[The general practitioner facing hepatitis C]

Infection due to hepatitis C virus is currently a major public health problem, worldwide but also in Belgium. Indeed, 200 million people (3% of the world population, 1% of the Belgian population) are infected with, in more than 80% of the cases, an evolution toward chronic infection with the potential development of severe liver disease (chronic hepatitis with fibrosis, cirrhosis, hepatocarcinoma). The general practitioner has a central position in the management of hepatitis C. His role is to prevent the infection, giving advice on the risk factors, to screen high risk groups, to monitor infected patients and to discuss with him the indications and contra-indications for antiviral therapy and to follow the treated patient in close collaboration wit the hepatogastroenterologist to ensure adherence, to manage the side effects and to monitor the non treated patient as well as the non responder.

Daily induction combination treatment with alpha 2b interferon and ribavirin or standard combination treatment in naive chronic hepatitis C patients. A multicentre randomized controlled trial

The standard treatment for patients with chronic hepatitis C is a 6-12-month combination therapy with interferon alpha and ribavirin. Induction treatment could result in a faster early decline of the hepatitis C virus (HCV) load and a better response rate. Naive chronically infected HCV patients (n = 454) were randomized into two arms to receive either induction treatment with interferon alpha 2b 5 million units (MU) subcutaneously (s.c.) daily during a period of 8 weeks (arm A); or treatment with interferon alpha 2b 5 MU s.c. three times a week (TIW) for a period of 8 weeks (arm B). After week 8, interferon treatment in both arms was 3 MU s.c. TIW for a total period of 12 months. In both arms, ribavirin (1000-1200 mg orally per day) was added at week 4. Induction treatment resulted in a higher virological response at week 8 of treatment (66%vs 47%; P < 0.01). However, response at the end of treatment and at 6 months follow-up was not different (53%vs 50%, 41%vs 33%). The occurrence of adverse events and the drop-out rate were similar in both arms. Although an early virological response is observed more frequently in the induction treatment, end of treatment response and sustained responses did not differ.

[The medical gastroenterology department]

The present paper summarizes the various themes of research which have been developed in the department of medical gastroenterology since it was created in 1977. These include: in pancreatology, the study of chronic pancreatitis pathogenesis, acute pancreatitis pathogenesis and immunomodulation, endoscopic treatment of chronic pancreatitis, the development of new imaging techniques of the bile ducts and the pancreas, as well as the treatment of pancreatic cancer and benign or malignant biliary diseases. in hepatology, the immunomodulation of liver cirrhosis, especially alcoholic liver disease, the modulation of experimental acute and chronic hepatitis, the study of liver ischemia-reperfusion. Clinical hepatology has focused on liver transplantation, prognosis factors of chronic liver disease and treatment of portal hypertension and viral hepatitis. in gut diseases, the treatment of gastro-oesophageal reflux and its complications, the therapeutic endoscopy of the upper and lower GI and the prevention, as well as the treatment, of colon cancer, the pathogenesis and the immunopharmacology of inflammatory bowel diseases and the clinical enteral and parenteral nutrition.

Naloxone-precipitated withdrawal jumping in 11 inbred mouse strains: evidence for common genetic mechanisms in acute and chronic morphine physical dependence

Physical dependence is a widely known consequence of morphine intake. Although commonly associated with prolonged or repeated morphine administration, withdrawal symptoms can be elicited even after a single prior morphine exposure. What remains contentious is the extent to which physical dependence following acute and chronic morphine treatment is mediated by common physiological substrates and, accordingly, represent distinct syndromes. The genetic relationship between acute and chronic morphine dependence was thus presently studied by comparing mice of 11 inbred strains (129P3, A, AKR, BALB/c, C3H/He, C57BL/6, CBA, DBA/2, LP, SJL, and SWR) for naloxone-precipitated withdrawal jumping responses using three subcutaneous morphine administration paradigms: acute (single injection) or chronic (three daily morphine injections for 4 days) injection, or chronic infusion (7 days via implanted osmotic minipumps). Although there were differences in the magnitude of withdrawal jumping between the three different morphine administration paradigms, large and significant strain differences were observed for each. In addition, the same strains were unusually sensitive or, conversely, altogether refractory to withdrawal jumping across all morphine treatment conditions. Overall, strain jumping means between acute and chronic dependence paradigms displayed a high degree of genetic correlation (r=0.87-0.95). The significant correlation between chronic morphine injection and continuous morphine infusion discounts the possible confounding effect of contextual learning and spontaneous withdrawal between chronic injections on the assessment of naloxone-precipitated withdrawal. Substantial heritability was also observed for acute and both paradigms of chronic dependence, with estimates ranging from h(2)=0.53 to 0.70. The present demonstration of a strong genetic correlation between physical dependence to morphine following acute and chronic treatment implies that genes associated with variable sensitivity in the two traits are the same, and is suggestive of shared physiological substrates. The data also demonstrate that the differential genetic liability to morphine physical dependence begins with, and is predicted by, the first morphine exposure.

