to breast cyst fluid composition. In order to contribute to a better analysis of this medium, we have measured the presence of prostate-specific antigen immuno-reactivity in sixty-four human breast cyst fluids. Data analyses show that 35% of samples presented a level of this antigen < 0.05 micrograms/L, whereas 42 out of 64 cysts show a significant increase in the mean value of metabolically active apocrine cysts when compared to flattened cysts (p < 0.01). We report the first evidence that breast epithelium of gross cysts produces, secretes, and accumulates large amounts of prostate-specific antigen, a glycoprotein produced by prostatic tissue but recently detected in breast tumours, normal tissues, and during pregnancy. The production and intracystic accumulation of this serine protease in biosynthetically active apocrine type cyst can play a feasible role in the natural history gross cystic breast disease as well as in the mechanism of cyst formation, enlargement, and transformation.

Genetic determinants and renal mechanisms in essential hypertension

Human essential hypertension is a polygenic disease whose phenotypic expression is modulated by the environment. Though the kidney could play a major role in the initiation and maintainment of hypertension, many questions remain open. Rat models of primary hypertension provided the substantial information with experiments on kidney cross-transplantation, showing that at least a portion of hypertension could be transplanted with the kidney in all strains where such an experiment has been carried out. Data consistent with those of rats have also been obtained in humans. Many abnormalities in kidney function and cell membrane ion transport have been described in hypertensive rats and humans, but the logical sequence of events from a genetic-molecular abnormality to a cellular abnormality which causes hypertension via a modification of kidney function is difficult to prove. We established this sequence in Milan hypertensive rats using a variety of experimental techniques such as the study of isolated kidney and renal cell function, cell membrane ion transport, cross-immunisation with membrane proteins, molecular biology, genetic crosses and manipulation. Such study led to the identification of a polymorphism in the cytoskeletal protein adducin. Recently, alpha-adducin variants have been associated to both primary hypertension and salt sensitive hypertension. Finally, recent findings strongly support the hypothesis that adducin variants may affect kidney function by modulating the overall capacity of the tubular epithelial cells to transport ions through both a modification in the assembly of actin cytoskeleton, and a modulation of sodium pump activity.

The course of galactose elimination capacity in patients with alcoholic cirrhosis: possible use as a surrogate marker for death

There is increasing interest for the use of surrogate end points in the evaluation of treatments in patients with liver disease, but adequate validation is seldom available. This study aimed to describe the different course of galactose elimination capacity in patients with alcoholic cirrhosis who continued to drink or abstained from alcohol consumption during follow-up, and to validate changes in galactose elimination as a surrogate end point for death from liver-related causes. Forty-five patients with alcoholic cirrhosis (22 who continued drinking throughout the study period, and 23 who stopped drinking and were abstinent throughout the study period) were retrospectively selected among patients who had galactose elimination capacity measured at 6-month intervals. During follow-up 10 drinkers and 3 abstainers died of liver-related causes (P = .025). Abstainers showed a transient improvement in galactose elimination capacity, followed by a decrease. Continuous drinkers showed a reduction from the beginning. According to Cox's regression analyses, persistent alcohol abuse and galactose elimination capacity were separately related to the risk of death, but, when a time-dependent model was fitted containing galactose elimination capacity and persistent alcohol abuse, only the former remained significant. This implies that variations in the risk of death occurring as a consequence of abstinence from alcohol consumption may be predicted from changes in galactose elimination capacity, and that the mechanisms through which abstinence influences survival are strictly linked to the mechanisms responsible for the changes in the test. Because of the strict association of decrease in galactose elimination capacity and short survival, as proved in several series, this observation represents adherence to the criteria requested for adequacy of a surrogate end point. In conclusion, in alcoholic cirrhosis the decrease in galactose elimination capacity is an adequate surrogate end point for death from liver-related causes, which is worth testing in other conditions and in response to other treatments.

