Limited gene dispersal and spatial genetic structure as stabilizing factors in an ant-plant mutualism.

Comparative studies of the population genetics of closely associated species are necessary to properly understand the evolution of these relationships because gene flow between populations affects the partners' evolutionary potential at the local scale. As a consequence (at least for antagonistic interactions), asymmetries in the strength of the genetic structures of the partner populations can result in one partner having a co-evolutionary advantage. Here, we assess the population genetic structure of partners engaged in a species-specific and obligatory mutualism: the Neotropical ant-plant, Hirtella physophora, and its ant associate, Allomerus decemarticulatus. Although the ant cannot complete its life cycle elsewhere than on H. physophora and the plant cannot live for long without the protection provided by A. decemarticulatus, these species also have antagonistic interactions: the ants have been shown to benefit from castrating their host plant and the plant is able to retaliate against too virulent ant colonies. We found similar short dispersal distances for both partners, resulting in the local transmission of the association and, thus, inbred populations in which too virulent castrating ants face the risk of local extinction due to the absence of H. physophora offspring. On the other hand, we show that the plant populations probably experienced greater gene flow than did the ant populations, thus enhancing the evolutionary potential of the plants. We conclude that such levels of spatial structure in the partners' populations can increase the stability of the mutualistic relationship. Indeed, the local transmission of the association enables partial alignments of the partners' interests, and population connectivity allows the plant retaliation mechanisms to be locally adapted to the castration behaviour of their symbionts.

Effect of antiviral therapy on circulating cytokeratin-18 fragments in patients with chronic hepatitis C.

Hepatocellular apoptosis plays a major role in the pathogenesis of chronic hepatitis C. It can be measured noninvasively by determining the circulating levels of cytokeratin-18 fragments. We hypothesized that the effect of antiviral therapy on this parameter will be different in patients with a sustained virological response, relapse (REL) and nonresponse (NR). We quantified cytokeratin-18 fragments in plasma of patients participating in the Swiss Hepatitis C cohort, who received antiviral therapy without stopping because of sides effects. A total of 315 patients were included, 183 with a sustained response, 64 with NR and 68 who relapsed. Mean levels ±SD of circulating cytokeratin-18 fragments before therapy were 174 ± 172 U/L for responsders, 188 ± 145 for nonresponders and 269 ± 158 U/L for patients who relapsed. The values were significantly higher in the REL group (ANOVA P < 0.006). A sustained response was associated with a significant improvement of the plasma levels (94 ± 92 U/L, paired test P < 0.000001), whereas there was no improvement in the nonresponder group (183 ± 158 U/L) and in the relapser group (158 ± 148 U/L). There was a weak correlation between alanine aminotransferase (ALT) and cytokeratin-18 fragment levels (r² = 0.35, P < 0.000001) before therapy but not after therapy and none with hepatitis C virus (HCV) viremia. Successful antiviral therapy results in a significant decrease in circulating levels of cytokeratin-18 fragments arguing for a reduction in hepatocellular apoptosis after clearance of the HCV. Baseline cytokeratin-18 fragment levels are higher in relapsers. Correlations with ALT are weak, suggesting that these two tests measure different but related processes.

Sirolimus-induced inflammatory papules with acquired reactive perforating collagenosis.

Sirolimus is an immunosuppressive macrolide with antineoplasic properties that is increasingly used in posttransplantation immunosuppression. The treatment is frequently associated with cutaneous side effects such as sirolimus-associated acneiform facial dermatitis, which has been observed in up to 50% of treated patients. We report a 51-year-old female with liver transplantation who developed inflammatory papules and nodules on the face and the upper chest 3 weeks after the initiation of sirolimus therapy. Sequential biopsies revealed lymphocytic infiltration of the dermis with a peculiar pattern of sebotropism, while older lesions showed acquired reactive perforating collagenosis. The lesions were responsive to hydroxychloroquine treatment despite continued sirolimus treatment.