Hepatitis C virus: the burden of the disease

Chronic hepatitis C infection affects approximately 3% of the world population and is responsible for a large proportion of patients with cirrhosis, end-stage liver diseases, hepatocellular carcinoma and for those who are candidates for liver transplantation or die of liver-related complications. The health care burden of this infection, whose epidemic peaked in the 1980s, is expected to significantly increase in the next 15 years in the absence of an organized national strategy. On the other hand, hepatitis C infection can be easily diagnosed with third generation enzyme immunoassay and indications for molecular biology-based assay are well defined. Composite scores and non-invasive markers of fibrosis may in the future replace liver biopsy which is still recommended in the presence of chronically elevated transaminases and indications for antiviral treatment.

A comparison of self-concept and personality disorders in women with pain accounted for by psychological factors, women with major depression, and healthy controls

OBJECTIVE

Do patients with pain accounted for by psychological factors (P) differ in their self-concept and personality disorders from patients with major depression (D) and healthy controls (C)?

METHOD

Thirty hospitalized P-patients (DSM-IV, 307.80) and 30 hospitalized D-Patients (DSM-III-R) were given the Beck Depression Inventory on admission (BDI-1) and at discharge (BDI-2). Together with BDI-2, patients filled out the Personality Disorder Questionnaire for DSM-III-R (PDQR) and the Frankfurt Self-Concept Scales (FSKN). Thirty-two healthy comparisons (C) completed the same questionnaires.

RESULTS

BDI-2 showed no significant differences between groups P and D, a prerequisite for the comparison of psychological traits. PDQR differed in the three groups. D showed more dependent, obsessive-compulsive, and histrionic personality features than group P. The three groups differed in FSKN total score and all 10 subscales (C (healthiest self-concept) > P > D). Groups P and D were different (P > D) in total score and subscales: performance, problem coping, confidence in behavior and decision taking, and self-esteem. Ten P-patients with pathological BDI-2 (P(D)) had significantly more disturbed PDQR and FSKN scores than the non-depressed (P(ND)), and closely resembled the D-patients.

CONCLUSIONS

Personality disorders and self-concept are not homogenous in female patients with P. Subgroup P(ND) differs from patients with depression (fewer personality disorders, better self-concept), whereas subgroup P(D) closely resembles them.

[Acute diarrhea in adults]

The cause of an acute diarrhea is often infectious and a lot of pathogens are implicated: bacteria, parasites and viruses. The clinical approach required several steps and induce different advices such as avoiding stool cultures in the absence of fecal leucocytes, supportive therapy with rehydration, diverse empirical and urgent antibiotherapies. The increasing incidence of antimicrobial resistance of enteropathogens argues against the overconsumption of antibiotics.

Nanostructured dna-protein aggregates consisting of covalent oligonucleotide-streptavidin conjugates

Covalent conjugates consisting of streptavidin and a 24-mer single-stranded DNA oligonucleotide have been oligomerized by cross-linking with a 5',5'-bis-biotinylated 169-base-pair double-stranded DNA (dsDNA) fragment. The oligomeric conjugates formed have been analyzed by nondenaturing gel electrophoresis and scanning-force microscopy (SFM). The comparison of analogous oligomers, prepared from native STV and the bis-biotinylated dsDNA fragment, revealed that the covalent STV-oligonucleotide hybrid conjugates self-assemble to generate oligomeric aggregates of significant smaller size, containing on average only about 2.5 times less dsDNA fragments per aggregate. Likely, this is a consequence of electrostatic or steric repulsion between the dsDNA and the single-stranded oligomer covalently attached to the hybrid, as indicated from control experiments. Nevertheless, the single-stranded oligonucleotide moiety within the oligomeric conjugates can be used as a selective molecular handle for further functionalization and manipulation. For instance, it was used for specific DNA-directed immobilization at a surface, previously functionalized with complementary capture oligonucleotides. Moreover, we demonstrate that macromolecules, such as STV and antibody molecules, which are tagged with the complementary oligonucleotide, specifically bind to the supramolecular DNA-STV oligomeric conjugates. This leads to a novel class of functional DNA-protein conjugates, suitable, for instance, as reagents in immuno-PCR or as building blocks in molecular nanotechnology.