Estrogen and progesterone receptors in breast cancer: comparison between enzyme immunoassay and computer-assisted image analysis of immunocytochemical assay

Evaluation of estrogen (ER) and progesterone (PR) receptor content is now an important procedure in the management of breast cancer patients. Production of monoclonal antibodies to ER and PR has permitted development of an enzyme immunoassay (EIA) and immunocytochemical assay (ICA). This study compared the results of ICA and EIA to evaluate ER and PR in 197 breast cancers using the same monoclonal antibodies. The ICA results were obtained by automated computer-assisted image analysis using CAS 200. The cut-off values adopted were 15 fmol/mg protein for EIA and 10% of the positive neoplastic area of the nuclei for ICA. For statistical analysis, Spearman's correlation coefficient and chi 2 were used. There was good correlation between ICA and EIA for both ER (r = 0.714; p < 0.0001) and PR (r = 0.815; P < 0.0001). Of 197 tumors, 136 (69.04%) were ER-ICA+, and 138 (70.05%) were ER-EIA+; 111 (56.35%) were PR-ICA+, and 115 (58.38%) were PR-EIA+. Results were concordant, positive or negative with both methods, in 175 cases for ER and in 173 cases for PR. ER and PR results were only discordant in 22 and 24 cases, respectively. Concordance of results obtained by the two methods was 88.83% (P < 0.0001) for ER and 87.81% (P < 0.0001) for PR. Correlation of results obtained by EIA and ICA to determine ER and PR was good. The data obtained suggest that ICA with automated image analysis is an effective means for evaluating ER and PR content in human breast cancer, especially when, as happens ever more frequently nowadays, the tumor is too small to perform EIA or when retrospective studies are performed.

Efficacy of a surveillance program for early detection of hepatocellular carcinoma

BACKGROUND

Contrasting data have so far been reported on the utility and efficacy of screening patients with cirrhosis for early detection of hepatocellular carcinoma (HCC). The goal of this study was to evaluate the efficacy of a regular ultrasonographic and laboratory follow-up for the early detection of small HCC, and to identify parameters correlated with a higher risk of developing HCC.

METHODS

One hundred and sixty-four consecutive patients with liver cirrhosis living in Emilia Romagna, Italy, were enrolled in the period 1989-1991. All patients underwent clinical, biochemical, and ultrasonographic evaluations at entry and at 3- and 6-month intervals during follow-up.

RESULTS

By April 1995, 34 patients had developed HCC. In 76% of the patients, ultrasonography identified HCC when it was still single and small (< 4 cm). At discriminant, logistic regression and univariate analyses, sex and the entry concentration of alkaline phosphatase, alpha-fetoprotein, gamma-glutamyl transpeptidase, and albumin were associated with a higher risk of developing HCC, whereas at multivariate analysis (Cox's model), only sex and the entry concentration of alkaline phosphatase, albumin, and alpha-fetoprotein were independently and significantly related to the appearance of HCC.

CONCLUSIONS

A regular ultrasonographic follow-up, timed at 3- to 6-month intervals according to the risk of HCC development in patients with cirrhosis, allows the detection of liver carcinoma at an early stage in a high proportion of patients, possibly improving the prognosis of the disease.

Hypertension may be transplanted with the kidney in humans: a long-term historical prospective follow-up of recipients grafted with kidneys coming from donors with or without hypertension in their families

In several genetic hypertensive rat strains, transplantation studies have established that the kidney carries at least a portion of the genetic message for hypertension. In man it has, of course, been more difficult to obtain clearcut results. This historical prospective observational study, double-blinded for knowledge of donors' and recipients' family history for hypertension, concerns 85 transplanted patients, not treated with cyclosporine and with stable renal function, followed up for an average of 8 yr. Both the donors' and the recipients' families were carefully characterized for presence or absence of hypertension. After transplantation, in recipients without hypertension in their own families, a kidney coming from a "hypertensive" family determines less withdrawal and more introduction of antihypertensive therapy (AHT) than a kidney from a "normotensive" family (odds ratio for AHT introduction 5.0, confidence interval, 1.4 to 17.8; P = 0.017). In recipients with familial hypertension, the origin of the kidney does not influence the prevalence of hypertension after transplantation. More detailed analyses show that, in recipients without familial hypertension, the transplantation of a "hypertensive" kidney determines a tenfold larger increase in the requirement of antihypertensive therapy than the transplantation of a "normotensive" kidney, to obtain a similar blood pressure control (P = 0.003). This results is confirmed by the analysis of time-profile trends for antihypertensive therapy, adjusted for missing data, in the most clinically stable period (2nd to 10th yr after transplantation). The transmission of familial hypertension with the kidney is thus seen only in recipients coming from "normotensive" families, because a familial tendency for hypertension blunts the effect of receiving a "hypertensive" kidney.