Steatosis affects chronic hepatitis C progression in a genotype specific way.

BACKGROUND AND AIMS: Liver steatosis is frequent in chronic hepatitis C, particularly in patients infected with hepatitis C virus (HCV) genotype 3. The aim of this study was to determine the relationship between steatosis and fibrosis in chronic hepatitis C as a function of viral genotype. METHODS: A multivariable logistic regression analysis was carried out in 755 chronic hepatitis C patients (mean body mass index (BMI) 24.11 kg/m(2); 178 with genotype 3), consecutively admitted to three referral hospitals. Liver histology showed steatosis in 315 and fibrosis in 605 patients, of whom 187 had cirrhosis (78 compensated and 109 decompensated). RESULTS: Steatosis was independently associated with fibrosis (p<0.001), genotype 3 (p<0.001), BMI (p<0.001), ongoing alcohol abuse (p<0.001), and age (p = 0.001). Fibrosis was associated with the Metavir activity score (p<0.001), age (p<0.001), steatosis (p = 0.001), past alcohol abuse for >5 years (p = 0.015), and BMI (p = 0.034). When regression analysis was repeated on patients divided according to viral genotype (that is, 3 v non-3) to identify type specific risk factors, steatosis was associated with ongoing alcohol abuse (p<0.001) and age (p = 0.01) only in non-3 genotype infected patients and with Metavir activity (p = 0.044) only in genotype 3 infected patients. Similarly, fibrosis was associated with steatosis only in genotype 3 infected individuals (p = 0.018), and with past alcohol abuse (p = 0.003) and (marginally) diabetes (p = 0.078) only in non-3 genotype infected patients. CONCLUSIONS: Steatosis influences chronic hepatitis C progression in a genotype specific way. Patients infected with genotype 3 and histologically confirmed steatosis should not be deferred from effective antiviral therapy.

Liver steatosis in chronic hepatitis C: a morphological sign suggesting infection with HCV genotype 3.

AIMS: To identify factors associated with liver steatosis in chronic hepatitis C. METHODS AND RESULTS: Occurrence and severity of liver steatosis in 254 chronic hepatitis C patients were compared with presence of alcohol abuse, body mass index (BMI) >26, history of intravenous drug addiction and hepatitis C virus (HCV) genotype. Steatosis was found in 109 (43%) patients. The occurrence of steatosis was significantly associated with ongoing alcohol abuse (P=0.03) or HCV genotype 3 (P= 0.003), but not with BMI >26. A moderate to severe steatosis was present in 60% of patients infected with HCV genotype 3, irrespective of the presence of alcohol abuse, BMI >26 or history of intravenous drug addiction. Using a multivariable stepwise logistic regression analysis, infection with genotype 3 had an odds ratio (OR) of 10 (95% confidence interval (CI)=4.56-22) for a liver steatosis, whereas the presence of a cirrhosis at histology had an OR=0.256 (95% CI=0.07-0.92). CONCLUSIONS: A moderate to severe degree of steatosis of the liver is a morphological sign suggestive of infection with HCV genotype 3, independent of other risk factors of a fatty liver, but it may disappear at late stages of the disease.

Hepatocyte steatosis is a cytopathic effect of hepatitis C virus genotype 3.