Neuromuscular transmission and muscle contractility in SNAP-25-deficient coloboma mice

Synaptosomal associated protein of 25 kDa (SNAP-25) is a cytoplasmic protein that participates in the docking and fusion of synaptic vesicles with the nerve terminal in preparation for neurotransmitter release. SNAP-25 is also a substrate for three of the seven serotypes of botulinum neurotoxin (BoNT). Intoxication by BoNT/A, /C1 or /E results in weakness and paralysis of skeletal muscle due to cleavage of SNAP-25 (and syntaxin la in the case /C1) at discrete serotype-specific sites. To elucidate the role of SNAP-25 in muscle function in more detail, contractility and neuromuscular transmission were studied in a mutant mouse model termed coloboma. The coloboma mutation results from a contiguous deletion of 1-2 centiMorgans on chromosome 2, which includes the entire SNAP-25 locus and three other identified genes. Homozygotes do not survive beyond gestation day 6; heterozygotes (Cm/+) have a normal life-span but express reduced levels of SNAP-25 mRNA and protein in the brain. The consequences of the Cm/+ mutation on twitch and tetanic tension, quantal release of neurotransmitter and spinal motoneuron expression of SNAP-25 were examined in the present study. Contrary to expectations, Cm/+ mice exhibited no alteration in twitch tension and generated normal tetanic tension even at the highest frequency examined (800 Hz). Microelectrode recordings revealed that MEPP amplitude and frequency were both within control limits. The ventral spinal cord of Cm/+ mice showed no deficiency in SNAP-25 content and immunohistochemical examination of nerve terminals in Cm/+ mice disclosed that SNAP-25 levels and distribution were similar to those of control mice. It is concluded that spinal motor neurons up-regulate SNAP-25 to preserve vital neuromuscular function.

[Screening for colorectal cancer by endoscopy: rectosigmoidoscopy or coloscopy?]

Screening for colorectal cancer is almost uniformly recommended for average-risk asymptomatic persons aged 50 years and older and it may substantially reduce its relative mortality. However, consensus is lacking about the type of screening test. Flexible sigmoidoscopy followed by colonoscopy in the presence of adenoma(s), detect 70% of the neoplasms and should be recommended for adults aged 50 years and older. Colonoscopy with polypectomy may ultimately become the preferred strategy after 60 years and certainly in the presence of alarm signs and personal or familial risks for colorectal cancer.

Nodular regenerative hyperplasia of the liver. A review of 14 cases

BACKGROUND/AIMS

Nodular regenerative hyperplasia of the liver, is a noncirrhotic liver disease, characterized by nodules in the hepatic parenchyma, which clinically presents primarily with manifestations of portal hypertension. The aims of this study are i) to review the clinical, histological and diagnostic aspects of 14 documented cases of NRHL, and ii) to assess the evolution and management of this condition in the cases reviewed.

METHODOLOGY

The diagnosis of nodular regenerative hyperplasia of the liver was based on liver biopsy in all cases. Imaging studies (ultrasonography, computed tomography scan and magnetic resonance imaging scan) were performed as part of the diagnostic evaluation. Clinical manifestations and biochemical tests were recorded at the time of diagnosis. Management and prognosis were also reviewed.

RESULTS

The most common clinical manifestations were those of portal hypertension, namely splenomegaly, esophageal varices and variceal bleeding. The histological findings were nodules in the hepatic parenchyma, the typical histologic feature of nodular regenerative hyperplasia of the liver, with mild periportal fibrosis and intraportal lymphocytic infiltration. Biochemical tests showed normal synthetic liver function, as evidenced by normal serum albumin, bilirubin and prothrombin time. Elevation of gamma-glutamyl transpeptidase and alkaline phosphatase due to cholestasis was noted. Management was directed to portal hypertension and variceal bleeding, with beta-blockers, sclerotherapy, mesenteric-caval shunt and transjugular intrahepatic portosystemic shunt with satisfactory results.

CONCLUSIONS

Nodular regenerative hyperplasia of the liver is an uncommon condition but it should be considered in patients with unexplained portal hypertension and distinguished from liver cirrhosis, in view of the differences in the natural history and prognosis. Liver biopsy confirms the diagnosis. Management is directed primarily to portal hypertension and variceal bleeding, which is the main source of mortality. Liver failure is uncommon due to satisfactory preservation of liver function.