Migratory Response of Human NK Cells to Monocyte-Chemotactic Proteins

NK cells are present mostly in blood and spleen but under certain pathological and physiological conditions rapidly accumulate at extrahematic sites. The present study investigates the responsiveness of NK cells to C-C chemokines and the mechanisms of emigration from the bloodstream. MCP-1 induced migration across polycarbonate filters of IL-2-activated NK cells, whereas it was a weak attractant for unstimulated cells. The related chemokines MCP-2 and MCP-3 were also active. IL-2-activated NK cells showed specific binding sites for labeled MCP-1, and cell migration was inhibited by both cholera and Bordetella pertussis toxins. In agreement with functional assays the expression of mRNA specific for MCP-1 receptors was detectable only in IL-2-activated NK cells. The ability of NK cells to respond to MCP-1 and related chemokines may be one important determinant of NK cell emigration and recruitment in tissues.

Hypertension-associated point mutations in the adducin alpha and beta subunits affect actin cytoskeleton and ion transport

The adducin heterodimer is a protein affecting the assembly of the actin-based cytoskeleton. Point mutations in rat adducin alpha (F316Y) and beta (Q529R) subunits are involved in a form of rat primary hypertension (MHS) associated with faster kidney tubular ion transport. A role for adducin in human primary hypertension has also been suggested. By studying the interaction of actin with purified normal and mutated adducin in a cell-free system and the actin assembly in rat kidney epithelial cells (NRK-52E) transfected with mutated rat adducin cDNA, we show that the adducin isoforms differentially modulate: (a) actin assembly both in a cell-free system and within transfected cells; (b) topography of alpha V integrin together with focal contact proteins; and (c) Na-K pump activity at V(max) (faster with the mutated isoforms, 1281 +/- 90 vs 841 +/- 30 nmol K/h.mg pt., P < 0.0001). This co-modulation suggests a role for adducin in the constitutive capacity of the epithelia both to transport ions and to expose adhesion molecules. These findings may also lead to the understanding of the relation between adducin polymorphism and blood pressure and to the development of new approaches to the study of hypertension-associated organ damage.

Renal mechanisms of genetic hypertension: from the molecular level to the intact organism

Human primary hypertension is a polygenic disease; its phenotypic expression is modulated by the environment. Though the kidney can play a major role in the initiation and maintainance of hypertension, many questions remain open. Kidney cross-transplantation demonstrated that hypertension can be transplanted with the kidney in all strains of genetically hypertensive rats where such experiments have been carried out. Data consistent with those in rats were also obtained in humans. Many abnormalities in kidney function and ion transport were described in hypertensive rats and humans, but the logical sequence from genetic-molecular to cellular abnormality that causes hypertension via modification of kidney function is difficult to prove. We established this sequence in Milan hypertensive rats using a variety of experimental techniques (isolated kidney and renal cell function, cell membrane ion transport, cross-immunization with membrane proteins, molecular biology, genetic crosses and manipulation). Such studies led to the identification of a polymorphism in the cytoskeletal protein adducin. This polymorphism seems involved in blood pressure regulation both in rats and humans. Preliminary results suggest that adducin polymorphism affects kidney function by modulating the overall capacity of tubular epithelial cells to transport ions modifying the assembly of actin cytoskeleton.

Laparoscopic surgical lymphadenectomies in urological tumours

In the last few years laparoscopie surgery has also been used in urological pathologies. Various types of operations have been performed with this technique, but only recently has there been an attempt to give precise indications. Laparoscopy is being used to carry out pelvic lymphadenectomy for cancer of the prostate, the penis and the female urethra, and retroperitoneal lymphadenectomy for non-seminomatous germinal cancer of the testis. The aim of this work, which reports the authors’ experience with this technique, is to define its advantages and limitations in order to identify correct indications.

Association between plasma membrane (Ca+Mg) ATPase and calpain/calpastatin system in rat erythrocytes

We studied the activity of plasma membrane (Ca+Mg)ATPase from erythrocytes of Milan hypertensive rat strain (MHS) and Milan low calpastatin rat strain (MLCS), that show an activity level of the specific calpain inhibitor, calpastatin, about five fold reduced in comparison with the Milan normotensive rat strain (MNS), while the protease activity level is similar. This imbalance of calpain:calpastatin ratio leads to a decrease of the erythrocyte plasma membrane (Ca+Mg)ATPase activity and to the appearance of 124 kDa fragments, which are the typical products of proteolytic calpain action on the 136 kDa (Ca+Mg)ATPase native form.