BACKGROUND/AIMS: Patients infected with the hepatitis C virus (HCV) often have liver steatosis, suggesting the possibility of a viral cytopathic effect. The aim of this study was to correlate the occurrence and severity of liver steatosis with HCV RNA type, level and sequence of the core-encoding region. METHODS: We scored the liver steatosis in 101 HCV-infected individuals carefully selected to exclude other risk factors of a fatty liver. Results were compared with HCV RNA genotype and level in serum and liver. In selected patients, we assessed the effect of antiviral therapy on steatosis and the relationship between nucleocapsid sequence heterogeneity and fat infiltration. RESULTS: Steatosis was found in 41 (40.6%) patients, irrespective of sex, age or route of infection. HCV genotype 3 was associated with higher steatosis scores than other genotypes. A significant correlation between steatosis score and titer of intrahepatic HCV RNA was found in patients infected with genotype 3, but not in those infected with genotype 1. In selected patients, response to alpha-interferon was associated with the disappearance of steatosis. Analysis of the nucleocapsid of 14 HCV isolates failed to identify a sequence specifically associated with the development of steatosis. CONCLUSIONS: We provide virological and clinical evidence that the steatosis of the liver is the morphological expression of a viral cytopathic effect in patients infected with HCV genotype 3. At variance with published evidence from experimental models, the HCV nucleocapsid protein does not seem to fully explain the lipid accumulation in these patients.

Hemochromatosis gene mutations in chronic hepatitis C patients with and without liver siderosis.

Chronic hepatitis C is often associated with liver iron overload, which may affect the long-term prognosis and the response to antiviral treatment. The occurrence of hemochromatosis (HFE) mutations were studied to determine whether may contribute to the liver iron overload of chronic hepatitis C patients. The prevalence of two HFE mutations (C282Y and H63D) in 120 chronic hepatitis C patients was determined and the findings were correlated with clinical, histological and virological features. Hepatic iron was determined semiquantitatively by a histochemical hepatic iron index, defined as the ratio of a histochemical staining score to the patient's age, after correction for heterogeneous lobular iron distribution. Serum hepatitis C virus (HCV) RNA was measured by bDNA assay and typed by restriction fragment length polymorphism. Liver HCV RNA was measured by a semi-quantitative strand-specific reverse transcription-polymerase chain reaction (RT-PCR). Excess liver iron was stained in the liver of 36 patients (30%). Siderotic patients had the same geographic origin, serum and liver HCV RNA levels and H63D and C282Y mutations frequency as non-siderotic patients. However, siderotic patients were older (P = 0.015), more frequently males (P = 0.02), less frequently infected with HCV genotype 3 (P = 0.037) and had a higher liver fibrosis score (P = 0.008). The liver iron content did not correlate with the serum or liver HCV RNA titers. Ten of the 36 patients with liver siderosis had neither a history of excess alcohol intake, multiple transfusions, or HFE mutations. In conclusion, the pathogenesis of the liver iron overload in chronic hepatitis C patients cannot be fully explained by the occurrence of HFE mutations. The exact mechanism of iron accumulation in these patients therefore remains unexplained.

Treatment of chronic hepatitis C with alpha-interferon plus ofloxacin in patients not responding to alpha-interferon alone.

BACKGROUND/AIMS: Ofloxacin, a quinolone antibiotic, was recently shown to increase the primary response rate to alpha-interferon treatment of chronic hepatitis C. METHODS: Fifty-five patients with chronic hepatitis C were scheduled to receive 3 MU of a-interferon, three times a week, for 1 year. After 3 months of therapy, patients who were still HCV RNA-positive in serum started receiving a combined regimen with 3 MU of alpha-interferon, three times a week, plus ofloxacin, 600 mg daily, per os. After 3 months of combined therapy, patients with undetectable serum HCV RNA continued the combined regimen for another 6 months, whereas patients who were still HCV RNA-positive were definitively considered as non-responders and withdrawn from the study. Serum HCV RNA levels were quantitatively evaluated after 3 months of therapy with a-interferon alone and compared with those detected after 3 months of combined regimen. RESULTS: Among the 54 patients who completed the first 3 months of treatment, 32 (59.3%) still had HCV RNA detectable in serum and started receiving the ofloxacin/alpha-interferon therapy. Among the 26 patients who completed the 3 additional months of combined regimen, only one showed a virological response: this patient maintained a complete response to the end of combined treatment, but relapsed thereafter. The combination therapy had no effect on the serum HCV RNA or alanine aminotransferase levels. CONCLUSIONS: The combined administration of alpha-interferon and ofloxacin to patients with chronic hepatitis C who have not responded to alpha-interferon alone does not increase the primary virological response rate.