[Individual screening for colorectal cancer: which strategy for which patient?]

Currently, more than 4,000 newly colorectal cancer are diagnosed each year in Belgium. The individual average-risk for developing colorectal cancer is about 5%. 90% of colorectal cancer occurred after the age of 50, and in 70% of the cases in patients without particular risk factors (average-risk population). Personal and/or familial history of colorectal adenoma, colorectal cancer, inflammatory bowel disease localised to the colon, familial polyposis syndrome or Hereditary Non Polyposis Colorectal Cancer (HNPCC) increase the risk of colorectal cancer. An individual appropriate screening of high-risk patients and average-risk asymptomatic patients older than 50, together with endoscopic resection of adenoma decrease the incidence and the mortality of colorectal cancer. Usual screening methods are fecal occult blood testing which is not proven to be efficient alone for individual screening (but still recommended for general population's screening), sigmoidoscopy (which has to be completed by a colonoscopy, if lesions founded), and colonoscopy. Virtual colonoscopy and genetic testing need further evaluation. Currently, colonoscopy seems to be the goldstandard method providing complete examination of the whole colon and being the most cost-effective method. Screening strategy should be decided on an individual basis considering the patient's benefit with respect to the informed consent.

Assessment of acute and chronic morphine dependence in male and female mice

The present study compared male and female mice for frequency of naloxone-precipitated jumping and naloxone ED(50) values, two common indices of physical dependence, following acute and chronic morphine administration. Both sexes displayed a positive dose-response relationship between acute morphine and naloxone doses and jumping frequency. There was a significant main effect of sex, with mean jumping frequencies greater in males. The naloxone ED(50) estimate was also fourfold lower in males, indicating greater withdrawal sensitivity than females. Jumping frequencies were similar in male and female saline-treated control mice, discounting initial sex differences as a significant factor in the unequal magnitude and sensitivity in acute morphine dependence between sexes. In contrast, males and females displayed similar mean withdrawal jumping frequencies and naloxone ED(50) values after 3 days of morphine injections. Sex difference in withdrawal jumping was also not observed when morphine treatment was increased to 7 days via daily injection or continuous subcutaneous infusion. The present study demonstrates the development of greater physical dependence in male relative to female mice following acute but not chronic morphine administration.

[Therapeutic approach to chronic hepatitis B and C in the dawn of the third millenium]

We try to illustrate the latest developments in epidemiology, pathogenesis and natural history of hepatitis B and C virus infection. Practical management of the patient with chronic B and C liver disease is presented. Universal hepatitis B vaccination should be encouraged in order to reduce to zero morbidity and mortality attributable to liver disease and its complications. Patients at risk for hepatitis B or C infection should be screened and notified about their evolutive risk and the therapeutic possibilities.

Domino hepatic transplantation using the liver from a patient with primary hyperoxaluria

BACKGROUND

We report a case of domino liver transplantation using the liver harvested from a patient who underwent a combined liver and kidney transplantation for primary hyperoxaluria (PH).

METHOD

A cadaveric liver transplantation was performed in a 19-year-old man with PH. In a second step, the PH liver harvested from the first patient was transplanted in a 69-year-old man with hepatitis C-related cirrhosis, not a candidate for a classic liver graft owing to multifocal hepatocellular carcinoma.

RESULTS

At 8 months after transplantation, the domino recipient has normal hepatic function and no signs of tumoral recurrence, but he progressively developed hyperoxalemia, hyperoxaluria, and renal insufficiency.

CONCLUSION

Regarding the favorable postoperative clinical evolution, domino liver transplantations using livers from PH patients may represent a new opportunity for marginal candidates for liver transplantation. However, the progressive renal insufficiency expected in such domino recipients should limit this procedure to selected cases.

Nucleic acid supercoiling as a means for ionic switching of DNA--nanoparticle networks

Oligomeric nanoparticle networks, generated by the self-assembly of bis-biotinylated double-stranded DNA fragments and streptavidin, have been studied by scanning force microscopy (SFM). SFM imaging revealed the presence within the networks of irregular thick DNA molecules, which were often associated with distinct, Y-shaped structural elements. Closer analysis revealed that the Y structures are formed by condensation (thickening and shortening) of two DNA fragments, most likely through the supercoiling of two DNA molecules bound to adjacent binding sites of the streptavidin particle. The frequency of supercoiling was found to be dependent on the ionic strength applied during the immobilization of the oligomeric networks on mica surfaces. Potential applications of the structural changes as a means for constructing ion-dependent molecular switches in nanomaterials are discussed.