The galactose elimination capacity test: a study of the technique based on the analysis of 868 measurements

OBJECTIVES

Our objective in this study was to analyze the correspondence of galactose concentration-on-time-decay curve to theoretical assumptions and the confidence limits of the determination of galactose elimination capacity.

METHODS

We analyzed a retrospective series of 868 galactose elimination tests, performed on subjects with and without liver disease. Zero-order kinetics of galactose elimination was tested by comparison of the residual variance of linear regression with that obtained after quadratic transformation. The uncertainty in determination of galactose elimination capacity was calculated on the regression line by computing the 95% confidence limits of the estimate.

RESULTS

The time-course of galactose concentration suggested an initial uneven distribution, and the first (20-min) data point deviated significantly from the regression. The galactose decay curve in plasma rejected linearity in 13% of tests; after exclusion of the first data-point, linearity was rejected in only 3% of cases. The 95% confidence interval of galactose elimination capacity was on average +/- 16%, but in individual tests it was as large as +/- 60-80%. The uncertainty of the test was not affected by linearity. It was larger, with poor fitting of the experimental data on the regression of galactose concentration on time, low number of data points, and low galactose elimination. It was maintained within +/- 20% only when residual variance was > or = 2% of total variance (nearly 50% of tests).

CONCLUSION

The methodology for the determination of galactose elimination capacity leads to considerable uncertainty as to the final result, which must be considered whenever the test is used for clinical purposes in the decision-making process. It tends to be larger in patients with advanced disease and can be accurately calculated so as to contribute to a proper evaluation of the test result.

Zinc supplementation and amino acid-nitrogen metabolism in patients with advanced cirrhosis

Zinc deficiency is common in cirrhosis and has been involved in the altered nitrogen metabolism. In this study, we measured the effects of zinc supplementation on the dynamics of amino acid-derived urea synthesis in cirrhosis with mild or latent encephalopathy. The hepatic conversion of amino acids into urea was studied in eight patients with advanced cirrhosis under controlled conditions of substrate availability (continuous alanine infusion), before and after 3-month oral zinc sulfate supplementation (600 mg/d). Eight more patients, matched for hepatocellular failure and encephalopathy, served as controls. Plasma zinc levels were reduced in all patients and returned to normal after oral zinc. The alanine-stimulated urea nitrogen synthesis rate in relation to alpha-amino-N concentration--the functional hepatic nitrogen clearance--increased by 25% after zinc supplementation, i.e., more urea was produced at any alpha-amino-N concentration. Basal and alanine-induced glucagon decreased by 50%, and the ammonia response to alanine decreased by 30%. Psychometric tests improved, as did routine and dynamic liver function tests and the Child-Pugh score. Also, the plasma concentration of lipid peroxides was reduced by zinc. No significant changes were observed in the control group. Our data indicate that long-term oral zinc speeds up the kinetics of urea formation from amino acids and ammonia. Changes in the hormonal drive and/or the antioxidant activity of zinc might be involved in the general improvement in liver function, whereas the beneficial effects on encephalopathy might stem from decreased ammonia.

Modifications of diazepam binding inhibitor and peripheral benzodiazepine receptors in the lymphocytes of epileptic patients

Recent experimental evidence has suggested that peripheral benzodiazepine receptors (PBR) may play a role in epilepsy and antiepileptic drug action. Since PBR are also present in circulating lymphocytes, and may interact with anticonvulsant drugs, this study was designed to look for possible modifications of these receptors and their endogenous ligand diazepam binding inhibitor (DBI) in the lymphocytes of epileptic patients treated with various drugs. PBR levels were 50% to 80% higher in patients treated with carbamazepine, phenobarbital and valproic acid than in controls and untreated epileptics. DBI levels were significantly increased in the lymphocytes of untreated patients, and showed only a slight further increase after anticonvulsant therapy. The possibility that PBR and DBI modifications in the lymphocytes of epileptic patients may be linked to the immunological alterations reported in these patients and/or may represent possible markers of neurochemical modifications in the central nervous system is discussed.

Erythrocytic calpain-calpastatin system in Alzheimer's disease

Calpains, calcium activated neutral proteases (CANP), and calpastatin (CAST), their specific inhibitor, are involved in the proteolysis of amyloid precursor protein (APP), which is thought to be abnormal in Alzheimer's disease (AD). We studied the CANP/CAST system in erythrocytes of 14 clinically probable AD patients, 11 young and 14 old controls. CANP and CAST activities in the control subjects significantly correlated with increasing age; old controls showed a significant increase in CANP and CAST activities compared to young controls. Values of CANP and CAST activities in AD patients were similar to those of young controls. The physiological gage-related increase in proteolysis seems to be lost in AD patients, and this could play a role in the pathogenesis of the disease. However, due to the overlap of results between patients and controls, we could not reliably differentiate the healthy from the disease state on the basis of erythrocytic CANP/CAST activity.