Fixed versus titrated interferon-alpha 2B in chronic hepatitis C. A randomized controlled multicenter trial. The Swiss Association for the Study of the Liver.

BACKGROUND/AIM: Interferon has become the mainstay of treatment of chronic hepatitis C; however, duration of treatment and dose remain unresolved questions. The present study aimed to compare standard dose interferon with a titrated dose regimen carried out for 1 year. METHODS: This was a randomized, controlled multicenter trial. Patients with chronic hepatitis C were randomly allocated to a control group (n = 30), to a fixed dose group (n = 31) where interferon-alpha 2b 3 MU thrice weekly was given for 1 year or a titrated group (n = 34) where interferon was titrated starting at 5 MU thrice weekly to the lowest dose keeping the patient in remission as assessed by a normal ALT value. Liver biopsies were obtained before and at the end of treatment; in addition, galactose elimination capacity was measured as a measure of cytosolic function. RESULTS: In the control, fixed and titrated groups a complete response was achieved in 2/29, 10/28 and 15/31, respectively (p < 0.001 in favor of treatment, p = n.s. for the two treatments). The corresponding figure for sustained response was 1/29, 5/28 and 6/ 31 (p = n.s). In the titrated group, a complete (sustained) response was achieved with 5 MU in 2 (2), with 4 MU in 1 (0), with 3 MU in 4 (0), with 2 MU in 3 (0) and with 1 MU in 5 (4). Liver biopsy score and galactose elimination capacity improved significantly in responders but not in treatment failures. CONCLUSIONS: Both fixed and titrated dosing of interferon given for 1 year induced virus clearance in only a minority of treated patients. However, in a small number of patients, a complete and sustained response can be achieved with low doses of interferon. Dose titration could be an interesting approach to decreasing the cost and side effects in the treatment of chronic hepatitis C.

Efficacy of steroid withdrawal and low-dose interferon treatment in chronic active hepatitis B. Results of a randomized multicenter trial. Swiss Association for the Study of the Liver.

Fifty-six patients with biopsy-proven, chronic active hepatitis B were included in a multi-center, randomized trial comparing steroid withdrawal followed by 1.5 MU recombinant interferon alpha 2b (Intron) with placebo withdrawal followed by either 1.5 or 5 MU interferon. The patients were equally distributed between the treatment groups with respect to biochemical and histologic activity as well as with respect to DNA levels and quantitative liver function tests. One patient was lost to follow up. After 1 year of treatment, 10/18, 13/19 and 11/18 patients had lost hepatitis B virus DNA in the three groups, respectively (non-significant). Transaminase levels were normal in 27/34 of the responders but in only 4/21 of the non-responders (p < 0.0001). Both galactose elimination capacity and aminopyrine breath test improved significantly in responders, but either did not change (aminopyrine breath test) or deteriorated in non-responders (galactose elimination capacity). Biopsy score improved in both groups but this reached statistical significance only in responders. This effect was due to improvements in both inflammatory and fibrotic activity. Side effects included almost universally a flu-like syndrome, granulocytopenia (1), depression (3) and thyroid dysfunction (2). Two deaths occurred, one due to hepatocellular cancer, and the other to hepatorenal syndrome after spontaneous bacterial peritonitis. A severe cytolytic episode was observed in three patients in the steroid withdrawal group. We conclude that in patients with marked histologic activity, lower doses of interferon may be as effective as the standard dose of 5 MU.(ABSTRACT TRUNCATED AT 250 WORDS)

Low-dose interferon in chronic hepatitis non-A/non-B: effects on quantitative liver function and structure in a randomized, controlled multicenter trial.