Overview of randomized clinical trials of oral branched-chain amino acid treatment in chronic hepatic encephalopathy

BACKGROUND

The role of oral branched-chain amino acid supplements in the prevention and treatment of chronic hepatic encephalopathy is not yet established, and conflicting opinions are expressed in authoritative textbooks. We aimed to review and pool the published controlled studies by means of meta-analytical techniques.

METHODS

A computerized search of published papers identified nine studies, controlled against placebo, energy, alimentary proteins, or casein. Their quality score was calculated according to the protocol of Chalmers. The value of the portal-systemic encephalopathy index was chosen as main outcome, because of lack of more significant clinical outcomes. To cope with differences in trial design and data presentation, individual data were requested to authors.

RESULTS

After 18 months, we received the individual data of only two studies, thus precluding any meta-analysis. Two studies, accounting for over 60% of total enrolled patients, were in favor of branched-chain amino acids. Their quality score was much better than that of the remaining seven negative small studies, carrying a significant risk of type II error.

CONCLUSIONS

Based on the results of the two largest, long-term studies, the use of oral branched-chain amino acids in the prevention and treatment of chronic encephalopathy may only be proposed for patients with advanced cirrhosis, intolerant to alimentary proteins. Large, multicenter, long-term studies, considering more important clinical outcomes, are needed to provide definite answers to an aged question.

Triple therapy with azithromycin, omeprazole, and amoxicillin is highly effective in the eradication of Helicobacter pylori: a controlled trial versus omeprazole plus amoxicillin

BACKGROUND

Azithromycin is a new-generation, acid-stable macrolide antibiotic that achieves remarkably high concentrations in gastric tissue, persisting above the MIC90 for Helicobacter pylori over a 5-day period after a single 500-mg oral dose.

METHODS

We evaluated a new metronidazole-free triple therapy with omeprazole 20 mg b.i.d. plus amoxicillin 1 g b.i.d. (both for 14 days) and azithromycin 500 mg mane (for the first 3 days only) (group I) versus double therapy with omeprazole 20 mg b.i.d. plus amoxicillin 1 g t.i.d., both for 14 days (group II). H. pylori status was determined by urease test and histology before and 6 wk after completion of therapy.

RESULTS

Ninety-two patients with peptic ulcer disease or nonulcer dyspepsia completed the study. H. pylori infection was eradicated in 44 (91.6%) of 48 patients randomized to receive triple therapy versus 26 (59.1%) of 44 who received double therapy (p < 0.001). Smoking, but not omeprazole pretreatment, proved to be a risk factor for treatment failure only in the double-therapy group (p = 0.05). All ulcers healed by the time of the 8-wk endoscopic control. Side effects, usually minor, were recorded in 12.5% and 9.1% of patients, respectively (NS), but therapy had to be discontinued in one patient in group I and in three in group II (NS).

CONCLUSIONS

Two-week triple therapy with omeprazole, amoxicillin, and (for the first 3 days) low-dose azithromycin is highly effective in eradicating H. pylori. This regimen is safe and well-tolerated, and we recommend that it be used as first-line treatment, as an alternative to less-effective omeprazole-amoxicillin double therapy. Moreover, azithromycin appears to be a new, promising antibiotic for future innovative anti-H. pylori combinations.

Antihypertensive effects of lercanidipine in experimental hypertensive rats and dogs