In this randomized, controlled multicenter trial we evaluated the effects of recombinant interferon-alpha 2b on galactose elimination capacity and histological activity index in 88 patients with chronic active hepatitis non-A/non-B. Forty-five patients were randomly assigned to treatment with interferon at 1.5 x 10(6) U three times per for 1 year; 43 patients were assigned to no treatment. A complete response (normalization of alanine aminotransferase) was observed, respectively, in 47% and 5% of the two groups (P < 0.006); 47% of these patients suffered a relapse. Thus 22% of patients had a sustained response. Histological activity decreased significantly in responders (P < 0.04) while the biopsy score did not change significantly in nonresponders. In contrast, galactose elimination capacity--a surrogate marker for survival in chronic active hepatitis--was not affected by response to treatment. None of the parameters evaluated, including hepatitis C virus RNA, was able to predict response or relapse. We conclude that low-dose interferon treatment for 1 year is as effective as the recommended treatment schedule.

The disposition and metabolism of (+)-cyanidanol-3 in patients with alcoholic cirrhosis.

The effect of alcoholic cirrhosis of the liver on the disposition and metabolism of (+)-cyanidanol-3 has been studied in three patients. Following oral intake of U-14C-(+)-cyanidanol-3 2 g, the unchanged drug was detected in plasma between 0.5 and 24 h after dosing and the metabolites, measured only as 14C-levels, were still detectable at 120 h. A mean of 55% of the dose was excreted in the urine, in which the major metabolites were the glucuronic and sulphuric acid conjugates of (+)-cyanidanol-3 and 3'-O-methyl-(+)-cyanidanol-3, although one patient excreted a larger proportion as non-conjugated metabolites. The pattern of metabolism in the patients did not differ significantly from that in control subjects, suggesting that the drug is handled by the cirrhotic liver in a similar manner to the normal liver.

[Choice and modalities of the treatment of biliary lithiasis]. / Choix et modalités de traitement de la lithiase biliaire.

Western life-style and an older population make gallstones, "silent" or otherwise, a commoner problem than in the past. Whilst symptomatic gallstones should be treated surgically, "silent" gallstones usually remain that way and do not require prophylactic cholecystectomy. However, if common bile duct stones have been demonstrated or only suspected, surgery is the treatment of choice even in the absence of symptoms. Surgical mortality is very low at less than 1% for cholecystectomy and bile duct exploration. These figures apply to a population of whom half are over 70 years of age. Chemical dissolution of cholesterol gallstones is only of use in a small minority of patients, notably those at high surgical risk or who refuse surgery. Endoscopic sphincterotomy is useful as primary treatment in cases of cholangitis and gallstone-associated pancreatitis, and often allows removal of bile duct stones in inoperable patients.

Effects of single daily doses of a pyridil-2-tetrahydrothiophene derivative (40749 RP) on 24 hour H+ activity, nocturnal acid output, gastrin and pepsinogen I profiles in duodenal ulcer patients.

40749 RP is a pyridil-2-tetrahydrothiophene derivative, belonging to a new class of gastric antisecretory drugs. We compared its effects on gastric secretion with cimetidine. Intragastric acidity, nocturnal acid output, gastrin and pepsinogen-I profiles were measured in patients with duodenal ulcer in clinical remission. A single dose of 100 mg 40749 RP reduced median 24 h gastric acidity as effectively as cimetidine 1000 mg given as four divided doses, 0.63 vs 1.6 mmol/l. Continued treatment with 40749 RP for 10 days reduced the median 24 h gastric acidity even further, to 0.006 mmol/l (p less than 0.001) and significantly increased fasting concentrations of gastrin and pepsinogen-I (p = 0.02). The incremental gastrin secretion to a standard meal was significantly increased after 10 days treatment with 40749 RP when compared with the first day of 40749 RP, or with cimetidine. These results show that 40749 RP exerts a powerful inhibitory effect on gastric acid secretion after a single 100 mg dose, and that this inhibitory effect increases with continued administration.