The antihypertensive action of lercanidipine (CAS 132866-11-6, Rec 15/2375), a new 1,4-dihydropyridine (1,4-DHP) calcium entry blocker (CEB), was examined in spontaneously hypertensive rats (SHR) and renal hypertensive dogs after acute and repeated administration, in comparison to several reference 1,4-DHPs. In acute experiments in SHR, lercanidipine reduced diastolic blood pressure showing a potency similar to felodipine and 2-3 fold higher than those of nicardipine and nitrendipine, after both intravenous and oral administration. Analysis of the area under the curves of percent reduction of diastolic blood pressure exerted for 3 and 8 h after intravenous and oral administrations, respectively, showed that the duration of the antihypertensive effect of lercanidipine was longer than that of the reference dihydropyridines. After repeated administrations to SHR no tachyphylaxis was observed, as indicated by the marked and persistent decrease in systolic blood pressure elicited by lercanidipine, given orally once a day for 21 days. Moreover, starting from the first week of treatment, the daily basal values of systolic blood pressure of the rats treated with lercanidipine were significantly lower than those of the placebo-treated group. In renal hypertensive dogs, after acute oral administration, lercanidipine was as potent as nitrendipine. After repeated administration, the action of lercanidipine was longer lasting than that of nicardipine and no decrease in the antihypertensive effects was observed. The in vivo studies show that lercanidipine has a potent and long-lasting antihypertensive profile, suggesting that this compound may be used for once-a-day treatment.

Transamination of methionine after loading in patients with cirrhosis

BACKGROUND/AIMS

An impaired methionine degradation along the transsulfuration pathway has been widely described in cirrhosis. Evidence has been provided that methionine can also be degraded via a transamination pathway, leading to formation of methanethiol and its metabolites, protein-S-SCH3 (a mixed disulphide of blood proteins and methanethiol), alpha-ketomethylthiobutyrate and X-S-SCH3 (a mixed disulphide of a thiol with an unknown component X and methanethiol). This pathway seems to be of little importance in normal subjects, even after methionine loading, but its role in the presence of an acquired transsulfuration defect has never been tested.

METHODS

We measured the plasma concentration of methanethiol metabolites in six normal subjects and 11 patients with cirrhosis receiving a primed-continuous infusion of L-methionine, at rates able to increase plasma methionine to levels approximately 20 times basal concentrations.

RESULTS

Before methionine infusion, the sum of transamination metabolites was similar in the two groups (0.29 +/- SD 0.07 mumol/l in controls and 0.45 +/- SD 0.22 in patients with cirrhosis). During methionine infusion and after the end of infusion, there was a progressive increase of transamination metabolites, which reached values approximately 10 times basal concentrations, with no difference between groups.

CONCLUSIONS

We conclude that transamination cannot represent a quantitatively important exit for excess methionine in subjects with cirrhosis, in the presence of an acquired block along the transsulfuration pathway.

Effect of propionyl-L-carnitine on the mechanics of right and left papillary muscles from volume-overloaded rat hearts

Propionyl-L-carnitine (PLC) was shown to improve global cardiac function in pressure overload hypertrophy by acting directly on muscle mechanics. We investigated whether PLC can effectively ameliorate papillary muscle mechanics in a volume overload (VO) model. We induced VO by constructing an aortocaval anastomosis in adult Wistar rats. Three experimental groups were studied: sham-operated controls and untreated and PLC-treated VO animals. Isometric function of right and left papillary muscle was studied 16-18 weeks later. PLC was administered in the drinking water at the dose of 180 mg/kg for the last 2 weeks before experiment. One-way analysis of variance (ANOVA) showed that in right papillary muscles from the untreated VO group the time course of the isometric contraction was significantly prolonged [time-to-peak tension (TPT, ms +/- SEM) from 126 +/- 4.9 to 156 +/- 7.1; time from peak tension to 30% relaxation (TRel) from 133 +/- 11.9 to 196 +/- 13.9; n = 11 and 8, respectively], and peak rates of contraction and relaxation normalized over developed tension were significantly decreased in comparison with sham [from (s-1 +/- SEM) 12.9 +/- 0.5 to 10.8 +/- 0.6, and from 7.2 +/- 0.6 to 5.2 +/- 0.4, respectively]. These parameters in the PLC VO group did not differ from sham (TPT, 140 +/- 5.7; TRel, 158 +/- 14.4; +dF/df/DT, 12.2 +/- 0.6; -dF/df/DT, 6.5 +/- 0.5; n = 8). Function of left papillary muscle was not modified by either VO or PLC treatment. Total carnitine levels in either ventricle free walls were unchanged by VO. PLC significantly increased total carnitine content of left ventricle free wall (from 5.4 +/- 0.28 to 7.0 +/- 0.50). The contraction changes observed in the right papillary muscle are likely to depend on the pressure overload occurring in the right chamber; moreover, they are unrelated to tissue carnitine depletion. PLC improved the altered right papillary muscle mechanics without exerting any apparent effect on the functionally normal left papillary muscle. PLC activity is independent of carnitine stores, but may presumably be ascribed to its anaplerotic properties.